DiffDriveController (Skid Steering) isn't publishing to /cmd_vel

Hello! I'm new to ROS and gazebo, and I've been facing some problems while trying to implement skid steering on my robot. Mainly, I am unable to move the robot at all. I tried to follow similar format to what was done on Jackal. I am running ROS Melodic on Ubuntu 18.04.02 bionic This is my transmission tag for the wheels: transmission_interface/SimpleTransmissionhardware_interface/VelocityJointInterfacehardware_interface/VelocityJointInterface1 This is my yaml file: rover_joint_publisher: type: "joint_state_controller/JointStateController" publish_rate: 50 rover_velocity_controller: type: "diff_drive_controller/DiffDriveController" left_wheel: ['front_left_wheel', 'rear_left_wheel'] right_wheel: ['front_right_wheel', 'rear_right_wheel'] publish_rate: 50 pose_covariance_diagonal: [0.001, 0.001, 1000000.0, 1000000.0, 1000000.0, 0.03] twist_covariance_diagonal: [0.001, 0.001, 0.001, 1000000.0, 1000000.0, 0.03] cmd_vel_timeout: 0.25 velocity_rolling_window_size: 2 k_l: 0.1 k_r: 0.1 # Base frame_id base_frame_id: body # Odometry fused with IMU is published by robot_localization, so # no need to publish a TF based on encoders alone. enable_odom_tf: false # Wheel separation and radius multipliers wheel_separation_multiplier: 1.5 # default: 1.0 wheel_radius_multiplier : 1.0 # default: 1.0 # Velocity and acceleration limits # Whenever a min_* is unspecified, default to -max_* linear: x: has_velocity_limits : true max_velocity : 1.0 # m/s has_acceleration_limits: true max_acceleration : 3.0 # m/s^2 angular: z: has_velocity_limits : true max_velocity : 2.0 # rad/s has_acceleration_limits: true max_acceleration : 6.0 # rad/s^2 Since I've encountered some errors regarding the PID gains not being set, I have created a pid.yaml file and specified arbitrary pid gains: /rover/gazebo_ros_control: pid_gains: front_left_wheel_joint: p: 1.0 i: 0.0 d: 0.0 front_right_wheel_joint: p: 1.0 i: 0.0 d: 0.0 rear_left_wheel_joint: p: 1.0 i: 0.0 d: 0.0 rear_right_wheel_joint: p: 1.0 i: 0.0 d: 0.0 Afterwards, I loaded both files into launch file, spawned the controllers and started EKF localization: After launching on Gazebo, I can see that the robot is slowly dragging forward on its own. This is due to the set PID gain. If I increase the proportional gain then it moves faster. I'm not sure what exactly is the problem, but I feel that the DiffDriveController isnt publishing to the /rover/cmd_vel. These are the listed active topics: /client_count /clock /connected_clients /diagnostics /gazebo/link_states /gazebo/model_states /gazebo/parameter_descriptions /gazebo/parameter_updates /gazebo/set_link_state /gazebo/set_model_state /imu/data /odometry/filtered /rosout /rosout_agg /rover/camera1/camera1_info /rover/camera1/image_raw /rover/camera1/image_raw/compressed /rover/camera1/image_raw/compressed/parameter_descriptions /rover/camera1/image_raw/compressed/parameter_updates /rover/camera1/image_raw/compressedDepth /rover/camera1/image_raw/compressedDepth/parameter_descriptions /rover/camera1/image_raw/compressedDepth/parameter_updates /rover/camera1/image_raw/theora /rover/camera1/image_raw/theora/parameter_descriptions /rover/camera1/image_raw/theora/parameter_updates /rover/camera1/parameter_descriptions /rover/camera1/parameter_updates /rover/camera2/camera2_info /rover/camera2/image_raw /rover/camera2/image_raw/compressed /rover/camera2/image_raw/compressed/parameter_descriptions /rover/camera2/image_raw/compressed/parameter_updates /rover/camera2/image_raw/compressedDepth /rover/camera2/image_raw/compressedDepth/parameter_descriptions /rover/camera2/image_raw/compressedDepth/parameter_updates /rover/camera2/image_raw/theora /rover/camera2/image_raw/theora/parameter_descriptions /rover/camera2/image_raw/theora/parameter_updates /rover/camera2/parameter_descriptions /rover/camera2/parameter_updates /rover/cmd_vel /rover/gazebo_ros_control/pid_gains/front_left_wheel_joint/parameter_descriptions /rover/gazebo_ros_control/pid_gains/front_left_wheel_joint/parameter_updates /rover/gazebo_ros_control/pid_gains/front_right_wheel_joint/parameter_descriptions /rover/gazebo_ros_control/pid_gains/front_right_wheel_joint/parameter_updates /rover/gazebo_ros_control/pid_gains/rear_left_wheel_joint/parameter_descriptions /rover/gazebo_ros_control/pid_gains/rear_left_wheel_joint/parameter_updates /rover/gazebo_ros_control/pid_gains/rear_right_wheel_joint/parameter_descriptions /rover/gazebo_ros_control/pid_gains/rear_right_wheel_joint/parameter_updates /rover/imu /rover/laser/scan /rover_velocity_controller/odom /set_pose /tf /tf_static Any help would be appreciated. Thanks!