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Finite time L_1 Approach for Missile Overload Requirement Analysis in Terminal Guidance

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Chinese Journal of Aeronautics 2009年第4期22卷 413-418页

作者： Ji Denggao,He Fenghua,Yao Yu Control and Simulation Center,Harbin Institute of Technology,Harbin 150080,China Control and Simulation Center Harbin Institute of TechnologyHarbin 150080China

This article analyzes the problem about the missile overload requirement in a homing terminal guidance under various engagement scenarios. An augmented proportional navigation guidance （APNG） model is introduced on the basis of linear kinematics. To analyze the peak-to-peak performance of the terminal guidance system, a new finite time L1 performance measure for a linear time-varying （LTV） continuous system is proposed. Then, according to the idea of the adjoint system, a novel method for computing the L1 norm of a linear continuous system is first derived. Within the finite time L1 framework, the quantitative relation between the guidance loop dynamics and the maximum missile-target maneuver ratio is offered. This relation is expressed in the form of graphs and formulas that can be used to synthesize some of the major subsystem specifications for the missile guidance system. The illustrative examples show that a significant performance improvement is achieved with the proposed guidance loop dynamics.

关键词： finite time Lx-induced norm performance time varying systems missile overload requirement terminal guidance

Antimicrobial activity of silver loaded MnO_2 nanomaterials with different crystal phases against Escherichia coli

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Journal of Environmental Sciences 2016年第3期28卷 112-120页

作者： Lian Wang Hong He Changbin Zhang Li Sun Sijin Liu Shaoxin Wang State Key Joint Laboratory of Environment simulation and Pollution control Research Center for Eco-Environmental SciencesChinese Academy of Sciences

Silver-loaded MnO_2 nanomaterials（Ag/MnO_2）,including Ag/α-MnO_2,Ag/β-MnO_2,Ag/γ-MnO_2and Ag/δ-MnO_2 nanorods,were prepared with hydrothermal and impregnation methods.The bactericidal activities of four types of Ag/MnO_2 nanomaterials against Escherichia coli were investigated and an inactivation mechanism involving Ag~＋ and reactive oxygen species（ROS）was also proposed.The bactericidal activities of Ag/MnO_2 depended on the MnO_2 crystal phase.Among these nanomaterials,Ag/β^-MnO_2 showed the highest bactericidal activity.There was a 6-log decrease in E.coli survival number after treatment with Ag/β^-MnO_2 for120 min.The results of 5,5-dimethyl-l-pyrroline-N-oxide spin-trapping measurements by electron spin resonance indicate OH and O_2^- formation with addition of Ag/β-MnO_2,Ag/γ-MnO_2 or Ag/δ-MnO_2.The strongest peak of OH appeared for Ag/β-MnO_2,while no OH or ·O_2^-signal was found over Ag/α-MnO_2.Through analysis of electron spin resonance（ESR） and Ag＋elution results,it could be deduced that the toxicity of Ag~＋ eluted from Ag/MnO_2 nanomaterials and ROS played the main roles during the bactericidal process.Silver showed the highest dispersion on the surface of β-MnO_2,which promoted ROS formation and the increase of bactericidal activity.Experimental results also indicated that Ag/MnO_2 induced the production of intracellular ROS and disruption of the cell wall and cell membrane.

关键词： Silver MnO_2 Bactericidal activity Escherichia coli ROS

Dual-quaternion-based modeling and control for motion tracking of a tumbling target

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Journal of Systems Engineering and Electronics 2019年第5期30卷 985-994页

作者： PENG Xuan SHI Xiaoping GONG Yupeng Control and Simulation Center Harbin Institute of TechnologyHarbin 150001China Research center of Satellite Technology Harbin Institute of TechnologyHarbin 150001China

This paper investigates the problem of controlling a chasing spacecraft(chaser)to track and rendezvous with an uncontrolled target.Based on the actual situation,the torque-free motion of an axisymmetric prolate rigid body is employed to represent the short-term attitude motion of the tumbling target.By taking advantage of the dual quaternion’s compact and efficient description of the general rigid motion,the coupled and integrated model of the 6-degree-of-freedom(6-DOF)relative motion between the chaser and the tumbling target is derived in the chaser’s body fixed frame after taking full consideration of coordinate transformation.Based on the logarithm of dual quaternion,a sliding mode control(SMC)law based on the exponential reaching law and the continuous relay function is brought forward to address the problem of synchronization control of the 6-DOF relative motion.simulation results illustrate the effectiveness of the proposed method.

关键词： tumbling target dual-quaternion coupled dynamics relative motion

Establishment and Validation for the Theoretical Model of the Vehicle Airbag

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Chinese Journal of Mechanical Engineering 2015年第3期28卷 487-495页

作者： ZHANG Junyuan JIN Yang XIE Lizhe CHEN Chao State Key Laboratory of Automobile simulation and control Jilin University China Automotive Technology & Research center

The current design and optimization of the occupant restraint system（ORS） are based on numerous actual tests and mathematic simulations. These two methods are overly time-consuming and complex for the concept design phase of the ORS, though they＇re quite effective and accurate. Therefore, a fast and directive method of the design and optimization is needed in the concept design phase of the ORS. Since the airbag system is a crucial part of the ORS, in this paper, a theoretical model for the vehicle airbag is established in order to clarify the interaction between occupants and airbags, and further a fast design and optimization method of airbags in the concept design phase is made based on the proposed theoretical model. First, the theoretical expression of the simplified mechanical relationship between the airbag＇s design parameters and the occupant response is developed based on classical mechanics, then the momentum theorem and the ideal gas state equation are adopted to illustrate the relationship between airbag＇s design parameters and occupant response. By using MATLAB software, the iterative algorithm method and discrete variables are applied to the solution of the proposed theoretical model with a random input in a certain scope. And validations by MADYMO software prove the validity and accuracy of this theoretical model in two principal design parameters, the inflated gas mass and vent diameter, within a regular range. This research contributes to a deeper comprehension of the relation between occupants and airbags, further a fast design and optimization method for airbags＇ principal parameters in the concept design phase, and provides the range of the airbag＇s initial design parameters for the subsequent CAE simulations and actual tests.

关键词： occupant restraint systems,airbag,theoretical model,concept design

Kinematics analysis of a novel all-attitude flight simulator

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Science China(Information Sciences) 2010年第2期53卷 236-247页

作者： WANG XiaoChen , ZHAO Hui, MA KeMao, HUO Xin & YAO Yu Control and Simulation Center, Harbin Institute of Technology, Harbin 150080, China Control and Simulation Center Harbin Institute of Technology Harbin China

To overcome the kinematic singularity limitation of simulator, which is unavoidable in a three-axis architecture, an all-attitude flight simulator in a four-axis architecture is proposed. The simulator can always provide 3DOF motion by applying redundant manipulator mechanism. For direct kinematics of the manipulator, a dual-Euler method is adopted to solve the expressions of attitude angles; thus computation singularity of all- attitude angles is overcome. For inverse kinematics of the manipulator, pseudo-inverse gradient projection method is used to obtain optimal velocity solution. Then, based on dynamic control method, optimal position solution is obtained. The proposed inverse kinematics algorithm can achieve desired attitudes, as well as can avoid kinematics singularity and axis angle limits. The simulation results show that the kinematic performance of the four-axis all-attitude flight simulator is superior to that of a three-axis simulator.

关键词： all-attitude flight simulator kinematic singularity direct kinematics inverse kinematics

Optimal car-following control for intelligent vehicles using online road-slope approximation method

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Science China(Information Sciences) 2021年第1期64卷 94-109页

作者： Hongqing CHU Lulu GUO Hong CHEN Bingzhao GAO State Key Laboratory of Automotive simulation and control Jilin University center for Cyber-Physical systems University of Georgia Clean Energy Automotive Engineering center Tongji University

The design of a car-following control system is a multiobjective optimization problem that involves issues in rider safety, ride comfort, and fuel economy. This study proposes a hierarchical design of optimal car-following control where the system is intuitively split into two subsystems with different dynamic properties. Specifically, the high-level subsystem is a linear car-following system with a measurable disturbance of the preceding vehicle’s acceleration, while the low-level subsystem is a nonlinear accelerationtracking system with an unmeasurable road slope. In the design of optimal car-following control, the measurable disturbance of the preceding vehicle’s acceleration is considered from a theoretical perspective, and the unmeasurable road slope is estimated by a novel engineering-oriented approximation method to reduce the influence of driveline oscillation. The performance of the proposed optimal control scheme is evaluated through simulation and real-vehicle experiments, which show that the proposed control algorithm provides a satisfactory road-slope approximation accuracy and that the car-following performance of the proposed optimal control system is better than that of a factory-installed adaptive cruise controller.

关键词： car-following control road-slope approximation hierarchical design linear quadratic regulator intelligent vehicle

A Non-Convex Optimization Approach to Dynamic Coverage Problem of Multi-agent Systems in an Environment with Obstacles

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Journal of Systems Science & Complexity 2020年第2期33卷 426-445页

作者： MA Longbiao HE Fenghua WANG Long LI Changxi YAO Yu Control and Simulation Center Harbin Institute of TechnologyHarbin 150080China

In this paper,a cooperative region reconnaissance problem is investigated where a group of agents are required to fly across and detect events occur in an environment with static obstacles until an effective coverage is achieved.First,the region reconnaissance is formulated as a non-convex optimization problem.A coverage performance index with additional collision and obstacle avoidance constraints is given.Since the optimization index is an implicit function of state variables and cannot be used to compute gradients on state variables directly,an approximate optimization index is selected.Then,a non-convex optimization-based coverage algorithm is proposed to find the optimal reconnaissance location for each agent and guarantee no collisions trajectories among agents and obstacles.Finally,simulation experiments are performed to verify the effectiveness of the proposed approach.

关键词： Dynamic coverage multi-agent systems non-convex optimization obstacles region reconnaissance

Subspace Identification for Closed-Loop Systems With Unknown Deterministic Disturbances

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IEEE/CAA Journal of Automatica Sinica 2023年第12期10卷 2248-2257页

作者： Kuan Li Hao Luo Yuchen Jiang Dejia Tang Hongyan Yang IEEE Shanghai Aerospace control Technology Institute Shanghai 201109China the Control and Simulation Center School of AstronauticsHarbin Institute of TechnologyHarbin 150006China the Faculty of Information Technology Engineering Research Center of Digital CommunityMinistry of EducationBeijing University of TechnologyBeijing 100124China

This paper presents a subspace identification method for closed-loop systems with unknown deterministic disturbances.To deal with the unknown deterministic disturbances,two strategies are implemented to construct the row space that can be used to approximately represent the unknown deterministic disturbances using the trigonometric functions or Bernstein polynomials depending on whether the disturbance frequencies are known.For closed-loop identification,CCF-N4SID is extended to the case with unknown deterministic disturbances using the oblique projection.In addition,a proper Bernstein polynomial order can be determined using the Akaike information criterion(AIC)or the Bayesian information criterion(BIC).Numerical simulation results demonstrate the effectiveness of the proposed identification method for both periodic and aperiodic deterministic disturbances.

关键词： Bernstein polynomial closed-loop system subspace identification unknown deterministic disturbances

Integral-backstepping-based Attitude control for UAH with Immeasurable States

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Integral-backstepping-based Attitude Control for UAH with Im...