# Title Team Members TA Documents Sponsor
12 Hands-free DJ
Jie Du
Ningkai Wu
Yifei Teng
Jacob Bryan design_review
In a party, the DJ is the guy responsible for supplying everyone an endless stream of entertaining music. But we all know he deeply wants to join the party! So we’ll build a remote gesture controlled DJ console that every DJ can take into the action.

Formal description: Our system comprises two parts,
1. A compact device that straps to one’s hand and collects gesture information. The gesture can be used to navigate a playlist, change various effects, manipulate voice recorded from a microphone etc.
2. A phone app that implements the various signal processing functions and outputs the music. The app is driven by gesture data from the embedded device.

To send gesture data from the device to the app, we use the Bluetooth Low Energy protocol. The embedded device will contain a battery, an accelerometer, a gyroscope, a magnetometer, a barometer, a microphone, and a few buttons for testing. It fuses sensor data to estimate the pose of the hand, in the form of orientation and change in height. The microphone can detect one-shot events such as snapping a finger. We will define a custom protocol to stream these events along with continuously changing gesture data to the phone, which will make use of these data to perform signal processing tasks. In addition, the phone will record the user’s voice through a microphone and mix it into the final audio. The microchip on the embedded device will need to be reasonably powerful to perform sensor fusion and at the same time monitoring the microphone for the characteristic sound of finger snapping.

Here is a list of functionalities we propose (non exhaustive):
1. Vocoder to change the texture of one’s voice.
2. Pitch shifting
3. Looping at the snap of a finger (background beatboxing?)
4. Reverb/Chorus
5. Switching background music, or advancing to the next item in a playlist
6. Pause/Resume
7. Wah-wah effect
8. One-shot sound effect (laugh track etc.)

For the sensors we plan to use the MPU-9250, and for the microcontroller we plan to use the LPC1768 Cortex-M3 chip. Of course there will be relevant ADC and regulator circuits for the microphone and battery as well.

Control System and User Interface for Hydraulic Bike

Iain Brearton

Featured Project

Parker-Hannifin, a fluid power systems company, hosts an annual competition for the design of a chainless bicycle. A MechSE senior design team of mechanical engineers have created a hydraulic circuit with electromechanical valves, but need a control system, user interface, and electrical power for their system. The user would be able to choose between several operating modes (fluid paths), listed at the end.

My solution to this problem is a custom-designed control system and user interface. Based on sensor feedback and user inputs, the system would change operating modes (fluid paths). Additionally, the system could be improved to suggest the best operating mode by implementing a PI or PID controller. The system would not change modes without user interaction due to safety - previous years' bicycles have gone faster than 20mph.

Previous approaches to this problem have usually not included an electrical engineer. As a result, several teams have historically used commercially-available systems such as Parker's IQAN system (link below) or discrete logic due to a lack of technical knowledge (link below). Apart from these two examples, very little public documentation exists on the electrical control systems used by previous competitors, but I believe that designing a control system and user interface from scratch will be a unique and new approach to controlling the hydraulic system.

I am aiming for a 1-person team as there are 6 MechSE counterparts. I emailed Professor Carney on 10/3/14 and he thought the general concept was acceptable.

Operating modes, simplified:

Direct drive (rider's pedaling power goes directly to hydraulic motor)

Coasting (no power input, motor input and output "shorted")

Charge accumulators (store energy in expanding rubber balloons)

Discharge accumulators (use stored energy to supply power to motor)

Regenerative braking (use motor energy to charge accumulators)

Download Competition Specs:

Team using IQAN system (top right corner):

Team using discrete logic (page 19):