#!/usr/bin/python3.5
# -*- encoding: utf-8 -*-
"""
This file implements an ANKI Cozmo ROS driver.
It wraps up several functionality of the Cozmo SDK including
camera and motors. As some main ROS parts are not python3.5
compatible, the famous "transformations.py" is shipped next
to this node. Also the TransformBroadcaster is taken from
ROS tf ones.
Copyright {2016} {Takashi Ogura}
Copyright {2017} {Peter Rudolph}
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
"""
# system
import sys
import numpy as np
from copy import deepcopy
# cozmo SDK
import cozmo
from cozmo.util import radians
# ROS
import rospy
from transformations import quaternion_from_euler
from camera_info_manager import CameraInfoManager
# ROS msgs
from diagnostic_msgs.msg import DiagnosticArray, DiagnosticStatus, KeyValue
from tf2_msgs.msg import TFMessage
from nav_msgs.msg import Odometry
from geometry_msgs.msg import (
Twist,
TransformStamped
)
from std_msgs.msg import (
String,
Float64,
ColorRGBA,
)
from sensor_msgs.msg import (
Image,
CameraInfo,
BatteryState,
Imu,
JointState,
)
# reused as original is not Python3 compatible
class TransformBroadcaster(object):
"""
:class:`TransformBroadcaster` is a convenient way to send transformation updates on the ``"/tf"`` message topic.
"""
def __init__(self, queue_size=100):
self.pub_tf = rospy.Publisher("/tf", TFMessage, queue_size=queue_size)
def send_transform(self, translation, rotation, time, child, parent):
"""
:param translation: the translation of the transformation as a tuple (x, y, z)
:param rotation: the rotation of the transformation as a tuple (x, y, z, w)
:param time: the time of the transformation, as a rospy.Time()
:param child: child frame in tf, string
:param parent: parent frame in tf, string
Broadcast the transformation from tf frame child to parent on ROS topic ``"/tf"``.
"""
t = TransformStamped()
t.header.frame_id = parent
t.header.stamp = time
t.child_frame_id = child
t.transform.translation.x = translation[0]
t.transform.translation.y = translation[1]
t.transform.translation.z = translation[2]
t.transform.rotation.x = rotation[0]
t.transform.rotation.y = rotation[1]
t.transform.rotation.z = rotation[2]
t.transform.rotation.w = rotation[3]
self.send_transform_message(t)
def send_transform_message(self, transform):
"""
:param transform: geometry_msgs.msg.TransformStamped
Broadcast the transformation from tf frame child to parent on ROS topic ``"/tf"``.
"""
tfm = TFMessage([transform])
self.pub_tf.publish(tfm)
class CozmoRos(object):
"""
The Cozmo ROS driver object.
"""
def __init__(self, coz):
"""
:type coz: cozmo.Robot
:param coz: The cozmo SDK robot handle (object).
"""
# vars
self._cozmo = coz
self._lin_vel = .0
self._ang_vel = .0
self._cmd_lin_vel = .0
self._cmd_ang_vel = .0
self._last_pose = self._cozmo.pose
self._wheel_vel = (0, 0)
self._optical_frame_orientation = quaternion_from_euler(-np.pi/2., .0, -np.pi/2.)
self._camera_info_manager = CameraInfoManager('cozmo_camera', namespace='/cozmo_camera')
# tf
self._tfb = TransformBroadcaster()
# params
self._odom_frame = rospy.get_param('~odom_frame', 'odom')
self._footprint_frame = rospy.get_param('~footprint_frame', 'base_footprint')
self._base_frame = rospy.get_param('~base_frame', 'base_link')
self._head_frame = rospy.get_param('~head_frame', 'head_link')
self._camera_frame = rospy.get_param('~camera_frame', 'camera_link')
self._camera_optical_frame = rospy.get_param('~camera_optical_frame', 'cozmo_camera')
camera_info_url = rospy.get_param('~camera_info_url', '')
# pubs
self._joint_state_pub = rospy.Publisher('joint_states', JointState, queue_size=1)
self._odom_pub = rospy.Publisher('odom', Odometry, queue_size=1)
self._imu_pub = rospy.Publisher('imu', Imu, queue_size=1)
self._battery_pub = rospy.Publisher('battery', BatteryState, queue_size=1)
# Note: camera is published under global topic (preceding "/")
self._image_pub = rospy.Publisher('/cozmo_camera/image', Image, queue_size=10)
self._camera_info_pub = rospy.Publisher('/cozmo_camera/camera_info', CameraInfo, queue_size=10)
# subs
self._backpack_led_sub = rospy.Subscriber(
'backpack_led', ColorRGBA, self._set_backpack_led, queue_size=1)
self._twist_sub = rospy.Subscriber('cmd_vel', Twist, self._twist_callback, queue_size=1)
self._say_sub = rospy.Subscriber('say', String, self._say_callback, queue_size=1)
self._head_sub = rospy.Subscriber('head_angle', Float64, self._move_head, queue_size=1)
self._lift_sub = rospy.Subscriber('lift_height', Float64, self._move_lift, queue_size=1)
# diagnostics
self._diag_array = DiagnosticArray()
self._diag_array.header.frame_id = self._base_frame
diag_status = DiagnosticStatus()
diag_status.hardware_id = 'Cozmo Robot'
diag_status.name = 'Cozmo Status'
diag_status.values.append(KeyValue(key='Battery Voltage', value=''))
diag_status.values.append(KeyValue(key='Head Angle', value=''))
diag_status.values.append(KeyValue(key='Lift Height', value=''))
self._diag_array.status.append(diag_status)
self._diag_pub = rospy.Publisher('/diagnostics', DiagnosticArray, queue_size=1)
# camera info manager
self._camera_info_manager.setURL(camera_info_url)
self._camera_info_manager.loadCameraInfo()
def _publish_diagnostics(self):
# alias
diag_status = self._diag_array.status[0]
# fill diagnostics array
battery_voltage = self._cozmo.battery_voltage
diag_status.values[0].value = '{:.2f} V'.format(battery_voltage)
diag_status.values[1].value = '{:.2f} deg'.format(self._cozmo.head_angle.degrees)
diag_status.values[2].value = '{:.2f} mm'.format(self._cozmo.lift_height.distance_mm)
if battery_voltage > 3.5:
diag_status.level = DiagnosticStatus.OK
diag_status.message = 'Everything OK!'
elif battery_voltage > 3.4:
diag_status.level = DiagnosticStatus.WARN
diag_status.message = 'Battery low! Go charge soon!'
else:
diag_status.level = DiagnosticStatus.ERROR
diag_status.message = 'Battery very low! Cozmo will power off soon!'
# update message stamp and publish
self._diag_array.header.stamp = rospy.Time.now()
self._diag_pub.publish(self._diag_array)
def _move_head(self, cmd):
"""
Move head to given angle.
:type cmd: Float64
:param cmd: The message containing angle in degrees. [-25 - 44.5]
"""
action = self._cozmo.set_head_angle(radians(cmd.data * np.pi / 180.), duration=0.1,
in_parallel=True)
action.wait_for_completed()
def _move_lift(self, cmd):
"""
Move lift to given height.
:type cmd: Float64
:param cmd: A value between [0 - 1], the SDK auto
scales it to the according height.
"""
action = self._cozmo.set_lift_height(height=cmd.data,
duration=0.2, in_parallel=True)
action.wait_for_completed()
def _set_backpack_led(self, msg):
"""
Set the color of the backpack LEDs.
:type msg: ColorRGBA
:param msg: The color to be set.
"""
# setup color as integer values
color = [int(x * 255) for x in [msg.r, msg.g, msg.b, msg.a]]
# create lights object with duration
light = cozmo.lights.Light(cozmo.lights.Color(rgba=color), on_period_ms=1000)
# set lights
self._cozmo.set_all_backpack_lights(light)
def _twist_callback(self, cmd):
"""
Set commanded velocities from Twist message.
The commands are actually send/set during run loop, so delay
is in worst case up to 1 / update_rate seconds.
:type cmd: Twist
:param cmd: The commanded velocities.
"""
# compute differential wheel speed
axle_length = 0.07 # 7cm
self._cmd_lin_vel = cmd.linear.x
self._cmd_ang_vel = cmd.angular.z
rv = self._cmd_lin_vel + (self._cmd_ang_vel * axle_length * 0.5)
lv = self._cmd_lin_vel - (self._cmd_ang_vel * axle_length * 0.5)
self._wheel_vel = (lv*1000., rv*1000.) # convert to mm / s
def _say_callback(self, msg):
"""
The callback for incoming text messages to be said.
:type msg: String
:param msg: The text message to say.
"""
self._cozmo.say_text(msg.data).wait_for_completed()
def _publish_objects(self):
"""
Publish detected object as transforms between odom_frame and object_frame.
"""
for obj in self._cozmo.world.visible_objects:
now = rospy.Time.now()
x = obj.pose.position.x * 0.001
y = obj.pose.position.y * 0.001
z = obj.pose.position.z * 0.001
q = (obj.pose.rotation.q1, obj.pose.rotation.q2, obj.pose.rotation.q3, obj.pose.rotation.q0)
self._tfb.send_transform(
(x, y, z), q, now, 'cube_' + str(obj.object_id), self._odom_frame
)
def _publish_image(self):
"""
Publish latest camera image as Image with CameraInfo.
"""
# only publish if we have a subscriber
if self._image_pub.get_num_connections() == 0:
return
# get latest image from cozmo's camera
camera_image = self._cozmo.world.latest_image
if camera_image is not None:
# convert image to gray scale as it is gray although
img = camera_image.raw_image.convert('L')
ros_img = Image()
ros_img.encoding = 'mono8'
ros_img.width = img.size[0]
ros_img.height = img.size[1]
ros_img.step = ros_img.width
ros_img.data = img.tobytes()
ros_img.header.frame_id = 'cozmo_camera'
cozmo_time = camera_image.image_recv_time
ros_img.header.stamp = rospy.Time.from_sec(cozmo_time)
# publish images and camera info
self._image_pub.publish(ros_img)
camera_info = self._camera_info_manager.getCameraInfo()
camera_info.header = ros_img.header
self._camera_info_pub.publish(camera_info)
def _publish_joint_state(self):
"""
Publish joint states as JointStates.
"""
# only publish if we have a subscriber
if self._joint_state_pub.get_num_connections() == 0:
return
js = JointState()
js.header.stamp = rospy.Time.now()
js.header.frame_id = 'cozmo'
js.name = ['head', 'lift']
js.position = [self._cozmo.head_angle.radians,
self._cozmo.lift_height.distance_mm * 0.001]
js.velocity = [0.0, 0.0]
js.effort = [0.0, 0.0]
self._joint_state_pub.publish(js)
def _publish_imu(self):
"""
Publish inertia data as Imu message.
"""
# only publish if we have a subscriber
if self._imu_pub.get_num_connections() == 0:
return
imu = Imu()
imu.header.stamp = rospy.Time.now()
imu.header.frame_id = self._base_frame
imu.orientation.w = self._cozmo.pose.rotation.q0
imu.orientation.x = self._cozmo.pose.rotation.q1
imu.orientation.y = self._cozmo.pose.rotation.q2
imu.orientation.z = self._cozmo.pose.rotation.q3
imu.angular_velocity.x = self._cozmo.gyro.x
imu.angular_velocity.y = self._cozmo.gyro.y
imu.angular_velocity.z = self._cozmo.gyro.z
imu.linear_acceleration.x = self._cozmo.accelerometer.x * 0.001
imu.linear_acceleration.y = self._cozmo.accelerometer.y * 0.001
imu.linear_acceleration.z = self._cozmo.accelerometer.z * 0.001
self._imu_pub.publish(imu)
def _publish_battery(self):
"""
Publish battery as BatteryState message.
"""
# only publish if we have a subscriber
if self._battery_pub.get_num_connections() == 0:
return
battery = BatteryState()
battery.header.stamp = rospy.Time.now()
battery.voltage = self._cozmo.battery_voltage
battery.present = True
if self._cozmo.is_on_charger: # is_charging always return False
battery.power_supply_status = BatteryState.POWER_SUPPLY_STATUS_CHARGING
else:
battery.power_supply_status = BatteryState.POWER_SUPPLY_STATUS_NOT_CHARGING
self._battery_pub.publish(battery)
def _publish_odometry(self):
"""
Publish current pose as Odometry message.
"""
# only publish if we have a subscriber
if self._odom_pub.get_num_connections() == 0:
return
now = rospy.Time.now()
odom = Odometry()
odom.header.frame_id = self._odom_frame
odom.header.stamp = now
odom.child_frame_id = self._footprint_frame
odom.pose.pose.position.x = self._cozmo.pose.position.x * 0.001
odom.pose.pose.position.y = self._cozmo.pose.position.y * 0.001
odom.pose.pose.position.z = self._cozmo.pose.position.z * 0.001
q = quaternion_from_euler(.0, .0, self._cozmo.pose_angle.radians)
odom.pose.pose.orientation.x = q[0]
odom.pose.pose.orientation.y = q[1]
odom.pose.pose.orientation.z = q[2]
odom.pose.pose.orientation.w = q[3]
odom.pose.covariance = np.diag([1e-2, 1e-2, 1e-2, 1e3, 1e3, 1e-1]).ravel()
odom.twist.twist.linear.x = self._lin_vel
odom.twist.twist.angular.z = self._ang_vel
odom.twist.covariance = np.diag([1e-2, 1e3, 1e3, 1e3, 1e3, 1e-2]).ravel()
self._odom_pub.publish(odom)
def _publish_tf(self, update_rate):
"""
Broadcast current transformations and update
measured velocities for odometry twist.
Published transforms:
odom_frame -> footprint_frame
footprint_frame -> base_frame
base_frame -> head_frame
head_frame -> camera_frame
camera_frame -> camera_optical_frame
"""
now = rospy.Time.now()
x = self._cozmo.pose.position.x * 0.001
y = self._cozmo.pose.position.y * 0.001
z = self._cozmo.pose.position.z * 0.001
# compute current linear and angular velocity from pose change
# Note: Sign for linear velocity is taken from commanded velocities!
# Note: The angular velocity can also be taken from gyroscopes!
delta_pose = self._last_pose - self._cozmo.pose
dist = np.sqrt(delta_pose.position.x**2
+ delta_pose.position.y**2
+ delta_pose.position.z**2) / 1000.0
self._lin_vel = dist * update_rate * np.sign(self._cmd_lin_vel)
self._ang_vel = -delta_pose.rotation.angle_z.radians * update_rate
# publish odom_frame -> footprint_frame
q = quaternion_from_euler(.0, .0, self._cozmo.pose_angle.radians)
self._tfb.send_transform(
(x, y, 0.0), q, now, self._footprint_frame, self._odom_frame)
# publish footprint_frame -> base_frame
q = quaternion_from_euler(.0, -self._cozmo.pose_pitch.radians, .0)
self._tfb.send_transform(
(0.0, 0.0, 0.02), q, now, self._base_frame, self._footprint_frame)
# publish base_frame -> head_frame
q = quaternion_from_euler(.0, -self._cozmo.head_angle.radians, .0)
self._tfb.send_transform(
(0.02, 0.0, 0.05), q, now, self._head_frame, self._base_frame)
# publish head_frame -> camera_frame
self._tfb.send_transform(
(0.025, 0.0, -0.015), (0.0, 0.0, 0.0, 1.0), now, self._camera_frame, self._head_frame)
# publish camera_frame -> camera_optical_frame
q = self._optical_frame_orientation
self._tfb.send_transform(
(0.0, 0.0, 0.0), q, now, self._camera_optical_frame, self._camera_frame)
# store last pose
self._last_pose = deepcopy(self._cozmo.pose)
def run(self, update_rate=10):
"""
Publish data continuously with given rate.
:type update_rate: int
:param update_rate: The update rate.
"""
r = rospy.Rate(update_rate)
while not rospy.is_shutdown():
self._publish_tf(update_rate)
self._publish_image()
self._publish_objects()
self._publish_joint_state()
self._publish_imu()
self._publish_battery()
self._publish_odometry()
self._publish_diagnostics()
# send message repeatedly to avoid idle mode.
# This might cause low battery soon
# TODO improve this!
self._cozmo.drive_wheels(*self._wheel_vel)
# sleep
r.sleep()
# stop events on cozmo
self._cozmo.stop_all_motors()
def cozmo_app(coz_conn):
"""
The main function of the cozmo ROS driver.
This function is called by cozmo SDK!
Use "cozmo.connect(cozmo_app)" to run.
:type coz_conn: cozmo.Connection
:param coz_conn: The connection handle to cozmo robot.
"""
coz = coz_conn.wait_for_robot()
coz.camera.image_stream_enabled = True
coz_ros = CozmoRos(coz)
coz_ros.run()
if __name__ == '__main__':
rospy.init_node('cozmo_driver')
cozmo.setup_basic_logging()
try:
cozmo.connect(cozmo_app)
except cozmo.ConnectionError as e:
sys.exit('A connection error occurred: {}'.format(e))
