RESEARCH

Machine learning holds great promise for identifying various input-output relationships in complex systems. However, in scenarios where black-box machine learning methods are applied, the learning process typically requires vast amount of data. Our research aims to design graph-based machine/deep learning model structures that are compatible with basic physics, or principles, thus, eliminating data requirement for establishing those principles; and then, using those model structures for real-time actions as they are trained online with the system's output data. Such actions include digital twin update for predictive maintenance and energy consumption management, feedback control for tracking desired output, or even  system re-design.

FOCUS AREAS

Graph-Based Neurosymbolic Modeling & Control for Direct Laser Deposition (DLD) Additive Manufacturing (AM)

In DLD,  a laser beam is used to melt locally deposited material powder and create geometries layer by layer. This complex process involves fast cycles of melting and solidification of metal powder. Our research aims to build a graph-based neurosymbolic modeling framework for the process, and develop a control scheme accordingly. The scheme will manipulate in-process parameters to ultimately improve geometry accuracy and mechanical properties of the parts, and expedite build time.

Model Predictive Force & Temperature Control for Thermomechanical Forming in Hybrid Manufacturing

In hybrid manufacturing, in addition to additively creating a solid part, a subtractive or deformative process is performed in situ on the solid material. These additional processes help to improve microstructural and surface properties of the finished parts but add on further complexity.  Our research here seeks to control the microstructural evolution in an additive + incremental forming hybrid manufacturing setting using graph-based modeling. We also seek to achieve well-controlled interfaces in multi-material hybrid manufacturing.  

Neurosymbolic Generative Modeling for Control Co-design in Hybrid Manufacturing

Digitalized manufacturing processes, such as AM and incremental forming, open a major path planning question: In what sequence should the manufacturing tools carry out the processes? We seek to use deep generative models to find (sub)optimal tool trajectories that maximize control authority.  We also seek to implement control co-design of fixed process parameters.

Estimation and Control Co-design in Thermal Energy Storage Sytems

In Thermal Energy Storage (TES) systems, energy is stored in form of sensible or latent heat, or by thermochemical reactions. TES devices are employed in a variety of applications ranging from grid-level and household storage for electricity to thermal management systems in aircrafts . Our interest in these systems involve control-oriented graph-based models for state of charge estimation as well as  control co-design.