Development of real time programming for the trajectory control and dynamic characterization of robot manipulators

Abstract

Dynamic characterization of single link flexible manipulator based on C++ (open source) environment has been presented. The differential equations representing the dynamics of single link flexible manipulator have been derived based on finite element method. While modeling the manipulator system, both rigid and flexural behaviors of the manipulator have been considered. The differential equations are solved using numerical methods; Forward-Euler (FE) and Fourth order Runge-Kutta method (RK4). The derived second order differential equations are then converted into a set of first order equations and then solved using FE and RK4 methods. The solutions obtained from the numerical methods have been compared for the solution accuracy. The dynamic characteristics of flexible manipulator such as hub angle, hub velocity, residual motion and end point displacement have been obtained using C++ environment. The entire procedure has been implemented in Dev C++ software (open source) through manual coding. Gnuplot (open source) is a plotting tool which is utilized to plot the dynamic solutions executed in C++ environment. Based on finite element procedure, internal damping and payload mass attached at the end of the manipulator have been included in the model in order to analyze their effects on the dynamic characteristics of the manipulator system. In order to validate the solution obtained using the proposed open source approach, state space representation of the dynamic model of the flexible manipulator has been derived to analyze in Matlab environment. The simulation results demonstrate that the proposed C++ based dynamic analysis of complex dynamic system such as flexible manipulator provides researchers and students a better platform compared to Matlab like commercial software which is very expensive. Trajectory tracking control of two-link rigid planar robot manipulator using proportional-integral-derivative (PID) control based on Matlab and C++ environments has also been presented in this work. Two-link planar rigid manipulator is a complex dynamic system, where interaction effects within the links of the manipulator such as coriolis and centrifugal effects make the system dynamics a complex one. Trajectory tracking control of two-link planar rigid manipulator is an important task as it has been used in manufacturing industries for various applications such as painting, welding, pick and place, assembly, etc. The coupled differential equations representing the dynamics of the two-link planar rigid manipulator have been considered for trajectory tracking control task. PID control law has been included in the coupled dynamic equations to demonstrate the controller performance on trajectory tracking task and the differential equations incorporated with the PID control law are solved using FE and RK4 methods to obtain controlled time varied input torque required to track the desired trajectory.Simulink model of two-link planar rigid robot manipulator has been developed and solved inMatlab environment in order to validate the proposed C++ based analysis. Simulation of the proposed work shows good agreement of results between Matlab/simulink and C++ environments newline