WAM Arm – User’s Manual
www.barrett.com
© 2008 Barrett Technology®, Inc.
Document: D1001, Version: AH.00
43 of 80
Property:
VL1, VL2
Definition:
VL1 is the minimum velocity that will cause a warning; VL2 is the minimum
velocity that will cause a fault.
Values (Units):
(rad/s or m/s)
Read/Write:
Default:
0.5, 1.0 (respectively)
Saved:
Notes:
Before calling DefineWAMpos() (otherwise known as zeroing the WAM),
VL1 and VL2 limit the
angular
velocity (rad/s) of every joint, and the 7-
segment LED display on the pendants will show which joint exceeded the
velocity limit if a velocity warning or fault occurs. After DefineWAMpos() is
called, the WAM switches to limiting the
Cartesian
velocity (m/s) of the elbow
and 4-DOF endpoint, instead of each joint’s velocity. In the event of a fault
after DefineWAMpos() is called, the 7-segment LED display on the pendants
will show “E” or “A” to indicate whether the Elbow or the Arm endpoint
exceeded the velocity limit. The value of these limits can be changed at any
time, but both limits are always applicable to the entire robot – the limits
cannot be applied only to particular joints or points on the WAM.
If you want to set these properties directly (using SetProperty()), please note
that they are in Q4.12 notation, so take whatever you want the value to be and
multiply it by 4096 before you set it. Q4.12 means "4 bits of integer, 12 bits of
fraction". 0x1000 = 1.0, 0x1800 = 1.5, 0x7800 = 7.5. If you go much higher,
you'll go negative (do not do this). See the source code for SetSafetyLimits() in
src/btwam/btwam.c for an example.
Property:
VNOM
Definition:
Values (Units):
Read/Write:
Default:
Saved:
Notes:
Property:
VOLTH1, VOLTH2
Definition:
The safety system’s high voltage warning, fault limit
Values (Units):
Volts
Read/Write:
Default:
54, 57
Saved:
Notes:
If the bus voltage exceeds VOLTH1, the safety system will begin bleeding off
bus voltage through a resistor, and the pendants will display a voltage warning
with the letter ‘H’.
If the bus voltage exceeds VOLTH2, the safety system will disconnect the bus
and clamp it, and the pendants will display a voltage fault with the letter ‘H’.
Property:
VOLTL1, VOLTL2
Definition:
The safety system’s low voltage warning, fault limit.
Values (Units):
Volts
Read/Write:
Default:
36, 30
Saved:
Notes:
If the bus voltage falls below VOLTL1, the pendants will display a voltage
warning with the letter ‘L’.
If the bus voltage falls below VOLTL2, the safety system will disconnect the
bus and clamp it, and the pendants will display a voltage fault with the letter
‘L’.
