Cross-coupled fuzzy logic control for multiaxis machine tools

This paper presents a design and implementation case study that focuses on contour control of a biaxial CNC machine tools. Since, it is difficult to obtain an accurate nonlinear mathematical model of cross-coupled multiaxis machine tools, here we investigate an alternative to conventional approaches where we employ crosscoupled fuzzy logic controllers for improving the contouring accuracy of multiaxis CNC machine tools. A new fuzzy rule-generated method which is based on a performance index of the contour error obtained from an on-line estimation algorithm is proposed. An adapted output scale factor is adopted to improve the system performance. Experimental results have shown that the desired contouring accuracy can be achieved, and the proposed approach outperforms over uncoupled approaches. In conventional control, increasing contour feedrate for productivity may result in larger contour errors. However, the experimental results have shown that the performance of the proposed approach is still quite good with increasing contour feedrate.     

Hybrid control system design using a fuzzy logic interface

A hybrid control system is proposed for regulating an unknown nonlinear plant. The interface between the continuous-state plant and the discrete-event supervisor is designed using a fuzzy logic approach. The fuzzy logic interface partitions the continuous-state space into a finite number of regions. In each region, the original unknown nonlinear plant is approximated by a fuzzy logic-based linear model, then state-feedback controllers are designed for each linear model. A high-level supervisor coordinates (mode switching) the set of closed-loop systems in a stable and safe manner. The stability of the system is studied using nonsmooth Lyapunov functions. For illustration and verification purposes, this technique has been applied to the well-known inverted pendulum balancing problem.     

3D Feedback control using fuzzy logic for a curvature-controllable steerable bevel-tip needle

Owing to numerous advantages to patients, percutaneous intervention has become a popular research topic in recent decades. To improve trajectory following accuracy, many robotic steering systems have been developed using various advanced control algorithms. To overcome the complicated modeling procedures, this study proposed a three-dimensional (3D) feedback control method based on fuzzy logic for a steerable needle that did not require an exhaustive mathematical derivation. A 3D kinematic model of a curvature-controllable steerable (CCS) needle was obtained, and the spatial trajectory following controller using fuzzy logic for the CCS needle was presented. A series of simulations using the kinematic model were carried out to validate the accuracy of the model and control strategies. The experimental results showed that the proposed control system could accurately steer the CCS needle along a 3D path.     

模糊逻辑与模糊控制技术的发展与研究

针对现代工业控制领域的模糊控制技术的新发展,综合介绍了该领域的基本理论和发展现状,展望了未来的发展应用。     

Remote fuzzy logic control of networked control system via Profibus-DP

This paper focuses on the feasibility of fuzzy logic control for networked control systems (NCSs). In order to evaluate its feasibility, a networked control system for servo motor control is implemented on a Profibus-DP network. The NCS consists of several independent, but interacting, processes running on two separate stations. By using this NCS, the network-induced delay is analyzed to find the cause of the delay. Furthermore, the fuzzy logic controller's performance is compared with that of conventional proportional-integral-derivative controllers. Based on the experimental results, it is found that the fuzzy logic controller can be a viable choice for an NCS due to its robustness against parameter uncertainty.     

Spectrum handoff in cognitive radio with fuzzy logic control

The secondary usage of spectrum has been investigated in Cognitive Radio (CR) network to resolving the spectrum scarcity issue in wireless communication. When Primary Users (PU) who own the spectrum appear, spectrum handoff is needed to maintain the communications of Secondary Users. But the decision making of spectrum handoff is a challenge issue for CR network, because the input of decision making, which obtain through spectrum sensing, is heterogeneous and inexact. In this paper we will use fuzzy logic control theory to solve this issue and make use of new information for handoff operation: the probability of PU’s occupancy at a certain channel. Our new algorithm can make more intelligent decision compared to simple traditional spectrum handoff decision making and reduce the probability of spectrum handoff, also the performance of SU’s communication can be enhanced.     

联合多分组接收和模糊逻辑控制功率策略

针对无线网络节约能耗的要求,提出了一种联合多分组接收和模糊逻辑控制功率策略,采用串行干扰消除法,根据无线节点的传输功率等级,将功率等级划分为多分组接收能够正常解码的功率等级,并以任一无线节点到邻接节点的距离、邻接节点的个数和无线节点的剩余能耗为模糊逻辑控制的输入参数来控制各无线节点的功率选择。仿真结果表明,与现有的几种经典的基于功率控制的串行干扰消除算法方案相比,联合多分组接收和模糊逻辑控制功率策略的无线网络具有更大的有效吞吐量及更长的生存时间。     

ATM traffic management and congestion control using fuzzy logic

The paper focuses on the use of fuzzy logic in network management, ATM congestion control, and ATM switching. The ATM network management ensures traffic agreement at the source level in order to prevent congestion situations from occurring. The paper reviews work in the area of traffic policing and introduces a scheme for improving the performance of a fuzzy policer. The ATM fuzzy switch introduced, enhances the capabilities of the ATM switch, one of the most critical elements in the ATM network     

Hierarchical rule-based and self-organizing fuzzy logic control fordepth of anaesthesia

A multi-stage hierarchical fuzzy control system with a multi-echelon structure for depth of anaesthesia (DOA) is described in this paper. There are four echelons that monitor, control, interpret and assess the whole surgical operation. Echelon 1 is a measurement and control action level that involves: instrument sensing (Dinamap); anaesthetist observations [measurement of sweating (SW), lacrimation (LA) and pupil response (PR)]; and a syringe pump (Graseby pump). Echelon 2 is an interpretation level that involves: interpreting systolic arterial pressure and heart rate to provide the primary DOA; interpreting SW, LA and PR to provide the degree of lightness; and interpreting bolus drug effects to estimate the sensitivity of patients. Echelon 3 is a regulation level that involves: controlling the drug from either a hand-crafted anaesthetists' rule-base or a self-organizing fuzzy logic controller algorithm; planning the drug profile to avoid long recovery; and managing alarm situations. Finally, echelon 4 is an assessment level that assesses the whole surgical procedure according to the patient recovery time. Testing this system in clinical trials as an intelligent adviser has provided a preliminary proof-of-concept of the applicability of this hierarchical structure for DOA management     

Identification, digital control and fuzzy logic techniques applied to a synchronous generator

The experimental results obtained in the design and implementation of an decoupled digital speed and voltage controller for a micro-energy system are reported in this work. The studied system is formed by a 9 Kw DC motor driving a 10 KVA synchronous machine. There are two control loops in the proposed controller: the speed control (speed governor) and the control of the stator's voltage (automatic voltage regulator). Each control loop was designed using linear control techniques and fuzzy control techniques. Tests on the system show the performance of the proposed controllers.     

基于模糊逻辑的智能群体编队移动控制方法

针对群体移动过程中,各个智能体因受力波动较 大,而导致群体运动振荡的问题,提 出了一种基于分布式人工势场法与模糊控制相结合的控制算法。通过分析群体运动过程中单 智能体的受力情况,建立耗散力对移动中振荡进行优化,减小群体移动中的振荡负面影响, 提高群体运动的一致性。建立保持力对编队稳定和保持进行优化,提高编队的稳定性。将优 化过后的合力作为模糊控制器的输入,通过强化学习适应环境变化,调节参数控制输出,实 现群体跟随移动控制。此外,给出了可自动调整大小的多种编队控制生成模型,实现群体编 队移动控制。仿真结果表明能 稳定、有效控制群体跟随移动,编队移动中能有效避障,可使 编队提升移动效率和保持拓扑稳定性。     

基于多值逻辑的高速ECL模糊控制表查询电路

该文指出了硬件实现模糊控制表查询电路存在结构复杂、用数字式实现时设计困难等问题,提出了将模糊控制表转换为多值K图,利用K图从开关级设计模糊控制表查询电路的方法,并用此方法具体设计了一个论域元素个数为5的ECL模糊控制表查询电路。从设计实例看,该文提出的设计方法简单易行,而设计的ECL查询电路具有结构简单和高速推理的优点。     

Type-2 fuzzy logic control of PQoS driven adaptive VoIP scheme

Adaptive VoIP schemes have potentially suboptimal performance owing to imprecision in the metrics used to infer network state. An interval Type-2 fuzzy logic controlled scheme for VoIP services is presented. It infers network state from average delivered perceived quality of service and its degradation due to network congestion and updates an AMR codec mode to match voice quality to available network bandwidth. Tests showed that the scheme maximised delivered voice quality and outperformed an existing adaptive scheme. The scheme achieves robust performance in the presence of input imprecision and can be implemented in VoIP terminals, and the fuzzy rule base is easy to understand and change by non-experts because of its similarity to the human decision-making process.     

基于模糊控制器的异步电机直接转矩控制

为降低传统直接转矩控制(DTC)的转矩脉动,提出了一种基于模糊空间矢量调制的异步电机直接转矩控制方案,该方案将模糊控制技术和空间调制(SVM)技术相结合。模糊控制器的两个输入为转矩误差和误差的变化率,输出为电压矢量的转矩控制分量。为提高控制系统的鲁棒性,采用了基于反电动势的模型参考自适应(MRAS)的无速度估算方法对转子转速进行估算。仿真结果验证了该方案的可行性和有效性。     

Image enhancement with a fuzzy logic approach

An image enhancement technique is presented. The technique first segments the image based on a fuzzy logic function. A generalised median filter (GMF) is then used for the noise suppression and edge preservation in the membership function. The final image is derived with a set of nonlinear grey scale mapping techniques     

Neural network implementation of a fuzzy logic controller

Fuzzy logic is an attractive technique for plant control but suffers from a heavy computation burden. A solution to this problem is proposed here and consists of implementing a fuzzy logic controller in a neural network. The solution is applied to the speed control of a DC motor drive and is validated by experimental results     

A fuzzy logic cooperative MAC for MANET

In both wireless local area networks（WLAN） and mobile ad hoc networks（MANET）, the 1EEE 802.11e medium access control （MAC） protocol is proposed for an effective quality of service （QoS） solution. A number of studies have been done to enhance the performance of 802.11e in MANET by independently adjusting contention window （CW） size of each access category （AC） in every node. However, without the cooperation between the high priority flows and lower priority flows, the QoS goal of high priority flows cannot achieve effectively. In this article, a fuzzy logic based cooperative MAC protocol （FLCMAC） is proposed to cooperate amongst network flows and dynamically adjust access probability of each low priority flow affecting the high priority flows to satisfy their QoS requirement. The simulation results indicate that compared to the enhanced distributed channel access （EDCA） scheme of 802.11e, the FLCMAC consistently excels, in terms of throughput and delay under moderate and heavy background traffic both in single-hop and multi-hop scenarios.     

比例导引原理的三维模糊导引律设计

主要针对三维空间导弹拦截问题,基于比例导引原理设计了三维空间的模糊导引律.首先运用投影的方法将三维导引问题分别投影到两个平面中,将三维空间的运动分解为纵向平面和侧向平面两个平面内的运动.导引律的设计以模糊逻辑推理为基础,运用比例导引原理将竖直视线角速度、水平视线角速度、导弹与飞机的接近速度作为输入量,输出量分别是导弹加速度在oxy(纵向平面)、oxz(侧向平面)平面内的两个分量,模糊分区采用归一化的方法.经仿真验证,模糊导引的脱靶量和加速度均在理想的范围.     

Using fuzzy logic in ATM source traffic control: lessons andperspectives

Due to its capacity to capture human expertise and to formalize approximate reasoning processes, fuzzy logic can be a good answer to the many challenges of congestion control in ATM networks. The authors deal with the application of fuzzy logic to problems of usage parameter control and propose a simple mechanism which, avoiding complex mathematical calculations, guarantees low response times while remaining effective. The flexibility of the fuzzy control proposed is discussed with respect to the probability of facing various types of traffic sources, ranging from bursty to MPEG video     

A unified approach to position and force control by fuzzy logic

This paper proposes a unified control strategy of position and force. The authors' technique is based on impedance control with fuzzy logic and realizes the smooth shift from position control to force control and vice versa. At first, a robust impedance controller based on a disturbance observer is shown, and the method to unify the position and the force control through one controller is described. Next, an algorithm to estimate the dynamic characteristics of the environment is shown, and a force tracking control using the estimated parameters is proposed. Finally, the unified control algorithm of position and force based on fuzzy logic is established. The validity of this method is confirmed by several experimental results