Rotating body detection circuit and rotating body

Abstract

The application discloses a rotating body detection circuit and a rotating body, and the rotating body detection circuit comprises: an excitation circuit, which is used for outputting an excitation signal; a magneto-resistive rotary transformer, which is connected with the excitation circuit, and is used for detecting angle information of a rotating body under the excitation of the excitation signal and outputting a plurality of corresponding recovery signals; a recovery circuit, which is used for receiving the recovery signals and performing signal processing and outputting; and / or a direct current (DC) isolation circuit, which is connected in series between the excitation circuit and the magneto-resistive rotary transformer, so as to isolate and process a DC component in the excitation signal; and / or the DC isolation circuit is connected in series between the magneto-resistive rotary transformer and the recovery circuit, so as to isolate and process a DC component in each of the plurality of recovery signals, respectively.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of detection, in particular to a rotating body detection circuit and a rotating body. BACKGROUND

[0002] In recent years, buses, logistics and passenger cars with electric motors as power sources have developed rapidly, and the market prospect is bright. As a low-cost and high-reliability sensor, the magnetic resistance resolver is increasingly widely used in the electric vehicle industry. Especially today, the electric vehicle industry requires high efficiency and energy saving for the range requirement, and the vehicle body requires smooth and comfortable driving, which indirectly requires higher and higher accuracy for the angle detection of the magnetic resistance resolver. In the magnetic resistance resolver, the magnetic resistance resolver includes a stator and a rotor, the stator includes a stator yoke and a stator detection tooth on the stator yoke; the rotor has a rotor salient pole. The materials of the stator yoke, the stator detection tooth and the rotor salient pole are all magnetic conductive materials. The magnetic resistance resolver further includes a plurality of coils, each coil is wound on the stator detection tooth, and the inductance of each coil changes with the change of the rotation angle of the rotor, so as to detect the rotation angle and / or position of the rotor. Each coil can form a 4-column parallel multi-bridge arm bridge circuit, each column of bridge arms can include two bridge arms, and each bridge arm includes at least one coil. In the multi-bridge arm bridge circuit, the upper and lower bridge arms of each column of bridge arms each include at least one coil; two parallel connection points of the multi-bridge arm bridge circuit lead out two lead-out lines as excitation lines, and one lead-out line is led out from the connection points of the upper and lower bridge arms of each column of bridge arms as a signal line, generating four single-ended recycling signals, which contain the angle information of the rotor, and the differential signals are decoded by a decoding chip, so as to obtain the current rotor position and speed information. Fig. 1 The topology of the new magnetic resistance resolver. Among them, the two lead terminals of the excitation coil, that is, the positive terminal of the excitation coil and the negative terminal of the excitation coil are connected to the positive and negative input terminals of the excitation signal, and the four lead terminals S1, S2, S3 and S4 composed of the sine output winding and the cosine output winding are used as the output terminals of the bridge voltage division. The differential signals output by the two signal lead terminals (lead terminals S1, S3) generate an alternating current signal that changes with the rotation angle of the rotor, and the differential signals output by the other two signal lines (lead terminals S2, S4) generate another alternating current signal that changes with the rotation angle of the rotor. The phase difference between the two alternating current signals is analyzed to detect the rotation angle of the rotor. However, the existing magnetic resistance resolver is easily disturbed by its own signal, which affects the detection accuracy, and in severe cases, the rotation angle of the rotor cannot be measured normally. SUMMARY

[0003] The main purpose of the present application is to provide a rotating body detection circuit and a rotating body, which aims to improve the detection accuracy and reliability of the resolver excitation signal processing circuit.

[0004] To achieve the above object, the application provides a rotating body detection circuit, which comprises:

[0005] An excitation circuit is used for outputting an excitation signal;

[0006] A magneto-resistive resolver is connected with the excitation circuit, and is used for detecting angle information of a rotating object under the excitation of the excitation signal and outputting a plurality of corresponding recovery signals;

[0007] A recovery circuit is used for receiving the recovery signals and performing signal processing and outputting;

[0008] A direct current (DC) isolation circuit is arranged in series between the excitation circuit and the magneto-resistive resolver, so as to isolate and process the DC component in the excitation signal; and / or,

[0009] The DC isolation circuit is arranged in series between the magneto-resistive resolver and the recovery circuit, so as to isolate and process the DC component in each of the plurality of recovery signals.

[0010] Optionally, when the DC isolation circuit is arranged in series between the excitation circuit and the magneto-resistive resolver, the DC isolation circuit comprises a coupling device, which is used for coupling the alternating current (AC) component in the excitation signal output by the excitation circuit to the magneto-resistive resolver, so as to isolate and process the DC component in the excitation signal.

[0011] Optionally, the coupling device comprises a first capacitor and a second capacitor, the first capacitor is arranged in series between the positive output end of the excitation circuit and the positive end of the excitation coil of the magneto-resistive resolver;

[0012] The second capacitor is arranged in series between the negative output end of the excitation circuit and the negative end of the excitation coil of the magneto-resistive resolver.

[0013] Optionally, the first capacitor and the second capacitor are integrated in the excitation circuit, and the first capacitor and the second capacitor are electrically connected with the magneto-resistive resolver through a cable.

[0014] Optionally, the coupling device comprises a transformer, the primary coil of the transformer is connected with the excitation circuit, and the secondary coil of the transformer is connected with the magneto-resistive resolver.

[0015] Optionally, the magneto-resistive resolver comprises a plurality of recovery signal output ends;

[0016] When the DC blocking circuit is arranged in series between the magnetic resistance type rotary transformer and the recovery circuit, the DC blocking circuit comprises a plurality of operational amplifier DC blocking units, a first input end of each of the operational amplifier DC blocking units is connected with the recovery signal output end, a second input end of each of the operational amplifier DC blocking units is used for accessing a direct current signal, and an output end of each of the operational amplifier DC blocking units is connected with the recovery circuit.

[0017] Optionally, each of the operational amplifier DC blocking units comprises:

[0018] an operational amplifier, a first resistor, a second resistor, a third resistor and a fourth resistor, a non-inverting input end of the operational amplifier is connected with the recovery signal output end through the first resistor, an inverting input end of the operational amplifier accesses the direct current signal through the third resistor; the second resistor is arranged in series between the first resistor and the ground; and the fourth resistor is arranged in series between the third resistor and the recovery circuit; wherein,

[0019] The resistance values of the first resistor, the second resistor, the third resistor and the fourth resistor are adjustable.

[0020] Optionally, the excitation circuit comprises:

[0021] a signal processing circuit, an input end of the signal processing circuit is used for accessing the excitation signal, and the signal processing circuit is used for amplifying the accessed excitation signal;

[0022] a push-pull amplification circuit, the push-pull amplification circuit is arranged in series between the excitation circuit and the magnetic resistance type rotary transformer.

[0023] Optionally, an adjustable resistor is arranged in series between an input end and an output end of the push-pull amplification circuit, and the adjustable resistor is used for adjusting the amplitude of the excitation signal.

[0024] Optionally, the rotary body detection circuit further comprises:

[0025] a processor, an output end of the processor is connected with the excitation circuit, and an input end of the processor is connected with the recovery circuit.

[0026] The application further provides a rotary body, which comprises a rotary body body and the rotary body detection circuit.

[0027] The rotation angle of the magnetic resistance type rotary transformer in the rotary body detection circuit changes with the rotation of the rotary body body, so as to detect the angle and / or position of the rotary body.

[0028] The application can effectively solve the DC bias problem of the new type of reluctance resolver caused by the electrical structure by setting a DC isolation circuit in series in the detection circuit formed by the excitation circuit, the reluctance resolver and the recovery circuit, and can control the amplitude of the recovery signal in a reasonable range, and ensure the normal work of the decoding chip in the later stage of the recovery circuit. At the same time, the setting of the DC isolation circuit, the reluctance resolver can be applied to the rotation angle measuring device, and can also be used for the case that the position sensor is the reluctance resolver. The added DC isolation circuit has no effect on the recovery signal, and the compatible application of different position sensors can be achieved. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the drawings shown.

[0030] Fig. 1 The circuit structure schematic diagram of an embodiment of the rotating body detection circuit of the present application is shown in the figure.

[0031] Fig. 2 The circuit structure schematic diagram of another embodiment of the rotating body detection circuit of the present application is shown in the figure.

[0032] Fig. 3 The circuit structure schematic diagram of the DC isolation circuit and the reluctance resolver in an embodiment is shown in the figure. Fig. 1

[0033] The circuit structure schematic diagram of the DC isolation circuit and the reluctance resolver in another embodiment is shown in the figure. Fig. 4 Fig. 1 The circuit structure schematic diagram of the DC isolation circuit in an embodiment is shown in the figure.

[0034] Fig. 5 Fig. 2 The circuit structure schematic diagram of the reluctance resolver in an embodiment is shown in the figure.

[0035] Fig. 6 The simplified schematic diagram of the excitation circuit is shown in the figure. Fig. 1

[0036] The simplified schematic diagram of the excitation circuit is shown in the figure. Fig. 7 Fig. 1 The decoding structure schematic diagram of the inductive resolver is shown in the figure.

[0037] Fig. 8 The decoding structure schematic diagram of the inductive resolver is shown in the figure.

[0038] BRIEF DESCRIPTION OF DRAWINGS:​​​

[0039] Reference Name Reference Name 10 Excitation circuit C1 First capacitor 20 Magnetic resistance type rotary transformer C2 Second capacitor 30 Recovery circuit T1 Transformer 40 Direct current blocking circuit U1 Operational amplifier 41 Operational amplifier direct current blocking unit R1-R4 First resistor to fourth resistor 50 Processor

[0040] The objectives, features and advantages of the present application will be further illustrated in conjunction with the embodiments, with reference to the accompanying drawings. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be apparently and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0042] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly.

[0043] In addition, if the embodiments of the present application involve descriptions of “first”, “second”, etc., the descriptions of “first”, “second”, etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by “first”, “second” can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person skilled in the art can realize the combination, and when the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist, and is also not within the protection scope of the present application.

[0044] The term “and / or” in this paper is only a description of the association relationship between the associated objects, which means that there can be three relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone. In addition, the character “ / ” in this paper generally represents that the front and rear associated objects have an “or” relationship.

[0045] The present application provides a rotating body detection circuit.

[0046] Reference Fig. 1 to Fig. 8 In an embodiment of the present application, the rotating body detection circuit comprises:

[0047] The excitation circuit 10 is configured to output an excitation signal.

[0048] A magnetic reluctance resolver 20 is connected to the excitation circuit 10, and is configured to detect angle information of a rotating object under excitation of the excitation signal and output a plurality of corresponding recovery signals.

[0049] A recovery circuit 30 is configured to receive the recovery signals and perform signal processing and output.

[0050] A direct current isolation circuit 40 is connected in series between the excitation circuit 10 and the magnetic reluctance resolver 20, and is configured to isolate direct current components in the excitation signal; and / or,

[0051] The direct current isolation circuit 40 is connected in series between the magnetic reluctance resolver 20 and the recovery circuit 30, and is configured to isolate direct current components in each of the plurality of recovery signals.

[0052] In the embodiment, the excitation circuit 10, the magnetic reluctance resolver 20, and the recovery circuit 30 are connected in series, and form a detection signal flow path, and the direct current isolation circuit 40 can be connected in series at any position of the detection circuit. That is, the direct current isolation circuit 40 can be connected in series between the excitation circuit 10 and the magnetic reluctance resolver 20, or can be connected in series between the recovery circuit 30 and the magnetic reluctance resolver 20, or one direct current isolation circuit 40 can be connected in series between the excitation circuit 10 and the magnetic reluctance resolver 20, and another direct current isolation circuit 40 can be connected in series between the recovery circuit 30 and the magnetic reluctance resolver 20.

[0053] When the rotating body detection circuit is in operation, the excitation circuit 10 receives an excitation signal output by a decoding chip of the magnetic reluctance resolver 20, amplifies the excitation signal, and sends the amplified excitation signal to the magnetic reluctance resolver 20. The magnetic reluctance resolver 20 has an excitation coil winding and two resolver output coil windings. When the resolver excitation coil winding receives the excitation signal and is excited by an alternating voltage at a certain frequency, the voltage amplitude of the resolver output winding has a sine and cosine function relationship with the rotor angle. The resolver output is two differential signals containing angle information, i.e., recovery signals. The recovery circuit 30 is configured to receive the recovery signals containing angle information of the rotating body measured and returned by the magnetic reluctance resolver 20, and input the recovery signals to a processor 50. The recovery circuit 30 can specifically perform signal processing such as sampling, signal amplification, and filtering on the recovery signals, and output the processed recovery signals to the processor 50. The processor 50 decodes the recovery signals and obtains angle information of the rotating body, and obtains position and speed information of the rotating body based on the angle information, thereby achieving measurement of the shaft angular displacement and angular velocity of the rotating object.

[0054] It is understandable that a rotary transformer can be designed as an inductive rotary transformer and a reluctance rotary transformer 20. A schematic diagram of an inductive rotary transformer for decoding angular position and velocity signals is shown below. Fig. 8 As shown in the diagram, the inductive rotary transformer includes a stator and a rotor. The stator has an excitation coil wound on it, serving as the primary side of transformer T1 and receiving the excitation voltage (i.e., the excitation signal). The rotor has two output windings wound on it, serving as the secondary side of transformer T1, which generate induced voltages through electromagnetic coupling. The sinusoidal recovery signals output by the two output windings are 90° out of phase. Since the inductive rotary transformer itself has DC blocking capabilities, the DC component carried by the excitation will not be transmitted to the secondary side of transformer T1. Therefore, no additional DC blocking device is needed. By configuring pull-up resistors on the recovery signal path, i.e., on the secondary side of transformer T1, the DC component of the recovery signal can be adjusted to the value required for decoding. Specifically, the bias voltage of the recovery signal can be adjusted to the midpoint of the input range of the decoding chip.

[0055] For the excitation circuit 10, its power supply is generally a single power source, and the input of the reluctance resolver requires an AC signal of a certain frequency. Therefore, the excitation signals R1 and R2 are generally AC signals with opposite phases and superimposed with the same DC component. By controlling the amplitudes of the excitation signals R1 and R2, the required differential excitation can be generated, which can greatly reduce the influence of external interference during signal transmission in applications with long signal lines. Fig. 6 As shown, Fig. 6 A schematic diagram of the circuit structure of a novel reluctance rotary transformer is shown. The single-ended recovery signals S1, S2, S3, and S4 are all obtained by excitation voltage division. Since both the positive and negative excitation signals contain the same DC component, S1, S2, S3, and S4 also have the same DC component. Because the reluctance rotary transformer 20 adopts a bridge configuration, there is no electrical isolation. The applied excitation signal generally contains a DC component, and the recovered differential signal will also contain a DC component. In practical applications, the amplitude requirement for the excitation signal is generally 7V rms or 5V rms, and the DC bias generally exceeds 5V, which is greater than the input range of a typical decoding chip. For decoding chips, the input signal is generally required to be within a certain range. This DC component will cause the recovered signal to exceed the input range of the decoding chip, resulting in signal distortion and reduced decoding accuracy, or even malfunction and loss of decoding function. Therefore, DC blocking is required. Based on this, the present invention provides a DC blocking circuit 40, which can block the excitation signal output to the reluctance rotary transformer 20, or block the single-ended recovery signal of each output channel of the reluctance rotary transformer 20.

[0056] The application can effectively solve the DC bias problem of the new type of reluctance resolver caused by the electrical structure, control the amplitude of the recovery signal in a reasonable range, and ensure the normal operation of the decoding chip in the later stage of the recovery circuit 30.

[0057] With reference to Fig. 3 and Fig. 4 In an embodiment, when the DC isolation circuit 40 is arranged in series between the excitation circuit 10 and the reluctance resolver 20, the DC isolation circuit 40 comprises a coupling device for coupling the AC component in the excitation signal output by the excitation circuit 10 to the reluctance resolver 20 to isolate the DC component in the excitation signal.

[0058] In the embodiment, the excitation signal output by the excitation circuit 10 is coupled to the reluctance resolver 20 by using the AC isolation characteristic of the coupling device. At this time, only the AC component in the excitation signal is coupled to the reluctance resolver 20, and the DC component in the excitation signal is isolated on the excitation circuit 10 side, thereby solving the DC bias problem of the reluctance resolver caused by the electrical structure.

[0059] With reference to Fig. 3 In an embodiment, the coupling device comprises a first capacitor C1 and a second capacitor C2. The first capacitor C1 is arranged in series between the positive output end of the excitation circuit 10 and the positive end Rp1 of the excitation coil of the reluctance resolver 20.

[0060] The second capacitor C2 is arranged in series between the negative output end of the excitation circuit 10 and the negative end Rp2 of the excitation coil of the reluctance resolver 20.

[0061] In the embodiment, the first capacitor C1 is arranged in series on the positive loop of the excitation circuit 10 and the resolver T1 to access the positive excitation signal output by the excitation circuit 10 and couple the positive excitation signal to the reluctance resolver 20. The second capacitor C2 is arranged in series on the negative loop of the excitation circuit 10 and the resolver T1 to access the negative excitation signal output by the excitation circuit 10 and couple the negative excitation signal to the reluctance resolver 20, thereby achieving excitation of the reluctance resolver 20. As shown in Fig. 5 Fig. 5 ​The schematic diagram for realizing the isolation of the DC component in the excitation signal by using the capacitive DC isolation scheme. The capacitor has the effect of blocking the DC component, so the capacitive DC isolation is adopted, and the excitation signal is suitable for both the decoding chip output and the push-pull amplification circuit output. It can be understood that the modeling simulation is performed on the resolver model, and the actual measurement is performed. The larger the capacitance value of the capacitor is selected, the better the DC isolation effect is; the smaller the capacitance value is, the smaller the influence on the phase and amplitude of the excitation is. In combination with the resolver parameters and the excitation amplitude, frequency, etc., the capacitor with a capacitance value of 1-50 uF can be selected to realize the DC isolation.

[0062] It can be understood that when the rotating body detection circuit is applied to the motor controller, the excitation circuit 10 and the recovery circuit 30 are usually arranged on the electric control board of the motor controller, the resolver 20 is arranged on the motor as a component of the motor, and the resolver 20 and the excitation circuit 10 and the resolver 20 and the recovery circuit 30 are usually connected through a cable. In order to avoid the signal backflow between the resolver 20 and the excitation circuit 10, which affects the short circuit phenomenon of the excitation circuit 10, such as short circuit to ground or short circuit to power supply, a capacitor is usually arranged in the excitation circuit 10, and the capacitor is arranged in series between the excitation circuit 10 and the signal of the resolver 20 to isolate the signal of the resolver 20. For this purpose, the first capacitor C1 and the second capacitor C2 in the coupling device of the embodiment can reuse the capacitor in the excitation circuit 10, and the capacitor in the excitation circuit 10 is used to block the DC component output from the excitation circuit 10 to the resolver 20, and also can realize the isolation of the signal backflow from the resolver 20 to the excitation circuit 10. In this way, without increasing the rotating body detection circuit, the DC isolation effect can be achieved, and the DC bias problem caused by the electrical structure of the new reluctance resolver can be effectively solved, the amplitude of the recovered signal is controlled within a reasonable range, and the normal work of the decoding chip in the later stage of the recovery circuit 30 is ensured.

[0063] Reference Fig. 4 In an embodiment, the coupling device includes a transformer T1, a primary winding of the transformer T1 is connected with the excitation circuit 10, and a secondary winding of the transformer T1 is connected with the reluctance resolver 20.

[0064] In the embodiment, two lead terminals of the primary winding of the transformer T1 are connected with a positive terminal and a negative terminal of the excitation circuit 10 respectively, so as to access the positive excitation signal and the negative excitation signal output from the excitation circuit 10, and couple the positive excitation signal and the negative excitation signal to the reluctance resolver 20, to realize the excitation of the reluctance resolver 20. Fig. 6The transformer T1 is used to isolate the DC component in the excitation signal. The transformer T1 has the effect of blocking the DC component. The DC component in the excitation signal can be removed through the coupling between the primary and secondary sides of the transformer T1, so that the recovered signal is single-ended and can be configured according to the acceptable input of the decoding chip.

[0065] Referring to Fig. 5 In an embodiment, the magnetic rotor 20 includes a plurality of recovered signal output terminals;

[0066] When the DC isolation circuit 40 is arranged in series between the magnetic rotor 20 and the recovery circuit 30, the DC isolation circuit 40 includes a plurality of operational amplifier DC isolation units 41. The first input terminal of each operational amplifier DC isolation unit 41 is connected to a recovered signal output terminal. The second input terminal of each operational amplifier DC isolation unit 41 is used to input a DC signal Vdc. The output terminal S1' of each operational amplifier DC isolation unit 41 is connected to the recovery circuit 30.

[0067] In this embodiment, the number of recovered signal output terminals is four, which are S1, S2, S3, and S4. Four operational amplifier DC isolation units 41 are arranged in this embodiment. The operational amplifier DC isolation unit 41 can be built into a subtractor. One input terminal of the subtractor is connected to a recovered signal, and the other input terminal of the subtractor is connected to a DC signal Vdc. The amplitude of the DC signal Vdc can be adapted to the size of the DC component in the excitation signal output by the excitation circuit 10. The DC component is removed from the single-ended signal output by the recovered signal output terminal through the difference calculation of the recovered signal and the DC component, so that the single-ended DC component can be eliminated.

[0068] Referring to Fig. 5 In an embodiment, each operational amplifier DC isolation unit 41 includes:

[0069] An operational amplifier U1, a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4. The non-inverting input terminal of the operational amplifier U1 is connected to the recovered signal output terminal S1 through the first resistor R1. The inverting input terminal of the operational amplifier U1 is connected to the DC signal Vdc through the third resistor R3. The second resistor R2 is arranged in series between the first resistor R1 and the ground. The fourth resistor R4 is arranged in series between the third resistor R3 and the recovery circuit 30. Wherein,

[0070] The resistance values of the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4 can be adjusted. As Fig. 5 shown, Fig. 5The shown is an operational amplifier direct current isolation scheme diagram, the processing scheme of S1 signal is given in the figure, and the rest S2, S3, S4 are the same as this. This scheme needs to reasonably configure the amplitude of Vdc according to the size of the recovered signal direct current bias, and eliminate the direct current bias by difference. The first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4 can be realized by adjustable resistor or other electronic components.

[0071] It should be noted that in the excitation circuit 10, different decoding chips can be configured to select whether to set the push-pull amplifier circuit. In the embodiment of the excitation signal generated by the push-pull amplifier circuit, if the single-sided excitation scheme is adopted (the negative of the excitation signal is the signal ground), in addition to the problem of direct current component, attention should also be paid to the problem of recovered signal amplitude. Because the single-sided excitation is adopted, the excitation alternating current component in the recovered signal cannot be cancelled as in the double-sided excitation, so the alternating current component of the recovered signal is too large, which may exceed the threshold value supported by the decoding chip and cause decoding failure. Therefore, the amplitude can be adjusted by appropriately adjusting the excitation signal amplitude (specifically, the resistance value of the push-pull amplifier circuit can be changed to achieve this) or by the subtractor circuit built by the operational amplifier for eliminating direct current bias, that is, the operational amplifier direct current isolation unit 41 of the present application. Specifically, the resistance values of resistors R1, R2, R3 and R4 in the operational amplifier direct current isolation unit 41 can be changed, for example, the resistance value ratio of resistors R1 and R2 can be changed to adjust the voltage division ratio of the signal amplitude input to the non-inverting input terminal of the operational amplifier U1, and then the recovered signal amplitude is adjusted. Alternatively, the resistance value ratio of resistors R3 and R4 can be changed to adjust the voltage division ratio of the signal amplitude input to the inverting input terminal of the operational amplifier U1, and then the recovered signal amplitude is adjusted. In this way, the recovered signal amplitude can be adjusted to eliminate the excitation component in the recovered signal to reduce the amplitude of each single-ended recovered signal, so as to meet the input range requirement of the processor 50.

[0072] Reference Fig. 1 to Fig. 8 In an embodiment, the excitation circuit 10 comprises:

[0073] The signal processing circuit is connected to the input of the excitation signal, and the signal processing circuit is used for amplifying the input excitation signal.

[0074] The push-pull amplifier circuit is connected in series between the excitation circuit 10 and the magnetic resistance type rotary transformer 20.

[0075] In this embodiment, reference Fig. 7 , Fig. 7 The simplified schematic diagram of the excitation circuit is shown, and the excitation circuit 10 generally has two forms according to the configuration of the decoding chip: containing a push-pull amplifier circuit and not containing a push-pull amplifier circuit, and the schematic diagrams of the two excitation circuits 10 are as follows Fig. 3The excitation circuit 10 provided with the push-pull amplification circuit can be used in combination with MCU self-decoding application and AD2S1205 decoding chip application (the decoding chip cannot output the excitation signal available for the position sensor), and the excitation circuit 10 without the push-pull amplification circuit can be used in combination with PGA411 decoding chip application (the decoding chip can directly output the available excitation). The excitation circuit 10 in the embodiment is provided with the push-pull amplification circuit, and the excitation circuit 10 in the embodiment further comprises a signal processing circuit. The signal processing circuit can amplify the signal output by the decoding chip and convert the signal into a suitable voltage value for the magneto-resistive resolver 20. The push-pull amplification circuit can improve the drive current of the excitation signal.

[0076] The adjustable resistor is connected in series between the input end and the output end of the push-pull amplification circuit, and is used for adjusting the amplitude of the excitation signal. In the embodiment, the amplitude of the recovered signal output by the magneto-resistive resolver 20 can be adjusted by appropriately adjusting the amplitude of the excitation signal (by changing the resistance value of the push-pull amplification circuit), so as to reduce the amplitude of the excitation signal, and accordingly reduce the recovered signal, thereby achieving the effect of reducing the amplitude of each single-ended recovered signal, so as to meet the input range requirement of the processor 50.

[0077] The direct current bias problem of the new magneto-resistive resolver caused by the electrical structure can be effectively solved by the direct current blocking circuit 40 for the excitation signal in the above embodiments, the amplitude of the recovered signal is controlled within a reasonable range, and the normal work of the decoding chip is ensured. Meanwhile, the application can achieve compatible application of different position sensors.

[0078] Referring to Fig. 1 and Fig. 2 In an embodiment, the rotating body detection circuit further comprises:

[0079] A processor 50, an output end of the processor 50 is connected with the excitation circuit 10, and an input end of the processor 50 is connected with the recovery circuit 30.

[0080] In the embodiment, the processor 50 can be a special decoding chip or a microprocessor with decoding function. The decoding chip is electrically connected with the excitation circuit 10 and the recovery circuit 30, and is used for outputting an excitation signal to the excitation circuit 10, so that the excitation circuit 10 can provide an excitation signal to the magneto-resistive rotary transformer 20. The output excitation signal is a sinusoidal excitation signal. When the processor 50 is a special decoding chip, the decoding chip analyzes the recovery signal received by the recovery circuit 30 to obtain an angle signal, converts the angle signal into serial data, parallel data or pulse signal, and then outputs the angle signal to a main control chip of a rotary body controller, such as a motor controller, so that the main control chip of the rotary body controller can calculate the rotation speed and position of the rotary body. In this way, the controller can detect the position of the rotary body in real time, and can also detect the rotation speed and the absolute angle of the rotary body after rotating multiple rounds, so as to realize high-precision control of the torque, speed and position of the driving mechanism of the rotary body. When the processor 50 is a microprocessor with decoding function, the microprocessor 50 can be a main controller of a rotary body controller. The microprocessor 50 analyzes the recovery signal received by the recovery circuit 30 to obtain an angle signal, so as to calculate the rotation speed and position of the rotary body. In this way, the microprocessor 50 can detect the position of the rotary body in real time, and can also detect the rotation speed and the absolute angle of the rotary body after rotating multiple rounds, so as to realize high-precision control of the torque, speed and position of the driving mechanism of the rotary body. In the embodiment, the output end of the excitation circuit 10 can also be connected with the processor 50, so that the processor 50 can realize the read-back of the excitation signal.

[0081] The application further provides a rotary body, which comprises a rotary body body and the rotary body detection circuit.

[0082] The rotary angle of the magneto-resistive rotary transformer in the rotary body detection circuit changes with the rotation of the rotary body body, so as to detect the angle and / or position of the rotary body.

[0083] The detailed structure of the rotary body detection circuit can refer to the above-mentioned embodiments, which will not be described here again. It can be understood that, since the above-mentioned rotary body detection circuit is used in the rotary body of the application, the embodiments of the rotary body of the application include all the technical solutions of all the embodiments of the rotary body detection circuit, and the technical effects achieved are also completely the same, which will not be described here again.

[0084] In the embodiment, the rotary body body can be a motor, and the magneto-resistive rotary transformer in the rotary body detection circuit can be arranged on the rotating shaft of the motor. The magneto-resistive rotary transformer is connected with the rotating shaft of the motor by a shaft coupling and rotates synchronously with the rotating shaft of the motor. The rotary body in the embodiment can be used in the field of electric bicycles, electric motorcycles, electric forklifts and the like which use the magneto-resistive rotary transformer to feed back the motor position signal.

[0085] The above merely describes optional embodiments of the present application, and does not limit the patent scope of the present application, and any equivalent structural transformation made under the inventive concept of the present application, or direct / indirect application in other related technical fields, is included in the patent protection scope of the present application.

Claims

1. A rotating body detection circuit, characterized in that, The rotating body detection circuit includes: Excitation circuit, used to output excitation signal; A magnetoresistive rotary transformer is connected to the excitation circuit. The magnetoresistive rotary transformer is used to detect the angle information of the rotating object under the excitation signal and output multiple corresponding recovery signals. A recycling circuit is used to receive the recycling signal and perform signal processing and output; A DC blocking circuit is connected in series between the excitation circuit and the reluctance rotary transformer to isolate the DC component in the excitation signal. The DC blocking circuit reuses some of the components of the excitation circuit; The rotating body detection circuit also includes: The processor has its output terminal connected to the excitation circuit and its input terminal connected to the recycling circuit, and is used to output an excitation signal. The output of the excitation circuit is connected to the processor so that the processor can read back the excitation signal.

2. The rotating body detection circuit as described in claim 1, characterized in that, When the DC blocking circuit is connected in series between the excitation circuit and the reluctance rotary transformer, the DC blocking circuit includes a coupling device. The coupling device is used to couple the AC component of the excitation signal output by the excitation circuit to the reluctance rotary transformer to isolate the DC component of the excitation signal.

3. The rotating body detection circuit as described in claim 2, characterized in that, The coupling device includes a first capacitor and a second capacitor, wherein the first capacitor is connected in series between the positive output terminal of the excitation circuit and the positive terminal of the excitation coil of the reluctance rotary transformer. The second capacitor is connected in series between the negative output terminal of the excitation circuit and the negative terminal of the excitation coil of the reluctance rotary transformer.

4. The rotating body detection circuit as described in claim 3, characterized in that, The first capacitor and the second capacitor are integrated in the excitation circuit, and the first capacitor and the second capacitor are electrically connected to the magnetoresistive rotary transformer via a cable.

5. The rotating body detection circuit as described in claim 2, characterized in that, The coupling device includes a transformer, the primary winding of which is connected to the excitation circuit, and the secondary winding of which is connected to the reluctance rotary transformer.

6. The rotating body detection circuit as described in claim 1, characterized in that, The excitation circuit includes: A signal processing circuit, the input terminal of which is used to receive the excitation signal, and the signal processing circuit is used to amplify the received excitation signal; A push-pull amplifier circuit is connected in series between the excitation circuit and the magnetoresistive rotary transformer.

7. The rotating body detection circuit as described in claim 6, characterized in that, An adjustable resistor is connected in series between the input and output terminals of the push-pull amplifier circuit. The adjustable resistor is used to adjust the amplitude of the excitation signal.

8. A rotating body, characterized in that, The rotating body includes a rotating body body and a rotating body detection circuit as described in any one of claims 1-7; The rotation angle of the magnetoresistive rotary transformer in the rotating body detection circuit follows the rotation change of the rotating body to detect the angle and / or position of the rotating body.

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