Roomba project - Revision history

AndreaBonarini at 14:40, 28 December 2011

2011-12-28T14:40:12Z

AndreaBonarini at 08:29, 9 June 2011

2011-06-09T08:29:29Z

AndreaScalise: /* Connecting Roomba and Pyro */

2010-09-13T10:24:48Z

‎Connecting Roomba and Pyro

AndreaScalise: /* Roomba's Pyro files configuration */

2010-09-13T10:14:21Z

‎Roomba's Pyro files configuration

AndreaScalise: /* Wall following algorithm */

2010-09-12T18:35:50Z

‎Wall following algorithm

AndreaScalise: /* Init function */

2010-09-12T18:18:37Z

‎Init function

AndreaScalise: /* Roomba's Pyro files configuration */

2010-09-10T20:41:21Z

‎Roomba's Pyro files configuration

AndreaScalise: /* Connecting Roomba and Pyro */

2010-09-03T15:08:58Z

‎Connecting Roomba and Pyro

AndreaScalise: /* Connecting Roomba and Pyro */

2010-09-03T15:07:31Z

‎Connecting Roomba and Pyro

AndreaScalise: /* Connecting Roomba and Pyro */

2010-09-03T15:01:19Z

‎Connecting Roomba and Pyro

@@ Line 10: / Line 10: @@
 |start=2010/05/10
 |end=2011/09/25
-|status=Active
+|status=Closed
 |level=Ms
 |type=Course

@@ Line 5: / Line 5: @@
 |coordinator=GiuseppinaGini
 |tutor=ThomasFerrari
-|students=AndreaScalise; NiccoloTenti
+|students=AndreaScalise; NiccoloTenti; MohammedAli;
 |resarea=Robotics
 |restopic=Robot development;
 |start=2010/05/10
-|end=2010/09/25
+|end=2011/09/25
 |status=Active
 |level=Ms

@@ Line 308: / Line 308: @@
 Now, we are ready to test our wall following algorithm on a real Roomba.
 First of all, you need a way to connect physically the robot with a computer: on the Roomba Airwiki page ([[Roomba - vacuuming robots|Roomba]]) you can find different ways to connect a Roomba with a pc: we will use a modified USB cable. If you have some experiences in electronics, you will manage to build your own cable following the instructions explained in this website: http://todbot.com/blog/2006/07/19/roombongle-a-roomba-usb-dongle/#more-119.
 Then, you can run Pyro interface as explained before: all the commands are very clear and easy to understand. We will explain the two basic buttons useful to run the wall following brain, situated in the middle of the window, on the left (but also in the struments panel on the top).
@@ Line 316: / Line 316: @@
   /dev/ttyUSBx
 where "x" indicates the USB port number you are using on your pc.
-About the transfer rate, a value of 115200 is good (if you use a Zigbee connection way, this value could be less).
+About the transfer rate, a value of 115200 is good (if you use a Zigbee connection way, it's recommended to lower this value to 96800, because we experimented that the connection was more stable in this way).
 If everything is correct, Pyro should write a confirmation message on the main board.

@@ Line 66: / Line 66: @@
   self.sensorData['angleInRadians'] = (2.0 * self.sensorData['rawAngle']) / 38.5
-This depends on how the Roomba sensors process the information, and probably it worked for another model of Roomba. The value 38.5 was obtained in experimental way: we made the Roomba do a 360 degrees turn, and registered the rotation degrees value shown on Pyro interface (it was 57 instead of 360). In order to increment the degrees value to 360 (in progress)
+This depends on how the Roomba sensors process the information, and probably it worked for another model of Roomba. The value 38.5 was obtained in experimental way: we made the Roomba do a 360 degrees turn, and registered the rotation degrees value shown on Pyro interface (it was about 0.99 radians instead of 6.28). In order to increment the degrees value to 6.28, we multiplied the value in radians observed for 258, and then, making the hypotesis that during the rotation the sensor detects the rotation angle in linear way, we divided the result for 6.28. Since the sensor detects discrete values, the number 38.5 is very approximative, and the correct angle shown on the Pyro interface could change if you make the Roomba do a complete rotation at once, or if you do a complete rotation step by step. However, we think that 38.5 can be a good choice for a working algorithm.
 At line 318, you have to substitute the value '0.001' with '0.01' in the following line, since the distance run by the Roomba is in centimeters; the old code was:
   d = self.sensorData['distance'] * 0.001
-and must be substituted with
+and must be substituted with:
   d = self.sensorData['distance'] * 0.01
-In the end, at line 319, a '-' is needed instead of the '+'
+In the end, at line 319, a '-' is needed instead of the '+', because the movement forward and backward are inverted, so the code:
   self.x += math.cos(a) * d
   self.y += math.sin(a) * d
 == Wall following algorithm ==

← Older revision		Revision as of 18:35, 12 September 2010
Line 197:		Line 197:

	This function just initializes the finite state machine, creating a new brain (brain = FSMBrain("Wall Following Brain", engine)) and adding all the states we created in the machine.		This function just initializes the finite state machine, creating a new brain (brain = FSMBrain("Wall Following Brain", engine)) and adding all the states we created in the machine.
		+
		+	=== Finite state machine scheme ===
		+
		+	Here we show the behavioural functioning described just now, representing it by a conventional finite state machine automaton.
		+
		+	Every circle describes a state, so we have four circles for the four states in the algorithm. The arrows represent the transictions between one state to another, which is done in the algorithm through the function "goto". The arrow without origin, entering the "findWall" state indicates that that state is the initial one.
		+
		+	It's important to notice that the algorithm presented doesn't have a final state, but it ends up in a infinite loop, allowing the Roomba to work until a forced stop.
		+
		+	[[Image:FSM-HighRes.jpg‎ \| center]]
		+

	=== Complete algorithm ===		=== Complete algorithm ===

@@ Line 196: / Line 196: @@
          return brain
-This function just initializes the finite state machine, creating a new brain (brain = FSMBrain("Wall Following Brain", engine)) and adding all the states we created in the machine
+This function just initializes the finite state machine, creating a new brain (brain = FSMBrain("Wall Following Brain", engine)) and adding all the states we created in the machine.
 === Complete algorithm ===

@@ Line 55: / Line 55: @@
   dev.sendMsg('\x89\x00\x80\x00\x00')
-You should change the last '0' with a '1'. This piece of code represents the bytes sent to the Roomba to force the rotation anticlockwise, but with the final zero, it represents a translation forward.
+You should change the last '0' with a '1', so that it will look like the following:
-At line 316, you can find the code which transforms the value related to the rotation angle got by the sensors in radians. You should replace the value '258' with '38.5':
+This piece of code represents the bytes sent to the Roomba to force the rotation anticlockwise, but with the final zero, it represents a translation forward.
   self.sensorData['angleInRadians'] = (2.0 * self.sensorData['rawAngle']) / 258
-At line 318, you have to substitute the value '0.001' with '0.01' in the following line, since the distance run by the Roomba is in centimeters:
+and then it will be:
   d = self.sensorData['distance'] * 0.001
 In the end, at line 319, a '-' is needed instead of the '+'

@@ Line 295: / Line 295: @@
 '''Brain button''': with this button, you can load one of the brains for your robot. If you put the .py file with the wall following algorithm in the folder we specified before, then it will appear in the list: just select it.
 Now you just have to press the Run button in the middle of the window, and Roomba will start to behave in the way we specified in the algorithm.
-We show three short videos of Roomba in action. We experienced some issues when Roomba has to follow dark walls. In fact, the IR wall sensor seems not to detect these kind of surfaces, so the algorithm doesn't work properly then, but it will force Roomba to follow "blindly" the wall.
+We will show now three short videos of Roomba in action. We experienced some issues when Roomba has to follow dark walls. In fact, the IR wall sensor seems not to detect these kind of surfaces, so the algorithm doesn't work properly then, but it will force Roomba to follow "blindly" the wall.
 The first video shows the general wall following algorithm.
@@ Line 304: / Line 307: @@
 {{#ev:youtube|v4Tz-pRCB-E}}
 *[http://www.youtube.com/watch?v=v4Tz-pRCB-E External link]
 In this second video, you can see the difference of behaviour, when Roomba follows a light surface (in the beginning) and a dark surface (after some seconds).
@@ Line 309: / Line 313: @@
 {{#ev:youtube|uBA3BA6rEHQ}}
 *[http://www.youtube.com/watch?v=uBA3BA6rEHQ External link]
 This last video shows another wall following, on a different floor material. In the end you can see another demonstration that dark surfaces are not detected by the wall sensor.

← Older revision		Revision as of 15:01, 3 September 2010
Line 297:		Line 297:

	Now you just have to press the Run button in the middle of the window, and Roomba will start to behave in the way we specified in the algorithm.		Now you just have to press the Run button in the middle of the window, and Roomba will start to behave in the way we specified in the algorithm.
		+
		+	We show three short videos of Roomba in action.
		+
		+	{{#ev:youtube\|v4Tz-pRCB-E}}
		+	*[http://www.youtube.com/watch?v=v4Tz-pRCB-E External link]
		+
		+	{{#ev:youtube\|gXyaannRO_8}}
		+	*[http://www.youtube.com/watch?v=gXyaannRO_8 External link]
		+
		+	{{#ev:youtube\|uBA3BA6rEHQ}}
		+	*[http://www.youtube.com/watch?v=uBA3BA6rEHQ External link]