Page 510 - The ROV Manual - A User Guide for Remotely Operated Vehicles 2nd edition

19.1 Background 507
FIGURE 19.4
Schilling “Conan” subsea manipulator system.
In industrial manipulator systems, DoF are the possible positional variables needed in order to locate components of the manipulator system. Often in subsea manipulator systems, the term “function” is used interchangeably with DoF. The functions are easily identifiable as they contain some type of joint at each function allowing for movement of the link(s) or end effector. Each posi- tional variable is semi-independent of the other links, although the chain is interdependent. As an example of this concept, a human can place his or her hand on a doorknob, rotate with a less than outstretched arm, and then rotate the upper and lower arms while still maintaining the position of the base (shoulder) and end effector (hand).
A manipulator system has individual components allowing it to be maneuvered to interact with the environment. The manipulator system is further broken into individual components including the “base” (or fixed pedestal upon which the manipulator mates to the operating platform—in this case, the vehicle), “links” (rigid or nearly rigid strength members, between the joints, and bearing the load), “joints” (allowing for DoF or ranges of relative motion between adjacent links—often termed “function”), and finally the end of the chain of components that actually performs the “intervention,” termed the “End Effector.” The end effector can be a mechanical hand (jaw), a bolt/ screw driver, a brush, a water jet, a thruster, or any mechanical device that performs work. The base of a multifunction manipulator mates to a joint (shoulder/azimuth in Figure 19.5) and then in a link-joint-link fashion to the end of the chain where we find the end effector (or “business end”) that actually performs the work.
(Courtesy Schilling Robotics.)