Design Of Driver Status Recognition System Based On Steering Wheel Grip Strength

With the popularity of cars,the number of car drivers has increased rapidly,but the number of all kinds of automobile traffic accidents at home and abroad has increased.Research shows that more than 60% of traffic accidents are directly related to the driver status.Compared with the normal state,the recognition of road information,driving decision and driving behavior of drivers in fatigue state,emotional state and tension state will have certain deviation,which will affect driving safety.Therefore,the research on driver status recognition has become one of the important contents in the field of safe driving.A large number of studies based on video recognition,physiological signals and other test methods to identify the driver’s behavior characteristics in the process of driving,but the complex test means itself has a great impact on driving safety,and the non-contact test method is easy to be affected by external factors,and the test accuracy is poor.The driver’s steering wheel grip characteristics have the characteristics of simple acquisition mode and high signal accuracy.Therefore,this paper designs a set of steering wheel grip force test system to achieve the acquisition of steering signal during driving,and analyzes the driver’s state based on the change law of steering wheel grip force signal.The test results show that the steering wheel grip force system can better predict the driver’s fatigue state and condition The state of being emotional.The main contents of this paper are as follows:(1)Through the steering wheel operation process of the car,the steering grip force is mainly to overcome the wheel return force and assist characteristics,and the direction grip strength acquisition is mainly based on the change of steering wheel grip force on two arms during the turning process.Through the study of time-frequency characteristics and recognition algorithm of grip force signal,the signal characteristics of directional grip force are determined,which provides the basis for the signal.The factors influencing the directional grip strength were analyzed and summarized,and the effects of individual differences,driver status and environmental changes on driver’s directional grip strength were determined.(2)Through the hardware design of flexible force sensor and STM32 microcontroller,the signal of the driver’s left and right hand grip strength is collected.Through the chip intelligent control module to continue to collect sensor signals and compare with the system set value threshold value to identify the driver status.When the set threshold value is exceeded,the chip intelligent control module sends out a signal,the alarm light starts to flash,and the buzzer starts to give an alarm to remind the driver that he is in a dangerous driving state.(3)Through the function design by Real View MDK,the function module mainly includes the program design of operating system,pressure acquisition module,identification and judgment module,buzzer module,alarm lamp alarm module and LED display module.(4)Through the designed directional grip system,the driver is in fatigue driving,turning left and right and facing stress state test.The test results show that the system can judge the driver’s state by detecting the grip strength of the steering wheel.Compared with normal driving,the grip strength of the steering wheel is smaller in fatigue driving,and the grip strength on the left side is smaller than that on the right side.The left grip force of steering wheel in left steering is smaller than that in right steering;the left grip force of steering wheel in right steering is greater than that in right steering;and the left grip force of steering wheel in left steering is less than that in right steering.After the stress,the grip strength of the left and right sides of the steering wheel changed significantly,and the grip strength of both sides exceeded the range of normal driving.The driver state recognition system based on steering wheel grip strength is designed in this study.Through the collection and summary of the characteristic signals of directional grip force in different driving states,the correlation between driver characteristics and directional grip strength is proposed,which provides an important reference for driving safety research.