摘要：Stabilization of the constrained switched nonlinear systems is an attractive research subject. Predictive control can handle variable constraints well and make the system stable. Its stability is typically based on an assumption of initial feasibility of the optimization problem; however the set of initial conditions, starting from where a given predictive formulation is guaranteed to be feasible, is not explicitly characterized. In this paper, a hybrid predictive control method is proposed for a class of switched nonlinear systems with input constraints and un-measurable states. The main idea is to design a mixed controller using Lyapunov functions and a state observer, which switches appropriately between a bounded feedback controller and a predictive controller, and to give an explicitly characterized set of initial conditions to stabilize each closed-loop subsystem. For the whole switched nonlinear system, a suitable switched law based on the state estimation is designed to orchestrate the transitions between the consistituent modes and their respective controllers, and to ensure the whole closed-loop system's stability. The simulation results for a chemical process show the validity of the controller proposed in this paper.

摘要：Many girls do not engage in sufficient physical activity (PA). Dance is a popular form of PA among UKsecondary school-aged girls and extracurricular dance programs delivered by dance specialists may provide an alternative way to increase PA amongst girls aged 11 - 12. The purpose of this study was to explore the views of physical education and dance teachers on the structure, content and delivery of an extra-curricular dance-based PA intervention for adolescent girls. Methods: Semi-structured qualitative interviews were conducted with eleven physical education teachers and eleven dance teachers, and were analyzed using thematic analysis. Results: Themes identified addressed key logistical and content/delivery-based factors to be considered when designing a dance-based PA intervention. Logistical factors included optimizing participant recruitment and aligning external providers with school behavior management policies. Content/delivery factors focused on teacher-student rapport, facilitating dance competence, and balancing teacher and student-led time. Conclusions: This formative study highlighted that an extra-curricular dance-based PA intervention would be welcomed inUK schools. A number of considerations central to the design and delivery of such a program were identified from key user groups which can be used to inform the development of school-based dance (and non-dance) interventions aimed at increasing PA amongst adolescent girls.

摘要：有约束切换非线性系统的稳定控制是一个重要的研究问题.通常的预测控制方法可以很好的处理约束问题并使得系统稳定,但一般首先假设其中的优化问题初始可行,而对于初始稳定区域并没有具体的描述.本文针对一类输入变量受约束且状态不可测的非线性切换系统,提出了一种混合非线性预测控制方案.其主要思想是:利用李亚普诺夫函数和状态观测器,设计在预测控制器和有界反馈控制器之间适当切换的混杂控制器,以得到初始稳定区域的描述并使得子系统闭环稳定;对整个切换系统,基于状态估计,设计在各组件间平稳切换的切换律,以保证整个闭环系统的渐近稳定性.最后通过对一个化工过程实例进行仿真,验证了本文所提控制器的有效性.

摘要：为了提高基于光度立体法的物体三维表面重建精度,研究了几种常用三维表面重建算法的适用范围。介绍了几种常用重建算法(变分法、金字塔法、代数法)的基本原理及求解方法,指出了表面方向梯度的求解准确度是三维表面重建过程中的难点。在此基础上建立了朗伯半球体模型和实际拍摄的玻璃灯罩,从重建速度、重建精度等方面对几种算法进行了比较和评价。最后通过实验模拟和算法性能评价,表明了常用算法的重建精确度有限,并且对三维重建今后的研究进行了展望。