JP2009029261A - Vehicle driving force control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle driving force control device for achieving both suppression of shock due to change in the driving force and improvement in responsiveness of control in controlling the driving force of a vehicle. <P>SOLUTION: The vehicle driving force control device for controlling output torque of a vehicle includes a means (S102 and S103) for detecting or estimating intention of a driver, and sets a change gradient of the output torque in a predetermined region near 0 based on the detected or estimated intention of the driver (S104 to S106). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle driving force control device, and more particularly, to a vehicle driving force control device that controls a change gradient of an output torque.

  A technique for controlling the driving force (output torque) of a vehicle is known. When the driving force is controlled, a shock accompanying a change in the driving force may be a problem. For example, the driving force is controlled in a region where the driving force is close to zero. In this case, for example, when the vehicle state is switched between the driving state and the driven state, a large shock is likely to occur.

  Japanese Patent Application Laid-Open No. 2000-134713 (Patent Document 1) includes a motor / generator disposed between an engine and a wheel, a fluid power transmission device disposed between the motor / generator and the wheel, Regenerative braking torque control device having a lock-up clutch for engaging and releasing rotating members of a fluid power transmission device, and capable of generating regenerative braking torque by a motor / generator by power input from wheels In US Pat. No. 6,053,065, a lockup clutch control means for controlling the lockup clutch to a disengaged state when regenerative braking torque is generated by the motor / generator is disclosed. According to Patent Document 1, when regenerative braking torque is generated by switching from a driving state to a driven state, a part of the impact force generated in the power transmission path is absorbed or alleviated by the fluid torque transmission device. It is said that shock is suppressed.

  In Japanese Patent Laid-Open No. 2006-144650 (Patent Document 2), when a corner appears ahead while the vehicle is running, this is detected by road information detection means such as a car navigation system, and a dead zone is set or delayed with respect to the accelerator opening. The point which performs a filter process is disclosed. According to Patent Document 2 described above, it is possible to avoid a problem that the vehicle slips due to an erroneous accelerator operation or the like when traveling in a corner that is easy to slip due to freezing or the like.

JP 2000-134713 A JP 2006-144650 A

  In Patent Document 1, the way of changing the output torque when switching between the driving state and the driven state is not considered, and there is a possibility that a rapid torque change cannot be performed. When dead zone setting or delay filter processing is performed on the accelerator opening as in Patent Document 2, there is a problem that acceleration or deceleration is not performed or a response is delayed against the driver's intention.

  When controlling the driving force of a vehicle, it is desired to be able to achieve both suppression of shock accompanying change in driving force and control responsiveness.

  An object of the present invention is to provide a vehicular driving force control device capable of achieving both suppression of shock accompanying a change in driving force and control responsiveness when controlling the driving force of the vehicle.

  A vehicle driving force control device according to the present invention is a vehicle driving force control device that controls the output torque of a vehicle, and includes a means for detecting or estimating a driver's travel intention, and is a predetermined value in the vicinity of a predetermined zero. The change gradient of the output torque in the region is set based on the detected or estimated driving intention of the driver.

  In the vehicle driving force control device of the present invention, when the first control for controlling the output torque based on a traveling environment is executed, compared to the case where the first control is not executed, The absolute value of the change gradient of the output torque is set to a large value.

  In the vehicle driving force control device according to the present invention, when the second control for controlling the output torque when the shift control based on the shift operation of the driver is performed is performed, the second The absolute value of the change gradient of the output torque is set to a large value as compared with the case where the control is not executed.

  In the vehicular driving force control apparatus according to the present invention, when the second control is being executed, the absolute value of the change gradient of the output torque is greater than when the first control is being executed. It is characterized by being set to a large value.

  ADVANTAGE OF THE INVENTION According to this invention, when controlling the driving force of a vehicle, suppression of the shock accompanying the change of a driving force and control responsiveness can be made compatible.

  Hereinafter, an embodiment of a vehicle driving force control device of the present invention will be described in detail with reference to the drawings.

(First embodiment)
The first embodiment will be described with reference to FIGS. 1 to 17. The present embodiment relates to a vehicle driving force control device that controls a change gradient of output torque (driving force).

  In vehicles of the type that do not have a transmission such as the Toyota Hybrid System (THS), for example, the driving environment other than the conscious shift operation by the driver (road gradient, degree of corner bend in front of the vehicle, Control (shift point control, which will be referred to as AI-SHIFT control in the following description) for changing the shift stage of the sequential shift according to a relative positional relationship, a joint path of an automobile exclusive road, or the like is being studied.

  In the present embodiment, the engine speed, engine torque, MG1 speed, MG1 torque, so as to realize a driver-requested peller shaft torque (drive shaft torque) or driving force determined from the accelerator opening and the vehicle speed (peller shaft speed). In a hybrid system control device (power train control device with driving force demand) that determines MG2 torque, etc., when the target driving force is in a predetermined region near zero that has been determined in advance, suppression of shock accompanying changes in driving force Therefore, the change gradient of the output torque is controlled so that both control response and control response can be achieved.

  As described above, when the target driving force is controlled in a region near zero, a shock accompanying a change in driving force tends to be large. On the other hand, in order to suppress the shock, it can be considered that the change rate (change gradient) of the driving force is not set to a large value. However, a quick torque change cannot be realized simply by restricting the change rate of the driving force to a small value. For example, when the driver desires acceleration / deceleration with good response in response to an accelerator operation or the like, the driver may feel that the response is not sufficient.

  In the present embodiment, the change rate of the driving force is set according to the driver's intention to travel. As an example, when the sequential shift control (second control) is performed, the change rate of the driving force is set to a larger value than when the sequential shift control is not performed. This is because when the shift operation of the sequential shift is performed, it is estimated that the driver has a strong intention to change the output torque. In this case, it is possible to control the driving force in accordance with the driver's intention by quickly changing the torque with a large change rate of the driving force.

  In normal control of the D range where the sequential shift control is not executed (in the state where the shift position is the D range and the AI-SHIFT control is not executed), priority is given to the reduction of the shock accompanying the change in the driving force. In addition, the change rate of the driving force is set to a small value. Thereby, for example, when the positive / negative of the driving force is switched, that is, when the driving state and the driven state are switched, the occurrence of a shock is suppressed and the drivability is improved. In the following description, switching between a driving state and a driven state is referred to as a zero cross (torque). The detailed contents of the AI-SHIFT control will be described later.

  In the present embodiment, when AI-SHIFT control (first control) is executed, the change rate of the driving force is the change rate when the sequential shift control is executed, and the normal range of the D range. It is a value between the change rates in the control of (see FIG. 17 described later). In the AI-SHIFT control, a change speed of the driving force can be ensured while moderately suppressing a shock accompanying the change of the driving force.

  With the control according to the present embodiment, a target torque (at the time of zero crossing) suitable for each control such as AI-SHIFT control and sequential shift control can be set. This realizes both improvement of drivability and improvement of responsiveness by suppressing the shock.

The configuration of the present embodiment is premised on the following configurations (1) and (2).
In the control realized by diverting the sequential shift control for HV in realizing the AI-SHIFT control for HV,
(1) The change rate is set separately when the torque is zero crossing. (2) The change rate when the torque is zero crossing is set separately according to each control, such as during AI-SHIFT control and sequential shift control.

  FIG. 9 is a configuration diagram showing an outline of the configuration of the hybrid vehicle 20 equipped with the vehicle driving force control device as one embodiment of the present invention. The hybrid vehicle 20 according to the present embodiment includes an engine 22, a three-shaft power distribution and integration mechanism 30 connected to a crankshaft 26 as an output shaft of the engine 22 via a damper 28, A motor MG1 capable of generating electricity connected to the distribution integration mechanism 30, a reduction gear 35 attached to a ring gear shaft 32a as a drive shaft connected to the power distribution integration mechanism 30, and a motor MG2 connected to the reduction gear 35 And a hybrid electronic control unit 70 for controlling the entire vehicle driving force control device.

  The engine 22 is an internal combustion engine that outputs power using a hydrocarbon-based fuel such as gasoline or light oil, and an engine electronic control unit (hereinafter referred to as an engine ECU) that receives signals from various sensors that detect the operating state of the engine 22. ) 24 is subjected to operation control such as fuel injection control, ignition control, intake air amount adjustment control and the like. The engine ECU 24 is in communication with the hybrid electronic control unit 70, controls the operation of the engine 22 by a control signal from the hybrid electronic control unit 70, and, if necessary, transmits data related to the operating state of the engine 22 to the hybrid electronic control. Output to unit 70.

  The power distribution and integration mechanism 30 includes an external gear sun gear 31, an internal gear ring gear 32 arranged concentrically with the sun gear 31, a plurality of pinion gears 33 that mesh with the sun gear 31 and mesh with the ring gear 32, A planetary gear mechanism is provided that includes a carrier 34 that holds a plurality of pinion gears 33 so as to rotate and revolve, and that performs differential action using the sun gear 31, the ring gear 32, and the carrier 34 as rotational elements.

  In the power distribution and integration mechanism 30, the crankshaft 26 of the engine 22 is connected to the carrier 34, the motor MG1 is connected to the sun gear 31, and the reduction gear 35 is connected to the ring gear 32 via the ring gear shaft 32a. When functioning as a generator, power from the engine 22 input from the carrier 34 is distributed according to the gear ratio between the sun gear 31 side and the ring gear 32 side, and when the motor MG1 functions as an electric motor, the engine input from the carrier 34 The power from 22 and the power from the motor MG1 input from the sun gear 31 are integrated and output to the ring gear 32 side. The power output to the ring gear 32 is finally output from the ring gear shaft 32a to the drive wheels 63a and 63b of the vehicle via the gear mechanism 60 and the differential gear 62.

  The motor MG1 and the motor MG2 are both configured as well-known synchronous generator motors that can be driven as generators and can be driven as motors, and exchange power with the battery 50 via inverters 41 and 42. The power line 54 connecting the inverters 41 and 42 and the battery 50 is configured as a positive electrode bus and a negative electrode bus shared by the inverters 41 and 42, and the electric power generated by one of the motors MG1 and MG2 It can be consumed by a motor. Therefore, battery 50 is charged / discharged by electric power generated from one of motors MG1 and MG2 or insufficient electric power. If the balance of electric power is balanced by the motors MG1 and MG2, the battery 50 is not charged / discharged.

  The motors MG1 and MG2 are both driven and controlled by a motor electronic control unit (hereinafter referred to as a motor ECU) 40. The motor ECU 40 detects signals necessary for driving and controlling the motors MG1 and MG2, such as signals from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and current sensors (not shown). The phase current applied to the motors MG1 and MG2 to be applied is input, and a switching control signal to the inverters 41 and 42 is output from the motor ECU 40. The motor ECU 40 is in communication with the hybrid electronic control unit 70, controls the driving of the motors MG1 and MG2 by a control signal from the hybrid electronic control unit 70, and, if necessary, data on the operating state of the motors MG1 and MG2. Output to the hybrid electronic control unit 70.

  The battery 50 is managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 52. The battery ECU 52 receives signals necessary for managing the battery 50, for example, a voltage between terminals from a voltage sensor (not shown) installed between terminals of the battery 50, and a power line 54 connected to the output terminal of the battery 50. The charging / discharging current from the attached current sensor (not shown), the battery temperature Tb from the temperature sensor 51 attached to the battery 50, and the like are input. Output to the control unit 70. The battery ECU 52 also calculates the remaining capacity (SOC) based on the integrated value of the charge / discharge current detected by the current sensor in order to manage the battery 50.

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72, and in addition to the CPU 72, a ROM 74 for storing processing programs, a RAM 76 for temporarily storing data, an input / output port and communication not shown. And a port. The hybrid electronic control unit 70 includes an ignition signal from an ignition switch 80, a shift position SP from a shift position sensor 82 that detects the operation position of the shift lever 81, and an accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83. The accelerator pedal opening Acc from the vehicle, the brake pedal position BP from the brake pedal position sensor 86 for detecting the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88, and the like are input via the input port.

  As described above, the hybrid electronic control unit 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52. ing.

  The hybrid vehicle 20 according to the first embodiment configured as described above is required torque to be output to the ring gear shaft 32a as the drive shaft based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal 83 by the driver. The engine 22, the motor MG1, and the motor MG2 are controlled so that the required power corresponding to the required torque is output to the ring gear shaft 32a.

  The operation control of the engine 22, the motor MG1, and the motor MG2 includes a torque conversion operation mode, a charge / discharge operation mode, a motor operation mode, and the like.

  In the torque conversion operation mode, the operation of the engine 22 is controlled so that the power corresponding to the required power is output from the engine 22, and all of the power output from the engine 22 is performed by the power distribution and integration mechanism 30, the motor MG1, and the motor MG2. In this operation mode, the motor MG1 and the motor MG2 are driven and controlled so that torque is converted and output to the ring gear shaft 32a.

  In the charge / discharge operation mode, the engine 22 is operated and controlled so that the power corresponding to the sum of the required power and the power necessary for charging / discharging the battery 50 is output from the engine 22, and the engine 22 is charged and discharged with the battery 50. The motor MG1 and the motor MG2 are driven and controlled so that the required power is output to the ring gear shaft 32a with the torque conversion by the power distribution / integration mechanism 30, the motor MG1 and the motor MG2. It is an operation mode.

  The motor operation mode is an operation mode in which the operation of the engine 22 is stopped and operation is controlled so that power corresponding to the required power from the motor MG2 is output to the ring gear shaft 32a.

  In the present embodiment, when the shift lever 81 is operated to the D (drive) range or the R (reverse) range, the above-described torque conversion operation mode, charge / discharge operation mode, motor, and the like are based on the efficiency of the engine 22 and the state of the battery 50. When the engine 22 or the motors MG1 and MG2 are operated in any one of the operation modes, and the shift lever 81 is operated to the B (brake) range, the operation in the motor operation mode is performed so that braking by the engine brake is performed. The engine 22 and the motors MG1 and MG2 are operated in either the torque conversion operation mode or the charge / discharge operation mode other than the motor operation mode.

  That is, the engine 22 is stopped in the D range and the R range, but the engine 22 is not stopped in the B range. The stop of the operation of the engine 22 when the shift lever 81 is operated to the D range is required for the entire vehicle as the sum of the required power of the ring gear shaft 32a as the drive shaft and the power required for charging and discharging of the battery 50. This is performed when the motive power is less than a predetermined motive power that defines a range in which the engine 22 can be operated efficiently.

  Next, the operation of this embodiment will be described with reference to FIG.

  In the following, in a hybrid vehicle, a driver's conscious shift operation based on the driving environment (road gradient, degree of corner bend in front of the vehicle, relative positional relationship with the vehicle in front, a joint path of a car road, etc.) A description will be given of the control realized by using the hybrid sequential shift control technique when control other than the above is performed (shift point control, AI-SHIFT control).

[Step S001]
First, in step S001, the accelerator opening PAP and the vehicle speed (peller shaft rotation speed) are read.

[Step S002]
Next, in step S002, the peller shaft torque required by the driver (drive shaft torque), that is, the driver required peller shaft torque (drive shaft torque) is calculated. For example, referring to a map as shown in FIG. 2, based on the accelerator opening PAP read in step S001 and the vehicle speed (peller shaft rotation speed), the driver requested peller shaft torque (driving force (target peller torque) )) Is calculated.

[Step S003]
Next, in step S003, the power required by the driver (driver required power) and the engine speed required by the driver (driver required engine speed) are calculated.

  The driver request power is calculated based on the driver request peller shaft torque calculated in step S002 and the peller shaft rotation speed read in step S001. Here, driver required power = driver required peller shaft torque × peller shaft rotation speed.

  The driver request engine speed is calculated based on the fuel efficiency optimal line 301 with reference to a map as shown in FIG. When the driver request power is P1, the driver request engine speed is NE1.

[Step S004]
Next, in step S004, a target shift speed required by the driver (driver required target shift speed) is calculated. For example, referring to a map as shown in FIG. 4, the accelerator opening PAP and vehicle speed (peller shaft rotation speed) read in step S001 and the driver request peller shaft torque calculated in step S002 are calculated. Based on this, the driver-requested target gear position is determined.

  In step S004, the method for calculating the driver-requested target shift speed is not limited to the method using FIG. For example, the gear ratio is calculated based on the driver-requested engine speed calculated in step S003 and the peller shaft speed read in step S001, and the map of FIG. Based on the above, the driver-requested target shift speed can be determined.

  In step S004, in addition to the method using FIG. 4 or FIG. 8, a method using the map of FIG. 5 may be used. FIG. 5 shows the lower limit engine speed of each gear stage. With reference to the map of FIG. 5, the driver-requested target gear position is determined based on the driver-requested engine speed calculated in step S003 and the vehicle speed (peller shaft speed) read in step S001. Can be done. In FIG. 5, reference numeral 401 denotes a region where the driver-requested target gear stage is the first speed, 402 denotes the second speed region, 403 denotes the third speed region, 404 denotes the fourth speed region, 405 denotes the fifth speed region, Reference numeral 406 denotes the sixth speed region.

[Step S005]
Next, in step S005, a regulation shift stage for shift point control such as uphill / downhill control, corner control, inter-vehicle distance control, joint flow path control, etc. is read (if the sequential shift control is performed, the shift stage Hereinafter, description of the operation when the sequential shift control is performed is omitted). For example, when uphill / downhill control is performed, a restriction shift speed is determined with reference to a map as shown in FIG. FIG. 11 describes a target shift speed corresponding to the road gradient θ, and the regulation shift speed is a shift speed that is one speed higher than the target speed. Similarly, for example, when corner control is performed, a restriction shift speed is determined with reference to a map as shown in FIG. When the inter-vehicle distance control is performed, a map as shown in FIG. 13 is referred to and the regulation shift speed is determined. Each of FIGS. 12 and 13 shows a target shift speed, and the regulation shift speed is a shift speed that is one speed higher than the target speed.

[Step S006]
Next, in step S006, it is determined whether or not the driver-requested target shift speed is equal to or greater than the speed limit control shift speed determined in step S005. If the result of the determination is affirmative, the process proceeds to step S007, and if not, the process proceeds to step S008.

[Step S007]
In step S007, the shift speed is regulated by reflecting the shift speed of the shift point control in the driver requested target shift speed. In this step S007, the driver requested peller shaft torque (drive shaft torque) Tp * and the driver requested engine speed Ne * are changed.

  As shown in FIG. 6, the driver request peller shaft torque (drive shaft torque) Tp * is changed. That is, referring to the map of FIG. 6, for example, when the speed limit control shift speed obtained in step S005 is 4th and the vehicle speed (peller shaft rotation speed) is S1, the driver requested peller shaft Torque Tp * is changed to T1.

  Further, as shown in FIG. 5, the driver request engine speed Ne * is changed. For example, when the vehicle speed (peller shaft rotation speed) is S1, the lower limit engine rotation speed NeL * is changed to NE2.

[Step S008]
In step S008, engine torque Te *, MG1 rotation speed Nm1 *, target MG1 torque Tm1 *, and target MG2 torque Tm2 * are calculated. The calculation method will be described in detail below.

  In step S007, the target rotational speed Ne * and the target peller shaft torque Tp * of the engine 22 are set. When Ne * ≦ NeL *, if Ne * = NeL *, then Tp * × Np = Te **. Since Ne *, Te * = Tp * × Np / Ne * (Np is the rotation speed of the peller shaft). Then, using the set target rotational speed Ne *, the rotational speed Nr of the ring gear shaft 32a (= conversion coefficient k · vehicle speed V), and the gear ratio ρ of the power distribution and integration mechanism 30, the target of the motor MG1 is expressed by the following equation (1). The rotational speed Nm1 * is calculated, and the torque command Tm1 * of the motor MG1 is calculated by the following equation (2) based on the calculated target rotational speed Nm1 * and the current rotational speed Nm1 of the motor MG1.

  FIG. 10 is a collinear diagram showing the dynamic relationship between the rotational speed and torque of each rotating element of the power distribution and integration mechanism 30. In the figure, the left S-axis indicates the rotational speed of the sun gear 31, the C-axis indicates the rotational speed of the carrier 34, and the R-axis indicates the rotational speed Nr of the ring gear 32 (ring gear shaft 32a). Since the rotational speed of the sun gear 31 is the rotational speed Nm1 of the motor MG1 and the rotational speed of the carrier 34 is the rotational speed Ne of the engine 22, the target rotational speed Nm1 * of the motor MG1 is the rotational speed Nr of the ring gear shaft 32a (= k · V), the target rotational speed Ne * of the engine 22 and the gear ratio ρ of the power distribution and integration mechanism 30 can be calculated by the equation (1).

  Therefore, the engine 22 can be rotated at the target rotational speed Ne * by setting the torque command Tm1 * so that the motor MG1 rotates at the target rotational speed Nm1 * and drivingly controlling the motor MG1. Here, Expression (2) is a relational expression in feedback control for rotating the motor MG1 at the target rotational speed Nm1 *. In Expression (2), “KP” in the second term on the right side is a gain of a proportional term. Yes, “KI” in the third term on the right side is the gain of the integral term.

  Note that the two thick arrows on the R axis in FIG. 10 indicate that the torque Te * output from the engine 22 when the engine 22 is steadily operated at the operation point of the target rotational speed Ne * and the target torque Te * is the ring gear shaft 32a. The torque transmitted to the motor and the torque Tm2 * output from the motor MG2 acts on the ring gear shaft 32a.

Nm1 * = (Ne * ・ (1 + ρ) −k ・ V) / ρ (1)
Tm1 * = previous Tm1 * + KP (Nm1 * −Nm1) + KI∫ (Nm1 * −Nm1) dt (2)

  When the target rotational speed Nm1 * of the motor MG1 and the torque command Tm1 * are calculated, the required torque Tr *, the torque command Tm1 *, the gear ratio ρ of the power distribution and integration mechanism 30, and the gear ratio Gr of the reduction gear 35 are requested. A temporary motor torque Tm2tmp as a torque to be output from the motor MG2 in order to apply the torque Tr * to the ring gear shaft 32a is calculated by the following equation (3) determined from the torque balance relationship of the nomograph of FIG. Based on the 50 input / output limits Win, Wout, the torque command Tm1 * of the motor MG1, the current rotational speed Nm1 of the motor MG1, and the rotational speed Nm2 of the motor MG2, the following formula (4) and the following formula (5) Torque limits Tm2min and Tm2max as upper and lower limits of torque that may be output from Set the smaller the variable T of the Tm2tmp and the calculated torque limit Tm2max, sets a larger one of this variables T and the torque limit Tm2min the torque command Tm2 * of the motor MG2. Thereby, torque command Tm2 * of motor MG2 can be set as a torque limited within the range of input / output limits Win and Wout of battery 50.

Tm2tmp = (Tr * + Tm1 * / ρ) / Gr (3)
Tm2min ＝ (Win−Tm1 * ・ Nm1) / Nm2 （４）
Tm2max ＝ (Wout−Tm1 * ・ Nm1) / Nm2 (5)

  Thus, when the target engine speed Ne *, the target torque Te *, and the torque commands Tm1 *, Tm2 * of the motors MG1, MG2 are set, the target engine speed Ne * and the target torque Te * of the engine 22 are set in the engine ECU 24. The torque commands Tm1 * and Tm2 * for the motors MG1 and MG2 are transmitted to the motor ECU 40, and the drive control routine is terminated.

  The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te * performs fuel injection control in the engine 22 such that the engine 22 is operated at an operating point indicated by the target rotational speed Ne * and the target torque Te *. Controls such as ignition control. Further, the motor ECU 40 that has received the torque commands Tm1 * and Tm2 * controls the switching elements of the inverters 41 and 42 so that the motor MG1 is driven by the torque command Tm1 * and the motor MG2 is driven by the torque command Tm2 *. To do.

  As described above, according to the present embodiment, the engine speed and the engine torque are set so as to realize the driver required peller shaft torque (drive shaft torque) or the driving force determined from the accelerator opening PAP and the vehicle speed (peller shaft speed). In the driving force control system (HV system) that determines the MG1 rotational speed, MG1 torque, MG2 torque, etc., the target engine rotational speed (step S003) determined from the driver required peller shaft torque (FIG. 2, step S002) and the peller shaft A driver-requested target gear stage (target gear ratio, step S004) is determined from the rotation speed.

  Further, the driver requested target shift speed is determined from the accelerator opening, the vehicle speed (peller shaft rotation speed), and the driver requested peller shaft torque (see FIG. 4). Alternatively, the gear ratio is calculated from the driver-requested engine speed and the peller shaft speed, and the driver-requested target gear stage is determined from the gear ratio (see FIG. 8). Shift point control such as uphill / downhill control, corner control, and inter-vehicle distance control is reflected in the target shift stage (step S007).

  Further, for each target gear stage (target gear ratio), a peller shaft torque (drive shaft torque) or driving force and an engine speed lower limit guard are installed (FIGS. 5 and 6), and the target gear stage (target gear ratio) is set. Reflecting the shift stage control (speed ratio control) of shift point control such as uphill / downhill control, the target peller shaft torque and the target engine speed are changed (step S007), and the target engine torque, the target MG1 speed, and the target MG1 torque are changed. Then, the target MG2 torque is calculated (step S008).

  According to the above, the following effects can be obtained.

(1) Shift point control that has been developed for a conventional automatic transmission can be easily deployed to a hybrid system control device (power train control device with driving force demand) to improve drivability. it can.

(2) When the accelerator is stepped on at the time of reacceleration after the shift point control is performed, the acceleration response is improved because the engine speed is increased from a high level. The effect (2) will be described below with reference to FIG.

  First, when the automatic transmission is in the D range, it is assumed that the target gear position of the shift point control is 4th speed (step S004 in FIG. 1). Thereafter, in step S007, the driver-requested peller shaft torque is changed to the target gear position (fourth speed). In this case, when there is no lower limit engine speed (engine speed guard) 420, the point changes from the D range point 421 to the 4th speed point 422. At the time of re-acceleration from the fourth speed point 422, the acceleration response is poor because the acceleration is from a low engine speed. Since the engine speed at the point 422 is the same as the engine speed at the point 421 (eg, 1000 rpm), the acceleration response at the time of reacceleration is poor.

  On the other hand, in this embodiment, since there is a lower limit engine speed (engine speed guard) 420 (step S007), the first point 421 is the lower limit engine on the point 422 and the equal power line 430 by the shift control. The point changes to a guarded point 423 at the rotation speed 420. When the accelerator is stepped on at the time of re-acceleration, the acceleration response is improved because the acceleration starts from the point 423 where the engine speed is higher than the point 422.

  In the present embodiment, in the hybrid system control device that executes the AI-SHIFT control and the sequential shift control, a target torque is determined in advance in order to achieve both suppression of shock accompanying change in driving force and control responsiveness. The rate of change of the driving force in the predetermined region near zero is changed according to the control being performed. FIG. 14 is a diagram for explaining the control contents and the effects of the present embodiment. FIG. 17 is a diagram for explaining the upper limit value (rate limit) of the change rate of the driving force set according to the control content in the present embodiment.

  In FIG. 14, reference numeral 103 indicates a transition of the target torque when the sequential shift control is performed. Reference numeral 104 indicates a transition of the target torque when the AI-SHIFT control is performed. FIG. 14 shows a state in which the target torques 103 and 104 change with a zero crossing from the value indicated by the symbol T2 to the value indicated by the symbol T3. The value indicated by the symbol T3 is, for example, a driver-requested peller shaft torque (drive shaft torque) calculated in sequential shift control or AI-SHIFT control. The minimum target torque). Note that the values indicated by the symbols T2 and T3 are values in a predetermined area near zero that is determined in advance.

  Reference numeral 101 indicates the transition of the front and rear G when the sequential shift control is performed. Reference numeral 102 indicates the transition of the front and rear G when the AI-SHIFT control is performed.

  In the present embodiment, the target driving force is gradually changed so that the rate of change when the driving force is changed does not exceed a predetermined rate limit. As shown in FIG. 17, the size of the rate limit is set according to each control. As shown in FIG. 17, when the sequential shift control is executed, when the AI-SHIFT control is executed, the rate limit magnitude is the normal control of the D range (the shift position is the D range, the AI -Control when SHIFT control is not executed) is set to be a smaller value in the order of execution. The reason will be described below with reference to FIG.

  Here, the rate limit having a large value means that the driving force can be changed more greatly within a predetermined time when the driving force is increased or decreased. When increasing the driving force, the larger the rate limit, the larger the rate of increase of the driving force is set. When decreasing the driving force, the higher the rate limit, the higher the rate limit. The reduction rate of the driving force is set to a large value. In the same control, the magnitude of the rate limit when increasing the driving force and the magnitude of the rate limit when decreasing the driving force can be different values.

  Since the rate limit is set as shown in FIG. 17, the target torque 103 when the sequential shift control is performed is compared with the target torque 104 when the AI-SHIFT control is performed as shown in FIG. 14. The value changes at a large rate of change. As a result, the target torque 103 can quickly change to the minimum target torque T3. Since the torque change rate is a large value, the front and rear G101 when the sequential shift control is performed greatly change before and after time t1 when the target torque 103 crosses zero. As described above, although the shock accompanying the change in the driving force becomes relatively large, when the sequential shift control is performed, the driver's intention to change the output torque is strong, and thus the shock is easily tolerated.

  The change rate of the target torque 104 when the AI-SHIFT control is performed is smaller than the change rate of the target torque 103 when the sequential shift control is performed. Thereby, the change before and after G102 when the AI-SHIFT control is performed is relatively small before and after time t2 when the target torque 104 when the AI-SHIFT control is performed crosses zero. Therefore, torque control can be performed while the shock accompanying the change in driving force is suppressed.

  In the AI-SHIFT control, the driving force is controlled based on the traveling environment. In this case, in order to enhance the control effect, it is desirable to change the target torque 104 at a certain rate of change. In addition, since the driving environment is recognized by the driver, it is considered that when the driving force is changed according to the driving environment, even if there is a slight shock due to the change of the driving force, it is likely to be accepted. . If control of the driving force is executed using the driver's intention to travel (for example, accelerator OFF) as a trigger condition, a shock associated with a change in the driving force is more easily accepted. The rate limit in the AI-SHIFT control can be set so as to appropriately balance the suppression of shock and the control effect (responsiveness).

  Although not shown, in normal control of the D range (control when the shift position is the D range and the AI-SHIFT control is not executed), the target torque when the AI-SHIFT control is performed Compared to the change rate of 104, the target torque changes at a smaller change rate. Thereby, the shock accompanying the change in driving force can be further suppressed.

  The operation of this embodiment will be described with reference to FIG.

  In step S101, rate limit calculation processing other than the rate limit calculated in steps S104 to S106 described later is performed. In step S104 to step S106, a rate limit considering drivability is calculated based on the shift state, the degree of separation of the target torque from zero, and the like. In step S101, a rate limit based on other elements is calculated. For example, the rate limit set in the exception handling at the time of fail-safe in hardware is calculated.

  Further, the rate limit can be set based on the remaining capacity SOC of the battery 50. When the output torque is changed, regeneration may be performed by the motors MG1 and MG2. For example, regeneration by shifting may be performed during upshifting. The electric power generated by the regeneration is charged in the battery 50. However, when the battery 50 is fully charged, the battery 50 cannot be charged. In this case, since the regeneration is not possible, the rate limit is limited. When the rate limit calculation process is performed in step S101, the process proceeds to step S102.

  In step S102, it is determined whether sequential shift control is being performed. It is determined whether or not the sequential shift control based on the shift operation of the sequential shift by the driver is performed. As a result of the determination, if it is determined that the sequential shift control is being performed (step S102-Y), the process proceeds to step S106, and if not (step S102-N), the process proceeds to step S103.

  In step S103, it is determined whether or not AI-SHIFT control is being performed. As a result of the determination, if it is determined that the AI-SHIFT control is being performed (step S103-Y), the process proceeds to step S105, and if not (step S103-N), the process proceeds to step S104.

  In step S104, a rate limit is calculated. At the time of torque down at which the target torque decreases, a torque down rate limit tpup0x is calculated. The situation in which the target torque decreases includes when the accelerator opening decreases or when an upshift is performed. When the minimum target torque to be output is smaller than the current target torque, the target torque is gradually reduced toward the minimum target torque. The change rate (decrease rate) of the target torque at this time is set to the torque-down rate limit tup0x. In the example shown in FIG. 14, the current target torque is a value indicated by a symbol T2, and the minimum target torque is a value indicated by a symbol T3. From the current target torque T2 to the minimum target torque T3, the target torque is gradually reduced based on the torque-down rate limit tpup0x set according to each control.

  The torque-down rate limit tpup0x is calculated based on the shift state (gear stage or speed ratio and the amount of change thereof) and the degree of separation of the target torque from the torque 0 (the magnitude of the absolute value of the target torque). . For example, the map shown in FIG. 16 is referred to calculate the torque-down rate limit tpup0x. The map shown in FIG. 16 is set for a predetermined shift state (D range in step S104). As shown in FIG. 16, the torque-down rate limit tpup0x is set based on the degree of separation from the torque 0 (Nm) in the target torque.

  When the target torque is a value close to torque 0, the torque-down rate limit tup0x is set to a smaller value than when the target torque is further away from torque 0. Thereby, the magnitude of the shock accompanying the change in driving force that is likely to occur in the vicinity of the torque 0 is reduced. For example, when the target torque 103, 104 (see FIG. 14) crosses zero (see times t1, t2) when the driving state is switched to the driven state, the target torque 103, 104 changes gently, and thus the driving force changes. The shock associated with is suppressed. When the target torques 103 and 104 further decrease after the zero crossing, the torque-down rate limit tpup0x increases as the distance from the torque 0 increases, and the target torques 103 and 104 quickly become the minimum target torque T3. Can be lowered towards.

  On the other hand, when the target torque increases, the torque-up rate limit tpdn0x is calculated. The situation in which the target torque is increased includes when the accelerator opening is increased or when a downshift is performed. The target torque to be output is a large value with respect to the current target torque, and the target torque is gradually increased toward the maximum target torque. The rate of change (increase rate) of the target torque at this time is set to the torque-up rate limit tpdn0x. The calculation method of the torque up rate limit tpdn0x is the same as the torque down rate limit tpup0x. When the target torque is a value close to torque 0, the torque-up rate limit tpdn0x is set to a smaller value than when the target torque is further away from torque 0. When the torque-down rate limit tpup0x or the torque-up rate limit tpdn0x is calculated in step S104, the process proceeds to step S107.

  In step S105, the torque-down rate limit tpup0x or the torque-up rate limit tpdn0x in the AI-SHIFT control is calculated. The calculation method of the torque-down rate limit tpup0x or the torque-up rate limit tpdn0x is the same as in step S104, but the magnitude (constant in the map) of the rate limit set in the map (see FIG. 16) is Different from step S104. As described above with reference to FIG. 17, the rate limit in the AI-SHIFT control is set to a larger value than the rate limit in the normal control of the D range.

  In the AI-SHIFT control, a plurality of rate limit maps as shown in FIG. 16 can be provided according to the state of each shift. In this case, even if the degree of separation of the target torque from the torque 0 is the same, the rate limit can be set to a different value depending on the shift state. When the torque-down rate limit tpup0x or the torque-up rate limit tpdn0x in the AI-SHIFT control is calculated in step S105, the process proceeds to step S107.

  In step S106, the torque-down rate limit tpup0x or the torque-up rate limit tpdn0x in the sequential shift control is calculated. The calculation method of the torque-down rate limit tpup0x or the torque-up rate limit tpdn0x is the same as in step S104 and step S105, but the magnitude of the rate limit (constant in the map) set in the map (see FIG. 16). ) Is different from the case of step S104 and step S105. As described above with reference to FIG. 17, the rate limit in the sequential shift control is set to a larger value than the rate limit in the AI-SHIFT control and the normal control of the D range.

  In the sequential shift control, a plurality of rate limit maps as shown in FIG. 16 can be provided according to the state of each shift. In this case, even if the degree of separation of the target torque from the torque 0 is the same, the rate limit can be set to a different value depending on the shift state. When the torque-down rate limit tpup0x or the torque-up rate limit tpdn0x in the sequential shift control is calculated in step S106, the process proceeds to step S107.

  In step S107, the rate limit arbitration process calculated in steps S101, S104, S105, and S106, respectively, is performed. The torque-down rate limit tup0x or the torque-up rate limit tpdn0x is determined by the minimum selection of the rate limit calculated in each step.

  For example, the case where the sequential shift control is being executed will be described as an example. At the time of torque reduction, the rate limit calculated at step S101 (at the time of torque down) and the rate limit tup0x at the time of torque reduction calculated at step S106 The final torque-down rate limit tpup is determined by the minimum selection. At the time of torque increase, the final torque increase rate limit tpdn is determined by the minimum selection of the rate limit calculated at step S101 (at the time of torque increase) and the torque increase rate limit tpdn0x calculated at step S106. Is done.

  Next, in step S108, the rate limit adjusted in step S107 is reflected as a control amount. When the torque is reduced, the target torque tptrg is calculated based on the final torque-down rate limit tpup determined in step S107. On the other hand, at the time of torque increase, the target torque tptrg is calculated based on the final torque increase rate limit tpdn determined in step S107. When step S108 is executed, this control flow ends.

  According to the present embodiment, when the driving force is controlled, the rate of change (rate limit) of the driving force is set to a different value depending on the control content in a predetermined region near zero that is determined in advance (step). S102 to S106). The change rate of the driving force is set to the largest value when the sequential shift control is executed (step S106), and when the AI-SHIFT control is executed (step S105), the normal control of the D range is performed. The change rates are set as small values in the order of execution (step S104).

  When the sequential shift control is being executed, the driving force changes at a large change rate, so that the control responsiveness is further improved. When normal control of the D range is being performed, priority is given to reducing shocks associated with changes in driving force. Further, when AI-SHIFT control is executed, the rate of change in driving force is set to a value between sequential shift control and normal control of the D range, so that shock suppression and control effects are achieved. It is possible to control with an appropriate balance.

  According to the present embodiment, since the rate limit is set according to the control content (driving intention of the driver), the shock level and the response can be tuned according to each control content. When controlling the driving force of the vehicle, it is possible to achieve both suppression of shock accompanying change in driving force and control responsiveness.

  In the present embodiment, the case where the driving force of the vehicle on which the hybrid system control device is mounted is controlled is described as an example. However, the vehicle and the control system to be controlled by the driving force are not limited to this.

It is a flowchart which shows operation | movement of 1st Embodiment of the driving force control apparatus for vehicles of this invention. 4 is a map for calculating a driver request peller shaft torque in the first embodiment of the vehicle driving force control apparatus of the present invention. 5 is a map for calculating a driver request engine speed in the first embodiment of the vehicle driving force control apparatus of the present invention. In the first embodiment of the vehicle driving force control apparatus of the present invention, it is a map for calculating the driver's required shift stage. In the first embodiment of the vehicle driving force control device of the present invention, it is another map for calculating the driver requested gear. It is a figure which shows the example of the target peller torque at the time of gear stage regulation in 1st Embodiment of the vehicle driving force control apparatus of this invention. It is a figure for demonstrating the effect of 1st Embodiment of the driving force control apparatus for vehicles of this invention. In the first embodiment of the vehicle driving force control device of the present invention, it is another map for calculating the driver requested gear. 1 is a block diagram showing a schematic configuration of a first embodiment of a vehicle driving force control device of the present invention. In 1st Embodiment of the vehicle driving force control apparatus of this invention, it is an alignment chart of a power distribution integration mechanism. In the first embodiment of the vehicle driving force control apparatus of the present invention, it is a map showing the relationship between the road gradient and the target shift stage. In 1st Embodiment of the vehicle driving force control apparatus of this invention, it is a map which shows the target gear stage according to the curve degree of a corner. In the first embodiment of the vehicle driving force control apparatus of the present invention, it is a map showing the shift stage according to the relative positional relationship with the preceding vehicle. It is a figure for demonstrating the control content and effect of 1st Embodiment of the vehicle driving force control apparatus of this invention. It is another flowchart which shows operation | movement of 1st Embodiment of the driving force control apparatus for vehicles of this invention. 5 is a map showing a rate limit according to the magnitude of torque in the first embodiment of the vehicle driving force control apparatus of the present invention. In 1st Embodiment of the vehicle driving force control apparatus of this invention, it is a map which shows the relationship between control content and a rate limit.

Explanation of symbols

20 Hybrid vehicle 22 Engine 24 Engine ECU
26 Crankshaft 28 Damper 30 Power Distribution Integration Mechanism 31 Sun Gear 32 Ring Gear 32a Ring Gear Shaft 33 Pinion Gear 34 Carrier 35 Reduction Gear 40 Motor ECU
41 Inverter 42 Inverter 43 Rotation Position Detection Sensor 44 Rotation Position Detection Sensor 50 Battery 51 Temperature Sensor 52 Battery ECU
54 Power Line 60 Gear Mechanism 62 Differential Gear 63a Drive Wheel 63b Drive Wheel 70 Electronic Control Unit for Hybrid 72 CPU
74 ROM
76 RAM
80 Ignition switch 81 Shift lever 82 Shift position sensor 83 Accelerator pedal 84 Accelerator pedal position sensor 85 Brake pedal 88 Vehicle speed sensor BP Brake pedal position tpup0x Torque-down rate limit tpdn0x Torque-up rate limit tpup Final torque-down rate limit tpdn Final torque-up rate limit tptrg Target torque

Claims (4)

A vehicle driving force control device for controlling an output torque of a vehicle,
A means for detecting or estimating the driver's driving intention,
The vehicular driving force control device, wherein a change gradient of the output torque in a predetermined region near 0 that is determined in advance is set based on the detected or estimated driving intention of the driver. The vehicle driving force control device according to claim 1,
When the first control for controlling the output torque based on the driving environment is executed, the absolute value of the change gradient of the output torque is larger than when the first control is not executed. The vehicle driving force control device is characterized by being set to a value. In the vehicle driving force control device according to claim 1 or 2,
When the second control for controlling the output torque when the shift control based on the shift operation of the driver is performed is performed, compared with the case where the second control is not performed. The absolute value of the change gradient of the output torque is set to a large value. In the vehicle driving force control device according to claim 3,
When the second control is executed, the absolute value of the change gradient of the output torque is set to a larger value than when the first control is executed. Vehicle driving force control device.

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