Surgical robot with secondary brake release for user actuation

A medical robotic system comprising:

• a joint comprising:
• a first portion;
• and
• a second portion moveable relative to the first portion and configured to be coupled to a tool;
• a brake mechanism configured to selectively limit motion of the joint, the brake mechanism comprising:
• a braking material engageable between an engaged configuration and a disengaged configuration, wherein in the engaged configuration the braking material limits a movement of the second portion of the joint relative to the first portion of the joint, and in the disengaged configuration the braking material permits the movement of the second portion of the joint relative to the first portion of the joint;
• a first electromagnetic assembly comprising a first coil, wherein the first electromagnetic assembly is configured to disengage the braking material from the engaged configuration to the disengaged configuration when the first coil is energized;
• and
• a second electromagnetic assembly comprising a second coil, wherein the second electromagnetic assembly is configured to disengage the braking material from the engaged configuration to the disengaged configuration when the second coil is energized, and the second coil is electrically independent from the first coil;
• and
• a user-commanded release mechanism comprising a release actuator and a mechanical input coupled to the release actuator, the mechanical input operable to move the release actuator independent of the first electromagnetic assembly and the second electromagnetic assembly, the movement of the release actuator disengaging the braking material from the engaged configuration to the disengaged configuration independent of the first electromagnetic assembly and the second electromagnetic assembly.

A method of operating a medical robotic system, the method comprising:

• energizing a first coil of a brake mechanism coupled to a joint to permit a movement of a second portion of the joint relative to a first portion of the joint;
• energizing a motorized actuator to move the second portion of the joint relative to the first portion of the joint;
• deenergizing the first coil of the brake mechanism to engage the brake mechanism and to limit the movement of the second portion of the joint relative to the first portion of the joint;
• and
• releasing the brake mechanism via a release actuator and a mechanical input to permit the movement of the second portion of the joint relative to the first portion of the joint, the mechanical input coupled to the release actuator, the brake mechanism being released upon actuation of the mechanical input that moves the release actuator without energizing the first coil of the brake mechanism.