How the encoder affects production efficiency

For production equipment, the cost of the encoder is almost insignificant. The cheap encoders on the market are hundreds, thousands even tens of thousands yuan, which looks dozens of times better, but only 10,000 yuan. No matter how large the quantity is, compared with the cost of the equipment production line, the price difference is just a drop in price.

So in this seemingly trivial part, choosing different types of encoders will affect equipment performance production efficiency. This is our topic today.

What we are talking about today applies only to the encoder used alone, but also to the encoder feedback of the servo motor.

Incremental vs absolute

The encoder of the incremental encoder is accumulated by pulses in motion, the position cannot be memorized after the power is off. After powering on again, the encoder value will always be recorded zero.

Therefore, for devices that use incremental encoders, the encoder needs to be initialized back to the origin after the device is powered on. Usually this action is to manually operate the encoder station slowly find the reference position (such as limit). This is technically called "homing", "searching", "returning to zero". . .

It is conceivable that such an operation will affect the startup time of the device, it takes several minutes to start normal production every time it is turned on. For example, if the production capacity of the equipment is 1,000 yuan/minute, it takes 5 minutes to return to the origin every time it is turned on. The equipment is turned on 20 times a year (including maintenance failure). Then perform 10 equipment initialization operations per year. Spent ten thousand yuan.

Isn't this scary?

Therefore, the reciprocating motion position measurement feedback in the limited stroke range is usually as far as possible to use incremental encoders, but to use absolute position feedback. The position code of the absolute encoder is obtained directly according to the position through the internal circuit of the encoder does rely on external power supply. Therefore, the position value can still be measured read after the power is off, but because the system is powered off, the code cannot be fed back to the equipment system.

So, is it possible to save the initialization of the device back to the origin by using an absolute encoder?

This depends on the number of turns of the absolute encoder. If the number of turns of the absolute encoder used cannot cover the range of motion, the above initialization action cannot be omitted. In many cases, there is much difference between using a single-turn absolute encoder an incremental encoder.