Study on the characteristic of a forced pitching supercavitating vehicle

Pan, Zhan-cheng; Lu, Cewu; Chen, Ying

doi:10.1007/s12204-015-1681-0

Cited by 4 publications

(4 citation statements)

References 5 publications

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“…A frequency division point search method based on minimizing the cost function of the spacecraft and the telescope is used to perform the frequency division operation of the controller to improve the pointing stability of the system. Based on the idea of Pan [29], our frequency division calculation algorithm is as follows:…”

Section: Frequency Division Controlmentioning

confidence: 99%

“…Ren and Sun [27,28] used the finite frequency controller directly focused on the frequency domain of interest and optimized the system performance in a specific frequency band. According to the different requirements of different frequency bands, Pan, Mi, and Lian [29][30][31] designed corresponding controllers and combined the ideological advantages of frequency division control to improve the performance of the control system.…”

Section: Introductionmentioning

confidence: 99%

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Frequency Division Control of Line-of-Sight Tracking for Space Gravitational Wave Detector

Deng

Meng

2022

Sensors

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The space gravitational wave detector uses the inter-satellite laser interferometer to measure a change in distance with ultra-high precision at the picometer level. Its special differential wavefront sensing technology based on laser interference is used to obtain the ultra-high-precision relative attitude between spacecrafts. In order to acquire the measurement, it is necessary to maintain high-precision attitude pointing and alignment for the optical path line-of-sight of the detector. This paper proposes a frequency division control method. More specifically, we chose the telescope attitude control loop frequency division as it is the faster response part, mainly relative to the high-frequency band within the measurement bandwidth. The spacecraft attitude frequency division is mainly in the low-frequency band within the measurement bandwidth. Finally, a high-precision simulation analysis is carried out. The results show that compared with traditional methods, the use of frequency division control design can significantly improve the attitude and pointing stability of the system and provide control support for systems requiring high pointing coordination accuracy, such as space gravity wave detectors.

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Section: Frequency Division Controlmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Frequency Division Control of Line-of-Sight Tracking for Space Gravitational Wave Detector

Deng

Meng

2022

Sensors

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“…where r 1 and r 2 are the core radii of the transmitting fibre and the receiving fibre respectively; NA 1 and NA 2 are their numerical apertures respectively; p is the distance between two optical fibre cores; d is the distance between the optical fibre probe and the reflecting surface; and h is the roughness of the reflecting surface [2,3]. When the reflecting surface is a rough surface and the light is diffusely reflected on the surface of the measured object, it is assumed that the output light intensity of the transmitting fibre is a Gaussian distribution.…”

Section: Forced Modulation Function Modelmentioning

confidence: 99%

Application of Forced Modulation Function Mathematical Model in the Characteristic Research of Reflective Intensity Fibre Sensors

Dai

Wang²,

Cheng

et al. 2021

Applied Mathematics and Nonlinear Sciences

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In order to discuss the application and mode of the forced modulation function in a sensor, the optical fibre emphasis function was established by referring to the geometric method, the tilt factor and the shape factor of the reflecting surface. These were introduced for the first time, and the corresponding mathematical model was established. The method of numerical simulation is systematically studied and multimode optical fibre parameters (including optical fibre of axial spacing, optical fibre core diameter and numerical aperture) are adopted. The reflective surface inclination and shape factors on the RIM–FOS intensity modulation characteristics are studied according to the obtained light quasi-Gaussian distribution model, establishing a general three-intensity modulation function of fibre optic sensor. The results show that the intensity modulation characteristic of specular reflection is obviously better than that of the diffuse reflection surface, and the peak value of the modulation function is five times that of diffuse reflection. The intensity modulation characteristic decreases with increase in the roughness of the reflection surface. The system can not only complete the RIM–FOS characteristic simulation and characteristic testing functions, but can also start-up the test and not be affected by the ambient light interference and power fluctuation of the light source. The test stability is good with high repeatability.

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“…Meanwhile, data-driven online methods that evaluate external performance metrics have attracted considerable research interest [7,8]. Recent studies have advanced the understanding of the thermal characteristics and liquid cooling designs for lithium batteries, providing insights into better thermal management [9]. The state of health assessment of lithium-ion batteries has also evolved with the application of deep Gaussian process regression, which considers heterogeneous features and enhances prediction accuracy [10].…”

Section: Introductionmentioning

confidence: 99%

Airborne Lithium Battery Health Assessment: An Improved Support Vector Machine Algorithm for Imbalanced Sample Sets

Yang,

Ge,

Jin

et al. 2024

Aerospace

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The health assessment of airborne lithium batteries is crucial for flight testing, ensuring the safety and reliability of aircraft power systems. This paper proposes a support vector machine-based algorithm for the health assessment of airborne lithium batteries, featuring a dynamic correction mechanism for the risk loss penalty parameter. The proposed approach systematically adjusts risk loss penalty parameters based on sample misjudgment ratios and incorporates fault identification corrections to meet the safety requirements of the airborne operation. The experimental results demonstrate the stability and reliability of the proposed algorithm in hyperplane deviation suppression as well as significant improvements in fault sample recall rates. When compared with traditional SVM and other baseline methods such as Random Forest and SVR, our method significantly outperformed these algorithms in terms of accuracy, recall rate, and precision rate. This study provides an efficient and reliable method for the health assessment of airborne lithium batteries, with significant application value.

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Study on the characteristic of a forced pitching supercavitating vehicle

Cited by 4 publications

References 5 publications

Frequency Division Control of Line-of-Sight Tracking for Space Gravitational Wave Detector

Frequency Division Control of Line-of-Sight Tracking for Space Gravitational Wave Detector

Application of Forced Modulation Function Mathematical Model in the Characteristic Research of Reflective Intensity Fibre Sensors

Airborne Lithium Battery Health Assessment: An Improved Support Vector Machine Algorithm for Imbalanced Sample Sets

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