AME 469 Project 1: "Pick and Place" and "Teach and Repeat"

In manufacturing assembly operations, robots often perform what is called pick and place operations. As the name suggests, the robot picks up a part and places it somewhere else. For example, the robot may pick up a computer chip and insert it in the appropriate location on a circuit board. The way to program the robot to do this procedure is called teach and repeat. You teach the robot the required moves one time, and then it should be able to repeat the maneuver indefinitely. This project is an simple introduction into the programming required to make the Kawasaki JS5 (illustrated below) in the robotics lab do this. This project should be very easy, and is an illustration of the types of robotics concepts that are necessary for industrial application.

Project objectives:

After completing this project, each group will be able to

program proficiently in AS, the programming language for the JS5 robot in the undergraduate robotics lab; and,
use the "teach pendant" which allows direct, "joystick-like" control for the robot.

This lab description is intentionally incomplete. To get the robot to even move at all, at least one member of the group will have to consult with one of the course TA's to learn how to use the teach pendant to steer and program the robot.

Important:

At least one TA or the course instructor must be present whenever you are running the JS5.

The AS Programming Language:

You are encouraged to program the robot using any of the AS commands that you wish, but most likely you will use some of the following:

     jmove
     lmove
     here
     home

See the AS Programming reference manual (in the lab near the JS5) for details of each of these commands. Feel free to use other commands as well. In addition to the AS programming commands, you will need to use several interface commands via the teach pendant. These include:

     dir
     list
     prime
     ex

What you must do:

In the lab (357C Fitzpatrick) you will find the robot and a TA. There is a small "fork-lift" end effector attached to the end of the robot. Using that, you are going to program the robot to lift the small "pallets" from some starting position and place it in some final position.

The task is to program the robot to "swap" two pallets as illustrated in the following figure.

There are markings on the base of the robot that indicate the initial positions of the two pallets.

Outline: using the manual control pendant, you will be able to manually direct the robot through the steps necessary to swap the pallets. Note that when using the teach pendant to manually move the robot there are three different modes of operation. There are:

a joint mode, corresponding to dirctly controlling the individual joints of the robot;
a world mode, corresponding to translations in a "world" coordinate frame; and,
a tool mode, corresponding to translations and rotations in a "tool" coordinate frame attached to the end effector of the robot.

Using the

      here point_name

command, (where point_name is something like "p1" "p2" etc.) you will be able to name or define the various points, which then could be used in a program with the

      jmove point_name

command to have the robot automatically go through the sequence of steps necessary to swap the pallets. The program must start in the "home" position (straigt up).

Once you have defined the points, written the program and successfully swapped the pallets one time, you should see how many times in a row you can repeatedly swap the two pallets without interfering. Part of the grade depends upon how many times you can swap the pallets in a 5 minute period.

Use the commands

     prime

and

ex

to execute the program. Important: do not execute any programs without consulting the TA first.

Grading:

The total grade the project is 100 points. 80 points will be based upon the results presented in a report written consistent whit the report guidelines. The allocation for the final 20 points is based upon the following 2 considerations:

10 points will be given to the group that is able to swap the pallets the most number of times in a 5 minute period, 0 points will be given to the group that swaps them the least number of times and the score for all the other groups will be linearly interpolated between the two extremes. Important: the maximum speed setting in the program is set by the TA's. You may select slower speeds, but you are not allowed to select faster speeds. and the procedure must start and end in the HOME position.
10 points will be given to the group that writes the shortest program that is able to swap the pallets at least once, 0 points to the group with the longest program and the score for all the other groups will be linearly interpolated between the two extremes. Again, the robot must start in the HOME position. Note: this program may be different from the one designed to swap the pallets the most number of times.

Be sure to include in your report listings of all of your programs and the number of times you were able to swap the pallets in 5 minutes.

Return to the AME 469 Homepage.

Bill Goodwine (jgoodwin@nd.edu)
Last updated: January 19, 2001.