[ ] SIENA

Stimulation Initiative for European Neural Applications

Esprit Project 9811



Case Studies of Successful Applications



Qualification of Shock-Tuning for Automobiles.

Company Background

Comar International B.V. is a small mechatronics company located in the center of the Netherlands and operating on the international, highly competetive, automotive testequipment market. The company has only limited internal research resources.

The problem

Among the many factors that influence the safety of driving on public roads is the technical maintenance level of the automobile itself. A regular car inspection has therefore become a law-enforced reality. At the inspection site, a number of dedicated apparatus is installed, on which a standardardized probing of the safety limits is performed. To a lesser degree this also involves the safety margins or, in other words, the comfort of driving. The correct tuning of shocks has a major impact on the driving characteristics of an automobile. However, the shocks take effect in combination with suspension stifness and tyre hardness and hence current testmachinery can not reliably distinguish between them. As effect it is estimated that at least 30% of the automobiles of the public roads still have inferior shocks, which potentially can be the cause of accidents. Several attempts have been made in the past to isolate the effect of shock-tuning but to no avail.

Neural network application

Measurement data have been taken from a range of vehicles under different maintenance conditions on an existing apparatus. After establishing that the information content suffices for neural processing, a neural feedforward network has been trained by error backpropagation and validated in the InterAct environment to approximate the shock characteristics. This prototype function is ensuing mathematically optimized for robustness and stability. The final network is currently introduced in a new market offering to be sold on an international scale.

Benefit

Neural networks allow a real-time correlation of measurement data to prototype with various signal processing algorithms. In this manner a cost-effective weighting algorithm has been found that adapts easily to different car types and operating conditions. The mixed approach with neural rapid prototyping and classical mathematical optimization techniques has proven to be very effective for modelling non-algorithmic problems.

Generalization

The transition in technology base from mechanical to mechatronical through the introduction of microsystems brings more than a simple cost reduction. It also brings a sensitive set of data channels carrying influences from a large number of sources. Instead of filtering out the signal as desired by design, the quest is for a design in which many signals can be viewed in combination. In conventional technology, mechanical micromachining has forced diagnosis on a one feature per machine basis. Advances in microelectronics allow for combined sensory systems in which the careful construction is replaced by novel signal processing and optimal adaptivity by in-product training.

Contact Person

Dr.Ir. J.A.G. Nijhuis, Rijksuniversiteit Groningen, Dept. of Computing Science, P.O. Box 800, NL-9700 AV Groningen (The Netherlands)