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To validate the accuracy and reliability of onboard sensors for object detection and localization for driver assistance, as well as autonomous driving applications under realistic conditions (indoors and outdoors), a novel tracking system is presented. This tracking system is developed to determine the position and orientation of a slow-moving vehicle during test maneuvers within a reference environment (e.g., car during parking maneuvers), independent of the onboard sensors. One requirement is a 6 degree of freedom (DoF) pose with position uncertainty below 5 mm (3σ), orientation uncertainty below 0.3° (3σ), at a frequency higher than 20 Hz, and with a latency smaller than 500 ms. To compare the results from the reference system with the vehicle’s onboard system, synchronization via a Precision Time Protocol (PTP) and system interoperability to a robot operating system (ROS) are achieved. The developed system combines motion capture cameras mounted in a 360° panorama view setup on the vehicle, measuring retroreflective markers distributed over the test site with known coordinates, while robotic total stations measure a prism on the vehicle. A point cloud of the test site serves as a digital twin of the environment, in which the movement of the vehicle is visualized. The results have shown that the fused measurements of these sensors complement each other, so that the accuracy requirements for the 6 DoF pose can be met while allowing a flexible installation in different environments.

Abstract: Emerging wireless remote sensing technologies offer significant potential to advance the management of construction processes by providing real-time access to the locations of workers, materials, and equipment. Unfortunately, little is known regarding the accuracy, reliability, and practical benefits of an emerging technology, effectively impeding widespread adoption. This paper evaluates a commercially-available Ultra Wideband (UWB) system for real-time, mobile resource location tracking in harsh construction environments. A focus of this paper is to measure the performance of the UWB technology for tracking mobile resources in real-world construction settings. To assess tracking accuracy, location error rates for select UWB track signals are obtained by automatically tracking a single entity using a Robotic Total Station (RTS) for ground truth. Furthermore, to demonstrate the benefits of UWB technology, the paper provides case studies of resource tracking for analysis of worksite operations. The work demonstrates the applicability of UWB for the design of construction management support tools. [Copyright &y& Elsevier]

Abstract: The Robotic Theodolite or Robotic Total Station (RTS) is a new generation geodetic instrument that can automatically record the changing coordinates of a moving target (reflector). RTS was so far used for monitoring of static and very slow displacements. This limitation was imposed by some characteristics of these instruments (real sampling rate <2 Hz and non-constant, noisy results in high frequency sampling, etc.). A study of a new generation of RTS based on: (1) systematic experiments using an apparatus producing oscillations of known, computer-determined characteristics (frequency and amplitude of oscillation) which were compared with those recorded by the RTS; (2) upgrading of the instrument’s built-in software to display measurements with a 0.01 s resolution; and (3) spectral analysis of the obtained non-equidistant data with a least-squares based software without prior interpolations, permitted us to show that the range of application of RTS may be safely extended to higher frequency oscillations. In particular, it was shown that: (1) the maximum real sampling rate of RTS is 6–7 Hz, but since sampling rate is variable, aliasing-free results can be obtained above the Nyquist frequency. (2) The potential to record oscillations depends on the maximum angular velocity of the instrument and on the maximum velocity of the moving target; for velocities up to about 10 cm/s in field studies, results are very precise. On the contrary, for targets moving with maximum velocities > 15 cm/s, some displacements cycles are not well-defined or are lost, and hence, the accuracy of the oscillation amplitude and frequency are lower. (3) RTS can be used to measure small (on the order of a few mm) amplitudes of oscillation, and to some degree of frequencies of oscillation of various relatively stiff engineering structures (modal frequencies > 1 Hz, up to 3–4 Hz). This potential is demonstrated on the basis of several field examples, including the monitoring of two bridges with dominant modal frequencies > 1.5 Hz. Obviously, these limits reflect the most unfavorable cases of application of RTS, and higher period/larger amplitude oscillations or other deflections can be successfully measured if the main requirement for this type of instrument is satisfied: an unobstructed view of a reflector at a maximum distance of a few hundred meters from an RTS set on stable ground. [Copyright &y& Elsevier]

To validate the accuracy and reliability of onboard sensors for object detection and localization for driver assistance, as well as autonomous driving applications under realistic conditions (indoors and outdoors), a novel tracking system is presented. This tracking system is developed to determine the position and orientation of a slow-moving vehicle during test maneuvers within a reference environment (e.g., car during parking maneuvers), independent of the onboard sensors. One requirement is a 6 degree of freedom (DoF) pose with position uncertainty below 5 mm (3σ), orientation uncertainty below 0.3° (3σ), at a frequency higher than 20 Hz, and with a latency smaller than 500 ms. To compare the results from the reference system with the vehicle's onboard system, synchronization via a Precision Time Protocol (PTP) and system interoperability to a robot operating system (ROS) are achieved. The developed system combines motion capture cameras mounted in a 360° panorama view setup on the vehicle, measuring retroreflective markers distributed over the test site with known coordinates, while robotic total stations measure a prism on the vehicle. A point cloud of the test site serves as a digital twin of the environment, in which the movement of the vehicle is visualized. The results have shown that the fused measurements of these sensors complement each other, so that the accuracy requirements for the 6 DoF pose can be met while allowing a flexible installation in different environments. [ABSTRACT FROM AUTHOR]