CEG4158

Robix Familiarisation Guide

School of Information Technology and Engineering

University of Ottawa

Authors: P. Curtis, D. Townsend, P. Payeur

September 2006
 Overview
This guide will show the steps necessary to move the Robix robot in the chemist
formation, which is used in the CEG4158 course project, using the vender supplied
graphical user interface (GUI). After becoming familiar with the robot’s operation using
the GUI, an introduction to the scripting language illustrating the use of the commands
which will be used for the CEG4158 course project is provided. If at anytime you have a
problem, or think you have a problem, consult with your TA or the technician on duty.

Getting Things Started

To get ready to use the Robix robot, you must first connect it to the PC and power it up.
Please follow these steps:

Step 1 – Get the robot, data cable, and power supply from the TA on duty. Make sure
you always get the robot which is assigned to your group (the robot number
corresponds to your group number which is posted on the group registration sheet
in the lab). You will be asked for your student card in exchange. Don’t worry, you will
get back your student card when you give back the robot, data cable, and power supply to
the TA.
Step 2 – Connect the data cable from the robot to the PC parallel port
Step 3 – Plug the power supply into the robot
Step 4 – Plug the power supply into the electrical outlet
Step 5 – Log on to the PC

If you have any issues, at any time, please consult your TA, or the lab technician

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 Starting the Robix Rascal Software

The Robix Rascal software is a Windows GUI that allows you to control the robot. To
access it follow these directions (also see the Figure 1. below):

Step 1 – Click ‘Start’

Step 2 – Go to ‘Programs’
Step 3 – Go to the ‘Robix’ sub-menu
Step 4 – Click on ‘Rascal (0.2.23 Beta)’

Figure 1 - Screenshot of how to open the Robix Rascal software

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 Setting up the Robix Rascal Software

Once you click on the ‘Rascal (0.2.23 Beta)’, a message box illustrated in Figure 2. is
shown. READ this carefully, and then click ‘OK’.

Figure 2 - Robix Rascal Safety Screen

After clicking ‘OK’ you will be brought to the Configuration Screen shown in Figure 3.
To configure the software to recognise the robot you must first set up the robot profile.
To do this click on the ‘Auto-Configure Default Robot’ button circled in red in Figure 3.

Figure 3 - Robix Rascal Configuration Screen

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After clicking on the ‘Auto-Configure Default Robot’, you should end up with the results
as displayed in Figure 4.

Figure 4 - Robix Rascal Configuration Screen with Configured Robot

Now that the robot is configured, it is time to open up the robot console window. This
window allows you to control the robot’s joints. To do this click on the ‘Open Robot
Console’ button, which is circled in Figure 5. You should end up with the screen shown
in Figure 6.

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Figure 5 - Robix Rascal Configuration Screen with 'Open Robot Console' button circled

Figure 6 - Robix Rascal Console Screen

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 Familiarising Yourself with The Robix Rascal Control Window
The purpose of this section is to familiarise you with the controls of the robot. The robot
console window (Figure 7) has a menu bar, on top of a row of buttons, on top of a blue
console window, followed by a box which contains a list of properties with their
respective values for each servo motor.

Figure 7 - Robix Rascal Console Window

Each button is important, and their functions are as follows:

The ‘Servo Power: Off’ buttons. These buttons turn off all the
servo motors in the robot
The ‘Servo Power: On’ buttons. These buttons turn on all the
servo motors in the robot
This button you can safely ignore, as it is only used when
operating multiple robots at a time
The ‘Open Teach Window’ button. This button allows you to
control the robot using slide bars (also called teach mode), we
will get to this in the next section
The ‘Open Watch Window’ button. This button allows you to see
the current servo motor positions, and is called watch mode.
The ‘Run From Top’ button. This button allows you to run a
script in the blue console window starting from the first line

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 The ‘Pause’/’Un-Pause’ button. This button allows you to
pause/unpause a running script.
The ‘Halt’ button. This button allows you to stop a running script

The ‘Execute Line’ button. This button allows you to execute

current line of script which the cursor is positioned.
The ‘Execute Line and Step’ button. This button allows you to
execute current line of script which the cursor is positioned, and
then advances the cursor to the next line
The ‘Run From ## to ##’ button. This button allows you to
execute a range of lines within a script.

The blue console window is where you enter your scripting commands in order to control
the robot. Finally the property box displays the current position, maximum speed, the
acceleration and deceleration for each of the servo motors in the robot. The servo motor
number corresponds to the number on the decals placed on each motor on your robot.
Number 1 is the servo motor closest to the base of the robot, and number 6 is the farthest
away from the base of the robot.

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 Operating the Robot

Now that the robot is configured, and you are familiar with the controls, it is now time to
make it move! There are several ways to accomplish this, but the two main ways are to
use the sliders in the teach window, or to type scripting commands into the console. The
teach window will be shown first, followed by some scripting commands.

Click on the ‘Open Teach Window’ button, . The teach window will open up, as
shown in Figure 8.

Figure 8 - Robot Teach Window

The numbers below each of the slider bars correspond to the servo motor numbers. There
are 2 modes which you can move the robot: Absolute and Relative. Absolute means that
when you click on the ‘Add to Script’ button, that the script command that will be created
moves the robot to the exact position specified, regardless of its current position, while

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Relative means that the script command created will move to the location specified by an
amount relative to the previous position.

Now try moving the slide bars for each 6 robot joints and see what happens.

After you move the robot click on the ‘Add to Script’ button’, while using the Absolute
position mode. Notice the script command that appears in the blue console window. The
Absolute mode corresponds to the first line of script in Figure 9 ‘move 1 to -670’. The
word to in the script is representative of the Absolute mode.

Figure 9 - Sample Script in the Blue Console Window

Now try moving the slide bars to a different position and change the mode to Relative
position, then click the ‘Add to Script’ button. Notice the difference in the script lines.
Absolute positioning uses the word ‘to’ to describe where each servo motor is
commanded to move, while Relative positioning uses the word ‘by’ to describe by how
much each servo motor is commanded to move.

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Now change the mode back to absolute positioning then click the ‘Add to Script’ button.

Type in the following line into the blue console window between the 2nd and 3rd lines:
‘move all to 0;’. This line commands that all the servo motors are to move to their
respective zero positions. Figure 9 illustrates a script similar to what you should have.

Now click on the ‘Run from Top’ button. Notice that the first 2 lines move the robot to
the same position as the 4th line does, and corresponds to the position which you specified
in the teach window.

Try running the script and hitting the ‘Pause’/’Un-pause’ button as well as the ‘Halt’
button and observe what happens.

Also try clicking on the ‘Execute Line’ button multiple times while on the second line of
your script and observe what happens. Finally try the ‘Execute Line and Step’ button to
step through your script a line at a time.

Now click on one of the ‘Power Servos off’ buttons, and notice that the robot sags since
the servos are now turned off. To turn them back on, click on the ‘Power Servos On’
button.

When you are not using the robot, click on the ‘Power Servos off’ button to ensure that
the servo motors do not burn out. Note that all robots have slight differences. Then if
you burn a motor you will have to restart all you modelling work from the very
beginning. So, please take care of your machine !

To save your script click on ‘File’ in the menu bar, and then ‘Save’ or ‘Save as’. To open
a previous made script click on ‘File’ in the menu bar, and then ‘Open’. You can create
some scripts from a text editor like Notepad if you save it in a file following the format
script1.rbx.

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Now, you do not need to use the teach window to create the script or to operate the robot,
as you can code the script directly. Here is the list of commands and syntax which you
will need for your robotics project.

Command Operation
move <j> to <p>; Moves joint <j> to position <p>.
move <j1> to <p1>, <j2> to <p2>; Moves joint <j1> to position <p1> while at the
same time moving joint <j2> to position <p2>.
move <j> by <d>; Moves joint <j> by <d> units.
move <j1> by <d1>, <j2> by <d2>; Moves joint <j1> by <d1> units while at the same
time moving joint <j2> by <d2> units.
move <j1> by <d1>, <j2> to <p2>; Moves joint <j1> by <d1> units while at the same
time moving joint <j2> to position <p2>.
move all to <p>; Moves all joints to position <p>.
move all by <d>; Moves all joints by <d> units.
move <j1> to <p1>, <j2> to <p2>, Moves the joints <j1>, <j2>, …, <jn> to the
…, <jn> to <pn>; corresponding positions <p1>, <p2>, …, <pn>
simultaneously.

Note that the command to move the robot is ‘move’ and that is followed by a list of joint
movements separated by commas. The line is terminated by the semi-colon. A joint
movement is specified by a joint number (1-6), followed by the movement type (‘to’ for
absolute positioning, and ‘by’ for relative positioning), followed by the position or
distance to be moved.

Read carefully!!!!!

The default minimum and maximum positions are -1400 and 1400, and the exact angles
which these correspond to are different for every joint and every robot. The units which
the servo motors use correspond to the steps of the internal encoders mounted in each
actuator, from which a linear relationship with respect to the actual angle can be
determined. To approximate this relationship, first find the angles which correspond to
the minimum and maximum servo motor positions, and then solve the equation,
Y = mX + b , for m and b, where Y is the angle, and X is the servo motor position.

e.g. Say servo motor 4 has the following relationship: (-1400, -11°) and (1400, 39°),
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then the relationship would be: Y = X + 14 .
2800

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Now determine this relationship for all of the joints for your robot. Record this as you
will require this conversion later on during the course project.

Try a few different self written scripts and step through them to get comfortable with the
scripting language and the Robix Rascal console. You may want to try out some
different values for each joint of the robot in order to asses the range of motions that the
robot can perform.

Experiment on a Simple Pick-and-Place Operation

Use the Robix script language to drive the gripper of your robot toward a small object
(like an erasor) that you will previously place on the table within the workspace of the
manipulator. Use a ruler to estimate the position of the object on the table with respect to
the base of the robot and try to figure out (approximately) a configuration of the robot
(select a proper set of angles for joints 1 to 5) that will bring the gripper just above the
object. You might need to iterate quite a few times before you succeed to bring the
effector in a correct position and orientation without bumping into your object.
Once you will have reached the object, close the gripper (refer to the Robix manual as
how to do it) and grab the object. Now lift up the object and move it up to another
position where you will release it. Observe how complex this simple task can be when it
is performed with a robot.

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 Putting The Robot Away

Now that you know how to control the robot, and are ready to put the robot away for
another day, please carefully follow this list of instructions:

Step 1 – Save any scripts or data that you want to keep to your H: drive.
Step 2 – Close all of the Robix Rascal Windows – this can be accomplished by clicking
on the x in the top right hand corner of the various windows
Step 3 – Unplug the robot power cable from the power strip outlet
Step 4 – Disconnect the robot data cable from the back of the computer.
Step 5 – Unplug the robot power cable from the robot.
Step 6 – Unplug the robot data cable from the robot.
Step 7 – Log off of the lab computer.
Step 8 –Hand back the robot, data cable, and power supply to your TA and get your
student card returned to you.

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