Design And Evaluation Of Contactless Power And Signal Transmission Module At Rotary Joint

In multi-actuator mechatronic and distributed multi-sensor systems, it is necessary to transferpower and signal at rotary joint. As the transmission media, cables and slip rings make it difficultto structure design, test and maintenance. Therefore, for solving these problems, it is expected tohave contactless power and signal transmission to replace the cables and slip rings.In this paper, an inductive coupling contactless power transmission (CPT) module and acontactless signal transmission (CST) module are presented. Meanwhile, these two modules areevaluated in detail. The main contents are as follows:(1) The basic principle and structure of presented inductive coupling CPT module are detailedintroduced. Rotary transformer and resonant circuit are analyzed and the main parameters arecalculated. Besides, an effective control method is put forward to stabilize the output voltage underhigh dynamic load.(2) Power transmission test are carried out with lamps and motors. Dynamic load test with lampsevaluates the transmission capacity, efficiency, the response performance under high dynamic loadand the stability of output voltage. Dynamic load test with motors mainly focuses on the influenceof rotary motion on CPT module.(3) The basic principle and structure of presented CST module for industrial field bus are detailedintroduced. Firstly, CST module chooses the optical coupling to bridge CAN bus. Secondly, theoptical coupling for rotary joint is developed. It mainly consists of the optical array design, opticaldrive and receive circuit. Last, the signal converter for CAN bus is presented. Three logicalstrategies are proposed to refine the logical control solution based on ‘Wire-AND’ feature.(4) Signal transmission test are designed. Optical coupling test evaluates the data rate and thetransmission performance of rotary motion. The combined test evaluates the transmissionperformance of whole CST module.