摘要:
Known systems for automatic height control of a dozer blade (302), which rotates about a line through pivot points (304) for supporting arms (303) when it changes its height use feedback and a reference from an absolute blade height measuring system (306). This only permits a slow operation. According to the invention the input from the slow absolute height sensor (306) is combined with an input from a fast gyroscope (307 or 308) that measures the instant rotation and recalculates it into a vertical height change using the length (309) of the supporting arms as the basis. The combination obtains the accuracy of the infrequent absolute height information and an increased speed of measurement resulting in a compensated height estimate that is input to a hydraulic control system of the feedback type. This improved height feedback enables much more aggressive control even though the hydraulic system has an unknown linearity and delay associated with it. The gyroscopic sensor forms an IMU (307 or 308) with one degree of freedom to compensate for the inevitable drawbacks of the absolute height sensor (306) in use with regard to delay, noise and update rate to obtain a frequent, time-correct height position with a reduced level of noise by means of a calculation based on both types of sensor output.