Research & Tech Development
Oscillator Computers
Oscillators are physical systems that are capable of complex dynamics. Surprisingly, they can act as non-traditional computers through the use of machine learning, which can convert them to reservoir computers. We built a Hopf oscillator-based reservoir computer that is capable of reconfigurable computing tasks. For a stream of True and False statements shown in (a), the OR, AND, and NOT gates are computed with the reservoir computer. The results of these gates are shown in (b), (c), and (d), respectively.
Md Raf E Ul Shougat, XiaoFu Li, Edmon Perkins, “Multiplex-free physical reservoir computing with an adaptive oscillator”, Physical Review E (2024).
Md Raf E Ul Shougat, Edmon Perkins, “The van der Pol Physical Reservoir Computer”, Neuromorphic Computing and Engineering (2023).
Md Raf E Ul Shougat, XiaoFu Li, Siyao Shao, Kathleen McGarvey, Edmon Perkins, “Hopf Physical Reservoir Computer for Reconfigurable Sound Recognition”, Scientific Reports (2023).
Md Raf E Ul Shougat, XiaoFu Li, Edmon Perkins, “Dynamic Effects on Reservoir Computing with a Hopf Oscillator”, Physical Review E (2022).
Md Raf E Ul Shougat, XiaoFu Li, Tushar Mollik, Edmon Perkins, “A Hopf Physical Reservoir Computer”, Scientific Reports (2021).
Md Raf E Ul Shougat, XiaoFu Li, Tushar Mollik, Edmon Perkins, “An Information Theoretic Study of a Duffing Oscillator Array Reservoir Computer”, Journal of Computational and Nonlinear Dynamics (2021).
Adaptive Oscillators
Adaptive oscillators are a subset of nonlinear oscillators that can intrinsically learn and store information. This information is directly stored in an analog form in a plastically-deformable, dynamic state. For instance, a pendulum (shown on the left) can store frequency content as the length of the pendulum's rod. Adaptive oscillators have unique applications as resonance-tracking broadband energy harvesters, smart robotic gait controllers, and fully analog frequency analyzers.
XiaoFu Li, Md Raf E Ul Shougat, Tushar Mollik, Robert Dean, Aubrey Beal, Edmon Perkins, “Field-programmable analog array (FPAA) based four-state adaptive oscillator for analog frequency analysis”, Review of Scientific Instruments (2023).
XiaoFu Li, Aubrey Beal, Robert Dean, Edmon Perkins, “Chaos in a Pendulum Adaptive Frequency Oscillator Circuit Experiment”, Chaos Theory & Applications (2023).
XiaoFu Li, Pawan Kallepalli, Tushar Mollik, Md Raf E Ul Shougat, Scott Kennedy, Sean Frabitore*, Edmon Perkins, “The Pendulum Adaptive Frequency Oscillator”, Mechanical Systems and Signal Processing (2022).
XiaoFu Li, Md Raf E Ul Shougat, Tushar Mollik, Aubrey N. Beal, Robert Dean, Edmon Perkins, “Stochastic Effects on a Hopf Adaptive Frequency Oscillator”, Journal of Applied Physics (2021).
XiaoFu Li, Md Raf E Ul Shougat, Scott Kennedy, Casey Fendley, Aubrey N. Beal, Robert N. Dean, Edmon Perkins, “A four-state adaptive Hopf oscillator”, PLoS One (2021).
Biomimetic Mechatronics
Biological systems have profound abilities, which rely on the complex relationships between functional morphology & computing. We seek to tap into these abilities through several directions. We want to create enhanced shape memory alloy actuators that are capable of self-sensing, quick responses, large deformations, and optimized trajectories, while still having a small form factor and inexpensive fabrication process. We also seek to unlock the computational abilities of biological tensegrities, such as the one depicted on the right. This simulation highlights our custom discrete element method joint simulator, which directly uses CT scanned images.
Md Raf E Ul Shougat, Scott Kennedy, Edmon Perkins, “A Self-Sensing Shape Memory Alloy Actuator Physical Reservoir Computer”, IEEE Sensors Letters (2023).
Scott Kennedy, Md Raf E Ul Shougat, Edmon Perkins, “Robust Self-sensing Shape Memory Alloy Actuator Using a Machine Learning Approach”, Sensors and Actuators A: Physical (2023).
Tushar Mollik, Scott Kennedy, Md Raf E Ul Shougat, XiaoFu Li, Timothy Fitzgerald, Scott Echols, Nick Kirk, Larry Silverberg, Edmon Perkins, “Discrete Element Method Simulator for Joint Dynamics”, Multibody System Dynamics (2022).
Scott Kennedy, Nicholas Vlajic, Edmon Perkins, “Cosserat modeling for deformation configuration of shape memory alloy unimorph actuators”, Journal of Intelligent Material Systems and Structures (2022).
Scott Kennedy, Morgan Price, Michael Zabala, Edmon Perkins, “Vibratory Response Characteristics of High Frequency Shape Memory Alloy Actuators”, Journal of Vibration and Acoustics (2020).