Input to the system includes cameras, Game Controller and NatNet.
Cameras
The cameras have the following parameters that are used by the object detection algorithm.
| Parameter | Type | Description |
|---|---|---|
serial_number | string | The serial number of the camera. This is used to identify the camera and distinguish it from other cameras in the robot. |
lens.projection | string | The lens projection type. Can be rectilinear, equidistant or equisold. |
lens.focal_length | float | The normalised focal length. It is defined as focal length in pixels divided by image width. The focal length is the angle of view and magnification. |
lens.center | 2-dimensional vector | The normalised image centre offset. Represents the pixels from the centre of the image to the optical axis, divided by the image width |
k | 2-dimensional vector | The polynomial distortion coefficients for the length |
fov | float (radians) | Field of view. The angular diameter that the lens covers (the area that light hits on the sensor). |
Hpc | 4x4 matrix | Homogeneous transform from the rigid platform this camera is attached to (pitch servo) to the camera's virtual focal point. |
These parameters are set for each camera as configuration values in the Camera module, in each robot's respective folder. The values for the left camera on the robot will be stored in Left.yaml. The values for the right camera on the robot will be stored in Right.yaml.
The parameters are used in the Camera module to find and set up the cameras. The Camera module emits Image messages.
The projection tool, based on panotools' fisheye projection calculations, maps a portion of the surface of a sphere to a flat image. The type of projection is specified by the above parameter lens.projection.
