The hiwr_tracker ROS package aims to track objects or faces. It uses ROI data provided by another nodes, like hiwr_opencv_detector, and the current states of servomotors. The servomotor data are provided by a ROS dynamixel package. It is fully developed in C++ in order to keep efficiency.

The behavior may be undefined when using two or more identical cameras.

Contributions via pull request are welcome and may be included under the same license as below.

hiwr_camera_controller, except where otherwise noted, is released under the Apache License 2.0. See the LICENSE file located in the root directory.

When this node is running, it takes as an input a Region Of Interest message, and the state of each servomotor, with JointState.msg. Then, according to ROI data and JointState data, we are able to compute a displacement of the ROI from the center of the image. When this displacement is computed, we can set a speed proportional to the distance of the target, and move servomotors to the right direction. This tracking behavior was inspired by rbx1 head_tracker.py.

It requires ROS dynamixel package to work properly.

Make sure that your project is compiled and sourced.

To start hiwr_tracker, do the following (assuming you have a working ROS core running):

Launch using roslaunch:

$ roslaunch hiwr_tracker controller_manager.launch 

Launch from another launchfile:

<include file="$(find hiwr_tracker)/launch/controller_manager.launch" />

• /hiwr_opencv_detector/roi

• The region of interest around the tracked object

• /pan_joint/state

• The [JointState ]((https://github.com/arebgun/dynamixel_motor/blob/master/dynamixel_msgs/msg/JointState.msg) of the pan servomotor

• /tilt_joint/state

• The [JointState ]((https://github.com/arebgun/dynamixel_motor/blob/master/dynamixel_msgs/msg/JointState.msg) of the tilt servomotor

• /pan_joint/command

  • Set the goal angle to reach in radian (Float64)

• /tilt_joint/command

• Set the goal angle to reach in radian (Float64)

• /pan_joint/set_speed

• Set the new speed of the pan joint (Float64)

• /tilt_joint/set_speed

• Set the new speed of the tilt joint (Float64)

• /pan_joint/torque_enable

• Enable or disable pan joint, so it can be moved by hand (Bool)

• /tilt_joint/torque_enable

• Enable or disable tilt joint, so it can be moved by hand (Bool)

• max_joint_speed (float, default= 1)

• define the maximum reachable speed (common to all servos)

• lead_target_angle (float, default= 0.6)

• When we are tracking, move current servo angle to +/- lead_target_angle

• pan_threshold (float, default= 0.25)

• Threshold percentage. Move pan servo if the target exceed the threshold.

• tilt_threshold(float, default= 0.25)

• Threshold percentage. Move tilt servo if the target exceed the threshold.

• gain_pan (float, default= 0.8)

• Adjust pan speed with this multiplicative factor

• gain_tilt (float, default= 0.8)

• Adjust tilt speed with this multiplicative factor

• image_height (int, default= 480)

• Image height of the tracking camera

• image_width (int, default = 640)

• Image with of the tracking camera

• pan_name (string)

• Given name of the pan from dynamixel node

• tilt_name (string)

• Given name of the tilt from dynamixel node

• rate (int, default=5)

• Frequency rate of hiwr_tracking node