Controlling-UAV-in-V-REP-via-ROS

A UAV model in V-REP can be controlled using ROS commands in terms of pitch, roll, throttle and yaw.

Follow the steps to control UAV in V-REP using ROS

• Run roscore by typing the following command in your terminal:

roscore

• Launch the simulator by typing ./vrep.sh in the V-REP directory and check if RosInterface is loaded properly
• Drag and drop uav.ttm in the scene
• On running simulation, you can find the following topics /drone_command and /drone_yaw

“/drone_command” is a topic subscribed by the uav model. It commands the uav’s motion in terms of roll, pitch, yaw and throttle. “/drone_yaw” is a topic published by the uav model. It indicates the uav’s orientation about the z-axis with respect to the V-REP world. -Check the structure of the message of /drone_command using the following command:

rostopic type /drone_command | rosmsg show

• Check the structure of the message of /drone_yaw using the following command:

rostopic type /drone_yaw | rosmsg show

Arming the UAV

The condition to arm the uav is rcThrottle = 1000 (minimum value) and rcAUX4 ≥ 1300. To test arming the uav model, publish the following message to the topic “/drone_command” by typing the command:

rostopic pub /drone_command plutodrone/PlutoMsg "{rcRoll: 1500, rcPitch: 1500, rcYaw: 1500, rcThrottle: 1000, rcAUX1: 0, rcAUX2: 0, rcAUX3: 0, rcAUX4: 1500}"

This should now arm the uav. A message should pop on the V-REP window which says “ARMED” and the propellers should start rotating

Flight (Take-Off)

The condition for the uav to take-off is rcThrottle ≥ 1500, after arming. To test the uav’s take-off, publish the following message to increase the throttle:

rostopic pub /drone_command plutodrone/PlutoMsg "{rcRoll: 1500, rcPitch: 1500, rcYaw: 1500, rcThrottle: 1500, rcAUX1: 0, rcAUX2: 0, rcAUX3: 0, rcAUX4: 1500}"

The uav should now steadily rise until a new command is given.

Disarming the UAV

A disarmed uav means the uav is in a mode that will not take any commands from a user or software to fly. The condition to disarm the uav is rcAUX4 ≤ 1200. To test disarming the uav model, publish the following message to the topic “/drone_command” by typing the command:

rostopic pub /drone_command plutodrone/PlutoMsg "{rcRoll: 1500,rcPitch: 1500, rcYaw: 1500, rcThrottle: 1000, rcAUX1: 0, rcAUX2: 0, rcAUX3: 0, rcAUX4: 1200}"

The uav should now be disarmed. A message should pop on the V-REP window which says “DISARMED” and the propellers should stop rotating.

Heading of the UAV

Blue dummy indicates the pitch direction of the uav