基于多学科虚拟样机的粘着控制仿真平台

重载列车和准高速动车组的运行,使轮轨之间的粘着经常处于极限状态,因此需要研究更先进的控制方法来优化利用粘着力。建立了包括牵引系统、控制系统和机车多体动力学模型的多学科虚拟样机仿真平台。使用机械动力学仿真软件ADAMS/Rail建立了某种电力机车的多体动力学仿真模型;利用MATLAB建立了组合粘着控制算法;通过联合仿真实现了针对机车粘着控制系统的多学科虚拟样机仿真。联合仿真平台成为了沟通粘着控制方法理论研究和试验研究的桥梁,为智能控制方法在粘着系统中的应用提供了有效的仿真环境。

Abstract：

With heavy-haul train and high-speed electric multiple unit （EMU） operation,the adhesion between wheel and rail often reaches limit states.Therefore the advanced control arithmetic should be studied to optimize the use of the adhesion force.A simulation platform was built including traction system,control system and multi-body dynamics model of an locomotive.The model of the electric locomotive was established with ADAMS/Rail （Automatic Dynamic Analysis of Mechanical Systems）.Then a hybrid adhesion control algorithm was designed using MATLAB.The adhesion control system can be studied with co-simulation of different simulation tools.The theoretical and experimental studies are realized with the simulation platform.It provides a new and effective ways to study the adhesion control.     

汽车轮缸压力传感器故障重构方法研究与仿真

针对汽车液压制动系统中轮缸压力传感器的故障重构问题,建立了汽车液压制动系统的轮缸压力非线性模型。在此基础上,给出了一种基于滑模观测器的轮缸压力传感器故障重构方法,并将滑模观测器的设计问题转化为LMI求解问题。最后对轮缸压力传感器断路故障进行了仿真研究,讨论了不同增益对故障估计的影响。

Abstract：

A fault reconstruction scheme based on the sliding mode observer was proposed for the fault reconstruction of the wheel cylinder pressure sensor in the vehicle hydraulic braking system, as well as a nonlinearity model of the wheel cylinder in the hydraulic braking system. Furthermore, the design of the sliding-mode observer was converted to the solving of the LMI. In conclusion, the wheel cylinder pressure sensor open circuit fault simulation experiment and the influence on fault estimation over the different gain were proposed.     

车辆半主动悬架系统模糊神经网络控制研究

悬架系统对车辆平顺性具有重要的影响,通过预瞄控制在后轮处提前预测路面不平度,用于解决半主动悬架模糊神经网络控制存在的时滞问题。建立了1/2车辆模型和路面输入模型,设计了基于预瞄控制的半主动悬架模糊神经网络控制结构,并进行了白噪声输入仿真分析。结果表明：预瞄控制后的车身加速度峰值和标准差比被动系统分别减少了61.61%和44.28%,比模糊控制的悬架系统分别减少了21.23%和21.20%;预瞄控制后的质心加速度峰值和标准差比被动系统分别减少了35.21%和57.81%,比模糊控制的悬架系统分别减少了7.83%和20.10%。后轮处车身加速度和质心垂直加速度均有明显减小,较好改善了悬架系统适应道路的性能,有效缓和了车辆的振动和提高了汽车的行驶平顺性。

Abstract：

Suspension system has important effect on vehicle ride comfort.Wheelbase preview control method could be used to forecast the road surface roughness at the front wheel,and to be used to solve the delay problem in fuzzy neural network controlled semi-active suspension system.The 1/2 vehicle model and road input model was established,and the fuzzy neural network control structure based on wheelbase preview control theory was designed.The white noise input simulation was carried out and the results show that the peak and standard deviation of body acceleration are separately decreased by 61.61% and 44.28% compared with passive suspension system,and are 21.23% and 21.20% compared with fuzzy controlled suspension system;on the other hand,the peak and standard deviation of vertical acceleration at CG are separately decreased by 35.21% and 57.81% compared with passive suspension system,and are 7.83% and 20.10% compared with fuzzy controlled suspension system.The body vertical acceleration at rear wheel and the vertical acceleration at CG are significantly decreased to adapt to the suspension performance,which helps to effectively easy the vehicle vibration and to improve the vehicle ride comfort.     

Multi-target localization for bistatic MIMO radar in the presence of unknown mutual coupling

A decoupling-estimation signal parameters via rotarional invariance technique(ESPRIT) method is presented for multi-target localization with unknown mutual coupling in bistatic multiple-input multiple-output(MIMO) radar.Two steps are carried out in this method.The decoupling operation between angle and mutual coupling estimates is realized by choosing the auxiliary elements on both sides of the transmit and receive uniform linear arrays(ULAs).Then the ESPRIT method is resilient against the unknown mutual coupling matrix(MCM) and can be directly utilized to estimate the direction of departure(DOD) and the direction of arrival(DOA).Moreover,the mutual coupling coefficient is estimated by finding the solution of the linear constrained optimization problem.The proposed method allows an efficient DOD and DOA estimates with automatic pairing.Simulation results are presented to verify the effectiveness of the proposed method.     

Study on the Robot Robust Adaptive Control Based on Neural Networks

Force control based on neural networks is presented. Under the framework of hybrid control, an RBF neural network is used to compensate for all the uncertainties from robot dynamics and unknown environment first. The technique will improve the adaptability to environment stiffness when the end-effector is in contact with the environment, and does not require any a priori knowledge on the upper bound of syste uncertainties. Moreover, it need not compute the inverse of inertia matrix. Learning algorithms for neural networks to minimize the force error directly are designed. Simulation results have shown a better force/position tracking when neural network is used.     

强横风对轿车气动性能影响数值分析

强横风对高速行驶轿车的操纵稳定性具有重要影响。建立5-9级强横风和不同车速条件下24个轿车参数模型,为减小阻塞效应选用合理的计算域并采用混合网格离散,采用K-ε双方程和速度压力SIMPLE耦合方法分析轿车气动特性,并与无横风时的气动特性进行比较,结果表明：5-9级强横风对不同行驶速度轿车的气动性能均具有较大影响;气动侧向力和横摆力矩会使轿车发生侧滑或偏离航向角;在9级横风作用下轿车的侧倾力矩随车速发生急骤变化,易造成车辆左右摇摆和侧翻,应及时发布风力预警。

Abstract：

Strong crosswind has important effect on automobile steering stability while its running speed is high. The 24 parameter models were set up under 5-9 grade crosswind and at different running speed. To reduce blocking effect rational computational zones were defined and meshed with hybrid mesh technology. Aerodynamic characteristics were analyzed by using k-ε double equation and SIMPLE method for velocity-pressure couple. Aerodynamic characteristics under strong crosswind were compared with those under no crosswind. Results show that 5-9 grade strong crosswind has great influence on aerodynamic characteristics of a sedan at different speed, and aerodynamic lateral force and yawing moment can make sedan sideslip or change course angle, and roll moment of the sedan under 9 grade crosswind varies with running speed quickly and it will make the sedan swing or rollover, and wind warning should be issued in time.     

液压剪叉式升降台的动力学仿真

为了减小剪叉式升降台运动过程中的加速度和节点力,以内装式液压单片剪叉式升降台为研究对象,推导了液压缸驱动速度与机构运动速度的关系,利用ADAMS软件进行了机-液联合动力学仿真,分析了液压系统中方向控制阀的控制函数对机构运动学特性的影响,得到了控制函数的优选方案。其分析方法与结论对剪叉式升降台及其液压系统设计具有指导作用。

Abstract：

In order to reduce the acceleration and force of scissors elevating platform in the process of motion, the relationship between the velocity of hydraulic cylinder and scissor mechanism was derived for the single scissors mechanism. The dynamic property of scissors elevating platform was analyzed using by ADAMS software. The influence of the control function for the dynamic property was studied, and the optimum project of control function was acquired. The methods and conclusions are available for designers of scissors elevating platform and hydraulic circuit.     

多步块格式求解微分-代数方程

多步块格式是一类新的一般线性方法,在求解微分-代数方程的过程中不会出现精度降低现象。研究了多步块格式的构造方法,精度条件及具有Runge-Kutta稳定性的多步块格式,多步块格式具有刚性精确的优点,且级精度与格式精度相等。构造了具有Runge-Kutta稳定性的2级和3级多步块格式,具有L-稳定性。数值算例证实多步块格式在求解微分-代数方程不会精度降低。

Abstract：

The multistep block methods are a new class of general linear methods,and the methods solve the differential-algebraic equations with no order reduction.The construction of the multistep block methods was described,and order condition and stability was studied.The multistep block methods with Runge-Kutta stability were also constructed.The multistep block methods have many nice properties,for example,stiffly accurate,and stage order is equal to order of method.At last the methods of 2-stage and 3-stage with Runge-Kutta stability were constructed,and they have the property of L-stability.The numerical example shows that the multistep block methods can solve the differential-algebraic equations without the order reduction.     

变速磨削抑振的试验分析

通过在磨削外圆中，使砂轮或工件的转速按一定规律变化的试验分析表明，砂轮或工件变速都有抑制颤振的作用，其原因是变速改变了砂轮和工件间的瞬时速比，使径向磨削力均值下降，减小了砂轮和工件间的接触刚度，增加了系统稳定性.     

机车车辆-轨道空间耦合动力学性能仿真系统

基于系统观点,采用先进的动态轮轨空间接触几何关系模型,编制了具有自主知识产权的机车车辆-轨道耦合动力学仿真系统TTISIM。该系统引入了三维建模技术和可视化技术,并建立了机车车辆和轨道基于变参数的三维动态视景环境。TTISIM仿真系统侧重于分析机车车辆在实际弹性轨道上运行的安全性、舒适性,服务于我国铁路现代化建设主战场,具有很强的工程应用价值。     

汽车制动防抱系统的混合建模与仿真研究

在分析汽车制动防抱系统(ABS)工作特点的基础上,指出汽车ABS是由连续系统与离散系统组成的混合系统,进而提出基于有限状态机与Matlab/Simulink的ABS混合建模方法。利用混合建模方法建立了某轻型客车的ABS仿真模型并进行了低附着系数道路条件下的仿真研究,探讨了制动器制动力、电磁阀响应时间和车轮转动惯量对汽车ABS性能的影响。仿真结果表明基于混合建模的ABS仿真系统能很好的模拟汽车ABS的性能;制动器制动力、电磁阀响应时间和车轮转动惯量对ABS制动性能影响的分析为ABS的设计提供了依据。     

双系缆气球绳网系统抗风能力的仿真分析

为研究一种双系缆气球绳网系统的设计和使用的问题,在系统动力学模型的基础上对系统的抗风能力进行了分析。仿真出双系缆气球绳网系统在常值风作用下的空间姿态、受力状况,以及在典型风场作用下的动力学响应。分析了常值风的速度、风向对系统的影响,并研究了气球阻力系数、气球容积及气球蒙皮面积质量密度主要设计参数对双系缆气球绳网系统抗风能力、结构载荷的影响。仿真计算结果表明双系缆气球绳网系统具有较强的抗风能力,为系统的设计提供了依据。     

对抗仿真系统中的防空导弹比例导引法仿真弹道设计

针对某型防空导弹，利用一系列假设，设计满足对抗仿真系统需求的比例导引法仿真弹道；运用瞬时平衡法对导弹气动力参数进行处理，形成平衡升力系数和平衡侧力系数；在导弹控制系统理想工作情况下，运用弹体法向、侧向受力与控制系统产生的需求力相等的假设，建立弹道方程；通过仿真可以看出，利用的假设和建立的弹道方程是正确的，能够描述某型防空导弹的弹道特性。     

侧风状况下轿车气动特性的仿真与实验研究

以获得适合计算侧风气动特性的湍流模型为目的,应用计算流体动力学方法对比了标准k模型、RNG k模型、Realizable k模型以及SST模型对不同横摆角状态下轿车气动特性仿真结果的影响。结果表明,当0时,采用Realizable k湍流模型仿真得出的阻力系数与实验结果最为吻合,误差仅为1.53%,侧力系数的仿真结果与理论分析更为吻合;当3～1 5时,采用Realizable k湍流模型仿真得出的阻力系数与实验结果相比误差最大为0.96%,侧力系数的仿真结果与实验结果趋势一致,误差最大也仅为4.9%。总之,Realizable k湍流模型能够很好的模拟侧风状态下车辆的气动特性,仿真结果为进一步分析车辆的侧风稳定性提供了参考数据。     

树在风中摆动的计算机实时模拟方法研究

提出了一种生成树叶和树枝在风中摆动动画的计算机方法,该方法考虑了风速、风力和噪音.根据空气动力学给出了一个能很好反映风的物理作用的计算公式,并在力学分析的基础上给出了计算树叶和树枝变形的数学公式,利用这些公式,并结合1/fβ噪音技术,可以计算每一个树叶和树枝的变形,进而可以得到整个树的变形.利用这种方法可以很快得到树在风中摆动的效果,实现树在风中摆动的计算机模拟.     

Electricity Price of Hybrid Power System and Decision Making of Renewable Energy Investment Capacity

In the existing electricity market,the traditional power suppliers and renewable energy generators coexist in the power supply side. In the power supply side,renewable energy generators generate power by wind and other natural conditions,leading renewable energy output a certain randomness. However,the low marginal generating cost and the reduction of carbon emissions,and thus brings a certain advantage for renewable energy compared to alternative energy. Electricity,as a special commodity,stable and adequate power supply is a necessary guarantee for economic and social development. Power shortage situation is not allowed in the power system,and the extra power needs to be handled for the purpose of safety. In this paper,the hybrid power generated by renewable energy generators and traditional energy generators is used as power supply,and then the electricity market sells hybrid power to electricity consumers,the hybrid power system determines the optimal daytimeprice,nighttime price,and the optimal installed capacity of the renewable energy suppliers. We find that the installed capacity of renewable energy increases first and then decreases with the increase of the price sensitivity coefficient of traditional energy supply. Electricity demand is negatively related to electricity price in the current period,and is positively related to price in the other period. The average price of day and night is only related to the total potential demand of day and night and the total generation probability of renewable energy. The price difference between daytime and nighttime is positively related to potential electricity demand,and negatively related to the sensitivity coefficient of electricity price.     

面向国家标准的汽车转向机构安全性仿真

国家标准《防止汽车转向机构对驾驶员伤害的规定》中规定了防止转向机构对驾驶员构成伤害的技术要求和当汽车受正面撞击时转向盘向后窜动的试验方法，转向盘遭受撞周时吸收能量的试验方法，本文以某车型及其转向机构为研究对象建立有限元模型，按国家标准规定的试验条件对两项技术要求进行计算机仿真，仿真结果与试验结果吻合，因此利用仿真技术对评价汽车转向机构碰撞安全性具有一定的指导意义。