gimbal_controller

Gimbal Controller

The current package controls the orientation of a gimbal system built with 2 servos Dynamixel xl430-w250-t, the hardware interface used to communicate the servos with the Jetson Nano is the OpenCR 2.0.

1. Prerequisites

The servos driver and communication packages are required to run the current module. The sofware dependencies are described in the dynamixel interface respository. The current package requires the sensor information from BNO055 IMU, the sensor driver is found in the ros_imu_bno055 repository.

2. Build gimbal_controller package

Clone the respository in your default environment folder (in this example catkin_ws):

  cd ~/catkin_ws/src
  git clone https://github.com/hl49/uav_gimbal.git
  cd ../
  catkin_make
  source ~/catkin_ws/devel/setup.bash

Allow execution permission to the gimbal_controller_node.py file

  cd ~/catkin_ws/src/uav_gimbal/gimbal_controller/scripts
  chmod +x gimbal_controller_node.py

3. Running the Gimbal Controller Node

3.1 Connect the Opencr to the pc, and turn on the servo power supply.

3.2 Run the BNO055 ros node to read the data from the inertial sensor:

rosrun bno055 bno055_ros.py

3.3 Run the custom launch file required to initialize the servo driver:

roslaunch gimbal_controller dynamixel_interface_controller.launch

3.4 Run the controller node:

rosrun gimbal_controller gimbal_controller_node.py

3.5 Position reference from input topics

The gimbal controller keeps the initial position until a reference position is sent through perception node and bno055 ros. The gimbal_controller_node subcribes to the topics /perception_rpy and /imu/data. The first topic provides reference position relative to the skyline processed by the perception node, and the second topic contains the imu measurements published by the ros_imu_bno055 node.