Motion control of an aerial work platform

An articulated aerial work platform is a type of off highway vehicle with a long/flexible beam to provide temporary access to inaccessable areas. The motivation of the research is to improve productivity and safety of the work platform via advanced control schemes. In this paper, a motion control architecture is presented for trajectory tracking and vibration suppression. By using the sensors integrated in hydraulic power elements, a closed loop coordinated control is presented to allow the end effector of the work platform to track a desired trajectory, thus alleviating the demand on operators´ proficiency and improving productivity. In order to reduce the tracking error caused by the beam deflection, a static deflection compensation controller has been developed. In terms of vehicle safety, it has been observed that vibration associated with the long beam is significant, and the vibration characteristics change according to vehicle geometry. A unique input shaper is presented with the two impulses and the time varying parameters. The benefits are gaining robustness with respect to geometric variation, as well as reducing time delay for better responsiveness. The experimental study validates the controller.