Sensor solutions for automotive safety

For over 60 years, IABG, headquartered near Munich, Germany, has been carrying out safety simulations to monitor, evaluate and ensure the safe and smooth operation of vehicles, critical infrastructure and other assets. The company has been using specially adapted ASC acceleration sensors for vehicle and component safety tests since 2011.

ASC accelerators for innovative test benches

Both companies have been partnering with the automotive industry for many years. As a leading provider of vehicle testing facilities, IABG runs a state-of-the-art simulation center to evaluate and ensure functional safety. “This includes vehicles and transport systems, as well as newly developed high-tech components, systems and materials used in them,” explains Arbo Simon, Team Leader Vibration Tests and Earthquake Simulation at IABG.

"The technical quality and range of ASC’s sensors, as well as the company's great flexibility allow them to explore new avenues with us and to tailor solutions for our innovative test benches." These include:

• the HyMAS (Heavy Multi-Axial Shaker) vibration test rig for earthquake simulation and fatigue strength testing of objects weighing up to 14 tons,
• the LiMAS (Light Multi-Axial Shaker) vibration test bench with combined environmental simulation for specimens up to 1,000 kg, to test environmental impact such as wind gusts or the impact of objects, 
• the single-axis vertical vibration test bench SILAS-V (Single-Axis Shaker Vertical) to verify fatigue strength of mass-excited parts and components under vibration loads up to 80 m/s2 of specimens up to 500 kg in a 3.5-200 Hz frequency range and temperatures from -40 to 120 °C,
• the VESPA vertical dynamic structural test bench for the comprehensive, combined analysis of vehicle safety and reliability.

Low noise for low resolutions

"Across our settings, we analyze the impact of acceleration forces from less than 1 m/s² continuous vibration load up to 2,000 m/s² peak acceleration," says Simon. The triaxial capacitive low-noise (LN) accelerometers of the ASC 5711LN series feature very low noise density even in high measuring ranges of +/- 200 g. In combination with the MEMS-based sensors’ excellent response behavior, this leads to resolutions of only a few micro-g.

"ASC’s high-precision sensors register dynamic (AC) and constant, static accelerations (DC) and thus operate from nearly 0 Hz," the expert states. "In addition, their easy handling and installation, lightweight but robust housing, flexible usage between our test benches and DKD calibration are decisive advantages."

90 times gravity acceleration and rapid response

Truck and other commercial vehicle brakes can be subject to 90 times the acceleration of gravity in difficult road conditions. Using ASC sensors, the SILAS-V test bench can simulate similarly extreme loads. "The broad frequency spectrum at very high loads enables this," says Simon.

The VESPA bench combines tests for operational stability, fatigue, vibration and noise analyses of vehicles with conventional and electric drives. Customers can choose from a range of services from fatigue strength tests on car bodies and motorcycles to monitoring of electric vehicle behaviors, noise interference analysis and the simulation of ageing processes for vehicle components under harsh climatic conditions, solar simulation or the impact of simultaneous exposure to vertical forces.

The HyMAS shaker facilitates automotive load time history tests. While the LiMAS vibration bench is often used in product certification tests and to assess the safety of new components. "Therefore, we are frequently confronted with new challenges," Simon states. "Given our tight testing timelines, it helps when flexible partners like ASC can rapidly respond to customer needs.”

Stability and longevity

"Most applications are in the range up to 200 Hz. We use a sampling rate of over 2 kHz to be able to record all important data," he explains. The sensitivity of the sensors used plays a major role here. This also applies to operational stability. "As we aim for high availability of our test sites, accurate sensors of long, stable service life are essential."

"We have been using capacitive sensors from ASC since 2011, after discovering that the piezoelectric sensors initially selected were unable to deliver the desired quality," says Simon. "We then looked for a partner who was willing and able to support us with the right technical expertise and an 'open mind'.”

Read more: https://www.asc-sensors.de/en/company/case-studies