ELECTRONIC CONTROL FOR A TWO-AXIS WORK IMPLEMENT

A loader of the type controlled with an electronic digital controller is disclosed herein. The loader may include conventional mechanical components. However, the hydraulic valve is electronically controlled to provide improved motion control. In particular, the operator controls the loader with a two-axis joystick. When the joystick is moved left or right, the bucket is rolled at a speed proportional to the rate of change of the joystick position and independent of the loader arms. When the joystick is moved forward or backwards, the loader arms of the bucket are raised or lowered. When the joystick is only moved forward or backward with substantially no component of motion left or right, the controller rolls the bucket to maintain a substantially constant angle between the bucket and the loader's frame. This constant attitude control decreases the operator workload and increases control accuracy. The controller provides velocity-based control over the loader arm and bucket motion, or flow-based control for improved stability and accuracy. The controller can monitor available flow and can then limit the commanded flows to the actuators to avoid exceeding the available flow.