四旋翼直升机的滑模控制研究

四旋翼直升机因其优良特性,在军事和民用领域均有广阔的应用前景。为确保其安全稳定飞行,针对周口师范学院自主研制的四旋翼直升机,结合其结构及动力学原理,考虑非匹配不确定性因素的影响,对三自由度四旋翼直升机进行建模。采用线性矩阵不等式技术进行变结构滑模控制系统设计,仿真结果表明,该系统抗参变能力较强,直升机的飞行姿态基本满足控制要求。     

鲁棒自适应控制的靶机蛇形机动控制律设计

针对样例靶机航向不稳定的问题,首先设计了增稳控制律,其次,根据蛇形机动动力学非线性特性,采用线性最优二次型鲁棒自适应动态补偿的混合控制方法,设计了横侧向蛇形机动指令跟踪控制律,实现滚转角和航迹角快速响应的同时兼顾快速消除侧滑角。同时,根据蛇形机动过程中通道之间的耦合效应,进行了解耦补偿控制。通过分析蛇形机动过程中各物理量的运动关系,设计出蛇形机动控制指令。最后,在Matlab/Simulink环境下进行了数值仿真验证,从仿真结果可以看出,蛇形机动控制律可以有效克服外界扰动,维持良好的指令跟踪的响应品质。     

基于增量动态逆的高超声速飞行器控制律设计

针对传统动态逆鲁棒性差的特点,设计了基于增量动态逆的高超声速飞行器的再入鲁棒控制律。首先建立了高超声速飞行器快慢两个回路的控制模型,通过非线性干扰观测器估计再入动力学外来的强干扰,进行前馈补偿;然后通过状态速率反馈,对快慢回路分别设计了增量动态逆控制律,期望动力学采用了抗干扰能力和收敛速度快的非光滑控制律,提高了系统的鲁棒性;引入了线性跟踪-微分器解决了增量动态逆控制律所需状态速率无法测量的问题。最后,通过仿真验证了所提算法的有效性。     

微小型无人直升机动力学建模与仿真

无人直升机动力学建模一直是国内外无人直升机系统研究的重点和难点,对微小型无人直升机动力学建模方法进行了描述。在进行动力学建模时,力求在保持无人直升机动力学特性的基础上采用最小复杂度的模型,并采用simulink工具简化模型开发过程。最后给出了相应的仿真算例,计算结果表明,通过该方法建立的动力学模型可以很方便的用于飞控系统设计。     

新型混联式涂装输送机构的PD滑模控制

针对一种新型混联式汽车电泳涂装输送机构,为解决滑模控制过分依赖于动力学模型的问题、弥补传统PD控制在强耦合强非线性系统中存在的不足,采用时延估计技术对动力学模型进行线性化处理,据此设计一种线性化PD滑模控制器。首先采用拉格朗日法建立机构的动力学模型,然后针对采用时延估计技术线性化的动力学模型设计滑模控制器,同时把时延估计误差作为扰动处理,通过PD控制保证系统的全局渐定稳定。其次,运用Lyapunov稳定性理论证明了所提出控制算法的稳定性,为PD滑模控制律参数的选择提供了准则。最后,分别对滑模控制和PD滑模控制进行MATLAB仿真比较。结果表明,所提出的PD滑模控制方法不仅使系统获得更好的跟踪性能,而且结构简单、易于实现、计算量小,从而实现对新型混联式汽车电泳涂装输送机构的高性能跟踪控制。     

基于FlightGear的直升机可视化飞行仿真系统设计

飞行仿真是直升机控制系统研究中必不可少的一个环节.在VC6.0平台下建立了直升机非线性六自由度动力学模型,飞行控制律和飞行指令遥控台,使用串口使三者进行数据传输;同时借助FlightGear模拟器外部数据的输入/输出接口,将飞行仿真数据通过UDP网络传输,驱动FlightGear可视化引擎,实现飞行仿真中天气条件、飞行姿态和地理环境的三维可视化显示.飞行指令遥控台、飞行控制律、直升机动力学模型及视觉仿真软件这四者构成了一个完整的可视化仿真系统,实现对直升机的总体结构和飞行情况直观形象的显示,从飞机的姿态、位置、轨迹变化中发现存在的问题,对控制策略的设计验证和改善提供一定的帮助.     

无人机空中加油过程中编队飞行控制

针对空中加油中无人机位置保持问题,进行了时变质量UAV的动力学建模与非线性控制设计。综合考虑了燃油传输对UAV的质量、惯性矩阵和质心位置的影响,基于相对于惯性系的状态变量,推导了UAV时变质量动力学方程。分析燃油传输带来的动力学影响,并设计神经网络动态逆控制律来实现UAV的位置保持,通过非线性仿真验证了控制律的有效性。     

基于改进fal函数的无人直升机姿态自抗扰研究

为提高无人直升机的姿态控制能力,针对fal函数拐点处不平滑易引起系统抖振、误差较大时系统增益较大等问题,提出一种改进fal函数,改写非线性误差反馈律,并重新应用于自抗扰控制中得到改进ADRC算法.基于已建立的无人直升机动力学模型,通过Matlab/Simulink进行姿态角跟踪以及在白噪声和阶跃干扰下的抗干扰仿真.仿真...     

PID神经网络在飞控解耦中的仿真研究

在进行飞行控制律设计时,为了获得好的控制品质,有必要对各输出量进行解耦,并且使控制器能根据被控对象动力学特性的改变而自适应调整。为此,介绍了两种PID神经网络解耦控制结构和一种神经网络辨识器,并分别给出了PID神经网络解耦控制器和辨识器的前向算法及反向传播算法;最后分别应用两种解耦方法针对飞机横侧向线性模型进行计算仿真,得到了两种解耦结果;证明了PID神经网络解耦控制的有效性,并比较了两种结构的优缺点。     

结构自适应反步容错控制器设计

基于一类由状态空间描述的非线性系统固有的结构级联特性,在飞行器发生卡死故障的情况下,设计了基本控制律加补偿控制律的控制器结构形式,补偿故障对系统性能造成的影响。提出了确保对参考模型精确跟踪的控制器结构和条件。控制器的基本控制律部分是利用系统的结构特性设计反步(backstepping)控制律,系统发生未知卡死故障时,利用实际对象和参考模型之间的误差,更新控制器的故障补偿部分。控制器同时保证了闭环系统的稳定性和参考模型状态跟踪误差渐近性。仿真结果表明了该控制律对给定参考模型跟踪的有效性。     

Backstepping boundary control of flexible-link electrically drivengantry robots

Gantry robots are used for precision manufacturing and material handling in the electronics, nuclear, and automotive industries. Light, flexible links require less power, but may vibrate excessively. An implementable boundary controller is developed to damp out undesirable vibrations in a flexible-link gantry robot driven by a brushed DC motor. Hamilton's principle produces the governing equations of motion and boundary conditions for the flexible link. The electrical subsystem dynamics for a permanent magnet brushed DC motor couple with the link dynamics to form a hybrid system of partial and ordinary differential equations. A boundary voltage control law is developed based on Lyapunov theory for distributed parameter systems. Through an embedded desired-current control law, the integrator backstepping controller generates the desired control force on the mechanical subsystem. A velocity observer estimates the gantry velocity, eliminating one feedback sensor. Modal analysis and Galerkin's method generate the closed-loop modal dynamics. Numerical simulations demonstrate the improved vibration damping characteristics provided by the backstepping boundary control law. Experimental results confirm the theoretical predictions, showing the high performance of backstepping boundary control     

Modeling and control of steering system of heavy vehicles for automated highway systems

This work presents modeling, analysis, and controller design of the steering subsystem of heavy vehicles as a subsystem of vehicle lateral control system for the automated highway systems. A physical model of the steering subsystem is derived where the hydraulic power assist unit is modeled as a family of static nonlinear boost curves. Based on open-loop frequency tests and analysis of the physical model structure and its dynamical characteristics, a nominal second order linear model of the steering subsystem is obtained. Then, a linear robust loop-shaping controller is designed to provide a good tracking performance of the closed-loop dynamics of the steering subsystem for varying gain cross over frequencies which is a result of the nonlinear characteristics of the hydraulic power assist. The controller has been successfully incorporated as an inner-loop controller into the nested lateral control architecture for autonomous driving and its efficacy has been demonstrated experimentally.     

一种基于STM32的航模直升机飞控系统设计

介绍了一种以STM32微控制器为核心,基于多传感器检测和自适应PID算法的航模直升机飞行控制系统的设计方案。在分析了航模直升机的操作系统结构的基础上,建立了航模直升机在悬停和低速飞行时的动力学模型。并在该动力学模型的基础上设计了姿态控制、航向控制。最后通过对仿真数据和试飞数据的对比分析,表明系统设计的正确性和可行性。     

Precision grip force dynamics: a system identification approach

A linear model of the dynamics of the human precision grip is presented. The transfer function is identified as representing the peripheral motor subsystem, from the motoneuron pool to the final production of a grip force between the tip of the index finger and the thumb. The transfer function captures the limiting isometric muscle dynamics that, e.g., cortical motor areas have to act through. When identifying the transfer function we introduce a novel technique, common subsystem identification. This characterizes a specific subsystem in a complex biomechanical system. This technique requires data from two functionally different experiments that both involve the subsystem of interest. Two transfer functions, one for each experiment, are then estimated using a linear black box technique. The common mathematical factors, represented by poles and zeros, are used to form a new transfer function. It is concluded that this transfer function represents the common biological subsystem involved in both experiments. Here, we use one active and one reactive isometric grip force experiment to capture the subsystem of interest, i.e., the motoneuron pool, motor units, muscles, tendons and fingertip tissue. The characteristics of the dynamics are in agreement with previously published experiments on human neuro-muscular systems. The model, H(s) = 280/(s2 + 22s + 280), is well suited for the representation of a force producing end-effector in simulations including a control system with sensory feedback.     

机动塔台管制系统总体设计

直升机/无人机具有飞行灵活性强、反应速度快、可进行野外起降等特点,而机动塔台管制系统对飞行员日常训练、空中交通管制、指挥调度和飞行保障等具有重要作用。介绍了机动塔台管制的任务和作用,提出其建设思路和方法,描述了其主要功能和技术体系结构,对硬件、软件物理组成进行了设计。通过计算机仿真进行分析,探讨了多模交互模型IMM在自动相关监视ADS数据与雷达数据融合应用的可行性。     

一种基于STM32的航模机飞控系统设计

摘要：介绍了一种以STM32微控制器为核心,基于多传感器检测和自适应PID算法的航模直升机飞行控制系统的设计方案。在分析了航模直升机的操作系统结构的基础上,建立了航模直升机在悬停和低速飞行时的动力学模型。并在该动力学模型的基础上设计了姿态控制、航向控制。最后通过对仿真数据和试飞数据的对比分析,表明系统设计的正确性和可行性。     

Adaptive robust precision motion control of linear motors withnegligible electrical dynamics: theory and experiments

This paper studies the high performance robust motion control of an epoxy core linear motor, which has negligible electrical dynamics due to the fast response of the electrical subsystem. A discontinuous projection based adaptive robust controller (ARC) is first constructed. The controller theoretically guarantees a prescribed transient performance and final tracking accuracy in general, while achieving asymptotic tracking in the presence of parametric uncertainties. A desired compensation ARC scheme is then presented, in which the regressor is calculated using the reference trajectory information only. The resulting controller has several implementation advantages such as less online computation time, reduced effect of measurement noise, a separation of robust control design from parameter adaptation, and a faster adaptation rate. Both schemes are implemented and compared on an epoxy core linear motor. Extensive comparative experimental results are presented to illustrate the effectiveness and the achievable control performance of the two ARC designs     

Tracking and Vibration Control of Flexible Robots Using Shape Memory Alloys

This paper considers the tracking control problem for flexible robots with active vibration suppression by shape memory alloys (SMAs). With a singular perturbation technique, the flexible modes and joint angles are modeled as fast and slow variables, respectively. The fast subsystem comprising the nonlinear SMA dynamics is obtained in a strict feedback form feasible for the backstepping design. The SMA actuators are configured in redundant pairs for an active suppression of vibrations. For the slow subsystem, asymptotically stable tracking is ensured, while for the fast subsystem, uniform exponential stability is guaranteed. By invoking Tikhonov's theorem, it is shown that the error arising from the nonideal time-scale separation in the singular perturbation model is small. Simulation demonstrates the effectiveness of the proposed control     

Fuzzy Multi-model Switching H-Infinity Control for Helicopters in a Full Envelope

This paper presents a fuzzy multi-model switching H-infinity control law for a helicopter in a full envelope. The space of the nonlinear model for a helicopter is partitioned to some sub-spaces of the multiple linearized models using the fuzzy set theory. We use the genetic algorithm to design a local H-infinity controller for each linearized model of the helicopter at the different equilibrium point. The fuzzy logic strategy can handle smoothly the controller switching of the linearized models of the helicopter. The flight controller for the helicopter is synthesized using the proposed control law design technique. The simulation and performance evaluation show that the designed helicopter flight control can guarantee the smooth switching of control laws of the helicopter.     

Vibration-free position control for a two degrees of freedom flexible-beam sensor

This work presents a position control for a two degree of freedom flexible-beam made of a composite material, whose aim is to control the tip of the flexible-beam by decreasing the vibration when the beam moves. A mechatronic unit that uses a multi-axis force/torque sensor has been specially designed and we propose to control the system by using a reduced dynamic model. The control method makes use of an inner-loop to control the position of two servo-motors, by means of PID regulators, and an outer-loop that cancels the tip vibration. Moreover, the closed-loop motor dynamics has been reduced by using a series connection of filters that invert its dynamics. The motor controllers have proved to be fast and precise, and cancel the non-modelled components of the motor friction without the need for a previous estimation. The flexible-beam vibration has been controlled by implementing an input-state feedback linearisation which includes compensation terms for the nonlinear beam dynamics, a linear feedback control law and a full state estimator. The experimental validation of the complete control method showed a significant trajectory tracking of the tip, while vibrations were prevented.