Analytical design of optimal trajectory with dynamic load-carrying capacity for cable-suspended manipulator

Abstract

This paper describes the development of an approach for trajectory planning of cable-suspended parallel robots using optimal control approach. A prototype has been built, and tests have been carried out to verify the theoretical results. This paper briefly illustrates this device and presents some initial tests. The final dynamic equations are organized in a closed form similar to serial manipulator equations. Dynamic load-carrying capacity problem is converted into a trajectory optimization problem which is fundamentally a constrained nonlinear optimization problem. The problem is formulated using optimal control theory, and the ideas are analyzed using Pontryagin's minimum principle. The optimal solutions are found by solving the corresponding nonlinear two-point boundary value problems. The main objective is to find the manipulator load-carrying capacity in point-to-point task by considering actuator torque while cable forces are positive.

Online time-optimal trajectory planning in dynamic workspace of cable suspended robots

“…Although this technique simplifies the analysis significantly, however, it demands rigorous computations to solve the optimization problem induced and relies on predefining the path; the issues that makes it unusable for online trajectory planning. Korayem et al in [14], convert dynamic load-carrying capacity (DLCC) problem into a trajectory optimization problem by use of Pontryagins minimum principle in the control loop of the robot. In their method, poor initial guesses for the costates values may cause divergence of the solution.…”

Multiobjective Trajectory Optimization and Adaptive Backstepping Control for Rubber Unstacking Robot Based on RFWNN Method

“…In order to avoid interference, the AB, CE, and GE segments are set as linear trajectories. In some former researches [1][2][3][4][5][6][7], the trajectory is usually optimized according to a number of fixed teaching points and the way of inserting fixed via points. The optimization method overreliance on the selection of the initial trajectory is mainly to optimize the segmentation trajectory between the fixed via points.…”

“…Chettibi et al discussed the problem of minimum cost trajectory planning for robotic manipulators, which put a few free via points uniformly distributed in time [5]. Korayem et al converted dynamic load-carrying capacity problem into a trajectory optimization problem of cable-suspended parallel robots which is fundamentally a constrained nonlinear optimization 2 Mathematical Problems in Engineering problem [6]. Abu-Dakka et al addressed an indirect method for trajectory planning for industrial robots operating in workspaces with obstacles using an evolutionary algorithm [7].…”

Unfalsified adaptive control for manipulators with parameter uncertainties

“…But, the identification or measurement of parameters is a demanding task, with difficulties on excitation functions, validation of results [5], [6], [7], [8] and possible unexpected performance of the plant [5]. Due to the increasing complexity of robot arm applications like lifting or lowering objects, picking up objects from shelves or helping people with personal care activities, careful evaluation of control performance in novel approaches becomes an issue of interest, considering the analysis of the ability to handle payloads in common daily situations due to sudden changes or unstructured environments [9], [10], [11].…”