Solution Strategy

Hardware

In order to achieve that the TPU contains an independently exchangeable measuring unit, which can also be used stand-alone, an embedded solution based on the existing version of the TPU was designed. This device has its own housing that securely encapsulates the components relevant to measurement and calibration and all the connections necessary for operation (keyboard, GPS, printer, power supply line), and an additional connector strip that leads out all the connections necessary for communication with the main device. This component can be inserted into the main unit.

The main unit consists of a PC/104 format base unit and additional PC/104 expansion cards that are stacked on top of the base unit. These include a video codec that communicates with the PC via the PCI bus, and a board for video conversion and manipulation (overlays, picture-in-picture, …) that is equipped with two video inserter devices, referred to as legal inserter and user inserter. The LegalInserter converts the incoming picture format to the input format of the codec and handles inserts that are part of the stored video. The UserInserter processes the video image behind the codec, handles the conversion to the format of the monitor in use, and enables overlays that are only visible on the screen, both when recording and playing back a video.

A small add-on board monitors the ignition and triggers the controlled shutdown of the system as soon as the ignition is turned off.

Software

The measurement box runs the adapted software of the previous TPU version based on an embedded real-time operating system. On the main device a Linux system hosts the TPU main process, which performs the graphical user interface and the creation, storage and administration of the video files. Both the main process and the software of the measurement box are realized via a framework (developed by Reimesch Kommunikationssysteme and used in many products). The control software for the video codec is also executed in the main process.