A Drift Eliminated Attitude & Position Estimation Algorithm In 3D

Inertial wearable sensors constitute a booming industry. They are self contained, low powered and highly miniaturized. They allow for remote or self monitoring of health-related parameters. When used to obtain 3-D position, velocity and orientation information, research has shown that it is possible to draw conclusion about issues such as fall risk, Parkinson disease and gait assessment. A key issues in extracting information from accelerometers and gyroscopes is the fusion of their noisy data to allow accurate assessment of the disease. This, so far, is an unsolved problem. Typically, a Kalman filter or its nonlinear, non-Gaussian version are implemented for estimating attitude â?? which in turn is critical for position estimation. However, sampling rates and large state vectors required make them unacceptable for the limited-capacity batteries of low-cost wearable sensors. The low-computation cost complementary filter has recently been re-emerging as the algorithm for attitude estimation. We employ it with a heuristic drift elimination method that is shown to remove, almost entirely, the drift caused by the gyroscope and hence generate a fairly accurate attitude and drift-eliminated position estimate. Inertial sensor data is obtained from the 10-axis SP-10C sensor, attached to a wearable insole that is inserted in the shoe. Data is obtained from walking in a structured indoor environment in Votey Hall

Design of a flight director/configuration management system for piloted STOL approaches

The design and characteristics of a flight director for V/STOL aircraft are discussed. A configuration management system for piloted STOL approaches is described. The individual components of the overall system designed to reduce pilot workload to an acceptable level during curved, decelerating, and descending STOL approaches are defined. The application of the system to augmentor wing aircraft is analyzed. System performance checks and piloted evaluations were conducted on a flight simulator and the results are summarized

Space Shuttle flying qualities criteria assessment. Phase 5: Data acquistion and analysis

The development of flying qualities experiments (OFQ) as a part of the Orbiter Experiments Program (OEX) was continued. The data base was extended to use the ground based cinetheodolite measurements of orbiter approach and landing. Onboard the cinetheodolite data were analyzed from flights STS 2 through 7 to identify the effective augmented vehicle dynamics, the control strategy employed by the pilot during preflare, shallow glide, and final flare segments of the landing, and the key approach and touchdown performance measures. A plan for an OFQ flying qualities data archive and processing is presented

Advanced Transport Operating System (ATOPS) Flight Management/Flight Controls (FM/FC) software description

The flight software developed for the Flight Management/Flight Controls (FM/FC) MicroVAX computer used on the Transport Systems Research Vehicle for Advanced Transport Operating Systems (ATOPS) research is described. The FM/FC software computes navigation position estimates, guidance commands, and those commands issued to the control surfaces to direct the aircraft in flight. Various modes of flight are provided for, ranging from computer assisted manual modes to fully automatic modes including automatic landing. A high-level system overview as well as a description of each software module comprising the system is provided. Digital systems diagrams are included for each major flight control component and selected flight management functions

Data-Driven Meets Navigation: Concepts, Models, and Experimental Validation

The purpose of navigation is to determine the position, velocity, and orientation of manned and autonomous platforms, humans, and animals. Obtaining accurate navigation commonly requires fusion between several sensors, such as inertial sensors and global navigation satellite systems, in a model-based, nonlinear estimation framework. Recently, data-driven approaches applied in various fields show state-of-the-art performance, compared to model-based methods. In this paper we review multidisciplinary, data-driven based navigation algorithms developed and experimentally proven at the Autonomous Navigation and Sensor Fusion Lab (ANSFL) including algorithms suitable for human and animal applications, varied autonomous platforms, and multi-purpose navigation and fusion approachesComment: 22 pages, 13 figure

Sensors Utilisation and Data Collection of Underground Mining

This study reviews IMU significance and performance for underground mine drone localisation. This research has designed a Kalman filter which extracts reliable information from raw data. Kalman filter for INS combines different measurements considering estimated errors to produce a trajectory including time, position and attitude. To evaluate the feasibility of the proposed method, a prototype has been designed and evaluated. Experimental results indicate that the designed Kalman filter estimates the internal states of a system

Sensitivity Analyses of Optimized Attitude Estimators Using Sensor Fusion Solutions for Low-Cost MEMS Configurations

Since the 1990’s, there has been increased focus on creating navigation systems for small unmanned systems, particularly small unmanned aerial systems (SUAS). Due to size, weight, and cost restrictions, compared to larger more costly manned systems, navigation systems for SUAS have evolved to be quite different from the proven systems of the past. Today, there are many solutions for the problem of navigation for SUAS. The problem has now become choosing the most fitting navigation solution for a given application/mission. This is particularly true for evaluating solutions that are fundamentally different. This research analyses the performance and sensitivity of four sensor fusion solutions for attitude estimation under multiple simulated flight conditions. There are three different hardware configurations between the four estimators. For this reason, each estimator is tuned to be experimentally optimal, as to provide a fair comparison between different estimators. With each estimator tuned to its highest performance, the estimators are compared based on their sensitivity to tuning error, sensor bias, and estimator initialization error. Finally the estimators\u27 accuracy performances are directly compared. This thesis also provides methods to tune different configuration estimators to their individual best performances. These methods show that choosing tuning parameters based on sensor noise covariance, as is typically done in research, does not produce optimal performance for all estimator formulations. After comparing multiple sensitivity and performance properties of the estimators, observations are provided regarding the efficacy of the analyses, including the applicability of the metrics used to determine performance. Some metrics where shown to be misleading for particular estimators or analyses. Ultimately, guidance is given for choosing performance metrics capable of comparing different solutions

Decentralized Control of Electromagnetic ChipSat Swarm Formations

Small satellite formation missions offer new options for space exploration and scientific experiments. Groups of satellites flying within short relative distances allow various important applications, such as spatially distributed instruments for atmospheric sampling or remote sensing systems. The ability to independently control the relative motion of each satellite is crucial to establish a swarm formation, using a large number of satellites moving along bounded relative trajectories. This type of mission poses several constraints on mass, size, and energy consumption; therefore, an autonomous and selfsufficient approach is necessary to assure relative motion control. A novel concept of miniaturized satellites, referred to as ChipSats, consists of a single printed circuit board which can be equipped with different sets of microelectronic components including power and communication systems, a variety of sensors, and a microcontroller. This study considers a swarm of ChipSats equipped with magnetorquers, operating at extremely short relative distances, and using the electromagnetic interaction force for relative motion and attitude control, assuming the absolute position and relative state of each unit is known. Despite the limitations imposed by using magnetorquers as the sole actuators onboard, the dipole interaction between drifting satellites can be used to achieve bounded relative trajectories, and to establish and maintain a compact swarm. Following a decentralized approach, the ChipSats are periodically linked in interchangeable pairs in order to apply the Lyapunov-based control algorithm and prevent relative drift between all satellites in the swarm. The magnetic dipole moments are used for angular velocity damping when orbit control is not required, and a repulsive collision avoidance electromagnetic control force is applied when two ChipSats are within dangerously close proximity to each other. The performance assessment is conducted through Monte Carlo simulations using MATLAB, by analyzing operational parameters and the effect of initial conditions after deployment.Formações de pequenos satélites oferecem novas opções para exploração espacial e experiências científicas. Grupos de satélites, operando a curtas distâncias relativas, possibilitam importantes aplicações tais como instrumentação espacialmente distribuída para amostragem atmosférica ou sistemas de sensoriamento remoto. A capacidade de controlar de forma independente o movimento de cada satélite é crucial para establecer uma formação em enxame, utilizando um grande número de satélites movendo-se ao longo de trajetórias relativas limitadas. Este tipo de missão impõe várias restrições ao nível do consumo de energia, da massa e do tamanho dos satélites, consequentemente, é necessária uma abordagem autónoma e auto-sustentável para assegurar o controlo das trajetórias relativas. Um novo conceito de satélite miniatura, denominado ChipSat, consiste de uma única placa de circuito impresso que pode ser equipada com diferentes conjuntos de componentes microelectrónicos. Este estudo considera um enxame de ChipSats equipados com magnetorquers, operando a distâncias relativas extremamente reduzidas, e usando a força de interação eletromagnética para controlo do movimento relativo e orientação dos satélites, assumindo que a posição absoluta e relativa de cada unidade é conhecida. Apesar das limitações impostas por usar os magnetorquers como únicos atuadores a bordo, a interação magnética dipolar pode ser usada para limitar trajetórias relativas e establecer um enxame compacto. Seguindo uma abordagem descentralizada, os ChipSats são periodicamente ligados em pares intermutáveis de modo a aplicar o algoritmo de control baseado no teorema de Lyapunov, impedindo o aumento da distância relativa entre todos os satélites no enxame. O momento magnético dipolar é usado para amortecimento da velocidade angular quando o control orbital não é necessário, e uma força eletromagnética repulsiva é usada para controlo de colisão quando dois ChipSats estão perigosamente próximos. A análise de performance é feita através de simulações Monte Carlo no MATLAB, estudando os parâmetros operacionais e o efeito das condições iniciais após o lançamento