Rotor position sensing method of brushless motor of electric bicycle

Abstract

The invention provides a rotor position sensing method of a brushless motor of an electric bicycle. The method comprises steps that the direct current is supplied to two phases of windings of a statorunit, when a to-be-fixed rotor unit is attracted by the magnetic force of a magnetic field excited by a stator unit coil to pivot till being fixed, a sensing module is utilized for obtaining the angle position of a sensing magnet, a pivoting angle theta of the angle position of the sensing magnet relative to the reference position is calculated, then, the number of magnetic poles of the rotor unit is inputted into the sensing module, the sensing module carries out operation according to the number of magnetic poles of the rotor unit and the pivoting angle theta, and lastly, a control unit receives operation data of the sensing module and controls a brushless motor according to the operation data and the real-time information, sensed by the sensing module, of the position of the sensing magnet.

Description

technical field [0001] The present invention relates to a sensing method of an electric bicycle, in particular to a rotor position sensing method of a brushless motor of the electric bicycle. Background technique [0002] In recent years, due to the improvement of health and environmental awareness, mobile vehicles such as electric bicycles that are both sporty and do not emit exhaust gas have been loved by many people. Most of the current electric bicycles have motors installed on the bottom bracket or front and rear wheels. At the wheel shaft, the motor drives the chain or the wheel to reduce the user's physical burden. However, the quality of the motor will not only affect the conversion efficiency of power, but also affect the smoothness of riding, which has a very important position. . [0003] Compared with traditional brushed motors, brushless motors have higher efficiency and torque density, and are therefore widely used in electric bicycles. In order to accurately ...

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Problems solved by technology

[0003] Compared with traditional brushed motors, brushless motors have higher efficiency and torque density, and are therefore widely used in electric bicycles. In order to accurately grasp the pivot position of the rotor to maintain the commutation of the continuity of the magnetic poles on the stator demand, the current practice is to install three Hall sensors between the teeth of the stator, and use the signals obtained by the Hall sensors to infer the pivoting position of the rotor. The relative position has quite strict requirements, and wrong or deviation placement will cause the calculated rotor position to be inconsistent with the actual position, which will lead to inaccurate phase switching of the stator, reduced motor operation efficiency or turbulence, so manufacturers often need to spend A lot of manpower and time are spent on the alignment and calibration process of each Hall sensor

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