scholarly journals A Global Interconnected Observer for Attitude and Gyro Bias Estimation with Vector Measurements

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6514
Author(s):  
Huijuan Guo ◽  
Huiying Liu ◽  
Xiaoxiang Hu ◽  
Yan Zhou
Keyword(s):  
Estimation Accuracy ◽  
Time Varying ◽  
Bias Estimation ◽  
Bounded Noise ◽  
Estimation Errors ◽  
Vector Sensors ◽  
Error Dynamics ◽  
High Level ◽  
Gyro Bias ◽  
Transient And Steady State

This paper proposes a novel interconnected observer to get good estimates of attitude and gyro bias from high-noise vector measurements. The observer is derived based on the theory of nonlinear and linear cascade systems, and its error dynamics have the properties of global exponential stability and robustness to bounded noise. These properties ensure the convergence and boundedness of the attitude and gyro bias estimation errors. To obtain higher estimation accuracy, an approach to calculate time-varying gains for the proposed auxiliary observer is designed under the premise of considering noise terms in the rate gyro and vector sensors. The simulation results show that when the vector sensors’ outputs contain high-level noise, the proposed observer with time-varying gains yields better performance in both the transient and steady-state phases.

scholarly journals DOA and Polarization Parameters Estimation by Exploiting Canonical Polyadic Decomposition of Tensors

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Long Liu ◽  
Ling Wang ◽  
Jian Xie ◽  
Zhaolin Zhang
Keyword(s):  
Gaussian Noise ◽  
Additive White Gaussian Noise ◽  
Polarization State ◽  
Parameters Estimation ◽  
Mean Square ◽  
Estimation Errors ◽  
Vector Sensors ◽  
Canonical Polyadic Decomposition ◽  
Parameters Of Signals ◽  
High Level

A new algorithm to estimate the direction of arrival (DOA) and polarization parameters of signals impinging on an array with electromagnetic (EM) vector-sensors is presented by exploiting the canonical polyadic decomposition (CPD) of tensors. In addition to spatial and temporal diversities, further information from the polarization domain is considered and used in this paper. Estimation errors of these parameters are evaluated by the Cramér-Rao lower bound (CRB) benchmark, in the presence of additive white Gaussian noise (AWGN). The superiority of the proposed algorithm is shown by comparing with the derivative algorithms of MUSIC and ESPRIT. In the proposed algorithm, the parameters can be estimated by virtue of the diversities of the spatial and polarization belonging to the factor matrices, rather than the conventional subspace which is the foundation of MUSIC and ESPRIT. Additionally, the classical CPD algorithm based on Alternating Least Squares (ALS) is introduced to verify the efficacy of the proposed CPD algorithm. Results demonstrate that when the number of snapshots is greater than 50, the proposed algorithm requires a smaller number of snapshots to achieve a high level of performance, compared against the subspace-based algorithms and the ALS-based algorithm. Furthermore, in the matter of the array with a small number of sensors, the discovered advantage concerning the Root Mean Square Error (RMSE) in estimating the DOA and the polarization state of the signal is noteworthy.

scholarly journals Interpolated-DFT-Based Fast and Accurate Amplitude and Phase Estimation for the Control of Power

2016 ◽  
Vol 23 (1) ◽  
pp. 13-26 ◽  
Author(s):  
Józef Borkowski ◽  
Dariusz Kania
Keyword(s):  
Estimation Accuracy ◽  
Estimation Errors ◽  
Renewable Energy Systems ◽  
Factors Affecting ◽  
Slow Decay ◽  
Signal Parameters ◽  
Dsp System ◽  
High Level ◽  
The Impact

AbstractQuality of energy produced in renewable energy systems has to be at the high level specified by respective standards and directives. One of the most important factors affecting quality is the estimation accuracy of grid signal parameters. This paper presents a method of a very fast and accurate amplitude and phase grid signal estimation using the Fast Fourier Transform procedure and maximum decay side-lobes windows. The most important features of the method are elimination of the impact associated with the conjugate’s component on the results and its straightforward implementation. Moreover, the measurement time is very short ‒ even far less than one period of the grid signal. The influence of harmonics on the results is reduced by using a bandpass pre-filter. Even using a 40 dB FIR pre-filter for the grid signal with THD ≈ 38%, SNR ≈ 53 dB and a 20‒30% slow decay exponential drift the maximum estimation errors in a real-time DSP system for 512 samples are approximately 1% for the amplitude and approximately 8.5・10‒2rad for the phase, respectively. The errors are smaller by several orders of magnitude with using more accurate pre-filters.

Attitude and gyro bias estimation for a VTOL UAV

2006 ◽  
Vol 14 (12) ◽  
pp. 1511-1520 ◽  
Author(s):  
Najib Metni ◽  
Jean-Michel Pflimlin ◽  
Tarek Hamel ◽  
Philippe Souères
Keyword(s):  
Bias Estimation ◽  
Vtol Uav ◽  
Gyro Bias

scholarly journals Experimental Comparison between Event and Global Shutter Cameras

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1137
Author(s):  
Ondřej Holešovský ◽  
Radoslav Škoviera ◽  
Václav Hlaváč ◽  
Roman Vítek
Keyword(s):  
High Speed ◽  
Ground Truth ◽  
Motion Blur ◽  
Position Estimation ◽  
Estimation Accuracy ◽  
Experimental Comparison ◽  
Estimation Errors ◽  
Detection Rates ◽  
Ballistic Experiment ◽  
Event Camera

We compare event-cameras with fast (global shutter) frame-cameras experimentally, asking: “What is the application domain, in which an event-camera surpasses a fast frame-camera?” Surprisingly, finding the answer has been difficult. Our methodology was to test event- and frame-cameras on generic computer vision tasks where event-camera advantages should manifest. We used two methods: (1) a controlled, cheap, and easily reproducible experiment (observing a marker on a rotating disk at varying speeds); (2) selecting one challenging practical ballistic experiment (observing a flying bullet having a ground truth provided by an ultra-high-speed expensive frame-camera). The experimental results include sampling/detection rates and position estimation errors as functions of illuminance and motion speed; and the minimum pixel latency of two commercial state-of-the-art event-cameras (ATIS, DVS240). Event-cameras respond more slowly to positive than to negative large and sudden contrast changes. They outperformed a frame-camera in bandwidth efficiency in all our experiments. Both camera types provide comparable position estimation accuracy. The better event-camera was limited by pixel latency when tracking small objects, resulting in motion blur effects. Sensor bandwidth limited the event-camera in object recognition. However, future generations of event-cameras might alleviate bandwidth limitations.

Observer-Based Fault Diagnosis of Satellite Systems Subject to Time-Varying Thruster Faults

2006 ◽  
Vol 129 (3) ◽  
pp. 352-356 ◽  
Author(s):  
Wen Chen ◽  
Mehrdad Saif
Keyword(s):  
Fault Diagnosis ◽  
Estimation Error ◽  
Fault Estimation ◽  
Time Varying ◽  
Satellite Systems ◽  
Adaptive Observers ◽  
Error Dynamics ◽  
The Stability ◽  
Estimation Of Time ◽  
Identification Strategy

This paper presents a novel fault diagnosis approach in satellite systems for identifying time-varying thruster faults. To overcome the difficulty in identifying time-varying thruster faults by adaptive observers, an iterative learning observer (ILO) is designed to achieve estimation of time-varying faults. The proposed ILO-based fault-identification strategy uses a learning mechanism to perform fault estimation instead of using integrators that are commonly used in classical adaptive observers. The stability of estimation-error dynamics is established and proved. An illustrative example clearly shows that time-varying thruster faults can be accurately identified.

scholarly journals Dynamic Beam Hopping Time Slots Allocation Based on Genetic Algorithm of Satellite Communication under Time-Varying Rain Attenuation

Electronics ◽  
2021 ◽  
Vol 10 (23) ◽  
pp. 2909
Author(s):  
Chen Zhang ◽  
Jiangtao Yang ◽  
Yong Zhang ◽  
Ziwei Liu ◽  
Gengxin Zhang
Keyword(s):  
Genetic Algorithm ◽  
Resource Allocation ◽  
Satellite Communication ◽  
Rain Attenuation ◽  
Time Varying ◽  
Dynamic Allocation ◽  
Satellite Systems ◽  
Flexible Resource ◽  
Conventional Methods ◽  
High Level

Beam hopping technology is considered to provide a high level of flexible resource allocation to manage uneven traffic requests in multi-beam high throughput satellite systems. Conventional beam hopping resource allocation methods assume constant rainfall attenuation. Different from conventional methods, by employing genetic algorithm this paper studies dynamic beam hopping time slots allocation under the effect of time-varying rain attenuation. Firstly, a beam hopping system model as well as rain attenuation time series based on Dirac lognormal distribution are provided. On this basis, the dynamic allocation method by employing genetic algorithm is proposed to obtain both quantity and arrangement of time slots allocated for each beam. Simulation results show that, compared with conventional methods, the proposed algorithm can dynamically adjust time slots allocation to meet the non-uniform traffic requirements of each beam under the effect of time-varying rain attenuation and effectively improve system performance.

scholarly journals INS/GPS for High-Dynamic UAV-Based Applications

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Junchuan Zhou ◽  
Stefan Knedlik ◽  
Otmar Loffeld
Keyword(s):  
Carrier Phase ◽  
Velocity Estimation ◽  
Estimation Accuracy ◽  
Processing Load ◽  
Estimation Errors ◽  
Integration Interval ◽  
Sequential Processing ◽  
Large Velocity ◽  
Different Types ◽  
High Dynamic

The carrier-phase-derived delta pseudorange measurements are often used for velocity determination. However, it is a type of integrated measurements with errors strongly related to pseudorange errors at the start and end of the integration interval. Conventional methods circumvent these errors with approximations, which may lead to large velocity estimation errors in high-dynamic applications. In this paper, we employ the extra states to “remember” the pseudorange errors at the start point of the integration interval. Sequential processing is employed for reducing the processing load. Simulations are performed based on a field-collected UAV trajectory. Numerical results show that the correct handling of errors involved in the delta pseudorange measurements is critical for high-dynamic applications. Besides, sequential processing can update different types of measurements without degrading the system estimation accuracy, if certain conditions are met.

Analytical Model for High–Level Area Estimation of FPGA Design

2016 ◽  
Vol 7 (2) ◽  
pp. 35-44
Author(s):  
Rachna Singh ◽  
Arvind Rajawat
Keyword(s):  
Early Stage ◽  
Estimation Error ◽  
Research Work ◽  
Performance Estimation ◽  
Estimation Accuracy ◽  
Accurate Estimation ◽  
Fpga Design ◽  
Estimation Model ◽  
Area Estimation ◽  
High Level

FPGAs have been used as a target platform because they have increasingly interesting in system design and due to the rapid technological progress ever larger devices are commercially affordable. These trends make FPGAs an alternative in application areas where extensive data processing plays an important role. Consequently, the desire emerges for early performance estimation in order to quantify the FPGA approach. A mathematical model has been presented that estimates the maximum number of LUTs consumed by the hardware synthesized for different FPGAs using LLVM.. The motivation behind this research work is to design an area modeling approach for FPGA based implementation at an early stage of design. The equation based area estimation model permits immediate and accurate estimation of resources. Two important criteria used to judge the quality of the results were estimation accuracy and runtime. Experimental results show that estimation error is in the range of 1.33% to 7.26% for Spartan 3E, 1.6% to 5.63% for Virtex-2pro and 2.3% to 6.02% for Virtex-5.

scholarly journals Cascaded Kalman Filtering-Based Attitude and Gyro Bias Estimation With Efficient Compensation of External Accelerations

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 50022-50035 ◽  
Author(s):  
Muhammad Azeem Javed ◽  
Muhammad Tahir ◽  
Khurram Ali
Keyword(s):  
Kalman Filtering ◽  
Bias Estimation ◽  
Gyro Bias

scholarly journals Finite-TimeH∞Filtering for Linear Continuous Time-Varying Systems with Uncertain Observations

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Huihong Zhao ◽  
Chenghui Zhang
Keyword(s):  
Quadratic Form ◽  
Continuous Time ◽  
Finite Time ◽  
Krein Space ◽  
State Space Model ◽  
Time Varying ◽  
Bounded Noise ◽  
Time Varying Systems ◽  
Kreĭn Space ◽  
Filtering Problem

This paper is concerned with the finite-timeH∞filtering problem for linear continuous time-varying systems with uncertain observations andℒ2-norm bounded noise. The design of finite-timeH∞filter is equivalent to the problem that a certain indefinite quadratic form has a minimum and the filter is such that the minimum is positive. The quadratic form is related to a Krein state-space model according to the Krein space linear estimation theory. By using the projection theory in Krein space, the finite-timeH∞filtering problem is solved. A numerical example is given to illustrate the performance of theH∞filter.

Sign in / Sign up

Export Citation Format

Share Document