Modeling and Simulation of Aligning Process for Alignment Mechanism of Large Aircraft Component

2012 ◽  
Vol 160 ◽  
pp. 351-355
Author(s):  
Zheng Ying ◽  
Ying Lin Ke
Keyword(s):  
Dynamic Models ◽  
Dynamic Performance ◽  
Kinematic Model ◽  
Force Model ◽  
Continuous Contact ◽  
Contact Force Model ◽  
Aircraft Component ◽  
Alignment Mechanism ◽  
Kinematic Joint ◽  
Large Aircraft

The dynamic performance of alignment mechanism of large aircraft component is directly associated with the structure and clearance of spherical joints. To accurately evaluate this influence, kinematic and dynamic models of spherical joints are developed. Firstly, a kinematic model of spherical joints is established. Secondly, a dynamic model of spherical joints is derived from the kinematic model and continuous contact force model. Finally, simulations of alignment mechanism of large aircraft component are carried out for typical moving trajectories. The influences of moving trajectory on the dynamic performance of mechanism are analysed. The simulation results are also applicable to similar mechanism design, moving trajectory planning and kinematic joint wear forecasting.

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.

Modeling Planar Joints With Clearance Between the Guide and Roller in Mechanisms

2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Yunkai Gao ◽  
Yuexing Duan ◽  
James Yang ◽  
Zhe Yuan ◽  
Chao Ma
Keyword(s):  
Experimental Data ◽  
Contact Force ◽  
Convex Surface ◽  
Dynamic Performance ◽  
Kinematic Model ◽  
Force Model ◽  
Damping Force ◽  
Contact Force Model ◽  
Dynamic Performance Analysis ◽  
Rms Errors

Abstract In mechanisms, the guide and roller form joints with clearance and the roller may make contact with the convex surface or concave surface of the guide. Correctly modeling this type of joint is critical in a mechanism's dynamic performance analysis. This paper proposes a contact kinematic model and a hybrid contact force model for the planar joint and investigates both the convex and concave contact cases. The contact kinematic model is derived from the relative motion between the guide and roller and the hybrid contact force model consists of an elastic force and a damping force. The sliding door mechanism is used as an illustrative example to demonstrate the proposed models. Experimental data are collected for a vehicle's sliding door mechanism. Results show that the proposed models are effective and the simulation results match the general trend of experimental data based on RMS errors.

scholarly journals Dynamics of Multibody Systems With Spherical Clearance Joints

2005 ◽  
Author(s):  
P. Flores ◽  
J. Ambro´sio ◽  
J. C. P. Claro ◽  
H. M. Lankarani
Keyword(s):  
Contact Force ◽  
Multibody Systems ◽  
Contact Forces ◽  
Force Model ◽  
Clearance Joints ◽  
Continuous Contact ◽  
Clearance Joint ◽  
Contact Force Model ◽  
Dynamics Of Multibody Systems ◽  
The Impact

This work deals with a methodology to assess the influence of the spherical clearance joints in spatial multibody systems. The methodology is based on the Cartesian coordinates, being the dynamics of the joint elements modeled as impacting bodies and controlled by contact forces. The impacts and contacts are described by a continuous contact force model that accounts for geometric and mechanical characteristics of the contacting surfaces. The contact force is evaluated as function of the elastic pseudo-penetration between the impacting bodies, coupled with a nonlinear viscous-elastic factor representing the energy dissipation during the impact process. A spatial four bar mechanism is used as an illustrative example and some numerical results are presented, being the efficiency of the developed methodology discussed in the process of their presentation. The results obtained show that the inclusion of clearance joints in the modelization of spatial multibody systems significantly influences the prediction of components’ position and drastically increases the peaks in acceleration and reaction moments at the joints. Moreover, the system’s response clearly tends to be nonperiodic when a clearance joint is included in the simulation.

A continuous contact force model for impact analysis

2022 ◽  
Vol 168 ◽  
pp. 108739
Author(s):  
Jie Zhang ◽  
Xu Liang ◽  
Zhonghai Zhang ◽  
Guanhua Feng ◽  
Quanliang Zhao ◽  
...  
Keyword(s):  
Contact Force ◽  
Impact Analysis ◽  
Force Model ◽  
Continuous Contact ◽  
Contact Force Model

Dynamic Analysis and Wear Prediction of Planar Five-Bar Mechanism Considering Multiflexible Links and Multiclearance Joints

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Gengxiang Wang ◽  
Hongzhao Liu
Keyword(s):  
Contact Force ◽  
Dynamic Performance ◽  
Contact Forces ◽  
Force Model ◽  
Displacement Curve ◽  
Wear Depth ◽  
Wear Model ◽  
Clearance Joint ◽  
Contact Force Model ◽  
Cylindrical Joint

Effects of wear and member flexibility on the dynamic performance of a planar five-bar mechanism with joint-clearance are investigated. The equation of motion of the mechanism is derived based on the absolute nodal coordinate formulation (ANCF). In order to enhance the accuracy of the contact force, the slope of the load–displacement curve of the cylindrical joint with clearance is used. The contact deformation couples the joint wear to the contact state. The contact force model of Flores and coworkers is improved, by the introduction of the stiffness coefficient. The wear depth is predicted by using the Archard's wear model. Simulations show that the multiclearance joints can generate stronger contact forces relative to single clearance joint case. This leads to more severe wear in the joint. However, the mechanism with multiple flexible links can absorb more of the energy arising from the clearance joint, and this improves the wear phenomenon.

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.

A Method for Real-Time Estimating Pose of Large Aircraft Component in Process of Pose Adjustment Based on the Unscented Kalman Filter

2012 ◽  
Vol 442 ◽  
pp. 251-255
Author(s):  
Zheng Ying
Keyword(s):  
Kalman Filter ◽  
Real Time ◽  
Unscented Kalman Filter ◽  
Kinematic Model ◽  
Estimation Method ◽  
Time Estimation ◽  
Measuring Point ◽  
Aircraft Component ◽  
Forward Kinematic ◽  
Large Aircraft

To estimate the pose of large aircraft component in pose adjustment quickly and accurately, a real-time estimation method based on Unscented Kalman filter (UKF) is proposed. Firstly, in the process of the aircraft component adjustment, a rough value of aircraft component’s pose is acquired by using forward kinematic model and the displacement of positioners on real time. Then, position of a measuring point fixed on aircraft component is obtained by a laser tracker. At last, UKF is employed to integrate the previous rough value and the measuring point position for evaluating the accurate pose of aircraft component. Numerical simulation results show that the presented method is achieved easily, calculated fast and high accurate.

Dynamic Behavior of a Revolute Clearance Joint in Multibody Mechanical Systems

2003 ◽  
Author(s):  
P. Flores ◽  
H. M. Lankarani ◽  
J. Ambro´sio ◽  
J. C. P. Claro
Keyword(s):  
Mechanical Systems ◽  
Force Model ◽  
Continuous Contact ◽  
Revolute Clearance Joint ◽  
Regular Motion ◽  
Clearance Joint ◽  
Contact Force Model ◽  
The Coefficient Of Friction ◽  
The Impact ◽  
Crank Mechanism

This work describes the influence of the clearance size and the coefficient of friction on the dynamic response of a revolute clearance joint in multibody mechanical systems. When there is a clearance in a revolute joint, impacts between the journal and the bearing can occur, and consequently, local deformations take place. The impact is internal and the response of the system is performed using a continuous contact force model. The friction effect due to the contact between joint elements is also modeled. The clearance size and friction effects are analyzed separately. Through the use of Poincare´ maps both periodic and chaotic responses of the system are observed. The results predict the existence of the periodic or regular motion at certain clearance sizes and friction coefficients and chaotic or nonlinear in other cases. A detailed discussion of the results relative to a planar slider-crank mechanism with a revolute clearance joint is presented.

scholarly journals A continuous contact force model of planar revolute joint based on fitting method

2017 ◽  
Vol 9 (2) ◽  
pp. 168781401769047
Author(s):  
Yuntao Li ◽  
Qiquan Quan ◽  
Dewei Tang ◽  
Zhonghong Li ◽  
Zongquan Deng
Keyword(s):  
Contact Force ◽  
Contact Stiffness ◽  
Elastic Force ◽  
Contact Model ◽  
Force Model ◽  
Damping Force ◽  
Revolute Joint ◽  
Continuous Contact ◽  
Contact Force Model ◽  
Fitting Method

Both the process of eliminating the clearance in joints and the contact–impact process involve movement of a clearance mechanism, which may reduce transmission accuracy and lengthen the response time. An appropriate continuous contact force model is able to describe the contact phenomena of a joint with clearance in a facile manner. However, two main problems still should be solved in building the continuous contact force model. First, the elastic force parts in previous continuous contact force models for a revolute joint were established by amending the force exponent of the Hertz spherical contact model or by the modified Winkler contact model. Nevertheless, the force exponent is usually given by experience, and the thickness of the elastic layer in the Winkler theory is difficult to determine. Second, for the previous damping force parts of a revolute joint, the hysteretic damping coefficients were obtained by substituting the stiffness coefficient with the contact stiffness of revolute joint directly instead of using the energy conservation method for the complicated form of elastic force model. A feasible continuous contact force model based on a fitting method was proposed to avoid these problems. According to the experimental results, the continuous contact force model can be used to predict the contact characteristics of a planar revolute joint in a facile manner.

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