Liu Qunxing

Study on braking force distribution based on fuzzy control algorithm

One of the advantages of electric vehicle is its ability to regenerate braking energy compared with conventional motor vehicles. This is able to save the electric energy and extend the drive range of electric vehicle. However, on one hand, regeneration and usage of braking energy with a higher efficiency is still a topic to be studied. On the other hand, allocation of the general braking force between the normal mechanical and electric braking systems in EV seriously affects its safety. In this paper, the braking force distribution during regenerative braking processes of a battery electric bus is studied. Controlled by a fuzzy logic strategy, the regenerative braking energy model is developed, which is embedded in the entire vehicle model. With the theoretical model, the braking force distribution function has been calculated with two factors, vehicle velocity and battery state of charge (SoC). The strategy also takes the comfort requirements of the driver during braking into account. The simulation results in this paper show that in addition to properly distributing the braking force, the regenerative braking energy control strategy can save the energy consumption of the electric bus by 5.5%, 3.9% and 6.4% during China city bus driving cycle, New York bus driving cycle and JapeneselO-15 mode driving cycle, respectively.

Research on risk assessment of hand wearing devices based on analytic hierarchy process

With the continuous maturing mobile internet and the upcoming of 4G era, intelligent wearable equipments which are the next hotspot of intelligent terminal are going to enjoy more promising application prospect in future. Since hand wear equipment is becoming the mainstream of current consumption demand, risk assessment research of hand wearing devices is extremely urgent except for the core technical problems like privacy, safety, practicability and interaction. A sampling experiment on quality safety of available hand wearing devices was carried out in this paper. A risk assessment model was established. Risk assessment of hand wearing devices was studied by the analytic hierarchy process (AHP). Results show that available hand wearing devices are evaluated “middle” risk level. This study can provide references to study quality safety of hand wearing devices.

Analysis for the EMI measurement and propagation path in Hybrid Electric Vehicle

Power electronic equipment are added to Hybrid Electric Vehicle (HEV) comparing to traditional vehicles. The electromagnetic interference (EMI) produced by these equipment is extraordinarily serious, which will have influence on equipment that are attached to them. In this paper, measurement and comparisons on the conducted interference current on the main lines of vehicle-mounted high-power DC power converter are completed; mechanism and path of propagation are analyzed. It is concluded that one part of interference on DC power converter system comes from its own main circuit, another part comes from the motor driver; the propagation of the interference is realized by conducted coupling of common source.