JP2010253978A - Vehicle control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform appropriate vehicle behavior control in correspondence with changes in a vehicle total weight and a gravity center position of the vehicle. <P>SOLUTION: A vehicle control device for performing behavior control of the vehicle 10 at a set target control amount or/and at a target control timing, includes: a weight operation means 1e for estimating or detecting a vehicle total weight; a gravity center position operation means 1d for estimating or detecting a gravity center position of the vehicle; a turning characteristic index setting means 1c for setting a turning characteristic index value representing turning characteristics of the vehicle 10 corresponding to the vehicle total weight and the gravity center position of the vehicle; and a turning controlling means 1b for setting a target control amount or/and a target control timing to keep the vehicle 10 at a desired turning posture based on traveling state quantity representing a traveling state of the vehicle and the turning characteristic index value corresponding to the vehicle total weight and the gravity center position of the vehicle. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vehicle control device that achieves running stability during turning of a vehicle.

  Conventionally, a technique for stabilizing the behavior of a vehicle when turning is known. For example, in Patent Document 1 below, a target turning control amount (target yaw rate) is obtained according to the vehicle speed and the turning angle of the steered wheels, and the target turning control amount (target yaw rate) and the actual turning control amount (actual A technique for performing turn control by setting a target control amount corresponding to a difference from the yaw rate is disclosed. Further, this Patent Document 1 discloses that a target turning control amount (target yaw rate) is calculated based on a stability factor representing turning characteristics, and the stability factor is changed according to the vehicle speed or the like. The point is also described.

  Patent Document 2 below discloses a technique for obtaining a steering force during steering assist control based on the vehicle speed and the weight of the vehicle. Patent Document 3 below discloses a technique in which a center-of-gravity position variable is used for control of a driver assistance system that estimates a center-of-gravity position variable (center-of-gravity position) based on a weight load variable and adjusts the yaw rate of the vehicle. Has been. Patent Document 4 below discloses a technique for adjusting a vehicle lateral acceleration threshold according to the weight of the vehicle and the position of the center of gravity, and performing roll control of the vehicle body using this threshold. Patent Documents 5 and 6 listed below disclose techniques for estimating a side slip angle according to the total weight of the vehicle body and the position of the center of gravity of the vehicle. Patent Document 7 below discloses a technique for estimating the motion state of a vehicle during traction control based on a change in the center of gravity position in the vehicle vertical direction.

JP 2000-95085 A Japanese Patent Laid-Open No. 11-78952 Special table 2008-520981 gazette JP 2006-168441 A JP-A-11-321602 JP-A-11-321603 JP-A-4-237737

  By the way, the total weight of the vehicle (the weight of the vehicle itself + the weight of the occupant, etc.) changes depending on the passenger getting on and off and loading / unloading of luggage. This change in the total vehicle weight also changes the position of the center of gravity of the vehicle and affects the turning characteristics. Therefore, strictly speaking, the turning characteristic index value such as a stability factor representing the turning characteristic shows different values depending on the total weight of the vehicle and the change in the position of the center of gravity of the vehicle. Therefore, if the total vehicle weight or the center of gravity position of the vehicle changes with respect to the design value or the set value, the target turning control amount (target yaw rate) does not become a value that is really required for turning control. Conventionally, changes in the center of gravity of the vehicle are not sufficiently considered, and there is a possibility that appropriate turning control cannot be performed due to a shift in target control values such as target control amount and target control timing.

  SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a vehicle control device that improves the disadvantages of the conventional example and can perform appropriate vehicle behavior control corresponding to changes in the total vehicle weight and the position of the center of gravity of the vehicle. .

  In order to achieve the above object, according to the first aspect of the present invention, in the vehicle control device that controls the behavior of the vehicle at the set target control amount and / or the target control timing, the target control amount according to a change in the total vehicle weight. Alternatively, vehicle control means for changing the target control timing is provided.

  In order to achieve the above object, according to the second aspect of the present invention, in the vehicle control device that controls the behavior of the vehicle at the set target control amount and / or target control timing, the vehicle center of gravity position increases as the total vehicle weight increases. Vehicle control means is provided for determining that the vehicle moves rearward and changing the target control amount or / and the target control timing in accordance with the position of the center of gravity of the vehicle.

  In order to achieve the above object, according to a third aspect of the present invention, in a vehicle control apparatus that controls the behavior of a vehicle at a set target control amount or / and target control timing, the change in the total vehicle weight and the total vehicle weight Vehicle control means is provided for changing the target control amount or / and the target control timing in accordance with a change in the position of the center of gravity of the vehicle accompanying a change in the vehicle.

  For example, as in the invention described in claim 4, in the vehicle control device described in claim 3, weight calculating means for estimating or detecting the total vehicle weight, gravity center position calculating means for estimating or detecting the vehicle center of gravity position, and vehicle Turning characteristic index setting means for setting a turning characteristic index value representing the turning characteristic of the vehicle according to the total vehicle weight and the position of the center of gravity of the vehicle. And about a vehicle control means, the target control amount from which a vehicle will be in a desired turning attitude | position is set based on the driving | running state quantity showing the driving state of a vehicle, and the turning characteristic index value according to a vehicle gross weight and a vehicle gravity center position. It is desirable to configure as follows. As a result, the target control amount corresponding to the change in the vehicle total weight and the vehicle center of gravity position is set, so that the vehicle is controlled by this target control amount, thereby changing the vehicle total weight and the vehicle center of gravity position, And it can be made to turn with the appropriate turning attitude in consideration of the change of equivalent cornering power and yaw moment of inertia accompanying this.

  Further, as in the invention described in claim 5, the vehicle control means takes a desired turning posture based on a running state amount representing a running state of the vehicle and a turning characteristic index value corresponding to the total vehicle weight and the position of the center of gravity of the vehicle. It is desirable to obtain a target turning state amount and set the target control amount according to the difference between the target turning state amount and the actual turning state amount.

  Further, the center-of-gravity position calculating means is configured to estimate that the position of the center of gravity of the vehicle has moved to the rear of the vehicle as the amount of change in the total vehicle weight increases toward the increase side. It is desirable. For example, in a vehicle in a usage pattern in which the loading position of passengers and luggage hardly changes, the total vehicle weight and the position of the center of gravity of the vehicle change according to the amount of the luggage. In a general vehicle, the luggage compartment is located behind the vehicle center of gravity, which serves as a reference as a design value, for example. For this reason, in such a vehicle, it is known that the center of gravity of the vehicle moves to the rear of the vehicle as the total vehicle weight increases. Therefore, by estimating the center of gravity of the vehicle based on the change in the total vehicle weight, It is possible to speed up the arithmetic processing.

  Changes in the total weight of the vehicle and the position of the center of gravity of the vehicle change the equivalent cornering power and the yaw moment of inertia, and thus affect the turning posture during turning. For this reason, the vehicle control device according to the present invention changes the target control amount or / and the target control timing at the time of the turn control according to the change in the total vehicle weight or the position of the vehicle center of gravity. That is, it can be turned with a stable behavior. In addition, if the vehicle gross weight or the vehicle center of gravity changes, the load on the front and rear axles changes, thereby reducing the load on the drive wheels. It becomes difficult to suppress. For this reason, the vehicle control device according to the present invention changes the target control amount or / and the target control timing (target braking force of the drive wheels, etc.) at the time of traction control according to the change in the total vehicle weight or the vehicle center of gravity position. Thus, it is possible to suppress idling of the drive wheels and to start and accelerate the vehicle with stable behavior.

FIG. 1 is a diagram illustrating an example of a vehicle control device according to the present invention and a target vehicle. FIG. 2 is a diagram for explaining the relationship between the load and the cornering power. FIG. 3 is a diagram illustrating the relationship between the total vehicle weight and the yaw moment of inertia. FIG. 4 is a simplified diagram of a linear two-wheel model of a vehicle. FIG. 5 is a flowchart illustrating the setting operation according to the first embodiment. FIG. 6 is a diagram illustrating an example of map data of front and rear centroid positions in the first embodiment. FIG. 7 is a diagram illustrating an example of map data of stability factors in the first embodiment. FIG. 8 is a diagram illustrating an example of map data of a yaw rate response delay coefficient in the first embodiment. FIG. 9 is a diagram illustrating an example of map data of stability factors in the second embodiment. FIG. 10 is a diagram illustrating an example of map data of a yaw rate response delay coefficient in the second embodiment. FIG. 11 is a flowchart illustrating the learning operation according to the second embodiment. FIG. 12 is a diagram illustrating an example of updated stability factor map data according to the second embodiment. FIG. 13 is a diagram illustrating an example of the updated map data of the yaw rate response delay coefficient in the second embodiment.

  Embodiments of a vehicle control device according to the present invention will be described below in detail with reference to the drawings. The present invention is not limited to the embodiments.

[Example 1]
A vehicle control apparatus according to a first embodiment of the present invention will be described with reference to FIGS.

  The vehicle control apparatus according to the first embodiment is prepared as a function of the electronic control unit (ECU) 1 shown in FIG. The electronic control unit 1 includes a CPU (Central Processing Unit) (not shown), a ROM (Read Only Memory) that stores a predetermined control program and the like, and a RAM (Random Access Memory) that temporarily stores the calculation result of the CPU. A backup RAM or the like for storing previously prepared information or the like is used.

The vehicle 10 to which this vehicle control device is applied has a drive wheel (for example, rear wheels W _RL , W _RR ) that outputs (output torque) from a power source such as an engine or a motor (not shown) via a power transmission device such as a transmission. ) As wheel drive force, regardless of whether it is an FR (front engine / rear drive) vehicle, FF (front engine / front drive) vehicle, or four-wheel drive vehicle, and a midship engine or rear engine vehicle A so-called hybrid vehicle having both an engine and a motor as its power source may be used.

This vehicle is provided with a turning device 20 that turns the front wheels W _FL and W _FR as steering wheels. The steering device 20 includes a steering wheel 21 that is a steering operator by a driver, and a turning angle imparting unit 22 that is driven by a steering operation of the steering wheel 21. For example, the turning angle imparting means 22 is based on a so-called rack and pinion mechanism having a rack gear and a pinion gear (not shown).

The vehicle 10 is provided with a braking device 30 that decelerates or stops the vehicle body. The braking device 30 includes a brake pedal 31 that is operated by the driver, and a braking boost that doubles an operation pressure (pedal pressing force) that is input to the brake pedal 31 and that accompanies the driver's brake operation at a predetermined boost ratio. Means (brake booster) 32 and a master for converting the pedal depression force doubled by the brake boosting means 32 into a brake fluid pressure (hereinafter referred to as “master cylinder pressure”) corresponding to the operation amount of the brake pedal 31. Cylinder 33, brake fluid pressure adjusting means (hereinafter referred to as “brake actuator”) 34 for adjusting the master cylinder pressure as it is or for each wheel, and each wheel W _FL to which the brake fluid pressure passed through brake actuator 34 is transmitted , and _{W FR, W RL, W} brake fluid pressure pipe ₃₅ FL of _{RR, 35 FR, 35 RL,} 35 RR, this each Rake liquid pressure pipe _{35 FL, 35 FR, 35 RL} , 35 wheel _W FL brake fluid pressure is supplied each of the respective _RR, W _FR, W _RL, to generate a braking force to the _{W RR} for example, a disk rotor and the caliper or the like Braking force generating means _36FL , _36FR , _36RL , _36RR . The braking device 30 is capable of generating a braking force of an individual magnitude for each of the wheels W _FL , W _FR , W _RL , W _RR , and the wheels W _FL , W _FR , W _RL. , the braking force control for each W _RR braking control means 1a of the electronic control unit 1 is realized by controlling the brake actuator 34.

  The electronic control device 1 performs vehicle control (hereinafter referred to as “vehicle behavior control”) for stabilizing the behavior of the vehicle 10 based on the set target control amount and / or target control values such as target control timing. Control means are provided. In the first embodiment, as the vehicle behavior control, turning control for stabilizing the behavior during turning is exemplified. Therefore, the electronic control device 1 is provided with a turning control means 1b as the vehicle control means.

  The turning control means 1b illustrated here is configured to have a target control value (target value) so that a desired turning posture is obtained according to the difference between the actual turning state quantity (hereinafter referred to as “actual turning state quantity”) and the target turning state quantity. Control amount or / and target control timing) is set, and the vehicle 10 is controlled with the target control value to stabilize the turning posture. The target turning state amount is a turning state amount when the vehicle 10 is in a desired turning posture. Here, the actual yaw rate (hereinafter referred to as “actual yaw rate”) γr as the actual turning state quantity is detected by the yaw rate sensor 41, and the target yaw rate γt as the target turning state quantity is based on the traveling state of the vehicle 10. The actual yaw rate γr is compared with the target yaw rate γt.

The target yaw rate γt is determined by the specifications of the vehicle 10 (wheel base L), the travel state amount representing the travel state of the vehicle 10 (the vehicle speed V, the steering angle θst of the front wheels W _FL and W _{FR as} the steering wheels, the vehicle lateral acceleration). Gy) and a turning characteristic index value (stability factor KH, yaw rate response delay coefficient TP) representing the turning characteristic of the vehicle 10 are substituted into, for example, the following Equation 1 and calculated. “S” in Equation 1 is a Laplace operator.

The information of the wheel base L is a numerical value unique to the vehicle and is stored in advance in the ROM or the like of the electronic control device 1. Further, the vehicle speed V information is detected by the vehicle speed detecting means. As this vehicle speed detection means, for example, a vehicle speed sensor 42 that detects the vehicle speed itself, or a wheel speed sensor 43 _FL , 43 _FR , 43 _RL , that detects the wheel speed of each wheel W _FL , W _FR , W _RL , W _RR , 43 _RR can be used. The turning angle θst is detected by, for example, a turning angle sensor 44 provided in the turning angle providing means 22. The vehicle lateral acceleration Gy is detected by a vehicle lateral acceleration sensor 45 that detects vehicle lateral acceleration.

The stability factor KH includes the total vehicle weight M, the wheel base L (design value), the distance Lf from the front axis to the center of gravity, the distance Lr from the rear axis to the center of gravity, the equivalent cornering power Cpf of the front wheels FL and FR, and rear wheel _{W RL,} by an equivalent cornering power Cpr of _{W RR} illustrates a turning characteristic of the vehicle 10. On the other hand, the yaw rate response delay coefficient Tp, and that the coefficient of the vehicle speed V of the first-order system having a time constant that depends on the vehicle speed V, the wheel base L (design value), the equivalent of the front wheels W _FL, W _FR cornering power Cpf, the rear wheels _{W RL,} the equivalent cornering power Cpr and the yaw inertia moment Iz of _{W RR} illustrates a turning characteristic of the vehicle 10. In general, the stability factor KH and the yaw rate response delay coefficient TP can be calculated using the following formulas 2 and 3 in which the model of the vehicle 10 is a linear two-wheel model.

  Here, conventionally, the position of the center of gravity of the vehicle 10 is unchanged. For this reason, the distance Lf from the front axis to the center of gravity and the distance Lr from the rear axis to the center of gravity are prepared in advance as design values.

Conventionally, the total vehicle weight M is also considered to be unchanged, and thus is prepared as a design value. For this reason, the equivalent cornering power Cpf of each of the front wheels W _FL , W _FR and the rear wheels W _RL , W _RR is provided. , Cpr information and yaw inertia moment Iz information are prepared as vehicle-specific constant values.

  The turning control means 1b obtains the target yaw rate γt based on the specifications of the vehicle 10, the running state quantity, etc., and compares it with the detected actual yaw rate γr. Then, if the actual yaw rate γr is larger than the target yaw rate γt, the turning control means 1b reduces the output of the power source and generates a braking force on the turning outer wheel on the front side of the vehicle, and the actual yaw rate γr uses the target yaw rate γr. If it is smaller than γt, the output of the power source is reduced and braking force is generated on the turning inner wheel on the rear side of the vehicle. For the wheel to be controlled, a larger braking force is generated as the difference between the actual yaw rate γr and the target yaw rate γt increases. Thereby, this turning control means 1b controls the turning posture of the vehicle 10 in a stable direction.

By the way, the total vehicle weight M is the sum of the vehicle weight M1 that is the weight of the vehicle 10 itself and the total weight M2 of the passengers and the luggage that are the total of the passengers on the vehicle 10 and the loaded luggage. Therefore, the variable varies depending on the total weight M2 of the occupant and the load. The seating position of the occupant and the loading position of the baggage are separated in the front-rear and left-right directions of the vehicle 10 with respect to the center of gravity position of the vehicle 10 as a design value (hereinafter referred to as “designed vehicle center of gravity position”) P0. For this reason, when the total vehicle weight M changes due to passengers getting on and off, loading and unloading, etc., the vehicle center of gravity position P deviates from the designed vehicle center of gravity position P0. Therefore, strictly speaking, the distance Lf from the front axis to the center of gravity and the distance Lr from the rear axis to the center of gravity obtained based on the design vehicle center of gravity position P0 in the longitudinal direction of the vehicle in the linear two-wheel model are as described above. Don't be. Further, the cornering power is, strictly seen, as shown in FIG. 2, the front wheels _{W FL,} load acting on the shaft before if _{W FR} (hereinafter. Referred to as "front axle weight") Mf, the rear wheels _{W RL,} In the case of _WRR , it is a value that changes according to the load acting on the rear shaft (hereinafter referred to as “rear shaft weight”) Mr. It is known that the front axle weight Mf and the rear axle weight Mr change with changes in the vehicle gross weight M and the vehicle gravity center position P. Accordingly, the equivalent cornering powers Cpf and Cpr of the front wheels W _FL and W _FR and the rear wheels W _RL and W _RR change with changes in the vehicle total weight M and the vehicle center of gravity position P, and thus do not follow the design values. Strictly, the yaw moment of inertia Iz is a value that changes according to the total vehicle weight M, as shown in FIG. 3, and increases as the total vehicle weight M increases.

  From this, it can be said that the actual stability factor KH and the yaw rate response delay coefficient TP change according to the change of the total vehicle weight M with respect to the design value and the change of the vehicle gravity center position P accompanying this change. That is, the conventionally used stability factor KH and yaw rate response delay coefficient TP are deviated from the actual values by the change in the vehicle total weight M and the vehicle center of gravity position P. For this reason, the target yaw rate γt is also deviated from the original value by the change amount unless the vehicle total weight M and the vehicle gravity center position P (= P0) are as designed. Since the deviation from the actual value of the target yaw rate γt appears in the difference from the actual yaw rate γr, the larger the deviation amount (that is, the greater the change in the total vehicle weight M and the vehicle gravity center position P), the more the turning control is performed. The braking force generated for the wheels to be controlled is removed from the originally required magnitude. Accordingly, the vehicle 10 is less likely to be controlled to a desired turning posture as the actual total vehicle weight M and the vehicle center-of-gravity position P deviate from the design values. Therefore, in the electronic control device 1 of the first embodiment, the turning characteristic for setting the stability factor KH and the yaw rate response delay coefficient TP in consideration of the change in the total vehicle weight M and the change in the vehicle center of gravity position P accompanying this change. An index setting means 1c is provided.

  FIG. 4 shows a simplified diagram of a linear two-wheel model of the vehicle 10 according to the actual situation.

  In this figure, “Lf1” is the distance from the front axle to the action point m1 where the vehicle weight M1 acts as a load, and “Lf2” is the distance from the front axle to the action point m2 where the total weight M2 of the occupant and luggage acts as a load. Represents.

  The action point m1 corresponds to the position of the center of gravity of the vehicle 10 itself with no occupant or luggage (the center of gravity position of the design value in the linear two-wheel model). Therefore, the distance Lf1 from the front axis to the action point m1 can be prepared as a design value.

  Next, the action point m2 is determined by the seating position of the occupant and the loading position of the luggage. Here, the seating position of the occupant and the loading position of the luggage are determined in advance in any vehicle 10. For this reason, it is possible to approximately determine in advance in which position of the vehicle 10 the occupant or the baggage acts as a load. Therefore, the approximated position may be set as the action point m2. That is, the distance Lf2 from the front axis to the action point m2 can be prepared as a design value. This approach based on the approximation is particularly useful in a vehicle 10 in which each seating position is close to the design vehicle center-of-gravity position P0 and is not a large luggage room in front, rear, left, and right, for example, a sedan type or a coupe type vehicle 10.

  On the other hand, in the vehicle 10 such as a bus having a large number of passengers, the action point m2 varies greatly depending on the number of passengers, the seating position and the standing position of the passengers. In addition, in the vehicle 10 such as a truck having a wide cargo space at least in the front-rear or left-right direction, the action point m2 varies greatly depending on the amount of luggage and the loading position. Therefore, in such a vehicle 10, it is difficult to determine the point of action m2 in one place, so the turning characteristic index setting means 1c may be configured so that the point of action m2 is obtained. For example, the turning characteristic index setting means 1c can calculate the action point m2 based on a detection signal using a pressurization state detection means such as a piezoelectric element that can detect the presence or absence of pressurization. In the vehicle 10 such as a bus, the pressurization state detection means may be disposed in each seat and a plurality of the pressure state detection means may be disposed on the floor at substantially equal intervals so that the seating position and standing position of the occupant can be grasped. In the vehicle 10 such as a truck, a plurality of pressurization state detecting means may be arranged on the floor of the cargo room at substantially equal intervals so that the loading position of the luggage can be grasped. This pressurization state detecting means is provided in both the seat and the cargo room, and further provided on the floor where the occupant such as a bus stands, so that the operation point m2 is calculated accurately. May be increased. Further, the turning characteristic index setting means 1c can use a load detection means such as a load meter for detecting a load. The location of the load detecting means may be the same as that of the pressurized state detecting means. The load detecting means can grasp not only the seating position and standing position of the occupant and the loading position of the luggage, but also the weight of the occupant and the luggage. For this reason, the load detecting means is provided in both the seat and the cargo compartment, and further provided on the floor where the occupant such as a bus can stand, and is also provided on the floor where the standing position is located, and the operation point m2 is calculated. While increasing the accuracy, the total weight M2 of the occupant and the luggage may be detected.

  On the other hand, even in the case of the vehicle 10 such as the bus, the operating point m2 does not vary greatly in the case of a vehicle in which the number of passengers and the occupant's arrangement are substantially constant or a driving condition in which these are substantially constant. . Further, even if the vehicle 10 is a truck or the like, the operating point m2 is also applied to the vehicle 10 in which the number of passengers, the arrangement of passengers, the type of baggage and the loading position are substantially constant, or the driving conditions in which these are substantially constant. Does not fluctuate significantly. Therefore, in such cases, it is possible to prepare a distance Lf2 from the front axis to the action point m2 as a design value. In particular, when each occupant is the same person or even when the seating position of each occupant is constant, the action point m2 hardly fluctuates, so that information on the distance Lf2 as a more accurate design value can be obtained. . Therefore, in such cases, it is only necessary to prepare information on the distance Lf2 as a design value.

“Lf _ZAN ” in FIG. 4 represents the distance from the front axis to the current vehicle center of gravity position P based on the total vehicle weight M, and the center of gravity position in the vehicle front-rear direction in the linear two-wheel model (hereinafter, “front-rear center of gravity position”). It can be said.) The front / rear center-of-gravity position Lf _ZAN is obtained by the center-of-gravity position calculation means 1d of the electronic control unit 1 using the following equation (4).

When calculating the front-rear center-of-gravity position Lf _ZAN , information on the vehicle weight M1, the total weight M2 of passengers and luggage, the distance Lf1 from the front axis to the action point m1, and the distance Lf2 from the front axis to the action point m2 is necessary. become. For the respective distances Lf1 and Lf2, the set values and the calculated values described above are used. Moreover, since the design value can utilize the vehicle weight M1, this is used. On the other hand, the total weight M2 of the occupant and the baggage may be obtained by using the detected value as long as the minimum number of load detecting means is mounted as described above. If not, it needs to be obtained by another method. In the first embodiment, the electronic control device 1 is provided with a weight calculation means 1e, which is used.

  When a sufficient number of load detection means are mounted, the weight calculation means 1e can calculate the total weight M2 of the occupant and the baggage using the detection signal of each load detection means. In this case, the total vehicle weight M is obtained by adding the total weight M2 of the passengers and luggage and the vehicle weight M1. Further, instead of such a plurality of load detection means, a weight detection means capable of detecting the total vehicle weight M may be used. As this weight detection means, for example, a device that is disposed on a suspension or the like and detects the total vehicle weight M in a static state is known.

  On the other hand, when the load detecting means is not sufficiently mounted, the weight calculating means 1e first estimates the total vehicle weight M by a well-known method in this technical field. In this case, the weight calculating means 1e can estimate the total vehicle weight M by using information such as engine output torque or vehicle driving force, vehicle acceleration or vehicle deceleration, vehicle speed, and the like. For example, the weight calculation means 1e is configured so that the magnitude of vehicle acceleration or vehicle deceleration with respect to the accelerator opening (or throttle opening) in a state where an output torque (or vehicle driving force) of an engine of a certain magnitude is generated. Accordingly, the total vehicle weight M is estimated. At that time, the total vehicle weight M increases as the vehicle acceleration relative to the accelerator opening (or throttle opening) decreases, and increases as the vehicle deceleration relative to the accelerator opening (or throttle opening) increases. Then, the weight calculating means 1e subtracts the vehicle weight M1, which is a design value, from the estimated total vehicle weight M to estimate the total weight M2 of the occupant and the luggage (M2 = M−M1). The engine output torque may be calculated based on the engine speed or the like, or a command value from the electronic control unit 1 to the engine may be used. The vehicle acceleration or vehicle deceleration may be detected using a detection signal from the vehicle longitudinal acceleration sensor. The vehicle speed may be detected using a detection signal from a vehicle speed sensor or a wheel speed sensor.

  The stability factor KH considering the change in the total vehicle weight M (in other words, the change in the total weight M2 of the occupant and the baggage) and the change in the vehicle center-of-gravity position P is calculated using the following equation 5 based on the above equation 2. To do.

In Equation 5, parameters other than the vehicle weight M1 and the wheel base L are all variables that change according to changes in the vehicle total weight M and the vehicle gravity center position P. Information on the total weight M2 of the occupant and the baggage and the front-rear center of gravity position Lf _ZAN can be obtained as described above. Further, the equivalent cornering powers Cpf and Cpr of the front wheels W _FL and W _FR and the rear wheels W _RL and W _RR can be approximated by, for example, a quadratic expression of the load based on FIG. The following formulas 6 and 7 will be used respectively.

  In these expressions 6 and 7, “af”, “ar”, “bf”, “br”, “cf”, and “cr” are constants. Note that “af ≠ 0” and “ar ≠ 0”. Further, the front axle weight Mf and the rear axle weight Mr in these formulas 6 and 7 can be obtained by the following formulas 8 and 9, respectively.

Further, the yaw rate response delay coefficient TP considering the change in the total vehicle weight M (change in the total weight M2 of the occupant and the baggage) and the change in the vehicle gravity center position P is calculated using the above equation 3. The yaw moment of inertia Iz in the equation 3 changes according to the total vehicle weight M as described above. In FIG. 3, the vehicle total weight M and the yaw inertia moment Iz are illustrated as being in a relationship as shown in the following Expression 10. In Expression 10, “k” is a proportional coefficient, and “Io” is an offset. Further, the equivalent cornering powers Cpf, Cpr of the front wheels W _FL , W _FR and the rear wheels W _RL , W _{RR in} the equation 3 change as the vehicle center-of-gravity position P changes.

Hereinafter, the setting operation of the stability factor KH, the front / rear center-of-gravity position Lf _ZAN, and the yaw rate response delay coefficient TP in the vehicle control apparatus of the first embodiment will be described based on the flowchart of FIG.

When the turning characteristic index setting means 1c of the electronic control device 1 receives the ignition ON signal (step ST1), the turning characteristic index setting means 1c initializes the stability factor KH, the longitudinal center of gravity position Lf _ZAN, and the yaw rate response delay coefficient TP (step ST1). ST2, ST3, ST4). At this time, the turning characteristic index setting means 1c reads the information of the stability factor KH, the front / rear center of gravity position Lf _ZAN and the yaw rate response delay coefficient TP stored last time, that is, the last, from the storage means of the electronic control unit 1, and Set as initial value.

Thereafter, the subsequent arithmetic processing is repeated until the set stop condition is satisfied. The setting stop condition is a condition for stopping the setting operation of the turning characteristic index values (stability factor KH and yaw rate response delay coefficient TP) and the longitudinal center of gravity position Lf _ZAN shown below. For example, the turning characteristic index setting means 1c determines that the vehicle 10 is not a temporary stop but a continuous stop such as parking when a predetermined time has elapsed after the ignition is turned off, It is determined that the setting stop condition is satisfied.

  First, the turning characteristic index setting means 1c acquires information on the current total vehicle weight M, and also acquires information on the reliability (hereinafter referred to as “weight reliability”) trm (step ST5). .

  The total vehicle weight M is estimated or detected by the weight calculation means 1e as described above. In addition, the weight reliability trm is set higher as, for example, the detection of the total weight M2 of the occupant and the load or the estimation of the total weight M of the vehicle is performed when the vehicle acceleration or the vehicle deceleration is large. The weight calculating means 1e sets “0” when the reliability is lowest and “1” when the reliability is highest, and obtains and sets the weight reliability trm (0 ≦ trm ≦ 1) within a range of 0 to 1. . The weight calculation means 1e executes the calculation of the total vehicle weight M and the weight reliability trm at all times or every predetermined time, and stores them in the storage means of the electronic control unit 1, for example. The turning characteristic index setting means 1c reads the total vehicle weight M and the weight reliability trm from the storage means, and sets them as the current total vehicle weight M and the weight reliability trm.

Subsequently, the turning characteristic index setting means 1c determines whether or not it is possible to set the turning characteristic index value (stability factor KH and yaw rate response delay coefficient TP) and the longitudinal center of gravity position Lf _ZAN (step ST6).

When obtaining these, information on the total vehicle weight M (= M1 + M2) is required. Therefore, even if the turning characteristic index value (stability factor KH and yaw rate response delay coefficient TP) and the front-rear center-of-gravity position Lf _ZAN are obtained when the weight reliability trm for the total vehicle weight M is low, the present accurate values are obtained. Since it is not shown, it should not replace what is currently set. For this reason, the turning characteristic index setting unit 1c determines that these settings can be made when the obtained weight reliability trm is high. Here, the weight reliability trm is compared with a predetermined threshold tr1 (0 <tr1 <1), and if the weight reliability trm is larger than the threshold tr1, it is determined that the setting is possible. The threshold value tr1 is, for example, an experiment for comparing the calculated value of the vehicle total weight M and the actually measured value for each weight reliability trm, and an error between the calculated value and the actually measured value can be allowed from the viewpoint of information reliability. The weight reliability trm when there is no upper limit is set.

The turning characteristic index setting means 1c has the weight reliability trm for the total vehicle weight M equal to or less than the threshold value tr1, and replaces the turning characteristic index value (stability factor KH and yaw rate response delay coefficient TP) with the front / rear center of gravity position Lf _ZAN . If it is determined that it should not be set (that is, it is determined that setting is impossible), the process returns to step ST5 to newly acquire information on the total vehicle weight M and the weight reliability trm.

On the other hand, the turning characteristic index setting unit 1c is larger than its weight confidence trm threshold tr1, turning characteristic exponent value (stability factor KH and the yaw rate response delay coefficient TP) can be set around the center of gravity position Lf _ZAN If it is determined that there is, the center-of-gravity position calculating means 1d is caused to determine the front-rear center-of-gravity position Lf _ZAN of the current vehicle from Equation 4 based on the acquired current total vehicle weight M (step ST7).

In step ST7, first, parameters other than the vehicle weight M1 prepared as design values and the distance Lf1 from the front shaft to the action point m1 are obtained. The center-of-gravity position calculating means 1d subtracts the vehicle weight M1 from the total vehicle weight M acquired in step ST5, and obtains the current total weight M2 of the occupant and the load (M2 = M−M1). As described above, if the total weight M2 of the passenger and the baggage can be directly detected, the detection result may be used. The center-of-gravity position calculating means 1d calculates a distance Lf2 from the front axis to the action point m2. As for the distance Lf2, as described above, if an approximate value can be prepared as a design value, the prepared set value is used. If the accuracy is improved, the detection signal of the pressurization state detecting means or the load detecting means is used. Calculate based on In step ST7, these various parameters are substituted into the above equation 4 to obtain the front-rear center-of-gravity position Lf _ZAN corresponding to the current total vehicle weight M.

Next, the turning characteristic index setting means 1c calculates the stability factor KH according to the current total vehicle weight M and the vehicle center of gravity position P using the information of the front and rear center of gravity position Lf _ZAN (step ST8). ).

In this step ST8, the equivalent cornering powers Cpf and Cpr of the front wheels W _FL and W _FR and the rear wheels W _RL and W _RR which have not been obtained in the process so far are obtained using the above equations 6 to 9. Thus, various necessary parameters are obtained, and the turning characteristic index setting means 1c substitutes these into the above equation 5 to obtain the stability factor KH corresponding to the current total vehicle weight M.

  Further, the turning characteristic index setting means 1c obtains a yaw rate response delay coefficient TP corresponding to the current total vehicle weight M and the vehicle center of gravity position P (step ST9).

  In this step ST9, the yaw inertia moment Iz corresponding to the current total vehicle weight M that has not been obtained in the process so far is obtained from the above equation 10. Since various necessary parameters are obtained in this way, the turning characteristic index setting means 1c substitutes these into Equation 3 to obtain the yaw rate response delay coefficient TP corresponding to the current total vehicle weight M and the vehicle center of gravity position P.

After obtaining the turning characteristic index value (stability factor KH and yaw rate response delay coefficient TP) and the front / rear center of gravity position Lf _ZAN in this way, the turning characteristic index setting means 1c uses the calculated values for the current total vehicle weight. The turning characteristic index value (stability factor KH and yaw rate response delay coefficient TP) corresponding to M and the vehicle center of gravity position P and the front-rear center of gravity position Lf _ZAN are set (step ST10). These set values are stored in the storage means of the electronic control device 1.

  The vehicle control device executes vehicle control using a stability factor KH and a yaw rate response delay coefficient TP set in consideration of changes in the total vehicle weight M and the vehicle gravity center position P. In other words, the turning control means 1b determines the turning characteristic index values (stability factor KH and yaw rate response delay coefficient TP) corresponding to the current total vehicle weight M and the vehicle center of gravity position P, and a running state quantity ( The target yaw rate γt is obtained by substituting the detected vehicle speed V and the like into the above equation 1, and compared with the actual yaw rate γr. Then, the turning control means 1b sets a target control amount (that is, a target braking force of the wheel to be controlled) or / and a target control timing according to the difference between the target yaw rate γt and the actual yaw rate γr, and the brake actuator 34 Is controlled at the target control timing to generate a target braking force on the wheel. The target control amount and the target control timing take into account the current total vehicle weight M and the vehicle center of gravity position P, which have changed due to passengers getting on and off, loading and unloading, etc. Therefore, the vehicle control device can turn the vehicle 10 in a desired turning posture according to the current total vehicle weight M and the vehicle center-of-gravity position P.

By the way, in the above-described example, the front-rear center-of-gravity position Lf _ZAN , the stability factor KH, and the yaw rate response delay coefficient TP are calculated in steps ST7 to ST9. It is set as a value. Here, when the number of occupants, the seating position, the weight of the luggage, and the loading position are variously changed, the total vehicle weight M and the vehicle center-of-gravity position P change variously according to the changes. For this reason, by performing the above-described setting operation in which the number of occupants is variously changed or a similar simulation, conditions such as various occupant numbers (that is, various vehicle total weight M and vehicle center-of-gravity position P are set). The values of the turning characteristic index values (stability factor KH and yaw rate response delay coefficient TP) and the front-rear center-of-gravity position Lf _{ZAN according to} the conditions can be obtained. By collecting these, map data of the front-rear center-of-gravity position Lf _ZAN , the stability factor KH, and the yaw rate response delay coefficient TP shown in FIGS. Accordingly, in the above step ST7～ST9, the map data available to longitudinal center-of-gravity position _{Lf ZAN,} and may be derive information stability factor KH and the yaw rate response delay coefficient TP. The map data is stored in the storage means of the electronic control device 1, for example.

The map data of FIG. 6 is for obtaining information on the front / rear center-of-gravity position Lf _ZAN corresponding to the total vehicle weight M. For this longitudinal center of gravity position Lf _ZAN , the stability factor KH and the yaw rate response delay coefficient TP have different values if the vehicle center of gravity position P is different even with the same total vehicle weight M. For this reason, the map data in FIGS. 7 and 8 are configured to obtain information on the stability factor KH and the yaw rate response delay coefficient TP corresponding to the total vehicle weight M, respectively. Specifically, it is prepared for each front and rear center of gravity position Lf _ZAN ) or for each range enclosed in the vicinity including the vehicle center of gravity position P.

The map data of FIGS. 6 to 8 may be updated in accordance with the calculation results of steps ST7 to ST9. In this case, the turning characteristic index setting means 1c is provided with a learning function for setting results of the turning characteristic index values (stability factor KH and yaw rate response delay coefficient TP) and the front-rear center-of-gravity position Lf _ZAN . The learning function of the front / rear center-of-gravity position Lf _ZAN may be provided in the center-of-gravity position calculation means 1d.

Further, in the above-described example, the front-rear center-of-gravity position Lf _ZAN , that is, the current vehicle center-of-gravity position P is obtained from Equation 4 above. Here, in the case of a general vehicle 10, whether it is a sedan type or a truck or the like, the luggage compartment is located behind the designed vehicle center of gravity position P0. Therefore, the vehicle center of gravity position P moves toward the rear of the vehicle with respect to the designed vehicle center of gravity position P0 as the amount of cargo increases, in other words, as the amount of change in the vehicle gross weight M increases. Depending on how the vehicle 10 is used, there is a case where a load is loaded at substantially the same place in the cargo compartment. In this case, a correlation is created between the amount of change in the total vehicle weight M and the amount of movement of the vehicle center of gravity position P. Therefore, in the vehicle 10 adopting such a usage pattern, it is estimated that the vehicle center of gravity position P has moved to the rear of the vehicle as the amount of change in the vehicle total weight M increases, and the correlation is obtained. Based on this, the center-of-gravity position calculation means 1d may be configured to estimate the current vehicle center-of-gravity position P (= front-rear center-of-gravity position Lf _ZAN ). In the vehicle 10, if information on the current total vehicle weight M is obtained, the current vehicle gravity center position P is estimated, and then the stability factor KH and the yaw rate response delay coefficient are calculated using the above formulas 5 and 3. TP can be obtained, and the target yaw rate γt can be obtained from Equation 1 above. For this reason, in this vehicle 10, it is possible to speed up the arithmetic processing when obtaining the target yaw rate γt. Further, in this vehicle 10, the turning characteristic index value setting means obtains the stability factor KH and the yaw rate response delay coefficient TP based on the total vehicle weight M, and further the turn control based on the total vehicle weight M. The means 1b obtains the target yaw rate γt.

[Example 2]
Next, a second embodiment of the vehicle control device according to the present invention will be described with reference to FIGS.

  The vehicle control device of the second embodiment is prepared as one function of the electronic control device 1 like the vehicle control device of the first embodiment described above, and the turning control means 1b, the weight calculation means 1e, the turning characteristic index setting and the like. Means 1c and the like are provided. In addition, this vehicle control device is illustrated as being applied to the vehicle 10 exemplified in the first embodiment.

  The turning characteristic index setting means 1c according to the first embodiment calculates the stability factor KH using the information on the total vehicle weight M and the vehicle center of gravity position P when the weight reliability trm is high and the above-described equation 5, and the vehicle The yaw rate response delay coefficient TP was calculated using information on the total weight M and the vehicle gravity center position P and Equation 3. Further, the turning characteristic index setting means 1c of the first embodiment obtains the stability factor KH and the yaw rate response delay coefficient TP using the information of the vehicle total weight M and the vehicle gravity center position P and the map data.

  On the other hand, the turning characteristic index setting means 1c according to the second embodiment may obtain information on the stability factor KH and the yaw rate response delay coefficient TP in the same manner as the first embodiment. Configure as follows. For example, estimation of the stability factor KH and estimation of the yaw rate response delay coefficient TP may be performed using a well-known method in this technical field. An example of the estimation method is described in a patent document (Japanese Patent Laid-Open No. 2004-26073), and this may be used.

  Further, the turning characteristic index setting means 1c according to the second embodiment uses the reliability of information on the estimated stability factor (hereinafter referred to as “estimated stability factor”) KHp (hereinafter referred to as “estimated stability factor reliability”). ) Trkh and the estimated yaw rate response delay coefficient (hereinafter referred to as “estimated yaw rate response delay coefficient”) TPp reliability (hereinafter referred to as “estimated yaw rate response delay coefficient reliability”) trtp. It is also configured to ask for. The estimated stability factor reliability trkh is increased as the estimated stability factor KHp is estimated when the vehicle lateral acceleration Gy is large. Similarly, the estimated yaw rate response delay coefficient reliability trtp is increased as the estimated yaw rate response delay coefficient TPp is estimated when the vehicle lateral acceleration Gy is large. The turning characteristic index setting means 1c sets “0” when the reliability is the lowest and “1” when the reliability is the highest, and the estimated stability factor reliability trkh (0 ≦ trkh ≦ 1) within a range of 0 to 1. And the estimated yaw rate response delay coefficient reliability trtp (0 ≦ trtp ≦ 1), respectively.

Further, the turning characteristic index setting means 1c of the second embodiment has a turning characteristic index value (stability factor) if the weight reliability trm, the estimated stability factor reliability trkh, and the estimated yaw rate response delay coefficient reliability trtp are high. KH and yaw rate response delay coefficient TP) are updated (ie, learned) based on the respective estimated values. For example, map data of the stability factor KH and the yaw rate response delay coefficient TP are prepared in the storage means of the electronic control apparatus 1 of the second embodiment. The map data of the stability factor KH is configured to obtain information on the stability factor KH according to the total vehicle weight M, as shown in FIG. 9, for example, and a predetermined vehicle center of gravity position P (front / rear center of gravity position Lf) _ZAN ) or for each range enclosed in the vicinity including the vehicle center of gravity position P. In the map data of FIG. 9, the stability factor KH for each range (A to H) of the total vehicle weight M divided by a predetermined weight is registered. Similarly, the map data of the yaw rate response delay coefficient TP is configured to obtain information of the yaw rate response delay coefficient TP according to the total vehicle weight M as shown in FIG. Prepared for each (front-rear center-of-gravity position Lf _ZAN ) or for each range enclosed in the vicinity including the vehicle gravity center position P In the map data of FIG. 10, the yaw rate response delay coefficient TP for each range (A to H) of the total vehicle weight M divided by a predetermined weight is registered. The turning characteristic index setting means 1c of the second embodiment updates each map data based on the estimated stability factor KHp and the estimated yaw rate response delay coefficient TPp.

  Hereinafter, the learning operation of the stability factor KH and the yaw rate response delay coefficient TP in the vehicle control apparatus of the second embodiment will be described based on the flowchart of FIG.

  Also in the second embodiment, the turning characteristic index setting means 1c initializes the stability factor KH and the yaw rate response delay coefficient TP when receiving the ignition ON signal (step ST11) (steps ST12 and ST13). . In steps ST12 and ST13, for example, the information of the stability factor KH and the yaw rate response delay coefficient TP set by the turning control means 1b at the time of calculating the target yaw rate γt last time is read from the storage means of the electronic control device 1. These are respectively set as initial values.

  Thereafter, the subsequent arithmetic processing is repeated until the learning stop condition is satisfied. The learning stop condition is a condition for stopping the learning operation of the turning characteristic index values (stability factor KH and yaw rate response delay coefficient TP) shown below. For example, the turning characteristic index setting means 1c determines that the vehicle 10 is not a temporary stop but a continuous stop such as parking when a predetermined time t1 has elapsed after the ignition is turned off. Then, it is determined that the learning stop condition is satisfied. The predetermined time t1 is set longer than the predetermined time t2 used in step ST25 described later (t1> t2).

  First, the turning characteristic index setting unit 1c acquires information on the current total vehicle weight M and information on the weight reliability trm, similarly to the first embodiment (step ST14).

  Further, the turning characteristic index setting means 1c estimates the stability factor KH (step ST15), and obtains information on the estimated stability factor reliability trkh for the information on the estimated stability factor KHp (step ST16).

  The turning characteristic index setting means 1c estimates the yaw rate response delay coefficient TP (step ST17), and obtains information on the estimated yaw rate response delay coefficient reliability trtp for the information on the estimated yaw rate response delay coefficient TPp (step ST18). ).

  The turning characteristic index setting means 1c includes information on the current total vehicle weight M, the estimated stability factor KHp and the estimated yaw rate response delay coefficient TPp, and their reliability (weight reliability trm, estimated stability factor reliability trkh and After obtaining information on the estimated yaw rate response delay coefficient reliability trtp), the weight reliability trm is determined (step ST19).

  As described in the first embodiment, the turning characteristic index values (stability factor KH and yaw rate response delay coefficient TP) when the weight reliability trm is low do not indicate accurate values at the present time, and thus are currently set. Should not be replaced with Therefore, if it is determined in step ST19 that the weight reliability trm is low, the process returns to step ST14 so that the estimated stability factor KHp and the estimated yaw rate response delay coefficient TPp are not updated as the learning result, and the new vehicle total Information on the weight M and information on the weight reliability trm are acquired. In this step ST19, the weight reliability trm is compared with a predetermined threshold tr2 (0 <tr2 <1), and if the weight reliability trm is larger than the threshold tr2, it is determined that the weight reliability trm is high. If the weight reliability trm is equal to or less than the threshold value tr2, it is determined that the weight reliability trm is low. The threshold value tr2 may be set in the same manner as the threshold value tr1 of the first embodiment.

  When it is determined in step ST19 that the weight reliability trm is high, the turning characteristic index setting unit 1c determines the estimated yaw rate response delay coefficient reliability trtp (step ST20).

  For example, here, the estimated yaw rate response delay coefficient reliability trtp is compared with a predetermined threshold tr3 (0 <tr3 <1), and if the estimated yaw rate response delay coefficient reliability trtp is larger than the threshold tr3, the estimated yaw rate If it is determined that the response delay coefficient reliability trtp is high and the estimated yaw rate response delay coefficient reliability trtp is equal to or less than the threshold tr3, it is determined that the estimated yaw rate response delay coefficient reliability trtp is low. The threshold tr3 is an experiment in which the estimated yaw rate response delay coefficient TPp is compared with the yaw rate response delay coefficient TP obtained by, for example, the arithmetic expression of the above-described equation 3 for each estimated yaw rate response delay coefficient reliability trtp. The estimated yaw rate response delay coefficient reliability trtp is set for an upper limit that is unacceptable from the viewpoint of information reliability.

When the turning characteristic index setting unit 1c determines that the estimated yaw rate response delay coefficient reliability trtp is low in step ST20, the turning characteristic index setting unit 1c uses the existing learning result stored in the storage unit of the electronic control device 1 to delay the yaw rate response. The coefficient TP is initialized again based on the current total vehicle weight M and the vehicle center of gravity position P (step ST21). Therefore, after obtaining information such as the total vehicle weight M, the turning characteristic index setting unit 1c causes the center-of-gravity position calculation unit 1d to calculate the front-rear center-of-gravity position Lf _{ZAN according to} the above equation 4, and the current vehicle center-of-gravity position P To clarify.

  The learning result is the map data shown in FIG. Therefore, in this step ST21, the current vehicle gross weight M and the vehicle gravity center position P are compared with the map data, and the yaw rate response delay coefficient TP read as corresponding to the vehicle gross weight M and the vehicle gravity center position P is obtained. Set the initial value again. The initial value here can be said to be a value in line with the current state because the current total vehicle weight M and the vehicle center-of-gravity position P are considered in comparison with the initial value in step ST13.

  The turning characteristic index setting means 1c sets the yaw rate response delay coefficient TP in step ST21, returns to step ST17, and again estimates the yaw rate response delay coefficient TP. In this case, since it is known that the weight reliability trm is determined to be high when the process proceeds to step ST19, the determination of step ST19 may be omitted and the process may proceed to step ST20. Here, since the information on the total vehicle weight M when the weight reliability trm is high is always highly accurate, the process returns to step ST17. However, the total vehicle weight M, the vehicle center of gravity position P, and the yaw rate response delay coefficient TP are returned. If the above relationship is obtained with higher accuracy, the process may return to step ST14 to acquire information such as the total vehicle weight M.

  When it is determined that the estimated yaw rate response delay coefficient reliability trtp is high in step ST20, the turning characteristic index setting unit 1c determines the estimated stability factor reliability trkh (step ST22).

  For example, here, when the estimated stability factor reliability trkh is compared with a predetermined threshold tr4 (0 <tr4 <1) and the estimated stability factor reliability trkh is greater than the threshold tr4, the estimated stability factor If it is determined that the reliability trkh is high and the estimated stability factor reliability trkh is equal to or less than the threshold tr4, it is determined that the estimated stability factor reliability trkh is low. As the threshold tr4, an experiment is performed to compare the estimated stability factor KHp with the stability factor KH obtained by, for example, the arithmetic expression of Equation 5 described above for each estimated stability factor reliability trkh. Is set to the estimated stability factor reliability trkh when the upper limit is unacceptable from the viewpoint of safety.

  When the turning characteristic index setting unit 1c determines that the estimated stability factor reliability trkh is low in step ST22, the turning characteristic index setting unit 1c uses the existing learning result stored in the storage unit of the electronic control unit 1, and uses the stability factor KH. Is initialized again based on the current total vehicle weight M and the vehicle center-of-gravity position P (step ST23).

  The learning result is the map data shown in FIG. 9 described above. Accordingly, in this step ST23, the current vehicle gross weight M and the vehicle gravity center position P are compared with the map data, and the stability factor KH read as corresponding to the vehicle gross weight M and the vehicle gravity center position P is again obtained. Set as initial value. The initial value here can be said to be a value in line with the current state since the current total vehicle weight M and the vehicle center of gravity position P are taken into consideration when compared with the initial value in step ST12.

  The turning characteristic index setting means 1c sets the stability factor KH in step ST23, returns to step ST15, and again estimates the stability factor KH. In this case, since it is known that the weight reliability trm and the estimated yaw rate response delay coefficient reliability trtp are determined to be high, steps ST17 to ST20 may be omitted and the process may proceed to step ST22. In addition, here, since the information of the total vehicle weight M when the weight reliability trm is high is always highly accurate, the process returns to step ST15. However, the vehicle total weight M, the vehicle gravity center position P, and the stability factor KH are returned. If the relationship is determined with higher accuracy, the process may return to step ST14 to acquire information such as the total vehicle weight M.

  When the turning characteristic index setting means 1c determines that the estimated stability factor reliability trkh is high in step ST22, that is, all of the weight reliability trm, the estimated stability factor reliability trkh, and the estimated yaw rate response delay coefficient reliability trtp. Is determined to be high, it is determined whether or not learning of the turning characteristic index value (stability factor KH and yaw rate response delay coefficient TP) is possible. Here, first, it is determined whether or not the vehicle 10 is stopped (step ST24). Then, if the vehicle 10 is stopped, the turning characteristic index setting unit 1c determines whether or not the vehicle stop time ts has exceeded a predetermined time t2 (step ST25).

  The determinations in steps ST24 and ST25 are determinations as to whether or not the map data in FIGS. 9 and 10 can be updated. For example, when the vehicle is traveling, no passengers get on and off and no cargo is loaded or unloaded, so that the vehicle gross weight M and the vehicle gravity center position P do not change. On the other hand, when the vehicle 10 stops, passengers get on and off and load / unload luggage, and the vehicle total weight M and the vehicle gravity center position P may change. For this reason, when the vehicle stop time ts continues longer than the predetermined time t2, the correspondence relationship between the new vehicle gross weight M and the like, the stability factor KH, and the yaw rate response delay coefficient TP is obtained again, so that the estimated stability The map data shown in FIGS. 9 and 10 is updated based on the factor KHp and the estimated yaw rate response delay coefficient TPp. The predetermined time t2 is set to a time shorter than an average time required for getting on and off passengers and loading / unloading of luggage, for example. Accordingly, when it is determined in step ST24 that the vehicle is traveling, or when it is determined in step ST25 that the vehicle stop time ts does not exceed the predetermined time t2 (ts ≦ t2), the turning characteristic index The setting unit 1c is determined to be unable to learn. On the other hand, when the vehicle stop time ts exceeds the predetermined time t2 in step ST25, the turning characteristic index setting unit 1c determines that learning is possible.

  Here, if it is determined in step ST24 that the vehicle is traveling, the process returns to step ST14, and the estimated stability factor KHp or the estimated yaw rate response delay coefficient TPp corresponding to the total vehicle weight M and the vehicle gravity center position P is returned. A new calculation is performed. If it is determined in step ST25 that the vehicle stop time ts does not exceed the predetermined time t2, the process returns to step ST24. On the other hand, when it is determined in step ST25 that the vehicle stop time ts exceeds the predetermined time t2 and learning is possible, the turning characteristic index setting means 1c determines that the current vehicle gross weight M, the current vehicle gravity center position P, Based on the estimated stability factor KHp and the estimated yaw rate response delay coefficient TPp, the map data of FIG. 9 and FIG. 10 as the learning results are respectively updated (step ST26).

  For example, in this step ST26, an average value is calculated based on the learned value of the existing stability factor KH and the estimated stability factor KHp in the map data of FIG. 9 corresponding to the current vehicle gross weight M and the vehicle gravity center position P. The map data is updated using the average value as a learning value of the new stability factor KH (FIG. 12). Here, the learning value of the stability factor KH before the update represents the result of learning performed in the past. For this reason, when obtaining the average value, the learning value of the stability factor KH before update is multiplied by the past update count N, and the estimated stability factor KHp is added to this to calculate the average at all update counts N + 1. It is desirable to take. Further, weighting may be performed so that the learning value approaches the estimated stability factor KHp as the weight reliability trm and the estimated stability factor reliability trkh are higher.

  Further, in this step ST26, the average based on the existing learned value of the yaw rate response delay coefficient TP and the estimated yaw rate response delay coefficient TPp in the map data of FIG. 10 corresponding to the current total vehicle weight M and the vehicle center of gravity position P. A value is obtained, and the map data is updated using this average value as a learning value of a new yaw rate response delay coefficient TP (FIG. 13). The learning value of the yaw rate response delay coefficient TP before update also represents the result of learning performed in the past. For this reason, when the average value is obtained, the learning value of the yaw rate response delay coefficient TP before update is multiplied by the past update count N, and the estimated yaw rate response delay coefficient TPp is added to this to obtain all update counts N + 1. It is desirable to take an average. Further, the higher the weight reliability trm and the estimated yaw rate response delay coefficient reliability trtp, the higher the learning value may be closer to the estimated yaw rate response delay coefficient TPp.

  Here, in the second embodiment, it is observed whether the vehicle 10 is stopped or traveling, and if it is stopped, the necessity of learning is determined according to the vehicle stop time ts. Alternatively, in step ST24, it may be determined whether or not the ignition is off. If the ignition is off, it may be determined in step ST25 how long the state continues. In this case, it is determined that learning is possible when the ignition-off state continues for a predetermined time.

  The vehicle control device executes the same vehicle control as that of the first embodiment using the learning result updated in consideration of the change in the total vehicle weight M and the vehicle gravity center position P. Therefore, the vehicle control device can turn the vehicle 10 in a desired turning posture according to the current total vehicle weight M and the vehicle center-of-gravity position P.

  By the way, the turning characteristic index setting means 1c according to the second embodiment, after finishing the learning operation in step ST26, sets the vehicle center of gravity position P for each range of the vehicle gross weight M and for each predetermined vehicle center of gravity position P. The standard deviation of the stability factor KH and the yaw rate response delay coefficient TP may be calculated for each range included in the vicinity thereof. Each standard deviation indicates a degree of variation in information of a plurality of estimated stability factors KHp and estimated yaw rate response delay coefficient TPp used for learning. When the standard deviation is large, the accuracy of the stability factor KH and the yaw rate response delay coefficient TP in the learning result is not clear and may not indicate an accurate value. It is preferable not to employ information on stability factor KH or yaw rate response delay coefficient TP. Therefore, in the case of having such a standard deviation calculation function, the turning characteristic index setting means 1c cannot say that the standard deviation of the yaw rate response delay coefficient TP is a predetermined value (for example, the accuracy of the yaw rate response delay coefficient TP in the learning result is high). It may be configured that the re-initialization of step ST21 is performed when the value is smaller than the lower limit value of the value, and the re-initialization of step ST21 is not performed if the standard deviation is larger than a predetermined value. Further, the turning characteristic index setting means 1c is configured to perform the above step when the standard deviation of the stability factor KH is smaller than a predetermined value (for example, a lower limit value of a value at which the accuracy of the stability factor KH in the learning result cannot be said to be high). What is necessary is just to comprise so that re-initialization of ST23 is performed and if the standard deviation is larger than a predetermined value, the re-initialization of step ST23 is not performed.

  Some vehicles 10 have a certain degree of regularity in their usage. For example, when traveling from home to work place on the same route at substantially the same time zone, a case where a predetermined driver carries the same type and quantity of luggage from a certain place to a destination, etc. are applicable. In such a case, the running vehicle total weight M and the vehicle center of gravity position P are also regular, and the accuracy of estimating the stability factor KH and the yaw rate response delay coefficient TP is increased, and the highly accurate learning result is obtained. Can be obtained. Therefore, it is desirable to obtain each standard deviation described above based on the estimated stability factor KHp and the estimated yaw rate response delay coefficient TPp when at least one of the starting point, the destination, and the date / time is the same, High accuracy. Information on the departure point and the destination can be obtained by using map information of the car navigation system, vehicle position information, and the like. As for the date and time, the date and time information of the vehicle 10 or the car navigation system may be used. Then, the turning characteristic index setting means 1c performs the above step when the standard deviation of the yaw rate response delay coefficient TP based on at least one of the starting point, destination and date / time information is smaller than the predetermined value. What is necessary is just to comprise so that re-initialization of ST21 may be performed and the re-initialization of said step ST21 may not be performed if the standard deviation is larger than a predetermined value. Further, the turning characteristic index setting means 1c is configured to perform the above step when the standard deviation of the stability factor KH based on at least one of the starting point, destination, and date / time information is smaller than the predetermined value. What is necessary is just to comprise so that re-initialization of ST23 is performed and if the standard deviation is larger than a predetermined value, the re-initialization of step ST23 is not performed.

  As described above, the estimation accuracy of the stability factor KH and the yaw rate response delay coefficient TP can be determined by using the estimated yaw rate response delay coefficient reliability trtp and the standard deviation. This can also be determined by comparing the inertia moment Iz. For example, the yaw inertia moment Iz1 is obtained from the above equation 10 based on the total vehicle weight M. Further, based on the estimated yaw rate response delay coefficient TPp, the yaw inertia moment Iz2 is obtained from the modified expression of the above expression 3 (the following expression 11). Here, if it is determined by the determination in step ST19 that the information on the total vehicle weight M is highly reliable, the reliability of the yaw inertia moment Iz1 using the information on the total vehicle weight M is also high. Yeah. Therefore, the yaw inertia moment Iz1 and the yaw inertia moment Iz2 are compared, and if the difference between them is smaller than a predetermined value (for example, ≈0), it is determined that the yaw inertia moment Iz2 is a reliable value. Thus, it can be determined that the estimated yaw rate response delay coefficient TPp used for calculating the yaw moment of inertia Iz2 has high estimation accuracy.

  Here, in each of the first and second embodiments described above, the turn control is cited as the vehicle behavior control, but the vehicle behavior control is not necessarily limited to this. For example, the change in the total vehicle weight M and the vehicle center-of-gravity position P changes the front axle weight Mf and the rear axle weight Mr as described above. In traction control that suppresses idling of the drive wheel during start-up or acceleration, when determining the target control amount (target output of the power source or target braking force of the drive wheel) and target control timing, the front axle weight Mf or It is necessary to consider the change in the rear axle weight Mr. For example, if the front axle weight Mf in a front wheel drive vehicle is reduced with respect to a reference state such as a design value, the idling of the drive wheel is not performed unless the target braking force of the drive wheel is increased compared to that in the reference state. May not be properly suppressed. For this reason, in this case, it is necessary for the traction control means to increase the target braking force of the drive wheel in accordance with the decrease in the front shaft weight Mf. The decrease in the front axle weight Mf depends on the amount of change in the total vehicle weight M and the vehicle gravity center position P. Therefore, the vehicle behavior control according to the present invention includes the traction control, and the traction control means is the vehicle control means according to the present invention.

  In each of the first and second embodiments described above, the target control value is changed in accordance with the change in the vehicle gross weight M and the change in the vehicle center of gravity position P accompanying the change in the vehicle gross weight M. The control value may be changed according to the change in the total vehicle weight M. This is because, for example, when the vehicle gross weight M changes in a vehicle in which the load position of the luggage is roughly determined, the change in the vehicle gravity center position P can be estimated by grasping the amount of change in the vehicle gross weight M. This is because an appropriate target control value can be set as long as the change in the total vehicle weight M can be known. Further, according to this, for example, in a vehicle such as a truck where the loading position of the luggage is behind the vehicle with respect to the vehicle center of gravity position P, it is determined that the vehicle center of gravity position P moves toward the rear of the vehicle as the total vehicle weight M increases. be able to. Therefore, the target control value may be changed according to the vehicle center-of-gravity position P as a result of the determination.

  As described above, the vehicle control device according to the present invention is useful as a technique for executing appropriate vehicle behavior control corresponding to changes in the total vehicle weight or the position of the center of gravity of the vehicle.

1 Electronic control unit (ECU)
1a Braking control means 1b Turning control means (vehicle control means)
1c Turning characteristic index setting means 1d Center of gravity position calculating means 1e Weight calculating means 10 Vehicle 20 Steering device 30 Braking device 41 Yaw rate sensor 42 Vehicle speed sensor 43 _FL , 43 _FR , 43 _RL , 43 _RR Wheel speed sensor 44 Steering angle sensor 45 Vehicle lateral acceleration sensor P Vehicle center-of-gravity position _WFL , _WFR , _WRL , _WRR wheel

Claims (6)

In a vehicle control device that controls vehicle behavior at a set target control amount or / and target control timing,
A vehicle control device comprising vehicle control means for changing the target control amount or / and the target control timing in accordance with a change in total vehicle weight. In a vehicle control device that controls vehicle behavior at a set target control amount or / and target control timing,
Vehicle control means is provided for determining that the position of the center of gravity of the vehicle moves toward the rear of the vehicle as the total vehicle weight increases, and for changing the target control amount or / and the target control timing according to the position of the center of gravity of the vehicle. Vehicle control device. In a vehicle control device that controls vehicle behavior at a set target control amount or / and target control timing,
A vehicle control device provided with vehicle control means for changing the target control amount or / and the target control timing in accordance with a change in the total vehicle weight and a change in the center of gravity of the vehicle accompanying a change in the total vehicle weight. . Weight calculation means for estimating or detecting the total vehicle weight, gravity center position calculation means for estimating or detecting the vehicle center of gravity position, and a turning characteristic index value representing a turning characteristic of the vehicle is set according to the vehicle total weight and the vehicle center of gravity position. A turning characteristic index setting means,
The vehicle control means sets the target control amount at which the vehicle takes a desired turning posture based on a running state amount representing a running state of the vehicle and the turning characteristic index value corresponding to the vehicle total weight and the vehicle center of gravity position. 4. The vehicle control device according to claim 3, wherein the vehicle control device is configured as described above.   The vehicle control means obtains a target turning state amount that achieves a desired turning posture based on a running state amount representing a running state of the vehicle, the turning characteristic index value corresponding to the total vehicle weight and the center of gravity of the vehicle, and the target turning state 5. The vehicle control device according to claim 4, wherein the target control amount is set according to a difference between a state amount and an actual turning state amount.   6. The center-of-gravity position calculating means is configured to estimate that the position of the center of gravity of the vehicle has moved to the rear of the vehicle as the amount of change in the total vehicle weight increases toward the increase side. The vehicle control device described in 1.

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