Running control device of electricity-driven crawler-type running vehicle

Abstract

To suppress deterioration in running feeling when starting an electricity-driven crawler running-type vehicle after performing stop control.SOLUTION: A running control device of an electricity-driven crawler-type running vehicle is provided with: a controller 60 that controls driving of left and right crawler running devices 12a and 12b by controlling driving of left and right running motors 51 and 52, in accordance with a running direction and running speed set by a running control lever 47 and a steering direction and a steering-amount set by a steering-amount control dial 48; and a stop control-state storing part that stores stop control-state information at the time of performing stop control. When performing starting-control while operating the running control lever 47 and the steering-amount control dial 48 in stopped states, the controller 60 performs control of driving the left and right running motors 51 and 52 on the basis of last stop control-state information stored in the stop control-state storing part, and then releases braking by left and right brake devices, and starts starting / running control of the left and right crawler running devices 12a and 12b by driving the left and right running motors 51 and 52.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a travel control device for an electric crawler traveling vehicle that has crawler traveling devices driven by electric motors on both the left and right sides of a vehicle body and is capable of traveling. [Background technology]

[0002] In an electric crawler traveling vehicle that has crawler traveling devices driven by electric motors on both the left and right sides of the vehicle body and can travel, a configuration is known in which the rotation direction and rotation speed of the left and right crawler traveling devices can be controlled according to the operation direction and operation amount of a travel operation lever and a steering operation dial (lever) to perform forward or backward straight traveling, slalom turning traveling, pivot turning traveling, and spin turning traveling (see, for example, Patent Document 1). Also known are crawler traveling vehicles equipped with two travel operation levers, one on each side, instead of the travel operation lever and the turning amount operation dial (see, for example, Patent Document 2), crawler traveling vehicles equipped with a travel lever for switching between forward and reverse, an accelerator pedal for setting the travel speed, and a handle for setting the turning direction and turning amount (see, for example, Patent Document 3), and crawler traveling vehicles equipped with a joystick-type travel operation device that can set forward, reverse, travel speed, turning direction, and turning amount with a single travel operation lever (see, for example, Patent Document 4).

[0003] An electric crawler traveling vehicle is generally equipped with a parking brake that holds the vehicle in a stopped state when the vehicle is stopped. Some parking brakes are operated by the driver each time the vehicle is parked, but many are configured to automatically activate the parking brake when the vehicle is parked using a parking brake called a negative brake. In the case of a configuration that automatically activates the parking brake in this way, if the parking brake is activated after the drive of the crawler traveling device by the electric motor is released, there is a problem that, for example, when the vehicle stops traveling while traveling on an uphill road, the vehicle will move backward or forward along the slope toward the downhill side between the release of the drive of the electric motor and the activation of the parking brake. For this reason, when the vehicle stops from a traveling state, a control is generally performed in which the parking brake is first activated and then the drive of the electric motor is stopped. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6080458 [Patent Document 2] JP 2003-343510 A [Patent Document 3] Japanese Utility Model Application Publication No. 5-24481 [Patent Document 4] JP 2002-104227 A Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, when the vehicle is stopped, the driving force of the electric motor acts on the crawler traveling device, and if the parking brake is applied in this state, the driving force of the electric motor continues to act on the crawler traveling device, and internal stress remains acting on the crawlers that make up the crawler traveling device. In crawler traveling devices used in aerial work vehicles, which are the subject of application of the present invention, rubber crawlers are often used as the crawlers, and rubber crawlers have the characteristic of having a large amount of elastic deformation. Due to this characteristic, when the driving force of the electric motor acts on the crawler traveling device, the rubber crawlers are subjected to a tensile elastic deformation by the driving force, and this tensile elastic force generates internal stress in the rubber crawlers. For this reason, particularly in the case of crawler traveling devices that use rubber crawlers, it is necessary to activate the parking brake when the vehicle is stopped and then operate the electric motor. When control is performed to stop the drive of the electric motor, the tensile elastic force generated in the rubber crawler due to the drive force of the electric motor remains as internal stress.

[0006] When conventional stop control is performed in this manner, that is, when the vehicle is stopped from a traveling state by first activating the parking brake and then stopping the drive of the electric motor, internal stress remains in the crawler of the crawler traveling device (particularly a crawler traveling device that uses rubber crawlers). Therefore, when the parking brake is subsequently released to start the crawler traveling device, if internal stress greater than the driving force for starting the crawler traveling device remains, this internal stress is applied to the crawler traveling device, causing the vehicle to move slightly, resulting in a problem of a deterioration in the driving feeling, such as a start-up shock.

[0007] This phenomenon of internal stress occurring in the crawler mainly occurs when stopping from slalom turning, pivot turning, and spin turning, but also occurs when stopping from normal forward or reverse traveling. This internal stress generally tends to be greater during turning, and tends to be greatest in the following order: stopping from forward or reverse straight traveling, stopping from slalom turning, stopping from pivot turning, and stopping from spin turning. The problem of driving shock occurring due to this internal stress when starting off and a deterioration in driving feeling tends to be greatest in this order.

[0008] The present invention has been made in consideration of such problems, and aims to provide a driving control device for an electric crawler traveling vehicle that can perform starting control that is not affected by internal stresses generated within the crawler traveling device, thereby suppressing the problem of a decrease in driving feeling when starting. [Means for solving the problem]

[0009] In order to solve the above problems, the travel control device for an electric crawler traveling vehicle according to the present invention is an electric crawler traveling device that includes a vehicle body (e.g., traveling body 10 in the embodiment), left and right crawler traveling devices (e.g., left and right crawler traveling devices 12a, 12b in the embodiment) provided on the left and right sides of the vehicle body, left and right electric motors (e.g., left and right traveling motors 51, 52 in the embodiment) that drive the left and right crawler traveling devices, respectively, and a stopping braking device (e.g., left and right brake devices 56, 57 in the embodiment) that brakes and holds the drive output systems of the left and right electric motors when traveling is stopped. a travel control device for controlling the travel of a vehicle, the travel control device including a travel operation device (e.g., a travel operation lever 47 in the embodiment) operable to set a travel direction and a travel speed, a turning operation device (e.g., a turning amount operation dial 48 in the embodiment) operable to set a turning direction and a turning amount, and a motor drive control device (e.g., a controller 60 in the embodiment) that controls the drive of the left and right electric motors to control the drive of the left and right crawler travel devices in accordance with the travel direction and travel speed set by the travel operation device and the turning direction and turning amount set by the turning operation device; and a stop control state memory unit (for example, stop control state memory unit 60c in an embodiment) that stores stop control state information when stop control is performed to stop the left and right crawler traveling devices by reducing the rotation speed of the left and right electric motors from a state in which the left and right crawler traveling devices are driven by the left and right electric motors to travel, and when the traveling operation device is operated to perform start control in a state in which the stop braking device has braked and held the drive output systems of the left and right electric motors to stop traveling, the motor drive control device controls the driving of the left and right electric motors based on the previous stop control state information stored in the stop control state memory unit, then releases the braking by the stop braking device and starts travel control of the left and right crawler traveling devices by driving the left and right electric motors.

[0010] In the above-mentioned driving control device for an electric crawler traveling vehicle, preferably, The storage unit updates and stores the stop control status information at that time every time stop control is performed to stop the left and right crawler traveling devices, and always stores the latest stop control status information.

[0011] The driving control device of the above-mentioned electric crawler driving vehicle preferably includes an inclination angle detector that detects the inclination angle of the vehicle body, and when the motor drive control device performs the starting control, controls the driving of the left and right electric motors based on the vehicle body inclination angle detected by the inclination angle detection value in addition to the previous stop control state information stored in the stop control state memory unit.

[0012] In the above-mentioned travel control device for an electric crawler traveling vehicle, preferably, the stop control state memory unit determines drive current values ​​of the left and right electric motors at the time of stopping from the actual rotation speeds or target rotation speeds of the left and right electric motors when stop control is performed to reduce the rotation speeds of the left and right electric motors and stop the left and right crawler traveling devices, and stores the drive current values ​​thus determined as the stop control state information.

[0013] In the above-mentioned travel control device for an electric crawler traveling vehicle, preferably, the stop control state memory unit is configured to store, as the stop control state information, the travel mode when stop control is performed to stop the left and right crawler traveling devices by reducing the rotation speed of the left and right electric motors, the travel mode being a stop from straight traveling, a stop from slalom turning traveling, a stop from pivot turning traveling, and a stop from spin turning traveling, and in the start control, when control is performed to drive the left and right electric motors based on the previous stop control state information stored by the stop control state memory unit, control is performed to increase the drive force of the left and right electric motors in the order of a stop from straight traveling, a stop from slalom turning traveling, a stop from pivot turning traveling, and a stop from spin turning traveling.

[0014] In the above-mentioned drive control device for the electric crawler traveling vehicle, preferably, the stop control state memory unit stores, as the stop control state information, at least one of a motor drive torque, a crawler external force, and a motor output shaft torque when stop control is performed to reduce the rotation speeds of the left and right electric motors and stop the left and right crawler traveling devices.

[0015] In the travel control device for the above-mentioned electric crawler traveling vehicle, preferably, the stop control by the motor drive control device is performed when the travel operation device is operated to stop the traveling while the left and right electric motors are driving the left and right crawler traveling devices, and control is initiated to reduce the rotation speed of the left and right electric motors to stop the left and right crawler traveling devices, and when the rotation speed of the left and right electric motors has decreased to near zero, the stop braking device brakes and holds the drive output systems of the left and right electric motors, and then control is performed to stop the supply of drive power to the left and right electric motors. Effect of the Invention

[0016] According to the travel control device for an electric crawler traveling vehicle of the present invention, when the travel operation device is operated to perform start control while the drive output systems of the left and right electric motors are held braked and stopped by the stop braking device, the motor drive control device controls the driving of the left and right electric motors based on the previous stop control state information stored in the stop control state storage unit, and then releases the braking by the stop braking device and starts travel control of the left and right crawler traveling devices by driving the left and right electric motors, so that smooth start control can be performed without being affected by internal stress of the crawler traveling devices. This makes it possible to suppress travel shocks at start that occurred in conventional start control, and does not impair the starting travel feeling. In other words, if internal stress remains in the crawler belt from the previous stop control, this internal stress can be offset. Once this state is achieved, the braking by the stopping braking device is released and travel control of the left and right crawler traveling devices is started, so that smooth start control can be performed without being affected by any internal stress remaining in the crawler belt.

[0017] In the drive control device for the above-mentioned electric crawler traveling vehicle, it is preferable that the stop control status memory unit updates and stores the stop control status information at that time each time stop control is performed to stop the left and right crawler traveling devices, and always stores the latest stop control status information, thereby making it possible to always perform appropriate start control based on the most recent stop control status information.

[0018] In the driving control device of the above-mentioned electric crawler driving vehicle, it is preferable to include an inclination angle detector that detects the inclination angle of the vehicle body, and when the starting control is performed by the motor drive control device, control is performed to drive the left and right electric motors based on the vehicle body inclination angle detected by the inclination angle detection value in addition to the previous stop control state information stored in the stop control state memory unit, thereby enabling starting control on slopes to be performed accurately and precisely.

[0019] In the travel control device for the above-mentioned electric crawler traveling vehicle, it is preferable that the stop control state memory unit determines the drive current values ​​of the left and right electric motors at the time of stopping from the actual rotation speeds or target rotation speeds of the left and right electric motors when stop control is performed to reduce the rotation speeds of the left and right electric motors and stop the left and right crawler traveling devices, and stores the drive current values ​​thus determined as the stop control state information, thereby supplying drive currents so as to reproduce the drive current values ​​of the left and right electric motors in the previous stop control, and performing accurate and smooth start control without being affected by internal stress remaining in the crawler belt from the previous stop control.

[0020] In the travel control device for the electric crawler traveling vehicle described above, the stop control state memory unit uses the travel mode when stop control is performed to stop the left and right crawler traveling devices by reducing the rotation speed of the left and right electric motors, for example, a stop from straight traveling, a stop from slalom turning traveling, a stop from pivot turning traveling, and a stop from spin turning traveling, as the stop state control information, and when control is performed to drive the left and right electric motors in the start control, it is preferable to control so that the drive forces of the left and right electric motors are increased in the order of a stop from straight traveling, a stop from slalom turning traveling, a stop from pivot turning traveling, and a stop from spin turning traveling, thereby reproducing the stop control state in the travel mode in the previous stop control, and enabling accurate and smooth start control to be performed.

[0021] In the travel control device for the above-mentioned electric crawler traveling vehicle, it is preferable that the stop control state memory unit stores as the stop control state information at least one of the motor drive torque, the crawler external force, and the motor output shaft torque when stop control is performed to stop the left and right crawler traveling devices by reducing the rotation speeds of the left and right electric motors, thereby reproducing the states of the motor drive torque, the crawler external force, and the motor output shaft torque in the previous stop control, thereby enabling accurate and smooth start control to be performed.

[0022] In the travel control device for the electric crawler traveling vehicle described above, the stop control by the motor drive control device is performed when the travel operation device is operated to stop the traveling while the left and right crawler traveling devices are driven by the left and right electric motors, and control to stop the left and right crawler traveling devices by reducing the rotation speed of the left and right electric motors is started, and when the rotation speed of the left and right electric motors has decreased to near zero, the stopping braking device brakes and holds the drive output systems of the left and right electric motors, and then control to stop the supply of drive power to the left and right electric motors is performed. In this case, if there is internal stress in the crawler belt when it is stopped, this will remain as it is, but when it starts moving, By creating a state in which the internal stress remaining in the crawler belt from the previous stopping control can be offset, and then releasing the braking by the stopping braking device and starting the running control of the left and right crawler running devices, it is possible to perform good starting control without being affected by the internal stress remaining in the crawler belt. [Brief description of the drawings]

[0023] [Figure 1] 1 is a side view of an aerial work vehicle as an example of an electric crawler traveling vehicle equipped with a travel control device according to the present invention. [Diagram 2] FIG. 2 is a block diagram showing an operation control configuration of the aerial work vehicle. [Diagram 3] 4 is a control system diagram of the left and right crawler traveling devices in the above-mentioned vehicle for working at height. FIG. [Figure 4] 4 is a graph showing a change in motor rotation speed caused by travel control of a conventional electric crawler traveling vehicle. [Diagram 5] 5 is a graph showing a change in motor rotation speed caused by travel control of an electric crawler traveling vehicle to which the present invention is applied. [Figure 6] 5 is a graph showing time variations in various input / output data and numerical values ​​when performing stop control of an electric crawler traveling vehicle to which the present invention is applied. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 shows a self-propelled vehicle for working at height 1 as an example of an electric crawler traveling vehicle equipped with a traveling control device according to the present invention. This vehicle for working at height 1 is configured with a traveling body 10, a mast 20 that extends vertically provided on the upper front side of the traveling body 10, and a work platform 30 provided on the upper part of the mast 20.

[0025] The traveling body 10 has a left crawler traveling device 12a and a right crawler traveling device 12b provided on both the left and right sides of the traveling body frame 11 (see FIG. 3). The left and right crawler traveling devices 12a and 12b each have a driving wheel 13 provided on the front side of the traveling body frame 11, a driven wheel 14 provided on the rear side of the traveling body frame 11, a plurality of rollers 15 provided between the driving wheel 13 and the driven wheel 14, a rubber crawler belt 16 (track) wrapped around the driving wheel 13, the driven wheel 14 and the plurality of rollers 15, traveling motors 51 and 52 (see FIG. 3) that rotate the driving wheel 13, and brake devices 56 and 57 (see FIG. 2) that brake the rotation of the driving wheel 13. The left and right brake devices 56 and 57 are electromagnetic brakes that are driven by command signals from a controller 60, which will be described later. The left and right brake devices 56, 57 are what are known as negative brakes, which are fully operational when there is no command signal, and adjust the braking force by operating electromagnetic force in response to a command signal.

[0026] Although not shown, an external force imparting cylinder is provided that acts in a direction to move the drive wheel 13 and the driven wheel 14 apart from each other in order to maintain the tension of the crawler belt 16 that is wound around the drive wheel 13 and the driven wheel 14. The external force imparting cylinder is configured, for example, by filling the cylinder with grease, and when slack occurs in the crawler belt 16, it is possible to eliminate the slack in the crawler belt 16 by sending grease into the cylinder using a grease filler (grease gun) to expand the external force imparting cylinder. By detecting the axial force acting on this external force imparting cylinder, it is possible to detect the tension acting on the crawler belt 16 wound around the drive wheel 13 and the driven wheel 14 (the external force acting on the crawler belt 16, which is referred to as the crawler external force).

[0027] The outputs of the left and right travel motors 51, 52 are transmitted to the left and right drive wheels 13, 13 via speed reducers (not shown), respectively, so that the left and right drive wheels 13, 13 are rotated. As shown in FIG. 2, the left and right travel motors 51, 52 are driven by power supplied from a battery 90 provided on the traveling body 10 via left and right travel inverters 53, 54, respectively. The left and right travel motors 51, 52 are driven by the left and right drive wheels 13, 13 to rotate. The left and right travel motors 51, 52 also have a function of generating regenerative electricity by being rotated by the left and right drive wheels 13, 13 during deceleration or the like. The left and right travel motors 51, 52 are adapted to have their rotation direction and rotation speed controlled according to the operation direction and operation amount of a travel operation lever 47 and a turning amount operation dial 48 provided in an operation box 40, which will be described later.

[0028] As shown in Figure 1, the mast 20 is configured to be vertically telescopic by combining a base end mast member 21 attached to the upper front side of the running body 10, a lower intermediate mast 22, an upper intermediate mast 23, and a tip mast 24 in a nested manner. The mast 20 is provided with a telescopic cylinder 25 (see Figure 2) therein, and is configured so that the entire mast 20 can be telescopic in the vertical direction by telescoping this telescopic cylinder 25. The tip mast 24 is provided with a work platform 30 that moves up and down in accordance with the telescopic extension and retraction of the mast 20.

[0029] As shown in Fig. 2, the telescopic cylinder 25 is driven by hydraulic oil discharged from a hydraulic pump 70 provided on the traveling body 10 and supplied through a telescopic control valve 71 to extend and retract the mast 20. The hydraulic pump 70 is driven by a pump drive motor 75. The pump drive motor 75 is rotated by power supplied from a battery 90 through a mast operation inverter 76. The operation direction and operation speed of the telescopic cylinder 25 are controlled according to the operation direction and operation amount of a mast operation lever 41 provided in an operation box 40 described later.

[0030] As shown in Fig. 1, an operation box 40 equipped with various operation means is provided on the work platform 30 (or on the top of the tip mast 24). The operation box 40 is provided with a mast operation lever 41 for operating the extension and contraction of the mast 20 (operating to raise and lower the work platform 30). The mast operation lever 41 can be tilted forwards and backwards from a neutral position extending vertically, and is configured so that when the lever is released from a tilted state, it automatically returns to the neutral position by the force of a built-in spring. When the mast operation lever 41 is tilted, a mast operation signal is output corresponding to the tilt direction and amount of operation with respect to the neutral position, and is input to a mast operation control section 60a of the controller 60.

[0031] The mast operation control unit 60a electromagnetically drives the spool of the extension / retraction control valve 71 in a direction and amount according to the input mast operation signal to control the amount of hydraulic oil supplied from the hydraulic pump 70 to the telescopic cylinder 25, thereby controlling the operation direction and operation speed of the telescopic cylinder 25. In addition, the mast operation control unit 60a controls the power supplied from the battery 90 to the pump drive motor 75 via the mast operation inverter 76 in response to the input mast operation signal, thereby controlling the amount of hydraulic oil discharged from the hydraulic pump 70. Therefore, a worker on the work platform 30 can extend and retract the mast 20 by operating the mast operation lever 41, thereby raising and lowering the work platform 30 to a desired height position.

[0032] The operation box 40 is provided with a travel operation lever 47 and a turning amount operation dial 48 for operating the left and right crawler traveling devices 12a and 12b. As shown in FIG. 3, the travel operation lever 47 can be tilted forward and backward from a neutral position extending vertically, and when the hand is released from the tilted state, the lever is automatically returned to the neutral position by the force of a built-in spring. When the travel operation lever 47 is tilted, a travel command signal corresponding to the tilt operation direction and operation amount based on the neutral position is output and input to the travel control unit 60b of the controller 60. The forward tilt operation of the travel operation lever 47 from the neutral position corresponds to a forward travel command for the left and right crawler traveling devices 12a and 12b, and the larger the tilt operation amount, the higher the target travel speed during forward travel is set in the travel control unit 60b. The tilting operation of the travel control lever 47 backward from the neutral position corresponds to a backward travel command for the left and right crawler travel devices 12a, 12b. The target travel speed during reverse travel is set to a large value in the travel control unit 60b. The operation of returning the travel control lever 47 to the neutral position corresponds to a command to stop the left and right crawler travel devices 12a, 12b.

[0033] The turning amount operation dial 48 can be twisted left and right from a neutral position (position shown in FIG. 3), and is configured to automatically return to the neutral position by the force of a built-in spring when the twisted state is released. When the turning amount operation dial 48 is twisted, a turning amount command signal corresponding to the twisting direction and operation amount based on the neutral position is output and input to the traveling control unit 60b. Twisting the turning amount operation dial 48 to the right from the neutral position corresponds to a turning traveling command to the right of the left and right crawler traveling devices 12a, 12b, and the larger the twisting operation amount to the right from the neutral position, the larger the target turning amount to the right is set to in the traveling control unit 60b. A twisting operation of the turning amount control dial 48 to the left from the neutral position corresponds to a leftward turning travel command for the left and right crawler traveling devices 12a, 12b, and the larger the amount of twisting operation to the left from the neutral position, the larger the target turning amount to the left is set to in the travel control unit 60b. An operation of returning the turning amount control dial 48 to the neutral position corresponds to a command (straight running command) to set the amount of turning of the left and right crawler traveling devices 12a, 12b to zero.

[0034] The running object 10 is provided with an inclination angle detector 81 that detects the inclination angle of the running object 10 with respect to a horizontal plane. Information on the inclination angle of the running object 10 detected by the inclination angle detector 81 is input to the running control unit 60b of the controller 60.

[0035] The controller 60 includes a stop control state storage unit 60c as shown in FIG. 2. In the example shown in FIG. 2, the stop control state storage unit 60c is provided in the travel control unit 60b, but the stop control state storage unit 60c may be provided in the controller 60 or may be provided separately from the controller 60. The stop control state storage unit 60c stores stop control state information when stop control is performed to stop the left and right crawler traveling devices 12a, 12b by reducing the rotation speed of the left and right traveling motors 51, 52 from a state in which the left and right crawler traveling devices 12a, 12b are driven by the left and right traveling motors 51, 52 and traveling. The stop control state storage unit 60c stores at least the most recent stop control state information, for example, while updating it every time stop control is performed, and is used at the time of the next transmission control. This will be described later.

[0036] When a travel command signal (a signal corresponding to the tilt operation direction and operation amount based on the neutral position) is input from the travel operation lever 47, the travel control unit 60b of the controller 60 sets the target straight travel speed of the left and right crawler travel devices 12a, 12b corresponding to the travel command signal, and controls the power supplied to the left and right travel motors 51, 52 so that the travel speeds of the left and right crawler travel devices 12a, 12b both follow the target straight travel speed, thereby controlling the rotation speeds of the left and right travel motors 51, 52. At this time, when the turning amount operation dial 48 is not operated and a turning amount command signal (a signal corresponding to the twist operation direction and operation amount based on the neutral position of the turning operation dial 48) is not input, the travel control unit 60b controls the left and right travel motors 51, 52 to rotate at the same rotation speed so that both the left and right crawler travel devices 12a, 12b travel at the target straight travel speed. As a result, the traveling object 10 is controlled to travel straight in a traveling direction corresponding to the tilting operation direction of the traveling operation lever 47 at a speed corresponding to the amount of operation.

[0037] When the travel control lever 47 is tilted and a travel command signal is output, and the turning amount control dial 48 is operated to input a turning amount command signal (a signal corresponding to the direction and amount of twisting operation with respect to the neutral position of the turning operation dial 48) to the travel control unit 60b, the target turning travel speeds of the left and right crawler travel devices 12a, 12b are set in response to the turning amount command signal and the travel command signal, and the left and right crawler travel devices 12a, 12b are rotated. The rotation speeds of the left and right travel motors 51, 52 are controlled so that the travel speeds of the left and right crawler travel devices 12a, 12b become the respective target turning travel speeds. Specifically, the travel speeds of the left and right crawler travel devices 12a, 12b are controlled in response to the operation of the turning amount operation dial 48 and based on the travel command signal, and slalom turning travel, pivot turning travel, and spin turning travel can be performed according to the operation direction and operation amount. For example, when the turning amount operation dial 48 is rotated to the right, if the operation amount is small, slalom turning travel to the right will be performed, if the operation amount is large, pivot turning travel to the right will be performed, and if the operation amount is even larger, spin turning travel to the right will be performed.

[0038] As described above, the rotation direction and speed of the left and right traveling motors 51, 52 can be controlled according to the operation of the traveling control lever 47 and the turning amount control dial 48, and the traveling vehicle 10 can be made to travel straight ahead, turn in a slalom motion, turn in a pivot motion, or turn in a spin motion, but when the traveling control lever 47 is returned to the neutral position from a traveling state in this way (as described above, when the hand is released from the traveling control lever 47, the traveling control lever 47 automatically returns to the neutral position), control is performed to stop the traveling of the traveling vehicle 10. This stop control and the subsequent start control are described below.

[0039] First, in order to facilitate understanding of the object of the present invention, a conventional stop control will be described with reference to Fig. 4. In Fig. 4, the horizontal axis indicates elapsed time t, and the vertical axis indicates the motor rotation speed. In this figure, at time t0, the travel control lever 47 is tilted forward to output a forward travel command, and at the same time, the turning amount control dial 48 is operated to the left to the maximum turning operation position. As a result, travel control is performed in which the right travel motor 52 is driven to rotate forward (forward direction) at a rotation speed corresponding to the operation amount of the travel control lever 47, and the left travel motor 51 is driven to rotate reverse (reverse direction) at a rotation speed corresponding to the operation amount of the travel control lever 47.

[0040] Specifically, the target rotation speed for the right traveling motor 52 shown by the solid line SR(O)-1 in FIG. A rotation speed command is output, and the target rotation speed for the left traveling motor 52 is set as shown by the solid line SL(O)-1. The left and right running motors 51 and 52 are controlled to rotate at the target speed, and the right running motor 52 rotates at the actual speed indicated by the dashed line SR(A)-1. As a result, the right crawler travelling device 12b moves forward. The left crawler travelling device 12a is driven in the forward direction, the left crawler travelling device 12b is driven in the reverse direction, and the travelling body 10 performs a spin turn.

[0041] FIG. 4 shows a case where the travel control lever 47 is released and returned to the neutral position at time t1 while the vehicle is spinning. When the travel control lever 47 is returned to the neutral position, drive control is performed to return the rotation speeds of the left and right travel motors 51 and 52 to zero, and the target rotation speed decreases from time t1 as shown by solid lines SR(O)-2 and SL(O)-2. In response to this, the actual rotation speed decreases as shown by broken lines SR(A)-2 and SL(A)-2, and the rotation speeds of the left and right travel motors 51 and 52 become zero at time t2. As a result, the travel of the vehicle 10 stops, but the drive torques of the left and right travel motors 51 and 52 remain as the torques required to maintain the stopped state at that time. For example, the drive torque required to stop the vehicle while maintaining the spin travel drive remains acting. In this state, first, the left and right brake devices 56, 57 are operated to brake and hold the left and right crawler traveling devices 12a, 12b, and then the drive of the left and right traveling motors 51, 52 is released (the drive power is set to zero). As a result, for example, when the traveling body 10 is stopped on a slope, the left and right brake devices 56, 57 are first operated, so that it is possible to prevent the traveling body 10 from traveling down a slope when the drive of the left and right traveling motors 51, 52 is released.

[0042] However, when such a stop control is performed, the drive torque of the left and right traveling motors 51 and 52 is In this state, the left and right brake devices 56, 57 are operated to brake and hold the left and right crawler traveling devices 12a, 12b, so that the rubber crawler belt 16 is pulled and elastically deformed, and the left and right crawler traveling devices 12a, 12b are braked and held while maintaining internal stress. Therefore, even if the drive of the left and right traveling motors 51, 52 is subsequently released, the crawler belt 16 remains pulled and elastically deformed, and maintains internal stress.

[0043] FIG. 4 shows a case where, after stopping as described above, at time t3, the travel operation lever 47 is tilted forward and a forward travel command is output. At this time, the turning amount operation dial 48 is not operated, and a forward straight travel command is output. When a forward travel command is output at time t3, the left and right travel motors 51 and 52 start to be driven and the left and right brake devices 56 and 57 are released. At this time, the crawler belt 16 is pulled and elastically deformed as described above, and has internal stress. Therefore, when the braking by the left and right brake devices 56 and 57 is released, this internal stress is transmitted to the left and right crawler travel devices 12a and 12b, and the left and right crawler travel devices 12a and 12b are driven in the opposite direction to the driving direction before stopping, as shown by the dashed lines SL(A)-3 and SR(A)-3 in FIG. 4. Although this reverse drive is very short as shown in the figure, it is transmitted to the traveling body 10 as a traveling shock, causing a problem of a deterioration in the starting traveling feeling.

[0044] After this, normal starting control is performed, and the control is performed on the right traveling motor 52 as indicated by the solid line SR(O)-4. The target rotation speed command is output, and the left running mode indicated by the same solid line SL(O)-4 overlapping with it is output. A target rotational speed command is output to the left and right traveling motors 51 and 52. The left and right traveling motors 51 and 52 are controlled to rotate at this target speed, and the left and right traveling motors 51 and 52 perform actual rotation as shown by dashed line SR(A)-4 and the same dashed line SL(A)-4 that overlaps with it. As a result, the left and right crawler traveling devices 12a and 12b are driven at the same speed in the forward direction, and the traveling body 10 travels straight forward.

[0045] Next, the start control according to the present invention will be described with reference to Fig. 5 and Fig. 6. In Fig. 5, similarly to Fig. 4, the horizontal axis indicates the elapsed time t and the vertical axis indicates the motor rotation speed, and the starting control caused by the running control is shown. FIG. 6 is a graph showing the change in motor rotation speed when the transmission control in FIG. 5 is performed (time t3 in FIG. 5). As in FIG. 4, FIG. 5 shows a case where, at time t0, the travel operation lever 47 is tilted forward to output a forward travel command, and at the same time, the turning amount operation dial 48 is turned leftward to the maximum turning operation position. This operation is the same as in FIG. 4, and is indicated by the solid line SR(O)-1 in FIG. 5. A target rotation speed command is output to the right traveling motor 52, and is indicated by a solid line SL(O)-1. A target rotation speed command is output to the left traveling motor 51. The left and right traveling motors 51, 52 are controlled to rotate at this target speed, and the right traveling motor 52 rotates at an actual speed shown by the dashed line SR(A)-1, and the left traveling motor 51 rotates at an actual speed shown by the dashed line SL(A)-1. As a result, the right crawler traveling device 12b is driven in the forward direction, the left crawler traveling device 12a is driven in the reverse direction, and the traveling body 10 performs a spin turn traveling.

[0046] 5 shows a case where the driver releases the driving control lever 47 and returns it to the neutral position at time t1 while the vehicle is making a spin turn. When the driving control lever 47 is returned to the neutral position, the target rotation speeds of the left and right driving motors 51, 52 decrease from time t1 as shown by solid lines SR(O)-2 and SL(O)-2, and the actual rotation speeds decrease accordingly as shown by dashed lines SR(A)-2 and At time t2, the rotation of the left and right travel motors 51, 52 is decreased. The rotation number becomes zero.

[0047] The stop control at this time is the same as the conventional stop control shown in FIG. 4, and the left and right brake devices 56, 57 are operated to brake and hold the left and right crawler travel devices 12a, 12b, and then the drive of the left and right travel motors 51, 52 is released (the drive power is set to zero). As described above, while the drive torque of the left and right traveling motors 51, 52 is acting, the left and right brake devices 56, 57 are operated to brake and hold the left and right crawler traveling devices 12a, 12b, so that the rubber crawler belt 16 is pulled and elastically deformed, and the left and right crawler traveling devices 12a, 12b are braked and held while maintaining internal stress. Therefore, even if the drive of the left and right traveling motors 51, 52 is subsequently released, the crawler belt 16 remains pulled and elastically deformed, and maintains internal stress.

[0048] Fig. 5 shows a case where, after the stop control is thus completed, at time t3, the travel operation lever 47 is tilted forward, a forward travel command is output, and start control is performed. Note that at this time, the turning amount operation dial 48 is not operated, and a forward straight travel command is issued. When the forward travel command is output at time t3 in this way, the left and right travel motors 51, 52 start to be driven and the left and right brake devices 56, 57 are released. The present invention is used for this start control, which will be described in detail with reference to Fig. 6.

[0049] At time t3, when the travel operation lever 47 is tilted forward and a forward travel command is output, the operation input of the operation lever 47 switches from OFF to ON. As a result, the drive command output (called servo output) of the left and right travel motors 51, 52 switches from OFF to ON, and control is performed to supply drive power to both motors for driving the left and right travel motors 51, 52 in accordance with the target rotation speed. Note that at this point (time t3), the operation control output (called brake output) of the left and right brake devices 56, 57 remains OFF, and the left and right brake devices 56, 57 are in a braked state. As described above, the left and right brake devices 56, 57 are so-called negative brakes, so the brake output is OFF and the brakes are in an activated state.

[0050] Here, when the travel operation lever 47 is tilted forward at time t3 to output a forward travel command, the controller 60 controls the left and right travel motors 51, 52 to drive in the same direction as the rotation direction in the previous stop control (the rotation direction in the assumed stop control stored in the stop control state storage unit 60c). As shown in FIG. 6, this drive control controls the left and right travel motors 51, 52 to be supplied with a drive current (referred to as the "start control drive current MPS") corresponding to the drive force in the previous stop control so that the left and right travel motors 51, 52 are driven in the same direction as the rotation direction in the previous stop control during an extremely short period from time t3 to time t31. When the start control drive current MPS is supplied to the left and right travel motors 51, 52 in this manner, the left and right travel motors 51, 52 generate a drive force that countered the internal stress due to the elastic deformation of the crawler belt 16 in the previous stop control.

[0051] In this way, the left and right traveling motors 51, 52 are controlled to rotate in the same direction as the rotation direction during stop control (control to supply the start control drive current MPS), and once the left and right traveling motors 51, 52 generate a drive force that counteracts the internal stress due to the elastic deformation of the crawler belt 16, the target rotation speeds of the left and right traveling motors 51, 52 are set and output in response to a forward travel command as shown by solid line SR(O)-3 and the same solid line SL(O)-3 that overlaps therewith, as shown in Figure 5. At time t32 immediately after the control to supply the start control drive current MPS, the brake output is turned ON to release the braking by the left and right braking devices 56, 57. In this way, the rotation drive control based on the target rotation speed is performed from the state where the left and right travel motors 51, 52 generate a drive force that counteracts the internal stress caused by the elastic deformation of the crawler belt 16. Therefore, the phenomenon of driving the left and right crawler travel devices 12a, 12b in the direction opposite to the drive direction before stopping, as in the conventional start control shown in FIG. 4, does not occur, and the actual rotation speed is shown by the dashed lines SR(A)-3 and As shown by the overlapping identical dashed line SL(A)-3, the change is smooth. By carrying out the driving control according to the above, it is possible to suppress the driving shock that occurs when starting under conventional control, and the feeling of starting driving is not impaired.

[0052] In the above-mentioned stop control, the magnitude of the start control drive current MPS is basically set to a drive current corresponding to the drive force in the previous stop control, but it is preferable to appropriately set the magnitude of the start control drive current MPS depending on various conditions at that time. This will be described below.

[0053] For example, the magnitude of the start control drive current MPS required for stopping is different between the start control performed after stopping on flat ground and the start control performed after stopping on a slope. For this reason, it is preferable to set the start control drive current MPS according to the inclination angle of the traveling body 10 detected by the inclination angle detector 81. Specifically, it is preferable to estimate the required motor torque (torque current value) from the vehicle body inclination angle in the stopped state and store it in the stop control state storage unit 60c, and use the stored torque current value as the start control drive current MPS when performing the next start control. Note that the start control drive current MPS set in this way is set to a current value larger than the torque current value steadily required on a slope.

[0054] It is preferable to estimate the travel motor torque required for stopping from the actual rotation speeds of the left and right travel motors 51, 52 during the travel operation in the previous stop control and store it in the stop control state storage unit 60c, and when the next start control is performed, use the torque current value thus stored as the start control drive current MPS. Note that the travel motor torque required for stopping may also be estimated from the target rotation speeds of the left and right travel motors 51, 52 during the travel operation in the previous stop control and stored in the stop control state storage unit 60c.

[0055] As described above, the internal stress generated in the crawler belt 16 tends to be greater during turning, and tends to be greater in the following order: stopping from forward or backward straight traveling, stopping from slalom turning, stopping from pivot turning, and stopping from spin turning. For this reason, the start control drive current MPS may be set to be greater in the following order: stopping from forward or backward straight traveling, stopping from slalom turning, stopping from pivot turning, and stopping from spin turning.

[0056] Also, the motor drive torque (=motor drive current) immediately before the left and right brake devices 56, 57 were operated in the previous stop control may be detected, and the start control drive current MPS may be set according to this detected value.

[0057] The internal stress occurring in the crawler belt 16 can be obtained by detecting the crawler external force. The crawler external force can be obtained, for example, by detecting the axial force acting on the external force applying cylinder. The crawler external force thus detected may also be used to set the launch control drive current MPS.

[0058] It is also possible to obtain the internal stress generated in the crawler belt 16 from the output shaft torque of the left and right traveling motors 51, 52 (or the shaft torque of the reduction gear connected thereto). Therefore, the output shaft torque of the left and right traveling motors 51, 52 (or the shaft torque of the reduction gear connected thereto) may be detected, and the start control drive current MPS may be set using the output shaft torque thus detected.

[0059] As described above, in the above control, the value of the start control drive current MPS is appropriately set depending on various conditions at that time, but the setting time for setting the start control drive current MPS (the time from time t3 to t31 in Figure 6) may also be appropriately set depending on various conditions at that time.

[0060] In the above embodiment, a configuration including a travel operation lever 47 and a turning amount operation dial 48 has been described as a travel operation device, but the travel operation device may be a travel operation device including an accelerator pedal for setting the travel speed and a handle for setting the turning direction and turning amount, or a joystick-type travel operation device that allows forward movement, reverse movement, travel speed, turning direction and turning amount to be set by a single travel operation lever. Also, in the above embodiment, a high-altitude work vehicle including a mast 20 and a work platform 30 on the traveling body 10 has been described, but the present invention can also be applied to a high-altitude work vehicle including a boom-type or scissor-link-type high-altitude work device on the traveling body, or a traveling vehicle including a crane device or the like on the traveling body. [Explanation of symbols]

[0061] 1 Aerial work platform 10 Running body 11 Running body frame 12a Left side crawler running device 12b Right side crawler running device 40 Operation box 47 Travel control lever 48 Turn amount control dial 60 Controller 60b Travel control unit

Claims

1. A travel control device for controlling travel of an electric crawler travel vehicle comprising a vehicle body, left and right crawler travel devices provided on the left and right sides of the vehicle body, left and right electric motors for driving the left and right crawler travel devices, respectively, and a stop braking device for braking and holding drive output systems of the left and right electric motors when traveling is stopped, A travel operation device capable of setting a travel direction and a travel speed; A turning operation device capable of setting a turning direction and a turning amount; a motor drive control device that controls the drive of the left and right electric motors to control the drive of the left and right crawler travel devices in accordance with the travel direction and travel speed set by the travel operation device and the turning direction and turning amount set by the turning operation device; a stop control state storage unit that stores stop control state information when stop control is performed to stop the left and right crawler traveling devices by reducing the rotation speeds of the left and right electric motors from a state in which the left and right crawler traveling devices are driven by the left and right electric motors to travel, The motor drive control device includes: When the travel operation device is operated to perform start control in a state in which the stop braking device brakes and holds the drive output systems of the left and right electric motors to stop the vehicle from traveling, a stop control device for controlling a travel of an electric crawler traveling vehicle, characterized in that the device controls the driving of the left and right electric motors based on the previous stop control state information stored in the stop control state memory unit, releases braking by the stop braking device, and starts travel control of the left and right crawler traveling devices by driving the left and right electric motors.

2. 2. The travel control device for an electric crawler traveling vehicle according to claim 1, wherein the stop control state storage unit updates and stores the stop control state information at that time every time stop control is performed to stop the left and right crawler traveling devices, and always stores the latest stop control state information.

3. a tilt angle detector for detecting a tilt angle of the vehicle body, When the starting control is performed by the motor drive control device, 3. The travel control device for an electric crawler traveling vehicle according to claim 1 or 2, characterized in that control for driving the left and right electric motors is performed based on the vehicle body inclination angle detected by the inclination angle detection value in addition to the previous stop control state information stored in the stop control state storage unit.

4. 3. A travel control device for an electric crawler traveling vehicle according to claim 1 or 2, characterized in that the stop control state storage unit determines drive current values ​​of the left and right electric motors at the time of stopping from actual rotation speeds or target rotation speeds of the left and right electric motors when stop control is performed to stop the left and right crawler traveling devices by reducing the rotation speeds of the left and right electric motors, and stores the drive current values ​​thus determined as the stop control state information.

5. the stop control state storage unit is configured to store, as the stop control state information, a traveling mode when stop control is performed to stop the left and right crawler traveling devices by reducing the rotation speeds of the left and right electric motors, The running mode is a stop from a straight running, a stop from a slalom turning running, a stop from a pivot turning running, or a stop from a spin turning running, 3. The travel control device for an electric crawler traveling vehicle according to claim 1 or 2, characterized in that, during the start control, when control is performed to drive the left and right electric motors based on the previous stop control state information stored in the stop control state storage unit, control is performed to increase the drive forces of the left and right electric motors in the following order: stop from straight ahead traveling, stop from slalom turning traveling, stop from pivot turning traveling, and stop from spin turning traveling.

6. 3. The travel control device for an electric crawler traveling vehicle according to claim 1 or 2, characterized in that the stop control state memory unit stores, as the stop control state information, at least one of a motor drive torque, a crawler external force, and a motor output shaft torque when stop control is performed to stop the left and right crawler traveling devices by reducing the rotation speeds of the left and right electric motors.

7. The stop control by the motor drive control device includes: the left and right electric motors are used to drive the left and right crawler traveling devices to travel, and the travel operation device is operated to stop the travel, start a control for reducing the rotation speed of the left and right electric motors to stop the left and right crawler traveling devices; 3. The travel control device for an electric crawler traveling vehicle according to claim 1 or 2, characterized in that, when the rotation speeds of the left and right electric motors drop to near zero, the stopping braking device brakes and holds the drive output systems of the left and right electric motors, and then controls to stop the supply of drive power to the left and right electric motors.

Images