Motor control systems

摘要

1,103,731. Automatic control of speed. BROOKHIRST IGRANIC Ltd. March 11, 1965 [March 13, 1964], No.10358/65. Heading G3R. An electric motor 5 is controlled in speed and angular position in relation to reference pulses 10 by a system in which the time for a given count of reference pulses is compared with that for a like count of motor speed pulses from a tachogenerator 11, and any difference is arranged to energize one or the other of two control windings in a magnetic amplifier 7 controlling the field of a generator which powers the motor. Coarse speed control is effected by two further control windings on the magnetic amplifier which are supplied with square pulses from 8 and 9 of constant magnitude and duration, but at a frequency corresponding to that of the reference oscillator 10 and tachogenerator 11 respectively. The output of the counters 12, 13 is a signal which changes from 0 to -10 volts at the end of each count (e. g. 4), and this is supplied to pulsers 14, 15 together with relatively high frequency square "clock" pulses from a multi-vibrator 16. The output of 14 and 15 is square pulses displaced relative to each other by an amount corresponding to increments of angular error. Comparison is made at 17, the output of which is applied to a five position register 18. This stores a single information "bit" which is transferred between the positions by the comparison device 17. If no error exists the "bit" is in store III and neither control winding is energized. If the motor lags slightly the "bit" is transferred between II and III, the relative durations in each being indicative of the average phase displacement; the appropriate control winding is energized when the bit is in I or II (lagging) or IV and V (leading error). Greater errors cause the "bit" to move between I and II (or IV and V), or finally remain continuously in I or V. The electronics are fully described, and comprise transistor multi-vibrators and bistable or mono-stable circuits Figs. 2a, b, c (not shown). The tachogenerator comprises a magnetic impulse wheel.