EHPV Technology Sponsored by HUSCO Intl the FPMC
® EHPV Technology Sponsored by HUSCO Intl. & the FPMC Center PATRICK OPDENBOSCH Graduate Research Assistant NADER SADEGH Ph. D. Mechanical Engineering Professor WAYNE BOOK Ph. D. Mechanical Engineering Professor Georgia Institute of Technology George W. Woodruff School of Mechanical Engineering 10/7/2020
AGENDA • Purpose • Valve overview. • Principle of operation. • Mathematical modeling. • Simulation results. • Non-linear controller. • Hardware-In-the-Loop (HIL) • Future work. GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
PURPOSE Development of a trainable nonlinear controller for flow control through a 4 -way EHPV® arrangement that compensates for inherent system non-linearities such as hysteresis. GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
VALVE OVERVIEW • Electro-Hydraulic Poppet Valves (EHPV®) are pilot operated valves used for flow control in hydraulic machinery. • The flow control is achieved by changing the valve restriction coefficient via a PWM input current acting on a pilot and a poppet type orifice with pressure compensation. GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
VALVE OVERVIEW • Bi-Directional Capability • Pressure compensation for consistent current at flow initiation. • Adequate Dynamic Response (Step Response: 80 ms 10%-90%) • “Zero” leakage (< 0. 5 cc/min) • Low Hysteresis (< 5%) • 12 Volt System 1. 5 Amp max current per solenoid. GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
VALVE OVERVIEW Compact View GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
VALVE OVERVIEW Solenoid Modulating Spring Armature Pilot COMPONENTS Control Pressure Bias Spring Pressure Compensating Chamber Main Poppet Spring Connection Port A Connection Port B GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
PRINCIPLE OF OPERATION • Forward Flow: Pressure at port A is higher than that at port B. Port A Port B GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
PRINCIPLE OF OPERATION • Forward Flow: Pressure compensating spring acts to balance pilot pin Pilot pin and armature displaced due to hydraulic imbalance Port A Port B GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
PRINCIPLE OF OPERATION • Forward Flow: Solenoid is activated and hydraulic fluid is drained to low pressure side Port A Port B GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
PRINCIPLE OF OPERATION • Forward Flow: Main poppet is displaced to a new equilibrium position allowing a direct connection between ports A and B Port A Port B GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
MATHEMATICAL MODELING • The mathematical modeling is based on the interaction of three subsystems: Electromagnetic Mechanical Hydraulic GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
MECHANICAL SYSTEM Modulating spring Armature mass Bias spring Pilot pin mass Piston mass Pressure compensating spring Main poppet mass GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
MECHANICAL SYSTEM • MODE 1 (closed): Pilot Armature & Piston Combined • Pilot-Armature-Piston Dynamics: • Main Poppet Dynamics: Main Poppet GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
MECHANICAL SYSTEM • MODE 2 (open): Pilot & Armature Piston Main Poppet GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
MECHANICAL SYSTEM • MODE 2 (open): • Pilot-Armature Dynamics: Pilot & Armature Main Poppet GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
MECHANICAL SYSTEM • MODE 2 (open): • Piston Dynamics: Piston Main Poppet GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
MECHANICAL SYSTEM • MODE 2 (open): Pilot & Armature • Main Poppet Dynamics: Piston Main Poppet GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
MECHANICAL SYSTEM • State Constraints - Main Poppet: - Pilot & Armature: Pilot & Armature Piston Main Poppet - Piston: GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
MECHANICAL SYSTEM • State Constraints - Main Poppet: GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
HYDRAULIC SYSTEM FLOW MODES: • Forward Flow • Reverse Flow Bi-Directional Capability Port A Port B GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
Pilot Head Chamber HYDRAULIC SYSTEM Control Pressure Chamber C 2 C 1 C A C 1 C 2 A B FORWARD FLOW DIAGRAM C B GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
Pilot Head Chamber HYDRAULIC SYSTEM Control Pressure Chamber C 2 C 1 C A C 1 C 2 A B REVERSE FLOW DIAGRAM C B GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
Pilot Head Chamber HYDRAULIC SYSTEM FORWARD FLOW: Control Pressure Chamber C A C 1 B C 2 A C B GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
HYDRAULIC SYSTEM A’ A’ View A’-A’ GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
Pilot Head Chamber HYDRAULIC SYSTEM Control Pressure Chamber C A C 1 C 2 A B Neglecting compressibility effects: C B GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
ELECTRO-MAGNETIC SYSTEM Rsol Vsol isol gmax GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
ELECTRO-MAGNETIC SYSTEM Rsol Vsol isol gmax GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
ELECTRO-MAGNETIC SYSTEM Rsol Vsol isol gmax Hysteresis GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
SIMULATION RESULTS • EHPV® Step Response (0 -90% capacity) GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
NON-LINEAR CONTROLLER Motor Speed Control: CONTROLLER EHPV Pump M M Load Motor Tank GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
NON-LINEAR CONTROLLER • Two Possibilities: Closed-Loop Control Vs. Open-loop Control • PI type • Look-up table • Generates duty cycle for PWM driver • Generate Kv for given pressure differential • Needs control variable measurement feedback GEORGIA TECH G. W. W. School of Mechanical Engineering • Trainable/tailored 10/7/2020
NON-LINEAR CONTROLLER • Closed-loop Control: Reference PI Controller EHPV Load Motor PWM Driver Sampled Error 100 0 % (Duty Cycle) PI Controller GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
NON-LINEAR CONTROLLER • Closed-loop Control: Set PWM Driver Regulate V Pull i Terminate GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
NON-LINEAR CONTROLLER • Response w/o PI: 50 Hz PWM 99% Duty cycle current regulated at 1[A] GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
NON-LINEAR CONTROLLER • Open-loop Control: Controller EHPV Load Motor Converter/ PWM Driver Look-Up. Table Controller GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
HARDWARE-IN-THE-LOOP • The Hardware-In-the-Loop (HIL) simulation facility located at the Intelligent Machine Dynamics Laboratory (IMDL) will be exploited for model validation, controller training, and control implementation. +12 Vdc Accumulator Hi-press. filter Flow meter Pressure transmitters B A M M EHPV Pressure relief valve Main Pump Crossover relief valve Lo-press. filter Load Tank Hydraulic Circuit for Single Valve Identification GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
HARDWARE-IN-THE-LOOP Hardware-In-the-Loop Facility at IMDL Hi-press. filter P A T B M M Main Pump Load 4 -EHPV® Tank Lo-press. filter Pressure transmitters Crossover relief valves Hydraulic Circuit for 4 -Way EHPV® Control Training GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
FUTURE WORK 1. Tune-up and test controllers. 2. Model validation for single and 4 -way directional valve arrangement. 3. Simulation and testing of four different flow metering modes, and study their effects. 4. Development of a more sophisticated and trainable nonlinear controller to compensate for inherent system non-linearities such as hysteresis. GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
CLOSURE • EHPV® design features, capabilities, and usage were exposed. • Based on the EHPV ®’s principle of operation, a complete non-linear model was developed. • Preliminary work on the Non-linear controller has been started. • The test facility Hardware-In-the-Loop (HIL) will be employed for model validation as well as for controller training and testing. • Future work has been established. GEORGIA TECH G. W. W. School of Mechanical Engineering 10/7/2020
- Slides: 40
