Comparison of the Efficiency of the Linear Cost function Versus the Two-squared Cost Function in the Analytical Solution of Actuator Redundancy in a Cable
In most research on parallel cable robots, control input energy norm (with two-squared cost function), also known as the least-squares method is widely used, but in addition to the advantages of this method, such as smoothness and differentiable, in the case of the current cable robot, where the cable structure has a physical meaning only in the positive range, using the linear cost function is sufficient in terms of mathematical modeling. With this replacement, without compromising the convexity, the optimization problem on the robot is solved with the low tensile limit and the high rupture limit, and the equal constraint tensile strength of the cables and the moving platform. The simulation results show that while the mentioned the alternative in the cost function does not have a significant effect on solving the optimization problem with numerical methods, the reduction in the average elapsed time to achieve the optimal solution is about 3 times, compared to the analytical method with the two-squared cost function, and is obtained at least 80 times that of numerical methods.