Dynamic Property Simulations of Hydraulic Cylinder Based on Simulink

2010 ◽  
Vol 33 ◽  
pp. 22-27 ◽  
Author(s):  
Xiang Shu Jin ◽  
Bin Hui Rong ◽  
Xue Zhong Tang

The paper established the mathematical model of plunger-type hydraulic cylinder, founded the simulation model in the SIMULINK environment and solved its unit-step response, gave the hydraulic cylinder design parameter and the medium character’s influence to its unit-step response, summarized the intrinsic relations between parameters and the time domain index, provided the theory basis to optimize the hydraulic cylinder dynamic property. Conducting the research of the hydraulic cylinder system using SIMULINK has the outstanding characters such as the simple programming, the direct-viewing modeling, the highly effective simulation, it may reduce the design cycle greatly, reduce the design cost, enhance the product performance. The research conducted suggests this method may promote to the research of all the hydraulic package and hydraulic system.

2010 ◽  
Vol 136 ◽  
pp. 18-22
Author(s):  
Xiang Shu Jin ◽  
Shi Yan Ding ◽  
Xue Zhong Tang ◽  
Zhi Xi Hu

According to liquid continuity theory and the dynamic equilibrium conditions, established a piston-type hydraulic cylinder mathematical model. Founded the simulation model in the SIMULINK/ MATLAB environment and solved its unit-step response based on the relation between load and velocity, gave the hydraulic cylinder design parameter and the medium character’s influence to its unit-step response, summarized the intrinsic relations between parameters and the time domain index, provided the theory basis to optimize the hydraulic cylinder dynamic property. The hydraulic cylinder load - speed dynamic performance studies have shown that this method does not require complicated programming, simulation models can be visually established, and can greatly shorten the design cycle, reduce design costs, and improve product performance.


2013 ◽  
Vol 681 ◽  
pp. 214-218
Author(s):  
Da Zhi Huang ◽  
Qing Gui Zhou ◽  
Yuan Liang Zhang ◽  
Jin Song Chen

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.


Author(s):  
Yong Xue ◽  
JunHong Yang ◽  
JianZhong Shang ◽  
HuiXiang Xie

In order to improve the efficiency of multi-actuator mobile robots hydraulic system, this paper proposes a new kind of cylinder whose effective area is variable. The new cylinder has multi chambers which can be connected with each other or to a main system circuit by controlling switching valves. On the one hand, the new cylinder can make sure that the load pressure of all actuators is almost equal through varying effective area. On the other hand, the new cylinder can realize the flow recovery through that return chambers are connected with feeding chambers. Therefore, the new cylinder can reduce overall machine energy consumption by reducing throttling losses and allowing energy recovery. The performance of the new cylinder is analyzed through building the mathematical model. Based on the evaluated results, in order to further improve the performance of the load match of the cylinder and avoid the deflection of the main piston, the structure of the cylinder is optimized. Finally, an optimized cylinder is shown in this paper which has well performance of the load match.


Author(s):  
Mingjie Zhang ◽  
Ole Øiseth

AbstractA convolution-based numerical algorithm is presented for the time-domain analysis of fluidelastic instability in tube arrays, emphasizing in detail some key numerical issues involved in the time-domain simulation. The unit-step and unit-impulse response functions, as two elementary building blocks for the time-domain analysis, are interpreted systematically. An amplitude-dependent unit-step or unit-impulse response function is introduced to capture the main features of the nonlinear fluidelastic (FE) forces. Connections of these elementary functions with conventional frequency-domain unsteady FE force coefficients are discussed to facilitate the identification of model parameters. Due to the lack of a reliable method to directly identify the unit-step or unit-impulse response function, the response function is indirectly identified based on the unsteady FE force coefficients. However, the transient feature captured by the indirectly identified response function may not be consistent with the physical fluid-memory effects. A recursive function is derived for FE force simulation to reduce the computational cost of the convolution operation. Numerical examples of two tube arrays, containing both a single flexible tube and multiple flexible tubes, are provided to validate the fidelity of the time-domain simulation. It is proven that the present time-domain simulation can achieve the same level of accuracy as the frequency-domain simulation based on the unsteady FE force coefficients. The convolution-based time-domain simulation can be used to more accurately evaluate the integrity of tube arrays by considering various nonlinear effects and non-uniform flow conditions. However, the indirectly identified unit-step or unit-impulse response function may fail to capture the underlying discontinuity in the stability curve due to the prespecified expression for fluid-memory effects.


Actuators ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 95
Author(s):  
Ming Xu ◽  
Cheng Rong ◽  
Long He

Spiders rely on a hydraulic system to stretch their legs but use muscles to make their legs flex. The compound drive of hydraulics and muscle makes an integrate dexterous structure with powerful locomotion abilities, which perfectly meets the primary requirements of advanced robots. Inspired by this hydraulics-muscle co-drive joint, a novel flexible joint actuator was proposed and its driving characteristics were preliminarily explored. The bio-inspired flexible joint manifested as a double-constrained balloon actuator, which was fabricated by the composite process of 3D printing and casting. To evaluate its performance, the mathematical model was deduced, as well as the finite element analysis (FEA) model. A series of experiments on the rotation angles, driving forces, and efficiencies of the flexible joint were carried out and compared with the mathematical calculations and FEA simulations. The results show that the accuracy of the two theoretical models can be used to assess the joint actuator. The locomotion test of a soft arthropod robot with two flexible joints was also implemented, where the moving speed reached 22 mm/s and the feasibility of the proposed flexible joint applied to a soft robot was demonstrated.


Author(s):  
K. Harold Yae ◽  
Su-Tai Chern ◽  
Howyoung Hwang

Abstract Using forward and inverse dynamic analysis, the dynamic simulation of a backhoe has been compared with experiments. In the experiment, recorded were the configuration and force histories; that is, velocity and position, and force output from the hydraulic cylinder-all were measured in the time domain. When the experimental force history is used as driving force in the simulation, forward dynamic analysis produces a corresponding motion history. And when the experimental motion history is used as if a prescribed trajectory, inverse dynamic analysis generates a corresponding force history. Therefore, these two sets of motion and force histories — one set from experiment, and the other from the simulation that is driven forward and backward with the experimental data — are compared in the time domain. The comparisons are discussed in regard to the effects of variations in initial conditions, friction, and viscous damping.


2013 ◽  
Vol 278-280 ◽  
pp. 350-353 ◽  
Author(s):  
Feng Gao ◽  
Lin Jing Xiao ◽  
Shuai Guo ◽  
Hong Gang Ma

This paper mainly analyzes the hydraulic system principle during the monorail braking, and come to a conclusion that the spring stiffness and the throttle valve flow area are main factors affect the brake system. Then we use the MSC.EASY5 to modeling the hydraulic system, and simulate the unloading time of hydraulic cylinder under the spring force, the result shows that, the response time of a braking system can meet the requirement of the coal mine safety regulation, and change the flow area of throttle valve will affect the brake system.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Anis Allagui ◽  
Todd J. Freeborn ◽  
Ahmed S. Elwakil ◽  
Brent J. Maundy

Abstract The electric characteristics of electric-double layer capacitors (EDLCs) are determined by their capacitance which is usually measured in the time domain from constant-current charging/discharging and cyclic voltammetry tests, and from the frequency domain using nonlinear least-squares fitting of spectral impedance. The time-voltage and current-voltage profiles from the first two techniques are commonly treated by assuming ideal S s C behavior in spite of the nonlinear response of the device, which in turn provides inaccurate values for its characteristic metrics. In this paper we revisit the calculation of capacitance, power and energy of EDLCs from the time domain constant-current step response and linear voltage waveform, under the assumption that the device behaves as an equivalent fractional-order circuit consisting of a resistance R s in series with a constant phase element (CPE(Q, α), with Q being a pseudocapacitance and α a dispersion coefficient). In particular, we show with the derived (R s , Q, α)-based expressions, that the corresponding nonlinear effects in voltage-time and current-voltage can be encompassed through nonlinear terms function of the coefficient α, which is not possible with the classical R s C model. We validate our formulae with the experimental measurements of different EDLCs.


2021 ◽  
Vol 23 (1) ◽  
pp. 37-41
Author(s):  
Darko Babunski ◽  
◽  
Emil Zaev ◽  
Atanasko Tuneski ◽  
Laze Trajkovski ◽  
...  

Friction is a repeatable and undesirable problem in hydraulic systems where always has to be a tendency for its removal. In this paper, the friction model is presented through which the most accurate results are achieved and the way of friction compensation, approached trough technique presented with the mathematical model of a hydraulic cylinder of a hydro turbine wicket gate controlled by a servomechanism. Mathematical modelling of a servo mechanism and hydraulic actuator, and also the simulation of hydraulic cylinder as a part of a hydro turbine wicket gate hydraulic system where the stick-slip phenomenon is present between the system components that are in contact is presented. Applied results in this paper and the theory behind them precisely demonstrate under what circumstances the stick-slip phenomenon appears in such a system. The stick-slip effect is simulated using Simulink and Hopsan software and the analysis of the results are given in this paper. Removal of the stick-slip effect is presented with the design of a cascade control implemented to control the behaviour of the system and remove the appearance of a jerking motion.


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