1. by Patrick Opdenbosch website: http://www.imdl.gatech.edu/opdenboschhttp://www.imdl.gatech.edu/opdenbosch Email: gte608g@prism.gatech.edugte608g@prism.gatech.edu Advisors: Dr. Nader Sadegh, Dr. Wayne Book Fall 2003 Advanced Control Techniques for Electro-Hydraulic Flow Control Valve EHPV ® Technology Abstract The current trend in construction machinery is to use electrically controlled valves (solenoid valves) instead of manually operated hydraulic valves. One of the benefits is that these solenoid valves need not be located in the operator cab. In addition, the employment of these electrically driven valves facilitates computerized control of various machine functions. The Electro-Hydraulic Poppet Valves (EHPV™), a kind of solenoid valves, are used herein for flow control in hydraulic machinery. The flow control through the valve is achieved by changing the valve restriction coefficient via a poppet type orifice with pressure compensation via a Pulse-Width-Modulated current. This project will explore new algorithms and applications via theory, simulation and operation of the valve in Hardware In the Loop (HIL) simulation facility currently under construction Abstract Sponsors: HUSCO International and FPMC Center Main poppet mass Armature mass Pilot pin mass Modulating spring Bias spring Pressure compensating spring Piston mass AB C C1C1 C2C2 Control Pressure Chamber Pilot Head Chamber V sol R sol i sol gap max Electromagnetic Mechanical Hydraulic EHPV Mathematical Model Schematic Control Pressure Chamber Main Poppet Pressure Compensation Spring Piston EHPV Cross-Section View Solenoid Pilot Pin Armature Connection Ports A B C C1C1 C2C2 PWM Driver, Single EHPV ® Model, and Gear Motor Model Proportional-Integral Controller with anti-windup Feedback Control Scheme Non-Linear Model The non-linear mathematical model developed for the EHPV ® is based on the interaction among the Mechanical, Hydraulic, and Electromagnetic subsystems. It also includes a model for a Pulse-Width-Modulation driver, which regulates and modulates the input current to the EHPV ®. Non-Linear Model The non-linear mathematical model developed for the EHPV ® is based on the interaction among the Mechanical, Hydraulic, and Electromagnetic subsystems. It also includes a model for a Pulse-Width-Modulation driver, which regulates and modulates the input current to the EHPV ®. EHPV ® Modeled 10-90% Step Response Step Response A simulated step response (10-90% capacity) was obtained for a single EHPV ®. This response is for constant pressure drop across the valve, and varying (by PWM action) the input current. Step Response A simulated step response (10-90% capacity) was obtained for a single EHPV ®. This response is for constant pressure drop across the valve, and varying (by PWM action) the input current. EHPV B M Hi-press. filter Lo-press. filter Main Pump Load Crossover relief valve Tank Pressure transmitters A Flow meter Pressure relief valve Accumulator M Controller Motor Speed Control with a Single EHPV ® A single EHPV ® is used to control the speed of a gear motor.The speed is set as a sine wave with zero phase, 0.64 Hz, 500 RPM amplitude, and 2000 RPM offset. Motor Speed Control with a Single EHPV ® A single EHPV ® is used to control the speed of a gear motor.The speed is set as a sine wave with zero phase, 0.64 Hz, 500 RPM amplitude, and 2000 RPM offset. Hydraulic Circuit Employed for Motor Speed Control Closed-loop Response Closed-loop Response’s Duty Cycle Profile Actuator Displacement Control Using EHPV ® Wheatstone Bridge Configuration 4 EHPV ® ‘s are used to control the displacement of a passive actuator. The controller receives a desire performance criterion (not shown) along with pressure data from the upstream and downstream portions of each valve. The controller in turn sends PWM signals to the EHPV ® ’sare used in an adaptive and trainable algorithm to manipulate Actuator Displacement Control Using EHPV ® Wheatstone Bridge Configuration 4 EHPV ® ‘s are used to control the displacement of a passive actuator. The controller receives a desire performance criterion (not shown) along with pressure data from the upstream and downstream portions of each valve. The controller in turn sends PWM signals to the EHPV ® ’sare used in an adaptive and trainable algorithm to manipulate (UNDER DEVELOPMENT)