Abstract
Power assist system is used to reduce human's force with lifting objects. If human applies too large force to power assist system, however, power assist system moves high speed and dangerous for human. If it happens, human can't lift object properly. For that reason, it is necessary to apply correct force by seeing object with power assist system. In order to do so, power assist system must be designed as match human's characteristics. We studied weight perception in lifting object with power assist system and found that human felt about 40% weight compared to weight which we designed in computer system. We think that this situation is caused because of time delay of power assist system. In order to confirm it, we change time delay in computer system and check how much weight human feels.
