Impact dynamics of multi-rigid-body systems with joint friction is considered. Based on the traditional approximate assumption dealing with impact problem, a general numerical method called the sliding state stepping ...Impact dynamics of multi-rigid-body systems with joint friction is considered. Based on the traditional approximate assumption dealing with impact problem, a general numerical method called the sliding state stepping algorithm is introduced. This method can avoid difficulties in solving differential equations with variable scale and its result can avoid energy inconsistency before and after impact from considering complexily of tangential sliding mode. An example is given to describe details using this algorithm.展开更多
For input saturated Hammerstein systems, the two-step predictive control strategy is adopted. The first step calculates the desired intermediate variable applying unconstrained linear modal and predictive control. The...For input saturated Hammerstein systems, the two-step predictive control strategy is adopted. The first step calculates the desired intermediate variable applying unconstrained linear modal and predictive control. The second step obtains the real-time control action by solving algebraic equation and desaturation. The case of immeasurable state is considered where the observer gain matrix is solved by Sylvester equation. The sufficient closed-loop stability condition is given and the designing and tuning algorithm for the domain of attraction is proposed. The theoretical results are validated by an example.展开更多
An aperture design technique using multi-step amplitude quantization for two-dimensional solid-state active phased arrays to achieve low sidelobe is described. It can be applied to antennas with arbitrary complex aper...An aperture design technique using multi-step amplitude quantization for two-dimensional solid-state active phased arrays to achieve low sidelobe is described. It can be applied to antennas with arbitrary complex aperture. Also, the gain drop and sidelobe degradation due to random amplitude and phase errors and element (or T/R module) failures are investigated.展开更多
有限状态机(FSM)技术是任务调度的核心,通过分析STEP-NC数据流和STEP-NC程序的数据模型,提出FSM的STEP-NC信息提取系统实现方案。把信息提取系统分为节点-实体模块、词法分析模块、实体-实例模块、检索模块和特征重构模块五个模块,在创...有限状态机(FSM)技术是任务调度的核心,通过分析STEP-NC数据流和STEP-NC程序的数据模型,提出FSM的STEP-NC信息提取系统实现方案。把信息提取系统分为节点-实体模块、词法分析模块、实体-实例模块、检索模块和特征重构模块五个模块,在创建节点和字典实体数据的基础上,对基于FSM的五个模块的内部任务处理进行研究,最终得到三维实体几何数据。在Visual Studio 2005平台上开发信息提取系统,并通过实例对其有效性进行验证。展开更多
The problem of global stabilization by state feedback for a class of time-delay nonlinear system is considered. By constructing the appropriate Lyapunov-Krasovskii functionals (LKF) and using the backstepping design, ...The problem of global stabilization by state feedback for a class of time-delay nonlinear system is considered. By constructing the appropriate Lyapunov-Krasovskii functionals (LKF) and using the backstepping design, a linear state feedback controller making the closed-loop system globally asymptotically stable is constructed.展开更多
针对一类四旋翼飞行器吊挂飞行系统的负载摆动抑制和轨迹跟踪精确控制的问题,考虑系统存在未知外界扰动和模型动态不确定的情况,提出一种基于扩张状态观测器(Extended state observer, ESO)的吊挂负载摆动抑制的非线性轨迹跟踪控制方法...针对一类四旋翼飞行器吊挂飞行系统的负载摆动抑制和轨迹跟踪精确控制的问题,考虑系统存在未知外界扰动和模型动态不确定的情况,提出一种基于扩张状态观测器(Extended state observer, ESO)的吊挂负载摆动抑制的非线性轨迹跟踪控制方法.将四旋翼吊挂飞行系统分解为姿态、位置和负载摆动控制三个动态子系统,分别设计非线性控制器实现欠驱动约束下的解耦控制;设计一种扩张状态观测器,用以估计和补偿四旋翼与吊挂负载耦合飞行的未知外界扰动与模型动态不确定性,并验证了闭环系统的稳定性,跟踪误差及吊挂负载摆动所有信号的一致最终有界.最后,利用Quanser公司的Qball2飞行器进行三维空间螺旋轨迹的跟踪控制,仿真结果验证了未知干扰下基于扩张状态观测器的四旋翼吊挂飞行非线性控制的有效性和优越性,实现了四旋翼吊挂系统轨迹跟踪的精确控制和飞行过程中负载摆动的快速抑制.展开更多
基金the National Natural Science Foundation of China(No.10532050)the Na-tional Science Fund for Distinguished Young Scholars(No.10625211)the Science Development Foundation of Shandong University of Science and Techonogy(No.05g017)
文摘Impact dynamics of multi-rigid-body systems with joint friction is considered. Based on the traditional approximate assumption dealing with impact problem, a general numerical method called the sliding state stepping algorithm is introduced. This method can avoid difficulties in solving differential equations with variable scale and its result can avoid energy inconsistency before and after impact from considering complexily of tangential sliding mode. An example is given to describe details using this algorithm.
文摘For input saturated Hammerstein systems, the two-step predictive control strategy is adopted. The first step calculates the desired intermediate variable applying unconstrained linear modal and predictive control. The second step obtains the real-time control action by solving algebraic equation and desaturation. The case of immeasurable state is considered where the observer gain matrix is solved by Sylvester equation. The sufficient closed-loop stability condition is given and the designing and tuning algorithm for the domain of attraction is proposed. The theoretical results are validated by an example.
文摘An aperture design technique using multi-step amplitude quantization for two-dimensional solid-state active phased arrays to achieve low sidelobe is described. It can be applied to antennas with arbitrary complex aperture. Also, the gain drop and sidelobe degradation due to random amplitude and phase errors and element (or T/R module) failures are investigated.
文摘有限状态机(FSM)技术是任务调度的核心,通过分析STEP-NC数据流和STEP-NC程序的数据模型,提出FSM的STEP-NC信息提取系统实现方案。把信息提取系统分为节点-实体模块、词法分析模块、实体-实例模块、检索模块和特征重构模块五个模块,在创建节点和字典实体数据的基础上,对基于FSM的五个模块的内部任务处理进行研究,最终得到三维实体几何数据。在Visual Studio 2005平台上开发信息提取系统,并通过实例对其有效性进行验证。
基金Supported by the "973" Project of P. R. China (G1998020300)
文摘The problem of global stabilization by state feedback for a class of time-delay nonlinear system is considered. By constructing the appropriate Lyapunov-Krasovskii functionals (LKF) and using the backstepping design, a linear state feedback controller making the closed-loop system globally asymptotically stable is constructed.
文摘针对一类四旋翼飞行器吊挂飞行系统的负载摆动抑制和轨迹跟踪精确控制的问题,考虑系统存在未知外界扰动和模型动态不确定的情况,提出一种基于扩张状态观测器(Extended state observer, ESO)的吊挂负载摆动抑制的非线性轨迹跟踪控制方法.将四旋翼吊挂飞行系统分解为姿态、位置和负载摆动控制三个动态子系统,分别设计非线性控制器实现欠驱动约束下的解耦控制;设计一种扩张状态观测器,用以估计和补偿四旋翼与吊挂负载耦合飞行的未知外界扰动与模型动态不确定性,并验证了闭环系统的稳定性,跟踪误差及吊挂负载摆动所有信号的一致最终有界.最后,利用Quanser公司的Qball2飞行器进行三维空间螺旋轨迹的跟踪控制,仿真结果验证了未知干扰下基于扩张状态观测器的四旋翼吊挂飞行非线性控制的有效性和优越性,实现了四旋翼吊挂系统轨迹跟踪的精确控制和飞行过程中负载摆动的快速抑制.
