Constructing a platform of robust position estimation for mobile robot by ODR

Today there is an increasing need for robots which move autonomously and work various operations. The robot taken up in this paper is two wheeled vehicle which has 6-D.O.F manipulator. Considering the position estimation of the vehicle, the conventional method is Dead-Reckoning method, which accuracy of estimation is almost good. But once slip occurs to the vehicle, a position estimated from dead-reckoning loses accuracy, because of wheelspin. Slip environment is often seen in our living space. So a wheeled robot has to detect a slip and compensate for the error. Counting the issue described above, mobile robot should have some sensors which obtains its position and attitude in noncontact from the floor. So in this paper, the method using optical sensor to estimate the vehicle position is proposed. This method is called Optical Dead-Reckoning (ODR) method. Two optical sensors mounted under the vehicle body is going to scan the floor and detect vehicle movement. The value obtained from ODR has no error of slip and friction of floor. Based on this ODR method, optical sensors are mounted on the actual robot, and some experimental results are shown.