2. Sonars Theory of operation: The SRF-08 emits an ultrasonic pulse, then waits for an echo to return. Based on the time between the pulse generation and echo return, the sensor calculates the distance from its rear face to the detected surface, and then reports the distance in centimeters over the i2c interface.

3. Behavior Row1 Row0 Row2 Row3 Y target distance X target distance

4. Sensor Integration The platform houses an array of sonars. Two sonars are mounted along the right face of the platform, equidistantly ahead of and behind the drive wheels. Another sonar points ahead of the platform. SRF08

5. Sensor Integration The array of sonars allows the robot to determine its position in 2D space relative to two perpendicular vertical surfaces, such as the corner of a room. Having sonars on two perpendicular faces of the platform allows the robot to determine its distance from the two surfaces, while positioning two of the sonars on the same face allows it to determine its relative rotation or parallelism. SRF08 Distance 1 Distance 2 Distance 3

6. Sensor Integration SRF08 Distance 1 = Distance 2 SRF08 Distance 1 =/= Distance 2 Opposite = Distance2-Distance1 SRF08 Xdist Ydist = (Distance 1 + Distance 2)/2

7. import math import smbus import time import servo5 import servo8 import srf08_1 import srf08_2 import srf08_3 servo5.direction(heading = 'blah') row = 0 time.sleep(30) while row < 12: ytarg = 20 + 5*row xtarg = 50 - 30*math.pow(-1, row) print "xtarg is" print xtarg xrng = srf08_3.srf() print "xrng is" print xrng while xrng >= xtarg : rng = srf08_1.srf() rng2 = srf08_2.srf() ydist = (rng+rng2)/2 yerr = (ydist-ytarg) opposite = rng-rng2 servo8.direction("forward", yerr, opposite) time.sleep(.05) xrng = srf08_3.srf() print "xrng" print xrng servo8.direction("left", yerr, opposite) time.sleep(1.8) servo8.direction("straight", yerr, opposite) time.sleep(.45) servo8.direction("right", yerr, opposite) time.sleep(1.5) row = row+1 print "row" print row ytarg = 20 + 5*row xtarg = 50 - 30*math.pow(-1, row) print "xtarg is" print xtarg xrng = srf08_3.srf() print "xrng is" print xrng while xrng <= xtarg : rng = srf08_1.srf() rng2 = srf08_2.srf() ydist = (rng+rng2)/2 yerr = (ydist-ytarg) opposite = rng-rng2 servo8.direction("backward", yerr, opposite) time.sleep(.05) xrng = srf08_3.srf() print "xrng" print xrng servo8.direction("left", yerr, opposite) time.sleep(1.8) servo8.direction("straight", yerr, opposite) time.sleep(.45) servo8.direction("right", yerr, opposite) time.sleep(1.5) row = row+1 print "row" print row servo8.direction("x", yerr, opposite) Navigation Programming

8. def color( ydist, xdist ): import numpy import servodraw a = [[1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ], [1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, ], [0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, ], [0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, ], [0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, ], [0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, ], [0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, ], [0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, ], [0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, ], [0, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 0, ], [1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, ], [1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, ]] y = int(ydist) x = int(xdist) print y print x b = a[y][x] servodraw.direction(b) return b Print Programming def direction( heading ): import Adafruit_BBIO.PWM as PWM servo_pin = "P8_19" duty_min = 3 duty_max = 14.5 duty_span = duty_max - duty_min if heading == 'x': PWM.cleanup() return elif heading == '1': angle = 180 elif heading == '0': angle = 0 else: angle = 90 angle_f = float(angle) duty = ((angle_f / 180) * duty_span + duty_min) PWM.set_duty_cycle(servo_pin, duty) return