scholarly journals The Optimal Design of Modulation Angular Rate for MEMS-Based Rotary Semi-SINS

Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 111 ◽  
Author(s):  
Jiayu Zhang ◽  
Jie Li ◽  
Xiaorui Che ◽  
Xi Zhang ◽  
Chenjun Hu ◽  
...  
Keyword(s):  
Rotation Speed ◽  
Inertial Sensor ◽  
Design Method ◽  
Angular Rate ◽  
Sensor Error ◽  
Speed Error ◽  
Rotation Scheme ◽  
Navigation Error ◽  
Roll Axis ◽  
Motion Characteristics

In previous studies, the semi-strapdown inertial navigation system (SSINS), based on microelectromechanical system (MEMS) sensors, had realized cross-range measurement of attitude information of high-spinning projectiles through construction of a “spin reduction” platform of the roll axis. However, further improvement of its measurement accuracy has been difficult, due to the inertial sensor error. In order to enhance the navigational accuracy, a periodically rotating method is utilized to compensate for sensor error, which is called rotation modulation. At present, the rotation scheme, as one of the core technologies, has been studied by a lot of researchers. It is known that the modulation angular rate is the main factor affecting the effectiveness of error modulation. Different from the long-endurance and low-dynamic motion characteristics of ships, however, the short-endurance and high-dynamic characteristics of the high-spinning projectile not only require the modulation angular rate to be as fast as possible but, also, the influence of the rotation speed error caused by rotating mechanism errors cannot be ignored. Combined with the rotation speed error of the rotating mechanism, this paper explored the relationship between modulation angular rate, device error, and the navigation error, and then proposed a design method for optimal modulation angular rate. Experiments were carried out to validate the performance of the method. In addition, the proposed method is applicable for rotation modulation systems with different types of motors as the rotating mechanism.

scholarly journals A Hybrid Framework for Mitigating Heading Drift for a Wearable Pedestrian Navigation System through Adaptive Fusion of Inertial and Magnetic Measurements

2021 ◽  
Vol 11 (4) ◽  
pp. 1902
Author(s):  
Liqiang Zhang ◽  
Yu Liu ◽  
Jinglin Sun
Keyword(s):  
Magnetic Measurements ◽  
Inertial Sensor ◽  
Angular Rate ◽  
Human Motion ◽  
Navigation Systems ◽  
Pedestrian Navigation ◽  
Hybrid Framework ◽  
Outdoor Environments ◽  
Adaptive Fusion ◽  
Indoor And Outdoor Environments

Pedestrian navigation systems could serve as a good supplement for other navigation methods or for extending navigation into areas where other navigation systems are invalid. Due to the accumulation of inertial sensing errors, foot-mounted inertial-sensor-based pedestrian navigation systems (PNSs) suffer from drift, especially heading drift. To mitigate heading drift, considering the complexity of human motion and the environment, we introduce a novel hybrid framework that integrates a foot-state classifier that triggers the zero-velocity update (ZUPT) algorithm, zero-angular-rate update (ZARU) algorithm, and a state lock, a magnetic disturbance detector, a human-motion-classifier-aided adaptive fusion module (AFM) that outputs an adaptive heading error measurement by fusing heuristic and magnetic algorithms rather than simply switching them, and an error-state Kalman filter (ESKF) that estimates the optimal systematic error. The validation datasets include a Vicon loop dataset that spans 324.3 m in a single room for approximately 300 s and challenging walking datasets that cover large indoor and outdoor environments with a total distance of 12.98 km. A total of five different frameworks with different heading drift correction methods, including the proposed framework, were validated on these datasets, which demonstrated that our proposed ZUPT–ZARU–AFM–ESKF-aided PNS outperforms other frameworks and clearly mitigates heading drift.

AN OPTIMIZATION MODEL FOR PRELIMINARY STABILITY AND CONFIGURATION ANALYSES OF SEMI-SUBMERSIBLES

2021 ◽  
Vol 159 (A3) ◽  
Author(s):  
G D Gosain ◽  
R Sharma ◽  
Tae-wan Kim
Keyword(s):  
Optimization Model ◽  
Design Method ◽  
Optimization Techniques ◽  
Design Approach ◽  
Preliminary Design ◽  
Design Environment ◽  
Preliminary Stage ◽  
Steel Weight ◽  
Motion Characteristics ◽  
Almost All

In the modern era of design governed by economics and efficiency, the preliminary design of a semi-submersible is critically important because in an evolutionary design environment new designs evolve from the basic preliminary designs and the basic dimensions and configurations affect almost all the parameters related to the economics and efficiency (e.g. hydrodynamic response, stability, deck load and structural steel weight of the structure, etc.). The present paper is focused on exploring an optimum design method that aims not only at optimum motion characteristics but also optimum stability, manufacturing and operational efficiency. Our proposed method determines the most preferable optimum principal dimensions of a semi-submersible that satisfies the desired requirements for motion performance and stability at the preliminary stage of design. Our proposed design approach interlinks the mathematical design model with the global optimization techniques and this paper presents the preliminary design approach, the mathematical model of optimization. Finally, a real world design example of a semi-submersible is presented to show the applicability and efficiency of the proposed design optimization model at the preliminary stage of design.

A Design Method of Rain Test Device Based on Water Drop Motion Simulation

2013 ◽  
Vol 871 ◽  
pp. 363-368
Author(s):  
Hong Tao Zeng ◽  
Lin Lin Lin ◽  
Cong Feng ◽  
Zhi Huai Xiao
Keyword(s):  
Design Method ◽  
Water Drop ◽  
Electrical Equipment ◽  
Simulation Software ◽  
Test Device ◽  
Rainy Weather ◽  
Drop Motion ◽  
Water Drops ◽  
Motion Characteristics ◽  
Insulation Performance

In order to measure the electric insulation performance of the electrical equipment in rainy weather, its essential to design a rain device to simulate different conditions of rainfall. In this paper, a motion model of raindrop sprayed by the rain device and differential equations describing its motion characteristics are built. Basing on the analysis of water drop motion, a set of simulation software is developed for the selection of rain test device and the analysis of test results. The software can simulate the water drops motion process from nozzle to test equipment, and the simulation results is almost the same with field test, so the simulation software provides the basis for the design of rain test device.

Evaluation of the Torsional VOR in Weightlessness

1993 ◽  
Vol 3 (3) ◽  
pp. 207-218
Author(s):  
Andrew H. Clarke ◽  
Winfried Teiwes ◽  
Hans Scherer
Keyword(s):  
Head Movement ◽  
Angular Rate ◽  
Inertial Force ◽  
Semicircular Canals ◽  
Head Rotation ◽  
Video Data ◽  
Microgravity Conditions ◽  
Oculomotor Response ◽  
Roll Axis ◽  
Integrative Processing

The experimental concept and findings from a recent manned orbital spaceflight are described. Together with ongoing terrestrial and parabolic studies, the present experiment is intended to further our knowledge of the sensory integrative processing of information from the semicircular canals and the otolithic receptors, and to quantify the presumed otolithic adaptation to altered gravito-inertial force environments in a more reliable manner than to date. The experiment included measurement of the basic vestibulo-oculomotor response during active head rotation about each of the three orthogonal axes. Priority was given to the recording of ocular torsion, as elicited by head oscillation about the roll axis, and thus due to the concomitant stimulation of the semicircular canals and otolith receptors. Videooculography was employed for the measurement of eye movements; head movement was measured by three orthogonally arranged angular rate sensors and a triaxial linear accelerometer device. All signals were recorded synchronously on a video/data recorder. Preliminary results indicate alterations in the torsional VOR under zero-g conditions, suggesting an adaptive modification of the torsional VOR gain over the course of the 6-day orbital flight. In addition, the inflight test findings yielded discrepancies between intended and performed head movement indicating impairment in sensorimotor coordination under prolonged microgravity conditions.

Study on the influence of machine tool spindle radial error motion resulted from bearing outer ring tilting assembly

2018 ◽  
Vol 233 (9) ◽  
pp. 3246-3258 ◽  
Author(s):  
Xiaohu Li ◽  
Ke Yan ◽  
Yifa Lv ◽  
Bei Yan ◽  
Lei Dong ◽  
...  
Keyword(s):  
Rotation Speed ◽  
Total Error ◽  
Experimental System ◽  
Outer Ring ◽  
Operation Condition ◽  
Thermal Displacement ◽  
Radial Error ◽  
Spindle Rotation ◽  
Motion Characteristics ◽  
Error Motion

To reveal the spindle radial error motion characteristics in condition of bearing outer ring tilting assembly, mathematical method on spindle radial error motion were analyzed. Then, in real operation condition the natural frequency of the test rig was investigated. Experimental system and methods were designed to test axial thermal displacement, radial error motion and modal characteristic of spindle in condition of bearing outer ring tilting assembly. Results show that axial thermal extension and radial vertical rising of spindle front-end occurs during thermal displacement test. With the same outer spacer nonparallelism, the synchronous error motion and total error motion generally increase with spindle rotation speed, and reach a peak at certain rotation speed.

scholarly journals EFFECT OF DITCHING'S PARAMETERS ON OPERATION QUALITY OF ORCHARD DITCHING-FERTILIZER MACHINE

2021 ◽  
pp. 477-487
Author(s):  
ChunBao Xu ◽  
HongJian Zhang ◽  
ShuangXi Liu ◽  
Chengfu Zhang ◽  
Junlin Mu ◽  
...  
Keyword(s):  
Deflection Angle ◽  
Rotation Speed ◽  
Design Method ◽  
Coverage Rate ◽  
Forward Speed ◽  
Stability Coefficient ◽  
Machine Performance ◽  
The Deflection Angle ◽  
Relative Errors ◽  
The Stability

This study aims to evaluate the effects of different parameter settings on the ditching performance using a ditching-fertilizer. We aimed to improve the performance of ditching-fertilizer machine performance in sustainable agriculture. With Box-Behnken experimental design method, taking forward speed, the rotation speed of the ditching cutter, and the deflection angle of ditching cutter as experimental factors, taking ditching depth stability and soil coverage rate as test indexes, the operation parameters of orchard ditching-fertilizer machine are studied. The regression model between test indexes and experimental factors is established, and the influence of each factor on the experimental indexes is analyzed. The test factors are comprehensively optimized. The results show that when the forward speed is 0.8km/h, the rotation speed of the ditching cutter is 348r/min, and the deflection angle of the ditching cutter is 32°, the ditching effect is the best. At this time, the stability coefficient of the ditching depth is 98.33%, and the soil coverage rate is 81.53%. As for the field test, which measured the stability coefficient of ditching depth, and the average soil cover rate is 96.24%, and 79.14%, respectively, and the relative errors from the optimized value are 2.17%, and 3.02%, respectively.

scholarly journals Performance Criteria for the Identification of Inertial Sensor Error Models

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 1997 ◽  
Author(s):  
Oleg Stepanov ◽  
Andrei Motorin
Keyword(s):  
Inertial Sensors ◽  
Inertial Sensor ◽  
Identification Problem ◽  
Performance Criteria ◽  
Problem Solution ◽  
Error Models ◽  
Sensor Error ◽  
Joint Problem ◽  
Suboptimal Algorithms ◽  
The Bayesian Approach

This paper considers performance criteria for the identification of sensor error models and the procedure for their calculation. These criteria are used to investigate the efficiency of the identification problem solution, depending on the initial data, and to carry out a comparative analysis of various suboptimal algorithms. The calculation procedure is based on an algorithm that solves the joint problem of hypothesis recognition and parameter estimation within the Bayesian approach. A performance analysis of the models traditionally used to describe errors of inertial sensors is given to illustrate the application of the procedure for the calculation of performance criteria.

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