ROBODOC The manual and project report for his Robot Simulator, ME 435, 1990

                Introduction

     As a project requirement for ME435, I developed a
simulation software package to model the kinematics of an
assortment of robot arm designs.  The software package,
itself, was written in Borland's Turbo Pascal v.5.  It is
also menu driven and highly user friendly.
     There are three parts to the software package.  The
first is basically an exercise in three dimensional computer
graphics and forward kinematics.  The program allows the
user to input the link parameters for each of the robot's
joint into a supplied database.  The program then assembles
this information and display a graphical "stick figure"
representation of the robot in the x-y, x-z, and y-z planes
or a three dimension projection.  The variable link
parameters can then be modified in real time.  The second
part of the package allows the user to "teach" the robot arm
various positions.  This routine does not use inverse
kinematics but instead saves the robot arm's variable link
parameters to a datafile.  Later, the data can be read to
graphically move the arm.  The third part of the package
allows the user to define points in space which he/she
wishes the robot effecter to pass through.  The program then
generates the variable link parameters using inverse
kinematics.  Since non-general inverse kinematics consume
valuable computational time, the package uses inverse
kinematics on one manipulator design.
     The follow report discusses the simulation package in
detail as well as gives some insight to the theory behind

the software(see the appendix for an overview of the theory
involved in the simulation package).

          Table of Contents


A. Getting Started

      1.  Installing the Robot Simulator package
          on a hard disk
      2.  Running the Robot Simulator package

B.  Robot Simulator Tutorials

      1.  Play Robot Mode
      2.  Teach Robot Mode
      3.  Run Robot Mode
      4.  RRR Inverse Kinematics

C.  Database

D.  Screen Mode

E.  Help Screens

F.  File Manager

G.  Conclusions and Recommendations

A.  Getting Started

The Robot Simulator comes on a single disk in two files
called ROBO1.EXE and ROBOFILE.DBF.  Before you start using
the package, it is wise to make a backup copy of the
diskette and store the original in a safe place.  To run the
Robot Simulator from a hard disk, copy the files from the
floppy disk to the hard disk as described below.

1.  Installing the Robot Simulator on a hard disk

The Robot Simulator is not copy protected.  To install it on
your hard disk, just copy the files on the floppy to the
ROBOTSIM directory on your hard disk, as follows:

- To make drive C the default drive, type C: and press the
  <enter> key:

  C:  <enter>

  (If your hard disk is identified by a letter other than C,
  substitute your drive label for C in these instructions.)

- To make the ROBOTSIM directory on your hard disk, type:

  MD \ROBOTSIM  <enter>

- To change to the ROBOTSIM directory, type:

  CD \ROBOTSIM  <enter>

- Insert the Robot Simulation disk in drive A.  Then copy
all files from the disk to the ROBOTSIM directory:

  COPY A:\*.*  <enter>

You have now copied the Robot Simulation package to the
ROBOTSIM directory on your hard disk.

2.  Running the Robot Simulator

Before you run the Robot Simulator, you must change to the
disk and directory containing the Robot Simulator program.
Make sure you have installed the Robot Simulator in ROBOTSIM
directory, as described above.  Then, at the DOS prompt,
type these three commands:

  C:  <enter>

  CD \ROBOTSIM  <enter>

  ROBO1  <enter>

If the Robot Simulator can run on your system, you will see
a cover screen with a dial in the center.

B.  The Robot Simulator Tutorials


1.  Play with robot mode

The Play Robot Mode routine is used to try new manipulator
designs without creating a data file.  Before running any
robot simulation, the robot manipulator must be called from
the Robot Simulator's database.

The database is used to store the manipulators link
parameters and data file information.  The program
automatically uses the information in the manipulator's file
to name its data file.  To enter the Database, move the
arrow keys to select Database and then press the <enter>
key.

The Database screen shows all the information that can be
stored for a particular manipulator.  The arrow keys (up and
down) will move you to different input fields.  Proceed by
entering the robot name, degrees of freedom, and link
parameters for a given manipulator.

Please note that you must define at least a robot name to
define a Database file.

The Directory field is important since it defines where the
manipulator's data file will be stored.  For simplicity,
leave this field blank.  This will direct the program to
store the manipulator's data in the default directory, that
is the same directory (Disk) which contains the Robot
Simulator Program.

When you have finished entering the Database information,
press <F4> to "Save" the Database file.  The Robot Simulator
will store this manipulator in the ROBOFILE.DBF file in the
default directory to be accessed whenever needed.

Now type <F10> to "Use" this manipulator.  The Robot
Simulator will then take you back to the Main Menu screen.

Notice that the manipulator's name, degrees of freedom, file
path, and output screen type is displayed at the bottom of
the screen.

Now proceed to Play Robot.  Do this by moving the
highlighted bar to the appropriate choice and pressing
<enter>.

The Robot Simulator will show a stick figure representation
of the manipulator.  At the bottom of the screen, the x,y,z
coordinates of each of the manipulator's joints is
displayed.  Depending on the screen mode, the manipulator
will be shown in either three isometrics or a 3-D
projection.  The screen mode can be picked using the screen

mode option of the main menu.

The following is a list a functions available in play mode:

     F1 to F6 - Changes variable link parameter number
           1 to 6.  The direction is according to
           the toggle of F7.

     F7 - Toggles increase/decrease the variable link
          parameters.  Value shown on screen as either a
          up or down arrow.

     F8 - Toggles on/off of the x,y,z joint display.

The following are additional functions if the screen mode is
a 3-D projection:

     CTRL-R  - Changes roll according to F7
     CTRL-P  - Changes pitch according to F7
     CTRL-Y  - Changes yaw according to F7

You can exit the simulation by typing the <esc> key.

2.  Teach Robot Mode

The Teach Robot Mode routine is used to use a manipulator to
create a data file of different positions.  Before running
the robot simulation, the robot manipulator must be called
from the Robot Simulator's database.

The database is used to store the manipulators link
parameters and data file information.  The program
automatically uses the information in the manipulator's file
to name its data file.  To enter the Database, move the
arrow keys to select Database and then press the <enter>
key.

To call up an exiting manipulator file, enter the Database
by moving the highlighted bar to Database and pressing
<enter>.

Type in either the manipulator's name or degree of freedom
of your previous manipulator file.  Now, type <F8> to Find
the file.  The Robot Simulator will search through the
Database and list those which match any element of the
search file.  Note: read the tutorial for play mode to learn
how to define a robot manipulator.  Also, a search file with
* for a name will call up all of the manipulators files.

Select your file from those listed by moving the arrow keys
and pressing <enter>.  The file you have selected will
appear on the Database input screen.

Press <F10> to Use the File and return to the Main Menu
screen.

Again, notice that the manipulator's name, degrees of
freedom, file path, and output screen type is displayed at
the bottom of the screen.

Now proceed to Teach Robot.  Do this by moving the
highlighted bar to the appropriate choice and pressing
<enter>.

The Robot Simulator will prompt for a name of the
manipulator's run file.  The extension of all robot files is
.PTP which stands for point to point.  After entering the
run file's name and typing <enter> the Robot Simulator will
proceed to the display screen.

The Teach Robot Mode, like in the Play Robot Mode, will show
a stick figure representation of the manipulator.  At the
bottom of the screen, the x,y,z coordinates of each of the
manipulator's joints is displayed.  Depending on the screen
mode, the manipulator will be shown in either three
isometrics or a 3-D projection.  The screen mode can be
picked using the screen mode option of the main menu.

Like in the Play Robot Mode, the following is a list a
functions available in Teach Robot Mode:

     F1 to F6 - Changes variable link parameter number
           1 to 6.  The direction is according to
           the toggle of F7.

     F7 - Toggles increase/decrease the variable link
          parameters.  Value shown on screen as either a
          up or down arrow.

     F8 - Toggles on/off of the x,y,z joint display.

The following are additional functions if the screen mode is
a 3-D projection:

     CTRL-R  - Changes roll according to F7
     CTRL-P  - Changes pitch according to F7
     CTRL-Y  - Changes yaw according to F7

To save a particular manipulator position to the data file,

simply type the F9 key.  The Robot Simulator will save the
variable link parameters to the datafile.  This ASCII
datafile can be easily called up on a spreadsheet and
modified.  Note: the first line of the datafile specifies
the number of degrees of freedom for the manipulator.

3.  Run Robot Mode

Run Robot lets the manipulator read the datafile created in
a past Teach Robot Mode session.  If the manipulator's file
has already been defined (the manipulator's name will be
shown in the bottom of the main menu screen), you can
proceed directly into the Teach Robot Mode.

You can now proceed by moving the highlighted bar to Run
Robot Mode and pressing the <enter> key.  A pop-up menu will
list datafiles which match the defined manipulators degree
of freedom.  Scroll down to the datafile you wish to run and
type the <enter> key.

The Robot Simulator will now go to the manipulator display
screen.  Again, according to the screen mode, the
manipulator will be displayed in either three isometric
displays or in one 3-D projection.  Also, like the play
mode, F1-F8 and the CTRL keys function to move the
manipulator.

Typing the <enter> key will start the run mode simulation.
The Robot Simulator will read in the variable link
parameters and move the manipulator smoothly to the new
positions.  Again, type <esc> to return to the main menu.

4.  RRR Inverse Kinematics

The RRR Inverse Kinematics routine allows you to move the
end effector of a 3 degree of freedom revolute, 3 dimension
manipulator in the x, y, and z directions using inverse
kinematics.  The only robot file that this routine will work
for in the database is RRR3-D.  If this manipulator's file
has already been defined (the manipulator's name will be
shown in the bottom of the main menu screen), you can
proceed directly into the RRR Inv.Kin. routine.

The Robot Simulator will now go to the manipulator display
screen.  Again, according to the screen mode, the
manipulator will be displayed in either three isometric
displays or in one 3-D projection.  Also, like in the play
mode, F1-F8 and the CTRL keys still function to move the
manipulator.

Three additional keys are as follows:

     ALT-X  - Moves the end effector in the X direction.
     ALT-Y  - Moves the end effector in the Y direction.
     ALT-Z  - Moves the end effector in the Z direction.
    Note: the direction (+/-) depends on the toggle of F7.

Type the <esc> key to return to the main menu.

C.  Database

The Database keeps track of all the manipulator information.
You can enter the database routine by moving the highlighted
bar to Database and pressing <Enter>.

The first screen you see is the Data Input Screen.  This
screen is used for entering and storing a new manipulator's
record and then finding that record once it has been entered
into the Database.

The following briefly explains the Database function keys:

     F1 - Calls a help screen for your assistance.
     F2 - Clears the screen without saving anything.
     F4 - Saves the entered manipulator data to disk.
     F6 - Erases a manipulator's record from the Database
     F8 - Searches the Database for a manipulator's record.
     F10 - Designates a manipulator's record for use later.

To enter a new manipulator into the Database, simply enter
as many of the Database Fields as you wish.  The Database
Fields consists of the Robot's Name, Degrees of Freedom, the
link parameter alpha, a, d, and theta, and Datafile Path.
You must enter at least the Robot's name to create a file.
The Robot Simulator uses these fields to name the
manipulator's directory.

Once you have completed entering the new manipulator's
information, it can be stored by typing <F4>.  The Robot
Simulator then searches the database for records that have

both identical robot name and degrees of freedom as the new
record.  If there are no matches, the Robot Simulator will
store the new record in the Database.

To find any manipulator's record in the Database, simply
enter the robot's name or degrees of freedom and press <F8>.
The Robot Simulator will then search the Database for all
records that match those field(s) specified.  Matching
records are be displayed in a list.  From that list, you can
select which record to extract by moving the highlighted bar
and pressing <enter>.  The Robot Simulator then displays
that record on the Database Input Screen.  Note: a search
record with an asterisk (*) for the robot's name will
display all the records in the Database.

All of the simulations require that a manipulator is
specified.  To specify a manipulator, first find the
manipulator in the Database via <F8>.  Once the record is
extracted from the Database, type <F10>.  This will return
you to the Main Menu screen.  Note that the manipulator's
name, degrees of freedom, screen mode, and datafile path are
displayed in the bottom of the screen.

D.  Screen Mode

By selecting Screen Mode through the Main Menu, a new menu
will appear.  The Screen Mode procedure allows you to pick
either three isometric displays in the x-y, x-z, and y-z
planes or one 3-D projection.  The screen mode defaults to
the three projections.  To select the screen mode, move the
highlighted bar to your choice and type the <enter> key.
Note: the current screen mode is shown at the bottom of the
main menu screen.


E.  Help Screens

This routine offers a quick reminder of all the functions
available in the Robot Simulator.  Moving the highlighted
bar to Help Screens and typing <enter> will produce a second
menu.  To receive help on different modes, simply move the
bar to the desired topic and type <enter>.  To return to the
menu, type <enter> again.

F.  File Manager

File Manager is a system to manage your Robot Simulation as
well as any other file on your disks.  It allows you to
move, copy, or delete files and to create or remove
directories.  You can enter the File Manager from the main
menu by moving the highlighted bar to File Manager and
pressing <enter>.  The Robot Simulator's File Manager will
display the contents of the current directory.
     To understand how the File Manager works, you must be
somewhat familiar with directories and files.  If you are
already familiar with directories and files, you can skip
the next several paragraphs.

Each disk drive in your computer system is labeled by a
letter.  For example, floppy and micro disk drives are
usually labeled A or B whereas hard drives are usually
labeled C, D or E.  These labels are analogous to separate
filing cabinets.  As in filing cabinets, each disk may be
sub-divided.  To continue with the analogy, the directories
of the disks are the "drawers" of the filing cabinets.

Each directory can also be divided further into
subdirectories just as drawers can be divided with folders.
The process of subdividing directories can be continued many
times.  The following tree diagram shows how directories can
be used.

              Main Dir.(A,B,C,D or E drive)

       ROBOTSIM  Dir.(contains all manipulator files)

     ROBOT1      ROBOT2   (dir. for individual manipulators)

     TEST1.PTP   TRY1.PTP
     BLOCK.PTP   CONVEY.PTP      (indiv. run files)
     DRILL.PTP   PAINTSPR.PTP

     The current directory (usually the directory in which
ROBO1.EXE resides) is displayed when you first enter the
File Manager.  From this directory, it easy to move down
(further subdivided) or up in the directory tree.

To move down, simply move the highlighted bar to the
directory of your choice.  Directories are listed in dark
blue and have <DIR> under type.  Note: if you are running
the Robot Simulator directly from the Robot Simulator floppy
or micro disk or you have not run a session yet, there may
not be a sub-directory available to try.

To move up in the directory tree, move the highlighted bar
to the appropriate line with a period.  Note: if you are in
the main directory (File Cabinet), there will not be a line
with a period.

To move from one disk drive to another, you must use the
direct mode.  You can access the direct mode by simply
typing the letter of the drive followed by a colon(:) and

<enter> to move to that disk drive.  The letter that you
typed will appear in a box above the listed files.  This box
is the input for the direct mode.


The File Manager has the following commands available:

          F1 - Help
          F2 - Change Box
          F3 - Delete File
          F4 - Copy File
          F5 - Move File
          F6 - Make New Directory
          F7 - Remove Old Directory

F1 - This commands shows some of the sorting commands
available in the File Manager.  For example, <ALT>-N sorts
the files in the List Box by File or Directory name.

F2 - This command allows you to move from the List Box to
the Defined Box.  Typing <ESC> will return you back to the
list box.  (The Defined Box is discussed in section F3.)
The Change Box command is useful if many files have been
"defined" and you wish to "undefine" them.  To "undefine" a
file, move the highlighted bar to the file and press
<enter>.  This will remove the file from the Defined Box.


F3 - This command will delete all the files in the Defined
Box.  To put a file in the Defined Box simply move the
highlighted bar to the file and press <enter>.  The file
will now be "defined": ready to be Deleted, Copied, or
Moved.  To Delete the file, type <F3>.  The File Manager
will confirm your intentions to delete the file(s).  Note:
if you want to "undefine" a file, just move the highlighted
bar to the file (in either the Defined Box or the List Box)
and press <enter>.  The file will be removed from the
Defined Box.

F4 - This command will copy all the file(s) in the Defined
Box to a different disk or directory.  (Section F3 discusses
how to put a file in the Defined Box.)  To copy the file(s),
type <F4>.  The File Manager will ask where you would like
the file(s) copied.  To select the drive or directory,
simply move the arrow keys to the desired path.  The right
arrow key will move you down the directory tree whereas the
left arrow key will move you up the directory tree.  The up
or down will select the subdirectory.  When you have defined

the path, type <enter>.  The File Manager will copy the
file(s) to the path.

F5 - This command will move all the file(s) in the Defined
Box to a different disk or directory.  (Section F3 discusses
how to put a file in the Defined Box.)  To move the file(s),
type <F5>.  The File Manager will ask where you would like
the file(s) moved.  To select the drive or directory, simply
move the arrow keys to the desired path.  The right arrow
key will move you deeper into the directory tree whereas the
left arrow key will move you up out of the directory tree.
The up or down will select the subdirectory.  When you have
defined the path, type <enter>.  The File Manager will move
the file(s) to the path.

F6 - This command creates a new sub-directory in the current
directory.  When you type <F6>, the File Manager will ask
you for the new directory's name.  The directory can be up
to 8 characters long.  When you type <enter>, The File
Manager will automatically create a new sub-directory.

F7 - This command will delete an existing directory.  First,
go to the directory that has the directory you wish to
delete.  When you type <F7>, the File Manager will ask for
the directory's name.  After entering the name, press
<enter>.  The File Manager will delete that directory.

            Conclusions and Recommendations

     This project has given me a chance to learn first hand
the challenges of robot manipulator simulation.  These
challenges span from the projecting of the 3-D manipulator
into 2-D space to optimizing the calculations for the
graphical representation.  I am pleased with the
capabilities of the current software package even though
there is, of course, room for further enhancements.  For
example, I could have calculated joint velocities,
accelerations, and required torques especially since all of
the transformation matrices are stored in arrays.  These
calculations, however, are basically an extension of the
position analysis.
     The program can easily be augmented to become a useful
tool for both the simulations of existing and new robot
manipulators as well as a teaching aid in robotic
laboratories.  One long term but powerful enhancement would
be to include a general inverse kinematic routine.  I am
currently working on a method to have the computer try to
algebraically solve the close form solution to many general
manipulator designs.  I have also researched several
techniques to solve general six degree-of-freedom systems
using a combination of algebraic and numerical algorithms.
This combination appears to hold promise for future programs
but was slightly out of the scope of this project.
     I have enjoyed working on this project since it was
both extremely open-ended and challenging.  I would,
however, have liked to been able to discuss the project in

more detail at the beginning so as to shorten my learning
curve.

            *******************************************
            *                     *
            *   Robot Simulator software package      *
            *                     *
            *   Author: Andrew B. Conru               *
            *                     *
            *   Date: January 15, 1990                *
            *                     *
            *   No reproduction of this software or   *
            *   report may be copied an any medium    *
            *   without the written permission of     *
            *   the above stated author.              *
            *                     *
            *******************************************