Development of Omni-Wheeled Mobile Robot Based-on Inverse Kinematics and Odometry

Abstract

This paper presents the development of an omni-wheeled mobile robot based on inverse kinematics and odometry for local and indoor navigation purposes, such as for automatic warehousing in industry or healthcare environment. The robot uses four-wheeled diagonal configuration to conform directional angles of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\pmb{\alpha_{1}=45^{\mathrm{o}}, \alpha_{2}=135^{\mathrm{o}}, \alpha_{3}=225^{\mathrm{o}}}$</tex> , and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\pmb{\alpha_{4}=315^{\mathrm{o}}}$</tex> Inverse kinematics is utilized to drive the robot to a point with specific trajectory and heading angle. Internal wheeled-encoders mounted in each DC-motors are used to read the angular speed and position. This research utilizes odometry technique to estimate the robot's position relative to the initial position. In order to develop a more precise odometry result, we combine the use of wheeled-encoders and an IMU. In order to maintain robot's position relative to the desired position, a PID control is applied to the algorithm. The result of the tests show that the developed omni-wheeled mobile robot is capable of performing locomotion to the desired position and to follow a controlled trajectory by maintaining a minimum error relative to the referenced trajectory.