• MACHINES

    FUZZY – ROBUST CONTROL OF A TWO-LINK ROBOT ARM

    Machines. Technologies. Materials., Vol. 11 (2017), Issue 5, pg(s) 214-217

    Parameters of the robots are always changed due to the load being carried. Robust control is a method that considers the changes of control system performance related to the modification of system parameters. Stability and performance of the system can be well protected in case the change of system parameters does not affect the system. Even if there is several modified parameters, robust control system still provides the ability of control in a desired manner.

    In this work, parameters are made changeable and the upper limit of the uncertainty parameter is kept constant unlike other robust control studies. Control parameter is updated over time depending on the trigonometric functions. The values of the constant control parameters in trigonometric functions affect the performance of the system and it is quite difficult to find appropriate control parameter values. Logical fuzzy compensator is designed to find this parameter and investigated the effects on the tracking error of two-link robot.

    Fuzzy Logic associated robust control methods developed using robust control has been compared through a computer simulation using the same trajectory and same model. Thanks to the designed fuzzy logic associated robust controller, robust control is improved and two-link robot’s trajectory tracking error has been reduced to a very small value.

  • DOMINANT TECHNOLOGIES IN “INDUSTRY 4.0”

    BALANCE CONTROL OF SEGWAY ROBOTS USING ADAPTIVE-ROBUST CONTROLLER

    Industry 4.0, Vol. 2 (2017), Issue 1, pg(s) 38-41

    Due to its compatibility and functionality, segways have been widely used in many countries. It was first introduced in December 2001.Yet, segway robots are faced with problems such as friction and external disturbances. Therefore, some controllers are designed to overcome with these problems. In previous studies, traditional controllers are used to balance a two-wheeled segway robot. The aim of this study is to minimize the trajectory tracking error. Due to external disturbances, such as wind, force and torque, robot parameters cannot be calculated exactly. Hence, the parameters of the robot are assumed to be unknown. In such situations, adaptive and robust controllers give better results. Adaptive and robust control laws were examined and adaptive-robust system was designed for the segway robot. Then Lyapunov function was defined and this adaptive-robust controller was derived from the Lyapunov function. And this control system applied to a two-wheeled segway robot model.