Uncommanded steering detection

A method for detecting and responding to uncommanded motion in a machine having a hydraulic steering cylinder with a steering piston that moves in a first piston direction to cause the machine to turn in a first turn direction and moves in a second piston direction to cause the machine to turn in a second turn direction, the method for detecting and responding to uncommanded motion in the machine comprising:

• generating, at an electronic control unit, a steering command signal to move the steering piston in one of the first piston direction and the second piston direction;
• determining, at the electronic control unit, an actual steering piston position of the steering piston;
• comparing, at the electronic control unit, the actual steering piston position to a commanded steering piston position;
• determining, at the electronic control unit, a steering position error in response to determining that the actual steering piston position is not equal to the commanded steering piston position;
• adding, at the electronic control unit, the steering position error to a cumulative integration value for uncommanded motion, the cumulative integration value being increased so long as the actual steering piston position is not equal to the commanded steering piston position;
• comparing, at the electronic control unit, the cumulative integration value to an integration limit for uncommanded motion of the machine;
• and
• executing, at the electronic control unit, 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 having a steering control mechanism that causes the machine to turn in a first turn direction and in a second turn direction, the method for detecting and responding to uncommanded motion in the machine comprising:

• generating, at an electronic control unit, a steering command signal to cause the steering control mechanism to turn the machine in one of the first turn direction and the second turn direction;
• determining, at the electronic control unit, an actual steering direction of the machine;
• comparing, at the electronic control unit, the actual steering direction to a commanded steering direction of the steering command signal;
• calculating, at the electronic control unit, a steering position error in response to determining that the actual steering direction is not equal to the commanded steering direction, wherein the steering position error is set to a greater value in response to determining that the actual steering direction is opposite the one of the first turn direction and the second turn direction in the steering command signal;
• adding, at the electronic control unit, the steering position error to a cumulative integration value for uncommanded motion, the cumulative integration value being increased so long as the actual steering direction is not equal to the commanded steering direction;
• comparing, at the electronic control unit, the cumulative integration value to an integration limit for uncommanded motion of the machine;
• and
• executing, at the electronic control unit, an uncommanded motion response strategy in response to determining that the cumulative integration value is greater than the integration limit.