1.Working principle of stepper motor encoder
The working principle of stepper motor encoder is mainly to convert electrical pulse signal into corresponding angular displacement or linear displacement. For each input pulse signal, the rotor of the stepper motor will rotate a fixed angle or move forward one step. The output angular displacement or linear displacement is proportional to the number of input pulses, and the speed is proportional to the pulse frequency. Stepper motor encoders are usually used in applications that require precise control of position and speed. It drives the motor to rotate by receiving electrical pulse signals, and the position and speed information of the motor can be read by external devices.
2.Main classification of stepper motor encoders
1.Photoelectric encoder: Use photoelectric sensors and encoder disks to measure the position and movement of the rotor. The grating or encoding hole on the encoder disk is sensed by the photoelectric sensor to measure the angle and position of the rotor. Photoelectric encoders have high precision, good compatibility, and are not easily disturbed by external magnetic fields. They are widely used in stepper servo motor systems that require high-precision position measurement.
2.Magnetic encoder: Use magnetic sensors and magnetic scales to detect the position and movement of the rotor. The interaction between the magnetic strip on the magnetic scale and the magnetic sensor is used to measure the angle and position. It is suitable for stepper servo motor systems with certain requirements for accuracy and stability.
3.Grating scale encoder: A high-precision encoder based on the grating scale, which uses the interaction between the grating texture on the grating scale and the photoelectric sensor to provide very accurate position measurement. It is often used in stepper servo motor systems with extremely high accuracy requirements.
4.Magnetic scale encoder: A high-precision encoder based on magnetic technology, which uses the interaction between the magnetic texture on the magnetic scale and the magnetic sensor to provide high-precision position measurement. It is particularly suitable for stepper servo motor systems with extremely high requirements for accuracy and stability.
3.Connection method of stepper motor encoder
1.Single-axis wiring diagram: The principle is that the 24V power supply is connected to the positive and negative poles of the stepper motor, and the 5V power supply is connected to the pulse and direction input terminals. The specific wiring method is: the brown wire of the 24V power supply is connected to the positive pole, the blue wire is connected to the negative pole, and the yellow and green wires are grounded; the two sets of wires of the motor are connected to the A+ and A-, B+ and B- of the driver; the negative pole of the 24V power supply is connected to the GND of the driver, and the positive pole is connected to the VDC of the driver; the red and green wires of the encoder are connected to the PUL- and DIR- of the driver, the black wire is connected to GND, and the white wire is connected to DIR+12.
2.Two-axis wiring diagram: The pulse and direction connection is the pulse and direction input terminal of stepper motor 2, and the pulse of stepper motor 1 is also connected to the 5V power supply2.
3.Four-axis wiring diagram: The principle is that Y1, Y2, Y3, and Y4 are used as pulse outputs, and Y5, Y6, Y7, and Y8 are used as direction control. The specific wiring method is: the pulse output line is connected to the corresponding pulse input terminal, and the direction control line is connected to the corresponding direction input terminal.
4.Main functions of stepper motor encoders
1.Measuring position: Stepper motor encoders can accurately calculate the current position of the motor. By processing photoelectron signals, the encoder can measure the rotation angle of the motor to determine the specific position of the motor.
2.Measuring speed: The encoder can measure the speed of the motor by calculating the position change of the motor at each moment. This is very important for applications such as high-precision positioning, motion control, and adaptive control, and can help the system adjust control parameters in real time to improve motion accuracy and positioning accuracy.
3.Improving motion control accuracy: The encoder can provide deterministic feedback signals to ensure accurate position control and eliminate errors caused by load changes or environmental factors. In addition, by providing more accurate speed feedback information, the encoder can improve the motor's motion performance and reduce noise and vibration.
4.Preventing lost steps: In stepper motors, encoders can prevent the motor from losing steps. Through a closed-loop control system, the encoder can monitor the position and speed of the motor in real time to ensure that the motor runs according to the preset number of steps and avoid errors caused by insufficient or excessive number of steps.
5.Synchronous control: In a multi-motor system, the encoder can help synchronize the movement of different motors, ensure that each motor runs in a preset order and speed, and improve the overall coordination and stability of the system.
6.Fault diagnosis: The encoder can also be used to monitor abnormal conditions of the motor, such as overspeed, jamming, etc. By monitoring the output signal in real time, the system can detect and handle these abnormal conditions in time to ensure the normal operation of the equipment.
7.Data acquisition: The encoder can output digital signals, analog signals or pulse signals for connection to a data acquisition system or controller to achieve real-time data acquisition and monitoring.
