GNSS and optical guidance and machine control
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 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. Relative orientations and attitudes between motive and working components can be determined using optical sensors and cameras. The system can also be used to guide multiple vehicles in relation to each other.
1. A control system for controlling a vehicle, the vehicle attached to a sprayer and the sprayer including multiple spray nozzles for applying a material, the control system comprising:
a processor; and
a memory including one or more sequences of instructions stored in the memory which, when executed by the processor, cause the processor to:
receive, by a control system, attitude measurements for the vehicle or sprayer;
compute, by the control system, a tilt rate of change of the vehicle or sprayer based on the attitude measurements; and
adjust, with the control system, an application rate of the material output by the spray nozzles based on the tilt rate of change of the vehicle or sprayer.
2. The control system of claim 1 , the instructions when executed by the processor further comprising:
calculating, by the control system, a turn rate of the vehicle or sprayer; and
varying the application rate of the material output by the spray nozzles based on the turn rate of the vehicle or sprayer.
3. The control system of claim 1 , the instructions when executed by the processor further comprising receiving as part of the attitude measurements a roll-rate from a gyroscope located on the vehicle or sprayer.
4. The control system of claim 1 , the instructions when executed by the processor further comprising:
computing, by the control system, a heading of the vehicle or sprayer based on a measured x, y, z position of the vehicle or sprayer;
computing, by the control system, a roll angle of the vehicle or sprayer based on the measured x, y, z position; and
computing, by the control system, a true ground position of the vehicle or sprayer based on the heading of the vehicle or sprayer and the roll angle of the vehicle or sprayer.
5. The control system of claim 4 , the instructions when executed by the processor further comprising:
computing, by the control system, a ground position error between the true ground position of the vehicle or sprayer and a desired ground position of the vehicle or sprayer based on the measured x, y, z position; and
adjusting, by the control system, steering control commands based on the ground position error.
6. The control system of claim 1 , the instructions when executed by the processor further comprising:
computing, by the control system, an actual heading of the vehicle or sprayer from a measured x, y, z position of the vehicle or sprayer;
computing, by the control system, a heading error between the actual heading of the vehicle or sprayer and a desired heading of the vehicle or sprayer; and
adjusting, by the control system, steering control commands based on the heading error so the vehicle or sprayer avoids crossing a desired track.
7. The control system of claim 1 , the instructions when executed by the processor further comprising:
computing, by the control system, a first x, y, z position of the vehicle or sprayer from a first global positioning system (GPS) receiver;
computing, by the control system, a second x, y, z position of the vehicle or sprayer from a second global positioning system (GPS) receiver; and
computing, by the control system, a true ground position of the vehicle or sprayer based on a difference between the first x, y, z position of the vehicle or sprayer and the second x, y, z position of the vehicle or sprayer.
8. The control system of claim 1 , the instructions when executed by the processor further comprising:
computing, by the control system, a first x, y, z position of the vehicle or sprayer from a first global positioning system (GPS) receiver;
computing, by the control system, a second x, y, z position of the vehicle or sprayer from a second global positioning system (GPS) receiver;
computing, by the control system, a reference yaw and roll based on the first x, y, z position of the vehicle or sprayer and the second x, y, z position of the vehicle or sprayer; and
calibrating, by the control system, yaw and roll gyroscopes on the vehicle or sprayer based on the reference yaw and roll.
9. The control system of claim 1 , the instructions when executed by the processor further comprising:
recursively generating, by the control system, steering commands to steer the vehicle;
recursively measuring, by the control system, responses of the vehicle to the steering commands; and
calibrating, by the control system, the steering commands based on the recursively measured responses of the vehicle to the steering commands.
10. A control system for controlling a vehicle, comprising:
a processor; and
one or more sequences of instructions stored on a tangible computer-readable media which, when executed by the processor, cause the processor to:
receive a vehicle position and attitude derived from a global navigation satellite system (GNSS) system;
calibrate one or more gyroscopes based on the GNSS-derived attitude;
receive a yaw angle and a yaw angle rate of change from the one or more calibrated gyroscopes; and
adjust steering control commands sent to a vehicle steering system to move the vehicle from a current location and heading to a desired location and heading where the vehicle is to move based on the yaw angle and yaw angle rate of change.
11. The control system of claim 10 , wherein the instructions further cause the processor to:
receive a tilt rate of change from the one or more calibrated gyroscopes; and
adjust an application rate of a material output from a sprayer attached to the vehicle based on the tilt rate of change.
12. The control system of claim 10 , wherein the instructions further cause the processor to:
calculate a turn rate of the vehicle from the attitude received from the GNSS system or the yaw angle rate received from the one or more calibrated gyroscopes; and
adjust an application rate of a material output from a sprayer attached to the vehicle based on the turn rate of the vehicle.
13. The control system of claim 10 , wherein the instructions further cause the processor to:
determine a tire slippage based on a comparison of a GNSS-based measured velocity with a wheel sensor-based measured velocity; and
adjust an application rate of a material output from a sprayer attached to the vehicle based on the tire slippage.
14. The control system of claim 10 , wherein:
the GNSS system includes at least one receiver and multiple antennas connected to the at least one receiver at a fixed spacing; and
the GNSS system computes the vehicle position and attitude based on measured GNSS carrier phase differences from the antennas.
15. The control system of claim 10 , wherein the instructions further cause the processor to:
compute an actual heading of the vehicle from the vehicle attitude;
compute a heading error between the actual heading of the vehicle and a desired heading of the vehicle; and
biasing the steering control commands based on the heading error to avoid crossing a desired track of the vehicle.
16. The control system of claim 10 , wherein the instructions further cause the processor to:
recursively generate steering commands to steer the vehicle;
recursively measure responses of the vehicle to the steering commands; and
calibrate the steering commands based on the recursively measured responses of the vehicle to the steering commands.
17. The control system of claim 10 , wherein the GNSS system and the one or more gyroscopes are located on the vehicle or located on an implement towed by the vehicle.
18. A control system for controlling a vehicle, the vehicle attached to a sprayer having multiple spray nozzles for applying a material to a terrain, comprising:
a processor; and
one or more stored sequences of instructions stored on a tangible computer-readable media which, when executed by the processor, cause the processor to:
receive attitude measurements for the vehicle or sprayer;
calculate a turn rate of the vehicle based on the attitude measurements; and
adjust an application rate of the material output from the spray nozzles based on the turn rate of the vehicle.
19. The control system of claim 18 , wherein the instructions further cause the processor to:
compute a tilt rate of change of the terrain based on the attitude measurements; and
adjust the application rate of the material output from the spray nozzles based on the tilt rate of change in the terrain.
20. The control system of claim 18 , wherein the instructions further cause the processor to:
determine a tire slippage based on a comparison of a GNSS-based velocity of the vehicle with a wheel sensor-based velocity of the vehicle; and
adjust the application rate of the material output from the spray nozzles based on the tire slippage.