Measurement in Experimental Cars Using Realtime Computer Systems 880476
A system for digital data acquisition and processing in experimental cars is presented.
Signal conditioning is performed by sensor specific electronics and a Kayser Tbrede K 2400 data acquisition system. A HP 1000 computer system, including a 20 MB hard disk, a grafie terminal and a streamer tape, controls signal preprocessing, sampling and storage. The software package developed offers a user friendly interface based on menues, soft keys and dialogue files. Desired system configurations like signal conditioning, selection of channels (up to 48 analog and 16 × 16 bit digital), sampling rates (0....250 Kc/s), storage medium (4 MB external RAM, 2 MB HP 1000 RAM with full sampling speed or 10 MB on hard disk with a maximum sampling rate of 20 Kc/s) as well as recording trigger and recording time may be read from external files. RAM or disc stored data are transfered on a digital streamer tape (64 MB).
The software modules for signal postprocessing of stored data facilitate data sorting, digital filtering, arithmetic signal processing and graphic display with physical scaling. They can be run either in the test car for immediate evaluation of the experiments or on the laboratory HP 1000 system. Similarly the test engineer can prepare his experiments in the laboratory by editing files. The system in the test car is set up to the desired configuration by reading the transfered files.
By means of test programs the whole measuring chain of each input channel from the sensor up to the digital data output can be quickly checked to ensure perfect operation.
Using the HP 1000 A 900 computer with it's real time operating system one is not restricted to do only data acquisition since the comupters speed offers the potential to implement a variety of real time control algorithms for the development of electronic car control like anti-lock braking, traction control etc.
The system has been proven to be very suited for the harsh environment of test cars.