Ultra-High Speed Autonomous Vehicle Introduction

Transcription

1 Ultra-High Speed Autonomous Vehicle Introduction According to Elon Musk to solve the problem of soul-destroying traffic, roads must go 3D, which means either flying cars or tunnels. Unlike flying cars, tunnels are weatherproof, out of sight and won't fall on your head. A large network of tunnels many levels deep would fix congestion in any city, no matter how large it grew (just keep adding levels). The key to making this work is increasing tunnelling speed and dropping costs by a factor of 10 or more this is the goal of Elon Musk s The Boring Company. Fast to dig, low cost tunnels would enable rapid transit across densely populated regions, enabling travel from Brisbane to Sydney in less than 1 hour 30 minutes. Musk has envisaged a future with ultra-high speed underground transportation system in which passengers are transported on autonomous pods traveling at 900+ kilometres per hour in a pressurised cabin. Hyperloop pods will transport between 8 and 16 passengers (mass transit), or a single passenger vehicle through these new tunnels. In Australia, our transport systems are becoming increasingly congested and are becoming more unsafe. The construction of Hyperloop tunnels that link capital cities may be the solution for our future transport needs. The design, construction, and testing of an ultra-high speed autonomous concept vehicle is an interesting process by which students will be engaged in applying science, technology, engineering and mathematics. In this activity, students will work in teams to design, construct, test and race a CO2 powered concept vehicle for a possible future ultra-high speed transport system. The Challenge is to see which team can engineer the best solution to the problem and which team can produce the fastest when raced down a 25-metre simulated tunnel. In the science component students will apply concepts and laws of motion and energy to the problem. Teams will conduct experiments, analyse data and draw conclusions from their findings. In the technology component, students will work in teams to design and construct their concept vehicles. They will also use technologies such as wind and smoke tunnels and data taking equipment such as Kookaberry units to test and improve their designs. In engineering, students will study the effects of forces such as thrust, drag, weight and gravity on the design. Symmetry and balance are critical to any aerodynamic design such as this concept vehicle. Mathematics is also essential in calculating speed and acceleration as a vehicle performance measure, and they will construct and interpret tables, charts and graphs of data related to boat design and performance. 1 P age

2 Ultra-High Speed Autonomous Vehicle Handout 1 - Design Brief Design Situation Internationally traditional transport systems are increasingly congested and are becoming more unsafe. Elon Musk has proposed a radical Hyperloop system to be constructed to elevate the problem of soul-destroying traffic congestion. A Hyperloop is a proposed mode of passenger and/or freight transportation comprising a sealed tunnel or system of tunnels through which a pod may travel free of air resistance or friction conveying people or objects at high speed while being very efficient. In this unit, you will learn how to design, build and test a prototype Ultra High Speed Autonomous vehicle. It s not a vehicle that you will ride in but a real one just the same. Designers for Tesla, Space X and NASA all had to start somewhere. They all started small, then they learned and progresses and moved on to bigger and better things. Possible design for the tube/ Hyperloop Transportation Technologies / 2 P age

3 Brief Design an Ultra High Speed Autonomous concept vehicle (to the specifications given) to travel a distance of 25m down a test track in the fastest time possible using the power provided by a single standard CO 2 cartridge. Design, Build and Test This is your chance to learn how it is done. Your group are going to come up with some super, fantastic ideas for your vehicle. Next, you will refine your idea. When everything is just right, you will make a prototype of how your concept vehicle will look and feel. After your group have worked out all the bugs you are going to construct a scale model of the concept vehicle. The final test will come when you race against others in your class and possible in your region. All concept vehicles will be compared for excellence in design, engineering, craftsmanship, efficiency, speed and time. Possible design for the Hyperloop Vehicle / Key Student Activities Key activities to be completed in this design brief include; Establish teams (3 to 5 students) Design, make and test a scale model Ultra-High Speed Autonomous concept vehicle made out of balsa Document the engineering design process into a presentation portfolio/poster Develop a trade booth display Produce marketing materials for concept design Develop a sales pitch presentation Compete in intra/inter school competition 3 P age

4 The Design Process To make it easy and fun you team should design and construct your concept vehicle in five easy steps. We call this the Design Process. This process can take a few minutes or several hours. It can be easy or somewhat difficult. Quite often this process is not as hard or complex as some people make it. As you go through each step you will be using the same methods used by designers at Tesla and NASA. They all start with drawings and ideas on paper. After the ideas have been refined they produce a prototype. Next, they will build a mock-up model that is actual size. The final stage is the production of a prototype vehicle. See design process in the Technology Activity lesson. Engineering for Good Series / Before completing this unit watch the YouTube clip on applying the Engineering Design Process to developing an impromptu Taco meal. 4 P age

5 ULTRA-HIGH SPEED AUTONOMOUS CONCEPT VEHICLE Problem Defined Due to the growth of our cities traditional transportation has caused wide spread congestion of our road networks which are becoming unsafe and inefficient in transporting people and goods between cities. Student Activities: Form into teams of 3-5 and assign roles to each team member. As a team describe the problem that needs to be solved? Construct your own teams design brief for the problem to be solved? Design Parameters/Limitations Design Parameters or limitations in the design process lets you know what you can and cannot do. The better you understand your limitations; the better you will be able to construct your concept vehicle. Parts for Prototype Concept Vehicle - Vehicle Body Block of balsa wood either F1inSchools Standard or CO2 Dragster Standard - Axles 2 metal axles - Bearings 2 plastic bearings - Screw Eyes 2 metal screw eyes (to keep vehicle tethered to the track) - Wheels 4 plastic wheels (Various choices) Know the Limitations Your concept vehicle must be made within certain limitations and specifications. To produce it properly you must learn what these requirements are before beginning the design process. On the next page is a list of production specifications for the Ultra-High Speed Autonomous Concept Vehicle. Your team will start with a block of balsa wood cut to the dimensions shown on the diagram and from the table. The concept vehicle cannot be any longer or wider than the measurement shown. The engine for the concept vehicle is a pressure-filled CO2 cartridge which fits into the back of the balsa block which is a limitation on your design. Make sure the cartridge can be fully inserted when the concept vehicle is finished. Follow all given specifications. 5 P age

6 Option 1: F1inSchools Style Blank 6 P age

7 Option 2: CO2 Dragster Style Blank 7 P age

8 Production Specifications - Basic Min Max Concept Vehicle Body Body length 170mm 305mm Body height at rear with wheels 50mm 75mm Body mass / weight with wheels and Kookaberry device 65g Body width at axles front & back 35mm 65mm Body width (including wheels) 105mm Track clearance 2mm Axles / Axle Holes / Wheelbase Number of axles 2 3 Rear axle hole from rear of vehicle 9mm 100mm Wheelbase 105mm 270mm Power Plant (CO2 Cartridge Hole) Power plant: depth of hole 50mm 52mm Power plant: housing thickness (around entire housing) 3mm Power plant: housing (diameter) Please use a 3/4 (19.5mm) Drill for 19.5mm 19.5mm best results. Power plant: lowest point of chamber diameter to race surface with wheels 26mm 36mm Screw Eyes Screw eye or eyelet inside diameter 5mm 8mm Screw eyes (2) distance apart at farthest point 155mm 270mm Wheels Wheels: front and rear diameter 30mm 40mm Wheels: width 2mm 24mm 8 P age

9 Student Activities: Identify other key constraints that will need to be considered in order for this problem to be solved? E.g. Time, budget, expertise, other materials, etc. Describe five different criteria that you will use to determine if your concept vehicle has been successful. E.g. Meets all basic Production Specifications, travels 25 meters in less than 2 seconds, etc. Research Solutions To determine the best solution to our problem it is often best to research what other solutions are already out there? The best way to do this is often via the internet. Brainstorming Ideas Brainstorming is a process for developing creative solutions. It usually involves the use of a white board, flip chart or butcher s paper to record ideas. This is crucial as Brainstorming needs to involve a team, which means that everyone must be able to see what`s happening and contribute to the discussion. Thumbnails Thumbnails are very little drawings on paper. They help you see how your concept vehicle is going to look. They can be drawings of the whole vehicle or just part of the vehicle such as the front end. They are called thumbnails because they are small. They are not detailed drawings, just quick sketches to give your team ideas. Thumbnails are often best when they include written annotations (notes) about your ideas. Student Activities: Research the following key concepts and ideas: - hyperloop transport systems - CO2 powered vehicles - F1inSchools program - Science of Speed In a group complete a brainstorming session on creative solutions for your concept vehicle, as well as ideas for team identity, trade display, pitch ideas, marketing etc. Record your finding from the session on a whiteboard, flipchart, butcher s paper, ipad, OneNote, etc. Produce a number of thumbnail sketches of possible design solutions for your concept vehicle. Annotate drawings with details of the design ideas and evaluate the positive and negative aspects of the design. 9 P age

10 Idea Generation Sketches Idea sketches are more detailed drawings of what your concept vehicle will be like. They are larger than thumbnail drawings and will show your design from different points of view. Teams should produce several alternative design solutions and evaluate them to determine the most promising solution. Final Concept Drawings Final concept drawings show the details of your vehicle and they are drawn to exact size. One of the drawing will include a side and top view so that the vehicle can be easily manufactured. You will also draw one on grid paper that will be used as a pattern to produce a prototype. These drawings should be exact and work as a blue print in order for the car to be manufactured. Student Activities: Teams to document a least two different concepts for their vehicle. Each vehicle needs to be evaluated and the most promising solution selected. Teams are to produce detail drawing for the construction of their concept vehicle. This will include a top and front view with overall dimensions and a scale drawing on graph paper to be transferred onto the balsa blank. A prototype is a pre-production model of a product, engineered for testing. Working Drawings The working drawing from select in the design process use a precise, 1:1 scale drawing to describe your vehicle and its features. Working drawings should have top and side, or profile, views. 10 P age

11 Student Activities: Part of the communication process is to draw your designs on graph paper as shown below. This will act as a template for your Autonomous Vehicle design which will assist in the construct of your final design. Directions on how to use graph paper: Lightly draw your vehicle's shape in the top and side view boxes below. Once you are happy with your design, darken in your design using good, hard lines drawn with drafting equipment. Finally, lightly shade in the design adding any possible paint schemes you may wish to add to your vehicle. Step in Construction of Your Prototype 1. Transferring Design to Body Blank Cut out the top and side (profile) views from a copy of your working drawing. Then, carefully trace the outline of the views onto the wood blank. Take Your Time Be sure to follow your patterns exactly. One major mistake can ruin the whole-body design or cause your concept vehicle to not meet specifications. Take pride in your work and try to make the best concept vehicle in the class. 11 P age

12 2. Drilling Axle Holes a) Transfer the axle hole locations onto the blank by using a sharp pointed tool or pen to puncture through the template and into the balsa blank. b) Lay the balsa blank on its side and drill 3mm axle pilot holes. The holes should be drilled perpendicular to the car s longitudinal axis in order for the car to roll freely and straight down the track. A drill press is highly recommended because it makes drilling perpendicular holes a cinch. C) These pilot holes can be enlarged to the size you need later. Note: Drill First: Axle holes in the body blank should be drilled before doing any shape cutting. Otherwise, it's difficult to drill straight. 3. Rough Shaping the Vehicle Body a) Use a scroll saw or get the teacher to use the band saw to roughly shape the balsa blank. Alternatively, you could use a coping saw to cut out the shape. i. Turn the blank on its side and cut out the profile view first. ii. Fit the waste pieces and working piece back together and secure them by wrapping two bands of masking tape around the assembly. iii. Set the blank assembly upright and cut out the top view. iv. Remove the masking tape and discard all the waste pieces. 2. Smooth the corners of your vehicle body. Use a wood rasp, files, or rough sandpaper (80 grit) to smooth the car to its basic rounded shape. 3. Periodically check your vehicle against the spec sheet (especially weight) to make sure the vehicle is still within tolerances. When weighing your car, put the wheels, axles, washers, screw eyes, and any other necessary hardware on the scale along with the body. Allow for the weight of paint coats too. If your design calls for a hollowed-out body, a high-speed rotary multi-tool works nicely. A variety of milling and sanding bits are helpful for making cavities in the car body. When using power tools to shape the car body, go slowly and cautiously. It s very easy to remove too much wood and ruin your car! 4. Fine Shaping the Vehicle Body At this point, the car has assumed its basic shape. Now you re at the stage that separates the really fine prototypes from the mediocre ones. Extra time and 12 P age

13 effort spent during the fine shaping, or pre-painting, stage have a huge payoff in the kerbside appeal of the final product. Use garnet paper to remove unwanted bumps and irregularities from the body. Use progressively finer grit paper as you go. For example, you might start with 80-grit paper (very course, removes a lot of material) and progress to 220-grit (fine paper for smoothing surfaces). Check your vehicle for symmetry, and sand the body as needed. Also, exposing your vehicle to bright light can help reveal imperfections that need attention. 5. Painting Your Vehicle Chassis As in the fine shaping stage, extra patience and effort put into the finishing stage can pay big dividends. Be aware that using several coats of paint can add weight to your car. a) Make up a handle and hanger. Cut a 500mm length of flat cut (5mm X 18mm approx) timber. Slightly sand off the edges at one end and drill a hole in the other. b) Insert the handle into the power plant housing of the vehicle body so that the timber jams slightly against the sides of the power plant hole. Enough to hold it on the handle when it is hanging down. This makes a very convenient handle for turning the body to paint it from all angles and you can hang it from a nail over a drip container while the paint dries. c) Apply undercoat and sand between coats. d) Use a spray can or airbrush to apply paint to the body. Spray light coats and wait several minutes between coats to allow the paint to dry. TIP Filler: To achieve a super smooth finish on porous balsa wood use a wood filler and sanding primer to fill problematic end-grain areas. 6. Final Assembly Mounting Wheels and Hardware Do not overlook the importance of this stage. A huge factor in race performance is how smoothly the vehicle rolls down the track. Some meticulously shaped cars have failed to finish races because of improperly installed hardware! a) Gather your hardware: two axles, bearings, wheels, and two screw eyes. Depending on the configuration of the car body, different hardware might be required. Shell cars (with internal wheels) often require wheel spacers and clips to affix the axles to the car body. b) Check your spec sheet for rules about wheels, axles and spacers. 13 P age

14 c) Check that the wheels have no plastic joining tabs on the rims. If they do, trim them off with a craft knife. d) Carefully mount the wheels and axles as dictated by your design. Be careful not to damage the fragile car body during installation. e) Roll test the vehicle on a smooth, horizontal surface. The vehicle should roll freely, and the wheels should spin without restriction. Make adjustments if necessary. f) Install the screw eyes on the underside of the vehicle body. Important: Plan the location of the screw eyes so the guideline does not rub against the vehicle body or wheels. TIP Just a Dab: A drop of epoxy glue can help solidify screw eyelet mountings in soft balsa. TIP Lube 4 Speed: Heard of dry powder graphite? It's a great lubricant for axles. Notes on construction assembled by I B MCKENZIE brucenancy@xtra.co.nz Student Activities: Teams to manufacture their vehicle designs to their plans. Depending upon the age group undertaking the activity some of the cutting out may be completed by a teacher or parent. Testing Testing is one of the most important aspects of the engineering design process. There are several different ways in which you can test the prototype. Incline plane: Test how well the vehicle rolls by placing it on an inclined plane. Race Track: If you have access to a race track and timer, you could do a few runs through the test track in full race conditions. Wind Tunnel: Place the vehicle in a wind tunnel to gain comparable results with other vehicles Smoke Tunnel: Place prototype in smoke tunnel to see the airflow around the vehicle. Evaluating 14 P age

15 Evaluate your design is an important part of the process and teams can use the results of testing to evaluate different aspects of the concept vehicles performance. From the criteria that you set yourself at the beginning of the engineering design process you need to determine if this project was successful. Remember that all cars will be compared for excellence in design, neatest idea, best craftsmanship and fastest racing time. Student Activities: Test the rolling resistance of the vehicle on an inclined plane, check for the following points. Does the vehicle roll in a straight path? Are the wheels on straight? Do the wheels spin freely? Were the washers mounted with the axles? Are the tires tight against the wheel hub? They should not spin on the hub. Try to find out what might be causing problems. Evaluate your concepts vehicles performance as a result of testing and from the criteria that you set yourself at the beginning of the engineering design process. Iterate After testing and evaluation has occurred iteration is the opportunity for the design team to make changes in order to improve the overall performance of the concept vehicle. Some common changes that can be made as a result of testing; Shape: Modify the shape of the vehicle to make it more streamline after smoke and wind tunnel testing. Wheel Alignment: If the vehicle veers drastically when performing a rolling resistance test then it is likely that the wheel alignment is out. Eyelet location: If the vehicle is slowed suddenly when performing a rolling resistance test then it could be that the eyelet is sticking out to far or is rubbing on the tether line, this can be relocated easily. Wheel Imperfection: If the vehicle bumps up and down when completing a rolling resistance test then you need to examine the wheels carefully and remove any imperfections with fine grit garnet paper. Axels: The type of material used for the axel can have a big impact. However, the biggest cause of problems is that the axel is not moving freely. This can be corrected by garnet paper of by drilling out the axel mounts. 15 P age

16 Wheels: Experiment with different types of wheel or event bearing to reduce friction and to improve overall performance. Surface Friction: Experiment with different lubricants such as dry powder graphite to improve performance. Student Activities: Based on the results of testing make changes to your original design to improve overall performance of your concept vehicle. Document any changes made and give reasons for the changes. If possible, conduct further testing to see if the improvements have resulted in better performance. If you were able to start back at the beginning what changes would you make to ensure that the design was successful? Communicate As part of the design process you will be asked to document the engineering design process. The best way to do this is through a design portfolio. The way you present your design portfolio can be varied and students are encouraged to find creative and innovative ways to document their design journey. This could be through a written portfolio, poster, expo display, video diary, one note portfolio or combination of different types. Your design portfolio should follow the engineering design process as communicated in this document which includes, Define, Identify, Brainstorm, Select, Prototype, Test, Iterate and Communicate. 16 P age