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For newer ROS distro than Indigo

Supported Hardware

This driver should work with any SCIP 2.0-compliant laser range-finders.

API Stability

The ROS API of this driver should be considered stable.

Parameter Ranges

The UTM-30LX laser can report corrupt data and even crash if settings with an excessive data rate are requested. The following settings are known to work:

Intensity mode off:

• cluster: 1

• skip: 1

• intensity: false

• min_ang: -2.2689

• max_ang: 2.2689

Intensity mode on:

• cluster: 1

• skip: 1

• intensity: true

• min_ang: -1.047

• max_ang: 1.047

Allow Unsafe Settings Option

On the UTM-30LX, unless the ~allow_unsafe_settings option is selected, the hokuyo_node will limit the angular range to values that are known to work. The angular range limit depends on the firmware version, and is proportional to the cluster parameter.

ROS API

Parameter interactions

Some parameter settings can cause problems, usually due to speed limitations of the laser's serial interface. For example:

• if intensity is true and skip is 0, then the device will likely drop some scans;

• if intensity is true and min_ang / max_ang are outside -70 / +70 degrees, then some problems have been observed.

Command-Line Tools

The getID and getFirmwareVersion programs can be used to get information about a hokuyo laser scanner. Each of them can be invoked in a human readable way:

$ rosrun hokuyo_node getID /dev/ttyACM0
Device at /dev/ttyACM0 has ID H0807228

or in a script friendly way:

$ rosrun hokuyo_node getID /dev/ttyACM0 --
H0807228

If they fail to connect to the device they will retry for about ten seconds before giving up.

Using udev to Give Hokuyos Consistent Device Names

The getID program can be used to get the hardware ID of a Hokuyo device given its port. Combined with udev, this allows a consistent device name to be given to each device, even if the order in which they are plugged in varies. The following udev rule should work universally on any ROS system:

KERNEL=="ttyACM[0-9]*", ACTION=="add", ATTRS{idVendor}=="15d1", MODE="0666", GROUP="dialout", PROGRAM="/opt/ros/hydro/env.sh rosrun hokuyo_node getID %N q", SYMLINK+="sensors/hokuyo_%c"

This udev rule sets up a device name that is based on the Hokuyo's hardware ID. The PR2 then has a symlink to that name that gets changed if the Hokuyo is replaced:

$ ls -l /etc/ros/sensors/base_hokuyo
lrwxrwxrwx 1 root root 28 2010-01-12 15:53 /etc/ros/sensors/base_hokuyo -> /dev/sensors/hokuyo_H0902620
$ ls -l /dev/sensors/hokuyo_H0902620
lrwxrwxrwx 1 root root 10 2010-04-12 12:34 /dev/sensors/hokuyo_H0902620 -> ../ttyACM1

Communication Protocol Documentation

• The SCIP 2.0 protocol is described in URG-Series_SCIP2_Compatible_Communication_Specification_ENG.pdf.

• The extension for intensity scans is documented in UTM-30LX_Specification.pdf.