Robust loop shaping-fuzzy gain scheduling control of a servo-pneumatic system using particle swarm optimization approach

In this paper, a new technique called robust loop shaping-fuzzy gain scheduled control (RLS-FGS) is proposed to design an effective nonlinear controller for a long stroke pneumatic servo system. In our technique, a nonlinear dynamic model of a long stroke pneumatic servo plant is identified by the fuzzy identification method and is used as the plant for our design. The structure of local controllers is selected as PID control which is proven by many research works that this type of control has many advantages such as simple structure, well understanding, and high performance. The proposed technique uses particle swarm optimization (PSO) to find the optimal local controllers which maximize the average stability margin. In addition, performance weighting function which is normally difficult to obtain is automatically determined by PSO. By the proposed technique, the RLS-FGS controller can be designed, and the structure of local controllers is still not complicated. As seen in the simulation and experimental results, our proposed technique is better than the classical gain scheduled PID controller tuned by pole placement and the conventional fuzzy PID controller tuned by ISE method in terms of robust performance.     

SDN‐based wireless body area network routing algorithm for healthcare architecture

The use of wireless body area networks (WBANs) in healthcare applications has made it convenient to monitor both health personnel and patient status continuously in real time through wearable wireless sensor nodes. However, the heterogeneous and complex network structure of WBANs has some disadvantages in terms of control and management. The software‐defined network (SDN) approach is a promising technology that defines a new design and management approach for network communications. In order to create more flexible and dynamic network structures in WBANs, this study uses the SDN approach. For this, a WBAN architecture based on the SDN approach with a new energy‐aware routing algorithm for healthcare architecture is proposed. To develop a more flexible architecture, a controller that manages all HUBs is designed. The proposed architecture is modeled using the Riverbed Modeler software for performance analysis. The simulation results show that the SDN‐based structure meets the service quality requirements and shows superior performance in terms of energy consumption, throughput, successful transmission rate, and delay parameters according to the traditional routing approach.     

Variable-structured robust controller by fuzzy logic forservomotors

A variable-structure robust controller whose structure is continuously changed by fuzzy logic so that the system responds quickly if the error or its rate is large and vice versa is proposed. Such a controller is insensitive to both the plant noise and the observation noise. It is applied to speed control for an induction servomotor. Experiments show that the controller is superior to both a sliding-mode controller and a proportional integral-derivative (PID) controller. The paper includes the stability analysis of the overall system and the design procedure by using Lyapunov's method     

Protocol design and performance analysis for manufacturing messagespecification: A Petri net approach

The manufacturing message specification (MMS) is the ISO standard communication protocol specific to manufacturing. To analyze MMS design and performance, service unit automats are introduced to represent individual MMS services, while service connection Petri Nets (PNs) are constructed from these automats to describe MMS service connections and processes. This approach makes MMS protocol specification and analysis possible in terms of well-developed concepts and methods in PN theory. It leads to a distributed and hierarchical model of MMS software system by integrating service connection PNs. A generalized stochastic PN for MMS performance evaluation is obtained by incorporating service parameters and time factors into the model. A technique based on T-invariants is used to simplify the performance analysis     

一种STN LCD控制器的设计及其实现

介绍了一种超扭曲向量(STN)LCD控制器的设计方案,详细分析了该控制器各模块的划分及其功能,用Verilog硬件描述语言完成了整个LCD控制器的设计工作,并用Cadence Verilog-XL软件对设计结果进行了仿真验证.仿真结果表明该LCD控制器实现了预定的设计目标.     

Perfect tracking control based on multirate feedforward controlwith generalized sampling periods

In this paper, a novel perfect tracking control method based on multirate feedforward control is proposed. The advantages of the proposed method are that: (1) the proposed multirate feedforward controller eliminates the notorious unstable zero problem in designing the discrete-time inverse system; (2) the states of the plant match the desired trajectories at every sampling point of reference input; and (3) the proposed controller is completely independent of the feedback characteristics. Thus, highly robust performance is assured by the robust feedback controller. Moreover, by generalizing the relationship between the sampling period of plant output and the control period of plant input, the proposed method can be applied to various systems with hardware restrictions of these periods, which leads to higher performance. Next, it is shown that the structure of the proposed perfect tracking controller is very simple and clear. Illustrative examples of position control using a DC servomotor are presented, and simulations and experiments demonstrate the advantages of this approach     

Robust and fault-tolerant linear parameter-varying control of wind turbines

High performance and reliability are required for wind turbines to be competitive within the energy market. To capture their nonlinear behavior, wind turbines are often modeled using parameter-varying models. In this paper we design and compare multiple linear parameter-varying (LPV) controllers, designed using a proposed method that allows the inclusion of both faults and uncertainties in the LPV controller design. We specifically consider a 4.8 MW, variable-speed, variable-pitch wind turbine model with a fault in the pitch system.We propose the design of a nominal controller (NC), handling the parameter variations along the nominal operating trajectory caused by nonlinear aerodynamics. To accommodate the fault in the pitch system, an active fault-tolerant controller (AFTC) and a passive fault-tolerant controller (PFTC) are designed. In addition to the nominal LPV controller, we also propose a robust controller (RC). This controller is able to take into account model uncertainties in the aerodynamic model.The controllers are based on output feedback and are scheduled on an estimated wind speed to manage the parameter-varying nature of the model. Furthermore, the AFTC relies on information from a fault diagnosis system.The optimization problems involved in designing the PFTC and RC are based on solving bilinear matrix inequalities (BMIs) instead of linear matrix inequalities (LMIs) due to unmeasured parameter variations. Consequently, they are more difficult to solve. The paper presents a procedure, where the BMIs are rewritten into two necessary LMI conditions, which are solved using a two-step procedure.Simulation results show the performance of the LPV controllers to be superior to that of a reference controller designed based on classical principles.     

基于双余度飞机防滑刹车控制系统的设计与实现

飞机防滑刹车控制器是飞机制动系统的核心系统。设计了一种双余度的新型数字防滑刹车控制器,结合飞机防滑刹车系统的功能要求,提出了以多通道、硬件非相似双余度的刹车控制器设计方案,采用速度差加压力偏调（PBM＋PD）控制算法,完成了飞机防滑刹车控制器的软硬件设计及系统调试。试验结果表明,该防滑刹车控制系统工作稳定可靠,结构简单,易于实现,能够满足飞机全电防滑刹车的要求。     

MAS based embedded control system design method and a robot development paradigm

This paper summarizes a MAS based embedded control system design method for complex mechatronic system. Regarding the local controller as an agent-task and based on MAS viewpoint, a practical system can be modeled in firmware/software level. By using the multitasking capability of RTOS to realize the agent-tasks and using the system service of RTOS to construct the MAS’s coordination mechanism, we can implement the MAS in embedded system. A new tele-operation mobile robot, named PBJ-2, is introduced as a development example to explain this method. An improved MAS based manipulator control method is also presented in detail. The PBJ-2’s controller is built as an embedded system that running RTOS on an ARM7TDMI-S microcontroller. The whole development process is introduced in this paper, from the agents’ partitions and the MAS design to the actual hardware and firmware architectures design, in detail. By using the MAS based embedded control system design method, the development procedure is high efficiency and clear hierarchy. The ultimate goal of the work is to get seamless routes from system specifications to its implementation.     

Design and Implementation of Modular FPGA-Based PID Controllers

In this paper, modular design of embedded feedback controllers using field-programmable gate array (FPGA) technology is studied. To this end, a novel distributed-arithmetic (DA)-based proportional-integral-derivative (PID) controller algorithm is proposed and integrated into a digital feedback control system. The DA-based PID controller demonstrates 80% savings in hardware utilization and 40% savings in power consumption compared to the multiplier-based scheme. It also offers good closed-loop performance while using less resources, resulting in cost reduction, high speed, and low power consumption, which is desirable in embedded control applications. The complete digital control system is built using commercial FPGAs to demonstrate the efficiency. The design uses a modular approach, so that some modules can be reused in other applications. These reusable modules can be ported into Matlab/Simulink as Simulink blocks for hardware/software cosimulation or integrated into a larger design in the Matlab/Simulink environment to allow for rapid prototyping applications.     

一种新型图形式LCD控制芯片的设计及实现

文章介绍了图形式LCD视频控制芯片的设计方案，详细分析了该控制芯片的系统设计和各模块的功能实现，讨论、分析了模拟电路部分的设计并用Verilog硬件描述语言完成了芯片数字部分的设计工作。用Modelsim软件对设计结果进行了仿真，仿真成功后在FPGA板上实现了系统的显示功能，其结果表明该芯片实现了预定的设计目标。     

Internal model control (IMC) approach for designing disk driveservo-controller

This paper presents a design procedure for disk drive servomechanism using an internal model control (IMC) structure. A typical disk drive actuator can be modeled as second order dynamics for low frequencies. However the response at higher frequencies shows resonant behavior which is difficult to model. We discuss the use of IMC structure for designing servo-controllers for disk drives. In this method, a second order nominal model of the plant is used to design an H ₂-optimal controller to attain minimum integral-error-square (ISE) performance. Then to maintain robust stability at higher frequencies, sufficient roll-off at such frequencies is provided by an H _∞ optimization procedure. Here, the H₂-optimal control is augmented by a low pass filter with sufficient high-frequency roll-off to ensure robust stability and robust performance. A multiplicative uncertainty bound is defined using the data of the disk drive servo plant's frequency response and the response of the nominal model, and this is then used to decide robust stability and robust performance bounds. Tuning of only one parameter of the IMC filter makes this design method easy and convenient. Simulation results for the designed controller are presented     

Design of a perturbation estimator using the theory ofvariable-structure systems and its application to magnetic levitationsystems

A perturbation estimator using the theory of variable structure systems is proposed to enhance the robustness of a pole-placement controller design. In its ideal form, the pole-placement design using feedback-linearization technique achieves a desired performance in nonlinear time-varying systems. However, its performance deteriorates rapidly with the presence of disturbance and parametric uncertainties, referred to as perturbation. The estimate generated by the proposed perturbation estimator is incorporated as an additional input to rectify the uncertainties in the nominal control model of the pole-placement design. The proposed scheme requires neither the measurement of the time derivative of the state vector nor the precise knowledge of system parameters, hut rather the bounds on system perturbation. Chatter and the adverse effects of conservative bounds on system perturbation, often encountered in conventional sliding-mode control (SMC), are alleviated for the controlled plant by the proposed scheme. The benefits of this scheme are demonstrated in this study practically on a magnetic levitation system and its performance is compared with that of the conventional SMC scheme     

A generic cell controller for the automated VLSI manufacturingfacility

A generic cell controller has been designed and developed for an automated VLSI manufacturing facility. The components of the design phase include the detailed understanding of motivation for the effort, a requirements analysis (functional specification), a determination of design goals, a determination of appropriate assumptions, a feasibility design, and an initial performance evaluation. The design is quite modular and enhances the generic attributes of cell controller operation. The cell controller design is independent of the facility hardware, software, and networking base, and may be adapted to a single or multitasking system. The main component of the design is an extensive relational database with a relatively uncomplicated and generic schema. This database incorporates many of the control aspects of the cell controller, thus reducing the volume of control software. An initial performance evaluation indicates that the design is suitable for operation as a cell controller even when implemented on a relatively slow single tasking PC     

高空作业车智能控制器的设计与开发

为了改善高空作业车的作业性能,设计了一款高空作业车智能控制器,解决了完全依靠操作人员的视觉反馈以及用机械调速阀对机构进行控制,精确性能差的问题,提高了操作的安全智能性、可靠性。在介绍了高空作业车控制系统组成基础上,首先给出了智能控制器的整体框架结构,再对控制器的软硬件设计实现进行了阐述。在实际车辆测试中,工作稳定,性能达到了预期设计效果。     

基于PLC污水检测系统的设计与应用

提出一种基于PLC的远程污水智能监控系统的设计方法.通过传感器采集设备长时间监控污水的变化情况,运用无线网络技术实时传递污水现场的情况,针对传递中的信号存在大量噪声,提出信号去噪方案,结合污水监控系统的要求,给出了基于可编程控制器的污水监控控制系统的硬件结构设计以及各个部分的软件设计.该方案设计的系统能够有效的监控污水泄露并反馈信息,取得了令人满意的效果.     

Ladder diagram and Petri-net-based discrete-event control design methods

Ladder diagrams (LDs) for a programmable logic controller are a dominant method in discrete event control of industrial automated systems. Yet, the ever-increasing functionality and complexity of these systems have challenged the use of LDs to design their discrete-event controllers. Researchers are constantly pursuing integrated tools that eliminate the limitations of LDs. These tools are aimed not only for control but also system analysis, evaluation, and simulation. For the past several decades, Petri nets (PNs) have emerged as an important tool to provide an integrated solution for modeling, analysis, simulation, and control of industrial automated systems. Different types of PN-based controllers are proposed and intended to apply in the industry. There is a need for more benchmark studies of PN and LD methods in order to form a structured and integrated framework for logic control software development. This paper, for the first time, presents a comprehensive survey on the recent methods for discrete event control design.     

同/异步短码DS-CDMA信号伪码序列及信息序列盲估计

针对传统单通道异步直接序列码分多址(DS-CDMA)信号信息序列及伪码序列(PN)难以估计的问题,该文提出一种基于平行因子(PARAFAC)的多通道盲估计方法。该方法首先将信号建模为多通道接收模型,然后将观测数据矩阵等效为平行因子模型,最后使用迭代最小二乘算法对平行因子进行低秩分解,进一步完成对DS-CDMA信号各用户的信息序列及伪码序列进行估计。仿真实验表明,该方法不仅能有效地对同步、异步短码DS-CDMA信号的伪码序列及信息序列进行估计,而且能在通道数为6、信噪比(SNR)为–10 dB的条件下,实现10个用户伪码序列的有效估计。     

小型污水厂远程监控系统设计

为了实现对污水厂远程监控系统的需求,文中提出了基于ARM的小型污水厂远程监控系统设计方案,并完成了系统软硬件设计。文中采用ARM微处理器为主控制器,用模数转换采集现场数据,用摄像头采集现场图片,采用GPRS无线通信模块传输采集的信息,实现了小型污水厂图像和数据的采集、存储和无线传输功能。     

弧焊电源的设计及Matlab仿真

介绍了开关电源的优点和大功率弧焊电源的结构,给出了以DSP芯片为控制器的大功率弧焊电源的设计方法。同时,详细介绍了弧焊电源主回路的设计方案和主回路中主要元件的选型,并且对元件参数的选择给出了具体的计算方法,并应用Matlab 7.0仿真工具对主回路建模并进行仿真,得到了与设计要求相符合的实验结果,通过对仿真结果的分析验证了设计方案的可行性。