Earticle

The concept of "Plant factory" could realize the multiple targets of high yield, high quality, high efficiency and security. It had become the trend of agricultural development. It solved the growing contradiction between people's increasing demand for green, organic food and the diminishing agricultural arable area in China. According to the research on the key technologies of plant factory, a small simulated environment for crop growth (i.e., a growth cabinet) was designed. The growth cabinet used the light-emitting diode (LED) light source as crop growth light and simulated ecological environment artificially based on the requirement of crop growth and development. The crop can obtain suitable environmental conditions for growth and development in anti-season and non-suitable environmental conditions by using the sensor and embedded technology. The results of experiments showed that the crop growth cabinet’s structure design was reasonable and had the advantages such as reliable performance, low-carbon, intelligence and security.

Self-organization clustering is based ona variety of studies for MWSNs (mobile wireless sensor networks) as well as WSNs (Wireless Sensor Networks). The size of the sensor field in MWSNs is often larger than in WSNs. When the sensor field is too large, energy inefficiency may result when cluster-heads broadcast an Advertisement Message over the sensor field area.In this paper, we calculate the optimal transmission range for broadcasting an Advertisement Message efficiently. We analyze the number of non-receiving nodes in relation to the transmission range when self-organization clustering protocols are used in mobile environments and propose aTTC (Two-Tier Clustering)method to reduce the number of non-receiving nodes that result when the transmission range is controlled. TTC evenly distributes cluster-head nodes over the network field and prevents any cluster-head clumping generated by self-organization clustering. Consequently, our TTC protocol result in reduced data loss, increased energy efficiency, and enhanced sensor network field robustness by reducing the number of Advertisement Message non-receiving nodes.

To solve the traditional dynamic decision making time relationship problem, this paper introduced a new dynamic multi-attribute decision making method based on advantage retention degree (ARD). According to the logic continuity of decision result at adjoining periods, the concepts of dynamic decision making and retain ability were described, then the dynamic decision making was realized by the calculation of ordering vector based on ARD. The analysis of numerical examples shows that the distinction among components of ordering vector with retain ability is increased, and dynamic multi-attribute decision making based on ARD can solve the problem that the decision couldn’t be made if the components are same during the traditional static decision making process. Finally, the rationality of new decision method is proved by the decision results.

This paper first describes how to process SoC (State of Charge) streams made up of temporal and spatial stamps, altitude, SoC reading, velocity, and the like. Collected by a probe vehicle on the same road in Jeju city, Republic of Korea, multiple times, each stream has its own initial SoC and speed. The driving distance is calculated by adding up the line segment connecting two consecutive sensor points. For each stream, we plot 1) the absolute SoC change to figure out the SoC dynamics, 2) the consumed SoC change to find the similarity between different streams, and 3) the normalized curves to build a common SoC change model. Next, the artificial neural network is exploited to trace a common pattern out of them, aiming at providing an essential basis for navigation applications supporting electric vehicles. The analysis result reveals that the model can find reasonable representative values out of different streams for each subsection, even with a simple model having just one input variable denoting the distance from the start point and one output variable denoting the SoC reading. Our model keeps the trace error less than 5 % for the duration in which the vehicle speed is the same for each stream.

Fuzzy tracking control discuss the pure model behavior and ignore the original mathematical model, make the picking robot arm gain accurate perception ability to complex environmental condition, control its velocity and reach smoothly the target position. This paper proposed fuzzy tracking controller algorithm for obtaining the joints position relative to the desired trajectory, which drive stably 3 joints tending to be stable in 1.5s on the conditions of changeable environment, reflecting the strong robustness and stability of the tracking control system, enhancing their positioning and grasping stability to restrain picking robot arm chattering.

This article proposes the study and simulation of an induction machine supplied with a photovoltaic generator to ensure the designed volume control of two coupled tanks. We propose a sliding mode control technique to make the speed and the flux of the induction machine robust to parameter variations and control the volume of water containing in the second tank. The results of simulations of all the chain of conversion, carried out under MATLAB/Simulink software, made it possible to evaluate the performances of the proposed system.

The filling valve and relief valve are core components to ensure the rapid filling of fluid and the stable pressure unloading in the large press. To further improve the filling speed of the filling valve with the function of pressure relief, a novel high-flow filling valve based on compound flow channels and multi-stage hydraulic resistance was designed. The mathematical model and simulation model of the structure of multi-stage hydraulic resistance based on AMESim were established, the influence rules of the critical parameters of the annular hydraulic resistance on pressure relief characteristics were analyzed. The multi-stage annular structure can achieve multi-stage pressure relief. The numerical analysis model of the filling valve with detailed structures based on Fluent was built. The curves of multi-stage pressure unloading based on the pressure contours and velocity contours show that the designed valve has good multi-stage relief characteristics, and the filling rapidity and unloading stability can also be balanced well. Comparing to the traditional single-channel filling valve, the valve with compound flow channels can significantly improve the filling rate according to the numerical analysis in Fluent. The novel designed hydraulic component for filling has the function of high-flow filling and steady pressure unloading. Therefore, it has good engineering application value.

Recently, it is anticipated that high voltage direct current (HVDC) systems will be applied to interconnection between the mainland and off-shore wind farms, power flow control for alternating current (AC) power girds, long distance transmission, and interconnection of the supergrid. For these reasons, controllers and protection systems as subsystems for the various HVDC system applications have been developing. It is difficult to test them in the real HVDC system practically because the HVDC system is a huge system. In this paper, a hardware-in-the-loop simulation (HILS) system based on the eMEGAsim real-time digital simulator (RTDS) supplied by OPAL-RT. CIRGE benchmark HVDC system is modeled and a CompactRIO-based controller of the HVDC system is designed. The controller is tested in the HILS system to show the control performance.

Up to now, plenty of CAD softwares have no function of extension for non-circular curves. Intelligent extension-technology for non-circular curves was studied in this article based on a principle of trend extrapolation. Four kinds of intelligent extension-models were built. These models include quadratic extension-model, cubic extension-model, exponential extension-model, and Gompertz extension-model. Moreover, some methods identifying and choosing for extension-models were discussed, respectively. Several applications of intelligent extension for non-circular curves were offered, which shows us that some curves can be extended for a long distance accurately while they are consistent with the type of extension-models; on the other hand, extension-models built can be available for approximate extension for a short distance while the shapes of non-circular curves are arbitrary. The theories in this paper, as core technologies and key generic problems, can be used for existing CAD softwares to upgrade or develop secondarily.