Research On Driving Posture Comfort Based On Subjective Evaluation And Biomechanical Simulation

Driving posture comfort is an important consideration in designing an ergonomic vehicle.Currently,a method is needed to evaluate the "in-body effects" and "perceptual effects" in driving posture comfort.Many scholars have tried to characterize the "in-body effects" with biomechanical parameters,and to characterize the "perceptual effects" with subjective evaluation At the same time,a large amount of literature has proven that driving posture is affected by the differences in the cab environment and body size.Therefore,it is of great significance to study the differences and correlations of driving posture,biomechanical loads,and subjective evaluation under the influence of different experimental independent variables,and to explore the driving posture selection mechanism from the perspective of biomechanical load,and then establish an evaluation model of discomfort.These studies are of great significance for improving the design of driving posture comfortIn this thesis,the subjective rating scores of driving posture comfort,the cab layout parameters,the human body size and the biomechanical load were obtained through the driving posture experiment on the human-machine test mockup,as well as by AnyBody biomechanical simulation.Using statistical methods such as significance test and correlation analysis,the driving posture selection mechanism was studied from the two aspects of layout parameters and driving posture.Finally,the possible lower-limb / upper-limb driving posture selection mechanism was summarized,and an evaluation model of discomfort was established.In this thesis mainly the following specific studies were carried out:(1)Data acquisition based on experiments and simulations.The comfort / discomfort driving posture experiment was performed on the human-machine mockup,through which the subjective evaluation data and joint angles were obtained.A biomechanical simulation platform based on AnyBody was established,which was as consistent as possible with the actual experimental results.Four kinds of parameters of biomechanical loads,such as the muscle force,the muscle activation,the joint reaction and the joint torque,were obtained by simulation.(2)The driving posture selection mechanism was studied.Using statistical methods such as significance test and correlation analysis,supplemented by various forms of charts,the connections and differences between joint angle,biomechanical loads,subjective score were found.Based on the results of data analysis,from the perspective of layout parameters,the influencing factors and changing rules of lower limb / upper limb driving posture were found,and the changes of biomechanical loads and subjective scores with driver's actual riding position were emphasized.From the perspective of driving posture,lower limb activation / upper limb muscle force were selected to represent the lower limb / upper limb bioburden status,respectively.The comparative analysis of the changes of lower limb activation degree / upper limb muscle strength,lower limb total score / upper limb total score with lower limb / upper limb joint flexion and extension angle,and then summarizes the possible lower limb / upper limb driving posture selection mechanism: It is difficult to drive near the extreme joint angle,even if the muscle load is low,the human body can not assume that it is a comfortable driving posture,not to mention the high muscle load.Near the most comfortable joint angle,it is basically no problem to complete the driving task.The activation degree of lower limb muscles tends to be the minimum,and the muscle force of upper limbs tends to be medium or minimum.(3)Discomfort modeling.Based on the characteristics of subjective evaluation data,a method for defining discomfort is proposed.The modeling ability of the biomechanical indexes were compared.A discomfort evaluation model of lower / upper limbs based on layout parameters and muscle load was established,and analyzed and validated from the model characteristics and kinematic meaning.In this thesis,a biomechanical simulation experiment platform is established for driving posture.The driving posture selection mechanism was explained by the characteristics of the biomechanical loads from the two aspects of arrangement parameters and joint angles.In the future,further quantification of this driving posture selection mechanism will make it possible to form a quantitative driving posture comfort evaluation index,which will help to judge subjective comfort more objectively and accurately,help shorten the subjective evaluation process,and improve driving posture comfort Design efficiency.