Distributed Multi-Antenna Positioning for Automatic-Guided Vehicle

Abstract

Radio-based positioning systems are typically utilized to provide high-precision position information for automatic-guided vehicles (AGVs). However, the presence of obstacles in harsh environments, as well as carried cargoes on the AGV, will degrade the localization performance, since they block the propagation of radio signals. In this paper, a distributed multi-antenna positioning system is proposed, where multiple synchronous antennas are equipped on corners of an AGV to improve the availability and accuracy of positioning. An estimator based on the Levenberg–Marquardt algorithm is introduced to solve the nonlinear pseudo-range equations. To obtain the global optimal solutions, we propose a coarse estimator that utilizes the displacement knowledge of the antennas to provide a rough initial guess. Simulation results show a better availability of our system compared with the single antenna positioning system. Decimeter accuracy can be obtained under a Gaussian measurement noise with a standard deviation of 0.2 m. The results also demonstrate that the proposed algorithm can achieve positioning accuracy close to the theoretical Cramer–Rao lower bound. Furthermore, given prior information of the yaw angle, the same level of accuracy can be obtained by the proposed algorithm without the coarse estimation step.

UWB-Based Safety System for Autonomous Guided Vehicles Without Hardware on the Infrastructure

“…As explained above, RTLSs can help AGVs navigate safely indoors. There are many works in the literature that propose using these location systems in AGV navigation [6], [7], [10]- [14], [16]- [20]. In this section, we will overview the main characteristics of the current RTLS-based safety systems for AGVs.…”

“…Recently, [20] proposed placing a bigger number of nodes in the AGV to improve the availability and accuracy of the AGV positioning estimates in the situation of signal blockage caused by obstacles and carried cargoes. Nevertheless, in all these works, some nodes (anchors) were installed on the plant infrastructure so that the RTLS could provide the position of a target node placed in the AGV.…”

Closed-form Two-way TOA Localization and Synchronization for User Devices with Motion and Clock Drift

“…Note that although (8) has the same form, the variables A, y, G, g and U are different from those in [32] due to the two-way TOA scenario, which brings doubled number of measurements and leads to more complex processing of the measurements.…”

“…L OCALIZATION and synchronization (LAS) techniques provide position and timing information, which is significant to a variety of real-world applications such as Internet of Vehicles, Internet of Things (IoT), emergency rescue and surveillance reconnaissance [1], [2]. Among the measurements such as time-of-arrival (TOA), angle-of-arrival (AOA) and received signal strength (RSS) [3]- [8], TOAs between the anchor nodes (ANs) and a user device (UD) are widely adopted in LAS and different types of methods have been developed to solve the LAS problem [9]- [18]. A typical example of such a scheme is the widely used Global Positioning System (GPS) [19]- [21].…”

Optimal TOA Localization for Moving Sensor in Asymmetric Network

“…To locate a sensor node (SN), measurements such as time-of-arrival (TOA), directionof-arrival (DOA), received signal strength (RSS) between the SN and several anchor nodes (ANs) need to be obtained [1,2,3,4,5]. The TOA-based localization is adopted in numerous modern systems and applications such as global navigation satellite system (GNSS), Radar, acoustic/ultra-sound based tracking, ultra-wide band (UWB) indoor localization, wireless sensor networks (WSN) and Internet of Things (IoT) localization [6,7,8].…”