SPEED program instruction
Syntax
SPEED speed_factor, r_speed_factor units ALWAYS
Function
Set the nominal speed for subsequent robot
motions.
Usage Considerations
SPEED 100,100 ALWAYS is assumed whenever
program execution is started and when a new execution cycle begins.
Motion speed has different meanings for
joint-interpolated motions and straight-line motions.
The speed of robot motions is determined by
a
combination of the program speed setting and the monitor speed setting.
The SPEED instruction can be executed by any
program task as long as the robot selected by the task is not attached by any
other task. The instruction applies to the robot selected by the task.
If the V+ system is not configured to
control a robot, executing the SPEED instruction causes an error.
Parameters
| speed_factor
|
Real value, variable, or expression whose value is used
as a new speed factor. The value 100 is considered normal full speed, 50
is 1/2 of full speed, and so on. If IPS or MMPS is specified for
units, the value is considered the linear tool tip speed. |
| r_speed_factor |
Optional real value, variable, or expression whose value
is used as a new straight-line motion rotational speed factor. The value
100 is considered normal full speed, 50 is 1/2 of full speed, etc. |
| units |
Optional keyword—either IPS (for inches per second),
MMPS (for millimeters per second), or MONITOR—that determines how to
interpret the speed_factor parameter. |
| ALWAYS |
Optional qualifier. If specified, the program
speed_factor will be in effect until the next SPEED instruction
changes program speed. Otherwise, it is in effect only for the next
motion instruction (including APPROaches and DEPARTs). |
Details
If the units parameter is omitted, this instruction determines the program
speed—the nominal robot motion speed, assuming that the monitor speed factor is
100%.
If MONITOR is specified for units, the monitor speed is set. In this case, the parameter
r_speed_factor is ignored and
ALWAYS is assumed. The speed at which motions are actually performed is
determined by combining the values specified in this instruction with the
current program speed setting. Monitor speed changes take place immediately,
including the remaining portion of a currently executing move.
If IPS or MMPS is specified in the
units parameter,
speed_factor is interpreted as the absolute tool-tip speed for
straight-line motions. In this case, the
speed_factor parameter has no direct meaning for joint-interpolated
motions.
The effects of changing program speed and
monitor speed differ slightly for continuous-path motions. As the robot moves
through a series of points, the robot comes as close to the points as possible
while maintaining the program speed and specified accelerations. As program
speed increases, the robot makes coarser approximations to the actual point in
order to maintain the program speed and accelerations.
When the monitor speed is increased, the
path of the robot relative to the commanded destination points is not altered
but the accelerations are increased. For applications where path following is
important, the path can be defined with the monitor speed set to a low value,
and then accurately replayed at a higher monitor speed.
Speed cannot be less than 0.000001 (1.0E-6).
When the Monitor speed is set, its value is limited to a maximum of 100%.
No error is reported if a higher speed setting is specified.
When the program speed is set, its value is limited to a maximum that depends
on the robot being controlled. No error is reported if a higher speed setting is
specified. The maximum speed value for the current robot is returned by the
real-valued function SPEED(8). (That value is established with a SPEC data
item.)
During straight-line motions, if a tool
with a large offset is attached to the robot, the robot joint and flange
speeds can be very large when rotations about the tool tip are made. The
r_speed_factor parameter permits control of the maximum tool rotation
speeds during straight-line motions.
If a rotational speed factor (r_speed_factor)
is specified, it is interpreted as a percentage of maximum Cartesian rotation
speed to be used during straight-line motions. If the
r_speed_factor parameter is not specified, one of the following results
occurs:
-
If the
units parameter is also omitted, the rotational speed is set to the
value of
speed_factor.
-
If the
units parameter is specified, the rotational speed is not changed.
When IPS or MMPS are specified, the
speed_factor is converted internally to the corresponding nominal
speed. If the SPEED real-valued function is then used to read the program
speed, the value returned is a percentage speed factor and not an absolute
speed setting.
Remember, the final robot speed is a
combination of the monitor speed (SPEED monitor command), the program speed
(SPEED instruction), and the acceleration or deceleration (ACCEL program
instruction).
Examples
Set the program speed to 50% for the next
motion (assuming the monitor speed
is 100):
SPEED 50
Set the nominal tool tip speed to 20 inches
per second (assuming the monitor speed is 100) for straight-line motions.
Rotations about the tool tip is limited to 40% of maximum. The settings
remains in effect until changed by another SPEED instruction.
SPEED 20, 40 IPS ALWAYS
Set the monitor speed to 50% of normal:
SPEED 50 MONITOR
Related Keywords
ACCEL program instruction
DURATION program instruction
IPS keyword
MMPS keyword
PAYLOAD program instruction
SCALE.ACCEL system switch
SELECT program instruction
SELECT real-valued function
SPEED monitor command
SPEED real-valued function
