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

Abstract

To suppress deterioration in running feeling when starting an electricity-driven crawler-type running vehicle after performing stop control.MEANS FOR SOLVING THE PROBLEM: A running control device of an electricity-driven crawler-type running vehicle is provided with a controller 60 that controls driving of crawler running devices 12a and 12b by controlling driving of running motors 51 and 52, in accordance with settings by operating a running control lever 47 and a steering-amount control dial 48. In a state where the crawler running devices 12a and 12b are being driven, when control by the running control lever 47 is stopped, the controller 60 lowers rotation speed of the running motors 51 and 52 to start stop control of the crawler running devices 12a and 12b; when the rotation speed of the running motors 51 and 52 lowers down to near zero, decreases driving force of the motors for a predetermined time; makes left and right brake devices brake and hold drive / output systems of the running motors 51 and 52; and successively performs stop control of stooping supply of driving electricity to the 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, for example, when the vehicle stops traveling while traveling uphill, there is a problem that the vehicle moves 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 traveling, it is generally controlled to first activate the parking brake and then stop the drive of the electric motor. [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 used 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 there remains internal stress greater than the driving force for starting the crawler traveling device, 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-off 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 these problems, and has an object to provide a driving control device for an electric crawler traveling vehicle that can eliminate as much internal stress as possible that occurs in the crawler traveling device during stopping control, in which the parking brake is activated to stop the drive of the electric motor when the vehicle is stopped from a traveling state, thereby suppressing the problem of a decrease in the driving feeling when the vehicle subsequently starts moving off. [Means for solving the problem]

[0009] In order to solve the above problems, a travel control device for an electric crawler traveling vehicle according to a first aspect of the present invention is a travel control device that performs travel control of an electric crawler traveling vehicle that is configured to include 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 stopping braking devices (e.g., left and right brake devices 56, 57 in the embodiment) that brake and hold the drive output systems of the left and right electric motors when traveling is stopped, and the travel control device includes a travel operation device (e.g., travel operation lever 47 in the embodiment) that can be operated to set the travel direction and travel speed, a turning operation device (e.g., turning amount operation dial 48 in the embodiment) that can be operated to set the turning direction and turning amount, and and a motor drive control device (for example, controller 60 in an embodiment) that controls the drive of the left and right electric motors to control the drive of the left and right crawler travelling devices in accordance with the travel direction and travel speed set by the left and right electric motors and the turning direction and turning amount set by the turning operation device, and when the traveling operation device is operated to stop this traveling in a state in which the left and right crawler travelling devices are driven by the left and right electric motors, the motor drive control device initiates stop control to stop the left and right crawler travelling devices by reducing the rotation speeds of the left and right electric motors, and when the rotation speeds of the left and right electric motors have reduced to near zero, the drive forces of the left and right electric motors are reduced for a predetermined period of time, and then the stopping braking device brakes and holds the drive output systems of the left and right electric motors, and subsequently performs stop control to stop the supply of drive power to the left and right electric motors.

[0010] In the above-mentioned drive control device for the electric crawler traveling vehicle, preferably, in the stop control by the motor drive control device, the rotation speeds of the left and right electric motors are reduced to near zero. When the vehicle is stopped, the drive current values ​​of the left and right electric motors are reduced for the predetermined period of time, thereby reducing the drive forces of the left and right electric motors for the predetermined period of time.

[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 in the stop control by the motor drive control device, the driving forces of the left and right electric motors that are set by reducing the driving forces for the specified time are set so that the driving forces that are set by reducing them become larger as the inclination angle of the vehicle body increases.

[0012] The travel control device of the above-mentioned electric crawler travelling vehicle is preferably configured such that, in the stop control by the motor drive control device, the magnitude of the drive force set by reducing the drive force of the left and right electric motors for a predetermined time is set according to the travel mode based on the operation of the travel operation device and the turning operation device, and the drive force set by the reduction becomes larger in the order of the travel mode being stopping from straight travel, stopping from slalom turning travel, stopping from pivot turning travel, and stopping from spin turning travel.

[0013] The travel control device of the above-mentioned electric crawler travelling vehicle is preferably configured so that, in the stop control by the motor drive control device, the magnitude of the drive force set by reducing the drive forces of the left and right electric motors for the specified time is set in accordance with at least one of the motor drive torque, the crawler external force and the motor output shaft torque.

[0014] Next, a travel control device for an electric crawler traveling vehicle according to the second aspect of the present invention is a travel control device that performs travel control of an electric crawler traveling vehicle that is configured to include a vehicle body, left and right crawler traveling devices provided on the left and right sides of the vehicle body, left and right electric motors that drive the left and right crawler traveling devices, respectively, and a stop braking device that brakes and holds the drive output systems of the left and right electric motors when traveling is stopped, and includes a travel operation device that can be operated to set the travel direction and travel speed, a turning operation device that can be operated to set the turning direction and turning amount, and a travel control device that controls the drive of the left and right electric motors to turn the left and right electric motors 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 motor drive control device that controls drive of the right and left crawler travelling devices, and when the travel operation device is operated to stop the travelling while the left and right crawler travelling devices are driven by the left and right electric motors, the motor drive control device initiates stop control to reduce the rotation of the left and right electric motors to stop the left and right crawler travelling devices, and when the rotation speed of the left and right electric motors has decreased to near zero, controls the drive forces of the left and right electric motors to rotate in reverse for a predetermined time, and then brakes and holds the drive output systems of the left and right electric motors using the stopping braking device, and subsequently performs stop control to stop the supply of drive power to the left and right electric motors.

[0015] The driving control device of the above-mentioned electric crawler driving vehicle is preferably configured to include an inclination angle detector that detects the inclination angle of the vehicle body, and in the stop control by the motor drive control device, the execution time of the control to rotate the left and right electric motors in opposite directions for a predetermined period of time is set to become shorter as the inclination angle of the vehicle body becomes larger.

[0016] The driving control device of the above-mentioned electric crawler driving vehicle is preferably configured such that, in the stop control by the motor drive control device, the execution time of control to rotate the left and right electric motors in reverse directions for a predetermined period of time is set according to the driving mode based on the operation of the driving operation device and the turning operation device, and the control execution time is set so as to become longer in the order of driving modes: stopping from straight driving, stopping from slalom turning driving, stopping from pivot turning driving, and stopping from spin turning driving.

[0017] The travel control device of the above-mentioned electric crawler travelling vehicle is preferably configured such that, in the stop control by the motor drive control device, the execution time of control to rotate the left and right electric motors in reverse directions for a predetermined period of time is set in accordance with at least one of the motor drive torque, the crawler external force and the motor output shaft torque, the control execution time is set to be longer as the motor drive torque increases, the control execution time is set to be longer as the crawler external force increases, and the control execution time is set to be longer as the motor output shaft torque increases. Effect of the Invention

[0018] According to the travel control device for an electric crawler traveling vehicle of the first invention, when the travel operation device is operated to stop the travel while the left and right crawler traveling devices are driven by the left and right electric motors, the motor drive control device starts stop control 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 drops to near zero, reduces the drive force of the left and right electric motors for a predetermined time. Then, the stopping brake device brakes and holds the drive output system of the left and right electric motors, and then performs stop control to stop the supply of drive power to the left and right electric motors, so that internal stress due to elastic deformation of the crawler belts generated during traveling can be released, and when the vehicle starts moving thereafter, the traveling shock generated at the time of starting in the conventional control can be suppressed, and the starting driving feeling is not impaired.

[0019] In addition, in the stop control by the motor drive control device, when the rotation speeds of the left and right electric motors drop to near zero, it is preferable to reduce the drive current values ​​of the left and right electric motors for the specified period of time to reduce the drive forces of the left and right electric motors for the specified period of time, thereby making it possible to accurately and easily control the reduction in the drive forces of the left and right electric motors.

[0020] In addition, a tilt angle detector is provided to detect the tilt angle of the vehicle body, and in the stop control by the motor drive control device, the driving forces of the left and right electric motors are set by reducing them for the specified period of time, and the driving forces set by the reduction are preferably set so that they increase as the tilt angle of the vehicle body increases, thereby enabling accurate and precise stop control on slopes.

[0021] Furthermore, in the stop control by the motor drive control device, the magnitude of the drive force set by reducing the drive force of the left and right electric motors for a predetermined period of time is set according to the driving mode based on the operation of the driving operation device and the turning operation device, and it is preferable that the drive force set by the reduction becomes larger in the order of the driving mode: stopping from straight driving, stopping from slalom turning driving, stopping from pivot turning driving, and stopping from spin turning driving.This allows the stop control to be performed accurately and precisely according to the driving mode, i.e., according to the internal stress of the crawler belt which differs depending on the driving mode.

[0022] Furthermore, in the stop control by the motor drive control device, it is preferable that the magnitude of the drive force set by reducing the drive forces of the left and right electric motors for the specified period of time is set in accordance with at least one of the motor drive torque, the crawler external force, and the motor output shaft torque, thereby enabling the stop control to be performed accurately and precisely in response to these torques and external forces.

[0023] According to the second aspect of the present invention, in a state where the left and right crawler traveling devices are driven by the left and right electric motors to travel, the motor drive control device controls the left and right crawler traveling devices to stop the travel when the travel operation device is operated to stop the travel. When the rotation speed of the left and right electric motors drops to near zero, control is performed to rotate the driving force of the left and right electric motors in the reverse direction for a predetermined time. Then, the stopping brake device brakes and holds the driving output systems of the left and right electric motors, and then stopping control is performed to stop the supply of driving power to the left and right electric motors. This makes it possible to release internal stress due to elastic deformation of the crawler belts that occurs during traveling, and when the vehicle starts moving thereafter, it is possible to suppress traveling shocks that occur when starting with conventional control, and does not impair the starting driving feeling.

[0024] Furthermore, it is preferable that a tilt angle detector be provided for detecting the tilt angle of the vehicle body, and that in the stop control by the motor drive control device, the execution time of the control for rotating the left and right electric motors in opposite directions for a predetermined period of time be set to become shorter as the tilt angle of the vehicle body becomes larger, thereby enabling accurate and precise stop control on slopes.

[0025] In addition, in the stop control by the motor drive control device, the execution time of the control to rotate the left and right electric motors in reverse directions for a predetermined period of time is set according to the driving mode based on the operation of the driving operation device and the turning operation device, and it is preferable to set the control execution time so that it becomes longer in the order of the driving modes: stopping from straight driving, stopping from slalom turning driving, stopping from pivot turning driving, and stopping from spin turning driving.This allows the stop control to be performed accurately and precisely according to the driving mode, i.e., according to the internal stress of the crawler belt which differs depending on the driving mode.

[0026] Furthermore, in the stop control by the motor drive control device, the execution time of the control to rotate the left and right electric motors in reverse directions for a predetermined period of time is set in response to at least one of the motor drive torque, the crawler external force, and the motor output shaft torque, and is preferably set so that the control execution time becomes longer as the motor drive torque increases, the control execution time becomes longer as the crawler external force increases, and the control execution time becomes longer as the motor output shaft torque increases, thereby enabling stop control to be performed accurately and precisely in response to these torques and external forces. [Brief description of the drawings]

[0027] [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. [Figure 7] 4 is a graph showing a relationship between a vehicle body inclination angle and a torque limiting current. [Figure 8] 6 is a graph showing a relationship between a detection value of a motor driving torque and a correction coefficient of a torque limiting current. [Figure 9] 4 is a graph showing a relationship between a crawler external force and a torque limiting current. [Figure 10] 4 is a graph showing the relationship between a motor shaft torque and a torque limit current. [Figure 11] 10 is a graph showing the relationship between a vehicle body tilt angle and a control execution time. [Figure 12] 10 is a graph showing the relationship between a detected value of motor drive torque and a control execution time. [Figure 13] 11 is a graph showing the relationship between crawler external force and control execution time. [Figure 14] 4 is a graph showing the relationship between motor shaft torque and control execution time. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] 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.

[0029] 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 an electromagnetic force in response to a command signal.

[0030] 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).

[0031] The outputs of the left and right travel motors 51, 52 are transmitted to the left and right drive wheels 13, 13 via 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 in the traveling body 10 via left and right travel inverters 53, 54, respectively, to rotate the left and right drive wheels 13, 13. 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 traveling, etc. 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.

[0032] 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 telescopically moved 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 telescoping of the mast 20.

[0033] 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. The hydraulic pump 70 is driven by a pump drive motor 75. The pump drive motor 75 is driven to rotate by power supplied from a battery 90 via 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, which will be described later.

[0034] 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.

[0035] 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.

[0036] 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 reverse travel command for the left and right crawler travel devices 12a, 12b, and the larger the tilting operation amount, the higher the target travel speed during reverse travel is set in the travel control unit 60b. The operation of returning the travel control lever 47 to the neutral position corresponds to a stop command for the left and right crawler travel devices 12a, 12b.

[0037] 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. This operation corresponds to a command (straight ahead travel command) for setting the amount of rotation of the left and right crawler travel devices 12a, 12b to zero.

[0038] 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.

[0039] 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.

[0040] When the turning amount operation dial 48 is operated and a turning amount command signal (a signal corresponding to the twisting operation direction and operation amount based on the neutral position of the turning operation dial 48) is input to the traveling control unit 60b, the target turning traveling speed of each of the left and right crawler traveling devices 12a, 12b is set in response to the turning amount command signal, and the rotation speed of the left and right traveling motors 51, 52 is controlled so that the traveling speed of the left and right crawler traveling devices 12a, 12b becomes the target turning traveling speed. Specifically, the traveling speed of the left and right crawler traveling devices 12a, 12b is controlled according to the operation of the turning amount operation dial 48, and slalom turning traveling, pivot turning traveling, and spin turning traveling 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, slalom turning traveling to the right is performed within a range where the operation amount is small, pivot turning traveling to the right is performed as the operation amount increases, and spin turning traveling to the right is performed as the operation amount increases further.

[0041] 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, and when the traveling control lever 47 is returned to the neutral position from a traveling state in this way (as described above, when the traveling control lever 47 is released, 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 will be described below.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] However, when such stop control is performed, the left and right brake devices 56, 57 are operated with the drive torque of the left and right traveling motors 51, 52 acting to brake and hold the left and right crawler traveling devices 12a, 12b, so 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.

[0046] 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.

[0047] 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.

[0048] 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 stop control in FIG. 5 is performed. FIG. 5, like FIG. 4, 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 operated to the left to the maximum turning operation position. This operation is the same as in FIG. 4, and the right travel motor 52 indicated by the solid line SR(O)-1 in FIG. 5 is turned to the left. A target rotation speed command is output to the left traveling motor 51 shown by the solid line SL(O)-1. The left and right travel motors 51 and 52 are controlled to rotate at the target speed, and the right travel motor 52 rotates at the actual speed indicated by the dashed line SR(A)-1. As a result, the left traveling motor 51 rotates as shown by the dashed line SL(A)-1. The traveling unit 12b is driven in the forward direction, the left crawler traveling unit 12a is driven in the backward direction, and the traveling body 10 performs a spin turn traveling.

[0049] 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.

[0050] The control when stopping the rotation of the left and right traveling motors 51, 52 in this way (control after time t1 in FIG. 5) will be described in detail with reference to FIG. 6. When the travel operation lever 47 is released at time t1 and returned to the neutral position, the operation input of the operation lever 47 switches from ON to OFF. At this point, the drive command output (referred to as servo output) of the left and right traveling motors 51, 52 remains ON, and control is performed to supply drive power to both motors so as to reduce the rotation speed of the left and right traveling motors 51, 52 in response to the reduction in the target rotation speed. In addition, the operation control output (referred to as brake output) of the left and right braking devices 56, 57 remains ON, and the left and right braking devices 56, 57 are in a released state of braking. As described above, the left and right braking devices 56, 57 are so-called negative brakes, so the brake output is turned ON to release the brakes.

[0051] In this way, the target rotation speeds of the left and right traveling motors 51, 52 are reduced, and when the rotation speed becomes nearly zero (for example, 10 rpm) (at time t11), control is performed to reduce the torque limit current of the left and right traveling motors 51, 52. The torque limit current specifies the maximum allowable current supplied to the left and right traveling motors 51, 52, and prevents a current greater than this (overcurrent) from flowing. In this embodiment, the torque limit current of the left and right traveling motors 51, 52 is set to 250 A, but this is reduced to 70 A at time t11. This control to reduce the torque limit current is performed for a very short time (40 msec in this example), and is returned to the original value (250 A) at time t12. When the torque limit current is reduced in this way, the drive current of the left and right traveling motors 51, 52 is temporarily suppressed (for 40 msec from time t11 to t12), and the drive torque of the left and right traveling motors 51, 52 is temporarily reduced.

[0052] Therefore, the internal stress caused by the elastic deformation of the crawler belt 16 due to spin traveling at that time acts on the left and right traveling motors 51, 52, and the actual rotation speed of the left and right traveling motors 51, 52 temporarily rotates in the opposite direction as shown by the symbol SC in Fig. 6. This releases the internal stress caused by the elastic deformation of the crawler belt 16. This phenomenon appears as rotation in the opposite direction as shown by the dashed lines SR(A)-3 and SL(A)-3 in Fig. 5. Note that the temporary rotation in the opposite direction of the actual rotation speed of the left and right traveling motors 51, 52 shown by the symbol SC is a change in motor rotation, which is not transmitted to the left and right crawler traveling devices 12a, 12b and does not impair the traveling feeling.

[0053] Furthermore, a predetermined time (e.g., 0.5 sec) after time t2 when the target rotation speed becomes zero (time t13), the brake output is turned OFF and braking is performed by the left and right brake devices 56, 57. Furthermore, a predetermined time (e.g., 0.5 sec) after (time t14), the servo output is turned OFF and the drive of the left and right travel motors 51, 52 is released (the drive power is set to zero). This completes the stop control.

[0054] FIG. 5 shows a case where, after the stop control is completed in this manner, 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 straight forward travel command is output. When the forward travel command is output at time t3 in this manner, the left and right travel motors 51, 52 start to be driven, and the braking by the left and right brake devices 56, 57 is released. At this time, since the internal stress acting on the crawler belt 16 is released as described above, the phenomenon of the left and right crawler travel devices 12a, 12b being driven in the direction opposite to the drive direction before stopping, as in the conventional start control shown in FIG. 4, does not occur. For this reason, as shown in FIG. 5, from time t3, the target rotation speed changes to the solid line SR(O)-4 and the line overlapping therewith. In response to the change shown by the solid line SL(O)-4, the actual rotation speed changes smoothly as shown by the dashed line SR(A)-4 and the overlapping dashed line SL(A)-4. By carrying out the driving control according to the present invention, it is possible to suppress the driving shock that occurs when starting with conventional control, and there is no loss of the driving feeling when starting.

[0055] In the above control, when the target rotation speeds of the left and right traveling motors 51, 52 decrease and reach nearly zero rotation speed (e.g., 10 rpm) (time t11), the torque limit currents of the left and right traveling motors 51, 52 are reduced, but the actual rotation speeds may be used instead of the target rotation speeds. That is, when the actual rotation speeds of the left and right traveling motors 51, 52 reach nearly zero rotation speed (e.g., 10 rpm), the torque limit currents of the left and right traveling motors 51, 52 may be reduced.

[0056] In the above control, the torque limiting current is temporarily reduced from 250 A to 70 A (for 40 msec from time t11 to t12) to release the internal stress caused by the elastic deformation of the crawler belt 16, but it is desirable to appropriately set the amount of reduction in the torque limiting current and the time for which it is reduced in accordance with the various conditions at that time. This will be explained below.

[0057] If the torque limiting current is set low, the motor drive torque required to stop the vehicle on a slope may be insufficient, causing the vehicle to travel downhill along the slope and making it impossible to stop the vehicle. For this reason, it is preferable to set the torque limiting current according to the inclination angle of the vehicle 10 detected by the inclination angle detector 81. Specifically, as shown in Fig. 7, it is preferable to set the torque limiting current so that the greater the inclination angle of the vehicle 10, the larger the torque limiting current.

[0058] 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, it is preferable to set the torque limit current value 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.

[0059] In addition, if the torque limit current is set lower than necessary, the motor drive torque for stopping the motor may act and cause it to rotate suddenly in the reverse direction. For this reason, the actual motor drive torque (=motor drive current) at that time is detected, and the torque limit current value is set according to the detected value. Specifically, as shown in Fig. 8, it is preferable to set a correction coefficient that increases as the detection value increases, and to correct the torque limiting current using this correction coefficient.

[0060] 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. Using the crawler external force detected in this manner, it is preferable to set the torque limiting current to be increased as the crawler external force increases, as shown in Figure 9.

[0061] It is also possible to find the internal stress occurring in the crawler belt 16 from the output shaft torque (or the shaft torque of the reducer connected thereto) of the left and right traveling motors 51, 52. Therefore, it is preferable to detect the output shaft torque (or the shaft torque of the reducer connected thereto) of the left and right traveling motors 51, 52 and set the torque limiting current to be larger as the shaft torque of the motor or reducer increases, as shown in Fig. 10.

[0062] As explained above, in the above stop control, when the travel control lever 47 is returned to the neutral position and the rotation speeds of the left and right travel motors 51, 52 become nearly zero, the torque limiting current of the left and right travel motors 51, 52 is temporarily reduced to release the internal stress due to the elastic deformation of the crawler belt 16, but instead of this, the second stop control described below may be performed. The second stop control is a control that temporarily rotates the left and right travel motors 51, 52 in the opposite direction when the travel control lever 47 is returned to the neutral position and the target rotation speeds of the left and right travel motors 51, 52 become nearly zero.

[0063] The second stop control focuses on the fact that when, in the above-mentioned stop control (first stop control), the torque limiting current is reduced to temporarily reduce the drive torque of the left and right traveling motors 51, 52, the internal stress caused by the elastic deformation of the crawler belt 16 due to spin driving at that time acts on the left and right traveling motors 51, 52, resulting in rotation in the opposite direction as shown by dashed lines SR(A)-3 and SL(A)-3 in Figure 5, and performs stop control to cause such rotation in the opposite direction.

[0064] 5, for example, 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 position, the right crawler travel unit 12b is driven forward, the left crawler travel unit 12a is driven backward, and the travel body 10 is in a spin turning traveling state. When the travel control lever 47 is returned to the neutral position, the left and right travel motors 51, 52 are temporarily driven in the opposite direction. This makes it possible to release the internal stress due to the elastic deformation of the crawler belt 16, and in the subsequent start control, it is possible to suppress the traveling shock at start that occurred in the conventional control, and it is not possible to impair the starting driving feeling.

[0065] It is desirable to appropriately set the control time (referred to as the "control execution time") during which the left and right travel motors 51, 52 are temporarily driven in the reverse direction in the second stop control in accordance with various conditions at that time. This will be described below.

[0066] If the control execution time is made longer, there is a risk that the vehicle may travel downhill along the slope when stopped on an uphill slope, so it is preferable to set the control execution time according to the inclination angle of the vehicle 10 detected by the inclination angle detector 81. Specifically, as shown in Fig. 11, it is preferable to set the control execution time to be shorter as the inclination angle of the vehicle 10 increases.

[0067] As described above, the internal stress generated in the crawler belt 16 tends to be larger when the crawler belt 16 is turning. In view of this, the control execution time is set to be longer when the crawler belt 16 is stopped after moving forward or backward in a straight line. It is preferable to set the time in the order of length for a stop from turning, a stop from a slalom turn, a stop from a pivot turn, and a stop from a spin turn.

[0068] Also, since setting the control execution time longer than necessary may cause the motor to suddenly rotate in the reverse direction, it is preferable to detect the motor drive torque (=motor drive current) at that time and set the control execution time according to the detected value. Specifically, it is preferable to set the control execution time to be longer as the detected value increases, as shown in Figure 12.

[0069] As described above, the internal stress generated in the crawler belt 16 can be obtained by detecting the crawler external force. Therefore, it is preferable to use the crawler external force detected by, for example, detecting the axial force acting on the external force imparting cylinder, and set the control execution time to be longer as the crawler external force increases, as shown in Figure 13.

[0070] Furthermore, as described above, it is also possible to determine 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 reducer connected thereto). Therefore, it is preferable to detect the output shaft torque of the left and right traveling motors 51, 52 (or the shaft torque of the reducer connected thereto) and set the control execution time to be longer as the shaft torque of the motor or reducer increases, as shown in Figure 14.

[0071] In the above embodiment, when performing stop control, the drive current value of the electric motor is controlled to reduce the drive force, but since the drive force is determined by a combination of the drive current and control execution time of the electric motor, the control execution time of the electric motor may be controlled to reduce the drive force. Also, in the above embodiment, when performing stop control, the rotation command value is fixed to rotate the drive force in the reverse direction, and the control execution time for rotating in the reverse direction for a predetermined time is controlled, but the rotation command value may be controlled to rotate the drive force in the reverse direction.

[0072] 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]

[0073] 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, The motor drive control device includes: When the left and right crawler traveling devices are driven by the left and right electric motors to travel, when the traveling operation device is operated to stop the traveling, starting a stop control for reducing the rotation speed of the left and right electric motors to stop the left and right crawler traveling devices; a stop control device for an electric crawler traveling vehicle, comprising: when the rotation speeds of the left and right electric motors have decreased to near zero, the drive forces of the left and right electric motors are reduced for a predetermined time, and then the stop braking device brakes and holds the drive output systems of the left and right electric motors, and subsequently the supply of drive power to the left and right electric motors is stopped.

2. In the stop control by the motor drive control device, 2. The travel control device for an electric crawler traveling vehicle according to claim 1, wherein when the rotation speeds of the left and right electric motors decrease to near zero, drive current values ​​of the left and right electric motors are reduced for the predetermined time, thereby reducing the drive forces of the left and right electric motors for the predetermined time.

3. a tilt angle detector for detecting a tilt angle of the vehicle body, 3. The travel control device for an electric crawler traveling vehicle according to claim 1 or 2, characterized in that, in the stop control by the motor drive control device, the drive forces of the left and right electric motors that are set by reducing them for the predetermined time are set so that the reduced drive forces that are set become larger as the inclination angle of the vehicle body becomes larger.

4. in the stop control by the motor drive control device, the magnitude of the drive force set by reducing the drive forces of the left and right electric motors for a predetermined time is set according to a travel mode based on the operation of the travel operation device and the turning operation device, 3. The driving control device for an electric crawler traveling vehicle according to claim 1 or 2, characterized in that the driving force that is reduced and set becomes larger in the order of the traveling mode from a stop after straight traveling, to a stop after slalom turning traveling, to a stop after pivot turning traveling, and to a stop after spin turning traveling.

5. 3. The travel control device for an electric crawler traveling vehicle according to claim 1 or 2, characterized in that, in the stop control by the motor drive control device, the magnitude of the drive force that is set by reducing the drive forces of the left and right electric motors for the predetermined time is set in accordance with at least one of a motor drive torque, a crawler external force, and a motor output shaft torque.

6. The electric crawler vehicle is configured to include a vehicle body, left and right crawler traveling devices provided on the left and right sides of the vehicle body, left and right electric motors for driving the left and right crawler traveling devices, respectively, and a stopping braking device for braking and holding the drive output systems of the left and right electric motors when the vehicle stops traveling. A driving control device that controls driving of a road-traveling vehicle, 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, The motor drive control device includes: When the left and right crawler traveling devices are driven by the left and right electric motors to travel, when the traveling operation device is operated to stop the traveling, starting a stop control for reducing the rotation speed of the left and right electric motors to stop the left and right crawler traveling devices; a control device for an electric crawler traveling vehicle, characterized in that, when the rotation speeds of the left and right electric motors drop to near zero, control is performed to rotate the drive forces of the left and right electric motors in reverse directions for a predetermined period of time, then the stopping brake device brakes and holds the drive output systems of the left and right electric motors, and subsequently stop control is performed to stop the supply of drive power to the left and right electric motors.

7. a tilt angle detector for detecting a tilt angle of the vehicle body, 7. The travel control device for an electric crawler traveling vehicle according to claim 6, wherein, in the stop control by the motor drive control device, an execution time of control to rotate the left and right electric motors in reverse directions for a predetermined time is set to become shorter as the inclination angle of the vehicle body becomes larger.

8. an execution time of the control for rotating the left and right electric motors in the reverse directions for a predetermined time in the stop control by the motor drive control device is set according to a traveling mode based on the operation of the traveling operation device and the turning operation device, 7. The travel control device for an electric crawler traveling vehicle according to claim 6, wherein the control execution time is set to be longer in the order of travel modes: stopping from straight travel, stopping from slalom turning travel, stopping from pivot turning travel, and stopping from spin turning travel.

9. an execution time of the control for rotating the left and right electric motors in the reverse directions for a predetermined time in the stop control by the motor drive control device is set in accordance with at least one of a motor drive torque, a crawler external force, and a motor output shaft torque; the control execution time is set to be longer as the motor drive torque increases, The control execution time is set to be longer as the crawler external force increases, 7. The travel control device for an electric crawler traveling vehicle according to claim 6, wherein the control execution time is set to be longer as the motor output shaft torque increases.

Images