Cyclist Mannequin For Aerodynamics Research

Abstract

The aim of this research is to increase the speed of cyclists by reducing aerodynamic drag. Common research methods are digital and physical simulations. The goal is this project is to develop an anthropometric model for each method based on professional cyclists from Team DSM.

Digital Model (Generic)
The first goal of this research is to create a generic cyclist model for research organisations around the world. The Generic Model is an average of ten male, professional cyclists in both road and time trial pose (Figure 0.1). The DINED Mannequin approach is used to divide the method into four steps: Capture, Process, Correspond & Average.

All participants are captured on-site on personal bicycles with two handheld Artec Eva 3D scanners. The 3D scanned data is processed in Artec Studio 12 to correct for movement and unwanted elements captured during 3D scanning. The processed model is corresponded in R3DS Wrap3 with a reference base mesh template to make them interpretable and to patch missing data. The corresponding models are averaged in Paraview to generate the Generic Model.

The Generic Model stays true to the original anthropometric data of the participants where possible. However, exceptions are made where beneficial to the result. The participants are captured in the high-drag leg position with the hands separated. Shoes are digitally removed from the model. Hands, elbows and inner legs are standardizations because these sections are blocked by the bicycle. The base mesh has a resolution of 50K uniform, smoothened triangle polygons.

Physical Mannequin (Personalized)
The second goal of this research is to design a personalized cyclist mannequin for aerodynamics researchers. The Personalized Mannequin is the physical representation of an individual cyclist’s anthropometry in time trial pose (Figure 0.2). The Centre of Design for Advanced Manufacturing Approach is used to divide the process into four steps: Digitalization, Design Automation, Digital Fabrication & Production.

The 3D anthropometric data of one of the riders captured for the Generic Model is used. Requirements for the mannequin are parametrically defined and partially applied in Grasshopper (automated) and fully applied in Blender (manually). A full-scale model of the mannequin is digitally fabricated using FDM 3D printing. Loose parts are joined, sanded, finished and assembled to complete the prototype.

The requirements and design are the result of an analysis phase where users, context, interactions and competitors are researched. The creative phase structures and clusters challenges and generates solutions to them. The development phase continues with the selected concept and researches individual design features. The final design is prototyped and validated and any recommendations are made last.

Rupert the Personalized Mannequin is CNC milled from rigid polyurethane foam. It is segmented near the wrists, upper arms and upper legs to apply any cycling gear. SLS 3D Printed magnetic, form-fitting interfaces attach the limbs. Rupert is mounted to the bicycle on a regular saddle, with cycling shoes to the pedals and with flexible hands to the handlebar. Rupert has the same surface resolution as the Generic Model.