Project

# Title Team Members TA Documents Sponsor
36 Anti-Lock Braking for Bicycles
Aidan Rodgers
Ethan Chastain
Leon Ku
Nithin Balaji Shanthini Praveena Purushothaman design_document4.pdf
final_paper2.pdf
other1.jpeg
photo1.jpeg
presentation1.pptx
proposal2.pdf
video
Anti-Lock Braking for Bicycles

Team Members:
- Ethan Chastain (ecc5)
- Aidan Rodgers (aidanfr2)
- Leon Ku (leonku2)

# Problem

Bicycles present a challenge because they often lack or charge a premium for the features that cars have, like Anti-Lock Braking Systems (ABS). This happens because bicycles are primarily designed for short distance commuting. Unlike cars that come with a range of amenities, bicycles prioritize simplicity. However, this difference in design leads to a discrepancy in safety and convenience features. Bicycle riders do not have the braking capabilities and automated speed regulation that many cars offer. This absence of features like ABS can be particularly dangerous as bicycles are prone to skidding; thus increasing the risk of accidents. As mobility solutions, bicycles sacrifice these functionalities, which means riders must navigate roads with heightened awareness and limited technological assistance.

# Solution

In order to improve the safety of bicycles via cheaper, preventative features, we could consider adding technologies commonly used in cars. For instance, adding an Anti-lock Braking System (ABS) would reduce the risk of skidding by braking more efficiently; thereby improving overall safety. More importantly, the use of ABS ensures better stability for riders and helps prevent accidents like collisions at an intersection. By embracing these technologies, bicycles can offer riders safer, cheaper rides with improved ease of use. We plan to use one of the bikes provided by the workshop and add a braking system that both detects locking and modulates braking to account for it.

# Solution Components

## Subsystem 1 - Speed sensing

We plan to use a Hall effect sensor (potential part number: DRV5023BIQLPGMQ1) to sense rotational motion of the bicycle’s rear wheel, to determine the speed of the bicycle. This will interface directly with the microcontroller to allow for the braking system to pulse the brakes if locking occurs. The sensor will also be used to record data, in order to test for proper operation.

## Subsystem 2 - Braking

This system takes inputs from the microprocessor to operate the brakes of the bicycle. The braking subsystem consists of a servo motor and a gear system to mechanically pull the brake cable, upon input from the microprocessor. As this system will interfere with the normal mechanical braking system of the bicycle, we will implement buttons in place of the typical brake controls on the handlebars, which will interface with the microprocessor to allow for the bicycle to brake.

## Subsystem 3 - Microprocessor

The microprocessor subsystem will take information from the Hall effect sensors about the rotational speed of the bicycle’s wheel. This subsystem will use an ATMega controller to implement the control algorithms. We plan to use LQR or PID control as a means of tracking constant slopes to prevent wheel locking when decelerating. By this method, we will be able to flash a controller onto the microcontroller in order to embed our control on the PCB.

# Criterion For Success

To qualitatively test the bicycle’s anti-lock braking mechanism, we will place the bicycle on a treadmill and slam the brakes, to observe visually the bicycle’s braking operation. During this test, data from the Hall effect sensor relating to the speed of the bicycle’s rear wheel will be recorded during the test, demonstrating that the bicycle is slowing down properly and efficiently.


Covert Communication Device

Ahmad Abuisneineh, Srivardhan Sajja, Braeden Smith

Covert Communication Device

Featured Project

**Partners (seeking one additional partner)**: Braeden Smith (braeden2), Srivardhan Sajja (sajja3)

**Problem**: We imagine this product would have a primary use in military/law enforcement application -- especially in dangerous, high risk missions. During a house raid or other sensitive mission, maintaining a quiet profile and also having good situational awareness is essential. That mean's that normal two way radios can't work. And alternatives, like in-ear radios act as outside->in communication only and also reduce the ability to hear your surroundings.

**Solution**: We would provide a series of small pocketable devices with long battery that would use LoRa radios to provide a range of 1-5 miles. They would be rechargeable and have a single recessed soft-touch button that would allow someone to find it inside of pockets and tap it easily. The taps would be sent in real-time to all other devices, where they would be translated into silent but noticeable vibrations. (Every device can obviously TX/RX).

Essentially a team could use a set of predetermined signals or even morse code, to quickly and without loss of situational awareness communicate movements/instructions to others who are not within line-of-sight.

The following we would not consider part of the basic requirements for success, but additional goals if we are ahead of schedule:

We could also imagine a base-station which would allow someone using a computer to type simple text that would be sent out as morse code or other predetermined patterns. Additionally this base station would be able to record and monitor the traffic over the LoRa channels (including sender).

**Solutions Components**:

- **Charging and power systems**: the device would have a single USB-C/Microusb port that would connect to charging circuitry for the small Lithium-ion battery (150-500mAh). This USB port would also connect to the MCU. The subsystem would also be responsible to dropping the lion (3.7-4.2V to a stable 3.3V logic level). and providing power to the vibration motor.

- **RF Communications**: we would rely on externally produced RF transceivers that we would integrate into our PCB -- DLP-RFS1280, https://www.sparkfun.com/products/16871, https://www.adafruit.com/product/3073, .

-**Vibration**: We would have to research and source durable quiet, vibration motors that might even be adjustable in intensity

- **MCU**: We are likely to use the STM32 series of MCU's. We need it to communicate with the transceiver (probably SPI) and also control the vibration motor (by driving some transistor). The packets that we send would need to be encrypted (probably with AES). We would also need it to communicate to a host computer for programming via the same port.

- **Structural**: For this prototype, we'd imagine that a simple 3d printed case would be appropriate. We'd have to design something small and relatively ergonomic. We would have a single recessed location for the soft-touch button, that'd be easy to find by feel.

**Basic criterion for success:** We have at least two wireless devices that can reliably and quickly transfer button-presses to vibrations on the other device. It should operate at at *least* 1km LOS. It should be programmable + chargeable via USB. It should also be relatively compact in size and quiet to use.

**Additional Success Criterion:** we would have a separate, 3rd device that can stay permanently connected to a computer. It would provide some software that would be able to send and receive from the LoRa radio, especially ASCII -> morse code.