Research On Seated Reach Biomechanics And Difficulty

Improving the Drivers’ comfort will release the driving fatigue, so that the trafficaccidents caused by fatigue will be probably reduced. The drivers often stretch to thebuttons on penal, while driving. If the buttons were layout in the region that thedrivers can easily reach, their fatigue will be released and they will be moreconcentrated on driving, so that that the traffic accidents will become less. Therefore,researches are of great significance for the design of operation, which are about themechanisms of reaching difficulty and describing the operating comfort objectively.The source of this subject is based on the frontier and interdisciplinary study,aiming at studying the mechanisms of reaching and making the reference for theoperation region design and its comfort assessment. At the same time upper-limbextremity prediction and reach comfort models are worked out through the regressionanalysis of human dimension and subjective assessment.The mechanism of reaching difficulty is studied by using the biomechanicalcalculation software Anybody. The development platform of complete bio-mechanicalhuman model exits in the Anybody, which is Anybody Modeling System (AMS). Thereaching bio-mechanical human models are set, in which the reaching posture issimulate by the muscular-skeleton models built in AMS. The different reaching targetsare set depending on the design of experiments. The biomechanical parameters arestudied when subjects stretch to different targets. By analyzing the data gained fromthe experiments, the reach comfort models are acquired. The whole study of thispaper can be concluded as follows.Firstly, the reach bio-mechanical models are built by using the muscular-skeletonmodels in Anybody, in which the dimension and posture of the models are adjustedaccording to the experimental data, including stature, weight, BMI, etc, in order toensure the accuracy of models. Secondly, the biomechanical parameters are studied when changing with thedifferent targets. The parameters that possibly influence the reach difficulty areselected, such as maximum muscle activity, joint moment (shoulder joint, elbow joint,hip joint, etc.) and the muscle activity and loads of latissimus dorsi (muscles on theback), deltoid (muscle on the upper limb). The varying trends of these parameters arestudied under the conditions that one subject reaches different targets and manysubjects reach the same targets.Thirdly, the main factors that influence the reaching extremity are gained throughthe factor analyzing. The upper-limb extremity prediction model and reach comfortprediction model are carried out by using the mean factors. The accuracy of themodels is tested by ROC AUC (Area Under the Curve) and the models with highaccuracy are acquired.Finally, the reach difficulty subjective assessment is analyzed by means of theobjective measures. The relationships among the anthropometry, target coordinates,biomechanics with assessment are studied. The factors that are related with reachdifficulty are worked out, such as the distance of targets, joint moments, etc. Theresearch methods are set combining with both subjective and objective measures.