Using MoveIt with ros_control - why are /joint_states all zero?

Hi, I'm having real difficulty configuring MoveIt with ros_control for my robot. I have used the SetupAssistant to create a config package, then have made some of my own launch and config files following tutorials. I have managed to get to the point where everything seems to launch successfully with no errors, but when I echo /joint_states or publish the joint positions that I am getting in my RobotHW class, I am getting a constant array of zeros, even though I am executing a goal in RViz. Interestingly, if I echo /arm_joint_controller/follow_joint_trajectory/goal, then this does seem to give me a series of joint positions when a goal is executed. I have included my main launch and configuration files below. If there is any other info which would help please let me know and I will include it. If anyone could take a look and tell me where I'm going wrong I would be eternally grateful - after many hours it's starting to drive me mad! :p Thanks. spawn_bolt_arm.launch: arm_joint_publisher.launch: arm_trajectory_controller.launch: moveit_planning_execution.launch: bolt_arm_moveit_controller_manager.launch.xml: arm_joint_states.yaml: arm_joint_publisher: type: "joint_state_controller/JointStateController" publish_rate: 50 arm_trajectory_control.yaml: arm_joint_controller: type: "position_controllers/JointTrajectoryController" joints: - base_joint - shoulder_joint - elbow_joint - wrist_joint - wrist_rotate_joint gripper_joint_controller: type: "position_controllers/JointTrajectoryController" joints: - left_gripper_joint - right_gripper_joint controllers.yaml: controller_manager_ns: controller_manager controller_list: - name: arm_joint_controller action_ns: follow_joint_trajectory type: FollowJointTrajectory default: true joints: - base_joint - shoulder_joint - elbow_joint - wrist_joint - wrist_rotate_joint - name: gripper_joint_controller action_ns: follow_joint_trajectory type: FollowJointTrajectory default: true joints: - left_gripper_joint - right_gripper_joint