Latest Papers

ASME Journal of Mechanisms and Robotics

  • Measurement Configuration Optimization and Kinematic Calibration of a Parallel Robot
    by Huang C, Xie F, Liu X, et al. on December 10, 2021 at 12:00 am

    AbstractThis paper presents the kinematic calibration of a four-degrees-of-freedom (4DOF) high-speed parallel robot. In order to improve the calibration effect by decreasing the influence of the unobservable disturbance variables introduced by error measurement, a measurement configuration optimization method is proposed. Configurations are iteratively selected inside the workspace by a searching algorithm, then the selection results are evaluated through an index associated with the condition number of the identification Jacobian matrix; finally, the number of optimized configurations is determined. Since the selection algorithm has been shown to be sensitive to local minima, a meta-heuristic method has been applied to decrease this sensibility. To verify the effectiveness of the algorithm and kinematic calibration, computation validations, pose error estimations, and experiments are performed. The results show that the identification accuracy and calibration effect can be significantly improved by using the optimized configurations.

Mechanical Design of a Low-Impedance 6-Degree-of-Freedom Displacement Sensor for Intuitive Physical Human–Robot Interaction

Abstract

This paper presents the mechanical design of a six-degree-of-freedom low-impedance displacement sensor. The sensor is mounted around a link of a serial robot and used as an interface for physical human–robot interaction. The motivation for the use of a low-impedance sensor is first discussed. The mechanical design of each of the elastic components of the sensor is then presented. The kinematic architecture of the mechanism is introduced, and the inverse and forward kinematic problems are solved. The kinematic sensitivity is then used to characterize the accuracy of the mechanism. Finally, the design of a prototype is presented and experimental results are provided.
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