Robots

DOE-HDBK-6004-99

Robots

Industrial robots, custom designed robots, and robotic manipulators can perform certain handling

functions. The robot systems consists of four major subsystems: the mechanical unit, drive, control

system, and tooling.

The mechanical unit consists of a fabricated structural frame with provisions for supporting

mechanical linkage and joints, guides, actuators, control valves, limiting devices, and sensors. The

physical dimensions, design, and loading capability of the robot depend upon the application

requirements.

Most new robots use electric drives. Pneumatic drives have been used for high speed, non servo

robots and are often used for powering tools such as grippers. Hydraulic drives have been used for

heavier lift systems, or where severe service is anticipated.

Electric drive systems can provide both lift and/or precision, depending on the motor and servo

system selection and design. An AC or DC-powered motor may be used depending on the system

design and applications. Hydraulic robots should be provided with operational fluids considered non

hazardous (i.e. not flammable or corrosive, negligible radiolytic effects, etc.), to avoid the creation

of mixed waste. Mixed waste is the combination of hazardous and radiological components in the

same waste form, and is extremely difficult to process.

Most industrial robots incorporate computer or microprocessor-based controllers. These perform

computational functions, and interface with and control sensors, grippers, tooling, and other

peripheral equipment. The control system also performs sequencing and memory functions associated

with communication and interfacing for on-line sensing, branching, and integration of other

equipment. Controller programming may be done on-line or from remote, off-line control stations.

Robot controllers can have self-diagnostic capability, which can reduce the downtime of robot

systems. In addition, the robot controller may be in a control hierarchy in which it receives

instructions and reports positions or gives directions. Robot manufacturers typically use proprietary

language for programming robot controllers and systems.

Tooling is manipulated by the robot to perform the functions required for the application. Depending

on the application, the robot may have one functional capability, such as making spot welds or spray

painting. These capabilities may be integrated with the robots mechanical system or may be attached

at the robot' wrist-end effector interface. Alternatively, the robot may use multiple tools that may

be changed manually or automatically during a work cycle.

110