Due to the growing need to reduce costs in hydraulic systems, more cost-effective control methods are being investigated for the proportional control of actuators. One possible solution could be the use of conventional directional control valves. The thesis investigates PWM control of a conventional 2/2 poppet valve with the aim of achieving quasiproportional average flow control. A mathematical description of the valve, a hydraulic test rig and a control program for step-response and PWM measurements were developed. The effects of frequency, duty cycle, pressure and temperature were evaluated experimentally. The results show that average flow can be controlled within a limited operating range, while valve switching times and operating conditions represent the main limitations.
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