Cycling Airbag

Design of a Clavicle Protection System for Cyclists

Introduction

This project focuses on the development of a device to prevent clavicle fractures in cyclists. Clavicle injuries are common in cycling, particularly among experienced riders who train for more than ten hours per week. The "Hovding helmet" serves as inspiration, demonstrating the feasibility of sensor-activated airbags for impact protection.

Challenges

The unpredictable nature of cycling falls presents significant challenges. Modeling kinematics requires assumptions about rider trajectory and impact conditions. Additionally, the chosen design must balance functionality, durability, ventilation, and mass.

Methodology

The design process followed a structured framework:

  1. Client Need: Identify the target market and their needs.
  2. Objectives: Define specific design goals.
  3. Pugh's Total Design: Utilise a design matrix to evaluate and compare multiple concepts.
  4. Sequential Analysis of Functional Elements (SAFE): Analyse functional elements sequentially to refine the design.
  5. Movement and Forces: Analyse the kinematics of a fall to predict impact forces.
  6. Reference Product: Analyse existing products for inspiration and benchmarking.

Concepts

Several concepts were explored, including:

  • Adapting existing bicycle helmet technology.
  • Implementing a garment with integrated protection.
  • Borrowing designs from other sports, such as American football and motorcycling.

Design and Analysis

The final design consists of an airbag system activated by accelerometers and gyroscopes. This system is integrated into a garment worn by the cyclist.

Kinematics were analysed using Solidworks and ADAMS software. A 1 DOF model was created, incorporating anthropometric data and British standards. The model was validated using Hertzian contact theory, static friction models, and Lagrangian substitution.

Results and Conclusion

The chosen design has the potential to reduce peak impact forces on the clavicle. However, further refinement is necessary, including:

  • Finite element analysis (FEA) of the clavicular system.
  • Development of a slip plane mechanism to further dissipate impact energy.
  • Rigorous testing to validate the design's effectiveness.

This project demonstrates the application of engineering principles to address a real-world safety concern. The design process involved a combination of research, analysis, and simulation to develop a viable solution. Further development and testing are necessary to bring this design to market