Brushless motor rotor detection device, determination and calculation method and fitness chest expander

Abstract

The invention discloses a brushless motor rotor detection device, a determination and calculation method and a fitness chest expander, and belongs to the technical field of motor equipment. The motor rotor position detection method comprises the following steps: obtaining a voltage offset value of a sensor according to a voltage extreme value and a voltage scale value detected by the sensor; calculating to obtain a scaling coefficient of the sensor by using the voltage deviation value and the electric period value; calculating an electrical angle increment through the zoom coefficient and the sensor detection amplitude; adding the electrical angle increment and the partition initial value to obtain a relative electrical angle; and acquiring an absolute electrical angle according to the relative electrical angle and the initial offset angle of the rotor to realize motor rotor position detection. According to the method, the scaling coefficient is introduced, so that the calculation error is reduced, and meanwhile, the detection method has feasibility. And meanwhile, accurate detection of the position of the motor rotor is realized by calculating a voltage deviation value, an electrical angle increment, a relative electrical angle and an absolute electrical angle.

Description

technical field [0001] The invention relates to a brushless motor rotor detection device, a determination and calculation method, and a fitness tensioner, belonging to the technical field of motor equipment. Background technique [0002] Permanent magnet brushless DC motor (BLDC) uses FOC control to obtain accurate rotor angle information. The traditional methods include the non-inductive method using back EMF detection, the inductive method using multiple switching Hall sensors or the use of magnetic encoders. However, these methods all have obvious shortcomings. The non-inductive method needs to detect the back electromotive force of each phase during the rotation of the motor, which has great interference, large error in the calculated angle information and high algorithm complexity, so it cannot achieve low Speed ​​stability control. The method of using the switch Hall sensor only obtains discrete angle information in one rotation cycle, and the electrical angle needs t...

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Problems solved by technology

However, these methods have obvious shortcomings. The non-inductive method needs to detect the back electromotive force of each phase during the rotation of the motor, and the interference is very large. The error of the calculated angle information is large and the complexity of the algorithm is high. speed stabilization control

The method of using the switch Hall sensor only obtains discrete angle information in one rotation cycle, and the electrical angle needs to be estimated, and the same error is too large to achieve stable control at low speeds.

Although the method of using a magnetic encoder can provide accurate angle information, it needs to install a special magnet on the rotor shaft to cooperate with the detection, which has high requirements on the structure and high cost, and can only be applied to a few scenarios

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