Vehicle control device

Abstract

To properly measure or set the travel resistance.SOLUTION: A vehicle control device is set to a prescribed mode which is established when a vehicle is subjected to measurement of vehicle travel resistance or the measured travel resistance is set in measurement of a prescribed performance of the vehicle, also, when an automatic transmission is set to a neutral position and the vehicle is set into an accelerator-off inertia travel state, engine intermittent operation is prohibited and charging operation by a motor using power of an engine is prohibited, thereby, variations in vehicle speed change at an inertial travel time due to propagation to drive torque of torque fluctuation following engine intermittent operation and charging operation are suppressed even in a vehicle including the automatic transmission that may generate power transmission by drag of an engagement device even if the automatic transmission is set to the neutral position. Consequently, the travel resistance can be properly measured or set.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a control device for a vehicle equipped with an automatic transmission that transmits power by engaging a wet engagement device. [Background technology]

[0002] A well-known control device for a vehicle includes a power source including an engine and an electric motor, an automatic transmission provided in a power transmission path between the power source and drive wheels, and an electric storage device that supplies and receives electric power to the electric motor. For example, a hybrid vehicle is described in Patent Document 1. Patent Document 1 discloses that, in a hybrid vehicle including a power split integration mechanism that mechanically splits engine power between a first motor and a drive shaft, and a transmission interposed between a second motor and the drive shaft, when a coasting command is issued to measure running resistance, the control device prohibits gear changes in the transmission, stops the engine and the first motor, and controls the second motor to cancel out inertia torque caused by changes in the first motor's rotation speed and acting on the drive shaft via the power split integration mechanism, thereby placing the drive shaft in a fully driven state. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-44630 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a vehicle equipped with an automatic transmission in a power transmission path between a power source and drive wheels, which transmits power from the power source by engaging a wet engagement device, and which has only an engine and one electric motor as its power source, it is not possible to detect engine torque fluctuations with the first electric motor and offset them with the torque of the second electric motor. Therefore, when the balance between engine torque and electric motor torque for charging and discharging is lost, the resulting torque fluctuations are transmitted to the input rotating member of the automatic transmission. In addition, even when the engagement devices of an automatic transmission are disengaged, power transmission can occur due to the drag of the engagement devices via hydraulic oil inside the automatic transmission. Therefore, even when the automatic transmission is in a neutral position where power transmission is disabled, torque fluctuations transmitted to the input rotating member can lead to torque fluctuations in the output rotating member of the automatic transmission. As a result, when the engine is started or stopped or when electric motor torque is applied for charging or discharging, the output rotating member of the automatic transmission may not be in a completely driven state due to only the driven torque input from the drive wheel side, which may result in variations in vehicle speed during coasting and may make it impossible to properly measure running resistance.

[0005] The present invention has been made in light of the above circumstances, and an object of the present invention is to provide a vehicle control device that can appropriately measure or set running resistance. [Means for solving the problem]

[0006] The gist of a first aspect of the present invention is a control device for a vehicle including: (a) a power source including an engine and an electric motor; an automatic transmission that transmits power from the power source by engaging a wet engagement device provided in a power transmission path between the power source and drive wheels; and an electric storage device that supplies and receives electric power to the electric motor; and (b) the control device is configured to: 、 When the running resistance of the vehicle is measured can be established Alternatively, the measured running resistance is set when a predetermined performance of the vehicle is measured. 、When the vehicle is in a predetermined mode, and in addition, the automatic transmission is in a neutral position in which power cannot be transmitted, and the vehicle is in a coasting state with the accelerator off, intermittent engine operation that switches the engine between a running state and a stopped state is prohibited, and charging of the storage device by the electric motor using the power of the engine is prohibited.

[0007] A second aspect of the present invention is the vehicle control device according to the first aspect of the present invention, wherein the control device Even when the vehicle is in the predetermined mode, the automatic transmission is in the neutral position, and the vehicle is in the coasting state, When the vehicle speed is within a predetermined low vehicle speed range including zero, which is not used for measuring the running resistance, the charging operation is permitted.

[0008] Further, a third aspect of the present invention is the vehicle control device according to the first or second aspect of the present invention, wherein the control device: Even when the vehicle is in the predetermined mode, the automatic transmission is in the neutral position, and the vehicle is in the coasting state, When the voltage of the power storage device is in a predetermined low voltage range where forced charging is required, the charging operation is permitted.

[0009] Furthermore, a fourth invention relates to a vehicle control device according to the third invention, in which prohibiting the charging operation means prohibiting the charging operation by the electric motor in a control that maintains the charge amount of the storage device within a predetermined control range by repeatedly discharging and charging the storage device, and the predetermined low voltage range is a voltage range of the storage device for determining whether the charge amount is in an over-discharge range of the storage device that is lower than the lower limit value of the predetermined control range.

[0010] In addition, a fifth invention is a vehicle control device described in any one of the first to fourth inventions, wherein prohibiting intermittent operation of the engine means prohibiting the engine from being stopped.

[0011] Also, others The present invention is directed to a vehicle control device according to any one of the first to fifth inventions, wherein the control device stops functions of the vehicle that are a disturbance to the coasting of the vehicle when the vehicle is in the specified mode. [Effects of the Invention]

[0012] According to the first aspect of the present invention, a vehicle 、 When the rolling resistance of a vehicle is measured can be established Or, it is established when the running resistance measured in measuring the predetermined performance of the vehicle is set. 、 When the vehicle is in the predetermined mode, and in addition, the automatic transmission is in the neutral position and the vehicle is in a coasting state with the accelerator off, intermittent engine operation is prohibited and charging operation by the electric motor using engine power is prohibited. Therefore, even in a vehicle equipped with an automatic transmission in which power transmission can occur due to dragging of the engagement device even in the neutral position, variation in vehicle speed during coasting caused by torque fluctuations associated with intermittent engine operation or charging operation propagating to drive torque is suppressed. Therefore, running resistance can be appropriately measured or set.

[0013] Furthermore, according to the second invention, Even when the vehicle is in a predetermined mode, the automatic transmission is in a neutral position, and the vehicle is in a coasting state, When the vehicle speed is within a predetermined low vehicle speed range including zero, which is not used for measuring running resistance, charging operation is permitted, so that deterioration of the power storage device due to over-discharge can be suppressed.

[0014] Furthermore, according to the third invention, Even when the vehicle is in a predetermined mode, the automatic transmission is in a neutral position, and the vehicle is in a coasting state, When the voltage of the power storage device is in a predetermined low voltage range where forced charging is required, charging is permitted, so that deterioration of the power storage device due to over-discharge can be suppressed.

[0015] Furthermore, according to the fourth aspect of the present invention, prohibiting charging operation means prohibiting charging operation in a control that maintains the charge amount of the storage device within a predetermined control range, and the predetermined low voltage range is a voltage range of the storage device for determining whether the charge amount is in an over-discharge range of the storage device that is lower than the lower limit value of the predetermined control range, so that deterioration of the storage device due to over-discharge can be appropriately suppressed.

[0016] Furthermore, according to the fifth aspect of the present invention, prohibiting intermittent engine operation means prohibiting the engine from being stopped, so that the engine operating state is maintained appropriately when the running resistance is measured or set.

[0017] In addition, the above others According to the invention, when the vehicle is in the predetermined mode, vehicle functions that cause disturbances to the coasting of the vehicle are stopped, so that the running resistance can be measured or set with high accuracy. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a diagram illustrating a schematic configuration of a vehicle to which the present invention is applied, and is also a diagram illustrating main parts of control functions and control systems for various controls in the vehicle. [Figure 2] 1 is a flowchart illustrating a main part of the control operation of the electronic control device, and is a flowchart illustrating the control operation for appropriately measuring or setting the running resistance. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. [Example]

[0020] Fig. 1 is a diagram illustrating the schematic configuration of a vehicle 10 to which the present invention is applied, and also illustrates the main parts of the control functions and control systems for various controls in the vehicle 10. In Fig. 1, the vehicle 10 is a hybrid vehicle equipped with an engine 12 and an electric motor MG that function as a power source SP. The vehicle 10 also has drive wheels 14 and a power transmission device 16 provided in a power transmission path between the engine 12 and the drive wheels 14.

[0021] The engine 12 is a known internal combustion engine such as a gasoline engine, a diesel engine, etc. An electronic control device 90 (described later) controls an engine control device 50 including a throttle actuator, a fuel injection device, an ignition device, etc., provided in the vehicle 10, thereby controlling the engine torque Te, which is the output torque of the engine 12.

[0022] The electric motor MG is a rotating electric machine, a so-called motor generator, that functions as a motor that generates mechanical power from electric power and as a generator that generates electric power from mechanical power. The electric motor MG is connected to a battery 54 provided in the vehicle 10 via an inverter 52 provided in the vehicle 10. The battery 54 is an electricity storage device that supplies and receives electric power to the electric motor MG. The inverter 52 is controlled by an electronic control device 90 (described later), thereby controlling the MG torque Tm, which is the output torque of the electric motor MG. For example, when the rotation direction of the electric motor MG is forward, which is the same as the rotation direction of the engine 12 when it is operating, the MG torque Tm is a powering torque when it is a positive torque on the acceleration side, and a regenerative torque when it is a negative torque on the deceleration side. Specifically, the electric motor MG generates power using electric power supplied from the battery 54. The electric motor MG also generates electric power using the power of the engine 12 and the driven torque input from the drive wheels 14. The battery 54 is charged with the electric power generated by the electric motor MG. The term "electric power" also refers to electrical energy unless otherwise specified. The term "motive power" also refers to driving force, torque, and force unless otherwise specified.

[0023] The power transmission device 16 includes a K0 clutch 20, a torque converter 22, an automatic transmission 24, and other components housed within a case 18, which is a non-rotating member attached to the vehicle body. The K0 clutch 20 is a clutch provided between the engine 12 and the electric motor MG in a power transmission path between the engine 12 and the drive wheels 14. The torque converter 22 is connected to the engine 12 via the K0 clutch 20. The automatic transmission 24 is connected to the torque converter 22 and is disposed in the power transmission path between the torque converter 22 and the drive wheels 14. The torque converter 22 and the automatic transmission 24 are each provided in the power transmission path between the power source SP and the drive wheels 14. The power transmission device 16 also includes a propeller shaft 28 connected to a transmission output shaft 26, which is an output rotating member of the automatic transmission 24, a differential gear 30 connected to the propeller shaft 28, a pair of drive shafts 32 connected to the differential gear 30, and other components. The power transmission device 16 also includes an engine connecting shaft 34 that connects the engine 12 and the K0 clutch 20, an electric motor connecting shaft 36 that connects the K0 clutch 20 and the torque converter 22, and the like.

[0024] The electric motor MG is connected to the electric motor connecting shaft 36 in the case 18 so as to be able to transmit power. In other words, the electric motor MG is connected to the power transmission path between the engine 12 and the drive wheels 14, particularly to the power transmission path between the K0 clutch 20 and the torque converter 22. In other words, the electric motor MG is connected to the torque converter 22 and the automatic transmission 24 so as to be able to transmit power without passing through the K0 clutch 20.

[0025] The torque converter 22 includes a pump wheel 22a connected to an electric motor connecting shaft 36 and a turbine wheel 22b connected to a transmission input shaft 38, which is an input rotating member of the automatic transmission 24. The torque converter 22 is a fluid transmission device that is provided between the electric motor MG and the drive wheels 14 in a power transmission path between the engine 12 and the drive wheels 14 and transmits power from the power source SP from the electric motor connecting shaft 36 to the transmission input shaft 38 via fluid. The torque converter 22 includes an LU clutch 40 that connects the pump wheel 22a and the turbine wheel 22b, i.e., that connects the electric motor connecting shaft 36 and the transmission input shaft 38. The LU clutch 40 is a direct-coupled clutch that connects the input and output rotating members of the torque converter 22, i.e., a known lock-up clutch.

[0026] The automatic transmission 24 is a known planetary gear automatic transmission that includes, for example, one or more planetary gear devices (not shown) and an engagement device CB. The engagement device CB includes, for example, a plurality of hydraulic engagement devices, such as known wet friction engagement devices. Each engagement device CB has its torque capacity, or CB torque Tcb, changed by a CB hydraulic pressure PRcb, which is a regulated hydraulic pressure supplied from a hydraulic control circuit 56 provided in the vehicle 10, thereby switching between operating states, i.e., control states, such as an engaged state, a slip state, and a disengaged state.

[0027] The automatic transmission 24 is a stepped transmission in which one of a plurality of gear stages (also referred to as gear stages) with different speed ratios (also referred to as gear ratios) γat (=AT input rotation speed Ni / AT output rotation speed No) is established by engaging one of the engagement devices CB. The automatic transmission 24 switches between gear stages established in response to the accelerator operation of the driver (=operator), vehicle speed V, etc. by an electronic control device 90 (described later). In other words, the automatic transmission 24 transmits power from the power source SP by engaging the engagement devices CB. The AT input rotation speed Ni is the rotation speed of the transmission input shaft 38 and is the input rotation speed of the automatic transmission 24. The AT input rotation speed Ni is equal to the turbine rotation speed Nt, which is the output rotation speed of the torque converter 22. The AT input rotation speed Ni can be expressed as the turbine rotation speed Nt. The AT output rotation speed No is the rotation speed of the transmission output shaft 26 and is the output rotation speed of the automatic transmission 24.

[0028] The K0 clutch 20 is a hydraulic friction engagement device configured, for example, with a multi-plate or single-plate clutch. The K0 clutch 20 switches between control states such as an engaged state, a slip state, and a released state by changing the K0 torque Tk0, which is the torque capacity of the K0 clutch 20, using the K0 oil pressure PRk0, which is the adjusted oil pressure supplied from the hydraulic control circuit 56.

[0029] In the vehicle 10, when the K0 clutch 20 is engaged, the engine 12 and the torque converter 22 are connected to each other so that power can be transmitted between them. On the other hand, when the K0 clutch 20 is disengaged, power transmission between the engine 12 and the torque converter 22 is interrupted. Because the electric motor MG is connected to the torque converter 22, the K0 clutch 20 functions as a clutch that connects and disconnects the engine 12 from the electric motor MG.

[0030] In the power transmission device 16, when the K0 clutch 20 is engaged, the power output from the engine 12 is transmitted from the engine connecting shaft 34 to the drive wheels 14 via the K0 clutch 20, the electric motor connecting shaft 36, the torque converter 22, the automatic transmission 24, the propeller shaft 28, the differential gear 30, the drive shaft 32, etc. in this order. Furthermore, regardless of the control state of the K0 clutch 20, the power output from the electric motor MG is transmitted from the electric motor connecting shaft 36 to the drive wheels 14 via the torque converter 22, the automatic transmission 24, the propeller shaft 28, the differential gear 30, the drive shaft 32, etc. in this order.

[0031] The vehicle 10 is equipped with a MOP 58 which is a mechanical oil pump, an EOP 60 which is an electric oil pump, a pump motor 62, etc. The MOP 58 is connected to the pump impeller 22a and is driven to rotate by a power source SP to discharge hydraulic oil OIL used in the power transmission device 16. The pump motor 62 is a motor dedicated to the EOP 60 for driving the EOP 60 to rotate. The EOP 60 is driven to rotate by the pump motor 62 to discharge hydraulic oil OIL. The hydraulic oil OIL discharged by the MOP 58 and the EOP 60 is supplied to a hydraulic control circuit 56. The hydraulic control circuit 56 supplies a CB hydraulic pressure PRcb, a K0 hydraulic pressure PRk0, etc., which are adjusted based on the hydraulic oil OIL discharged by the MOP 58 and / or the EOP 60.

[0032] The vehicle 10 is equipped with a wheel brake device 64. The wheel brake device 64 includes a brake master cylinder and a cylinder actuator (not shown) that generate brake hydraulic pressure. Each of the wheels, including the drive wheels 14 and the non-drive wheels (not shown), is equipped with a wheel brake 66. If the vehicle 10 is an all-wheel drive vehicle, the non-drive wheels are drive wheels. The wheel brake device 64 is a brake device that applies wheel braking torque, which is a braking torque generated by the wheel brakes 66, to the wheels in accordance with a command from an electronic control device 90 (described later). The wheel brake device 64 supplies brake hydraulic pressure to wheel cylinders (not shown) provided in each wheel brake 66 in response to, for example, the driver's depression of the brake pedal. In the wheel brake device 64, under normal conditions, master cylinder hydraulic pressure generated by the brake master cylinder and corresponding to the brake operation amount Bra is supplied to the wheel cylinders as brake hydraulic pressure. On the other hand, in the wheel brake device 64, for example, when the ABS function is activated, skid prevention control is activated, vehicle speed control is activated, automatic driving control is activated, automatic braking function is activated, regeneration control is activated, etc., in order to generate wheel braking torque, brake hydraulic pressure of a magnitude corresponding to the wheel braking torque required for each control is supplied to the wheel cylinder. The brake operation amount Bra is a signal that corresponds to the brake pedal depression force and indicates the magnitude of the brake pedal depression operation by the driver, i.e., the magnitude of the brake operation.

[0033] The vehicle 10 further includes an electronic control device 90 that includes a control device for the vehicle 10. The electronic control device 90 includes a so-called microcomputer equipped with, for example, a CPU, RAM, ROM, an input / output interface, etc., and the CPU executes various controls of the vehicle 10 by performing signal processing in accordance with programs stored in the ROM in advance while utilizing the temporary storage function of the RAM. The electronic control device 90 includes computers for engine control, electric motor control, clutch control, transmission control, etc. as necessary.

[0034] The electronic control device 90 receives various signals based on detected values from various sensors provided in the vehicle 10 (for example, an engine rotation speed sensor 70, a turbine rotation speed sensor 72, an output rotation speed sensor 74, an MG rotation speed sensor 76, an accelerator opening sensor 78, a throttle valve opening sensor 80, a brake sensor 82, a battery sensor 84, an oil temperature sensor 86, a shift position sensor 88, etc.) (for example, an engine rotation speed Ne which is the rotation speed of the engine 12, a turbine rotation speed Nt which is the same value as the AT input rotation speed Ni, an AT output rotation speed No corresponding to the vehicle speed V, an MG rotation speed Nm which is the rotation speed of the electric motor MG, a driver's access speed indicating the magnitude of the driver's acceleration operation, etc.). The following signals are supplied to the control circuit 56: accelerator opening θacc, which is the amount of throttle operation; throttle valve opening θth, which is the opening of the electronic throttle valve; brake-on signal Bon, which is a signal indicating that the brake pedal for operating the wheel brakes 66 is being operated by the driver; brake operation amount Bra; battery temperature THbat, which is the temperature of the battery 54; battery charge / discharge current Ibat, which is the charge / discharge current of the battery 54; battery voltage Vbat, which is the voltage of the battery 54; hydraulic oil temperature THoil, which is the temperature of the hydraulic oil OIL in the hydraulic control circuit 56; and operating position (=operating position) POSop, which indicates the position to which a shift lever 68 provided on the vehicle 10 has been operated.

[0035] The electronic control device 90 calculates the battery charge amount SOC [%] based on, for example, the battery charge / discharge current Ibat and the battery voltage Vbat. The battery charge amount SOC is the charge amount of the battery 54 and is a value indicating the state of charge of the battery 54, i.e., a state of charge value. The electronic control device 90 calculates the chargeable power Win [W] and dischargeable power Wout [W] of the battery 54 based on, for example, the battery temperature THbat and the battery charge amount SOC. The chargeable power Win of the battery 54 is the maximum power that can be input, which defines the limit on the input power of the battery 54, and indicates the input limit, i.e., the charge limit, of the battery 54. The dischargeable power Wout of the battery 54 is the maximum power that can be output, which defines the limit on the output power of the battery 54, and indicates the output limit, i.e., the discharge limit, of the battery 54.

[0036] The shift lever 68 is a shift operation member that is operated by the driver to one of a plurality of operation positions POSop. The operation position POSop is a signal that indicates the state of selecting a shift position (=shift position) of the automatic transmission 24. The operation position POSop includes, for example, P, R, N, and D operation positions that respectively correspond to the P, R, N, and D positions that are the plurality of shift positions of the automatic transmission 24. The shift position of the automatic transmission 24 indicates the power transmission state in the automatic transmission 24.

[0037] The P operating position is a parking operating position for selecting a parking position (=P position) that is a parking position of the automatic transmission 24. The P position of the automatic transmission 24 is a shift position of the automatic transmission 24 in which the automatic transmission 24 is in a neutral state and rotation of the transmission output shaft 26 is mechanically prevented. The neutral state of the automatic transmission 24 is a state in which the automatic transmission 24 is unable to transmit power, which is achieved, for example, by disengaging all of the engagement devices CB and cutting off power transmission in the automatic transmission 24. The state in which rotation of the transmission output shaft 26 is mechanically prevented is a parking lock state in which the transmission output shaft 26 is fixed so as not to rotate by a well-known parking lock mechanism provided in the vehicle 10. The R operating position is a reverse driving operating position for selecting a reverse driving position (=R position) that is a reverse driving position of the automatic transmission 24. The R position of the automatic transmission 24 is a shift position of the automatic transmission 24 that enables the vehicle 10 to travel in reverse. In other words, the R position of the automatic transmission 24 represents a power transmission state of the automatic transmission 24 in which a reverse driving gear, among a plurality of gears, is formed that enables the vehicle 10 to travel in reverse. The N operation position is a neutral operation position that selects the neutral position (=N position) that is the neutral position of the automatic transmission 24. The N position of the automatic transmission 24 is a shift position of the automatic transmission 24 in which the automatic transmission 24 is in a neutral state. The D operation position is a forward driving operation position that selects the forward driving position (=D position) that is the forward driving position of the automatic transmission 24. The D position of the automatic transmission 24 is a shift position of the automatic transmission 24 that executes automatic shift control of the automatic transmission 24 to enable the vehicle 10 to travel in forward. That is, the D position of the automatic transmission 24 represents the power transmission state of the automatic transmission 24 in which a forward driving gear, among the multiple gears, that enables the vehicle 10 to drive forward is formed.

[0038] The electronic control device 90 outputs various command signals (for example, an engine control command signal Se for controlling the engine 12, an MG control command signal Sm for controlling the electric motor MG, a CB hydraulic control command signal Scb for controlling the engagement device CB, a K0 hydraulic control command signal Sk0 for controlling the K0 clutch 20, an LU hydraulic control command signal Slu for controlling the LU clutch 40, an EOP control command signal Seop for controlling the EOP 60, a brake control command signal Sbra for controlling the wheel braking torque, etc.) to each device provided in the vehicle 10 (for example, the engine control device 50, the inverter 52, the hydraulic control circuit 56, the pump motor 62, the wheel brake device 64, etc.).

[0039] In order to realize various controls in the vehicle 10, the electronic control device 90 is equipped with a power source control means, i.e., a power source control unit 92, a clutch control means, i.e., a clutch control unit 94, a transmission control means, i.e., a transmission control unit 96, and a predetermined mode setting means, i.e., a predetermined mode setting unit 98.

[0040] The power source control unit 92 includes a function as engine control means, i.e., engine control unit 92a, that controls the operation of the engine 12, and a function as electric motor control means, i.e., electric motor control unit 92b, that controls the operation of the electric motor MG via the inverter 52, and is a hybrid control means, i.e., a hybrid control unit, that performs hybrid drive control using the engine 12 and the electric motor MG using these control functions.

[0041] The power source control unit 92 calculates the amount of driving demanded by the driver for the vehicle 10, for example, by applying the accelerator opening θacc and the vehicle speed V to a driving demand map. The driving demand map is a relationship that is experimentally or design-based and stored in advance, i.e., a predetermined relationship. The driving demand is, for example, the required driving torque Trdem at the drive wheels 14. In other words, the required driving torque Trdem [Nm] is the required driving power Prdem [W] at the current vehicle speed V. The driving demand may also be the required driving force Frdem [N] at the drive wheels 14 or the required AT output torque at the transmission output shaft 26. In calculating the driving demand, the AT output rotation speed No may be used instead of the vehicle speed V. The power source control unit 92 outputs an engine control command signal Se for controlling the engine 12 and an MG control command signal Sm for controlling the electric motor MG so as to realize the required driving power Prdem, taking into account transmission loss, auxiliary load, the gear ratio γat of the automatic transmission 24, etc.

[0042] When the required drive torque Trdem can be satisfied by the output of the electric motor MG alone, the power source control unit 92 establishes the motor drive mode, i.e., the BEV drive mode, as the drive mode for driving the vehicle 10. The BEV drive mode is an electric drive mode that enables motor driving, i.e., electric driving (=BEV driving), in which the vehicle runs using only the electric motor MG as the power source SP with the K0 clutch 20 disengaged and the engine 12 stopped. On the other hand, when the required drive torque Trdem cannot be satisfied without using at least the output of the engine 12, the power source control unit 92 establishes the engine drive mode, i.e., the HEV drive mode, as the drive mode. The HEV drive mode is a hybrid drive mode that enables engine driving, i.e., hybrid driving (=HEV driving), in which the vehicle runs using at least the engine 12 as the power source SP with the K0 clutch 20 engaged. On the other hand, even if the required drive torque Trdem can be met by the output of the electric motor MG alone, the power source control unit 92 establishes the HEV drive mode as the drive mode when it is necessary to charge the battery 54 or when it is necessary to warm up the engine 12, etc.

[0043] The power source control unit 92 performs control to maintain the battery state of charge SOC at an appropriate value. Specifically, the battery 54 repeatedly discharges due to power supply during acceleration, etc., and charges due to regenerative braking during deceleration, etc. Discharge due to power supply during acceleration, etc., is achieved by discharging from the battery 54 due to the power running of the electric motor MG. Charging due to regenerative braking during deceleration, etc., is achieved by charging the battery 54 using power generated by the electric motor MG. The power source control unit 92 performs control to maintain the battery state of charge SOC within a predetermined control range RNGsoc by repeatedly discharging and charging the battery 54, i.e., charge maintenance control. The predetermined control range RNGsoc is, for example, a predetermined appropriate range of the battery state of charge SOC for maintaining the performance of the battery 54.

[0044] The limiting upper limit value SOClimu, which is the upper limit of the predetermined control range RNGsoc, is set in advance to a value that is lower by a predetermined amount A than the lower limit of the range of the battery charge amount SOC that falls within the overcharge range, so that the battery charge amount SOC does not fall within the overcharge range of the battery 54. The limiting lower limit value SOCliml, which is the lower limit of the predetermined control range RNGsoc, is set in advance to a value that is higher by a predetermined amount B than the upper limit of the range of the battery charge amount SOC that falls within the overdischarge range, so that the battery charge amount SOC does not fall within the overdischarge range of the battery 54. The overcharge range and overdischarge range of the battery 54 are set in advance as ranges of the battery charge amount SOC in which the battery 54 is likely to deteriorate, for example.

[0045] When the battery 54 needs to be charged, for example, when the electric motor MG is powered, or when the vehicle is coasting while decelerating and therefore regenerative braking torque, which is braking torque generated by regenerative braking, is not applied to the wheels, the electric motor MG cannot be charged by regenerative braking. If the electric motor MG cannot be charged by regenerative braking when the battery 54 needs to be charged, the power source control unit 92 charges the battery 54 by the electric motor MG using the power of the engine 12. At this time, the power source control unit 92 increases the engine power Pe, which is the power [W] of the engine 12 equivalent to the charging electric power [W] by the electric motor MG, and charges the battery 54 by the electric motor MG.

[0046] The power source control unit 92, particularly the engine control unit 92a, determines whether or not there is an engine start request, which is a request to start the engine 12 and switch the control state of the engine 12 from a stopped state to an operating state. For example, in the BEV drive mode, the engine control unit 92a determines whether or not there is an engine start request based on whether or not the required drive torque Trdem has increased beyond a range that can be covered by the output of the electric motor MG alone, whether or not the engine 12 and the like need to be warmed up, or whether or not the battery 54 needs to be charged.

[0047] When the engine control unit 92a determines that there is an engine start request, the clutch control unit 94 controls the K0 clutch 20 to execute start control of the engine 12. For example, the clutch control unit 94 outputs a K0 hydraulic control command signal Sk0 to the hydraulic control circuit 56 to control the K0 clutch 20 from a released state toward an engaged state so as to obtain a K0 torque Tk0 for transmitting the cranking torque Tcr to the engine 12. The cranking torque Tcr is a predetermined torque required for cranking the engine 12 to increase the engine rotation speed Ne.

[0048] When the power source control unit 92 determines that there is an engine start request, it controls the engine 12 and the electric motor MG to execute start control of the engine 12. For example, the electric motor control unit 92b outputs an MG control command signal Sm to the inverter 52 in response to the clutch control unit 94 switching the K0 clutch 20 to the engaged state, that is, in conjunction with the cranking of the engine 12 by the K0 clutch 20. Furthermore, the engine control unit 92a outputs an engine control command signal Se to the engine control device 50 in conjunction with the cranking of the engine 12 in order to start fuel supply, engine ignition, and the like.

[0049] The power source control unit 92, particularly the engine control unit 92a, determines whether there is an engine stop request, which is a request to stop the engine 12 by switching the control state of the engine 12 from a running state to a stopped state. For example, in the HEV drive mode, the engine control unit 92a determines whether there is an engine stop request based on whether the required drive torque Trdem is within a range that can be covered by the output of the electric motor MG alone, whether warming up the engine 12 and the like is unnecessary, whether charging the battery 54 is unnecessary, and so on.

[0050] When the engine control unit 92a determines that there is an engine stop request, it outputs an engine control command signal Se to the engine control device 50 to gradually reduce the engine torque Te. When the engine control unit 92a determines that there is an engine stop request, the clutch control unit 94 outputs a K0 hydraulic control command signal Sk0 to the hydraulic control circuit 56 to control the K0 clutch 20 from the engaged state toward the released state after the engine torque Te has been gradually reduced by the engine control unit 92a. After the clutch control unit 94 switches the K0 clutch 20 to the released state, the engine control unit 92a outputs an engine control command signal Se to the engine control device 50 to perform a fuel cut to stop the supply of fuel to the engine 12.

[0051] The transmission control unit 96 determines whether to shift the automatic transmission 24 using, for example, a shift map, which is a predetermined relationship, and outputs a CB hydraulic control command signal Sbc to the hydraulic control circuit 56 as needed, i.e., depending on the result of the shift determination. In controlling the shift of the automatic transmission 24, the transmission control unit 96 performs shifting of the automatic transmission 24, for example, by switching a disengaging engagement device among the engagement devices CB to a disengaged state and switching an engaging engagement device among the engagement devices CB to an engaged state. The shift map is a predetermined relationship having shift lines on a two-dimensional coordinate system using, for example, vehicle speed V and required drive torque Trdem as variables, for determining whether to shift the automatic transmission 24. In the shift map, the AT output rotation speed No or the like may be used instead of the vehicle speed V, and the required drive force Frdem, accelerator opening θacc, throttle valve opening θth, or the like may be used instead of the required drive torque Trdem.

[0052] The predetermined mode setting unit 98 establishes a maintenance mode when a special operation is performed on the vehicle 10. The maintenance mode is a driving mode that is established when, for example, special driving, such as measurement, evaluation, or testing, that differs from normal driving, is performed. Specifically, the maintenance mode is a predetermined mode that is established when the running resistance R / L (= road load) of the vehicle 10 is measured and / or when the measured running resistance R / L is set when measuring a predetermined performance of the vehicle 10. The measurement of the predetermined performance of the vehicle 10 is a certification test that performs mode driving using a known chassis dynamometer, such as for fuel economy, energy efficiency, or exhaust gas evaluation. The special operation for establishing the maintenance mode is an operation that is not performed in normal driving of the vehicle 10 by the driver, such as a series of operations that involves operating the accelerator multiple times in the P operating position followed by operating the accelerator multiple times in the N operating position, repeated a predetermined number of times.

[0053] The procedure for measuring running resistance R / L will be described using a coasting method as an example. For example, when running steadily on a flat road, running resistance R / L is the sum of air resistance and rolling resistance, and varies depending on the vehicle speed V. In the coasting method, the time required for deceleration, i.e., deceleration time, is measured for each of a plurality of vehicle speeds V, and is used to represent the running resistance R / L. Specifically, the vehicle 10 is set to a maintenance mode using a special operation. Next, the vehicle 10 is warmed up. During this warm-up, the vehicle 10 is run at a steady speed for 30 minutes, for example, at a vehicle speed V of 80 km / h. After that, the vehicle 10 is accelerated to approximately 150 km / h, and coasting is initiated with the automatic transmission 24 in the N position and the accelerator released. When measuring running resistance R / L using the coasting method, the engine 12 is in operation, and the K0 clutch 20 is engaged. During this coasting, the brakes are off, and no wheel braking torque or regenerative braking torque is applied in response to braking. The deceleration time is measured from +5 km / h to -5 km / h in 10 km / h increments, for example, from 120 km / h to 10 km / h. For example, in the case of 120 km / h, the deceleration time is measured from 125 km / h to 115 km / h. This series of measurements is repeated multiple times to confirm the reproducibility of the deceleration time at each vehicle speed range. In the certification test, which involves mode running on a chassis dynamometer, the deceleration time at each vehicle speed V is set on the chassis dynamometer as a value representing the running resistance R / L of the certified vehicle. In this way, the running resistance R / L is measured and / or the running resistance R / L is set during the certification test when the vehicle 10 is in the maintenance mode, the automatic transmission 24 is in the N position, and the vehicle 10 is coasting with the accelerator off. In this embodiment, this case is expressed as the vehicle 10 being in the maintenance mode and coasting in the N position.

[0054] In order to accurately measure or set the running resistance R / L, it is desirable to eliminate as many disturbances as possible while the vehicle 10 is coasting. When the vehicle 10 is in the maintenance mode, the electronic control device 90 stops functions of the vehicle 10 that cause disturbances to the coasting of the vehicle 10. Functions of the vehicle 10 that cause disturbances to the coasting of the vehicle 10 include, for example, an ABS function, a skid prevention function, and various functions that use signals from sensors such as proximity sensors that detect obstacles around the vehicle 10.

[0055] When measuring running resistance R / L using the coasting method, in order to measure running resistance R / L accurately and reproducibly, it is necessary to suppress fluctuations in the rotational speed of the drive shaft 32, i.e., fluctuations in the drive torque Tr, during coasting in the N position. Furthermore, in the certification test, it is necessary to correctly set the running resistance R / L of the certified vehicle on the chassis dynamometer.

[0056] Incidentally, when there is an engine start request or an engine stop request, torque fluctuations accompanying the engine start or stop are transmitted to the transmission input shaft 38. Alternatively, when the battery 54 is charged by the electric motor MG using power from the engine 12, if the balance between the increase in engine power Pe and the charging power of the electric motor MG is lost, the torque fluctuations accompanying this are transmitted to the transmission input shaft 38. On the other hand, even when the automatic transmission 24 is in the N position, power transmission can occur due to drag of the engagement device CB via the hydraulic oil OIL inside the automatic transmission 24. Therefore, the torque fluctuations transmitted to the transmission input shaft 38 may lead to torque fluctuations of the transmission output shaft 26 and ultimately fluctuations in the drive torque Tr. In this case, when the engine 12 is started or stopped or when the electric motor MG is charging, the drive shaft 32 may not be in a completely driven state due to only the driven torque input from the drive wheels 14, which may cause variations in the change in vehicle speed V during coasting in the N position, making it impossible to properly measure or set the running resistance R / L.

[0057] Therefore, the electronic control device 90 further includes an operation prohibition means, i.e., an operation prohibition unit 99, which prohibits intermittent engine operation that switches the engine 12 between an operating state and a stopped state when the vehicle 10 is in maintenance mode and coasting in N position, and prohibits charging of the battery 54 by the electric motor MG using the power of the engine 12.

[0058] When the vehicle 10 is in the maintenance mode and coasting in the N position, the engine 12 is basically in an operating state with the K0 clutch 20 engaged. Therefore, prohibiting intermittent operation of the engine by the operation prohibition unit 99 means that if the engine 12 is in an operating state, that state is maintained, and if the engine 12 is in a stopped state, the engine 12 is started and maintained in an operating state, that is, prohibiting the engine 12 from being stopped.

[0059] The charging operation by the electric motor MG using the power of the engine 12 is basically performed to maintain the battery state of charge SOC within a predetermined control range RNGsoc. Prohibiting the charging operation by the electric motor MG means prohibiting the charging operation by the electric motor MG during the charge amount maintenance control.

[0060] If the battery 54 is not charged, not only will it be impossible to maintain the battery charge state of charge SOC within the predetermined control range RNGsoc, but the battery charge state of charge SOC may further decrease and enter the over-discharge region of the battery 54, which may accelerate deterioration of the battery 54. If the battery charge state of charge SOC enters the over-discharge region of the battery 54, it is desirable to prioritize protection of the battery 54 by forcibly charging the battery 54 without prohibiting charging operation by the electric motor MG, even when the vehicle 10 is in the maintenance mode and coasting in the N position.

[0061] When the battery voltage Vbat is in a predetermined low voltage range RNGbvl where forced charging is required, the operation prohibition unit 99 does not prohibit charging operation by the electric motor MG, but allows charging operation by the electric motor MG using the power of the engine 12. The predetermined low voltage range RNGbvl is, for example, a predetermined battery voltage Vbat range for determining whether the battery 54 is in an over-discharge region where the battery charge state SOC is lower than the limit lower limit value SOCliml.

[0062] Alternatively, when measuring running resistance R / L using the coasting method, the deceleration time is measured from a vehicle speed V of, for example, 120 km / h to 10 km / h, that is, from a vehicle speed range of 15 km / h to 5 km / h. In other words, running resistance R / L is not measured at low vehicle speeds of less than 5 km / h, including when the vehicle is stopped. If running resistance R / L is not measured, there is no need to prohibit charging operation by electric motor MG, and thus charging operation by electric motor MG is permitted, prioritizing protection of battery 54.

[0063] When the vehicle speed V is in a predetermined low vehicle speed range RNGvvl including zero that is not used for measuring the running resistance R / L, the operation prohibition unit 99 does not prohibit the charging operation by the electric motor MG, but permits the charging operation by the electric motor MG using the power of the engine 12. The predetermined low vehicle speed range RNGvvl is, for example, a low vehicle speed range below a predetermined vehicle speed Vf that is predetermined as the lower limit value of the range of vehicle speed V in which the running resistance R / L is measured.

[0064] Specifically, the operation prohibition unit 99 determines whether the vehicle 10 is in the maintenance mode and coasting in the N position.

[0065] When the operation prohibition unit 99 determines that the vehicle 10 is in the maintenance mode and coasting in the N position, it determines whether the vehicle speed V is equal to or greater than a predetermined vehicle speed Vf. When the operation prohibition unit 99 determines that the vehicle 10 is in the maintenance mode and coasting in the N position, it determines whether the battery voltage Vbat exceeds a predetermined voltage Vbatf, which is the upper limit of the predetermined low voltage range RNGbvl.

[0066] When the operation prohibition unit 99 determines that the vehicle 10 is in maintenance mode and coasting in N position, it prohibits intermittent engine operation regardless of whether the vehicle speed V is equal to or greater than a predetermined vehicle speed Vf, and regardless of whether the battery voltage Vbat exceeds a predetermined voltage Vbatf.

[0067] When the operation prohibition unit 99 determines that the vehicle 10 is in the maintenance mode and coasting in the N position, and if it determines that the vehicle speed V is equal to or greater than the predetermined vehicle speed Vf and that the battery voltage Vbat is greater than the predetermined voltage Vbatf, it prohibits the electric motor MG from using the power of the engine 12 to charge the battery 54. On the other hand, when it determines that the vehicle 10 is in the maintenance mode and coasting in the N position, and if it determines that the vehicle speed V is less than the predetermined vehicle speed Vf or if it determines that the battery voltage Vbat is equal to or less than the predetermined voltage Vbatf, it does not prohibit the electric motor MG from using the power of the engine 12 to charge the battery 54.

[0068] 2 is a flowchart illustrating the main control operations of the electronic control device 90, specifically, the control operations for appropriately measuring or setting the running resistance R / L, and is executed repeatedly, for example. This flowchart is useful when, for example, measuring or setting the running resistance R / L.

[0069] In FIG. 2, each step in the flowchart corresponds to the function of the operation prohibition unit 99. In step (hereinafter, "step" will be omitted) S10, it is determined whether the vehicle 10 is in the maintenance mode and coasting in the N position. If the determination in S10 is negative, this routine is terminated. If the determination in S10 is positive, it is determined in S20 whether the vehicle speed V is equal to or greater than a predetermined vehicle speed Vf. If the determination in S20 is positive, it is determined in S30 whether the battery voltage Vbat exceeds a predetermined voltage Vbatf. If the determination in S30 is positive, charging operation by the electric motor MG is prohibited in S40. If the determination in S20 is negative, or if the determination in S30 is negative, or following S40, intermittent engine operation is prohibited in S50.

[0070] As described above, according to this embodiment, when the vehicle 10 is in the maintenance mode and coasting in the N position, intermittent engine operation is prohibited and charging operation by the electric motor MG using the power of the engine 12 is prohibited. Therefore, even in the vehicle 10 equipped with the automatic transmission 24 in which power transmission can occur due to drag of the engagement device CB even in the N position, the variation in the change in vehicle speed V during coasting caused by the torque fluctuations associated with intermittent engine operation and charging operation propagating to the drive torque Tr is suppressed. Therefore, the running resistance R / L can be appropriately measured or set.

[0071] Furthermore, according to this embodiment, when the vehicle speed V is in a predetermined low vehicle speed range RNGvvl including zero, which is not used for measuring the running resistance R / L, charging operation by the electric motor MG is permitted, thereby suppressing deterioration of the battery 54 due to over-discharge.

[0072] Furthermore, according to this embodiment, when the battery voltage Vbat is in a predetermined low voltage range RNGbvl where forced charging is required, charging operation by the electric motor MG is permitted, thereby suppressing deterioration of the battery 54 due to over-discharge.

[0073] Furthermore, according to this embodiment, prohibiting charging operation by the electric motor MG means prohibiting charging operation by the electric motor MG in charge amount maintenance control, and the predetermined low voltage range RNGbvl is the battery voltage Vbat range for determining whether the battery 54 is in the over-discharge region where the battery charge amount SOC is lower than the limit lower limit value SOCliml, so that deterioration of the battery 54 due to over-discharge can be appropriately suppressed.

[0074] Furthermore, according to this embodiment, prohibiting intermittent engine operation means prohibiting the engine 12 from being stopped, so that the operating state of the engine 12 is maintained appropriately when the running resistance R / L is measured or set.

[0075] Furthermore, according to this embodiment, when the vehicle 10 is in maintenance mode, functions of the vehicle 10 that cause disturbances to the coasting of the vehicle 10 are stopped, so that the running resistance R / L can be measured or set with high accuracy.

[0076] Furthermore, according to this embodiment, it is possible to reduce the number of steps required to measure the running resistance R / L while protecting the battery 54.

[0077] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the present invention can also be applied to other embodiments.

[0078] For example, in the above-described embodiment, the K0 clutch 20 is provided in the power transmission path between the engine 12 and the electric motor MG, but the K0 clutch 20 does not necessarily have to be provided.

[0079] Furthermore, in the above-described embodiment, a planetary gear automatic transmission was exemplified as the automatic transmission 24, but this is not limiting. For example, the automatic transmission 24 may be a known belt-type continuously variable transmission. When the automatic transmission 24 is a belt-type continuously variable transmission, the forward clutch and reverse brake of a known forward / reverse switching device provided together with the belt-type continuously variable transmission correspond to the wet engagement devices. In short, the present invention can be applied to any vehicle equipped with a power source including an engine and an electric motor, and an automatic transmission that transmits power from the power source by engaging wet engagement devices provided in a power transmission path between the power source and the drive wheels.

[0080] In the above-described embodiment, the torque converter 22 is used as the fluid transmission device, but the present invention is not limited to this. For example, instead of the torque converter 22, another fluid transmission device without torque amplification, such as a fluid coupling, may be used as the fluid transmission device. Alternatively, the fluid transmission device does not necessarily have to be provided, and may be replaced with, for example, a wet clutch for starting.

[0081] It should be noted that the above is merely one embodiment, and the present invention can be embodied in various forms with various modifications and improvements based on the knowledge of those skilled in the art. [Explanation of symbols]

[0082] 10: Vehicle 12: Engine 14: Drive wheel 24: Automatic transmission 54: Battery (power storage device) 90: Electronic control device (control device) CB: Engagement device (wet engagement device) MG: Electric motor SP: Power source

Claims

1. A control device for a vehicle including a power source including an engine and an electric motor, an automatic transmission that transmits power from the power source by engaging a wet engagement device provided in a power transmission path between the power source and drive wheels, and an electricity storage device that supplies and receives electric power to the electric motor, The control device is set to a predetermined mode that is established when the vehicle's running resistance is measured or when the measured running resistance is set when measuring a predetermined performance of the vehicle, and in addition, when the automatic transmission is in a neutral position in which power cannot be transmitted and the vehicle is in a coasting state with the accelerator off, the control device prohibits intermittent engine operation that switches the engine between a running state and a stopped state, and prohibits charging of the storage device by the electric motor using power from the engine.

2. 2. The vehicle control device according to claim 1, wherein the control device permits the charging operation when the vehicle is in the predetermined mode, the automatic transmission is in the neutral position, and the vehicle is in the coasting state, and the vehicle speed is within a predetermined low vehicle speed range including zero, which is not used for measuring the running resistance.

3. 3. The vehicle control device according to claim 1, wherein the control device permits the charging operation when the voltage of the power storage device is in a predetermined low voltage range requiring forced charging, even when the vehicle is in the predetermined mode, the automatic transmission is in the neutral position, and the vehicle is in the coasting state.

4. prohibiting the charging operation means prohibiting the charging operation by the electric motor in a control that maintains the charge amount of the power storage device within a predetermined control range by repeatedly discharging and charging the power storage device, 4. The vehicle control device according to claim 3, wherein the predetermined low voltage range is a voltage range of the storage device for determining whether the charge amount is in an over-discharge range of the storage device that is lower than a lower limit value of the predetermined control range.

5. 5. The vehicle control device according to claim 1, wherein prohibiting the intermittent operation of the engine means prohibiting the engine from being stopped.

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