Research On Rollover Warning System For Light Forest Fire-Fighting Truck Based On TTR

Forest fire truck is an important carrier to carry out disaster relief tasks,and its performance directly determines the level and efficiency of the rescue work.Because forest fire truck is a special kind of forestry vehicle,it has a certain cross-country performance to meet the requirements of forest area operation,so its centroid position is on the high side.The higher the center of mass,the greater the risk of rollover..In view of the fact that the electrification level of forest fire trucks is generally not high,additional sensors are needed to acquire the real-time parameters of the vehicle.Based on the combination of TTR algorithm and inertial navigation technology,comprehensive analysis and Research on rollover warning of light forest fire trucks are carried out by means of model theoretical calculation,computer simulation and dynamic rollover stability test.Firstly,a forest fire truck rollover warning algorithm based on TTR(Time to Rollover)is used.The real-time roll angle and roll rate of the forest fire truck are taken as input variables of the algorithm.The dynamic LTR(Lateral-Load Transfer Ratio)of the forest fire truck is taken as the rollover judging index.The |LTRMAX |=0.8 is set as the rollover judging threshold value,TTR=1s is the main warning threshold value.At the same time,the rollover judging threshold value is set as TTR=1s.When the angular rate is zero,LTR=0.8 is used as the threshold value of auxiliary warning.Secondly,the dynamic model of forest fire truck is established in CarSim software,and the early warning algorithm is built in Matlab/Simulink environment.The joint simulation of CarSim and Matlab/Simulink is carried out for typical fishhook steering and double-line-changing steering and satisfactory results are obtained.Finally,a rollover warning system based on the inertial unit MPU6050 and STM32 is developed independently,and field tests are carried out under snake-shaped,steady-state and fishhook-steering conditions according to the national standard GBT 6323-2014 and the regulations of 49CFR Part575 of the United States.The results show that the rollover early warning system can achieve rollover early warning by using as few sensors as possible to obtain vehicle parameters,and the roll angle and roll angle rate obtained are accurate.The rollover early warning time obtained by rollover early warning algorithm is reliable and real-time,which can assist drivers to judge rollover risk and improve the active safety of forest fire engines.