Testing And Analysis For Driving Vibration Comfort Of Tractor Based On Human Physiological Response

Driving vibration comfort of tractor is closely related to the driver’s physical and mental health and work efficiency.The vibration shock of the seat during the field operation is large,and the driver’s long-term work will reduce the work efficiency,increase the operation error,increase the probability of accidents,and seriously threaten his physical and mental health.Based on the vibration comfort of the tractor driving,combined with the field and indoor simulation vibration test,based on the measurement of human physiological response,using the regression analysis and subjective psychological scale,the vibration comfort of the human body was tested and analyzed.By measuring the vibration signal of the cab chassis when the tractor is working on the typical ground in Lingnan area,the specific representative vibration displacement characteristics are extracted as the vibration excitation input of the six-degree-of-freedom electric platform.Through the indoor simulated driving vibration experiment,the Ergo LAB human-machine environment synchronization system was used to obtain three physiological responses of the electromyogram,electrocardiogram and photoplethysmographic pulse wave of the subject for 120 min,and 13 characteristic indexes of the three signals were further extracted.The mean within the equal time period and linear regression analysis of each indicator.In this process,the psychological scale method was used to simultaneously carry out the questionnaire survey of subjective comfort of the subjects,and the subjective evaluation and objective physiological response were used to discuss and analyze the vibration comfort of tractor driving.The study found that the 13 characteristic index values and accumulation time of the three physiological response signals under the vibration state showed a certain linear trend,but only the mean value of the EMG signal and the mean interval of the ECG signal.The linear relationship between the five indicators of the amplitude and root mean square of the photoelectric volume pulse wave signal and time is significant.The discomfort of the subjects was generated after about 40 min of vibration,and then gradually accumulated and aggravated;and the mean value of the EMG signal and the amplitude of the pulse wave signal in the three optimal indexes of the objective physiological response were two root mean squares.After the index changes to a certain threshold with time,it tends to be flat after 40 min and 90 min respectively.The mean period of cardiac signal of ECG signal rises steadily in the early stage,and it fluctuates greatly after 90 min.The results show that some characteristic indexes of physiological response signals can timely and accurately reflect the physiological state of the human body suffering from tractor vibration,and can identify the uncomfortable state of the human body in advance,which can be used as the basis for objective evaluation of tractor vibration comfort.The test method of tractor driving vibration comfort based on human physiological response signal can provide an effective way for the evaluation of the damping effect of the tractor driving seat suspension mechanism.