A versatile motion control system for astronomical instrumentation

With steadily increasing telescope sizes and the growing complexity of scientific instruments, there is an ever-growing demand for improved electronics, controlling all the different optical parts on moving mechanisms. Among competing requirements are, on one hand, the increasing number of actuators, with high-precision positioning in closed and open loop, and on the other hand, smaller sizes, low power and restricted heat emission. A specific challenge is accommodating mechanisms that operate in infrared instrumentation at cryogenic temperatures down to 60 Kelvin. In this area piezo motors offer promising solutions. To fulfill these different demands a competitive motion control system has been developed at the Max-Planck-Institut fur Astronomie (MPIA) in Heidelberg, Germany. A modular chassis with standardized boards provides best solutions for extensive tasks. High and low power DC servo motors, brushless DC servo motors, stepper motors and piezo motors with different technologies are supported. Diversity position feedback capabilities, like incremental and absolute encoders for non cryogenic and capacitive sensors and resolvers for cryogenic applications, are provided.