摘要 |
An apparatus and method for controlling a hydraulically movable tool carried by a machine in order to maintain a selected horizontal orientation and a selected elevation relative to an external light reference. The apparatus is a control device, having a light detector, placed at a known location along a longitudinal axis of the tool and a single-axis gravity-based sensor. The gravity-based sensor is also provided within the housing of the control device to measure the horizontal orientation (side-to-side slope or pitch) of the longitudinal axis of the tool relative to true horizontal at the known location. Finally, with internal valve drivers, the control device individually controls the lift mechanism(s) of the hydraulically movable tool to maintain both a selected elevation and a selected horizontal orientation with only the signals provided by the light detector and the gravity-based sensor.
|