Zhiguang Zhang, Caisheng Wei, Guanhua Huang, Zeyang Yin^*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.33, No.3, pp. 1-1, 2025, DOI:10.32604/icces.2025.010967

Abstract An optimal predictive control method for spacecraft rendezvous based on Koopman operator is proposed for the the libration point rendezvous problem of Earth-moon system. Firstly, the relative motion dynamics model between the chaser and the target spacecraft in the Earth-moon system is established. Secondly, considering the influence of nonlinearity on spacecraft rendezvous control, a global linearization method of nonlinear rendezvous system driven by Koopman operator is proposed. In this method, the Koopman linearization operator is approximated by the extended dynamic mode decomposition (EDMD) method on the finite dimension. Subsequently, based on the linearization model of… More >

Wenjuan Zhang¹, Menglin Xu², Yujuan Feng³, Zhixiong Mao^4,*, Zengyin Yan⁵

International Journal of Mental Health Promotion, Vol.26, No.8, pp. 611-622, 2024, DOI:10.32604/ijmhp.2024.052730 - 30 August 2024

Abstract Background: Exercise procrastination is prevalent among college students, causing decline in physical fitness. It is imperative to investigate the mechanism affecting college students’ physical activity behaviors. This study was aimed at investigating the effect of procrastination on college students’ physical exercise behavior, and the chain mediation effects of exercise commitment and action control (AC), to provide a theoretical basis for interventions targeting physical exercise behavior among college students. Methods: A questionnaire survey was conducted using convenience sampling. The General Procrastination Scale, Exercise Commitment Scale, Action Control Scale, and Physical Activity Rating Scale-3 questionnaires were used.… More >

N. Kanagaraj^*, Mohammed Al-Ansi

Computer Systems Science and Engineering, Vol.45, No.1, pp. 769-784, 2023, DOI:10.32604/csse.2023.029457 - 16 August 2022

Abstract In this research, a modified fractional order proportional integral derivate (FOPID) control method is proposed for the photovoltaic (PV) and thermoelectric generator (TEG) combined hybrid renewable energy system. The faster tracking and steady-state output are aimed at the suggested maximum power point tracking (MPPT) control technique. The derivative order number (µ) value in the improved FOPID (also known as PI^λD^µ) control structure will be dynamically updated utilizing the value of change in PV array voltage output. During the transient, the value of µ is changeable; it’s one at the start and after reaching the maximum power… More >

Kai Liu^{1, 2}, Zheng Hou^{2, *}, Zhiyong She², Jian Guo²

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.1, pp. 131-148, 2020, DOI:10.32604/cmes.2020.08124 - 01 January 2020

Abstract This paper studies the reentry attitude tracking control problem for hypersonic vehicles (HSV) equipped with reaction control systems (RCS) and aerodynamic surfaces. The attitude dynamical model of the hypersonic vehicles is established, and the simplified longitudinal and lateral dynamic models are obtained, respectively. Then, the compound control allocation strategy is provided and the model predictive controller is designed for the pitch channel. Furthermore, considering the complicated jet interaction effect of HSV during RCS is working, an improved model predictive control approach is presented by introducing the online parameter estimation of the jet interaction coefficient for More >