JP4364569B2 - Resolver signal processing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resolver signal processing apparatus.
[0002]
[Prior art]
A so-called resolver has an excitation coil and a detection coil, applies an excitation signal to the excitation coil, detects a voltage generated in the detection coil, and based on the detected signal, the angular position between the excitation coil and the detection coil. Is detected. As this resolver, a so-called absolute type is known in which a position is detected by a coordinate value of one coordinate system and converted into a position signal.
The absolute resolver has a backup function that detects and stores the amount of rotation even during a power failure when the main power supply is not supplied to the signal processing circuit of the resolver. In other words, if the resolver rotates for some reason at the time of a power failure, the absolute coordinate value cannot be recognized when the main power is turned on unless the rotation amount at the time of the power failure is detected and stored. .
For example, Patent Documents 1 to 4 disclose a resolver having a backup function at the time of a power failure.
[0003]
[Patent Document 1]
JP 05-5629 A
[Patent Document 2]
Patent No. 3248201
[Patent Document 3]
Japanese Patent Laid-Open No. 06-331386
[Patent Document 4]
Japanese Patent No. 3328999
[0004]
[Problems to be solved by the invention]
Incidentally, in the resolver position detector, the resolver and a drive circuit for driving the resolver are connected by a conductive wire and a connector. For example, if the path connecting the resolver and the drive circuit is interrupted when the backup function is operating during a power failure, the amount of rotation during the power failure may not be accurately detected.
For this reason, it is important to detect whether the path connecting the resolver and the drive circuit is interrupted during a power failure.
As a method for detecting whether or not the path connecting the resolver and the drive circuit is blocked, for example, applying a photocoupler to the drive circuit can be considered. However, if the length of the conductive wire connecting the resolver and the drive circuit is long, the impedance of the conductive wire increases, and even if the conductive wire is disconnected or the connector is dropped, a current flows through the photocoupler, There is a possibility that the interruption of the path connecting the drive circuit cannot be detected reliably.
In addition, although it is possible to provide a circuit for detecting disconnection of a conductive wire or disconnection of a connector on the drive circuit side, there is a problem that power consumption during backup is increased.
[0005]
The present invention has been made in view of the above-described problems, and the object of the present invention is to reliably detect the interruption of the path connecting the resolver and the drive circuit that drives the resolver during backup, and during backup. An object of the present invention is to provide a resolver signal processing device with reduced power consumption.
[0006]
[Means for Solving the Problems]
A resolver signal processing device according to the present invention is a resolver signal processing device that performs signal processing of a resolver having first and second coils that can rotate relative to each other, and is connected to the resolver and is supplied with power from a main power source. The relative rotation amount of the first and second coils generated while the power is supplied from the backup power source when the power is supplied from the backup power source and the first power source is supplied from the backup power source is calculated. Or having a backup circuit that detects based on a detection signal detected by the second coil, and the backup circuit is based on the detection signal whether or not the connection path between the resolver and the backup circuit is interrupted It has a disconnection detection means for detecting.
[0007]
Preferably, the backup circuit includes pulse generation means for supplying a pulsed excitation signal having a predetermined cycle to one of the first and second coils, and a voltage generated at the other of the first and second coils. Is differentially input with a reference voltage, a differential input amplifier that amplifies the differential input amplifier, a comparator that compares the output voltage of the differential input amplifier with a comparator voltage different from the reference voltage, and a comparator signal of the comparator A circuit for detecting and storing the relative rotation amount from the first phase signal and the second phase signal obtained by latching based on the excitation timing of the excitation signal, and the disconnection detecting means includes: It has a disconnection detection circuit for generating a detection signal for detecting whether or not the connection path is blocked based on the comparator signal.
[0008]
More preferably, the comparator voltage is such that the comparator comparator signal generates the pulse regardless of the relative rotational position of the first and second coils when the connection path is not interrupted. It is set to a value that changes according to the generation period of the excitation signal of the means.
[0009]
More preferably, the disconnection detection circuit includes a first detection circuit that detects presence / absence of a change in the comparator signal for each generation period of the excitation signal, and a plurality of detection results of the first detection circuit. And a second detection circuit that generates a detection signal that is held over a generation cycle and detects whether or not the connection path is blocked based on the detection results in a plurality of the generation cycles.
[0010]
In the present invention, the backup circuit detects the relative rotation amounts of the first and second coils during a power failure when the main power supply is shut off. At this time, the disconnection detection means detects the disconnection of the connection path between the resolver and the backup circuit using the detection signal of the first or second coil for detecting the relative rotation amount in the backup circuit.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First embodiment
FIG. 1 is a functional block diagram showing a configuration of a resolver signal processing device according to an embodiment of the present invention.
The resolver signal processing device 1 includes a backup circuit 2 and an angle conversion circuit 12.
The backup circuit 2 is electrically connected to the resolver 120 by a cable 30. The angle conversion circuit 12 is electrically connected to the coil 122 of the resolver 120.
[0012]
The backup circuit 2 includes a pulse generation circuit 3, a non-power failure excitation data holding unit 4, a power failure excitation data holding unit 5, a power failure detection circuit 6, a differential input amplifier 7, a comparator 8, and a rotation amount detection. Part 9, clock generation circuit 10, and disconnection detection circuit 11.
[0013]
The resolver 120 is the resolver of the present invention, the pulse generating circuit 3 is the pulse generating means of the present invention, the differential input amplifier 7 is the differential input amplifier of the present invention, the comparator 8 is the comparator of the present invention, and the rotation amount detection unit 9 is the present invention. The rotation amount detection means, the disconnection detection circuit 11 is an embodiment of the disconnection detection circuit of the present invention, the main power supply 25 is the main power supply of the present invention, and the backup power supply 21 is an embodiment of the backup power supply of the present invention.
[0014]
The resolver 120 includes two-phase excitation coils 121A and 121B and a one-phase detection coil 122. Excitation coils 121A and 121B and detection coil 122 are one embodiment of the first and second coils of the present invention.
The excitation coils 121A and 121B are coils provided on the stator side (not shown) of the resolver 120, and the excitation coils 121A and 121B are arranged at positions where the phases are electrically different by 90 °.
The exciting coil 121A is connected to the output ends S1 and S3 of the pulse generating circuit 3. The exciting coil 121B is connected to the output ends S2 and S4 of the pulse generating circuit 3.
[0015]
The detection coil 122 is a coil provided on the rotor side (not shown) of the resolver 120. Note that the mechanical rotation angle from the reference position of the rotor is θ.
When an excitation signal is applied to the excitation coils 121A and 121B, a voltage corresponding to the rotation angle θ is generated between R1 and R2 of the detection coil 122.
[0016]
In the angle conversion circuit 11, both ends of the detection coil 122 are electrically connected, and a voltage generated between the R1 terminal side and the R2 terminal side of the detection coil 122 is input. When a voltage corresponding to the rotation angle θ is input, the angle conversion circuit 11 generates a rotation angle signal RD corresponding to the rotation angle θ and outputs the rotation angle signal RD to the controller 100. Thus, the controller 100 can recognize the rotation angle θ.
The angle conversion circuit 11 operates when power is supplied from the main power supply 25. Therefore, when the power supply from the main power supply 25 is cut off, the angle conversion circuit 11 does not operate.
[0017]
The main power supply 25 supplies power to the backup circuit 2, the angle conversion circuit 12, and the controller 100.
The control power supply 140 supplies power to the main power supply 25. Therefore, when the control power supply 140 is turned off, the power supply from the main power supply 25 to the backup circuit 2, the angle conversion circuit 12, and the controller 100 is cut off.
The control power supply power failure detection circuit 110 detects that the control power supply 140 is turned off, and outputs this detection signal 110 s to the controller 100.
[0018]
The power supply switching circuit 130 is a circuit that switches the power supply to the backup circuit 2 between the main power supply 25 and the backup power supply 21. Specifically, when power supply from the main power supply 25 to the backup circuit 2 is cut off, the power supply switching circuit 130 supplies power from the backup power supply 21 to the backup circuit 2. Further, when the power supply from the main power supply 25 is resumed, the power supply switching circuit 130 cuts off the power supply from the backup power supply 21 to the backup circuit 2 and supplies the backup circuit 2 with the power from the main power supply 25.
The backup circuit 2 is a circuit that is operated by the backup power supply 21 when the supply of power from the main power supply 25 of the power supply unit 21 is cut off.
[0019]
When receiving power from the main power supply 25, the pulse generation circuit 3 supplies a pulsed excitation signal to the excitation coils 121A and 121B based on the excitation data stored in the excitation data holding unit 4 during non-power failure. To do.
Further, when the excitation switching signal 100as is input from the controller 100, the pulse generation circuit 3 generates a pulsed excitation signal having a predetermined cycle based on the excitation data stored in the excitation data holding unit 5 at the time of power failure. , 121B. Furthermore, the pulse generation circuit 3 receives the detection signal 6s from the power failure detection circuit 6 while outputting a pulsed excitation signal having a predetermined cycle based on the excitation data stored in the excitation data holding unit 5 during a power failure. Then, the excitation cycle is extended by a predetermined time, for example, 16 times, and an excitation signal is output.
[0020]
The non-power failure excitation data holding unit 4 holds excitation data of an excitation signal to be output from the pulse generation circuit 3 when the pulse generation circuit 3 is supplied with power from the main power supply 25. This excitation data is an embodiment of the first excitation data of the present invention.
The excitation data holding unit 5 at the time of power failure excites an excitation signal to be output from the pulse generation circuit 3 when power supply from the main power supply 25 to the pulse generation circuit 3 is cut off and power is received from the backup power supply 21. Holds data. This excitation data is an embodiment of the second excitation data of the present invention.
[0021]
The power failure detection circuit 6 detects that power supply from the main power supply 25 to the backup circuit 2 has been cut off. When the power failure detection circuit 6 detects that the power supply from the main power supply 25 to the backup circuit 2 is cut off, the power failure detection circuit 6 outputs a detection signal 6 s to the pulse generation circuit 3.
[0022]
Here, FIG. 2 shows an example of the excitation signal generated in the pulse generation circuit 3 based on the data stored in the non-power failure excitation data holding unit 4.
The pulse generation circuit 3 has VA = V₀ sinω₀ A pulsed excitation signal Vpa obtained by pulse width modulation of the sine wave signal represented by t is output from S1 and S3, and the excitation signal Vpa is applied to the excitation coil 121A.
In addition, the pulse generation circuit 3 is similar to the excitation signal Vpa in that VB = V₀ cosω₀ A pulsed excitation signal Vpb obtained by pulse width modulation of the cosine wave signal represented by t is output from S2 and S4, and this excitation signal Vpb is applied to the excitation coil 121B.
The carrier frequency of the pulse width modulated excitation signals Vpa and Vpb is, for example, a high frequency of several tens of kHz.
[0023]
When the excitation signals Vpa and Vpb are applied to the excitation coils 121A and 121B, e = kV is applied to the detection coil 122.₀ sin (ω₀ A voltage represented by t + θ) is induced. The induced voltage e is input to the angle conversion circuit 12, and the angle conversion circuit 12 detects the rotation angle θ based on the induced voltage e. The rotation angle θ is output from the angle conversion circuit 12 to the controller 100 as A-phase and B-phase pulse signals. The controller 100 can obtain the rotation angle θ as digital data by counting the rising and falling edges of the A-phase and B-phase pulse signals.
[0024]
FIG. 3 shows an example of the excitation signal generated in the pulse generation circuit 3 based on the data stored in the excitation data holding unit 5 at the time of power failure.
When the pulse generation circuit 3 receives the excitation switching signal 100as from the controller 100, as shown in FIG.₂ Excitation signals Pa and Pb of a predetermined period T₁ And output to the exciting coils 121A and 121B, respectively. Further, between the excitation signal Pa and the excitation signal Pb, the phase T_Three Exists.
[0025]
When the pulse generation circuit 3 receives the excitation switching signal 100as and then receives the detection signal 6s from the power failure detection circuit 6, after a predetermined time has elapsed since the detection signal 6s was input, for example, after 9 seconds have elapsed, Period T₁ Excitation signals Pa and Pb, which are multiplied by 16 are generated.
When the detection signal 6 s is input from the power failure detection circuit 6 and a predetermined time has elapsed, the backup circuit 2 is supplied with power from the backup power source 21.
Specifically, the extended period T₁ Is, for example, 125 μs. The frequencies of the excitation signals Pa and Pb are about 4 kHz, which is lower than the carrier frequency when the pulse generation circuit 3 is supplied with power from the main power supply 25. By suppressing the frequencies of the excitation signals Pa and Pb, it is possible to suppress power consumption.
Pulse width T₂ Is, for example, about 7 μs. Phase T_Three Is, for example, about 60 μs.
[0026]
For example, when the resolver 120 is attached to a rotation shaft to be controlled such as a motor, the controller 100 obtains information on the rotation angle θ of the rotation shaft from the resolver 120 (angle conversion circuit 12), and information on the rotation angle θ. The controlled object is controlled based on the above.
The controller 100 operates by receiving power from the main power supply 25.
When the controller 100 receives the detection signal 110 s from the control power failure detection circuit 110, the controller 100 reads the angle of the resolver 120 from the angle conversion circuit 12, backs up the absolute value coordinates, and then sends an excitation switching signal to the pulse generation circuit 3. 100as is output. The excitation switching signal 100as is a signal for determining data to be read by the pulse generation circuit 3 among the data stored in the non-power failure excitation data holding unit 4 and the power failure excitation data holding unit 5.
[0027]
The differential input amplifier 7 differentially inputs the induced voltage generated in the detection coil 122 in accordance with the excitation signals Pa and Pb as a reference voltage, and amplifies it. Amplification using the differential input amplifier 7 has an effect of removing common mode noise such as hum particularly when the cable 30 is long.
[0028]
The comparator 8 compares the output voltage of the differential input amplifier 7 with a comparator voltage different from the reference voltage described above, and outputs a comparison signal to the rotation amount detection unit 9.
The rotation amount detection unit 9 latches the comparator signal from the comparator 8 at a latch timing based on the excitation timing of the excitation signal Pa and the excitation signal Pb, for example. Then, the rotation amount of the rotor with respect to the stator of the resolver 120 is detected from the obtained A-phase signal and B-phase signal, and this is stored.
[0029]
FIG. 4 shows an example of a circuit of the differential input amplifier 7 and the comparator 8.
As shown in FIG. 4, the differential input amplifier 7 includes resistors R1, R2, and R3 and an operational amplifier 200. The comparator 8 includes resistors R4, R5, R6 and an operational amplifier 201.
The end of the detection coil 122 is connected to the positive input and the negative input of the operational amplifier 200 via a resistor R2. The operational amplifier 200 amplifies the voltage difference between the positive input and the negative input.
The positive input of the operational amplifier 200 is connected to the supply line of the reference voltage Vb via the resistor R3.
The output of the operational amplifier 200 is fed back to the negative input of the operational amplifier 200 through the resistor R3.
The resistor R1 is connected to the detection coil 122 in parallel.
[0030]
The output of the operational amplifier 200 is connected to the negative input of the operational amplifier 201. The output of the operational amplifier 201 is fed back to the positive input of the operational amplifier 201 through the resistor R5.
The positive input of the operational amplifier 201 is connected to the supply line of the comparator voltage Vs via the resistor R6.
The output of the operational amplifier 201 is connected to a power source that supplies the voltage Vcc via a resistor R4. This power supply supplies power to the logic circuit constituting the rotation amount detection unit 9.
The operational amplifier 201 amplifies the voltage difference between the positive input and the negative input.
[0031]
The reference voltage Vb is, for example, 1.5V. On the other hand, the comparator voltage Vs is set to a minute voltage, for example, several hundred mV, or lower than the reference voltage Vb. Specifically, the comparator voltage Vs is set to 1.4 V, for example.
In the differential input amplifier 7, the induced voltage generated in the detection coil 122 is amplified with reference to the reference voltage Vb.
In the comparator 8, the output voltage of the differential input amplifier 7 is compared with the comparator voltage Vs.
The reason why the reference voltage Vb and the comparator voltage Vs are different will be described later.
[0032]
The disconnection detection circuit 11 is a connection between the backup circuit 2 and the resolver 120 due to disconnection of the cable 30 connecting the backup circuit 2 and the resolver 120 or disconnection of a connector used between the backup circuit 2 and the resolver 120. Detects route blockage.
The disconnection detection circuit 11 receives the comparator signal COMP of the comparator 8. The disconnection detection circuit 11 receives two clock signals CLK1 and CLK2.
The clock generation circuit 10 generates two clock signals CLK1 and CLK2. The clock generation circuit 10 generates two clock signals CLK1 and CLK2 in accordance with the generation periods of the excitation signals Pa and Pb generated by the pulse generation circuit 3. The clock signals CLK1 and CLK2 are generated before the excitation signal Pa is generated, and the clock signal CLK2 is generated after the excitation signal Pb is generated.
[0033]
FIG. 5 is a circuit diagram illustrating a configuration example of the disconnection detection circuit 11.
As illustrated in FIG. 5, the disconnection detection circuit 11 includes a plurality of flip-flop circuits 250 to 254 and an AND circuit 255.
Note that the flip-flop circuit 250 is an embodiment of the first detection circuit of the present invention that detects the presence / absence of a change in the comparator signal COMP at every generation period of the excitation signals Pa and Pb. The flip-flop circuits 251 to 254 and the AND circuit 255 constitute a second detection circuit of the present invention.
[0034]
A power supply for supplying the voltage Vcc is connected to the input terminal D of the flip-flop circuit 250, the clock signal CLK1 is input to the clock terminal CLK, and the comparator signal COMP is input to the reset terminal / RST.
[0035]
The output terminal Q of the flip-flop circuit 250 is connected to the input terminal D of the flip-flop circuit 251, the output terminal Q of the flip-flop circuit 251 is connected to the input terminal D of the flip-flop circuit 252, and the output of the flip-flop circuit 252 The terminal Q is connected to the input terminal D of the flip-flop circuit 253.
[0036]
The clock signal CLK2 is input to each clock terminal CLK of the flip-flop circuits 251 to 253.
Each output terminal Q of the flip-flop circuits 251 to 253 is connected to the input of the AND circuit 255.
The power supply for supplying the voltage Vcc is connected to the input terminal D of the flip-flop circuit 254, and the output signal of the AND circuit 255 is input to the clock terminal CLK. The output signal of the output terminal Q of the flip-flop circuit 255 becomes the detection signal 11s.
[0037]
Next, an example of operation | movement of the resolver signal processing apparatus 1 of the said structure is demonstrated.
When the control power supply 140 is turned on
When the control power supply 140 is turned on, the main power supply 25 is turned on. When the main power supply 25 is turned on, the angle conversion circuit 12 and the controller 100 can be operated. The backup circuit 2 is also supplied with power from the main power supply 25 by the power supply switching circuit 130. Further, the pulse generation circuit 3 cancels the detection signal 6s from the power failure detection circuit 6.
When the reset of the controller 100 is released, the controller 100 reads the rotation amount rd during the power failure from the rotation amount detection unit 9. Thereby, the controller 100 can acquire the rotation amount of this control object, for example, when the control object rotates while the power supply from the main power supply 25 is cut off.
The controller 100 reads the rotation amount rd during a power failure from the rotation amount detection unit 9 and then outputs an excitation switching signal 100 as to the pulse generation circuit 3.
[0038]
The pulse generation circuit 3 switches from the excitation data holding unit 5 at the time of power failure to the excitation data holding unit 4 at the time of non-power failure, and supplies the excitation signals Vpa and Vpb modulated in pulse width shown in FIG. 2 to the excitation coils 121A and 121B. .
Next, the controller 100 reads the rotation angle signal RD of the current rotor rotation angle θ from the angle conversion circuit 12. The rotation angle θ is data indicating the rotational position of the rotor within 360 °.
The controller 100 can recognize the absolute coordinate value of the control target from the rotation amount rd stored in the rotation amount detection unit 9 and the rotation angle signal RD from the angle conversion circuit 12.
[0039]
When the control power supply 140 is off
When the control power supply 140 is turned off, the control power failure detection circuit 110 detects this and outputs a detection signal 110 s to the controller 100.
The controller 100 receives the detection signal 110 s and reads the rotation angle signal RD of the current rotor rotation angle θ of the resolver 120 from the angle conversion circuit 12. The controller 100 performs backup of absolute value coordinates based on the rotation angle θ. Thereby, the absolute value coordinates when the control power supply 140 is turned off are stored in the controller 100.
[0040]
Further, the controller 100 outputs an excitation switching signal 100as to the pulse generation circuit 3.
Upon receiving the excitation switching signal 100as, the pulse generation circuit 3 switches the data to be read from the non-power failure excitation data holding unit 4 to the power failure excitation data holding unit 5. Thus, the excitation signals Pa and Pb shown in FIG. 3 are supplied to the resolver 120.
Thereafter, the supply voltage of the main power supply 25 is lowered, and the backup circuit 2 receives power from the backup power supply 21 instead of the main power supply 25 by the power supply switching circuit 130.
[0041]
When the supply voltage of the main power supply 25 decreases, the power failure detection circuit 6 detects this, and outputs a detection signal 6 s to the pulse generation circuit 3.
When a predetermined time (for example, 9 seconds) elapses after receiving the detection signal 6s, the pulse generation circuit 3 receives the period T of the excitation signals Pa and Pb shown in FIG.₁ Is extended to a predetermined multiple (eg, 16 times).
[0042]
FIG. 6 is a diagram illustrating a change example according to the rotation angle θ of the induced voltage generated in the detection coil 122 when the excitation signals Pa and Pb are supplied to the excitation coils 121A and 121B. The output voltage shown in FIG. 6 is the output of the differential input amplifier 7.
As shown in FIG. 6, the induced voltage generated in the detection coil 122 changes according to the rotation angle θ of the rotor. That is, the excitation signals Pa and Pb are modulated according to the rotation angle θ of the rotor.
Further, as can be seen from FIG. 6, the transient response of the voltage waveform generated in the detection coil 122 with respect to the pulsed excitation signals Pa and Pb is exceeded by the output impedance of the detection coil 122 and the backup circuit 2 as shown by a circle. Shoot (undershoot) occurs.
On the other hand, if the connection path is interrupted by disconnection of the cable 30 or disconnection of the connector, no response to the excitation signals Pa and Pb occurs.
[0043]
The output voltage of the differential input amplifier 7 is compared with the comparator voltage Vs by the comparator 8.
Here, the reason why the comparator 8 performs the comparison using the comparator voltage Vs instead of the reference voltage Vb will be described.
As shown in FIG. 6, the voltage waveform generated in the detection coil 122 with respect to the pulsed excitation signals Pa and Pb causes an overshoot (undershoot) with respect to the reference voltage Vb.
Assume that the output voltage of the differential input amplifier 7 does not cause an overshoot (undershoot) with respect to the reference voltage Vb, and the output voltage of the differential input amplifier 7 is compared with the reference voltage Vb. If the overshoot (undershoot) does not occur in the waveform such as the rotation angle θ shown in FIG. 6 of 0 °, 270 °, 315 °, 360 °, the comparator signal by the reference voltage Vb does not change and is constant. It remains. That is, when the output voltage of the differential input amplifier 7 changes only to one side with respect to the reference voltage Vb, the comparator signal is the same as that at the time of disconnection.
[0044]
In the present embodiment, based on the comparator signal COMP of the comparator 8, it is determined whether or not the cable 30 is disconnected or the connector is disconnected. For this reason, if the comparator signal at the time of non-disconnection and the comparator signal at the time of disconnection are the same, it cannot be determined whether the cable 30 is disconnected or the connector is disconnected.
Therefore, in the present embodiment, it is positively utilized that overshoot (undershoot) always occurs in the voltage waveform generated in the detection coil 122 with respect to the pulsed excitation signals Pa and Pb. That is, when the comparator voltage Vs is slightly different in the plus or minus direction with respect to the reference voltage Vb, the comparator signal is converted into pulsed excitation signals Pa and Pb regardless of the rotation angle θ. Correspondingly changes. The comparator voltage Vs is set to a range in which overshoot (undershoot) in the output voltage of the differential input amplifier 7 can be detected.
[0045]
FIG. 7 is a diagram illustrating an example of a comparator signal compared with the comparator voltage Vs by the comparator 8.
As shown in FIG. 7, the comparator signal changes according to the rotation angle θ of the rotor.
The rotation amount detector 9 latches this comparator signal at, for example, latch timings Lpa and Lpb synchronized with the fall of the excitation signal Pa and the excitation signal Pb.
[0046]
A-phase data is obtained by latching the comparator signal based on the latch timing Lpa.
B-phase data is obtained by latching the comparator signal at the latch timing Lpb.
The A phase data is an embodiment of the first phase signal of the present invention, and the B phase data is an embodiment of the second phase signal of the present invention.
Further, as can be seen from FIG. 7, when the cable 30 is not disconnected or the like, it can be seen that the comparator signal always changes in accordance with the generation periods of the excitation signals Pa and Pb.
On the other hand, when the cable 30 is disconnected, the comparator signal is always “1” (high level).
[0047]
FIG. 8 is a diagram illustrating an example of A-phase data and B-phase data.
As can be seen from FIG. 8, the phase of the A-phase data and the B-phase data differ by 90 °. The A-phase data and the B-phase data change every time the rotation angle θ of the rotor changes by 180 °.
The rotation amount detector 9 can detect the rotation direction and the rotation angle θ of the rotor every 90 ° by detecting the rising and falling edges of the A-phase data and the B-phase data.
Thus, the rotation amount detection unit 9 detects the rotation amount rd of the rotor while the main power supply 25 is shut off from the A phase data and the B phase data, and stores and stores this.
[0048]
On the other hand, the disconnection detection circuit 11 receives the comparator signal COMP from the comparator 8 and the clock signals CLK 1 and CLK 2 from the clock generation circuit 10.
FIG. 9 is a timing chart of each signal in the disconnection detection circuit 11 when the connection path between the backup circuit 2 and the resolver 120 is not blocked.
As shown in FIG. 9, the clock signal CLK1 is input to the flip-flop circuit 250 a predetermined time before the time when the excitation signal Pa is input. When the clock signal CLK1 is input, the output signal Q1 from the output terminal Q of the flip-flop circuit 250 becomes high level.
Thereafter, when the comparator signal COMP is input to the reset terminal / RST of the flip-flop circuit 250, the output signal Q1 becomes low level.
[0049]
The flip-flop circuits 251 to 253 receive the clock signal CLK2 after a predetermined time from the time when the excitation signal Pb is input.
At the time of non-disconnection, since a low level signal is always input to the input terminal D when the clock signal CLK2 is input to the clock terminals CLK of the flip-flop circuits 251 to 253, the flip-flop circuits 251 to 253 A low level signal is output from the output terminal Q. For this reason, the output signal of the AND circuit 255 is always low and does not change.
Therefore, since the signal input to the clock terminal CLK of the flip-flop circuit 254 at the final stage does not change, the detection signal 11s output from the output terminal Q of the flip-flop circuit 254 is always low as shown in FIG. Become a level. Note that the flip-flop circuit 254 at the final stage outputs a low level signal from the output terminal Q at the time of reset.
When the control power supply 140 is turned on again and the detection signal 11s is at a low level, the controller 100 determines that the connection path is not disconnected due to the disconnection of the cable 30 or the disconnection of the connector.
[0050]
FIG. 10 is a timing chart of each signal in the disconnection detection circuit 11 when the connection path between the backup circuit 2 and the resolver 120 is interrupted.
As shown in FIG. 10, when disconnection occurs, the comparator signal COMP is not input to the disconnection detection circuit 11. When the comparator signal COMP is no longer input to the disconnection detection circuit 11, the output signal Q1 of the output terminal Q of the flip-flop circuit 250 is maintained at "1" (high level) after the clock signal CLK1 is input.
Therefore, every time the excitation signals Pa and Pb are generated, a signal of “1” (high level) as a disconnection detection result is held in the order of the flip-flop circuits 251, 252 and 253.
When all of the flip-flop circuits 251, 252, and 253 hold a signal of “1” (high level), the output signal of the AND circuit 255 becomes a signal of “1” (high level).
As a result, the detection signal 11s output from the flip-flop circuit 254 becomes "1" (high level) as shown in FIG.
[0051]
When the control power supply 140 is turned on again and the detection signal 11s is at a high level, the controller 100 determines that the connection path is interrupted due to the disconnection of the cable 30 or the disconnection of the connector.
[0052]
As described above, according to the present embodiment, while the backup circuit 2 is operated by the backup power source 21, the cable is used by using the comparator signal COMP used by the rotation amount detection unit 9 that detects the rotation amount during a power failure. The disconnection of the connection path due to the disconnection of 30 or the disconnection of the connector is detected.
As a result, it is possible to detect the disconnection of the connection path during a power outage, and it is not necessary to use a photocoupler or the like to detect the disconnection of the connection path, and the power consumption does not increase.
Moreover, since the disconnection detection circuit 11 is not affected by the magnitude of the impedance of the cable 30, the cable 30 can be extended.
[0053]
In the embodiment described above, the digital filter is configured using the three flip-flop circuits 251 to 253. The number of flip-flop circuits constituting the digital filter can be appropriately changed depending on the balance between the detection speed and noise resistance.
[0054]
Second embodiment
FIG. 11 is a functional block diagram showing a configuration of a resolver signal processing device according to another embodiment of the present invention. In FIG. 11, the same components as those of the resolver signal processing apparatus according to the first embodiment are denoted by the same reference numerals.
In FIG. 11, the resolver signal processing device 101 includes a backup circuit 102, an angle conversion circuit 12, and changeover switch groups 150 and 151.
The backup circuit 102 includes a pulse generation circuit 103, a non-power failure excitation data holding unit 104, a power failure excitation data holding unit 105, a power failure detection circuit 106, differential input amplifiers 107A and 107B, and comparators 108A and 108B. , A rotation amount detection unit 109, a clock generation circuit 110, and a disconnection detection circuit 111.
A backup power source 21 and a main power source 25 are electrically connected to the backup circuit 102 via a power source switching circuit 130.
[0055]
The changeover switch group 150 includes four switches SW1 to SW4.
The switches SW1 to SW4 have terminals Ta, Tb, and Tc, and selectively electrically connect the terminals Ta and Tb to the terminal Tc.
The switches SW1 to SW4 are switched according to a switching signal 150s from the controller 100.
Terminals Tc of the switches SW1 and SW3 are electrically connected to both ends of the coil 121A.
Terminals Tc of the switches SW2 and SW4 are electrically connected to both ends of the coil 121B, respectively.
Terminals Ta of the switches SW1 to SW4 are electrically connected to output terminals A1 to A4 of the pulse generation circuit 103, respectively.
The terminals Tb of the switches SW1 to SW4 are electrically connected to the input terminals of the differential input amplifiers 107A and 107B, respectively.
[0056]
The changeover switch group 151 has two switches SW5 and SW6.
The switches SW5 and SW6 have terminals Ta, Tb, and Tc, and selectively electrically connect the terminals Ta and Tb and the terminal Tc.
The switches SW5 and SW6 are switched according to a switching signal 151s from the controller 100.
Terminals Ta of the switches SW5 and SW6 are electrically connected to the input ends of the angle conversion circuit 12, respectively.
The terminals Tb of the switches SW5 and SW6 are electrically connected to the output terminals A1 and A3 of the pulse generation circuit 103, respectively.
Terminals Tc of the switches SW5 and SW6 are electrically connected to both ends of the coil 122, respectively.
[0057]
When receiving power from the main power supply 25, the controller 100 outputs switching signals 150 s and 151 s for instructing connection between the terminals Ta and the terminals Tc of the switches SW <b> 1 to S <b> 6 to the switching switch groups 150 and 151.
When controller 100 receives detection signal 110 s from control power failure detection circuit 110, controller 100 outputs switching signals 150 s and 151 s for instructing connection between terminals Tb and terminals Tc of switches SW <b> 1 to S <b> 6 to changeover switch groups 150 and 151.
[0058]
The power failure detection circuit 106 has a function similar to that of the power failure detection circuit 6 according to the above-described embodiment. When the power failure detection circuit 106 detects that power supply from the main power supply 25 to the backup circuit 102 is cut off, the detection signal 106s is pulsed. Output to the generation circuit 103.
[0059]
The non-power failure excitation data holding unit 104 is similar to the non-power failure excitation data holding unit 4 according to the first embodiment described above when the pulse generation circuit 103 is supplied with power from the main power supply 25. Excitation data of an excitation signal to be output from the pulse generation circuit 103 is held.
Similarly to the power failure excitation data holding unit 4 according to the first embodiment described above, the power failure excitation data holding unit 5 is cut off from the power supply to the pulse generation circuit 103 from the main power supply 25 and is supplied from the backup power source 21. Excitation data of an excitation signal to be output from the pulse generation circuit 103 is held when receiving power.
[0060]
When receiving power from the main power supply 25, the pulse generation circuit 103 outputs a pulsed excitation signal from the output terminals A1 to A4 based on the excitation data stored in the excitation data holding unit 104 during non-power failure. To do. This excitation signal is supplied to the two-phase coils 121A and 121B.
In addition, when the excitation switching signal 100as is input, the pulse generation circuit 103 outputs a pulse-shaped excitation signal having a predetermined cycle only from the output terminal A1 based on the excitation data stored in the excitation data holding unit 105 during a power failure. To do. This excitation signal is supplied to the one-phase coil 122. Note that excitation signals are not output from the output terminals A2, A3, and A4.
Furthermore, when the detection signal 106s is input from the power failure detection circuit 106, the pulse generation circuit 103 extends the excitation cycle of the excitation signal output from the output terminal A1 by a predetermined time, for example, 16 times.
[0061]
The differential input amplifiers 107A and 107B have the same configuration as that of the differential input amplifier 7 according to the first embodiment described above.
In the differential input amplifier 107A, the induced voltage generated at both ends of the coil 121A by the excitation signal is differentially input as a reference voltage, and is amplified.
In the differential input amplifier 107B, the induced voltage generated at both ends of the coil 121B by the excitation signal is differentially input as a reference voltage, and is amplified.
[0062]
The comparators 108A and 108B have the same configuration as the comparator 8 according to the first embodiment described above.
The comparator 108A compares the output voltage of the differential input amplifier 107A with a comparison voltage different from the reference voltage described above, and outputs the generated comparison signal COMPA to the rotation amount detection unit 109.
The comparator 108B compares the output voltage of the differential input amplifier 107B with a comparison voltage different from the reference voltage described above, and outputs the generated comparison signal COMPB to the rotation amount detection unit 109.
Note that the comparator voltages in the comparators 108A and 108B are set in the same manner as in the first embodiment.
[0063]
The rotation amount detection unit 109 slightly compares the comparator signals COMPA and COMPB of the comparators 108A and 108B, for example, in the latch timing synchronized with the falling edge of the excitation signal or in either positive or negative direction with respect to this latch timing. Latch at the shifted timing.
By latching the A-phase and B-phase comparator signals, respectively, the same A-phase data and B-phase data as shown in FIG. 8 are obtained.
Then, from the obtained A-phase signal and B-phase signal, the amount of rotation of the rotor with respect to the stator of the resolver 120 is detected and stored.
[0064]
The clock generation circuit 110 generates clock signals CLK1 and CLK2 and supplies them to the disconnection detection circuit 11 in the same manner as the clock generation circuit 10 according to the first embodiment described above.
[0065]
The disconnection detection circuit 111 includes a backup circuit 2 due to disconnection of a cable connecting the backup circuit 102 and the resolver 120, disconnection of a connector used between the backup circuit 102 and the resolver 120, failure of the changeover switch groups 150 and 151, and the like. And the disconnection of the connection path between the resolver 120 and the resolver 120.
FIG. 12 shows an example of the circuit configuration of the disconnection detection circuit 111.
The disconnection detection circuit 111 shown in FIG. 12 is obtained by adding an OR circuit 260 to the input terminal of the reset terminal / RST of the flip-flop circuit 250 of the disconnection detection circuit 11 according to the first embodiment described above.
The OR circuit 260 receives the comparison signals COMPA and COMPB, and takes these ORs and outputs them to the flip-flop circuit 250.
[0066]
Next, an example of operation | movement of the resolver signal processing apparatus 101 of the said structure is demonstrated.
When the control power supply 140 is turned on
When the control power supply 140 is turned on, the main power supply 25 is turned on. When the main power supply 25 is turned on, the angle conversion circuit 12 and the controller 100 can be operated. The backup circuit 102 is also supplied with power from the main power supply 25 by the power supply switching circuit 130. The pulse generation circuit 103 cancels the detection signal 106s from the power failure detection circuit 106.
When the reset of the controller 100 is released, the controller 100 reads the rotation amount rd during the power failure from the rotation amount detection unit 109. Thereby, the controller 100 can acquire the rotation amount of this control object, for example, when the control object rotates while the power supply from the main power supply 25 is cut off.
The controller 100 reads the rotation amount rd during a power outage from the rotation amount detection unit 109, and then outputs an excitation switching signal 100 as to the pulse generation circuit 103.
[0067]
Next, the controller 100 reads the rotation angle signal RD of the current rotor rotation angle θ from the angle conversion circuit 12. The rotation angle θ is data indicating the rotational position of the rotor within 360 °.
The controller 100 can recognize the absolute coordinate value of the control target based on the rotation amount rd stored in the rotation amount detection unit 109 and the rotation angle signal RD from the angle conversion circuit 12.
[0068]
The controller 100 reads the rotation amount rd during a power outage from the rotation amount detection unit 109, and then outputs an excitation switching signal 100 as to the pulse generation circuit 103.
Furthermore, the controller 100 outputs switching signals 150s and 151s for instructing the selector switches 150 and 151 to connect the terminal Tc and the terminal Ta.
When receiving the excitation switching signal 100as, the pulse generation circuit 103 switches the data to be read from the excitation data holding unit 5 at power failure to the excitation data holding unit 4 at non-power failure.
The output terminals A1 to A4 of the pulse generation circuit 103 are connected to the ends S1 to S4 of the coils 121A and 121B, and the angle conversion circuit 12 and the ends R1 and R2 of the coil 122 are connected. .
Thereby, the pulse generation circuit 103 supplies the excitation signals Vpa and Vpb subjected to pulse width modulation to the excitation coils 121A and 121B.
[0069]
Next, the controller 100 reads the rotation angle signal RD of the current rotor rotation angle θ from the angle conversion circuit 12. The rotation angle θ is data indicating the rotational position of the rotor within 360 °.
The controller 100 can recognize the absolute coordinate value of the control target based on the rotation amount rd stored in the rotation amount detection unit 109 and the rotation angle signal RD from the angle conversion circuit 12.
[0070]
When the control power supply 140 is off
When the control power supply 140 is turned off, the control power failure detection circuit 110 detects this and outputs a detection signal 110 s to the controller 100.
The controller 100 receives the detection signal 110 s and reads the rotation angle signal RD of the current rotor rotation angle θ of the resolver 120 from the angle conversion circuit 12. The controller 100 performs backup of absolute value coordinates based on the rotation angle θ. Thereby, the absolute value coordinates when the control power supply 140 is turned off are stored in the controller 100.
[0071]
Further, the controller 100 outputs an excitation switching signal 100 as to the pulse generation circuit 103.
In addition, the controller 100 outputs switching signals 150s and 151s for instructing the selector switch groups 150 and 151 to connect the terminals Tc and Tb.
[0072]
Upon receiving the excitation switching signal 100as, the pulse generation circuit 103 switches the data to be read from the non-power failure excitation data holding unit 104 to the power failure excitation data holding unit 105.
Further, the differential input amplifiers 107A and 107B and the coils 121A and 121B are connected, and the output ends A1 and A3 of the pulse generation circuit 103 and the ends R1 and R2 of the coil 122 are connected.
[0073]
As a result, the excitation signal Pa shown in FIG. 13 is supplied to the coil 122.
Thereafter, the supply voltage of the main power supply 25 is lowered, and the backup circuit 2 receives power from the backup power supply 21 instead of the main power supply 25 by the power supply switching circuit 130.
When the supply voltage of the main power supply 25 decreases, the power failure detection circuit 106 detects this, and outputs a detection signal 106 s to the pulse generation circuit 103.
When a predetermined time (for example, 9 seconds) elapses after receiving the detection signal 106s, the pulse generation circuit 103 extends the generation period of the excitation signal Pa shown in FIG. 13 by a predetermined time (for example, 16 times).
[0074]
As can be seen from FIG. 13, the output voltages of the differential input amplifiers 107A and 107B always overshoot (undershoot) with respect to the reference voltage Vb by the pulsed excitation signal Pa.
As in the first embodiment described above, when the comparator voltage Vs is slightly varied in the positive or negative direction with respect to the reference voltage Vb, the comparator signal COMPA is obtained regardless of the rotation angle θ. At least one of COMPB and COMPB changes corresponding to the pulsed excitation signal Pa.
On the other hand, when the connection path between the backup circuit 102 and the resolver 120 is cut off, the output voltages of the differential input amplifiers 107A and 107B become the reference voltage Vb and do not change.
[0075]
In the rotation amount detection unit 109, as shown in FIGS. 14A and 14B, the comparator signals COMPA and COMPB are set to, for example, the latch timing Lpa synchronized with the falling edge of the excitation signal Pa or the latch timing Lpa. On the other hand, it is latched at a timing slightly shifted in either positive or negative direction.
Thereby, the same A phase data and B phase data as shown in FIG. 8 are obtained. The rotation amount detection unit 109 detects the rotation amount rd of the rotor while the main power supply 25 is shut off from the A-phase data and the B-phase data obtained based on the excitation signal Pa, and stores and stores this.
[0076]
In the disconnection detection circuit 111, as shown in FIG. 14C, the OR signals 260 synthesize the comparator signals COMPA and COMPB.
Based on the combined comparator signals COMPA and COMPB, disconnection detection is performed as in the first embodiment.
From the disconnection detection circuit 111, the presence or absence of disconnection is output by a detection signal 111s.
[0077]
【The invention's effect】
According to the present invention, the circuit configuration of the resolver signal processing circuit can be simplified, and the power consumption of the backup circuit that operates when the main power supply is shut off can be reduced.
[Brief description of the drawings]
FIG. 1 is a functional block diagram showing a configuration of a resolver signal processing device according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating an example of an excitation signal generated based on data stored in a non-power failure excitation data holding unit in a pulse generation circuit.
FIG. 3 is a diagram illustrating an example of an excitation signal generated based on data stored in an excitation data holding unit during a power failure in a pulse generation circuit.
FIG. 4 is a diagram illustrating an example of a circuit of a differential input amplifier and a comparator.
FIG. 5 is a diagram illustrating an example of a disconnection detection circuit.
FIG. 6 is a diagram showing a change example according to a rotation angle θ of an induced voltage generated in a coil.
FIG. 7 is a graph showing an example of a compare signal.
FIG. 8 is a diagram showing an example of A-phase data and B-phase data.
FIG. 9 is a timing chart of each signal in the disconnection detection circuit 11 when the connection path between the backup circuit 2 and the resolver 120 is not interrupted.
10 is a timing chart of each signal in the disconnection detection circuit 11 when the connection path between the backup circuit 2 and the resolver 120 is interrupted. FIG.
FIG. 11 is a functional block diagram showing a configuration of a resolver signal processing device according to another embodiment of the present invention.
FIG. 12 is a circuit diagram showing an example of a configuration of a disconnection detection circuit.
FIG. 13 is a diagram showing a change example according to a rotation angle θ of an induced voltage generated in a coil.
FIG. 14 is a graph showing an example of a comparator signal and a signal obtained by combining these signals.
[Explanation of symbols]
1,101 ... Resolver signal processing device
2,102 ... Backup circuit
3,103 ... Pulse generation circuit
4,104 ... Excitation data holding part at non-power failure
5,105 ... Excitation data holding part at power failure
6,106 ... Power failure detection circuit
7, 107A, 107B ... Differential input amplifier
8, 108A, 108B ... Comparator
9, 109 ... rotation amount detection unit
10, 110 ... Clock generation circuit
11, 111 ... disconnection detection circuit
12 ... Angle conversion circuit
21 ... Backup power supply
25 ... Main power
100 ... Controller
110: Control power failure detection circuit
120 ... Resolver
130 ... Power supply switching circuit
140: Control power supply

Claims (3)

A resolver signal processing device for performing signal processing of a resolver having first and second coils capable of relative rotation,
The first power generation unit that is connected to the resolver and operates while receiving power supply from a backup power supply when power supply from a main power supply is cut off, and is generated while receiving power supply from the backup power supply. And a backup circuit that detects a relative rotation amount of the second coil based on a detection signal detected by the first or second coil,
The backup circuit is
Pulse generating means for supplying a pulsed excitation signal having a predetermined period to one of the first and second coils;
A differential input amplifier for amplifying the voltage generated by differentially inputting a voltage generated in the other of the first and second coils with a reference voltage;
A comparator that compares the output voltage of the differential input amplifier with a comparator voltage different from the reference voltage;
A circuit for detecting and storing the relative rotation amount from the first phase signal and the second phase signal obtained by latching the comparator signal of the comparator based on the excitation timing of the excitation signal;
Based on the comparator signal of the comparator, a disconnection detection circuit that detects the presence or absence of disconnection of the connection path between the resolver and the backup circuit ;
I have a,
The comparator voltage is such that when the connection path is not interrupted, the comparator's comparator signal is the excitation signal of the pulse generating means, regardless of the relative rotational positions of the first and second coils. A resolver signal processing device set to a value that changes in accordance with the generation period . The disconnection detection circuit includes a first detection circuit that detects presence or absence of a change in the comparator signal for each generation period of the excitation signal;
The detection result of the first detection circuit is held over a plurality of the generation periods, and a detection signal for detecting whether the connection path is blocked is generated based on the detection results in the generation periods. The resolver signal processing device according to claim 1 , comprising: two detection circuits. It said pulse generating means, when it is supplied with electric power from the main power source, a pulsed excitation signal is supplied to the one or the other of the first and second coil based on the first excitation data, wherein when receiving power from a backup power supply according to claim 1 or 2 for supplying a pulsed excitation signal based on the second excitation data into said one of said first and second coil Resolver signal processing device.

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