Sensors Overview
The ZED family of depth cameras is a multi-sensor platform. The cameras have built-in sensors to add position and motion-assisted capabilities to your app, from accelerometer and gyroscope sensors to temperature, barometer, magnetometer and more.
The sensors can be used to detect camera movements, compute the camera orientation according to the north magnetic pole, detect relative altitude variations, analyze external weather conditions, and much more.
Sensor Availability #
The ZED SDK platform supports several categories of sensors:
The following table summarizes the availability of each sensor on ZED cameras.
| Sensor | ZED 2 | ZED Mini | ZED |
|---|---|---|---|
| Accelerometer | ✔ | ✔ | ✘ |
| Gyroscope | ✔ | ✔ | ✘ |
| Magnetometer | ✔ | ✘ | ✘ |
| Barometer | ✔ | ✘ | ✘ |
| Temperature sensors | ✔ | ✘ | ✘ |
Getting Sensor Data #
You can access these sensors and acquire sensor data by using the Sensors API. The following information is accessible from the camera sensor stack:
| Output Data | Description | Units |
|---|---|---|
| Accelerometer, Gyroscope (IMU) | ||
| linear_acceleration | Acceleration force applied on all three physical axes (x, y, and z), including the force of gravity. Values are corrected from bias, scale and misalignment. | m/s2 |
| linear_acceleration_uncalibrated | Acceleration force applied on all three physical axes (x, y, and z), including the force of gravity. Values are uncalibrated. | m/s2 |
| linear_acceleration_covariance | Measurement noise of the uncalibrated linear acceleration of the accelerometer. Provided as a 3x3 covariance matrix. | |
| angular_velocity | Rate of rotation around each of the three physical axes (x, y, and z). Values are corrected from bias, scale and misalignment. | deg/s |
| angular_velocity_uncalibrated | Rate of rotation around each of the three physical axes (x, y, and z). Values are uncalibrated. | deg/s |
| angular_velocity_covariance | Measurement noise of the uncalibrated angular velocity of the gyroscope. Provided as a 3x3 covariance matrix. | |
| pose | IMU pose in free space, composed of position and orientation. Obtained from the accelerometer and gyroscope sensor fusion. Provided as a Transform. | |
| pose_covariance | Measurement noise of the pose orientation. Provided as a 3x3 covariance matrix. | |
| camera_imu_transform | Transform between IMU and Left Camera frames. | |
| Barometer | ||
| pressure | Ambient air pressure. | hPa |
| relative_altitude | Relative altitude (altitude variation) from the initial camera position. | meters |
| Magnetometer | ||
| magnetic_field_uncalibrated | Ambient geomagnetic field for all three physical axes (x, y, z) in μT. Values are uncalibrated. | μT |
| Temperature Sensors | ||
| temperature_map[ONBOARD_LEFT] | Temperature measured by the onboard temperature sensor located next to the left image sensor. | °C |
| temperature_map[ONBOARD_RIGHT] | Temperature is measured by the onboard temperature sensor located next to the right image sensor. | °C |
| temperature_map[IMU] | IMU temperature. | °C |
| temperature_map[BAROMETER] | Barometer temperature. | °C |
Sensor Capabilities #
The Sensors API provides several classes and interfaces that help you perform a wide variety of sensor-related tasks. For example, you can use the Sensors API to do the following:
- Determine which sensors are available on a device.
- Determine an individual sensor’s capabilities, such as its measurement range, resolution and noise.
- Acquire calibrated or raw sensor data.
- Get sensor hardware location, noise density and bias parameters for visual-inertial fusion.
See Using the API for more information.