JP2017118708A - Rotation angle sensor fitting angle measurement device, and rotation angle sensor fitting angle measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotation angle sensor fitting angle measurement device capable of detecting deviation with high accuracy and high sensitivity by manually making one rotation of a work motor that becomes a measurement target.SOLUTION: In a work motor comprising a stator around which multiple coils are wound, a rotor and a rotation angle sensor, one of the multiple coils is defined as a first coil. The rotation angle sensor fitting angle measurement device comprises: a voltage detection part for detecting a first induction voltage generated in the first coil in response to rotations of the rotor; a zero-cross point generation part for generating a zero-cross point where a code of a difference between an analog signal obtained by amplifying the first induction voltage and a predetermined reference voltage is changed; a rotation angle detection part for detecting a rotation angle of the rotation angle sensor on the basis of a signal that is supplied from the rotation angle sensor; and a control part which instructs timing of detection to the rotation angle detection part and measures a phase difference between the rotation angle of the rotation angle sensor that is supplied by the rotation angle detection part, and a rotation angle of the rotor.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a technique for detecting a deviation from a reference rotation angle of a rotor in a motor when a rotation angle sensor such as a resolver is attached to the motor. Specifically, the rotation angle at which the rotation angle sensor and the motor can be detected by measuring the rotation angle based on the rotation angle sensor such as a resolver at the zero cross point of the U-phase induced voltage of the motor. The present invention relates to a sensor mounting angle measuring device and a method for detecting an angle shift between a rotation angle sensor and a motor.

  Conventionally, the U phase voltage of the motor and the Z phase signal output when the resolver output angle is 0 ° (zero degree) are observed using an oscilloscope while rotating the motor with a work motor from outside. A method of finding a phase difference (mounting angle difference) zero-cross point from a time difference between a voltage waveform and a Z-phase signal is known.

  Furthermore, in the electric motor with a position detection sensor having a stator around which a coil is wound, a rotor to which a permanent magnet is fixed, and a position detection sensor for detecting a rotation position of the rotor, the position is set on the rotor. With the detection sensor temporarily fixed, the rotor is rotated by the external power of the electric motor with the position detection sensor, and the induced voltage generated in the coil due to the rotation of the rotor is detected. A wave is extracted, a signal waveform output from the position detection sensor is detected, a deviation is calculated by comparing a signal waveform output from the position detection sensor with a fundamental wave extracted from the induced voltage waveform, and the calculation There is known a technique for adjusting the mounting position of the position detection sensor so as to eliminate the deviation, and fixing the position detection sensor to the rotor. The 009-254066 (Patent Document 1) and Japanese Patent 2002-325493 (Patent Document 2) describes such a technique.

JP 2009-254066 A JP 2002-325493 A

  In the conventional method, the U-phase voltage waveform and the Z-phase signal are observed with an oscilloscope as described above, and the phase difference corresponding to the time difference is calculated. Therefore, in the resolver mounting angle measurement, the motor with the resolver attached and the external It is necessary to connect the work motor to the work motor, rotate the work motor, and work while rotating the motor at a constant speed. Naturally, since the phase difference can be recognized only when the work motor is rotating, it is necessary to continue the rotation of the work motor even during the work of adjusting the mounting angle of the resolver. For this reason, the problem that the resolver adjustment can be a dangerous work remains.

  In Patent Document 1, the position detection sensor is fixed to the electric motor, and the rotor of the electric motor is rotated by an external motor. In Patent Document 2, the motor is rotated by the engine to rotate the rotor of the motor. Discloses a method for detecting an induced voltage generated in a coil and detecting a mounting position of a position detection sensor. That is, since the induced voltage supplied from the motor coil to which the position detection sensor is attached is detected by power, if the power supplied to the rotor of the motor is sufficient, the zero cross point where the induced voltage and zero voltage intersect is set. It is a device suitable for detecting an induced voltage (high frequency or high voltage) that exhibits a sufficient voltage change to detect, but when the external power is weak, it can be obtained, for example, by rotating it manually by an inspection operator. If the induced voltage is not enough to obtain a sufficient voltage change and it is almost flat, the zero cross point cannot be detected and it is difficult to adjust the mounting position of the position detection sensor. I don't get it.

  The present invention has been made based on the above situation, and an object of the present invention is to detect an offset angle (phase difference) between a reference angle of a work motor and a reference angle of a rotation angle sensor. By using an amplifier circuit that amplifies the voltage waveform to the set upper limit voltage and lower limit voltage, the detection accuracy and detection sensitivity of the zero cross point where the U-phase voltage waveform crosses the reference voltage can be improved. The rotation angle sensor mounting angle measuring device of the present invention is capable of detecting the offset angle with high accuracy and high sensitivity by manually rotating the work motor to be measured once while having a small-scale configuration. An object of the present invention is to provide a rotation angle sensor mounting angle measuring device and a rotation angle sensor mounting angle measuring method of the present invention.

  The present invention measures a difference between a reference angle of the work motor and a reference angle of the rotation angle sensor in a work motor having a stator around which a plurality of coils are wound, a rotor, and a rotation angle sensor. A rotation angle sensor mounting angle measuring device, wherein one of the plurality of coils is a first coil, and a first induced voltage generated in the first coil in response to rotation of the rotor Supplied from the rotation angle sensor, a voltage detection unit that detects the difference, a zero cross point generation unit that generates a zero cross point that changes the sign of the difference between the analog signal obtained by amplifying the first induced voltage and a predetermined reference voltage Based on the signal, the rotation angle detection unit that detects the rotation angle of the rotation angle sensor, and the detection timing to the rotation angle detection unit based on the zero cross point It is achieved by providing a control unit for the rotation angle detection unit measures the phase difference between the rotation angle and the rotor and the rotation angle of the rotation angle sensor supplies.

The above object of the present invention includes a zero cross point generator having an amplifier circuit for amplifying the analog signal, wherein the upper limit voltage is equal to or lower than the positive power supply voltage of the amplifier circuit, and the lower limit voltage is equal to or higher than the negative power supply voltage of the amplifier circuit. And detecting the zero cross point by amplifying the analog signal until the positive output voltage of the amplifier circuit reaches the upper limit voltage and the negative output voltage of the amplifier circuit reaches the lower limit voltage. And improving detection sensitivity
Alternatively, by including a zero cross point generation unit having an amplification circuit that performs amplification until the analog signal is converted into a rectangular wave signal,
Alternatively, a voltage generated based on all the induced voltages generated by the plurality of coils is used as the predetermined reference voltage, and a zero cross point generation unit having an amplifier circuit that amplifies the analog signal is provided, thereby further improving the effect. Is achieved.

  The present invention measures a difference between a reference angle of the work motor and a reference angle of the rotation angle sensor in a work motor having a stator around which a plurality of coils are wound, a rotor, and a rotation angle sensor. A rotation angle sensor mounting angle measuring method, wherein one of the plurality of coils is a first coil, and a first induced voltage generated in the first coil in response to rotation of the rotor And generating a zero cross point in which the sign of the difference between the analog signal obtained by amplifying the first induced voltage and a predetermined reference voltage is changed, and based on the signal supplied from the rotation angle sensor, the rotation angle sensor And detecting the rotation angle of the rotation angle sensor based on the zero cross point, and controlling the rotation angle of the rotation angle sensor and the rotation of the rotor. It is accomplished by measuring the phase difference between degrees.

The object of the present invention is to amplify the analog signal by an amplifier circuit, to set the upper limit voltage to be equal to or lower than the positive power supply voltage of the amplifier circuit, to set the lower limit voltage to be equal to or higher than the negative power supply voltage of the amplifier circuit, Amplifying the analog signal until the side output voltage reaches the upper limit voltage and the minus side output voltage of the amplifier circuit reaches the lower limit voltage, thereby improving the detection accuracy and detection sensitivity of the zero cross point. By
Alternatively, by performing amplification until the analog signal is converted into a rectangular wave signal,
Alternatively, this can be achieved more effectively by amplifying the analog signal using a voltage generated based on all the induced voltages generated by the plurality of coils as the predetermined reference voltage.

  According to the rotation angle sensor attachment angle measuring apparatus and the rotation angle sensor attachment angle measurement method of the present invention, when detecting the offset angle (phase difference) between the reference angle of the work motor and the reference angle of the rotation angle sensor, the U-phase voltage is detected. By using an amplification circuit that performs amplification to the extent that the waveform reaches the set upper limit voltage and lower limit voltage, the detection accuracy and detection sensitivity of the zero cross point at which the U-phase voltage waveform crosses the reference voltage can be improved, The rotation angle sensor mounting angle measuring device according to the present invention detects the offset angle (phase difference) with high accuracy and high sensitivity by manually rotating the work motor to be measured once in a small configuration. be able to.

FIG. 3 is a structural diagram of a brushless type (variable reluctance type) resolver. It is a figure which shows the mechanical gap angle of a motor and a resolver. 1 is an overall configuration diagram of a rotation angle sensor mounting angle measuring device system and a measurement object according to a first embodiment of the present invention. The timing relationship between the Z-phase pulse signal, the U-phase voltage waveform, the zero-cross signal, the SIN signal 41, the COS signal 42, and the angle acquisition θ generated in the rotation angle sensor mounting angle measuring device system according to the first embodiment of the present invention is as follows. FIG. In the first embodiment of the present invention, the reference voltage of the U-phase voltage, the U-phase induced voltage, the intersection of the reference voltage and the U-phase induced voltage are set at the zero cross point, and the motor rotor angle is set at the origin on the xy plane. It is explanatory drawing represented as an angle and drawn typically. It is a figure which shows the mode of offset angle (theta) 1, (theta) 2,-(theta) 8 calculated from the resolver angle in the zero cross point of the U-phase voltage waveform which vibrates centering on a reference voltage in 1st Embodiment of this invention. (A) is a figure which shows the measurement area (enclosed part) for measuring correctly the zero crossing point of the sinusoidal U-phase voltage waveform in 1st Embodiment of this invention. (B) is a figure which shows a mode that a U-phase voltage waveform becomes flat, the determination range of a zero cross point spreads, and an error expands when a measurement area is extended. (C) is a figure which shows a mode that the error of a zero cross point reduces by amplifying U phase voltage and increasing the inclination of the U phase voltage waveform of the zero cross point vicinity. It is a figure which shows a mode that the U-phase voltage waveform is limited between the maximum output voltage (upper limit voltage)-minimum output voltage (lower limit voltage) of an amplifier circuit in 1st Embodiment of this invention. It is a flowchart which shows the operation procedure of the rotation angle sensor attachment angle measuring apparatus in 1st Embodiment of this invention. It is a whole block diagram of the rotation angle sensor attachment angle measuring apparatus in 2nd Embodiment of this invention. It is an amplifier circuit which amplifies a U-phase voltage waveform using the reference voltage produced | generated based on the U-phase voltage, the V-phase voltage, and the W-phase voltage in 2nd Embodiment of this invention. It is an inverting amplifier circuit for expanding the voltage change near the zero cross of the U-phase voltage waveform in the second embodiment of the present invention. 6 is a limiter circuit and a digital level conversion circuit for a U-phase voltage waveform in the second embodiment of the present invention.

  The present invention is based on a result of comparing rotation angle data from a rotation angle sensor (for example, a resolver) attached to a workpiece motor to be measured with time information of a zero cross point of a U-phase voltage waveform of the workpiece motor. When an offset angle (deviation) between the reference angle of the work motor and the rotation angle of the rotation angle sensor is detected, an amplification circuit that performs amplification is used until the U-phase voltage waveform reaches the set upper limit voltage and lower limit voltage. As a result, it is possible to improve the detection accuracy and detection sensitivity of the zero cross point where the U-phase voltage waveform crosses the neutral point reference voltage. In particular, the rotation angle sensor mounting angle measuring device of the present invention is capable of detecting an offset angle (deviation) with high accuracy and high sensitivity by manually rotating the work motor to be measured once in a small configuration. can do.

  Hereinafter, the best mode of a rotation angle sensor mounting angle measuring apparatus and a rotation angle sensor mounting angle measuring method according to the present invention will be described with reference to the drawings.

  First, a work motor (hereinafter also simply referred to as “motor”) to which a rotation angle sensor to be measured in the present invention is attached includes, for example, a three-phase AC synchronous motor. In addition, the measurement object in the embodiment of the present invention is a rotation angle sensor, for example, a brushless type (variable reluctance type) resolver 10 as shown in FIG. The coil 11 that detects the excitation voltage that changes with the rotation of the rotor 12 has a structure such as a stator 13 that is arranged around the rotor 12 in an annular shape. As shown in FIG. 2, when the resolver 20 is attached to the motor unit 21, the resolver 0 degree position 23 of the resolver 20 is somewhat offset with respect to the reference of the work motor 0 degree position 22 in the motor part 21. An angle 24, that is, a mechanical offset angle (phase difference) between the motor and the resolver is generated. In the rotation angle sensor mounting angle measuring apparatus according to the present invention, the offset angle 24 is determined based on the rotation angle from the resolver at the time when the sign of the U-phase voltage waveform changes with respect to the reference voltage (hereinafter referred to as “zero cross point”). It is calculated by measuring data (hereinafter referred to as “resolver angle”).

  FIG. 3 shows the entire configuration of the rotation angle sensor mounting angle measuring device system and the measuring object according to the first embodiment of the present invention. A measurement target is a resolver 31 attached to a motor 32. The rotation angle sensor mounting angle measuring device system 30 (hereinafter also simply referred to as “resometer”) includes a resolver digital converter (hereinafter referred to as “RD converter”) 33, a microcomputer 34, and a zero cross point generator 35. ing.

  The resolver 30 supplies a sine wave reference signal (hereinafter referred to as “REF”) 40 as a drive signal to the resolver 31, and based on the angle of the motor 32, the resolver 31 receives a SIN signal (hereinafter simply “ SIN ”or“ Sin ”) 41 and a COS signal (hereinafter simply referred to as“ COS ”or“ Cos ”) 42 are generated and supplied to the resometer 30. The relationship between REF 40, SIN 41 and COS 42 is that the excitation signal REF 40 is input to the resolver 31, so that two detection coils (not shown) orthogonal to each other cause a rotor (not shown) of the motor 32. Two signals SIN and COS modulated according to the angle are supplied to the RD converter 33. The resolver angle can be calculated in principle from the arc tangent of SIN and COS, and is supplied to the microcomputer 34 as an angle acquisition 43 signal at the reception timing of the latch 44 signal. Further, the zero cross point generator 35 uses, as a reference voltage, a neutral point voltage obtained by adjusting the U-phase voltage 45, the V-phase voltage 46, and the W-phase voltage 47 supplied from the motor 32 by the variable resistors VRU 48a, VRV 48b, and VRW 48c. The U-phase voltage 45 can be amplified, the U-phase voltage waveform near the reference voltage can be expanded and supplied to the microcomputer 34.

  An error may occur between the U-phase, V-phase, and W-phase voltages due to differences in signal path resistance on the circuit board, but the variable resistors VRU48a, VRV48b, and VRW48c should be adjusted. Thus, the neutral point voltage can be generated accurately by making the error due to the circuit board or the like substantially zero.

  Further, since the amplification factor of the zero cross point generator 35 is very large, the waveform of a portion sufficiently away from the vicinity of the reference voltage in the U-phase voltage 45 is subjected to limiter processing to reach the set upper limit voltage and lower limit voltage. Amplification or level conversion is performed. Therefore, the U-phase voltage zero-cross signal 49 converted to a rectangular waveform having a flat portion of the upper limit voltage and the lower limit voltage is supplied to the microcomputer 34. If the upper limit voltage is set to a voltage equal to or lower than the positive power supply voltage of the amplifier circuit in the zero cross point generator 35, and the lower limit voltage is set to a voltage higher than the negative power voltage of the amplifier circuit in the zero cross point generator 35. The problem that occurs when the output voltage reaches the saturation voltage of the amplifier circuit can be avoided. In particular, when the amplifier circuit includes an operational amplifier, it is effective in avoiding a delay in response time when the output voltage reaches the saturation voltage of the amplifier circuit.

  As described above, the rising point of the zero cross 49 corresponding to the timing when the U-phase voltage 45 changes from plus to minus with respect to the reference voltage, or the falling of the zero cross 49 corresponding to the timing changing from minus to plus is used. By doing so, it is possible to easily detect the timing information of the zero-cross point of the U-phase voltage. Based on the zero cross point of the U-phase voltage 45, the microcomputer 34 supplies the signal of the latch 43 to the RD converter 33, whereby the resolver angle at the time when the rotor of the motor 32 matches the reference position or the reference angle can be acquired. it can. Based on the resolver angle at the zero cross point acquired as described above, the shift of the resolver angle (electrical angle) with respect to the reference angle of the motor 32 can be calculated.

  As for the mounting board of the resonator 30, the RD converter 33, the microcomputer 34, and the zero cross point generation unit 35 may be mounted on one board, each being mounted on a different board, and using connectors and cables. You may make it connect and input / output a signal. Also, when the work motor 32 is rotated by a drive motor (not shown) equipped with a rotary encoder without manually rotating the work motor 32, the absolute value when the motor rotor is at a reference angle, that is, an output angle of 0 °, is absolute. A timing signal for detecting the zero-cross point of the U-phase voltage may be generated by detecting that the rotor of the motor 32 rotates once by using a Z-phase pulse signal capable of detecting the angle.

  Here, the operation when the offset angle is calculated using the resonator 30 will be described. FIG. 4 shows a Z-phase pulse generated when the rotor rotation angle of the motor 32 is 0 degrees, a U-phase voltage supplied from the motor 32, a zero cross 49 that is amplified from the U-phase voltage and converted into a rectangular waveform, and a resolver 31. The timing relationship between the SIN signal 41 and the COS signal 42 supplied to the RD converter 33 and the angle acquisition θ supplied from the RD converter 33 to the microcomputer 34 is shown. The outline of the operation is as shown in FIG. 4, in which a U-phase voltage waveform for four cycles exists in a period between two Z-phase pulses, and the period corresponds to one rotation of the rotor of the motor. Further, a time point when the waveform of the U-phase voltage 45 of the motor 32 changes from a negative value to a positive value or from a positive value to a negative value with respect to the reference voltage is a zero cross point. Therefore, each zero cross point corresponds to the rising or falling timing of the zero cross 49. If the mounting position of the resolver 31 is correct, the rotor angle (corresponding to the “resolver angle”) of the work motor 32 pointed to by the resolver 31 at the time of the zero cross point is the reference angle (0 °). Has produced. For this reason, since the resolver angle at the four zero cross points does not become 0 °, it is necessary to measure for adjustment.

  Specifically, the resolver angle is measured by using the servo motor Z-phase pulse as a timing reference and the falling zero-cross point of the U-phase voltage using the neutral point N of the U-phase, V-phase, and W-phase as the voltage reference. Further, the zero-cross point data up to the fourth point can be acquired by setting the rising zero-cross point of the U-phase voltage based on the neutral point N of the U-phase, V-phase, and W-phase as the second point. At each time point of the zero cross point of the U-phase voltage, each resolver angle is calculated as an angle acquisition θ signal, but generally, the measured value of each resolver angle at each zero cross point includes an error, and therefore does not match each other. Therefore, the average value of each resolver calculated for one round is adopted as a deviation of the angle between the resolver 31 and the motor 32, that is, a measured value of the offset angle.

  In the first embodiment, since the U phase waveform of the motor has four cycles for one rotation, the zero cross points are set so that 8 points (points) per rotation exist at 45 ° intervals. Moreover, since the electrical angle of the resolver is set to 2 cycles per rotation (360 ° × 2), this corresponds to a 45 ° phase advance when converted to a mechanical angle every time one zero cross point is passed. Here, from zero cross points 1 to 4, when the passed zero cross point is n, a correct resolver angle can be calculated by subtracting a correction value of (n−1) × 45 ° from the resolver measurement angle. it can. In general, in a 12-bit RD converter, when the resolver angle reaches 180 degrees, the digital data indicating the resolver angle becomes a full bit, so the digital data is designed to be reset. In order to cope with this, at a zero cross point of 5 to 8 or less, an appropriate resolver angle is calculated by subtracting a correction value of (n-5) × 45 ° from the measurement angle of the resolver. In summary, for zero cross points 1 to 4 or less, “offset angle corresponding to zero cross point” = “resolver measurement angle” − {45 ° × (n−1)} is calculated, and zero cross points 5 to 8 or less. Then, “offset angle corresponding to zero cross point” = “resolver measurement angle” − {45 ° × (n−5)} can be calculated.

  FIG. 5 shows the rotor angle of the motor as an angle centered on the origin 51 of the xy plane 50, a reference circle 52 having a predetermined radius as a reference voltage of the U-phase voltage, and a U-phase induction that vibrates in a direction perpendicular to the circumference. It is explanatory drawing typically drawn by making each intersection of the voltage 53, the reference | standard circle | round | yen 52, and the U-phase induced voltage 53 into the zero cross points 54a, 54b, 54c, 54d, 54e, 54f, 54g, and 54h. FIG. 6 shows offset angles θ1, θ2, and θ8 calculated from resolver angles at the zero cross point of the U-phase voltage waveform that oscillates around the reference voltage. Table 1 shows an example of the calculated offset angle based on the resolver angle at each zero cross point. Also in this result, the offset angle (deviation) at each zero cross point varies, indicating that the error is large in the measurement at only one location.

When the measured value of the offset angle as shown in Table 1 is obtained, the average value of the offset angle at each zero cross point is adopted as the offset angle of the resolver to reduce the error.

  In the present invention, in order to improve the measurement accuracy of the zero cross point, the concept of converting the U-phase voltage waveform into a rectangular waveform will be described. For example, in order to accurately measure the zero cross point of the sinusoidal U-phase voltage waveform as shown in FIG. 7A, when the measurement section (the enclosed portion) is expanded, as shown in FIG. It shows how the phase voltage waveform becomes flat, that is, the error increases as the zero-cross point determination range widens. Therefore, the best method is to enlarge the slope of the zero U-phase voltage waveform, particularly near the cross point, as shown in FIG. For example, as shown in FIG. 8, the U-phase voltage waveform near the reference voltage may be amplified so that the U-phase voltage waveform exceeds the maximum output voltage-minimum output voltage of the amplifier circuit and is limited. It is to use an amplification circuit that enlarges the rate of change of the waveform as much as possible and narrows the determination range of the zero cross point. Then, as the slope of the voltage change of the U-phase voltage waveform becomes steeper, the point (timing) at which the U-phase voltage waveform intersects the reference voltage which is the neutral point N of the U-phase, V-phase, and W-phase, that is, the zero cross point Accurate measurement with few errors can be performed. Furthermore, with respect to the amplification degree, if 20 dB amplifiers are cascaded in four stages, a gain of 80 dB can be obtained in amplification degree. When the high gain amplifier circuit is used in this manner, the waveform in the period higher than the reference voltage reaches the set upper limit voltage, the waveform in the period lower than the reference voltage reaches the set lower limit voltage, and the input voltage becomes the reference voltage of the amplifier. As shown in FIG. 8, a waveform conversion may be performed by providing a binarization circuit such as a comparator circuit at the output stage of the amplifier circuit as shown in FIG. . In addition, by performing digital level conversion using a transistor on the signal supplied from the comparator, the zero-cross point of the U-phase voltage waveform corresponds to the rise and fall of the digital signal, and control of personal computers, etc. The equipment may also perform waveform conversion that can easily determine the zero-cross point of the U-phase voltage waveform.

  The operation procedure of the rotation angle sensor attachment angle measuring device 30 (hereinafter also simply referred to as “main body”) in the first embodiment will be described with reference to the flowchart shown in FIG. First, the main body 30 is installed in the vicinity of the motor 32 to be measured, the REF signal 40 is supplied to the resolver 31, and the SIN signal 41 and the COS signal 42 output from the resolver 31 are supplied to the main body 30. And the motor cable 37 for transmitting the U-phase voltage waveform, the V-phase voltage waveform and the W-phase voltage waveform from the motor 32 to the main body 30, and the main body 30 respectively (S100). The power of the main body 30 is turned on (S200). And the setting regarding the motor 32, the resolver 31, and measurement conditions for measuring is performed. Specifically, the number of pole pairs of the motor 32 (select from 2, 3, 4, 5, 6, 7, 8, 9) and the shaft angle multiplier of the resolver 31 (1, 2, 3, 4, 5, 6, 7) , 8, 9), angle unit (select from mechanical angle, electrical angle), phase difference sign (select from positive and negative), motor 0 ° reference (select from rising and falling of U-phase voltage zero cross) ), Resolver transformation ratio (select from 0.14 to 0.23, 0.18 to 0.30, 0.24 to 0.41, 0.39 to 0.66), phase difference measurement (standard, 1 (Select from circumferential average) and brake output setting (select from 24V constant voltage, 12V constant voltage, 2A constant current, 5A constant current) (S300). The brake output setting will be described later. Then, the disconnection check of the motor cable 37 and the resolver cable 36 is performed (S400). The motor cable 37 and the motor 32 are connected, and the resolver cable 36 and the resolver 31 are connected (S500). When the resolver 31 operates normally and the above setting is correct, the current rotor angle of the resolver 31 is displayed on a display screen (not shown) provided in the main body 30. Next, a measurement start button on a display screen (not shown) provided in the main body 30 is pressed to start measurement (S600). For example, when the motor 32 is manually rotated more than once, the offset angle (phase difference) of the resolver 31 is calculated and displayed on the measurement screen (S700). The resolver mounting angle is adjusted based on the displayed offset angle (phase difference) (S800). It is determined whether the measurement is performed again. If the determination result is Yes, the process returns to Step 500. If the determination result is No, the process proceeds to Step 1000 (S900). The power of the main body 30 is turned off, the motor cable 37 is detached from the main body 30 and the motor 32, the resolver cable 36 is detached from the main body 30 and the resolver 31 (S1000), and the measurement is finished. After the measurement, reattachment may be performed so that the reference angle of the resolver 31 and the reference angle of the motor 32 coincide with each other based on the offset angle.

  Regarding the brake output setting, some motors with electromagnetic brakes (not shown) employ non-excitation operation type electromagnetic brakes.When no voltage is applied, the armature is connected to the brake hub by a coil spring. As a result, the motor shaft is fixed and the brake is activated. Conversely, when a voltage is applied to the exciting coil, the armature is attracted to the electromagnet against the coil spring, and the brake is released. There is a motor that can rotate freely. In order to cope with this type of motor, the main body 30 is provided with a connection terminal for a brake cable (not shown). By setting the brake output from the setting screen of the main body 30, the electromagnetic brake of the motor can be set. It has a function that can control the power to be turned on and off.

  Next, FIG. 10 shows an overall configuration diagram of the rotation angle sensor attachment angle measuring device 60 in the second embodiment. In the second embodiment, a more specific circuit configuration than that of the first embodiment will be described for detection of the zero cross point. 3 and 10, the same reference numerals are used for common configurations. Based on the control signal 70g from the control PC 61 that executes the main program of the resolver mounting angle measuring device 60 and the control signal 70g, the interface board (hereinafter referred to as “IF board”) The programmable logic controller (hereinafter referred to as “PLC”) 63 dedicated to sequence control to be sent to 62, and the REF signal 40 is supplied to the resolver 31 attached to the work motor 32 as in the first embodiment. Then, based on the SIN signal 41 and the COS signal 42 modulated by the angle of the rotor (not shown) of the resolver 31, the rotor angle is calculated as 12-bit digital data (hereinafter referred to as “DB0 to 11”) 70a. Then, to the control PC 61 via the PLC 63 An analog / digital conversion board in which a U-phase reverse voltage waveform (hereinafter also simply referred to as “U-phase voltage waveform”), a SIN signal 41, and a COS signal 42 supplied from the work motor 32 are incorporated in the control PC 61 The IF board 62 is supplied to 61a (hereinafter referred to as “AD board”). As shown in FIG. 10, the IF board 62 includes an RD converter 62a, a buffer / gain adjustment 62b, and an IO / TTL conversion circuit 62c. Based on the control signal 70g sent from the control PC 61, the PLC 63 outputs a signal for instructing measurement start to the RD converter 62a in the IF board 62 via the IO / TTL conversion circuit 62c. Similarly, the RD converter 62a supplies the REF signal 40 to the resolver 31 attached to the work motor 32, and based on the SIN signal 41 and the COS signal 42 which are modulated by the angle of the rotor (not shown) of the resolver 31. The calculated resolver angle 12-bit digital data (BD0 to 11) 70a is supplied to the control PC 61 via the IO / TTL conversion circuit 62c and the PLC 63. Specifically, as a signal related to the start of measurement, for example, a SAMPLE signal (hereinafter referred to as “SAMPLE”) 70d for instructing the rotor angle sampling of the resolver 31; an RD signal (hereinafter referred to as “SAMPLE signal”) for instructing to read the rotor angle of the resolver 31; 70e) (denoted “RD”) are used to control the timing of measuring the resolver angle. The control PC 61 can also transmit a reset signal (hereinafter referred to as “reset”) 70 f for instructing the reset of the RD converter 62 a via the IO⇔TTL conversion circuit 62 c and the PLC 63.

  The RD converter 62a has a function of transmitting two signals related to guarantee of resolver angle data. The first is a signal LOT (hereinafter referred to as “LOT”) 70b for detecting a tracking loss state output from the RD converter 62a, and the second is a signal DOS (hereinafter referred to as “DOS”) for detecting a signal performance degradation state. The LOT signal 70b and the DOS signal 70c are signals indicating the state of the RD converter 62a. When the activation of either the LOT signal 70b or the DOS signal 70c or both is detected, the angle is Since the 12-bit digital data (DB0-11 signal) 70a, which is data, is a signal indicating that it is not guaranteed, DB11-11 guaranteed from the RD converter side 62a as resolver angle data based on the LOT signal and the DOS signal. The signal 70a can be selectively detected.

  Regarding the detection of the zero cross point, the U-phase voltage supplied from the work motor 32 is amplified at a high gain in the buffer / gain adjustment 62b, and the U-phase waveform is the upper limit set as the output range except for the vicinity of the above-described reference voltage. While the voltage and the lower limit voltage are reached, the U-phase analog signal 71a in which the change in the U-phase waveform near the reference voltage is dramatically expanded is generated, which is useful for accurately detecting the zero cross point. Then, in the AD board 61a incorporated in the control PC 61, the control PC 61 adjusts the IO⇔TTL conversion circuit 62c and the PCC 63 in accordance with the timing indicated by the zero cross point detected based on the digitally converted U-phase analog signal 71a. Through, the RD converter 62a can be instructed to read the resolver angle 12-bit digital data (BD0 to 11) 70a. As described above, the resolver angle of the resolver 31 is detected in accordance with the timing based on the zero cross point of the U-phase voltage with high accuracy, and the offset angle (deviation) is accurately calculated based on the resolver angle. it can.

  To supplement the IO⇔TTL conversion circuit 62c, the DB0-11 signal 70a, the SAMPLE signal 70d, the RD signal 70e, and the reset signal 70f are electrically isolated for noise countermeasures, and voltage level conversion is further performed. To supply to the PLC 63. Further, the IO / TTL conversion circuit 62 c may electrically isolate the LOT signal and the DOS signal, further perform voltage level conversion, and supply the result to the PLC 63. Further, supplementing the buffer / gain adjustment 62b, the REF signal 40, the SIN signal 41, the COS signal 42 and the U-phase voltage 45 are amplified and supplied to the AD board 61a incorporated in the control PC 61. good. Further, when the shaft of the drive motor 64 on which the encoder 64a is mounted and the shaft of the work motor 32 are coupled to rotate the work motor 32, a signal generated by the encoder 64a for the control PC 61 or the PLC 63 to synthesize a timing signal. For example, a Z-phase pulse may be used.

  Next, a specific amplifier circuit that amplifies the U-phase voltage waveform will be described with reference to FIGS. First, as shown in FIG. 11, by installing a neutral point N in which the U-phase voltage, V-phase voltage, and W-phase voltage supplied from the motor 32 are connected to each other via resistors R13, R14, and R15, U A reference voltage for amplifying the phase voltage is generated. The neutral point N is connected to the negative input terminal of the operational amplifier A1, and the U-phase voltage waveform is connected to the positive input terminal of the operational amplifier A1. Further, the inverting amplifier circuit 81 is formed by connecting the output terminal of the operational amplifier A1 to the positive input terminal via the resistor R12 and providing a feedback loop. The U-phase voltage waveform is supplied to the positive-side input terminal of the operational amplifier A1 via the resistor R11. Here, the operational amplifier A1 is about 20 Vp-p with respect to the U-phase voltage maximum input 122 Vp-p. The resistance values of R11 and R12 of the inverting amplifier circuit 80 are set so as to output. Since the amplification factor of the inverting amplifier circuit 81 is represented by −R12 / R11 and is about 1/6, it is sufficient to set, for example, R11 = 4.7 kΩ and R22 = 820Ω. Note that the negative input terminal of the operational amplifier A1 is grounded through a resistor R10 of 820Ω, for example.

  In the next stage, the output waveform Vout1 of the inverting amplifier circuit 81 including the operational amplifier A1 is input to the amplifier circuit 82 including the operational amplifier A2 to amplify the amplitude again, so that the negative value of the operational amplifier A2 is passed through the resistors R20 and R21. Connect to the input terminal on the side. An inverting amplifier circuit 82 is formed by connecting the output of the operational amplifier A2 to the negative input terminal via the resistor R22 and providing a feedback loop. Further, a capacitor C is arranged in parallel with the resistor R22 in the feedback loop of the inverting amplifier circuit 82 to take measures against noise and oscillation. Since the amplification factor of the inverting amplifier circuit 82 is expressed by -R22 / (R20 + R21), when it is desired to set the amplification factor to about 10 (20 dB), for example, R20, R21 = 5.1 kΩ, and R22 = 100 kΩ are set. It is enough to do. The positive input terminal of the operational amplifier A2 is grounded via, for example, a 10 kΩ resistor R23. In addition, in order to protect the negative input terminal from an excessive voltage, the negative side input terminal is grounded through two diodes having different current flow directions.

  In order to further increase the amplification factor for the U-phase voltage waveform, the amplification factor for the U-phase voltage waveform is dramatically increased by cascading the above-described inverting amplification circuits 81 and overlapping the number of stages of the inverting amplification circuits to be connected. Can be increased. As a result, the U-phase voltage waveform other than the vicinity of the reference voltage is output as a waveform superior in the measurement of the zero cross point because the change in the U-phase voltage waveform near the reference voltage is enlarged. Therefore, even when the voltage change of the U-phase voltage waveform is slow, the zero cross point can be accurately read. In order to realize the above-described high gain amplifier circuit, for example, it is possible to cascade the inverting amplifier circuit 81 as described above in four stages, and a high gain of about 80 dB (= 20 dB × 4) can be achieved. Can be obtained.

  Finally, FIG. 13 shows a limiter circuit and digital level conversion circuit 82. In the limiter circuit arranged in the previous stage, the output waveform Vout2 of the final stage of the inverting amplifier circuit 81 is input to the negative input terminal of the operational amplifier A3 via the resistor R30. Between the output terminal of the operational amplifier A3 and the negative input terminal of the operational amplifier A3, two Zener diodes ZD1 and ZD2 having opposite directions are connected in series to form a feedback loop. . By this loop, the waveform shaping can be performed so that both the plus side and the minus side are almost limited within the Zener voltage. Further, the functions of these Zener diodes ZD1 and ZD2 will be described. The Zener diode in the operational amplifier A3 limits the output voltage waveform so that it does not exceed the plus power supply voltage and does not fall below the minus power supply voltage. )I do. For this reason, the operational amplifier A3 does not saturate, and the Zener diode in the operational amplifier A3 has a rising response and a falling response of the output voltage waveform caused by the recovery time from saturation to the positive side and negative side power supply voltages. Delay can be prevented. As described above, the role of the Zener diodes ZD1 and ZD2 for avoiding the saturation of the operational amplifier A3 to the power supply voltage is useful for ensuring the accuracy of the zero cross point measurement in the multistage amplifier circuit that amplifies the motor U-phase voltage. is there. The upper limit voltage limited by the Zener diode in the operational amplifier is preferably set to be equal to or lower than the plus side power supply voltage of the operational amplifier, and the lower limit voltage is set to be higher than the minus side power supply voltage. When the operational amplifier is driven by a single power source, the lower limit voltage may be set to be equal to or higher than the GND potential.

  In the second embodiment, the Zener diode is used as a limiter for limiting the output voltage so that the operational amplifier does not saturate. However, in the case of an electronic element or electronic circuit that exhibits the same function, the Zener diode is used. It is not limited.

Further, in the digital level conversion circuit arranged in the subsequent stage, the transistor Tr with the pull-up resistor R34 connected to the collector side of the transistor Tr and the emitter side grounded is used to set the amplitude of the output waveform of the operational amplifier A3 as the power supply voltage. Level conversion is performed so as to be output to and from GND. Thus, even when the voltage change of the U-phase voltage waveform is slow using the A / D board 61a installed in the control PC 61, the zero cross point can be easily read.

10 Resolver 11 Coil 12 Rotor 13 Stator 20 Resolver (inside the workpiece)
21 Motor part (work motor)
22 Work motor 0 degree position 23 Resolver 0 degree position 24 Offset angle 30 Resolver 31 Resolver 32 Motor 33 RD converter 34 Microcomputer 35 Zero cross point generator 36 Resolver cable 37 Motor cable 40 Reference (REF)
41 SIN
42 COS
43 Angle acquisition 44 Latch 45 U phase voltage 46 V phase voltage 47 W phase voltage 48a, 48b, 48c VRU, VRV, VRW
49 Zero cross 50 xy plane 51 Origin 52 Reference circle 53 U-phase voltage 54a, 54b, 54c, 54d Zero cross point 54e, 54f, 54g, 54h Zero cross point 60 Resolver mounting angle measuring device 61 Control PC
61a Analog / digital conversion board 62 Interface board 62a RD converter 62b Buffer gain adjustment 62c IO-TTL conversion circuit 63 Programmable logic controller (PLC)
64 Drive motor 64a Encoder 70a 12-bit digital data (BD0 to 11)
70b LOT signal 70c DOS signal 70d SAMPLE signal 70e RD signal 70f Reset signal 70g Control signal 71 U-phase reverse voltage 71a U-phase analog signal 80 Inverting amplifier circuit 81 Inverting amplifier circuit 82 Limiter circuit and digital level conversion circuit

Claims (8)

In a work motor having a stator around which a plurality of coils are wound, a rotor, and a rotation angle sensor, a rotation angle sensor for measuring an angle difference between a reference angle of the work motor and a reference angle of the rotation angle sensor A mounting angle measuring device,
One coil of the plurality of coils is a first coil,
A voltage detector for detecting a first induced voltage generated in the first coil in response to rotation of the rotor;
A zero cross point generator for generating a zero cross point in which a sign of a difference between an analog signal obtained by amplifying the first induced voltage and a predetermined reference voltage is changed;
A rotation angle detector that detects a rotation angle of the rotation angle sensor based on a signal supplied from the rotation angle sensor;
Control that instructs the rotation angle detection unit to detect the detection based on the zero cross point, and measures the phase difference between the rotation angle of the rotation angle sensor supplied by the rotation angle detection unit and the rotor and the rotation angle. A rotation angle sensor mounting angle measuring device comprising a portion. A zero cross point generator having an amplifier circuit for amplifying the analog signal;
The upper limit voltage is set to be equal to or lower than the plus-side saturation voltage of the amplifier circuit, the lower limit voltage is set to be equal to or higher than the minus-side saturation voltage of the amplifier circuit, and the plus-side output voltage of the amplifier circuit is reached until the upper limit voltage is reached. The rotation angle sensor mounting angle measuring device according to claim 1, wherein the analog signal is amplified until the side output voltage reaches the lower limit voltage, thereby improving the detection accuracy and detection sensitivity of the zero cross point. .   The rotation angle sensor mounting angle measuring apparatus according to claim 1, further comprising a zero cross point generation unit having an amplification circuit that performs amplification until the analog signal is converted into a rectangular wave signal. Using a voltage generated based on all induced voltages generated by the plurality of coils as the predetermined reference voltage,
The rotation angle sensor mounting angle measuring device according to any one of claims 1 to 3, further comprising a zero cross point generation unit having an amplifier circuit for amplifying the analog signal. In a work motor having a stator around which a plurality of coils are wound, a rotor, and a rotation angle sensor, a rotation angle sensor for measuring an angle difference between a reference angle of the work motor and a reference angle of the rotation angle sensor A mounting angle measuring method,
One coil of the plurality of coils is a first coil,
Detecting a first induced voltage generated in the first coil according to the rotation of the rotor;
Generating a zero cross point in which a sign of a difference between an analog signal obtained by amplifying the first induced voltage and a predetermined reference voltage is changed;
Based on the signal supplied from the rotation angle sensor, the rotation angle of the rotation angle sensor is detected,
A rotation angle sensor mounting angle measuring method for controlling a timing of detecting a rotation angle of the rotation angle sensor based on the zero cross point and measuring a phase difference between the rotation angle of the rotation angle sensor and the rotor and the rotation angle. . Amplifying the analog signal by an amplifier circuit;
The upper limit voltage is set to be equal to or lower than the plus-side saturation voltage of the amplifier circuit, the lower limit voltage is set to be equal to or higher than the minus-side saturation voltage of the amplifier circuit, and the plus-side output voltage of the amplifier circuit is reached until the upper limit voltage is reached. By amplifying the analog signal until the side output voltage reaches the lower limit voltage,
The rotation angle sensor mounting angle measuring method according to claim 5, wherein the detection accuracy and detection sensitivity of the zero cross point are improved.   The rotation angle sensor mounting angle measuring method according to claim 5 or 6, wherein amplification is performed until the analog signal is converted into a rectangular wave signal. Using a voltage generated based on all induced voltages generated by the plurality of coils as the predetermined reference voltage,
The rotation angle sensor mounting angle measuring method according to any one of claims 5 to 7, wherein the analog signal is amplified.