Abstract:This paper presents a finite element method (FEM) for the kinematic solution of parallel manipulators (PMs), and this approach is applied to analyze the kinematics of a parallel hip joint manipulator (PHJM). The analysis and simulation results indicate that FEM can get accurate results of the kinematics of the PHJM, and the solution process shows that using FEM can solve nonlinear and linear kinematic problems in the same mathematical framework, which provides a theory base for establishing integrated model am… Show more
“…Therefore, it is important to study the thermomechanical coupled analysis of marine gears under large loading and high speed of transmission system. 9,10 Some studies 11,12 are proved that coupled field finite element analysis processes have to be formulated based on the interaction and mutual coupling of two or more physical fields, such as thermo-structural, thermo-electrification, and thermo-magnetic couplings. It is important when the engineering structure is heated or cooled, and then, expansion or contraction may occur.…”
Marine power rear transmission system is a constant power system under specific working condition, which relies on alternating meshing gears to transfer the movement and torque. It is difficult to accurately determine the actual thermal stress and thermal deformation for time-varying distribution using the traditional methods. Elastic structural mechanics modeling and method details of thermal expansion deformation are presented and analyzed. Both the actual reflection thermoelastic contact condition for meshing gears and the coupling effect results of the practical loading process of marine power rear transmission system carried out on alternating meshing gear surfaces are also detailed. In this article, the changes in gear meshing angles of several key meshing positions are presented. The 16 meshing positions of contact stresses and loaded deformation approach are analytically evaluated in terms of the rotation range of driving spur gear (35°) and driving helical gear (36°). The purpose of this study is to confirm the significant stress concentration areas of gear meshing in and meshing out and to obtain that the deformation amounts of gear meshing impact positions within selected zones. The aim of this article is to reach gear deformation on the basis of theoretical conception.
“…Therefore, it is important to study the thermomechanical coupled analysis of marine gears under large loading and high speed of transmission system. 9,10 Some studies 11,12 are proved that coupled field finite element analysis processes have to be formulated based on the interaction and mutual coupling of two or more physical fields, such as thermo-structural, thermo-electrification, and thermo-magnetic couplings. It is important when the engineering structure is heated or cooled, and then, expansion or contraction may occur.…”
Marine power rear transmission system is a constant power system under specific working condition, which relies on alternating meshing gears to transfer the movement and torque. It is difficult to accurately determine the actual thermal stress and thermal deformation for time-varying distribution using the traditional methods. Elastic structural mechanics modeling and method details of thermal expansion deformation are presented and analyzed. Both the actual reflection thermoelastic contact condition for meshing gears and the coupling effect results of the practical loading process of marine power rear transmission system carried out on alternating meshing gear surfaces are also detailed. In this article, the changes in gear meshing angles of several key meshing positions are presented. The 16 meshing positions of contact stresses and loaded deformation approach are analytically evaluated in terms of the rotation range of driving spur gear (35°) and driving helical gear (36°). The purpose of this study is to confirm the significant stress concentration areas of gear meshing in and meshing out and to obtain that the deformation amounts of gear meshing impact positions within selected zones. The aim of this article is to reach gear deformation on the basis of theoretical conception.
“…Finite Element Method (FEM) [ 29 , 30 , 31 ] and Assumed Modes Method (AMM) [ 32 , 33 , 34 ] approaches are the most used ones when modelling flexible links robots for control purposes. As the requirements and procedures of both approaches are different, several studies have been carried out to compare them [ 28 , 35 , 36 ].…”
Section: Theoretical Development Of the Kinematic Virtual Sensormentioning
The control of flexible link parallel manipulators is still an open area of research, endpoint trajectory tracking being one of the main challenges in this type of robot. The flexibility and deformations of the limbs make the estimation of the Tool Centre Point (TCP) position a challenging one. Authors have proposed different approaches to estimate this deformation and deduce the location of the TCP. However, most of these approaches require expensive measurement systems or the use of high computational cost integration methods. This work presents a novel approach based on a virtual sensor which can not only precisely estimate the deformation of the flexible links in control applications (less than 2% error), but also its derivatives (less than 6% error in velocity and 13% error in acceleration) according to simulation results. The validity of the proposed Virtual Sensor is tested in a Delta Robot, where the position of the TCP is estimated based on the Virtual Sensor measurements with less than a 0.03% of error in comparison with the flexible approach developed in ADAMS Multibody Software.
“…Detailed introduction of the PHJM can be obtained from Cheng et al. 25 and Wang et al. 26 Figure 1.Schematic diagram of PHJM.…”
Section: Kinematic and Stiffness Analysismentioning
confidence: 99%
“…According to the kinematics model, the stiffness model of the PHJM can be established. 25,26 Based on the stiffness model of the PHJM, a novel method for judging singularities is presented, then the bifurcation and stability can be analyzed, so the kinematics, stiffness, bifurcation and stability can be analyzed under the same theory framework.…”
Section: Introductionmentioning
confidence: 99%
“…The PHJM is assembled by three SPS-type driving legs L i , a constrained leg l o , a moving platform m, and a fixed base B. P denotes a prismatic joint. S denotes a sphere joint, as shown in Figure 1 Detailed introduction of the PHJM can be obtained from Cheng et al 25 and Wang et al 26 In order to establish the unified model, the mechanism of the PHJM is divided into three flexible legs, one geometrical constraint and one rigid moving platform. Then the rigid-flexible unified model of the PHJM can be obtained.…”
Section: Kinematic and Stiffness Analysis Introduction And Analysis Omentioning
For a parallel hip joint manipulator, the unified kinematics and stiffness model are established based on a novel unified theory, and then the bifurcation and stability are analyzed under the same unified theory framework. In bifurcation analysis, a chaos method is first applied to solve the non-linear bifurcation equations in order to get the full configuration of the parallel hip joint manipulator, which improves the convergence rate and accuracy. Based on the full-configuration solution, the single-parameter and double-parameter simulation for the bifurcation and stability of the parallel hip joint manipulator is performed. The bifurcation simulation results show that the configuration only changes along the corresponding path but cannot change to other paths when the configuration of the parallel hip joint manipulator is at a certain path. The stability simulation results show that when the parallel hip joint manipulator enters into an uncontrolled domain of a bifurcation posture along different paths, the posture component which changes dramatically will lose control first, and the other posture components will move along the changed configuration. In this paper, the kinematics, stiffness, bifurcation and stability of the parallel hip joint manipulator are solved under the same theory framework, which improves the solving efficiency and enriches the mechanical theory for the parallel manipulators.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
