【kinetic】操作系统探索总结（八）键盘控制

如果尝试过前面的例子，有没有感觉每次让机器人移动还要在终端里输入指令，这也太麻烦了，有没有办法通过键盘来控制机器人的移动呢?答案室当然的了。我研究了其他几个机器人键盘控制的代码，还是有所收获的，最后移植到了smartcar上，实验成功。

　　一、创建控制包

　　首先，我们为键盘控制单独建立一个包：

01.catkin_create_pkg smartcar_teleop rospy geometry_msgs std_msgs roscpp

    02.catkin_make

　　二、简单的消息发布

　　　　在机器人仿真中，主要控制机器人移动的就是 在机器人仿真中，主要控制机器人移动的就是Twist()结构，如果我们编程将这个结构通过程序发布成topic，自然就可以控制机器　　人了。我们先用简单的python来尝试一下。

　　　　之前的模拟中，我们使用的都是在命令行下进行的消息发布，现在我们需要把这些命令转换成python代码，封装到一个单独的节点中去。针对之前的命令行，我们可以很简单的　　在smartcar_teleop/scripts文件夹下编写如下的控制代码:　　

#!/usr/bin/env python
import roslib; roslib.load_manifest('smartcar_teleop')
import rospy
from geometry_msgs.msg import Twist
from std_msgs.msg import String

class Teleop:
    def __init__(self):
        pub = rospy.Publisher('cmd_vel', Twist)
        rospy.init_node('smartcar_teleop')
        rate = rospy.Rate(rospy.get_param('~hz', 1))
        self.cmd = None

        cmd = Twist()
        cmd.linear.x = 0.2
        cmd.linear.y = 0
        cmd.linear.z = 0
        cmd.angular.z = 0
        cmd.angular.z = 0
        cmd.angular.z = 0.5

        self.cmd = cmd
        while not rospy.is_shutdown():
            str = "hello world %s" % rospy.get_time()
            rospy.loginfo(str)
            pub.publish(self.cmd)
            rate.sleep()

if __name__ == '__main__':Teleop()

p { margin-bottom: 0.1in; direction: ltr; line-height: 120%; text-align: justify }
a:link { color: rgba(0, 0, 255, 1) }

　　python代码在ROS重视不需要编译的。(python代码不需要编译但是要给py代码可执行权限chmod +x python.py，运行方式是 rosrun package python.py。C++代码需要catkin_make后rosrun package codes。catkin_make前需要修改CMakeList.txt)

　　先运行之前教程中用到的smartcar机器人，在rviz中进行显示，然后新建终端，输入如下命令：

p { margin-bottom: 0.1in; direction: ltr; line-height: 120%; text-align: justify }
a:link { color: rgba(0, 0, 255, 1) }

　　rosrun smartcar_teleop teleop.py

p { margin-bottom: 0.1in; direction: ltr; line-height: 120%; text-align: justify }
a:link { color: rgba(0, 0, 255, 1) }

　　也可以建立一个launch文件运行：

<launch>
  <arg name="cmd_topic" default="cmd_vel" />
  <node pkg="smartcar_teleop" type="teleop.py" name="smartcar_teleop">
    <remap from="cmd_vel" to="$(arg cmd_topic)" />
  </node>
</launch>

　　使用 roslaunch运行 　　

　　在rviz中看一下机器人是不是动起来了!

三、加入键盘控制

　　当然前边的程序不是我们要的，我们需要的键盘控制。

　　1、移植

　　因为ROS的代码具有很强的可移植性，所以用键盘控制的代码其实可以直接从其他机器人包中移植过来，在这里我主要参考的是erratic_robot，在这个机器人的代码中有一个erratic_teleop包，可以直接移植过来使用。

　　首先，我们将其中src文件夹下的keyboard.cpp代码文件直接拷贝到我们smartcar_teleop包的src文件夹下，然后修改CMakeLists.txt文件，将下列代码加入文件底部：

include_directories(include ${catkin_INCLUDE_DIRS})
add_executable(smartcar_teleop src/keyboard.cpp)
target_link_libraries(smartcar_teleop ${catkin_LIBRARIES})
（注意:不能直接添加在文件底部，可以搜索相似的添加方式，添加在CMakeList.txt的合适位置）

在src文件夹下新建 keyboard.cpp文件。

    #include <termios.h>
    #include <signal.h>
    #include <math.h>
    #include <stdio.h>
    #include <stdlib.h>
    #include <sys/poll.h>  

    #include <boost/thread/thread.hpp>
    #include <ros/ros.h>
    #include <geometry_msgs/Twist.h>  

    #define KEYCODE_W 0x77
    #define KEYCODE_A 0x61
    #define KEYCODE_S 0x73
    #define KEYCODE_D 0x64  

    #define KEYCODE_A_CAP 0x41
    #define KEYCODE_D_CAP 0x44
    #define KEYCODE_S_CAP 0x53
    #define KEYCODE_W_CAP 0x57  

    class SmartCarKeyboardTeleopNode
    {
        private:
            double walk_vel_;
            double run_vel_;
            double yaw_rate_;
            double yaw_rate_run_;  

            geometry_msgs::Twist cmdvel_;
            ros::NodeHandle n_;
            ros::Publisher pub_;       

        public:
            SmartCarKeyboardTeleopNode()
            {
                pub_ = n_.advertise<geometry_msgs::Twist>("cmd_vel", 1);
                ros::NodeHandle n_private("~");
                n_private.param("walk_vel", walk_vel_, 0.5);
                n_private.param("run_vel", run_vel_, 1.0);
                n_private.param("yaw_rate", yaw_rate_, 1.0);
                n_private.param("yaw_rate_run", yaw_rate_run_, 1.5);
            }   

            ~SmartCarKeyboardTeleopNode() { }
            void keyboardLoop();     

            void stopRobot()
            {
                cmdvel_.linear.x = 0.0;
                cmdvel_.angular.z = 0.0;
                pub_.publish(cmdvel_);
            }
    };  

    SmartCarKeyboardTeleopNode* tbk;
    int kfd = 0;
    struct termios cooked, raw;
    bool done;  

    int main(int argc, char** argv)
    {
        ros::init(argc,argv,"tbk", ros::init_options::AnonymousName | ros::init_options::NoSigintHandler);
        SmartCarKeyboardTeleopNode tbk;
        boost::thread t = boost::thread(boost::bind(&SmartCarKeyboardTeleopNode::keyboardLoop, &tbk));     

        ros::spin();
        t.interrupt();
        t.join();
        tbk.stopRobot();
        tcsetattr(kfd, TCSANOW, &cooked);  

        return(0);
    }    

    void SmartCarKeyboardTeleopNode::keyboardLoop()
    {  

        char c;
        double max_tv = walk_vel_;
        double max_rv = yaw_rate_;
        bool dirty = false;
        int speed = 0;
        int turn = 0;    

        // get the console in raw mode
        tcgetattr(kfd, &cooked);
        memcpy(&raw, &cooked, sizeof(struct termios));
        raw.c_lflag &=~ (ICANON | ECHO);
        raw.c_cc[VEOL] = 1;
        raw.c_cc[VEOF] = 2;
        tcsetattr(kfd, TCSANOW, &raw);     

        puts("Reading from keyboard");
        puts("Use WASD keys to control the robot");
        puts("Press Shift to move faster");     

        struct pollfd ufd;
        ufd.fd = kfd;
        ufd.events = POLLIN;    

        for(;;)
        {
            boost::this_thread::interruption_point();
            // get the next event from the keyboard
            int num;  

            if ((num = poll(&ufd, 1, 250)) < 0)
            {
                perror("poll():");
                return;
            }
            else if(num > 0)
            {
                if(read(kfd, &c, 1) < 0)
                {
                    perror("read():");
                    return;
                }
            }
            else
            {
                if (dirty == true)
                {
                    stopRobot();
                    dirty = false;
                }    

                continue;
            }  

            switch(c)
            {
                case KEYCODE_W:
                    max_tv = walk_vel_;
                    speed = 1;
                    turn = 0;
                    dirty = true;
                    break;  

                case KEYCODE_S:
                    max_tv = walk_vel_;
                    speed = -1;
                    turn = 0;
                    dirty = true;
                    break;  

                case KEYCODE_A:
                    max_rv = yaw_rate_;
                    speed = 0;
                    turn = 1;
                    dirty = true;
                    break;  

                case KEYCODE_D:
                    max_rv = yaw_rate_;
                    speed = 0;
                    turn = -1;
                    dirty = true;
                    break;  

                case KEYCODE_W_CAP:
                    max_tv = run_vel_;
                    speed = 1;
                    turn = 0;
                    dirty = true;
                    break;  

                case KEYCODE_S_CAP:
                    max_tv = run_vel_;
                    speed = -1;
                    turn = 0;
                    dirty = true;
                    break;  

                case KEYCODE_A_CAP:
                    max_rv = yaw_rate_run_;
                    speed = 0;
                    turn = 1;
                    dirty = true;
                    break;  

                case KEYCODE_D_CAP:
                    max_rv = yaw_rate_run_;
                    speed = 0;
                    turn = -1;
                    dirty = true;
                    break;                

                default:
                    max_tv = walk_vel_;
                    max_rv = yaw_rate_;
                    speed = 0;
                    turn = 0;
                    dirty = false;
            }
            cmdvel_.linear.x = speed * max_tv;
            cmdvel_.angular.z = turn * max_rv;
            pub_.publish(cmdvel_);
        }
    }

　　CMakeList.txt文件

cmake_minimum_required(VERSION 2.8.3)
project(smartcar_teleop)

## Compile as C++11, supported in ROS Kinetic and newer
# add_compile_options(-std=c++11)

## Find catkin macros and libraries
## if COMPONENTS list like find_package(catkin REQUIRED COMPONENTS xyz)
## is used, also find other catkin packages
find_package(catkin REQUIRED COMPONENTS
  geometry_msgs
  roscpp
  rospy
  std_msgs
  urdf
)

## System dependencies are found with CMake's conventions
# find_package(Boost REQUIRED COMPONENTS system)

## Uncomment this if the package has a setup.py. This macro ensures
## modules and global scripts declared therein get installed
## See http://ros.org/doc/api/catkin/html/user_guide/setup_dot_py.html
# catkin_python_setup()

################################################
## Declare ROS messages, services and actions ##
################################################

## To declare and build messages, services or actions from within this
## package, follow these steps:
## * Let MSG_DEP_SET be the set of packages whose message types you use in
##   your messages/services/actions (e.g. std_msgs, actionlib_msgs, ...).
## * In the file package.xml:
##   * add a build_depend tag for "message_generation"
##   * add a build_depend and a exec_depend tag for each package in MSG_DEP_SET
##   * If MSG_DEP_SET isn't empty the following dependency has been pulled in
##     but can be declared for certainty nonetheless:
##     * add a exec_depend tag for "message_runtime"
## * In this file (CMakeLists.txt):
##   * add "message_generation" and every package in MSG_DEP_SET to
##     find_package(catkin REQUIRED COMPONENTS ...)
##   * add "message_runtime" and every package in MSG_DEP_SET to
##     catkin_package(CATKIN_DEPENDS ...)
##   * uncomment the add_*_files sections below as needed
##     and list every .msg/.srv/.action file to be processed
##   * uncomment the generate_messages entry below
##   * add every package in MSG_DEP_SET to generate_messages(DEPENDENCIES ...)

## Generate messages in the 'msg' folder
# add_message_files(
#   FILES
#   Message1.msg
#   Message2.msg
# )

## Generate services in the 'srv' folder
# add_service_files(
#   FILES
#   Service1.srv
#   Service2.srv
# )

## Generate actions in the 'action' folder
# add_action_files(
#   FILES
#   Action1.action
#   Action2.action
# )

## Generate added messages and services with any dependencies listed here
# generate_messages(
#   DEPENDENCIES
#   geometry_msgs#   std_msgs
# )

################################################
## Declare ROS dynamic reconfigure parameters ##
################################################

## To declare and build dynamic reconfigure parameters within this
## package, follow these steps:
## * In the file package.xml:
##   * add a build_depend and a exec_depend tag for "dynamic_reconfigure"
## * In this file (CMakeLists.txt):
##   * add "dynamic_reconfigure" to
##     find_package(catkin REQUIRED COMPONENTS ...)
##   * uncomment the "generate_dynamic_reconfigure_options" section below
##     and list every .cfg file to be processed

## Generate dynamic reconfigure parameters in the 'cfg' folder
# generate_dynamic_reconfigure_options(
#   cfg/DynReconf1.cfg
#   cfg/DynReconf2.cfg
# )

###################################
## catkin specific configuration ##
###################################
## The catkin_package macro generates cmake config files for your package
## Declare things to be passed to dependent projects
## INCLUDE_DIRS: uncomment this if your package contains header files
## LIBRARIES: libraries you create in this project that dependent projects also need
## CATKIN_DEPENDS: catkin_packages dependent projects also need
## DEPENDS: system dependencies of this project that dependent projects also need
catkin_package(
#  INCLUDE_DIRS include
#  LIBRARIES smartcar_teleop
#  CATKIN_DEPENDS geometry_msgs roscpp rospy std_msgs urdf
#  DEPENDS system_lib
)

###########
## Build ##
###########

## Specify additional locations of header files
## Your package locations should be listed before other locations
include_directories(
 include
  ${catkin_INCLUDE_DIRS}
)

## Declare a C++ library
# add_library(${PROJECT_NAME}
#   src/${PROJECT_NAME}/smartcar_teleop.cpp
# )

## Add cmake target dependencies of the library
## as an example, code may need to be generated before libraries
## either from message generation or dynamic reconfigure
# add_dependencies(${PROJECT_NAME} ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})

## Declare a C++ executable
## With catkin_make all packages are built within a single CMake context
## The recommended prefix ensures that target names across packages don't collide
# add_executable(${PROJECT_NAME}_node src/smartcar_teleop_node.cpp)
add_executable(smartcar_teleop src/keyboard.cpp)

## Rename C++ executable without prefix
## The above recommended prefix causes long target names, the following renames the
## target back to the shorter version for ease of user use
## e.g. "rosrun someones_pkg node" instead of "rosrun someones_pkg someones_pkg_node"
# set_target_properties(${PROJECT_NAME}_node PROPERTIES OUTPUT_NAME node PREFIX "")

## Add cmake target dependencies of the executable
## same as for the library above
# add_dependencies(${PROJECT_NAME}_node ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})

## Specify libraries to link a library or executable target against
# target_link_libraries(${PROJECT_NAME}_node
#   ${catkin_LIBRARIES}
# )

target_link_libraries(smartcar_teleop ${catkin_LIBRARIES})

#############
## Install ##
#############

# all install targets should use catkin DESTINATION variables
# See http://ros.org/doc/api/catkin/html/adv_user_guide/variables.html

## Mark executable scripts (Python etc.) for installation
## in contrast to setup.py, you can choose the destination
# install(PROGRAMS
#   scripts/my_python_script
#   DESTINATION ${CATKIN_PACKAGE_BIN_DESTINATION}
# )

## Mark executables and/or libraries for installation
# install(TARGETS ${PROJECT_NAME} ${PROJECT_NAME}_node
#   ARCHIVE DESTINATION ${CATKIN_PACKAGE_LIB_DESTINATION}
#   LIBRARY DESTINATION ${CATKIN_PACKAGE_LIB_DESTINATION}
#   RUNTIME DESTINATION ${CATKIN_PACKAGE_BIN_DESTINATION}
# )

## Mark cpp header files for installation
# install(DIRECTORY include/${PROJECT_NAME}/
#   DESTINATION ${CATKIN_PACKAGE_INCLUDE_DESTINATION}
#   FILES_MATCHING PATTERN "*.h"
#   PATTERN ".svn" EXCLUDE
# )

## Mark other files for installation (e.g. launch and bag files, etc.)
# install(FILES
#   # myfile1
#   # myfile2
#   DESTINATION ${CATKIN_PACKAGE_SHARE_DESTINATION}
# )

#############
## Testing ##
#############

## Add gtest based cpp test target and link libraries
# catkin_add_gtest(${PROJECT_NAME}-test test/test_smartcar_teleop.cpp)
# if(TARGET ${PROJECT_NAME}-test)
#   target_link_libraries(${PROJECT_NAME}-test ${PROJECT_NAME})
# endif()

## Add folders to be run by python nosetests
# catkin_add_nosetests(test)

　　catkin_make 之后我们执行程序

　　rosrun smartcar_teleop smartcar_teleop
　这样我们就可以用WSAD来控制rviz中的机器人了。


最后附上我自己写的python代码:

#!/usr/bin/env python
#-*- coding:utf-8 -*
import os
import sys
import tty, termios
import roslib; roslib.load_manifest('smartcar_teleop')
import rospy
from geometry_msgs.msg import Twist
from std_msgs.msg import _String

cmd = Twist()
pub = rospy.Publisher('cmd_vel',Twist)

def keyboardLoop():
    rospy.init_node('smartcar_teleop')
    rate = rospy.Rate(rospy.get_param('~hz',1));

    walk_vel_ = rospy.get_param('walk_vel',0.5)
    run_vel_ = rospy.get_param('run_vel',1.0)
    yaw_rate_ = rospy.get_param('yaw_rate',1.0)
    yaw_rate_run_ = rospy.get_param('yaw_rate_run',1.5)

    max_tv = walk_vel_
    max_rv = yaw_rate_

    print "Reading from keyboard"
    print "Use WASD keys to control the robot"
    print "Press Caps to move faster"
    print "Press q to quit"

    while not rospy.is_shutdown():
        fd = sys.stdin.fileno()
        old_settings = termios.tcgetattr(fd)
        old_settings[3] = old_settings[3]&~termios.ICANON&~termios.ECHO

        try:
            tty.setraw(fd)
            ch = sys.stdin.read(1)
        finally:
            termios.tcsetattr(fd,termios.TCSADRAIN,old_settings)

        if ch == 'w':
            max_tv = walk_vel_
            speed = 1
            turn = 0
        elif ch=='s':
            max_tv = walk_vel_
            speed = -1
            turn = 0
        elif ch == 'a':
            max_tv = yaw_rate_
            speed = 0
            turn = 1
        elif ch == 'd':
            max_rv = yaw_rate_
            speed = 0
            turn = -1
        elif ch == 'W':
            max_tv = walk_vel_
            speed = 1
            turn = 0
        elif ch=='S':
            max_tv = walk_vel_
            speed = -1
            turn = 0
        elif ch == 'A':
            max_tv = yaw_rate_
            speed = 0
            turn = 1
        elif ch == 'D':
            max_rv = yaw_rate_
            speed = 0
            turn = -1
        elif ch == 'q':
            exit()
        else:
            max_tv = walk_vel_
            max_rv = yaw_rate_
            speed = 0
            turn = 0

        cmd.linear.x = speed * max_tv
        cmd.angular.z = turn*max_rv
        pub.publish(cmd)
        rate.sleep()

        stop_robot()

def  stop_robot():
    cmd.linear.x=0.0
    cmd.angular.z=0.0
    pub.publish(cmd)

if __name__ == '__main__':
    try:
        keyboardLoop()
    except rospy.ROSInterruptException:
        pass