Fraunhofer-Institut für Mikroelektronische Schaltungen und Systeme IMS

At the Fraunhofer IMS, the topic of LiDAR is depicted in its entirety. The basis is the development of highly sensitive CSPAD detectors for LiDAR cameras. In addition, camera systems are being developed with which the performance of the detectors and the methods developed by the Fraunhofer IMS for hardware-related signal analysis can be investigated.

Flash LiDAR Camera Owl
© Fraunhofer IMS
The Flash LiDAR Owl camera was developed to evaluate the performance of the CSPAD sensors manufactured at Fraunhofer IMS and to test novel algorithms for signal processing under realistic measuring conditions

Distance measurement of several people and objects at different distances to the camera in an underground car park
© Fraunhofer IMS
Distance measurement of several people and objects at different distances to the camera in an underground car park

The three-dimensional detection of the environment or of objects is of crucial importance in applications such as driver assistance systems, autonomous vehicles or industrial robotics and measurement technology.

The lidar (of English. L ight D etection A nd R was concerned) measuring principle is based on the determination of the duration between the emission of a laser pulse and receiving the reflected light. Since the speed of light is known, the distance to the reflecting object can be determined directly from this duration. In LiDAR cameras, many of these measurements create a three-dimensional image of the environment. Both scanning methods that capture the environment point by line or line by line, as well as so-called Flash LiDARs, which illuminate the environment with a single laser pulse, are possible.

Basic elements of LiDAR systems are:

Transmitter : a laser beam source emitting short pulses of light. Typical wavelengths are 905 nm or 1550 nm .
Receiver : Highly sensitive sensors are used to detect the light reflected from an object.
High-resolution time circuits that determine the elapsed time between the transmission and the reception of the laser pulse.
Signal processing algorithms that perform signal filtering operations and calculate the distance to the object.
Especially in complex, dynamic scenarios, which often occur in traffic, LiDAR cameras rely on fast, reliable and cost-effective detectors. Services provided by the Fraunhofer Institute for Microelectronic Circuits and Systems (IMS) in connection with LiDAR include the development and manufacture of integrated detectors and readout circuits, from signal processing to system simulation and the development of LiDAR cameras. Core competence is the development and production of highly dynamic CSPAD detectors, These are SPAD (for single-photon avalanche diodes) with integrated read-out electronics, which are manufactured in a standard CMOS process. This allows cost-effective production of the detectors and a compact design and is particularly advantageous in applications that require high resolution.

In addition to detector development, the expertise of the Fraunhofer IMS also includes signal processing and research on adaptive circuits that allow the detectors to be adapted to the intensity of the background light and thus significantly increase the dynamics of the measurement. Furthermore, the Fraunhofer IMS will develop easy-to-use Plug & Play LiDAR camera systems such as the Owl LiDAR camera, which will be used to evaluate the performance of the CSPAD sensors and the algorithms developed in realistic and application-specific measurement scenarios. In addition, customer-specific modifications can be made to the cameras. This will give laser manufacturers, for example, the opportunity to test their laser diodes in LiDAR applications. Other typical cooperation opportunities are feasibility studies.