Kinematic Control of Platoons of Autonomous Vehicles

In this paper, an approach to control the motion of a platoon of autonomous vehicles is presented. The proposed technique is based on the definition of suitable task functions that are handled in the framework of singularity-robust task-priority inverse kinematics. The algorithm is implemented by a two-stage control architecture such that intervehicle communication is not required. The effectiveness of the approach is investigated by means of numerical simulation case studies     

Decentralized Fuzzy Control of Multiple Nonholonomic Vehicles

This work considers the problem of controlling multiple nonholonomic vehicles so that they converge to a scent source without colliding with each other. Since the control is to be implemented on a simple 8-bit microcontroller, fuzzy control rules are used to simplify a linear quadratic regulator control design. The inputs to the fuzzy controllers for each vehicle are the noisy direction to the source, the distance to the closest neighbor vehicle, and the direction to the closest vehicle. These directions are discretized into four values: forward, behind, left, and right; and the distance into three values: near, far, and gone. The values of the control at these discrete values are obtained based on the collision-avoidance repulsive forces and an attractive force towards the goal. A fuzzy inference system is used to obtain control values from a small number of discrete input values. Simulation results are provided which demonstrate that the fuzzy control law performs well compared to the exact controller. In fact, the fuzzy controller demonstrates improved robustness to noise.     

Fuzzy Logic Based Approach to Design of Flight Control and Navigation Tasks for Autonomous Unmanned Aerial Vehicles

This paper proposes a fuzzy logic based autonomous navigation controller for UAVs (unmanned aerial vehicles). Three fuzzy logic modules are developed under the main navigation system for the control of the altitude, the speed, and the heading, through which the global position (latitude–longitude) of the air vehicle is controlled. A SID (Standard Instrument Departure) and TACAN (Tactical Air Navigation) approach is used and the performance of the fuzzy based controllers is evaluated with time based diagrams under MATLAB’s standard configuration and the Aerosim Aeronautical Simulation Block Set which provides a complete set of tools for rapid development of detailed six-degree-of-freedom nonlinear generic manned/unmanned aerial vehicle models. The Aerosonde UAV model is used in the simulations in order to demonstrate the performance and the potential of the controllers. Additionally, FlightGear Flight Simulator and GMS aircraft instruments are deployed in order to get visual outputs that aid the designer in the evaluation of the controllers. Despite the simple design procedure, the simulated test flights indicate the capability of the approach in achieving the desired performance.     

Motion Control of Autonomous Vehicles with Guaranteed Prescribed Performance

International Journal of Control, Automation and Systems - In this paper, a novel motion control scheme with guaranteed prescribed performance is proposed for autonomous vehicles with consideration...     

欠驱动自主水面船的非线性路径跟踪控制

基于级联方法提出一种欠驱动自主水面船的全局K指数稳定路径跟踪控制算法.采用以自由路径参考点为原点的Serret-Frenet坐标系建立路径跟踪误差的动态模型,以路径参数的变化率为附加控制输入,克服了以正交投影点为坐标原点时的奇异值问题.设计路径跟踪航向角指令,将路径跟踪模型分解为位置跟踪子系统和航向角、前向速度跟踪子系统两个子系统级联的形式,设计航向角和前向速度的全局指数稳定跟踪控制器,应用级联系统理论证明了路径跟踪误差的全局K指数稳定性.数学仿真和自主水面船湖上实验结果验证了该路径跟踪控制算法的有效性.     

基于模糊规则的液位控制系统

针对过程．工业中的液位控制问题,为弥补常规液位控制方法在应用中的不足,根据液位装置操作的特点,采用模糊控制方法,提出了一种基于模糊规则的液位控制系统。该方法针对影响液位的可测扰动采用前馈控制加以补偿,既避免了在线优化的过程,又增强了系统对随机扰动的鲁棒性,在实际工业应用中取得了理想的控制效果。     

三轴转向车辆侧向稳定性控制策略分析

关于汽车转向稳定性能优化问题,根据三轴转向车辆线性二自由度动力学模型,推导了基于质心零侧偏角控制策略的三轴转向车辆各动力学参数与转向中心纵向位移的关系;结合整车侧向稳定性条件,通过分析转向中心纵向位移对整车侧向稳定性和转向灵活性的影响,得出了转向中心纵向位移临界值和前轮过渡角的表示公式;根据整车侧向稳定性条件和适度质心侧偏角条件,提出了质心零侧偏角调度控制策略;利用MATLAB对质心零侧偏角控制策略和质心零侧偏角调度控制策略进行了定量对比分析,结果证明理论分析的一致性.     

基于蚁群算法的模糊控制规则的过滤简化

针对设计高维模糊控制器过程中会遇到的“规则爆炸”问题,利用蚁群算法进行控制规则的过滤简化。为了用尽量少的规则得到尽可能好的控制效果,利用蚁群算法在饵决组合优化问题中的强大优势,在已有的完备规则中优选出若干条规则嵌人模糊控制器。采用带有时间窗口的蚁群算法去克服遗传算法优选模糊控制规则时可能产生的规则不连续的问题。该文还从遗传算法和蚁群算法工作机制的角度分析了对这两种算法加入约束条件的可操作性。以单级倒立摆控制系统为对象进行仿真研究,最后的仿真结果表明该文方法可以使模糊控制规则具有更好的简化效果和鲁棒性,并能具有好的控制效果。     

Coordinated Control of Networked Vehicles: An Autonomous Underwater System

The specification and design of coordinated control strategies for networked vehicle systems are discussed. The discussion is illustrated with an example of the coordinated operation of two teams of autonomous underwater vehicles collecting data to find the local minimum of a given oceanographic scalar field.     

Effective Turning Motion Control of Internally Actuated Autonomous Underwater Vehicles

This paper presents a novel roll mechanism and an efficient control strategy for internally actuated autonomous underwater vehicles (AUVs). The developed control algorithms are tested on Michigan Tech’s custom research glider, ROUGHIE (Research Oriented Underwater Glider for Hands-on Investigative Engineering), in a controlled environment. The ROUGHIE’s design parameters and operational constraints were driven by its requirement to be man portable, expandable, and maneuverable in shallow water. As an underwater glider, the ROUGHIE is underactuated with direct control of only depth, pitch, and roll. A switching control method is implemented on the ROUGHIE to improve its maneuverability, enabling smooth transitions between different motion patterns. This approach uses multiple feedforward-feedback controllers. Different aspects of the roll mechanism and the effectiveness of the controller on turning motion are discussed based on experimental results. The results illustrate that the ROUGHIE is capable of achieving tight turns with a radius of 2.4 meters in less than 3 meters of water, or one order of magnitude improvement on existing internally actuated platforms. The developed roll mechanism is not specific to underwater gliders and is applicable to all AUVs, especially at lower speeds and in shallower water when external rudder is less effective in maneuvering the vehicle.     

Cooperative Control of Dynamical Systems With Application to Autonomous Vehicles

In this paper, a new framework based on matrix theory is proposed to analyze and design cooperative controls for a group of individual dynamical systems whose outputs are sensed by or communicated to others in an intermittent, dynamically changing, and local manner. In the framework, sensing/communication is described mathematically by a time-varying matrix whose dimension is equal to the number of dynamical systems in the group and whose elements assume piecewise-constant and binary values. Dynamical systems are generally heterogeneous and can be transformed into a canonical form of different, arbitrary, but finite relative degrees. Utilizing a set of new results on augmentation of irreducible matrices and on lower triangulation of reducible matrices, the framework allows a designer to study how a general local-and-output-feedback cooperative control can determine group behaviors of the dynamical systems and to see how changes of sensing/communication would impact the group behaviors over time. A necessary and sufficient condition on convergence of a multiplicative sequence of reducible row-stochastic (diagonally positive) matrices is explicitly derived, and through simple choices of a gain matrix in the cooperative control law, the overall closed-loop system is shown to exhibit cooperative behaviors (such as single group behavior, multiple group behaviors, adaptive cooperative behavior for the group, and cooperative formation including individual behaviors). Examples, including formation control of nonholonomic systems in the chained form, are used to illustrate the proposed framework.     

基于模糊自适应ADRC的全垫升气垫船航向控制

为改善全垫升气垫船航向控制,设计了基于模糊自适应自抗扰控制(ADRC)的全垫升气垫船航向控制器.一方面利用扩张状态观测器估计内、外扰动,并且根据总扰动估计量对系统进行补偿;另一方面利用模糊推理实时优化ADRC控制参数.仿真结果表明,在恶劣环境下基于模糊自适应ADRC的全垫升气垫船航向控制器具有自适应性强,响应速度快,稳定性好等特点.     

基于进化计算的模糊控制规则优化

在改进的遗传算法基础上，提出了模糊控制规则的一种优化方法，模糊规则的优化基于类似最优控制的二次型性能指标，不需要任何被控系统的先验知识，因而适合于一大类复杂非线性系统的控制，仿真结果表明，这种方法是有效的。     

小型无人机数据链与自主飞控系统设计

介绍了小型无人机的组成与总体结构．研究了无人机自主飞行控制系统、数据链、起飞和着陆系统设计方案，采用嵌入式系统和GPS实现了无人机的自主飞行控制和目标自动搜索与识别。     

基于Fuzzy+Smith方案的控制系统设计

对于由两个大惯性及纯滞后组成的被控对象，采用了Fuzzy Smith控制方案，并将其与常用的PID＋Smith控制方法比较，在Siumlink环境下，利用Fuzzy Logic Toolbox对系统进行了仿真，结果表明前一种方案优于后一种方案。     

Fuzzy Logic Based Approach to Design of Autonomous Landing System for Unmanned Aerial Vehicles

This paper is concerned with autonomous flight of UAVs and proposes a fuzzy logic based autonomous flight and landing system controller. Besides three fuzzy logic controllers which are developed for autonomous navigation for UAVs in a previous work as fuzzy logic based autonomous mission control blocks, three more fuzzy logic modules are developed under the main landing system for the control of the horizontal and the vertical positions of the aircraft against the runway under a TACAN (Tactical Air Navigation) approach. The performance of the fuzzy logic based controllers is evaluated using the standard configuration of MATLAB and the Aerosim Aeronautical Simulation Block Set which provides a complete set of tools for rapid development of 6 degree-of-freedom nonlinear generic manned/unmanned aerial vehicle models. Additionally, FlightGear Flight Simulator and GMS aircraft instruments are deployed in order to get visual outputs that aid the designer in evaluating the performance and the potential of the controllers. The simulated test flights on an Aerosonde indicate the capability of the approach in achieving the desired performance despite the simple design procedure.     

基于模糊规则的脉动真空灭菌器的智能控制系统

论文叙述了一种新型医用脉动真空灭菌器的模糊智能控制系统。系统是以ATMEL-89C52单片机为核心并配有高精度、高可靠性的温度、压力传感器及信号放大和V/F转换电路组成,可实现对消毒灭菌全过程的智能监控。利用该系统的智能化软件可方便地实现对脉动真空灭菌器的常规、智能、液体自动化消毒灭菌控制。系统具有实时参数显示、消毒灭菌过程中文提示、消毒灭菌过程参数存储及打印等功能,有完善的参数超限、故障报警和保护功能,同时采取软、硬件抗干扰措施。实验表明系统运行安全、可靠、实用性强。     

A Localization Algorithm for Autonomous Mobile Robots via a Fuzzy Tuned Extended Kalman Filter

The capability to acquire the position and orientation of an autonomous mobile robot is an important element for achieving specific tasks requiring autonomous exploration of the workplace. In this paper, we present a localization method that is based on a fuzzy tuned extended Kalman filter (FT-EKF) without a priori knowledge of the state noise model. The proposed algorithm is employed in a mobile robot equipped with 16 Polaroid sonar sensors and tested in a structured indoor environment. The state noise model is estimated and adapted by a fuzzy rule-based scheme. The proposed algorithm is compared with other EKF localization methods through simulations and experiments. The simulation and experimental studies demonstrate the improved performance of the proposed FT-EKF localization method over those using the conventional EKF algorithm.     

一种基于流水线结构的多级数字混沌编码方案

研究了一种基于流水线结构的多级数字混沌保密通信方案,以驱动参量法作为同步实现模型,并在编码机制上进行了改进。以流水线方式对整个处理过程进行分割,为进程间设定合理的通信粒度,数值模拟得到了另人满意的并行加速比。文章最后对方案中流水线的执行时间进行估算,并分析了在不同任务划分及不同通信速率下的并行加速比情况。