JP2005307760A - Driving force controller for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide sense of acceleration demanded by a driver when accelerating at start time of a vehicle. <P>SOLUTION: An engine ECU performs a program including a step (S110) for calculating expected start G or detecting actual front and rear G when determining that start operation is performed (YES at S100), a step (S120) for calculating a scope of expected accelerator pedal return amount from the expected start G or the actual front and rear G, and a step (S140) for changing an electronic throttle in the direction of closing more gently than return change of an accelerator pedal by adding annealing to an electronic throttle return side when accelerator pedal actual return amount is within expected scope (YES at S130). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a control device for a drive source such as an engine and a motor constituting a power train mounted on a vehicle, and more particularly, a vehicle drive capable of improving start characteristics by controlling the drive source when the vehicle starts. The present invention relates to a force control device.

  The vehicle is provided with an accelerator pedal that is operated when the driver wants to accelerate the vehicle. Based on the amount of operation of the accelerator pedal, for example, the opening of the throttle valve of the engine is controlled, and the output of the engine is controlled. In hybrid vehicles, electric vehicles, and fuel cell vehicles, a motor is mounted instead of or in addition to the engine, and the output of this motor is controlled by changing the command signal to the inverter circuit. .

  In the case of an engine, the simplest structure of an accelerator pedal is to mechanically connect the accelerator pedal and the engine throttle valve by a wire. In such a structure, the pedaling force of the accelerator pedal is affected by the return force of the throttle valve and the frictional force of the wire, and a favorable operational feeling cannot be obtained. Therefore, there is a so-called electric control type throttle valve that detects an operation amount of an accelerator pedal as an electric signal and operates an actuator (motor) by this electric signal to control the opening degree of the throttle valve. Regarding such a throttle valve, there is a technique described below.

  Japanese Patent Application Laid-Open No. 59-10750 (Patent Document 1) discloses an engine throttle valve control device which prevents deterioration in riding comfort and fluctuations in vehicle speed due to running vibration or the like. This engine throttle valve control device includes an accelerator opening detector that outputs an accelerator opening signal corresponding to the amount of depression of the accelerator pedal, and a signal that corresponds to the size of the undulation, detecting the undulation state of the road surface of the vehicle. When the road surface undulation is below the set value by comparing the detected output value of the road surface detector with the set value by receiving the accelerator position signal and the detection signal of the road surface detector A first drive signal that opens and closes to a normal opening degree is generated, and a second drive signal that opens and closes the throttle valve to a region where the change amount is smaller than the normal opening degree when the road surface undulation is equal to or greater than a set value. And a control circuit that generates and an actuator that opens and closes the throttle valve in response to the first or second drive signal.

According to this throttle valve control device, in the throttle valve control device of an electric control type engine, an electric signal applied to the actuator of the throttle valve is appropriately signal-processed so that the opening / closing control characteristic of the throttle valve with respect to depression of the accelerator pedal is a desired characteristic. It becomes possible to set to. When traveling on rough roads, the opening / closing operation of the throttle valve with respect to depression of the accelerator pedal is made slow, so that it is possible to prevent deterioration in riding comfort and fluctuations in vehicle speed when traveling on rough roads.
JP 59-10750 A

  However, the throttle valve control device disclosed in Patent Document 1 merely slows the operation of the throttle valve with respect to the amount of depression of the accelerator pedal when the road surface undulation is equal to or greater than a predetermined value. For this reason, the following problems cannot be solved.

  When the vehicle is stopped (if the transmission has a transmission, the transmission is in a power transmission state) and the driver depresses the accelerator pedal, the engine speed increases and the drive torque is transmitted to the drive wheels of the vehicle. The vehicle starts. At this time, acceleration that travels forward acts on the vehicle. On the other hand, the driver tries to stay at a position before the vehicle accelerates due to the law of inertia. Therefore, when the vehicle starts to move, the vehicle moves forward, and the driver feels a force behind the vehicle (feels pressed against the seat). At this time, the force with which the driver steps on the accelerator pedal temporarily decreases. This is because the driver's foot is forced to stay in the place by the law of inertia, and thus the driver's foot depresses the accelerator pedal once. Since the driver is unaware of such looseness of stepping on the accelerator pedal, the behavior of the vehicle requested (predicted) by the driver is different.

  That is, when the vehicle starts, when the vehicle accelerates, the force of stepping on the accelerator pedal with the foot is loosened due to the law of inertia, the accelerator is turned off and the acceleration is loosened, and the driver does not intentionally return the accelerator pedal Nevertheless, a situation occurs in which the driver's request and the behavior of the vehicle do not match, such as a decrease in the acceleration of the vehicle.

  It is assumed that the stroke amount of the accelerator pedal and the torque fluctuation amount of the power source (engine, motor, engine receiving motor assist, etc.) are in a proportional relationship. In other words, the larger the stroke when the accelerator pedal is depressed, the greater the torque generated from the engine or motor, and the smaller the stroke when the accelerator pedal is depressed, the smaller the torque generated from the engine or motor. It is assumed that.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a vehicle driving force capable of expressing the acceleration feeling required by the driver even during acceleration such as when the vehicle starts. It is to provide a control device.

  A vehicle driving force control apparatus according to a first aspect of the present invention controls a vehicle driving force that changes the driving force of the vehicle based on an operation amount of an accelerator pedal. This control device includes a detecting means for detecting an accelerator pedal operation amount of a vehicle, a calculating means for calculating a threshold value of an accelerator pedal return amount from the accelerator pedal operation amount, and an actual accelerator pedal return amount. Control means for controlling the drive source so that the change in the output of the drive source of the vehicle is moderate with respect to the change in the accelerator pedal operation amount on the return side of the accelerator pedal when the threshold value is smaller than the threshold value; Including.

  According to the first invention, the output of the driving source of the vehicle is controlled without following the change in the operation amount of the accelerator pedal. For example, when the driver depresses the accelerator pedal for the first time during sudden acceleration of the vehicle (starting, etc.), the output (torque) of the engine or motor that is the driving source of the vehicle increases, and the vehicle accelerates (starts). To do. On the other hand, the driver tries to stay at a position before the vehicle accelerates (starts) according to the law of inertia. Therefore, when the vehicle starts to move, the vehicle moves forward, and the driver feels a force behind the vehicle (feels pressed against the seat). At this time, the force of stepping on the accelerator pedal is relaxed without the driver being conscious. For this reason, although the driver is not conscious that the accelerator pedal has been loosened, the acceleration of the vehicle decreases. For this reason, when the actual accelerator pedal return amount is smaller than the threshold value by the control means (when the actual accelerator pedal return amount is larger than the threshold value, the driver consciously returns the accelerator pedal), the accelerator pedal On the return side, the drive source is controlled so that the change in the output of the drive source of the vehicle becomes moderate with respect to the change in the accelerator pedal operation amount. In this way, even if the driver unconsciously returns the accelerator pedal, the output of the drive source does not decrease in response to the return of the accelerator pedal, but can be decreased gradually. Therefore, the difference between the driver's intention and the behavior of the vehicle can be suppressed, and the acceleration performance (starting performance) can be improved. As a result, it is possible to provide a driving force control device for a vehicle that can express the feeling of acceleration required by the driver even during sudden acceleration of the vehicle.

  In the driving force control apparatus for a vehicle according to the second invention, in addition to the configuration of the first invention, the vehicle changes the opening degree of the throttle valve provided in the driving source based on the operation amount of the accelerator pedal. It is a vehicle. The control means includes means for controlling the throttle valve so that the change of the throttle valve becomes gentle with respect to the change of the accelerator pedal operation amount.

  According to the second aspect of the invention, the intake air amount to the engine that is the drive source of the vehicle is changed without following the change in the operation amount of the accelerator pedal. That is, the output of the engine is controlled by controlling the opening of a throttle valve that changes the amount of intake air into the engine. Even when the vehicle suddenly accelerates (such as when starting), an inertial force acts, and even if the driver depresses the force to step on the accelerator pedal, the change on the throttle valve closing side is gradually changed. In this way, even if the accelerator pedal is returned unconsciously by the driver, the output of the engine does not decrease in response to the return of the accelerator pedal, but can be reduced gradually.

  The driving force control apparatus for a vehicle according to the third invention further includes acceleration detection means for detecting acceleration acting on the vehicle, in addition to the configuration of the first or second invention. The calculating means includes means for calculating a threshold value of the accelerator pedal return amount from the detected acceleration.

  According to the third invention, the threshold value of the accelerator pedal return amount is used to determine whether the driver has unconsciously returned the accelerator pedal or whether the driver has consciously returned the accelerator pedal due to inertial force. It is done. The longitudinal acceleration acting on the vehicle is detected by a G (hereinafter, G means acceleration) sensor or the like, and the threshold value is calculated to increase as the acceleration increases. In this way, as the acceleration increases, the inertial force increases and the amount of return of the accelerator pedal that the driver is not aware of increases. If the threshold value of the accelerator pedal return amount is calculated from the acceleration, it can be accurately determined whether or not the driver has returned with the accelerator pedal in mind.

  In the vehicle driving force control apparatus according to the fourth aspect of the invention, in addition to the configuration of the third aspect of the invention, the acceleration detection means detects the acceleration by calculating the acceleration using the accelerator pedal operation amount. Including means.

  According to the fourth invention, the longer the accelerator pedal is depressed, the greater the longitudinal acceleration acting on the vehicle, and the smaller the accelerator pedal is depressed, the smaller the longitudinal acceleration acting on the vehicle. For this reason, the acceleration for calculating the threshold value of the accelerator pedal return amount can be obtained using the accelerator pedal operation amount without using the G sensor or the like.

  In the vehicle driving force control apparatus according to the fifth aspect of the invention, in addition to the configuration of any one of the first to fourth aspects of the invention, when the actual accelerator pedal return amount is not smaller than the threshold, Means for controlling the drive source so as to change the output of the drive source of the vehicle in response to a change in the accelerator pedal operation amount on the return side of the accelerator pedal is included.

  According to the fifth invention, when the actual accelerator pedal return amount is larger than the threshold value, it can be determined that the driver has consciously returned the accelerator pedal. In such a case, on the return side of the accelerator pedal, the drive source is controlled so as to change the output of the drive source of the vehicle in response to the change in the accelerator pedal operation amount. In this way, when the driver consciously returns the accelerator pedal, the output of the drive source can be quickly reduced. Therefore, the difference between the driver's intention and the behavior of the vehicle can be suppressed, and the acceleration performance (starting performance) can be improved. As a result, it is possible to provide a driving force control device for a vehicle that can express the feeling of acceleration required by the driver even during rapid acceleration of the vehicle (when starting, etc.).

  In the vehicle driving force control apparatus according to the sixth aspect of the invention, in addition to the configuration of any one of the first to fifth aspects, the driving force control by the control means is executed when the vehicle starts.

  According to the sixth aspect of the present invention, the acceleration performance (starting performance) can be improved by suppressing the difference between the driver's intention and the behavior of the vehicle, particularly at the time of starting with a large change in acceleration.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  A power train of a vehicle including the driving force control apparatus according to the present embodiment will be described. The driving force control apparatus according to the present embodiment is realized by a program executed by an ECU (Electronic Control Unit) 1000 shown in FIG. In the present embodiment, the drive source is described as an engine. However, the present invention is not limited to the engine only, the engine and the motor, and the motor alone. The automatic transmission will be described as an automatic transmission having a gear-type transmission mechanism provided with a torque converter as a fluid coupling. Note that the present invention is not limited to an automatic transmission having a gear-type transmission mechanism, and may be a continuously variable transmission such as a belt type. Further, a manual transmission having a manual clutch and a gear transmission mechanism instead of the torque converter and the gear transmission mechanism may be used.

  Specifically, the driving force control apparatus according to the present embodiment is realized by engine ECU 1010 shown in FIG. As shown in FIG. 1, the power train of this vehicle includes an engine 100, a torque converter 200, and an automatic transmission 300.

  The output shaft of engine 100 is connected to the input shaft of torque converter 200. Engine 100 and torque converter 200 are connected by a rotating shaft. Therefore, output shaft rotational speed NE (engine rotational speed NE) of engine 100 detected by the engine rotational speed sensor and input shaft rotational speed (pump rotational speed) of torque converter 200 are the same.

  The torque converter 200 is supported by the case via a lockup clutch that directly connects the input shaft and the output shaft, a pump impeller on the input shaft side, a turbine impeller on the output shaft side, and a one-way clutch. And a stator that exhibits a torque amplification function. Torque converter 200 and automatic transmission 300 are connected by a rotating shaft. The output shaft rotational speed NT (turbine rotational speed NT) of the torque converter 200 is detected by a turbine rotational speed sensor. The output shaft rotational speed NOUT of the automatic transmission 300 is detected by an output shaft rotational speed sensor.

  Such an automatic transmission 300 includes a plurality of friction elements such as clutches and brakes. Based on a predetermined operation table, clutch elements (for example, clutches C1 to C4) that are friction elements, brake elements (for example, brakes B1 to B4), and one-way clutch elements (for example, one-way clutches F0 to F3) are required. The hydraulic circuit is controlled so as to be engaged and released corresponding to each gear stage. Shift positions (shift positions) of the automatic transmission 300 include a parking (P) position, a reverse travel (R) position, a neutral (N), and a forward travel (D) position.

  The ECU 1000 that controls these power trains includes an engine ECU 1010 that controls the engine 100 and an ECT (Electronically Controlled Automatic Transmission) _ECU 1020 that controls the automatic transmission 300.

  ECT_ECU 1020 receives a signal representing output shaft rotational speed NOUT detected by the output shaft rotational speed sensor. ECT_ECU 1020 receives an engine speed signal representing engine speed NE detected by the engine speed sensor from engine ECU 1010.

  These rotation speed sensors are provided to face the teeth of the rotation detection gear attached to the input shaft of torque converter 200, the output shaft of torque converter 200, and the output shaft of automatic transmission 300. Here, these rotational speed sensors are sensors that can detect slight rotations of the input shaft of the torque converter 200, the output shaft of the torque converter 200, and the output shaft of the automatic transmission 300. It is a sensor using a magnetoresistive element called a type sensor.

  Further, ECT_ECU 1020 outputs an engine control signal to engine ECU 1010, and engine ECU 1010 controls engine 100 (for example, an electronic throttle) based on the engine control signal and other control signals. ECT_ECU 1020 outputs a lockup clutch control signal for torque converter 200. Based on this lockup clutch control signal, the engagement pressure of the lockup clutch is controlled. As a result, the lockup clutch is engaged (on), released (off), or slipped in the middle.

  The ECT_ECU 1020 outputs a solenoid control signal to the automatic transmission 300. Based on this solenoid control signal, the linear solenoid valve, the on-off solenoid valve, etc. of the hydraulic circuit of the automatic transmission 300 are controlled, and friction is established so as to constitute a predetermined shift gear stage (for example, first speed to fifth speed). The engagement element is controlled to be engaged and released.

  Engine ECU 1010 receives a signal indicating acceleration acting in the longitudinal direction of the vehicle from longitudinal G sensor 2000. Engine ECU 1010 receives a signal indicating the opening of the accelerator pedal from accelerator opening sensor 2100. ECU 1000 has a memory in which various data and programs are stored. Engine ECU 1000 executes a predetermined calculation based on the input accelerator pedal opening and acceleration acting in the longitudinal direction of the vehicle, and outputs an electronic throttle control signal to engine 100 to The opening degree is controlled, the output of the engine 100 is controlled, and the driving force of the vehicle is controlled. When a motor is installed instead of the engine, or when a motor is installed in addition to the engine, the ECU changes the command signal to the inverter circuit connected to the traveling battery and the traveling motor. The driving force of the vehicle is controlled.

  With reference to FIG. 2, a control structure of a program executed by engine ECU 1010 realizing the vehicle driving force control apparatus according to the present embodiment will be described.

  In step (hereinafter, step is abbreviated as S) 100, engine ECU 1010 determines whether or not a start operation has been performed based on a signal from accelerator opening sensor 2100. Engine ECU 1010 may determine whether or not a start operation has been performed based on a signal other than that input from accelerator opening sensor 2100. If vehicle start operation is performed (YES in S100), the process proceeds to S110. Otherwise (NO in S100), this process ends.

  In S110, engine ECU 1010 calculates expected start G or detects actual front and rear G. At this time, the engine ECU 1010 calculates an expected start G based on the accelerator pedal position input from the accelerator position sensor 2100, or detects the actual front / rear G based on a signal input from the front / rear G sensor 2000. To do.

  In S120, engine ECU 1010 calculates a predicted accelerator pedal return amount range from predicted start G or actual front and rear G. At this time, based on the map as shown in FIG. 3, the expected range (shaded portion) of the accelerator pedal return amount is calculated from the longitudinal direction G (predicted value or measured value) of the vehicle. When the accelerator pedal is returned further than the lower limit value of the expected range of the return amount of the accelerator pedal, the driver has intentionally returned the accelerator pedal. In the process in S120, the expected accelerator pedal return amount range is calculated based on the relationship between the vehicle longitudinal direction G and the accelerator pedal return amount in FIG. The range of the expected accelerator pedal return amount may be calculated.

  In S130, engine ECU 1010 determines whether or not the actual accelerator pedal return amount is within an expected range. At this time, engine ECU 1010 determines whether or not the actual return amount of the accelerator pedal is within an expected range based on the actual return amount of the accelerator pedal input from accelerator opening sensor 2100. If the accelerator pedal actual return amount is within the expected range (YES in S130), the process proceeds to S140. Otherwise (NO at S130), this process ends.

  In S140, engine ECU 1010 smoothes the electronic throttle (driving force) return side. This means that, instead of changing the electronic throttle to the closing side in response to the return state of the accelerator pedal, the electronic throttle is changed to the closing side more slowly than the method of returning the accelerator pedal.

  The operation of the vehicle equipped with the vehicle driving force control apparatus according to the present embodiment based on the structure and flowchart as described above will be described.

[When the driver unintentionally returns the accelerator pedal]
A start operation is performed (YES in S100), and an expected start G is calculated or an actual front / rear G is detected (S110), and the predicted accelerator pedal return amount range from the calculated expected start G or the detected actual front / back G Is calculated using the map shown in FIG. 3 (S120). The actual return amount of the accelerator pedal is less than the expected range because the driver unconsciously eases the stepping on the accelerator pedal (YES in S130).

  In such a case, the engine ECU 1010 generates an electronic throttle control signal so as to smooth the electronic throttle return side, and controls the throttle valve (S140).

  FIG. 4 (A) shows the temporal change of the front and rear G when such control is performed, FIG. 4 (B) shows the temporal change of the accelerator pedal opening, and FIG. 4B shows the temporal change of the electronic throttle opening. Each is shown in 4 (C).

  As shown in FIG. 4B, after the accelerator pedal opening is once largely opened, the driver unconsciously returns the accelerator pedal opening within the expected accelerator pedal return amount range (in S130). YES). In such a case, as shown in FIG. 4 (C), the opening degree of the electronic throttle is conventionally changed corresponding to the change of the opening degree of the accelerator pedal as shown by the one-dot chain line. The engine ECU 1010 according to the embodiment adds smoothing to the electronic throttle return side, and the opening degree of the electronic throttle is gradually reduced. For this reason, as shown in FIG. 4 (A), the front and rear G acting on the vehicle, as shown by the alternate long and short dash line in the prior art, rapidly decreases even though the driver has not intentionally loosened the accelerator pedal. However, in the present invention, as shown by the solid line, the longitudinal G gradually decreases, and when the driver unconsciously returns the accelerator pedal, it is avoided that the longitudinal G acting on the vehicle suddenly decreases. Can do.

  That is, as shown by the one-dot chain line in FIG. 4A, the front and rear G acting on the vehicle are greatly reduced, and the accelerator pedal returns unconsciously, but the engine ECU 1010 returns the accelerator pedal opening degree. If the amount is within the range of the expected accelerator pedal return amount, the driver determines that the accelerator pedal has been unintentionally returned, and gently changes the degree of opening of the electronic throttle (applies smoothing). By doing in this way, the front-back G which acts on a vehicle can be reduced gently.

[When the accelerator pedal is consciously returned]
If the driver consciously returns the accelerator pedal during the start operation of the vehicle (NO in S130), the opening of the electronic throttle is controlled in accordance with the driver's operation of the accelerator pedal. FIG. 5A shows the temporal change in the accelerator pedal opening in such a case, and FIG. 5B shows the temporal change in the electronic throttle opening.

  As shown in FIG. 5A, since the driver consciously returned the accelerator pedal, at time T (2), the accelerator pedal changes to the closed side exceeding the expected accelerator pedal return amount range. Until time T (2), the opening of the electronic throttle is controlled by smoothing the electronic throttle return side, but after time T (2), as shown in FIG. In response to changes in the accelerator pedal opening, the opening of the electronic throttle is drastically reduced. In addition, the dashed-dotted line shown to FIG. 5 (B) is a case where the actual return amount of an accelerator pedal exists in the estimated amount return range of an accelerator pedal (when annealing is added).

  Thus, when the driver intentionally returns the accelerator pedal, the opening of the electronic throttle is changed in response to the change of the accelerator pedal by the driver, so that the driver's intention can be reflected. .

  As described above, according to the driving force control apparatus for a vehicle according to the present embodiment, when the vehicle decelerates (accelerated), the inertial force reduces the driver's stepping force on the accelerator pedal. The engine output of the vehicle is controlled without following the change in the operation amount of the accelerator pedal. As a result, even if the driver does not consciously return the accelerator pedal, the engine torque does not change abruptly and the acceleration feeling required by the driver can be expressed.

  In the present embodiment, the case of starting the vehicle has been described as an example. However, the present invention is not limited to the time of starting the vehicle, and the vehicle may be traveling.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is a control block diagram of a vehicle including a vehicle driving force control device according to an embodiment of the present invention. It is a flowchart which shows the control structure of the program performed with ECU which is the driving force control apparatus of the vehicle which concerns on embodiment of this invention. It is a figure which shows the relationship between the front-back direction G of a vehicle, and an accelerator pedal return amount. It is a figure which shows the time change of the vehicle front-back G, the accelerator pedal opening degree, and the electronic throttle opening degree which are controlled by the driving force control apparatus of the vehicle which concerns on embodiment of this invention. It is a figure which shows the time change of the accelerator pedal opening of a vehicle controlled by the driving force control apparatus of the vehicle which concerns on embodiment of this invention, and an electronic throttle opening.

Explanation of symbols

  100 engine, 200 torque converter, 300 automatic transmission, 1000 ECU, 1010 engine ECU, 1020 ECT_ECU, 2000 front and rear G sensor, 2100 accelerator opening sensor.

Claims (6)

A vehicle driving force control device that changes the driving force of a vehicle based on an operation amount of an accelerator pedal,
Detection means for detecting the accelerator pedal operation amount of the vehicle;
A calculation means for calculating a threshold value of an accelerator pedal return amount from the accelerator pedal operation amount;
When the actual return amount of the accelerator pedal is smaller than the threshold value, on the return side of the accelerator pedal, the drive so that the change in the output of the vehicle drive source becomes moderate with respect to the change in the accelerator pedal operation amount. And a driving means for controlling the vehicle. The vehicle is a vehicle that changes an opening degree of a throttle valve provided in the drive source based on an operation amount of an accelerator pedal,
2. The vehicle driving force control device according to claim 1, wherein the control means includes means for controlling the throttle valve such that a change in the throttle valve becomes gentle with respect to a change in an accelerator pedal operation amount. 3. . The driving force control device further includes acceleration detection means for detecting acceleration acting on the vehicle,
The vehicle driving force control device according to claim 1, wherein the calculating means includes means for calculating a threshold value of an accelerator pedal return amount from the detected acceleration.   4. The vehicle driving force control device according to claim 3, wherein the acceleration detecting means includes means for detecting the acceleration by calculating an acceleration using the accelerator pedal operation amount.   When the actual accelerator pedal return amount is not smaller than the threshold value, the control means changes the output of the driving source of the vehicle in response to the change in the accelerator pedal operation amount on the return side of the accelerator pedal. The vehicle driving force control device according to claim 1, comprising means for controlling the driving source. The driving force control device for a vehicle according to any one of claims 1 to 5, wherein the driving force control by the control means is executed when the vehicle starts.

Images