A fast adaptive controller for motion control

Limitations in computing speed have for a long time precluded the use of adaptive regulators for controlling fast processes of the type often found in motion control. The advent of digital signal processors (DSP), which admit fast computations at reasonable costs, has removed one obstacle for use of advanced algorithms for motion control. This paper describes implementation of a fast adaptive controller using DSP. The algorithm used is based on robust pole-placement control and a square-root implementation of a recursive estimator. Special attention is given to pre- and postfiltering, which are also handled adaptively using dual rate sampling. The system is implemented using a Macintosh computer with DSP, AD- and DA-boards from National Instruments. The DSP board uses the Texas Instruments TMS320C30, which has floating point hardware. The code is written in C and LabView is used as the man-machine interface. The adaptive controller can be run at sampling rates of several kHz