def __init__(self, default_port='/dev/ttyUSB0', default_update_rate=500.0):
"""
@param default_port: default tty port to use for establishing
connection to WheeledRobin. This will be overriden by ~port ROS
param if available.
"""
self.default_port = default_port
self.default_update_rate = default_update_rate
self.robot = WheeledRobin()
self.sensor_handler = None
self.sensor_state = WheeledRobinSensorState()
self.req_cmd_vel = None
rospy.init_node('wheeled_robin')
self._init_params()
self._init_pubsub()
self._pos2d = Pose2D() # 2D pose for odometry
self._diagnostics = WheeledRobinDiagnostics()
if self.has_gyro:
#from create_node.gyro import TurtlebotGyro
#self._gyro = TurtlebotGyro()
self._gyro = None
else:
self._gyro = None
dynamic_reconfigure.server.Server(WheeledRobinConfig, self.reconfigure)
def talker():
pub = rospy.Publisher('chatter', String)
rospy.init_node('talker')
robot = WheeledRobin()
#serial = SerialCommandInterface('/dev/ttyUSB0', 38400)
robot.start()
robot.control()
rospy.sleep(1.0)
robot.sci.control_params(80,15,100,50,5,30)
r = rospy.Rate(100)
while not rospy.is_shutdown():
#rospy.loginfo("Driving with -200 mm/s")
robot.drive(0, 0)
#rospy.loginfo(" ")
#robot.sci.sensors(1)
#a = robot.sci.ser.read(17)
#robot.sci.flush_input()
#rospy.sleep(0.5)
#robot.sci.sensors(22)
#b = robot.sci.ser.read(1)
# PacketID:0
#(e1,e2,e3,e4,e5,e6,e7,e8,e9,e10,e11,e12,e13,e14,e15,e16) = struct.unpack('>8h1B5h2B',a)
#printf('res: %r, %r, %r, %r, %r, %r, %r, %r, %r, %r, %r, %r, %r, %r, %r, %r\n',e1,e2,e3,e4,e5,e6,e7,e8,e9,e10,e11,e12,e13,e14,e15,e16)
# PacketID:1
#(e1,e2,e3,e4,e5,e6,e7,e8,e9) = struct.unpack('>8h1B',a)
#printf('res: %r, %r, %r, %r, %r, %r, %r, %r, %r\n',e1,e2,e3,e4,e5,e6,e7,e8,e9)
# PacketID:7-22
#(e2) = struct.unpack('>h',a)
#printf('res: %r\n', e2)
#rospy.loginfo(a)
r.sleep()
class WheeledRobin_Node(object):
_SENSOR_READ_RETRY_COUNT = 5
def __init__(self, default_port='/dev/ttyUSB0', default_update_rate=500.0):
"""
@param default_port: default tty port to use for establishing
connection to WheeledRobin. This will be overriden by ~port ROS
param if available.
"""
self.default_port = default_port
self.default_update_rate = default_update_rate
self.robot = WheeledRobin()
self.sensor_handler = None
self.sensor_state = WheeledRobinSensorState()
self.req_cmd_vel = None
rospy.init_node('wheeled_robin')
self._init_params()
self._init_pubsub()
self._pos2d = Pose2D() # 2D pose for odometry
self._diagnostics = WheeledRobinDiagnostics()
if self.has_gyro:
#from create_node.gyro import TurtlebotGyro
#self._gyro = TurtlebotGyro()
self._gyro = None
else:
self._gyro = None
dynamic_reconfigure.server.Server(WheeledRobinConfig, self.reconfigure)
def _init_params(self):
self.port = rospy.get_param('~port', self.default_port)
self.update_rate = rospy.get_param('~update_rate', self.default_update_rate)
self.drive_mode = rospy.get_param('~drive_mode', 'drive')
self.has_gyro = rospy.get_param('~has_gyro', False)
self.odom_angular_scale_correction = rospy.get_param('~odom_angular_scale_correction', 1.0)
self.odom_linear_scale_correction = rospy.get_param('~odom_linear_scale_correction', 1.0)
self.cmd_vel_timeout = rospy.Duration(rospy.get_param('~cmd_vel_timeout', 0.6))
self.stop_motors_on_bump = rospy.get_param('~stop_motors_on_bump', True)
self.min_abs_yaw_vel = rospy.get_param('~min_abs_yaw_vel', None)
self.max_abs_yaw_vel = rospy.get_param('~max_abs_yaw_vel', None)
self.publish_tf = rospy.get_param('~publish_tf', False)
self.odom_frame = rospy.get_param('~odom_frame', 'odom')
self.base_footprint_frame = rospy.get_param('~base_footprint_frame', 'base_footprint')
self.base_link_frame = rospy.get_param('~base_link_frame', 'base_link')
self.operate_mode = rospy.get_param('~operation_mode', 3)
rospy.loginfo("serial port: %s"%(self.port))
rospy.loginfo("update rate: %s"%(self.update_rate))
rospy.loginfo("drive mode: %s"%(self.drive_mode))
rospy.loginfo("has_gyro: %s"%(self.has_gyro))
def _init_pubsub(self):
self.joint_states_pub = rospy.Publisher('joint_states', JointState)
self.odom_pub = rospy.Publisher('odom', Odometry)
self.sensor_state_pub = rospy.Publisher('~sensor_state', WheeledRobinSensorState)
self.operating_mode_srv = rospy.Service('~set_operation_mode', SetWheeledRobinMode, self.set_operation_mode)
self.digital_output_srv = rospy.Service('~set_digital_outputs', SetDigitalOutputs, self.set_digital_outputs)
if self.drive_mode == 'direct_drive':
self.cmd_vel_sub = rospy.Subscriber('cmd_vel', Twist, self.cmd_vel)
self.drive_cmd = self.robot.direct_drive
elif self.drive_mode == 'drive':
self.cmd_vel_sub = rospy.Subscriber('cmd_vel', Twist, self.cmd_vel)
self.drive_cmd = self.robot.drive
else:
rospy.logerr("unknown drive mode :%s"%(self.drive_mode))
self.transform_broadcaster = None
if self.publish_tf:
self.transform_broadcaster = tf.TransformBroadcaster()
def reconfigure(self, config, level):
self.update_rate = config['update_rate']
self.drive_mode = config['drive_mode']
self.has_gyro = config['has_gyro']
if self.has_gyro:
self._gyro.reconfigure(config, level)
self.odom_angular_scale_correction = config['odom_angular_scale_correction']
self.odom_linear_scale_correction = config['odom_linear_scale_correction']
self.cmd_vel_timeout = rospy.Duration(config['cmd_vel_timeout'])
self.stop_motors_on_bump = config['stop_motors_on_bump']
self.min_abs_yaw_vel = config['min_abs_yaw_vel']
self.max_abs_yaw_vel = config['max_abs_yaw_vel']
return config
def start(self):
log_once = True
while not rospy.is_shutdown():
try:
self.robot.start(self.port)
break
except serial.serialutil.SerialException as ex:
msg = "Failed to open port %s. Please make sure the Wheeled_Robin cable is plugged into the computer. \n"%(self.port)
self._diagnostics.node_status(msg,"error")
if log_once:
log_once = False
rospy.logerr(msg)
else:
sys.stderr.write(msg)
time.sleep(1.0)
self.sensor_handler = WheeledRobinSensorHandler(self.robot);
self.robot.safe = True
self.robot.control()
# Startup readings from WheeledRobin can be incorrect, discard first values
s = WheeledRobinSensorState()
try:
self.sense(s)
except Exception:
# packet read can get interrupted, restart loop to
# check for exit conditions
pass
def spin(self):
# state
s = self.sensor_state
odom = Odometry(header=rospy.Header(frame_id=self.odom_frame), child_frame_id=self.base_footprint_frame)
js = JointState(name = ["left_wheel_joint", "right_wheel_joint"], position=[0,0], velocity=[0,0], effort=[0,0])
r = rospy.Rate(self.update_rate)
last_cmd_vel = 0, 0
last_cmd_vel_time = rospy.get_rostime()
last_js_time = rospy.Time(0)
# We set the retry count to 0 initially to make sure that only
# if we received at least one sensor package, we are robust
# agains a few sensor read failures. For some strange reason,
# sensor read failures can occur when switching to full mode
# on the Roomba.
sensor_read_retry_count = 0
while not rospy.is_shutdown():
last_time = s.header.stamp
curr_time = rospy.get_rostime()
# SENSE/COMPUTE STATE
try:
self.sense(s)
transformFootprintBase = self.compute_odom(s, last_time, odom)
# Future-date the joint states so that we don't have
# to publish as frequently.
js.header.stamp = curr_time + rospy.Duration(1)
except select.error:
# packet read can get interrupted, restart loop to
# check for exit conditions
continue
except DriverError:
if sensor_read_retry_count > 0:
rospy.logwarn('Failed to read sensor package. %d retries left.' % sensor_read_retry_count)
sensor_read_retry_count -= 1
continue
else:
raise
sensor_read_retry_count = self._SENSOR_READ_RETRY_COUNT
# PUBLISH STATE
self.sensor_state_pub.publish(s)
self.odom_pub.publish(odom)
if self.publish_tf:
self.publish_odometry_transform(odom)
self.transform_broadcaster.sendTransform(transformFootprintBase)
# publish future-dated joint state at 1Hz
if curr_time > last_js_time + rospy.Duration(1):
self.joint_states_pub.publish(js)
last_js_time = curr_time
self._diagnostics.publish(s, self._gyro)
#if self._gyro:
# self._gyro.publish(s, last_time)
# WRITE DESIRED VELOCITY
if self.req_cmd_vel is not None:
# check for velocity command and set the robot into full mode if necessary
if s.mode != self.operate_mode:
if self.operate_mode == 2:
self._robot_run_safe()
else:
self._robot_run_full()
# do some checks on the velocity : TODO
req_cmd_vel = self.req_cmd_vel
# Set to None so we know it's a new command
self.req_cmd_vel = None
# reset time for timeout
last_cmd_vel_time = last_time
else:
#zero commands on timeout
if last_time - last_cmd_vel_time > self.cmd_vel_timeout:
last_cmd_vel = 0,0
rospy.loginfo("A Timout in cmd_vel occured")
# do some checks on the velocity : TODO --> check bumpers
req_cmd_vel = last_cmd_vel
# send command
self.drive_cmd(*req_cmd_vel)
# record command
last_cmd_vel = req_cmd_vel
r.sleep()
def _robot_run_passive(self):
"""
Set WheeldRobin into passive run mode
"""
rospy.loginfo("Setting WheeldRobin to passive mode.")
#setting all the digital outputs to 0
self._set_digital_outputs([0, 0, 0, 0, 0, 0, 0, 0])
self.robot.passive()
def _robot_run_safe(self):
"""
Set WheeldRobin into safe run mode
"""
rospy.loginfo("Setting WheeldRobin to safe mode.")
self.robot.safe = True
self.robot.control()
b1 = (self.sensor_state.digital_inputs & 2)/2
b2 = (self.sensor_state.digital_inputs & 4)/4
self._set_digital_outputs([1, b1, b2, 0, 0, 0, 0, 0])
def _robot_run_full(self):
"""
Set WheeldRobin into full run mode
"""
rospy.loginfo("Setting WheeldRobin to full mode.")
self.robot.safe = False
self.robot.control()
b1 = (self.sensor_state.digital_inputs & 2)/2
b2 = (self.sensor_state.digital_inputs & 4)/4
self._set_digital_outputs([1, b1, b2, 0, 0, 0, 0, 0])
def _set_digital_outputs(self, outputs):
assert len(outputs) == 8, 'Expecting 8 output states.'
byte = 0
for output, state in enumerate(outputs):
byte += (2 ** output) * int(state)
self.robot.set_digital_outputs(byte)
#self.sensor_state.digital_outputs = byte
def set_digital_outputs(self,req):
if not self.robot.sci:
rospy.logwarn("WheeledRobin: robot not connected yet!")
return SetDigitalOutputsResponse(False)
outputs = [req.digital_out_0,req.digital_out_1, req.digital_out_2, req.digital_out_3, req.digital_out_4, req.digital_out_5, req.digital_out_6, req.digital_out_7]
self._set_digital_outputs(outputs)
return SetDigitalOutputsResponse(True)
def set_operation_mode(self,req):
if not self.robot.sci:
rospy.logwarn("WheeledRobin: robot not connected yet!")
return SetTurtlebotModeResponse(False)
self.operate_mode = req.mode
if req.mode == 1: #passive
self._robot_run_passive()
elif req.mode == 2: #safe
self._robot_run_safe()
elif req.mode == 3: #full
self._robot_run_full()
else:
rospy.logerr("Requested an invalid mode.")
return SetTurtlebotModeResponse(False)
return SetTurtlebotModeResponse(True)
def sense(self, sensor_state):
self.sensor_handler.get_all(sensor_state)
#if self._gyro:
# self._gyro.update_calibration(sensor_state)
pass
def cmd_vel(self, msg):
# Clamp to min abs yaw velocity, to avoid trying to rotate at low speeds, which doesn't work well.
if self.min_abs_yaw_vel is not None and msg.angular.z != 0.0 and abs(msg.angular.z) < self.min_abs_yaw_vel:
msg.angular.z = self.min_abs_yaw_vel if msg.angular.z > 0.0 else -self.min_abs_yaw_vel
# Limit maximum yaw
if self.max_abs_yaw_vel is not None and self.max_abs_yaw_vel > 0.0 and msg.angular.z != 0.0 and abs(msg.angular.z) > self.max_abs_yaw_vel:
msg.angular.z = self.max_abs_yaw_vel if msg.angular.z > 0.0 else -self.max_abs_yaw_vel
if self.drive_mode == 'direct_drive':
# TODO
# convert twist to direct_drive args
#ts = msg.linear.x * 1000 # m -> mm
#tw = msg.angular.z * (robot_types.ROBOT_TYPES[self.robot_type].wheel_separation / 2) * 1000
# Prevent saturation at max wheel speed when a compound command is sent.
#if ts > 0:
# ts = min(ts, MAX_WHEEL_SPEED - abs(tw))
#else:
# ts = max(ts, -(MAX_WHEEL_SPEED - abs(tw)))
#self.req_cmd_vel = int(ts - tw), int(ts + tw)
self.req_cmd_vel = msg.linear.x * 1000, msg.angular.z * 1000
elif self.drive_mode == 'drive':
# convert twist to drive args, m->mm (velocity_x, velocity_g)
self.req_cmd_vel = msg.linear.x * 1000, msg.angular.z * 1000
def compute_odom(self, sensor_state, last_time, odom):
"""
Compute current odometry. Updates odom instance and returns tf
transform. compute_odom() does not set frame ids or covariances in
Odometry instance. It will only set stamp, pose, and twist.
@param sensor_state: Current sensor reading
@type sensor_state: WheeledRobinSensorState
@param last_time: time of last sensor reading
@type last_time: rospy.Time
@param odom: Odometry instance to update.
@type odom: nav_msgs.msg.Odometry
@return: transform
@rtype: ( (float, float, float), (float, float, float, float) )
"""
# based on otl_roomba by OTL <*****@*****.**>
current_time = sensor_state.header.stamp
dt = (current_time - last_time).to_sec()
delta_x = sensor_state.linear_velocity * cos(self._pos2d.theta) * dt;
delta_y = sensor_state.linear_velocity * sin(self._pos2d.theta) * dt;
delta_th = sensor_state.angular_velocity * dt;
self._pos2d.x += delta_x
self._pos2d.y += delta_y
self._pos2d.theta += delta_th
# Turtlebot quaternion from yaw. simplified version of tf.transformations.quaternion_about_axis
odom_quat = (0., 0., sin(self._pos2d.theta/2.), cos(self._pos2d.theta/2.))
# construct the transform
# transform = (self._pos2d.x, self._pos2d.y, 0.), odom_quat
# update the odometry state
odom.header.stamp = current_time
odom.pose.pose = Pose(Point(self._pos2d.x, self._pos2d.y, 0.), Quaternion(*odom_quat))
odom.twist.twist = Twist(Vector3(sensor_state.linear_velocity, 0, 0), Vector3(0, 0, sensor_state.angular_velocity))
#if sensor_state.requested_right_velocity == 0 and \
# sensor_state.requested_left_velocity == 0 and \
# sensor_state.distance == 0:
# odom.pose.covariance = ODOM_POSE_COVARIANCE2
#odom.twist.covariance = ODOM_TWIST_COVARIANCE2
#else:
#odom.pose.covariance = ODOM_POSE_COVARIANCE
# odom.twist.covariance = ODOM_TWIST_COVARIANCE
odom.pose.covariance = ODOM_POSE_COVARIANCE
odom.twist.covariance = ODOM_TWIST_COVARIANCE
# construct the transform from footprint to base
base_quat = (0., sin(sensor_state.pitch/2.), 0., cos(sensor_state.pitch/2.))
transformFootprintBase = (0,0,0.055), base_quat
return transformFootprintBase
def publish_odometry_transform(self, odometry):
self.transform_broadcaster.sendTransform(
(odometry.pose.pose.position.x, odometry.pose.pose.position.y, odometry.pose.pose.position.z),
(odometry.pose.pose.orientation.x, odometry.pose.pose.orientation.y, odometry.pose.pose.orientation.z,
odometry.pose.pose.orientation.w),
odometry.header.stamp, odometry.child_frame_id, odometry.header.frame_id)
