For the purpose of analyzing the torsional vibration caused by the gravitational unbalance torque arisen in a spindle system when it is machining heavy work piece,a 10-DOF lumped parameter model was made for the machi...For the purpose of analyzing the torsional vibration caused by the gravitational unbalance torque arisen in a spindle system when it is machining heavy work piece,a 10-DOF lumped parameter model was made for the machine tool spindle system with geared transmission.By using the elementary method and Runge-Kutta method in Matlab,the eigenvalue problem was solved and the pure torsional vibration responses were obtained and examined.The results show that the spindle system cannot operate in the desired constant rotating speed as far as the gravitational unbalance torque is engaged,so it may cause bad effect on machining accuracy.And the torsional vibration increases infinitely near the resonant frequencies,so the spindle system cannot operate normally during these spindle speed ranges.展开更多
The operating principle of an antilock braking system （ABS） is it compares current value of angular acceleration with the threshold value. The advantage of such system is that enough it has only the angular velocity...The operating principle of an antilock braking system （ABS） is it compares current value of angular acceleration with the threshold value. The advantage of such system is that enough it has only the angular velocity sensors. The disadvantage is successive overshoot, i. e. successive transition from wheels locking mode to wheels rolling mode. So braking mechanism can’ t realize the maximum possible torque in the current road conditions. The idea of increasing the braking effectiveness is the intensity of rising pressure depends on the road conditions. The problem is the torque produced by braking mechanism, current road conditions and the value of traction coefficient is unknown For evaluation of these parameters built and training three neural networks. A simulator of random road condition＇s variation was built to test adequacy of the control unites operation in close to real conditions.展开更多
An electrical equivalent circuit model for lithium-ion batteries used for hybrid electric vehicles （HEV） is presented. The model has two RC networks characterizing battery activation and concentration polarization p...An electrical equivalent circuit model for lithium-ion batteries used for hybrid electric vehicles （HEV） is presented. The model has two RC networks characterizing battery activation and concentration polarization process. The parameters of the model are identified using combined experimental and extended Kalman filter （EKF） recursive methods. The open-circuit voltage and ohmic resistance of the battery are directly measured and calculated from experimental measurements, respectively. The rest of the coupled dynamic parameters, i.e. the RC network parameters, are estimated using the EKF method. Experimental and simulation results are presented to demonstrate the efficacy of the proposed circuit model and parameter identification techniques for simulating battery dynamics.展开更多
Based on dynamometer test cycles or plain motorway operation, heavy truck hybridisation must be considered as uneconomic if only the kinetic vehicle energy can be recuperated. In mountainous regions, micro hybridizati...Based on dynamometer test cycles or plain motorway operation, heavy truck hybridisation must be considered as uneconomic if only the kinetic vehicle energy can be recuperated. In mountainous regions, micro hybridization by a 48V-belt generator or mild parallel hybridisation by a large high voltage electric drive can result in considerable fuel consumption savings as well as additional benefits for heavy load utility vehicles. Additional electric power and battery size are still critical design parameters as well as critical cost factors considering the limited space and depreciation time as well as the need for maximum payload. Based on vehicle model simulations, this contribution quantifies fuel consumption savings, recuperation energy harvesting and battery requirements for different truck sizes with test cycles based on realistic route topography. The main route topography parameter for the recuperation benefit is the effective incline that integrates all downhill sections that overcompensates the vehicle resistance by tire friction and air resistance. The simulation parameter studies lead to an analytical benefit estimation, based on load cycle parameters like effective velocity, effective incline as well as the vehicle parameters mass, drag coefficient and cross sectional area. Thus, the return on investment can be assessed by an analytic rule of thumb, based on tracked cycles of existing vehicles.展开更多
This paper select the escalator with large flow in the station as the object, analysing the correlation of the AFC data of the in and out gates and the passenger flow parameters by passenger flow density and the passi...This paper select the escalator with large flow in the station as the object, analysing the correlation of the AFC data of the in and out gates and the passenger flow parameters by passenger flow density and the passing time acquired and calculated in the waiting area of the prediction escalator to select the gates related to the predicted the escalator. NARX neural network is used to predict the model of the passenger flow parameters of the escalator waiting area based on the related gates＇ AFC data, then a probabilistic neural network model was established by using the AFC data and predicted passenger flow parameters as input and the passenger flow status in the escalator waiting area of subway station as output.The result shows the predicting model can predict the passenger flow status of the escalator waiting area better by the AFC data in the subway station. Research result can provide decision basis for the operation management of the subway station.展开更多
基金Project(10033135-2009-11) supported by the Korean Ministry of Knowledge Economy (MKE) through HNK. Co,Ltd.
文摘For the purpose of analyzing the torsional vibration caused by the gravitational unbalance torque arisen in a spindle system when it is machining heavy work piece,a 10-DOF lumped parameter model was made for the machine tool spindle system with geared transmission.By using the elementary method and Runge-Kutta method in Matlab,the eigenvalue problem was solved and the pure torsional vibration responses were obtained and examined.The results show that the spindle system cannot operate in the desired constant rotating speed as far as the gravitational unbalance torque is engaged,so it may cause bad effect on machining accuracy.And the torsional vibration increases infinitely near the resonant frequencies,so the spindle system cannot operate normally during these spindle speed ranges.
文摘The operating principle of an antilock braking system （ABS） is it compares current value of angular acceleration with the threshold value. The advantage of such system is that enough it has only the angular velocity sensors. The disadvantage is successive overshoot, i. e. successive transition from wheels locking mode to wheels rolling mode. So braking mechanism can’ t realize the maximum possible torque in the current road conditions. The idea of increasing the braking effectiveness is the intensity of rising pressure depends on the road conditions. The problem is the torque produced by braking mechanism, current road conditions and the value of traction coefficient is unknown For evaluation of these parameters built and training three neural networks. A simulator of random road condition＇s variation was built to test adequacy of the control unites operation in close to real conditions.
文摘An electrical equivalent circuit model for lithium-ion batteries used for hybrid electric vehicles （HEV） is presented. The model has two RC networks characterizing battery activation and concentration polarization process. The parameters of the model are identified using combined experimental and extended Kalman filter （EKF） recursive methods. The open-circuit voltage and ohmic resistance of the battery are directly measured and calculated from experimental measurements, respectively. The rest of the coupled dynamic parameters, i.e. the RC network parameters, are estimated using the EKF method. Experimental and simulation results are presented to demonstrate the efficacy of the proposed circuit model and parameter identification techniques for simulating battery dynamics.
文摘Based on dynamometer test cycles or plain motorway operation, heavy truck hybridisation must be considered as uneconomic if only the kinetic vehicle energy can be recuperated. In mountainous regions, micro hybridization by a 48V-belt generator or mild parallel hybridisation by a large high voltage electric drive can result in considerable fuel consumption savings as well as additional benefits for heavy load utility vehicles. Additional electric power and battery size are still critical design parameters as well as critical cost factors considering the limited space and depreciation time as well as the need for maximum payload. Based on vehicle model simulations, this contribution quantifies fuel consumption savings, recuperation energy harvesting and battery requirements for different truck sizes with test cycles based on realistic route topography. The main route topography parameter for the recuperation benefit is the effective incline that integrates all downhill sections that overcompensates the vehicle resistance by tire friction and air resistance. The simulation parameter studies lead to an analytical benefit estimation, based on load cycle parameters like effective velocity, effective incline as well as the vehicle parameters mass, drag coefficient and cross sectional area. Thus, the return on investment can be assessed by an analytic rule of thumb, based on tracked cycles of existing vehicles.
文摘This paper select the escalator with large flow in the station as the object, analysing the correlation of the AFC data of the in and out gates and the passenger flow parameters by passenger flow density and the passing time acquired and calculated in the waiting area of the prediction escalator to select the gates related to the predicted the escalator. NARX neural network is used to predict the model of the passenger flow parameters of the escalator waiting area based on the related gates＇ AFC data, then a probabilistic neural network model was established by using the AFC data and predicted passenger flow parameters as input and the passenger flow status in the escalator waiting area of subway station as output.The result shows the predicting model can predict the passenger flow status of the escalator waiting area better by the AFC data in the subway station. Research result can provide decision basis for the operation management of the subway station.
