JP4640141B2 - Vehicle driving force control device - Google Patents

Description

  The present invention relates to a driving force control device for a vehicle in which a driving source and a transmission are mounted, and more particularly, to suppress the torsional vibration of a driving system at the time of acceleration of the vehicle and meet the driver's preference. The present invention relates to a device for controlling driving force.

  In a vehicle, an unpleasant vibration is often generated from the drive system at the time of acceleration when the engine load is increased. This unpleasant vibration is mainly caused by the torsional vibration of the drive shaft in the drive system, and is generated when the engine torque increased as the engine load increases includes the resonance frequency component of the drive system. The resonance frequency is different for each gear ratio of the transmission.

  Japanese Patent Laying-Open No. 2003-41987 (Patent Document 1) discloses a control device that reliably detects an acceleration mode including the resonance frequency of such a drive system and reduces vibration. The control device includes an accelerator opening detecting means for detecting a value related to the accelerator opening, an engine speed detecting means for detecting a value related to the engine speed, and a driver based on a detection result of the accelerator opening detecting means. When it is detected that an accelerator opening increase operation has been performed, a time of a value related to the engine load in a predetermined period from the accelerator opening increasing operation based on a value related to the engine speed and a value related to the accelerator opening Engine load change prediction means for predicting a change, filter means for extracting a resonance frequency component of a vehicle drive system from a time change of a value related to the engine load predicted by the engine load change prediction means, and extracted by the filter means Reduce the engine torque corresponding to the resonance frequency component at the timing corresponding to the resonance frequency component. And a torque reducing means for.

According to this control device, the engine torque is reduced so as to reduce the extracted resonance frequency component by extracting the resonance frequency component of the drive system from the time change of the value related to the engine load that is predicted to be realized. In addition, it is possible to reliably reduce the vibration of the drive system caused by the resonance frequency component while reliably grasping at the time of acceleration that the vibration of the drive system is generated because the resonance frequency component is included.
Japanese Patent Laid-Open No. 2003-41987

  The torsional vibration of the drive system becomes more prominent as the gear ratio is larger (lower gear stage) and as the engine speed is higher. Therefore, in such a low gear stage / high rotation region, it is conceivable to set a relatively large gain in the filter that extracts the resonance frequency component of the drive system from the predicted engine load change.

  However, when trying to remove the resonant frequency component that causes the torsional vibration of the drive system by uniformly increasing the gain, the driver requests acceleration with high responsiveness in the low gear stage and high rotation range. Also in many cases (when sports driving preference is strong), the responsiveness will be lowered, which may not be preferable.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to realize an acceleration feeling that matches a driver's preference and suppress vibration of a drive system. The driving force control device is provided.

  A driving force control apparatus for a vehicle according to a first aspect of the present invention is a driving force setting means for setting a driving force to be generated in the vehicle, and for predicting a vibration due to the generation of the driving force set by the driving force setting means. The vibration prediction means, the adjustment means for adjusting the set driving force so as to reduce the vibration component predicted by the vibration prediction means, the detection means for detecting the driving preference of the driver, and the adjustment Correction means for correcting the generated driving force in accordance with the driving preference.

  According to the first invention, the driving force of the driving source such as the engine is set based on the accelerator opening degree operated by the driver. A vibration (particularly a torsional vibration of the drive system due to the resonance frequency) generated by expressing the set driving force is predicted. The set driving force is adjusted so as to reduce the predicted vibration component. At this time, if the vibration component is further reduced, the driving force tends to be greatly reduced, resulting in a decrease in acceleration response. On the other hand, if the acceleration response is not lowered, the driving force cannot be greatly reduced, and the vibration component cannot be further reduced. In such a case, if the driver's driving preference is a sports preference, the driving force is controlled so that the driving force does not decrease (prioritizing vibration suppression). If the driver's driving preference is not a sports preference, the driving force is controlled so that the driving force becomes small (prioritizing vibration suppression). As a result, it is possible to provide a driving force control device for a vehicle that can realize an acceleration feeling that matches the driver's preference and that can suppress vibration of the driving system.

  In the vehicle driving force control apparatus according to the second aspect of the invention, in addition to the configuration of the first aspect of the invention, the adjusting means adjusts the driving force set so as to reduce the vibration component predicted by the vibration prediction means. Filtering means for filtering is included, and the correction means includes calculation means for multiplying a value using the driving force filtered by the filtering means by a gain according to driving preference.

  According to the second invention, when a value using the filtered driving force (for example, a difference value between the set driving force and the filtered driving force) is multiplied by a large gain, the torsional vibration is further suppressed and accelerated. The feeling decreases, and if a small gain is multiplied, the torsional vibration is not suppressed more, but the acceleration feeling is improved. For this reason, the gain can be set according to the driving preference, and the driving force matched with the driving preference can be expressed.

  In the vehicle driving force control apparatus according to the third aspect of the invention, in addition to the configuration of the second aspect of the invention, the computing means is for multiplying the difference value between the set driving force and the filtered driving force by a gain. Including means.

  According to the third invention, when the difference between the set driving force and the filtered driving force is multiplied by a large gain, the torsional vibration is further suppressed and the acceleration feeling is reduced. When the small gain is multiplied, the torsional vibration is Although not more suppressed, the feeling of acceleration is improved. For this reason, the gain can be set according to the driving preference, and the driving force matched with the driving preference can be expressed.

  In the vehicle driving force control apparatus according to the fourth aspect of the invention, in addition to the configuration of the second or third aspect of the invention, the calculation means multiplies a gain that decreases as the driver's driving preference is in the direction of emphasis on power performance. Including means.

  According to the fourth aspect of the invention, the gain becomes smaller as the power performance is emphasized, so that the torsional vibration is not further suppressed, but the acceleration feeling can be improved, and an acceleration feeling that matches the driver's preference can be realized.

  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.

  FIG. 1 illustrates a power train of a vehicle including an ECU that is a control device according to an embodiment of the present invention.

  As shown in FIG. 1, the vehicle includes an engine 100, a torque converter 200, an automatic transmission 300, an ECU (Electronic Control Unit) 500 that controls these, and a signal that indicates an opening degree of an accelerator pedal to the ECU 500. , And a sports travel switch 700 for inputting a degree (level) of the driver's preference for sports travel.

  In the following description, the driving force control applied to the power train having the engine 100, the torque converter 200, and the automatic transmission 300 as shown in FIG. 1 will be described, but the present invention is not limited to this. is not. There may be a motor that assists the engine 100. In this case, the motor is a motor generator and also functions as a drive wheel or a generator driven by the engine 100.

  ECU 500 outputs a control signal such as a throttle opening command signal to engine 100 and receives a detection signal such as an engine speed signal.

  ECU 500 also outputs a control signal that commands engagement or release (including slip) of the lock-up clutch of torque converter 200. In addition, ECU 500 outputs a control signal that is a hydraulic pressure command signal to automatic transmission 300, or a detection signal such as an output shaft rotation number signal is input from automatic transmission 300. ECU 500 can detect the vehicle speed based on the output shaft rotation speed signal.

  Many automatic transmissions include a fluid coupling and a gear-type stepped transmission mechanism or a belt-type or traction-type continuously variable transmission mechanism. In FIG. 1, the transmission mechanism is described as an automatic transmission 300. Further, as a fluid coupling, there is a torque converter 200, and this torque converter 200 includes a lock-up clutch. The lock-up clutch mechanically directly connects the drive side member (pump impeller on the engine 100 side) and the driven side member (turbine liner on the automatic transmission 300 side) of the torque converter 200. Therefore, both improvement in fuel consumption and riding comfort can be achieved. A lockup region in which such a lockup clutch is engaged is normally set based on, for example, the vehicle speed and the throttle opening.

  The accelerator pedal opening sensor 600 detects the opening of the accelerator pedal operated by the driver. Instead of the accelerator pedal opening sensor 600, a throttle valve opening sensor may be used.

  The sport travel switch 700 is configured so that the driver can input a degree of preference for sport travel (for example, 10 levels in the present embodiment). When the torsional vibration suppression control during acceleration is being executed according to the degree of preference for the input sport running, the acceleration that acts on the vehicle is determined, and the final required driving force is calculated. The power train is controlled so that this final driving force is generated. In addition, the case of level 0 is a case where the sport mode is OFF, and the case of level 10 is the case where the sport driving preference is strongest.

  Note that the ECU 500 may automatically acquire the degree to which the driver desires sport driving. For example, the ECU 500 obtains the current position information from the navigation system, detects the lateral G value at the corner when no forward vehicle is detected in front of the corner, and the average value of the detected lateral G value is equal to or greater than the threshold value. If this is the case, it is determined that the driver has a sport driving preference that allows the driver to receive a strong lateral G during cornering. In this way, the driver's driving behavior (brake pedaling amount, acceleration / deceleration state, lateral G value, etc.) can be analyzed to automatically acquire the degree to which the driver desires sports driving. Further, ECU 500 obtains current position information from the navigation system, and determines that there is a sport driving preference when the position is a circuit. In any case, the level of the sport travel switch 700 is set based on the sport travel preference automatically acquired by the ECU 500.

  Furthermore, ECU 500 executes torsional vibration suppression control during acceleration. Hereinafter, the torsional vibration suppression control during acceleration will be described. The torsional vibration suppression control during acceleration is not limited to the control mode described below.

  When the accelerator pedal of the vehicle is stepped in step response, the torque generated by the engine 100 includes substantially all frequency components. Therefore, the resonance frequency component of the drive system during acceleration is also included. On the other hand, there is a resonance frequency of the drive system for each gear ratio. The resonance frequency can be assumed to be around 2 Hz at the first speed, around 4 Hz at the second speed, around 6 Hz at the third speed, around 8 Hz at the fourth speed, and around 10 Hz at the fifth speed. Such resonance frequencies of 2 Hz to 10 Hz are all included when the accelerator pedal is stepped on.

  In order to prevent vibration of the drive system at the time of acceleration, ECU 500 predicts a time change in the load of engine 100 that would be realized by the acceleration based on the vehicle speed and gear ratio at the start of acceleration, for example. The frequency component of the vibration generated thereby is predicted. A resonance frequency component corresponding to the gear ratio is extracted from the generated vibration frequency components, and control is performed so as to reduce the torque (driving force) of engine 100 by the amount of the extracted resonance frequency component torque.

  The driving force control including the torsional vibration suppression control during acceleration will be described with reference to FIG. As shown in FIG. 2, first, the base required driving force F (base) based on the accelerator opening is calculated. The base required drive force F (base) is requested using a filter (resonance frequency elimination filter, the above-described bandpass filter) for removing the resonance frequency component for suppressing the torsional vibration during acceleration described above. A force F (1) is calculated. At this time, the vehicle speed and the gear stage of the automatic transmission 300 are used.

  This embodiment is characterized by subsequent processing. A required driving force difference ΔF1 (1) by the filter is calculated by subtracting the required driving force F (1) after filtering of the resonance frequency from the above-described base required driving force F (base). That is, the required driving force difference ΔF (1) by the filter is calculated by F (base) −F (1). The required driving force difference ΔF (1) by this filter is multiplied by the notch filter gain G, and the required driving force difference ΔF (2) after gain reflection is calculated. That is, the required driving force difference ΔF (2) by the filter is calculated by G × ΔF (1) = G × {F (base) −F (1)}.

  The final required driving force F (2) is calculated by subtracting the required driving force difference ΔF (2) by the filter from the base required driving force F (base) described above. Therefore, the final required driving force F (2) is adjusted by the notch filter gain G due to the influence of the resonance frequency elimination filtering.

  As shown in FIG. 3, the notch filter gain G is expressed as a function of the sport running level. The sport driving level 1 is the lowest degree of preference for sports driving (except for the sport mode OFF at level 0), and the notch filter gain G is close to 1. As the sport driving level increases, the degree of preference for sport driving increases and the notch filter gain G approaches zero. Level 10 is selected when the circuit travels. When the notch filter gain G is 1, the influence of the resonance frequency removal filtering is reflected as it is, and when the notch filter gain G is 0, the influence of the resonance frequency removal filtering is not reflected at all.

  A larger setting of the notch filter gain G is preferable from the viewpoint of removing the resonance frequency, but is not preferable from the viewpoint of vehicle response. Conversely, the smaller the notch filter gain G is, the less preferable it is from the viewpoint of removing the resonance frequency, but it is preferable from the viewpoint of vehicle response.

  With reference to FIG. 4, a control structure of a program executed by ECU 500 that is the control device according to the present embodiment will be described.

  In step (hereinafter step is abbreviated as S) 100, ECU 500 determines whether or not acceleration torsional vibration suppression control is being executed. If acceleration torsional vibration suppression control is being executed (YES in S100), the process proceeds to S200. Otherwise (NO in S100), this process ends.

  In S200, ECU 500 reads the level of sport travel switch 700. At this time, as described above, the ECU 500 not only reads the sports driving level, which is the degree to which the driver desires sports driving, input from the sports driving switch 700 operated by the driver, but also automatically acquired driving. The sports driving level may be read regardless of the level input to the sports driving switch 700 based on the degree to which the person desires sports driving.

  In S300, ECU 500 determines whether or not the sport mode is OFF. Whether or not the sport mode is OFF can be determined based on whether or not the level input to the sport travel switch 700 is zero. If sport mode is OFF (YES in S300), the process proceeds to S500. If not (NO in S300), the process proceeds to S400.

  In S400, ECU 500 calculates notch filter gain G by G = f (level) (f is a function as shown in FIG. 3). In S500, ECU 500 calculates notch filter gain G as G = 1.

  An operation of ECU 500 serving as the control device according to the present embodiment based on the above-described structure and flowchart will be described.

  If acceleration torsional vibration suppression control is being executed while the vehicle is traveling (YES in S100), a sports travel level that is the degree to which the driver likes sports travel is read (S200).

[When sports driving level is 0]
If notch (level) of sport travel switch 700 is 0, it is determined that sport mode is OFF (YES in S300), and notch filter gain G is set to 1. As a result, the required driving force difference ΔF (2) by the filter is calculated by 1 × ΔF (1) = 1 × {F (base) −F (1)}, and thus the required driving force after the resonance frequency elimination filtering. F (1) can be reflected most. Since the final required driving force F (2) is calculated by F (base) −ΔF (2), the final required driving force F (2) when the notch filter gain G is set to 1 is the resonance frequency elimination. It is calculated to be small with the greatest influence from filtering. As a result, the response to the running of the vehicle is reduced, but the torsional vibration during acceleration is most effectively suppressed.

[When sports driving level is low]
If the notch (level) of sport travel switch 700 is not 0 but small, it is not determined that sport mode is OFF (NO in S300), but notch filter gain G is set to a value close to 1. As a result, the required driving force difference ΔF (2) by the filter is calculated by f (level) × ΔF (1) = (value close to 1) × {F (base) −F (1)}. The required driving force F (1) after frequency removal filtering can be largely reflected. Since the final required driving force F (2) is calculated by F (base) −ΔF (2), the final required driving force F (2) when the notch filter gain G is set to a value close to 1 is It is greatly influenced by the resonance frequency removal filtering and tends to be calculated small. As a result, priority is not given to the response of the vehicle traveling, but torsional vibration during acceleration is effectively suppressed.

[When sports driving level is high]
If the notch (level) of sport travel switch 700 is not 0 but large, it is not determined that sport mode is OFF (NO in S300), and notch filter gain G is set to a value close to 0. As a result, the required driving force difference ΔF (2) by the filter is calculated by f (level) × ΔF (1) = (value close to 0) × {F (base) −F (1)}. The required driving force F (1) after frequency removal filtering cannot be largely reflected. Since the final required driving force F (2) is calculated by F (base) −ΔF (2), the final required driving force F (2) when the notch filter gain G is set to a value close to 0 is It is not easily influenced by the resonance frequency removal filtering, and tends to be largely calculated. As a result, priority is given to the response regarding the running of the vehicle, and the torsional vibration during acceleration is not effectively suppressed.

  As described above, in the present embodiment, when driving force control is executed so as to suppress torsional vibration during acceleration, torsional vibration suppression is reflected according to the strength of the driver's sport driving preference. I tried to make it. As a result, it achieves the acceleration response required by the driver without giving priority to suppressing torsional vibration during acceleration even when the driver's preference for sports driving is strong, such as seeking a quick response during acceleration. Can do. On the other hand, when the driver's preference for sports driving is weak, priority is given to suppressing torsional vibration during acceleration, and unpleasant vibration can be suppressed.

  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.

It is a control block diagram containing ECU which is a driving force control device of vehicles concerning this embodiment. It is a figure showing the procedure of the required driving force calculation process in ECU. It is a figure which shows the relationship between a sport driving | running | working level and a notch filter gain. It is a flowchart which shows the control structure of the program performed by ECU.

Explanation of symbols

  100 engine, 200 torque converter, 300 automatic transmission, 500 ECU, 600 accelerator pedal opening sensor, 700 sport running switch.

Claims (4)

Driving force setting means for setting the driving force to be generated in the vehicle;
Vibration prediction means for predicting vibration due to generation of the driving force set by the driving force setting means;
Adjusting means for adjusting the set driving force so as to reduce the vibration component predicted by the vibration predicting means;
Detection means for detecting the driving preference of the driver;
Look including a correction means for correcting in accordance with the adjusted driving force to the driving preference,
The adjusting means includes a filtering means for filtering to the set driving force so as to reduce the vibration component predicted by the vibration predicting means ,
The correction means includes a calculation means for multiplying a difference value between the set driving force and the driving force filtered by the filtering means by a gain according to the driving preference, and from the set driving force, A vehicle driving force control device that corrects the adjusted driving force by subtracting the difference value multiplied by the gain by the calculating means . The vehicle driving force control apparatus according to claim 1 , wherein the calculation means includes means for multiplying a gain that decreases as the driver's driving preference is in a power performance-oriented direction. Said detecting means detects the lateral acceleration acting on the vehicle during cornering, wherein sensing the driving preference based on the sensed lateral acceleration, the driving force control of a vehicle according to claim 1 or 2 apparatus. The detection means detects the current position information of the vehicle, it said sensing the driving preference based on the detected current position information, the vehicle driving force control apparatus according to claim 1 or 2.

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