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1.
汽车磁流变半主动悬架的模糊控制   总被引:1,自引:0,他引:1  
为带有磁流变液智能阻尼器的半主动汽车悬架系统设计了一种模糊控制器:将半主动悬架相对位移的误差及误差变化率作为模糊控制器的输入,阻尼力作为其输出,利用磁流变液智能阻尼器的阻尼力随电流变化的特性使车身的振动降到最小。仿真实验给出了最优被动悬架和模糊控制智能半主动悬架在随机路面激励情况下的响应曲线,结果表明,磁流变半主动悬架系统采用模糊控制效果较理想,其车身垂直加速度等参数变化幅度也有所降低。  相似文献   

2.
以车辆悬架系统为研究对象,建立了1/4车辆模型。在路面不平度和发动机惯性力及其转矩两种输入同时存在的条件下,运用遗传算法对悬架参数进行了优化设计。最后对比了优化前后悬架的性能指标(车身加速度、悬架动挠度、车轮动变形),车身加速度改进后(0.94249 m/s2)比改进前(1.52236m/s2)的均方根值降低了约38%,对比结果表明通过本文方法实现的悬架最优化设计对改善车辆的乘坐舒适性及平顺性是有效的。  相似文献   

3.
基于部分错位反馈控制和全错位反馈控制法,研究一个新的五维混沌Chen系统的混沌控制问题.利用Routh-Hurwitz准则对受控系统进行了稳定性分析,获得达到控制目标时控制器系数的选择范围.数值模拟表明:这2种方法能够有效地控制混沌系统到稳定点,且全错位反馈控制方法具有更好的优良性.  相似文献   

4.
为进一步改善车辆座椅乘坐舒适性,设计了3种分别基于负刚度结构单元(NSE)、阻尼结构单元(DE)及负刚度-阻尼单元(NSDE)的座椅悬架系统.建立了座椅悬架动力学模型,以悬架位移幅和座椅加速度的均方根值为评价目标,考察了不同设计参数对座椅乘坐舒适性的影响特性,并利用遗传算法对悬架设计参数进行了优化分析.研究结果表明:基于NSE和DE单元的悬架设计参数对评价目标的影响较大,通过参数优化分析发现DE的阻尼力比NSE的恢复力低98.3%,说明DE结构单元对改善座椅隔振性能作用有限.但引入NSE结构单元后,NSDE悬架系统的振动位移幅和座椅加速度的均方根值明显减小,有效提升了座椅的隔振效果,提高了驾驶员的乘坐舒适性.  相似文献   

5.
为了优化被动分数阶电动汽车悬架的参数,引入车身振动加速度、悬架动挠度、轮胎动载荷和电机垂直加速度这4个平顺性指标,建立含分数阶被动控制悬架系统的三自由度1/4电动汽车非线性模型.利用蒙特卡洛(Monte Carlo)算法对悬架参数的不确定性进行仿真及灵敏度分析,并选取灵敏度高的参数,采用改进的粒子群优化(particl...  相似文献   

6.
以1/4车辆模型为研究对象,建立了以悬架刚度和阻尼为设计变量,以车身加速度和车轮动变形两者最小为目标函数的多目标优化问题,在路面不平度输入的条件下,运用遗传算法和并列选择方法对问题进行求解。最后对比了优化前后悬架的性能指标(车身加速度、悬架动挠度、车轮动位移),车身加速度优化后比优化前的均方根值降低了约44%,轮胎动位移优化后比优化前的均方根值降低了约11%,对比结果表明通过本文方法实现的悬架最优化设计对改善车辆的乘坐舒适性及稳定性是有效的。  相似文献   

7.
本文以车辆主动悬架系统为研究对象,建立了1/4车辆模型,在此基础上建立simulink模型,并设计了PID控制器,然后运用遗传算法对相关参数进行了优化设计,实现了主动悬架的最优PID控制.最后对比了主、被动悬架的性能指标(车身加速度、悬架动挠度、车轮动位移),结果表明通过本文方法实现的最优PID控制器对于改善车辆的行驶平顺性和稳定性是有效的.  相似文献   

8.
为了改善驾驶室座椅的隔振性能,提出了基于负刚度结构的工程机械驾驶室座椅悬架系统优化模型.通过设计座椅负刚度悬架结构(NSS),建立了负刚度非线性动力学方程,基于MATLAB对悬架系统的不同参数及其对动刚度的影响进行了分析,得到悬架系统最为理想的配置参数范围;同时提出了NSS优化模型,采用不同方法对振动传递特性进行了仿真分析.研究结果表明:优化后的座椅悬架系统的位移幅值与加速度幅值均明显减小,座椅垂直振动方向的四次功率振动剂量值与加权加速度均方根值分别下降了86%和87%,座椅有效振幅传递率和悬架系统振动传递率均下降,传递给驾驶员的振动的峰值频率均不在容易引起人体不适的关键频率值附近.这表明座椅悬架系统的设计对驾驶员受振后的身体健康状况没有任何影响,NSS悬架系统具有良好的隔振性能,提高了驾驶员的乘坐舒适度.  相似文献   

9.
以汽车半主动悬架为研究对象,建立了汽车二自由度1/4车体模型,提出了一种汽车半主动悬架的神经网络控制方法,设计了神经网络控制器,并利用MATLAB进行仿真。仿真结果表明,该神经网络控制器用于半主动悬架的车身加速度和车身重心高度位移控制是行之有效的。  相似文献   

10.
根据车辆横向运动动力学模型,采用全反馈控制策略,并考虑到人的差异,提出了影响控制策略的组合系数,可以通过人为地选择组合系数,来调整转向传动比和转向增益.仿真结果表明,可使质心侧偏角降低到零而侧向加速度增益和横摆角速度增益保持不变,并能减少系统波动幅值和进入稳态所经历的时间,从而保证车辆的反应快速灵活.在保持上述特性不变的情况下,可人性化地选择转向传动比和转向增益,进一步提高了车辆的操纵稳定性、行驶安全性和司机的驾驶舒适性.  相似文献   

11.
An optimization method for time-delayed feedback control of partially observable linear building structures subjected to seismic excitation is proposed. A time-delayed control problem of partially observable linear building structure under horizontal ground acceleration excitation is formulated and converted into that of completely observable linear structure by using separation principle. The time-delayed control forces are approximately expressed in terms of control forces without time delay. The control system is then governed by Itoe stochastic differential equations for the conditional means of system states and then transformed into those for the conditional means of modal energies by using the stochastic averaging method for quasi-Hamiltonian systems. The control law is assumed to be modal velocity feedback control with time delay and the unknown control gains are determined by the modal performance indices. A three-storey building structure is taken as example to illustrate the proposal method and the numerical results are confirmed by using Monte Carlo simulation.  相似文献   

12.
The least means squares (LMS) adaptive filter algorithm was used in active suspension system. By adjusting the weight of adaptive filter, the minimum quadratic performance index was obtained. For two-degree-of-freedom vehicle suspension model, LMS adaptive controller was designed. The acceleration of the sprung mass,the dynamic tyre load between wheels and road,and the dynamic deflection between sprung mass and unsprung mass were determined as the evaluation targets of suspension performance. For LMS adaptive control suspension, compared with passive suspension, acceleration power spectral density of sprung mass acceleration under the road input model decreased 8-10 times in high frequency resonance band or low frequency resonance band. The simulation results show that LMS adaptive control is simple and remarkably effective. It further proves that the active control suspension system can improve both the riding comfort and handling safety in various operation conditions, and the method is fit for the active control of the suspension system.  相似文献   

13.
采用某A级车的前悬架参数,建立完整的悬架模型,并对该悬架系统进行仿真与优化。详细说明悬架系统建立和仿真的方法,并具体分析了悬架参数改变对汽车操纵稳定性的影响。优化分析结果表明,通过进一步进行悬架优化设计,汽车的操纵稳定性得到提高。  相似文献   

14.
We studied the response of harmonically and stochastically excited strongly nonlinear oscillators with delayed feedback bang-bang control using the stochastic averaging method. First, the time-delayed feedback bang-bang control force is expressed approximately in terms of the system state variables without time delay. Then the averaged It6 stochastic differential equations for the system are derived using the stochastic averaging method. Finally, the response of the system is obtained by solving the Fokker-Plank-Kolmogorov (FPK) equation associated with the averaged lt6 equations. A Duffing oscillator with time-delayed feedback bang-bang control under combined harmonic and white noise excitations is taken as an example to illus- trate the proposed method. The analytical results are confirmed by digital simulation. We found that the time delay in feedback bang-bang control will deteriorate the control effectiveness and cause bifurcation of stochastic jump of Duffing oscillator.  相似文献   

15.
为了获得更好的汽车平顺性,构建1/4汽车主动悬架模型,采用悬架动挠度、车身动位移、轮胎动载荷和轮胎垂直速度等4项指标进行近似衡量,提出基于改进萤火虫优化算法(FA)的汽车悬架PID控制,并与基于LQR控制、基于Fuzzy-PID控制下的汽车悬架平顺性进行对比。仿真结果显示,基于改进FA优化的PID控制的4项指标峰值均大幅降低,峰值最高下降36.1%,证明基于改进萤火虫优化算法的PID控制可提高汽车平顺性能。  相似文献   

16.
This paper presents the development of a proportional-integral-derivative (PID)-based control method for application to active vehicle suspension systems (AVSS). This method uses an inner PID hydraulic actuator force control loop, in combination with an outer PID suspension travel control loop, to control a nonlinear half-car AVSS. Robustness to model uncertainty in the form of variation in suspension damping is tested, comparing performance of the AVSS with a passive vehicle suspension system (PVSS), with similar model parameters. Spectral analysis of suspension system model output data, obtained by performing a road input disturbance frequency sweep, provides frequency response plots for both nonlinear vehicle suspension systems and time domain vehicle responses to a sinusoidal road input disturbance on a smooth road. The results show the greater robustness of the AVSS over the PVSS to parametric uncertainty in the frequency and time domains.  相似文献   

17.
针对电力市场中一类非线性博弈模型的混沌问题,通过加入脉冲时间延迟反馈控制,对其稳定性进行研究。第一种形式是对一家投资商引入系统变量的时间延迟反馈控制法,第二种形式是对整个系统引入系统变量的时间延迟反馈控制,并利用Matlab软件对该系统进行数值模拟,验证该方法的有效性。结果表明:时间延迟反馈控制可以有效控制系统的稳定性。  相似文献   

18.
本文研究变周期采样的网络控制系统模型的随机最优反馈控制。假设网络诱导延时服从某一个区间的均匀分布,设计一个依赖延时的状态反馈控制器,使得所建立的变周期采样的NCS模型指数均方稳定。利用动态规划思想结合Bellman方程通过优化所给定的性能指标,得到了随机最优反馈控制器设计方法,并通过仿真实例验证了本章提出方法的有效性。  相似文献   

19.
To improve the suspension performance and steering stability of light vehicles, we built a kinematic simulation model of a whole independent double-wishbone suspension system by using ADAMS software, created random excitations of the test platforms of respectively the left and the right wheels according to actual running conditions of a vehicle, and explored the changing patterns of the kinematic characteristic parameters in the process of suspension motion. The irrationality of the suspension guiding mechanism design was pointed out through simulation and analysis, and the existent problems of the guiding mechanism were optimized and calculated. The results show that all the front-wheel alignment parameters, including the camber, the toe, the caster and the inclination, only slightly change within corresponding allowable ranges in design before and after optimization. The optimization reduces the variation of the wheel-center distance from 47.01 mm to a change of 8.28 mm within the allowable range of -10 mm to 10 mm, promising an improvement of the vehicle steering stability. The optimization also confines the front-wheel sideways slippage to a much smaller change of 2.23 mm; this helps to greatly reduce the wear of tires and assure the straight running stability of the vehicle.  相似文献   

20.
根据汽车白车身结构有限元模型建立车身声固耦合模型。基于声学模态分析理论,进而求解声腔模态。通过实车怠速噪声和车身悬置激励力测试车内响应点的声压值,进一步验证声固耦合模型。通过峰值频率下的板块单元贡献量和模态应变能优化分析,汽车车内低频噪声降低,有利于提升汽车的NVH性能。  相似文献   

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