Research On Identification And Monitoring And Early-warning For Truck Statues

With the rapid growth of the national economy, China entered the period of rapiddevelopment and growth of road transport industry. Because of the lack ofdevelopment experience and the supervisory ability of the relevant departments, thedomestic situation of traffic safety is becoming increasingly serious. In recent years,vicious traffic accidents with heavy casualties happen frequently. According to thestatistic, the percentage of the casualties of traffic accident caused by trucks is higherin China. The problem of the transportation safety has been one of the key issueshurry to be resolved.Traffic accident prevention, early warning and emergency treatment technologyhave been emphasized specifically in national medium and long-term developmentplan of science and technology. The new technology of security monitoringtechnology and equipment also have been listed as the national key technology todevelop in traffic safety technology plan of action in2008.,“key technology anddemonstration in transportation” had gradually carried out in the provincesas as theNational Twelfth-Five-year Plan in2011. In view of the continually serious roadtransport situation, European Community in lead of German, American and Japan, inwhich the vehicle industry developed greatly, have managed to do a good deal ofresearch in security dynamic monitoring and early warning. And combining with carnetworking technology, these counties have made great progress in vehicle statusreal-time monitoring and early warning and vehicle-road coordinate system. Thisshows that the monitor technology and the risk early warning of vehicle status havebeen the primary subject in terms of the vehicle safety all over the world. Themonitoring and early warning of truck have been priority among many importantresearches. Vehicle risk identification technologies, as the basis of monitoring andearly warning, was hot spots and advancing of vehicle safety research.Combining with the requirement of the vehicle safety monitoring technology andequipment and relying on National High-tech Research and Development Projects(863), this paper focuses on method of vehicles risk status identification. Primarily,several kinds of typical risk states which lead to traffic accident were analyzed, thevehicle state parameters which need to be detected had been determined. And sensorswere installed on the medium-sized truck produced by FAW CA1169PK2L2EA80.The corresponding vehicle state parameters’ information were collected by using vehicle terminal microcontroller; Secondly, the data collected by the sensors wereanalyzed and a method to judge vehicle risk status was proposed based on singleparameter; Thirdly, the vehicle suspension vibration characteristics and vehiclestopping distance calculation model were researched, a method to identify the vehiclerisk of loading state and braking state based on multi parameters were described inthis paper; Finally, vehicle risk state monitoring and early warning simulation systemwhich used FAW truck as model was established based on virtual instrument software,The system could complete the simulation of vehicle failure preset and laboratoryexperiment of vehicle risk state monitoring and early warning. it also reserved abilityof parameter editing permission and real-time inputing signal which were collectedfrom the vehicle state sensors to meet the requirements of real-time monitoring intransit and laboratory simulation of vehicle risk states early warning. The researchprovides the theory basis for the threshold value setting of truck risk statesidentification and early warning. it supplies PC software programs and laboratorysimulation research platform for the exploration of on-board vehicle monitoring andearly warning system. The main work of this paper includes the following aspects:1. Analyse on the vehicle risk state and the running state information collectingThe typical risk factors such as overspeed, overload, lacking of drivinglongitudinal space, mechanical fault and tire burst which all could trigger trafficaccident were analyzed in systematic. Based on analysis the state parameters such asbreak line pressure, the temperature of brake shoe, shoe wear degree of break system,the state of brake lamp and steering lamp, the temperature and pressure of tires,vehicle load status and speed of vehicle which could trigger malignant trafficaccidents were decided to acquire. Information of the parameters mentioned abovewere captured through installing the sensors on the FAW truck,, and signal datacaptured from sensors was saved by vehicle terminal microcontroller.2. Study on the method of the risk state identification based on single parameterThrough the analysis of the characteristic of vehicle sate parameters informationfrom sensors, and combining with the need of the test vehicle structure performanceand the influence of the driving situation (the road condition and the weather), themethod of judge vehicle in risk states(speed of vehicle, tires temperature and pressure,brake lamp and steering lamp, brake shoe temperature,shoe wear degree) based onsingle parameter mentioned above was proposed in this paper and the threshold valueof risk state of all parameters were determined. 3. Study on the multi-parameter risk identification method based on suspensionvibration characteristicsIn this paper the two degree-of-freedom rear suspension vibration model wasestablished, using road irregularities as incentive input, the relationship between thevehicle suspension stroke and the suspension dynamic loads was analyzed underdifferent driving speed and different loading status. a method of calculation of vehicleload status was proposed by measuring suspension deformation; Based on this method,guyed load status detection device with overload protection was development. AndLevenberg-Marquardt and EMD method were used to deal with the signals of the loadstatus sensors, feasibility and practicability of two methods were analyzed and EMDmethod was determines to process dynamic load signals; Combining with the roadcondition, vehicle speed and load state parameter information, a method of judgingrisk load status as unbalance loading and fall off and slip of the goods was proposedby locating of horizontal center of mass; Detection test of load status and monitoringtest of locating horizontal center of mass were carried on by using the laboratoryvehicle on A-level road and eight kinds of special road under different vehiclecondition(speed and load state), the error of the test result is less than5%, the testrealizes the measurement of the location of horizontal center of mass and verifies theaccuracy of load state detection and the feasibility of monitoring the location ofhorizontal center of mass.4. Study on the multi-parameter risk identification method based on stoppingdistance.The analytical model for stopping distance was established in this paper, mainfactors which influence stopping distance such as driver factors, vehicle stateparameters, brake structure parameters and road condition were researched; Based onthe analysis and calculation of the driver braking reaction time, the work time ofbrake, brake line pressure, the temperature of brake shoe and coefficient of roadadhesion which influence the brake distance, the stopping distance calculationformula was established based on braking mechanics analysis; The internal andexternal resistance parameters of vehicle stopping distance model were fitting inneutral idle and coasting test. Finally, simulation test and real vehicle braking test wasconducted under different work condition, accuracy and feasibility of the stoppingdistance calculation model was verified in test results.5. Design of vehicle risk state monitoring and early-warning software system. The vehicle risk state monitoring and early warning system was developed basedon virtual instrument software, it contains front panel (human-computer interactioninterface) and program diagram. program work includ input driving state information,identification of risk state based on single parameter and multi parameters, monitoringresult display and early-warning. The program of input vehicle driving stateinformation reserves three ways to obtain signal, real-time input from data acquisitioncard, input information from database, and input simulation signals. The ways thatinput from database and simulation can carry out the laboratory simulation test ofpreset vehicle risk state, and the real-time input module of serial signals can also asthe host computer procedure of whole system continue to develop.In conclusion, the methods of truck risk state identification were studied and amonitoring and early-warning software system for truck risk state was developed inthis paper, it supports a new method to monitor and early warn about the vehicle riskstate in transit, and has significant social contribution and application value to preventtraffic accident caused by truck.