Software calibration for AK8963 magnetometer based on optimal ellipsoidal fitting

With the rapid development of mechatronics, systems in package (SiP), in particular the MPU-9250 inertial measurement Unit 9DOF (MPU-6050 6DOF and AK8963 3DOF), are becoming ubiquitous in applications for autonomous navigation purposes. Nevertheless, they suffer from some accuracy problems related to axis misalignment, disturbances, and deviation over time that make them unable to work autonomously for a long time. This paper will present a simple and practical calibration method using a least-squares based ellipsoid fitting method to calibrate and compensate for the error interference of the AK8963 sensor. Towards the end of this paper, a comparison between before and after the calibration is presented to study the software compensation effect and the stability of the magnetic sensor under study

Evaluating indoor positioning systems in a shopping mall : the lessons learned from the IPIN 2018 competition

The Indoor Positioning and Indoor Navigation (IPIN) conference holds an annual competition in which indoor localization systems from different research groups worldwide are evaluated empirically. The objective of this competition is to establish a systematic evaluation methodology with rigorous metrics both for real-time (on-site) and post-processing (off-site) situations, in a realistic environment unfamiliar to the prototype developers. For the IPIN 2018 conference, this competition was held on September 22nd, 2018, in Atlantis, a large shopping mall in Nantes (France). Four competition tracks (two on-site and two off-site) were designed. They consisted of several 1 km routes traversing several floors of the mall. Along these paths, 180 points were topographically surveyed with a 10 cm accuracy, to serve as ground truth landmarks, combining theodolite measurements, differential global navigation satellite system (GNSS) and 3D scanner systems. 34 teams effectively competed. The accuracy score corresponds to the third quartile (75th percentile) of an error metric that combines the horizontal positioning error and the floor detection. The best results for the on-site tracks showed an accuracy score of 11.70 m (Track 1) and 5.50 m (Track 2), while the best results for the off-site tracks showed an accuracy score of 0.90 m (Track 3) and 1.30 m (Track 4). These results showed that it is possible to obtain high accuracy indoor positioning solutions in large, realistic environments using wearable light-weight sensors without deploying any beacon. This paper describes the organization work of the tracks, analyzes the methodology used to quantify the results, reviews the lessons learned from the competition and discusses its future

Key Techniques for Traffic Information Acquisition Sensor Networks

University of Technology Sydney. Faculty of Engineering and Information Technology.Road traffic information acquisition technologies have the capability to provide important information for intelligent transportation systems (ITS) by employing sensor networks, especially for detecting the road network information in dots, sections or large-scale areas. Sensor network plays a vital role in acquiring road traffic information of ITS. By exploiting spatial-temporal models, traffic flow models or correlation models, the traffic information of road sections and networks can be derived from the traffic data of some key points in the road for the temporal and spatial correlation. Furthermore, because of the constraints of space-time correlation, project investment and construction cost, the investigation of traffic information acquisition by employing sensor network technologies has become an important research direction of ITS. As a result, the investigation of the theories, techniques, sensors, and methodologies of traffic information acquisition sensor network (TIASN) has been a significant research topic. Based on specific requirements on real time, accuracy and completeness for traffic information acquisition, this thesis has focused on the following key challenges: (1) new algorithm to acquire traffic flow based on multi-functional geomagnetic sensor; (2) efficient optimization methods for TIASN; (3) efficient calibration method for Inertial Measurement Unit (IMU); (4) effective testing method for urban rail transit sectional passenger flow. In this dissertation, motivated by the above challenges, a thorough investigation is presented on a novel multi-parameter sensing method of traffic information by using a multi-function geomagnetic sensor (MFGS). Furthermore, in order to improve the efficiency of IMU based traffic monitoring, the calibration and its associated experimental design schemes are developed for the two-key tri-axial sensors in an IMU, i.e. tri-axial magnetometers and tri-axial accelerometers. At the end, we study the short-term prediction methods of sectional passenger flow and selects Back-Propagation (BP) neural network combined with the characteristics of sectional passenger flow itself

Danae++: A smart approach for denoising underwater attitude estimation

One of the main issues for the navigation of underwater robots consists in accurate vehicle positioning, which heavily depends on the orientation estimation phase. The systems employed to this end are affected by different noise typologies, mainly related to the sensors and to the irregular noise of the underwater environment. Filtering algorithms can reduce their effect if opportunely con-figured, but this process usually requires fine techniques and time. This paper presents DANAE++, an improved denoising autoencoder based on DANAE (deep Denoising AutoeNcoder for Attitude Estimation), which is able to recover Kalman Filter (KF) IMU/AHRS orientation estimations from any kind of noise, independently of its nature. This deep learning-based architecture already proved to be robust and reliable, but in its enhanced implementation significant improvements are obtained in terms of both results and performance. In fact, DANAE++ is able to denoise the three angles describing the attitude at the same time, and that is verified also using the estimations provided by an extended KF. Further tests could make this method suitable for real-time applications in navigation tasks

Geodynamics and Geospatial Research: Conference Papers

Byggbranschen är, jämför med andra branscher konservativ. Förändringar, förbättringar och effektivisering sker men inte i den utsträckning och takt det borde. Under mitten av 1980-talet utvecklades en ny samarbetsform i USA och Storbritannien, som kom att kallas för Partnering. Vårt huvudsyfte med denna rapport är att se hur tillämpning av samarbetsformen partnering är inom småhusprojekt. Partnering är ett begrepp som används där man har gemensamma mål, öppenhet med öppna böcker och stor tillit för byggherrens bästa. Att försöka definiera partnering i Sverige har inte varit angeläget eftersom stora variationer i arbetssätt gjorts till respektive projekt. Tidigare studier i England, Danmark och USA har definierat partnering på dessa sätt. Ett partnering team skall bestå av projektledning, projektoptimering och produktion, för att åstadkomma ett gott resultat där alla strategiska leverantörer bidrar med den mest fördelaktiga och optimala lösningen. Man skall skilja på samverkansform, entreprenadform och ersättningsform. Samverkansform/partnering är en del av byggprojektets delar och kan användas vid alla entreprenad-, ersättning- och upphandlingsformer. Eftersom det kan vara besvärligt att ta fram ett riktpris med incitament så har man nu börjat använda en ersättningsmodell i form av budgetmodellen, modellen används av byggherrar som ofta bygger. Grundfilosofin för partnering är öppenhet, tillit, gemensamt uppsatta mål, tid, ekonomi och grupparbete. LEAN är ett produktionssystem som kommer ifrån japanska Toyota, även kallat TPS. Syn och tankesätt kring LEAN handlar om att effektivisera och öka produktiviteten. Ett tydligt exempel på detta är hur lastbilstillverkaren Scania har tillämpat och utvecklat produktionssystemet i sin dagliga verksamhet. Efter sammanställning av detta kandidatexamensarbete kan vi nu återkoppla och besvara vår problemformulering. Partnering är möjligt att tillämpa inom småhusprojekt, och är en bra metod för byggherren att medverka i och påverka tidplan, kvalitet samt budget. Tillämpningen av samverksformen partnering i ett enskilt småhusprojekt kan framstå som invecklat och ofta svårtillämpat. Vi har även fått nya infallsvinklar kring tillämpning av partnering i småhusprojekt, vilka kan vara intressanta för vidare studier.The construction industry is conservative compared with other industries. Modifications, improvements and efficiency improvements occur, but not to the extent and in the rate that it should. During the mid-1980s, a new form of cooperation was developed in the United States and in Great Britain, which came to be known as partnering. Our main purpose of this report is to see how the appliance of partnering is within a homebuilding project. Partnering is a concept used where there are common goals, openness with open books and great trust in the client's best. Trying to define partnering in Sweden has not been imperative since large variations in approaches have been done to respective project. Previous studies in Great Britain, Denmark and the United States have defined partnering on these ways. A partnering team shall consist of project management, project optimization and production, to achieve a good result where all strategic suppliers contribute with the most beneficial and optimal solution. One should distinguish between the form of collaboration, the form of contract and compensation terms. The form of collaboration/partnering is a part of the construction project parts and can be used for all contract-, replacement- and purchase forms. Because of the difficulty to produce a target price with incentives, it is known to use a compensation model in the form of a budget model. This model is often used by a developer who often builds. The basic philosophies of partnering are openness, trust, common goals, time, finances and team work. LEAN is a production system that comes from the Japanese Toyota, also known as TPS. Sights and thinking regarding LEAN is to render more effective and to increase the productivity. An example of this is how the truck manufacturer Scania has applied and developed the production system in their daily activity. Partnering is possible to apply within small house projects, and is a good method for the future proprietor to contribute in and to influence time flat, quality and budget. The application of the interacting mould partnering in an individual small house project can seem complicated and often difficult to apply. After the summary of this study, we can now re-engage and answer our problem wording. We have also received new insights about the application of partnering in homebuilding projects, which may be of interest for further study

Online Outdoor Terrain Classification Algorithm for Wheeled Mobile Robots Equipped with Inertial and Magnetic Sensors

Terrain classification provides valuable information for both control and navigation algorithms of wheeled mobile robots. In this paper, a novel online outdoor terrain classification algorithm is proposed for wheeled mobile robots. The algorithm is based on only time-domain features with both low computational and low memory requirements, which are extracted from the inertial and magnetic sensor signals. Multilayer perceptron (MLP) neural networks are applied as classifiers. The algorithm is tested on a measurement database collected using a prototype measurement system for various outdoor terrain types. Different datasets were constructed based on various setups of processing window sizes, used sensor types, and robot speeds. To examine the possibilities of the three applied sensor types in the application, the features extracted from the measurement data of the different sensors were tested alone, in pairs and fused together. The algorithm is suitable to operate online on the embedded system of the mobile robot. The achieved results show that using the applied time-domain feature set the highest classification efficiencies on unknown data can be above 98%. It is also shown that the gyroscope provides higher classification rates than the widely used accelerometer. The magnetic sensor alone cannot be effectively used but fusing the data of this sensor with the data of the inertial sensors can improve the performance

Development and Integration of MEMS Based Inductive Sensors

Inductive sensors are one of the most widely used sensors especially in automotive. However, with the current PCB manufacture process, the large size of the sensor limits its usage in different applications. In this thesis, a novel method of fabricating bi-layer copper micro inductive sensor is demonstrated to solve the size issue. The two coil layers were built by UV LIGA process respectively, and a polyimide insulation film sandwiched in between. At the beginning, seeding layer was deposited on the substrate as electrode, and then the copper coil layer was created through electroplating in the patterned micromold. The coil was prepared after striping off the seeding layer and micromold. Lately, the fabricated coil chips, ASIC, and capacitors were integrated together through PCB board by using wire bonding and SMT process. A reliable procedure of building robust micro inductive sensor was developed with the consideration of future mass production possibility. The good test results compared with simulation proved the feasibility of developing and fabricating miniaturized micro inductive sensor

Recent Advances in Indoor Localization Systems and Technologies

Despite the enormous technical progress seen in the past few years, the maturity of indoor localization technologies has not yet reached the level of GNSS solutions. The 23 selected papers in this book present the recent advances and new developments in indoor localization systems and technologies, propose novel or improved methods with increased performance, provide insight into various aspects of quality control, and also introduce some unorthodox positioning methods