Harmonic motion analysis and control for manipulating objects with a power assist robot based on human characteristics

We developed a one-degree-of-freedom (vertical up-down motion) power assist robot for manipulating objects. The robot system was simulated and subjects manipulated objects with the robot in harmonic motion i.e. the objects were repeatedly lifted up and lowered down during the simulation. We then critically analyzed human's weight perception, load forces and object's motion features. We then introduced a novel control strategy to reduce the excessive load forces applied by the subjects. The novel control strategy produced satisfactory maneuverability, safety, naturalness, ease of use, stability etc. of the robot system. We also compared the findings derived in harmonic motion to that derived in linear vertical motion (lifting objects vertically). Finally, we proposed using the findings to develop human-friendly power assist devices to manipulate heavy objects in various industries such as mining, manufacturing and assembly, construction, transport and logistics, rescue and military operations etc.