t is time in seconds. Other approximating functions z = f(tz) may be used if their adequacy Note 2: is proven. 3. Calculate the deceleration j in revolutions per second squared (s-2) by the formula: Where: is the angular speed in revolutions per second (s-1). ω For the case Un = 80 km/h; = 22.222/Rr (or R). ω For the case Un = 60 km/h; = 16.666/Rr (or R). ω 4. Estimate the quality of approximation of measured data and its accuracy by parameters: 4.1. Standard deviation in percentages: 4.2. Coefficient of determination Where: The above calculations for this variant of the deceleration method for Note 3: tyre rolling resistance measurement can be executed by the computer program "Deceleration Calculator" downloadable from the WP.29 website as well as any software which allows the calculation of nonlinear regression.
t is time in seconds. Note 2: Other approximating functions z = f(tz) may be used if their adequacy is proven. 3. Calculate the deceleration j in revolutions per second squared (s-2) by the formula: Where: ω is the angular speed in revolutions per second (s-1). For the case Un = 80 km/h; ω = 22.222/Rr (or R). For the case Un = 60 km/h; ω = 16.666/Rr (or R). 4. Estimate the quality of approximation of measured data and its accuracy by parameters: 4.1. Standard deviation in percentages: 4.2. Coefficient of determination Where: Note 3: The above calculations for this variant of the deceleration method for tyre rolling resistance measurement can be executed by the computer program "Deceleration Calculator" downloadable from the WP.29 website as well as any software which allows the calculation of nonlinear regression.