Analysis to the Driving Force Model and Drives Factor on the Utilized Changes of Cultivated Land in Qinghai Lake Area

Using path analysis, correlation analysis, partial correlation analysis and system dynamics method to study the driving force of cultivated land in Qinghai Lake Area, and using gradually regression analysis to establish the driving force model of utilized change of cultivated land. Driving factors, action mechanism and process of utilized change of cultivated land were analyzed, and the differences during all factors were compared. The study provides some decision basis for sustainable utilization and management of land resources in Qinghai Lake Area.

Controller design based on viscoelasticity dynamics model and experiment for flexible drive unit

In order to ensure that the system has the advantage of light weight and vibration absorption, the steel rope is used as a flexible transmission part. A flexible drive unit(FDU) is developed, whose features are guided by steel rope, increasing force by the movable pulley group, modular, convenient and flexible. Dynamics model for controller is deduced based on the constitutive equation of viscoelasticity. Controller is designed for position control and is based on the viscoelasticity dynamics model compensation control strategy proposed. The control system is based on the TURBO PMAC multi-axis motion control card.Prototype loading experiments and velocity experiments results show that the FDU can reach 2 Hz with no load and the max speed of 30(°)/s. The FDU has the capability of the load torque 11.2 N·m and the speed of 24(°)/s simultaneously, and the frequency response is 1.3 Hz. The FDU can be used to be the pitch joint of hip for biped robot whose walking speed is 0.144 km/h theoretically.

Nonlinear Mathematical Modeling and Sensitivity Analysis of Hydraulic Drive Unit

The previous sensitivity analysis researches are not accurate enough and also have the limited reference value, because those mathematical models are relatively simple and the change of the load and the initial displacement changes of the piston are ignored, even experiment verification is not conducted. Therefore, in view of deficiencies above, a nonlinear mathematical model is established in this paper, including dynamic characteristics of servo valve, nonlinear characteristics of pressure-flow, initial displacement of servo cylinder piston and friction nonlinearity. The transfer function block diagram is built for the hydraulic drive unit closed loop position control, as well as the state equations. Through deriving the time-varying coefficient items matrix and time-varying free items matrix of sensitivity equations respectively, the expression of sensitivity equations based on the nonlinear mathematical model are obtained. According to structure parameters of hydraulic drive unit, working parameters, fluid transmission characteristics and measured friction-velocity curves, the simulation analysis of hydraulic drive unit is completed on the MATLAB/Simulink simulation platform with the displacement step 2 mm, 5 mm and 10 mm, respectively. The simulation results indicate that the developed nonlinear mathematical model is sufficient by comparing the characteristic curves of experimental step response and simulation step response under different constant load. Then, the sensitivity function time-history curves of seventeen parameters are obtained, basing on each state vector time-history curve of step response characteristic. The maximum value of displacement variation percentage and the sum of displacement variation absolute values in the sampling time are both taken as sensitivity indexes. The sensitivity indexes values above are calculated and shown visually in histograms under different working conditions, and change rules are analyzed. Then the sensitivity indexes values of four measurable parameters, such as supply pressure, proportional gain, initial position of servo cylinder piston and load force, are verified experimentally on test platform of hydraulic drive unit, and the experimental research shows that the sensitivity analysis results obtained through simulation are approximate to the test results. This research indicates each parameter sensitivity characteristics of hydraulic drive unit, the performance-affected main parameters and secondary parameters are got under different working conditions, which will provide the theoretical foundation for the control compensation and structure optimization of hydraulic drive unit.

Modelling of a Human Driver’s Interaction with Vehicle Automated Steering Using Cooperative Game Theory

The introduction of automated driving systems raised questions about how the human driver interacts with the automated system. Non-cooperative game theory is increasingly used for modelling and understanding such interaction, while its counterpart, cooperative game theory is rarely discussed for similar applications despite it may be potentially more suitable. This paper describes the modelling of a human driver’s steering interaction with an automated steering system using cooperative game theory. The distributed Model Predictive Control approach is adopted to derive the driver’s and the automated steering system’s strategies in a Pareto equilibrium sense, namely their cooperative Pareto steering strategies. Two separate numerical studies are carried out to study the influence of strategy parameters, and the influence of strategy types on the driver’s and the automated system’s steering performance. It is found that when a driver interacts with an automated steering system using a cooperative Pareto steering strategy, the driver can improve his/her performance in following a target path through increasing his/her effort in pursuing his/her own interest under the driver-automation cooperative control goal. It is also found that a driver’s adoption of cooperative Pareto steering strategy leads to a reinforcement in the driver’s steering angle control, compared to the driver’s adoption of non-cooperative Nash strategy. This in turn enables the vehicle to return from a lane-change maneuver to straight-line driving swifter.

Modeling and Analysis of Pumping Motor Drives in Hardware-in-the-Loop Environment

In the proposed paper, the new experimental results are described obtained from the laboratory stand and the model developed by the authors. A method of acquiring characteristics of a pump motor drive using a hardware-in-the-loop simulation approach is explained. To explore the centrifugal pumps manufactured by ABB, their own control system is used whereas an industrial pump is replaced with the specially designed simulator. To clarify the model topology and parameters, a double-machine assembly was designed and used as universal pump prototype. A library of reference and disturbance signals used in pumping was applied as a modeling tool. In this way, the advantages of mathematical and physical simulations have been combined with optimal interaction of both approaches.

Effective way of alleviating poverty against poverty control: Based on the model of "Three Drives, Four Joints" in Zhen'an County

Based on the survey research of poverty controlling model of "Three Drives, Four Joints" in Zhen'an County, its forming motives, implementing mechanism, and constraint factors have been explored to testify its enlightenment and applicability, establishing a promotable, applicable, and effective poverty alleviation model. "Three Drives, Four Joints" model is linked to the poor who lacks ability of self-development. Relying on the drives from key leading companies, the capable and the rich, a community with shared interests by the poor and the subjects of the "three drives" could be formed through "Joint Production, Joint Resources, Joint Community of Stock, and Joint Operation". The linked poverty alleviation development model of "the influential and the rich bring along the poor" and "A rich household would help the others" come into being. It is found out that the model of "Three Drives, Four Joints" is in essence a poverty alleviation method focusing on the increase of the income and diversified ways of increasing the earnings. Problems of poverty alleviation carrier and joint mechanism have been solved in the poverty alleviation process. The model is innovative in activating the resource elements, helping to move the poor out of poverty. A referential, copyable, and applicable model is offered to advance the poverty alleviation in mountainous areas in China.

Dynamic model and driving strategy of corporate social responsibility

Corporate social responsibility is the inevitable requirement for the survival and development of enterprises in modern society,as well as the basic guarantee for the sustainable development of economy and society.In order to analyze the driving factors of corporate social responsibility from both internal and external aspects,the dynamic model of corporate social responsibility was constructed,and the driving strategies of corporate social responsibility were also suggested.The driving factors of corporate social responsibility include not only the external constraints of policies,regulations and stakeholders,but also the internal requirements of the sustainable development of enterprises.Only when the external driving force is transformed into the spontaneous and conscious responsibility behavior of the enterprise,can the enterprise achieve its due effect.Moreover,in order to better fulfill the social responsibility,enterprise should build a management system of social responsibility,enhance the awareness of social responsibility,and promote the effective implementation of social responsibility projects.The relevant department should strengthen the all-round supervision of corporate social responsibility,and further improve the policies,laws and regulations related to social responsibility.Enterprises should strengthen communication with stakeholders,actively disclose social responsibility information,and constantly improve social responsibility behavior.By implementing social responsibility,enterprise can improve its business environment,enhance corporate brand image and core competitiveness,and promote the sustainable development of economy and society.

Study on Modeling and Control Strategy for Electric Drive Motor of Tracked Vehicles

Aimed at the requirements for electric transmission system of a military tracked vehicle, the motor's design indexes were analysed and calculated. A model based on saturate inductance parameter of interior permanent magnet (IPM) synchronous motor was brought forward by using finite element analysis. And its control strategy based on the largest running capability was studied also. The experiment results for a scale model show that the modelling method improves the model's accuracy, and the motor's control strategy is effective.

Modeling of large scale solar cell handling robot with belt-driven flexible arms

To increase the competition of the solar energy collection system, the size of the solar panel module during the manufacturing process is being increased continuously. As the size of the solar panel increases, the size of the robot to handle the panel increased also. The change in scale of the robot inevitably results ill the amplification of the adverse effect of tile flexure. The main source of the flexure in the large scale solar cell panel handling system is the long and thin fork fingers of the [land and the solar cell panel. In addition, tile belt-driven actuator system used by most of the large scale panel handling robot is another significant source of the vibration. In this paper, the flexible multi body dynamic model of a large scale solar cell panel handling robot, which is being designed and constructed with the help of Kyung Hee University, is developed. The belt-driven system in the robot is also modeled as flexible system and included ill the robot to represent the actual vibration characteristics of the actuator system. C 2013 The Chinese Society of Theoretical and Applied Mechanics. [doi： 10.1063/2.1301310]

中国四大城市群碳排放驱动因素时空分解研究

城市群是中国经济发展和能源消耗的集聚区域,也是碳排放的主要来源。研究中国典型城市群碳排放的时空演变特征及其影响因素对实现“双碳”目标具有重要意义。文中应用ST-IDA模型(时空指数分解分析法)和LMDI(对数平均迪氏指数法)分解法,分析2000—2019年京津冀、长三角、珠三角和成渝城市群的碳排放驱动因素(人口规模、经济水平、产业结构、能源强度和能源结构)。研究发现:2000—2019年间,四大城市群能源活动碳排放总体趋势均由高速增长阶段步入平稳增长阶段,其中成渝城市群已基本实现碳达峰;能源强度效应是影响碳排放空间差异的主要因素;人口规模扩张、经济发展水平提高和能源强度上升是促进碳排放增长的主要因素,产业结构和能源消费结构优化起到抑制作用;四大城市群碳排放的时空演变主要取决于工业部门。鉴于四大城市群呈现出不同的碳排放特征,未来应探索差异化、多元化的城市群减排路径,促进城市群碳减排。

东北三省农业碳排放时空分异特征及其关键驱动因素

推动农业低碳发展是应对气候威胁和农业面源污染的有效途径。本文基于IPCC和农用物资投入数据核算2000—2019年东北三省农业碳排放,利用空间自相关等方法分析其时空分异特征,通过LMDI指数分解模型和地理探测器探究农业碳排放驱动因素及其交互作用关系。结果表明:1)东北三省2015年农业碳排放总量达到峰值,约为1759.66万t,较2000年(1048.19万t)增加67.88%,年均递增4.53%;研究期整体呈现“先上升后下降”态势,碳排放增量变动可划分为“波动上升期(2000—2009年)—过渡期(2010—2015年)—平稳下降期(2016—2019年)”3个阶段。化肥施用是主要碳源,占比75.12%。2)分解模型测算结果表明,农业生产效率、农业产业结构和农业劳动力规模对碳排放具有抑制作用,其碳减排比例分别为207.31%、21.56%、20.72%;农业经济发展水平对碳排放表现出较强的推动作用,实现349.59%的碳增量。3)相较于单因子来说,农业经济发展水平、农业生产效率与农业产业结构之间交互结果对农业碳排放的影响呈非线性增强特征,农业劳动力规模与其他因素叠加均呈现出双因子增强的作用效果。以上研究结果表明东北三省农业碳排放受周边地区影响且影响程度不断加强,同时碳排放关键驱动因素之间存在协同作用。本研究成果为推动农业低碳发展提供理论基础与政策依据。

二维图纸驱动三维建模的方法

针对船舶设计过程中二维图纸和三维模型之间缺乏有效关联关系的现状,开展二维图纸驱动三维模型的方法研究。开展常用二维原理图绘制软件CAD和SP P&ID的对比分析;针对CAD软件和SP P&ID两种软件输出的不同形式的二维原理图,分别开展二维原理图驱动三维模型的方法研究,分析二维原理图驱动三维建模的流程,研究二维原理图驱动三维建模的机理,解决二维原理图和三维模型之间数据分离的问题,提高船舶设计效率。

基于生态驾驶的自动驾驶汽车交叉路口控制策略研究

为了进一步提高自动驾驶汽车在交叉路口行驶时的燃油经济性,基于模型预测控制(MPC)理论,量化分析了车辆安全性、经济性、舒适性等多性能指标函数及约束,并设计了以经济性为主的交叉路口自动驾驶汽车生态驾驶控制器。仿真结果表明,所提出的控制策略能够保证良好的安全性和舒适性,与LQR控制器相比,在有前车影响和无前车影响工况下的百公里油耗分别降低15.83%和34.98%。

重庆市中心城区城市空间扩展特征识别与未来演化模拟分析

城市时空演化特征模拟及驱动因素探究,可为区域城市发展规划和土地资源管理提供决策参考。基于城市空间扩展判别模式、空间扩展特征测度指标和PLUS模型,探究1980—2020年重庆市中心城区城市建设用地的城市扩展模式,分析空间格局变化特征,预测未来城市扩展趋势并揭示驱动因素。结果表明:1)1980—2020年,随着重庆市中心城区各方位扩展分异性缓慢上升,城市破碎化程度加剧,形成“多方向、多扩展翼、多条带”扩展模式,呈现“西快东慢、西南-东北延伸”分布格局;2)1980—2020年,重庆市中心城区扩展速度和强度呈现先上升后下降趋势,城市扩展方向由内部和边缘式填充向外部发展,城市形态由逐渐趋于紧凑向逐渐趋于松散、破碎和不规则化分布;3)未来2030年重庆市中心城区仍将向外围扩展,扩展速度有所减缓,扩展方向差异性明显,经济和规划政策因素的影响作用愈发凸显;4)地形、GDP、距水域的距离、距离道路距离和开发区规划是影响重庆市城市扩展快慢的主要驱动力。受地理条件限制,在“多方向、多条带”城市分布格局下,经济、交通、政策为核心的社会经济因素已成为驱动重庆市中心城区空间扩展的关键。建议未来充分发挥经济战略的动能作用,完善与周边城市的经济合作模式,响应区域经济高质量发展号召,增强城市的社会经济活力;加大基础设施投资,完善区县间交通路网,强化中心城市的辐射效应,以提升城市空间内部结构,带动区域发展;同时,考虑重庆市生态保护区、自然保护区及农耕地保护区域,将市政府生境保护纳入城市未来发展规划中,提高自然资源利用效率,统筹环境与城市协调可持续发展。

基于传递函数分析的双馈风力发电系统动态建模方法研究

以双馈风力发电系统(doubly-fed induction generator based wind energy conversion system,DFIG-based WECS)为例,利用小信号分析法推导出由风机、双质量块传动链构成的动力与传动系统通用传递函数方程。动力与传动系统传递函数的零极点位置、稳定性与系统参数及系统运行工作点相关。该传递函数可进一步分解为扭转分量和非扭转分量。传动链参数仅对扭转分量造成影响。在此基础上,建立了考虑动力传动、电机、变流器、控制等环节的风力发电系统传递函数模型。模型综合了各环节参数,可直观反映系统参数对系统响应的影响,有助于深入了解系统动态行为。算例及时域仿真结果证明了所提出传递函数模型的准确性和高效性,可为系统参数设计研究提供理论依据。

基于风险场的不同认知次任务下接管风险评估模型

为有效评估不同认知次任务下L3级自动驾驶车辆接管时的风险,开展了驾驶接管风险评估模型研究。设计了城市快速路紧急接管场景并开展不同认知次任务下的驾驶模拟试验。考虑轨迹场、势能场和行为场因素,构建了接管风险评估模型。采用接管风险指数法,验证了所建模型的有效性。结合实测数据,量化不同认知次任务和回避操作类型对接管风险场场强的影响。结果表明:被试者进行接管操作后1~9 s内模型接管风险指数分布情况的M-W检验和K-S检验结果均为p<0.05,说明模型可以有效评估车辆在接管过程中的接管风险。此外,模型接管风险指数的均方根误差均值(0.062)小于碰撞时间倒数的均方根误差均值(0.098),说明模型在表征风险的准确性方面要优于碰撞时间倒数。研究结果可为接管过程中的车辆运行风险评估和避撞设计提供借鉴和参考。

中国省域交通碳排放空间关联格局的驱动特征

利用我国2003~2020年省级交通碳排放数据,基于模体结构分析和指数随机图模型对中国交通碳排放空间关联网络的宏观格局、微观连通和驱动特征进行研究.结果表明,中国交通碳排放空间关联网络呈现周期波动特征,等级均衡化发展和核心虹吸的空间分布,演化出少核心—多半核心—边缘新格局,碳转移路径表现出明显的空间惰性与时间惯性以及区域集中性;经纪属性在推动跨区域交通协同减排的经济活动中发挥重要作用;内生网络的互惠性、连通性、集聚性对交通碳排放网络形成具有重要驱动作用,行为者属性中发出、接收、抑制、互惠的驱动关系明显,外部网络的影响具有明显的地理邻近效应,呈现出地理距离衰减规律特征.由此提出短期重大项目驱动,推动绿色交通转型联动;中期提升协同水平,加强跨区域交通碳减排协调机制;长期顶层零碳设计,工业化-产业化-市场化全面协同等政策建议.

基于动力学模型的手术器械夹持力估计研究

手术器械夹持力估计问题一直是微创手术机器人手术器械研究的重点。在微创手术过程中,夹持力过大会造成组织损伤,夹持力过小会使缝合针等脱落,引发危险。因此,研究如何估计手术器械夹持力是非常有必要的。根据手术器械的结构特点,提出了一种基于动力学模型的夹持力估计方法。建立的模型考虑了手术器械动力学模型、丝传动系统力和位移传递特性和直流电动机特性,得到了手术器械电动机电流和夹持力之间的关系;通过Matlab对夹持力模型进行仿真验证,得到了手术器械末端执行器随电动机电流变化的夹持力变化曲线。仿真结果表明,基于动力学模型的手术器械夹持力估计模型与实际情况相符,为后续的手术器械夹持力安全保障研究提供了理论依据。

基于DPSIR模型的秦岭北麓陕西城市群水安全评估及驱动因子识别

水安全评估是水资源开发利用与区域发展的基础。为了加强秦岭北麓陕西城市群可持续建设,助力秦岭“中央水塔”绿色发展,基于DPSIR模型构建秦岭北麓陕西城市群水安全评估体系,结合主客观综合赋权法与模糊综合评价法对区域2011~2021年水安全进行评估分级,并利用灰色关联度法分析其水安全的驱动因子。结果表明:秦岭北麓陕西城市群2011~2021年水安全状态变化具有一致性,波动中稳步提升。西安市水安全等级相较宝鸡市、渭南市上升趋势显著,于2021年转为无警状态;宝鸡市一直保持低警状态,而渭南市长期处于中警状态。陕西城市群的水安全状态及发展趋势与人均GDP、年降水量、人均用水量等10个驱动因子密切相关,其中经济因子是水安全等级呈现一致性的根本保证,社会和生态因子则是造成水安全差异性的主要原因。

多维驱动因素联动效应对企业数字化创新的影响——基于SEM与fsQCA的实证分析

随着云计算、大数据、人工智能等数字科技蓬勃发展,数字化创新深刻影响着企业创新与运营模式。利用结构方程模型(SEM)与模糊集定性比较分析方法(fsQCA)分析技术不确定性、市场不确定性、企业家精神、组织学习、组织忘记对企业数字化创新的影响。结果发现:技术不确定性、市场不确定性、企业家精神、组织学习、组织忘记和数字化创新6个要素存在因果线性关系,并发现学习主导型、市场驱动学习型和市场主导型3条数字化创新路径,以及3条非高数字化创新路径。其中,市场驱动学习型最有可能激发数字化创新。结合结构方程模型(SEM)分析结果,比较上述6条路径发现,数字化创新的影响因素具有非对称性,3条非高数字化创新路径并不是3条高数字化创新路径的对立面。