'Flappy Bird': Collar Fatigue Test Rig - Halter
Versatile Testing Jig for Stress-Inducing Motion Analysis
Features of the 'Flappy bird' Jig:
- Continuously flap up to 25 collars at a variable range from 0 to 200Rpm.
- Utilizes a PID-controlled external controller with a digital potentiometer to maintain a consistent RPM, effectively managing the torque of the motor.
- Equipped with a range of sensors, including inductive proximity sensors, accelerometers, encoders, as well as temperature, humidity, and pressure sensors. These sensors continuously monitor the operational status and detect any anomalies.
- All sensor data is logged and transmitted over WiFi using an ESP32, programmed in C++.
- Continuously flap up to 25 collars at a variable range from 0 to 200Rpm.
- Utilizes a PID-controlled external controller with a digital potentiometer to maintain a consistent RPM, effectively managing the torque of the motor.
- Equipped with a range of sensors, including inductive proximity sensors, accelerometers, encoders, as well as temperature, humidity, and pressure sensors. These sensors continuously monitor the operational status and detect any anomalies.
- All sensor data is logged and transmitted over WiFi using an ESP32, programmed in C++.
- Designed to operate continuously for up to 500 hours in extreme conditions, including 95% relative humidity and a temperature range of -10°C to 70°C, before requiring maintenance.
- Make some cool beats
Background and Learnings
This project, nicknamed Flappybird, due to the motion of the collar while being tested on it was part of the larger project of increasing the reliability of the Halter collars, it sought to replicate the stress-inducing movements that collars would experience within their product life stage. The goal was to identify new failure modes to inform design decisions and validate new changes to the collar design against the current design. This project also provided a platform for the introduction of multi-stress testing via combined loading in the future. The Flappybird project followed a comprehensive end-to-end design process. This included conducting design reviews in collaboration with the wider hardware team, making iterative adjustments to accommodate evolving requirements, specifying the electronics and control system requisites, placing orders for critical components, executing the build and assembly phases, and ultimately subjecting the system to validation – all within a tight, 4-week timeline.
Based on my experience with past jigs, reliability, and reparability have been significant concerns, particularly during the early stages of testing. Jigs tearing themselves apart due to entanglement or abnormal behavior had caused a significant loss of valuable time and resources, leading to longer testing timelines. The use of electronics, such as motors, control circuitry inside the thermal chamber was also to be avoided to increase reliability. Learnings from previous designs were implemented prior to the design phase of this project.
This project, nicknamed Flappybird, due to the motion of the collar while being tested on it was part of the larger project of increasing the reliability of the Halter collars, it sought to replicate the stress-inducing movements that collars would experience within their product life stage. The goal was to identify new failure modes to inform design decisions and validate new changes to the collar design against the current design. This project also provided a platform for the introduction of multi-stress testing via combined loading in the future. The Flappybird project followed a comprehensive end-to-end design process. This included conducting design reviews in collaboration with the wider hardware team, making iterative adjustments to accommodate evolving requirements, specifying the electronics and control system requisites, placing orders for critical components, executing the build and assembly phases, and ultimately subjecting the system to validation – all within a tight, 4-week timeline.
Based on my experience with past jigs, reliability, and reparability have been significant concerns, particularly during the early stages of testing. Jigs tearing themselves apart due to entanglement or abnormal behavior had caused a significant loss of valuable time and resources, leading to longer testing timelines. The use of electronics, such as motors, control circuitry inside the thermal chamber was also to be avoided to increase reliability. Learnings from previous designs were implemented prior to the design phase of this project.
Some key particular issues to note:
- Total cycle time unknown if Jig has stopped running overnight. Requires repetition of the test conducted to gain confidence in failure if present.
- The jigs also suffered further damage due to lost parts, as they continued running until they stopped, as the motion is periodic. This can put additional loading on the motors and other parts, decreasing their life cycle.
To address issues of reliability and reparability, I sought to increase the availability of the jig. This can be achieved by either increasing reliability through detailed design, considering every failure case and addressing it in the design phase, or by increasing the reparability of the jig by reducing the service/repair time.
The above was achieved with the following measures in place:
- Data Logging:- Logging of cycle time/Count to external SD card/Google Excel sheet via external sensors. The jig is continuously monitored and logging is done via a Esp32.
- Redundancy: Introduced redundancy and fail-safe mechanisms to ensure the system can continue operating or safely stop in the event of component failure. This primarily concerns any sensors the jig relies on being operational/data logging.
These above were implemented and the Jig has been utilized and running continuously for weeks sustainably. This project was extremely valuable for me, as it allowed me to apply systems-level thinking, consider every failure point of the design, and explore different ways to resolve them. This project ran on a red/green light schedule, where the timeline was designed to be perfect with minimal redundancy in place, It required identifying potential failure points within the schedule and proactively working to ensure they could be resolved. This experience underscored the vital lesson of never becoming the rate-limiting factor and taking complete ownership of every aspect of the project and its deliverables.
These above were implemented and the Jig has been utilized and running continuously for weeks sustainably. This project was extremely valuable for me, as it allowed me to apply systems-level thinking, consider every failure point of the design, and explore different ways to resolve them. This project ran on a red/green light schedule, where the timeline was designed to be perfect with minimal redundancy in place, It required identifying potential failure points within the schedule and proactively working to ensure they could be resolved. This experience underscored the vital lesson of never becoming the rate-limiting factor and taking complete ownership of every aspect of the project and its deliverables.
Summary of learnings:
- The importance of choosing the correct form of communication: to minimize the feedback loop on important decisions to deliver results with clarity yet a rapid turnaround time.
- Keeping clear expectation of the project timeline: introducing blockers with the team to ensure full transparency is present, which allows for potential collaboration to resolve them. I found it immensely useful to keep track of all shipments, tasks and blockers in a visual timeline, this kept day to day priority well defined.
- The importance of design reviews, when to use them, and when to be critical of them: they help gather valuable feedback and catch potential problems early. However, they should be used wisely and evaluated critically. To be effective, they need to be focused with a clear and achievable agenda; otherwise, they can end up wasting everyone's time with limited results.
