#!/usr/bin/env python
import roslib; roslib.load_manifest('roboint')
import rospy
-import tf
-from math import sin, cos, pi
-from geometry_msgs.msg import Twist, TransformStamped, Point32
-from sensor_msgs.msg import LaserScan
-from nav_msgs.msg import Odometry
-from roboint.msg import Motor
+from math import *
+from sensor_msgs.msg import Range
from roboint.msg import Inputs
class RoboExplorer:
def __init__(self):
rospy.init_node('robo_explorer')
-
- rospy.Subscriber("cmd_vel", Twist, self.cmdVelReceived)
- rospy.Subscriber("ft/get_inputs", Inputs, self.inputsReceived)
-
- self.pub_motor = rospy.Publisher("ft/set_motor", Motor)
- self.pub_scan = rospy.Publisher("base_scan", LaserScan)
- self.pub_odom = rospy.Publisher("odom", Odometry)
- self.wheel_dist = 0.188 # 18.8cm
- self.wheel_size = 0.052*0.5 # 5.1cm gear ration=0.5
- self.speed = (0, 0)
- self.x = 0
- self.y = 0
- self.alpha = 0
- self.last_in = [0, 0]
- self.tf_broadcaster = tf.TransformBroadcaster()
self.last_time = rospy.Time.now()
+ self.pub_sonar = rospy.Publisher("sonar", Range, queue_size=16)
+ rospy.Subscriber("ft/get_inputs", Inputs, self.inputsReceived)
rospy.spin()
-
+
def inputsReceived(self, msg):
current_time = rospy.Time.now()
- self.send_odometry(msg, current_time)
- 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]
- in_diff = [abs(a - b) for a, b in zip(in_now, self.last_in)] # get changed inputs
- if self.speed[0] < 0:
- in_diff[0] = -in_diff[0]
- if self.speed[1] < 0:
- in_diff[1] = -in_diff[1]
-
- 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
-
- dist = (in_diff[0] + in_diff[1])/2.0*self.wheel_size*pi/8 # steps_changed same direction => m
-
- delta_x = cos(self.alpha + delta_alpha/2)*dist
- delta_y = sin(self.alpha + delta_alpha/2)*dist
-
- self.alpha += delta_alpha
- if self.alpha > 2*pi:
- self.alpha -= 2*pi
- elif self.alpha < -2*pi:
- self.alpha += 2*pi
- self.x += delta_x
- self.y += delta_y
- self.last_in = in_now
-
- # 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)
+ #self.update_odometry(msg, current_time)
+ if (current_time - self.last_time).to_nsec() > 100e6: # send every 100ms
+ #self.send_odometry(msg, current_time)
+ self.send_range(msg, current_time)
+ self.last_time = current_time
- # first, we'll publish the transform over tf
- self.tf_broadcaster.sendTransform((0.0, 0.0, 0.0), odom_quat, current_time, "odom", "base_link");
-
- # 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 = odom_quat
-
- # 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, "base_link", "base_scan");
-
- # actually ultra sonic range finder
- scan = LaserScan()
+ def send_range(self, msg, current_time):
+ # ultra sonic range finder
+ scan = Range()
scan.header.stamp = current_time
- scan.header.frame_id = "base_link"
- 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.ranges.append(msg.d1/100.0)
- 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]'
- def cmdVelReceived(self, msg):
- trans = msg.linear.x
- rot = msg.angular.z # rad/s
-
- # handle rotation as offset to speeds
- speed_offset = (rot * self.wheel_dist)/2.0 # m/s
-
- # handle translation
- speed_l = 0
- wish_speed_left = trans - speed_offset
- if abs(wish_speed_left) > 1.7/64.3:
- speed_l = 64.3*abs(wish_speed_left) - 1.7
- if wish_speed_left < 0:
- speed_l*=-1
- speed_r = 0
- wish_speed_right = trans + speed_offset
- if abs(wish_speed_right) > 1.7/64.3:
- speed_r = 64.3*abs(wish_speed_right) - 1.7
- if wish_speed_right < 0:
- speed_r*=-1
-
- # check limits
- if speed_l < -7: speed_l = -7
- elif speed_l > 7: speed_l = 7
- if speed_r < -7: speed_r = -7
- elif speed_r > 7: speed_r = 7
-
- outmsg = Motor()
- outmsg.num = 1
- outmsg.speed = round(speed_l)
- self.pub_motor.publish(outmsg)
-
- outmsg = Motor()
- outmsg.num = 2
- outmsg.speed = round(speed_r)
- self.pub_motor.publish(outmsg)
-
- self.speed = (speed_l, speed_r)
+ scan.header.frame_id = "forward_sensor"
+ scan.radiation_type = 0
+ scan.field_of_view = 60*pi/180
+ scan.min_range = 0.0
+ scan.max_range = 4.0
+ scan.range = msg.d1/100.0
+ self.pub_sonar.publish(scan)
if __name__ == '__main__':
RoboExplorer()
projects / ros_roboint.git / blobdiff