Ideas taken from https://services.anu.edu.au/files/development_opportunity/ResearchProposalTips_0.pdf # Title / Topic # Research Problem (Justification) - Why does robust control exist - air conditioning example - but what if the plant is different? What is buddy leaves a window open - We can examine whether or not our controller (the ac unit) can handle the perturbed plant - We can know how open the window is before we have problems - We can guarantee this for this controller design and designed laws - So if we do this can be sure when we build the unit that this is how it will perform? - Well if it's controlled with a microcontroller or other code based solution, no. - The abstraction between the design and the finished controller destroys the guarantee - Things can happen in implementation that make the controller built not true to design - As a result, we need to reverify robustness on built controllers - This exists for structured perturbations. We # Gap In The Literature ### **Slide 1: Robust Control Foundations** **Assertion:** Robust control ensures stability despite system discrepancies. **Evidence:** - Controllers are based on physical models that differ from real systems. - Robust control analyzes resilience to system perturbations. - Evolved from single-input single-output to multi-input multi-output systems. _(Cite Doyle, Green, Brunton)_ --- ### **Slide 2: Structured vs. Unstructured Perturbations** **Assertion:** Robust control addresses structured and unstructured perturbations differently. **Evidence:** - **Structured:** Based on physical tolerances (e.g., spring rates). - **Unstructured:** Accounts for unmodeled dynamics and broader uncertainties. _(Diagram comparing structured and unstructured perturbations)_ _(Cite Doyle, Green)_ --- ### **Slide 3: Disk-Based Unstructured Uncertainty** **Assertion:** Disk-based perturbation quantifies unstructured uncertainties. **Evidence:** - Key equation: $\tilde{P} = (1 + \Delta W_2) P$ - $P$: Nominal plant. - $\Delta$: Perturbation transfer function. - $W_2$: Uncertainty envelope. - Conditions for $W_2$ and $\Delta$: - $\left| \frac{\tilde{P}(j\omega)}{P(j\omega)} - 1 \right| \leq \beta |W_2(j\omega)|$ - $||\Delta||_\infty \leq \beta$. _(Include a visual of how $\Delta$ affects $P$)_ --- ### **Slide 4: Current Limitations in Robust Control** **Assertion:** Current methods lack discrete examples of unstructured perturbations. **Evidence:** - $\Delta$ is undefined for experimental robustness verification. - Structured uncertainties are used experimentally but neglect unmodeled dynamics. _(Cite Farzan, Hamilton)_ --- ### **Slide 5: Diffusion Models as a Solution** **Assertion:** Diffusion models can generate unstructured perturbations. **Evidence:** - Forward process transforms data to Gaussian distribution. - Reverse process generates approximations of target data. - Applications in protein folding, training data generation. _(Diagram of forward/reverse processes in diffusion models)_ _(Cite Sohl-Dickstein, Abramson)_ --- ### **Slide 6: Parallels Between Diffusion Models and This Project** **Assertion:** Diffusion models address sparse perturbation generation in engineering. **Evidence:** - Diffusion models create diverse training data from sparse sets. - Proposed approach: Generate unstructured perturbations from structured sets. _(Illustration of sparse-to-diverse transformation concept)_ # Goals and Outcomes # Research Methodology ### **Slide 1: Research Motivation** **Assertion:** Current methods for generating unstructured perturbations are limited in flexibility and generalizability. - **Evidence:** - Unstructured perturbations lack adaptability to various scenarios. - Proposed approach leverages diffusion generative models for flexible perturbation generation. **Visuals:** - A flowchart contrasting traditional perturbation methods vs. diffusion models. --- ### **Slide 2: Diffusion Model Features** **Assertion:** Frequency response data forms the foundation for feature creation in diffusion models. - **Evidence:** - Features discretize dynamics into a vector of magnitude and phase. - Supports training without imparting unintended structure. **Visuals:** - Diagram from Figure 1 showing the discretization of frequency response. --- ### **Slide 3: Creating Frequency Features** **Assertion:** Discretizing the frequency response enables scalable feature sets. - **Evidence:** - Fine resolution for complex behavior or coarse for computational efficiency. - Features provide physical context across frequency scales. **Visuals:** - Table comparing fine vs. coarse frequency sampling. - Annotated example of magnitude/phase vector with scales labeled. --- ### **Slide 4: Training the Diffusion Model** **Assertion:** Diffusion models learn unstructured perturbations through iterative noise transformation. - **Evidence:** - Forward process adds noise; reverse process removes it. - Training maximizes log-likelihood between input and reconstructed data. **Visuals:** - Flowchart of the diffusion training process. - Key equations (e.g., Eq. \ref{forward_kernel} and \ref{reverse_kernel}) simplified with annotations. --- ### **Slide 5: Generating New Perturbations** **Assertion:** The trained diffusion model generates diverse and flexible perturbations. - **Evidence:** - Outputs are probabilistic, enabling variability. - Perturbation level controlled by adjusting time steps. **Visuals:** - Illustration of forward/reverse process with arrows and annotations. - Graph showing interpolation from partial time steps. --- ### **Slide 6: Ensuring Valid Perturbations** **Assertion:** Generated perturbations must meet robust control requirements. - **Evidence:** - No additional right-hand plane poles. - Supremum gain of Δ below threshold β. **Visuals:** - Diagram of pole-zero constraints. - Workflow for verifying Δ and fitting transfer functions. --- ### **Slide 7: Advantages of Diffusion Models** **Assertion:** Diffusion models provide a novel solution for generating unstructured perturbations. - **Evidence:** - Introduce non-deterministic variability into perturbations. - Overcome the limitations of traditional structured approaches. **Visuals:** - Comparative chart: structured vs. unstructured methods. - Examples of perturbed frequency responses generated by the model. # Metrics of Success # Risks and Contingencies #