Self-aided SINS for spiral-diving human-occupied vehicle in midwater

2021 ◽  
Vol 41 (1) ◽  
pp. 106-115
Author(s):  
Xianjun Liu ◽  
Xixiang Liu ◽  
Hang Shen ◽  
Peijuan Li ◽  
Tongwei Zhang
Keyword(s):  
Error Propagation ◽  
Inertial Measurement Unit ◽  
Design Methodology ◽  
Horizontal Velocity ◽  
Measurement Unit ◽  
Positioning Error ◽  
Pass Filter ◽  
Content Type ◽  
High Pass ◽  
Delay Correction

Purpose Motivated by the problems that the positioning error of strap-down inertial navigation system (SINS) accumulates over time and few sensors are available for midwater navigation, this paper aims to propose a self-aided SINS scheme for the spiral-diving human-occupied vehicle (HOV) based on the characteristics of maneuvering pattern and SINS error propagation. Design/methodology/approach First, the navigation equations of SINS are simultaneously executed twice with the same inertial measurement unit (IMU) data as input to obtain two sets of SINS. Then, to deal with the horizontal velocity provided by one SINS, a delay-correction high-pass filter without phase shift and amplitude attenuation is designed. Finally, the horizontal velocity after processing is used to integrate with other SINS. Findings Simulation results indicate that the horizontal positioning error of the proposed scheme is less than 0.1 m when an HOV executes spiral diving to 7,000 meters under the sea and it is inherently able to estimate significant sensors biases. Originality/value The proposed scheme can provide a precise navigation solution without error growth for spiral-diving HOV on the condition that only IMU is required as a navigation sensor.

Development of low-cost mobile laser scanning for 3D construction indoor mapping by using inertial measurement unit, ultra-wide band and 2D laser scanner

2019 ◽  
Vol 26 (7) ◽  
pp. 1367-1386
Author(s):  
Chao Chen ◽  
Llewellyn Tang ◽  
Craig Matthew Hancock ◽  
Penghe Zhang
Keyword(s):  
Inertial Measurement Unit ◽  
Indoor Environment ◽  
Laser Scanning ◽  
Low Cost ◽  
Laser Scanner ◽  
Wide Band ◽  
Measurement Unit ◽  
Content Type ◽  
Inertial Measurement ◽  
Mls Method

Purpose The purpose of this paper is to introduce the development of an innovative mobile laser scanning (MLS) method for 3D indoor mapping. The generally accepted and used procedure for this type of mapping is usually performed using static terrestrial laser scanning (TLS) which is high-cost and time-consuming. Compared with conventional TLS, the developed method proposes a new idea with advantages of low-cost, high mobility and time saving on the implementation of a 3D indoor mapping. Design/methodology/approach This method integrates a low-cost 2D laser scanner with two indoor positioning techniques – ultra-wide band (UWB) and an inertial measurement unit (IMU), to implement a 3D MLS for reality captures from an experimental indoor environment through developed programming algorithms. In addition, a reference experiment by using conventional TLS was also conducted under the same conditions for scan result comparison to validate the feasibility of the developed method. Findings The findings include: preset UWB system integrated with a low-cost IMU can provide a reliable positioning method for indoor environment; scan results from a portable 2D laser scanner integrated with a motion trajectory from the IMU/UWB positioning approach is able to generate a 3D point cloud based in an indoor environment; and the limitations on hardware, accuracy, automation and the positioning approach are also summarized in this study. Research limitations/implications As the main advantage of the developed method is low-cost, it may limit the automation of the method due to the consideration of the cost control. Robotic carriers and higher-performance 2D laser scanners can be applied to realize panoramic and higher-quality scan results for improvements of the method. Practical implications Moreover, during the practical application, the UWB system can be disturbed by variances of the indoor environment, which can affect the positioning accuracy in practice. More advanced algorithms are also needed to optimize the automatic data processing for reducing errors caused by manual operations. Originality/value The development of this MLS method provides a novel idea that integrates data from heterogeneous systems or sensors to realize a practical aim of indoor mapping, and meanwhile promote the current laser scanning technology to a lower-cost, more flexible, more portable and less time-consuming trend.

Synaptic plasticity of TiO2 nanowire transistor

2020 ◽  
Vol 37 (3) ◽  
pp. 125-130
Author(s):  
Hongxia Qi ◽  
Ying Wu
Keyword(s):  
Synaptic Plasticity ◽  
Stimulus Frequency ◽  
Pulse Interval ◽  
Pass Filter ◽  
Content Type ◽  
High Pass Filter ◽  
Nanowire Transistor ◽  
Promising Application ◽  
Response Current ◽  
High Pass

Purpose The emulation of synapses is essential to neuromorphic computing systems. Despite remarkable progress has been made in the two-terminal device (memristor), three-terminal transistors evoke greater attention because of the controlled conductance between the source and drain. The purpose of this paper is to investigate the synaptic plasticity of the TiO2 nanowire transistor. Design/methodology/approach TiO2 nanowire transistor was assembled by dielectrophoresis, and the synaptic plasticity such as paired-pulse facilitation, learning behaviors and high-pass filter were studied. Findings Facilitation index decreases with the increasing pulse interval. A bigger response current is obtained at the pulses with higher amplitude and smaller intervals, which is similar to the consolidated memory at the deeply and frequently learning. The increased current at the higher stimulus frequency demonstrates a promising application in the high-pass filter. Originality/value TiO2 nanowire transistors possess broad application prospects in the future neural network.

How the Integral Operations in INS Algorithms Overshadow the Contributions of IMU Signal Denoising Using Low-Pass Filters

2013 ◽  
Vol 66 (6) ◽  
pp. 837-858 ◽  
Author(s):  
Yalong Ban ◽  
Quan Zhang ◽  
Xiaoji Niu ◽  
Wenfei Guo ◽  
Hongping Zhang ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Inertial Measurement Unit ◽  
Measurement Unit ◽  
Signal Denoising ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Static Data ◽  
Low Pass ◽  
Low Pass Filters ◽  
Navigation Accuracy

This paper has made a comprehensive investigation of the contribution of inertial measurement unit (IMU) signal denoising in terms of navigation accuracy, through theoretical analysis, simulations and real tests. Analysis shows that the integral step in the inertial navigation system (INS) algorithm is essentially equivalent to a super low-pass filter (LPF), whose filtering strength is related to the integral time of the INS. Therefore the contribution of the IMU denoising filter is almost completely overshadowed by the effect of the integral step for normal navigation cases. The theoretical analysis result was further verified by the simulations with an example of inertial angle estimation and by real tests of INS and GPS/INS systems. Results showed that the IMU signal denoising cannot bring observable improvement to INS or GPS/INS systems. This conclusion is strictly valid in the condition that the equivalent cut-off frequency of the integral step (which equals the reciprocal of the INS working alone time) is lower than the cut-off frequency of the denoising filter, which is the usual case for INS applications (except for some static data processing such as the stationary alignment of INS).

Verification of a special inertial measurement unit using a Quadrotor aircraft

2014 ◽  
Vol 2 (1) ◽  
pp. 40-55 ◽  
Author(s):  
Angel Flores-Abad ◽  
Pu Xie ◽  
Gabriela Martinez-Arredondo ◽  
Ou Ma
Keyword(s):  
Inertial Measurement Unit ◽  
Angular Acceleration ◽  
Flight Test ◽  
Measurement Unit ◽  
Processing Unit ◽  
Dynamics Modeling ◽  
Content Type ◽  
Inertial Measurement ◽  
Quadrotor Aircraft ◽  
Kinematics Modeling

Purpose – Calibration and 6-DOF test of a unique inertial measurement unit (IMU) using a Quadrotor aircraft. The purpose of this paper is to discuss the above issue. Design/methodology/approach – An IMU with the special capability of measuring the angular acceleration was developed and tested. A Quadrotor aircraft is used as 6-DOF test platform. Kinematics modeling of the Quadrotor was used in the determination of the Euler angles, while Dynamics modeling aided in the design the closed loop controller. For safety, the flight test was performed on a 6-DOF constrained reduced-gravity test stand. Findings – The developed IMU is suitable for measuring states and its time derivatives of mini UAVs. Not only that but also a simple control algorithm can be integrated in the same processing unit (a 32 microcontroller in this case). Originality/value – The tested IMU as well as the safety constrained test techniques are unique.

A V-Band Two Pole High-Pass Filter for Frequency Quadrupler Design

2016 ◽  
Vol 6 (1) ◽  
pp. 56
Author(s):  
Maryam Abata ◽  
Mahmoud Mehdi ◽  
Said Mazer ◽  
Moulhime El Bekkali ◽  
Catherine Algani
Keyword(s):  
Pass Filter ◽  
High Pass Filter ◽  
V Band ◽  
High Pass
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