Abstract: A feature map generation method/apparatus including obtaining a plurality of image frames photographed for a target scene, separately extracting image feature points from each image frame, determining corresponding feature descriptors, forming image feature points with a matching relationship in the image feature points of the each image frame into a feature point set, determining a representative feature point from the feature point set, calculating a difference between a feature descriptor corresponding to a remaining image feature point and a feature descriptor corresponding to the representative feature point, determining a position error of the feature point set, iteratively updating the remaining image feature point in the feature point set, and obtaining an updated feature point set, and determining a space feature point corresponding to the updated feature point set, and generating a feature map based on the space feature point.

Abstract: The present invention discloses an online method for metering performance of a diaphragm gas meter. A magnetic turntable in an electromechanical conversion device is reasonably segment and motion information of each segment is recorded and analyzed. Every time when the diaphragm gas meter discharges gas of a rotary volume, a rotating shaft of a meter core rotates a circle. The magnetic turntable is meshed with a driving gear output by the rotating shaft in the meter or output by the rotating shaft outside the meter to ensure that the magnetic turntable rotates a circle every time when the diaphragm gas meter discharges a rotary volume. The present invention is significant for error management of the gas meter and intelligent control and gas utilization safety management of a gas user.

Abstract: The present invention discloses a method for gas safety management by registering gas equipment information in a gas meter. The specific working step includes the following steps: a1: determining whether one startup is an illegal startup; a2: making safety judgment in flow increase; a3: determining that a flow rate should be lower than a sum of maximum flow rates and should not be higher than a range flow rate; and a4: Startup characteristic judgment is made for a startup process and superposition judgment is made for flow increase, in order to prevent accidents caused by leakage in the startup process and the using process.

Abstract: The present invention discloses an online method for metering performance of a diaphragm gas meter. A magnetic turntable in an electromechanical conversion device is reasonably segment and motion information of each segment is recorded and analyzed. Every time when the diaphragm gas meter discharges gas of a rotary volume, a rotating shaft of a meter core rotates a circle. The magnetic turntable is meshed with a driving gear output by the rotating shaft in the meter or output by the rotating shaft outside the meter to ensure that the magnetic turntable rotates a circle every time when the diaphragm gas meter discharges a rotary volume. The present invention is significant for error management of the gas meter and intelligent control and gas utilization safety management of a gas user.

Abstract: Apparatus and methods for detecting wave front aberration of a projection objective lens in a photolithography machine are disclosed. The apparatus comprises: a light source system configured to generate an illuminating beam; a spatial filter configured to receive the illuminating beam and generate ideal spherical wave; a splitter plate arranged downstream to the spatial filter at a predetermined angle with respect to an optical axis of the spherical wave and having a transflective film being applied on a surface thereof; the projection objective lens configured to receive a beam from the splitter plate and generate an output beam; a spherical mirror configured to reflect the output beam from the projection objective lens to the projection objective lens, light passing through the projection objective lens being reflected by the splitter plate; and an interferometer configured to receive light reflected by the splitter plate and measure the wave front aberration of the projection objective lens.

Abstract: Apparatus and methods for detecting wave front aberration of a projection objective lens in a photolithography machine are disclosed. The apparatus comprises: a light source system configured to generate an illuminating beam; a spatial filter configured to receive the illuminating beam and generate ideal spherical wave; a splitter plate arranged downstream to the spatial filter at a predetermined angle with respect to an optical axis of the spherical wave and having a transflective film being applied on a surface thereof; the projection objective lens configured to receive a beam from the splitter plate and generate an output beam; a spherical mirror configured to reflect the output beam from the projection objective lens to the projection objective lens, light passing through the projection objective lens being reflected by the splitter plate; and an interferometer configured to receive light reflected by the splitter plate and measure the wave front aberration of the projection objective lens.