共查询到20条相似文献,搜索用时 31 毫秒
1.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(2):143-150
Expressions are derived for the numerical computation of rms values for control force, suspension stroke and dynamic tyre deflection in a quarter-car vehicle model on a random road of given roughness. A quadratic performance index is employed and the effects of the assumed weighting factors on the rms values and overall static stiffness determined. 相似文献
2.
RMS Values for Force, Stroke and Deflection in a Quarter-car Model Active Suspension with Preview 总被引:1,自引:0,他引:1
A. G. Thompson C. E. M. Pearce 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2003,39(1):57-75
Summary In the case of a quarter-car vehicle model incorporating an active suspension, the addition of preview to the system necessitates finding new techniques for the direct computation of rms values for control force, suspension stroke and tyre deflection on a random road. Here we obtain these rms values from the performance index components as derived analytically by means of matrix operations requiring the solution of Lyapunov equations and the use of similarity transformations. Some numerical examples and MATLAB programs are included. 相似文献
3.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(3):245-253
Summary Matrix expressions are developed for the direct computation of rms values for the optimal control forces, front and rear suspension strokes and dynamic tyre deflections in a half-car model on a random road of given roughness. A quadratic performance index is employed with assumed weighting factors and evaluated in the same computation. 相似文献
4.
A. G. Thompson B. R. Davis 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2003,39(3):245-253
Summary Matrix expressions are developed for the direct computation of rms values for the optimal control forces, front and rear suspension strokes and dynamic tyre deflections in a half-car model on a random road of given roughness. A quadratic performance index is employed with assumed weighting factors and evaluated in the same computation. 相似文献
5.
海沧大桥悬索桥施工控制测量 总被引:4,自引:3,他引:4
针对海沧大桥悬索桥的施工特点,对施工测量控制网的建立、主塔的变形观测及主缆基准索股线形的控制测量方法进行了研究。提出的方法有效地解决了海沧大桥的施工控制测量问题,具有一定的工程使用价值。 相似文献
6.
7.
A. Stensson C. Asplund L. Karlsson 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1994,23(1):85-106
Three nonlinear models of a MacPherson strut wheel suspension have been studied. The nonlinearities considered are due to the nonlinear geometrical effects in the mechanism, the amplitude limitation due to the bumpstop, the progressive stiffness of the bumpstop and the different damping coefficients for the shock absorber in bump and rebound. The models have been derived according to physical parameter values of. the MacPherson strut wheel suspension of the car SAAB 9.000. The most suitable model was further studied with special attention to nonlinear phenomena. For harmonic forcing the system had phenomena such as multiple solutions and subharmonics. For some parameter values the solution was very sensitive to changes in the integration tolerances in the numerical integration routine. No chaotic steady state solutions were found for the parameter values studied. 相似文献
8.
9.
10.
11.
M. A. H. Van Der J. H. E. A. Muijderman F. E. Veldpaus 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1997,28(4):307-323
Controllers for semi-active suspensions have to account for constraints on damper range, tire force and suspension travel. Two approaches to incorporate these constraints in the design of controllers to minimize peak values in the chassis acceleration are considered. It is assumed that information on the oncoming road elevations (preview) is available. In the soft constraint approach, the constraints on tire force and suspension travel are included in a quadratic performance index. Two clipped optimal control laws, which deal with preview in a different way, are presented. Simulation results with a 2-DOF vehicle model on some rounded pulses show that these laws do not work satisfactorily with respect to the constraints. Therefore, the control problem is reformulated as a constrained optimization problem with hard constraints on tire force and suspension travel. Simulations with the same model on the same rounded pulses show that the hard constraint approach handles the constraints more properly. 相似文献
12.
洪塘大桥位于福州西郊,跨越乌龙江,需原桥位拓宽改建,新建主桥采用自锚式悬索桥。基于施工期间保通车的民生要求,提出了三阶段横向拼接施工的设计方案,建成了国内第一座在改建工程中实现保通车目标的自锚式悬索桥。首次提出了主缆平弯锚固方案,改善了主缆锚固区的管养条件。采用有限元程序对桥梁运营及施工过程中的关键工序进行仿真分析,根据分析结果指导施工和施工控制,现场监测数据表明计算值与实测值相符。 相似文献
13.
14.
Optimization for Vehicle Suspension II: Frequency Domain 总被引:4,自引:0,他引:4
J.M. Del Castillo Research Assistant P. Pintado Assistant Professor F.G. Benitez Professor 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1990,19(6):331-352
The objective of this study is optimizing the components design of a vehicle suspension system under excitation due to road roughness. The vehicle is modelled as a dynamic system made of masses interconnected by, linear, springs and dampers. The optimizing code provides values corresponding to the caracteristics of masses, dampers and springs which, within a range, minimize the objective function for a defined excitation. This objective function auantifies the vehicle comfort level.
The optimization method used is the sequential linear programming by iteratively applying the Simplex algorithm. The model response is obtained in frequency domain and the vehicle excitation can be either random or deterministic.
The exact nature of the optimization problem, objective function and restrictions, depend on the type of excitation considered.
In succeeding paragraphs, the problem formulation together with a comparison with other authors is presented. 相似文献
The optimization method used is the sequential linear programming by iteratively applying the Simplex algorithm. The model response is obtained in frequency domain and the vehicle excitation can be either random or deterministic.
The exact nature of the optimization problem, objective function and restrictions, depend on the type of excitation considered.
In succeeding paragraphs, the problem formulation together with a comparison with other authors is presented. 相似文献
15.
Optimization for Vehicle Suspension I: Time Domain 总被引:4,自引:0,他引:4
P. Pintado Assistant Professor F.G. Benitez Professor 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1990,19(5):273-288
A numerical procedure for finding the optimum values of a number of parameters describing a model vehicle suspension has been studied. The vehicle has been modelled by dynamic systems of linear springs and dampers, and the goal is to obtain lower acceleration peaks at an elected design point in the vehicle.
The problem is stated as a mathematical programming problem which can be solved by means of the sequential linear programming technique. The procedure has been implemented for a four wheel independent suspension model capable of being subjected to road irregularities and to centrifugal and braking accelerations. 相似文献
The problem is stated as a mathematical programming problem which can be solved by means of the sequential linear programming technique. The procedure has been implemented for a four wheel independent suspension model capable of being subjected to road irregularities and to centrifugal and braking accelerations. 相似文献
16.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(5):273-288
SUMMARY A numerical procedure for finding the optimum values of a number of parameters describing a model vehicle suspension has been studied. The vehicle has been modelled by dynamic systems of linear springs and dampers, and the goal is to obtain lower acceleration peaks at an elected design point in the vehicle. The problem is stated as a mathematical programming problem which can be solved by means of the sequential linear programming technique. The procedure has been implemented for a four wheel independent suspension model capable of being subjected to road irregularities and to centrifugal and braking accelerations. 相似文献
17.
18.
为了对悬索桥服役期间损坏的长吊索进行快速更换,依托润扬大桥南汊悬索桥1对长吊索火灾后紧急更换的工程案例,结合既有吊索锚固构造,设计一种悬索桥长吊索更换装置,开发传统吊索更换须在吊索无应力状态下拆除转换为吊索在有限应力而销轴无应力状态下拆除的吊索更换技术。详细介绍施工过程及施工关键步骤,并采用ANSYS建立全桥有限元模型,对吊索更换过程中的7个关键施工步骤进行仿真模拟,分析更换过程中待更换吊索索力、相邻吊索索力、主缆竖向位移、加劲梁竖向位移等指标的变化趋势。同时,对不中断交通情况下的施工全过程进行监控,实测施工过程中分级张拉临时吊索,安装新吊索、拆除临时索等工况的相应吊索索力以及临时吊索索夹与永久吊索索夹的相对滑移。研究结果表明:实测值与模拟值变化趋势基本吻合,验证了施工方案的合理性;该桥长吊索的成功更换,验证了所开发的吊索更换装置的可靠性,不仅完成了在不中断交通情况下的吊索更换,而且还实现了对悬索桥既有状态干扰最小的目标。 相似文献
19.
William N. Patten Jian Pang 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1998,30(1):55-68
A low-order, lumped parameter model is proposed to describe the vertical vibration compliance of an automotive seat. The model includes nonlinear stiffness and damping effects that mimic the properties exhibited by open cell foams that are commonly used in the construction of an automotive seat cushion. A shaped sandbag was positioned on a seat cushion and vibrated to obtain test data. White noise acceleration with amplitude ranging from 0.05 g rms to 0.45 g rms in increments of 0.05 g rms was used to excite the seat track. A luxury car seat and a sports car seat were tested and a nonlinear seat model was identified that predicts the actual test data with fidelity. The paper demonstrates that once a family of model parameters is identified for a particular seat, then the model can be used for a wide spectrum of seat track inputs. Additional experiments also verified that when the sandbag mass was increased by as much as 50%, the predicted response using the proposed model was in agreement with the measured response. Finally, the paper reports the result of an experiment using a human subject on a seat cushion. A simulation using the new cushion model and an ISO vibration model of a seated human produced response data that was very similar to the actual test data. 相似文献