What are the interference solutions for high-speed servo motor encoders

What are the interference solutions for high-speed servo motor encoders?

High-speed servo motor encoders have applications in many fields, among which as the core component of some automation equipment is the general application of high-speed servo motor encoders. The reliability and stability of high-speed motor encoders directly affect the performance of the equipment. One of the main factors affecting its reliability and stability is anti-interference. The editor of okplazas.com encoder will give you an analysis: high-speed servo motor encoder What are the solutions to interference?

In addition to the ABZ signal of the ordinary encoder, the incremental encoder of the servo motor also has the UVW signal. Most servos in the world adopt this form. The servo motor incremental encoder outputs pulses when it rotates, and knows its position through the counting device. When the encoder does not move or the power fails, it relies on the internal memory of the counting device to remember the position. In this way, after a power failure, the encoder cannot have any movement. When the power is applied, the encoder cannot lose pulse due to interference during the output pulse. Otherwise, the zero point memorized by the counting device will shift, and the amount of this shift is impossible to know, only after the wrong production result appears. The solution is to increase the reference point. Every time the encoder passes the reference point, the reference position is corrected into the memory position of the counting device. Before the reference point, the accuracy of the position cannot be guaranteed. For this reason, in industrial control, there are methods such as first finding the reference point for each operation, turning on the machine, and so on.

What are the interference solutions for high-speed servo motor encoders? Analysis of the interference source of the servo motor encoder;

There are two main types of interference source analysis for servo motor encoders:

One is the signal transmission channel interference; the interference enters through the signal input channel and output channel connected to the system. The second is the interference of the power supply system. The signal transmission channel is the way for the control system or driver to receive the feedback signal and send out the control signal, because the pulse wave will appear delay, distortion, attenuation and channel interference on the transmission line. In the transmission process, the long-term interference is the main factor.

There are internal resistances in any power supply and transmission lines. It is these internal resistances that cause the noise interference of the power supply. If there is no internal resistance, no matter what kind of noise will be absorbed by the power supply short-circuit, no interference voltage will be established in the line. , AC servo system driver itself is also a strong source of interference, it can interfere with other equipment through the power supply.

What are the interference solutions for high-speed servo motor encoders? Anti-jamming countermeasures of servo motor encoder;

Anti-interference design of power supply system

(1) Perform power subcontracting power supply, such as separating the drive power supply and control power supply of the motor to prevent interference between devices.

(2) Even if the noise filter is used, it can effectively suppress the interference of the AC servo drive to other equipment. This countermeasure can effectively suppress these noise phenomena.

(3)Using an insulating transformer, high-frequency noise through the transformer is mainly not the mutual inductance coupling of the primary winding, but the primary parasitic capacitive coupling, so the shielding layer is used to insulate the primary stage of the insulating transformer to reduce its distributed capacitance and prevent common mode interference. ability.

What are the interference solutions for high-speed servo motor encoders? Anti-interference design of signal transmission line;

(1) Photoelectric coupling separation method

In long-distance transmission, a photocoupler can be used to cut the connection between the control system and the input channel, output channel, and input and output channels of the servo drive. If the circuit does not use photoelectric separation, external spike noise signals will enter the system, or directly enter the servo drive device, and the first noise phenomenon will occur.

(2) Twisted-pair shielded wire long wire transmission

The signal is affected by interference factors such as electric field, magnetic field, ground impedance, etc. during transmission, and the interference of electric field can be reduced by using a grounded shield wire. Compared with the coaxial cable, the twisted pair cable has a poor frequency band, but has high wave impedance and is resistant to common mode noise, which can cancel the electromagnetic induction noise of each small link. In addition, long-distance transmission generally uses dynamic signal transmission to improve anti-interference performance. Long-line transmission using twisted-pair cables can effectively suppress several interference phenomena.

What are the interference solutions for high-speed servo motor encoders? As mentioned above, there are two main noise sources for high-speed motor encoders, and there are two types of noise countermeasures, including the noise countermeasure design of the power supply system and the noise countermeasure design of the signal transmission path.