Predictive control for mechanical system with backlash based on hybrid model

The mechanical system with backlash is distinguished between a＂backlash mode＂and a＂contact mode＂.The inherent switching between the two operating modes makes the system a prime example of hybrid system.For eliminating the bad effect of backlash, a piecewise affine（PWA） model of the mechanical servo system with backlash is built.The optimal control of constrained PWA system is obtained by taking advantage of model predictive control（MPC） method, and the explicit solution of MPC in a look-up table form is figured out by combining the dynamic programming and multi-parametric quadratic programming, thereby establishing an explicit hybrid model predictive controller.Furthermore, a piecewise quadratic（PWQ） function for guaranteeing the stability of closed-loop control is found by formulating the search of PWQ function as a semi-definite programming problem.In the tracking experiments, it is demonstrated that the explicit hybrid model predictive controller has a good traction control effect on the mechanical system with backlash.The error meets the demands of real system.Further, compared to the direct on-line computation, the computation burden is reduced by the explicit solution, thereby being suitable for real-time control of system with short sampling time.

Research on Online-Offline Hybrid Teaching Mode of College English in the Context of New Liberal Arts

English is an important course in colleges,and students’proficiency in the language can significantly affect their learning in multiple disciplines.At present,offline classroom teaching is still the primary mode of college English teaching,and online teaching has not been widely used.Under the background of new liberal arts,the teaching tasks and objectives of college English have changed,and it is imperative to carry out online-offline hybrid teaching mode.This paper analyzes the feasibility of the online-offline hybrid teaching mode of college English,summarizes its problems,and explores its implementation strategies in the context of the new liberal arts,to provide references for teachers.

A New Classification Method of Stress Modes in Hybrid Stress Finite Element

The paper presents a new method for classifying the stress modes in hybrid stress finite element in terms of natural stress modes in finite element and the rank analysis of matrix G in forming element It reveals the relation among the different assumed stress field, and gives the general method in forming stress field Comparing with the method of eigenvalue analysis, the new method is more efficient

Study on integrated development and hybrid operation mode of nuclear power plant and pumped-storage power station

The nuclear power plant is suitable for base-load operation, while the pumped-storage unit mainly gives play to capacity benefit in the electric power system;hence, the integrated development and hybrid operation mode of the two can better meet the needs of the electric power system. This article first presents an analysis of the necessity and superiority of such mode, then explains its meaning and analyzes the working routes. Finally, it proposes the business modes as follows: low price pumping water electricity plus nuclear power in the near term;nuclear power shifted to pumped storage power participating in market competition in the middle term;and, in the long term, nuclear power shifted to pumped storage power as primary and serving as an electric power system when needed.

Research on Online and Offline Hybrid Teaching Mode under the Concept of OBE ——A Case Study for Software Engineering

With the support of the Ministry of Education’s Industry-Academia Collaborative Education Project and the critical project of Shandong Province’s education and teaching reform,we explore student-centered education reform positively to learn outcome-driven,which have the characteristics of a solid foundation,intense practice,strict process,and innovation.Under the technical support of the“Internet+”smart education,our practice has formed an online and offline hybrid teaching mode based on the effective interaction of teaching total factor under the OBE concept.Based on Bloom’s Taxonomy and Outcomes-based Education(OBE),this model formulates the overall objectives of the curriculum and the detailed objectives of each teaching step,plans the online and offline teaching design as a whole,and implements the target teaching by classification.Based on Laurillard’s scientific model of designing teaching sessions,we continuously iterate over the teaching steps like teacher communication,teacher demonstration,peer communication,and peer demonstration following the agile education concept.In the meantime,comprehensive application of SPOC online platform,Mu classroom,smart classroom offline carrier,WeChat/QQ social software,and other technical means facilitates the design for student-student interaction,teacher-student interaction,student-student discussion,teacher-student discussion,and other scenarios,realizing the combination of online and offline environment,of study independently and in the group,of flipped classroom and seminars.

A Single Mode Hybrid Ⅲ-Ⅴ/Silicon On-Chip Laser Based on Flip-Chip Bonding Technology for Optical Interconnection

A single mode hybrid Ⅲ-Ⅴ/silicon on-chip laser based on the flip-chip bonding technology for on-chip optical interconnection is demonstrated. A single mode Fabry-Perot laser structure with micro-structures on an InP ridge waveguide is designed and fabricated on an InP/AIGaInAs multiple quantum well epitaxial layer structure wafer by using i-line lithography. Then, a silicon waveguide platform including a laser mounting stage is designed and fabricated on a silicon-on-insulator substrate. The single mode laser is flip-chip bonded on the laser mounting stage. The lasing light is butt-coupling to the silicon waveguide. The laser power output from a silicon waveguide is 1.3roW, and the threshold is 37mA at room temperature and continuous wave operation.

MOOC construction of major core course and reform of Hybrid Teaching Mode Taking "principle of embedded system" as an example

The development of MOOC directly promotes the reform of physical classroom teaching,and leads to the reform of teaching mode and teaching method in the direction of improving teachers’teaching quality and students’learning effect and innovation ability.In order to meet the needs of MOOC teaching reform,based on the MOOC built by ourselves and running on the MOOC platform,this paper puts forward the hybrid teaching mode reform of the core courses of an computer specialty,which combines online and offline in depth.Sort out the knowledge system of an embedded system,build MOOC and put it online on domestic well-known MOOC platform,compile supporting teaching materials,and form an organic combination of online and offline teaching resources;proposing a hybrid teaching mode of online and offline combination,which focuses on interactive classroom teaching reform.On the basis of organizing students to carry out online autonomous learning,online and offline entity classroom carries out interactive classroom teaching reform;Using intelligent teaching tools to promote students to use mobile phones to participate in classroom learning,improve the universality of interactive teaching,carry out flipped classroom teaching,and improve the depth of interactive teaching.Based on the independent construction of MOOC,the hybrid teaching is carried out,which improves the pertinence of online teaching organization.The information-based teaching and flipped classroom teaching in the physical classroom improve the students’ability to solve problems,and lay a solid foundation for the improvement of teaching quality and learning effect.

Design of Engine-Generator Work Mode for Hybrid Electric Vehicle

From electric circuit theory view, a system model of series hybrid electric vehicle was built which uses engine-generator and battery pack as its on-board energy source in this paper. Based on the analysis for the constant power work mode and constant bus voltage work mode of engine-generator, a third work mode was put forward which combined the advantages of constant power and constant bus voltage work modes. The new work mode is reasonable to keep the battery in good working conditions and to extend its life. Also the working conditions of engine can be bettered to get low pollution and high efficiency.

Simulation research of energy management strategy for dual mode plug-in hybrid electrical vehicles

In this paper, a plug-in hybrid electrical vehicle(PHEV) is taken as the research object, and its dynamic performance and economic performance are taken as the research goals. Battery charge-sustaining(CS) period is divided into power mode and economy mode. Energy management strategy designing methods of power mode and economy mode are proposed. Maximum velocity, acceleration performance and fuel consumption are simulated during the CS period in the AVL CRUISE simulation environment. The simulation results indicate that the maximum velocity and acceleration time of the power mode are better than those in the economy mode. Fuel consumption of the economy mode is better than that in the power mode. Fuel consumption of PHEV during the CS period is further improved by using the methods proposed in this paper, and this is meaningful for research and development of PHEV.

Investigation of lower hybrid current drive during H-mode in EAST tokamak

H-mode discharges with lower hybrid current drive （LHCD） alone are achieved in EAST divertor plasma over a wide parameter range. These H-mode discharges are characterized by a sudden drop in Da emission and a spontaneous rise in main plasma density. Good lower hybrid （LH） coupling during H-mode is obtained by putting the plasma close to the antenna and by injecting D2 gas from a pipe near the grill mouse. The analysis of lower hybrid current drive properties shows that the LH deposition profile shifts off axis during H-mode, and current drive （CD） efficiency decreases due to the increase in density. Modeling results of H-mode discharges with a general ray trueing code GENRAY are reported.

以培养自主学习能力为导向的中医康复科线上线下混合住培模式构建

以培养自主学习能力理念为导向,构建中医康复科的线上线下相结合的住院医师规范化培训新模式,更新并完善教学设计,充实教学内容。利用教学短视频等信息化教学资料传播方式,使线上和线下教学内容形成互补,并紧密结合。尤其是在疫情期间,充分的线上教学资料保障了教学工作的稳定开展,现代化和信息化的教学方式受到学生认可与喜爱,提高了学生自主学习的积极性。但教学实践活动的开展效果要有相应的考核方法,基于上述新模式,还应建立过程性评价与终结性评价相结合的康复科考核办法,以提高学生的自主学习能力与临床综合实践能力。

Modeling and Control of Hybrid Machine Systems—a Five-bar Mechanism Case

A hybrid machine （HM） as a typical mechatronic device, is a useful tool to generate smooth motion, and combines the motions of a large constant speed motor with a small servo motor by means of a mechnical linkage mechanism, in order to provide a powerful programmable drive system. To achieve design objectives, a control system is required. To design a better control system and analyze the performance of an HM, a dynamic model is necessary. This paper first develops a dynamic model of an HM with a five-bar mechanism using a Lagrangian formulation. Then, several important properties which are very useful in system analysis, and control system design, are presented. Based on the developed dynamic model, two control approaches, computed torque, and combined computed torque and slide mode control, are adopted to control the HM system. Simulation results demonstrate the control performance and limitations of each control approach.

高职英语混合式教学模式构建及应用策略探究

近几年,以现代信息网络技术为支撑的混合式教学模式,因融合线上与线下教学的双重优势,为高职英语教学改革带来新机遇。通过构建高职英语混合式教学模式,能够在一定程度上弥补传统英语课堂教学单一性的弊端,以丰富多样的教学资源,多维度着手的教学模式,提升高职英语教学实效性。

Orthogonal basic deformation mode method for zero-energy mode suppression of hybrid stress elements

A set of basic deformation modes for hybrid stress finite elements are directly derived from the element displacement field. Subsequently, by employing the so-called united orthogonal conditions, a new orthogonalization method is proposed. The result- ing orthogonal basic deformation modes exhibit simple and clear physical meanings. In addition, they do not involve any material parameters, and thus can be efficiently used to examine the element performance and serve as a unified tool to assess different hybrid elements. Thereafter, a convenient approach for the identification of spurious zero-energy modes is presented using the positive definiteness property of a flexibility matrix. More- over, based on the orthogonality relationship between the given initial stress modes and the orthogonal basic deformation modes, an alternative method of assumed stress modes to formulate a hybrid element free of spurious modes is discussed. It is found that the orthogonality of the basic deformation modes is the sufficient and necessary condition for the suppression of spurious zero-energy modes. Numerical examples of 2D 4-node quadrilateral elements and 3D 8-node hexahedral elements are illustrated in detail to demonstrate the efficiency of the proposed orthogonal basic deformation mode method.

高渗透率新能源发电并网变流器跟网/构网混合模式控制综述

随着新能源发电渗透率的不断提升,目前以跟网型控制为主流的并网变流器稳定运行受到严峻挑战,具有主动电网支撑能力且弱电网稳定性强的构网型变流器控制技术受到广泛关注。然而,在高渗透率新能源发电条件下,尤其是末端弱电网中,并网变流器采用单一的跟网或构网模式控制难以兼顾稳定性、经济性和电网支撑性能。为此,国内外学者从2种模式的互补特性出发,提出并研究了跟网/构网混合模式控制策略,以期使并网变流器在弱电网下稳定运行的同时,最大限度地利用新能源,并取得优越的电网支撑性能。文中首先从跟网型与构网型变流器的基本控制结构出发,分析了跟网型和构网型变流器控制性能的互补特性;在此基础上,重点梳理了几种不同技术路线的混合模式控制方案,涉及多种单机混合控制策略和多机的场站级混合控制策略,并详细阐述了各方案的技术研究思路、原理和优缺点;最后,对跟网/构网混合模式控制技术的发展进行了展望。

基于虚拟仿真平台的线上线下混合式教学研究

伴随着大数据时代的来临,高等教育模式正面临着重大改革。为提高相似理论与相似方法课程的教学效果与质量,该文构建基于虚拟仿真平台的线上线下混合式教学模式,从课前学习、课上教学、课堂讨论和课后辅导等方面对混合式教学进行综合的论述,通过教学反思,对教学模式提出相应建议与心得,以期更好地提高学生学习的效率,为混合式教育模式的改革分享经验。

基于PBL-SPOC的留学生工程类课程教学模式探索———以采油工程为例

石油工程专业的留学生主要来自发展中能源国,留学生具有不同的文化背景和学习背景,对工程情景和案例等方面的学习需求度高。学生在工程类专业课程的学习过程中单一的线上、线下教学模式教学效果不理想。该文提出基于PBL-SPOC的混合教学模式,开展SPOC基础理论教学内容与资料的建设和线下PBL工程问题及案例的建设,通过合理的教学设计,实现线上SPOC基础理论和线下PBL工程问题和案例的贯通与互馈,为“一带一路”倡议新时代背景下来华留学生工程类专业课程教学提供新模式。

Improved Dynamic Response of DC to DC Converter Using Hybrid PSO Tuned Fuzzy Sliding Mode Controller

DC/DC switching converters are widely used in numerous appliances in modern existence. In this paper, the dynamic and transient response of phase shift series resonant DC/DC converter are improved using hybrid particle swarm optimization tuned fuzzy sliding mode controller under starting and load step change conditions. The aim of the control is to regulate the output voltage beneath the load change. The model of the hybrid particle swarm optimization tuned fuzzy sliding mode controller is implemented using Sim Power Systems toolbox of MATLAB SIMULINK. Performance of the proposed dynamic novel control under step load change condition is investigated.

基于MOOC的“高分子化学”线上线下混合式教学模式改革与研究

“高分子化学”是材料类专业的重要课程,理论体系严谨,知识点众多。传统教学方式难以引起学生兴趣,学习自主性较弱。通过构建基于MOOC的线上线下混合式教学,以问题为驱动,强化过程考核,学生参与度和自主学习效率得到了提高。由近年来本校高分子材料与工程专业学生的课程目标达成度评价数据发现,线上线下混合式教学和考核模式的改革产生了显著成效。

基于学习通和BOPPPS模型的跨校修读学分教学新模式研究——以《管理信息系统》为例

随着信息技术的发展,基于网络教学平台的线上线下混合教学模式,成为一种必然的发展趋势。大学生跨校修读学分是顺应教育的变革潮流,促进优质课程资源共享。以《管理信息系统》课程为例,在跨校修读学分的教学实践中,采用学习通和BOPPPS模型相结合的线上线下混合教学模式,以学生发展为中心,思政为引领,能力培养为本位,对传统的教学方式进行改革,最终达到了推进优质资源共享,激发教师的教学热情,提高学生的学习兴趣和主动性,提升学生的内驱力和学习能力的目的。