Endurance test bench for testing the function and signal quality of analog and digital high-speed sensors and actuators.
Online measurement for endurance testing of intelligent sensors
More and more intelligent sensor technology is being used in modern motor vehicles. The formerly "simple sensors", such as pulse switches, reed relays or other sensors with partly analog output signal, are nowadays mostly replaced by sensors, which directly digitize the sensor signal and transmit it by a digital bus protocol. The advantage is obvious, the sensor has a self-diagnosis with error output as well as a checksum during transmission, which allows an extended diagnosis and localizes error causes on the vehicle faster. In addition, the serial data protocols usually also save on cables. Especially when the data is modulated onto the supply lines. This shrinks the thick wiring harnesses.
But these sensors also require much more effort in test engineering. Where testing with earlier sensors was limited to measuring analog signals at relatively low sampling rates, today digital bus protocols must be read in and verified. This means reading in the bus protocol through standardized digital modules, evaluating the sensor signal, which used to be analog, and also evaluating the data protocol itself. So the data stream itself (bit length, level, word length, times, periods ...) has to be evaluated, too, because the sensor is specified with these data.
This development is an endurance test bench, which monitors 20 of these sensors in parallel and in operation. The sensors are wheel sensors for ABS systems and for monitoring vehicle dynamics.
As described above, all relevant characteristics of the sensors are checked, such as the bit stream in the digital protocol: Times for bit lengths, word lengths, period durations as well as the analog values for voltage level - high/low level, error level as well as the protocol itself with error words, checksums and data selection.
For this purpose, this protocol is not randomly examined, but every single bit is checked online, for each of the 20 sensors. An expansion to more than 20 sensors would also be possible.
In addition, the sensor signal itself is of course also evaluated, which means that drives are operated for wheel simulation and climate simulation chambers/environmental simulation chambers are integrated in which the sensors are located.
Since the data streams of these sensors are in the range of several 100 kBit to 1 MBit, very high analog sampling rates are required for signal evaluation. Our current system has a sampling rate of 50M samples, on each of the 20 channels! Besides, system is not only fast, but also accurate, level signals are measured to the millivolt and 1/10 µs and verified online!
The test software on the PC interface allows free programming of the test sequence and the endurance stress of the sensors. The parameters for the DUT stimulation, the climate simulation/environmental simulation as well as the measurement can be freely specified as well as pauses and waiting times in the sequence. The measurement data is stored online on the PC and can be further processed by standard software as usual.
The test concept can be applied many times to sensors of this type and to a wide variety of data protocols. With this equipment everything can be tested, which encodes its data digitally, and if all sensor data must be tested!
Scope of the test bench
Climatic simulation chamber/environmental simulation chamber
The drive for stimulating the sensors can be of any type (sensor-dependent), electronic rack with high-speed measuring system, powerful real-time system and industrial PC as operator interface and test data storage.
This test equipment is a classic example of one of our customized solutions. If you are looking for test equipment for your sensors/actuators, no matter if n-fold endurance test or single test/measurement station: We will be pleased to create a concept tailored to your needs and supply everything from one source. Development, design, manufacturing, assembly and service! Just give us a call or send us an e-mail.