scholarly journals Power assisting control for almost-periodic motions with adaptive filters (Verification of energy efficiency using an electric power assisted bicycle)

2016 ◽  
Vol 82 (833) ◽  
pp. 15-00233-15-00233 ◽  
Author(s):  
Kazuyoshi HATADA ◽  
Kentaro HIRATA ◽  
Takuma SATO
Symmetry ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1063 ◽  
Author(s):  
Horng-Lin Shieh ◽  
Fu-Hsien Chen

Energy efficiency and renewable energy are the two main research topics for sustainable energy. In the past ten years, countries around the world have invested a lot of manpower into new energy research. However, in addition to new energy development, energy efficiency technologies need to be emphasized to promote production efficiency and reduce environmental pollution. In order to improve power production efficiency, an integrated solution regarding the issue of electric power load forecasting was proposed in this study. The solution proposed was to, in combination with persistence and search algorithms, establish a new integrated ultra-short-term electric power load forecasting method based on the adaptive-network-based fuzzy inference system (ANFIS) and back-propagation neural network (BPN), which can be applied in forecasting electric power load in Taiwan. The research methodology used in this paper was mainly to acquire and process the all-day electric power load data of Taiwan Power and execute preliminary forecasting values of the electric power load by applying ANFIS, BPN and persistence. The preliminary forecasting values of the electric power load obtained therefrom were called suboptimal solutions and finally the optimal weighted value was determined by applying a search algorithm through integrating the above three methods by weighting. In this paper, the optimal electric power load value was forecasted based on the weighted value obtained therefrom. It was proven through experimental results that the solution proposed in this paper can be used to accurately forecast electric power load, with a minimal error.


2017 ◽  
Vol 866 ◽  
pp. 375-378
Author(s):  
Sathitbunanan Sumate ◽  
Wirote Ritthong

The ball bearings are the rotating components which are widely spread to moving parts for all machinery operation in general industry. This paper presents the ball bearing resistance tool which has a proper size and can handle the maximum load of 300 kg by using an electric power. The ball bearing resistance tool was used to test the bearings No. 6011 cm. The series of tests was performed in the ball bearings lubricated; engine oil SAE 10W/40, auto transmission fluid Dexron, and hydraulic oil. The rotational speeds for testing were vary; 500, 600 and 700 rpm respectively. At each speed, there were various weight; 50, 70, 90,110,130,150, and 170 kg respectively. The results show that the hydraulic oil generated the smallest coefficients of friction and energy efficiency for ball bearing operation.


2019 ◽  
pp. 129-160
Author(s):  
Daniel M. Martínez ◽  
Ben W. Ebenhack ◽  
Travis P. Wagner

Author(s):  
Yukio Ishida ◽  
Tsuyoshi Inoue

Abstract The Jeffcott rotor is a two-degree-of-freedom linear model with a disk at the midspan of a massless elastic shaft. This model executing lateral whirling motions has been widely used in the linear analyses of rotor vibrations. In the Jeffcott rotor, the natural frequency of a forward whirling mode pf and that of a backward whirling mode pb have the relation of internal resonance pf : pb = 1 : (−1). Recently, many researchers analyzed nonlinear phenomena by using the Jeffcott rotor with nonlinear elements. However, they did not take this internal resonance relationship into account. While, in many cases of the practical rotating machinery, such a relationship holds apprximately due to small gyroscopic moment. In this paper, nonlinear phenomena in the vicinity of the major critical speed and the rotational speeds of twice and three times the major critical speed are investigated in the Jeffcott rotor and rotor systems with small gyroscopic moment. Especially, the influences of internal resonance on the nonlinear resonances are studied in detail. The following were clarified theoretically and experimentally: (a) the shape of resonance curves becomes far more complex than that of a single resonance, (b) almost-periodic motions occur, (c) these phenomena are influenced remarkably by the asymmetrical nonlinearity and gyroscopic moment, and (d) the internal resonance phenomena are strongly influenced by the degree of the discrepancies among critical speeds. The results teach us the usage of the Jeffcott rotor in nonlinear analyses of rotor systems may induce incrrect results.


2011 ◽  
Vol 40 (5) ◽  
pp. 1238-1243 ◽  
Author(s):  
Yonghua Cai ◽  
Jinsheng Xiao ◽  
Wenyu Zhao ◽  
Xinfeng Tang ◽  
Qingjie Zhang

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Huabiao Zhang ◽  
Xinye Li ◽  
Dongai Wang ◽  
Tingting Liu

The dynamic response and its stability of a blade rotor with coupled rubbing in the labyrinth seal and tip seal are investigated. The dynamic equations are established based on the Hertz contact rubbing force at the labyrinth seal and the tip rubbing force considering both the contact deformation of the tip seal and the bending deformation of the blade. Numerical simulations show that the coupled rubbing response includes periodic motions, almost periodic motions, and chaotic motions. Compared with the single rubbing fault, coupled rubbing increases the range of rotation velocity of contact. A new continuation shooting method is used in the solution and stability analysis of the periodic response to give the bifurcation diagrams. The paths of the system for entering and exiting chaos are analyzed.


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