Research

We study interfaces. Our group is fascinated by the complex interactions within multi-disciplinary engineering systems and how they also interact with their environments. For this purpose, we study both the interfaces between system components and the relations between multiple domains of expertise. In general, engineers have a remarkable disciplinary expertise and deep understanding of individual components, but often these interfaces and interactions are less well-understood. We believe that the greatest opportunities to design efficient and optimal systems stand on the understanding and characterization of such complex interfaces. Hence, the ESDL group is dedicated to expand the comprehension of interfaces found in engineering systems, and capitalizing on this new knowledge to benefit humanity through optimal design of systems.

Approach

The Engineering System Design Lab at the University of Illinois is engaged currently in three research thrust areas:

Modeling and Optimization of Large-Scale Engineering Systems

Large-scale engineering design problems are challenging due to the large number of components involved, complicated interactions, or numerous design decisions that must be made. A common approach to tackling these large-scale design problems is to break-down the system design problem into several smaller subproblems. Sometimes these partitions are made along disciplinary boundaries (e.g., structural design and aerodynamic design), physical boundaries (automotive suspension design and automotive powertrain design), or functional boundaries. Note that partitioning a systems also requires the analysis and understanding of the interactions between subsystems.

At the ESDL, we study optimization-based methods for solving decomposed system design problems that produce optimal-system solutions. These integrated methods thoroughly account for system interactions and overall system objectives. Specific research topics include automated partitioning and coordination algorithm decisions, developing system models that facilitate successful system design optimization, system architecture design, and topology optimization. Applications of interest include automotive powertrain design (including hybrid electric powertrains), gas turbine engine design, mechatronic/robotic systems, system electrification, wave energy harvesting, structural design and scramjet design optimization.

Integrated Physical and Control System Design (Co-Design)

Many engineered systems operate using embedded control systems. The design of these systems is usually split into several distinct sequential steps: physical system design, control system design, and real-time software development. In current practice the system is typically designed in this sequence, where part of the system design is fixed at each stage, reducing design flexibility and opportunity for improvement. It has been demonstrated theoretically and experimentally that these stages of the design process are coupled. In other words, to achieve the best possible system performance, an integrated design approach that considers all aspects of system design simultaneously is required.

Right now, we are focusing on design methods that can account for the interaction between physical system and control system design. These integrated design methods produce system-optimal designs and help engineers to improve the system performance significantly. In some cases, the co-design methods may help to reduce the complexity of the system design process, resulting in the possibility of adding new system capabilities that were impossible previously. The implementation of co-design methods is catalyzed by engineers who have experience in both physical system design and control system design, as well as expertise in the interface of these components.

Deployment of fully-integrated co-design methods may be impractical for many engineering firms. We are studying intermediate methods that lie between conventional sequential system design and co-design that may be more easily adopted by engineering organizations as a transitional step toward deploying fully-integrated system design approaches.

Sustainable Energy Design

Security and sustainability of energy systems is a critical issue of increasing importance. Reducing energy consumption, through energy efficiency measures and economic incentives, complements efforts to develop and deploy renewable energy systems. Recent studies indicate that energy efficiency improvements stand to yield rapid and substantial progress toward energy sustainability.

Advanced design techniques, such as design optimization, can aid engineers working to create systems that minimize energy consumption, while maintaining competitive system performance and cost. Enhanced design processes can help on several fronts:

  • Refine existing systems: Designers can apply advanced modeling and design methods to reduce mass, improving durability, enable manufacturing processes with lower environmental impact, and design systems that operate more efficiently.
  • Switch to more efficient technology: New technologies, such as electric drives for automobiles, offer significant energy efficiency improvements, but can be a challenge to implement. Fundamental design changes can propagate in unexpected ways. Emerging design tools that help manage the complexities of change in engineering systems can help expedite successful transition to new technology.
  • Accelerate deployment: The impact of new, more efficient, designs is tempered by the time required to them into production. Advanced system design techniques help move critical discoveries and decisions to earlier stages of the product development process, reducing time required to reach production.
  • Facilitate transitions to new solutions: Better design methodology may turn previously infeasible solutions into real alternatives. For example, mechatronic systems are often developed assuming that links are rigid bodies. This simplifies analysis greatly and leads to easier conceptualization of the system design problem, but can result in high-mass, high-energy consumption systems. An integrated approach to mechatronic system design may enable the use of lower-mass flexible components while still meeting performance requirements.

Some relevant projects at the ESDL include electric, hybrid electric, and solar vehicle design, PHEV life cycle analysis, wave energy harvesting, bicycle design, and passenger aircraft design.

While advanced design techniques can help develop energy efficient systems, deploying them on a scale large enough to make meaningful changes requires the right incentives. The technological solution is coupled with economic, cultural, and policy solutions.