High-resolution radars for the vehicle cabin Passenger detection from the drawing board to the application
Children forgotten in the car, nodding off at the wheel: for more safety, the sensors of a vehicle are increasingly looking inwards as well. However, until now the sensors have only detected that something is there. In order to be able to evaluate complex scenarios, a new generation of compact radar devices is needed. In the SICHER project, the Institute for CMOS Design at the TU Braunschweig is therefore developing the basis for reliable sensors that will even be used in autonomous buses.
Eight project partners are working together in the project “SICHER – Sensoric passenger detection for safe autonomous driving by radar”. Together they will bring a new generation of radar sensors from the drawing board to the application in three years.
They have two main scenarios in mind. Scenario one describes the sensor system in a car. A high-resolution radar then provides data on how tired or stressed the driver is. Likewise, this radar can detect the passengers and assess whether a child in need of help or an adult capable of acting has just been left behind in the car.
Scenario two focuses on autonomously driving buses. At every stop, the bus must recognise whether someone wants to get on or off. In case of doubt, the bus should also not wait for an emergency stop signal, but quickly recognise danger and stop.
In order for radar to detect not only objects but also tired drivers, however, a number of things have to happen. This process begins at the Institute for CMOS Design at TU Braunschweig. The researchers led by Professor Vadim Issakov are working on making radar sensors more efficient, more compact and at the same time standardised. To do this, they are relying on MIMO radars (multiple-input multiple-output) at high frequency. “MIMO is about interconnecting multiple radar modules for particularly high resolution. In addition, we are targeting the frequencies in the so-called D-band (116-148 gigahertz) in order to get the maximum bandwidth and, in turn, better resolutions,” says Professor Vadim Issakov.
Technologically, progress is not only characterised by ever more powerful frequencies, but also by the choice of the underlying material and circuit technology. Issakov: “In mobile communications, we have observed in recent years how the previous silicon germanium (SiGe) architectures have been overtaken by the CMOS architecture. Radar circuits were initially designed in gallium arsenide, an even more costly material, using HBT technology. In the meantime, SiGe and BiCMOS technology have taken hold here as well. If we now realise radar in CMOS in the SICHER project, that would potentially be a boost for an entire industry.”
About the project
The project “SICHER -Sensoric passenger detection for safe autonomous driving by radar” started in July 2023 for three years. The Federal Ministry of Economics and Technology is supporting the eight project partners with a total funding volume of around 10 million euros. The TU Braunschweig will receive a share of around 1 million euros for the sub-project “Design of integrated circuits for radar transceivers”. Other project partners are Infineon Technologies AG, Valeo Schalter und Sensoren GmbH, Gestigon GmbH, IHP-Leibniz-Institut für innovative Mikroelektronik, TU Hamburg, Silicon Radar GmbH and Adap GmbH.