Thermal Stabilization

Introduction

Starting with SDK v2.7 the Zivid Two has an optional and experimental “Thermal Stabilization”. With “Thermal Stabilization” enabled the Zivid Two will maintain its internal temperature at 36° Celsius. This in turn reduces the impact of temperature dependent performance factors.

Note

Thermal Stabilization is only available for Zivid Two cameras.

Why?

The Zivid cameras uses Temporal Structured Light to produce 3D data. This technology, depends on the position of the projector relative to the camera. As the temperature changes, so does this relative distance. While this is not the only factor that is temperature dependent, it is the most obvious. All Zivid cameras are individually calibrated at multiple temperatures to account for these changes. However, there are still some changes with temperature. The technical datasheet numbers take these changes into account.

In high duty cycle application with a short period there is less thermal variation.

How?

Starting with SDK v2.7 the Zivid Two has an optional “Thermal Stabilization”. This is feature that can be enabled via the configuration file, Config.yml.

The config file contains the following information:

__version__:
    serializer: 1
    data: 15
Configuration:
    Experimental:
        Camera:
            TemperatureStabilization:
                Enabled: yes

Place the config file in the following directory:

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

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

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

While enabled the camera will control internal heatsources and cooling to maintain a constant internal temperature. The primary heatsource is the projector, and the amount of heat generated is controlled by duty-cycling it. This happens in between captures, when the projector is available. In order to reduce light pollution the projected image is black. There is some leakage of light, but it is very minimal. In order to avoid flickering, in the leaked light, the duty-cycling frequency is relatively high.

Tip

Thermal stabilization will provide most value in variable duty cycle applications.

Thermal Stabilization defaults to off when camera powers on.

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

  • Run ZividListCameras

  • Connect via Zivid Studio

  • Run the following line:

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auto camera = zivid.connectCamera();
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var camera = zivid.ConnectCamera();
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camera = app.connect_camera()

Results

With thermal stabilization enabled the Warm-up time is reduced in low-duty cycle applications. This is simply because the thermal stabilization mode emulates a very high duty cycle application when the camera is cold. As the temperature reaches its target the thermal stabilization is adapted to the application duty cycle.

Note

The Thermal Stabilization is configured to keep camera operating parameters, such as temperature and accuracy, in the optimal working range.