Gearshift control system development for direct-drive automated manual transmission based on a novel electromagnetic actuator

A novel gearshift system which comprises a 2 degree-of-freedom electromagnetic actuator is introduced to simplify the structure of gearshift system of automated manual transmission (AMT), increase transmission efficiency and improve shift quality. The working principle and characteristics of the actuator are analyzed. The gearshift process is divided into the non-synchronization and the synchronization phase. Extended state observer (ESO) based inverse system method (ISM) and active disturbance rejection controller (ADRC) are designed for the two processes respectively. ISM can eliminate the nonlinearity of the actuator and ESO can estimate and compensate the uncertainties, parameter variations and external disturbances. ADRC is adopted to improve the tracking accuracy of the synchronization process. Comparative simulations and experimental results demonstrate the effectiveness of the proposed control method, and good gearshift performance has been achieved. Combined with the new designed control strategy, the novel gearshift system provides a new solution for AMT applications.     

Self-balancing based on Active Disturbance Rejection Controller for the Two-In-Wheeled Electric Vehicle,Experimental results

This article deals with a robust self-balancing control scheme for the Two-In-Wheeled Self-Balancing Electric-Vehicle (TIW-SB-EV). Due to time-varying and unknown torque load, uncertainties on system parameters, and the lack of knowledge of the friction components, the approach proposes the design and implementation of an active disturbance rejection control based on the extended state observer (ESO). The ESO is developed through the differentially Flatness property of the system. The system flat output measurement is obtained employing an absolute optical inclinometer, which represents the sole measurement of the plant. The electric traction for the TIW-SB-EV is composed of two In-wheel brushless DC motors (SG/F10-48 V, 800 W) powered by a controlled three-phase inverter. The TIW-SB-EV primary power source is supplied by two Lithium-Ion batteries (48 V, 10 AH). The proposed ADRC algorithm is coded on the TMS320F28335 Experimenter Kit, a device of the TMS320C28x/Delfino family. Real-time experimental results validate the mechanical design, electric drive, and control design and highlight the closed-loop robustness when the TIW-SB-EV is subjected to the endogenous and exogenous disturbances present in a real environment.     

线性扩张状态观测器的改进及在空间光通信粗跟踪的应用

针对传统自抗扰控制器的扰动补偿效果随着扰动频率增加迅速下降的问题,提出了一种基于改进的线性扩张状态观测器的自抗扰控制方法。该方法首先对粗跟踪进行系统分析、简化及辨识;然后对线性扩张状态观测器的观测原理进行详细推导与论证,从理论上指出其不足,提出了一种改进的线性扩张状态观测器;最后将改进的算法与PID调节器相结合,实现了粗跟踪的自抗扰控制。实验结果表明:针对幅度在1、频率在0.5~2.5 Hz间的外部位置扰动,传统的自抗扰控制器随着扰动频率的增加,扰动隔离度下降非常明显,2 Hz时的提升程度仅为0.5 Hz处的9.5%;而采用改进的算法使扰动隔离度至少提高了4.146 dB,且随着扰动频率的增加,扰动隔离度的提升非常稳定,2.5 Hz时的提升程度与0.5 Hz处几乎一致;此外,该方法有较好的鲁棒性,允许被控对象在20%的范围内变化。理论分析、仿真分析、物理实验均证明该方法的有效性,对类似的光电跟踪系统有一定的参考价值。     

永磁同步电机伺服系统控制中的自抗扰控制策略

本文以高精度伺服系统中的永磁同步电机变速扫描为研究对象,针对自抗扰控制器中跟踪微分器(trace differentiator,TD)及扩张状态观测器(expansion state observer,ESO)模块的延时响应和参数复杂等缺点,设计了一种改进的自抗扰控制器,有效简化了其TD和ESO模块并减少可调参数,以实现内外干扰较大的环境下电机的高精度快速响应。将该控制器应用到某型号项目的伺服摆扫镜机构中,并将其性能与同条件下传统比例-积分-微分(proportion-integration-differential,PID)控制器性能作对比。实验结果表明:改进的自抗扰控制器表现出优于PID的控制性能,0°/s^10°/s响应时间75 ms,超调小于6%,稳态精度达到±1%;变速跟踪过程转速波动小,无超调,扫描周期时间波动小于0.0014 s,起始位置角度定位精度高于0.0015°,满足型号项目指标要求。改进的自抗扰控制器对其他搭载永磁同步电机实现变速跟踪扫描的系统也有一定的参考价值。     

基于自抗扰控制的光电平台视轴稳定技术研究

针对影响光电平台控制精度的载体速度扰动以及测量噪声等因素,设计了扰动自抗扰以及滤波控制的两部分控制策略。首先,通过分析光电平台伺服系统速度稳定环的数学模型中扰动作用原理,等效各个扰动作用并提出扰动总和思想,设计了基于降阶扩张状态观测器的自抗扰控制器。其次,利用卡尔曼滤波器对系统中测量噪声进行了滤波处理,降低了扩张状态观测器的估计误差。最后,详细地进行了传统PI控制系统与文中设计的卡尔曼自抗扰控制系统的对比实验。实验结果表明,在设计带宽相同的情况下,卡尔曼自抗扰控制系统相比PI控制系统的阶跃响应稳定时间减小32.53%,超调幅值减小72.73%;当使用摇摆台引入幅值为1频率、在2.5 Hz以内的正弦扰动时,卡尔曼自抗扰控制系统较PI控制系统的扰动隔离度提升了54.67%以上;在系统模型参数改变15%范围内,卡尔曼自抗扰控制系统仍具有优异的扰动隔离性能,表现出较强鲁棒性,满足光电平台视轴稳定的性能要求,对提升视轴稳定精度有较高实用价值。     

精确模型辨识的光电平台自抗扰控制器

针对实际工程中的复杂光电平台对控制精度要求越来越高的需求,提出一种依据系统精确模型辨识方法的自抗扰控制器设计方法。考虑机械谐振和摩擦因素,建立光电载荷控制系统精确数学模型,并根据系统输入输出特性辨识系统的数学模型参数,在所辨识模型的基础上设计自抗扰控制器。以某型光电跟踪平台为例,设计了4阶跟踪微分器,5阶扩张状态观测器和非线性状态偏差反馈控制律组合的自抗扰控制器。在Matlab/simulink中建立系统仿真平台,对PID控制器和自抗扰控制器进行仿真对比,结果表明,采用自抗扰控制器的系统超调由1.8%减小到0.9%,系统最大跟踪误差由0.03（）/s减小到0.013（）/s,超调更小,响应时间更快,抗扰动能力更强。     

自适应串级自抗扰弹性飞翼无人机姿态控制

文中针对飞翼无人机因其宽泛的飞行包线和特殊的布局带来的飞行控制技术难点,给出了一种自适应串级自抗扰飞翼无人机宽包线控制算法。首先,推导了适用于该算法的弹性飞翼无人机的非线性数学模型;其次,分别设计了弹性飞翼无人机的内环和外环自抗扰姿态控制器。自适应自抗扰控制器利用扩张状态观测器进行估计并动态反馈补偿,再利用NLSEF 抑制补偿残差;不需要无人机精确的模型参数,也无需精确的气动参数及摄动界限。仿真分析显示所设计的自适应自抗扰控制器较好地解决了弹性飞翼无人机从低空低速到高空高速的鲁棒控制,能够克服干扰及气动模态参数大范围摄动的影响。     

Nonlinear tracking control based on extended state observer for vehicle active suspensions with performance constraints

In this paper, a nonlinear tracking control strategy with extended state observer (ESO) is presented for vehicle active suspensions to improve the ride comfort, where suspension spaces, dynamic tire loads are considered as time-domain constraints to be guaranteed. The unique characteristic of the proposed approach lies in the independence on accurate mathematical model. More exactly, the unknown dynamics and external disturbances of the vehicle suspension are regarded as an augmented state of the system and are estimated using the designed ESO. The stability analysis shows that both the estimation error and the tracking error of the control output are bounded and that the upper bounds of the errors monotonously decrease with the increase of the observer bandwidth. Finally, a competitive experiment on a quarter-car suspension prototype is given to demonstrate the effectiveness of the proposed control schemes.     

航空光电稳定平台的二级自抗扰控制器

为了进一步提高两轴四框架航空光电稳定平台的抗 干扰能力,提出了一种二级自抗扰控制器(ADRC)的新方法。首先,在外框架中加入高精度陀 螺仪,使其具备扰动抑制能力;然后分别在内外框架中,采用带宽单参数化的设计方法设计 ESO及带扰动补偿的二级自抗扰控制规律;最后,在飞行模拟转台中测试(ADRC)对2.5Hz以内任意频率扰动的抑制能力。实验结果表明,对比于传统的平方滞后 超前控制器,采用二级ADRC,系统的扰动隔离度至少提高9.65dB, 且随着扰动频率大于0.5Hz,扰动隔离度的提高更为明显,最优情况 已达到16.08dB;同时,二级ADRC具有很强的鲁 棒性,允许被控对象参数在17%的范围内浮动,满足了高精度航空光 电稳定平台的性能要求,对提高航空光电稳定平台控制系统的抗扰动性能具有较高的实用价 值。     

基于自抗扰控制器的异步电机变频调速系统设计

针对传统PLC变频调速系统存在抗干扰能力弱、自适应能力差的问题,文章提出了一种基于自抗扰控制器(ADRC)的异步电机变频调速系统。此系统的核心思想是通过扩张状态观测器对系统进行扰动和补偿。从而达到控制对象可以近似线性化和确定性化的目的。测试结果表明,和传统的PLD控制方式相比,其跟随性、鲁棒性、抗干扰性和动态性能都很好,具有很好的实用价值。     

Data-driven iterative tuning based active disturbance rejection control for piezoelectric nano-positioners

The nano scale motions of piezoelectric actuated nano-positioning systems are very sensitive to operating tasks, external disturbances, as well as variations of system dynamics. In this paper, a data-driven Iterative Feedback Tuning (IFT) based Active Disturbance Rejection Control (ADRC) approach is developed to optimize the control performance by conducting controller parameter tuning iteratively from experimental test data. In particular, a parameterized input-output form of the linear ADRC controller is derived for the nano-positioner, where the IFT algorithm is applied to solve the established optimization problem to get the optimal control parameters. The proposed method is verified in simulations where the selection of control criterion and the impact of update step-size are also discussed. Single-axis and dual-axes real-time experiments are finally conducted on an X-Y piezoelectric actuated nano-positioner, which demonstrate significant performance improvement on nano-positioning and tracking over the conventional ADRC method.     

航空光电稳定平台扰动频率自适应的自抗扰控制

为了进一步提高光电稳定侦查平台的抗干扰能力,文中提出一种基于扰动频率自适应的自抗扰控制新方法。首先,基于带宽单参数化的设计方法,设计了扰动频率自适应的扩张状态观测器,从而解决了传统扩张状态观测器对二阶及二阶以上系统扰动观测存在明显相位滞后的影响;然后,设计了带扰动补偿的控制规律;最后,在模拟飞行器中以2.5 Hz 以内任意频率扰动的作用下,测试其抗扰动的性能。实验结果表明:对比于传统的平方滞后超前控制器,采用于扰动频率自适应的自抗扰控制器,系统的扰动隔离度至少提高6.72 dB,且随着扰动频率大于0.5 Hz,扰动隔离度的提高更为明显,最优情况已达到12.94 dB;同时,该控制器具有很强的鲁棒性,允许被控对象参数在10%的范围内浮动,满足高精度光电稳定平台的性能要求,具有较高的实用价值。     

半捷联导引头混合自抗扰控制系统设计

为了使半捷联导引头在干扰力矩和刻度尺误差引起的耦合干扰及其他不确定干扰下仍具有很强的鲁棒性,提出了伺服系统混合自抗扰控制（Active Disturbance Rejection Control,ADRC）方案。首先,建立了导引头半捷联稳定平台数学模型;其次,设计了半捷联导引头稳定平台混合自抗扰控制系统,通过对自抗扰稳定回路频带特性进行研究,分析了控制器参数对控制性能的影响,给出了控制参数设计原则;最后,对混合自抗扰控制方案进行了数字仿真验证。仿真结果表明:相比于传统控制器,混合自抗扰控制器能获得更好的控制精度,能有效克服干扰力矩和刻度尺误差对导引头的影响,在典型弹体频率2 Hz处隔离度幅值比传统控制器最多能降低约67.9%。研究成结果可为半捷联导引头稳定控制系统的设计提供指导。     

Active disturbance rejection control for robotic systems: A review

Over the past few decades, robotics technology and applications have attracted considerable interest from many researchers both in academia and industry. This interest mainly covers the development and implementation of control strategies for robotic systems such as adaptive control, robust control, active disturbance rejection control (ADRC), etc. The continuous complexity of physical systems that are being controlled necessitates some practical considerations for the controller design, analysis and implementation. In recent years, the ADRC approach has become a popular control framework adopted in robotic applications due to many advantages such as its simplicity of implementation as well as its robustness and ability to reject varying uncertainties and disturbances. This review paper provides a comprehensive assessment and insights into various ADRC frameworks developed for robotic systems and highlights the basic problems involved in this field. By a thorough review of existing ADRC schemes for robotic systems, recent results of these strategies that have broad implications are classified and analyzed in terms of their structural features and computational complexity. Moreover, we attempt in this review paper to provide a reference source in this area to help researchers and practitioners select a suitable ADRC structure for solving robotic application problems as well as to light up unsolved problems in the field. An example that illustrates the practical application of the linear and nonlinear ADRC to the 4-DOF robotic arm is presented in this review paper.     

Gas supply control and experimental validation for polymer electrolyte membrane fuel cells

Gas supply system control, which consists of air and hydrogen supply control, are two basic and crucial topics for proton exchange membrane fuel cell (PEMFC) control. To protect the PEM and improve the performance of the PEMFCs, the air pressure and flow of the cathode, and the hydrogen pressure of the anode should be precisely controlled. In this paper, we primarily research the modelling of the cathode and anode and the nonlinear controller design for pressure control, as well as air flow control. In detail, control-oriented models are established for cathode and anode controller design. Owing to the existence of model uncertainty and disturbances, such as humidity, temperature, and water vapour, an extended state observer (ESO) is designed to estimate and compensate for these influences. Cathode and anode pressure controls are synthesized in the uniform control scheme. For air flow control, a feedforward channel based on the air flow model of the compressor and a feedback channel based on the proportional–integral (PI) controller are proposed to regulate air flow. The proposed control methods are validated by experiments under different operating conditions of PEMFCs.     

Differentiated transmission services and optimization based on two‐dimensional forwarding for Internet traffic in the AS

Two‐dimensional routing (TD routing) implements flexible multipath transmission according to the inherent fields of IP packets. However, it may cause large overhead on routers' control plane and data plane. Focusing on autonomous systems with multiple exits, this paper proposes a differentiated transmission services and optimization based on two‐dimensional forwarding for Internet traffic in the autonomous system (AS) (DOTF). The optimal path from the access router to the border router is calculated by the border router. Then two‐dimensional routing information (TDRI) is advertised hop by hop along the reverse path of the optimal path to establish a TD transmission path. DOTF propagates routing information by extending the open shortest path first (OSPF). It compresses message content and optimizes the TDRI structure. TDRI is only released on the specific paths, which greatly reduces the resource consumption in the routers' control plane and data plane. We also analyze the merging of TD routing and one‐dimensional routing (OD routing), reducing the deployment of TD routing entries (TD‐REs). Our experiments on real routers demonstrate the performance of DOTF. The convergence characteristics of TD routing are also analyzed.     

Adaptive integral robust control of hydraulic systems with asymptotic tracking

In this paper, an adaptive integral robust controller is developed for high accuracy motion tracking control of a double-rod hydraulic actuator. We take unknown constant parameters including the load and hydraulic parameters, and lumped unmodeled disturbances in inertia load dynamics and pressure dynamics into consideration. A discontinuous projection-based adaptive control law is constructed to handle parametric uncertainties, and an integral of the sign of the extended error based robust feedback term to attenuate unmodeled disturbances. Moreover, the present controller does not require a priori knowledge on the bounds of the lumped disturbances and the gain of the designed robust control law can be tuned itself. The major feature of the proposed full state controller is that it can theoretically guarantee global asymptotic tracking performance with a continuous control input, in the presence of various parametric uncertainties and unmodeled disturbances such as unmodeled dynamics as well as external disturbances via Lyapunov analysis. Comparative experimental results are obtained for motion control of a double-rod hydraulic actuator and verify the high-performance nature of the proposed control strategy.     

基于ESO的NLPID神经网络控制器的设计

针对传统PID控制自适应和抗扰能力欠佳的问题,提出了一种具有强抗扰动能力的NLPID神经网络控制方法。该方法通过扩张状态观测器对系统建模中不确定性因素以及系统的外部扰动实时观测进行前馈补偿,并与非线性PID神经网络控制相结合,实现对非线性、时变、不确定性、受未知外扰系统的最优PID自适应抗扰控制。通过Matlab仿真结果与传统PID控制对比分析,表明该方法具有优良的动态品质和静态性能,在非线性系统控制领域拥具有重要的应用价值。     

Sliding mode control combined with extended state observer for an ankle exoskeleton driven by electrical motor

A novel sliding mode control combined with extended state observer (ESO) is proposed for an ankle exoskeleton driven by electrical motor. During the process of assisting, it is necessary to design an effective controller for assisting torque of ankle exoskeleton. However, the parameter uncertainty of complex dynamics model and the irregular motion of human ankle may affect the torque control accuracy. For a high control precision of assisting torque when facing the modeling uncertainty, the sliding mode control is employed, but a large switching gain is usually needed in order to suppress the disturbance, which cause the control signal vibrate greatly. ESO can observe and suppress the disturbance and modeling uncertainty, but its tracking performance needs to be improved. Therefore, the proposed complex controller takes the advantages of sliding mode control and extended state observer, which can not only improve torque tracking performance but also overcome the disturbance force caused by the change of human joint angle without increasing chattering of control signal. Experimental studies are carried out to validate the effectiveness of the proposed control. The results show the presented controller have better torque tracking performance and robustness stability, and the proposed controller can reduce the chattering compared with the tradition sliding mode control.