** Message數(shù)據(jù)轉(zhuǎn)化**

由于在Matlab中，ROS消息的每個(gè)元素是獨(dú)立的，因此無(wú)法驗(yàn)證具有多個(gè)值在數(shù)學(xué)層面上的有效性。因?yàn)槊總€(gè)值都可以單獨(dú)設(shè)置，所以消息不會(huì)將屬性作為一個(gè)整體進(jìn)行驗(yàn)證。

例如，四元數(shù)消息包含w、x、y和z屬性，但該消息并不強(qiáng)制四元數(shù)作為一個(gè)整體是有效的。所以有可能在單獨(dú)修改一個(gè)四元數(shù)信息后，這個(gè)四元數(shù)是不符合模型的。

同時(shí)消息屬性還可以具有各種數(shù)據(jù)類(lèi)型。MATLAB使用ROS設(shè)置的規(guī)則來(lái)確定這些數(shù)據(jù)類(lèi)型。

為此，這些數(shù)據(jù)類(lèi)型必須映射到MATLAB數(shù)據(jù)類(lèi)型才能在MATLAB中使用。下表總結(jié)了如何將ROS數(shù)據(jù)類(lèi)型轉(zhuǎn)換為MATLAB數(shù)據(jù)類(lèi)型。

同時(shí)在Matlab中也自帶了一些常用的msg包，這些包包含了常用的消息類(lèi)型、服務(wù)類(lèi)型或操作類(lèi)型?？梢栽贛ATLAB命令窗口中調(diào)用rosmsg list查看，當(dāng)然也可以通過(guò)第二講提到的方法。

通過(guò)ROS Toolbox的ROS自定義消息支持來(lái)生成新的消息定義。同時(shí)值得注意的是，在指定消息類(lèi)型時(shí)，輸入字符向量必須與rosmsg列表中列出的字符向量完全匹配。

ackermann_msgs
actionlib
actionlib_msgs
actionlib_tutorials
adhoc_communication
app_manager
applanix_msgs
ar_track_alvar
arbotix_msgs
ardrone_autonomy
asmach_tutorials
audio_common_msgs
axis_camera
base_local_planner
baxter_core_msgs
baxter_maintenance_msgs
bayesian_belief_networks
blob
bond
brics_actuator
bride_tutorials
bwi_planning
bwi_planning_common
calibration_msgs
capabilities
clearpath_base
cmvision
cob_base_drive_chain
cob_camera_sensors
cob_footprint_observer
cob_grasp_generation
cob_kinematics
cob_light
cob_lookat_action
cob_object_detection_msgs
cob_perception_msgs
cob_phidgets
cob_pick_place_action
cob_relayboard
cob_script_server
cob_sound
cob_srvs
cob_trajectory_controller
concert_msgs
control_msgs
control_toolbox
controller_manager_msgs
costmap_2d
create_node
data_vis_msgs
designator_integration_msgs
diagnostic_msgs
dna_extraction_msgs
driver_base
dynamic_reconfigure
dynamic_tf_publisher
dynamixel_controllers
dynamixel_msgs
epos_driver
ethercat_hardware
ethercat_trigger_controllers
ethzasl_icp_mapper
explorer
face_detector
fingertip_pressure
frontier_exploration
gateway_msgs
gazebo_msgs
geographic_msgs
geometry_msgs
gps_common
graft
graph_msgs
grasp_stability_msgs
grasping_msgs
grizzly_msgs
handle_detector
hector_mapping
hector_nav_msgs
hector_uav_msgs
hector_worldmodel_msgs
household_objects_database_msgs
hrpsys_gazebo_msgs
humanoid_nav_msgs
iai_content_msgs
iai_kinematics_msgs
iai_pancake_perception_action
image_cb_detector
image_exposure_msgs
image_view2
industrial_msgs
interaction_cursor_msgs
interactive_marker_proxy
interval_intersection
jaco_msgs
joint_states_settler
jsk_footstep_controller
jsk_footstep_msgs
jsk_gui_msgs
jsk_hark_msgs
jsk_network_tools
jsk_pcl_ros
jsk_perception
jsk_rviz_plugins
jsk_topic_tools
keyboard
kingfisher_msgs
kobuki_msgs
kobuki_testsuite
laser_assembler
laser_cb_detector
leap_motion
linux_hardware
lizi
manipulation_msgs
map_merger
map_msgs
map_store
mavros
microstrain_3dmgx2_imu
ml_classifiers
mln_robosherlock_msgs
mongodb_store
mongodb_store_msgs
monocam_settler
move_base_msgs
moveit_msgs
moveit_simple_grasps
multimaster_msgs_fkie
multisense_ros
nao_interaction_msgs
nao_msgs
nav_msgs
nav2d_msgs
nav2d_navigator
nav2d_operator
navfn
network_monitor_udp
nmea_msgs
nodelet
object_recognition_msgs
octomap_msgs
p2os_driver
pano_ros
pcl_msgs
pcl_ros
pddl_msgs
people_msgs
play_motion_msgs
polled_camera
posedetection_msgs
pr2_calibration_launch
pr2_common_action_msgs
pr2_controllers_msgs
pr2_gazebo_plugins
pr2_gripper_sensor_msgs
pr2_mechanism_controllers
pr2_mechanism_msgs
pr2_msgs
pr2_power_board
pr2_precise_trajectory
pr2_self_test_msgs
pr2_tilt_laser_interface
program_queue
ptu_control
qt_tutorials
r2_msgs
razer_hydra
rmp_msgs
robot_mechanism_controllers
robot_pose_ekf
roboteq_msgs
robotnik_msgs
rocon_app_manager_msgs
rocon_service_pair_msgs
rocon_std_msgs
rosapi
rosauth
rosbridge_library
roscpp
roscpp_tutorials
roseus
rosgraph_msgs
rospy_message_converter
rospy_tutorials
rosruby_tutorials
rosserial_arduino
rosserial_msgs
rovio_shared
rtt_ros_msgs
s3000_laser
saphari_msgs
scanning_table_msgs
scheduler_msgs
schunk_sdh
segbot_gui
segbot_sensors
segbot_simulation_apps
segway_rmp
sensor_msgs
shape_msgs
shared_serial
sherlock_sim_msgs
simple_robot_control
smach_msgs
sound_play
speech_recognition_msgs
sr_edc_ethercat_drivers
sr_robot_msgs
sr_ronex_msgs
sr_utilities
statistics_msgs
std_msgs
std_srvs
stdr_msgs
stereo_msgs
stereo_wall_detection
tf
tf2_msgs
theora_image_transport
topic_proxy
topic_tools
trajectory_msgs
turtle_actionlib
turtlebot_actions
turtlebot_calibration
turtlebot_msgs
turtlesim
um6
underwater_sensor_msgs
universal_teleop
uuid_msgs
velodyne_msgs
view_controller_msgs
visp_camera_calibration
visp_hand2eye_calibration
visp_tracker
visualization_msgs
wfov_camera_msgs
wge100_camera
wifi_ddwrt
wireless_msgs
yocs_msgs
zeroconf_msgs