Lately, the calling for equality between women and men inopportunities was spread at wide range. According to theAmerican Trucking Associations; about seven percent of truckdrivers are women. They increased worldwide up to 400,000 by the end of 2017.
More women have taken the wheel day byday 107.Truck driving is hard work as the road can be tiring and the body of pregnantwoman is a extremely sophisticated dynamic system that is sensitive towhole-body vibrations in a sitting posture, so the surrounding environmentshould be facilitated andadapted to give the pregnant woman adequate level of comfort to herself and herfetus to save their life.Many researches have been assigned for vibration effects onsitting for non-pregnant persons.
However, seated pregnant women are out of interest.Qassem and Othman model is the first analytical study of the effects of vibrationson seated pregnant women. Based on their earlier research investigatinghorizontal and vertical vibration responses of seated human males, The pregnantwoman mathematical model was investigated .They used the same physical properties;spring constants and damping coefficients.
Moreover, for a pregnant model, itwas assumed that the mass increase due to pregnancy was distributed on thethorax and abdomen at the same ratios with their masses. 108In general,Suspension systems are classified into three major categorizations; passive,active and semi-active. Passive suspensions using oil dampers are simple,reliable and cheap, but the performance has some limitations. Active andsemi-active suspensions have control algorithms which force the system to enhancethe ride quality and damp vibrations to safety levels.
Semi-activesuspension systems can enhance performance over a wide-ranging of frequencycompared with passive systems. The research of semi-activeseat suspensions widely introduces advanced control approaches or appliesappropriate actuators to enhance the ride comfort considering load variation,actuator saturation, time delays, and reliability, etc. A thirteen degrees–of–freedom (DOF) seat and pregnant woman body model is used where the seatconsists of frame and cushion and the human body consists of head, neck, upperarm, lower arm, torso, Thoracic spine, thorax, diaphragm, abdomen, lumbar spineand pelvis. The control performance criteria are estimated by differentparameters such as seat frame distance, cushion displacement, fetusacceleration and head acceleration.
The pregnant woman body is eleven DOF formore accuracy.