import roslib; roslib.load_manifest('roboint')
import rospy
import tf
+import tf.broadcaster
+import tf.transformations
from math import sin, cos, pi
from geometry_msgs.msg import Twist, TransformStamped, Point32
from sensor_msgs.msg import LaserScan
def __init__(self):
rospy.init_node('robo_explorer')
- self.wheel_dist = 0.188 # 18.8cm
- self.wheel_size = 0.052*0.5 # 5.2cm; gear ration=0.5
self.speed = (0, 0)
self.x = 0
self.y = 0
self.alpha = 0
self.last_in = None
- self.tf_broadcaster = tf.TransformBroadcaster()
+ self.tf_broadcaster = tf.broadcaster.TransformBroadcaster()
self.last_time = rospy.Time.now()
+ self.x_last = 0
+ self.y_last = 0
+ self.alpha_last = 0
+
+ self.enable_ultrasonic_laser = int(rospy.get_param('~ultrasonic_laser', "1"))
+ self.wheel_dist = float(rospy.get_param('~wheel_dist', "0.188"))
+ self.wheel_size = float(rospy.get_param('~wheel_size', "0.0255"))
self.pub_motor = rospy.Publisher("ft/set_motor", Motor)
- self.pub_scan = rospy.Publisher("scan", LaserScan)
+ if self.enable_ultrasonic_laser:
+ self.pub_scan = rospy.Publisher("scan", LaserScan)
self.pub_odom = rospy.Publisher("odom", Odometry)
rospy.Subscriber("cmd_vel", Twist, self.cmdVelReceived)
def inputsReceived(self, msg):
current_time = rospy.Time.now()
- self.tf_broadcaster.sendTransform((0.0, 0.0, 0.0), (0.0, 0.0, 0.0, 1.0), current_time, "odom", "map");
- self.send_odometry(msg, current_time)
- self.send_laser_scan(msg, current_time)
-
- self.last_time = current_time
+ self.update_odometry(msg, current_time)
+ if (current_time - self.last_time).to_nsec() > 100e6: # send every 100ms
+ self.send_odometry(msg, current_time)
+ if self.enable_ultrasonic_laser:
+ self.send_laser_scan(msg, current_time)
+ self.last_time = current_time
- def send_odometry(self, msg, current_time):
- dt = (current_time - self.last_time).to_sec();
- in_now = msg.input[1:3]
+ def update_odometry(self, msg, current_time):
+ in_now = msg.input[:2]
if self.last_in is not None:
in_diff = [abs(a - b) for a, b in zip(in_now, self.last_in)] # get changed inputs
+ # fix in_diff from actual motor direction
if self.speed[0] < 0:
in_diff[0] = -in_diff[0]
+ elif self.speed[0] == 0:
+ in_diff[0] = 0
if self.speed[1] < 0:
in_diff[1] = -in_diff[1]
+ elif self.speed[1] == 0:
+ in_diff[1] = 0
dist_dir = (in_diff[1] - in_diff[0])*self.wheel_size*pi/8 # steps_changed in different direction => m
delta_alpha = dist_dir/self.wheel_dist
self.x += delta_x
self.y += delta_y
- # speeds
- vx = delta_x / dt
- vy = delta_y / dt
- valpha = delta_alpha / dt
-
- # since all odometry is 6DOF we'll need a quaternion created from yaw
- odom_quat = tf.transformations.quaternion_from_euler(0, 0, self.alpha)
-
- # first, we'll publish the transform over tf
- self.tf_broadcaster.sendTransform((self.x, self.y, 0.0), odom_quat, current_time, "base_link", "odom");
-
- # next, we'll publish the odometry message over ROS
- odom = Odometry()
- odom.header.stamp = current_time
- odom.header.frame_id = "/odom"
-
- # set the position
- odom.pose.pose.position.x = self.x
- odom.pose.pose.position.y = self.y
- odom.pose.pose.position.z = 0.0
- odom.pose.pose.orientation.x = odom_quat[0]
- odom.pose.pose.orientation.y = odom_quat[1]
- odom.pose.pose.orientation.z = odom_quat[2]
- odom.pose.pose.orientation.w = odom_quat[3]
-
- # set the velocity
- odom.child_frame_id = "base_link";
- odom.twist.twist.linear.x = vx
- odom.twist.twist.linear.y = vy
- odom.twist.twist.angular.z = valpha
-
- # publish the message
- self.pub_odom.publish(odom)
self.last_in = in_now
+
+ def send_odometry(self, msg, current_time):
+ # speeds
+ dt = (current_time - self.last_time).to_sec()
+ vx = (self.x - self.x_last) / dt
+ vy = (self.y - self.y_last) / dt
+ valpha = (self.alpha - self.alpha_last) / dt
+ self.x_last = self.x
+ self.y_last = self.y
+ self.alpha_last = self.alpha
+
+ # since all odometry is 6DOF we'll need a quaternion created from yaw
+ odom_quat = tf.transformations.quaternion_from_euler(0, 0, self.alpha)
+
+ # first, we'll publish the transform over tf
+ self.tf_broadcaster.sendTransform((self.x, self.y, 0.0), odom_quat, current_time, "base_link", "odom")
+
+ # next, we'll publish the odometry message over ROS
+ odom = Odometry()
+ odom.header.stamp = current_time
+ odom.header.frame_id = "/odom"
+
+ # set the position
+ odom.pose.pose.position.x = self.x
+ odom.pose.pose.position.y = self.y
+ odom.pose.pose.position.z = 0.0
+ odom.pose.pose.orientation.x = odom_quat[0]
+ odom.pose.pose.orientation.y = odom_quat[1]
+ odom.pose.pose.orientation.z = odom_quat[2]
+ odom.pose.pose.orientation.w = odom_quat[3]
+
+ # set the velocity
+ odom.child_frame_id = "base_link"
+ odom.twist.twist.linear.x = vx
+ odom.twist.twist.linear.y = vy
+ odom.twist.twist.angular.z = valpha
+
+ # publish the message
+ self.pub_odom.publish(odom)
def send_laser_scan(self, msg, current_time):
# first, we'll publish the transform over tf
- self.tf_broadcaster.sendTransform((0.06, 0.0, 0.0), (0.0, 0.0, 0.0, 1.0), current_time, "scan", "base_link");
+ self.tf_broadcaster.sendTransform((0.06, 0.0, 0.0), (0.0, 0.0, 0.0, 1.0), current_time, "scan", "base_link")
# actually ultra sonic range finder
+ num_points = 60 # The base planner needs at least 30 points to work in the default config
+ opening_angle = 30*pi/180 # each side
scan = LaserScan()
scan.header.stamp = current_time
scan.header.frame_id = "/scan"
- scan.angle_min = -pi/4;
- scan.angle_max = pi/4;
- scan.angle_increment = pi/4;
- scan.time_increment = 0.01;
- scan.range_min = 0.0;
- scan.range_max = 4.0;
- for i in range(3):
+ scan.angle_min = -opening_angle
+ scan.angle_max = opening_angle
+ scan.angle_increment = (2*opening_angle)/num_points
+ scan.time_increment = 0.0
+ scan.range_min = 0.0
+ scan.range_max = 4.0
+ for i in range(num_points):
scan.ranges.append(msg.d1/100.0)
- scan.intensities.append(0.5)
- scan.intensities.append(1.0)
- scan.intensities.append(0.5)
+ #scan.intensities.append(0.5)
+ #scan.intensities.append(1.0)
+ #scan.intensities.append(0.5)
self.pub_scan.publish(scan)
# test with rostopic pub -1 cmd_vel geometry_msgs/Twist '[0, 0, 0]' '[0, 0, 0]'
if speed_r < -7: speed_r = -7
elif speed_r > 7: speed_r = 7
+ #print "Speed wanted: %.2f %.2f, set: %d %d" % (trans, rot*180/pi, round(speed_l), round(speed_r))
+
outmsg = Motor()
outmsg.num = 1
outmsg.speed = round(speed_l)