共查询到20条相似文献，搜索用时 15 毫秒
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In this paper, a novel robust backstepping control strategy is introduced to achieve high-accuracy tracking performance for electro-hydraulic servo systems (EHSSs) without velocity information in the presence of uncertainties and disturbances. Firstly, system dynamics of the studied EHSS considering parameter deviations, modeling errors, and unknown external loads which are grouped into lumped mismatched and matched disturbances in the mechanical system and pressure dynamics, respectively, are developed. On the basis of the sliding mode theory, two extended sliding mode observers (ESMOs) are originally established to simultaneously estimate the immeasurable angular velocity of the actuator, and lumped mismatched and matched uncertainties. As a consequence, an observer-based controller is designed using the conventional backstepping technique to ensure a highly accurate tracking position control. In addition, the stability of the observer and overall closed-loop control system is conclusively proven through the Lyapunov theory. Finally, several numerical simulations for an EHSS with a hydraulic rotary actuator are conducted to demonstrate the advantage of the recommended method compared to the existing well-known extended state observer-based control approaches. 相似文献
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Xiaoxia Han Zhixiang Chen Yongbao Feng Jian Xie Xiaoling Wei Liejiang Wei 《Asian journal of control》2023,25(3):1888-1904
Electrohydrostatic actuators (EHAs) are used to replace traditional centralized hydraulic systems to reduce weight and improve efficiency and maintainability. This paper proposes a cascade active disturbance rejection control (C-ADRC) method for single-rod EHAs with parametric uncertainties and severe external disturbances. The studied EHA can be transformed into a cascade connection of a first-order pressure system and a second-order position system. Two linear active disturbance rejection controllers are designed for the inner pressure system and the outer position system to estimate and compensate for various uncertainties in the two loops, respectively. The uniqueness of the C-ADRC is that the two linear active disturbance rejection controllers are designed by making full use of the measurable states and known model information of the EHA system. It is theoretically proved that the closed-loop system is semi-globally uniformly ultimately bounded. Moreover, the proposed controller can theoretically ensure position tracking with desired accuracy as the bandwidth of extended state observers (ESOs) becomes sufficiently high. Simulation and experimental results verify the effectiveness of the proposed method. 相似文献
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在电液伺服系统优化设计的研究中,针对电液位置伺服系统的高阶非线性特性、系统参数不确定性以及系统状态信号测量困难的情况,提出一种基于滑模状态观测器的反演控制策略.策略采用滑模方法设计状态观测器,只需要位置传感器,不需要速度传感器和加速度传感器.对采用状态观测器之后的系统,设计反演控制器,针对系统中的不确定性,在反演控制的最后一步采用滑模控制设计,基于Lyapunov方法证明了系统中所有信号是一致最终有界的,闭环系统是稳定的.仿真结果表明,上述策略为电液伺服系统优化设计提供了参考. 相似文献
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针对多变量、不稳定的近空间飞行器姿态系统,在系统存在参数不确定和外部干扰的情况下,并考虑执行器动态和输入受限,提出一种鲁棒可重构跟踪控制策略.首先,利用二阶滑模干扰观测器分别重构姿态、角速率回路的复合干扰;其次,采用鲁棒二阶滑模积分滤波器的反推(backstepping)方法避免了控制器设计中微分项膨胀问题,利用鲁棒项抵消重构误差对系统的影响,以实现姿态控制器设计.然后,在考虑执行器动态、输入受限及舵面卡死故障下,给出一种线性矩阵不等式的在线优化舵面分配算法,以实现飞行器的姿态角渐近跟踪期望的制导指令.最后,仿真结果表明所提出的方法具有良好的跟踪控制性能. 相似文献
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Jiajun Wang 《IEEE/CAA Journal of Automatica Sinica》2018,5(6):1128-1135
A novel speed-assigned method is applied to the position tracking control of switched reluctance motor (SRM). A speed control freedom can be drawn into the position control through speed assignment. Adaptive backstepping control is used to design the position controller for the SRM. The accuracy of position tracking of the SRM can be enhanced with speed assignment. A disturbance observer is further designed to enhance the estimation accuracy of the unknown load torque. Simulation results certify that the design scheme is right and effective. 相似文献
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The control effectors of reusable launch vehicle (RLV) can produce significant perturbations and faults in reentry phase. Such a challenge imposes tight requirements to enhance the robustness of vehicle autopilot. Focusing on this problem, a novel finite‐time fault‐tolerant control strategy is proposed for reentry RLV in this paper. The key of this strategy is to design an adaptive‐gain multivariable finite‐time disturbance observer (FDO) to estimate the synthetical perturbation with unknown bounds, which is composed of model uncertainty, external disturbance, and actuator fault considered as the partial loss of actuator effectiveness in this work. Then, combined with the finite‐time high‐order observer and differentiator, a continuous homogeneous second‐order sliding mode controller based on the terminal sliding mode and super‐twisting algorithm is designed to achieve a fast and accurate RLV attitude tracking with chattering attenuation. The main features of the integrated control strategy are that the adaptation algorithm of FDO can achieve non‐overestimating values of the observer gains and the second‐order super‐twisting sliding mode approach can obtain a more elegant solution in finite time. Finally, simulation results of classical RLV (X‐33) are provided to verify the effectiveness and robustness of the proposed fault‐tolerant controller in tracking the guidance commands. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
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针对轧机传动侧和操作侧液压伺服位置系统存在不一致性而引起两侧位置不同步的问题, 提出一种自抗扰同步控制方法.首先建立了液压伺服位置同步系统动态机理模型, 并在考虑两侧位置伺服系统都具有参数摄动及外负载波动的情况下, 设计了扩张状态观测器对同步系统中不确定性和不一致性进行估计, 并采用状态误差反馈律给予主动补偿, 同时消除同步误差. 仿真和实验结果表明, 所提出的同步控制方法能够使两侧液压伺服位置系统动态响应和稳态特性保持一致, 并提高了单侧子系统的动态性能及抗干扰能力. 相似文献
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针对小型无人直升机在飞行过程中容易受到非匹配扰动影响的特点,本文设计了一种基于新型滑模控制方法的轨迹跟踪控制器.首先,建立了无人直升机系统的非线性数学模型,并对该模型进行近似反馈线性化处理,同时将模型分为位置和偏航两个子系统;然后,利用扩展扰动观测器对复合扰动以及非匹配扰动的各阶导数的估计值,设计新型时变滑模面,得到滑模控制律,并给出了控制系统的稳定性分析;最后,仿真结果验证了控制方法的有效性和优越性.该新型滑模控制方法的优越性主要体现在:对非匹配扰动具有较强的鲁棒性,以及能有效地抑制抖振现象. 相似文献
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This paper focuses on the design of nonlinear robust controller and disturbance observer for the longitudinal dynamics of a hypersonic vehicle (HSV) in the presence of parameter uncertainties and external disturbances. First, by combining terminal sliding mode control (TSMC) and second-order sliding mode control (SOSMC) approach, the secondorder terminal sliding control (2TSMC) is proposed for the velocity and altitude tracking control of the HSV. The 2TSMC possesses the merits of both TSMC and SOSMC, which can provide fast convergence, continuous control law and hightracking precision. Then, in order to increase the robustness of the control system and improve the control performance, the sliding mode disturbance observer (SMDO) is presented. The closed-loop stability is analyzed using the Lyapunov technique. Finally, simulation results illustrate the effectiveness of the proposed method, as well as the improved overall performance over the conventional sliding mode control (SMC). 相似文献
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Sliding mode control (SMC) has been widely investigated in recent years.In this paper,a class of secondorder SMC is proposed and used to achieve good tracking performance in servo systems.SMC has good ... 相似文献
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For reducing throttling loss in a pilot oil pipe in a hydraulic system based on common pressure rail, this paper proposes a solution that increases efficiency by reducing the relieving pressure. In order to compensate for the resulting control performance degradation, the paper takes a valve controlled swing motor system under low pressure as the research aim. Considering the uncertainty of external disturbance and flow parameters, the mathematical model of the system is established, using an extended state observer to estimate the external disturbances in real time to increase the compensation value and state feedback for the robust backstepping sliding mode controller. Finally, the simulation results confirm the control algorithm proposed is effective for keeping control performance in decreasing pressure conditions. 相似文献
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In this paper, the disturbance observer–based chattering‐free discrete‐time sliding mode control (DSMC) approach is proposed for systems with external disturbances. The proposed disturbance observer, which makes full use of the state and input information at the current and last steps, improves the estimation accuracy and achieves accurate compensation for disturbances. Then, with the help of disturbance observer, a new reaching law, which contains not only a nonsmooth term with a dynamically adjusted gain parameter but also a second order difference of the disturbance, is proposed to reduce the range of the quasi‐sliding mode band and eliminate chattering. The proposed DSMC approach realizes the active disturbance rejection and strong robustness. Finally, a simulation example is presented to verify the effectiveness of the proposed method. 相似文献
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This research deals with developing an intelligent trajectory tracking control approach for an aircraft in the presence of internal and external disturbances. Internal disturbances including actuators faults, unmodeled dynamics, and model uncertainties as well as the external disturbances such as wind turbulence significantly affect the performance of the common trajectory tracking control approaches. There are several fault‐tolerant control approaches in the literature to overcome the effects of specific actuator or sensor faults during the flight. However, trajectory tracking control of an air vehicle in the presence of unexpected faults and simultaneous presence of wind turbulence is still a challenging problem. In this paper, an intelligent neural network‐based model predictive control structure is proposed, where the prediction model is updated in each iteration based on a novel proposed online sequential multimodel structure. A hybrid offline‐online learning algorithm is adopted in the introduced online sequential multimodel structure to identify the time‐varying dynamics of the system. The proposed control structure can satisfactorily deal with unexpected actuator faults and structural damages as well as unmodeled dynamics and wind turbulence. The stability of the closed‐loop system is proved under some realistic assumptions. The simulation results demonstrate the high capability of the proposed approach for trajectory tracking control of a conventional aircraft in the simultaneous presence of system faults and external disturbances. 相似文献
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This paper is concerned with the design of a robust adaptive tracking control scheme for a class of variable stiffness actuators (VSAs) based on the lever mechanisms. For these VSAs based on the lever mechanisms, the AwAS‐II developed at Italian Institute of Technology (IIT) is chosen as the study object, and it is an enhanced version of the original realization AwAS (actuator with adjustable stiffness). Firstly, for the dynamic model of the AwAS‐II system in the presence of parametric uncertainties, unknown bounded friction torques, unknown bounded external disturbance and input saturation constraints, by using the coordinate transformations and the static state feedback linearization, the state space model of the AwAS‐II system with composite disturbances and input saturation constraints is transformed into an uncertain multiple‐input multiple‐output (MIMO) linear system with lumped disturbances and input saturation constraints. Subsequently, a combination of the feedback linearization, disturbance observer, sliding mode control and adaptive input saturation compensation law is adopted for the design of the robust tracking controller that simultaneously regulates the position and stiffness of the AwAS‐II system. Under the proposed controller, the semi‐global uniformly ultimately bounded stability of the closed‐loop system has been proved via Lyapunov stability analysis. Simulation results illustrate the effectiveness and the robustness of the proposed robust adaptive tracking control scheme. 相似文献
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为提高轻武器伺服跟踪系统的位置跟踪精度,提出一种基于干扰观测器的CMAC-PD复合控制方法。将摩擦、电机力矩波动和模型参数不确定性等影响系统性能的因素视为干扰,采用一种新型的干扰观测器对其进行估计并加以补偿。在此基础上,提出一种基于CMAC与PD的复合控制方法。对比仿真实验表明,基于干扰观测器的CMAC-PD复合控制能更有效地抑制干扰对轻武器伺服跟踪系统动态性能的影响,进而使系统获得更高的跟踪精度。 相似文献
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Jinhua She Kou Miyamoto Qing-Long Han Min Wu Hiroshi Hashimoto Qing-Guo Wang 《IEEE/CAA Journal of Automatica Sinica》2023,10(4):957-968
Active disturbance-rejection methods are effective in estimating and rejecting disturbances in both transient and steady-state responses.This paper presents a deep observation on and a comparison between two of those methods:the generalized extended-state observer(GESO) and the equivalent input disturbance(EID) from assumptions,system configurations,stability conditions,system design,disturbance-rejection performance,and extensibility.A time-domain index is introduced to assess the disturbance-r... 相似文献
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Bhagyashri Tamhane Dharmveer Singh Shailaja Kurode Prasad Parkhi 《Asian journal of control》2016,18(2):784-787
Control of the seeker is important for successful operation of a missile. This paper proposes robust sliding mode control (SMC) with sliding mode observer (SMO) for the seeker. The SMO is designed for the extended state system wherein the disturbance is considered as an additional state. Estimated disturbance is used to update the SMC law. 相似文献
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针对可穿戴上肢外骨骼系统在外部干扰及参数不确定条件下的轨迹跟踪问题,提出了一种基于观测器的固定时间控制策略.首先,采用拉格朗日方法对五自由度上肢外骨骼系统的动力学模型进行面向控制处理.其次,考虑模型中存在参数不确定及外部干扰,基于改进超螺旋算法设计了固定时间干扰观测器,实现对系统干扰的实时估计,完成对控制器的在线补偿;在此基础上,设计了非奇异终端滑模固定时间控制律,保证外骨骼关节角度跟踪误差在固定时间内收敛至原点.再次,基于Lyapunov方法证明了闭环系统的稳定性.最后,通过对比和数值仿真结果证明所提出控制策略的有效性. 相似文献