ROS launchの自動起動について

ロボットが立ち上がった際、自動的にコマンドの待ち受け状態に入り、launchファイルのロード、開始、停止、再開、アウトなどのコマンドを受け付けて、指定されたlaunchファイルを実行することが可能な仕組みを作る必要があった。

#!/usr/bin/env python
import roslaunch
import os
import rospy
class Ros_Launch(object):
    def __init__(self, ):
        self.launchfile = ""
        self.reinitialize()
    def __del__(self,):
        self.exit()
    def load_file(self, launch_file):
        if self.is_alive():
            raise RuntimeError("you need to stop before you load another launch file")
            return False  
        self.launchfile = os.path.abspath(os.path.expanduser(launch_file))
        self.launch.parent.config = roslaunch.config.load_config_default([self.launchfile], None)
        return True
    def start(self, ):
        local_machine = roslaunch.core.local_machine()
        for n in self.launch.parent.config.nodes:
            n.machine = local_machine
        self.launch.start()
    def is_alive(self, ):
        if self.launch.parent.pm is not None and self.launch.parent.pm.is_alive() and len(self.launch.parent.pm.get_active_names())>0:
            return True
        return False
    def current_file(self, ):
        return self.launchfile
    def reinitialize(self, ):
        self.launch = roslaunch.scriptapi.ROSLaunch()
    def resume(self, launch_file):
        self.launch.stop()
        self.reinitialize()
        self.load_file(launch_file)
    def stop(self, ):
        self.launch.stop()
        self.reinitialize()
        #self.load_file(self.launchfile)
    def exit(self, ):
        self.launch.stop()

以上