Teleoperated Service Robot with an Immersive Mixed Reality Interface

Teleoperated service robots can perform more complex and precise tasks as they combine robot skills and human expertise. Communication between the operator and the robot is essential for remote operation and strongly affects system efficiency. Immersive interfaces are being used to enhance teleoperation experience. However, latency or time delay can impair the performance of the robot operation. Since remote visualization involves transmitting a large amount of video data, the challenge is to decrease communication instability. Then, an efficient teleoperation system must have a suitable operation interface capable of visualizing the remote environment, controlling the robot, and having a fast response time. This work presents the development of a service robot teleoperation system with an immersive mixed reality operation interface where the operator can visualize the real remote environment or a virtual 3D environment representing it. The virtual environment aims to reduce the latency on communication by reducing the amount of information sent over the network and improve user experience. The robot can perform navigation and simple tasks autonomously or change to the teleoperated mode for more complex tasks. The system was developed using ROS, UNITY 3D, and sockets to be exported with ease to different platforms. The experiments suggest that having an immersive operation interface provides improved usability for the operator. The latency appears to improve when using the virtual environment. The user experience seems to benefit from the use of mixed reality techniques; this may lead to the broader use of teleoperated service robot systems

A Measure of Shape Dissimilarity for 3D Curves

We present a quantitative approach to the measurement of shape dissimilarity between two 3D (three-dimensional) curves. Any 3D continuous curve can be digitalized and represented as a 3D discrete curve. Thus, a 3D discrete curve is composed of constant orthogonal straightline segments. In order to represent 3D discrete curves, we use the orthogonal direction change chain code. The chain elements represent the orthogonal direction changes of the contiguous straight-line segments of the discrete curve. This chain code only considers relative direction changes, which allows us to have a curve descriptor invariant under translation and rotation. Also, this curve descriptor may be starting point normalized and mirroring curves may be obtained with ease. Thus, using the above-mentioned chain code it is possible to have a unique 3D-curve descriptor. To find out how close in shape two 3D curves are, a measure of shapeof-curve dissimilarity between them is introduced; analogous curves will have a low measure of shape dissimilarity, while different curves will have a high measure of shape dissimilarity. When this measure of shape dissimilarity is normalized, its values vary continuously from 0 to 1. If 1 Author to whom correspondence should be addressed 728 E. Bribiesca and W. Aguilar two curves are identical, the value of the measure of shape dissimilarity is equal to 0. The computation of this measure for two curves is based on the analysis of their common and different subcurves represented by their chain elements. Finally, we present some results of the computation of the proposed measure for 15 curves. Mathematics Subject Classification: 65D17 Keywords: Shape-of-curve dissimilarity, 3D discrete curves, chain coding, measure of shape dissimilarity, 3D curve representation