基于迭代学习控制的混合误差轮廓控制

针对永磁直线同步电动机直接驱动XY平台系统中存在不确定扰动的问题,单轴上设计了基于干扰观测器的迭代学习控制器.迭代学习控制器可以抑制重复扰动,干扰观测器可以消除非重复扰动的影响,两者结合起来可增强系统对重复和非重复扰动的抑制能力.由于轮廓误差计算模型要求跟踪误差远小于期望轮廓曲率半径,所以设计了混合误差轮廓控制器,跟踪误差较大时只控制各轴位置,跟踪误差足够小时进行轮廓控制.仿真结果表明,该控制方法使直接驱动XY平台具有较强的鲁棒性和较高的轮廓精度.     

A hybrid disturbance observer for delivery drone’s oscillation suppression

This paper proposes a new hybrid disturbance observer (DOB) to help suppress disturbance to the control systems. The proposed hybrid DOB consists of three main parts: (1) an actual system, (2) a simulated system, and (3) a learning filter that connects the actual and simulated systems. The simulated system aims to replicate the actual system response, where it leverages a neural network model to predict the input disturbance and generate the predicted system response. Such system response is used to generate a learning signal through a learning filter; this learning signal is then added to the feedforward loop of the estimation framework to enhance the disturbance estimate and its suppression performance for the actual system. The proposed hybrid DOB is designed to advance the standard DOB structure with a learning-based feedforward compensation. While the proposed method does not modify the baseline controller, it is well suited to systems whose baseline controllers are difficult or impossible to be changed. Considering the delivery drones are subject to oscillations when dropping payloads, experimental tests with multiple payload dropping scenarios have been conducted using both the hybrid and standard DOB, where the compared results validate the effectiveness and advantages of the proposed hybrid DOB.     

保证闭环系统鲁棒稳定性的干扰观测器系统性设计方法

研究带有干扰观测器(Disturbance observer,DOB)的反馈控制系统对模型不确定性鲁棒稳定的充分条件,在此基础上,选取满足此充分条件的加权函数,使得标准H∞干扰观测器设计方法保证对受控对象参数变化的鲁棒稳定性.提出了在H∞干扰观测器设计中兼顾鲁棒性设计指标和结构约束的频率加权函数的选取方法.利用加权函数选取的自由度,在干扰观测器低通滤波器设计中,实现Q—滤波器在截止频率上的高峰幅度与干扰抑制性能之间的最佳折中,使得干扰观测器在满足其幅度指标的条件下,具有最优干扰抑制性能.实验结果表明该方法保证了闭环反馈系统的鲁棒稳定性,同时,具有实现其他设计指标的自由度.     

基于简化干扰观测器的光电平台稳定与评估

单纯采用经典的比例积分（proportion integration,PI）校正难以进一步提高航空光电平台惯性稳定性能。本文分析了影响稳定精度的主要因素,设计了基于简化干扰观测器（disturbance observer,DOB）的航空光电平台稳定控制算法。该方法由DOB和PI控制器构成,其中DOB 采用陀螺反馈,利用等效变换实现,无需求取被控系统的逆模型。此外,本文提出一种基于隔离度测试的航空光电平台稳定性能评价方法。在实际系统中进行了惯性稳定实验,采用所提出的稳定控制方法获得了10 μrad（RMS）的稳定精度,并且采用新方法的隔离度测试结果在30 Hz频带内的姿态扰动下较传统PI控制均有显著的提高。     

Generalized-Extended-State-Observer and Equivalent-Input-Disturbance Methods for Active Disturbance Rejection: Deep Observation and Comparison

Active disturbance-rejection methods are effective in estimating and rejecting disturbances in both transient and steady-state responses.This paper presents a deep observation on and a comparison between two of those methods:the generalized extended-state observer(GESO) and the equivalent input disturbance(EID) from assumptions,system configurations,stability conditions,system design,disturbance-rejection performance,and extensibility.A time-domain index is introduced to assess the disturbance-r...     

3G及TD-SCDMA务实发展策略

在概述3G及TD-SCDMA进展基础上，重点论述了TD-SCDMA系统的优势与面临的挑战。独立组网与混合组网的利弊及务实发展策略。     

A rigorous small area modelling-study for the helicobacter pylori epidemiology

This paper presents an investigation into spatial risk differences over small distances for the Helicobacter pylori infection in the city of Leipzig, Germany and two rural districts. A model, using Bayesian inference, was developed that adjusts the risk for individual-specific factors, and for spatial or individual over-dispersion, respectively. Additionally, the model takes into account conditional spatial autocorrelation. We found a significant positive association to the H. pylori infection risk for: “more than three children live in the household” (OR = 2.4, p = 0.001), “more persons live per sq.m than average” (OR = 1.4, p = 0.03), “home situated at main road” (OR = 1.4, p = 0.04) and “using well water” (OR = 2.3, p = 0.05). A protective effect was identified for “travelled to low prevalence region” (OR = 0.4, p < 0.0001) and “born in Germany” (OR = 0.2, p < 0.0001). Three administrative areas with significantly increased spatial risk were identified: one in the rural district and two in the city of Leipzig. The model explained 24.9% of the total deviance. Contrary to expectations, the largest part of deviance of the data was not explained by the identified significant risk factors, but by individual-specific heterogeneities. We conclude that further - so far not discussed - factors influence the risk and the spatial variation of the H.pylori infection. Furthermore, from the results we speculate about a possible impact of long-time air pollution and surface water.     

砂质黏土中不同深度爆炸自由场地冲击参数预计方法研究

 根据爆炸地冲击试验的主要影响因素,运用量纲分析方法推导出爆炸地冲击参数的经验表达式。由砂质黏土中不同深度爆炸地冲击试验所得的地冲击应力峰值衰减曲线可以看出,装药比例埋深变化范围为－0.2～1.0 m/kg1/3,装药比例埋深对地冲击应力峰值的大小有较大影响,但应力峰值的衰减规律是一致的,即应力峰值经验公式的衰减指数大致相同,只是衰减系数随装药比例埋深的增加而增大。当装药比例埋深达到0.80 m/kg1/3以后,地冲击应力峰值衰减曲线之间的间距已经很小,这说明装药到此比例埋深以后装药比例埋深对爆炸地冲击参数的影响不再明显。在上述砂质黏土中不同深度爆炸自由场地冲击衰减规律的基础上,以“等效当量埋深系数”定义同一介质在相同比例距离上产生相同地冲击强度的2种不同深度爆炸装药量之间的关系,并运用此系数给出砂质黏土中不同深度爆炸自由场地冲击参数的预计方法,为地下工程抗爆研究与结构设计提供荷载依据。     

基于扰动观测器的电压源型逆变器控制

基于扰动观测器(DOB)的原理,结合PWM电压源型逆变器受控对象的特点,为逆变器提出了一种新的控制策略,并设计了相应的附加型扰动观测器。将附加型扰动观测器作为补偿器添加到传统的双环反馈控制系统中,提高了逆变器输出的抗干扰性能和动态响应速度。这种附加型扰动观测器结构简单、实现时所需计算量小且不需要增加新的采样信号,适合工程应用。在基于DSP MC56F8323的PWM逆变器系统中对新的控制系统和传统的控制系统进行比较,该附加型扰动观测器的有效性和实用性得到了验证。