The integrated system has been implemented at DRA Chertsey to run live on the ROVA (ROad Vehicle Autonomous, the ALV at DRA Chertsey) PowerPC-based image processing system (see Figure 11).
Figure 11: The real-time implementation of the integrated
ASSET-DROID-ALTRUISM system on the ROVA PowerPC-based image processing
system.
Feature detection is performed by custom hardware supplied by Roke Manor Research Limited, which provides a list of 2D features at full frame rate (25 Hz), using the Harris corner finding algorithm. (Digitization and display are performed using a Datacube Digimax/Framestore VME board pair.) The feature list is sent down a Transputer link to the first of four Parsytec Transputer/PowerPC processing boards, straight into PowerPC memory.
The feature tracking stage of ASSET-2 runs on the first PowerPC board at full frame rate. The resulting vector flow field is sent down a Transputer link to the second PowerPC board, where the remainder of ASSET-2 is run, also at full frame rate. Results can be graphically overlaid onto the original images for real-time display.
The 2D features corresponding to the background in the image sequence are then sent to the third PowerPC board, where DROID runs at full frame rate. DROID then sends the list of 3D points and the 3D camera position to ALTRUISM, which runs on the fourth PowerPC board, also at full frame rate. Again, results can be graphically overlaid onto the original images from this board.