The first half was played with a strong wind, and heavy rain affecting play.
Robson-Kanu scored first for Swindon on 32 minutes with a good goal.
The lead didn't last long as within a minute Cheltenham had equalised with a goal by Elvis Hammond.
Hammond then scored again from close range to give the Gloucestershire side the lead on 54 minutes.
Sub Kevin Amankwaah equalised on 64 minutes with a good header to make it 2-2.
Overall a good game, and a draw was a fair result, but this is the sort of game Swindon need to start winning if they are going to get themselves out of trouble.