Project: The Self-Driving Car

We've recently reported on the Advanced Engineering I playground design project, but what exactly is keeping the younger group busy right now? If you pass by Room 401 most any afternoon, you'll find twelve freshmen and sophomores, six computers, three VEX robotics sets, two T.A.s, and one teacher very hard at work! The project? It's a little ambitious, but we are intending to design, build, and program three self-driving robot cars, in the manner of Google, Uber, Tesla, and a few others.

Just another typical day of class in the Providence Engineering Academy

The way of the future! But first a bit of background. Robotic cars fall into two broad categories: smart cars and smart roads. Smart car systems have all of the design and engineering and intelligence in the car itself, relying on GPS, lots of sensors, and careful programming. By contrast, smart road systems have some sort of marker built into the road itself to provide information to the car--one idea proposed in the past was to have magnets embedded into the road surface. While all companies are now putting all of their efforts into the "smart car" option, ours fall into the "smart road" category; we have a white line track on a dark background that shows the car where it needs to go. No white line means no navigation.

Left: the design brief and the plans for the roadway; right: the actual roadway,

newly constructed, mounted on an 8 foot by 8 foot plywood base

So what does it take to get this going? The number one resource is human intelligence; each of the three teams comprises four students, with distinct roles as follows:

• Team Leader: co-ordinate efforts, give attention wherever needed, be an all-around expert in everything, and keep a daily Captain's Log.
• Mechanical Engineer: primarily responsible for building the physical structure of the robot, mounting sensors, and attaching custom parts.
• Programmer: working on code that will navigate the robot around the course.
• CAD Specialist: design custom parts in a CAD program, and then print them out for use in actuality.

The beauty of this is that each member necessarily must work together with the others to achieve the outcome. The mechanical engineer needs input from the programmer as to where to place the sensors so that they work with the written code. The CAD specialist needs to also work with the mechanical engineer to decide what is most needed and where it should be placed. The team leader needs to choose just how to spread themselves each day to get the current priorities in order.

Ben (left) working on code; David (center) attaching his wheels to the frame

Samy, one of the mechanical engineers, putting together a frame for his

team's vehicle

Each team was allowed to choose between two types of steering design: rack and pinion, or a simpler design where the entire wheel and axle rotates around a central pivot. All three teams went for the rack and pinion, which is the same design found on modern cars. A single gear (the "pinion") rotates on a flat linear gear (the "rack"), which pushes it left or right, in turn causing the front wheels to point in either direction.

The custom CAD parts are another particularly exciting part of this project: the three CAD specialists are using the online platform Onshape to make pieces that are specific to their own robot. Just for fun, one team created a license plate with their team name, which is now proudly mounted on the front. Two teams are currently working on a box to hold a payload to be delivered along the route. The third team created a "shadow shield" to go underneath the vehicle and keep the line-sensing infrared sensors out of direct sunlight to make them more effective. The CAD specialists had to create bolt holes that match with the VEX robotics system, and they have infinite control over everything else.

One team's container design, intended to hold a small payload; a door is going

to be added to keep things secure until delivery

Another team's payload device is an open tray which flips up to release

upon command; note the square axle hole for connection to the motor

Both of the above designs are printed full size; so far, it looks like they will

be perfect!

The teams have another couple of weeks to finish this project, and they look to be on schedule for completion and demonstration.

Mr Meadth also decided that it would be fair for him to produce a proof of concept--can this really be done, after all? He used one of the spare middle school LEGO sets, which has an array of similar sensors and mechanical capability, but a very different coding language.

LEGO Mindstorms coding language--colourful blocks that snap together!

RobotC coding language, as used by the high school students--lines

and lines of colour-coded text

After a few hours of work, he came up with this smaller LEGO version, and it gets around the full track in about 18 seconds on its slowest, most cautious speed.

The LEGO robot car in action--note the three colour sensors in a bank on the

front; having three side-by-side allows for more sensitivity in response to the

car's exact position

Proof positive--it can be done! Upon completion, the robots will be demonstrated to the Providence community; we may go down to Lower Campus and show one of the elementary grades what we've done. Stay tuned.

Visit to UCSB Mechanical Engineering Department

On Monday of this week, sixteen Providence teachers and students took a trip out to UCSB, to visit the Mechanical Engineering department. Kirk Fields, Senior Development Engineer, met the group there and gave a tour of a few of the lab spaces.

The "clean room" was the first stop, and we noted that this is where Sarah Jane's father works to assemble his company's tiny lasers. We didn't see him through the window, but there were many interesting microscopic images of gecko feet!

The materials testing lab tied in well to what we have recently studied with our older group, Advanced Engineering I. Our students have been testing various materials in compression, carefully measuring the loads required to produce deflection, and deducing the modulus of elasticity--in layman's terms, a measure of how "springy" a substance is. This UCSB lab held dozens of industrial-grade machines to do similar experiments in compression, tension, fatigue, and so on.

Kirk (right) shows us the materials testing lab

Kirk was also able to show us a special research project, which involved a Perspex beam that "pushes back" when it a load is applied. Ordinarily, pushing on a beam would make it bend downwards, but this beam is equipped with sensors and motors that resist the action; this creates a beam with "infinite stiffness", so to speak.

The beam of "infinite stiffness" reacts and pushes back against applied load

We walked through some other spaces (including the wind tunnel), ending up in a robotics lab that housed an in-house competition much like what we do in our own middle school and high school classes. The college students design robots using a variety of motors, sensors, and LEGO structures; the robots ("rats") run around a walled-in elevated platform and collect "cheese".

One of the "rats" from last year is on display in the central case

The visit, though short, was well worthwhile. Jake, our senior, recently applied to this college and this department, so he was glad to meet some people and get a firsthand look. Mr Hurt, also present, graduated from this campus, and happily reminisced about times past.

All in all, a positive experience, and we're grateful to UCSB and Kirk Fields for allowing us the chance to come by!

Upcoming Event: MS Final Challenge!

In the Providence Middle School, fourteen 7th and 8th Graders are working busily on their capstone project for the semester: the Intro to Engineering Final Challenge! Every semester, the students in this elective are given a game-style challenge to complete, which involves designing, building, and programming a robot using LEGO Mindstorms EV3 sets.

This semester's challenge is being played out on a large elevated plywood platform, 8 ft by 8 ft. Mr Meadth spent a happy few hours putting this together in the science lab.

Each team of two students must create a robot that can sweep the platform clear of various pieces of coloured "debris"; imagine a small robot whose task is to permanently keep a rooftop helipad clear of windblown trash. Two robots are running in each round simultaneously, and whoever pushes off the most debris wins.

Special note: the pieces of "debris" we are using are the game pieces designed by Eva last year for her high school Educational Design project! Naturally, they are printed on our mod-T printers, which are still running strong (and now only $299 on their website!).

There are significant challenges associated with this project. How do you keep the robot from falling off the edge of the platform? How do you actually have the robot find the scattered debris? Does it run a blind search pattern, or does it try to use sensors to actively search? What kind of locomotive means does it use? Tracks or wheels or something else? What if it bumps into another robot?

Let's introduce our competitors this semester:

Isabela and Lily with their wheeled wonder--note the absence of rubber tires

on the front wheels to allow sideways slippage when turning

Christine and Sofi with their light and fast Pretzel Bot

James and Dylan with an imposing bulldozer--note the ultrasonic sensor on the

front to look for debris

Zach and Alan also went with a tracked design, and a large superstructure on

top for style points!

Ma.kaha and Cameron put their colour sensor way out in front to detect the edge

of the table--not falling off the table is critical to success!

Asher and Sam have an armoured design that looks just plain scary

Masato and Isaiah did some late redesign work to try to bring down their weight--

the robot with a lower weight gets the advantage of being placed first

The students will be presenting their completed designs to the rest of the class this Friday. The actual competition will take place in the Boys & Girls Club gymnasium on Monday and Tuesday at 1:00 during regular class time. Parents and friends are welcome, and it promises to be a lot of high energy fun!