Many studies of human assist robot systems have been carried out to help daily living activities of physically weak persons in these days. Power-assist robot systems or robotic limbs are examples of the human assist robot system. In order to help the daily living activities of the robot user, the motion intention of the robot user must be estimated in real-time and the estimated motion must be assisted without time delay. Furthermore, the motion of the robot user must be assisted safely. In this presentation, the control methods for the human assist robot systems to help the daily living activities of the physically weak persons are explained. Future directions of the human assist robot systems are also discussed considering the latest related studies.