JP6004544B2 - Drive control device, hybrid vehicle including the drive control device, and drive control method - Google Patents

Description

  The present invention relates to a drive control device, a hybrid vehicle including the drive control device, and a drive control method.

  In recent years, taking into consideration environmental problems and the like, development of electric vehicles such as an electric vehicle that can run only by a motor (electric motor) and a hybrid electric vehicle that uses an engine and a motor as drive sources has been progressing. A three-phase motor is mainly used as the motor, and electric power is supplied to the motor from a battery capable of storing electric power for driving the motor via an inverter that converts direct current into alternating current and alternating current.

And when abnormality occurs in the drive system including the motor and the inverter, it is possible to suppress excessive electric power from being input to the battery, to prevent the motor from generating power by the engine driving force and preventing inadvertent charging. For this purpose, three-phase short-circuit control is known in which the inverter is in a three-phase short-circuit state (see, for example, Patent Document 1).
It is also known that load torque (also referred to as drag torque) is generated in the motor in a three-phase short circuit state of the inverter (see, for example, Patent Document 2).

JP 2011-172343 A JP 2006-296068 A

  However, in a vehicle having a drive system in which a motor is directly connected to the input side of the transmission, drag torque generated in the motor when the inverter is three-phase short-circuited has a great influence on the running performance of the vehicle, in particular, shift control. In order to eliminate the influence of drag torque during a three-phase short circuit, it is necessary to fix the transmission to a low-speed gear such as the second speed and drive the vehicle without shifting, which greatly limits the driving performance of the vehicle There is a risk of being.

  The present invention has been made to solve at least a part of such problems, and the object of the present invention is to minimize the influence on the running performance of the vehicle due to the three-phase short circuit of the inverter. A drive control device, a hybrid vehicle including the drive control device, and a drive control method are provided.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

(1) A drive control device according to this application example includes an engine that is a drive source of a vehicle, an electric motor that is connected to an output side of the engine via a clutch and that is a drive source of the vehicle and can generate power, A transmission that is directly connected to the output side of the electric motor, shifts the vehicle, a battery that can store electric power for driving the electric motor, and a direct current and an alternating current of the electric power between the battery and the electric motor. An inverter that performs conversion, a shift control unit that controls the shift of the transmission, an abnormality detection unit that detects an abnormality in a power supply circuit including the electric motor, the inverter, and the battery, and an abnormality that is detected by the abnormality detection unit A three-phase short-circuit means for bringing the inverter into a three-phase short-circuit state, a rotation speed detection means for detecting the rotation speed of the motor, and the three-phase short-circuit means. In the case where data is to the three-phase short-circuit state, when the rotation speed of the motor detected by the rotational speed detecting means is less than the predetermined set rotational speed, the shift control prohibiting means for prohibiting the transmission by the transmission And comprising.

  (2) A drive control device according to this application example includes an engine that is a drive source of a vehicle, an electric motor that is connected to an output side of the engine via a clutch, and that is a drive source of the vehicle and capable of generating power, A transmission that is directly connected to the output side of the electric motor, shifts the vehicle, a battery that can store electric power for driving the electric motor, and a direct current and an alternating current of the electric power between the battery and the electric motor. An inverter that performs conversion, a shift control unit that controls the shift of the transmission, an abnormality detection unit that detects an abnormality in a power supply circuit including the electric motor, the inverter, and the battery, and an abnormality that is detected by the abnormality detection unit When the inverter is brought into the three-phase short-circuit state by the three-phase short-circuit means for bringing the inverter into a three-phase short-circuit state, When the target rotational speed of the shift-up control in the shift control means is less than the predetermined set rotational speed, and a shift control prohibiting means for prohibiting the shift-up control by the shift control means

(3) The drive control apparatus according to the application example may include a rotation speed correction unit that increases the rotation speed of the electric motor .
(4) In the drive control device according to the application example, the set rotational speed may be set in a rotational speed region in which drag torque generated in the electric motor begins to gradually increase as the rotational speed of the electric motor gradually decreases.

(5) The hybrid vehicle according to this application example includes any one of the drive control devices described above.
(6) The drive control method according to this application example is connected to the output side of the engine, which is the drive source of the vehicle, via a clutch, and is directly connected to the input side of the transmission. An abnormality in a power supply circuit including a possible electric motor, a battery capable of storing electric power for driving the electric motor, and an inverter that converts direct current and alternating current of the electric power between the battery and the electric motor An abnormality detection step, a shift control step for performing shift control of the transmission, a three-phase short-circuit step for setting the inverter in a three-phase short-circuit state when an abnormality is detected by the abnormality detection step, and a rotation speed of the motor In the case where the inverter is brought into the three-phase short circuit state by the rotation speed detection step to detect and the three-phase short circuit step, the rotation speed detection step When the rotation speed of the issued the electric motor is less than the predetermined set rotational speed, and a shift control prohibiting step for prohibiting a change in speed by the transmission.

(7) The drive control method according to this application example is connected to the output side of the engine, which is the drive source of the vehicle, via a clutch, and is directly connected to the input side of the transmission, and is the drive source of the vehicle and also generates power. An abnormality in a power supply circuit including a possible electric motor, a battery capable of storing electric power for driving the electric motor, and an inverter that converts direct current and alternating current of the electric power between the battery and the electric motor An abnormality detection step, a shift control step for performing shift control of the transmission, a three-phase short-circuit step for setting the inverter in a three-phase short-circuit state when an abnormality is detected by the abnormality detection step, and a three-phase short-circuit step in the case where the inverter is to the three-phase short-circuit state, a predetermined set rotational speed target speed is shift-up control in the shift control step When the full, and a shift control prohibiting step for prohibiting the shift-up control by the shift control means.

(8) The drive control method according to the application example may include a rotation speed correction step for increasing the rotation speed of the electric motor .
(9) In the drive control method according to the application example, the set rotational speed may be set in a rotational speed region in which drag torque generated in the electric motor begins to gradually increase as the rotational speed of the electric motor gradually decreases.

  According to the present invention using the application example, it is possible to minimize the influence on the running performance of the vehicle due to the three-phase short circuit of the inverter.

1 is a schematic configuration diagram of a hybrid vehicle including a drive control device according to an embodiment of the present invention. It is a schematic block diagram of the inverter of FIG. It is the figure which showed the drag torque characteristic of the motor by the three-phase short circuit of the inverter of FIG. It is the figure which showed the change of the input shaft rotational speed of the transmission at the time of the speed change by the transmission of FIG. 1 in time series. It is the flowchart which showed the shift control which concerns on 1st Embodiment of this invention. (A): It is the flowchart which showed the modification of the speed-change control of FIG. 5, (b): It is the flowchart which showed an example of the rotation speed correction control of FIG. 6 (a). It is the flowchart which showed the shift control which concerns on 2nd Embodiment of this invention.

<First Embodiment>
Hereinafter, drive control according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of a hybrid vehicle provided with a drive control apparatus according to a first embodiment of the present invention, and FIG. 2 shows an outline of an inverter constituting the drive control apparatus of FIG.
As shown in FIG. 1, a hybrid vehicle 1 (hereinafter also simply referred to as a vehicle) is, for example, a parallel-type hybrid truck that uses an engine 2 and a motor 3 (electric motor) as a travel drive source.

  A clutch 4 is connected to the output shaft of the engine 2, and an input shaft of the transmission 5 is connected to the clutch 4 via a rotating shaft of the motor 3. That is, the vehicle 1 forms a drive system in which the motor 3 is connected to the output side of the engine 2 via the clutch 4 and the motor 3 is directly connected to the input side of the transmission 5 without the clutch. Therefore, the motor 3 and the transmission 5 may be mechanically connected, and the connection form is not particularly limited. Specifically, the motor 3 may be connected to the engine 2 and the transmission 5 on the same axis. Alternatively, the motor 3 may be mechanically connected to the transmission 5 by a shaft different from the shaft to which the engine 2 and the transmission 5 are connected.

A differential device 7 is connected to the output side of the transmission 5 via a propeller shaft 6, and left and right drive wheels 9 are connected to the differential device 7 via a drive shaft 8.
The transmission 5 automates the connecting / disconnecting operation of the clutch 4 and the switching operation of the shift stage based on a general manual transmission. In the present embodiment, the transmission 5 has a forward speed of 12 speeds and a reverse speed of 1 speed. The configuration of the transmission 5 is not limited to this, and can be arbitrarily changed. For example, it may be embodied as a manual transmission, or may be embodied as a so-called dual clutch type automatic transmission having two power transmission systems.

The motor 3 is a so-called three-phase motor, and is a synchronous generator motor including a rotor on which a permanent magnet is attached and a stator on which a three-phase coil is wound. The motor 3 is connected via an inverter 10 to a battery 11 that can store electric power for driving the motor 3.
The inverter 10 is a power converter, is disposed between the battery 11 and the motor 3, and performs direct current and alternating current conversion of electric power stored in the battery 11.

  Specifically, as shown in FIG. 2, the inverter 10 includes a pair of switching elements (semiconductor elements) 12 a to 12 f (for example, IGBT: insulated gate bipolar transistor) per phase connected to the three-phase coil of the motor 3. . These switching elements 12a to 12f form a three-phase bridge circuit, and the three-phase bridge circuit performs conversion between a direct current and a three-phase alternating current or voltage conversion of electric power supplied from the battery 11 to the motor 3.

  The inverter 10 can convert DC power from the battery 11 into three-phase AC power and supply it to the motor 3, and can rectify and supply the three-phase AC power from the motor 3 to the battery 11. In this way, the power supply circuit 13 is configured by the motor 3, the inverter 10, and the battery 11.

When the vehicle 1 is configured as described above, the driving force generated by the engine 2 or the motor 3 is shifted by the transmission 5 and then transmitted to the driving wheels 9.
Specifically, the driving force generated by the motor 3 is transmitted to the driving wheel 9 side regardless of whether the clutch 4 is connected or disconnected. On the other hand, the driving force generated by the engine 2 is transmitted to the driving wheel 9 only when the clutch 4 is connected. Therefore, when the clutch 4 is disengaged, the vehicle 1 travels by transmitting the positive or negative driving force generated by the motor 3 to the driving wheel 9 side. On the other hand, when the clutch 4 is connected, the driving force of the engine 2 and the motor 3 is transmitted to the driving wheel 9 side, or only the driving force of the engine 2 is transmitted to the driving wheel 9 side so that the vehicle 1 travels. .

  For example, when the vehicle 1 decelerates or travels on a downhill road, the motor 3 operates as a generator by reverse driving from the drive wheel 9 side. The negative driving force generated by the motor 3 is transmitted to the driving wheel 9 side as a braking force, and the AC power generated by the motor 3 is converted into DC power by the inverter 10 and charged to the battery 11. .

  Here, the inverter 10 is connected to the inverter ECU 14. The inverter ECU 14 calculates a target value of the current that flows from the inverter 10 to the motor 3 and sends a command to the inverter 10. Further, the inverter ECU 14 monitors the state of the inverter 10 including the current and voltage flowing through the inverter 10 and the temperature of the inverter 10 detected by a temperature sensor (not shown).

On the other hand, the battery 11 is connected to the battery ECU 16. The battery ECU 16 calculates a target value of power supplied from the battery 11 to the inverter 10 and then the motor 3, and sends a command to the battery 11.
Further, the battery ECU 16 monitors the state of the battery 11 including the temperature, voltage, current, and the like of the battery 11 detected by a temperature sensor, a voltage sensor, and a current sensor (not shown). The battery ECU 16 also monitors the operation of an emergency stop button provided on the battery 11 and a crash sensor (none of which are shown).

Further, the battery ECU 16 is connected to the inverter ECU 14. Various information acquired by the inverter ECU 14 can be shared with the inverter ECU 14, and various information acquired by the battery ECU 16 can be shared with the inverter ECU 14.
On the other hand, the transmission 5 is connected to the transmission ECU 16. The transmission ECU 16 issues a transmission control command to be described later to the transmission 5.

The inverter ECU 14, the battery ECU 16, and the transmission ECU 18 described above are connected to the vehicle ECU 20.
The vehicle ECU 20 is a control circuit including a memory, a CPU, a timer counter, and the like (not shown). The vehicle ECU 20 calculates various control amounts and controls various devices based on the control amounts. The vehicle ECU 20 is connected to various sensors and switches, and can acquire various information of the vehicle 1. For example, the vehicle ECU 20 detects a signal such as a vehicle speed detected by a vehicle speed sensor (not shown) or a motor speed detected by a rotation speed sensor 15 (rotation speed detection means) provided in the motor 3 and read into the inverter ECU. N signals are sent. Note that the information about the state of the motor 3 is not limited to being obtained indirectly from the inverter ECU or the like, but can be obtained directly from the motor 3.

  Thus, the drive control device for the vehicle 1 according to the present embodiment includes the state of the motor 3 detected by the vehicle ECU 20, the required driving state of the vehicle 1 such as the vehicle speed and torque, the state of the battery 11, and the state of the transmission 5. In response to the operation of the battery 11 and the inverter 10 via the inverter ECU 14, the battery ECU 16, and the transmission ECU 18, respectively. The drive and the shift of the transmission 5 are controlled.

  Here, the vehicle ECU 20 can detect an abnormality in the power supply circuit 13 including the motor 3, the inverter 10, and the battery 11 by being connected to the motor 3, the inverter ECU 14, and the battery ECU 16 (abnormality detection). means).

  The above-mentioned abnormality includes abnormality of each sensor such as the rotation speed sensor 15 of the motor 3, the temperature sensor of the inverter 10, and the temperature sensor, voltage sensor, and current sensor of the battery 11, and the electric power stored in the battery 11. This includes the abnormal drop of the voltage, the leakage in the power supply circuit 13, the insulation resistance drop (insulation abnormality), the overvoltage, the abnormal high voltage interlock function, the operation of the emergency stop button of the battery 11 and the crash sensor, and the like.

And vehicle ECU20 performs the three-phase short circuit of the inverter 10, when the abnormality mentioned above in the electric power supply circuit 13 is detected (three-phase short circuit means).
Specifically, as shown in FIG. 2, when performing a three-phase short circuit of the inverter 10, all of the element groups including one of the switching elements 12 d to 12 f among the pair of switching elements of each phase of the inverter 10 are turned on. All the element groups including the other switching elements 12a to 12c are turned off. Alternatively, the three-phase short circuit of the inverter 10 may be executed by setting all the element groups including the one switching elements 12d to 12f to the OFF state and setting all the element groups including the other switching elements 12a to 12c to the ON state. .

Here, in the hybrid vehicle including the truck as the vehicle 1 of the present embodiment, the shift by the transmission 5 cannot be performed due to the influence of the drag torque (also referred to as drag torque) generated in the motor 3 due to the three-phase short circuit of the inverter 10. There is a problem. The details will be described below.
First, according to the drag torque characteristic of the motor 3 at the time of the three-phase short circuit of the inverter 10 shown in FIG. 3, in the high rotation region where the motor rotation speed N is N2 (for example, 1000 rpm) or more, dragging is performed regardless of the motor rotation speed N. The torque T is a relatively small and substantially constant value T2 (for example, about −50 N · m). That is, a flat characteristic in which the drag torque T becomes substantially constant appears in the drag torque characteristic in the region where the motor rotation speed N is equal to or higher than the predetermined rotation speed.

  On the other hand, in the low rotation range where the motor rotation speed N is less than N2, as the motor rotation speed N decreases, the drag torque T gradually increases in the negative direction, that is, in the reverse rotation direction of the normal rotation direction of the motor 3. That is, in the drag torque characteristic in the region where the motor rotation speed is less than the predetermined rotation speed, a gradual increase characteristic in which the drag torque T gradually increases in the negative direction appears.

  More specifically, as shown in FIG. 3, the drag torque T increases exponentially in the negative direction in the low rotation region of the motor rotation speed N where the gradually increasing characteristic appears. For example, in a region where the motor rotation speed N during idling of the vehicle 1 is less than N2 and greater than or equal to N1 (for example, about 500 rpm), the drag torque T is a relatively small value T1 (for example, about −60 N · m). However, in the rotation speed region where the motor rotation speed N is less than N1, the drag torque T starts to increase rapidly from T1 in the negative direction as the motor rotation speed N gradually decreases.

Therefore, the low rotation speed region where the gradually increasing characteristic appears includes a rotation speed region (first region) in which the drag torque T increases in a negative direction relatively slowly, and a drag torque T in a negative direction substantially and rapidly. And a rotational speed region (second region) that increases.
Next, FIG. 4 is a diagram showing changes in the input shaft rotational speed n of the transmission 5 in time series when a shift (shift change) by the transmission 5 is performed.
As shown by a solid line in FIG. 4, in the normal state when the inverter 10 is not short-circuited in three phases, the transmission 5 is changed from a second gear or the like where the input shaft rotational speed n becomes n1 at a time t1 to a first gear or the like. Assume that a downshift has started. In this case, the input shaft rotational speed n gradually increases due to the driving force of the engine 2 or the motor 3 and reaches the target rotational speed nt of the first gear at time t2, and the gears in the transmission 5 are synchronized. This completes the desired shift.

  On the other hand, as indicated by a broken line in FIG. 4, it is assumed that a shift-down shift similar to the above is started in the transmission 5 when the inverter 10 is short-circuited. For example, even if the clutch 4 is disconnected and the driving force of the engine 2 is not transmitted to the input shaft of the transmission 5 and the vehicle 1 is gradually decelerating or the clutch 4 is connected to the engine 2. It is assumed that the driver of the vehicle 1 does not step on the accelerator and the vehicle 1 is traveling on a flat road while gradually decelerating by inertia.

  In this case, the rotor (not shown) of the motor 3 rotates inertially, and due to the influence of the drag torque described above, the input shaft rotational speed n gradually decreases as time elapses and decreases to n2 at time t2, and the first speed The target rotational speed nt of the gear is not reached. Therefore, gear synchronization in the transmission 5 becomes impossible, and a desired shift cannot be realized.

  For the above reasons, the vehicle 1 at the time of the three-phase short circuit may fail to shift down due to the influence of the gradually increasing characteristic of the drag torque T generated in the motor 3, and may further damage the transmission 5. For this reason, at the time of a three-phase short circuit, in order to prevent the transmission 5 from being damaged, the vehicle 1 is always forced to travel in a fixed gear stage such as a second gear.

In order to solve such a problem, in the present embodiment, a shift control that can realize a shift by the transmission 5 even when a three-phase short circuit of the inverter 10 is performed (shift control prohibiting means).
Hereinafter, the shift control of the present embodiment will be described in detail with reference to the flowchart shown in FIG.

  First, when this control routine is started, in S1 (S represents a step, the same shall apply hereinafter), the inverter ECU 14 determines whether or not the abnormality in the power supply circuit 13 described above has been detected (abnormality detection step). . If no abnormality is detected and the determination result is false (No), this control routine ends (end). On the other hand, if an abnormality is detected and the determination result is true (Yes), the process proceeds to S2.

In S2, a three-phase short circuit of the inverter 10 is executed (three-phase short circuit step), and then the process proceeds to S3.
In S3, the inverter ECU 14 reads the motor rotation speed Nc detected by the rotation speed sensor 15 of the motor 3 (rotation speed detection step), and whether the motor rotation speed Nc is equal to or greater than the set rotation speed Ns (Nc ≧ Ns). Determine whether or not.

  For example, as shown in FIG. 3, the set rotational speed Ns can be set to a rotational speed at which a gradually increasing characteristic appears in the motor torque characteristic as the motor rotational speed N gradually decreases. For example, the set rotational speed Ns may be set to a motor rotational speed N2 (for example, 1000 rpm) at which the drag torque starts to increase. According to this, since the influence of the drag torque in the shift control during the three-phase short circuit can be surely prevented, the control reliability can be improved. For example, the set rotation speed Ns may be set to a motor rotation speed N1 (for example, 500 rpm) at which the drag torque starts to increase substantially and rapidly. According to this, since the rotation speed range in which the shift control can be performed can be maximized, the controllability of the shift control during the three-phase short circuit can be improved.

In S3, when the motor rotational speed Nc ≧ the set rotational speed Ns is established and the determination result is true (Yes), the process proceeds to S4. On the other hand, when Nc ≧ Ns is not established and the determination result is false (No), the process proceeds to S5.
In S4, the vehicle ECU 20 permits the shift control by the transmission ECU 18, and thereafter ends (ends) this control routine.
In S5, the vehicle ECU 20 prohibits the shift control by the transmission ECU 18, and executes S2 again (shift control prohibiting step). Note that the shift control prohibited in S5 can include both upshifting and downshifting.

  As described above, in the present embodiment, after an abnormality is detected in the power supply circuit 13, the inverter 10 is short-circuited for three phases, and the above-described shift control is executed. Since the drag torque is comparatively small, the shift control is performed only in the motor rotation speed region that does not substantially affect the shift control, so that the transmission accompanying the inadvertent shifting at the time of the three-phase short circuit of the inverter 10 Thus, more reliable shift control can be performed while reducing the mechanical load 5 and preventing damage to the transmission 5. Therefore, even when the inverter 10 is in a three-phase short circuit, it is not necessary to always perform traveling at a fixed gear stage in which shift down is prohibited in the shift control, and the vehicle 10 can be improved in traveling performance due to the three-phase short circuit of the inverter 10. The impact can be minimized.

  Specifically, in S3 of the shift control routine, when Nc ≧ Ns is established when the inverter 10 is in a three-phase short circuit, and it is determined that the motor rotational speed Nc is equal to or higher than the set rotational speed Ns, the clutch 4 is engaged. Even if the driving force of the engine 2 is transmitted to the input shaft of the transmission 5 and the vehicle 1 is gradually accelerating or the clutch 4 is engaged, the driver of the vehicle 1 does not depress the accelerator. It is assumed that the vehicle 1 is traveling on a downhill road while gradually accelerating by inertia.

  Therefore, the motor rotation speed N is positioned in the rotation speed region of the flat characteristic shown in FIG. For this reason, by permitting a shift by the transmission 5 in S4, the gears in the transmission 5 can be synchronized smoothly as in the normal case where the inverter 10 is not three-phase short-circuited. It is possible to freely change both down and up.

  On the other hand, in S3 of the shift control routine, when it is determined that Nc ≧ Ns is not established when the inverter 10 is short-circuited, that is, Nc <Ns is established, as described in FIG. 4, the clutch 4 is disengaged. Even if the driving force of the engine 2 is not transmitted to the input shaft of the transmission 5 and the vehicle 1 is gradually decelerating or the clutch 4 is engaged, the driver of the vehicle 1 depresses the accelerator. It is assumed that the vehicle 1 is traveling on a flat road while gradually decelerating by inertia.

  Therefore, the motor rotational speed Nc is positioned in the rotational speed region of the gradually increasing characteristic shown in FIG. For this reason, by prohibiting the shift by the transmission 5 in S5, it is ensured that the mechanical load of the transmission 5 is increased by forcibly synchronizing the gears in the transmission 5 and that the transmission 5 is damaged. Can be prevented.

  Even when the motor rotational speed Nc is positioned in the rotational speed range of the gradual increase characteristic, when the driving state of the vehicle 1 changes, the disconnected clutch 4 is connected and the driving force of the engine 2 is increased. When the vehicle 1 is transmitted to the input shaft of the transmission 5 or when the traveling environment of the vehicle 1 changes and the vehicle 1 starts traveling on a downhill road from a flat road, the vehicle 1 starts to accelerate gradually, and as a result, the motor For example, a case where the motor rotation speed Nc of 3 starts to increase gradually is assumed.

  In this case, since the motor rotation speed Nc shifts from the gradually increasing characteristic of the drag torque characteristic to the flat characteristic, Nc ≧ Ns is established in the determination of S3 that is executed again, and thus the shift by the transmission 5 is permitted in S4. The Thus, the shift control adjusts the shift timing in the transmission 5 until the motor rotation speed Nc is positioned from the gradually increasing characteristic to the flat characteristic, so that even if the shift by the transmission 5 is temporarily prohibited, The driver is not forced to travel with the 2nd gear fixed at all times, and can freely change both downshift and upshift according to changes in the driving state and traveling environment of the vehicle 1. Become.

  Further, by setting the set rotational speed Ns in the rotational speed region where the drag torque generated in the motor 3 starts to gradually increase as the rotational speed of the motor 3 gradually decreases, the boundary at which the motor rotational speed N shifts from the gradually increasing characteristic to the flat characteristic. Therefore, it is possible to reliably permit and prohibit the shift in the transmission 5. Therefore, it is possible to more appropriately control the shift timing in the transmission 5 while protecting the transmission 5 more reliably.

As described above, the shift control of the present embodiment is such that the drag torque of the motor 3 is relatively small in order to reduce the influence of the drag torque of the motor 3 caused by the three-phase short circuit of the inverter 10. Shifting using the high rotation speed region of the input shaft of the transmission 5 is performed.
Such a high rotational speed region is often already mounted on the vehicle 1 as a speed change application used when a so-called endurance brake is actuated or kicked down (when the accelerator is depressed). Therefore, it is possible to easily implement the shift control of the present embodiment in the vehicle 1 by extending this existing application or system.

<Modification>
Hereinafter, a modified example of the drive control according to the first embodiment will be described in detail with reference to FIG.
In the drive control according to the modified example, if the detected motor rotation speed Nc is less than the set rotation speed Ns immediately before the shift control prohibiting step (S3) shown in FIG. Correction control for increasing the number N (rotational speed correction means: S6) is performed. Thereby, the frequency which transfers to the shift control prohibition step of S5 can be reduced.

Specifically, in S3, the set rotational speed Ns is set to N1 shown in FIG. 3, and the rotational speed correction control of the motor 3 shown in FIG. 6B is performed.
In S6, first, it is determined whether or not the motor rotation speed Nc is equal to or higher than N1 that is the set rotation speed in S3 and less than N2 (shown in FIG. 3) that is the rotation speed at which drag torque starts to be generated (S6-1). ).

  When the motor rotational speed Nc is less than N2, as the correction control for increasing the rotational speed of the motor 3, for example, downshift control for forcibly performing downshifting in the transmission 5 is performed (S6-2). This correction control is not particularly limited to the downshift control. Thereby, the frequency of transition to the shift control prohibiting step of S5 can be reliably reduced.

Second Embodiment
Next, drive control according to the second embodiment will be described with reference to the drawings. FIG. 7 is a flowchart illustrating control that is a main part of drive control according to the second embodiment. The configurations and control steps already described are denoted by the same reference numerals, and detailed description thereof is omitted.

As shown in FIG. 7, the present embodiment includes S7 (shift-up control prohibiting step) for prohibiting shift-up of shift control.
In S7, first, the target rotational speed nt of the input shaft of the transmission 5 in the upshift control of the transmission 5 is calculated (S7-1). The target rotational speed nt can be calculated based on, for example, the detected motor rotational speed Nc.

Next, it is determined whether the calculated target rotational speed nt is less than the set rotational speed Ns of the motor 3 that is not affected by the drag torque (S7-2).
Specifically, in S7-2, the set rotation speed Ns is set to N2 shown in FIG. 3, and the shift-up prohibition control of the transmission 5 shown in FIG. 7 is performed.
When the calculated target rotational speed nt of the transmission 5 is less than N2, upshifting is prohibited in the shift control (S7-3). At this time, downshifting of the transmission 5 is not prohibited.

  By the way, normally, when the transmission 5 is shifted up, the rotational speed n of the input shaft of the transmission 5 is controlled to gradually decrease. Therefore, even if the rotational speed of the motor 3 at the time before the upshift is N2 or more that is not affected by the drag torque, the rotational speed of the motor 3 is gradually reduced by the upshifting performed by the transmission 5. As a result, the drag torque decreases to an increasing rotational speed, and the upshifting in the transmission 5 may fail.

On the other hand, in the drive control according to the present embodiment, when the calculated target rotational speed nt is less than N2, the shift-up is prohibited in the shift control, so that the influence of the drag torque during the shift-up control is ensured. Can be prevented.
The drive control (S7) according to the present embodiment may be performed immediately after S2 of the drive control according to the first embodiment. Further, the drive control S7 may be implemented by replacing S3 to S5 according to the first embodiment.

The present invention is not limited to the above-described embodiments, and various modifications are possible.
For example, in the present embodiment, the case where the downshift by the transmission 5 cannot be performed when the inverter 10 is three-phase short-circuited as illustrated by a broken line in FIG. 4 has been described. However, the drag torque characteristic of the motor 3 is a characteristic characteristic of the motor 3, and is not limited to the characteristic shown in FIG. Therefore, it is assumed that not only downshifting by the transmission 5 but also upshifting cannot be performed when the inverter 10 is three-phase short-circuited. Even in this case, by performing the shift control of the present embodiment, it is possible to appropriately control the shift timing by the transmission 5 and perform the shift up while reliably protecting the transmission 5.

  In the present embodiment, the set rotational speed Ns is set in the rotational speed region where the drag torque generated in the motor 3 starts to gradually increase as the rotational speed of the motor 3 gradually decreases. However, the present invention is not limited to this, for example, the set rotational speed Ns is set to the motor rotational speed N1 when the vehicle 1 is idling, and the set rotational speed Ns is at least near the boundary where the motor rotational speed N shifts from a gradually increasing characteristic to a flat characteristic. May be provided. Even in this case, the shift timing by the transmission 5 can be appropriately controlled while protecting the transmission 5.

  Further, in this embodiment, detection of an abnormality in the power supply circuit 13 (abnormality detection means), three-phase short-circuit control (three-phase short-circuit means) for setting the inverter in a three-phase short-circuit state, and the motor 3 detected by the rotation speed sensor 15 All the shift control (shift control means) for permitting or prohibiting the shift by the transmission 5 in accordance with the number of rotations is performed by the inverter ECU 14. However, the detection, determination, and command execution may be executed by a host ECU or BCU other than the inverter ECU 14, or may be realized by sending an execution signal to the inverter ECU 14 by CAN communication or the like.

Moreover, the cause of abnormality of the power supply circuit 13 enumerated in this embodiment is not limited to these.
In addition, the vehicle 1 of the present embodiment is a parallel hybrid truck using the engine 2 and the motor 3 as drive sources, but the present invention is not limited to the truck and can be applied to all hybrid vehicles.

1 vehicle (hybrid vehicle)
2 Engine 3 Motor (electric motor)
4 Clutch 5 Transmission 10 Inverter 11 Battery 13 Power Supply Circuit 15 Rotational Speed Sensor (Rotational Speed Detection Means)
20 vehicle ECU (abnormality detection means, three-phase short-circuit means, shift control means, shift control prohibition means, rotation speed correction means)

Claims (9)

An engine that is a driving source of the vehicle;
An electric motor connected to the output side of the engine via a clutch and capable of generating electricity as a driving source of the vehicle;
A transmission that is directly connected to the output side of the electric motor and performs a shift of the vehicle;
A battery capable of storing electric power for driving the electric motor;
An inverter that converts direct current and alternating current of the electric power between the battery and the electric motor;
Shift control means for controlling the shift of the transmission;
An abnormality detection means for detecting an abnormality in a power supply circuit including the electric motor, the inverter, and the battery;
When an abnormality is detected by the abnormality detection means, three-phase short-circuit means for setting the inverter in a three-phase short-circuit state;
A rotational speed detection means for detecting the rotational speed of the electric motor;
When the three-phase short-circuit means causes the inverter to be in the three-phase short-circuit state, when the rotation speed of the electric motor detected by the rotation speed detection means is less than a predetermined set rotation speed, a shift by the transmission is performed. Shift control prohibiting means for prohibiting
A drive control device comprising: An engine that is a driving source of the vehicle;
An electric motor connected to the output side of the engine via a clutch and capable of generating electricity as a driving source of the vehicle;
A transmission that is directly connected to the output side of the electric motor and performs a shift of the vehicle;
A battery capable of storing electric power for driving the electric motor;
An inverter that converts direct current and alternating current of the electric power between the battery and the electric motor;
Shift control means for controlling the shift of the transmission;
An abnormality detection means for detecting an abnormality in a power supply circuit including the electric motor, the inverter, and the battery;
When an abnormality is detected by the abnormality detection means, three-phase short-circuit means for setting the inverter in a three-phase short-circuit state;
When the three-phase short-circuit means causes the inverter to be in the three-phase short-circuit state, the shift control means shifts when the target speed of the upshift control in the shift control means is less than a predetermined set speed. And a shift control prohibiting unit that prohibits the upshift control. The drive control apparatus according to claim 1, further comprising a rotation speed correction unit that increases a rotation speed of the electric motor .   2. The drive control device according to claim 1, wherein the set rotational speed is set in a rotational speed region in which drag torque generated in the electric motor begins to gradually increase as the rotational speed of the electric motor gradually decreases.   The hybrid vehicle provided with the drive control apparatus as described in any one of Claims 1 thru | or 4. An electric motor connected to the output side of the engine, which is a driving source of the vehicle, via a clutch and directly connected to the input side of the transmission, which is a driving source of the vehicle and capable of generating power, and electric power for driving the electric motor An abnormality detecting step of detecting an abnormality in a power supply circuit including a battery capable of storing the power, and an inverter that performs direct current and alternating current conversion of the electric power between the battery and the electric motor,
A shift control step for performing shift control of the transmission;
When an abnormality is detected by the abnormality detection step, a three-phase short circuit step for setting the inverter in a three-phase short circuit state;
A rotational speed detection step for detecting the rotational speed of the electric motor;
When the inverter is brought into the three-phase short circuit state by the three-phase short circuit step, when the rotation speed of the motor detected by the rotation speed detection step is less than a predetermined set rotation speed, the shift by the transmission is performed. Shift control prohibiting step for prohibiting,
A drive control method comprising: An electric motor connected to the output side of the engine, which is a driving source of the vehicle, via a clutch and directly connected to the input side of the transmission, which is a driving source of the vehicle and capable of generating power, and electric power for driving the electric motor An abnormality detecting step of detecting an abnormality in a power supply circuit including a battery capable of storing the power, and an inverter that performs direct current and alternating current conversion of the electric power between the battery and the electric motor,
A shift control step for performing shift control of the transmission;
When an abnormality is detected by the abnormality detection step, a three-phase short circuit step for setting the inverter in a three-phase short circuit state;
When the inverter is brought into the three-phase short circuit state by the three-phase short circuit step, when the target rotational speed of the shift-up shift control in the shift control step is less than a predetermined set rotational speed, the shift by the shift control means A shift control prohibiting step for prohibiting the upshift control;
A drive control method comprising: The drive control method according to claim 6, further comprising a rotation speed correction step for increasing the rotation speed of the electric motor .   The drive control method according to any one of claims 6 to 8, wherein the set rotational speed is set in a rotational speed region in which drag torque generated in the electric motor starts to gradually increase as the rotational speed of the electric motor gradually decreases. .

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