The windscreen wiping system is mandatory requirement for automotive vehicle as per Central motor vehicle rules (CMVR). The main scope of the standard is to ensure vision zones to be wiped by wiping system to ensure maximum field of vision to the driver. The evaluation of vision zones as per IS 15802:2008 is generally determined by virtual simulation by OEMs. The limitation of virtual simulation is due to actual tolerances in vehicle, due to seat fitment, ergonomic dimensions, seat cushioning effect and wiper non-effective operation which are not taken into consideration very well off. The testing methodology described in the paper is an in-house developed test method based on SAE recommended practices. With the help of 3D H-point machine and a laser based ‘Theodolite’ equipped with horizontal and vertical angle projections from single pivot point is used to develop various vision zones on an actual vehicle windscreen as per technical data. These zones are later compared with wiped area to evaluate field of vision. The standard is applicable to vehicle other than M1 category viz M2, M3, N1, N2 and N3. Critical vehicle parameters such as SgRP (seating reference point), seat back angle and AHP (accelerator heel point), seat travel, GVW (gross vehicle weight) and category of the vehicle are required.
The paper clearly describes calculation steps for calculating Automotive tool reference line, equation for Eye ellipse, placing eye ellipsoide centroid coordinates with respect to VCS (vehicle coordinate system) in vehicle ecosystem, projecting Ellipse tangents for distinct vision zones and evaluating mandatory standard requirement of percentage of wiped area with respect to vision zones at vehicle level. The work scope in this paper will enable manufactures to validate the virtual simulation results with respect to actual vehicle considering all tolerances. This test method can be adapted widely to evaluate more precise test results and data for field of vision certification activity.