A method for estimation of average engine fuel maps: power measurements at drive wheels

Download
Ulf Hammarström
Mohammad-Reza Yahya

There is a need for engine maps in order to simulate fuel consumption for road vehicles after mechanistic principles. In an engine map, fuel consumption (g/kWh or g/s) is expressed as a function of engine speed and engine torque. In general, there is a considerable lack in engine map data. The main purpose of this study is to develop a tool for assigning any segment of the car fleet a representative engine map. Two methods have been developed: a "matrix" method based on interpolation of measured values to a uniform grid of values and a "function" method based on regressions. The function alternative is in focus in this documentation. The estimated functions have a high degree of explanation (>0,97). On commission of the Swedish Road Administration, Rototest AB has measured stationary fuel consumption and exhaust emissions for more than 400 cars of different year models. If this data set could be used in mechanistic simulation models one could expect increased representativity in different applications. Advantages with the Rototest method, where the engine at measurements is mounted in the vehicle, could be increased representativity and lower costs compared to motor test bench, which is the traditional method for engine map measurements. One problem with the Rototest data set is that engine torque or power, which is needed in an engine map, is not available, only the output power from the final gear box. In order to estimate crankshaft torque, transmission losses need to be estimated.

LATEST NEWS


2018-06-13

International Conference on Electric Road Systems starts today

Electric Road Systems (ERS) is a relatively new concept with many initiatives on the way. To learn from each other and stimulate new collaborations the Swedish Research and Innovation Platform for Electric Roads arranged the first international conference...


2018-05-18

Same survey of road users’ attitudes in 50 countries

At the Road Safety on Five Continents Conference, RS5C, one entire session presented a large survey of road users' attitudes in 38 countries. Results show large differences between countries in many areas, both regarding behavior and attitudes. A new survey...


2018-05-17

Good results with alcohol interlock program according to Swedish study

An alcohol interlock program makes it possible for drink driving offenders to continue their everyday lives. In a Swedish study most of the participants were satisfied with the program and experienced improved health. They also reported drinking alcohol more...


2018-05-16

Traffic safety in the spotlight

Today the Conference Road Safety on Five Continents (RS5C) opened in Jeju Island, South Korea. More than 220 participators have come from all over the world to present findings and learn about traffic safety. Dr. Young Tae Kim, Secretary-General of the...


2018-04-17

VTI will develop simulators for ambulance staff

VTI has initiated a pilot study for paramedics with the Centre for Teaching & Research in Disaster Medicine and Traumatology and Linköping University. The aim is to give ambulance staff the opportunity to practice critical medical tasks in a moving vehicle in...


2018-04-12

Unique electrified road opens in Sweden

The world’s first electrified road recharging the batteries of cars and trucks while driving opened in Sweden. The Swedish Minister for Infrastructure, Tomas Eneroth, was at the formal inauguration of the electrified road on April 11, 2018. VTI is one of 22...