Building Robots with LEGO® Mindstorms® NXT

Appendix D. Math Cheat Sheet

Sensors

Raw values to percentage (light sensor):

percentage = 146 - raw value / 7

Raw values to temperatures, in C° (temperature sensor):

C° = (785 - raw value) / 8

Conversion of Celsius to Fahrenheit degrees:

F° = C° x 9 / 5 + 32

Averages

Simple average:

A = (V, +V₂+... +V_n)/n

Weighted average:

A = (V₁xW,+V₂xW₂ + .,. + V_nxW_n) / (W, + W₂ + ... + W_n)

Exponential smoothing:

A_n = (V_n xW, + A_n-1 x W₂) / (W, + W₂)

Interpolation

Linear interpolation: Find the value of the dependent variable Y for a given value of the independent variable X, knowing that for X equal to X_a, Y isY_a, and for X equal to X_b, Y is Y_b.

(Y - Y_a) / (Y_b - Y_a) = (X - X_a) / (X_b - X_a)

Y = (X - X_a) x (Y_b - Y_a) / (Xb - X_a) + Y_a

Equation of the straight line which connects ...