Basic Characteristics RAPID

Motion and I/O Principles Coordinate Systems
1 Coordinate Systems
1.1 The robot’s tool centre point (TCP)
The position of the robot and its movements are always related to the tool centre point.
This point is normally defined as being somewhere on the tool, e.g. in the muzzle of a
glue gun, at the centre of a gripper or at the end of a grading tool.
Several TCPs (tools) may be defined, but only one may be active at any one time.
When a position is recorded, it is the position of the TCP that is recorded. This is also
the point that moves along a given path, at a given velocity.
If the robot is holding a work object and working on a stationary tool, a stationary TCP
is used. If that tool is active, the programmed path and speed are related to the work
object. See Stationary TCPs on page 10.
1.2 Coordinate systems used to determine the position of the TCP
The tool (TCP’s) position can be specified in different coordinate systems to facilitate
programming and readjustment of programs.
The coordinate system defined depends on what the robot has to do. When no
coordinate system is defined, the robot’s positions are defined in the base coordinate
system.
1.2.1 Base coordinate system
In a simple application, programming can be done in the base coordinate system; here
the z-axis is coincident with axis 1 of the robot (see Figure 1).
Figure 1 The base coordinate system.
Z
Y
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X