nope, encoders are definitely fundamental. You cannot give a DC (brushed or not)...

dekhn on Jan 22, 2018 | parent | context | favorite | on: I am a roboticist in a cheese factory

nope, encoders are definitely fundamental. You cannot give a DC (brushed or not) motor voltage and have it turn a fixed distance. The closest thing is steppers, but once they stall, you've lost feedback and positioning information.