Anti-Disturbance Control for Tethered Aircraft System With Deferred Output Constraints

In this paper,we investigate the peaking issue of extended state observers and the anti-disturbance control problem of tethered aircraft systems subject to the unstable flight of the main aircraft,airflow disturbances and deferred output constraints.Independent of exact initial values,a modified extended state observer is constructed from a shifting function such that not only the peaking issue inherently in the observer is circumvented completely but also the accurate estimation of the lumped disturbance is guaranteed.Meanwhile,to deal with deferred output constraints,an improved output constrained controller is employed by integrating the shifting function into the barrier Lyapunov function.Then,by combining the modified observer and the improved controller,an anti-disturbance control scheme is presented,which ensures that the outputs with any bounded initial conditions satisfy the constraints after a pre-specified finite time,and the tethered aircraft tracks the desired trajectory accurately.Finally,both a theoretical proof and simulation results verify the effectiveness of the proposed control scheme.

Design of No-Steady-Error and Anti-Disturbance Controller for Vehicular Servo Systems

A modified method of design of no-steady-error and anti-disturbance controller is proposed for the design of tank stabilizers. Using a reduced-order observer to estimate its mode, disturbance can be compensated. This enables the system to resist sinusoidal disturbance with any magnitude. Estimate of angular velocity is used as the state feedback to replace the expensive gyro and tachometer generator. The modified method excels the traditional, and provides a new way for the design of tank fire control system. It can also be applied for the design of other servo systems in vehicle and aircraft.

Research on the anti-disturbance issues of the breakout prediction system in continuous casting

This paper introduces the function, structure and alarm principles of the breakout prediction system installed for continuous casting in Baosteel＇ s No. 2 Steelmaking Plant. It elaborates on four parameters in the alarm logic,including the temperature changing rate, temperature difference, temperature fluctuation and temperature match of thermocouples. This paper also explains the causes of different disturbances within the breakout prediction system, and the methods used to prevent and eliminate disturbances from radiation, earth, crosstalk, temperature drift and time drift. Finally, the paper summarizes some potential applications of the above technology.

Study on Anti-Disturbance and High-Resolution Shallow Seismic Exploration of Active Faults in Urban Regions

The significance of detection of urban active faults and the general situation concerning detection of urban active faults in the world are briefly introduced. In a brief description of the basic principles of anti-disturbance and high-resolution shallow seismic exploration, the stress is put on the excitation of seismic sources, the performance of digital seismographs, receiving mode and conditions, geometry as well as data acquisition, processing and interpretation in the anti-disturbance and high-resolution shallow seismic exploration of urban active faults. The study indicates that a controlled seismic source with a linear or nonlinear frequency-conversion scanning function and the relevant seismographs must be used in data acquisition, as well as working methods for small group interval, small offset, multi-channel receiving, short-array and high-frequency detectors for receiving are used. Attention should be paid to the application of techniques for static correction of refraction, noise suppressing, high-precision analysis of velocity, wavelet compressing, zero-phasing of wavelet and pre-stacking migration to data processing and interpretation. Finally, some cases of anti-disturbance and high-resolution shallow seismic exploration of urban active faults are present in the paper.

Adaptive composite anti-disturbance control for heavy haul trains

In this paper,an adaptive composite anti-disturbance control of heavy haul trains(HHTs)is proposed.First,the mechanical principle and characteristics of couplers are analysed and the longitudinal multi-particles nonlinear dynamic model of HHTs is established,which can satisfy that the forces of vehicles in different positions are different.Subsequently,a radial basis function network(RBFNN)is employed to approximate the uncertainties of HHTs,and a nonlinear disturbance observer(NDO)is constructed to estimate the approximation error and external disturbances.To indicate and improve the approximation accuracy,a serial-parallel identification model of HHTs is constructed to generate a prediction error,and an adaptive composite anti-disturbance control scheme is developed,where the prediction error and tracking error are employed to update RBFNN weights and an auxiliary variable of NDO.Finally,the feasibility and effectiveness of the proposed control scheme are demonstrated through the Lyapunov theory and simulation experiments.

基于等价输入干扰滑模观测器的磁悬浮轴承控制

针对磁悬浮轴承受到未知干扰而使转子偏离理想位置导致控制性能下降的问题,建立了存在未知干扰的磁悬浮轴承模型,基于模型设计了等价输入干扰系统,利用积分滑模观测器对系统状态量进行观测并结合等价输入干扰估计器协同实现对未知干扰的实时精准估计,通过控制端对等价输入干扰估计值进行前馈补偿,设计转子位置环的滑模控制器,通过复合控制提高系统的鲁棒性。与其他方法的仿真对比结果表明,所提方法能够提高轴承系统的抗扰性能,实现对转子位置的高精度控制。

带宽化调节下的抗扰PID退饱和控制方法

比例–积分–微分(PID)控制的抗饱和设计是一类经典非线性控制问题,理论研究丰富,但工程中广泛使用的仍是积分退饱和这类简易策略.究其原因,现有理论方法过于依赖系统模型和状态空间理论,稳定性条件与调参机制之间关系复杂.本文基于经典退饱和控制结构,首次阐述了“退饱和带宽”概念及退饱和参数调节机理,在此基础上讨论了两类低阶退饱和补偿器的带宽化设计方法.在抗扰PID反馈控制下,结合小增益定理得到退饱和控制的稳定性条件,给出控制参数与退饱和带宽之间的调节关系,实现退饱和控制的带宽化整定.最后,通过数值仿真验证了所提方法的有效性.

Disturbances rejection optimization based on improved two-degree-of-freedom LADRC for permanent magnet synchronous motor systems

Permanent magnet synchronous motor(PMSM)speed control systems with conventional linear active disturbance rejection control(CLADRC)strategy encounter issues regarding the coupling between dynamic response and disturbance suppression and have poor performance in suppressing complex nonlinear disturbances.In order to address these issues,this paper proposes an improved two-degree-of-freedom LADRC(TDOF-LADRC)strategy,which can enhance the disturbance rejection performance of the system while decoupling entirely the system's dynamic and anti-disturbance performance to boost the system robustness and simplify controller parameter tuning.PMSM models that consider total disturbances are developed to design the TDOF-LADRC speed controller accurately.Moreover,to evaluate the control performance of the TDOF-LADRC strategy,its stability is proven,and the influence of each controller parameter on the system control performance is analyzed.Based on it,a comparison is made between the disturbance observation ability and anti-disturbance performance of TDOF-LADRC and CLADRC to prove the superiority of TDOF-LADRC in rejecting disturbances.Finally,experiments are performed on a 750 W PMSM experimental platform,and the results demonstrate that the proposed TDOF-LADRC exhibits the properties of two degrees of freedom and improves the disturbance rejection performance of the PMSM system.

汽车电子机械制动系统的ABS自抗扰控制

为解决传统车辆液压制动系统响应滞后、ABS存在滑移率非线性等问题,设计了一种“行星齿轮减速机构+滚珠丝杠+活塞”的电子机械制动执行器方案,提出一种基于滑移率的ABS自抗扰控制策略,使电子机械制动系统能够快速、准确地调节各个车轮的制动力,有效满足ABS的要求。运用Matlab/Simulink验证执行器的响应性能,分别在2种路面工况下进行ABS制动过程的仿真。研究结果表明:自抗扰控制对于系统内外部扰动具有较强的鲁棒性,能保证车辆的前、后轮滑移率更快稳定在目标滑移率处,有效减少了车辆的制动时间与制动距离。

柔性关节航空航天机械臂抗干扰控制研究

航空航天机械臂具有柔性且对精度要求高,为抑制空间环境力矩和内部参数变化等干扰,提出了一种基于干扰观测器的航空航天机械臂反步控制策略。首先,建立柔性关节航空航天机械臂受干扰时的单关节数学模型,基于数学模型设计柔性关节航空航天机械臂的非线性干扰观测器,保证其能稳定估计干扰信号;然后,基于Lyapunov函数设计反步控制器,将干扰观测器估计到的干扰估计值补偿到反步控制器端,产生抑制实际干扰的控制量;最后,利用MATLAB/simulink搭建虚拟仿真进行验证。仿真结果表明,基于干扰观测器的柔性关节航空航天机械臂反步控制器能够有效抑制干扰,极大地改善了柔性关节航空航天机械臂的抗干扰性能。

低载波比下基于状态反馈和大林算法的永磁同步电机高性能电流控制策略

受到功率器件开关频率的限制,高速永磁同步电机驱动系统通常需要低载波比运行,此时系统延时相对很大,对电流环设计要求很高。常规在连续域设计的复矢量PI控制器由于离散化实现存在误差,dq轴解耦不完全,而且扰动传递函数包含电机自身低阻尼比极点,使系统抗干扰能力差,尤其是负基波频率附近的扰动。因此,文中提出状态反馈大林控制算法。首先,利用延时环节电压进行反馈来使系统完全解耦;然后,通过输出电流反馈提升系统阻尼来抑制扰动;最后,对解耦且阻尼后的系统设计大林控制器来提升稳定裕度。实验结果表明,相较于复矢量PI控制器,所提出的状态反馈大林控制器dq轴解耦性能好,电流超调小,系统振荡小,且抗扰能力显著提升。

基于改进纯跟踪的低速智能汽车路径跟踪控制

传统纯跟踪控制器在面向实际应用时往往难以较好地处理传感器信号延时、执行器响应滞后等因素带来的控制滞后问题以及欠缺内外部扰动干预下的自主抗干扰能力;同时在跟踪临近终点的目标点时,因前视距离作为控制律的分母且逐渐减小,导致输入转角值发生突变且伴随方向盘出现不稳定地晃动现象,影响行驶稳定性及人员乘坐体验感。针对此,提出了一种基于改进纯跟踪的路径跟踪控制器。首先,构建了纯跟踪控制器的基础模型并为改善纯跟踪控制的滞后影响,建立了一种结合规划路径和规划速度信息的道路预瞄模型。然后考虑系统因内部及外部环境影响产生的未知干扰并设计非线性扩张状态观测器(nonlinear expanded state observer,NESO)进行扰动估计及实时补偿,以提升纯跟踪控制器的抗干扰能力。并进一步通过转向稳定调节模型以改善纯跟踪控制器临近终点时的转角突变问题。最终,基于软件在环动力学仿真平台以不同初始航向及存在初始偏差工况下测试所提控制器的有效性,并进一步在实车平台进行闭环测试验证,实验结果表明改进的纯跟踪算法具有良好的跟踪精度和转向平顺性。

船舶永磁同步电机在线惯量辨识研究

针对船舶永磁同步电机推进系统的转动惯量和负载转矩存在扰动的问题,提出基于梯度校正法与扩展卡尔曼滤波器结合的在线惯量辨识算法,采用梯度校正法对转动惯量进行辨识,利用扩展卡尔曼滤波器观测负载转矩,辨识的惯量值对滤波器的系数矩阵进行修正,同时观测的负载转矩作为梯度校正法的输入参数以及作为电流环的前馈补偿。仿真和实验验证了惯量辨识算法的可行性,以及系统对于负载转矩变化的抗扰动性能。

高超声速飞行器发汗冷却系统自抗扰控制研究

针对高超声速飞行器发汗冷却系统的温度控制问题,在一维固定边界发汗冷却模型的基础上,提出了用于调节飞行器壁面多孔介质温度的自抗扰控制器,并进行了数值仿真。该控制器不依赖于多孔介质温度场精确的数学模型,通过从系统的输入输出数据中提取干扰信息并进行补偿,实现对热流干扰的抑制。仿真结果表明,针对发汗冷却系统设计的自抗扰控制器,能够实现对参考温度的快速跟踪;且相较于传统的PID控制,温度响应没有超调;在有外界热流干扰时,具有较强的鲁棒性和适应性,可以为发汗冷却控制系统的工程应用提供一定参考。

Anti-disturbance attitude control of combined spacecraft with enhanced control allocation scheme

In this paper, we propose a novel anti-disturbance attitude control law for combined spacecraft with an improved closed-loop control allocation scheme. More specifically, a saturated approach is adopted to guarantee the global asymptotic stability under control input saturation.To enhance the robustness of the system, a nonlinear disturbance observer is constructed to compensate the disturbances caused by inertial parameter uncertainty and unmodeled dynamics. Next,the quadratic programming algorithm is used to obtain an optimal open-loop control allocation scheme, where both energy consumption and actuator saturation have been considered in the allocation of the virtual control command. Then, a modified closed-loop control allocation scheme is proposed to reduce the allocation error under the actuator uncertainty. Finally, stability analysis of the closed-loop system with the proposed allocation scheme is provided. Simulation results confirm the effectiveness of the proposed control scheme.

基于级联线性-非线性自抗扰控制器的永磁直线同步电机速度控制策略研究

为了提升永磁直线同步电机(permanent magnet linear synchronous motor,PMLSM)在负载变化、参数摄动和其他不确定因素下的抗扰性能和速度跟踪性能,提出一种基于级联线性-非线性自抗扰控制器的PMLSM速度控制策略。首先,建立考虑负载扰动和参数失配的PMLSM数学模型;其次,设计级联线性-非线性扩张状态观测器来实时估计和补偿系统所受的不确定扰动,前级线性扩张状态观测器保证系统在大扰动下保持稳定,后级非线性扩张状态观测器利用非线性机制进一步提高系统对扰动的估计精度,从而将线性自抗扰控制和非线性自抗扰控制的优势相结合,以此提升系统的速度跟踪性能和抗扰动能力;并且,对所提控制器提出基于劳斯判据的稳定性分析方法,并对系统的抗扰性能和噪声抑制性能进行了频域分析;最后,对基于PI控制、级联线性自抗扰控制、非线性自抗扰控制和级联线性-非线性自抗扰控制的永磁直线同步电机系统进行仿真和实验对比,验证所提方法的优越性。

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.

具有执行器饱和的不确定系统的干扰抑制控制

针对传统的干扰观测器(DO)设计并未考虑实际系统中普遍存在的执行器饱和问题,提出了一种具有抗饱和补偿的基于干扰观测器的控制(DOBC)策略.首先探究传统DOBC在执行器饱和时产生积分饱和现象的原因;然后通过最小化性能指标设计了一种抗积分饱和的补偿器,并将其与DO结合,使得修改后的DOBC能够有效处理执行器饱和;最后对所得闭环系统进行局部渐近稳定性分析.比较仿真结果表明,存在执行器饱和时,所提出控制方法具有更小的位置跟踪误差和干扰估计误差,并且设计的补偿器可以保持DO的状态尽可能接近没有执行器饱和时的状态,进而验证了所提出控制方法在抗干扰和抗饱和方面具有优越性.

电气化铁路“车-网”系统串/并联双模式宽频谐波扰动产生装置设计与测量方法

精确测量动车组与电力机车(简称机车)四象限变流器(four-quadrant converter,4QC)和牵引网的宽频带阻抗特性是识别电气化铁路“车-网”系统振荡和不稳定问题的重要途径。然而,已有研究采用单一电压/电流扰动注入方式对牵引网或机车4QC阻抗进行测量,可能造成部分谐波扰动流向非目标测量对象,导致被测对象的谐波扰动信噪比低,影响阻抗测量精度。因此,该文提出一种适用于电气化铁路“车-网”联合系统的串/并联双模式宽频谐波扰动产生装置与阻抗测量方法,装置具有电压和电流两种工作模式,可以发出频带为1~3000Hz的宽频谐波扰动。扰动产生装置拓扑主要由多绕组降压变压器、谐波功率放大单元、并联LC谐振电路和反串联绝缘栅双极晶体管(insulated gate bipolar transistor,IGBT)模块等部分构成,结合双闭环dq解耦控制和载波移相开环脉宽调制(pulse-width modulation,PWM)控制策略,实现频带双边可控、幅值可控且分布均匀的大功率谐波扰动输出。最后,利用MATLAB/Simulink仿真和RT-Lab硬件在环实验验证该文串/并联双模式宽频谐波扰动产生装置设计方案及阻抗测量方法的正确性与有效性。

基于自适应分层滑模的塔式起重机防摆与定位控制

针对三维空间中呈现二级摆结构的塔式起重机的防摆与定位控制问题,考虑变幅回转联合运行工况,提出了一种自适应分层滑模控制方案。首先将塔式起重机系统分为定位子系统、一级摆角子系统和二级摆角子系统,设计了分层滑模控制律;然后设计了自适应律,提高了系统对参数的适应性和对外在干扰的抑制性能;最后验证了系统的稳定性并对系统进行了仿真。仿真结果表明,系统在受到瞬时扰动时,自适应律可估算出扰动大小,控制器能快速做出反应,调整控制力/力矩以抵消瞬时扰动,使瞬时扰动不对系统的位置以及吊钩和负载的摆角造成明显影响。该文自适应分层滑模控制器能在一定程度上抑制瞬时扰动造成的吊钩和负载的摆动,具有较好的鲁棒性。