Abstract: In the nuclear industry hot cell and radioactive environment, because the operator cannot directly enter the closed hot cell, only the master-slave manipulator can be used for remote control operation. This research proposed a gravity compensation method for a master-slave telemanipulator to maintain its own steady state. Firstly, it introduced the configuration of the master-slave telemanipulator in the hot cell and the control working principle of the master-slave manipulator. Secondly, the coordinate and angle transformation matrix is established by D-H kinematics analysis of the master manipulator, and the angle transformation matrix between the rotary encoder and the motor output shaft is obtained through the kinematic chain analysis. Besides we also established the relationship matrix between each joint and the motor. Thirdly, the torque of each moving part of the master manipulator to each output shaft in each posture is calculated, converted to the motor output shaft, so the motor outputted the reverse compensation torque to maintain a steady state. Finally, test verification is carried out on the test system of master-slave telemanipulator. Theoretical analysis and experiment show that the gravity compensation algorithm is accurate and the compensation effect is remarkable.

Key words: hot cell, master-slave telemanipulator, kinematics, relation matrix, gravity compensation