def __init__(self):
# Give the node a name
rospy.init_node('out_and_back', anonymous=False)
# Set rospy to execute a shutdown function when exiting
rospy.on_shutdown(self.shutdown)
# Publisher to control the robot's speed
self.cmd_vel = rospy.Publisher('/cmd_vel', Twist, queue_size=5)
# How fast will we update the robot's movement?
rate = 20
# Set the equivalent ROS rate variable
r = rospy.Rate(rate)
# Set the forward linear speed to 0.2 meters per second
linear_speed = 0.2
# Set the travel distance in meters
goal_distance = 1.0
# Set the rotation speed in radians per second
angular_speed = 1.0
# Set the angular tolerance in degrees converted to radians
angular_tolerance = radians(2.5)
# Set the rotation angle to Pi radians (180 degrees)
goal_angle = pi
# Initialize the tf listener
self.tf_listener = tf.TransformListener()
# Give tf some time to fill its buffer
rospy.sleep(2)
# Set the odom frame
self.odom_frame = '/odom'
# Find out if the robot uses /base_link or /base_footprint
try:
self.tf_listener.waitForTransform(self.odom_frame, '/base_footprint', rospy.Time(), rospy.Duration(1.0))
self.base_frame = '/base_footprint'
except (tf.Exception, tf.ConnectivityException, tf.LookupException):
try:
self.tf_listener.waitForTransform(self.odom_frame, '/base_link', rospy.Time(), rospy.Duration(1.0))
self.base_frame = '/base_link'
except (tf.Exception, tf.ConnectivityException, tf.LookupException):
rospy.loginfo("Cannot find transform between /odom and /base_link or /base_footprint")
rospy.signal_shutdown("tf Exception")
# Initialize the position variable as a Point type
position = Point()
# Loop once for each leg of the trip
for i in range(2):
# Initialize the movement command
move_cmd = Twist()
# Set the movement command to forward motion
move_cmd.linear.x = linear_speed
# Get the starting position values
(position, rotation) = self.get_odom()
x_start = position.x
y_start = position.y
# Keep track of the distance traveled
distance = 0
# Enter the loop to move along a side
while distance < goal_distance and not rospy.is_shutdown():
# Publish the Twist message and sleep 1 cycle
self.cmd_vel.publish(move_cmd)
r.sleep()
# Get the current position
(position, rotation) = self.get_odom()
# Compute the Euclidean distance from the start
distance = sqrt(pow((position.x - x_start), 2) +
pow((position.y - y_start), 2))
# Stop the robot before the rotation
move_cmd = Twist()
self.cmd_vel.publish(move_cmd)
rospy.sleep(1)
# Set the movement command to a rotation
move_cmd.angular.z = angular_speed
# Track the last angle measured
last_angle = rotation
# Track how far we have turned
turn_angle = 0
while abs(turn_angle + angular_tolerance) < abs(goal_angle) and not rospy.is_shutdown():
# Publish the Twist message and sleep 1 cycle
self.cmd_vel.publish(move_cmd)
r.sleep()
# Get the current rotation
(position, rotation) = self.get_odom()
# Compute the amount of rotation since the last loop
delta_angle = normalize_angle(rotation - last_angle)
# Add to the running total
turn_angle += delta_angle
last_angle = rotation
# Stop the robot before the next leg
move_cmd = Twist()
self.cmd_vel.publish(move_cmd)
rospy.sleep(1)
# Stop the robot for good
self.cmd_vel.publish(Twist())
def __init__(self):
# Give the node a name
rospy.init_node('nav_square', anonymous=False)
# Set rospy to execute a shutdown function when terminating the script
rospy.on_shutdown(self.shutdown)
# How fast will we check the odometry values?
rate = 20
# Set the equivalent ROS rate variable
r = rospy.Rate(rate)
# Set the parameters for the target square
goal_distance = rospy.get_param("~goal_distance", 1.0) # meters
goal_angle = rospy.get_param("~goal_angle", radians(90)) # degrees converted to radians
linear_speed = rospy.get_param("~linear_speed", 0.2) # meters per second
angular_speed = rospy.get_param("~angular_speed", 0.7) # radians per second
angular_tolerance = rospy.get_param("~angular_tolerance", radians(2)) # degrees to radians
# Publisher to control the robot's speed
self.cmd_vel = rospy.Publisher('/cmd_vel', Twist, queue_size=5)
# The base frame is base_footprint for the TurtleBot but base_link for Pi Robot
self.base_frame = rospy.get_param('~base_frame', '/base_link')
# The odom frame is usually just /odom
self.odom_frame = rospy.get_param('~odom_frame', '/odom')
# Initialize the tf listener
self.tf_listener = tf.TransformListener()
# Give tf some time to fill its buffer
rospy.sleep(2)
# Set the odom frame
self.odom_frame = '/odom'
# Find out if the robot uses /base_link or /base_footprint
try:
self.tf_listener.waitForTransform(self.odom_frame, '/base_footprint', rospy.Time(), rospy.Duration(1.0))
self.base_frame = '/base_footprint'
except (tf.Exception, tf.ConnectivityException, tf.LookupException):
try:
self.tf_listener.waitForTransform(self.odom_frame, '/base_link', rospy.Time(), rospy.Duration(1.0))
self.base_frame = '/base_link'
except (tf.Exception, tf.ConnectivityException, tf.LookupException):
rospy.loginfo("Cannot find transform between /odom and /base_link or /base_footprint")
rospy.signal_shutdown("tf Exception")
# Initialize the position variable as a Point type
position = Point()
# Cycle through the four sides of the square
for i in range(4):
# Initialize the movement command
move_cmd = Twist()
# Set the movement command to forward motion
move_cmd.linear.x = linear_speed
# Get the starting position values
(position, rotation) = self.get_odom()
x_start = position.x
y_start = position.y
# Keep track of the distance traveled
distance = 0
# Enter the loop to move along a side
while distance < goal_distance and not rospy.is_shutdown():
# Publish the Twist message and sleep 1 cycle
self.cmd_vel.publish(move_cmd)
r.sleep()
# Get the current position
(position, rotation) = self.get_odom()
# Compute the Euclidean distance from the start
distance = sqrt(pow((position.x - x_start), 2) +
pow((position.y - y_start), 2))
# Stop the robot before rotating
move_cmd = Twist()
self.cmd_vel.publish(move_cmd)
rospy.sleep(1.0)
# Set the movement command to a rotation
move_cmd.angular.z = angular_speed
# Track the last angle measured
last_angle = rotation
# Track how far we have turned
turn_angle = 0
# Begin the rotation
while abs(turn_angle + angular_tolerance) < abs(goal_angle) and not rospy.is_shutdown():
# Publish the Twist message and sleep 1 cycle
self.cmd_vel.publish(move_cmd)
r.sleep()
# Get the current rotation
(position, rotation) = self.get_odom()
# Compute the amount of rotation since the last lopp
delta_angle = normalize_angle(rotation - last_angle)
turn_angle += delta_angle
last_angle = rotation
move_cmd = Twist()
self.cmd_vel.publish(move_cmd)
rospy.sleep(1.0)
# Stop the robot when we are done
self.cmd_vel.publish(Twist())
def __init__(self):
# Give the node a name
rospy.init_node('calibrate_angular', anonymous=False)
# Set rospy to execute a shutdown function when terminating the script
rospy.on_shutdown(self.shutdown)
# How fast will we check the odometry values?
self.rate = 30
r = rospy.Rate(self.rate)
# The test angle is 360 degrees
self.test_angle = radians(rospy.get_param('~test_angle', 360.0))
self.speed = rospy.get_param('~speed', 0.7) # radians per second
self.tolerance = rospy.get_param('tolerance', radians(5)) # degrees converted to radians
self.odom_angular_scale_correction = rospy.get_param('~odom_angular_scale_correction', 1.0)
self.start_test = rospy.get_param('~start_test', True)
# Publisher to control the robot's speed
self.cmd_vel = rospy.Publisher('/cmd_vel', Twist, queue_size=5)
# Fire up the dynamic_reconfigure server
dyn_server = Server(CalibrateAngularConfig, self.dynamic_reconfigure_callback)
# Connect to the dynamic_reconfigure server
dyn_client = dynamic_reconfigure.client.Client("calibrate_angular", timeout=60)
# The base frame is base_footprint for the TurtleBot but base_link for Pi Robot
self.base_frame = rospy.get_param('~base_frame', '/base_link')
# The odom frame is usually just /odom
self.odom_frame = rospy.get_param('~odom_frame', '/odom')
# Initialize the tf listener
self.tf_listener = tf.TransformListener()
# Give tf some time to fill its buffer
rospy.sleep(2)
# Make sure we see the odom and base frames
self.tf_listener.waitForTransform(self.odom_frame, self.base_frame, rospy.Time(), rospy.Duration(60.0))
rospy.loginfo("Bring up rqt_reconfigure to control the test.")
reverse = 1
while not rospy.is_shutdown():
# Execute the rotation
if self.start_test:
# Get the current rotation angle from tf
self.odom_angle = self.get_odom_angle()
last_angle = self.odom_angle
turn_angle = 0
# Alternate directions between tests
reverse = -reverse
angular_speed = reverse * self.speed
while abs(turn_angle) < abs(self.test_angle):
if rospy.is_shutdown():
return
move_cmd = Twist()
move_cmd.angular.z = angular_speed
self.cmd_vel.publish(move_cmd)
r.sleep()
# Get the current rotation angle from tf
self.odom_angle = self.get_odom_angle()
# Compute how far we have gone since the last measurement
delta_angle = self.odom_angular_scale_correction * normalize_angle(self.odom_angle - last_angle)
# Add to our total angle so far
turn_angle += delta_angle
last_angle = self.odom_angle
# Stop the robot
self.cmd_vel.publish(Twist())
# Update the status flag
self.start_test = False
params = {'start_test': False}
dyn_client.update_configuration(params)
rospy.sleep(0.5)
# Stop the robot
self.cmd_vel.publish(Twist())
