基于模糊感觉强度的无规则模糊逻辑系统的仿真设计

基于模糊逻辑方法在心理语言学研究领域的有效性,该文提出基于模糊感知强度和韦伯定律的一类新的无规则模糊逻辑系统及其自适应控制应用的方法。首先,应用心理物理学中的概念,模糊逻辑系统的知识库是利用模糊感觉强度来描述专家经验感受;模糊推理后应用广义韦伯定律进行解模糊得到系统输出。然后,针对一类非线性系统,利用构造的新的无规则模糊逻辑系统进行自适应控制设计,得到相应的控制器和参数自适应律。最后,通过Duffing混沌系统仿真算例验证了该文方法的可行性和有效性。     

Loopus opens a new dimension in satellite communications

Without any doubt the geostationary orbit is for many applications the most suitable orbit because of the apparent standstill of its satellites. Unfortunately geostationary satellites cannot illuminate the polar regions and furthermore the number of orbit positions is limited. With satellites on certain, dependent on the system, circular or elliptical orbits inclined against the equatorial plane, it is possible to form, off the geostationary orbit, loop-shaped quasi-positions—referred to as Loopus positions—which are served by satellites of alternate identity. The basic idea is to employ in shift several satellites along the same apparent track which, in the alternate play with the earth's rotation, form small loops at the celestial sphere. Change-over takes place at the loop intersection point where a collision of the two satellites is just avoided. Thus a system with for example three satellites, which serve two Loopus positions, allows uninterrupted (quasi-)stationary communication via earth-stations in two coverage zones.     

同步轨道共位卫星位置确定技术

同步轨道卫星共位是指在一个地球同步轨道±0．1°的窗口上放置两颗或两颗以上的卫星。文中介绍了同步轨道卫星多星共位的必要性和连接端站干涉测量的原理。对同步轨道共位卫星位置测量精度进行分析,得出结论,连接端站干涉测量技术能够满足同步轨道共位卫星位置测量的要求。     

模糊控制器专用集成电路的设计与实现

提出了一种用数字逻辑电路设计模糊控制器的方法。该模糊控制器电路不用ＣＰＵ，全部算法由数字逻辑电路实现，具有运算速度快的特点，适合于需要高速控制的场合。该模糊控制器电路具有被激活的规则自动生成功能，不需要大规模的ＲＡＭ或ＲＯＭ存储模糊规则，电路规模小，易于实现，特别适合于输出控制量为离散值的应用场合。已在一片ＦＰＧＡＸｉｌｉｎｘ４０１０ＰＧ１９１－６上实现了该模糊控制器电路，并成功地应用于温控系统。     

Satellite constellation design for 5G wireless networks of mobile communications

Satellite constellation design plays an important role in satellite networks. Network constellation system design can affect the effectiveness of current improvements of the communications link and the management of the entire network. The power requirement of the mobile stations and ground stations is very high in a geostationary Earth orbit communication system, which means the terrestrial terminal is hard to be made handheld for fifth generation mobile communications. The emergence of nongeostationary orbit satellites such as low Earth orbit satellites greatly compensates for the disadvantage of geostationary Earth orbit satellites. Based on the classical constellation design method, the orthogonal circular orbit constellation is proposed. The design objectives considered here are the following: global Earth coverage by low Earth orbit satellites, the duration of continuously covering one mobile station by one satellite is more than 9.57 min, the access satellite link duration time of the mobile station is more than 4.79 min, and the number of satellites and orbits is to be minimum.     

Autonomous navigation of service spacecrafts on geostationary orbit using GNSS signals

In this paper we consider the possibilities of navigation of spacecrafts designed to service artificial Earth satellites on the geostationary orbit and of space debris removal in the near-Earth space using the signals of Global Navigation Satellite Systems. We have formulated the methodology for estimation of the signals availability of navigation satellites on the geostationary orbit through the utilization of almanac of GPS and GLONASS. It has been demonstrated that in the case of reception of navigation signals, which are radiated by the antenna system within the limits of main lobe of the radiation pattern (RP), the availability of satellite navigation signals on the geostationary orbit is very low even if we utilize GPS and GLONASS simultaneously. We present the simulation results of the received on the geostationary orbit navigation satellites using the signals radiated in the main lobes in the range from ±13.8 to ±23.5° for the L1 frequency, from ±13.8 to ±26° for the L2/L5 frequencies and in the side lobes in the range from ±30 to ±60° of RP of the satellite antennas. The simulation of the navigation satellites available on the geostationary orbit is given on the 24-hour time interval. Presented results are illustrated by the calculations of number of visible satellites and by the geometric factor.     

Evolutionary algorithms for fuzzy control system design

This paper provides an overview on evolutionary learning methods for the automated design and optimization of fuzzy logic controllers. In a genetic tuning process, an evolutionary algorithm adjusts the membership functions or scaling factors of a predefined fuzzy controller based on a performance index that specifies the desired control behavior. Genetic learning processes deal with the automated design of the fuzzy rule base. Their objective is to generate a set of fuzzy if-then rules that establishes the appropriate mapping from input states to control actions. We describe two applications of genetic-fuzzy systems in detail: an evolution strategy that tunes the scaling and membership functions of a fuzzy cart-pole balancing controller and a genetic algorithm that learns the fuzzy control rules for an obstacle-avoidance behavior of a mobile robot     

欧洲下一代气象卫星及其红外遥感仪器概要

总结了欧洲气象卫星组织（EUMETSAT）与欧空局（ESA）的气象卫星发展情况以及他们对下一代地球同步轨道和极轨气象卫星的规划.下一代地球同步轨道气象卫星计划为MTG系列,将以MTG-I（成像卫星）和MTG-S（探测卫星）双星运行,各自承载不同的探测仪器,计划发射6颗卫星（4颗MTG-I和2颗MTG-S）.而极轨气象卫星MetOp-SG则与美国国家海洋和大气管理局（NOAA）/美国航空航天局（NASA）的卫星系统联合.ESA当前的MetOp卫星和下一代MetOp-SG卫星在“上午”轨道上运行,NOAA/NASA的下一代JPSS卫星在“下午”轨道上运行,双方共享两个轨道卫星数据.     

Analog Circuit Implementation of a Variable Universe Adaptive Fuzzy Logic Controller

A novel analog integrated circuit implementation of an adaptive fuzzy logic controller (AFLC), called variable universe fuzzy logic controller (VFLC), is presented which has not been reported before. The VFLC is a stable controller which has fewer on-line adapting parameters than the conventional AFLCs based on adapting fuzzy rules, thus it is more suitable for hardware implementation. The input and output universes of discourse of the VFLC are adaptively changed according to the input variables to improve the control effect. A novel peaky-triangle membership function is presented to realize the complex input universe variation. The absolute value of the integral of the input variables is used for the output universe variation, and then it is multiplied with the output of the conventional fuzzy logic controller to form the final output. The other parts are minimization circuits and a center of gravity defuzzification circuit that does not use a division circuit. An analog VFLC with 2 inputs, 1 output, and 9 rules is designed and fabricated using a 0.6-$mu$ m CMOS standard technology. It can work either in a non-adaptive or an adaptive mode. The measurements show that it completes the VFLC functions.      

Fuzzy neural control of voice cells in ATM networks

This paper presents the design of a fuzzy controller for managing cells generated by voice sources in asynchronous transfer mode (ATM) networks. Typical voice cells, characterized by a high degree of burstiness, complicate any attempt to use classical control theory in the design of an ATM cell rate controller. The fuzzy control approach presented in this paper overcomes this limitation by appealing to the linguistic ability of fuzzy set theory and logic to handle the complexity. Specifically, the cell rate control problem is linguistically stated but treated mathematically via fuzzy set manipulation. In particular, the ATM voice cell controller being proposed is an improved and intelligent implementation of the leaky bucket cell rate control mechanism extensively studied in the literature. This intelligent implementation of the leaky bucket mechanism uses a channel utilization feedback via the QoS parameters to improve its performance. This ATM fuzzy controller takes the form of an organized set of linguistic rules quantitatively expressed and manipulated by means of fuzzy set theory and fuzzy logic. The fuzzy control rules are stored in fuzzy associative memory to permit parallel executions     

Learning of Hybrid Fuzzy Controller for the Optical Data Storage Device

A hybrid track-seeking fuzzy controller for an optical disk drive (ODD) is proposed in this paper. The proposed hybrid fuzzy controller (HFC) smoothes the voltage applied to the sled motor and improves the track-seeking efficiency. The HFC consists of two subsystems including an intelligent time switch and a driving force controller. Both subsystems are designed based on fuzzy logic inferences. The main functions of the proposed HFC are to drive the optical head unit (OHU) to the target track neighborhood as fast as possible and smoothly park the OHU in the least time in the target track neighborhood. An automatic learning approach based on genetic algorithms (GAs) is proposed for learning the fuzzy rules for both the intelligent time switch and driving force controller. Modulated orthogonal membership functions are utilized in both fuzzy controllers to improve the GA learning efficiency. The number of parameters needed to parameterize the fuzzy rule base is greatly reduced with the modulated orthogonal membership functions. Compared to the conventional track-seeking controller currently utilized in most ODDs that employ a speed profile as the reference signal for the track-seeking feedback control system, the proposed HFC outperforms the conventional track-seeking control schemes. Experiments are performed to justify the performance comparison.     

The Evolution of the Geostationary Platfom Concept

The paper will review the conceptual development over the last decade of the use of very large spacecraft, i.e., "platforms," in geostationary orbit. Geostationary platforms were originally conceived as an efficient means of increasing the capacity at a point in the geostationary orbital arc. This geostationary platform was seen as a solution to the predicted crowding of the orbital arc since it could provide the functions of many individual satellites of conventional design. Also, geostationary platforms have been suggested for mounting very large antennas as will be required for mobile communications, or high power sources as will be required for broadcast services to small terminals. More recently these "large satellite" platforms were also envisioned as including earth observation and other science payloads. The advent of the Space Station which can provide a staging base for platform assembly and test in space at low earth orbit (LEO), prior to launch to geostationary earth orbit (GEO), will introduce a new dimension to practical platform design. This dimension has reintroduced the geostationary platform concept as a potential communications and science spacecraft of the post-IOC-Space Station family. This paper describes the evolution of concepts for geostationary platforms over the last decade based on both communications and science user scenarios developed worldwide.     

Lyapunov-function-based design of fuzzy logic controllers and itsapplication on combining controllers

This paper presents the design of fuzzy logic controllers (FLCs) for nonlinear systems with guaranteed closed-loop stability and its application on combining controllers. The design is based on heuristic fuzzy rules. Although each rule in the FLC refers to a stable closed-loop subsystem, the overall system stability cannot be guaranteed when all these rules are applied together. In this paper, it is proved that if each subsystem is stable in the sense of Lyapunov (ISL) under a common Lyapunov function, the overall system is also stable ISL. Since no fuzzy plant model is involved, the number of subsystems generated is relatively small, and the common Lyapunov function can be found more easily. To probe further, an application of this design approach to an inverted pendulum system that combines a sliding-mode controller (SMC) and a state feedback controller (SFC) is reported. Each rule in this FLC has an SMC or an SFC in the consequent part. The role of the FLC is to schedule the final control under different antecedents. The stability of the whole system is guaranteed by the proposed design approach. More importantly, the controller thus designed can keep the advantages and remove the disadvantages of the two conventional controllers     

Launcher without a country [marine satellite launch platform]

The author describes how an international team of marine and rocket engineers is combining advanced oil platform technology with a Cold War rocket system into a novel means of launching satellites at sea. The objective is to heave telecommunications satellites from the equator, the best launch latitude on the planet, into geostationary orbit, the most marketable territory in space. The paper details how marrying an agile Soviet rocket design with the best oil platform technology may provide an altogether new means of getting big satellites into orbit     

A method for improving the robustness of PID control

In this paper, an effective method is proposed for robust proportional-integral-derivative (PID) control that is easily implementable on commonly used equipment such as programmable logic controller (PLC) and programmable automation controller (PAC). The method is based on a two-loop model following control (MFC) system containing a nominal model of the controlled plant and two PID controllers. Basic features exhibited by the MFC structure are presented, and a technique to tune both component controllers is given. The proposed structures have been implemented in a programmable logic controller and tested on control plants with perturbed parameters. Also, the proposed control system has been checked for its performance in cases when the operation of PID controllers is based on fuzzy logic. Tuning rules for the fuzzy controllers in the presented MFC system have been proposed. Results of tests lend support to the view that the proposed control structures may find wide application to robust control of plants with time-varying parameters.     

DC/DC变换器自适应模糊逻辑控制器设计

文章为DC/DC变换器设计了一种自适应模糊逻辑控制器（AFLC）。所提出的AFLC不需要专家系统提供决策参数和控制规则,而是使用模型数据文件来产生参数和规则,该模型数据文件包含输入输出对的整体概况。所提出的控制器使用8位微控制器来实现降压、升压和降压-升压变换器。     

A fuzzy logic sliding mode controlled electronic differential for a direct wheel drive EV

In this study, a direct wheel drive electric vehicle based on an electronic differential system with a fuzzy logic sliding mode controller (FLSMC) is studied. The conventional sliding surface is modified using a fuzzy rule base to obtain fuzzy dynamic sliding surfaces by changing its slopes using the global error and its derivative in a fuzzy logic inference system. The controller is compared with proportional–integral–derivative (PID) and sliding mode controllers (SMCs), which are usually preferred to be used in industry. The proposed controller provides robustness and flexibility to direct wheel drive electric vehicles. The fuzzy logic sliding mode controller, electronic differential system and the overall electrical vehicle mechanism are modelled and digitally simulated by using the Matlab software. Simulation results show that the system with FLSMC has better efficiency and performance compared to those of PID and SMCs.     

A stable self-organizing fuzzy controller for robotic motioncontrol

It is well known that robotic manipulators are highly nonlinear coupling dynamic systems. It is difficult to establish an appropriate mathematical model for the design of a model-based controller. Although fuzzy logic control has a model-free feature, it still needs time-consuming work for the rules bank and fuzzy parameters adjustment. In this paper, a stable self-organizing fuzzy controller (SOFC) is proposed to manipulate the motion trajectory of a 5-degrees-of-freedom robot. This approach has a learning ability for responding to the time-varying characteristic of a robot. Its control rules bank can be established and modified continuously by online learning with zero initial fuzzy rules. In addition, this control strategy has effectively improved the stability problem of a previous SOFC. The experimental results show that this intelligent controller has a stable learning ability and good motion control capability     

Comparison of the applicability of rule-based and self-organizing fuzzy logic controllers for sedation control of intracranial pressure pattern in a neurosurgical intensive care unit

This paper assesses the controller performance of a self-organizing fuzzy logic controller (SOFLC) in comparison with a routine clinical rule-base controller (RBC) for sedation control of intracranial pressure (ICP) pattern. Eleven patients with severe head injury undergoing different neurosurgeries in a neurosurgical intensive care unit (NICU) were divided into two groups. In all cases the sedation control periods lasted 1 h and assessments of propofol infusion rates were made at a frequency of once per 30 s. In the control group of 10 cases selected from 5 patients, a RBC was used, and in the experimental group of 10 cases selected from 6 patients, a self-organizing fuzzy logic controller was used. A SOFLC was derived from a fuzzy logic controller and allowed to generate new rules via self-learning beyond the initial fuzzy rule-base obtained from experts (i.e., neurosurgeons). The performance of the controllers was analyzed using the ICP pattern of sedation for 1 h of control. The results show that a SOFLC can provide a more stable ICP pattern by administering more propofol and changing the rate of delivery more often when rule-base modifications have been considered.     

On the Relationship Between Geostationary Orbit Capacity and the Interference Allowance

With the increasing demands being placed upon the geostationary orbit/spectrum resource, there is a need to consider the impact of increasing the intersatellite interference allowance. By increasing the intererence allowance, more satellites can be placed along the geostationary orbit. However, as a result, an individual sateilite's capacity will be reduced. This paper examines the tradeoff between intersatellite interference and total orbit capacity for both digital and analog modulation methods.