Fly-by-Pi: Open source closed-loop control for geotechnical centrifuge testing applications

Area of Science:

• Geotechnical Engineering
• Soil Mechanics
• Experimental Physics

Background:

• Geotechnical centrifuges enable cost-effective physical modeling of complex soil behaviors under high stress.
• Existing centrifuge hardware often relies on expensive, closed-source data acquisition and control systems.
• There is a need for accessible, adaptable control solutions for advanced geotechnical testing.

Purpose of the Study:

• To develop and demonstrate a novel, low-cost, open-source data logger and control system for geotechnical centrifuges.
• To provide a versatile system capable of closed-loop control for linear actuators in demanding experimental conditions.
• To encourage the adoption of open-source hardware in extreme testing environments.

Main Methods:

• Development of the Fly-by-Pi system utilizing a Raspberry Pi microcomputer.
• Implementation of closed-loop control for linear actuators, supporting cyclic, monotonic, and static loading/displacement.
• Integration and testing of the Fly-by-Pi system in three independent geotechnical centrifuge experiments.

Main Results:

• The Fly-by-Pi system successfully operated in parallel with existing centrifuge hardware.
• The system demonstrated versatility in controlling actuators and adaptability for reprogramming during experiments.
• Successful application in three distinct experimental scenarios validated the system's performance.

Conclusions:

• The Fly-by-Pi system presents a viable, low-cost, open-source alternative for geotechnical centrifuge control.
• Open-source hardware solutions offer significant advantages in terms of cost, versatility, and adaptability for extreme testing.
• Widespread adoption of such systems can democratize advanced geotechnical research and development.