舵减摇控制系统的开环增益成形设计

针对船舶航向/舵减横摇控制系统的特点,提出了一种新的设计方案.对舵减横摇控制回路,基于开环增益成形的思想,通过指定闭环灵敏度函数的幅频特性形状,得到相应的舵减横摇控制器.在设计过程中不但考虑了对象的非最小相位特性,还分析了Bode积分定理对性能的约束条件,在系统的性能和控制输出之间进行了折衷,给出了一组优化设计结果.对航向控制回路,应用混合灵敏度问题设计了H∞航向控制器.设计指标是在保证船舶能很好的跟踪航向指令的前提下尽可能的减小艏摇控制回路和横摇控制回路之间的耦合作用.仿真结果表明,所设计的舵减摇控制系统满足性能要求,取得了较高的减摇率,而且横摇运动对航向的影响很小.通过对摄动后的对象进行仿真,进一步验证了系统具有很好的鲁棒性.     

Robust control law design for lateral-directional modes of an F-16/MATV using μ-synthesis and dynamic inversion

A manual flight control system for the lateral-directional dynamics of a modern fighter aircraft incorporating thrust vectoring is presented. Design goals are posed in terms of maintaining acceptable flying qualities during high angle of attack (α) manoeuvring while also achieving robustness to model parameter variations and unmodelled dynamics over the entire flight envelope. The need for gain scheduling a dynamic controller is eliminated by using an inner loop dynamic inversion/outer loop structured singular value (μ)-synthesis control structure which separately addresses operating envelope variations and robustness concerns, respectively. Performance objectives are based on commanding sideslip angle and stability axis roll rate. Realistic representations of both structured (real parametric) and unstructured uncertainty are included in the design/anlysis process. A flight condition dependent control selector maps generalized controls to physical control deflections, considering actuator redundancy, effectiveness and saturation issues. An angle of attack dependent command prefilter shapes commands to produce desired responses. Structured singular value analysis, low-order equivalent system (LOES) fits, and linear step responses demonstrate satisfaction of design goals. Simulation shows excellent control at both low and high angles of attack. © 1997 John Wiley & Sons. Ltd.     

偏置动量轮控卫星姿态控制

研究了轮控的三轴稳定的偏置动量卫星姿态控制问题。卫星的俯仰回路采用偏置动量轮，滚动／偏航轴上各安装一个反作用飞轮来完成姿态控制。小姿态角下俯仰回路可以单独设计，利用测量的俯仰角来实现其姿态控制；滚动／偏航回路利用滚动信息，采用基于偏航观测器的滑模控制器设计。磁力矩器提供的磁矩与地磁场作用产生的力矩实现了飞轮的动量卸载。对卫星姿态控制系统进行的仿真研究结果表明，所设计的控制方案在飞轮输出力矩工作范围内，可使卫星达到很高的姿态控制精度。     

基于Anti-windup PID的四旋翼飞行器姿态控制研究

针对四旋翼飞行器姿态控制问题,设计一种Anti-windup PID姿态控制器。结合四旋翼飞行器简化的数学模型,在飞行器在垂直速率、俯仰速率、翻滚速率、偏航速率4个独立通道上分别设计了PID控制器和Anti-windup PID控制器。在MATLAB/SIMULINK环境下,对控制四旋翼飞行器姿态的两种算法进行仿真分析。仿真结果表明,Anti-windup PID控制方法在性能上明显优于PID,对飞行器有良好的控制效果。用Anti-windup PID算法搭建的四旋翼飞行器的物理实验平台更好地验证了该算法的有效性。     

Design of a robust controller for a supersonic aircraft using H∞ approach

In this paper an H_∞ optimal, robust flight control system design for a supersonic aircraft has been described. Separate controllers are designed for longitudinal and lateral motions. A general two-degrees-of-freedom controller is proposed, where feedback control is designed for robust performance augmentation, while a series compensator is used to ensure that requisite handling qualities. Three alternative methods to achieve performance robustness have been discussed. The results obtained are very encouraging. It is hoped that this will equip the flight control engineers with an alternative to the conventional methods.     

冷轧机的轧辊偏心鲁棒重复控制

设计了用于冷轧机的轧辊偏心补偿的鲁棒重复控制器.首先根据对象的期望闭环特性及扰动信号频率,确定低通滤波器的截止频率,然后通过引入状态反馈来保证闭环系统的鲁棒稳定性,把重复控制器的设计问题转化为H∞状态反馈控制器的设计问题,给出了控制器参数整定算法,最后通过在控制系统中引入一个前向系数来进一步改善和提高系统的动态性能与稳态控制精度,给出了前向系数的整定方法.仿真结果表明,当系统对象参数存在摄动时,这种控制器仍然能够实现对轧辊偏心的高精度补偿.     

Aircraft load alleviation by robust yaw-lateral decoupling

In an engine out/engine failure of an aircraft the human pilot has to compensate a yaw disturbance torque. Because of a delayed reaction possibly followed by an overreaction the pilot may cause high loads (shear forces) at the vertical tail. These shear forces determine the static design of the vertical tail in some areas and its structural weight. Such a situation and a corresponding weight increase can be avoided by an automatic yaw control system. It achieves a precise and early yaw moment compensation faster than the pilot can do it. To tackle both the load alleviation and the handling problem within the controller design, the yaw rate is made robustly non-observable from the lateral acceleration at a decoupling point and approximately from the shear force at the vertical tail. The parameters of the robust controller can be derived analytically. Nonlinear high precision simulations show that a significant load alleviation at the vertical tail is achieved and that the handling and the passenger comfort are improved.     

Precompensation decoupling control with H∞ performance for 4WS velocity-varying vehicles

In this paper, a new decoupling control strategy with H_∞ performance for the three-degree-of-freedom model, including the longitudinal velocity, the lateral velocity, and the yaw rate is presented and discussed. A sliding mode controller only depending on the longitudinal velocity for the longitudinal system and a precompensation decoupling controller with H_∞ performance for the steering system are designed. These controllers are established by feeding back longitudinal velocity and yaw rate, thus observation or measurement for the lateral velocity is not required. Simulation results show that our strategy can improve the handling characteristics, safety, and comfort significantly.     

Hybrid attitude control in steering maneuver using ARC Hil setup

This paper presents the design of an active roll controller for a vehicle and an experimental study using an electric actuating roll control system. Firstly, based on a three degrees of freedom linear vehicle model, the controller is designed using lateral acceleration and rollrate feedback. In order to investigate the feasibility of an active control system, experimental work is carried out using a hardware-in-the-loop (Hil) setup which has been constructed using the devised electric actuating system and the full vehicle model including tire characteristics. The performance is evaluated by an experiment using the Hil setup in which steering maneuvers are carried out. Finally, in order to enhance the control performance in a transient region, the hybrid control strategy is proposed and evaluated.     

基于飞轮的偏置动量卫星周期干扰补偿方法

为了提高偏置动量卫星姿态控制精度,针对三轴稳定偏置动量卫星滚动/偏航回路周期干扰力矩补偿问题,提出了一种基于反作用飞轮的滚动/偏航回路周期干扰力矩补偿方案.采用频率分离法,分析了周期干扰力矩对卫星滚动/偏航回路姿态控制精度的影响.设计了周期干扰力矩的飞轮补偿方案,该干扰力矩补偿方案由安装在卫星滚动/偏航轴上的反作用飞轮实现.仿真结果表明,所设计的飞轮补偿方案提高了滚动/偏航轴的控制精度,从而验证了飞轮补偿方案的可行性和有效性.     

基于RFID技术的四旋翼无人机轨迹跟踪控制系统设计

为促进四旋翼无人机的飞行自主性,增强无人监管情况下飞行器主机所具备的避障行进能力,设计基于RFID技术的四旋翼无人机轨迹跟踪控制系统;采用RFID标签识别技术,调制处理既定控制信号,利用标签识别协议,连接微型四旋翼轨迹控制器与内环姿态控制器,通过数据通信链路,提取轨迹跟踪控制所需的传输电子量,完成轨迹跟踪控制系统硬件设计;利用动力系统中的参数辨识策略,确定与轨迹姿态控制相关的物理规律标注,实现四旋翼无人机轨迹跟踪控制;实验结果表明,与机器视觉型控制系统相比,基于RFID技术的控制系统的SSI避障行进指标数值相对较高,全局最大值达到了 79％,四旋翼无人机滚转角平均值为85°,能够有效抑制四旋翼无人机滚转角的数值上升趋势,增强无人监管情况下飞行器主机避障行进能力.     

基于终端滑模的四旋翼飞行器非线性轨迹跟踪控制

考虑到四旋翼飞行器的传统内外环控制策略依赖时标分离假设,稳定性分析复杂,并且控制参数选取困难的缺点,提出了一种与传统内外环控制策略不同的轨迹跟踪控制器;首先将四旋翼飞行器数学模型进行相应的变换,以分解为高度、偏航角和纵横向三个级联的子系统,再使用终端滑模控制方法设计高度和偏航角子系统的控制器,使两个子系统的状态误差可以在有限时间内收敛到原点,之后基于变量非线性变换设计纵横向子系统的控制器,分析了闭环系统稳定性,证明了所设计的轨迹跟踪控制器可以保证闭环系统跟踪误差渐近稳定到原点,最后仿真实验的结果验证了所设计的控制器的有效性。     

Robust Flight Control Using Nonsmooth Optimization for a Tandem Ducted Fan Vehicle

This work addresses the aerodynamic modeling and near‐hover‐flight control design for an unconventional aerial robot of the tandem ducted fan configuration, which is intended to be prototypical of a flight service vehicle. The main model elements of this novel unmanned vehicle, which exhibit highly nonlinear and unstable open‐loop modes, are presented. A frequency‐domain controllability analysis concerning the plant's behavior around the hovering flight condition is then adopted to determine the expected control performance, which is of important practical significance to controllability improvement through vehicle design changes. A robust controller that stabilizes the unmanned vehicle under wind disturbances is designed using a newly developed nonsmooth optimization algorithm, which rigorously and efficiently tunes the arbitrarily predefined structured controller against multiple control requirements. A successive two‐loop architecture is employed in the designed controller. In this architecture, the inner loop provides stability augmentation and decoupling, and the outer loop guarantees the desired velocity tracking performance. Simulation results under stochastic wind gusts are presented to verify the performance of the proposed controllers. Preliminary flight tests are also carried out to demonstrate the performance of the system.     

Practical near hover flight control of a ducted fan (SLADe)

The development of a near hover flight control system for an electrically powered, coaxial, counter-rotating ducted fan aircraft (SLADe—surface launched aerial decoy) is presented. The control and estimation algorithms are designed to operate with low-cost sensors, be computationally efficient, robust and easily adaptable from flight test data. Successive loop closure is employed in the controller design with feedback signals from linear decoupled estimators. Simulation results verify the controller functionality and show that the decoupled estimators perform well near hover when compared to a coupled nonlinear 16 state Kalman filter. Flight test results are presented that verify the practical success of the autopilot.     

Nested PID steering control for lane keeping in autonomous vehicles

In this paper a nested PID steering control in vision based autonomous vehicles is designed and experimentally tested to perform path following in the case of roads with an uncertain curvature. The control input is the steering wheel angle: it is designed on the basis of the yaw rate, measured by a gyroscope, and the lateral offset, measured by the vision system as the distance between the road centerline and a virtual point at a fixed distance from the vehicle. No lateral acceleration and no lateral speed measurements are required. A PI active front steering control based on the yaw rate tracking error is used to improve the vehicle steering dynamics. The yaw rate reference is computed by an external control loop which is designed using a PID control with a double integral action based on the lateral offset to reject the disturbances on the curvature which increase linearly with respect to time. The proposed control scheme leads to a nested architecture with two independent control loops that allows us to design standard PID controls in a multivariable context (two outputs, one input). The robustness of the controlled system is theoretically investigated with respect to speed variations and uncertain vehicle physical parameters. Several simulations are carried out on a standard big sedan CarSim vehicle model to explore the robustness with respect to unmodelled effects. The simulations show reduced lateral offset and new stable μ-split braking maneuvres in comparison with the model predictive steering controller implemented by CarSim. Finally the proposed control law is successfully tested by experiments using a Peugeot 307 prototype vehicle on the test track in Satory, 20 km west of Paris.     

Robust Tracking Control of a Quadrotor Helicopter

In this paper, a robust tracking control method for automatic take-off, trajectory tracking, and landing of a quadrotor helicopter is presented. The designed controller includes two parts: a position controller and an attitude controller. The position controller is designed by the static feedback control method to track the desired trajectory of the altitude and produce the desired angles for pitch and roll angles. By combining the proportional-derivative (PD) control method and the robust compensating technique, the attitude controller is designed to track the desired pitch and roll angles and stabilize the yaw angle. It is proven that the attitude tracking error of each channel can converge to the given neighborhood of the origin ultimately. Experimental results demonstrate the effectiveness of the designed control method.     

Supervisory recurrent fuzzy neural network control of wing rock for slender delta wings

Wing rock is a highly nonlinear phenomenon in which an aircraft undergoes limit cycle roll oscillations at high angles of attack. In this paper, a supervisory recurrent fuzzy neural network control (SRFNNC) system is developed to control the wing rock system. This SRFNNC system is comprised of a recurrent fuzzy neural network (RFNN) controller and a supervisory controller. The RFNN controller is investigated to mimic an ideal controller and the supervisory controller is designed to compensate for the approximation error between the RFNN controller and the ideal controller. The RFNN is inherently a recurrent multilayered neural network for realizing fuzzy inference using dynamic fuzzy rules. Moreover, an on-line parameter training methodology, using the gradient descent method and the Lyapunov stability theorem, is proposed to increase the learning capability. Finally, a comparison between the sliding-mode control, the fuzzy sliding control and the proposed SRFNNC of a wing rock system is presented to illustrate the effectiveness of the SRFNNC system. Simulation results demonstrate that the proposed design method can achieve favorable control performance for the wing rock system without the knowledge of system dynamic functions.     

Integrated stability control of AFS and DYC for electric vehicle based on non-smooth control

A controller which ensures the driving stability of a four-wheel-independent-drive electric vehicle (4WID-EV) is designed in this paper. The controller is structurally hierarchically designed. In order to keep the 4WID-EV running steadily, an upper-level controller integrating the active front-wheel steering control method (AFS) and direct yaw moment control method (DYC) is designed to keep the sideslip angle and yaw rate tracking the ideal values. A non-smooth control method is used to improve the closed-loop system's convergence and anti-disturbance performance. The additional yaw moment generated by the upper-level controller is distributed to four driving wheels by the lower-level controller. An optimal control algorithm is used in the lower-level controller to achieve the minimum sum of tire utilisation, and ensure the power performance and driving stability of the 4WID-EV. In order to verify the effectiveness of the designed controller, a simulation model of the stability control system is established based on Carsim-Matlab/Simulink. And the simulation is performed under double lane change road considering the disturbances. The results of the simulation show that the 4WID-EV with the designed controller achieves smaller sideslip angle than sliding-mode control and the actuator chatter is slight. Then the stability and safety of the 4WID-EV are greatly improved.     

Stabilization and nonlinear control for a novel trirotor mini-aircraft

The dynamical model of an original trirotor helicopter is presented in this paper. The helicopter is composed of three rotors with constant pitch propellers; two fixed rotors turning in opposite directions and one rotor that can be tilted to control the yaw displacement. The dynamical model is obtained via the Euler–Lagrange approach and a nonlinear control strategy is proposed. The roll and the forward displacement are controlled by using a nested saturations control law. The pitch and lateral displacement are controlled in a similar way. The nonlinear controller performance is tested on real experiments using a trirotor rotorcraft. It is shown that the controller is robust to large perturbations on the orientation angles and that it has better behavior than a classical linear state-feedback controller.     

基于低通非奇异终端滑模引导的舰载机抗侧风着舰控制技术

针对舰载机的抗侧风着舰控制问题,设计一种低通非奇异终端滑模引导算法（LNTSMC）用于提高舰载机的抗侧风引导能力. 首先, 基于 H_∞混合灵敏度控制设计内环姿态鲁棒控制系统, 并推导舰载机着舰飞行时的侧向引导方程;然后,基于齐次性理论设计一种积分非奇异终端滑模面,使其在满足低通滑模控制器设计要求的同时避免控制奇异现象;进一步,设计一种带边界层的幂指数趋近律来抑制滑模控制中的抖振情况,并引入非齐次干扰观测器来改善边界层内部的鲁棒稳定性; 最后, 通过 Lyapunov 定理证明所设计算法的有限时间稳定性, 并给出仿真结果. 仿真结果表明,所设计的引导算法具有良好的抗侧风性能,通过与已有算法进行对比,验证了所提出算法的优越性.