Non-uniform error-sampled control system

A nonuniform ADC (analog-to-digital converter) is shown to be a viable option for a system designed for zero or small steady state errors. The choice of quantization levels is based on the ease of hardware implementation, speed of response, and the idea that, in control systems designed for zero steady state error, it should be sufficient to know the error with certain precision around zero, but that away from zero the same precision need not be necessary. A describing function analysis of the effect of the nonlinearity due to nonuniform quantization is presented. Some simulation results are also included