JP2015006013A - Drive control device of electric automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive control device of an electric automobile, which can prevent deterioration of a drive feeling caused by torque fluctuations by eliminating non-operation in which front and rear distribution torques become zero.SOLUTION: A drive control device of an electric automobile comprises: a battery 13; front and rear motor generators 11, 12 connected to drive wheels 21, 23; driving condition detection means S detecting a driving condition of a vehicle 10; necessary output torque calculation means 552 calculating a necessary output torque T according to the driving condition; distribution torque value calculation means 553 calculating the necessary torque as distribution torques by using a distribution ratio α; and output distribution control means 554 controlling electric power supply from the battery to front and rear electric rotary machines. The front and rear distribution torques are set at values within a range of upper limit torques TMAXF, TMAXR which are the maxima of acceleration torques according to the driving condition of the vehicle, to lower limit torques TFMIN, TRMIN which are the maxima of deceleration torques.

Description

  The present invention relates to an electric vehicle drive control device that drives an electric rotating machine connected to drive wheels of an electric vehicle with an output corresponding to engine operation information.

As an electric vehicle, front and rear electric rotating machines (motors) that are power sources are connected to the front and rear shafts of front and rear driving wheels, and electric power of a battery that is an in-vehicle power source is supplied to each of these electric rotating machines via a power supply circuit. Things that run by that are known. Here, the power supply circuit is provided with a power controller, which adjusts the power supply during running to adjust the running torque, and further reduces the electric energy from the drive wheels to the front and rear electric rotating machines during deceleration running. The regenerative state is adjusted.
For example, the power controller controls the output torque of the front and rear electric rotating machines by controlling the output power from the battery according to the operation amount of the accelerator pedal in the driver's seat. Furthermore, the above-mentioned regenerative state is controlled according to the operation of the brake pedal in the driver's seat. In the regenerative state, the front / rear electric rotating machine operates as a generator, and converts the rotational energy of the drive wheels into electric energy. At this time, a braking force is applied to the driving wheel, and the converted electric energy is charged in the battery.

By the way, the electric vehicle calculates a required torque (required torque) according to the driving information and generates the required torque by at least one of the electric rotating machines of the front and rear drive wheels. In this case, it is preferable to use an electric rotating machine with a low rated output when driving in an urban area where the motor load is small, and it is preferable to use an electric rotating machine with a high rated output when driving at a maximum speed and acceleration performance.
Therefore, rather than responding to an output request with an electric rotary machine with a large rated output of only one of the front and rear, one of the front and rear of the plurality of electric rotary machines is driven, or both are driven simultaneously. As a result, it is possible to continue the motor efficient operation to save energy according to the increase or decrease of the motor load during traveling, and to extend the traveling distance per charge.

Such a prior art is disclosed in Patent Document 1.
Further, the electric vehicle of Patent Document 2 employs a motor driven at a predetermined power ratio as each front wheel and rear wheel electric rotating machine, and the front wheel and rear wheel electric rotating machines are used according to the running state. It is driven selectively.
Further, in the electric vehicle of Patent Document 3, the maximum torque and the minimum torque are given in advance in consideration of the failure of the electric rotating machine and the output limitation, and the low determination value and the high determination value are set based on this. In addition, when the required torque is equal to or less than a predetermined low judgment value, it travels only with an electric rotating machine with a low rated output, and when it exceeds a predetermined low judgment value and travels with only a high rated output electric rotating machine, When a predetermined high judgment value is exceeded, the vehicle runs on both low and high rated output electric rotating machines. Further, during braking, both the low and high rated output electric rotating machines are selectively regeneratively braked according to the degree of braking to improve the power generation efficiency during regenerative braking and to improve the amount of charge.

JP-A-7-67216 JP 2009-95230 A JP-A-5-76106

  By the way, as in Patent Document 3, as the required torque increases, a low rated output electric rotating machine, a high rated output electric rotating machine, and a low and high rated output electric rotating machine are used in this order, The battery consumption at the time of low rated output can be suppressed, and high speed and high output running with high rated output can be facilitated. However, there is an operating range in which only low-rated output and high-rated output electric rotating machine is driven. In such operating range, one electric rotating machine is not used, and the operating state of non-operating and operating electric rotating machine Due to torque fluctuation at the time of switching, the driving feeling at the time of switching decreases.

  Furthermore, at the time of high output with both low and high rated outputs, that is, when both the front and rear electric rotating machines are used, the distribution torque of one of the front and rear electric rotating machines is low and high (value limit value). If the calculation exceeds the limit value, the torque exceeding the output limit value is not output as it is, and the output torque decreases with respect to the required torque, resulting in an acceleration (deceleration) failure.

  Therefore, according to the present invention, when the calculated required torque is distributed to the respective distributed torques of the front and rear electric rotating machines, the non-operating state in which one of the front and rear distributed torques becomes zero is eliminated. It is an object of the present invention to provide a drive control device for an electric vehicle that can prevent a decrease in feeling and that can secure necessary torque even when the distribution torque on one of the front and rear sides is low and does not exceed a high judgment value. .

  In order to achieve the above object, an invention according to claim 1 includes an in-vehicle power source, a front electric rotating machine connected to the front driving wheel, a rear electric rotating machine connected to the rear driving wheel, and an accelerator opening degree of the vehicle. Driving condition detecting means for detecting driving conditions including vehicle speed, required output torque calculating means for calculating required output torque according to the driving conditions, and a distribution ratio based on the driving conditions, to calculate the required output torque. Distribution torque value calculation means for calculating acceleration or deceleration distribution torque for distribution to the front and rear electric rotating machines, and control of power supply from the in-vehicle power source to the front and rear electric rotating machines according to the front and rear distribution torques Output distribution control means, and the distribution torque before and after is set as a value within a range of an upper limit torque that is the maximum acceleration torque and a lower limit torque that is the maximum deceleration torque according to the driving conditions of the vehicle Characterized in that it is.

  According to a second aspect of the present invention, in the drive control apparatus for an electric vehicle according to the first aspect, the distribution torque value calculation means is configured when at least one of the distribution torques of the front and rear axes exceeds the upper and lower limit torque thresholds. Is characterized in that the one distributed torque is the upper and lower limit torques.

  According to a third aspect of the present invention, in the drive control apparatus for an electric vehicle according to the second aspect, the one of the distributed torques is corrected to the upper and lower limit torques, and the differential correction torque that could not be output by the rotary electric motor. Further, the distribution torque of the other rotary motor is corrected to increase or decrease.

  According to a fourth aspect of the present invention, in the drive control apparatus for an electric vehicle according to the third aspect, a corrected distribution torque obtained by increasing or decreasing the other distribution torque by an amount corresponding to the difference correction torque is the upper side of the other electric rotating machine. When the threshold value of the lower limit torque is exceeded, the other corrected distribution torque is set as the upper and lower limit torques.

  According to a fifth aspect of the present invention, in the drive control device for an electric vehicle according to the fourth aspect of the present invention, the torque that exceeds the threshold value of the lower limit torque of the other electric rotating machine and cannot be output by the electric rotating machine during deceleration. It is added to the output of the brake.

  According to the first aspect of the present invention, the required output torque is calculated as an acceleration or deceleration distribution torque for distribution to the front and rear electric rotating machines using a distribution ratio based on the operating conditions, and the distribution torque is calculated as an upper limit torque and a lower limit. Since it is set as a value within the torque range, the non-operating state where each of the distributed torques before and after is zero is eliminated, so that the torque fluctuation when the distributed torque is switched from non-operating to operating at the time of torque fluctuation There will be no driving feeling.

  According to the invention of claim 2, in addition to the effect that there is no torque fluctuation when the distribution torque of claim 1 is switched from non-operation to operation, the distribution torque exceeding one of the upper and lower limit torque threshold values is Since the upper and lower limit torques are corrected, each distribution torque is not given an excessively small value or an excessively large value, so that it is possible to prevent excessive acceleration and deceleration on only one of the front and rear axes. In this respect, the driving feeling is good.

  According to the invention of claim 3, when one of the front and rear distributed torque is a threshold value and exceeds the lower limit torque, it is further corrected to the lower limit torque, thereby preventing excessive acceleration and deceleration. In addition, since the difference distribution torque is used to correct the other distributed torque and cancel the increase / decrease, the initial required output torque can be ensured, and the uncomfortable feeling during acceleration and deceleration operations can be prevented.

According to the invention of claim 4, since the corrected distributed torque obtained by increasing or decreasing the other distributed torque by the amount corresponding to the differential corrected torque is corrected to the upper and lower limit torques, excessive acceleration and deceleration can be prevented more accurately and Feeling is good.
According to the invention of claim 5, an accurate braking characteristic can be obtained by adding torque that could not be output by the electric rotating machine to the output of the brake.

1 is an overall view of a drive control device for an electric vehicle as one embodiment of the present invention. FIG. 2 is a torque characteristic diagram of a motor generator used in the drive control apparatus for an electric vehicle in FIG. 1, where (a) shows a front torque map characteristic, and (b) shows a rear torque map characteristic. FIG. 2 is an explanatory diagram of correction of front / rear distribution torque performed by the electric vehicle drive control device of FIG. 1. It is a flowchart of the distribution control processing of the front and rear distribution torque performed by the drive control apparatus of the electric vehicle of FIG. 2 is a calculation map of output torque corresponding to an accelerator opening used in the drive control device for the electric vehicle of FIG. 1. FIG. 4 is a correction explanatory view of front / rear distribution torque performed by the drive control apparatus for an electric vehicle according to the second embodiment, where (a) shows a case where the front distribution torque is corrected, and (b) shows a case where the rear distribution torque is corrected. It is a flowchart of the distribution control process of the front and rear distribution torque performed with the drive control apparatus of the electric vehicle of 2nd Embodiment. It is calculation characteristic explanatory drawing explaining the state calculated and corrected by a different characteristic according to the magnitude of each value of the front-rear distribution torque performed with the drive control apparatus of the electric vehicle of 2nd Embodiment.

Hereinafter, the drive control apparatus of the electric vehicle which is 1st Embodiment of this invention is demonstrated.
FIG. 1 shows an overall schematic configuration of a hybrid vehicle (hereinafter simply referred to as a vehicle) 10 as an electric vehicle equipped with a drive control device for an electric vehicle to which the present invention is applied.
A vehicle 10 shown in FIG. 1 includes a front and rear motor generators (MG1, MG2) 11, 12 that are electric rotating machines, and a large-capacity driving battery 13 (a power source for the motor generators 11, 12). Hereinafter, it is simply referred to as a battery 13), a traveling engine 14, and front and rear rotation transmission mechanisms 15 and 20 that connect the front and rear drive sources and the front and rear drive wheels 21.

The battery 13 is configured to obtain a high voltage of 100 volts or more by connecting a plurality of cells in series. The battery 13 can be charged with electric power supplied from a commercial power supply 17 via a charging cable (not shown) and an in-vehicle charger 16.
The front-side motor generator 11 rotates the front wheels 21 via the front rotation transmission mechanism 15. The motor generator 12 on the rear side rotates the rear wheel 23 via the rear rotation transmission mechanism 15.
The engine 14 is controlled by the engine ECU 30. The engine 14 is operated by the fuel supplied from the fuel tank 80, rotates the front wheels 21 via the front rotation transmission mechanism 15, and drives the generator 32. The output of the generator 32 is also supplied to a 12V vehicle-mounted battery 34 via a power conversion circuit (inverter) 31. The power conversion circuit 31 is also connected to the air conditioning device 35 and is also used as a power source for the air conditioning device 35. Exhaust gas from the engine 14 is discharged into the atmosphere through an exhaust treatment device 50 and a muffler 51.

The vehicle 10 includes a hybrid ECU 55, front and rear motor ECUs 56 and 57, and a battery ECU 58 as control means. The calculation results of the front and rear motor ECUs 56 and 57 and the calculation result of the battery ECU 58 are also input to the hybrid ECU 55.
The vehicle 10 is provided with driving condition detection means S, which detects the driving condition of the vehicle by using the electric power that has become a low voltage from the battery 13 via a transformer (not shown) as a power source. A position sensor 61, a vehicle speed sensor 62, and a brake sensor 63 are provided.

The accelerator position sensor 61 detects an accelerator opening A as an operation amount of an accelerator operating unit such as an accelerator pedal in an accelerator device (not shown), and an electric signal corresponding to the detected amount is sent to the hybrid ECU 55 as an accelerator opening A. Output. The vehicle speed sensor 62 detects the vehicle speed V and outputs an electric signal corresponding to the detected amount as the vehicle speed V. The brake sensor 63 detects a brake degree B as an operation amount of a brake operation unit such as a brake pedal in a brake device (not shown), and outputs an electric signal corresponding to the detected amount as the brake degree B.
As shown in FIG. 1, a battery detection unit 70 is provided to detect the state of the battery 13. The battery ECU 58 includes an SOC calculator 71 that detects the charging rate SOC of the battery 13 based on the output of the battery detection unit 70, a battery internal resistance calculator 72 that detects the internal resistance of the battery 13, and a deterioration state of the battery 13. A battery deterioration state calculator 73 to be detected is included.

The rotational speeds of the front and rear motor generators (MG1, MG2) 11, 12 which are electric rotating machines are detected by the rotational speed sensors 80f, 80r and input to the motor ECUs 56, 57. Further, the temperatures of the front and rear motor generators 11 and 12 are detected by the temperature sensors 81f and 81r and input to the motor ECUs 56 and 57, respectively. The motor ECUs 56 and 57 monitor the states of the front and rear motor generators 11 and 12 based on these data.
Incidentally, the first and second power conversion circuits 31 and 33 convert the DC voltage from the battery 13 into an AC voltage and output the AC voltage to the first and second motor generators 11 and 12. Furthermore, it has a function as an inverter that converts the AC voltage generated by the regenerative operation of the first and second motor generators 11 and 12 into a DC voltage and charges the battery 13.

Moreover, the first and second power converters 31 and 33 also have a function as a converter that boosts the DC voltage received from the battery 13 and outputs the boosted DC voltage to the first and second motor generators 11 and 12. The front and rear motor ECUs 56 and 57 of the first and second power conversion means 31 and 33 are inputted to the front and rear shaft output torques (torque command values) TF and TR, and the current values of the first and second motor generators 11 and 12, respectively. , And each phase coil voltage (not shown) is calculated, a PWM (Pulse Width Modulation) signal is generated based on the calculation result, and voltage control of the first and second motor generators 11 and 12 is performed.
Further, the hybrid ECU 55 uses the first and second power conversion means 31 and 33 based on the input front and rear shaft output torques (torque command values) TF and TR, the motor speed, the vehicle speed V, the accelerator opening A, and the brake degree B. The torque distribution control function for optimizing the input voltage of is provided.

  Here, power is supplied from the battery 13 to the front and rear motor generators 11 and 12 through individual power conversion circuits 31 and 33. Further, the output characteristics of the front and rear motor generators 11 and 12 are different. Specifically, the front motor generator (MG1) 11 has a maximum torque TMAXF that is a maximum output with respect to the vehicle speed V, for example, a vehicle speed V = 0, as indicated by a torque characteristic L1 of the front torque map m1 shown in FIG. This is a large output motor having 8 kgfm. The rear motor generator (MG2) 12 has a small output such that the maximum torque TMAXR with respect to the vehicle speed V has, for example, 2 kgfm at the vehicle speed V = 0, as indicated by the torque characteristic L2 of the rear torque map m2 shown in FIG. It is a motor. That is, the output characteristics of the front and rear motor generators 11 and 12 have a relationship of TMAXF> TMAXR. Correspondingly, the characteristics of the recovery torque (−) are similarly in the relationship of −TMINF> −TMINR. 2 (a) and 2 (b) indicates the rated output points of the front and rear motor generators 11 and 12, and the curves L1-1 to L1n and L2-1 to L2-n indicate the efficiency characteristics. Show.

The hybrid ECU 55 is configured as a microcomputer that uses power from the battery 13 via a transformer (not shown) as a power source, and operates according to a program preset as a system base in the memory of the microcomputer. Specifically, a storage unit 551, a required output torque calculation unit 552, a distribution torque value calculation unit 553, and an output distribution control unit 554 are provided.
Here, the storage means 551 stores the vehicle speed V and the maximum torque (upper limit torque) TMAXF, TMAXR (A> 0 during acceleration) for each of the front and rear motor generators 11 and 12 and the lower limit torque TFMIN, TRMAX obtained as experimental results. Torque characteristic data (see FIGS. 2A and 2B) that defines the relationship with (B> 0 during deceleration) is stored.

  Next, the required output torque calculating means 552 calculates the required output torque T (= TFreq + TRreq) according to the operating conditions.

Specifically, a predetermined output torque T necessary for maintaining the vehicle speed V corresponding to the accelerator opening A is preset. A predetermined torque calculation formula (1): T = A (B) {TMAXF (−TMINF ) + TMAXR (TMINR)}, taking into account the accelerator opening A, the vehicle speed V, and the brake degree B.
Next, the distribution torque value calculation means 553 reads a predetermined distribution ratio based on a preset operating condition, and performs an operation for distributing the required output torque T to the front and rear distribution torques TFreq and TRreq at the distribution ratio α, that is, necessary. The output torque T (= α × TFreq + (α−1) × TRreq) is calculated and set (see Δ marks in FIGS. 3A and 3B).

Next, the distribution torque value calculation means 553 sets the front / rear distribution torques TFreq and TRreq (Δ mark) within the range E of the upper limit torque that maximizes the acceleration torque and the lower limit torque that maximizes the deceleration torque according to the driving conditions of the vehicle ( The values are corrected to the values shown in FIGS. 3 (a) and 3 (b). In FIGS. 3 (a) and 3 (b), when the correction is unnecessary, the triangle mark is shown as the circle mark.
With this process, at least one of the front and rear distribution torques TFreq and TRreq during traveling does not become zero, that is, the front and rear motor generators 11 and 12 do not temporarily stop. For this reason, it is possible to eliminate a situation in which a relatively large torque fluctuation occurs by restarting from the stop, and it is possible to prevent a torque shock from deteriorating the driving feeling.

  Further, here, as shown in FIGS. 3A and 3B, at least one of the front and rear distribution torques TFreq and TRreq is the upper limit, the lower limit torque thresholds TMAXF and R (during acceleration), and the lower limit torques TFMINF and R (deceleration). (Fig. 3 (a) corresponds to the front wheel side and (b) corresponds to the rear wheel side), one of the distribution torques exceeding the threshold value is corrected to the exceeding threshold value (correction arrow; when dT increases) In the case of the difference correction torque of -dT, the difference correction torque when -dT is reduced), the value after correction (修正) is set considering the front and rear distribution torques TFreq and TRreq at that time. By this processing, it is possible to more reliably eliminate a situation in which a torque shock due to a relatively large torque fluctuation occurs when one of the front and rear motor generators 11 and 12 is temporarily stopped and restarted. Can be maintained well.

Next, the output distribution control unit 554 generates a PWM signal for supplying power in accordance with the front / rear distribution torques TFreq and TRreq input from the distribution torque value calculation unit 553, and the first and the second through the motor ECUs 56 and 57. The amount of power supplied from the battery 13 to the front and rear motor generators 11 and 12 is controlled by voltage control using the second power conversion means 31 and 33.
Next, the front / rear distribution torque distribution control process according to the first embodiment will be described with reference to the flowchart of FIG.
Here, the main switch (not shown) is turned on, the accelerator operation unit is operated, and the vehicle travels by the action on the power running side of the front and rear motor generators 11 and 12 under the control of the main routine (not shown).

It is assumed that a steady control process is performed in a main routine (not shown) and reaches step s1 of the flowchart shown in FIG. 4 at a predetermined time.
In step s1, the vehicle speed V detected by the vehicle speed sensor 62 detected by the accelerator sensor 61, the accelerator opening A, and the brake degree B detected by the brake sensor 63 are read, and the process proceeds to step s2, where the vehicle speed V and the accelerator opening A are determined. Thus, the required output torque T is calculated.
Specifically, a calculation formula (1) based on a predetermined MAP (for example, a map m3 in FIG. 5) in which a characteristic of the output torque T corresponding to the accelerator opening A obtained by an experiment is preset: T = MAP (V, A) is calculated in consideration of the accelerator opening A and the vehicle speed V.

Next, in step s3, TMAXF, TMAXR, TMINF, and TMINR are calculated.
Specifically, the maximum torques TMAXF and TMAXR and the minimum torques TMINF and TMINR of the front and rear motor generators 11 and 12 are extracted from torque characteristic data D (not shown) with the current vehicle speed V as a reference. Further, the TMAXF, TMAXR, TMINF, and TMINR values obtained from the torque characteristic data of the rotary motor based on the heat generation, failure, SOC value, and the like of the front and rear motor generators 11 and 12, the front and rear power conversion circuits 31 and 33, and the high voltage battery 13. Alternatively, it may be reduced and corrected.
Next, in step s4, it is determined whether or not T ≧ 0. If Yes, the vehicle is accelerating, and if No, the vehicle is decelerating.

When proceeding to step s5, here, in particular, the front / rear distribution torques TFreq and TRreq are values within the upper limit torque range E (see FIG. 3 (a)) between the upper limit torque at which the acceleration torque becomes maximum and the maximum deceleration torque. Then, the current front and rear distribution torques TFreq and TRreq are set as they are.
Next, the process proceeds to step s7, and it is assumed that at least one of the calculated front / rear distribution torques TFreq and TRreq is a value that deviates from the upper and lower limit torque range E.
Here, in the case of acceleration, in FIG. 3 (a), the front side exceeds the upper limit torque threshold value TMAXF, and in FIG. 3 (b), the rear side exceeds the upper limit torque threshold value TMAXR. Is regarded as one of the distribution torques, and the corrected value is calculated as the front and rear distribution torques TFreq and TRreq at that time (in FIGS. 3 (a) and 3 (b), as indicated by symbol ◎). To correct).

As described above, when the upper and lower limit torque threshold values TMAXF and TMAXR (acceleration) are exceeded, the process proceeds from step s7 to s8. Here, output command signals of the calculated front / rear distribution torques TFreq, TRreq are output to the front / rear power conversion circuits 31, 33 via the front / rear motor ECUs 56, 57, whereby the front / rear motor generators (MG1, MG2) 11, 12 outputs the front and rear distribution torques TFreq and TRreq, and returns to the main routine.
On the other hand, at the time of braking, the process proceeds from step s4 to step s6. Here, the front and rear regenerative torques -TFreq, -TRreq (power generation torque by deceleration) are output as they are within the range of the upper and lower limit torques.
Next, the process proceeds to step s9, and it is assumed that at least one of the calculated front / rear distribution torques TFreq and TRreq is a value that deviates from the range E of the upper and lower limit torques.

Here, since it is during deceleration, FIG. 3A corresponds to the case where the threshold value TMINF for the front lower limit torque is exceeded, and in FIG. 3B, the rear side deviates from the threshold value TMINR for the lower limit torque. Here, the lower one is corrected to the minimum torques TMINF and TMINR. The corrected value is output as the front-rear distribution torque at that time -TFreq, -TRreq (regenerative torque).
Here, if it progresses to step s10 from step s9, it will be judged whether the brake degree B is increasing by further depression operation of a brake pedal, and if not increasing, it will progress to step s12, and if it has increased, it will progress to step s11.

  In step s11, in order to secure more braking characteristics, both TFreq and TRreq are set to the minimum torque −TMINF and −TMINR, and the process proceeds to step s12.

In step s12, front and rear regenerative torque -TFreq, -TRreq output command signals are output to front and rear power conversion circuits 31 and 33 via front and rear motor ECUs 56 and 57, whereby front and rear motor generators (MG1, MG2) 11, 12 are output. Functions as a generator, generates power corresponding to the front / rear distribution torque -TFreq, -TRreq (regenerative torque), and returns to the main routine.
At the same time, when the driver further depresses the brake pedal, the braking function is further enhanced and the braking force applied to the vehicle is reliably increased.

  In the braking operation of step s12, in addition to the braking process here, the lower limit torque threshold value (minimum torque -TMINF, -TMINR) is exceeded and the regenerative torque is output by the front and rear motor generators (MG1, MG2) 11, 12. In order to compensate for the torque (negative value) that could not be performed, for example, an auxiliary braking actuator (not shown) provided in the brake device of the vehicle may be turned on to add a braking output. In this case, more accurate braking characteristics can be obtained by adding braking torque, which could not be output by the front and rear motor generators (MG1, MG2) 11, 12, to the output of the brake.

Thus, the required output torques TF and TR are calculated as the front and rear distribution torques ± TFreq and ± TRreq using the distribution ratio α based on the operating conditions, and the front and rear distribution torques ± TFreq and ± TRreq are the upper limit torque TMAXF which is a threshold value. , TMAXR and lower limit torques TMINF and TMINR are set as values within a range E, so that the non-actuated state where the front and rear distributed torques ± TFreq and ± TRreq are zero can be eliminated. For this reason, there is little discomfort due to torque fluctuation when the distributed torque is switched from non-operation to operation during torque fluctuation, and driving feeling is improved.
Moreover, since one of the distribution torques exceeding the threshold value is corrected to that threshold value, it is possible to reliably prevent excessive acceleration / deceleration on only one of the front and rear axes, and there is less sense of incongruity. Become.

Next, an explanation will be given of a drive control apparatus for an electric vehicle as a second embodiment.
As in the first embodiment, the drive control apparatus for an electric vehicle according to the second embodiment includes a storage unit 551 that stores the characteristics of the front and rear motor generators 11 and 12, and a required output torque calculation unit that calculates the required output torque T. 552, the distribution torque value calculation means 553 for calculating the front and rear distribution torques TFreq and TRreq, and the first and second power conversion means 31 and 33 are voltage-controlled so as to supply power according to the front and rear distribution torques TFreq and TRreq. Although the output distribution control means 554 is provided, the functional configuration of the distribution torque value calculation means 553a here is different from that of the first embodiment.
For this reason, avoiding repeated explanation here, the functional configuration of the distributed torque value calculation means 553a will be mainly described.

The distribution torque value calculation means 553a used by the drive control apparatus for an electric vehicle according to the second embodiment uses the front and rear distribution torques TFreq and TRreq (Δ mark) as the upper limit torque, similarly to the distribution torque value calculation means 553 of the first embodiment. And a value within the lower limit torque range E (see FIG. 6). By this process, the motor generators 11 and 12 on one of the front and rear sides do not stop, so that a situation in which a relatively large torque fluctuation occurs can be eliminated and the driving feeling can be maintained well.
Further, as shown in FIGS. 6A and 6B, at least one of the front and rear distribution torques TFreq and TRreq is higher, and lower limit torque thresholds TMAXF and R (acceleration) and lower limit torques TFMINF and R (deceleration). If it exceeds (the front side corresponds to FIG. 6 (a), the rear side corresponds to (b)), one of the distribution torques exceeding the threshold is corrected to the threshold exceeding (the correction arrow; when dT is increased, -dT becomes At the time of reduction correction), the value after correction (marked by ◎) is set considering the front and rear distribution torque (correction distribution torque) TFreq and TRreq at that time.

In addition to this, when the front / rear distribution torque (corrected distribution torque) TFreq, TRreq is corrected as a value within the range of the upper limit and the lower limit torque, the following processing is further added.
Here, as shown in FIGS. 6A and 6B, when the front shaft and rear shaft distribution torques TFreq and TRreq are corrected within the range E between the upper limit torque and the lower limit torque, the difference correction torque used is ± dT. On the other hand, the other distributed torque is increased or decreased by an amount corresponding to the difference correction torque ± dT so as to compensate the output of the necessary drive torque T.
That is, when the front shaft distribution torque TFreq is corrected within the range E as shown in FIG. 6 (a), the other rear shaft distribution torque TRreq 'is increased / decreased by an amount corresponding to the difference correction torque ± dT. Thus, the required output torque T calculated by the required output torque calculating means 552 is compensated.

Similarly, when the rear-shaft distribution torque TRreq is corrected as shown in FIG. 6B, the front-shaft distribution torque TFreq ′, which is the other, is corrected to increase / decrease by the amount corresponding to the difference correction torque ± dT. The output torque calculating means 552 compensates the required output torque T calculated.
Thereafter, the first and second power conversion means 31 and 33 are voltage-controlled so that the output distribution control means 554 supplies power according to the front and rear distribution torques TFreq and TRreq.
Next, the distribution control process of the front / rear distribution torque of the second embodiment will be described with reference to the flowchart of FIG. 7 and the arithmetic expression explanatory diagram of FIG.

In contrast to the flowchart of FIG. 4 used in the first embodiment, this flowchart has steps s5 ′ and s7 ′ added between steps s5 and s8, and steps s6 ′ and s6 ′ between steps s6 and s10. The only difference is that step s9 'is added.
For this reason, the description of the overlapping steps is avoided here, and steps s5 ′ to s7 ′ and steps s6 ′ to s9 ′ are mainly described.
In addition, in description here, the arithmetic expression explanatory drawing of FIG. 8 is demonstrated simultaneously. In the explanatory diagram, the front shaft output torque: TF, the rear shaft output torque: TR, the front shaft distribution torque: TF _req , the rear shaft distribution torque: TR _req , the required torque T (= TF _req + TR _req ), the front shaft The minimum torque: TF _min , front shaft maximum torque: TF _max , rear shaft minimum torque: TR _min , and rear shaft maximum torque: TR _max are used as symbols. Further, here, max (): maximum value calculation value, min (): minimum value calculation value are shown.

In step s5 of the flowchart of FIG. 6, the front / rear distribution torques TFreq and TRreq are values within a range E (see FIG. 3A) of the upper limit torque that maximizes the acceleration torque and the lower limit torque that maximizes the deceleration torque. In FIG. 8, the region e is (e1), and the current front-rear distribution torques TFreq and TRreq are set as they are.
When the process proceeds from step s5 to step s5 ′, it is determined whether or not the front / rear distribution torques TFreq and TRreq both exceed the upper limit torque that is the maximum of the acceleration torque, and if so, the process proceeds to step s7, otherwise the process proceeds to step s7 ′.
In step s7, the rear distribution torques TFreq and TRreq both exceed the threshold, that is, the front and rear exceed the upper limit torque TMAXF and TMAXR (the front upper limit torque TMAXF in FIG. 6A, the rear upper limit torque TMAXR in FIG. 6B). The arithmetic expression in the area (e7) in FIG. 8 is adopted, and the process proceeds to step s8.

On the other hand, the process proceeds to step s7 ′, and it is assumed that at least one of the calculated front and rear distribution torques TFreq and TRreq is a value that deviates from the upper limit torque range E.
Here, when the vehicle is accelerating, the front side in FIG. 6A corresponds to the case where the upper side is separated from the upper limit torque threshold value TMAXF, and the rear side is separated from the upper limit torque threshold value TMAXR in FIG. Here, the threshold value that has been exceeded is corrected as one distribution torque, and the corrected value is calculated as the front and rear distribution torques TFreq and TRreq at that time. Here, arithmetic expressions in the areas (e3) and (e6) of FIG. 8 are employed.
Moreover, in step s7 ′, as shown in FIGS. 6A and 6B, the front and rear shaft distribution torques TFreq and TRreq are corrected by the difference correction torque ± dT within the range E of the upper limit torque and the lower limit torque. Accordingly, in order to compensate for the output of the required drive torque T, the distribution torque on the other side of the front and rear axes is inversely increased or decreased by an amount corresponding to the difference correction torque ± dT.

In this case, as shown in FIG. 6A, the distribution torques TFreq ′ and TRreq ′, which are the other on the front and rear axes, are increased / decreased by an amount corresponding to the difference correction torque ± dT, and the arithmetic expressions of the regions e3 and e6 Is used. Thus, the required output torque T calculated by the required output torque calculating means 552 is compensated, and the process proceeds to step s8, and the output command signals of the calculated front and rear distribution torques TFreq and TRreq are sent to the front and rear power conversion circuits 31 and 33. Output and return to the main routine.
On the other hand, when step s6 in the flowchart of FIG. 6 is reached during deceleration, the front and rear distribution torques TFreq and TRreq are values within the range E (see FIG. 3A) of the upper limit torque and the lower limit torque of the deceleration torque. If it is determined, it is the area e of (e1) in FIG. 8, and the current front and rear distribution torques TFreq and TRreq are set as they are.

When the process proceeds from step s6 to step s6 ′, it is determined whether or not the front / rear distribution torques TFreq and TRreq both exceed the lower limit torque that is the minimum of the deceleration torque.
In step s9, when the front and rear regenerative torques -TFreq and -TRreq both fall below the lower limit torque, braking is performed in the region (e4) in FIG. 8, and both are corrected to the minimum torques -TMINF and -TMINR.
Here, when the process proceeds from step s6 ′ to s9 ′, the front and rear shaft distribution torques TFreq and TRreq are corrected within the range E of the upper limit torque and the lower limit torque, and one of the front and rear is corrected to the minimum torque −TMINF and −TMINR. Here, it is the area of (e2) and (e5) in FIG. 8, and the arithmetic expression here is adopted.

In addition, here, when one of the front and rear is corrected, the other of the front and rear is corrected to compensate for the output of the necessary driving torque T. Here, on the other hand, the distribution torque on the other side of the corrected front shaft and rear shaft is increased or decreased by the amount corresponding to the difference correction torque ± dT. In this case, as shown in FIGS. 6A and 6B, the distribution torques TFreq ′ and TRreq ′, which are the other on the front and rear axes, are increased / decreased by an amount equivalent to the difference correction torque ± dT, and then distributed back and forth. Torques TFreq and TRreq are set.
Thus, the required output torque T calculated by the required output torque calculating means 552 is compensated, and the process proceeds to step s10.
In step s10, it is determined whether the brake degree B has increased. If it has increased, step s11 is reached. Here, both TFreq and TRreq are set to the minimum torque −TMINF and −TMINR, and the process proceeds to step s12.

In step s12, front and rear regenerative torque -TFreq, -TRreq output command signals are output to front and rear power conversion circuits 31 and 33 via front and rear motor ECUs 56 and 57, whereby front and rear motor generators (MG1, MG2) 11, 12 are output. Functions as a generator, generates power corresponding to the front / rear distribution torque -TFreq, -TRreq (regenerative torque), and returns to the main routine. At the same time, since the driver further depresses the brake pedal, the braking function is enhanced and the braking force applied to the vehicle is reliably increased.
According to the second embodiment, in particular, when the front shaft and rear shaft distribution torques TFreq and TRreq are corrected within the range E of the upper limit torque and the lower limit torque, the necessary drive is performed with respect to the difference correction torque ± dT used. On the contrary, the other distributed torque is increased / decreased by an amount corresponding to the difference correction torque ± dT so as to compensate the output of the torque T. For example, as shown in FIG. 6 (a), the rear-shaft distribution torque TRreq ′, which is the other side, is increased / decreased by an amount corresponding to the difference correction torque ± dT, or before the other side, as shown in FIG. 6 (b). The shaft distribution torque TFreq ′ is corrected to increase / decrease on the contrary by an amount corresponding to the difference correction torque ± dT, whereby the required output torque T calculated by the required output torque calculating means 552 is compensated. For this reason, since the initial required output torque can be ensured, a sense of incongruity during acceleration and deceleration operations can be reliably prevented.

  In the above, a hybrid vehicle has been described as an electric vehicle. However, instead of this, the present invention can also be applied to an EV vehicle, and can be configured in substantially the same manner, and the same effects can be obtained.

10 Vehicle 11 Front motor generator (electric rotating machine)
12 Rear motor generator (electric rotating machine)
13 Battery 21, 23 Drive wheel 552 Required output torque calculation means 553 Distribution torque value calculation means 554 Output distribution control means α Distribution ratio TMAXF, TMAXR Upper limit torque TFMIN, TRMAX Lower limit torque S Operating condition detection means T Required output torque

Claims (5)

In-vehicle power supply,
A front electric rotating machine coupled to the front drive wheel;
A rear electric rotating machine coupled to the rear drive wheel;
Driving condition detection means for detecting driving conditions including the accelerator opening and vehicle speed of the vehicle;
Required output torque calculating means for calculating the required output torque according to the operating conditions;
Using a distribution ratio based on the operating condition, a distribution torque value calculation means for calculating the distribution torque of acceleration or deceleration for distributing the required output torque to the front and rear electric rotating machines;
Output distribution control means for controlling power supply from the in-vehicle power source to the front and rear electric rotating machines in accordance with the front and rear distribution torques, and
The front and rear distributed torque is set as a value within a range of an upper limit torque that maximizes acceleration torque and a lower limit torque that maximizes deceleration torque according to the driving conditions of the vehicle. .   The distribution torque value calculation means, when at least one of the distribution torques of the front and rear axes exceeds the upper and lower limit torque thresholds, sets the one distribution torque as the upper and lower limit torques. The drive control apparatus of the electric vehicle of 1.   3. The increase / decrease correction of the distribution torque of the other rotary motor is performed by a differential correction torque that could not be output by the rotary motor because the one distribution torque was corrected to the upper and lower limit torques. The drive control apparatus of the electric vehicle as described.   When the corrected distribution torque obtained by increasing / decreasing the other distributed torque by an amount corresponding to the differential correction torque exceeds the upper / lower limit torque threshold of the other electric rotating machine, the other corrected distribution torque is changed to the upper / lower limit torque. The drive control apparatus for an electric vehicle according to claim 3.   5. The drive control device for an electric vehicle according to claim 4, wherein a torque that exceeds a threshold value of the lower limit torque of the other electric rotating machine and cannot be output by the electric rotating machine is added to the brake output during deceleration. .

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