Adaptive state-constrained/model-free iterative sliding mode control for aerial robot trajectory tracking

This paper develops a novel hierarchical control strategy for improving the trajectory tracking capability of aerial robots under parameter uncertainties.The hierarchical control strategy is composed of an adaptive sliding mode controller and a model-free iterative sliding mode controller(MFISMC).A position controller is designed based on adaptive sliding mode control(SMC)to safely drive the aerial robot and ensure fast state convergence under external disturbances.Additionally,the MFISMC acts as an attitude controller to estimate the unmodeled dynamics without detailed knowledge of aerial robots.Then,the adaption laws are derived with the Lyapunov theory to guarantee the asymptotic tracking of the system state.Finally,to demonstrate the performance and robustness of the proposed control strategy,numerical simulations are carried out,which are also compared with other conventional strategies,such as proportional-integralderivative(PID),backstepping(BS),and SMC.The simulation results indicate that the proposed hierarchical control strategy can fulfill zero steady-state error and achieve faster convergence compared with conventional strategies.

Study on Steering Control Strategy for High-Speed Tracked Vehicle with Hydrostatic Drive

Steering control strategy for high-speed tracked vehicle with hydrostatic drive is designed based on analyzing the fundamental steering theories of the hydrostatic drive tracked vehicle. The strategy is completed by the cooperation between integrated steering control unit and pump ＆ motor displacement controller. The steering simulation is conducted by using Simulink of Matlab. It is indicated that this steering control strategy can reduce the average vehicle speed automatically to achieve the driver＇s expected steering radius exactly in the case of en- suring not exceeding the system pressure threshold and no sideslip.

Control strategy for hybrid tracked vehicles using fuzzy logic

To solve the problem of power distribution for hybrid tracked vehicles （HTV）, a supervi- sory control strategy is proposed. Firstly, power system integration is analyzed and modeled. Then the control algorithm is given. Two fuzzy logics are used to realize the coordination control over each power unit. One controls power distribution based on the load power and battery state of charge （SOC）. The other manage the power during regenerating braking. To validate the presented control strategy, a ＂driver and controller＂ in the loop simulation platform is built based on dSPACE system and real-time simulation is made. The simulation results show that the strategy presented can solve the power distribution problem of hybrid tracked vehicles correctly and effectively.

智能车横向跟踪控制模式切换策略及评价方法

针对智能车横向跟踪控制算法传统切换策略中模型匹配策略总是处于激活状态,占用计算资源和运动平顺性变差的问题,设计了一种基于最小二乘支持向量机(least squares support vector machine,LSSVM)的控制模式切换策略,在不同工况下根据误差判断策略切换控制模式.从安全性、舒适性和跟踪精度3个方面构建控制效果评估函数,并根据多目标优化数学模型实时执行系统最优控制量.仿真试验结果表明:该切换策略能够保证智能车在不同工况下具有优秀的横向跟踪性能,路径跟踪偏差范围为±0.1 m,横摆角速度波动范围为±2(°)/s,jerk值的范围为±10 m/s^(3),与传统的单一控制算法相比,具有更好的跟踪精度、稳定性和舒适性.

基于漏斗函数双电机伺服系统跟踪与同步控制

针对双电机驱动伺服系统具有未知非线性的问题,提出一种基于漏斗函数的跟踪与同步控制方案。首先,利用神经网络逼近和补偿复杂的非线性,在此基础上,引入滤波技术解决传统反步控制的“计算爆炸”问题,同时引入非光滑漏斗误差面确保系统的状态量被约束在预定义的漏斗边界内,结合改进的漏斗函数和反步设计技术设计了一种自适应量化漏斗跟踪控制方案。为了同时保证双电机的同步运行,同步控制器采用了平均偏差耦合策略,实现了双电机伺服系统的跟踪与同步控制。仿真结果表明,该方法可以实现对负载的跟踪以及双电机的同步。

售货机升降系统S型速度控制策略

在传统三闭环控制方式下,售货机升降接货系统易因启停过程中加速度突变产生冲击,导致系统运行不平稳。针对这一问题,文中对传统升降系统加减速控制策略进行改进,加入前馈和微分负反馈,提出一种S型速度曲线控制算法。根据路径规划判别条件将S型速度曲线分为七段式、六段式和四段式3种,并给出各路径约束条件下的参数求解方法和具体执行流程。将该算法运用到升降控制系统中进行仿真和实际工况测试,实验结果表明,与传统三闭环控制相比,文中所提控制策略可以提高售货机升降系统运行的平稳性,减小冲击,使速度曲线更加柔和,并能够保持较好的跟踪性能。

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。

无人驾驶铰接转向车辆路径跟踪控制研究综述

路径跟踪是无人驾驶技术的重要组成部分,是实现铰接转向车辆准确平稳自主行驶的关键,对提高铰接转向车辆在农业、林业、矿山及建筑等行业的作业效率和安全性具有重要意义。车辆模型构建、控制算法设计和算法验证评估是路径跟踪控制研究的基础,围绕这3方面阐述了铰接转向车辆路径跟踪控制研究的进展。首先回顾了铰接转向车辆的几何学模型、运动学模型和动力学模型,并讨论了各类模型在路径跟踪控制研究中的适用场景及局限性;在此基础上,阐述了铰接转向车辆路径跟踪控制算法的研究现状,对比并总结了每种算法的优缺点及适用范围,并进一步归纳了算法的验证与评估手段;最后展望了铰接转向车辆路径跟踪技术未来的研究重点及方向:考虑车辆动力学因素及模型参数动态时变特性的车辆建模研究;融合各类算法适应性并结合智能算法的多工况自适应控制算法设计;标准化、流程化的高保真仿真场景开发及集成准确性、稳定性、安全性等多性能的评估方法研究。

基于Levy-AVOA优化模糊PID的动力定位船舶循迹控制研究

为了提高动力定位(DP)铺缆船在铺设海底电缆时的路径循迹能力,设计非洲秃鹫算法优化模糊PID的船舶控制器(AVOA-Fuzzy-PID)。船舶运动数学模型采用三自由度,加入风、浪、流作用力模拟海况,以船舶的位置和姿态矢量与实际值的差值作为控制器输入。在传统PID控制器基础上加入模糊控制,根据模糊控制规则寻求K_(p)、K_(i)、K_(d)的调整变化量ΔK_(p)、ΔK_(i)、ΔK_(d)与e和de间的关系,自动调节参数,加强控制器稳定性,使船舶沿规划路径向目标位置航行。采用非洲秃鹫算法结合Levy飞行策略计算船舶模型,通过确定每组最优秃鹫、秃鹫饥饿率、探索和开发4个阶段,并在开发阶段引入Levy飞行策略,增强全局搜索能力,确定秃鹫食物源最优位置,防止结果陷入局部最优,提高计算结果精确性。仿真结果表明,结合AVOA算法的模糊PID控制器能够提高船舶路径跟踪效率,使其跟踪过程较为平顺。通过对比PSO、GA和SSA算法优化Fuzzy-PID控制器参数可以看出,AVOA对K_(p)、K_(i)、K_(d)参数整定收敛速度较快,控制器适应度值较低,寻优精度较高,能够使船舶沿规划路径航行。

沙漠光伏发电站跟踪系统的设计应用与创新研究

为了提升光伏发电在荒漠治理中的应用,文章针对沙漠光伏电站中的平单轴跟踪系统的安装布置,控制系统设计,对地面的透光率以及结构防风沙设计等方面展开研究,提出了适用于沙漠电站的跟踪系统的关键技术,使跟踪系统在精准跟踪太阳,保持最大功率输出的同时,进一步适应沙漠光伏电站,特别是光伏与林业结合的综合治理电站。

考虑风光出力不确定性的风光储微电网系统智能协调控制策略

对风光储互补的微电网发电系统进行研究,针对风光发电与负载功率不匹配问题,提出了一种基于新型变步长电导增量法的最大功率点追踪控制方法,利用基于Ziegler-Nichols法的改进自适应PID算法实现负载功率蓄电池充放电控制的协同控制策略。通过在MATLAB/Simulink中搭建仿真模型并进行验证,证明了所述方案的准确性以及可行性。

基于Fourier拟合的光伏跟踪系统设计

[目的]为提高光伏支架的发电效率,以基于Fourier拟合算法的视日运动轨迹光伏跟踪器为研究设计对象。[方法]借助MATLAB分析了传统视日运动轨迹算法的跟踪精度情况,更进一步地在此基础上提出了精度更优的8阶傅里叶拟合视日运动轨迹跟踪算法,并结合GNSS定位技术,得出太阳实时运行轨迹。系统设计以STM32单片机作为微处理器,采用6轴加速度传感器,通过重力矢量在其轴上的投影确定光伏跟踪支架的实时倾斜度,以此二者建立跟踪支架三维运行模型,通过分析太阳光线在支架上的余弦效应即可得到电机需要运行的动作角。同时为解决晨昏时刻光伏组件间的阴影遮挡问题,系统增加逆跟踪算法。并考虑到大规模机组的应用,提出主从电机同步控制策略。[结果]傅-2里叶拟合算法拥有更高的跟踪精度,精度可达到10数量级,高于传统算法一个数量级。同时采用逆跟踪技术可节约24.3%光伏阵列用地面积,大幅提高了土地利用率。[结论]本研究采用更为精准的视日运动轨迹跟踪模型,较好地解决了太阳辐射利用的余弦效应,提升了电站的发电效率,实现了安全高效绿色能源体系的建设,促进了我国“双碳”目标的推进与达成。

高效光伏反向变流器在光伏发电系统中的应用优化与性能分析

光伏发电作为一种清洁能源技术,在可再生能源领域具有广阔的应用前景。光伏反向变流器作为光伏发电系统的核心组件之一,对系统的性能和效率至关重要。文章针对光伏反向变流器在光伏发电系统中的应用优化与性能分析进行了深入研究。通过分析反向变流器的原理和结构,探究最大功率点跟踪(Maximum Power Point Tracking,MPPT)技术、控制策略、参数优化以及效率提升与损耗降低策略等优化方法。同时,结合性能分析与实验验证,对不同优化策略的效果进行评估和验证。研究结果为光伏发电系统的设计和运行提供了重要参考,有助于提高系统的性能和效率。

A novel explosion-proof walking system: Twin dual-motor drive tracked units for coal mine rescue robots

A new explosion-proof walking system was designed for the coal mine rescue robot(CMRR) by optimizing the mechanical structure and control algorithm. The mechanical structure innovation lies mainly in the dual-motor drive tracked unit used, which showed high dynamic performance compared with the conventional tracked unit. The control algorithm, developed based on decision trees and neural networking, facilitates autonomous switching between "Velocity-driven Mode" and "Torquedriven Mode". To verify the feasibility and effectiveness of the control strategy, we built a self-designed test platform and used it to debug the control program; we then made a robot prototype and conducted further experiments on single-step, ramp, and rubble terrains. The results show that the proposed walking system has excellent dynamic performance and the control strategy is very efficient, suggesting that a robot with this type of explosion-proof walking system can be successfully applied in Chinese coal mines.

Optimal control strategy for energy saving in trains under the four-aspect fixed autoblock system

This paper deals with both the leading train and the following train in a train tracking under a four-aspect fixed autoblock system in order to study the optimum operating strategy for energy saving. After analyzing the working principle of the four-aspect fixed autoblock system, an energy-saving control model is created based on the dynamics equation of the Wains. In addition to safety, energy consumption and time error are the main concerns of the model. Based on this model, dynamic speed constraints of the following train are proposed, defined by the leading gain dynamically. At the same time, the static speed constraints defined by the line conditions are also taken into account. The parallel genetic algorithm is used to search the optimum operating strategy. In order to simplify the solving process, the external punishment function is adopted to transform this problem with constraints to the one without constraints. By using the real number coding and the strategy of dividing ramps into three parts, the convergence of GA is accelerated and the length of chromosomes is shortened. The simulation result from a four-aspect fixed autoblock system simulation platform shows that the method can reduce the energy consumption effectively in the premise of ensuring safety and punctuality.

OUTPUT MAXIMIZATION CONTROL FOR VSCF WIND ENERGY CONVERSION SYSTEM USING EXTREMUM CONTROL STRATEGY

The energy conversion optimization control strategy is presented for a family of horizontal-axis variablespeed fixed-pitch wind energy conversion systems,working in the partial load region.The system uses a variablespeed wind turbine(VSWT)driving a squirrel-cage induction generator(SCIG)connected to a grid.A new maximum power point tracking(MPPT)approach is proposed based on the extremum seeking control principles under the assumption that the wind turbine model and its parameters are poorly known.The aim is to drive the average position of the operation point close to optimality.Here the wind turbulence is used as search disturbance instead of inducing new sinusoidal search signals.The discrete Fourier transform(DFT)process of some available measures estimates the distance of operation point to optimality.The effectiveness of the proposed MPPT approach is validated under different operation conditions by numerical simulations in MATLAB/SIMULINK.The simulation results prove that the new approach can effectively suppress the vibration of system and enhance the dynamic performance of system.

风电跟踪调度计划时降低寿命损耗的电池储能分组控制策略

为了解决风电跟踪调度计划过程中电池寿命损耗较高的问题,提出了降低寿命损耗的电池储能分组控制策略。利用设计的基于改进天牛须搜索算法的旋转门算法得到最优压缩偏移量,进而提取风电趋势;将风电场配备的电池储能分为电池组1和电池组2,并将电池组2进一步细分为3个电池簇,在避免充放电能量对冲的条件下根据风电趋势计算两电池组的功率调节指令,并基于此确定两电池组的容量,进而以电池单元的动作次数最少为目标获取3个电池簇的容量;在初始时刻及荷电状态越限时刻对电池单元进行动态分组,并根据电池单元的依次启动方法确定电池组1中电池单元的功率调节指令,基于设计的双层功率分配方法确定电池组2中电池单元的功率调节指令;电池单元在满足运行约束的条件下响应各自的功率调节指令。将所提控制策略与其他控制策略进行仿真对比,结果表明所提控制策略能以更大的程度降低寿命损耗、延长储能的使用寿命。

基于VMD和MPC的电动汽车-火电机组联合调频控制

合理的调频指令分配策略以及有效的指令跟踪控制方法是利用集群电动汽车(aggregate electric vehicle,AEV)联合火电机组开展调频控制、改善调频质量、提高调频经济性的关键。基于此,文中提出基于变分模态分解(variational mode decomposition,VMD)和双层模型预测控制(model predictive control,MPC)的AEV参与系统调频控制策略。首先,设计AEV联合传统火电机组的频率协调优化控制结构,建立火电机组及负荷频率控制模型,同时将AEV转化为虚拟调频单元,构建在AEV参与下系统单区域多机组负荷频率控制模型;然后,利用VMD将电网调频指令信号分解为含不同频率成分的本征模态函数,整合高频分量作为AEV的调频指令,低频分量作为火电机组群的调频指令,并通过双层MPC分别在AEV和火电机组群内部实现调频指令的优化再分配及跟踪控制;最后,对所提控制策略进行仿真验证。结果表明所提控制策略可实现对系统频率的有效调节,且兼顾了调频的经济性和动态性能。

基于Fuzzy-PI的直驱永磁风力发电系统MPPT控制

通过对模糊PI控制算法、MPPT算法分析,并对变流器的控制策略进行推导,提出基于Fuzzy-PI控制策略,确定机侧以转速的偏差及其微分为输入,交轴电流为输出,风机达到最大功率跟踪效果;网侧变流器采用电压外环、电流内环双闭环控制策略。通过Simulink系统仿真,结果表明模糊PI控制系统能实现发电机的最大功率跟踪和单位功率因数运行,控制效果优于传统的PI控制策略。

基于后轮转角综合约束策略的4WIS车辆控制方法

为提高4WIS车辆轨迹跟踪精度与操作稳定性,提出了基于横摆角速度、质心侧偏角和侧滑分析的后轮转角综合约束策略.依照此策略,采用了纵向预瞄速度控制器和横向MPC控制器,嵌入纵向速度PID控制完成横纵向运动的解耦,并结合转矩分配控制器,形成了4WIS综合控制方法.使用Carsim和Matlab/Simulink建立了联合仿真模型,以前轮转向和4WIS一般控制方法作为对照,在U形弯道掉头工况与高速换道工况下进行仿真实验.仿真结果验证了后轮转角综合约束策略的有效性和可靠性,4WIS综合控制方法提高了车辆的灵活性和稳定性,并具有更高的轨迹跟踪精度.