A reconfigurable hardware application for machining of metal parts

Image processing algorithms can be used to mitigate and detect anomalies or to monitor a process such as machining of metal parts. For certain applications, typically involving high-precision components, it is desirable to detect the variability in material properties such as grain size or hardness of the workpiece material. The hardness of a finished part is determined using a high speed video camera (4000 frames/sec) and an image processing algorithm. The algorithm has a feed-forward data flow that consists of three stages: edge detection of the frame, interframe differencing to eliminate any static particles, and a cross-correlation routine to determine the chip velocity. This velocity yields information pertaining to the hardness of the metal, i.e. slower velocities correspond to softer materials, etc. Processing in real-time is necessary because of the high frame rate of the camera. Thus, a specialized hardware system is investigated. The target hardware is a specialized reduced instruction set computer (RISC) processor, the Stretch S5000, that contains a hardware accelerator built into the processor called the Instruction Set Extension Fabric (ISEF). Performance is reported in terms of algorithm run-time speed, power usage, memory implementation issues and ease of development.