SPEED CONTROL METHOD, DEVICE, SYSTEM FOR ELECTRO-HYDRAULIC PROPORTIONAL VALVE AND ENGINEERING MACHINERY WITH THE SAME

摘要

Disclosed in the present invention are a speed control method, device, system for an electro-hydraulic proportional valve and engineering machinery with the same. The method comprises: obtaining the actual speed of a hydraulic execution element; when the difference between the actual speed and expected speed is larger than a predetermined value, adjusting the frequency and/or duty cycle of a PWM (pulse width modulation) signal provided to the electro-hydraulic proportional valve basing on the difference; calculating the frequency and/or amplitude of a shaking signal according to the frequency and/or duty cycle of the adjusted PWM signal, and adjusting the amplitude of the calculated shaking signal according to the rate of change of the difference between the actual speed and the expected speed; and, providing the adjusted shaking signal as well as the adjusted PWM signal to the electro-hydraulic proportional valve. The method enables providing a shaking signal that overcomes the static friction of a valve core of the electro-hydraulic proportional valve to the electro-hydraulic proportional valve, thus improving response speed and linearity of the electro-hydraulic proportional valve.