Nachi RMU20-20, Instruction Manual

Page: 54 / 190

2.5 Operating Range, Angle and Speed Monitoring Function
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2.5.2 Operating range monitoring
“Operating range monitoring” is a function which shuts off the safety outputs and enables the robot to be
stopped safely when a robot wrist, tool, work or arm has protruded beyond one of the operating ranges.
By setting the operation restricted ranges (linear restriction/partial restriction) and sphere and arm surface
points, it shuts off the safety outputs and enables the robot to be stopped safely when the tool sphere or arm
surface point has protruded beyond one of the operation restricted ranges. The partial restriction area can be set
to an entry restriction area or a leave restriction area. In addition, by the status of selection signal which was
assigned general-purpose safety inputs 1-5, the robot will be able to enter partial restriction area.
The operation of the robot manipulator is restricted in such a way that protrusion beyond any of the operating
ranges will be prevented by the “virtual safety fence function” of the robot controller. Nevertheless, it is still
possible for the robot manipulator to move beyond the restricted range because of an operating error, trouble in
the controller or motor or other type of trouble. To prevent this, the same operating ranges which have been set
are monitored inside the RMU by the “virtual safety fence function,” and when movement is judged to have
exceeded the restricted range, the safety outputs are shut off and stop the robot.
Fig. 2-8 Model of operating range monitoring function
Safety fence range
Partial range
Tool sphere
Arm
Arm