Services Back to services

SERVICE - /user_target

Provided by:

reach_user_pos_service.py

Used by:

user_console.py

Semantic

This service lets the program to reach, using move_base, a point of the environment. It is used for letting the user to manually give a target to reach to teh robot.

The server itself performs no checkings on the given target: it must be the node user_console.py the one which checks if the position is defined or not.

See also: check_position

Service code

SRV file

# service file name 'user_target'
 
# target
geometry_msgs/Point target
 
---
 
# success?
bool success

Set-up (Python)

from final_assignment.srv import user_target, user_targetRequest, user_targetResponse
 
# name of the service 'user_target'
name_user_target = "/user_target"
 
## === CLIENT SIDE ===
 
# entry point of the service 'user_target'
srv_user_target = None
 
# require the server 'user_target'
rospy.loginfo( " [%s] getting service %s ...", node_name, name_user_target )
rospy.wait_for_service( name_user_target )
srv_user_target = rospy.ServiceProxy( name_user_target, user_target )
rospy.loginfo( " [%s] service %s ... OK", node_name, name_user_target )
 
## === SERVER SIDE ===
 
# SERVER
# require the server 'user_target'
rospy.loginfo( " [%s] advertising service %s ...", node_name, name_user_target )
rospy.Service( name_user_target, user_target, srv_user_target )
rospy.loginfo( " [%s] service %s ... OK", node_name, name_user_target )

How to use the service (Python)

The request always succeed.

BLOCKING REQUEST: the caller has to wait until the robot has reached the target position.

global name_user_target, srv_user_target
 
req = user_targetRequest(  )
# req.target = Point(x,y,z)
 
# BLOCKING SERVICE!
# wait until the robot has reached the target
res = srv_user_target( req )