通常情况下，对于机械臂的笛卡尔系下的控制或者小车的控制，我们在测试的时候可以通过键盘来实现，以下给出博主在网上找到的源码，能避免重复造轮子，更快的达到键盘控制的目的。

值得注意的是，以下代码左右键均是小车控制的代码，左右方向控制的是theta，因此对于机械臂的笛卡尔系控制还需要进一步修改代码。

1. 键盘控制C++实现(x、y、z、theta)

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说明： 在终端中按下键盘里的“W”、“S”、“D”、“A”以及“Shift”键进行机器人的控制¹。

---

/** =====================================================================================*        COPYRIGHT NOTICE*        Copyright (c) 2013  HUST-Renesas Lab*        ALL rights reserved.*//**        *        @file     keyboard.cpp*        @brief    robot keyboard control*        @version  0.1*        @date     2013/5/23 15:22:40*        @author   Hu Chunxu , huchunxu@hust.edu.cn*//* ==================================================================================*  @0.1    Hu Chunxu    2013/5/23 15:22:40   create orignal file* =====================================================================================*/#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/* 带有shift键 */
#define KEYCODE_A_CAP 0x41
#define KEYCODE_D_CAP 0x44
#define KEYCODE_S_CAP 0x53
#define KEYCODE_W_CAP 0x57class 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;/*** 文件描述符* 内核（kernel）利用文件描述符（file descriptor）来访问文件。文件描述符是非负整数。* 标准输入（standard input）的文件描述符是 0，标准输出（standard output）是 1，标准错误（standard error）是 2。*/
int kfd = 0;/** *  === struct termios ===*  tcflag_t c_iflag;  输入模式*　tcflag_t c_oflag;  输出模式 *　tcflag_t c_cflag;  控制模式 *  tcflag_t c_lflag;  本地模式*  cc_t c_cc[NCCS];   控制字符 */
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;/* 创建一个新的线程 */boost::thread t = boost::thread(boost::bind(&SmartCarKeyboardTeleopNode::keyboardLoop, &tbk));ros::spin();t.interrupt();t.join();tbk.stopRobot();/* 设置终端参数 */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;/** * 从终端中获取按键 * int tcgetattr(int fd, struct termios *termios_p);*/tcgetattr(kfd, &cooked);memcpy(&raw, &cooked, sizeof(struct termios));/*** c_lflag : 本地模式标志，控制终端编辑功能* ICANON: 使用标准输入模式* ECHO: 显示输入字符*/raw.c_lflag &=~ (ICANON | ECHO);/** * c_cc[NCCS]：控制字符，用于保存终端驱动程序中的特殊字符，如输入结束符等* VEOL: 附加的End-of-file字符* VEOF: End-of-file字符* */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 {int fd;        文件描述符 short events;  等待的事件 short revents; 实际发生了的事件 };*/struct pollfd ufd;ufd.fd = kfd;ufd.events = POLLIN;for(;;){boost::this_thread::interruption_point();/* get the next event from the keyboard */int num;/*** poll:把当前的文件指针挂到设备内部定义的等待队列中。* unsigned int (*poll)(struct file * fp, struct poll_table_struct * table)*/if ((num = poll(&ufd, 1, 250)) < 0){/*** perror( ) 用来将上一个函数发生错误的原因输出到标准设备(stderr)。* 参数s所指的字符串会先打印出,后面再加上错误原因字符串。* 此错误原因依照全局变量errno 的值来决定要输出的字符串。* */perror("poll():");return;}else if(num > 0){if(read(kfd, &c, 1) < 0){perror("read():");return;}}else{/* 每按下一次动一下 */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_);}
}

2. 键盘控制Python实现(x、y、z、theta)

代码1

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说明： 在终端中按下键盘里的“W”、“S”、“D”、“A”以及“Shift”键进行机器人的控制¹。

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#!/usr/bin/env python
# -*- coding: utf-8 -*
# =====================================================================================
#        COPYRIGHT NOTICE
#        Copyright (c) 2013  HUST-Renesas Lab
#        ALL rights reserved.
#        
#        @file     teleop
#        @brief    robot keyboard control
#        @version  0.1
#        @date     2013/5/23 15:34:40
#        @author   Hu Chunxu , huchunxu@hust.edu.cn
# ==================================================================================
#  @0.1    Hu Chunxu    2013/5/23   create orignal file
# =====================================================================================
import  os
import  sys
import  tty, termiosimport roslib; roslib.load_manifest('smartcar_teleop')
import rospy
from geometry_msgs.msg import Twist
from std_msgs.msg import String# 全局变量
cmd = Twist()
pub = rospy.Publisher('cmd_vel', Twist)def keyboardLoop():#初始化rospy.init_node('smartcar_teleop')# Set rospy to exectute a shutdown function when exiting       rate = rospy.Rate(rospy.get_param('~hz', 1))#速度变量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_#显示提示信息print "Reading from keyboard"print "Use WASD keys to control the robot"print "Press Caps to move faster"print "Press q to quit"#读取按键循环while not rospy.is_shutdown():fd = sys.stdin.fileno()old_settings = termios.tcgetattr(fd)#不产生回显效果old_settings[3] = old_settings[3] & ~termios.ICANON & ~termios.ECHOtry :tty.setraw( fd )ch = sys.stdin.read( 1 )finally :termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)if ch == 'w':max_tv = walk_vel_speed = 1turn = 0elif ch == 's':max_tv = walk_vel_speed = -1turn = 0elif ch == 'a':max_rv = yaw_rate_speed = 0turn = 1elif ch == 'd':max_rv = yaw_rate_speed = 0turn = -1elif ch == 'W':max_tv = run_vel_speed = 1turn = 0elif ch == 'S':max_tv = run_vel_speed = -1turn = 0elif ch == 'A':max_rv = yaw_rate_run_speed = 0turn = 1elif ch == 'D':max_rv = yaw_rate_run_speed = 0turn = -1elif ch == 'q':exit()else:max_tv = walk_vel_max_rv = yaw_rate_speed = 0turn = 0#发送消息cmd.linear.x = speed * max_tv;cmd.angular.z = turn * max_rv;pub.publish(cmd)rate.sleep()#停止机器人stop_robot();def stop_robot():cmd.linear.x = 0.0cmd.angular.z = 0.0pub.publish(cmd)if __name__ == '__main__':try:keyboardLoop()except rospy.ROSInterruptException:pass

代码2

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说明²：

For Holonomic mode (strafing), hold down the shift key:

U ---------- I ---------- O
J ---------- K ---------- L
M ---------- < ---------- >

t : up (+z)

b : down (-z)

其他按键 : stop

q/z : 最大速度增加/减少10%
w/x : 仅线性速度增加/减少10%
e/c : 只增加/减少角速度10%

CTRL-C 退出

---

#!/usr/bin/env python
# -*- coding: utf-8 -*from __future__ import print_functionimport roslib; roslib.load_manifest('teleop_twist_keyboard')
import rospyfrom geometry_msgs.msg import Twistimport sys, select, termios, ttymsg = """
Reading from the keyboard  and Publishing to Twist!
---------------------------
Moving around:u    i    oj    k    lm    ,    .For Holonomic mode (strafing), hold down the shift key:
---------------------------U    I    OJ    K    LM    <    >t : up (+z)
b : down (-z)anything else : stopq/z : increase/decrease max speeds by 10%
w/x : increase/decrease only linear speed by 10%
e/c : increase/decrease only angular speed by 10%CTRL-C to quit
"""moveBindings = {'i':(1,0,0,0),'o':(1,0,0,-1),'j':(0,0,0,1),'l':(0,0,0,-1),'u':(1,0,0,1),',':(-1,0,0,0),'.':(-1,0,0,1),'m':(-1,0,0,-1),'O':(1,-1,0,0),'I':(1,0,0,0),'J':(0,1,0,0),'L':(0,-1,0,0),'U':(1,1,0,0),'<':(-1,0,0,0),'>':(-1,-1,0,0),'M':(-1,1,0,0),'t':(0,0,1,0),'b':(0,0,-1,0),}speedBindings={'q':(1.1,1.1),'z':(.9,.9),'w':(1.1,1),'x':(.9,1),'e':(1,1.1),'c':(1,.9),}def getKey():tty.setraw(sys.stdin.fileno())select.select([sys.stdin], [], [], 0)key = sys.stdin.read(1)termios.tcsetattr(sys.stdin, termios.TCSADRAIN, settings)return keydef vels(speed,turn):return "currently:\tspeed %s\tturn %s " % (speed,turn)if __name__=="__main__":settings = termios.tcgetattr(sys.stdin)pub = rospy.Publisher('cmd_vel', Twist, queue_size = 1)rospy.init_node('teleop_twist_keyboard')speed = rospy.get_param("~speed", 0.5)turn = rospy.get_param("~turn", 1.0)x = 0y = 0z = 0th = 0status = 0try:print(msg)print(vels(speed,turn))while(1):key = getKey()if key in moveBindings.keys():x = moveBindings[key][0]y = moveBindings[key][1]z = moveBindings[key][2]th = moveBindings[key][3]elif key in speedBindings.keys():speed = speed * speedBindings[key][0]turn = turn * speedBindings[key][1]print(vels(speed,turn))if (status == 14):print(msg)status = (status + 1) % 15else:x = 0y = 0z = 0th = 0if (key == '\x03'):breaktwist = Twist()twist.linear.x = x*speed; twist.linear.y = y*speed; twist.linear.z = z*speed;twist.angular.x = 0; twist.angular.y = 0; twist.angular.z = th*turnpub.publish(twist)except Exception as e:print(e)finally:twist = Twist()twist.linear.x = 0; twist.linear.y = 0; twist.linear.z = 0twist.angular.x = 0; twist.angular.y = 0; twist.angular.z = 0pub.publish(twist)termios.tcsetattr(sys.stdin, termios.TCSADRAIN, settings)

3.键盘笛卡尔方向控制(x、y、z)

基于2中的代码2来实现

#!/usr/bin/env python
# -*- coding: utf-8 -*from __future__ import print_functionimport roslib; roslib.load_manifest('teleop_twist_keyboard')
import rospyfrom geometry_msgs.msg import Twistimport sys, select, termios, ttymsg = """
---------------------------I     J    K    L<     I : +x		J : +y		T : +z
< : -x		L : -y		B : -zK : stop其他按键 : stopq/z : 最大速度增加/减少10%
w/x : 仅线性速度增加/减少10%
e/c : 只增加/减少角速度10%CTRL-C 退出
---------------------------
"""moveBindings = {'i':(1,0,0,0),'j':(0,1,0,0),'l':(0,-1,0,0),',':(-1,0,0,0),'I':(1,0,0,0),'J':(0,1,0,0),'L':(0,-1,0,0),'<':(-1,0,0,0),'t':(0,0,1,0),'b':(0,0,-1,0),'T':(0,0,1,0),'B':(0,0,-1,0),}speedBindings={'q':(1.1,1.1),'z':(.9,.9),'w':(1.1,1),'x':(.9,1),'e':(1,1.1),'c':(1,.9),}def getKey():tty.setraw(sys.stdin.fileno())select.select([sys.stdin], [], [], 0)key = sys.stdin.read(1)termios.tcsetattr(sys.stdin, termios.TCSADRAIN, settings)return keydef vels(speed,turn):return "currently:\tspeed %s\tturn %s " % (speed,turn)if __name__=="__main__":settings = termios.tcgetattr(sys.stdin)pub = rospy.Publisher('cmd_vel', Twist, queue_size = 1)rospy.init_node('teleop_twist_keyboard')speed = rospy.get_param("~speed", 0.05)turn = rospy.get_param("~turn", 0.1)x = 0y = 0z = 0th = 0status = 0try:print(msg)print(vels(speed,turn))while(1):key = getKey()if key in moveBindings.keys():x = moveBindings[key][0]y = moveBindings[key][1]z = moveBindings[key][2]th = moveBindings[key][3]elif key in speedBindings.keys():speed = speed * speedBindings[key][0]turn = turn * speedBindings[key][1]print(vels(speed,turn))if (status == 14):print(msg)status = (status + 1) % 15else:x = 0y = 0z = 0th = 0if (key == '\x03'):breaktwist = Twist()twist.linear.x = x*speed; twist.linear.y = y*speed; twist.linear.z = z*speed;twist.angular.x = 0; twist.angular.y = 0; twist.angular.z = th*turnpub.publish(twist)except Exception as e:print(e)finally:twist = Twist()twist.linear.x = 0; twist.linear.y = 0; twist.linear.z = 0twist.angular.x = 0; twist.angular.y = 0; twist.angular.z = 0pub.publish(twist)termios.tcsetattr(sys.stdin, termios.TCSADRAIN, settings)

4. 总结

• 在ROS下进行控制时，首先启动键盘控制节点，然后订阅相应的话题即可。

• 以3为例：

1. 首先启动ROS Master：roscore

2. 运行该节点：rosrun teleop_twist_keyboard teleop_twist_keyboard_descartes.py
   

3. 查看话题列表：rostopic list
   

4. 查看话题内容：rostopic echo cmd_vel
   

5. 查看/cmd_vel话题的消息类型：rostopic type cmd_vel
   

6. 订阅/cmd_vel话题后根据消息文件接收数据即可

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1. http://www.guyuehome.com/253 ↩︎ ↩︎

2. https://github.com/ncnynl/teleop_twist_keyboard ↩︎