Bench mechanic idea 01

Circular into rectilinear horizontally will allow the support stick to push the bottom end of the bench's back. This way we can have flatter gear box underneath the bench, which will make the installation and maintenance much easier.

Searching for metal detector

The trashcan operates by using a scale and metal detector. The assumption is if the correct relation between metal and weight is detected we can assume that it is a 12 oz can.

I've been hunting around for a good strategy for metal detection. There are a few do it yourself strategies, the best of which is this one at instructables. There are a whole slew of other metal detector schematics at discovercircuits. My understanding is that the bfo metal detector operates by having two oscillators that each have the same frequency. When metal is present between the two oscillators it will vary the frequency. I think it is the same principle in this video below.

The concern I have with this approach is that it appears to provide feedback on whether metal is proximate. It definitely does not provide precise measurements for the amount of metal detected. Therefore I think i need to get a profesional metal detector that can provide more information on what amount and perhaps type of metal is nearby. This brings us into the realm of those treasure seekers. There is a large group of treasure hunting enthusiasts who use these devices to find lost jewelry and ancient coins. Their high end devices can pin point distance from the surface, distinguish metal from minerals in rocks, and provide on board diagnostics. Not exactly what I need. There are other metal detector systems as well, for instance metal detectors are used poultry farms to make sure there aren't any metal bits in the birds. Also, metal detectors are used by various security sensors at night clubs and airports.

It appears that at this point the best solution is to buy one of the low end professional units (around $50) and get a better idea of exactly how well it can work. I can test it around the pressure sensor and then try to dissassemble it and reassemble into the shape needed for the Trash can. Time to start hunting through craigslist and ebay!

Too Smart City Placement Top View

The furthest length of the distance between two furniture should be more than 5 feet and less than 10 feet.

Researching Sonar Sensors

The Too Smart City Sign,  in its current,  and likely final interactive structure, requires that it knows when users are standing near it,  and at what direction and distance from the sign structure.

Key challenges include:

• Users having variable height
• More than one user being at the location
• Non-user objects
• Extending range to entire 360 degrees  around sign
• Determining distance to a high precision.

First was to figure out what type of sensor would work.  I'd used sonar sensors before, and know that IR sensors are used in security systems for very cheap.  There are ofcourse binary solutions, like lasers or light beams that detect when an obstruction is present.

I found this very helpful post at Society of Robots on IR vs Ultrasonic.  As I'd suspected, sunlight will have too large of an impact in an outdoors park to allow IR to be a possibility for the SIGN.  It should be a good solution for the trash can though, since it will contained within the dark recesses of the bin.

First Idea:

In this version there would be a series of 8 sensors that are embedded in the mid-section of the body.Each sensor would tell user distance, and the sensor ID would be used to determine which direction the user was in.

Key problem with this is that it is overkill if we are using sonar sensors. Sonar sensors read with a beam, where the sensor area is first thin, then grows in width to the extension of its range.

This beam shape enables us to have an overlap between two sensors, therefore giving us twice as many directions, and halving the required number of sensors. The below image is a rough depiction:

The concern with this system is that if there are two users standing equidistant from the pole in two of the locations (as depicted by the orange dots in 5 and 7) it would be the same as if a single user were standing in zone 6.

Four sensors are still rather pricey; the sensors we are currently considering are MaxBotix and are $100 each.

SO ... perhaps a better idea is to use a single sensor and a stepper motor with a narrow field. The motor would turn around as fast as it can while still registering accurate sonar readings at each point.  There are some big problems with this approach.  The motor rotating constantly for 3 months outside may have problems, at least with continually providing accurate position.  Secondly, the cables connecting to the sonars sensor will need to handle turning repeatedly back and forth as the motor rotates 360 degrees in alternating directions.

This picture roughly depicts the idea - where it can determine different distances at different times.  This would then need some algorithm to analyze fluxtuations in distance over time.

TSC Installation Location Wish List Map

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Too Smart Bench Alternate Lego Prototype v.1

1. The Too Smart City Bench appears as a normal public bench.
2. Freddy seats upon the bench.
3. After the allotted time, Freddy is ejected from the bench.
4. Gears hidden underneath the bench rotate a shaft.
5. As the gears rotate the shaft, the rear base of the bench platform is lifted 18", raising the backside of the bench and ejecting Freddy.

Too Smart Bench Lego Prototype v.1

1. Freddy is seated upon the Too Smart Bench
2. Gears within the bench rotate the belt, shifting the planks that Freddy is seated on.
3. As the bench rotates, Freddy loses his balance and is removed from his seating position.

Too Smart Trash Can Lego Prototype v.1

1. Freddy puts the non-recyclable trash into the trash can.

2. The trash can takes the trash and recognize that it is not recyclable.

3. With the built-in conveyer belt system, the trash can lift the trash out from itself and throw it back to Freddy.

4. Freddy picks up the trash again. 

Too Smart Sign Lego Prototype v.1

1. Freddy is attracted to the sign's movement walks to the sign.
2. The sign notices Freddy and points at him and says, "Who are you?"
3. The sign gives direction to another location.

Initial Video proposal for Too Smart City. Created by David Jimison and JooYoun Paek. 3D Animations by Tonio Jong.


Too Smart City from David Jimison on Vimeo.