OAK-D SR PoE

Buy it on Luxonis shop - Early Access

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Overview

The OAK-D SR PoE was designed to provide an accurate short to medium-range depth perception (ideally up to 3m). It’s ideal for applications like bin picking, for pick and place machines, quality control/automated manufacturing, robotics arms, and more.

Besides the stereo camera pair (2x OV9782, 2cm baseline distance) it features ToF sensor which has an ideal range of 20cm to 5m, and depth accuracy of <1% indoors, <2% outdoors.

The OAK-D SR PoE leverages our OAK-SoM-Pro to make an overall compact design. The use of the SoM reduces the design’s scale, making it easier to mount or fit in various robotic processes. The design will also be open-source when we verify the hardware design.

Hardware specifications

This OAK camera uses Power-over-Ethernet (PoE) for communication and power. It offers full 802.3af and Class 3 PoE compliance with 1000BASE-T speeds (1 Gbps). A PoE injector/switch is required to power the device. It also features IP65 rated enclosure.

RVC2 inside

This OAK device is built on top of the RVC2. Main features:

../../_images/SRpoe-back.png

Note that on the schematics below, the enclosure isn’t the same as on the OAK-D SR PoE, but pins/connections are the same.

Connectors

M8 aux connector has 8pin female A-coded connector and the M12 ethernet has 8pin female X-coded connector.

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M12 pin

M8 pin

M8 functionality

1

Eth MX0+

AUX GPIO 3V3

3V3 auxiliary GPIO 52. Pull this pin high with 10k resistor at startup for USB boot.

2

Eth MX0-

FSYNC ISO

Isolated Frame synchronization input signal for cameras

3

Eth MX1+

USB D+

USB 2.0 interface that can be used to connect to the OAK device (eg. reflash) if USB boot is enabled (via AUX GPIO 3V3).

4

Eth MX1-

USB D-

USB 2.0 interface that can be used to connect to the OAK device (eg. reflash) if USB boot is enabled (via AUX GPIO 3V3).

5

Eth MX3+

VBUSIN

This pin is used for sourcing 5V power to accessory devices connected to the M8 connector. If trying to boot the device in USB boot mode, this pin can also sink current.

6

Eth MX3-

Strobe ISO

Isolated Strobe output signal for cameras (Open Collector)

7

Eth MX2+

Isolated GND

Isolated ground for Strobe/FSYNC

8

Eth MX2-

GND

Ground.

Cameras also include an M8 connector cap for waterproofing in case the M8 connector wouldn’t be used.

../../_images/m8-isolated-circiut.png

External triggering: Sensors require 1V8 rising edge on FSYNC for the trigger event. We are using an optocoupler and ESD protection diode, so the input trigger voltage should be 12V (up to 24V) and the trigger logic is reversed, so trigger event happens at 0V on the FSYNC line. For example, see External FSYNC Example.

Camera module specifications

Camera Specs

Stereo pair / Color

ToF

Sensor

OV9782 (color, PY074)

33D ToF

DFOV / HFOV / VFOV

89.5° / 80° / 55°

82.3° / 70° / 54.7°

Resolution

1MP (1280x800)

VGA (640x480)

Range / Focus

FF: 20cm - ∞

20cm - 5m

Max Framerate

120 FPS (800P)

30 FPS (VGA)

Pixel size

3µm x 3µm

7µm x 7µm

Lens size

1/4 inch

1/3.2 inch

F-number

2.0 ±5%

1.45 ± 5%
../../_images/oak-d-sr-poe-sensors.png

Dimensions and Weight

  • Width: 80 mm

  • Height: 52 mm

  • Length: 46 mm

  • Weight: 297g (with enclosure)

Stereo depth perception

This OAK camera has a baseline of 2 cm - the distance between the left and the right stereo camera. Minimal and maximal depth perception (MinZ and Max) depends on camera FOV, resolution, and baseline- more information here.

Note that if you don’t need accurate depth perception below 70cm this OAK camera might not be ideal for your application.

ToF depth perception

Time-of-flight (ToF) technology works by sending out modulated light signal (infrared, at 940nm in our case), which bounces off objects and returns to the sensor. The sensor then measures the time taken by the light to travel back and uses this to calculate the distance (depth) of the object/scene from the sensor.

Specs

Value

Depth range limits

20cm - 5m

Depth accuracy

<1% indoors, <2% outdoors

Depth precision

<0.1%

VSCEL wavelength

940nm

Output interface:

2-lane MIPI

Ideal operating range 1

0°C - 60°C

Operating temperature 2

-20°C to 70°C
1

No visible degradation of the depth quality

2

ToF is still fully functioning

Note that the temperature ranges are for the ToF sensor itself, not for the whole camera. The SoM/RVC2 itself heats up the whole camera quite a bit, and we haven’t yet measured the ambient temperature ranges for the OAK-D SR PoE.

ToF vs Stereo for depth perception

Environment

  • Active stereo cameras can work in low-light conditions but might struggle outside, as dots from dot projector are not visible in sunlight (due to overexposure/saturation)

  • ToF isn’t as affected by the lighting conditions; it works in low-light environments and outside (a lot of light) as well

Depth error

  • Stereo depth cameras usually have below 3% of depth error. Its depth error increases exponentially with distance.

  • ToF sensors have a depth error of <1% indoors, <2% outdoors. Its depth error doesn’t increase exponentially with distance.

Potential Stereo issues

Potential ToF issues

  • Issues when using multiple ToFs (interference)

  • Reflective surfaces / Transparent surfaces

  • Multiple-path reflections (where the light bounces off multiple surfaces before returning to the sensor)

  • Limited resolution: 640x480, which is considered quite high among ToF sensors.

Open Source Hardware

This hardware design is open source, and all design files are available on GitHub.

Got questions?

Head over to Discussion Forum for technical support or any other questions you might have.