Door control system

A vehicle door control system for a vehicle having a vehicle body and a vehicle door, comprising:

• a housing;
• a pushrod having a first end that is connected to one of the vehicle body and the vehicle door;
• and
• a locking device at least a portion of which is mounted to the other of the vehicle body and the vehicle door, wherein the locking device includes a locking device leadscrew, a locking device leadscrew nut mounted on the locking device leadscrew, a locking device housing including a locking device leadscrew nut guide path, and a locking device leadscrew brake,
• wherein the pushrod has a second end that is connected to the locking device leadscrew nut, wherein the locking device leadscrew nut is constrained against rotation but is slideable along the locking device leadscrew nut guide path by movement of the pushrod, which causes rotation of the locking device leadscrew, wherein the locking device leadscrew brake is positionable in a braking position in which the locking device leadscrew brake prevents rotation of the locking device leadscrew, and a release position in which the locking device leadscrew brake permits rotation of the locking device leadscrew,
• wherein the locking device leadscrew brake includes:
• a plurality of plates which are interleaved with a plurality of discs, wherein the plurality of plates are non-rotatable relative to the housing but are translatable relative to the housing, wherein the plurality of discs are connected to the leadscrew, and
• a motor having a motor output shaft, wherein the motor output shaft is rotatable in a first direction to increase compression of the plates and the discs so as to increase a frictional force that prevents rotation of the leadscrew, and wherein the motor output shaft is rotatable in the second direction to reduce compression of the plates and the discs, so as to decrease the frictional force that prevents rotation of the leadscrew, wherein the motor is controllable to modulate the frictional force that prevents rotation of the leadscrew.