Vehicle control system

• US 7,835,832 B2
• Filed: 01/05/2007
• Issued: 11/16/2010
• Est. Priority Date: 01/05/2007
• Status: Active Grant

• Current Assignee: Agjunction LLC (Kubota Corporation)
• Original Assignee: Hemisphere GPS LLC (Kubota Corporation)
• Inventors: Macdonald, Andrew John, Morrison, Campbell Robert, Reeve, David Robert
• Primary Examiner(s): Tran; Khoi
• Assistant Examiner(s): KING, RODNEY P
• Application Number:
  US11/620,388
• Publication Number:
  US 20080167770A1
• Time in Patent Office: 1,411 Days
• Field of Search: 701/50, 701/109, 701/213, 701/24
• US Class Current: 701/24
• CPC Class Codes: A01B 69/008 automatic
• CPC Class Codes: A01B 79/005 Precision agriculture
• CPC Class Codes: G01C 21/188 for accumulated errors, e.g. by coupling inertial systems with absolute positioning systems
• CPC Class Codes: G01S 17/86 Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders
• CPC Class Codes: G01S 19/03 Cooperating elements; Interaction or communication between different cooperating elements or between cooperating elements and receivers
• CPC Class Codes: G01S 5/02521 using a radio-map
• CPC Class Codes: G05D 1/0223 involving speed control of the vehicle vehicle fittings for automatically controlling, i.e. preventing speed from exceeding an arbitrarily established velocity or maintaining speed at a particular velocity, as selected by the vehicle operator B60K31/00
• CPC Class Codes: G05D 1/024 in combination with a laser lasers per se H01S
• 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 1/0259 using magnetic or electromagnetic means
• 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 1/0278 using satellite positioning signals, e.g. GPS

Abstract

A vehicle control system having a controller and a spatial database adapted to provide spatial data to the controller at control speed. The spatial data provided from the spatial database to the controller can be any kind of data or information that has some relationship or association with “real world” geographical location, or if it is stored somehow with reference to geographical location. The spatial data received by the controller from the database forms at least part of the control inputs that the controller operates on to control the vehicle. The fact that the controller operates directly on information that is inherently associated with “real world” geographic location represents a change in thinking compared with existing vehicle control systems. In particular, it means that the control system of the present invention “thinks” directly in terms of spatial location. A vehicle control system in accordance with one particular embodiment of the invention comprises a task path generator, a spatial database, at least one external spatial data receiver, a vehicle attitude compensation module, a position error generator, a controller, and actuators to control the vehicle.

Claims

1. A control system for controlling a vehicle and an implement towed by the vehicle within a region to be traversed, the vehicle including an automatic steering system and roll, pitch and yaw axes, and the control system comprising:

a spatial database containing spatial data corresponding to GPS-defined positions in the region,

a controller adapted to receive spatial data from the spatial database at control speed to control the vehicle as the vehicle traverses the region, the controller being adapted to control the steering of the vehicle,

external spatial data sources mounted on the vehicle and comprising;

a GPS system including an antenna and a receiver;

an inertial navigation system (INS) including a gyroscope and an accelerometer;

a tilt sensor; and

a visual sensor adapted for receiving images of the ground beneath the vehicle and inputting the images to the controller,

the controller correlating the images to obtain data relating to the vehicle'"'"'s motion,

a vehicle reference point located at an intersection of the vehicle roll, pitch and yaw axes,

an implement reference point associated with a location on the implement,

the spatial database being adapted to receive updated spatial data from the controller and the external spatial data sources as the vehicle traverses the region,

the updated spatial data relating to a combination of the vehicle, the implement associated with and proximate the vehicle, the region or at least a portion of the region proximate the vehicle,

the controller receiving a user-defined path trajectory comprising desired vehicle positions, desired vehicle headings and desired vehicle radii of curvature,

the controller inputting the user-defined path trajectory into the spatial database,

the controller including a task path generator receiving data from spatial database,

the controller including a vehicle attitude compensation module,

a position error generator adapted for comparing said user-defined path trajectory with spatial data from said spatial database corresponding to an actual vehicle trajectory,

said controller being adapted for updating said path trajectory based on said position error generator comparison, and

said controller including a cross-track error proportional-integral-derivative (PID) controller, a heading error PID controller and a curvature error PID controller providing input to said vehicle attitude compensation module for use by said position error generator in connection with correcting said path trajectory.

2. A control system as claimed in claim 1, wherein the spatial database is adapted to provide spatial data to other parts of the control system.

3. A control system as claimed in claim 1, wherein the spatial data received by the controller from the spatial data base forms at least part of the control inputs that the controller uses to control the vehicle.

4. A control system as claimed in claim 1 having a feed forward control structure.

5. A control system as claimed in claim 1, wherein the control system has memory and a central processing unit.

6. A control system as claimed in claim 1, having a closed loop or feedback control structure.

7. A control system as claimed in claim 6, implemented using a state space representation.

8. A control system as claimed in claim 7, having a state feedback control structure.

9. A control system as claimed in claim 7, having an output feedback control structure.

10. A control system as claimed in claim 6, wherein the controller operates using a combination of proportional, integral and differential control.

11. A control system as claimed in claim 10, wherein the controller comprises a plurality of nested control loops.

12. A control system as claimed in of claim 1, having an open loop control structure.

13. A control system as claimed in claim 1 including actuators responsive to a control signal produced by the control system.

14. A control system as claimed in claim 1, incorporating means for filtering updated spatial data.

15. A control system as claimed in claim 1, wherein the updated spatial data is filtered in real time or close to it.

16. A control system as claimed in claim 13, incorporating signal transmitting means for transmitting one or more control signals from the control system to the actuators.

17. A control system as claimed in claim 16, comprising amplifiers to amplify the control signal transmitted to the actuators.

18. A control system as claimed in claim 1, wherein the database exhibits low latencies between its inputs and outputs.

19. A control system as claimed in claim 1, wherein there is at least one clock speed associated with the controller, and the database is adapted to provide data to the controller at a rate of the same order as at least one of said clock speeds.

20. A control system as claimed in claim 19, wherein the spatial database is adapted to provide data to the controller at a rate of between 1 Hz and 100 Hz.

21. A control system as claimed in claim 20, wherein the spatial database is adapted to provide data to the controller at a rate of between 1 Hz and 20 Hz.

22. A control system as claimed in claim 21, wherein the spatial database is adapted to provide data to the controller at a rate of between 3 Hz and 12 Hz.

23. A control system as claimed in claim 1, wherein the database is loaded into the control system'"'"'s memory.

24. A control system as claimed in claim 1, wherein the database is loaded on a disk or other storage device separate from the control system'"'"'s memory.

25. A control system as claimed in claim 1, wherein the spatial data base has a flat structure.

26. A control system as claimed in claim 1, wherein every item of spatial data is indexed uniquely in the database.

27. A control system as claimed in claim 1, wherein the vehicle is an agricultural vehicle and the region is a field.

28. A method for controlling a vehicle and an implement towed by the vehicle within a region to be traversed, the vehicle including an automatic steering system and roll, pitch and yaw axes, the method comprising the steps:

providing a spatial database;

populating said database with spatial data corresponding to GPS-defined positions in the region;

providing a position error generator;

providing a controller;

mounting said controller to said vehicle;

traversing the region with said vehicle towing said implement;

receiving spatial data with said controller from the spatial database at control speed;

controlling the steering of the vehicle with the controller as the vehicle traverses the region;

providing the controller with a task path generator;

receiving data from the spatial database with the controller and controller task path generator;

providing the controller with a vehicle attitude compensation module;

providing the controller with a cross-track error proportional-integral-derivative (PID) controller, a heading error PID controller and a curvature error PID controller;

providing input to said vehicle attitude compensation module and using said position error generator in connection with attitude compensation module for correcting said path trajectory;

mounting external spatial data sources on the vehicle, said external spatial data sources comprising;

a GPS system including an antenna and a receiver;

an inertial navigation system (INS) including a gyroscope and an accelerometer;

a tilt sensor; and

a visual sensor;

receiving images of the ground beneath the vehicle using the controller and visual sensor;

inputting said ground images to the controller;

correlating the images with said controller to obtain data relating to the vehicle'"'"'s motion;

designating and locating a vehicle reference point at an intersection of the vehicle roll, pitch, and yaw axes;

locating and associating an implement reference point on the implement;

updating said spatial database with spatial data from the controller and said external spatial data sources as the vehicle traverses the region;

inputting a user-defined path trajectory comprising desired vehicle positions, desired vehicle headings, and desired vehicle radii of curvature into said controller;

inputting the user-defined path trajectory into the spatial database with said controller;

comparing the user-defined path trajectory with spatial data from said spatial database corresponding to an actual vehicle trajectory using said position error generator;

updating said path trajectory with said controller based on said position error generator comparison; and

steering the vehicle and using updated path trajectory.

29. The method of claim 28, wherein:

the vehicle is an agricultural vehicle; and

the region is a field.

30. The method of claim 28, further comprising the step:

providing spatial data to other parts of the control system using the spatial database.

31. The method of claim 28, further comprising the step:

forming at least part of the control inputs the controller uses to control and steer the vehicle from spatial data received by the controller from the spatial database.

32. The method of claim 28, further comprising the step:

providing a feed forward control structure.

33. The method of claim 28, further comprising the steps:

providing a memory storage device;

providing a central processing unit; and

connecting said memory storage device and central processing unit to the controller.

34. The method of claim 28, further comprising the step:

providing a closed loop or feedback control structure.

35. The method of claim 28, further comprising the step:

providing actuators responsive to control signals produced by the controller.

36. The method of claim 28, further comprising the step:

providing a means for filtering updated spatial data.

37. The method of claim 36, further comprising the step:

filtering updated spatial data in real time or close to it.

38. The method of claim 28, wherein the database exhibits low latencies between its inputs and its outputs.

39. The method of claim 28, further comprising the steps:

providing at least one clock speed associated with the controller; and

providing data to the controller at a rate of the same order as at least one of said clock speeds using the database.

40. The method of claim 33, further comprising the step:

loading the database into the control system'"'"'s memory storage device.

41. The method of claim 33, further comprising the step:

loading the database onto a disk or other storage device separate from the control system'"'"'s memory storage device.

42. The method of claim 28, wherein the spatial data base has a flat structure.

43. The method of claim 42, further comprising the step:

indexing every item of spatial data uniquely within the database.