The motion dexterity of a device is defined as the ratio (the number of degrees of freedom in the device)/(the motion resolution of the device). The force dexterity may be defined as (the number of degrees of freedom in the device)/(the force resolution of the device). Given a situation where both types of dexterity mean the same thing and a situation where the two terms mean different things, outline how force dexterity of a device (say, an end effector) can be improved by using tactile sensors. Provide the dexterity requirements for the following tasks by indicating whether motion dexterity or force dexterity is preferred in each case:
(a) Gripping a hammer and driving a nail with it
(b) Threading a needle
(c) Seam tracking of a complex part in robotic arc welding
(d) Finishing the surface of a complex metal part using robotic grinding