Practical Implementation of Embedded Controlled Reduced Switch Z-Source Inverter-Fed Induction Motor Drive

A cost-effective component minimized embedded controlled Z-source inverter for induction motor drive is presented. The proposed topology combines the advantages of a traditional four-switch three-phase inverter with the advantages of the z impedance network (two inductors in series and two X connected capacitors). This new topology, besides the self-boost property, has low switch count and it can operate as a buck-boost inverter. As a result, the new embedded controlled reduced switch Z-source inverter system provides ride through capability during voltage sags, reduces line harmonics, improves power factor, reliability and extends output voltage range. Analysis, simulation and experiment result will be presented to demonstrate these new features.

Slip-draft embedded control system by adaptively adjusting the battery position for electric tractor

A slip-draft embedded control system was designed and developed for an independent developed 2WD(two-wheel drive)electric tractor,to improve the traction efficiency,operation performance and ploughing depth stability of the electric tractor.In this system,the battery of electric tractor was innovatively equivalent to the original counterweight of the fuel tractor.And through dynamic analysis of electric tractor during ploughing,the mathematical model of adjusting the center of gravity about draft force and slip rate was established.Then the automatic adjustment of the center of gravity for electric tractor was realized through the adaptive adjustment of battery position.Finally,the system was carried on electric tractor for performance evaluation under different ploughing conditions,the traction efficiency,slip rate and front wheel load of electric tractor were measured and controlled synchronously to make it close to the set range.And the comparative experiments of ploughing operation were carried out under the two modes of adaptive adjustment of center of gravity and fixed center of gravity.The test results showed that,based on the developed control system,the center of gravity of electric tractor can be adjusted in real time according to the complex changes of working conditions.During ploughing operation with adjusting adaptively battery position,the average values of traction efficiency,slip rate,front wheel load and relative error of tillage depth of electric tractor were 64.5%,22.2%,2045.0 N and 2.0%respectively.Which were optimized by 15.0%,29.5%,19.6%and 80.0%respectively,compared with electric tractor with fixed battery position.The slip-draft embedded control system can not only realize the adaptive adjustment of the center of gravity position in the ploughing process of electric tractor,but also improve the traction efficiency and the stability of ploughing depth,which can provide reference for the actual production operation of electric tractor.

Fault-Tolerant Scheduling for Real-Time Embedded Control Systems

With the increasing complexity of industrial application, an embedded control system (ECS) requires processing a number of hard real-time tasks and needs fault-tolerance to assure high reliability. Considering the characteristics of real-time tasks in ECS, an integrated algorithm is proposed to schedule real-time tasks and to guarantee that all real-time tasks are completed before their deadlines even in the presence of faults. Based on the nonpreemptive critical-section protocol (NCSP), this paper analyzes the blocking time introduced by resource conflicts of relevancy tasks in fault-tolerant multiprocessor systems. An extended schedulability condition is presented to check the assignment feasibility of a given task to a processor. A primary/backup approach and on-line replacement of failed processors are used to tolerate processor failures. The analysis reveals that the integrated algorithm bounds the blocking time, requires limited overhead on the number of processors, and still assures good processor utilization. This is also demonstrated by simulation results. Both analysis and simulation show the effectiveness of the proposed algorithm in ECS.

A Fuzzy Logic Based Supervisory Hierarchical Control Scheme for Real Time Pressure Control

This paper describes a supervisory hierarchical fuzzy controller （SHFC） for regulating pressure in a real-time pilot pressure control system. The input scaling factor tuning of a direct expert controller is made using the error and process input parameters in a closed loop system in order to obtain better controller performance for set-point change and load disturbances. This on-line tuning method reduces operator involvement and enhances the controller performance to a wide operating range. The hierarchical control scheme consists of an intelligent upper level supervisory fuzzy controller and a lower level direct fuzzy controller. The upper level controller provides a mechanism to the main goal of the system and the lower level controller delivers the solutions to a particular situation. The control algorithm for the proposed scheme has been developed and tested using an ARM7 microcontroller-based embedded target board for a nonlinear pressure process having dead time. To demonstrate the effectiveness, the results of the proposed hierarchical controller, fuzzy controller and conventional proportional-integral （PI） controller are analyzed. The results prove that the SHFC performance is better in terms of stability and robustness than the conventional control methods.

Tufting Carpet Machine Information Model Based on Object Linking and Embedding for Process Control Unified Architecture

In view of the lack of research on the information model of tufting carpet machine in China,an information modeling method based on Object Linking and Embedding for Process Control Unified Architecture(OPC UA)framework was proposed to solve the problem of“information island”caused by the differentiated data interface between heterogeneous equipment and system in tufting carpet machine workshop.This paper established an information model of tufting carpet machine based on analyzing the system architecture,workshop equipment composition and information flow of the workshop,combined with the OPC UA information modeling specification.Subsequently,the OPC UA protocol is used to instantiate and map the information model,and the OPC UA server is developed.Finally,the practicability of tufting carpet machine information model under the OPC UA framework and the feasibility of realizing the information interconnection of heterogeneous devices in the tufting carpet machine digital workshop are verified.On this basis,the cloud and remote access to the underlying device data are realized.The application of this information model and information integration scheme in actual production explores and practices the application of OPC UA technology in the digital workshop of tufting carpet machine.

从嵌入到融入:“一村一警”警务机制创新路径研究

嵌入性理论框架下,“一村一警”机制嵌入乡村治理的行动逻辑可解构为制度嵌入、职能嵌入、资源嵌入、技术嵌入、情感嵌入五大维度。基于当前“一村一警”警务机制运行受“反嵌入”制约的现实困境,应积极探索“一村一警”从嵌入乡村向融入乡村的行动范式转变;以制度融入筑牢制度基础,以职能融入理清职责角色,以资源融入充实硬件保障,以技术融入增添科技赋能,以情感融入激发群众活力,推动“一村一警”警务机制真正融合于乡村治安治理之中,弥补农村治安防控体系建设的薄弱环节,实现维护社会整体安全与稳定的价值目标。

网络嵌入对消费者团购意愿影响的实证研究

网络团购以其独特的消费模式广受消费者、供应商及相关电子商务网站青睐。以往关于团购的相关文献主要着眼于消费者个体特征对网络团购意愿的影响,缺乏基于群体视角的研究。而随着互联技术的提高,消费者参加网络团购这一行为是嵌入于社会网络之中的,其决策必然受到群体因素影响。鉴于团购环境的改变,以社会网络理论为基础,探讨了网络群体结构嵌入、关系嵌入对团购购买意愿影响的作用机理,检验了感知控制和信任的中介效应,并对比分析了不同团购方式的影响程度。实证结果表明,对于网站发起式团购和消费者发起式团购方式,网络结构嵌入和关系嵌入的影响程度有显著差异。

疫情防控视域下社区媒介参与社区治理的路径优化:演进韧性与技术嵌入

演进韧性强调系统在危机中变化、适应和转变的能力,为现代风险社会中社区媒介参与社区治理的路径优化提供了新的理论资源和视角。据此审视疫情防控中邻里互助、技术嵌入下以信任与合作为基础的多元交叉网络、社区中“隐私悖论”负面性的消解及微基建项目的推进发现,疫情防控期间社区的内部边界并未封闭,居民主导的治理模式在强调社区韧性的背景下愈发重要。社区媒介结合互联网、大数据、区块链等新一代信息技术的去中心化赋权,为居民自治机制中由“精英模式”向“共建人模式”转型提供了替代方案:通过设计基于区块链技术的社区社交媒介,在其与线下公共空间的互动中完成共建人的开发与培养,继而发展多样的内生性社区自组织以建立居民自治主导的社区韧性。

河长制视域下技术嵌入对公众治水参与的影响——基于5省份调查数据的实证分析

公众参与对河长制从制度优势转化为治理效能具有重要推动作用。随着新一轮信息技术革命的发展,以治水投诉微信公众号、河长制APP、河长制信息管理系统等为代表的技术治理模式凭借其交互性、便捷性、开放性等优势,赋予了公众更加广泛、自主、充分的参与权,被认为拥有增进公众治水参与的巨大潜力,但这一潜力如何在河长制政策执行中得以兑现是一个有待深入探讨的问题。文章从嵌入性理论和公众参与理论出发,聚焦数字化与河长制背景下的公众治水参与,将公众参与划分为侧重于前端治理的建言献策和后端治理的举报投诉两类,利用江苏、湖北、陕西、河南、宁夏5省份1635个流域居民的微观调查数据,采用Probit模型实证检验了技术嵌入对公众治水参与的影响及机制,并进一步运用条件混合估计法(CMP)和倾向得分匹配法(PSM)进行内生性处理及稳健性检验。研究发现:①河长制视域下技术嵌入对公众治水参与具有显著正向影响,不仅能够促进前端公众建言献策,还能够增强后端公众举报投诉,即使采用不同样本、不同方法重新估计后,这一实证结果依然显著成立。②技术嵌入对公众治水参与的促进作用依公众技术使用权限、河长制推行时间、东中西地区的差异而存在异质性。③进一步的机制分析发现,政府治水形象在技术嵌入与公众治水参与之间发挥部分中介作用;同时,技术嵌入也能够通过改变公众预期水平这一机制变量,进而促进公众举报投诉,但对公众建言献策未能有显著影响。上述研究发现为理解和推动公众治水参与和智慧水利建设提供了理论解释和经验证据,也为增强河长制治理效能提供了政策启示。

Embedded model control:Reconciling modern control theory and error-based control design

The paper addresses the problem of reconciling the modern control paradigm developed by R. Kalman in the sixties of the past century, and the centenary error-based design of the proportional, integrative and derivative （PID） controllers. This is done with the help of the error loop whose stability is proved to be necessary and sufficient for the close-loop plant stability. The error loop is built by cascading the uncertain plant-to-model discrepancies （causal, parametric, initial state, neglected dynamics）, which are driven by the design model output and by arbitrary bounded signals, with the control unit transfer functions. The embedded model control takes advantage of the error loop and its equations to design appropriate algorithms of the modern control theory （state predictor, control law, reference generator）, which guarantee the error loop stability and performance. A simulated multivariate case study shows modeling and control design steps and the coherence of the predicted and simulated performance.

Algorithmic approaches for optimizing electronic control unit time using multi-rate sampling

With the emerging migration of automotive and other distributed control platforms from federated to integrated architectures, the need for optimal utilization of ECU （electronic control unit） bandwidth will become a key requirement in the implementation of embedded control features. This paper advocates the partitioning of the operating space of the plant and the use of minimal sampling rates in each partition without compromising the overall quality of control. At the heart of the proposed methodology are our algorithms that enable the choice of the partitions and the sampling rate for each partition. We demonstrate the efficacy of our methods on two case studies, namely an anti-lock braking system and a lane departure warning system. We also study the use of a supervisory controller that controls the switching among sampling rates for a combination of the two features.

Design of high-speed and low-power finite-word-length PID controllers

ASIC or FPGA implementation of a finite word-length PID controller requires a double expertise： in control system and hardware design. In this paper, we only focus on the hardware side of the problem. We show how to design configurable fixed-point PIDs to satisfy applications requiring minimal power consumption, or high control-rate, or both together. As multiply operation is the engine of PID, we experienced three algorithms： Booth, modified Booth, and a new recursive multi-bit multiplication algorithm. This later enables the construction of finely grained PID structures with bit-level and unit-time precision. Such a feature permits to tailor the PID to the desired performance and power budget. All PIDs are implemented at register-transfer4evel （RTL） level as technology-independent reusable IP-cores. They are reconfigurable according to two compilemtime constants： set-point word-length and latency. To make PID design easily reproducible, all necessary implementation details are provided and discussed.

我国农用地膜污染防治生产者责任延伸制的实践与展望

[目的]在农村人居环境整治和乡村生态振兴背景下,农用地膜污染治理已成为关注重点之一。系统研究如何将生产者责任延伸制引入农用地膜污染治理过程,实现“谁污染,谁付费”的农用地膜产品生命周期闭环,可为全国农用地膜污染高效治理提供可借鉴的方式和经验。[方法]文章在系统梳理农用地膜治理政策基础上,结合案例分析系统研究了农用地膜回收生产者责任延伸制建立、运行、发展的途径和规律,提出地膜污染治理过程中生产者责任延伸制市场化模式的影响机制。[结果]市场化模式制度嵌入的失效,是农用地膜残留污染治理问题的主要症结,生产者责任延伸制重新建立了地膜残留污染治理责任的分摊机制,是更为可靠的市场化模式,但其构建也陷入“市场化模式实现条件的苛刻性”和“企业垄断的必然性与市场配给的竞争性之间的矛盾”双重困境;此外,从具体原因来看,制度嵌入影响机制还包括政府投入机制建立、企业责任落实与利益诉求的平衡,以及农户价值诉求识别偏差等方面。[结论]因此,政府应在推动和维护机制建立运行过程中,完善制度保障,考虑企业利益导向,帮助农户识别价值诉求,推进生产者责任延伸制跳出困境,有效融入农用地膜市场场域,引导构建市场化模式。

母子公司人员嵌入、控制层级与子公司代理成本

母子公司代理问题的实质是二者间的权力分配问题,涉及母公司如何高效率地监督管理子公司。本文将母子公司间的管控方式分为人员管控(董事嵌入和监事嵌入)、层级管控两类,基于代理理论研究其对子公司代理费用与代理效率的影响。本文利用2009—2016年上市公司数据研究发现:母子公司间董事嵌入有效降低了子公司的代理费用,提高了代理效率,监事嵌入与子公司代理费用、代理效率关系均不明显;金字塔控制层级同时提高了子公司的代理费用与代理效率,但是对代理效率的正向影响高于代理费用;人员管控方式中董事嵌入削弱了控制层级与子公司代理费用的正向关系,监事嵌入约束了控制层级对代理效率的积极影响。进一步研究发现,母子公司间董事嵌入、监事嵌入均降低了母公司对上市子公司的掏空行为。本文从集团公司治理的角度研究母子公司权力分配问题,为母公司如何管理子公司提供了参考建议。

社会网络嵌入对农户绿色防控技术采用的影响——基于技术认知的中介效应

分析不同社会网络嵌入对农户绿色防控技术采用的影响及其作用机制,可为政府完善绿色农业技术推广政策提供决策参考。本文利用河南、陕西和甘肃790份苹果种植户微观调查数据,运用社会网络分析方法构建农户村域社会网络矩阵,基于关系嵌入和结构嵌入,探讨何种社会网络嵌入影响农户绿色防控技术采用及其作用机制。结果发现:(1)关系嵌入能显著提高农户采用绿色防控技术的可能性,结构嵌入的影响效应不显著。在控制其他因素的情况下,农户关系嵌入每增加一个单位,采用绿色防控技术的概率将提高13.5%~31.4%。(2)机制分析表明,关系嵌入通过增强农户技术认知广度和深度促进其采用绿色防控技术,结构嵌入对农户绿色防控技术采用的影响受到示范效应的调节,表现为结构嵌入仅对高示范效应组的农户绿色防控技术采用具有显著的正向影响,对低示范效应组的农户影响不显著。根据研究结论本文提出,政府应注重农户所嵌入的社会网络在绿色防控技术扩散中的媒介作用,加强农户互动水平,强化种植大户和家庭农场主的示范带动作用,加快实现农业绿色转型。