scholarly journals The Influence of Valve-Pump Weight Ratios on the Dynamic Response of Leaking Valve-Pump Parallel Control Hydraulic Systems

2018 ◽  
Vol 8 (7) ◽  
pp. 1201 ◽  
Author(s):  
Haigang Ding ◽  
Jiyun Zhao ◽  
Gang Cheng ◽  
Steve Wright ◽  
Yufeng Yao
Keyword(s):  
Dynamic Response ◽  
Hydraulic System ◽  
Weight Ratio ◽  
Open Loop ◽  
Hydraulic Systems ◽  
Variable Speed ◽  
Weight Factors ◽  
Wide Range ◽  
Parallel Control ◽  
Valve Control

A new leaking valve-pump parallel control (LVPC) oil hydraulic system is proposed to improve the performance of dynamic response of present variable speed pump control (VSPC) system, which is an oil hydraulic control system with saving energy. In the LVPC, a control valve is operating at leaking status, together with a variable speed pump, to regulate the system flow of hydraulic oil simultaneously. Therefore, the degree of valve control and pump control can be adjusted by regulating the valve-pump weight ratio. The LVPC system design, mathematical model development, system parameter and control performance analysis are carried out systematically followed by an experimental for validation process. Results have shown that after introducing the valve control, the total leakage coefficient increases significantly over a wide range with the operating point and this further increases damping ratios and reduces the velocity stiffness. As the valve-pump weight ratio determines the flow distribution between the valve and the pump and the weight factors of the valve and/or the pump controls determines the response speed of the LVPC system, thus if the weight factors are constrained properly, the LVPC system will eventually have a large synthetic open-loop gain and it will respond faster than the VSPC system. The LVPC will enrich the control schemes of oil hydraulic system and has potential value in application requiring of fast response.

Simulation Analysis of Rotary Steering Pump-Control Hydraulic System

2013 ◽  
Vol 295-298 ◽  
pp. 1995-2000
Author(s):  
Guang Fu Chen ◽  
Xiao Xian Yao ◽  
Si Bao Li
Keyword(s):  
Mathematical Model ◽  
Comparative Analysis ◽  
Input Signal ◽  
Hydraulic System ◽  
Simulation Analysis ◽  
Harsh Environment ◽  
Hydraulic Systems ◽  
New Form ◽  
The Mathematical Model ◽  
Valve Control

The traditional valve control hydraulic systems have serious challenges in the harsh environment underground. The mathematical model of this new form of "motor - quantitative pump" controll system was established and simulated by using AMESIM software in this paper. According to the results of comparative analysis of the orifice parameters and the way to input signal, related parameters was determined, which can meet the characteristics of the system.

Design and Characteristic Analysis of Variable Speed Hydraulic System

2012 ◽  
Vol 591-593 ◽  
pp. 179-182
Author(s):  
Yi Jun Zhou ◽  
Jun Xu
Keyword(s):  
Hydraulic System ◽  
Systems Design ◽  
Test System ◽  
Open Loop ◽  
Hydraulic Control ◽  
Variable Speed ◽  
Characteristic Analysis ◽  
Hydraulic Test ◽  
Loop Control ◽  
Detection Technology

The motor variable frequency speed control technology applied to the traditional hydraulic system based on variable speed hydraulic transmission principle with The PLC technology, hydraulic control, detection technology and configuration of organic, it combine PLC as the core of the lower machine control components, PC as the control, researched the variable speed hydraulic test system hardware, software and control systems design. The experiments were performed, realized the variable speed hydraulic experimental platform for open loop control and variable speed hydraulic system parameters real-time monitoring and dynamic display. It overcomes some of the shortcomings of the conventional hydraulic system, improved the efficiency, the hydraulic system run more smoothly and reduce noise. The experiments show that the variable speed hydraulic test bench run well and achieve the purpose.

Gain-Scheduled Position Control of a Pneumatic Muscle Actuator

2021 ◽  
Author(s):  
Matthew Cotton ◽  
Andrew Plummer
Keyword(s):  
Position Control ◽  
Weight Ratio ◽  
Experimental System ◽  
Open Loop ◽  
Tracking Performance ◽  
Precise Position ◽  
Linear Controller ◽  
Highly Nonlinear ◽  
Wide Range ◽  
Gain Scheduled

Abstract Pneumatic artificial muscles (PAMs) are high power-to-weight ratio actuators with considerable potential in biomimetic robotics and orthotics due to their similarities with human skeletal muscle. However, precise position control is difficult to achieve due to the highly nonlinear nature of the actuators and the pneumatic systems driving them. A wide range of nonlinear controllers have been proposed to-date, but none have been shown to be entirely satisfactory, and are often optimised for only one region of the PAM’s travel. In this paper, a gain-scheduled position controller is designed that aims to achieve equal tracking performance across the entire travel of the PAM. Selected scheduling variables include actuator displacement and error direction, with controller gains defined by ‘normalisation curves’ determined by data from open-loop characterisation tests. The experimental system consists of a Festo PAM, a pair of on-off valves driven by pulse-width modulated signals, and sensors for PAM displacement and pressure. Controller performance is tested using several dynamic position tracking tests, and the results are compared to an equivalent linear controller. The gain-scheduled approach successfully counteracts the differing inflation / deflation dynamics of the system, showing improved tracking performance over the linear controller with considerably less variability due to operating region.

Digital Hydraulic System Using Pumps and On/Off Valves Controlling the Actuator

2014 ◽  
Author(s):  
Cristiano Cardoso Locateli ◽  
Paulo Leonel Teixeira ◽  
Edson Roberto De Pieri ◽  
Petter Krus ◽  
Victor Juliano De Negri
Keyword(s):  
High Power ◽  
Power Dissipation ◽  
Hydraulic System ◽  
Control Method ◽  
Weight Ratio ◽  
Speed Control ◽  
High Energy ◽  
Hydraulic Systems ◽  
Low Efficiency ◽  
Smooth Transitions

Hydraulic systems employed in several industrial and mobile applications present significant advantages, such as a high power-to-weight ratio and fast dynamic response. However, these systems have low efficiency due to high power dissipation. A recent concept called “digital hydraulics” comprises particularities that create opportunities for a reduction in load loss. This paper proposes a configuration and control method for actuator speed control based on the principles of digital hydraulics. In this context, several fixed displacement units and on/off valves are connected directly to the actuators without throttling valves. The system studied here presents three operation methods (pump mode, motor mode and idle mode), which allows discrete valves to replace continuous or flow control valves in order to control the actuator. Furthermore, a fixed or variable displacement pump with large displacement is replaced by several small, fixed displacement units. Simulations are performed with a co-simulation technique using AMESim and MATLAB. The actuator speed, inlet and outlet pressures on the fixed displacement units and flow rate in the circuit lines are analysed. Preliminary simulation results exhibit smooth transitions between speed levels, adequate dynamic performance, low power dissipation and high energy-storage capacity. A specific limitation of this technology is the obtained actuator discrete speed. The main contributions of this research are the development of a digital hydraulic system configuration and its control strategy, which allows speed control of hydraulic actuators and provides the capacity to store energy.

Transmission of Fluid Power by Pulsating-Flow (P-F) Concept in Hydraulic Systems

1966 ◽  
Vol 88 (2) ◽  
pp. 316-321 ◽  
Author(s):  
Cheng-Kuo Weng
Keyword(s):  
Dynamic Response ◽  
Hydraulic System ◽  
Power Transmission ◽  
Pulsating Flow ◽  
Fluid Power ◽  
Experimental Investigations ◽  
System Efficiency ◽  
Test Results ◽  
Hydraulic Systems ◽  
Line Loss

Theoretical and experimental investigations have been made on fluid-power transmission in hydraulic systems by pulsating flow. In particular, the system efficiency and the viscosity effect on the dynamic response of pulsating flow in the fluid line have been studied. Test results on the fluid-line dynamic response and on the system efficiency that obtained from the line-loss test setup and the miniaturized P-F hydraulic system setup, respectively, are presented.

Design and Analysis of a Two-Valve Control Hydraulic System for Controllable Pitch Propeller

2012 ◽  
Vol 468-471 ◽  
pp. 122-126
Author(s):  
Chang Jun Zhang ◽  
Jing Li ◽  
Hong Gang Jiang ◽  
Yun Chen ◽  
Yao Bao Yin
Keyword(s):  
Hydraulic System ◽  
Simulation Analysis ◽  
Control Valve ◽  
Proportional Valve ◽  
Directional Control ◽  
Parallel Control ◽  
The Relationship ◽  
Valve Control ◽  
Control Accuracy ◽  
Directional Control Valve

This paper designs a two-valve control hydraulic system for controllable pitch propeller which consists of an electro-hydraulic directional control valve and a proportional directional control valve. The parallel control strategy is proposed and respective controllers are determined for the system. It yields out the relationship between the control parameters and valves characteristics by modeling and simulation analysis. Also the influence of the proportional valve flow rate on pitch control accuracy is discussed.

Parametric Study of a Fluidic Artificial Muscle Actuated Electrohydraulic System

2016 ◽  
Author(s):  
Edward Chapman ◽  
Tyler Jenkins ◽  
Matthew Bryant
Keyword(s):  
Hydraulic System ◽  
Artificial Muscle ◽  
Small Scale ◽  
Artificial Muscles ◽  
Operating Pressure ◽  
Control Force ◽  
Hydraulic Systems ◽  
Force Output ◽  
Injury Rehabilitation ◽  
Wide Range

Fluidic artificial muscles have the potential for a wide range of uses; from injury rehabilitation to high-powered hydraulic systems. Their modeling to date has largely been quasi-static and relied on the operator to adjust pressure so as to control force output and utilization while little work has been done to analyze the kinematics of the driving-systems involved in their operation. This paper utilizes an established electro-hydraulic model to perform a study of the components of a fluidic artificial muscle actuated climbing robot. Its purpose is to determine the effect of the robotic subsystems on function and efficiency for a small-scale system in order to extrapolate more general design and analysis schemes for future use. Its results indicate that important aspects to consider in design of the hydraulic system are system payload, operating pressure, pump selection, and FAM construction.

A Variable Speed Control Hydraulic System Based on BP Neural Network PID Controller

2011 ◽  
Vol 101-102 ◽  
pp. 439-442
Author(s):  
Fang Ping Huang ◽  
Tian Hao Peng
Keyword(s):  
Neural Network ◽  
Bp Neural Network ◽  
Hydraulic System ◽  
Pid Controller ◽  
Good Control ◽  
Hydraulic Systems ◽  
Variable Speed ◽  
Control Effect ◽  
Research Results ◽  
Neural Network Pid

The variable speed hydraulic systems have many advantages, and research about this field in recent years has developed rapidly. In this paper, a variable speed hydraulic system is studied using BP Neural Network PID controller. The research results show that using BP Neural Network PID controller can achieve good control effect.

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