Self-learning drift control of automated vehicles beyond handling limit after rear-end collision

Vehicles involved in traffic accidents generally experience divergent vehicle motion,which causes severe damage.This paper presents a self-learning drift-control method for the purpose of stabilizing a vehicle’s yaw motions after a high-speed rear-end collision.The struck vehicle generally experiences substantial drifting and/or spinning after the collision,which is beyond the handling limit and difficult to control.Drift control of the struck vehicle along the original lane was investigated.The rear-end collision was treated as a set of impact forces,and the three-dimensional non-linear dynamic responses of the vehicle were considered in the drift control.A multi-layer perception neural network was trained as a deterministic control policy using the actor-critic reinforcement learning framework.The control policy was iteratively updated,initiating from a random parameterized policy.The results show that the self-learning controller gained the ability to eliminate unstable vehicle motion after data-driven training of about 60,000 iterations.The controlled struck vehicle was also able to drift back to its original lane in a variety of rear-end collision scenarios,which could significantly reduce the risk of a second collision in traffic.

Causes and typical control model of wind-drift sandy lands in abandoned channel of the Yellow River

The historical formation and development of the abandoned channel of the Yellow River is reviewed and its causes of formation and present condition of prevention and control are analyzed in this paper. Based on this analysis, some ideas about control, critical problems and countermeasures in the next period are proposed with two typical control models as examples. We suggest that in preventing and controlling the wind-drift sandy lands in the region, the emphasis should be to develop, with a greatly expanded effort, a recycling economy. This should realize a combination of two ideas, i.e. integrate combating desertification with a structural adjustment of agricultural and an increase in the income of farmers.

Numerical Simulation of Turret Moored Ship Performance in Variable Ice Drift Based on Heading Control

The frequent change in ice drift direction poses a significant challenge for turret moored ship in ice. Variability in ice drift is mainly caused by the winds and currents. To solve this problem, a new method with numerical simulation based on heading control is applied to reduce the risk of operation of The Arctic Tandem Offloading Terminal(ATOT),which includes an offloading icebreaker(OIB) moored to a submerged turret and a shuttle tanker moored at the stern of the OIB in this paper. An icebreaking tanker, MT Uikku, was modeled in a simulation program. Then the level ice load on the tanker was calculated with different ice thicknesses and drift speeds, after which a heading controller assisted with mooring system is used to simulate the horizontal motion of the tanker under the ice action.

Shift control method for the local time at descendi ngnode based on sun-synchronous orbit satellite

This article analyzes the shift factors of the descending node local time for sun-synchronous satellites and proposes a shift control method to keep the local time shift within an allowance range. It is found that the satellite orbit design and the orbit injection deviation are the causes for the initial shift velocity, whereas the atmospheric drag and the sun gravitational perturbation produce the shift acceleration. To deal with these shift factors, a shift control method is put forward, through such methods as orbit variation design, orbit altitude, and inclination keeping control. The simulation experiment and practical application have proved the effectiveness of this control method.

Robust Adaptive Control of Nonholonomic Systems with Nonlinear Parameterization

全球适应的州的反馈控制策略与强壮的非线性的飘移和未知非线性的参数在锁住的形式为 nonholonomic 系统的一个类被介绍。一种参数分离技术被介绍把非线性的 parameterization nonholonomic 系统转变成一个象线性一样 parameterized nonholonomic 系统。然后，反馈支配设计被使用设计一个全球适应稳定控制器，切换的策略被开发消除 uncontrollability 的现象。建议控制器能保证那得到状态全球性集成到起源的所有系统，当另外的信号仍然保持围住时。模拟例子表明有效性和建议控制器的柔韧的特征。

Magnetic Sensorless Control of Plasma Position and Shape in a Tokamak

Magnetic sensorless sensing and control experiments with the plasma horizontal position have been carried out in the superconducting tokamak HT-7. The sensing is made to focus on the ripple frequency component of the power supply with thyristor and directly from them without time integration. There is no drift problem with the integrator of wagnetic sensors. Two kinds of control experiments have been carried out： to keep the position constant and swing the position in a triangular waveform, And magnetic sensorless sensing of plasma shape is discussed.

Simulation and Control of Turbulence at Tokamaks with Artificial Intelligence Methods

The control of turbulence at tokamaks is very complex problem.The idea is to apply the fuzzy Markovian processes and fuzzy Brownian motions as good approximation of general robust drift kinetic equation. It is obtained by using the artificial neural networks for solving of appropriate advanced control problem. The proof of the appropriate theorem is shown.

Optimal weakening and damping using polynomial control for seismically excited nonlinear structures

This paper presents an approach for the optimal design of a new retrofit technique called weakening and damping that is valid for civil engineering inelastic structures. An alternative design methodology is developed with respect to the existing ones that is able to determine the locations and the magnitude of weakening and/or softening of structural elements and adding damping while insuring structural stability. An optimal polynomial controller that is a summation of polynomials in nonlinear states is used in Phase I of the method to reduce the peak response quantities of seismically excited nonlinear or hysteretic systems. The main advantage of the optimal polynomial controller is that it is able to automatically stabilize the structural system. The optimal design of a shear-type structure is used as an example to illustrate the feasibility of the proposed approach, which leads to a reduction of both peak inter-story drifts and peak total accelerations.

植保无人机精准喷施方法研究综述

作为一种新兴农业技术,植保无人机以其高效、精准、灵活等特点在农作物疾病和虫害防治中具有重要意义。综述了植保无人机精准喷施方法的关键技术,包括植保无人机发展现状、路径规划算法、喷施器研究和漂移控制。通过对相关文献的分析和整理,总结了植保无人机路径规划算法的特点和应用情况,重点介绍了经典路归算法、遗传算法以及蚁群优化等元启发算法的优点和不足,以及喷施器研究和漂移控制研究的进展和挑战。最后,提出了未来研究的方向和建议,包括改进算法性能、优化路径规划策略、提高喷施器的精度和稳定性、优化漂移控制算法等。旨在为相关研究者提供全面的研究概览,推动植保无人机精准喷施技术的进一步发展和应用。

桶混助剂和剂型创新在农药雾滴飘移控制中的应用及研究进展

近年来,随着植保无人机施药技术的迅速发展,农药雾滴飘移引起的药害问题更加凸显。除了降低农药利用率,雾滴飘移还对周围环境造成污染,同时也危害人类健康。雾滴特性、药械参数和施药环境是影响农药雾滴飘移的重要因素,其中雾滴特性直接受到桶混助剂和农药剂型的影响。基于农药助剂和制剂研发应用过程中的理论积累和实践经验,笔者通过分析影响农药雾滴飘移的原因,综述了农药桶混助剂在农药防飘移技术中的研究进展,分析了农药剂型创新在防飘移技术中的潜在用途,并对该领域的发展前景进行展望,以期为通过筛选优良助剂和创新农药剂型来减少农药飘移、提高农药有效利用率提供参考和指导。

极限工况下的动态漂移控制策略

综合考虑车辆在直线路段或小曲率弯道的常规驾驶策略以及车辆在大曲率弯道的极限漂移控制策略,通过控制方式切换策略将二者联系在一起,提出一种面向动态漂移场景的动态漂移控制策略,主要包括基于横向LQR以及纵向前馈反馈控制的常规驾驶策略、基于MPC的漂移控制策略以及基于期望横摆角速度的控制方式切换策略。仿真结果显示,所提出的动态漂移控制策略成功实现车辆在直线道或小曲率弯道处的常规驾驶控制模式与车辆在大曲率弯道处的漂移控制模式之间相互切换,使车辆不必在弯道处受限于自身的转弯半径而不得不通过降低自身速度来应对更小的转弯半径。通过对比是否采用漂移策略显示,采用漂移控制策略更快地完成掉头动作且拥有更小的横向偏差。在应对小半径弯道时,车辆采用漂移控制策略远比常规驾驶获得更高的机动性与更灵活的姿态。

纯电动后驱汽车横纵向漂移动力学研究

对车辆轮胎漂移极限工况的分析可以大幅提高自动驾驶车辆的横纵向控制能力以及驾驶安全性。基于UniTire的大滑移的附着表达能力优化了整车漂移的控制算法,并依据整车稳定控制原理和预期制动回正时间参数等,实现漂移结束后车辆快速恢复稳态直线行驶的轮缸目标压力的计算,通过DYNA4与Simulink在CANoe工控机平台进行了快速原型验证。结果表明,优化后的控制算法能使车辆快速进入漂移的横纵向平衡状态以及漂移结束后快速恢复直线行驶,且能达到控制的实时性要求。

基于PI闭环反馈的EtherCAT分布式时钟漂移补偿优化

接入工业总线的设备的增加会导致高延迟等同步性问题。基于EtherCAT对分布式时钟同步算法进行研究与分析,针对其在漂移补偿过程中存在补偿精度低的问题,提出了一种基于闭环反馈控制思想的动态漂移补偿算法。算法先利用定点数改进本地时钟,再利用PI控制调节漂移补偿值。最后搭建了测试平台,包括基于SOEM实现的主站与基于STM32+FPGA架构实现的从站,优化前后的算法分别在FPGA中实现。测试结果表明:定点数改进的本地时钟分辨率可以达到2^(-20) ns, PI闭环反馈优化后的漂移补偿算法可以将同步误差降低到25 ns之内,明显提高从站之间的同步性能。

复合地层盾构姿态上漂分析及盾构刀盘刀具选型

土压平衡盾构在复合地层中掘进时面临复杂的工程问题,易发生“结泥饼”、盾构姿态上漂等施工难题。依托南昌地铁4号线民园路西站-火炬站工程,针对复合地层盾构施工中的姿态上漂问题进行研究,并结合盾构刀盘刀具的特点进行分析,明确了姿态上漂的原因和影响因素。在盾构刀盘刀具选型方面,综合考虑了刀盘类型、刀具形状、刀具材料等因素,并采用多目标优化方法进行了刀盘刀具选型。通过对不同刀盘刀具组合的性能进行评估和比较,选出了最优的刀盘刀具组合。通过实际工程案例的验证,证明所提出的姿态上漂处置措施和刀盘刀具选型优化方法的有效性和可行性。研究结果表明,在复合地层盾构施工中,合理分析姿态上浮问题并优化刀盘刀具选型,能够有效提高施工效率,降低施工风险。

ARL8820直读光谱仪分析钢中氮元素异常因素及改进措施

本文针对ARL8820直读光谱仪在日常分析中出现氮元素检测值忽高忽低或无检测值异常情况,通过对使用氢气纯度,仪器连接气管漏点,激发平台变形,火花室石杯破损,激发平台、石英杯密封圈磨损程度等排查处理,清理仪器透镜、IMC板及元素板网线插口,规范样品制备,正确选择样品对标漂移校正,控样比对验证等,有效保障了光谱仪在线快速分析钢中氮元素的稳定性与准确性,为钢轧工序生产及时提供数据支撑。

磁场对脱手检测功能的影响与优化方法分析

阐述一种通过监控学习获取可信EPS零漂的方法,并将可信EPS零漂引入到脱手检测控制逻辑中。该方法有效地消除扭矩传感器零漂对脱手报警的影响,提高自动驾驶辅助系统脱手报警的准确率。

海安市蚕桑生产防中毒保安全的几点做法

近年来,随着工业化进程加快,环境中不明化学因子增多,养蚕风险加剧。另一方面,农业种植大户普遍应用无人机飞防治虫,药剂漂移引致蚕桑生产中毒现象频频发生,蚕桑生产安全问题突出。海安市政府办公室通过广泛培训宣传,开展技术指导,加强督查和执法处罚,加大考核奖惩等措施,有效控制农业治虫对蚕桑生产影响。在桑园治虫方面,按要求选用农药,按标准配制药液,防止农药残留影响养蚕安全。

敦煌莫高窟风沙危害综合防护体系设计研究

风沙危害是敦煌莫高窟保护面临的主要环境问题之一，建立一个完整的防护体系是解决这一问题的有效途径。在对20世纪80年代以来建立的防沙治沙试验工程防护效应分析研究的基础上，对敦煌莫高窟风沙危害综合防护体系设计进行了讨论。根据因地制宜，因害设防；以固为主，固、阻、输、导相结合；以工程和生物措施为主，兼顾化学固沙；高新技术与常规治理技术相结合；重点治理，分阶段实施与长远目标相结合的设计原则，认为根据不同地貌特征及地表组成物质，依次建立鸣沙山前缘流动沙丘和平坦沙地阻固区、窟顶戈壁防护区、洞体崖面固结区、石窟对面流动沙丘固定区、窟区防护林带建设区及天然植被封育保护区，可使危害莫高窟的风沙灾害得到有效控制，并达到莫高窟作为世界文化遗产和全国重点文物保护单位对环境质量的要求。

农药雾滴飘移控制技术研究进展

农药雾滴飘移是造成环境污染、农药流失、农药有效利用率低的一个重要原因,分析影响雾滴飘移的主要因素,研究农药雾滴飘移机理,不仅可以为控制雾滴飘移的喷雾部件的研究提供理论依据,同时对提高农药的施药效果,减少农药飘失,增强环境保护都具有重要的现实意义。该文分析了当前国外控制农药雾滴飘移的先进技术及喷雾部件的研究现状。通过分析中国农药使用现状及存在问题,提出在中国要有效控制雾滴飘移,除了采取合适的施药方法,还应进一步加强农药雾滴飘移控制技术及喷雾部件的研究。

太阳同步卫星降交点地方时漂移控制策略的研究

为将太阳同步卫星降交点地方时控制在允许的范围内,对其漂移因素进行分析,确定了卫星轨道设计和入轨偏差所导致的降交点地方时初始漂移速度,而大气阻力和太阳引力摄动则使得降交点地方时产生漂移加速度.针对产生漂移的原因,提出通过轨道偏置设计、轨道高度和轨道倾角保持控制等方法,将漂移限制在允许的范围内.仿真实验结果表明了所进行的分析和所提出的控制策略的正确性.