Towards a Model Based Sensor Measurement Variance Input for Extended Kalman Filter State Estimation

Abstract

In this paper, we present an alternate method for the generation and implementation of the sensor measurement variance used in an Extended Kalman Filter (EKF). Furthermore, it demonstrates the limitations of a conventional EKF implementation and postulates an alternate form for representing the sensor measurement variance by extending and improving the characterisation methodology presented in the previous work. As presented in earlier work, the use of surveying grade optical measurement instruments allows for a more effective characterisation of Ultra-Wide Band (UWB) localisation sensors; however, in cluttered environments, the sensor measurement variance will change, making this method not robust. To compensate for the noisier readings, an EKF using a model based sensor measurement variance was developed. This approach allows for a more accurate representation of the sensor measurement variance and leads to a more robust state estimation system. Simulations were run using synthetic data in order to test the effectiveness of the EKF against the originally developed EKF; next, the new EKF was compared to the original EKF using real world data. The new EKF was shown to function much more stably and consistently in less ideal environments for UWB deployment than the previous version.

A Comparison of Local Path Planning Techniques of Autonomous Surface Vehicles for Monitoring Applications: The Ypacarai Lake Case-study

“…The alteration point and a radius are also added and considered for solving the algorithm. Moreover, instead of the usual calling of update_ f mm() function, an update_ f mm() function (found at lines 3 and 5) is used, which adds the functionality of modifying strictly the previous map through the use of the Equation (9). It is also important to note that a function is added to apply a Gaussian filter (lines 4 and 6 of Algorithm 9), to smooth the result, which is necessary to improve the costs calculated for arrival times and the response of the descending gradient.…”

“…While these systems work closely together, methods and techniques are not similar. Although this work focuses on motion planning techniques, it is worth mentioning some localization techniques, which in general are crucial in real-life scenarios, as the ones described in [8], which carefully characterizes the error of the position estimation of an AGV using three different methods, using as ground truth a robotic total station: odometry, extended Kalman filters ( [9]) and ultra-wideband localization systems. In respect to motion path planning approaches for ASV, in [10] these techniques have been classified in different levels.…”

LocSpeck: A Collaborative and Distributed Positioning System for Asymmetric Nodes Based on UWB Ad-Hoc Network and Wi-Fi Fingerprinting

“…Since non-line-of-sight (NLOS) measurements are quite frequent in indoor environments, several recent works consider the problem of identifying NLOS measurements [20] or dynamically adapting the measurement variance in the EKF in order to reduce the effect of outliers [21]. Recent feature-based approaches provided encouraging results on the NLOS identification and mitigation by properly analyzing the characteristics of the received UWB signal [19,22].…”

“…The accuracy of the obtained position estimates depends on the geometry of the network nodes [18], and it can be assessed by means of the geometric dilution of precision [19]. Several commercial and research positioning systems, e.g., the Pozyx system, are using a fixed UWB network architecture in order to properly track moving nodes [17].Since non-line-of-sight (NLOS) measurements are quite frequent in indoor environments, several recent works consider the problem of identifying NLOS measurements [20] or dynamically adapting the measurement variance in the EKF in order to reduce the effect of outliers [21]. Recent feature-based approaches provided encouraging results on the NLOS identification and mitigation by properly analyzing the characteristics of the received UWB signal [19,22].…”

An EKF-Based Method and Experimental Study for Small Leakage Detection and Location in Natural Gas Pipelines

“…Continuous nonlinear equations need to be linearized first when using EKF. The EKF has the advantages of fast convergence and high accuracy in state estimation [68][69][70][71]. This paper proposes an EKF-based method for small leakage detection and location in natural gas pipelines.Most researchers working in this topic approach the leakage detection problem from the research field of control.…”