消除柔性系统残留振荡有限冲击控制研究

将时滞滤波器用于具有刚性模态的柔性系统中，可以抑制残留振荡，但容易产生冲击运动。为了降低运动冲击，对控制信号的时间变化率加以限制，设计有限冲击指令，同时将最小最大优化思想引入时滞滤波器的设计中，提出一种新型控制器——有限冲击时滞控制器。计算机仿真和试验结果表明，这一控制器能降低振荡的最大幅值．在一个振荡周期内有效抑制残留振荡;在系统参数变化范围内，控制器的复数零点能有效抵消系统的极点，因此有更强的鲁棒性；与常用的时滞滤波器相比，能抑制控制信号的高频成分，降低未建模动态激励和运动冲击。     

级联法设计时滞滤波器抑制双摆起重机货物摆动

当起重机的吊钩质量较大、货物质量较小,并且货物到吊钩的悬挂长度较大时,起重机货物摆动特性表现为双摆动力学特性,如果应用抑制单模态柔性系统振动的控制方法很难消除货物摆动。文中首先建立双摆龙门起重机货物摆动模型,分析货物摆动的频率和摆动幅值,然后通过级联法设计抑制多模态柔性系统振动的时滞滤波器,并应用于抑制双摆起重机货物的摆动,仿真结果验证了该时滞滤波器可有效抑制吊钩和货物的摆动,且保证了系统的响应速度。     

基于起升高度的最优输入整形器抑制桥式起重机载荷摆动

桥式起重机具有挠性机械环节一起升钢丝绳,其加、减速运动引起载荷摆动。为了消除这种摆动,根据桥式起重机起升高度的分布规律,基于载荷摆动幅值最小及优化时滞的思想设计最优输入整形器。仿真结果表明,在最优输入整形器的控制下,80／20t桥式起重机载荷最大摆动角度为0．036rad,与无输入整形器控制情况相比,载荷的最大摆角降低了95％。     

消除参数不确定柔性系统的残留振荡鲁棒控制

基于残留振荡能量最小的优化思想，在系统参数变化范围内设计鲁棒时滞滤波器。滤波器在柔性系统极点附近配置三重零点，使其对系统参数误差不敏感，具有很强的鲁棒性。将这一控制技术用于起重机的消摆控制系统中，可以有效抑制载荷的残留摆动。     

《机械工程学报》被EI收录论文目次(2007年第4期)

面向质量目标的尺寸链和统计公差设计方法................................................................................张宇杨慕升李晓沛(1)有限冲击最优时滞滤波器抑制起重机载荷残留摆动................................................................董明晓梅雪松郑康平等(7)线驱动拟人臂机器人逆向运动学分析......................................................................................陈伟海陈泉柱张建斌等(12)静压气体轴承静刚度的动态测试新方法........................................................…     

不确定柔性系统消除残留振荡的时滞滤波器设计

采用了零点配置方法来设计具有强鲁棒性的时滞滤波器,消除小阻尼不确定性系统的残留振荡。在系统极点附近配置多个滤波器零点,通过建立离散传递函数来得到时滞滤波器方程,设计简单,减少了计算量。该方法在起重机载荷防摆控制中得到了很好的应用,能够有效地消除载荷的摆动,对缆绳长度的变化具有很好的鲁棒性。     

塔式起重机载荷摆动特性研究

为了研究塔式起重机载荷摆动特性 ,寻找抑制载荷摆动的控制方法 ,本文基于非惯性参考系中质点相对运动动力学基本方程 ,建立塔式起重机同时进行变幅、回转、起升运动的情况下载荷摆动动力学模型 ,定量地分析载荷摆动的平衡状态 ,推导出线性化模型 ,对载荷摆动特性进行了计算机仿真。研究表明 :由于惯性力或离心力的作用 ,载荷摆动中心线发生倾斜 ,当载荷在倾斜的重力场内做空间摆运动 ,其摆动模型就是线性化模型 ,摆动中心线倾斜量就是平衡状态值     

起重机回转传动系统冲击载荷的磁流变半主动控制

以起重机回转支承传动系统为研究对象,提出了基于磁流变技术的起重机回转传动系统冲击载荷的控制策略和方法,即采用磁流变弹性体联轴器实现回转驱动装置与回转小齿轮的刚度和阻尼可控连接,实现了冲击载荷的振动抑制,建立了回转支承传动系统磁流变非线性动力学模型,求解了系统在定常及随机载荷激励作用下的动态响应,并以弹性体的变形量和联轴器的内外筒转角位移差值为控制对象,采用双态控制和PID控制两种半主动控制策略对冲击载荷的磁流变抑制效果进行了仿真研究。仿真结果表明:这两种半主动控制策略都能较好地抑制回转系统中的惯性冲击,并可改善起重机回转系统的运行平稳性。其中,双态控制对启制动时间的优化效果更佳,PID控制对冲击峰值和时间的综合优化能力更强。     

一种新的正幅值带尾部信号的时滞滤波器设计

针对带有零点的柔性系统,设计出一种新的正幅值约束的带尾部信号的时滞滤波器。该滤波器能够适应任意形式的系统输入,而且设计过程和期望的系统输出值无关,同时,对于参数时变系统,提出了新的鲁棒性约束条件,最后把设计的带尾部信号的时滞滤波器应用到桥式起重机的定位和防摆控制之中。仿真结果表明,该滤波器的应用能有效缩短起重机小车定位的调节时间,而且与基本的时滞滤波器级联控制时,可以有效消除负载的残留振荡,有利于作业效率的提高。     

起重机摆动控制系统的研究

为了实现起重机的自动化控制作业,同时有效提升起重机装卸作业效率,必须采用有效手段对起重机作业过程中的起吊物摆动进行控制.文中提出了基于起重机运行加速度控制的摆动控制方法,并构建了起重机摆动控制系统.首先建立了起重机搬运系统的三维模型,基于三维运动方程并结合实际的操作经验提出了一种有效的摆动控制方法.分析了摆动控制系统的特征参数,给出了摆动控制参数的具体计算方法,并进行了三维仿真与试验,仿真及试验结果验证了提出方法的有效性.     

风电行星齿轮系统变载荷激励动力学模型及其响应特性

针对风电行星齿轮系统变载变速的运行特点,通过分析系统构件为刚体和弹性体时的受力情况,应用运动合成原理,提出了变载荷激励下行星齿轮系统动力学模型的建立方法,并推导出系统的运动微分方程。在此基础上,分析了行星齿轮系统的内外部激励因素及其对系统动载荷和动载系数的影响机理。计算并分析了某MW级风电行星齿轮系统的动态响应,结果表明：系统的时变啮合刚度和时变轴承刚度主要影响响应频率的数值大小和系统的振动能量;外部变载荷使响应频率中存在明显的低频成分,并影响各阶振动间的能量分配;齿轮啮合力的动载系数主要受到外部变载荷的影响,而轴承力的动载系数同时受到系统内部激励和外部激励的影响。研究结果为风电齿轮箱的疲劳寿命分析和动态优化设计奠定了基础。     

Optimal control for the attitude stabilization of a rigid body using non-redundant parameters

This paper introduces a new class of an optimal stabilizing feedback control law for the attitude of motion of a rotating rigid body using rotors system which rotate with the help of electrical motors that are mounted on this body. The control moments that can be generated by the rotors system are derived as non-linear terms of new parameterizations of the rotation group. The stabilizing properties of the proposed control law are proved by using the optimal Liapunov function. Some known results on the control of the rigid body motion are generalized and other new results are obtained. Finally, numerical examples demonstrate the theoretical results.     

Trajectory planning for overhead crane by trolley acceleration shaping

This paper proposes a novel off-line trolley trajectory planning method for underactuated overhead cranes. The proposed technique is feasible and efficient for overhead crane operation. Dynamic coupling between trolley motion and payload swing was successfully exploited using a staircase form of trolley acceleration. The payload swings in the constant velocity phase were efficiently suppressed and the trolley reached the desired position using this technique. The reasonable number of stairs can be determined by evaluating the residual oscillation amplitude according to the number of stairs and variation in the natural frequency of the pendulum. The proposed approach was first simulated from the kinematics viewpoint to verify the validity of the trolley trajectory and the swing angle of the payload. The proposed approach was then combined with the dynamics of the overall crane, wherein the robust sliding mode controller was applied to ensure that the trolley tracks the designed trajectory. The numerical simulation results demonstrated superior performance and robustness against parameter uncertainties of the proposed method. The proposed method exhibited potential for application in the control of underactuated systems, such as overhead cranes, single-link flexible-joint manipulators, and flexible Cartesian manipulators.     

基于FIR优化滤波的旋转高频信号注入法及其应用

针对传统旋转高频信号注入法中信号处理精度低、延时时间长及过程复杂等缺陷,提出一种基于有限冲激响应(finite impulse response,FIR)优化滤波的改进旋转高频信号注入法.该方法采用等纹波最佳逼近FIR滤波器提取高频电流信号,实现高频电流信号提取误差最小.通过对高频电流作外差处理,提取转子位置误差信号,省去旋转高频信号注入法中的同步轴系滤波单元,降低系统的复杂性.通过线性相位补偿,实现转子速度与位置估计最小延迟.构建无轴承永磁同步电机无速度传感器矢量控制平台,验证算法的有效性.仿真实验结果表明:通过离线优化设计FIR滤波器及线性相位补偿,该方法在全速范围内能够准确估计转子的位置与速度,与卡尔曼滤波相比,其估计精度更高,鲁棒性更强.     

Dynamic responses of hydraulic mobile crane with consideration of the drive system

The dynamic behaviour of mobile cranes is determined not only by the steel structures and the external loads but also by the drive- and control systems. In today’s dynamic calculation of mobile cranes, the drive systems are modelled through the method of “kinematic forcing” or by measurements for outputs of the drive system. To improve this situation, a new method for dynamic calculation of mobile cranes has been developed. In this method, the flexible multibody model of the structure will be coupled with the model of the drive system. In that way the elastic deformation, the rigid body motion of structures and the dynamic behaviour of the drive system can be determined in an integrated model. The calculation method has been realized for a hydraulic mobile crane. In addition to the structural elements, the mathematical modelling for hydraulic drive- and control system is described. The crane rotating simulation for arbitrary working conditions has been carried out. As a result, a more exact representation of dynamic behaviour, not only for the crane structure, but also for the drive system is achieved.     

Characterisation of optimal human driver model and stability of a tractor-semitrailer vehicle system with time delay

In this paper, a vehicle/driver close-loop system is studied in order to characterise the inherent model parameters of an optimal human controller for a regulation task (e.g. stabilisation after a wind gust) in articulated vehicle motions. The tractor-semitrailer vehicle model consists of two articulated rigid bodies moving on a horizontal plane with a constant forward speed. The driver establishes his steering control through a time-delayed feedback from current vehicle states with respect to the desired motion. Identification of driver model parameters is achieved through an optimal control approach. The stability of the delayed dynamical system is also studied using a numerical method by computing the eigenvalues near the imaginary axis.     

Laboratory-scale experiments on wind turbine nacelle movement estimation

The effect of nacelle motion should be considered when calculating the wind speed relative to the wind turbine structure, which is essential in wind turbine control and performance testing. A Kalman filter approach is applied to estimate the nacelle motion of a wind turbine. Information from several accelerometers and strain gauges which are installed on the wind turbine tower is combined with the Kalman filter. An optimization algorithm is used to choose the optimal locations for strain gauge and accelerometer installation. A laboratory-scale experimental rig which mimics the tower and nacelle of the wind turbine is constructed to evaluate the performance of the proposed estimator algorithm. The usefulness of the proposed algorithm is validated by these laboratory-scale experimental results.     

两自由度单边刚性约束碰撞系统的混沌演化

建立了一类两自由度单边刚性约束碰撞系统的力学模型,通过理论分析和数值仿真结合,推导了系统周期运动的解析解和Poincaré映射,分析了系统周期运动的稳定性及系统在适当参数下发生分岔与混沌的现象,为实际动力学系统优化提供了理论依据。     

自由浮动柔性双臂空间机器人系统的动力学控制

基于假设模态法对柔性连杆的变形进行近似描述,采用拉格朗日方程分析柔性臂的动力学关系,忽略高阶弹性振动模态,根据柔性双臂和物体的动力学方程、末端约束关系以及系统的动量守恒原理,推导一种自由浮动柔性双臂空间机器人闭链系统的动力学模型。针对系统柔性状态的高频特征,采用奇异摄动法将该系统模型分离为慢变和快变两个子系统,对二者分别采用滑模变结构控制和非线性PD控制,保证刚性、柔性状态输出达到要求,由此得到的组合控制使得系统能较好地跟踪期望的轨迹,抑制弹性振动,并减小对本体运动的影响,内力、内力矩均能平稳跟踪期望值。最后进行数字仿真,验证上述方法的有效性。