JP2011126425A - Vehicle control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle control system suppressing a driver from feeling uncomfortable. <P>SOLUTION: The vehicle control system includes: an acceleration generation device (an engine 4, a lockup clutch 51; an automatic transmission 52) generating acceleration on a vehicle; and an ECU 6 controlling the acceleration generation device based on an accelerator opening Pa in response to operation of an accelerator by a driver and a vehicle speed v. The ECU 6 controls the engine 4 based on requested acceleration based on the accelerator opening Pa and the vehicle speed v, and controls the lockup clutch 51 and the automatic transmission 52 based on a target clutch state Lo and a target transmission gear ratio γo based on the accelerator opening Pa and the vehicle speed v. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vehicle control system.

  In recent vehicle control, for example, as disclosed in Patent Document 1, the driver's request is based on the vehicle speed and the accelerator operation amount (accelerator opening, pedal effort, etc.) when the driver operates the accelerator pedal. A so-called torque demand control that determines a target acceleration that is an acceleration to be generated and controls an acceleration generating device that generates acceleration in the vehicle based on the determined target acceleration, for example, an engine throttle opening, a fuel injection amount, an ignition timing, etc. Has been done.

JP-A-63-025342

  In a vehicle control system that performs torque demand control, not only the power source such as the engine is controlled based on the required value corresponding to the acceleration generated in the vehicle, but also the automatic control is performed to achieve the acceleration corresponding to the required value. The transmission was also controlled based on the required value. In a vehicle control system that performs torque demand control, there is a concern that the driver may feel uncomfortable due to control of the power source and the automatic transmission based on the required values.

  Therefore, the present invention has been made in view of the above, and an object of the present invention is to provide a vehicle control system that can suppress the driver from feeling uncomfortable.

  In order to solve the above-described problems and achieve the object, the present invention is based on an acceleration generating device that generates acceleration in a vehicle, an accelerator operation amount according to an accelerator operation by a driver, and a vehicle speed of the vehicle. A vehicle control system that controls the acceleration generator, wherein the acceleration generator includes a power source, and an automatic transmission provided between the power source and the drive wheels of the vehicle. The vehicle control device controls the power source based on a required value corresponding to the acceleration based on the accelerator operation amount and the vehicle speed, and sets a target speed ratio based on the accelerator operation amount. The automatic transmission is controlled based on the above.

  In the vehicle control system, it is preferable that the target gear ratio is based on the accelerator operation amount and the vehicle speed.

  In the vehicle control system, it is preferable that the vehicle control device controls the power source based on a target torque based on the required value and an actual gear ratio of the automatic transmission.

  In the vehicle control system according to the present invention, since the automatic transmission is controlled based on the target gear ratio based on the accelerator operation amount, frequent shifts are performed to cause the vehicle to generate acceleration corresponding to the required value. And the driver's discomfort can be suppressed.

FIG. 1 is a diagram illustrating a schematic configuration example of a vehicle control system according to the embodiment. FIG. 2 is a diagram showing the relationship between the required acceleration and the accelerator opening. FIG. 3 is a control flow diagram illustrating a vehicle control method by the vehicle control system according to the embodiment. FIG. 4 is a control flowchart showing a part of the vehicle control method by the vehicle control system according to the embodiment. FIG. 5 is a diagram showing the relationship between acceleration and vehicle speed at a constant accelerator opening. FIG. 6 is a diagram showing the relationship among acceleration, accelerator opening, and vehicle speed. FIG. 7 is a diagram illustrating a relationship among acceleration, accelerator opening, and vehicle speed. FIG. 8 is a diagram showing the relationship between the required acceleration and the vehicle speed when the accelerator opening is constant. FIG. 9 is a diagram showing the relationship between the required acceleration and the accelerator opening when the vehicle speed is constant. FIG. 10 is a diagram showing the relationship between the accelerator opening and time. FIG. 11 is a diagram showing the relationship between the required acceleration and time. FIG. 12 is a diagram illustrating the relationship between the throttle opening and time. FIG. 13 is a diagram illustrating a schematic configuration example of a vehicle control system that calculates a target gear ratio based on a required acceleration.

  Hereinafter, the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by the following embodiment. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same. The acceleration in the following embodiment includes not only the acceleration in the direction of accelerating the vehicle but also the acceleration in the direction of decelerating the vehicle.

  FIG. 1 is a diagram illustrating a schematic configuration example of a vehicle control system according to the embodiment. FIG. 2 is a diagram showing the relationship between the required acceleration and the accelerator opening when the vehicle speed is constant.

As shown in FIG. 1, at least a vehicle control system 1 is mounted on a vehicle on which the driver is boarded (hereinafter simply referred to as “vehicle CA”). The vehicle control system 1 includes an accelerator sensor 2, a vehicle speed sensor 3, an engine 4, a transmission (hereinafter simply referred to as “T / M”) 5, and an ECU 6. The vehicle control system 1 uses the accelerator operation amount output from the accelerator sensor 2 and the vehicle speed v output from the vehicle speed sensor 3 as input values to determine a required value in the ECU 6, and based on the determined required value, the engine 4 is controlled, T / M5 is controlled based on the accelerator operation amount and the vehicle speed v, and the vehicle G generates an acceleration G [m / s ² ] corresponding to the required value. That is, the vehicle control system 1 performs request value demand control. Here, the vehicle control system 1 determines the required value using the accelerator operation amount and the vehicle speed v as input values, and determines the required value using the positional relationship between the vehicle 1 and surrounding vehicles and obstacles as input values. There is nothing. Further, in the embodiment, the required value is the required acceleration Gx [m / s ² ], but is not limited to this, and any value corresponding to the acceleration G generated in the vehicle CA may be used. Fo [N] may be used. The vehicle control system 1 does not determine the requested vehicle speed using the accelerator operation amount and the vehicle speed v [km / h] as input values.

The accelerator sensor 2 detects the amount of accelerator operation according to the operation of the accelerator by the driver. In the embodiment, the accelerator sensor 2 detects an accelerator opening degree Pa [%] corresponding to an operation of an accelerator pedal (not shown) operated by the driver. The accelerator sensor 2 is connected to the ECU 6, a signal related to the accelerator opening Pa is output to the ECU 6, and the accelerator opening Pa is acquired by the ECU 6 as an input value. The acquired accelerator opening degree Pa is used when determining the required acceleration Gx [m / s ² ].

  The vehicle speed sensor 3 detects the vehicle speed v of the vehicle CA. The vehicle speed sensor 3 is connected to the ECU 6, a signal related to the vehicle speed v is output to the ECU 6, and the vehicle speed v is acquired by the ECU 6 as an input value. The acquired vehicle speed v is used when determining the required acceleration Gx. Here, the vehicle speed sensor 3 is not limited to a wheel speed sensor attached to each wheel of the vehicle CA, a sensor that detects the number of rotations of a rotating body in a route from the engine 4 to a driving wheel (not shown), and is represented by GPS. The sensor etc. which detect the position data of vehicle CA to be performed may be sufficient. In this case, the ECU 6 calculates the vehicle speed v based on the output position data.

  The engine 4 constitutes an acceleration generator that generates an acceleration G in the vehicle CA. The engine 4 is a power source, is a heat engine that converts the energy of the fuel into mechanical work by burning the fuel, and is a piston reciprocating engine. The engine 4 includes a fuel injection device (not shown), a throttle valve provided in an intake system (not shown) of the engine 4, a spark plug provided in a combustion chamber (not shown) of the engine 4, various sensors, and the like. Controlled by An output shaft (not shown) of the engine 4 is connected to an input shaft of the T / M 5, and mechanical power output from the engine 4 is transmitted to drive wheels (not shown) via the T / M 5, and acceleration G is transmitted to the vehicle CA. Will occur. The engine torque T generated by the engine 4 is controlled based on the target engine torque To determined based on the required acceleration Gx determined by the ECU 6. The engine 4 is provided with a crank angle sensor (not shown) that detects the rotational angle position of the output shaft (hereinafter referred to as “crank angle”), and a signal related to the crank angle is output to the ECU 6 to thereby detect the crank angle. Is acquired by the ECU 6 as an input value.

  T / M5 is a power transmission mechanism provided between the drive wheels of the vehicle and includes a lockup clutch 51, an automatic transmission 52, various sensors, and the like. These devices are controlled by the ECU 6. An output shaft (not shown) of T / M5 is connected to the drive wheels.

  The lock-up clutch 51 constitutes an acceleration generator that generates an acceleration G in the vehicle CA. The lock-up clutch 51 is a fluid coupling provided in the torque converter although illustration is omitted. The torque converter is provided between the engine 4 and the automatic transmission 52. The lockup clutch 51 transmits the engine torque T generated by the engine 4 directly to the automatic transmission 52 via the lockup clutch 51, that is, without passing through the fluid in the torque converter in the clutch engaged state. When the clutch is not engaged, the engine torque T is transmitted to the automatic transmission 52 via the fluid in the torque converter. In the clutch half-engaged state, the engine torque T is transmitted to the automatic transmission 52 via the fluid in the torque converter and the lock-up clutch 51. Here, the transmission efficiency differs between the fluid in the torque converter, which is a medium for transmitting the engine torque T, and the lockup clutch 51. Therefore, the lock-up clutch 51 transmits the mechanical power generated by the engine 4 to the drive wheels and converts the engine torque T according to the clutch state L. In the embodiment, the clutch state L of the lockup clutch 51 is controlled based on the target clutch state Lo determined based on the accelerator opening degree Pa and the vehicle speed v. The engine torque T transmitted to the lockup clutch 51 is converted according to the clutch state L and transmitted to the drive wheels, so that the acceleration G generated in the vehicle CA changes according to the clutch state L. Here, a signal related to the actual clutch state Ln, which is the actual clutch state of the lockup clutch 51, is output to the ECU 6, and the actual clutch state Ln is acquired by the ECU 6 as an input value.

  The automatic transmission 52 constitutes an acceleration generator that generates an acceleration G in the vehicle CA. The automatic transmission 52 is provided between the torque converter and the drive wheel. The automatic transmission 52 transmits the engine torque T to the drive wheels and converts the engine torque T. In the embodiment, the gear ratio γ of the automatic transmission 52 is controlled based on a target gear ratio γo determined based on the accelerator opening degree Pa and the vehicle speed v. The engine torque T transmitted to the automatic transmission 52 is converted according to the transmission gear ratio γ and transmitted to the drive wheels, so that the acceleration G generated in the vehicle CA changes according to the transmission gear ratio γ. Here, a signal related to the actual speed ratio γn, which is the actual speed ratio of the automatic transmission 52, is output to the ECU 6, and the actual speed ratio γn is acquired by the ECU 6 as an input value. The automatic transmission may be a stepped transmission or a continuously variable transmission. In the case of a stepped transmission, the target gear ratio γo is the target gear stage.

  The ECU 6 is a vehicle control device that controls the engine 4, which is an acceleration generation device, the lockup clutch 51, and the automatic transmission 52, based on the accelerator operation amount according to the accelerator operation by the driver and the vehicle speed v of the vehicle CA. is there. That is, the ECU 6 functions as an engine ECU and a transmission ECU. The ECU 6 outputs an injection signal, an ignition signal, an opening signal, etc. to the engine 4 based on the calculated target engine torque To, and the fuel supply amount and injection timing of the fuel supplied to the engine 4 by these output signals. Such as fuel injection control, ignition plug ignition control, throttle valve opening control, etc. not shown. Further, the ECU 6 outputs various hydraulic control signals and the like to the T / M 5 based on the calculated target clutch state Lo and the target speed ratio γo, and the clutch control of the lockup clutch 51 and the automatic transmission are output based on these output signals. 52 shift control or the like is performed. The hardware configuration of the ECU 6 mainly includes a CPU (Central Processing Unit) that performs arithmetic processing, a memory that stores programs and information (RAM such as SRAM, ROM (Read Only Memory) such as EEPROM), and an input / output interface. Since the configuration is the same as that of an ECU mounted on a known vehicle, detailed description thereof is omitted.

  In the embodiment, the ECU 6 determines the target clutch state Lo and the target speed ratio γo based on the accelerator opening degree Pa and the vehicle speed v of the vehicle CA, and based on the determined target clutch state Lo and the target speed ratio γo. The lockup clutch 51 and the automatic transmission 52 (hereinafter simply referred to as “torque converter”) are controlled. In the embodiment, the ECU 6 determines the required acceleration Gx, which is a static required acceleration, based on the accelerator opening degree Pa and the vehicle speed v of the vehicle CA, and the dynamic required acceleration based on the determined required acceleration Gx. Gy is determined, a target engine torque To is determined based on the determined dynamic required acceleration Gy, and the engine 4 is controlled based on the determined target engine torque To. The ECU 6 includes a target gear ratio calculation unit 61, a required acceleration calculation unit 62, and a target engine torque calculation unit 63.

  The target gear ratio calculation unit 61 determines a target value for controlling the acceleration generator. The target gear ratio calculation unit 61 calculates the target clutch state Lo and the target gear ratio γo based on the accelerator opening degree Pa and the vehicle speed v of the vehicle CA. The target gear ratio calculation unit 61 determines the target clutch state Lo and the target gear ratio γo based on, for example, the accelerator opening degree Pa, the vehicle speed v, and a speed change map based on the accelerator opening degree Pa and the vehicle speed v. If the automatic transmission 52 is a stepped transmission, the shift map includes an upshift line corresponding to the accelerator opening degree Pa and the vehicle speed v (if the vehicle speed v exceeds the upshift line in the increasing direction, it is one step higher than the current shift stage. The target gear ratio γo (target gear ratio) is used as the high-speed gear position, and the downshift line (if the vehicle speed v crosses the downshift line in the decreasing direction, the target gear ratio is set to a gear position that is one speed lower than the current gear stage. γo (target shift speed), lock-up line (the target clutch state Lo is set to a value at which the clutch state is engaged when the vehicle speed v exceeds the lock-up line in the increasing direction), lock-up release line (vehicle speed) When v exceeds the lock-up release line in the decreasing direction, the target clutch state Lo is set to a value at which the clutch state is disengaged). Here, since the method of determining the target clutch state Lo and the target gear ratio γo based on the accelerator opening degree Pa and the vehicle speed v of the vehicle CA is known, detailed description thereof is omitted. The EUC 6 controls the lockup clutch 51 and the automatic transmission ratio 52 so that the clutch state Lo and the transmission gear ratio γ become the target clutch state Lo and the target transmission gear ratio γo.

  The required acceleration calculation unit 62 determines the required acceleration Gx based on the accelerator opening degree Pa and the vehicle speed v of the vehicle CA, and determines the dynamic required acceleration Gy based on the determined required acceleration Gx. The required acceleration calculation unit 62 uses the acceleration when the accelerator operation amount is constant determined by the relationship between the vehicle speed v and the acceleration G when the accelerator operation amount is constant (hereinafter, simply referred to as “v-G relationship”). The required acceleration Gx, which is a required value, is determined based on the relationship between the accelerator operation amount and the required value. The required acceleration calculation unit 62 is based on the accelerator opening degree Pa and the vehicle speed v, and the accelerator opening degree Pa and the required acceleration Gx on the condition of the acceleration constant acceleration Gx1 determined by the v-G relationship at the constant accelerator opening degree Pa1. (Hereinafter simply referred to as “Pa-Gx relationship”), the required acceleration Gx, which is a static required acceleration, is calculated and output to the target engine torque calculation unit 63. The required acceleration calculation unit 62 is based on the accelerator opening degree Pa, the vehicle speed v, and an exponential function based on Weber-Fechner's law (hereinafter simply referred to as “WF exponential function”). Gx is calculated. The WF index function is defined such that when the accelerator opening degree Pa is a constant accelerator opening degree Pa1 at an arbitrary vehicle speed v, the acceleration constant acceleration Gx1 at the arbitrary vehicle speed v is calculated as the required acceleration Gx. Therefore, the required acceleration calculation unit 62 calculates the same accelerator constant time acceleration Gx1 as the required acceleration Gx when the vehicle speed v is the same and the accelerator opening degree Pa1 is constant. That is, the Pa-Gx relationship according to the embodiment has a predetermined characteristic that the required acceleration Gx is calculated based on the WF index function. Further, the Pa-Gx relationship according to the embodiment has a predetermined characteristic in which the acceleration constant acceleration Gx1 determined by the v-G relationship at the constant accelerator opening Pa1 is calculated as the required acceleration Gx at the constant accelerator opening Pa1. . The constant accelerator opening degree Pa1 is 60% in the embodiment, but is not limited to this, and is set as appropriate according to various conditions such as the vehicle type, the configuration of the mounted acceleration generator, and the specifications of the vehicle CA. Is. The constant accelerator opening degree Pa1 is preferably a large accelerator opening degree Pa that does not approach the maximum accelerator opening degree Pamax. This is because the slope of the relationship line X2 described later increases as the constant accelerator opening degree Pa1 approaches the maximum accelerator opening degree Pamax.

  Here, the Pa-Gx relationship is based on the condition that the acceleration is constant acceleration Gx1 and the minimum acceleration Gx0 that is the acceleration G when the idle is switched from on to off. Here, “idle on” means that the accelerator opening degree Pa is 0%, that is, the state of the fully closed accelerator opening degree Pa0 (accelerator is off), and “idle off” means a state other than the fully closed accelerator opening degree Pa0 (accelerator). Is on). The WF exponent function is defined such that the minimum acceleration Gx0 is calculated as the required acceleration Gx when the idling is on, that is, when the fully closed accelerator opening degree Pa0. In the embodiment, when the idling is switched from on to off, the value is determined according to the minimum generated acceleration Gxmin that is the acceleration G that can be generated by the engine 4 and the T / M 5 that are the acceleration generating devices, or the vehicle speed v, that is, the setting One of the minimum accelerations Gx0 ′ is determined as the minimum acceleration Gx0. The minimum generated acceleration Gxmin is the current vehicle speed v, the gear ratio γ, and the lockup engagement state when the lockup is provided, the fuel flow learning value, the feedback correction amount for the fuel flow rate, and the correction amount at the start for the fuel flow rate. , Fuel cut state, engine water temperature, air compressor load, alternator load (electric load), catalyst warm-up correction amount provided in exhaust system for fuel flow rate, engine stop avoidance correction amount for fuel flow rate, correction amount for purge for fuel flow rate, It is calculated based on factors such as a deceleration transient correction amount with respect to the fuel flow rate. The set minimum acceleration Gx0 ′ is set in advance in relation to the vehicle speed v. For example, as shown in FIG. 5, the set minimum acceleration Gx0 ′ is set to decrease as the vehicle speed v increases.

  In the embodiment, the requested acceleration calculation unit 62 determines the set minimum acceleration Gx0 ′ as the minimum acceleration Gx0 when the idling is on, and sets the minimum setting when the idling is switched from on to off when the idling is switched from on to off. When the acceleration Gx0 ′ is different from the calculated minimum generated acceleration Gxmin, the minimum generated acceleration Gxmin is determined as the minimum acceleration Gx0, and when the idle is off, the minimum acceleration Gx0 is maintained at the minimum generated acceleration Gxmin regardless of the vehicle speed v. . That is, when idle is on, that is, when the accelerator opening degree Pa is other than the fully closed accelerator opening degree Pa0, the minimum generated acceleration Gxmin is set to the minimum acceleration Gx0.

  Further, when the accelerator opening degree Pa is at least a region larger than the constant accelerator opening degree Pa1, in the embodiment, the boundary accelerator opening degree Pa2 (>) where the accelerator opening degree Pa is larger than the constant accelerator opening degree Pa1. If it exceeds Pa1), the maximum generated acceleration Gxmax, which is the acceleration G that can be generated by the engine 4 and T / M5 when the accelerator opening Pa is 100% of the maximum (accelerator operation amount maximum), that is, at the maximum accelerator opening Pamax, Condition. The requested acceleration calculation unit 62 calculates the boundary required acceleration calculated based on the arbitrary vehicle speed v, the boundary accelerator opening Pa2, and the WF index function when the accelerator opening Pa exceeds the boundary accelerator opening Pa2 at an arbitrary vehicle speed v. The required acceleration Gx is calculated by complementing Gx2 based on the maximum generated acceleration Gxmax at an arbitrary vehicle speed v. Specifically, the required acceleration calculation unit 62 calculates the required acceleration Gx by performing linear interpolation based on the boundary required acceleration Gx2 and the maximum generated acceleration Gxmax. Here, when the accelerator opening degree Pa is the maximum accelerator opening degree Pamax at an arbitrary vehicle speed v, the required acceleration calculation unit 62 calculates the maximum generated acceleration Gxmax at the arbitrary vehicle speed v as the required acceleration Gx. That is, the Pa-Gx relationship is determined such that the required acceleration Gx becomes the maximum generated acceleration Gxmax when the maximum accelerator opening degree Pamax is reached. Therefore, as shown in FIG. 2, the Pa-Gx relationship is a relationship line X1 (a relationship line based on the WF index function) between the accelerator opening degree Pa including the acceleration constant acceleration Gx1 and the required acceleration Gx, regardless of the vehicle speed v. And a relationship line X2 between the accelerator opening degree Pa including the maximum generated acceleration Gxmax and the required acceleration Gx (a relationship line for linearly interpolating between the boundary required acceleration Gx2 and the maximum generated acceleration Gxmax). The required acceleration Gx is calculated based on a WF exponent function with the accelerator opening degree Pa being 0, that is, when the idling is on and the acceleration is constant when the acceleration is constant Gx1 and the minimum acceleration Gx. When the region is larger than the degree Pa1, the maximum generated acceleration Gxmax is supplemented in consideration of the maximum output characteristic of the acceleration generator. That is, the Pa-Gx relationship according to the embodiment has a predetermined characteristic that the required acceleration Gx is complemented by the maximum generated acceleration Gxmax when the accelerator opening degree Pa is at least a region larger than the constant accelerator opening degree Pa1. Further, the Pa-Gx relationship according to the embodiment has a predetermined characteristic that the maximum generated acceleration Gxmax becomes the required acceleration Gx at the maximum accelerator pedal opening Pamax. The boundary accelerator opening degree Pa2 is set to 80% in the embodiment, but is not limited to this. The boundary accelerator opening degree Pa2 is appropriately set according to various conditions such as the vehicle type, the configuration of the mounted acceleration generator, and the specifications of the vehicle CA. The Further, the complementing method is not limited to linear interpolation, and other polynomial interpolation may be used.

Further, the required acceleration calculation unit 62 calculates the dynamic required acceleration Gy [m / s ² ] based on the calculated required acceleration Gx, and outputs it to the target engine torque calculation unit 63. The required acceleration calculation unit 62 determines a change (curve) until the acceleration G generated in the vehicle CA reaches the required acceleration Gx using the dynamic filter. Therefore, the required acceleration calculation unit 62 can change the response of the throttle opening Sa that affects the acceleration G with respect to the accelerator opening Pa. For example, when the vehicle CA starts, the dynamic required acceleration Gy is calculated by increasing the degree of smoothing using a dynamic filter so that the response of the acceleration G becomes low, thereby enabling a smooth start. Further, when the driver's accelerator operation speed is high, the dynamic required acceleration Gy is calculated by reducing the degree of smoothing with a dynamic filter so that the response of the acceleration G becomes high, and the throttle of the engine 4 is throttled. The valve is temporarily opened excessively, and a highly responsive acceleration G is generated in the vehicle CA. That is, in the ECU 6, the required acceleration calculation unit 62 calculates the required acceleration Gx that is a static required acceleration and the dynamic required acceleration Gy separately, so that the accelerator opening degree Pa determined by the required acceleration calculation unit 62 can be reduced. The nonlinearity of the throttle opening Sa, that is, the nonlinearity of the acceleration G with respect to the accelerator opening Pa, and the responsiveness of the throttle opening Sa to the accelerator opening determined by the required acceleration calculator 62, that is, the response of the acceleration G to the accelerator opening Pa. Sex can be separated.

  The target engine torque calculation unit 63 determines a target value for controlling the acceleration generator. In the embodiment, the target engine torque calculating unit 63 determines the required driving force Fo based on the dynamic required acceleration Gy calculated by the required acceleration calculating unit 62, and sets the target driving force Fo based on the determined required driving force Fo. An engine torque To is calculated. The target engine torque calculator 63 calculates the required driving force Fo based on the dynamic required acceleration Gy calculated by the required acceleration calculator 62. The target engine torque calculation unit 63 is calculated based on the specifications of the vehicle CA and the running resistance. For example, the target engine torque calculation unit 63 calculates a driving force obtained by adding a driving force based on the dynamic required acceleration Gy and the mass of the vehicle CA and a driving force based on the running resistance as the required driving force Fo.

  The target engine torque calculation unit 63 calculates the target engine torque To based on the calculated required driving force Fo, the actual clutch state Ln of the lockup clutch 51, and the actual gear ratio γn of the automatic transmission 52. The target engine torque calculation unit 63 calculates the target engine torque To so that the required driving force Fo can be generated in the clutch state L of the lockup clutch 51 and the gear ratio γ of the automatic transmission 52. That is, the target engine torque calculation unit 63 calculates the target engine torque To so that the required acceleration Gx can be generated based on the clutch state L of the lockup clutch 51 and the gear ratio γ of the automatic transmission 52. The EUC 6 controls the engine 4 so that the engine torque T generated by the engine 4 becomes the target engine torque To.

  Next, a vehicle control method by the vehicle control system 1 will be described. Here, a method for determining the required acceleration Gx based on the accelerator opening degree Pa and the vehicle speed v will be described. Since the method for controlling the engine 4, the lockup clutch 51, and the automatic transmission 52 based on the determined required acceleration Gx has been described above, it is omitted here. FIG. 3 is a control flow diagram illustrating a vehicle control method by the vehicle control system according to the embodiment. FIG. 4 is a control flowchart showing a part of the vehicle control method by the vehicle control system according to the embodiment. FIG. 5 is a diagram showing the relationship between acceleration and vehicle speed at a constant accelerator opening. FIG. 6 is a diagram showing the relationship among acceleration, accelerator opening, and vehicle speed. FIG. 7 is a diagram illustrating a relationship among acceleration, accelerator opening, and vehicle speed. FIG. 8 is a diagram showing the relationship between the required acceleration and the vehicle speed when the accelerator opening is constant. FIG. 9 is a diagram showing the relationship between the required acceleration and the accelerator opening when the vehicle speed is constant. FIG. 10 is a diagram showing the relationship between the accelerator opening and time. FIG. 11 is a diagram showing the relationship between the required acceleration and time. FIG. 12 is a diagram illustrating the relationship between the throttle opening and time.

  First, as shown in FIG. 3, the ECU 6 of the vehicle control system 1 acquires the accelerator opening degree Pa and the vehicle speed v of the vehicle CA as described above (step ST1).

  Next, the ECU 6 calculates a minimum acceleration Gx0 (step ST2). First, as shown in FIG. 4, the ECU 6 determines whether or not idling is on (step ST21). Here, the ECU 6 determines whether or not the accelerator opening degree Pa is the fully closed accelerator opening degree Pa0.

  Next, when the ECU 6 determines that the idle is on (Yes at step ST21), the ECU 6 determines whether or not the idle is switched from on to off (step ST22). Here, the ECU 6 determines whether or not the minimum acceleration Gx0 is determined as the minimum generated acceleration Gxmin by determining whether or not the accelerator opening Pa is other than the fully closed accelerator opening Pa0 from the fully closed accelerator opening Pa0. It is determined whether to determine the minimum acceleration Gx0 ′.

  Next, when the ECU 6 determines that the idling has switched from on to off (Yes in step ST22), the ECU 6 calculates the minimum generated acceleration Gxmin and determines the minimum acceleration Gx0 as the calculated minimum generated acceleration Gxmin (Gx0 = Gxmin). (Step ST23).

  Next, the ECU 6 resets the dynamic filter (step ST24). Here, since the ECU 6 resets the dynamic filter when the idling is switched from on to off and the driver starts the operation, the requested acceleration Gx calculated based on the minimum generated acceleration Gxmin that is the minimum acceleration Gx0. Based on the above, the required acceleration calculation unit 62 can calculate the dynamic required acceleration Gy using a new dynamic filter. Thereby, when changing the required acceleration Gx based on the change of the minimum acceleration Gx0, it is possible to suppress the influence of the required driving force Fo before correction by not resetting the dynamic filter.

  Next, the ECU 6 determines the determined minimum acceleration Gx0 as the previous minimum acceleration Gx0last (Gx0 = Gx0last) (step ST25).

  If the ECU 6 determines that the idling has not been switched from on to off (No in step ST22), the ECU 6 sets the set minimum acceleration Gx0 'based on the vehicle speed v, and sets the minimum acceleration Gx0 to the set minimum acceleration Gx0'. (Gx0 = Gx0 ′) is determined (step ST26).

  When ECU 6 determines that the idling is off (No in step ST21), ECU 6 determines the determined previous minimum acceleration Gx0last as minimum acceleration Gx0 (Gx0last = Gx0) (step ST27). Here, the ECU 6 switches the minimum acceleration Gx0 from on to off until the accelerator opening degree Pa changes from the fully closed accelerator opening degree Pa0 to a position other than the fully closed accelerator opening degree Pa0 and again becomes the fully closed accelerator opening degree Pa0. It is set as the minimum generated acceleration Gxmin calculated at the time.

Next, as shown in FIG. 3, the ECU 6 calculates an acceleration constant acceleration Gx1 (step ST3). Here, the ECU 6 calculates the accelerator constant acceleration Gx1 based on the acquired accelerator opening degree Pa, vehicle speed v, and the following equation (1). Here, A is greater than 0 and determines the required acceleration Gx when the vehicle speed v is 0. B is smaller than 0 and defines the degree of deceleration of the required acceleration Gx accompanying the increase in the vehicle speed v. A and B are appropriately set according to various conditions such as the vehicle type, the configuration of the mounted acceleration generator, and the specifications of the vehicle CA. For example, A = 5, B = −0.02, = 6, B = -0.015. That is, the vG relationship when the accelerator opening degree Pa is constant is determined from the following equation (1).
Gx1 = A × e ^{B · v} (1)

Next, the ECU 6 calculates C (v) (step ST4). Here, the ECU 6 calculates C (v) from the calculated minimum acceleration Gx0, the calculated accelerator constant acceleration Gx1, the constant accelerator opening degree Pa1, the Weber ratio k, and the following equation (2). To do. Here, the Weber ratio k is appropriately set in consideration of, for example, controllability when the vehicle CA starts or reaccelerates. For example, k = 1.2.
C (v) = (Gx1-Gx0) / Pa1 ^k (2)

  Next, the ECU 6 determines whether or not the accelerator opening degree Pa exceeds the boundary accelerator opening degree Pa2 (step ST5). Here, the ECU 6 determines whether or not the accelerator opening degree Pa exceeds the boundary accelerator opening degree Pa2, thereby calculating the required acceleration Gx by a WF exponential function or by complementing based on the maximum generated acceleration Gxmax. Determine whether. That is, the ECU 6 determines the required acceleration Gx based on the relationship line X1 between the accelerator opening degree Pa including the acceleration constant acceleration Gx1 and the required acceleration Gx, or the accelerator opening degree Pa including the maximum generated acceleration Gxmax and the required acceleration Gx. It is determined whether to determine based on the relationship line X2.

Next, when the ECU 6 determines that the accelerator opening degree Pa is equal to or less than the boundary accelerator opening degree Pa2 (No in step ST5), the ECU 6 calculates a required acceleration Gx (step ST6). Here, the ECU 6 calculates the required acceleration Gx based on the WF index function. The ECU 6 calculates the required acceleration Gx from the accelerator opening degree Pa, the calculated C (v), the calculated minimum acceleration Gx0, and the following equation (3).
Gx = C (v) Pa ^k + Gx0 (3)

When ECU 6 determines that accelerator opening Pa exceeds boundary accelerator opening Pa2 (Yes in step ST5), ECU 6 calculates boundary required acceleration Gx2 (step ST7). Here, the ECU 6 calculates the boundary required acceleration Gx2 based on the boundary accelerator opening degree Pa2, the calculated C (v), the calculated minimum acceleration Gx0, and the following equation (4).
^{Gx2 = C (v) Pa2 k} + Gx0 ... (4)

Next, the ECU 6 calculates the required acceleration Gx (step ST8). Here, the ECU 6 calculates the required acceleration Gx based on the maximum generated acceleration Gxmax. The ECU 6 calculates the required acceleration Gx according to the accelerator opening Pa, the maximum accelerator opening Pamax, the boundary accelerator opening Pa2, the maximum generated acceleration Gxmax, the calculated boundary required acceleration Gx2, and the following equation (5). calculate.
Gx = (Gxmax−Gx2) / (Pamax−Pa2) Pa + Gx2 (5)

  As described above, in the vehicle control system 1 according to the embodiment, when determining the required acceleration Gx, the vG relationship at the constant accelerator opening degree Pa1 affects. In the embodiment, the vG relationship at the constant accelerator opening degree Pa1 can be designed as shown by a solid line in FIG. The alternate long and short dash line in the figure is a v-G relationship at a constant accelerator opening Pa1 when Weber-Fechner's law is applied to the entire accelerator opening Pa (hereinafter referred to as the "entire WF region"). The WF index function is the maximum occurrence at any vehicle speed v when the minimum acceleration Gx0 at any vehicle speed v is the maximum accelerator opening Pamax when the accelerator opening Pa is the fully closed accelerator opening Pa0 at any vehicle speed v. It is determined that the acceleration Gxmax is calculated as the required acceleration Gx. As shown in the figure, the v-G relationship at the constant accelerator pedal opening degree Pa1 in the embodiment shows that the acceleration G generated in the vehicle CA with the increase in the vehicle speed v is generally slower than in the entire WF region. Designed to reduce to. That is, the v-G relationship at the constant accelerator opening degree Pa1 in the embodiment is designed so that the gradient between the vehicle speed v and the acceleration G is nearly uniform. Therefore, the vG relationship at the constant accelerator opening degree Pa1 is determined under the influence of the maximum generated acceleration Gxmax in the case of the entire WF region, but in the embodiment, it is difficult to be influenced by the maximum generated acceleration Gxmax. As a result, in the Pa-Gx relationship where the v-G relationship at the constant accelerator opening degree Pa1 is a condition, the acceleration G generated in the vehicle CA in the vehicle speed direction when the constant accelerator opening degree Pa1 is maintained can be designed.

  For example, in the relationship between the accelerator opening degree Pa and the acceleration G (hereinafter simply referred to as “Pa-G relation”) in the case of the entire WF region, at the constant accelerator opening degree Pa1, a solid line of 0 [km / h] and the acceleration change ΔG1 between the acceleration G at 50 [km / h] shown in the figure and the acceleration G at 50 [km / h] and the two-dot chain line shown in FIG. / H], the acceleration change ΔG2 is significantly larger than the acceleration change ΔG2. Therefore, even if the accelerator opening degree Pa1 is constant, the acceleration G greatly changes depending on the vehicle speed v. Thus, in the Pa-G relationship in the case of the entire WF region, it is difficult to design the acceleration G in the vehicle speed direction at the constant accelerator opening degree Pa1. However, in the Pa-Gx relationship (Pa-G relationship) with the vG relationship at the constant accelerator opening degree Pa1, the acceleration G at 0 [km / h] of the solid line shown in FIG. The acceleration change ΔG3 with the acceleration G at 50 [km / h] shown by the dashed line and the acceleration G at 50 [km / h] and the acceleration G at 100 [km / h] shown by the two-dot chain line shown in FIG. The difference between G and acceleration change ΔG4 is smaller than the difference between acceleration change ΔG1 and acceleration change ΔG2. Therefore, even if the accelerator opening degree Pa1 is constant, it is possible to suppress the acceleration G from greatly changing depending on the vehicle speed v. As described above, in the Pa-Gx relationship where the vG relationship at the constant accelerator opening degree Pa1 is a condition, the acceleration G in the vehicle speed direction at the constant accelerator opening degree Pa1 can be designed. From the above, by determining the optimum required acceleration Gx with respect to the accelerator opening degree Pa of the driver, it is possible to sufficiently realize acceleration in accordance with the driver's sensitivity. Moreover, if the accelerator opening degree Pa is the same, it is possible to give an acceleration feeling that approximates the driver regardless of the vehicle speed v.

  Further, in the Pa-Gx relationship that only requires the minimum acceleration Gx0 and the v-G relationship at the constant accelerator opening degree Pa1, even if the accelerator opening degree Pa becomes the maximum accelerator opening degree Pamax, the required acceleration Gx is generated at the maximum. It becomes smaller than the acceleration Gxmax. Therefore, as the accelerator opening degree Pa approaches the maximum accelerator opening degree Pamax, there is a possibility that the difference between the acceleration G and the acceleration G that can be generated by the engine 4 and the T / M 5 as the acceleration generating device may be widened. Therefore, the Pa-Gx relationship in the vehicle control system 1 according to the embodiment indicates that when the accelerator opening degree Pa exceeds the boundary accelerator opening degree Pa2 larger than the constant accelerator opening degree Pa1, the v at the minimum acceleration Gx0 and the constant accelerator opening degree Pa1. The condition is the -G relationship and the maximum generated acceleration Gxmax. The Pa-Gx relationship according to the embodiment is the first Pa-Gx relationship (the above formula (3)), which is a Pa-Gx relationship based on Weber-Fechner's law, and the maximum required acceleration Gx is generated at the maximum accelerator opening Pamax. A second Pa-Gx relationship (the above formula (5)) that is a Pa-Gx relationship that complements based on the maximum generated acceleration Gxmax so as to be the acceleration Gxmax. As shown in FIG. 8, when the accelerator opening degree Pa is equal to or less than the boundary accelerator opening degree Pa2, the first Pa-Gx relationship is applied (WF region). Further, when the accelerator opening degree Pa exceeds the boundary accelerator opening degree Pa2, the second Pa-Gx relationship is applied (complementary region). Therefore, the difference between the acceleration G generated in the vehicle CA at the same accelerator opening degree Pa and the acceleration G that can be generated by the engine 4 and T / M 5 as the acceleration generating device in a region where the accelerator opening degree Pa is large is large. This can be suppressed. Thus, by considering the maximum generated acceleration Gxmax, it is possible to sufficiently realize acceleration in accordance with the driver's sensitivity.

  In the second Pa-Gx relationship, since the required acceleration Gx becomes the maximum generated acceleration Gxmax at the maximum accelerator opening Pamax, the maximum generated acceleration Gxmax is generated in the vehicle CA at the maximum accelerator opening Pamax. Therefore, the maximum output of the engine 4 can be guaranteed, and acceleration in accordance with the driver's sensitivity can be sufficiently realized.

  Therefore, the Pa-Gx relationship in the vehicle control system 1 according to the embodiment is such that the minimum acceleration Gx0 when the idling is switched from on to off is the minimum set acceleration Gx0 ′ when the idling is switched from on to off. When it is different from the generated acceleration Gxmin, the minimum generated acceleration Gxmin is determined as the minimum acceleration Gx0. Accordingly, as shown by the one-dot chain line shown in FIG. 9, when the minimum acceleration Gx0 when the idle is switched from on to off is set to the set minimum acceleration Gx0 ′ larger than the minimum generated acceleration Gxmin (Gxmin <Gx0), As shown by the two-dot chain line shown in the figure, even when the minimum acceleration Gx0 when the idle is switched from on to off is set to the minimum set acceleration Gx0 ′ smaller than the minimum generated acceleration Gxmin (Gxmin> Gx0), the same figure is shown. As indicated by the solid line, the minimum acceleration Gx0 when the idle is switched from on to off is determined as the minimum generated acceleration Gxmin (Gxmin = Gx0). As a result, the minimum acceleration Gx0 is minimally generated when the accelerator opening degree Pa changes from the fully closed accelerator opening degree Pa0 to a position other than the fully closed accelerator opening degree Pa0, that is, when the idling is switched from on to off (see FIG. 10). The acceleration becomes Gxmin (see FIG. 11). As indicated by the alternate long and short dash line in FIG. 12, when Gxmin <Gx0, the required acceleration Gx is changed from Gxmin to Gx0. Therefore, the throttle opening Sa relative to the accelerator opening Pa increases significantly from when the accelerator is turned on. As a result, a step is generated in the driving force generated in the vehicle CA. Further, as shown by a two-dot chain line shown in FIG. 12, when Gxmin> Gx0, the acceleration G generated in the vehicle CA does not change until the required acceleration Gx changes from Gx0 to Gxmin. Since the degree Sa does not change for a while after the accelerator is turned on, a dead zone in which no driving force is generated occurs in the vehicle CA. However, as indicated by the solid line in FIG. 12, when Gxmin = Gx0, the required acceleration Gx immediately after the accelerator is turned on is Gxmin, and therefore, the throttle opening Sa relative to the accelerator opening Pa immediately after the accelerator is turned on is Gxmin < Between Gx0 and Gxmin> Gx0, the driving force can be generated in the vehicle CA immediately after the accelerator is turned on. Therefore, it is possible to compensate for the connection of the driving force from when the accelerator is off to when it is on, and the acceleration G generated in the vehicle CA changes continuously, so that the vehicle CA can be smoothly started and re-accelerated. Further, when the idling is switched from on to off, the minimum acceleration Gx0 is set as the minimum generated acceleration Gxmin. Therefore, during the accelerator operation by the driver, for example, the required acceleration Gx is changed to the minimum acceleration Gx0 while the accelerator opening degree Pa is constant. The change of the acceleration G due to the change based on the can be suppressed.

  The Pa-Gx relationship in the vehicle control system 1 according to the embodiment is a predetermined characteristic based on the generated acceleration that can be generated by the engine 4 and the T / M 5 that are acceleration generating devices, and in the embodiment, the minimum generated acceleration Gxmin. It will be changed while maintaining. Therefore, it is possible to smoothly start and re-accelerate the vehicle CA while sufficiently realizing acceleration in accordance with the driver's sensitivity, and to suppress the difference between the required acceleration Gx and the generated acceleration. Deterioration of drivability can be suppressed.

  Normally, in demand control based on the requested acceleration Gx (requested value), the engine 4 and the torque converter (the lockup clutch 51 and the automatic transmission 52) are controlled based on the requested acceleration Gx (requested value). As shown in FIG. 13, in the control based on the required acceleration Gx, the target speed ratio calculating unit 64 that calculates the target speed ratio γo uses the dynamic required acceleration Gy based on the required acceleration Gx and the target vehicle speed v as a target. The clutch state Lo and the target gear ratio γo are calculated. For example, the target transmission ratio calculation unit 64 calculates the required driving force Fo from the dynamic required acceleration Gy as described above, and is based on the calculated required driving force Fo, the vehicle speed v, the required driving force Fo, and the vehicle speed v. A target clutch state Lo and a target gear ratio γo are determined based on the shift map. Therefore, when the engine 4 and the torque converter are controlled based on the required acceleration Gx (requested value), the required acceleration Gx can be easily generated in the vehicle CA. That is, when the engine 4 and the torque converter are controlled based on the required acceleration Gx (requested value), the engine 4 and the torque converter can be controlled in the same row to easily meet the driver's request for acceleration.

  On the other hand, in the vehicle control system 1 according to the embodiment, the lock-up clutch 51 and the automatic transmission 52 are controlled based on the target clutch state Lo and the target gear ratio γo based on the accelerator opening degree Pa and the vehicle speed v, respectively. . That is, when the engine 4 is controlled based on the required acceleration Gx (required value) and the torque converter is controlled by the accelerator opening, the engine 4 and the torque converter are controlled separately. Therefore, since the engine 4 is controlled based on the required acceleration Gx (requested value), the driver's request for acceleration can be met. Therefore, by controlling the torque converter based on the accelerator opening degree Pa and the vehicle speed v. A purpose different from generating the required acceleration Gx can be achieved. For example, the target gear ratio calculation unit 61 can calculate the target gear ratio γo (target gear stage) having many operation regions where the fuel consumption of the engine 4 is low from the accelerator opening degree Pa and the vehicle speed v. Therefore, in the vehicle control system 1 according to the embodiment, it is possible to easily ensure fuel consumption performance. Further, as a result of controlling the engine 4 and the torque converter based on the requested acceleration Gx (requested value), there is a risk that frequent shifting such as shifting of the automatic transmission 52 may be performed even if the accelerator opening degree Pa is constant. In the vehicle control system 1 according to the embodiment, since the automatic transmission 52 is shift-controlled based on at least the accelerator opening Pa, frequent shifts can be suppressed, and the driver's uncomfortable feeling can be suppressed.

  In the above embodiment, the maximum generated acceleration Gxmax is used as a condition in the Pa-Gx relationship, but the present invention is not limited to this, and the maximum generated acceleration Gxmax may not be used as a condition. That is, the required acceleration Gx may be calculated based on the WF exponent function over the entire accelerator opening Pa. In this case, it is preferable to design the v-G relationship when the accelerator operation amount is constant, which is a condition in the Pa-Gx relationship, so that the required acceleration Gx approaches the maximum generated acceleration Gxmax at the maximum accelerator opening Pamax.

  In calculating the required driving force Fo, the running resistance is considered, but the running resistance may not be taken into consideration. In the above embodiment, the acceleration generator is the engine 4, the lockup clutch 51, and the automatic transmission 52. However, the present invention is not limited to this, and a motor as a power source and a motor torque that is an output of the motor are converted. You may be comprised by the power transmission mechanism which can do.

  As described above, the vehicle control system determines the required value corresponding to the acceleration acting on the vehicle based on the accelerator operation amount corresponding to the accelerator operation by the driver and the vehicle speed of the vehicle, and the vehicle control. It is useful for the method and is particularly suitable for suppressing the driver's uncomfortable feeling.

DESCRIPTION OF SYMBOLS 1 Vehicle control system 2 Accelerator sensor 3 Vehicle speed sensor 4 Engine 5 Transmission (T / M)
51 Lock-up clutch 52 Automatic transmission 6 ECU
61 Target gear ratio calculation unit 62 Required acceleration calculation unit 63 Target engine torque calculation unit 64 Target gear ratio calculation unit

Claims (3)

An acceleration generator for generating acceleration in the vehicle;
A vehicle control device that controls the acceleration generating device based on an accelerator operation amount according to an accelerator operation by a driver and a vehicle speed of the vehicle;
A vehicle control system comprising:
The acceleration generator includes a power source, and an automatic transmission provided between the power source and the drive wheels of the vehicle,
The vehicle control device controls the power source based on a request value corresponding to the acceleration based on the accelerator operation amount and the vehicle speed, and also performs the automatic operation based on a target speed ratio based on the accelerator operation amount. A vehicle control system for controlling a transmission.   The vehicle control system according to claim 1, wherein the target gear ratio is based on the accelerator operation amount and the vehicle speed.   The vehicle control system according to claim 1, wherein the vehicle control device controls the power source based on a target torque based on the required value and an actual gear ratio of the automatic transmission. .

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