Abstract
KEYWORDS – AUT, Labview, Software, Hardware, compactRIO
ABSTRACT
The Automated Universal Tribotester (AUT) is a reduced scale brake dynamometer developed by the Institute of Dynamics and Vibrations. This system is advantageous in comparison to full scale brake dynamometers in that there is less influence from the test systems themselves. The setup can be used for high frequency analyses of the coefficient of friction, and investigations of the boundary layer between brake pad and disk, along with the associated NVH behaviors. Additional devices, which are also implemented in the AUT, can be used for optical and topographical investigations of the disk and pad. [1,2]
The focus of this paper is the software development of the AUT controller. For the AUT controller, a compactRIO from National Instruments was used. It has several analog and digital IOs with varying sampling rates. The major tasks of the system are the controlling of all actuators and data acquisition from all sensors. The controller uses an FPGA for simple high speed operations. It is the interface between the hardware and the software. The compactRIO also has a real time controller for coordinating the measurement and storing the measured data. The AUT software has a robust and modular design, which guarantees reliable repeatability. The software’s major tasks of controlling and measurement can be divided into two parts: communication with the hardware (FPGA) and real time controller software. This paper provides an overview of the software concept and shows how a user can interact with the AUT.
Based on the results in this paper, further developments are possible. Along with the existing measurement devices, features such as brake applications with constant friction power, combined load and speed ramps, and in-stop braking with virtual inertia can be implemented with the AUT software.