Abstract: A method for identifying pitch error and yaw error of a numerically-controlled (NC) machine tool, including: acquiring a Cartesian coordinate system of a target machine tool; setting each axis of the Cartesian coordinate system as movement axis, where each movement axis has three measurement trajectories, and the three measurement trajectories are mutually parallel to the corresponding axis, and not on the same plane; selecting an axis as the movement axis; and obtaining positioning error data between an actual operation measurement point and an ideal operation measurement point of the target machine tool when the target machine tool moves along the three measurement trajectories corresponding to the movement axis; and according to spatial angle geometric relationship and the positioning error data, obtaining a pitch error angle and a yaw error angle of the target machine tool.

Abstract: A method for identifying pitch error and yaw error of a numerically-controlled (NC) machine tool, including: acquiring a Cartesian coordinate system of a target machine tool; setting each axis of the Cartesian coordinate system as movement axis, where each movement axis has three measurement trajectories, and the three measurement trajectories are mutually parallel to the corresponding axis, and not on the same plane; selecting an axis as the movement axis; and obtaining positioning error data between an actual operation measurement point and an ideal operation measurement point of the target machine tool when the target machine tool moves along the three measurement trajectories corresponding to the movement axis; and according to spatial angle geometric relationship and the positioning error data, obtaining a pitch error angle and a yaw error angle of the target machine tool.

Abstract: The present invention provides an indoor fresh air apparatus, comprising a body, an elementary filtering means, a deodorizing module, a blowing-in machine, a first haze removing module, a second haze removing module and a third haze removing module. The body is provided with an air-in passage serving as an air-in end and an air-out passage serving as an air-out end. The elementary filtering means is disposed at the air-in end; the deodorizing module is disposed within the air-in passage; and the blowing-in machine is disposed at the air-out end. The air-in passage, the first haze removing module, the second haze removing module, the third haze removing module and the air-out passage are connected in order. The air treatment unit provided by the present invention is capable of not only completely recovering cold energy or heat energy of indoor air, but also effectively treating indoor and outdoor PM2.5 and harmful gases.