USP Researchers Develop Support to Drive Down Costs of Optical Sensors
When it comes to cameras for inspection, monitoring and investigation of patterns or phenomena, high spatial resolution, a high number of pixels and a high temporal resolution are required, with a high acquisition frequency. However, this equipment can often be expensive or unavailable. That’s why doctoral students from the Department of Mechanical Engineering (PME) at the Polytechnic School (Poli) of USP developed the patent Support for optical alignment of cameras for multiframe image acquisition .
The technology aims to unite a set of simple cameras to perform the work of a single specialized camera. Thus allowing, for example, the equipment to investigate bubble flow in the production of hydrogen in an industrial reactor or smoke in a fire detection system in a commercial or residential environment.
“You have a camera with high temporal resolution and low partial resolution or vice versa. It’s like the short sheet metaphor, you’re cold and you want to cover your nose, but when you cover your nose, you leave your legs uncovered. So our invention, in a way, works to break this limit of simultaneous high temporal and partial resolution in image acquisition”, explains Rodrigo de Lima Amaral, postdoctoral fellow at Poli.
Portable sensors
Currently, an amateur digital camera has a high partial resolution, so the support allows the alignment of up to four devices to jointly produce an image that provides high spatial and temporal resolution. “The support uses a set of mirrors that allow the cameras to be aligned and record the same field of view, these cameras are synchronized and the images are interleaved so that together they produce what we call time-resolved images”, adds Amaral.
The researchers pointed to the technological advancement of portable cameras as inspiration for the patent. “It may be possible to use lower-cost cameras like a cell phone camera to carry out this type of measurement, but then you have the difficulty of temporal resolution of not having such a fast frames per second acquisition frequency for these cameras. So, in that sense, we came up with the idea of support”, reports Vítor Augusto Andreghetto Bortolin, a doctoral candidate at Poli.
The support is compact in size and can be manufactured using a 3D printer, enabling on-demand production. It may include black piers, which are light splitters reflecting the image to one camera and allowing the same image to pass to another camera; or even chrome mirrors, which reflect a specific color to one camera while allowing other colors to pass through to another camera.
The technology is still in the development stage and the researchers highlight the importance of partners who can provide the optical instruments necessary for patenting and printing the supports on a large scale. Bernardo Luiz Harry Diniz Lemo, PhD at Poli, says that “we consider it possible to correct certain flaws in the images, for example, certain misalignments, however small they may be, which is why we are developing other patents and other software to correct these problems afterwards ”