Controlling the individual speed of mecanum wheels within the main programme

[Ether]

You need to find the max absolute value, since speeds can be +/-.

Let fr, fl, rl, and rr be the 4 wheel speed commands in the range +/- 1. Then here's the pseudo-code:

max=fabs(fr);
if (max<fabs(fl)) max=fabs(fl);
if (max<fabs(rl)) max=fabs(rl);
if (max<fabs(rr)) max=fabs(rr);

if (max>1){fr/=max; fl/=max; rl/=max; rr/=max;}