Dynamic Model and Control Design for a Nonlinear Hydraulic Actuator

2018 ◽  
Author(s):  
Carlos Borrás Pinilla ◽  
José Luis Sarmiento ◽  
Juan Felipe Ortiz
Keyword(s):  
Optimal Control ◽  
Dynamic Behavior ◽  
Pid Control ◽  
Nonlinear Dynamic ◽  
Feedback Linearization ◽  
Position Control ◽  
Settling Time ◽  
Hydraulic Systems ◽  
Hydraulic Actuator ◽  
And Control

Industrial hydraulic systems are complex, and show nonlinear dynamic behavior because of their nature. When it is not easy to deal with the nonlinear models, hydraulic systems are usually described by linear or linearized models around operating points. In this work a nonlinear dynamic and mathematic model for the position control of a double rod hydraulic actuator was developed. Three control strategies were implemented: PID control, optimal control (LQR) and control by Feedback Linearization. For the PID control and optimal control (LQR) strategies a linearized model of the hydraulic actuator was developed around a specific operating point, contrary to the Feedback Linearization control that have a wide operation range and the nonlinear model was used. These mathematical models were represented on Simulink environment, in order to compare and analyze the response and dynamic behavior. The optimal control (LQR) shows better settling time than the PID control, both without overshoot; and the Feedback Linearization show the best dynamic performance in terms of settling time with a little overshoot and disturbance tolerance.

Optimal Control Design of a Bimorph Optical Beam Deflector

2001 ◽  
Author(s):  
Chang-Po Chao ◽  
Jeng-Sheng Huang ◽  
Ching-Lung Ou Yung ◽  
Rong-Fong Fung
Keyword(s):  
Optimal Control ◽  
Position Control ◽  
Angular Position ◽  
Control Design ◽  
Element Model ◽  
Optical Beam ◽  
Optimal Feedback Control ◽  
Central Position ◽  
Control Effort ◽  
And Control

Abstract The optical beam deflector is composed of two piezoelectric layers, one sandwiched brass layer in the middle with both ends clamped and a mirror attached to the upper surface of the top piezoelectric layer in the central position. This structure is designed to deflect the mirror to a certain angular position by applying external voltage supply to piezo-layers. This study proposes an optimal angular position control scheme of the attached mirror. The governing partial differential equations are first derived for the ensuing analysis and control design, which is followed by the establishment of finite element model in ten nodes specified at some longitudinal points of the optical beam deflector. In order to achieve a faster convergent rate for the deflector to reach the desired angular position, the optimal control of LQ regulator with final states fixed is employed to explore the possibility of shorter transient response and less cost of control effort and states. The optimal feedback control is obtained based on solving a dynamic Riccati equation backward in time. The numerical simulation results are finally provided to validate the theoretical control design.

scholarly journals The Quadrotor Dynamic Modeling and Indoor Target Tracking Control Method

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Dewei Zhang ◽  
Hui Qi ◽  
Xiande Wu ◽  
Yaen Xie ◽  
Jiangtao Xu
Keyword(s):  
Target Tracking ◽  
Dynamic Model ◽  
Nonlinear Dynamic ◽  
Tracking Control ◽  
Feedback Linearization ◽  
Control Method ◽  
Measurement Unit ◽  
Control Algorithms ◽  
Nonlinear Dynamic Model ◽  
And Control

A reliable nonlinear dynamic model of the quadrotor is presented. The nonlinear dynamic model includes actuator dynamic and aerodynamic effect. Since the rotors run near a constant hovering speed, the dynamic model is simplified at hovering operating point. Based on the simplified nonlinear dynamic model, the PID controllers with feedback linearization and feedforward control are proposed using the backstepping method. These controllers are used to control both the attitude and position of the quadrotor. A fully custom quadrotor is developed to verify the correctness of the dynamic model and control algorithms. The attitude of the quadrotor is measured by inertia measurement unit (IMU). The position of the quadrotor in a GPS-denied environment, especially indoor environment, is estimated from the downward camera and ultrasonic sensor measurements. The validity and effectiveness of the proposed dynamic model and control algorithms are demonstrated by experimental results. It is shown that the vehicle achieves robust vision-based hovering and moving target tracking control.

scholarly journals A Flexible Adjustment and Control System for Hydraulic Machines

10.14311/1576 ◽  
2012 ◽  
Vol 52 (4) ◽  
Author(s):  
Daniel Banyai ◽  
Lucian Marcu
Keyword(s):  
Control System ◽  
Numerical Simulations ◽  
Dynamic Behavior ◽  
Hydraulic Control ◽  
Hydraulic Systems ◽  
Hydraulic Machines ◽  
Variable Displacement ◽  
And Control ◽  
Flow Power ◽  
Hydraulic Control System

Due to the advantages of hydraulic systems with variable displacement, it was necessary to design a control system that can adjust the pressure, flow, power or a combination of these features, that can be easily integrated into the pump body without changing its mechanical construction. The objective of this work was to study the dynamic behavior of this electro-hydraulic control system. To achieve these objectives, first the adjusting system was analyzed by numerical simulations, and then a stand was constructed for testing the performance of these adjustable pumps. It was shown that this control system is superior to existing systems.

scholarly journals Modelling & Position Control for Electro-Hydraulic System

2019 ◽  
Vol 8 (4) ◽  
pp. 3841-3845 ◽  
Keyword(s):  
Control System ◽  
Hydraulic System ◽  
Position Control ◽  
Industrial Applications ◽  
Hydraulic Systems ◽  
System A ◽  
Complex Process ◽  
Highly Nonlinear ◽  
Back Stepping Control ◽  
And Control

Electro-hydraulic systems (EHS) are widely used in industrial applications due to the high-power density and accuracy. However, EHS are highly nonlinear which makes its modelling and control aspects a complex process. In this paper, we present the modelling and position control for an electro-hydraulic system (EHS). The mathematical modelling is carried out considering the non-linearities like friction, discharge coefficient and load mass present in the system. A back-stepping control scheme is developed for maintaining the accuracy in the position control. The closed-loop stability of the proposed control system is analyzed with Lyapunov’s theory. The performance of the control system under the effect of bounded external uncertainties is validated with simulation study. The study indicates that the proposed controller gives an effective motion control in presence of the system uncertainties.

Discrete-Time H2-Optimal Control for Hydraulic Position Control Systems

2007 ◽  
Author(s):  
Yang Lin ◽  
Yang Shi ◽  
Richard Burton
Keyword(s):  
Optimal Control ◽  
Control Systems ◽  
Discrete Time ◽  
Ad Hoc ◽  
Position Control ◽  
Experimental Studies ◽  
Design Procedure ◽  
Design Parameters ◽  
Practical Applications ◽  
And Control

Hydraulic position control systems play an important role in industrial automation. This paper explores the application of discrete-time H2-optimal control for a hydraulic position control system (HPCS). By minimizing the H2-norm of the system, the discrete-time robust H2-optimal control both stabilizes the plant and minimizes the root-mean-square of the servo position error simultaneously. The intuitive nature of this advanced approach helps to manage the selection of design parameters, whereas, classical methods provide less insight into strategies for parameter selection and control design. Additionally, the powerful ability to address disturbances and uncertainty in the robust H2-optimal design offers a more direct alternative to the ad hoc and iterative nature of classical methods for the hydraulic servo position system. Computer simulations illustrate the design procedure and the effectiveness of the proposed method. Experimental studies which employ the H2-optimal control on a hydraulic positioning system are also conducted and the results show that the method is suitable for practical applications.

Simulation of Position Control and Flow Rate Match of Integrated Hydraulic Actuator Unit

2010 ◽  
Vol 118-120 ◽  
pp. 640-644
Author(s):  
Jian Xin Liu ◽  
Yu Liu ◽  
Ping Tan
Keyword(s):  
Flow Rate ◽  
Position Control ◽  
Control Method ◽  
Hydraulic Systems ◽  
Hydraulic Actuator ◽  
External Disturbances ◽  
Heavy Load ◽  
Actuation System ◽  
Oil Tank

This paper presents a kind of all-digital integrated hydraulic actuator (IHA) unit to drive heavy load object without centralized oil tank. In order to improve the control quality of the actuation system while eliminating or reducing the disturbance, and also to solve the problem of flow rate mismatch existed in IHA with single-rod cylinder actuator, a fuzzy PID PWM controller is suggested. Simulations on the integrated hydraulic actuator unit are carried out to evaluate the effectiveness of the proposed control method when applied to hydraulic systems with various external disturbances encountered in real working conditions. Simulation results are discussed and some conclusions are given.

scholarly journals Dynamic Modeling and Control of Electromechanical Coupling for Mechanical Elastic Energy Storage System

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Yang Yu ◽  
Zengqiang Mi
Keyword(s):  
Energy Storage ◽  
Dynamic Model ◽  
Elastic Energy ◽  
Nonlinear Dynamic ◽  
Feedback Linearization ◽  
Electromechanical Coupling ◽  
Storage System ◽  
Electromechanical System ◽  
Nonlinear Dynamic Model ◽  
And Control

The structural scheme of mechanical elastic energy storage (MEES) system served by permanent magnet synchronous motor (PMSM) and bidirectional converters is designed. The aim of the research is to model and control the complex electromechanical system. The mechanical device of the complex system is considered as a node in generalized coordinate system, the terse nonlinear dynamic model of electromechanical coupling for the electromechanical system is constructed through Lagrange-Maxwell energy method, and the detailed deduction of the mathematical model is presented in the paper. The theory of direct feedback linearization (DFL) is applied to decouple the nonlinear dynamic model and convert the developed model from nonlinear to linear. The optimal control theory is utilized to accomplish speed tracking control for the linearized system. The simulation results in three different cases show that the proposed nonlinear dynamic model of MEES system is correct; the designed algorithm has a better control performance in contrast with the conventional PI control.

Motion Control of a Nonlinear Single-Rod Hydraulic Actuator via Feedback Linearization

2009 ◽  
Author(s):  
Hamed Moradi ◽  
Kambiz Haji Hajikolaei ◽  
Mohammad Motamedi ◽  
G. Reza Vossoughi
Keyword(s):  
Nonlinear Dynamics ◽  
Feedback Linearization ◽  
Transfer Functions ◽  
Pole Placement ◽  
Hydraulic Systems ◽  
Hydraulic Actuator ◽  
Tracking Accuracy ◽  
Control Effort ◽  
Servo Valve ◽  
Highly Nonlinear

Hydraulic systems are extensively used in many engineering fields where a high degree of both accuracy and performance are required. Due to the highly nonlinear dynamics of hydraulic systems, applying high performance closed-loop controllers is complicated. In this paper, a single-rod hydraulic actuator is considered in which the dynamics of servo-valve is described by first and second order transfer functions. Nonlinear dynamics of hydraulic actuator is represented in the state space configuration. By manipulation of the input voltage to the servo-valve as the control effort, load position is controlled. A controller is designed based on the feedback linearization while its gains are determined using pole placement. Results show that the desired tracking performance and final tracking accuracy are achieved after applying the controller. Required control efforts, load position and velocity are compared for two distinct dynamics of the servo-valve.

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