MaMeK: a wide-angle dynamic holographic projection system for human-vehicle communication

Although being a rapidly developing field, autonomous driving already starts facing challenges in terms of safety for the humans surrounding the vehicle, like pedestrians or cyclists. The communication between the vehicle and its close proximity could overcome such issues, e.g., by projecting patterns onto the street to inform about actions which will be taken by the vehicle: turn, stop… Such a projection system is required to yield a large projection pattern in order to cover the whole circumference of the vehicle with few projectors only, dynamic content to be adapted to the traffic situation, and a very high brightness for daylight situations. We propose a high-performance solution based on holographic projection. It utilizes the collimated beams of four laser diodes that are independently shaped by one reflective, high-definition LCOS Spatial Light Modulator. A compact optomechanical design includes telescope optics to enlarge the projected fields, which are stitched laterally to achieve a 0.3 x 1 m² projection separated less than 50 cm from the vehicle. Image stitching as well as distortion correction is applied in the hologram generation algorithm. In result, we achieve the projection of dynamic patterns (above 60 fps) that can surround the full perimeter of the vehicle with a brightness in the 1-10 klux range depending on the projected pattern.