Production machines and machine tools are among the many automation technology applications that require controlled servo drives. Other applications include handling, printing, converting, and robots. Depending on the application's need for precision and whether it will employ position control, velocity control, or both, the system will choose a rotary encoders or encoder technology.
Precision in PositioningÂ
Accurate positioning is entirely dependent on the needs of the application. For instance, resolvers typically have one signal period for each rotation. Because of this, position resolution is very low and accuracy is usually within ±500 arcsec. Under the assumption that the drive electronics interpolate, this typically yields a total of 16,384 points each revolution.Â
- An inductive scanning mechanism, which is present in a lot of rotary encoders, will yield a much greater accuracy range of ±280 arcsec and a much better resolution, usually in the range of 32 signal periods per revolution. In this instance, the encoder's internal interpolation yields 131,072 places for each revolution.
- Since the foundation of optical rotary encoders is built on extremely small graduations—typically with 2048 signal periods per revolution—internal interpolation electronics can provide even greater resolutions. With an accuracy range of ±20 arcsec, the output resolution of 25 bits corresponds to 33,554,432 absolute positions every revolution.Â
Bandwidth
The natural frequency of the coupling and the stiffness of the coupling between the motor shaft and encoder shaft can both have an impact on bandwidth (about command response and control reliability). Encoders are capable of functioning within a designated range of acceleration. Typically, values fall between 55 and 2,000 Hz. On the other hand, long-lasting resonance vibration from an application or shoddy attachment may reduce performance and may even harm the encoder.
- The stator coupling design determines the natural frequencies. For best results, this frequency must be as high as feasible.
- Making sure that the encoder and motor bearings are as nearly perfectly aligned as possible is crucial. An example of how this is done is shown in Figure 4. The encoder's and the motor shaft's matching tapers provide almost exact alignment with the centerline.
Velocity Stability
An encoder is the first piece of the puzzle that needs to deliver a large number of measuring steps every rotation to guarantee smooth drive performance. Engineers must, however, also be mindful of the encoder signals' quality.Â
- It is necessary to interpolate the scanning signals to obtain the necessary high resolution. Signals that deviate from the desired shape can be caused by inadequate signal conditioning, contaminated measuring standards, and inadequate scanning.Â
- Errors whose periodic cycle falls inside one signal period can happen during interpolation. Thus, "interpolation errors" is another term for these position errors that occur inside a single signal period. These inaccuracies are usually 1 to 2 percent of the signal period with high-quality encoders.
After knowing the significance and application of any electronic components one would get a clear idea about what to select for their respective enterprise. If you still have any doubts regarding the features, application, benefits, maintenance, or troubleshooting aspects related to the rotary encoder and Hall Effect Sensor it is better to get some assistance. Seeking help at the right time from the right technicians would help individuals avoid unwanted breakdowns or failure.
Final Thoughts
A variety of considerations come into play when choosing a rotary encoder for controlled servo drives. Even if the criteria for positioning precision are crucial, it's important to understand how other aspects of the application, including speed stability, noise, potential power loss, and bandwidth, will be affected. Positive motor/drive system performance is ultimately achieved by a well-fitting motor/drive system from the outset.