Which Encoder Can Measure Speed?

Encoder is a device that compiles and converts signals or data into signals that can be used for communication, transmission and storage. The encoder converts angular displacement or linear displacement into electrical signals. According to the readout mode, the encoder can be divided into contact type encoder and non-contact type encoder. According to the working principle, encoders can be divided into incremental encoder and absolute encoder. The incremental encoder converts the displacement into a periodic electrical signal, and then converts the electrical signal into a counting pulse. The number of pulses is used to represent the displacement. Each position of the absolute encoder corresponds to a certain digital code, so its indication is only related to the starting and ending positions of the measurement, and has nothing to do with the intermediate process of the measurement.

The fanuc encoder and resolver can be used to track the angle and linear position of objects, such as motor shaft, linear actuator, etc. If a clock signal is added to the encoder, the pulse coder can be used to measure the speed of the object.

The resolver consists of a rotor with a primary winding and a stator with two secondary windings separated by 90 degrees. When voltage is applied to the primary rotor winding, voltage is generated in the stator winding. These voltages are equal to the reference voltage multiplied by the sine or cosine of the angle between the axis and zero. The speed of the resolver and its connected axis can be determined by obtaining the rate of change of the secondary signal, i.e. sine signal or cosine signal.

Encoder Speed Based On Pulse Frequency

In order to determine the speed of the fanuc spindle encoder according to the pulse frequency, we need to know some parameters, including the number of pulses calculated in each time sample, pulses per revolution and time sampling period. 

This method can provide the average speed of multiple pulses, but this method cannot be used to calculate very slow speeds. When the speed is very slow, there may be few or no pulses in the measurement time, so it is impossible to calculate.

Encoder Speed Based On Pulse Period

In addition to determining the speed of the fanuc servo motor encoder according to the pulse frequency, we can also use the pulse period to determine the speed of the fanuc original encoder. The duration of each pulse is timed using a high-frequency constant signal, which is usually the time from the rising edge of one pulse to the rising edge of the next pulse. The duration of a pulse can be obtained by dividing the number of cycles of the clock signal by the clock frequency.

Using the pulse period method to determine the speed of the fanuc professional encoder is more accurate than using the pulse frequency method. However, at high speed, the pulse frequency will become very high and the time between pulses will become very short. At this time, the counter may not be able to accurately measure the speed of the fanuc industrial encoder.