/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en
NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://dx.doi.org/10.1108/01439910510593938Industrial Robot Journal, 32, 3, pp. 240-247, 2005-05-01 Landmine detection using an autonomous terrain-scanning robot Najjaran, H.; Goldenberg, A.
AbstractThis paper describes the software of a terrain scanning robot capable of autonomously manipulating a typical handheld detector for remote sensing of buried landmines in a manner similar to a human operator. The autonomous manipulation of the detector on unknown terrain requires an online terrain map to generate an obstacle free path for the end effector of the robot. The software includes a twofold process of map building and path planning that is implemented into a real-time software platform to take place in parallel to the other functions of the robot.Map building features a distributed sensor fusion system to tackle the uncertainties associated with the sensor data. It provides local terrain maps by fusing the redundant measurements and complementary data obtained from competitive rangefinders and joint position sensors, respectively.The fusion takes place in a multi-step data processing module that includes a batch processing filter, a static filter, and a fuzzy adaptive Kalman filter. The latter requires the dynamic model of the process so that a stochastic model is introduced for the terrain undulations. An important parameter of the model, which significantly influences the output of the filter, is the standard deviation of the probability distribution of the process disturbances. A systematic fuzzy modeling technique is used to determine the standard deviation based on the terrain type and to adapt the filter, accordingly. The outlier rejection is carried out using the Mahalanobis distance between the estimated states of the system and the new measurements.Path planning is carried out based on the terrain map to move the detector at a constant distance and parallel to the ground. Unlike the traditional methods, the path is generated in the non-Cartesian coordinate frame of the sensors to avoid a great deal of transformations involved in reproducing the terrain map in a Cartesian coordinate frame.