Time filter

Source Type

Gao Z.H.,Jilin University | Gao Z.H.,Changan Automobile Holding Ltd 40 | Gao Z.H.,Changan Automobile Holding Ltd | Yan W.,Jilin University | And 3 more authors.
Advanced Materials Research | Year: 2013

A new decision algorithm for ACC systems is proposed. Feasible driving set is defined based on state and control constraints, which represent driver behavior features. And based on the analysis of collected driving data, a second-order range policy is selected to approach real driver behavior. Under dynamic output feedback control framework, the decision algorithm has been developed based on quadratic boundedness theory and given in terms of linear matrix inequalities. Performance of the proposed algorithm is verified by Simulink and Carsim co-simulation. © (2013) Trans Tech Publications, Switzerland.


Gao Z.,Jilin University | Li C.,Jilin University | Hu H.,Jilin University | Chen C.,Wayne State University | And 2 more authors.
SAE Technical Papers | Year: 2016

At the collision moment, a driver's lower extremity will be in different foot position, which leads to the different posture of the lower extremity with various muscle activations. These will affect the driver's injury during collision, so it is necessary to investigate further. A simulated collision scene was constructed, and 20 participants (10 male and 10 female) were recruited for the test in a driving simulator. The braking posture and muscle activation of eight major muscles of driver's lower extremity (both legs) were measured. The muscle activations in different postures were then analyzed. At the collision moment, the right leg was possible to be on the brake (male, 40%; female, 45%), in the air (male, 27.5%; female, 37.5%) or even on the accelerator (male, 25%; female, 12.5%). The left leg was on the floor all along. Muscle activation of gastrocnemius, vastus medialis and vastus lateralis of right legs of male drivers in brake pedal region were significantly larger compared to the other positions, and that of soleus and hamstrings were significantly greater compared to air region. Gluteus maximus showed small muscle activation all along (<10%). Right leg showed larger muscle activation than left leg in the air and brake pedal region for most muscles of both genders (except for gluteus maximus). The right and left legs were in different postures at the collision moment, which affects the muscle activation. Differences were also found between muscles and genders. Therefore, muscle activation should be precisely measured, and the influence of these factors should be considered in the future injury analysis of lower extremity. © 2016 SAE International.


Gao Z.,Jilin University | Zhang X.,Jilin University | Hu H.,Jilin University | Guo D.,Jilin University | And 2 more authors.
SAE Technical Papers | Year: 2016

The poor low-temperature behavior of Li-ion batteries has limited its application in the field of electric vehicles and hybrid electric vehicles. Many previous studies concentrate on developing new type of electrolyte to solve this problem. However, according to recent research, the key limitation at low temperature is the low diffusivity of lithium ion in the anode electrodes. Hence, it is potential to study anode materials to improve low-temperature behavior of LIBs. ZnFe2O4 with higher theoretical capacity is low toxicity and abundance, contributing to its commercial application. Different ZnFe2O4 crystalline shapes have different particle sizes. Among them, the cubic ZnFe2O4 with smaller particle size will increase its own electronic and ionic conductance at lower temperature. In this regard, we evaluated low-temperature performance of LIBs with ZnFe2O4 cubes as anode materials at -25°C. The morphology, discharge/charge capacity, cyclic stability and electrochemical impedance of the electrode were investigated. It is found that the electrochemical behavior of ZnFe2O4 cubes at lower temperature is poor than that at ambient temperature, but is much better than that of commercial graphite. After the first low-temperature cycle, the reversible capacity of cubic ZnFe2O4 is still high to 422.2 mAh g-1 and its retention rate of the initial capacity can reach about 44.64%. And, the ZnFe2O4 cubes can keep normal charging and discharging even after 100 cycles at -25°C, which can reduce the security hazard caused by the difficulty of Li-ion intercalation. These findings in our research have certain reference value for the development of LIBs applied at lower temperature. © Copyright 2016 SAE International.


Gao Z.,Jilin University | Guo J.,Jilin University | Guan H.,Jilin University | Dong Y.,Changan Automobile Holding Ltd. | Qiao Y.,Changan Automobile Holding Ltd.
Advanced Materials Research | Year: 2011

Through the analysis of vehicle dynamic and characteristic and vehicle-road environment, the ESP stability boundary can be easily determined. But from the point of the system vehicle-driver-environment, ignoring the analysis of driver operation behavior in extreme situation, it is difficult to determining the system optimization direction reasonably and improving the ESP system control quality based on the analysis of ESP system response performance and vehicle comfort performance when brkae intervening. Based on the driver's complaint analysis in ESP performance test, combing with the aim of active safety system, this paper comes up with a set of new guidelines to design and development ESP system from the point of vehicle-driver-environment system.


Gao Z.,Jilin University | Gao Z.,Changan Automobile Holding Ltd. | Gao Z.,Changan Automobile Holding Ltd. Automotive Engineering Institute | Li C.,Jilin University | And 6 more authors.
Traffic Injury Prevention | Year: 2016

Objective: A driver's instinctive response of the lower extremity in braking movement consists of two parts, including reaction time and braking reaction behavior. It is critical to consider these two components when conducting studies concerning driver's brake movement intention and injury analysis. The purposes of this study were to investigate the driver reaction time to an oncoming collision and muscle activation of lower extremity muscles at the collision moment. The ultimate goal is to provide data that aid in both the optimization of intervention time of an active safety system and the improvement of precise protection performance of a passive safety system. Method: A simulated collision scene was constructed in a driving simulator, and 40 young volunteers (20 male and 20 female) were recruited for tests. Vehicle control parameters and electromyography characteristics of eight muscles of the lower extremity were recorded. The driver reaction time was divided into pre-motor time (PMT) and muscle activation time (MAT). Muscle activation level (ACOL) at the collision moment was calculated and analysed. Results: PMT was shortest for the tibialis anterior (TA) muscle (243∼317 ms for male and 278∼438 ms for female). Average MAT of the TA ranged from 28-55 ms. ACOL was large (5∼31% for male and 5∼23% for female) at 50 km/h, but small (<12%) at 100 km/h. ACOL of the gluteus maximus was smallest (<3%) in the 25 and 100 km/h tests. ACOL of RF of men was significantly smaller than that of women at different speeds. Conclusions: Ankle dorsiflexion is firstly activated at the beginning of the emergency brake motion. Males showed stronger reaction ability than females, as suggested by male's shorter PMT. The detection of driver's brake intention is upwards of 55ms sooner after introducing the electromyography. Muscle activation of the lower extremity is an important factor for 50 km/h collision injury analysis. For higher speed collisions, this might not be a major factor. The activations of certain muscles may be ignored for crash injury analysis at certain speeds, such as gluteus maximus at 25 or 100 km/h. Furthermore, the activation of certain muscles should be differentiated between males and females during injury analysis. © 2016 Taylor & Francis Group, LLC.


Wang D.,Jilin University | Song X.W.,Jilin University | Song X.W.,Hunan University | Sun X.Y.,Jilin University | And 3 more authors.
Advanced Materials Research | Year: 2014

In this paper, a finite element model of human head was established based on CT scanning on a 40-year-old and 50 percentile Chinese male volunteer, and the model was verified with the experiment conducted by Verschueren and skull fracture was investigated during the collision. The frontal of head was impacted with different velocities during the impact tests. A break-deletion element process was represented to simulate the pathological phenomena of skull fracture.The results showed that the simulation results and experimental results were in a good consistency on both mechanics and pathology. © (2014) Trans Tech Publications, Switzerland.


Gao Z.H.,Jilin University | Gao Z.H.,Changan Automobile Holding Ltd | Guo Z.Y.,Jilin University | Zhou S.H.,Jilin University | And 2 more authors.
Applied Mechanics and Materials | Year: 2013

With the increasing of ESP's equipment rate in the vehicle market, how to evaluate and promote the performance of the syetem which the vehicle equipped with is becoming the major issue in decades. In this paper, a method from a psychological perspective is brought forward to build an accessment system for the electronic stability program which is based on the mental factor of the drivers after the great effort on the survey of the appilication of the Ergonomics-Psychology throught the world. The system concluded five factors: workload, situation awareness, trust, stress and locus of control, and formed a questionnaire based on 13 basic questions. After the deployment of the the driver simulator test, the results show that the evaluation system provides a new methold to access the electronic stability program, and should give a bright sight to the subjective-objective correlation of handling and stability. © (2013) Trans Tech Publications, Switzerland.


PubMed | Jilin University, Wayne State University and Changan Automobile Holding Ltd
Type: | Journal: Bio-medical materials and engineering | Year: 2015

A drivers response to a front-coming vehicle collision consists of braking reaction time and braking behavior. The purpose was to investigate drivers responses at different speeds, relative distances, and particularly the behavior on the accelerator at the collision moment. Twelve young men participated in driving simulator tests. Vehicle parameters and electromyograms (EMGs) of the drivers tibialis anterior muscles were recorded and responses were analyzed. The drivers braking reaction time windows were divided into pre-motor time, muscle activation time, accelerator release time, and movement time. By comparing the reaction times and collision times, braking behaviors were investigated. It was found that movement times (r = -0.281) decreased with speed. Pre-motor times (r = 0.326) and muscle activation times (r = 0.281) increased with relative distance. At the collision moment, the probability of the drivers lower extremity being on the accelerator, in the air, and on the brake pedal was 7.4%, 18.9%, and 73.7%, respectively. With higher speeds and smaller distances, the lower extremity was more likely to be in the air or even on the accelerator in different muscle activation states. The driver will collide in normal driving postures which muscles are not or not fully activated in very urgent situation.


PubMed | Jilin University, Wayne State University and Changan Automobile Holding Ltd
Type: | Journal: Bio-medical materials and engineering | Year: 2015

Frontal vehicle collisions can cause injury to a drivers cervical muscles resulting from intense changes in muscle strain and muscle load. This study investigated the influence of collision forces in a sled test environment using a modified Hybrid III 50th percentile dummy equipped with simulated spring-type muscles. Cervical muscle responses including strain and load of the sternocleidomastoid (SCM), splenius capitis (SPL), and trapezius (TRP) were analyzed, and muscle injury was assessed. The SCM, SPL, and TRP suffered average peak muscle strains of 21%, 40%, and 23%, respectively, exceeding the injury threshold. The average peak muscle loads of the SCM, SPL and TRP were 11 N, 25 N, and 25 N, respectively, lower than the ultimate failure load. The SPL endured the largest injury, while the injuries to the SCM and TRP were relatively small. This is a preliminary study to assess the cervical muscle of driver during a frontal vehicle collision. This study provides a foundation for investigating the muscle response and injury in sled test environments, which can lead to the improvement of occupant protections.


PubMed | Jilin University, Wayne State University and Changan Automobile Holding Ltd.
Type: Journal Article | Journal: Traffic injury prevention | Year: 2016

A drivers instinctive response of the lower extremity in braking movement consists of two parts, including reaction time and braking reaction behavior. It is critical to consider these two components when conducting studies concerning drivers brake movement intention and injury analysis. The purposes of this study were to investigate the driver reaction time to an oncoming collision and muscle activation of lower extremity muscles at the collision moment. The ultimate goal is to provide data that aid in both the optimization of intervention time of an active safety system and the improvement of precise protection performance of a passive safety system.A simulated collision scene was constructed in a driving simulator, and 40 young volunteers (20 male and 20 female) were recruited for tests. Vehicle control parameters and electromyography characteristics of eight muscles of the lower extremity were recorded. The driver reaction time was divided into pre-motor time (PMT) and muscle activation time (MAT). Muscle activation level (ACOL) at the collision moment was calculated and analysed.PMT was shortest for the tibialis anterior (TA) muscle (243317 ms for male and 278438 ms for female). Average MAT of the TA ranged from 28-55 ms. ACOL was large (531% for male and 523% for female) at 50 km/h, but small (<12%) at 100 km/h. ACOL of the gluteus maximus was smallest (<3%) in the 25 and 100 km/h tests. ACOL of RF of men was significantly smaller than that of women at different speeds.Ankle dorsiflexion is firstly activated at the beginning of the emergency brake motion. Males showed stronger reaction ability than females, as suggested by males shorter PMT. The detection of drivers brake intention is upwards of 55ms sooner after introducing the electromyography. Muscle activation of the lower extremity is an important factor for 50 km/h collision injury analysis. For higher speed collisions, this might not be a major factor. The activations of certain muscles may be ignored for crash injury analysis at certain speeds, such as gluteus maximus at 25 or 100 km/h. Furthermore, the activation of certain muscles should be differentiated between males and females during injury analysis.

Loading Changan Automobile Holding Ltd. collaborators
Loading Changan Automobile Holding Ltd. collaborators