Auto-landing of fixed wing unmanned aerial vehicles using the backstepping control

The control of the unmanned aerial vehicles is a difficult problem because of their light weight and the strong coupling between the longitudinal and lateral modes. Motivated by this, a backstepping and dynamic inversion-based automatic landing system is designed in this paper for the flight control of a fixed wing unmanned aerial vehicle subject to wind shears, atmospheric disturbances, and wind gusts. Two backstepping-based controllers are designed for the stabilization of the attitude angles, while the controller associated to the forward velocity uses the dynamic inversion technique to obtain a constant forward velocity during all the three stages of landing. To provide an estimation of the wind shears, atmospheric turbulences, and wind gusts, a nonlinear disturbance observer is introduced in the control architecture. The lateral deviation with respect to the runway is canceled while the unmanned aerial vehicle maintains its desired trajectory slope angle. The novel adaptive automatic landing system is software implemented and validated by complex numerical simulations; the results of the numerical simulations prove the stability and robustness of the new control architecture for different initial conditions and wind type disturbances.     

倾转旋翼机过渡段动态最优控制技术研究

针对倾转旋翼机的最优过渡问题，采用动态最优控制来减小过渡时间、姿态角变化以及缓解驾驶员工作负荷。在飞行动力学模型的基础上引入操纵方程，通过引入操纵量方程来缓解操纵量的跳变；随后将飞行器的最优动态倾转过渡过程转变成非线性动态最优控制问题，引入合理的性能指标，基于序列二次规划算法进行求解；最终以XV-15为例，分析系统各个通道抗风扰能力以及进行全航线飞行仿真。实验结果表明，所设计的过渡段最优控制在倾转旋翼机的各个通道抗风扰性能突出，系统鲁棒性较好，具有较好的实际应用价值。     

Attitude maneuver control of flexible spacecraft by observer-based tracking control

A constraint equation-based control law design for large angle attitude maneuvers of flexible spacecraft is addressed in this paper. The tip displacement of the flexible spacecraft model is prescribed in the form of a constraint equation. The controller design is attempted in the way that the constraint equation is satisfied throughout the maneuver. The constraint equation leads to a two-point boundary value problem which needs backward and forward solution techniques to satisfy terminal constraints. An observer-based tracking control law takes the constraint equation as the input to the dynamic observer. The observer state is used in conjunction with the state feedback control law to have the actual system follow the observer dynamics. The observer-based tracking control law eventually turns into a stabilized system with inherent nature of robustness and disturbance rejection in LQR type control laws.     

Extended observer based on adaptive second order sliding mode control for a fixed wing UAV

This paper addresses the design of attitude and airspeed controllers for a fixed wing unmanned aerial vehicle. An adaptive second order sliding mode control is proposed for improving performance under different operating conditions and is robust in presence of external disturbances. Moreover, this control does not require the knowledge of disturbance bounds and avoids overestimation of the control gains. Furthermore, in order to implement this controller, an extended observer is designed to estimate unmeasurable states as well as external disturbances. Additionally, sufficient conditions are given to guarantee the closed-loop stability of the observer based control. Finally, using a full 6 degree of freedom model, simulation results are obtained where the performance of the proposed method is compared against active disturbance rejection based on sliding mode control.     

三种方法在机翼振动主动控制中的仿真研究

针对某型机翼振动响应较大问题,研究了PID、LQR和LMS等3种控制律方法实现振动主动控制技术的可行性。在仿真试验中,采用Patran进行结构建模和压电力等效,通过Matlab的Simulink模块搭建控制仿真模型,使用设计出的试验方案进行。结果表明,通过优化参数,PID、LQR和LMS等3种控制律方法在仿真模拟中均较好地抑制了振动响应,在机翼上实现主动控制技术。LMS方法的控制效果更佳,PID方法的控制收敛时间更短。     

基于PID与LQR的两轮平衡小车控制算法的仿真研究

两轮平衡小车是一种非线性、强耦合、多变量的系统,是检验各种控制方法处理能力的典型装置。在ADAMS与MATLAB软件平台下,应用PID与LQR两种控制算法对两轮平衡小车的控制效果进行研究。研究表明:LQR的控制效果较好,适应性更好。     

看板透视化管理在智能工厂中的应用研究

为提高生产看板透视化管理的智能性,提出基于模糊PID的看板透视化智能控制技术。采用全局参数融合方法,对智能工厂中看板透视化管理的多模控制函数进行过程分析,并构建约束特征方程,计算约束特征方程下多模控制函数的约束参量,结合约束参量获取管控隐含层的输出值,实现看板透视化管理过程控制优化。仿真实验结果表明,采用该方法进行看板透视化管理和智能控制的稳定性较好,提高了看板透视化管理的智能化水平。     

一种双倾斜式全驱动六旋翼无人机的建模与控制

常规旋翼无人机大都采用共线设计,只能产生竖直方向的推力,极大地限制了旋翼无人机在涉及物理交互任务时的应 用。 针对此问题,研究了一种双倾斜式全驱动六旋翼无人机,采用旋翼转轴非共线的设计方法,可以实现位置与姿态的独立控 制。 提出了一种抑制抖振的改进型积分滑模控制器,并与 PID 控制器、积分反演控制器和传统积分滑模控制器进行对比。 仿真 结果表明,所提出的改进型积分滑模控制器能够实现旋翼无人机位置与姿态的独立控制,并能够有效克服自身模型参数的不确 定性以及外部的风场扰动完成定点悬停与复杂的轨迹跟踪。 实物样机实验结果表明,该设计的全驱动旋翼无人机在长距离横 向运动时能够保持水平姿态, 俯仰角和滚转角误差控制在±2°以内。     

基于LQR指标的直线伺服系统最优PID控制器设计

由音圈电动机驱动的直线伺服系统是实现非圆截面类零件数控车削加工的关键。基于二次型性能指标（LQR）设计了直线伺服系统的最优PID控制器。首先给出了直线伺服系统的双闭环PID控制结构，其次研究了基于二次型性能指标的数字PID参数最优整定方法。最后通过仿真实验验证了该控制方法的有效性。     

环形供热管网水力工况设计方法研究

为提高环形供热管网水力工况运行稳定性,提出了基于模糊PID控制的环形供热管网水力工况控制方法。构建环形供热管网水力工况控制的约束参量模型,在此基础上采用回归模型逼近方法构建其测试指标集,结合自适应融合反馈跟踪方法进行环形供热管网水力工况信息的融合处理,并从中提取分布特征量;采用模糊PID控制方法调节提取结果的输出稳定性,实现环形供热管网水力工况优化设计和自适应控制。仿真结果表明,采用该方法进行环形供热管网水力工况控制的稳定性较好,自适应控制能力较强,实现了环形供热管网水力工况优化调节。     

基于单纯形法的最优PID控制器设计

以偏差积分性能指标ITAE为目标函数,采用单纯形法整定PID控制参数,进而获得最优PID控制器,以实现系统最优控制.仿真结果表明,寻优后系统具有良好的跟随性能和抗扰性能.     

一类非自衡对象的最优PID控制

实际控制系统中输入控制对象的控制能量大小不可能是无限大的,本文对控制能量存在约束时一类非自衡对象的最优控制问题作了探讨.首先定义了一个包含跟踪误差和控制能量在内的积分平方性能指标,然后针对不同设计要求运用最优方法极小化该性能指标,从而导出2类PID控制器的解析设计方法,可使系统在控制能量约束条件下具有最优的控制性能.     

倒立摆控制方法的比较研究

倒立摆系统作为典型的控制对象,不仅对控制设计提出了难题,同时为很多先进控制方法的研究和应用提供了一个很好的实验平台。该文分别用PID控制法、优化控制策略的LQR及极点配置法等3种方法对单级倒立摆系统进行控制,并利用MATLAB仿真对3种控制算法的效果进行了对比,讨论了3种方法之间的优缺点。仿真实验表明:PID法与极点配置法具有较好的瞬态性,LQR法具有较好的鲁棒性。在实际应用中,可根据控制系统的具体指标要求选择适合的控制方法,具有一定的指导意义。     

磁轴承飞轮控制系统设计中LQR方法的应用研究

对于具有强的陀螺效应的磁悬浮飞轮转子,将转子各自由度作为独立个体采用分散控制难以满足系统要求,而LQR方法不失为一种有效的集中控制方法。通过对LQR控制方法在飞轮转子上的仿真研究,给出了LQR方法应用于磁悬浮系统控制时,加权阵Q阵与R阵的选取原则,并对反馈阵F中各参数的物理本质进行了阐述。由仿真结果与理论推导相结合,论证了陀螺位移交叉反馈的作用,由此给出了LQR控制的一种简化实现方法。     

Tuning of linear active disturbance rejection controller with robustness specification

Active disturbance rejection control (ADRC) treats all the model uncertainties and all the external disturbances as a generalized disturbance. It uses an extended state observer (ESO) to estimate the generalized disturbance in real time, and compensate it using a state-feedback control law, thus can achieve good disturbance rejection performance. For linear ADRC (LADRC), the parameters can be tuned via the bandwidths of the ESO and the feedback control, thus an LADRC can be regarded as a fixed-structured controller with several parameters to tune, just like a PID controller. To help tuning the parameters of LADRC, a tuning rule is proposed in this paper, with the aim to minimize the load disturbance attenuation performance in the integral of time square error sense, under the constraint of a specified robustness measure for the first-order processes with deadtime. The tuning rule is tested for a variety of benchmark systems and the gravity drained tanks case, and the performances are compared with the well-known PID tuning methods.     

一种基于粒子群算法的二自由度PID控制器优化设计

粒子群算法在解决复杂问题的优化设计上具有算法简单,计算速度快的优点,将粒子群算法引入到二自由度PID控制器的参数整定中,用于改进二自由度PID控制器参数整定的效率并进行了仿真实验,仿真结果表明,系统同时具有了最优的目标值跟踪特性和干扰抑制特性.     

Dynamically adapt to uneven terrain walking control for humanoid robot

Dynamically adapt to uneven ground locomotion is a crucial ability for humanoid robots utilized in human environments.However,because of the effect of current pattern generation method,adapting to unkn...     

周期性扰动下卷绕基板的横向位移控制

柔性基板的横向位移控制是卷到卷（roll-to-roll）系统中的关键技术之一,横向偏移会导致定位误差、收卷不齐,直接影响成品的质量。针对卷绕过程中辊筒的旋转偏心造成的基板横向位置上的周期性干扰,提出将插入式重复控制器应用于柔性基板的横向位移控制。该方法不需要改变原有控制器的结构,只需在其之前增加一个重复控制器环节,即能实现对任意周期信号或干扰的高精度跟踪或抑制。仿真实验结果表明,插入式重复控制算法相比单纯PID控制能显著提高系统对辊筒偏心引起的横向周期性干扰的抑制能力,提高系统的稳态精度,具有良好的鲁棒性。     

时变大时滞神经元自适应预测PID控制器

本文提出一种克服时变大时滞,扰主被控制过程参数时变的神经自适应预测ＰＩＤ控制算法。该算法利用预测控制克服时滞,利用智能方法优化ＰＩＤ控制器的参数。     

Long-term stabilization of the optical fiber phase control using dual PID

We propose an approach of long-term stabilization of optical fiber phase by controlling a piezo-based phase modulator and a Peltier component attached to the fiber via a phase-locked loop( PLL) circuit w ith dual proportional-integral- derivative( PID) adjustment. With this approach,we can suppress the fast disturbance and slow drifting of optical fiber to satisfy the requirements of optical phase long-term locking. In theory,a mathematical model of an optical fiber phase control system is established. The disturbance term induced by environment influence is considered into the PLL model. The monotonous and continuous changing environment disturbance w ill cause a steady-state error in this theory model. The experimental results accords w ell w ith the theory. The steady-state performance,adjusting time,and overshoot can be improved by using the dual PID control. As a result,the long-term,highly stable and low noise fiber phase locking is realized experimentally.