As we all know, the operation of any machine will produce vibration, some vibration represents normal operation, and some vibration represents the initial signal of failure. In the field of predictive maintenance, detecting vibration characteristics is a key factor in the diagnosis process. Through vibration detection, problems can be identified and mitigated to avoid more serious events. By sensing, amplifying and measuring subtle movements, American Philips enables users to see the vibration characteristics on factory assets (such as machines) to ensure the normal operation of machines.
Traditional detection is time-consuming and costly
The traditional method of detecting machine vibration is to deploy wired sensors (such as contact accelerometers) on the machine to monitor the vibration. After obtaining the data from the sensor, the working vibration mode of the data is analyzed to present the animation model of the machine motion, so as to visualize the vibration mode.
However, according to Dr. Jeff hay, founder and CEO of RDI technologies (Knoxville, Tennessee, USA), this technology not only needs to take time to collect measurement data from multiple points, but also needs to be able to contact the machine. When the machine is inaccessible or not accessible at all (there are many obstacles or glass in front of the machine), the technology is often not possible to use. In addition, the traditional contact measurement often needs the machine to stop running when installing the accelerator, resulting in high costs due to downtime.
To this end, RDI technologies engineers have developed a revolutionary non-contact video processing system called iris m, which uses FLIR machine vision camera to sense, amplify and measure the subtle vibration caused by the machine, eliminating the inherent defects of early technology.
The iris M system uses the FLIR 2.3mpixel grasshopper3 camera installed on the vanguard tripod, which acquires monochrome image data with a default resolution of 1920×1050 and a speed of 120 frames / second.
The data obtained from the camera will be transferred to the tablet computer through the USB 3.0 interface. Here, the company’s special software is used for analysis, so that users can see the vibration characteristics on factory assets (such as machines).
Reasons for choosing FLIR machine vision camera
In iris M system, FLIR machine vision camera is equivalent to a data acquisition device. It collects video images, and then extracts and analyzes motion from them. The FLIR 2.3mpixel grasshopper3 gs3-u3-23s6m-c camera is mounted on a vanguard tripod and obtains monochrome image data with a default resolution of 1920×1050 and a speed of 120 frames / second. The acquired data will be transferred from the camera to the tablet computer of Getac F110 or Microsoft Surface book through the anti falling cable through the USB 3.0 interface.
The iris M system can directly measure the absolute displacement of plant assets that can be used to quantify movement from the image point, rather than interpreting the point measurement to determine the type of movement and the errors presented.
“Then the special video processing algorithm of computer software motion amplification will visualize the vibration of the machine. It will analyze the pixels of each image frame by frame to determine which parts of the scene are moving. Next, it will enlarge the amplitude changes of all motion amplitudes in the scene to the extent visible to the naked eye, so as to enhance the understanding between the components causing any vibration,” Dr. hay said.
By using the graphical user interface running on the computer, the user can select a part of the image for the next analysis. The system software will display the intensity data associated with these areas or related to time. Then, various mathematical functions (such as fast Fourier transform, also known as FFT) can be used to convert the time-dependent intensity data set into frequency dependent intensity data. The user will then be presented with absolute unaccepted amplitudes and vibration phases at different frequencies of the selected portion of the scene.
Iris M system is highly sensitive and can be used in more industries
Since its release in Q3 2016, iris M system has changed the way people in the industry use machines to monitor and observe vibration. The system is not only easy to use, but also can feed back visible and simple video images to users, so that users can better understand the operation status of the equipment.
According to Dr. hay, the choice of FLIR grasshopper camera has become a key reason for the success of the system. The camera has a 12 bit dynamic range, which can capture the subtle difference in pixel intensity between bright light and dark areas in the image, so that the system software can extract more detailed changes compared with other software.
The grasshopper camera series combines the latest CCD and CMOS technologies with point Grey’s expertise to achieve high-performance, high-quality imaging.
But equally important is the motif amplification algorithm itself. “Thanks to this unique algorithm, iris is about 100 times more sensitive than traditional image-based measurement tools in measuring displacement. In addition, iris M can directly measure from image points when necessary, which can be used to quantify the absolute displacement of motion without having to explain the point measurement to determine the type of motion and the errors presented,” he said.
Another advantage of this technology is the speed of data feedback and the level of detail of the data. Unlike the traditional contact measurement system, it can also be extended because it can simultaneously measure the vibration of all assets in the field of view of the camera. In addition, it makes itself a good communication tool between technical and non-technical users, because the root cause of any problem of any asset can be directly seen in the video.
The new system has been deployed in various practical applications. In addition to monitoring the status of industrial assets (such as machines), iris M system can also be used to analyze the structural integrity of bridges, buildings and similar structures. In addition, it can also be used in biomedical monitoring applications to evaluate individual respiration.