Control of a man-machine system interacting with the environment

This paper proposes an alternative control algorithm for a mechanical system having direct mechanical interaction with an environment and an operator. A robot for man-robot cooperation, an extender, a human amplifier and a powered steering system are examples of such a system. How to control the interaction in a desirable manner is one of the key issues for such a system. We first model the mechanical system, which has interaction with the environment and the operator, then propose a control algorithm based on the dynamics of the operator and the environment. The proposed control system consists of two controllers: one generates the desired motion of the mechanical system based on the force applied to the system, and the other one controls the interaction between the system and the environment. The proposed control algorithm specifies both the force augmentation and the maneuverability of the system. The algorithm is applied to a planar link mechanism with one degree of freedom. The experimental results illustrate the effectiveness of the proposed control algorithm.     

Simulation of a feedback and adaptive systems

A computer approach for simulating a feedback system and its adaptive versions is presented. It is conceived with recursion formulas to describe the interconnected elements of the system. The potential of the approach is explored by applying it to an existing practical system. It is then enhanced by a performance analysis leading to a provision of a unified system evaluation technique. The approach permitted experimentation with different combination of system parameters, system inputs and system configuration. The efficiency of the approach suggets its suitability for a rational engineering design of systems.     

保有安全性的现场总线喷涂控制系统

由于喷涂具有污染空气、易燃易爆的特点,设计了现线总线喷涂控制系统。它既能减少对外界的污染,又可节约大量的生产成本,最大程度地减少了不安全因素。喷涂现场总线控制系统采用CNA现场总线流量计和阀岛,结合PLC控制器使整个系统安全可靠,具有较高的实用性。设计的现场总线喷涂控制系统结构包括先进的流量控制器、现场总线阀岛和现场总线流量计。由于采用总线传输信号,系统安全可靠,具有防爆的特点,该系统已在手机喷涂中得到应用。     

Tuning of Gaussian stochastic control systems

A closed-loop system consisting of a control system and an adaptive controller is called tuning for a specified control objective if the real system and the ideal system defined below achieve the same value for the control objective. The real system is the system consisting of the unknown control system in closed loop with the adaptive controller in which the parameters of the adaptive controller have been determined by identification under feedback or in closed loop. The ideal system is the system consisting of the unknown control system in closed loop with a controller in which the controller has been synthesized with knowledge of the unknown control system and such that the closed-loop system satisfies the control objective. Both the Gaussian stochastic control system with full observations and with partial observations are considered. The approach to the problem is based on stochastic realization theory for Gaussian systems. The control objectives of minimum variance control and pole placement are also given. Necessary conditions for tuning are discussed     

Advanced material handling system for computer integrated manufacturing

A cordless linear synchronous motor (LSM) material handling system for CIM has been developed. The system incorporates a courier that moves without tether restrictions. This provides for an automated material handling system with improved travel and flexibility. The material handling system runs on an integrated reverse air bearing system which eliminates friction and backlash. The proposed system forms part of a manufacturing assembly, interacting with overhead manipulators and part feeders to form a comprehensive production system. The design and implementation of the cordless linear motor material handling system (MHS) is outlined and described in the paper.     

电厂燃料管理系统解决方案

电厂燃料管理系统的开发目标是建立一套完整、科学的燃料计算机管理体系,通过此系统的建立达到信息传递快捷准确,各部门沟通协调融洽的目的,提高燃煤数据对生产经营决策的支持能力,从而降低生产成本。整个系统从煤炭进厂、称重、卸煤验收、煤样制备、入厂煤化验、入厂煤电算化结算和数据统计发布整个过程进行管理。方便各级管理人员对煤的各种数据指标进行查阅、统计。采用C/S模式对整个系统进行了设计和开发,实现了燃料的全过程计算机管理,提高了工作率,为电厂逐步实现网络化奠定了良好的基础。     

A ball and beam tracking and balance control using magnetic suspension actuators

A new ball and beam system is constructed using a pair of magnetic suspension actuators in this paper. The proposed system can be used not only as a control theory verification and practice platform, but also as an educational demonstration and training tool for system integration of electrics, mechanics and cybernetics. The proposed control system activates two magnetic suspension actuators on either side of the beam. The magnetic force, as a function of position and coil current, was measured and modelled by a quadratic function. The system mathematical model is derived by the Lagrangian function. For control performance, a single chip microprocessor as control kernel with basic electronic components is designed and implemented. The ball and beam system hardware as well as microprocessor-based control circuit is implemented and tested. The static and dynamic performance of the ball and beam system is tested with several different scenarios. The system operation on oscillatory stabilization and sinusoidal tracking is verified with excellent operational characteristics.     

Complete calming and stabilization of delay systems using spectral reduction

Spectrally controllable autonomous system with commensurable delays is reduced to a system with finite spectrum. For the spectrally reduced system, a state feedback is constructed such that it ensures complete calming of the original system and stability of the closed-loop system. The distributed delay in the closed-loop system can be only in one variable. The results are illustrated by an example.     

Generation of grid multi-wing chaotic attractors and its application in video secure communication system

In order to study the application of chaos in video image encryption, a real-time video secure communication system based on a new grid multi-wing chaotic system is proposed in this paper. First, by introducing sawtooth wave functions to the Lorenz system, a new grid multi-wing butterfly chaotic system with complicated dynamical behaviors is obtained. Compared with the existing multi-scroll and multi-wing chaotic systems, The system structure is simple and more easier to be implemented in a digital system. Then, a chaos-based pseudorandom random number generator is developed by implementing post-processing procedure. The present video secure communication system is designed with the closed-loop feedback scheme. The corresponding hardware implementation is developed by FPGA platforms, and the experimental results are given to verify its feasibility. Furthermore, a series of widely used secure analyses are applied to prove that the system has good security performance.

     

Adaptive control of left ventricular bypass assist devices

This paper presents a computer-based adaptive control system for left ventricular bypass assist devices consisting of air driven diaphragm pumps. The system provides for 1) synchronization of pumping with ECG signals and 2) control of atrial pressure at desired levels. The system design includes an adaptive control algorithm which is a self-tuning PID-controller based on pole placement. The performance of the system has been demonstrated by in vitro experiments_ on a mock circulatory system. When there is an increase in atrial pressure, the system responds with an increase in stroke volume. Following major changes in the circulatory system, the control algorithm retunes itself and restores the system to the desired state.     

A granularity model for balancing the structural complexity of manufacturing systems equipment and layout

The structural complexity of a manufacturing system results primarily from the complexity of its equipment and their layout. The balance between both complexity sources can be achieved by searching for the best system granularity level, which yields a manufacturing system with the least overall structural complexity. A new system granularity complexity index is developed to sum up and normalize the complexity resulting from the system layout complexity and the equipment structural complexity. A previously developed layout complexity index together with a code-based structural complexity assessment are used to determine the structural complexity of standalone pieces of equipment and to arrive at a balance between the two sources of complexity. Cladistics analysis is used to hierarchically cluster required pieces of equipment and bundle them into more integrated equipment and machines and demonstrate the possible different system granularity levels. The new developed model is a useful tool to create specific system configuration and layout alternatives based on system components adjacency, and then select the system design with the least overall structural complexity among those alternatives. The results of the presented case study clearly demonstrated this trade-off where decomposing manufacturing systems into a highly granular configuration with standalone machines maximizes system layout complexity and minimizes equipment complexity, while at a low level of granularity pieces of equipment are bundled into complex integrated machines, lines or cells but with a very simple system layout.     

Expert system for integrated plant protection in pepper (Capsicum annuun L.)

An expert system was developed with the aim of improving decision-making by pepper growers. Knowledge was obtained from the literature and from the experts. The knowledge was then represented in the knowledge base of the expert system in a series of IF–THEN rules. The system is supported by a data base containing information for the identification of 11 weeds, 20 insects, 14 diseases, three abiotic factors and control measures. The system is enhanced with 87 photos and drawings that assist the used in the identification process and choosing control measures. The expert system was evaluated with technicians and students. According to the validation results the system was considered very satisfactory with an average rank of 9.15 by technicians and of 8.95 by students with a statistic mode ranking 10 in all the cases. The program can be used as a decision tool for farmers and technicians and for educational purposes.     

汽车线控转向系统的建模与仿真研究

研究汽车转向稳定性控制问题。针对线控转向系统的可变转向特性对汽车操纵影响稳定性,为保证行驶安全性,通过分析线控转向系统的工作原理和结构特点,建立线控转向系统各组成部分的数学模型,结合驾驶员模型和整车模型,对线控转向系统的可变角传递特性和力传递特性进行仿真。仿真结果表明:SBW系统能够获得与传统转向系统同样清晰的路感,并且SBW系统能够保持稳定的转向灵敏度,从而改善了汽车的稳定性,为保证行驶的安全提供了依据。     

On improvement of transient performance in tracking control for a class of nonlinear systems with input saturation

This paper studies the technique of the composite nonlinear feedback (CNF) control for a class of cascade nonlinear systems with input saturation. The objective of this paper is to improve the transient performance of the closed-loop system by designing a CNF control law such that the output of the system tracks a step input rapidly with small overshoot and at the same time maintains the stability of the whole cascade system. The CNF control law consists of a linear feedback control law and a nonlinear feedback control law. The linear feedback law is designed to yield a closed-loop system with a small damping ratio for a quick response, while the nonlinear feedback law is used to increase the damping ratio of the closed-loop system when the system output approaches the target reference to reduce the overshoot. The result has been successfully demonstrated by numerical and application examples including a flight control system for a fighter aircraft.     

Stabilization of the Euler–Bernoulli equation via boundary connection with heat equation

In this paper, we are concerned with the stabilization of a coupled system of Euler–Bernoulli beam or plate with heat equation, where the heat equation (or vice versa the beam equation) is considered as the controller of the whole system. The dissipative damping is produced in the heat equation via the boundary connections only. The one-dimensional problem is thoroughly studied by Riesz basis approach: The closed-loop system is showed to be a Riesz spectral system and the spectrum-determined growth condition holds. As the consequences, the boundary connections with dissipation only in heat equation can stabilize exponentially the whole system, and the solution of the system has the Gevrey regularity. The exponential stability is proved for a two dimensional system with additional dissipation in the boundary of the plate part. The study gives rise to a different design in control of distributed parameter systems through weak connections with subsystems where the controls are imposed.     

基于MVC模式的桥梁处治专家系统研究

专家系统(Expert system简称ES)是模拟人类专家解决问题的智能程序系统。专家系统的主要特征是有一个巨大的知识库,存储着某个专门领域的知识。在解决问题时,用户为系统提供一些已知数据,然后从系统中获得专家水平的结论[1-2]。目前专家系统已经应用到生活中的各个方面,本文着重研究了专家系统在在役桥梁中的应用,并且给出了模型建立方法、系统设计以及专家系统软件的设计流程[3]。最后将该系统应用到具体的实例中,实验证明在役桥梁专家决策系统具有良好的效果[4]。     

Application of an approximate time delay to a Posicast control system†

The performance of a method of producing relatively long time delays, using truncated Fourier series expansion, applied to a Posicast control system was investigated. The controlled system had a long natural period and was lightly damped. Both the Posicast control and the system were simulated on an analogue computer.

The response of the system to step inputs with Posicast showed dramatic improvement over the uncompensated system. The overall system approached the theoretical response of an ideal Posicast system. A series of runs was made with successively cruder approximations of the delay function. Response was not seriously degraded until the frequency of the truncated terms became comparable to the upper 3 dB frequency of the controlled system.

Other waveforms were tested, including sine, square, sawtooth and quasi-random signals. In all cases, the performance of the system was well behaved. The approximate method of delay, therefore, offers a means of implementing Posicast control with systems requiring relatively long delays of continuously variable inputs.     

Projection operator-based robust adaptive control of an aerial robot with a manipulator

This paper describes a quadcopter manipulator system, an aerial robot with an extended workspace, its controller design, and experimental validation. The aerial robot is based on a quadcopter with a three degree of freedom robotic arm connected to the base of the vehicle. The work aims to create a stable airborne robot with a robotic arm that can work above and below the airframe, regardless of where the arm is attached. Integrating a robotic arm into an underactuated, unstable system like a quadcopter can enhance the vehicle's functionality while increasing instability. To execute a mission with accuracy and reliability during a real-time task, the system must overcome the inter-coupling effects and external disturbances. This work presents a novel design for a robust adaptive feedback linearization controller with a model reference adaptive controller and hardware implementation of the quadcopter manipulator system with plant uncertainties. The closed-loop stability of the aerial robot and the tracking error convergence with the robust controller is analyzed using Lyapunov stability analysis. The quadcopter manipulator system is custom developed in the lab with an off-the-shelf quadcopter and a 3D-printed robotic arm. The robotic system architecture is implemented using a Jetson Nano companion computer for autonomous onboard flight. Experiments were conducted on quadcopter manipulator system to evaluate the autonomous aerial robot's stability and trajectory tracking with the proposed controller.     

Component-based robot system design for grasping tasks

The paper presents a robot system design with highly reusable components for a component-based robot system for manipulation tasks. The robot system is designed based on the analysis of manipulation tasks using a unified modeling language use case diagram. For a service robot with locomotion and manipulation mechanisms, reusability of robot system components is improved by adopting the proposed design. Our structure consists of scenario, task, robot information management server, data analyzer, sensor hardware controller, skill, and motion hardware controller on a component-based robot system. Based on the proposed robot system, we implemented a component-based robot system and subsequently realized a grasping motion by a service robot.     

基于LS-SVM逆模型的青霉素发酵软测量方法

针对青霉素发酵过程中的某些关键生物参数(如菌体浓度、基质浓度、产物浓度)难以实时在线测量的问题,提出一种基于最小二乘支持向量机(LS-SVM)逆模型的软测量方法。该方法用具有高斯核函数的LS-SVM,离线建立被测对象的静态非线性逆模型。由静态非线性逆模型外加若干表征非线性动态特征微分器,构成了非线性系统的逆系统,将此逆系统串联在原发酵系统之后,得到"线性化"的伪线性系统。仿真结果表明,该方法能够对青霉素发酵过程中不可在线测量的关键变量进行预测,且达到了较高的测量精度。