Abstract
The automotive test and research laboratory staff of the automotive faculty is creating a platform for the development and analysis of braking systems. To this end, the laboratory is being equipped with a set of unique test benches at the highest state of the art, establishing the basis necessary to research new ideas, innovations and developments in the automotive sector. The most recent project is a series of test runs on a new brake-by-wire system.
The analysis of dynamic behaviour in respect to driving comfort and safety makes the use of test benches absolutely necessary, and can not be adequately replaced by computer simulation. Exact and representative simulations require precise knowledge of the characteristics of all relevant components, an endeavour which is highly complex, even impossible. While field trials are the most realistic, the achievement of reproducible results is difficult. Furthermore, individual variables of the tested system can not be readily changed. With the quarter-vehicle flat-roadway test bench, a platform has been created that enables the simulation of realistic driving dynamics with idealuneven road surfaces. Core piece of the test bench is a powered drive belt that exactly represents dry asphalt. Applied to the belt is a quarter vehicle, the unevenness of the road surface is represented by an exciter below. Mass inertia of the simulated vehicle is produced by the moment of inertia of the belt and can be varied by the belt drive. The test bench can simulate speeds from 0 to 150 km/h. The decoupled arrangement of the road and the road surface allows simulation of a variety of different driving situations. Equipped with electronic measurement devices and sensors at the highest state of the art, the precise and dynamic measurement of all relevant performance variables is possible. This test bench constitutes a platform enabling the dynamic testing of any given chassis frame, its braking system and their interaction, delivering reproducible results. The second test rig is a modified standard roller test bench enabling referencing not only simulation results, but also prototypes on actual cars. Here, speeds of up to 200 km/h can be simulated, with concurrent monitoring of all performance variables measured on the tested car. The speciality of this bench is its ability to measure vertical wheel forces online. The measurement devices in the laboratory combine the measurement of physical process values and digital communication with electronic control units (ECU).
The goal of these endeavours is the creation of a platform for the investigation and development of new braking systems, providing a gateway between the industry and the university which enables both parties to exchange knowledge, thus instituting a sharing process beneficial to research as well as practical application.
Keywords - Brake by Wire, Brake Testing, Automotive flat belt Test Benches, HIL, CAN Bus