Kinematic Modelling and Motion Mapping of Robotic Arms

Abstract

Robotic systems are known for their precision and accuracy. To achieve a desired set of operating parameters the system must have a good control system. Robotic arms can vary in size shape and purpose of use. With increasing DOF (Degree of Freedom) the complexity of the system increases and hence a DAQ system is required to check various parameters of the process. This paper discusses the implementation of kinematic and inverse kinematic modelling of a 6 Degree of Freedom (DOF) hydraulic arm in MATLAB environment. The forward kinematic model is based on Denavit-Hartenberg parameters. To obtain a given set of position and orientation of end effector, inverse kinematics gives the required set of joint angles. Potentiometers mounted on arm joint are used as the prime feedback elements for extracting the joint angles. All six joints of the arm are revolute joints. The values of potentiometer obtained are compared to the desired input values. Proportional direction control valve is the main controlling element of the hydraulic circuit. The forward and inverse kinematics is validated and implemented in MATLAB robotics toolbox (developed by Peter Croke). A GUI is also used to ease the process of retrieving and feeding the information in the system. The results of forward and inverse kinematics from MATLAB are verified by the physical model discussed in this paper.