First Lab Assignment: Moving the Robot

This first assignment is meant to show you
how to program the Nomad Robot using 'C'
and the Nserver program.

-------------------------------
Tasks:

1) >>>>  read the User's Manual  <<<

There is a copy in the lab (07 Moore) which should not
leave the lab! Copies are also available on-line
in http://vision.caltech.edu/jweber/cns286/homework.html

The other tasks are:
2) Run Nserver. 
3) Write a C program to move the robot.
4) Create a wanderer program: move the robot until it hits
   a wall. Back off, turn 90 degrees and proceed till bored.

-------------------------------

As you will read in the user's manual, the basic
philosophy in programming the robot is that you connect to a
server program (Nserver) which takes all robot commands
and either passes them to the real robot, or simulates
the response using a virtual software robot. In this way
you can test programs on the virtual robot from anywhere
on the net without worrying about breaking the robot. (The virtual
robot can also be made to move much faster than the real one).

You will need an account on one of the machines in the Mediterranean
cluster. There are Sun Sparcstations and linux PC's:

Sun machines
131.215.131.60 aegean 
131.215.70.40   adriatic

Linux machines
131.215.70.43   tacto tacto.caltech.edu
131.215.70.44   opto opto.caltech.edu
131.215.70.45   olfacto olfacto.caltech.edu
131.215.70.46   audito audito.caltech.edu
131.215.70.47   lingo lingo.caltech.edu

The robot itself is a linux machine called nomad.caltech.edu.

Connect to any of the machines and cd to:
(on Suns)
/home/weber/Nomad200/Nomad_host/host-2.6.6--sparc-sun-solaris2.4/server
(on linux)
/home/weber/Nomad200/Nomad_host/host-2.6.6--i486-linux1.1.18/server

Execute Nserver.

(If you are logged in remotely, you need to be running X windows
and have the DISPLAY variable set correctly. The Sun version may
complain about not finding libXm. Make sure /usr/dt/lib is in your load path via
the command:    setenv LD_LIBRARY_PATH /usr/openwin/lib:/usr/lib:/usr/dt/lib/.
Nserve must read the license.data file in order to run. )

Nserver is the graphical server which intercepts robot commands. You can
also steer the robot using the command line or joystick windows.

Load the map called test1.map. This is a rough approximation to 07 Moore!

Attached below is a program to get you started on programming the robot.
(Copy this program, edit it to reflect which computer is running the server,
and also get a copy of Nclient.h located in 
/home/weber/Nomad200/Nomad_host/host-2.6.6--i486-linux1.1.18/client/ in order
to compile the program).
The robot moves forward blindly first, then moves a given number of inches while 
continuously checking the bumbers for contact. Use it to write your own program to:

a) Move forward until a bumper detects something.
b) Back off from the obstacle a small amount.
c) Rotate 90 degrees.
d) goto step a)

If you always rotate in the same direction, this
program will explore the outer wall of any maze.

Run this program using the test1.map which contains a number of
things to crash into.

Notice that there will appear in the graphics window
a red robot and a blue one. One is the actual position of
the robot, the other is where the robot thinks it is by
reading the wheel position. Everytime you hit a wall,
the wheels slip and thus the robot thinks it moved when
it actually didn't. In time the integrated position will
become worse and worse.

If you can demonstrate to me that your program works,
we can try it on the real robot. Note that on the
real robot the bumbers are near the botton. If we hit
an object (like a table) that touches only the
top of the robot, the bumbers won't fire and the
robot will keep moving into the obstacle.

Any questions? First read the manual, then contact me.

------------------------------------------------------------------------------------
/* 
 * This program will connect to the robot, configure locomotion,
 * and move the robot using various commands.
 * It assumes that a server is running and connects to it
 *
 * To compile: gcc -o motiontest test1.c ~weber/Nomad200/Nomad_host/host-2.6.6--i486-linux1.1.
18/client/Nclient-linux.o   OR
 *             gcc -o motiontest test1.c ~weber/Nomad200/Nomad_host/host-2.6.6--sparc-sun-sola
ris2.4/client/Nclient-sparc.o -lsocket -lnsl
 *
 */
#include "Nclient.h"

#define ROBOT_ID 1 /* Currently, only robot #1 allowed */
#define SIMULATION 1

int wait_for_stop_or_bumper( int axis )
{
  /* wait for motion to begin */
  while( (State[axis] == 0) && (State[STATE_BUMPER] == 0))
    gs();
  if (State[STATE_BUMPER] !=0)
    return(0);

  /* wait for motion to end */
  while( (State[axis] != 0) && (State[STATE_BUMPER] == 0))
    gs();
  if (State[STATE_BUMPER] !=0)
    return(0);

  return(1);
}

int main()
{
  int dist=1;

  /* Connection */

  SERV_TCP_PORT = 7019;         /* Matches the number given in world.setup */

  /* >>>>>  NB! You must use the name of the machine that  <<<<< */
  /* >>>>>  is currently running Nserver!                  <<<<< */

  strcpy(SERVER_MACHINE_NAME, "olfacto"); /* The machine the server is running on */

  if (!connect_robot(ROBOT_ID)) 
  {
    printf("Connexion to robot failed\n");
    return(0);
  }

  if (SIMULATION)
    simulated_robot();          /* Commands will be sent to simulator */
  else
    real_robot;                 /* Commands will be sent to real robot (CAUTION!!) */

  conf_tm(2);                   /* Robot will stop if no command from the server in 2 seconds 
*/


  printf("         ************************************************************\n");
  printf("         * NOMADIC HOST SOFTWARE ENVIRONMENT - MOTION DEMONSTRATION *\n");
  printf("         ************************************************************\n\n\n");

  /* Initialize the robot */

  printf("Zeroing...\n");

  zr();                         /* Zero the robot */

  /* Initialize motion parameters */

  ac(200,300,300);              /* translation, steering, turret accelerations in .1in/s2, .1d
eg/s2 */
  sp(100,200,100);              /* translation, steering, turret speeds in .1in/s, .1deg/s */

  sleep(2);                     /* Wait (ws would do as well) */
  printf("Moving forward blindly ...\n");

  pr(100,0,0);          /* x, y, theta */
  ws(1,1,0,20);                  /* Wait for the motion to stop */

  printf("Enter a distance in inches: \n");
  scanf("%d",&dist);
  dist = dist*10;

  gs();                         /* Get state according to Smask */
  pr( dist, 0 , 0);
  if (!wait_for_stop_or_bumper( STATE_VEL_TRANS ) )
    {
      tk("OUCH!"); /* This robot talks !! */
      printf("Robot Hit a Wall!\n");
    }

  sleep(2);                     /* Wait (ws would do as well) */

  printf("End of demo, disconnecting ...\n");

  disconnect_robot( ROBOT_ID );

}