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The subject of the study is the process of applying optical technologies for non-contact measurements of geometric parameters of a wagon wheelset during operation and repair. The purpose of the study is to study the methods of field testing of technologies for controlling the geometric parameters of car parts using an optical rangefinder, with mutual verification of the results obtained using numerical modeling using three-dimensional digital models of objects and measuring instruments. As a result of the study, experimental and calculated dependences of the optical sensor readings were obtained during the change in the relative position of the measuring object (wheelset) and the rangefinder. Two laser triangulation rangefinders were used for field tests. For numerical simulation, a program was created that allows generating a three-dimensional model of the rolling surface of a wheelset consisting of a set of points belonging to the surface of rotation. The simulation consists in finding the intersection points of a line defined using the coordinates of the point of the radiation source in space and the guiding vector with the model of the skating surface. After the calculations, the result is given in the form of a table with calculated ranges and visualized as projections of a three-dimensional wire model of a wheel and a rangefinder beam. Visualization of the numerical modeling process is important to avoid misinterpretation of the calculation results and to verify compliance with the physical meaning of the numerical data obtained during modeling. Comparison of graphs shows the convergence of the results and sufficient accuracy of numerical models and techniques that can be used in the future to plan full-scale tests of the designed techniques and equipment for dimensional control of railway car parts.

A variant of application of a contact compensated chain suspension with levers and lateral current collection for a three-phase traction power supply system (TSTE) is considered. Two different-phase contact suspensions are located on different sides of the track axis. The electric rolling stock must have two current collectors that press on the contact wire from the track axis in opposite directions. The description of the design of the contact suspension as a whole and the main components, in particular, the fastening of the rods, which makes it possible to provide a vertical zigzag and limit the transverse movement of the contact wire, is made. At points at the supports, the levers are connected to the consoles and have a knot to create angular rigidity. In addition, the rotation of these levers is limited towards the axis of the path and in the opposite direction. This prevents the possibility of lashing of different-phase contact wires. In accordance with this design, a mathematical model of this contact suspension was developed based on the finite element method, which provides calculation in statics and dynamics, taking into account the current collector. To describe the pantograph, a common three-mass model is used. Based on the analysis of the results obtained using this model, the influence of the design parameters of the suspension, cross wind and the speed of the pantograph movement on the quality of the current collection is determined, the limits of applicability of the suspension under consideration, depending on the value of these parameters, are established. It has been determined that, in contrast to a conventional contact suspension with a vertical current collection, for suspensions with a lateral current collection, a side wind has a significant effect on the quality of the current collection. It is the wind speed that is the main factor limiting the possibility of using a suspension with lateral current collection.