emv GmbH has provided a turnkey EMC measurement system for the BMW Group and shared in the conception and planning of the whole project.
The Challenge
A modern automobile requires a complex network of electronic systems. These control essentials such as the motor and transmission as well as various safety and comfort features such as dynamic stability control (DSC) and satellite supported GPS navigation. The problem is that these systems can affect each other or be disturbed by electromagnetic signals from the surroundings. The automobile manufacturers must detect, diagnose, and correct such system problems by means of EMC testing.
Until recently, in the existing BMW Group EMC hall, most EMC tests could only be performed on stationary vehicles. So BMW decide to build a state of the art EMC absorber hall at their research and innovation center in Munich.
The Task
The new EMC hall should permit BMW engineers to test networked systems with realistic dynamic vehicle situations. Antennas were needed to provide strong high frequency signals and these had to be dynamically oriented and moved in the hall and brought as near as possible to the vehicle on the turntable (11 m diameter). The desired test scenarios also required a large unimpeded floor area in the measurement hall. All this had to be combined with very efficient test sequencing and ease of measurement.
The Solution
The task was solved by attaching the flexible antenna complex to the roof of the hall. The antenna is exactly positioned relative to the tested vehicle, using six-axis remote control. It can be lowered from the roof as near as wanted to the vehicle. This leaves the floor free for simulation of all sorts of driving situations.
emv solved the requirements for efficient ergonomic measurement by various means. The high level of automation of the Measurement system makes the difference. The engineers can now carry out a set of tests according to BMW standards just by pressing a button. The antenna configuration can be automatically set according to vehicle type. The "RadiMation“ software from Dare!! organizes this. For instance, the software organizes the integration of dynamometer, turntable and antenna controller from different manufacturers. For immunity tests, the frequency range 20 MHz to 4 GHz, can be measured without changing the antenna configuration.
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The low frequency range is covered by a 200 Ohm stripline solution. This was developed by specialists from the EMC department of the BMW Group and has been patented. It can be set up and taken down again within five minutes, and takes up little space when packed together.
EUT monitoring lets the test engineer watch and document the behavior of the test object while checking out the fieldbus in the vehicle. A modular concept permits communication with different fieldbuses (e.g. CAN, LIN) via one base cable. A Car Radio Dummy is used to check the correct functioning of measurements of radiated interference. The vehicle antenna receives the radio signal, and the Car Radio Dummy sends it back to the measurement receiver in the measurement controller, where it is verified. Radio signals in the frequency range 100 kHz to 4.2 GHz are generated by semiconductor amplifiers from AR. A microwave rack with 500 watt TWT amplifiers and filters for harmonic suppression covers the frequency range 2.5 GHz to 18 GHz. A GPS simulator supports simulation of realistic routes. Real GPS signals and transmissions from real radio stations can be received by an external antenna and communicated into the hall.
The Result
The new EMC hall is the first of its kind in the world. It makes possible the testing of driver-assistance systems under reproducible lab conditions in moving vehicles. Curbstones, parking spaces, passing vehicles and specific routes can all be simulated in order to test electronic systems under realistic conditions.
The project was completed in 2 years. "The deciding factor for the success of this joint project was the collegial cooperation between BMW experts and our project team", stated Markus Krautbauer, project manager at emv GmbH.
 further information on turnkey EMC
 Measurement Systems |
Automotive Industry: BMW Group 
Automotive Industry:
Volkswagen AG
