joystick_relay.py
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00001 #! /usr/bin/python
00002 # -*- coding: utf-8 -*-
00003 #
00004 # twist_mux: joystick_relay.py
00005 #
00006 # Copyright (c) 2013 PAL Robotics SL. All Rights Reserved
00007 #
00008 # Authors:
00009 #   * Enrique Fernandez
00010 #   * Siegfried-A. Gevatter
00011 
00012 import rospy
00013 import actionlib
00014 from twist_mux_msgs.msg import JoyPriorityAction, JoyTurboAction
00015 from geometry_msgs.msg import Twist
00016 from std_msgs.msg import Bool
00017 from visualization_msgs.msg import Marker
00018 
00019 import numpy as np
00020 
00021 class Velocity(object):
00022 
00023     def __init__(self, min_velocity, max_velocity, num_steps):
00024         assert min_velocity > 0 and max_velocity > 0 and num_steps > 0
00025         self._min = min_velocity
00026         self._max = max_velocity
00027         self._num_steps = num_steps
00028         if self._num_steps > 1:
00029             self._step_incr = (max_velocity - min_velocity) / (self._num_steps - 1)
00030         else:
00031             # If num_steps is one, we always use the minimum velocity.
00032             self._step_incr = 0
00033 
00034     def __call__(self, value, step=1):
00035         """
00036         Takes a value in the range [0, 1] and the step and returns the
00037         velocity (usually m/s or rad/s).
00038         """
00039         assert step > 0 and step <= self._num_steps
00040         max_value = self._min + self._step_incr * (step - 1)
00041         return value * max_value
00042 
00043 class ServiceLikeActionServer(object):
00044 
00045     def __init__(self, action_name, action_type, callback):
00046         self._action_type = action_type
00047         self._callback = callback
00048         self._server = actionlib.SimpleActionServer(action_name, action_type,
00049                                                     self._cb, False)
00050         self._server.start()
00051 
00052     def _cb(self, goal):
00053         self._callback()
00054         result = self._action_type().action_result
00055         self._server.set_succeeded(result)
00056 
00057 class VelocityControl:
00058 
00059     def __init__(self):
00060         self._num_steps = rospy.get_param('~turbo/steps', 1)
00061 
00062         forward_min = rospy.get_param('~turbo/linear_forward_min', 1.0)
00063         forward_max = rospy.get_param('~turbo/linear_forward_max', 1.0)
00064         self._forward = Velocity(forward_min, forward_max, self._num_steps)
00065 
00066         backward_min = rospy.get_param('~turbo/linear_backward_min', forward_min)
00067         backward_max = rospy.get_param('~turbo/linear_backward_max', forward_max)
00068         self._backward = Velocity(backward_min, backward_max, self._num_steps)
00069 
00070         lateral_min = rospy.get_param('~turbo/linear_lateral_min', 1.0)
00071         lateral_max = rospy.get_param('~turbo/linear_lateral_max', 1.0)
00072         self._lateral = Velocity(lateral_min, lateral_max, self._num_steps)
00073 
00074         angular_min = rospy.get_param('~turbo/angular_min', 1.0)
00075         angular_max = rospy.get_param('~turbo/angular_max', 1.0)
00076         self._angular = Velocity(angular_min, angular_max, self._num_steps)
00077 
00078         default_init_step = np.floor((self._num_steps + 1)/2.0)
00079         init_step = rospy.get_param('~turbo/init_step', default_init_step)
00080         if init_step < 0 or init_step > self._num_steps:
00081             self._init_step = default_init_step
00082             rospy.logwarn('Initial step %d outside range [1, %d]!'
00083                     ' Falling back to default %d' %
00084                     (init_step, self._num_steps, default_init_step))
00085         else:
00086             self._init_step = init_step
00087         self.reset_turbo()
00088 
00089     def validate_twist(self, cmd):
00090         if cmd.linear.z or cmd.angular.x or cmd.angular.y:
00091             rospy.logerr("Joystick provided invalid values, only linear.x, linear.y and angular.z may be non-zero.")
00092             return False
00093         if abs(cmd.linear.x) > 1.0 or abs(cmd.linear.y) > 1.0 or abs(cmd.angular.z) > 1.0:
00094             rospy.logerr("Joystick provided invalid values (%d, %d, %d), not in [-1, 1] range." % (cmd.linear.x, cmd.linear.y, cmd.angular.z))
00095             return False
00096         return True
00097 
00098     def scale_twist(self, cmd):
00099         twist = Twist()
00100         if self.validate_twist(cmd):
00101             if cmd.linear.x >= 0:
00102                 twist.linear.x = self._forward(cmd.linear.x, self._current_step)
00103             else:
00104                 twist.linear.x = self._backward(cmd.linear.x, self._current_step)
00105             twist.linear.y = self._lateral(cmd.linear.y, self._current_step)
00106             twist.angular.z = self._angular(cmd.angular.z, self._current_angular_step)
00107         return twist
00108 
00109     def increase_turbo(self):
00110         if self._current_step < self._num_steps:
00111             self._current_step += 1
00112         self.increase_angular_turbo()
00113 
00114     def decrease_turbo(self):
00115         if self._current_step > 1:
00116             self._current_step -= 1
00117         self.decrease_angular_turbo()
00118 
00119     def increase_angular_turbo(self):
00120         if self._current_angular_step < self._num_steps:
00121             self._current_angular_step += 1
00122 
00123     def decrease_angular_turbo(self):
00124         if self._current_angular_step > 1:
00125             self._current_angular_step -= 1
00126 
00127     def reset_turbo(self):
00128         self._current_step = self._init_step
00129         self._current_angular_step = self._init_step
00130 
00131 class TextMarker(object):
00132 
00133     def __init__(self, scale = 1.0, z = 0.0):
00134         self._pub = rospy.Publisher('text_marker', Marker, latch=True)
00135 
00136         self._scale = scale
00137         self._z     = z
00138 
00139         # Build marker
00140         self._marker = Marker()
00141 
00142         self._marker.id = 0
00143         self._marker.type = Marker.TEXT_VIEW_FACING
00144 
00145         self._marker.header.frame_id = "base_footprint"
00146 
00147         self._marker.pose.position.z = self._z
00148 
00149         self._marker.pose.orientation.w = 1.0
00150 
00151         self._marker.scale.z = self._scale
00152 
00153         self._marker.color.a = 1.0
00154         self._marker.color.r = 1.0
00155         self._marker.color.g = 1.0
00156         self._marker.color.b = 1.0
00157 
00158     def update(self, joystick_priority, add = True):
00159         if add:
00160             self._marker.action  = Marker.ADD
00161 
00162             self._marker.text = "Manual" if joystick_priority else "Autonomous"
00163         else:
00164             self._marker.action  = Marker.DELETE
00165 
00166         self._pub.publish(self._marker)
00167 
00168 class JoystickRelay:
00169 
00170     def __init__(self):
00171         self._current_priority = rospy.get_param("~priority", True)
00172         self._velocity_control = VelocityControl()
00173 
00174         self._marker = TextMarker(0.5, 2.0)
00175 
00176         self._pub_cmd = rospy.Publisher('joy_vel_out', Twist)
00177         self._subscriber = rospy.Subscriber('joy_vel_in', Twist, self._forward_cmd, queue_size=1)
00178 
00179         self._pub_priority = rospy.Publisher('joy_priority', Bool, latch=True)
00180 
00181         # Wait for subscribers and publish initial joy_priority:
00182         self._pub_priority.publish(self._current_priority)
00183         self._marker.update(self._current_priority)
00184 
00185         # Marker timer (required to update the marker when the robot doesn't receive velocities):
00186         rospy.Timer(rospy.Duration(1.0), self._timer_callback)
00187 
00188         # Action servers to change priority & the currently active turbo step.
00189         # We aren't using services because they aren't supported by joy_teleop.
00190         self._server_priority = ServiceLikeActionServer('joy_priority_action', JoyPriorityAction,
00191                                                         self._toggle_priority)
00192         self._server_increase = ServiceLikeActionServer('joy_turbo_increase', JoyTurboAction,
00193                                                         self._velocity_control.increase_turbo)
00194         self._server_decrease = ServiceLikeActionServer('joy_turbo_decrease', JoyTurboAction,
00195                                                         self._velocity_control.decrease_turbo)
00196         self._server_angular_increase = ServiceLikeActionServer('joy_turbo_angular_increase', JoyTurboAction,
00197                                                                 self._velocity_control.increase_angular_turbo)
00198         self._server_angular_decrease = ServiceLikeActionServer('joy_turbo_angular_decrease', JoyTurboAction,
00199                                                                 self._velocity_control.decrease_angular_turbo)
00200         self._server_reset    = ServiceLikeActionServer('joy_turbo_reset', JoyTurboAction,
00201                                                         self._velocity_control.reset_turbo)
00202 
00203     def _forward_cmd(self, cmd):
00204         if self._current_priority:
00205             self._pub_cmd.publish(self._velocity_control.scale_twist(cmd))
00206 
00207         self._marker.update(self._current_priority)
00208 
00209     def _toggle_priority(self):
00210         self._current_priority = not self._current_priority
00211         rospy.loginfo("Toggled joy_priority, current status is: %s", self._current_priority)
00212         self._pub_priority.publish(self._current_priority)
00213         self._marker.update(self._current_priority)
00214 
00215         # Reset velocity to 0:
00216         if self._current_priority:
00217             self._pub_cmd.publish(Twist())
00218 
00219     def _timer_callback(self, event):
00220         self._marker.update(self._current_priority)
00221 
00222 if __name__ == '__main__':
00223     rospy.init_node('joystick_relay')
00224 
00225     server = JoystickRelay()
00226 
00227     rospy.spin()


twist_mux
Author(s): Enrique Fernandez , Siegfried-A. Gevatter Pujals
autogenerated on Fri Aug 28 2015 13:25:02