Abnormality detection device for rotary transformer

Abstract

The present application provides an abnormality detection device for a rotary transformer, which can at least determine the abnormality of the first system even when the period of the excitation AC voltage of the first system is different from the period of the excitation AC voltage of the second system and magnetic interference occurs between the systems. The abnormality detection device for the rotary transformer applies an AC voltage of a first period (TA) to the excitation winding (10A) of the first system, applies an AC voltage of a second period (TB) different from the first period (TA) to the excitation winding (10B) of the second system, performs a DC extraction process to reduce the component of the first period TA on the detection values ​​(V1A_F, V2A_F) of the output signals of the two output windings of the first system after the second period component reduction process, calculates the DC values ​​(V1A_DC, V2A_DC) of the two output signals of the first system, and determines the abnormality of the first system based on whether the DC values ​​(V1A_DC, V2A_DC) of the two output signals of the first system are within a normal range.

Description

Technical Field

[0001] The present application relates to an abnormality detection device for a rotary transformer. Background Art

[0002] As an angle detector for detecting the rotation angle of a motor, a resolver is often used. The resolver is known as a robust angle detector, but due to the requirement for fault tolerance of the motor drive system, the resolver also needs redundancy.

[0003] Therefore, Patent Document 1 discloses a dual-system resolver including a first-system field winding and an output winding and a second-system field winding and an output winding.

[0004] In addition, Patent Document 2 discloses a technique in which first and second resolver sensors are provided, and in which the amplitude sinωt of the output signal of the sin phase and the amplitude cosωt of the output signal of the cos phase do not satisfy (sinωt) 2 +(cosωt) 2 =1, it is determined that the two resolver signal lines are short-circuited to each other.

[0005] In addition, although there is no redundancy, patent document 3 discloses a technology that detects a failure of an angle detector that outputs a sine wave signal and a cosine wave signal corresponding to the rotor position of a brushless DC motor based on whether the sum of the square values ​​of the sine wave signal and the cosine wave signal is within a specified range.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2000-18968

[0009] Patent Document 2: Japanese Patent Application Publication No. 2005-147791

[0010] Patent Document 3: Japanese Patent Application Publication No. 2006-335252 Summary of the invention

[0011] Technical problem to be solved by the invention

[0012] However, in the rotary transformer of the redundant system such as patent documents 1 and 2, magnetic interference will occur even if the first system and the second system constituting the redundant system are electrically insulated. As a result, the output signal of the output winding of one of the first system and the second system includes a component caused by the excitation AC voltage of the other system of the first system and the second system. For example, the output signal of the output winding of the first system includes a component caused by the excitation AC voltage applied to the excitation winding of the first system in addition to the component caused by the excitation AC voltage applied to the excitation winding of the second system. Similarly, the output signal of the output winding of the second system includes a component caused by the excitation AC voltage applied to the excitation winding of the first system in addition to the component caused by the excitation AC voltage applied to the excitation winding of the second system.

[0013] Patent Document 1 does not disclose a technique for determining an abnormality in each system of a resolver having such a first system and a second system. Also, Patent Document 3 does not disclose a technique for determining an abnormality in each system of a resolver of a redundant system.

[0014] In the technology of Patent Document 2, the phase difference between the output signals of the sin phase and cos phase of the first rotary transformer and the output signals of the sin phase and cos phase of the second rotary transformer is 180 degrees. In addition, the period of the AC voltage applied to the excitation coil of the first rotary transformer is the same as the period of the AC voltage applied to the excitation coil of the second rotary transformer. Therefore, in Patent Document 2, although the influence of magnetic interference between the first system and the second system is not described, if magnetic interference occurs, since the components caused by the excitation coil of the first rotary transformer contained in the output signals of the sin phase and cos phase of the first rotary transformer are in antiphase with the components caused by the excitation coil of the second rotary transformer, only the amplitude gain of the output signals of the sin phase and cos phase is reduced, and (sinωt) is still maintained. 2 +(cosωt) 2 =1 relationship.

[0015] Therefore, as shown in patent document 2, the period of the AC voltage applied to the excitation winding of the first system is the same as the period of the AC voltage applied to the excitation winding of the second system. When the two output signals of the first system and the two output signals of the second system are in phase or anti-phase, even if magnetic interference occurs between the systems, for each system, it can be considered that the abnormality can be determined based on the sum of the square values ​​of the two output signals.

[0016] However, when the period of the AC voltage applied to the excitation winding of the first system is different from the period of the AC voltage applied to the excitation winding of the second system, as described above, since the components caused by the excitation AC voltage of the second system are superimposed on the two output signals of the first system, and the periodic vibration component of the excitation AC voltage of the second system is superimposed on the sum of the square values ​​of the two output signals of the first system, the abnormality of the first system cannot be accurately determined based on the sum of the square values. Similarly, the abnormality of the second system cannot be accurately determined based on the sum of the square values ​​of the two output signals of the second system.

[0017] In addition, in order to improve redundancy, the first system and the second system can operate independently of each other, and the excitation AC voltage of the first system does not need to be synchronized with the excitation AC voltage of the second system. Instead, a rotating transformer is sought in which the period of the excitation AC voltage of the first system is different from the period of the excitation AC voltage of the second system.

[0018] Therefore, the purpose of the present application is to provide an abnormality detection device for a rotary transformer, which can at least determine the abnormality of the first system even when magnetic interference occurs between the systems due to the cycle of the excitation AC voltage of the first system being different from the cycle of the excitation AC voltage of the second system.

[0019] Technical means for solving technical problems

[0020] The abnormality detection device of the rotary transformer involved in the present application includes:

[0021] A rotary transformer having an excitation winding of a first system, two output windings of the first system, an excitation winding of a second system, and two output windings of the second system, and magnetic interference is generated between the first system and the second system;

[0022] an excitation part of a first system, the excitation part of the first system applying an AC voltage of a first period to an excitation winding of the first system;

[0023] an excitation section of a second system, the excitation section of the second system applying an AC voltage of a second cycle different from the first cycle to an excitation winding of the second system;

[0024] an output signal detection unit of a first system, the output signal detection unit of the first system detecting output signals of two output windings of the first system at a period that is less than half of the first period;

[0025] a first system reduction processing unit, the first system reduction processing unit performing a second period component reduction process on the detection values ​​of the output signals of the two output windings of the first system to reduce the components of the second period;

[0026] a DC extraction processing unit of the first system, which performs a DC extraction process of reducing the components of the first period on the detected values ​​of the output signals of the two output windings of the first system after the second period component reduction process, and calculates the DC values ​​of the two output signals of the first system; and

[0027] The abnormality detection unit of the first system determines the abnormality of the first system based on whether the DC values ​​of the two output signals of the first system are within a preset normal range of the first system.

[0028] Effects of the Invention

[0029] When an abnormality exists in the first system, the vibration center value of the first period component contained in the output signal detection value of the two output windings of the first system will be out of the normal range. According to the abnormality detection device of the rotary transformer involved in the present application, when the first period and the second period are different, and the output signal detection value of the two output windings of the first system contains the component of the second period caused by the excitation AC voltage of the second period of the second system due to the magnetic interference between the systems, the component of the second period can be reduced from the detection value of the output signal of the two output windings of the first system by reducing the second period component. Then, for the output signal detection value of the two output windings of the first system after the second period component reduction process, a DC extraction process of reducing the component of the first period is performed, so that the vibration center value (DC component) of the first period component contained in the output signal detection value of the two output windings of the first system can be calculated. Therefore, based on whether the DC value of the two output signals of the first system is within the normal range of the first system, the abnormality of the first system can be accurately determined. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 1 is a schematic configuration diagram of the resolver abnormality detection device according to the first embodiment.

[0031] Figure 2 This is a side view of the resolver according to the first embodiment as viewed along the axial direction.

[0032] Figure 3 This is a timing chart for explaining the detection timing of the first system according to the first embodiment, assuming that there is no magnetic interference between the systems.

[0033] Figure 4 This is a hardware configuration diagram of the control device according to the first embodiment.

[0034] Figure 5 This is a timing chart for explaining the second period component reduction process and the DC extraction process of the first system according to the first embodiment.

[0035] Figure 6 This is a block diagram of a reduction processing unit of the first system according to the first embodiment.

[0036] Figure 7 This is a flowchart for explaining the abnormality detection process of the first system involved in the first embodiment.

[0037] Figure 8 This is a flowchart for explaining another example of the abnormality detection process of the first system involved in the first embodiment.

[0038] Fig. 9 This is a timing chart for explaining the first period component reduction process and the DC extraction process of the second system involved in the first embodiment.

[0039] Fig.10 This is a block diagram of a reduction processing unit of the second system according to the first embodiment.

[0040] Fig.11 This is a flowchart for explaining the abnormality detection process of the second system involved in the first embodiment.

[0041] Fig.12 This is a flowchart for explaining another example of the abnormality detection process of the second system involved in the first embodiment.

[0042] Fig.13 This is a timing chart for explaining the first period component reduction process and the DC extraction process of the second system involved in the second embodiment.

[0043] Fig.14 This is a block diagram of a reduction processing unit of the second system according to the second embodiment.

[0044] Fig.15 1 is a schematic diagram of a configuration of a resolver abnormality detection device according to a third embodiment.

[0045] Fig.16 It is a schematic perspective view of a resolver according to the third embodiment. DETAILED DESCRIPTION

[0046] 1. Implementation Method 1

[0047] The resolver abnormality detection device according to the first embodiment will be described with reference to the drawings. Figure 1 2 is a schematic diagram of the configuration of the abnormality detection device for the resolver according to the present embodiment. The abnormality detection device for the resolver is also an angle detection device.

[0048] 1-1. Rotary transformer 1

[0049] The rotary transformer 1 includes a first system excitation winding 10A, two output windings 111A and 112A of the first system (also referred to as the first output winding 111A of the first system and the second output winding 112A of the first system), a second system excitation winding 10B, two output windings 111B and 112B of the second system (also referred to as the first output winding 111B of the second system and the second output winding 112B of the second system). Magnetic interference is generated between the windings of the first system and the windings of the second system. That is, electromagnetic induction caused by the magnetic flux generated by the excitation winding 10A of the first system generates an induced voltage not only in the two output windings 111A and 112A of the first system but also in the two output windings 111B and 112B of the second system, and electromagnetic induction caused by the magnetic flux generated by the excitation winding 10B of the second system generates an induced voltage not only in the two output windings 111B and 111B of the second system but also in the two output windings 111A and 112A of the first system.

[0050] like Figure 2 As shown, the excitation winding 10A of the first system, the two output windings 111A and 112A of the first system, the excitation winding 10B of the second system, and the two output windings 111B and 112B of the second system are wound on the same stator 13. The rotor 14 is arranged on the radial inner side of the stator 13. The rotor 14 includes a plurality of protrusions uniformly arranged circumferentially on the outer periphery. The protrusion height of the protrusion to the radial outer side is formed in such a way that the gap permeance between the stator 13 and the rotor 14 changes in a sinusoidal wave shape with rotation. That is, the rotary transformer 1 is a variable reluctance (VR) type rotary transformer. This embodiment is provided with 5 protrusions, in which the shaft angle is set to 5. Therefore, for every rotation of the rotor by 1 mechanical angle, it rotates 5 electrical angles.

[0051] like Figure 3 As shown in the example assuming that there is no magnetic interference between the systems, when the rotor rotates, in a state where the AC voltage VRA is applied to the excitation winding 10A of the first system, the amplitude of the AC voltage V1A induced in the first output winding 111A of the first system and the amplitude of the AC voltage V2A induced in the second output winding 112A of the first system change in a sine wave shape (or a cosine wave shape) according to the rotation angle (air gap permeance) indicated by the electrical angle of the rotor. The first output winding 111A of the first system and the second output winding 112A of the first system are wound to the circumferential position of the stator 13 in such a manner that the amplitudes of their AC voltages differ from each other by 90 degrees in electrical angle. Similarly, the first output winding 111B of the second system and the second output winding 112B of the second system are wound to the circumferential position of the stator in such a manner that the amplitudes of their induced AC voltages differ from each other by 90 degrees in electrical angle.

[0052] In this embodiment, if Figure 2 As shown, the stator 13 includes 12 teeth uniformly arranged in the circumferential direction, the winding of the first system is wound on the 1st tooth TE1 to the 6th tooth TE6, and the winding of the second system is wound on the 7th tooth TE7 to the 12th tooth TE12. The excitation winding 10A of the first system is dispersedly wound on the 1st tooth TE1 to the 6th tooth TE6. The first output winding 111A of the first system and the second output winding 112A of the first system are dispersedly wound on the 1st tooth TE1 to the 6th tooth TE6 so that the amplitudes of the induced AC voltages differ from each other by 90 degrees. Similarly, the excitation winding 10B of the second system is dispersedly wound on the 7th tooth TE7 to the 12th tooth TE12. The first output winding 111B of the second system and the second output winding 112B of the second system are dispersedly wound on the 7th tooth TE7 to the 12th tooth TE12 so that the amplitudes of the induced AC voltages differ from each other by 90 degrees.

[0053] The first system excitation winding 10A wound on a plurality of teeth is connected in series between the teeth, and the two terminals of the first system excitation winding 10A connected in series are connected to the control device 50 (the excitation part 51A of the first system) described later. Similarly, the two terminals of the first system first output winding 111A connected in series between the teeth are connected to the control device 50 (the output signal detection part 52A of the first system) described later. The two terminals of the first system second output winding 112A connected in series between the teeth are connected to the control device 50 (the output signal detection part 52A of the first system) described later. In addition, the two terminals of the second system excitation winding 10B wound on a plurality of teeth are connected to the control device 50 (the excitation part 51B of the second system) described later. Similarly, the two terminals of the second system first output winding 111B connected in series between the teeth are connected to the control device 50 (the output signal detection part 52B of the second system) described later. The two terminals of the second system second output winding 112B connected in series between the teeth are connected to the control device 50 (the output signal detection part 52B of the second system) described later.

[0054] The number of protrusions (horizontal angle multiplier) and the number of teeth may be set to any number. The first system winding and the second system winding may not be arranged in two in the circumferential direction, but may be arranged in a dispersed manner in the circumferential direction.

[0055] 1-2. Control device 50

[0056] The abnormality detection device of the rotary transformer includes a control device 50. The control device 50 is as follows: Figure 1As shown, the control device 50 includes an excitation unit 51A of the first system, an output signal detection unit 52A of the first system, a reduction processing unit 53A of the first system, an angle calculation unit 54A of the first system, a DC extraction processing unit 55A of the first system, an abnormality detection unit 56A of the first system, an excitation unit 51B of the second system, an output signal detection unit 52B of the second system, a reduction processing unit 53B of the second system, an angle calculation unit 54B of the second system, a DC extraction processing unit 55B of the second system, and an abnormality detection unit 56B of the second system. Each function of the control device 50 is realized by a processing circuit provided in the control device 50.

[0057] Specifically, the control device 50 is as follows Figure 4 As shown, the processing circuit includes: a CPU (Central Processing Unit) and other operation processing devices 90 (computer); a storage device 91 for exchanging data with the operation processing device 90; an input circuit 92 for inputting external signals to the operation processing device 90; and an output circuit 93 for outputting signals from the operation processing device 90 to the outside.

[0058] The operation processing device 90 may include an ASIC (Application Specific Integrated Circuit), an IC (Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), various logic circuits, and various signal processing circuits. In addition, the operation processing device 90 may include a plurality of operation processing devices of the same type or different types to share the execution of each process. The storage device 91 may include a RAM (Random Access Memory) configured to read and write data from the operation processing device 90, and a ROM (Read Only Memory) configured to read data from the operation processing device 90. The first output winding 111A of the first system, the second output winding 112A of the first system, the first output winding 111B of the second system, and the second output winding 112B of the second system are connected to the input circuit 92. The input circuit 92 includes an A / D converter, etc., which inputs the output voltages of these windings to the operation processing device 90. The excitation winding 10A of the first system and the excitation winding 10B of the second system are connected to the output circuit 93, and the output circuit 93 includes a driving circuit such as a switch element for applying an AC voltage VRA to these windings. A low-pass filter circuit may be provided on the output side of the switch element. In addition, the output circuit 93 includes a signal output circuit such as a communication circuit that transmits the calculated first angle θ1 and second angle θ2, and the abnormal signal ERR1 of the first system and the abnormal signal ERR2 of the second system to the external control device 94.

[0059] Therefore, each function of each control unit 51A to 56B and the like included in the control device 50 is realized by the arithmetic processing unit 90 executing software (program) stored in a storage device 91 such as a ROM, and cooperating with other hardware of the control device 50 such as the storage device 91, the input circuit 92, and the output circuit 93. In addition, setting data used by each control unit 51A to 56B and the like is stored in the storage device 91 such as a ROM as part of the software (program). Hereinafter, each function of the control device 50 will be described in detail.

[0060] 1-2-1. Excitation department

[0061] The excitation unit 51A of the first system applies an AC voltage VRA of the first period TA (in this example, a sinusoidal AC voltage VRA) to the excitation winding 10A of the first system. The excitation unit 51A of the first system calculates an AC voltage command of the first period TA, and generates a PWM signal (Pulse Width Modulation) for turning on and off a switching element for the excitation winding 10A of the first system provided in the output circuit 93 based on a comparison result of the AC voltage command and the triangular wave. When the switching element is turned on, the power supply voltage is applied to the excitation winding 10A side of the first system, and when the switching element is turned off, the application of the power supply voltage is stopped.

[0062] The excitation unit 51B of the second system applies an AC voltage VRB of a second period TB (a sinusoidal AC voltage VRB in this example) to the excitation winding 10B of the second system. The second period TB is set to a period different from the first period TA. In this embodiment, as described later, the second period TB is set to twice the first period TA (TB=2×TA). For example, when TA=50μs, TB=100μs is set.

[0063] The second system excitation unit 51B calculates an AC voltage command of the second period TB, and generates a PWM signal for turning on and off a switching element for the second system excitation winding provided in the output circuit 93 based on a comparison result between the AC voltage command and the triangular wave.

[0064] 1-2-2. Output signal detection unit of the first system

[0065] The first system output signal detection unit 52A periodically detects the output signals V1A and V2A of the two output windings 111A and 112A of the first system at a preset detection timing. In this embodiment, as described later, the detection timing is set in consideration of the abnormality determination and angle calculation of the first system.

[0066] 1-2-3. Reduction processing unit of the first system

[0067] <Problems caused by magnetic interference between systems>

[0068] like Figure 5 As shown in the example of the output signal V1A of the first output winding of the first system, due to the magnetic interference between the systems, the output signals V1A and V2A of the two output windings 111A and 112A of the first system are respectively superimposed with the second period components V1A_TB and V2A_TB induced by the electromagnetic induction caused by the second period TB magnetic flux generated by the excitation of the excitation winding 10B of the second system. Figure 5The upper diagram shows the output signal V1A of the first output winding of the first system, the middle diagram shows the first period component V1A_TA induced by electromagnetic induction caused by the magnetic flux of the excitation winding 10A of the first system, and the lower diagram shows the second period component V1A_TB induced by electromagnetic induction caused by the magnetic flux of the excitation winding 10B of the second system. The output signal V1A of the first output winding of the first system is a signal obtained by summing the first period component V1A_TA and the second period component V1A_TB.

[0069] <Second cycle component reduction processing>

[0070] Therefore, the first system reduction processing unit 53A performs the second period component reduction processing for reducing the components of the second period on the detection values ​​V1A_S and V2A_S of the output signals of the two output windings of the first system.

[0071] In this embodiment, the second period component reduction process is performed based on the principle described below. Figure 5 As shown in the lower part of the figure, the component V1A_TB of the second period of the output signal of the first output winding of the first system undergoes phase reversal at a period that is half a period TB / 2 of the second period plus an integer multiple of the second period TB (for example, half a period TB / 2 of the second period), and the positive and negative signs are reversed.

[0072] Therefore, as the second period component reduction processing, the reduction processing unit 53A configured as the first system adds the detection values ​​V1A_S and V2A_S of the output signals of the two output windings of the first system detected at the current detection timing and the detection values ​​V1A_Sold and V2A_Sold of the output signals of the two output windings of the first system detected at the detection timing before the first system reduction processing interval ΔT1 of the current detection timing. The first system reduction processing interval ΔT1 is set as shown in the following formula. Here, M is an integer greater than 0. In the present embodiment, it is set to M=0, and the first system reduction processing interval ΔT1 is set to half the period TB / 2 of the second period.

[0073] ΔT1=TB / 2+TB×M··· (1)

[0074] The reduction processing unit 53A of the first system is, for example, Figure 6The first system reduction processing unit 53A includes a first delayer 53A1, which delays the detection value V1A_S of the output signal of the first output winding of the first system by the first system reduction processing interval ΔT1 and then outputs it. The first system reduction processing unit 53A adds the detection value V1A_S of the output signal of the first output winding of the first system and the output V1A_Sold of the first delayer 53A1 to calculate the detection value V1A_F of the output signal of the first output winding of the first system after the second period component reduction processing. Similarly, the reduction processing unit 53A of the first system includes a second delay device 53A2, which delays the detection value V2A_S of the output signal of the second output winding of the first system by the first system reduction processing interval ΔT1 and then outputs it. The reduction processing unit 53A of the first system adds the detection value V2A_S of the output signal of the second output winding of the first system and the output V2A_Sold of the second delay device 53A2 to calculate the detection value V2A_F of the output signal of the second output winding of the first system after the second periodic component reduction processing.

[0075] According to this structure, the components of the two second cycles with opposite signs are added, and the components of the two second cycles cancel each other out. Therefore, the components of the second cycle in the detection values ​​V1A_F and V2A_F of the output signals of the two output windings of the first system after addition are reduced. Then, using the components of the first cycle of the first system with the components of the second cycle of the second system reduced, the abnormality determination of the first system described later can be accurately performed.

[0076] In this embodiment, as shown in the following formula, the second period TB is set to an even multiple of the first period TA. Here, N is an integer greater than 1. In this embodiment, N=1 is set, and the second period TB is set to twice the first period TA. For example, when the first period TA is set to 50us, the second period TB is set to 100us.

[0077] TB=TA×2×N… (2)

[0078] According to this configuration, as shown in the following equation by substituting equation (2) into equation (1), the first system reduction processing interval ΔT1 becomes an integral multiple of the first cycle TA.

[0079] ΔT1=TA×(N+2×N×M)… (3)

[0080] Therefore, the values ​​before and after the integer multiple of the first period TA are added to the detection values ​​V1A_S and V2A_S of the output signals of the two output windings of the first system. Figure 5As shown, the two added components of the first cycle have the same phase and the same positive and negative signs, and thus are equal values. Therefore, the detection values ​​V1A_F and V2A_F of the output signals of the two output windings of the first system after addition are respectively equivalent to twice the values ​​of the components V1A_TA and V2A_TA of the first cycle contained in the detection values.

[0081] V1A_F≒2×V1A_TA

[0082] V2A_F≒2×V2A_TA… (4)

[0083] In this embodiment, M = 0, N = 1. Therefore, the reduction processing unit 53A of the first system is configured to add the detection values ​​V1A_S and V2A_S of the output signals of the two output windings of the first system detected at the current detection timing, and the detection values ​​V1A_Sold and V2A_Sold of the output signals of the two output windings of the first system detected before the first cycle TA (half cycle TB / 2 of the second cycle).

[0084] 1-2-4. Abnormality determination of the first system

[0085] <Principles of abnormality determination>

[0086] The detection values ​​V1A_F and V2A_F of the output signals of the two output windings of the first system after the second period component reduction processing (hereinafter also referred to as the two output signals V1A_F and V2A_F of the first system after the second period component reduction processing) are Figure 3 The behavior of the detection values ​​V1A_S and V2A_S of the output signals of the two output windings of the first system when there is no magnetic interference between the systems shown is the same. Therefore, when there is no abnormality in the first system, the two output signals V1A_F and V2A_F of the first system after the second periodic component reduction process vibrate with the first period TA around the specified voltage as the center, and the amplitude vibrates with the rotation period. It is difficult to determine whether there is an abnormality based on the instantaneous values ​​of the two output signals V1A_F and V2A_F of the first system after the second periodic component reduction process of such vibration. On the other hand, when there is no abnormality, since the vibration center value is the specified normal value, when the vibration center value changes and deviates from the normal value, it can be detected that an abnormality has occurred.

[0087] In order to calculate the vibration center values ​​of the two output signals V1A_F and V2A_F of the first system after the second period component reduction processing of vibrating with the first period TA, it is necessary to sample the output signals at a period less than half of the first period TA according to the sampling theorem.

[0088] <Detection cycle for abnormality determination>

[0089] Therefore, the output signal detection unit 52A of the first system periodically detects the output signals V1A and V2A of the two output windings 111A and 112A of the first system at a detection period for abnormality determination of the first system set to a period less than half of the first period TA. Figure 5 As shown, the output signal detection unit 52A of the first system detects the output signals V1A_S and V2A_S of the two output windings of the first system at the timing of every half cycle TA / 2 of the first cycle when the AC voltage VRA of the first cycle TA applied to the excitation winding 10A of the first system reaches the maximum value or the minimum value.

[0090] <Second cycle component reduction processing for abnormality determination>

[0091] Then, the first system reduction processing unit 53A performs the second period component reduction processing on the detection values ​​V1A_S and V2A_S of the two output signals V1A_S and V2A_S of the first system every half period TA / 2 of the first period of the two output signals V1A_S and V2A_S of the first system, and calculates the two output signals V1A_F and V2A_F of the first system after the second period component reduction processing. In the present embodiment, the first system reduction processing unit 53A adds the detection values ​​V1A_S and V2A_S of the two output signals of the first system detected this time to the detection values ​​V1A_Sold and V2A_Sold of the two output signals of the first system detected before the first system reduction processing interval ΔT1 (in this example, before the first period TA (or before an integer multiple of the first period TA)) every detection period for abnormality determination (in this example, every half period TA / 2 of the first period), and calculates the two output signals V1A_F and V2A_F of the first system after the second period component reduction processing.

[0092] <DC Extraction Processing Unit of the First System>

[0093] The first system DC extraction processing unit 55A performs DC extraction processing to reduce the components of the first period TA on the two output signals V1A_F and V2A_F of the first system after the second period component reduction processing, and calculates DC values ​​V1A_DC and V2A_DC of the two output signals of the first system.

[0094] In this embodiment, the DC extraction processing unit 55A of the first system performs moving average processing during the first cycle TA on the two output signals V1A_F and V2A_F of the first system after the second cycle component reduction processing, and calculates the DC values ​​V1A_DC and V2A_DC of the two output signals of the first system. In this example, the detection timing for abnormality determination and the timing of the second cycle component reduction processing are set to the timing of every half cycle TA / 2 of the first cycle. Therefore, as shown in the following formula, the DC extraction processing unit 55A of the first system calculates the average value of the two output signals V1A_F and V2A_F of the first system after the second cycle component reduction processing calculated at the current detection timing and the two output signals V1A_F_old and V2A_F_old of the first system after the second cycle component reduction processing calculated at the last detection timing before the half cycle TA / 2 of the first cycle as the DC values ​​V1A_DC and V2A_DC of the two output signals of the first system.

[0095] V1A_DC={V1A_F+V1A_F_old} / 2

[0096] V2A_DC={V2A_F+V2A_F_old} / 2…(5)

[0097] As explained using equation (4), the two output signals V1A_F and V2A_F of the first system after the second period component reduction process are equivalent to twice the values ​​of the components V1A_TA and V2A_TA of the first period. Fig. 9 It can be seen from the behavior of the component V1A_TA of the first cycle shown that the two output signals V1A_F and V2A_F of the first system after the second cycle component reduction processing calculated this time are inverted in phase with the two output signals V1A_F_old and V2A_F_old of the first system after the second cycle component reduction processing calculated last time before the half cycle TA / 2 of the first cycle. Therefore, by calculating the average value of the two, the vibration center value of the components V1A_TA and V2A_TA of the first cycle can be calculated.

[0098] Alternatively, the DC extraction processing unit 55A of the first system performs moving average processing on the two output signals V1A_F and V2A_F of the first system after the second periodic component reduction processing over a period of 2 or more natural number multiples of the first period TA, thereby calculating the DC values ​​V1A_DC and V2A_DC of the two output signals of the first system.

[0099] Alternatively, the DC extraction processing unit 55A of the first system may perform a band-stop filtering process on the two output signals V1A_F and V2A_F of the first system after the second period component reduction process to reduce the frequency band components including the frequency of the first period TA, thereby calculating the DC values ​​V1A_DC and V2A_DC of the two output signals of the first system. Alternatively, the DC extraction processing unit 55A of the first system may perform a low-pass filtering process with a cutoff frequency lower than the frequency of the first period TA on the two output signals V1A_F and V2A_F of the first system after the second period component reduction process, thereby calculating the DC values ​​V1A_DC and V2A_DC of the two output signals of the first system.

[0100] On the other hand, unlike the present embodiment, when the second period component reduction process is not performed and the second period component is superimposed on the two output signals of the first system, as shown in FIG. Figure 5 As shown, since the phase of the component T1A_TB of the second period is shifted by 90 degrees every half period TA / 2 of the first period, the vibration component of the second period TB will be superimposed on the DC value of the two output signals of the first system, and the vibration center values ​​of the components V1A_TA and V2A_TA of the first period cannot be accurately calculated.

[0101] <Abnormality Detection Unit of First System>

[0102] The first system abnormality detection unit 56A determines the abnormality of the first system based on whether the DC values ​​V1A_DC and V2A_DC of the two output signals of the first system are respectively within a preset normal range of the first system.

[0103] As described above, the DC values ​​V1A_DC and V2A_DC of the two output signals of the first system correspond to the vibration center values ​​of the first period components V1A_TA and V2A_TA included in the detection values ​​V1A_S and V2A_S of the two output signals of the first system.

[0104] The normal range of the first system is set to include the normal values ​​of the vibration center values ​​of the components V1A_TA and V2A_TA of the first period and to be between the lower limit value MIN1 of the first system and the upper limit value MAX1 of the first system. For example, the lower limit MIN1 of the first system is pre-set to a value that is smaller than the normal value of the vibration center values ​​of the components V1A_TA and V2A_TA of the first period (0 in this example) by a predetermined value, and the upper limit value MAX1 of the first system is pre-set to a value that is larger than the normal value of the vibration center value by a predetermined value. The setting of the normal range of the first system is adjusted according to the degree of abnormality to be determined as abnormal.

[0105] Furthermore, unlike the present embodiment, when the voltage range of the two output signals of the first system is 0 to 5V and the normal value of the vibration center value is 2.5V, the normal range of the first system is set to include 2.5V.

[0106] The abnormality of the first system includes abnormalities such as disconnection of each winding 10A, 111A, 112A of the first system, abnormalities in input and output circuits of each winding of the first system in the control device 50, and abnormalities in processing related to the first system of the control device 50.

[0107] use Figure 7 The flowchart of FIG. 1 illustrates the processing of abnormality determination. Figure 7 The processing of the flowchart is executed after calculating the DC values ​​V1A_DC and V2A_DC of the two output signals of the first system every detection cycle for abnormality determination. Figure 7 In the description, the abnormality determination using the DC value V1A_DC of the output signal of the first output winding of the first system is described, but the DC value V2A_DC of the output signal of the second output winding of the first system is also performed in the same manner.

[0108] In step S01, the abnormality detection unit 56A of the first system obtains the DC value V1A_DC of the output signal of the first output winding of the first system calculated by the DC extraction processing unit 55A of the first system. Then, in step S02, the abnormality detection unit 56A of the first system determines whether the DC value V1A_DC of the output signal of the first output winding of the first system is greater than the lower limit value MIN1 of the first system and less than the upper limit value MAX1 of the first system. That is, the abnormality detection unit 56A of the first system determines whether the DC value V1A_DC of the output signal of the first output winding of the first system is within the normal range of the first system.

[0109] When the abnormality detection unit 56A of the first system determines in step S02 that the DC value V1A_DC of the output signal of the first output winding of the first system is not within the normal range of the first system, the process proceeds to step S03 and determines that an abnormality has occurred in the first system. In the present embodiment, when the abnormality detection unit 56A of the first system determines that an abnormality has occurred in the first system, an abnormality signal ERR1 of the first system is output. For example, the abnormality signal ERR1 of the first system is transmitted to the external control device 94 to which the first angle θ1 is transmitted. When the control device 50 and the external control device 94 are integrated, the abnormality signal ERR1 of the first system is sent within the same control device.

[0110] On the other hand, when the first system abnormality detection unit 56A determines in step S02 that the DC value V1A_DC of the output signal of the first output winding of the first system is within the normal range of the first system, it determines that no abnormality has occurred in the first system and ends the processing.

[0111] <Other Examples of Abnormality Determination Processing>

[0112] use Figure 8 , describing another example of abnormality determination processing. Figure 8 The processing of the flowchart is executed after calculating the DC values ​​V1A_DC and V2A_DC of the two output signals of the first system at each detection cycle for abnormality determination. Figure 8 In the description, the abnormality determination using the DC value V1A_DC of the output signal of the first output winding of the first system is described, but the DC value V2A_DC of the output signal of the second output winding of the first system is also performed in the same manner.

[0113] In step S11, the abnormality detection unit 56A of the first system obtains the DC value V1A_DC of the output signal of the first output winding of the first system calculated by the DC extraction processing unit 55A of the first system. Then, in step S12, the abnormality detection unit 56A of the first system determines whether the DC value V1A_DC of the output signal of the first output winding of the first system is greater than the lower limit value MIN1 of the first system and less than the upper limit value MAX1 of the first system. That is, the abnormality detection unit 56A of the first system determines whether the DC value V1A_DC of the output signal of the first output winding of the first system is within the normal range of the first system.

[0114] When the abnormality detection unit 56A of the first system determines in step S12 that the DC value V1A_DC of the output signal of the first output winding of the first system is not within the normal range of the first system, the process proceeds to step S13 to increase the abnormality determination count value T1 by 1. Thereafter, the process proceeds to step S14 to determine whether the abnormality determination count value T1 is greater than the preset abnormality determination number T1ab.

[0115] When the abnormality detection unit 56A of the first system determines in step S14 that the abnormality determination count value T1 is greater than the abnormality determination times T1ab, the process proceeds to step S15 and determines that an abnormality has occurred in the first system. Then, when the abnormality detection unit 56A of the first system determines that an abnormality has occurred in the first system, an abnormality signal ERR1 of the first system is output. When the abnormality detection unit 56A of the first system determines in step S14 that the abnormality determination count value T1 is not greater than the abnormality determination times T1ab, the process determines that no abnormality has occurred in the first system and ends the process.

[0116] On the other hand, when the first system abnormality detection unit 56A determines in step S12 that the DC value V1A_DC of the output signal of the first output winding of the first system is within the normal range of the first system, the process proceeds to step S16, resets the abnormality determination count value T1 to 0, and ends the process.

[0117] exist Figure 8 In the example of the flowchart, the abnormality detection unit 56A of the first system determines that an abnormality has occurred in the first system when the DC value V1A_DC of the output signal of the first output winding of the first system is out of the normal range of the first system for more than a preset abnormality determination number T1ab.

[0118] Thus, judging by the abnormality judgment number T1ab can prevent misjudgment due to noise components generated in the DC value V1A_DC of the output signal of the first output winding of the first system. In addition, judging abnormality when it is continuously out of the normal range can improve the accuracy of abnormality judgment.

[0119] In addition, in step S16 , the abnormality detection unit 56A of the first system may not reset the abnormality determination count value T1 to 0, may keep the abnormality determination count value T1 at the previous value, or may decrease the abnormality determination count value T1.

[0120] 1-2-5. Angle calculation unit of the first system

[0121] As shown in the following equation, the first system angle calculation unit 54A calculates the first angle θ1 by calculating the arc tangent (arc tangent function) of the ratio of the output signal V1A_F of the first output winding of the first system after the second periodic component reduction processing and the output signal V2A_F of the second output winding of the first system.

[0122] θ1=tan -1 (V1A_F / V2A_F)…(6)

[0123] As shown in equation (4), the two output signals V1A_F and V2A_F of the first system after the second period component reduction process are respectively equivalent to the double values ​​of the first period components V1A_TA and V2A_TA included in the detection value. Therefore, as shown in the following equation by substituting equation (4) into equation (6), the first angle θ1 can be accurately calculated based on the ratio of the first period components V1A_TA and V2A_TA included in the detection value.

[0124] θ1≒tan -1 {(2×V1A_TA) / (2×V2A_TA)}

[0125] =tan -1 (V1A_TA / V2A_TA)…(7)

[0126] Although the first angle θ1 can also be calculated each time the two output signals V1A_F and V2A_F of the first system after the second period component reduction process are calculated (in this example, every half period TA / 2 of the first period), Figure 3 As shown, in the first cycle TA, the AC voltage VRA applied to the excitation winding 10A of the first system reaches a maximum value or a minimum value (at Figure 3 The calculation timing of (in the example of the maximum value) is used to calculate the first angle θ1.

[0127] 1-2-6. Output signal detection unit of the second system

[0128] The second system output signal detection unit 52B periodically detects the output signals V1B and V2B of the two output windings 111B and 112B of the second system at a preset detection timing. In this embodiment, as described later, the detection timing is set in consideration of abnormality determination and angle calculation of the second system.

[0129] 1-2-7. Reduction processing unit of the second system

[0130] <Problems caused by magnetic interference between systems>

[0131] like Fig. 9 As shown in the example of the output signal V1B of the first output winding of the second system, due to the magnetic interference between the systems, the first period component induced by the magnetic flux of the first period TA generated by the excitation of the excitation winding 10A of the first system will be superimposed on the output signals V1B and V2B of the two output windings 111B and 112B of the second system. Fig. 9 The upper diagram shows the output signal V1B of the first output winding of the second system, the middle diagram shows the second period component V1B_TB induced by electromagnetic induction caused by the magnetic flux of the excitation winding 10B of the second system included in the output signal V1B of the first output winding of the second system, and the lower diagram shows the first period component V1B_TA induced by electromagnetic induction caused by the magnetic flux of the excitation winding 10A of the first system included in the output signal V1B of the first output winding of the second system. The output signal V1B of the first output winding of the second system is a signal obtained by summing the second period component V1B_TB and the first period component V1B_TA.

[0132] <First cycle component reduction processing>

[0133] Therefore, the second system reduction processing unit 53B performs the first period component reduction processing for reducing the components of the first period on the detection values ​​V1B_S and V2B_S of the output signals of the two output windings of the second system.

[0134] In this embodiment, the second period component reduction process is performed based on the principle described below. Fig. 9 As shown in the lower graph, the period of the component V1B_TA of the first cycle of the output signal of the first output winding of the second system is the first cycle TA, and therefore has the same value every first cycle TA.

[0135] Therefore, as the first period component reduction processing, the reduction processing unit 53B of the second system is configured to perform a subtraction processing, and calculates the difference between the detection values ​​V1B_S and V2B_S of the output signals of the two output windings of the second system detected at the current detection timing and the detection values ​​V1B_Sold and V2B_Sold of the output signals of the two output windings of the second system detected at the detection timing before the second system reduction processing interval ΔT2 of the current detection timing. As shown in the following formula, the second system reduction processing interval ΔT2 is set to an integer multiple of the first period TA. Here, P is an integer greater than 1. In the present embodiment, it is set to P=1, and the second system reduction processing interval ΔT2 is set to the first period TA.

[0136] ΔT2=TA×P···(8)

[0137] The reduction processing unit 53B of the second system is, for example, Fig.10 The reduction processing unit 53B of the second system includes a first delayer 53B1, which delays the detection value V1B_S of the output signal of the first output winding of the second system by the second system reduction processing interval ΔT2 and then outputs it. The reduction processing unit 53B of the second system subtracts the output V1B_Sold of the first delayer 53B1 from the detection value V1B_S of the output signal of the first output winding of the second system, and calculates the detection value V1B_F of the output signal of the first output winding of the second system after the first period component reduction processing. Similarly, the reduction processing unit 53B of the second system includes a second delay 53B2, which delays the detection value V2B_S of the output signal of the second output winding of the second system by the second system reduction processing interval ΔT2 and then outputs it. The reduction processing unit 53B of the second system subtracts the output V2B_Sold of the second delay 53B2 from the detection value V2B_S of the output signal of the second output winding of the second system, and calculates the detection value V2B_F of the output signal of the second output winding of the second system after the first periodic component reduction processing.

[0138] According to this structure, two components of the first cycle with the same positive and negative signs and thus the same value are subtracted, so that the two components of the first cycle cancel each other. Therefore, in the detection values ​​V1B_F and V2B_F of the output signals of the two output windings of the second system after the subtraction process, the components of the first cycle are reduced. Thus, using the components of the second cycle of the second system with the components of the first cycle of the first system reduced, the abnormality determination of the second system described later can be accurately performed.

[0139] As described above, in this embodiment, the second period TB is set to an even multiple of the first period TA as shown in the following formula: Here, N is an integer greater than 1. In this embodiment, N=1 is set, and the second period TB is set to a value twice the first period TA.

[0140] TB=TA×2×N… (9)

[0141] The second system reduction processing interval ΔT2 is set as shown in the following equation. Here, L is an integer greater than or equal to 0. In the present embodiment, L=0 is set, and the second system reduction processing interval ΔT2 is set to half the second cycle TB / 2.

[0142] ΔT2=TB / 2+TB×L··· (10)

[0143] Even in this case, if equation (9) is substituted into equation (10), the second system reduction processing interval ΔT2 becomes an integer multiple of the first period TA as shown in equation (8) below. Therefore, as described above, the first period component reduction processing (subtraction processing) can reduce the first period component.

[0144] ΔT2=TA×N×(1+2×L)… (11)

[0145] Furthermore, by setting the second system reduction processing interval ΔT2 as in equation (10), the components of the two second periods subtracted by the subtraction processing are as follows: Fig. 9 Therefore, the detection values ​​V1B_F and V2B_F of the output signals of the two output windings of the second system after the subtraction process correspond to twice the values ​​of the components V1B_TB and V2B_TB of the second cycle included in the detection values.

[0146] V1B_F≒2×V1B_TB

[0147] V2B_F≒2×V2B_TB… (12)

[0148] In this embodiment, L = 0, N = 1, and P = 1 are set. Therefore, the reduction processing unit 53B of the second system is configured to subtract the detection values ​​V1B_Sold and V2B_Sold of the output signals of the two output windings of the second system detected before the half cycle TB / 2 of the second cycle (the first cycle TA) from the detection values ​​V1B_S and V2B_S of the output signals of the two output windings of the second system detected at the current detection timing.

[0149] 1-2-8. Abnormality determination of the second system

[0150] <Principles of abnormality determination>

[0151] The detection values ​​V1B_F and V2B_F of the output signals of the two output windings of the second system after the first period component reduction processing (hereinafter also referred to as the two output signals V1B_F and V2B_F of the second system after the first period component reduction processing) are Figure 3 The behavior of the detection values ​​V1A_S and V2A_S of the output signals of the two output windings of the first system when there is no magnetic interference between the systems shown is the same. Therefore, when there is no abnormality in the second system, the two output signals V1B_F and V2B_F of the second system after the first period component reduction process vibrate with the second period TB around the specified voltage as the center, and the amplitude vibrates with the rotation period. It is difficult to determine whether there is an abnormality by the instantaneous values ​​of the two output signals V1B_F and V2B_F of the second system after the first period component reduction process of such vibration. On the other hand, when there is no abnormality, since the vibration center value is the specified normal value, when the vibration center value changes and deviates from the normal value, it can be detected that an abnormality has occurred.

[0152] In order to calculate the vibration center values ​​of the two output signals V1B_F and V2B_F of the second system after the first period component reduction processing of vibrating with the second period TB, it is necessary to sample the output signals at a period less than half of the second period TB according to the sampling theorem.

[0153] <Detection cycle for abnormality determination>

[0154] Therefore, the output signal detection unit 52B of the second system periodically detects the output signals V1B and V2B of the two output windings 111B and 112B of the second system at a detection period for abnormality determination of the second system set to a period less than half of the second period TB. Fig. 9As shown, the output signal detection unit 52B of the second system detects the output signals V1B_S and V2B_S of the two output windings of the second system at the timing of every half cycle TB / 2 of the second cycle when the AC voltage VRB of the second cycle TB applied to the excitation winding 10B of the second system reaches the maximum value or the minimum value.

[0155] <First cycle component reduction processing for abnormality determination>

[0156] Then, the reduction processing unit 53B of the first system performs the first period component reduction processing on the detection values ​​V1B_S and V2B_S of the two output signals V1B_S and V2B_S of the second system every half period TB / 2 of the second period, and calculates the two output signals V1B_F and V2B_F of the second system after the first period component reduction processing. In the present embodiment, the reduction processing unit 53B of the second system subtracts the detection values ​​V1B_Sold and V2B_Sold of the two output signals of the second system detected before the second system reduction processing interval ΔT2 (in this example, before the second period TB (or before an integer multiple of the first period TA)) from the detection values ​​V1B_S and V2B_S of the two output signals of the second system detected this time every detection period for abnormality determination (in this example, every half period TB / 2 of the second period), and calculates the two output signals V1B_F and V2B_F of the second system after the first period component reduction processing.

[0157] <DC Extraction Processing Unit of Second System>

[0158] The second system DC extraction processing unit 55B performs DC extraction processing to reduce the components of the second period TB on the two output signals V1B_F and V2B_F of the second system after the first period component reduction processing, and calculates DC values ​​V1B_DC and V2B_DC of the two output signals of the second system.

[0159] In this embodiment, the DC extraction processing unit 55B of the second system performs moving average processing during the second cycle TB on the two output signals V1B_F and V2B_F of the second system after the first cycle component reduction processing, and calculates the DC values ​​V1B_DC and V2B_DC of the two output signals of the second system. In this example, the detection timing for abnormality determination and the timing of the first cycle component reduction processing are set to the timing of every half cycle TB / 2 of the second cycle. Therefore, as shown in the following formula, the DC extraction processing unit 55B of the second system calculates the average value of the two output signals V1B_F and V2B_F of the second system after the first cycle component reduction processing calculated at the current detection timing and the two output signals V1B_F_old and V2B_F_old of the second system after the first cycle component reduction processing calculated at the last detection timing before the half cycle TB / 2 of the second cycle as the DC values ​​V1B_DC and V2B_DC of the two output signals of the second system.

[0160] V1B_DC={V1B_F+V1B_F_old} / 2

[0161] V2B_DC={V2B_F+V2B_F_old} / 2…(13)

[0162] As explained using equation (12), the two output signals V1B_F and V2B_F of the second system after the first period component reduction process are equivalent to twice the values ​​of the components V1B_TB and V2B_TB of the second period. Fig. 9 It can be seen from the behavior of the component V1B_TB of the second cycle shown that the two output signals V1B_F and V2B_F of the second system after the first cycle component reduction processing calculated this time are inverted in phase with the two output signals V1B_F_old and V2BA_F_old of the second system after the first cycle component reduction processing calculated last time before the half cycle TB / 2 of the second cycle. Therefore, by calculating the average value of the two, the vibration center value of the components V1B_TB and V2B_TB of the second cycle can be calculated.

[0163] Alternatively, the DC extraction processing unit 55B of the second system can perform moving average processing on the two output signals V1B_F and V2B_F of the second system after the first periodic component reduction processing for a period of a natural number multiple of more than 2 times the second period TB, thereby calculating the DC values ​​V1B_DC and V2B_DC of the two output signals of the second system.

[0164] Alternatively, the DC extraction processing unit 55B of the second system may perform a band-stop filtering process on the two output signals V1B_F and V2B_F of the second system after the first period component reduction process to reduce the frequency band component including the frequency of the second period TB, thereby calculating the DC values ​​V1B_DC and V2B_DC of the two output signals of the second system. Alternatively, the DC extraction processing unit 55B of the second system may perform a low-pass filtering process with a cutoff frequency smaller than the frequency of the second period TB on the two output signals V1B_F and V2B_F of the second system after the first period component reduction process, thereby calculating the DC values ​​V1B_DC and V2B_DC of the two output signals of the second system.

[0165] On the other hand, unlike the present embodiment, when the first period component reduction process is not performed and the first period component is superimposed on the two output signals of the second system, as shown in FIG. Fig. 9 As shown, the component T1B_TA of the first cycle becomes the same value every half cycle TB / 2 of the second cycle, so the component of the first cycle TA is superimposed on the DC value of the two output signals of the second system, causing deviation. The deviation value changes according to the phase difference between the second cycle TB and the first cycle TA, so the vibration center value of the components V1B_TB and V2B_TB of the second cycle cannot be accurately calculated.

[0166] <Abnormality Detection Unit of Second System>

[0167] The second system abnormality detection unit 56B determines the abnormality of the second system based on whether the DC values ​​V1B_DC and V2B_DC of the two output signals of the second system are respectively within a preset normal range of the second system.

[0168] As described above, the DC values ​​V1B_DC and V2B_DC of the two output signals of the second system correspond to the vibration center values ​​of the components V1B_TB and V2B_TB of the second period included in the detection values ​​V1B_S and V2B_S of the two output signals of the second system.

[0169] The normal range of the second system is set to a range between the lower limit value MIN2 of the second system including the normal values ​​of the vibration center values ​​of the components V1B_TB and V2B_TB of the second period and the upper limit value MAX2 of the second system. For example, the lower limit value MIN2 of the second system is pre-set to a value smaller than the normal value (0 in this example) of the vibration center values ​​of the components V1B_TB and V2B_TB of the second period by a predetermined value, and the upper limit value MAX2 of the second system is pre-set to a value larger than the normal value of the vibration center value by a predetermined value. The setting of the normal range of the second system is adjusted according to the degree of abnormality to be determined as abnormal.

[0170] In addition, in a case where the voltage range of two output signals of the second system different from the present embodiment is 0 to 5V and the normal value of the vibration center value is 2.5V, the normal range of the second system is set to include 2.5V.

[0171] The abnormality of the second system includes abnormalities such as disconnection of each winding 10B, 111B, 112B of the second system, abnormalities in input and output circuits of each winding of the second system in the control device 50, and abnormalities in processing related to the second system of the control device 50.

[0172] use Fig.11 The flowchart of FIG. 1 illustrates the processing of abnormality determination. Fig.11 The processing of the flowchart is executed after calculating the DC values ​​V1B_DC and V2B_DC of the two output signals of the second system at each detection cycle for abnormality determination. Fig.11 In the description, the abnormality determination using the DC value V1B_DC of the output signal of the first output winding of the second system is described, but the DC value V2B_DC of the output signal of the second output winding of the second system is also performed in the same manner.

[0173] In step S31, the abnormality detection unit 56B of the second system obtains the DC value V1B_DC of the output signal of the first output winding of the second system calculated by the DC extraction processing unit 55B of the second system. Then, in step S32, the abnormality detection unit 56B of the second system determines whether the DC value V1B_DC of the output signal of the first output winding of the second system is above the lower limit value MIN2 of the second system and below the upper limit value MAX2 of the second system. That is, the abnormality detection unit 56B of the second system determines whether the DC value V1B_DC of the output signal of the first output winding of the second system is within the normal range of the second system.

[0174] When the abnormality detection unit 56B of the second system determines in step S32 that the DC value V1B_DC of the output signal of the first output winding of the second system is not within the normal range of the second system, the process proceeds to step S33 and determines that an abnormality has occurred in the second system. In the present embodiment, when the abnormality detection unit 56B of the second system determines that an abnormality has occurred in the second system, an abnormality signal ERR2 of the second system is output. For example, the abnormality signal ERR2 of the second system is transmitted to the external control device 94 to which the second angle θ2 is transmitted. When the control device 50 and the external control device 94 are integrated, the abnormality signal ERR2 of the second system is sent in the same control device.

[0175] On the other hand, when the second system abnormality detection unit 56B determines in step S32 that the DC value V1B_DC of the output signal of the first output winding of the third system is within the normal range of the second system, it determines that no abnormality has occurred in the second system and ends the processing.

[0176] <Other Examples of Abnormality Determination Processing>

[0177] use Fig.12 , describing another example of abnormality determination processing. Fig.12 The processing of the flowchart is executed after calculating the DC values ​​V1B_DC and V2B_DC of the two output signals of the second system at each detection cycle for abnormality determination. Fig.12 In the description, the abnormality determination using the DC value V1B_DC of the output signal of the first output winding of the second system is described, but the DC value V2B_DC of the output signal of the second output winding of the second system is also performed in the same manner.

[0178] In step S41, the abnormality detection unit 56B of the second system obtains the DC value V1B_DC of the output signal of the first output winding of the second system calculated by the DC extraction processing unit 55B of the second system. Then, in step S42, the abnormality detection unit 56B of the second system determines whether the DC value V1B_DC of the output signal of the first output winding of the second system is above the lower limit value MIN2 of the second system and below the upper limit value MAX2 of the second system. That is, the abnormality detection unit 56B of the second system determines whether the DC value V1B_DC of the output signal of the first output winding of the second system is within the normal range of the second system.

[0179] When the abnormality detection unit 56B of the second system determines in step S42 that the DC value V1B_DC of the output signal of the first output winding of the second system is not within the normal range of the second system, the process proceeds to step S43 and increases the abnormality determination count value T2 by 1. Thereafter, the process proceeds to step S44 and the abnormality detection unit 56B of the second system determines whether the abnormality determination count value T2 is greater than the preset abnormality determination number T2ab.

[0180] When the abnormality detection unit 56B of the second system determines in step S44 that the abnormality determination count value T2 is greater than the abnormality determination times T2ab, the process proceeds to step S45 and determines that an abnormality has occurred in the second system. Then, when the abnormality detection unit 56B of the second system determines that an abnormality has occurred in the second system, an abnormality signal ERR2 of the second system is output. When the abnormality detection unit 56B of the second system determines in step S44 that the abnormality determination count value T2 is not greater than the abnormality determination times T2ab, the process determines that no abnormality has occurred in the second system and ends the process.

[0181] On the other hand, when the second system abnormality detection unit 56B determines in step S42 that the DC value V1B_DC of the output signal of the first output winding of the second system is within the normal range of the second system, the process proceeds to step S46, resets the abnormality determination count value T2 to 0, and ends the process.

[0182] exist Fig.12 In the example of the flowchart, the abnormality detection unit 56B of the second system determines that an abnormality has occurred in the second system when the DC value V1B_DC of the output signal of the first output winding of the second system is out of the normal range of the second system for more than a predetermined abnormality determination number T2ab.

[0183] Thus, judging by the abnormality judgment number T2ab can prevent misjudgment due to noise components generated in the DC value V1B_DC of the output signal of the first output winding of the second system. In addition, judging abnormality when it is continuously out of the normal range can improve the accuracy of abnormality judgment.

[0184] In addition, in step S46 , the abnormality detection section 56B of the second system may not reset the abnormality determination count value T2 to 0, may maintain the abnormality determination count value T2 at the previous value, or may decrease the abnormality determination count value T2.

[0185] 1-2-9. Angle calculation unit of the second system

[0186] As shown in the following equation, the second system angle calculation unit 54B calculates the second angle θ2 by calculating the arc tangent (arc tangent function) of the ratio of the output signal V1B_F of the first output winding of the second system after the first periodic component reduction process to the output signal V2B_F of the second output winding of the second system.

[0187] θ2=tan -1 (V1B_F / V2B_F)…(14)

[0188] As shown in equation (12), the two output signals V1B_F and V2B_F of the second system after the first period component reduction process are equivalent to twice the values ​​of the second period components V1B_TB and V2B_TB included in the detection value. Therefore, as shown in the following equation by substituting equation (12) into equation (14), the second angle θ2 can be accurately calculated based on the ratio of the second period components V1B_TB and V2B_TB included in the detection value.

[0189] θ2≒tan -1 {(2×V1B_TB) / (2×V2B_TB)}

[0190] =tan -1(V1B_TB / V2B_TB)…(15)

[0191] Although the second angle θ2 can also be calculated each time the two output signals V1B_F and V2B_F of the second system are calculated after the first cycle component reduction processing (in this case, every half cycle TB / 2 of the second cycle), the second angle θ2 is calculated at the calculation timing when the AC voltage VRB of the second cycle TB applied to the excitation winding 10B of the second system reaches the maximum value or minimum value (for example, the maximum value).

[0192] In addition, it is only necessary to pre-set the setting values ​​such as the first period TA, the second period TB, the detection timing of the first system, the detection timing of the second system, the first system reduction processing interval ΔT1 and the second system reduction processing interval ΔT2 so that the prescribed relationship is satisfied between the first system and the second system. The processing of the first system and the processing of the second system can be performed independently of each other, and there is no need for real-time synchronous control between the first system and the second system.

[0193] 2. Implementation Method 2

[0194] Next, the abnormality detection device for the rotary transformer involved in the second embodiment is described. The description of the same structural parts as those in the first embodiment is omitted. The basic structure of the angle detection device involved in this embodiment is the same as that in the first embodiment, but the structure of the output signal detection unit 52B of the second system, the reduction processing unit 53B of the second system, and the DC extraction processing unit 55B of the second system of the control device 50 is different from that in the first embodiment.

[0195] The second system output signal detector 52B periodically detects the output signals V1B and V2B of the two output windings 111B and 112B of the second system at a preset detection timing. In this embodiment, as described later, the detection timing is also set in consideration of abnormality determination and angle calculation of the second system.

[0196] <Problems caused by magnetic interference between systems>

[0197] like Fig.13 As shown in the example of the output signal V1B of the first output winding of the second system, due to the magnetic interference between the systems, the output signals V1B and V2B of the two output windings 111B and 112B of the second system are respectively superimposed with the first period component induced by the electromagnetic induction caused by the magnetic flux of the first period TA generated by the excitation of the excitation winding 10B of the first system. Fig.13The upper diagram shows the output signal V1B of the first output winding of the second system, the middle diagram shows the second period component V1B_TB induced by electromagnetic induction caused by the magnetic flux of the excitation winding 10B of the second system included in the output signal V1B of the first output winding of the second system, and the lower diagram shows the first period component V1B_TA induced by the magnetic flux of the excitation winding 10A of the first system included in the output signal V1B of the first output winding of the second system. The output signal V1B of the first output winding of the second system is a signal obtained by summing the second period component V1B_TB and the first period component V1B_TA.

[0198] <First cycle component reduction processing>

[0199] In the present embodiment, the second system reduction processing unit 53B also performs the first period component reduction processing for reducing the components of the first period on the detection values ​​V1B_S and V2B_S of the output signals of the two output windings of the second system.

[0200] In this embodiment, the difference from the first embodiment is that the first period component reduction process is performed based on the principle described below. Fig.13 As shown in the lower part of the figure, the component V1B_TA of the first period of the output signal of the first output winding of the second system undergoes phase reversal at a period that is half a period TA / 2 of the first period plus an integer multiple of the first period TA (for example, half a period TA / 2 of the first period), and the positive and negative signs are reversed.

[0201] Therefore, as the first period component reduction processing, the reduction processing unit 53B of the second system is configured to add the detection values ​​V1B_S and V2B_S of the output signals of the two output windings of the second system detected at the current detection timing to the detection values ​​V1B_Sold and V2B_Sold of the output signals of the two output windings of the second system detected at the detection timing before the second system reduction processing interval ΔT2 of the current detection timing. As shown in the following formula, the second system reduction processing interval ΔT2 is set to an interval obtained by adding an integer multiple of the first period TA to a half period TA / 2 of the first period. Here, X is an integer greater than 0. In the present embodiment, it is set to X=0, and the second system reduction processing interval ΔT2 is set to a half period TA / 2 of the first period.

[0202] ΔT2=TA / 2+TA×X··· (16)

[0203] According to this structure, two components of the first cycle with opposite signs are added, and the two components of the first cycle cancel each other. Therefore, in the detection values ​​V1B_F and V2B_F of the output signals of the two output windings of the second system after addition, the components of the first cycle are reduced. Thus, using the components of the second cycle of the second system with the components of the first cycle of the first system reduced, the abnormality determination of the second system described later can be accurately performed.

[0204] In this embodiment, if Fig.13 As shown, the output signal detection unit 52B of the second system periodically detects the output signals V1B and V2B of the two output windings of the second system at two timings TM1 and TM2 that are symmetrical before and after the reference timing TM0 when the AC voltage VRB of the second period TB applied to the excitation winding 10B of the second system becomes the maximum value or the minimum value.

[0205] The interval between the two symmetrical timings is set to the second system reduction processing interval ΔT2. Therefore, as shown in the following equation, the interval ΔTM12 between the two timings TM1 and TM2 before and after the reference timing TM0 is set to half the second system reduction processing interval ΔT2.

[0206] ΔTM12=ΔT2 / 2··· (17)

[0207] Therefore, the second system reduction processing unit 53B adds the detection values ​​of the output signals of the two output windings of the second system detected at two symmetrical timings TM1 and TM2, and calculates the detection values ​​V1A_F and V2A_F of the output signals of the two output windings of the second system after the first period component reduction processing.

[0208] According to this structure, Fig.13 As shown, the components of the second cycle included in the detection values ​​of the output signals of the two output windings of the second system detected at the two timings have the same phase and the same positive and negative signs, and thus are equal values. In addition, the interval between the two timings TM1 and TM2 is set to the second system reduction processing interval ΔT2, so the components of the first cycle included in the detection values ​​of the output signals of the two output windings of the second system detected at the two timings TM1 and TM2 are inverted in phase and positive and negative signs. Therefore, the detection values ​​V1B_F and V2B_F of the output signals of the two output windings of the second system after these additions are respectively equivalent to twice the values ​​of the components V1B_TB and V2B_TB of the second cycle included in the detection values.

[0209] V1B_F≒2×V1B_TB

[0210] V2B_F≒2×V2B_TB… (18)

[0211] The reduction processing unit 53B of the second system is, for example, Fig.14 The reduction processing unit 53B of the second system includes a first delayer 53B1, which delays the detection value V1B_S of the output signal of the first output winding of the second system by the second system reduction processing interval ΔT2 and then outputs it. The reduction processing unit 53B of the second system adds the detection value V1B_S of the output signal of the first output winding of the second system to the output V1B_Sold of the first delayer 53B1 at the timing TM2 after the reference timing TMO, and calculates the detection value V1B_F of the output signal of the first output winding of the second system after the first period component reduction processing. Similarly, the reduction processing unit 53B of the second system includes a second delayer 53B2, which delays the detection value V2B_S of the output signal of the second output winding of the second system by the second system reduction processing interval ΔT2 and then outputs it. The reduction processing unit 53B of the second system adds the detection value V2B_S of the output signal of the second output winding of the second system to the output V2B_Sold of the second delayer 53B2 at the timing TM2 after the reference timing TMO, and calculates the detection value V2B_F of the output signal of the second output winding of the second system after the first period component reduction processing.

[0212] In this embodiment, as shown in the following formula, the second period TB is set to twice the first period TA. In addition, the second system reduction processing interval ΔT2 is set to half the first period TA / 2. Therefore, the interval ΔTM12 between the two timings before and after the reference timing TM0 is set to one quarter of the first period, that is, TA / 4.

[0213] TB=TA×2

[0214] ΔT2=TA / 2

[0215] ΔTM12=TA / 4··· (19)

[0216] In addition, the output signal detection unit 52B of the second system detects the output signals V1B and V2B of the two output windings of the second system every quarter cycle TB / 4 of the second cycle, and each detection timing is set to be symmetrical relative to the reference timing TM0 when the AC voltage VRB of the second cycle TB becomes the maximum or minimum value.

[0217] <Abnormality determination of the second system>

[0218] The output signal detection unit 52B of the second system periodically detects the output signals V1B and V2B of the two output windings 111B and 112B of the second system at a detection period for abnormality determination of the second system set to a period less than half of the second period TB. Fig.13 As shown, the second system output signal detection unit 52B detects the output signals V1B_S and V2B_S of the two output windings of the second system at the timing ( TM1 , TM2 ) of every quarter cycle of the second cycle TB.

[0219] Then, the second system reduction processing unit 53B calculates the two second system output signals V1B_F and V2B_F after the first period component reduction processing as described above at the timing TM2 after two timings every half period TB / 2 of the second period.

[0220] The second system DC extraction processing unit 55B performs DC extraction processing to reduce the components of the second period TB on the two output signals V1B_F and V2B_F of the second system after the first period component reduction processing, and calculates DC values ​​V1B_DC and V2B_DC of the two output signals of the second system.

[0221] In this embodiment, the DC extraction processing unit 55B of the second system performs moving average processing during the second period TB on the two output signals V1B_F and V2B_F of the second system after the first period component reduction processing, and calculates the DC values ​​V1B_DC and V2B_DC of the two output signals of the second system. As shown in the following formula, the DC extraction processing unit 55B of the second system calculates the average value of the two output signals V1B_F and V2B_F of the second system after the first period component reduction processing calculated at the timing TM2 after this time and the two output signals V1B_F_old and V2B_F_old of the second system after the first period component reduction processing calculated at the timing TM2 before the half period TB / 2 of the second period as the DC values ​​V1B_DC and V2B_DC of the two output signals of the second system.

[0222] V1B_DC={V1B_F+V1B_F_old} / 2

[0223] V2B_DC={V2B_F+V2B_F_old} / 2… (20)

[0224] As explained using equation (18), the two output signals V1B_F and V2B_F of the second system after the first period component reduction process are equivalent to twice the values ​​of the components V1B_TB and V2B_TB of the second period. Fig.13As can be seen from the behavior of the component V1B_TB of the second cycle shown, the phases of the two output signals V1B_F and V2B_F of the second system after the first cycle component reduction processing calculated at the timing TM2 after this time are reversed from the two output signals V1B_F_old and V2B_F_old of the second system after the first cycle component reduction processing calculated at the timing TM2 before the half cycle TB / 2 of the second cycle. Therefore, by calculating the average value of the two, the vibration center value of the components V1B_TB and V2B_TB of the second cycle can be calculated.

[0225] Alternatively, the DC extraction processing unit 55B of the second system can perform moving average processing on the two output signals V1B_F and V2B_F of the second system after the first periodic component reduction processing over a period of a natural number multiple of more than 2 times the second period TB, and calculate the DC values ​​V1B_DC and V2B_DC of the two output signals of the second system.

[0226] Alternatively, the DC extraction processing unit 55B of the second system may perform a band-stop filtering process on the two output signals V1B_F and V2B_F of the second system after the first period component reduction process to reduce the frequency band components including the frequency of the second period TB, and calculate the DC values ​​V1B_DC and V2B_DC of the two output signals of the second system. Alternatively, the DC extraction processing unit 55B of the second system may perform a low-pass filtering process with a cutoff frequency smaller than the frequency of the second period TB on the two output signals V1B_F and V2B_F of the second system after the first period component reduction process, and calculate the DC values ​​V1B_DC and V2B_DC of the two output signals of the second system.

[0227] On the other hand, unlike the present embodiment, in the case where the first period component reduction process is not performed and the first period component is superimposed on the two output signals of the second system, as shown in FIG. Fig.13 As shown, the component T1B_TA of the first period becomes the same value every half period TB / 2 of the second period. Therefore, the component of the first period TA is superimposed on the DC value of the two output signals of the second system, resulting in a deviation, and the vibration center values ​​of the components V1B_TB and V2B_TB of the second period cannot be accurately calculated.

[0228] 3. Implementation Method 3

[0229] Next, a resolver abnormality detection device according to Embodiment 3 is described. Description of the same components as those in Embodiment 1 or 2 is omitted. The basic structure of the resolver abnormality detection device according to this embodiment is the same as that in Embodiment 1, but the structure of the resolver 1 is different from that in Embodiment 1 or 2. Fig.15It is a schematic structural diagram of the angle detection device involved in this embodiment.

[0230] As in Embodiment 1, resolver 1 includes a first system field winding 10A, two first system output windings 111A and 112A, a second system field winding 10B, and two second system output windings 111B and 112B. Magnetic interference occurs between the first system winding and the second system winding.

[0231] However, in this embodiment, unlike Embodiments 1 and 2, Fig.16 As shown in the schematic diagram of the rotary transformer 1, the excitation winding 10A of the first system and the two output windings 111A and 112A of the first system are wound on the stator 13A of the first system, and the excitation winding 10B of the second system and the two output windings 111B and 112B of the second system are wound on the stator 13B of the second system. The stator 13A of the first system and the stator 13B of the second system are arranged adjacent to each other in the axial direction, and magnetic interference is generated between the windings of the first system and the windings of the second system. In addition, Fig.16 In the illustration, the teeth and windings of the stator 13A of the first system and the teeth and windings of the stator 13B of the second system are omitted.

[0232] The stator 13A of the first system and the stator 13B of the second system are coaxially arranged adjacent to each other in the axial direction, and the integrally formed rotor 14 is arranged radially inside the stator 13A of the first system and the stator 13B of the second system. The rotor 14 includes a plurality of protrusions uniformly arranged circumferentially on the outer periphery. In the present embodiment, the portion of the rotor located radially inside the stator 13A of the first system and the portion of the rotor located radially inside the stator 13B of the second system have the same shape of protrusions. In addition, the portion of the rotor located radially inside the stator 13A of the first system and the portion of the rotor located radially inside the stator 13B of the second system may have protrusions of different shapes and numbers, or may be in the form of being connected as a single body so as to rotate as a whole.

[0233] The stator 13A of the first system has a plurality of teeth uniformly arranged in the circumferential direction. The first output winding 111A of the first system and the second output winding 112A of the first system are dispersedly wound on the teeth of the stator 13A of the first system so that the amplitudes of their induced AC voltages differ from each other by 90 degrees in electrical angle. The excitation winding 10A of the first system is dispersedly wound on the teeth of the stator 13A of the first system. The stator 13B of the second system has a plurality of teeth uniformly arranged in the circumferential direction. The first output winding 111B of the second system and the second output winding 112B of the second system are dispersedly wound on the teeth of the stator 13B of the second system so that the amplitudes of their induced AC voltages differ from each other by 90 degrees in electrical angle. The excitation winding 10B of the second system is dispersedly wound on the teeth of the stator 13B of the second system. In addition, the number of teeth of the stator 13A of the first system and the number of teeth of the stator 13B of the second system may be the same number or different numbers.

[0234] Even with such a structure of the rotary transformer 1, by performing the same processing as the control device 50 of embodiment 1 or 2, even if magnetic interference between the systems occurs, the first angle θ1 and the second angle θ2, as well as the DC values ​​V1A_DC and V2A_DC of the two output signals of the first system and the DC values ​​V1B_DC and V2B_DC of the two output signals of the second system can be accurately detected.

[0235] 4. Other Implementation Methods

[0236] Finally, other embodiments of the present application are described. In addition, the structures of the embodiments described below are not limited to being applied separately, and can be combined with the structures of other embodiments for application as long as no contradiction occurs.

[0237] (1) The first system and the second system can be interchanged. That is, the first system in each of the above embodiments can be replaced by the second system, and the second system in each of the above embodiments can be replaced by the first system.

[0238] (2) In the above-mentioned embodiments, the following case is described as an example, that is, as the second period component reduction processing for reducing the second period component included in the detection value of the output signal of the two output windings of the first system, the reduction processing unit 53A of the first system performs an addition processing of adding the current detection value to the detection value before the first system reduction processing interval ΔT1, and as the first period component reduction processing for reducing the first period component included in the detection value of the output signal of the two output windings of the second system, the reduction processing unit 53B of the second system performs a subtraction processing of subtracting or adding the current detection value to the detection value before the second system reduction processing interval ΔT2. However, the embodiment of the present application is not limited to this. That is, as the second period component reduction processing, the reduction processing unit 53A of the first system may also be configured to perform a band reduction filtering processing such as a high-pass filtering processing or a band-stop filtering processing to reduce the second period component. As the first period component reduction processing, the reduction processing unit 53B of the second system may also be configured to perform a band reduction filtering processing such as a low-pass filtering processing or a band-stop filtering processing to reduce the first period component.

[0239] (3) In each of the above-mentioned embodiments, the case where the processing units 51A to 56A of the first system and the processing units 51B to 56B of the second system are provided in one control device 50 is described as an example. However, the embodiments of the present application are not limited to this. That is, the processing units 51A to 56A of the first system may be provided in the control device of the first system, the processing units 51B to 56B of the second system may be provided in the control device of the second system, and the processing units 51A to 56B of the first system and the second system may be provided in a dispersed manner in a plurality of control devices.

[0240] (4) In the above-mentioned embodiments, the following case is described as an example, that is, the output signal detection unit 52A of the first system detects the output signals V1A and V2A of the two output windings of the first system every first cycle TA when the excitation AC voltage VRA becomes the maximum value. However, the embodiments of the present application are not limited to this. That is, the output signal detection unit 52A of the first system may detect the output signals V1A and V2A of the two output windings of the first system every first cycle TA when the excitation AC voltage VRA becomes the minimum value, and as described above, may detect every first cycle TA when the AC voltage VRA becomes a value other than the maximum value and the minimum value. Alternatively, the output signal detection unit 52A of the first system may detect every half cycle TA / 2 of the first cycle when the excitation AC voltage VRA becomes the maximum value or the minimum value. Alternatively, the output signal detection unit 52A of the first system may detect the output signals V1A and V2A of the two output windings of the first system every cycle different from the first cycle TA and the half cycle TA / 2 of the first cycle (for example, a cycle obtained by dividing the first system reduction processing interval ΔT1 by an integer greater than 1). In these cases, the first delay device 53A1 and the second delay device 53A2 of the first system reduction processing section 53A delay the input signal by the first system reduction processing interval ΔT1 and output the delayed signal.

[0241] (5) In the above-mentioned first embodiment, the following case is described as an example, that is, the output signal detection unit 52B of the second system detects the output signals V1B and V2B of the two output windings of the second system every half cycle TB / 2 of the second cycle in which the excitation AC voltage VRB reaches the maximum value or the minimum value. However, the embodiment of the present application is not limited to this. That is, as described above, the output signal detection unit 52B of the second system may detect every half cycle TB / 2 of the second cycle in which the excitation AC voltage VRB reaches a value other than the maximum value and the minimum value. Alternatively, the output signal detection unit 52B of the second system may detect the output signals V1B and V2B of the two output windings of the second system every cycle different from the half cycle TB / 2 of the second cycle (for example, a cycle obtained by dividing the second system reduction processing interval ΔT2 by an integer greater than 1). In this case, the first delay unit 53B1 and the second delay unit 53B2 of the reduction processing unit 53B of the second system also delay the input signal by the second system reduction processing interval ΔT2 before outputting it.

[0242] (6) In the above-mentioned second embodiment, the following case is described as an example, that is, the output signal detection unit 52B of the second system detects the output signals V1B and V2B of the two output windings of the second system every quarter period TB / 4 of the second cycle, and each detection timing is set to be symmetrical with respect to the reference timing TM0 when the AC voltage VRB of the second cycle TB becomes the maximum value or the minimum value. However, the embodiment of the present application is not limited to this. That is, the output signal detection unit 52B of the second system may periodically detect the output signals V1B and V2B of the two output windings of the second system at two timings that are symmetrical with respect to the reference timing TM0 when the excitation AC voltage VRB becomes the maximum value, or the output signal detection unit 52B of the second system may periodically detect the output signals V1B and V2B of the two output windings of the second system at two timings that are symmetrical with respect to the reference timing TM0 when the excitation AC voltage VRB becomes the minimum value. In addition, if the interval between the two symmetrical timings is set to the second system reduction processing interval ΔT2, it may also be set to an interval other than TB / 4, which is one quarter of the second cycle. In these cases, the first delay 53B1 and the second delay 53B2 of the reduction processing unit 53B of the second system delay the input signal by the second system reduction processing interval ΔT2 and then output it. The reduction processing unit 53B of the second system can also perform addition processing at the timing TM2 after the reference timing TM0, and calculate the detection values ​​V1B_F and V2B_F of the output signals of the two output windings of the second system after addition.

[0243] (7) The angle detection device of the present application can be used as an angle detection device of an electric motor having two sets of three-phase windings and inverters. Such a dual-system electric motor is included in an electric power steering device, for example. The structure of the first system of the angle detection device of the present application is allocated to the control system of the first set of three-phase windings and inverters, and the first angle θ1 is used. The structure of the second system of the angle detection device of the present application is allocated to the control system of the second set of three-phase windings and inverters, and the second angle θ1 is used. Therefore, when an abnormality is detected in the first system of the angle detection device, the control of the three-phase windings and inverter of the first group is stopped, and when an abnormality is detected in the second system of the angle detection device, the control of the three-phase windings and inverter of the second group is stopped. In the angle detection device of the present application, it is not necessary to synchronize the first system and the second system, so it can be configured such that the first control device (CPU) controls the first set of three-phase windings and inverters and the first system of the angle detection device, and the second control device (CPU) controls the second set of three-phase windings and inverters and the second system of the angle detection device. Therefore, the system including the angle detection device is redundant, which can improve reliability.

[0244] Although the present application describes various exemplary embodiments and examples, the various features, methods and functions described in one or more embodiments are not limited to the application of specific embodiments and can be applied to the embodiments individually or in various combinations. Therefore, it can be considered that countless variations that are not illustrated are also included in the technical scope disclosed in the present application specification. For example, it is set to include the case where at least one constituent element is deformed, added or omitted, and the case where at least one constituent element is extracted and combined with constituent elements of other embodiments.

[0245] Description of symbols

[0246] 1 rotary transformer, 10A excitation winding of the first system, 10B excitation winding of the second system, 111A, 112A two output windings of the first system, 111B, 112B two output windings of the second system, 51A excitation section of the first system, 52A output signal detection section of the first system, 53A reduction processing section of the first system, 54A angle calculation section of the first system, 55A DC extraction processing section of the first system, 56A abnormality detection section of the first system, 51B excitation section of the second system, 52B output signal detection section of the second system, 53B reduction processing section of the second system, 54B angle calculation section of the second system, 55B DC extraction processing section of the second system, 56B abnormality detection section of the second system, TA first cycle, TB second cycle, △T1 first system reduction processing interval, △T2 second system reduction processing interval, V1A_S, V2A_S detection values ​​of two output signals of the first system, V1A_F , V2A_F are the detection values ​​of the two output signals of the first system after the second periodic component is reduced, V1A_DC and V2A_DC are the DC values ​​of the two output signals of the first system, V1A_TA and V2A_TA are the first periodic components included in the output signals of the two output windings of the first system, V1A_TB and V2A_TB are the second periodic components included in the output signals of the two output windings of the first system, V1B_S and V2B_S are the detection values ​​of the two output signals of the second system, V1B_F and V2B_F are the detection values ​​of the two output signals of the second system after the first periodic component is reduced, V1B_DC and V2B_DC are the DC values ​​of the two output signals of the second system, V1B_TA and V2B_TA are the first periodic components included in the output signals of the two output windings of the second system, and V1B_TB and V2B_TB are the second periodic components included in the output signals of the two output windings of the second system.

Claims

1. A rotary transformer abnormality detection device, characterized in that: include: A rotary transformer having an excitation winding of a first system, two output windings of the first system, an excitation winding of a second system, and two output windings of the second system, and magnetic interference is generated between the first system and the second system; an excitation part of a first system, the excitation part of the first system applying an AC voltage of a first period to an excitation winding of the first system; an excitation section of a second system, the excitation section of the second system applying an AC voltage of a second cycle different from the first cycle to an excitation winding of the second system; an output signal detection unit of a first system, the output signal detection unit of the first system detecting output signals of two output windings of the first system at a period that is less than half of the first period; a first system reduction processing unit, the first system reduction processing unit performing a second period component reduction process on the detection values ​​of the output signals of the two output windings of the first system to reduce the components of the second period; a DC extraction processing unit of the first system, which performs a DC extraction process to reduce the components of the first period on the detected values ​​of the output signals of the two output windings of the first system after the second period component reduction process, and calculates the DC values ​​of the two output signals of the first system; and The abnormality detection unit of the first system determines the abnormality of the first system based on whether the DC values ​​of the two output signals of the first system are within a preset normal range of the first system.

2. The abnormality detection device for a rotary transformer according to claim 1, characterized in that: When the DC values ​​of the two output signals of the first system are out of the normal range of the first system continuously for more than a preset number of abnormality determination times, the abnormality detection unit of the first system determines that an abnormality has occurred in the first system.

3. The abnormality detection device for a rotary transformer according to claim 1 or 2, characterized in that: The DC extraction processing unit of the first system performs moving average processing on the detection values ​​of the output signals of the two output windings of the first system after the second period component reduction processing over a period of natural number multiples of the first period, and calculates the DC values ​​of the two output signals of the first system.

4. The abnormality detection device for a rotary transformer according to claim 1 or 2, characterized in that: The output signal detection unit of the first system detects output signals of two output windings of the first system at a detection timing of every half cycle of the first cycle when the AC voltage of the first cycle applied to the excitation winding of the first system reaches a maximum value or a minimum value, The DC extraction processing unit of the first system calculates the average value of the detection value of the output signal of the two output windings of the first system after the second periodic component reduction processing calculated at this detection timing and the detection value of the output signal of the two output windings of the first system after the second periodic component reduction processing calculated at the previous detection timing as the DC value of the two output signals of the first system.

5. The abnormality detection device for a rotary transformer according to claim 1 or 2, characterized in that: The second period is set to be longer than the first period, As the second period component reduction processing, the reduction processing unit of the first system adds the detection value of the output signal of the two output windings of the first system detected at the current detection timing and the detection value of the output signal of the two output windings of the first system detected at the detection timing before the first system reduction processing interval of the current detection timing, and the first system reduction processing interval is set to TB / 2+TB×M (M is an integer greater than 0), wherein the second period is set to TB.

6. The abnormality detection device for a rotary transformer according to claim 5, characterized in that: The second period is set to TA×2×N (N is an integer greater than or equal to 1), where the first period is set to TA.

7. The abnormality detection device for a rotary transformer according to claim 1 or 2, characterized in that: include: an output signal detection unit of a second system, the output signal detection unit of the second system detecting output signals of two output windings of the second system at a period that is less than half of the second period; a reduction processing unit of a second system, the reduction processing unit of the second system performing a first period component reduction process on the detection values ​​of the output signals of the two output windings of the second system to reduce the components of the first period; a DC extraction processing unit of the second system, which performs a DC extraction process to reduce the components of the second period on the detected values ​​of the output signals of the two output windings of the second system after the first period component reduction process, and calculates the DC values ​​of the two output signals of the second system; as well as The abnormality detection unit of the second system determines the abnormality of the second system based on whether the DC values ​​of the two output signals of the second system are within a preset normal range of the second system.

8. The abnormality detection device for a rotary transformer according to claim 7, characterized in that: When the DC values ​​of the two output signals of the second system are out of the normal range of the second system continuously for more than a preset number of abnormality determination times, the abnormality detection unit of the second system determines that an abnormality has occurred in the second system.

9. The abnormality detection device for a rotary transformer according to claim 7, characterized in that: The DC extraction processing unit of the second system performs moving average processing on the detection values ​​of the output signals of the two output windings of the second system after the first period component reduction processing over a period of natural number multiples of the second period, and calculates the DC values ​​of the two output signals of the second system.

10. The abnormality detection device for a rotary transformer according to claim 7, characterized in that: The output signal detection unit of the second system detects the output signals of the two output windings of the second system at the detection timing of every half cycle of the second cycle when the AC voltage of the second cycle applied to the excitation winding of the second system reaches the maximum value or the minimum value, The DC extraction processing unit of the second system calculates the average value of the detection value of the output signal of the two output windings of the second system after the first periodic component reduction processing calculated at the current detection timing and the detection value of the output signal of the two output windings of the second system after the first periodic component reduction processing calculated at the previous detection timing as the DC value of the two output signals of the second system.

11. The abnormality detection device for a rotary transformer according to claim 7, characterized in that: As the first period component reduction processing, the reduction processing unit of the second system performs a subtraction processing to calculate the difference between the detection value of the output signal of the two output windings of the second system detected at the current detection timing and the detection value of the output signal of the two output windings of the second system detected at the detection timing before the second system reduction processing interval of the current detection timing, and the second system reduction processing interval is set to TA×P (P is an integer greater than 1), wherein the first period is set to TA.

12. The abnormality detection device for a rotary transformer according to claim 11, characterized in that: The second period is set to TA×2×N (N is an integer greater than 1), wherein the first period is set to TA, The second system reduction processing interval is set to TB / 2+TB×L (M is an integer greater than or equal to 0), where the second period is set to TB.

13. The abnormality detection device for a rotary transformer according to claim 7, characterized in that: As the first period component reduction processing, the reduction processing unit of the second system adds the output signals of the two output windings of the second system detected at the current detection timing and the output signals of the two output windings of the second system detected at the detection timing before the second system reduction processing interval of the current detection timing, The second system reduction processing interval is set to TA / 2+TA×X (X is an integer greater than or equal to 0), where the first period is set to TA.

14. The abnormality detection device for a rotary transformer according to claim 13, characterized in that: The output signal detection unit of the second system periodically detects the output signals of the two output windings of the second system at two timings that are symmetrical with respect to a reference timing at which the AC voltage of the second period applied to the excitation winding of the second system reaches a maximum value or a minimum value, The interval between the two timings is set to the second system reduction processing interval, The reduction processing unit of the second system adds the detection values ​​of the output signals of the two output windings of the second system detected at the two timings at a timing after the two timings.

15. The abnormality detection device for a rotary transformer according to claim 14, characterized in that: The output signal detection unit of the second system detects the output signals of the two output windings of the second system at a detection timing of every quarter of the second cycle. The DC extraction processing unit of the second system calculates the average value of the detection value of the output signal of the two output windings of the second system after the first periodic component reduction processing calculated at the timing after this time, and the detection value of the output signal of the two output windings of the second system after the first periodic component reduction processing calculated at the timing after the previous time, as the DC value of the two output signals of the second system.

16. The abnormality detection device for a rotary transformer according to claim 1 or 2, characterized in that: The excitation winding of the first system, the two output windings of the first system, the excitation winding of the second system, and the two output windings of the second system are wound on the same stator.

17. The abnormality detection device for a rotary transformer according to claim 1 or 2, characterized in that: The excitation winding of the first system and the two output windings of the first system are wound on the stator of the first system, and the excitation winding of the second system and the two output windings of the second system are wound on the stator of the second system axially adjacent to the stator of the first system.

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