Extended Kalman Filter Fusion Research Articles

Data fusion method for aircraft surveillance in flight zone based on Trans-Attention

Aiming at the problem of low monitoring accuracy and position jump of single monitoring source of aircraft in the flight zone, a method of aircraft monitoring data fusion based on Transformer and attention mechanism is proposed. Firstly, the encoder structure of Transformer is used to extract features of each monitoring source data respectively, and then weight values are assigned to different monitoring sources through the attention mechanism. Finally, regression calculation is performed through the fully connected network to obtain the final fusion result. The monitoring data of the surface surveillance radar and the broadcast automatic dependent surveillance system are selected as the fusion source, and the multi-point positioning data is used as the true label. The experimental results show that this method effectively reduces the monitoring error of a single monitoring source, and the fusion effect is better than the long short-term memory network, recurrent neural network and extended Kalman filter fusion method based on the attention mechanism, and the mean absolute error is improved by 2.20%、14.32%and respectively 33.94%.

The Influence of Temporal Disturbances in EKF Calculations on the Achieved Parameters of Flight Control and Stabilization of UAVs.

This article investigates the causes of occasional flight instability observed in Unmanned Aerial Vehicles (UAVs). The issue manifests as unexpected oscillations that can lead to emergency landings. The analysis focuses on delays in the Extended Kalman Filter (EKF) algorithm used to estimate the drone's attitude, position, and velocity. These delays disrupt the flight stabilization process. The research identifies two potential causes for the delays. First cause is magnetic field distrurbances created by UAV motors and external magnetic fields (e.g., power lines) that can interfere with magnetometer readings, leading to extended EKF calculations. Second cause is EKF fusion step implementation of the PX4-ECL library combining magnetometer data with other sensor measurements, which can become computionally expensive, especially when dealing with inconsistent magnetic field readings. This can significantly increase EKF processing time. The authors propose a solution of moving the magnetic field estimation calculations to a separate, lower-priority thread. This would prevent them from blocking the main EKF loop and causing delays. The implemented monitoring techniques allow for continuous observation of the real-time operating system's behavior. Since addressing the identified issues, no significant problems have been encountered during flights. However, ongoing monitoring is crucial due to the infrequent and unpredictable nature of the disturbances.

Multi-sensor fusion based wheeled robot research on indoor positioning method

In response to the poor positioning performance and errors of the wheeled robot under a single sensor, a combination of wheel odometry dead reckoning, Inertial Measurement Unit (IMU) heading angle information, and map environment information obtained from LiDAR is used for indoor positioning of the wheeled robot. By using data from multiple sensors, errors are reduced and positioning accuracy is improved. The results show that combining the Extended Kalman Filter (EKF), Gmapping algorithm, and Adaptive Monte Carlo Localization (AMCL) reduces the relative error by 8.35 % compared to the single wheel odometry heading calculation method. Compared with the EKF fusion method for dead reckoning and inertial measurement unit heading angle information, the relative error is reduced by 4 %, and there is no cumulative trend in angle error. This effectively addresses the challenge of cumulative errors in indoor positioning within environments that lack base stations, thereby enhancing accuracy and reliability in such specialized conditions.

Pose Measurement Technology of Roadheader Body based on Fusion of Visual and SINS*

In order to solve the problem of pose measurement of roadheader body in low illumination and high dust environment in coal mine, a pose measurement technology of roadheader body based on visual and strapdown inertial navigation system (SINS) is proposed. By extracting the point and line features and using the monocular vision positioning principle based on the gate three lines, the spatial pose of the roadheader body measured by vision is obtained according to the spatial matrix transformation. At the same time, the spatial pose of the roadheader body measured by SINS is calculated by gyroscope and accelerometer. Then the least square method is used to align the two-sensor data, and the registration data is fused based on the extended Kalman filter fusion algorithm to obtain the final fusion roadheader pose data. The experimental results show that the measurement error of the roadheader body position in the x axis direction of the roadway coordinate system is less than ± 20 mm, the error of the y axis direction is less than ±35 mm, the error of the z axis direction is less than ± 10 mm, the yaw angle error is between-0.4° to 0.7°, the roll angle error is between -0.2° and 0.6°, and the pitch angle error is between -0.02° and 0.5°. This method can be used to measure the pose of the roadheader stably and accurately in the complex environment of high dust, miscellaneous light and low illumination.

Multiple Road-Objects Detection and Tracking for Autonomous Driving

In this paper, a real-time road-Object Detection and Tracking (LR_ODT) method for autonomous driving is proposed. The method is based on the fusion of lidar and radar measurement data, where they are installed on the ego car, and a customized Unscented Kalman Filter (UKF) is employed for their data fusion. The merits of both devices are combined using the proposed fusion approach to precisely provide both pose and velocity information for objects moving in roads around the ego car. Unlike other detection and tracking approaches, the balanced treatment of both pose estimation accuracy and its real-time performance is the main contribution in this work. The proposed technique is implemented using the high-performance language C++ and utilizes highly optimized math and optimization libraries for best real-time performance. Simulation studies have been carried out to evaluate the performance of the LR_ODT for tracking bicycles, cars, and pedestrians. Moreover, the performance of the UKF fusion is compared to that of the Extended Kalman Filter fusion (EKF) showing its superiority. The UKF has outperformed the EKF on all test cases and all the state variable levels (-24% average RMSE). The employed fusion technique show how outstanding is the improvement in tracking performance compared to the use of a single device (-29% RMES with lidar and -38% RMSE with radar).

Lidar and radar fusion for real-time road-objects detection and tracking

In this paper, based on the fusion of Lidar and Radar measurement data, a real-time road-Object Detection and Tracking (LR_ODT) method for autonomous driving is proposed. The lidar and radar devices are installed on the ego car, and a customized Unscented Kalman Filter (UKF) is used for their data fusion. Lidars are accurate in determining objects’ positions but significantly less accurate on measuring their velocities. However, Radars are more accurate on measuring objects velocities but less accurate on determining their positions as they have a lower spatial resolution. Therefore, the merits of both sensors are combined using the proposed fusion approach to provide both pose and velocity data for objects moving in roads precisely. The Grid-Based Density-Based Spatial Clustering of Applications with Noise (GB-DBSCAN) clustering algorithm is used to detect objects and estimate their centroids from the lidar and radar raw data. Then, the estimation of the object’s velocity as well as determining its corresponding geometrical shape is performed by the RANdom SAmple Consensus (RANSAC) algorithm. The proposed technique is implemented using the high-performance language C+⁣+ and utilizes highly optimized math and optimization libraries for best real-time performance. The performance of the UKF fusion is compared to that of the Extended Kalman Filter fusion (EKF) showing its superiority. Simulation studies have been carried out to evaluate the performance of the LR_ODT for tracking bicycles, cars, and pedestrians.

Novel indoor positioning algorithm based on Lidar/inertial measurement unit integrated system

As an important research field of mobile robot, simultaneous localization and mapping technology is the core technology to realize intelligent autonomous mobile robot. Aiming at the problems of low positioning accuracy of Lidar (light detection and ranging) simultaneous localization and mapping with nonlinear and non-Gaussian noise characteristics, this article presents a mobile robot simultaneous localization and mapping method that combines Lidar and inertial measurement unit to set up a multi-sensor integrated system and uses a rank Kalman filtering to estimate the robot motion trajectory through inertial measurement unit and Lidar observations. Rank Kalman filtering is similar to the Gaussian deterministic point sampling filtering algorithm in structure, but it does not need to meet the assumptions of Gaussian distribution. It completely calculates the sampling points and the sampling points weights based on the correlation principle of rank statistics. It is suitable for nonlinear and non-Gaussian systems. With multiple experimental tests of small-scale arc trajectories, we can see that compared with the alone Lidar simultaneous localization and mapping algorithm, the new algorithm reduces the mean error of the indoor mobile robot in the X direction from 0.0928 m to 0.0451 m, with an improved accuracy rate of 46.39%, and the mean error in the Y direction from 0.0772 m to 0.0405 m, which improves the accuracy rate of 48.40%. Compared with the extended Kalman filter fusion algorithm, the new algorithm reduces the mean error of the indoor mobile robot in the X direction from 0.0597 m to 0.0451 m, with an improved accuracy rate of 24.46%, and the mean error in the Y direction from 0.0537 m to 0.0405 m, which improves the accuracy rate of 24.58%. Finally, we also tested on a large-scale rectangular trajectory, compared with the extended Kalman filter algorithm, rank Kalman filtering improves the accuracy of 23.84% and 25.26% in the X and Y directions, respectively, it is verified that the accuracy of the algorithm proposed in this article has been improved.

An efficient tuning framework for Kalman filter parameter optimization using design of experiments and genetic algorithms

The Extended Kalman Filter (EKF) is currently a dominant method of sensor fusion used for navigation of mobile devices, robotics and autonomous vehicles. One navigation system involves the EKF fusion of an Inertial Navigation System (INS) with a Global Navigation Satellite System (GNSS) to perform 3D pose estimation, which is essential to practical applications like autonomous vehicles and UAVs. This system involves using the INS to predict pose changes and uses GNSS measurements when available to correct for estimation drifts and sensor errors. The performance of the state estimation is heavily dependent on the accurate selection of EKF parameters, leading to the optimal selection of parameters being a critical factor in the design and use of the EKF. In this paper, a methodical and efficient method of EKF parameter tuning is presented. The tuning framework uses nominal parameters generated by Gauss Markov (GM) and Allan Variance (AV) methods that are tuned by Genetic Algorithms (GA) accelerated by a Design of Experiment (DoE) technique to efficiently optimize EKF parameters. This framework has been implemented in MATLAB and tested using simulations and real data. The results demonstrate that GA tuned parameters increases accuracy substantially, and that the DoE technique consistently improves the convergence behavior of the GA.

Indoor Location Method of WiFi / PDR Fusion Based on Extended Kalman Filter Fusion

This paper proposes an indoor positioning method based on extended Kalman filter WiFi-PDR fusion, which aims to improve the accuracy and stability of indoor positioning. In this method, the mobile terminal collects the WiFi fingerprint location information and establishes the fingerprint database. At the same time, using the accelerometer, gyroscope and magnetometer in the mobile terminal, the walking state of the pedestrian is judged by adjusting the dynamic threshold, and the direction detection is completed. After that, adaptive Kalman filter is used to integrate the WiFi location system and the PDR location system to update the user’s location. The results show that the scheme reduces the accumulated error of PDR positioning to a certain extent, and improves the continuity and stability of WiFi Positioning. Therefore, the scheme we propose can effectively improve the positioning accuracy.

Road-objects tracking for autonomous driving using lidar and radar fusion

Abstract In this paper, based on the fusion of Lidar and Radar measurement data, a real-time road-Object Detection and Tracking (LR_ODT) method for autonomous driving is proposed. The lidar and radar devices are installed on the ego car, and a customized Unscented Kalman Filter (UKF) is used for their data fusion. Lidars are accurate in determining objects’ positions but significantly less accurate on measuring their velocities. However, Radars are more accurate on measuring objects velocities but less accurate on determining their positions as they have a lower spatial resolution. Therefore, the merits of both sensors are combined using the proposed fusion approach to provide both pose and velocity data for objects moving in roads precisely. The Grid-Based Density-Based Spatial Clustering of Applications with Noise (GB-DBSCAN) clustering algorithm is used to detect objects and estimate their centroids from the lidar and radar raw data. Then, the estimation of the object’s velocity as well as determining its corresponding geometrical shape is performed by the RANdom SAmple Consensus (RANSAC) algorithm. The proposed technique is implemented using the high-performance language C++ and utilizes highly optimized math and optimization libraries for best real-time performance. The performance of the UKF fusion is compared to that of the Extended Kalman Filter fusion (EKF) showing its superiority. Simulation studies have been carried out to evaluate the performance of the LR ODT for tracking bicycles, cars, and pedestrians.

An improved CI EKF data fusion algorithm for multi-sensor time-delay system

In order to solve the problem of time-delay in non-linear multi-sensor information fusion, a simulation model of moving target tracking in sensor networks with the time-delay state and observation system is established. Using the augmented matrix to transform the time-delay system into the non-time-delay system, an improved Covariance Intersection (CI) Extended Kalman filter (EKF) data fusion algorithm for multi-sensor systems with time-delay is presented. This method avoids calculating any two local filter error cross-covariance matrices and greatly reduces the computational complexity and time. Analysing the precision of this method, comparing the precision of improved CI EKF data fusion algorithm and the locally optimal fusion EKF algorithm. The results show that the precision of improved CI EKF data fusion algorithm is higher than that of the local EKF and close to the precision of the optimal EKF fusion.

Beidou navigation method based on intelligent computing and extended Kalman filter fusion

Scientific and precise dynamic navigation is the key to improving Beidou positional accuracy of agricultural machinery. Aiming at the gross error of agricultural machinery location. First, the paper deeply explores the principle of Beidou navigation. Second, according to the PVT information (position, velocity and time) solutions of Beidou navigation system, the least square method, Kalman filter method and extended Kalman filter method were studied. Based on their own advantages, algorithms were proposed that combines the differential adaptation and extended Kalman filter. Then, based on the equivalent gain matrix and iterative solution, a robust adaptive Kalman filter model is built to verify its effectiveness in reducing gross errors. At last, the four algorithms were simulated in MATLAB and the simulation results were compared to verify that the newly-proposed method is the optimal solution algorithm. The absolute error remained 5.2 cm, meeting the preciseness limit of the agricultural machinery navigation.

Collaborative Mapping and Autonomous Parking for Multi-Story Parking Garage

We present a novel collaborative mapping and autonomous parking system for semi-structured multi-story parking garages, based on cooperative 3-D LiDAR point cloud registration and Bayesian probabilistic updating. First, an inertial-enhanced (IE) generalized iterative closest point (G-ICP) approach is presented to perform high accuracy registration for LiDAR odometry, which is loosely coupled with inertial measurement unit using multi-state extended Kalman filter fusion. Second, the IE G-ICP is utilized to reconstruct the 3-D point cloud model for each vehicle, and then the individual model maps are merged and updated into a global probabilistic 2-D grid map. A collaborative multiple layer semantic map is constructed to support autonomous parking. Finally, we propose a collaborative navigation approach for path planning when there are multiple vehicles in the parking garage through vehicle-to-vehicle communication. A global path planner is designed to explore the minimum cost path based on the semantic map, and local motion planning is performed using a random exploring algorithm for obstacle avoidance and path smoothing. Our pilot experimental evaluation provides a proof of concept for indoor autonomous parking by collaborative perception, map merging, and updating methodologies.

An indoor mobile robot navigation technique using odometry and electronic compass

A novel method of indoor mobile robot navigation is presented. The proposed approach fuses the data of odometry and electronic compass for navigation. It includes two calibration methods and a fusion algorithm. First of all, calibration method of systematic odometry error is used to reduce the error of navigation and provide the reliable estimate of pose of mobile robot for adaptive extended Kalman filter fusion algorithm later. Secondly, calibration method of electronic compass using an adaptive neural fuzzy inference system provides direction angle of mobile robot as observation for adaptive extended Kalman filter algorithm later. Finally, a fusion algorithm using adaptive extended Kalman filter algorithm fuses data of odometry and electronic compass that provides the position and orientation of mobile robot. In addition, the value of the parameter k of adaptive extended Kalman filter algorithm which is related to the process noise covariance is decided by fuzzy algorithm. In order to illustrate the feasibility of the proposed approach, two types of experiments are done: the first-type experiment is that the mobile robot runs along default path only with odometry, and the mobile robot with odometry and electronic compass in the second-type experiment utilizes the proposed approach for navigation. The results of experiments show that the error of localization and navigation in the first-type experiment is larger than one in the second-type experiment. They prove the good performance of the proposed approach.

Fusion Estimation Algorithm with Uncertain Noises and Its Application in Navigation System

In order to solve the problem of uncertain noise during the measurement of actual system, an extended Kalman filter fusion estimation method based on multisensor fusion algorithm with uncertain effects is proposed. Then the equivalent measurement and the corresponding error matrix are estimated by the proposed uncertain fusing algorithm. Submit the results into the system model for filter processing and the optimal estimation can be obtained by the filtering method. Finally, the algorithm is verified in the GPS/INS navigation system which shows that the fusion result with uncertainty effect is much better than then fusion result with independent noise due to the consideration of correlated noise and uncertain effects for the actual system. This is also validates the effectiveness and practicality of the proposed algorithm.