Projects:2019s1-124 Development of a Tool for Naturalistic Measurement of Vehicle-Cyclist Passing Distances

Members: Scott Adamson Robert Broadhead Max Telford

Supervisors: Braden Phillips Jamie Mackenzie (CASR)

Motivation

While cycling is a mode of transport to be encouraged, cyclists are far more likely to be killed or hospitalised from road accidents than other commuters [1]. Having accurate data on where, how often, and how close cars overtake cyclists is an important step towards improving the laws and infrastructure that keep cyclists safe.

Aim

This project is sponsored by the Centre for Automotive Safety Research (CASR) and seeks to improve and validate the capabilities of an existing bicycle mounted device for measuring vehicle-cyclist passing distances. The three areas of focus are the sensor choice, device design and verification.

Sensor Choice

Existing Limitations:
Measurement Frequency and Size
Sensor considerations:
Measurement Frequency
Resolution/Accuracy
Cost
Durability
Power Consumption
Size
Weight
Communication
Interference
Other Output Data

Available technologies and sensors:
Ultrasonic and LiDAR

Conclusion:
On-road testing results showed both LiDAR sensors were able to detect 38% more overtakes than the ultrasonic sensor. A particular  LiDAR sensor was chosen as it is not limited by frequency and maintained accuracy in all lighting conditions. This will allow the sensor housings to be considerably smaller whilst maintaining durability and detecting more overtakes.

Verification

Verifying the accuracy of the data collected adds value to existing and all future trial results. The steps taken to verify the device are as follows:

• Mount a Raspberry Pi camera to the bicycle
  
• Sync the camera with the sensor data
  
• Analyse the video and accuracy of the sensors
  
• Build and implement a detection algorithm
  

Conclusion:
 Testing revealed video recordings as costly and time consuming method, but allowed for more efficient sensor detection algorithms to be developed.

Device Design

A waterproof 3D-printed housing was designed to contain the onboard electronics including the data logger module, GPS module and a custom Printed Circuit Board (PCB). The device was designed with the following considerations:

• Intuitive Useability
• Weather Conditions
• Size and Shape
• Attachment to Bicycle
• Data Retrieval
• Cost
• Manufacturability
• Battery Life
• Maximum of 100 Units Produced

The PCB was designed to manage the connection of the modules to:

• Sensors
• Micro USB Charging Port
• Battery
• Pushbutton Switch
• Red/Green LED

Conclusion:
A device was successfully developed that met the requirements of the project. It is weatherproof and�easier to use.