JPH11231937A - Unmanned vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-wheel speed difference type unmanned vehicle capable of stopping without being deviated from a determined traveling locus at the time of emergency stopping. SOLUTION: The unmanned vehicle is constituted of a detection means 1 for detecting the direction of the unmanned vehicle and a control means 2 for controlling the balance of braking of two driving wheels by a prescribed braking means. When the vehicle is turned to right from a required advancing direction e.g. the braking force of the left wheel is increased as compared with that of the right wheel, and when the vehicle is turned to left, the braking force of the right wheel is more increased. When the vehicle is turned to a required advancing direction, the braking force of the right and left wheels is equally controlled. Consequently the unmanned vehicle can be extremely safely stopped without being deviated from the determined traveling locus at the time of emergency stop.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called two-wheel speed difference type unmanned vehicle which performs steering by a speed difference between two drive wheels installed in parallel.

[0002]

2. Description of the Related Art An unmanned vehicle Z of a so-called two-wheel speed difference system in which steering is performed by a speed difference between two drive wheels installed in parallel.
FIG. 4 shows a schematic configuration of a general control system of 0 (see FIG. 3). As shown in FIG. 1, the conventional unmanned vehicle Z0 includes a motor drive unit 32 for driving a left wheel motor 34a and a right wheel motor 34b respectively connected to two left and right drive wheels Wa and Wb, and two left and right drive units. Left wheel brake 35a and right wheel brake 35b connected to wheels Wa and Wb, respectively.
A drive unit 33 for controlling the traveling of the unmanned vehicle Z0 by outputting control signals to the motor drive unit 32 and the brake drive unit 33, and a predetermined emergency stop command. The emergency stop command detecting unit 36 which controls the motor drive unit 32 and the brake drive unit 33 to stop the unmanned vehicle Z0 in an emergency by detecting the
Is provided.

Next, a control procedure of the unmanned vehicle Z0 will be described with reference to FIG. When starting traveling, first, the traveling control unit 31 issues a servo ON command to the motor driving unit 32 (step S31), and issues a brake opening (release) command to the brake driving unit 33. It is issued (step S32). Thereby, the unmanned vehicle Z0 is in a state where it can run. Thereafter, the traveling control is performed until the unmanned vehicle Z0 reaches the target point by giving a speed command, a direction command, and the like to the motor driving unit 32 from the traveling control unit 31 (steps S33 → S34 → S35 → S
33 →…). When the unmanned vehicle Z0 arrives at the target point and the traveling control ends (step S35), the traveling control unit 31 issues a brake closing (operation) command to the brake driving unit 33 (step S36). A servo OFF command is issued to the motor drive unit 32, and the traveling ends (step S37). If an emergency stop button provided on the vehicle body is pressed during traveling of the unmanned vehicle Z0, for example, the emergency stop command detection unit 36 detects the emergency stop command from the emergency stop button (step S1). S3
4) Immediately, a brake closing command is issued to the brake drive unit 33 (step S36), and a servo OFF command is issued to the motor drive unit 32 (step S37).
The vehicle body is suddenly stopped by the frictional force of the brake 37.

[0004]

However, in the above-described emergency stop method, the servo is turned off upon detection of the emergency stop signal, and the braking operation is performed in a state where the direction control of the vehicle body is not performed. There is a possibility that the vehicle body may deviate from the predetermined traveling trajectory until the vehicle stops. In particular, in the case of a two-wheel speed difference type unmanned vehicle such as the above-described unmanned vehicle Z0, the traveling direction is determined only by the speed difference between the left and right two wheels. The direction of travel changes immediately and easily deviates from the trajectory. The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a two-wheel speed difference type unmanned vehicle that can stop without departing from a traveling locus determined at the time of stopping.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is to perform steering by means of a speed difference between two driving wheels installed in parallel, and to perform steering by a predetermined braking means.
In an unmanned vehicle stopped by individually braking the two drive wheels, a detecting means for detecting the direction of the unmanned vehicle and the predetermined braking means based on the direction of the unmanned vehicle obtained by the detecting means A control means for controlling the balance of braking to the two drive wheels is provided as an unmanned vehicle. As the predetermined braking means, for example, a brake is conceivable. If, for example, a brake having a sufficient braking ability cannot be mounted, a means for performing braking by deceleration driving of the drive wheels can be used in the same manner. It is. A situation where the stop control by the control means is required is considered, for example, at the time of an emergency stop in which sudden braking must be performed.

[0006]

According to the unmanned vehicle according to the present invention, for example, at the time of an emergency stop, the balance of braking of the two drive wheels is controlled by the control means based on the direction of the vehicle body detected by the detection means. For example, if the vehicle body is facing right more than the desired traveling direction, the braking force of the left wheel is stronger than that of the right wheel, and if the body is facing left, the braking force of the right wheel is stronger than the left wheel. If it is directed in the traveling direction, control is performed so that the braking forces of the left and right wheels are equal. As a result, it is possible to stop the unmanned vehicle extremely safely during an emergency stop without deviating from a predetermined traveling locus.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments and examples of the present invention will be described below with reference to the accompanying drawings to facilitate understanding of the present invention. The following embodiments and examples are mere examples embodying the present invention, and do not limit the technical scope of the present invention. Here, FIG. 1 is a block diagram illustrating a schematic configuration of a control system of the unmanned vehicle Z1 according to the embodiment of the present invention, FIG. 2 is a flowchart illustrating a control procedure of the unmanned vehicle Z1, and FIG. FIG. 3 is an explanatory diagram showing the arrangement of drive wheels and the definition of a body direction φ. The unmanned vehicle Z1 according to the present embodiment is a two-wheel speed difference type unmanned vehicle in which drive wheels Wa and Wb are arranged in parallel on the left and right sides of the vehicle body as shown in FIG. The speed of the wheels Wa and Wb can be independently controlled, and the direction control of the vehicle body is performed based on the speed difference between the two wheels. FIG. 1 shows a schematic configuration of a control system of the unmanned vehicle Z1. As shown in FIG.
Is a motor drive unit 32 for driving the left wheel motor 34a and the right wheel motor 34b respectively connected to the two left and right drive wheels Wa and Wb, and a body posture detecting unit for detecting the direction of the body (φ shown in FIG. 3). 1 (an example of a detecting means) and a left wheel brake 35a respectively connected to the two left and right drive wheels Wa, Wb based on a deviation between the vehicle body direction obtained by the vehicle body posture detecting section 1 and a desired traveling direction. , A brake switching drive unit 2 (an example of a control unit) for switching the opening and closing of the right wheel brake 35b (an example of a predetermined braking unit), and outputs a control signal to the motor drive unit 32 and the brake switching drive unit 2. Accordingly, the travel control unit 31 that controls the travel of the unmanned vehicle Z1 and the motor drive unit 32 and the brake switching drive unit 2 that control the motor drive unit 32 and the brake switching drive unit 2 by detecting a predetermined emergency stop command. It has and a emergency stop command detecting unit 36 for emergency stop Z1. Various known means such as a gyro can be used as the vehicle body posture detecting section 1.

Next, a control procedure of the unmanned vehicle Z1 will be described with reference to FIG. The traveling control during normal traveling is the same as steps S31 to S35 shown in FIG. 5, and therefore, only the control procedure when an emergency stop command is detected in step S34 in FIG. 5 will be described.
If the emergency stop button provided on the vehicle body is pressed during traveling of the unmanned vehicle Z1, for example, the emergency stop command detecting unit 36 outputs an emergency stop command from the emergency stop button (a predetermined emergency stop command Is detected (step S in FIG. 5).
34) The servo O is immediately applied to the motor drive unit 32.
An FF command is issued (step S1). Then, the following steps S2 to S8 are repeatedly performed until the vehicle body completely stops.

First, the orientation φ of the vehicle body is detected by the vehicle body posture detecting section 1 (step S2). Then, a deviation between the direction φ of the vehicle body and a desired traveling direction (here, a straight traveling direction) is obtained by the brake switching drive unit 2 (step S3). If the deviation is 0, both the left wheel brake 35a and the right wheel brake 35b are closed by the brake switching drive unit 2 (step S4). If the displacement is a positive value, that is, if the vehicle body is displaced leftward from the straight traveling direction, the left wheel brake 35a is opened and the right wheel brake 35b is closed (step S6), and the displacement is negative. In other words, if the vehicle body is displaced rightward from the straight traveling direction, the left wheel brake 35a is closed and the right wheel brake 35b is opened (step S7). By performing the switching control of the left and right brakes as described above, the direction of the vehicle body is corrected so as to approach a desired traveling direction.
That is, the vehicle body always travels along a desired travel locus until it stops. The processing after step S2 is repeatedly performed until the vehicle body completely stops (step S8 → S2
→…). When the vehicle completely stops, the left wheel brake 35a
And the right wheel brake 35b are both closed (step S
9) The emergency stop processing is completed. As explained above,
Even after the emergency stop command is detected and the servo is turned off, the unmanned vehicle Z1 according to the present embodiment is based on the deviation between the vehicle body orientation φ detected by the vehicle body posture detection unit 1 and the desired traveling direction. Since the switching control of opening and closing the left and right brakes is performed so as to correct the direction of the vehicle body in a direction to reduce the deviation, the vehicle can be stopped very safely without deviating from a predetermined traveling locus.

[0010]

In the above embodiment, the simplest straight traveling direction was taken as an example of the desired traveling direction of the vehicle body. However, the present invention is not limited to this. It goes without saying that it is applicable. Also,
In the above embodiment, an unmanned vehicle that uses a brake only at the time of an emergency stop has been described as an example. The opening / closing control can be similarly used at the time of a normal stop. Further, for example, in the case of an unmanned vehicle that is stopped by the deceleration drive of the motor instead of the brake at the time of an emergency stop, the same effect can be obtained by directly replacing the opening and closing control of the left and right brakes with the deceleration control of the left and right motors.

[0011]

As described above, according to the present invention, the steering is performed by the speed difference between two driving wheels installed in parallel, and the two driving wheels are individually braked by predetermined braking means. The detection means for detecting the direction of the unmanned vehicle and the direction of the unmanned vehicle obtained by the detection means are applied to the two drive wheels by the predetermined braking means. Since the vehicle is configured as an unmanned vehicle characterized by including control means for controlling the braking balance, the vehicle can be stopped extremely safely without deviating from a predetermined traveling locus.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a control system of an unmanned vehicle Z1 according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a control procedure of the unmanned vehicle Z1.

FIG. 3 is an explanatory view showing an arrangement of driving wheels of the unmanned vehicle Z1 and a definition of a body direction φ.

FIG. 4 is a block diagram showing a schematic configuration of a control system of a conventional unmanned vehicle Z0.

FIG. 5 is a flowchart showing a control procedure of the unmanned vehicle Z0.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Body attitude | position detection part (an example of a detection means) 2 ... Brake switching drive means (an example of a control means) 35a, 35b ... Brake Wa, Wb ... Drive wheel

Claims (4)

[Claims] 1. An unmanned vehicle in which steering is performed based on a speed difference between two driving wheels installed in parallel and stopped by individually braking the two driving wheels by predetermined braking means. Detection means for detecting the direction of the unmanned vehicle;
Based on the direction of the unmanned vehicle obtained by the detection means,
An unmanned vehicle comprising control means for controlling a balance of braking of the two drive wheels by the predetermined braking means. 2. The unmanned vehicle according to claim 1, wherein said predetermined braking means comprises a brake. 3. The unmanned vehicle according to claim 1, wherein said predetermined braking means performs deceleration driving on said driving wheels. 4. An emergency stop by the stop operation based on a predetermined emergency stop command.
An unmanned vehicle according to any one of claims 1 to 3.