COMBINED GNSS GYROSCOPE CONTROL SYSTEM AND METHOD

• US 20080269988A1
• Filed: 07/11/2008
• Published: 10/30/2008
• Est. Priority Date: 03/20/2003
• Status: Active Grant

• Current Assignee: Hemisphere GNSS(USA) Incorporated
• Original Assignee: Hemisphere GNSS(USA) Incorporated
• Inventors: McClure, John A., Whitehead, Michael L., Feller, Walter J.
• Granted Patent: US 8,265,826 B2
• Time in Patent Office: Days
• US Class Current: 701/41
• CPC Class Codes: A01B 69/007 Steering or guiding of agricultural vehicles, e.g. steering of the tractor to keep the plough in the furrow
• CPC Class Codes: G01C 21/165 combined with non-inertial navigation instruments
• CPC Class Codes: G01S 19/14 specially adapted for specific applications
• CPC Class Codes: G01S 19/53 Determining attitude
• CPC Class Codes: G01S 5/0247 Determining attitude
• 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
• CPC Class Codes: G05D 2201/0201 Agriculture or harvesting machine

Abstract

A global navigation satellite sensor system (GNSS) and gyroscope control system for vehicle steering control comprising a GNSS receiver and antennas at a fixed spacing to determine a vehicle position, velocity and at least one of a heading angle, a pitch angle and a roll angle based on carrier phase position differences. The roll angle facilitates correction of the lateral motion induced position errors resultant from motion of the antennae as the vehicle moves based on an offset to ground and the roll angle. The system also includes a control system configured to receive the vehicle position, heading, and at least one of roll and pitch, and configured to generate a steering command to a vehicle steering system. The system includes gyroscopes for determining system attitude change with respect to multiple axes for integrating with GNSS-derived positioning information to determine vehicle position, velocity, rate-of-turn, attitude and other operating characteristics. A vehicle control method includes the steps of computing a position and a heading for the vehicle using GNSS positioning and a rate gyro for determining vehicle attitude, which is used for generating a steering command.

Claims

1. A method of controlling a vehicle including a steering control mechanism, which method comprises the steps of:

computing a position and a heading for the vehicle using a GNSS multiple antenna system in combination with a rate gyro;

computing a steering control command using said vehicle position and heading;

applying said steering control command to the vehicle steering mechanism;

providing the vehicle steering control mechanism with a control value corresponding to the performance of the vehicle; and

steering said vehicle with said steering control mechanism utilizing said steering control command and said control value.

2. The method of controlling a vehicle according to claim 1, which includes the additional steps of:

basing the steering control command on a first proportionality factor multiplied by a difference in a desired position versus an actual position plus a second proportionality factor multiplied by a difference in a desired heading versus an actual heading; and

insuring with said second proportionality factor that when said vehicle attains said desired position the vehicle is also directed to said desired heading, and thereby avoids crossing a desired track.

3. The method of controlling a vehicle according to claim 1, which includes the additional steps of:

using a recursive, adaptive algorithm to characterize the vehicle response and selected dynamic characteristics;

calculating response times and characteristics for the vehicle based on said responses; and

calibrating said steering control command by applying a modified steering control command based on said responses to achieve a desired response.

4. The method of controlling a vehicle according to claim 1, which includes the additional steps of:

providing a wheel velocity sensor;

tracking vehicle wheel velocity with said wheel sensor;

providing a steering direction sensor;

monitoring wheel direction with said steering direction sensor; and

providing limits and assistance in closing adaptive control tracking loops with said wheel velocity and direction sensors.

5. The method of controlling a vehicle according to claim 4, which includes the additional steps of:

comparing the GNSS-based velocity, the GNSS-based heading and the rate gyro outputs with the wheel velocity sensor output and the steering direction sensor output; and

using said output comparisons to model vehicle slippage and the actual steering rate conditions to enhance the adaptive control loops.

6. The method of controlling a vehicle according to claim 1, which includes the additional steps of:

providing said vehicle with a sprayer including multiple spray nozzles or applicators for applying material to a surface; and

applying material using the rate of change of terrain tilt to adjust spray nozzle or applicator rates to compensate for terrain tilt.

7. The method of controlling a vehicle according to claim 6, which includes the additional steps of:

varying the rates of application of the nozzles or applicators based on turn rates calculated by the gyro and the GNSS receivers to apply the materials at a desired rate.

8. The method of controlling a vehicle according to claim 1, which includes the additional steps of:

providing the vehicle with a tow vehicle and an implement connected to the tow vehicle by an articulated connection;

providing said implement with an implement attitude subsystem including a GNSS receiver and at least two GNSS antennas spaced apart in a fixed, predetermined relation by a rigid link;

providing said implement attitude subsystem with yaw and roll gyroscopes adapted for measuring rates of yaw and roll attitude change for said implement;

calculating the implement'"'"'s attitude values including tilt, slew, heading, yaw rate and roll rate with output from said implement GNSS receiver and said gyroscopes; and

correcting the implement'"'"'s travel path with the vehicle steering mechanism using said calculated implement attitude values.

9. The method of controlling a vehicle according to claim 8, which includes the additional steps of:

providing said tow vehicle with a tow vehicle attitude subsystem including a GNSS receiver and at least two GNSS antennas spaced apart in a fixed, predetermined relation by a rigid link;

providing said tow vehicle attitude subsystem with yaw and roll gyroscopes adapted for measuring rates of yaw and roll attitude change for said vehicle;

calculating yaw and roll rates for the tow vehicle with output from said implement GNSS receiver and gyroscopes;

providing said steering control system with a microprocessor controller;

providing output from said tow vehicle and implement attitude subsystems to said microprocessor controller;

computing steering commands by integrating said tow vehicle and implement attitude subsystem outputs; and

providing said tow vehicle and implement integrated steering commands to said steering control mechanism.

10. The method of controlling a vehicle according to claim 1, which includes the additional steps of:

computing vehicle position and attitude with said GNSS attitude subsystem using measured GNSS carrier phase differences;

providing a yaw gyroscope connected to said GNSS attitude subsystem;

calibrating and initializing said yaw gyroscope with said GNSS-derived attitude;

configuring said yaw gyroscope to derive and provide an output including a yaw angle and a yaw angle rate of change and deriving and providing such output; and

using yaw angle and said yaw angle rate of change outputs from said yaw gyroscope for computing and outputting steering control commands to the vehicle steering system from the current position and heading to the desired position and heading.

11. A method of controlling a vehicle including a steering control mechanism, which method comprises the steps of:

computing a position and a heading for the vehicle using a GNSS multiple antenna system in combination with a rate gyro;

computing a steering control command;

applying selected control values to the vehicle steering control mechanism;

basing the steering control command on a first proportionality factor multiplied by a difference in a desired position versus an actual position plus a second proportionality factor multiplied by a difference in a desired heading versus an actual heading, said second proportionality factor insuring that when said vehicle attains said desired position the vehicle is also directed to said desired heading, and thereby avoids crossing a desired track;

using a recursive, adaptive algorithm to characterize the vehicle response and selected dynamic characteristics;

calculating response times and characteristics for the vehicle based on said responses;

calibrating said control commands by applying a modified control command based on said responses to achieve a desired response;

providing a wheel sensor;

tracking vehicle wheel velocity with said wheel sensor;

providing a steering sensor;

monitoring wheel direction with said steering sensor;

providing limits and assistance in closing tracking loops with said wheel velocity and direction;

comparing the GNSS-based velocity and the gyro and GNSS-based heading with the wheel rate and angle to model the slippage and the steering rate conditions to enhance the adaptive control loops;

providing said vehicle with a sprayer including multiple spray nozzles or applicators for applying material to a surface;

applying materials using the rate of change of tilt to adjust spray nozzle or applicator rates to compensate for roll or tilt of terrain; and

varying the rates of application of the nozzles or applicators based on turn rates calculated by the gyros and the GNSS receivers to apply materials in a desired rate.

12. A sensor system for controlling a vehicle steering system, which sensor system comprises:

a global navigation satellite sensor (GNSS) attitude subsystem including at least one receiver and multiple antennas connected to said receiver or receivers at a fixed spacing, said GNSS attitude subsystem computing vehicle position and attitude using measured GNSS carrier phase differences;

a yaw gyroscope connected to said GNSS attitude subsystem and configured to derive and provide outputs including yaw angles and angular rates of change;

said yaw gyroscope being configured for calibration and initialization using said GNSS-derived attitude; and

a steering control subsystem connected to said yaw gyroscope and said GNSS attitude subsystem and using said yaw angle and yaw angle rate of change outputs from said yaw gyroscope for computing and outputting steering control commands to the vehicle steering system from the current position and heading to the desired position and heading.

13. The sensor system according to claim 12 wherein said steering control subsystem is configured for:

basing the steering control command on a first proportionality factor multiplied by a difference in a desired position versus an actual position plus a second proportionality factor multiplied by a difference in a desired heading versus an actual heading; and

insuring with said second proportionality factor that when said vehicle attains said desired position the vehicle is also directed to said desired heading, and thereby avoids crossing a desired track.

14. The sensor system according to claim 12, wherein said steering control subsystem includes:

a recursive, adaptive algorithm characterizing the vehicle response and selected dynamic characteristics;

said steering control subsystem configured for calculating response times and characteristics for the vehicle based on said responses; and

said steering control subsystem configured for calibrating said steering control command by applying a modified steering control command based on said responses to achieve a desired response.

15. The sensor system according to claim 12, which includes:

a wheel velocity sensor adapted for providing an output corresponding to wheel velocity;

a steering direction sensor adapted for providing output corresponding to wheel direction; and

said steering control subsystem configured for providing limits and assistance in closing adaptive control tracking loops with the output from said wheel velocity and direction sensors.

16. The sensor system according to claim 12 wherein said steering control subsystem is configured for:

comparing the GNSS-based velocity, the GNSS-based heading and the rate gyro outputs with the wheel velocity sensor output and the steering direction sensor output; and

using said output comparisons to model vehicle slippage and the actual steering rate conditions to enhance the adaptive control loops.

17. The sensor system according to claim 12, which includes:

a function for controlling a sprayer associated with said vehicle and including multiple spray nozzles or applicators for applying material to a surface; and

said sprayer control function applying material using the rate of change of terrain tilt to adjust spray nozzle or applicator rates to compensate for terrain tilt.

18. The sensor system according to claim 12, which includes:

said sprayer control function varying the rates of application of the nozzles or applicators based on turn rates calculated by the attitude subsystem to apply the materials at a desired rate.

19. The sensor system according to claim 12, which includes:

said attitude subsystem comprising a tow vehicle attitude subsystem associated with a tow vehicle;

an implement attitude subsystem associated with an implement connected to the tow vehicle by an articulated connection;

said implement attitude subsystem including a GNSS receiver and at least two GNSS antennas mounted on said implement and spaced apart in a fixed, predetermined relation by a rigid link;

said implement attitude subsystem including yaw and roll gyroscopes adapted for measuring rates of yaw and roll attitude change or said implement;

said implement attitude subsystem adapted for calculating yaw and roll for the implement with output from said implement GNSS receiver and gyroscopes; and

said sensor system correcting the implement'"'"'s travel path with the vehicle steering mechanism.

20. The sensor system according to claim 12, which includes:

said steering control subsystem including a microprocessor controller;

said tow vehicle and implement attitude subsystems providing output to said microprocessor controller;

said microprocessor controller computing steering commands by integrating said vehicle and implement attitude subsystem outputs; and

said microprocessor controller providing said vehicle and implement integrated steering commands to said steering control mechanism.

21. The sensor system according to claim 12, which includes:

an enclosure adapted for mounting in a fixed, predetermined orientation on said vehicle; and

said GNSS receiver, antennas and gyroscope being mounted in or on said enclosure.