Pan and Tilt

Troubleshooting Guide for Mechanical Pan and Tilt

1. Introduction

This troubleshooting Guide is targeting Axis customers to be used as a self-help. The guide should help our customers to find possible mitigations to common issues they might encounter.  The guide as well covers the data that is needed to be collected and provided when opening a support case. This should help the Axis Support Team to quickly assist them with the issue they are facing by providing them the correct and needed information.   

NOTE

Axis cameras will operate as intended if installed as specified by the Installation Guide. Generally, the dome of the device should be facing the ground when operating or testing the devices.

Please note that Axis does not take any responsibility for how the modification of the configuration described in this guide may affect your system. If the modification fails or if you get other unexpected results, you may have to restore the settings to default.

2. Devices behaviours

Shocks and vibrations are the main factors that can influence and affect the normal operation of the mechanical Pan and Tilt mechanism. The shocks and vibrations are seen mainly in installations with strong wind, heavy traffic vehicles, less stable mounts (inadequate mount poles).

These factors might affect the Axis cameras operations in the following ways:

2.1 Shaky image

The image is entirely shaking, this distorts the image heavily. The effect is more severe at higher zoom levels.

Possible Mitigation

 

2.2 Rolling Shutter (Wavy image):

A wavy image can be seen in some models using CMOS-sensors. The effect is caused by the rolling shutter. More detailed articles about the rolling shutter can be found on this external page. The effect is more severe in high zoom levels.

Possible Mitigation

  • Use a higher shutter speed (e.g. 1/50)
  • Lower the pan speed when moving to avoid waviness effect
  • Reduce the zoom level - the effect is amplified in high zoom levels

2.3 Positions drifts

Pic 2.3-1 Original Position

Pic 2.3-2 Drifted Position

2.3.1 Position accuracy

The ability to move to a preset (pre-saved position) or desired position within the products position accuracy range. The accuracy range can be found in the respective product datasheets. Keep in mind that in high zoom levels the accuracy range can be quite noticeable in a scene.

2.3.2 Physical device moves

Vibrations can cause the devices to move physically or the mechanics to shift slightly. This can affect the pre-saved positions such as presets and focus recall zones and 3D privacy masks. If the devices move physically this is often caused by an unstable mounting or installation. If the shift is caused by an unstable mount that leads to a physical move of the camera, the installation then needs to be stabilized and the positions recreated. 

Pic 2.3.3-1 Initializing PTZ Calibration

2.3.3 PTZ calibration

The shift might be caused as well by drifting mechanics. Different models have several ways to handle the drifting offset. In most cases this is handled automatically by the device itself during normal operation. When the calibration is finished the device will recover its initial position. If a correction of the drifting is happening a warning message can appear.

The autocalibration will happen during the bootup process but can also be launched manually in the camera WEB GUI > System Maintenance Section.

Pic 2.3.3-2 Automatic PT calibration

Pic 2.3.3-3 PTZ test: Pan and Tilt calibration in the WEB GUI. Manual Pan and Tilt Calibration

Pic 2.3.4 PTZ Error

2.3.4 PTZ Error

If the device detected the offset but still cannot correct it.  An error message will be displayed indicating that the device has detected an error and it needs to be recalibrated.

The following are causes that may result in failing Pan and tilt calibration (correction). 

  • The calibration is performed when the camera is subject to vibrations shocks
  • The Pan and Tilt mechanism is broken.

2.4 Privacy Masks Drifts

The 3D privacy masks rely on the cameras position accuracy. If the preset is drifted, there are high probabilities that the 3D privacy mask will be drifted as well. A pan and tilt calibration will help to correct the drifted masks.

Possible Mitigation

  • Stabilize the installation
  • Manual Pan and Tilt calibration
  • Scheduled regular Pan and Tilt calibration

Pic 2.4-1 Initial preset and mask position

Pic 2.4-2 Drifted pre-set and privacy mask 

2.5 Privacy Masks drift under PT movements

Depending on the shape of the mask, the mask grows during PTZ movements. This is due to the different perspective. The privacy mask can’t skew itself and will always stay straight. To maintain that, the privacy mask naturally needs to grow when shown from a different angle.

Pic 2.5-1 Original Mask

Pic 2.5-2 Grown Mask

Possible mitigation

  • Splitting the privacy mask in several masks:

Pic 2.5-2 Several Privacy Masks

3.Opening a support case

The technical support team needs pictures and recordings for a positioning drifting troubleshooting.  In some situations, the behavior or the issue cannot be seen in the System logs.

NOTE: It is always important to test the devices on the latest firmware on an LTS track or Active Track if possible

3.1 Data and Information Needed

NOTE: Please do not forget to add the Server Report of the device!

Support tip: How to download a Server Report

The best way to troubleshoot a drifting position or 3D privacy mask is using fixed positions (the camera is not moving) such as presets and predefined masks on preset positions.

  • How long that is take before the pan and tilt error, the position drifting happens?
     
  • Has this happened since the installation?
     
  • Make sure the pictures are done on predefined scenes such as Presets. Troubleshooting on the same scenes makes it easier.
     
  • Overlay text confirmation is currently the most important tool we need to get a visual confirmation with PTZ coordinates to verify reported issues from our customers. Add coordinates in the overlay Preset #P Pan:#x Tilt:#y Zoom:#z Factor:#Z  %F %X, "Include date" and  "Include time".

Pic 3.0 Data needed

  • Save an image of the scene when the preset is on its initial position, alternative when the privacy masks defined on preset is back on its predefined position.  Download the server report including the image of the initial position.
  • Save an image of the scene when the preset is drifted alternative when the privacy masks defined on preset is drifted.  Download the server report including the image of the position drift.
  • Run a PTZ Test – Manual Pan and Tilt Calibration. Is the position better?
  • Save an image of the scene when the preset is back to its better position alternative when the privacy masks defined on preset is back on its predefined position. Download the server report including the image of the better position.

 

[Please contact technical support with all questions answered and files attached]

Considerations and limitations

The guide does not cover all possible issues but rather the most seen through the support cases. As an Axis Customer you are always welcome to contact Axis Support whenever you need with any type of issues listed or not in this troubleshooting guide.