Method of guiding an unmanned vehicle

• US 4,866,617 A
• Filed: 03/25/1987
• Issued: 09/12/1989
• Est. Priority Date: 07/11/1986
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Komatsu Seisakusho
• Original Assignee: Kabushiki Kaisha Komatsu Seisakusho
• Inventors: Yoshikawa, Eiji, Nishi, Yohkichi, Hosoi, Mitsuo, Matsuda, Tomoo
• Primary Examiner(s): Lall, Parshotam S.
• Assistant Examiner(s): Black, Thomas G.
• Application Number:
  US07/030,193
• Time in Patent Office: 902 Days
• Field of Search: 364/424, 364/426, 364/424.02, 368/103, 318/587, 901/1, 901/67, 180/167, 180/168, 180/169
• US Class Current: 701/25
• CPC Class Codes: G05D 1/0246 using a video camera in combination with image processing means
• CPC Class Codes: G05D 1/0261 using magnetic plots
• CPC Class Codes: G05D 1/0263 using magnetic strips
• CPC Class Codes: G05D 1/0265 using buried wires
• CPC Class Codes: G05D 1/027 comprising intertial navigation means, e.g. azimuth detector inertial navigation G01C21/16; inertial navigation combined with non-inertial navigation instruments G01C21/165
• 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
• CPC Class Codes: G05D 1/0282 generated in a local control room
• CPC Class Codes: G05D 2201/0216 Vehicle for transporting goods in a warehouse, factory or similar

Abstract

A method of an unmanned vehicle comprises the steps of placing a certain number of ground marks each of which comprises a plurality of line segments on a passage of the vehicle measuring amount of movement of the vehicle between the adjacent line segments when the vehicle moves across each of the ground marks, and obtaining a relative positional relation between the ground mark and the vehicle with reference to the amount of movement thereof whereby movement of the vehicle is properly guided in accordance with the thus obtained positional relation. In the case of a navigational guiding method typically employed in aircraft or ship, an estimated position of the vehicle is corrected with reference to the aforesaid relative positional relation.

Claims

1. A method of guiding an unmanned vehicle comprising the steps of;

placing a ground mark comprising first, second and third line segments in such a manner that they extend in the transverse direction relative to a passage of said unmanned vehicle, said first and second line segments being in parallel with one another and said third line segment being located between the first and second line segments and extending in the non-parallel relation relative to them,

mounting line segment detecting means on the unmanned vehicle,

measuring the amount of movement of the vehicle from the time when the first line segment is detected by said line segment detecting means to the time when the third line segment is detected as well as the amount of movement of the vehicle from the time when the third line segment is detected to the time when the second line segment is detected,

obtaining a relative positional relation between the ground mark and the vehicle with reference to each of said measured distances, and

carrying out guiding of the vehicle in accordance with said relative positional relation.

2. A method of guiding an unmanned vehicle as claimed in claim 1, wherein each of the amounts of movement is measured with reference to time required for movement of the vehicle by each of the distances in the case where a moving speed of the vehicle is kept constant.

3. A method of guiding an unmanned vehicle as claimed in claim 1, wherein said line segment detecting means is accommodated within the hollow space in one of the wheels for the vehicle.

4. A method of guiding an unmanned vehicle comprising the steps of;

placing at least a ground mark comprising first, second, third and fourth line segments in such a manner they extent in the transverse direction relative to a moving passage of said unmanned vehicle, said first and second line segments being in parallel with one another and at least one of said third and fourth line segments being located between the first and second line segments and extending in the non-parallel relation relative to them,

mounting a single line segment detecting means on the unmanned vehicle,

measuring each amount of movement of the vehicle between successive time points at which said line segment detecting means successively detects each of the line segments,

obtaining a relative positional relation between the ground mark and the vehicle with reference to each of thus measured amount, and

carrying out guiding of the vehicle in accordance with said relative positional relation.

5. A method of guiding an unmanned vehicle as claimed in claim 4, wherein said line segment detecting means is accommodated within the hollow space in one of the wheels for the vehicle.

6. A method of guiding an unmanned vehicle provided with a means for measuring a current position of the vehicle, comprising the steps of:

preparing a plurality of ground marks having a shape for enabling the vehicle to detect relative positions of the vehicle with respect to the ground marks;

disposing the ground marks at a plurality of predetermined locations within a vehicle moving area;

storing positions of the ground marks in the form of coordinates of a coordinate system into a memory;

selecting some of the ground marks and assigning orders to the selected ground marks one after another so as to designate a passage for the vehicle;

obtaining a plurality of ground points between each of adjacent two of the selected ground marks by interpolation, and storing coordinates of the ground points in the coordinate system into the memory;

teaching the passage to the vehicle by using the ground points;

guiding the vehicle along the passage with reference to the current position of the vehicle measured by the vehicle and target points comprising the ground marks and ground points;

detecting the relative position of the vehicle with respect to the ground marks by the vehicle each time the vehicle passes the ground marks; and

correcting the current position of the vehicle measured by the vehicle on the relative position.

7. A method of guiding an unmanned vehicle as claimed in claim 6, wherein the marks have certain directionality.

8. A method of guiding an unmanned vehicle as claimed in claim 7, wherein said interpolation is selectively effected in the form of linear interpolation or arch interpolation and in the case where among the selected ground marks the adjacent two ground marks have the same directionality, linear interpolation is effected therebetween, while in the case where the adjacent two ground marks have different directionality, arch interpolation is effected therebetween.

9. A method of guiding an unmanned vehicle as claimed in claim 8, wherein the position of the ground marks estimated on the vehicle side is obtained with reference to the direction and amount of movement of the vehicle.

10. A method of guiding an unmanned vehicle as claimed in claim 6, wherein the position of the vehicle is measured by the vehicle with reference to the direction and amount of movement of the vehicle.

11. A method of guiding an unmanned vehicle wherein a plurality of ground marks having plural linear line segments arranged in a predetermined geometrical relation are placed on a passage of said vehicle, each of successive time points at which the vehicle moves across each of said line segments is detected in response to the output from a line segment detecting means mounted on the vehicle, a relative positional relation between the ground marks and the vehicle is obtained from the amount of movement of the vehicle at the successive time points at which the vehicle moves across the ground marks, and guiding of the vehicle is effected in accordance with the aforesaid positional relation, comprising the steps of;

measuring amount of movement of the vehicle at each of the successive time points at which said line segment detecting means moves toward and away from the line segments by making a comparison between detection output from the line segment detecting means and a predetermined threshold, and

obtaining amount of movement of the vehicle at each of the successive time points at which the line segment detecting means moves past the center position of the line segments by obtaining an average value among amount of movement of the vehicle.

12. A method of guiding an unmanned vehicle provided with a means for measuring a current position of the vehicle wherein a passage of the vehicle is taught to the vehicle in the form of a series of target points on the passage and the vehicle is guided along the passage with reference to a current target point among the target points and a current position of the vehicle is measured by the vehicle, said method comprising the steps of:

obtaining a distance between the position of the current target point and the current vehicle position measured by the measuring means provided on the vehicle; and

setting another target point located next to the current target point as a new target point when said distance becomes shorter than a predetermined distance or increases as the vehicle moves on.

13. A method of guiding an unmanned vehicle as claimed in claim 12, wherein a distance between the adjacent ground points is determined in the range of 1/50 to 4 times of the minimum turning radius with which the vehicle does not slide in the lateral direction.

14. A method of guiding an unmanned vehicle as claimed in claim 12, wherein teaching is effected with respect to said series of ground points in such a manner that a radius of a circle as defined by the adjacent three ground points is determined larger than the minimum turning radius.

15. A method of guiding movement of an unmanned vehicle as claimed in claim 12, wherein said predetermined distance is a distance which is considered as a fact that the vehicle has reached the current target point.

16. A method of guiding an unmanned vehicle comprising the steps of;

placing at least a ground mark comprising first and second line segments in such a manner that they extend in the transverse direction relative to a moving passage of said unmanned vehicle, said first and second line segments extending in the non-parallel relation,

mounting two line segment detecting means on the vehicle with a predetermined distance kept between the adjacent ones in the direction of width of the vehicle,

measuring as first distance a distance of movement of the vehicle from the time when either of said two line segment detecting means detects either of the line segments to the time when the other line segment detecting means detects the same line segment,

measuring as second distance a distance of movement of the vehicle from the time when either one of said two line segment detecting means detects the first line segment to the time when it detects the second line segment,

obtaining a relative positional relation between the ground mark and the vehicle with reference to said first and second distances, and

carrying out guiding of movement of the vehicle in accordance with said relative positional relation.

17. A method of guiding an unmanned vehicle as claimed in claim 16, wherein said line segment detecting means is accommodated within the hollow space in one of the wheels for the vehicle.

18. A method of guiding an unmanned vehicle provided with a means for measuring a current position of the vehicle, comprising the steps of:

preparing a plurality of ground marks having a shape for enabling the vehicle to detect relative positions of the vehicle with respect to the ground marks;

disposing the ground marks at a plurality of predetermined locations within a vehicle moving area;

determining a passage for the vehicle by manually running the vehicle such that the vehicle selectively passes some of the ground marks;

measuring by the vehicle the positions of the vehicle at a plurality of locations between each of the two adjacent ground marks while the vehicle runs along the passage thus determined, and storing the vehicle positions thus measured into a memory as the positions of the ground points;

teaching the passage to the vehicle by using the ground points;

guiding the vehicle along the passage by using the current position of the vehicle measured by the vehicle and target points comprising the ground marks and ground points;

detecting the relative position of the vehicle with respect to the ground marks by the vehicle each time the vehicle passes the ground marks; and

correcting the current position of the vehicle measured by the vehicle based on the relative position.

19. In a method of guiding an unmanned vehicle provided with a means for measuring a current position of the vehicle and having a steering wheel and a non-steering wheel wherein a passage of the vehicle is taught to the vehicle in the form of a series of target points on the passage and the vehicle is guided along the passage with reference to a current target point among the target points and a current position of the vehicle is measured by the vehicle, where the steering wheel is positioned at rear side of the vehicle as seen in the direction of the movement of the vehicle, said method comprising the steps of:

providing an imaginary steering wheel which is located forward of the non-steering wheel by a length of a wheel base between the steering and non-steering wheels;

obtaining a steering angle and a steering direction when the imaginary steering wheel is oriented toward the current target point; and

operating the steering wheel by said steering angle in the direction opposite to the steering direction.