深海采矿车行走的专家模糊控制

深海采矿车的作业过程,受作业环境和采矿车自身的影响,具有随机性、非线性和时变等特性,针对该复杂过程,提出了专家模糊控制算法．该算法参考履带车辆的运动学方程,结合履带车辆人工操作经验整合的专家规则,构成专家系统,实现采矿车绝对速度和航向角的闭环控制;采用模糊控制算法,对采矿车的左、右履带速度进行控制．仿真结果验证了该方案的可行性和有效性．

     

深海采矿车的自修正专家模糊控制

深海自行走履带采矿车作业过程,受到作业环境和采矿车自身的影响,具有未知性、随机性、非线性等特性。针对这种复杂控制过程,采用一种基于自修正专家模糊控制的路径跟踪控制方案,控制深海履带车行走。该方案参考履带车辆转向运动学方程,采用具自调整功能的模糊算法,对深海底履带集矿机的左右履带速度进行控制。仿真结果验证了该方案的可行性和有效性。     

一种新的履带机器车轨迹跟踪控制

以履带机器车为研究对象,通过对履带机器车轨迹跟踪误差的分析,给出了履带车的内部误差和外部误差的定义。采用交叉耦合控制器对履带车辆的内部误差进行补偿,采用专家模糊控制器对履带机器车的外部控制误差进行补偿,从而实现了履带机器车的轨迹跟踪控制。仿真结果验证了该算法的有效性。     

海底采矿车转向半径分析及速度同步控制

海底采矿车为液压驱动低速履带车辆,其转向性能对于海底采矿的路径规划及避障都很重要.文中对海底采矿车实际转向半径进行了分析,提出了实现给定转向半径的控制方法,为海底采矿车转向运动控制提供理论依据.此外,海底环境非常复杂,海底采矿车由于海底沉积物极稀软容易出现打滑,对履带式采矿车的两侧履带同步行走控制提出了比较高的要求.通过对液压驱动马达进行速度反馈控制,在考虑打滑情况下实现履带同步控制 .最后,设计出基于模糊PID的液压驱动速度同步控制系统,并对该控制系统进行了仿真,取得了较好的控制效果.     

深海底采矿机器车运动控制研究与虚拟仿真

采矿机器车是一种在水深5000-6000米的海底采集锰结核的智能机械.由于深海环境复杂,单一的控制无法达到集矿机行走的要求.针对集矿机的履带速度控制,设计了模糊PID的履带速度内环控制器.针对集矿机行走偏差,设计了模糊的外环控制器,并加入一智能积分器与模糊控制并联以消除静差和极限环振荡.利用虚拟现实技术仿真,证明了该控制系统是可靠的.     

液压混合动力履带车辆联合制动模糊控制

针对液压混合动力履带车辆联合制动系统,为了实现制动过程平稳性,提出了基于制动力分配原则的模糊控制策略.首先在MATLAB中建立了能量再生制动系统和机械制动系统以及车辆动力学仿真模型,然后设计了以制动力分配系数为控制变量的联合制动模糊控制器,给出了模糊控制规则,建立了控制系统仿真模型,并在不同制动强度条件下对车辆制动过程进行仿真.仿真结果表明,联合制动模糊控制系统能够有效回收制动能量,同时与PID控制相比明显改善和提高了履带车辆制动过程稳定性.     

高速履带车辆转向机理仿真

该文运用系统分析的方法,研究坚实地面条件下高速履带车辆转向过程的理论及其计算机仿真.以履带滑动转向理论为基础,考虑影响履带车辆转向的诸多因素(质心位置、负荷分布等),建立了履带车辆转向过程动力学模型.并且为求解模型中的微分-代数混合方程,编写相应程序进行了仿真计算,对高低速两种情况下高速履带车辆的转向过程进行了计算机仿真实验,仿真计算的结果与实车野外实验的结果呈现一致性.该文特别在分析履带车辆高速转向过程中研究了离心力通过履带接地压力而对履带车辆转向过程的影响.     

铰接履带式海底采矿车越障性能仿真研究

针对产于复杂恶劣地形海山表面的深海矿产资源钻结壳,提出了钴结壳采矿车采用铰接式履带车的技术方案,利用机械系统动力学仿真软件ADAMS/ATV履带车工具包,开发了铰接履带式海底采矿车的三维动力学模型和虚拟样机,进行了其通过垂赶障碍和沟槽地形的越障性能仿真研究和结果分析.仿真研究表明,铰接履带式海底采矿车建模正确,仿真真实,越障性能优良,且超过我国钴结壳采矿车技术要求,仿真数据可为物理样机研制提供技术参考.     

高速履带车辆履带预紧张力对平顺性的影响

高速履带车辆的机动性、平顺性和可靠性研究是高速履带车辆机动性研究的重要内容。目前在理论分析中，通常不考虑履带预张紧力对车辆平顺性的影响，在工程实际中履带预张紧力常根据使用经验来确定，也不考虑对车辆平顺性的影响。因此，履带预张紧力对高速履带车辆的平顺性的影响不得而知。该文应用多刚体动力学软件ReeurDyn建立了某高速履带车辆的非线性实体模型、路面模型和履带模型。在同一车速、相同路面下，分别以6％、8％、10％、12％和14％的履带预张紧力进行了车辆行驶仿真计算。履带预紧力太小，履带容易脱带，履带预张紧力太大，履带和主动轮磨损剧烈，通过对计算结果比较分析，该高速履带车履带预张紧力取8％左右较为合适，而且随着履带预张紧力的增加，高速履带车辆振动加剧。     

树枝形铁路专用线取送车问题的遗传算法研究

合理确定专用线取送车的作业顺序,有利于减少货车在站停留时间,加速车辆周转。通过分析树枝形专用线取送车作业特点,构造了该问题的染色体表达,实现了该问题的遗传算法,并结合算例进行计算,结果表明此算法可以有效地求得树枝形专用线取送车问题的最优解或近似最优解。     

Autonomous driving at the handling limit using residual reinforcement learning

While driving a vehicle safely at its handling limit is essential in autonomous vehicles in Level 5 autonomy, it is a very challenging task for current conventional methods. Therefore, this study proposes a novel controller of trajectory planning and motion control for autonomous driving through manifold corners at the handling limit to improve the speed and shorten the lap time of the vehicle. The proposed controller innovatively combines the advantages of conventional model-based control algorithm, model-free reinforcement learning algorithm, and prior expert knowledge, to improve the training efficiency for autonomous driving in extreme conditions. The reward shaping of this algorithm refers to the procedure and experience of race training of professional drivers in real time. After training on track maps that exhibit different levels of difficulty, the proposed controller implemented a superior strategy compared to the original reference trajectory, and can to other tougher maps based on the basic driving knowledge learned from the simpler map, which verifies its superiority and extensibility. We believe this technology can be further applied to daily life to expand the application scenarios and maneuvering envelopes of autonomous vehicles.     

提高车辆安全性的输出反馈自适应控制

研究含有时变参数的车辆动力学模型的输出跟踪控制问题.控制目标是使车辆的横摆角速度和质心侧偏角分别跟踪理想的设定值,通过反推方法设计输出反馈自适应控制器.控制器的输出为主动横摆力矩,通过控制主动横摆力矩来控制车辆的输出响应跟踪理想的输出信号,从而提高车辆的安全性.仿真结果表明,该控制器能更好地适应车速和路况的变化,鲁棒性强.     

虚拟现实在AUV运动控制研究中的应用

基于软件平台Vega和Creator开发出AUV循迹航行的视景仿真系统。研究了虚拟现实技术和AUV循迹控制相结合的技术，文中详细描述了其硬件系统的组成、系统软件的选择、模型的建立、虚拟海洋环境的生成，以及应用软件的设计与实现。仿真结果表明，该系统能逼真的演示出AUV循迹航行的全过程，并能满足不同情况下的仿真需要。     

两轮自平衡车控制系统的设计与实现

根据飞思卡尔智能车竞赛的要求,设计了基于MC9S12XS128单片机的两轮自平衡智能车控制系统.介绍了该智能车系统的硬件模块电路设计、控制系统的构成及核心控制算法的实现.在此基础上详细介绍了用于智能车直立控制、速度控制和方向控制的参数调试时简单易行的关键技术.经过反复多次的实验表明,本文设计的两轮自平衡车控制系统性能可靠,在车身保持直立平衡的同时能够沿着赛道快速平稳运行.     

Influence of track conditions and wheel wear state on the loads imposed on the infrastructure by railway vehicles

Nowadays, one of the most sensible issues in the railway industry is the damage on vehicles caused by the track conditions and the infrastructure deterioration due to the trains’ passage. Therefore, it is essential to acquire a better understanding on how the operation conditions influence the wear evolution of the railway wheels and the consequences of their changing profiles on vehicle–track interaction forces. In this work, a computational tool is used to simulate the dynamic performance of integrated railway systems and to predict the wear evolution of wheel profiles. The tool is applied to realistic operational scenarios with the purpose to evaluate the influence of the track conditions, defined by the track geometry and by its irregularities, on the wear progression of railway wheels. The loads imposed to the railway infrastructure by a trainset running at different velocities, on a track with and without irregularities, and equipped with wheelsets having new and worn profiles is also studied. The studies performed here show that the levels of track irregularities considered have a negligible influence on the wear progression. Furthermore, the loads imposed to the track during trainset operation are not affected by the wear state of the wheels. On the other hand, the track imperfections can affect significantly the vehicle–track interaction forces.     

A predictor-corrector guidance control scheme for AGV navigation

This paper presents a scheme that employs feedforward control in conjunction with a predictor-corrector scheme for guidance control of Automated Guided Vehicles (AGVs). The predictor-corrector scheme provides the desired values of steering parameters which depend on the geometry of the track and a driving criterion. The geometry of the track/road ahead of the vehicle is obtained by extrapolating the identified (estimated) geometry of the track/road traversed during the elapsed time interval. This real-time identification is carried out by fitting a curve to the path traversed by the vehicle. The coordinates of the path are provided by a transformation formulation which makes use of the motion parameters and a kinematic model of the vehicle. The driving criterion specifies the positioning of the AGV on the track. Several possible criteria are identified in the paper and mathematical formulations are presented for one such criterion. Results of off-line calculations using simulated track profiles and experimental data obtained using a prototype AGV while following various track profiles are provided for illustration.     

基于车辆响应计算的地铁轨道平顺状态评价

针对目前轨道检测数据以幅值超限统计的方式评价轨道平顺状态而未考虑轮轨关系及车辆实际响应的问题, 提出一种基于车辆响应计算的地铁轨道平顺状态评价方法。该方法引入随机振动虚拟激励法对车辆动力学模型的响应谱进行计算, 再由响应谱计算得到平稳性指标, 指出在车辆动力学参数稳定状态下, 平稳性指标可用于对轨道平顺状态的判定。不同车速下高级别轨道谱的平稳性指标均优于低级别轨道谱, 结果表明该方法可对轨道的整体状态进行量化评价。该算法可用于深入分析轨检数据, 并为轨道状态评价提供新的思路。     

An approach for modeling long flexible bodies with application to railroad dynamics

Considering track flexibility in railroad vehicle simulations can lead to improved results. In modeling a railroad vehicle as a multibody system, track flexibility can be incorporated by using the floating frame of reference formulation (FFRF), which describes rail deformations in terms of shape functions defined in the track body frame of reference. However, the FFRF method is subject to two serious shortcomings, namely: it uses unreal track boundary conditions to calculate shape functions and requires a large number of functions to describe deformation. These shortcomings can be circumvented by defining shape functions in the trajectory frame of reference. Based on this notion, a new form of FFRF that can be used to describe the dynamics of long bodies subjected to moving loads (cable cars, zip-lines, elevator guides, pantograph catenary mechanism, etc.) was developed here. The shape functions selected in this work are based on the steady deformation exhibited by a beam on a Winkler foundation under the action of a moving load. However, other sets of shape functions more appropriate for transient dynamics are suggested. The definition of the deformation shape functions in a frame that moves with respect to the flexible body produces new terms in the generalized inertia forces of the flexible track. The proposed approach was applied to an unsuspended wheelset traveling on a tangent track supported on an elastic foundation. The results thus obtained under variable foundation stiffness conditions are discussed and comparisons made with the case of a rigid track. The new approach is also compared with the moving mass problem as solved with the mode superposition method.