Electro-hydraulic Servo Control Research Articles

Research on PID Control of Electro-Hydraulic Position Servo Control System Based on SDO Optimization

Abstract. This article introduces the electro-hydraulic position servo control system, establishes its mathematical model and simulates with Simulink, then add PID module, use the empirical method to tune proportional, integral and differential parameters, it is found that adjustment is tedious, and performance improvement is limited. Then use the SDO tools for automatic optimization of PID control parameters, obtained a better simulation results. This tuning method is simple, easy to use, and with good results.

Design and Characteristic Analysis on Servo Amplifier

With the rapid development of the electro-hydraulic servo control technology, the application of electro-hydraulic servo valve has become more and more widely. Servo amplifier is an important part of the electro-hydraulic servo control system to drive and control servo valve. This essay introduces the principle and the function of servo-amplifier, and designs a servo amplifier with the functions of proportional amplifier, zero adjustment, feedback and current limitation. The performance analysis and validation for the servo amplifier are carried out by using simulation software EDA .On the basis of the simulation, the servo amplifier is fabricated, and its performance is tested. The results indicate that the servo amplifier has features of stable current output, good linearity, rapid response, and fully meet designing requirements.

Practical parallel position-force controller for electro-hydraulic servo drive using on-line identification

The paper presents selected issues of position-force control of electro-hydraulic servo system using adaptive methods. This kind of measure extends the capabilities of control system which uses only position measurements. Indirect adaptive control has allowed for the monitoring and updating the dynamic phenomena occurring in the drive.

Life Evaluation of Electro-Hydraulic Servo Valve Based on Wear Mechanism

Electro-hydraulic servo valve is the key component in electro-hydraulic servo control system, it has high reliable assemblies over a long period of time. This paper utilizes the accelerated degradation testing to evaluate their reliability and life. Firstly, the wear failure mechanism of electro-hydraulic servo valve is analyzed to determine. Then, by modeling the degradation process as a drift Brown Motion, this paper generated the reliability model of the electro-hydraulic servo valve. Finally, the maximum likelihood is used to estimate the degradation data of leakage from the test. The methodology in this paper is demonstrated and validated by reasonability of estimation of electro-hydraulic servo valve.

基于dSPACE半实物仿真的电液伺服控制研究

电液伺服控制算法一般采用软件编程的方法实现，其开发过程复杂，代码编写工作繁重，开发周期长。本文介绍了基于dSPACE的半实物仿真技术，利用MATLAB/Simulink的系统建模方法和dSPACE系统的软硬件环境，开发出以dSPACE为核心的电液伺服控制实验平台，在该平台上进行了电液伺服控制的试验研究，并利用ControlDesk进行了在线调参。实验结果验证了该实验平台的可靠性，并为研究更加复杂的控制算法提供了基础。 The electro-hydraulic servo control algorithms are always achieved in the way of program, but the period of the project is long, and the process is complex because of hard working programming. A dSPACE-based hardware-in-the-loop simulation system is presented in this paper to demonstrate the direct use of MATLAB/Simulink in real-time control. Through the combination of these tools, an electro-hydraulic servo control platform based on dSPACE system is developed. The research of electro-hydraulic servo control is performed on this platform, and by the use of ControlDesk we can tuned the control parameters on line to adjust the performance of real-time system. The experiment result verified the reliability of the platform, which offers foundation for the design of more complex control algorithms.

Simplified Adaptive Robust Motion Control with Varying Boundary Discontinuous Projection of Hydraulic Actuator

This paper deals with the high performance adaptive robust motion control of electrohydraulic servo system driven by dual vane hydraulic rotary actuator. The recently developed adaptive robust control theory is used to handle the nonlinearities and modelling uncertainties in hydraulic systems. Aside from the difficulty of handling parametric variations, the traditional adaptive robust controller (ARC) is also a little complicated in practice. To address these challenging issues, a simplified adaptive robust control with varying boundary discontinuous projection is developed to enhance the robustness of the closed-loop system, based on the features of hydraulic rotary actuator. Compared with previous ARC controller, the resulting controller has a simple algorithm for more suitable implementation and can handle parametric variations via nonlinear robust design. The controller theoretically achieves a guaranteed transient performance and final tracking accuracy in the presence of both parametric uncertainties and uncertain nonlinearities. Extensive simulation results are obtained for a hydraulic rotary actuator to verify the high performance nature of proposed control strategy.

Direct-Drive Differential Volume Control Electro-Hydraulic Servo Control System

Direct-drive volume control electro-hydraulic servo control system, derivation model of single-rod hydraulic cylinder system, pointed out that when the reciprocating motion characteristics are inconsistent. In order to solve this problem, proposed direct-drive differential volume control electro-hydraulic servo system design of its control system and analysis of system models. Through theoretical analysis, validate this proposed direct-drive bad dynamic volume control system, symmetric dynamic performance, improving control system reliability.

Research on the Low Velocity Accuracy Control of the Direct Drive Volume Control Electro-Hydraulic Servo System

The Direct Drive Volume Control (DDVC) Electro-hydraulic Servo System is a new Electro-hydraulic Servo System. With the development of its application, how to improve the trajectory tracking precision of the DDVC system in low velocity motions becomes more important in the field. So that, the level of the low velocity characteristic impacted the system become to an important subject. In this paper, the mathematical mode of AC asynchronism motor Direct Torque Control was established, and the simulation mode was built. In addition, the idealized model of the DDVC system which based on united simulation of AMEsim/Simulink was established, simulation was executed. In order to make the research available, the low velocity characteristic of the DDVC system was also analyzed, and the low velocity characteristic simulation model was built. Computer simulation validated that the friction is seriously influenced the system performance when the system working on the low velocity mode. An integral back stepping adaptive control law is designed to realize the friction compensation and load disturbance estimation. From the Lyapunov theory, the stability of the closed-loop system is proved. Simulation results show that LuGre friction in servo systems will lead to the effect of limit cycles and stick-slip. Moreover, the proposed compensation method can greatly reduce the effect and improve the system tacking accuracy and robustness.

Research on Electro-Hydraulic Force Servo Control System Based on Adaptive Neural Network Control Strategy

It is unchangeable fact that there is great stiffness spring flexible load in electro-hydraulic force servo control system, and there is low oscillation frequency second order differential link in the numerator of the transfer function. On the other hand, the frequency response ability of the system is influenced badly from the link and the system may oscillate easily even is instability. Aiming at this special performance of the electro-hydraulic force servo control system and its small open loop gain characteristic, the adaptive neural network control strategy is adopted to the controller of the electro-hydraulic force servo control system this special performance system in order to improve the dynamic performance of the system. The model of the system with the adaptive neural network control strategy is built and the simulation and experiment study is done. Comparing the control result of the controller with the adaptive neural network control strategy to the control result of the controller with the traditional PID, and from the results of simulation and experiment, we can know that the mathematic model of the electro-hydraulic force control system controlled by the adaptive neural network control strategy is correct, and we can find that the controller with the new designed control strategy can not only increase the frequency response ability of system, but also improve the precision of system, and the controller can quicken the response ability of the system obviously.

Dynamic Sliding Mode Control Scheme for Electro-Hydraulic Velocity Servo System

Pointing on uncertainties in the velocity servo system, caused by servo system cant model accurately, may cause the deterioration of the control quality of the electro-hydraulic servo system, and even lead to its instability. Sliding model control (SMC) strategy has been application in electro-hydraulic velocity servo control. Given that the quality and stability of servo system will be affected by the chartering phenomenon in the SMC, this paper proposes an approach to overcome the chattering: dynamic sliding mode control (DSMC). In this paper the mathematical model is established and the dynamic sliding mode controller is designed. Simulation and experiment indicated that: the proposed control strategy has good performance on velocity tracking and chattering reducing .The stability and control quality of the servo system are improved.

Research on High Power Direct Drive Differential Volume Control Electro-Hydraulic Servo System

For traditional direct drive volume control electro-hydraulic servo system, the servo motors rotary inertia is limited strictly, the speed of response is slow and the actuators reciprocating motion characteristics are not consistent. In order to solve these problems, this paper designs a kind of high power direct drive differential volume control electro-hydraulic servo system. It is instructive for design of hydraulic system which demands high output power, changes direction of motion frequently, needs high response frequency and requires the speed of reciprocating motion keep consistent.

Direct Drive Electro-hydraulic Servo Control System Design with Self-Tuning Fuzzy PID Controller

According to the nonlinear and time-varying uncertainty characteristics of direct drive electro-hydraulic servo control system, a self-tuning fuzzy PID control method with speed change integral and differential ahead optimizing operator is put forward by combining fuzzy inference and traditional PID control in this paper.The rule of fuzzy logic is designed, the membership function of the fuzzy subsets is determined and lookup table method is used to correcte the PID parameters in real-time. Finally the simulation is conducted with the typical input signal, such as tracking step, sine etc. The simulation results show that，the self-tuning fuzzy PID control system can effectively improve the dynamic characteristic when the system is out of the range of the operating point compared with the traditional PID control system, there is obvious improvement in the indexes of rapidity, stability and accuracy, and fuzzy self-tuning PID Control is more robust, and more suitable for direct drive electro-hydraulic servo system. DOI: http://dx.doi.org/10.11591/telkomnika.v11i6.2702 Full Text: PDF

Electro-Hydraulic Servo Road Simulation System Based on Fuzzy Control

The indoor road simulation test system test cycle is short, good reproducibility of the test results, confidentiality, etc., more and more attention in the vehicle industry. Analyzed by electro-hydraulic servo system of road simulation servo amplifier, electro-hydraulic servo valve, hydraulic cylinder and countertops and displacement transducer, The mathematical model of the system is established. The fuzzy model that comply with control law is designed. By unit step response simulation experiments, it is to be verified that the fuzzy control electro-hydraulic servo road simulation system is able to work better. It is a new attempt in roads simulation control strategy.

Influence of Parameters in Coupled Adaptive Self-Organizing Sliding-Mode Fuzzy Controller Using Volumetric Type Bending Machine

The dual-axial volumetric type bending machine is a coupled system and has significant structural interaction. Fuzzy controllers are widely applied in electro-hydraulic servo control systems. This paper proposes a coupled adaptive self-organizing sliding-mode fuzzy controller (ASOSMFC) to improve its level control performance. Parameters are important factor to the control effect. Experimented results indicate that owing to the unsymmetry of two subsystems of volumetric type bending machine, the adaptation gains of two subsystems must be different, to prevent the system divergent adaptation gains must be positive. Sliding plane gain will influence time response, synchronism and oscillation in steady state.

Research on Control Strategy of Oil Film Stiffness Control System of Hydrostatic Center Frame

Design a new type of electro-hydraulic servo control system of oil film in hydrostatic center frame, regulate and control oil film thickness adopting various controllable oil chambers, build mathematical models of control system and carry on system model identification and verification. Propose a control strategy about fuzzy sliding model variable structure, and it is applied in the model achieved by identification, adopt the method of fuzzy control system approximating equivalent control and design switching controller based on fuzzy control gain dynamic regulation, which could inhabit buffeting existing in sliding model variable structure control. Simulation results show that the controller can’t only effectively inhabit buffeting and reduce steady-state error, but also has strong robustness for structure parameter uncertainty.

Characteristic analysis of pump controlled motor speed servo in the hydraulic hoister

To imitate the real hydraulic hoist used in mines and enhance its control performance, a pump controlled motor speed servo (PCMSS) is presented. Mathematic models of PCMSS with and without a position loop are established and their dynamic characteristics are studied by simulation and experiments. Results indicate that PCMSS without a position loop is susceptible to interrupt and uncontrollable only depending on the external motor speed closed-loop, whereas PCMSS with a position loop can achieve high stability and speed precision relying on the internal position closed-loop in the pump and the external speed closed-loop. Therefore, to achieve higher performances for PCMSS, the displacement of a variable delivery pump should be independently adjusted while motor speed is fed back and controlled in closed-loop. Based on this theory, two electrohydraulic servo control schemes are proposed for automation reform of traditional hydraulic hoisters.

Study on the Speed Control System of Hydraulic Pump-Motor Based on PID Neural Network

Theoretical models of hydraulic pump-motor and electro-hydraulic servo control systems of hydraulic pumps were established and the system transfer function was derived In view of bad dynamic property, small damp, long transient time, low precision, nonlinearity and etc existing in the speed control system of Hydraulic Pump-Motor, a controller based on PID Neural Network was designed. The simulation results showed that the PID Neural Network controller has better dynamic property, load disturbance adaptability , robustness and cranking ability than traditional PID controller.

Research of the Electro-hydraulic Servo System Based on RBF Fuzzy Neural Network Controller

This article describes the composition and working principle of electro-hydraulic position servo control system, and establishes a systematic mathematical model. This article presents a controller which is based on Fuzzy neural networks for an electro-hydraulic speed governor. The design process of the RBF Fuzzy neural network control is introduced in detail. This controller which combines the advantages of the Fuzzy control and Neutral networks control can get the best PID parameters by self-adjustment on line. The simulation study proves that this control system has a better adaptability and can improve the control effect greatly.

The Development of Hydraulic Water Separator Used in Construction

Hydraulic water separator can realize the automatic control function by the use of pump-control speed electro-hydraulic servo control system. It can keep the centrifuge adapting to the changes of the water parameters fully with the real-time date collection of centrifugal speed according to different parameters including the density, viscosity, solid-phase content and particle size. It can achieve the best effect by the assurance that the centrifuge is always in the best condition.

Depth Control of an Electro-Hydraulic Servo System Based on Fractional Order PID

Electro-hydraulic servo systems (EHSS) are widely used in many industrial applications, and to determine the control strategies to exhibit high robustness and high precision remains the focus of attention. In order to improve the control performance of EHSS, a novel control method, based on fractional PID (FPID) controller, is proposed and designed for the EHSS. The transfer function of EHSS is constructed using first-principle method. The feasibility and availability of the proposed controller are examined by numerical simulation. The control performances of fractional FPID are well assessed based on performance indexes, including response time, tracking accuracy and robustness. The results of the simulation verify that FPID controller is of excellent control performance, and is suitable for the control of EHSS.