Force feed back manipulator with six degrees of freedom

A manipulator having six degrees of freedom comprising:

• a moving plate having three moving points arranged with substantial equal angles therebetween;
• a fixed plate having three protruding portions arranged with substantial equal angles therebetween, the fixed plate being positioned under the moving plate and being spaced apart from the moving plate;
• three frames rotatably mounted on the protruding portions, respectively, each frame having a first fixed point and a second fixed point located opposite said first fixed point;
• and
• three universal joints mounted beneath the moving plate, corresponding to the three moving points, respectively;
• three rack gear sets, each rack gear set having a pair of rack gears hinged to one of said three universal joints;
• three pinion gear sets, each pinion gear set being associated with one of said three frames to provide an associated frame and one of said three rack gear sets to provide an associated rack gear set, each pinion gear set includes a first pinion gear positioned on said first fixed point of said associated frame and being engaged with one of said pair of rack gears of said associated rack gear set, and a second pinion gear positioned on said second fixed point of said associated frame and being engaged with another of said pair of rack gears of said associated rack gear set;
• and
• three shaft encoder sets, each shaft encoder set includes:
• a first shaft encoder having a first encoder gear engaged with said first pinion gear of one of said pinion gear sets to provide an associated pinion gear set, said first shaft encoder detects a distance variation between one moving point and said first fixed point of said associated frame in accordance with a rotation of said first pinion gear of said associated pinion gear set when the moving plate moves, and
• a second shaft encoder having a second encoder gear engaged with said second pinion gear of said associated pinion gear set, said second shaft encoder detects a distance variation between said one moving point and said second fixed point of said associated frame in accordance with a rotation of said second pinion gear of said associated pinion gear set when the moving plate moves.