JP6222447B2 - Electric vehicle motor control device - Google Patents

Description

  The present invention relates to a motor control device for an electric vehicle, and more particularly to a motor control device that drives and controls a motor by exciting a stator according to a rotation angle of a rotor.

In order to improve the efficiency of an engine vehicle equipped with an engine as a conventional traveling power source, a hybrid electric vehicle equipped with a motor as a traveling power source in addition to the engine, or a motor as a traveling power source instead of the engine And the like (hereinafter collectively referred to as electric vehicles).
Examples of the motor mounted on the electric vehicle include a permanent magnet type synchronous motor. In this type of motor, it is necessary to excite the coils of each phase of the stator in accordance with the rotation angle of the rotor provided with the permanent magnets. Is provided.

  Due to the diversification of technology, some types of electric vehicles have a type in which front wheels and rear wheels are individually driven by motors. For example, in the electric vehicle disclosed in Patent Document 1, a rotation angle sensor is provided for each of the front wheel motor and the rear wheel motor, and the rotor of the corresponding motor is based on the rotation angle signals output from these rotation angle sensors. The rotation angle is determined, and the excitation of the stator is controlled based on the determination result.

JP 2006-197777 A

  As described above, in order to properly operate the front-wheel and rear-wheel motors by exciting the stator according to the rotation angle of the rotor, it is necessary to provide rotation angle sensors for the respective motors. When a failure occurs in any of the rotation angle sensors, the motor on that side cannot appropriately control the excitation of the stator. When running at a high speed in this state, the motor and the inverter are damaged. Therefore, there is a problem that it is necessary to switch to the limp home mode in which the vehicle speed is limited, and thereafter normal running cannot be continued.

  The present invention has been made to solve such problems, and the object of the present invention is to accurately determine the rotation angle of the rotor even when a rotation angle sensor that detects the rotor rotation angle of the motor has failed. An object of the present invention is to provide a motor control device for an electric vehicle that can discriminate and appropriately control the excitation of the stator and can continue normal running.

In order to achieve the above object, the invention of claim 1 is provided in a first motor for driving a front wheel of a vehicle, a second motor for driving a rear wheel of the vehicle, and a first motor. A first signal output means for outputting a first rotation change signal that changes with rotation of the motor and a first reference signal that indicates a specific reference angle of the first motor; and a second motor, Second signal output means for outputting a second rotation change signal that changes with rotation of the second motor and a second reference signal indicating a specific reference angle of the second motor; and first signal output means Failure diagnosis means for diagnosing at least one of the output function of the first rotation change signal by the second output function and the output function of the second rotation change signal by the second signal output means, the first rotation change signal, and the first reference First rotation angle for determining the rotation angle of the first motor based on the signal And another unit, a second rotation angle determination means for determining the rotational angle of the second motor based on the second rotation change signal and the second reference signal comprises a first rotation angle determining means, failure When a failure determination is made for the first signal output means by the diagnosis means, the rotation angle of the first motor is estimated based on the second rotation change signal and the first reference signal, and the second rotation When the angle determination means makes a failure determination for the second signal output means by the failure diagnosis means, the rotation angle of the second motor is estimated based on the first rotation change signal and the second reference signal. It is characterized by doing.

The invention according to claim 2 is characterized in that the failure diagnosis means makes a diagnosis by comparing the first rotation change signal and the second rotation change signal.
According to a third aspect of the present invention, the first motor and the second motor are provided with speed reducers having different reduction ratios, and the first rotation angle determining means is a failure determination of the first signal output means by the failure diagnosis means. The second rotation change signal is corrected based on the ratio between the reduction ratio of the first motor and the reduction ratio of the second motor, and based on the corrected second rotation change signal and the first reference signal. The rotation angle of the first motor is estimated, and the second rotation angle determination means uses the first rotation change signal as the reduction ratio of the first motor when the failure diagnosis means determines the failure of the second signal output means. Correction based on the ratio of the reduction ratio of the second motor and the second motor, and the rotation angle of the second motor is estimated based on the corrected first rotation change signal and second reference signal.

According to a fourth aspect of the present invention, when the first rotation angle determination means determines the failure of the first signal output means by the failure diagnosis means, the vehicle is driven forward or backward by driving the first motor and the second motor. On the other hand, the phase of the first reference signal is corrected based on the first correction amount set in advance corresponding to the backlash of the speed reducer of the first motor, and the second rotation change signal and after correction The rotation angle of the first motor is estimated on the basis of the first reference signal, and the second rotation angle determination means is configured to detect the first motor and the second motor when the failure diagnosis means determines the failure of the second signal output means. The phase of the second reference signal is set based on the second correction amount set in advance corresponding to the backlash of the speed reducer of the second motor, either in the forward or backward movement of the vehicle by the driving of the second motor. Correct the first rotation change signal and the corrected And estimates the rotation angle of the second motor based on the second reference signal.

According to a fifth aspect of the present invention, the first rotation angle determination means integrates the second rotation change signal and determines the second rotation change signal when the failure diagnosis means determines the failure of the first signal output means. The integrated value is reset at the output timing of the first reference signal, the rotation angle of the first motor is estimated based on the integrated value at the time of reset, and the second rotation angle determination means is a second signal by the failure diagnosis means. At the time of failure determination of the output means, the first rotation change signal is integrated, the integrated value of the first rotation change signal is reset at the output timing of the second reference signal, and the second value is calculated based on the integrated value at the time of reset. The rotation angle of the motor is estimated.

According to a sixth aspect of the present invention, there is provided slip determination means for determining slip generated on a front wheel or a rear wheel of a vehicle, and the first rotation angle determination means is used when the failure diagnosis means determines a failure of the first signal output means. When the slip determination is made by the slip determination means, the reset timing of the integrated value of the second rotation change signal is corrected based on the first reference signal after recovery from the slip, and the second rotation angle determination means When slip determination is made by the slip determination means at the time of failure determination of the second signal output means by the diagnosis means, the reset timing of the integrated value of the first rotation change signal based on the second reference signal after recovery from the slip It is characterized by correcting.

According to the electric vehicle motor control apparatus of the first aspect of the present invention, the first motor and the second motor rotate synchronously via the road surface while the vehicle is traveling. For this reason, the rotation change signal that changes as the motors rotate is correlated not only with the rotation of the own motor but also with the rotation of the counterpart motor.
According to the present invention, when a failure determination is made that there is an abnormality in the rotation change signal output function of the first signal output means or the second signal output means, the rotation change signal of its own signal output means is replaced. Then, the rotation change signal from the signal output means on the other side is used. Therefore, based on the rotation change signal of the other party and the reference signal of its own signal output means (indicating the specific reference angle of its own motor), the rotation angle of the motor is determined even when the front wheel or the rear wheel slips. It can be estimated. For this reason, it is possible to accurately estimate the rotation angle of the motor even when the failure of the signal output means occurs.

According to the electric vehicle motor control apparatus of the second aspect of the invention, the failure diagnosis of the signal output means can be accurately performed by comparing the first rotation change signal and the second rotation change signal.
According to the electric vehicle motor control apparatus of the third aspect of the present invention, the rotation change signal is corrected based on the ratio between the reduction ratio of the first motor and the reduction ratio of the second motor. The present invention can also be applied to a vehicle having a different.

According to the electric vehicle motor control apparatus of the fourth aspect of the invention, the first correction amount or the second correction amount corresponding to the backlash of the reduction gear of each motor when the vehicle is either forward or backward. Since the phase of each reference signal is corrected based on the correction amount, the rotation angle of each motor can be estimated accurately.
According to the motor control device for an electric vehicle of the invention of claim 5, if a failure occurs in any of the signal output means, if the reset timing of the rotation change signal on the counterpart side is corrected based on the reference signal on the failure side, The phase of the rotation change signal after correction corresponds to the phase of the motor on the failure side. Therefore, regardless of the presence or absence of slip, the rotation angle of the motor on the failure side can be accurately estimated from the corrected rotation change signal.

According to the electric vehicle motor control apparatus of the sixth aspect of the invention, when the front wheel or the rear wheel slips, the reset timing of the rotation change signal on the counterpart side is corrected based on the reference signal on the fault side. And the phase shift between the motor on the failure side are compensated. Therefore, regardless of the presence or absence of slip, the rotation angle of the motor on the failure side can be accurately estimated from the corrected rotation change signal.

1 is an overall configuration diagram illustrating an electric vehicle to which a motor control device of an embodiment is applied. It is a time chart which shows the production | generation condition of the rotation angle signal based on the pulse signal and the reference signal at the time of normal and failure of a front resolver. It is a flowchart which shows the rotation angle signal generation routine which a front and rear controller perform. It is explanatory drawing which shows the meshing state of the gear of the reduction gear in advance. It is explanatory drawing which similarly shows the meshing state of the gear of the reduction gear in reverse.

Hereinafter, an embodiment of an electric vehicle motor control apparatus embodying the present invention will be described.
FIG. 1 is an overall configuration diagram showing an electric vehicle to which the motor control device of this embodiment is applied.
The electric vehicle 1 of the present embodiment is configured to travel by driving the front wheels 2f and the rear wheels 2r individually by two motors Mf and Mr mounted as driving power sources. Hereinafter, the motor that drives the front wheels 2f is referred to as a front motor Mf (first motor), and the motor that drives the rear wheels 2r is referred to as a rear motor Mr (second motor).

The front motor Mf is connected to the left and right front wheels 2f via a speed reducer 3f, a differential device 4f and a drive shaft 5f. After the driving force of the front motor Mf is converted by the speed reducer 3f at a predetermined speed reduction ratio Rf, It is distributed to the left and right front wheels 2f via the moving device 4f. Similarly, the rear motor Mr is connected to the left and right rear wheels 2r via the speed reducer 3r, the differential device 4r and the drive shaft 5r. After the driving force of the rear motor Mr is converted by the speed reducer 3r at a predetermined speed reduction ratio Rr, the difference is obtained. It is distributed to the left and right rear wheels 2r via the moving device 4r.
The front motor Mf is connected to the front controller 7f via a three-phase power line 6f, and the front controller 7f is connected to the traveling battery 9 via a power line 8f. Similarly, the rear motor Mr is connected to the rear controller 7r via a three-phase power line 6r, and the rear controller 7r is connected to the traveling battery 9 via a power line 8r.

The front and rear controllers 7a and 7r have both a motor Mf and Mr control function and an inverter function, respectively. For example, the front and rear controllers 7a and 7r set target outputs of the respective motors Mf and Mr according to the driver's accelerator operation amount, the traveling state of the vehicle 1, and the like. Then, the vehicle 1 is driven by the driving force generated by controlling the power of the motors Mf and Mr based on the target output, or the motors Mf and Mr are regeneratively controlled when traveling on a downhill road, etc. Or charge to 9.
Since input / output of electric power between the motors Mf, Mr and the traveling battery 9 requires AC / DC conversion and step-up / down pressure, the front and rear controllers 7a, 7r also perform these processes. In addition, it is not restricted to this structure, For example, you may make it perform an inverter function with a dedicated inverter.

  The front and rear motors Mf and Mr are configured as, for example, permanent magnet type synchronous motors, and generate driving force by exciting the coils of each phase of the stator according to the rotation angle of the rotor provided with the permanent magnets. In order to properly excite the stator, the front and rear controllers 7a and 7r need to recognize the rotation angles of the motors Mf and Mr. For this reason, in the technique of Patent Document 1, the front and rear motors are each provided with a rotation angle sensor capable of detecting the rotation angle of the rotor. As a result, there was a problem that normal excitation could not be continued and normal running could not be continued.

In view of such problems, the present inventor has focused on the fact that the front motor Mf and the rear motor Mr rotate synchronously via the road surface while the vehicle 1 is traveling.
That is, both the motors Mf and Mr rotate synchronously with the front wheel 2f or the rear wheel 2r via the respective speed reducers 3f and 3r, and the front wheel 2f and the rear wheel 2r rotate synchronously via the road surface. For this reason, signals (pulse signals (first rotation change signal, second rotation change signal) described later, and thus rotation angle signals SIGf, SIGr) output from the rotation angle sensors of the motors Mf, Mr are It correlates not only with the rotation of the rotor of its own motor Mf, Mr, but also with the rotation of the rotor of the counterpart motor Mf, Mr. Therefore, when a failure occurs in one of the rotation angle sensors, the detection signal from the other rotation angle sensor is corrected based on the ratios Rr / Rf, Rf / Rr of the reduction ratios Rf, Rr of both motors Mf, Mr. Thus, it can be used as an index for estimating the rotation angle of one of the motors Mf and Mr. Hereinafter, specific processing contents will be described.

  In the present embodiment, a front resolver 11f (first signal output means) is built in the front motor Mf as a rotation angle sensor, and a rear resolver 11r (second signal output means) is built in the rear motor Mr as a rotation angle sensor. . For example, the resolvers 11f and 11r output a pulse signal for each minute rotation angle (for example, 1 °) of the rotor and a reference signal for each specific reference angle (for example, 45 °). The front controller 7f and the rear controller 7r sequentially integrate the pulse signals input from the resolvers 11f and 11r, and reset (= 0) the integrated pulse signals at 45 ° timing when the reference signal is input.

As a result, as shown in FIG. 2, the rotation angle signal SIG f sawtooth is generated by the processing of the front controller 7f, the rotation angle signal SIG r sawtooth are generated by the processing of the rear controller 7r. The front controller 7f and the rear controller 7r determine the rotation angle of the rotor of the corresponding motor Mf, Mr from the integrated value of the current pulse signal, and then determine the excitation timing of the stator based on the rotation angle (first) 1 rotation angle discrimination means, second rotation angle discrimination means).
Hereinafter, for convenience of description, the output of the front resolver 11f may be referred to as a first pulse signal and a first reference signal, and the output of the rear resolver 11r may be referred to as a second pulse signal and a second reference signal. .

  The first pulse signal and the first reference signal from the front resolver 11f are also input to the rear controller 7r, and the second pulse signal and the second reference signal from the rear resolver 11r are also input to the front controller 7f. Each controller 7f, 7r outputs rotation angle signals SIGf, SIGr corresponding to its own motor Mf, Mr based on detection information inputted from the other resolver 11f, 11r when a failure occurs in its resolver 11f, 11r. The rotation angle of the rotor is generated and estimated (first rotation angle determination means, second rotation angle determination means).

The failure of the resolvers 11f and 11r assumed in the present embodiment is an abnormality in the output function of the pulse signal. For this reason, the front controller 7f and the rear controller 7r have a function for diagnosing failures of their own resolvers 11f and 11r ( Fault diagnosis means).
As described above, since the front motor Mf and the rear motor Mr rotate synchronously via the road surface, the pulse signals output from the resolvers 11f and 11r are the ratios of the reduction ratios Rf and Rr of the reduction gears 3f and 3r. Correcting based on Rf / Rr results in a substantially synchronized waveform. Therefore, for example, when the difference between the periods of the corrected first and second pulse signals is equal to or greater than a predetermined determination value, it can be considered that any of the resolvers 11f and 11r is out of order. On the other hand, in each resolver 11f, 11r, since the pulse signal and the reference signal are always output at a constant ratio regardless of the rotational speed of the motors Mf, Mr, the resolver 11f, 11r on the side where the correlation is lost is pulsed. It can be assumed that the signal output function is abnormal.

Note that the failure of the resolvers 11f and 11r may be diagnosed only from the ratio between the individual pulse signals and the reference signal without comparing the pulse signals of the resolvers 11f and 11r.
Here, when slip occurs in the front wheel 2f or the rear wheel 2r, even if both the front resolver 11f and the rear resolver 11r are normal, the periods of the pulse signals do not coincide with each other. Therefore, it is desirable to perform the above-described failure diagnosis in a state where the vehicle is traveling stably without causing a slip or the like.

  As a result of the above-described failure diagnosis, when the failure determination is made for the own resolvers 11f and 11r, the front controller 7f and the rear controller 7r execute a failure response signal generation routine shown in FIG. Since the contents of the routine are common to the front controller 7f and the rear controller 7r, an example will be described in which the front controller 7f makes a failure determination of the front resolver 11f and executes a failure response signal generation routine. Therefore, in this case, the first pulse signal of the front resolver 11f is not reliable, and only the first reference signal can be used.

First, in step S2, it is determined whether or not the vehicle 1 is moving forward. This determination is made based on detection information from a wheel speed sensor (not shown) provided on the front wheel 2f or the rear wheel 2r. When the determination is Yes (positive), the process proceeds to step S4. In step S4, similarly to the processing of the rear controller 7r, a sawtooth rotation angle signal SIGr is generated based on the second pulse signal and the second reference signal input from the rear resolver 11r. Then, the rotation angle signal SIGr is multiplied by the ratio Rr / Rf of the reduction ratio Rr of the reduction gear 3r of the rear motor Mr and the reduction ratio Rf of the reduction gear 3f of the front motor Mf, whereby the saw shown in FIG. A wavy rotation angle signal SIGf is generated. The cycle of the rotation angle signal SIGf corresponds to the rotation cycle of the rotor of the front motor Mf.
The front controller 7r may input the rotation angle signal SIGr generated by the rear controller 7r without generating the rotation angle signal SIGr.

Here, although the front motor Mf and the rear motor Mr rotate synchronously, the phases of the rotors, in other words, the output timings of the reference signals of each other do not match. Since the rotation angle signal SIGf based on the rotation angle signal SIGr is reset at the output timing of the second reference signal on the rear side, it does not correspond to the phase of the rotor of the front motor Mf as it is.
Therefore, the rotation angle signal SIGf (= integrated value of the pulse signal) is reset at the output timing of the first reference signal from the front resolver 11f in the first period when the generation of the rotation angle signal SIGf is started. Thereby, integration of the pulse signal is started in synchronization with the first reference signal, and the phase of the rotation angle signal SIGf corresponds to the phase of the rotor of the front motor Mf. In subsequent cycles, the rotation angle signal SIGr is corrected based on the ratio Rr / Rf without using the first reference signal, and corresponds to the rotor phase of the front motor Mf (at the output timing of the first reference signal). A rotation angle signal SIGf (which is reset) can be generated.

  In the subsequent step S6, it is determined whether or not a slip has occurred in the front wheel 2f or the rear wheel 2r based on detection information from the wheel speed sensor (slip determination means). For example, the slip determination may be made when the difference between the average value of the left and right wheel speeds of the front wheel 2f and the average value of the left and right wheel speeds of the rear wheel 2r exceeds a predetermined determination value. When the determination in step S6 is No (negative), the routine is terminated as it is.

  When slip does not occur, the front wheel 2f and the rear wheel 2r are almost completely synchronously rotated. Therefore, the rotation angle signal SIGf generated in step S4 can be regarded as corresponding to the phase of the rotor of the front motor Mf. Therefore, the rotation angle of the rotor of the front motor Mf is estimated from the integrated value of the current pulse signal of the rotation angle signal SIGf, and the excitation timing of the stator of the front motor Mf is determined based on the rotation angle.

  When the determination of Yes is made in step S6 due to the occurrence of slip, the reset timing of the rotation angle signal SIGf is corrected based on the first reference signal from the front resolver 11f after recovering from the slip in step S8.

That is, in this case, it is presumed that a deviation has occurred between the phase of the rotation angle signal SIGr and the phase of the rotor of the rear motor Mr due to the slip of the front wheel 2f or the rear wheel 2r. Therefore, in step S8, as indicated by a broken line in FIG. 2, the rotation angle signal SIGf is reset at the output timing of the first reference signal from the front resolver 11f. This process is the same as the reset process performed at the start of generation of the rotation angle signal SIGf described above. Since the integration of the pulse signal is started in synchronization with the first reference signal, the phase of the rotation angle signal SIGf is again detected. This corresponds to the phase of the rotor of the front motor Mf.
As a result, the phase shift between the rotation angle signal SIGf and the rotor of the front motor Mf due to slip can be compensated, and the rotation angle of the rotor of the front motor Mf is appropriately estimated based on the rotation angle signal SIGf and applied to excitation of the stator. can do.

On the other hand, if the front controller 7f makes a determination of No in step S2, the process proceeds to step S10 to determine whether or not the vehicle 1 is moving backward. If the result is Yes, the process proceeds to step S12. In step S12, similarly to step S4 described above, the rotation angle signal SIGr of the rear motor Mr is multiplied by the ratio Rr / Rf to generate the rotation angle signal SIGf, and the rotation angle signal SIGf is integrated at the output timing of the first reference signal. By resetting the value, the phase of the rotation angle signal SIGf is made to correspond to the phase of the rotor of the front motor Mf. At the same time, in step S12, the backlash correction amount α (first correction amount) is added to the rotation angle signal SIGf.
Thereafter, the process proceeds to step S6, and the same processing as described above is executed. By the process of step S12, the phase of the rotation angle signal SIGf is corrected by an amount corresponding to the backlash correction amount α while maintaining the waveform.

FIG. 4 is an explanatory diagram showing the meshing state of the gear of the reduction gear 3f that is moving forward, and FIG. 5 is an explanatory diagram showing the meshing state of the gear of the reduction gear 3f that is moving backward.
While the vehicle 1 is moving forward, the speed reducer 3f is in the gear meshing state shown in FIG. 4, and at this time, the rotation angle corresponding to the rotation period and phase of the rotor of the front motor Mf is obtained by the processing of step S4 based on the rotation angle signal SIGr. A signal SIGf can be generated. However, while the vehicle 1 is moving backward, the gear meshing state of the speed reducer 3f is reversed as shown in FIG. 5, and a phase shift occurs in the rotation angle signal SIGf with respect to the rotor phase by an amount corresponding to the backlash. The backlash correction amount α is set in advance as a value corresponding to the phase shift at this time. Therefore, the phase of the rotation angle signal SIGf after correction based on the backlash correction amount α corresponds to the phase of the rotor of the front motor Mf when the vehicle 1 is moving backward.

  On the other hand, if the front controller 7f determines No in step S10, the process proceeds to step S14. In step S14, as in steps S4 and S12 described above, the rotation angle signal SIGr is multiplied by the ratio Rr / Rf to generate the rotation angle signal SIGf, and the rotation angle signal SIGf is output at the output timing of the first reference signal. Is reset to correspond to the rotor phase of the front motor Mf. At the same time, in step S14, half α / 2 of the backlash correction amount α is added to the rotation angle signal SIGf, and then the process proceeds to step S6. By the processing in step S14, the rotation angle signal SIGf becomes an intermediate phase between when the vehicle 1 moves forward and when the vehicle 1 moves backward.

At this time, the vehicle 1 is stopped with the P range or the N range selected, and may move forward by switching to the D range or may move backward by switching to the R range. The front controller 7f needs to recognize the rotor rotation angle in order to excite the stator of the front motor Mf at the beginning of the start. The rotation angle signal SIGf is maintained at an intermediate phase so that both forward and backward movements can be handled without problems.
Note that because of the phase setting of the rotation angle signal SIGf, a slight error occurs in the estimation of the rotation angle of the rotor of the front motor Mf at the moment of start, and the excitation timing of the stator becomes temporarily inappropriate. However, immediately after the start, the excitation of the stator is optimally controlled by the process of step S4 or step S12 according to the forward or backward movement, so that the vehicle 1 can be run without any problem.

  The above is the processing executed by the front controller 7f when the failure of the front resolver 11f occurs. When the failure of the rear resolver 11r occurs, the processing is based on the ratio Rf / Rr based on the rotation angle signal SIGf of the front motor Mf. A rotation angle signal SIGr corresponding to the rotation of the rotor of the rear motor Mr is generated. Then, based on the generated rotation angle signal SIGr, the rotation angle of the rotor of the rear motor Mr is estimated and the excitation of the stator is controlled. The processing of the rear controller 7r at this time is shown in parentheses in FIG. In the figure, β is a backlash correction amount (second correction amount) set corresponding to the backlash of the gear of the reduction gear 3r.

  As described above, according to the motor control device for the electric vehicle of the present embodiment, the output function of the pulse signals of the resolvers 11f and 11r is diagnosed, and when one of the resolvers 11f and 11r is out of order, the counterpart controller Based on the rotation angle signals SIGr and SIGf generated by 7r and 7f, the rotation angle signal SIGf corresponding to the rotation period and phase of the rotors of the motors Mf and Mr on the failure side by correction based on the ratios Rr / Rf and Rf / Rr. , SIGr is generated, and based on the rotation angle signals SIGf, SIGr, the rotation angles of the rotors of the motors Mf, Mr on the failure side are estimated and applied to excitation of the stator.

  Further, when a slip occurs in the front wheel 2f or the rear wheel 2r, the slip timing is corrected by correcting the reset timing of the rotation angle signals SIGf and SIGr based on the first or second reference signal from the other resolver 11r or 11f. The phase shift generated between the rotation angle signal SIGf and the rotor of the front motor Mf or the phase shift generated between the rotation angle signal SIGr and the rotor of the rear motor Mr is compensated. Therefore, regardless of the presence or absence of slip, the rotor rotation angle of the front motor Mf or the rear motor Mr can always be accurately estimated from the rotation angle signals SIGf and SIGr, so that the excitation of the stator can be appropriately controlled. Therefore, according to this embodiment, even if a failure occurs in any of the resolvers, it is possible to continue normal vehicle 1 traveling.

  Further, since the rotation angle signals SIGf and SIGr are generated in consideration of the ratios Rr / Rf and Rf / Rr of the reduction ratios Rf and Rr of both the motors Mf and Mr, the front motor Mf and the rear motor Mr as in the present embodiment The present invention can also be applied to the vehicle 1 in which the reduction ratios Rf and Rr are different, and the above-described effects can be obtained.

  Further, during the backward movement of the vehicle 1, the phase shift of the rotation angle signals SIGf and SIGr caused by the backlash of the speed reducers 3f and 3r is corrected by the backlash correction amounts α and β. For this reason, even when the vehicle 1 is moving backward, the rotation angles of the rotors of the motors Mf and Mr can be accurately estimated, and the excitation of the stator can be appropriately controlled. Contrary to the embodiment, the rotation angle signals SIGf and SIGr are generated according to the gear meshing state of the speed reducers 3f and 3r when the vehicle 1 is moving backward, and the backlash correction amount α, Correction based on β may be performed. Further, the correction processing based on the backlash correction amounts α and β may be omitted.

  On the other hand, in the present embodiment, the reset timing of the rotation angle signals SIGf, SIGr is set based on the first or second reference signal from the other resolver only when the slip determination of the front wheel 2f or the rear wheel 2r is made. It is corrected. Therefore, in a situation where no slip occurs, the reset timing correction process is not performed, and the calculation load on the controllers 7f and 7r can be reduced.

However, in the present invention, slip determination is not essential and may be omitted. For example, when the front controller 7f determines the failure of the front resolver 11f, the second pulse signal input from the rear resolver 11r is corrected based on the ratio Rr / Rf of the reduction ratios Rf and Rr, and then the second The rotation angle signal SIGf may be generated by sequentially resetting the integrated value of the pulse signals at the output timing of the first reference signal from the front resolver 11f (reset for each first reference signal).
The same applies when a failure occurs in the rear resolver 11r, and the period of the first pulse signal input from the front resolver 11f is corrected based on the ratio Rf / Rr, and then the integrated value of the first pulse signal is calculated. The rotation angle signal SIGr may be generated by always resetting at the output timing of the second reference signal from 11r.

  That is, in the present invention, the reference signal from the other-side resolver 11f, 11r is not necessarily required, and based on the reference signal from the other-side resolver 11f, 11r and the pulse signal from the other-side resolver 11f, 11r, Rotation angle signals SIGf and SIGr corresponding to the motors Mf and Mr. Even in this case, the phases of the rotation angle signals SIGf and SIGr always coincide with the phases of the rotors of the motors Mf and Mr, regardless of the presence or absence of slip. Therefore, similarly to the above embodiment, the rotor rotation angles of the motors Mf, Mr can be accurately estimated from the rotation angle signals SIGf, SIGr.

This is the end of the description of the embodiment, but the aspect of the present invention is not limited to this embodiment. For example, in the above-described embodiment, the electric vehicle 1 is implemented by driving the front wheels 2f and the rear wheels 2r individually by the front motor Mf and the rear motor Mr, but the present invention is not limited to this. The vehicle may be applied to a hybrid vehicle as long as the front wheel and the rear wheel are individually driven by a motor. In this case, the same effect as that of the above embodiment can be obtained.
In the above-described embodiment, the failure of both the front side and rear side resolvers 11f and 11r is dealt with. However, the present invention is not limited to this, and the failure of only one of the resolvers may be dealt with.
In the above embodiment, the front and rear motors are individually controlled by the front controller 7f and the rear controller 7r. However, both motors may be controlled by a single controller.

Mf Front motor (first motor)
Mr rear motor (second motor)
2f Front wheel 2r Rear wheel 3f, 3r Reducer 7f Front controller
(First rotation angle determination means, slip determination means, failure diagnosis means)
7r Rear controller
(Second rotation angle determination means, slip determination means, failure diagnosis means)
11f resolver (first signal output means)
11r resolver (second signal output means)

Claims (6)

A first motor that drives the front wheels of the vehicle;
A second motor for driving the rear wheels of the vehicle;
A first rotation signal provided in the first motor and outputting a first rotation change signal that changes with rotation of the first motor and a first reference signal that indicates a specific reference angle of the first motor. Signal output means;
A second rotation signal that is provided in the second motor and that outputs a second rotation change signal that changes with the rotation of the second motor and a second reference signal that indicates a specific reference angle of the second motor; Signal output means;
Failure diagnosis means for diagnosing at least one of an output function of the first rotation change signal by the first signal output means and an output function of the second rotation change signal by the second signal output means;
First rotation angle determination means for determining the rotation angle of the first motor based on the first rotation change signal and the first reference signal;
Second rotation angle determining means for determining the rotation angle of the second motor based on the second rotation change signal and the second reference signal,
The first rotation angle discriminating means is based on the second rotation change signal and the first reference signal when the fault diagnosis means makes a fault judgment to the first signal output means. Estimating the rotation angle of the first motor;
The second rotation angle discriminating means is based on the first rotation change signal and the second reference signal when the fault diagnosis means makes a fault judgment to the second signal output means. A motor control device for an electric vehicle, characterized by estimating a rotation angle of a second motor.   2. The motor control device for an electric vehicle according to claim 1, wherein the failure diagnosis means makes a diagnosis by comparing the first rotation change signal and the second rotation change signal. Reducers with different reduction ratios are attached to the first motor and the second motor,
The first rotation angle determination means outputs the second rotation change signal to the reduction ratio of the first motor and the second motor when the failure diagnosis means determines the failure of the first signal output means. Correcting based on the ratio with the reduction ratio, estimating the rotation angle of the first motor based on the corrected second rotation change signal and the first reference signal,
The second rotation angle discriminating means outputs the first rotation change signal to the reduction ratio of the first motor and the second motor when the failure diagnosis means judges the failure of the second signal output means. 3. The correction according to claim 1, wherein the correction is made based on a ratio with a reduction ratio, and the rotation angle of the second motor is estimated based on the corrected first rotation change signal and the second reference signal. The motor control apparatus of the electric vehicle as described. The first rotation angle discrimination means is either forward or backward of the vehicle driven by the first motor and the second motor when the failure diagnosis means judges the failure of the first signal output means. The phase of the first reference signal is corrected based on the first correction amount set in advance corresponding to the backlash of the reduction gear of the first motor, and the second rotation change signal and the corrected Estimating the rotation angle of the first motor based on the first reference signal of
The second rotation angle discriminating means is either forward or reverse of the vehicle driven by the first motor and the second motor when the failure diagnostic means judges the failure of the second signal output means. The phase of the second reference signal is corrected based on a second correction amount set in advance corresponding to the backlash of the reduction gear of the second motor, and the first rotation change signal and the corrected The motor control device for an electric vehicle according to any one of claims 1 to 3, wherein the rotation angle of the second motor is estimated based on the second reference signal. The first rotation angle discriminating unit integrates the second rotation change signal and calculates an integrated value of the second rotation change signal when the failure diagnosis unit determines a failure of the first signal output unit. Reset at the output timing of the first reference signal, estimate the rotation angle of the first motor based on the integrated value at the time of the reset,
The second rotation angle discriminating unit integrates the first rotation change signal and calculates an integrated value of the first rotation change signal when the failure diagnosis unit determines the failure of the second signal output unit. 5. The electric vehicle according to claim 1, wherein the electric vehicle is reset at an output timing of the second reference signal, and a rotation angle of the second motor is estimated based on an integrated value at the time of the reset. Motor control device. A slip determination means for determining a slip generated on a front wheel or a rear wheel of the vehicle,
The first rotation angle discriminating means, when the slip judging means makes a slip judgment when the failure diagnosing means judges the failure of the first signal output means, the first reference after recovery from the slip. Correcting the reset timing of the integrated value of the second rotation change signal based on the signal,
The second rotation angle discriminating means, when the slip judgment is made by the slip judgment means at the time of failure judgment of the second signal output means by the fault diagnosis means, the second reference after recovery from the slip. 6. The motor control apparatus for an electric vehicle according to claim 5, wherein the reset timing of the integrated value of the first rotation change signal is corrected based on the signal.

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