Rotor Position Sensing Method for Brushless Motor of Electric Bicycle

Abstract

A method for sensing the rotor position of a brushless motor of an electric bicycle. In this method, a direct current is first passed to the two-phase windings of the stator unit, and the rotor unit is pivoted until it is fixed by the magnetic force of the magnetic field excited by the coil of the stator unit. Then use the sensing module to obtain the angular position of the sensing magnet, and calculate the pivot angle θ between the angular position of the sensing magnet and the reference position, and then input the number of magnetic poles of the rotor unit into the sensing module, and the sensing module The operation is performed according to the number of magnetic poles and the pivot angle θ of the rotor unit. Finally, the control unit receives the operation data from the sensing module and controls the brushless motor based on the real-time information of the position of the sensing magnet sensed by the sensing module.

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 ...

AI Technical Summary

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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