Parameter acquisition on CAN bus

Acquisition of parameters on CAN bus on board of tractors

In defining the anti-pollution regulations for vehicles equipped with an internal combustion engine, the European Union has special study commissions that prepare the documents containing the limits to be respected and the methods for measuring emissions during the approval phase.

Periodically these regulations are updated introducing more stringent parameters and more accurate procedures in order to guarantee ever more sustainable environmental impacts; evidently from this we can not exempt the industrial vehicles and, in particular, the trucks of trucks and articulated lorries.
It is therefore essential to carry out specific campaigns to measure the current emission levels to decide what the objectives of the subsequent regulations are in order to combine the improvement of vehicles and the sustainability of development by the manufacturers.

These measurements are carried out at the Ispra Research Center and it was evident that it was very effective to combine them with the vehicle operating parameters already available in the communication channels between the various electronic control units (ECU).
In particular, it was decided to access the CAN bus to acquire useful data to characterize the vehicle dynamics in order to better interpret the measurements of pollutants and thus obtain a reliable model for the various situations of use; obviously this must be possible for all the drives made available by the Manufacturers without wasting time trying to obtain confidential information on what is implemented in the ECUs.

The solution was as simple as it was effective: by installing a PCMCIA interface card for the CAN bus combined with a software program for acquiring, displaying and saving the data developed in a personal laptop, the universality of the system was guaranteed by the use of the "DBC" files made available by the manufacturers as databases to identify and interpret the parameters transmitted on the CAN bus.

The staff of the Ispra Research Center therefore has a continuously usable system without changes to the software and without changing the working method despite periodically it is necessary to install the measurement chain on vehicles coming from different manufacturers.