A novel ADRC‑based design for a kind of fexible aerocraft

The paper presents a novel control design, which is based on the idea of active disturbance rejection control (ADRC), for a kind of fexible aerocraft whose controlled variable cannot be measured directly. Since the original frame of ADRC cannot be directly applied, the paper puts forward a new extended state observer (ESO) and the corresponding ADRC law. In order to assign the poles of the closed-loop system to ideal positions such that the vibration can be quickly suppressed, an elastic damping term is added into feedback law. The advantages of the new ESO for efectively estimating both the rigid mode and elastic mode from the measurements are discussed. Moreover, the analysis on the stability, the relative stability and the steady state of the closed-loop system is given. Finally, the efectiveness and robustness of the proposed ADRC are verifed by simulations.     

Energy-efficient adaptive sensor scheduling for target tracking in wireless sensor networks

Sensor scheduling is essential to collaborative target tracking in wireless sensor networks (WSNs). In the existing works for target tracking in WSNs, such as the information-driven sensor query (IDSQ), the tasking sensors are scheduled to maximize the information gain while minimizing the resource cost based on the uniform sampling intervals, ignoring the changing of the target dynamics and the specific desirable tracking goals. This paper proposes a novel energyefficient adaptive sensor scheduling approach that jointly selects tasking sensors and determines their associated sampling intervals according to the predicted tracking accuracy and tracking energy cost. At each time step, the sensors are scheduled in alternative tracking mode, namely, the fast tracking mode with smallest sampling interval or the tracking maintenance mode with larger sampling interval, according to a specified tracking error threshold. The approach employs an extended Kalman filter (EKF)-based estimation technique to predict the tracking accuracy and adopts an energy consumption model to predict the energy cost. Simulation results demonstrate that, compared to a non-adaptive sensor scheduling approach, the proposed approach can save energy cost significantly without degrading the tracking accuracy.     

A stable multimodel scheme control for the regulation of the transient behavior of a tunnel-diode trigger circuit

A multimodel scheme is designed for a triggering tunnel-diode circuit. The scheme improves the transient behavior during the transition time period after switching from a stable system equilibrium point to another one which is known as a triggering process. Each model is obtained by a linearization of the circuit near an equilibrium point. Moreover, each of these models can be described as a combination of two other transfer functions describing the linearized plant behavior near two different equilibrium points. The scheme chooses online the model with the best tracking performance in order to generate the control law. Different reference transfer functions are proposed with the aim of generating the desired transient in the triggering process. Some simulations show the usefulness of this scheme.     

印度兰吉特大坝的泥沙管理

印度兰吉特河(Rangit)是提斯塔河(Teesta)的主要支流,位于东喜马拉雅地区。兰吉特水电站装机60 MW,于2000年2月投入运行。每年5~9月汛期之间,兰吉特河输沙量巨大,2006年,该电站发生水淹厂房事故。     

Built in electric field boosted photocatalytic performance in a ferroelectric layered material SrBi2Ta2O9 with oriented facets: Charge separation and mechanism insights

Antibiotics have received increasing attention due to their potential adverse effects on aquatic life and human health. How to efficiently degrade them into harmless substances is a challenging subject. Ferroelectric materials with a built-in electric field can offer a strong separation ability for the photoinducedcharge pairs and are now found to be used as photocatalysts. Herein, a series of different morphologies of SrBi₂Ta₂O₉ ferroelectric photocatalysts with...     

Coherent H∞Control for Linear Quantum Systems With Uncertainties in the Interaction Hamiltonian

This work conducts robust H^∞analysis for a class of quantum systems subject to perturbations in the interaction Hamiltonian.A necessary and sufficient condition for the robustly strict bounded real property of this type of uncertain quantum system is proposed.This paper focuses on the study of coherent robust H^∞controller design for quantum systems with uncertainties in the interaction Hamiltonian.The desired controller is connected with the uncertain quantum system through direct and indirect couplings.A necessary and sufficient condition is provided to build a connection between the robust H^∞control problem and the scaled H^∞control problem.A numerical procedure is provided to obtain coefficients of a coherent controller.An example is presented to illustrate the controller design method.     

Characteristics of rockburst and its mining technology in mines

In order to resolve how to mine under the condition of high stress with rockburst, this paper analyzes the law of rockburst, and considers that most of the rockbursts occur in the high stress area of stope. A method of rockburst forecast and its steps are given, and three different stages of rockburst are identified. Furthermore, this paper considers that blasting energy can effectively control rockburst by changing the characteristics of rock mass, which decreases the probability of rockburst happening. According to characteristics of rockburst, two feasible mining techniques under rockburst conditions are put forward, that is stoping-and-filling method, and sublevel caving method of mining without any sills in hanging wall.     

An ergonomics study on compatibility of controls of overhead cranes in a heavy engineering factory in West Bengal

Ergonomics studies, on the machine control and the resultant movements of the cabins and the hooks in 51 electric overhead travelling cranes in a heavy engineering factory, showed that control-movement compatibility is absent in most of the cranes. Also, the layout of the groups of controls and the orientations of each of the individual controls with respect to the operators' seats varied from one crane to another. As the operators were shifted from one crane to another every week, there was a high chance of making mistakes during moving the controls, which might have resulted in severe accidents, especially during periods of high workload. A number of low-cost ergonomics solutions have been recommended to minimize these problems.     

生命之糖-海藻糖

糖类作为与人们日常饮食息息相关的食品原料,始终吸引着国内外的食品工作者致力于其实用性和功能性的研究.而海藻糖由于其许多特殊的功能特性,在食品、医药等许多领域有着极为良好的应用前景,从而引起了人们的浓厚兴趣.各国纷纷投入大量的人力和物力对其生产技术和应用开发进行研究,日本林原公司首次实现了以淀粉为原料工业化生产海藻糖的技术.