The Voyage of the Bathysphere

Transcription

1 The Voyage of the Bathysphere A Classroom Journey of Discovery MakerED Challenge August 14, 2016 THE VOYAGE OF THE BATHYSPHERE - DP 1

2 Introduction On August 15, 1934, William Beebe and Otis Barton set the world diving record by traveling to a depth of 3,028 feet below the surface of the ocean. Assisted by Gloria Hollister and Jocelyn Crane, Beebe and Barton made this journey inside a spherical vessel called the Bathysphere. In this lesson, you will use the Sphero robotic ball, the OrbBasic programming language, and a 3D-printed replica of the Bathysphere to simulate this world record event. Making Your Voyage in the Bathysphere Time to complete this lesson: 1.5 to 2.5 hours (exclusive of printing the 3D Bathysphere replica). Each student explorer will be given a copy of the 3D Bathysphere information plaque upon completion of this lesson. This plaque can then be used as a "talking point" for discussing this lesson with the explorer's family. How Deep is That? The voyage of the Bathysphere journeyed over one half mile deep. Another deep sea event that you might remember was twice as deep as the Bathysphere dive. On 20 April 2010, the Transocean Deepwater Horizon oil rig exploded in Mississippi Canyon 252 and began spewing roughly 210,000 gallons of crude oil into the ocean from its broken wellhead. The break in the wellhead was located over 5,000 feet below the ocean THE VOYAGE OF THE BATHYSPHERE - DP 2

3 surface. Robots were used for controlling this leak in a water temperature of 34F and an outside pressure of over 2,400 pounds per square inch (PSI). Objectives Students must demonstrate math skills for creating a rate of descent versus the depth attained by the robot. Guided by this mathematical knowledge they will write a computer program for driving the robot, determine the speed of the robot, and design methods for enabling the robot to "communicate" with them. Students will also develop a strong correlation between real world measurements and applications and designing the programming logic for guiding the robot to a specific depth. Audiences This lesson plan is structured for 7th and 8th grade students reinforcing fundamental concepts in mathematics, physics, computer science, history, and construction. Small groups of 2-3 students will be individually assigned primary elements for meeting these fundamental concepts. Collaboration between each of these student elements is vital for the successful completion of this lesson. Subjects This lesson addresses several cornerstones in a science, technology, engineering, and mathematics (STEM) curriculum, as well as basic Core knowledge subjects: Mathematics - determine the equation solving and geometry that will be used for successfully completing this lesson. Physics - derive accurate speed and distance measurements based on the mathematics and technology applied to this lesson. Computer Science - convert the mathematics and physics of this lesson into a viable computer program using variables, conditional statements, and program flow elements to interact with robotic sensors. History - examine the lives and lifestyles of the four main participants in the voyage of the Bathysphere; meet the faces behind the record. NOTE: all student explorers should participate on this activity. Technology - or, construction, includes the building, trimming, and testing of the 3D-printed Bathysphere replica. THE VOYAGE OF THE BATHYSPHERE - DP 3

4 Lesson/Activity At the conclusion of this lesson, students will be able to write a short OrbBasic program, dive the Bathysphere replica to a specific depth, and record the distance of this depth. They will also be able to collaborate with each other for meeting these goals by sharing information and examining different paths to the solution. First Let's Take a Look Into OrbBasic When you want to learn something new, there s no better place to start than with a "basic" introduction. This was true in the mid-1960s when John G. Kemeny and Thomas E. Kurtz created the Beginner s All-Purpose Symbolic Instruction Code (BASIC) at Dartmouth College. Contrary to what the BASIC acronym connotes, this is a powerful, general-purpose, high-level programming language. Roll BASIC up into a ball and you have OrbBasic. Just like its more conventional PC-based siblings, OrbBasic uses line numbers, program statements, variables, expressions, and a program interpreter. Executing at over 3000 lines per second, OrbBasic has the power to get Sphero moving. A typical OrbBasic program line looks like this: [line number] [one space] [statement] [or, expression] [or, comment] Inside this rather trivial generic program line example there are several syntax requirements and system constraints: 1. Some commands and statements are case sensitive (e.g., Vbatt and LEDC). 2. OrbBasic uses integers not decimals. 3. Negative integers must be declared as expressions (e.g., NO: X = -1; YES: X = 0-1). 4. The RAM program size is 1K bytes and the Flash program size is 4K. 5. The maximum level for nesting expressions (e.g., gosub) is 4 levels deep. 6. The maximum print string length is 32 bytes. Table 1 is a quick reference "cheat" sheet for figuring out OrbBasic statements, commands, variables, and operators. THE VOYAGE OF THE BATHYSPHERE - DP 4

5 Before you begin programming Sphero, follow these simple steps to setup your robot for receiving programming: 1. Download and install the OrbBasic app on your Bluetooth-enabled smart device. 2. Pair Sphero with OrbBasic and press the Create button (e.g., the circle with a plus symbol in it). 3. Enter a program name and press the New Program button. 4. Tap anywhere inside the blank screen and type your statements, commands, and expressions; don t forget to press the Return key at the end of each program line. 5. When you are finished running your program press the Done button. Here's a sample OrbBasic program for moving Sphero at 4-inches/second: 10 timera=0 20 goroll 0,7,1 30 if timera=10000 then print "10 seconds" else goto end This sample program can be used for detecting collisions with Sphero's sensor called an accelerometer (e.g., accelone): 10 goroll 0,100,1 20 if accelone>5000 then LEDC 6 else goto 10 Team Mathematics - 1. Determine an equation for measuring the depth traveled by your Bathysphere. 2. What factors could cause this measurement to become inaccurate? 3. What precautions can you take for ensuring the validity of your measurements? Team Physics - 1. Study the Sphero sensors. How can you use them for measuring the depth traveled by your Bathysphere? 2. How will you communicate with the robot? 3. Is Bluetooth connectivity effective underwater? THE VOYAGE OF THE BATHYSPHERE - DP 5

6 4. How will you know when your Bathysphere hits the bottom? 5. How much fishing line should be attached to your Bathysphere? Team Computer Science - 1. Convert the mathematics and physics teams products into a useable computer program written in OrbBasic. 2. How will you know if your program is running under water? 3. Sphero can only hold one program at a time. Make sure that your program has adequate space for implementing last minute changes to the code. Team Technology - 1. Assemble the Bathysphere. Glue the skid to the slots in the bottom, gently install Sphero inside the Bathysphere, and bolt the top onto this assembly with the fasteners. 2. If your Bathysphere will be used in water, how much weight must be attached to the skid for causing the vessel to sink? Make sure that your Bathysphere remains level as it descends. 3. Securely tie the fishing line to the connector on the top of your Bathysphere. Is your knot strong enough to lift your Bathysphere? 4. Attach the line to the fishing rod and reel. Preparation Material needed for completing this lesson: 3D printed files for the Bathysphere replica Sphero, SPRK, or SPRK+ robot OrbBasic App (Android and/or ios version) Large spool of break-resistant fishing line or filament (e.g., feet) (4) M4 screw bolt fasteners with matching nuts (NOTE: 6-32 fasteners can also be used) An assortment of fishing tackle weights or other water-resistant weights A fishing rod and reel Tape measure Stop watch THE VOYAGE OF THE BATHYSPHERE - DP 6

7 Various water-resistant pens or markers Plastic cement or glue A deep pool of water or a deep open stairwell References Some Web links for follow-up research into the voyage of the Bathysphere: "bathysphere". Encyclopædia Britannica. Encyclopædia Britannica Online. Encyclopædia Britannica Inc., ( The Official William Beebe Web Site ( bathysphere) THE VOYAGE OF THE BATHYSPHERE - DP 7

8 Table 1 OrbBasic Cheat Sheet Syntax: 10 LEDC 4 20 delay goroll 0,100,1 40 end Command Useage Range Note accelx accely accelz 10 X=accelY Reads accelerometer from to ctl 10 ctl=1 Control system ON=1 & OFF=0; dshake gyrox gyroy gyroz isconn pitch 10 if dshake>0 then goto if gyroz<0 print Sphero is rotating clockwise 10 if isconn>0 then LEDC 3 10 if pitch=0 then print Sphero is level Reads a double shake event Reads the rate of spin gyroscope in 0.1 degrees/second units Reads the state of Bluetooth connection Reads pitch from -90 to 90 roll 10 print pitch Reads roll from -180 to 180 Sbatt 10 if Sbatt=2 print Sphero battery is OK Reads battery state from 1 to 4 speed 10 X=speed Reads speed from 0 to 255 Vbatt 10 print Vbatt Read battery voltage in 100ths of volt xpos ypos 10 print xpos Reads x and y location of Sphero Approximately ±8Gs 1=double shake The rate ranges from to Pitch is the X axis Roll is the Y axis 1=charging 2=OK 3=low voltage 4=voltage critical, Sphero in sleep mode Reading of 750 equals 7.50V Scale is cm Uses locate statement THE VOYAGE OF THE BATHYSPHERE - DP 8

9 yaw 10 X=yaw Reads yaw from 0 to 356 Yaw is the Z axis Special Sphero Command: sqrt X*Y - used for simulating decimal values in integer math, where: X = the number for the square root operation Y = a scale multiplier, use for two decimal places Useage: This is a three-step process. 1. sqrt 90*10000 or sqrt which equals Convert the multiplier with square root of which equals Sphero divides the square root (e.g., ) by the multiplier conversion (e.g., 100) and returns 9.48 which is approximately the square root of 90 or NOTE: Use modulus (remainder) for obtaining the decimal value, like: 10 Z=sqrt 90* print sqrt 90 = Z/100. Z%100 Output: sqrt 90 = 9.48 Operators: All normal mathematical operators, plus:! - not equals % - modulus or remainder { - binary shift left } - binary shift right & - bitwise AND - bitwise OR Statement Useage Range Note data rstr read end 10 data 1,2,3 20 read X,Y 30 rstr 40 read Z 50 print X,Y,Z Output: if dshake>0 then end for next 10 for X=1 to next X -data values from 1 to 25 -returns read pointer to beginning of data set -puts data set value into variable Stops the program at that line number Loop through a number range set by for Data set can be overwritten on-the-fly Attempting to read the data set past the last value will result in error A step value is optional, like to count by 2s: 10 for X=1 to 10 step 2 THE VOYAGE OF THE BATHYSPHERE - DP 9

10 gosub return 10 gosub print Right here 40 return Branch program to a line number then return goto 10 goto 30 Branch program to a line number heading 10 heading 0 Assigns current yaw heading to value if then else 10 if X>30 then LEDC 1 or, 10 if dshake>0 then LEDC 1 else LEDC 6 else is optional locate 10 locate 0,0 Assigns the XY position print 10 print Hi Displays text on the Bluetooth-connected client device tron troff 10 tron Turns ON/OFF line tracing with output displayed on Bluetooth-connected device Use to recenter Sphero These commands & statements are supported in then clause: print, data, RGB, LEDC, read,rstr, goto, gosub, on X goto / gosub, return, delay, backled, tron, troff, goroll. Use with xpos & ypos for determining position A shorthand? character can be substituted for the print statement, like: 10 print Hi is the same as: 10? Hi Useful for program debugging System Commands: cmdroll - returns 1 for a new roll command transmission spdval - returns last speed from roll command hdval - returns last heading from roll command cmdrgb - returns 1 for a new RGB command transmission redval, grnval, bluval - returns the red, green, blue values from RGB command System Variables: Count down or count up in ms. timera timerb timerc THE VOYAGE OF THE BATHYSPHERE - DP 10

11 NOTE: This Cheat Sheet is based on the OrbBasic command structure from App version Not every command, statement, operator, and variable is represented on this Cheat Sheet. THE VOYAGE OF THE BATHYSPHERE - DP 11

12 The Voyage of the Bathysphere Rubric Name: Date: Criteria Challenge STEM - 25% Programming - 25% Technology - 25% History - 25% Successfully create a mathematical formula based on the physics dynamic for determining the depth of descent for your Bathysphere. Created a program written in OrbBasic for recording the depth of descent for your Bathysphere. Assembled a usable Bathysphere replica. Correlated the real lives and contributions of William Beebe, Otis Barton, Gloria Hollister, and Jocelyn Crane with the world record dive by the Bathysphere. Comments: Final Grade: THE VOYAGE OF THE BATHYSPHERE - DP 12

13 Student Worksheet The Voyage of the Bathysphere On August 15, 1934, William Beebe and Otis Barton set the world diving record by traveling to a depth of 3,028 feet below the surface of the ocean. Assisted by Gloria Hollister and Jocelyn Crane, Beebe and Barton made this journey inside a spherical vessel called the Bathysphere. In this lesson, you will use the Sphero robotic ball, the OrbBasic programming language, and a 3D-printed replica of the Bathysphere to simulate the world record event. You will form four teams. Each team will work independently on a challenge. The four team challenges will then be used for meeting the main lesson challenge: Determine the depth of descent for your Bathysphere. Team Mathematics - Your Challenge: Determine an equation for measuring the depth traveled by your Bathysphere. 1. What factors could cause this measurement to become inaccurate? 2. What precautions can you take for ensuring the validity of your measurements? Team Physics - Your Challenge: Study the Sphero sensors. How can you use them for measuring the depth traveled by your Bathysphere? 1. How will you communicate with the robot? 2. Is Bluetooth connectivity effective underwater? 3. How will you know when your Bathysphere hits the bottom? 4. How much fishing line should be attached to your Bathysphere? THE VOYAGE OF THE BATHYSPHERE - DP 13

14 Team Computer Science - Your Challenge: Convert the mathematics and physics teams products into a useable computer program written in OrbBasic. 1. How will you know if your program is running under water? 2. Sphero can only hold one program at a time. Make sure that your program has adequate space for implementing last minute changes to the code. Team Technology - Your Challenge: Assemble the Bathysphere. Glue the skid to the slots in the bottom, gently install Sphero inside the Bathysphere, and bolt the top onto this assembly with the fasteners. 1. If your Bathysphere will be used in water, how much weight must be attached to the skid for causing the vessel to sink? Make sure that your Bathysphere remains level as it descends. 2. Securely tie the fishing line to the connector on the top of your Bathysphere. Is your knot strong enough to lift your Bathysphere? 3. Attach the line to the fishing rod and reel. All student explorers must meet this History challenge, also. Examine the lives and lifestyles of the four main participants in the voyage of the Bathysphere; meet the faces behind the record. Here are a couple of Web links to get you started in your history challenge: bathysphere". Encyclopædia Britannica. Encyclopædia Britannica Online. Encyclopædia Britannica Inc., ( The Official William Beebe Web Site ( bathysphere) THE VOYAGE OF THE BATHYSPHERE - DP 14