JPS6455091A - Controlling device - Google Patents

Abstract

PURPOSE:To realize highly accurate control by a small number of memories, by renewing a stored value at every time when a given number of digital errors are obtained. CONSTITUTION:A 3-phase brushless motor 1 drives the rotations of a rotation sensor 2 and a load 10. Position detecting signals h1, h2, h3 are obtained by using 3 sets of position sensors while driving signals d1, d2, d3 are outputted by a driver 9 to drive. A rotation sensor 2 generates AC signals (a) Zg times per one turn while a speed detector 3 generates a digital signal (b), a clock pulse (q) and a counter overflow signal in accordance with the period of the signals (a). A compensator 4 is constituted of an operator 5, a memory 6, a D/A converter 7 and a rotating position detector 8 and processes the digital signal (b) of the speed detector 3 to output a control signal (c). The operator 5 synthesizes digital errors at every sampling times to renew and reserve a memory at every time when Q sets of synthetic values are obtained. According to this method, the capacity of the memory may be enough by I/Q of the capacity employed so far.