Optimum shape design of a BLDC motor for electric continuous variable valve timing system considering efficiency and torque characteristics

Microsystem Technologies - Recently, environmental problems caused by global warming and exhaust gas have been increasing, leading governments all over the world to implement strict environmental...     

一种基于控制卡和RS422接口电缆的电机控制系统

用Microsoft Visual C++6.0编辑界面程序,设计一种基于绝对位置的电机控制系统。设置驱动器、运动控制卡中的参数,调用运动控制卡中的库函数,使用脉冲串加符号控制伺服电机的转速与转向。使用RS422接口电缆配合控制卡保证断电又上电后伺服电机的原点回归。     

A study of electric vehicle suspension control system based on an improved half-vehicle model

An improved half-vehicle model has been proposed for active suspension control systems,in contrast to existing models, it allows to explore the nature of the effect of vehicle speed changes by introducing a state vector of vehicle pitch angle.Three control strategies of linear quadratic control (LQ),improved LQ (ILQ) and wheelbase preview LQ (WLQ) have been implemented into the proposed model.ILQ has integrated an additional control parameter into LQ by concerning the correlation between acceleration values and their corresponding pitch angles.Simulation results have showed the effectiveness of the proposed model in terms of LQ,ILQ and WLQ control strategies.     

基于全可变气门汽油机进气量测量和控制问题研究

基于全可变气门运动机构的气门参数控制燃烧技术是改善传统SI汽油机燃油经济性,提高动力性和降低排放的最为有效的途径之。但是这也对发动机进气量的测量和控制提出了更高的要求。本文通过仿真和试验相结合的方法,对基于全可变气门机构汽油机进气量测量和控制问题进行了探讨和研究。     

pH值系统变论域模糊控制器的设计及性能分析

针对pH值非线性控制系统,设计了一种实时简化变论域模糊控制器.将变论域思想与实时模糊推理策略相结合:一方面论域随着误差的减小而收缩,而论域的收缩相当于控制规则的增加,从而增加了控制精度;另一方面采用实时模糊推理方法,即对于一个二入一出的模糊控制器,一次推理过程中最多只激活4条控制规则,在控制的过程中只考虑这4条控制规则.这2种思想的结合使得控制规则的设计大大简化,可以采用批处理的方式设计控制器,不仅加快了系统的动态响应,也提高了控制精度.仿真结果证实了这种控制方法的有效性.     

A study on tracking position control of an electropneumatic system using backstepping design

As an important driving element, the pneumatic cylinder is widely used in industrial applications due to its reliability, low cost and excellent performance in an industrial servo systems. However, along with the development of control technology, the requirement for control precision gets higher and higher. In many cases, in order to achieve the satisfied control performance, nonlinear control techniques are used. Backstepping is one of these nonlinear control techniques that has attracted a great deal of research interest in the last years. It is mainly applicable to strict-feedback system. This paper presents a new form of backstepping controller for an electropneumatic system. It should be noticed that the model of this system is not under strict-feedback form. Then, a modified methodology is proposed, synthesized and implemented on an experimental test bench. Experimental results are presented and discussed.     

Optimization and improvement of a robotics gaze control system using LSTM networks

Multimedia Tools and Applications - Gaze control represents an important issue in the interaction between a robot and humans. Specifically, deciding who to pay attention to in a multi-party...     

Identification of a process with control valve stiction using a fuzzy system: A data-driven approach

Many researchers focus on detecting and modelling the valve stiction because it has undesirable effects on the control loop performance, which consequently results in poor product quality and increased energy consumption. It is difficult to model a process with a sticky valve using the mathematical definition because of its nonlinear properties such as stiction, hysteresis, dead band and dead zone. This work aims to develop and determine the appropriate model of a process with stiction, which can be used in controller design to mitigate the undesirable effect of the stiction. To achieve this goal by mapping the process with valve stiction to a fuzzy system, a dynamic fuzzy model of the plant is derived through an iterative well-developed fuzzy clustering algorithm, which generates suitable antecedent parameters from a set of input–output measurements that are obtained from the control output (OP) and the process output (PV). To determine the consequent parameters, the least square (LS) estimation is applied. The results reveal that the obtained data-driven Takagi–Sugeno-type (TS) fuzzy rule-based model can effectively represent an appropriate model of the process with stiction for different amounts of stiction that are obtained from the simulation and different industrial loops.     

Intelligent control of a stepping motor drive using an adaptive neuro–fuzzy inference system

Stepping motors are widely used in robotics and in the numerical control of machine tools where they have to perform high-precision positioning operations. However, the variations of the mechanical configuration of the drive, which are common to these two applications, can lead to a loss of synchronism for high stepping rates. Moreover, the classical open-loop speed control is weak and a closed-loop control becomes necessary. In this paper, fuzzy logic is applied to control the speed of a stepping motor drive with feedback. A neuro-fuzzy hybrid approach is used to design the fuzzy rule base of the intelligent system for control. In particular, we used the ANFIS methodology to build a Sugeno fuzzy model for controlling the stepping motor drive. An advanced test bed is used in order to evaluate the tracking properties and the robustness capacities of the fuzzy logic controller.     

Tracking performance characterization and improvement of a piezoactuated micropositioning system based on an empirical index

Motion tracking is an important problem in micropositioning systems dedicated to ultra-precision robotic micromanipulation. This paper investigates the periodic motion tracking performance of a micropositioning system based on an empirical tracking performance index (TPI), which is proposed with the consideration of both tracking errors and tracking frequencies. To improve the TPI of a micropositioning system with piezoelectric actuation, a two-loop controller consisting of an _H∞$H_{\infty }$ robust controller and a disturbance observer is implemented. Experimental studies are conducted on an XY parallel micropositioning system for the motion tracking tests. Results demonstrate that a sole _H∞$H_{\infty }$ robust controller is insufficient to produce a satisfactory tracking performance with low-frequency control. In contrast, the two-loop controller endows the system with both a lower tracking error and a better TPI than the conventional robust control does. The experimental results not only validate the effectiveness of the proposed control method in improving tracking performance but also confirm the feasibility of the TPI in quantitatively characterizing the performance of a micropositioning system.     

A comparative study of the improvement of performance using a PSO modified by ACO applied to TSP

Swarm-inspired optimization has become very popular in recent years. Particle swarm optimization (PSO) and Ant colony optimization (ACO) algorithms have attracted the interest of researchers due to their simplicity, effectiveness and efficiency in solving complex optimization problems. Both ACO and PSO were successfully applied for solving the traveling salesman problem (TSP). Performance of the conventional PSO algorithm for small problems with moderate dimensions and search space is very satisfactory. As the search, space gets more complex, conventional approaches tend to offer poor solutions. This paper presents a novel approach by introducing a PSO, which is modified by the ACO algorithm to improve the performance. The new hybrid method (PSO–ACO) is validated using the TSP benchmarks and the empirical results considering the completion time and the best length, illustrate that the proposed method is efficient.     

融合运动想象脑电与眼电信号的机械臂控制系统开发

脑机接口(brain computer interface, BCI)旨在通过脑电信号与外部设备通信,以实现对外部设备的控制。针对目前脑机接口系统中混合多种复杂生理电信号,并且输出控制指令较少的问题,本文提出融合运动想象(motor imagery, MI)脑电与眼电信号方法扩充控制指令的轻量级机械臂控制系统。该系统分阶段融合脑电和眼电信号两种生物信号,使用双次眼电作为任务开关,运动想象脑电信号控制机械臂运动,单次眼电控制阶段切换,实现了二分类运动想象生成多种控制指令,完成了对机械臂的连续控制。其中运动想象脑电信号使用提升小波变换(lifting wavelet transform, LWT)和共空间模式(common spatial pattern, CSP)结合的方法提取特征,并采用支持向量机(support vector machines, SVM)进行分类;眼电信号通过分析无意识眼电和有意识眼电的峰值来设置阈值进行区分。为了验证系统的可行性,设计了一项脑控机械臂自主服药实验,通过在线实验测试,被试通过使用脑电信号和眼电信号实现了机械臂控制,并完成了服药流程,有利于进一步推广脑机接口技术的实际应用。     

Modeling, simulation, and control of an electromechanical aerofin control system with a PWM-controlled DC motor

A nonlinear model of an electromechanical actuator (EMA) system for aerofin control is presented. The EMA is realized with a permanent magnet brush DC motor controlled by a constant current driver. In this paper we introduced a simulation model that includes nonlinearities of the motor driver. A PID position controller was designed using the simulation model, although it was impossible to develop a linear model. The simulation results have been of the great importance for understanding the system behavior and successful control system implementation. The proposed control system has experimentally been validated on a test bench. The EMA-AFC test bench is designed to provide real operating conditions. The text was submitted by the authors in English.     

A performance study of a FileServer system on the AppleTalk personal network

In this paper the results of a performance study of a FileServer System running on the AppleTalk Personal Network are described. The performance indices measured are mean and maximum file transfer times, and mean and system throughput. The experiments were designed so that these performance indices could be measured against system load, file size, packet size, acknowledge window size, and the number of requesters. Our methods of experiments were discussed and in particular the approach used to measure the influence of the number of requesters was presented. The results of the experiments were discussed together with some problems encountered. Suggestions were presented for further projects following on from these experiments. From the results of the study, it is concluded that the FileServer System on the AppleTalk Personal Network could be used effectively in offices and at universities in computer network courses.     

Optimal fuzzy control system using the cross-entropy method. A case study of a drilling process

This paper focuses on the optimal tuning of fuzzy control systems using the cross-entropy precise mathematical framework. The design of an optimal fuzzy controller for cutting force regulation in a network-based application and applied to the drilling process is described. The key issue is to obtain optimal fuzzy controller parameters that yield a fast and accurate response with minimum overshoot by minimising the integral time absolute error (ITAE) performance index. Simulation results show that the cross-entropy method does find the optimal solution (i.e. input scaling factors) very accurately, and it can be programmed and implemented very easily (few setting parameters). The results of a comparative study demonstrate that optimal tuning with the cross-entropy method provides a good transient response (without overshoot) and a better error-based performance index than simulated annealing [17], the Nelder-Mead method [14] and genetic algorithms [33]. The experimental results demonstrate that the proposed optimal fuzzy control provides outstanding transient response without overshoot, a small settling time and a minimum steady-state error. The application of optimal fuzzy control reduces rapid drill wear and catastrophic drill breakage due to the increasing and oscillatory cutting forces that occur as the drill depth increases.     

Optimal control of the spin system on a basis of the global improvement method

The paper considered computing experiments on application of the Krotov method of global (nonlocal) improvement to one problem of the optimal control of a quantum system obeying the Schrödinger equation with a Hamiltonian in the Landau-Zener form.     

Determining the timing of project control points using a facility location model and simulation

Projects are usually performed in relatively unstable environments. As such, changes to the baseline schedules of projects are inevitable. Therefore, project progress needs to be monitored and controlled. The control process can be assumed as a continuum in which one side is continuous control and the other side is no-control. Continuous control and no-control strategies are cost-wise prohibited. Hence, project progress should be controlled at some discrete points in time during the project׳s duration. The optimal number and timing of control points are the main issues that should be addressed. In this paper, taking a dynamic view to the project control, for the first time we use an adapted version of the facility location model (FLM) to find the optimal timing of project control points. Initially, the adapted FLM determines the optimum timing of the control points in the project׳s duration. A simulation model is then used to predict the possible disruptions in the time period between the beginning of the project and the first control point (monitoring phase). If no disruptions are observed, the project׳s progress is monitored in the second control point, otherwise possible corrective actions are taken using an activity compression model. Whenever due to disruptions, the baseline schedule is to be updated, the FLM is run again to determine the new timing of the control points for the rest of the project׳s duration. In an iterative manner, this process continues until the timing of the last control point is determined.     

Comments on "Integral variable structure control of nonlinear system using a CMAC neural network learning Approach"

In the above paper, an adaptive integral variable structure control scheme using CMAC neural networks was proposed for a class of uncertain nonlinear systems. The author of the above paper claimed that the proposed controller ensures convergence of the tracking error to zero (see property 2 of Theorem 1). In this note, we point out that the proof of the property 2 is incorrect and therefore this property is untenable.     

Research on the computer monitoring and control system of diesel motor

The working conditions of diesel motors used in somespecial condition are complex. By using microcomputer control,A/D conversion and digital tele-communication techniques, au-tocontrol of the working process, digital sampling of parameters,tele-communication concentrative monitoring and control are real-ized.When the signal sampled goes beyond the limit,the station alarms,reacts automatically and stops authomatically if necessary.