Two complementary techniques for motion control of power assist system for lifting objects based on human characteristics

A power assist system reduces the weight of an object lifted with it. But, the human operator cannot differentiate between the perceived weight and the actual weight and eventually applies excessive load force. This faulty force programming (excessive load force) results in faulty motions of the power assist system and jeopardizes its maneuverability, ease of use, naturalness, human-friendliness, safety etc. This article presents two complementary techniques for motion control of a power assist system for lifting objects. The first technique controls the motion of the power-assist-lifted object by optimizing the perceived heaviness, haptic and tactile sensations. The second technique controls the motion by applying a novel control strategy based on load force and perceived weight. The two techniques together optimize the motion of the power-assist-lifted object. The findings can be used to develop power assist robot systems for carrying heavy objects in various industries.