JP2006141127A - Controller for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controller for vehicle capable of obtaining a proper braking state by a braking force by a conventional wheel brake in a braking time during vehicle decelerated traveling, in a vehicle equipped with a power transmission for transmitting engine output to driving wheels. <P>SOLUTION: During a low speed decelerated traveling of a vehicle and a vehicle braking operation by a wheel braking device 80, a regenerative controlling means 112 is used to execute regenerative control by a motor generator MG so that a driving wheel torque T<SB>W</SB>other than the braking torque in the driving wheels 52 becomes lower than a prescribed driving wheel torque T<SB>W</SB>'. Thereby, part of the engine output is converted into electric energy, suppressing the engine torque T<SB>E</SB>transmitted to the driving wheels 52. Even if the transmission ratio of the first accelerating gear step of an automatic transmission 16 is made larger than a conventional transmission, the driving force generated in the driving wheels 52 during the low speed decelerated traveling is suppressed to obtain a proper braking state with the braking force by the conventional wheel braking device 80. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle control device including a power transmission device configured to transmit power of a driving force source to driving wheels, and more particularly, to driving wheels during low-speed deceleration traveling of a vehicle and a vehicle braking operation by a driver. The present invention relates to a technology for suppressing power transmitted to the vehicle.

  For example, a vehicle including an engine and a power transmission device that transmits the output of the engine to drive wheels is known, such as the vehicle described in Patent Document 1. Today, the transmissions that make up the power transmission device are being multistaged and widening the gear ratio to achieve both acceleration performance and fuel efficiency. Along with this, the gear ratio of the starting gear, for example, the lowest speed gear, is further increased (low gear).

  Further, in the vehicle described in Patent Document 3, the output of the engine is transmitted to the drive wheels via a fluid transmission device such as a torque converter, and the engine rotation speed is maintained at, for example, an idle rotation speed even when the vehicle is stopped. Is done. In this vehicle stop state, even when the accelerator is off, so-called creep torque (creep force), that is, drive torque (drive force) is generated by idle rotation of the engine, and braking such as wheel brakes provided on the wheels. In a state where the braking force by the device is released, the vehicle is started slowly.

  In such a vehicle described in Patent Document 3, when the speed ratio of the lowest speed side gear stage is further increased as described in the description of Patent Document 1, the driving wheel is applied during braking in vehicle deceleration traveling just before the vehicle stops. Since the torque (creep torque) is further increased, it is necessary to increase the braking torque by the wheel brake against the creep torque for decelerating and stopping the vehicle in a desired braking state.

US Patent Publication No. 2003 / 0127262A1 JP 2001-45608 A JP 2001-26221 A

  However, in general, the braking force by the wheel brake is such that the brake master cylinder hydraulic pressure (input hydraulic pressure) starts a predetermined operation in order to bring the braking force distribution of the front and rear wheels closer to the ideal distribution and to prevent the wheel lock of the rear wheels. A hydraulic pressure control valve (so-called proportioning (P)) that reduces the subsequent rear wheel side hydraulic pressure to the input hydraulic pressure (front wheel side hydraulic pressure) when the hydraulic pressure exceeds a point (constant hydraulic pressure, breakpoint hydraulic pressure) or higher. The braking force distribution of the front and rear wheels is controlled by a valve, a limiting (L) valve, etc.), and if the braking force of the driving wheel is exclusively increased, the braking operation balance may be difficult to control. Further, if the braking force of all the wheels is increased while maintaining the front-rear wheel distribution ratio, the braking force may become too large for the driven wheel, and it may be difficult to control the braking operation balance.

  The present invention has been made against the background of the above circumstances, and an object of the present invention is to reduce vehicle travel in a vehicle including an engine and a power transmission device that transmits the output of the engine to drive wheels. It is an object of the present invention to provide a vehicle control device that can obtain an appropriate braking state with a braking force by a conventional wheel brake during braking.

  The subject matter of the first invention for achieving the object includes (a) a driving force source, and a power transmission device provided in a power transmission path from the driving force source to the driving wheel and having an electric motor. A vehicle control device, wherein (b) the driving force of the driving wheel is less than a predetermined value than the braking force of the driving wheel based on the vehicle braking operation when the vehicle is driven at a low speed and the vehicle is braked by the driver. And regenerative control means for suppressing power transmitted to the drive wheels by executing regenerative control by the electric motor.

  According to this configuration, in the vehicle including the power transmission device that transmits the output of the driving force source to the driving wheel, the driving wheel based on the vehicle braking operation is performed when the vehicle is traveling at a low speed and when the driver performs the vehicle braking operation. Since the regenerative control by the regenerative control means executes the regenerative control by the electric motor so that the driving force of the driving wheel is less than the predetermined value rather than the braking force, the power transmitted to the driving wheel is suppressed. Even if the minimum speed-side transmission ratio of the transmission to be increased is larger than the conventional one, the driving force generated on the drive wheels during low-speed deceleration traveling at the minimum speed-side transmission ratio is suppressed, and the conventional braking force by the wheel brake is appropriate. A braking state is obtained.

  Here, preferably, in the invention according to claim 2, the driving force source is an engine, and the regeneration control unit is configured such that the rotational speed of the engine is higher than a normal idle rotational speed according to a vehicle state. Regenerative control is executed when controlled by. In this way, the engine output speed is increased by controlling the engine speed at a higher speed than the normal idle speed, for example, the first idle speed for warm-up according to the engine water temperature, according to the vehicle state. However, when the regeneration control is executed by the regeneration control means, the driving force generated in the drive wheels is suppressed, and an appropriate braking state can be obtained with the braking force by the conventional wheel brake.

  Preferably, the invention according to claim 3 further includes regeneration amount setting means for setting a regeneration amount at the time of regeneration control by the regeneration control means in accordance with the engine rotation speed, and the regeneration control means includes The regeneration control is executed so that the regeneration amount set by the regeneration amount setting means is obtained. In this way, since the regeneration amount is controlled by the regeneration amount setting means in accordance with the driving force that changes according to the engine rotation speed, that is, the creep force, the driving force generated on the drive wheels according to the engine rotation speed is suppressed. Thus, an appropriate braking state can be obtained by the braking force by the conventional wheel brake.

  Preferably, in the invention according to claim 4, the power transmission device includes an automatic transmission, and the regeneration control means is configured to perform the regeneration when the automatic transmission has a minimum speed side gear ratio. Control is executed. In this way, even if the minimum speed side gear ratio of the automatic transmission provided as the power transmission device is made larger than before, the regeneration control is executed by the regeneration control means, so that the low speed deceleration at the minimum speed side gear ratio is achieved. The driving force generated in the driving wheel during traveling is suppressed, and an appropriate braking state can be obtained with the braking force by the conventional wheel brake.

  Here, preferably, the vehicle control device of the present invention is applied to a vehicle including an electric motor between a driving force source and a driving wheel. The electric motor generates electric power for converting rotational motion into electric energy. It may have at least a function as a machine, and in addition, may have a function as an electric motor (motor generator) that converts electric energy into rotational motion.

  The present invention also provides an engine-driven vehicle having only the engine as a driving force source, a hybrid vehicle having both the engine and the electric motor as driving force sources, a vehicle having a prime mover other than the engine and the electric motor as driving force sources, or The present invention can be applied to various vehicles such as a vehicle including three or more prime movers.

  Further, the braking force on the wheel during the braking operation by the driver traveling at a reduced speed is controlled using a wheel brake provided on the wheel.

  Further, as the automatic transmission, a planetary gear type multi-stage transmission in which a gear stage is switched by selectively connecting rotating elements of a plurality of sets of planetary gear apparatuses by a hydraulic friction engagement device, as a power transmission member A belt-type continuously variable transmission in which a functioning transmission belt is wound around a pair of variable pulleys whose effective diameter is variable and the gear ratio is continuously changed steplessly, a pair of cones rotated around a common axis And a plurality of rollers capable of rotating at the center of rotation intersecting the shaft center are clamped between the pair of cones, and the crossing angle between the center of rotation of the roller and the shaft center is changed, thereby making the transmission ratio variable. The traction type continuously variable transmission includes a pair of transmission gears that are always meshed between two shafts, and one of the plurality of pairs of transmission gears is driven by a synchronous device driven by a hydraulic actuator. Alternatively it can be used as the synchronous meshing type parallel two-shaft type automatic transmission for a power transmission state.

  Further, the planetary gear type multi-stage transmission only needs to be able to achieve a plurality of gear stages alternatively, for example, forward 4 stages, forward 5 stages, forward 6 stages, forward 7 stages, forward 8 stages. Various multi-stage automatic transmissions such as can be used.

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

  FIG. 1 is a skeleton diagram illustrating the configuration of a vehicle power transmission device 8 to which the present invention is applied. In FIG. 1, for example, an output of an engine 10 as a driving force source for traveling constituted by an internal combustion engine is input to an automatic transmission 16 via a crankshaft 12 and a torque converter 14 as a fluid transmission device, and is automatically shifted. It is transmitted from the output shaft 46 of the machine 16 to the drive wheel 52 via the differential gear device 50 and the axle 51 (see FIG. 3). Thus, the power transmission path is until the output of the engine 10 is transmitted to the drive wheels 52, and the power transmission path includes the torque converter 14, the automatic transmission 16, the differential gear device 50, and the like. Consists of. Further, an electric motor as a rotating machine and a motor generator MG functioning as a generator are operatively connected to the output shaft 46.

  The torque converter 14 includes a pump impeller 20 connected to the crankshaft 12, a turbine impeller 24 connected to the input shaft 22 of the automatic transmission 16, and the pump impeller 20 and the turbine impeller 24. A lockup clutch 26 for direct connection and a stator impeller 30 that is prevented from rotating in one direction by a one-way clutch 28 are provided. The lock-up clutch 26 is a hydraulic friction clutch that is frictionally engaged by a differential pressure ΔP between the hydraulic pressure in the engagement-side oil chamber 25 and the hydraulic pressure in the release-side oil chamber 27, and is fully engaged. Thus, the pump impeller 20 and the turbine impeller 24 are rotated together.

  The automatic transmission 16 is a stepped transmission in which a plurality of gear stages are selectively established, that is, switched, and includes a first transmission unit 32 that switches between two stages of high and low, a reverse gear stage, and four forward stages. And a second transmission unit 34 that can be switched. The first transmission unit 32 is supported by the sun gear S0, the ring gear R0, and the carrier K0 so as to be rotatable, and the planetary gear P0 includes a planetary gear P0 that is meshed with the sun gear S0 and the ring gear R0, and the sun gear S0 and the carrier. A clutch C0 and a one-way clutch F0 provided between K0 and a brake B0 provided between the sun gear S0 and the housing 38 are provided.

  The second transmission unit 34 is supported by the sun gear S1, the ring gear R1, and the carrier K1, and the first planetary gear unit 40 including the planetary gear P1 meshed with the sun gear S1 and the ring gear R1, and the sun gear S2. A second planetary gear unit 42 including a planetary gear P2 that is rotatably supported by the ring gear R2 and the carrier K2 and meshed with the sun gear S2 and the ring gear R2, and the sun gear S3, the ring gear R3, and the carrier K3 is rotatable. And a third planetary gear unit 44 comprising a planetary gear P3 supported and meshed with the sun gear S3 and the ring gear R3.

  The sun gear S1 and the sun gear S2 are integrally connected to each other, the ring gear R1, the carrier K2, and the carrier K3 are integrally connected, and the carrier K3 is connected to the output shaft 46. The ring gear R2 and the sun gear S3 are integrally connected to each other. A clutch C1 is provided between the ring gear R2 and sun gear S3 and the intermediate shaft 48, and a clutch C2 is provided between the sun gear S1 and sun gear S2 and the intermediate shaft 48. The housing 38 is provided with a band-type brake B1 for stopping the rotation of the sun gear S1 and the sun gear S2. A one-way clutch F1 and a brake B2 are provided in series between the sun gear S1 and sun gear S2 and the housing 38. The one-way clutch F <b> 1 is configured to be engaged when the sun gear S <b> 1 and the sun gear S <b> 2 try to reversely rotate in the direction opposite to the input shaft 22.

  A brake B3 is provided between the carrier K1 and the housing 38, and a brake B4 and a one-way clutch F2 are provided in parallel between the ring gear R3 and the housing 38. The one-way clutch F2 is configured to be engaged when the ring gear R3 attempts to rotate in the reverse direction.

In the automatic transmission 16 configured as described above, for example, according to the operation table shown in FIG. 2, the reverse speed and the gear ratio γ (the rotational speed N _IN of the input shaft 22 / the rotational speed N _OUT of the output shaft 46) are sequentially increased. The gear is switched to any one of the five forward speeds (1st to 5th). In FIG. 2, “◯” represents engagement, a blank represents release, “解放” represents engagement during engine braking, and “Δ” represents engagement not involved in power transmission. The clutches C0 to C2 and the brakes B0 to B4 are all hydraulic friction engagement devices that are engaged by a hydraulic actuator. As is apparent from FIG. 2, the so-called second gear stage and the third gear stage are achieved by releasing one of the brake B2 and the brake B3 and simultaneously engaging the other. This is a clutch-to-clutch shift.

FIG. 3 is a diagram illustrating a schematic configuration of the power transmission device 8 illustrated in FIG. 1. As shown in FIG. 3, the engine 10 is provided with an intake pipe 54 and an exhaust pipe 56, and the intake pipe 54 is provided with an electronic throttle valve 62 that is controlled to open and close by a throttle actuator 60. As shown in FIG. 8, the electronic throttle valve 62 is basically controlled to have a throttle valve opening θ _TH corresponding to the accelerator opening Acc representing the driver's required output amount.

  Each hydraulic friction engagement device and lock-up clutch 26 of the automatic transmission 16 includes at least an electric oil pump 64 and a mechanical oil pump 68 that is mechanically connected to the engine 10 and driven to rotate directly by the engine 10. It is controlled by a hydraulic control circuit 66 that uses the line pressure due to the hydraulic pressure generated from either of them as a source pressure. The line pressure is the maximum engagement pressure used to engage each hydraulic friction engagement device of the automatic transmission 16.

  The motor generator MG functions as a rotational drive device that rotationally drives the output shaft by its operation, and serves as a driving force source like the engine 10. In addition, the motor generator MG is driven to rotate by the output shaft 46 to generate electric power when the engine 10 is driven using the engine 10 as a driving force source or during deceleration. Then, a battery 70 as a power storage device that functions as a power source for the motor generator MG, that is, a battery 70, and a current supplied from the battery 70 to the motor generator MG are supplied to the battery 70 for charging. And an inverter 72 composed of, for example, a semiconductor switching element or the like for controlling the current to be supplied.

  The wheel brake device 80 supplies the brake hydraulic pressure to the wheel cylinder WC provided in the wheel brake in relation to the operation of the brake pedal 82 (see FIG. 4). In the wheel brake device 80, normally, a brake hydraulic pressure having a magnitude corresponding to the depression force of the brake pedal 82 generated in the master cylinder 84 is directly supplied to the wheel cylinder WC. For example, ABS control, traction control, VSC control, etc. Alternatively, at the time of hill hold control, a braking hydraulic pressure not corresponding to the pedal force is supplied to the wheel cylinder WC in order to hold or maintain the vehicle on a low μ road, start, turn, or stop the vehicle on the slope. It has become so.

  4A and 4B are diagrams for explaining the wheel brake device 80 in detail. FIG. 4A is a diagram schematically illustrating the configuration of the wheel brake device 80, and FIG. 4B is an actual view of the wheel brake device 80. It shows the front and rear wheel braking force distribution. In FIG. 4A, in the wheel brake device 80, in order to bring the braking force distribution of the front and rear wheels closer to the ideal distribution and to prevent the wheel lock of the rear wheel 52R, for example, the master cylinder hydraulic pressure is higher than a predetermined operation start point. A proportioning valve (P valve) 86 that reduces the subsequent rear wheel cylinder hydraulic pressure at a constant ratio with respect to the master cylinder hydraulic pressure (front wheel cylinder hydraulic pressure) is provided in the middle of the piping on the rear wheel 52R side. Is provided. As shown in FIG. 4B, the P valve 86 controls the braking force ratio between the front wheels 52F and the rear wheels 52R after the operation start point.

FIG. 5 is a block diagram illustrating a control system for the power transmission device 8 of the present embodiment, and illustrates a signal input to the electronic control device 90 and a signal output from the electronic control device 90. It is. For example, the electronic control unit 90 includes an accelerator opening signal indicating an accelerator opening Acc that is an operation amount of the accelerator pedal 88 detected by the accelerator opening sensor 89, and a throttle valve 62 detected by the throttle valve opening sensor 63. A throttle opening signal representing the opening degree θ _TH of the vehicle, a vehicle speed signal corresponding to the rotational speed N _OUT of the output shaft 46 detected by the output shaft rotational speed sensor (vehicle speed sensor) 47, that is, the vehicle speed V, and detected by the turbine rotational speed sensor 91. A signal indicating the turbine rotational speed _NT (= the rotational speed N _IN of the input shaft 22), a signal indicating the operation position P _SH of the shift lever 92 detected by the shift position sensor 98, and a signal detected by the foot brake switch 78. Brake pedal indicating that the foot brake (wheel brake) is operating (during stepping operation) 82 signal representing the operation (ON) B _ON of the charge and discharge current signal representative of the charge-discharge current I _CD battery detected by the current sensor 74, a battery temperature signal representative of the battery temperature T _BAT detected by the battery temperature sensor 76 Etc. are supplied. Alternatively, the electronic control unit 90, from the sensors and switches shown in FIG. 5, the signal, M (motor indicating signal indicating a signal indicative of the engine water temperature T _W, an engine rotational speed N _E is the rotational speed of the engine 10 Driving) mode command signal, air conditioner signal indicating the operation of the air conditioner, AT oil temperature signal indicating the hydraulic oil temperature T _OIL of the automatic transmission 16, a signal indicating the side brake operation, a catalyst temperature signal indicating the catalyst temperature, and a cam angle. Signal, snow mode setting signal indicating snow mode setting, acceleration signal indicating vehicle longitudinal acceleration, auto cruise signal indicating auto cruise driving, vehicle weight signal indicating vehicle weight, wheel speed signal indicating wheel speed of each wheel, signal representative of the rotational speed _{N MG} of the motor generator MG, a signal representing the generated current _{I GMG} of motor generator MG, the motor-generator MG Signals representing the dynamic current _{I AMG,} the signal representative of the battery voltage _{V BAT,} the charge capacity (charge amount, storage amount) of the battery 70 signal and representative of the SOC, are supplied.

In addition, the electronic control unit 90 operates a drive signal to the throttle actuator 60 for operating the opening degree θ _TH of the electronic throttle valve 62, a supercharging pressure adjustment signal for adjusting the supercharging pressure, and an electric air conditioner. A fuel for controlling the amount of fuel supplied to the engine 10 by the fuel injection device 58 for supplying or stopping the fuel to the electric air conditioner driving signal, the ignition signal for instructing the ignition timing of the engine 10, the intake pipe 54 or the cylinder of the engine 10 Supply amount signal, command signal for commanding operation of motor generator MG, shift position (operation position) _SH display signal for operating shift indicator, gear ratio display signal for displaying gear ratio, snow mode Snow mode display signal to display the wheel, ABS actuator to prevent wheel slippage during braking An ABS operation signal for operating the motor, an M mode display signal for indicating that the M mode is selected, and a shift solenoid for driving a shift valve in the hydraulic control circuit 66 for switching the gear stage of the automatic transmission 16 A signal for controlling the pressure, a command signal for driving the linear solenoid valve for controlling the line pressure, a drive command signal for operating the electric oil pump 64 which is a hydraulic pressure source of the hydraulic control circuit 66, and for driving the electric heater , A signal to the cruise control control computer, engagement / release of the lock-up clutch 26, a command signal for driving a linear solenoid valve for controlling the slip amount, and the like are output.

  The electronic control unit 90 includes a so-called microcomputer including a CPU, a ROM, a RAM, an input / output interface, and the like, and performs signal processing according to a program stored in advance in the ROM while using a temporary storage function of the RAM. Basically, for example, a shift control that automatically switches the gear stage of the automatic transmission 16, an output control of the engine 10, an engagement / release of the lockup clutch 26, or a lockup clutch control that executes slipping, etc. Execute.

  FIG. 6 shows an example of a shift operation device 94 as a shift range selection operation device provided with a shift lever 92. The shift operation device 94 is disposed beside the driver's seat, for example. The shift lever 92 is in a neutral state in which the power transmission path in the automatic transmission 16 is interrupted, and the parking position “P” corresponds to the P range for locking the output shaft 46 of the automatic transmission 16, for reverse travel. The reverse travel position “R” corresponding to the R range, the neutral position “N” corresponding to the N range for setting the neutral state (neutral state) where the power transmission path in the automatic transmission 16 is interrupted, and the automatic transmission mode The forward travel position “D” (highest speed range position) corresponding to the D range automatically shifted in the range from the first gear to the fifth gear, and the range from the first gear to the fourth gear. Is automatically shifted in the range of the fourth engine brake travel position “4” corresponding to the four ranges in which the engine brake is applied at each gear stage and the engine brake is applied at each gear stage, and in the range from the first speed gear stage to the third speed gear stage. Engineer at the stage The third engine brake travel position “3” corresponding to the three ranges on which the brake is applied, the two ranges in which the automatic braking is performed in the range from the first gear to the second gear and the engine brake is applied at each gear. The second engine brake travel position “2” corresponding to the first engine brake travel position “L” corresponding to the L range where the engine brake is applied and the first engine gear travel position is provided. ing.

  For example, the manual valve in the hydraulic control circuit 66 mechanically connected to the shift lever 92 is switched in conjunction with the operation of the shift lever 92 to each shift position, and is shown in the engagement operation table of FIG. The hydraulic control circuit 66 is mechanically switched so that the reverse gear stage “Rev”, neutral “N”, forward gear stage “D”, and the like are established. Further, the 1st to 5th shift stages shown in the engagement operation table of FIG. 2 at the “D” position are established by electrically switching the electromagnetic valve in the hydraulic control circuit 66.

  The shift positions shown in the “P” to “L” positions are the non-travel positions of the “P” position and the “N” position, for example, as shown in the engagement operation table of FIG. Non-drive for selecting switching to the power transmission cut-off state of the power transmission path by the clutch C1 and the clutch C2, which disables driving of the vehicle in which the power transmission path in the automatic transmission 16 is released. It is a position. Further, each of the travel positions from the “R” position and the “D” position to the “L” position is engaged with at least one of the first clutch C1 and the second clutch C2 as shown in the engagement operation table of FIG. It is also a drive position for selecting switching to the power transmission enabled state of the power transmission path by the clutch C1 and / or the clutch C2 that enables driving of the vehicle to which the power transmission path in the automatic transmission 16 is connected. .

FIG. 7 is a functional block diagram for explaining the main part of the control function provided in the electronic control unit 90. In FIG. 7, the engine output control means 100 controls the fuel injection by the fuel injection device 58 for the fuel injection control, and controls the ignition timing in addition to controlling the opening and closing of the electronic throttle valve 62 by the throttle actuator 60 for the throttle control. Therefore, output control of the engine 10 is executed by controlling ignition timing by an ignition device such as an igniter. For example, the engine output control means 100 drives the throttle actuator 60 based on the accelerator opening signal Acc from the pre-stored relationship shown in FIG. 8, and increases the throttle valve opening θ _TH as the accelerator opening Acc increases. Throttle control is executed so that

Further, the engine output control means 100 executes throttle control so as to control the idle rotation speed _NIDL at a target value when the vehicle is stopped or decelerated when the accelerator opening Acc is substantially zero (fully closed). For example, the engine output control means 100 determines the fast idle rotation speed that is set higher than the normal idle rotation speed N _IDL after warming up based on the engine water temperature signal _TW and the catalyst temperature signal from the relationship stored in advance. Throttle control is executed so that N _IDLF is obtained and that the normal idle speed N _IDL after the warm-up is obtained. In addition, engine output control means 100 executes throttle control so as to _obtain a predetermined idle-up rotation speed N _IDLU based on an idle-up request signal from an auxiliary load such as an air-conditioner signal indicating the operation of the air-conditioner. .

For example, as shown in FIG. 9, the shift control means 102 stores the relationship (shift) stored in two-dimensional coordinates using the throttle valve opening θ _TH and the vehicle speed V as parameters (variables) at the “D” position of the shift lever 92. (Diagram, map) is determined based on the actual throttle valve opening θ _TH and the vehicle speed V to determine the gear position to be shifted of the automatic transmission 16, that is, the shift determination from the current gear position to the gear position of the shift destination is executed. and, hydraulic friction engagement device according to the operation table shown in FIG. 2 for example so that the determined gear stage (clutches C, brakes B) hydraulic control circuit 66 a switching signal S _P output for switching the engagement state of Output to. The shift line in the shift diagram of FIG. 9 indicates whether or not the actual vehicle speed V crosses the horizontal line indicating the actual throttle valve opening degree θ _TH (%), that is, the value on which the shift on the shift line is to be executed ( is for determining whether exceeds the shift point vehicle speed) V _S, also will have been previously stored as a series of the values V _S that shift point vehicle speed. In the shift diagram of FIG. 9, the accelerator opening Acc (%) may be used instead of the throttle valve opening θ _TH (%).

By the way, when the output of the engine 10 is transmitted to the drive wheels 52 via a fluid transmission device such as the torque converter 14 as in the power transmission device 8 of the present embodiment, the vehicle is stopped or traveling at a low speed. and with also maintained the engine rotational speed N _E, for example, the idling speed N _IDL, the drive wheel torque T _W is caused by creep torque (creep force) to the driving wheels 52. This creep torque is increased as the gear stage of the automatic transmission 16 is the lower speed gear stage, that is, as the gear ratio is increased. Further, the idle rotational speed N _IDL is increased output of the first idling rotational speed N _idlf and idle-up rotational speed N _IDLU is controlled by the engine rotational speed N extent engine _{10 E} becomes higher, also the creep torque with it Increased.

  In particular, in the automatic transmission 16, in order to achieve both acceleration performance and fuel consumption performance, multi-stages and a wide range of gear ratios are promoted, and the minimum speed as the minimum speed side gear ratio is increased with the widening of the gear ratio. When the gear ratio of the side gear stage is further increased (lower gear), the creep torque on the drive wheels 52 is further increased when the vehicle is stopped or when the vehicle is decelerating, so that the vehicle is kept in a desired braking state. In order to decelerate and stop, it is necessary to further increase the braking torque by the wheel brake device 80 with respect to the creep torque. However, as described above, the braking torque distribution by the wheel brake device 80 is controlled by the P valve so that the front and rear wheel braking force distribution is controlled. If only the driving wheel 52 is increased, the braking balance becomes difficult to control, or the front and rear wheels are controlled. If the braking force of all the wheels is increased while maintaining the distribution ratio, the braking force may become too large for the driven wheel, and it may be difficult to control the braking balance.

Therefore, in this embodiment, even when the gear ratio of the lowest speed side gear stage is further increased as the automatic transmission 16 is multistage and the gear ratio is widened, the braking by the wheel brake device 80 is performed. Regenerative control by the motor generator MG is executed so that an appropriate braking state can be obtained without increasing the torque, that is, while maintaining the braking torque by the conventional wheel brake device 80 at the time of vehicle low-speed deceleration traveling. converting a portion of the output into electrical energy, by reducing the engine torque T _E that is transmitted to the drive wheels 52 to suppress the creep torque. The control operation will be described below.

The foot brake operation determination means 104 determines whether or not the foot brake is being depressed, for example, by whether or not a signal B _ON indicating the operation of the brake pedal 82 detected by the foot brake switch 78 is output. .

  The low-speed deceleration traveling determination means 106 determines whether or not the vehicle is traveling at a low vehicle speed, that is, at the first speed gear stage and is traveling at a reduced speed. Thus, it is determined whether or not the vehicle is decelerating while the accelerator is off, that is, coasting (coasting). The predetermined vehicle speed V 'is a value that is experimentally determined in advance as a low vehicle speed at which the automatic transmission 16 is controlled to be shifted to the lowest speed side gear stage, that is, the first gear stage by the shift control means 102.

The driving force determination means 108 determines that the foot brake is being depressed by the foot brake operation determination means 104 during braking during low-speed deceleration travel of the vehicle, and the low speed deceleration travel determination means 106 determines that the vehicle is at a low vehicle speed. and when it is determined that the deceleration traveling, the engine torque _'whether more than, for example, the drive wheel torque T _W is a predetermined drive wheel torque T _W' drive wheel torque T _W is a predetermined drive wheel torque T _W exceeds substantially the idle rotational speed N _IDL by the engine output control means 100 to a predetermined fast idle rotation speed N _{idlf 'and} a predetermined idle-up rotational speed N _IDLU' as a T _E is based on whether or not it is the control target value Judgment. In the present embodiment, the predetermined driving wheel torque T _W ′ is described later so that the driving wheel torque T _W (driving force) is less than a predetermined value rather than the braking torque (braking force) in the driving wheel 52 by the wheel brake device 80. This is a theoretical determination value for determining whether or not to perform regenerative control by the motor generator MG by the regenerative control means 112. The predetermined drive wheel torque T _W ′ is an upper limit drive wheel torque T _W that can provide an appropriate braking state during braking at low vehicle speed without configuring the wheel brake device 80 to increase the braking torque. There, the predetermined fast idle rotation speed N _{idlf 'and} a predetermined idle-up rotational speed N _IDLU' experimentally determined in advance as the engine rotational speed N _E of the upper limit suitable braking state is obtained at the time of braking when the vehicle slow deceleration It is a fixed value.

The regeneration amount setting means 110 determines that the driving wheel torque T _W is greater than or equal to a predetermined driving wheel torque T _W ′ when the driving force determination means 108 determines that the driving wheel torque T _W is greater than or equal to a predetermined driving wheel torque T _W ′ during braking during low-speed deceleration traveling of the vehicle. _W sets the regeneration carried amount of the regeneration control by the motor-generator MG that is performed by the regenerative control means 112 to be described later so as not to exceed a predetermined drive wheel torque T _{W '(the} amount of regeneration).

For example, FIG. 10 shows that the actual driving wheel torque T _W (driving force) is less than the predetermined driving wheel torque T _W ′ than the braking torque (braking force) in the driving wheels 52 by the wheel brake device 80. a regeneration carried amount of the regeneration control by the rotational speed N _E and the regenerative control means 112 and is stored previously obtained experimentally relationship (map), the regeneration carried amount extent that the engine rotational speed N _E is higher increase It is set to be. The regeneration amount setting means 110 determines a regeneration carried amount based on the engine rotational speed N _E from the relationship shown in FIG. 10. Further, as it is apparent from FIG. 10, the regeneration carried amount is the engine speed N _E to exceed the predetermined fast idle rotation speed N _{idlf 'or} a predetermined idle-up rotational speed N _IDLU' is zero. That regeneration control by the regeneration control means 112 is the engine speed N _E to exceed the predetermined fast idle rotation speed N _{idlf 'or} a predetermined idle-up rotational speed N _IDLU' is not executed.

The regeneration control unit 112 sets the regeneration amount when the driving force determination unit 108 determines that the driving wheel torque _TW is equal to or greater than a predetermined driving wheel torque T _W ′ during braking during low-speed deceleration traveling of the vehicle. Regeneration control by the motor generator MG is executed so that the regeneration execution amount set by the means 110 is obtained. Thus, part of the engine output is engine torque T _E that is transmitted to the drive wheels 52 is converted into an electric energy is suppressed, the driving wheel with respect to the braking torque (braking force) at the driven wheels 52 by the wheel braking device 80 The torque T _W (driving force) is controlled to be equal to or less than a predetermined driving wheel torque T _W ′. In other words, the engine torque T _E is taken out by the motor-generator MG, the braking torque (braking force) at the driven wheels 52 by fewer wheel braking device 80 the engine torque T _E that flows to the drive wheels 52 are lowered even appropriate A braking state is obtained.

However, even in the regeneration carried amount set by the regeneration amount setting means 110 is zero, the regeneration control means 112 normal engine rotational speed N _E is predetermined fast idle rotation speed, such as idling speed N _IDL after warmup _Ordinary regenerative control may be executed when N _IDLF 'or a predetermined idle up rotation speed N _IDLU ' is not exceeded. In this case, the regeneration amount setting means 110 sets the regeneration execution amount (increase regeneration amount) that is increased from the regeneration amount in the normal regeneration control by the regeneration control means 112. Therefore, the regeneration control unit 112 executes the regeneration control by the motor generator MG so that the increased regeneration amount set by the regeneration amount setting unit 110 is obtained in addition to the regeneration amount in the normal regeneration control.

The regenerative amount setting means 110 is at the time of vehicle braking when the foot brake operation determining means 104 determines that the foot brake is being depressed, and the low speed deceleration traveling determining means 106 determines that the vehicle is at a low vehicle speed. If it is not determined that the vehicle is decelerating or if the driving force determination means 108 does not determine that the driving wheel torque T _W is greater than or equal to the predetermined driving wheel torque T _W ′, the motor generator executed by the regeneration control means 112 The regeneration amount (regeneration amount) in the regeneration control by MG is set to zero, or the increased regeneration amount that is increased from the regeneration amount in the normal regeneration control by the regeneration control means 112 is set to zero.

Therefore, the regeneration control means 112 is at the time of vehicle braking when the foot brake operation determining means 104 determines that the foot brake is being depressed, and the low speed deceleration traveling determining means 106 decelerates the vehicle at a low vehicle speed. If it is not determined that the vehicle is traveling, or if it is not determined by the driving force determination means 108 that the driving wheel torque _TW is greater than or equal to the predetermined driving wheel torque T _W ′, regenerative control by the motor generator MG is not executed, or Normal regeneration control is performed at the normal idle rotation speed N _IDL or the like after warm-up.

FIG. 11 is a flowchart for explaining a main part of the control operation of the electronic control unit 90, that is, a control operation for obtaining an appropriate braking state at the time of braking at the time of vehicle low speed deceleration traveling, for example, several msec to several tens msec. It is repeatedly executed with an extremely short cycle time. FIG. 12 is a time chart for explaining the control operation shown in the flowchart of FIG. 11, and during braking at the time of vehicle low speed traveling when the gear stage of the automatic transmission 16 is the first gear stage. engine rotational speed N _E is an example of a case where regeneration control during idle-up exceeding the predetermined fast idle rotation speed N _{idlf 'and} a predetermined idle-up rotational speed N _IDLU' is executed.

First, in a step (hereinafter, step is omitted) S1 corresponding to the foot brake operation determining means 104, whether or not the foot brake is being depressed is detected by the operation of the brake pedal 82 detected by the foot brake switch 78. It is determined by whether or not the signal B _ON indicating is output. If the determination in S1 is negative, in S8, a normal control operation other than the control operation during the braking operation is executed, or the current vehicle running state is maintained and this routine is terminated.

If the determination in S1 is affirmative, in S2 corresponding to the low-speed deceleration travel determination means 106, whether or not the vehicle is traveling at a low vehicle speed, that is, the first speed gear stage travel and the deceleration travel, is determined by the vehicle speed V being a predetermined value. It is determined whether or not the vehicle speed V ′ or less and the accelerator opening degree Acc is substantially zero and the accelerator is decelerating, that is, coasting. Time point t ₁ in Figure 12 shows that the brake pedal 82 in the event of a vehicle low-speed deceleration is depression operation is determined.

In S3 corresponding to the driving force determination section 108 when the determination of the S2 is affirmative, whether the drive wheel torque T _W is higher than a predetermined driving wheel torque T _{W 'is,} the automatic transmission 16 is the first speed driven wheel torque T _W in a state where there is a gear stage so that a predetermined drive wheel torque T _{W 'predetermined} first the engine torque T _E that exceeds an idle rotation speed N _idlf' and a predetermined idle-up rotational speed N _{IDLU '} It is determined whether or not the idling speed N _IDL is controlled by the engine output control means 100. Figure _{t 2} time points 12 so that the engine rotational speed _{N E} exceeds the normal idle rotational speed _{N IDL} (Figure 12 by a two-dot chain line) higher predetermined fast idle rotation speed _{N idlf} 'and a predetermined idle-up rotational speed _{N IDLU'} This shows that it has been determined that the target value is controlled to the rotational speed (solid line in FIG. 12) during idle idling.

When the determination in S3 is affirmative, in S4 corresponding to the regeneration amount setting means 110, the regeneration amount in the regeneration control by the motor generator MG, or the normal regeneration at the normal idle rotation speed N _IDL after the warm-up, etc. engine from increasing the amount of regeneration amount is increased from the regeneration amount in the control, for example the regeneration amount higher the higher the engine speed N _E as shown in Figure 10 is stored previously obtained experimentally to increase relationship based on the rotational speed N _E (set) is determined. Subsequently, in S5 corresponding to the regeneration control means 112, regeneration control by the motor generator MG is executed so that the regeneration execution amount (increase regeneration amount) set in S4 is obtained.

If the determination in S2 is negative or the determination in S3 is negative, in S6 corresponding to the regeneration amount setting means 110, the regeneration execution amount in the regeneration control by the motor generator MG, or the normal after warm-up The regenerative amount that is increased from the regenerative amount in the normal regenerative control at the idle rotation speed N _IDL or the like is set to zero. Subsequently, in S7 corresponding to the regenerative control means 112, the regenerative control by the motor generator MG is not executed, or the normal regenerative control at the normal idle rotation speed N _IDL after the warm-up is executed.

T ₃ time to t ₅ the time in FIG. 12 indicates that the regeneration control by temporarily motor generator MG during braking operation as regeneration carried amount set based on the engine rotational speed N _E is obtained is running ing. Also, the broken line of the braking torque shown in FIG. 12 shows the characteristic when the regenerative control by the motor generator MG is not executed when the engine speed _NE is the idling up speed (solid line in FIG. 12). , and the shows that the engine torque T _E is larger braking torque than just to higher amount compared to such normal idle rotational speed N _IDL after warm-up is required. On the other hand, the solid line of the braking torque shown in FIG. 12 is a characteristic when the regenerative control is temporarily executed, and is required in the case of the normal idle rotation speed N _IDL after warm-up or the like. Corresponds to braking torque.

As described above, according to the present embodiment, when the vehicle is traveling at a low speed and when the vehicle brake operation is performed by the wheel brake device 80, the drive wheel torque with respect to the brake torque (braking force) of the drive wheel 52 by the wheel brake device 80 is reduced. T _W regenerative control by the motor generator MG is performed by the regenerative control means 112 to a predetermined drive wheel torque T _{W 'follows.} Thus, the engine torque T _E that part of the engine output is transmitted is converted into an electric energy to the drive wheels 52 is suppressed, for example, the gear ratio of first gear position of the automatic transmission 16 is larger than the conventional Even so, the driving force generated in the driving wheel 52 during low-speed deceleration traveling in the first speed gear stage is suppressed, and an appropriate braking state can be obtained with the braking force by the conventional wheel brake device 80. For example, when the front wheel braking force is not substantially sufficiently obtained as in a low μ road where a road surface frictional force cannot be obtained, an appropriate braking state can be obtained as usual.

Further, according to this embodiment, since the regeneration control is executed by the regeneration control means 112 as regeneration amount that is set according to the engine rotational speed N _E is obtained by regeneration amount setting means 110, the engine speed N _{Even if E} is controlled at a higher rotational speed than the normal idle rotational speed N _IDL after warming up and the engine output is increased, the driving force (creep force) generated in the drive wheels 52 is suppressed, and the conventional wheel brake device An appropriate braking state is obtained with the braking force of 80.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

For example, in the above-described embodiment, the regeneration control by the regeneration control means 112 is executed when the automatic transmission 16 is in the first speed gear stage, but the automatic transmission 16 is in the first speed gear stage. If the driving wheel torque T _W exceeds the predetermined driving wheel torque T _W ′ with respect to the braking torque on the driving wheel 52 by the wheel brake device 80, the regeneration control by the motor generator MG is executed by the regeneration control means 112. Is done.

In the above-described embodiment, the regeneration control by the regeneration control means 112 is executed when the engine output control means 100 is idling up, but the wheel is not required at the time of idling up such as the normal idle rotation speed N _IDL after warming up. When the driving wheel torque T _W exceeds the predetermined driving wheel torque T _W ′ with respect to the braking torque on the driving wheel 52 by the brake device 80, the regeneration control by the motor generator MG is executed by the regeneration control means 112.

In the illustrated embodiment, the driving force determination means 108 _'whether more than the drive wheel torque T _W is a predetermined drive wheel torque T _W' drive wheel torque T _W is a predetermined drive wheel torque T _W exceeds Based on whether or not the engine output control means 100 controls the idle rotation speed N _IDL so that the engine speed T _E becomes a predetermined first idle rotation speed N _IDLF ′ or a predetermined idle up rotation speed N _IDLU ′. The predetermined driving in which the actually obtained driving wheel torque T _W (= engine torque T _E × speed ratio γ of the automatic transmission 16 × reduction ratio i of the final reduction gear) is set in advance. The determination may be made based on whether or not the wheel torque T _W ′ has been exceeded.

  In the above-described embodiment, the wheel brake device 80 is provided with a proportioning valve (P valve) 86 in the middle of the piping on the rear wheel 52R side as a hydraulic pressure control valve for controlling the braking force distribution of the front and rear wheels. However, other hydraulic pressure control valves such as so-called limiting (L) valves and G valves may be used instead of the P valves.

Further, in addition to the above-described embodiment, the electronic control unit 90 functionally includes a regenerative control availability determination unit that determines whether or not the regenerative control can be executed by the regenerative control unit 112, and the regenerative control availability determination unit. Thus, when it is determined that the regeneration control by the regeneration control means 112 cannot be executed, the idle output by the engine output control means 100 may not be executed. For example, the regeneration control determination means, charging of the battery 70 meets the _80% charge capacity _SOC of about 80% of the upper limit _{SOC MAX} example full charge of the charging capacitor charging capacity SOC reaches a predetermined battery 70 The regenerative control means 112 may be used for reasons such as failure of power generation capability due to failure (failure) of the motor generator MG, the inverter 72, the battery 70, a transmission line connecting them, or a reduction in function. It is determined that the regenerative control cannot be executed.

Further, the power transmission device 8 of the above-described embodiment is provided with a fluid transmission device, and the output of the engine 10 is transmitted to the drive wheels 52 via the fluid transmission device. However, the fluid transmission device is not necessarily provided. need not, a vehicle stopped or at low speed deceleration with also maintained the engine rotational speed N _E, for example, the idling speed N _IDL, so that the drive wheel torque T _W due to creep torque to the drive wheels 52 occurs The present invention can be applied to any power transmission device. For example, a clutch is provided in place of the fluid transmission device, and the clutch is arranged so that the engine rotation speed _NE is maintained while the vehicle is stopped or the vehicle is decelerating at low speed, and the drive wheel torque _TW is generated by creep torque. A power transmission device capable of slip control may be used. Further, although the torque converter 14 with the lock-up clutch 26 is used as the fluid transmission device, a torque converter without a lock-up clutch or a fluid coupling (fluid coupling) having no torque amplification function may be used. it can.

  In the above-described embodiment, the automatic transmission 16 is a five-speed forward transmission composed of a combination of four planetary gear units 36, 40, 42, and 44, but the planetary gear constituting the automatic transmission 16 is also used. The number of sets of devices may be different from four sets, or may be a forward 6-speed transmission, a forward 4-speed transmission, or the like.

  In the above-described embodiment, the battery 70 that is a storage battery is used as the power storage device, but a capacitor that is a power storage device may be used as the power storage device. Alternatively, both a storage battery and a capacitor may be used as the power storage device.

  Further, the motor generator MG of the above-described embodiment may be any one that functions as a generator only at the time of regeneration as a rotating electrical machine. Further, even if this motor generator MG is not operatively connected to the output shaft 46 of the automatic transmission 16, it is disposed in the power transmission path between the engine 10 and the drive wheels 52 and is driven to rotate by the power of the engine to generate power. Any device that functions as a machine may be used.

  In the above-described embodiment, the clutch C or the brake B that is an engagement element of the automatic transmission 16 is a hydraulic friction engagement device. However, an electromagnetic engagement device such as an electromagnetic clutch or a magnetic powder clutch is used. There may be.

  The above description is only an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

1 is a skeleton diagram illustrating a power transmission device for a vehicle to which the present invention is applied. FIG. 2 is a diagram illustrating a relationship between a combination of operations of a plurality of hydraulic friction engagement devices and a shift speed established thereby in the automatic transmission of FIG. 1. It is a figure explaining schematic structure of the power transmission device of the vehicle of FIG. It is a figure for explaining a wheel brake device in detail, (a) is a figure explaining the composition of a wheel brake device roughly, (b) shows the actual front-and-rear wheel braking force distribution by a wheel brake device. is there. It is a block diagram explaining the principal part of the input-output system of the electronic controller with which the power transmission device of FIG. 1 is provided. It is a figure which shows the shift operation apparatus provided in the vehicle of FIG. It is a functional block diagram explaining the principal part of the control function with which the electronic control apparatus of FIG. 5 is provided. It is a figure which shows the relationship between the throttle valve opening of an engine and the accelerator opening in the power transmission device of FIG. It is a figure explaining the shift diagram used for the shift control of the automatic transmission in the power transmission device of FIG. This is a relationship that has been experimentally obtained and stored in advance for determining the amount of regeneration performed based on the engine rotation speed. FIG. 6 is a flowchart for explaining a main part of the control operation of the electronic control device of FIG. 5, that is, a control operation for obtaining an appropriate braking state at the time of braking at the time of vehicle low speed deceleration traveling. FIG. 12 is a time chart for explaining the control operation shown in the flowchart of FIG. 11, in which the engine speed is a predetermined first idle during braking when the vehicle is decelerating when the gear stage of the automatic transmission is set to the first speed gear stage. This is an example when the regenerative control is executed at the time of idle-up exceeding the rotation speed or a predetermined idle-up rotation speed.

Explanation of symbols

8: Power transmission device 10: Engine (drive power source)
16: Automatic transmission 52: Drive wheel 90: Electronic control device (control device)
110: Regeneration amount setting means 112: Regeneration control means MG: Motor generator (electric motor)

Claims (4)

A vehicle control apparatus comprising: a driving force source; and a power transmission device provided in a power transmission path from the driving force source to the driving wheel and having an electric motor,
When the vehicle is decelerated at a low speed and the vehicle is braked by the driver, regenerative control is performed by the electric motor so that the driving force of the driving wheel is less than a predetermined value than the braking force of the driving wheel based on the vehicle braking operation. And a regenerative control means for suppressing power transmitted to the drive wheels. The driving force source is an engine;
2. The vehicle control device according to claim 1, wherein the regeneration control means executes regeneration control when the rotational speed of the engine is controlled at a rotational speed higher than a normal idle rotational speed in accordance with a vehicle state. Regenerative amount setting means for setting a regenerative amount during regenerative control by the regenerative control means according to the engine speed,
The vehicle control device according to claim 2, wherein the regeneration control means executes regeneration control so that the regeneration amount set by the regeneration amount setting means is obtained. The power transmission device has an automatic transmission,
4. The vehicle control device according to claim 1, wherein the regenerative control means executes the regenerative control when the automatic transmission is set to a lowest speed side gear ratio. 5.

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