A design methodology for mechatronic vehicles: application of multidisciplinary optimization, multibody dynamics and genetic algorithms

A design methodology for mechatronic vehicles is presented. With multidisciplinary optimization (MDO) methods, strongly coupled mechanical, control and other subsystems are integrated as a synergistic vehicle system. With genetic algorithms (GAs) at the system level, the mechanical, control and other relevant parameters can be optimized simultaneously. To demonstrate the feasibility and efficacy of the proposed design methodology for mechatronic vehicles, it is used to resolve the conflicting requirements for ride comfort, suspension working spaces and unsprung mass dynamic loads in the optimization of half-vehicle models with active suspensions. Both deterministic and random road excitations, both rigid and flexible vehicle bodies and both perfect measurement of full state variables and estimated limited state variables are considered. Numerical results show that the optimized vehicle systems based on the methodology have better overall performance than those using the linear quadratic Gaussian (LQG) controller. It is shown that the methodology is suitable for complex design optimization problems where: (1) there is interaction between different disciplines or subsystems; (2) there are multiple design criteria; (3) there are multiple local optima; (4) there is no need for sensitivity analysis for the optimizer at the system level; and (5) there are multiple design variables.     

基于ANSYS的半挂车某承力轴优化设计分析

随着社会需求的不断发展,对特种车的承载能力要求越来越高,而机械结构等的设计越来越轻型化,这对特种车的设计提出了更高的要求,因此需对特种车进行结构优化分析与设计。基于此,针对特种车某承力轴进行优化设计,文章以轴通孔直径和承力面直径为优化参数,在ANSYS中进行模型的建立与分析,得到了较合适的优化参数,为设计人员进行特种车零部件优化设计提供参考。     

Optimization and integration of ground vehicle systems

This article deals with the optimal design of ground vehicles and their subsystems, with particular reference to 'active' safety and comfort. A review of state-of-the-art optimization methods for solving vehicle system design problems, including the integration of electronic controls, is given, thus further encouraging the use of such methods as standard tools for automotive engineers. Particular attention is devoted to the class of methods pertaining to complex system design optimization, as well as approaches for the optimal design of complex systems under uncertainty. Some examples of design optimizations are given in the fields of vehicle system dynamics, powertrain/internal combustion engine design, active safety and ride comfort, vehicle system design and lightweight structures, advanced automotive electronics, and smart vehicles.     

Active roll control for rollover prevention of heavy articulated vehicles with multiple-rollover-index minimisation

This paper presents the application of a nominal control design algorithm for rollover prevention of heavy articulated vehicles with active anti-roll-bar control. This proposed methodology is based on an extension of linear quadratic regulator control for ‘state derivative-induced (control coupled) output regulation’ problems. For heavy articulated vehicles with multiple axles, a performance index with multiple rollover indices is proposed. The proposed methodology allows us to compare the usefulness of various control configurations (i.e. actuators at different axles of the vehicle) based on the interaction of this control configuration with vehicle dynamics. Application of this methodology to a specific heavy articulated vehicle with a tractor semi-trailer shows that a single active anti-roll-bar system at the trailer unit gives better performance than multiple-axle actuators at tractor and trailer together with the single lane change manoeuvre as the external disturbance. Thus, the proposed methodology of this paper not only highlights the importance of the interactions between control and vehicle dynamics in rollover prevention problems but, in fact, proposes a novel technique to exploit the benefits of these interactions judiciously.     

Vehicle suspensions with a mechatronic network strut

This paper applies a novel mechatronic network strut to vehicle suspensions and discusses the benefits of system performance. The proposed mechatronic strut consists of a ball-screw inerter and permanent magnet electric machinery, such that the system impedance can be realised through a combination of mechanical and electrical networks. Applying the mechatronic strut to vehicle suspensions, we evaluate the improvement of system performance using passive electrical networks. Furthermore, a prototype mechatronic strut is constructed for properties verification. Finally, nonlinearities of the mechatronic strut are taken into account to modify the suspension design. From the simulation and experimental results, the proposed mechatronic network strut is shown to be effective.     

A railway vehicle multibody model for real-time applications

Hardware in the loop (HIL) techniques are widely used for fast prototyping of control systems, electronic and mechatronic devices. In the railway field, several mechatronic on board subsystems are often tested and calibrated following the HIL approach. The accuracy of HIL tests depends on how the simulated virtual environment approximates the physical conditions. As the computational power available on real-time hardware grows, the demand for more complex and realistic models of railway vehicles for real-time application increases. In past research activities, the authors worked on the implementation of simplified real-time models for several applications and in particular for an HIL test rig devoted to the type approval of wheel slide protection systems. The activity has then been focused on the development of a three-dimensional model of the dynamics of a railway vehicle for more complex applications. The paper summarises the features and the results of the study.     

Feedforward and Crone Feedback Control Strategies for Automobile ABS

Summary As mechatronic subsystems and especially new emerging technologies for brake systems are more and more developed, a new control architecture for ABS is proposed. The control architecture is designed using both feedback and feedforward controls that command pressure-controlled proportional servo-valves. The methods are developed to compensate for the uncertainty associated with the state of the road surface. The advantages of this strategy compared to the existing ABS strategy are discussed including simulations results using a complete vehicle and brake system model.     

Feedforward and Crone Feedback Control Strategies for Automobile ABS

Summary As mechatronic subsystems and especially new emerging technologies for brake systems are more and more developed, a new control architecture for ABS is proposed. The control architecture is designed using both feedback and feedforward controls that command pressure-controlled proportional servo-valves. The methods are developed to compensate for the uncertainty associated with the state of the road surface. The advantages of this strategy compared to the existing ABS strategy are discussed including simulations results using a complete vehicle and brake system model.     

纯电动汽车动力系统故障分析

随着新能源汽车的发展,纯电动汽车的市场保有量愈来愈高,随着而来的新能源汽车后服市场也逐渐新起。纯电动汽车动力系统是纯电动汽车的核心部件,包括能源系统和驱动系统两个大的子系统。能源系统的主要组成部分为动力电池和动力电池管理系统。驱动系统的主要组成部分为驱动电机及电机控制器。文章归纳总结了动力系统的故障现象,对现象进行故障等级和故障类型的划分。并选取了三个典型案例进行故障排除,为维修人员提供参考。     

借用公交专用道左转的主预信号控制方案优化

设置有路中式公交专用道的交叉口进口道存在因公交与其他车辆两股平行车流在路口同时左转、直行和右转而形成的多路交织现象,传统信号控制方案已无法消除这类交叉口相位放行造成的交织冲突问题。为解决该问题,设计了一种借用公交专用道左转的新型交叉口,规定了各流向车辆的运行规则,同时设计了主信号与预信号相位方案及相互协调配时关系。具体来说,根据公交直行车辆和其他左转、直行车辆的到达-驶离图式,分别建立各流向不同情况下车辆的延误与停车次数计算方法,以交叉口车均延误与车均停车次数加权的当量费用最小为目标,建立交叉口信号配时优化模型。为验证该优化控制策略的有效性,结合算例对传统控制方案和优化控制方案进行比较,并分析等待区长度对车辆排队演化过程的影响,确定优化方案适用场景。结果表明：相对于传统方案,优化方案增加了交叉口的通行能力,使得车均当量费用下降比例达到了32.3%;参数灵敏度分析显示,主信号等待区长度宜设置为80 m。所提出的控制策略通过借用公交专用道左转,提高了交叉口的利用效率,最大限度地降低了对公交优先策略实施的影响,能够完全消除设置有路中式公交专用道交叉口相位放行中的交通交织冲突现象,以保证交叉口行车安全。     

Active yaw damper for the improvement of railway vehicle stability and curving performances: simulations and experimental results

To further increase passenger train comfort and handling performances, a mechatronic approach to the design of railway vehicles is necessary. In fact, active systems on board a railway vehicle allow to push design barriers beyond those encountered with just passive systems. The article deals with the development of an electro-mechanical actuator to improve the running behaviour of a railway vehicle, both in straight track and curve. The main components of the active system are a brushless motor and a mechanical transmission, used to apply a longitudinal force between the carbody and the bogie of the vehicle. The actuator is operated in force control. Different control strategies were developed for straight track running, where the aim is to increase the vehicle critical speed, and for curve negotiation, where the goal is to reduce the maximum values of track shift forces. A mathematical model of the railway vehicle incorporating the active control device has been developed and used to optimise control strategies and hardware set-up of the active device and to estimate the increase in operating performances with respect to a conventional passive vehicle. The active control device has then been mounted on an ETR470 railway vehicle, and its performances have been evaluated during in-line tests in both straight and curved tracks.     

Active yaw damper for the improvement of railway vehicle stability and curving performances: simulations and experimental results

To further increase passenger train comfort and handling performances, a mechatronic approach to the design of railway vehicles is necessary. In fact, active systems on board a railway vehicle allow to push design barriers beyond those encountered with just passive systems. The article deals with the development of an electro-mechanical actuator to improve the running behaviour of a railway vehicle, both in straight track and curve. The main components of the active system are a brushless motor and a mechanical transmission, used to apply a longitudinal force between the carbody and the bogie of the vehicle. The actuator is operated in force control. Different control strategies were developed for straight track running, where the aim is to increase the vehicle critical speed, and for curve negotiation, where the goal is to reduce the maximum values of track shift forces. A mathematical model of the railway vehicle incorporating the active control device has been developed and used to optimise control strategies and hardware set-up of the active device and to estimate the increase in operating performances with respect to a conventional passive vehicle. The active control device has then been mounted on an ETR470 railway vehicle, and its performances have been evaluated during in-line tests in both straight and curved tracks.     

车-路-云融合的智能混合动力汽车节能驾驶技术研究进展与挑战

随着汽车的智能化与网联化,混合动力汽车的节能驾驶技术已由单纯的动力总成能量管理向涵盖车-路-云一体化的综合控制演化,基于车速规划的经济性驾驶与基于路径规划的经济性路由可显著提高汽车的节油率。介绍了现有混合动力汽车的典型节能驾驶技术,指出了节能驾驶技术的商业价值及其节油潜力;归纳总结了经济性驾驶的研究现状,引出了路径规划对于能耗的重要影响;从能耗模型构建、路径优化问题建立和求解算法三方面系统梳理了经济性路由的研究现状,指明了其研究思路;探究讨论了多车混合经济性路由问题,为物流配送车辆的经济性调度提供了优化思路;对混合动力汽车节能驾驶技术的发展趋势进行展望。     

基于多目标粒子群优化算法的某轻型商用车操纵稳定性优化研究

针对某轻型商用车稳态回转时侧倾度偏大的问题对其悬架进行优化改进。基于ADAMS/car搭建整车多体动力学模型,通过前悬架反向平行轮跳试验、后悬架理论计算验证了悬架仿真模型的准确性。进行整车稳态回转工况和转向盘中间位置转向工况仿真分析,结果表明,车身侧倾度偏高。为实现操纵稳定性优化分析的流程自动化,提出了基于modeFRONTIER的联合仿真方法。以悬架设计参数为优化变量,以汽车的侧倾度与横摆角速度响应滞后时间为优化目标,采用拉丁超立方试验设计方法拟合得到混合代理模型,并结合多目标粒子群优化算法对悬架系统进行多目标优化,获得了悬架系统优化方案。优化结果显示,在不影响平顺性的前提下,汽车车身侧倾度降低了13.93%,横摆角速度响应滞后时间降低了2.75%,整车操纵稳定性得到了提升。     

智能网联车辆交通流优化对交通安全的改善

为改善常规驾驶车辆交通流追尾碰撞交通安全状况,提出智能网联车辆（Connected and Automated Vehicles,CAV）与常规车辆构成的混合交通流车队稳定性优化控制方法。基于全速度差模型,应用集成速度与加速度的多前车反馈构建CAV跟驰模型,考虑CAV混合交通流车辆空间分布的随机性,将各类型局部车队稳定性作为优化目标,以局部车队头车速度扰动为系统输入,以尾车速度扰动为系统输出,应用经典控制理论领域的传递函数法推导局部车队稳定性约束条件;分析关于平衡态速度与CAV反馈系数的车队稳定域,以各类型局部车队能够在任意平衡态速度下均稳定为控制目标,对CAV反馈系数输出进行优化控制;设计高速公路上匝道交通瓶颈数值仿真试验,在不同CAV比例等多种条件下,分析CAV混合交通流优化控制对交通流车辆追尾碰撞风险的影响。研究结果表明：CAV混合交通流优化控制可降低车辆追尾碰撞风险,在碰撞时间阈值小于2 s时,100%比例的CAV交通流可将交通流的车辆追尾碰撞风险降低85.81%以上;在碰撞时间阈值大于2 s时,追尾碰撞风险可降低48.22%～78.80%。所提优化控制方法可有效降低CAV车队优化控制的复杂性,为大规模CAV背景下的混合交通流优化控制以及车辆追尾碰撞交通安全提升策略提供直接理论参考。     

长距离大直径泥水盾构隧道洞内无轨运输优化模型研究——以苏通GIL综合管廊工程为例

在无轨运输方式下,随着隧道掘进距离的增长,洞内车辆调度成为制约盾构高效掘进的关键因素。为优化长距离盾构隧道洞内车辆物料运输流程,提高车辆的运输效率,以苏通GIL综合管廊工程为例,对独头掘进5 468 m的长距离泥水盾构隧道进行物料运输优化,并建立长距离隧道车辆无轨运输优化模型。结果表明： 车辆极限运输长度Lmax和车辆投入数目呈正相关关系,投入6辆双头车可以满足本工程独头掘进5 468 m的运输需求; 车辆最长滞留时间相比于原方案减少131 min。该优化模型可为苏通GIL综合管廊工程洞内物料运输方案提供理论指导,并为类似工程提供参考。     

纯电动商用车绝缘故障分析

电动汽车通过高压电能进行整车驱动及附件控制,为保证整车安全性,高压系统均设置有绝缘检测及断电保护功能。文章针对纯电动车辆最受关注的绝缘故障进行原理及故障分析,在设计、装配、使用等环节进行详细原因及排查方案介绍,用于指导市场故障车辆的排查及后期设计方案的优化。     

一种新型电动汽车电控系统示教装置设计

电动汽车的核心技术为“三电”技术,电控系统是电动汽车发展的关键技术之一。本设计以吉利EV450纯电动汽车的电控系统为研究对象,提出优化电动汽车电控系统的研究设计方案,以汽车电器技术为基础,以单片机为核心控制器,设计示教装置电路,实现对该系统的工作原理展示,模拟电动汽车电控系统的运行状态、信号处理及状态监控等功能。     

Active Roll Control of Articulated Vehicles

This paper describes an investigation into active roll control of articulated vehicles. The objective is to minimise lateral load transfer using anti-roll bars incorporating low bandwidth hydraulic actuators. Results from handling tests performed on an articulated vehicle are used to validate a nonlinear yaw/roll model of the vehicle. The methodology used to design lateral acceleration controllers for vehicles equipped with active anti-roll bars is developed using a simplified linear articulated vehicle model. The hardware limitations and power consumption requirements of the active elements are studied. The controller is then implemented in the validated articulated vehicle model to evaluate the performance of an articulated lorry with active anti-roll bars. The simulation results demonstrate the possibility of a significant improvement in transient roll performance of the vehicle, using a relatively low power system (10 kW), with low bandwidth actuators (5 Hz).