High-speed, high-accuracy and high-redundancy absolute grating ruler reading head device

Abstract

The invention discloses a high-speed, high-accuracy and high-redundancy absolute grating ruler reading head device. The high-speed, high-accuracy and high-redundancy absolute grating ruler reading head device comprises a tackle body (1), grating glass (3), an absolute code channel (4), an incremental code channel (5), an absolute code channel collector (6), a first indication grating (7) and a second indication grating (8), wherein the grating glass (3) is installed below the tackle body (1), the absolute code channel (4) and the incremental code channel (5) are marked on the grating glass (3) side by side, the first indication grating (7) and the second indication grating (8) are installed in the movement direction of the tackle body (1) side by side and are located over the incremental code channel (5), and the absolute code channel collector (6) used for collecting information about whether the reading head reaches the absolute position or not is also installed on the tackle body (1) and located over the absolute code channel (4). Under the high-speed and high-accuracy working condition of a grating ruler, reading reliability is guaranteed, and the functions of displacement calculation and multiple limitation of the grating ruler are provided.

Description

technical field [0001] The invention is a high-speed, high-precision, high-redundancy absolute grating ruler reading head device, which belongs to the innovative technology of the high-speed, high-precision, high-redundancy absolute grating ruler reading head device. Background technique [0002] In the modern machining industry, grating sensors are mostly used as position feedback devices. Since the grating ruler can implement full closed-loop control on the system, reduce the error caused by the thermal deformation of the ball screw and improve the machining accuracy, so the grating ruler is more and more used as the linear displacement feedback element in the current high-end CNC system [1] . Its high precision and high resolution combined with a relatively low price make it widely used not only in the field of machine tools, but also in coordinate measuring machines, robotics, every position and speed measurement, and position and motion control applications [2] . [...

AI Technical Summary

Problems solved by technology

[0004] Since the incremental grating scale counts the moiré fringes and outputs pulse signals, it can reach a high speed during work, but its accuracy is generally not as good as that of the absolute grating scale, and cannot meet the processing requirements of higher precision; The absolute grating ruler uses the camera to capture the image of the absolute code track through a magnifying glass to decode the current absolute position. However, although this code reading method can achieve high accuracy, when the speed exceeds a certain threshold, it will produce drag. Therefore, the purpose of high-speed work cannot be achieved, resulting in low processing efficiency

[0005] In addition, the traditional grating ruler only relies on one code track to read the position information, which has low reliability, especially after being polluted, the bit error rate is extremely high; if the grating ruler fails, it cannot be used normally immediately; the limit function method is single, If the limit device fails, the grating scale is vulnerable to strong impact and scrapped

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