Self-balancing method and device for coil of torque sensor

Abstract

The invention relates to a self-balancing method and device for a coil of a torque sensor, the torque sensor comprises a torque processing module, and the method comprises the following steps: generating an initial control signal to control the torque processing module to generate a first direct current signal and a second direct current signal; and judging the first direct current signal and the second direct current signal: when the amplitude of the first direct current signal is different from that of the second direct current signal, adjusting the torque sensor to enable the amplitude of the first direct current signal to be the same as that of the second direct current signal. And processing the first direct current signal and the second direct current signal to obtain a torque signal.

Description

Technical Field

[0001] The present application relates to the field of torque sensors, and in particular to a self-balancing method and device for a coil of a torque sensor. Background Art

[0002] Most current power-assisted bicycles use torque sensors to detect the pressure applied by the rider on the pedals. Figure 1 As shown, the realization principle of the torque sensor is based on series LC resonance. A fixed frequency excitation signal is sent through a microcontroller unit (MCU) 101, and oscillates through a coil module 102 composed of two coils and an amorphous alloy to generate two sets of sinusoidal signals. Then, the analog signal is converted into a digital signal collected by the MCU through a post-stage torque processing module 103, and the final torque signal is output through internal signal processing of the MCU.

[0003] When the torque is applied to the amorphous alloy in the coil module, the alloy part deforms, causing the inductance of the two coils inside the coil module to change relatively, which is specifically manifested as an increase or decrease in the amplitude of the two sets of sinusoidal signals. The two sets of sinusoidal signals pass through two completely symmetrical torque processing modules to generate two sets of DC signals, which are then differentially amplified by the instrument amplifier to generate the original torque signal. However, due to the shortcomings of the structural process, there is a difference between the consistency of the coil and the consistency of the amorphous alloy, resulting in the inability to maintain the same amplitude of the two sinusoidal signals in front of the torque processing module under no force. Summary of the invention

[0004] In order to solve the problem that the two sinusoidal signals output by the coil of the traditional torque sensor cannot remain consistent when no force is applied, the present application proposes a self-balancing method for the coil of the torque sensor, wherein the torque sensor includes a torque processing module, including: generating an initial control signal to control the torque processing module to generate a first DC signal and a second DC signal; judging the first DC signal and the second DC signal: when the amplitudes of the first DC signal and the second DC signal are different, adjusting the torque sensor so that the amplitudes of the first DC signal and the second DC signal are the same; processing the first DC signal and the second DC signal to obtain a torque signal.

[0005] Optionally, the initial control signal includes:

[0006] An initial adjustable signal, used to generate a first excitation signal;

[0007] A first initial excitation signal, used to generate a second excitation signal;

[0008] The first excitation signal and the second excitation signal have the same amplitude, frequency and phase.

[0009] Optionally, the initial adjustable signal is a pulse width modulation signal with an adjustable signal duty cycle, and adjusting the torque sensor includes adjusting the signal duty cycle of the initial adjustable signal.

[0010] Optionally, the initial control signal includes a second initial excitation signal.

[0011] Optionally, adjusting the torque sensor includes adjusting a resistance of a circuit that generates the first DC signal and / or the second DC signal.

[0012] Optionally, the coil receives the first excitation signal and the second excitation signal to generate a first sinusoidal signal and a second sinusoidal signal.

[0013] Optionally, the coil receives the second initial excitation signal to generate a first sinusoidal signal and a second sinusoidal signal.

[0014] Optionally, the torque processing module receives the first sinusoidal signal and the second sinusoidal signal to generate the first DC signal and the second DC signal.

[0015] The present application also proposes a self-balancing device for a coil of a torque sensor, wherein the torque sensor includes a torque processing module, including: a control module, used to generate an initial control signal to control the torque processing module to generate a first DC signal and a second DC signal; a self-balancing module, used to judge the first DC signal and the second DC signal: when the amplitudes of the first DC signal and the second DC signal are different, adjust the torque sensor to adjust the first DC signal and / or the second DC signal until the amplitudes of the first DC signal and the second DC signal are the same; a signal processing module, used to process the first DC signal and the second DC signal to obtain a torque signal.

[0016] Optionally, the device further includes: an excitation signal generating module, configured to receive the initial control signal and generate the first excitation signal and the second excitation signal; wherein the initial control signal includes:

[0017] An initial adjustable signal, used to generate a first excitation signal;

[0018] A first initial excitation signal, used to generate a second excitation signal;

[0019] The first excitation signal and the second excitation signal have the same amplitude, frequency and phase.

[0020] Optionally, the initial adjustable signal is a pulse width modulation signal with an adjustable signal duty cycle, and the signal duty cycle is adjusted by the control module to adjust the amplitude of the initial adjustable signal.

[0021] Optionally, the excitation signal generating module includes:

[0022] A low-pass filter, used for filtering the AC signal component in the initial adjustable signal;

[0023] an operational amplifier for amplifying the filtered initial adjustable signal and acting as a voltage follower to output the second excitation signal having the same amplitude as the first initial excitation signal;

[0024] The analog switch is used to receive the amplified initial adjustable signal to generate the first excitation signal.

[0025] Optionally, the device further comprises: a potentiometer; wherein the adjusting the torque sensor comprises adjusting the resistance of a circuit generating the first DC signal and / or the second DC signal by means of the potentiometer. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of an existing torque sensor.

[0027] Figure 2 It is a flow chart of a self-balancing method for a coil of a torque sensor according to an embodiment of the present application.

[0028] Figure 3 It is a structural schematic diagram of a torque sensor using the method described in the present application according to an embodiment of the present application.

[0029] Figure 4 It is a partial structural schematic diagram of a torque sensor using the method described in the present application according to an embodiment of the present application.

[0030] Figure 5 It is a structural schematic diagram of a torque sensor using the method described in the present application according to an embodiment of the present application.

[0031] Figure 6 It is a structural schematic diagram of a torque processing module having a coil self-balancing module disposed therein according to an embodiment of the present application.

[0032] Figure 7 is a schematic diagram of a self-balancing device for a coil of a torque sensor according to an embodiment of the present application. DETAILED DESCRIPTION

[0033] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below in conjunction with the accompanying drawings.

[0034] Figure 2 This is a flow chart of the self-balancing method for the coil of the torque sensor proposed in the present application. In step 201, an initial control signal is generated to control the torque processing module to generate the first DC signal and the second DC signal. It can be understood that the initial control signal is not directly used to control the torque processing module to generate the first DC signal and the second DC signal, and the specific process will be described in detail later.

[0035] In step 202, the first DC signal and the second DC signal are judged: when the amplitudes of the first DC signal and the second DC signal are different, the torque sensor is adjusted so that the amplitudes of the first DC signal and the second DC signal are the same. As mentioned above, if the amplitudes of the first DC signal and the second DC signal generated by the torque processing module are different, it indicates that there is an inconsistency problem in the coils. Therefore, the torque sensor needs to be adjusted to compensate for the amplitude difference caused by the inconsistency of the coils so that the amplitudes of the first DC signal and the second DC signal are the same, so as to ensure the accuracy of the torque sensor. It can be understood that adjusting the torque sensor means adjusting the internal components of the torque sensor, and different components can be adjusted in different specific embodiments.

[0036] In step 203, the first DC signal and the second DC signal are processed to obtain a torque signal. In practice, the first DC signal and the second DC signal with the same adjusted amplitude are differentially amplified by an instrumentation amplifier in a torque processing module to output an original torque signal, which is then transmitted to an MCU of the torque sensor for processing to obtain the final required torque signal.

[0037] Next reference Figure 3-Figure 6 The method is described in detail with reference to the structural schematic diagram of the torque sensor using the method.

[0038] Figure 3 This is an embodiment of a torque sensor using the method. The torque sensor includes an MCU 301 , a coil self-balancing module 302 , a coil module 303 and a torque processing module 304 . Figure 4 30 is a schematic diagram of the structure from MCU 301 to the internal structure of the coil self-balancing module 302 and then to the coil module 303, wherein the internal structure of the coil self-balancing module 302 includes a second-order low-pass filter 3031, an operational amplifier 3032 and an analog switch 3033.

[0039] MCU 301 generates an initial adjustable signal and inputs it to coil self-balancing module 302. In this embodiment, the initial control signal includes an initial adjustable signal and a first initial excitation signal. The initial adjustable signal is a pulse width modulation (PWM) signal with an adjustable duty cycle, and the initial duty cycle is preferably 50%. The initial adjustable signal is input into a second-order low-pass filter 3031 to convert the PWM signal in square wave form into a DC signal, which is input into an operational amplifier 3032 for amplification. The amplified signal is output as a first excitation signal through an analog switch 3033. The first initial excitation signal is input into the operational amplifier 3032 to output a second excitation signal identical to the first initial excitation signal using the voltage follower function of the operational amplifier 3032. The opening and closing of the analog switch 3033 is controlled by the first initial excitation signal. For example, when the MCU 301 outputs the first initial excitation signal, that is, when a high level is input to the analog switch 3033, the analog switch 3033 is closed, and the path is turned on to output the first excitation signal and the second excitation signal; when the first initial excitation signal is stopped, the analog switch 3033 is disconnected, and no signal is output. Thus, the first initial excitation signal can ensure that the first excitation signal and the second excitation signal are square waves with the same frequency and phase. It can be understood that the initial adjustable signal, the first initial excitation signal, and the amplification factor of the operational amplifier 3032 can be optional, as long as the amplitude, frequency, and phase of the output first excitation signal and the second excitation signal are the same, and the first excitation signal and the second excitation signal are preferably 3.3V square wave signals.

[0040] When the first excitation signal and the second excitation signal are input to the coil module 303, the coil module 303 generates a first sinusoidal signal and a second sinusoidal signal, and inputs them to the torque processing module 304. After receiving the first sinusoidal signal and the second sinusoidal signal, the torque processing module generates a first DC signal and a second DC signal. It can be understood that, for the convenience of explanation, there is a corresponding generation relationship between the initial adjustable signal, the first excitation signal, the first sinusoidal signal and the first DC signal, and there is a corresponding generation relationship between the first initial excitation signal, the second excitation signal, the second sinusoidal signal and the second DC signal.

[0041] Under ideal conditions (i.e., the coil consistency and the amorphous alloy consistency are good), since the amplitude, frequency and phase of the first excitation signal and the second excitation signal are the same, the amplitude of the first sinusoidal signal and the second sinusoidal signal are also the same, and thus the amplitude of the first DC signal and the second DC signal are also the same. However, when there are structural differences between the coil and the amorphous alloy, the amplitudes of the first DC signal and the second DC signal will be different. Therefore, after the first DC signal and the second DC signal are generated, the amplitudes thereof need to be judged by MCU 301, and if the judgment result is that the amplitudes are different, the torque sensor needs to be adjusted to make them the same. In this embodiment, since the initial adjustable signal is a PWM signal, the amplitude of the initial adjustable signal can be easily adjusted by adjusting the duty cycle of the PWM signal, thereby adjusting the amplitudes of the first excitation signal and the first sinusoidal signal generated by the initial adjustable signal, and finally adjusting the amplitude of the first DC signal. Specifically, when the amplitude of the first DC signal is less than the amplitude of the second DC signal, the duty cycle of the initial adjustable signal is increased to increase the amplitude of the initial adjustable signal, thereby increasing the amplitude of the first DC signal; when the amplitude of the first DC signal is greater than the amplitude of the second DC signal, the duty cycle of the initial adjustable signal is reduced to reduce the amplitude of the initial adjustable signal, thereby reducing the amplitude of the first DC signal. Finally, the first DC signal and the second DC signal with the same adjusted amplitude are differentially amplified by the instrumentation amplifier of the torque processing module 304 to obtain an initial torque signal, and the initial torque signal is input into the MCU 301 to obtain the final required torque signal.

[0042] Through the method described in this embodiment and the corresponding example sensor, the consistency requirements for the coil module are reduced. In addition, through the setting of the coil self-balancing module, two sets of excitation signals with different amplitudes and the same frequency can be generated by adjusting the amplitude of the initial control signal (that is, it can be used as a square wave signal generator to generate two signals with different amplitudes, the same frequency, and the same phase), thereby offsetting the errors caused by the parameters of the lower coil module itself. In addition, by using PWM signal as a control signal, all coil modules can be compatible to ensure that the torque sensor device is in normal working mode.

[0043] The above method performs self-balancing by adjusting the amplitude of the initial control signal. In another embodiment, the first DC signal and the second DC signal may be adjusted directly before being input to the instrumentation amplifier. Figure 5In another embodiment of the torque sensor using the method shown, the torque sensor includes an MCU 501, a coil module 502, a first torque processing module 5031, a second torque processing module 5032, and a coil self-balancing module 504 disposed in the torque processing module 503. It can be understood that the first torque processing module 5031 and the second torque processing module 5032 are the same torque processing module, which is divided into two parts only for the convenience of description. Figure 6 It is a structural schematic diagram of a torque processing module with a coil self-balancing module disposed therein, which includes two paths with the same structure, each path includes a DC signal generating module 601, and each path can be provided with a coil self-balancing module 504. The first DC signal and the second DC signal generated by the DC signal generating module 601 are input into the instrument amplifier 602 to generate an initial torque signal after passing through the coil self-balancing module 504.

[0044] In this embodiment, the initial control signal output by the MCU 501 includes a second initial excitation signal. Similarly, after receiving the second initial excitation signal, the coil module 502 generates a corresponding first sine signal and a second sine signal, and inputs them into the first torque processing module 5031 to generate a first DC signal and a second DC signal. Then, the amplitude of the first DC signal and the second DC signal is determined by the MCU 501. When the amplitudes of the first DC signal and the second DC signal are different, the amplitude of any one of the first DC signal or the second DC signal can be adjusted by the coil self-balancing module 504. It is understandable that the amplitudes of the two signals can also be adjusted at the same time. The coil self-balancing module 504 is preferably a potentiometer, and the amplitude of the first DC signal or the second DC signal can be easily adjusted by adjusting the resistance of the circuit that generates the first DC signal and / or the second DC signal. Then, the adjusted first DC signal and the second DC signal with the same amplitude are input into the instrument amplifier in the second torque processing module 5032 to obtain the initial torque signal. The initial torque signal is input into the MCU 501 to calculate the required torque signal.

[0045] Through the above embodiment, the coil self-balancing module can be used to solve the problem of inconsistent amplitudes of the two sinusoidal signals output by the coil module when the consistency of the coil and the amorphous alloy is insufficient, and two DC voltage signals with arbitrary difference can be generated, thereby offsetting the errors caused by the coil module's own parameters.

[0046] The present application also proposes a self-balancing device for a coil of a torque sensor, such as Figure 7As shown. The torque sensor includes a torque processing module, and the self-balancing device includes: a control module 701, which is used to generate an initial control signal to control the torque processing module to generate a first DC signal and a second DC signal; a self-balancing module 702, which is used to judge the first DC signal and the second DC signal: when the amplitudes of the first DC signal and the second DC signal are different, the torque sensor is adjusted to adjust the first DC signal and / or the second DC signal until the amplitudes of the first DC signal and the second DC signal are the same; a signal processing module 703, which is used to process the first DC signal and the second DC signal to obtain a torque signal.

[0047] The device further includes: an excitation signal generating module, which is used to receive an initial control signal and generate a first excitation signal and a second excitation signal; wherein the initial control signal includes:

[0048] An initial adjustable signal, used to generate a first excitation signal;

[0049] A first initial excitation signal, used to generate a second excitation signal;

[0050] In one embodiment, the initial adjustable signal is a pulse width modulation signal with an adjustable signal duty cycle, and the signal duty cycle is adjusted by the control module to adjust the amplitude of the initial adjustable signal.

[0051] In one embodiment, the excitation signal generating module includes:

[0052] A low-pass filter, used for filtering the AC signal component in the initial adjustable signal;

[0053] an operational amplifier for amplifying the filtered initial adjustable signal and acting as a voltage follower to output a second excitation signal having the same amplitude as the first initial excitation signal;

[0054] The analog switch is used for receiving the amplified initial adjustable signal to generate a first excitation signal.

[0055] In one embodiment, the device further comprises: a potentiometer; wherein adjusting the torque sensor comprises adjusting the resistance of a circuit for generating the first DC signal and / or the second DC signal by means of the potentiometer.

[0056] The device can utilize the aforementioned method to self-balance the coil of the torque sensor.

[0057] The above specific embodiments illustrate the implementation of the present application, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Although the description of the present application will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this invention are limited to the implementation. In addition, in order to avoid confusion or blurring the focus of the present application, some specific details will be omitted in the description. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0058] Furthermore, various operations will be described as multiple discrete operations in a manner that is most helpful for understanding the illustrative embodiments; however, the order of description should not be construed as implying that these operations are necessarily order dependent. In particular, these operations do not need to be performed in the order presented.

[0059] Unless the context dictates otherwise, the terms "comprising," "having," and "including" are synonymous. The phrase "A / B" means "A or B." The phrase "A and / or B" means "(A and B) or (A or B)."

[0060] As used herein, the term "module" or "unit" may refer to, be or include: an application specific integrated circuit (ASIC), an electronic circuit, a (shared, dedicated or group) processor and / or memory that executes one or more software or firmware programs, a combinational logic circuit and / or other suitable components that provide the described functionality.

[0061] In the accompanying drawings, some structural or method features are shown in a specific arrangement and / or order. However, it should be understood that such a specific arrangement and / or order may not be required. In some embodiments, these features may be arranged in a manner and / or order different from that shown in the illustrative drawings. In addition, the inclusion of structural or method features in a specific figure does not mean that such features are required in all embodiments, and in some embodiments, these features may not be included or may be combined with other features.

[0062] It should be understood that although the terms "first", "second", etc. may be used here to describe various units or data, these units or data should not be limited by these terms. These terms are used only to distinguish one feature from another. For example, without departing from the scope of the exemplary embodiment, a first feature may be referred to as a second feature, and similarly, a second feature may be referred to as a first feature.

[0063] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0064] While the present invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

Claims

1. A method for self-balancing a coil for a torque sensor, wherein: The torque sensor comprises a torque processing module, wherein the method comprises: generating an initial control signal to control the torque processing module to generate a first DC signal and a second DC signal; The first DC signal and the second DC signal are judged: When the amplitudes of the first DC signal and the second DC signal are different, adjusting the torque sensor so that the amplitudes of the first DC signal and the second DC signal are the same; The first DC signal and the second DC signal are processed to obtain a torque signal.

2. The method according to claim 1, characterized in that The initial control signal includes: An initial adjustable signal, used to generate a first excitation signal; A first initial excitation signal, used to generate a second excitation signal; The first excitation signal and the second excitation signal have the same amplitude, frequency and phase.

3. The method according to claim 2, characterized in that The initial adjustable signal is a pulse width modulation signal with an adjustable signal duty cycle, and the adjusting of the torque sensor includes adjusting the signal duty cycle of the initial adjustable signal.

4. The method according to claim 1, characterized in that The initial control signal includes a second initial excitation signal.

5. The method according to claim 4, characterized in that The adjusting the torque sensor includes adjusting a resistance value of a circuit that generates the first DC signal and / or the second DC signal.

6. The method according to claim 2, characterized in that The coil receives the first excitation signal and the second excitation signal to generate a first sinusoidal signal and a second sinusoidal signal.

7. The method according to claim 4, characterized in that The coil receives the second initial excitation signal to generate a first sinusoidal signal and a second sinusoidal signal.

8. The method according to claim 6 or 7, characterized in that: The torque processing module receives the first sinusoidal signal and the second sinusoidal signal to generate the first DC signal and the second DC signal.

9. A self-balancing device for a coil of a torque sensor, wherein: The torque sensor comprises a torque processing module, characterized in that it comprises: A control module, used for generating an initial control signal to control the torque processing module to generate a first DC signal and a second DC signal; A self-balancing module is used to judge the first DC signal and the second DC signal: When the amplitudes of the first DC signal and the second DC signal are different, adjusting the torque sensor to adjust the first DC signal and / or the second DC signal until the amplitudes of the first DC signal and the second DC signal are the same; A signal processing module is used to process the first DC signal and the second DC signal to obtain a torque signal.

10. The device according to claim 9, characterized in that The device further includes: an excitation signal generating module, configured to receive the initial control signal and generate the first excitation signal and the second excitation signal; wherein the initial control signal includes: An initial adjustable signal, used to generate a first excitation signal; A first initial excitation signal, used to generate a second excitation signal; The first excitation signal and the second excitation signal have the same amplitude, frequency and phase.

11. The device according to claim 10, characterized in that The initial adjustable signal is a pulse width modulation signal with an adjustable signal duty cycle, and the signal duty cycle is adjusted by the control module to adjust the amplitude of the initial adjustable signal.

12. The device according to claim 11, characterized in that The excitation signal generating module comprises: A low-pass filter, used for filtering the AC signal component in the initial adjustable signal; an operational amplifier for amplifying the filtered initial adjustable signal and acting as a voltage follower to output the second excitation signal having the same amplitude as the first initial excitation signal; The analog switch is used to receive the amplified initial adjustable signal to generate the first excitation signal.

13. The device according to claim 9, characterized in that The device further includes: a potentiometer; wherein the adjusting the torque sensor includes adjusting the resistance of a circuit generating the first DC signal and / or the second DC signal by the potentiometer.

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