ROS（Linux）与非ROS（Windows）计算机之间的通信

Question

我有一台运行在Linux下的使用Python的ROS计算机，我试图从一台也使用Python的Windows计算机向它发送数据。我已经成功地使用TCP套接字将数据从Windows传输到Linux，但是只要我将脚本实现为ROS脚本，ROS脚本就会在尝试从套接字接收数据时崩溃，特别是在socketName.recvfrom(bufferSize)处。

在线调查，我发现这是预期的行为。 ROS使用TCP进行通信，并故意难以为此实现一个单独的套接字（如果我已正确理解它）。

有没有办法解决这个问题？实现从非ROS计算机读取数据的ROS脚本的最有效方法是什么？

Answer 1

我发现这个节点，我最近使用的是使用NMEA地理定位协议发送数据的Windows TCP/IP套接字。

它使用线程在TCP/IP连接中进行连接，然后进行解码消息并将其转换为ros格式的过程。

PS：你可以发布你的脚本来尽力帮助你吗？

#!/usr/bin/env python 
import roslib; roslib.load_manifest('collision_avoidance') 
import rospy 
from collision_avoidance.msg import vipos 

from socket import * 
import thread 
import time 
import multiprocessing 
from multiprocessing import Process 
from multiprocessing import Queue 

def checkcrc(msgSplitted): 
checksum = msgSplitted[0] 
    for i in range (1,len(msgSplitted)-3): 
    checksum = chr(ord(checksum)^ord(msgSplitted[i])) 
print int(msgSplitted[-2:],16) 
print ord(checksum) 
    if (ord(checksum) == int(msgSplitted[-2:],16)): 
    print "true" 
    return True 
else: 
    print "(!)- Checksum failed" 
    return False 

#client handler thread 
fullMessageRead="" 
def parseNmeaMessages(msgToParse,q): 
    """ parse the nmea messages expected 
    """ 
    print "will parse following message",msgToParse 
    if msgToParse.find("VIPOS") == -1 : 
       return 
if checkcrc(msgToParse): 
      msgSplitted = msgToParse.replace("*",",").replace("\t","").replace("$","") 
     print msgSplitted   
       msgSplitted = msgSplitted.split(",") 
       if len(msgSplitted) > 1: 
         keyWord = msgSplitted[0] 
         if keyWord =="VIPOS" : 
           if len(msgSplitted) >= 9 : 
        print msgSplitted 
             Timestamp_trans = msgSplitted[1] 
             trans_x_value = msgSplitted[2] 
        trans_y_value = msgSplitted[3] 
        trans_z_value = msgSplitted[4] 
        Timestamp_rot = msgSplitted[5] 
        rot_x_value = msgSplitted[6] 
        rot_y_value = msgSplitted[7] 
        rot_z_value = msgSplitted[8] 

             try : 
              TRAT = float(Timestamp_trans) 
          TRAx = float(trans_x_value) 
          TRAy = float(trans_y_value) 
          TRAz = float(trans_z_value) 
          ROTT = float(Timestamp_rot) 
          ROTx = float(rot_x_value) 
          ROTy = float(rot_y_value) 
          ROTz = float(rot_z_value) 
                q.put([TRAT,TRAx,TRAy,TRAz,ROTT,ROTx,ROTy,ROTz]) 
             except Exception,msg: 
                print "(!)- cannot convert to float" 

             #do stuff 
         else: 
           pass 
       else: 
         print "(!)- bad message :",msgToParse 
       pass 

def getNmeaMessage(msgRead,q): 
    """ get an nmea message expected like $keywor,value,value*crc\r\n" 
    """ 
    global fullMessageRead 
    fullMessageRead += msgRead 
    startOfFrame =-1 
    endOfFrame =-1 

    endOfFrame= fullMessageRead.find("\n") 
    while endOfFrame != -1: 
       startOfFrame = fullMessageRead.find("$") 
       if (startOfFrame!= -1) and (endOfFrame != -1): 
         if startOfFrame > endOfFrame: 
           #error in trame read 
           fullMessageRead = fullMessageRead[startOfFrame:len(fullMessageRead)] 
         else: 
           #get string we need 
           msgToParse = fullMessageRead[startOfFrame:endOfFrame] 
           try: 
             fullMessageRead = fullMessageRead[endOfFrame+1:len(fullMessageRead)] 
           except: 
             fullMessageRead ="" 
           parseNmeaMessages(msgToParse,q) 
       endOfFrame= fullMessageRead.find("\n") 

def handler(clientsock,addr,q,BUFSIZ): 
    data= "1" 
    timestamp = time.time() 
    while data != "" : 
       data = clientsock.recv(BUFSIZ) 
       getNmeaMessage(data,q) 

       timestamp = time.time() 
    #clientsock.close() 


class DecoderProcess(Process): 
    def __init__(self,q): 
       super(DecoderProcess, self).__init__() 
       self.HOST = '' 
       self.PORT = 4321 
       self.BUFSIZ = 1024 
       self.ADDR = (self.HOST, self.PORT) 
       self.q =q 


    def run(self): 
       self.serversock = socket(AF_INET, SOCK_STREAM) 
       self.serversock.bind(self.ADDR) 
       self.serversock.listen(2) 


       while not rospy.is_shutdown(): 
         print 'waiting for connection...' 
         clientsock, addr = self.serversock.accept() 
         print '...connected from:', addr 
         thread.start_new_thread(handler, (clientsock, addr,self.q,self.BUFSIZ)) 


if __name__=='__main__': 

    rospy.init_node('Vicon_Ros') 
    pub = rospy.Publisher('vicon', vipos) 
r = rospy.Rate(20) # 10hz 

    q=Queue() 
    decoderProcess = DecoderProcess(q) 
    decoderProcess.start() 
    print "waiting from main thread" 
    while not rospy.is_shutdown(): 
     #data = "$VIPOS,092751,136,6259,630.33,61.32,0.06,31.66,280511*4B" 
     #parseNmeaMessages(data,q) 
       if not q.empty(): 
         dataRead= q.get() 

      message = vipos() 
      message.Timestamp_translation = float(dataRead[0]) 
      message.translation_x = float(dataRead[1]) 
      message.translation_y = float(dataRead[2]) 
      message.translation_z = float(dataRead[3]) 
      message.Timestamp_rotation = float(dataRead[4]) 
      message.rotation_x = float(dataRead[5]) 
      message.rotation_y = float(dataRead[6]) 
      message.rotation_z = float(dataRead[7]) 
      pub.publish(message) 
      r.sleep() 

    decoderProcess.stop() 

它可能是一个长文件，但它可能会给你一个工作模板。希望能帮助到你 ！