Applications

Automotive

High-precision and extremely robust inertial sensors for automotive applications

Testing of cars, trucks, utility vehicles and motorcycles requires inertial sensors with high resolution as well as a robust and compact design. In addition to the capability of measuring very low frequencies and amplitudes, they must be resistant to vibrations and shocks, while taking up small installation space. Both accelerometers and gyroscopes, as well as inertial measurement units (IMUs) from ASC perfectly fulfil these demanding requirements. They have long been used by automotive manufacturers – in the development of active and passive safety measurments, such as driving comfort measurements and durability tests or in monitoring of vibrations and the analysis of vehicle dynamics.

Applications in the automotive industry

Driverless cars must be designed so that they do not endanger other road users. Whether analog or digital: Inertial measurement units (IMUs) from ASC continuously detect the position and motion of objects with high precision.

For high-precision position measurement, the analog ASC IMU 8 and digital IMUs HG4930 and HGuide i300 from Honeywell are the ideal solution. While the analog IMUs offer maximum freedom in the processing of data and a modular concept that enables application-specific configuration of the users’ IMUs, the digital versions feature numerous pre-configured settings that allow fast start-up using the Honeywell HGuide data reader software.

In addition, the HGuide navigators n580 and n380 allow the integration of GNSS signals such as GPS, GLONASS, BeiDou or Galileo by means of SBAS, PPK, RTK, single or double antennas.

ASC crash sensors included MEMS-based piezoresistive accelerometers, which are ideally suited for high-impact and shock applications with measuring ranges up to 6,000 g.The uniaxial sensors of type ASC 61C1 and ASC 62C1 are used for example in side and frontal impact tests.

The triaxial crash sensor ASC 76C1 combines low weight (12 grams) with a compact design (edge length 16 mm). All ASC crash sensors can be custom configured, for example with Dallas ID and EQX data. All axes of the triaxial ASC crash sensors can also be repaired individually if the case arises.

Without ASC, driving comfort measurements would hardly be possible. Our capacitive accelerometers help to identify undesired impacts and vibrations that could impair passenger driving comfort. Vibrations up to 12 Hz affect all human organs. Low-frequency periodic motions in the range of 4 Hz to 6 Hz can resonate within the body.

Such undesired disturbances are caused for example by tires rolling on an uneven road surface. Human reactions to total body vibrations are simulated and analyzed by means of ASC sensors in a frequency range below 100 Hz.

The triaxial sensor ASC 5511LN with its low frequency and measurement range and high signal-to-noise ratio is ideally suited for such applications.

A fast-growing segment in the automotive industry is the area of e-mobility. High-voltage batteries in particular represent a key technology in this segment.

Capacitive accelerometers from ASC measure the durability of batteries in shock and vibration tests. Extremely precise and reliable measurements are necessary for detailed analysis of the complex battery structure.
Accelerometers from ASC feature a very broad range of parameters, which makes them ideal for this application.

In addition to a wide frequency response range from 0 Hz to 7 kHz and an extremely durable design with shock resistance of up to 6,000 g, the accelerometers also have an especially high resolution of only a few μg. This enables the precise detection of even minimal vibrations and accelerations.

Modal analyses in the automotive sector require lightweight, high-frequency accelerometers that minimize the mass load of the test structures as much as possible.

The triaxial IEPE accelerometer ASC P203 is therefore used for modal tests, since it weighs only 6 grams (titanium housing) or 7.3 grams (aluminum housing) and is designed for shock resistance up to 5,000 g.

Both the triaxial IEPE accelerometer ASC P203 and the uniaxial versions ASC P101 and ASC P401 providing a very high dynamic range of up to 15 kHz (±1 dB) and are available with measuring ranges from ±50 g to ±2,000 g.

The goal of passive acoustics applications is to prevent background noise in automotive development. Tests are performed with different ride profiles, such as adverse weather routes or large cobblestones. The function developers detect background noise through their sense of hearing.

The vehicles themselves are equipped with accelerometers on the wheels and brake bodies to detect dynamic factors such as amplitudes of shocks or frequencies of vibrations.

With their compact design and robust housings that can withstand impacts up to 6,000 g, the uniaxial sensors of the Low Noise series (e.g. ASC 4311LN) and the triaxial sensors of the Medium Frequency series (e. g. ASC 5421MF) are particularly suited to achieve the right combination of large measurement range and high signal-to-noise ratio.

The spectrum of parameters enables not only measurements over a wide frequency response range from 0 Hz to 7 kHz. The sensors also feature a very high resolution of only a few µg.

Operational stability procedures are conducted to test the stability of vehicles and their components. To determine the behavior of components under real loads and especially under harsh conditions, fatigue tests and shock tests are performed on test benches or during test drives. These tests also use sensors that measure the effect of loads on the vehicle components. Since the components on the test benches are subjected to high mechanical forces, the sensors must be extremely robust and reliable.

Capacitive accelerometers from ASC are therefore ideal: The ASC 5521MF triaxial sensor features a wide frequency response range from 0 Hz to 7 kHz and excellent shock resistance up to 6,000 g.

For hard-to-access installation positions, on the other hand, the ASC 4111LN, ASC 4211LN and ASC 4221MF are ideal due to their compact and lightweight design (less than 3 grams).

Test bench applications require the use of accelerometers that fulfil long-term requirements. With their temperature stability, robustness, precision and reliability, both the capacitive Medium Frequency (MF) series from ASC and the capacitive sensors of the Low Noise (LN) series are ideal for these applications.

For example, the ASC 4421MF and ASC 5421MF sensors are designed for use at operating temperatures from -40 °C to +125 °C. The sensors ASC 4411LN and ASC 5411LN are ideal for measuring applications requiring maximum resolution, since they feature noise density of 7 µg/√Hz to 400 µg/√Hz.

During tests of vehicle components, a new process makes it possible to also determine the road quality during test drives. This process makes use of high-precision triaxial acceleration sensors of type ASC 5521MF.

These capacitive sensors are ideal for measuring low and medium frequencies, as well as conditions in which static and dynamic factors are superimposed. They enable the high-precision measurement of frequency-related factors of vertical vehicle acceleration and creation of specific fingerprints of the corresponding road segments.

The robust design of the ASC 5521MF also makes it highly resistant to repeated impact loads up to 6,000 g, which is ideal for monitoring uneven sections of roads.

The sensors are also valuable in vehicle monitoring. During test drives they provide manufacturers with detailed information about the loads to which the vehicle is subjected. The precision of the measured data is also very important as an input variable for deep learning algorithms. On the basis of a few significant variables these algorithms calculate the load and stress behavior in different areas of the vehicle. This eliminates the need for numerous sensors, which reduces manufacturers’ vehicle testing costs.

MEMS-based capacitive accelerometers with DC response from ASC are used for example in vehicle dynamics applications such as lane-changing tests, braking tests and driving maneuver tests. These high-precision sensors also feature low-noise as well as a robust and compact design. ASC sensors with protection class IP67 and IP68 operate reliably even under harsh conditions such as cold, heat, humidity and dust.

The models of the ASC OS series feature a hermetically sealed stainless steel housing so they can withstand the harshest ambient conditions. In addition, they are available in uniaxial, biaxial and triaxial versions, and in two technology variants: Low Noise (LN) and Medium Frequency (MF).

For yaw rate and roll rate measurements, as well as position and motion measurements and slippage tests, the gyroscopes ASC 271 (uniaxial) and ASC 273 (triaxial) as well as ASC 281 and ASC 283 are ideal. They feature excellent bias stability and low g-sensitivity.

The ASC IMU 7 is used in acceleration and angular velocity measurements of road vehicles. It combines accelerometers and gyroscopes and features a unique modular concept that allows custom configuration.

Custom solutions

Our development engineers are more than happy to take on the challenge of developing custom solutions for special assignments, even for low-volume series.

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Inquiry: Automotive

Anzahl Achsen
Sensortechnologie
Temperatur min - max
Sensorart

ASC 4221MF

Uniaxial, capacitive
Measurement range: ±2 to ±200 g
Noise density: 10 to 680 µg/√Hz
Frequency range (±5 %): DC to 2900 Hz

ASC OS-115LN

Uniaxial, capacitive
Measurement range: ±2 to ±400 g
Noise density: 7 to 400 µg/√Hz
Frequency range (±5 %): DC to 2000 Hz