Detection of uncommanded motion of a steering motor

A method for detecting and responding to uncommanded motion in a machine where differential motion is created to steer the machine, the method comprising:

• generating, at a control unit, a command signal of the machine to move the machine along a commanded path of motion;
• determining, at the control unit, an actual path of motion of the machine;
• comparing, at the control unit, the actual path of motion to the commanded path of motion;
• determining, at the control unit, a weighted steering motor speed of the machine in response to determining that the actual path of motion is not equal to the commanded path of motion, wherein the weighted steering motor speed is based on an actual steering motor speed of a steering motor of the machine;
• adding, at the control unit, the weighted steering motor speed to a cumulative integration value for uncommanded motion, the cumulative integration value being increased so long as the actual steering motor speed is not equal to a commanded steering motor speed;
• comparing, at the control unit, the cumulative integration value to an integration limit for uncommanded motion of the machine;
• and
• executing, at the control unit, an uncommanded motion response strategy in response to determining that the cumulative integration value is greater than the integration limit.

A differential steering control system for a machine where differential motion is created to steer the machine, the system comprising:

• a transmission for moving the machine in a forwards or a backwards direction;
• a steering motor for steering the machine in a leftwards or a rightwards direction;
• a steering device for providing turn direction signals indicating a desired direction of motion to cause the machine to move on a commanded path of motion;
• and
• a control unit operatively connected to the transmission, the steering motor, and the steering device,
• the control unit being programmed to receive the turn direction signals from the steering device and to output steering motor speed command signals to cause the steering motor to operate at a commanded steering motor speed to move the machine along the commanded path of motion,
• the control unit being programmed to determine an actual steering motor speed,
• the control unit being programmed to compare the actual steering motor speed to the commanded steering motor speed,
• the control unit being programmed to determine a cumulative integration value in response to determining that the actual steering motor speed is not equal to the commanded steering motor speed, wherein the cumulative integration value is based on the actual steering motor speed and modified for each determination that the actual steering motor speed is not equal to the commanded steering motor speed,
• the control unit being programmed to determine an integration limit for weighted steering motor speed based on a value of a parameter indicative of an ability of the machine to produce the commanded motion,
• the control unit being programmed to compare the cumulative integration value to the integration limit, and
• the control unit being programmed to execute an uncommanded motion response strategy in response to determining that the cumulative integration value is greater than the integration limit.

A method for detecting and responding to uncommanded motion in a machine where differential motion is created to steer the machine, the method comprising:

• commanding, at a control unit, the machine to move along a commanded path of motion;
• determining, at the control unit, an actual path of motion of the machine;
• comparing, at the control unit, the actual path of motion to the commanded path of motion;
• determining, at the control unit, a cumulative integration value for uncommanded motion in response to determining that the actual path of motion is not equal to the commanded path of motion, wherein the cumulative integration value is based on a difference between an actual steering motor speed of a steering motor of the machine and a commanded steering motor speed, and modified for each determination that the actual path of motion is not equal to the commanded path of motion;
• determining, at the control unit, an integration limit for uncommanded motion of the machine, wherein the integration limit is based on a value of a parameter indicative of an ability of the machine to respond to uncommanded motion;
• comparing, at the control unit, the cumulative integration value to the integration limit;
• and
• executing, at the control unit, an uncommanded motion response strategy in response to determining that the cumulative integration value is greater than the integration limit.