Accurate Motion Control of a Direct-drive Hydraulic System with an Adaptive Nonlinear Pump Flow Compensation

The multiple degrees of freedom mechanical arm of sampling machine for coal at railway carriage is driven by hydraulic press. It is a kind of joint. During working, the sampling head not only keeps in its poses, but also moves along a straight path. The mechanical arm’s motion is resolved into three independent motion systems, foundation rotation, straight motion of 3 degrees of freedom kinematics chain, and servo control system of the sampling head. A group of motion equations is set up. According to the reversion theory and optimization method, the motion control model is built up in order to reappear the motion track. The method is efficient to solve the motion control problem. And the result of driving curve is more suitable for the hydraulic system. This method is useful for motion intelligent control of different kinds of joint manipulator.

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Novel Concept for Electro-Hydrostatic Actuators for Motion Control of Hydraulic Manipulators

Energies ◽

10.3390/en14206566 ◽

2021 ◽

Vol 14 (20) ◽

pp. 6566

Author(s):

Konrad Johan Jensen ◽

Morten Kjeld Ebbesen ◽

Michael Rygaard Hansen

Keyword(s):

Motion Control ◽

Hydraulic Manipulators ◽

Path Control ◽

Differential Flow ◽

Hydraulic Cylinders ◽

Hydraulic Crane ◽

Flow Compensation ◽

Novel Concept ◽

Four Quadrant ◽

Similar Dynamic

Self-contained hydraulic cylinders have gained popularity in the recent years but have not been implemented for high power articulated hydraulic manipulators. This paper presents a novel concept for an electro-hydrostatic actuator applicable to large hydraulic manipulators. The actuator is designed and analyzed to comply with requirements such as load holding, overload handling, and differential flow compensation. The system is analyzed during four quadrant operation to investigate energy efficiency and regenerative capabilities. Numerical simulation is carried out using path control and 2DOF anti-swing of a hydraulic crane as a load case to illustrate a real world scenario. A comparison with traditional valve-controlled actuators is conducted, showing significantly improved efficiency and with similar dynamic response, as well as the possibility for regenerating energy.

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Piezoelectric Actuation to Reduce Pump Flow Ripple

ASME/BATH 2019 Symposium on Fluid Power and Motion Control ◽

10.1115/fpmc2019-1611 ◽

2019 ◽

Author(s):

Nathan Hagstrom ◽

Michael Harens ◽

Arpan Chatterjee ◽

Matthew Creswick

Keyword(s):

Hydraulic System ◽

Piezoelectric Actuators ◽

Piezoelectric Actuation ◽

Flow Ripple ◽

Micro Scale ◽

Pump Flow ◽

Swash Plate ◽

Pump Output ◽

Novel Method ◽

Cylinder Method

Abstract Pump flow ripple is a source of noise and pressure fluctuation that can result in unwanted behavior and failure of a hydraulic system. The intent of this paper is to present and model a novel method to reduce flow ripple using piezoelectric actuators, which are currently limited to applications in micro-scale pumps. The paper presents two methods for reducing pump flow ripple in a hydraulic system. The first method uses a piezoelectric actuated valve which governs the pump displacement. The second method employs a piezoelectric actuated cylinder that acts directly on the outlet fluid to reduce the flow ripple from the pump. Method one was not able to reduce the flow ripple due to the bandwidth limitations of the swash plate actuation cylinder. Method two was able to reduce the flow ripple significantly. Further improvements on method two were achieved by increasing the number and size of the piezoelectric actuated cylinders acting at the pump outlet. After optimization, it was found that method two was found to decrease pump ripple by up to 53.5% from the baseline pump output. Though method one is largely unsuccessful, it is found that method two is successful and becomes more effective as the number and size of the piezoelectric actuated cylinders increase.

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Motion Control of Ultra-High-Speed Manipulator with a Flexible Link Based on Dynamically Coupled Driving

Journal of Robotics and Mechatronics ◽

10.20965/jrm.2006.p0598 ◽

2006 ◽

Vol 18 (5) ◽

pp. 598-607 ◽

Cited By ~ 1

Author(s):

Tomoari Maruyama ◽

◽

Chunquan Xu ◽

Aiguo Ming ◽

Makoto Shimojo

Keyword(s):

Motion Control ◽

High Speed ◽

Wrist Joint ◽

High Accuracy ◽

Human Motion ◽

Golf Club ◽

Direct Drive ◽

Flexible Link ◽

Ultra High Speed ◽

Drive Motor

We have developed a golf robot whose swing simulates human motion. The design concept is to realize ultra-high-speed dynamic manipulation using a dexterous mechanism. The robot consists of a shoulder joint with a high-power direct-drive motor and a wrist joint with a low-power direct-drive motor. High-speed golf swings are realized by a sort of motion control, called dynamically-coupled driving which compensates for the lack of drive in the wrist joint. In this paper a new model accounting for golf club flexibility with all parameters identified in experiments was developed. Based on this, we generated and implemented trajectories for different criteria. Experimental results confirmed the high accuracy of motion control and the feasibility of golf club flexibility in ultra-high-speed manipulation.

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