JP2008289361A - Motor driving system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately detect a failure in rotation position sensors 18, 19 by a simple logic without requiring a microcomputer dedicated to monitoring. <P>SOLUTION: A common rotary shaft 16 for rotating a wheel of an electric automobile is driven by a pair of motors 12, 13, the positions of rotation of the motors are respectively detected by the individual rotational position sensors 18, 19 of resolvers, based on an output of each rotational position sensor, by an individual rotational speed detection means, rotational speeds N1, N2 are respectively detected. A subtraction means obtains a difference between rotational speeds N1, N2 of each motor detected by arithmetic operation by a rotational speed detection means, a comparison means compares this difference with a predetermined value N0. In this way, a faulty one of the two rotational position sensors, can be decided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a motor driving device that drives one rotating shaft by a plurality of motors.

  When a large amount of power is required, such as an electric vehicle, the rotating shaft connected to the wheel is driven by a pair of motors in order to increase the power. Each motor is controlled in torque or rotational speed by control means individually corresponding to each motor. The rotational position of each motor is detected by an individual rotational position sensor, and the output of those rotational position sensors is given to the control means corresponding to each motor. In a certain prior art, the failure of these rotational position sensors is detected using a microcomputer provided for monitoring the failure. Therefore, in this prior art, simplification of the configuration is desired.

  Another related technique (see Patent Document 1) includes two servo control systems that move a head for performing a component mounting operation in one direction in a horizontal plane in a component mounting apparatus for mounting an electronic component on a circuit board. Each servo control system is equipped with a servo motor, and the amount of movement of the component mounting head by each servo control system is detected by each linear scale. A configuration is disclosed in which the drive power supplies of the two servo control systems are turned off when the absolute value of the difference between the detected movement amounts exceeds a predetermined limit value. This related technology is configured to detect a failure in each servo control system by detecting a difference in the amount of movement in one direction by each servo control system as described above, so a common rotating shaft is driven by a pair of motors. Such a related technique cannot be applied to the configuration as it is, and this related technique does not provide the motivation of the present invention.

JP-A-6-131022

  SUMMARY OF THE INVENTION An object of the present invention is to provide a motor drive device that can detect a failure of a rotational position sensor that detects rotational positions of a plurality of motors that rotationally drive a common rotational shaft with a simple configuration. It is.

The present invention relates to a motor driving device that drives one rotating shaft by a plurality of motors.
A plurality of rotational position sensors for detecting the rotational position of each motor;
Rotational position change rate detecting means for detecting rotational position change rates N1, N2 of each motor based on the output of each rotational position sensor;
Comparing means for comparing the rotational position change rates N1 and N2 with each other based on the output of each rotational position change rate detecting means;
And a failure detecting means for detecting that at least one rotational position sensor is faulty when the rotational position change rates N1 and N2 differ by a predetermined value or more according to a comparison result of the comparing means. It is a drive device.

  According to the present invention, in the motor drive device that controls the drive of one rotating shaft by a plurality of electric motors, the rotational position of each motor is individually detected by the rotational position sensor, and the rotational position change rate detecting means Using the output of the position sensor, the rotational position change rates N1 and N2 of each motor are individually calculated and detected. The comparing means compares the rotational position change rates N1 and N2 detected by calculating by the rotational position change rate detecting means of each motor, finds a difference between them, and the absolute value of the difference is not less than a predetermined value N0. If there is, it is determined that at least one rotational position sensor has failed. The comparing means may determine whether the difference is not less than a predetermined positive value when the difference is positive, instead of the absolute value of the difference, or the difference is negative. In some cases, it may be determined by comparing whether the value is equal to or less than a predetermined negative value, or may be another configuration.

  Therefore, accurate failure detection of the rotational position sensor can be performed with simple logic, and occurrence of erroneous determination or determination omission can be prevented. In addition, such a configuration for detecting an abnormality in the rotational position sensor eliminates the need for a processing circuit for monitoring such as a microcomputer, and can be realized with a simple configuration, thereby reducing the cost.

  According to the present invention, for example, when the present invention is implemented in connection with an electric vehicle, the power of the pair of motors is configured to drive the wheels, for example, corresponding to the amount of depression of an accelerator pedal operated by the driver. The command means is used to derive the command value of the rotational speed or torque of the rotary shaft that drives the wheel of the electric vehicle, and the control means for each motor responds to the output of the command means in response to the output shaft. Negative feedback control is performed using the output of the rotational position sensor or the output of the rotational position change rate detection means so that each motor is individually driven and controlled. In such an electric vehicle, if the difference between the rotational position change rates N1 and N2 obtained by the comparison means is abnormal with respect to the predetermined value N0, at least one of the rotational position sensors has failed. It is determined that the motor is driven, and the drive control of the motor by each control unit is stopped by the stop unit.

  Therefore, abnormal driving of the electric vehicle is not performed, and safety is improved. The difference is abnormal with respect to the predetermined value N0 because when the absolute value of the difference is equal to or greater than the predetermined value N0, the difference is positive and is equal to or greater than the positive predetermined value N0. Or when the difference is negative and less than or equal to a negative predetermined value N0.

The present invention can be widely implemented in connection with various devices other than electric vehicles.
In the following description, the rotational position change rate may be referred to as a rotational speed.

Further, according to the present invention, the rotational position sensor includes a stator having two-phase excitation windings electrically deviated from each other by 90 degrees,
And a rotor having an output winding magnetically coupled to the excitation winding.

  According to the present invention, the rotational position change is obtained by differentiating the output from the one-phase output winding of the stator of the 2-input 1-output type resolver constituting the rotational position sensor to the rotational position change rate detecting means. The rates N1 and N2 can be detected.

The present invention includes the motor driving device,
An electric vehicle comprising: a power transmission mechanism that transmits power from a rotating shaft that is rotationally driven by the motor to wheels.

  According to the present invention, the motor drive device can be implemented in connection with an electric vehicle, but the present invention can be implemented in various other technical fields.

  According to the present invention, it is possible to accurately detect a failure of the rotational position sensor with a simple logic configuration, and to prevent erroneous determination and missing determination. Further, a monitoring processing circuit such as a microcomputer for detecting abnormality of the rotational position sensor is not required, and the present invention is realized with a simple configuration as described above, so that the cost can be reduced.

  FIG. 1 is a block diagram showing a partial electrical configuration of an embodiment of the present invention. A vehicle control circuit 2 realized by a microcomputer for driving and driving a vehicle that is an electric vehicle derives a command value corresponding to the amount of depression of an accelerator pedal 3 operated by a driver to lines 4 and 5, Each of the processing circuits 6 and 7 is realized by a microcomputer for the driving device. These processing circuits 6, 7 and R / D (Resolver / Digital) converters 8, 9 provided corresponding to the processing circuits 6, 7 constitute a controller 11.

  FIG. 2 is a block diagram showing an electrical configuration related to the controller 11 shown in FIG. A pair of motors 12 and 13 are provided to increase the output of the electric vehicle. The power transmission mechanism 15 is realized by a gear train or the like, and transmits power from a common rotating shaft 16 that is rotationally driven by the motors 12 and 13 to wheels that are driving wheels of the electric vehicle. The output shafts of these motors 12 and 13 are provided with rotational position sensors 18 and 19, respectively. The rotational position sensors 18 and 19 detect the rotational positions of the output shafts of the motors 12 and 13, respectively. The rotational position sensors 18 and 19 are realized by a resolver, for example, as shown in FIGS.

  Position signals representing the rotational positions of the output shafts from the rotational position sensors 18 and 19 are given to the R / D converters 8 and 9 of the controller 11 via lines 21 and 22, respectively, and converted into digital values. The The digital outputs of the R / D converters 8 and 9 are given to the processing circuits 6 and 7 corresponding to the rotational position sensors 18 and 19, respectively, and are derived from the rotational position sensors 18 and 19 to the lines 21 and 22, respectively. The position signal is also supplied to the other processing circuits 7 and 6, respectively, and is analog / digital converted in the processing circuits 6 and 7, respectively. Thus, the processing circuit 6 receives the output from the R / D converter 8 and the output from the rotational position sensor 19, and the other processing circuit 7 receives the output from the R / D converter 9 and the rotational position sensor 18. And output from.

  The individual command signals respectively derived from the vehicle control circuit 2 to the lines 4 and 5 are for the respective motors 12 and 13 for causing the common rotating shaft 16 to generate a rotational speed or torque that is a target rotational position change rate. This is a command signal. The individual command signals derived respectively on the lines 4 and 5 represent the rotational speed or torque that the motors 12 and 13 should share and bear. The processing circuits 6 and 7 respond to the individual command signals through the lines 4 and 5 of the vehicle control circuit 2, respectively, and are connected to the inverters 23 and 24 that drive the motors 12 and 13 corresponding to the processing circuits 6 and 7, respectively. A control signal is given through 25 and 26.

  FIG. 3 is a flowchart for explaining the operation of the processing circuit 6. Moving from step a1 to step a2, the processing circuit 6 responds to the individual command signal from the vehicle control circuit 2 via the line 4, and the rotational position of the sensor 18 given from the R / D converter 8 is the individual command signal of the line 4. The control signal obtained by the calculation is derived to the line 25 and supplied to the inverter 23 so that the rotational speed or torque represented by can be achieved. Thus, the motor 12 is rotationally driven so that the rotational speed or torque represented by the control signal from the processing circuit 6 is achieved. In this way, the motor 12 is controlled in accordance with the amount of depression of the accelerator pedal 3 operated by the driver of the electric vehicle, and the operation of the regular routine at the normal time is executed.

  In step a3, the processing circuit 6 calculates the rotational speed N1 of the motor 12 based on the signal representing the rotational position of the output shaft of the motor 12 detected by the rotational position sensor 18 from the R / D converter 8. To detect. The processing circuit 6 receives the output from the other rotational position sensor 19 and converts it into a digital value, calculates the output from the rotational position sensor 19 representing the rotational position of the output shaft of the motor 13, and The rotational speed N2 of 13 is obtained.

In step a4, the processing circuit 6 subtracts the absolute value | N1-N2 | of the difference between the detected rotational speeds N1 and N2 of the motors 12 and 13. It is compared whether or not the absolute value of this difference is equal to or greater than a predetermined value N0, that is, whether Equation 1 is satisfied.
| N1-N2 | ≧ N0 (1)

  If Equation 1 does not hold in step a4, that is, if the absolute value of the difference between the detected rotational speeds N1 and N2 of the motors 12 and 13 is less than a predetermined value N0, normal processing is performed in step a5. Thus, the rotational position sensors 18 and 19 are determined not to have malfunction and are normal, and drive control of the electric vehicle is continued.

  When it is determined in step a4 that the above-described equation 1 is satisfied, in the next step a6, it is determined that at least one of the two rotational position sensors 18 and 19 has failed. Therefore, in step a7, a fail-safe process for driving the two motors 12 and 13 is executed. That is, the processing circuit 6 stops the motor 12 without deriving the control signal for the motor 12 from the line 25.

Another processing circuit 7 corresponding to the motor 13 and the rotational position sensor 19 has the same configuration as the processing circuit 6. When the processing circuit 6 executes the fail-safe processing in step a7 of FIG. 3 described above, a signal indicating that the fail-safe processing is executed is transmitted to another processing circuit 7 via the line 27, thereby processing the processing. The circuit 7 also stops the motor 13. The processing circuit 6 stops the motor 12 when receiving a signal from the processing circuit 7 representing the execution of the same fail-safe process via the line 27. In this way, the fail-safe process is reliably executed by both the processing circuits 6 and 7, and the safety of the electric vehicle is improved. As described above, in this embodiment, since the two motors are connected to one rotating shaft, failure detection and fail-safe are possible based on the mutual relationship between the rotational positions of the motors.
The motors 12 and 13 may be three-phase induction motors, servo motors, or the like.

  FIG. 4 is a flowchart for explaining the operation of the processing circuit 6 according to the reference example of the present invention. The reference example shown in FIG. 4 is similar to the embodiment shown in FIGS. 1 to 3 described above, and corresponding parts are described using the same reference numerals. From step b1 to step b2, the routine of the motor 12 for driving the electric vehicle is controlled as in step a2 of FIG.

  In step b3, the processing circuit 6 receives the output from the rotational position sensor 18 via the R / D converter 8 and the output from the other rotational position sensor 19, respectively, and outputs the outputs from the two motors 12 and 13, respectively. The rotational position of the shaft, that is, the angles A1 and A2 of less than one rotation are detected and acquired. The rotational positions A1 and A2 detected by the rotational position sensors 18 and 19 thus obtained are subtracted to obtain a difference ΔA12 (= A1−A2). The difference ΔA12 obtained in this way is stored in the memory 31 provided in the processing circuit 6. Such a store operation of the difference ΔA12 in the memory 31 may be executed, for example, when the manufacturing of the motor driving device in the factory is completed, or in a state where the rotational position sensors 18 and 19 are operating normally, for example, It may be configured to be executed periodically.

In step b4, the processing circuit 6 determines whether or not the rotational position sensor 18 has failed by deriving an abnormal output. If the rotational position sensor 18 has failed, a signal indicating that the rotational position sensor 18 has failed is transmitted to another processing circuit 7 via the line 27, and the next step b5 Then, a signal indicating whether or not the other rotational position sensor 19 is abnormal and has failed is received from the processing circuit 7 via the line 27 and determined. If the rotational position sensor 19 has not failed, the process proceeds to the next step b6, where the rotational position A2 obtained from the normal rotational position sensor 19 and the difference ΔA12 stored in the memory 31 in advance are used. The rotational position of the motor 12 to be output by the rotational position sensor 18 is calculated to obtain the estimated value A10.
A10 = A2 + ΔA12 (2)

  In step b7, a control signal for the motor 12 is derived from the line 25 using the estimated rotational position A10, which is the estimated angle of the output shaft of the motor 12 obtained by Equation 2, and the motor 12 is individually connected via the line 4. The rotation is controlled so that the rotation speed or torque represented by the command signal is achieved. Thus, even if one of the rotational position sensors 18 fails, the motor 12 can be rotationally driven and controlled using the other normal rotational position sensor 19. The processing circuit 6 repeatedly performs the operation shown in FIG. 3, and this also applies to the processing circuit 7. Thus, in this reference example, since two motors are connected to one rotating shaft, failure detection and fail-safe are possible based on the mutual relationship between the rotational positions of the motors.

  FIG. 5 is a flowchart for explaining the operation of another processing circuit 7 in the reference example of the present invention shown in FIG. The processing circuit 7 performs the same operation as the processing circuit 6 described above. From step c1 to step c2, the routine of the motor 13 for driving the electric vehicle is controlled.

  In step c 3, the processing circuit 7 receives the output from the rotational position sensor 19 via the R / D converter 9 and the output from the other rotational position sensor 18, and receives the outputs from the two motors 12 and 13. The rotational position of the shaft, that is, the angles A2 and A1 less than one rotation are detected and acquired. The rotational positions A2 and A1 detected by the rotational position sensors 19 and 18 thus obtained are detected and acquired. The rotational positions A2 and A1 detected by the rotational position sensors 19 and 18 thus obtained are subtracted to obtain a difference ΔA21 (= A2−A1). The difference ΔA21 obtained in this way is stored in the memory 32 provided in the processing circuit 7. Such a store operation of the difference ΔA21 in the memory 32 may be executed, for example, when the manufacturing of the motor driving device in the factory is completed, or in a state where the rotational position sensors 19 and 18 are operating normally, for example, It may be configured to be executed periodically.

In step c4, the processing circuit 7 determines whether or not the rotational position sensor 19 has failed by deriving an abnormal output. If the rotational position sensor 19 has failed, a signal indicating this is transmitted to the processing circuit 6 via the line 27. In the next step c5, it is determined by receiving the signal via the line 27 from the processing circuit 6 as described above whether or not the other rotational position sensor 18 is abnormal and has failed. If the rotational position sensor 18 has failed, the process proceeds to the next step c6, where the rotational position A1 obtained from the normal rotational position sensor 18 and the difference ΔA21 stored in advance in the memory 32 are used. The rotational position of the motor 13 to be output by the rotational position sensor 19 is calculated to obtain the estimated value A20.
A20 = A1 + ΔA21 (3)

  In step c7, the rotational speed or torque represented by the individual command signal given from the vehicle control circuit 2 via the line 5 using the estimated rotational position A20, which is the estimated angle of the failed rotational position sensor 19 obtained by the equation (3). A control signal for controlling the rotation of the motor 13 is derived from the line 26 so that the above is achieved. Thus, in step c8, when both the rotational position sensors 18, 19 are normal, and when either one is abnormal and a failure occurs, and the other is normal, the drive control of the motors 12 and 13 is performed in two ways. A normal control operation similar to that when both of the rotational position sensors 18 and 19 are normal can be performed. The processing circuit 7 repeats the operation of FIG. 4, and the processing circuit 7 repeats the operation of FIG. Thus, in this reference example, since two motors are connected to one rotating shaft, failure detection and fail-safe are possible based on the mutual relationship between the rotational positions of the motors.

  FIG. 6 is a block diagram showing a part of the electrical configuration of another reference example of the present invention. This reference example is similar to the above-described embodiment shown in FIGS. 1 and 2 and the reference examples shown in FIGS. 4 and 5, and corresponding portions are denoted by the same reference numerals. It should be noted that in this reference example, one processing circuit 34 is provided, and an individual command signal similar to that described above is given from the vehicle control circuit 2 via lines 4 and 5 to this processing circuit 34. A processing circuit 34 and a memory 35 are provided. The processing circuit 34 is realized by a microcomputer or the like in the same manner as described above, and receives position signals from the rotational position sensors 18 and 19 via the R / D converters 8 and 9, respectively. The processing circuit 34 responds to the position signals of the rotational position sensors 18 and 19 so that the motors 12 and 13 achieve the rotational speed or torque indicated by the individual command signals via the lines 4 and 5, as described above. In addition, rotational drive control is performed.

  FIG. 7 is a flowchart for explaining the operation of the processing circuit 34 in the reference example shown in FIG. The reference examples shown in FIGS. 6 and 7 are similar to the above-described reference example, and the corresponding parts are described using the same reference numerals. Shifting from step d1 to step d2, the routine routine of the motors 12 and 13 for driving the electric vehicle is controlled as in step a2 of FIG.

  In step d 3, the processing circuit 34 receives the output from the rotational position sensor 18 via the R / D converter 8 and the output from the other rotational position sensor 19, and receives the outputs of the two motors 12 and 13. The rotational position of the shaft, that is, the angles A1 and A2 of less than one rotation are detected and acquired. The rotational positions A1 and A2 detected by the rotational position sensors 18 and 19 thus obtained are subtracted to obtain a difference ΔA12 (= A1−A2). The difference ΔA12 obtained in this way is stored in a memory 35 provided in the processing circuit 34. Such a store operation of the difference ΔA12 in the memory 31 may be executed, for example, when the manufacturing of the motor driving device in the factory is completed, or in a state where the rotational position sensors 18 and 19 are operating normally, for example, It may be configured to be executed periodically.

In step d4, the processing circuit 34 determines whether or not the rotational position sensor 18 has failed by deriving an abnormal output. If the rotational position sensor 18 has failed, in the next step d5, it is determined whether another rotational position sensor 19 is abnormal and has failed. If the rotational position sensor 19 has not failed, the process proceeds to the next step d6, where the rotational position A2 obtained from the normal rotational position sensor 19 and the difference ΔA12 stored in advance in the memory 35 are used. The rotational position of the motor 12 to be output by the rotational position sensor 18 is calculated to obtain the estimated value A10.
A10 = A2 + ΔA12 (4)

  In step d7, a control signal for the motor 12 is derived from the line 25 using the estimated rotational position A10, which is the estimated angle of the output shaft of the motor 12 obtained by Expression 4, and the motor 12 is individually connected via the line 4. In step d11, rotation control similar to normal is performed so that the rotation speed or torque represented by the command signal is achieved. Thus, even if one of the rotational position sensors 18 fails, the motor 12 can be rotationally driven and controlled using the other normal rotational position sensor 19.

If it is determined in step d7 that the rotational position sensor 18 has not derived an abnormal output and no failure has occurred, then in the next step d8, another rotational position sensor 19 is abnormal and has failed. Determine whether or not If the rotational position sensor 19 has failed, the process proceeds to the next step d9, where the rotational position A1 obtained from the normal rotational position sensor 18 and the difference ΔA12 previously stored in the memory 32 are used. The rotational position of the motor 13 to be output by the rotational position sensor 19 is calculated to obtain the estimated value A20.
A20 = A1-ΔA12 (5)

  In step d10, the rotational speed or torque represented by the individual command signal given from the vehicle control circuit 2 via the line 5 using the estimated rotational position A20, which is the estimated angle of the failed rotational position sensor 19 obtained by the equation (5). A control signal for controlling the rotation of the motor 13 is derived from the line 26 so that the above is achieved. Thus, in step d11, when both the rotational position sensors 18 and 19 are normal, and when either one is abnormal and a failure occurs and the other is normal, the drive control of the motors 12 and 13 is performed in two ways. A normal control operation similar to that when both of the rotational position sensors 18 and 19 are normal can be performed. The processing circuit 34 repeats the operation of FIG. As described above, in this embodiment, since two motors are connected to one rotating shaft, failure detection and fail-safe are possible based on the mutual relationship between the rotational positions of the motors.

  FIG. 8 is an electric circuit diagram showing the configuration of the rotational position sensor 18 of the reference example of the present invention. The rotational position sensor 18 basically includes a resolver main body 51, an excitation circuit 53 for exciting a one-phase excitation winding 52 provided in the resolver main body 51, and a process in which outputs of two-phase output windings 54 and 55 are given. Circuit 56.

FIG. 9 is a diagram showing the configuration of the resolver body 51 in a simplified manner. The resolver body 51 is of a 1-input, 2-output type, and the excitation winding 52 of the rotor is supplied with a sine wave voltage E12 from the excitation circuit 53 shown in FIG.
E12 = E sin ωt (6)

The output voltages E24 and E13 of the two-phase output windings 54 and 55 that are magnetically coupled to the excitation winding 52 are supplied to the processing circuit 56.
E13 = K · E sin ωt · sin θ (7)
E24 = K · E sin ωt · cos θ (8)
E is a voltage, K is a transformation ratio, and θ is a rotation angle representing a rotational position. t represents time.

  In the excitation circuit 53, the output of the power source 58 is given to the oscillation circuit 59, and the oscillation frequency signal having the angular frequency ω is given to the excitation winding 52 through the buffer 60 as shown in FIG. The rotational speed of the output shaft of the motor 12 can be obtained by differentiating the output of either one of the output windings 54 and 55.

  In the processing circuit 56, the outputs of the output windings 54 and 55 are given from the amplifier circuits 61 and 62 to the both-wave rectifier circuits 63 and 64, and are subjected to full-wave rectification, and are smoothed by the low-pass filters 65 and 66. 67 and 68, and is DC amplified and led to line 21 as DC voltages Vy and Vx. The output voltage E13 of the amplifying circuit 61 is as shown in Equation 7 above, and the output voltage E24 of the amplifying circuit 62 is as shown in Equation 8.

The signals applied to the excitation winding 52 from the buffer 60 are input to the both-wave rectifier circuits 63 and 64, so that the both-wave rectifier circuits 63 and 64 receive sin ωt = A, where A is a predetermined value. When the amplitudes of both signals E13 and E24 are monitored at the timings t = t1, t2,..., Vy = A · K · E sin θ (9)
Vx = A · K · E cos θ (10)
It becomes. Since there is a relationship of sin ² θ + cos ² θ = 1, when calculating the sum S of squares of the output signals,
S = (A · K · E sin θ) ² + (A · K · E cos θ) ²
= (A ・ K ・ E) ² (11)
The resolver abnormality can be detected by determining whether or not the value S falls within the tolerance.

  FIG. 10 is a diagram showing a waveform depending on the rotation angle θ representing the detection position at the timings t1, t2,... Of the output voltages E13, E24 of the output windings 54, 55 of the stator. Thus, the rotation angle θ can be detected by the DC voltages Vy, Vx corresponding to the output voltages E13, E24 at the timings t1, t2,. The output of the line 21 is converted into a digital value by the R / D converter 8 of FIG.

FIG. 11 is a flowchart showing a failure detection operation of the rotational position sensor 18 by the processing circuit. From step f1 to step f2, the output of the rotational position sensor 18 via the R / D converter 8 is received, and in the next step f3, the DC voltages Vx and Vy are monitored at predetermined periodic timings t1 and t2. Then, the sum S expressed by the above-described equation 11 is calculated. In step f5, the sum S is within a predetermined range S1 to S2, that is, S1 ≦ S ≦ S2 (12)
Or whether it is out of the range of Equation 12. If it is within the range of Expression 12, it is determined in Step f6 that the rotational position sensor 18 is normal, and if it is out of the range, it is determined in Step f7 that the rotational position sensor 18 is faulty. In this way, the failure detection operation relating to the series of rotational position sensors 18 is terminated at step f8. Such an operation is repeated.

  FIG. 12 is a diagram showing a simplified configuration of the resolver body 21 in the rotational position sensor 18 of the reference example of the present invention. The resolver body 21 has a two-input, two-output type, and the stator is provided with an A-phase excitation winding 41 and a B-phase excitation winding 42 that are perpendicular to each other, and these two-phase excitation windings are provided. The windings 41 and 42 are arranged so as to be electrically shifted from each other by 90 degrees. The rotor includes a C-phase output winding 44 and a D-phase output winding 45. These output windings 44 and 45 are magnetically coupled to the excitation windings 41 and 42, and these output windings. 44 and 45 are arranged to be electrically deviated from each other by 90 degrees. The output ec of the C-phase output winding 44 is derived from the rotary transformer 47 in a brushless manner. Similarly, the output ed of the D-phase output winding 45 is derived from the rotary transformer 48 in a brushless manner and deviates from the voltage ec described above by 90 degrees.

FIG. 13 is a waveform diagram for explaining the operation of the rotational position sensor 18 which is the resolver shown in FIG. The angle formed by the A-phase stator winding 41 and the C-phase rotor winding 44 is θ, and the sine wave voltage ea shown in FIG. When the cosine wave voltage eb is applied to the stator winding 42, the voltage ec shown in FIG. 13B is induced in the C-phase rotor winding 44.
ea = E _m sin ωt (13)
eb = E _m cos ωt (14)
ec = E _m sin (ωt + θ) (15)

  Em is the amplitude value of these sine wave voltages, ω is each frequency of the sine wave voltage, and t represents time.

  This voltage ec is detected brushlessly through the rotor transformer 47 as described above. The phase difference represented by the angles θ1 and θ2 of the voltage ec (generally indicated by θ as described above) corresponds to the rotational position of the output winding 44 and hence the output shaft of the motor 12. The rotational speed of the output shaft of the motor 12 can be obtained by differentiating the output voltage ec of the C-phase output winding 44. The outputs of the output windings 44 and 45 in FIG. 12 are given to the processing circuit 56 shown in FIG. 8, and the other configurations are the same as those in the reference example described above.

  FIG. 14 is a diagram showing a simplified configuration of the resolver body 72 in the rotational position sensor 18 according to the embodiment of the present invention. The configuration of the resolver body 72 in FIG. 14 is similar to the configuration of the resolver body 71 in FIGS. 12 and 13 described above, and the stator includes an A-phase excitation winding 41 and a B-phase excitation winding 42 that are perpendicular to each other. The same sinusoidal voltages ea and eb as described above are applied to the excitation windings 41 and 42, respectively. The rotor 43 is fixed to the output shaft of the motor 12, and the C-phase output winding 44 is fixed to the rotor. The output of the C-phase output winding 44 is derived as a voltage ec from the rotary transformer 45 in a brushless manner. The rotational speed of the output shaft of the motor 12 can be obtained by differentiating the output voltage ec of the C-phase output winding 44.

  The rotational position sensor 18 of FIG. 14 can be implemented in the above-described embodiment of FIGS.

  Although the above description has been made mainly with respect to the rotational position sensor 18, the same configuration is applied to the other rotational position sensor 19. In each reference example of FIGS. 8 to 13, individual failure detection of the rotational position sensor 18 or 19 can be easily performed.

The following embodiments are possible for the present invention.
(1) In a motor drive device that drives one rotating shaft by a plurality of motors,
A rotational position sensor that is provided in each motor and outputs two signals having different phases relating to the rotational position of the motor;
A motor drive apparatus comprising: failure detection means for detecting a failure of the rotational position sensor based on a relationship between the two signals having different phases in each motor.

  A rotational position sensor is provided for each of a plurality of motors that drive one rotational shaft, each rotational position sensor outputs two signals having different phases, and the failure detection means includes two different phases from each rotational position sensor. A failure of the rotational position sensor is detected based on the signal relationship. Thus, it is possible to identify and detect a rotational position sensor in which a failure has occurred among a plurality of rotational position sensors used in the motor drive device.

(2) In a motor drive device that drives one rotating shaft by a plurality of motors,
A plurality of rotational position sensors for detecting the rotational position of each motor;
Storage means for storing the mutual displacement amount of the rotational position detected by each rotational position sensor;
A failure detection means for detecting a failure of each rotational position sensor;
When it is detected by the failure detection means that one rotational position sensor is malfunctioning, the malfunction is detected by the rotational position detected by the other rotational position sensor and the mutual shift amount stored in the storage means. And a calculating means for calculating and estimating a detection position of the rotational position sensor.

(3) Each rotational position sensor is
Output two signals with different phases related to the rotational position of the motor,
The failure detection means detects a failure of the rotational position sensor based on the relationship between the two signals having different phases of each rotational position sensor.

  The failure detection means detects whether the two rotational position sensors that rotate the same axis with multiple motors and individually detect the rotational position of each motor have failed. For example, during manufacture of the motor drive device, a deviation amount, which is a difference in detection angle of each output of the rotational position sensor, is detected by the deviation amount detection means and stored in the memory in advance, and the failure detection means detects a failure of the rotational position sensor. In this case, the detection position of the rotational position sensor in which the failure has occurred is estimated by calculating by the calculation means based on the output of the other rotational position sensor operating normally and the amount of deviation stored in the memory. Based on the detected position of the rotational position sensor thus estimated, the motor corresponding to the rotational position sensor in which the failure has occurred is rotationally driven and controlled by the control means corresponding to the rotational position sensor in which the failure has occurred. Therefore, even if the rotational position sensor fails, the motor drive device does not stop, the motor drive control process can be continued, and the control performance of a plurality of motors can be maintained. Further, the failure rate of the entire system of the motor drive device due to the failure of the rotational position sensor can be reduced.

  The failure detection means for detecting the failure of the rotational position sensor can detect the rotational position sensor in which the failure has occurred based on the relationship between two signals having different phases from the rotational position sensor.

(4) The rotational position sensor
A rotor having a single-phase excitation winding;
A stator having two-phase output windings that are magnetically coupled to the excitation windings and are electrically offset from each other by 90 degrees;
The failure detection means detects that the rotational position sensor is defective when the sum of the squares of the output voltages of the output windings is outside a predetermined range.

  The 1-input 2-output type resolver constituting the rotational position sensor has a predetermined phase when the sum of the squares of the output voltages from the two-phase output windings of the stator is a sine wave or the like supplied to the excitation winding of the rotor. When the rotational position sensor is out of the predetermined range at the timing, it is detected that the rotational position sensor is out of order.

(5) The rotational position sensor
A stator having two-phase excitation windings electrically deviated from each other by 90 degrees;
A rotor having two-phase output windings that are magnetically coupled to the excitation windings and electrically offset from each other by 90 degrees;
The failure detection means detects that the rotational position sensor is defective when the sum of the squares of the output voltages of the output windings is outside a predetermined range.

  The two-input two-output type resolver constituting the rotational position sensor has a predetermined phase such as a sine wave supplied to the excitation winding of the rotor when the sum of the squares of the output voltages from the two-phase output windings of the stator. When the rotational position sensor is out of the predetermined range at the timing, it is detected that the rotational position sensor is out of order.

It is a block diagram which shows the one part electrical structure of one Embodiment of this invention. It is a block diagram which shows the electrical structure relevant to the controller 11 shown by FIG. 3 is a flowchart for explaining the operation of a processing circuit 6; It is a flowchart for demonstrating operation | movement of the processing circuit 6 of the reference example of this invention. 6 is a flowchart for explaining the operation of another processing circuit 7 in the reference example of the present invention shown in FIG. It is a block diagram which shows a part of electrical structure of the other reference example of this invention. It is a flowchart for demonstrating operation | movement of the processing circuit 34 in embodiment shown by FIG. It is an electric circuit diagram which shows the structure of the rotational position sensor 18 of the reference example of this invention. It is a figure which simplifies and shows the structure of the resolver main body 51. It is a figure which shows the waveform depending on rotation angle (theta) showing the detection position in timing t1, t2, ... of output voltage E13, E24 of the output windings 54 and 55 of a stator. It is a flowchart which shows the malfunction detection operation | movement of the rotation position sensor 18 by a processing circuit. It is a figure which simplifies and shows the structure of the resolver main body 21 in the rotational position sensor 18 of the other reference example of this invention. It is a wave form diagram for demonstrating operation | movement of the rotational position sensor 18 which is a resolver shown by FIG. It is a figure which simplifies and shows the structure of the resolver main body 72 in the rotational position sensor 18 of one Embodiment of this invention.

Explanation of symbols

2 Vehicle control circuit 6, 7, 34 Processing circuit 8, 9 R / D converter 12, 13 Motor 15 Power transmission mechanism 16 Rotating shaft 18, 19 Rotation position sensor 31, 32, 35 Memory

Claims (3)

In a motor drive device that drives one rotating shaft by a plurality of motors,
A plurality of rotational position sensors for detecting the rotational position of each motor;
Rotational position change rate detecting means for detecting rotational position change rates N1, N2 of each motor based on the output of each rotational position sensor;
Comparing means for comparing the rotational position change rates N1 and N2 with each other based on the output of each rotational position change rate detecting means;
And a failure detecting means for detecting that at least one rotational position sensor is faulty when the rotational position change rates N1 and N2 differ by a predetermined value or more according to the comparison result of the comparing means. Drive device. The rotational position sensor includes a stator having two-phase excitation windings electrically deviated from each other by 90 degrees,
The motor driving device according to claim 1, further comprising: a rotor having an output winding magnetically coupled to the excitation winding. The motor driving device according to claim 1 or 2,
An electric vehicle comprising: a power transmission mechanism that transmits power from a rotating shaft that is rotationally driven by the motor to wheels.

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