Charging based on the infraction does punish poor people more than rich people if you look at how significant the fine is to the person.

Person A makes $10 * 40 hours / week -> $400 / week -> $100 ticket == 25% of weekly gross income

Person B make $100 * 40 hours / week -> $4000 / week -> $100 ticket == 2.5% of weekly gross income

Who is being hit harder? Who will be more deterred from future speeding?

Furthermore, the "robot overlords" won't care if someone is "rich|poor|black|white|smart|dumb". Can you say the same for a police officer?