Control (management)

Parallel manipulator

Engineering

Statistics

Inverse kinematics

Calibration

Computer science

Classical mechanics

Pulley

Physics

Forward kinematics

Mathematics

Artificial intelligence

Geometry

Structural engineering

Point (geometry)

Kinematics

Control theory (sociology)

Mechanism and Machine Theory

Pulleys used in cable-driven parallel robots (CDPRs) introduce a time-varying geometry that adds significant complexity to the CDPR's kinematic model. The proximal point-to-point method brings significant model error and makes it difficult to achieve high accuracy for CDPRs, especially when the CDPR's scale is small. To solve this problem, this paper establishes the kinematics of CDPRs considering pulley mechanisms and further develops the error model as well as the kinematic calibration method for CDPRs. Firstly, the kinematic characteristics of the pulley mechanisms are analyzed, and the complete kinematic model of CDPRs is established. Then, the error modeling method considering pulley kinematics is established, and the error identification matrix is derived. Based on these results, the kinematic calibration method for CDPRs considering the pulley kinematics is established, including the calibration process and measurement pose selection. Finally, the proposed methods are verified via both simulations and experiments by taking the translational TBot CDPR as an example. The terminal accuracy of the TBot-600 CDPR is improved by 30% with the proposed methods considering the kinematics of pulleys.

Kinematic Calibration of Cable-Driven Parallel Robots Considering the Pulley Kinematics