API review

Proposer: Chad Rockey

Present at review:

• Tully Foote
• Michael Carroll
• Eric Perko
• Gonçalo Cabrita
• Dave Hershberger
• Jack O'Quin

Background

With the addition of REP 117, sensor_msgs/Range can now be extended to support fixed distance rangers.

Detections that are too close to the sensor to quantify shall be represented by -Inf.

Finally, out of range detections will be represented by +Inf.

A fixed distance ranger is simply a ranger with min_range===max_range that can only output -Inf or +Inf.

An example of this sensor is the Sharp GP2D15: http://www.acroname.com/robotics/parts/R49-IR15.html

New Definition

Only the comments are changing, so this will not trigger a migration.

• sensor_msgs/Range

# Single range reading from an active ranger that emits energy and reports
# one range reading that is valid along an arc at the distance measured. 
# This message is  not appropriate for laser scanners. See the LaserScan
# message if you are working with a laser scanner.

# This message also can represent a fixed-distance (binary) ranger.  This
# sensor will have min_range===max_range===distance of detection.
# These sensors follow REP 117 and will output -Inf if the object is detected
# and +Inf if the object is outside of the detection range.

Header header           # timestamp in the header is the time the ranger
                        # returned the distance reading

# Radiation type enums
# If you want a value added to this list, send an email to the ros-users list
uint8 ULTRASOUND=0
uint8 INFRARED=1

uint8 radiation_type    # the type of radiation used by the sensor
                        # (sound, IR, etc) [enum]

float32 field_of_view   # the size of the arc that the distance reading is
                        # valid for [rad]
                        # the object causing the range reading may have
                        # been anywhere within -field_of_view/2 and
                        # field_of_view/2 at the measured range. 
                        # 0 angle corresponds to the x-axis of the sensor.

float32 min_range       # minimum range value [m]
float32 max_range       # maximum range value [m]
                        # Fixed distance rangers require min_range==max_range

float32 range           # range data [m]
                        # (Note: values < range_min or > range_max
                        # should be discarded)
                        # Fixed distance rangers only output -Inf or +Inf.
                        # -Inf represents a detection within fixed distance.
                        # (Detection too close to the sensor to quantify)
                        # +Inf represents no detection within the fixed distance.
                        # (Object out of range)

Question / concerns / comments

Enter your thoughts on the API and any questions / concerns you have here. Please sign your name. Anything you want to address in the API review should be marked down here before the start of the meeting.

• ((Tully)) This seems to be a reasonable update following REP 117.
• ((Michael)) No concerns or questions. Looks good.

  • (Eric) +1

  • (Dave) +1

  • (Jack) +1

Meeting agenda

To be filled out by proposer based on comments gathered during API review period

Conclusion

Package status change mark change manifest)

• Action items that need to be taken.

• Major issues that need to be resolved