Surface water quality is negatively influenced by the urbanization process to pollutant loads in stormwater runoff and increases in runoff peaks and volumes. The first flush effect is the main impetus for pollutants t...
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Surface water quality is negatively influenced by the urbanization process to pollutant loads in stormwater runoff and increases in runoff peaks and volumes. The first flush effect is the main impetus for pollutants transportations. This study compared the characteristics of first flush effect on stormwater runoff from blacktop driveway, concrete roof, and roof with grassland. The first flush effects of chemical oxygen demand (COD), Ammonium-Nitrogen (NH 3 -N), Nitrate-Nitrogen (NO 3 -N) and Total Phosphorous (TP) were studied through monitoring of rainfall runoff on three different kinds of underlying surface, including bituminous roof, green roof and asphalt road. And four linear relationships for these pollutants were stimulated. The results demonstrated that the first flush effects of these four pollutants on three different kinds of underlying surface presented significantly. Over 80% of pollution load was delivered within the first 40% of the whole runoff period. Thus, retaining the initial runoff could effectively reduce runoff pollution. The linear relationships of four pollutants were presented significantly as well. Most of the correlation coefficients were more than 0.9, which showed that controlling pollution source could significantly diminish pollutants for the similarity of these four pollutants.
The error sources of state of charge (SOC) estimation algorithm on the basis of Kalman filter is analyzed in this paper. Aiming at the influence of the measuring precision of voltage and current in battery management ...
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The error sources of state of charge (SOC) estimation algorithm on the basis of Kalman filter is analyzed in this paper. Aiming at the influence of the measuring precision of voltage and current in battery management system (BMS) to SOC estimation, a simulation analysis is performed independently in Simulink on the assumption that other factors are under ideal conditions, in which the effects of Gaussian white noise and the offset error of measurement of BMS are discussed respectively to simulate the actual vehicle condition. The principle to the precision index design of BMS is proposed according to the simulation result. At last, a high-precision data acquisition system is developed as a precise calibration benchmark device for BMS.
Solving space angles between two lines, two planes, or one line and one plane in engineering drawing is of great significance for machining oblique holes, designing fixtures on inclined planes, or manufacturing proces...
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Solving space angles between two lines, two planes, or one line and one plane in engineering drawing is of great significance for machining oblique holes, designing fixtures on inclined planes, or manufacturing process design. A simple and accurate method based on Line-to-Cone Rotation is proposed to solve space angles. The principle of Line-to-Cone Rotation is that on a plane of projection parallel to a rotation axis, the angle between a line and a plane can be obtained directly when the plane is vertical to the rotation axis.
A wheeled mobile vehicle with 2 DOF articulated frame (2DWAV) is presented in this paper. This vehicle can improve the rough-terrain mobility and stability by reshaping its articulated frame. The analysis complete...
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ISBN:
(纸本)9781424479573
A wheeled mobile vehicle with 2 DOF articulated frame (2DWAV) is presented in this paper. This vehicle can improve the rough-terrain mobility and stability by reshaping its articulated frame. The analysis completes about the influence that the stability of single body's worked on the entire frame stability. For the unique 2 DOF articulated frame, we propose the new concept of correlative stability. The kinematical equations which based on the threedimensional coordinate form the kinematics model of the articulated vehicle system. The correlative stability angle is achieved by using static stability analysis and multi-body kinematics.
Simplified FE (finite element) model about heavy commercial vehicle cab and acoustic cavity are built in this paper. They are verified through the modal analysis and modal test. Then a acousticstructure coupled model ...
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Simplified FE (finite element) model about heavy commercial vehicle cab and acoustic cavity are built in this paper. They are verified through the modal analysis and modal test. Then a acousticstructure coupled model is formed. Modal analysis is performed using ***. It is shown from the simulation result that the modes of coupled system reflect both the characteristics of structural and cave model. Meanwhile, excitations received from road test are acted to the acoustic-structure coupled model to make a frequency response analysis. The interior noise of response is correlative to the measured values well, so the established acousticstructure coupled model can achieve better simulation of interior noise, and it is benefit for the later optimal design of acoustic
In this paper the fundamental of the component mode synthesis was reviewed. In order to optimize the ride comfort of the vehicle, a rigid-flexible coupling model of a car was established by using multibody system ...
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In this paper the fundamental of the component mode synthesis was reviewed. In order to optimize the ride comfort of the vehicle, a rigid-flexible coupling model of a car was established by using multibody system dynamics method and component mode synthesis technology. The flexibility of the car body, twist beam of the rear suspension, and stabilizer rod was considered. The ride comfort of the vehicle was calculated at different vehicle speeds with an interval of 10 km/h from 40 to 150 km/h. The ride comfort was optimized by using the design of experiment method. The optimal combination of suspension stiffness and damping parameters was determined, and the overall weighted acceleration RMS of the seat vibration was reduced by 16.96% at the upper surface of the driver seat on vehicle speed at 70 km/h. The ride comfort was obviously improved. Further simulation analysis shows that the ride comfort is effective improved at the other higher speed when applies optimal suspension parameter obtained.
A novel method, which utilizes harmonic for excitation, is presented to adjust the air-gap magnetic field for permanent magnet synchronous machine. The structure and basic principles of the hybrid excitation PM synchr...
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ISBN:
(纸本)9788986510119
A novel method, which utilizes harmonic for excitation, is presented to adjust the air-gap magnetic field for permanent magnet synchronous machine. The structure and basic principles of the hybrid excitation PM synchronous generator(HEPMSG) are introduced. The no-load and on-load electromagnetic field are calculated based on finite element method, and the waveform and effective value of the winding voltage and characteristics of the machine are gained for different loads. Calculation results demonstrate the new hybrid excitation scheme is feasible. This new method combines the advantages of PM machines and electrical excitation machines. The machine removes the brushes and slip rings, which makes permanent magnet machine keep simple and highly reliable.
A 2DOF reference model of heavy single tractor was set up using the yaw rate and the lateral acceleration as control variables based on analysis of tractor instability mechanism. The reference model of tractor was...
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ISBN:
(纸本)9781424479573
A 2DOF reference model of heavy single tractor was set up using the yaw rate and the lateral acceleration as control variables based on analysis of tractor instability mechanism. The reference model of tractor was simulationcontrolled using allocation strategy of braking moment and control strategy of slip ratio with PD algorithm for typical fishhook steering in Trucksim. The simulation results show that this control method is correct and feasible, the control target that enhance tractor stability has been realized.
A vehicle simulation model for Dual Clutch Transmission (DCT) is designed in Matlab/Simulink, and more importantly, an objective description of the method to evaluate its shift quality based on neural network (NN) is ...
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A vehicle simulation model for Dual Clutch Transmission (DCT) is designed in Matlab/Simulink, and more importantly, an objective description of the method to evaluate its shift quality based on neural network (NN) is implemented. The objective evaluation method adopted the theory of NN prediction; NN is trained and tested with sample vectors comprised by shift quality evaluation index, subjective evaluation rates. The correctness of the vehicle control algorithms and algorithms extracted evaluation index are validated by simulation, and the per-development performance of DCT is predicted successfully. The experimental results show that the evaluation system cannot only be used to realize the objective evaluation of shift quality, but also be used as a reference and guidance role for the calibration vehicles equipped with dual clutch transmission.
A 5DOF model for heavy semi-trailer combination was contrasted with an 8DOF model through dynamic analysis. The 5DOF model was applied because it can satisfactory predict the risk of future rollover and improve calcul...
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A 5DOF model for heavy semi-trailer combination was contrasted with an 8DOF model through dynamic analysis. The 5DOF model was applied because it can satisfactory predict the risk of future rollover and improve calculation speed of system, and its following performance is very perfect. An algorithm of real-time Time-To-Rollover (TTR) rollover warning based on the model and optimal active control strategies for anti-rollover Linear Quadratic Gauss (LQG) / Linear Quadratic Regulation (LQR) based on the algorithm were researched. The real vehicle was active controlled for rollover with differential braking in simulation circumstance. Accuracy and reliability of warning algorithms was also verified by using TruckSim in fishhook etc. steering condition. The result shows that the method can reduce rollover performance index of Lateral Load Transfer Ratio (LTR) effectively and avoid rollover and improve roll stability of the heavy vehicles significantly.
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