How to Adjust the Speed of Brushless Motor?

How to adjust the speed of brushless motor?

It is different from the speed regulation of stepper motors (the principle of speed regulation is to rotate a step angle every time a signal is received, so the speed regulation method of stepper motors is frequency speed regulation, that is, the speed of the motor is controlled by changing the frequency of the pulse signal. Adjusting the pulse signal voltage will not change the motor speed.) The brushless motor (bldc motor) has three speed adjustment methods:
 
1. Voltage speed regulation: Generally, a brushless motor is matched with a driver. By changing the output voltage of the driver, the input voltage of the brushless motor can be controlled to adjust the motor speed.
 

2. PWM speed regulation: PWM speed regulation uses pulse width modulation to modulate the constant DC power supply voltage into a pulse voltage sequence with a constant frequency and variable width, so that the average output voltage can be changed to adjust the motor speed. The speed can be adjusted by changing the voltage. Its essence is to adjust the duty cycle. Simply put, the duty cycle is the time ratio between high level and low level in the pulse signal. For example, assuming that the high level is 5V, the low level is 0V, and the duty cycle is 50%, that is half the high level time and half the low level time. At a certain frequency, you can get a simulated 2.5V Output voltage, then with a duty cycle of 75%, the resulting voltage is 3.75V.

The larger the duty cycle, the higher the output pulse amplitude, the larger the voltage, and the higher the rotational speed. On the contrary, the rotational speed will decrease. Therefore, when using PWM speed regulation, if the high-level amplitude is 5V and the amplitude is 3.3V, the motor's speed will only be 66% of the full speed. At this time, if a higher speed is needed, the maximum speed of the motor can be increased. Corresponding ratio to achieve the required speed.
 
3. Series resistor speed control: A potentiometer can be connected in series, but the method is inefficient and only small-power motors can be used. It is generally not recommended to use a potentiometer to regulate the speed of high-power motors.

How to Solve an Encoder Error in a Servo Motor?

An essential tool for determining the motor's speed and angular displacement is the servomotor encoder. However, frequent use or other factors could cause the encoder to malfunction. This post will discuss a few typical servo motor encoder problems and offer helpful maintenance advice.

1. Encoder signal loss: This can be brought on by a malfunctioning encoder, a damaged cable, or a bad cable connection. Replacing damaged cables, inspecting and re-connecting cables, and changing the encoder are some solutions.

2. Inaccurate encoder readings: This could be brought on by a dirty, damaged, or improperly calibrated encoder. Replacing the malfunctioning encoder, performing error calibration, and inspecting and cleaning the encoder are some solutions.

3. Vibration or noise from the encoder: This could be the result of a loose, unsteady, or broken encoder. Reinstalling the encoder, tightening it up, or changing the damaged encoder are some solutions.

4. Encoder feedback error: The mismatch between the actual position and the encoder output signal could be the cause. Recalibrating the encoder, examining and modifying the encoder feedback parameters, or swapping out the malfunctioning encoder are some of the solutions.

Furthermore, encoder abnormalities can arise during normal and no load conditions when using servo motors. At this point, it will seem as though there are errors or distortions in the encoder feedback data, which is why the servo motor isn't operating correctly.

The potential causes are the following:

1. Incorrect installation: In order to guarantee a steady and efficient feedback signal, the servo motor encoder must be mounted on the motor in the proper manner. An improper installation or looseness could lead to an encoder malfunction while it's working.

2. Magnetic pole reversal: Accuracy and matching between the servo motor encoder's rotor and stator are required. The encoder will not function correctly if there is magnetic pole reversal.

3. Damage to the encoder: During operation, the servo motor encoder is a relatively delicate component that is prone to damage. The encoder won't function correctly if it is damaged.

The following are the corresponding measures:

Examine the installation: The first thing to do when a servo motor encoder anomaly arises is to make sure the encoder is installed correctly and tighten the screws at the appropriate locations.

2. Verify the matching degree: The encoder and motor's matching degrees must be verified if magnetic pole reversal takes place. They must be changed if they don't match.

3. Replace the encoder: You should think about replacing the encoder if it has been damaged. Make sure you select the right brand and model and follow the right procedures when replacing an encoder.

The following considerations must be made when fixing the servo motor encoder:

1. Safety: To avoid unintentional harm, disconnect the power supply before beginning any maintenance and adhere to all applicable safety operating procedures.

2. Maintenance manual: To find out the precise maintenance procedures and safety measures, refer to the servo motor encoder's maintenance manual.

3. Tools and supplies: Get ready the necessary screwdrivers, wrenches, cleaners, and other supplies needed for the repair.

4. Debugging and testing: To make sure the encoder resumes normal operation after the repair is finished, carry out the necessary debugging and testing.

Pay attention to maintenance: During the long-term use of the servo motor, pay attention to regular maintenance of the motor and encoder to maintain their good condition.

Where can we use a servo motor?

1. Automated production line: Servo motors can be used to drive assembly lines, robotic arms, handling equipment, etc. and for automated product packaging/bottling and labeling, among others.
2. Logistics and transportation industry: For example, in large storage warehouses, there are many AGV vehicles used for transportation and deployment of goods, and they use servo motors for movement and steering.
3. Microelectronics production and processing: For example, the production of various types of chips requires mechanical arms driven by servo motors.
4. Robot technology: Servo motors are an indispensable part of robot technology. They are used for joint drive, arm movement, etc. of robots. They can achieve complex actions and precise motion control, giving robots higher flexibility and accuracy. .
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6. Camera autofocus: The high-precision servo motor built into the camera can correct the camera lens to sharpen out-of-focus images.

7. Solar tracking system: The servo motor adjusts the angle of the solar panels throughout the day so that each panel continues to face the sun, maximizing energy utilization from sunrise to sunset.
8. Automated processing equipment: Automated processing equipment usually needs to control parameters such as rotation speed, acceleration, power, etc., and servo motors can easily realize these functions. In automated processing equipment, servo motors can be used in precision grinders, drilling machines, lathes, cutting machines, cutting tables and other systems.

9. Textile machinery: The application of servo motors in textile machinery is mainly used for drive and control in manufacturing processes such as spinning, weaving, printing and dyeing.
10. Press/Printer: Servo motors stop and start the print head precisely on the page and move the paper to print multiple lines of text or graphics precisely.

11. Automatic door openers: Supermarket and hospital entrances are prime examples of automatic door openers controlled by servo motors, whether the door opening signal is sent through a push plate next to the door for disabled people or through a radio transmitter located overhead.

12. Aircraft field: For example, in aircraft aviation control systems, servo motors can be used in systems such as wing control, automatic navigation, and flight control stability.
13. Intelligent transportation: Servo motors are used in signal lights, vehicle navigation, automatic driving, etc. in intelligent transportation systems to improve the efficiency and safety of traffic flow through precise control and response capabilities. 

14. Clean energy: Servo motors play an important role in the clean energy industry, such as solar tracking devices, wind power equipment, etc., used to accurately adjust the angle of solar panels and wind turbines to maximize the capture and utilization of renewable energy.