Design of a Sliding Mode Controller for Two-Wheeled Balancing Robot

Nowadays, the control of mechanical systems with fewer inputs than outputs (Under-actuated systems) has become a challenging problem for control engineers. Two-wheeled balancing robots is one of the appealing examples of this category. This type of robot contains two parallel wheels and an inverted pendulum. In this research, designing of controller have been investigated for flat surfaces. For controller design, the extract dynamics of the system has been achieved based on Kane's method. Then for the two-wheeled balancing robot, one sliding mode controller has been designed for yaw angle, and another sliding mode controller has been designed to control both position and pitch angle based on a proposed sliding surface. The main feature of the proposed controllers is that all of controllers have been designed based on the nonlinear dynamics of system. Also, considering the limits of uncertainties while designing systems, the robustness of controllers have been increased. The common problem of sliding mode control is chattering phenomenon that has been greatly reduced using saturation function instead of sign function. Simulation results comparision of the designed controller with a LQR controller, validates the effectiveness of the proposed controller

Designing, Implementation and Modeling of an Acrobot Mechanism and its Interface with MATLAB

Nowadays, the control of machenical systems with fewer inputs than outputs (Underactuated systems) has become a challenging problem for control engineers. The 2DOF Acrobot system is one of the appealing example of this category. The goal of this paper, is designing, modeling and implementation of an Acrobot system to use in linear control, digital control, robotics and artificial intelligence labs. So, at first, a suitable mechanism (simple and low price) was designed by SolidWorks. Then, the designed mechanism was made carefully. In the next step, dynamical model of the system was obtained based on Euler-Lagrange method. After implementation of some practical subsystem in the Simulink environment, the Acrobot system was linked with the MATLAB using a Data Acquisituon card

Identification and Control of an Implemented Acrobot System

The main goal of this paper is to identify the parameters of an Acrobot system and to design a suitable controller for it. So, the parameters of nonlinear model were identified in four steps using Genetic Algorithm. Then, a new swing-up algorithm was proposed. Also, after linearization of dynamics, an optimal state feedback controller was designed to balance the Acrobot links. Since, the controller was acted well only near unstable equilibrium point, another state feedback controller was designed by Genetic Algorithm for the farther points. Simulation results show the suitable performance of the proposed methods