JP2006300594A - Angle of rotation detecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize an A/D transform means with a simple circuit constitution also with a constitution in which the high speed operation is made unnecessary. <P>SOLUTION: The angle of rotation detection device is constituted that the prescribed reference analogue sine wave signal is applied on the primary winding of a resolver and the angle of rotation of the rotor is detected based on the measured two analogue signals outputted from the secondary two windings of the resolver. The device is provided with the first A/D conversion means for A/D converting the value obtained by integrating the first measured analogue signal outputted from either side secondary winding for every half period of reference analogue sine wave signal, and also provided with the second A/D conversion means for A/D converting the value obtained by integrating the second measured analogue signal outputted from the other secondary winding for every half period of reference analogue sine wave signal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention applies a predetermined reference analog sine wave signal to the primary winding of the resolver, and detects the rotation angle of the rotor based on the two measurement analog signals output from the two secondary windings of the resolver. The present invention relates to a rotation angle detection device configured as described above.

As an example of a device that detects the rotation angle of a rotor such as a brushless motor, there is a detection device that uses a resolver. In this detection device, two analog signals output from the resolver are taken in at the A / D conversion input terminal of the microcomputer, and the rotation angle is calculated by executing complicated arithmetic processing in software. .
Japanese Patent No. 3508718

  In the case of the above conventional configuration, there is a disadvantage that an expensive microcomputer capable of executing high-speed computation is required. On the other hand, the configuration described in Patent Document 1 is configured such that high-speed computation is not required and an expensive microcomputer is not required. In the case of the configuration of this Patent Document 1, the two analog signals output from the resolver are A / D converted, and then included in the analog signal based on the A / D converted value. Is configured to calculate the amplitude of the sine wave component of the same frequency.

  However, in the configuration of Patent Document 1, an A / D conversion circuit (A / D conversion means) having a configuration capable of high-speed sampling is required as a circuit for A / D converting two analog signals output from the resolver. Therefore, there is a problem that the circuit configuration of this part is complicated and expensive.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a rotation angle detection device that can realize a high-speed calculation and can realize an A / D conversion means with a simple circuit configuration.

  The rotation angle detection device of the present invention applies a predetermined reference analog sine wave signal to the primary winding of the resolver, and the rotor based on the two measurement analog signals output from the two secondary windings of the resolver. In the rotation angle detecting device configured to detect the rotation angle of the sine wave component having the same frequency as the reference analog sine wave signal included in the first measurement analog signal output from the one secondary winding. A first amplitude deriving unit for deriving an amplitude, and a second for deriving the amplitude of a sine wave component having the same frequency as the reference analog sine wave signal included in the second measurement analog signal output from the other secondary winding. An amplitude deriving unit, wherein the first amplitude deriving unit performs A / D conversion on a value obtained by integrating the first measurement analog signal every ½ period of the reference analog sine wave signal. D conversion means Based on the value A / D converted by the first A / D conversion means, a first sine wave component included in the first measurement analog signal and having the same frequency as the reference analog sine wave signal is calculated. A second amplitude deriving unit configured to perform A / D conversion on a value obtained by integrating the second measurement analog signal every ½ period of the reference analog sine wave signal. A / D conversion means and a sine wave having the same frequency as that of the reference analog sine wave signal, which is included in the second measurement analog signal based on the value A / D converted by the second A / D conversion means It is characterized by comprising a second amplitude calculation means for calculating the amplitude of the component.

  According to the above configuration, the integration type A / D conversion unit is used as the A / D conversion unit of the first amplitude deriving unit and the second amplitude deriving unit. In addition, the A / D conversion means can be realized with a simple circuit configuration.

  Further, in the case of the above configuration, the first amplitude calculation means and the second amplitude calculation means perform A / D conversion on a value that is binarized for every half period of the reference analog sine wave signal. Preferably, the amplitude is calculated by multiplying the value.

  Further, the first amplitude calculation means and the second amplitude calculation means are configured to obtain a current A / D converted value from a previous A / D converted value at a timing of every n times the period of the reference analog sine wave signal. It is preferable that the amplitude is calculated by subtraction.

  Furthermore, the first A / D conversion means and the second A / D conversion means are connected to a plurality of inversion circuits that invert the input signal and output the inversion operation time depending on the power supply voltage. A pulse running circuit; an A / D input voltage signal input terminal connected to a power supply line of each inverting circuit in the pulse running circuit and applied as a power supply voltage of the inverting circuit for writing the power supply voltage signal; A traveling position detecting means for generating data corresponding to the position of the pulse traveling circuit, a means for holding the detected data by the traveling position detecting means, and a difference between the previous data and the current data as an A / D conversion result It is even more preferable that the apparatus is provided with a means for outputting.

  The first embodiment of the present invention will be described below with reference to FIGS. The rotation angle detection device of the present embodiment includes a signal processing circuit 1 (see FIG. 1) and a resolver 2 (see FIG. 2). The resolver 2 is a resolver having a known configuration and includes a primary winding 3 on an excitation side (rotor) and two secondary windings 4 and 5 on an output side (stator). The two secondary windings 4 and 5 are provided so as to be orthogonal to each other.

  The signal processing circuit 1 includes a reference clock generation unit 6, a timing signal generation unit 7, a sine wave generation unit 8, a D / A conversion circuit 9, and a first A / D conversion circuit (first A / D conversion circuit). Conversion means) 10, a first amplitude calculation section (first amplitude calculation means) 11, a second A / D conversion circuit (second A / D conversion means) 12, and a second amplitude calculation section. (Second amplitude calculation means) 13 and a rotation angle calculation unit 14 are provided.

  The reference clock signal Sa output from the reference clock generation unit 6 is provided to the sine wave generation unit 8 via the timing generation unit 7, and the sine wave generation unit 8 receives a predetermined digital signal based on the reference clock signal Sa. The sine wave signal Sb is generated and applied to the D / A conversion circuit 9. The D / A conversion circuit 9 D / A converts the digital sine wave signal Sb to generate an analog sine wave signal Sc, and this reference analog sine wave signal Sc is a terminal of the primary winding 3 of the resolver 2. It is comprised so that it may apply between R1 and R2.

  The timing signal generator 7 is a signal having a value that is binarized on the basis of the reference clock signal Sa output from the reference clock generator 6 every ½ period of the reference analog sine wave signal Sc. Sj (see FIG. 4E) is generated and provided to the first amplitude calculation unit 11 and the second amplitude calculation unit 13. Further, the timing signal generator 7 is based on the reference clock signal Sa output from the reference clock generator 6 to generate a pulse signal Sk having a period ½ of the reference analog sine wave signal Sc (FIG. 4C). The first A / D conversion circuit 10 and the second A / D conversion circuit 14 are generated.

  Now, the first measurement analog signal Sd (voltage signal between the terminals T1 and T3 of the secondary winding 4) output from one of the secondary windings 4 of the resolver 2 is sent to the first A / D conversion circuit 10. The A / D conversion is performed here, and the A / D converted first measurement signal Se is supplied to the first amplitude calculation unit 11. The first amplitude calculator 11 derives the amplitude of a sine wave component having the same frequency as the reference analog sine wave signal Sc included in the first measurement analog signal Sd based on the first measurement signal Se. As shown in the left half graph in FIG. 1, an envelope (envelope curve) signal (a (cos θ) signal) Sf of the first measurement analog signal Sd is output. This signal Sf is given to the rotation angle calculator 14. In this case, the first amplitude derivation means is constituted by the first A / D conversion circuit 10 and the first amplitude calculation unit 11.

  Further, the second measurement analog signal Sg (voltage signal between the terminals T2 and T4 of the secondary winding 5) output from the other secondary winding 5 of the resolver 2 is sent to the second A / D conversion circuit 12. The A / D conversion is performed here, and the second measurement signal Sh subjected to the A / D conversion is provided to the second amplitude calculator 13. The second amplitude calculation unit 13 derives the amplitude of the sine wave component having the same frequency as the reference analog sine wave signal Sc included in the second measurement analog signal Sg based on the second measurement signal Sh. As shown in the graph in the left half of FIG. 1, an envelope (envelope curve) signal (b (sin θ) signal) Si of the second measurement analog signal Sg is output. This signal Si is given to the rotation angle calculator 14. In this case, the second amplitude derivation means is constituted by the second A / D conversion circuit 12 and the second amplitude calculation unit 13.

  Then, the rotation angle calculation unit 14 rotates the rotor based on the a (cos θ) signal Sf from the first amplitude calculation unit 11 and the b (sin θ) signal Si from the second amplitude calculation unit 13. The angle θ is calculated by the following formula, and the calculation result θ is output.

θ = tan ⁻¹ (b / a)
Thus, the signal processing circuit 1 is configured to detect the rotation angle θ of the rotor and to output the detected rotation angle θ from the signal processing circuit 1.

Two output signals Sd (voltage E _T1-T3 between T1 and T3 of the secondary winding 4), Sg (voltage E _T2-T4 between T2 and T4 of the secondary winding 5) output from the resolver 2 ) Is expressed as follows:

E _T1-T3 = KEsinωt · cosθ
E _T2-T4 = KEsinωt · sinθ
Where K is the transformation ratio, θ is the rotation angle (degrees), ω = 2πf, t is the time (seconds), f is the excitation frequency (Hz), and E is the excitation voltage amplitude (V).
Next, the first amplitude calculator 11 and the second amplitude calculator 13 will be described. Since the first amplitude calculator 11 and the second amplitude calculator 13 are circuits having the same configuration, the first amplitude calculator 11 will be described with reference to FIG. As shown in FIG. 3, the first amplitude calculation unit 11 converts the signal Sj from the timing signal generation unit 7 (that is, a value that is binarized into positive and negative values every ½ period of the reference analog sine wave signal Sc). The amplitude is calculated by multiplying the A / D-converted first measurement signal Se (that is, the A / D-converted value) from the first A / D conversion circuit 10, and the a (cos θ) The signal Sf (that is, the envelope signal of the first measurement analog signal Sd) is output. In this case, the first amplitude calculator 11 is configured by a circuit having a multiplication function.

  Similarly, the second amplitude calculator 13 multiplies the signal Sj from the timing signal generator 7 and the A / D converted second measurement signal Sg from the second A / D converter circuit 12. By combining them, the amplitude is calculated and the b (sin θ) signal Sh is output.

  Further, since the first A / D conversion circuit 10 and the second A / D conversion circuit 12 are circuits having the same configuration, the first A / D conversion circuit 10 is described with reference to FIGS. I will explain. The first A / D conversion circuit 10 is a so-called integration type A / D conversion circuit, which converts the first measurement analog signal Sd, which is an input voltage signal, into a period of ½ of the reference analog sine wave signal Sc. It has a function of A / D converting the value integrated into. The first A / D conversion circuit 10 has almost the same configuration as the A / D conversion circuit described in Japanese Patent No. 3064644.

  As shown in FIG. 4, the first A / D conversion circuit 10 includes a pulse traveling circuit 15, a first latch (pulse selector) 16, an encoder 17, a counter 18, a first ′ latch 19, The second latch 20, the third latch 21, the subtraction circuit 22, and the fourth latch 23 are configured. As shown in FIG. 6, the first latch 16, the first 'latch 19, the second latch 20, the third latch 21, and the fourth latch 23 operate in synchronization with the rising edge of the pulse signal Sk. .

  The pulse transit circuit 15 is configured by connecting a NAND circuit (invert circuit) and a plurality of inverter circuits (invert circuits) in a ring shape. That is, the pulse running circuit 15 is a circuit in which a plurality of inversion circuits whose inversion operation time varies depending on the power supply voltage are connected while the input signal is inverted and output. The A / D input voltage signal input terminal 24 is connected to the power supply line of each inverting circuit in the pulse transit circuit 15 and inverts the first measurement analog signal Sd (power supply voltage signal) which is an input voltage signal. Applied as power supply voltage for the circuit.

  The first latch 16 takes in the output of each inverting circuit of the pulse traveling circuit 15 and extracts a pulse signal that circulates in the pulse traveling circuit 15 from the output level to generate a signal representing the position. The encoder 17 generates digital data corresponding to the output signal from the first latch 16.

  The counter 18 counts the number of times the pulse signal circulates in the pulse traveling circuit 15 from the number of inversions of the output level of the inverter circuit in the pulse traveling circuit 15 and outputs digital data (count value). The first 'latch 19 latches the digital data from the counter 18.

  Then, the second latch 20 inputs the digital data from the first 'latch 19 as upper bits, and inputs the digital data from the encoder 17 as lower bits and latches. In this case, a traveling position detecting means for generating data corresponding to the position of the pulse traveling circuit 15 for each reference clock is constituted by the first latch 16, the encoder 17, the counter 18, the first 'latch 19 and the second latch 20. Has been.

  The third latch 21 inputs and latches the data in the second latch 20 with a delay of one pulse (clock) (see FIGS. 6C and 6D). In this case, the third latch 21 constitutes means for holding data previously detected by the traveling position detection means. The subtraction circuit 22 subtracts the data in the third latch 21 from the data in the second latch 20, that is, calculates the difference between the previous data and the current data. The fourth latch 23 latches the subtraction result and outputs it as an A / D conversion result (see FIG. 6E). In this case, the subtraction circuit 22 and the fourth latch 23 constitute means for outputting the difference between the previous data and the current data as an A / D conversion result.

  Then, the first measurement signal Se A / D converted by the first A / D conversion circuit 10 having the above-described configuration is a signal as shown in FIG. The first measurement analog signal Sd output from one secondary winding 4 of the resolver 2 is a signal shown in FIG. Then, the a (cos θ) signal Sf, which is the calculation result by the first amplitude calculation unit 11, becomes a signal shown in FIG. 4F, and is a signal sufficiently approximated as an envelope signal of the first measurement analog signal Sd. I understand that.

  According to the present embodiment having such a configuration, as the first A / D conversion circuit 10 and the second A / D conversion circuit 12 of the first amplitude deriving means and the second amplitude deriving means, an integral type A / D conversion circuit is used. Since the configuration is such that the D conversion circuit (see FIG. 5) is used, the A / D conversion circuit can be realized with a simple circuit configuration, and an A / D conversion circuit capable of high-speed sampling is not required.

  In the case of the above embodiment, a circuit having a configuration as shown in FIG. 5 is used as the integrating A / D conversion circuit, that is, the first A / D conversion circuit 10 and the second A / D conversion circuit. The / D conversion circuit 12 inverts and outputs the input signal, and a pulse running circuit 15 in which a plurality of inversion circuits whose inversion operation time varies depending on the power supply voltage are connected, and a power source for each inversion circuit in the pulse running circuit 15 A / D input voltage signal input terminal 24 connected to the line and applying the power supply voltage signal as a power supply voltage of each inverting circuit, and a travel position detection for generating data corresponding to the position of the pulse travel circuit for each reference clock And a means for holding data previously detected by the travel position detecting means, and a means for outputting a difference between the previous data and the current data as an A / D conversion result. As a result, an integral type A / D conversion circuit having a sufficiently effective A / D conversion function can be realized by a digital circuit, so that the chip area of the IC can be reduced with the miniaturization of CMOS. It becomes possible.

  Moreover, in the case of the said Example, the 1st amplitude calculating part 11 and the 2nd amplitude calculating part 13 change the value which carries out positive / negative binarization for every 1/2 period of a reference | standard analog sine wave signal to 1st A. The amplitude is calculated by multiplying the value subjected to A / D conversion by the / D conversion circuit 10 and the second A / D conversion circuit 12. For this reason, it can be set as the structure which does not require a high-speed calculation, and an expensive microcomputer can be made unnecessary.

  7 and 8 show a second embodiment of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals. In the second embodiment, the first amplitude calculation unit 24 and the second amplitude calculation unit 25, which replace the first amplitude calculation unit 11 and the second amplitude calculation unit 13, are at the timing for each cycle of the reference analog sine wave signal. The amplitude is calculated by subtracting the current A / D converted value from the previous A / D converted value.

  Specifically, as shown in FIG. 7, in the first amplitude calculation unit 24 (second amplitude calculation unit 25), the first A / D conversion circuit 10 is at the timing for each cycle of the reference analog sine wave signal. The subtraction result obtained by subtracting the current A / D converted value output from the first A / D conversion circuit 10 from the previous A / D converted value output from the signal Af is the amplitude (a (cos θ) signal Sf). ) Is output.

  FIG. 8G shows the a (cos θ) signal Sf having this amplitude. Note that the signal in FIG. 8D shows the signal Se having the current A / D converted value, and the signal in FIG. 8E shows the signal Sm having the previous A / D converted value. Further, the signal in FIG. 8F is a signal indicating the timing for each period of the reference analog sine wave signal. Note that the signal in FIG. 8C is a signal Sk indicating the timing of every half cycle of the reference analog sine wave signal. Further, the signal in FIG. 8F is a signal Sj having a value that is binarized in every half period of the reference analog sine wave signal Sc.

  The configuration of the second embodiment other than that described above is the same as the configuration of the first embodiment. Therefore, in the second embodiment, substantially the same operational effects as in the first embodiment can be obtained. In particular, in the second embodiment, the first amplitude calculation unit 24 (and the second amplitude calculation unit 25) performs the current A / D conversion from the previous A / D conversion value at the timing of each cycle of the reference analog sine wave signal. Since the amplitude is calculated by subtracting the / D converted value, the DC component of the input signal can be removed.

  In the second embodiment, the first amplitude calculation unit 24 (and the second amplitude calculation unit 25) performs the current A / D conversion from the previous A / D conversion value at each cycle of the reference analog sine wave signal. The A / D converted value is subtracted. However, the present invention is not limited to this, and the current A / D converted value is compared with the current A / D converted value at every n times the cycle of the reference analog sine wave signal. A value obtained by / D conversion may be subtracted. Note that n is an integer of 1 or more. Even in this case, substantially the same operational effects as those of the second embodiment can be obtained.

The block diagram of the signal processing circuit which shows the 1st Example of this invention, and the figure which shows the waveform of each signal Resolver electrical schematic Block diagram around the first amplitude calculator Time chart Block diagram of first A / D conversion circuit Time chart FIG. 3 equivalent view showing a second embodiment of the present invention. 4 equivalent diagram

Explanation of symbols

In the drawings, 1 is a signal processing circuit, 2 is a resolver, 3 is a primary winding, 4 and 5 are secondary windings, 9 is a D / A conversion circuit, and 10 is a first A / D conversion circuit (first (A / D conversion means), 11 is a first amplitude calculation section (first amplitude calculation means), 12 is a second A / D conversion circuit (second A / D conversion means), and 13 is a second Amplitude calculator (second amplitude calculator), 14 is a rotation angle calculator, 15 is a pulse travel circuit, 16 is a first latch, 17 is an encoder, 18 is a counter, 19 is a first 'latch, and 20 is a second Latch, 21 is a third latch, 22 is a subtraction circuit, 23 is a fourth latch, 24 is a first amplitude calculator, and 25 is a second amplitude calculator.

Claims (4)

A predetermined reference analog sine wave signal is applied to the primary winding of the resolver, and the rotation angle of the rotor is detected based on two measurement analog signals output from the two secondary windings of the resolver. In the detected rotation angle detection device,
First amplitude deriving means for deriving the amplitude of a sine wave component having the same frequency as that of the reference analog sine wave signal included in the first measurement analog signal output from the one secondary winding;
Second amplitude deriving means for deriving the amplitude of a sine wave component having the same frequency as that of the reference analog sine wave signal included in the second measurement analog signal output from the other secondary winding;
The first amplitude deriving means;
First A / D conversion means for A / D converting a value obtained by integrating the first measurement analog signal every ½ period of the reference analog sine wave signal;
Based on the value A / D converted by the first A / D conversion means, a first sine wave component included in the first measurement analog signal and having the same frequency as the reference analog sine wave signal is calculated. It consists of amplitude calculation means,
The second amplitude deriving means;
Second A / D conversion means for A / D converting a value obtained by integrating the second measurement analog signal every ½ period of the reference analog sine wave signal;
A second component for calculating the amplitude of a sine wave component included in the second measurement analog signal and having the same frequency as that of the reference analog sine wave signal based on the value A / D converted by the second A / D conversion means. A rotation angle detecting device comprising an amplitude calculating means.   The first amplitude calculating means and the second amplitude calculating means multiply a value that is binarized into positive and negative values every 1/2 period of the reference analog sine wave signal by the A / D converted value, The rotation angle detection device according to claim 1, wherein the rotation angle detection device is configured to calculate an amplitude.   The first amplitude calculation means and the second amplitude calculation means subtract the current A / D converted value from the previous A / D converted value at a timing of every n times the period of the reference analog sine wave signal. The rotation angle detecting device according to claim 1, wherein the rotation angle detecting device is configured to calculate the amplitude. The first A / D conversion means and the second A / D conversion means are:
A pulse running circuit in which a plurality of inversion circuits whose inversion operation time varies depending on the power supply voltage are connected while inverting and outputting the input signal;
An A / D input voltage signal input terminal connected to a power line of each inverting circuit in the pulse traveling circuit and applying the power voltage signal as a power voltage of each inverting circuit;
Traveling position detecting means for generating data corresponding to the position of the pulse traveling circuit for each reference clock;
Means for holding data previously detected by the travel position detection means;
4. The rotation angle detection device according to claim 1, further comprising means for outputting a difference between previous data and current data as an A / D conversion result.

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