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30 Amphibious Spherical Explorer
Area Award: Controls
Junhao Su
Kaiwen Chen
Zhong Tan
Luke Wendt design_document0.pdf
The amphibious spherical explorer (ASE) our team is building is mainly for outdoor adventure. The ASE will have no difficulty traveling in water, swamp, dessert, and land due to its spherical shape and pendulum driven principle. Comparing to most robots, ASE will be more versatile since it could travel under most circumstances. As for the other spherical robots, ASE is more adaptable because of its flexible yet enduring shell and at the same time we are aiming to design a better control system to solve the balance issue.

The ASE will be implemented using dual-actuator design consisting of one DC motor and one Servo motor, magnetic encoder, gyroscope, micro-controller, WIFI chip and etc. Specifically, we have decided to build this to be a general-purpose robotic platform as we are planning to leave an I2C bus to interface corresponding interchangeable modules designed for diverse tasks and various usages. The control signal will be sent from PC to the explorer, and the data collected by the task module are transmitted back to the users for debugging. The entire communication process will be accomplished through WIFI.

Our team members have had fair amount of experience in Embedded programming & Control system design, Mechanical CAD, and PCB design which will be efficient through the project building process.

Team members:
Kaiwen Chen (kchen70)
Zhong Tan (zmtan2)
Junhao Su (jsu10)

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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