Name: ANSWER KEY

Mars Exploration Program

Plew Elementary Robotics Program - October 2016

Lesson goals:

1. Learn about the EV3 brick, large motors, and TOUCH sensor.

2. Learn how to name a program in the software.

3. Learn how to write a program and execute it to allow the robot to explore Mars.

Introduction:

1. What is a robot? A ROBOT IS A PROGRAMMABLE DEVICE THAT CAN PERFORM TASKS AND INTERACT WITH ITS ENVIRONMENT.

2. What can robots be used for? MANUFACTURING, SURGERY, CLEANING.3. Why is it important to explore other planets? LOCATE FUTURE LIVING HABITATS FOR

HUMANS, LEARN ABOUT NEW CREATURES, INVESTIGATE GEOLOGICAL HISTORY, DISCOVER NEW PERIODIC ELEMENTS (MATERIALS). *SHOW NASA MARS ROVER.

4. If the robot was sent to explore Mars, what are the different types of terrain and obstacles that the

robot may encounter? DIRT, DUST, FROZEN WATER, DEEP TRENCHES, HILLS, ROCKS.

Equipment:

1. Where is the brick? ROBOT BRAIN/COMPUTER2. Which button turns the robot on? 23. Which button turns the robot off? 14. Which button stops the robot’s program? 1

5. Which input ports are used for sensors? 1-46. Which input ports are used for motors? A-D7. Where are the two large motors?

8. Where is the touch sensor?

9. What does the touch sensor do? DETECTS PRESSED, RELEASED, AND BUMPED states.10. What do you think the front bumper can be used for when exploring Mars (classroom)?

Program: FOR A 22-STUDENT CLASS, THERE IS ONE STEP FOR EACH STUDENT TO LEAD/READ.

1. One of the first steps of programming is writing a step-by-step “pseudo code” or an “algorithm”.

As a group, write a pseudo code for the robot to explore Mars using the touch sensor and front

bumper---include when to move forward or backward or turn, what the robot should do when it

“detects” an obstacle, etc.:

STEP 1: ROBOT MOVES FORWARD.STEP 2: ROBOT DETECTS AN OBSTACLE (FRONT BUMPER AND TOUCH SENSOR).STEP 3: ROBOT MOVES BACKWARD.STEP 4: ROBOT TURNS.STEP 5: ROBOT MOVES FORWARD AGAIN.[STEP 6: REPEAT STEPS 1-6 (LOOP). (WHEN SHOULD THE LOOP STOP? INFINITY?)]

2. To begin programming, turn-on the iPad, and open the LEGO MINDSTORMS application.

3. Select ‘New Program’.

4. Re-name a new program to “explorer”. SEE EXAMPLE PROGRAM.

5. Locate the green programming palette, drag the ‘Move Steering’ block to the programming

canvas, and attach it to the ‘Start’ block. Select File->Save.

6. Learn about how the robot moves with the Move Steering Block:

a. Locate the Port Selector. What is it used for?

THE PORT SELECTOR (UPPER RIGHT HAND CORNER) IDENTIFIES THE PORTS TO WHICH THE MOTORS ARE CONNECTED (EXAMPLE: B+C). NOTE: WHEN TWO PORTS ARE SELECTED, THE MOVE STEERING COMMAND ATTEMPTS TO SYNCHRONIZE THE PAIRED-MOTORS. IF ONE MOTOR SLOWS OR STOPS, THE OTHER WILL TRY TO MATCH. BOTH MOTORS CAN MOVE EITHER FORWARD (POSITIVE POWER) OR BACKWARD (NEGATIVE POWER). STEERING (TURNING) IS ACHIEVED BY APPLYING MORE POWER TO ONE OF THE TWO MOTORS.

b. Locate the Mode Selector. What is it used for?

THE MODE SELECTOR (LOWER LEFT HAND CORNER) ALLOWS THE STUDENT TO SELECT WHAT THEY WANT THE MOTOR TO DO. ‘X’ IS STOP. THE CIRCLE IS ‘ON’.

i. If the circle is ON, what are the options?

1. ON UNTIL TURNED OFF BY ANOTHER BLOCK OR THE END OF THE PROGRAM.

2. ON FOR A CERTAIN NUMBER OF SECONDS.3. ON FOR A CERTAIN NUMBER OF DEGREES.4. ON FOR A CERTAIN NUMBER OF ROTATIONS.

c. Locate the Steering Control. What is it used for?

THE STEERING CONTROL SETS THE POWER LEVEL APPLIED TO THE MOTORS. ZERO IS MOVE STRAIGHT, A POSITIVE NUMBER IS MORE POWER FOR C THAN B. A NEGATIVE NUMBER IS MORE POWER FOR B THAN C.

d. Locate the Power Control. What is it used for?

THE POWER CONTROL SETS THE POWER LEVEL APPLIED TO THE MOTORS. A POSTIVE NUMBER IS MOVE FORWARD. A NEGATIVE NUMBER IS MOVE BACKWARDS. NOTE: THIS IS NOT A SPEED CONTROL. THE POWER SETTING EFFECT ON SPEED IS NON-LINEAR AND A FUNCTION OF BATTERY LEVEL, OUTPUT LOAD, AND OPERATING CONDITIONS. SMALL AMOUNTS OF POWER MAY CAUSE THE ROBOT TO STALL.

e. Locate the Duration Control. What is it used for?

THE DURATION CONTROL SETS:i. ROTATION-THE NUMBER OF COMLETE ROTATIONS OF THE MOTOR.

USEFUL FOR LONGER DISTANCES.ii. DEGREES-THE NUMBER OF DEGREES THE MOTOR ROTATES. USEFUL

FOR MORE PRECISE MOVEMENTS.iii. SECONDS-HOW LONG THE MOTORS WILL TURN. USEFUL FOR QUICK,

APPROXIMATE DISTANCES. NOTE: USING TIME AS A DURATION CONTROL IS RISKY, SINCE CHANGES IN CONDITIONS OR BATTERY LEVEL WILL PRODUCE VARYING DISTANCES.

f. Locate the Brake or Coast Control. What is it used for?

THE BRAKE OR COAST CONTROL WILL EITHER LOCK THE WHEELS (BRAKE) UPON COMPLETION OF THE COMMAND, OR ALLOW THE MOTORS TO DRIFT TO A STOP (COAST). THE BRAKE SETTING CAUSES ADDITIONAL DRAIN ON THE BATTERY SINCE IT ACTIVELY ATTEMPS TO HOLD THE MOTOR OUTPUT IN PLACE.

7. Remove the Move Steering block from the programming canvas. HOLD FINGER ON BLOCK AND SWIPE DOWNWARD.

8. Locate the orange programming palette, drag the ‘Loop’ block to the programming canvas, and

attach it to the ‘Start’ block. Select File->Save. SEE EXAMPLE PROGRAM.9. Learn about Loop Block:

a. What is it used for? SOMETIMES THERE ARE ACTIONS THAT YOU WANT TO REPEAT. THE LOOP BLOCK ALLOWS YOU TO REPEAT THOSE ACTIONS UNTIL AN END CONDITION IS MET (OR BECOMES TRUE). THE DEFAULT IS INFINITY.

b. What are the options for stopping the loop? IF STUDENTS HAVE EXTRA TIME, THEY CAN EXPLORE THESE OPTIONS (COUNT, TIME).

10. Drag a ‘Move Steering’ block to the programming canvas inside the ‘Loop’ block. SEE EXAMPLE PROGRAM; THIS BLOCK IS TO MOVE IN A STRAIGHT LINE (UNTIL THE TOUCH SENSOR IS PRESSED).

11. Drag a ‘Wait’ block to the programming canvas, attach it to the right side of the ‘Move Steering’

block, inside the ‘Loop’ block. SEE EXAMPLE PROGRAM; THIS BLOCK IS TO WAIT UNTIL THE TOUCH SENSOR IS PRESSED.

12. Learn about the Wait Block:

a. What is it used for? THE WAIT BLOCK DETECTS (‘WAITS FOR’) WHEN THE TOUCH SENSOR IS PRESSED.

13. Drag a ‘Move Steering’ block to the programming canvas, attach it to the right side of the ‘Wait’

block, inside the ‘Loop’ block. SEE EXAMPLE PROGRAM; THIS BLOCK IS TO STOP THE MOTORS.

14. Drag a ‘Move Steering’ block to the programming canvas, attach it to the right side of the right-

most ‘Move Steering’ block, inside the ‘Loop’ block. SEE EXAMPLE PROGRAM; THIS BLOCK IS TO BACK UP.

15. Drag a ‘Move Steering’ block to the programming canvas, attach it to the right side of the right-

most ‘Move Steering’ block, inside the ‘Loop’ block. SEE EXAMPLE PROGRAM; THIS BLOCK IS TO TURN AROUND.

16. Implement the pseudo-code using action blocks (Move Steering, Wait) and a flow block (Loop).

Adjust the values on the blocks in your program. SEE EXAMPLE PROGRAM.17. Turn-on the robot. PUSH THE #2 BUTTON ON THE DIAGRAM ABOVE.18. Connect the robot to the iPad. SELECT THE ARROW AT THE TOP, RIGHT OF THE IPAD

SCREEN. SELECT CONNECT. SELECT THE ROBOT #. ENSURE THE BLUETOOTH/IPAD SELECTION IS CHECKED ON THE ROBOT.

19. Download the program to the robot. THE PROGRAM TITLE ‘EXPLORER’ WILL APPEAR ON THE ROBOT’S SCREEN IN THE FILE MANAGER.

20. Place the robot on the floor!!!!!!

21. Push the center button to execute/play the program. #2 ON THE DIAGRAM ABOVE. WHEN THE TOUCH SENSOR IS PRESSED, A NUMBER ‘1’ WILL APPEAR ON THE SENSOR STATUS (INSTEAD OF A ‘0’ FOR A NON-PRESSED STATE). TO GET TO THE DETAILED MOTOR/SENSOR PAGE, HOLD FINGER ON THE ROBOT NAME (“PLEW-6”).

22. When finished, delete the program from the brick’s screen. TAP 2 TIMES ON THE FILENAME ‘EXPLORER’ ON THE ROBOT SCREEN. SELECT DELETE.

23. Shut down the robot. SELECT THE #1 BUTTON ON THE DIAGRAM ABOVE. SELECT THE CHECK MARK ON THE ROBOT SCREEN.

24. Shut down the iPad. TOP RIGHT, HOLD DOWN TO COMPLETE A FULL SHUT-DOWN.

EXAMPLE PROGRAM:

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Homework: Learn more about the Mars Exploration Rovers at http://mars.nasa.gov/participate/funzone/

Background Info: Source < http://mars.nasa.gov/mer/overview/ >

NASA's twin robot geologists, the Mars Exploration Rovers, launched toward Mars on June 10 and July 7, 2003, in search of answers about the history of water on Mars. They landed on Mars January 3 and January 24 PST, 2004 (January 4 and January 25 UTC, 2004).

The Mars Exploration Rover mission is part of NASA's Mars Exploration Program, a long-term effort of robotic exploration of the red planet.

Primary among the mission's scientific goals is to search for and characterize a wide range of rocks and soils that hold clues to past water activity on Mars. The spacecraft are targeted to sites on opposite sides of Mars that appear to have been affected by liquid water in the past. The landing sites are at Gusev Crater, a possible former lake in a giant impact crater, and Meridiani Planum, where mineral deposits (hematite) suggest Mars had a wet past.

After the airbag-protected landing craft settled onto the surface and opened, the rovers rolled out to take panoramic images. These images give scientists the information they need to select promising geological targets that tell part of the story of water in Mars' past. Then, the rovers drive to those locations to perform on-site scientific investigations.

These are the primary science instruments carried by the rovers:

Panoramic Camera (Pancam): for determining the mineralogy, texture, and structure of the local terrain.

Miniature Thermal Emission Spectrometer (Mini-TES): for identifying promising rocks and soils for closer examination and for determining the processes that formed Martian rocks. The instrument is designed to look skyward to provide temperature profiles of the Martian atmosphere.

Mössbauer Spectrometer (MB): for close-up investigations of the mineralogy of iron-bearing rocks and soils.

Alpha Particle X-Ray Spectrometer (APXS): for close-up analysis of the abundances of elements that make up rocks and soils.

Magnets: for collecting magnetic dust particles. The Mössbauer Spectrometer and the Alpha Particle X-ray Spectrometer are designed to analyze the particles collected and help determine the ratio of magnetic particles to non-magnetic particles. They can also analyze the composition of magnetic minerals in airborne dust and rocks that have been ground by the Rock Abrasion Tool.

Microscopic Imager (MI): for obtaining close-up, high-resolution images of rocks and soils.

Rock Abrasion Tool (RAT): for removing dusty and weathered rock surfaces and exposing fresh material for examination by instruments onboard.

Before landing, the goal for each rover was to drive up to 40 meters (about 44 yards) in a single day, for a total of up to one 1 kilometer (about three-quarters of a mile). Both goals have been far exceeded! Moving from place to place, the rovers perform on-site geological investigations. Each rover is sort of the mechanical equivalent of a geologist walking the surface of Mars. The mast-mounted cameras are mounted 1.5 meters (5 feet) high and provide 360-degree, stereoscopic, humanlike views of the terrain. The robotic arm is capable of movement in much the same way as a human arm with an elbow and wrist, and can place instruments directly up against rock and soil targets of interest. In the mechanical "fist" of the arm is a microscopic camera that serves the same purpose as a geologist's handheld magnifying lens. The Rock Abrasion Tool serves the purpose of a geologist's rock hammer to expose the insides of rocks.

Images: Source < http://mars.nasa.gov/msl/multimedia/images/ >