JPS6410301A - Digital controller - Google Patents

Abstract

PURPOSE:To realize the high-speed response and high accuracy of a digital controller by adding a variable limiter circuit and a variable gain circuit. CONSTITUTION:An adder 2 calculates the deviation epsilon between the control input (u) and the internal state value (y) of a control system. A limiter circuit 3 functions to change its limiting range according to the value of the deviation epsilonso that the rounding way of data is changed. A variable gain circuit 4 eliminates the variation of the loop gain caused by the rounding way of the deviation epsilon and ensures the fixed loop gain of a control system. In such a constitution, even the large deviation epsilon does not affect the internal limit value of the control system and therefore the control value (y) can follow quickly the control input (u). Furthermore the highly accurate follow-up is possible in accordance with the deviation epsilon even though this deviation is small.