An improved meta-heuristic algorithm to optimize the fractional-order controller for an industrial manipulator with a parallelogram structure

Nowadays, robotic systems are widely used in advanced industrial operations. Therefore, making appropriate control decisions to ensure the efficiency of these systems is critical. Criteria such as operation time and response speed, control cost, and system error need to be controlled by providing appropriate methods to ensure the successful performance of industrial operations. Therefore, this article pursues two main objectives1) controlling the robotic system by presenting a method based on fractional-order calculus so that it can control the system despite its complexity and non-linearity, 2) presenting the meta-heuristic algorithm "Improved Grey Wolf" to optimize the system response.

First, the mathematical model of the robot is presented based on Lagrange rules, and then the fractional-order calculus is used to design the controller. In addition, the efficiency of the grey wolf algorithm is increased with the introduction of an improved method.

Different cost functions based on the main performance criteria of the robotic system are introduced, and an improved algorithm is applied to them. The comparison results of the proposed algorithm and other algorithms, indicate its satisfying performance. In addition, the efficiency of the fractional-order controller is compared with its integer-order counterpart, and the results show a significant improvement in system performance.

Originality/Value: 

The proposed controller can control the system well despite its complexity and non-linearity. In addition, inspired by the Grey Wolf algorithm, an improved optimization method is proposed that can increase the efficiency of the controlled system. Numerical results show the satisfying performances of the proposed controller and the improved optimization algorithm.