Скачать или смотреть Real-Time Embedded Vision System for Autonomous Mobile Robots - Distance calculation

We developed an embedded vision system for autonomous mobile robots that can measure, in real-time, the distance from a specific obstacle. The vision system uses a single front camera as sources of information on the surrounding environment. The robot is able to calculate the distance of an obstacle that we have defined in advance and avoid it. In the proposed solution, we use color filter to detect obstacles and geometric optics equations to determine the distance to a defined object. To solve these equations, the square root calculation is required. However, the square root calculation is not easy to be implemented on FPGA. We have thus used a linear approximation with the basic arithmetic operators to perform the square root operation. To ensure real-time behavior, the whole system was implemented only in VHDL a parallel programming language on a Nexys 4 DDR development board with Artix FPGA device from Xilinx that operates at 100 MHz.