Introduction

This quick guide discusses the Tilt functionality built in to Vector 4D devices.

All Vectors have a built in accelerometer which is able to measure and report on the installation. It effectively knows how far off 'perfectly level' it is, and can detect if - and by how much - it is 'pitched' and 'rolled' (see below).

This information is fed back into the tracking algorithm so that it can take it into account when detecting and tracking people. It is also fed back into the RIFT software in order to correctly display the field of view to mirror reality.

This can be seen here where a device has been installed at a slight angle. Note that the field of view being shown is not rectangular and is instead showing the correct symmetry and perspective for the installed angle:

 

Displaying the Tilt Angles

To see how much the device has automatically adjusted, click the Device icon:

These values are automatically detected by the built-in accelerometer in every Vector device. In the majority of cases, the detected values will be within a few degrees of horizontal (0°). If you have updated to latest firmware but do not see these options to go ‘Additional Notes’ below.

Note: while in the majority of cases a perfectly level Vector installation is desirable, it is not essential, as the accelerometer corrects for any non level device install in the tracking and counting. Therefore the Pitch and Roll angles shown here should not be seen as a measure of how well (level) a device has been installed, but instead are merely there to show you what correction is being made automatically in the background.
Note: it is important that the recording pitch and roll angles shown here are correct. If the device is adjusted and refitted at slightly different tilt angles, the 'Refresh Tilt' button should be pressed in order to update those values. Whilst failure to do this with very small differences won't affect anything too much, larger tilt angle changes will generate an error in the diagnostics logs and may affect tracking and therefore count accuracy.

 

Tilt Support Essentials

Support for tilting of devices has been added for two reasons:

  • Tilt Correction - If a device is installed against a flat ceiling, the device will automatically correct for any imperfections, as shown above in the previous example. Vector Count devices can correct up to 7.5° off horizontal, and Vector Analytics can correct up to 37°.
  • Tilt Installation Options - For Vector Analytic devices only, the 37° allowance means that they can be intentionally angled in order to see somewhere other than directly below. For example:

 

A Vector Analytic could be installed further into a store and then angled back (pitched) towards the entrance.

 

 

 

 

 

 

 

Or, a Vector Analytic could be installed at the side of an entrance and then angled sideways (rolled) so that it still sees the doorway.

 

 

 

 

In both cases, any ceiling furniture can be avoided, and the video and Time of Flight field of view will be correctly calculated and displayed on the setup Counting tab. This correction of video and Time of Flight mapping more importantly means that the accurate tracking or people within the field of view is maintained.

The accelerometer derived values are also essential in ensuring that the fields of view of devices working together as part of a Wide Tracker (multi-unit) network, all align correctly and overlap as expected. This ensures accurate tracking of people as they walk across the combined field of view provided by all devices.

 

Installation Planner/Tester Website

Irisys hosts a separate website where you can adjust the pitch, roll and also direction of some virtual devices in order to see what it does to the field of view of the Vector.

Three virtual devices can be played with a sandbox mode. This allows moderately sized wide opening networks to be tested and with different tilt options on each device.

It can therefore be used to decide if a single tilted unit can be used instead of two units pointing straight down, for example.

If you just want to see the tilt angle options on a single device, simply change the X & Y values of the others so that they are out of the way.

Go here to the installation planner website: http://installplanner.irisyscloud.net

 

Height Filtering Concerns

It is important to remember that only the centre part of the field of view is able to perform height filtering. This is because the centre part of the field of view is able to see a persons head, whereas tracking outside of the centre of the field of view is accomplished by seeing just a persons legs or feet.

But when tilting a device the height measuring zone will move slightly and you can get into a situation where the height measurement zone becomes very small and/or a strange shape at certain heights.

Care should therefore be taken when positioning lines and zones that utilize height filters on titled units.
 See more about line and zone placements here.

 

Additional Notes

All Vector devices coming from the factory will be on latest firmware and will have support for Tilting of devices enabled by default. If you find some very old devices in your estate of devices it is always strongly recommended to update them to latest firmware, and in any case to enable later features such as tilt support.

The tilt functionality was added to simplify installation whilst maintaining tracking and counting accuracy. It is now no longer essential for a Vector to be installed completely horizontal. Instead the Vector now knows its own orientation tilt angles (pitch and roll) and will simply use them as part of the tracking algorithms.

When installing a Vector and adjusting the angle of pitch or roll, always remember to click the ‘Refresh Tilt’ button so that the new values are correctly identified, and the mapping of the time of flight and video views can be updated and displayed correctly.

Once you are happy with the field of view available at your selected installation angle, click the ‘Refresh Tilt’ button but then also check that any pre-configured count lines are where they are supposed to be. Note that their position within the field of view will change slightly whenever the tilt angles are changed/updated. In some cases where a large change has been made, the lines will no longer be in the area where people walk and without adjustment count accuracy will be affected.

Remember that in all cases, lines (and other zones) should be configured and positioned only across the floor where people are able to walk.