Case Studies

Bicycle Clutch Testing

Bicycle Clutch Automated Endurance Test System

Posted in Embedded Development & Programming, Green Technology, LabVIEW, Product Development, Test & Measurement Automation, Test and Measurement

Summary

DMC created an automated bicycle clutch testing platform for a high-end specialty bicycle company.  The system performs fully automated endurance, fatigue, and lifecycle testing of a new clutch design by simulating real-world bicycle riding cycles.  The specialty clutch being tested was designed for use in the World Bike, an innovative prototype bicycle for providing a robust and efficient means of transportation for poor rural communities around the globe. 

Main User Interface

Main User Interface

Sequence Editor

Sequence Editor

Real Time Plotting

Real Time Plotting

Solution

DMC developed a LabVIEW application to perform automated endurance and lifecycle testing of bicycle clutches for use in the World Bike program.  The LabVIEW application controls an Animatics 'SmartMotor' servo that is coupled to the clutch.  By rotating the clutch through specified angular displacements at specified angular velocities, the system simulates extended operation of the clutch under real-world bicycle riding conditions.

World Bike is a collaborative bicycle development aimed to providing an alternative to simply walking long distances for transportation of both people and cargo in poor rural communities.  As the world bike site states, the World Bikes are designed to  "withstand large loads, rough terrain and inclement weather and are configured to be not only affordable, but also maintained and repaired locally".  To meet these requirement s every component that goes into the bicycle must be highly robust, require very infrequent maintenance that requires no specialized tools or extensive mechanical knowledge, and must have minimal failure modes under heavy extended use and harsh operating conditions.  These requirements, in turn, necessitated that considerable endurance and lifecycle testing be performed on the customer's newly designed clutches to verify their suitability for the World Bike program.

The system includes a highly versatile test sequence configuration interface.  This allows users to string together series of steps (like basic motion commands) to create complex clutch drive profiles that simulate its actual real-world operation.  Such motion profiles can then be repeated for any desired number of test cycles.  The ability to run long duration endurance tests with one click with no need for operator intervention or supervision has allowed the customer to collect extensive and valuable data with minimal time commitments from engineers or technicians.

Customer Benefits

  • Stability:  Ability to perform extended duration endurance tests of a week or more with no need for operator interaction
  • Flexibiliity: Highly configurable test sequencing provides ability for customer to perform virtually any conceivable simulated operation motion profile
  • Visualization:  Interactive real-time data plotting of angular position, velocity and motor current/torque, with ability to zoom time focus, toggle displayed channels, and configure plot styles
  • Data Logging:  Continuous logging of test data to file at user defined data rate
  • Extensibility:  Platform development included creation of LabVIEW driver for Animatics Smart Motor (a servo motor commonly used by the customer for multiple applications), allowing easy re-use of source code in the future for other automated systems
  • Responsiveness: DMC rapidly implemented a working solution very promptly after receiving the customer's specifications.  Clutch testing was underway within two weeks of the start of the project