V+ 12.4 Release Notes

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SCALE.ACCEL [robot_num]

 
Function

Enable or disable the scaling of acceleration and deceleration as a function of program speed, as long as the program speed is below a preset threshold.

Parameter

robot_num Optional real value, variable, or expression (interpreted as an integer) that indicates the number of the robot affected.

Details

This switch is enabled when the V+ system is initialized.

If robot_num is omitted or zero in an ENABLE or DISABLE command or instruction, the settings for all robots are altered. Otherwise, only the setting for the specified robot is affected. If robot_num is omitted or zero when the switch is accessed with the SWITCH real-valued function, the setting of the switch for robot #1 is returned.

When this switch is enabled and the program speed is below the preset threshold value,1 the effective acceleration and deceleration for that robot are calculated as follows:

	effective acceleration = program_speed * acceleration_setting  
	effective deceleration = program_speed * deceleration_setting
 

where acceleration_setting and deceleration_setting are values set by the ACCEL instruction.

For example, if program speed 50% is specified and the threshold value is 150, the effective acceleration and deceleration are 50% of the current settings. If the program speed is higher than 150% with the threshold set to 150, the current acceleration and deceleration are used without modification.

All robot modules have the SCALE.ACCEL speed threshold set by default to a very large value, effectively forcing the scaling of accelerations and deceleration for all speeds when this switch is enabled.

CAUTION: For program speeds over 100%, if the default setting for the SCALE.ACCEL limit is used and SCALE.ACCEL is enabled, the robot is driven at much higher rates of acceleration and deceleration, as compared to V+ 11.0.

If the SCALE.ACCEL switch is disabled for a robot, accelerations and decelerations are not scaled based on the program speed. In this case, accelerations and decelerations are higher than normal at reduced speeds. This will be particularly noticeable at very slow speeds. As a result, robot motions may appear to be more rough or jerky.

Example
DISABLE SCALE.ACCEL[2]  

Turn off acceleration scaling for robot #2.

Related Keyword s

ACCEL (program instruction and real-valued function)

SPEED (monitor command and program instruction)

Syntax
SELECT-R

1

The SPEC utility can be used to set the speed threshold below which the acceleration and deceleration rates are scaled based on program speed. The SPEC parameter is:
Upper speed limit for SCALE.ACCEL (%)

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Last modified on: 07/08/2004
Copyright © 2004 by Adept Technology, Inc.
All rights reserved.