JP2012115048A - Travel controller of electric motor vehicle and electric motor vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a travel controller and an electric motor vehicle which can surely stop the vehicle at incorrect detection of leaving one's seat, while improving safety by implementing control against leaving one's seat .SOLUTION: In the travel controller provided with a speed commanding means 6 to command a target speed, a speed detector 12 to detect a vehicle speed, and a controller 11 to control a drive motor 17 so as to make the vehicle speed coincide with the target speed, the travel controller 10 is further provided with a seat-leaving detector 9 to detect whether or not an operator is not sitting on his (her) seat and a slope detector 13 to detect whether or not a track is sloped. The controller 11 controls the drive motor 17 regarding the target speed as zero when it is found that the operator is not sitting on his (her) seat and the track is sloped, and controls the motor regarding the target speed as a predetermined infinitesimal speed when it is found that the operator is not sitting on his (her) seat and that the track is not sloped.

Description

  The present invention relates to a travel control device for an electric vehicle that travels by driving a travel motor with electric power stored in a battery, and an electric vehicle.

  As a conventional electric vehicle, for example, a reach-type forklift shown in FIG. 5 is known. As shown in the figure, the forklift 100 includes a mast 3 that slides back and forth with respect to the vehicle body 2, a pair of forks 4 that move up and down along the mast 3, and drive wheels 7 that are provided at the lower part of the vehicle body 2. And. The vehicle body 2 has an operator seat 5 on which the operator stands while standing, and the operator seat 5 includes a lever for performing various operations in addition to an accelerator lever 6 and a foot-operated deadman brake 8. And a handle is provided. The drive wheel 7 is turnably attached to the vehicle body 2 and has a function as a steered wheel.

  As shown in FIG. 2, the forklift 100 moves forward at a speed corresponding to the tilt angle after the forward tilt when the accelerator lever 6 is tilted forward from the neutral position, and moves according to the tilt angle after the rear tilt when tilted backward. Go backwards. Further, when the accelerator lever 6 is returned to the neutral position, the forklift 100 performs neutral regeneration control and decelerates to a predetermined minute speed (for example, 1 km / h) (for example, see Patent Document 1).

  In this forklift 100, a plugging operation is frequently used in which the traveling motor is regeneratively controlled and decelerated by tilting the accelerator lever 6 to the opposite side in the traveling direction during forward or reverse travel.

JP-A-8-256401

  By the way, in the field of forklifts, in recent years, from the viewpoint of improving safety, it is possible to detect when an operator leaves the seat and perform control when leaving the seat to invalidate operation of the accelerator lever 6 and cargo handling operations such as raising and lowering the fork 4 Has come to be required. However, when the conventional forklift 100 performs the control when leaving the seat, the following problem may occur when the operator's leaving is erroneously detected.

  In other words, if an abnormality occurs while traveling on a hill and the operator's absence is erroneously detected, the operation of the accelerator lever 6 becomes invalid, and the forklift 100 is maintained at a very low speed under neutral regeneration control. Slope down the slope. At this time, even if the operator performs an accelerator operation in order to stop the forklift 100 from slipping, the operation of the accelerator lever 6 is invalid, and consequently the operator cannot stop the unintentional slipping. The forklift 100 may collide with another vehicle.

  Even during the away control, if the brake 8 is operated, the drive wheels 7 can be mechanically locked and the forklift 100 can be stopped. However, in the reach type forklift 100, the brake is often applied by the above plugging operation, and the brake 8 is used at the time of parking and is not used during traveling. It is extremely difficult to operate 8.

  The present invention has been made in view of the above circumstances, and the object of the present invention is to improve the safety by the control at the time of leaving the seat and reliably stop the vehicle when the seat is mistakenly detected. It is an object of the present invention to provide a travel control device that can be used and an electric vehicle including the travel control device.

  In order to solve the above-described problems, a travel control device according to the present invention includes a speed command means for commanding a target speed, a speed detection unit that detects a vehicle speed, and a travel speed so that the vehicle speed matches the target speed. In a travel control device comprising a control unit for controlling a motor for driving, an absence detection unit that detects whether or not the operator is away from the seat, and a slope detection unit that detects whether or not the travel path is a slope The control unit further comprises: when it is detected that the operator is away from the seat and the traveling path is a slope, the target speed is set to zero, the operator is away from the seat, and the traveling path When it is detected that the vehicle is not a slope, the traveling motor is controlled by setting the target speed to a predetermined minute speed.

In this configuration, when the absence detection of the operator is detected by the absence detection unit, the target speed is determined regardless of the speed command means (for example, the accelerator lever). That is, according to this configuration, since the operation of the accelerator lever is invalidated when the absence is detected, safety can be improved.
Further, in this configuration, when it is detected that the operator is away from the seat and the traveling path is a slope, the traveling motor is controlled so that the vehicle speed becomes zero. When the travel path is not a slope, the travel motor is controlled so that the vehicle speed becomes a very small speed, and then the electric vehicle naturally stops due to travel resistance. Therefore, according to this configuration, it is possible to reliably stop the electric vehicle when a seat separation is detected regardless of whether the traveling road is a slope.

When the speed detection unit of the travel control device detects the vehicle speed at regular intervals, the slope detection unit may detect that the travel road is a slope when the vehicle speed tends to increase.
According to this configuration, it is possible to detect whether the road is a slope with a relatively simple configuration.

  In order to solve the above-described problems, an electric vehicle according to the present invention includes the above-described travel control device.

  ADVANTAGE OF THE INVENTION According to this invention, the safety control by the control at the time of leaving a seat is aimed at, and the travel control apparatus which can stop a vehicle reliably when a seat leaving is mistakenly detected, and the electric motor provided with the travel control apparatus Car can be provided.

It is a perspective view of the reach type forklift concerning the present invention. It is a side view of an accelerator lever. It is a block diagram of the traveling control device concerning the present invention, and its peripheral member. It is a flowchart which shows operation | movement of the traveling control apparatus which concerns on this invention. It is a perspective view of the conventional reach type forklift.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of a travel control device and an electric vehicle according to the invention will be described with reference to the accompanying drawings. In the following, a reach-type forklift will be described as an example, but it goes without saying that the present invention is also applicable to other electric vehicles.

  FIG. 1 shows a reach-type forklift according to the present invention. As shown in FIG. 1, the forklift 1 includes a mast 3 that slides back and forth with respect to the vehicle body 2, a pair of forks 4 that move up and down along the mast 3, and drive wheels 7 that are provided at the lower portion of the vehicle body 2. And. The vehicle body 2 accommodates a traveling motor connected to the drive wheels 7 via a transmission gear, an inverter circuit that drives the traveling motor, a battery 16, a traveling control device according to the present invention, and the like. The drive wheel 7 is turnably attached to the vehicle body 2 and has a function as a steering wheel.

  The vehicle main body 2 has an operator seat 5 on which the operator gets on while standing. An operator lever of the operator seat 5 is provided with an accelerator lever 6, a lever for performing various operations, and a handle. At the operator's feet of the operator seat 5, a foot-operated deadman brake 8 and a leave switch 9 are provided. The accelerator lever 6 corresponds to speed command means of the present invention. Further, the absence switch detection floor switch 9 corresponds to the absence detection unit of the present invention.

  FIG. 3 shows a block diagram of the travel control device and its peripheral members according to the present invention. As shown in the figure, the travel control device 10 performs power running control or regenerative control of the travel motor 17 via an inverter circuit 15. In the power running control, the electric power of the battery 16 is supplied to the traveling motor 17 via the inverter circuit 15. On the other hand, in the regeneration control, the electric power generated by the traveling motor 17 is returned to the battery 16 via the inverter circuit 15.

  The brake 8 is provided independently of the travel control device 10. When the operator operates the brake 8, the drive wheel 7 is mechanically locked. Thereby, the forklift 1 stops immediately irrespective of the inclination angle of the accelerator lever 6.

  The travel control device 10 includes an accelerator lever 6, a floor switch 9 for detecting absence from the seat, a speed detection unit 12, a slope detection unit 13, and a control unit 11.

  The accelerator lever 6 is a lever for instructing a target vehicle speed (hereinafter referred to as a target speed). As shown in FIG. 2, when the vehicle body 2 moves forward and tilts backward from the neutral position, as shown in FIG. The vehicle body 2 moves backward. When the accelerator lever 6 is tilted forward or backward by the operator, the accelerator lever 6 outputs a signal corresponding to the tilt angle.

  The away switch detection floor switch 9 is provided so as to cover almost the entire floor of the operator seat 5. For this reason, when the operator gets on the forklift 1, the operator's weight is applied to the floor switch 9 for detecting the absence of seat, and the floor switch 9 for detecting the absence of seat outputs a signal indicating that the operator is not away. On the other hand, when the operator's weight is not applied, that is, when the operator is away, the away detection floor switch 9 outputs a signal indicating that the operator is away.

  The speed detection unit 12 detects the vehicle speed of the forklift 1 at regular intervals based on a rotation speed signal from an encoder provided on the rotation shaft of the traveling motor 17. Each time the speed detection unit 12 detects the latest vehicle speed, the speed detection unit 12 outputs a signal related to the vehicle speed toward the control unit 11 and the slope detection unit 13.

  The slope detection unit 13 detects whether or not the traveling road is a slope based on whether or not the vehicle speed detected by the speed detection unit 12 tends to increase. More specifically, when the vehicle speed detected at a certain time is V1, and the vehicle speed detected after the lapse of a certain time is V2, the slope detection unit 13 determines that the traveling road is a slope if V2-V1 is a positive value. Is detected.

  The control unit 11 controls the traveling motor 17 based on the tilt angle of the accelerator lever 6, the vehicle speed, whether the operator is away, and whether the traveling path is a slope.

  More specifically, when the absence of the operator is not detected (“No” in step S1 in FIG. 4), the traveling motor 17 is controlled by normal control (step S2).

  Here, the normal control is: (1) When the accelerator lever 6 is tilted forward or backward from the neutral position, power running control is performed so that the vehicle speed matches the target speed corresponding to the tilt angle of the accelerator lever 6. (2) When the accelerator lever 6 is returned to the neutral position, regenerative control is performed to decelerate to a predetermined minute speed (for example, 1 km / h), and (3) the accelerator lever is moved forward or backward. When 6 is tilted in the direction opposite to the traveling direction, the regeneration control is performed until the vehicle speed becomes zero, and then the power running control is performed so that the vehicle speed matches the target speed corresponding to the tilt angle.

  As shown in FIG. 4, the control unit 11 continues to control the traveling motor 17 by normal control until the operator's absence is detected.

  When the absence of the operator is detected (“Yes” in step S1), the traveling motor 17 is controlled by the control at the time of leaving (steps S3 to S5).

  As shown in FIG. 4, in the absence control, first, based on the detection result of the slope detection unit 13, it is determined whether or not the traveling road is a slope (step S3). When the traveling road is not a slope, vehicle deceleration control is performed (step S4), and when the traveling road is a slope, vehicle stop control is performed (step S5).

  In the vehicle deceleration control in step S4, the target speed is set to a predetermined minute speed (for example, 1 km / h) irrespective of the inclination angle of the accelerator lever 6, and the regeneration control of the traveling motor 17 is performed. Thereby, after forklift 1 decelerates to 1 km / h, it stops naturally by running resistance. On the other hand, in the vehicle stop control in step S5, the target speed is set to zero regardless of the inclination angle of the accelerator lever 6, and the regenerative control of the traveling motor 17 is performed. Thereby, the forklift 1 stops quickly.

  The reason why the vehicle deceleration control is performed instead of the vehicle stop control when the traveling path is not a slope is that a more comfortable ride can be realized.

  Eventually, according to the traveling control device 10 and the forklift 1 according to the present invention, the operation of the accelerator lever 6 is invalidated when the absence of a seat is detected, so that safety can be improved. In addition, according to the travel control device 10 and the forklift 1 according to the present invention, the vehicle can be stopped reliably when the absence is detected. Even if the absence is detected by mistake, the vehicle can be prevented from continuing to slide down the slope.

  The preferred embodiments of the travel control device and the electric vehicle according to the present invention have been described above, but the present invention is not limited to these configurations.

For example, the predetermined minute speed is not limited to 1 km / h, and may be an arbitrary speed at which the electric vehicle stops due to running resistance.
The speed detection method in the speed detection unit 12 and the slope detection method in the slope detection unit 13 are not limited to those described above, and various known methods may be used.
Further, in the case of an electric vehicle of a type that sits on a seat and operates, it is possible to detect the absence of seats in the same manner as the away switch detection floor switch 9 by embedding a switch in the seat surface of the seat.

1 Forklift 2 Vehicle body 3 Mast 4 Fork 5 Operator seat 6 Accelerator lever (speed command means)
7 Drive wheel 8 Brake 9 Floor switch for detection of absence (seating detection unit)
DESCRIPTION OF SYMBOLS 10 Traveling control apparatus 11 Control part 12 Speed detection part 13 Slope detection part 15 Inverter circuit 16 Battery 17 Traveling motor

Claims (3)

In a travel control device comprising speed command means for commanding a target speed, a speed detection unit that detects a vehicle speed, and a control unit that controls a motor for traveling so that the vehicle speed matches the target speed. ,
An absence detection unit that detects whether the operator is away, or
A slope detection unit that detects whether or not the road is a slope,
Further comprising
The control unit sets the target speed to zero when it is detected that the operator is away from the seat and the travel path is a slope, the operator is away from the seat, and the travel When it is detected that the road is not a slope, the travel control device controls the travel motor with the target speed as a predetermined minute speed. The speed detection unit detects the vehicle speed at regular intervals,
The travel control device according to claim 1, wherein the slope detection unit detects that the travel path is a slope when the vehicle speed tends to increase.   An electric vehicle comprising the travel control device according to claim 1.

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