# Fusion multiple LaserScans to PointCloud

I am currently trying to do 3D SLAM with two 2D Lidars and possibly additional IMU in ROS. However, there seems to be no ROS package available to meet my needs. The closest one would be laser_pipeline stack, but the documentation only tells me about fusioning LaserScans from "one source" although what I need is fusioning vertical scan and horizontal scan into one 3D PointCloud2. So I currently need another package to fusion scans from different sources. Anybody have an idea how to solve this problem?

• Are you sure you need a package for that instead of quickly writing the function yourself? Oct 7, 2019 at 11:26
• @FooTheBar Because I'm pretty new in ROS? Even if I try to, it would take weeks to do that for me. Oct 7, 2019 at 11:32
• What would take weeks? To get the transformation between the Lidars? Oct 7, 2019 at 12:06
• @FooTheBar It seems that my problem is a very simple thing to you. Sharing some ideas about it would be much helpful, isn't it? Oct 7, 2019 at 12:10
• Then you first have to say what exactly is the problem? Do you know the transformation between the two sensors? Oct 7, 2019 at 12:11

The laser_scan_assembler node accepts one topic as input. But you can remap or mux multiple laser scanners into that input topic and the assembler should be able to handle it. The algorithm should be using the actual headers from the incoming laser scans and consequently should be able to assemble them separately.
ALternatively you could just assemble the two scanners separately and then fuse the point clouds using the point_cloud_assembler node in the same package.