We have a small child who loves his wooden train tracks, and we want to build track configurations in arrangements of ever-increasing complexity. The problem is that we disassemble the tracks every night before bedtime (both because there isn't enough space in our living room for a permanent installation, and because the constructor also relishes the opportunity to be the destructor).
I would like to create programmable train tracks that can store and re-create a previous configuration.
1. The existing commercial wooden tracks have an attractive simplicity, do not have small parts that would be hazardous to vacuum cleaners or small throats, and are relatively indestructible, even in the hands of a cranky 2-year old. We wish to preserve all of these characteristics in the new design.
2. In order to achieve the goal of creating large structures, the cost of the individual components must be kept low. For comparison, existing "dumb" track retail price is in the neighborhood of $0.25 per linear inch (see, for instance, http://www.woodentracks.com/CTGY/Wooden_Train_Track.html).
3. The track must be capable of saving and restoring configuration state. It would be acceptable if the mechanism for these actions relied on the presence of an external controller, preferably embedded in a train, but possibly requiring a connection to a computer.
4. All features must be usable by a pre-literate 2-year-old. Challenges involve comprehension, attention span, and motor control.
1. When the tracks bend to create a specified configuration, the order in which the bending takes place must be optimized such that each bending action is within the mechanical force limits of the bending mechanism. For example, consider bending a long straight track into a "V" shape. It may not be possible to accomplish simply by bending the middle of the track to the desired angle, because this would require a single joint to be able to move a long arm of track. Instead, it may be necessary to gradually move segments into place with an inchworm-like movement or another strategy that minimizes the length of track being moved with each bending motion.
2. Once a segment of track has been bent to the desired configuration, it should be able to remain in rigidly in that shape without requiring additional energy input. A possible solution would be to mechanically lock it into place. Perhaps we should take advantage of something like Ara Knaian's electro-permanent stepper motors.