Breadboard Demo

Description

The Breadboard Demo is an informal but mandatory event. Its purpose is to show your instructor and TA a circuit that you have been working on in the lab for your project. It is expected that the circuit will include the microprocessor you will be using in your project (it can be mounted on a development board) and it will be connected to a project subsystem. The microprocessor should have a program downloaded onto it that allows it to communicate with the subsystem, i.e., control the subsystem or receive data from it. It is expected that the power source for the circuit will be a laboratory power supply. The function of the subsystem should be demonstrated. The commands or data should be displayed on a pc or other display means. You should be able to explain how the circuit is used in the project and be able to justify design choices. A Breadboard Checklist will be provided and filled out.). Use the following format:

    See the Breadboard Demo Rubric for specific details.

Grading

Full Credit (20 points) will be given if the circuit works, is of adequate complexity, and a good explanation of its features is given by the team. Point reductions will be given if the circuit fails to work (-2), lacks complexity (-2), or seems inappropriate for your project (-2). The Breadboard Demo is a team activity and results in a team score.

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: https://uofi.box.com/shared/static/gst4s78tcdmfnwpjmf9hkvuzlu8jf771.pdf

Team using IQAN system (top right corner): https://engineering.purdue.edu/ABE/InfoFor/CurrentStudents/SeniorProjects/2012/GeskeLamneckSparenbergEtAl

Team using discrete logic (page 19): http://deepblue.lib.umich.edu/bitstream/handle/2027.42/86206/ME450?sequence=1