Work vehicle

Abstract

Properly perform automatic driving. [Solution] The system comprises a positioning unit 86 that measures at least the position and orientation of the traveling vehicle body, and a direction control unit 60M that controls the traveling direction of the traveling vehicle body, and the direction control unit 60M is capable of performing automatic direction change control that changes the direction of the traveling vehicle body from a target straight path to the next target straight path.

Description

[Technical field]

[0001] The present invention relates to a work vehicle. [Background technology]

[0002] In a riding rice transplanter, which is an example of a work vehicle, a teaching path generation means generates a teaching path and a target path parallel to the teaching path based on position information measured by a GPS device, and causes the traveling vehicle body to travel autonomously on the target path (see, for example, Patent Document 1). One example of a work vehicle, a riding rice transplanter, is equipped with an auto-up control means that automatically raises the paddy field work equipment in conjunction with steering the running body, and a backup control means that automatically raises the paddy field work equipment in conjunction with operating the shift lever to the reverse shift operating path (see, for example, Patent Document 2). One example of a work vehicle is a riding rice transplanter, which is equipped with a main shift lever that enables gear shifting in the main transmission and forward / reverse switching, and the outer lateral side of the forward shift path in the left-right forward / reverse switching path provided in a guide groove that guides the main shift lever is set as the engine stop position.The guide plate is also equipped with a switch that detects operation of the main shift lever to the engine stop position, and the engine is stopped when it is detected that the main shift lever has been held in the engine stop position for a predetermined period of time based on the output of the switch (see, for example, Patent Document 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-131880 A [Patent Document 2] JP 2012-85646 A [Patent Document 3] JP 2006-94753 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the configuration described in Patent Document 1, the riding rice transplanter can be made to travel autonomously on a target route. However, when the riding rice transplanter reaches a direction change area (headland), the travel of the machine body is stopped automatically or by the operation of the driver (operator). Then, the driver raises the ground work device (planting unit) and operates the autonomous travel switch, so that the riding rice transplanter automatically turns in the desired direction, and after completing the automatic turn, the riding rice transplanter travels autonomously on the next target route. Then, when the planting start position is reached, the travel of the machine body is stopped automatically or by the operation of the driver. Then, the driver operates the ground work device to lower, so that the riding rice transplanter continues to travel autonomously on the target route.

[0005] In the configuration described in Patent Document 2, when the riding rice transplanter completes one work run and the machine is steered significantly to change direction in the direction change area (ridge), the auto-up control is activated, the ground work device (paddy field work device) automatically rises, and power transmission to the ground work device is cut off. Also, when the riding rice transplanter completes one work run and the machine is moved backward to change direction in the direction change area (switch turn), the backup control is activated, the ground work device automatically rises, and power transmission to the ground work device is cut off. However, after the riding rice transplanter changes direction, the driver operates the control lever to lower the ground work device and touch the work land (field), and then the driver operates the control lever again to resume power transmission to the ground work device.

[0006] In the configuration described in Patent Document 3, if it becomes necessary to perform seedling supply work or the like during work travel, the driver can stop the riding rice transplanter by operating the main shift lever to the forward / reverse switching path, and then can stop the engine by operating the main shift lever to the engine stop position. Then, after completing the seedling supply work or the like, the driver can restart the engine by operating the main shift lever from the engine stop position to the forward / reverse switching path, and then can move the riding rice transplanter forward by operating the main shift lever to the forward shift path. However, in the configuration described in Patent Document 3, the riding rice transplanter cannot be automatically traveled on the target path, so the driver needs to steer the riding rice transplanter so that it does not deviate from the target path.

[0007] There is a need for the development of work vehicles that can drive autonomously. [Means for solving the problem]

[0008] The work vehicle according to the present invention comprises: In addition, a work vehicle according to the present invention comprises a route setting unit that sets a target straight-line route, a positioning unit that measures the position and orientation of the traveling body, a direction control unit that controls the traveling direction of the traveling body, a transition detection unit that detects a transition in the traveling state of the traveling body, and a work control unit that switches a ground work device that is connected to the traveling body so that it can be raised and lowered between a working state and a non-working state, and in a control target area of ​​the target straight-line route, the direction control unit executes automatic straight-line control that causes the traveling body to automatically travel on the target straight-line route based on the target straight-line route and the positioning results of the positioning unit, and the work control unit executes non-working state switching control that switches the ground work device to the non-working state in conjunction with the transition detection unit detecting a transition from the straight-line state of the traveling body to a direction change state, and executes work state switching control that switches the ground work device to the working state in conjunction with the transition detection unit detecting a transition from the direction change state of the traveling body to the straight-line state.

[0009] According to this means, in the controlled area of ​​the target straight-line path, the vehicle body automatically travels along the target straight-line path due to the control operation of the directional control unit, so that the driver does not need to steer the vehicle body so that it does not deviate from the target straight-line path. Then, when the vehicle body leaves the control area of ​​the target straight-line path, the driver steers the vehicle body, and as the vehicle body reaches a direction change area in the work site, the driver initiates a direction change operation to move the vehicle body from the current target straight-line path to the next target straight-line path.The transition detection unit detects the transition of the vehicle body from a straight-line state to a direction change state, and the work control unit operates control based on this detection, and in conjunction with the transition of the vehicle body from the straight-line state to the direction change state, the ground work device switches from a working state to a non-working state. Thereafter, when the driver finishes the turning operation as the vehicle body reaches the next target straight-line path, the transition detection unit detects the transition of the vehicle body from a turning state to a straight-line state, and the work control unit operates control based on this detection, and the ground work device switches from a non-working state to a working state in conjunction with the transition of the vehicle body from the turning state to the straight-line state. In other words, in the control area of ​​the target straight-line path, automatic straight-line control is executed so that the vehicle body automatically travels along the target straight-line path, and in the direction change area, working state switching control and non-working state switching control are appropriately executed in conjunction with the driver's direction change operation so that the ground work device switches between working and non-working states at the appropriate timing. As a result, the effort required by the driver during work driving can be effectively reduced without causing a decrease in work efficiency.

[0010] As another means for solving the above problem, The work vehicle according to the present invention comprises a route setting unit that sets a target straight route, a positioning unit that measures the position and orientation of a traveling vehicle body, a direction control unit that controls the traveling direction of the traveling vehicle body, an engine control unit that controls the operation of an engine, and a condition determination unit that determines whether or not a temporary stop condition and a restart condition for the engine are satisfied; the direction control unit, in a control target area of ​​the target straight-line route, executes an automatic straight-line control for automatically driving the traveling vehicle body along the target straight-line route based on the target straight-line route and the positioning result of the positioning unit; the engine control unit executes an engine temporary stop control for temporarily stopping the engine when the condition determination unit determines that the temporary stop condition is satisfied, and executes an engine restart control for restarting the engine when the condition determination unit determines that the restart condition is satisfied; The direction control unit interrupts the automatic straight-line driving control when the engine temporary stop control is executed while the automatic straight-line driving control is being executed, and resumes the automatic straight-line driving control when the engine restart control is executed while the automatic straight-line driving control is interrupted.

[0011] According to this means, in the controlled area of ​​the target straight-line path, the vehicle body automatically travels along the target straight-line path due to the control operation of the directional control unit, so that the driver does not need to steer the vehicle body so that it does not deviate from the target straight-line path. Here, for example, suppose that a work vehicle is equipped with a storage section for storing materials to be delivered to a work site, and the engine temporary suspension condition is set to operation of the main shift lever from the neutral position to the engine stop position, and the engine restart condition is set to operation of the main shift lever from the engine stop position to the neutral position. In such a work vehicle, if it becomes necessary to replenish the supply to the storage section while the automatic straight-line control is being performed, for example, when the driver operates the main shift lever to the neutral position, the transmission to the traveling device is cut off and the traveling vehicle body stops traveling. When the driver then operates the main shift lever to the engine stop position, the condition determination section determines that the engine temporary stop condition is met, and the engine control section operates a control based on this determination to temporarily stop the engine. This allows the driver to quickly replenish the supply to the storage section while preventing fuel from being wasted during the replenishment work. In addition, since the direction control section interrupts the automatic straight-line control at this time, it is possible to prevent unnecessary power consumption caused by the automatic straight-line control continuing while the engine is temporarily stopped. Thereafter, when the driver finishes replenishing the supply to the storage section and operates the main shift lever from the engine stop position to the neutral position, the condition determination section determines whether the engine restart condition is met, and the engine control section operates to control the engine based on this determination, restarting the engine. When the driver then operates the main shift lever from the neutral position to a forward shift position, forward power is transmitted to the traveling device and the traveling vehicle body moves forward. During this forward traveling, the direction control section resumes the automatic straight traveling control in conjunction with the restart of the engine, so that the traveling vehicle body automatically travels along the target straight traveling path. As a result, it is possible to reduce the effort required by the driver during work driving while preventing unnecessary fuel consumption and power consumption.

[0012] As another means for solving the above problem, The work vehicle of the present invention comprises a path setting unit which sets a target straight path, a positioning unit which measures the position and orientation of the traveling body, a direction control unit which controls the traveling direction of the traveling body, a transition detection unit which detects a transition in the traveling state of the traveling body, a work control unit which switches a ground work device which is connected to the traveling body so as to be able to be raised and lowered between a working state and a non-working state, an engine control unit which controls the operation of an engine, and a condition determination unit which determines whether or not a temporary stop condition and a restart condition for the engine are satisfied, the direction control unit, in a control target area of ​​the target straight-line route, executes an automatic straight-line control for automatically driving the traveling vehicle body along the target straight-line route based on the target straight-line route and the positioning result of the positioning unit; the work control unit executes non-working state switching control for switching the ground work device to the non-working state in conjunction with the transition detection unit detecting a transition from a straight-ahead state to a direction-changing state of the traveling vehicle body, and executes work state switching control for switching the ground work device to the working state in conjunction with the transition detection unit detecting a transition from a direction-changing state of the traveling vehicle body to a straight-ahead state, the engine control unit executes an engine temporary stop control for temporarily stopping the engine when the condition determination unit determines that the temporary stop condition is satisfied, and executes an engine restart control for restarting the engine when the condition determination unit determines that the restart condition is satisfied; The direction control unit interrupts the automatic straight-line driving control when the engine temporary stop control is executed while the automatic straight-line driving control is being executed, and resumes the automatic straight-line driving control when the engine restart control is executed while the automatic straight-line driving control is interrupted.

[0013] According to this means, in the controlled area of ​​the target straight-line path, the vehicle body automatically travels along the target straight-line path due to the control operation of the directional control unit, so that the driver does not need to steer the vehicle body so that it does not deviate from the target straight-line path. Then, when the vehicle body leaves the control area of ​​the target straight-line path, the driver steers the vehicle body, and as the vehicle body reaches a direction change area in the work site, the driver initiates a direction change operation to move the vehicle body from the current target straight-line path to the next target straight-line path.The transition detection unit detects the transition of the vehicle body from a straight-line state to a direction change state, and the work control unit operates control based on this detection, and in conjunction with the transition of the vehicle body from the straight-line state to the direction change state, the ground work device switches from a working state to a non-working state. Thereafter, when the driver finishes the turning operation as the vehicle body reaches the next target straight-line path, the transition detection unit detects the transition of the vehicle body from a turning state to a straight-line state, and the work control unit operates control based on this detection, and the ground work device switches from a non-working state to a working state in conjunction with the transition of the vehicle body from the turning state to the straight-line state. In other words, in the control area of ​​the target straight-line path, automatic straight-line control is executed so that the vehicle body automatically travels along the target straight-line path, and in the direction change area, working state switching control and non-working state switching control are appropriately executed in conjunction with the driver's direction change operation so that the ground work device switches between working and non-working states at the appropriate timing. Here, for example, suppose that a work vehicle is equipped with a storage section for storing materials to be delivered to a work site, and the engine temporary suspension condition is set to operation of the main shift lever from the neutral position to the engine stop position, and the engine restart condition is set to operation of the main shift lever from the engine stop position to the neutral position. In such a work vehicle, if it becomes necessary to replenish the supply to the storage section while the automatic straight-line control is being performed, for example, when the driver operates the main shift lever to the neutral position, the transmission to the traveling device is cut off and the traveling vehicle body stops traveling. When the driver then operates the main shift lever to the engine stop position, the condition determination section determines that the engine temporary stop condition is met, and the engine control section operates a control based on this determination to temporarily stop the engine. This allows the driver to quickly replenish the supply to the storage section while preventing fuel from being wasted during the replenishment work. In addition, since the direction control section interrupts the automatic straight-line control at this time, it is possible to prevent unnecessary power consumption caused by the automatic straight-line control continuing while the engine is temporarily stopped. Thereafter, when the driver finishes replenishing the supply to the storage section and operates the main shift lever from the engine stop position to the neutral position, the condition determination section determines whether the engine restart condition is met, and the engine control section operates to control the engine based on this determination, restarting the engine. When the driver then operates the main shift lever from the neutral position to a forward shift position, forward power is transmitted to the traveling device and the traveling vehicle body moves forward. During this forward traveling, the direction control section resumes the automatic straight traveling control in conjunction with the restart of the engine, so that the traveling vehicle body automatically travels along the target straight traveling path. As a result, the effort required by the driver during work travel can be effectively reduced without causing a decrease in work efficiency and while preventing unnecessary fuel and power consumption.

[0014] As one of the means for making the present invention more suitable, The positioning unit includes a satellite navigation system and an inertial measurement system.

[0015] According to this means, for example, it becomes possible to correct accumulated errors contained in the relative position of the work vehicle obtained from an inertial measurement unit using the absolute position of the work vehicle obtained from a satellite navigation system. In addition, for example, by using a three-axis gyroscope equipped in an inertial measurement unit, it is possible to correct positioning errors of a satellite navigation system caused by misalignment of the GPS antenna due to the inclination of the traveling vehicle body. As a result, the position and orientation of the traveling vehicle body can be measured with high accuracy, and in the controlled area of ​​the target straight-line path, the traveling vehicle body can be caused to travel on the target straight-line path with high accuracy by the control operation of the direction control unit.

[0016] As one of the means for making the present invention more suitable, a manual main switch for turning on and off the power supply from the battery to each electrical device, and a power supply holding unit for enabling the power supply from the battery to the satellite navigation device by bypassing the main switch, The power holding unit switches to a power holding state in which power is supplied from the battery to the satellite navigation device in response to a cut-off operation of the main switch, and switches to a power stop state in which power is stopped from the battery to the satellite navigation device in response to a connect operation of the main switch.

[0017] In order to prevent unnecessary fuel consumption during breaks in work travel, the driver may shut off the main switch to cut off power from the battery to each electrical component and stop the engine. At this time, power to the satellite navigation device is usually also cut off, causing the satellite navigation device to stop operating. It is known that the satellite navigation device takes a long time to start up after the power supply to the satellite navigation device is started until the satellite-based positioning becomes possible. Therefore, for example, if the driver turns off the main switch to stop the engine in order to prevent unnecessary fuel consumption during a break, the satellite navigation device also stops operating. Therefore, even if the driver turns the main switch to start the engine after the break, the driver cannot resume work driving using the automatic straight-line control until the satellite navigation device starts up. As a result, waiting for the satellite navigation device to start up leads to a decrease in work efficiency, and if the driver resumes work driving without waiting for the satellite navigation device to start up, the driver is forced to make an effort to steer the riding rice transplanter so that it does not deviate from the target route.

[0018] Therefore, in this means, for example, in order to prevent unnecessary fuel consumption during a break, when the driver turns off the main switch to stop the engine, the power holding unit switches to a power holding state in conjunction with the main switch being turned off at that time, thereby maintaining the satellite navigation device in an operating state. As a result, when the driver finishes a break, for example, and operates the main switch to start the engine, work driving using the automatic straight ahead control can be resumed at the same time as the engine starts. As a result, it is possible to prevent unnecessary fuel consumption during rest periods, etc., without causing a decrease in work efficiency or an increase in the workload of the driver.

[0019] As one of the means for making the present invention more suitable, a manual main switch that turns on and off current supply from the battery to each electrical component, and a current supply holding unit that enables current supply from the battery to the inertial measurement unit, bypassing the main switch; The power holding unit switches to a power holding state in which power is passed from the battery to the inertial measurement unit in response to a disconnection operation of the main switch, and switches to a power stop state in which power is stopped from the battery to the inertial measurement unit in response to a connection operation of the main switch.

[0020] In order to prevent unnecessary fuel consumption during breaks in the work drive, the driver may shut off the engine by turning off the main switch to cut off the power supply from the battery to each electrical component. At this time, the power supply to the inertial measurement unit is usually also cut off, so that the inertial measurement unit also stops operating. It is known that the measurement accuracy of the gyroscope provided in the inertial measurement unit is not stable unless the gyroscope is warmed up. Therefore, for example, when the driver turns off the main switch to stop the engine in order to prevent unnecessary fuel consumption during a break, the inertial measurement unit also stops operating. Therefore, even if the driver operates the main switch to start the engine when the driver finishes a break, the driver cannot resume work travel using the automatic straight-line control until the warm-up operation of the gyroscope is completed. As a result, waiting for the warm-up operation of the gyroscope to be completed leads to a decrease in work efficiency, and when the driver resumes work travel without waiting for the warm-up operation to be completed, the driver is forced to make an effort to steer the riding rice transplanter so that it does not deviate from the target route.

[0021] Therefore, in this means, for example, when the driver turns off the main switch to stop the engine in order to prevent unnecessary fuel consumption during a break, the power holding unit switches to a power holding state in conjunction with the main switch being turned off at that time to maintain the inertial measurement unit in an operating state. As a result, when the driver finishes a break, for example, and operates the main switch to start the engine, work driving using the automatic straight-line control can be resumed at the same time as the engine starts. As a result, it is possible to prevent unnecessary fuel consumption during rest periods, etc., without causing a decrease in work efficiency or an increase in the workload of the driver.

[0022] As one of the means for making the present invention more suitable, The power holding unit switches to the power holding state in conjunction with the main switch being turned off and begins timing, and if the main switch is connected between switching to the power holding state and the elapse of a set time, the power holding unit switches from the power holding state to the power stop state in conjunction with the connection operation, and if the main switch is not connected between switching to the power holding state and the elapse of the set time, the power holding unit switches from the power holding state to the power stop state as the set time elapses.

[0023] According to this means, when the driver turns off the main switch upon completion of the work, the power holding unit automatically switches from a power holding state to a power stop state as the set time elapses, and power to the satellite navigation system or the inertial measurement system is stopped. As a result, for example, by setting the set time to a time longer than the longest time expected as a suspension time for the work drive, it is possible to prevent the power to the satellite navigation system or the inertial measurement system from being stopped during a suspension of the work drive due to a break or the like, while preventing the power to the satellite navigation system or the inertial measurement system from being wastefully continued even after the work is completed. As a result, it is possible to prevent unnecessary fuel consumption during breaks and the like, and also to suppress unnecessary power consumption after work is completed.

[0024] As one of the means for making the present invention more suitable, The set time is set in accordance with the importance of maintaining electrical continuity set for each electrical component that is maintained electrical continuity by the electrical continuity holding section, and the more important the electrical component is, the longer the set time is set.

[0025] This means can reduce battery consumption during breaks when the engine is stopped, compared to when the power-on hold time of electrical equipment for which it is important to keep it powered is the same as the power-on hold time of electrical equipment for which it is less important to keep it powered.

[0026] As one of the means for making the present invention more suitable, Equipped with an alarm device that notifies the driver of various information, the power supply holding unit supplies power from the battery to the notification device in the power supply holding state, and stops power supply to the notification device in the power supply stop state; The notification device notifies a driver of information relating to the power-on hold state during operation in the power-on hold state.

[0027] This means can inform the driver, for example, that the satellite navigation device or inertial measurement device is in a powered state by the power holding unit, or the remaining time until the power holding unit switches from the powered state to a power-stopped state.

[0028] As one of the means for making the present invention more suitable, A vehicle speed control unit controls a vehicle speed, and a transition estimation unit estimates a transition from a driving state of a driver to a work state other than driving, The vehicle speed control unit executes deceleration control to reduce the vehicle speed when the transition estimation unit estimates that the driver will transition to the other work state.

[0029] According to this means, the vehicle speed can be reduced by the deceleration control of the vehicle speed control unit from the stage at which the transition estimation unit estimates the transition of the driver from a driving state to a task other than driving. This makes it possible to reduce the time required for the traveling vehicle body to stop traveling when the driver performs an operation to stop the traveling vehicle body before switching from a driving state to another work state. As a result, the transition from an operating state to another working state can be carried out efficiently.

[0030] As one of the means for making the present invention more suitable, A first seat sensor is provided for detecting a change in load on the driver's seat, The transition estimation unit estimates a transition of the driver to the other work state when a reduction in load is detected based on detection by the first seat sensor.

[0031] According to this means, when the driver forgets to stop the traveling vehicle body and transitions from a driving state to another working state, the transition estimation unit estimates the driver's transition from the driving state to another working state based on the detection of the first seat sensor. Then, the vehicle speed control unit reduces the vehicle speed based on this estimation. This makes it possible to make the driver realize that he or she has forgotten to stop the traveling vehicle body, and to prompt the driver to perform the operation to stop the traveling vehicle body. Also, it is possible to shorten the time required for the traveling vehicle body to stop traveling after the driver performs the operation to stop the traveling vehicle body.

[0032] As one of the means for making the present invention more suitable, a second seat sensor that detects a rotational movement of a driver's seat that is rotatable about a vertical axis from a forward-facing reference position; The transition estimation unit estimates a transition of the driver to the other work state when a turning movement of the driver's seat from the reference position is detected based on detection by the second seat sensor.

[0033] According to this means, when the driver forgets to stop the traveling vehicle body and transitions from the driving state to another working state, the transition estimation unit estimates the transition of the driver from the driving state to the other working state based on the detection of the second seat sensor. Then, the vehicle speed control unit reduces the vehicle speed based on this estimation. This makes it possible to make the driver realize that he or she has forgotten to stop the traveling vehicle body, and to prompt the driver to perform the operation to stop the traveling vehicle body. Also, it is possible to shorten the time required for the traveling vehicle body to stop traveling after the driver performs the operation to stop the traveling vehicle body.

[0034] As one of the means for making the present invention more suitable, a storage section for storing a supply to be supplied to a work site, a remaining amount detection section for detecting a remaining amount in the storage section, and a notification section for notifying a driver when a detection value of the remaining amount detection section has decreased to a set value for replenishment, The transition estimation unit estimates that the driver will transition to the other work state when the detection value of the remaining amount detection unit falls to the set value.

[0035] According to this means, the transition estimation unit can estimate a transition from the driver's driving state to a replenishing work state in which the supply is replenished to the storage unit as another work state based on the detection by the remaining amount detection unit. Then, the vehicle speed control unit reduces the vehicle speed based on this estimation. This can shorten the time required for the traveling vehicle body to stop traveling when the driver stops traveling before switching from the driving state to the replenishing work state. As a result, the transition from the operating state to the replenishment work state can be carried out efficiently.

[0036] As one of the means for making the present invention more suitable, The remaining amount detection portion detects the remaining amount in the storage portion by calculation processing based on the positioning result of the positioning unit.

[0037] According to this means, the remaining amount detection unit detects the remaining amount in the storage unit based on, for example, the amount of supply stored in the storage unit, the amount of supply per unit distance, and the distance traveled at the work site obtained as the positioning result of the positioning unit. In other words, the remaining amount in the reservoir can be detected without providing a dedicated sensor for detecting the remaining amount of the supply as the remaining amount detection unit. As a result, the number of parts can be reduced, thereby simplifying the configuration.

[0038] As one of the means for making the present invention more suitable, A malfunction sensor detects the occurrence of a malfunction related to the work, and a notification unit notifies a driver of the occurrence of the malfunction, The transition estimation unit estimates a transition of the driver to the other work state when the malfunction sensor detects the occurrence of a malfunction.

[0039] According to this means, the transition estimation unit can estimate, based on the detection of the malfunction sensor, a transition from the driver's driving state to a maintenance work state for eliminating the malfunction detected by the malfunction sensor as another work state. Then, the vehicle speed control unit reduces the vehicle speed based on this estimation. This can shorten the time required for the traveling vehicle body to stop traveling when the driver stops traveling of the traveling vehicle body before the transition from the driving state to the maintenance work state. As a result, the transition from the operating state to the maintenance work state can be carried out efficiently.

[0040] As one of the means for making the present invention more suitable, A manual changeover switch is provided for switching the transition estimation unit between an active state and a stopped state.

[0041] According to this means, for example, when the driver determines that it is not necessary to perform other tasks such as replenishing the storage section with supplies, when a work drive is nearing the end of the drive, the transition estimation section can be switched to a stopped state, thereby avoiding a decrease in vehicle speed due to deceleration control by the vehicle speed control section. This makes it possible to avoid a decrease in work efficiency caused by a decrease in vehicle speed due to deceleration control by the vehicle speed control section when there is no need to perform other work.

[0042] As one of the means for making the present invention more suitable, A transition detection unit is provided for detecting a transition of a driver from a driving state to a work state other than driving, When the transition detection unit detects the driver's transition to the other work state, the vehicle speed control unit executes deceleration control to reduce the vehicle speed to zero speed.

[0043] According to this means, when the transition detection unit detects a transition from the driver's driving state to a work state other than driving, the vehicle speed control unit can perform deceleration control to bring the traveling vehicle body to a halt. This makes it possible to prevent the driver from performing any work other than driving while maintaining the traveling state of the traveling vehicle body.

[0044] As one of the means for making the present invention more suitable, A reserve storage section for storing a reserve of a supply to be supplied to a work site, and a reserve remaining amount sensor for detecting a decrease in the remaining amount in the reserve storage section, The transition detection unit detects the transition of the driver to the other work state when the reserve remaining amount sensor detects a decrease in the remaining amount.

[0045] According to this means, the transition detection unit can detect a transition from a driving state of the driver to a replenishing operation state in which the supply is replenished to the storage unit as another operation state based on detection by the reserve amount sensor, and the traveling vehicle body can be stopped by deceleration control of the vehicle speed control unit based on this detection. This makes it possible to prevent the driver from carrying out refueling work while the traveling state of the traveling vehicle body is maintained.

[0046] As one of the means for making the present invention more suitable, A manual changeover switch is provided for switching the transition detection unit between an active state and a stopped state.

[0047] According to this means, it is possible to switch between a state in which automatic stopping of the traveling vehicle body by deceleration control of the vehicle speed control unit based on detection by the transition detection unit and a state in which automatic stopping of the traveling vehicle body by deceleration control of the vehicle speed control unit is not adopted.

[0048] As one of the means for making the present invention more suitable, The vehicle includes a notification unit that notifies the driver that the deceleration control is being executed.

[0049] According to this means, when the vehicle speed is reduced due to the deceleration control of the vehicle speed control section, the driver can be notified of this by the notification section. This makes it possible to avoid the driver feeling uncomfortable when the vehicle speed is reduced by the deceleration control of the vehicle speed control section.

[0050] As one of the means for making the present invention more suitable, A point storage unit stores a turning start point at which the traveling vehicle body transitions from a straight-ahead state to a turning state, and an arrival determination unit determines whether the traveling vehicle body has reached the turning start point, The direction control unit executes automatic direction change control to automatically change the direction of the traveling vehicle body from a current target straight-line path to a next target straight-line path when the arrival determination unit determines that the traveling vehicle body has reached the turning start point.

[0051] According to this means, when the vehicle body reaches the turning start point, the control operation of the direction control unit causes the vehicle body to automatically change direction from the current target straight-line path to the next target straight-line path, eliminating the need for the driver to steer the vehicle body to change direction. As a result, the effort required by the driver during work driving can be further reduced.

[0052] As one of the means for making the present invention more suitable, A manual changeover switch is provided for changing the direction control unit between an execution state for executing the automatic direction change control and a non-execution state for not executing the automatic direction change control, When the direction control unit is switched to the execution state in a state in which the turning start point is not stored in the point storage unit, a notification unit is provided for notifying the driver that the turning start point is not stored in the point storage unit.

[0053] According to this means, even if the direction control unit is switched to an execution state in which automatic direction change control is performed by the change-over switch, if the change-over start point is not stored in the point memory unit, the arrival determination unit cannot determine that the traveling vehicle body has reached the change-over start point.As a result, even if the traveling vehicle body reaches the change-over start point, automatic direction change control is not executed by the direction control unit, and the driver can be notified of this by the notification unit. This allows the driver to determine when the traveling vehicle body has reached the turning start point, and to recognize that, as the traveling vehicle body reaches the turning start point, the traveling vehicle body needs to be moved from the current target straight-line path to the next target straight-line path by a manual direction change operation. As a result, it is possible to avoid a situation in which the driver mistakenly believes that the turning start point has already been stored in the point memory unit and that automatic direction change control will be executed by the direction control unit when the traveling vehicle body reaches the turning start point, resulting in failure to perform manual direction change operation even when the traveling vehicle body reaches the turning start point. [Brief description of the drawings]

[0054] [Figure 1] FIG. [Diagram 2] FIG. 2 is a schematic plan view showing the transmission configuration and steering configuration of the riding rice transplanter. [Diagram 3] FIG. 2 is a schematic plan view showing a transmission configuration for traveling. [Figure 4] FIG. 2 is a schematic plan view showing a transmission configuration for work. [Diagram 5] FIG. 4 is a cross-sectional plan view of essential parts showing the operation path of the main shift lever, etc. [Figure 6] FIG. 2 is a block diagram showing a control configuration. [Figure 7] FIG. 2 is a schematic circuit diagram showing a circuit configuration related to engine start and stop operations. [Figure 8] This is a plan view showing the preparatory travel stage of the riding rice transplanter, which secures each work travel path for around planting. [Figure 9]This is a plan view showing the state immediately before the riding rice transplanter turns from the work travel path for round trip planting to the work travel path for reciprocating planting. [Figure 10] FIG. 2 is a plan view showing the traveling state of the riding rice transplanter on a work traveling path for reciprocating planting. [Figure 11] This is a plan view showing the state immediately before the riding rice transplanter turns from the work travel path for round trip planting to the work travel path for circular planting. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0055] Hereinafter, as one example of a form for carrying out the present invention, an embodiment in which the present invention is applied to a riding rice transplanter, which is one example of a work vehicle, will be described with reference to the drawings.

[0056] In addition, the direction indicated by the arrow with the symbol F in FIG. 1 is the front side of the riding rice transplanter, and the direction indicated by the arrow with the symbol U is the upper side of the riding rice transplanter. In addition, the direction indicated by the arrow marked F in FIG. 2 is the front side of the riding rice transplanter, and the direction indicated by the arrow marked R is the right side of the riding rice transplanter.

[0057] As shown in Figure 1, the riding rice transplanter illustrated in this embodiment is equipped with a riding type four-wheel drive running body 1, a parallel four-link type link mechanism 2 connected to the rear of the running body 1 so that it can be raised and lowered and swung, a hydraulic lifting cylinder 3 that drives the link mechanism 2 to sway, an eight-row seedling planting device (an example of a ground work device Z) 4 that is rollably connected to the rear end of the link mechanism 2, and an eight-row fertilizer applicator (an example of a ground work device) 5 that extends from the rear end of the running body 1 to the seedling planting device 4. As a result, the riding rice transplanter is configured with mid-mount fertilization specifications that allow planting and fertilizing up to eight rows of seedlings. In addition, the riding rice transplanter can raise and lower the seedling planting device 4 and part of the fertilizer application device 5 by operating the lifting cylinder 3.

[0058] As shown in Figs. 1 to 4, the traveling vehicle body 1 includes, as a traveling device 6, left and right front wheels 6A as steerable driving wheels and left and right rear wheels 6B as non-steerable driving wheels. The traveling vehicle body 1 has an engine 7 mounted in a vibration-proof manner at its front part. Power from the engine 7 is belt-transmitted to a main transmission 8, and the power after being shifted by the main transmission 8 is branched into a power for traveling and a power for working inside a transmission case (hereinafter referred to as a T / M case) 9. The power for traveling is transmitted to a front wheel differential 11 through an auxiliary transmission 10 inside the T / M case 9. Then, the power for driving the front wheels out of the power for traveling is transmitted from the front wheel differential 11 through left and right differential shafts 12 and the like to the left and right front wheels 6A. Among the power for traveling, the power for driving the rear wheels is transmitted to the left and right rear wheels 6B via a transmission gear 13 that rotates integrally with the front wheel differential 11, a first external transmission shaft 15 extending from the T / M case 9 to the rear axle case 14, and a rear wheel transmission mechanism 16 built in the rear axle case 14. The rear wheel transmission mechanism 16 includes left and right side clutches 17 that interrupt the transmission to the left and right rear wheels 6B, and a reduction unit 18 that reduces the speed and transmits the power for driving the rear wheels to the left and right rear wheels 6B. On the other hand, the power for working is transmitted to the seedling planting device 4 via a one-way clutch 19, an inter-row transmission 20, and a first working clutch 21 built in the T / M case 9, and a second external transmission shaft 22 extending from the T / M case 9 to the seedling planting device 4.

[0059] A water-cooled gasoline engine is used for the engine 7. A hydrostatic continuously variable transmission is used for the main transmission 8. A gear-type transmission capable of changing speeds in two stages, a low speed state for work travel and a high speed state for transportation travel, is used for the sub transmission 10. A multi-plate friction clutch is used for each of the left and right side clutches 17, and a spring (not shown) is provided for biasing each side clutch 17 back to the connected state. A gear-type transmission capable of changing speeds in six stages is used for the inter-plant transmission 20.

[0060] As shown in Figures 1, 4 and 6, the seedling planting device 4 is switched between an operating state in which it operates with power from the traveling body 1 and a non-operating state in which it stops operating by cutting off the power from the traveling body 1 by intermittent operation of the first working clutch 21. The seedling planting device 4 is equipped with five leveling floats 23, an eight-row seedling carrier (one example of a storage section) 24, a lateral feed mechanism (not shown), a belt-type vertical feed mechanism 25, and eight planting mechanisms 26. As the traveling body 1 travels with the leveling floats 23 in a grounded state, they slide on the muddy surface of the paddy field to level the muddy surface of the seedling planting area. The seedling carrier 24 is formed so that eight rows of mat-shaped seedlings can be placed on it. The lateral feed mechanism reciprocates the seedling carrier 24 in the left and right directions with a constant stroke corresponding to the left and right width of the mat-shaped seedlings by the power from the traveling body 1. The vertical feed mechanism 25 vertically feeds each mat-like seedling on the seedling carrier 24 toward the lower end of the seedling carrier 24 at a predetermined pitch each time the seedling carrier 24 reaches the left or right stroke end. Each planting mechanism 26 is of a rotary type and is arranged in the left and right direction at a constant interval corresponding to the spacing between the planting rows. Then, each planting mechanism 26 cuts a predetermined amount of seedlings from the lower end of each mat-like seedling placed on the seedling carrier 24 by power from the traveling vehicle body 1, and plants them in the muddy part after the leveling. As a result, when the seedling planting device 4 is in operation, a predetermined amount of seedlings can be taken out from the mat-like seedlings placed on the seedling carrier 24 and planted in the muddy soil of the paddy field. The working width W of the seedling planting device 4 is the length obtained by multiplying the number of planting rows of the seedling planting device 4 by the distance between the rows.

[0061] As shown in Fig. 1, the seedling planting device 4 is provided with a float fulcrum shaft 27 that can rotate relative to both left and right ends. The rear sides of each ground leveling float 23 are supported by the free ends of five sets of support arms 28 that extend rearward and downward from the float fulcrum shaft 27 so that they can swing up and down.

[0062] As shown in Fig. 1, Fig. 6 and Fig. 8 to 11, the seedling planting device 4 is provided with left and right markers 29 that form a travel reference line on the muddy surface of the paddy field, and an electric marker motor 30 that drives the left and right markers 29 to swing up and down. The left and right markers 29 swing up and down between a storage position in which they stand along the seedling planting device 4 and an operating position in which they extend outward laterally from the seedling planting device 4 by operation of the marker motor 30. In the storage position, the left and right markers 29 have a rotating body 29A for forming the travel reference line provided at the free end of the marker 29 that leaves the muddy surface. In the operating position, the rotating body 29A of the left and right markers 29 penetrates the muddy surface, and forms a travel reference line L on the muddy surface to be used on a travel route adjacent to the current travel route as the left and right markers 29 travel on the current travel route.

[0063] As shown in FIG. 1 and FIG. 6, the fertilizer application device 5 includes a horizontally long hopper (an example of a storage unit) 31, four delivery mechanisms 32, an electric blower 33, eight fertilizer application hoses 34, and eight furrow formers 35. The hopper 31 stores granular or powdered fertilizer. Each delivery mechanism 32 is operated by power transmitted via a fertilizer application transmission mechanism 36. Each delivery mechanism 32 delivers a predetermined amount of fertilizer from the hopper 31 by operation. The blower 33 is operated by power from a battery 37 mounted on the traveling vehicle body 1. The blower 33 generates a conveying wind that conveys the fertilizer delivered by each delivery mechanism 32 toward the muddy surface of the paddy field by operation. Each fertilizer application hose 34 guides the fertilizer conveyed by the conveying wind to each furrow former 35. Each furrow former 35 is provided on each ground leveling float 23. Each furrow former 35 rises and falls together with each soil leveling float 23, and when each soil leveling float 23 is on the ground during work travel, it forms a fertilizer furrow in the muddy part of the rice paddy and guides fertilizer into the fertilizer furrow.

[0064] The fertilizer applicator 5 switches between an operating state in which the payout mechanisms 32 and the blower 33 are operating and a non-operating state in which the payout mechanisms 32 and the blower 33 are stopped by on-off operation of the second work clutch 38 provided in the fertilizer transmission mechanism 36 and on-off operation of the blower relay 39 provided in the electric circuit. In the operating state of the fertilizer applicator 5, a predetermined amount of fertilizer stored in the hopper 31 can be taken out at a time and supplied by burying it in the mud of the paddy field.

[0065] 1 to 3 and 6, the traveling vehicle body 1 is provided with a driving section 40 on the rear side. The driving section 40 is provided with a steering wheel 41 for steering the front wheels, a main speed change lever 42 that enables the main speed change device 8 to be operated for speed change, an auxiliary speed change lever 43 that enables the auxiliary speed change device 10 to be operated for speed change, a brake pedal 44 that enables the braking operation of the braking device 100, a first working lever 45 and a second working lever 46 that enable the raising and lowering operation and switching of the operating state of the seedling planting device 4, an annunciation device 47 that notifies the driver of various information such as the engine speed, and a driver's seat 48 that can be rotated around a vertical axis from a forward-facing standard position and is biased back to the standard position.

[0066] The brake pedal 44 automatically returns to the released position. The first working lever 45 is a swing type that can be swung to each operating position of planting, lowering, neutral, raising, and automatic, and is configured as a position holding type that can hold the position at each operating position. The second working lever 46 is a cross swing type that can be swung in the up-down direction and the front-back direction, and is configured as a neutral return type.

[0067] The notification device 47 is disposed in front of the steering wheel 41 of the driver's section 40. The notification device 47 includes a liquid crystal display section 47A and a plurality of notification sections 47B to 47H each of which is formed of an LED or a buzzer.

[0068] As shown in FIG. 2, the steering wheel 41 is interlocked with the left and right front wheels 6A via a steering gear 50 that rotates integrally with the steering wheel 41 via a steering shaft 49, a sector gear 51 that meshes with and interlocks with the steering gear 50, a steering member 52 that swings integrally with the sector gear 51, and left and right tie rods 54 that extend between the steering member 52 and operating arms 53 of the left and right front wheels 6A.

[0069] The traveling vehicle body 1 is provided with a side clutch operating mechanism 55 that operates the left and right side clutches 17 intermittently in conjunction with the operation of the steering wheel 41. The side clutch operating mechanism 55 is provided with left and right linking rods 57 that connect the steering member 52 and the operating arms 56 of the left and right side clutches 17 so that they can be interlocked. The left and right linking rods 57 are provided with long holes 57a at the linking points with the operating arms 56 that set the relationship between the operating angle θ of the steering member 52 and the intermittent operation of the left and right side clutches 17.

[0070] With the above configuration, when the driver turns the steering wheel 41 leftward from the straight-ahead position, the steering member 52 swings rightward from the straight-ahead position (reference angle) θo according to the amount of turning. As a result, the left and right front wheels 6A are steered leftward from the straight-ahead position according to the amount of turning of the steering wheel 41. In addition, the left and right side clutches 17 are maintained in an engaged state by the action of the springs of each side clutch 17 and the long holes 57a of each linking rod 57 until the steering member 52 reaches the first set angle θa on the right side from the straight-ahead position θo. After that, when the steering member 52 swings from the first set angle θa on the right side to the second set angle θb, the left side clutch 17 is switched from the engaged state to the disengaged state by the action of the left linking rod 57 and the left operating arm 56 in conjunction with the swing. On the other hand, the right side clutch 17 is maintained in an engaged state by the action of the spring of the right side clutch 17 and the long hole 57a of the right linking rod 57. As a result, as a turning state of the traveling body 1, a small left turning state can be obtained in which the transmission to the left rear wheel 6B located on the inside of the turn is cut off and the turning radius of the traveling body 1 is reduced.

[0071] In this left small turn state, when the driver turns the steering wheel 41 rightward toward the straight ahead position, the steering member 52 swings leftward toward the straight ahead position θo according to the amount of turning. As a result, the left and right front wheels 6A are steered toward the straight ahead position according to the amount of turning of the steering wheel 41. Then, when the steering member 52 swings from the right second set angle θb to the first set angle θa, the left side clutch 17 is switched from the disconnected state to the connected state by the action of the left linkage rod 57 and the spring of the left side clutch 17 in conjunction with the swing. On the other hand, the right side clutch 17 is maintained in the connected state by the action of the spring of the right side clutch 17 and the long hole 57a of the right linkage rod 57. Thereafter, the left and right side clutches 17 are maintained in a connected state by the action of the springs of each side clutch 17 and the long holes 57a of each connecting rod 57 until the steering member 52 reaches the straight ahead position θo from the first set angle θa on the right side.

[0072] Conversely, when the driver turns the steering wheel 41 rightward from the straight ahead position, the steering member 52 swings leftward from the straight ahead position (reference angle) θo in accordance with the amount of turning. As a result, the left and right front wheels 6A are steered from the straight ahead position to the right turn direction according to the amount of rotation of the steering wheel 41. The left and right side clutches 17 are maintained in an engaged state by the action of the springs of the side clutches 17 and the long holes 57a of the linking rods 57 until the steering member 52 reaches the first set angle θa on the left side from the straight ahead position θo. When the steering member 52 subsequently swings from the first set angle θa on the left side to the second set angle θb, the right side clutch 17 is switched from the engaged state to the disengaged state by the action of the right linking rod 57 and the right operating arm 56 in conjunction with the swing. On the other hand, the left side clutch 17 is maintained in an engaged state by the action of the springs of the left side clutch 17 and the long holes 57a of the left linking rod 57. As a result, the traveling vehicle body 1 can change direction to obtain a small right turn state in which the power transmission to the right rear wheel 6B located on the inside of the turn is interrupted and the turning radius of the traveling vehicle body 1 becomes small.

[0073] In this right small turn state, when the driver turns the steering wheel 41 leftward toward the straight ahead position, the steering member 52 swings rightward toward the straight ahead position θo according to the amount of turning. As a result, the left and right front wheels 6A are steered toward the straight ahead position according to the amount of turning of the steering wheel 41. Then, when the steering member 52 swings from the second set angle θb on the left side to the first set angle θa, the right side clutch 17 is switched from the disconnected state to the connected state by the action of the right linkage rod 57 and the spring of the right side clutch 17 in conjunction with the swing. On the other hand, the left side clutch 17 is maintained in the connected state by the action of the spring of the left side clutch 17 and the long hole 57a of the left linkage rod 57. Thereafter, the left and right side clutches 17 are maintained in a connected state by the action of the springs of each side clutch 17 and the long holes 57a of each connecting rod 57 until the steering member 52 reaches the straight ahead position θo from the first set angle θa on the left side.

[0074] As shown in Figures 8 to 11, in this riding rice transplanter, the turning radius in the small left and right turning state described above is basically set to half the length of the working width W of the seedling planting device 4. As a result, for example, in a seedling planting operation by reciprocating planting, when the planting travel on the current work traveling route R1a to R1d is completed and the traveling body 1 is turned from the current work traveling route R1a to R1d to the adjacent next work traveling route R1b to R1e in a direction changing area on the ridge, that is, when a so-called ridge-side turning is performed, the driver can easily perform the ridge-side turning by steering so that the traveling body 1 is turned in a small left or right state as the direction changing state.

[0075] 1, 5 and 6, the main speed change lever 42 is disposed adjacent to the left side of the steering wheel 41. The main speed change lever 42 is configured as a swing type that can be swung along a guide groove 58A of a guide plate 58. The main speed change lever 42 is configured as a position holding type that can hold the neutral position, each of the five forward speed change positions, and each of the three reverse speed change positions by a detent mechanism (not shown).

[0076] The guide groove 58A includes a forward / reverse switching path 58a oriented left and right to be the neutral position of the main shift lever 42, a forward shift path 58b extending forward from the right end of the forward / reverse switching path 58a, a reverse shift path 58c extending rearward from the left end of the forward / reverse switching path 58a, and an auxiliary path 58d extending leftward from the left end of the forward / reverse switching path 58a. The left end of the auxiliary path 58d is set to a work interruption position 58e.

[0077] The guide plate 58 is equipped with an interruption switch 58B that detects operation of the main speed change lever 42 to the work interruption position 58e, and a retainer 58C that enables the main speed change lever 42 to be held in the work interruption position 58e. A limit switch, a proximity switch, or the like can be used as the interruption switch 58B.

[0078] The main speed change lever 42 is linked to an operating shaft (not shown) of the main speed change device 8 via a main speed change mechanical linkage mechanism (not shown). The main speed change device 8 switches to a neutral state when the main speed change lever 42 is operated to a forward / reverse switching path 58a. The main speed change device 8 switches to a forward speed change state corresponding to the shift position of the main speed change lever 42 when the main speed change lever 42 is operated to any shift position on the forward speed change path 58b. The main speed change device 8 switches to a reverse speed change state corresponding to the operating position of the main speed change lever 42 when the main speed change lever 42 is operated to any shift position on the reverse speed change path 58c.

[0079] As shown in FIG. 1, the sub-shift lever 43 is disposed adjacent to the left side of the driver's seat 48 . The sub-speed change lever 43 is of a forward / backward swing type, and is configured as a position-holding type that can be switched between and hold a low-speed position for work travel and a high-speed position for transportation. The sub-speed change lever 43 is linked to an operating shaft (not shown) of the sub-speed change device 10 via a mechanical linkage mechanism (not shown) for sub-speed change. When the sub-speed change lever 43 is operated to the low-speed position, the sub-speed change device 10 switches to a low-speed state for work travel, and when the sub-speed change lever 43 is operated to the high-speed position, the sub-speed change device 10 switches to a high-speed state for transportation.

[0080] The traveling body 1 is equipped with a spare storage section 59 for storing spare mat-shaped seedlings. The spare storage section 59 is equipped with a support frame 59A that is in an inverted U shape when viewed from the front and extends upward from both the left and right ends of the front part of the traveling body 1, and spare seedling trays 59B (four on each side) supported on the left and right sides of the support frame 59A. As a result, eight mat-shaped seedlings can be stored as spare mat-shaped seedlings in the spare storage section 59, divided into four on each side.

[0081] As shown in Fig. 6 and Fig. 7, the traveling vehicle body 1 includes an electronic control unit (hereinafter referred to as ECU) 60 that controls the on-board electrical equipment. The ECU 60 is configured with a microprocessor including a CPU and an EEPROM. The ECU 60 and each electrical equipment are connected to each other so as to be able to communicate with each other or transmit power via an in-vehicle communication system such as a CAN (Controller Area Network) or a power line.

[0082] As shown in Fig. 7, this riding rice transplanter is provided with a manual main switch 61 that turns on and off the power supply from the battery 37 to each electrical component such as the ECU 60. The main switch 61 is a key-operated switch provided on the driving unit 40, which can be switched between an "OFF" position, an "ON" position, and a "START" position, can be held in the "OFF" position and the "ON" position, and is biased to return from the "START" position to the "ON" position.

[0083] As shown in Fig. 6 and Fig. 7, the ECU 60 is started by the current from the battery 37 obtained by the connection operation of the main switch 61 from the OFF position to the ON position. When the current from the battery 37 is cut off by the disconnection operation of the main switch 61 from the ON position to the OFF position, the ECU 60 maintains the current-carrying state by the self-holding circuit 60A provided therein. Then, the ECU 60 writes the total operating time of the engine 7 and various setting information at the time when the disconnection operation of the main switch 61 is performed in a non-volatile storage unit 60B. In addition, the ECU 60 starts timing by the timer unit 60C provided therein in conjunction with the disconnection operation of the main switch 61, and if the connection operation of the main switch 61 is not performed within the time from the disconnection operation of the main switch 61 until the elapse of the set time, the ECU 60 stops the current supply by the self-holding circuit 60A and stops operation.

[0084] The main switch 61 is connected to a starter unit 63 for starting the engine via a brake switch 62 which is an open / close switch. The brake switch 62 switches from an open state to a closed state in conjunction with the depression of the brake pedal 44 to the braking position, and switches from a closed state to an open state in conjunction with the release of the brake pedal 44 from the braking position. As a result, when starting the engine 7, the driver can depress the brake pedal 44 to the braking position, thereby enabling electricity to flow from the battery 37 to the starter unit 63 via the main switch 61. In this state, by performing an engine start operation by moving the main switch 61 to the START position, the starter unit 63 can be activated to start the engine 7.

[0085] As shown in Figures 1, 2 and 6, the traveling vehicle body 1 is equipped with a first lever sensor 64 that detects the operation position of the first working lever 45 in the forward / backward direction, a second lever sensor 65 that detects the operation of the second working lever 46 in the up / down and forward / backward directions, a third lever sensor 66 that detects the operation position of the main shift lever 42 in the forward / backward direction, a height sensor 67 that detects the up / down swing angle of the link mechanism 2 as the height position of the seedling planting device 4, a float sensor 68 that detects the up / down swing angle of the left and right center ground leveling floats (hereinafter referred to as center floats) 23, left and right marker sensors 69 that detect the switching of the left and right markers 29 to their stored positions and their operating positions, a steering angle sensor 70 that detects the swing operation angle of the steering member 52 from the straight-ahead position θo as the steering angle of the front wheels 6A, a rotation sensor 71 that detects the output speed of the engine 7, a voltage detector 72 that detects the voltage of the battery 37, and a water temperature sensor 73 that detects the temperature of the engine cooling water.

[0086] The first lever sensor 64, the third lever sensor 66, the height sensor 67, the float sensor 68, and the steering angle sensor 70 may be a rotary potentiometer or a rotary encoder. The second lever sensor 65 may be a multi-contact switch, or a limit switch unit having a plurality of limit switches. The left and right marker sensors 69 may be a limit switch unit having a limit switch that detects the marker 29 switching to the stored position and a limit switch that detects the marker 29 switching to the operating position, or a proximity switch unit having a proximity switch that detects the marker 29 switching to the stored position and a proximity switch that detects the marker 29 switching to the operating position. The rotation sensor 71 may be an electromagnetic pickup type or the like.

[0087] 6, the ECU 60 includes a lift control unit 60D that controls the operation of the lift cylinder 3 to lift and lower the seedling planting device 4. The lift control unit 60D controls the operation of the lift cylinder 3 by controlling the operation of a lift valve unit 74 that controls the flow of oil to the lift cylinder 3.

[0088] As shown in Figures 1 and 6, the lifting / lowering control unit 60D executes a first lifting / lowering control to lift and lower the seedling planting device 4 based on the outputs of the first lever sensor 64 and the height sensor 67 when the first working lever 45 is manually operated.

[0089] Hereinafter, the control operation of the lift control section 60D in the first lift control will be described. When the lifting control section 60D detects the operation of the first working lever 45 to the raised position based on the output of the first lever sensor 64, it performs a lifting process to lift the seedling planting device 4. In the lifting process, the lifting control section 60D switches the valve unit 74 to a supply state in which oil is supplied to the lifting cylinder 3, thereby contracting the lifting cylinder 3 and lifting the seedling planting device 4. When the lifting / lowering control unit 60D detects that the first work lever 45 has been operated to the lowered position based on the output of the first lever sensor 64, it performs a lowering process to lower the seedling planting device 4. In the lowering process, the lifting / lowering control unit 60D switches the valve unit 74 to a discharge state in which oil is discharged from the lifting / lowering cylinder 3, thereby extending the lifting / lowering cylinder 3 and lowering the seedling planting device 4. When the lifting / lowering control section 60D detects the operation of the first working lever 45 to the neutral position based on the output of the first lever sensor 64, it performs a lifting / lowering stop process to stop the seedling planting device 4 at the height position at that time. In the lifting / lowering stop process, the lifting / lowering control section 60D switches the valve unit 74 to a supply / discharge stop state that stops the supply / discharge of oil to the lifting / lowering cylinder 3, thereby stopping the extension / retraction operation of the lifting / lowering cylinder 3 and stopping the seedling planting device 4. When the lifting control unit 60D detects that the seedling planting device 4 has reached the upper limit position based on the output of the height sensor 67 while the aforementioned lifting process is being performed, it performs the aforementioned lifting stop process to stop the seedling planting device 4 at the upper limit position. When the lifting control unit 60D detects that the seedling planting device 4 has reached the lower limit position based on the output of the height sensor 67 while the above-mentioned lowering process is being performed, it performs the above-mentioned lifting stop process to stop the seedling planting device 4 at the lower limit position. In other words, by controlling the operation of the lifting / lowering control unit 60D based on the output of the first lever sensor 64, the operator can raise and lower the seedling planting device 4 to any height position between the upper limit position and the lower limit position by operating the first working lever 45.

[0090] When the lifting / lowering control unit 60D detects operation of the first working lever 45 to the automatic position based on the output of the first lever sensor 64, it executes a second lifting / lowering control to raise and lower the seedling planting device 4 based on the outputs of the second lever sensor 65, the height sensor 67, and the float sensor 68.

[0091] Hereinafter, the control operation of the lift control section 60D in the second lift control will be described. When the lifting control unit 60D detects the downward operation of the second working lever 46 based on the output of the second lever sensor 65, it performs an automatic lowering process to lower the seedling planting device 4 to the working height position corresponding to the control target angle of the center float 23, and when it detects the arrival of the seedling planting device 4 at the working height position based on the output of the float sensor 68, it starts an automatic lifting process to maintain the seedling planting device 4 at the working height position. In the automatic lowering process, the lifting control unit 60D performs the above-mentioned lowering process until it detects that the up-down swing angle of the center float 23 matches the control target angle based on the output of the float sensor 68 (the output of the float sensor 68 falls within the dead band width of the control target angle). In the automatic lifting process, the lifting control unit 60D controls the operation of the valve unit 74 to extend and retract the lifting cylinder 3 so that the state in which the output of the float sensor 68 matches the control target angle is maintained, thereby maintaining the seedling planting device 4 at the working height position. When the lifting control section 60D detects an upward operation of the second work lever 46 based on the output of the second lever sensor 65, it ends the automatic lifting process and performs an automatic raising process to raise the planting device 4 to the upper limit position. In the automatic raising process, the lifting control section 60D performs the above-mentioned raising process until it detects that the seedling planting device 4 has reached the upper limit position based on the output of the height sensor 67, and when it detects that the seedling planting device 4 has reached the upper limit position, it performs the above-mentioned lifting stop process to stop the seedling planting device 4 at the upper limit position. In other words, when the first work lever 45 is in the automatic position, the control operation of the lifting / lowering control unit 60D based on the output of the second lever sensor 65 allows the operator to operate the second work lever 46 to automatically lift or lower the seedling planting device 4 to the upper limit position or the working height position, and maintain the seedling planting device 4 at the upper limit position or the working height position. As a result, when the seedling planting device 4 is positioned at the working height during work travel, the seedling planting device 4 can be maintained at the working height corresponding to the control target angle of the center float 23, regardless of pitching of the traveling vehicle body 1 caused by the undulations of the paddy field tillage bed, etc.

[0092] The working height position of the seedling planting device 4 (the control target angle of the center float 23) can be arbitrarily changed by manually operating the working height setting device 75 provided in the driving unit 40. A rotary potentiometer or the like can be used as the setting device 75.

[0093] As shown in Fig. 6, the ECU 60 includes an operation control unit 60E that switches the seedling planting device 4 and the fertilizer application device 5 between an operating state and a stopped state. The operation control unit 60E controls the operation of the electric first clutch motor 76 that intermittently operates the first work clutch 21, the electric second clutch motor 77 that intermittently operates the second work clutch 38, and the blower relay 39, thereby switching the seedling planting device 4 and the fertilizer application device 5 between an operating state and a stopped state.

[0094] As shown in Figures 1 and 6, when the first operating lever 45 is manually operated, the operation control unit 60E executes a first operation switching control that switches the seedling planting device 4 and the fertilizer application device 5 between an operating state and a stopped state based on the outputs of the first lever sensor 64 and the float sensor 68.

[0095] Hereinafter, the control operation of the operation control section 60E in the first operation switching control will be described. When the operation control unit 60E detects that the first working lever 45 has been operated from the neutral position to the lowered position based on the output of the first lever sensor 64, and then detects that the center float 23 has been grounded based on the output of the float sensor 68, the operation control unit 60E performs a blower start-up process to start the blower 33. In the blower start-up process, the operation control unit 60E energizes the blower relay 39 and switches the blower relay 39 to a closed state that allows electricity to be passed from the battery 37 to the blower 33, thereby starting the blower 33. Thereafter, when the operation control unit 60E detects the operation of the first work lever 45 to the planting position based on the output of the first lever sensor 64, it performs an operation start process to switch the seedling planting device 4 and the fertilizer application device 5 from the stopped state to the operating state. In the operation start process, the operation control unit 60E controls the operation of the first clutch motor 76 and the second clutch motor 77 to switch the first work clutch 21 and the second work clutch 38 from the OFF state to the ON state, thereby switching the seedling planting device 4 and the fertilizer application device 5 from the stopped state to the operating state. Thereafter, when the operation control unit 60E detects the operation of the first work lever 45 from the planting position to the lowered position based on the output of the first lever sensor 64 in the operating state of the seedling planting device 4 and the fertilizer application device 5, it performs a blower stop process to stop the blower 33 and an operation stop process to switch the seedling planting device 4 and the fertilizer application device 5 from the operating state to the stopped state. In the blower stop process, the operation control unit 60E stops the power supply to the blower relay 39 and switches the blower relay 39 to an open state that blocks the power supply from the battery 37 to the blower 33, thereby stopping the blower 33. In the operation stop process, the operation control unit 60E controls the operation of the first clutch motor 76 and the second clutch motor 77 to switch the first work clutch 21 and the second work clutch 38 from the on state to the off state, thereby switching the seedling planting device 4 and the fertilizer application device 5 from the operating state to the stopped state. In other words, by controlling the operation of the operation control unit 60E based on the output of the first lever sensor 64, the driver can switch the seedling planting device 4 and the fertilizer application device 5 between an operating state and a stopped state by operating the first working lever 45.

[0096] When the operation control unit 60E detects operation of the first working lever 45 to the automatic position based on the output of the first lever sensor 64, it executes a second operation switching control to switch the seedling planting device 4 and the fertilizer application device 5 between an operating state and a stopped state based on the output of the second lever sensor 65, etc.

[0097] Hereinafter, the control operation of the operation control section 60E in the second operation switching control will be described. The operation control section 60E performs the above-mentioned blower start process when it detects the first operation of the second operation lever 46 downward for the first time based on the output of the second lever sensor 65 after detecting the operation of the first operation lever 45 to the automatic position based on the output of the first lever sensor 64, or after detecting the upward operation of the second operation lever 46 based on the output of the second lever sensor 65. Thereafter, when it detects the second downward operation of the second operation lever 46 based on the output of the second lever sensor 65, it performs the above-mentioned operation start process in conjunction with detecting the arrival of the seedling planting device 4 at the working height position based on the output of the float sensor 68. When the operation control unit 60E detects upward operation of the second work lever 46 based on the output of the second lever sensor 65 while the seedling planting device 4 and the fertilizer application device 5 are in operation, it performs the blower stop processing and operation stop processing described above. In other words, when the first working lever 45 is in the automatic position, the operation of the operation control unit 60E based on the output of the second lever sensor 65 allows the driver to switch the seedling planting device 4 and the fertilizer application device 5 between an operating state and a stopped state by operating the second working lever 46.

[0098] 6, the ECU 60 includes a marker control unit 60F that switches the left and right markers 29 between a stored posture and an active posture. The marker control unit 60F controls the operation of the left and right marker motors 30 to switch the left and right markers 29 between the stored posture and the active posture.

[0099] As shown in Figures 1 and 6, when the second operating lever 46 is manually operated, the marker control unit 60F executes marker switching control to switch the left and right markers 29 between a stored position and an operating position based on the outputs of the second lever sensor 65, the float sensor 68, and the left and right marker sensors 69.

[0100] The control operation of the marker control unit 60F in the marker switching control will be described below. When the marker control unit 60F detects the operation of the second working lever 46 from the neutral position to the left based on the output of the second lever sensor 65, it judges whether the seedling planting device 4 has descended to the working height position based on the output of the float sensor 68. If the seedling planting device 4 has descended to the working height position, the marker control unit 60F immediately performs a left marker extension process to switch the left marker 29 to the working position. If the seedling planting device 4 has not descended to the working height position, the marker control unit 60F performs a left marker extension process in response to detecting the descent of the seedling planting device 4 to the working height position. In the left marker extension process, the marker control unit 60F operates the left marker motor 30 in the forward direction until the left marker sensor 69 detects the switching of the left marker 29 to the working position. When the marker control unit 60F detects the operation of the second working lever 46 from the neutral position to the right based on the output of the second lever sensor 65, it judges whether the seedling planting device 4 has descended to the working height position based on the output of the float sensor 68. If the seedling planting device 4 has descended to the working height position, the marker control unit 60F immediately performs a right marker extension process to switch the right marker 29 to the working position. If the seedling planting device 4 has not descended to the working height position, the marker control unit 60F performs a right marker extension process in response to detecting the descent of the seedling planting device 4 to the working height position. In the right marker extension process, the marker control unit 60F operates the right marker motor 30 in the forward direction until the right marker sensor 69 detects the switching of the right marker 29 to the working position. When the marker control unit 60F detects the floating of the seedling planting device 4 based on the output of the float sensor 68 while either the left or right marker 29 is switched to the working position, the marker control unit 60F performs a marker storage process to switch the marker 29 from the working position to the stored position. In the marker storage process, the marker control unit 60F reversely operates the marker motor 30 corresponding to the marker 29 in the working position until the marker sensor 69 corresponding to the marker 29 in the working position detects the switch of the marker 29 to the stored position. That is, the driver can switch the left and right markers 29 to the working position when the seedling planting device 4 is in the grounded state by operating the second work lever 46 through the control operation of the marker control unit 60F based on the outputs of the second lever sensor 65, the float sensor 68, and the left and right marker sensors 69. Also, the marker 29 in the working position can be automatically switched to the stored position as the seedling planting device 4 floats up through the control operation of the marker control unit 60F based on the outputs of the float sensor 68 and the left and right marker sensors 69.

[0101] 2, 5 and 6, the ECU 60 includes a work control unit 60G that switches the seedling planting device 4 and the fertilizer application device 5 between an operating state and a non-operating state based on the detection of the interrupt switch 58B or the steering angle sensor 70. The work control unit 60G outputs control commands to the lift control unit 60D, the operation control unit 60E, and the marker control unit 60F to switch the seedling planting device 4 and the fertilizer application device 5 between an operating state and a non-operating state.

[0102] The work control unit 60G executes a first non-working state switching control to switch the seedling planting device 4 and the fertilizer application device 5 to a non-working state in conjunction with the interruption switch 58B detecting movement of the main shift lever 42 to the work interruption position 58e, and also executes a first working state switching control to switch the seedling planting device 4 and the fertilizer application device 5 to a working state in conjunction with the interruption switch 58B detecting movement of the main shift lever 42 from the work interruption position 58e.

[0103] First, the control operation of the work control section 60G in the first non-working state switching control will be described. When the work control unit 60G detects the movement of the main speed change lever 42 to the work interruption position 58e based on the detection of the interruption switch 58B while the seedling planting device 4 and the fertilizer application device 5 are in the working state, it determines whether the left or right marker 29 is in the working position based on the output of the left and right marker sensors 69, and stores the determination result in the memory unit 60B. Also, it determines whether the operating position of the first work lever 45 is the planting position or the automatic position based on the output of the first lever sensor 64. If the operating position of the first work lever 45 is the planting position, the lifting control unit 60D is instructed to execute the automatic lifting process described above, the operation control unit 60E is instructed to execute the blower stop process and operation stop process described above, and the marker control unit 60F is instructed to execute the marker storage process described above. If the operation position of the first work lever 45 is the automatic position, in addition to the control operation at the planting position described above, the lift control section 60D is instructed to end the automatic lift process described above. As a result, in conjunction with the swinging operation of the main shift lever 42 to the work interruption position 58e, the seedling planting device 4 and the fertilizer application device 5 can be automatically switched to a non-working state in which the seedling planting device 4 is positioned at the upper limit position, the seedling planting device 4 and the fertilizer application device 5 are stopped, and the left and right markers 29 are in a stored position.

[0104] Next, the control operation of the work control section 60G in the first work state switching control will be described. When the work control unit 60G detects movement of the main shift lever 42 from the work interruption position 58e based on detection of the interruption switch 58B while the seedling planting device 4 and the fertilizer application device 5 are not in operation, it determines whether the operating position of the first work lever 45 is the planting position or the automatic position based on the output of the first lever sensor 64. If the operation position of the first working lever 45 is the planting position, it commands the lift control unit 60D to execute the automatic lowering process described above, and then, when it detects the grounding of the center float 23 based on the output of the float sensor 68, it commands the operation control unit 60E to execute the blower start process described above. Then, when it detects that the seedling planting device 4 has reached the working height based on the output of the float sensor 68, it commands the operation control unit 60E to execute the operation start process described above, and also commands the marker control unit 60F to execute the right marker extension process or left marker extension process described above to return one of the left and right markers 29 stored as the working position in the memory unit 60B to the working position. If the operating position of the first working lever 45 is the automatic position, in addition to the control operation at the planting position described above, when it is detected that the seedling planting device 4 has reached the working height position, the lifting / lowering control unit 60D is instructed to execute the automatic lifting / lowering process described above. As a result, in conjunction with the swinging operation of the main shift lever 42 from the work interruption position 58e, the seedling planting device 4 and the fertilizer application device 5 can be automatically switched to a working state in which the seedling planting device 4 is located at the working height position, the seedling planting device 4 and the fertilizer application device 5 are in an operating state, and the marker 29 on the same side as the left or right marker 29 that was in an operating position during work travel before work was interrupted is in an operating position.

[0105] In other words, if it becomes necessary to perform auxiliary work such as supplying seedlings to the seedling planting device 4 or supplying fertilizer to the fertilizer application device 5 during seedling planting work, the driver can stop the traveling vehicle body 1 from traveling and switch the seedling planting device 4 and the fertilizer application device 5 from a working state to a non-working state by operating the main shift lever 42 to the neutral position or by depressing the brake pedal 44, and then operating the main shift lever 42 to the work interruption position 58e. This allows the operator to quickly transition from the operating state to the auxiliary operation state where auxiliary operations such as seedling supply or fertilizer supply are performed. When the seedling planting device 4 is in the non-operating state, the seedling planting device 4 rises to the upper limit position and the seedling carrier 24 approaches the driving unit 40, making it easier for the operator to supply seedlings to the seedling carrier 24 from the driving unit 40. Then, when the auxiliary work is completed, the driver operates the main shift lever 42 from the work interruption position 58e to the forward shift path 58b via the neutral position, and in conjunction with the operation of the main shift lever 42 from the work interruption position 58e to the neutral position, the seedling planting device 4 and the fertilizer application device 5 can be switched from a non-working state to the same working state as before the work was interrupted, and in conjunction with the operation of the main shift lever 42 from the neutral position to the forward shift path 58b, the traveling vehicle body 1 can be caused to travel forward and the seedling planting device 4 and the fertilizer application device 5 can be driven. This enables the operator to quickly and easily resume seedling planting work after it has been interrupted by auxiliary work.

[0106] The work control unit 60G switches between an execution state in which a control operation based on detection by the steering angle sensor 70 is executed and a non-execution state in which the control operation is not executed, based on the operation of a manual first changeover switch 78 provided in the driving unit 40. A toggle switch, a push button switch, or the like can be used as the first changeover switch 78.

[0107] The steering angle sensor 70 detects the swing of the steering member 52 from the straight-ahead position θo to the second set angle θb on the right side as a transition of the traveling vehicle body 1 from a straight-ahead state to a small left turn state (an example of a direction change state), and detects the swing of the steering member 52 from the second set angle θb on the right side to the first set angle θa as a transition of the traveling vehicle body 1 from the small left turn state to a straight-ahead state. The steering angle sensor 70 also detects the swing of the steering member 52 from the straight-ahead position θo to the second set angle θb on the left side as a transition of the traveling vehicle body 1 from a straight-ahead state to a small right turn state (an example of a direction change state), and detects the swing of the steering member 52 from the second set angle θb on the left side to the first set angle θa as a transition of the traveling vehicle body 1 from the small right turn state to a straight-ahead state. In other words, the steering angle sensor 70 functions as a transition detection unit that detects a transition in the traveling state of the traveling vehicle body 1.

[0108] In its execution state, the work control unit 60G executes a second non-working state switching control to switch the seedling planting device 4 and the fertilizer application device 5 to a non-working state in conjunction with the steering angle sensor 70 detecting a transition of the running body 1 from a straight-line state to a small turning state, and also executes a second working state switching control to switch the seedling planting device 4 and the fertilizer application device 5 to a working state in conjunction with the steering angle sensor 70 detecting a transition of the running body 1 from a small turning state to a straight-line state.

[0109] First, the control operation of the work control section 60G in the second non-working state switching control will be described. When the work control unit 60G detects a transition of the traveling body 1 from a straight-ahead state to a small left turn state or a small right turn state based on detection by the steering angle sensor 70 during the working state of the seedling planting device 4 and the fertilizer application device 5, it determines whether the operating position of the first work lever 45 is the planting position or the automatic position based on the output of the first lever sensor 64. If the operating position of the first work lever 45 is the planting position, the lifting control unit 60D is instructed to execute the automatic lifting process described above, the operation control unit 60E is instructed to execute the blower stop process and operation stop process described above, and the marker control unit 60F is instructed to execute the marker storage process described above. If the operation position of the first work lever 45 is the automatic position, in addition to the control operation at the planting position described above, the lift control section 60D is instructed to end the automatic lift process described above. This allows the seedling planting device 4 and the fertilizer application device 5 to be automatically switched to the non-working state described above in conjunction with the transition of the traveling vehicle body 1 from a straight-ahead state to a small left turn state or a small right turn state.

[0110] Next, the control operation of the work control section 60G in the second work state switching control will be described. When the work control unit 60G detects a transition of the traveling body 1 from a small left turn state or a small right turn state to a straight-ahead state based on detection by the steering angle sensor 70 while the seedling planting device 4 and the fertilizer application device 5 are in a non-working state, it determines whether the operating position of the first work lever 45 is the planting position or the automatic position based on the output of the first lever sensor 64. If the operation position of the first work lever 45 is the planting position, it commands the lift control unit 60D to execute the automatic lowering process described above, and then, when it detects the grounding of the center float 23 based on the output of the float sensor 68, it commands the operation control unit 60E to execute the blower start process described above. Then, when it detects that the seedling planting device 4 has reached the working height based on the output of the float sensor 68, it commands the operation control unit 60E to execute the operation start process described above, and commands the marker control unit 60F to execute the right marker extension process or left marker extension process described above to switch the marker 29 on the opposite side to the turning direction of the traveling body 1 to the working position. If the operating position of the first working lever 45 is the automatic position, in addition to the control operation at the planting position described above, when it is detected that the seedling planting device 4 has reached the working height position, the lifting / lowering control unit 60D is instructed to execute the automatic lifting / lowering process described above. As a result, in conjunction with the transition of the traveling vehicle body 1 from a small left turn state or a small right turn state to a straight-ahead state, the seedling planting device 4 and the fertilizer application device 5 can be automatically switched to a working state in which the seedling planting device 4 is positioned at the working height position, the seedling planting device 4 and the fertilizer application device 5 are in an operating state, and the marker 29 opposite to the left or right marker 29 that was in an operating position during working travel before the field edge turn is in an operating position.

[0111] In other words, when performing seedling planting work by reciprocating planting, the driver can operate the first change-over switch 78 to switch the work control unit 60G to the execution state, and then, at the edge of the field, simply by steering the traveling vehicle body 1 to turn around the edge of the field, the seedling planting device 4 and fertilizer application device 5 can be switched from a working state to a non-working state as the edge of the field turns begins, and also, as the edge of the field turns ends, the seedling planting device 4 and fertilizer application device 5 can be switched from a non-working state to a working state suitable for work on the next work travel route R1a-R1e.

[0112] As shown in FIGS. 5 to 7, the ECU 60 includes an engine control unit 60H that controls the operation of the engine 7, and a condition determination unit 60K that determines whether or not a temporary stop condition and a restart condition for the engine 7 are met.

[0113] The engine control unit 60H executes engine temporary stop control to temporarily stop the engine 7 when the condition determination unit 60K determines that the temporary stop condition of the engine 7 is satisfied. Also, the engine control unit 60H executes engine restart control to restart the engine 7 when the condition determination unit 60K determines that the restart condition of the engine 7 is satisfied.

[0114] In engine temporary stop control and engine restart control, the engine control unit 60H performs temporary stop or restart operation of the engine 7 by controlling the operation of a starter relay 80, which enables current to flow from the battery 37 to the starter unit 63, bypassing the main switch 61, and an igniter relay 81, which interrupts the flow of current from the battery 37 to the igniter 7A of the engine 7.

[0115] The starter relay 80 is connected to the starter unit 63 via the brake switch 62, similar to the main switch 61. As a result, similar to the start operation of the engine 7 by the main switch 61, the restart operation of the engine 7 based on the engine restart control of the engine control unit 60H also requires the driver to depress the brake pedal 44 to the braking position.

[0116] The condition determination unit 60K determines that the engine 7 temporary stop condition is satisfied if the conditions suitable for restarting the engine 7 are secured, for example, the output speed of the engine 7 is equal to or lower than a set speed (e.g., idling speed), the voltage of the battery 37 is equal to or higher than a set value, and the temperature of the engine coolant is equal to or higher than a set value (e.g., 55 degrees), after the interruption switch 58B detects the movement of the main shift lever 42 to the work interruption position 58e, and otherwise determines that the engine 7 temporary stop condition is not satisfied. Furthermore, while the interruption switch 58B has not detected the movement of the main shift lever 42 from the work interruption position 58e, the condition determination unit 60K determines that the engine 7 restart condition is not satisfied, and when the interruption switch 58B detects the movement of the main shift lever 42 from the work interruption position 58e, the condition determination unit 60K determines that the engine 7 restart condition is satisfied.

[0117] The condition determination unit 60K determines whether the output speed of the engine 7 is equal to or lower than a set speed based on the output of the rotation sensor 71. The condition determination unit 60K determines whether the voltage of the battery 37 is equal to or higher than a set value based on the output of the voltage detector 72. The condition determination unit 60K determines whether the temperature of the engine coolant is equal to or higher than a set value based on the output of the water temperature sensor 73.

[0118] The control operation of engine control section 60H during engine temporary stop control will now be described. When the engine control unit 60H detects that the temporary stop condition for the engine 7 has been met based on the judgment of the condition judgment unit 60K, it lights up the first notification unit 47B consisting of an LED provided in the notification device 47, and temporarily stops the engine 7 by passing current through the igniter relay 81 and switching the igniter relay 81 to an open state which stops the passage of current from the battery 37 to the igniter 7A. As a result, when the driver stops the vehicle body 1 to perform auxiliary work such as supplying seedlings or fertilizer, the driver can temporarily stop the engine 7 by operating the main shift lever 42 to the work interruption position 58e while performing a stopping operation such as operating the main shift lever 42 to the neutral position or depressing the brake pedal 44.As a result, it is possible to prevent unnecessary fuel consumption caused by the engine 7 continuing to run while auxiliary work such as supplying seedlings or fertilizer is being performed. Furthermore, even if the main shift lever 42 is operated to the work interruption position 58e, if the above-mentioned temporary suspension condition is not met, the engine 7 will not be temporarily suspended. This makes it possible to avoid the risk of inconvenience such as time consuming restarting the engine 7 caused by the engine 7 being temporarily suspended when, for example, the voltage of the battery 37 is below a set value or the temperature of the engine cooling water is below a set value. The driver can easily determine, from the state of the first notification section 47B, whether or not the engine 7 has been temporarily stopped by operating the main shift lever 42 to the work interruption position 58e.

[0119] Next, the control operation of the engine control section 60H during the engine restart control will be described. When the engine control unit 60H detects that the restart condition for the engine 7 is satisfied based on the determination by the condition determination unit 60K, it performs engine restart processing in response to the detection. In the engine restart process, first, the supply of electricity to the igniter relay 81 is stopped and the igniter relay 81 is switched to a closed state in which electricity is supplied from the battery 37 to the igniter 7A, thereby allowing the start of the engine 7. Next, electricity is supplied to the starter relay 80 and the starter relay 80 is switched to a closed state in which electricity is supplied from the battery 37 to the starter unit 63, thereby operating the starter unit 63 by supplying electricity from the battery 37 to the starter unit 63, bypassing the main switch 61, thereby restarting the engine 7. After the engine restart process is performed, it is determined whether the output speed of the engine 7 is equal to or higher than the set speed based on the output of the rotation sensor 71. If it is less than the set speed, it is determined that the engine 7 has not been restarted and the engine restart process is performed again. If it is equal to or higher than the set speed, it is determined that the restart of the engine 7 has been completed and the first notification unit 47B is turned off. This allows the driver, after completing the auxiliary work, to easily restart the engine 7 by operating the main shift lever 42 from the work interruption position 58e to the neutral position while depressing the brake pedal 44 to the braking position. The driver can easily determine, from the state of the first notification section 47B, whether or not the engine 7 has been restarted by operating the main shift lever 42 from the work interruption position 58e to the neutral position.

[0120] 2 and 6, the traveling vehicle body 1 is equipped with an automatic steering unit 83 that enables automatic steering of the left and right front wheels 6A. The automatic steering unit 83 is equipped with an electric steering motor 84, a gear mechanism 85 that transmits power from the steering motor 84 to the steering shaft 49, and the like.

[0121] 1 and 6, the traveling vehicle body 1 is equipped with a positioning unit 86 that measures its position and orientation. The positioning unit 86 includes a satellite navigation device 87 that measures the position and orientation of the traveling vehicle body 1 using a well-known Global Positioning System (GPS), which is an example of a Global Navigation Satellite System (GNSS), and an Inertial Measurement Unit (IMU) that has a three-axis gyroscope (not shown) and a three-directional acceleration sensor (not shown) and measures the roll angle, pitch angle, and yaw angle of the traveling vehicle body 1. It is equipped with Unit)88.

[0122] The satellite navigation device 87 is supported on the upper end portion 59C of the reserve storage section 59 located at the top of the traveling body 1 so that the reception sensitivity of the GPS antenna 87A to radio waves from the satellite is increased. Therefore, the positioning result by the satellite navigation device 87 includes a positioning error caused by the position shift of the GPS antenna 87A due to the inclination of the traveling body 1. Therefore, this riding rice transplanter is provided with an inertial measurement device 88 to correct the positioning error of the satellite navigation device 87 caused by the position shift of the GPS antenna 87A due to the inclination of the traveling body 1. Furthermore, by providing a satellite navigation system 87 and an inertial measurement system, it becomes possible to correct accumulated errors contained in the relative position of the running vehicle body 1 obtained from the inertial measurement system 88, for example, using the absolute position of the running vehicle body 1 obtained from the satellite navigation system 87. In other words, by providing the satellite navigation system 87 and the inertial measurement system, the position and orientation of the traveling vehicle body 1 can be measured with high accuracy.

[0123] The inertial measurement unit 88 is disposed in the center of the left and right of the rear axle case 14, which has high rigidity.

[0124] As shown in FIG. 6 and FIGS. 8 to 11, the ECU 60 includes a path setting unit 60L that sets a target straight path Rs, and a direction control unit 60M that controls the traveling direction of the traveling vehicle body 1.

[0125] When the first switch 89 and the second switch 90 for teaching provided on the driving unit 40 are pressed, the route setting unit 60L executes teaching control based on the operation to determine the reference orientation of the traveling body 1 when performing reciprocating planting in a paddy field.

[0126] The control operation of the path setting section 60L in the teaching control will be described below. When the route setting section 60L detects that the first switch 89 has been pressed while the vehicle is traveling, the route setting section 60L registers the measurement result obtained by the positioning unit 86 at this time as the teaching start end position Pta. Next, when the pressing operation of the second switch 90 is detected during movement and travel, the measurement result of the positioning unit 86 obtained at this time is registered as the teaching end position Ptb. Then, the extension direction of a straight line passing through the registered teaching start position Pta and teaching end position Ptb is determined as the above-mentioned reference direction Ro and written into the storage unit 60B. As a result, for example, during the preparatory driving stage before starting work driving to secure each work driving path R2a-R2d for detouring planting along the ridges, the driver can easily obtain the reference orientation Ro suitable for the rice paddy being worked on by pressing the first switch 89 and the second switch 90 when driving straight along the work driving paths R2a, R2c for detouring planting that run along the work driving paths R1a-R1e for reciprocating planting, thereby causing the path setting unit 60L to execute teaching control.

[0127] The first switch 89 and the second switch 90 may be momentary switches or the like.

[0128] The path setting unit 60L switches between an execution state in which the target path setting control that sets the target straight path Rs and a non-execution state in which the target path setting control is not executed, based on the operation of a manual second changeover switch 91 provided on the main shift lever 42. A momentary switch, a two-position toggle switch, or the like can be used as the second changeover switch 91.

[0129] When the target route setting control is being executed, when the steering angle sensor 70 detects a transition of the traveling body 1 from a straight-line state to a small turning state, the route setting unit 60L sets a target straight route Rs along the reference orientation Ro written in the memory unit 60B at a position on the turning direction side, a set distance (for example, a distance corresponding to the working width W of the seedling planting device 4) perpendicular to the straight route just before the turn, based on this detection.

[0130] In the control target area Rsa of the target straight-line route Rs set by the route setting unit 60L, the direction control unit 60M performs automatic straight-line control to automatically drive the traveling vehicle body 1 along the target straight-line route Rs based on the target straight-line route Rs and the positioning results of the positioning unit 86, etc.

[0131] The control operation of the direction control section 60M during the automatic straight ahead control will now be described. The direction control unit 60M first determines, based on the target straight-line route Rs and the positioning results of the positioning unit 86, the amount and direction of deviation of the current position of the traveling vehicle body 1 from the target straight-line route Rs, and the angle and direction of deviation of the current orientation of the traveling vehicle body 1 from the target straight-line route Rs, as deviation information. Next, the control target steering angles of the left and right front wheels 6A are determined based on the obtained deviation information, the output of the vehicle speed sensor 92 that detects the output rotation speed of the sub-transmission device 10 as the vehicle speed, and the correction data for the automatic straight-line driving control stored in the memory unit 60B. Then, based on the determined control target steering angle and the output of the steering angle sensor 70, the operation of the steering motor 84 is controlled so that the steering angles of the left and right front wheels 6A become the control target steering angles. In other words, in the control target area Rsa of the target straight-line route Rs, the traveling vehicle body 1 automatically travels on the target straight-line route Rs by the automatic straight-line control of the direction control unit 60M, so the driver does not need to steer the traveling vehicle body 1 so that it does not deviate from the target straight-line route Rs. As a result, the effort required by the driver during work travel can be reduced.

[0132] As the route setting unit 60L switches to a state in which the target route setting control is executed based on the operation of the second changeover switch 91, the direction control unit 60M switches to a functional state in which the automatic straight running control can be executed, and causes the second notification unit 47C consisting of an LED provided in the notification device 47 to blink. As the route setting unit 60L switches to a state in which the target route setting control is not executed based on the operation of the second changeover switch 91, the direction control unit 60M switches to a stopped state in which the automatic straight running control is not executed, and turns off the second notification unit 47C.

[0133] Incidentally, an electromagnetic pickup type or the like can be used for the vehicle speed sensor 92. For the correction data for the automatic straight-line control, map data or relational expressions showing the relationship between the amount and direction of deviation of the current position of the traveling vehicle body 1 from the target straight-line route Rs, the vehicle speed of the traveling vehicle body 1, and the control target steering angles of the left and right front wheels 6A, as well as map data or relational expressions showing the relationship between the angle and direction of deviation of the current heading of the traveling vehicle body 1 from the target straight-line route Rs, the vehicle speed of the traveling vehicle body 1, and the control target steering angles of the left and right front wheels 6A, and the like can be used.

[0134] As shown in Fig. 6 and Fig. 11, the control target area Rsa of the target straight path Rs where the direction control unit 60M executes the automatic straight-line control is an area obtained by excluding the manual driving area Rsb where the traveling vehicle body 1 has traveled from the travel start point Pa on the target straight-line path Rs until the execution condition of the automatic straight-line control is satisfied from the actual driving area Rsc from the travel start point Pa to the travel end point Pb on the target straight-line path Rs. The travel start point Pa is the point where the direction control unit 60M detects the transition of the traveling vehicle body 1 from a small turning state to a straight-line state based on the detection of the steering angle sensor 70. The travel end point Pb is the point where the direction control unit 60M detects the transition of the traveling vehicle body 1 from a straight-line state to a small turning state based on the detection of the steering angle sensor 70. The direction control unit 60M determines that the conditions for executing automatic straight-line control are met when it detects, based on the target straight-line route Rs set by the route setting unit 60L and the measurement results of the positioning unit 86, that the amount of deviation of the current position of the traveling vehicle body 1 from the target straight-line route Rs and the deviation angle of the current orientation of the traveling vehicle body 1 from the target straight-line route Rs have changed from outside the allowable range to within the allowable range.

[0135] Therefore, if, after making a berm turn, the position of the center mascot 93, which is located in the left and right central location of the front end of the vehicle body 1, is significantly misaligned with the driving reference line L formed by the marker 29, the driver must determine that the above-mentioned deviation amount and deviation angle are outside the acceptable range, and in order to establish the conditions for executing automatic straight-line control, the driver must perform manual correction steering by operating the steering wheel 41 to steer the left and right front wheels 6A so that the above-mentioned deviation amount and deviation angle are within the acceptable range; specifically, so that the driving reference line L extends straight in the line of sight when viewing the center mascot 93 from the seated position.

[0136] In order to facilitate such correction operation by the driver, in its functional state, when the direction control unit 60M detects that the traveling vehicle body 1 has reached the traveling start point Pa based on information from the operation control unit 60E or the work control unit 60G, it executes a judgment control to judge whether or not the execution condition for the automatic straight-line control is satisfied based on the target straight-line route Rs set by the route setting unit 60L and the measurement result of the positioning unit 86. If the execution condition is determined not to be satisfied in this judgment control, the second notification unit 47C is kept in a flashing state to notify the driver that the execution condition for the automatic straight-line control is not satisfied. If the execution condition is determined to be satisfied, the second notification unit 47C is switched from a flashing state to a lit state to notify the driver that the direction control unit 60M is in the execution state of the automatic straight-line control. As a result, when the second notification unit 47C switches from a flashing state to a lit state with the end of the edge-of-field turning, the driver can know that the automatic straight-line control has been executed with the end of the edge-of-field turning. Also, when the second notification unit 47C continues to flash even after the edge-of-field turning is finished, the driver can know that the above-mentioned deviation amount and deviation angle are outside the allowable range and the above-mentioned manual correction steering is necessary. Then, when the second notification unit 47C switches from a flashing state to a lit state by the manual correction steering, the driver can know that the above-mentioned deviation amount and deviation angle are within the allowable range and the automatic straight-line control has been executed.

[0137] Next, with reference to Figs. 6 and 8 to 11, an example of a case where seedling planting work is performed in a rectangular paddy field using the control operations of the work control unit 60G, the path setting unit 60L, the direction control unit 60M, etc. will be described.

[0138] (1) Before starting work travel, the driver performs a preparatory run to secure each work travel route R2a-R2d for roundabout planting at the edge of the field. In this preparatory run, when starting straight travel on each work travel route R2a, R2c for roundabout planting along each work travel route R1a-R1e for reciprocating planting, the driver operates the first work lever 45 or the second work lever 46 to lower the seedling planting device 4 to the working height position, and operates the second work lever 46 to switch the marker 29 on the reciprocating planting area side to the working position. This makes it possible to form a travel reference line L on the mud surface that can be used when traveling on the first work travel route R1a and the final work travel route R2e for reciprocating planting. (2) While driving straight on the detour planting work travel route R2a adjacent to the initial reciprocating planting work travel route R1a, the driver first operates the first switch 89 to register the teaching start position Pta by the route setting unit 60L, and after driving straight for a set distance from this registration, operates the second switch 90 to register the teaching end position Ptb by the route setting unit 60L. Then, the route setting unit 60L executes the teaching control described above, thereby obtaining the reference orientation Ro suitable for reciprocating planting in this paddy field. (3) While traveling straight on the work travel route R2a for planting around the work area, the driver operates the first changeover switch 78 to switch the work control unit 60G to the execution state described above. Also, the driver operates the second changeover switch 91 to switch the route setting unit 60L to the execution state of the target route setting control and to switch the direction control unit 60M to the function state. At this time, the direction control unit 60M is in a state in which the automatic straight travel control described above can be executed, so the second notification unit 47C flashes. (4) When the traveling vehicle body 1 reaches a direction change area at the edge of the field while traveling straight on the work traveling path R2a for round-trip planting, the driver performs a turn operation (180-degree direction change operation) at the edge of the field to move the traveling vehicle body 1 from the work traveling path R2a for round-trip planting to the first work traveling path R1a for adjacent round-trip planting. Then, the steering angle sensor 70 detects the transition of the traveling vehicle body 1 from the straight traveling state to the small turn state, and based on this detection, the work control unit 60G executes the second non-working state switching control described above to raise the seedling planting device 4 to the upper limit position and switch the marker 29 in the working position to the stored position. In addition, the path setting unit 60L executes the target path setting control to set the target straight path Rs along the above-mentioned reference direction Ro at a position on the turning direction side away from the work traveling path R2a for round-trip planting by a set distance (here, a distance corresponding to the work width W of the seedling planting device 4) in the perpendicular direction. (5) When the traveling body 1 approaches the travel start point Pa of the initial work travel route R1a (target straight route Rs) for reciprocating planting during this ridge-side turning operation, the driver ends the ridge-side turning operation so that the traveling body 1 travels straight on the initial work travel route R1a for reciprocating planting. Then, the steering angle sensor 70 detects the transition of the traveling body 1 from a small turning state to a straight state, and based on this detection, the work control unit 60G executes the second work state switching control described above. As a result, in conjunction with the traveling body 1 shifting from the ridge-edge turning state to the straight-line state, the seedling planting device 4 and the fertilizer applicator 5 switch from the non-working state to the working state described above, and the riding rice transplanter switches from the moving traveling state to the working traveling state. Also, based on the detection of the steering angle sensor 70 at this time, the direction control unit 60M detects that the traveling body 1 has reached the travel start point Pa, and executes the above-mentioned judgment control in response to this detection. (6) In this judgment control, if the direction control unit 60M determines that the conditions for executing the automatic straight-line control are not met, the second notification unit 47C will continue to flash as long as this judgment continues. Based on this, the driver performs the manual correction steering described above so that the traveling body 1 is positioned on the initial work traveling route R1a for round-trip planting (so that the aforementioned deviation amount and deviation angle fall within the allowable range). In addition, in this judgment control, when the direction control unit 60M judges that the execution condition of the automatic straight-line control is satisfied, the above-mentioned control target area Rsa is entered, so the direction control unit 60M starts the automatic straight-line control and the second notification unit 47C switches from a flashing state to a lit state. Then, based on the automatic straight-line control of the direction control unit 60M, the traveling body 1 automatically travels on the initial work travel route R1a (target straight-line route Rs) for reciprocating planting, and the driver does not need to steer the traveling body 1 so as not to deviate from the initial work travel route R1a for reciprocating planting. (7) When the traveling vehicle body 1 reaches a direction change area at the edge of the field during straight travel on the first work travel path R1a for this round-trip planting, the driver performs a turn at the edge of the field to move the traveling vehicle body 1 from the current work travel path R1a to the adjacent next work travel path R1b. Then, the steering angle sensor 70 detects the transition of the traveling vehicle body 1 from the straight travel state to the small turn state, and based on this detection, the work control unit 60G executes the second non-work state switching control described above. In addition, the path setting unit 60L executes the target path setting control to set the target straight path Rs along the reference direction Ro described above at a position on the turning direction side away from the current work travel path R1a in the perpendicular direction by a set distance. Furthermore, the direction control unit 60M detects that the traveling body 1 has reached the travel end point Pb on the current work travel route R1a, and ends the automatic straight-line control described above, and the second notification unit 47C switches from a lit state to a flashing state. As a result, in conjunction with the traveling body 1 moving from a straight-line state to a ridge-edge turning state, the seedling planting device 4 and the fertilizer application device 5 switch from the working state described above to the non-working state described above, and the riding rice transplanter switches from a work travel state to a mobile travel state. (8) When this ridge-edge turning operation brings the vehicle body 1 close to the starting point Pa of the next work driving route R1b, the driver will perform the operations (5) to (7) described above in that order on the subsequent round-trip driving routes as appropriate until the vehicle body 1 reaches the direction change area at the ridge edge while driving straight ahead on the final work driving route R1e for round-trip planting. In other words, in the control target area Rsa of the target straight-line path Rs on the round-trip driving route, automatic straight-line control is executed and the driving vehicle body 1 automatically drives on the target straight-line path Rs, and in the direction change area, the second non-working state switching control and the second working state switching control are appropriately executed in conjunction with the driver's edge turning operation, so that the seedling planting device 4 and the fertilizer application device 5 are switched between the non-working state and the working state at the appropriate timing. As a result, seedlings can be planted and fertilized well along the round-trip travel route while effectively reducing the effort required by the driver during work travel without reducing work efficiency. (9) After that, when the traveling body 1 reaches the direction change area at the ridge while traveling straight on the final work traveling route R1e for reciprocating planting, the driver operates the second changeover switch 91 to switch the path setting unit 60L to the non-execution state described above and to switch the direction control unit 60M to the stop state. Also, a ridge-edge turning operation is performed to move the traveling body 1 from the final work traveling route R1e for reciprocating planting to the adjacent work traveling route R2c for roundabout planting. Then, based on the detection of the steering angle sensor 70 at this time, the work control unit 60G executes the second non-work state switching control described above, and the riding rice transplanter switches from the work traveling state to the travel traveling state. Then, during this ridge-edge turning, the driver operates the first changeover switch 78 to switch the work control unit 60G to the non-execution state described above. Then, even if the driver ends the ridge-edge turning operation to make the traveling body 1 travel on the work traveling route R2c for roundabout planting, the riding rice transplanter will maintain the travel traveling state. This enables the driver to quickly move the riding rice transplanter from the final work travel route R1e for round trip planting toward the initial work travel route R2a for round trip planting. (10) Then, after moving to the initial work travel route R2a for peripheral planting, the driver manually drives the traveling vehicle body 1 along each of the work travel routes R2a to R2d for peripheral planting, while operating the first work lever 45 or the second work lever 46 to switch the seedling planting device 4 and the fertilizer application device 5 between the working state and the non-working state suitable for peripheral planting.

[0139] As shown in FIG. 6, the traveling vehicle body 1 is equipped with a first remaining amount detection unit 24A that detects the remaining amount of mat-shaped seedlings on the seedling carrier 24, a second remaining amount detection unit 31A that detects the remaining amount of fertilizer in the hopper 31, and a clogging sensor (one example of a malfunction sensor) 35A that detects fertilizer clogging inside each furrow former 35 as a malfunction related to the work. The first remaining amount detection unit 24A employs eight limit switches that detect when the remaining amount of the corresponding mat-shaped seedlings has decreased to a set value for seedling supply. The second remaining amount detection unit 31A employs a transmission type photoelectric sensor that detects when the remaining amount of fertilizer has decreased to a set value for fertilizer supply. The clogging sensor 35A has a pair of electrodes arranged at a predetermined interval in each furrow former, and detects fertilizer clogging by detecting the flow of electricity between the pair of electrodes when the fertilizer supplied by water adheres to the pair of electrodes.

[0140] The alarm device 47 is equipped with a third alarm unit 47D consisting of an LED for notifying the driver that the remaining amount of any of the mat-shaped seedlings placed on the seedling carrier 24 has fallen to the set amount for seedling replenishment, a fourth alarm unit 47E consisting of an LED for notifying the driver that the remaining amount of fertilizer stored in the hopper 31 has fallen to the set value for fertilizer replenishment, and a fifth alarm unit 47F consisting of an LED for notifying the driver that fertilizer clogging has occurred in any of the furrow formers 35.

[0141] When the work control unit 60G detects based on the output of the first remaining amount detection unit 24A that the remaining amount of any of the mat-shaped seedlings placed on the seedling carrier 24 has fallen to the set value for seedling supply, it switches the third notification unit 47D for seedling supply notification from an off state to a flashing state. This makes it possible to prompt the driver to supply mat-shaped seedlings to the seedling carrier 24. After that, when the third notification unit 47D is in a flashing state, when it detects based on the output of the first remaining amount detection unit 24A that the remaining amount of all of the mat-shaped seedlings placed on the seedling carrier 24 has exceeded the set value for seedling supply, it switches the third notification unit 47D from a flashing state to an off state.

[0142] When the work control unit 60G detects, based on the output of the second remaining amount detection unit 31A, that the remaining amount of fertilizer stored in the hopper 31 has fallen to the set value for fertilizer replenishment, the work control unit 60G switches the fourth notification unit 47E for notifying fertilizer replenishment from an off state to a flashing state. This makes it possible to urge the driver to replenish fertilizer to the hopper 31. Thereafter, while the fourth notification unit 47E is in the flashing state, when it detects, based on the output of the second remaining amount detection unit 31A, that the remaining amount of fertilizer stored in the hopper 31 has exceeded the set value for fertilizer replenishment, the work control unit 60G switches the fourth notification unit 47E from a flashing state to an off state.

[0143] When the work control unit 60G detects, based on the output of the clogging sensor 35A, that a fertilizer clogging has occurred in any of the furrow formers 35, it switches the fifth notification unit 47F for notifying clogging from an off state to a flashing state. This makes it possible to urge the driver to remove the fertilizer that has clogged the furrow formers 35. Thereafter, when the work control unit 60G detects, while the fifth notification unit 47F is in a flashing state, that the fertilizer clogging in each furrow former 35 has been cleared based on the output of the clogging sensor 35A, it switches the fifth notification unit 47F from a flashing state to an off state.

[0144] When the driver visually recognizes the flashing of the third alarm unit 47D, the fourth alarm unit 47E, or the fifth alarm unit 47F during work travel on each work travel route R1a to R1e, R2a to R2d, the driver will transition from a driving state in which he sits in the driver's seat 48 and operates the steering wheel 41, etc., to an auxiliary work state (an example of another work state) in which he leaves the driver's seat 48 and performs tasks such as supplying seedlings to the seedling carrier 24, supplying fertilizer to the hopper 31, or removing fertilizer that has become clogged in the furrow former 35.

[0145] Next, a case where the driver needs to shift from a driving state to an assisting work state during work travel on each of the work travel routes R1a to R1e and R2a to R2d will be described with reference to Figs.

[0146] (1) When the driver visually recognizes the blinking of the third notification unit 47D, the fourth notification unit 47E, or the fifth notification unit 47F, the driver first operates the main shift lever 42 to the work interruption position 58e while performing a traveling stop operation by operating the main shift lever 42 to the neutral position or depressing the brake pedal 44. Then, based on these operations, the traveling vehicle body 1 stops traveling, and the work control unit 60G executes the first non-working state switching control described above, and this first non-working state switching control switches the seedling planting device 4 and the fertilizer application device 5 from the working state to the non-working state. In addition, the condition determination unit 60K determines whether the temporary stop condition of the engine 7 is satisfied or not satisfied, and when it is determined that the condition is satisfied, the engine control unit 60H executes the engine temporary stop control described above, and this engine temporary stop control causes the engine 7 to be temporarily stopped and the first notification unit 47B to light up. In other words, if the driver needs to switch from a driving state to an auxiliary work state during work travel on each of the work travel routes R1a to R1e, R2a to R2d, he or she can switch the riding rice transplanter from a work travel state to a travel stop state and temporarily stop the engine 7 by simply operating the main shift lever 42 to the work interruption position 58e along with stopping travel. This allows the operator to quickly switch from the operating state to the auxiliary operation state, and to perform the auxiliary operation while preventing fuel from being wasted during the auxiliary operation. When the seedling planting device 4 is not in operation, the seedling planting device 4 rises to the upper limit position, bringing the seedling carrier 24 closer to the driving unit 40, making it easier for the operator to supply seedlings to the seedling carrier 24 from the driving unit 40. (2) When the driver finishes the auxiliary work such as seedling supply or fertilizer supply, he operates the main shift lever 42 from the work interruption position 58e to the neutral position while depressing the brake pedal 44 to the braking position. Then, based on this operation, the work control unit 60G executes the first work state switching control described above, and this first work state switching control switches the seedling planting device 4 and the fertilizer application device 5 from the non-working state to the same working state as before the auxiliary work started. Also, when the engine 7 is temporarily stopped, the engine control unit 60H executes the engine restart control described above, and this engine restart control restarts the engine 7 and turns off the first notification unit 47B. After that, when the driver returns the brake pedal 44 to the brake release position and operates the main shift lever 42 from the neutral position to the forward shift path 58b, the traveling vehicle body 1 starts traveling forward, and the seedling planting device 4 and the fertilizer application device 5 are driven. In other words, when the driver has finished supplying seedlings or fertilizer and wishes to resume work driving on the work driving routes R1a-R1e, R2a-R2d, he or she can switch the riding rice transplanter from a stopped state to a work driving state simply by depressing the brake pedal 44 into the braking position and operating the main shift lever 42 from the work interruption position 58e to the neutral position, and then returning the brake pedal 44 to the brake release position and operating the main shift lever 42 from the neutral position to the forward shift route 58b.

[0147] The direction control unit 60M interrupts the automatic straight-line driving control when engine temporary stop control is executed while the automatic straight-line driving control described above is being executed, and resumes the automatic straight-line driving control when engine restart control is executed while the automatic straight-line driving control is interrupted. As a result, when the need arises to perform auxiliary work during work driving on the work driving routes R1a to R1e for reciprocating planting using the automatic straight-line control of the directional control unit 60M, the driver operates the main shift lever 42 to the work interruption position 58e and the engine control unit 60H executes engine temporary stop control based on this operation, in conjunction with this, the directional control unit 60M interrupts the automatic straight-line control, thereby preventing unnecessary power consumption due to the continuation of the automatic straight-line control even in a travel-stopped state where the engine 7 is temporarily stopped to perform auxiliary work. Thereafter, when the driver finishes the auxiliary work and operates the main shift lever 42 from the work interruption position 58e to the neutral position, the engine control unit 60H executes engine restart control based on this operation, and in conjunction with this, the direction control unit 60M resumes the automatic straight-line control, so that even after work driving is resumed, the traveling vehicle body 1 can be made to automatically travel on the target straight-line route Rs based on the automatic straight-line control of the direction control unit 60M.

[0148] As shown in Figures 6 and 8 to 11, the ECU 60 is equipped with a point memory unit 60N that stores a turning start point P at which the traveling vehicle body 1 transitions from a straight-ahead state to a field edge turning state (a 180-degree direction change state), and a reach determination unit 60P that determines whether the traveling vehicle body 1 has reached the turning start point P.

[0149] When the steering angle sensor 70 detects the transition of the traveling body 1 from a straight-line state to a left small turn state or a right small turn state based on the output of the steering angle sensor 70 and the positioning result of the positioning unit 86, the point memory unit 60N stores the transition start point of the traveling body 1 from a straight-line state to a left small turn state or a right small turn state obtained from the positioning result of the positioning unit 86 as a left turn start point Pc or a right turn start point Pd. The arrival determination unit 60P sets the turn start points Pc, Pd on the current work travel route R1a-R1e for reciprocating planting based on the left turn start point Pc or the right turn start point Pd stored in the point memory unit 60N, and executes setting determination control to determine whether the traveling body 1 has reached the turn start points Pc, Pd on the current work travel route R1a-R1e for reciprocating planting based on the set turn start points Pc, Pd and the positioning result of the positioning unit 86.

[0150] When the arrival determination unit 60P determines that the traveling body 1 has reached the left turn start point Pc or the right turn start point Pd, the direction control unit 60M executes automatic direction change control to automatically change direction (make a ridge-edge turn) from the current work traveling route R1a-R1d (target straight route Rs) in a round trip to the next work traveling route R1b-R1e (target straight route Rs).

[0151] The control operation of the direction control section 60M during automatic direction change control will now be described. When the direction control unit 60M detects that the running vehicle body 1 has reached the left turn start point Pc based on the judgment result of the arrival judgment unit 60P, it performs a left direction turn process to control the operation of the steering motor 84 so that the running vehicle body 1 is in a small left turn state, and starts timing by the timing unit 60C. Thereafter, when a predetermined time has elapsed from the start of the left turn processing until the vehicle body 1 completes a turn around the edge of a field (a 180 degree turn), a straight-line return processing is performed in which the operation of the steering motor 84 is controlled so that the vehicle body 1 returns to a straight-line state as that time elapses. Conversely, when it is detected that the traveling vehicle body 1 has reached the right turn start point Pd based on the judgment result of the arrival judgment unit 60P, a right direction turn process is performed to control the operation of the steering motor 84 so that the traveling vehicle body 1 is in a small right turn state, and timing is started by the timing unit 60C. Thereafter, when a predetermined time required for the traveling vehicle body 1 to complete turning around the edge of a field elapses from the start of the right turn processing, the above-mentioned straight-line return processing is performed as that time elapses. In other words, in the direction change area at the edge of the field, the automatic direction change control of the direction control unit 60M makes it possible to automatically turn the traveling vehicle body 1 around the edge of the field, thereby further reducing the effort required by the driver when planting seedlings by planting in a back and forth motion.

[0152] The direction control unit 60M switches between an execution state in which automatic direction change control is executed and a non-execution state in which automatic direction change control is not executed, based on the operation of a manual third changeover switch 94 provided in the driving unit 40. The reach determination unit 60P switches to an execution state in which setting determination control is executed as the direction control unit 60M switches to an execution state in which automatic direction change control is executed based on the operation of the third changeover switch 94. Also, the reach determination unit 60P switches to a non-execution state in which setting determination control is not executed as the direction control unit 60M switches to a non-execution state in which automatic direction change control is not executed based on the operation of the third changeover switch 94. A toggle switch, a push button switch, or the like can be used as the third changeover switch 94.

[0153] When the direction control unit 60M is switched to an execution state in which automatic direction change control is performed when the left turn start point Pc and the right turn start point Pd of the traveling vehicle body 1 are not stored in the point memory unit 60N, the direction control unit 60M intermittently operates the sixth notification unit 47G, consisting of a buzzer provided in the notification device 47, to notify the driver that the left turn start point P and the right turn start point P are not stored in the point memory unit 60N.

[0154] Next, an example of planting seedlings in a rectangular rice paddy will be described using the control operations of the work control unit 60G, route setting unit 60L, direction control unit 60M, location memory unit 60N, and arrival determination unit 60P. Note that, here, the explanation will start from the stage where the above-mentioned teaching control has been completed, and the work control unit 60G has been switched to the above-mentioned execution state, the path setting unit 60L has been switched to the above-mentioned execution state, the direction control unit 60M has been switched to the above-mentioned functional state and execution state, and the reach determination unit 60P has been switched to the above-mentioned execution state, etc. have been completed.

[0155] (1) In straight-line travel on the work travel path R2a for roundabout planting adjacent to the initial work travel path R1a for roundabout planting, the left turn start point Pc and the right turn start point Pd of the traveling body 1 are not stored in the point memory unit 60N, so the sixth notification unit 47G operates intermittently to inform the driver that the left turn start point Pc and the right turn start point Pd are not stored in the point memory unit 60N. As a result, when the traveling body 1 reaches a direction change area at the edge of the field during straight-line travel on the work travel path R2a for roundabout planting, the driver performs a leftward ridge-edge turning operation to move the traveling body 1 from the work travel path R2a for roundabout planting to the initial work travel path R1a for roundabout planting adjacent to the left side. Then, the steering angle sensor 70 detects the transition of the traveling body 1 from a straight state to a left small turn state, and based on this detection, the work control unit 60G executes the second non-working state switching control described above to raise the seedling planting device 4 to the upper limit position and switch the marker 29 in the working position to the storage position. In addition, the path setting unit 60L executes the target path setting control to set the target straight path Rs along the above-mentioned reference direction Ro at a position on the turning direction side away from the work traveling path R2a for round planting in the perpendicular direction by a set distance. Then, the point memory unit 60N stores the travel end point Pb of the straight travel on the work traveling path R2a for round planting as the left turn start point Pc. (2) When the traveling body 1 approaches the travel start point Pa of the first work travel route R1a for reciprocating planting by this left ridge turning operation, the driver ends the left ridge turning operation so that the traveling body 1 travels straight on the first work travel route R1a for reciprocating planting. Then, the steering angle sensor 70 detects the transition of the traveling body 1 from the left small turn state to the straight state, and based on this detection, the work control unit 60G executes the second work state switching control described above to switch the riding rice transplanter from the travel travel state to the work travel state. Also, based on the detection of the steering angle sensor 70 at this time, the direction control unit 60M detects the arrival of the traveling body 1 at the travel start point Pa and executes the judgment control described above. (3) In this judgment control, if the direction control unit 60M determines that the conditions for executing the automatic straight-line control are not satisfied, the second notification unit 47C will continue to flash as long as this judgment continues. Based on this, the driver performs the manual correction steering described above so that the traveling body 1 is positioned on the initial work traveling route R1a for round-trip planting. In addition, in this judgment control, when the direction control unit 60M judges that the execution condition of the automatic straight-line control is satisfied, the above-mentioned control target area Rsa is entered, so the direction control unit 60M starts the automatic straight-line control and the second notification unit 47C switches from a flashing state to a lit state. Then, based on the automatic straight-line control of the direction control unit 60M, the traveling body 1 automatically travels on the initial work travel route R1a for reciprocating planting, and the driver does not need to steer the traveling body 1 so as not to deviate from the initial work travel route R1a for reciprocating planting. However, in the automatic straight-line control at this time, since the right turn start point Pd is not stored in the point memory unit 60N, the sixth notification unit 47G continues to operate intermittently to inform the driver that the right turn start point Pd is not stored in the point memory unit 60N. (4) When the traveling body 1 reaches a direction change area at the edge of the field during straight travel on the first work travel path R1a for this round-trip planting, the driver performs a right edge of the field turn operation to move the traveling body 1 from the current work travel path R1a to the next work travel path R1b adjacent to the right side based on the intermittent operation of the sixth notification unit 47G. Then, the steering angle sensor 70 detects the transition of the traveling body 1 from the straight travel state to the right small turn state, and based on this detection, the work control unit 60G executes the second non-work state switching control described above to switch the riding rice transplanter from the work travel state to the travel travel state. In addition, the path setting unit 60L executes the target path setting control to set the target straight path Rs along the reference direction Ro described above at a position on the turning direction side away from the current work travel path R1a by a set distance in the perpendicular direction. Furthermore, the direction control unit 60M detects that the traveling body 1 has reached the travel end point Pb on the current work traveling route R1a, and ends the automatic straight traveling control described above, and the second notification unit 47C switches from a lit state to a flashing state. Then, the point memory unit 60N stores the travel end point Pb of the straight traveling on the current work traveling route R1a as the right turn start point Pd, and the sixth notification unit 47G stops intermittent operation. (5) When the traveling body 1 approaches the travel start point Pa of the next work travel route R1b by this right ridge turning operation, the driver ends the right ridge turning operation so that the traveling body 1 travels straight on the work travel route R1b. Then, the steering angle sensor 70 detects the transition of the traveling body 1 from the right small turn state to the straight traveling state, and based on this detection, the work control unit 60G executes the second work state switching control described above to switch the riding rice transplanter from the moving traveling state to the work traveling state. Also, based on the detection of the steering angle sensor 70 at this time, the direction control unit 60M detects the arrival of the traveling body 1 at the travel start point Pa and executes the above-mentioned judgment control, and based on this judgment control, etc., manual correction steering by the driver or automatic straight traveling control by the direction control unit 60M is performed as described in the above (3). (6) In the subsequent automatic straight-line control, since the left turn start point Pc on the work travel route R2a for round-trip planting and the right turn start point Pd on the work travel route R1a for round-trip planting are stored in the point memory unit 60N, the arrival determination unit 60P executes the above-mentioned setting determination control on the subsequent work travel routes R1b to R1e based on these turn start points Pc and Pd. Also, the direction control unit 60M ends the above-mentioned automatic straight-line control and executes the above-mentioned automatic direction change control each time the arrival determination unit 60P determines that the traveling body 1 has reached each turn start point Pc or Pd. Then, each time the automatic direction change control is executed, the steering angle sensor 70 detects the transition of the traveling body 1 from a straight state to a small turning state, and based on this detection, the work control unit 60G executes the second non-work state switching control described above to switch the riding rice transplanter from the work traveling state to the moving traveling state, the path setting unit 60L executes the target path setting control to set the next target straight traveling path Rs, and the second notification unit 47C switches from the lit state to the blinking state. Then, when the predetermined time for the ridge-side turning described above has elapsed, the direction control unit 60M ends the ridge-side turning operation by the automatic direction change control so that the traveling body 1 is in a straight state. Then, the steering angle sensor 70 detects the transition of the traveling body 1 from the small turning state to the straight state, and based on this detection, the work control unit 60G executes the second work state switching control described above to switch the riding rice transplanter from the moving traveling state to the working traveling state. Also, based on the detection of the steering angle sensor 70 at this time, the direction control unit 60M detects that the traveling vehicle body 1 has reached the traveling start point Pa and executes the aforementioned judgment control, and based on this judgment control, manual correction steering by the driver or automatic straight-line control by the direction control unit 60M is performed, as described above in (3). In other words, when performing seedling planting work by back and forth planting in a rectangular rice paddy, by using the control operations of the work control unit 60G, route setting unit 60L, direction control unit 60M, point memory unit 60N, and arrival judgment unit 60P, if the left turn start point Pc and the right turn start point Pd are stored in the point memory unit 60N, the driver will not need to operate the riding rice transplanter, except for the period when the execution conditions for the automatic straight-line control described above are not met after turning around the edge of the paddy field by automatic direction change control, and when it becomes necessary to perform auxiliary work such as supplying seedlings or fertilizer. As a result, the effort required by the driver during work driving can be significantly reduced. (7) After that, when straight travel is performed by the automatic straight travel control on the final work travel route R1e for reciprocating planting, the driver operates the third changeover switch 94 to switch the direction control unit 60M and the arrival determination unit 60P to the non-execution state described above. Then, when the traveling vehicle body 1 reaches the direction change area at the ridge, the driver operates the second changeover switch 91 to switch the route setting unit 60L to the non-execution state described above, and switches the direction control unit 60M to the stopped state described above. Also, a ridge-edge turning operation is performed to move the traveling vehicle body 1 from the final work travel route R1e for reciprocating planting to the adjacent work travel route R2c for roundabout planting. Then, based on the detection of the steering angle sensor 70 at this time, the work control unit 60G executes the second non-work state switching control described above to switch the riding rice transplanter from the work travel state to the travel travel state. Then, the driver operates the first changeover switch 78 to switch the work control unit 60G to the non-execution state described above during the ridge-edge turning at this time. Then, even if the driver subsequently ends the edge-of-field turning operation in order to cause the traveling body 1 to travel on the work traveling route R2c for round-planting, the riding rice transplanter will maintain the traveling state. This enables the driver to quickly move the riding rice transplanter from the final work travel route R1e for round trip planting toward the initial work travel route R2a for round trip planting. (8) Then, after moving to the initial work travel route R2a for peripheral planting, the driver manually drives the traveling vehicle body 1 along each of the work travel routes R2a to R2d for peripheral planting, while operating the first work lever 45 or the second work lever 46 to switch the seedling planting device 4 and the fertilizer application device 5 between the working state and the non-working state suitable for peripheral planting.

[0156] 1 and 6, the traveling vehicle body 1 is equipped with a spare remaining amount sensor 59D that detects a decrease in the remaining amount of seedlings in the spare storage section 59. The spare remaining amount sensor 59D can be a load sensor that detects the weight of seedlings at the spare remaining amount sensor 59D, or a limit switch that detects the presence or absence of mat-shaped seedlings on each spare seedling table 59B, or the like. When the direction control unit 60M detects a decrease in the remaining amount of seedlings in the reserve storage unit 59 based on detection by the reserve remaining amount sensor 59D while the automatic direction change control is being executed, and detects that the remaining amount of any of the mat-shaped seedlings placed on the seedling loading platform 24 has decreased to a set value for seedling replenishment based on the output of the first remaining amount detection unit 24A, it switches the third notification unit 47D for seedling replenishment notification from an off state to a flashing state, switches the automatic direction change control from an execution state to a stopped state, and continuously operates the sixth notification unit 47G to notify the driver that the automatic direction change control is not being executed. This allows the driver to recognize the need to replenish seedlings to the seedling carrier 24 as well as to the reserve storage section 59. When the traveling body 1 reaches a direction change area at the edge of a paddy field, the driver can stop the traveling body 1 with the front end of the traveling body 1 approaching the paddy field by operating the main shift lever 42 to the neutral position or depressing the brake pedal 44 to stop the traveling body 1. As a result, seedlings can be replenished quickly from the ridges to the seedling carrier 24 and the spare storage section 59 by using the boarding and alighting steps 95 provided on both the left and right ends of the front end of the vehicle body.

[0157] 6, the ECU 60 includes a vehicle speed control unit 60Q that controls the vehicle speed, and a transition estimation unit 60R that estimates a transition from the driver's driving state to another work state other than driving. When the transition estimation unit 60R estimates the driver's transition to another work state, the vehicle speed control unit 60Q executes deceleration control to reduce the vehicle speed to a set vehicle speed, causing the traveling vehicle body 1 to travel at a slow speed. The transition estimation unit 60R estimates the driver's transition to a seedling supply state (an example of another work state) when the detection value of the first remaining amount detection unit 24A drops to a set amount for seedling supply. The transition estimation unit 60R estimates the driver's transition to a fertilizer supply state (an example of another work state) when the detection value of the second remaining amount detection unit 31A drops to a set value for fertilizer supply. The transition estimation unit 60R estimates the driver's transition to a clog removal state (an example of another work state) when the clog sensor 35A detects a fertilizer clog in the furrow former. This allows the vehicle speed to be reduced by deceleration control of the vehicle speed control unit 60Q from the stage at which the transition estimation unit 60R estimates a transition from the driver's driving state to a seedling supply state, a fertilizer supply state, or a clog removal state based on detection by the first remaining amount detection unit 24A, the second remaining amount detection unit 31A, or the clog sensor 35A. As a result, when the driver stops the traveling vehicle body 1 before transitioning from the driving state to the seedling supply state, fertilizer supply state, or clog removal state, the time required for the traveling vehicle body 1 to stop traveling can be shortened, and therefore the driver can efficiently transition from the driving state to the seedling supply state, fertilizer supply state, or clog removal state.

[0158] The driver's seat 48 is equipped with a first seat sensor 48A that detects a change in the load applied to the driver's seat 48, and a second seat sensor 48B that detects a rotational movement of the driver's seat 48 from a reference position. The transition estimation unit 60R detects a decrease in load based on detection by the first seat sensor 48A and estimates the driver's transition from a driving state to another working state when it detects a rotational movement of the driver's seat 48 from a reference position based on detection by the second seat sensor 48B. As a result, when the driver attempts to leave the driver's seat 48 without stopping the traveling vehicle body 1 in order to perform work other than seedling supply work, fertilizer supply work, and clog removal work, the movement at that time is detected by the first seat sensor 48A and the second seat sensor 48B. Then, based on the detection of the first seat sensor 48A and the second seat sensor 48B, the transition estimation unit 60R can estimate the transition from the driver's driving state to a work state other than the seedling supply state, fertilizer supply state, and clog removal state, and the vehicle speed control unit 60Q based on this estimation performs deceleration control to reduce the vehicle speed to the set vehicle speed, and the traveling vehicle body 1 travels at a slow speed. This reduction in vehicle speed can make the driver realize that he or she has forgotten to stop the traveling vehicle body 1, and can urge the driver to perform the operation to stop the traveling vehicle body 1. In addition, the time required for the traveling vehicle body 1 to stop traveling after the driver performs the operation to stop the traveling vehicle body 1 can be shortened. In addition, when the transition estimation unit 60R detects a decrease in load based on the detection of the first seat sensor 48A and detects a rotating movement of the driver's seat 48 from the reference position based on the detection of the second seat sensor 48B, it estimates the driver's transition from a driving state to another working state, thereby avoiding a decrease in work efficiency caused by the vehicle speed control unit 60Q executing deceleration control based on a decrease in load due to the driver reclining in the driver's seat 48, or a rotating movement of the driver's seat 48 while the driver is seated.

[0159] The transition estimation unit 60R is switched between an operating state and a stopped state based on the operation of a manual fourth changeover switch 96 provided in the driving unit 40. As a result, for example, when the driver determines that there is no need to perform other tasks such as seedling supply work and fertilizer supply work near the end of a work drive, the transition estimation unit 60R can be switched to a stopped state to avoid a decrease in vehicle speed due to deceleration control by the vehicle speed control unit 60Q. As a result, when there is no need to perform other work, it is possible to avoid a decrease in work efficiency caused by a decrease in vehicle speed due to the deceleration control of vehicle speed control section 60Q.

[0160] The ECU 60 includes a transition detection unit 60S that detects the transition from the driver's driving state to the seedling supply state when the reserve remaining amount sensor 59D detects a decrease in the remaining amount. When the transition detection unit 60S detects the driver's transition to the seedling supply state while detecting the traveling of the traveling vehicle body 1 based on the output of the vehicle speed sensor 92, the vehicle speed control unit 60Q executes the above-mentioned deceleration control to reduce the vehicle speed to zero. This makes it possible to prevent the driver from carrying out seedling supply work while the traveling state of the traveling body 1 is maintained.

[0161] The transition detection unit 60S is switched between an operating state and a stopped state based on the operation of a manual fifth changeover switch 97 provided in the driving unit 40. This makes it possible to switch between a state in which automatic stopping of the traveling vehicle body 1 by deceleration control of the vehicle speed control unit 60Q based on detection by the transition detection unit 60S is adopted and a state in which it is not adopted.

[0162] When the vehicle speed control unit 60Q executes the deceleration control, it blinks the seventh notification unit 47H consisting of an LED provided in the notification device 47 to notify the driver that the vehicle speed will decrease due to the execution of the deceleration control. This makes it possible to avoid the driver feeling uncomfortable when the vehicle speed is reduced by the deceleration control of vehicle speed control section 60Q.

[0163] 6 and 7, the ECU 60 includes an energization control unit 60T that controls energization from the battery 37 to the satellite navigation system 87 and the inertial measurement system 88, bypassing the main switch 61. The traveling vehicle body 1 includes a first hold relay 98A that is provided in a power transmission path from the battery 37 to the satellite navigation system 87, and a second hold relay 98B that is provided in a power transmission path from the battery 37 to the inertial measurement system 88. The energization control unit 60T, the first hold relay 98A, and the second hold relay 98B constitute an energization hold unit 98 that enables energization from the battery 37 to the satellite navigation system 87 and the inertial measurement system 88, bypassing the main switch 61.

[0164] The power holding unit 98 switches to a first power holding state in which power is passed from the battery 37 to the satellite navigation device 87 when the power control unit 60T energizes the first hold relay 98A and switches the first hold relay 98A to a closed state, and switches to a first power stop state in which power is stopped from passing from the battery 37 to the satellite navigation device 87 when the power control unit 60T stops powering the first hold relay 98A and switches the first hold relay 98A to an open state.

[0165] The energization holding unit 98 switches to a second energization holding state in which energization is conducted from the battery 37 to the inertial measurement unit 88 when the energization control unit 60T energizes the second hold relay 98B and switches the second hold relay 98B to a closed state, and switches to a second energization stop state in which energization is stopped from the battery 37 to the inertial measurement unit 88 when the energization control unit 60T stops energizing the second hold relay 98B and switches the second hold relay 98B to an open state.

[0166] The energization holding unit 98 switches between the first energization holding state and the second energization holding state in conjunction with the shutoff operation of the main switch 61. In addition, the timer unit 60C starts timing in conjunction with the shutoff operation. If the main switch 61 is connected between the first energization holding state and the second energization holding state and the set time has elapsed, the energization holding unit 98 switches from the first energization holding state and the second energization holding state to the first de-energized state and the second de-energized state in conjunction with the connect operation, and if the main switch 61 is not connected between the set time and the set time has elapsed, the energization holding unit 98 switches from the first energization holding state and the second energization holding state to the first de-energized state and the second de-energized state as the set time has elapsed. The set time for energization holding can be arbitrarily set by operating a time setter 99 provided in the driving unit 40. A momentary switch or the like can be used as the time setter 99.

[0167] According to this configuration, for example, if the set time is set in the time setter 99 to a time longer than the longest time expected for an interruption in work driving (for example, the break time required for lunch), even if the driver turns off the main switch 61 to stop the engine 7 in order to prevent unnecessary fuel consumption during an interruption in work driving due to a break, it is possible to prevent power from being stopped due to the main switch 61 being turned off to the satellite navigation device 87, which requires a long start-up time from the start of power supply until positioning using a satellite is possible, and the inertial measurement unit 88, which is equipped with a gyroscope and the like and whose measurement accuracy is not stable unless the vehicle is warmed up. As a result, when the driver finishes a break or the like and operates the main switch 61 to start the engine 7, work driving using the automatic straight-line control can be resumed at the same time as the engine 7 starts. Furthermore, for example, if the set time is set to the shortest time (for example, 0 minute or 1 minute) using the time setter 99, when the driver turns off the main switch 61 upon completion of the work, power to the satellite navigation unit 87 and the inertial measurement unit 88 will be stopped at the same time as the main switch 61 is turned off, or, as the shortest set time has elapsed since the main switch 61 was turned off, the power holding unit 98 will automatically switch from the first power holding state and the second power holding state to the first power stop state and the second power stop state, and power to the satellite navigation unit 87 and the inertial measurement unit 88 will be stopped, thereby preventing power from being unnecessarily continued to be supplied to the satellite navigation unit 87 and the inertial measurement unit 88 even after the work has been completed. As a result, it is possible to prevent unnecessary fuel consumption during breaks and the like without causing a decrease in work efficiency, and it is also possible to prevent unnecessary power consumption after work is completed.

[0168] The energization holding unit 98 includes a third hold relay 98C that is interposed in a power transmission path extending from the battery 37 to the alarm device 47. The energization control unit 60T energizes the third hold relay 98C to switch the third hold relay 98C to a closed state, thereby switching to a third energization held state in which energization is conducted from the battery 37 to the alarm device 47, and the energization control unit 60T stops energization to the third hold relay 98C to switch the third hold relay 98C to an open state, thereby switching to a third energization stop state in which energization from the battery 37 to the alarm device 47 is stopped. When the notification device 47 is operating in the third power holding state by the power holding unit 98, the notification device 47 notifies the driver by displaying on the liquid crystal display unit 47A information regarding the power holding state, such as that the satellite navigation system 87 and the inertial measurement unit 88 are in the power holding state by the power holding unit 98, and the remaining time until the power holding unit 98 switches from the power holding state to the power stop state. This allows the driver to easily check whether the power holding unit 98 is in the power holding state, and the time remaining until the power holding unit 98 switches to the power stop state.

[0169] The satellite navigation system 87 and the inertial measurement system 88 are provided with operation lamps 87B, 88A made of LEDs that light up when they are in operation to indicate that they are in operation. The energization control unit 60T has, as the aforementioned set times, a first set time for maintaining energization to the satellite navigation system 87 and the inertial measurement system 88, and a second set time for maintaining energization to the notification device 47. The first set time is set to a time longer than the second set time. In other words, from the standpoint of work efficiency, the first set time, which is the power holding time for the satellite navigation system 87 and the inertial measurement system 88, which are more important to maintain power than the alarm system 47, is set to be longer than the second set time, which is the power holding time for the alarm system 47. This makes it possible to reduce consumption of battery 37 during breaks, etc., without reducing work efficiency, compared to when the power-on retention time of the satellite navigation system 87 and the inertial measurement system 88, for which maintaining power is highly important, is the same as the power-on retention time of the alarm device 47, for which maintaining power is less important.

[0170] When the main switch 61 is turned off to cut off the power supply from the battery 37, the ECU 60 maintains the power supply state by the internal self-holding circuit 60A and starts timekeeping by the timer 60C as described above. Also, by the control operation of the power supply holding unit 98, the ECU 60 maintains the power supply state to the satellite navigation system 87 and the inertial measurement system 88 as well as the power supply state to the notification device 47. Thereafter, if the second set time has elapsed without the main switch 61 being connected, the power supply to the notification device 47 is stopped, if the first set time has elapsed, the power supply to the satellite navigation system 87 and the inertial measurement system 88 is stopped, and if the set time for maintaining the power supply state by the self-holding circuit 60A has elapsed, the power supply by the self-holding circuit 60A is stopped to stop operation. In other words, the set time for which the ECU 60, for which it is most important to maintain the power supply state, is maintained in the power supply state by the self-holding circuit 60A is set to a time longer than the first set time and the second set time.

[0171] [Another embodiment] The present invention is not limited to the configurations exemplified in the above-described embodiments, and other representative embodiments of the present invention will be described below.

[0172] [1] The work vehicle may be configured as a semi-crawler vehicle having left and right crawlers instead of the left and right rear wheels 6B. Furthermore, the work vehicle may be configured as a full crawler vehicle equipped with left and right crawlers instead of the left and right front wheels 6A and the left and right rear wheels 6B.

[0173] [2] The work vehicle may be equipped with left and right side clutch brakes instead of the left and right side clutches 17, and may be configured for brake turning specifications in which a brake turning state in which the side clutch brake on the inside of the turn is activated is realized as a direction change state (small turning state) of the traveling body 1. In addition, the work vehicle may be equipped with a front wheel speed increasing device instead of the left and right side clutches 17, and may be configured for front wheel speed increasing turning specifications in which a front wheel speed increasing turning state in which the speed of the front wheel 6A on the outside of the turn is increased is realized as a direction change state (small turning state) of the traveling body 1. The work vehicle may also be a type that performs a switch turn using reverse travel to change direction.

[0174] [3] The work vehicle may be configured to include a rolling control unit that controls the roll angle of the ground work implement A.

[0175] [4] The work vehicle may be configured so that the work control unit 60G does not perform non-working state switching control and working state switching control.

[0176] [5] The work vehicle may be configured so that the engine temporary stop control and the engine restart control are not performed by the engine control unit 60H.

[0177] [6] The ground work implement A may be a direct seeding implement, a rotary tilling implement, a plow, a tilling implement, a harvesting implement, a grass cutting implement, a bucket, or the like.

[0178] [7] The route setting unit 60L may be configured to set the target straight route Rs based on work site data in which each work travel route R2a to R2d for circular planting and each work travel route R1a to R1e for round trip planting are set for each work site, for example, based on prior measurement or the previous work travel.

[0179] [8] The condition determination unit 60K may be configured to determine whether the condition for temporarily stopping the engine 7 is met when the interruption switch 58B detects that the main shift lever 42 has moved to the work interruption position 58e. In addition, the condition determination unit 60K may be configured to determine whether a temporary suspension condition for the engine 7 is met when a special operation of an existing switch, such as a long press of the first switch 89 or the second switch 90 for teaching, or a double press of the first switch 89 or the second switch 90, is detected. In addition, the condition determination unit 60K may be configured to detect a special operation of an existing switch and then determine whether a temporary suspension condition for the engine 7 is met when conditions suitable for restarting the engine 7 are met, such as, for example, the output speed of the engine 7 being equal to or lower than a set speed (e.g., idling speed), the voltage of the battery 37 being equal to or higher than a set value, and the temperature of the engine coolant being equal to or higher than a set value (e.g., 55 degrees).

[0180] [9] The point storage unit 60N may store, for example, each turning start point Pc, Pd for each work site obtained by a prior measurement or during a previous work drive.

[0181]

[10] The point memory unit 60N stores a turning start point Pc, Pd at which the running vehicle body 1 transitions from a straight-ahead state to a direction change state, and a turning end point at which the running vehicle body 1 transitions from a direction change state to a straight-ahead state, the reach determination unit 60P determines whether the running vehicle body 1 has reached the turning start point Pc, Pd, and also determines whether the running vehicle body 1 has reached the turning end point, and the direction control unit 60M may be configured to start automatic direction change control when the reach determination unit 60P determines that the running vehicle body 1 has reached the turning start point Pc, Pd, and to end the automatic direction change control when the reach determination unit 60P determines that the running vehicle body 1 has reached the turning end point.

[0182]

[11] After completion of a ridge-edge turn, the center mascot 93 may be equipped with a second notification unit 47C that notifies the driver whether the amount of deviation of the current position of the traveling vehicle body 1 from the target straight-line route Rs and the deviation angle of the current orientation of the traveling vehicle body 1 from the target straight-line route Rs are outside or within the acceptable range.

[0183]

[12] The positioning unit 86 may be equipped with a satellite navigation device 87 such as a DGPS (Differential GPS) or an RTK-GPS (Real Time Kinematic GPS).

[0184]

[13] Instead of the satellite navigation device 87, the positioning unit 86 may be equipped with, for example, an optical measuring device that measures the position of the vehicle body using laser light.

[0185]

[14] The remaining amount detection units 24A and 31A may be configured to detect the remaining amount in the storage units 24 and 31 by calculation processing based on the positioning results of the positioning unit 86. Specifically, the remaining amount detection unit 24A, 31A detects the remaining amount in the storage unit 24, 31 by calculation based on, for example, the amount of supply stored in the storage unit 24, 31, the amount of supply per unit distance, and the distance traveled at the work site obtained as the positioning result of the positioning unit 86. That is, the remaining amount in the storage units 24 and 31 can be detected without providing a dedicated sensor for detecting the remaining amount of the supply material as the remaining amount detection units 24A and 31A.

[0186]

[15] The transition detection unit 70 may be a rotational sensor that detects the amount of rotation of the steering wheel 41 as the steering angle of the front wheels 6A, or a rotary potentiometer or rotary encoder that directly detects the steering angle of one of the left and right front wheels 6A.

[0187]

[16] The transition estimation unit 60R may be configured to estimate a transition of the driver to another working state when a reduction in load is detected based on detection by the first seat sensor 48A.

[0188]

[17] The transition estimation unit 60R may be configured to estimate the driver's transition to another working state when a rotational movement of the driver's seat 48 from a reference position is detected based on detection by the second seat sensor 48B.

[0189]

[18] The transition detection unit 60S may be configured to detect a transition of the driver from a driving state to another working state when it detects a reduction in load based on detection by the first seat sensor 48A and detects a turning movement of the driver's seat 48 from the reference position based on detection by the second seat sensor 48B, and the vehicle speed control unit 60Q may be configured to execute the above-mentioned deceleration control to reduce the vehicle speed to zero when the transition detection unit 60S detects a transition of the driver from a driving state to another working state while detecting the traveling of the traveling vehicle body 1 based on the output of the vehicle speed sensor 92.

[0190]

[19] The transition detection unit 60S may be configured to detect the transition of the driver from a driving state to another working state when a reduction in load is detected based on detection by the first seat sensor 48A. In addition, the transition detection unit 60S may be configured to detect the driver's transition from a driving state to another working state when a rotational movement of the driver's seat 48 from a reference position is detected based on detection by the second seat sensor 48B.

[0191]

[20] The power holding unit 98 may be composed of a single holding relay interposed in the power transmission path from the battery 37 to the satellite navigation system 87 and the inertial measurement system 88, and a power control unit 60T that controls the operation of the holding relay.

[0192]

[21] The notification device 47 may be configured to perform a notification operation to urge the driver to start the engine 7 using the liquid crystal display unit 47A or the like while the power holding unit 98 is operating in the third power holding state.

[0193]

[22] The fault sensor 35A may be, for example, a jamming sensor for detecting jamming of seeds in each furrow former of the direct seeding device.

[0194]

[23] The spare storage section 59 may be a place where spare fertilizer bags can be placed. [Industrial Applicability]

[0195] The present invention can be applied to work vehicles such as riding rice transplanters, riding direct seeding machines, tilling tractors, plowing tractors, loader tractors, combines, riding lawn mowers, and wheel loaders, which are equipped with a liftable ground work device and perform work by traveling back and forth on a work site. [Explanation of symbols]

[0196] 1 Running vehicle 7 Engine 24 Storage section (seedling tray) 24A Remaining amount detection unit (first remaining amount detection unit) 31 Storage section (hopper) 31A Remaining amount detection unit (second remaining amount detection unit) 35A Malfunction sensor (clogging sensor) 37 Battery 47 Alarm device 47D Alarm section (third alarm section) 47E Notification Unit (4th Notification Unit) 47F Notification Department (5th Notification Department) 47G Alarm section (6th alarm section) 47H Alarm section (7th alarm section) 48 Driver's seat 48A 1st seat sensor 48B 2nd seat sensor 59 Reserve Storage Section 59D Spare remaining amount sensor 60G Operation Control Unit 60H Engine control unit 60K condition judgment section 60L Path setting section 60M Directional Control Unit 60N point memory section 60P arrival judgment part 60Q Vehicle speed control unit 60R Transition Estimation Section 60S Transition Detection Unit 61 Main switch 70 Transition detection unit 86 Positioning Unit 87 Satellite Navigation Device 88 Inertial Measurement Unit 94 Changeover switch (third changeover switch) 96 Changeover switch (4th changeover switch) 97 Changeover switch (5th changeover switch) 98 Energization holding part A Ground work equipment PC conversion start point Pd conversion start point Rs Target straight route Rsa Control Area

Claims

1. a positioning unit that measures at least one of the position and the orientation of the traveling vehicle body, a direction control unit that controls the traveling direction of the traveling vehicle body, a transition detection unit that detects a transition in the traveling state of the traveling vehicle body, and a work control unit that switches a ground work device connected to the traveling vehicle body so as to be able to rise and fall between a working state and a non-working state, The direction control unit executes an automatic straight-line control in a control target area of ​​a target straight-line route, based on the target straight-line route and the positioning result of the positioning unit, to automatically drive the traveling vehicle body on the target straight-line route, and executes an automatic direction change control to automatically change the direction of the traveling vehicle body from the target straight-line route currently being traveled to the next target straight-line route at a left turn start point or a right turn start point stored in a point storage unit, the work control unit executes non-working state switching control for switching the ground work device to the non-working state in conjunction with the transition detection unit detecting a transition from a straight-ahead state of the traveling vehicle body to a direction change state due to the automatic direction change control, and executes work state switching control for switching the ground work device to the working state in conjunction with the transition detection unit detecting a transition from a direction change state of the traveling vehicle body to a straight-ahead state, a reach determination unit that determines whether the traveling vehicle body has reached the left turn start point or the right turn start point, In the automatic direction change control, the direction control unit performs a left direction change process when the arrival determination unit detects that the traveling vehicle body has reached the left turn start point, and performs a right direction change process when the arrival determination unit detects that the traveling vehicle body has reached the right turn start point.

2. A path setting unit is provided that determines a reference direction that is an extension direction of the target straight path based on the execution of teaching control, The work vehicle according to claim 1 , wherein the direction control unit performs automatic straight-line control based on the positioning result of the positioning unit and the reference direction.

3. 3. The work vehicle according to claim 1, further comprising a changeover switch for switching the direction control section between an execution state in which the automatic direction change control is performed and a non-execution state in which the automatic direction change control is not performed.

4. The work vehicle according to any one of claims 1 to 3, wherein the direction control unit, when determining that an execution condition for automatic straight-line control is satisfied, executes automatic straight-line control along the target straight-line path.

5. 5. The work vehicle according to claim 1, wherein when the direction control unit determines that a condition for executing automatic straight-line control is satisfied, the notification unit switches from a flashing state to a lit state.

Images