Table of Content

25 January 2023, Volume 45 Issue 1 Previous Issue    Next Issue

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Path Following Method of Intelligent Vehicles Based on Improved Pure Tracking Shiju Pan,Yongle Li,Zixian Li,Binbing He,Yuan Zhu,Youchun Xu 2023, 45 (1):  1-8.  doi: 10.19562/j.chinasae.qcgc.2023.01.001 Abstract ( 379 )   HTML ( 44 )   PDF (2106KB) ( 316 )   Save In order to improve the path following accuracy and driving stability of intelligent vehicles， a path following method based on improved pure tracking is proposed. Firstly， the path following model based on pure tracking is established， and the control effect of the pure tracking model under the condition of initial error is analyzed. Secondly， the heading error is used as the feedback variable to compensate the pure tracking method， and the quasi fuzzy method is used to realize the dynamic adjustment of the compensation weight with the lateral error and the heading error as the input and the compensation weight as the output. Finally， the control parameters are selected through the real vehicle test， and the control performance of the proposed method is verified. The results show that the method can eliminate the errors quickly under different initial errors and different target driving speeds and ensure the driving stability， and the method has better path following effect and spends less compute time. Figures and Tables | References | Related Articles | Metrics

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Study on Motion Planning of Autonomous Vehicles in Cut-in Scenes Based on Dynamic Game Algorithm Fengchong Lan,Yingjie Liu,Jiqing Chen,Zhaolin Liu 2023, 45 (1):  9-19.  doi: 10.19562/j.chinasae.qcgc.2023.01.002 Abstract ( 242 )   HTML ( 17 )   PDF (3526KB) ( 284 )   Save In view of that in vehicle lane change and cut-in scenes， autonomous vehicles are prone to frequent false-deceleration and false-avoidance， leading to the reduction in traffic capacity and occupant comfort， a decision-making and planning algorithm based on the dynamic gaming between ego vehicle and adjacent vehicle is proposed. In the behavior decision-making layer， according to the conflicting relationship between ego vehicle and adjacent vehicle in the cut-in scene， the motion model of the whole system is established by combining the motion equations of relevant vehicles， and the cut-in game model considering the state of adjacent vehicle is constructed， to design the gain function of safety and rid comfort， conduct driving behavior game， and output behavior decision results. In the trajectory planning layer， the constraints for obstacle avoidance is established based on vehicle spacing， and the vehicle dynamics constraints are defined by the variable curvature of sigmoid function trajectory and the time component of speed tangent vector. Meanwhile， with concurrent considerations of the requirements of driving habits and ride comfort in weighted gain mode， a mathematical model of trajectory planning is established to solve out the motion trajectory， meeting the requirements of the upper-level game decision. The results of Carsim-Simulink co-simulation show that under different initial conditions， the ego vehicle and cut-in adjacent vehicle can conduct various forms of rational interactive decision-making， accurately complete the motion planning task in cut-in scene. In addition， the vehicles can accurately follow the output trajectory， more conforming the common driving habits and enhancing vehicle comfort. Figures and Tables | References | Related Articles | Metrics

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AFS/DYC Coordinated Control of Intelligent Vehicles Based on Improved Hierarchical Extensibility Theory Pulei Xu,Yingfeng Cai,Yubo Lian,Xiaoqiang Sun,Hai Wang,Long Chen,Yilin Zhong 2023, 45 (1):  20-31.  doi: 10.19562/j.chinasae.qcgc.2023.01.003 Abstract ( 219 )   HTML ( 9 )   PDF (5343KB) ( 246 )   Save For the problem of emergency obstacle avoidance and stable control of large curvature conditions， the AFS and DYC coordinated control system based on improved hierarchical extensibility theory is proposed， and the whale algorithm is introduced to solve the adaptive division problem of the extendable boundary， which not only simplifies the boundary determination process of the hierarchical extensibility theory， but also curbs some of the strong output oscillations of the controller， which significantly improves the stability and safety of the vehicle control. The proposed AFS/DYC coordination control system is divided into two layers. The upper layer is an improved hierarchical extendable coordination module and the lower layer is an AFS/DYC controller module. The upper extendable coordination module mainly determines the weight coefficients of AFS and DYC through the yaw rate， longitudinal vehicle speed and planned path curvature， and the lower controller module mainly distributes the output of AFS and DYC through the weight coefficient determined by the upper coordination module， and finally realizes the stability control of intelligent vehicles. The joint simulation results of Carsim and Simulink show that the control effect of the proposed coordinated control system on the yaw rate and longitudinal vehicle speed is largely improved compared with the hierarchical extendable control and ordinary extendable control under the working conditions of large curvature and curvature mutation such as emergency obstacle avoidance and double shift line. Figures and Tables | References | Related Articles | Metrics

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Automatic Emergency Braking System Based on Model Predictive Control with Adaptive Sampling Time Yongtao Liu,Chuanpan Liu,Xiangan Liu,Yisong Chen,Jie Qiao 2023, 45 (1):  32-41.  doi: 10.19562/j.chinasae.qcgc.2023.01.004 Abstract ( 203 )   HTML ( 13 )   PDF (4654KB) ( 160 )   Save In this paper， a multi-objective MPC control strategy is proposed to solve the problems of lack of comfort consideration and poor control accuracy in the control process of traditional AEB system. Firstly， the emergency coefficients of the scenarios are calculated by introducing in the fuzzy rules， and an adaptive MPC controller is designed based on the fuzzy rules. Then the lower controller is designed by using the PID feedback control and inverse engine model. Finally， the simulation test is carried out through PreScan and Simulink joint platform. The results show that the AEB system based on the proposed strategy can successfully avoid collision under two typical scenarios and various working conditions， with the acceleration change rate always in the comfort range. The final distance between the two vehicles is 1.74~4.18 m， which can ensure the comfort and effectiveness of the vehicle during the automatic emergency braking process. Figures and Tables | References | Related Articles | Metrics

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Research on Intelligent Vehicle Test Method Based on Digital Twin Technology Shulian Zhao,Fei Lai,Keqiang Li,Tao Chen,Zhangjie Meng,Yichao Tang,Siyu Wu,Haodong Tian 2023, 45 (1):  42-51.  doi: 10.19562/j.chinasae.qcgc.2023.01.005 Abstract ( 259 )   HTML ( 24 )   PDF (2911KB) ( 262 )   Save In order to speed up the development and verification of automatic driving function， a test and evaluation method of intelligent vehicle based on digital twin is proposed. Through the digital twin test technology， that is， the real vehicle drives in the real test field and effectively maps and combines with the virtual test environment， the test and verification environment of intelligent vehicle is greatly enriched， with the test efficiency improved and the test cost reduced. Combining real test vehicles and simulation test tools，this paper builds a digital twin autopilot test platform to realize the verification， test and evaluation of the algorithm， and also gives the corresponding case analysis. The rapid application of intelligent vehicle digital twin test and evaluation technology plays a positive role in accelerating the development and promotion of autonomous vehicles. Figures and Tables | References | Related Articles | Metrics

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Construction of Vehicle Fault Knowledge Graph Based on Deep Learning Jie Hu,Yuanjie Li,Hao Geng,Huangzheng Geng,Xiong Guo,Hongwei Yi 2023, 45 (1):  52-60.  doi: 10.19562/j.chinasae.qcgc.2023.01.006 Abstract ( 296 )   HTML ( 23 )   PDF (2791KB) ( 233 )   Save This paper introduces knowledge graph into the field of automobile fault diagnosis. Taking the after-sales business data of a company as the source， a knowledge graph construction process is designed according to the characteristics of the text， which adds text pre-classification and entity reorganization process based on the traditional construction process. Text pre-classification based on DPCNN model is used to deal with the problem of information redundancy in target fields. The combination of entity extraction based on BERT-BiLSTM-MUL-CRF model and entity reorganization based on grammar rules can effectively solve the problems of nested entities and discontinuous entity problems in text. The method combining term similarity and structural similarity is used to complete knowledge fusion. Finally， Neo4j graph database is used for storage so as to complete the construction of vehicle fault knowledge graph. Figures and Tables | References | Related Articles | Metrics

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Research on Dynamic Mechanism of Narrow Body Vehicle in Limit State of Active Roll Dongxin Xu,Guoye Wang,Ya Wang 2023, 45 (1):  61-69.  doi: 10.19562/j.chinasae.qcgc.2023.01.007 Abstract ( 126 )   HTML ( 10 )   PDF (5492KB) ( 125 )   Save The narrow body vehicle can help to solve the problems of road occupation， space waste， energy crisis， and environmental pollution and the active rollover technology can be applied to solve the rollover risk of narrow body vehicle. According to the movement characteristics of active roll of the narrow body vehicle， the body dynamics model of the narrow body vehicle is established. In consideration of the active roll characteristics and the wheel load changes caused by the lateral and longitudinal movement of the vehicle， combined with the UniTire unified tire model， the phase plane analysis of the state parameters of the active roll narrow body vehicle under the limit state conditions is carried out to verify the motion mechanism of the narrow body vehicle， obtain the limit state motion rules and motion characteristics， which lays a foundation for further study on the improvement of stability of the narrow body vehicle. Figures and Tables | References | Related Articles | Metrics

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Study on Power Performance and Economy of Four Motor System of Pure Electric Heavy-Duty Commercial Vehicle Wenkai Huang,Huijun Cheng,Aihua Chu 2023, 45 (1):  70-76.  doi: 10.19562/j.chinasae.qcgc.2023.01.008 Abstract ( 174 )   HTML ( 11 )   PDF (2403KB) ( 192 )   Save In order to study the power performance and economy of the pure electric heavy-duty commercial vehicles applied with the centralized central drive four motor-4AMT transmission system， according to the vehicle dynamics principle， based on the same vehicle configuration， the vehicle dynamics model with the centralized central drive four motor-4AMT transmission system and the single motor-6AMT transmission system respectively is established firstly. Secondly， different parameters such as motors， gearbox， shift points and numbers of working motors are set. Then， according to the dynamic and economic test cycles， the dynamic and economic results are obtained from simulation and verified by the tests. The results show that the centralized central drive four motor-4AMT transmission system has obvious advantages in power and economy performance. Figures and Tables | References | Related Articles | Metrics

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Research on the Performance of Regenerative Suspension with Buffer Huixin Song,Bingyi Liu,Liang Gu,Jinqiu Zhang 2023, 45 (1):  77-85.  doi: 10.19562/j.chinasae.qcgc.2023.01.009 Abstract ( 130 )   HTML ( 10 )   PDF (3507KB) ( 167 )   Save In order to solve the problem of the deterioration of the performance of the regenerative suspension caused by inertial mass， the solution of the absorber in series with buffer is studied. A two degree of freedom regenerative suspension model with buffer is established. The theoretical research shows that adding buffer can improve the spring loaded mass acceleration， suspension dynamic deflection and reduce the inertia force. Through the analysis of transmission characteristics， the effect of the buffer on the velocity amplitude of the absorber is revealed. Comparing the suspension dissipation power with or without buffer， the result shows that the buffer reduces the suspension dissipation power. Through the bench comparison test， it is verified that adding the buffer can effectively improve the performance of the regenerative suspension， with the root mean square value of spring loaded mass acceleration reduced by 58.0%， the root mean square value of wheel relative dynamic load reduced by 33.3%， and the root mean square value of suspension dynamic deflection reduced by 27.6%. Figures and Tables | References | Related Articles | Metrics

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An Experimental Study on Characteristics of Different Fuel Jets in GDI Engine Guodong Liu,Guizhou Ren,Zijie Zhao,Jingyu Zhang,Yanfei Li 2023, 45 (1):  86-92.  doi: 10.19562/j.chinasae.qcgc.2023.01.010 Abstract ( 107 )   HTML ( 4 )   PDF (2848KB) ( 77 )   Save Flash-boiling spray in gasoline direct injection （GDI） engines has the advantage of promoting mixing of oil and gas， but the phenomenon of spray collapse is detrimental to combustion and emission， and studies have found that spray collapse is closely related to single-jet behavior. Therefore， in order to mitigate spray collapse and take full advantage of flash boiling jets in GDI engines， it is extremely important to understand the behavior of flash boiling jet. In this paper， a single-hole fuel injector modified from a five-hole fuel injector is selected， and n-hexane and isooctane fuel are selected to conduct experimental research in a constant volume combustion bomb. The selected fuel temperature is 30 to 130 ℃ and the ambient pressure is 0.2 to 1 bar. By analyzing the relationship between the jet width and different parameters such as superheat degree， nucleation rate， chemical potential and environmental ambient pressure， it is found that the correlation between the jet width and ?\text{?}\mu ·p_{\mathrm{a}\mathrm{m}\mathrm{b}}^{-\mathrm{0.5}} is more than 0.9， which has a good correlation， indicating that the jet width near the nozzle is affected by the phase change potential and the environmental ambient pressure. Figures and Tables | References | Related Articles | Metrics

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Study on Construction of Diesel Combustion Mechanism Based on Soot Particle Size Distribution Prediction and the Impact of Oxygen Concentration Shaohua Liu,Haochuan Dong,Lizhong Shen 2023, 45 (1):  93-103.  doi: 10.19562/j.chinasae.qcgc.2023.01.011 Abstract ( 87 )   HTML ( 2 )   PDF (4131KB) ( 74 )   Save In order to predict the particle size distribution of the diesel engine soot emission， 90% mole fraction n-heptane and 10% mole fraction toluene are chosen as diesel substitutes to construct gas phase dynamics mechanism and surface dynamics mechanism respectively， which are coupled to form the diesel substitute mechanism （HTS mechanism）. Combined with the method of moments numeical model， validation of the HTS mechanism is conducted. Then the effect of oxygen concentration on soot particle size distribution is studied by changing the volume fraction of intake oxygen. The results show that the simulation values calculated by the HTS mechanism are basically consistent with the experimental data in terms of ignition delay period， laminar flame speeds， key species and soot particle size distribution in laminar premixed flames， in-cylinder pressure， heat release rate and emissions of the diesel engine. According to the study on the impact of the oxygen concentration on soot particle size distribution by the HTS mechanism， with the increase of oxygen concentration， the average and peak values of soot particle number density decrease， while particle diameters corresponding to the peak particle number density increase. Moreover， the number density of small soot particles （0~50 nm） decreases as oxygen concentration increases. Figures and Tables | References | Related Articles | Metrics

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Study on Active Control of Exhaust Brake System for Heavy-duty Truck Based on Road Driving Condition Recognition Peilong Shi,Xuan Zhao,Zitong Chen,Qiang Yu 2023, 45 (1):  104-111.  doi: 10.19562/j.chinasae.qcgc.2023.01.012 Abstract ( 132 )   HTML ( 6 )   PDF (3542KB) ( 108 )   Save For the problem of improper use of the service brake system due to unfamiliarity of the driver with the road conditions of heavy truck driving on long downhill sections， which leads to the risk of brake thermal degradation， this paper proposes an active control strategy of the exhaust brake system of heavy-duty trucks based on the identification of road driving conditions. Considering the difficulty of accurately obtaining the longitudinal gradient information of the road in mountainous areas and different characteristics of brake pedal action compared with other road sections， this paper selects the average brake pedal opening range in the time window， the continuous working time and the ratio of the brake pedal working time to construct the driving braking conditions on downhill sections and other road braking conditions. Then the hidden Markov model with continuous time series characteristics， including time window lengths of 30， 60， 90 and 120 s， are established by the causal relationship between the brake pedal action and the opening of the exhaust brake system. And off-line training and on-line identification verification are carried out using the test data of K25-K174 in the Ya’an-Xichang section of Jingkun Expressway. The road test and simulation results show that the control strategy proposed in this paper can accurately identify the driving conditions of the vehicle， realize the active control of the exhaust brake system， reduce the high dependence on the driver， and improve the driving safety of heavy-duty trucks on downhill sections. Figures and Tables | References | Related Articles | Metrics

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Analysis on the Influence of Occupant Displacement and Parameter Optimization Under Pre-crash Braking Condition Zhendong Sun,Haitao Zhu,Weiqiang Peng,Jialin Yang 2023, 45 (1):  112-118.  doi: 10.19562/j.chinasae.qcgc.2023.01.013 Abstract ( 146 )   HTML ( 5 )   PDF (3487KB) ( 109 )   Save The occupant leaning forward will increase the human injury risk under collision conditions after vehicle braking. In this paper， occupant out of position effect and parameter optimization analysis and research are carried out under the pre-collision braking.The forward displacement interval of the occupant's neck under different braking conditions is obtained through the real vehicle braking test. The MADYMO active human body simulation model is established. The variable analysis method is used to study the characteristics of occupant out of position with different braking waveforms. The orthogonal design method is used to conduct sled impact test to obtain the influence of the occupant dislocation factor on the occupant collision injury. The occupant response surface model is established， using the central composite test design （Central composite design ） method to study the correlation between the active seat belt parameters and the occupant's forward displacement out of position， and the optimal parameter combination is obtained by optimizing the design. Figures and Tables | References | Related Articles | Metrics

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Active Control of Road Noise in Vehicles Running on Impulsive Road Zhihao Wang,Zhongming Xu,Ziheng Xia,Hucheng Wang,Jiacong Huang 2023, 45 (1):  119-127.  doi: 10.19562/j.chinasae.qcgc.2023.01.014 Abstract ( 160 )   HTML ( 11 )   PDF (6068KB) ( 166 )   Save Aiming at the problem of performance drop of road noise active control based on LMS algorithm when facing impulsive noise， a road noise active control system based on filter-x least mean absolute deviation （FxLMAD） algorithm is built to control impulsive road noise inside a vehicle. Firstly， the characteristics of in-vehicle noise under the impulsive road condition are analyzed， discovering that the noise is non-Gaussian and more consistent with α stable distribution. Then， a simulation is conducted on noise active control system based on FxLMAD algorithm with a result indicating that the algorithm is simple in structure and requires less calculation efforts， while achieving good noise reduction effects. Finally， an active control system for in-vehicle noise is built and a real fuel vehicle road test is completed on impulsive road. The results show that with the active control system for in-vehicle road noise based on FxLMAD algorithm， the total sound pressure level in the range of 50~500 Hz reduces by about 2dB（A）， apparently superior than that with the ordinary LMS algorithm. Figures and Tables | References | Related Articles | Metrics

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Research on Passive Countermeasures of Torsional Vibration and Rattle of Dual-Clutch Transmission Powertrain Under Acceleration Conditions Yi Zhou,Qingshuang Chen,Xiaohui Shi,Dong Guo,Ziyuan Mei,Guanhua Tan 2023, 45 (1):  128-138.  doi: 10.19562/j.chinasae.qcgc.2023.01.015 Abstract ( 129 )   HTML ( 7 )   PDF (8310KB) ( 137 )   Save This investigation aims to study the characteristics and control methodology of a dual-clutch transmission （DCT） gear rattle under different preselection gear strategies. The rattle objective and subjective assessment， as well as the rattle sensitivity subjected to different angular acceleration levels， were evaluated on the vehicle and rattle test bench， respectively. The no-rattle torsional threshold （NRTT） for quantitatively evaluating the angular acceleration at the transmission input shaft was proposed for the rattle and torsional vibration assessment. The NRTT was derived based on the correlation study of rattle sensitivity， powertrain torsional response and rattle objective and subjective results. Passive torsional vibration and rattle countermeasures include the clutch torsional and dual-mass flywheel damper. The combination of different torsional dampers with clutch micro-slip and centrifugal pendulum vibration absorber was evaluated on the exact vehicle according to the NRTT. The experimental results on the test bench show that the preselection gear significantly changes the rattle characteristics of the dual-clutch transmission， and the rattle jump phenomenon is observed at a certain excitation level. Vehicle experimental results indicate that clutch-type and dual-mass flywheel dampers cannot meet the DCT NRTT requirements at drive conditions， leading to noticeable rattle noise at low-speed regions. The combination of clutch micro-slip or centrifugal pendulum vibration absorber with torsional dampers can meet the no-rattle torsional threshold and eliminate the drive rattle noise of the DCT powertrain under the condition of preselection gears. Figures and Tables | References | Related Articles | Metrics

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A Real-time Thermal Runaway Detection Method of Power Battery Based on Guassian Mixed Model and Hidden Markov Model Yubo Lian,Heping Ling,Junbin Wang,Hua Pan,Zhao Xie 2023, 45 (1):  139-146.  doi: 10.19562/j.chinasae.qcgc.2023.01.016 Abstract ( 141 )   HTML ( 6 )   PDF (2130KB) ( 123 )   Save With the development of the electric vehicle industry in China， the safety performance of the EV batteries has became one of the most important guidelines scaling the overall product value， whereas the detection of the battery thermal runaway is the most concerned safety issue of passengers. To solve the problem of the low accuracy of the conventional thermal runaway detection method， this paper extracts the state feature vectors from the voltage， current， time and other parameters directly observed by the battery sensors and optimizes and screen the features using the Gaussian mixed model. The mixed probability distribution of different safety states of the power battery is evaluated and the hidden Markov method is established by the BW algorithm. The current battery health status is judged by calculating the similar probability of the current observation sequence using the Viterbi algorithm. The experiment results show that the hidden Markov model can more accurately predict the thermal runaway status in real-time compared with the traditional time series detection method. It can realize preliminary thermal runaway risk detection without additional electrochemical testing experiment on the batteries， which improves the safety detection efficiency and reduces the detection cost. Figures and Tables | References | Related Articles | Metrics

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Intelligent Control Strategy of Fresh Air Ratio in Automobile Cabin Under Air-Conditioning Condition and Energy-Saving Effect Evaluation Jianbin Wang,Yuanqing Liang,Shuang Wang 2023, 45 (1):  147-156.  doi: 10.19562/j.chinasae.qcgc.2023.01.017 Abstract ( 135 )   HTML ( 5 )   PDF (11302KB) ( 136 )   Save The development of electric vehicles is restricted by the "significant reduction of actual mileage" caused by air-conditioning. How to reduce the energy consumption of air-conditioning system is an urgent problem to be solved by electric vehicle manufacturers. Considering the balance between fresh air demand and energy consumption， this paper proposes an intelligent control strategy for the proportion of fresh air in the vehicle cabin under air-conditioning conditions， and compares the energy-saving effect of the standard ventilation mode and the intelligent fresh air control mode. The analysis shows that the fresh air proportion intelligent control strategy can significantly reduce the energy consumption of the air conditioning system. When the ambient temperature is 40 ℃， the energy consumption of the compressor can be reduced by about 49.7%， and the actual endurance mileage of the electric vehicle with the battery capacity of 100 kW·h can increase by about 82 km. Figures and Tables | References | Related Articles | Metrics

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Analysis and Solution of Motor Input Shaft Fracture of Dedicated Hybrid Transmission Qiuhua Yuan,Junfeng Hu,Liuming Ruan,Qinhua Li,Minzhi Chen,Xiaolong Deng,Tianbao Tang,Wenqiang Liu 2023, 45 (1):  157-168.  doi: 10.19562/j.chinasae.qcgc.2023.01.018 Abstract ( 175 )   HTML ( 6 )   PDF (7700KB) ( 153 )   Save A type of dedicated hybrid transmission P1 motor input shaft fracture occurs during bench and vehicle test process， on the basis of excluding the strength problem of the motor input shaft itself， overload collision phenomenon of dual mass flywheel （DMF） caused by system resonance is found during continuous short time engine startup process assisted by P1 motor. Based on this， one-dimensional dynamic simulation model is established and overload collision of DMF caused by system resonance is verified. It is found that the torque of motor input shaft is 5-6 times compared with that of the normal engine startup process due to system resonance. Finally， the optimized control strategy is proposed to solve the resonance and overload collision problem of the dual mass flywheel during the engine startup process， and then the fracture problem of motor input shaft is solved， and the NVH performance of the vehicle during engine startup is improved as well. It provides a new idea for similar problem solving in the development process of hybrid power-train system， which has strong instructive and engineering value. Figures and Tables | References | Related Articles | Metrics