Sensor with non-uniform distribution of magnetic flux for multiple magnetic blocks in casing

Abstract

The invention discloses a sensor with non-uniform distribution of magnetic flux for multiple magnetic blocks in a casing and belongs to a technology of providing a control signal by multi-point induction. The sensor comprises a sensing element, an assisting model processor, a digital / analogue converter and an operational amplifier which are sequentially connected, wherein the sensing element comprises permanent magnet blocks and a Hall which are arranged in an inner hollow casing formed by embedding a fixed disk with a rotary disk; a plurality of permanent magnet blocks which are annularly distributed are fixedly arranged on the rotary disk; magnetic fluxes of at least two permanent magnet blocks on a certain surface of the rotary disk are different; magnetic polarities of adjacent permanent magnets on the certain surface of the rotary disk are opposite, i.e., the magnet polarity distribution mode of all permanent magnet blocks on the certain surface is N pole, S pole, N pole and the like; and the Hall on the fixed disk is arranged at a position close to the permanent magnet block. The sensor has the advantages that the magnetic polarity is in an NS distribution mode, so that the Hall can acquire a rectangular wave signal which can be used for digital processing of the set assisting model, expressing the position of the permanent magnet blocks on the rotary disk and determining applications of different rectangular waves; and a relative position between the permanent magnet blocks and the Hall is fixed, and thus the reliability in signal output is realized.

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

[0017] Disadvantages (3) The combined control signal is prone to signal drift, which makes the combined control signal not match the motor controller, and the power-assisted demand model is distorted: due to changes in ambient temperature and use time After a long period of time, the sensing parameters of the three Halls may vary greatly, and the connection points of the three control signals of the three Halls will inevitably change, so the combined control signals generated by the same boosting demand will produce segmental signal drift. Combining the control signals as a whole produces signal distortion, that is, the power-assist demand model is distorted, causing the motor controller to choose any one of the three control signals as a reference, resulting in the inconsistency between the power-assisted output and the power-assisted demand

[0018] Disadvantage (4) The sensing points cannot be increased arbitrarily. If there are too few sensing points, the motor will not run smoothly, making the rider feel very uncomfortable: due to the disadvantages (1) and (2) are the most important The number of halls is greater than one. Obviously, the more the number of halls, the more serious the shortcomings (1) and (2) are.

Therefore, the power-assisted bicycle provided by this patent can only be a very bad power-assisted bicycle that makes the rider feel comfortable.

[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.

Images