共查询到19条相似文献,搜索用时 140 毫秒
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研究了电控闭式空气悬架系统充放气回路结构及工作过程,在对系统进行合理简化的基础上,结合车辆系统动力学和变质量系统热力学理论,对电控空气悬架系统车身高度调节过程中的弹簧内气体热力学过程、簧载质量动力学过程进行了分析,建立了电控闭式空气悬架系统车身高度调节数学模型。针对车身高度调节过程中出现的"过充"、"过放"以及振荡现象,基于神经网络PID控制算法设计了车身高度自适应控制器。为了验证控制系统的实际性能,基于Matlab/Simulink搭建了车身高度控制系统仿真模型,仿真结果表明,所设计的控制器能够有效改善车身高度调节过程出现的不良现象,提高了车身高度控制精度。 相似文献
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为解决电控空气悬架(electric control air suspension,简称ECAS)车身高度切换过程中的振荡及“过充”、“过放”现象,以空气弹簧特性为媒介,与车辆动力学相结合,对车身高度调节系统的进行建模.通过遗传算法优化车身高度调节系统PID的控制参数,提出一种新的积分分离PID控制策略.采用Matlab/Simulink搭建模型并对控制前、后仿真结果进行了对比.结果证明,所设计的控制方法能有效解决以上问题,优化后的车身高度调节系统能显著减少汽车振荡及干扰,操纵稳定性得到改善. 相似文献
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《机械设计与制造》2016,(4)
针对电控空气悬架在车身高度调节过程中存在的过充、过放以及目标值附近的震荡等不良现象,基于AMESim建模与仿真平台建立了单轮ECAS车高调节系统物理模型,准确获取了ECAS在车高调节过程中存在的复杂动态特征,利用Matlab设计了ECAS车高调节模糊自适应控制器,对车高调节过程中进入或流出空气弹簧内的气体质量流量进行准确控制,并进一步采用PWM技术将连续的气体质量流量控制信号转化为离散的高速开关电磁阀直接控制信号,从而实现对ECAS车高调节系统的实时控制。基于AMESim和Matlab进行ECAS车高调节模糊自适应控制器实际控制性能的联合仿真研究,仿真结果表明,所设计的控制器能够实现车身高度的有效调节。 相似文献
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针对一种与开环空气悬架系统充放气回路不同的电控闭环空气悬架系统,介绍它的气路系统的结构和工作原理,以热力学和动力学为基础,系统地建立车高调节过程数学模型和能耗计算方法。通过Simulink仿真,分析车身动态变化规律,计算车高调节过程中的能量消耗量,并与同等条件下电控开环空气悬架系统的能耗进行了比较。仿真结果表明,与开环空气悬架系统相比,该电控闭环空气悬架系统在车高调节过程中需要消耗较多的时间,但是能够节约大量能量。 相似文献
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电子控制空气悬架高度调节过程非线性模型 总被引:6,自引:1,他引:6
电子控制空气悬架的高度调节过程是一个复杂的非线性过程,为研究高度调节过程中对空气弹簧充气或者排气时悬架的动力学特性以及作为后续悬架高度控制策略的研究基础,对电子控制空气悬架高度调节中的弹簧内气体热力学过程、簧载质量动力学过程进行分析,推导出高度调节过程中电磁阀开启期间和关闭后的空气弹簧内压力梯度方程、气体回路的流量方程、以及簧载质量动力学方程,建立带电磁阀功能的高度调节过程非线性模型,并通过电磁阀在不同脉冲时间下空气弹簧充气和排气的整车试验对所建立的高度调节过程模型进行验证,试验结果与仿真结果吻合较好。研究结果表明所建立的模型能正确描述电磁阀关闭前后空气弹簧内的气体状态以及电磁阀关闭以后的悬架在阻尼力作用下运动的迟滞特性。 相似文献
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Long rides on irregular roads and infrastructure problems like uncomfortable seating have a very bad impact on human body. The passengers suffer not only physical pain but also stress related problems. Airsprings gain more popularity in passenger vehicles with an increase in demand for ride comfort. Ride comfort and vehicle handling, being the two critical factors of a suspension system often contradict each other. This led to an extensive research on active automobile suspension systems. The authors of this article propose an innovative design of adaptive air suspension system with LQR control strategy. The proposed LQR controller is tuned by Particle Swarm Optimization. A dynamic model of an air suspension system used in passenger vehicles was designed and simulated for both passive and adaptive systems in MATLAB. An experimental evaluation was done to check the performance of the adaptive air suspension system on a vibration shaker table. Air suspension is a non-linear system and thus the authors have derived a stiffness equation for the same with minimal assumptions. A comparative analysis between the most commonly used PID controller and proposed LQR controller was performed over bumps, potholes and ISO standard random roads in MATLAB. Simulation results showed that adaptive air suspension system improves the ride comfort by reducing the maximum displacement amplitude of the vehicle over random roads by 31% while ensuring the stability of the vehicle by reducing the settling time by 85%. The experimental results of an adaptive air suspension system subjected to random vibrations of frequencies between 5 Hz to 20 Hz, exhibited a reduction of sprung mass acceleration by about 30% demonstrating that the proposed controller is effective for random vibration inputs. 相似文献
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Hierarchical Control of Ride Height System for Electronically Controlled Air Suspension Based on Variable Structure and Fuzzy Control Theory 总被引:3,自引:0,他引:3
《机械工程学报(英文版)》2015,(5)
The current research of air suspension mainly focuses on the characteristics and design of the air spring. In fact, electronically controlled air suspension(ECAS) has excellent performance in flexible height adjustment during different driving conditions. However, the nonlinearity of the ride height adjusting system and the uneven distribution of payload affect the control accuracy of ride height and the body attitude. Firstly, the three-point measurement system of three height sensors is used to establish the mathematical model of the ride height adjusting system. The decentralized control of ride height and the centralized control of body attitude are presented to design the ride height control system for ECAS. The exact feedback linearization method is adopted for the nonlinear mathematical model of the ride height system. Secondly, according to the hierarchical control theory, the variable structure control(VSC) technique is used to design a controller that is able to adjust the ride height for the quarter-vehicle anywhere, and each quarter-vehicle height control system is independent. Meanwhile, the three-point height signals obtained by three height sensors are tracked to calculate the body pitch and roll attitude over time, and then by calculating the deviation of pitch and roll and its rates, the height control correction is reassigned based on the fuzzy algorithm. Finally, to verify the effectiveness and performance of the proposed combined control strategy, a validating test of ride height control system with and without road disturbance is carried out. Testing results show that the height adjusting time of both lifting and lowering is over 5 s, and the pitch angle and the roll angle of body attitude are less than 0.15?. This research proposes a hierarchical control method that can guarantee the attitude stability, as well as satisfy the ride height tracking system. 相似文献
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The control problems associated with vehicle height adjustment of electronically controlled air suspension (ECAS) still pose theoretical challenges for researchers, which manifest themselves in the publications on this subject over the last years. This paper deals with modeling and control of a vehicle height adjustment system for ECAS, which is an example of a hybrid dynamical system due to the coexistence and coupling of continuous variables and discrete events. A mixed logical dynamical (MLD) modeling approach is chosen for capturing enough details of the vehicle height adjustment process. The hybrid dynamic model is constructed on the basis of some assumptions and piecewise linear approximation for components nonlinearities. Then, the on-off statuses of solenoid valves and the piecewise approximation process are described by propositional logic, and the hybrid system is transformed into the set of linear mixed-integer equalities and inequalities, denoted as MLD model, automatically by HYSDEL. Using this model, a hybrid model predictive controller (HMPC) is tuned based on online mixed-integer quadratic optimization (MIQP). Two different scenarios are considered in the simulation, whose results verify the height adjustment effectiveness of the proposed approach. Explicit solutions of the controller are computed to control the vehicle height adjustment system in realtime using an offline multi-parametric programming technology (MPT), thus convert the controller into an equivalent explicit piecewise affine form. Finally, bench experiments for vehicle height lifting, holding and lowering procedures are conducted, which demonstrate that the HMPC can adjust the vehicle height by controlling the on-off statuses of solenoid valves directly. This research proposes a new modeling and control method for vehicle height adjustment of ECAS, which leads to a closed-loop system with favorable dynamical properties. 相似文献
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The accurate control for the vehicle height and leveling adjustment system of an electronic air suspension(EAS) still is a challenging problem that has not been effectively solved in prior researches. This paper proposes a new adaptive controller to control the vehicle height and to adjust the roll and pitch angles of the vehicle body(leveling control) during the vehicle height adjustment procedures by an EAS system. A nonlinear mechanism model of the full?car vehicle height adjustment system is established to reflect the system dynamic behaviors and to derive the system optimal control law. To deal with the nonlinear characters in the vehicle height and leveling adjustment processes, the nonlinear system model is globally linearized through the state feedback method. On this basis, a fuzzy sliding mode controller(FSMC) is designed to improve the control accuracy of the vehicle height adjustment and to reduce the peak values of the roll and pitch angles of the vehicle body. To verify the effectiveness of the proposed control method more accurately, the full?car EAS system model programmed using AMESim is also given. Then, the co?simulation study of the FSMC performance can be conducted. Finally, actual vehicle tests are performed with a city bus, and the test results illustrate that the vehicle height adjustment performance is effectively guaranteed by the FSMC, and the peak values of the roll and pitch angles of the vehicle body during the vehicle height adjustment procedures are also reduced significantly. This research proposes an effective control methodology for the vehicle height and leveling adjustment system of an EAS, which provides a favorable control performance for the system. 相似文献
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ECAS系统控制模式及控制策略 总被引:4,自引:0,他引:4
为了提高汽车平顺性和操纵稳定性,引入ECAS/ESAC系统,将决策控制做为空气悬架系统的控制策略,再根据对悬架偏频大小的要求和空气弹簧刚度特性,逆推出空气弹簧高度的结果调节范围,根据车速确定高度的控制策略,通过遗传算法的优化实现弹簧刚度与减振器阻尼的匹配,根据匹配结果最终确定阻尼的控制模式和控制策略。分别利用非线性系统半车动力学模型和蛇形试验仿真在此系统下的汽车平顺性和操纵稳定性。仿真结果及试验表明:在随机路面条件下,由于控制策略的实施,空气悬架系统的平顺性和操纵稳定性均有所提高。 相似文献
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自适应模糊控制方法在主动悬挂系统中的应用研究 总被引:3,自引:2,他引:1
提出了一种主动悬挂系统的自适应模糊控制方法 ,该模糊控制方法可以在线自适应调整模糊控制的有关参数。 1/ 4车辆模型作为仿真对象 ,模糊控制器可以显著地减小车辆的振动及干扰 ,提高车辆的舒适性。仿真结果表明该模糊控制方法的有效性。另外 ,当主动悬挂系统模型参数发生变化时该模糊控制器表现出良好的鲁棒性 相似文献