WO1997031302A1

WO1997031302A1 - Method and apparatus for controlling travel of unmanned vehicle

Info

Publication number: WO1997031302A1
Application number: PCT/JP1997/000450
Authority: WO
Inventors: Tsugio Sudo; Yukio Okawa
Original assignee: Komatsu Ltd.
Priority date: 1996-02-20
Filing date: 1997-02-19
Publication date: 1997-08-28
Also published as: AU1733197A; JPH09230939A

Abstract

A sudden stop due to off-course during automatic traveling is prevented, and travel safety and travel locus precision are ensured. When the deviation (δ) of the present position from a target position is greater than a predetermined threshold value (α) at the time of automatic traveling on a course (6), at least one of the following controls is performed: the operation of decreasing the prescribed vehicle speed to control the vehicle speed and the operation of altering the steering control gain to control the steering.

Description

Description Travel control method and device for unmanned vehicles

The present invention relates to a travel control method and apparatus for controlling a travel locus of an unmanned vehicle during automatic travel. Background technology

Conventionally, there have been many proposals for an unmanned vehicle traveling system capable of unmanned traveling of a vehicle along a predetermined traveling course. At quarry sites in a wide area, an unmanned dump truck operation system that transports sediment using unmanned vehicles, for example, unmanned dump trucks, is well known. This unmanned dump truck operation system is, for example, as follows. The running course of the unmanned dump truck is taught in advance by a predetermined method, and coordinate data at a predetermined distance or time on the running course is stored as running course data in a storage device. At the time of automatic traveling, the unmanned dump truck detects and confirms the current position where the vehicle is actually traveling by the position detecting means at every predetermined sampling time, and checks the actual traveling position and the previously stored traveling course data. Is calculated. Then, the steering control of the unmanned dump is performed so as to reduce the deviation, and the unmanned dump is controlled so as to travel along the traveling course stored in advance.

The vehicle speed during automatic driving is determined by the engine fuel injection amount so as to reduce the deviation between the prescribed vehicle speed value predetermined for each section of the traveling course and the actual vehicle speed detected by the vehicle speed detecting means. This is done by controlling the transmission and brakes. The vehicle speed detecting means detects the vehicle speed based on, for example, the number of revolutions of the drive wheel shaft per unit time.

If the deviation between the target position and the actual position of the traveling course, that is, the amount of displacement, exceeds the allowable value during automatic driving, the driver is usually forced to use an unmanned vehicle to ensure safety. It is often stopped by applying a brake. However, if sudden braking is applied during high-speed driving, the running stability of unmanned vehicles is impaired, and vehicle slipping may occur. Therefore, the vehicle speed is limited to a low specified value so that stability is not impaired even when sudden braking is applied. Alternatively, when the specified vehicle speed value is large, the allowable value of the displacement amount is reduced so that even if the braking distance is large, contact with another vehicle does not occur. For this reason, if the vehicle speed is restricted to a slower specified vehicle speed, the number of workers per unit time of the unmanned vehicle is limited and the efficiency is reduced, or if the tolerance of the displacement is reduced, the course out The frequency of sudden stops due to (position deviation exceeding the allowable value) is likely to increase. That is, there is a problem that the operation rate of the unmanned vehicle decreases. Disclosure of the invention

The present invention has been made in order to solve the problems of the related art, and suppresses the occurrence of sudden stop due to a course during automatic driving, and furthermore, does not reduce the work efficiency, and provides the driving safety and safety. It is an object of the present invention to provide an unmanned vehicle traveling control method and device capable of securing traveling trajectory accuracy.

A first traveling control method for an unmanned vehicle according to the present invention includes:

When the vehicle automatically travels on the traveling course, a steering angle command is output to reduce the amount of displacement between the target position and the current position, and the steering angle command is compared with the steering angle of the steering handle to determine the steering angle deviation. In the traveling control method for an unmanned vehicle, the steering is controlled based on the steering angle deviation and the steering control gain, and the speed is controlled so as to travel at a specified vehicle speed.

When the amount of displacement is equal to or greater than a predetermined threshold, speed control is performed by increasing the specified vehicle speed value, and at least one control of steering control by changing the steering control gain is performed. It is a feature.

According to such a configuration, when the positional deviation amount becomes equal to or more than the predetermined threshold value, the positional deviation amount tends to increase. Therefore, the vehicle speed is reduced, and the steering control gain is changed. When decelerating, it is easy to correct the running direction before the course The followability of the direction control is improved. In addition, the steering control gain is changed to improve steering responsiveness and improve travel trajectory accuracy. As a result, the traveling direction is corrected before the course out so that the positional deviation amount becomes small. As a result, the sudden stop of the unmanned vehicle due to the course is eliminated, so that the work efficiency is improved, and the traveling trajectory accuracy is improved, and the traveling safety is improved.

In the second traveling control method for an unmanned vehicle according to the present invention, when the amount of displacement is increasing, speed control is performed by reducing a prescribed vehicle speed value, and steering control is performed by changing a steering control gain. It is characterized by performing at least one control. According to this configuration, as in the first method, the deceleration reduces the followability of the traveling direction control, and the steering response gain is improved by changing the steering control gain to improve the traveling response. Is also good. In addition, since it is determined whether or not the amount of positional deviation is increasing, the traveling direction is corrected earlier before the amount of positional deviation becomes larger than judgment based on the amount of positional deviation. Becomes possible. Therefore, the traveling direction is corrected before the course leaves. As a result, as in the case of the first method, work efficiency and traveling safety are improved.

The first unmanned vehicle travel control device according to the present invention is

A controller that calculates target position data on the traveling course that automatically travels, and outputs a steering command that reduces the amount of displacement between the target position data and the current position data, and a controller that outputs the steering command and steering handle. A steering control unit for controlling the steering based on the steering angle deviation and the steering control gain to obtain a steering angle deviation by comparing the steering angle with the steering angle.

The controller outputs a command to change the steering control gain to the steering control means when the amount of displacement is equal to or greater than a predetermined threshold.

According to such a configuration, when the positional deviation amount becomes equal to or more than the predetermined threshold value, the positional deviation amount tends to increase, so that the steering control gain of the steering control means is changed. As a result, as in the above, the steering response is improved, and the traveling trajectory accuracy is improved.

The running direction is corrected before the course leaves. As a result, similar to the first method, The work efficiency and running safety are improved.

The traveling control device for a second unmanned vehicle according to the present invention,

Calculates target position data on the traveling course for automatic driving, outputs a steering command to reduce the amount of displacement between the target position data and the current position data, and issues a speed command so that the vehicle speed becomes the specified vehicle speed value. The controller that outputs the output, the speed control means that controls so as to reduce the vehicle speed deviation between the speed command and the actual vehicle speed, and the steering angle deviation by comparing the steering command with the steering angle of the steering handle And a steering control means for controlling the steering based on the steering angle deviation and the steering control gain.

The controller outputs at least one of an output of a deceleration command to the speed control means and an output of a change command of the steering control gain to the steering control means when the displacement amount is equal to or more than a predetermined threshold value. It is characterized by performing

This configuration is a configuration in which the first method is expressed as an apparatus, and the same operation and effect as those of the first method can be obtained. When the vehicle speed is reduced and the steering control gain is changed at the same time, the traveling direction is corrected so that the displacement becomes smaller in a shorter time. As a result, unmanned vehicles will not have a sudden stop due to course out, or will have a very low frequency of sudden stops. As a result, work efficiency is further improved, and traveling trajectory accuracy is also improved, thereby improving traveling safety. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a control configuration block diagram of the travel control device for an unmanned vehicle according to the present invention. FIG. 2 is an explanatory diagram of the operation of the travel control device for an unmanned vehicle according to the present invention.

FIG. 3 is a processing flowchart of the travel control device for an unmanned vehicle according to the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings.

In FIG. 1, the position detecting means 1 2 automatically moves the unmanned vehicle 1 (see FIG. 2). The current position in the traveling coordinate system representing the area is detected, and this position data is output to the controller 11. As the position detecting means 12, for example, a means for detecting an absolute coordinate position by a GPS system or the like is used. Alternatively, the position detecting means 12 may use a known reference based on the traveling direction data (angle data) detected by the ji mouth or the like and the traveling distance data detected by the rotation speed of the driving wheels or the like. A coordinate position relative to the position may be obtained by calculation. The traveling course data storage means 20 stores position data of each point on a predetermined traveling course at a predetermined distance and a prescribed vehicle speed value for each predetermined section of the traveling course. The position data is stored as coordinate data in the traveling coordinate system.

The controller 11 is composed of a general computer system mainly composed of, for example, a micro computer. The controller 11 calculates coordinate data of a traveling target position at predetermined time intervals based on each position data stored in the traveling course data storage means 20 during automatic traveling. Then, the controller 11 calculates the speed command V and the steering fingering 0 of the steering handle so as to travel toward the traveling target position. That is, the controller 11 calculates the traveling direction and the traveling distance based on the current position data input from the position detecting means 12 and the coordinate data of the traveling target position at the predetermined time intervals.

Then, a steering instruction 0 for directing the unmanned vehicle 1 in the traveling direction is calculated, and a steering command 0 is output to the steering control means 14. Further, it outputs a speed command V to the speed control means 13 based on the prescribed vehicle speed value stored in the traveling course data storage means 20. After completing the travel based on the calculated travel distance data, the current position data is input, the same processing as above is performed, and the steering finger 0 and the speed command V are calculated and output. By repeating such processing, the unmanned vehicle 1 can automatically travel along the traveling course.

The vehicle speed detector 16 detects the actual vehicle speed of the unmanned vehicle 1, and outputs a vehicle speed signal corresponding to this vehicle speed. The vehicle speed detector 16 counts, for example, the number of pulses output from a pulse generator mounted on the axle of the drive wheel for each unit time. It is configured to calculate the vehicle speed value from the vehicle. The speed control means 13 compares the speed command V from the controller 11 with the vehicle speed signal from the vehicle speed detector 16 so that this deviation (hereinafter referred to as the speed deviation) becomes smaller. In addition, the vehicle speed is controlled by performing at least one of engine fuel injection amount control, transmission control, and brake braking control.

The steering angle detector 17 detects the steering angle of the steering handle, and is composed of, for example, a potentiometer. This steering angle signal is input to the steering control means 14. The steering control means 14 compares the steering command S from the controller 11 with the steering angle signal, and adjusts the steering angle (not shown) so as to reduce this deviation (hereinafter referred to as steering angle deviation). Outputs a drive command in the drive mode and rotates the steering handle. At this time, the steering control means 14 calculates a drive command value to the steering drive mode based on the steering angle deviation and the steering control gain. For example, the steering control gain is calculated based on the steering angle deviation value. The driving order value can be obtained by multiplication.

Note that the speed control means 13 and the steering control means 14 are configured by a general computer system like the controller 1. Therefore, the controller 11, the speed control means 13 and the steering control means 14 can be constituted by a single computer system, which is more cost-effective.

The operation of the travel control device will be described with reference to FIG. It is assumed that the unmanned vehicle 1 travels automatically along a predetermined traveling course 6. Further, it is assumed that the position coordinate data (X k, Y k) of each point on the traveling course 6 at every predetermined distance is stored in the traveling course data storage means 20. Where K is a natural number. When the vehicle automatically travels between the position coordinate data (Xk-1, Yk-1) and (Xk, Yk) in which the unmanned vehicle 1 is stored, the controller 11 travels during this time. 6 The coordinates (X m, Y m) of the coordinates of the target position of the automatic driving for each predetermined distance are calculated and obtained. After the calculation, the controller 11 performs the steering control and the vehicle speed control with the coordinate data (Xm, Ym) as a target.

At this time, the actual traveling position (X n, Y n) of the unmanned vehicle 1 is equal to the target position (X m. Ym), and the displacement S occurs. When a displacement δ exceeding the predetermined limit value 3 with respect to the traveling course 6 occurs, it is dangerous in terms of traveling safety, and the vehicle is suddenly stopped as a course out. Furthermore, a threshold value α that is smaller than the limit value is set, and when a displacement amount <5 that exceeds the threshold value α occurs, the response of the steering control and the follow-up of the vehicle speed control are performed in order to correct the traveling direction. We try to improve the quality. Some of the thresholds may be provided in stages so that the degree of the improvement can be changed according to the magnitude of the positional deviation amount 5. For example, as shown in FIG. 2, the threshold value α may be set in two stages, α 1 and α 2. Here, 0 <α1 <α2.

The operation will be described with reference to the traveling control processing flowchart of FIG. 3 and FIG. Here, the above-described threshold α is provided as an example. In addition, the step code of FIG. 3, for example, S1, is the power which is Step 1, and is described below simply as (S1) or S1.

(S 1) The position detection means 12 calculates the current position (Χη, Υη) by calculation and outputs this to the controller 11.

(S 2) The controller 11 calculates the displacement amount () based on the target position (Xm, Yin) and the current position (Χη, Υη) on the traveling course 6. obtained as a. first, a target position (Xm. Ym) and the current position (Kaiita, Yn) the distance between the L (see FIG. 2), the formula ^{"L = [(Δ Xm) 2} + (Δ Ym) 2 ^/ Πι-Xm-Xn, ΔYm = Υm — Υη. Then, based on the distance L and the traveling direction angle f of the unmanned vehicle 1, the current The position deviation amount δ of the position (Χπ, Yn) with respect to the traveling course 6 is obtained.

(S3) The controller 11 determines whether or not the positional deviation amount (5 is equal to or greater than a predetermined threshold value α). If the positional deviation amount δ is equal to or greater than the threshold value, the process proceeds to S4. Proceed to.

(S 4) The controller 11 outputs a speed command V smaller than the current vehicle speed value to the speed control means 13 to reduce the speed, or sends the current steering control gain to the steering control means 14. Either output a command to change, or do at least one of them. (S5) When the speed command V is input, the speed control means 13 performs speed control based on the speed command V. Further, when a steering control gain change command is input, the steering control means 14 switches to a steering control gain corresponding to the command, and performs steering control based on the steering control gain. Then, the process returns to S 1 and repeats the process.

(S6) The controller 11 outputs a speed command V for setting a normal vehicle speed value to the speed control means 13 and issues a command for setting the normal steering control gain to the steering control means 14. Power.

(S7) The speed control means 13 performs speed control so as to be a normal vehicle speed value. The steering control means 14 performs the steering control with a normal steering control gain. Then, the process returns to S 1 to repeat the processing.

In the above flow chart, when a plurality of thresholds α are provided stepwise, the following is performed. For example, as shown in FIG. 2, when the threshold α is set to α 1 and α 2 (a 1 <α 2), in the above S 3, the controller 11 has a position shift amount <5 Judge either 0 <(5 ≤ a1), "al <δ ≤ α2", or "α2 <5". When "l <5 ≤ hi2" In the above S4, the speed command V is set to VI or the steering control gain is set to G1 and the speed command V is set to “α2 α5”. At least one of the force of V 2 and the steering control gain of G 2 is performed, where V 2 <V 1 and the normal vehicle speed value. As the control gain, for example, G2> G1> normal steering control gain is used.

As described above, when the positional deviation amount δ becomes larger than the predetermined threshold value, the deceleration force or the steering control gain is changed, and at least one of them is performed.

. By reducing the speed, the increase in the displacement δ is suppressed, and the traveling direction can be easily corrected before the displacement δ reaches the limit value / 3. Therefore, the followability of the traveling direction control is improved, and the course does not go out. In addition, the steering control gain is changed to improve the response of the steering control. As a result, the accuracy of the travel trajectory is improved and the displacement Since δ becomes small, the course does not go out. As a result, traveling trajectory accuracy and traveling safety can be ensured, and the operation rate of the unmanned vehicle 1 can be improved.

In the above description, the speed and the steering control gain are switched based on the magnitude of the positional deviation amount 5, but the present invention is not limited to this. For example, the switching is performed according to the increasing tendency of the positional deviation amount 5. You may. At this time, in S3 of the flowchart, the controller 11 determines the amount of misalignment (whether or not 5 is increasing), and if it is increasing, proceeds to S4 and proceeds to S4. This can be handled by performing the same processing.

INDUSTRIAL APPLICABILITY The present invention is useful as a traveling control method and apparatus for an unmanned vehicle that can suppress the occurrence of sudden stop due to a course out during automatic traveling and can secure traveling safety and traveling locus accuracy without lowering work efficiency. is there.

Claims

The scope of the claims

1. When the vehicle automatically travels on the traveling course (6), a steering angle command for reducing the amount of displacement between the target position and the current position is output, and the steering angle command and the steering angle of the steering handle are output. A steering angle deviation is calculated by comparing the steering angle deviation and the steering control gain, and a traveling control method for an unmanned vehicle that performs speed control so as to travel at a specified vehicle speed value.

When the displacement amount (5) is equal to or greater than a predetermined threshold value (h), it is necessary to decelerate the specified vehicle speed value to perform speed control, and to change the steering control gain to perform steering control. A traveling control method for an unmanned vehicle, characterized by performing one type of control.

2. When automatically traveling on the traveling course (6), a steering angle command for reducing the amount of displacement between the target position and the current position is output, and the steering angle command and the steering angle of the steering handle are compared. Determining a steering angle deviation by comparison, performing steering control based on the steering angle deviation and the steering control gain, and controlling the speed so that the vehicle runs at a specified vehicle speed value.

When the displacement amount (<?) Is increasing, the vehicle speed is controlled by decelerating the specified vehicle speed value, and the steering control is performed by changing the steering control gain. A driving control method for an unmanned vehicle, comprising:

3. A controller that calculates target position data on the traveling course (6) for automatic driving, and outputs a steering command to reduce the positional deviation between the target position data and the current position data. A steering control means for comparing the steering command with the steering angle of a steering handle to obtain a steering angle deviation, and controlling steering based on the steering angle deviation and a steering control gain (14). In a travel control device for an unmanned vehicle comprising:

The controller (11) outputs a command to change the steering control gain to the steering control means (14) when the displacement (5) is equal to or larger than a predetermined threshold (α). thing A travel control device for an unmanned vehicle.

4. Calculate the target position data on the automatic course (6), output a steering command to reduce the amount of displacement between the target position data and the current position data, and set the vehicle speed to the specified vehicle speed value. And a speed control means (13) for controlling so as to reduce a vehicle speed deviation between the speed command and the actual vehicle speed.

A steering control means for comparing the steering command with a steering angle of a steering handle to determine a steering angle deviation, and controlling steering based on the steering angle deviation and a steering control gain. In the travel control device,

The controller (11) outputs a deceleration command to the speed control means (13) when the displacement amount (δ) is equal to or larger than a predetermined threshold value (h), and outputs the steering control means ( 14. A travel control device for an unmanned vehicle, characterized in that at least one of the outputs of the steering control gain change command to (14) is output.