Geometric Parameter Calibration for a Cable-Driven Parallel Robot Based on a Single One-Dimensional Laser Distance...

Area of Science:

• Robotics
• Mechatronics
• Control Systems

Background:

• Cable-driven parallel robots (CDPRs) offer advantages like large workspaces and high payload capacity.
• Geometric uncertainty and kinematic errors arise in large-workspace CDPRs, hindering precise control.
• Existing calibration methods are often inadequate or costly for CDPRs.

Purpose of the Study:

• To develop an inexpensive auto-calibration methodology for over-constrained CDPRs.
• To introduce a novel calibration sensor device using laser distance sensors.
• To improve the kinematic accuracy and control precision of CDPRs.

Main Methods:

• A five-phase calibration workflow: preparation, modeling, measuring, identification, and adjustment.
• Utilizing one-dimension laser distance sensors attached to the robot end-effector.
• Developing calibration algorithms accounting for CDPR kinematics, cable elongation, and pulley kinematics.

Main Results:

• Kinematic parameters identified with 0.92 mm accuracy.
• Robot position control accuracy improved by 58%.
• Validation on the MINI cable robot and applicability to massive-size CDPR systems confirmed.

Conclusions:

• The proposed sensor device and auto-calibration methodology effectively overcome geometric uncertainty in CDPRs.
• Precise robot control is achievable with the developed system.
• The method is scalable and applicable to both small and large-scale CDPR applications.