Two-Dimensional Radial Laser Scanning for Circular Marker Detection and External Mobile Robot Tracking

Abstract

This paper presents the use of an external fixed two-dimensional laser scanner to detect cylindrical targets attached to moving devices, such as a mobile robot. This proposal is based on the detection of circular markers in the raw data provided by the laser scanner by applying an algorithm for outlier avoidance and a least-squares circular fitting. Some experiments have been developed to empirically validate the proposal with different cylindrical targets in order to estimate the location and tracking errors achieved, which are generally less than 20 mm in the area covered by the laser sensor. As a result of the validation experiments, several error maps have been obtained in order to give an estimate of the uncertainty of any location computed. This proposal has been validated with a medium-sized mobile robot with an attached cylindrical target (diameter 200 mm). The trajectory of the mobile robot was estimated with an average location error of less than 15 mm, and the real location error in each individual circular fitting was similar to the error estimated with the obtained error maps. The radial area covered in this validation experiment was up to 10 m, a value that depends on the radius of the cylindrical target and the radial density of the distance range points provided by the laser scanner but this area can be increased by combining the information of additional external laser scanners.

Evaluation of a LiDAR-based 3D-stereoscopic vision system for crop-monitoring applications

“…5, even if there is a measurement noise on the background (Lee and Ehsani, 2008;Teixidó et al, 2012), the objects are clearly visible and recognizable, the overall shapes of the optical targets are fully matched. Thanks to the first flat part of the panel (rectangle 230 mm  150 mm, placed on the left part of the pictures of Fig.…”

“…In robotics, the LiDAR is used for perceiving the environment and/or classifying objects, e.g. in Surface Localization and Mapping activities, or for making an autonomous robot navigate in an agricultural environment (Hiremath et al, 2014;Teixidó et al, 2012). In forestry, it was used to map the forest biomass (Sun et al, 2011) or to estimate the bushy biomass in Mediterranean areas (Estornell et al, 2011).…”

Design, Implementation and Validation of the Three-Wheel Holonomic Motion System of the Assistant Personal Robot (APR)

“…Finally, Figure 27 shows the differences between the planned angular orientation of the mobile robot and the values estimated according the SLAM procedure and according the information of the encoders and the kinematic model which are always lower than 5° in all trajectories measured in this first validation experiment. The displacement estimated with the information of the encoders has been also compared with manual measurements and with measurements obtained with an external LIDAR [27] obtaining similar results than the displacement estimated with the SLAM procedure. However, the use of the SLAM onboard procedure has the advantage of an easy synchronization between the trajectories estimated with both methods.…”

Lidar-Based Relative Position Estimation and Tracking for Multi-robot Systems

“…Teixid et al estimated position of circles from a laser scan, stating that attaching a circular marker to a mobile platform facilitates its detection [1]. Yet, their sensor was static and external to the robot, and the experiments limited to a case when the robot has been moved manually, not reflecting its real, dynamic motion.…”