Sensor with a plurality of magnet positions and magnetic flux both unevenly distributed in housing

Abstract

The invention provides a sensor with a plurality of magnet positions and magnetic flux both unevenly distributed in a housing, belonging to the technology of providing a control signal through multi-point position magnetic induction. The sensor comprises a sensing element, a power model processor, a digital-to-analogue converter and an operational amplifier which are sequentially connected, wherein the sensing element comprises a rotating disc and a fixed disc; permanent magnets and a hall are embedded in the inner cavity of the fixed disc; a plurality of permanent magnets different in spacing and magnetic flux are fixedly arranged on the rotating disc; the adjacent permanent magnets are opposite in magnetic polarity, namely, the distribution manner of the magnetic polarities of all permanent magnets on one surface of the rotating disc are pole N, pole S, pole N...; and the hall on the fixed disc is arranged in a position in the vicinity of the permanent magnets. The sensor has the following advantages that the magnetic polarities are in N-S distribution so that the hall is capable of obtaining a rectangular wave signal, which can be added for digital processing of a set power model; the rectangular wave signal is capable of indicating the positions of the permanent magnets on the rotating disc; therefore, the uses of different rectangular waves are determined; and the relative positions of the permanent magnets and the hall are fixed and the signal output is reliable.

Description

technical field [0001] The invention belongs to the technical field of providing signals by magnetic induction, and in particular relates to the technology of providing control signals by multi-point magnetic induction on a rotating component. Background technique [0002] The Chinese patent 201020295192.0 "Claw Type Torque Sensing Device" applied by Yebao Vehicle Material Industry (Kunshan) Co., Ltd. discloses a sensing device for power-assisted bicycles. The sensing device includes a magnetic part and an elastic part to sense the torque. sensing device. After a long time of use, the change of the elastic coefficient of the elastic member will lead to changes in the sensing signal and the control effect of the controlled motor, and the power-assisted effect will not match the power-assisted needs of people. Moreover, the design structure of the elastic member is complex and the manufacturing cost is high. [0003] The Chinese patent 01201843.0 "Automatic Detection Device ...

AI Technical Summary

Problems solved by technology

[0015] Disadvantages (1) Using two permanent magnets with no difference to represent the fixed positions of the two pedals, only multiple Halls can be used to represent the pedals Rotation position: There is no difference between the two permanent magnets. The advantage is that the fixed positions of the two pedals can be expressed regardless of the left and right feet, so that the left and right feet can generate power assistance requirements, which can produce the same motor power assistance effect; but the disadvantage is that The permanent magnetic steel itself cannot indicate the rotation position of the pedal, but can only use multiple Halls at different corner positions to indicate the rotation position of the pedal, so it is not possible to use only one Hall, but must use multiple Halls

[0016] Disadvantage (2) Only one Hall cannot be used, but three Halls will inevitably cause the original segmentation error of the three control signals, which will distort the power-assist demand model, naturally The generation of power output is inconsistent with the demand for power assistance: no matter whether the power-assisted bicycle has one or two motors, the sensor signal for controlling the motor can only be controlled by using one sensor signal input to the motor controller; and the patent uses three sensors. If Hall controls the motor, the three control signals of the three Halls must be combined into one combined control signal before it can be input to the motor controller

The sensing parameters of the three Halls cannot be the same, especially due to changes in ambient temperature and long-term use, the sensing parameters of the three Halls may vary greatly. The output voltages are different, resulting in different power output of the motor, and the power output is inconsistent with the power demand; similarly, when the power demand is the same, the outputs of different Halls may be the same voltage, resulting in the same power output of the motor, and also There is a problem that the power output is inconsistent with the power demand

[0019] Disadvantages (5) The signal blind area reaches 42 degrees, and when the power is needed when starting, it is impossible to get it: as we all know, the torque of the bicycle pedal is the smallest at the apex , from the angle of 10-45 degrees away from the top is the area that needs the most assistance, but the angle between the Halls in this patent is 42.5-43.5 degrees, and there is no Hall in the area of ​​10-42 degrees away from the top of the pedal. There is no control signal, and the result is when the assist is most needed, but the motor of the assist bicycle cannot assist

[0020] In short, this patent is a technical solution for using multiple Halls to control the booster mode, because only multiple Halls can be used to represent the rotation position of the pedal, and the multiple control signals of multiple Halls must have original errors, and the combined control signals It is also easy to produce signal drift, which can cause distortion of the assist demand model, that is, the same assist demand at different times, but different assist effects; the more the number of Halls, the more serious the distortion of the assist demand model, limiting the number of Halls , a small amount of Hall will cause the motor to run unsteadily, making the rider feel very uncomfortable, and will not get assistance when starting

To make it undistorted to help the demand model, and to ensure the smooth operation of the motor, there are always two issues. It is impossible to have both.

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