永磁交流伺服系统速度控制器优化设计方法

针对永磁同步电机数字控制系统中,电机转速动态过程中出现的由于通常采用PI控制器串联校正来设计速度环而导致的超调和振荡问题,提出了一种速度控制器优化设计方法.在分析了永磁交流伺服系统速度环数学模型的基础上,调整了速度控制器中比例增益的作用位置,构成IP控制器局部反馈校正来设计速度环.根据稳定性和跟随性要求,选取转速偏差指标函数,优化控制器参数设计,同时在控制器设计中增加了anti - windup策略.所设计的控制器,可以获得电机转速的无超调、无振荡快速响应,并具有较强的抗扰动能力.仿真和实验结果验证了设计方法的有效性和可行性.     

An anti-windup scheme for multivariable nonlinear systems

In this paper, an approach to control synthesis for constrained multivariable nonlinear systems using feedback linearization is described. The synthesis of a multivariable saturation element which preserves the directionality of the input vector and produces control action which upholds constraints within the original coordinate system is discussed. Nominal stability analysis is performed using nonlinear μ-analysis for a restricted region of the state-space. A set of conditions is obtained which defines the region of the state space over which the stability analysis is applicable. The results are applied to both a numerical example and to a multivariable polymerization reactor model.     

Robust performance for an energy sensitive wireless body area network – an anti-windup approach

This paper applies a robust anti-windup (AW) based control scheme to optimise throughput rate for an 802.15.4 wireless body area network (WBAN) that is subject to naturally occurring input saturation constraints. The technique uses an intuitively appealing two step design procedure. Firstly, a robust H_∞ loop-shaping linear controller is designed providing nominal (un-saturated) robust performance. Then Weston–Postlethwaite AW compensation techniques are used to minimise the adverse effects of any control input non-linearities on closed loop performance. The methodology provides guaranteed quality of service (in this context taken to mean that sufficient data is always available to reassemble the required biometric waveforms, e.g. ECG) while concurrently minimising power consumption over an extended usage period. This joint robust performance question is validated on an experimental mote based 802.15.4 wireless sensor network.     

Linear discrete-time global and regional anti-windup: an LMI approach

In this article we address linear anti-windup design for linear discrete-time control systems guaranteeing regional and global stability and performance. The techniques that we develop are the discrete-time counterpart of existing techniques for anti-windup augmentation which lead to convex constructions by way of linear matrix inequalities (LMIs) when adopting static and plant order anti-windup augmentation. Interesting system theoretic interpretations of the performance bounds for the non-linear closed loop can also be given. We show here that parallel results apply to the discrete-time case. We derive the corresponding conditions and prove their effectiveness by adapting the continuous-time approaches to the discrete-time case.     

采用条件技术设计AIMC结构的抗饱和控制器

AIMC(Anti-windup IMC)结构是内模控制与扰动观测器相结合的抗饱和控制结构,为了有效地解决AIMC结构中的抗饱和控制器的设计问题,提出了采用条件技术设计AIMC结构中的抗饱和控制器的方法。分析了AIMC结构是一种二自由度的新型IMC结构,能够同时解决扰动及饱和问题。通过引入条件技术的可行性参考输入的概念,给出了抗饱和控制器的设计方法。给出了运用该方法的一个仿真实例,仿真结果表明所设计的系统具有良好的抗饱和性能及抗扰动性能。采用条件技术设计AIMC结构中的抗饱和控制器,计算简便,在没有引入新的不确定参数的条件下改善了系统的整体性能。该方法是一种很有实际价值的抗饱和控制器的设计方法。     

Time-response shaping using output to input saturation transformation

For linear systems, the control law design is often performed so that the resulting closed loop meets specific frequency-domain requirements. However, in many cases, it may be observed that the obtained controller does not enforce time-domain requirements amongst which the objective of keeping a scalar output variable in a given interval. In this article, a transformation is proposed to convert prescribed bounds on an output variable into time-varying saturations on the synthesised linear scalar control law. This transformation uses some well-chosen time-varying coefficients so that the resulting time-varying saturation bounds do not overlap in the presence of disturbances. Using an anti-windup approach, it is obtained that the origin of the resulting closed loop is globally asymptotically stable and that the constrained output variable satisfies the time-domain constraints in the presence of an unknown finite-energy-bounded disturbance. An application to a linear ball and beam model is presented.     

Observer-based perturbation extremum seeking control with input constraints for direct-contact membrane distillation process

An observer-based perturbation extremum seeking control is proposed for a direct-contact membrane distillation (DCMD) process. The process is described with a dynamic model that is based on a 2D advection-diffusion equation model which has pump flow rates as process inputs. The objective of the controller is to optimise the trade-off between the permeate mass flux and the energy consumption by the pumps inside the process. Cases of single and multiple control inputs are considered through the use of only the feed pump flow rate or both the feed and the permeate pump flow rates. A nonlinear Lyapunov-based observer is designed to provide an estimation for the temperature distribution all over the designated domain of the DCMD process. Moreover, control inputs are constrained with an anti-windup technique to be within feasible and physical ranges. Performance of the proposed structure is analysed, and simulations based on real DCMD process parameters for each control input are provided.     

Attitude tracking control of a flexible spacecraft under angular velocity constraints

In this paper, a new technique is proposed for trajectory tracking of a flexible spacecraft subject to angular velocity constraints. The problem is addressed using an output to input saturation transformation (OIST) which converts the prescribed bounds into state-dependent saturations on the control input signals. It is shown that an interval observer can be used in combination with the OIST technique to ensure that the constraints remain satisfied despite unmeasured flexible modes and torque disturbances. Some realistic simulations conclude the paper and validate our approach.     

基于条件技术的Anti-windup设计及其在伺服系统中的应用

大多数执行器不可避免的会出现饱和现象,严重影响了系统的闭环性能,甚至影响系统的稳定性。为此,该文介绍了条件技术的Anti-Windup设计方法。通过引入“可行参考输入”的概念,设计了以传递函数形式表示的抗饱和补偿控制器。并用此方法有效地解决了某型电动转台伺服系统中存在的控制器Windup问题,仿真结果表明转台伺服系统性能得到改善。     

连铸动态二冷控制模型的开发与应用

采用跟踪单元法建立了连铸在线凝固传热模型,首次提出了"虚拟坯龄"的概念,并实现了铸坯实时温度场的计算。基于在线凝固传热模型,采用抗饱和自适应整定PID控制算法开发了连铸动态二冷控制模型。生产应用结果表明,本控制模型具有较强的抗扰动能力,能够很好地实现铸机二冷配水的动态控制,使铸坯二冷水量在非稳态浇铸条件下平缓变化,正常拉速范围内铸坯表面温度波动小于±5℃,计算温度与实测温度及目标温度的差值控制在10℃以内,铸坯质量得到了明显的改善。