Transcript Slide 1
“Lean Powertrain Development” Objective~ “Develop an integrated approach to Powertrain design, performance optimisation and rapid calibration, through a simulation model based philosophy” A Typical Vehicle Powertrain 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 Matlab/Simulink Hierarchical Software Tool for Optimisation and Model Development Virtual Engine Calibration Virtual Hardware Prototype Hardware Vehicle & Transmission Control Bespoke Modelling Hardware in the Loop 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) 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) Real World Hardware Reality Time Plan for Research 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 Powertrain 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 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 Vehicle Baseline Testing on University of Bath Rolling Road 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 Engine Testing a Combination of Real World and Virtual Environments Sam Akehurst, University of Bath, Powertrain & Vehicle Research Centre Funded Under EPSRC Project Codes EP/C540883/1 & EP/C540891/1