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ROS机器人Diego制作15-机械臂控制之键盘控制

ROS机器人Diego制作15-机械臂控制之键盘控制

说明:

  • 介绍如何实现键盘控制舵机

键盘控制舵机

  • 特意写了一个通过键盘控制机械臂舵机的代码,来调试舵机,
  • 代码是基于teleop_twist_keyboard修改的。
  • 在arduino_node.py中已经声明了舵机读和写的ROS Service:
  # A service to position a PWM servo
        rospy.Service('~servo_write', ServoWrite, self.ServoWriteHandler)

        # A service to read the position of a PWM servo
        rospy.Service('~servo_read', ServoRead, self.ServoReadHandler)
  • arduino端的舵机驱动,我们只需要实现这两个ROS Service的client就可以控制舵机了
  • 具体原理请看代码中的注释代码如下:
#!/usr/bin/env python
import roslib; roslib.load_manifest('teleop_twist_keyboard')
import rospy

from geometry_msgs.msg import Twist
from ros_arduino_msgs.srv import *
from math import pi as PI
import sys, select, termios, tty

msg = """
Reading from the keyboard  and Publishing to Twist, Servo or sensor!
---------------------------
Moving around:
   u    i    o
   j    k    l

, : up (+z)
. : down (-z)
m : stop

----------------------------
Left arm servo control:控制机器人左臂,每次调整0.09弧度
+   1   2   3   4   5   6
-   q   w   e   r   t   y  
----------------------------
Right arm servo control:控制机器人右臂,每次调整0.09弧度
+   a   s   d   f   g   h
-   z   x   c   v   b   n 

p : init the servo 初始化舵机

CTRL-C to quit
"""

moveBindings = {
        'i':(1,0,0,0),
        'o':(1,0,0,1),
        'j':(-1,0,0,-1),
        'l':(-1,0,0,1),
        'u':(1,0,0,-1),
        'k':(-1,0,0,0),
        ',':(0,0,1,0),
        '.':(0,0,-1,0),
           }

#右臂舵机的控制数组,1表示增加0.09弧度,0表示减少0.09弧度
rightArmServo={
                '1':(0,1),
            '2':(1,1),
            '3':(2,1),
            '4':(3,1),
            '5':(4,1),
            '6':(5,1),
            'q':(0,0),
            'w':(1,0),
            'e':(2,0),
            'r':(3,0),
            't':(4,0),
            'y':(5,0),
          }

#左臂舵机的控制数组,1表示增加0.09弧度,0表示减少0.09弧度
leftArmServo={
            'a':(6,1),
            's':(7,1),
            'd':(8,1),
            'f':(9,1),
            'g':(10,1),
            'h':(11,1),
            'z':(6,0),
            'x':(7,0),
            'c':(8,0),
            'v':(9,0),
            'b':(10,0),
            'n':(11,0),
          }

#手臂臂舵机的控制命令数组         
armCmd={
    '[':(0,1),#左臂初始化
    ']':(1,1),#右臂初始化
       }

def getradians(angle):
    return PI*angle/180


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 key

#舵机当前位置读取,调用servo_read service
def servoRead(servoNum):
    rospy.wait_for_service('/arduino/servo_read')
    try:
        readServo=rospy.ServiceProxy('/arduino/servo_read',ServoRead)
        return readServo(servoNum)
        except rospy.ServiceException, e:
            print "Service call failed: %s"%e

#舵机位置写,根据舵机标号设置舵机的位置0~π,注意这里的value对应的是弧度        
def servoWrite(servoNum, value):
        rospy.wait_for_service('/arduino/servo_write')
    try:
        servo_write=rospy.ServiceProxy('/arduino/servo_write',ServoWrite)
        servo_write(servoNum,value)
        print servoNum
            print value
        except rospy.ServiceException, e:
            print "Service call failed: %s"%e

#初始化右臂舵机角度,要根据实际情况调整舵机角度     
def initRightArm():
    servoWrite(0,getradians(60)) 
    servoWrite(1,getradians(80))
    servoWrite(2,getradians(90))
    servoWrite(3,getradians(90))
    servoWrite(4,getradians(90))
    servoWrite(5,getradians(90))

#初始化左臂舵机角度,要根据实际情况调整舵机角度    
def initLeftArm():  
    servoWrite(6,getradians(90))
    servoWrite(7,getradians(90))
    servoWrite(8,getradians(90))
    servoWrite(9,getradians(90))
    servoWrite(10,getradians(90))
    servoWrite(11,getradians(90))    

def 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 = 0
    y = 0
    z = 0
    th = 0
    status = 0

    try:
        print msg
        print vels(speed,turn)
        while(1):
            key = getKey()
            print key
            if key in moveBindings.keys():
                x = moveBindings[key][0]
                y = moveBindings[key][1]
                z = moveBindings[key][2]
                th = moveBindings[key][3]
            elif key in leftArmServo.keys():#左臂舵机控制
                value=servoRead(leftArmServo[key][1]).value             
                if(leftArmServo[key][1]==0):
                    value=value-getradians(5)
                    if value<=0:
                       value=0
                else:
                    value=value+getradians(5)
                    if value>=PI:
                       value=PI
                servoWrite(leftArmServo[key][0], value)
            elif key in rightArmServo.keys():#右臂舵机控制
                value=servoRead(rightArmServo[key][1]).value                
                if(rightArmServo[key][1]==0):
                    value=value-getradians(5)
                    if value<=0:
                       value=0
                else:
                    value=value+getradians(5)
                    if value>=PI:
                       value=PI
                servoWrite(rightArmServo[key][0], value)
            elif key in armCmd.keys():#舵机初始化
                if(armCmd[key][0]==0):
                    initRightArm()
                elif(armCmd[key][0]==1):
                    initLeftArm()
            else:
                x = 0
                y = 0
                z = 0
                th = 0
                if (key == '\x03'):
                    break

            twist = 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*turn
            pub.publish(twist)

    except BaseException,e:
        print e

    finally:
        twist = Twist()
        twist.linear.x = 0; twist.linear.y = 0; twist.linear.z = 0
        twist.angular.x = 0; twist.angular.y = 0; twist.angular.z = 0
        pub.publish(twist)

            termios.tcsetattr(sys.stdin, termios.TCSADRAIN, settings)
  • 这里需要强调一下硬件的使用过程中,一定要保证供电的功率足够,否则的话会出现串口通信异常,机械臂乱动等现象,这都是电源供电不足的问题导致的。

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标签: ros机器人diego制作