Research on Vehicle Control Technology Using Four-Wheel Independent Steering System

The enhancement of vehicle handling stability and maneuverability through active and independent rear wheels control is presented. Firstly, the configuration of four-wheel independent steering prototype vehide is introduced briefly. Then the concrete overall design of the electronic controllers of four wheel independent steering system （4WIS） is formulated in details. Under the control strategy of zero sideslip angle at mass center, the mathematical model of 4WIS is established to deduce the equations of separated rear wheel steering angles. According to these equations, simulation analysis for 4WIS vehicle performances is finished to show that 4WIS vehicle can improve the maneuverability greatly at low speed and increase the handling stability at high speed. Finally, the road test of 4WIS vehide has performed to verify the correctness of simulation and show that compared with the conventional four wheel steering （4WS） vehicle, the 4WIS vehicle not only improves the kinematical harmony but also decreases steering resistance and lighten abrasion of tires.

Virtual Simulation System with Path-following Control for Lunar Rovers Moving on Rough Terrain

Virtual simulation technology is of great importance for the teleoperation of lunar rovers during the exploration phase, as well as the design of locomotion systems, performance evaluation, and control strategy verification during the R&D phase. The currently used simulation methods for lunar rovers have several disadvantages such as poor fidelity for wheel-soil interaction mechanics, difficulty in simulating rough terrains, and high complexity making it difficult to realize mobility control in simulation systems. This paper presents an approach for the construction of a virtual simulation system that integrates the features of 3D modeling, wheel-soil interaction mechanics, dynamics analysis, mobility control, and visualization for lunar rovers. Wheel-soil interaction experiments are carried out to test the forces and moments acted on a lunar rover’s wheel by the soil with a vertical load of 80 N and slip ratios of 0, 0.03, 0.05, 0.1, 0.2, 0.3, 0.4, and 0.6. The experimental results are referenced in order to set the parameters’ values for the PAC2002 tire model of the ADAMS/Tire module. In addition, the rough lunar terrain is simulated with 3DS Max software after analyzing its characteristics, and a data-transfer program is developed with Matlab to simulate the 3D reappearance of a lunar environment in ADAMS. The 3D model of a lunar rover is developed by using Pro/E software and is then imported into ADAMS. Finally, a virtual simulation system for lunar rovers is developed. A path-following control strategy based on slip compensation for a six-wheeled lunar rover prototype is researched. The controller is implemented by using Matlab/Simulink to carry out joint simulations with ADAMS. The designed virtual lunar rover could follow the planned path on a rough terrain. This paper can also provide a reference scheme for virtual simulation and performance analysis of rovers moving on rough lunar terrains.

Design and Dynamics Analysis of Anti-skid Braking System for Aircraft with Four-wheel Bogie Landing Gears

In asymmetric conditions,the movement and loads of left/right wheels or front/back wheels of the aircraft with multi-wheel or four-wheel bogie landing gears are inconsistent.There are few open literatures related to anti-skid braking system for multi-wheels due to technology blockade.In China,the research on multi-channel control and non-equilibrium regulation has just started,and the design of multi-channel control system for anti-skid braking,the simulation of asymmetry taxiing under braking are not studied.In this paper,a dynamics model of ground movement for aircraft with four-wheel bogie landing gears is established for braking simulation, considering the six-degree-of-freedom aircraft body and the movement of bogies and wheels.A multi-channel anti-skid braking system is designed for the wheels of the main landing gears with four-wheel bogies.The eight wheels on left and right landing gears are divided into four groups,and each group is controlled via one channel.The cross protection and self-locked protection modules are added between different channels.A multi-channel anti-skid braking system with slip-ratio control or with slip-velocity control is established separately.Based on the aircraft dynamics model,aircraft braking to stop with anti-skid control on dry runway and on wet runway are simulated.The simulation results demonstrate that in asymmetric conditions,added with cross protection and self-locked protection modules,the slip-ratio-controlled braking system can automatically regulate brake torque to avoid deep slipping and correct aircraft course.The proposed research has reference value for improving brake control effect on wet runway.

智能座舱方向盘收纳隐藏系统功能设计

随着汽车智能技术的发展,人们对驾乘体验的智能化需求日益增多,智能座舱和智能底盘是实现这一需求的关键总成。方向盘迎宾功能是智能座舱体现舒适性和体验性的核心功能,同时,未来高等级智能驾驶汽车实现完全自主驾驶后方向盘还应具有收纳隐藏功能,以进一步拓展良好的驾乘舒适性和体验性。文章研究一种既有传统方向盘迎宾功能,又有收纳隐藏功能的智能座舱方向盘收纳隐藏系统,通过对方向盘收纳隐藏系统的构成、工作原理、控制逻辑等方面的研究,进行方向盘收纳隐藏系统的功能设计,包括电动调节功能、迎宾功能、方向盘翻转功能、电调管柱长距离收纳功能、可拓展功能等,满足了未来智能线控转向系统中的路感模拟装置需具备收纳隐藏的新技术要求。

面向线控制动车辆单轮制动失效的稳定性控制

基于线控制动系统四轮可独立控制的特点,提出一种协同线控转向与线控制动的制动力实时分配的控制方法。该方法根据三轮富余制动力能否补偿失效轮损失制动力,按制动强度分为轻度、中度和重度制动3种工况,针对重度制动工况下制动力补偿不足问题,基于积分滑模控制方法设计前轮主动转向器,综合考虑单轮制动失效时各轮垂直载荷的变化和前轮转角介入后轮胎力的耦合,采用序列二次规划算法(sequental quadratic programming,SQP),实时分配剩余三轮制动力。仿真结果表明:在不同制动强度及不同轮制动失效下所提控制方法相较于无控制,横向跑偏分别减少了89.98%、91.90%、96.96%、89.62%,制动强度至少达到正常制动时的97.5%。因此,该控制方法在保证横向稳定性的同时最大限度地满足驾驶员的制动期望,有效抑制因单轮制动失效导致的车辆跑偏甩尾等问题。

果树剪枝机器人四驱式底盘控制系统设计与实现

能够自主完成果树修剪任务的机器人是目前林果业智能装备的一个主要研究方向。四驱底盘是机器人的基础,其控制系统设计对机器人的性能和稳定性有至关重要的作用。对果树剪枝机器人四驱式底盘控制系统进行设计,包括控制系统硬件选型和搭建、运动路径设计、避障算法、程序设计,并进行了验证。实验结果表明,剪枝机器人底盘控制系统的半自动控制可以实现模糊避障功能,为后续果树剪枝机器人的研究提供参考。

计及电动汽车与飞轮储能单元的孤岛微电网负荷频率控制

针对孤岛微电网惯性和阻尼不足的问题,引入飞轮储能单元,并构建带飞轮储能单元的孤岛微电网负荷频率控制模型,研究了通信时滞对孤岛微电网系统的影响。采用适用的Lyaunov-Krasovskii泛函(LKF),通过广义自由权积分不等式对导数积分项进行界定,从而得到了时滞相关稳定性判据。当考虑电动汽车电池状态对系统增益的影响时,将系统视为参数不确定时滞系统。通过不同的参数设定,进行了仿真实验,结果证明了所提方法的有效性与优越性。

铝合金车轮涂装前处理线自动控制系统对涂层性能的影响

为提升铝合金车轮涂装线自动化程度,在涂装前处理引入自动监控系统。确定游离碱、游离酸及锆点的检测方法,依据检测结果自动调整加药量。对比人工与设备检测结果,监控设备运行稳定性。

基于麦克纳姆轮技术的自动化引导车(AGV)设计

【目的】设计一款能在复杂狭小空间内灵活运动,且具有一定承载、搬运货物能力的AGV小车。【方法】首先,将麦克纳姆轮与AGV小车结合,利用麦克纳姆轮独特的全向移动特性,使小车实现任意方向、角度的转动,从而轻松应对各种复杂的运输环境。其次,通过剪叉式机构与丝杠螺母副相结合,同时加上辅助支撑的保险结构,使AGV小车具有一定承载、搬运货物的能力。最后,对AGV小车的电控系统进行分析设计,通过精确控制电机、传感器和导航系统等关键部件,保证对AGV小车实现精准的控制。【结果】麦克纳姆轮与AGV小车的结合能够使小车在各种复杂环境下实现高效、准确的自动化搬运,剪叉式机构与丝杠螺母副相结合的结构设计能使小车具有运输货物的能力,电控系统则保证AGV小车的稳定性。【结论】基于麦克纳姆轮的AGV小车能够应对复杂的工况,灵活地运输货物,极大程度上节约劳动力,节约成本,实现智能化。

轮式电力巡检机器人控制系统设计与实现

在电网建设过程中,关于电力巡检机器人的开发仍面临一些挑战,例如没有一个普适的系统平台。文章设计了一种利用数字处理器和PC104的智能电力巡检机器人,其具有嵌入式控制芯片,可以执行多种电力巡检任务,利用内置的多种传感器、高分辨率的视频收集器、GPS定位器以及无线远程通信工具等,可以对电力管道和电气设备进行巡检,并利用大型数据库与控制台实现信息的互动。在试验室中模拟电力巡检工作场景,对机器人控制系统进行联调测试,发现该系统基本达到了预设目的。文章围绕轮式电力巡检机器人控制系统的设计、实现进行分析。

Determination of the dynamic characteristics of locomotive drive systems under re-adhesion conditions using wheel slip controller

To investigate the re-adhesion and dynamic characteristics of the locomotive drive system with wheel slip controller,a co-simulation model of the train system was established by SIMPACK and MATLAB/SIMULINK.The uniform running and starting conditions were considered,and the influence of structural stiffness of the drive system and the wheel slip controller on the re-adhesion and acceleration performance of the locomotive was investigated.The simulation results demonstrated that the stick-slip vibration is more likely to occur in locomotives with smaller structural stiffnesses during adhesion reduction and recovery processes.There are many frequency components in the vibration acceleration spectrum of the drive system,because the longitudinal and rotational vibrations of the wheelset are coupled by the wheel‒rail tangential force when stick-slip vibration occurs.In general,increasing the structural stiffness of the drive system and reducing the input energy in time are effective measures to suppress stick-slip vibration.It should also be noted that inappropriate matching of the wheel slip controller and drive system parameters may lead to electro-mechanical coupling vibration of the drive system,resulting in traction force fluctuation and poor acceleration performance.

基于滑模理论的线控转向汽车稳定性控制研究

为了提高汽车转向时的稳定性与安全性,在理想传动比前馈控制的基础上,设计了综合考虑横摆角速度和质心侧偏角的主动转向控制器。主动转向控制器根据状态参数实际值与理想值之间的误差,经过自适应滑模控制器计算出独立于驾驶员的额外附加转角,以对前轮转角进行补偿,使得汽车的实际响应跟随理想值,以改善汽车的稳定性。最后,在Matlab/Simulink软件和Carsim软件中建立了线控转向联合仿真模型,分别在双移线、正弦输入以及高、低路面附着系数工况下对设计的主动转向控制器进行试验,结果表明,主动转向控制器明显减小了横摆角速度和质心侧偏角2个参数的实际值与理想值之间的误差,提高了汽车转向时的稳定性。

4WID高地隙自走式电动喷雾机定速巡航控制方法

针对4WID高地隙自走式电动喷雾机在复杂工况下,面对来自外部道路坡度改变及内部药液喷洒带来整备质量下降,从而导致喷雾机行驶速度稳定性差、作业质量恶化等问题,在分析4WID高地隙自走式电动喷雾机结构与纵向动力学特性基础上,设计一种定速巡航分层控制算法。控制算法模型接收用户设定的期望行驶车速,经过算法计算后对纵向动力学系统模型输入加速度控制信号,实现喷雾机对期望车速的跟踪。搭建的纵向动力学系统结构主要包括5个部分:逆纵向动力学模型、加速与制动切换模型、转矩分配模型、电机模型和纵向动力学模型。通过对斜坡行驶状态下喷雾机的车身状态进行受力分析可获得其逆纵向动力学及纵向动力学模型;同时,为建立合理的四轮转矩分配策略,在喷雾机车身同时具有俯仰及侧倾的条件下进行分析,以各驱动轮的附着率作为分配依据,满足不同工况下各车轮的最佳驱动力矩,确保喷雾机动力的均衡性。模型定速巡航控制采用分层控制方法,通过建立上层PID控制及下层的模糊PID控制实现对喷雾机车速的有效跟踪,通过制定模糊控制规则,自动对下层控制器的PID参数进行整定,保证在各种复杂工况下喷雾机定速巡航系统的良好适应性。应用Matlab/Simulink建立控制模型,对控制系统进行仿真分析。试验结果表明,在典型工况下,设计的定速巡航控制系统能够有效地对喷雾机的速度进行控制。具体而言,在系统输入外部干扰及自重变化条件下,该控制系统的表现良好,超调量在2%以内,响应时间小于0.2 s,稳态误差趋于0,验证了所采用控制算法的准确性。

基于STM32双轮自平衡车的设计与实现——基于分层教学模式的单片机实验教学案例

针对单片机教学过程中学生学习能力不同的问题,利用分层教学,来提升学生学习能力、学习兴趣。通过对双轮自平衡小车控制系统的制定,选用STM32单片机设计作为主板芯片,提出了系统方案设计,同时也对双轮自平衡小车控制系统的规定、架构和设计理念进行论述。设计采用串级PID,将直立环,速度环,转向环串联起来,其中直立环采用PD算法的位置式PID,速度环采用PI算法的增量式PID,转向环直接采用P算法。三个环的串联可以显示小车无论在前进,后退还是转弯时都可保持直立。针对本系统采取了参数的调试和性能的检测,从而证实了双轮平衡车控制系统的必要性和可靠性。

四驱电动赛车TCS滑模预测控制系统设计与实现

针对四驱电动方程式赛车在不同路面工况下过度打滑的问题,设计了一种结合卡尔曼滤波车速估计和滑模控制的牵引力控制系统,以提高整车直线加速性能、减小车轮打滑以保证稳定性和快速加速中的安全性;控制器以车轮滑转率为控制变量,通过调整各驱动轮输出扭矩,以保证滑转率控制在最优范围内;考虑获取准确车速是得到最优滑转率的前提,设计卡尔曼滤波器,实现车速估计;针对滑模控制自身存在的抖振问题,采用改进的指数趋近律,提高稳定性;利用Matlab/Simulink和CARSIM联合仿真,验证了该控制系统的有效性;最终完成实车测试与应用,在实际应用中实现控制系统满足四驱电动方程式赛车的快速平稳加速的工程要求。

全控器件大型水轮发电机组自动励磁系统设计

为保证大型水轮发电机组稳定运行,设计了基于全控器件的大型水轮发电机组自动励磁系统,通过全控器件实现发电机组自动励磁控制。以电压源型脉冲宽度调制变换器为全控器件,采用基于直接电流控制方法的电压源型脉冲宽度调制变换器控制方案并补充阻尼,避免其直流侧电压异常波动,优化了励磁系统电流质量。制定基于占空比调节的斩波器控制方案,调节励磁电压的占空比,避免发电机组励磁电流异常变化,完成大型水轮发电机组自动励磁控制。实验结果表明,该系统有较好的控制效果,可在1 s内实现大型水轮发电机组的稳定。

前轮转弯控制活门测试系统设计

提出了一种接口丰富、可重构扩展的单元化通用前轮转弯控制活门测试系统设计方案。依据前轮转弯控制活门的性能要求,引入单元化设计方法,详细描述了前轮转弯控制活门测试系统及电控系统的设计过程。该测试系统容错能力强,通用性好,操作简单,具有良好的可扩展性,实现了对前轮转弯控制活门的快速和自动化测试,对提高液压附件地面检测设备的可靠性和可维修性有重要的意义。

汽车线控转向系统电机冗余控制研究

针对电动汽车线控转向系统转向执行电机使用过程中位置传感器失效的问题,提出一种永磁同步电机无位置传感器冗余控制方法。文章选用内置式永磁同步电机作为线控转向系统的转向执行电机,首先对永磁同步电机的数学模型进行建模分析,其次利用电机转子的凸极特性,采用高频电压信号注入法获取电机转子的位置信息并进行解耦,从而实现电机的无位置传感器控制,最后在Matlab/Simulink软件中对搭建的电机控制模型进行仿真实验,证明控制策略的可行性。

纯电动力非公路矿用自卸车驱动系统研究及应用

传统的机械传动矿车碳排放较高,驱动系统结构复杂,在高海拔低温环境中降功率现象严重,运营成本较高。针对某100 t机械传动自卸车的驱动系统,研究了其驱动系统的组成及特点;提出了一种包括主牵引传动+辅助系统的驱动系统和控制系统方案并对控制算法进行了描述。主牵引系统采用793 kWh动力电池作为动力源,结合直接转矩控制算法驱动1台680 kW的主牵引电机,辅助系统的两个逆变模块、DC/DC模块和电池散热机组可以分别驱动转向和举升液压泵电机,为整车空调和散热风机提供电源以及为动力电池提供散热电源;对整车进行海拔5500 m、-30℃的满载工况下的制动/牵引转换、重载上坡起步、重载上坡行驶、重载下坡电制动等矿山现场装载试验,运行情况稳定可靠,降低运营成本93%,累计运行4230 h,累计运行里程4238 km。该驱动系统结构简单,回收的制动能量提高了系统能效,减少了碳排放,促进了绿色矿山的发展。

Adaptive Tracking Control of an Uncertain Nonholonomic Robot

In this paper, a new controller is proposed by using backstepping method for the trajectory tracking problem of nonholonomic dynamic mobile robots with nonholonomic constraints under the condition that there is a distance between the mass center and the geometrical center and the distance is unknown. And an adaptive feedback controller is also proposed for the case that some kinematic parameters and dynamic parameters are uncertain. The asymptotical stability of the control system is proved with Lyapunov stability theory. The simulation results show the effectiveness of the proposed controller. The comparison with the previous methods is made to show the effectiveness of the method in this article.