rostopic命令行工具学习笔记

zxl19 2023-03-06

我的rostopic命令行工具学习笔记。

rostopic Hello World

  1. rostopic命令行工具可以显示关于ROS话题（topic）的信息，包括话题列表、发布者（publisher）、订阅者（subscriber）、频率、带宽、消息（message）内容等；

  2. 语法说明：

     rostopic <subcommand> [options] [args]

  3. 显示帮助信息：

     rostopic -h
 rostopic <subcommand> -h

子命令含义

subcommand 含义
bw Display bandwidth used by topic.
delay Display delay for topic which has header.
echo Print messages to screen.
find Find topics by type.
hz Display publishing rate of topic.
info Print information about active topic.
list Print information about active topics.
pub Publish data to topic.
type Print topic type.

rostopic bw命令

语法说明

rostopic bw [options] topic
  1. 显示的带宽是接收带宽，如果网络连接状况不佳，或者rostopic命令行工具无法跟上发布者，接收带宽可能低于真实带宽；
  2. rostopic命令行工具是基于Python实现的，无法像基于C++实现的ROS节点一样保持高吞吐量（throughput）；

选项含义

options 含义
-w WINDOW_SIZE, --window WINDOW_SIZE Window size, in # of messages, for calculating rate.

rostopic delay命令

语法说明

rostopic delay [options] topic

要求话题中的消息类型包含报头（header）；

选项含义

options 含义
-w WINDOW_SIZE, --window WINDOW_SIZE Window size, in # of messages, for calculating rate.
--tcpnodelay Use the TCP_NODELAY transport hint when subscribing to topics.

rostopic echo命令

语法说明

rostopic echo [options] topic

可以使用/topic/field指定显示话题中的消息字段（field）；

选项含义

options 含义
--offset Display time in messages as offset from current time (e.g. to calculate lag/latency).
--filter Display messages that match a specified Python expression. The Python expression can use any Python builtins plus the variable m (the message).
-c Clear the screen after each message is published. Cannot be used with -p.
-b Display messages in a bag file.
-p Display messages in a matlab/octave-friendly plotting format. Cannot be used with -c.
-w NUM_WIDTH Print all numeric values with a fixed width.
--nostr, -noarr Exclude string and array fields from the plotting output.
-n COUNT Echo COUNT messages and exit.

rostopic find命令

语法说明

rostopic find msg-type

rostopic hz命令

语法说明

rostopic hz [options] topic1 [topic2...]
  1. 显示的是消息的发布频率；
  2. 默认显示命令运行时间内的平均频率；

选项含义

options 含义
-w WINDOW_SIZE Report rate using a window size (number of samples) for a temporally local estimate of the rate.
--filter FILTER_EXPR Only report rate for messages that match the Python FILTER_EXPR. WARNING: this option has a large performance hit and shouldn’t be used for high-rate topics.

rostopic info命令

语法说明

rostopic info topic

rostopic list命令

语法说明

rostopic list [options] [namespace]

namespace参数表示只显示指定命名空间/namespace中的话题名，例如/namespace/***；

选项含义

options 含义
-b List topics in a bag file.
-p List only publishers.
-s List only subscribers.
-v Verbose mode.
--host Group list by hostname.

rostopic pub命令

语法说明

rostopic pub topic type [data...]

可以使用以下三种方法指定话题中发布的消息字段：

# Command-line arguments. Defaults to latch mode.
rostopic pub my_topic std_msgs/String "hello there"
rostopic pub -r 10 /cmd_vel geometry_msgs/Twist \
    '{linear: {x: 0.1, y: 0.0, z: 0.0}, angular: {x: 0.0, y: 0.0, z: 0.0}}'
# Piped input. Defaults to rate mode (10hz). Example usage:
rostopic echo chatter | rostopic pub bar std_msgs/String
# YAML data file. Defaults to rate mode (10hz). Example usage:
rostopic echo chatter > chatter.bagy    # Collect messages, then Ctrl-C
rostopic pub -f chatter.bagy bar std_msgs/String

选项含义

options 含义
-l, --latch Enable latch mode. Latching mode is the default when using command-line arguments.
-r RATE Enable rate mode. Rate mode is the default (10hz) when using piped or file input.
-1, --once Enable once mode.
-f FILE Read message fields from YAML file. YAML syntax is equivalent to output of rostopic echo. Messages are separated using YAML document separator ---. To use only the first message in a file, use the --latch option.

rostopic type命令

语法说明

rostopic type topic

参考

  1. rostopic-ROS Wiki