## 1 Introduction
### Overview of High-Speed Camera Applications
The generalised Reynolds equation was derived, taking into account the cavitation mechanism based on the modified Elrod method, and the cavitation of sleeve bearings with different viscosity parameters was analysed and compared. There was a great deal of similarity between the experimental results (measured using a high-speed camera) and the theoretical results. [PERSON] and [PERSON] [20] used a high-speed camera to analyse transverse bearings operating under different dynamic loads. The study aimed at determining when and where cavitation occurred in the bearings. It affected both the energy loss and operating stability of the bearing. A high-speed camera was used to test cavitation in dynamically loaded radial bearings. The ratio of the length of the bearing to its diameter, the rotational speed, the material with which the shaft was coated as well as the static and dynamic eccentricity of the bearing were changed. The results obtained indicate not only the occurrence of gas cavitation but also the development of steam cavitation (which was not expected). [PERSON] et al. [21] presented research on three-camera videogrammetry for three-dimensional measurement of laminated rubber bearings based on a shaking table. Laminated rubber bearings are widely used to mitigate seismic damage to large structures and equipment. In this work, a three-dimensional measurement of the displacement of a laminated rubber bearing based on a large-sized shaking table was performed. Authors used three high-speed CMOS cameras, one synchronous controller, and one pair of 1000 watt light sources, which were used to simultaneously acquire three-camera sequences of a laminated rubber bearing image at 300 frames per second (fps). This article proposes a fast image blocking technique to detect and track objects in three-dimensional image sequences by integrating methods for morphological edge detection, attribute-based ellipse extraction, and least-squares based matching adjustment. [PERSON] et al. [22] presented Single-camera single-axis vision method applied to measure vibrations. The authors wrote that 3D vision methods used with two high-speed cameras turned out to be a valid solution to measure 3D displacements, particularly with the stereo digital image correlation (SDIC) tool. The conventional pseudo-stereo system with a single high-speed camera and a four-mirror adapter, generating two virtual cameras, may also be used, even if it is rather difficult to operate and is limited to small objects. [PERSON] et al. [23] presented tests of speed estimation using a visual method. Diagnosis of engine bearing faults at variable speed can sometimes be a problem. This paper proposes a new, computer vision-based order tracking method to address this problem. First, video footage recorded by a high-speed camera is analysed using an accelerated, robust algorithm used to extract and match functions to obtain the instantaneous motor speed (IRS). Then, an audio signal picked up by a microphone was polytonally sampled to follow the IRS curve, so that the signal could be represented in the angular domain instead of the frequency domain. The envelope sequence spectrum was then calculated to determine the damage pattern. The effectiveness and strength of the proposed method were verified using two brushless test stands for D.C. motors, where two damaged bearings and a healthy bearing were tested separately. This test used a new, non-invasive approach to measurement, which made it possible to avoid the installation of a tachometer and overcome the drawbacks of methods of tracking the order of motor bearing damage at variable speed. [PERSON] et al. [24] presented experimental and numerical research carried out on a car turbocharger with a transparent bearing section. The dynamic performance of the car turbocharger supported by bearings with a full floating ring was tested experimentally and numerically. The movement orbit of the rotor was mounted on the compressor side and, after modifying the turbocharger's housing, the speed of the floating ring were tested.