The body to be guided usually is a part of a floating link ,of which not only is the pat of a point p prescribed ,but also the rotation of a line passing through the point and embed . ded in the body .For instance ,the line might represent a carrier link in an automatic machin . ery where a point located on the carrier link has a prescribed path while the carrier has a pre . scribed angular orientation .Prescribing the movement of the bucket for a bucket loader is an . other example of motion generation mechanisms .The path of tip of the bucket is critical since the tip must perform a scooping trajectory followed by a lifting and a dumping trajecto ry .The angular orientation of the bucket is equally important to ensure that the load is dumped from the correct position