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Fixed-Time Controller Design for a Quadrotor UAV with Asymmetric Output Error Constraints

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系统科学与复杂性学报:英文版 2023年第5期36卷 1981-2000页

作者： WANG Fang MA Zhigang ZHOU Chao ZHANG Zheng HUA Changchun zong qun School of Science Yanshan UniversityQinhuangdao 066004China Ocean College Hebei Agricultural UniversityQinhuangdao 066003China School of Electric Engineering Yanshan UniversityQinhuangdao 066004China School of Electrical and Information Engineering Tianjin UniversityTianjin 300072China

In this article,a fixed-time tracking control strategy is proposed for a quadrotor UAV(QUAV)with external disturbance and asymmetric output error constraints.Firstly,a dynamic model of the QUAV is transformed into a strict feedback system with external disturbance,and it is decoupled into attitude subsystem and position subsystem for simplifying controller design.Secondly,an asymmetric tangent barrier Lyapunov function(ATBLF)is applied to solve the tracking error constraints problem,and a fixed-time control law is designed.Meanwhile,a fixed-time disturbance observer(FTDO)is designed to cope with external disturbance.Then,it is proved that the designed controller guarantees the tracking error remains within the constraint ranges and converges to zero in fixed-time by Lyapunov stability theory.Finally,the effectiveness of the proposed control scheme is verified by numerical simulations.

关键词： Asymmetric tangent barrier Lyapunov function(ATBLF) fixed-time disturbance observer(FTDO) output error constraints quadrotor UAV(QUAV)

Super twisting sliding mode control for a flexible air-breathing hypersonic vehicle based on disturbance observer

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Science China(Information Sciences) 2015年第7期58卷 84-98页

作者： zong qun DONG Qi WANG Fang TIAN BaiLing College of Electric Engineering and Automation Tianjin University School of Science Yanshan University

A robust finite time sliding mode control strategy is proposed in this paper for a flexible air-breathing hypersonic vehicle(FAHV) model with aerodynamic parameter uncertainty. The strong coupling among the aerodynamics, the propulsion system and the flexibility effects makes the problem more challenging. Firstly, to reduce the complexity of the controller design, the FAHV model is transformed into three subsystems(velocity subsystem, altitude and flight path angle subsystem, attack of angle and pitch rate subsystem). Secondly, based on super-twisting algorithm, a novel finite time disturbance observer and an improved sliding mode controller are designed to ensure the finite time stability of each subsystem. The proposed disturbance observer can estimate the uncertainty and the derivative of virtual control in finite time. Finally, simulation results are presented to show the precision and rapidness in tracking the reference trajectory and validate the effectiveness of the designed controller.

关键词： flexible air-breathing hypersonic vehicle(FAHV) disturbance observer sliding mode control super-twisting algorithm finite time s

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未知环境下无人机集群智能协同探索路径规划

工程科学学报 2024年第7期46卷 1197-1206页

作者：王伟伦尤明孙磊张秀云宗群天津大学电气自动化与信息工程学院天津300072 沈阳飞机设计研究所沈阳110035 陆军航空兵研究所北京101100

随着无人机执行任务复杂性与环境种类多样性的不断提高,多无人机集群系统逐渐得到国内外的广泛关注,无人机路径规划成为当前研究热点.考虑到传统路径规划算法一般需要先验地图信息,在搜索救援等环境未知场景中难以满足,本文提出了一种... 详细信息

随着无人机执行任务复杂性与环境种类多样性的不断提高,多无人机集群系统逐渐得到国内外的广泛关注,无人机路径规划成为当前研究热点.考虑到传统路径规划算法一般需要先验地图信息,在搜索救援等环境未知场景中难以满足,本文提出了一种基于强化学习的未知环境下的无人机集群协同探索路径规划方法.首先,考虑无人机集群协同探索任务特点及动力学、避碰避障等约束条件,基于马尔可夫决策过程,建立无人机集群协同探索博弈模型与评价准则.其次,提出基于强化学习方法的无人机集群协同探索方法,建立基于策略-评判网络的双网络架构,并利用随机地图增强探索方法面对未知环境的泛化能力.每架无人机在探索过程中不断收集地图信息,并基于环境信息和个体间的共享信息调整自身策略,通过迭代训练实现未知环境下的集群协同探索.最后,基于Unity搭建无人机集群协同探索虚拟仿真平台,并与非合作的单智能体算法进行对比试验,验证了本文所提算法在任务成功率、任务完成效率和回合奖励等方面均具有优势.

关键词：无人机集群深度强化学习自主探索路径规划

Adaptive Backstepping Sliding Mode Control of Uncertain Semi-Strict Nonlinear Systems and Application to Permanent Magnet Synchronous Motor

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Journal of Systems Science & Complexity 2021年第2期34卷 552-571页

作者： WANG Fang WANG Jian-mei WANG Kun zong qun HUA Changchun School of Science Yanshan UniversityQinhuangdao 066004China School of Electrical and Information Engineering Tianjin UniversityTianjin 300072China School of Electrical and Engineering Yanshan UniversityQinhuangdao 066004China

A disturbance observer(DOB)based-backstepping sliding mode control scheme is discussed for a class of semi-strict nonlinear system with unknown parameters and mismatched uncertainty.Firstly,adaptive technique and DOB are respectively applied to tackle the unknown parameters and mismatched uncertainty,where the DOB can effectively alleviate the chattering problem of sliding mode control(SMC).Then,exponential sliding mode surface is proposed to improve the convergence rate of the sliding mode state.The‘explosion of complexity’problem inherent in conventional backstepping control is overcome by designing the novel first-order filter.The stability of the closed-loop system is analyzed in the framework of Lyapunov stability theory,in which the tracking error converges to an arbitrarily small neighborhood around zero(ASNZ).At last,two examples are given to illustrate the effectiveness of the proposed control strategy.

关键词： Adaptive law DOB filter semi-strict nonlinear system SMC

考虑推力陷阱的组合动力飞行器切换控制方法研究

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空军工程大学学报 2024年第2期25卷 21-31页

作者：张秀云李梦龙田栢苓李智禹宗群天津大学电气自动化与信息工程学院天津300072

针对组合动力飞行器动力切换时的推力陷阱问题,提出了一种考虑推力陷阱的组合动力飞行器切换控制方法。首先,针对组合动力飞行器正常飞行控制需求,基于超螺旋滑模控制方法,设计了正常飞行控制器,从而实现飞行器受扰动情况下的有限时间... 详细信息

针对组合动力飞行器动力切换时的推力陷阱问题,提出了一种考虑推力陷阱的组合动力飞行器切换控制方法。首先,针对组合动力飞行器正常飞行控制需求,基于超螺旋滑模控制方法,设计了正常飞行控制器,从而实现飞行器受扰动情况下的有限时间稳定跟踪参考指令;其次考虑组合动力飞行器动力切换引起的推力损失带来的控制约束,设计了输入约束控制器,实现模态转换阶段跟踪误差有限时间收敛的同时减小推力需求;然后考虑正常情况及模态转换阶段控制器的结合,设计了组合发动机软切换控制方法;最后通过仿真验证了所设计的控制器能够有效规避推力损失现象,并且能够有效保障切换控制系统的稳定性及鲁棒性。

关键词：组合动力飞行器推力陷阱切换控制输入约束控制

Effects of Aeroelastic Modes on the dynamics of a Flexible Hypersonic Vehicle

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Effects of Aeroelastic Modes on the dynamics of a Flexible H...

Timing theory continuous nursing,resistance training:Rehabilitation and mental health of caregivers and stroke patients with traumatic fractures

第25届中国控制与决策会议

作者： Zhang Xibin zong qun Zeng Fanlin School of Electrical and Automation Engineering Tianjin University School of science Tianjin University of Science & Technology

ISBN: (纸本)9781467355339

Aeroelastic modes are significant dynamic coupling in flexible hypersonic vehicle. This paper focus on the aeroelasitc modes in hypersonic vehicle model. The effects of elastic deformation of fuselage on the control angle and aerodynamic are analyzed. First, the analytical expressions of the changes of angle of attack and elevon deflection are presented.Then, Linear Piston Theory is used to evaluate the pressure distribution on the vehicle due to elastic deformation. The simulation shows that the aeroelastic modes of the fuselage are important as its deflection affects the angle of attack and elevon deflection. The aeroelastic modes can significantly influence the force and moment of the vehicle, and should be included in hypersonic vehicle modeling.

关键词： HSV aeroelastic modes angle of attack elevon deflection Linear Piston Theory

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World Journal of Clinical Cases 2022年第5期10卷 1508-1516页

作者： Ya-Li Shen zong-qun Zhang Li-Juan Zhu Jing-Hua Liu Department of Orthopedics Chengde Central HospitalChengde 067000Hebei ProvinceChina Department of Neurology Chengde Central HospitalChengde 067000Hebei ProvinceChina Department of Nursing Chengde Central HospitalChengde 067000Hebei ProvinceChina

BACKGROUND Stroke is the leading cause of adult lifelong disability worldwide.A stroke is an acute cerebrovascular disease with a variety of causes and corresponding clinical symptoms.Around 75%of surviving stroke patients experience impaired nerve function,and some suffer from traumatic fractures,which can lead to special care needs.AIM To determine the effect of timing theory continuous care,with resistance training,on the rehabilitation and mental health of caregivers and stroke patients with traumatic fractures.METHODS Between January 2017 to March 2021,we selected 100 hospital admissions with post-stroke hemiplegia complicated with a traumatic fracture.Two participant groups were created:(1)Control group:given resistance training;and(2)Observation group:given timing theory continuous care combined with resistance training.The degree of satisfaction and differences in bone and phosphorus metabolism indexes between the two groups were compared.The self-perceived burden scale(SPBS)and caregiver burden questionnaire were used to evaluate the psychological health of patients and caregivers.The Harris hip function score,ability of daily living(ADL)scale,and global quality of life questionnaire(GQOL-74)were used to evaluate hip function,ability of daily living,and quality of life.RESULTS Data were collected prior to and after intervention.Alkaline phosphatase(ALP),osteocalcin,and vitamin D3 in the observation group and control group increased after intervention(P0.05).The SPBS score of the observation group was lower and the ADL score was higher than the control group.The burden score was lower and the Harris hip function and GQOL-74 scores were higher than that of the control group(P<0.05).The observation group’s satisfaction rating was 94.00%,whic

关键词： Timing theory continuous nursing Resistance training Stroke Traumatic fracture Mental health

A distributed approach for lidar-based relative state estimation of multi-UAV in GPS-denied environments

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Chinese Journal of Aeronautics 2022年第1期35卷 59-69页

作者： Hongming SHEN qun zong Hanchen LU Xuewei ZHANG Bailing TIAN Lei HE School of Electrical and Information Engineering Ticmjin UniversityTianjin 300072China Institute of Field Engineering Army Engineering University of PLANanjing 210007China

In this paper,we present a distributed framework for the lidar-based relative state estimator which achieves highly accurate,real-time trajectory estimation of multiple Unmanned Aerial Vehicles(UAVs)in GPS-denied environments.The system builds atop a factor graph,and only on-board sensors and computing power are utilized.Benefiting from the keyframe strategy,each UAV performs relative state estimation individually and broadcasts very partial information without exchanging raw data.The complete system runs in real-time and is evaluated with three experiments in different environments.Experimental results show that the proposed distributed approach offers comparable performance with a centralized method in terms of accuracy and real-time performance.The flight test demonstrates that the proposed relative state estimation framework is able to be used for aggressive flights over 5 m/s.

关键词： Distributed relative state estimation GPS-denied environments Lidar-based perception Multi-UAV system Pose-graph optimization

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基于强化学习的飞行器自主规避决策方法

航空科学技术 2024年第6期35卷 96-103页

作者：窦立谦任梦圆张秀云宗群天津大学天津300072

考虑飞行器在执行任务过程中存在诸多不可预知的威胁或障碍,为保障飞行器的安全性,本文进行飞行器面向威胁目标的自主规避决策方法研究。首先综合考虑飞行器与威胁目标行为之间的相互影响,提出了基于深度长短期记忆(LSTM)神经网络的轨... 详细信息

考虑飞行器在执行任务过程中存在诸多不可预知的威胁或障碍,为保障飞行器的安全性,本文进行飞行器面向威胁目标的自主规避决策方法研究。首先综合考虑飞行器与威胁目标行为之间的相互影响,提出了基于深度长短期记忆(LSTM)神经网络的轨迹预测算法,实现对威胁目标未来轨迹的预测;然后结合预测信息构建拦截场景下规避机动的马尔可夫决策过程,设计了基于改进双延迟深度确定性策略梯度(P-TD3)的飞行器规避决策方法,以最大化规避过程的总收益为优化目标,实现飞行器自主规避决策。最后通过在虚拟仿真交互平台的试验验证,本文的决策方法提升了网络的收敛速度,具有84%的规避成功率,提高了飞行器对潜在威胁的成功规避概率,有利于增强飞行器的自主性与安全性。

关键词：高超声速飞行器强化学习双延迟深度确定性策略梯度自主规避机动决策