EMC test for sensors and control units
Mooser provides EMC testing services for both sensors and control units (also known as ECUs) to ensure that both components function with complete reliability.
Sensors and control units in cars are similar to human sensory organs and brains and are equally essential. The ECU performs the same function as the brain, while the sensors record a variety of different visual, acoustic and other signals that are processed in the control unit.
EMC testing of control units and sensors
No reduction in the number of ECUs and sensors
We regard EMC tests of components and systems for high-voltage electric powertrains and automated driving systems as an important future market and we are currently investing a lot of time and energy in this area. But, of course, this does not mean that we are neglecting one of our core business activities: EMC testing of sensors and control units. We have been involved in this market segment for 40 years and have extensive experience and knowledge of the processes involved. Tests of this kind make up a large proportion of our order book.
This is something that is unlikely to change in future. Although electric cars do not have a gearbox ECU and although the starting process for an electric motor is much less complex than for an internal combustion engine, electric vehicles are equipped with an inverter which has a large number of electronic components. It is true that the move to large, centralised domain computers will result in a reduction in the number of control units, but particularly intensive EMC tests will be needed because of the complexity of the components. In addition, it is likely that the number of sensors in cars will increase rather than decrease.
EMC testing requires experience
We carry out meticulous investigations of control units and sensors to determine their EMC emissions and immunity to external interference, both radiated and conducted. There are very few differences between the measurement methods and EMC tests for sensors and ECUs. The distinctions are between the different interference classes for emissions and immunity, which always depend on the manufacturer’s specifications and the safety-related functions of the control units and sensors. It is obvious that an acceleration sensor which triggers an airbag must be tested and evaluated much more thoroughly for EMC than a control unit for the seat adjuster.
Complex tests of ECUs
EMC test set-ups for control units are generally slightly more complex than those for sensors because control units are often activated via a laptop and a communication protocol. Also, they are frequently connected to peripheral components to form a system that is represented as a realistically as possible in the measurement chamber. We test ECUs with simulation data as well as with hardware data, depending on the customer’s requirements.
The type of control units that we test often at Mooser include those for the engine, gearbox, driving dynamics control system, restraint systems, bodywork and light functions. However, our test plans also include ECUs for climate control and exhaust gas treatment and increasingly for battery management and controlling electric powertrains.
Sensor tests: simpler, but equally challenging
The test set-ups for sensors are usually less complex. A two-wire connection for the energy supply and communications is often sufficient. We record the measurement data from sensors for acceleration, engine speed, rotary position, pressure, gas, radar and rain, together with cameras.
It is important to create a measurement environment that is specific to the individual sensor. For example, in the case of an EMC test on an engine speed sensor, the drive motor is powered with compressed air, because an electric drive motor could cause electromagnetic interference in the nearby sensor.
We cover (almost) all testing standards
CISPR 25, ISO 11452-X, ISO 7637-X and ISO 10605 are just some of the standards that we make use of every day, including in EMC tests of control units and sensors. In addition, manufacturers have their own factory specifications that are often based on the measurement methods referred to above, but with specific parameters or processes, for example. Mooser can test your ECUs and sensors on the basis of almost all global standards and manufacturers’ requirements.
With our many years of experience, we are also aware that every control unit and every sensor has its own special features, which need to be taken into consideration in the laboratory. For example, we position the highly sensitive acceleration sensors that are used for triggering airbags on measurement tables with heavy stone plates which damp vibration so that the sensors are not triggered by external shocks from outside the measurement chamber, for example caused by people walking past.
Testing and elimination of interference to meet customers’ requirements
Alongside the comprehensive EMC tests in our measurement chambers, we also offer other value added services. For example, to meet customers’ specific requirements, we can also test control units and sensors for EMC in the vehicle. If acceptance tests, manufacturers’ measurements or type approval processes do not immediately produce the required results, we can eliminate the interference from your components straight afterwards and prepare them quickly for the next measurement cycle. We can also work closely with you to produce complete test plans, something that we have been doing for decades.
We assign one competent employee to you as your contact person for all these tasks. He is responsible for handling the entire project, including planning and running the EMC tests, discussing the results and any other services you may need
Frequently asked Questions
Sensors are the sensory organs of a car. They record movements, obstacles, temperature, engine speed, pressure and many other types of information from the car and its surroundings. The data is processed in the control units and used for guiding the car, providing safety functions and reducing the car’s environmental impact. This is why it is essential that sensors and control units have effective protection against EMC.
In its EMC tests of control units and sensors, Mooser applies the same measurement standards and specifications as for other electronic components in vehicles, , such as CISPR 25, ISO 11452-X, ISO 7637-X and ISO 10605. In addition, we use manufacturer’s factory specifications that are often based on the measurement methods referred to above, but with specific parameters or processes, for example. We evaluate ECUs and sensors in our modern measurement chambers where we can run flexible tests on a variety of different components.
