Height Measurement in Seamless Indoor/Outdoor Infrastructure-Free Navigation

Abstract

Using the barometer for height estimation often requires the use of external reference to correct biases in measurement. These biases are often caused by the change of the ambient pressure environment. The barometric height estimation is especially challenging in tactical and rescue applications where high temperatures or sudden large pressure shocks can change the pressure rapidly. We assess the suitability of barometers for infrastructure-free navigation in tactical applications. First, this paper investigates the effect of transition in seamless indoor/outdoor navigation. Second, we measure the effects of pressure shocks, caused by explosions or firearms, on low-cost and lightweight micro-electromechanical barometers to ensure that the sensors are capable of operating under these conditions. Finally, we investigate the use of sonar measurement to estimate the vertical speed as an alternative to the reference barometer for infrastructure-free navigation. The fusion of barometer and sonar achieved on average 0.46-m root-mean-square error (RMSE) while simple barometric height estimation had a RMSE of 0.65 m. The fusion method had no errors over 1.5 m during the test. This accuracy is generally sufficient to find the correct floor level which is crucial for tactical situational awareness. The goal of this paper is to develop the methods for seamless indoor/outdoor navigation, and therefore the most important result of this paper is that the error caused when transitioning between outdoor and indoor environments is visibly reduced.

Ubiquitous UWB Ranging Error Mitigation With Application to Infrastructure-Free Cooperative Positioning

“…The poor navigation accuracy in vertical direction is typical to PDR, where the height solution generally tends to drift upwards. Including other sensors to the fusion, such as barometer, enables more accurate height estimation [22], [51].…”

UAV Swarm-Enabled Localization in Isolated Region: A Rigidity-Constrained Deployment Perspective

“…We assume that all GTs and UAVs have the same altitude H G and H A , which can be accurately measured with some mature equipment like barometers [13], while our results can be easily extended to a more general case with different altitudes and the corresponding errors. Besides, we assume the UAVs in the swarm and the aerial reference stations (ARS) are both quadrotor platforms and hover at a fixed altitude H A to provide a relatively stable anchor location during the ranging process.…”

“…In our proposed DE-based method, the a-th individual in the l-th iteration represents the UAV swarm deployment V l,a ∈ R |V|×2 . According to problem (P1), the fitness function used for evaluating the individual solutions is defined as fit (V l,a ) = (α Loc β Loc + α Safe β Safe + α Rig β Rig ) −1 (13) where β Loc is the maximum CRLB of the GTs corresponding to V l,a ; β Safe and β Rig are the penalty terms of C3 and C4, respectively. Once V l,a fails to guarantee the safety and rigidity constraint of the swarm, we set β Safe = 1 and β Rig = 1, otherwise, both values are set to zero.…”

Intelligent Positioning for a Commercial Mobile Platform in Seamless Indoor/Outdoor Scenes based on Multi-sensor Fusion

“…Providing pedestrians and vehicles with continuous positioning is a challenging but important topic [1,2,3]. In infrastructure-free navigation, it is necessary for mobile platform to provide accurate positioning in seamless indoor/outdoor occasions based on all the required sensors [4,5,6].…”