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1.
Computer simulation of active suspension based on the full-vehicle model   总被引:1,自引:0,他引:1  
The current method to solve the problem of active suspension control for a vehicle is often dealt with a quarter-car or half-car model.But it is not enough to use this kind of model for practical applications.In this paper,based on considering the influence of factors such as,seat and passengers a MDOF(multi-degree-of-freedom)model describing the vehicle motion is set up.The MODF model,which is 8DOF of four independent suspensions and four wheel tracks,is more applicable by comparison of its analysis result with some conventional vehicle models.Therefore,it is more suitable to use the 8DOF full-car model than a conventional 4DOF half-car model in the active control design for car vibration.Based on the derived 8DOF odel,a controller is designed by using LQ(linear quadratic)control theory,and the appropriate control scheme is selected by testing various performance indexes.Computer simulation 8is carried out for a passenger car running on a road with step disturbance and random road disturbance expressed by Power Spectral Density(PSD).Vibrations corresponding to ride comfort are derived under the foregoing road disturbances.The response results for uncontrolled and controlled system are compared.The response of vehicle vibration is greatly suppressed and quickly damped.which testifies the effect of the active suspenson.The results achieved for various controllers are compared to invesigate the influence of different control schemes on the control effect.  相似文献   

2.
In order to diminish the impacts of external disturbance such as parking speed fluctuation and model uncertainty existing in steering kinematics, this paper presents a parallel path tracking method for vehicle based on preview back propagation(BP) neural network PID controller. The forward BP neural network can adjust the parameters of PID controller in real time. The preview time is optimized by considering path curvature, change in curvature and road boundaries. A fuzzy controller considering barriers and different road conditions is built to select the starting position. In addition, a kind of path planning technology satisfying the requirement of obstacle avoidance is introduced. In order to solve the problem of discontinuous curvature, cubic B spline curve is used for curve fitting. The simulation results and real vehicle tests validate the effectiveness of the proposed path planning and tracking methods.  相似文献   

3.
One-dimensional traffic model was studied with the consideration of stochastic deceleration by using the lattice Boltzmannmethod.The evolution equation for vehicle density was derived,which has the form of the Burgers equation exhibiting the effect of viscosity corresponding to the deceleration.The simulation with the model shows that the variation of vehicle density in space tends to a periodic one,which implies the existence of kinematic waves in the 1D traffic flow and coincides with theoretical prediction.  相似文献   

4.
A model describing the absorption process of SO2 into limestone slurry with a spray scrubber is presented. Both the physical performance of the spray liquid in the scrubber and the involved chemical reactions are analyzed in the model. A continuous concentration change ofH+ was solved by iterative coupling using Matlab, and it was found that there was a remarkable influence on the concentration of the other elements in the process of SO2 absorption. The calculations show that the enhancement factor exponentially grows with an increasing value ofpH and logarithmically decays with an increasing value of the driving force. To verify the accuracy of the model, experiments were also carried out, and the results suggest that the model, after combining the physical performance of the spray and the enhancement factor, can more precisely describe SO2 absorption in a spray scrubber. Furthermore, a commercial computational fluid dynamics (CFD) tool is used to perform several simulations which describe and clarify the effects of variables on SO2 absorption. The results of numerical simulation can provide a basis for further design and optimization of the scrubber.  相似文献   

5.
The integration of water quality analysis simulation program (WASP) with a geographical information system (GIS) is presented.This integration was undertaken to enhance the data analysis and management ability of the widely used water quality model.Different types of data involved in WASP modeling were converted and integrated into GIS using a database method.The spatial data modeling and analysis capability of GIS were used in the operation of the model.The WASP water quality model was coupled with the environmental fluid dynamics code (EFDC) hydrodynamic model.A case study of the Lower Charles River Basin (Massachusetts,USA) water quality model system was conducted to demonstrate the integration process.The results showed that high efficiency of the data process and powerful function of data analysis could be achieved in the integrated model,which would significantly improve the application of WASP model in water quality management.  相似文献   

6.
Pat Hogan was traveling around the country in the car. One evening he was driving along a road and looking for a small hotel when he saw an old man at the side of the road. He stopped his car and said to the old man, “I want to go to the Sun Hotel. Do you know it?“  相似文献   

7.
This paper developed 3D product models of motorcycle and engine by UGNX as well as virtual prototyping by ADAMS program with road roughness generated by MATLAB. Under the straight-line running condition, the dynamic responses of motorcycle multibody system to both road and engine excitations were compared with those to only road excitation in terms of vertical acceleration response, amplitude frequency response and power spectral density. The comparisons of simulation data showed that the response due to flat road excitation was around 20 Hz, while that to the combined excitations was in a wide frequency band, of which the major components focused on 10 Hz, 15 Hz, 35 Hz ,70 Hz, 100 Hz and even higher frequencies, reflecting the characteristics of engine excitation based on its unbalanced inertia force and torque. It is concluded that the high fidelity virtual prototyping can simulate the dynamics of motorcycle product well in investigating the vibration and ride comfort performance.  相似文献   

8.
For a single-motor parallel hybrid electric vehicle, during mode transitions (especially the transition from electric drive mode to engine/parallel drive mode, which requires the clutch engagement), the drivability of the vehicle will be signifi- cantly affected by a clutch torque induced disturbance, driveline oscillations and jerks which can occur without adequate controls. To improve vehicle drivability during mode transitions for a single-motor parallel hybrid electric vehicle, two controllers are proposed. The first controller is the engine-side controller for engine cranking/starting and speed synchronization. The second controller is the motor-side controller for achieving a smooth mode transition with reduced driveline oscillations and jerks under the clutch torque induced disturbance and system uncertainties. The controllers are all composed of a feed-forward control and a robust feedback control. The robust controllers are designed by using the mu synthesis method. In the design process, control- oriented system models that take account of various parameter uncertainties and un-modeled dynamics are used. The results of the simulation demonstrate the effectiveness of the proposed control algorithms.  相似文献   

9.
Different from conventional mechanical systems with single degree of freedom (DOF),the main idea of the system of hybrid-driven precision press is to combine the motion of a constant speed motor with a servomotor via a two-DOF mechanism to provide flexible output. In order to make the feasibility clear, this paper studies theoretically the dynamic characteristics of this hybriddriven mechanical system. Firstly,the dynamics model of the whole electromechanical system is set up by combining dynamic equations of DC motors with those of two-DOF nine-bar mechanism deduced by the Lagrange‘s formula. Secondly through the numerical solution with the fourth Runge-Kutta, computer simulation about the dynamics is done, which shows that the designed and optimized hybrid-driven precision press is feasible in theory. These provide theoretical basis for later experimental research.  相似文献   

10.
On the basis of analyzing the system constitution of vehicle semi-active suspension,a 4-DOF(degree of freedom)dynamic model is established.A tunable fuzzy logic controller is designed by using without quantification method and taking into account the uncertainty,nonlinearity and complexity of parameters for a vehicle suspension system.Simulation to test the performance of this controller is performed under random excitations and definite disturbances of a C grade road,and the effects of time delay and changes of system parameters on the vehicle suspension system are researched.The numerical simulation shows that the performance of the designed tunable fuzzy logic controller is effective,stable and reliable.  相似文献   

11.
基于系统动力学理论建立了含被动悬架的汽车半车动力学模型。在MATLAB/Simulink中,集成以白噪声一积分器产生的地面输入,及前、后悬架非簧栽质量模型和车体运动模型,最终实现被动悬架特性仿真的软件编程,为悬架参数的设计和优化提供了技术基础。  相似文献   

12.
自动驾驶汽车作为重点竞争领域将是今后一个时期内国内外汽车工业发展的主流趋势。为使学生更全面地理解并掌握自动驾驶汽车关键技术,研发了自动驾驶汽车硬件在环仿真实验平台(AVHIL)。AVHIL硬件层面集成了实车制动系统、转向系统、传感器系统以及网络通信系统,可提供完整的整车硬件在环实验环境;AVHIL软件层面以MATLAB/Simulink为核心构建快速控制原型算法,基于Pre Scan软件提供虚拟现实界面和环境感知类传感器模块,利用CarSim软件实时运行整车动力学模型。AVHIL为自动驾驶上层控制算法与底层执行机构的开发与测试、高级驾驶辅助系统开发与测试、驾驶员行为特性研究等提供了实时高效的仿真平台,为本科生教学与研究生实践奠定了实验基础。  相似文献   

13.
为使移动小车更好地适应复杂的实际行车道路环境,实现动态障碍物环境下的路径规划,并解决传统人工势场法中的局部最小值问题,提高驾驶安全性,改进传统人工势场法中的障碍物斥力势场模型,并增加了速度斥力势场模型和道路边界约束斥力势场模型,同时将障碍物连锁网络结构与随机目标点法相结合,加入传统人工势场算法中。仿真结果证明了该改进方法的有效性,移动小车能避开局部最小值陷阱到达目标点,实现动态避障路径规划。  相似文献   

14.
基于车联网技术提出了一种无人驾驶汽车设计方案,重点包括道路信息采集、转向和驱动系统的设计、转向控制算法的制定和车联网技术的实现.该无人驾驶汽车实现了汽车的自动行驶功能,同时将无人驾驶汽车嵌入车联网技术,有效地提高了对整个道路系统的监控与管理功能.  相似文献   

15.
为改善汽车的平顺性,将模糊控制算法引入半主动悬架,对其控制系统进行研究。首先以四自由度汽车半主动悬架为研究对象建立了其数学模型与仿真模型;在Matlab中利用模糊逻辑工具箱Fuzzy Toolbox设计了半主动悬架模糊控制器;在此基础上,利用Matlab/Simulink软件搭建半主动悬架模糊控制系统并在白噪声路面及阶跃路面信号激励下进行仿真试验。实验结果表明,所设计的模糊控制器可以有效改善汽车的平顺性并提高汽车的行驶安全性。  相似文献   

16.
对汽车垂直方向振动的分析,对汽车的元件进行合理的简化,建立8自由度动力学模型,给出了模型的质量矩阵、刚度矩阵和阻尼矩阵.根据实际的车型,按比例缩小设计出汽车的振动模拟装置.然后通过凸轮实现路面的模拟输入,利用空气弹簧模拟汽车的内部弹簧元件.根据系统的拉格朗日方程,求解系统8自由度动力学运动微分方程,采用龙格-库塔(Runge-Kutta)法,在Matlab的环境下进行汽车运动求解,得到汽车在不同路面行驶的振动规律.  相似文献   

17.
为获得虚拟场景中车辆真实物理运动和交互性,提出一种基于开放式动力学引擎(ODE)的虚拟仿真平台集成方案.构建具有四自由度的汽车刚体动力学简化模型,分析其ODE特性及刚体连接机理,对车身和车轮之间的悬架系统进行分析,采用ODE中Hinge2进行模拟,分析其刚体动力学方程;基于Quest3D和VS2005进行刚体碰撞检测算法研究,构建一个能实现车辆刚体运动和碰撞检测的虚拟仿真平台,实时对车辆刚体动力学相关参数进行输出.经验证,该虚拟仿真系统具有良好的沉浸感、交互性和实用性.  相似文献   

18.
天津市区机动车实际道路行驶特征的研究   总被引:1,自引:0,他引:1  
利用自行设计的机动车车载实时道路排放测试系统 ,通过实际道路测试 ,获得描述天津市不同类型道路机动车行驶的 15个特征参数 .结果表明 ,ECE 15和FTP 75测试循环与天津市机动车实际道路行驶特征有较大差异 .根据实测结果 ,合成出可真实反映天津市机动车道路行驶特征的测试循环 ,该测试循环可用于实验室中对机动车实际道路排放水平的评价 .  相似文献   

19.
为验证不同种类的交通事故现场处置车辆在不同的停放方式下对交通事故现场的防御效果,采用PC-Crash 12.0中文版软件设计了一种仿真实验。通过模拟误闯入交通事故处置现场的车辆与防御车辆的碰撞,以防御车辆被误闯入车辆撞击后沿道路前进方向运行的距离作为防御效果的评价指标,运行的距离越短,防御效果越好。仿真结果表明:大型车辆的防御效果要明显优于小型车辆;当防御车辆一定时,最佳的防御角度随误闯入车辆的速度增加而减少;当误闯入车辆的速度位于中速(50 km/h)时,防御车辆与道路前进方向的夹角在30°左右时防御效果最佳。  相似文献   

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