ADVANCE METHOD OF MEASURING TCD "TURNING CIRCLE DIAMETER" FOR VEHICLE

Turning circle diameter (TCD) of vehicle is critical parameter which is used to determine the turning capability of vehicle. TCD is the smallest circular turn that a vehicle can make of given drive track. The TCD mainly depends on vehicle wheel lock angles, wheelbase, and geometric architecture of vehicle. The Regulation certification requirement of steering system, states that the maximum TCD should be less than 24m & TCCD 25m (M&N category). (IS 12222:2011 & R79). This invention relates to measuring the TCD of vehicle Vehicle's TCD is measured in plenty of open space. Road wheel is steered to full lock condition either in left or right and driven at low speed. Outer side wheel mark is traced on ground with help of chalk, or some other means and final trace mark is measured with tape from center. This is popular and most used TCD measurement, this process involves lot of manual intervention, time consuming, safety concern and has more room for error. Our proposed solution : The rotation sensors and position sensors will be mounted on vehicle using suitable fixtures. The datum for vehicle position is kept at appropriate place where the test is going to happen such that it identifies the position of vehicle. Vehicle road wheel is steered to full lock condition either in left or right and vehicle is driven at low speed from start position to end position in circular manner for one full round. The rotation sensor counts the total number of wheel rotation during vehicle start position to end position. The position of vehicle is identified using the help of position sensor and datum. The controller then calculates the TCD based upon the sensor's outputs and tyres details. It displays the result in mobile through mobile app. The TCD is calculated by simple basic concept of measuring the distance travelled by wheel for one complete round of vehicle. Distance travelled by wheel is nothing but tyre circumference multiplied number of turns of wheel. Our proposed invention overcomes and address the below limitations.  It provides accurate and precise results by adjusting room for error. It eliminates the approximation ambiguity.  It reduces the manual intervention of human effort to carry out the entire measurement process  It improves the safety of measurement technician, since it involves mounting of sensor during vehicle static condition and don't need to trace the vehicle outer position using chalk as per current measurement method.