# Title Team Members TA Documents Sponsor
14 Propeller-less Multi-rotor
Bree Peng
Ignacio Aguirre Panadero
Leo Yamamae
Luke Wendt appendix0.pdf
The idea is to have 4 of these centrifugal fans in each corner replacing the motor+propeller on a typical drone for greater durability and more options. You may ask, "Is this the same as just swapping out methods of propulsion?" The answer is no. In a typical drone, the half of the motors spin clockwise and the other counter-clockwise. This is because of the angular momentum of the motors. A good example is a helicopter. It has its huge propellers and it has a tail-rotor.

The problem that arises from changing to this method of propulsion is that the drone cannot yaw (turn left or right). The traditional drone increases the RPM on two motors spinning the same direction located diagonally from each other and decreases the RPM of the other two. This will result in keeping altitude and turning left or right by angular momentum. The issue with the centrifugal fan propelled drone is that in order to yaw, the direction of the fan must be changed. Therefore, we will need to use an actuator to change the direction.

The ultimate goal is to build a drone that uses a centrifugal fan as a method of propulsion and map the controls such that an experienced multi-rotor flyer will be able to pick up the controller and fly it. So it will be an remote-controlled drone that will be using a typical RC transmitter and receiver or a XBEE talking to a xbox/PlayStation controller.

Therefore, my project will include:
Design of the Flight Control Board
Design of the Chassis,
Design of the Centrifugal Fans,
Actuation design,
Finding parts (ESC if we buy it, Battery, sensors, etc.)

Electronic Automatic Transmission for Bicycle

Tianqi Liu, Ruijie Qi, Xingkai Zhou

Featured Project

Tianqi Liu(tliu51)

Ruijie Qi(rqi2)

Xingkai Zhou(xzhou40)

Sometimes bikers might not which gear is the optimal one to select. Bicycle changes gears by pulling or releasing a steel cable mechanically. We could potentially automate gear changing by hooking up a servo motor to the gear cable. We could calculate the optimal gear under current condition by using several sensors: two hall effect sensors, one sensing cadence from the paddle and the other one sensing the overall speed from the wheel, we could also use pressure sensors on the paddle to determine how hard the biker is paddling. With these sensors, it would be sufficient enough for use detect different terrains since the biker tend to go slower and pedal slower for uphill or go faster and pedal faster for downhill. With all these information from the sensors, we could definitely find out the optimal gear electronically. We plan to take care of the shifting of rear derailleur, if we have more time we may consider modifying the front as well.

Besides shifting automatically, we plan to add a manual mode to our project as well. With manual mode activated, the rider could override the automatic system and select the gear on its own.

We found out another group did electronic bicycle shifting in Spring 2016, but they didn't have a automatic function and didn't have the sensor set-up like ours. Commercially, both SRAM and SHIMANO have electronic shifting products, but these products integrate the servo motor inside the derailleurs, and they have a price tag over $1000. Only professionals or rich enthusiasts can have a hand on them. As our system could potentially serve as an add-on device to all bicycles with gears, it would be much cheaper.

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