Design of Reconfigurable Cable-Driven Parallel Robots

Abstract

This chapter is dedicated to the design of Reconfigurable Cable-Driven Parallel Robots (RCDPRs) where the locations of the cable exit points on the base frame can be selected from a finite set of possible values. A task-based design strategy for discrete RCDPRs is formulated. By taking into account the working environment, the designer divides the prescribed workspace or trajectory into parts. Each part shall be covered by one configuration of the RCDPR. Placing the cable exit points on a grid of possible locations, numerous CDPR configurations can be generated. All the possible configurations are analysed with respect to a set of constraints in order to determine the parts of the prescribed workspace or trajectory that can be covered. The considered constraints account for cable interferences, cable collisions, and wrench feasibility. The configurations satisfying the constraints are then compared in order to find the combinations of configurations that accomplish the required task while optimising one or several objective function(s). A case study comprising the design of a RCDPR for sandblasting and painting of a three-dimensional tubular structure is finally presented. Cable exit points are reconfigured, switching from one side of the tubular structure to another, until three external sides of the structure are covered. The optimisation includes the minimisation of the number of cable attachment/detachment operations required to switch from one configuration to another one, minimisation of the size of the RCDPR, and the maximisation of the RCDPR stiffness.

Reconfigurable fully constrained cable-driven parallel mechanism for avoiding collision between cables with human

“…Still, these methods are not applicable for some processes where the trajectory is predefined and should not be changed, such as the assembly process. Reconfiguration of CDPM's components, such as motorized reels, may improve the capability of CDPM and increase the workspace size [25].…”

“…Gagliardini et al [25] focuses on relocation of attachment points on the base of Reconfigurable Cable Driven Parallel Mechanism or RCDPMs. According to the environment, the designer divides the defined workspace in n parts.…”

“…The reconfiguration process in 10 steps is explained in ref. [25]. To pass from one configuration to another, one or more cables must be disconnected from their initial attachment points and connected to new attachment points location.…”

A collaborative path planning method for mobile cable-driven parallel robots in a constrained environment with considering kinematic stability

“…Consequently, there is a need for CDPRs to tune their geometry structure for adapting to the environment and performing tasks. Based on the concept of reconfiguration, reconfigurable cable-driven parallel robots (RCDPRs) were developed, in which the position of pulleys can be altered [6]. However, the most of proposed RCDPRs still have a fixed frame, and their extensibility is limited due to the winch-pulley system cannot be freely moved.…”

Potential Energy Distribution of Redundant Cable-Driven Robot Applied to Compliant Grippers: Method and Computational Analysis

“…Cable-driven parallel robots (CDPR) [1,2,3] are a kind of parallel robot whose links that connect the end-effector with actuators are cables. Because they bend under compression forces, they need to be under tension to impose their kinematic restriction.…”