| 摘要 |
PURPOSE:To control a driving speed variably and stably by a method wherein a speed control means controls the output frequency of a power supply means in accordance with a fuzzy rule concerning the speed deviation between a target speed and a speed detected by a speed detecting means. CONSTITUTION:When a speed deviation is +10rpm, i.e., the speed is too high, the compatibility of a fuzzy expression, 'a little faster (PS)', is '1' and a frequency deviation corresponding to the compatibility is +0.05kHz. Therefore, the output frequency of a power supply means 5 is increased from the present value by 0.05kHz. In a region where a plurality of membership functions overlap each other, a weighted average value is obtained in accordance with the ratios of the compatibilities of the respective membership functions. That is to say, if the speed is higher than the target speed, the output frequency is increased to reduce the speed and, if the speed is lower than the target speed, the output frequency is reduced to increase the speed, so that the speed is always controlled to be the target speed. The rate of the variation of the output frequency is determined by a membership function produced in accordance with empirical values obtain by experiments. |
