Talk:Cheesoid

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Interaction Goals

Cheesoid is intended to be a fully autonomous mobile robot that interacts with people and objects in its environment. Human-Robot interaction is a massive subject but I intend to get some rudimentary (and comedic) speech and general input features in place as soon as possible. The environment interactions will develop as I learn more about sensing and mapping. Since the robot will live at Hackspace I have two basic goals for comedy value: -

  • interact with the fridge for cheese status
  • interact with the petrol pump for petrol status

So...

  • it needs to know where they are to go and talk to them
  • the status needs to be stored and needs to be set - Xino at each? Via IRC bot? Some web interface?
  • it need to be able to read the status from the fridge and the petrol pump - what sort of interface? IR remote control?

Petrol status

  • just a number!

Cheese status

  • many cheese types - each with use by date
  • Primula status is "in tube"

Human - Robot Interactions: speech

With the eeePC I have a very capable processor on board and I'm taking full advantage of that: -

  • using espeak for text to speech
  • using sphinx for speech recognition

Text to Speech with espeak

http://espeak.sourceforge.net/

The espeak voices aren't really robotic enough but can be made more so by creating a custom voice

speech recognition with sphinx

http://cmusphinx.sourceforge.net/wiki/tutorialconcepts

The sphinx packages 

p    --\ sphinx2-bin                                                                                                                    <none>     0.6-2.1
  Description: speech recognition utilities
    Sphinx 2 is a real-time, speaker-independent speech recognition system.

    This package contains examples and utilities that use Sphinx. It also includes a sample language model that is capable of recognizing simple commands
    like "go forward ten meters" and other commands one might use to tell a robot where to move.
  Priority: optional
  Section: universe/sound
  Maintainer: Ubuntu MOTU Developers <ubuntu-motu@lists.ubuntu.com>
  Compressed size: 129k
  Uncompressed size: 500k
  Source Package: sphinx2
  --\ Depends (3)
    --- libc6 (>= 2.4)
    --- libsphinx2g0 (>= 0.6) (UNSATISFIED)
    --- sphinx2-hmm-6k (UNSATISFIED)
  --\ Packages which depend on sphinx2-bin (0)
  --\ Versions of sphinx2-bin (1)
p    0.6-2.1

Good examples of the use of sphinx: -

Conversations and dialogue

In order to have a meaningful (preferably amusing and slightly uncanny) interaction with humans there needs to be a dialogue and some involvement of non-verbal communications: perhaps some shared experience, empathy, etc. We can fake a lot of things to push the human participant closer to the goal!

Mobility

  • motors
  • wheels
  • chassis
  • motor power
  • motor control circuitry
  • big battery

Drive motors: I now have my 12V 150RPM gearmotors from China


OK, motors tested with a two motor circuit...

Motor Test sketch (non-PWM) 

  1 int motor_left[] = {
  2   2, 3};
  3 int motor_right[] = {
  4   7, 8};
  5 const int ledPin = 13;      // LED 
  6 const int switchPin = 10;    // switch input
  7 const int enablePin = 9;    // H-bridge enable pin
  8 
  9 
 10 // ————————————————————————— Setup
 11 void setup() {
 12   Serial.begin(9600);
 13   pinMode(ledPin, OUTPUT);
 14   pinMode(switchPin, INPUT); 
 15   pinMode(enablePin, OUTPUT);
 16 
 17 
 18   // Setup motors
 19   int i;
 20   for(i = 0; i < 2; i++){
 21     pinMode(motor_left[i], OUTPUT);
 22     pinMode(motor_right[i], OUTPUT);
 23   }
 24   check_enable();
 25   // blink the LED 3 times. This should happen only once.
 26   // if you see the LED blink three times, it means that the module
 27   // reset itself,. probably because the motor caused a brownout
 28   // or a short.
 29   blink(ledPin, 3, 100);
 30 
 31 }
 32 
 33 
 34 void check_enable(){
 35   digitalWrite(enablePin, digitalRead(switchPin));
 36 }
 37 // ————————————————————————— Loop
 38 void loop() {
 39 
 40   drive_forward();
 41   delay(1000);
 42   motor_stop();
 43   Serial.println("1");
 44 
 45   drive_backward();
 46   delay(1000);
 47   motor_stop();
 48   Serial.println("2");
 49 
 50   turn_left();
 51   delay(1000);
 52   motor_stop();
 53   Serial.println("3");
 54 
 55   turn_right();
 56   delay(1000);
 57   motor_stop();
 58   Serial.println("4");
 59 
 60   motor_stop();
 61   delay(1000);
 62   motor_stop();
 63   Serial.println("5");
 64 }
 65 
 66 // ————————————————————————— Drive
 67 
 68 void motor_stop(){
 69   check_enable();
 70   digitalWrite(motor_left[0], LOW);
 71   digitalWrite(motor_left[1], LOW);
 72 
 73   digitalWrite(motor_right[0], LOW);
 74   digitalWrite(motor_right[1], LOW);
 75   delay(25);
 76 }
 77 
 78 void drive_forward(){
 79   check_enable();
 80   digitalWrite(motor_left[0], HIGH);
 81   digitalWrite(motor_left[1], LOW);
 82 
 83   digitalWrite(motor_right[0], HIGH);
 84   digitalWrite(motor_right[1], LOW);
 85 }
 86 
 87 void drive_backward(){
 88   check_enable();
 89   digitalWrite(motor_left[0], LOW);
 90   digitalWrite(motor_left[1], HIGH);
 91 
 92   digitalWrite(motor_right[0], LOW);
 93   digitalWrite(motor_right[1], HIGH);
 94 }
 95 
 96 void turn_left(){
 97   check_enable();
 98   digitalWrite(motor_left[0], LOW);
 99   digitalWrite(motor_left[1], HIGH);
100 
101   digitalWrite(motor_right[0], HIGH);
102   digitalWrite(motor_right[1], LOW);
103 }
104 
105 void turn_right(){
106   check_enable();
107   digitalWrite(motor_left[0], HIGH);
108   digitalWrite(motor_left[1], LOW);
109 
110   digitalWrite(motor_right[0], LOW);
111   digitalWrite(motor_right[1], HIGH);
112 }
113 
114 /*
115     blinks an LED
116  */
117 void blink(int whatPin, int howManyTimes, int milliSecs) {
118   int i = 0;
119   for ( i = 0; i < howManyTimes; i++) {
120     digitalWrite(whatPin, HIGH);
121     delay(milliSecs/2);
122     digitalWrite(whatPin, LOW);
123     delay(milliSecs/2);
124   }
125 }

This sketch is a munge of http://letsmakerobots.com/node/2074 and http://itp.nyu.edu/physcomp/Labs/DCMotorControl

MCU1 Motor Control

MCU1 will drive each motor via the SN754410 with three signals: Motor_Logic_1, Motor_Logic_2, and Motor_Enable (corresponding to the SN754410 pins). The Motor_Enable signals will be PWM thus using in total 2 PWM outputs plus 4 digital outputs. This allows a simple interface to the SN754410.

Control is via serial from the eeePC giving parameters of direction and speed for both motors at once. The motors can be put in hold with a stop command. The messages need to be quick for MCU1 to read and interpret but also easily human-readable. 

 D[L-dir][L-speed][R-dir][R-speed]
 
 direction = 1 char, 'F' = forwards, 'B' = backwards, 'X' = hold
 speed = 3 ASCII decimal digits in range 000 to 255 left zero padded

Examples: -

  • DF255F255 = full speed ahead
  • DF127F127 = half speed ahead
  • DF000F000 = freewheel?
  • DX000X000 = hold stop
  • DB255F255 = fast rotate left
  • DF255B255 = fast rotate right
  • DX000F255 = fast pivot left

The PWM will continue unless stopped so we should have a timeout on MCU1

The proposed Arduino code for interpreting the messages: - 

 (Get entire drive command or at least validate length)
 (validate fields and set any fault flags)
 // read out the pwm with quick math

 int pwm1, pwm2, 
 int motor1_c1, motor1_c2;
 int motor2_c1, motor2_c2;

 const int offset1 = 2;
 int pwm1 = 
    ((msg[offset1+0]-'0')*100)
  + ((msg[offset1+1]-'0')*10)
  + ((msg[offset1+2]-'0')*1);
  
 const int offset2 = 6;
 int pwm2 = 
    ((msg[offset2+0]-'0')*100)
  + ((msg[offset2+1]-'0')*10)
  + ((msg[offset2+2]-'0')*1);

 // the motor directions are rather arbitrary as they 
 // can be easily wired as necessary
 const int di1 = 1;
 if(msg[di1] == 'F'){
   motor1_c1 = HIGH;
   motor1_c2 = LOW;
 } else if(msg[di1] == 'B'){
   motor1_c1 = LOW;
   motor1_c2 = HIGH;
 } else { // default to hold
   motor1_c1 = LOW;
   motor1_c2 = LOW;
 }
 const int di2 = 5;
 if(msg[di2] == 'F'){
   motor1_c1 = HIGH;
   motor1_c2 = LOW;
 } else if(msg[di2] == 'B'){
   motor1_c1 = LOW;
   motor1_c2 = HIGH;
 } else { // default to hold
   motor1_c1 = LOW;
   motor1_c2 = LOW;
 }

DriveMotors(motor1_c1, motor1_c2, pwm1, motor2_c1, motor2_c2, pwm2);

Bodywork

  • battery regulation: http://letsmakerobots.com/node/3880
  • battery mounting - where?
    • chassis strong enough to carry those batteries? !!!!
    • aluminium cross bracing?
    • perhaps move to 2x 6V - keep it flexible
  • cylinder case mods
    • speakers in mouth plate/grill
    • side mount for MCU1 and support boards (temporary?)
    • top for beacon - keep on side for now
    • mounting of cylinder on chassis

Motor shaft couplings being the most annoying thing right now

  • I really need some well made couplings like these

Small hose clips may be the thing.

Brains

The current design makes use of a few processors: the small cheap eeePC 701 4G netbook and a couple of inexpensive (£7) Xino Arduino micros.

MCU1 and MCU2

Xino devices

MCU1 PIN usage summary table here on Google Docs

MCU1 software

  • TODO motor drive code and motor drive commands from PC

MCU2 software

  • drives LCD display
  • needs serial in from MCU1
  • status LED to panel

eeePC mods

Hardware and system mods to support "isolated usage".

  • soldered in an external power button cable
    • PWR button sub-assembly with safety keyswitch - mount on side panel
    • TODO LED in "Micro" and other nice illuminated buttons
    • Monostable/bistable startup flasher circuit for "Micro" switch?
  • "pizza box" container
    • power port extension
    • USB extension - USB hub - still powering MCU1 from USB - much drain?
#!/bin/sh
LID_STATE=`cat /proc/acpi/button/lid/LID/state | awk '{print $2 }'`

if [ $LID_STATE = "closed" ] ; then
#    /etc/acpi/suspend2ram.sh
        /bin/su user -c "/usr/bin/xrandr --output VGA --mode 800x600 --output LVDS --off"
fi
if [ $LID_STATE = "open" ] ; then
        /bin/su user -c "/usr/bin/xrandr --output LVDS --preferred --output VGA --off"
fi
exit 0

This is not enough: the eeePC will not power on with the lid closed so I had to disable the lid closed sensor by removing the magnet from screen section of the case 

# minimal brightness
echo 0 > /sys/devices/platform/eeepc/backlight/eeepc/brightness"
# screen off after 2 minutes
xset dpms 0 0 120

eeePC problems

  • unionfs inode depletion causing "No space left on device" but df shows plenty of space!
  • running out of space due to other errors ~/.Xsession-errors
  • firefox won't start - oh well!

eeePC Software

  • console read and process
  • speech module
    • speech commands from stdin
    • speech thread - busy flag and job queue management
  • motor module
    • motor control input from STDIN
  • sensor module
    • camera module - look at Java interaction with V4L or whatever is in use
    • mic input - and speech recognition
    • GUI interface port and GUI app

One annoyance is having to open the eeePC to find out its IP address to get back in via SSH. My proposed solution is to display the eeePC wlan IP address on the LCD on MCU2.

Get IP address to report on LCD <syntaxhighlight lang="java" line="GESHI_FANCY_LINE_NUMBERS" enclose="div"> package com.tecspy.util;

import java.net.Inet6Address; import java.net.InetAddress; import java.net.NetworkInterface; import java.net.SocketException; import java.net.UnknownHostException; import java.util.Enumeration;

import org.apache.log4j.BasicConfigurator; import org.apache.log4j.Logger;

public class NetUtils { 

   static Logger log = Logger.getLogger(NetUtils.class);
   
   public static String getIps() {
       
       StringBuilder buf = new StringBuilder();
       char div = '|';
       
       try {
           InetAddress localHost = InetAddress.getLocalHost();
           NetworkInterface ni = NetworkInterface.getByInetAddress(localHost);
           Enumeration<InetAddress> ia = ni.getInetAddresses();
           while (ia.hasMoreElements()) {
               InetAddress el = ia.nextElement();
               buf.append(div);
               if (el instanceof Inet6Address) {
                   buf.append("IPv6:");
               } else {
                   buf.append("IPv4:");
               }
               buf.append(" hostname:");
               buf.append(el.getCanonicalHostName());
               buf.append(" address:");
               buf.append(el.getHostAddress());
           }
       } catch (NullPointerException e) {
           log.error("Error: " + e.getMessage(), e);
       } catch (SocketException e) {
           log.error("Error: " + e.getMessage(), e);
       } catch (UnknownHostException e) {
           log.error("Error: " + e.getMessage(), e);
       }
       return buf.substring(1);
   }
   
   /**
    * @param args
    */
   public static void main(String[] args) {
       BasicConfigurator.configure();
       String ips = getIps();
       log.info(ips);
       
   }

}

Additional

Range Sensors

Rotary Encoders for wheels

  • an easily available "obsolete" ball type PS/2 mouse
  • Microsoft "Mouse Port Compatible Mouse 2.0A"
  • using the serial output from the mouse circuitry
  • encoder usage in daylight
  • mounting encoder wheel to axle
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