Automotive on Test

David Owen, Business Development Manager, Pickering Interfaces Ltd, Essex, United Kingdom


PXI fault insertion and battery testing for automotive applications

Pickering Interfaces is a UK-based company manufacturing advanced switching and instrumentation equipment for the electronics industry. The company's products are used worldwide in applications such as automotive, aerospace and defence. Our test & instrumentation products are used in everything from mobile phone handsets to the space shuttle, weapons systems to television sets. Thanks to an expanding range of PXI modules the PXI standard is well positioned to meet the new tests demands created by modern vehicles with high electronics content. Recent product introductions have further expanded the ability of PXI to address the new user demands.

Testing the new generation of controllers that are designed into modern vehicles can be particularly demanding, and these tests are required to be largely automated so that a wide variety of scenarios can be tested quickly in a reproducible way under a variety of conditions.

Pickering Interfaces most recent introduction for automotive test applications is the 41-752 Battery Simulator, designed to aid the testing of high voltage battery stacks used in electric vehicles. The 41-752 module contains 6 battery simulator channels each capable of generating up to 300mA. A typical configuration of 16 modules in a PXI or LXI modular chassis allows users to emulate a 96 cell battery stack in a single chassis with a compact form factor and the choice of a PXI or LAN based control. The 1 kV isolation barrier permits the battery stack to generate high stack voltages without fear of breakdown and a safety interlock feature protects users from accidental contact with the high stack voltages generated. Fault Insertion testing is also a crucial issue in automotive applications; controllers must react in a safe way both when they receive accurate data from sensors and faulty data because of defective devices. Pickering Interfaces has manufactured fault insertion modules for many years and continues to expand its product range with fault insertion capabilities on signals from 2A to 40A and voltages up to 200V. Solutions include both relay based switching and solid state switching, the latter being particularly important where long life under hot switching conditions and high current surges is required. Pickering Interfaces has the widest range fault insertion solutions available in the industry.

Many of sensors that the control systems rely on are variable resistors. The wide range of Pickering Interfaces resistor modules allows controllers to be tested with programmable resistors that mimic the changing conditions like temperature and mechanical strain. The controllers must respond to the varying inputs and provide appropriate output signals for the conditions. Programmability and the ability to operate with RTOS allow users to create the test scenarios required, be able to repeat the test sequences and enable rapid documentation of the results in support of controller design verification tests. The latest precision resistor products from Pickering Interfaces include modules that combine very accurate resistor settings with very fine setting resolution - allowing them to simulate a wide variety of resistor sensors, including RTD's and strain gauges, with state of the art accuracy at affordable cost. PXI product offerings will continue to expand to fulfil the new emerging demands for automotive test generated by the move to vehicles with greener environmental credentials.