ekf_localizer is not activated

[ahsan155]

I am trying to do localization. I only have a lidar attached to the vehicle. I place the vehicle on the map using '2d Pose Estimate' button and start collecting lidar data.

I run ndt_scan_matcher and ekf_localizer. but why does ekf_localizer says that it is not activated? after running ekf_localizer, I placed the vehicle on other locations which publishes initial pose but ekf_localizer keeps saying its not activated.

How many nodes should I run to do localization? I also tried running pose_initializer and getting error there too

[SakodaShintaro]

Sorry for the lack of documentation.

The EKF has a service to activate a node, and calling it with true activates the node.

• https://github.com/autowarefoundation/autoware.universe/blob/8416d2c26a3099cffea3105239449b023e8db06f/localization/ekf_localizer/include/ekf_localizer/ekf_localizer.hpp#L140
• https://github.com/autowarefoundation/autoware.universe/blob/8416d2c26a3099cffea3105239449b023e8db06f/localization/ekf_localizer/src/ekf_localizer.cpp#L468-L481

This service is usually called from a pose_initializer.

https://github.com/autowarefoundation/autoware.universe/blob/8416d2c26a3099cffea3105239449b023e8db06f/localization/pose_initializer/README.md#connection-with-default-ad-api

pose_initializer requires the arguments.

https://github.com/autowarefoundation/autoware.universe/blob/8416d2c26a3099cffea3105239449b023e8db06f/localization/pose_initializer/config/pose_initializer.param.yaml#L4-L5

The following part may be helpful.

• https://github.com/autowarefoundation/autoware.universe/blob/8416d2c26a3099cffea3105239449b023e8db06f/launch/tier4_localization_launch/launch/pose_twist_estimator/pose_twist_estimator.launch.xml#L106-L122
• https://github.com/autowarefoundation/autoware.universe/blob/8416d2c26a3099cffea3105239449b023e8db06f/launch/tier4_localization_launch/launch/pose_twist_estimator/pose_twist_estimator.launch.xml#L25-L28

[ahsan155]

thanks for the response. I just set is_activated_ = true in ekf_localizer.cpp file. Is this enough to run the node? will it cause issue with other nodes?

[SakodaShintaro]

I think it is important to initialize the internal state of the EKF itself using the following callback.

• https://github.com/autowarefoundation/autoware.universe/blob/8416d2c26a3099cffea3105239449b023e8db06f/localization/ekf_localizer/src/ekf_localizer.cpp#L299-L310

Normally, this topic is named /initialpose3d when launched the entire autoware,
https://github.com/autowarefoundation/autoware.universe/blob/dfd3c13c0abd4a54abddc0c1a85c811d5aa22ff6/launch/tier4_localization_launch/launch/pose_twist_fusion_filter/pose_twist_fusion_filter.launch.xml#L5

but if you are launching it as a node on its own, the topic name may be difference.

The following procedure is followed when initializing.

1. Set the ekf and ndt states to false.
   • change_node_trigger(false, false);
2. Call ndt's initial pose estimation service
   • pose = ndt_->align_pose(pose);
3. Set the retrieved pose to the EKF.
   • pub_reset_->publish(pose);
4. Set the ekf and ndt states to true
   • change_node_trigger(true, false);

https://github.com/autowarefoundation/autoware.universe/blob/8416d2c26a3099cffea3105239449b023e8db06f/localization/pose_initializer/src/pose_initializer/pose_initializer_core.cpp#L155-L169

We don't know which topics are being used in your environment or when, but the above steps are what Autoware is designed to do.

I hope this information is of help to you.