Robust Control Design of Wheeled Inverted Pendulum Assistant Robot

This paper examines the design concept and mobile control strategy of the human assistant robot I-PENTAR(inverted pendulum type assistant robot). The motion equation is derived considering the non-holonomic constraint of the twowheeled mobile robot. Different optimal control approaches are applied to a linearized model of I-PENTAR. These include linear quadratic regulator(LQR), linear quadratic Gaussian control(LQG), H_2 control and H_∞ control. Simulation is performed for all the approaches yielding good performance results.

Quadcopter UAV Modeling and Automatic Flight Control Design

The mathematical model of quadcopter-unmanned aerial vehicle(UAV)is derived by using two approaches:One is the Newton-Euler approach which is formulated using classical mechanics;and other is the Euler-Lagrange approach which describes the model in terms of kinetic(translational and rotational)and potential energy.The proposed quadcopter′s non-linear model is incorporated with aero-dynamical forces generated by air resistance,which helps aircraft to exhibits more realistic behavior while hovering.Based on the obtained model,the suitable control strategy is developed,under which two effective flight control systems are developed.Each control system is created by cascading the proportional-derivative(PD)and T-S fuzzy controllers that are equipped with six and twelve feedback signals individually respectively to ensure better tracking,stabilization,and response.Both proposed flight control designs are then implemented with the quadcopter model respectively and multitudinous simulations are conducted using MATLAB/Simulink to analyze the tracking performance of the quadcopter model at various reference inputs and trajectories.

Integrated Fuzzy Robust Controller for Flight Control Design

μ-synthesis is a practical design approach and has been applied successfully to achieve a nominal and robust performance objectives. However, this design method suffers from the complexity of its practical implementation and high computational demand due to its high order dynamics. To overcome this problem, the interaction between fuzzy logic control which is a part of intelligence control theory and p-synthesis controller is carried out. This is called integrated fuzzy robust controller in this paper. It is obtained by coupling fuzzy pd with p-synthesis controller through the outer loop. Using this design strategy, we can keep the system performance and robustness even a high order p-synthesis controller is reduced into second order model. In order to test the effectiveness of this design method, the linear simulation results for a launch vehicle＇s attitude control motion are presented at the end of this paper.

Research on Mechanisms of Steam Breakthrough and Profile Control Design for Steam Soaking Well

Scaled physical model tests for steam breakthrough were conducted based on the analysis of mechanisms and influence factors of steam breakthrough. Physical simulation results showed that at the initial steam breakthrough, preferential flow channels were formed in narrow sand packs and most residual oil left in these channels was immobile. This shortened the steam breakthrough time of follow-up steam flooding and decreased the increment of oil recovery efficiency. Steam breakthrough occurred easily for a smaller producer-injector spacing, and a bigger difference in physical properties between fluids and rock. Steam breakthrough is more likely to occur at a larger formation permeability （k）, greater steam displacement velocity （u） and smaller producer-injector spacing （L）. Steam breakthrough time is a function of the parameter group （uk/L）, i.e. tb=3.2151 （uk/L）^-0.5142. A non piston-like displacement model was built based on steam breakthrough observation for a steam stimulated well in the Jinglou Oilfield, Henan Oilfield Company. The steam volume swept in different directions could be obtained from inter-well permeability capacity and breakthrough angle, and the steam swept pore volume （SSPV） was also determined. Numerical simulation showed that steam sweep efficiency reached its peak value when a slug of profile control agent （slug size 10%-15% SSPV） was set at one half of the inter-well spacing. Field test with 12.5% SSPV of profile control agents in the Jinglou Oilfield achieved success in sealing breakthrough channels and good production performance of adjacent producers.

Cumulative logit model in the analysis of endometrial cancer under a matched pair case-control design

Background: Binary as well as polytomous logistic models are widely used for estimating odds ratios when the exposure of prime interest assumes unordered multiple levels under matched pairs case-control design. In our previous studies, we have shown that the use of a polytomous logistic model for estimating cumulative odds ratios when the outcome (response) variable is ordinal (in addition to being polytomous) under matched pairs case-control design. The cumulative odds ratios were estimated based on separate fitting of the model at each of the cutpoint level as compared to less than equal to that level. In this paper we propose an alternative method of estimating the cumulative odds ratios and reanalyze the Los Angeles Endometrial Cancer data in the context of dose levels of conjugated oestrogen exposure and development of endometrial cancer under the matched pair case-control design. Methods: In the present study, the cumulative logit model is fitted using a single multinomial logit model for the data. For this, the full maximum likelihood estimation procedure is adopted. A test for equality of the cumulative odds ratios across the exposure levels is proposed. Results: The analysis revealed that there is a strong evidence of risk for developing endometrial cancer due to oestrogen exposure above each of the three dose level as compared to less than equal to that level. The estimated values at the three cutpoint levels were found to be 6.17, 3.60 and 5.16 respectively. Conclusions: The odds of developing endometrial cancer are very high for the users of any amount of oestrogen, even if it is the least dose, as compared to the non-users.

H2 and H∞-Feedback Control Design for Nonlinear Gene Networks via Successive Galerkin’s Approximation

This paper presents a design method of H2 and H∞-feedback control loop for nonlinear smooth gene networks that are in control affine form. Formulaic solution methodology for solving the nonlinear partial differential equations, namely the Hamilton-Jacobi-Bellman and Hamilton-Jacobi-Isaacs equations through successive Galerkin’s approximation is implemented and the results are compared. Throughout the implementation, there were several caveats that need to be further resolved for practical applications in general cases. Such issues and the clarification of causes are mathematically established and reviewed.

双十字路口交通灯控制Stateflow和App Designer仿真

为培养学生能够独立从事自动化相关领域的工程设计、应用研究,解决自动化领域复杂工程实施过程中遇到的关键技术问题,以双十字路口交通灯为研究对象,为计算机辅助建模与仿真类课程设计了一个综合性教学案例。教学案例主要内容为双十字路口Simulink/Stateflow建模与基于Matlab App Designer的交通灯控制可视化仿真。通过此教学案例的实施,明显提高了学生对Matlab的综合应用和工程设计能力,并为后续课程“单片机原理及应用”和“电气控制和PLC”作铺垫。

基于Cast Designer的壳体铸件铸造工艺设计及智能优化

使用Cast Designer铸造仿真分析软件,通过可铸性评估系统DFM,完成浇冒系统的辅助设计,然后使用DOE技术和基于遗传算法GA的智能优化技术,评估不同工艺设计方案与铸造过程参数对壳体铸件质量的影响,分析在不同的冒口、冷铁和浇注温度条件下得料率和缩孔量的关系。根据对DOE模拟结果的分析,发现顶冒口和侧冒口尺寸是影响得料率和缩孔量的关键因数,再利用遗传算法GA选择最佳设计方案和参数。通过帕累托曲线得到了生产壳体铸件的最优工艺方案。

Robust H_∞ Controller Design for Uncertain Neutral Systems via Dynamic Observer Based Output Feedback

In this paper, the dynamic observer-based controller design for a class of neutral systems with H∞ control is considered. An observer-based output feedback is derived for systems with polytopic parameter uncertainties. This controller assures delay-dependent stabilization and H∞ norm bound attenuation from the disturbance input to the controlled output. Numerical examples are provided for illustration and comparison of the proposed conditions.

Temperature effects of shape memory alloys(SMAs)in damage control design of steel portal frames

The objective of the present study is to analytically investigate temperature effects of an axial-type seismic damper made of shape memory alloys(SMAs)equipped in steel frames.Based on a modified multilinear one dimensional constitutive model of SMAs,two types of SMAs are employed,which have different stress plateau and different stress growth rate with temperature increase.Temperature effects of SMA dampers on seismic performance upgrading are discussed in three aspects:different environment temperatures;rapid loading rate induced heat generation and different SMA fractions.The analysis indicates that the effect of environment temperature should be considered for the SMA damper in steel frames.However,the rapid loading rate induced heat generation has little adverse effect.

Iterative identification and control design with optimal excitation signals based on v-gap

An iterative identification and control design method based on v-gap is given to ensure the stability of closed-loop system and control performance improvement. The whole iterative procedure includes three parts： the optimal excitation signals design, the uncertainty model set identification and the stable controller design. Firstly the worst case v-gap is used as the criterion of the optimal excitation signals design, and the design is performed via the power spectrum optimization. And then, an uncertainty model set is attained by system identification on the basis of the measure signals. The controller is designed to ensure the stability of closed-loop system and the closed-loop performance improvement. Simulation result shows that the proposed method has good convergence and closed-loop control performance.

Parametric study on damage control design of SMA dampers in frame-typed steel piers

This paper focuses on damage control design of SMA dampers in steel frame piers.A parametric study based on time history analyses is carried out on frametyped bridge piers with axial-type SMA damping device.The parameters examined are design parameters of strength ratioαF and stiffness ratioαK.Seismic performance indexes on displacement and strain are investigated under three JRA recommended Level 2 Ground TypeПstrong earthquake motions.Design recommendations are suggested following the results of the parametric study.

Design and Efficient Controller for Micro Turbine System

In this modern era, power generation seems to be a very demanding factor. New models and methods have been proposed to derive from various natural and manmade resources. In such instances, this paper gives a detailed report on the power generation from Micro Turbines. Micro turbine plays a very important role in electric power generation. Especially they are used in the combined cycle process power plants. The parameters of Rowen’s model 265-MW single shaftheavy duty gas turbines which are used in dynamic studies are estimated in this paper using the operational and performance data. These data are also used to briefly explain the extraction of parameters of the used model. Micro turbine parameters are approximated using simple thermodynamics assumptions. Micro turbine power generation seems to be an uprising and a promising source and an exact design with a perfect model is capable of producing the highest efficiency. Thus this paper is proposed on the aspects of social awareness to elaborate the control design of Micro Turbine Power Generation System. The parameters of micro turbine models are derived and the results of several simulated tests using Matlab/Simulink are presented.

Proto col Design for Output Consensus of Port-controlled Hamiltonian Multi-agent Systems

这份报纸调查控制港口的 Hamiltonian (PCH ) 多代理人系统的产量一致问题与修理并且切换的拓扑学。第一，一个分布式的组产量一致协议经由塑造方法全球性到达稳定性和组产量一致的能量被设计。第二，一个新分布式的控制协议被使用 PCH 系统的结构的性质建议。这个协议的优点是它能由构造一种虚拟邻居转变指导的图到未受指导的图。第三，一个控制协议被设计，扩大 LaSalle0s 不变性原则在联合连接的拓扑学条件下面为交换系统发展了让所有代理人当拓扑学正在切换时，到达输出一致。最后，有模拟的一些解说性的例子被提供表明在这份报纸设计的协议的有效性。

Randomized Algorithms for Probabilistic Optimal Robust Performance Controller Design

Polynomial-time randomized algorithms were constructed to approximately solve optimal robust performance controller design problems in probabilistic sense and the rigorous mathematical justification of the approach was given. The randomized algorithms here were based on a property from statistical learning theory known as (uniform) convergence of empirical means (UCEM). It is argued that in order to assess the performance of a controller as the plant varies over a pre-specified family, it is better to use the average performance of the controller as the objective function to be optimized, rather than its worst-case performance. The approach is illustrated to be efficient through an example.

Controller design of uncertain nonlinear systems based on T-S fuzzy model

A robust control for uncertain nonlinear systems based on T-S fuzzy model is discussed in this paper. First, a T-S fuzzy system is adopted to model the uncertain nonlinear systems. Then, for the system with input variables adopting standard fuzzy partitions, the efficient maximal overlapped-rules group （EMORG） is presented, and a new sufficient condition to check the stability of T-S fuzzy system with uncertainty is derived, which is expressed in terms of Linear Matrix Inequalities. The derived stability condition, which only requires a local common positive definite matrix in each EMORG, can reduce the conservatism and difficulty in existing stability conditions. Finally, a simulation example shows the proposed approach is effective.

CAutoCSD-Evolutionary Search and Optimisation Enabled Computer Automated Control System Design

This paper attempts to set a unified scene for various linear time-invariant (LTI) control system design schemes, by transforming the existing concept of “computer-aided control system design” (CACSD) to novel “computer-automated control system design” (CAutoCSD). The first step towards this goal is to accommodate, under practical constraints, various design objectives that are desirable in both time and frequency domains. Such performance-prioritised unification is aimed at relieving practising engineers from having to select a particular control scheme and from sacrificing certain performance goals resulting from pre-commitment to such schemes. With recent progress in evolutionary computing based extra-numeric, multi-criterion search and optimisation techniques, such unification of LTI control schemes becomes feasible, analytical and practical, and the resultant designs can be creative. The techniques developed are applied to, and illustrated by, three design problems. The unified approach automatically provides an integrator for zero-steady state error in velocity control of a DC motor, and meets multiple objectives in the design of an LTI controller for a non-minimum phase plant and offers a high-performance LTI controller network for a non-linear chemical process.

Systematic design method for PI controller with Virtual Resistor-based Active Damping of LCL filter

The Virtual Resistor based Active Damping(VR-AD) is widely employed in converters connected to the grid via LCL filters in order to mitigate the inherent resonance of the filters. Nevertheless, in digitally controlled systems, the PWM and the calculating delays modify the system characteristics in terms of frequency and phase, thus destabilizing the system and degrading the VR-AD performances, mainly in low switching frequencies. Moreover, the stability of the system is greatly affected under weak grid operation characterized by large grid impedance variation. This paper solves these problems by proposing a systematic, robust and optimized design procedure of voltage oriented PI control(VOC) with VRAD. The considered design procedure ensures robust control(sufficient stability margins) and high quality of grid current(reduced steady-state error and minimized THD value) despite the negative impact of digital time delay, grid impedance variation and filter parameters change. Simulation and experimental results are presented to show robustness and efficiency of the suggested design procedure.

New developments in control design techniques of logical control networks

The control design problem plays a fundamental role in the study of logical control networks(LCNs).This paper presents a detailed survey on new developments in control design techniques of LCNs.First,some preliminary results on the semi-tensor product method and LCNs are reviewed.Then,we move on to some new developments for control design techniques of LCNs,including the reachable set approach,the pinning control technique,the control Lyapunov function approach,the event-triggered control technique,and the sampled-data control technique.Finally,an illustrative example is given to demonstrate the effectiveness of these techniques.