JP2019167047A - Drive force control device of vehicle - Google Patents

Abstract

To provide a drive force control device of a vehicle which is constituted so as to be capable of setting a drive force characteristic corresponding to a driving way of a driver.SOLUTION: In a drive force control device of a vehicle having a drive force map for defining a target drive force large as an operation amount of an accelerator device which is operated by a driver is large, and defining the target drive force small as a vehicle speed is high, a lowering amount of an operation amount during the acceleration of the vehicle is integrated (step S4), and the drive force map is updated so that the target drive force with respect to the vehicle speed in the drive force map becomes small as the integrated lowering amount is large (step S6).SELECTED DRAWING: Figure 4

Description

  The present invention relates to a vehicle driving force control device that determines a target driving force in accordance with an accelerator opening.

  In Patent Document 1, based on the time during which the accelerator is operated and the accelerator opening, the driving orientation is a driving orientation for performing sporty driving in which the behavior of the vehicle is agile, or the behavior of the vehicle becomes slow. There is described a vehicle control device configured to determine whether it is driving-oriented to perform mild driving or driving-oriented to perform normal driving that is the behavior of an intermediate vehicle. The vehicle control device is configured to calculate a driving force characteristic that sets a throttle opening and a control amount of a gear ratio with respect to an accelerator operation amount based on the driving orientation. Specifically, if it is driving-oriented with mild driving, the control gain is set to a small value, or the value of the correction coefficient is set so as to reduce the control amount, and sporty driving is performed. If it is driving-oriented, the control gain is set to a large value, or the correction coefficient value is set to increase the control amount.

Japanese Patent No. 5234224

  The control device described in Patent Document 1 is configured to determine the driver's driving orientation in accordance with the accelerator operation and to calculate the driving force characteristics in accordance with the driving orientation. It can be reflected in the driving force characteristics quickly and accurately. On the other hand, in general vehicle driving force characteristics, the target driving force is set larger as the accelerator opening is larger, and the target driving force is set smaller as the vehicle speed is higher. In some cases, the accelerator opening is gradually increased as the vehicle speed gradually increases. However, because the amount of change in accelerator operation relative to the amount of change in vehicle speed when accelerating at a constant acceleration differs depending on the vehicle type, etc., I became accustomed to the driving method according to the vehicle type where the amount of change in accelerator operation relative to the amount of change in vehicle speed is large. When the driver drives a vehicle type in which the change amount of the accelerator operation with respect to the change amount of the vehicle speed is small, an acceleration greater than the intended acceleration may occur, and the driver may feel uncomfortable.

  The present invention has been made paying attention to the above technical problem, and provides a driving force control device for a vehicle configured to be able to set driving force characteristics in accordance with how the driver operates. It is intended to do.

  In order to achieve the above object, the present invention is configured such that the larger the operation amount of the accelerator device operated by the driver, the larger the target driving force is set, and the higher the vehicle speed is, the smaller the target driving force is set. In the vehicle driving force control apparatus provided with the driving force map, the amount of decrease in the operation amount while the vehicle is accelerating is integrated, and the larger the integrated amount of decrease is, The driving force map is configured to be updated so that the target driving force with respect to the vehicle speed is reduced.

  In this invention, the amount of decrease in the operation amount of the accelerator device during acceleration of the vehicle is integrated, and the larger the amount of decrease, the smaller the target driving force with respect to the vehicle speed in the driving force map, Update the driving force map. Therefore, a driver who is accustomed to driving according to a vehicle type that has a large amount of change in accelerator operation with respect to the amount of change in vehicle speed when accelerating at constant acceleration drives a vehicle type that has a small amount of change in accelerator operation with respect to the amount of change in vehicle speed. In this case, since the driving force characteristic gradually changes so as to become the driving force characteristic corresponding to the manner of driving by the driver, it is possible to generate the acceleration as intended and to suppress a sense of incongruity.

It is a mimetic diagram for explaining an example of a vehicle in an embodiment of this invention. It is a figure for demonstrating an example of the initial state of the driving force map in embodiment of this invention. It is a figure for demonstrating the method of a driver | operator's accelerator operation. It is a flowchart for demonstrating an example of control of the driving force control apparatus in embodiment of this invention. It is a figure for demonstrating an example of the map for calculating | requiring the deviation | shift width | variety of a vehicle speed term. It is the figure which put together the market data of the usage frequency for every accelerator opening. It is a figure for demonstrating the example which updated the driving force map based on the flowchart shown in FIG.

  An example of a vehicle according to an embodiment of the present invention is shown in FIG. A vehicle Ve shown in FIG. 1 includes an engine (ENG) 1 and an automatic transmission (AT) 2 as driving force sources. This engine 1 can be configured in the same manner as a conventionally known gasoline engine or diesel engine, and an electronic slot valve for controlling the intake air amount of the engine 1 or for igniting a mixture of air and fuel. A spark plug or the like is provided. Therefore, the engine 1 can control the output torque of the engine 1 by controlling the opening degree of the electronic throttle valve or controlling the ignition timing by the spark plug. The vehicle in the embodiment of the present invention may be an electric vehicle provided with a motor as a driving force source, or a hybrid vehicle provided with an engine and a motor as driving force sources.

  A vehicle Ve shown in FIG. 1 is a front engine / rear drive type vehicle, and is configured such that the output torque of the engine 1 is transmitted to a pair of rear wheels 3R and 3L. An automatic transmission 2 capable of changing the operating point (mainly the rotational speed) of the engine 1 is provided on a torque transmission path between the engine 1 and the pair of rear wheels 3R and 3L. A torque converter and a torque converter clutch (not shown) may be appropriately provided between the engine 1 and the automatic transmission 2.

  The automatic transmission 2 is a transmission in which a plurality of gear ratios can be set in stages. For example, the automatic transmission 2 transmits driving torque by engaging or releasing an engagement mechanism such as a clutch or a brake (not shown). A stepped automatic transmission configured to execute a shift by changing a route may be provided. The automatic transmission 2 includes a belt-type continuously variable transmission capable of continuously changing a gear ratio by changing a belt wrapping radius with respect to a pulley, a motor having a power generation function, an engine 1 and an output member. May be various transmissions such as a continuously variable transmission configured by a so-called hybrid mechanism in which the motor is connected to a power split mechanism including a differential mechanism and the rotation speed of the engine 1 is continuously changed by the motor.

  A pair of rear wheels 3R, 3L are coupled to the output shaft of the automatic transmission 2 via a propeller shaft 4, a differential gear unit 5, and a pair of drive shafts 6R, 6L.

  The output torque of the engine 1 and the gear position in the automatic transmission 2 are controlled by an electronic control unit (ECU) 7. The ECU 7 is configured mainly with a microcomputer, and is configured to perform calculations using input data or data stored in advance, and output the calculation results as control command signals. The input data includes an accelerator opening sensor 9 that detects the amount of depression of the accelerator pedal 8, a brake sensor 11 that detects the amount of operation of the brake pedal 10 (depression amount and force), a sensor that detects the engine speed, and an automatic shift. Data obtained by the sensor 12 for detecting the rotational speed of the output shaft of the machine 2 and the wheel speed sensor 14 for detecting the rotational speed of each wheel (a pair of front wheels 13R, 13L and a pair of rear wheels 3R, 3L). is there.

  The data stored in advance in the ECU 7 includes a driving force map for obtaining a target acceleration (that is, a target driving force) from an operation amount (accelerator opening) of the accelerator pedal 8, and a shift map for setting a gear position. , Control flow, and arithmetic expressions for performing various data processing based on the input signal.

  Then, an electric signal for controlling a fuel supply valve, a spark plug, or the electronic throttle valve (not shown) is output as a result of performing the data processing by the control flow or the arithmetic expression. As a specific example, an output torque of the engine 1 is obtained from the target acceleration and vehicle speed obtained from the driving force map, and the obtained output torque is output to the electronic throttle valve or spark plug so as to be output from the engine 1. Output a signal. Similarly, when the automatic transmission 2 is a stepped automatic transmission, the gear stage and the gear ratio of the automatic transmission 2 are determined from the target acceleration (target driving force) obtained from the driving force map and the vehicle speed. Then, a signal is output to a device for controlling an engagement mechanism mounted on the stepped automatic transmission so as to set a predetermined gear position. Similarly, signals are output from the ECU 7 to other devices such as a lock-up clutch (not shown).

  Here, an example of the initial state of the driving force map stored in the ECU 7 will be described with reference to FIG. The initial state is the state of the driving force map at the time of vehicle shipment or reset. The driving force map shown in FIG. 2 is configured such that the target acceleration increases proportionally as the accelerator opening increases, and the target acceleration decreases as the vehicle speed increases. ing. On the other hand, the characteristics are different in the low vehicle speed range (for example, less than 80 km / h) and the high vehicle speed range (for example, 80 km / h or more). In the low vehicle speed range, the amount of change in the target acceleration relative to the amount of change in the vehicle speed On the other hand, in the high vehicle speed range, the amount of change in the target acceleration relative to the amount of change in the vehicle speed is set to be relatively small in order to reduce the amount of change in the accelerator opening during acceleration travel. ing.

These relational expressions are simply shown as follows.
Y = aX + b
b = T + αK
In the above equation, Y is the target acceleration, X is the accelerator opening, T and α are predetermined constants that become smaller as the vehicle speed becomes higher, and K is the deviation of the vehicle speed term described later.

  In FIG. 3, a driver who is accustomed to driving a vehicle having a relatively small change in target acceleration with respect to the change in vehicle speed causes the vehicle having the driving force map shown in FIG. The driver is accustomed to driving a vehicle having a relatively large amount of change in target acceleration with respect to the amount of change in vehicle speed, and the driving force map shown in FIG. 2 is provided. A broken line indicates how the accelerator is operated when the vehicle is driven at equal acceleration. 3A shows the magnitude of the accelerator opening, and FIG. 3B shows the rate of change of the accelerator opening.

  When a driver accustomed to driving a vehicle having a relatively small change in target acceleration with respect to a change in vehicle speed as shown by a solid line in FIG. 3 drives a vehicle having the driving force map shown in FIG. First, acceleration is performed with the accelerator opening kept substantially constant, and when the vehicle reaches the vehicle speed intended by the driver, the accelerator opening is reduced.

  On the other hand, when a driver accustomed to driving a vehicle having a relatively large change in target acceleration with respect to the change in vehicle speed drives a vehicle having the driving force map shown in FIG. The opening is gradually increased over time. This is for the driver to increase the accelerator opening as the vehicle speed increases in order to maintain the driving force. On the other hand, according to the driving force map shown in FIG. 2, the target acceleration increases relatively greatly as the accelerator opening increases, so that an acceleration greater than the acceleration intended by the driver is generated. As a result, the driver Decreases the accelerator opening. Next, the accelerator opening is increased again because the acceleration decreases relatively with decreasing the accelerator opening. In other words, the acceleration opening / closing is repeated so as to achieve the acceleration intended by the driver. In such a case, fuel consumption may deteriorate due to factors such as an increase or decrease in the operating point of the engine 1, and it may be difficult for the driver to control the vehicle speed by operating the accelerator.

  Therefore, the driving force control apparatus according to the embodiment of the present invention is configured to update the driving force map in response to an accelerator operation as indicated by a broken line in FIG. An example of the control is shown in FIG. In this control example, first, it is determined whether or not the acceleration a is larger than a predetermined acceleration a_th (step S1). The predetermined acceleration a_th in step S1 is an acceleration determined in advance by experiment or the like, and is an acceleration that the driver can feel as accelerating. The acceleration a of the vehicle Ve may be a value detected by a longitudinal acceleration sensor, or may be a value obtained by differentiating the rotational speeds of the drive shafts 6R and 6L and the output shaft of the automatic transmission 2.

  In this control example, when the depression amount of the accelerator pedal 8 is reduced during a series of acceleration operations from the start of acceleration until steady running or deceleration running, the reduced depression amount is added up to update the drive map. Is configured to do. Therefore, if the acceleration a is greater than the predetermined acceleration a_th and an affirmative determination is made in step S1, it is then determined whether or not the driver is intentionally accelerating. That is, it is determined whether or not the accelerator opening degree pap is larger than “0” (step S2). If the accelerator opening degree pap is larger than “0” and a positive determination is made in step S2, When the accelerator opening pap (n) at the time this routine is executed is subtracted from the accelerator opening pap (n-1) at the time when this routine is executed, and the subtracted value is a negative value Adds the subtraction value (pap (n-1) -pap (n)) to the amount of decrease (integrated value) pap_now of the depression amount of the accelerator pedal 8 during a series of acceleration operations (step S3). In other words, if the accelerator opening pap is decreased during a series of acceleration operations, the rate of change dpap / dt of the accelerator opening pap at the time of the decrease is integrated, and the accelerator during the current series of acceleration operations is integrated. Decrease the amount of pedal depression (hereinafter referred to as the accelerator return amount) pap_now. When the accelerator operation is performed as indicated by a broken line in FIG. 3, the hatched portion in FIG. 3B is the current accelerator return amount pap_now.

  Therefore, in the control example shown in FIG. 4, steps S1 to S3 are repeatedly executed from when the accelerator pedal 8 is depressed to start accelerating until the accelerator pedal 8 is not depressed or until steady running or deceleration running. Is done. Therefore, when the accelerator pedal 8 is kept constant or when the depression amount is increased, the accelerator return amount pap_now of this time does not change, and on the contrary, the depression amount of the accelerator pedal 8 is decreased. If this happens, the corresponding reduction amount is added to the current accelerator return amount pap_now.

  Then, switching from acceleration running to steady running or decelerating running, that is, when the acceleration a becomes equal to or less than the predetermined acceleration a_th is determined negative in step S1, or the accelerator pedal 8 is not depressed, that is, the accelerator If a negative determination is made in step S2 because the opening degree pap is “0”, the current accelerator return amount pap_now is added to the total return amount pap_total stored in the ECU 7 (step S4). A vehicle speed term deviation width K corresponding to the total return amount pap_total is calculated (step S5).

  The vehicle speed term deviation width K is a deviation amount of the target acceleration according to the vehicle speed at a predetermined accelerator opening, and is configured to be set to a larger value as the total return amount pap_total increases. FIG. 5 shows an example of a map for obtaining the deviation width K of the vehicle speed term. In the map shown in FIG. 5, when the total return amount pap_total is “0”, the vehicle speed term deviation width K is set to the predetermined deviation width K1, and the predetermined deviation width K1 is a predetermined value in the initial state. is there. Further, until the total return amount pap_total reaches the predetermined return amount pap_total1, the vehicle speed term deviation width K is determined to increase proportionally as the total return amount pap_total increases from the predetermined deviation width K1. When the predetermined return amount is pap_total1, the vehicle speed term deviation width K is kept constant (upper limit value) K_max. The upper limit value K_max of the vehicle speed term deviation width is a value determined to suppress that the target acceleration cannot be maintained unless the accelerator operation is excessively performed when the vehicle speed increases, and is determined in advance by experiments or the like. .

  Further, the predetermined return amount pap_total1 is determined from market data. Specifically, first, the use frequency for each accelerator opening pap is obtained from the travel data of each vehicle in the market. A graph of the usage frequency for each accelerator opening pap is schematically shown in FIG. Point A in FIG. 6 is an accelerator opening pap1 determined in advance to determine that the driving force should be output, and point B is an average value pap2 of the used accelerator opening determined from market data. is there. The use of the accelerator opening degree pap is the accelerator opening degree pap when the accelerator pedal 8 is continuously depressed for a certain period of time, and the accelerator opening degree that passes through to the target depression amount. Not intended.

  In order to determine the predetermined return amount pap_total1, first, the difference in the accelerator opening (pap2-pap1) between the above points A and B is obtained. Next, the average number of times the accelerator pedal 8 is depressed (accelerator is turned on) per month is calculated from the market data, and the average number is added to the difference in accelerator opening between point A and point B (pap2-pap1). Thus, a predetermined return amount pap_total1 is determined.

  After calculating the vehicle speed term deviation width K based on the map shown in FIG. 5, the vehicle speed term deviation width K is reflected (updated) in the driving force map (step S6). That is, it is substituted into the above equation and stored in the ECU 7. Then, in order to save the data of the next acceleration operation, the currently saved “current accelerator return amount” pap_now data is cleared (step S7), and this routine is once ended.

  FIG. 7 shows an example of the driving force map updated by executing the control example shown in FIG. In FIG. 7, the updated driving force map (only in the high vehicle speed range) is indicated by a solid line, and the driving force map in the initial state (only in the high vehicle speed range) is indicated by a broken line. As shown in FIG. 7, when an operation for reducing the accelerator opening degree pap is performed, the vehicle speed term deviation width K is set to a large value, so that the vehicle speed increases in order to satisfy a certain target acceleration. Accordingly, the accelerator opening degree pap is made larger than the initial state. Therefore, as described above, a driver who is accustomed to driving a vehicle having a relatively small change amount of the target acceleration with respect to the change amount of the vehicle speed has driven the vehicle having the driving force map shown in FIG. However, since the driving force map is gradually updated according to the driving method of the driver, the driver can be prevented from feeling uncomfortable. Moreover, since the engine 1 and the automatic transmission 2 are controlled according to the target acceleration calculated | required by the driving force map, the deterioration of fuel consumption etc. can be suppressed.

  The driving force control apparatus according to the embodiment of the present invention is not limited to updating the driving force map based on the total return amount pap_total. For example, the vehicle speed increases as the number of times the accelerator opening degree pap is decreased during acceleration traveling. You may comprise so that the term shift | offset | difference width K may be enlarged. That is, it is only necessary that the driving force map can be updated using a parameter related to a decrease in the accelerator opening pap during acceleration traveling.

  DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Automatic transmission, 3R, 3L ... Rear wheel, 7 ... Electronic control unit (ECU), 8 ... Accelerator pedal, 9 ... Accelerator opening sensor, 13R, 13L ... Front wheel, 14 ... Wheel speed sensor, Ve ... Vehicle.

Claims (1)

Driving force control of a vehicle provided with a driving force map configured to determine a larger target driving force as the operation amount of the accelerator device operated by the driver is larger and to decrease the target driving force as the vehicle speed is higher In the device
Accumulating the amount of decrease in the operation amount while the vehicle is accelerating,
The driving force of the vehicle is configured to update the driving force map so that the target driving force with respect to the vehicle speed in the driving force map becomes smaller as the integrated decrease amount increases. Control device.

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