Study on Steering Control Strategy for High-Speed Tracked Vehicle with Hydrostatic Drive

Steering control strategy for high-speed tracked vehicle with hydrostatic drive is designed based on analyzing the fundamental steering theories of the hydrostatic drive tracked vehicle. The strategy is completed by the cooperation between integrated steering control unit and pump & motor displacement controller. The steering simulation is conducted by using Simulink of Matlab. It is indicated that this steering control strategy can reduce the average vehicle speed automatically to achieve the drivers expected steering radius exactly in the case of ensuring not exceeding the system pressure threshold and no sideslip.     

Low-Power Operational Amplifier for Real-Time Signal Processing System of Micro Air Vehicle

A low-power complementary metal oxide semiconductor(CMOS) operational amplifier (op-amp) for real-time signal processing of micro air vehicle (MAV) is designed in this paper. Traditional folded cascode architecture with positive channel metal oxide semiconductor(PMOS) differential input transistors and sub-threshold technology are applied under the low supply voltage. Simulation results show that this amplifier has significantly low power, while maintaining almost the same gain, bandwidth and other key performances. The power required is only 0.12mW, which is applicable to low-power and low-voltage real-time signal acquisition and processing system.     

Vehicle Dynamics Modeling and Simulation for ACC

A 7 degree-of-freedom (DOF) 4 wheels vehicle dynamics model based on Matlab-Simulink is established,and 7 DOF vehicle dynamics equations in the form of nonlinear state-space standards are given.The characters of the electronic throttle and the active braking system have been analyzed.And the electronic throttle model and the active braking system model are built according to the test results respectively.Off-line simulation results indicate that the model is suitable for the vehicle adaptive cruise control ...     

Robust parametric approach for tracking control of an air-breathing hypersonic cruise vehicle

To realize the stabilization and the tracking of flight control for an air-breathing hypersonic cruise vehicle, the linearization of the longitudinal model under trimmed cruise condition is processed firstly. Furthermore, the flight control problem is formulated as a robust model tracking control problem. And then, based on the robust parametric approach, eigenstructure assignment and reference model tracking theory, a parametric optimization method for robust controller design is presented. The simulation results show the effectiveness of the proposed approach.     

基于自适应滑模控制的智能车车道保持分析

针对目前智能车车道保持控制算法对参数摄动适应性不足的问题,提出一种基于模糊自适应调节的滑模控制方法。在建立车辆线性二自由度动力学模型的基础上,采用滑模变结构控制来提高车道保持控制器对参数摄动和未建模动态的适应性;利用模糊控制自适应调节滑模面的切换增益,降低控制抖振。仿真分析表明,提出的方法不仅能够显著降低传统滑模变结构控制器的抖振,而且对参数摄动和未建模动态具有较高的鲁棒性和适应性。     

基于视觉导航的智能小车调速控制器设计

智能小车控制是构建智能车路系统中汽车列队行驶模拟系统的基础。针对智能小车自主寻迹问题,通过对寻迹路径的偏差及偏差的导数进行模态划分,提出对应的模糊控制规则,进而以DSP TMS320F2812为主控芯片控制智能小车电机的转速,实现智能小车纵向自主控制。模型车运行实验表明智能小车速度调节算法可行。     

重型车辆双路制动液压系统性能仿真

对重型车辆电液伺服控制双路制动器系统进行了分析与设计。采用电液伺服控制的双联制动阀控制双腔制动油缸的双路制动方案,实现车辆的行车制动和紧急制动。通过分析制动器系统各组成模块和连接管路对制动性能的影响,建立了制动器系统的非线性数学模型。应用MATLAB/Simulink对系统的双路行车制动性能进行了仿真研究,验证了设计方案的合理性。台架试验表明:所设计的制动器液压系统的性能达到了设计要求。     

汽车稳定性控制中横摆力矩决策的LQR方法

综合跟随理想横摆角速度的方法和抑制汽车质心侧偏角的汽车稳定性控制方法,提出了一种新的最优控制方法。以线性二自由度车辆操纵特性模型为控制目标,基于汽车横摆力矩与车辆状态偏差之间的动力学关系建立了控制系统模型。采用线性二次型调节器(LQR)方法进行了汽车横摆力矩的决策,实现了汽车稳定性控制。在硬件与驾驶员在环仿真试验台上的试验验证了LQR方法的控制性能。     

基于“概念悬架”的某微型车的建模与仿真

在ADAMS/Car下,基于"概念悬架"模块搭建了14自由度整车动力学模型,模型的动力学仿真结果与实车试验数据有较好的一致性。利用该模型分析了前悬架中的各项特性对该车不足转向度的贡献;该车的前悬架的C特性对不足转向特性的影响最为突出。最后文章进行了前悬架KC特性改变对整车操纵稳定性影响的分析,介绍了一种由整车性能分解到悬架性能的思路。     

模态密度计算精度对车内噪声预测精度的影响

阐述了模态密度的基本理论,给出了曲面曲率变化时模态密度的半经验计算公式。建立了某国产轿车的统计能量分析模型,计算了各简化子系统的模态密度,并采用FEA方法对车身各子系统的模态密度进行了计算,将简化子系统时计算的模态密度与FEA计算的模态密度进行了对比分析。分析预测了车速为100km/h时车内驾驶员耳旁噪声的1/3倍频程频谱,并将采用简化子系统计算模态密度时的车内噪声1/3倍频程频谱和采用FEA方法计算模态密度时的车内噪声1/3倍频程频谱分别与试验测量结果进行了对比,分析了各子系统模态密度的计算精度对车内噪声预测精度的影响。结果表明,准确获取车身各个子系统的模态密度可以有效地提高SEA模型预测精度,使车内噪声预测误差在1dB(A)以内,满足工程上在汽车产品开发设计阶段对车内中高频噪声分析预测的要求,可为汽车产品开发设计阶段的声学设计提供参考。