Disturbance Observer Based Speed Control of a Variable Displacement Pump-Driven-Motor System with Impedance Torque Regulation

Losses in control valves drag down the average overall efficiency of electrohydraulic systems to only about 22% from nearly 75% for standard pump-motor sets. For achieving higher energy efficiency in slower systems, direct pump control replacing fast-response valve control is being put in place through variable-speed motors. Despite the promise of a quicker response, displacement control of pumps has seen slower progress for exhibiting undesired oscillation with respect to the demand in some situations. Hence, a mechatronic simulation-based design is taken up here for a variable-displacement pump–controlled system directly feeding a double-acting single-rod cylinder. The most significant innovation centers on designing an axial-piston pump with an electrohydraulic compensator for bi-directional swashing. An accumulator is conceived to handle the flow difference in the two sides across the load piston. A solenoid-driven sequence valve with P control is proposed for charging the accumulator along with setting its initial gas pressure by a feedforward design. Simple proportional–integral–derivative control of the compensator valve is considered in this exploratory study. Appropriate setting of the gains and critical sizing of the compensator has been obtained through a detailed parametric study aiming low integral absolute error. A notable finding of the simulation is the achievement of the concurrent minimum integral absolute error of 3.8 mm s and the maximum energy saving of 516 kJ with respect to a fixed-displacement pump. This is predicted for the combination of the circumferential port width of 2 mm for the compensator valve and the radial clearance of 40 µm between each compensator cylinder and the paired piston.

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Robust speed control of a permanent magnet synchronous motor system

2016 Chinese Control and Decision Conference (CCDC) ◽

10.1109/ccdc.2016.7531547 ◽

2016 ◽

Author(s):

Yang Zhao ◽

Lili Dong

Keyword(s):

Permanent Magnet ◽

Motor System ◽

Permanent Magnet Synchronous Motor ◽

Speed Control ◽

Synchronous Motor

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A novel sliding mode single-loop speed control method based on disturbance observer for permanent magnet synchronous motor drives

Advances in Mechanical Engineering ◽

10.1177/1687814018815271 ◽

2018 ◽

Vol 10 (12) ◽

pp. 168781401881527 ◽

Cited By ~ 2

Author(s):

Xudong Liu ◽

Ke Li

Keyword(s):

Permanent Magnet ◽

Disturbance Observer ◽

Control Structure ◽

Control Method ◽

Sliding Mode ◽

Permanent Magnet Synchronous Motor ◽

Speed Control ◽

Synchronous Motor ◽

Motor Drives ◽

Sliding Mode Controller

A novel speed control method based on sliding mode control and disturbance observer is studied for permanent magnet synchronous motor drives. Different from the conventional speed and current cascade control structure in the field-oriented vector control, the new controller adopts the single-loop control structure, in which the speed and quadrate axes current controllers are combined together. First, a multiple-surface sliding mode controller is designed for the speed control system of permanent magnet synchronous motor. Although the sliding mode controller has the strong robustness for the matched disturbance in the system, it still cannot deal with mismatched disturbance effectively, such as external load disturbance and some parameter variations. Thus, the disturbance observer is introduced to estimate the disturbance in the motor, which is designed by combining the proposed sliding mode controller. Finally, the effectiveness is tested under various conditions by both simulation and experiment. The results show that the designed controller has the fast transient response and robustness under different operating conditions.

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Robust Nonlinear Control of a Novel Indexing Valve Plate Pump: Simulation Studies

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.1514668 ◽

2002 ◽

Vol 124 (4) ◽

pp. 613-616 ◽

Cited By ~ 2

Author(s):

X. Zhang ◽

S. S. Nair ◽

N. D. Manring

Keyword(s):

Pressure Control ◽

Plate Motion ◽

Nonlinear Simulation ◽

Response Characteristics ◽

Model Free ◽

Swash Plate ◽

Displacement Pump ◽

Variable Displacement ◽

Robust Adaptive ◽

Improved Performance

A robust adaptive pressure control strategy is proposed for a novel indexing variable-displacement pump. In the proposed approach, parametric uncertainties and unmodeled dynamics are identified to the extent possible using a model free learning network and used to decouple the dynamics using physical insights derived from careful reduced order modeling. The swash plate motion control is then carefully designed to provide the desired pressure response characteristics showing improved performance with learning. The proposed control framework and designs are validated using a detailed nonlinear simulation model.

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