I'm working on a next-generation solar car and am investigating electro-mechanical braking.
Reasons are numerous but include the ability to integrate ABS for maximum effectiveness of brakes and to preven tspectacular results during vehicle performance testing at scrutineering. :-)
The approximate actuator force required is 2kN if the numbers on the back of the envelope are right.
Low power consumption and mass are primary constraints; after the obvious safety one!
A geared motor with worm drive uses no power unless it's moving, so that's good.
Coils will require much more current but can act faster.
I'm open to suggestions as to the type of actuator to use.
Force feedback on the pedal would be wasteful of energy. I'm thinking of using accelerometers to measure actual deceleration and match that to the pedal position by varying the braking force; at least until the onset of brake lockup.
A progressive spring on the pedal should give enough "feedback"; though I can imagine using the dive under braking to increase the base return force at the pedal.