A novel regenerative braking algorithm based on regenerative torque optimization with emulate engine compression braking (EECB) was proposed to make effective and maximum use of brake energy in order to improve fuel e...A novel regenerative braking algorithm based on regenerative torque optimization with emulate engine compression braking (EECB) was proposed to make effective and maximum use of brake energy in order to improve fuel economy.The actual brake oil pressure of driving wheel which is reduced by the amount of the regenerative braking force is supplied from the electronic hydraulic brake system.Regenerative torque optimization maximizes the actual regenerative power recuperation by energy storage component,and EECB is a useful extended type of regenerative braking.The simulation results show that actual regenerative power recuperation for the novel regenerative braking algorithm is more than using conventional one,and life-span of brake disks is prolonged for the novel algorithm.展开更多
Energy regeneration during braking is an important technique for hybrid electric vehicle (HEV) to improve their fuel economy and extend their driving range. Due to the effect of regenerative braking torque which is ad...Energy regeneration during braking is an important technique for hybrid electric vehicle (HEV) to improve their fuel economy and extend their driving range. Due to the effect of regenerative braking torque which is added by electric motor, the braking torque distribution between front and rear axles should be changed and the control logic of anti-lock braking system (ABS) ought to be adjusted according to the regenerative braking torque. This paper put forward a braking control strategy for hybrid electric vehicle; the control strategy is implemented with eight DOFs (Degree-of-Freedom) nonlinear vehicle forward simulation model which is built under the environment of Matlab/Simulink. Based on target wheel slip ratio, a fuzzy logic approach was applied to maintain the optimal target slip ratio so that best compromise between hydraulic torque and regenerative torque can be obtained for the vehicle.展开更多
The high failure rate of crane brake results from improper choice of brakingtorque. The mathematical model of reliability for the crane brake parameters is introduced. Based onlarge amount of actual data the parameter...The high failure rate of crane brake results from improper choice of brakingtorque. The mathematical model of reliability for the crane brake parameters is introduced. Based onlarge amount of actual data the parameter reliabilities of 5 approx 50 t general overheadtravelling cranes are calculated, the probabilities that the braking torque is less than the statictorque acting on the axle when the load moves down are obtained. Moreover, the ways to improve thereliability of brake parameters are discussed, the most reasonable values of braking safetycoefficient are given.展开更多
The theory of energy regeneration in electric vehicle (EV) has been introduced in most papers, but the mathematic model of EV energy regeneration system was little studied. In this paper the mathematic model of EV ene...The theory of energy regeneration in electric vehicle (EV) has been introduced in most papers, but the mathematic model of EV energy regeneration system was little studied. In this paper the mathematic model of EV energy regeneration system is studied, and then the system ability under four control strategies is analyzed. In the end the system reliability is researched, and the calculation model of system reliability is proposed.展开更多
A multi-body dynamic rigid-flexible coupling model of landing gear is established to study the gear walk instability caused by the friction characteristics of the brake disc.After validating the model with the experim...A multi-body dynamic rigid-flexible coupling model of landing gear is established to study the gear walk instability caused by the friction characteristics of the brake disc.After validating the model with the experimental results,the influence of the landing gear structure and braking system parameters on gear walk is further investigated.Among the above factors,the slope of the graph for the friction coefficient of the brake disc and the relative velocity of brake stators and rotors is the most influential factor on gear walk instability.Phase trajectory analysis verifies that gear walk occurs when the coupling of multiple factors causes the system to exhibit an equivalent negative damping trend.To consider a more realistic braking case,a back propagation neural network method is employed to describe the nonlinear behavior of the friction coefficient of the brake disc.With the realistic nonlinear model of the friction coefficient,the maximum error in predicting the braking torque is less than 10%and the effect of the brake disc temperature on gear walk is performed.The results reveal that a more negative friction slope may contribute to a more severe unstable gear walk,and reducing the braking pressure is an effective approach to avoid gear walk,which provides help for future braking system design.展开更多
In order to study the variation of brake torque,vibration,pressure fluctuation,exterior noise and internal flow for a hydraulic retarder with different inclination angles and liquid-filled amount,a bench-scale hydraul...In order to study the variation of brake torque,vibration,pressure fluctuation,exterior noise and internal flow for a hydraulic retarder with different inclination angles and liquid-filled amount,a bench-scale hydraulic retarder was built.The INV3020 data collection system was used for the synchronous acquisition of brake torque,vibration,pressure fluctuation and exterior noise signals.Experiments were performed with different inclination angles(90°and 75°)and six liquid-filled amount(50 vol%,60 vol%,70 vol%,80 vol%,90vol%and 100 vol%).The torque-volume ratio was proposed to accurately analyze the influence of inclination angle on the liquid volume in stator and rotor and the brake performance.Mixture multiphase flow model was employed to capture the volume and velocity distribution.The research shows that the brake performance improves and the vibration increases with the decrease of inclination angle and the increase of liquid-filled amount.The pressure fluctuation increases as the liquid-filled amount increases,while the lower inclination angle effectively lowers the pressure fluctuation amplitude.The sound pressure level trends upward with increasing liquid-filled amount,and the lower inclination angle can effectively reduce the noise.The volume distribution of the liquid phase under different liquid-filled amount is basically consistent.The lower inclination angle can induce more vortexes.展开更多
基金The National Hi-Tech Research and Development Program(863)of China(No.2002AA501700No.2003AA501012)
文摘A novel regenerative braking algorithm based on regenerative torque optimization with emulate engine compression braking (EECB) was proposed to make effective and maximum use of brake energy in order to improve fuel economy.The actual brake oil pressure of driving wheel which is reduced by the amount of the regenerative braking force is supplied from the electronic hydraulic brake system.Regenerative torque optimization maximizes the actual regenerative power recuperation by energy storage component,and EECB is a useful extended type of regenerative braking.The simulation results show that actual regenerative power recuperation for the novel regenerative braking algorithm is more than using conventional one,and life-span of brake disks is prolonged for the novel algorithm.
基金863 National Project EQ7200HEV hybridelectric vehicle (2001AA501200,2003AA501200)
文摘Energy regeneration during braking is an important technique for hybrid electric vehicle (HEV) to improve their fuel economy and extend their driving range. Due to the effect of regenerative braking torque which is added by electric motor, the braking torque distribution between front and rear axles should be changed and the control logic of anti-lock braking system (ABS) ought to be adjusted according to the regenerative braking torque. This paper put forward a braking control strategy for hybrid electric vehicle; the control strategy is implemented with eight DOFs (Degree-of-Freedom) nonlinear vehicle forward simulation model which is built under the environment of Matlab/Simulink. Based on target wheel slip ratio, a fuzzy logic approach was applied to maintain the optimal target slip ratio so that best compromise between hydraulic torque and regenerative torque can be obtained for the vehicle.
基金This project is supported by Provincial natural Science Foundation of Shanxi(No.20011051).
文摘The high failure rate of crane brake results from improper choice of brakingtorque. The mathematical model of reliability for the crane brake parameters is introduced. Based onlarge amount of actual data the parameter reliabilities of 5 approx 50 t general overheadtravelling cranes are calculated, the probabilities that the braking torque is less than the statictorque acting on the axle when the load moves down are obtained. Moreover, the ways to improve thereliability of brake parameters are discussed, the most reasonable values of braking safetycoefficient are given.
文摘The theory of energy regeneration in electric vehicle (EV) has been introduced in most papers, but the mathematic model of EV energy regeneration system was little studied. In this paper the mathematic model of EV energy regeneration system is studied, and then the system ability under four control strategies is analyzed. In the end the system reliability is researched, and the calculation model of system reliability is proposed.
基金the National Natural Science Foundation of China(No.11872312)the Program of Introducing Talents of Discipline to Universities,China(No.BP0719007)the Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University,China(No.CX2022002)。
文摘A multi-body dynamic rigid-flexible coupling model of landing gear is established to study the gear walk instability caused by the friction characteristics of the brake disc.After validating the model with the experimental results,the influence of the landing gear structure and braking system parameters on gear walk is further investigated.Among the above factors,the slope of the graph for the friction coefficient of the brake disc and the relative velocity of brake stators and rotors is the most influential factor on gear walk instability.Phase trajectory analysis verifies that gear walk occurs when the coupling of multiple factors causes the system to exhibit an equivalent negative damping trend.To consider a more realistic braking case,a back propagation neural network method is employed to describe the nonlinear behavior of the friction coefficient of the brake disc.With the realistic nonlinear model of the friction coefficient,the maximum error in predicting the braking torque is less than 10%and the effect of the brake disc temperature on gear walk is performed.The results reveal that a more negative friction slope may contribute to a more severe unstable gear walk,and reducing the braking pressure is an effective approach to avoid gear walk,which provides help for future braking system design.
基金supported by National Natural Science Foundation of China(No.51879122,51579117,51779106)National Key Research and Development Program of China(Grant No.2016YFB0200901,2017YFC0804107)+5 种基金Zhenjiang key research and development plan(GY2017001,GY2018025)the Open Research Subject of Key Laboratory of Fluid and Power Machinery,Ministry of Education,Xihua University(szjj2017-094,szjj2016-068)Sichuan Provincial Key Lab of Process Equipment and Control(GK201614,GK201816)Jiangsu University Young Talent training Program-Outstanding Young backbone TeacherProgram Development of Jiangsu Higher Education Institutions(PAPD)Jiangsu top six talent summit project(GDZB-017)。
文摘In order to study the variation of brake torque,vibration,pressure fluctuation,exterior noise and internal flow for a hydraulic retarder with different inclination angles and liquid-filled amount,a bench-scale hydraulic retarder was built.The INV3020 data collection system was used for the synchronous acquisition of brake torque,vibration,pressure fluctuation and exterior noise signals.Experiments were performed with different inclination angles(90°and 75°)and six liquid-filled amount(50 vol%,60 vol%,70 vol%,80 vol%,90vol%and 100 vol%).The torque-volume ratio was proposed to accurately analyze the influence of inclination angle on the liquid volume in stator and rotor and the brake performance.Mixture multiphase flow model was employed to capture the volume and velocity distribution.The research shows that the brake performance improves and the vibration increases with the decrease of inclination angle and the increase of liquid-filled amount.The pressure fluctuation increases as the liquid-filled amount increases,while the lower inclination angle effectively lowers the pressure fluctuation amplitude.The sound pressure level trends upward with increasing liquid-filled amount,and the lower inclination angle can effectively reduce the noise.The volume distribution of the liquid phase under different liquid-filled amount is basically consistent.The lower inclination angle can induce more vortexes.