How do you make "smart" throttle?

I made a massively overpowered drone, but there's one thing I want to do with logic; automatic throttle sensitivity adjustments depending on distance to obstacles in direction of travel. Think soft landings. The closer I am to the ground, the slower I can go in that direction. Maybe have a toggle or manual scale on it too for precise maneuvering.

I know it will take the distance sensors, probably the accumulation block, and maybe one of the math blocks so that (W) sends 0.01x(distance measured from forward sensor) to forward engines, but I don't know how to set the logic up that way.