Thermal Stabilization

Introduction

Zivid cameras use active Thermal Stabilization to maintain the internal camera temperature steady at 35° Celsius. This feature is on by default and starts when the camera is powered on. It reduces the impact of temperature-dependent factors by reducing temperature fluctuation caused by variable duty cycles. This ensures consistent performance from the beginning to the end of the camera’s working period.

Note

Thermal Stabilization keeps the camera’s temperature and accuracy in the optimal range.

Thermal Stabilization heats the camera when powered on, stops during capture, and resumes heating 10 seconds after the last capture. This reduces the Warm-up time, especially in low-duty cycle applications where the capture cycle is more than 10 seconds.

Note

Running the warm-up process is still necessary because the target temperature may differ from the stabilized temperature. This is crucial before infield correction to ensure optimized trueness.

Why

The Zivid cameras use Temporal Structured Light to produce 3D data. This technology relies on the projector’s position relative to the camera, which can change with temperature. To address this, all Zivid cameras are individually calibrated at multiple temperatures to account for these changes. The technical datasheet numbers take these changes into account. Thermal Stabilization helps to adapt for temperature-dependent variations, reducing thermal variation between active and inactive states.

How it works

Thermal Stabilization regulates the internal camera temperature by duty cycling the projector. This is visible as a weak yellow light from the projector. The duty-cycling frequency is set relatively high both to emulate a high duty cycle application and to avoid flickering in the leaked light.

Note

The small amount of light leakage from the projector is seen as yellow.

Thermal Stabilization helps to maintain the internal temperature of the projector at 35° Celsius, but this depends on the surrounding temperature. If the difference between the ambient temperature and the desired 35° Celsius is too significant, the projector may not reach this target temperature. However, in such cases, the internal temperature will still adjust as close as possible to 35° Celsius. The result is a more consistent temperature control, leading to better performance and trueness for applications with varying levels of activity.

Thermal Stabilization is active from the moment the camera is connected to the power supply and reactivates 10 seconds after its last capture. This means that, if the application has a capture cycle below or equal to 10 seconds, Thermal Stabilization is only on during scheduled pauses.

Warning

There is a switching time penalty to configure the projector from thermal stabilization mode to capture mode. The switching time increases with the length of the projector sequence that is used for capture. The worst case scenario is HDR captures taken with stripe where the time penalty is 40ms.

How to disable it

Thermal Stabilization can be disabled via the configuration file, Config.yml.

If the file already exists and its located in %LOCALAPPDATA%\Zivid\API for Windows or "${XDG_CONFIG_HOME-$HOME/.config}"/Zivid/API for Ubuntu, update it with the following information:

__version__:
    serializer: 1
    data: 16
Configuration:
    Camera:
        TemperatureStabilization:
            Enabled: no

If the Config.yml file does not exist, download it and place it in the following directory:

Windows

mkdir %LOCALAPPDATA%\Zivid\API
move %HOMEPATH%\Downloads\Config.yml %LOCALAPPDATA%\Zivid\API\

Ubuntu

mkdir --parents $XDG_CONFIG_HOME/Zivid/API
mv ~/Downloads/Config.yml $XDG_CONFIG_HOME/Zivid/API/

Caution

If $XDG_CONFIG_HOME is not set use $HOME/.config.

Caution

Any existing Config file will be overwritten.

Caution

Zivid configuration files must use .yml file extension ( not .yaml).

The setting in Config.yml takes effect the first time an instance of the SDK connects to the camera. This can be done in the following way:

• Run ZividListCameras to ensure that the camera is connected

• Run the following lines two lines:

  C++

  

  source

  Zivid::Application zivid;
  

  C#

  

  source

  var zivid = new Zivid.NET.Application();
  

  Python

  

  source

  app = zivid.Application()
  

  C++

  

  source

  auto camera = zivid.connectCamera();
  

  C#

  

  source

  var camera = zivid.ConnectCamera();
  

  Python

  

  source

  camera = app.connect_camera()
  

Version History

SDK	Changes
2.9.0	Thermal stabilization is on by default for Zivid 2 and can be disabled by configuration. Thermal stabilization starts to regulate the internal temperature when the camera is powered on and after 10 seconds of inactivity.
2.7.0	Thermal stabilization is added as an experimental feature that can be enabled.