Abstract: A detection circuit for instantaneous voltage drop and an on-board diagnostic system. The detection circuit comprises two RC circuits, each of the RC circuits comprises a first resistor, a second resistor, and an energy storage capacitor; a first end of the first resistor is used for receiving a to-be-detected voltage, and a second end thereof is connected to a first end of the second resistor; the energy storage capacitor is connected in parallel with the second resistor; the first end of the second resistor forms an output end of the RC circuit, and the output end is connected to an input end of the comparator; an output end of the comparator is connected to the determination unit; in the two RC circuits, the resistance ratios of the second resistors to the first resistors are different, the capacitances of the energy storage capacitors are different.

Abstract: A platform gauge instrument and a platform gauge measuring method based on a photogrammetric principle are provided. According to the platform gauge instrument, measuring stations are arranged on both sides of a platform, and the measuring stations on both sides work together to ensure the acquisition of complete platform information. The measuring stations have automatic traveling capability to complete scanning of a whole platform, platform information obtained by the scanning is automatically resolved by a measuring system, and gauge dimensions such as a transverse dimension and a vertical dimension of a platform gauge are resolved through parameters such as object-space coordinates of platform edge points, a space equation of intersection lines of upper surfaces of rails and a measuring cross-section, and common tangent lines of the upper surfaces of two rails on the measuring cross-section, so that resident and real-time gauge high-precision detection of the platform is achieved.

Abstract: A platform gauge instrument and a platform gauge measuring method based on a photogrammetric principle are provided. According to the platform gauge instrument, measuring stations are arranged on both sides of a platform, and the measuring stations on both sides work together to ensure the acquisition of complete platform information. The measuring stations have automatic traveling capability to complete scanning of a whole platform, platform information obtained by the scanning is automatically resolved by a measuring system, and gauge dimensions such as a transverse dimension and a vertical dimension of a platform gauge are resolved through parameters such as object-space coordinates of platform edge points, a space equation of intersection lines of upper surfaces of rails and a measuring cross-section, and common tangent lines of the upper surfaces of two rails on the measuring cross-section, so that resident and real-time gauge high-precision detection of the platform is achieved.