Stability Analysis and Optimal Design of High-Speed and High-Load Driving Mechanism With Joint Clearance Based on Multi-Body Dynamics

2013 ◽  
Author(s):  
Zenglei Zhang ◽  
Shijing Wu ◽  
Haibo Zhang ◽  
Jie Chen
Keyword(s):  
Optimal Design ◽  
Dynamic Characteristics ◽  
High Speed ◽  
High Load ◽  
Joint Clearance ◽  
Force Model ◽  
Driving Mechanism ◽  
Contact Method ◽  
Continuous Contact ◽  
Multi Body

High-speed and high-load driving mechanism with joint clearance presents strong nonlinear features which affects the dynamic characteristics of the mechanism. A single-degree-of-freedom multi-body model, including nine connecting links, three translation joints and ten revolute joints with clearance, is built with the continuous contact method based on research of dynamics theory about joint clearance. Furthermore, normal forces are calculated with a nonlinear continuous contact force model and tangential forces are calculated with the modified Coulomb friction model to simulate process of contact and collision. When the model is solved according to real operating condition, the results are compared with that of the model with ideal joints, finding that revolute joint clearance will create effects on velocity and especially great effects on acceleration of the driving mechanism. Moreover, different amounts and different sizes of the clearance are considered to research the influence on dynamic characteristics of the driving mechanism. Meanwhile, methods of optimal design are explored according to the parametric analysis computing results. Simulation methods and findings can act as guidance for further study of optimal design for high-speed and high-load driving mechanisms to reduce the negative effects of joint clearance.

Dynamics analysis of dual-axis positioning mechanism of satellite antenna with joint clearance

2014 ◽  
Vol 10 (1) ◽  
pp. 59-74
Author(s):  
Zheng Feng Bai ◽  
Yang Zhao ◽  
Jun Chen
Keyword(s):  
Dynamic Characteristics ◽  
Dynamic Performance ◽  
Engineering Application ◽  
Friction Model ◽  
Joint Clearance ◽  
Force Model ◽  
Dynamics Analysis ◽  
Satellite Antenna ◽  
Content Type ◽  
Continuous Contact

Purpose – The existence of clearance in joints of positioning mechanism is inevitable and the movements of the real mechanism are deflected from the ideal mechanism due to the clearances. The purpose of this paper is to investigate the effects of clearance on the dynamic characteristics of dual-axis positioning mechanism of a satellite antenna. Design/methodology/approach – The dynamics analysis of dual-axis positioning mechanism with clearance are investigated using a computational approach based on virtual prototyping technology. The contact model in joint clearance is established by using a hybrid nonlinear continuous contact force model and the friction effect is considered by using a modified Coulomb friction model. Then the numerical simulation of dual-axis positioning mechanism with joint clearance is carried out and four case studies are implemented for different clearance sizes. Findings – Clearance leads to degradation of the dynamic performance of the system. The existence of clearance causes impact dynamic loads, and influences the motion accuracy and stability of the dual-axis positioning mechanism. Larger clearance induces higher frequency shakes and larger shake amplitudes, which will deteriorate positioning accuracy. Practical implications – Providing an effective and practical method to analyze dynamic characteristics of dual-axis positioning mechanism of satellite antenna with joint clearance and describing the dynamic characteristics of the dual-axis positioning system more realistically, which improves the engineering application. Originality/value – The paper is the basis of mechanism design, precision analysis and robust control system design of dual-axis positioning mechanism of satellite antenna.

Dynamic characteristics of planar linear array deployable structure based on scissor-like element with joint clearance using a new mixed contact force model

2016 ◽  
Vol 230 (18) ◽  
pp. 3161-3174 ◽  
Author(s):  
Bo Li ◽  
San-Min Wang ◽  
Ru Yuan ◽  
Xiang-Zhen Xue ◽  
Chang-Jian Zhi
Keyword(s):  
Contact Force ◽  
Dynamic Characteristics ◽  
Dynamic Performance ◽  
Equations Of Motion ◽  
Contact Model ◽  
Joint Clearance ◽  
Force Model ◽  
Continuous Contact ◽  
Deployable Structure ◽  
Contact Force Model

This paper aims at investigating precisely the dynamic performance of deployable structure constituted by scissor unit mechanisms with clearance joint. Based on the motion law in real joints, the contact model is established using an improved Gonthier nonlinear continuous contact force model, and the friction effect is considered using LuGre model. Moreover, the resulting contact force is suitable to be included into the generalized force of the equations of motion of a multibody system and contributes to replace motion constraints. In the sequel of this process, the effect of joint clearance is successfully introduced into the dynamical model of scissor deployable structure and the dynamic characteristics of deployable structure with joint clearance are obtained using a direct default correction method, which can directly modify the coordinates and speed of the system to avoid the numerical results divergence. Also, the new hybrid contact force model of revolute joint clearance is verified through comparing with the original model. The numerical simulation results show that the improved contact model proposed here has the great merit that predicts the dynamic behavior of scissor deployable structure with joint clearance.

The Study on Dynamic Simulation of the Roller Gear Indexing Cam

2012 ◽  
Vol 503-504 ◽  
pp. 44-47
Author(s):  
Yan Song Liu ◽  
Wei He
Keyword(s):  
Optimal Design ◽  
Contact Mechanics ◽  
Dynamic Simulation ◽  
Dynamic Characteristics ◽  
High Speed ◽  
High Accuracy ◽  
New Method ◽  
Machining Accuracy ◽  
Body Dynamics ◽  
Multi Body

The roller gear indexing cam has irreplaceable superiority in the high-accuracy and high-speed indexing motion, but it can not keep the system’s good dynamic characteristics to improve machining accuracy of cam only. This paper studies the dynamic simulation of the roller gear indexing cam by means of virtual prototype technology, rigid multi-body dynamics, and contact mechanics, and the influences of this system’s parameters on dynamic responds of the mechanism. These works are valuable for designers, makers and users to optimal design, test, and make the mechanism, and give a new method for studying dynamics of roller gear indexing cam.

Development of High-Speed Response Electromagnetic Linear Actuator Using for Pneumatic Control Valve

2014 ◽  
Vol 532 ◽  
pp. 41-45 ◽  
Author(s):  
Myung Jin Chung
Keyword(s):  
Optimal Design ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Design Method ◽  
Control Valve ◽  
Design Parameters ◽  
Linear Actuator ◽  
Analytic Model ◽  
Electromagnetic Linear Actuator ◽  
Quadratic Programming Method

Analytic model of electromagnetic linear actuator in the function of electric and geometric parameters is proposed and the effects of the design parameters on the dynamic characteristics are analyzed. To improve the dynamic characteristics, optimal design is conducted by applying sequential quadratic programming method to the analytic model. This optimal design method aims to minimize the response time and maximize force efficiency. By this procedure, electromagnetic linear actuator having high-speed characteristics is developed.

A piezoelectric direct-drive servo valve with a novel multi-body contacting spool-driving mechanism: Design, modelling and experiment

2013 ◽  
Vol 228 (1) ◽  
pp. 169-185 ◽  
Author(s):  
Guan Changbin ◽  
Jiao Zongxia
Keyword(s):  
Piezoelectric Actuator ◽  
Dynamic Characteristics ◽  
Driving Mechanism ◽  
Direct Drive ◽  
Nonlinear Dynamic Model ◽  
Servo Valve ◽  
In Series ◽  
Dynamic Simulation Model ◽  
Pulling Force ◽  
Multi Body

Stack-type piezoelectric actuators, which usually consist of several ceramic layers connected in series, are widely used in piezoelectric direct-drive servo valves (PDDSV). However, poor pulling force capacity of this kind of actuators affects the performances of the direct-drive servo valves. This article presents a new type of PDDSV, whose spool-driving mechanism is composed of a set of independent parts that are not fixed together but are in contact with each other. This multi-body contacting spool-driving mechanism provides bidirectional movement of the spool by a preloaded stack-type piezoelectric actuator and a driving disc spring. This prevents the stack-type piezoelectric actuator from bearing the pulling force due to the inertia and friction of the spool. Design of the proposed servo valve is illustrated in detail and its characteristics are also predicted. Based on a nonlinear dynamic model of the multi-body contacting spool-driving mechanism, a comprehensive dynamic simulation model of the proposed PDDSV is established. Static and dynamic characteristics of the proposed PDDSV have been studied experimentally and good agreements between experimental and simulation results are observed. The dynamic performances of the proposed PDDSV are compared with the existing piezoelectric servo valves, which demonstrate that the proposed PDDSV has satisfactory dynamic characteristics for high-frequency applications.

Optimal Design for Partial Inertia Force Cancellation in Ultra High Speed Pressing Machine

2011 ◽  
Vol 291-294 ◽  
pp. 1909-1916 ◽  
Author(s):  
Jian Yu Bai ◽  
Zaihe Yu ◽  
Sen Lin Tong ◽  
Di Zheng
Keyword(s):  
Optimal Design ◽  
High Speed ◽  
Design Method ◽  
Inertia Force ◽  
Driving Mechanism ◽  
Kinematics Analysis ◽  
Ultra High Speed ◽  
Optimal Design Method ◽  
Inertia Forces ◽  
Manufacturing Machine

The severe vibration and noise caused by inertia forces within a manufacturing machine are often the bottleneck in increasing the manufacturing speed. Based on kinematics analysis of the applied driving mechanism, this paper proposes an optimal design method for partially canceling the inertia force in pressing machine by using limited number of weight-balancing blocks. The proposed method has been validated by simulations.

scholarly journals Evaluation of Joint Driving Torque and Finite Element Analysis in Articulate Robot through the simulation of Multi-Body Dynamics

2019 ◽  
Vol 8 (11) ◽  
pp. 682-686
Keyword(s):  
Experimental Data ◽  
Structural Analysis ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Simulation Software ◽  
Analysis Software ◽  
Characteristic Analysis ◽  
Element Analysis ◽  
Articulated Robots ◽  
Multi Body

Interest in high-speed articulated robots is increasing for product productivity expansion. High-speed articulated robots operate with rapid acceleration/deceleration moves, requiring dynamic characteristic analysis in the robot designing process. For this dynamic behavior analysis, simulation software is utilized, which supports product design verification and parts optimization. In analyzing the dynamic characteristics using the software, loading conditions can be obtained from experimental data or parts’ material characteristics. In a special case where data or experimental data on load conditions are hardly obtainable, multibody dynamics software is utilized. However, it is not easy to define an effective load and boundary conditions for systems with kinetically complicated connections. In order to solve such a problem, this present study investigated how to apply to structural analysis software the dynamic load found using dynamics and structural analysis software. In addition, the dynamic characteristics of high-speed articulated robots and robot link were assumed as a rigid body in implementing the dynamics analysis and structural analysis.

scholarly journals Analysis of dynamic characteristics for momentum wheel assembly with joint clearance

2018 ◽  
Vol 10 (12) ◽  
pp. 168781401881891
Author(s):  
Qi Wan ◽  
Geng Liu ◽  
Haitao Shi ◽  
Xiaofeng Zhang ◽  
Xin Ning
Keyword(s):  
Friction Coefficient ◽  
Angular Velocity ◽  
Dynamic Model ◽  
Contact Force ◽  
Dynamic Characteristics ◽  
Angular Acceleration ◽  
Friction Model ◽  
Joint Clearance ◽  
Force Model ◽  
Coulomb’S Friction

To study the effects of joint clearance on the dynamic characteristics of the momentum wheel assembly of satellite antennas, the computational dynamic model of momentum wheel assembly is developed in this article, considering influencing factors including rotor imbalance, flexibility, and joint clearance between rotor and bearing. The nonlinear contact force model and modified Coulomb’s friction model are adopted in the joint clearance of the dynamic model, and then the influence of clearance size, driving angular velocity, and friction coefficient on the dynamic behaviors of momentum wheel assembly is further analyzed. The results indicate that the existence of joint clearance has extraordinary obvious effects on the dynamic system characteristics, which causes the adjusting time to reach a state of continuous fluctuation to become longer compared to that of the ideal joint, and the angular acceleration and contact force appear to have high impulse peaks. The larger the clearance, the more obvious the fluctuation amplitude of the response and the slighter the shaking frequency. Furthermore, increasing the driving angular velocity can cause system oscillation with high frequency and large amplitude. Moreover, the smaller the friction coefficient, the poorer the accuracy and stability of the system, which leads to deviation from ideal performance. Therefore, it is important to consider the joint clearance to predict the dynamic characteristics of momentum wheel assembly.

Non-linear continuous-contact-force model for low-speed front-to-rear vehicle impact

2007 ◽  
Vol 221 (10) ◽  
pp. 1197-1208 ◽  
Author(s):  
I Han
Keyword(s):  
Contact Force ◽  
High Speed ◽  
Force Model ◽  
Injury Biomechanics ◽  
Low Speed ◽  
Continuous Contact ◽  
Acceleration Pulse ◽  
Rear Impact ◽  
Contact Force Model ◽  
Non Linear

The most common kind of vehicular accident is the low-speed front-to-rear impact that results in a high proportion of insurance claims and whiplash-associated disorders. The low-speed collisions have specific characteristics that differ from high-speed collisions and must be treated differently. This paper presents a fundamental non-linear continuous-contact-force model for the low-speed front-to-rear impact to simulate the accelerations, the velocities, and the contact force as functions of time. A smoothed Coulomb frictional force is used to represent the effect of braking, which was found to be significant in simulating low-speed front-to-rear impact. The intervehicular contact force is modelled using non-linear damping and spring elements with coefficients and exponents. This paper presents a method of estimating analytically the stiffness and damping coefficients. The exponent of the non-linear contact force model was determined to match the overall acceleration pulse shape and magnitude. The model can be used to determine ∇ V values and peak accelerations for the purpose of accident reconstruction and for injury biomechanics studies.

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