HCLC integration design and high-precision control of a joint for space manipulator

A novel method is presented to solve many problems of joints for space manipulator, such as large volume, large flexibility, complex routing and low system-control precision, which can realize integrated design for space manipulator joint with high-cohesion and low-coupling (HCLC) performance. Moreover, the mechanical and electrical interfaces of designed joint are especially suitable for space manipulator. First, To achieve higher system performance, the joint is designed as a whole for perfect match among components including permanent magnet synchronous motor (PMSM), motor controller and driver, sensors, space environment controller, reducer, routing and other mechanisms, which could eliminate redundant shell packages and mounting surfaces existed in traditional manipulator joint. Second, a new method is presented to design the rotors of two resolvers as joint sensors at the same axis shared with motor rotor, this kind of design has the advantages of redundant and high-precision sensing for the positions of motor rotor and joint, and joint position signal is differential sensing and has high robustness. Then, a kind of high-precision controller is presented for space manipulator based on a new PMSM model with model difference, and this controller is robust to joint nonlinear factors, such as friction and other disturbance torque. Finally, the experimental results showed the designed joint had fine performances with high power density, high controlling precision and high operation stability and so on, and it is suitable for the application of space manipulator.