The torque sensor is used to measure the joint torque of a robot manipulator. Previous research showed that the sensitivity and the stiffness of torque sensors have trade-off characteristics. Stiffness has to be sacrificed to increase the sensitivity of the sensor. In this research, a new torque sensor with high sensitivity (TSHS) is proposed in order to resolve this problem. The key idea of the TSHS comes from its 4-bar linkage shape in which the angular displacement of a short link is larger than that of a long link. The sensitivity of the torque sensor with a 4-bar link shape is improved without decreasing stiffness. Optimization techniques are applied to maximize the sensitivity of the sensor. An actual TSHS is constructed to verify the validity of the proposed mechanism. Experimental results show that the sensitivity of TSHS can be increased 3.5 times without sacrificing stiffness.

As the importance of logistics automation system has increased, researches on related fields such as logistics transportation, city logistics, automation, efficiency, environment friendly technology and unmanned technology have been actively carried out. In order to promote such logistics automation, a huge amount of facilities are invested. Therefore, careful examination of the system is required to build a logistics automation system. In this paper, the design conditions of the logistics robot that transports heavy objects are studied. The design conditions of the logistics robot are derived based on the parallel equations and conduction conditions. The validity of the design conditions was verified through simulation based on 3D modeling and modeling.