Wire-based tracking using mutual information

Abstract

Wire-based tracking devices are an affordable alternative to costly tracking devices. They consist of a fixed base and a platform, attached to the moving object, connected by six wires whose tension is maintained along the tracked trajectory. One important shortcoming of this kind of devices is that they are forced to operate in reduced workspaces so as to avoid singular configurations. Singularities can be eliminated by adding more wires but this causes more wire interferences, and a higher force exerted on the moving object by the measuring device itself. This paper shows how, by introducing a rotating base, the number of wires can be reduced to three, and singularities can be avoided by using an active sensing strategy. This also permits reducing wire interference problems and the pulling force exerted by the device. The proposed sensing strategy minimizes the uncertainty in the location of the platform. Candidate motions of the rotating base are compared selected automatically based on mutual information scores.

Design of a String Encoder‐and‐IMU‐Based 6D Pose Measurement System for a Teaching Tool and Its Application in Teleoperation of a Robot Manipulator

“…According to the results of [26], the average position and orientation errors of the system are about 5 mm and 6°, respectively. In [27], it can be seen that the position and orientation errors of the system are about 200 mm and 9°, respectively, in compound motion. In [28], the cable-driven parallel robot system has 9.4 mm position and 1.2°orientation errors, respectively.…”

“…Journal of Sensors and relatively high accuracy. In addition, placement selection of string encoder bodies and their wire ends together with used calculation techniques, which are explained in the following sections, makes this study have better results in comparison to similar studies [14,23,[26][27][28]. Moreover, yaw angle calculation by using two additional string encoders eliminates the need for the yaw angle output of IMU which has random walk and drift problems due to its nature.…”