基于PD校正电液速度伺服系统的自适应方法

本文在分析电液速度伺服控制系统特性的基础上,设计一种基于PD校正环节,不需要输出量导数的电液速度伺服系统Narendra 自适应控制方法.分析了电液速度伺服控制系统使用常规的控制方法的动态特性和控制精度;探讨了电液速度伺服控制系统在加入PD校正环节环节后,使系统与参考模型形式一致,达到系统模型是一个严格正实的传递函数,...     

电动平台控制回路校正环节的软件自动计算方法

针对电动平台现有的控制回路校正方法是加超前、滞后环节的试凑法,带有一定的盲目性,耗时、耗人力,且当时象特性较为恶劣、指标要求较高时则根本达不到校正的目的.提出一种利用软件自动计算校正环节的方法,只需输入给定的系统频响指标、交流伺服系统的开环特性,软件会自动给出正确的校正环节.通过对校正环节的离散化,就可以在全数字伺服控制系统中达到系统的指标要求.仿真结果表明了方法的有效性.     

力矩电机调速系统综合实验设计采用的关键技术及应用

力矩电机调速系统综合实验是一个能把基础理论知识、各种实验技能和实验方法加以归纳、分析、相互渗透的一种非常有效的实验形式。本文对该实验中的关键技术展开论述,首先实验测定调速系统的特性,建立未校正系统的模型,再运用MATLAB软件来设计校正环节,并搭建实际电子电路对校正后的特性进行检验。实验结果表明,通过该方法设计的力矩电机调速系统,控制性能良好,其静、动态性能指标均能达到期望目标。     

阵风环境模拟用控制器设计与实验研究

针对环境模拟实验室风环境模拟的阵风特性,设计开发了一种迭代学习自校正PID控制器。该控制器将设定值序列进行迭代学习优化,系统内部采用PID自校正控制策略。仿真和实验结果表明,两种控制方式的结合,可改善系统设定点改变时的动态特性,实现了对期望风环境参数的有效控制。迭代学习控制的作用下,特别是对正弦风的模拟,随着时间推移实际值可跟踪定值,保证了环境模拟的控制精度。     

自适应内模控制方法在磨矿过程中的应用

针对磨矿生产过程中球磨机给矿环节存在的大滞后、大惯性、参数时变等特性,提出了一种增益自适应内模控制方法,将内模控制和对象增益参数辨识算法相结合,通过在线辨识被控对象模型的增益参数,对内模控制器和被控对象模型进行校正,以减少模型参数变化和各种干扰对系统的影响。计算机仿真和实际应用效果均表明,与常规PID控制及IMC控制效果相比,该控制方法对于阶跃响应具有超调小、响应时间快、鲁棒性能好等特点,满足磨矿生产过程对控制器性能的要求,实现了球磨机给矿环节的稳定化控制,为选矿过程综合自动化系统的实施奠定了基础。     

自适应内模控制方法在磨矿过程中的应用

针对磨矿生产过程中球磨机给矿环节存在的大滞后、大惯性、参数时变等特性,提出了一种增益自适应内模控制方法,将内模控制和对象增益参数辨识算法相结合,通过在线辨识被控对象模型的增益参数,对内模控制器和被控时象模型进行校正,以减少模型参数变化和各种干扰对系统的影响.计算机仿真和实际应用效果均表明,与常规PID控制及IMC控制效果相比,该控制方法对于阶跃响应具有超调小、响应时间快、鲁棒性能好等特点,满足磨矿生产过程对控制器性能的要求,实现了球磨机给矿环节的稳定化控制,为选矿过程综合自动化系统的实施奠定了基础.     

硅微Z轴谐振陀螺仪闭环伺服控制系统设计

根据自行设计的硅微Z轴谐振陀螺仪的工作原理,提出了闭环伺服控制系统模型,在对开环检测模型分析的基础上设计了闭环伺服控制系统,并用Matlab软件对闭环伺服系统的频域和时域特性进行了仿真分析,选取了合适的校正环节及优化参数,使系统有较高的稳定裕度和较好的动态特性.通过实验调试实现了初始检测电容差引起的信号以及正交信号的反馈抑制控制,达到了较高的控制精度.     

可移动机器人的运动学模型与控制原理

本文首先对可移动机器人的运动学进行了分析，建立了运动学模型与控制结构图，然后采用时域分析法对此系统进行了校正，最后通过对此系统的仿真与时测实验，对各校正环节的参数进行了整定。     

模糊PID控制的柴油机调速系统仿真

PID控制是生产过程中应用最广泛的控制方式,但它对含变化参数的模型控制效果不理想。为了使舰船柴油机适应不断变化的工作环境,在传统PID控制的柴油机调速系统的基础上加入模糊控制环节,对PID参数进行在线整定。详细介绍了模糊PID算法在柴油机调速系统中的应用以及模糊控制器的设计,并通过MATLAB对模糊PID柴油机调速系统进行仿真,仿真结果表明,模糊自整定PID控制系统可以改善系统的动态特性,减小系统的振荡,提高系统的响应速度。     

PID-DMC算法及其在液位控制系统中的应用

提出了一种新的带PID校正环节的DMC算法，论述了其原理并将其应用于实际液位控制系统，实现了系统在模型失配明显的情况下对二阶液位对象的有效控制。由于控制阀的非线性特性使得本实验中的液位对象具有时滞弱非线性特性，常规DMC算法控制存在明显的模型失配问题并影响了系统的控制性能。为此在常规DMC算法中引入PID环节，从而得到了一种新的PID—DMC算法。实验结果表明该算法能有效改善系统在模型失配情况下的控制性能，且算法简单易行，在线计算量小。     

飞翼布局无人机控制律设计

以某飞翼布局无人机为设计对象,进行内、外回路的控制律设计.在Matlab/Simulink仿真环境下,建立飞翼布局无人机线性小扰动模型,分析纵向、横航向模态特性,根据本体特性缺陷针对性地设计控制律内回路反馈支路及增益,经反馈补偿后的飞行品质满足GJB 185-1986相关要求.在内回路控制律的基础上设计外回路PI控制器...     

Stability constraints of active magnetic bearing control systems

Direct Lyapunov stability method is employed to analyse the closed-loop stability of an electromagnetically suspended rotor system in which non-linearity and singular perturbation nature are embedded. Five explicit sets of stability constraints are proposed so that the state feedback loop is not over-designed. Under impact of modeling inaccuracy, due to neglected higher-order terms, stability conditions for equilibrium point, slow-mode manifold and boundary layer are studied. In addition, the singular perturbation order-reduction technique is used to simplify the feedback loop and reduce the order of a state feedback controller. The stability margin can be numerically evaluated as long as the upper bound of the singular perturbation parameter is available. The proposed state feedback controller is verified by intensive computer simulations such that superior performance in terms of stiffness, rise time and overshoot is illustrated, in comparison to output feedback law and deadbeat control. The reported state feedback loop not only stabilizes the inherently unstable open-loop system, but also preserves the robustness with respect to the parasitic parameter variation and modeling error due to neglected higher-order terms of magnetic control force.     

Robust state feedback control of LTV systems: nonlinear is betterthan linear

Examples of linear control systems with fast time-varying uncertain coefficients are given, which can be stabilized by a nonlinear memoryless state feedback, but cannot be stabilized by a linear time-invariant dynamic state feedback. By means of one of these examples the authors show that the closed loop quadratic stability margin may be infinitely smaller than the actual stability margin     

A double integral quadratic cost and tolerance of feedback nonlinearities

A double integral quadratic cost with an associated integral constraint on state trajectories is shown to result in a stable feedback control law for linear time-varying differential systems. The gain matrix for this control is obtained by integrating a Riccati-type matrix differential equation over a finite time interval and is shown to allow for a large class of nonlinearities in the feedback loop without destroying its asymptotically stable property. The class of nonlinearities is larger than that which is generally permitted for the standard steady-state linear optimal regulator, and a phase margin of 90 ° can be approached by the closed-loop system in the case of time-invarlant systems.     

Analysis and fabrication of a novel MEMS pendulum angular accelerometer with electrostatic actuator feedback

A new type of sensor to directly detect angular acceleration is essential for inertial and control technology. The above interest motivates us to propose a novel micro electromechanical system (MEMS) pendulum angular accelerometer with electrostatic actuator feedback. It adopts a proof pendulum with optimized moment of inertia, suspended to dual anchors by a pair of torsion spring beams, as sensing component. A pair of electrodes are designed as differential capacitors to detect the torsional angular of pendulum, then measure input angular acceleration in sensing axis. Another pair of electrodes are designed as electrostatic actuators for feedback control loop. The structure and operating principle of the MEMS angular accelerometer are introduced. Then, the structure kinetics analysis and signal detecting scheme based on differential capacitors are provided in detail, and the sensitivity and resolution of sensor are derived. Compared with the other MEMS angular accelerometers, the proof pendulum with optimized moment of inertia improves sensitivity and resolution of sensor. The electrostatic actuators feedback loop optimizes the dynamic capability and nonlinearity characteristic. The sensor is fabricated by MEMS fabrication technology. The ANSYS simulation and test results prove the validity of the theoretical analyses. The MEMS angular accelerometer can be used in industrial robots and aircraft by further implementing the signal processing electrocircuit.     

Magnetic actuator design for single-axis micro-gyroscopes

An innovative magnetically levitated system design is presented in this paper. The proof mass, used as the seismic detection components for gyroscopes, is levitated by the presented micro-coil actuator so that the concerns that mechanical fatigue, asymmetry and mis-alignments, which are inevitably present in the traditional mechanical springs design, can be ruled out. In addition, the limited range of dual-axis motion of the proof mass is completely relaxed and therefore the resolution and sensitivity of the gyroscope can be greatly upgraded. That is, the proof mass can be much at higher frequencies and the stroke of the sense-mode motion can be more enlarged, in comparison with the conventional design (i.e., mechanical springs). In addition, self-sensing technique is employed to replace the gap sensors which provide the feedback signal for position regulation of the proof mass, for the sake of cost-down for mass production. A sliding mode control strategy is included to account for the effects of nonlinearity of the maglev system dynamics and hysteresis uncertainty of the micro-coil actuator. The proposed controller is verified by computer simulations and experiments to illustrate its superior capability to stabilize the inherently unstable maglev system and ensure fast response for the lateral position regulation of the seismic proof mass.     

On the Achievable Delay Margin Using LTI Control for Unstable Plants

Handling delays in control systems is difficult and is of long-standing interest. It is well known that, given a finite-dimensional linear time-invariant (FDLTI) plant and controller forming a strictly proper stable feedback connection, closed-loop stability will be maintained under a small delay in the feedback loop, although most closed loop systems become unstable for large delays. One previously unsolved fundamental problem in this context is whether, for a given FDLTI plant, an arbitrarily large delay margin can be achieved using LTI control. Here, we adopt a frequency domain approach and demonstrate that, for a strictly proper real rational plant, there is a uniform upper bound on the delay that can be tolerated when using an LTI controller, if and only if the plant has at least one closed right half plane pole not at the origin. We also give several explicit upper bounds on the achievable delay margin, and, in some special cases, demonstrate that these bounds are tight.     

Control of Nonlinear Systems Using a Self-Organising Neural Network

Two applications of Self Organising Map (SOM) networks in the context of nonlinear control are introduced, one in approximate feedback linearisation and the second in optimal control. It is shown that a modified SOM can be used to approximately Input/Output (I/O) linearise and to control nonlinear systems using a combination of the SOM learning algorithm, and a biologically inspired optimisation algorithm known as chemotaxis. A proof to guarantee the stability of the closed loop during the training of the network and the operation of the whole system is included. The results are illustrated with simulations of a single link manipulator.     

Position‐dependent disturbance rejection using spatial‐based adaptive feedback linearization repetitive control

In this paper, we propose a new design of spatial‐based repetitive control for a class of rotary motion systems operating at variable speeds. The open‐loop system in spatial domain is obtained by reformulating a nonlinear time‐invariant system with respect to angular displacement. A two‐degree‐of‐freedom control structure (comprising two control modules) is then proposed to robustly stabilize the open‐loop system and improve the tracking performance. The first control module applies adaptive feedback linearization with projected parametric update and concentrates on robust stabilization of the closed‐loop system. The second control module introduces a spatial‐based repetitive controller cascaded with a loop‐shaping filter, which not only further reduces the tracking error, but also improves parametric adaptation. The overall control system is robust to model uncertainties of the system and capable of rejecting position‐dependent disturbances under varying process speeds. Stability proof for the overall system is given. A design example with simulation is provided to demonstrate the applicability of the proposed design. Copyright © 2008 John Wiley & Sons, Ltd.     

高速TCP/AQM中的RED算法分析

通过建立适用于高速TCP和AQM反馈控制系统的流体流模型,分析高速TCP/AQM闭环系统的稳定性。采用频域稳定裕度,得到高速TCP/AQM中RED算法的稳定参数区域。基于MATLAB/SIMULINK的仿真结果验证了该方法的有效性。