FAQ

Regarding installation

What dampening system can I use to isolate vibrations?

The ELLIPSE sensor is in most situations robust enough to vibrating environments that it possible to install it is directly without specific dampening.

In case of highly vibrating environments, you can still use rubber dampers such as the ones below, used for a small drone gimbal. Depending on your setup, specific dampers might be required.

What are the recommendations for a dual antenna baseline?

We recommend a 2 meters baseline for optimal performance, but for specific applications, you could reduce the baseline down to 50cm with a lower heading performance, please refer to the hardware manual for accuracy information.

What do you recommend for logging Ellipse data?

The best way to log data with the Ellipse is to use the sbgDataLogger tool on a computer. You can check the Data logging configuration operating handbook for more information on how to use this very convenient tool in order to log the Ellipse data.

You can also log the Ellipse data using a third party software or any device that logs data without changing its format.

If a computer is not available, you can use the following https://www.slerj.com/ssr-1.html (High-speed variant supports 921.6k baud model: SR122TH).

This PCB allows recording of data transmitted by the Ellipse at speeds up to 921600 bauds, and data is recorded on a microSD card.

How to use it ?

Why is my Ellipse not computing a position when I have good GNSS reception?

The most common reason for this is that the Ellipse has not yet computed a valid heading and the system is still in Vertical Gyro mode. A valid heading is required for the EKF to use the GNSS position and velocity.

The following article covers the SBG EKF modes of operation and the heading initialization requirements.

Why can't I connect to my Ellipse after changing its baud rate?

Check your sbgCenter settings, make sure that all the baud rates are selected (You can find this section under Tools - Options - Device Options - ellipsePlugin as seen below), and make sure, you uncheck the "list only SBG Systems UsbToUart devices" box.

Also, you can use a terminal and see if your Ellipse is outputting data. If there's data, you can try to reset the device to its factory default settings using the firmware updater tool, because there is a good chance that the output port is saturating due to an incompatibility between the baud rate and the output rates. 
Please note that by doing this you will reset the Ellipse configuration to the default factory settings.

Why can't I connect to my Ellipse when I am not using the SBG Systems USB cable?

If you are not using the USBtoUart cable provided with the Development Kit (ie CA-ELI-USB-3M), you have to make sure that you deselect the “List only SBG Systems UsbToUart devices” under Tools -> Device Option -> ellipsePlugin, then Apply.

Why is the SBG Systems GGA string longer than the current standard?

This is due to NMEA 0183 limitations. It was designed at a time when systems were not as accurate as today (for navigation mostly).

Many customers now need more accuracy which is why we added the digits on position (for survey for example but navigation too).

If we had to respect the limitations there would not be enough digits for the accuracy we can provide.

How to configure switches on the Ellipse Micro development board ?

Depending on your system, you have to configure switches properly. You can find detailed information on this Tutorial: Use Ellipse Micro dev board.

Optimum conditions for fast GNSS fix & heading to reach Navigation mode?

It is strongly advised to power up outside with a clear sky view for the antenna. In the case where you start moving from a garage and/or reversing out of a parking lot, please reset the unit (or power cycle it) when in clear sky view to start the initialization procedure.

It should take less than 25 seconds to have a GPS position fix, then according to your hardware:
- Ellipse-D: it will take another 25 seconds to compute a solution for true heading between the 2 antenna’s positions.
- Ellipse-N: you need to move forward at 3m/s minimum to compute a kinematic heading solution.

Once you have a heading, you will be in Full Navigation mode, and you would start the warm-up of the INS by performing 'Figure 8' maneuvers of several 10's of meters amplitude (self-rotation of the vessel do not lead to proper alignment) in order to reach a fine bias estimation of the sensors and EKF solution (including all other aiding’s, like DVL or odometer, you may use).
See https://support.sbg-systems.com/sc/el/latest/operating-handbooks/operations
If you have a GPS position fix, but no heading you will never be in Full Navigation mode (see above 1st subject)

What can delay (or kill) a dual antenna setup :
- Not using the exact same antenna type will more than likely fail any attempts.
- No clear sky view (close too trees or building, multipath, canyons) for both antennas
- Bad settings in antenna lever arms (baseline is 1 meter minimum, 2 meters is better)
- Antenna not facing up in the same horizontal plane (not same 360° view of sky)

From the Ellipse settings, If you have selected Rough Lever Arm, or not ticked the Precise lever Arm box,

EKF will compute an estimation of the lever arm from the rough value and that would delay computation of a heading solution by another 30 seconds.
Best practice : Measure precisely the lever arms (as much as possible) and tick The primary antenna....precisely box.
Leaving 0.00 ; 0.00 ; 0.00 for any or both antennas accounts for bad lever arms.

Leave all aiding rejection to Automatic, EKF will manage.

The above applies to all aidings.

Disable magnetometer if you do not use it or if you are on Ellipse D using dual antennas, under firmware version < 3.x.
(Using a non-calibrated magnetometer is a failure to come).

RTK and PPP corrections

How to determine if my Ellipse-D is RTK enabled?

In the sbgCenter, open the device information window and the RTK option should be listed under the GNSS tab additional features section.  

How do I configure my Ellipse to receive RTK corrections?

First of all, make sure you enable the port you want to use for RTK corrections in Configuration, Aiding Assignment, RTCM.

You will need to configure this selected port for RS232 communication with a baud rate that matches the baud rate of equipment sending the RTK corrections to the Ellipse.

What RTK corrections format is compatible with the Ellipse?

The Ellipse v3 is compatible with the RTCM 3.x format.

How to determine if the Ellipse is receiving RTK corrections?

You can check the position type status in the SBG_ECOM_LOG_GPS1_POS (14) output message which should indicate it is in RTK mode.

In the sbgCenter, open the GPS window, and in the solution type it should say RTK. If not, then it is not receiving the corrections properly and this could be due to a wiring, or formatting, or configuration issue.

Can I use PPP corrections with the INS?

The embedded GNSS receiver in the Ellipse is not compatible with PPP corrections.

It is possible to use an external GNSS receiver compatible with PPP corrections instead of the embedded one if needed.

It is also possible to use PPP in post-processing with Qinertia.

ROS 

Is it possible to utilize the ROS driver to send RTCM corrections?

Yes, our ROS driver is compatible with the existing NTRIP clients for ROS.

Is it possible to configure the Ellipse port A baud rate through ROS?

No, ROS driver does not handle the change of the baud rate of the configuration port. To make this change, you will need to use sbgCenter.

Is Qinertia compatible with ROSBAG format?

No, currently Qinertia does not support the ROSBAG format.

Which products are compatible with ROS?

All our IMU, AHRS and INS are compatible with ROS.

Pixhawk

Is it possible to use the Ellipse IMU instead of the Px4 one?

No, Px4 architecture is not suitable to use third party IMU data.

Can I use the Ellipse INS/AHRS solution instead of the Px4 estimation filter?

No, Px4 architecture is not designed to replace the estimation filter, as it is deeply integrated with stabilization algorithms.

Can I use the Ellipse to feed Px4 with RTK positions?

Yes, Ellipse Px4 driver has been designed to forward the GNSS solution to the Px4 estimation filter. Only GNSS PVT data will be forwarded when RTK GNSS aiding is available, and not the Ellipse INS solution.

Need more help ?

Where to find the documentation for my Ellipse?

All manuals can be found in this "Ellipse" product page.

Additionally you can download and install the Windows SDK from this webpage.

Once installed, you'll be able to access the latest documentation for your Ellipse on this path on your computer: C:\Program Files\SBG Systems\Inertial SDK\Documentation.

How to log data for Support analysis?

You have to record data directly from port A using the data output indicated below.

You need to configure this properly under the configuration page - data output - port A.

Make sure the baudrate is high enough to avoid saturation, 460800 bauds is recommended.

Once you've done this, click the record button, preferably 10 to 15 minutes while simulating your data acquisition.

Finally, save the recording.

How to contact Support?

SBG Systems Support Team is here to help, but they need to get all elements of the situation to be 100% efficient.

Did you check the documentation?

Sometimes your question is already answered by the documentation that is part of the SDK. You just need to know where to find it: Have a look in the installation directory of your SDK by default in:

C:\Program Files\SBG Systems\Inertial SDK\Documentation

Define the context:

• Vehicle (ship, car, plane, drone, etc…).
• Unit (Ellipse, Ekinox, Apogee, Navsight, etc...) product code, serial number.
• Installation (photos of the setup, where are placed the unit and antennas in the vehicle).
• Configuration (export of the settings, firmware version).
• Logs (Binary recording in sbgECom format as seen above).
• Details on the issue (What is the expected and observed behavior).

This will help us give you an immediate and to the point answer.

You can then either drop us an email support@sbg-systems.com or call us at the following numbers:

Singapore: +65 31650079  /  France: + 33 1 80 88 43 70  /  US: +1 (657) 549-5807

Remote Quick Start

A 2-hour session to get started with your sensor.

The Remote Quick Start is an economic and quick way to get started with your SBG Systems inertial sensor. It consists in a 2-hour session with an SBG Systems support engineer, using a remote access software (e.g. Teamviewer).

Intervention days

An SBG Systems support engineer at your side for assistance, installation, and commissioning.

Benefit from SBG Systems’ experience to get help for system installation and commissioning, integration, or on-site support. This service can only be done on site, travel time is included.