Italian ELTRA rotary encoder

The working principle and application of Italian ELTRA rotary encoder The working principle and function of Italian ELTRA encoder: It is a rotary sensor that converts the rotation displacement into a series of digital pulse signals. These pulses can be used to control the angular displacement. It can also be used to measure linear displacement in combination with gears or spiral screws.

　　Italy Iltron encoder generates electrical signals and is processed by digital control CNC, programmable logic controller PLC, control system, etc. These sensors are mainly used in the following areas: machine tools, material processing, motor feedback systems, and measurement and control equipment. The conversion of angular displacement in the ELTRA encoder uses the photoelectric scanning principle. The reading system is based on the rotation of a radial index plate, which is composed of alternating light-transmitting windows and opaque windows. This system all uses an infrared light source to illuminate vertically, so that the light projects the image on the plate onto the surface of the receiver, which is covered with a layer of grating, called a collimator, which has the same window as the optical disc. The job of the receiver is to feel the light changes produced by the rotation of the disc, and then convert the light changes into corresponding electrical changes. Generally, a rotary encoder can also get a speed signal, which has to be fed back to the inverter to adjust the output data of the inverter.

　　Fault phenomenon: When the rotary encoder is broken (no output), the inverter cannot work normally and becomes very slow, and after a while, the inverter protects and displays "PG disconnect"...the combined action can only take effect. To make the electrical signal rise to a higher level and produce a square wave pulse without any interference, this must be processed by electronic circuits. Encoder pg wiring and parameters The connection mode between the vector inverter and the encoder pg must correspond to the encoder pg model. Generally speaking, the encoder PG model is divided into three types: differential output, open collector output and push-pull output.The signal transmission method must consider the interface of the inverter PG card, so choose the appropriate pg card model or set it reasonably.

The working principle and application of Italian ELTRA rotary encoders Italian ELTRA encoders are generally divided into incremental and absolute types, and they have the biggest difference: in the case of incremental encoders, the position is marked from the zero position The number of pulses at the beginning of the calculation is determined, and the position of the absolute encoder is determined by the reading of the output code. In a circle, the reading of the output code of each position is unique; therefore, when the power is disconnected, the absolute encoder is not separated from the actual position. If the power is turned on again, the position reading is still current and valid; 　Unlike incremental encoders, you must look for the zero mark.

　　Italian ELTRA ELTRA rotary encoder features:

　　①Output according to the rotation displacement of the shaft

　　 By combining with the shaft by the coupling, the rotation displacement can be directly detected.

　　②There is no need to return to origin when starting. (Only absolute type)

In the case of absolute type, the rotation angle is output in parallel as an absolute value. 　　③The rotation direction can be detected.

　　In the incremental type, the output time of phase A and B can be used, and in the absolute type, the direction of rotation can be grasped by increasing or decreasing the code.

　　④Please select the most suitable sensor according to the rich resolution and output model.

　　 According to the required accuracy, cost, connection circuit, etc., select the appropriate sensor.

　　 Rotary encoder is a speed displacement sensor integrating optical and electromechanical technology. When the rotary encoder shaft drives the grating disc to rotate, the light emitted by the light-emitting element is cut into intermittent light by the grating disc slit, and is received by the receiving element to generate an initial signal. After the signal is processed by the subsequent circuit, a pulse or code signal is output. It is characterized by small size, light weight, multiple varieties, complete functions, high frequency response, high resolution ability, small torque, low energy consumption, stable performance, reliable and long service life.

　　1, incremental encoder

　　 When the incremental encoder shaft rotates, there is a corresponding phase output. The determination of the direction of rotation and the increase or decrease of the number of pulses need to be realized with the help of the direction circuit and counter at the rear. The counting starting point can be set arbitrarily, and unlimited accumulation and measurement of multiple turns can be realized. It is also possible to use the Z signal for each pulse transmitted as a reference mechanical zero position. When the pulse is fixed and the resolution needs to be improved, two signals with a phase difference of 90 degrees A and B can be used to double the original pulse number.

　　2, absolute encoder

　　 In the case of absolute encoder shaft rotator, there is a code (binary, BCD code, etc.) output corresponding to the position one-to-one, and the positive and negative direction and the position of the displacement can be determined from the change of the code size, without the need to determine the circuit. It has an absolute zero code. When the power is cut off or turned off and then turned on and re-measured, the code of the power cut or shut down position can still be read accurately, and the zero code can be found accurately. Under normal circumstances, the measuring range of absolute encoders is 0-360 degrees, but special models can also achieve multi-turn measurement.

　　3, sine wave encoder

　　 Sine wave encoder is also an incremental encoder, the main difference is that the output signal is a sine wave analog signal, not a digital signal. Its appearance is mainly to meet the needs of the electrical field-as a feedback detection element for motors. On the basis of comparing with other systems, people can use this kind of encoder when people need to improve the dynamic characteristics.

In order to ensure good motor control performance, the feedback signal of the eltra rotary encoder must be able to provide a large number of pulses, especially when the speed is very low, the traditional incremental encoder is used to generate a large number of pulses. There is a problem. When the motor rotates at a high speed (6000rpm), it is difficult to transmit and process digital signals. In this case, the bandwidth required to process the signal to the servo motor (such as 10,000 pulses per revolution of the encoder) will easily exceed the MHz threshold; on the other hand, the use of analog signals greatly reduces the above-mentioned troubles and has the ability to simulate A large number of pulses from the encoder. This is thanks to the interpolation of sine and cosine signals, which provides a calculation method for the rotation angle. This method can obtain a high multiplication of the basic sine, for example, from 1024 sine wave encoders per revolution, more than 1,000,000 pulses per revolution can be obtained. The bandwidth required to receive this signal is only slightly greater than 100KHz. The interpolation frequency multiplication needs to be completed by the secondary system.