Study On Vehicle Emergency Call Technology And Vehicle Crash Severity Assessment

Current status of traffic accidents emergency rescue in our country has a huge gap with the developed countries, mainly reflecting in the following aspects: lack of systematic teatment approaches for traffic accidents; do not have a comprehensive emergency rescue system; the professional level of medical team is low; rescue facilities is insufficient etc. Aiming at backward status of domestic emergency rescue, foreign research results were analyzed to study on vehicle accidents emergency call technology and vehicle accident severity assessment.Main users and requirements of information in vehicle accidents emergency call system were analyzed.In order to realize the information requirements of the main users, the composition of vehicle accidents emergency call system structure was introduced, the goal of accidents severity assessment research and the system general framework were proposed.Vehicle body collision damage evaluation index, human body injury mechanism, head injury criteria, chest injury criteria and lower limb injury criteria etc, were introduced. The relation between injury risk and head injury severity index, chest injury severity index and lower limb injury severity index etc, were analyzed. Its application in vehicle accidents emergency call system was introduced.Vehicle body collision damage evaluation model was introduced, the relationship between vehicle collision damage and collision speed was aquired based on the model. Lamella mechanics theory about thin plate was described in brief, an approximate method of solving the problem of thin plate's vibration--the galerkin method was introduced in detail, and the problem of windshield vibration impact by the head of occupant in vehicle front row was solved with the method, the approximate natural frequency of windshield was obtained. According to related knowledge of composite mechanics and vibration dynamics theory, dynamic model of occupant head impact with windshield in vehicle frontal crashes was built, the frequency characteristics of human head impact acceleration and windshield deformation were obtained, key factors influence the injury severity of the occupant head were analyzed.On the basis of collecting statistical data of the vehicle accidents, various types of motor vehicle accidents and its characteristics were summarized, it's convenient for gasping the emphasis of vehicle accidents analysis and more pertinent to study on vehicle accidents.The principles, calculation method and main characteristics of the PC-Crash software were introduced. According to the parameters of a case, vehicle frontal collision model was established by PC-Crash software and simulation analysis was performed. Car occupant kinematics and dynamics response in vehicle frontal impact were studyed, the kinetic parameters relating to human injury severity and occupant head injury index HIC, value of chest acceleration in 3 ms, etc, were analyzed. Through comparing simulation result and experimental result, we know that PC-Crash simulatin analysis using vehicle and occupants' model established according to actual parameter is an effective approach in vehicle accidents injury mechanism study.By using security components simulated collision test system, simulated collision test under speed of 20 km/h and 30 km/h were conducted respectively according to GB 14166-2003, sled acceleration signal was measured and vilocity change during the impact process was calculated by Labview software. Experimental results show that using velocity change as the index of accidents injury severity in vehicle accidents emergency call system is feasible.Decision-making process of vehicle accidents emergency call was designed, vehicle accidents emergency rescue implementation process and approaches were described, thus the general framework of vehicle accidents emergency call system was established, and the practice of one case in the framework was analyzed, application of velocity change information obtained from acquisition and processing of signals during crash was explained.The vehicle accidents injury severity assessment model and general framework of vehicle accidents emergency call system established in the thesis provides theoretical foundation and information platform for vehicle accidents emergency rescue. Members of medical team can grasp accidents time, location, injury condition of vehicle and wounded person according to emergency call information, this make assurance to the successful implementation of vehicle accidents emergency rescue, provides precious time for emergency reatment of wounded persons.