Direct Yaw Moment Control for Distributed Drive Electric Vehicle Handling Performance Improvement

For a distributed drive electric vehicle（DDEV） driven by four in-wheel motors, advanced vehicle dynamic control methods can be realized easily because motors can be controlled independently, quickly and precisely. And direct yaw-moment control（DYC） has been widely studied and applied to vehicle stability control. Good vehicle handling performance： quick yaw rate transient response, small overshoot, high steady yaw rate gain, etc, is required by drivers under normal conditions, which is less concerned, however. Based on the hierarchical control methodology, a novel control system using direct yaw moment control for improving handling performance of a distributed drive electric vehicle especially under normal driving conditions has been proposed. The upper-loop control system consists of two parts： a state feedback controller, which aims to realize the ideal transient response of yaw rate, with a vehicle sideslip angle observer; and a steering wheel angle feedforward controller designed to achieve a desired yaw rate steady gain. Under the restriction of the effect of poles and zeros in the closed-loop transfer function on the system response and the capacity of in-wheel motors, the integrated time and absolute error（ITAE） function is utilized as the cost function in the optimal control to calculate the ideal eigen frequency and damper coefficient of the system and obtain optimal feedback matrix and feedforward matrix. Simulations and experiments with a DDEV under multiple maneuvers are carried out and show the effectiveness of the proposed method： yaw rate rising time is reduced, steady yaw rate gain is increased, vehicle steering characteristic is close to neutral steer and drivers burdens are also reduced. The control system improves vehicle handling performance under normal conditions in both transient and steady response. State feedback control instead of model following control is introduced in the control system so that the sense of control intervention to drivers is relieved.

Stress distribution and surrounding rock control of mining near to the overlying coal pillar in the working face

The occurrence of overlying coal pillar(OCP)exerts a strong effect on the stress and strain distribution of the surrounding rock in the stope.In this paper,the stress distribution characteristics are analyzed via the numerical calculation with the account of OCP presence or absence.In addition,this study revealed the joint effect of side pressure relief area of the goaf and stress concentration in OCP on the final stress distribution.Furthermore,the rules of abutment stress distribution affected by three influencing factors,namely horizontal-vertical distances between OCP and working face and buried depth of OCP,are analyzed.The functional model linking the peak stress of surrounding rock with the above influencing factors is developed.The field application of the above results proved that the rib spalling and deformation of a 2.95 m-high and 5.66 m-wide roadway could be efficiently controlled by rationally adjusting working states of the support,and adopting the hydraulic prop coordinated with the p type metal beam and anchor cable to strengthen the surrounding rock of working face and roadway,respectively.The proposed measures are considered appropriate to satisfy the safe operation requirements.

Cloud Control Systems

The concept of cloud control systems is discussed in this paper, which is an extension of networked control systems (NCSs). With the development of internet of things (IOT), the technology of NCSs has played a key role in IOT. At the same time, cloud computing is developed rapidly, which provides a perfect platform for big data processing, controller design and performance assessment. The research on cloud control systems will give new contribution to the control theory and applications in the near future. © 2014 Chinese Association of Automation.

Characteristics of stress distribution in floor strata and control of roadway stability under coal pillars

Given the difficulties encountered in roadway support under coal pillars,we studied the characteristics of stress distribution and their effect on roadway stability,using theoretical analysis and numerical simulation.The results show that,under a coal pillar,vertical stress in a floor stratum increases while horizontal stress decreases.We conclude that the increased difference between vertical and horizontal stress is an important reason for deformation of the surrounding rock and failures of roadways under coal pillars.Based on this,we propose control technologies of the surrounding rock of a roadway under a coal pillar,such as high strength and high pre-stressed bolt support,cable reinforcement support single hydraulic prop with beam support and reinforcement by grouting of the surrounding rock,which have been successfully applied in a stability control project of a roadway under a coal pillar.

Analysis on Structural Control of Coal Distribution in the Northern Qaidam Basin,NW China

The distribution of the Jurassic coal measures in the northern Qaidam Basin is obviously controlled by the regional structures. Based on the existing data of coalfield exploration and combined with the analysis of coalfield basement structures, features of the main faults, and the distribution of coal measures, this paper brings forward a scheme of coalfield tectonic divisional units and the definition of the coal-controlling structural styles in the northern Qaidam Basin. The structure control of the distribution of coal measures is further discussed. Several stages of regional tectonic activities since the Indosinian has led to the distribution of coal measures into the characteristics of zonation from the north to south and block from east to west. The results indicate that the structural deformations are the most intense in the front of the three uplifted belts, which are characterized by the combination of thrusts. The coal measures are uplifted to the shallow formations, and are easy to be exploited, but the scale of mines is small because of serious damages by the coal distribution. On the contrary, the stress and strain are weak in the three depressions, with the coal-controlling structural styles being mainly the thrust-fold and thrust-monocline combinations. The distribution of coals in the depressions is relatively stable. The shallower part of the depression will become the key areas for exploration and development of coal resources in the northern Qaidam Basin.

ControlNet控制系统网络设计优化

通过分析Control Net网络原理并结合具体的生产工艺流程,设计了基于Control Net网络的控制系统;同时,针对网络设计存在的问题提出了Control Net网络优化方案并在实际生产中具体实施。应用结果表明,网络划分和网络关键参数设置是非常行之有效的优化方案,成功地解决了生产中出现的Control Net网络故障,各项指标满足了控制要求,同时对Control Net控制系统网络的设计和优化有一定的参考价值。

电厂智能输煤一体化分散控制系统的研究与应用

以电厂输煤系统为分析对象,完成该电厂输煤PLC控制系统的设计。设计输煤控制系统的主电路和PLC控制电路;在硬件设计的基础上,完成输煤PLC控制系统的程序流程功能设计;以WinCC组态软件为依托平台,开发该输煤控制系统的上位机监控系统画面,完成该火力发电厂输煤远程监控系统的组态设计;设计远程监控系统的各种图形界面和监控功能,实现对输煤系统的远程监控。

基于PLC技术的火电厂输煤翻车机电控系统改造设计

为了全面提高煤炭的运输效率和安全性,火电厂对输煤翻车机进行了进一步改造。在改造后,通过利用PLC技术控制输煤翻车机日常运行,科学设计输煤翻车机电控系统,并在程序上进行实现,为火电厂高效运行打下坚实的基础。基于此,以PLC技术概念为基础,分析了PLC技术控制类型,明确了输煤翻车机自动控制功能,主要包括装煤自动化、配煤自动化、启停自动化等,并将PLC技术应用到火电厂输煤翻车机电控系统改造中,合理设计了翻车机主程序,并充分发挥其作用,提高了翻车机运行效率,保证了煤炭运输工作能顺利进行。

珠江口盆地惠北地区煤系烃源岩新认识与勘探实践

珠江口盆地恩平组煤系烃源岩因分布主控因素认识不清、发育规模不明确,导致勘探潜力被忽视。以煤系烃源岩发育区惠北地区作为研究靶区,利用地震、钻井和地化等资料,系统分析了煤系烃源岩分布主控因素,据此确定煤系烃源岩发育规模和资源潜力,从而有效指导勘探。研究表明:①纵向上,从恩四段到恩一二段沉积期,惠北地区古气候温暖湿润,古水深逐渐变浅,古构造活动强度逐渐减弱,恩一二段和恩三段有利于煤层的发育和聚集,恩四段沉积期煤层不发育;②横向上,受古沉积条件的控制,煤系烃源岩主要分布于惠州14洼北部缓坡带辫状河三角洲河道间的河漫沼泽和洼陷带滨浅湖内的湖沼范围内。基于煤系烃源岩分布规律,预测惠北地区煤系烃源岩资源量约2亿方油当量,带动了惠北地区周边勘探,也展示了珠江口盆地煤系烃源岩勘探前景。

矿用分布式驱动铰接车辆差速控制策略研究

针对矿用分布式驱动铰接车辆在转向时容易打滑的问题,提出一种基于PID滑模控制的电子差速控制策略。建立了分布式驱动铰接车辆的动力学模型和基于运动学模型的滑移率计算模块,基于PID滑模面和指数趋近律设计了PID滑模控制器。通过MATLAB/Simulink对分布式驱动铰接车辆转向工况进行了仿真。结果表明:基于PID滑模控制的差速控制策略在小角度和大角度转向工况下内外侧车轮均具有良好的差速性能,即使部分车轮进入低附着路面,车轮滑移率也有效调控在0.2附近。该差速控制策略可以有效减少打滑,减轻轮胎磨损,对于提高矿用分布式电驱动铰接车的稳定性与动力性具有重要意义。

矿井通风瓦斯防治技术

矿井通风在瓦斯防治中发挥着重要的作用。结合A矿8303工作面的具体情况,分析了矿井通风瓦斯防治技术。分析了矿井的风量分配,根据实际情况,对矿井总风量进行了校核。最后,探讨了生产过程中的通风管理。在矿井通风瓦斯防治中,风量分配是基础,通风管理是保证。研究可以为矿井通风瓦斯防治提供一定的参考。

采煤工作面围岩稳定性控制分析

目前,随着社会经济的快速发展,人们越来越注重企业生产的经济效益和效率,也更加重视保障工作人员的安全。为了更加高效地控制采煤工作面围岩稳定性,应针对采煤工作面围岩进行分析与研究,再制定相应的围岩控制措施,实现对采煤工作面围岩稳定性的有效控制,降低生产事故发生的风险,提高围岩稳定性。主要对采煤工作面围岩稳定性控制进行了分析。

基于有限元模拟的地热资源勘探及分析

在煤矿开采过程中,容易出现高温热害,直接影响了采矿工作的安全性。在避免矿井热害的同时,为了进一步有效利用区域内的地热资源,提出了一种地热资源勘探方法,并对区域内地热分布情况进行分析。以钻孔系统测温法为基准探测结果,并结合研究区域实际情况建立有限元模型。在确定上下边界、参数取值、网格划分方法后,通过数值模拟对区域内地热资源分布及地热产生原因进行了分析。研究结果表明,区域内地热资源量为2.30×10^(19)J,可采热能储量为2.55×10^(18)J,可转换成标准煤0.88亿t。这说明研究区域蕴含巨大的地热资源,具有较高的利用价值。研究成果为区域煤矿开发热害防治以及地热资源综合开发利用提供了地质依据,可进一步促进煤矿开采的可持续发展。

采煤机机载式喷雾引射控降尘装置优化及应用研究

以高庄煤业3下502工作面为研究对象,对采煤机割煤时机身段风速和粉尘分布特征进行分析,采煤机机载式喷雾引射控降尘装置从喷雾引射风量和结构两方面进行优化设计.结果表明,应用优化控降尘装置后,可对含尘风流进行控风,采煤机割煤时司机处的呼吸尘和总尘的降尘效率分别达到92.7%和86.5%,控降尘效果显著.

张家湾煤矿工作面上覆煤柱附近开采应力分布及围岩控制

上覆煤柱的赋存对采场围岩的应力和应变分布具有强烈的影响,通过数值计算分析有无上覆煤柱情况下的应力分布特征,研究上覆煤柱与工作面的水平、垂直距离及上覆煤柱埋深3个影响因素对支承应力分布的影响规律,并建立围岩峰值应力与上述影响因素之间的函数模型。模拟结果表明,煤壁片帮的发生对工作面应力分布有显著影响,无上覆煤柱时,超前峰值应力较高,影响范围较小。现场实践表明,工作面频繁出现强矿压显现,当工作面回采至上覆煤柱时,巷道变形达到危险值,通过合理调整液压支架工作状态,煤壁片帮得到了充分控制,巷道高度和宽度分别保持在2.95和5.66m,保证了工作面的安全生产。

配电网故障处理及运行控制技术标准体系建设

配电系统是构建新型电力系统的关键领域,技术标准为技术开发、应用等提供了统一的遵守依据,是推动技术创新、提高整个产业技术水平的重要手段。围绕新型电力系统的要求,分析配电网故障处理及运行控制方面的业务需求及面临的挑战,建设配电网故障处理及运行控制技术标准体系,能够指导配电网相关领域科技创新和标准精准科学布局,为新型电力系统高质量发展提供有力支撑。

燃煤锅炉分布式控制系统设计

燃煤锅炉是一种重要的能量转换设备,对其燃烧过程的稳定控制是燃料充分燃烧的必要条件。为提高锅炉系统的环保性,采用工控机(Industrial Personal Computer,IPC)与可编程逻辑控制器(Programmable Logic Controller,PLC)相结合的方式,设计了燃煤锅炉的分布式控制系统。以给煤量控制为例,阐述了控制方法的设计过程。依据燃煤锅炉的工艺过程,采用WinCC组态软件设计监控系统,以实现锅炉的远程交互控制,提高锅炉运行的安全性和稳定性。

价值工程在采空区注浆防灭火技术中的应用探索

本文深度挖掘价值工程的七个逻辑步骤,选定宁夏金凤煤矿大采高工作面采空区自燃问题作为改进对象,通过收集和分析煤矿作业环境、工作面特点及煤层自燃机理等情报资料,进行了详细的功能分析,确定了煤炭自燃风险的核心影响因素。并由此提出了采空区注浆技术作为改进方案,通过数值模拟验证并评价了改进活动的价值成果,本研究不仅解决了采空区自燃问题,进一步展示了价值工程方法在煤矿采空区自燃问题防治中的应用领域的重要价值。

构造煤分布规律对煤与瓦斯突出的控制

根据对华北366对主要生产矿井统计分析,得出构造煤的区域分布主要受构造控制,挤压构造带是构造煤主要分布区,其次是伸展构造带的边缘,伸展构造带的内部主要是原生结构煤分布区;构造煤的层域分布主要受煤厚控制,即构造煤主要发育在厚煤层中;构造煤最发育的区域和层位,煤与瓦斯突出也最严重。纵弯褶皱作用下构造煤主要形成在褶皱的翼部,断层作用下构造煤主要形成在断层的上盘,因此,褶皱的翼部和断层的上盘也是煤与瓦斯突出最严重的部位。

四轮轮毂电机驱动电动汽车电机/液压系统联合控制策略

针对四轮轮毂驱动电动汽车,以改善车辆稳定性为目标,设计了轮毂电机与液压制动系统联合控制策略。控制器采用分层控制结构,上层应用滑模变结构理论求取广义力,下层采用二次规划法进行转矩优化分配,同时考虑执行器的位置与速度约束。通过CARSIM软件与MATLAB软件的联合仿真进行算法验证。结果表明:在极限工况下,无控制或仅有电机控制的车辆都无法完成仿真工况,而电机系统与液压系统联合的控制策略则可以保证车辆的操纵稳定性。