How can I use two velodyne(VLP16) together at the same time?
Hello, I have a question about operating two velodyne laser sensors (VLP 16).
I’m a ROS and Ubuntu beginner. So, even if my question is inexperienced, please understand me and answer as in detail as possible. Thank you in advance.
I use Ubuntu 14.04 and ROS indigo. I’m trying to operate two velodyne laser sensors – VLP 16 simultaneously in one laptop. I designate IP of each sensors as 192.168.1.201 and 192.168.1.202. I fixed my laptop Ethernet IP as 192.168.1.77 to coincide bandwidth(?); I mean the third number of IP address like 192.168.”1”.77. I made two sensors connect to my laptop using hub. I use Velodyne package and modified “VLP16_points.launch” in velodyne_pointcloud folder and “nodelet manager.launch” in velodyne_drvier folder to operate at the same time.
In nodelet_manager.launch of velodyne_driver folder, I attached <arg name=”device_ip” default=”” />
under the source code <arg name=”model” default=”VLP16” />
and <param name=”device_ip” value=”$(arg device_ip)” />
under the source code <arg name=”frame_id” default=”veldyne” />
In VLP16_points.launch of velodyne_pointcloud folder, I made the source code as two group and tried to operate independently. First group is defined <group ns = “ns1”></group>
and second group is defined <group ns = “ns2”></group>
. The difference of two group’s source code is the only “device_ip”. I defined <arg name = “device_ip” value = “192.168.1.201”/>
in first group and <arg name = “device_ip” value = “192.168.1.202”/>
in second group. I thought because I designated the IPs differently it had to be implemented independently. But it was not.
I ran VLP16_points.launch and rviz , and topic of Pointcloud2 in rviz was presented /ns1/velodyne_points, /ns2/velodyne_points. As I pick the topic: /ns1/velodyne_points, pointcloud of two VLP16s appear simultaneously with regardless of IP address. I tried changing sensors’ IP and “device_ip” of VLP16_points.launch and nodelet_manager.launch. But regardeless of these change, pointcloud in rviz was appeared at the same time in topic /ns1/velodyne_points which is the topic of first group in VLP16_points.launch. When I pick the topic as /ns2/velodyne_points, no pointcloud appears. The terminal presents “bind: Address already in use” The Notice was not showed when I run only one VLP16. I hope to use the pointcloud independently to apply tf to sensors independently.
There were also other attempts in similar ways like operating two same launches which has “different device_ip”. But it also shows same result.
Thank you for reading this long question.
Have a nice day.
Hi, I'm trying to use two VLP16 at one computer. I have same problems with you. Did you solve this kind of a problem? If you do that, How did you solve it? Thank you in advance
The Velodynes broadcast, so they are all spamming the same port unless you change it on each device.