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Active disturbance rejected predictive functional control for space vehicles with RCS

Journal of Systems Engineering and Electronics 2018年第5期29卷 1022-1035页

作者： TIAN Jiayi zhang shifeng College of Aerospace Science and Engineering National University of Defense Technology

Reaction control system(RCS) is a powerful and efficient actuator for space vehicles attitude control, which is typically characterized as a pulsed unilateral effector only with two states(off/on). Along with inevitable internal uncertainties and external disturbances in practice, this inherent nonlinear character always hinders space vehicles autopilot from pursuing precise tracking performance. Compared to most of pre-existing methodologies that passively suppress the uncertainties and disturbances, a design based on predictive functional control(PFC) and generalized extended state observer(GESO) is firstly proposed for three-axis RCS control system to actively reject that with no requirement for additional fuel consumption. To obtain a high fidelity predictive model on which the performance of PFC greatly depends, the nonlinear coupling multiple-input multiple-output(MIMO) flight dynamics model is parameterized as a state-dependent coefficient form. And based on that, a MIMO PFC algorithm in state space domain for a plant of arbitrary orders is deduced in this *** internal uncertainties and external disturbances are lumped as a total disturbance, which is estimated and cancelled timely to further enhance the robustness. The continuous control command synthesised by above controller-rejector tandem is finally modulated by pulse width pulse frequency modulator(PWPF) to on-off signals to meet RCS requirement. The robustness and feasibility of the proposed design are validated by a series of performance comparison simulations with some prominent methods in the presence of significant perturbations and disturbances, as well as measurement noise.

关键词： reaction control system(RCS) predictive functional control(PFC) generalized extended state observer(GESO) pulse width pulse frequency(PWPF) multiple-input multiple-output(MIMO)

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Optimal aeroassisted symmetric transfer between coplanar elliptical orbits

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Journal of Systems Engineering and Electronics 2013年第2期24卷 261-271页

作者： Jun Fu Hong Cai shifeng zhang College of Aerospace and Material Engineering National University of Defense Technology

The problem of optimal aeroassisted symmetric transfer between elliptical orbits is *** complete trajectory is assumed as consisting of two impulsive velocity changes at the beginning and the end of an interior atmospheric subarc,where the vehicle is controlled via the lift coefficient and *** corresponding dynamic equations are built and bounded controls are *** the purpose of optimization computation,the equations are *** order to minimize the total fuel consumption,the geocentric radius of initial elliptical transfer orbital perigee and controls during atmospheric flight should all be *** is an optimal control problem which involves additional parameter *** solve the problem,a two-level optimization method denoted by ＂genetic algorithm ＋ Gauss pseudospectral method＂ is adopted：the genetic algorithm is used for parameter optimization and the Gauss pseudospectral method is used for optimal control *** flow chart of simulation is *** this basis,the issue of more realistic modeling with two finite-thrust subarcs in the nonatmospheric part of the trajectory is simultaneously *** orbital transfer problem is transformed to three continuous optimal control problems,and the constraints at different times are given,which are respectively solved by using the Gauss pseudospectral *** obtained numerical results indicate that the optimal thrust control is of bangbang *** minimum-fuel trajectory in the atmosphere consists of aeroglide,aerocruise and *** are compared with the results of pure impulsive model,and the conclusions that a significant fuel saving will be achieved by synergetic maneuver are drawn.

关键词： aeroassisted orbital transfer Gauss pseudospectral method optimal control two-level optimization genetic algorithm synergetic maneuver

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Bionic Design and Experimental Validation of a Robotic Airship Inspired by the Physalia physalis

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Journal of Bionic Engineering 2024年第2期21卷 740-753页

作者： Yueneng Yang Lili Chen Zhiyang Liu shifeng zhang College of Aerospace Science and Engineering National University of Defense TechnologyNo.109Deya RoadKaiFu DistrictChangsha410073China Aerospace Technology Institute China Aerodynamics Research and Development CenterMianyang621000China

The robotic airship is one of the most unique and promising green aircraft,however,as a“lighter-than-air aircraft”and“thermal aircraft”,its long-endurance flight has great difficulties in decreasing drag and controlling buoyancy and pressure under thermal *** this work,we reported a robotic airship inspired by the Physalia physalis,imitating its morphology,physiological structure,and biological *** hull is designed by imitating the morphology of the Physalia physalis,and the gasbags including a helium balloon,two ballonets,and a thermoregulation gasbag are designed by imitating the physiological structure and biological behaviors of the pneumatophore,bladder,and gland of the Physalia physalis,*** results show that the bionic airship has an increase of about 40%in lift-to-drag and decreases the pressure in helium balloon by 47.5%under thermal effects,and has better aerodynamic performances and thermoregulation performances than conventional airships.

关键词： Robotic airship Bionic design Aerodynamic performances Thermoregulation Physalia physalis

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Reconfigurable fault-tolerant control for supersonic missiles with actuator failures under actuation redundancy

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Chinese Journal of Aeronautics 2020年第1期33卷 324-338页

作者： Tong LI Zhenyu JIANG Huabo YANG Cheng HU shifeng zhang Unmanned Systems Research Center National Innovation Institute of Defense TechnologyBeijing 100071China College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China

Aircraft undergoing actuator failures into under-actuation have been seldom studied in *** at addressing actuator failures of Total Loss of Effectiveness(TLOE)as well as Partial Loss of Effectiveness(PLOE)resulting in different system actuations,reconfigurable FaultTolerant Control(FTC)is proposed for supersonic wingless missiles under actuation *** under-actuated system of TLOE failure patterns is solved by transformation to cascade systems through a’shape variable’.Meanwhile,actuator TLOE faults of different unknown failure patterns from proper actuation to under-actuation are accommodated by a reconfigurable adaptive law on a multiple-model *** backstepping technique with the Extended State Observer(ESO)method adopted as a basic strategy is applied to an established symmetric coupled missile system with actuator PLOE faults,modeling errors,and external ***,the nonlinear saturation characteristics of actuators are settled by an auxiliary system with the Nussbaum function *** stability of the control system is analyzed and proven through Lyapunov *** simulations are implemented in the presences of aerodynamic uncertainties,gust disturbance,and actuator *** demonstrate the effectiveness of the proposed method with satisfactory tracking performance and actuator fault tolerance capacity.

关键词： Extended State Observer(ESO) Fault-Tolerant Control(FTC) Input saturation Reconfigurable control Under-actuation control

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Characteristics of the double layer associated with terrestrial bow shock by THEMIS observation

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Science China Earth Sciences 2015年第4期58卷 562-572页

作者： LI ShiYou zhang shifeng CAI Hong BAI XiBin XIE QiuHong College of Aerospace Science and Engineering National University of Defense Technology Unit 75171 the Chinese People's Liberation Army Unit 75707 the Chinese People's Liberation Army

This study presents observation and detailed analysis on the double layers （DLs） in the ramp and the foreshock contacting with the foot of the terrestrial bow shock by THEMIS on September 14, 2008 under enhanced dynamic pressure in the solar wind. The results reveal that：（1） The time duration of the double layers is nus 10-40 mV/m. （2） On assuming a propagation speed at the ion mainly 3-8 ms, and their max parallel electric field is miacoustic speed （vs）, their spatial scale is estimated to be 0.3-1.15 km （about 75-200 2D）. （3） The net potential drop of DLs is estimated to be 5-32 V. （4） The DLs in the ramp and the foreshock contacting to the foot of the bow shock is current-carrying as a result of development and evolution of nonlinear phase of instability in the self-consistent current-carrying plasma. The DLs may play an important role in strong turbulence in the foreshock contacting with the foot of the bow shock.

关键词： bow shock double layer electron hole current-carrying plasma

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Observation and analysis of whistler-mode wave and electrostatic solitary waves within density depletion near magnetic reconnection X-line

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Science China(Physics,Mechanics & Astronomy) 2014年第4期57卷 652-658页

作者： LI ShiYou zhang shifeng CAI Hong DENG XiaoHua YANG HuaBo College of Aerospace Science and Engineering National University of Defense Technology Institute of Space Science and Technology Nanchang University

The PWI/WFC data onboard Geotail during one burst time interval when Geotail is skimming a magnetic reconnection diffusion region in the near-Earth magnetotail is carefully *** the whistler-mode wave and the electrostatic solitary wave are found within the region with density depletion on the boundary layer near the magnetic reconnection *** whistler-mode wave is electromagnetic whistler wave propagating quasi-parallel to the ambient field with a small angle between the wave vector and the ambient magnetic *** whistler-mode wave associated with ESWs suggests that enhanced electromagnetic whistler-mode fluctuations can also be generated after the decay of the ESWs,which is different from the 2-D PIC simulation results.

关键词： magnetic reconnection whistler-mode electrostatic solitary waves density depletion

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Design of Sliding Mode Control with Disturbance Observers for Inertial Platform

Design of Sliding Mode Control with Disturbance Observers fo...

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第25届中国控制与决策会议

作者： Yue Hu Yuan Ca shifeng zhang College of Aerospace Science and Engineering National University of Defense and Technology

ISBN: (纸本)9781467355339

In the flight process, the disturbances such as vibrations and frictions affect the stability accuracy of the servo loop of the inertial platform. Besides, the model uncertainties exist due to the couplings of the three subsystem of the inertial platform. This paper presents a sliding mode controller based on a proportional integral （PI） disturbance observer. The state variables and disturbing torque are estimated accurately by the PI observer. Additionally, an integral sliding mode controller is designed. The vibration and stability error are reduced by employing the integral items of the states in designing the sliding mode surface. The simulation results show that the proposed methods can improve the control precision of the servo loop of the platform.

关键词： integral sliding mode control disturbance observer stabilized control of platform

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HIGH-PRECISION STABILIZATION CONTROL FOR A FLOATED INERTIAL PLATFORM

HIGH-PRECISION STABILIZATION CONTROL FOR A FLOATED INERTIAL ...

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第25届中国控制与决策会议

作者： Anliang Li Cai Hong shifeng zhang Cao Yuan College of Aerospace Science and Engineering National University of Defense Technology

ISBN: (纸本)9781467355339

A robust controller based on the extended-state-observer （ESO） is proposed for the high-precision stabilization control of a floated inertial platform. The linear quadratic regulator （LQR） applied to stabilize platform cannot offer satisfied accuracy in the presence of external disturbance. The disturbance models are developed based on the analysis of the platform disturbance characteristic. The ESO is proposed to estimate the system states and the effects of the external disturbance, unmodeled disturbance, parameters uncertainties and sensor noise. The estimated disturbances and the estimated states are used to enhance the robustness of the controller. Simulation results demonstrate the ESO could estimate the states and disturbances accurately and the proposed controller can satisfy the requirements of the high-precision stabilization control of the platform.

关键词： Floated Inertial Platform Disturbance Characteristic Analysis Observers Extended State Observer

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A low power V-band LC VCO with high Q varactor technique in 40 nm CMOS process

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Science China(Information Sciences) 2017年第8期60卷 252-254页

作者： Qian ZHOU Yan HAN shifeng zhang Xiaoxia HAN Lu JIE Ray C.C.CHEUNG Guangtao FENG College of Information Science and Electronic Engineering Zhejiang University Department of Electronic Engineering City University of Hong Kong Semiconductor Manufacturing International Corporation

Dear editor,Demand for higher data transmission rate,particularly in the modern communication systems,has been increasing over the *** example,the IEEE standard 802.15.3c specifies more than2 Gbps data transmission rate,which pushes the frequency band up to 60 *** the transceiver,the working frequency of VCO is in 60 GHz,and that has attracted many people to study it[1,2].However,implementing high speed voltagecontrolled oscillator(VCO)through CMOS technology can be extremely challenging because of the

关键词： VCO A low power V-band LC VCO with high Q varactor technique in 40 nm CMOS process CMOS in high nm LC with

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Biological effect on sugar beet seeds induced by ion implantation

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Chinese Science Bulletin 1999年第14期44卷 1286-1289页

作者： Xianxian Zeng Yanfei Wang shifeng zhang Aligen Ping Bu Jun Liu Huajun Liu Xinjing Inst Technol Urumqi 830008 Peoples R China Xinjiang Acad Agr Sci Inst Econ Crops Urumqi 830000 Peoples R China

Through experimental analysis of peroxidase isozyme in the leaves of sugar beets, it has been verified that the enzyme activity of dry sugar beet seeds is closely connected with the doses of N+ ion implanted, and that low dosage implantation helps to bring about enzyme activation. Meanwhile, new enzyme bands appear, and the growing quantity and trend of sugar beets increase distinctly. The best result can be obtained when the dose of ion implantation is 4x1016N+/cm2 and the number of pulse is 60 times.

关键词： sugar beet N+ ion implantation peroxidase isozyme growing quantity.

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