ST Robotics DEUCALEON R17HS, User Manual

Page: 5 / 28

R17 Robot Manual
page 5
SAFETY IS YOUR RESPONSIBILITY
Risks
Because stepping motors raise more torque at low speeds a substantial low speed force
can be brought to bear especially on fingers which may become trapped under or
between axes. Robot end effectors typically have sharp edges or fingers made of thin
metal which can cause injury at the low speed high forces or at the higher speeds.
The biggest risk comes from the element of surprise. If the system is active and receives
a command from a supervising scheduler or a signal from an associated machine the
robot will appear to move unpredictably. A human being caught in the way can receive
injury, especially if the end effector has sharp edges.
However, because the robot is stepper motor driven, once stalled the system raises an
error and does not attempt further motion.
Safety measures
•
Where possible a robot system should be guarded. Any gate in the guarding can
be fitted with a switch, which is connected to the controller stop circuit.
•
If physical guards cannot be provided then light curtains are easily connected to the
robot controller or the ST Sentry sensor system.
•
Where guarding is not appropriate and bench-top robots work closely with human
workers interlocks should be provided. For example if the user has access to the
workspace then he/she should be required to press a switch or keyboard key after
clearing the area. The ST Sentry system can be used so that if a human enters the
workspace the robot will stop. It can be programmed to display a message and wait
for a keyboard input before continuing.
•
A good rule is that the robot should not be allowed to move outside an area
designated by the edge of the bench on which it is mounted.
•
As an additional precaution the working area could be marked out with painted
lines or black/yellow striped tape.
•
Statistically the highest incidence of contention between human and robot is when
both are accessing the same object. End effectors often have sharp edges which
can cause injury. Fitting a collision sensor can minimize this hazard.
•
At the end of this manual you will find a form with which to do your own risk
assessment of the robot
in your application. There are two concepts to consider:
hazard, which is the robot or robot fingers or the product etc. and risk, which is the
probability of someone being harmed by the hazard. The form enables you to
identify the hazards, the risks and ways of minimizing the risks. After completing
the form and carrying out any safety measures that the form has helped you
identify, do the assessment all over again.