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Optimal Speed Tracking of Freight Trains Combined with Segmented Soft-Switching Control
Yi Lingzhi,Yi Yu,Wang Yahui,Xie Cheng 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.1
Smoothness of travel speed and stopping accuracy are important for freight trains. However, due to the large mass of freight trains, their driving speed is easy to jitter at the operating condition switching point. For these purposes, this paper designs a Dual Mode Optimal Control (DMOC) for tracking the target travel speed of freight trains. This controller contains two sub-controllers, Adaptive Model Predictive Control (AMPC) and Preview control (PC). An Elman Neural Network (ENN) is incorporated in AMPC to adjust the control weights of MPC in real time to output the optimal driving speed. The Afnity propagation-Fast-minimum covariance determinant algorithm, combined in ENN identifes the noisy samples in the training samples and improves the ftting efect of the network. PC and AMPC are fused together by a soft-switching control method. The soft switching control method based on Tanh function can achieve smooth switching of controllers and obtain a good control efect. By comparing with active disturbance rejection control and fuzzy proportional-integral-derivative under two speed profles, DMOC can efectively reduce the speed jitter of speed tracking, improve the stopping accuracy and timeliness of freight trains, and reduce energy consumption.
An Overview of Whipgrass Breeding Efforts in Sichuan Agricultural University
Yang Chunhua,Zhang Xinquan,Cheng Lingzhi,Liu Lin,Tang Zhisong 한국초지조사료학회 2009 한국초지조사료학회 학술대회논문집 Vol.2009 No.08
Whipgrass [Hemarthriacompressa(Linn.f.)R.Br.] has several outstanding characteristics that make it attractive in livestock production systems. These include superior cool-season growth compared to other C₄ grasses, persistence under grazing on poorly drained soils, and relatively high herbage digestibility that declines at a slower rate with increasing maturity than for most C₄ grasses. More than 50 years hard work, a whipgrass breeding group in Sichuan Agricultural University (SAU) collected 84 accessions from south china. Through germplasm evaluation and breeding, 3 varieties, Chong gao, Guang yi and Ya an, were released by the end of 2009. All of them are very popular in south china from 1986. In the future, the team approach emphasizes plant improvement in seedling vigor and establishment, seed production, cold tolerance, photoperiod response, seasonal distribution of forage production, forage quality, insect and disease resistance.
Tillage and Overseeding Pasture for Winter Forages Production in Lowland Areas of South-west China
Zhang Wenjun,Yang Chunhua,Zhang Xinquan,Cheng Lingzhi,Su Shiming 한국초지조사료학회 2009 한국초지조사료학회 학술대회논문집 Vol.2009 No.08
In lowland areas of south-west China, especially in late winter and early spring, animal nutrition is so poor t㏊t some animals die because of shortages of forage. Farmers in these areas are finding it difficult to conserve sufficient forage. It is a big challenge to find a new strategy to solve the problem, so tillage systems and overseeding of a perennial pasture can influence the performance of winter annual forage production in the future.