low_pass_target

LowPassTarget

Filter the joint targets (references) with a configurable Butterworth low-pass filter.

⚠️ This plugin must be inserted in the model before enabling the controller (either the default PID or a custom one). In the case of PIDs, they are enabled by ScenarIO when either Joint::setControlMode or Model::setJointControlMode are called.

Metadata

lib_name	class_name
LowPassTarget	gsp::LowPassTarget

Context

Name	Optional	Type	Default	Description
cutoff_frequency	No	float	-	The cutoff frequency of the Butterworth filter. It cannot be bigger than half of sample_rate.
order	Yes	integer	2	The order of the Butterworth filter
sample_rate	Yes	float	0	The sample rate of the filter. If 0, it defaults to the physics rate of the server.
target_type	Yes	string AUTO, FORCE, POSITION, VELOCITY	AUTO	The type of target to filter. If AUTO, the type is inferred from the joint control mode.

SDF

<plugin filename="LowPassTarget" name="gsp::LowPassTarget">
    <!-- Context -->
    <cutoff_frequency>5.0</cutoff_frequency>
    <!-- Optional context -->
    <order>2</order>
    <sample_rate>100.0</sample_rate>
    <target_type>AUTO</target_type>
</plugin>

Python

from gazebo_scenario_plugins import plugins
from scenario import gazebo as scenario_gazebo

# [...] Create the simulation and insert the model 'my_model'

# Create the plugin context
low_pass_target = plugins.LowPassTarget(
    cutoff_frequency=5.0, 
    order=2,
    sample_rate=100.0,
    target_type=plugins.LowPassTargetType.AUTO,
)

# Get the joint 'my_joint_name' from the model
my_joint = my_model.get_link("my_joint_name")

# Insert the plugin to the joint
ok = scenario_gazebo.insert_plugin_to_gazebo_entity(
    my_joint.to_gazebo(), *low_pass_target.args())
assert ok, "Failed to insert the plugin"