High-cohesion and low-coupling integrative joint for space manipulator

To solve the problems of large volume, complex routing and low system precision of space manipulator, the technology of integrative design is presented to realize high-cohesion and low-coupling integrative joint for space manipulator, which integrates permanent magnet synchronous motor, controller, driver, resolver, adaptability design of space environment, routing and joint mechanism and so on into a whole. To realize each component in joint to match exactly each other, all components of integrative joint are simultaneously planned and designed to achieve high-cohesion and low-coupling. This kind of design can eliminate the redundant shells and mount surfaces in traditional joint of space manipulator, which can increase power density and enhance system performance with a simple mechanical interface and standard electrical interface. This paper proposes a novel method to realize dual-redundancy detection for motor rotor and joint positions by installing two resolvers onto motor shaft at the same time, which can also improve position detection precision and noise immunity by difference principle, decrease joint size and simplify joint structure. In addition, the thermal control and isothermal design are adopted to obtain the temperature balance in integrative joint. Experimental results validated the design scheme in this paper, and it showed that studied integrative joint had nice driving performance to meet the requirements of space manipulator at light weight, high rigidity and high precision.