JP6382512B2 - vehicle - Google Patents

Description

  The present invention relates to a vehicle having an internal combustion engine and an electric motor as a power source for traveling.

  Patent Document 1 provides a hybrid vehicle capable of responding to a demand for a large braking force without using a resistor for battery deterioration or surplus power discharge while an electric motor or an engine is traveling alone. ([0006], summary).

  In order to achieve this object, in Patent Document 1, the braking request detector 30 detects a braking request while the motor 15 is traveling alone. Next, the remaining battery level is calculated by the remaining battery level detection unit 26 from the battery voltage, current, temperature, specific gravity, etc., and the maximum motor regenerative torque is calculated from the vehicle speed and the remaining battery level, taking into account overcharge, rapid charging, etc. And ask. When the shift lever position is in the “R” or “D” range, regenerative braking is performed according to the brake depression amount. On the other hand, in the case of a larger braking request such as the “2” and “L” ranges, regenerative braking is performed with the maximum motor regenerative torque, and the clutch 13 is engaged and braking with the engine brake is used together (summary).

  In the first to fourth embodiments of Patent Document 1, the motor regenerative torque Tbm (target value of the regenerative torque) is set to the regenerative torque Tb or the motor maximum regenerative torque Tbm max (S7, S8, S10 in FIG. 3, FIG. 5 S14, S16-S18, S9, S10, S12 in FIG. 9, S14, S16-S18 in FIG. The regenerative torque Tb corresponds to the depression amount of the brake 32 (S6, [0019] in FIG. 3, S8, [0034] in FIG. 9) or the depression amount and shift position of the brake 32. (S13 in FIG. 4, [0027], [0037]).

  Moreover, in 1st Embodiment of patent document 1, when a shift position is "L", the clutch 13 is engaged and braking by an engine brake is performed (FIG. 3, S11, S12, [0021], [0022] ). On the other hand, when the shift position is not “L”, the clutch 13 is released and the engine brake is not operated (S9 in FIG. 3, [0019]). In the third embodiment, processing similar to that in the first embodiment is performed depending on whether the shift position is “2” or “L” (S11, S13 to S17, [0034] to [0036 in FIG. 9). ]).

  Furthermore, in the second and fourth embodiments of Patent Document 1, when the regenerative torque Tb exceeds the motor maximum regenerative torque Tbm max and the shift position is not “R”, the difference between the two is the engine brake torque Tbe, and the clutch 13 is Drive (S14, S15, S18, S23 in FIGS. 5 and 10). On the other hand, when the regenerative torque Tb does not exceed the motor maximum regenerative torque Tbm max or when the shift position is “R”, the clutch 13 is released and the engine brake is not operated (S14, S15, and S19 in FIGS. 5 and 10). ).

Japanese Patent Laid-Open No. 06-055941

  According to the disclosure of Patent Document 1 as described above, even when the engine 11 is traveling alone, the clutch 13 may be released and the engine brake may not be operated. In this case, there is a possibility that the driver may feel uncomfortable due to the engine brake not operating even though the engine 11 is operating. Alternatively, as the clutch 13 is released, the rotational speed (the number of revolutions per unit time) of the engine 11 decreases gradually, and the correlation between the rotational speed and the vehicle speed disappears. As a result, the subsequent speed change for reacceleration is not performed smoothly, and the driver may feel uncomfortable.

  Further, in Patent Document 1, even when the motor 15 is traveling alone (when the engine is not operating), the engine brake may be operated by engaging the clutch 13. In this case, there is a possibility that the driver feels uncomfortable due to the generation of vibrations or sounds that accompany the sudden start of the engine even though the motor 15 has been traveling alone. In addition, there is a possibility of causing engine deterioration due to suddenly operating the engine brake.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a vehicle capable of suitably executing deceleration control in a vehicle having an internal combustion engine and an electric motor.

A vehicle according to the present invention includes an internal combustion engine mechanically connected to a first drive wheel that is one of a front wheel and a rear wheel, and a second drive wheel that is the other of the front wheel and the rear wheel. Connected to the motor, a drive control device for controlling the internal combustion engine and the motor, and a target power input unit for inputting from a driver for setting target power generated by the internal combustion engine and the motor. The drive control device sets the target power generated by the internal combustion engine and the electric motor based on the input to the target power input unit, and corresponds to the input to the target power input unit When the target power to be negative power that decelerates the vehicle and the vehicle speed is equal to or higher than a predetermined vehicle speed , the drive control device includes the target power and the negative power generated by the internal combustion engine. Due to the difference The first target regenerative power that is the target regenerative power of the corresponding motor and the target regenerative power of the motor that is obtained based on the power consumption of the electric operation auxiliary machine of the vehicle or another motor different from the motor. Regenerative power selection control is performed in which the larger one of the two target regenerative powers is the target regenerative power of the electric motor.

  According to the present invention, when the target power corresponding to the input to the target power input unit by the driver is negative power that decelerates the vehicle, it corresponds to the difference between the target power and the negative power generated by the internal combustion engine. The larger one of the first target regenerative power to be generated and the second target regenerative power obtained based on the power consumption of another electric motor different from the electric operation auxiliary machine or electric motor of the vehicle is used as the target regenerative power of the motor. Perform selection control. As a result, even when the negative power (braking force) required by the driver is exceeded, it is possible to generate power consumption of the electric auxiliary machine or the like. For this reason, it is possible to perform regeneration by the electric motor while generating negative power in the internal combustion engine. Therefore, it is possible to avoid the adverse effects associated with the fact that the negative power of the internal combustion engine is not used for deceleration despite the internal combustion engine being operated.

  Further, even in a state where negative power is generated in the internal combustion engine, regeneration by the electric motor is continued, and power consumption of an electrically operated auxiliary machine or the like is generated. For this reason, it becomes easy to secure the required power until the vehicle stops or after the stop, and the convenience for the user can be improved.

  The drive control device sets an upper limit negative power, which is an upper limit value of the negative power generated in the second drive wheel, based on a vehicle speed, and the electric motor prevents the target regenerative power from exceeding the upper limit negative power. May be controlled. For example, if an attempt is made to keep the regenerative power by the motor constant, the regenerative power (torque, etc.) of the motor becomes excessive at low vehicle speeds (low rotation speed), and negative power by the motor may increase, giving the user a sense of discomfort. is there. According to the present invention, the target regenerative power of the electric motor is controlled so as not to exceed the upper limit negative power corresponding to the vehicle speed. For this reason, it becomes possible to avoid the user's uncomfortable feeling accompanying the increase in regenerative power at low vehicle speeds.

  The drive control device includes: a first driving wheel driving state that drives only the first driving wheel or both the first driving wheel and the second driving wheel; and a second driving wheel that drives only the second driving wheel. When the vehicle speeds are equal, the drive control device can increase the deceleration in the first drive wheel drive state more than the deceleration in the second drive wheel single drive state. Also good. This makes it easy to secure the regenerative power when the first drive wheel drive state is set (even if the regenerative power is somewhat increased), and makes it easy to set the regenerative power appropriately when the second drive wheel is driven alone. It becomes possible.

  The vehicle includes a power storage device that supplies power to the electric motor and charges regenerative power of the motor, and the drive control device determines whether or not to execute the regenerative power selection control. A charge amount threshold that is a threshold of the charge amount of the device is set, and when the charge amount falls below the charge amount threshold, the regenerative power selection control is executed, and when the charge amount exceeds the charge amount threshold, the regeneration amount Power selection control may be prohibited.

  Thus, regenerative power selection control is performed only when the charge amount of the power storage device is lower than the charge amount threshold value, that is, when there is a high possibility that the power storage device needs to be charged. For this reason, when the regenerative power selection control is prohibited, it is possible to make it difficult for the user to feel uncomfortable with the deceleration of the vehicle accompanying the generation or increase of the regenerative power for regeneration.

  The target power input unit includes an accelerator pedal and a brake pedal, and the drive control device determines that the amount of operation of the accelerator pedal and the brake pedal is zero. It's okay. As a result, regenerative power selection control is performed in the deceleration control when the driver does not operate the accelerator pedal and the brake pedal. For this reason, it is possible to flexibly control the deceleration in a state where both pedals are not operated.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to perform suitably the deceleration control in the vehicle which has an internal combustion engine and an electric motor.

1 is a schematic configuration diagram of a vehicle drive system and its surroundings according to an embodiment of the present invention. It is a flowchart of deceleration torque adjustment control in the embodiment. It is a flowchart (detail of S5 of FIG. 2) of the engine normal deceleration control. It is a figure which shows an example of the relationship between the engine torque in the said engine driving | running | working normal deceleration control, the target motor torque, and the target vehicle deceleration torque. It is the 1st flowchart (details of S6 of Drawing 2) of regeneration reinforcement control. It is the 2nd flowchart (details of S6 of Drawing 2) of the above-mentioned regeneration reinforcement control. It is a figure which shows an example of the relationship between the engine torque in the said regeneration reinforcement | strengthening control, a target motor torque, and a target vehicle deceleration torque. It is a figure which shows an example of the relationship between the vehicle speed in the said regeneration reinforcement | strengthening control, a target vehicle deceleration torque, etc. FIG. It is a flowchart (detail of S7 of FIG. 2) of the deceleration control at the time of RWD. It is a figure which shows an example of the relationship between the target motor torque and the target vehicle deceleration torque in the said deceleration control at the time of RWD. It is a schematic block diagram of the drive system of the vehicle which concerns on the modification of this invention, and its periphery.

I. One Embodiment [1. Constitution]
(1-1. Overall configuration)
FIG. 1 is a schematic configuration diagram of a drive system of a vehicle 10 and its periphery according to an embodiment of the present invention. As shown in FIG. 1, the vehicle 10 includes an engine 12 and a first traveling motor 14 that are arranged in series on the front side of the vehicle 10, and second and third traveling motors 16 and 18 that are arranged on the rear side of the vehicle 10. , A high voltage battery 20 (hereinafter also referred to as “battery 20”), first to third inverters 22, 24, 26, a drive electronic control device 28 (hereinafter referred to as “drive ECU 28” or “ECU 28”), and a supplement. Machine 29.

  Hereinafter, the first traveling motor 14 is also referred to as “first motor 14”, “motor 14”, or “front motor 14”. The second traveling motor 16 is also referred to as “second motor 16”, “left motor 16”, “motor 16”, or “rear motor 16”. Further, the third traveling motor 18 is also referred to as “third motor 18”, “right motor 18”, “motor 18”, or “rear motor 18”.

  The engine 12 and the first motor 14 transmit a driving force (hereinafter referred to as “front wheel driving force Ff”) to the left front wheel 32 a and the right front wheel 32 b (hereinafter collectively referred to as “front wheel 32”) via the transmission 30. The engine 12 and the first motor 14 constitute a front wheel drive device 34 (steering wheel drive device).

  The output shaft of the second motor 16 is connected to the rotation shaft of the left rear wheel 36a, and transmits driving force to the left rear wheel 36a. The output shaft of the third motor 18 is connected to the rotation shaft of the right rear wheel 36b, and transmits the driving force to the right rear wheel 36b. Reducers (not shown) may be arranged between the second motor 16 and the left rear wheel 36a and between the third motor 18 and the right rear wheel 36b. The second and third motors 16 and 18 constitute a rear wheel drive device 38 (non-steered wheel drive device). Hereinafter, the left rear wheel 36a and the right rear wheel 36b are collectively referred to as a rear wheel 36. The driving force transmitted from the rear wheel driving device 38 to the rear wheel 36 is referred to as a rear wheel driving force Fr.

  For example, when the vehicle 10 is at a low vehicle speed, the second and third motors 16 and 18 are driven. When the vehicle 10 is at a medium vehicle speed, the engine 12 and the second and third motors 16 and 18 are driven. In addition, the engine 12 and the first motor 14 are driven. When the vehicle speed is low, power is generated by the first motor 14 by driving the first motor 14 with the engine 12 in a state where the engine 12 and the transmission 30 are disconnected (or connected) by a clutch (not shown). The generated power can be supplied to the second and third motors 16 and 18 or the auxiliary machine 29 or the battery 20 can be charged. In other words, the first motor 14 can also be used as a generator.

  The high-voltage battery 20 supplies power to the first to third motors 14, 16, 18 via the first to third inverters 22, 24, 26, and from the first to third motors 14, 16, 18. The regenerative power Preg is charged.

  The drive ECU 28 controls the engine 12 and the first to third inverters 22, 24, and 26 based on outputs from various sensors and electronic control devices (hereinafter referred to as “ECU”), and thereby the engine 12 and the first Controls the outputs of the third motors 14, 16, and 18. The drive ECU 28 includes an input / output unit 40, a calculation unit 42, and a storage unit 44. The drive ECU 28 may be a combination of a plurality of ECUs. For example, a plurality of ECUs provided corresponding to the engine 12 and the first to third motors 14, 16, and 18, and an ECU that manages the driving states of the engine 12 and the first to third motors 14, 16, and 18, respectively. The drive ECU 28 may be configured as described above.

  The ECU 28 switches “RWD” (Rear Wheel Drive), “FWD” (Front Wheel Drive) and “AWD” (All Wheel Drive) as the “driving state” of the vehicle 10. . RWD and FWD are both two-wheel drive (2WD), and AWD is four-wheel drive (4WD). Further, the ECU 28 performs regeneration by at least one of the first to third travel motors 14, 16, and 18 according to the immediately preceding drive state when the vehicle 10 is decelerated. For this reason, below, the wording of RWD, FWD, and AWD is used also about the utilization state of the engine 12 and the 1st-3rd motors 14, 16, and 18 at the time of regeneration.

  Examples of various sensors output to the drive ECU 28 include a vehicle speed sensor 50, an accelerator pedal opening sensor 52, a brake pedal opening sensor 54, an SOC sensor 56, a motor rotation speed sensor 58, an engine rotation speed sensor 60, and a current sensor. 62 and a shift position sensor 64.

  The auxiliary machine 29 is an electrically operated auxiliary machine (an auxiliary machine operated by electricity) that is operated by electric power from the battery 20. As the auxiliary machine 29, for example, an air conditioner and / or a water pump (for cooling the engine 12) (not shown) are included. When the auxiliary machine 29 includes a step-down DC / DC converter, a 12V battery, a drive ECU 28 and other ECUs (not shown) may be included.

(1-2. Configuration and function of each part)
The engine 12 is, for example, a 6-cylinder engine, but may be other engines such as a 2-cylinder, 4-cylinder, or 8-cylinder type. The engine 12 is not limited to a gasoline engine, but may be an engine such as a diesel engine or an air engine.

  The first to third motors 14, 16 and 18 are, for example, a three-phase AC brushless type, but may be other motors such as a three-phase AC brush type, a single-phase AC type, and a DC type. The specifications of the first to third motors 14, 16, 18 may be equal or different. Further, when a reduction gear (not shown) is arranged between the second motor 16 and the left rear wheel 36a and between the third motor 18 and the right rear wheel 36b, and the reduction ratio of each reduction gear is variable, The wheel 36a and the right rear wheel 36b may be driven by one traveling motor.

  The first to third inverters 22, 24, 26 have a three-phase bridge configuration, perform DC / AC conversion, convert DC to three-phase AC, and convert the first to third motors 14, 16, On the other hand, the high-voltage battery 20 is supplied with the direct current after the alternating current / direct current conversion accompanying the regeneration operation of the first to third motors 14, 16, 18.

  The high voltage battery 20 is a power storage device (energy storage) including a plurality of battery cells, and for example, a lithium ion secondary battery, a nickel hydride secondary battery, or a capacitor can be used. In this embodiment, a lithium ion secondary battery is used. A DC / DC converter (not shown) is provided between the first to third inverters 22, 24, 26 and the high voltage battery 20, and the output voltage of the high voltage battery 20 or the outputs of the first to third motors 14, 16, 18 is provided. The voltage may be boosted or lowered.

  As a drive system configuration of the vehicle 10, for example, the one described in Japanese Patent Application Laid-Open No. 2012-0500185 can be used. For example, as in JP 2012-050185 A, a hydraulic pump, solenoid, one-way clutch, hydraulic brake, etc. (not shown) are provided on the second and third motors 16 and 18 side, and are controlled by the drive ECU 28 as necessary. The operations of the second and third motors 16 and 18 can be controlled (see FIG. 13 of Japanese Patent Application Laid-Open No. 2012-0500185).

  The vehicle speed sensor 50 detects the vehicle speed V [km / h]. The accelerator pedal opening sensor 52 detects the opening of the accelerator pedal 70 (hereinafter referred to as “accelerator opening θap”). The brake pedal opening sensor 54 detects the opening of the brake pedal 72 (hereinafter referred to as “brake opening θbp”). The SOC sensor 56 detects the state of charge (SOC) [%] of the battery 20.

  The motor rotational speed sensor 58 detects the rotational speed Nmot per unit time of the first to third motors 14, 16, 18 (hereinafter also referred to as “rotational speed Nmot” or “motor rotational speed Nmot”) [rpm]. To do. The engine rotational speed sensor 60 detects the rotational speed Ne per unit time of the engine 12 (hereinafter also referred to as “rotational speed Ne” or “engine rotational speed Ne”) [rpm]. The current sensor 62 detects input / output currents of the motors 14, 16, 18 (hereinafter referred to as “motor current Imot”). The shift position sensor 64 is a position of the shift lever 74 (“P” as a parking range, “N” as a neutral range, “D” as a forward travel range, “R” as a reverse travel range, etc.) (hereinafter “ Shift position Ps ").

[2. Control during deceleration]
(2-1. Overview)
Next, deceleration torque adjustment control during deceleration of the vehicle 10 will be described. In the deceleration torque adjustment control, the vehicle 10 is decelerated according to the immediately preceding drive state (RWD, FWD, or AWD).

  FIG. 2 is a flowchart of deceleration torque adjustment control in the present embodiment. The ECU 28 controls the torque of the rear motors 16 and 18 (hereinafter also referred to as “motor torque Tmot” or “torque Tmot”) using the flow of FIG. 2. The motor torque Tmot here means the sum of the torques of the motors 16 and 18, but it is also possible to perform deceleration torque adjustment control for the torques of the motors 16 and 18.

The relationship between the torque Tmot of the motors 16 and 18 and the torque of the rear wheels 36a and 36b (hereinafter referred to as “wheel torque Tw”) is expressed by the following equation (1).
Tmot = (1 / R) · Tw (1)

  The wheel torque Tw means the sum of the torques of the rear wheels 36a and 36b, but it is also possible to perform deceleration torque adjustment control for the respective torques of the rear wheels 36a and 36b. In the formula (1), R is a reduction ratio of a reduction gear (not shown) disposed between the motor 16 and the rear wheels 36a and 36b (R is 1 when no reduction gear is provided). In the ECU 28, either the motor torque Tmot or the wheel torque Tw may be controlled.

  Each step S1-S7 of FIG. 2 is repeated for every predetermined calculation period.

  In steps S1 and S2 in FIG. 2, the ECU 28 determines whether or not a condition (deceleration torque adjustment condition) for adjusting the vehicle deceleration torque Tv [N · m] is satisfied. Specifically, in step S1, the ECU 28 determines whether or not the vehicle 10 is traveling (for example, whether or not the vehicle speed V exceeds 0 km / h).

  When the vehicle 10 is traveling (S1: YES), in step S2, the ECU 28 determines whether or not both the accelerator opening θap and the brake opening θbp are zero (in other words, the accelerator pedal 70 and the brake pedal 72). Is in the original position). When the accelerator opening degree θap and the brake opening degree θbp are both zero (S2: YES), the process proceeds to step S3. When the vehicle 10 is not traveling (S1: NO) or when the accelerator opening degree θap or the brake opening degree θbp is not zero (S2: NO), the processing in the current calculation cycle is finished.

  In step S3, the ECU 28 determines whether or not the driving state immediately before the vehicle 10 is FWD or AWD (in other words, whether or not the engine 12 is running). When the immediately preceding drive state is FWD or AWD (S3: YES), in step S4, the ECU 28 determines whether or not the battery SOC is equal to or greater than a predetermined threshold (hereinafter referred to as “SOC threshold THsoc” or “threshold THsoc”). Determine whether.

  When the SOC is equal to or greater than the threshold value THsoc (S4: YES), in step S5, the ECU 28 executes normal deceleration control during engine travel (hereinafter also referred to as “normal deceleration control”). When the SOC is not equal to or higher than the threshold THsoc (S4: NO), in step S6, the ECU 28 executes regenerative strengthening control (regenerative power selection control). The normal deceleration control will be described later with reference to FIGS. 3 and 4, and the regeneration enhancement control will be described later with reference to FIGS.

  Returning to step S3 in FIG. 2, when the driving state immediately before the vehicle 10 is RWD instead of FWD or AWD (S3: NO), in step S7, the ECU 28 executes RWD deceleration control. The RWD deceleration control will be described later with reference to FIGS.

(2-2. Normal deceleration control during engine running)
FIG. 3 is a flowchart of the normal deceleration control during engine running (details of S5 in FIG. 2). FIG. 4 is a diagram illustrating an example of the relationship between the engine torque Teng and the target motor torque Tmot_tar and the target vehicle deceleration torque Tv_tar in the normal deceleration control during engine running.

  The engine torque Teng here is converted into torque (wheel torque) at the front wheels 32a and 32b (wheel ends) in consideration of the reduction ratio of the transmission 30. Similarly, the target motor torque Tmot_tar is converted into torque (wheel torque) at the rear wheels 36a and 36b (wheel ends) in consideration of a reduction ratio of a reduction gear (not shown). The target vehicle deceleration torque Tv_tar is a total target value of the deceleration torque in the front wheels 32a and 32b and the rear wheels 36a and 36b.

  In step S11 of FIG. 3, the ECU 28 acquires detection values for calculation from various sensors. The calculation detection values here include, for example, the vehicle speed V, the motor rotation speed Nmot, the engine rotation speed Ne, the motor current Imot, and the shift position Ps.

  In step S12, the ECU 28 calculates the current vehicle deceleration torque Tv, engine torque Teng, and motor torque Tmot. The vehicle deceleration torque Tv is the sum of the engine torque Teng and the motor torque Tmot (Tv = Teng + Tmot). In the engine traveling normal deceleration control, torques Tv, Teng, and Tmot are all negative values, but can be processed as positive values.

  In step S13, the ECU 28 determines the target vehicle deceleration torque Tv_tar (hereinafter also referred to as “target deceleration torque Tv_tar” or “deceleration torque Tv_tar”) [N · m] and the motor torque limit value based on the vehicle speed V acquired in step S11. Tmot_lim (hereinafter also referred to as “torque limit value Tmot_lim” or “limit value Tmot_lim”) [N · m] is set. The setting of the deceleration torque Tv_tar and the limit value Tmot_lim will be described in the description with reference to FIG. 8 related to the regeneration enhancement control.

  In step S14, the ECU 28 determines whether or not the difference ΔT (= Tv_tar−Teng) between the target vehicle deceleration torque Tv_tar and the engine torque Teng is equal to or greater than the motor torque limit value Tmot_lim (in other words, the absolute value of the target vehicle deceleration torque Tv_tar). It is determined whether or not the difference | Tv_tar | − | Teng | of the absolute value of the engine torque Teng is equal to or smaller than the absolute value | Tmot_lim | of the motor torque limit value Tmot_lim).

  When the difference ΔT is equal to or greater than the limit value Tmot_lim (S14: YES), in step S15, the ECU 28 determines whether the engine torque Teng is smaller than the target vehicle deceleration torque Tv_tar (in other words, the absolute value of the engine torque Teng is the target vehicle deceleration). Whether the torque Tv_tar is larger than the absolute value). When the engine torque Teng is smaller than the target motor torque Tmot_tar (S15: YES), in step S16, the ECU 28 sets zero as the target motor torque Tmot_tar (Tmot_tar ← 0). When the engine torque Teng is not smaller than the target motor torque Tmot_tar (S15: NO), in step S17, the ECU 28 changes the target motor torque Tmot_tar according to the difference ΔT.

  If the difference ΔT is not greater than or equal to the limit value Tmot_lim in step S14 (S14: NO), in step S18, the ECU 28 sets the motor torque limit value Tmot_lim as the target motor torque Tmot_tar (Tmot_tar ← Tmot_lim).

  In the example of FIG. 4, in the case of “no shift” or “1-stage deceleration”, the engine torque Teng has not reached the target vehicle deceleration torque Tv_tar (S15 in FIG. 3: NO). In this case, the ECU 28 generates the motor torque Tmot according to the difference ΔT (S17, S18). Here, “no gear shift” means that the engine 12 has not shifted since the start of deceleration of the vehicle 10, and “one-stage deceleration” means that the engine 12 decelerated one stage after the start of deceleration of the vehicle 10. Means that

  On the other hand, in the case of “two-stage deceleration” in FIG. 4, the engine torque Teng exceeds the target vehicle deceleration torque Tv_tar (the difference between the absolute value of the target vehicle deceleration torque Tv_tar and the absolute value of the engine torque Teng is negative) ( S15: YES). Therefore, the ECU 28 does not generate motor torque Tmot (deceleration torque by the motors 16 and 18) (S16). Here, “two-stage deceleration” means that the engine 12 has been decelerated two stages from the start of deceleration of the vehicle 10.

  The deceleration in the example of FIG. 4 may be, for example, either deceleration by operating the shift lever 74 or automatic deceleration by the ECU 28 (the same applies to FIG. 7).

(2-3. Regeneration enhancement control)
(2-3-1. Overall flow)
5 and 6 are first and second flowcharts (details of S6 in FIG. 2) of the regeneration enhancement control. FIG. 7 is a diagram illustrating an example of the relationship between the engine torque Teng and the target motor torque Tmot_tar and the target vehicle deceleration torque Tv_tar in the regeneration enhancement control. FIG. 8 is a diagram illustrating an example of the relationship between the vehicle speed V and the target vehicle deceleration torque Tv_tar and the like in the regeneration enhancement control.

  In step S21 of FIG. 5, the ECU 28 acquires detection values for calculation from various sensors. The calculation detection values here include, for example, the vehicle speed V, the motor rotation speed Nmot, the engine rotation speed Ne, the motor current Imot, and the shift position Ps.

  In step S22, the ECU 28 calculates the current vehicle deceleration torque Tv, engine torque Teng, and motor torque Tmot, as in step S12. In step S23, the ECU 28 sets the target vehicle deceleration torque Tv_tar, the motor torque limit value Tmot_lim, and the auxiliary machine power compensation torque Tmot_min based on the vehicle speed V acquired in step S21. The target vehicle deceleration torque Tv_tar, the motor torque limit value Tmot_lim, and the auxiliary power compensation torque Tmot_min will be described later with reference to FIG.

  In step S24, the ECU 28 determines whether or not the vehicle speed V is less than a threshold value THv1 (hereinafter also referred to as “first vehicle speed threshold value THv1” or “vehicle speed threshold value THv1”). The threshold value THv1 is a threshold value for determining the relationship between the motor torque limit value Tmot_lim and the auxiliary machine power compensation torque Tmot_min, and details will be described later with reference to FIG. When the vehicle speed V is less than the threshold value THv1 (S24: YES), the process proceeds to step S25. Steps S25 to S29 are the same as steps S14 to S18 of FIG. 3, and are processing for limiting the target motor torque Tmot_tar within a region R1 of FIG. 8 to be described later.

  Returning to step S24 in FIG. 5, if the vehicle speed V is not less than the threshold value THv1 (S24: NO), the process proceeds to step S30 in FIG. Steps S30 to S34 are processes for limiting the target motor torque Tmot_tar within a region R2 of FIG.

  In step S30 in FIG. 6, the ECU 28 determines whether or not the difference ΔT between the target vehicle deceleration torque Tv_tar and the engine torque Teng is equal to or greater than the motor torque limit value Tmot_lim, as in step S25 in FIG.

  If the difference ΔT is greater than or equal to the limit value Tmot_lim (S30: YES), whether or not the difference ΔT (= Tv_tar−Teng) between the target vehicle deceleration torque Tv_tar and the engine torque Teng is equal to or less than the auxiliary power compensation torque Tmot_min in step S31 (In other words, whether or not the difference between the absolute value of the target vehicle deceleration torque Tv_tar and the absolute value of the engine torque Teng | Tv_tar | − | Teng | is greater than or equal to the absolute value | Tmot_min | of the auxiliary machine power compensation torque Tmot_min). judge.

  When the difference ΔT (= Tv_tar−Teng) is equal to or less than the compensation torque Tmot_min (S31: YES), the compensation torque Tmot_min is secured at the target motor torque Tmot_tar. Therefore, in step S32, the ECU 28 sets the difference ΔT as the target motor torque Tmot_tar (Tmot_tar ← ΔT). When the difference ΔT is not equal to or less than the compensation torque Tmot_min (S31: NO), in order to ensure the auxiliary machine power compensation torque Tmot_min, in step S33, the ECU 28 sets the auxiliary machine electric power compensation torque Tmot_min as the target motor torque Tmot_tar (Tmot_tar ← Tmot_min).

  Returning to step S30, if the difference ΔT is not equal to or greater than the motor torque limit value Tmot_lim (S30: NO), in step S34, the ECU 28 sets the motor torque limit value Tmot_lim as the target motor torque Tmot_tar, similarly to steps S18 and S29. (Tmot_tar ← Tmot_lim).

  The example of FIG. 7 will be described assuming that the vehicle speed V is not less than the threshold value THv1 (S24: NO). As in the example of FIG. 4, in the example of FIG. 7, the engine torque Teng has not reached the target vehicle deceleration torque Tv_tar in the case of “no shift” or “1-stage deceleration”. Further, the auxiliary machine power compensation torque Tmot_min can be included in the target motor torque Tmot_tar (S31: YES). Therefore, the ECU 28 generates the motor torque Tmot according to the difference ΔT (S32).

  On the other hand, as in the example of FIG. 4, in the case of “two-stage deceleration” in FIG. 7, the engine torque Teng exceeds the target vehicle deceleration torque Tv_tar (the absolute value of the target vehicle deceleration torque Tv_tar and the absolute value of the engine torque Teng). The difference is negative) (S31: NO). Unlike the example of FIG. 4, in the example of FIG. 7, even if the engine torque Teng exceeds the target vehicle deceleration torque Tv_tar, the motor torque Tmot (deceleration torque) is generated for the auxiliary power compensation torque Tmot_min (S33). . Therefore, the difference β between the total value of the engine torque Teng and the target motor torque Tmot_tar and the target vehicle deceleration torque Tv_tar is larger than the difference α in FIG.

(2-3-2. Target vehicle deceleration torque Tv_tar, motor torque limit value Tmot_lim, and auxiliary machine power compensation torque Tmot_min)
Next, the target vehicle deceleration torque Tv_tar, the motor torque limit value Tmot_lim, and the auxiliary machine power compensation torque Tmot_min in the regeneration enhancement control will be described with reference to FIG.

  The target vehicle deceleration torque Tv_tar is set to be substantially constant in the region where the vehicle speed V is equal to or higher than the threshold value THv2 (> THv1). In a region where the vehicle speed V is less than the threshold value THv2, the vehicle speed V is set to increase (decrease as an absolute value) as it approaches 0 km / h. The target vehicle deceleration torque Tv_tar here is the same as that used in the normal deceleration control.

  The motor torque limit value Tmot_lim indicates the maximum value of the deceleration torque generated by the motors 16 and 18. In the RWD deceleration control described in detail later, the target vehicle deceleration torque Tv_tar is substantially equal to the motor torque limit value Tmot_lim. However, in the normal deceleration control and the regeneration enhancement control, the target vehicle is considered in advance by taking into account the engine torque Teng. The motor torque limit value Tmot_lim is made smaller than the deceleration torque Tv_tar. When the vehicle speed V is equal to or higher than the threshold value THv1, the motor torque limit value Tmot_lim is equal to or less than the auxiliary machine power compensation torque Tmot_min.

  Auxiliary machine power compensation torque Tmot_min is the minimum value of the deceleration torque generated by motors 16 and 18 when vehicle speed V is equal to or higher than threshold value THv1. The compensation torque Tmot_min is set as a deceleration torque obtained based on the power consumption (request) of the auxiliary device 29 of the vehicle 10. Alternatively, the compensation torque Tmot_min may be set as a deceleration torque obtained based on the power consumption (actual value or required value) of the front motor 14 (other electric motor).

  In order to maintain the regenerative power of the motors 16 and 18 at a certain value or more, it is necessary to increase the motor torque Tmot correspondingly when the motor rotation speed Nmot decreases. Further, the motor rotation speed Nmot has a correlation with the vehicle speed V. Therefore, the auxiliary power compensation torque Tmot_min in FIG. 8 decreases as the vehicle speed V decreases. In setting the compensation torque Tmot_min (S23 in FIG. 5) and / or the determination in step S24 in FIG. 5, the motor speed Nmot may be used instead of the vehicle speed V.

(2-4. Deceleration control during RWD)
FIG. 9 is a flowchart of the RWD deceleration control (details of S7 in FIG. 2). FIG. 10 is a diagram illustrating an example of a relationship between the target motor torque Tmot_tar and the target vehicle deceleration torque Tv_tar in the RWD deceleration control.

  In step S41 of FIG. 9, the ECU 28 acquires detection values for calculation from various sensors. The calculation detection values here include, for example, the vehicle speed V, the motor rotation speed Nmot, the engine rotation speed Ne, and the motor current Imot.

  In step S42, the ECU 28 calculates the current vehicle deceleration torque Tv. The calculation method is the same as step S12 in FIG. In the RWD deceleration control, the vehicle deceleration torque Tv can be treated as equivalent to the motor torque Tmot (wheel end equivalent).

  In step S43, the ECU 28 sets the target vehicle deceleration torque Tv_tar, similarly to step S13 in FIG.

  In step S44, the ECU 28 determines whether or not the target vehicle deceleration torque Tv_tar and the vehicle deceleration torque Tv are equal. If the target vehicle deceleration torque Tv_tar and the vehicle deceleration torque Tv are equal (S44: YES), in step S45, the ECU 28 maintains the target motor torque Tmot_tar. When the target vehicle deceleration torque Tv_tar and the vehicle deceleration torque Tv are different (S44: NO), the process proceeds to step S46.

  In step S46, the ECU 28 determines whether or not the target vehicle deceleration torque Tv_tar is larger than the vehicle deceleration torque Tv (in other words, whether or not the absolute value of the target vehicle deceleration torque Tv_tar is smaller than the absolute value of the vehicle deceleration torque Tv). Determine.

  When the target vehicle deceleration torque Tv_tar is larger than the vehicle deceleration torque Tv (S46: YES), in step S47, the ECU 28 increases the absolute value of the target motor torque Tmot_tar (in other words, decreases the target motor torque Tmot_tar). When the target vehicle deceleration torque Tv_tar is smaller than the vehicle deceleration torque Tv (S46: NO), in step S48, the ECU 28 decreases the absolute value of the target motor torque Tmot_tar (in other words, increases the target motor torque Tmot_tar).

  As shown in the example of FIG. 10, the target motor torque Tmot_tar is changed according to the target vehicle deceleration torque Tv_tar.

(3. Effects of the present embodiment)
As described above, according to the present embodiment, the target vehicle deceleration torque Tv_tar (target power) corresponding to the input to the accelerator pedal 70 and the brake pedal 72 (target power input unit) by the driver decelerates the vehicle 10. When it is a negative value, it is larger of the difference ΔT (first target regenerative power) between the target vehicle deceleration torque Tv_tar and the engine torque Teng (negative torque) and the auxiliary power compensation torque Tmot_min (second target regenerative power). On the other hand, regenerative strengthening control (regenerative power selection control) with target motor torque Tmot_tar (target regenerative power of the electric motor) is executed (S31 to S33 in FIG. 6). Thus, even when the vehicle deceleration torque Tv (braking force) required by the driver is exceeded, it is possible to generate power consumption of the auxiliary machine 29 and the like. Therefore, regeneration by the motors 16 and 18 can be performed while generating a negative engine torque Teng in the engine 12. Therefore, it is possible to avoid an adverse effect caused by the negative engine torque Teng not being used for deceleration despite the engine 12 being operated.

  Even when the engine 12 is generating the negative engine torque Teng, regeneration by the motors 16 and 18 is continued, and power consumption of the auxiliary machine 29 and the like is generated. For this reason, it becomes easy to ensure the required electric power until the vehicle 10 stops or after the stop, and the convenience of the user can be improved.

  In the present embodiment, the drive ECU 28 sets a motor torque limit value Tmot_lim (upper limit negative power), which is an upper limit value of the negative motor torque Tmot (regenerative torque) generated in the rear wheels 36a, 36b (second drive wheels), to the vehicle speed. It sets based on V (S23 of FIG. 5). The ECU 28 controls the motors 16 and 18 so that the target motor torque Tmot_tar (target regenerative power) does not exceed the motor torque limit value Tmot_lim (S25: NO → S29 in FIG. 5, S30: NO → S34 in FIG. 6). ).

  If the regenerative power generated by the motors 16 and 18 is held at a certain value or more, the torque Tmot of the motors 16 and 18 becomes excessive at a low vehicle speed (low rotational speed Nmot) (see compensation torque Tmot_min in FIG. 8), and negative motor torque. There is a possibility that Tmot may increase and give the user a sense of incongruity. According to the present embodiment, the target motor torque Tmot_tar of the motors 16 and 18 is controlled so as not to exceed the motor torque limit value Tmot_lim corresponding to the vehicle speed V (S25: NO → S29). For this reason, it becomes possible to avoid a user's uncomfortable feeling accompanying an increase in motor torque Tmot (regenerative torque) at low vehicle speeds.

  In the present embodiment, the ECU 28 is an FWD or AWD (first drive wheel drive) that drives only the front wheels 32a, 32b (first drive wheels) or both the front wheels 32a, 32b and the rear wheels 36a, 36b (second drive wheels). State) and RWD (second drive wheel single drive state) that drives only the rear wheels 36a and 36b can be switched. Further, when the vehicle speed V is equal, the ECU 28 increases the deceleration torque (FIG. 7) of the FWD or AWD (during two-stage deceleration) than the deceleration torque of the RWD (FIG. 10).

  As a result, it is possible to easily secure the motor torque Tmot (regenerative power) for FWD or AWD (even if the regenerative torque is somewhat larger), and to easily set the motor torque Tmot for RWD. It becomes.

  In the present embodiment, the vehicle 10 includes a battery 20 (power storage device) that supplies electric power to the motors 16 and 18 and charges regenerative electric power of the motors 16 and 18. Further, the ECU 28 sets a threshold value THsoc (charge amount threshold value) of the battery SOC for determining whether or not to execute the regeneration enhancement control (regenerative power selection control). When the SOC falls below the threshold value THsoc (S4: NO in FIG. 2), regeneration enhancement control is executed (S6). When the SOC exceeds the threshold value THsoc (S4: YES), regeneration reduction is enhanced by performing normal deceleration control. Control is prohibited (S5).

  Thus, regeneration enhancement control is performed only when battery SOC is lower than threshold value THsoc, that is, when there is a high possibility that battery 20 needs to be charged. For this reason, when the regeneration enhancement control is prohibited, it is difficult for the user to feel uncomfortable with the deceleration torque (deceleration) of the vehicle 10 accompanying the generation or increase of the motor torque Tmot (regenerative power) for regeneration. Is possible.

  In the present embodiment, the ECU 28 starts the regeneration enhancement control (regenerative power selection control) that the accelerator opening degree θap (the operation amount of the accelerator pedal 70) and the brake opening degree θbp (the operation amount of the brake pedal 72) are zero. One of the conditions or execution conditions (S2 in FIG. 2).

  As a result, the regeneration enhancement control is performed in the deceleration control when the accelerator pedal 70 and the brake pedal 72 are not operated by the driver. For this reason, it is possible to flexibly control the deceleration in a state where both the pedals 70 and 72 are not operated.

II. Modifications It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted based on the description of the present specification. For example, the following configuration can be adopted.

[1. Vehicle 10 (application target)]
In the above embodiment, the vehicle 10 that is an automobile is described (FIG. 1). However, for example, from the viewpoint of securing the auxiliary power compensation torque Tmot_min in the regeneration enhancement control, the present invention is applied to a vehicle having the engine 12 and at least one of the motors 16 and 18 even if it is other than an automobile. Applicable. For example, the vehicle 10 can be either an automatic tricycle or an automatic six-wheeled vehicle.

  In the above embodiment, the vehicle 10 has one engine 12 and three traveling motors 14, 16, and 18 as drive sources, but the drive sources are not limited to this combination. For example, the vehicle 10 may have one or more traveling motors for the front wheels 32 and one or more traveling motors for the rear wheels 36 as drive sources. For example, only one traveling motor can be used for the front wheel 32 or the rear wheel 36. In this case, the driving force may be distributed to the left and right wheels using a differential device. Moreover, the structure which allocates an individual driving motor (a so-called in-wheel motor is included) to each of all the wheels is also possible.

  FIG. 11 is a schematic configuration diagram of a drive system of a vehicle 10A and its surroundings according to a modified example of the present invention. In the vehicle 10A, the configurations of the front wheel drive device 34 and the rear wheel drive device 38 of the vehicle 10 according to the embodiment are reversed. That is, the front wheel drive device 34a of the vehicle 10A includes second and third travel motors 16a and 18a disposed on the front side of the vehicle 10A. Further, the rear wheel drive device 38a of the vehicle 10A includes an engine 12a and a first travel motor 14a arranged in series on the rear side of the vehicle 10A.

[2. First to third travel motors 14, 16, 18]
In the said embodiment, although the 1st-3rd traveling motors 14, 16, and 18 were made into the three-phase alternating current brushless type, it is not restricted to this. For example, the first to third travel motors 14, 16, and 18 may be a three-phase AC brush type, a single-phase AC type, or a DC type.

[3. Battery 20 (Power Source)]
In the above embodiment, the battery 20 and the first motor 14 (when power is generated by the driving force from the engine 12) are used as power sources for the second and third travel motors 16 and 18. However, for example, from the viewpoint of supplying power to the motors 16 and 18, the present invention is not limited to this. For example, a configuration in which power generation by the first motor 14 is not performed is possible. Alternatively, other power sources such as a capacitor and a fuel cell can be used in addition to or instead of the battery 20.

[4. Accelerator pedal 70, brake pedal 72, and shift lever 74 (target power input unit)]
In the above-described embodiment, the accelerator pedal 70, the brake pedal 72, and the shift are used as a target power input unit for inputting from the driver for setting the target vehicle deceleration torque Tv_tar (target power) generated by the engine 12 and the motors 16 and 18. A lever 74 was used. However, it is not limited to this from the viewpoint of input from the driver for setting the target vehicle deceleration torque Tv_tar (target power). For example, it is possible to use only one or two of the accelerator pedal 70, the brake pedal 72, and the shift lever 74.

[5. Control by drive ECU 28]
(5-1. Switching of driving state)
In the above embodiment, the ECU 28 can switch FWD, RWD, and AWD as the driving state of the vehicle 10. However, for example, from the viewpoint of securing the auxiliary machine power compensation torque Tmot_min in the regeneration enhancement control, the driving state in which the engine 12 is driven and the driving state in which the motor 14, 16, or 18 is driven are included. For example, it is not limited to this. For example, the present invention can be applied to a configuration in which only FWD and RWD are possible.

(5-2. Deceleration control)
(5-2-1. Control parameters)
In the above embodiment, torque is used as a control parameter for controlling deceleration or target power when the vehicle 10 is decelerated, but this is not a limitation from the viewpoint of controlling deceleration. For example, a driving force or output correlated with torque may be used.

  In the above embodiment, the motor torque limit value Tmot_lim is set in the normal deceleration control during engine running and the regeneration enhancement control (S13 in FIG. 3 and S23 in FIG. 5). However, from the viewpoint of bringing the vehicle deceleration torque Tv closer to the target vehicle deceleration torque Tv_tar, it is possible not to use the motor torque limit value Tmot_lim. In this case, for example, the target motor torque Tmot_tar can be set based on the difference ΔT between the target vehicle deceleration torque Tv_tar and the engine torque Teng.

(5-2-2. Auxiliary machine power compensation torque Tmot_min)
In the above embodiment, the motor torque Tmot is allowed to be generated in the state where the total value of the engine torque Teng and the motor torque Tmot exceeds the target vehicle deceleration torque Tv_tar only during the regeneration enhancement control (FIG. 4). FIG. 7 and FIG. 10). However, for example, from the viewpoint of promoting charging when the battery SOC is low, the motor torque Tmot may be allowed to exceed the target vehicle deceleration torque Tv_tar even in the RWD deceleration control. In other words, in the RWD deceleration control, the target vehicle deceleration torque Tv_tar may be increased when the SOC is equal to or greater than the threshold value THsoc.

(5-2-3. Others)
In the above-described embodiment, the condition for adjusting the vehicle deceleration torque Tv (deceleration torque adjustment condition) includes that the accelerator opening θap and the brake opening θbp are zero (S2 in FIG. 2). However, for example, from the viewpoint of applying the present invention to a scene where deceleration torque is generated in the vehicle 10, the accelerator opening θap and the brake opening θbp as the deceleration torque adjustment conditions are non-zero threshold values (opening threshold values). There may be. Further, instead of the accelerator opening θap and the brake opening θbp, changes in the accelerator opening θap and the brake opening θbp per unit time may be used.

10, 10A ... vehicle 12 ... engine (internal combustion engine)
16, 16a, 18, 18a ... motor (electric motor)
20 ... High-voltage battery (power storage device) 28 ... Drive ECU (drive control device)
29 ... Auxiliary machine (electrically operated auxiliary machine) 32a, 32b ... Front wheel 36a, 36b ... Rear wheel 70 ... Accelerator pedal (target power input unit)
72 ... Brake pedal (target power input section)
74 ... Shift lever (target power input section)
Teng ... engine torque THsoc ... SOC threshold (remaining capacity threshold)
Tmot_lim: Motor torque limit value (upper limit negative power)
Tmot_tar: Target motor torque (target regenerative power)
Tv_tar: Target vehicle deceleration torque (target power)
V: Vehicle speed θap: Accelerator opening (amount of accelerator pedal operation)
θbp ... Brake opening (amount of brake pedal operation)
ΔT: Difference between target vehicle deceleration torque and engine torque

Claims (5)

An internal combustion engine mechanically connected to the first drive wheel which is either the front wheel or the rear wheel;
An electric motor mechanically connected to a second drive wheel which is the other of the front wheel and the rear wheel;
A drive control device for controlling the internal combustion engine and the electric motor;
A target power input unit that inputs from a driver for setting target power generated by the internal combustion engine and the electric motor,
The drive control device sets the target power generated by the internal combustion engine and the electric motor based on an input to the target power input unit,
When the target power corresponding to the input to the target power input unit is negative power that decelerates the vehicle and the vehicle speed is equal to or higher than a predetermined vehicle speed , the drive control device The first target regenerative power that is the target regenerative power of the electric motor corresponding to the difference from the negative power generated by the internal combustion engine, and the power consumption of the electric operating auxiliary machine of the vehicle or another electric motor different from the electric motor A vehicle that performs regenerative power selection control in which a larger one of the second target regenerative powers that are the target regenerative power of the electric motor obtained based on the target regenerative power of the electric motor is executed.
The vehicle according to claim 1,
The drive control device includes:
An upper limit negative power that is an upper limit value of the negative power generated in the second drive wheel is set based on the vehicle speed,
The electric motor is controlled so that the target regenerative power does not exceed the upper limit negative power. The vehicle according to claim 1 or 2,
The drive control device includes: a first driving wheel driving state that drives only the first driving wheel or both the first driving wheel and the second driving wheel; and a second driving wheel that drives only the second driving wheel. It is possible to switch between the single drive state,
When the vehicle speeds are equal, the drive control device causes the deceleration in the first drive wheel drive state to be greater than the deceleration in the second drive wheel single drive state. The vehicle according to any one of claims 1 to 3,
The vehicle includes a power storage device that supplies electric power to the electric motor and charges regenerative electric power of the electric motor,
The drive control device includes:
Setting a charge amount threshold value that is a threshold value of the charge amount of the power storage device for determining whether or not to execute the regenerative power selection control;
When the charge amount falls below the charge amount threshold, the regenerative power selection control is executed,
The regenerative power selection control is prohibited when the charge amount exceeds the charge amount threshold value. In the vehicle according to any one of claims 1 to 4,
The target power input unit includes an accelerator pedal and a brake pedal,
The drive control device is characterized in that one of the start condition or execution condition of the regenerative power selection control is that the operation amount of the accelerator pedal and the brake pedal is zero.

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