Rockwell Automation 442L SafeZone Singlezone & Multizone Safety Laser Scanner - Manual (Page 27)

R
SafeZone™ Safety Laser Scanner User Manual
10000073050, July 2011 25
Original instructions
You can define different monitoring cases with different protective safety
fields. You can switch these using the static control input.
Calculation of the protective safety field length:
² Calculate the necessary protective safety field length using the formula:
SL = S
A
+ Z
G
+ Z
R
+ Z
F
+ Z
B
Where...
Stopping distance
The stopping distance comprises the braking distance for the vehicle, the
distance covered during the response time of the safety laser scanner and
the response time of the vehicle controller.
Figure 30: Stopping distance
Figure 31: Braking distance as a function of the vehicle velocity
Calculation of the stopping distance:
² Calculate the stopping distance using the formula:
S
A
= S
Br
+ S
AnF
+ S
AnS
Where...
Distance covered during the response time of the safety laser
scanner
The distance covered during the response time of the safety laser scanner
depends on
• The response time of the safety laser scanner.
• The maximum velocity of the vehicle in your mobile application.
The response time T
S
of the SafeZone multizone safety laser
scanner depends on
• The multiple sampling used.
See Section 11.2 “OSSD response times” on page 42.
Calculation of the distance covered during the response time of the safety
laser scanner:
² Calculate the distance using the formula:
S
AnS
= T
S
x V
max
Where...
A
= Stopping distance (mm)
Z
G
= General safety supplement = 100 mm
Z
R
=
Supplement for any measurement error of the SafeZone multizone safety
laser scanner related to reflection
Z
F
= Supplement for any lack of ground clearance of the vehicle
Z
B
Supplement for the reduction in the braking performance of the vehicle
as defined in the related vehicle documentation
IMPORTANT Take into account that the braking
distance for a vehicle is not linear with
increasing velocity, but increases in a
square function.
SAnF SBr
SA
SAnS
SafeZone
S
Br
= Braking distance from the vehicle documentation
S
AnF
=
Distance covered during the response time of the vehicle controller from
the vehicle documentation
S
AnS
= Distance covered during the response time of the safety laser scanner
Necessary
safety field
depth
Braking distance of the vehicle
Safety supplement
Velocit y
Stopping distance
Necessary
safety field
depth
Braking distance of the vehicle
Safety supplement
Velocit y
Stopping distance