“Lean Powertrain Development”

1. What is a Powertrain? • The complete system that converts raw fuel into tractive motion at the wheels • Includes engine, transmission, exhaust treatment and control systems • A complex combination of interacting sub-systems under computer control with multiple actuators and sensors • Fundamental to vehicle performance, emissions production and fuel consumption (CO2) Matlab/Simulink Hierarchical Software Tool for Optimisation and Model Development A Typical Vehicle Powertrain Virtual Engine Hardware in the Loop Calibration Vehicle & Transmission Control Bespoke Modelling Reality Powertrain Time Plan for Research Vehicle Baseline Testing on University of Bath Rolling Road Engine Testing a Combination of Real World and Virtual Environments Objective~“Develop an integrated approach to Powertrain design, performance optimisation and rapid calibration, through a simulation model based philosophy” “Lean Powertrain Development” The Problem, Current Industry Practice • Separate sub system development process- Little integration, compromised result • Simulation tools used intensively, but at sub system level – Little integration to achieve optimisation • New technologies selected off the shelf- Rarely optimised for required duty • Lead time to market compromised by multiple iterations during development Implementation • How about Hybrid Vehicles? • Future Vehicle powertrains may well include some hybrid components, but hybrid vehicles are not a total solution • Toyota Prius & Honda Insight are no more fuel economic than existing diesel powered vehicles • Vehicle performance must still exist when batteries are flat • Therefore demands original size engine • Start/stop capability a useful benefit • Some potential for regenerative braking • Strong hybridisation requires large mass addition (batteries and electric machines) Virtual Hardware Prototype Hardware Sam Akehurst, University of Bath, Powertrain & Vehicle Research Centre Funded Under EPSRC Project Codes EP/C540883/1 & EP/C540891/1 Real World Hardware • The Optimisation Task • Targets- Minimise fuel consumption, and meet emissions targets and driver performance expectations • A multi dimension problem, many complex interactions and trade-offs to consider • Considerable number of mechanical constraints • Potential to use Multi Objective Genetic Algorithms • Why Diesel? • CO2 Targets, Fleet Average of 140g/km by 2008, 120g/km by 2012 • Currently 169g/km, of which average diesel is 25% lower than average gasoline vehicle • Results of this research will transfer to gasoline • A Novel Approaches to Virtual Prototyping • Utilising Hardware in the Loop (HIL) • Real time models of powertrain components can be operated interfacing with existing hardware in many combinations • New technologies will be prototyped either in software or through novel emulating hardware in the test cell environment • Expected Project Outcomes: • A practical method for complex Powertrain design and calibration • A more integrated and better optimised Powertrain solution • Reduction of intensive experimental and modelling procedures • Predictive methods developed for understanding the effects of emerging hardware • Reduction in final product complexity