Robotic Arm: A Production/Manufacturing Investigation

What is a robot?

Controlling a robot involves programming a sequence of steps that can be repeated. Sensors can be used to provide feedback on the robot’s position so the steps are repeated reliably and safely.

Problem Statement

Homemade Ice Cream Company packages ice cream for delivery to local stores and for shipment to out of town stores. Local packages have an ice cream decal on them. Out of town packages are black with an arrow on them. Both types of packages come down the chute at the end of the packing line and must be placed into the appropriate shipping bins. The packages are bulky and difficult to move by hand so they would like you to design and build a robot to pick up each ice cream package and place it into the appropriate shipping bin.

Design Briefs

Design and build a robotic arm that includes:

A robot hand for gripping and releasing a package.

A robot arm for moving the hand into the appropriate position.

A chute area for picking up the packages

Two areas for dropping the sorted packages: one for the local packages and another for the out of town packages.

Build the model shown in the building instructions 9701-7

Attach the following outputs and inputs as shown in the instructions.

Robot Arm Motor	Port A
Robot Hand Motor	Port B
Angle Sensor	Port 5	Required for a B
Light Sensor	Port 6	Attach the light sensor to detect which package is in the chute and deliver to the correct bin. Required for an A+

This addresses the main design criteria to receive a C for your robotic arm project.

• Make sure the robot arm motor is attached to Port A, the robot hand motor is attached to Port B and the Angle sensor is attached to Port 5 on the Control Lab Block.
• Control the robotic arm and hand according to its position relative to the chute and the drop off bins:

· Place the lead for Motor B on the On button connect it long enough to open the hand.

· Place the lead for Motor A on the On button connect it long enough to move the robot arm to the chute.

· Place the lead for Motor B on the On button connect it long enough to close the hand and grasp the package.

· Place the lead for Motor A on the On button connect it long enough to move the robot arm to the proper bin (close or far).

· Place the lead for Motor B on the On button connect it long enough to open the hand and release the package into the correct bin.

· Repeat the process for all three packages.

This addresses the main design criteria to receive a B for your robotic arm project.

For this design you must find out:

· How much time does the hand take to open and close? Use a simple program to test the robot hand motor which is attached to output port B.

· How much motor overrun is necessary for the hand to clamp a package securely? Attach the output port B lead to the On button to position the hand in the open position over the chute. The robot should be able to grasp the package as it closes.

Write a simple program to turn on motor B. Determine how much time is needed to grasp the package. Use this number when writing a program to close the hand motor to pick up the packages. Write another program to open the hand motor and release the package.

Use the text tool and the robolab program to create a control panel page that has manual arm and hand controls that are run by an operator. You should have 7 different programs: one to open the hand, a second for moving the arm to the chute, a third one for closing the hand, a fourth that delivers the package to the close bin, a fifth that moves the arm back to the chute from the close bin, a sixth to move to the far bin and a seventh to move from the far bin back to the chute. The operator checks the position of the arm. He or she is responsible for opening the hand, rotating the arm until it is above the chute, closing the hand to grasp the package. Taking the grasp package to the correct bin and opening the hand to release the package into the correct bin.

The Program Page should include:

• 7 different programs to control the robotic arm.
• Text boxes for the heading and explanatory information.

This addresses the main design criteria to receive an A for your robotic arm project.

For this design you are using the rotation sensor, you must find out:

• At which rotational count must the robot stop to pick up a package? Reset the rotation sensor to zero when it is in the correct position to pick up a package at the end of the chute.
• At which rotational count must the robot stop to drop a local package? Create a simple program to turn on motor A to position the robot over the local packages bin. Write down the value of the rotation sensor in view window. This is the number to use when writing a procedure for the robotic arm to move to the “local package” bin.
• At which rotational count must the robot stop to drop a distant package? Create a simple program to turn on motor A to position the robot over the distant packages bin. Write down the value of the rotation sensor in view window. This is the number to use when writing a procedure for the robotic arm to move to the “distant package” bin.
• At which point should the hand be opened? And closed?

Use the rotation sensor for feedback on the arm position to create an automatic system that closes the hand on the first package in the chute move the arm to the local bin drops the package off and returns to the chute for the next package. The next package is delivered to the distant bin. The process is repeated delivering packages in the same manner alternating delivery from local to distant bins. Once the program is activated, the procedure runs forever until the stop button is pressed which turns off the automatic delivery procedure.

The Program Page should include:

• A program that starts and stops the automatic control procedure.
• Sub-procedures that control the opening and closing of the hand.
• Sub-procedures that control the movement of the robotic arm according to the delivery of the package from the chute.
• Text boxes for the heading and explanatory information.

This addresses the main design criteria to receive an A+ for your robotic arm project.

The light sensor is used for feedback on which package, local or distant is in the chute and to where it needs to be delivered. The light sensor checks the chute to see which package is next in line to be delivered. According to the light sensor reading the package is picked up from the chute, the arm is moved to the correct bin dropped off. The arm then returns to the chute for the next package using the light sensor to determine which bin to deliver to. The process is repeated delivering packages in the same manner to either the local to distant bins. Once the program is activated, the procedure runs forever until the stop button is pressed which turns off the automatic delivery procedure.

The Control Panel Page should include:

• A program that starts and stops the automatic control procedure on the procedures page.
• Sub procedures that control the opening and closing of the hand.
• sub-procedures that control the movement of the robotic arm according to the delivery of the package from the chute.
• sub-procedures that use the light sensor to control the opening and closing of the hand and the arm movement.
• Text boxes for the heading and explanatory information.

Teacher Notes for Procedures: