Vehicular control device

Abstract

To make both suppression of vibration and attainment of torque responsiveness in accordance with a running mode compatible.SOLUTION: A vehicular control device is used in a vehicle provided with at least one power source that outputs power to a driving shaft connected to an axle, controls the power source so that the vehicle runs in one running mode selected out of a plurality of running modes, and also controls the power source so that torque outputted to the driving shaft when an accelerator is turned off gradually decreases over a target decreasing-time toward torque which is required when the accelerator is turned off. The vehicular control device sets the target decreasing-time so that the time is equal to n-times a reciprocal of resonant frequency of a driving system including the driving source, where n is an integer being one or more and is changed depending on the running mode.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a vehicle control device. [Background technology]

[0002] Conventionally, a vehicle control device of this type has been proposed for use in a vehicle equipped with at least one power source that outputs power for running (see, for example, Patent Document 1). In this device, the time period for changing the magnitude of the torque output by the drive source is set to the reciprocal of the lowest resonance frequency among multiple resonance members in the transmission path from the power source to the body. This suppresses vehicle vibration. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-99059 Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, vehicle control devices control the torque output to the drive shaft when the accelerator is released, gradually decreasing the torque from a positive drive torque to a negative torque (braking torque) required when the accelerator is released. This control can cause vibrations due to torsion of the drive shaft when the torque output to the drive shaft changes from positive to negative. One way to suppress such vibrations is to reduce the rate at which the torque output to the drive shaft is changed, thereby suppressing torsion and vibration. However, this method results in poor torque response because the torque output to the drive shaft changes slowly. In particular, vehicle control devices that control a power source so that the vehicle runs in one selected driving mode from among multiple driving modes may not be able to achieve the desired torque response depending on the driving mode.

[0005] The vehicle control device of the present disclosure has a primary object to achieve both vibration suppression and torque responsiveness according to the driving mode. [Means for solving the problem]

[0006] The vehicle control device of the present disclosure employs the following means to achieve the above-mentioned main object.

[0007] The vehicle control device of the present disclosure includes: A vehicle control device is used in a vehicle having at least one power source that outputs power to a drive shaft connected to an axle, and controls the power source so that the vehicle runs in one selected driving mode from among a plurality of driving modes, and also controls the power source so that, when an accelerator is released, the torque output to the drive shaft gradually decreases over a target reduction time toward the required torque at the time of accelerator release, The target lowering time is set to be n times the reciprocal of the resonance frequency of the drive system including the power source, The n is an integer equal to or greater than 1, and is changed depending on the driving mode. The gist of this is as follows.

[0008] In the vehicle control device disclosed herein, the target reduction time is set to n times the reciprocal of the resonance frequency of the drivetrain including the power source, where n is an integer greater than or equal to 1, and is changed according to the driving mode. By setting n to an integer greater than or equal to 1, vibration can be suppressed. Furthermore, by changing n according to the driving mode, the torque output from the power source can be gradually reduced over the target reduction time according to the driving mode when the accelerator is released. This makes it possible to achieve torque responsiveness according to the driving mode. As a result, it is possible to achieve both vibration suppression and torque responsiveness according to the driving mode.

[0009] In the vehicle control device of the present invention, the multiple modes may include a first mode and a second mode that places more emphasis on output response of torque for driving than in the first mode, and when the driving mode is the second mode, n may be smaller than in the first mode. In this way, when the driving mode is the second mode, the target lowering time can be shorter than in the first mode, and the torque output to the drive shaft can be reduced more quickly. This improves torque response in the second mode.

[0010] In a vehicle control device according to the present disclosure, in which the plurality of modes include a first mode and a second mode that places more importance on output response of torque for driving than in the first mode, when the driving mode is the second mode, and a predetermined condition is met that prohibits rapid reduction of the torque output to the drive shaft, n may be made larger than when the predetermined condition is not met. In this way, when the predetermined condition is met, the time for reducing the torque output from the power source can be made longer. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram showing the outline of the configuration of a hybrid vehicle 20. FIG. [Figure 2] FIG. 2 is a diagram showing the outline of the configuration of an engine 22. [Figure 3] 4 is a flowchart showing an example of a control routine. [Figure 4] FIG. 4 is an explanatory diagram showing an example of the relationship between vehicle speed V and required torque Tout*. [Figure 5] 4 is a flowchart showing the relationship between the shaft torque Tax* and the elapsed time toff. DETAILED DESCRIPTION OF THE INVENTION

[0012] Next, an embodiment of the present disclosure will be described. Fig. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 equipped with a vehicle control device according to an embodiment of the present disclosure. Fig. 2 is a configuration diagram showing an outline of the configuration of an engine 22 equipped in the hybrid vehicle 20. The hybrid vehicle 20 of the embodiment includes the engine 22 and a motor 30 as power sources, an inverter 32, a clutch K0, an automatic transmission 40, and a hybrid electronic control unit (hereinafter referred to as "HVECU") 70.

[0013] 2, the engine 22 is configured as a gasoline-fueled internal combustion engine. The engine 22 has a port injection valve 126 that injects fuel into an intake port and an in-cylinder injection valve 127 that injects fuel into a cylinder, and operates in one of a port injection mode, an in-cylinder injection mode, and a combined injection mode. In the port injection mode, air from an air cleaner 122 is drawn into an intake pipe 123 and passes through a throttle valve 124 and a surge tank 125. Fuel is injected from a port injection valve 126 downstream of the surge tank 125 into the intake pipe 123, mixing the air and fuel. This mixture is drawn into a combustion chamber 129 via an intake valve 128 and is explosively combusted by an electric spark generated by a spark plug 130. The reciprocating motion of a piston 132, which is pushed down in the cylinder bore by the energy generated, is converted into the rotational motion of the crankshaft 23. In the direct injection mode, air is drawn into the combustion chamber 129, and fuel is injected from the direct injection valve 127 during the intake stroke or compression stroke. The fuel is then explosively combusted by an electric spark from the spark plug 130, generating rotational motion of the crankshaft 23. In the shared injection mode, fuel is injected from both the port injection valve 126 and the direct injection valve 127. Exhaust gas discharged from the combustion chamber 129 into an exhaust pipe 134 via an exhaust valve 133 is then discharged through an exhaust system including a purification device 135 and a gasoline particulate filter (hereinafter referred to as "GPF") 136. The purification device 135 has a purification catalyst (three-way catalyst) 135a that purifies harmful components in the exhaust, such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). The GPF 136 is formed as a porous filter made of ceramics, stainless steel, or the like, and captures particulate matter (PM) such as soot in the exhaust. Instead of the GPF 136, a four-way catalyst may be used that combines the purification function of a three-way catalyst with the function of trapping particulate matter.

[0014] The operation of the engine 22 is controlled by an engine electronic control unit (hereinafter referred to as "engine ECU") 24. The engine ECU 24 receives, for example, a crank angle θcr from a crank position sensor 140 that detects the rotational position of a crankshaft 23 of the engine 22, and a coolant temperature Tw from a water temperature sensor 142 that detects the temperature of the coolant for the engine 22. The engine ECU 24 also receives as inputs the following: cam angles θci and θco from a cam position sensor 144 that detects the rotational position of an intake camshaft that opens and closes the intake valve 128 and the rotational position of an exhaust camshaft that opens and closes the exhaust valve 133; a throttle opening TH from a throttle valve position sensor 124a that detects the position of the throttle valve 124; an intake air amount Qa from an air flow meter 123a attached to the intake pipe 123 upstream of the throttle valve 124; an intake air temperature Ta from a temperature sensor 123t attached to the intake pipe 123 upstream of the throttle valve 124; and a surge pressure Ps from a pressure sensor 125a attached to a surge tank 125. Furthermore, the engine ECU 24 also receives as input a catalyst temperature Tcat from a temperature sensor 135b that detects the temperature of the purification catalyst 135a, a front air-fuel ratio AF1 from a front air-fuel ratio sensor 137 that is attached upstream of the purification device 135 in the exhaust pipe 134, a rear air-fuel ratio AF2 from a rear air-fuel ratio sensor 138 that is attached between the purification device 135 in the exhaust pipe 134 and the GPF 136, and a differential pressure ΔP from a differential pressure sensor 136a that detects the differential pressure before and after the GPF 136 (the differential pressure between the upstream side and the downstream side).

[0015] The engine ECU 24 outputs, for example, a control signal to a throttle valve 124, a control signal to a port injection valve 126, a control signal to an in-cylinder injection valve 127, a control signal to an ignition plug 130, and the like.

[0016] The engine ECU 24 calculates the rotation speed Ne of the engine 22 based on the crank angle θcr of the engine 22 from the crank position sensor 140. The engine ECU 24 also calculates the load factor KL (the ratio of the volume of air actually taken in one cycle to the stroke volume per cycle of the engine 22) based on the intake air amount Qa from the air flow meter 123a and the rotation speed Ne of the engine 22.

[0017] The motor 30 is configured as a synchronous generator motor. A rotating shaft 31, to which the rotor of the motor 30 is fixed, is connected to the crankshaft 23 of the engine 22 via a clutch K0 and to an input shaft 41 of an automatic transmission 40. The inverter 32 is used to drive the motor 30 and is connected to a power line 61. The motor 30 is driven and rotated by a motor electronic control unit (hereinafter referred to as the "motor ECU") 34 controlling the switching of multiple switching elements of the inverter 32. The motor ECU 34 receives inputs such as a rotational position θmg from a rotational position sensor 30a that detects the rotational position of the rotor (rotating shaft 31) of the motor 30 and phase currents Iu and Iv from current sensors that detect the phase currents of each phase of the motor 30, and outputs control signals to the inverter 32. The motor ECU 34 calculates the rotational speed Nmg of the motor 30 based on the rotational position θmg of the rotor (rotating shaft 31) of the motor 30 from the rotational position sensor 30a.

[0018] The clutch K0 is configured as, for example, a hydraulically driven friction clutch, and is controlled by the HVECU 70 to connect and disconnect the crankshaft 23 of the engine 22 and the rotary shaft 31 of the motor 30.

[0019] The automatic transmission 40 includes a torque converter 43 and, for example, a six-speed automatic transmission 45. The torque converter 43 is configured as a typical fluid power transmission device and amplifies the torque of the input shaft 41 connected to the rotary shaft 31 of the motor 30 and transmits it to a transmission input shaft 44, which is the input shaft of the automatic transmission 45, or transmits the torque directly without amplifying it. The automatic transmission 45 includes the transmission input shaft 44, an output shaft 42 connected to drive wheels 49 via a differential gear 48, multiple planetary gears, and multiple hydraulically driven friction engagement elements (clutches, brakes). The automatic transmission 45 establishes forward gears (first through sixth gears) and reverse gears by engaging and disengaging the multiple friction engagement elements, and transmits power between the transmission input shaft 44 and the output shaft 42. The clutch K0 and the automatic transmission 45 are supplied with hydraulic oil from a mechanical oil pump or an electric oil pump after the hydraulic pressure is adjusted by a hydraulic control device (not shown).

[0020] The battery 60 is configured as, for example, a lithium ion secondary battery or a nickel-metal hydride secondary battery with a rated voltage of about several hundred volts, and is connected to the power line 61 together with the inverter 32 .

[0021] The HVECU 70 is configured as a microcomputer. The HVECU 70 receives inputs such as the rotation speed Nin from a rotation speed sensor 41a attached to the input shaft 41 of the automatic transmission 40, the rotation speed Nmi from a rotation speed sensor 44a attached to the transmission input shaft 44 of the automatic transmission 40, and the rotation speed Nout from a rotation speed sensor 42a attached to the output shaft 42 of the automatic transmission 40. The HVECU 70 also receives inputs such as the voltage Vb of the battery 60 from a voltage sensor attached between the terminals of the battery 60 and the current Ib of the battery 60 (a positive value when discharging from the battery 60) from a current sensor attached to the output terminal of the battery 60. The HVECU 70 also receives an ignition signal from an ignition switch 80, a shift position SP from a shift position sensor 82 that detects the operating position of a shift lever 81, an accelerator opening Acc from an accelerator pedal position sensor 84 that detects the depression amount of an accelerator pedal 83, a brake pedal position BP from a brake pedal position sensor 86 that detects the depression amount of a brake pedal 85, and a vehicle speed V from a vehicle speed sensor 87. Another example of an input signal is an operation signal from a mode switch 88. The mode switch 88 is a switch that toggles the driving mode between normal mode, sport mode, and eco mode in this order each time the driver operates it. The sport mode (second mode) is a mode that places more emphasis on output responsiveness of driving torque than the normal mode and eco mode (first mode). The eco mode is a mode that places more emphasis on energy efficiency than the normal mode and sport mode.

[0022] The HVECU 70 outputs various control signals via an output port. For example, these include control signals to the clutch K0 and the automatic transmission 40 (hydraulic control device). The HVECU 70 is connected to the engine ECU 24 and the motor ECU 34 via a communication port. The HVECU 70 calculates the battery 60's power storage percentage SOC and input / output limits Win and Wout as the maximum allowable power that can be input and output to the battery 60 based on the battery 60's voltage Vb and current Ib.

[0023] In the hybrid vehicle 20 of this embodiment configured as described above, the engine 22, clutch K0, motor 30, and automatic transmission 40 are controlled by cooperative control between the HVECU 70, engine ECU 24, and motor ECU 34 so that the vehicle runs in hybrid driving mode (HV driving mode) or electric driving mode (EV driving mode).

[0024] In controlling the engine 22 and motor 30 in the HV driving mode, the HVECU 70 first sets a required torque Tout* (a positive value is a driving torque, and a negative value is a braking torque) for the output shaft 42 as a drive shaft based on the accelerator pedal position Acc and the vehicle speed V. Next, the HVECU 70 sets a required torque Tin* for the input shaft 41 by dividing the required torque Tout* for the output shaft 42 by the rotation speed ratio Gt of the automatic transmission 40. Then, the HVECU 70 sets a target torque Te* for the engine 22 and a torque command Tm* for the motor 30 so that the required torque Tin* is output to the input shaft 41 while charging and discharging the battery 60 within the ranges of the input / output limits Win and Wout, and transmits the target torque Te* to the engine ECU 24 and the torque command Tm* to the motor ECU 34. The engine ECU 24 calculates the required load rate KL* from the target torque Te* and performs operation control (intake air amount control, fuel injection control, ignition control, etc.) of the engine 22 so that the engine 22 operates at the target torque Te*. In the ignition control, the engine ECU 24 sets the ignition timing of the engine 22 to efficiency ignition timing Tfref for efficiently operating the engine 22. The motor ECU 34 performs switching control of multiple switching elements of the inverter 32 so that the motor 30 is driven by the torque command Tm*.

[0025] In controlling the engine 22 and motor 30 in the EV driving mode, the HVECU 70 first sets the required torque Tout* in the same manner as in the HV driving mode. Next, the HVECU 70 sets the required torque Tin* of the input shaft 41, obtained by dividing the required torque Tout* of the output shaft 42 by the rotation speed ratio Gt of the automatic transmission 40. Then, the HVECU 70 sets a torque command Tm* of the motor 30 so that the required torque Tin* is output to the input shaft 41 and the battery 60 is charged / discharged within the input / output limits Win and Wout. The HVECU 70 then sends a stop command for the engine 22 to the engine ECU 24 and sends the torque command Tm* to the motor ECU 34. The engine ECU 24 stops the engine 22. The motor ECU 34 controls the switching of multiple switching elements of the inverter 32 so that the motor 30 is driven by the torque command Tm*.

[0026] In the hybrid vehicle 20 of this embodiment, the engine ECU 24 executes ignition retard control to make the ignition timing of the engine 22 later (retarded) than the efficiency ignition timing Tfref in order to raise the temperature of the purification catalyst 135a in the purification device 135, ignition retard control to make the ignition timing of the engine 22 later than the efficiency ignition timing Tfref in order to warm up the GPF 136, and ignition retard control to make the ignition timing of the engine 22 later than the efficiency ignition timing Tfref when the engine 22 is idling. Furthermore, when the catalyst temperature Tcat detected by the temperature sensor 135b exceeds a threshold value Tcat1, the execution of these ignition retard controls is prohibited in order to suppress a rise in the temperature of the purification catalyst 135a. The threshold value Tcat1 is a threshold value for determining whether the purification catalyst 135a in the purification device 135 will reach a high temperature if the ignition retard control is executed. When the execution of the ignition retard control is prohibited, the ignition timing of the engine 22 is set to the efficiency ignition timing Tfref.

[0027] Next, the operation of the hybrid vehicle 20 equipped with the vehicle control device of the embodiment configured as described above, particularly the operation of the engine 22 and the motor 30 when the accelerator pedal 83 is released, will be described. Figure 3 is a flowchart showing an example of a control routine executed by the HVECU 70. This routine is executed when the accelerator is released. Note that if the accelerator is pressed while this routine is being executed, the execution of this routine is stopped, and the above-mentioned control of the HV driving mode or EV driving mode is executed.

[0028] When this routine is executed, the HVECU 70 executes a process of inputting the vehicle speed V (S100). The vehicle speed V detected by the vehicle speed sensor 87 is input.

[0029] Next, the required torque Tout* is set based on the input vehicle speed V (S110). FIG. 4 is an explanatory diagram showing an example of the relationship between the vehicle speed V and the required torque Tout* when the accelerator is released. In the diagram, the required torque Tout* has a positive value for torque on the driving side and a negative value for torque on the braking side. The required torque Tout* is the torque output to the output shaft 42 when the accelerator is released in a vehicle that runs on power from the engine without a driving motor, that is, a torque that simulates engine braking. As shown in the diagram, when the vehicle speed V is below a threshold value Vref, the required torque Tout* is set to a predetermined torque Toref that is greater than the value 0. When the vehicle speed V is equal to or greater than the threshold value Vref, the required torque Tout* is set to a value less than 0 when the vehicle speed V is high compared to when the vehicle speed V is low.

[0030] Next, the driving mode set by the mode switch 88 is checked (S120). If the driving mode is normal mode or eco mode, the coefficient n used when setting the target reduction time td in S160 is set to a value of 2 (S140). Then, the target reduction time td is set to the product of the inverse of the resonance frequency f of the drivetrain including the engine 22, the motor 30, and the automatic transmission 40 multiplied by the coefficient n (here, the value 2) (S160). Then, the elapsed time toff since the accelerator pedal 83 was released is input (S170). Next, using the following equation (1), the axial torque Tax* output to the output shaft 42 is set so that the axial torque Tax* gradually decreases toward the required torque Tout* over the target reduction time td within a range that does not fall below the required torque Tout* (S180). In equation (1), "Tout_i" is the required torque Tout* that was set immediately before the accelerator pedal 83 was released. FIG. 5 is an explanatory diagram showing the relationship between the axial torque Tax* and the elapsed time toff. As shown by the dashed line in the figure, the shaft torque Tax* decreases toward the required torque Tout* in a decrease time that is twice the reciprocal of the resonance frequency f (=1 / f).

[0031] Tax*=max(Tout*,(Tout*-Tout_i) / td·toff+Tout_i) ···(1)

[0032] Once the axial torque Tax* is set in this manner, the engine 22 and the motor 30 are controlled so that torque based on the axial torque Tax* is output to the output shaft 42 while charging / discharging the battery 60 within the range of the input / output limits Win and Wout (S190). In this control, the axial torque Tax* divided by the rotation speed ratio Gt of the automatic transmission 40 is set as the required torque Tin* of the input shaft 41. The torque command Tm* of the motor 30 is then set to the larger of the smaller of the required torque Tin* and the output limit Wout and the input limit Win. In other words, the torque command Tm* is set to a value obtained by limiting the required torque Tin* by the input / output limits Win and Wout. In the HV driving mode, a fuel cut command to stop fuel supply to the engine 22 is sent to the engine ECU 24, and the torque command Tm* is sent to the motor ECU 34. In the EV driving mode, a stop command for the engine 22 is sent to the engine ECU 24, and the torque command Tm* is sent to the motor ECU 34. The engine ECU 24 stops the fuel supply to the engine 22 and stops the operation of the engine 22. The motor ECU 34 controls the switching of multiple switching elements of the inverter 32 so that the motor 30 is driven by the torque command Tm*. In this way, the torque output to the output shaft 42 is reduced over a time period that is an integer multiple (here, twice) of the resonance frequency f of the drive system, thereby suppressing vibration due to resonance of the drive system. Then, it is determined whether the shaft torque Tax* has reached the required torque Tout* (S200). If the shaft torque Tax* is not the required torque Tout*, the process returns to S170. If the shaft torque Tax* has reached the required torque Tout*, the routine ends.

[0033] When the driving mode is the sport mode in S120, it is next determined whether or not a predetermined condition for prohibiting a rapid reduction in the torque output to the output shaft 42 is satisfied (130). The predetermined condition includes a first and a second condition. The first condition may be a condition in which the absolute value of the input limit Win (negative value) is smaller than a threshold value Winref. The threshold value Winref is a threshold value for determining whether the absolute value of the input limit Win is small. The second condition may be a condition in which the catalyst temperature Tcat detected by the temperature sensor 135b exceeds the threshold value Tcat1 and the execution of the above-mentioned ignition retard control is prohibited, that is, a condition in which ignition retard is prohibited to suppress a temperature rise of the purification catalyst 135a. The predetermined condition is considered to be satisfied when at least one of the first condition and the second condition is satisfied.

[0034] If the predetermined condition is not met in S130, the coefficient n is set to 1, which is smaller than the coefficient n set in S140 (S150). Then, the reciprocal of the resonance frequency f of the drivetrain is multiplied by the coefficient n (here, the value 1) and set as the target reduction time td (S160). Furthermore, the elapsed time toff is input (S170). Next, using the above-described equation (1), the axial torque Tax* output to the output shaft 42 is set so that it gradually decreases toward the required torque Tout* over the target reduction time td within a range that does not fall below the required torque Tout* (S180). After the axial torque Tax* is set in this manner, the engine 22 and the motor 30 are controlled so that the axial torque Tax* is output to the output shaft 42 (S190), and it is determined whether the axial torque Tax* is the required torque Tout* (S200). If the axial torque Tax* is not the required torque Tout*, the process returns to S170. If the axle torque Tax* is equal to the required torque Tout*, this routine is terminated. When the predetermined condition is not satisfied in S130, the axle torque Tax* decreases toward the required torque Tout* over a reduction time equal to 1 times the reciprocal of the resonance frequency f (=1 / f), as shown by the solid line in FIG. 5. Because the axle torque Tax* decreases at an integral multiple of the reciprocal of the resonance frequency f, vibration in the drivetrain can be suppressed. Furthermore, the torque output to the output shaft 42 can be reduced more quickly than the axle torque Tax* in the normal mode or the eco mode, as shown by the dashed line in FIG. 5. In the sport mode, output response is emphasized, and since the torque output to the output shaft 42 can be reduced more quickly, torque response appropriate for the sport mode can be achieved. This makes it possible to achieve both vibration suppression and torque response appropriate for the driving mode.

[0035] If the predetermined condition is met in S130, the coefficient n is set to a value of 2 (S140). Then, the reciprocal of the resonance frequency f of the drivetrain is multiplied by the coefficient n (here, a value of 1) and set as the target reduction time td (S160). Furthermore, the elapsed time toff is input (S170). Then, using the above-described equation (1), the axial torque Tax* output to the output shaft 42 is set so that it gradually decreases toward the required torque Tout* over the target reduction time td within a range that does not fall below the required torque Tout* (S180). After the axial torque Tax* is set in this manner, the engine 22 and the motor 30 are controlled so that the axial torque Tax* is output to the output shaft 42 (S190), and it is determined whether the axial torque Tax* is the required torque Tout* (S200). If the axial torque Tax* is not the required torque Tout*, the process returns to S170. If the axial torque Tax* is the required torque Tout*, this routine ends. When the predetermined conditions are met in S130, the coefficient n is set to the value 2, so that the torque output to the output shaft 42 can be reduced at the same rate as the shaft torque Tax* in normal mode or eco mode shown by the dashed line in Figure 5.

[0036] When the first condition among the predetermined conditions is met in S130, for example, if the axial torque Tax* set using the above-described equation (1) suddenly decreases to a negative value, the power (negative value) actually used to charge the battery 60 may become smaller than the input limit Win (negative value). In other words, the battery 60 may be charged with power exceeding the input limit Win. When the first condition is met, the coefficient n is increased to lengthen the target reduction time td, thereby suppressing a sudden decrease in the torque output from the motor 30. This prevents the battery 60 from being charged with power exceeding the input limit Win, thereby protecting the battery 60.

[0037] When the second condition of the predetermined conditions is met, if the torque output from the engine 22 is quickly reduced when the accelerator is released, a large amount of intake air is supplied to the purification catalyst 135a, causing the temperature of the purification catalyst 135a to rise. When ignition retard is prohibited, the coefficient n is increased to lengthen the target decrease time td, thereby suppressing a sudden decrease in the torque output from the motor 30. This makes it possible to suppress a rise in the temperature of the purification catalyst 135a and protect the purification catalyst 135a.

[0038] According to the hybrid vehicle 20 equipped with the vehicle control device of the embodiment described above, by setting the target lowering time td to be one or two times the reciprocal of the resonance frequency f of the drivetrain depending on the driving mode, it is possible to achieve both vibration suppression and torque responsiveness depending on the driving mode.

[0039] The multiple modes include a normal mode or an eco mode, and a sport mode that places more emphasis on the output response of the driving torque than the normal mode or the eco mode. When the driving mode is the sport mode, the coefficient n is made smaller than in the normal mode or the eco mode, so that the torque response can be improved in the sport mode.

[0040] Furthermore, when the driving mode is a sports mode, when a predetermined condition is met that prohibits rapid reduction of the torque output to the output shaft 42 as the drive shaft, n is made larger than when the predetermined condition is not met, so that the time for reducing the torque output to the output shaft 42 can be made longer.

[0041] Furthermore, the predetermined condition includes the first condition that limits the torque output from the motor 30 in order to prevent the discharge power of the battery 60 from exceeding the output limit Wout, thereby improving torque responsiveness.

[0042] Furthermore, the predetermined conditions include a second condition in which ignition retardation that delays the ignition timing of the engine 22 is prohibited in order to suppress the temperature rise of the purification catalyst 135a, so that the temperature rise of the purification catalyst 135a can be suppressed and the purification catalyst 135a can be protected.

[0043] In the above-described embodiment, the coefficient n is set to 1 when the driving mode is in sport mode and the predetermined condition is not met, and is set to 2 when the driving mode is in normal mode or eco mode, or when the predetermined condition is met even when the driving mode is in sport mode. However, the coefficient n may be an integer greater than or equal to 1, and when the predetermined condition is not met when the driving mode is in sport mode, the coefficient n may be set to a smaller value than when the driving mode is in normal mode or eco mode, or when the predetermined condition is met even when the driving mode is in sport mode. For example, the coefficient n may be set to 2 when the driving mode is in sport mode and the predetermined condition is not met, and may be set to 4 when the driving mode is in normal mode or eco mode, or when the driving mode is in sport mode and the predetermined condition is met.

[0044] In the above-described embodiment, when the driving mode is the sports mode, if the predetermined condition is not met, the coefficient n is set to 1, and when the predetermined condition is met, the coefficient n is set to 2. However, when the driving mode is the sports mode, the coefficient n may be uniformly set to 1 regardless of whether the predetermined condition is met or not.

[0045] In the above-described embodiment, the predetermined condition includes both the first and second conditions, but it may also include only one of the first and second conditions. Furthermore, the predetermined condition may also include a condition different from the first and second conditions, as long as the condition prohibits a rapid reduction in the torque output to the output shaft 42 serving as the drive shaft.

[0046] In the above-described embodiment, the vehicle control device of the present disclosure is applied to a hybrid vehicle 20 equipped with an engine 22 and a motor 30, but it may also be applied to a hybrid vehicle equipped with an engine 22, a first motor, a planetary gear in which a carrier is connected to the output shaft of the engine 22 and the first motor is connected to a sun gear, and a second motor connected to the ring gear of the planetary gear, or it may be applied to a car equipped with an engine 22 without a motor that outputs power for driving, or it may be applied to a car equipped with a motor without an engine.

[0047] The correspondence between the main elements of the embodiments and the main elements of the invention described in the "Means for Solving the Problem" section does not limit the elements of the invention described in the "Means for Solving the Problem" section, since the embodiments are examples for specifically explaining the mode for implementing the invention described in the "Means for Solving the Problem" section. In other words, the interpretation of the invention described in the "Means for Solving the Problem" section should be based on the description in that section, and the embodiments are merely specific examples of the invention described in the "Means for Solving the Problem" section.

[0048] The above describes embodiments for implementing the present disclosure, but the present disclosure is not limited to these embodiments and can, of course, be implemented in various forms within the scope of the gist of the present disclosure. [Industrial Applicability]

[0049] The present disclosure is applicable to the vehicle control device manufacturing industry and the like. [Explanation of symbols]

[0050] 20 Hybrid Vehicles, 22 Engines, 30 Motors, 44 Input Shafts, 45 Automatic Transmissions, 60 Batteries, 70 HVECUs.

Claims

1. A vehicle control device is used in a vehicle having at least one power source that outputs power to a drive shaft connected to an axle, and controls the power source so that the vehicle runs in one selected driving mode from among a plurality of driving modes, and controls the power source so that, when an accelerator is released, the torque output to the drive shaft gradually decreases over a target reduction time toward the required torque at the time of accelerator release, the target lowering time is set to be n times the reciprocal of a resonance frequency of a drive system including the power source, The n is an integer equal to or greater than 1, and is changed depending on the driving mode. Vehicle control device.

2. 2. The vehicle control device according to claim 1, the plurality of modes include a first mode and a second mode that places more importance on output response of torque for traveling than in the first mode, When the running mode is the second mode, n is made smaller than when the running mode is the first mode. Vehicle control device.

3. 3. The vehicle control device according to claim 2, When the driving mode is the second mode, if a predetermined condition is met that prohibits a rapid reduction in the torque output to the drive shaft, n is made larger than when the predetermined condition is not met. Vehicle control device.

4. 4. The vehicle control device according to claim 3, the vehicle includes a motor as the power source and a battery that exchanges electric power with the motor; The predetermined condition includes a condition in which an absolute value of an input limit as a maximum allowable power that can be input to the battery is smaller than a predetermined threshold value. Vehicle control device.

5. 4. The vehicle control device according to claim 3, The vehicle includes an engine as the power source, and a purification device having a purification catalyst for purifying exhaust gas is attached to an exhaust system of the engine. The predetermined condition includes a condition that prohibits ignition retardation, which retards the ignition timing of the engine, in order to suppress a rise in temperature of the purification catalyst. Vehicle control device.

Images