Dynamic modeling and analysis of spatial parallel mechanism with revolute joints considering radial and axial clearances

2021 ◽  
Author(s):  
Xiulong Chen ◽  
Weitao Yang
Keyword(s):  
Dynamic Modeling ◽  
Parallel Mechanism ◽  
Modeling And Analysis ◽  
Revolute Joints ◽  
Spatial Parallel Mechanism

scholarly journals Kinetoelastodynamics Modeling and Analysis of Spatial Parallel Mechanism

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Xiulong Chen ◽  
Yunfeng Li ◽  
Yu Deng ◽  
Wenbin Li ◽  
Haibin Wu
Keyword(s):  
Geometric Nonlinearity ◽  
Parallel Mechanism ◽  
Natural Frequencies ◽  
Theoretical Base ◽  
Dynamic Behaviors ◽  
Modeling And Analysis ◽  
Velocity Error ◽  
Spatial Parallel Mechanism ◽  
Elastodynamic Modeling ◽  
Simulation Results

The nonlinear elastodynamic modeling and analysis of the 4-UPS-UPU spatial 5-degree-of-freedom parallel mechanism are investigated. The kinetoelastodynamics theory is used to derive the elastic dynamic equations of 4-UPS-UPU spatial parallel mechanism. In order to grasp the effect of geometric nonlinearity on dynamic behaviors, such as displacement error output, velocity error output, acceleration error output, stress of driving limbs, and natural frequencies, the variations of dynamic behaviors considering geometric nonlinearity and without considering geometric nonlinearity are discussed, respectively. The numerical simulation results show the nonlinear elastodynamic model established can reasonably reflect the dynamic behaviors of 4-UPS-UPU spatial parallel mechanism with flexible driving limbs. And geometric nonlinearity is demonstrated to have significant impact on dynamic response and dynamic characteristics of spatial parallel mechanism. The researches can provide important theoretical base for the optimal design of spatial parallel mechanism.

scholarly journals Dynamic modeling of spatial parallel mechanism with multi-spherical joint clearances

2019 ◽  
Vol 16 (5) ◽  
pp. 172988141987591 ◽  
Author(s):  
Xiulong Chen ◽  
Chenghao Sun
Keyword(s):  
Dynamic Model ◽  
Dynamic Modeling ◽  
Parallel Mechanism ◽  
High Speed ◽  
Force Model ◽  
Spherical Joint ◽  
Universal Joint ◽  
Prismatic Joint ◽  
Spatial Parallel Mechanism ◽  
Joint Clearances

The parallel mechanism has advantages of the high speed, high precision, strong carrying capacity, and high structural rigidity. Most of the previous studies concerning the dynamic modeling focused on planar mechanisms with revolute clearance joints or spatial mechanisms with one spherical joint clearance, while few studies focused on spatial parallel mechanisms with multi-spherical joint clearances. In this article, a general dynamic modeling method for spatial parallel mechanism with multi-spherical joint clearances based on Lagrange multiplier method is proposed. Taking 4universal joint-prismatic joint-spherical joint/universal joint-prismatic joint- universal joint (4UPS-UPU) spatial parallel mechanism as an example, the constraint equations of common kinematic pairs in spatial parallel mechanism, such as universal joint, spherical joint, and prismatic joint, are derived in detail. The dynamic model of the parallel mechanism with two spherical joint clearances combining the Flores contact force model and the LuGre friction model is established. The correctness of model has also been verified by comparing the analysis results of MATLAB with those of ADAMS. It can be seen that dynamic model of spatial parallel mechanism with multi-spherical joint clearances could be easily established by this method, which provides a theoretical reference to establish the dynamic model of other parallel mechanism with multi-clearance in the future.

Modular dynamic modeling and analysis of planar closed-loop mechanisms with clearance joints and flexible links

2016 ◽  
Vol 231 (3) ◽  
pp. 522-540 ◽  
Author(s):  
Zhendong Song ◽  
Xiaojun Yang ◽  
Bing Li ◽  
Wenfu Xu ◽  
Hong Hu
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Modeling ◽  
Evaluation System ◽  
Parallel Mechanism ◽  
Closed Loop ◽  
Dynamic Effect ◽  
Contact Forces ◽  
Modeling And Analysis ◽  
Flexible Links ◽  
Clearance Joints

Dynamic analysis of a mechanism with clearance joints and flexible links is a research focus in the field of multibody dynamics. In this study, a general modular dynamic modeling approach based on Lagrange multiplier method for planar closed-loop mechanisms is proposed in order to improve the modeling efficiency and reusability of a structure having same topology. With this approach, dynamic analysis considering clearance joints and flexible links can be performed conveniently. A novel mathematical model to determine the relative motion modes between the two components of a clearance joint is developed based on the previous contact detection method. A complete dynamic effect evaluation system, which measures the influence of clearance joints and flexible links on the dynamic performances more conveniently and intuitively, is established. A planar 3-RRR parallel mechanism that is a closed-loop system including imperfect joints and flexible links is studied as an example. The dynamic model of this mechanism is established and its dynamic characteristics are investigated. The couple effects of clearance joints and flexible links for a parallel mechanism are investigated first. The contact forces existing in the clearance joints can cause system vibration and thus reduces the dynamic stability of the whole mechanical system. Meanwhile, the simulation results indicate that the flexible links can damp the vibration of the moving platform caused by clearance joints is certain.

scholarly journals Dynamic response analysis for multi-degrees-of-freedom parallel mechanisms with various types of three-dimensional clearance joints

2021 ◽  
Vol 18 (3) ◽  
pp. 172988142110177
Author(s):  
Jia Yonghao ◽  
Chen Xiulong
Keyword(s):  
Dynamic Response ◽  
Multibody Systems ◽  
Parallel Mechanism ◽  
Three Dimensional ◽  
Response Analysis ◽  
Parallel Mechanisms ◽  
Dynamics Model ◽  
Clearance Joints ◽  
Clearance Joint ◽  
Spatial Parallel Mechanism

For spatial multibody systems, the dynamic equations of multibody systems with compound clearance joints have a high level of nonlinearity. The coupling between different types of clearance joints may lead to abundant dynamic behavior. At present, the dynamic response analysis of the spatial parallel mechanism considering the three-dimensional (3D) compound clearance joint has not been reported. This work proposes a modeling method to investigate the influence of the 3D compound clearance joint on the dynamics characteristics of the spatial parallel mechanism. For this purpose, 3D kinematic models of spherical clearance joint and revolute joint with radial and axial clearances are derived. Contact force is described as normal contact and tangential friction and later introduced into the nonlinear dynamics model, which is established by the Lagrange multiplier technique and Jacobian of constraint matrix. The influences of compound clearance joint and initial misalignment of bearing axes on the system are analyzed. Furthermore, validation of dynamics model is evaluated by ADAMS and Newton–Euler method. This work provides an essential theoretical basis for studying the influences of 3D clearance joints on dynamic responses and nonlinear behavior of parallel mechanisms.

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