Multilevel adaptive control of nonlinear interconnected systems

This paper presents an adaptive backstepping-based multilevel approach for the first time to control nonlinear interconnected systems with unknown parameters. The system consists of a nonlinear controller at the first level to neutralize the interaction terms, and some adaptive controllers at the second level, in which the gains are optimally tuned using genetic algorithm. The presented scheme can be used in systems with strong couplings where completely ignoring the interactions leads to problems in performance or stability. In order to test the suitability of the method, two case studies are provided: the uncertain double and triple coupled inverted pendulums connected by springs with unknown parameters. The simulation results show that the method is capable of controlling the system effectively, in both regulation and tracking tasks.     

Inverted pendulum stabilization: Characterization of codimension-three triple zero bifurcation via multiple delayed proportional gains

The paper considers the problem of stabilization of systems possessing a multiple zero eigenvalue at the origin. The controller that we propose, uses multiple delayed measurements instead of derivative terms. Doing so, we increase the performances of the closed loop in presence of system uncertainties and/or noisy measurements. The problem formulation and the analysis is presented through a classical engineering problem which is the stabilization of an inverted pendulum on a cart moving horizontally. On one hand, we perform a nonlinear analysis of the center dynamics described by a three dimensional system of ordinary differential equations with a codimension-three triple zero bifurcation. On the other hand, we present the complementary stability analysis of the corresponding linear time invariant system with two delays describing the behavior around the equilibrium. The aim of this analysis is to characterize the possible local bifurcations. Finally, the proposed control scheme is numerically illustrated and discussed.     

深井软岩巷道围岩控制技术研究

深井软岩巷道支护是目前矿压界的支护难题之一。依据现场工程实践,通过设计合理有效的支护方案且对巷道支护参数进行优化。采用以注浆锚杆与注浆锚索为主的锚注联合支护巷道两帮,并施加以底板反底拱,及时监测矿压变化规律。结果表明,注浆锚杆与锚索在深井软岩巷道围岩控制中可以起到良好的效果,巷道反底拱能够有效控制深井巷道底鼓。     

Study on self‐adjustable variable pendulum tuned mass damper

Pendulum tuned mass damper (PTMD) is usually used to control the horizontal vibration of a tall building. However, traditional PTMD is highly sensitive to frequency deviation and difficult to adjust its frequency. In order to improve this problem of traditional PTMD and protect a tall building more effectively, a novel PTMD, called self‐adjustable variable pendulum tuned mass damper (SAVP‐TMD), is proposed in this paper. On the basis of the acceleration ratio between TMD and primary structure, the SAVP‐TMD can retune itself by varying the length of the pendulum according to the improved acceleration ratio‐based adjustment algorithm. PTMD and primary structural accelerations are obtained from two accelerometers respectively, and the acceleration ratio is calculated in a microcontroller, then, the stepper motor will adjust the pendulum under the guidance of the microcontroller under a specific harmonic excitation. The improved acceleration ratio‐based adjustment algorithm is proposed and compared to solve the nonconvergent retuning problem. The SAVP‐TMD can be regarded as a passive damper including a frequency adjustment device. A single‐degree‐of‐freedom structure model is used to verify the effectiveness of SAVP‐TMD through both experimental study and numerical simulation. In order to further verify the effect of SAVP‐TMD in the MDOF structure, a five‐storey structure coupled with an SAVP‐TMD is proposed as a case study. The results of experiment, simulation, and case study all show that SAVP‐TMD can retune itself to the primary structural dominant frequency robustly, and the retuned PTMD has a better vibration control effect than the mistuned one.     

慈溪市区域排水系统技术方案分析

为解决慈溪市域范围1市17镇的污水出路问题,在慈溪市污水治理一期工程中拟采用区域排水系统方式.通过对区域排水系统的总体布置、二级处理和深度处理的技术经济分析,最终确定区域排水系统采用三大污水收集系统、三座污水处理厂、分点进水倒置A/A/O脱氮除磷工艺以及人工湿地深度处理工艺的方案.     

浅析倒置式屋面设计中的几个问题

就倒置式屋面在构造设计中普遍存在的一些问题，从压置层的设计、排水设计、防水层设计、保温层设计等方面作了探讨，以利倒置式屋面在工程中的广泛应用。     

倒置式屋面新型隔热防水技术

结合倒置式施工特点 ,介绍了一种利用自行研制的防水隔热块和设置预防水层进行建筑屋面的新型隔热防水工程施工方法。该技术不仅保障了屋面具有优良的保温隔热功能 ,而且隔热块本身的自防水性和设置的预防水层构成复合防水能有效地保证屋面的抗渗漏性 ,有很好的市场推广应用价值和开发前景。     

一种公路路堤施工方法探讨

结合工程实例，对填石路堤的施工工艺进行了介绍，并对浸水路堤路基横断面，反滤层及塑料土工格栅，路基坡面地表处理等填石路堤施工中的一些问题进行了阐述，以提高路基压实度，保证了路面的正常使用。     

XPS在倒置式保温屋面中的应用

本文通过阐述XPS的优异性能,论述了XPS在保温屋面中的作用,XPS倒置式保温屋面的优越性,施工方法以及质量保证措施,以期对XPS在倒置式保温屋面中的应用提供有益的帮助。     

倒置式屋面作法简析及施工技术要点

以传统屋面作法存在的不足为基础，分析介绍了倒置式屋面作法存在的优点及缺点，以充分发挥倒置式屋面的整体功效为出发点，介绍了倒置式屋面各施工工序以及面层施工的技术要点及注意事项。