Coupled Dynamics and Integrated Control for Position and Attitude Motions of Spacecraft:A Survey

Inspired by the integrated guidance and control design for endo-atmospheric aircraft,the integrated position and attitude control of spacecraft has attracted increasing attention and gradually induced a wide variety of study results in last over two decades,fully incorporating control requirements and actuator characteristics of space missions.This paper presents a novel and comprehensive survey to the coupled position and attitude motions of spacecraft from the perspective of dynamics and control.To this end,a systematic analysis is firstly conducted in details to show the position and attitude mutual couplings of spacecraft.Particularly,in terms of the time discrepancy between spacecraft position and attitude motions,space missions can be categorized into two types:space proximity operation and space orbital maneuver.Based on this classification,the studies on the coupled dynamic modeling and the integrated control design for position and attitude motions of spacecraft are sequentially summarized and analyzed.On the one hand,various coupled position and dynamic formulations of spacecraft based on various mathematical tools are reviewed and compared from five aspects,including mission applicability,modeling simplicity,physical clearance,information matching and expansibility.On the other hand,the development of the integrated position and attitude control of spacecraft is analyzed for two space missions,and especially,five distinctive development trends are captured for space operation missions.Finally,insightful prospects on future development of the integrated position and attitude control technology of spacecraft are proposed,pointing out current primary technical issues and possible feasible solutions.

Relative Position and Attitude Control for Drag-Free Satellite with Prescribed Performance and Actuator Saturation

An adaptive prescribed performance control scheme is proposed for the drag free satellite in the presence of actuator saturation and external disturbances.The relative translation and rotation dynamics between the test mass and outer satellite are firstly derived.To guarantee prescribed performance bounds on the transient and steady control errors of relative states,a performance constrained control law is formulated with an error transformed function.In addition,the requirements to know the system parameters and the upper bound of the external disturbance in advance have been eliminated by adaptive updating technique.A command filter is concurrently used to overcome the problem of explosion of complexity inherent in the backstepping control design.Subsequently,a novel auxiliary system is constructed to compensate the adverse effects of the actuator saturation constrains.It is proved that all signals in the closed?loop system are ultimately bounded and prescribed performance of relative position and attitude control errors are guaranteed.Finally,numerical simulation results are given to demonstrate the effectiveness of the proposed approach.

Design of trotting controller for the position-controlled quadruped robot

This work presents a controller designed for position-controlled quadrupedal dynamic locomotion,aiming at simple and robust trotting control. The controller takes the torso attitude angles and velocities into planning foot trajectories. Firstly design of the servo motor actuated quadruped robot is introduced and the kinematic equations are deduced. Then a scheme is presented for controlling the robot torso attitude based on the virtual leg model. Furthermore,it demonstrates the design of the controller which enables the robot to have a wide range of trotting gaits and omni-directional motions. Finally,results of robust trotting in various speeds,path tracking and push recovery in simulation are reported,and results of trotting on real quadruped robots will be studied.

Research of the algorithm of the closed-loop control system to control the piezoelectric actuator

The piezoelectric actuator has been widely used in precision instruments and precision control. However, hysteresis, nonlinearity and creep exist in the actuator, which limit actuator applications and affect accuracy. This thesis introduces fuzzy control as the algorithm of a closed-loop control system to control the piezoelectric actuator. Fuzzy control can make this closed-looped system not only have high linearity, repeatability, accuracy and few overshoot, but isalso easily used.

Composite anti-disturbance position and attitude control for spacecrafts with parametric uncertainty and flexible vibration

The rendezvous and proximity operations with respect to a tumbling non-cooperative target pose high requirement for the position and attitude control accuracy of servicing spacecraft.However,multiple disturbances including parametric uncertainties,flexible vibration,and unknown nonlinear dynamics degrade the control performance significantly.In order to enhance the system anti-disturbance ability,this paper proposes a composite anti-disturbance control law for the spacecraft position and attitude tracking.Firstly,the relative position and attitude dynamic models with multiple disturbances are established,where the refined descriptions of multiple disturbances are accomplished based on their characteristics.Then,by combining a dual Disturbance ObserverBased Control(DOBC)and a sliding mode control,a composite controller with hierarchical architecture is proposed,where the dual DOBC in the feedforward channel is used to reject the flexible vibration,environment disturbance,and complicated nonlinear dynamics,while the parametric uncertainties are attenuated by the sliding mode control in the feedback channel.Stability analysis is carried out for the closed-loop system by unifying the sliding mode dynamics and observer dynamics.Finally,the effectiveness of the proposed controller is verified via numerical simulation and hardware-in-the-loop test.

Research on a combinatorial control method for coaxial rotor aircraft based on sliding mode

Aiming at the position and attitude tracking of coaxial rotor aircraft(CRA),this paper proposes a combinatorial control method of sliding mode control(SMC)coupled with proportional-integralderivative control(PIDC).Considering the complete description of flight dynamics,aerodynamics and airflow interference,the dynamical model of CRA is established.The dynamical model is simplified according to the actual flight,then the simplified dynamical model is divided into two subsystems:a fully-actuated subsystem and an under-actuated subsystem.The controller of the fully-actuated subsystem consists of a SMC controller coupled with a rate bounded PIDC controller,while the controller of the under-actuated subsystem is composed of a SMC controller.The sliding manifold is defined by combining the position and velocity tracking errors of the state variables for each subsystem.Lyapunov stability theory is used to verify the stability of the sliding mode controller,which ensures that all state trajectories of the system can reach and stay on the sliding mode surface,the uncertainty and external interference of the model are compensated.Simulation and experiment compared with the conventional PIDC are carried out,the results demonstrate the effectiveness and the robustness of the proposed control method of this paper.

面向变构型飞行器的强化学习位置姿态一体化控制方法

针对变构型飞行器在飞行过程中由于构型发生改变导致其质心、气动力、转动惯量和气动力矩以及飞行器的抗扰能力等参数或特性发生变化,对飞行器飞行控制品质产生较大影响的问题,提出一种基于强化学习的变构型飞行器一体化位置姿态控制方法,通过孪生延迟深度确定性策略梯度(TD3)强化学习算法训练神经网络控制律,实现变构型飞行器的一体化位置姿态控制。算法通过数学仿真与飞行试验进行了验证,仿真结果与飞行试验结果表明,该算法所设计的神经网络控制律能够实现变构型飞行器的一体化位置姿态控制,并对于外界干扰具有较强的适应能力。

面向机器人加工复杂轮廓误差控制的策略研究

针对机器人加工复杂曲面零件,提出一种面向加工轮廓误差的控制策略。通过向量的形式定义了机器人加工任务的轮廓误差,结合双向搜索、斐波那契搜索和球面线性插补算法,对机器人轮廓误差进行了估计;在此基础上通过将加权轮廓误差分量补偿到机器人任务空间的速度指令中,设计了机器人加工任务的轮廓控制策略。实验结果表明:对于位置和姿态轮廓误差,估计值与真实值的差异非常小,且与单纯的跟踪控制相比,位置和方向轮廓平均误差大约降低了30%,验证了所提加工轮廓误差控制策略的有效性。

基于预定义时间的四旋翼滑模控制

针对四旋翼位置环和姿态环的控制问题,使得四旋翼位姿能够在预定时间内稳定,提出一种基于预定义时间滑模控制算法的位姿控制器。该控制器通过对四旋翼位置环和姿态环2个环节的控制,使得四旋翼的位姿能够在预定时间内稳定。理论推导及数值仿真表明:所提算法具有正确性;仿真结果表明:应用所提控制器的四旋翼的位置和姿态能够在预定时间内达到稳定。

基于干扰补偿的四旋翼无人机轨迹跟踪控制

针对带有未知外部扰动的四旋翼无人机轨迹稳定跟踪问题,设计了一种基于干扰补偿的控制策略。针对四旋翼无人机位置环设计PID位置控制器,并基于干扰估计器对外部干扰进行补偿。通过姿态解算得到期望姿态,并针对四旋翼无人机姿态环设计具有强鲁棒性能的INDI姿态控制器,通过Simulink进行仿真对比试验。实验结果表明,该控制策略可实现带有未知外部扰动条件下的四旋翼无人机轨迹跟踪能力。

排球训练机器人扣球位姿修正中的解耦控制

因排球训练机器人在扣球位姿控制过程中需要多回路控制,不同控制回路之间相互影响,导致存在不同回路之间的耦合干扰,要获得良好的训练效果,需要对排球训练机器人在扣球训练过程中的耦合干扰进行解耦控制。为此,提出一种针对排球训练机器人扣球位姿修正的解耦控制方法。根据机器人的主要能量和扣球速度独立非线性项计算排球机器人姿态运动参数,采用扩展卡尔曼滤波器,估计机器人在扣球训练过程中的位姿。根据机器人位姿估计结果,建立位姿修正解耦控制的目标函数,并设定扣球位姿控制的约束参量,引入变步长动态平衡反馈调节方法实现单一回路的解耦控制。实验结果表明:这种解耦控制方法在x轴和y轴中的跟踪误差均低于0.3m,在控制过程中的俯仰角、关节旋转角度和加速度变化曲线与设定期望值相符,证明所提方法可有效提高排球训练机器人的跟踪精度和控制效果,获得较好训练效果。

低成本惯性多冗余导航控制一体机设计

为了智能体的精确定位和定姿,实现其稳定运动控制,设计了一种低成本多惯性冗余导航控制一体机,给出了设计方法。稳压电路的开关电源MP2482DN和线性电源JW29300U-3.3V为一体机提供稳定5 V和3.3 V的较大功率电源;控制器STM32H7的SPI采用星形拓扑总线与3片六轴惯性芯片BMI088通信,2路TTL串口与差分卫星定位板双向通信,实现智能体定位和定姿;控制器STM32F4的CAN总线接口与智能体底盘双向通信,实现其运动控制,1路TTL串口实现与控制器STM32H7的双向通信;两控制器的网络接口与上位机组成无线局域网,实现数据交换和状态监控。整个系统具有功耗低、体积小、成本低、接口丰富的特点。

力位协同控制下的机翼壁板定位及柔性调姿技术

调姿过程中受力节点的错误选定会导致机翼壁板的承力能力大幅下降,因此准确定位受力节点才能降低壁板调姿偏差;为此,针对力位协同控制下的机翼壁板定位及柔性调姿技术展开研究;按照力位协同控制原则,建立机翼壁板的力位结构模型;并根据力学协同作用描述条件,求解机翼力位的阻抗作用效果;再通过齐次变换定位坐标的方式,推导具体的机翼壁板定位模型,实现基于力位协同控制的机翼壁板定位;分析机翼壁板的柔性等效力作用,参考调姿位移计算结果,确定位移绝对向量,定义调姿自由点所处位置,并完成柔性调姿目标模型的构建,实现力位协同控制下机翼壁板定位及柔性调姿方法的设计;实验结果表明,上述算法的应用,可将调姿受力节点与标准受力点之间的定位坐标误差控制在3 mm之内,能够解决由错误选定调姿受力节点造成的机翼壁板承力能力下降的问题,符合实际应用需求。

模型不确定和未知扰动下四旋翼无人机位置与姿态控制

在模型不确定和未知扰动下,针对由六个自由度组成的四旋翼无人机控制问题,提出一种自适应滑模控制方法,该方法能实现位置与姿态跟踪控制。首先,根据四旋翼无人机动力学系统,将其分为全驱动、欠驱动子系统,充分考虑无上下限约束的模型不确定和未知扰动,提炼出各子系统的集合干扰项;然后,借助于径向基函数神经网络对包含集合干扰项的等效控制器进行实时逼近和估计,同时运用自适应控制方法估计逼近误差项,设计带有等效控制器和逼近误差项估计值的滑模控制器和对应的自适应更新律,并根据Lyapunov理论,对各子系统状态轨迹所在滑模面的可达性及其收敛性进行了分析说明;最后,所提方法的有效性通过对比仿真得到了验证。

基于多传感器融合的工作面设备定位定姿技术研究

随着科技的发展与进步,煤矿智能化已经成为目前矿业生产中的重点研究方向。但是在薄煤层工作面中由于顶板条件的复杂性以及作业环境的多变性,导致目前的井下自动化控制技术中存在液压支架自动跟机不能完美适应井下顶底板环境且采煤机难以精准定位的问题。以薄煤层工作面自动化控制系统为基础,结合图像识别以及多传感器融合的方法研究采煤机的定位技术,并对液压支架定姿的关键技术进行了分析,期望提高薄煤层自动化系统在煤矿井下的适应性,减少工作面的操作人员,提高煤矿生产的效率。

智能开采装备全位姿测量及虚拟仿真控制技术

针对深部开采复杂地质条件下的综采装备空间位姿及受力动态变化、随机倾斜错动难以描述和自适应控制难题,提出了基于全位姿测量及虚拟仿真控制的智能开采模式,以中煤新集口孜东矿140502工作面地质条件和7 m四柱大采高综采装备参数为基础,构建复杂条件下智能开采装备全位姿测量及虚拟仿真智能控制系统。首先,给出了智能开采“环境装备-仿真模拟-反向控制”运行体系下的智能决策过程,提出了融合视觉的装备全位姿测量、工作面装备位姿一体化描述及驱动关系建模、基于Unity3D的综采虚拟仿真控制等3项支持智能决策的关键技术。随后建立融合视觉的工作面综采装备群全位姿多参数测量系统,提出了基于设备特征点的视觉多参数测量方法,获取描述综采装备群空间全位姿的15个独立参数;给出综采装备群统一坐标描述及驱动模型,建立了特定的全局和局部坐标系、采煤机和刮板输送机位姿驱动关系模型和刮板输送机三维空间弯曲姿态模型;基于Unity3D虚拟仿真技术构建了工作面场景、装备、工艺流程等虚拟实体和关系模型,支撑井下综采装备开采过程运动仿真。开发出与全位姿测量系统通信的底层数据接口,获取装备的实际工况数据,从而驱动仿真模型实现三维场景下的虚实映射。分析计算和模拟优化下一割煤循环装备协同运动及工艺过程,通过反向控制链路实现对装备虚拟模型和实际装备体的闭环控制。实验室测试表明:虚拟仿真系统实现了数据获取、模型解算、单机装备及装备群协同运动仿真,满足装备实际运行逻辑关系,具有对工作面装备运行状态实时监测和反向控制能力,系统运行流畅性满足要求,帧率>20 fps。全位姿测量系统经井下现场测试表明:图像识别检测的支架数大于5架,图像解算时间小于0.5 s,支架顶梁测量角度误差小于1.2°,满足系统数据测量需求。

基于积分滑模的四旋翼飞行器控制系统设计

基于欠驱动、强耦合、非线性小型四旋翼飞行器模型的位置和姿态控制问题,提出一种双闭环积分滑模控制系统。内环为姿态环,采用积分滑模控制,外环为位置环,采用PID控制。由于飞行器的欠驱动性,俯仰角和滚转角的参考值由外环控制器给出。采用李雅普诺夫稳定理论验证了控制器的稳定性,根据Matlab仿真验证了所设计系统的有效性并分析验证了积分滑模控制器的控制特点。

液压支架顶梁位姿调控仿真分析

针对液压支架稳态支护对液压支架控制器自适应控制快速性和强抗干扰能力要求,以ZY10800/28/63支顶掩护式液压支架为研究对象,建立了液压支架运动学模型和阀控液压缸液压系统传递函数,设计了一种包含速度补偿的RBF神经网络控制器,基于该控制器提出了一种液压支架顶梁位姿调控系统,通过控制立柱和平衡千斤顶长度,保证支护状态下液压支架顶梁高度和姿态角稳定。在Matlab/Simulink中建立了液压支架顶梁位姿调控系统仿真模型并进行实验,结果表明:RBF神经网络控制器对阶跃信号的响应时间短,未出现超调现象;在施加顶梁冲击力情况下,RBF神经网络控制器较PID控制器和滑模控制器具有更快的响应速度、更小的超调量和更强的抗干扰能力,能维持支架顶梁位姿处于目标位置,具有良好的稳定性。

基于自适应滑模方法的航天器位置与姿态控制

为了解决存在参数不确定和外干扰的航天器位置与姿态控制问题,提出一种自适应滑模控制方法.该方法用于控制航天器的位置和姿态,确保航天器执行位置与大角度机动,完成捕获和移除大空间目标的任务.提出的控制算法无需不确定的界,比传统的滑模方法容易实现.Lapunov分析表明,设计的控制器保证了位置与姿态的渐近跟踪.最后,将该方法用于航天器的位置与姿态控制,仿真结果验证了方法的有效性.

基于视觉临场感的机器人遥操作系统

介绍了基于视觉临场感的机器人遥操作系统。该系统有机地把视觉临场感技术和机器人遥操作技术结合在一起 ,显著地提高了遥操作系统的性能。系统自主研制了视觉临场感系统 ,在普通的微机上实现了时分多路的立体视觉系统。自主研制了PSD实时测量和位姿解算系统 ,实现了操作者的手部位姿的实时测量。深入地研究了机器人实时跟踪控制的算法 ,并在原有PUMA56 0机器人的基础上改造了核心控制软件 ,实现了机器人对操作者手部运动的实时跟踪。最后完成的演示系统在遥操作性能上比传统的系统有了显著的提高。