Development of a Powertrain Matching Analysis Tool

The development of a Powertrain Matching Analysis Tool (PMAT) addresses the challenge of matching the powertrain hardware and control strategy to specific vehicle attributes and driver applications for improved overall vehicle system efficiency. PMAT consists of a reverse tractive road load demand model and a dynamic optimization algorithm developed in MATLAB® and Simulink®. The reverse tractive road load demand model propagates the required wheel torque and speed derived from vehicle speed and road grade through the powertrain system to determine the required fuel flow for various states. The control strategy is treated as a multi-stage, multi-dimension decision process, where dynamic programming is applied to find an optimal control policy that minimizes the accumulated fuel flow over a drive cycle. PMAT is used to assess and develop transmission shift and lock-up control strategies, evaluate powertrain hardware configurations, and establish design criteria. PMAT can also virtually optimize multi-displacement cylinder deactivation system (MDS) operation taking gear and clutch control interaction effects into account. The advantages of the PMAT approach are demonstrated and key system integration concepts are revealed.