An analysis of additional errors of the optical-electronic system for monitoring the railway track position

Subject of research. The paper considers an additional error in the railway track position control by stereoscopic methods and examines how the components of the error influence on the measurement results of linear displacements of the track in the profile and plan. Method. The authors propose to use active reference marks located on the supports of the contact network and describe a method for assessing additional errors of the track position control made by a stereoscopic optical-electronic system. On the basis of computer modeling, we investigate the degree of influence of the components of the system error on the total value of the additional error. The conclusions are formulated through analysis of the diagrams obtained via a computer model and the results of an experimental study of the system's technological samples. Main results. The work reports on the relationship between the linear displacements of the track in the profile and plan with the coordinates of the reference marks as well as the parameters of the system elements with the informative parameters of the signal. A mathematical description of the components of additional errors of the stereoscopic system with changes in the medium temperature, vibration amplitude, vertical gradient of the air path temperature, and movement speed is proposed. It is shown that the components of the error caused by vibrations, inertia of the system, and thermal deformation of the base unit produce the greatest effect on the total additional error in decreasing order. Theoretical, experimental and field testing have shown that the assessment of the random component of the displacement control error when measuring the track position does not exceed 0.8 mm in the longitudinal profile, and 1.8 mm in the plan. Practical relevance. The authors developed a method for studying additional errors in determining the displacement of the track in the profile and in the plan by means of a stereoscopic control system. The prepared recommendations can reduce the most strongly influencing components of the additional error. A stand and software for static and dynamic testing of physical models have been created. The proposed solutions are aimed at achieving full automation of control of the actual position of the railway track when servicing continuous straightening technologies with high-performance track machines using stereoscopic optical-electronic systems. The results can be applied by developers of high-precision optical-electronic systems for ensuring the safety of railway traffic.