Vehicle control system

Abstract

To provide a control device of a vehicle in which a shock caused by backlash elimination is suppressed upon acceleration operation of an electric motor travel.SOLUTION: When reacceleration operation from during travelling using an electric motor with a relatively low load of drive power of a vehicle 10 is performed, rotation speed control of the electric motor MG for setting differential rotation ΔNWSC of a start clutch WSC as a target differential rotation ΔNT is retarded until an instruction input torque to the start clutch WSC passes through a backlash elimination area RGP of the start clutch WSC. Because the rotation speed control of the electric motor MG is retarded until the instruction input torque to the electric motor MG passes through the backlash elimination area RGP of the start clutch WSC, a backlash elimination shock caused by the rotation speed control of the electric motor MG for controlling the differential rotation ΔNWSC of the start clutch WSC after starting engine initiation is suppressed.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a vehicle control device that suppresses backlash shock of a gear mechanism when starting an engine by a re-acceleration operation performed during light-load motor driving.

Background Art

[0002] There are provided an engine, an electric motor, a first clutch that disconnects and connects a power transmission path between the engine and the electric motor, a second clutch that can mechanically directly connect between the engine, the electric motor, and drive wheels, and a gear mechanism provided between the second clutch and the drive wheels. During motor driving in which only the electric motor is used as a driving power source for traveling with the first clutch disengaged and the second clutch engaged, when starting the engine by controlling the first clutch to engage, a vehicle control device that slips the second clutch by controlling the rotational speed of the electric motor is known. For example, the drive device of a hybrid vehicle described in Patent Document 1 is such.

[0003] In the vehicle configured as described above, when starting the engine during motor driving, first, the engagement hydraulic pressure of the second clutch is reduced. When the torque of the second clutch has decreased to near the input torque determined from the required drive torque, the output of the electric motor is increased and rotational speed control is performed to maintain the differential rotation of the second clutch, so that the input rotational speed of the second clutch is increased by a predetermined value while slipping the second clutch. In such a vehicle, the rotation of the engine is increased by slipping the first clutch for starting the engine, and while the vehicle is driven by the electric motor via the slipping second clutch, the input rotational speed of the second clutch is increased by a predetermined value by the rotational speed control of the electric motor that maintains the differential rotation of the second clutch. Therefore, the influence of the draw-in of the vehicle drive torque when increasing the engine rotation via the first clutch is suppressed. [[ID=十七]]

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, regarding the re-acceleration operation in which the accelerator is depressed during the running of the motor under a light load including the driven state, during the backlash elimination control of the gear mechanism in the power transmission path from the second clutch to the drive wheels, or when a start command for the engine is issued before the completion of the backlash elimination before the backlash elimination control, there is a problem that the input torque to the gear mechanism suddenly changes at the start of slip of the second clutch by the rotational speed control of the motor, and the backlash elimination shock becomes large.

[0006] For example, when the torque variation of the second clutch becomes larger than the command torque to the second clutch, when the rotational speed control of the motor tries to cause slip in the second clutch, the second clutch does not start to slip unless the rotational speed control of the motor outputs a torque larger than the torque of the second clutch. For this reason, the torque of the motor increases by the rotational speed control of the motor, and the increase portion accelerates the progress of the backlash elimination control, resulting in a problem that the backlash elimination shock becomes large.

[0007] The present invention has been made in view of the above circumstances, and an object thereof is to provide a vehicle control device in which the backlash elimination shock of the gear mechanism is suppressed during an acceleration operation while the motor is running.

Means for Solving the Problems

[0008] The gist of the present invention is that (a) an engine, an electric motor, a first clutch that disconnects and connects the power transmission path between the engine and the electric motor, a second clutch that can mechanically connect the engine and the electric motor to the drive wheels in a direct connection state, and a gear mechanism provided between the second clutch and the drive wheels, and releasing the first clutch、 and The static second clutch command torque corresponding to the required drive torque calculated based on the accelerator opening is annealed to a dynamic second clutch command torque that reduces the vehicle's longitudinal acceleration. A vehicle control device that, when starting the engine by controlling the first clutch toward engagement during electric motor driving, in which the vehicle is driven solely by the electric motor with the second clutch engaged, controls the rotational speed of the electric motor to maintain the differential rotation of the second clutch, thereby increasing the input rotation of the second clutch by a predetermined value and causing the second clutch to slip, wherein (b) the second clutch has a torque characteristic in which the torque rises after passing through a play-reducing region for eliminating play in the gear mechanism, and (c) when a re-acceleration operation is performed during electric motor driving, the rotational speed control of the electric motor is activated after the command input torque, which is the torque command value of the electric motor, has passed through the play-reducing region. (d) The rotational speed control of the electric motor is performed on the condition that the dynamic second clutch command torque exceeds the actual transmission torque obtained from the engagement hydraulic pressure of the second clutch plus a negative margin. It is about that. [Effects of the Invention]

[0009] According to the vehicle control device of the present invention, when a re-acceleration operation is performed while the electric motor is running, the rotational speed control of the electric motor is activated after the command input torque has passed the rattle reduction region. In this way, since the rotational speed control of the electric motor is delayed until the command input torque has passed the rattle reduction region, the rattle reduction shock caused by the rotational speed control of the electric motor at the start of engine start control is suppressed. Furthermore, since motor speed control is performed only when the dynamic second clutch command torque exceeds the actual transmission torque obtained from the engagement hydraulic pressure of the second clutch plus a negative margin, the start of motor speed control is reliably permitted before the dynamic second clutch command torque approaches the actual torque and before the dynamic second clutch command torque moves out of the backlash reduction region. [Brief explanation of the drawing]

[0010] [Figure 1] This diagram illustrates the schematic configuration of a vehicle to which the present invention is applied, as well as the main parts of the control functions and control systems for various control functions in the vehicle. [Figure 2] This diagram illustrates the play in the gear mechanism in the power transmission path from the starting clutch to the drive wheels of the vehicle shown in Figure 1. [Figure 3] Figure 2 shows the torque characteristics of the starting clutch, illustrating the rise in torque transmission from the starting clutch. [Figure 4]This is a flowchart illustrating the key aspects of the control operation of an electronic control unit. [Figure 5] This is a time chart explaining the key parts of the control operation of an electronic control unit. [Modes for carrying out the invention]

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. [Examples]

[0012] In Figure 1, the vehicle 10 is a hybrid vehicle equipped with an engine 12 and an electric motor MG, which function as power sources. The vehicle 10 also includes drive wheels 14 and a power transmission device 16 provided in the power transmission path between the engine 12 and the drive wheels 14.

[0013] The engine torque Te, which is the output torque of the engine 12, is controlled by the engine control device 50, which is controlled by the electronic control device 90, which will be described later.

[0014] The electric motor MG is a rotating electric machine that has the functions of both an engine and a generator, and is a so-called motor generator. 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 MG torque Tm, which is the torque of the electric motor MG, is controlled by the inverter 52 controlled by an electronic control device 90, which will be described later. In the case of forward rotation, which is the rotation direction of the engine 12, the MG torque Tm is the power torque when it is a positive torque on the acceleration side, and the regenerative torque when it is a negative torque on the deceleration side.

[0015] The power transmission device 16 is housed in a case 18, which is a non-rotating member attached to the vehicle body, and includes a disengagement clutch K0, a starting clutch WSC, an automatic transmission 20, a reduction gear mechanism 22, a differential gear 24, and the like. The disengagement clutch K0 is a clutch provided between the engine 12 and the electric motor MG in the power transmission path between the engine 12 and the drive wheels 14. The starting clutch WSC is a clutch provided between the engine 12 and the electric motor MG and the drive wheels 14, particularly the automatic transmission 20, in the power transmission path between the engine 12 and the drive wheels 14. As shown in Figure 2, the power transmission path between the starting clutch WSC and the drive wheels 14 includes a gear mechanism HG that forms play GT, such as the automatic transmission 20 and the differential gear 24.

[0016] The power transmission device 16 includes a pair of drive shafts 28 connected to the differential gear 24, etc. Within the case 18, the power transmission device 16 includes an engine connecting shaft 30 that connects the engine 12 and the engagement / disengagement clutch K0, an electric motor connecting shaft 32 that connects the engagement / disengagement clutch K0 and the starting clutch WSC, etc. The power transmission device 16 also includes a mechanical oil pump 34, which is a mechanical oil pump, a transmission member 36 that connects the electric motor connecting shaft 32 and the mechanical oil pump 34, etc.

[0017] The engagement / disengagement clutch K0 is a wet or dry friction engagement device composed of, for example, a multi-plate or single-plate clutch pressed by an actuator. The engagement / disengagement clutch K0 is switched between operating states, i.e., control states, such as full engagement, slip, and disengagement, by changing the torque capacity K0 torque Tk0 of the engagement / disengagement clutch K0, which is supplied by the hydraulic pressure PRk0 of the hydraulic control circuit 56 provided in the vehicle 10.

[0018] When the engagement clutch K0 is engaged, the engine 12 and the electric motor MG are connected in a way that allows for power transmission. When the engagement clutch K0 is released, power transmission between the engine 12 and the electric motor MG is interrupted. The engagement clutch K0 functions as a first clutch that connects and disconnects the engine 12 from the electric motor MG, that is, it connects and disconnects the engine 12 from the electric motor MG.

[0019] The starting clutch WSC is controlled by the engagement hydraulic pressure Pwsc supplied from the hydraulic control circuit 56, which switches between fully engaged, slipped, and disengaged states. The starting clutch WSC suppresses shocks caused by torque fluctuations associated with starting and stopping the engine 12, and slips when the input rotational speed Ni of the automatic transmission 20 is below the rotational speed Ne of the engine 12 at low vehicle speeds. The starting clutch WSC is, for example, a wet multi-plate hydraulic clutch and functions as a second clutch.

[0020] The starting clutch WSC is shown in Figure 3, and the torque transmission T of the starting clutch WSC is shown. WSC As shown in the two-dimensional coordinate system with the vertical axis representing (Nm) and the horizontal axis representing time (sec), the backlash reduction section T increases relatively slowly at a first torque increase rate as time elapses from when the accelerator is pressed (time t0), initially in order to eliminate the backlash in the gear mechanisms such as the automatic transmission 20 and differential gear 24. GP After the passage of time (at time t4), the torque characteristic is such that the backlash GT is eliminated, resulting in a linear increase in torque at a predetermined second rate of increase that is greater than the first torque increase rate. On the vertical axis, the backlash elimination section T from time t1 to time t4. GP The corresponding torque range is the backlash reduction region R. GP As described later, the static WSC command torque T corresponding to the required drive torque calculated based on the accelerator opening θacc exists. WSCB Dynamic WSC command torque T annealed to mitigate the vehicle's longitudinal acceleration. WSCD Torque control of the starting clutch WSC is performed using this method.

[0021] The automatic transmission 20 is a known planetary gear type automatic transmission comprising, for example, one or more sets of planetary gears (not shown) and an engagement device CB. The engagement device CB represents a plurality of clutches and brakes, and each of them is selectively switched between control states such as full engagement, slip, and disengagement by changing the torque capacity of the respective clutch, CB torque Tcb, by the CB hydraulic pressure PRcb, which is a regulated hydraulic pressure supplied from the hydraulic control circuit 56.

[0022] The automatic transmission 20 switches gears according to the driver's accelerator operation, vehicle speed V, etc., by selectively switching the combination of operations of the engagement device CB by the electronic control device 90 described later. The AT input rotational speed Ni is the rotational speed of the transmission input shaft 38 and is the input rotational speed of the automatic transmission 20. The AT input rotational speed Ni is also the rotational speed of the output side member of the starting clutch WSC. The AT output rotational speed No is the rotational speed of the transmission output gear 26 and is the output rotational speed of the automatic transmission 20.

[0023] The hydraulic oil discharged by the mechanical oil pump 34, which is connected to the motor coupling shaft 32 via the transmission member 36, and the electric oil pump 58, which is driven by the pump motor 60, is supplied to the hydraulic control circuit 56. The hydraulic control circuit 56 supplies pressure-regulated hydraulic fluids such as K0 (PRk0), WSC (PRwsc), and CB (PRcb), which are adjusted based on the hydraulic oil discharged by at least one of the mechanical oil pump 34 and the electric oil pump 58. The hydraulic oil is also used, for example, to lubricate various parts of the power transmission device 16.

[0024] Vehicle 10 is equipped with a wheel brake system 62. The wheel brake system 62 includes a brake master cylinder and a cylinder actuator (not shown) that generate brake hydraulic pressure. Each wheel of vehicle 10, including the drive wheels 14, is equipped with a wheel brake 64. The wheel brake system 62 is a brake system that applies a wheel braking torque TBw, which is the braking torque TB applied by the wheel brake 64, to the wheels according to a command from an electronic control unit 90 (described later). In the wheel brake system 62, under normal circumstances, master cylinder hydraulic pressure, which is generated from the brake master cylinder and corresponds to the brake operation amount Bra, is supplied to the wheel cylinders as brake hydraulic pressure. In the wheel brake system 62, for example, during various control operations such as ABS control, brake hydraulic pressure corresponding to the wheel braking torque TBw required for each control operation is supplied to the wheel cylinders in order to generate the wheel braking torque TBw.

[0025] Vehicle 10 is further equipped with an electronic control unit 90, which acts as a controller including a control device for vehicle 10. The electronic control unit 90 is configured to include, for example, a so-called microcomputer, and performs various controls of vehicle 10 by performing signal processing according to a pre-stored program. The electronic control unit 90 is configured to include computers for engine control, electric motor control, hydraulic control, etc., as needed.

[0026] The electronic control unit 90 receives various signals based on values ​​detected by various sensors provided in the vehicle 10 (for example, engine rotation speed sensor 70, MG rotation speed sensor 72, input rotation speed sensor 74, output rotation speed sensor 76, accelerator opening sensor 78, throttle valve opening sensor 80, brake sensor 82, battery sensor 84, oil temperature sensor 86, etc.) (for example, engine rotation speed Ne (rpm), which is the rotation speed of the engine 12; MG rotation speed Nm (rpm), which is the rotation speed of the electric motor MG and is also the rotation speed of the input side member of the starting clutch WSC; AT input rotation speed Ni (rpm); and vehicle speed V. The following parameters are supplied: the AT output rotational speed No (rpm), the accelerator opening θacc (%) which represents the amount of accelerator operation by the driver that indicates the magnitude of the driver's acceleration operation, the throttle valve opening θth (%) which is the opening degree of the electronic throttle valve, the brake-on signal Bon which is a signal indicating that the brake pedal for activating the wheel brake 64 is being operated by the driver, the brake operation amount Bra, the battery temperature THbat of the battery 54, the battery charge / discharge current Ibat (I), the battery voltage Vbat (V), and the hydraulic oil temperature THoil (°C) which is the temperature of the hydraulic oil in the hydraulic control circuit 56.

[0027] The electronic control unit 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 engagement clutch K0, a WSC hydraulic control command signal Swsc for controlling the starting clutch WSC, an electric oil pump control command signal Seop for controlling the electric oil pump 58, and a brake control command signal Sbra for controlling the wheel braking torque TBw) to each device installed in the vehicle 10 (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 engagement clutch K0, a WSC hydraulic control command signal Swsc for controlling the starting clutch WSC, an electric oil pump control command signal Seop for controlling the electric oil pump 58, and a brake control command signal Sbra for controlling the wheel braking torque TBw).

[0028] The electronic control unit 90 is functionally 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, and a braking control means, i.e., a braking control unit 96, in order to realize various controls in the vehicle 10.

[0029] The power source control unit 92 includes functions for controlling the operation of the engine 12 and the operation of the electric motor MG, and these control functions enable hybrid drive control of the engine 12 and the electric motor MG.

[0030] The power source control unit 92 calculates the amount of drive requested by the driver to the vehicle 10 by, for example, applying the accelerator opening θacc and the vehicle speed V to the drive request amount map. The drive request amount map is a relationship for determining the drive request amount that has been determined and stored in advance experimentally or by design. The drive request amount is, for example, the requested drive torque Trdem [Nm] at the drive wheels 14. The power source control unit 92 outputs an engine control command signal Se to control the engine 12 and an MG control command signal Sm to control the electric motor MG, taking into account transmission losses, auxiliary loads, the gear ratio γat of the automatic transmission 20, etc., in order to realize the requested drive power Prdem.

[0031] The power source control unit 92 sets the drive mode for driving the vehicle 10 to a BEV drive mode, which uses only the electric motor MG as the power source, if the required drive torque Trdem can be met by the output of the electric motor MG alone. On the other hand, if the required drive torque Trdem cannot be met without using at least the output of the engine 12, the power source control unit 92 sets the drive mode for driving the vehicle 10 to an HEV drive mode, which uses at least the engine 12 as the power source when the engagement clutch K0 is engaged. The HEV drive mode is a hybrid drive mode that enables hybrid driving (=HEV driving).

[0032] The power source control unit 92 determines, for example, whether or not there is an engine start request when the BEV drive mode is in operation, based on the fact that the requested drive torque Trdem has increased beyond the range that can be covered by the output of the electric motor MG alone.

[0033] When the power source control unit 92 determines that there is an engine start request, it controls the engine 12 and the motor MG so as to execute the start control of the engine 12. For example, the power source control unit 92 outputs an MG control command signal Sm for the motor MG to output a cranking torque Tcr in accordance with the switching of the engagement state of the disconnect clutch K0 by the clutch control unit 94. Further, the power source control unit 92 outputs an engine control command signal Se for starting fuel supply, engine ignition, etc. in conjunction with the cranking of the engine 12.

[0034] During the running of the vehicle 10, the power source control unit 92 calculates a driving force target value corresponding to the required driving force of the vehicle 10 calculated based on the accelerator opening θacc and the vehicle speed V from a predetermined relationship. When the vehicle is running on the motor, the power source control unit 92 calculates a static driving force target value PMGB corresponding to the driving force target value and a dynamic driving force target value P MGB obtained by applying smoothing processing to the front and rear G of the vehicle. MGD Further, the power source control unit 92 uses, as a command value for controlling the output torque Tm of the motor MG, a static command WSC input torque T MGB converted from P WSCINB and a dynamic command WSC input torque T[[ID=1⑤]] MGD converted from the dynamic driving force target value P WSCIND are calculated. During motor running, a torque T corresponding to the dynamic command WSC input torque T WSCIND is input to the starting clutch WSC from the motor MG. The dynamic command WSC input torque T WSCIND is the substantial command input torque of the motor MG.

[0035] The clutch control unit 94 calculates a static WSC command torque T WSC that is slightly larger than the static command WSC input torque T MGB converted from the static driving force target value P WSCINB as a command value for controlling the transmission torque T WSCB so as not to generate slip in the starting clutch WSC as much as possible, and the dynamic command WSC input torque T WSCINDA slightly larger dynamic WSC command torque T WSCD Calculate the dynamic WSC command torque T. WSCD As a result, static WSC command torque T WSCB This is the result of annealing. Dynamic WSC command torque T WSCD This is the command value for the transmission torque of the starting clutch WSC, and is the dynamic command WSC input torque T that controls the torque input from the electric motor MG to the starting clutch WSC. WSCIND This differs from the above.

[0036] If the power source control unit 92 determines that there is a request to start the engine while the vehicle 10 is running as a BEV, the following engine start control is performed. First, the clutch control unit 94 reduces the engagement hydraulic pressure Pwsc of the starting clutch WSC, and the transmission torque T of the starting clutch WSC is reduced. WSC However, once the output torque Tm from the electric motor MG drops, the dynamic WSC command torque T WSCD However, the transmission torque of the starting clutch WSC (engagement hydraulic pressure P WSC (Actual transmission torque calculated from) T WSC The power source control unit 92 performs rotational speed control of the electric motor MG, provided that the value exceeds the value obtained by adding a negative margin α. This rotational speed control is not affected by the torque consumed to increase the rotational speed of the engine 12 due to the slip of the disengagement clutch K0 when the starting clutch WSC is in a slip state, and is controlled by the difference rotation ΔN due to the slip of the starting clutch WSC. WSCThe output of the electric motor MG is adjusted (feedback control) so that the rotational speed (rpm) is maintained at a target difference rotation ΔNT calculated based on the input torque (output torque Tm) of the starting clutch WSC from a pre-stored relationship, and the rotational speed Nm of the electric motor MG is set to a higher rotational speed Nin than the input rotational speed Nin of the automatic transmission 20. In this state, when an engine start request is made, the clutch control unit 94 outputs a K0 hydraulic control command signal Sk0 to control the disengaged clutch K0 towards the engaged state so that a K0 torque Tk0 is obtained to transmit the cranking torque Tcr to the engine 12. As a result, the electric motor MG transmits the cranking torque Tcr to the engine 12 via the disengaged clutch K0, and the engine rotational speed Ne is increased.

[0037] Here, when the accelerator opening θacc is zero or small when the engine start request is issued, and the motor is driving under controlled or light load conditions, the driving torque To of the vehicle 10 is negative or close to zero, then play GT is formed in the gear mechanism HG. In such cases, the dynamic command WSC input torque T is the command torque for the electric motor MG. WSCIND However, as shown in Figure 3, the pre-set clearance area R GP The power source control unit 92 controls the static command WSC input torque T WSCINB The area R is a rough patch. GP Assuming it is outside, the dynamic command WSC input torque T WSCIND The area R is a rough patch. GP If it is within the range, the play reduction area R GP The execution of the rotational speed control of the electric motor (MG) is delayed until it becomes external, that is, from time t2 to time t4.

[0038] The braking control unit 96 sets the required braking torque TBdem based on, for example, the driver's accelerator operation (e.g., accelerator opening θacc (%), rate of decrease of accelerator opening θacc), vehicle speed V (km / h), gradient of the downhill road, and the driver's brake operation to activate the wheel brake 64 (e.g., brake operation amount Bra, rate of increase of brake operation amount Bra). The braking control unit 96 outputs a command to the power source control unit 92 to execute regenerative control by the electric motor MG so that the regenerative torque required to achieve the required regenerative braking torque TBr is obtained. The braking control unit 96 outputs a brake control command signal Sbra to the wheel brake device 62 to activate the wheel brake 64 so that the required wheel braking torque TBw is obtained.

[0039] Figure 4 is a flowchart illustrating the control operation of the clutch control unit 94 of the electronic control device 90, specifically the control when engine start is determined to occur due to acceleration operation during electric motor operation. In step S1 of Figure 4 (the step will be omitted hereafter), it is determined whether or not engine start control is being performed, triggered by an engine start request due to accelerator operation. If the determination in S1 is negative, it means that electric motor operation is under light load with accelerator operation without engine start, so in S6, the delay request for rotational speed control by the electric motor MG is turned OFF, and the control cycle returns to the beginning. In the time chart of Figure 5, time t0 indicates the start of accelerator operation during electric motor operation. Time t1 in Figure 5 indicates the time when the dynamic driving force target value transitions from negative to positive, and between time t1 and time t4, the command torque (dynamic WSC command torque T) to the electric motor MG is WSCD This indicates a small value.

[0040] If the judgment in S1 is affirmed, then in S2, it is determined whether or not an engine start command was issued in the previous control cycle and whether or not this is the first engine start command. If the judgment in S2 is affirmed, then it is the first time an engine start command has been issued, and in S3, the dynamic command WSC input torque T WSCIND The area R is a rough patch. GPIt is determined whether or not it is inside. If the determination in S3 is negative, the process is repeated, returning to the beginning of the next control cycle, and the system is kept waiting.

[0041] If the judgment in S3 is affirmed, in S4, the static command WSC input torque T WSCINB The area R is a rough patch. GP It is determined whether or not the vehicle is outside the designated area. If the determination in S4 is negative, the control cycle is returned to the beginning and the vehicle is kept in standby mode. However, if the determination in S4 is positive, in S5, the request for delay in the rotational speed control of the electric motor MG is turned on. As a result, the rotational speed control of the electric motor MG is delayed, which suppresses the occurrence of rattle shock caused by the rotational speed control of the electric motor MG when the accelerator opening θ is small during electric motor driving. Figure 5 shows this state at time t2. Note that at time t3 in Figure 5, the engagement hydraulic pressure P of the starting clutch WSC is... WSC Estimated torque T calculated based on WSC The value obtained by adding a margin α to the dynamic WSC command torque T is then used. WSCD The fact that it exceeded (T WSCD >T WSC Due to the additional (+α) factor, rotational speed control of the electric motor (MG) is permitted.

[0042] In the above state, the decision in S2 will be rejected in the next control cycle, so in S7, the dynamic command WSC input torque T WSCIND The area R is a rough patch. GP It is determined whether it is outside or outside. If the judgment in S7 is negative, the control cycle is returned to the beginning and repeated. However, if the judgment in S6 is positive, the dynamic command WSC input torque T WSCIND The stroke back area R SB Since the state has been switched to external, in S8, after the delay request for the rotation speed control of the electric motor MG is turned OFF, the system returns to the beginning of the next control cycle.

[0043] At time t5 in Figure 5, the engine speed is increased by the electric motor MG and the engagement / disengagement clutch K0, and at time t6, the dynamic command WSC input torque T WSCINDStatic command WSC input torque T WSCINB At time t7, the engagement of the starting clutch WSC is complete, indicating the end of engine start control. Between time t4 and t7 in Figure 5, the rotational speed Nm of the electric motor MG exceeds the input rotational speed Ni of the automatic transmission 20 due to slippage of the starting clutch WSC.

[0044] As described above, according to this embodiment, when a re-acceleration operation is performed while the vehicle 10 is running under a light load with relatively low driving force, the difference rotation ΔN of the starting clutch WSC occurs. WSC The rotational speed control of the electric motor MG to achieve the target difference rotation ΔNT is controlled by the command torque to the starting clutch WSC within the play-reducing region R of the starting clutch WSC. GP The rotational speed control of the electric motor (MG) is delayed until it passes through the play-reducing region of the starting clutch (WSC). GP Because it is delayed until it passes, the difference rotation ΔN of the starting clutch WSC immediately after the engine starts up. WSC The rattle-reducing shock caused by the rotational speed control of the electric motor (MG) used to control it is suppressed.

[0045] Furthermore, according to this embodiment, the static command input torque (static WSC command torque) T of the starting clutch WSC corresponds to the required drive torque calculated based on the accelerator opening θacc and vehicle speed V. WSCB The area R is a rough patch. GP External and static WSC command torque T WSCB Dynamic WSC command torque T after annealing WSCD The area R is a rough patch. GP When this is the case, the rotational speed control of the electric motor (MG) is delayed. This results in a dynamic WSC command torque T WSCD When it is clear that the destination is on the side of increasing the commanded torque, the rotational speed control of the electric motor (MG) is delayed, thereby providing stable control to prevent backlash shock.

[0046] Furthermore, according to this embodiment, the command input torque of the starting clutch WSC, i.e., the dynamic WSC command torque T, is defined. WSCD The area R is a rough patch.GP If the gear deviates from this state, the rotational speed control of the electric motor (MG) begins, so the rotational speed control of the electric motor (MG) does not prematurely eliminate the play in the gear mechanism.

[0047] Furthermore, according to this embodiment, the dynamic WSC command torque T WSCD The starting clutch WSC engagement hydraulic P WSC The estimated (actual) torque T is obtained from this. WSC When the value exceeds the value obtained by adding a negative margin, the motor MG's rotational speed control is permitted to begin. This controls the dynamic WSC command torque T WSCD The estimated (actual) torque T WSC Before approaching, dynamic WSC command torque T WSCD The area R is a rough patch. GP Before deviating from the control system, the start of rotational speed control for the electric motor (MG) is ensured.

[0048] It should be noted that the above-described embodiment is merely one example, and the present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art.

[0049] For example, in the embodiment described above, the starting clutch WSC functioned as the second clutch, but any of the engagement devices CB in the automatic transmission 20 may be made to function as the second clutch. Also, if a torque converter with a lock-up clutch is used instead of the starting clutch WSC, the lock-up clutch may be made to function as the second clutch. [Explanation of Symbols]

[0050] 10: Vehicles 12: Engine 14: Drive wheels 90: Electronic control unit (control device) K0: Disconnecting clutch (first clutch) WSC: Starting Clutch (Second Clutch) MG: Electric motor T WSCB Static WSC command torque (static second clutch command torque) T WSCDDynamic WSC command torque (dynamic second clutch command torque) T WSCINB : Static command WSC input torque (Static command 2nd clutch input torque) T WSCIND : Dynamic command WSC input torque (Dynamic command 2nd clutch input torque) R GP : Area to tighten gaps

Claims

1. A vehicle control device comprising an engine, an electric motor, a first clutch for connecting and disconnecting a power transmission path between the engine and the electric motor, a second clutch capable of mechanically connecting the engine and the electric motor to the drive wheels, and a gear mechanism provided between the second clutch and the drive wheels, wherein the first clutch is released and the second clutch is engaged using a dynamic second clutch command torque which has been annealed to reduce the longitudinal acceleration of the vehicle, and the vehicle is driven solely by the electric motor, the vehicle control device controls the rotational speed of the electric motor to maintain the differential rotation of the second clutch when starting the engine by controlling the first clutch toward engagement, thereby causing the second clutch to slip. The second clutch has torque characteristics that form a play-reducing region for eliminating play in the gear mechanism, If acceleration is performed while the motor is running, the rotational speed control of the motor is activated after the command input torque to the motor has passed through the backlash reduction region. The rotational speed control of the electric motor is performed on the condition that the dynamic second clutch command torque exceeds the actual transmission torque obtained from the engagement hydraulic pressure of the second clutch plus a negative margin. A vehicle control device characterized by the following features.

2. The rotational speed control of the electric motor is delayed when the static command second clutch input torque, which corresponds to the command input torque of the electric motor calculated based on the accelerator opening, is outside the play-reducing region, and the dynamic command second clutch input torque, which is obtained by annealing the static command second clutch input torque to mitigate the acceleration of the vehicle, is within the play-reducing region. A vehicle control device according to feature 1.

3. When the dynamic command second clutch input torque moves out of the play-reducing region, the rotational speed control of the electric motor is initiated. A vehicle control device according to feature 1.

Images