How to start an application

There are different ways to start a pitasc program, which are explained in the following.

File reader

The first option is to use the pitasc_filereader. It reads the app file (.xml) and runs one of the applications inside the applications member in the file.

Note

See also Applications

The syntax:

$ pitasc_filereader [<options>] <package> <filename> [<appname>]

The <package> argument specifies the package_name where your application file is present.

The <filename> argument specifies the relative path/filename of the application file in the package.

The [<appname>] argument allows you to specify a list of application names that get executed. If no application name is given and multiple applications are present inside the applications member of the app file, pitasc aborts and a list of all applications inside the applications member is printed out. If only one application is inside the applications member, pitasc runs it even if the [<appname>] argument is left empty.

The [<options>] argument contains a list of options. The following options are available:

-c, --component-info:

Print in which component the logging happened.

-v, --verbose:

Print code location of logging statements.

-l, --log-level <loglevel>:

Specify which log levels should be printed to the terminal. Possible values: [debug, info, warn, error, fatal]. Loglevel “debug” implies verbose logging.

-t, --trigger-periodic

Uses Trigger with constant trigger rate instead of Joint Topic/ROS based Trigger.

-h, --help:

Print this usage information.

Example

$ pitasc_filereader pitasc_common examples/beginner/multiple_apps.xml another_application

Executor

The second option to start an application, is to run the pitasc_executor_rossrv with the following command.

$ pitasc_executor_rossrv [<options>]

The [<options>] argument specifies a list of options. The following options are available:

-c, --component-info:

Print in which component the logging happened.

-v, --verbose:

Print code location of logging statements.

-l, --log-level <loglevel>:

Specify which log levels should print to the terminal. Possible values: [debug, info, warn, error, fatal]. Loglevel “debug” implies verbose logging.

-t, --trigger-periodic

Uses Trigger with constant trigger rate instead of Joint Topic/ROS based Trigger.

-h, --help:

Print this usage information.

This command starts a ros node providing the following ros services:

/pitasc/load loads your application.xml file into the executor.
$ rosservice call /pitasc/load <package> <filename> [<parameters>]
The <package> argument specifies the package_name where your application file is present.

The <filename> argument specifies the relative path/filename of the application file in the package.

The [<parameters>] argument allows you to change parameters of skills/script/etc. inside the applications member of the app file (this is an optional). Parameters have a name and a value. You can specify the parameter of a nested sub-skill by chaining the names with a . connecting them. Use a -> in front of the value of value to indicate that the parameter referenced a parameter with the id of value. See example below at /pitasc/run

Console example
$ rosservice call /pitasc/load "package: 'pitasc_common' file_name: 'examples/beginner/multiple_apps.xml'"
Python example
import rospy from pitasc.srv import Load if __name__ == "__main__": rospy.init_node("load_srv_caller", anonymous=True) load_srv = rospy.ServiceProxy("/pitasc/load", Load) resp_load = load_srv.call(package="pitasc_common", file_name="examples/beginner/multiple_apps.xml")
/pitasc/list prints out a list of all available applications inside the applications member of the loaded app file.
$ rosservice call /pitasc/list

/pitasc/run starts an application from inside the applications member of your app file.

$ rosservice call /pitasc/run <app> [<parameters>]
The <app> argument allows you to specify the name of the applications to run. If no application name is specified and multiple applications are inside the applications member of the app file pitasc aborts and a list of all applications inside the applications member is printed out. If only one application is inside the applications member, pitasc runs it even if the <app> argument is left empty.

The [<parameters>] argument allows you to change parameters of skills/script/etc. inside the applications member of the app file. Parameters have a name and a value. You can specify the parameter of a nested sub-skill by chaining the names with a . connecting them. Use a -> in front of the value of value to indicate that the parameter referenced a parameter with the id of value.

Console example
$ rosservice call /pitasc/run "app: 'another_application'
parameters:
- name: 'skills.move_to.max_linear_velocity'
value: '0.1'
- name: 'skills.move_to.target_frame'
value: 'target2'
- name: 'skills.approach.target_frame'
value: '->move_to.target_frame'"
Python example
import rospy

from pitasc.srv import Run
from pitasc.msg import Parameter

if __name__ == "__main__":
    rospy.init_node("run_srv_caller", anonymous=True)

    run_srv = rospy.ServiceProxy("/pitasc/run", Run)

    param1 = Parameter(
        name="skills.move_to.max_linear_velocity",
        value="0.1",
    )
    param2 = Parameter(
        name="skills.move_to.target_frame",
        value="target2",
    )
    param3 = Parameter(
        name="skills.approach.target_frame",
        value="->move_to.target_frame",
    )
    # requires pitasc_common/examples/beginner/multiple_apps.xml being loaded beforehand
    resp = run_srv(app="another_application", parameters=[param1, param2, param3])

/pitasc/stop stops a running application.
$ rosservice call /pitasc/stop
/pitasc/pause pauses a running application.
$ rosservice call /pitasc/pause
/pitasc/resume resumes a paused application.
$ rosservice call /pitasc/resume

Pi Teacher (GUI)

Instead of using rosservice calls directly, another option is to use the pi_teacher along with the executor node, which gives you a graphical user interface for calling the ros services.

$ rqt -s pi_teacher

Python API

You can also use the python API to use pitasc directly within python. Please note that this feature is still experimental.

import os
import sys

import rospy

# pitasc
from pitasc.model import Model
from cppitasc.runtime import Executor, roscpp_init
from cppitasc.package_path import get_package_path

if __name__ == "__main__":

    # ROS
    rospy.init_node("pitasc", log_level=rospy.INFO)

    # init pitasc
    roscpp_init("pitasc", sys.argv)

    # Load file
    model = Model()
    file_name = os.path.join(get_package_path("pitasc_common"), "examples/beginner/multiple_apps.xml")
    model.import_file(file_name)

    # Execute
    executor = Executor(model)

    executor.run("another_application", {})