What factors affect the accuracy of the encoder?

When the number of lines and the unit of measurement of the encoder are determined, the accuracy is affected by the width and spacing of the lines or units of measurement. Inconsistent widths or spacing can cause errors in the pulses. At the same time, some external factors also affect the accuracy of the encoder. The accuracy of a rotary encoder depends mainly on the following aspects:

First, the direction deviation of the radial grating

Second, the eccentricity of the line code disc relative to the bearing

Third, the bearing radial deviation

Fourth, the error caused by the connection with the coupling

For linear encoders, temperature-induced reticle and expansion of the mounting surface also affect the accuracy of the encoder. Consistent width and measurement gap are key factors affecting the accuracy of the incremental encoder.

For servo motor encoders, the relationship between resolution and accuracy is very confusing. Accuracy depends mainly on the manufacturing process of the encoder, and the resolution can be improved by subdivision, but it does not mean that high resolution means that the encoder can achieve high precision. For example, by using the sin/cos incremental signal, the Siemens servo motor encoder can increase the resolution up to 24 bits (resolution 16777216), and the minimum unit that the encoder can describe after conversion is 0.07 arc seconds, but its physical accuracy is only It can reach ±40 arc seconds, and the resolution can provide much higher accuracy than the actual physical accuracy of the encoder.