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
  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                 self.tf_broadcaster = tf.broadcaster.TransformBroadcaster()
  22                 self.pub_odom = rospy.Publisher("odom", Odometry, queue_size=16)
  23                 self.pub_diag = rospy.Publisher("diagnostics", DiagnosticArray, queue_size=16)
  24                 self.set_speed(0, 0)
  25                 rospy.loginfo("Init done")
  26                 i2c_write_reg(0x50, 0x90, struct.pack("BB", 1, 1)) # switch direction
  27                 self.run()
  28
  29         def run(self):
  30                 rate = rospy.Rate(20.0)
  31                 reset_val = self.get_reset()
  32                 rospy.loginfo("Reset Status: 0x%x" % reset_val)
  33                 while not rospy.is_shutdown():
  34                         #print struct.unpack(">B", i2c_read_reg(0x50, 0xA2, 1))[0] # count test
  35                         self.get_tle_err()
  36                         self.get_odom()
  37                         self.get_voltage()
  38                         #self.get_dist_forward()
  39                         #self.get_dist_backward()
  40                         #self.get_dist_left()
  41                         #self.get_dist_right()
  42                         rate.sleep()
  43
  44         def set_motor_handicap(self, front, aft): # percent
  45                 i2c_write_reg(0x50, 0x94, struct.pack(">bb", front, aft))
  46
  47         def imuReceived(self, msg):
  48                 (roll, pitch, yaw) = tf.transformations.euler_from_quaternion(msg.orientation.__getstate__())
  49                 if pitch > 30*pi/180:
  50                         val = (100/90)*abs(pitch)*180/pi
  51                         print "aft handicap", val
  52                         self.set_motor_handicap(0, val)
  53                 elif pitch < -30*pi/180:
  54                         val = (100/90)*abs(pitch)*180/pi
  55                         print "front handicap", val
  56                         self.set_motor_handicap(val, 0)
  57                 else:
  58                         self.set_motor_handicap(0, 0)
  59
  60         def get_reset(self):
  61                 reset = struct.unpack(">B", i2c_read_reg(0x50, 0xA0, 1))[0]
  62
  63                 msg = DiagnosticArray()
  64                 msg.header.stamp = rospy.Time.now()
  65                 stat = DiagnosticStatus()
  66                 stat.name = "Reset reason"
  67                 stat.level = DiagnosticStatus.ERROR if reset & 0x0c else DiagnosticStatus.OK
  68                 stat.message = "0x%02x" % reset
  69
  70                 stat.values.append(KeyValue("Watchdog Reset Flag", str(bool(reset & (1 << 3)))))
  71                 stat.values.append(KeyValue("Brown-out Reset Flag", str(bool(reset & (1 << 2)))))
  72                 stat.values.append(KeyValue("External Reset Flag", str(bool(reset & (1 << 1)))))
  73                 stat.values.append(KeyValue("Power-on Reset Flag", str(bool(reset & (1 << 0)))))
  74
  75                 msg.status.append(stat)
  76                 self.pub_diag.publish(msg)
  77                 return reset
  78
  79
  80         def get_tle_err(self):
  81                 err = struct.unpack(">B", i2c_read_reg(0x50, 0xA1, 1))[0]
  82
  83                 msg = DiagnosticArray()
  84                 msg.header.stamp = rospy.Time.now()
  85                 stat = DiagnosticStatus()
  86                 stat.name = "Motor: Error Status"
  87                 stat.level = DiagnosticStatus.ERROR if err else DiagnosticStatus.OK
  88                 stat.message = "0x%02x" % err
  89
  90                 stat.values.append(KeyValue("aft left", str(bool(err & (1 << 0)))))
  91                 stat.values.append(KeyValue("front left", str(bool(err & (1 << 1)))))
  92                 stat.values.append(KeyValue("front right", str(bool(err & (1 << 2)))))
  93                 stat.values.append(KeyValue("aft right", str(bool(err & (1 << 3)))))
  94
  95                 msg.status.append(stat)
  96                 self.pub_diag.publish(msg)
  97
  98         def get_voltage(self):
  99                 volt = struct.unpack(">h", i2c_read_reg(0x52, 0x09, 2))[0]/100.0
 100
 101                 msg = DiagnosticArray()
 102                 msg.header.stamp = rospy.Time.now()
 103                 stat = DiagnosticStatus()
 104                 stat.name = "Voltage"
 105                 stat.level = DiagnosticStatus.ERROR if volt < 7 else DiagnosticStatus.OK
 106                 stat.message = "%.2fV" % volt
 107
 108                 msg.status.append(stat)
 109                 self.pub_diag.publish(msg)
 110
 111
 112         def get_odom(self):
 113                 posx, posy, angle = struct.unpack(">fff", i2c_read_reg(0x50, 0x40, 12))
 114                 speed_trans, speed_rot = struct.unpack(">ff", i2c_read_reg(0x50, 0x38, 8))
 115                 current_time = rospy.Time.now()
 116
 117                 # since all odometry is 6DOF we'll need a quaternion created from yaw
 118                 odom_quat = tf.transformations.quaternion_from_euler(0, 0, angle)
 119
 120                 # first, we'll publish the transform over tf
 121                 self.tf_broadcaster.sendTransform((posx, posy, 0.0), odom_quat, current_time, "base_link", "odom")
 122
 123                 # next, we'll publish the odometry message over ROS
 124                 odom = Odometry()
 125                 odom.header.stamp = current_time
 126                 odom.header.frame_id = "/odom"
 127
 128                 # set the position
 129                 odom.pose.pose.position.x = posx
 130                 odom.pose.pose.position.y = posy
 131                 odom.pose.pose.position.z = 0.0
 132                 odom.pose.pose.orientation.x = odom_quat[0]
 133                 odom.pose.pose.orientation.y = odom_quat[1]
 134                 odom.pose.pose.orientation.z = odom_quat[2]
 135                 odom.pose.pose.orientation.w = odom_quat[3]
 136
 137                 # set the velocity
 138                 odom.child_frame_id = "base_link"
 139                 odom.twist.twist.linear.x = speed_trans
 140                 odom.twist.twist.linear.y = 0.0
 141                 odom.twist.twist.angular.z = speed_rot
 142
 143                 # publish the message
 144                 self.pub_odom.publish(odom)
 145
 146
 147         def set_speed(self, trans, rot):
 148                 i2c_write_reg(0x50, 0x50, struct.pack(">ff", trans, rot))
 149
 150         def cmdVelReceived(self, msg):
 151                 trans = msg.linear.x
 152                 rot = msg.angular.z # rad/s
 153                 self.set_speed(trans, rot)
 154
 155         # http://rn-wissen.de/wiki/index.php/Sensorarten#Sharp_GP2D12
 156         def get_dist_ir(self, num):
 157                 dev = i2c(0x52)
 158                 s = struct.pack("B", num)
 159                 dev.write(s)
 160                 dev.close()
 161
 162                 sleep(2e-6)
 163
 164                 dev = i2c(0x52)
 165                 s = dev.read(2)
 166                 dev.close()
 167
 168                 val = struct.unpack(">H", s)[0]
 169                 return 15221/(val - -276.42)/100;
 170
 171         def get_dist_srf(self, num):
 172                 dev = i2c(0x52)
 173                 s = struct.pack("B", num)
 174                 dev.write(s)
 175                 dev.close()
 176
 177                 sleep(50e-3)
 178
 179                 dev = i2c(0x52)
 180                 s = dev.read(2)
 181                 dev.close()
 182
 183                 return struct.unpack(">H", s)[0]/1000.0
 184
 185         def get_dist_left(self):
 186                 dist = self.get_dist_ir(0x1)
 187
 188         def get_dist_right(self):
 189                  dist = self.get_dist_ir(0x3)
 190
 191         def get_dist_forward(self):
 192                 dist = self.get_dist_srf(0x5)
 193
 194         def get_dist_backward(self):
 195                 dist = self.get_dist_srf(0x7)
 196
 197
 198 if __name__ == "__main__":
 199         MoveBase()