Hitch raise rate calibration method
AssigneeDeere & Company
InventorsWilliam Guy Alexander, Thomas Eugene Boe, Derek Malcolm Eagles, Jianming Yu
Life of this patent
Estimating the term…
Abstract
A method is provided for automatically determining a hitch raise rate calibration value for a hitch control system having a hydraulic actuator for moving the hitch, a valve for controlling flow of hydraulic fluid to the actuator and an electronic hitch control unit. The method includes applying a first control signal to the valve to cause the hitch to raise, determining a first hitch velocity as the hitch moves in response to the first control signal, and repeating these steps for a second control signal. The raise rate calibration value is then calculated as a function of a desired raise velocity, the first and second control signals and the first and second velocities.
Claims6
In a hitch control system having a hitch mounted on a vehicle, a hydraulic actuator for moving the hitch, a hitch position sensor, a valve for controlling flow of hydraulic fluid to the actuator and an electronic hitch control unit for supplying valve control signals to the valve, a method of determining a hitch raise rate calibration value, the method comprising:
- applying a first estimated control signal S1 to the valve to cause the hitch to raise;
- determining a first hitch velocity V1 as the hitch moves in response to the first control signal;
- applying a second estimated control signal S2 to the valve;
- determining a second hitch velocity V2 as the hitch moves in response to the second control signal;
- and
- calculating the raise rate calibration value as a function of the first and second estimated control signals, the first and second hitch velocities, and a desired hitch raise rate.
In a hitch control system having a hitch mounted on a vehicle, a hydraulic actuator for moving the hitch, a hitch position sensor, a valve for controlling flow of hydraulic fluid to the actuator and an electronic hitch control unit for supplying valve control signals to the valve, a method of determining a hitch raise rate calibration value, the method comprising:
- applying a first estimated control signal S1 to the valve;
- storing a first hitch start position Ps1 obtained from the position sensor;
- after a certain delay time period T storing a first hitch end position Pe1 obtained from the position sensor 28;
- calculating a first hitch velocity V1=(Pe1−Ps1)/T;
- applying a second estimated control signal S2 to the valve;
- storing a second hitch start position Ps2 obtained from the position sensor;
- after a certain delay time period T storing a second hitch end position Pe2 obtained from the position sensor;
- calculating a second hitch velocity V2=(Pe2−Pe2)/T;
- and
- calculating the raise rate calibration value according to the following equation.
- REVOFFSET=[((Vdesired−V1)×S2)/(V2−V1)]−[((Vdesired−V2)×S1)/(V2−V1)],
- where Vdesired is a desired hitch raise rate.
Dependencies are inferred from the claim text.