Integrated Digital Sensor Interfaces: Technology That Saves Lives in Vehicle Safety Testing

In the automotive industry, vehicle testing plays a vital role and is a necessary procedure to verify key indicators such as vehicle power, tires, durability, and safety. Before mass production of vehicles, manufacturers must ensure that the entire vehicle and its components have high safety and adaptability. Vehicle manufacturers and original equipment manufacturers (OEMs) generally spend a lot of time testing the main physical parameters and improving current vehicle research and development by evaluating these parameters.

In vehicle testing, the first thing to do is to ensure the accuracy of the measurement data. To this end, the test configuration and test equipment must meet strict standards. As a Swiss family-owned company, Kistler has been developing its own sensor technology since 1959. Through this pioneering technology, data such as pressure, force, torque, acceleration, etc. can be easily and accurately collected. Today, the overall measurement and data acquisition solutions developed by Kistler have been widely used around the world.

Kistler DTI technology ensures efficient crash testing at Continental International Safety Engineering

Sensor technology: a must for dummies in vehicle safety crash tests

Particularly in terms of vehicle safety, crash tests provide insights into the structural and energy absorption properties of the entire vehicle and its components. In addition, crash tests indicate the potential effects of a crash on the vehicle's occupants. The series of tests that verify vehicle safety uses crash test dummies with special sensors installed inside. These sensors collect data before, during and after the test vehicle is subjected to a crash, which is used as a basis for important future conclusions about the vehicle's safety. As vehicles become more complex and digitalized, more and more measurement channels are needed, both in the vehicle body and in the dummies. In the early 1990s, 250 analog measurement channels were used in crash tests, while today more than 600 sensor channels are often required. This also leads to another problem: the test setup is becoming more complex, as there is less and less space in the vehicle for installing sensors.

As the number of analog sensors measuring various test indicators increases, more cables must be installed for power supply and data transmission. As a result, test installation work becomes extremely time-consuming and costly. In addition, too many input channels also increase the risk of data acquisition errors and omissions. To minimize errors and installation time, Kistler deploys its own unique digital sensor interface (DTI) technology.

Single cable design makes vehicle test installation faster and more efficient

A new era of process efficiency for manufacturers and suppliers in the automotive industry is opening up. What makes this possible is an intelligent bus for digital data transmission. Each bus supports up to 12 measurement channels per connection port. All signals from different sources are converted into a digital output signal by digitizing modules (DiMods). We integrate these DiMods directly into the sensors in the mannequin or deploy suitable Kistler DTI integration solutions.

The collected sensor data is then transmitted to the Kistler DTI central data logger in the dummy and then to the COMBox/KiHUB data interface device via Ethernet. All DTI systems in the vehicle are connected to the central network via this device. The highlight of this solution is that only one cable is needed to synchronize data, trigger tests, and power supply. The cable starts from the dummy and ends at the on-board data logger. The logger is usually connected to the host computer via a traveling cable, etc.

From analog to digital measurement data, the DTI recorder connects everything via just one cable

The DTI data logger collects digital measurement data from the sensor and transmits the data to the data interface device via Ethernet.

Integration of DTI technology into existing processes at Continental Safety Engineering

Since 1993, Continental Safety Engineering International GmbH in Alzenau has been working with Kistler on data acquisition for trolley tests, crash tests and head impact tests (the head here refers to the Free Motion Head Model, or FMH). As a subsidiary of the international technology company, Continental has its own testing and development center in Lower Franconia, Germany. Since its establishment in 1992, the center has completed about 300 series development projects, more than 6,000 crash tests and more than 200 simulation projects. The development area of ​​the center conducts about 550 trolley tests and 450 real-car crash tests every year. "Given the large number of tests to be performed, we wanted to upgrade the test equipment with the latest technology to ensure process efficiency and accurate and reliable measurement data. The test requirements are now becoming more and more demanding, and there are more and more test points on the vehicle," said Thomas Wild, head of the company's measurement and video technology team.

Kistler's DTI technology offers a simple solution for the comprehensive modernization of customers' existing crash test measurement equipment. In 2015, Continental Safety Engineering commissioned Kistler to expand its data acquisition system (DAS) and upgrade the existing sensor system in the dummy to the new DTI technology.

At the beginning of 2015, Kistler first integrated DTI technology into 10 existing H3 dummies, and at the end of the year, the WorldSID dummies were upgraded. The difficulty of the former lies in integrating the technology into the existing processes and infrastructure. With analog measurement technology, each sensor must be manually plugged into the data acquisition system, which takes a long time to install and has a high possibility of errors. For data acquisition of the on-board system, Continental chose Kistler's latest technology - KiDAU data logger. Not only is there full compatibility between the original hardware and the newly integrated hardware, Kistler also modified and expanded its CrashDesigner software to meet the needs.

High-quality crash testing of the future

Since DTI can be installed in all dummy models, including the THOR-M, Continental can safely combine a large number of different devices, including new hardware and already tested hardware, without having to convert all technical equipment to the new technology, which saves the company a lot of time and money. Thomas Wilder sums up the cooperation between Continental and Kistler: "In this project, Kistler used its expertise and many years of experience in vehicle safety to convincingly prove that DTI technology is the most suitable measurement system on the market for installation in dummies. Kistler knows what is important and what is not important in highly complex crash tests, especially when testing with DTI technology. Therefore, we are confident that the crash tests we carry out will meet the highest standards not only now but also in the future. In addition to providing precise measurement data, Kistler sensors are also very safe and durable. For us, DTI technology and sensors from Kistler are a perfect match. With this in mind, the two parties are already discussing some future projects in depth."

Continental benefits greatly from Kistler's adaptable measurement technology, which not only improves reliability and data quality, but also reduces space usage. A single wire leads from the dummy, and the wiring work is much less. The advantages of this technology are reflected in two aspects: less time is required for test preparation; the system has fewer problems, and the measurement accuracy is also improved.

Use DTI technology to test vehicle power, tires, and durability

More than 40,000 DTI channels are used today in vehicle safety crash tests. The installation work required for series tests for testing vehicle dynamics, tires and durability is time-consuming and expensive, both on the test bench and for in-vehicle applications. At its technical center in Wetzlar, Kistler uses its accumulated vehicle safety expertise to continuously develop proprietary DTI technology that meets the stringent requirements of vehicle dynamics and durability testing.

Automatic sensor detection makes test setup easier than ever. KiCenter (Kistler's measurement software) automatically detects the installation position, calibration values ​​and relevant physical parameters, which can be configured by the customer in the GUI (Graphical User Interface). It is safe to say that this function not only makes efficient use of time, but also maximizes process reliability.

Intelligent bus interface design of Kistler's DTI technology simplifies installation work for vehicle safety tests

For example, for the braking path measurement of ABS brakes specified in the DIN 70028 standard, Kistler provides a perfect overall measurement solution based on its DTI technology. The solution consists of sensors, triggers, DTI recorders and KiCenter measurement software. The "one cable solves everything" design ensures that all connected sensors can complete end-to-end configuration and other test installation work quickly and efficiently through KiCenter. The measurement software can guide users through the entire test, so that users can fully focus on their work and save valuable time.

DTI sensor technology maximizes ABS braking process efficiency

Interconnection reduces costs: fewer measurement errors and shorter installation time

Reliable testing and cutting-edge measurement technology are essential foundations for optimizing vehicle development and manufacturing. Test configurations should be as simple as possible to ensure complete acquisition of measurement data. In vehicle safety testing, power testing, and durability testing, Kistler's DTI technology with a "one cable solves everything" design not only improves measurement results, reduces material costs, but also shortens test time.