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.

Increasing Mobile Robot Efficiency and Versatility Through Manipulation-Driven Adaptation 1


Terrestrial mobile robotics are crucial to a range of missions including planetary exploration, search and rescue, logistics, and national security. Many of these missions require the robot to operate on a broad variety of terrain. Wheels are ideal for energy efficiency but can suffer catastrophic failure when presented with obstacles or complex ground. Legs can help traverse obstacles but at the cost of energy efficiency. Physical adaptation can enable a robot to benefit from both modes of locomotion. This article describes a new approach to physical adaptation through manipulation. Specifically, this article examines how manipulators can be used to change the vehicle’s mode of locomotion and improve energy efficiency and versatility. This article presents “swappable propulsors,” which can be easily attached/detached to adapt the vehicle through the use of permanent magnets. A new robot system that uses its manipulator to discretely switch between wheeled and legged locomotion is created. The experimental results demonstrate how this approach provides a unique combination of energy efficiency and versatility. This study describes the design of swappable propulsors, analyzes how to manipulate them, and describes how they can be used to improve performance. This study extends on prior work with additional analysis, an improved robot prototype, and new experimental results.
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