Basic Operating Guidelines and Hints
Last updated
Last updated
The Tracker 650 is optimized for use on an ROV. When using in other scenarios also consider the guidelines below in light of your own scenarios.
The Tracker 650 should be operated so it is as close to level as possible when moving. Most ROVs have a flight controller that holds it level during flight. If you fly your ROV in a tilted orientation, then you should adjust the DVL orientation to be level at the normal flight attitude of the ROV.
The ROV should be ballasted so it floats exactly level when it is disarmed.
The Tracker 650 reports a "roll" and "pitch" estimate in the $DVPDX message. Not to be confused with actual roll and pitch, these are based strictly on the range estimated of each beam, and thus will be noisy. The intent of the roll and pitch estimates are for use when the DVL is mounted in a non-standard way (e.g., pointing forward) to help you line up your vehicle with non-seabed items like ship hulls or seawalls. So 0,0 roll and pitch means the DVL sensor is reasonably parallel to some surface which may be at an arbitrary orientation.
We supply a user interface for the Tracker 650 called CeruleanTracker, now deprecated in favor of our SonarView application or the . It does not need to be running for the Tracker 650 to work. You can use it to set options or to send initial positions to the ROV (see below). Sending positions is a deprecated function and we recommend our SonarView software for this.
The Tracker 650 is to do position hold and dead-reckoning navigation in conjunction with QGroundControl (QGC), ArduSub, and BlueOS using an interface called MAVLink ( is the interface to ArduSub). There are no plug-ins required to make the Tracker 650 work with newer versions of BlueOS. You should be aware of a few quirks:
ArduSub is the part of the system that combines the Tracker 650 odometry with the ArduSub's inertial measurement unit (IMU) to provide position tracking. In order to get good position tracking you must make sure the ROV basic sensors are properly calibrated. The Tracker 650 does not require any calibration.
You don't need a BlueOS extension to use the DVL. You do, however, need to .
When ArduSub is powered up it "thinks" it is located at latitude 0, longitude 0, a point somewhere off the west coast of Africa. If you are using QGC, the map overlay is blank here.
Before ArduSub will do position hold, it must be given a Global Origin. The Global Origin tells ArduSub where it is located in the world.
The Tracker 650 can optionally send a Global Origin message of (0,0) to ArduSub while everyone is waking up. This location is that same spot off the coast of Africa. If you set the Tracker 650 to automatically send the Global Origin, then position hold will always work and you can do relative tracking of the ROV position in QGC. This does make it more difficult for novices to get the real-world ROV position to show correctly in QGC. The Tracker 650 is shipped with this feature turned off. Rule of thumb: if you only care about position hold, turn this option ON. If you want to see the true lat/lon position of the ROV on the QGC map, turn this option OFF and figure out how to get the the starting position of the ROV to ArduSub (CErulean's SonarView software may be able to help you with this). Note also if you have an Omnitrack setup, you should leave the auto origin checkbox OFF.
ArduSub can only be told its Global Origin one time per power cycle. The Tracker 650 option to send a global origin defaults to off, because if you have a different way to set the true latitude/longitude position of the ROV, it won't work if the Tracker 650 gets there first with its (0,0) message.
The Tracker 650 does accept a command called that can pass the Tracker 650 an initial position in DD, DDM, OR DMS format, and the Tracker 650 will pass this along to the ROV using a Global Origin message if the checkbox is OFF. So, if you are able to send commands to the DVL, you can leave the default Global Origin message turned off and send the true GPS position when you are ready. The same command can be used to update the position, although if the updated position is too far from the position the ROV has calculated, the Kalyan filter can go whacky.
, the Tracker 650 user interface, can also help send the true position to the Tracker 650 to pass along to ArduSub. There is a facility on the DVL Command Window to do this. This capability of CeruleanTracker is deprecated in favor of Cerulean's SonarView software.