position_control.py

'''Position control for F651
 
  Copyright (C) 2018, CPS2018 Challenge by Team Halmstad. All rights reserved.
 
  BSD license:
  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions
  are met:
  1. Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.
  2. Redistributions in binary form must reproduce the above copyright
     notice, this list of conditions and the following disclaimer in the
     documentation and/or other materials provided with the distribution.
  3. Neither the name of the copyright holder nor the names of
     contributors to this software may be used to endorse or promote
     products derived from this software without specific prior written
     permission.
 
  THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS''
  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
  HOLDER OR THE CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY
  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
  GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 '''
#!/usr/bin/env python
from geometry_msgs.msg import PoseStamped, TwistStamped, Point
import rospy
import math
from std_msgs.msg import Float32, Bool, String
from VelocityController import VelocityController
import numpy as np

class position_control():
    def __init__(self):
        print 'Initialising position control'
        rospy.init_node('position_control', anonymous=True)
        rate = rospy.Rate(20)

        rospy.Subscriber('/position_control/set_mode', String, self.set_mode_callback)
        rospy.Subscriber('/position_control/set_position', PoseStamped, self.set_pose_callback)
        rospy.Subscriber('/position_control/set_velocity', PoseStamped, self.set_velocity_callback)

        rospy.Subscriber('/position_control/set_x_pid', Point, self.set_x_pid)
        rospy.Subscriber('/position_control/set_y_pid', Point, self.set_y_pid)
        rospy.Subscriber('/position_control/set_z_pid', Point, self.set_z_pid)

        # pos
        self._pose_pub = rospy.Publisher('mavros/setpoint_position/local', PoseStamped, queue_size=10)
        self._pose_msg = PoseStamped()
        self._vel_pose_msg = PoseStamped()
        self._pos_state = "posctr"
        # vel
        self._vel_pub = rospy.Publisher('mavros/setpoint_velocity/cmd_vel', TwistStamped, queue_size=10)
        self._vel_msg = TwistStamped()
        self._vel_state = "velctr"

        self.local_pose = PoseStamped()
        rospy.Subscriber('/mavros/local_position/pose', PoseStamped, self._local_pose_callback)
        self.local_velocity = TwistStamped()
        rospy.Subscriber('/mavros/local_position/velocity', TwistStamped, self._local_velocity_callback)
        self.dist = rospy.Publisher('/position_control/distance', Bool, queue_size=10)

        self.current_publisher = self._pose_pub
        self.current_message = self._pose_msg
        #self._pose_msg.pose.position.z = 3
        self.set_pose(self._pose_msg)
        self.des_vel = TwistStamped()
        self.current_mode = String()
        self.current_mode.data = 'posctr'

        self.vController = VelocityController()
        self.vController.set_x_pid(2.8, 0.913921, 0.0, 0.15)
        self.vController.set_y_pid(2.8, 0.913921, 0.0, 0.15)#2.1, 0.713921, 0.350178
        self.vController.set_z_pid(1.3, 2.4893, 0.102084, 0.1)

        print 'Init done'
        while not rospy.is_shutdown():
            if self.current_mode.data == 'posctr':
                self._pose_pub.publish(self._pose_msg)
            elif self.current_mode.data == 'velctr':
                self.vController.setTarget(self._vel_pose_msg.pose)
                self.des_vel = self.vController.update(self.local_pose)
                self._vel_pub.publish(self.des_vel)
            else:
                print "No such position mode"
            self.check_distance()
            rate.sleep()

    def set_mode_callback(self, data):
        self.current_mode = data

    def set_vel(self, vel):
        self._vel_msg.twist.linear.x = vel.twist.linear.x
        self._vel_msg.twist.linear.y = vel.twist.linear.y
        self._vel_msg.twist.linear.z = vel.twist.linear.z

    def set_pose(self, pose):
        self._pose_msg.pose.position.x = pose.pose.position.x
        self._pose_msg.pose.position.y = pose.pose.position.y
        self._pose_msg.pose.position.z = pose.pose.position.z

        self._pose_msg.pose.orientation.x = pose.pose.orientation.x
        self._pose_msg.pose.orientation.y = pose.pose.orientation.y
        self._pose_msg.pose.orientation.z = pose.pose.orientation.z
        self._pose_msg.pose.orientation.w = pose.pose.orientation.w

    def set_vel_pose(self, vel_pose):
        #print(vel_pose.pose)
        self._vel_pose_msg.pose.position.x = self.local_pose.pose.position.x + vel_pose.pose.position.x
        self._vel_pose_msg.pose.position.y = self.local_pose.pose.position.y + vel_pose.pose.position.y
        self._vel_pose_msg.pose.position.z = vel_pose.pose.position.z
        #print(self._vel_pose_msg.pose)
        self._vel_pose_msg.pose.orientation.x = vel_pose.pose.orientation.x
        self._vel_pose_msg.pose.orientation.y = vel_pose.pose.orientation.y
        self._vel_pose_msg.pose.orientation.z = vel_pose.pose.orientation.z
        self._vel_pose_msg.pose.orientation.w = vel_pose.pose.orientation.w

    def _local_pose_callback(self, data):
        self.local_pose = data

    def _local_velocity_callback(self, data):
        self.local_velocity = data

    def set_pose_callback(self, data):
        self.set_pose(data)

    def set_velocity_callback(self, data):
        self.set_vel_pose(data)

    def set_x_pid(self,data):
        self.vController.set_x_pid(data.x, data.y, data.z)

    def set_y_pid(self,data):
        self.vController.set_y_pid(data.x, data.y, data.z)

    def set_z_pid(self,data):
        self.vController.set_z_pid(data.x, data.y, data.z)

    def check_distance(self):
        if self.current_mode.data == 'posctr':
            booldist = self.is_at_position(self.local_pose.pose.position, self._pose_msg.pose.position, 0.5)
            boolvel = self.hover_velocity()
            self.dist.publish(booldist and boolvel)
        elif self.current_mode.data == 'velctr':
            vel_pose_tot = PoseStamped()
            vel_pose_tot.pose.position.x = self._vel_pose_msg.pose.position.x
            vel_pose_tot.pose.position.y = self._vel_pose_msg.pose.position.y
            vel_pose_tot.pose.position.z = self._vel_pose_msg.pose.position.z
            #print("target vel_pos: {}".format(vel_pose_tot))
            booldist = self.is_at_position(self.local_pose.pose.position, vel_pose_tot.pose.position, 0.2)
            boolvel = self.hover_velocity()
            self.dist.publish(booldist and boolvel)

    def is_at_position(self,p_current, p_desired, offset):
        des_pos = np.array((p_desired.x,
                            p_desired.y,
                            p_desired.z))
        cur_pos = np.array((p_current.x,
                            p_current.y,
                            p_current.z))
        distance = np.linalg.norm(des_pos - cur_pos)
        return distance < offset

    def hover_velocity(self):
        return self.local_velocity.twist.linear.x < 0.2 and self.local_velocity.twist.linear.y < 0.2 and self.local_velocity.twist.linear.z < 0.2

if __name__ == '__main__':
    try:

        position_control()

    except rospy.ROSInterruptException:
        pass