Simulation Software

Gilles Schaefer is the primary designer of the following software packages:

In general, there is an interaction between programs and conceptual design. Car design uses digital simulation where program design formalizes and validates the comprehension of car dynamics.

Lap Time Simulation

Renault Sport, Peugeot Sport, Citron Sport, ORECA, Snobeck, and Nissan Motorsport all use TOUR to compute racecar performance. For example, TOUR was responsible for shifting the Peugeot 905 towards high down-force configuration, which was more effective for the full range of world championship endurance races.

3D Vehicle Dynamics

CALLAS and PROSPER are vehicle dynamics programs driven by four major ideas:


callas_reel callas_simul

Software CALLAS & PROSPER are distributed worldwide by OKTAL.

Hereunder, some videos about interesting simulations.

This test consists in driving with a passenger car to a gradually increasing speed between skittles, what becomes harder and harder; we notice the slightly understeering behavior at the beginning, then very to oversteering with effect of contra-steering, well-known in rally, with a strong back sliding.

The vehicle MODIX was developed for the DGA-ETAS to be a laboratory rolling connections on the ground bond of one 8x8. Every wheel is endowed with possibility of load, drive, braking and lock independent. A controle commands computing allows to feign the various configurations imagined for future 8x8. This video was presented to the conference ISTVS of Ferrara in 1997.

A research work on the stability of articulated Heavy trucks Tracteur+semi-remorque in liquid freight was made under financing PREDIT. The purpose was to understand and to propose improvements. A model of simulation for the vehicle and the other one for the liquid freight were developed, then coupled according to the principle of the Outside Strength. Tries of validation were made on real vehicle. Two publications arise from it.

The study of the dynamic behavior of motorcycles is rather delicate, because little stable without corrective actions of the driver.

Another reason of the slightest knowledge of the domain " 2 wheels " compared with the domain " 4 Wheels " is that the industry motorcycle is appreciably smaller than that of the automobile.

The work presented here aims at quantifying the potential of deceleration of a motorcycle according to its geometry.

By leaving of at the top and to the right: Rev-counter, report hired on white bottom, speedometer bar of position of accelerator, brake and clutch Position of the handlebars The upper left red figure is the immediate value of the accelerometer bound to the suspended mass. Text with the numerical values of time outstrips speed On grey bottom, bars give the rate of request longi in green and side in red of the tire: the front is not saturated.

The wave test, at constant spatial frequency, but run at variable speed ; we can see the calm range, then the resonance range and finally the filtration range, with all the non linearity (wheel lift, traction loss, suspension bump stop....

The convoy of the truck and the trailer is a tire test bench for an big plane tire, located in the middle of the trailer. The wheel is progressively steered to generate a side force, and the convoy stability is altered.



LIS and LECOS are both original suspension design programs. They do not simply compute from suspension points to wheel kinematics v. steering and v. suspension travel, but also function as back-solving from the target parameters towards the free values of the point coordinates.

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