manipulator

This article covers technical devices called manipulators. On the subject of "(hidden) influencing of opinions and actions" see u. a. Manipulation .

The following important information is missing from this article or section:

Manipulators are not only found in industrial robots, but also in virtually all technical devices in which a workpiece or sample has to be placed or modified.

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In robotics, a manipulator is the device that enables physical interaction with the environment, i.e. the moving part of the robot structure that performs the mechanical work of the robot. In principle, the manipulator is the part that is usually associated with an industrial robot .

tasks

Manipulator of a robot

An industrial robot generally has the following goals:

• Manipulation tasks, so z. B. welding , cutting , engraving , etc. - like all conventional manufacturing processes
• Positioning tasks: moving objects in space without editing them, e.g. B. workpiece feed for a machining center
• Measurement tasks

For these tasks, the robot must be appropriately equipped with tools, gripping systems or measuring devices . What all three have in common is the need to place the tool center point of the respective tool in different poses ( positions and orientations ) in space.

For this purpose, each robot has several axes of rotation or thrust (rotary or translational axes), which are superimposed by combining the individual movements to form an overall movement.

construction

Elements of a manipulator are:

• the base (the foundation),
• the axes with the drive units (motors, gears, angle encoders),
• the connecting elements for the structural design and the mechanical coupling of the axles,
• Cables or lines for their energy supply, control and signal transmission,
• the case

control

In addition to manipulators, which are programmed to automatically carry out processes over and over again (e.g. in production lines of car manufacturers), manipulators are also controlled manually. Maintenance work in areas of a nuclear power plant that are exposed to radiation is often carried out manually using manipulators. In ROVs manipulators are used to be able to perform activities with water (eg. As welding, collect scientific samples, open and close valves).

Waldo

In English usage the term Waldo is sometimes used, it comes from the science fiction short story of the same name by Robert A. Heinlein from 1942. There it describes manipulators, which were named after their inventor Waldo Farthingwaite-Jones, who suffered from muscle weakness .

Welding turn-tilt table

Manipulator, welding manipulator with universal table top and workpiece attached to it

A conventional welding turn-tilt table (standard welding turn-tilt table) is a device that enables a component to be manipulated around two axes (tilting and turning). Another design is a table with a turn-tilt unit and an additional lifting axis. As a rule, however, these devices are significantly larger and more investment-intensive than rotary-tilting tables of the same size. Welding tilt and turn tables usually have a universal mount that is used to fasten the workpieces. With this holder, the components are clamped directly or using a specialized device (e.g. using a jaw chuck).

Rotation and tilt axis

The tilting axis of a rotary tilting table is used to position a component so that it is suitable for welding - the "welding position" is decisive here. The axis of rotation is used for the rotational movement of the workpiece and its speed can usually be regulated. The speed control is necessary because pipes or other round parts often have to be welded. In these cases the constant rotary movement can be used as a feed. The welding torch can be held stationary in one position, the tube rotating and a continuous weld seam being created.

Ergonomics and welding quality

If round components are not welded, the welding turntable still has advantages. On the one hand, the position in which a weld is carried out has an influence on the quality of the weld seam and is in part also prescribed by the standard (see welding position, DIN EN ISO 6947). If different positions on a component are welded in different positions, the tilting rotary table can align the component in such a way that this can be done quickly and thus cost-effectively. On the other hand, these manipulators are often used in manual production. In such cases a welder stands at the tilting table and guides the welding torch by hand. The welder tires the faster the more unfavorable the position or posture in which he has to perform the welding task. Here, too, a welding tilt and turn table can provide a remedy by enabling an optimal welding position and good ergonomics.

Controls

There are a variety of control options for rotary tilting tables. These range from unregulated axes that are operated via a simple user interface or a pedal, through controllable axes, to fully controllable drives that have position or angle measuring systems so that a position that has been approached and saved can be automatically approached again and again. Depending on the controls, different levels of automation can be achieved during welding and it is sometimes possible to run a welding process automatically. An operator only has to intervene in the production process when changing tools or in the event of malfunctions.

See also

• Handling device

literature

• Lorenzo Sciavicco, Bruno Siciliano: Modeling and Control of Robot Manipulators . 2nd Edition. Springer, London 2001, ISBN 978-1-85233-221-1 .