To reduce the roll movement of an air spring passenger car, an active anti-roll system is developed, which is constructed with hydraulic and pneumatic units to change spring rate during cornering. For the comparing re...To reduce the roll movement of an air spring passenger car, an active anti-roll system is developed, which is constructed with hydraulic and pneumatic units to change spring rate during cornering. For the comparing research between the passive and active system, a two-track vehicle model and a co-simulation model of air spring system are built. For the simulation research on the linear movement of the actuator, a mathematical model is considered as dynamical subsystem in the co-simulation model. To active control the roll angle of vehicle body, a sliding-mode controller with optimized control parameters for the test vehicle is introduced into the model. The characteristics of sliding-mode controller is discussed and the validation of active antiroll control is proved by comparison with other control methods. The results show that the roll angle of air spring vehicle is reduced obviously with the active anti-roll actuator in comparison with that of the passive system. Compared with other control methods, sliding-mode controller has an advantage of shortest switching times, which leads to a longer lifetime of actuator and valves.展开更多
The mass production of primed electronics can be achieved by roll-to-roll（R2R） printing system, so highly accurate web tension is required that can minimize the register error and keep the thickness and roughness of...The mass production of primed electronics can be achieved by roll-to-roll（R2R） printing system, so highly accurate web tension is required that can minimize the register error and keep the thickness and roughness of printed devices in limits. The web tension of a R2R system is regulated by the use of integrated load cells and active dancer system for printed electronics applications using decentralized multi-input-single-output（MISO） regularized variable learning rate backpropagation artificial neural networks. The active dancer system is used before printing system to reduce disturbances in the web tension of process span. The classical PID control result in tension spikes with the change in roll diameter of winder and unwinder rolls. The presence of dancer in R2R system shows that improved web tension control in printing span and the web tension can be enhanced from 3.75 N to 4.75 N. The overshoot of system is less than ±2.5 N and steady state error is within ± 1 N where load cells have a signal noise of ±0.7 N. The integration of load cells and active dancer with self-adapting neural network control provide a solution to the web tension control of multispan roll-to-roll system.展开更多
Ultrasonic surface rolling process(USRP)is one of the effective mechanical surface enhancement techniques.During the USRP,unstable static force will easily do harm to the surface quality.In order to achieve a higher s...Ultrasonic surface rolling process(USRP)is one of the effective mechanical surface enhancement techniques.During the USRP,unstable static force will easily do harm to the surface quality.In order to achieve a higher surface quality on the part with a curved surface,an active and passive compliant USRP system has been developed.The compliant USRP tool can produce the natural obedience deformation along the part surface.Force control based on the fuzzy Proportional-integral-derivative(PID)method is then designed to maintain the static force during the USRP.Experiments have been performed on a real aero-engine blade with curved surface.It is proved that the deigned active and passive compliant USRP system can significantly reduce the force variation from 42.2 N to 4.2 N,and achieve a uniform surface quality after processing.展开更多
针对可旋转翼式弹道修正组件滚转通道控制中存在的未建模摩擦干扰、参数不确定性和外部随机干扰造成的复合扰动问题,提出一种基于扩张状态观测器(extended state observer, ESO)的滑模控制方法。首先建立弹道修正组件滚转通道模型,将动...针对可旋转翼式弹道修正组件滚转通道控制中存在的未建模摩擦干扰、参数不确定性和外部随机干扰造成的复合扰动问题,提出一种基于扩张状态观测器(extended state observer, ESO)的滑模控制方法。首先建立弹道修正组件滚转通道模型,将动力学模型中存在的外部干扰、未建模摩擦干扰和参数摄动整合为复合干扰,然后设计ESO对修正组件滚转通道模型中难以直接测定的状态变量以及复合干扰进行估计,并基于估计值结合滑模控制理论设计滚转通道控制器,实现对滚转角指令的精确跟踪。综合考虑ESO和滑模控制器构成的闭环控制系统,利用Lyaponov稳定性理论证明了所设计的闭环控制系统的稳定性。最后,通过仿真实验分析,证明所设计的修正组件滚转通道控制器,对滚转角指令的瞬态响应和稳态性能优异,同时可以有效抑制系统复合扰动,具备较强的鲁棒性。展开更多
针对重型半挂车的侧倾稳定性问题,建立了八自由度的车辆模型,并以LQR主动侧倾控制方法为基础,提出了一种基于回路传输恢复技术(Loop Transfer Recovery:LTR)的LQG主动侧倾控制算法。设计各个车速下LQG/LTR局部状态反馈控制器,并进行了...针对重型半挂车的侧倾稳定性问题,建立了八自由度的车辆模型,并以LQR主动侧倾控制方法为基础,提出了一种基于回路传输恢复技术(Loop Transfer Recovery:LTR)的LQG主动侧倾控制算法。设计各个车速下LQG/LTR局部状态反馈控制器,并进行了阶跃转向工况下车辆的仿真。仿真结果表明:LQG/LTR主动侧倾控制算法有效提高了重型半挂车的侧倾稳定性。展开更多
重型半挂车极易发生侧翻事故,提高其侧倾稳定性可以减少事故发生和人员财产损失。针对重型半挂车侧倾稳定性问题,建立车速可变的8自由度动力学模型。在回路传输恢复技术(Loop transfer recovery,LTR)的线性二次高斯(Linear quadratic gu...重型半挂车极易发生侧翻事故,提高其侧倾稳定性可以减少事故发生和人员财产损失。针对重型半挂车侧倾稳定性问题,建立车速可变的8自由度动力学模型。在回路传输恢复技术(Loop transfer recovery,LTR)的线性二次高斯(Linear quadratic guass,LQG)控制方法基础上,建立全局增度调度控制的全状态反馈控制器,使LQG/LTR局部状态反馈控制器在不同车速下均能对车辆实施最优主动侧倾控制,从而实现在噪声干扰下对重型半挂车的主动侧倾控制。进行变车速阶跃转向工况下的车辆仿真,对比分析主动控制前后的重型半挂车标准横向载荷转移等参数。车辆仿真结果表明,LQG/LTR方法具有良好的抑制干扰噪声的能力,可使系统具有较好的鲁棒性和稳定性。与被动式车辆相比,变车速的全局增益调度控制算法能有效提高重型半挂车的侧倾稳定性。展开更多
基金Sponsored by German Academic Exchange Service(Deutsche Akademische Austauschdienst)
文摘To reduce the roll movement of an air spring passenger car, an active anti-roll system is developed, which is constructed with hydraulic and pneumatic units to change spring rate during cornering. For the comparing research between the passive and active system, a two-track vehicle model and a co-simulation model of air spring system are built. For the simulation research on the linear movement of the actuator, a mathematical model is considered as dynamical subsystem in the co-simulation model. To active control the roll angle of vehicle body, a sliding-mode controller with optimized control parameters for the test vehicle is introduced into the model. The characteristics of sliding-mode controller is discussed and the validation of active antiroll control is proved by comparison with other control methods. The results show that the roll angle of air spring vehicle is reduced obviously with the active anti-roll actuator in comparison with that of the passive system. Compared with other control methods, sliding-mode controller has an advantage of shortest switching times, which leads to a longer lifetime of actuator and valves.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF),Ministry of Education,Science and Technology,Korea(Grant No.2010-0026163)Strategy Technology Development Project,Ministry of Knowledge Economy,Korea(Grant No.10032149)
文摘The mass production of primed electronics can be achieved by roll-to-roll（R2R） printing system, so highly accurate web tension is required that can minimize the register error and keep the thickness and roughness of printed devices in limits. The web tension of a R2R system is regulated by the use of integrated load cells and active dancer system for printed electronics applications using decentralized multi-input-single-output（MISO） regularized variable learning rate backpropagation artificial neural networks. The active dancer system is used before printing system to reduce disturbances in the web tension of process span. The classical PID control result in tension spikes with the change in roll diameter of winder and unwinder rolls. The presence of dancer in R2R system shows that improved web tension control in printing span and the web tension can be enhanced from 3.75 N to 4.75 N. The overshoot of system is less than ±2.5 N and steady state error is within ± 1 N where load cells have a signal noise of ±0.7 N. The integration of load cells and active dancer with self-adapting neural network control provide a solution to the web tension control of multispan roll-to-roll system.
基金sponsored by the National Natural Science Foundation of China(No.51725503,No.51975214)Innovation Program of Shanghai Municipal Education Commission(2019-01-07-00-02-E00068)+2 种基金support by Shanghai Technology Innovation Program of SHEITC(CXY-2015-001)Fok Ying Tung Education FoundationYoung Program of Yangtze River Scholars。
文摘Ultrasonic surface rolling process(USRP)is one of the effective mechanical surface enhancement techniques.During the USRP,unstable static force will easily do harm to the surface quality.In order to achieve a higher surface quality on the part with a curved surface,an active and passive compliant USRP system has been developed.The compliant USRP tool can produce the natural obedience deformation along the part surface.Force control based on the fuzzy Proportional-integral-derivative(PID)method is then designed to maintain the static force during the USRP.Experiments have been performed on a real aero-engine blade with curved surface.It is proved that the deigned active and passive compliant USRP system can significantly reduce the force variation from 42.2 N to 4.2 N,and achieve a uniform surface quality after processing.
文摘针对可旋转翼式弹道修正组件滚转通道控制中存在的未建模摩擦干扰、参数不确定性和外部随机干扰造成的复合扰动问题,提出一种基于扩张状态观测器(extended state observer, ESO)的滑模控制方法。首先建立弹道修正组件滚转通道模型,将动力学模型中存在的外部干扰、未建模摩擦干扰和参数摄动整合为复合干扰,然后设计ESO对修正组件滚转通道模型中难以直接测定的状态变量以及复合干扰进行估计,并基于估计值结合滑模控制理论设计滚转通道控制器,实现对滚转角指令的精确跟踪。综合考虑ESO和滑模控制器构成的闭环控制系统,利用Lyaponov稳定性理论证明了所设计的闭环控制系统的稳定性。最后,通过仿真实验分析,证明所设计的修正组件滚转通道控制器,对滚转角指令的瞬态响应和稳态性能优异,同时可以有效抑制系统复合扰动,具备较强的鲁棒性。
文摘针对重型半挂车的侧倾稳定性问题,建立了八自由度的车辆模型,并以LQR主动侧倾控制方法为基础,提出了一种基于回路传输恢复技术(Loop Transfer Recovery:LTR)的LQG主动侧倾控制算法。设计各个车速下LQG/LTR局部状态反馈控制器,并进行了阶跃转向工况下车辆的仿真。仿真结果表明:LQG/LTR主动侧倾控制算法有效提高了重型半挂车的侧倾稳定性。
文摘重型半挂车极易发生侧翻事故,提高其侧倾稳定性可以减少事故发生和人员财产损失。针对重型半挂车侧倾稳定性问题,建立车速可变的8自由度动力学模型。在回路传输恢复技术(Loop transfer recovery,LTR)的线性二次高斯(Linear quadratic guass,LQG)控制方法基础上,建立全局增度调度控制的全状态反馈控制器,使LQG/LTR局部状态反馈控制器在不同车速下均能对车辆实施最优主动侧倾控制,从而实现在噪声干扰下对重型半挂车的主动侧倾控制。进行变车速阶跃转向工况下的车辆仿真,对比分析主动控制前后的重型半挂车标准横向载荷转移等参数。车辆仿真结果表明,LQG/LTR方法具有良好的抑制干扰噪声的能力,可使系统具有较好的鲁棒性和稳定性。与被动式车辆相比,变车速的全局增益调度控制算法能有效提高重型半挂车的侧倾稳定性。
