A novel electro-hydraulic servo steering system for Ackermann steering of heavy multi-axle vehicle

2021 ◽  
pp. 095440702110633
Author(s):  
Zhizhong Zhang ◽  
Heng Du ◽  
Shumei Chen ◽  
Yuzheng Li ◽  
Han Wang
Keyword(s):  
Test Bench ◽  
Lagrange Equation ◽  
Experimental System ◽  
Steering System ◽  
Nonlinear Dynamic Model ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Cylinder Model ◽  
Hydraulic Servo ◽  
Simulation Results

Ackermann steering is important for the steering performance of heavy multi-axle vehicle. When Ackermann steering condition is not satisfied, it will lead to abnormal tire wear. Traditional trapezoidal mechanism of heavy multi-axle vehicle is a single degree of freedom (DOF) mechanism, which is difficult to completely realize Ackermann steering. In this paper, a new two DOF electro-hydraulic servo steering system (TDEHSSS) by using a variable length tie rod is proposed for solving the issue. First, a complex nonlinear dynamic model of TDEHSSS is established. This model includes the two DOF mechanical model based on a Lagrange equation, the valve-controlled double steering power cylinders model and the valve-controlled tie rod cylinder model. Then, a simulation model is built through MATLAB/Simulink and the simulation results show that TDEHSSS can realize the proposed requirement. At last, a test bench is founded to verify model. It is indicated that the simulation and experimental curves are consistent, showing that mathematical model is in accordance with the experimental system. This research is valuable for analyzing TDEHSSS, designing advanced controllers, and finally realizing Ackermann steering for heavy multi-axle vehicles.

Iterative Learning Control for a Class of Modeling Undesirable Single Degree of Freedom System

2014 ◽  
Vol 538 ◽  
pp. 379-382
Author(s):  
Wei Zhou ◽  
Bao Bin Liu
Keyword(s):  
Iterative Learning Control ◽  
Learning Algorithm ◽  
Learning Control ◽  
Iterative Learning ◽  
Degree Of Freedom ◽  
Control Input ◽  
Convergence Properties ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Simulation Results

A class of modeling undesirable single degree of freedom system is studied by using iterative learning control. The proposed iterative learning algorithm constantly updates the control input according to output error until the desired output occurred. So the system with designed controller can achieve perfect accuracy. We have proved convergence properties in iteration domain and simulation results demonstrate the effectiveness of the presented method.

Research on Modal Identification of Structures Using Robust Second-Order Blind Identification Technique

2013 ◽  
Vol 389 ◽  
pp. 712-720
Author(s):  
Jian Hua Du ◽  
Hong Wu Huang ◽  
Dian Dian Lan
Keyword(s):  
Second Order ◽  
Modal Identification ◽  
Mode Shapes ◽  
Blind Identification ◽  
Separation Algorithm ◽  
Single Degree Of Freedom ◽  
Second Order Statistics ◽  
Single Degree ◽  
Identification Technique ◽  
Simulation Results

The paper discusses the basic principle of blind source separation algorithm applying in structural modal identification. By improving the signal-whitening method, a robust second-order blind identification (RSOBI) algorithm is established on the basis of second-order statistics. The modal responses and mode shapes can be obtained using the RSOBI algorithm from the observed data of structures in time domain. Frequency and damping are estimated from the modal responses by traditional single degree of freedom methods. The simulation results show that the RSOBI algorithm has good performance in modal identification of structures.

scholarly journals Simulation Analysis of One Degree of Freedom Motion of Electromagnetic Spherical Joint based on Maxwell

2021 ◽  
Vol 2085 (1) ◽  
pp. 012014
Author(s):  
Haoran Wang ◽  
Fucong Liu ◽  
Sai Lou
Keyword(s):  
Mathematical Model ◽  
Simulation Analysis ◽  
Lagrange Equation ◽  
Degree Of Freedom ◽  
Spherical Joint ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Structure And Motion ◽  
The Mathematical Model ◽  
The Relationship

Abstract In order to improve the stiffness of the spherical joint of the robot, reduce the difficulty of manufacturing and the complexity of the control system, this paper proposed a method of spherical joint and digital drive of the robot based on the electromagnetic principle. Firstly, introduces the structure and motion principle of the spherical joint of the robot, establishes the mathematical model of the spherical joint and establishes the dynamic model according to the second Lagrange equation. after that, the relationship between the number of ampire-turns of the electromagnet on the spherical joint, the attitude Angle of the rotor and the force of the rotor was obtained by simulating the single degree of freedom of the joint based on Ansys maxwell and Matlab, which provided a basis for the realization of the digital drive of the spherical joint.

An Experimental Study of a Single-Degree-of-Freedom Impact Oscillator

2021 ◽  
Author(s):  
Shun Zhong ◽  
Jingyuan Tan ◽  
Zhicheng Cui ◽  
Tanghong Xu ◽  
Liqing Li
Keyword(s):  
Dynamical Behavior ◽  
Degree Of Freedom ◽  
Experimental Results ◽  
Physical Parameters ◽  
Impact Oscillator ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Design Choice ◽  
Wide Range ◽  
Simulation Results

Purpose. Impacts appear in a wide range of mechanical systems. To study the dynamical behavior introduced by impact in practical way, a single-degree-of-freedom impact oscillator rig is designed. Originality. A simple piece-wise linear system with symmetrical flexible constraints is designed and manufactured to carry out a wide range of experimental dynamic analysis and ultimately to validate piece-wise models. The new design choice is based on the following criteria: accuracy in representing the mathematical model, manufacturing simplicity, flexibility in terms of parameter changes and cost effectiveness as well avoidance of the delay introduced by the structure. Meanwhile, the new design provides the possibility of the applications of the complex control algorithms. Design/methodology/approach. The design process is described in detail. The initial experimental results of the rig as well as numerical simulation results are given. In this rig, the mass driven force is generated by electromagnet, which can be adjusted and control easily. Also, most of the physical parameters can be varied in a certain range to enhance flexibility of the system allowing to observe subtle phenomena. Findings. Compared with the simulation results, the designed rig is proved to be validated. Then, the initial experimental results demonstrate potentials of this rig to study fundamental impact phenomena, which have been observed in various engineering systems. They also indicate that this rig can be a good platform for investigating nonlinear control methods.

Method of Variable Parameter PID Control Applied for AMB System

2012 ◽  
Vol 150 ◽  
pp. 75-79
Author(s):  
Hao Nan Tan ◽  
Jian Sheng Zhang
Keyword(s):  
Mathematical Model ◽  
Pid Control ◽  
Pid Controller ◽  
Variable Parameter ◽  
Electromagnetic Theory ◽  
Single Degree Of Freedom ◽  
Variable Parameters ◽  
Single Degree ◽  
Simulation Results ◽  
Amb System

According to electromagnetic theory, A single degree of freedom mathematical model of AMB system was established. We design a variable parameter PID controller based on the model. And the simulation results express that the variable parameters PID controller was better in the lots of indicators compared with the traditional PID controller.

Piezoelectric Vibration Control of Translational Flexible Beams Using Switched Stiffness

2003 ◽  
Author(s):  
Arun Ramaratnam ◽  
Nader Jalili ◽  
Matt Grier
Keyword(s):  
Experimental Testing ◽  
Short Circuit ◽  
Degree Of Freedom ◽  
Flexible Beam ◽  
Flexible Beams ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Vibration Attenuation ◽  
Stiffness Method ◽  
Simulation Results

A switch-shunt stiffness method for vibration attenuation of flexible beams undergoing translational base motion with a laminated piezoelectric patch attachment is presented. The piezoelectric actuator, bonded on the top surface of the flexible beam, is switched between open and short circuit configurations. This results in a variable equivalent stiffness which, in turn, can remove energy from the overall system by directly affecting the stored potential energy in the flexible beam. Initially, a single degree of freedom system is considered for validation of the switched stiffness method. The method is then applied to a flexible beam with moving base, representing a Cartesian-type one-link robot manipulator. Simulation results demonstrate favorable vibration attenuation in both cases; the single degree of freedom oscillator and the cantilever flexible beam. Several variations of the switching mechanisms are explored in an effort to achieve optimal vibration characteristics. Experimental testing is currently under investigation for validation of the simulation results presented here.

A study on body sway of car-trailer combinations considering dry friction in steering subsystem

2021 ◽  
pp. 095440702110520
Author(s):  
Ning Zhang ◽  
Ke-Ke Geng ◽  
Tian Li ◽  
Jian-Hua Wu ◽  
Guo-Dong Yin
Keyword(s):  
Dynamic Stability ◽  
Dry Friction ◽  
Sliding Friction ◽  
Dynamic Instability ◽  
Lagrange Equation ◽  
Steering System ◽  
Body Sway ◽  
Rotational Inertia ◽  
Nonlinear Dynamic Model ◽  
Steering Characteristics

Considering the stability of vehicle system, static instability and dynamic instability are two different instability problems. Because of the dynamic coupling between car and trailer, the problem of dynamic stability of car-trailer combination (CTC) is more obvious. This instability is called body sway or flutter in engineering, its boundary is often described by dynamic critical speed ( vcrit). It has been proved by experiments that the steering system characteristics have an important impact on the dynamic stability of CTC, but the specific mechanism is not clear. In this paper, the characteristic and influence of steering subsystem are studied for the first time. Firstly, a 6-DOF nonlinear dynamic model of CTC is established by Lagrange equation. The steering subsystem characteristics, incl. stiffness, damping, rotational inertia, and dry friction, are considered in theoretical modeling. On this basis, the influences of steering characteristics, especially the dry friction, on vcrit and axle cornering stiffness of CTC are analyzed. Simulation results show that the vcrit can increase by 16% and 23.2% respectively via adjusting the steering stiffness and the sliding friction factor. Therefore, a fine selection of steering subsystem characteristics can effectively improve the dynamic stability and safety of CTC. The research results of this paper can provide reference for the design of steering system considering dynamic stability.

A Method for Selecting Velocity Filter Cutoff Frequency for Maximizing Impedance Width Performance in Haptic Interfaces

2013 ◽  
Author(s):  
Vinay Chawda ◽  
Ozkan Celik ◽  
Marcia K. O’Malley
Keyword(s):  
Cutoff Frequency ◽  
Haptic Interface ◽  
Haptic Interfaces ◽  
Simulation Experiments ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Simulation Based ◽  
Position Data ◽  
Simulation Results ◽  
Velocity Filtering

This paper analyzes the effect of velocity filtering cut-off frequency on the Z-width performance in haptic interfaces. Finite Difference Method (FDM) cascaded with a lowpass filter is the most commonly used technique for estimating velocity from position data in haptic interfaces. So far, there is no prescribed method for obtaining the FDM+filter cut-off frequency that will maximize the Z-width performance. We present a simulation based method to demonstrate that there exists such an ideal FDM+filter cut-off frequency, and that it can be predicted by numerical simulation. Experiments are conducted on a single degree-of-freedom linear haptic interface to validate the simulation results.

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