Michael Kokkolaras

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Hybrid propulsion systems are one of the critical technologies on the roadmap to future ultra-efficient trucks. While there is a significant body of work related to hybrid passenger cars and light commercial trucks, there are many open issues related to hybridisation of heavier trucks intended for both onand off-road use. This work addresses those questions(More)
The methods of analytical target cascading (ATC) and collaborative optimization (CO) are studied with respect to their intended use and applicability. ATC was initially developed as a product development tool, while CO evolved from efforts to coordinate multidisciplinary analyses using a multidisciplinary design optimization (MDO) formulation. ATC and CO(More)
The target cascading methodology is applied to the conceptual design of an advanced heavy tactical truck. Two levels are defined: an integrated truck model is represented at the top (vehicle) level and four independent suspension arms are represented at the lower (system) level. Necessary analysis models are developed, and design problems are formulated and(More)
Identification of the product platform is a key step in designing a family of products. This article presents a methodology for selecting the product platform using information obtained from the individual optimization of the product variants. Under the assumption that the product variety requires only mild design changes, a sharing penalty vector (SPV) is(More)
Designing a family of product variants that share some components usually entails a performance loss relative to the individually optimized variants due to the commonality constraints. Choosing components for sharing may depend on what performance losses can be tolerated. This article presents a methodology for making commonality decisions while controlling(More)
Analytical target cascading (ATC) is a methodology for hierarchical multilevel system design optimization. In previous work, the deterministic ATC formulation was extended to account for random variables represented by expected values to be matched among subproblems and thus ensure design consistency. In this work, the probabilistic formulation is augmented(More)
Computer modeling and simulation are the cornerstones of product design and development in the automotive industry. Computer-aided engineering tools have improved to the extent that virtual testing may lead to significant reduction in prototype building and testing of vehicle designs. In order to make this a reality, we need to assess our confidence in the(More)
This paper presents a methodology for design optimization of decomposed systems in the presence of uncertainties. We extend the analytical target cascading (ATC) formulation to probabilistic design by treating stochastic quantities as random variables and parameters and posing reliability-based design constraints. We model the propagation of uncertainty(More)
Analytical Target Cascading (ATC) is a product development tool that computes component design specifications such that the final system design is consistent and meets design targets. ATC is useful for complex product design that must be approached by decomposition, and facilitates concurrent design activities. While ATC has been applied successfully to(More)