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Nonlinear robust adaptive control for bidirectional stabilization system of all-electric tank with unknown actuator backlash compensation and disturbance estimation

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Defence Technology（防务技术） 2024年第2期32卷 144-158页

作者： Shusen Yuan Wenxiang Deng jianyong yao Guolai Yang School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094China

Since backlash nonlinearity is inevitably existing in actuators for bidirectional stabilization system of allelectric tank,it behaves more drastically in high maneuvering environments.In this work,the accurate tracking control for bidirectional stabilization system of moving all-electric tank with actuator backlash and unmodeled disturbance is solved.By utilizing the smooth adaptive backlash inverse model,a nonlinear robust adaptive feedback control scheme is presented.The unknown parameters and unmodelled disturbance are addressed separately through the derived parametric adaptive function and the continuous nonlinear robust term.Because the unknown backlash parameters are updated via adaptive function and the backlash effect can be suppressed successfully by inverse operation,which ensures the system stability.Meanwhile,the system disturbance in the high maneuverable environment can be estimated with the constructed adaptive law online improving the engineering practicality.Finally,Lyapunov-based analysis proves that the developed controller can ensure the tracking error asymptotically converges to zero even with unmodeled disturbance and unknown actuator backlash.Contrast co-simulations and experiments illustrate the advantages of the proposed approach.

关键词： Bidirectional stabilization system Robust control Adaptive control Backlash inverse Disturbance estimation

Disturbance observer based actor-critic learning control for uncertain nonlinear systems

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Chinese Journal of Aeronautics 2023年第11期36卷 271-280页

作者： Xianglong LIANG Zhikai yao yaowen GE jianyong yao School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094China College of Artificial Intelligence Nanjing University of Post and TelecommunicationNanjing 210023China

This paper investigates the disturbance observer based actor-critic learning control for a class of uncertain nonlinear systems in the presence of unmodeled dynamics and time-varying disturbances.The proposed control algorithm integrates a filter-based design method with actor-critic learning architecture and disturbance observer to circumvent the unmodeled dynamic and the timevarying disturbance.To be specific,the actor network is employed to estimate the unknown system dynamic,the critic network is developed to evaluate the control performance,and the disturbance observer is leveraged to provide efficient estimation of the compounded disturbance which includes the time-varying disturbance and the actor-critic network approximation error.Consequently,highgain feedback is avoided and the improved tracking performance can be expected.Moreover,a composite weight adaptation law for actor network is constructed by utilizing two types of signals,the cost function and the modeling error.Eventually,theoretical analysis demonstrates that the developed controller can guarantee bounded stability.Extensive simulations and experiments on a robot manipulator are implemented to validate the performance of the resulted control strategy.

关键词： Actor-critic structure Composite adaptation Disturbance observer Robot manipulator Uncertain nonlinear system

High dynamic output feedback robust control of cascaded extended state observer

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Chinese Journal of Aeronautics 2022年第7期35卷 300-309页

作者： Wenxiang DENG jianyong yao Zongxia JIAO Xiaochao LIU School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094China the State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310027China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China

High dynamic tracking performance is a key technical index of hydraulic flight motion simulator(HFMS).However,the strong nonlinearities,various model uncertainties and measurement noise in hydraulic actuation systems limit the high dynamic performance improvement.In this paper,the outer axis frame of a HFMS is taken as a case study and its nonlinear dynamic model with consideration of strong nonlinearities,matched and mismatched uncertainties is established.A novel cascaded extended state observer(ESO)is proposed to estimate the unavailable system states to avoid the adverse effect of measurement noise on control performance.Meanwhile,the designed cascaded ESO also produces estimates of matched and mismatched uncertainties.Then,an output feedback robust controller(OFRC)is proposed by integrating the cascaded ESO with a robust integral of the sign of the error(RISE)feedback based on the backstepping framework.The proposed controller achieves compensation of both matched and mismatched model uncertainties in an output feedback form.Theoretical analysis indicates that the proposed OFRC ensures the boundedness of all closed-loop system signals in the presence of matched and mismatched timevarying model uncertainties.Excellent asymptotic tracking performance can also be obtained when the model uncertainties are time-invariant.Comparative experimental results show that the proposed OFRC achieves significant performance improvement compared with the extensively employed PI control with velocity feedforward(VFPI).

关键词： Flight motion simulator High dynamic tracking Hydraulic actuator Observer Output feedback Robust control

Observer-based motion axis control for hydraulic actuation systems

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中国航空学报:英文版 2023年第9期36卷 408-415页

作者： Xiaowei YANG yaowen GE Wenxiang DENG jianyong yao School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094China

Unknown dynamics including mismatched mechanical dynamics(i.e.,parametric uncertainties,unmodeled friction and external disturbances)and matched actuator dynamics(i.e.,pressure and flow characteristic uncertainties)broadly exist in hydraulic actuation systems(HASs),which can hinder the achievement of high-precision motion axis control.To surmount the practical issue,an observer-based control framework with a simple structure and low computation is developed for HASs.First,a simple observer is utilized to estimate mismatched and matched unknown dynamics for feedforward compensation.Then combining the backstepping design and adaptive control,an appropriate observer-based composite controller is provided,in which nonlinear feedback terms with updated gains are adopted to further improve the tracking accuracy.Moreover,a smooth nonlinear filter is introduced to shun the“explosion of complexity”and attenuate the impact of sensor noise on control performance.As a result,this synthesized controller is more suitable for practical use.Stability analysis uncovers that the developed controller assures the asymptotic convergence of the tracking error.The merits of the proposed approach are validated via comparative experiment results applied in an HAS with an inertial load as well.

关键词： Adaptive control Asymptotic convergence Hydraulic actuation system Sensor noise Unknown dynamics compensation

Efficacy and safety of PD-1 blockade plus long-course chemoradiotherapy in locally advanced rectal cancer(NECTAR):a multi-center phase 2 study

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Signal Transduction and Targeted Therapy 2024年第4期9卷 1721-1729页

作者： Zhengyang Yang Jiale Gao jianyong Zheng Jiagang Han Ang Li Gang Liu Yi Sun Jie Zhang Guangyong Chen Rui Xu Xiao Zhang Yishan Liu Zhigang Bai Wei Deng Wei He Hongwei yao Zhongtao Zhang Department of General Surgery Beijing Friendship HospitalCapital Medical UniversityState Key Lab of Digestive HealthNational Clinical Research Center for Digestive DiseasesBeijingChina Department of Gastrointestinal Surgery The First Affiliated Hospital of Air Force Medical UniversityXi'anChina Department of General Surgery Beijing Chaoyang HospitalCapital Medical UniversityBeijingChina Department of General Surgery Beijing Xuanwu HospitalCapital Medical UniversityBeijingChina Department of General Surgery Tianjin Medical University General HospitalTianjinChina Department of Anorectal Tianjin People's HospitalTianjinChina Department of Radiology Beijing Friendship Hospital Capital Medical UniversityBeijingChina Department of Pathology Beijing Friendship HospitalCapital Medical UniversityBeijingChina Department of Thoracic Surgery/Institute of Thoracic Oncology West China HospitalSichuan UniversityChengduChina

Adding PD-1 blockade in the neoadjuvant regimens for locally advanced rectal cancer(LARC)patients with microsatellite stable(MsS)/mismatch repair-proficient(pMMR)tumors is an attractive,but debatable strategy.This phase 2,multicenter,prospective,single-arm study enrolled patients from 6 centers from June 2021 to November 2022.Locally advanced rectal cancer(LARC,cT_(3-4a)N_(0)M_(0) and cT_(1-4a)N_(1-2)M_(0))patients aged≥18 years with the distance from distal border of tumor to anal verge≤10 cm(identified by Magnetic Resonance Imaging)were qualifed for inclusion.The patients received long-course radiotherapy(50 Gy/25 fractions,2 Gy/fraction,5 days/week)and three 21-day cycles capecitabine(850-1000 mg/m2,bid,po,day1-14)and three 21-day cycles tislelizumab(200 mg,iv.gtt,day8)as neoadjuvant.Total mesorectal excision(TME)was 6-12 weeks after the end of radiotherapy to achieve radical resection.A total of 50 patients were enrolled in this study.The pathological complete response rate was 40.0%[20/50,95%confidence interval(CI):27.61-53.82%],while 15(30.0%,95%CI:19.1-43.75%),9(18.0%,95%CI:9.77-30.8%),2(4.0%,95%CI:1.10-13.46%)patients respectively achieved grade 1,2,and 3 tumor regression.Treatment-related adverse events(TRAEs)occurred in 28(56.0%)LARC patients,including 26(52.0%)with grade I-II and 2(4.0%)with grade II(1 with grade 3 immune-related colitis and 1 with grade 3 rash).PD-1 blockade plus long-course chemoradiotherapy(CRT)showed promising therapeutic effects according to pathological complete response rate and is well-tolerated in LARC patients.A larger randomized controlled study is desired to further validate the above findings.

关键词： rectal cancer phase

Model-based nonlinear control of hydraulic servo systems： Challenges, developments and perspectives

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Frontiers of Mechanical Engineering 2018年第2期13卷 179-210页

作者： jianyong yao School of Mechanical Engineering Nanjing University of Science and Technology Nanjing 210094 China

Hydraulic servo system plays a significant role in industries, and usually acts as a core point in control and power transmission. Although linear theory-based control methods have been well established, advanced controller design methods for hydraulic servo system to achieve high performance is still an unending pursuit along with the development of modem industry. Essential nonlinearity is a unique feature and makes model-based nonlinear control more attractive, due to benefit from prior knowledge of the servo valve controlled hydraulic system. In this paper, a discussion for challenges in model-based nonlinear con- trol, latest developments hydraulic servo systems are and brief perspectives of presented： Modelling uncer- tainty in hydraulic system is a major challenge, which includes parametric uncertainty and time-varying distur- bance; some specific requirements also arise ad hoc difficulties such as nonlinear friction during low velocity tracking, severe disturbance, periodic disturbance, etc.; to handle various challenges, nonlinear solutions including parameter adaptation, nonlinear robust control, state and disturbance observation, backstepping design and so on, are proposed and integrated, theoretical analysis and lots of applications reveal their powerful capability to solve pertinent problems; and at the end, some perspectives and associated research topics （measurement noise, constraints, inner valve dynamics, input nonlinearity, etc.） in nonlinear hydraulic servo control are briefly explored and discussed.

关键词： hydraulic servo system adaptive control robust control nonlinear friction disturbance compensation repetitive control noise alleviation constraint control

基于神经网络的比例伺服阀阀芯液动力补偿鲁棒智能控制

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机械工程学报 2024年第4期60卷 126-133页

作者：周宁姚建勇邓文翔南京理工大学机械工程学院南京210094

比例伺服阀广泛应用于智能工程机械、国防装备等高端液压系统中。对于智能比例伺服阀而言,液动力是限制其智能化程度提升最主要的因素。针对上述问题,提出一种基于神经网络的阀芯液动力补偿鲁棒控制器(Flow force compensation neural n... 详细信息

比例伺服阀广泛应用于智能工程机械、国防装备等高端液压系统中。对于智能比例伺服阀而言,液动力是限制其智能化程度提升最主要的因素。针对上述问题,提出一种基于神经网络的阀芯液动力补偿鲁棒控制器(Flow force compensation neural network-based robust controller,FF-NNRC)。首先利用Fluent软件,获取在不同阀芯位移、压力边界条件下的液动力信息,用于模拟真实工况下的液动力扰动。设计神经网络学习逼近液动力扰动,从而在模型前馈补偿项构建液动力动态补偿项,针对系统其他扰动及神经网络估计误差设计鲁棒项加以克服。Lyapunov稳定性理论证明提出的控制策略可以实现系统的有界稳定。仿真结果表明,与传统的PID控制器和基于名义值模型补偿的鲁棒控制器(Model compensation robust controller,MC-RC)相比,所提出的控制器具有更高的控制精度和抗干扰能力。

关键词：液动力计算流体动力学神经网络模型补偿鲁棒控制

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泵控多连杆式起竖系统自抗扰力同步控制

兵工学报 2024年第6期45卷 1906-1920页

作者：朱威霖姚建勇刘家辉黎兰张佳林南京理工大学机械工程学院江苏南京210094 北京航天发射技术研究所北京100076

针对泵控多连杆式起竖系统存在的非线性、模型不确定性和双缸不同步引起的力纷争问题,提出一种双缸起竖系统自抗扰力同步控制设计方法。考虑多连杆起竖机构运动学特性和闭式泵控液压系统的压力流量动态,建立多连杆式起竖系统动力学模型... 详细信息

针对泵控多连杆式起竖系统存在的非线性、模型不确定性和双缸不同步引起的力纷争问题,提出一种双缸起竖系统自抗扰力同步控制设计方法。考虑多连杆起竖机构运动学特性和闭式泵控液压系统的压力流量动态,建立多连杆式起竖系统动力学模型,通过扩张状态观测器估计系统干扰和模型不确定性,以在控制器设计过程中进行补偿,同时融合复合力同步控制方法,增强系统克服负载偏载、外干扰等引起的力纷争。基于Lyapunov理论分析证明了多连杆式双缸起竖系统的渐近跟踪和力同步性能。通过中速和快速恒功率起竖对比试验,验证所提自抗扰力同步控制策略的有效性,获得了良好的起竖跟踪和力同步控制性能。

关键词：多连杆起竖系统泵控系统自抗扰控制力同步控制

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考虑输入时滞的舵机伺服系统自适应指令滤波输出反馈控制

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西安交通大学学报 2024年第3期58卷 149-161页

作者：郭峻秀胡健姚建勇黄玲谭天乐刘宇南京理工大学机械工程学院南京210094 上海航天控制技术研究所上海201108

针对舵机伺服系统运行过程中存在复杂非线性以及信号输入时滞、使系统的精度降低,严重时甚至造成系统失稳的问题,提出了一种考虑输入时滞的自适应指令滤波输出反馈控制策略。首先,将系统中存在的输入时滞考虑为控制器信号输入时滞,给出... 详细信息

针对舵机伺服系统运行过程中存在复杂非线性以及信号输入时滞、使系统的精度降低,严重时甚至造成系统失稳的问题,提出了一种考虑输入时滞的自适应指令滤波输出反馈控制策略。首先,将系统中存在的输入时滞考虑为控制器信号输入时滞,给出舵机伺服系统状态方程,选用梯度下降法设计时滞估计律对未知时滞进行估计;其次,将系统中存在的复杂非线性统一为扰动,选用扩展状态观测器(ESO)加以估计,将观测的系统状态值用于设计控制量实现输出反馈控制;然后,选用指令滤波将高阶求导过程转化为求积分,实现信号滤波以抑制微分噪声;最后,基于Lyapunov-Krasovskii泛函稳定性定理证明控制器实现系统有界稳定。仿真及实验表明,所提的控制方法与传统反步控制方法、自抗扰控制和比例微分积分(PID)控制方法相比,响应时间分别提升了92%、88%和51%,跟踪精度分别提升了90%、84%和26%。

关键词：舵机伺服系统输入时滞输出反馈指令滤波