PTZ Action Server

This repo contains both generic action messages for controlling PTZ and PTU devices, as well as middle-ware ROS packages designed to wrap hardware/vendor-specific drivers and provide a more universal interface

ptz_action_server_msgs

This package contains the core ActionLib compatible messages that compatible ROS nodes should use. To allow easy inter-operability, the action server should be implemented to support these conditions, regardless of the underlying hardware:

• pan and tilt are expressed in radians
• pan has a maximum allowable range of -pi to +pi, though cameras with a restricted field of motion may support a subset of that range
• tilt has a maximum allowable range of -pi/2 to +pi/2, though cameras with a restricted field of motion may suport a subset of that range
• positive pan indicates clockwise rotation, negative pan indicates anticlockwise rotation when the camera is viewed from above
• positive tilt will pitch the camera upwards, negative tilt will pitch the camera downwards
• zoom is the X-factor of the camera's zoom range. For example, a camera with a 1-24x zoom shall accept zoom values in the range of 1-24.
• if the camera does not support zoom (e.g. the Flir D46 PTU), the zoom field is ignored
• while the action is ongoing feedback shall be published at no less than 1Hz, underlying hardware permitting
• preemption should be allowed if possible, but may not be supported by the underlying hardware.
• the action server will publish the state of the PTZ camera in the above logical angles/ranges at a rate of no less than 1Hz.

The main action server uses the following message format:

# Ptz.action
float32 pan
float32 tilt
float32 zoom
---
bool success
---
float32 pan_remaining
float32 tilt_remaining
float32 zoom_remaining

The current state of the camera is reported using the following message format:

# PtzState.msg
int8 MODE_IDLE=0
int8 MODE_POSITION=1
int8 MODE_VELOCITY=2

int8 mode

float32 pan
float32 tilt
float32 zoom

Regardless of the operating mode, the pan, tilt, and zoom fields report the current positions of the camera.

Supported Implementations

This repository contains action server implementations that communicate with underlying ROS hardware drivers:

• axiz_ptz_action_server: interacts with the axis_camera driver, supporting most Axis PTZ cameras that use ethernet
• flir_ptu_action_server: interacts with the Flir D46 and E46 PTUs, supported by the flir_ptu package, either over serial or ethernet.