NEAR-FIELD ELECTROMAGNETIC INTERFERENCE MEASUREMENT USING COMPUTER VISION COLOR TRACKING ALGORITHM
Publication Date: 2017-Aug-09
The IP.com Prior Art Database
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Keysight Technologies, Inc.
Electromagnetic interference (EMI) measurements are becoming more challenging due to the increasing density of components in electronic systems. Each of the component may potentially be a source of EMI. Thus, it is essential to perform high resolution electromagnetic measurement mapping on all the electronic components to ensure compliance with the electromagnetic compatibility standards. Automated robotic near-field scanning system using a sniffer probe is a commonly used method for EMI measurements [1−4]. Typically, the sniffer probe scans a predefined map in space and takes spectrum measurements at each location and then generates the electromagnetic emission data. However, it is difficult to accurately reconstruct the radiation pattern in space without storing or otherwise tracking the location of the probe in the scanning process. Additionally, the robotic arm in a conventional robotic system may limit the measurement of flat/cylinder/sphere surfaces and/or hard-to-reach area of device under test (DUT) .
The present disclosure provides an alternative near-field scanning system with live visualization of electromagnetic measurement mapping in the form of spectrum heatmap overlaid on the image of DUT. During the scanning process, the images of DUT and probe are recorded using a camera. The spectrum heatmap is generated by a computer vision color tracking algorithm that tracks the movement of the probe over the DUT and displays the electromagnetic measurement acquired at each location. The scanning is performed manually, which enables the probe to move over flat/cylinder/sphere surfaces of a DUT. The color tracking algorithm also includes a maximum hold feature to record the highest EMI reading for each location. Therefore, the same location of a DUT can be revisited multiple times with different probe orientation to find the maximum EMI radiation.
FIG. 1 shows an example of the near-field scanning system setup 10 in accordance to the present disclosure. The system includes a controller 11, which is a computer equipped with the vision color tracking algorithm. The controller 11 is connected to an EMI test instrument such as a spectrum analyzer 12 equipped with a probe 13.The tip of the probe 13 has a color that is distinguishable from the background and DUT 15. For example, a red tip is selected for the probe for a non-red background and so on. The controller 11 is also connected to a camera 14, such as an internet protocol (IP) or universal serial bus (USB) camera. The camera 14 is integrated into the application software of the spectrum analyzer 12.
FIG. 2 shows an example of the EMI measurement process flow chart for the computer vision color tracking algorithm. In the initiation setup, the controller first...