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This communication proposes to re-consider the localization problem (i.e. the configuration estimation) of a moving car as the state estimation of a discrete-time non-linear process. The use of set-theoretic concepts for state estimation is presented under the form of the computation of the direct and reverse images of a set by a function using interval analysis. One simplification of the computation...
Low-cost navigation systems, deployed for ground vehicles' applications, are designed based on the loosely coupled fusion between the global positioning system (GPS) and the inertial measurement unit (IMU). However, low-cost GPS receivers provide the position and velocity of the vehicle at a lower sampling rate than the IMU-sampled vehicle dynamics. In addition, the GPS measurements might be missed...
The aim of this paper is to present a method for integration of measurements provided by inertial sensors (gyroscopes and accelerometers), GPS and a video system in order to estimate position and attitude of an UAV (Unmanned Aerial Vehicle). Inertial sensors are widely used for aircraft navigation because they represent a low cost and compact solution, but their measurements suffer of several errors...
Global Navigation Satellite Systems (GNSS) offer a great value for many location-based services and applications. However, due to their limitations in terms of coverage, continuity, accuracy and integrity, GNSS are often fused with some extra aiding sensors. To perform the data fusion of multiple sensors it is possible to find in the literature of the field a large number of approaches that claim...
Motorized floating sensors have distinct advantages over their non-actuated counterparts. A motorized unit can prevent the sensor from washing ashore or heading into dangerous areas, expanding the mission regions in which they can be feasibly operated. In this article, we present a control framework and describe the physically realized system used to prove its effectiveness. The controller uses two...
In this paper, we propose a vision-based control system for the localization of an unmanned aerial vehicle (UAV) which equips on-board cameras. The proposed approach is combined a visual odometer with inertial measurement from IMU and pressure signal which compensate attitude and altitude, respectively. For the autonomous control of a UAV, we consider only natural landmarks provided by a feature tracking...
Indoor location-based applications have a broad appeal for development in navigation, robotics, gaming, asset tracking, networking, and more. GPS technologies have been successfully leveraged for outdoor navigation, but often lose effectiveness indoors due to a more constrained environment, possible loss of signal, lack of elevation information and need for better accuracy. This paper presents our...
Real-time image georeferencing technologies are required to generate spatial information promptly from the image sequences acquired by an airborne multi-sensor system. We thus develop a sequential aerial triangulation (AT) algorithm based on the combined adjustment model. The proposed algorithm enables us to perform AT rapidly with a minimum of computation at the current stage using the computational...
The vehicle's localization is classically achieved by Bayesian methods like Extended Kaiman Filtering. Such a method provides an estimated position with its associated uncertainty. Bounded-error approaches using interval analysis work in a different way as they provide a possible set of positions. An advantage of such approaches is that the results are guaranteed and are not probabilistically defined...
In this article, we investigate the impact of redundant MEMS-IMU on a loosely coupled INS/GBAS system. Therefore, we considered and analyze the combined performance of three identically and orthogonally mounted low-cost IMUs. It is shown that due to the redundancy, the INS based position error is reduced by an average factor of two. In conventional GBAS, no position solution can be obtain while GPS...
Localization is one of the most important issues in Wireless Sensor Networks (WSNs). A lot of effort has been devoted to this issue which can be broadly classified into two categories: range-based schemes and range-free schemes. This paper proposes a range-free localization scheme by utilizing mobile anchors. Each mobile anchor is assumed to be able to know its current position with specific hardware...
We have built a test unit containing a GPS, an inertial measurement unit, magnetometers and a barometer. When the GPS looses its signals, the other sensors are used to keep track of the position. Unscented Kalman filters have been used to test the performance of different aid sensor configurations. In addition to the four different sensor configurations, the gyroscope output was filtered, making it...
This paper addresses the development of a new generation of lightweight intelligent buoys. These buoys are used to support underwater acoustic positioning systems, but were also designed to be elements of portable coastal observatories for short term deployments. We will present the main features of a buoy prototype including the physical structure, the computational system and algorithms developed...
In this paper, vehicle state variables and bank angle estimation for rolling stability control (RSC) is proposed using one accelerometer and two gyro sensors, instead of using inertial navigation system (INS) or global positioning system (GPS). We proposed a novel robust RSC for in-wheel motor electric vehicle (IMEV) using differential torque by right and left motors which are controlled independently...
We present a method for assimilating Lagrangian sensor measurement data into a shallow water equation model. Using our method, the variational data assimilation problem is formulated as a quadratic programming problem with linear constraints. Drifting sensors that gather position and velocity information in the modeled system can then be used to refine the estimate of the initial conditions of the...
In this article, we investigate real-time estimation of flow state in open channels using the measurements obtained from Lagrangian sensors (drifters). One-dimensional Shallow Water Equations (SWE), also known as Saint-Venant equations, are used as the mathematical model for the flow. After linearizing and discretizing the PDEs using an explicit linear scheme, we construct a linear state-space model...
A new version of the extended Kalman filter (EKF) is proposed for nonlinear systems possessing symmetries. Instead of using a linear correction term based on a linear output error, it uses a geometrically adapted correction term based on an invariant output error; in the same way the gain matrix is not updated from of a linear state error, but from an invariant state error. The benefit is that the...
This paper discusses the problem of joint location and orientation estimation of a receiver using only angle of arrival (AOA) information. Conventional formulations of the problem consist of a number of nonlinear equations where the number of unknowns exceeds the number of equations. However, formulations presented in this paper simplifies the problem in a way that leads of efficient solutions. Two...
This paper describes the adaptive extended Kalman filtering which is applied to low-cost MEMS IMU/GPS integration. Unmanned Aerial Vehicles are versatile flying machine capable of handling both military and civilian missions. The availability of low-cost MEMS IMU has made it possible to construct inexpensive, integrated systems for usage in UAV applications. The adaptive extended Kalman filtering...
Attitude and heading reference system (AHRS) is a three dimensional measurement package including micro-inertial measurement units (MIMUs) and magnetic sensors. The parameter model for low cost tightly-coupled AHRS/INS is established due to the large drifts of micro inertial sensors, which are consist of micro gyros and micro accelerometers. Differing from the traditional extended Kalman filter (EKF)...
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