MIR 200 - Overspeed Avoidance; Stability; Emergency Stop Circuit

8. Safety system
MiR200 User Guide (en) 10/2020 - v.3.1 ©Copyright 2017-2020: Mobile Industrial Robots A/S. 80
8.3 Overspeed avoidance
The overspeed avoidance function prevents the robot from driving if the motor encoders
measure that the robot is driving faster than the predefined safety limit. This can occur if
there is a hardware error in the robot, or if it drives down a steep slope.
If the robot is driving faster than the predefined safety limit, it is immediately brought into a
Protective stop. This ensures that the robot cannot drive if its speed cannot be controlled.
8.4 Stability
The stability function prevents the robot from driving if the motor encoders measure that
the expected difference between how fast each wheel turns is outside the predefined safety
limits. This indicates that the robot is not driving as intended, for example, if one of the
wheels loses traction.
If the robot detects instability, it is immediately brought into a Protective stop. This ensures
that the robot cannot drive if it has lost control of the speed of each drive wheel.
8.5 Emergency stop circuit
TheEmergency stop circuit goes through the Auxiliary emergency stop interface and uses
external input to bring the robot into an Emergency stop. The interface uses two output pins
to provide a 24 V signal and two input pins to bring the robot into Emergency stop.
It is intended that the circuit is set up so the 24 V signal delivered from the safety
PLCoutputs passes through all Emergency stop buttons of the top module and then continues
to the two input pins. When the input pins both receive 24 V, the robot can operate. The
connected Emergency stop buttons must break the circuit when you press them so both
inputs receive a 0 V signal that will bring the robot into Emergency stop.
If the circuit or anEmergency stop button is installed incorrectly so the input signals are not
the same, the robot enters Protective stop until the circuit is fixed.