Three-dimensional nonlinear H2/H∞ guidance law based upon approach of solving the state feedback Nash balance point

Based upon the theory of the nonlinear quadric two-person nonzero-sum differential game,the fact that the time-limited mixed H2/H∞ control problem can be turned into the problem of solving the state feedback Nash balance point is mentioned. Upon this,a theorem about the solution of the state feedback control is given,the Lyapunov stabilization of the nonlinear system under this control is proved,too. At the same time,this solution is used to design the nonlinear H2/H∞ guidance law of the relative motion between the missile and the target in three-dimensional(3D) space. By solving two coupled Hamilton-Jacobi partial differential inequalities(HJPDI),a control with more robust stabilities and more robust performances is obtained. With different H∞ performance indexes,the correlative weighting factors of the control are analytically designed. At last,simulations under different robust performance indexes and under different initial conditions and under the cases of intercepting different maneuvering targets are carried out. All results indicate that the designed law is valid.     

Robust H∞ and H2 Static Output Feedback Control of Discrete-time Piecewise Affine Singular Systems with Norm-bounded Uncertainties

This paper is concerned with the problem of designing robust H∞and H2static output feedback controllers for a class of discrete-time piecewise-affine singular systems with norm-bounded time-varying parameters uncertainties. Based on a piecewise singular Lyapunov function combined with S-procedure,Projection lemma and some matrix inequality convexifying techniques,sufficient conditions in terms of linear matrix inequalities are given for the existence of an output-feedback controller for the discrete-time piecewiseaffine singular systems with a prescribed H∞disturbance attenuation level,and the H2norm is smaller than a given positive number. It is shown that the controller gains can be obtained by solving a family of LMIs parameterized by one or two scalar variables. The numerical examples are given to illustrate the effectiveness of the proposed design methods.     

Robust State Feedback H_∞Control for Dynamic Biped Robot Based on T-S Fuzzy Model

T-S fuzzy model was applied to describe nonlinear system and global fuzzy model was expressed by the form of uncertain system.Based on robust state feedback H_∞control strategy,designed a global asymptotic steady fuzzy model.This control system can use the experimental input-output data pairs for the biped robot learning and walking with dynamic balance.It is proved by simulation result that robust state feedback H_∞control method based on T-S fuzzy model can effectively restrain the effect of model uncertainties and external disturbance acting on biped robot.From these works,we showed the satisfactory performance of joint tracking without any chattering.     

汽车主动悬架H2/H∞多目标优化控制

为协调主动悬架各项相互冲突的性能,采用基于H₂/H_∞混合控制进行约束优化,解决半车电液主动悬架系统多目标优化控制问题。选择路面扰动到悬架质量垂直加速度和俯仰角加速的闭环传递函数的H₂范数为平顺性指标,路面扰动到悬架动行程、主动控制力和轮胎动位移的闭环传递函数的H_∞范数为操纵稳定性指标,选择合理的γ₁值,最终求出全状态最优控制律。仿真中假设平整路面上有一个包块,作为路面扰动脉冲输入,将该控制方案与半车被动悬架的时域仿真结果进行对比。结果表明该方案较好地解决了舒适性与操纵稳定性指标之间的矛盾。     

Hybrid H_2/H_∞ force/position control based on neural networks

Ifitisnecessaryforarobottocontactitsoperatingenvironmentwhenitexecutessometasks ,suchasassembling ,polishing ,edgefollowingandcutting ,itrequiresaforcecontrolinordertoachievethebestresult.RaibertandCraigfirstbroughtforwardhybridposition/forcecontrolstrategies .Withthisframework ,therehavebeenmanyscholarswhohaveproposedvariousnewcontrolstrategies ,suchasadaptivecontrol,slidingcontrolandrobustcontrol,etc .Inrecent years,neuralnetworkandfuzzycontrol[1 ,2 ] havebeenextensivelystudiedfortheiruseint…     

弹性飞机的混合H2/H∞最优PID控制器设计

针对弹性飞机强鲁棒性、低阶次、低增益鲁棒控制器的设计问题,以某弹性飞机12阶模型为研究对象,研究了基于弹性飞机降阶模型的混合H2/H∞最优PID控制器的设计。首先基于平衡截断法得到了6阶降阶模型。然后,根据全阶模型和降阶模型的频域降阶误差选取了合适的鲁棒加权函数。之后,给出了系统跟踪误差的H2范数的一种简化计算方法用于计算H2范数优化设计指标。最后使用粒子群优化算法进行了混合H2/H∞最优PID控制器参数的优化得到了最优PID控制器。仿真结果表明,与H∞混合灵敏度控制器相比,混合H2/H∞最优PID控制器阶次更低,并能同时镇定参数和非参数两种不确定性具有更强的鲁棒性;对弹性形变有较好的抑制作用,对刚性模态也取得了很好的控制效果。     

空间飞行器大角度姿态机动混合H2/H∞控制

提出一种基于平方和优化的空间飞行器大角度姿态机动混合H2/H∞控制方法.为适应飞行器大角度姿态机动的要求,采用修正的Rodrigues参数描述卫星的姿态运动,并将飞行器姿态运动学和动力学方程转化为线性参数可变(LPV)系统;为降低设计的保守性,通过引入附加松弛变量,提出一种系统矩阵与Lya-punov矩阵分离的混合H2/H∞性能准则;基于该性能准则,运用Lyapunov方法和平方和优化技术,推导出飞行器大角度姿态机动混合H2/H∞状态反馈控制器存在的充分条件,并将混合H2/H∞控制器设计问题转化为具有平方和约束的参数优化问题.     

Influence of coexisting substances on the photodegradation behaviors of 17α-ethinylestradiol （EE2） in the UV/H2O2 process

The batch photodegradation reactor was used to investigate the influence of the common coexisting substances in wastewater,such as H+,anions (HCO3-,Cl-and NO3-) and organic compounds (methanol and bisphenol A),on the photodegradation behaviors of EE2 in the UV/H2O2 process.The results indicated that the addition of coexisting substances can influence the photodegradation behaviors of EE2 and it also follows the first-order kinetics.The acidic (pH 2-4) and alkaline (pH 10-12) medium benefit the photodegradation of EE2,but the photodegradation rate constant of EE2 keeps almost constant in the pH value of 4-10.The addition of anions,such as HCO3-,Cl-and NO3-,can inhibit the photodegradation of EE2,and the rate constant has a negative linear relationship with the concentration of the anions.However,the reduction degrees vary with the anions kinds,and the inhibition effect of the three anions is in the order of HCO3->NO3->Cl-.Addition of 5 mg/L methanol and bisphenol A can reduce the photodegradation rate constant of EE2by 84.31% and 72%,respectively.By comparison,the retardant effect of methanol is much more evident.In the studied concentrations range,the photodegradation rate constant of EE2 is the unary quadratic function of the organic compounds concentrations.     

LMI Approach to Robust H∞/H2 Controller Design with Regional Poles Constraint of a Pump-Motor System

Whenfacing withthe practical servosystemcon-trol problem,the control systemis often required tomeet many performance indexes which include ti medomain,frequency domainand H∞/H2.Theseindex-es have explicit purpose and appliedsituation.For ex-ample,the H∞normbetween disturbance and outputrepresents the capability of noise-i mmune,the smallerthe H∞normis,the more excellent stiffness the sys-temhas.And the square of H2norm between inputand output is equal to the energy of the systempulserespo…