EWOK报错

问题：

ERROR: cannot launch node of type [ewok_simulation/ewok_simulation]: Cannot locate node of type [ewok_simulation] in package [ewok_simulation]. Make sure file exists in package path and permission is set to executable (chmod +x)
ERROR: cannot launch node of type [ewok_simulation/trajectory_replanning_example]: Cannot locate node of type [trajectory_replanning_example] in package [ewok_simulation]. Make sure file exists in package path and permission is set to executable (chmod +x)
ERROR: cannot launch node of type [robot_state_publisher/robot_state_publisher]: robot_state_publisher
ROS path [0]=/opt/ros/melodic/share/ros
ROS path [1]=/home/labh/ewok_ws/src
ROS path [2]=/home/labh/xtdrone_ws/src/VINS-Fusion/camera_models
ROS path [3]=/home/labh/xtdrone_ws/src/ego_planner/Utils/cmake_utils
ROS path [4]=/home/labh/xtdrone_ws/src/ego_planner/drone_detect
ROS path [5]=/home/labh/xtdrone_ws/src/gazebo_ros_pkgs/gazebo_dev
ROS path [6]=/home/labh/xtdrone_ws/src/gazebo_ros_pkgs/gazebo_msgs
ROS path [7]=/home/labh/xtdrone_ws/src/gazebo_ros_pkgs/gazebo_ros
ROS path [8]=/home/labh/xtdrone_ws/src/gazebo_ros_pkgs/gazebo_plugins
ROS path [9]=/home/labh/xtdrone_ws/src/gazebo_ros_pkgs/gazebo_ros_control
ROS path [10]=/home/labh/xtdrone_ws/src/gazebo_ros_pkgs/gazebo_ros_pkgs
ROS path [11]=/home/labh/xtdrone_ws/src/VINS-Fusion/global_fusion
ROS path [12]=/home/labh/xtdrone_ws/src/VINS-Fusion/loop_fusion
ROS path [13]=/home/labh/xtdrone_ws/src/ego_planner/plan_env
ROS path [14]=/home/labh/xtdrone_ws/src/ego_planner/path_searching
ROS path [15]=/home/labh/xtdrone_ws/src/ego_planner/Utils/pose_utils
ROS path [16]=/home/labh/xtdrone_ws/src/ego_planner/Utils/odom_visualization
ROS path [17]=/home/labh/xtdrone_ws/src/ego_planner/Utils/quadrotor_msgs
ROS path [18]=/home/labh/xtdrone_ws/src/ego_planner/Utils/multi_map_server
ROS path [19]=/home/labh/xtdrone_ws/src/ego_planner/Utils/rviz_plugins
ROS path [20]=/home/labh/xtdrone_ws/src/ego_planner/traj_utils
ROS path [21]=/home/labh/xtdrone_ws/src/ego_planner/bspline_opt
ROS path [22]=/home/labh/xtdrone_ws/src/ego_planner/plan_manage
ROS path [23]=/home/labh/xtdrone_ws/src/ego_planner/rosmsg_tcp_bridge
ROS path [24]=/home/labh/xtdrone_ws/src/ego_planner/Utils/uav_utils
ROS path [25]=/home/labh/xtdrone_ws/src/VINS-Fusion/vins_estimator
ROS path [26]=/home/labh/xtdrone_ws/src/ego_planner/Utils/waypoint_generator
ROS path [27]=/home/labh/bnuk_ws/src
ROS path [28]=/opt/ros/melodic/share
ERROR: cannot launch node of type [joint_state_publisher/joint_state_publisher]: joint_state_publisher
ROS path [0]=/opt/ros/melodic/share/ros
ROS path [1]=/home/labh/ewok_ws/src
ROS path [2]=/home/labh/xtdrone_ws/src/VINS-Fusion/camera_models
ROS path [3]=/home/labh/xtdrone_ws/src/ego_planner/Utils/cmake_utils
ROS path [4]=/home/labh/xtdrone_ws/src/ego_planner/drone_detect
ROS path [5]=/home/labh/xtdrone_ws/src/gazebo_ros_pkgs/gazebo_dev
ROS path [6]=/home/labh/xtdrone_ws/src/gazebo_ros_pkgs/gazebo_msgs
ROS path [7]=/home/labh/xtdrone_ws/src/gazebo_ros_pkgs/gazebo_ros
ROS path [8]=/home/labh/xtdrone_ws/src/gazebo_ros_pkgs/gazebo_plugins
ROS path [9]=/home/labh/xtdrone_ws/src/gazebo_ros_pkgs/gazebo_ros_control
ROS path [10]=/home/labh/xtdrone_ws/src/gazebo_ros_pkgs/gazebo_ros_pkgs
ROS path [11]=/home/labh/xtdrone_ws/src/VINS-Fusion/global_fusion
ROS path [12]=/home/labh/xtdrone_ws/src/VINS-Fusion/loop_fusion
ROS path [13]=/home/labh/xtdrone_ws/src/ego_planner/plan_env
ROS path [14]=/home/labh/xtdrone_ws/src/ego_planner/path_searching
ROS path [15]=/home/labh/xtdrone_ws/src/ego_planner/Utils/pose_utils
ROS path [16]=/home/labh/xtdrone_ws/src/ego_planner/Utils/odom_visualization
ROS path [17]=/home/labh/xtdrone_ws/src/ego_planner/Utils/quadrotor_msgs
ROS path [18]=/home/labh/xtdrone_ws/src/ego_planner/Utils/multi_map_server
ROS path [19]=/home/labh/xtdrone_ws/src/ego_planner/Utils/rviz_plugins
ROS path [20]=/home/labh/xtdrone_ws/src/ego_planner/traj_utils
ROS path [21]=/home/labh/xtdrone_ws/src/ego_planner/bspline_opt
ROS path [22]=/home/labh/xtdrone_ws/src/ego_planner/plan_manage
ROS path [23]=/home/labh/xtdrone_ws/src/ego_planner/rosmsg_tcp_bridge
ROS path [24]=/home/labh/xtdrone_ws/src/ego_planner/Utils/uav_utils
ROS path [25]=/home/labh/xtdrone_ws/src/VINS-Fusion/vins_estimator
ROS path [26]=/home/labh/xtdrone_ws/src/ego_planner/Utils/waypoint_generator
ROS path [27]=/home/labh/bnuk_ws/src
ROS path [28]=/opt/ros/melodic/share

解决方法：

sudo apt-get install ros-melodic-robot-state-publisher

sudo apt-get install ros-melodic-joint-state-publisher