Research On Seat Comfort Evaluation Of Standing Seat Based On Human Pressure Distribution And EMG Signal

In order to improve the comfort and safety of the ergonomic seat,and effectively reduce the harm to the human body by sitting for a long time,the innovative design of the seat-stand support structure of the ergonomic seat came into being.The research on the comfort analysis method of the standing seat carried out in this work has important theoretical significance and engineering value for studying the fatigue parameters of sitting and standing posture,reducing the hazards of sedentary sitting,and improving the matching degree between the seat and the task.In this work,to study the biomechanical and fatigue characteristics of sitting and standing postures,an experimental method combining body pressure distribution and surface EMG signalis established,and an evaluation mathematical model is established.Based on this method,the influence of the tilt angle of the chair surface and different work tasks on the comfort of the standing chair is studied.Through the pressure distribution measurement and the surface EMG experiment results,the influence of the pressure data and the surface EMG signal fatigue parameters on the sitting and standing comfort is systematically discussed,and the construction and solving methods of the sitting and standing comfort analysis model are described,and the comfort is established.The degree mathematical model is brought into the experimental data to solve,which verifies the validity of the numerical prediction method and the prediction formula.The main research contents and results of this article are as follows:(1)A method of sitting and standing comfort analysis based on body pressure distribution is established.Through this method,the maximum pressure,average pressure,SPD% and DSPD% values of the buttocks and soles of the feet are compared.Studies have shown that in static sitting posture,computer tasks and writing tasks,the hip and sole indicators are more advantageous when the tilt angle of the chair surface is 20°.However,in the ironing task,many data show that the human body will be more comfortable when the tilt angle of the chair surface is 0°,but there are also a few data showing that the tilt angle of the chair surface is 20° and 40° more advantageous.(2)Established an analysis method of sitting and standing comfort based on EMG signal,adopt wavelet threshold denoising method for preprocessing,and then use MATLAB programming to extract feature values.Analyzing the results of IEMG,RMS,MPF,and MF,it was found that under static sitting posture,computer tasks,and writing tasks,the comfort is highest when the tilt angle of the chair surface is 20°.In the ironing task,the MPF and MF values of all muscles show that it is more comfortable at 0°,but there are a few parameters that show that the tilt angle of the chair surface is 20° or40 °,which verifies the correctness of the conclusion of the body pressure distribution.In addition,it is also found that the erector spinae and gastrocnemius muscles are more comfortable when the tilt angle of the chair surface is 20°,and the lateral femoris muscle is more advantageous when the tilt angle of the chair surface is40°.(3)The mathematical model of seat comfort evaluation is established by using the analytic hierarchy process.Through the establishment of the correlation matrix,the weight coefficient of the influence of each factor of the scheme layer on the sitting comfort is obtained,and the mathematical formula of sitting comfort is obtained.Substituting the experimental data into the mathematical formula of sitting comfort to obtain the calculation result,the comparative analysis found that the calculation result is basically consistent with the experimental analysis result,which verifies the validity of the standing seat comfort evaluation model established in this work.In this work,by carrying out body pressure distribution test and EMG signal acquisition experiment,the result of sitting and standing comfort is obtained,and the mathematical model of this type of seat is established.The shortcomings of this article are the backward experimental equipment and the subjectivity of the analytic hierarchy process.In the future,the research on the comfort of standing seats should be carried out from multiple angles,such as height and material characteristics of the chair surface.