getLinkModelNamesWithCollisionGeometry() does not include base_link of robot

[MarqRazz]

Description

I am working on a robot that includes a linear actuator at the base of a UR5. When testing a pick and place MTC task I noticed that I was getting plans that included collision between the base_link of the linear actuator group and my attached collision object.

In my robots srdf file I have the following groups included to allow motion planning with the arm + actuator at the same time:

    <group name="linear_actuator">
        <chain base_link="linear_actuator_base_link" tip_link="linear_actuator_carriage_link"/>
    </group>
    <group name="manipulator">
        <chain base_link="base_link" tip_link="tool0"/>
    </group>
    <group name="linear_actuator_and_manipulator">
        <group name="linear_actuator" />
        <group name="manipulator" />        
    </group>

In my MTC task I am getting the collision links of the motion planning group to allow and exclude collision between different groups with the following function:

const auto& manipulator_group_collision_link_model_names = task
                                                    ->getRobotModel()
                                                    ->getJointModelGroup("linear_actuator_and_manipulator")
                                                    ->getLinkModelNamesWithCollisionGeometry();

But when I inspect this list the linear_actuator_base_link is not part of it.

Links with Collision Geometry: [linear_actuator_carriage_link, base_link_inertia, shoulder_link, upper_arm_link, forearm_link, wrist_1_link, wrist_2_link, wrist_3_link]

Debugging the construction of the group I noticed that all base_links of a group are not included in the JointModelGroup. This kinda makes sense because the base is not a joint but the pair of links that make the first joint should include it's collision geometry.

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[github-actions]

This issue was closed because it has been stalled for 45 days with no activity.