Running command system for unmanned vehicle

• US 4,860,209 A
• Filed: 03/18/1988
• Issued: 08/22/1989
• Est. Priority Date: 11/24/1983
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho (Toyota Motor Corporation)
• Original Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho (Toyota Motor Corporation)
• Inventors: Hongo, Takero, Sugimoto, Gunji
• Primary Examiner(s): Chin, Gary
• Application Number:
  US07/170,313
• Time in Patent Office: 522 Days
• Field of Search: 364/424.02, 364/443, 364/449, 364/457, 364/461, 180/167-169, 318/587, 340/52 F
• US Class Current: 701/25
• CPC Class Codes: G05D 1/0227 using mechanical sensing means, e.g. for sensing treated area
• CPC Class Codes: G05D 1/0255 using acoustic signals, e.g. ultra-sonic singals sonar systems designed for anti-collision purposes G01S15/93
• CPC Class Codes: G05D 1/0272 comprising means for registering the travel distance, e.g. revolutions of wheels measuring distance traversed on the ground by vehicles, e.g. using odometers G01C22/00

Abstract

In a running command system for an unmanned vehicle, path information is stored, a current running state is compared with running command instruction data, an end of an operation corresponding to the running command instruction data is detected, and new running command instruction data corresponding to the next operation is generated upon detection of the end of the operation. The optimal running command instruction data can be set to cause the unmanned vehicle to travel along a running path whose information is stored in a running course memory, thereby accurately guiding the unmanned vehicle to a destination.

Claims

1. A running command system for supplying running command instruction data corresponding to operations including travelling, stopping and turning to a running control unit of an unmanned vehicle to indicate the required operation and the position of the path by which the unmanned vehicle can travel to a destination, said command system comprising:

a position and heading angle measuring means for detecting prevailing running state values including position and heading angle of the unmanned vehicle; and

for generating running state data for leading the unmanned vehicle to the destination;

running course memory means for storing information including a series of paths leading to the destination and the position of each path with reference to a coordinate system;

a running command instruction data creating and setting means connected to the running control unit;

operation end detecting means connected to the position and heading angle measuring means and to the running command instruction data creating and setting means;

(1) for comparing the current position and heading angle information of the running state data generated by the position and heading angle measurement means with the position of the path and an end point thereon given as running command instruction data currently supplied to the running control unit by the running command instruction data creating and setting means, and

(2) for transmitting an operation end signal to the running command instruction data creating and setting means when the result of the comparing operation (1) satisfies terminating conditions which are determined according to the current running command instruction, said operation end signal being transmitted to said running command instruction data creating and setting means before the unmanned vehicle reaches said end point of its current path;

said running command instruction data creating and setting means being connected to said running course memory means and to said operation and detecting means for supplying the running command instruction data for the next operation to the running control unit, upon transmision of the operation end signal by said operation end detecting means to the running command instruction data creating and setting means, in accordance with said information relating the series of paths which is stored in said running course memory means; and

said running control unit performs said next operation after completion of the operation represented by the running command instruction data currently supplied to the running control unit.

2. A system according to claim 1, further comprising running command instruction input means, connected to said running course memory means, to externally input the path information which represents the route up to the destination and which is to be stored in said running course memory means.

3. A system according to claim 1 wherein said running course memory means comprises a running command instruction data memory means for storing the running command instruction data which is supplied to the running control unit and which corresponds to the required operation so as to guide the unmanned vehicle to the destination.

4. A system according to claim 1, wherein said running course memory means comprises:

path group data memory means, connected to said running command instruction data creating and setting means, for storing information of a start point, an end point, and a shape of each of the paths of a course;

position group data memory means, connected to said running command instruction data creating and setting means, for storing coordinate position information representing feature points such as the start and end points of the path; and

running command instruction memory means, connected to said running command instruction data creating and setting means, for storing the path sequence data for guiding the unmanned vehicle to the destination.

5. A system according to claim 1 wherein said operation end detecting means comprises parameter calculation means comprising

stopping distance calculation means for calculating a stopping distance required for stopping the unmanned vehicle by smoothly reducing the velocity of the unmanned vehicle to zero,

position error calculation means for calculating a distance between an end point or a stop point of the path and the current position of the unmanned vehicle, heading error calculation means for calculating a difference between a predetermined heading angle at the stop point and a current heading angle of the unmanned vehicle, and

velocity calculation means for calculating a moving velocity and an azimuth angular velocity, said parameter calculation means effecting calculation from the following data:

the running command instruction data set in the running control unit by the running command instruction data creating and setting means and

the current running state data generated by the position and head measuring means of the unmanned vehicle; and

operation end signal generating means for transmitting the operation end signal to said running command instruction creating and setting means when the values calculated by said parameter calculation means satisfy predetermined conditions so as to make it possible to smoothly execute the next operation.

6. A system according to claim 1 wherein said operation end detecting means comprises:

position error calculating means for calculating a position error l=√

(x_e -y)² +(x-y_e)² representing a distance to the end point in accordance with an end point coordinate position (x_e, y_e) and current position information information (x,y) of the unmanned vehicle when the operation set by said running command instruction data creating and setting means represents traveling;

stopping distance calculating means for calculating a stopping distance L=k_v ·

v² in accordance with moving velocity information v, and the value k_v is predetermined according to characteristics of the drive unit of the unmanned vehicle;

and path travel end detecting means for comparing the position error l and the stopping distance L and for generating an operation end signal when the position error l is smaller than the stopping distance L.

7. A system according to claim 1 wherein said operation end detecting means comprises:

absolute value calculating means for calculating an absolute value |v| of moving velocity and an absolute value |ω

| of azimuth angular velocity of the unmanned vehicle when the operation set by said running command instruction data creating and setting means represents turning;

and turning end detecting means connected to said absolute value calculating means and said running command instruction data creating and setting means for (1) comparing the absolute values calculated by said absolute value calculating means with predetermined threshold values Vc and Ω

c, respectively, (2) comparing an error between the predetermined heading and the current heading angle of the unmanned vehicle with a predetermined value θ

c when the absolute values are smaller than the predetermined values Vc and Ω

c, and (3) transmitting an operation end signal to said running command instruction data creating and setting means when the error is smaller than said predetermined value θ

c.

8. A system according to claim 1, wherein said operation end detecting means comprises:

position error calculating means for calculating a position error l representing a distance up to the end point when the operation set by said running command instruction data creating/setting means represents stopping; and

stopping end detecting means for comparing the position error l with a predetermined value Lc, comparing absolute values |v| and |ω

| of moving and azimuth angular velocities with predetermined values Vc and Ω

c when the position error l is smaller than the predetermined value Lc, and generating an operation end signal when the absolute values |v| and |ω

| are smaller than the predetermined values Vc and Ω

c.

9. A system according to claim 1 further comprising a start switch connected to said operation end detecting means and to a brake of the unmanned vehicle for being in ON state by manual operation and for being in OFF state when said brake comes ON, and

wherein said operation end detecting means comprises:

position error calculating means for calculating a position error l=√

(x_e -y)² +(x-y_e)² representing a distance up to the end point when the operation set by said running command instruction data creating and setting means represents stopping; and

temporary stopping end detecting means for comparing the position error l with a predetermined value Lc, comparing absolute values of |V| and |ω

| representing linear and angular velocities respectively with predetermined values Vc and Ω

c when the position error l is smaller than the predetermined value Lc, comparing an error θ

-θ

_e between the heading angle θ

_e obtained from current running command instruction data and a current heading angle θ

of the unmanned vehicle with a predetermined value Ω

c when the absolute values |V| and |ω

| are smaller than the predetermined values V_c and Ω

c, generating a brake ON signal to cause the start switch to turn off, when the error is smaller than the predetermined value Lc, and transmitting an operating end signal to said running command instruction creating and setting means when the start switch is switched to ON state.

10. A system according to claim 4 wherein said running command instruction data creating and setting means comprises running command instruction data creating means connected to said running command instruction memory means, said position group data memory means and said path group data memory means for creating running command instruction data representing a coordinate position, a path shape and an operation of the unmanned vehicle in accordance with the running command instruction stored in said running command instruction memory means and coordinate position data of a point stored in said position group data memory means, and data of a start point, an end point, a radius of curvature representing a path type, and a center of the radius of curvature of the path stored in said path group data memory means.

11. A system according to claim 1, further comprising:

abnormality detecting means for detecting an abnormal state in which the unmanned vehicle is not properly driven along the preset running path; and

running command instruction data generating means, connected to said abnormality detecting means and said running command instruction data creating and setting means, for generating new running command instruction data upon detection of the abnormal state by said abnormality detecting means in accordance with predetermined procedures using running state information of the unmanned vehicle and the running command instruction data currently supplied to the running control unit.

12. A system according to claim 11, wherein said abnormality detecting means includes obstacle detecting means for detecting an obstacle located on the running path, and said running command instruction data generating means generates the running command instruction data representing slowdown or stopping upon detection of the obstacle by said obstacle detecting means.

13. A system according to claim 11, wherein said abnormality detecting means includes transmitting means including pushbutton switches connected to said running command instruction data generating means to temporarily slow down or stop the unmanned vehicle based on the running command instruction data representing slowdown or stopping in accordance with the state of said switches.

14. A system according to claim 11, wherein said abnormality detecting means includes power level detecting means connected to said running command instruction data generating means for transmitting a signal to said running command instruction data generating means when the current power level of a power source of the unmanned vehicle becomes less than a predetermined value.

15. A system according to claim 11, wherein said abnormality detecting means includes

an obstacle sensor connected to said running command instruction data generating means and to the brake of the unmanned vehicle for transmitting a signal to the brake of the unmanned vehicle to stop the unmanned vehicle and for transmitting an emergency signal to said running command instruction data generating means when the unmanned vehicle approaches or contacts an obstacle, and

an emergency stop switch connected to said running command instruction data generating means and to the brake of the unmanned vehicle for transmitting a signal to the brake of the unmanned vehicle to stop the unmanned vehicle and for transmitting an emergency signal to effect an emergency stop to said running command instruction data generating means when manually instructed to urgently stop;

and

said running command instruction data generating means comprises;

means for monitoring said obstacle sensor and said emergency stop switch and for generating the emergency stop signal according to a predetermined condition,

means for generating emergency stop instruction data to actuate the brake of the unmanned vehicle when said monitoring means detects that the unmanned vehicle is to be urgently stopped, and

means, responsive to the position and heading angle information of the unmanned vehicle, for generating running command instruction data representing temporary stopping, the current position and the heading angle, for generating an abnormality end signal.

16. A system according to claim 11, wherein said abnormality detecting means includes

an obstacle sensor connected to said running command instruction data generating means for transmitting a signal when the unmanned vehicle is at a predtermined distance from an obstacle,

a power level sensor connected to said running command instruction data generating means and to the power source of the unmanned vehicle for transmitting a signal to said running command instruction data generating means when the present power level of the power source becomes lower than a predetermined value,

and a temporary stop switch connected to said running command instruction data generating means for transmitting a signal to said running command instruction data generating means when manually instructed to effect a temporary stop;

and

said running command instruction data generating means further comprises;

means for monitoring said obstacle sensor and said temporary stop switch and for detecting whether or not the unmanned vehicle is to be temporarily stopped,

means for storing the position and heading angle information of the unmanned vehicle, the stopping distance calculated by said operation end detecting means, and the running command instruction data set in said running control unit when said monitoring means detects that the unmanned vehicle is to be temporarily stopped,

means for detecting whether or not the operation of the running command instruction data represents traveling;

means for generating new running command instruction data whose operation represents temporary stopping and for generating an abnormality end signal when the operation does not represent traveling, and

means for generating new running command instruction data when the operation thereof represents temporary stopping, the end position represents a position ahead of the current position by the stopping distance, and the heading angle represents the current heading angle, and for generating the abnormality end signal when the operation represents traveling.

17. A system according to claim 11, wherein said abnormality detecting means comprises

a slowdown sensor connected to said running command instruction data generating means for detecting the presence of an obstacle, and for transmitting a signal to said running command instruction data generating means when the obstacle is detected,

and a slowdown switch connected to said running command instruction data generating instruction data generating means when an operator manually instructs the unmanned vehicle to slowdown;

and

said running command instruction data generating means further comprises;

means for monitoring said slowdown sensor and said slowdown switch and for detecting whether or not the unmanned vehicle is to be slowed down;

means for detecting whether or not the running command instruction data curently set in said running control unit of the unmanned vehicle represents running when said monitoring means detects that the unmanned vehicle is to be slowed down, and

means for immediately generating an abnormality end signal when the set data does not represent running and for generating new running command instruction data when the value of moving velocity, supplied by the running command instruction data creating and setting means, represents a low velocity and generating the abnormality end signal when the set data represents running.

18. A system according to claim 11, wherein said running command instruction data creating and setting means comprises:

means for detecting whether or not the abnormality end signal is generated from said running command instruction data generating means;

means for temporarily saving the running command instruction data curently set in the running control unit and for setting the running command instruction data from the running command instruction data generating means in said running control unit when the abnormality end signal is generated;

means for detecting whether or not the operation end signal is generated from said operation end detecting means when the abnormality end signal is not generated;

means for detecting whether or not the saved running command instruction data has been temporarily saved when the abnormality end signal is generated; and

means for setting the saved running command instruction data in said running control unit when the saved running command instruction data is detected to be saved, and for setting the running command instruction data from said running command instruction data creating and setting means, for creating running command instruction data representing a coordinate position, a path shape and an operation of the unmanned vehicle in accordance with the running command instruction stored in said running course memory means, when the saved running command instruction data is detected not to be saved.

19. A system according to claim 4, further comprising:

abnormality detecting means for detecting an abnormal state wherein the unmanned vehicle is not properly driven along the preset running path; and

running command instruction data generating means, connected to said abnormality detecting means and said running command instruction data creating and setting means, for generating new running command instruction data upon detection of the abnormal state by said abnormality detecting means in accordance with predetermined procedures using running state information of the unmanned vehicle and the running command instruction data currently supplied to the running control unit.