Optimal tracking control for automatic transmission shift process

In order to improve the shift quality, a linear quadratic optimal tracking control algorithm for automatic transmission shift process is proposed. The dynamic equations of the shift process are derived using a Lagrange method. And a powertrain model is built in the Matlab/Simulink and veri- fied by the measurements. Considering the shift jerk and friction loss during the shift process, the tracking trajectories of the turbine speed and output shaft speed are defined. Furthermore, the linear quadratic optimal tracking control performance index is proposed. Based on the Pontryagin＇ s mini- mum principle, the optimal control law of the shift process is presented. Finally, the simulation study of the 1 - 2 upshift process under different load conditions is carried out with the powertrain model. The simulation results demonstrate that the shift jerk and friction loss can be significantly re- duced by applying the proposed optimal tracking control method.

Fuzzy control on automatic frequency tracking of ultrasonic vibration system with high power and high quality factor Q

In order to realize automatic tracking drift of resonance frequency of ultrasonic vibration system with high power and high quality factor Q,adaptive fuzzy control was studied with a self-fabricated ultrasonic plastic welding machine.At first,relations between amplitude of vibration and frequency as well as main loop current and amplitude of vibration were analyzed.From this analysis,we deduced that frequency tracking process of the vibration system can be concluded as an optimizing problem of one dimensional fluctuant extremum of main loop current in vibration system.Then a method of self-optimizing fuzzy control,used for the realization of automatic frequency tracking in vibration system,is presented on the basis of self-optimizing adaptive control approach and fuzzy control approach.The result of experiments shows that the fuzzy self-optimizing method can solve the problem of tracking frequency drift very well.Response time of tracking in the system is less than 50 ms,which basically meets the requirements of frequency tracking in ultrasonic plastic welding machine.

Research on Fuzzy Control for Automatic Transmission of Tracked Vehicles

A principle of fuzzy control for tracked vehicles is proposed to make its automatic transmission system be able to adapt complex running conditions, and a model of its power train is established to be used in simulation. Based on the fuzzy control method, a fuzzy shift control system composed of a basic shift strategy and a fuzzy modification module is developed to improve the dynamic characteristics and cross-country maneuverability. Simulation results show that the fuzzy shift strategy can improve the shift quality under manifold driving conditions and avoid cycled shift effectively.Therefore, the proposed fuzzy shift strategies are proved to be feasible and practicable.

Robotic Knee Tracking Control to Mimic the Intact Human Knee Profile Based on Actor-Critic Reinforcement Learning

We address a state-of-the-art reinforcement learning(RL)control approach to automatically configure robotic pros-thesis impedance parameters to enable end-to-end,continuous locomotion intended for transfemoral amputee subjects.Specifically,our actor-critic based RL provides tracking control of a robotic knee prosthesis to mimic the intact knee profile.This is a significant advance from our previous RL based automatic tuning of prosthesis control parameters which have centered on regulation control with a designer prescribed robotic knee profile as the target.In addition to presenting the tracking control algorithm based on direct heuristic dynamic programming(dHDP),we provide a control performance guarantee including the case of constrained inputs.We show that our proposed tracking control possesses several important properties,such as weight convergence of the learning networks,Bellman(sub)optimality of the cost-to-go value function and control input,and practical stability of the human-robot system.We further provide a systematic simulation of the proposed tracking control using a realistic human-robot system simulator,the OpenSim,to emulate how the dHDP enables level ground walking,walking on different terrains and at different paces.These results show that our proposed dHDP based tracking control is not only theoretically suitable,but also practically useful.

Research and Development of Engine-Generator Set Control System for Tracked Vehicle Electric Transmission System

As an energy generating equipment, the engine-generator set supplies power to the electric transmission. Therefore, its control is one of the key technologies of electric vehicles. Based on the discussion about the demands to the engine-generator set in tracked vehicles, the detailed function of engine-generator and the control strategy are determined. The hardware and software of the control system are also developed and tested in a prototype vehicle. The experiment results show that the control system has good reliability and can satisfy the power requirements of vehicles under all operating conditions.

Study on Modeling and Control Strategy for Electric Drive Motor of Tracked Vehicles

Aimed at the requirements for electric transmission system of a military tracked vehicle, the motor's design indexes were analysed and calculated. A model based on saturate inductance parameter of interior permanent magnet (IPM) synchronous motor was brought forward by using finite element analysis. And its control strategy based on the largest running capability was studied also. The experiment results for a scale model show that the modelling method improves the model's accuracy, and the motor's control strategy is effective.

Research and Implementation of Multi-Point Automatic Synchronization Based on Active Frequency Tracking Control

Reliable connection of turbine generators in complex main wiring structures to the power grid through a plurality of switches is a new key problem,referred to as multipoint automatic synchronization(MPAS),in automatic control systems(ACS).In this paper,different methods of voltage-frequency and phase-difference control are analyzed,and a control methodology based on active frequency tracking(AFT)is presented.Through the establishment of the multi-point automatic synchronization model and the analysis of the governor transfer function with this control method,the important control parameters and automatic process control sequence are summarized.The correctness and effectiveness of the designed methodology are inspected through on-site testing,and the importance of the function and selection of parameters are also explored.

自动泊车前轮转角闭环的分层控制方案

为提高自动泊车系统中控制器的抗扰动能力,优化控制律执行效果,提出了前轮转角闭环的分层控制方案.设计了以行驶距离为非时间参考量的fal函数非光滑控制律,输出前轮转角控制量.以阿克曼转向模型为基础,建立了前轮转角观测器,并使用模糊滑模控制器实现前轮转角闭环的横向控制.搭建Carsim/Simulink联合仿真系统,在典型泊车场景下验证所设计控制器的有效性、跟踪效果及鲁棒性.使用实车测试平台开展了试验.结果表明:所设计的前轮转角闭环分层控制方案能够快速准确地跟踪目标路径,提高了泊车系统的横向控制精度,并在未知转向非线性扰动下也具有良好的跟踪控制效果.

A novel statistically tracked particle swarm optimization method for automatic generation control

Particle swarm optimization(PSO)is one of the popular stochastic optimization based on swarm intelligence algorithm.This simple and promising algorithm has applications in many research fields.In PSO,each particle can adjust its‘flying’according to its own flying experience and its companions’flying experience.This paper proposes a new PSO variant,called the statistically tracked PSO,which uses group statistical characteristics to update the velocity of the particle after certain iterations,thus avoiding localminima and helping particles to explore global optimum with an improved convergence.The performance of the proposed algorithm is tested on a deregulated automatic generation control problem in power systems and encouraging results are obtained.

考虑滑移滑转的双电机履带底盘路径跟踪算法

针对履带底盘田间作业时由于土壤松软、田面不平整导致履带滑移滑转、自动导航路径跟踪精度低的问题,该研究提出了考虑滑移滑转的履带底盘路径跟踪算法,基于履带底盘运动学模型推导出表征滑移滑转特性的转向半径修正系数,并设计了一种基于预瞄模型的模糊控制路径跟踪算法。该方法在纯模糊控制基础上通过预瞄模型确定预瞄点,进而得到横向偏差与航向偏差,同时在常规模糊控制器中引入转向半径修正系数,建立横向偏差、航向偏差、转向半径修正系数三输入模糊控制器。以双电机履带底盘为控制对象,采用高精度RTK-GNSS和MTi-30惯性传感器获取底盘实时位姿信息与角速度信息,进行组合导航。开展了三输入模糊控制器田间U型路径跟踪试验,结果表明,三输入模糊控制器的直线跟踪最大绝对偏差、平均绝对偏差和标准差分别为12.0、3.6和4.4 cm;三输入模糊控制的曲线跟踪最大绝对偏差、平均绝对偏差和标准差分别为21.3、8.6和8.4 cm;为进一步确定本研究算法在履带出现滑移滑转时对路径跟踪精度的提升效果,开展了常规模糊控制器与三输入模糊控制器曲线路径跟踪对比试验,结果表明:当作业速度为0.6 m/s时,常规模糊控制器的最大绝对偏差、平均绝对偏差和标准差分别为31.1、8.3和10.2 cm,三输入模糊控制器的最大绝对偏差、平均绝对偏差和标准差分别为22.4、7.4和9.1 cm,相较于常规模糊控制器,路径跟踪精度分别提高了27.95%、10.84%和10.78%,所设计的三输入模糊控制器可有效降低履带滑移滑转的影响,增强导航系统的控制性能,可为履带底盘在田间松软土壤环境下高精度导航作业提供参考。

自适应时域模型预测控制的轨迹跟踪控制

为了提高自动驾驶车辆轨迹跟踪精度、稳定性和控制器对不同工况的自适应能力,提出了一种模糊自适应预测时域参数模型预测控制轨迹跟踪控制算法。建立车辆运动学模型与模型预测控制器,以实时车速和航向角偏差为模糊输入,通过模糊控制在线优化MPC的预测时域参数和Carsim/Simulink联合仿真,分别在沥青路面和雨雪路面对不同车速的轨迹跟踪控制仿真。仿真结果表明,车辆在沥青路面下,与固定预测时域参数MPC控制器相比,自适应时域MPC控制器纵向绝对偏差均值在低速和高速下分别降低63.16%、55.28%,有效提高了车辆轨迹跟踪精度。车辆在雨雪路面下,低速或中高速时自适应时域控制器最大质心侧偏角均在1°以内,确保车辆控制的鲁棒性。

粗轧板坯自动转钢系统研究与应用

宽厚板生产过程中,其粗轧工艺需控制交叉的锥形辊实现板坯长宽方向的对调,该过程严重依赖人工操作,节奏无法有效控制,制约生产线智能化改造进程。结合视觉检测和自动控制技术设计的粗轧板坯自动转钢系统可有效解决该问题,在粗轧机出入口分别安装视频监控相机,捕捉转钢辊道区域上板坯的状态,利用改进的包含去雾模块的PIDNet(proportional-integral-derivative network)模型提取板坯前景轮廓,通过组合式角度度量方法实时跟踪板坯旋转角度。过程中融合安全限位、位置优选、速度调控、过转修正等策略共同优化转钢控制,保证转钢的安全稳定,自主学习人工经验提升转钢效率。应用结果表明,系统可准确测量板坯角度并实现自动转钢功能,能够替代人工操作,节省能耗,实现智能化生产的目的。

高速动车组数据驱动无模型自适应积分滑模预测控制

同许多复杂系统一样,动车组(Electric multiple unit,EMU)运行过程也具有多变量、强耦合以及非线性等特性,这严重影响着列控系统的性能.针对包含外部扰动的动车组自动驾驶系统,提出一种新型的多输入多输出(Multi-input-multi-output,MIMO)数据驱动积分滑模预测控制(Integral sliding mode predictive control,ISMPC)算法.首先,该算法基于与动车组运行过程等效的全格式动态线性化(Full format dynamic linearization,FFDL)数据模型,设计一种离散积分滑模控制(Integral sliding mode control,ISMC)律.为了使系统能够获得更高的输出跟踪误差精度,利用模型预测控制(Model predictive control,MPC)代替ISMC的切换控制,进一步推导出ISMPC算法.同时,通过对FFDL数据模型的未知扰动、参数误差等不确定项进行延时估计,提升了算法的控制性能和对系统的等价描述程度.在提供两种算法的稳定性证明分析之后,以实验室配备的CRH380A型动车组仿真实验台对提出的ISMC和ISMPC算法进行仿真测试,并与其他方法进行对比,仿真结果表明ISMPC算法控制性能较好,动车组各动力单元速度跟踪误差均在±0.132 km/h以内,满足列车的跟踪精度需求;控制力和加速度分别在[-52 kN,42 kN]和±0.9249 m/s2以内且变化平稳.

基于扩张状态观测器的自动泊车路径跟踪控制

为了消除外界干扰和转向系统运动学模型的不确定性的影响,建立了自动垂直泊车系统的车辆运动学模型,设计了线性扩张状态观测器,该观测器可将系统外界干扰和模型不确定性看作总的扰动量进行观测和补偿,而不需要建立被拉对象的精确数学模型。在此基础上,将扩张状态观测器的值作为滑模控制器的补偿量,用于削弱干扰和不确定对控制器的影响,提高路径跟踪的精度。设定适当的扰动,通过Matlab/Simulink软件仿真,与没有观测器的传统滑模控制相比,验证了该系统跟踪效果的有效性。实车试验结果表明,该路径跟踪控制器能够精确控制车辆完成垂直泊车任务,提出的方法在变速及不确定扰动的泊车情况下具有较好的跟踪控制效果。

互联非线性时滞系统的分散式自适应跟踪控制

为了实现系统对目标轨迹的快速准确跟踪,针对一类互联非线性时滞系统,提出了一种分散式自适应跟踪控制策略。通过使用极限学习机来处理系统中的未知非线性函数,引入Lyapunov-Krasovskii函数来处理未知时滞,结合反演控制技术和动态面控制技术,实现分散式自适应跟踪控制;基于Lyapunov稳定性理论以证明所设计的控制策略可以保证闭环系统跟踪误差一致且最终有界稳定,并借助两级化学反应釜系统验证所提控制策略的有效性。结果表明,所提控制策略能够有效处理系统中的非线性项与系统时滞,实现对目标轨迹的快速准确跟踪。所提策略能克服未知非线性和未知时滞对系统的影响,可为处理复杂非线性时滞系统提供参考。

车辆变速轨迹跟踪横纵耦合控制方法

针对变化速度下车辆轨迹跟踪精度以及实时性差的问题,提出了一种基于模型预测控制的横纵耦合控制方法。在三自由度车辆动力学模型中,将车轮驱动力与前轮转角作为控制量,以单控制器形式实现车辆横纵向运动的综合控制,并且在考虑耦合特性的基础上,设计目标函数与可变权重系数,求解最优横纵向控制量。并且基于五次多项式理论,设计一种变速双移线轨迹以验证控制器综合轨迹跟踪能力。实验结果表明,该控制器能有效跟踪变化车速并且保持高轨迹跟踪精度与良好的实时性。

基于线性自抗扰控制的纵向舰载机直接升力全自动着舰控制

舰载机的最终着舰过程受到强烈的舰尾流的干扰,为了抑制舰尾流扰动,本文提出一种基于径向基函数神经网络(radial basis functions neural network,RBFNN)结合线性自抗扰控制(liner active disturbance rejection control,LADRC)的创新设计方法,确保舰载机直接升力控制自动着舰系统的鲁棒性。LADRC将阵风扰动和系统不确定项作为总扰动,通过线性扩展状态观测器(liner extended state observer,LESO)对总扰动进行估计,并通过线性反馈控制律进行补偿,然后根据系统状态利用RBFNN在线调整LADRC控制器的参数,并构建Lyapunov函数以证明闭环系统的稳定性。舰载机跟踪理想下滑道的仿真结果表明,RBF-LADRC的抗干扰性、鲁棒性和跟踪精度均优于与之对比的控制方法。

谷物联合收获机自动对行控制系统的设计

为提高谷物联合收获机的对行质量,设计了一套谷物联合收获机自动对行控制系统,主要包括自动对行感知系统和路径跟踪控制系统。自动对行感知系统基于多种传感器,包括摄像头、激光雷达和惯性测量单元等,实现了对农田的实时感知和行间距的测量;路径跟踪控制系统通过计算机器相对于理想路径的偏差,并结合速度和转向控制,实现了机器自动调整行驶方向和速度,以保持在行中心。测试结果表明:系统可以稳定、准确地控制机器的对行,显著提高了收割效率和农作物的质量,降低了驾驶员的劳动强度。

基于TI TM4C123的激光追踪系统设计

针对激光目标追踪易丢失、实时性差的问题,该文设计基于德州仪器的TM4C123芯片作为主控的激光目标控制系统与自动追踪,V831摄像头模组作为目标位置反馈测量装置,以二维闭环步进电机云台作为运动输出。摄像头模组通过串口与TM4C主控通信实时反馈目标点位置,使用PID控制算法控制电机输出。同时通过磁编码反馈防止步进电机丢步,实现位置闭环控制,实验结果表明,系统追踪精度高,实时性好。

基于计算机网络算法的智能插秧机控制优化

针对我国插秧机的智能化和自动化控制水平较低的问题,基于计算机网络算法对智能插秧机控制进行了优化。智能插秧机的控制系统主要组成包括单片机、视觉导航装置、自动转向装置、挡位和油门、数据采集系统、通讯装置及发动机等。为了使插秧机能够进行自动导航,首先将插秧机抽象为数学模型,再按照模糊算法和纯追踪算法结合的控制算法对前轮转角求解,使插秧机能够按照预设路径行驶。为了验证该智能插秧机的控制性能,对其进行自动导航控制试验,表明插秧机可以进行有效的自动导航。