全程快速非线性跟踪-微分器

设计一种快速收敛的非线性跟踪-微分器,使系统在远离平衡点和接近平衡点都能自动快速地向平衡点收敛,并采用线性与非线性组合的连续函数形式,而不需要切换函数,从而防止了系统的抖振现象.     

非线性跟踪-微分器的分析与改进

本计非线性跟踪－微分器的工作机理和参数意义进行了深入分析，发现了超调产生的根源及参数相近制约的原因，通过对其开关平面函数的改进，改善了信号的品质，得到了灵活解耦的参数整定方法，使非线笥跟踪于微分器更具有工程实用意义。     

一种基于边界特征的简易非线性二阶离散跟踪微分器的设计

用等时区方法确定最速离散二阶系统的线性区域的边界,以开关曲线和边界线来界定控制量的线性变化,区分可达区和线性区,得到最速系统综合函数,并依此构造线性函数形式的跟踪微分器.仿真结果表明,所提出的跟踪微分器具有快速跟踪输入信号、无颤振、无超调的特点,能得到较好的微分信号,算法简洁实用.     

非线性跟踪-微分器的性能分析及其改进

对非线性跟踪-微分器的性质进行分析,用适当的指数函数形式取代开关函数,定性地讨论时间尺度的取值问题,使系统在扰动存在的情况下也能满足跟踪要求,同时对跟踪-微分器的稳定性进行了分析.     

非线性跟踪—微分器的性能分析及其改进

对非线性跟踪－微分器的性质进行分析，用适当的指数函数形式取代开关函数，定性地讨论时间尺度的取值问题，使系统在扰动存在的情况下也能满足跟踪要求，同时对跟踪－微分器的稳定性进行了分析。     

基于神经网络的跟踪-微分器设计

针对自抗扰控制的跟踪-微分器模块中存在着待定参数的问题,借助人工神经网络便于建立非线性映射的思想,提出了基于神经网络的跟踪-微分器的设计方法.运用该方法可以对任意阶的跟踪-微分器进行参数设计,设计出的跟踪-微分器具有良好的鲁棒性.仿真实验表明,由该设计方法设计出的跟踪-微分器能够提供精确的微分信号,有一定的工程应用参考价值.     

改进的非线性跟踪微分器设计

在对典型跟踪微分器深入研究的基础上,提出一种改进的非线性跟踪微分器.该跟踪微分器综合了线性跟踪微分器和非线性跟踪微分器的优点,不但无颤振现象,而且具有良好的动态响应和较强的滤波能力,兼顾了快速性和准确性的要求,可实现任意信号的跟踪和微分.该跟踪微分器形式简单、易于实现.仿真结果表明,改进型非线性跟踪微分器具有优良的性能.     

Robust stability of non-standard nonlinear singularly perturbed discrete systems with uncertainties

In the past several decades, the singularly perturbed discrete systems have received much attention for the stability analysis and controller design. Recently, there are some results about the nonlinear singularly perturbed discrete systems. Compared with the existing result, we consider the robust stability of the uncertain nonlinear singularly perturbed discrete systems with the less conservative assumption via the Lyapunov function method. Moreover, the previous results of the singularly perturbed discrete system are only applied to the system, which is composed of the slow part and the fast part, separately. However, we consider the non-standard nonlinear singularly perturbed discrete system in which the slow part and the fast part coexist, that is, a general case of the nonlinear singularly perturbed discrete systems. Then, by using the lower-order subsystems from two standard systems, we present the robust stability of the non-standard nonlinear singularly perturbed discrete system with uncertainties.     

Robust analysis of nonlinear discrete systems with multiple time delays

In this paper, we present the stability criteria, sufficient conditions that guarantee the robust stability of linear structured or unstructured variation of discrete time-delay systems subjected to the given bounds of nonlinear function. Both single and composite nonlinear discrete systems with multiple time delays are considered and each of these results is expressed by a succinct scalar inequality and independent of delay time.     

一种新型高精度非线性滤波算法研究

针对非线性、非高斯系统状态的在线估计问题,提出了一种新的高精度粒子滤波算法。该算法通过引入积分修正因子,对积分卡尔曼滤波器的积分点进行在线修正,并采用修正后的积分卡尔曼滤波产生优选的建议分布函数,由于高精度地融入最新量测信息,一定程度上克服了权值退化问题。仿真实验表明,新算法具有较高的滤波精度,是一种有效的非线性滤波算法。     

基于多通道高精度温度检测系统的设计

恒温箱的工作环境对仪器的功能的实现具有重要的影响,多通道高精度温度检测系统是恒温箱控制的前端数据采集部分。本文介绍了一套针对精密仪器工作所需的环境特点设计的多通道(8路温度)高精度温度测量系统,该系统能对仪器工作环境进行测试分析,并能将测量结果通过RS232C传递给PC机,以便整个系统的准确控制。     

超高精度计算程序设计实例

针对工程实践中时常出现超高精度计算的程序设计需求,分析超高精度乘、除法运算规则,提出超高精度整数与普通整数的乘除法运算算法及两个超高精度整数的乘除法运算算法,并分别给出时间复杂度分析及实验数据。给出3个完整的C语言程序,分别完成指定整数高次幂的精确计算并输出、按超高精度要求输出两个普通整数的商、超高精度求圆周率并输出。实验结果证明,在现有的常规软件及语言下,提出的超高精度计算的程序设计方法在工程实践中是简单可行的。     

一种高精度超声波测距系统研究

介绍了一种以单片机AT89S52为核心,同时用74LS04驱动超声波发射探头,用CX20106A对接收信号进行放大、滤波、检波并输出负脉冲的低成本、高精度超声波测距系统的硬件和软件设计方法。实验证明,这套超声波测距系统软硬件设计合理、抗干扰能力强、实时性好。     

基于RC充电时间过零点不变性的高精度高稳定振荡器

设计了RC充电时间过零点不变性振荡器,该振荡器提供对电压和温度不敏感的高精度高稳定性时钟信号。分析并推导了RC充电过程中过零电压的时间不随电源电压变化的特性,采用温度补偿技术最大限度地保证了RC充电过程中过零电压的时间不随温度变化。基于180 nm工艺实现了该振荡器,仿真结果表明,该振荡器可以稳定输出2 MHz,电压从2.5 V～5.5 V的频率波动小于1%,温度从-40℃～125℃的频率波动小于1%,PVT条件下的最大电流不超过150μA。     

A nonlinear sliding surface to improve performance of a discrete-time input-delay system

A sliding mode controller is proposed for an uncertain input-delay system to enhance performance. A nonlinear sliding surface is proposed to achieve better transient response for general uncertain discrete SISO linear systems with input delay. Both matched and unmatched perturbations are considered and ultimate boundedness of motion is proved. The step tracking problem is analysed. The proposed surface increases the damping ratio of the transformed system (delay free) as the output moves nearer to the setpoint. To simplify the surface design, a linear matrix inequality based tuning procedure is proposed. The control law is designed based on an equivalent control approach which guarantees one step reaching. The scheme is able to achieve low overshoot and low settling time simultaneously which is not possible with a linear sliding surface. Simulation results verify the effectiveness of the proposed nonlinear surface over different linear surfaces.