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时变大时滞神经元自适应预测PID控制器 总被引:3,自引:3,他引:3
本文提出一种克服时变大时滞,扰主被控制过程参数时变的神经自适应预测PID控制算法。该算法利用预测控制克服时滞,利用智能方法优化PID控制器的参数。 相似文献
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为了研究时滞对非线性系统的迭代学习控制收敛性的影响,采用了λ范数和一系列不等式技术,通过建立精确的数学模型,分析了在PD学习律下的Hopfield非线性神经网络系统。在全局Lipschi-tz连续条件下,研究了确保系统跟踪误差收敛的充分条件。理论推导证明时滞对这类非线性系统的迭代学习控制系统的收敛性没有显著的影响,仿真结果表明,迭代学习控制可以实现对非线性时滞系统的精确轨迹跟踪。 相似文献
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一类混合时滞系统的观测器设计 总被引:2,自引:0,他引:2
对于一类具有状态和有限自动机输出时滞的离散混合系统,给出了混合观测器的设计方法。观测器由一个位置观测器和一个离散状态观测器组成。前者应用自动机观测器来确定混合系统的当前位置,后者应用龙伯格观测器对系统离散状态的演化进行估计。对于每一个独立的观测器,系统的信息往往不完全,为了在这种情况下仍能应用混合观测器对系统进行观测,在两类独立观测器的基础上给出了一个新的信号产生器,将两类观测器有机结合起来。同时给出了信号产生器中决策函数的充分条件,进一步得到了整个混合观测器指数收敛的充分条件。保证该混合观测器能在有限步内判断出系统的当前位置,同时指数收敛于真实离散时间状态。最后,给出了仿真例子说明设计方法的可行性和有效性。 相似文献
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本文研究不确定时滞系统的鲁棒镇定问题,在系统状态不能直接测量的情况下,提出了基于观察器的稳定化控制器设计方法. 相似文献
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Practical requirements on the design of control systems, especially process control systems, are usually specified in terms of time-domain response, such as overshoot and rise time, or frequency-domain response, such as resonance peak and stability margin. Although numerous methods have been developed for the design of the proportional-integral-derivative (PID) controller, little work has been done in relation to the quantitative time-domain and frequency-domain responses. In this paper, we study the following problem: Given a nominal stable process with time delay, we design a suboptimal PID controller to achieve the required time-domain response or frequency-domain response for the nominal system or the uncertain system. An H(infinity) PID controller is developed based on optimal control theory and the parameters are derived analytically. Its properties are investigated and compared with that of two developed suboptimal controllers: an H2 PID controller and a Maclaurin PID controller. It is shown that all three controllers can provide the quantitative time-domain and frequency-domain responses. 相似文献
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非线性时滞系统自适应模糊动态面控制 总被引:1,自引:1,他引:0
针对含完全未知时滞的不确定非线性系统的控制问题,提出了一种自适应模糊动态面控制方案.首先采用模糊逻辑系统逼近系统的未知时滞函数,进而用参考信号代换逼近器输入中的未知时滞信号,取消了对未知时滞常作的假设,摆脱了控制器构造对时滞假设条件的依赖性.模糊逼近和时滞代换产生的误差则采用自适应边界技术处理.基于Lyapunov-Krasovskii泛函,证明了闭环系统所有信号半全局一致最终有界,通过调节设计参数可以实现任意的跟踪精度.仿真实例进一步说明了该方案的可行性. 相似文献
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This paper analyzes the fragility issue of fractional-order proportional-integral-derivative controllers applied to integer first-order plus-dead-time processes. In particular, the effects of the variations of the controller parameters on the achieved control system robustness and performance are investigated. Results show that this kind of controllers is more fragile with respect to the standard proportional-integral-derivative controllers and therefore a significant attention should be paid by the user in their tuning. 相似文献
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于标 《工业仪表与自动化装置》2006,(6):9-12
提出了一种大纯滞后系统新预估控制方法,对大纯滞后系统进行了有效的模糊控制.该控制方法与纯滞后时间τ无关,方法简单,易于工程实现,使常规模糊控制在大纯滞后系统的控制中如同对无纯滞后系统的控制一样有效.文中证明了该方法使系统的稳定性与系统的纯滞后无关,并经MATLAB仿真验证,该法具有良好的控制品质,且能适应对象参数和结构有一定变化的时滞系统. 相似文献
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A simple method is proposed to design parallel cascade controllers for open loop unstable processes. A proportional (P)controller is considered for the secondary loop and a proportional integral (PI) controller is considered for the primary loop (P/PI control configuration). Coefficients of the corresponding powers of s (Laplace variable), in the numerator is matched with the coefficients of the corresponding powers of s in the denominator of a closed loop transfer function for a servo problem. Three simulation case studies are considered in this paper. The first case involves a stable secondary loop process and an unstable primary process, the second case involves both unstable primary and secondary processes and the third one, a simulation application to a nonlinear bioreactor model equations. For comparison purposes, P/PI controller design is also carried out by improved simultaneous relay autotuning method, synthesis method and minimizing ISE criterion method. It is found that the proposed method gives a better performance. Robust stability analysis using the complimentary sensitivity function is carried out. The present method is found to be more robust. 相似文献
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Design and implementation of a new fuzzy PID controller for networked control systems 总被引:1,自引:0,他引:1
This paper presents a practical network platform to design and implement a networked-based cascade control system linking a Smar Foundation Fieldbus (FF) controller (DFI-302) and a Siemens programmable logic controller (PLC-S7-315-2DP) through Industrial Ethernet to a laboratory pilot plant. In the presented network configuration, the Smar OPC tag browser and Siemens WinCC OPC Channel provide the communicating interface between the two controllers. The paper investigates the performance of a PID controller implemented in two different possible configurations of FF function block (FB) and networked control system (NCS) via a remote Siemens PLC. In the FB control system implementation, the desired set-point is provided by the Siemens Human-Machine Interface (HMI) software (i.e, WinCC) via an Ethernet Modbus link. While, in the NCS implementation, the cascade loop is realized in remote Siemens PLC station and the final element set-point is sent to the Smar FF station via Ethernet bus. A new fuzzy PID control strategy is then proposed to improve the control performances of the networked-based control systems due to an induced transmission delay degradation effect. The proposed strategy utilizes an innovative idea based on sectionalizing the error signal of the step response into three different functional zones. The supporting philosophy behind these three functional zones is to decompose the desired control objectives in terms of rising time, settling time and steady-state error measures maintained by an appropriate PID-type controller in each zone. Then, fuzzy membership factors are defined to configure the control signal on the basis of the fuzzy weighted PID outputs of all three zones. The obtained results illustrate the effectiveness of the proposed fuzzy PID control scheme in improving the performances of the implemented NCS for different transportation delays. 相似文献
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Tuning PID controllers for higher-order oscillatory systems with improved performance 总被引:1,自引:0,他引:1
In this paper, model based design of PID controllers is proposed for higher-order oscillatory systems. The proposed method has no limitations regarding systems order, time delays and oscillatory behavior. The reduced model is achieved based on third-order modeling and selection of coefficients through the use of frequency responses. The tuning of the PID parameters are obtained from a reduced third-order model; the procedure seems to be simple and effective, and improved performance of the overall system can be achieved. Three simulation examples and one real-time experiment are included to demonstrate the effectiveness and applicability of the proposed method to systems with oscillatory behavior. 相似文献
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One of the reasons of the great success of standard PID controllers is the presence of simple tuning rules, of the automatic tuning feature and of tables that simplify significantly their design. For the fractional order case, some tuning rules have been proposed in the literature. However, they are not general because they are valid only for some model cases. In this paper, a new approach is investigated. The fractional property is not especially imposed by the controller structure but by the closed loop reference model. The resulting controller is fractional but it has a very interesting structure for its implementation. Indeed, the controller can be decomposed into two transfer functions: an integer transfer function which is generally an integer PID controller and a simple fractional filter. 相似文献
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Tuning of PID controllers for boiler-turbine units 总被引:3,自引:0,他引:3
A simple two-by-two model for a boiler-turbine unit is demonstrated in this paper. The model can capture the essential dynamics of a unit. The design of a coordinated controller is discussed based on this model. A PID control structure is derived, and a tuning procedure is proposed. The examples show that the method is easy to apply and can achieve acceptable performance. 相似文献