Vibration reduction of Cable-Driven Parallel Robots through elasto-dynamic model-based control

Abstract

This paper deals with the elasto-dynamic model-based control of Cable-Driven Parallel Robots (CDPRs), which manifests in the coupling of a PID feedback controller with a model-based feed-forward control scheme. The feed-forward controller is derived from an inverse elasto-dynamic model of CDPR, which compensates the end-effector dynamics and specifically its vibrations due to cable elasticity. The integration of cable tension calculation into this control strategy guarantees positive cable tensions along the trajectory. Simulations and experimentations while using a suspended and non-redundant CDPR show that tracking errors and vibrations can be reduced by the proposed strategy compared to conventional rigid-body model-based control.

Dynamic Modeling and Residual Vibration Suppression of the Redundantly-Actuated Cable Driving Parallel Manipulator

“…Substitute (9) into (8), and divide by r and multiply S J T for both sides of the new equation, which is added up with 7, then the dynamic model of the CDPR can be given as,…”

“…To obtain an accurate dynamic model, the transversal and axial deformation of cables are considered in [7], and the system dynamic model was obtained by eliminating redundant coordinates. While in most of other existing literature, the axial deformation was considered as the dominant component and the transversal deformation was neglected, then cables were modeled as massless axial spring and Newton-Euler equation was applied to establish the dynamic model of the moving platform, hence the system can be obtained from the force equilibrium, which is widely used in most literature for the accuracy and computation efficiency [4], [8], [9]. However, the flexible displacement of the CDPRs in this method was expressed as the difference of the desired and actual length of cables, an explicit expression of the flexible displacement of the moving platform was not given, which is an important variable in vibration suppression.…”

Motion control of a cable-suspended robot using image recognition with coordinate transformation

“…11 Such modified input shaping uses the s curve command ( S -type) to offer superior performance than conventional trapezoidal command ( T -type) in point-to-point positioning control. Furthermore, the vibration analysis of CDPRs based on dynamic stiffness matrix method is proposed in study by Yuan et al 12 In addition, the article deals with the elasto-dynamic model-based control of CDPRs, which manifests in the coupling of a PID feedback controller with a model-based feed-forward control scheme as demonstrated in study by Baklouti et al 13…”

“…Thus, numerous investigations have been dedicated to the elasticity of cables and damping the oscillation due to suspended motion. [10][11][12][13] The input shaping algorithm is implemented for point-to-point control purposes. 11 Such modified input shaping uses the s curve command (S-type) to offer superior performance than conventional trapezoidal command (T-type) in point-to-point positioning control.…”

“…11 Such modified input shaping uses the s curve command (S-type) to offer superior performance than conventional trapezoidal command (T-type) in point-to-point positioning control. Furthermore, the vibration analysis of CDPRs based on dynamic stiffness matrix method is proposed in study by Yuan et al 12 In addition, the article deals with the elasto-dynamic model-based control of CDPRs, which manifests in the coupling of a PID feedback controller with a model-based feed-forward control scheme as demonstrated in study by Baklouti et al 13 Currently, various styles of crane constructions are extensively applied in material handling for various manufacturing purposes. [14][15][16][17] Nevertheless, several kinds of payloads have to be loaded and unloaded, Department of Mechanical Engineering, Chien Hsin University of Science and Technology, Taoyuan City such as satellites, aircrafts, and other eccentric payloads.…”