Page 509 - The ROV Manual - A User Guide for Remotely Operated Vehicles 2nd edition

506 CHAPTER 19 Manipulators
FIGURE 19.3
Anthropomorphic manipulator system.
19.1.1 Basic robotics
As stated in Part 1, the ROV is essentially a “ride to the work site” for the delivery of sensors and tooling in order to work within the environment. Once at the work site, the manipulators and tool- ing allow the vehicle to physically interact (the accepted industry term is “intervene” or “interven- tion”) in order to accomplish this work.
The use of robotics with underwater vehicles was an outgrowth of research conducted with the “industrial robot” in other industries, predominantly during the 1960s, which was then adapted to the harsh environment of the subsea world. The robotic vehicle is consistently defined by various standards organizations, but mechanical manipulator systems are a bit murky. For instance, a typi- cal subsea manipulator (Figure 19.4) would be considered a robotic manipulator, but a numerically controlled milling machine is typically not. If the system can be programmed or directed to perform a wide range of tasks, the device would be considered an industrial robot. Otherwise, it would be termed “fixed automation.”
Likewise, the manipulator is considered robotic when either “teleoperated” or directed via logic-drive. An example of what is typically not considered a robotic manipulator is a simple knuckleboom crane. This device has all of the mechanics/kinematics (“kinematics” in this case being the science of robotic motion) of a manipulator system, but the operator directly controls the function of the valves or actuators operating the arm. If that same device was operated remotely via machine logic or telepresence, it would be considered a robotic manipulator.
19.1.2 Manipulator mechanics and control
The study of the range and mechanics of robotic motion is termed “kinematics” (or the science of motion). This science simply considers the ranges of motion, position, velocity, acceleration, and other position variables without regard to the forces acting upon the manipulator system.