Adaptation and Validation of a Stability Test for different truck types, making a comparative analysis of the driving dynamic characteristics.

Abstract

This thesis proposes a Test for vehicle stability, which encompasses maneuverability and turning circle reduction, implemented in a Three Axle Truck and a Two Axle Truck with a Semitrailer, analyzing the driving dynamic response, in particular on the angular positions, forces and acceleration, velocity and steering. The proposed test, can also be adapted into different truck models, given the dimensions to generate a unique test path. For this purpose, two different simulation models were built using dSPACE Automotive Simulation Models, which provides libraries of block diagrams that work in conjunction with MATLAB – Simulink, to generate complex vehicle models that incorporate different axle parameters, sensors and powertrain characteristics. In addition, different control functions are incorporated such as PID controllers, and Brake boosters, as safety factors under emergency maneuvers. The results of the stability test, are aimed to provide the maximum velocities on which a truck of more than 3.5 tons of gross mass, can effectively react on the road and avoid an obstacle, without losing balance, changing a lane, and then safety returning into the previous lane. The current normative of obstacle avoidance tests, makes a reference only to passenger cars, with the Moose test. Consequently, for the development of the current truck stability test, a research has been implemented on the driving dynamics in trucks, the driving safety systems, and on optimization methods used to test the safety of trucks.The enhancement of Active Safety requires detailed data on driver-vehicle interactions in critical driving situations, however this thesis is based on software-on-the-loop simulations, under an exchange and integration platform of dSPACE. The vehicle models used for the simulation of the driving behavior have been detailed enough to guarantee a good representation of the vehicle dynamics behavior, and at the same time, simple enough to guarantee the real-time capabilities for the driving simulator tests.