Unified model for the output accuracy of open-chain manipulators that considers joint clearance and structural parameters

Qu, Shuwei; Li, Ruiqin; Bai, Shaoping; Liang, Shijie

doi:10.1007/s12206-018-0940-z

Cited by 8 publications

(3 citation statements)

References 16 publications

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“…Sun et al [10] used the Lankarani-Nikravesh contact force model to describe the clearance hinge and analyzed the motion accuracy of the crank-slider system with hinge clearance. Qu et al [11] described the contact force of the hinge with clearance by using the Flores contact force model and the Lucre friction force model, and studied the influence of the position, size, and number of the hinge gap on the dynamic characteristics of the deployable planar X-shaped structure. Chen et al [12] developed a nonlinear dynamics model of a nine-link mechanical system considering the hinge clearance and connecting rod flexibility by using the Lagrangian method and studied the influence of crank clearance value and driving speed on the dynamic characteristics of system.…”

Section: Introductionmentioning

confidence: 99%

Study on Collision Dynamics Model and Multi-Body Contact Forces of Ball Cage Flexible Joint Considering Clearance

et al. 2023

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Flexible joints are widely used in ‘soft’ touching and holding, and they represent the main component of ultra-short radius drilling tools. The analysis of contact and motion characteristics is an essential issue in the design and development stage of flexible joints. In this study, a collision dynamics model of a ball cage flexible joint (BCFJ), which is suitable for the characteristics of small clearance and large load, is established. The model contains a nonlinear stiffness coefficient and can describe the contact force between the ball key and the raceways. Moreover, the computational procedure for the dynamic analysis of BCFJ with clearance is established, and the dynamic simulation for collision and contact between ball, cage, outer race, and inner race was carried out. By numerical calculation, the variation of contact force on the five contact points of the ball key and ball cage is discussed, and the influence of ball cage clearance on contact force between ball key, ball seat, and ball cage is obtained. The results indicate that the effects of the ball cage clearance on the contact force cannot be ignored, which is the main cause for the vibration of the flexible joint system, and the amplitude of the contact force will gradually increase with the increase of the clearance. The proposed model and procedure can analyze the dynamic behavior of flexible joints with small clearance and large load, providing a basis for further research on wear prediction and safety evaluation of the BCFJ with clearance.

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Section: Introductionmentioning

confidence: 99%

Study on Collision Dynamics Model and Multi-Body Contact Forces of Ball Cage Flexible Joint Considering Clearance

et al. 2023

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“…Considering the joint clearance and structural parameters, Qu et al. 19 built a unified model for the output accuracy of the open-chain manipulators. Taking the Pa-Quad parallel mechanism as an example, Sun et al.…”

Section: Introductionmentioning

confidence: 99%

“…Then he studied the pose error for parallel mechanism with actuation redundancy. Considering the joint clearance and structural parameters, Qu et al 19 built a unified model for the output accuracy of the open-chain manipulators. Taking the Pa-Quad parallel mechanism as an example, Sun et al 20 proposed the accuracy improvement strategy by geometric accuracy design and error compensation.…”

Section: Introductionmentioning

confidence: 99%

Accuracy analysis and synthesis of asymmetric parallel mechanism based on Sobol-QMC

Yue

Chen

et al. 2020

Proceedings of the Institution of Mechanical Engineers, Part C:

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Aiming at the aircraft composite skin grinding, a new three degree-of-freedom (DOF) parallel mechanism with asymmetrical structure (TAM) is proposed to replace manual grinding. The TAM is achieved by integrating one of active limbs into the passive limb while keeping the required DOF unchanged, which is divided into two closed-loop chains: telescopic rod and parallelogram. The inverse kinematics models of the two chains are established according to closed-loop vector method. Thus, the actuation and the constraint Jacobian matrix are obtained. Based on the perturbation principle, the error modeling of the TAM is built. Adopting the constraint Jacobian matrix, 15 uncompensated errors are distinguished from the error model. In order to improve the working accuracy of the TAM, accuracy analysis and synthesis are necessary for all the uncompensated errors. The mapping function reflects the influence of uncompensated errors on the pose accuracy. The global sensitivity evaluation indexes are established by mapping function. Since Sobol sequences are superior in uniformity and convergence, the Quasi-Monte Carlo method based on Sobol sequences (Sobol-QMC) is introduced for sensitivity analysis. Taking the minimum manufacturing and installation costs as the optimization target, the objective function of accuracy synthesis is constructed. Ultimately, the reasonable tolerance zone of each uncompensated error is calculated by genetic algorithm. Simulation is performed by Sobol-QMC to verify the rationality of the optimization. The results show the probability is above 97% where most pose errors are in [[Formula: see text], [Formula: see text]] within the workspace. Therefore, accuracy synthesis is correct and practical.

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Accuracy analysis of spatial multi-loop mechanism effected by paired bearings support joint clearance

Lin

Chen

et al. 2020

J Mech Sci Technol

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Unified model for the output accuracy of open-chain manipulators that considers joint clearance and structural parameters

Cited by 8 publications

References 16 publications

Study on Collision Dynamics Model and Multi-Body Contact Forces of Ball Cage Flexible Joint Considering Clearance

Study on Collision Dynamics Model and Multi-Body Contact Forces of Ball Cage Flexible Joint Considering Clearance

Accuracy analysis and synthesis of asymmetric parallel mechanism based on Sobol-QMC

Accuracy analysis of spatial multi-loop mechanism effected by paired bearings support joint clearance

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