scripts/move_base.py

   1 #!/usr/bin/env python
   2 # -*- coding: iso-8859-15 -*-
   3
   4 import rospy
   5 import tf
   6 import struct
   7 from i2c import *
   8 from math import *
   9 from geometry_msgs.msg import Twist
  10 from nav_msgs.msg import Odometry
  11 from diagnostic_msgs.msg import DiagnosticArray, DiagnosticStatus, KeyValue
  12 from sensor_msgs.msg import Imu, Range
  13
  14 WHEEL_DIST = 0.248
  15
  16 class MoveBase:
  17         def __init__(self):
  18                 rospy.init_node('wild_thumper_move_base')
  19                 rospy.Subscriber("cmd_vel", Twist, self.cmdVelReceived)
  20                 rospy.Subscriber("imu", Imu, self.imuReceived)
  21                 enable_odom_tf = rospy.get_param("~enable_odom_tf", True)
  22                 if enable_odom_tf:
  23                         self.tf_broadcaster = tf.broadcaster.TransformBroadcaster()
  24                 else:
  25                         self.tf_broadcaster = None
  26                 self.pub_odom = rospy.Publisher("odom", Odometry, queue_size=16)
  27                 self.pub_diag = rospy.Publisher("diagnostics", DiagnosticArray, queue_size=16)
  28                 self.pub_range_fwd = rospy.Publisher("range_forward", Range, queue_size=16)
  29                 self.pub_range_bwd = rospy.Publisher("range_backward", Range, queue_size=16)
  30                 self.pub_range_left = rospy.Publisher("range_left", Range, queue_size=16)
  31                 self.pub_range_right = rospy.Publisher("range_right", Range, queue_size=16)
  32                 self.set_speed(0, 0)
  33                 rospy.loginfo("Init done")
  34                 i2c_write_reg(0x50, 0x90, struct.pack("BB", 1, 1)) # switch direction
  35                 self.handicap_last = (-1, -1)
  36                 self.run()
  37
  38         def run(self):
  39                 rate = rospy.Rate(20.0)
  40                 reset_val = self.get_reset()
  41                 rospy.loginfo("Reset Status: 0x%x" % reset_val)
  42                 while not rospy.is_shutdown():
  43                         #print struct.unpack(">B", i2c_read_reg(0x50, 0xA2, 1))[0] # count test
  44                         self.get_tle_err()
  45                         self.get_odom()
  46                         self.get_voltage()
  47                         self.get_dist_forward()
  48                         self.get_dist_backward()
  49                         self.get_dist_left()
  50                         self.get_dist_right()
  51                         rate.sleep()
  52
  53         def set_motor_handicap(self, front, aft): # percent
  54                 if self.handicap_last != (front, aft):
  55                         i2c_write_reg(0x50, 0x94, struct.pack(">bb", front, aft))
  56                         self.handicap_last = (front, aft)
  57
  58         def imuReceived(self, msg):
  59                 (roll, pitch, yaw) = tf.transformations.euler_from_quaternion(msg.orientation.__getstate__())
  60                 if pitch > 30*pi/180:
  61                         val = (100.0/65)*abs(pitch)*180/pi
  62                         self.set_motor_handicap(0, int(val))
  63                 elif pitch < -30*pi/180:
  64                         val = (100.0/65)*abs(pitch)*180/pi
  65                         self.set_motor_handicap(int(val), 0)
  66                 else:
  67                         self.set_motor_handicap(0, 0)
  68
  69         def get_reset(self):
  70                 reset = struct.unpack(">B", i2c_read_reg(0x50, 0xA0, 1))[0]
  71
  72                 msg = DiagnosticArray()
  73                 msg.header.stamp = rospy.Time.now()
  74                 stat = DiagnosticStatus()
  75                 stat.name = "Reset reason"
  76                 stat.level = DiagnosticStatus.ERROR if reset & 0x0c else DiagnosticStatus.OK
  77                 stat.message = "0x%02x" % reset
  78
  79                 stat.values.append(KeyValue("Watchdog Reset Flag", str(bool(reset & (1 << 3)))))
  80                 stat.values.append(KeyValue("Brown-out Reset Flag", str(bool(reset & (1 << 2)))))
  81                 stat.values.append(KeyValue("External Reset Flag", str(bool(reset & (1 << 1)))))
  82                 stat.values.append(KeyValue("Power-on Reset Flag", str(bool(reset & (1 << 0)))))
  83
  84                 msg.status.append(stat)
  85                 self.pub_diag.publish(msg)
  86                 return reset
  87
  88
  89         def get_tle_err(self):
  90                 err = struct.unpack(">B", i2c_read_reg(0x50, 0xA1, 1))[0]
  91
  92                 msg = DiagnosticArray()
  93                 msg.header.stamp = rospy.Time.now()
  94                 stat = DiagnosticStatus()
  95                 stat.name = "Motor: Error Status"
  96                 stat.level = DiagnosticStatus.ERROR if err else DiagnosticStatus.OK
  97                 stat.message = "0x%02x" % err
  98
  99                 stat.values.append(KeyValue("aft left", str(bool(err & (1 << 0)))))
 100                 stat.values.append(KeyValue("front left", str(bool(err & (1 << 1)))))
 101                 stat.values.append(KeyValue("front right", str(bool(err & (1 << 2)))))
 102                 stat.values.append(KeyValue("aft right", str(bool(err & (1 << 3)))))
 103
 104                 msg.status.append(stat)
 105                 self.pub_diag.publish(msg)
 106
 107         def get_voltage(self):
 108                 volt = struct.unpack(">h", i2c_read_reg(0x52, 0x09, 2))[0]/100.0
 109
 110                 msg = DiagnosticArray()
 111                 msg.header.stamp = rospy.Time.now()
 112                 stat = DiagnosticStatus()
 113                 stat.name = "Voltage"
 114                 stat.level = DiagnosticStatus.ERROR if volt < 7 else DiagnosticStatus.OK
 115                 stat.message = "%.2fV" % volt
 116
 117                 msg.status.append(stat)
 118                 self.pub_diag.publish(msg)
 119
 120
 121         def get_odom(self):
 122                 posx, posy, angle = struct.unpack(">fff", i2c_read_reg(0x50, 0x40, 12))
 123                 speed_trans, speed_rot = struct.unpack(">ff", i2c_read_reg(0x50, 0x38, 8))
 124                 current_time = rospy.Time.now()
 125
 126                 # since all odometry is 6DOF we'll need a quaternion created from yaw
 127                 odom_quat = tf.transformations.quaternion_from_euler(0, 0, angle)
 128
 129                 # first, we'll publish the transform over tf
 130                 if self.tf_broadcaster is not None:
 131                         self.tf_broadcaster.sendTransform((posx, posy, 0.0), odom_quat, current_time, "base_footprint", "odom")
 132
 133                 # next, we'll publish the odometry message over ROS
 134                 odom = Odometry()
 135                 odom.header.stamp = current_time
 136                 odom.header.frame_id = "/odom"
 137
 138                 # set the position
 139                 odom.pose.pose.position.x = posx
 140                 odom.pose.pose.position.y = posy
 141                 odom.pose.pose.position.z = 0.0
 142                 odom.pose.pose.orientation.x = odom_quat[0]
 143                 odom.pose.pose.orientation.y = odom_quat[1]
 144                 odom.pose.pose.orientation.z = odom_quat[2]
 145                 odom.pose.pose.orientation.w = odom_quat[3]
 146                 odom.pose.covariance[0] = 1e-3 # x
 147                 odom.pose.covariance[7] = 1e-3 # y
 148                 odom.pose.covariance[14] = 1e6 # z
 149                 odom.pose.covariance[21] = 1e6 # rotation about X axis
 150                 odom.pose.covariance[28] = 1e6 # rotation about Y axis
 151                 odom.pose.covariance[35] = 0.1 # rotation about Z axis
 152
 153                 # set the velocity
 154                 odom.child_frame_id = "base_footprint"
 155                 odom.twist.twist.linear.x = speed_trans
 156                 odom.twist.twist.linear.y = 0.0
 157                 odom.twist.twist.angular.z = speed_rot
 158                 odom.twist.covariance[0] = 1e-3 # x
 159                 odom.twist.covariance[7] = 1e-3 # y
 160                 odom.twist.covariance[14] = 1e6 # z
 161                 odom.twist.covariance[21] = 1e6 # rotation about X axis
 162                 odom.twist.covariance[28] = 1e6 # rotation about Y axis
 163                 odom.twist.covariance[35] = 0.1 # rotation about Z axis
 164
 165                 # publish the message
 166                 self.pub_odom.publish(odom)
 167
 168
 169         def set_speed(self, trans, rot):
 170                 i2c_write_reg(0x50, 0x50, struct.pack(">ff", trans, rot))
 171
 172         def cmdVelReceived(self, msg):
 173                 trans = msg.linear.x
 174                 rot = msg.angular.z # rad/s
 175                 self.set_speed(trans, rot)
 176
 177         # http://rn-wissen.de/wiki/index.php/Sensorarten#Sharp_GP2D12
 178         def get_dist_ir(self, num):
 179                 dev = i2c(0x52)
 180                 s = struct.pack("B", num)
 181                 dev.write(s)
 182                 dev.close()
 183
 184                 sleep(2e-6)
 185
 186                 dev = i2c(0x52)
 187                 s = dev.read(2)
 188                 dev.close()
 189
 190                 val = struct.unpack(">H", s)[0]
 191                 return 15221/(val - -276.42)/100;
 192
 193         def get_dist_srf(self, num):
 194                 dev = i2c(0x52)
 195                 s = struct.pack("B", num)
 196                 dev.write(s)
 197                 dev.close()
 198
 199                 sleep(50e-3)
 200
 201                 dev = i2c(0x52)
 202                 s = dev.read(2)
 203                 dev.close()
 204
 205                 return struct.unpack(">H", s)[0]/1000.0
 206
 207         def send_range(self, pub, frame_id, typ, dist, min_range, max_range, fov_deg):
 208                 msg = Range()
 209                 msg.header.stamp = rospy.Time.now()
 210                 msg.header.frame_id = frame_id
 211                 msg.radiation_type = typ
 212                 msg.field_of_view = fov_deg*pi/180
 213                 msg.min_range = min_range
 214                 msg.max_range = max_range
 215                 msg.range = dist
 216                 pub.publish(msg)
 217
 218         def get_dist_left(self):
 219                 if self.pub_range_left.get_num_connections() > 0:
 220                         dist = self.get_dist_ir(0x1)
 221                         self.send_range(self.pub_range_left, "ir_left", Range.INFRARED, dist, 0.1, 0.8, 5)
 222
 223         def get_dist_right(self):
 224                 if self.pub_range_right.get_num_connections() > 0:
 225                         dist = self.get_dist_ir(0x3)
 226                         self.send_range(self.pub_range_right, "ir_right", Range.INFRARED, dist, 0.1, 0.8, 5)
 227
 228         def get_dist_forward(self):
 229                 if self.pub_range_fwd.get_num_connections() > 0:
 230                         dist = self.get_dist_srf(0x5)
 231                         self.send_range(self.pub_range_fwd, "sonar_forward", Range.ULTRASOUND, dist, 0.04, 6, 60)
 232
 233         def get_dist_backward(self):
 234                 if self.pub_range_bwd.get_num_connections() > 0:
 235                         dist = self.get_dist_srf(0x7)
 236                         self.send_range(self.pub_range_bwd, "sonar_backward", Range.ULTRASOUND, dist, 0.04, 6, 60)
 237
 238
 239 if __name__ == "__main__":
 240         MoveBase()