Abstract
KEYWORDS - Driveability, Truck, Measurement, Powertrain, Quality
A fully automatic real-time tool is commercially available for analyzing and scoring vehicle drive quality, also know as "Driveability". This system from AVL uses its own transducers, calibrated to the response of the human body; to measure the forces felt by the driver, such as acceleration, shock, surging, vibration, noise, etc. Simultaneously, the vehicle operating conditions are measured, (accelerator pedal angle, engine speed, gear, vehicle speed, temperature, etc). Because the software is pre-programmed with the scores from a multitude of vehicles in each vehicle class via neural networks and fuzzy logic formula, a quality score with reference to similar competitor vehicles is instantly given.
Since pickup trucks have powertrains that are sized for their heavy load condition, improvements in fuel economy and CO2 emissions require fundamental efficiency increases rather than engine downsizing. Reduction of engine, transmission, and driveline losses using emerging technologies such as GM´s Active Fuel ManagementTM (cylinder deactivation), increased number of transmission gears, early shift patterns, and controlled low-slip torque converters generally result in more transitions which need to be managed as seamlessly as possible.
This paper describes the process of adding the capability to assess these transitions in the real-time driveability tool and gives vehicle development examples how the tool supports the increasing effort in such calibration tasks. Data will show how these technologies were added to the vehicle with little or no degradation to the driveability. In addition, the paper includes a general overview of further tool uses in several stages at General Motors (GM).