磁流变阀控半主动悬架汽车瞬态动力学特性及协调控制研究

Low carbon and intellectualization is the primary direction of the vehicle development nowadays. This requires the suspension to effectively isolate the vibration and meanwhile guarantee the grip performance of the tires. Last few years have witnessed the increasing interests in the development of the semi-active suspension, the application of which makes it easier to compromise between the handling, ride comfort, and additional energy consumption. However, unsolved technical issues, such as the manufacturing of the traditional throttle and the slow response of the actuator, greatly restrict the commercial application of the semi-active suspension. Magneto-rheological (MR) dampers are potentially employed to solve the aforementioned problems. However, large demand of MR fluid increases the cost and MR dampers are mostly applied in luxury vehicles. Hence, an efficient actuator design and its coordinated control with consideration of the integral vehicle dynamic performance, with improving the vehicle performance and decreasing the cost, become the prominent problems which are urgent to be saluted..At present, control of semi-active suspension is generally based on the vehicle steady state characteristics without considering the suspension K&C characteristics and tire transient performance with varying speed and dynamic loads. Lack of research on the vehicle transient response becomes the key obstacle of the semi-active suspension coordinated control with in terms of both the handling and the ride comfort..To improve the integral performance of the vehicle, the research presented in this proposal focuses on the vehicle transient dynamics with the MR valve controlled (MRVC) semi-active suspension and it coordinated control, which includes the following key points: (1) vehicle transient dynamics with MRVC semi-active suspension; (2) the methodology on top-down synthesized optimal design of the MRVC damper; (3) online identification on vehicle operating conditions via fusion of road input information and vehicle states; (4) adaptive coordinated control strategy of the MRVC semi-active suspension. The major contributions of this proposal lies in the studying of mechanism of tire carcass deformation and tire relaxation effect with varying speed and dynamic loads, extending the application of the tire transient characteristic theoretical model under complex combined conditions. Secondly, the vehicle transient dynamics, affected by tire transient characteristic and suspension K&C characteristics, is predicted precisely online. This promotes taking advantage of the tire adhesion limit and expanding vehicle stability boundary completely, which provides the theoretical basis to the semi-active suspension design and analysis. In addition, a model predictive control algorithm adapting with vehicle operating conditions, considering the saturation and reconfiguration time of each MRVC damper, is proposed to obtain the globally sub-optimal solution online, which provides a theoretical basis and practical methods for the MRVC semi-active suspension cooperative control to improve the vehicle transient performance，promoting the low carbon and intellectualization of vehicles development.

半主动悬架能高效衰减振动并保证轮胎抓地力，且能耗小，是当前热点，但其与整车集成的瞬态动力学特性的实时描述及协调控制亟须解决。本项目拟采用系统与综合、理论与试验相结合的方法研究磁流变阀控半主动悬架汽车瞬态动力学特性及协调控制，主要包括：1)磁流变阀控半主动悬架汽车瞬态动力学特性；2)磁流变阀控减振器正向综合优化设计；3)融合路面信息与车身状态的汽车运行工况的在线识别；4)工况自适应半主动悬架协调控制策略。其贡献是阐明含时变速度和动态载荷影响的胎体耦合变形机理及轮胎松弛效应，揭示轮胎瞬态特性及悬架K&C特性对汽车瞬态动力学特性的影响规律，可在线预测轮胎特性及汽车动力学特性，为充分利用轮胎附着极限并拓宽汽车稳定边界奠定基础，为半主动悬架设计和分析提供理论依据；建立含约束及时滞影响的滚动优化控制方法，可在线获得全局近优解，为磁流变阀控半主动悬架汽车的协调控制提供支撑，促进汽车低碳化智能化的发展。

汽车的低碳化、智能化对悬架性能要求不断提升。半主动悬架能够高效衰减振动并保证轮胎抓地力，且能耗低，是当前热点。目前半主动悬架与整车集成的研究多重点关注汽车稳态特性，缺乏对瞬态特性的细致考虑，对车辆状态的观测、稳定边界的获取、轮胎力的预测及分配等需要车辆模型的动力学控制带来严重影响。本项目重点研究了磁流变阀控半主动悬架汽车瞬态动力学特性、磁流变阀控减振器正向综合优化设计方法、路面特征与车身状态的在线识别、磁流变阀控半主动悬架汽车瞬态动力学特性的协调控制策略，取得的主要结果和意义如下。.1) 建立了汽车瞬态动力学特性实时模型。揭示轮胎瞬态特性规律，刻画悬架系统引入的运动学和动力学耦合行为，实时描述磁流变阀控半主动悬架汽车瞬态动力学特性；建立汽车动力学性能虚拟主观评价方法，获得了操纵稳定性评价的12个核心指标，主客观评价一致性达80%。.2) 建立了磁流变阀控半主动悬架的正向综合优化方法。提出常见阀系阻尼特性的三参数统一模型，优化半主动悬架执行器性能边界，建立机-电-液-磁耦合系统磁场特性优化方法，发明并研发了高性能磁流变阀控减振器样机，其可控比达3.95/2.20(拉伸/压缩)、结构紧凑、仅需3W的驱动功率和6.1mL磁流变液。.3) 建立了簧载质量在线识别方法、路面输入主频及路面不平度等级识别方法、侧倾中心在线估计方法，实现了整车状态与路面输入的统一观测。.4) 建立了磁流变阀控半主动悬架汽车瞬态动力学特性的协调控制策略。提出了汽车载荷转移比等值线，量化描述了汽车侧翻风险，明确汽车动力学稳定边界；通过滚动优化实现半主动悬架的动态赋能；通过滑模变结构控制实现阻尼力的快速跟随，形成一套磁流变阀控半主动悬架与整车的集成及评价方法。.在车辆动力学与控制的著名期刊/会议发表论文13篇，另在会议上做邀请/口头报告10次；授权发明专利9项；获省部级一等奖2项，省部级人才奖1项，国际人才奖1项；毕业研究生9人，在读研究生3人，新晋教授1人、副教授1人，培育中国科协青托人才2人。