Vehicle driving force control device

Abstract

To improve a deviation between an actual torque and a target torque while suppressing a response lag of a torque change to an accelerator operation by a driver.SOLUTION: A drive force control device of a vehicle includes a motor 5, an engine 4 and a controller 20. The controller distributes a target engine torque from a target torque of a vehicle according to a prescribed distribution rule and outputs a control signal corresponding to the target engine torque to the engine. The controller predicts an intake air quantity to a cylinder in the future later than the present time on the basis of the target engine torque, and predicts the torque of the engine in the future on the basis of the predicted intake air quantity. The controller sets the target motor torque so that the target torque of the vehicle is achieved in the future on the basis of the predicted torque of the engine and outputs the control signal corresponding to the target motor torque to the motor.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The technology disclosed herein relates to a driving force control device for a vehicle. [Background technology]

[0002] Patent Document 1 discloses a hybrid vehicle equipped with an engine and a motor. The engine and motor share the required torque output in response to the driver's accelerator operation. When requesting an increase in torque from both the engine and the motor, the controller of this hybrid vehicle delays the torque request to the motor by a predetermined time that simulates a response delay of the engine. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-67737 Summary of the Invention [Problem to be solved by the invention]

[0004] A hybrid vehicle equipped with an engine and a motor distributes the target torque of the vehicle to the engine and the motor so as to optimize energy efficiency. The torque distribution to the engine and the motor changes continuously depending on various engine conditions, such as the battery condition (e.g., SOC (State of Charge) and / or temperature) and / or engine water temperature.

[0005] Generally, the torque response of an engine is slower than the torque response of a motor. Therefore, during a transient period when the target torque changes, the change in engine torque may be delayed relative to the change in motor torque. The delay in engine torque change may cause torque fluctuations in the vehicle. Furthermore, the delay in engine torque change may cause a deviation between the total torque actually generated by the engine and motor and the target torque.

[0006] In conventional hybrid vehicles, the timing of the motor torque increase is delayed to coincide with the timing of the engine torque increase. In conventional hybrid vehicles, torque fluctuations are less likely to occur because the engine torque increase and the motor torque increase are synchronized.

[0007] However, in conventional hybrid vehicles, the timing of the motor torque increase is delayed, which means that the increase in vehicle torque in response to the driver's accelerator operation is delayed. Conventional hybrid vehicles have poor drivability. Unfortunately, conventional hybrid vehicles only synchronize the increase in engine torque with the increase in motor torque, which makes it impossible to reduce the discrepancy between the actual torque and the target torque.

[0008] The technology disclosed herein reduces the difference between the actual torque and the target torque while suppressing the response delay of the torque change in response to the accelerator operation by the driver. [Means for solving the problem]

[0009] In a hybrid vehicle equipped with an engine and a motor, it is conceivable to achieve both suppression of response delay and improvement of torque deviation by having the motor compensate for engine response delay. That is, when changing the target engine torque in response to the driver's accelerator operation, the controller calculates the difference between the actual engine torque and the target engine torque and corrects the target motor torque so that the engine torque difference is compensated for by the motor torque. A highly responsive motor can compensate for the engine torque difference caused by engine response delay. Compensation by the motor can suppress torque response delay to accelerator operation and also improve the deviation between the actual torque and the target torque.

[0010] However, it takes time to detect engine torque, calculate the torque difference, and / or set the motor torque correction amount. In the control process described above, the actual engine torque changes from moment to moment, even during the period from when the engine torque is detected to when the motor correction amount is set. The correction of the motor torque follows the change in the actual engine torque. The deviation between the actual torque and the target torque does not disappear.

[0011] The inventors of the present application came up with a technical idea of ​​predicting engine torque in the future by looking ahead to changes in engine torque, and setting a target motor torque in the future based on the predicted engine torque. The inventors of the present application proceeded to develop a control system that realizes this technical idea, and have now completed the technology disclosed herein.

[0012] Specifically, the technology disclosed herein relates to a vehicle driving force control device. a motor supplied with power to generate torque for vehicle travel; an engine that burns fuel in cylinders to generate torque for running the vehicle; a controller that receives an accelerator operation signal and outputs a control signal corresponding to the accelerator operation to the motor and the engine; the controller sets a target torque of the vehicle corresponding to the accelerator operation, distributes a target engine torque from the target torque of the vehicle in accordance with a predetermined distribution rule, and outputs a control signal corresponding to the target engine torque to the engine; the controller predicts an intake air amount into the cylinder in the future from the present time based on the target engine torque, and predicts a torque of the engine in the future based on the predicted intake air amount; The controller sets a target motor torque based on the predicted torque of the engine so that a target torque of the vehicle will be achieved in the future, and outputs a control signal corresponding to the target motor torque to the motor.

[0013] A vehicle with this configuration is a so-called hybrid vehicle, equipped with a motor and an engine. The controller distributes the vehicle's target torque into a target engine torque and a target motor torque so that the vehicle's target torque corresponding to accelerator operation is achieved. The engine outputs the target engine torque, and the motor outputs the target motor torque. The engine and motor realize the vehicle's target torque.

[0014] The controller distributes the target engine torque according to a predetermined distribution rule. The distribution rule is, for example, a rule based on the SOC of the battery. The battery is mounted on the vehicle to supply power to the motor. When the SOC is high, the controller may set the target engine torque small and the target motor torque large to prioritize battery discharge, and when the SOC is low, the controller may set the target engine torque large and the target motor torque small to prioritize battery charging. The controller outputs a control signal corresponding to the target engine torque to the engine. The engine is operated to output the target engine torque.

[0015] When the driver operates the accelerator, the controller changes the vehicle's target torque to correspond to the change in accelerator operation. As the vehicle's target torque changes, the controller changes the target engine torque. When the target engine torque changes, the engine changes, for example, the throttle valve opening, which changes the amount of intake air into the cylinders. When the amount of intake air into the cylinders changes, the engine torque changes. There is a time lag between the change in target torque, the change in throttle valve opening and the change in intake air amount, and the actual change in engine torque.

[0016] Changes in throttle valve opening in response to changes in target engine torque can be predicted, for example, by specifying the characteristics (including, for example, mechanical characteristics) of the throttle valve in advance. If changes in throttle valve opening in the future can be predicted, the future intake air amount can be predicted, and if the intake air amount can be predicted, the future engine torque can be predicted. The controller predicts future engine torque based on the target engine torque.

[0017] The controller also predicts future engine torque and sets a target motor torque so that the vehicle's target torque will be achieved in the future. If the predicted engine torque is lower than the target engine torque, the target motor torque is set to a large value to compensate for the shortfall in engine torque. If the predicted engine torque exceeds the target engine torque, the target motor torque is set to a small value to take into account the surplus engine torque. The set target motor torque compensates for the delay in the engine's torque response.

[0018] The controller outputs a control signal to the motor corresponding to the target motor torque. Since the torque response of the motor is generally fast, the motor can output a torque corresponding to the target motor torque in the future, thereby achieving the target torque of the vehicle.

[0019] Since the highly responsive motor compensates for the response delay of the engine, the driving force control device reduces the response delay of torque changes in response to accelerator operation.

[0020] Furthermore, the target motor torque is set based on the predicted future engine torque, rather than the actual engine torque. The set target motor torque does not follow changes in the actual engine torque. The driving force control device can eliminate or substantially eliminate the difference between the actual torque and the target torque.

[0021] As a result, the vehicle driving force control device improves drivability for the driver.

[0022] The controller may set the target motor torque so as to compensate for a difference between the predicted engine torque and the target engine torque.

[0023] The motor can compensate for the engine's delayed response.

[0024] The controller predicts the torque of the engine in the future based on the predicted intake air amount and the optimum ignition timing determined from the operating state of the engine. do.

[0025] Here, the optimal ignition timing may be, for example, MBT (Minimum Advance for the Best Torque). If the controller sets the target engine torque based on the MBT, the engine will operate at its most efficient. The motor can assist the engine, which is operating at its most efficient.

[0026] Also, for example, if the engine's catalytic converter is inactive and the engine is operating in AWS (Accelerated Warm-up System) mode, the optimal ignition timing is retarded from MBT. The optimal ignition timing is not necessarily MBT. In this case, the engine can achieve early activation of the catalytic converter. While the early activation of the catalytic converter is achieved, the motor can assist the engine.

[0027] the controller sets the target motor torque to be equal to or greater than the minimum torque that the motor can generate; When the target motor torque is limited by the minimum torque, the controller retards the ignition timing of the engine from the optimal ignition timing so that the torque of the engine decreases. do.

[0028] The minimum torque that a motor can generate is generally determined according to the temperature condition. Furthermore, if the battery's SOC is high, the motor cannot perform regenerative operation, so the minimum torque of the motor decreases. The minimum torque that can be generated is also determined by the motor's performance. The controller must set the target motor torque to be equal to or greater than the minimum torque that the motor can generate. If the target motor torque is limited by the minimum torque, the set target motor torque is relatively large. There is a risk that the combined torque of the motor torque and engine torque, i.e., the actual torque of the vehicle, will exceed the target torque.

[0029] When the target motor torque is limited by the minimum torque, the controller retards the engine ignition timing from the optimal ignition timing, which reduces the engine torque and prevents the vehicle torque from exceeding the target torque.

[0030] The controller predicting a change in the opening of a throttle valve of the engine after an accelerator pedal operation based on the target engine torque; predicting an amount of air passing through the throttle valve from the predicted opening of the throttle valve and a pressure in an intake manifold of the engine; predicting an amount of air in the intake manifold from the predicted amount of air passing through the throttle valve; The amount of intake air to the cylinder may be predicted from the predicted amount of air in the intake manifold.

[0031] The change in throttle valve opening after accelerator operation can be predicted, for example, by specifying the mechanical characteristics of the throttle valve in advance. If the throttle opening in the future can be predicted, the amount of air passing through the throttle valve in the future can be predicted from the intake manifold pressure downstream of the throttle valve and the intake pressure upstream of the throttle valve, for example, using Bernoulli's equation. Note that the intake manifold pressure may be calculated by converting the amount of air in the intake manifold, which will be described later, into pressure. Alternatively, for example, a pressure sensor may measure the intake pressure upstream of the throttle valve.

[0032] If the amount of air passing through the throttle valve can be predicted, the amount of air in the intake manifold can be predicted, and if the amount of air in the intake manifold can be predicted, the amount of air that will be drawn into the cylinder can be predicted. The controller can predict the amount of air that will be drawn into the cylinder in the future, rather than at the present time.

[0033] The controller predicting a change in the opening and closing timing of an intake valve of the engine after an accelerator pedal operation based on the target engine torque; predicting a charging efficiency from the predicted intake valve opening and closing timing; The amount of intake air into the cylinder may be predicted from the predicted charging efficiency and the predicted amount of air in the intake manifold.

[0034] The change in intake valve timing after accelerator operation can be predicted by specifying in advance the characteristics (including, for example, mechanical characteristics) of the valve train that changes the intake valve timing. Also, by specifying in advance the relationship between the intake valve timing, engine operating state, and charging efficiency for the engine, the controller can predict the charging efficiency based on the predicted intake valve timing.

[0035] If the charging efficiency can be predicted, the amount of intake air into the cylinder can be predicted with higher accuracy from the amount of air in the intake manifold and the charging efficiency. The controller can predict the amount of intake air into the cylinder in the future with higher accuracy than the present. [Effects of the Invention]

[0036] The above-described vehicle driving force control device can reduce the difference between the actual torque and the target torque while suppressing the response delay of the torque change in response to the accelerator operation by the driver. [Brief explanation of the drawings]

[0037] [Figure 1] FIG. 1 shows a hybrid vehicle. [Figure 2] FIG. 2 is a block diagram of the driving force control device. [Figure 3] FIG. 3 shows a map relating to the modes of a hybrid vehicle. [Figure 4] Figure 4 shows the functional blocks of the controller. [Figure 5] FIG. 5 shows the functional blocks of the torque distribution unit. [Figure 6] FIG. 6 shows the functional blocks of the engine control unit. [Figure 7] FIG. 7 shows the relationship between engine speed and delay time. [Figure 8] FIG. 8 shows a time chart of the driving force control. [Figure 9] FIG. 9 shows a modified example of the torque distribution section. [Figure 10] FIG. 10 is a flowchart relating to the control of the driving force control device. DETAILED DESCRIPTION OF THE INVENTION

[0038] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a vehicle driving force control device will be described with reference to the drawings. The driving force control device described here is an example.

[0039] (Hybrid vehicle) Fig. 1 shows an automobile 1 (an example of a vehicle) to which the disclosed technology is applied. The automobile 1 is a hybrid automobile that can run on electric power. The automobile 1 has a total of four wheels: front wheels 2F and rear wheels 2R.

[0040] The automobile 1 is equipped with an engine 4 and a motor 5 as drive sources. These work together to drive the rear wheels 2R, thereby propelling the automobile 1. The automobile 1 is a rear-wheel drive vehicle. The motor 5 is used not only as a drive source but also as a generator during regeneration.

[0041] The automobile 1 is equipped with a high-voltage battery 9. The motor 5 generates torque for driving the automobile 1 by using power supplied from the high-voltage battery 9. An external power source 31 is connected to the high-voltage battery 9 via a power feed port 3. The high-voltage battery 9 is charged by the external power source 31. The automobile 1 is a so-called plug-in hybrid vehicle. Note that the automobile 1 may also be a hybrid vehicle in which the power feed port 3 is omitted.

[0042] In the case of this automobile 1, the engine 4 is disposed at the front of the body, and the drive wheels are disposed at the rear of the body, that is, this automobile 1 is a so-called FR vehicle.

[0043] The automobile 1 is equipped with an engine 4, a motor 5, and drive system devices such as a K0 clutch 6, an inverter 7, and an automatic transmission 8. The automobile 1 is also equipped with a controller 20 as a control system device.

[0044] (Drive system device) The engine 4 is, for example, an internal combustion engine that burns fossil fuels. The engine 4 is also a so-called four-stroke engine that generates rotational power by repeating cycles of intake, compression, expansion, and exhaust.

[0045] The engine 4 is a spark ignition engine. However, the engine 4 may be a compression ignition engine. The engine 4 has a plurality of cylinders. However, the number of cylinders of the engine 4 is not limited to a specific number.

[0046] In this automobile 1, the engine 4 is disposed in approximately the center in the vehicle width direction, with the crankshaft 4a that outputs rotational power facing the front-to-rear direction of the vehicle body. The automobile 1 is equipped with various devices and mechanisms associated with the engine 4, such as an intake system, an exhaust system, a fuel supply system, and an ignition system. The engine 4 will be described later.

[0047] The motor 5 is a permanent magnet synchronous motor driven by three-phase AC. The motor 5 is arranged in series behind the engine 4 via a K0 clutch 6. The motor 5 is also arranged in series in front of the automatic transmission 8.

[0048] The K0 clutch 6 is disposed between the front end of the shaft 5a of the motor 5 and the crankshaft 4a of the engine 4. The K0 clutch 6 switches between a state in which the crankshaft 4a and the shaft 5a are connected (connected state) and a state in which the crankshaft 4a and the shaft 5a are separated (separated state).

[0049] A rear end of the shaft 5a of the motor 5 is connected to an input shaft 8a of the automatic transmission 8. Therefore, the engine 4 is connected to the automatic transmission 8 via the K0 clutch 6 and the shaft 5a. The engine 4 is separated from the automatic transmission 8 by disengaging the K0 clutch 6.

[0050] The K0 clutch 6 is switched between an engaged state and a disengaged state while the automobile 1 is traveling. For example, when the automobile 1 is decelerating, the K0 clutch 6 may be disengaged and regeneration may be performed with the engine 4 disconnected.

[0051] The motor 5 is connected to a high-voltage battery 9 mounted on the vehicle as a drive power source via an inverter 7 and a high-voltage cable 40. A contactor 90 is provided in the high-voltage cable 40.

[0052] The high-voltage battery 9 supplies high-voltage DC power to the inverter 7. The inverter 7 converts the DC power into three-phase AC and supplies it to the motor 5, thereby driving the motor 5 to rotate. The motor 5 also supplies regenerative energy to the high-voltage battery 9.

[0053] The high-voltage battery 9 is also connected to a DC-DC converter 10 via a high-voltage cable 40. The DC-DC converter 10 converts high-voltage DC power into low-voltage DC power of 12 V and outputs it. The DC-DC converter 10 (its output side) is connected to a low-voltage battery 11 (a so-called lead-acid battery) via a low-voltage cable 45.

[0054] The low-voltage battery 11 is connected to various electrical components via a low-voltage cable 45. The DC-DC converter 10 is also connected to a CAN 12 (Controller Area Network) via the low-voltage cable 45. As a result, the DC-DC converter 10 supplies low-voltage DC power to the CAN 12.

[0055] The automatic transmission 8 is a multi-stage automatic transmission (so-called AT). The automatic transmission 8 has an input shaft 8a at its front end, which is connected to the shaft 5a of the motor 5 as described above. The automatic transmission 8 has an output shaft 8b at its rear end, which rotates independently from the input shaft 8a.

[0056] A transmission mechanism consisting of multiple planetary gear mechanisms and multiple frictional engagement elements is installed between the input shaft 8a and the output shaft 8b. Each frictional engagement element is switched between an engaged state and a disengaged state by hydraulic pressure. The automatic transmission 8 selectively engages the multiple frictional engagement elements by hydraulic control. The automatic transmission 8 switches between forward gears (1st to 8th gears) and a reverse gear (reverse gear).

[0057] If the element that should be engaged in each gear is not engaged, the input shaft 8a and the output shaft 8b are disconnected (so-called neutral). Even if rotational power is input to the automatic transmission 8 from the drive source, the rotational power is not output from the automatic transmission 8.

[0058] As shown in Fig. 1, the output shaft 8b of the automatic transmission 8 is connected to a differential gear 16 via a propeller shaft 15 extending in the longitudinal direction of the vehicle body. A pair of drive shafts 17, 17 extending in the vehicle width direction and connected to the left and right rear wheels 2R, 2R are connected to the differential gear 16. The rotational power output through the propeller shaft 15 is distributed by the differential gear 16 and then transmitted to each rear wheel 2R via the pair of drive shafts 17, 17.

[0059] (engine) As shown in FIG. 2, the engine 4 has an ignition plug 41, an injector 42, a throttle valve 43, and an intake S-VT (Sequential-Valve Timing) 44.

[0060] The spark plug 41 is attached to the engine 4. Upon receiving a control signal from the controller 20, the spark plug 41 forcibly ignites the air-fuel mixture in the cylinder.

[0061] The injector 42 is attached to the engine 4. The injector 42 injects fuel, for example, into a cylinder in response to a control signal from the controller 20. The fuel and air drawn into the cylinder form an air-fuel mixture.

[0062] The throttle valve 43 is a butterfly valve attached to the intake passage of the engine 4. The throttle valve 43 changes its opening in response to a control signal from the controller 20. When the opening of the throttle valve 43 changes, the amount of air taken into the cylinder changes. When the opening of the throttle valve 43 increases, the amount of intake air increases. When the opening of the throttle valve 43 decreases, the amount of intake air decreases.

[0063] The intake S-VT 44 changes the opening and closing timing of the intake valve, for example, continuously. The intake S-VT 44 is hydraulically driven or electrically driven. The intake S-VT 44 changes the opening and closing timing of the intake valve in the advance or retard direction in response to a control signal from the controller 20. When the intake S-VT 44 changes the opening and closing timing of the intake valve, the charging efficiency changes. The amount of intake air into the cylinder changes as a result of a combination of changes in the opening degree of the throttle valve 43 and changes in the opening and closing timing of the intake valve.

[0064] (driving force control device) FIG. 2 is a block diagram of a driving force control device. The vehicle 1 is equipped with the above-mentioned controller 20 to control the engine 4, motor 5, K0 clutch 6, automatic transmission 8, etc. in response to driver operation and thereby control the running of the vehicle 1. The controller 20 is composed of hardware such as a processor, memory, and interface, and software such as a database and control programs. Note that while the driving force control device in FIG. 2 shows one controller 20, the controller of the driving force control device may be divided into a unit (PCM) that primarily controls the operation of the driving source (engine 4 and motor 5) and a unit (TCM) that primarily controls the operation of the K0 clutch 6 and automatic transmission 8. The PCM and TCM are connected by a CAN 12 and are configured to be able to communicate electrically with each other.

[0065] The driving force control device is equipped with sensors that measure various parameters related to vehicle driving. Specifically, the driving force control device is equipped with an accelerator position sensor 51, an intake pressure sensor 52, a water temperature sensor 53, an engine rotation speed sensor 54, a motor rotation speed sensor 55, a vehicle speed sensor 56, and an SOC sensor 57.

[0066] Accelerator position sensor 51 outputs a signal corresponding to the operation of accelerator pedal 19 (see FIG. 1) operated by the driver.

[0067] The intake pressure sensor 52 outputs a signal corresponding to the pressure in the intake passage of the engine 4 at a portion upstream of the throttle valve 43. The water temperature sensor 53 outputs a signal corresponding to the temperature of the cooling water for the engine 4.

[0068] The engine rotation speed sensor 54 outputs a signal corresponding to the rotation speed of the engine 4. The motor rotation speed sensor 55 outputs a signal corresponding to the rotation speed of the motor 5. In the automobile 1, when the K0 clutch 6 is in an engaged state and the engine 4 and the motor 5 each output torque, the rotation speed of the engine 4 and the rotation speed of the motor 5 match.

[0069] The vehicle speed sensor 56 outputs a signal corresponding to the vehicle speed of the automobile 1. The SOC sensor 57 outputs a signal corresponding to the SOC of the high-voltage battery 9.

[0070] The controller 20 receives the signals output by these sensors via the CAN 12. The controller 20 outputs control signals to the engine 4, the inverter 7, the K0 clutch 6, and the automatic transmission 8 via the CAN 12. In this way, the controller 20 controls the engine 4, the motor 5, the K0 clutch 6, and the automatic transmission 8.

[0071] (Details of driving force control) FIG. 3 shows a map 91 relating to the modes of the automobile 1. The automobile 1 has an EV mode and an HEV mode. The EV mode is an electric vehicle mode in which only the motor 5 outputs torque for driving the automobile 1. The HEV mode is a hybrid electric vehicle mode in which both the engine 4 and the motor 5 output torque for driving the automobile 1. When the engine water temperature is relatively high and the SOC of the high-voltage battery 9 is relatively high, the automobile 1 is in EV mode. Fuel efficiency is improved by using the power of the high-voltage battery 9. When the engine water temperature is low, the automobile 1 is in HEV mode. The engine coolant, whose temperature has been increased by operating the engine 1, is used to heat the passenger compartment. The energy efficiency of the automobile 1 is improved. When the SOC of the high-voltage battery 9 is relatively low, the automobile 1 is in HEV mode. Operating the engine 1 charges the high-voltage battery 9 while suppressing its power consumption. The SOC of the high-voltage battery 9 is restored.

[0072] The controller 20 stores a map 91. The controller 20 switches between distributing the target torque of the automobile 1 to both the target engine torque and the target motor torque (i.e., HEV mode) and distributing the target torque of the automobile 1 only to the target motor torque (i.e., EV mode) in accordance with the map 91.

[0073] Here, in this automobile 1, the ignition timing of the engine 4 in HEV mode is basically MBT. The engine 4 operates at the most efficient rate. The motor 5 assists the engine 4, which operates at the most efficient rate.

[0074] When the catalytic converter of the engine 4 is inactive and the engine 4 is operating in AWS mode, the ignition timing is retarded from MBT. This increases exhaust losses. In AWS mode, the engine 4 can use the exhaust losses to activate the catalytic converter earlier. The motor 5 assists the engine 4 in activating the catalytic converter.

[0075] Next, torque distribution to the engine 4 and the motor 5 in the HEV mode will be described with reference to Figures 4-7. Figure 4 shows functional blocks of the controller 20. The controller 20 has, as functional blocks, a torque conversion unit 21, a torque mediation unit 22, a torque distribution unit 23, an engine control unit 24, and a motor control unit 25.

[0076] The torque conversion unit 21 receives a signal from the accelerator position sensor 51 and sets a target torque for the automobile 1 based on the accelerator position. More specifically, the torque conversion unit 21 sets a target acceleration for the automobile 1 based on the accelerator operation by the driver, and converts the set target acceleration into a target torque (i.e., the target torque for the automobile 1) based on the vehicle speed of the automobile 1 and the gear position of the automatic transmission 8.

[0077] The torque mediation unit 22 receives the target torque based on the accelerator position set by the torque conversion unit 21, as well as torque request signals other than the accelerator position, to set the final target torque. The torque request signals other than the accelerator position include, for example, torque request signals for stabilizing the behavior of the automobile 1.

[0078] The torque distribution unit 23 receives the final target torque, which is the target torque of the automobile 1 set by the torque mediation unit 22, and distributes the target torque into a target engine torque and a target motor torque. When the automobile 1 is in the EV mode, the target engine torque is zero, and the target motor torque matches the target torque of the automobile 1. The torque distribution unit 23 will be described in detail later.

[0079] The engine control unit 24 outputs a control signal corresponding to the target engine torque set by the torque distribution unit 23 to the engine 4, more specifically, to the spark plug 41, the injector 42, the throttle valve 43, and the intake S-VT 44. The engine 4 operates so as to achieve the target engine torque.

[0080] The motor control unit 25 outputs a control signal corresponding to the target motor torque set by the torque distribution unit 23 to the inverter 7. The motor 5 is controlled via the inverter 7. The motor 5 operates to achieve the target motor torque. The engine 4 outputs torque and the motor 5 outputs torque, thereby achieving the target torque of the automobile 1.

[0081] 5 shows functional blocks of the torque distribution unit 23. The torque distribution unit 23 has, as functional blocks, an SOC management unit 231, a first adder-subtractor 232, an engine torque calculation unit 233, a phase adjustment unit 234, a second adder-subtractor 235, a limiting unit 236, a third adder-subtractor 237, and an adder 238.

[0082] The SOC management unit 231 receives the final target torque of the vehicle 1 set by the torque arbitration unit 22. The SOC management unit 231 also receives information about the high-voltage battery 9. The information about the high-voltage battery 9 includes at least the SOC of the high-voltage battery 9 based on the measurement signal of the SOC sensor 57 and the temperature of the high-voltage battery 9. The SOC management unit 231 provisionally sets the target torque of the motor 5 based on the target torque of the vehicle 1 and the battery information. For example, when the SOC is high, the SOC management unit 231 increases the target motor torque to increase the amount of assistance of the engine 4 by the motor 5. For example, when the SOC is low, the SOC management unit 231 lowers the target motor torque to prioritize charging of the high-voltage battery 9. The target motor torque set here corresponds to the steady-state target motor torque.

[0083] The first adder-subtractor 232 subtracts the target motor torque set by the SOC management unit 231 from the target torque of the automobile 1. The output of the first adder-subtractor 232 is the first target engine torque. The first target engine torque corresponds to the target engine torque for the steady portion. In other words, the first target engine torque is the torque achieved by adjusting the amount of air into the cylinders. The torque distribution unit 23 outputs the first target engine torque to the engine control unit 24.

[0084] When the driver operates the accelerator pedal 19, the target torque of the automobile 1 is changed. When the target torque of the automobile 1 is changed, the target engine torque and the target motor torque are changed. When the target engine torque is changed, the target throttle opening and the target opening / closing timing of the intake valve are changed to change the amount of intake air into the cylinder. It takes time to change the opening of the throttle valve 43 and / or to change the opening / closing timing of the intake valve by the intake S-VT 44, and it also takes time for the amount of intake air in the cylinder to actually change after the opening of the throttle valve 43 and the opening / closing timing of the intake valve are changed. Furthermore, it also takes time for the torque of the engine 4 to actually change after the amount of intake air in the cylinder is actually changed. There is a time lag between when the driver operates the accelerator pedal 19 and when the torque of the engine 4 is changed to the target engine torque.

[0085] The torque distribution unit 23 sets a target motor torque so as to compensate for the slow torque response of the engine 4. More specifically, the torque distribution unit 23 predicts the amount of intake air into the cylinders in the future from the present time, and predicts the future torque of the engine 4 based on the predicted amount of intake air. The torque distribution unit 23 sets a target motor torque based on the predicted torque of the engine 4 so that the target torque of the automobile 1 will be achieved in the future.

[0086] During a transient state in which the target torque changes, the SOC management unit 231 and first adder-subtractor 232 of the torque distributor 23 are involved in setting the target engine torque for the steady state, i.e., the first target engine torque. The engine torque calculation unit 233, phase adjustment unit 234, second adder-subtractor 235, limiting unit 236, third adder-subtractor 237, and adder 238 are involved in setting the target engine torque for the transient state (second target engine torque, which will be described later) and the target motor torque.

[0087] The engine torque calculation unit 233 reads a predicted value of the amount of intake air into the cylinders in the future from the present time. The intake air amount is predicted by the engine control unit 24, as will be described later. The engine control unit 24 outputs a predicted value of the intake air amount a predetermined reference time after the present time. The engine torque calculation unit 233 predicts the torque of the engine 4 in the future from the present time based on the predicted value of the intake air amount. More specifically, the engine torque calculation unit 233 predicts the torque of the engine 4 when the spark plug 41 ignites at the optimal ignition timing determined from the operating state of the engine 4 based on the predicted value of the intake air amount.

[0088] Here, an example of the optimum ignition timing is the MBT described above. That is, the engine torque calculation unit 233 predicts the torque of the engine 4 when the spark plug 41 ignites at the MBT based on the predicted value of the intake air amount. Furthermore, when the engine is operating in the AWS mode, the optimum ignition timing is a timing that is retarded from the MBT. That is, the engine torque calculation unit 233 may predict the torque of the engine 4 when the spark plug 41 ignites at a timing that is retarded from the MBT based on the predicted value of the intake air amount.

[0089] The phase adjustment unit 234 attempts to synchronize the torque change of the engine 4 with the torque change of the motor 5, taking into consideration, for example, a communication delay of the controller 20, a response delay of the motor 5, a response delay of the engine 4, etc. Generally, the torque response of the engine 4 is slower than the torque response of the motor 5. The phase adjustment unit 234 adjusts the phase of the torque prediction value of the engine 4, taking into consideration the difference in torque response between the motor 5 and the engine 4.

[0090] Here, the torque response of engine 4 changes depending on the rotation speed of engine 4. In other words, when the rotation speed of engine 4 is high, the combustion interval (i.e., time interval) for the multiple cylinders of engine 4 is short. When the rotation speed of engine 4 is low, the combustion interval (i.e., time interval) for the multiple cylinders is long. The time from when the amount of intake air into a cylinder changes to when the torque of engine 4 changes changes varies depending on the rotation speed of engine 4. When the rotation speed of engine 4 is high, the time from when the amount of intake air into a cylinder changes to when the torque of engine 4 changes is short. When the rotation speed of engine 4 is low, the time from when the amount of intake air into a cylinder changes to when the torque of engine 4 changes is long.

[0091] The engine control unit 24 predicts the intake air amount after a reference time (i.e., a certain time) from the present time. The time when the intake air amount after the reference time is reflected in the torque of the engine 4 varies depending on the rotation speed of the engine 4.

[0092] FIG. 7 shows the relationship between engine speed and delay time. The delay time corresponds to the delay between a change in the intake air amount and a change in the torque of the engine 4. When the engine speed is low, it takes a long time for a change in the intake air amount to be reflected in a change in the torque of the engine 4. When the engine speed is low, the delay time is long. When the engine speed is high, the delay time is short. In FIG. 7, the relationship between engine speed and delay time is set to a straight line so that the delay time becomes shorter as the engine speed increases. The controller 20 stores the relational expression shown in FIG. 7. Note that the relationship between engine speed and delay time is not limited to the illustrated example. The relationship between engine speed and delay time is not limited to a straight line, but may be a curve. Furthermore, the relationship between engine speed and delay time may be a step-like relationship.

[0093] The phase adjustment unit 234 sets the delay time based on the engine speed. The predicted intake air amount is reflected in the torque of the engine 4 after the delay time. The controller 20 predicts the torque of the engine 4 after a set time from the present time. The set time for torque prediction can be set to any time as long as it is a time after the reference time for predicting the intake air amount.

[0094] When the rotation speed of the engine 4 exceeds the reference rotation speed r0, the delay time is zero. When the rotation speed of the engine 4 is higher than the reference rotation speed r0, the responsiveness of the torque change of the engine 4 to the accelerator operation is sufficiently high, so there is no need to provide a delay time. When the rotation speed of the engine 4 is higher than the reference rotation speed, the controller 20 can accurately predict the torque of the engine 4 even if the delay time is set to zero.

[0095] If the rotation speed of the engine 4 becomes higher than the reference rotation speed, the torque response of the engine 4 becomes equal to the torque response of the motor 5, or the torque response of the motor 5 becomes slower than the torque response of the engine 4. Therefore, when the rotation speed of the engine 4 is high, it is conceivable to speed up the torque response of the motor 5 in order to synchronize the torque response of the engine 4 with the torque response of the motor 5. However, if the rotation speed of the engine 4 becomes high, the time required for one rotation of the engine 4 and the motor 5 becomes short, so the torque response of the engine 4 and the motor 5 will be substantially synchronized even without speeding up the torque response of the motor 5.

[0096] Once the torque of engine 4 after a set time from the present time has been predicted, second adder-subtractor 235 subtracts the torque of engine 4 after the set time from the present time from the target torque of automobile 1. The predicted torque of engine 4 after the set time includes a delay in the torque response of engine 4. If the output of second adder-subtractor 235 is set as the target motor torque after the set time from the present time, the target torque of automobile 1 is achieved by adding the motor torque to the predicted torque of engine 4. In other words, the target motor torque compensates for the delay in the torque response of engine 4.

[0097] The limiting unit 236 outputs a final target motor torque based on the target motor torque output by the second adder-subtractor 235 and the maximum and minimum torques of the motor 5. Here, the maximum motor torque and minimum motor torque are set according to the performance of the motor 5, the temperature of the motor 5, and / or the SOC of the high-voltage battery 9. For example, when the SOC is high, the motor 5 cannot perform regenerative operation, so the minimum motor torque is set to be small. When the SOC is low, the high-voltage battery 9 must be charged, so the maximum motor torque is set to be small. When the target motor torque output by the second adder-subtractor 235 exceeds the maximum motor torque, the limiting unit 236 sets the target motor torque to the maximum motor torque. When the target motor torque output by the second adder-subtractor 235 is lower than the minimum motor torque, the limiting unit 236 sets the target motor torque to the minimum motor torque. If the target motor torque output by the second adder-subtractor 235 is less than the maximum motor torque and greater than or equal to the minimum motor torque, the limiting unit 236 sets the target motor torque output by the second adder-subtractor 235 as the final target motor torque.

[0098] Motor control unit 25 controls motor 5 via inverter 7 based on the target motor torque output by limiting unit 236. As described above, motor 5 outputs torque to complement engine 4 so that the target torque of automobile 1 is achieved a set time from the present time. While suppressing the response delay of torque change in response to the driver's operation of accelerator pedal 19, torque change of engine 4 and torque change of motor 5 are synchronized, suppressing the deviation between the actual torque and the target torque.

[0099] Here, when the target motor torque is limited by the minimum motor torque in limiting unit 236, the target motor torque output by limiting unit 236 is greater than the target motor torque output by second adder-subtractor 235. If motor 5 continues to output the target motor torque (i.e., the minimum motor torque) and engine 4 continues to output the target engine torque, the torque of automobile 1 after a set time from the present time will exceed the target torque.

[0100] The third adder-subtractor 237 calculates the difference between the target motor torque output by the second adder-subtractor 235 and the target motor torque output by the limiting unit 236. If the difference is zero, the limiting unit 236 does not limit the target motor torque by the maximum motor torque or the minimum motor torque. If the difference is not zero, the limiting unit 236 limits the target motor torque by the maximum motor torque or the minimum motor torque.

[0101] The adder 238 sets a second target engine torque by adding the output of the third adder-subtractor 237 and the output of the engine torque calculation unit 233. The adder 238 outputs the second target engine torque to the engine control unit 24. The output of the third adder-subtractor 237 is the difference described above, and the output of the engine torque calculation unit 233 is the torque of the engine 4 predicted from the predicted value of the intake air amount. The second target engine torque is related to the adjustment of the ignition timing. Specifically, when the target motor torque is limited by the minimum motor torque, the ignition timing is retarded from the optimal ignition timing (i.e., the ignition timing during MBT or AWS) so that the torque of the engine 4 decreases. The second target engine torque is a torque achieved by adjusting the ignition timing and corresponds to the transient target engine torque.

[0102] The engine control unit 24 controls the intake air amount and ignition timing of the engine 4 based on the first target engine torque and the second target engine torque. If the ignition timing is retarded by the second target engine torque, the torque of the engine 4 decreases. The increase in motor torque is offset by the decrease in torque of the engine 4. The torque of the engine 4 and the torque of the motor 5 make the torque of the automobile 1 match or substantially match the target torque.

[0103] If the target motor torque is limited by the maximum motor torque, the torque of the motor 5 will decrease relatively. The target torque of the automobile 1 will not be achieved unless the torque of the engine 4 is increased. However, it is difficult to further increase the torque of the engine 4 that is operating with the optimal ignition timing. If the target motor torque is limited by the maximum motor torque in the limiting unit 236, the ignition timing will not be adjusted.

[0104] (Prediction of engine intake air volume) 6 shows functional blocks related to the prediction of the intake air amount in the engine control unit 24. The engine control unit 24 has a throttle opening prediction unit 241, a throttle passing air amount prediction unit 242, a fourth adder / subtractor 243, an intake manifold air amount prediction unit 244, a pressure conversion unit 245, an S-VT change prediction unit 246, a charging efficiency prediction unit 247, and a multiplication unit 248. The engine control unit 24 predicts the intake air amount after a reference time from the present time. The reference time is a fixed time that is set in advance. The reference time can be set arbitrarily, for example, between 10 msec and several tens of msec.

[0105] The throttle opening prediction unit 241 predicts a change in the opening of the throttle valve 43 over time based on the first target engine torque set by the torque distribution unit 23. The throttle opening prediction unit 241 predicts the opening of the throttle valve 43 a reference time from the present time based on the target opening of the throttle valve 43 and characteristic information of the throttle valve 43. The relationship between the target engine torque and the target opening of the throttle valve 43 is stored in the controller 20. The characteristic information of the throttle valve 43 is also stored in the controller 20. The characteristic of the throttle valve 43 may be identified, for example, by conducting an actual vehicle test. As illustrated in FIG. 6, the opening of the throttle valve 43 changes with a delay relative to the operation of the accelerator pedal 19.

[0106] The throttle-passing air amount prediction unit 242 predicts the amount of air that will pass through the throttle valve 43 after a reference time from the present time. Specifically, the throttle-passing air amount prediction unit 242 predicts the amount of air that will pass through the throttle valve 43 using Bernoulli's equation from the opening of the throttle valve 43 predicted by the throttle opening prediction unit 241, the pressure in the intake manifold downstream of the throttle valve 43, and the intake pressure upstream of the throttle valve 43. The intake manifold pressure is a value converted into pressure by a pressure conversion unit 245 from the amount of air in the intake manifold after a reference time from the present time, as will be described later. The intake pressure upstream of the throttle valve 43 can be obtained from a measurement signal of the intake pressure sensor 52, for example.

[0107] A fourth adder / subtractor 243 subtracts the amount of intake air into the cylinder, which will be described later, from the amount of air passing through the throttle valve 43 a reference time after the present time, which is predicted by the throttle-passing air amount prediction unit 242 .

[0108] An intake manifold air amount prediction unit 244 predicts the amount of air in the intake manifold after a reference time from the present time based on the output of the fourth adder-subtractor 243.

[0109] As described above, the pressure conversion unit 245 converts the amount of air in the intake manifold predicted by the intake manifold air amount prediction unit 244 after a reference time from the present time into pressure in the intake manifold and outputs it to the throttle passing air amount prediction unit 242.

[0110] Similar to the throttle opening prediction unit 241, the S-VT change prediction unit 246 predicts changes in the intake valve opening / closing timing caused by the intake S-VT 44 over time based on the first target engine torque. The S-VT change prediction unit 246 predicts the intake valve opening / closing timing after a reference time from the present time based on the target intake valve opening / closing timing and characteristic information of the intake S-VT 44. The relationship between the target engine torque and the target intake valve opening / closing timing is stored in the controller 20. The characteristic information of the intake S-VT 44 is also stored in the controller 20. The characteristic of the intake S-VT 44 may be identified, for example, by conducting an actual machine test. As illustrated in FIG. 6, the opening / closing timing of the intake valve changes with a delay relative to the operation of the accelerator pedal 19.

[0111] The charging efficiency prediction unit 247 predicts the charging efficiency from the current time after a reference time based on the intake valve opening / closing timing from the current time after a reference time, which is predicted by the S-VT change prediction unit 246. The controller 20 stores in advance a map that shows the relationship between the intake valve opening / closing timing, the operating state of the engine 4, and the charging efficiency. The charging efficiency prediction unit 247 predicts the charging efficiency from the current time after a reference time based on the map stored in the controller 20.

[0112] Multiplication unit 248 predicts the amount of intake air into the cylinders after the reference time from the current time by multiplying the amount of air in the intake manifold after the reference time from the current time predicted by intake manifold air amount prediction unit 244 by the charging efficiency after the reference time from the current time predicted by charging efficiency prediction unit 247. The predicted intake air amount is used to control engine 4, and is also output to engine torque calculation unit 233 of torque distribution unit 23, as described above.

[0113] (Control example) Figure 8 shows an example of control by the vehicle driving force control device. The time chart in Figure 8 includes operation of accelerator pedal 19, changes in target torque of automobile 1, changes in target intake air amount, changes in predicted intake air amount, changes in predicted engine torque value, changes in target motor torque, and changes in ignition timing. This control example corresponds to a case where automobile 1 accelerates when the driver depresses accelerator pedal 19 while automobile 1 is running in HEV mode.

[0114] First, at time t1, the driver depresses the accelerator pedal 19. The torque conversion unit 21 and the torque arbitration unit 22 set a target torque for the automobile 1 in response to this operation of the accelerator pedal 19. This target torque is realized by the torque of the engine 4 and the torque of the motor 5. In the control example of FIG. 8, the target torque increases stepwise at time t1.

[0115] The torque distribution unit 23 sets the target engine torque so as to correspond to the change in the target torque. The target engine torque increases in a stepwise manner, just like the target torque. A target intake air amount for the engine 4 is set so as to correspond to the target engine torque. The target intake air amount also increases in a stepwise manner at time t1. The opening of the throttle valve 43 changes so as to achieve the target intake air amount. As described above, the change in the opening of the throttle valve 43 is delayed relative to the operation of the accelerator pedal 19, so the throttle opening changes gradually over time, as shown by the dashed dotted line in Figure 8.

[0116] As described above, the engine control unit 24 predicts a change in the throttle opening and, based on that, predicts the intake air amount after a reference time from the present time. The predicted intake air amount gradually increases over time from time t2, which is delayed from time t1, to correspond to the change in the throttle opening.

[0117] The engine torque calculation unit 233 of the torque distribution unit 23 calculates engine torque from the predicted intake air amount. The engine torque calculation unit 233 predicts the torque of the engine 4 when, for example, the ignition plug 41 ignites at MBT. The phase adjustment unit 234 adjusts the phase of the torque of the engine 4. In the control example of FIG. 8, a delay time is set because the rotation speed of the engine 4 is relatively low. The predicted engine torque gradually increases over time from time t3, which is delayed from time t1. In response to the increase in the intake air amount, the ignition timing changes after time t3. It is assumed that the ignition timing is MBT even after time t3.

[0118] The torque distribution unit 23 sets the target motor torque based on the target torque and the predicted engine torque value. The target motor torque is set so as to compensate for the delay in the torque change of the engine 4. Between times t1 and t3, the torque of the engine 4 does not change (i.e., the torque does not increase). Therefore, the target motor torque increases stepwise at time t1, thereby realizing the target torque. The response delay of the torque change of the automobile 1 in response to the operation of the accelerator pedal 19 is suppressed.

[0119] After time t3, the target motor torque gradually decreases in response to the gradual increase in the torque of the engine 4. The torque change of the engine 4 and the torque change of the motor 5 are synchronized. This suppresses the deviation between the actual torque of the automobile 1 and the target torque. The target torque is achieved even after time t3.

[0120] Unlike FIG. 8, when the driver releases the accelerator pedal 19 and the vehicle 1 decelerates, this driving force control device causes the motor 5 to compensate for the delay in the torque reduction of the engine 4. This reduces the response delay in the torque change of the vehicle 1 in response to the operation of the accelerator pedal 19, and also reduces the deviation between the actual torque of the vehicle 1 and the target torque. Furthermore, because the motor 5 compensates when the torque of the engine 4 is reduced, the engine 4 can reduce the torque by reducing the intake air amount while maintaining MBT without retarding the ignition timing. This improves the fuel efficiency of the vehicle 1.

[0121] (Variation) Fig. 9 shows a modified example of the torque distribution unit 230. Fig. 9 shows some functional blocks of the torque distribution unit 230. The torque distribution unit 230 has an SOC management unit 231, a first adder-subtractor 232 (omitted in Fig. 9), an engine torque calculation unit 233, a phase adjustment unit 234, a second adder-subtractor 235, a limiting unit 236, a third adder-subtractor 237, an adder 238, and a second adder 239.

[0122] As described above, the engine torque calculation unit 233 predicts the future torque of the engine 4 based on the intake air amount predicted by the engine control unit 24. The phase adjustment unit 234 adjusts the phase of the torque of the engine 4 in accordance with the rotation speed of the engine 4.

[0123] 5, the second adder-subtractor 235 calculates the difference between the predicted engine torque and the first target engine torque. The second adder-subtractor 235 calculates the delay in the torque response of the engine 4. This difference corresponds to the torque that the motor 5 should supplement.

[0124] The second adder 239 adds the output of the second adder-subtractor 235 and the output of the SOC management unit 231. The output of the second adder-subtractor 235 is the difference between the predicted engine torque and the first target engine torque. As described above, the output of the SOC management unit 231 is the target motor torque set based on the target torque of the automobile 1 and the battery information. In other words, the second adder 239 corrects the target motor torque set by the SOC management unit 231 so as to compensate for the delay in the torque response of the engine 4.

[0125] If the difference in the second adder-subtractor 235 is zero, the target motor torque set by the SOC management unit 231 is not corrected.

[0126] The limiting unit 236 sets the final target motor torque in the same manner as described above, based on the target motor torque corrected by the second adder 239, the maximum motor torque, and the minimum motor torque. As described above, the third adder-subtractor 237 and the adder 238 set the second target engine torque so that the torque of the engine 4 decreases when the target motor torque is limited by the minimum motor torque.

[0127] In the modified example, the target motor torque is also set to compensate for the delay in the torque response of the engine 4, thereby suppressing the delay in the response of the torque change of the automobile 1 to the operation of the accelerator pedal 19. Furthermore, since the target motor torque is based on a torque prediction of the engine 4 in the future rather than the present time, it is possible to eliminate or substantially eliminate the difference between the actual torque and the target torque.

[0128] Fig. 10 shows a basic control flow of a driving force control device having the torque distribution unit 230 of Fig. 9. Note that in this control flow, steps related to some of the functional blocks of the torque distribution unit 230 of Fig. 9 are omitted.

[0129] First, in step S11, the controller 20 reads the accelerator operation by the driver based on the measurement signal of the accelerator position sensor 51. In the following step S12, the torque conversion unit 21 and the torque mediation unit 22 set the target torque of the automobile 1.

[0130] In step S13, the SOC management unit 231 sets a target motor torque.

[0131] Meanwhile, in step S14, the first adder-subtractor 232 sets a target engine torque from the target torque and target motor torque of the automobile 1. In step S15, the engine control unit 24 sets control target values ​​for the throttle valve 43, the injector 42, the spark plug 41, and the intake S-VT 44. In the following step S16, the engine control unit 24 outputs control signals to each of the throttle valve 43, the injector 42, the spark plug 41, and the intake S-VT 44 based on the control target values ​​set in step S15. The engine 4 is controlled by the controller 20.

[0132] In parallel with this control flow process, the engine torque calculation unit 233 and the phase adjustment unit 234 predict engine torque in the future based on the target engine torque. In step S17, the predicted engine torque is read. In the following step S18, the second adder-subtractor 235 calculates the difference between the predicted engine torque and the first target engine torque, and the controller 20 determines whether the predicted engine torque and the first target engine torque do not match. If the determination in step S18 is No, the process proceeds to step S19. If the determination in step S18 is Yes, the process proceeds to step S20.

[0133] In step S20, the controller 20 corrects the target motor torque after the set time period relative to the current time point. That is, the second adder 239 adds the difference between the predicted engine torque and the first target engine torque to the target motor torque.

[0134] In step S21, the controller 20 determines whether or not a set time has elapsed for predicting the torque of the engine 4. If the determination in step S21 is No, the process repeats step S21, and if the determination in step S21 is Yes, the process proceeds to step S22.

[0135] In step S22, the motor control unit 25 outputs a control signal related to the corrected target motor torque to the inverter 7. This synchronizes the torque change of the motor 5 with the torque change of the engine 4. This suppresses the response delay of the torque change in response to the operation of the accelerator pedal 19, and also suppresses the deviation between the target torque of the automobile 1 and the actual torque. The target torque of the automobile 1 is achieved.

[0136] If the target motor torque is not corrected, in step S19, motor control unit 25 outputs a control signal related to the target motor torque set in step S13 to inverter 7. Motor 5 is controlled via inverter 7, and the target motor torque, and therefore the target torque of automobile 1, is achieved.

[0137] (summary) Therefore, the driving force control device of the vehicle is a motor 5 supplied with power to generate torque for running the vehicle; an engine 4 that burns fuel in its cylinders to generate torque for running the vehicle; a controller 20 that receives an accelerator operation signal and outputs a control signal corresponding to the accelerator operation to the motor 5 and the engine 4; The controller 20 sets a target torque of the vehicle corresponding to the accelerator operation (torque conversion unit 21, torque arbitration unit 22), distributes a target engine torque from the target torque of the vehicle in accordance with a predetermined distribution rule (torque distribution units 23, 230), and outputs a control signal corresponding to the target engine torque to the engine 4 (engine control unit 24). The controller 20 predicts the amount of intake air into the cylinder in the future based on the target engine torque (engine control unit 24, FIG. 6), and predicts the torque of the engine 4 in the future based on the predicted amount of intake air (engine torque calculation unit 233). The controller 20 sets a target motor torque based on the predicted torque of the engine 4 so that the target torque of the vehicle will be achieved in the future (second adder / subtractor 235, limiting unit 236, second adder 239), and outputs a control signal corresponding to the target motor torque to the motor 5 (motor control unit 25).

[0138] Since the highly responsive motor 5 compensates for the response delay of the engine 4, this driving force control device reduces the response delay of torque changes in response to accelerator operation.

[0139] Furthermore, since the target motor torque is set based on the predicted future engine torque, this driving force control device can eliminate or substantially eliminate the deviation between the actual torque and the target torque.

[0140] The controller 20 sets the target motor torque so as to complement the difference between the predicted torque of the engine 4 and the target engine torque (second adder-subtractor 235, second adder 239, FIG. 9).

[0141] This allows the motor 5 to compensate for the response delay of the engine 4.

[0142] The controller 20 predicts the torque of the engine 4 in the future from the present time based on the predicted intake air amount and the optimum ignition timing determined from the operating state of the engine 4 (engine torque calculation unit 233).

[0143] The motor 5 can assist the engine 4 appropriately.

[0144] The controller 20 sets the target motor torque to a value equal to or greater than the minimum torque that the motor 5 can generate (limiting unit 236), When the target motor torque is limited by the minimum torque, the controller 20 retards the ignition timing of the engine 4 from the optimal ignition timing so that the torque of the engine 4 decreases (third adder / subtractor 237, adder 238).

[0145] This prevents the vehicle torque from exceeding the target torque.

[0146] The controller 20 A change in the opening of the throttle valve 43 of the engine 4 after an accelerator pedal operation is predicted based on the target engine torque (throttle opening prediction unit 241); The amount of air passing through the throttle valve 43 is predicted from the predicted opening degree of the throttle valve 43 and the pressure of the intake manifold of the engine 4 (throttle passing air amount prediction unit 242), The amount of air in the intake manifold is predicted from the predicted amount of air passing through the throttle valve 43 (intake manifold air amount prediction unit 244), The amount of intake air into the cylinder is predicted from the predicted amount of air in the intake manifold (multiplication unit 248).

[0147] The controller 20 can predict the amount of intake air into a cylinder in the future rather than at the present time.

[0148] The controller 20 A change in the opening and closing timing of the intake valve of the engine 4 after an accelerator pedal operation is predicted based on the target engine torque (S-VT change prediction unit 246), A charging efficiency is predicted from the predicted intake valve opening / closing timing (charging efficiency prediction unit 247), The amount of intake air into the cylinder is predicted from the predicted charging efficiency and the predicted amount of air in the intake manifold (multiplication unit 248).

[0149] The controller 20 can accurately predict the amount of intake air into the cylinder in the future relative to the present time. [Explanation of symbols]

[0150] 4 Engine 5 motors 20 Controller 43 Throttle valve

Claims

1. a motor supplied with power to generate torque for vehicle travel; an engine that burns fuel in cylinders to generate torque for running the vehicle; a controller that receives an accelerator operation signal and outputs a control signal corresponding to the accelerator operation to the motor and the engine; the controller sets a target torque of the vehicle corresponding to the accelerator operation, distributes a target engine torque from the target torque of the vehicle in accordance with a predetermined distribution rule, and outputs a control signal corresponding to the target engine torque to the engine; the controller predicts an intake air amount into the cylinder in the future based on the target engine torque, and predicts a torque of the engine in the future based on the predicted intake air amount; the controller sets a target motor torque based on the predicted torque of the engine so that a target torque of the vehicle will be achieved in the future, and outputs a control signal corresponding to the target motor torque to the motor; the controller predicts the torque of the engine in the future based on the predicted intake air amount and an optimal ignition timing determined from the operating state of the engine; the controller sets the target motor torque to be equal to or greater than the minimum torque that the motor can generate; A driving force control device for a vehicle, wherein the controller retards the ignition timing of the engine from the optimal ignition timing so that the torque of the engine decreases when the target motor torque is limited by the minimum torque.

2. 2. The vehicle driving force control device according to claim 1, A driving force control device for a vehicle, wherein the controller sets the target motor torque so as to compensate for a difference between the predicted engine torque and the target engine torque.

3. 2. The vehicle driving force control device according to claim 1, The controller predicting a change in the opening of a throttle valve of the engine after an accelerator pedal operation based on the target engine torque; predicting an amount of air passing through the throttle valve from the predicted opening of the throttle valve and a pressure in an intake manifold of the engine; predicting an amount of air in the intake manifold from the predicted amount of air passing through the throttle valve; A driving force control device for a vehicle that predicts an intake air amount to the cylinder from the predicted air amount in the intake manifold.

4. 4. The vehicle driving force control device according to claim 3, The controller predicting a change in the opening and closing timing of an intake valve of the engine after an accelerator pedal operation based on the target engine torque; predicting a charging efficiency from the predicted intake valve opening and closing timing; A driving force control device for a vehicle that predicts an intake air amount to the cylinder from a predicted filling efficiency and a predicted air amount in the intake manifold.

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