In one embodiment, a robotic surgery system comprises a handheld manipulator configured to be manually moved in a global coordinate system relative to the bone, the handheld manipulator comprising a bone cutting tool comprising an end effector portion, a frame assembly, and a motion compensation assembly movably coupled to the frame assembly and bone cutting tool. A controller may be operatively coupled to the manipulator and configured to operate one or more actuators within the frame assembly to cause the motion compensation assembly to automatically move relative to the frame assembly to defeat aberrant movement of the bone cutting tool that would place the end effector portion of the tool out of a desired bone cutting envelope that is based at least in part upon one or more images of the bone, while allowing the bone cutting tool to continue cutting one or more portions of the bone.
