Digital control of an interferometric balance for micro-thrusters qualification

The digital control design of an interferometric balance for fine space thruster calibration is presented. The problem was suggested by new micro-thrusters generation aiming at thrusts with sub-micro-Newton resolution. The solution, the Nanobalance instrument, under development, will be employed for on ground qualifying thrust time profile and noise with sub-micro-Newton accuracy. The digital control has been designed and tested in parallel to instrument construction, through a fine numerical simulator of the instrument itself and of the environment disturbances, developed within a proprietary control design environment, ControLab. Severe simulation tests have shown that requirements are met. Next step will be Digital Control Unit interfacing to Nanobalance instrument and testing.