task_compliance_ctrl()

Definition

task_compliance_ctrl(stx, time)

Features

This function begins task compliance control based on the preset reference coordinate system.

Caution

In non-FTS models (A0509, A0912, A0509F, A0912F, E0509), compliance control is only possible in the translation direction, and the control error may be large.
In non-FTS models, the robot may not operate normally when used near a singularity.
If the command is used in a simulation environment without a robot, it may not operate normally.
Compliance/force control may be affected by singularities, which can cause vibrations. Please be cautious and avoid using it near singularities.
Even away from singularities, vibration may occur during compliance/force control when several of the following conditions overlap: a long TCP setting, a posture with the elbow (Joint 3) strongly folded, a light tool, and low compliance stiffness. See the Note below for countermeasures.

Parameters

Parameter Name	Data Type	Default Value	Description
stx	float[6]	[3000, 3000, 3000, 200, 200, 200]	Three translational stiffnesses Three rotational stiffnesses
time	float	0	Stiffness varying time [sec] Range: 0 - 1.0 * Linear transition during the specified time

Parameter Name

Data Type

Default Value

Description

stx

float[6]

[3000, 3000, 3000, 200, 200, 200]

Three translational stiffnesses

Three rotational stiffnesses

time

float

Stiffness varying time [sec]

Range: 0 - 1.0

* Linear transition during the specified time

Caution

In the Non-FTS A & E model, the data type of the stx parameter can be either float[6] or float[3] (rotational stiffness is automatically set to the default value)

Return

Value	Description
0	Success
Negative value	Error

Exception

Exception	Description
DR_Error (DR_ERROR_TYPE)	Parameter data type error occurred
DR_Error (DR_ERROR_VALUE)	Parameter value is invalid
DR_Error (DR_ERROR_RUNTIME)	C extension module error occurred
DR_Error (DR_ERROR_STOP)	Program terminated forcefully

Note

If vibration occurs during compliance/force control, set the damping factor above 1.0 with set_damping_factor(), called right after this command.
During force control, also setting the force factor below 1.0 with set_force_factor() right after set_desired_force() suppresses vibration more stably.
Set the same value for all six axes. Find the value at which the vibration disappears at the actual work position, then apply it with some margin. A higher damping factor (or a lower force factor) slows the motion.
Both factors are reset to the default (1.0) whenever compliance control is started with this command. Set them again each time compliance control is started.

Example

Python

P0 = posj(0,0,90,0,90,0)
movej(P0, vel=30, acc=30)
task_compliance_ctrl() 		# Begins with the default stiffness
set_stiffnessx([500, 500, 500, 100, 100, 100], time=0.5) 	
# Switches to the user-defined stiffness for 0.5 sec.
release_compliance_ctrl()

task_compliance_ctrl([500, 500, 500, 100, 100, 100]) 	
# Begins with the user-defined stiffness.
release_compliance_ctrl()

Keyword

task / compliance / ctrl / release_ / task_compliance / task_compliance_