抄録
This report treats of the improvements of the fluidic PID controller operated with PWM signals one of the authors reported previously. The main points of improvements are the use of the new saw-tooth wave form for PWM and the use of the delay line composed of logical circuits instead of the propagation lag of pressure wave.
The analog signal is converted into PWM signal by the fluidic comparator and the sawtooth pressure wave whose rear side is used for the modulation. The obtained PWM signal is delayed by one period and two periods by the delay line. Analog PID control modes are obtained by a differential type algorithm between the original signal and the delayed signals, and by the demodulation with capacities. There are no interferences among three control modes.
The delay line consists of fluidic logical circuits and monostable multi-vibrators composed of an impulse generator and constant time hold circuits. Factors affecting the performance of the delay line are discussed here.
