Rotary transformer signal stability judgment circuit, rotary transformer circuit system and vehicle

Abstract

The invention discloses a rotary transformer signal stability judgment circuit, a rotary transformer circuit system and a vehicle. The rotary transformer signal stability judgment circuit comprises a sinusoidal signal processing branch, a cosine signal processing branch, an adder circuit, a low-pass filter circuit and a comparator circuit, wherein the sine signal processing branch and the cosine signal processing branch are respectively connected with the adder circuit, and the adder circuit, the low-pass filter circuit and the comparator circuit are connected in sequence. The rotary transformer signal stability judgment circuit can detect whether the output signals of the two return winding ends of the rotary transformer are in an effective signal amplitude range in real time, so that no calculation power is occupied; according to the method, the problems of various broken lines or abnormal angle output and the like possibly occurring in the use process of the rotary transformer can be effectively detected in time and accurately, the method is easy to implement, low in cost and good in real-time performance, and the load of a calculation chip in a circuit system of the rotary transformer can be effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of signal processing, and in particular to a resolver signal stability judgment circuit, a resolver circuit system and a vehicle. Background Art

[0002] A resolver (also referred to as a resolver) is a sensor whose output voltage changes with the rotor angle. It is usually composed of an excitation winding and a two-phase orthogonal return winding. Figure 1 As shown, when a high-frequency excitation reference signal is passed through the excitation winding end, each return winding end will induce a sine output signal and a cosine output signal. By decoding these two output signals, the rotor angle can be obtained.

[0003] Since the resolver may encounter problems such as wire breakage or abnormal angle output during use, it is particularly important to monitor the normality of the resolver's output signal. In order to ensure that the resolver's output signal remains stable and reliable during operation, an effective monitoring mechanism is required. Summary of the invention

[0004] The embodiments of the present invention provide a resolver signal stability judgment circuit, a resolver circuit system and a vehicle. By implementing a resolver output signal stability judgment circuit based on pure analog devices, the monitoring complexity can be effectively reduced while ensuring the real-time monitoring.

[0005] According to one aspect of an embodiment of the present invention, a resolver signal stability judgment circuit is provided, comprising: a sine signal processing branch, a cosine signal processing branch, an adder circuit, a low-pass filter circuit and a comparator circuit;

[0006] The sine signal processing branch and the cosine signal processing branch are respectively connected to the adder circuit, and the adder circuit, the low-pass filter circuit and the comparator circuit are connected in sequence;

[0007] A sinusoidal signal processing branch, used for collecting a sinusoidal output signal from a first return winding end of the rotary transformer, and performing a square operation on the sinusoidal output signal to obtain a first processed signal;

[0008] A cosine signal processing branch, used for collecting a cosine output signal from a second return winding end of the rotary transformer, and performing a square operation on the cosine output signal to obtain a second processed signal;

[0009] an adder circuit, configured to perform an addition operation on the first processed signal and the second processed signal to obtain a third processed signal;

[0010] A low-pass filter circuit, used for performing low-pass filtering on the third processed signal to obtain a target DC signal;

[0011] The comparator circuit is used to compare the amplitude of the target DC signal with the first comparison level and the second comparison level respectively, and output the two level values ​​obtained after comparison.

[0012] Furthermore, the sinusoidal signal processing branch comprises:

[0013] A first differential amplifier circuit and a first hardware multiplier connected in sequence, wherein an output terminal of the first differential amplifier circuit is respectively connected to two input terminals of the first hardware multiplier;

[0014] The in-phase input terminal and the in-phase input terminal of the first differential amplifier circuit are respectively used to input two sinusoidal output signals of the same frequency and inverted phases, and the output terminal of the first hardware multiplier is used as the output terminal of the sinusoidal signal processing branch.

[0015] Furthermore, the first differential amplifier circuit specifically includes:

[0016] a first resistor, a second resistor, a third resistor, a fourth resistor and a first operational amplifier;

[0017] Among them, the first end of the first resistor is connected to the power supply terminal, the second end of the first resistor is respectively connected to the first end of the second resistor and the non-inverting input terminal of the first operational amplifier, the second end of the second resistor is connected to the ground terminal, the first end of the third resistor is connected to the power supply terminal, the second end of the third resistor is respectively connected to the first end of the fourth resistor and the inverting input terminal of the first operational amplifier, and the second end of the fourth resistor is connected to the output terminal of the first operational amplifier.

[0018] Furthermore, the cosine signal processing branch specifically includes:

[0019] A second differential amplifier circuit and a second hardware multiplier connected in sequence, wherein an output end of the second differential amplifier circuit is respectively connected to two input ends of the second hardware multiplier;

[0020] The in-phase input terminal and the inverting input terminal of the second differential amplifier circuit are respectively used to input two cosine output signals of the same frequency and inverted phases, and the output terminal of the second hardware multiplier is used as the output terminal of the cosine signal processing branch.

[0021] Furthermore, the second differential amplifier circuit specifically includes:

[0022] a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, and a second operational amplifier;

[0023] Among them, the first end of the fifth resistor is connected to the power supply terminal, the second end of the fifth resistor is respectively connected to the first end of the sixth resistor and the in-phase input terminal of the second operational amplifier, the second end of the sixth resistor is connected to the ground terminal, the first end of the seventh resistor is connected to the power supply terminal, the second end of the seventh resistor is respectively connected to the first end of the eighth resistor and the inverting input terminal of the second operational amplifier, and the second end of the eighth resistor is connected to the output terminal of the second operational amplifier.

[0024] Furthermore, the adder circuit specifically comprises:

[0025] a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor and a third operational amplifier;

[0026] Among them, the first end of the ninth resistor is connected to the ground end, the second end of the ninth resistor is respectively connected to the first end of the tenth resistor and the inverting input end of the third operational amplifier, the second end of the tenth resistor is connected to the output end of the third operational amplifier, the first end of the eleventh resistor is connected to the output end of the sine signal processing branch, the second end of the eleventh resistor is connected to the in-phase input end of the third operational amplifier, the first end of the twelfth resistor is connected to the output end of the cosine signal processing branch, the second end of the twelfth resistor is connected to the second end of the eleventh resistor, and the output end of the third operational amplifier is used as the output end of the adder circuit.

[0027] Furthermore, the low-pass filter circuit specifically includes:

[0028] a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a capacitor, and a fourth operational amplifier;

[0029] Among them, the first end of the thirteenth resistor is connected to the output end of the adder circuit, the second end of the thirteenth resistor is respectively connected to the first end of the capacitor, the first end of the fourteenth resistor and the inverting input end of the fourth operational amplifier, the second end of the capacitor is respectively connected to the second end of the fourteenth resistor and the output end of the fourth operational amplifier, the first end of the fifteenth resistor is connected to the ground end, the second end of the fifteenth resistor is connected to the non-inverting input end of the fourth operational amplifier, and the output end of the fourth operational amplifier is used as the output end of the low-pass filter circuit.

[0030] Furthermore, the comparator circuit specifically includes:

[0031] a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a fifth operational amplifier, and a sixth operational amplifier;

[0032] Wherein, the first end of the sixteenth resistor is connected to the output end of the low-pass filter circuit and the first end of the seventeenth resistor respectively, the second end of the sixteenth resistor is connected to the non-inverting input end of the fifth operational amplifier, the second end of the seventeenth resistor is connected to the inverting input end of the sixth operational amplifier, the inverting input end of the fifth operational amplifier is used to input the first comparison level, and the non-inverting input end of the sixth operational amplifier is used to input the second comparison level, the first end of the eighteenth resistor is connected to the power supply end, the second end of the eighteenth resistor is connected to the output end of the fifth operational amplifier, the first end of the nineteenth resistor is connected to the power supply end, and the second end of the nineteenth resistor is connected to the output end of the sixth operational amplifier;

[0033] Among them, the level value outputted by the output end of the fifth operational amplifier is used to measure the comparison result between the target DC signal outputted by the low-pass filter circuit and the first comparison level, and the level value outputted by the output end of the sixth operational amplifier is used to measure the comparison result between the target DC signal outputted by the low-pass filter circuit and the second comparison level.

[0034] According to another aspect of the embodiments of the present invention, there is further provided a resolver circuit system, comprising: a main control circuit, a resolver, and a resolver signal stability judgment circuit as described in any one of the embodiments of the present invention;

[0035] Wherein, the main control circuit is connected to the rotary transformer and the rotary transformer signal stability judgment circuit respectively, and the rotary transformer is connected to the rotary transformer signal stability judgment circuit;

[0036] A main control circuit, used for generating an excitation reference signal and outputting it to an excitation winding end of a rotary transformer;

[0037] The rotary transformer is used to generate a sine output signal and a cosine output signal at two return winding ends respectively under the action of an excitation reference signal, and feed the sine output signal and the cosine output signal back to a main control circuit and a rotary transformer signal stability judgment circuit respectively;

[0038] The resolver signal stability judgment circuit is used to generate two level values ​​according to the received sine output signal and cosine output signal and provide them to the main control circuit;

[0039] The main control circuit is also used to demodulate the rotor angle of the resolver according to the received sine output signal and cosine output signal, and to verify the signal stability of the resolver according to the level value provided by the resolver signal stability judgment circuit.

[0040] According to another aspect of the embodiments of the present invention, a vehicle is further provided, comprising the rotary transformer circuit system as described in any one of the embodiments of the present invention.

[0041] The technical solution of the embodiment of the present invention, by using a sine signal processing branch, a cosine signal processing branch, an adder circuit, a low-pass filter circuit and a comparator circuit built by analog devices, constructs a resolver signal stability judgment circuit in a pure hardware form, which can detect in real time whether the output signals of the two return winding ends of the resolver are within the effective signal amplitude range, so as to achieve the effect of timely and accurate effective detection of various types of broken wires or abnormal angle output problems that may occur during the use of the resolver without occupying any computing power. The implementation is simple, the cost is low, the real-time performance is good, and the load of the computing chip in the resolver circuit system can be effectively reduced.

[0042] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0044] Figure 1 Schematic diagram of the working principle of a rotary transformer applicable to an embodiment of the present invention;

[0045] Figure 2 is a structural diagram of a resolver signal stability judgment circuit provided according to an embodiment of the present invention;

[0046] Figure 3 is a circuit diagram of a first differential amplifier circuit applicable to an embodiment of the present invention;

[0047] Figure 4 is a schematic diagram of implementing a square operation on a single-ended sinusoidal output signal by a first hardware multiplier applicable to an embodiment of the present invention;

[0048] Figure 5 is a circuit diagram of a second differential amplifier circuit applicable to an embodiment of the present invention;

[0049] Figure 6 is a schematic diagram of implementing a square operation on a single-ended cosine output signal by a second hardware multiplier applicable to an embodiment of the present invention;

[0050] Figure 7 is a circuit diagram of an adder circuit applicable to an embodiment of the present invention;

[0051] Figure 8 is a circuit diagram of a low-pass filter circuit applicable to an embodiment of the present invention;

[0052] Fig. 9 is a circuit diagram of a comparator circuit applicable to an embodiment of the present invention;

[0053] Fig.10 A schematic structural diagram of a specific resolver signal stability judgment circuit provided according to an embodiment of the present invention;

[0054] Fig.11 is a structural schematic diagram of a rotary transformer circuit system provided according to an embodiment of the present invention;

[0055] Fig.12 It is a structural schematic diagram of a vehicle provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0056] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0057] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0058] In order to facilitate a deep understanding of the inventive concept of each embodiment of the present invention, the decoding principle of the rotary transformer and the implementation method of the prior art are briefly described.

[0059] Combination Figure 1 As shown in the schematic diagram of the working principle of the rotary transformer, when a voltage of the form: V is applied to the excitation winding end, r (t) = A 0*sin(ωt) as the excitation reference signal, a signal of the form: V Q (t) = K*A 0 *sin(ωt)*sin(θ) sinusoidal output signal, and at the second return winding end can be induced a signal of the form: V I (t) = K*A 0 *sin(ωt)*cos(θ) is the cosine output signal. 0 is the amplitude, ω is the angular velocity of the excitation carrier, K is the ratio of the resolver, and θ is the rotor angle.

[0060] Without considering the influence of various errors and noise factors, the formula can be used: The rotor angle θ is calculated, and then the speed can be obtained by differentiating the rotor angle θ. In the related art, an excitation reference signal can be generated by a main control circuit and provided to a rotary transformer, and the rotor angle of the rotary transformer can be obtained by demodulating the sine output signal and cosine output signal sensed by the two return winding ends of the rotary transformer.

[0061] In the actual use of the resolver, various problems may occur, such as wire breakage or abnormal angle output. In order to effectively detect such problems, it is often necessary to add complex processing logic to the computing chip (typically, CPU) of the main control circuit, which greatly increases the computing load of the computing chip. As a result, the resolver circuit system built based on the above implementation logic cannot effectively cope with fields that require high real-time position control, such as aviation engineering, industrial control or automation.

[0062] Based on the above technical problems, the inventor creatively proposed to judge the stability of the rotary transformer signal (that is, the sinusoidal output signal and cosine output signal induced by the two return winding ends of the rotary transformer) by an independent pure hardware circuit rather than by the main control circuit, so as to effectively reduce the computational load of the computing chip in the main control circuit while ensuring the real-time monitoring.

[0063] Figure 2 A structural diagram of a resolver signal stability judgment circuit provided by an embodiment of the present invention. This embodiment is applicable to the case where the resolver signal stability judgment circuit is used to perform stability detection on the signal amplitude of the sine and cosine output signals collected at the two return winding ends of the resolver. The resolver signal stability judgment circuit is a pure hardware circuit, and each functional module used in the circuit is constructed using pure analog devices.

[0064] Correspondingly, such as Figure 2As shown, the resolver signal stability judgment circuit specifically includes: a sine signal processing branch 210, a cosine signal processing branch 220, an adder circuit 230, a low-pass filter circuit 240 and a comparator circuit 250.

[0065] The sine signal processing branch 210 and the cosine signal processing branch 220 are respectively connected to the adder circuit 230 , and the adder circuit 230 , the low-pass filter circuit 240 and the comparator circuit 250 are connected in sequence.

[0066] The sinusoidal signal processing branch 210 is used to collect the sinusoidal output signal of the first return winding end of the rotary transformer and perform a square operation on the sinusoidal output signal to obtain a first processed signal.

[0067] In general, by performing signal acquisition at the first return winding end of the rotary transformer, two sinusoidal output signals of the same frequency and opposite phase, that is, differential signals, can be obtained. This operation is to improve the anti-interference ability of signal transmission, so that the signal transmission is equivalent, stable and reliable. However, in order to perform subsequent signal processing on the sinusoidal output signal, it is necessary to convert the differential signal into a single-ended signal relative to a set reference point (typically 0V). Therefore, the sinusoidal signal processing branch 210 needs to have a differential to single-ended processing function. At the same time, since it is necessary to square the converted single-ended sinusoidal output signal, the sinusoidal signal processing branch 210 needs to have a power calculation function. Among them, the sinusoidal output signal collected at the first return winding end of the rotary transformer is a voltage signal.

[0068] Accordingly, in an optional implementation of this embodiment, the sinusoidal signal processing branch 210 may include:

[0069] A first differential amplifier circuit and a first hardware multiplier connected in sequence, wherein an output terminal of the first differential amplifier circuit is respectively connected to two input terminals of the first hardware multiplier;

[0070] The in-phase input terminal and the in-phase input terminal of the first differential amplifier circuit are respectively used to input two sinusoidal output signals of the same frequency and inverted phases, and the output terminal of the first hardware multiplier is used as the output terminal of the sinusoidal signal processing branch 210 .

[0071] The first differential amplifier circuit is used to convert the two differential sinusoidal output signals into a single-ended sinusoidal output signal relative to a set reference point. Afterwards, by inputting the two identical single-ended sinusoidal output signals into the first hardware multiplier, a square operation result of the sinusoidal output signal can be obtained, that is, a first processed signal.

[0072] In an optional implementation of this embodiment, as Figure 3As shown, the first differential amplifier circuit may specifically include: a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4 and a first operational amplifier A1.

[0073] Among them, the first end of the first resistor R1 is connected to the power supply end, the second end of the first resistor R1 is respectively connected to the first end of the second resistor R2 and the non-inverting input end of the first operational amplifier A1, the second end of the second resistor R2 is connected to the ground end, the first end of the third resistor R3 is connected to the power supply end, the second end of the third resistor R3 is respectively connected to the first end of the fourth resistor R4 and the inverting input end of the first operational amplifier A1, and the second end of the fourth resistor R4 is connected to the output end of the first operational amplifier A1.

[0074] In this optional implementation, the resistance values ​​of the first resistor R1 , the second resistor R2 , the third resistor R3 and the fourth resistor R4 may be flexibly set according to the actual required amplification factor, and this embodiment does not limit this.

[0075] The in-phase input terminal and the inverting input terminal of the first operational amplifier A1 are used to input two differential sinusoidal output signals, that is, Figure 3 The output terminal of the first operational amplifier A1 is used to output a single-ended sinusoidal output signal Q d .

[0076] Among them, Q d It is the single-ended sinusoidal output signal output by the first differential amplifier circuit, which can be expressed as: Q d =E 0 *sin(ωt)*sin(θ). E 0 The amplitude of the single-ended sinusoidal output signal is determined by the amplification factor set by the first differential amplifier circuit, that is, it can be jointly determined by the resistance values ​​of the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4.

[0077] Furthermore, in this embodiment, the first hardware multiplier used is a pure hardware multiplier device, and the first hardware multiplier is also an analog device. Figure 4 FIG. 4 is a schematic diagram showing a method of using a first hardware multiplier to implement a square operation on an input single-ended sinusoidal output signal. It can be understood that by converting the single-ended sinusoidal output signal Q d are respectively input to the two input terminals of the first hardware multiplier, and the first hardware multiplier can output the single-ended sinusoidal output signal Q d The square signal U q =(Q d ) 2 =(E 0 *sin(ωt)*sin(θ))2 , that is, output the first processed signal U q .

[0078] The cosine signal processing branch 220 is used to collect the cosine output signal of the second return winding end of the rotary transformer and perform a square operation on the cosine output signal to obtain a second processed signal.

[0079] Similar to the processing process of the sine signal processing branch 210, by collecting signals at the second return winding end of the rotary transformer, two cosine output signals with the same frequency and opposite phases can be obtained. Accordingly, the cosine signal processing branch 220 needs to have a differential to single-ended processing function. At the same time, since the converted single-ended cosine output signal needs to be squared, the cosine signal processing branch 220 needs to have a power calculation function. Similarly, the cosine output signal collected at the second return winding end of the rotary transformer is a voltage signal.

[0080] Accordingly, in another optional implementation of the embodiment, the cosine signal processing branch 220 specifically includes:

[0081] A second differential amplifier circuit and a second hardware multiplier connected in sequence, wherein an output end of the second differential amplifier circuit is respectively connected to two input ends of the second hardware multiplier;

[0082] The in-phase input terminal and the in-phase input terminal of the second differential amplifier circuit are respectively used to input two cosine output signals of the same frequency and inverted phases, and the output terminal of the second hardware multiplier is used as the output terminal of the cosine signal processing branch 220 .

[0083] The second differential amplifier circuit is used to convert the two differential cosine output signals into a single-ended cosine output signal relative to a set reference point. Afterwards, by inputting the two identical single-ended cosine output signals into the second hardware multiplier, a square operation result of the cosine output signal can be obtained, that is, a second processed signal.

[0084] In an optional implementation of this embodiment, as Figure 5 As shown, the second differential amplifier circuit may specifically include: a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8 and a second operational amplifier A2;

[0085] Among them, the first end of the fifth resistor R5 is connected to the power supply end, the second end of the fifth resistor R5 is respectively connected to the first end of the sixth resistor R6 and the in-phase input end of the second operational amplifier A2, the second end of the sixth resistor R6 is connected to the ground end, the first end of the seventh resistor R7 is connected to the power supply end, the second end of the seventh resistor R7 is respectively connected to the first end of the eighth resistor R8 and the inverting input end of the second operational amplifier A2, and the second end of the eighth resistor R8 is connected to the output end of the second operational amplifier A2.

[0086] In this optional implementation, the resistance values ​​of the fifth resistor R5, the sixth resistor R6, the seventh resistor R7 and the eighth resistor R8 can be flexibly set according to the actual required amplification factor, and this embodiment does not limit this. However, after the setting is completed, the amplification factors of the first operational amplifier and the second operational amplifier should be consistent.

[0087] The in-phase input terminal and the inverting input terminal of the second operational amplifier A2 are used to input two differential cosine output signals, that is, Figure 5 The output end of the second operational amplifier A2 is used to output a single-ended cosine output signal I d .

[0088] Among them, I d is the single-ended cosine output signal output by the second differential amplifier circuit, which can be expressed as: d =E 0 *sin(ωt)*cos(θ). E 0 The amplitude of the single-ended cosine output signal is determined by the amplification factor set by the second differential amplifier circuit, that is, it can be jointly determined by the resistance values ​​of the fifth resistor R5, the sixth resistor R6, the seventh resistor R7 and the eighth resistor R8.

[0089] Furthermore, in this embodiment, the second hardware multiplier used is a pure hardware multiplier device, and the second hardware multiplier is also an analog device. Figure 6 FIG. 4 is a schematic diagram showing a method of using a second hardware multiplier to implement a square operation on an input single-ended cosine output signal. d are respectively input to the two input terminals of the second hardware multiplier, and the second hardware multiplier can output the single-ended cosine output signal I d The square signal U i =(I d ) 2 =(E 0 *sin(ωt)*cos(θ)) 2 , that is, output the second processed signal U i .

[0090] The adder circuit 230 is used to perform an addition operation on the first processed signal and the second processed signal to obtain a third processed signal.

[0091] In an optional implementation of this embodiment, as Figure 7 As shown, the adder circuit 230 may specifically include:

[0092] a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12 and a third operational amplifier A3;

[0093] Among them, the first end of the ninth resistor R9 is connected to the ground end, the second end of the ninth resistor R9 is respectively connected to the first end of the tenth resistor R10 and the inverting input end of the third operational amplifier A3, the second end of the tenth resistor R10 is connected to the output end of the third operational amplifier A3, the first end of the eleventh resistor R11 is connected to the output end of the sine signal processing branch 210, the second end of the eleventh resistor R11 is connected to the in-phase input end of the third operational amplifier A3, the first end of the twelfth resistor R12 is connected to the output end of the cosine signal processing branch 220, the second end of the twelfth resistor R12 is connected to the second end of the eleventh resistor R11, and the output end of the third operational amplifier A3 is used as the output end of the adder circuit 230.

[0094] In this embodiment, the in-phase input terminal of the adder circuit 230 is respectively input with the single-ended sinusoidal output signal Q d The square signal U q (ie, the first processed signal), and the single-ended cosine output signal I d The square signal U i By flexibly setting the resistance values ​​of the ninth resistor R9, the tenth resistor R10, the eleventh resistor R11, and the twelfth resistor R12 in the adder circuit 230, for example, setting R9=R10, R11=R12, the third processed signal U output by the adder circuit 230 can be made s is the sum of the first processed signal and the second processed signal, that is:

[0095] U s =U i +U q =E 0 2 *(sin(ωt)) 2 =0.5*E 0 2 *[1-cos(2ωt)]

[0096] The low-pass filter circuit 240 is used to perform low-pass filtering on the third processed signal to obtain a target DC signal.

[0097] By using the low-pass filter circuit 240 to filter out the third processing signal U s The high frequency signal in can be obtained by out Signal,U out The signal is a stable DC signal, that is, a target DC signal.

[0098] In an optional implementation of this embodiment, as Figure 8 As shown, the low-pass filter circuit 240 may specifically include:

[0099] a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a capacitor C and a fourth operational amplifier A4;

[0100] Among them, the first end of the thirteenth resistor R13 is connected to the output end of the adder circuit 230, the second end of the thirteenth resistor R13 is respectively connected to the first end of the capacitor C, the first end of the fourteenth resistor R14 and the inverting input end of the fourth operational amplifier A4, the second end of the capacitor C is respectively connected to the second end of the fourteenth resistor R14 and the output end of the fourth operational amplifier A4, the first end of the fifteenth resistor R15 is connected to the ground end, the second end of the fifteenth resistor R15 is connected to the non-inverting input end of the fourth operational amplifier A4, and the output end of the fourth operational amplifier A4 is used as the output end of the low-pass filter circuit, that is, the output target DC signal U out .

[0101] In this embodiment, Figure 8 The connection mode of R14 is a dotted line connection, which means that when constructing the low-pass filter circuit 240, in addition to using R14 in parallel at both ends of the capacitor C, R14 can also be replaced by the equivalent resistance of the capacitor C itself, that is, in the low-pass filter circuit 240, R14 can be connected or not, and the specific situation can be determined according to the actual circuit design parameters.

[0102] Under the action of the low-pass filter circuit 240,

[0103] The comparator circuit 250 is used to compare the amplitude of the target DC signal with the first comparison level and the second comparison level respectively, and output two level values ​​obtained after comparison.

[0104] The inventors have found through research that when the rotary transformer has problems such as disconnection or abnormal angle output during actual use, the voltage amplitude of the sine output signal and the cosine output signal collected at the two return winding ends of the rotary transformer will exceed a preset voltage amplitude range. Furthermore, in order to simply and efficiently detect the above abnormal problems, the embodiments of the present invention propose to detect the stability of the output signal of the rotary transformer by detecting whether the voltage amplitude of the sine output signal and the cosine output signal is within the preset voltage amplitude range.

[0105] Accordingly, the first comparison level and the second comparison level are used to limit the amplitude range of the normal output signal of the rotary transformer. Those skilled in the art can set the values ​​of the first comparison level and the second comparison level according to actual conditions, and this embodiment does not limit this.

[0106] In an optional implementation of this embodiment, if Fig. 9 As shown, the comparator circuit 250 may specifically include:

[0107] A sixteenth resistor R16, a seventeenth resistor R17, an eighteenth resistor R18, a nineteenth resistor R19, a fifth operational amplifier A5, and a sixth operational amplifier A6;

[0108] Wherein, the first end of the sixteenth resistor R16 is respectively connected to the output end of the low-pass filter circuit 240 and the first end of the seventeenth resistor R17, the second end of the sixteenth resistor R16 is connected to the non-inverting input end of the fifth operational amplifier A5, the second end of the seventeenth resistor R17 is connected to the inverting input end of the sixth operational amplifier A6, the inverting input end of the fifth operational amplifier A5 is used to input the first comparison level, the non-inverting input end of the sixth operational amplifier A6 is used to input the second comparison level, the first end of the eighteenth resistor R18 is connected to the power supply end, the second end of the eighteenth resistor R18 is connected to the output end of the fifth operational amplifier A5, the first end of the nineteenth resistor R19 is connected to the power supply end, and the second end of the nineteenth resistor R19 is connected to the output end of the sixth operational amplifier A6;

[0109] The level value U outputted by the output terminal of the fifth operational amplifier A5 is out1 The target DC signal U used to measure the output of the low-pass filter circuit 240 out The comparison result with the first comparison level U1 is that the level value U1 outputted by the output terminal of the sixth operational amplifier A6 is out2 The target DC signal U used to measure the output of the low-pass filter circuit 240 out Comparison result with the second comparison level U2.

[0110] In order to meet actual level comparison requirements, those skilled in the art may flexibly set the values ​​of the sixteenth resistor R16, the seventeenth resistor R17, the eighteenth resistor R18 and the nineteenth resistor R19, and this embodiment does not limit this.

[0111] Specifically, the fifth operational amplifier A5 is used to compare the target DC signal U out and the voltage of the first comparison level U1, when U out When it is higher than U1, A5 outputs a high level U out1 ; when U out When it is lower than U1, A5 outputs a low level U out1 Similarly, the sixth operational amplifier A6 is used to compare the target DC signal U out and the voltage of the second comparison level U2. out When it is higher than U2, A5 outputs a low level U out2 ; when U out When it is lower than U2, A5 outputs high level U out2 .

[0112] In a specific example, the first comparison level U1 is less than the second comparison level U2, and the resolver signal stability judgment circuit collects the sine output signal and cosine output signal induced by the two return winding ends of the resolver in real time, and detects the two output level values ​​of the resolver signal stability judgment circuit in real time. out1 Or U out2 When any one of the items is at a low level, it can be determined that the resolver signal is unstable and some abnormal problem may occur. Accordingly, the two level values ​​output by the resolver signal stability judgment circuit can be obtained through a microprocessor, for example, a computing chip set on the main control circuit in the resolver circuit system, and based on these two level values, combined with other acquisition or calculation parameters, the working state of the resolver is comprehensively analyzed to determine the specific problem of the resolver.

[0113] The technical solution of the embodiment of the present invention, by using a sine signal processing branch, a cosine signal processing branch, an adder circuit, a low-pass filter circuit and a comparator circuit built by analog devices, constructs a resolver signal stability judgment circuit in a pure hardware form, which can detect in real time whether the output signals of the two return winding ends of the resolver are within the effective signal amplitude range, so as to achieve the effect of timely and accurately prompting various types of broken wires or abnormal angle output problems that may occur during the use of the resolver without occupying any computing power. The implementation is simple, the cost is low, the real-time performance is good, and the load of the computing chip in the resolver circuit system can be effectively reduced.

[0114] Further, in Fig.10 FIG. 2 shows a schematic diagram of a specific resolver signal stability determination circuit provided by an embodiment of the present invention. Fig.10 As shown, the resolver signal stability judgment circuit first converts the input resolver sine (sin) signal and resolver cosine (cos) signal into single-ended signals respectively. Then, the two single-ended signals are multiplied by themselves respectively to obtain two multiplied signals. The two signals are input into the adder for summing. The summed signal is processed by a low-pass filter to filter out high-frequency noise. Finally, the DC signal after the low-pass filter is sent to the comparator to be compared with comparison level 1 and comparison level 2 respectively, thereby outputting the two level signals required for monitoring, level output 1 and level output 2.

[0115] Compared with the existing solutions, the rotary transformer monitoring method proposed in the present invention has the following advantages:

[0116] 1. It can greatly reduce the CPU load: use pure hardware to monitor the two signals of the resolver and convert the analog signal into a digital signal for monitoring.

[0117] 2. Simple implementation: Signal monitoring can be achieved by using only common op amps, resistors, capacitors and multipliers.

[0118] 3. High real-time performance: It can provide real-time feedback on whether the current input signal is within the range.

[0119] Furthermore, the embodiments of the present invention are applicable to various fields requiring high-precision position control, such as aviation, industrial control, automation, etc.

[0120] Fig.11 Schematic diagram of a rotary transformer circuit system provided by an embodiment of the present invention. Fig.11 As shown, the resolver circuit system may specifically include: a main control circuit 1110, a resolver 1120, and a resolver signal stability judgment circuit 1130 as described in any one of the embodiments of the present invention.

[0121] The main control circuit 1110 is connected to the rotary transformer 1120 and the rotary transformer signal stability judgment circuit 1130 respectively, and the rotary transformer 1120 is connected to the rotary transformer signal stability judgment circuit 1130;

[0122] The main control circuit 1110 is used to generate an excitation reference signal and output it to the excitation winding end of the rotary transformer 1120;

[0123] The rotary transformer 1120 is used to generate a sine output signal and a cosine output signal at two return winding ends under the action of an excitation reference signal, and feed the sine output signal and the cosine output signal back to the main control circuit 1120 and the rotary transformer signal stability judgment circuit 1130 respectively;

[0124] The resolver signal stability judgment circuit 1130 is used to generate two level values ​​according to the received sine output signal and cosine output signal and provide them to the main control circuit 1110;

[0125] The main control circuit 1110 is also used to demodulate the rotor angle of the resolver according to the received sine output signal and cosine output signal, and to verify the signal stability of the resolver 1120 according to the level value provided by the resolver signal stability judgment circuit 1130.

[0126] In this embodiment, a computing chip, such as a CPU, is provided in the main control circuit 1110. In this embodiment, the computing chip does not need to set up a separate computing logic to determine the stability of the output signal of the rotary transformer. It only needs to receive two level values ​​output by the rotary transformer signal stability judgment circuit 1130 to preliminarily determine that the rotary transformer 1120 has an abnormal problem. Then, the specific problem of the rotary transformer 1120 can be clearly located in combination with other parameters. This operation method can use the minimum hardware cost and greatly reduce the computing load of the computing chip.

[0127] Fig.12 Schematic diagram of a vehicle structure provided by an embodiment of the present invention. Fig.12 As shown, the vehicle includes a rotary transformer circuit system 1210 as described in any one of the embodiments of the present invention.

[0128] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0129] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A resolver signal stability judgment circuit, characterized in that: include: A sine signal processing branch, a cosine signal processing branch, an adder circuit, a low-pass filter circuit and a comparator circuit; The sine signal processing branch and the cosine signal processing branch are respectively connected to the adder circuit, and the adder circuit, the low-pass filter circuit and the comparator circuit are connected in sequence; A sinusoidal signal processing branch, used for collecting a sinusoidal output signal from a first return winding end of the rotary transformer, and performing a square operation on the sinusoidal output signal to obtain a first processed signal; A cosine signal processing branch, used for collecting a cosine output signal from a second return winding end of the rotary transformer, and performing a square operation on the cosine output signal to obtain a second processed signal; an adder circuit, configured to perform an addition operation on the first processed signal and the second processed signal to obtain a third processed signal; A low-pass filter circuit, used for performing low-pass filtering on the third processed signal to obtain a target DC signal; The comparator circuit is used to compare the amplitude of the target DC signal with the first comparison level and the second comparison level respectively, and output the two level values ​​obtained after comparison.

2. The resolver signal stability judgment circuit according to claim 1, characterized in that: The sinusoidal signal processing branch includes: A first differential amplifier circuit and a first hardware multiplier connected in sequence, wherein an output terminal of the first differential amplifier circuit is respectively connected to two input terminals of the first hardware multiplier; The in-phase input terminal and the in-phase input terminal of the first differential amplifier circuit are respectively used to input two sinusoidal output signals of the same frequency and inverted phases, and the output terminal of the first hardware multiplier is used as the output terminal of the sinusoidal signal processing branch.

3. The resolver signal stability judgment circuit according to claim 2, characterized in that: The first differential amplifier circuit specifically comprises: a first resistor, a second resistor, a third resistor, a fourth resistor and a first operational amplifier; Among them, the first end of the first resistor is connected to the power supply terminal, the second end of the first resistor is respectively connected to the first end of the second resistor and the non-inverting input terminal of the first operational amplifier, the second end of the second resistor is connected to the ground terminal, the first end of the third resistor is connected to the power supply terminal, the second end of the third resistor is respectively connected to the first end of the fourth resistor and the inverting input terminal of the first operational amplifier, and the second end of the fourth resistor is connected to the output terminal of the first operational amplifier.

4. The resolver signal stability judgment circuit according to claim 1, characterized in that: The cosine signal processing branch specifically includes: A second differential amplifier circuit and a second hardware multiplier connected in sequence, wherein an output end of the second differential amplifier circuit is respectively connected to two input ends of the second hardware multiplier; The in-phase input terminal and the inverting input terminal of the second differential amplifier circuit are respectively used to input two cosine output signals of the same frequency and inverted phases, and the output terminal of the second hardware multiplier is used as the output terminal of the cosine signal processing branch.

5. The resolver signal stability judgment circuit according to claim 4, characterized in that: The second differential amplifier circuit specifically comprises: a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, and a second operational amplifier; Among them, the first end of the fifth resistor is connected to the power supply terminal, the second end of the fifth resistor is respectively connected to the first end of the sixth resistor and the in-phase input terminal of the second operational amplifier, the second end of the sixth resistor is connected to the ground terminal, the first end of the seventh resistor is connected to the power supply terminal, the second end of the seventh resistor is respectively connected to the first end of the eighth resistor and the inverting input terminal of the second operational amplifier, and the second end of the eighth resistor is connected to the output terminal of the second operational amplifier.

6. The resolver signal stability judgment circuit according to any one of claims 1 to 5, characterized in that: The adder circuit specifically comprises: a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor and a third operational amplifier; Among them, the first end of the ninth resistor is connected to the ground end, the second end of the ninth resistor is respectively connected to the first end of the tenth resistor and the inverting input end of the third operational amplifier, the second end of the tenth resistor is connected to the output end of the third operational amplifier, the first end of the eleventh resistor is connected to the output end of the sine signal processing branch, the second end of the eleventh resistor is connected to the in-phase input end of the third operational amplifier, the first end of the twelfth resistor is connected to the output end of the cosine signal processing branch, the second end of the twelfth resistor is connected to the second end of the eleventh resistor, and the output end of the third operational amplifier is used as the output end of the adder circuit.

7. The resolver signal stability judgment circuit according to any one of claims 1 to 5, characterized in that: The low-pass filter circuit specifically comprises: a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a capacitor, and a fourth operational amplifier; Among them, the first end of the thirteenth resistor is connected to the output end of the adder circuit, the second end of the thirteenth resistor is respectively connected to the first end of the capacitor, the first end of the fourteenth resistor and the inverting input end of the fourth operational amplifier, the second end of the capacitor is respectively connected to the second end of the fourteenth resistor and the output end of the fourth operational amplifier, the first end of the fifteenth resistor is connected to the ground end, the second end of the fifteenth resistor is connected to the non-inverting input end of the fourth operational amplifier, and the output end of the fourth operational amplifier is used as the output end of the low-pass filter circuit.

8. The resolver signal stability judgment circuit according to any one of claims 1 to 5, characterized in that: The comparator circuit specifically comprises: a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a fifth operational amplifier, and a sixth operational amplifier; Wherein, the first end of the sixteenth resistor is connected to the output end of the low-pass filter circuit and the first end of the seventeenth resistor respectively, the second end of the sixteenth resistor is connected to the non-inverting input end of the fifth operational amplifier, the second end of the seventeenth resistor is connected to the inverting input end of the sixth operational amplifier, the inverting input end of the fifth operational amplifier is used to input the first comparison level, and the non-inverting input end of the sixth operational amplifier is used to input the second comparison level, the first end of the eighteenth resistor is connected to the power supply end, the second end of the eighteenth resistor is connected to the output end of the fifth operational amplifier, the first end of the nineteenth resistor is connected to the power supply end, and the second end of the nineteenth resistor is connected to the output end of the sixth operational amplifier; Among them, the level value outputted by the output end of the fifth operational amplifier is used to measure the comparison result between the target DC signal outputted by the low-pass filter circuit and the first comparison level, and the level value outputted by the output end of the sixth operational amplifier is used to measure the comparison result between the target DC signal outputted by the low-pass filter circuit and the second comparison level.

9. A rotary transformer circuit system, characterized in that: include: A main control circuit, a resolver, and a resolver signal stability judgment circuit as claimed in any one of claims 1 to 8; Wherein, the main control circuit is connected to the rotary transformer and the rotary transformer signal stability judgment circuit respectively, and the rotary transformer is connected to the rotary transformer signal stability judgment circuit; A main control circuit, used for generating an excitation reference signal and outputting it to an excitation winding end of a rotary transformer; The rotary transformer is used to generate a sine output signal and a cosine output signal at two return winding ends respectively under the action of an excitation reference signal, and feed the sine output signal and the cosine output signal back to a main control circuit and a rotary transformer signal stability judgment circuit respectively; The resolver signal stability judgment circuit is used to generate two level values ​​according to the received sine output signal and cosine output signal and provide them to the main control circuit; The main control circuit is also used to demodulate the rotor angle of the resolver according to the received sine output signal and cosine output signal, and to verify the signal stability of the resolver according to the level value provided by the resolver signal stability judgment circuit.

10. A vehicle, characterized in that: Comprising the rotary transformer circuit system as claimed in claim 9.

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