Process and a system for measuring and recording undulatory deformations of a rail surface
First Claim
1. A process for measuring and recording undulatory deformations of a rail surface, comprising the steps of moving a feeling device along said rail surface, a vertical acceleration of said feeling device being produced upon moving along said rail surface and encountering undulations, generating a voltage signal by means of an accelerometer connected to the feeling device, said voltage signal being representative of the vertical acceleration of the feeling device moved along the rail surface, amplifying the voltage signal and filtering the thus amplified voltage signal through a filter, the filter having a central frequency and band width which vary as a function of the velocity of travel of the feeling device along the rail such that the response characteristics of the filter to wavelengths of the undulations of the rail falling with a range desired to be measured are substantially independent of the velocity, twice integrating the filtered signal, rectifying the twice integrated signal and amplitude-modulating the rectified signal through a circuit, the circuit having a response characteristic directly proportional to the velocity of travel of the feeling device along the rail, filtering the modulated signal to eliminate spurious signals having extremely high amplitude and frequency filtering signal, and recording the lastly filtered signal on a recorder.
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Abstract
A process and a system for measuring and recording undulatory deformations of a rail surface. A feeling device is moved along the rail surface and an accelerometer is connected to the feeling device to generate a voltage signal representative of the acceleration encountered by the feeling device in contact with the deformations. The signal is amplified and filtered in function of the speed of the vehicle carrying the system, and thereafter twice integrated, then rectified and amplitude-modulated in function of the vehicle speed. A filter eliminates spurious signals from the modulated signal and a recording of the lastly filtered signal is effected. In addition, there is also provided a circuit for measuring and recording sound signals generated by the rolling vehicle.
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Citations
17 Claims
- 1. A process for measuring and recording undulatory deformations of a rail surface, comprising the steps of moving a feeling device along said rail surface, a vertical acceleration of said feeling device being produced upon moving along said rail surface and encountering undulations, generating a voltage signal by means of an accelerometer connected to the feeling device, said voltage signal being representative of the vertical acceleration of the feeling device moved along the rail surface, amplifying the voltage signal and filtering the thus amplified voltage signal through a filter, the filter having a central frequency and band width which vary as a function of the velocity of travel of the feeling device along the rail such that the response characteristics of the filter to wavelengths of the undulations of the rail falling with a range desired to be measured are substantially independent of the velocity, twice integrating the filtered signal, rectifying the twice integrated signal and amplitude-modulating the rectified signal through a circuit, the circuit having a response characteristic directly proportional to the velocity of travel of the feeling device along the rail, filtering the modulated signal to eliminate spurious signals having extremely high amplitude and frequency filtering signal, and recording the lastly filtered signal on a recorder.
- 10. A system for measuring and recording undulatory deformations along a rail surface, comprising means mountable on a rail-born vehicle for feeling said deformations along the surface, an accelerometer connected to said feeling means to generate a voltage signal representative to the vertical acceleration induced in the feeling means by said undulatory deformations, means connected to said accelerometer for amplifying the voltage signal, means including a filter connected to the amplifying means for filtering the amplified signal as a function of the velocity of the vehicle, said filter having a central frequency and band width which vary such that the response characteristics of the filter to wavelengths of the undulations of the rail falling within a range desired to be measured are substantially independent of the velocity, means connected to the filtering means for twice integrating the filtered signal, means connected to the integrating means for rectifying the integrated signal, means connected to the rectifying means for amplitude-modulating the rectified signal in direct proportion to the velocity of the vehicle, means connected to the amplitude-modulating means for filtering the modulated signal to eliminate spurious signals having extremely high amplitude and frequency with respect to said modulated signal and means connected to the amplitude-modulating means for recording the resulting signal.
Specification