JP2009143402A - Vehicle vibration damping control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain the influence of a decrease in the accuracy of vibration damping control during execution of vehicle height control, in the vibration damping control being designed to restrain pitch-bounce vibration through wheel torque control for a vehicle having a suspension whose elastic modulus is variably controlled. <P>SOLUTION: A drive control device includes a compensation component determining unit for calculating a compensation component for compensating wheel torque in such a way as to reduce the vibration displacement of a body predicted using a body vibration model, and a vehicle height value obtaining unit for obtaining a value that represents the height of the vehicle. The configuration of the compensation component determining unit is changed as a value representing the elastic modulus of the suspension or the vehicle height is varied. A change to the configuration of the compensation component determining unit is achieved either by updating a model parameter or by shutting off or reducing the output of the compensation component. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vibration damping control device for a vehicle such as an automobile, and more specifically, controls a torque (hereinafter referred to as “wheel torque”) that acts between a vehicle wheel and a grounding road surface. The present invention relates to a vibration suppression control device for suppressing vehicle body vibration such as pitch / bounce vibration of a vehicle body.

Vehicle vibrations such as pitch and bounce vibrations while the vehicle is running are generated by braking / driving force (or inertial force) acting on the vehicle body during acceleration / deceleration of the vehicle or other external force acting on the vehicle body. It is reflected in the wheel torque. Therefore, in the field of vehicle vibration suppression control, it has been proposed to adjust the wheel torque through vehicle braking / driving force control to suppress vibration of the vehicle body while the vehicle is running (for example, Patent Documents). 1 and 2). In the vibration suppression control of the vehicle body vibration by the wheel torque or the braking / driving force control, when the fluctuation of the wheel torque due to the acceleration / deceleration request or the turning request of the vehicle is expected, or external force (unevenness or foreign matter on the road surface, A so-called vehicle body when the wheel torque changes due to the action of a dynamic disturbance such as a change in road reaction force or a wind force due to a change in state on the road surface of the vehicle such as a change in gradient or frictional state. Predicts pitch and bounce vibrations generated in the vehicle body and suppresses the predicted vibrations using a motion model of vehicle body vibration that is built on the assumption of a dynamic model of sprung vibration or sprung / unsprung vibration Thus, the torque or braking / driving force of the wheel is adjusted. In the case of this type of vibration suppression control, the generation of vibration energy is suppressed by adjusting the source of the force that generates vibration, rather than by absorbing vibration energy generated as in the case of vibration suppression control by the suspension. Therefore, the vibration damping action is relatively quick and the energy efficiency is good. Further, in the vibration damping control as described above, since the object to be controlled is concentrated on the wheel torque or the braking / driving force of the wheel, the control adjustment is relatively easy.
JP 2004-168148 A JP 2006-69472 A

  By the way, as a structure of a suspension of a vehicle such as an automobile, there is known a structure in which its elastic modulus can be increased or decreased like a so-called “electronically controlled air suspension”. In short, in such a suspension, the vehicle height is controlled to be maintained at a predetermined value by adjusting the magnitude of the elastic modulus while monitoring the vehicle height with a sensor (vehicles). High control). According to this function, the vehicle height can be maintained substantially constant even when the vehicle load and the number of passengers change, or the vehicle height can be changed up and down by the driver's selection or according to the running state of the vehicle. Is possible. And, by keeping the vehicle height constant (auto-leveling function), the change in air resistance and lift in the running vehicle is reduced, a constant wheel stroke is obtained, or the irradiation angle of the headlamp Advantages relating to running stability and safety, such as less change in vehicle speed, can be obtained. Also, by changing the vehicle height by changing the elastic modulus of the suspension, it is possible to improve running performance on rough terrain (when the vehicle height is increased), to improve running stability or aerodynamic characteristics at high speeds, and to load and unload luggage. Various advantages such as improvement in performance (when the vehicle height is lowered) can be obtained.

  However, in a vehicle in which vehicle height control is executed as described above, when the vibration suppression control by the wheel torque control is executed, the vibration suppression control is performed by changing the elastic modulus of the suspension or the vehicle height by the vehicle height control. Accuracy may deteriorate. In the vibration suppression control by the wheel torque control described above, as already mentioned, the compensation component for the wheel torque (the torque of the wheel torque is set so as to suppress the vibration predicted based on the sprung vibration of the vehicle body or the sprung / unsprung vibration model. The compensation component is given as a control command to an actuator that executes wheel torque control, that is, a driving device, a braking device, or a steering device of a vehicle such as an engine or a motor, and is estimated from a motion model. Vehicle body vibration is suppressed. At this time, in the sprung vibration or sprung / unsprung vibration model that is the basis of the vibration damping control, quantities such as the elastic modulus of the suspension, the vehicle height, the vehicle weight, and the inertia moment of the vehicle body are used as parameters. Therefore, when a characteristic value such as the elastic modulus of the suspension (a damping factor may be included) is changed or a vehicle height is changed by the vehicle height control as described above, the spring used in the vibration suppression control is executed. The difference between the upper vibration model or the sprung / unsprung vibration model and the actual vehicle state can be large (changes in the spring's vibration mode (resonance frequency, damping time, etc.) due to changes in the elastic modulus of the suspension, etc. Will do.) In addition, the vehicle height control makes it possible to maintain the vehicle height substantially constant even when the vehicle load and the number of passengers change, but in that situation, the vehicle weight and the moment of inertia in the pitch / bounce direction of the vehicle body (The vehicle height is determined by the balance between the elastic force of the suspension and the vehicle weight in accordance with Hooke's law). Thus, during execution of the vehicle height control, the vehicle vibration model error (modeling error) increases, thereby degrading the accuracy of the compensation component for the wheel torque.

  Accordingly, the main problem to be solved by the present invention is that in a vehicle in which vehicle height control can be executed, vibration suppression control by wheel torque control is executed, and in vehicle height control or vehicle height control. This avoids the effects of deterioration in the accuracy of damping control caused by changes in the characteristic parameters of the vehicle parts that contribute to the body vibration involved, and preferably provides a good damping effect even if there are changes in the characteristic parameters of the vehicle parts. Is to be able to.

  According to the present invention, there is provided a vibration damping control device for a vehicle that suppresses pitch bounce vibration of the vehicle by controlling wheel torque generated at a contact point between the vehicle wheel and the road surface, and the elastic modulus is changed. It is mounted on a vehicle having a suspension that can be controlled, and is configured to be able to avoid or reduce the influence of deterioration in accuracy of vibration suppression control when executing control of increase / decrease in elastic modulus of the suspension or vehicle height control using the suspension. A vibration control device is provided.

  A vibration suppression control apparatus according to the present invention includes a compensation component determination unit that calculates a compensation component for compensating for wheel torque so as to reduce vibration displacement of a vehicle body predicted using a vehicle body vibration model of the vehicle, and a vehicle height of the vehicle. And a vehicle height value acquisition unit that acquires a value that represents the difference, and the configuration of the compensation component determination unit is changed when the value representing the elastic modulus of the suspension or the vehicle height changes. That is, the vibration suppression control device of the present invention basically has a vehicle body pitch / frequency that can be generated by a driver or a braking / driving request (or turning request) by automatic driving control or a disturbance acting on the vehicle body while the vehicle is running. It is a vibration suppression control device of a type that compensates for wheel torque so as to reduce or cancel body vibration such as bounce. In such a vibration suppression control device, typically, the compensation component calculated by the compensation component determination unit is a required value of drive torque (or vehicle braking) applied to a vehicle drive device such as an engine or a motor. The component causing the vehicle body vibration included in the drive torque request value is reduced or eliminated, or the vehicle body vibration due to the disturbance acting on the vehicle body is reduced. The drive torque is controlled in a direction that cancels out the action of the component (vibration force) that is induced, and the wheel torque at the wheel is compensated.

  However, in a vehicle capable of variably controlling the elastic modulus of the suspension, as described above, the vehicle height can be kept substantially constant for various purposes even if the load capacity or the number of passengers changes. In order to increase or decrease, control of the elastic modulus of the suspension (for example, vehicle height control such as AHC) may be executed. In this case, the vehicle body vibration model of the vehicle of the compensation component determining unit is different from the actual vehicle state. In other words, an error in modeling the vehicle body vibration (modeling error) and the effect of the vibration suppression control based on this. Deterioration of the effect can occur. Therefore, in the configuration of the present invention, a vehicle height value acquisition unit that acquires a value representing the vehicle height of the vehicle is provided, and the vehicle height is monitored, and the elastic modulus of the suspension or the value representing the vehicle height has changed. Sometimes, the configuration of the compensation component determination unit is changed, so that the influence due to the deterioration of the accuracy of the vibration suppression control can be avoided. The value representing the vehicle height may be given from the detection value of the vehicle height sensor used in the known vehicle height control or the detection value of the stroke sensor of the suspension. The vehicle height value may be used (the above-mentioned “vehicle height acquisition unit” is the name of the part, and does not necessarily acquire the vehicle height value itself, and is actually acquired there. The thing may be a value that can be treated as equivalent to the vehicle height value, or a value that represents a change in vehicle height. The elastic modulus of the suspension may be given from a control device that performs the variable control.

  In one aspect, the compensation component determination unit can be changed by changing various parameters used in the vehicle body vibration model in the compensation component determination unit to their current actual values or their estimated values. A good vibration damping effect may be maintained. For example, when the vehicle height and the elastic modulus of the suspension change, the elastic modulus of the suspension of the vehicle body vibration model, the vehicle weight, or the parameters used for the vehicle body vibration model are based on the change in those values. The value or its estimated value may be changed. In addition, since the moment of inertia may vary greatly as the vehicle weight changes, the inertia moment of the vehicle body may be changed to the current actual value or estimated value. The vehicle weight and the moment of inertia may be detected or estimated by an arbitrary method. For example, when a load sensor is provided for each wheel, the vehicle weight may be calculated from the detected values, but the change in the elastic modulus of the suspension and the vehicle height (the vehicle height change is 0). In some cases, such as when the so-called auto-leveling function is performed), for example, it may be inferred from Hooke's law. Further, the moment of inertia may be estimated based on detection values of load sensors provided on the front and rear seats and the trunk of the vehicle (see the section of the embodiment described later). Furthermore, the variable control of the elastic modulus of the suspension is typically for maintaining the vehicle height substantially constant, but as described above, in order to positively increase or decrease the vehicle height for various purposes. Sometimes used. In such a case, when the vehicle height value of the center of gravity is a parameter in the vehicle body vibration model, the value is different from the actual value. In that case, the vehicle height value at the center of gravity of the vehicle of the vehicle body vibration model in the compensation component determination unit may be changed. Further, the current value of the vehicle height value is obtained, for example, by the vehicle height value acquisition unit acquiring the front wheel side vehicle height value at the front wheel of the vehicle and the rear wheel side vehicle height value at the rear wheel of the vehicle, and the front wheel side vehicle height value. And the rear wheel side vehicle height value.

  Thus, according to the aspect of changing the parameters of the vehicle body vibration model, the effect of the vibration suppression control can be achieved even if the variable control of the elastic modulus of the suspension is executed by accurately correcting the parameters of the vehicle body vibration model. It is expected that a good vibration damping effect is achieved by suppressing the deterioration of the above.

  However, in the above aspect, it is executed in a running vehicle, and detection of the current value of each parameter or its estimated value is not always executed with high accuracy. In the situation where the vehicle height control is adjusted for the elastic modulus of the suspension, even if the vehicle height is kept constant, at least some actual values of the parameters used in the vehicle body vibration model are the initial values (usually normal The values when the vehicle weight and the vehicle height are typical or standard values are adopted.) Of course, it is possible in principle to accurately grasp all of them and reflect all of their deviations in the model, but in practice it may be difficult, and the configuration and actuality of the body vibration model There may be unexpected errors with the corresponding configuration of the vehicle. Therefore, as another aspect of the change in the configuration of the compensation component determination unit, an amount representing a deviation between the current value and the initial value of at least a part of the parameters used for the elastic modulus of the suspension, the vehicle weight, or other vehicle vibration model. When the value deviates from a predetermined allowable range, the output of the compensation component from the compensation component determination unit may be stopped. In particular, even when the vehicle height is increased or decreased by the vehicle height control, there may be an unexpected error between the configuration of the vehicle body vibration model and the corresponding configuration of the actual vehicle. In order to avoid the influence of such an error, when the amount representing the difference between the vehicle height value acquired by the vehicle height acquisition unit and the vehicle height value used in the vehicle body vibration model deviates from a predetermined allowable range, a compensation component The output of the compensation component from the determination unit may be stopped. That is, when the parameter used for the vehicle body vibration model or the vehicle height value fluctuates greatly, the vibration suppression control is interrupted, so that no malfunction occurs due to the deterioration of the accuracy of the vibration suppression control due to the modeling error. It's okay.

  The configuration for interrupting the output of the compensation component when the parameter used for the vehicle body vibration model or the vehicle height value is large is determined by whether or not the above-described configuration for changing the parameters of the vehicle body vibration model is provided. It may be used regardless. In the configuration for changing the parameters of the vehicle body vibration model, it is necessary to separately incorporate an algorithm for changing the parameters in the arithmetic processing unit. Therefore, in order to avoid the complexity of such a configuration, only the configuration for interrupting the output of the compensation component may be provided in the vibration suppression control device.

  Further, preferably, the change in the configuration of the compensation component determination unit in the series of aspects described above is executed after a predetermined time has elapsed since the change in the value representing the elastic modulus of the suspension or the vehicle height has occurred. You may be supposed to. The value representing the elastic modulus of the suspension or the vehicle height can change transiently or transiently. However, if the configuration of the compensation component determination unit is changed following such a change, frequent compensation components A phenomenon such as a change in the configuration of the determining unit or a sudden change in the compensation component may occur, and the stability of control may be reduced. Therefore, as described above, when a change in the value indicating the elastic modulus of the suspension or the vehicle height occurs, the change in the value indicating the elastic modulus of the suspension or the vehicle height continues to some extent, and the configuration of the compensation component determination unit is changed. The configuration of the compensation component determination unit may actually be changed when the need for the above becomes high. As a result, it is possible to eliminate the influence of the modeling error in a state where a control step and a sudden change are avoided.

  Furthermore, in addition to the above configuration, if the damping rate and other mechanical characteristics of the suspension can be changed along with the change in the elastic modulus of the suspension, the vibration suppression control device The value after the change may be acquired and reflected in the vehicle body vibration model.

  According to the present invention, it is possible to perform variable control of the elastic modulus of the suspension, thereby avoiding the deterioration of the vibration damping effect due to the change of the elastic modulus of the suspension in the vehicle capable of controlling the vehicle height. Therefore, a vibration damping control device that can handle the above problem is provided. As will be understood from the following embodiments, the wheel torque compensation component by the vehicle body vibration damping control device is vibrationally driven by the drive device (or brake) corresponding to the amplitude, phase and frequency of the vehicle body vibration that can occur. The output of the device or steering device is increased or decreased. Therefore, if the actual vehicle modeling error of the vehicle body vibration model becomes large, the compensation component differs not only in amplitude but also in phase and frequency from vehicle body vibration, thereby amplifying the vibration to be suppressed. There is a possibility. In particular, the elastic modulus of the suspension, which is an adjustment target for vehicle height control, greatly contributes to the determination of the resonance frequency of the pitch / bounce vibration of the vehicle body, as well as the vehicle weight and the moment of inertia. In the present invention, by correcting the part that determines the compensation component in response to the change in the parameter that can greatly influence the characteristics of the vibration to be suppressed, the vibration control and the vehicle height control can be performed as much as possible. It can be said that the problem does not occur, and thereby the range (such as the type and form of the vehicle) to which the vibration suppression control can be applied can be expanded. It should be understood that the concept of the present invention may be applied to a vehicle in which vehicle height control is not executed.

  Other objects and advantages of the present invention will become apparent from the following description of preferred embodiments of the present invention.

  The present invention will now be described in detail with reference to a few preferred embodiments with reference to the accompanying drawings. In the figure, the same reference numerals indicate the same parts.

Diagram 1 of the apparatus is a vehicle such as an automobile in which the preferred embodiment of the vibration damping control device is mounted of the present invention is schematically shown. In the figure, a vehicle 10 having left and right front wheels 12FL and 12FR and left and right rear wheels 12RL and 12RR is driven in the normal manner according to the depression of the accelerator pedal 14 by the driver. A drive device 20 that generates torque is mounted. In the example shown in the figure, the drive device 20 has a drive torque or a rotational drive force from the engine 22 to the torque converter 24, the automatic transmission 26, the differential gear device 28, etc., as illustrated in FIG. Via the rear wheels 12RL and 12RR. However, the drive device may be an electric drive in which an electric motor is used instead of the engine 22 or a hybrid drive device having both an engine and an electric motor. The vehicle may be a four-wheel drive vehicle or a front wheel drive vehicle.

  Further, in the illustrated vehicle 10, as schematically illustrated in FIG. 1B, the vehicle body frame 36 (partially shown) is used as a suspension for supporting the vehicle body on the axle. Electronically controlled air suspensions 32f and 32r are disposed between the front axle 34f and the rear axle 34r in association with each wheel (only the left side is shown in the figure). Vehicle height sensors 38FR to RL for measuring the distance between 34f and r are provided. The air suspensions 32f and 32r may have, for example, an air cylinder or an air spring (c) and a shock absorber (a), and the air pressure inside the air cylinder (c) may be an air compressor, an air valve, or the like. It can be adjusted by an air pressure control system (not shown) including the air cylinder, whereby the elastic modulus of the air cylinder can be increased or decreased. The vehicle height, that is, the height of the "spring top" vehicle body is determined by the balance between the gravity and the elastic force of the air cylinder. In the above configuration, the vehicle height sensor 38f is controlled under the control of the electronic control unit. , R while monitoring the vehicle height or the change in the vehicle height so that the vehicle height becomes substantially constant regardless of the load capacity of the vehicle, the number of passengers, that is, the “weight on the spring”, or So-called “vehicle height control” is performed in which the elastic modulus of the air cylinder is adjusted to be set to an arbitrary value. The vehicle height control and the air cylinder air pressure control may be executed in a known manner.

  Further, although not shown for simplicity, the vehicle 10 includes a braking system device that generates a braking force on each wheel in response to the depression of the brake pedal 16 and the steering angle of the front wheels or the front and rear wheels, as in a normal vehicle. A steering device for controlling the motor is provided.

  Operation control of each part of the vehicle, such as operation control and vehicle height control of the drive device 20 and air pressure control of the air cylinder, is controlled by the electronic control device 50. The electronic control unit 50 may include a microcomputer having a CPU, a ROM, a RAM, and an input / output port device, which are connected to each other by a bidirectional common bus, and a driving circuit. The electronic control unit 50 includes a signal Vwi (i = FL, FR, RL, RR) representing a wheel speed from a wheel speed sensor 30i (i = FL, FR, RL, RR) mounted on each wheel, a vehicle The engine rotation speed ne from the sensors provided in each part of the engine, the transmission rotation speed no, the accelerator pedal depression amount θa, the brake pedal depression amount θb, the longitudinal acceleration of the vehicle, and the stroke from the stroke sensor provided on the suspension A signal such as an amount, a vehicle height change amount from the vehicle height sensors 38f, r is input. Furthermore, in the present embodiment, between the seats 40f, 40r of the front and rear seats and the body bottom portion 37 (or frame 36) and between the bottom plate 40t of the trunk and the body bottom portion 37 (or frame 36), respectively. Detection values (loads) from the provided load sensors 42f, 42r, and 42t may be input to the electronic control unit 50 in order to detect a change in the inertia moment in the pitch direction of the vehicle body. In addition to the above, various detection signals for obtaining various parameters necessary for various controls to be executed in the vehicle of the present embodiment, for example, each from a load sensor that may be arbitrarily provided on each wheel It should be understood that a signal representing wheel load, engine output shaft torque, etc. may be input.

  The vibration damping control device of the present invention is realized in the electronic control device 50 described above. FIG. 2 shows the internal configuration of an embodiment of such an electronic control device 50 in the form of a control block.

  Referring to FIG. 2, an electronic control unit 50 includes a drive control unit 50a for controlling the operation of the engine, a braking control unit 50b for controlling the operation of a braking unit (not shown), and monitoring the vehicle height. A vehicle height control device 50c that performs adjustment, an air suspension control device 50d that performs operation control of the air suspension air pressure control system, and various control devices (not shown) that are equipped in a known electronic control device of a vehicle. You can leave. It is understood that the configuration and operation of various control devices such as a drive control device including a vibration suppression control device are realized by processing operations of the CPU and the like in the electronic control device 50 during operation of the vehicle. Should.

  As shown in the figure, the braking control device 50b includes a pulse-type electric power that is sequentially generated every time the wheel rotates by a predetermined amount from the wheel speed sensor 30i (i = FR, FL, RR, RL) of each wheel. The wheel rotational speed ω is calculated by measuring the time interval between arrival of such sequentially input pulse signals, and the wheel radius value r · ω is multiplied by the wheel rotational speed r. Is calculated. Then, the wheel speed value r · ω is transmitted to the drive control device 50a (wheel torque estimator 52c) and used for calculation of the wheel torque estimated value in order to execute vibration suppression control which will be described in detail later. . The calculation from the wheel rotation speed to the wheel speed may be performed by the drive control device 50a. In this case, the wheel rotation speed is given from the braking control device 50b to the drive control device 50a.

  As a basic configuration, the drive control device 50a has a drive torque request value determining unit 51 that determines the engine drive torque request value requested by the driver based on the accelerator pedal depression amount or the accelerator opening θa from the accelerator pedal sensor. A compensation component determining unit 52 that calculates a compensation component for executing vehicle body pitch / bounce vibration damping control by wheel torque (drive torque) control to compensate (correct) the drive torque request value, and the compensation component Based on the drive torque request value compensated by the compensation component calculated by the determination unit, a control command for each part of the engine is generated in an arbitrary known format and a corresponding controller (not shown) is achieved. Control command determination unit 53 to be transmitted to

  In such a basic configuration, the drive torque request value determination unit 51 may determine and output a drive torque request value (before compensation) corresponding to the accelerator opening θa by any known method. . Note that the “accelerator opening” means the amount of depression or operation of the accelerator pedal by the driver of the vehicle, or in the case of a vehicle equipped with an automatic travel control device (not shown). It is an amount that represents the required amount of drive torque or drive output, and represents the required amount of acceleration / deceleration force or braking / driving torque for the vehicle. The unit of the drive torque request value may be basically the drive torque in the engine, but in the case of a gasoline engine, the intake air amount or throttle opening, in the case of a diesel engine, the fuel injection amount, the motor If so, it may be a current value (hereinafter, unless otherwise specified, the unit of the drive torque request value is the drive torque in the engine).

  As shown in the figure, the compensation component determination unit 52 converts the drive torque request value (before compensation) determined by the drive torque request value determination unit 51 into a wheel torque (wheel torque request value), and wheel torque estimation. 52c receives the estimated value of the wheel torque currently acting on the wheel estimated from the wheel speed r · ω, and determines the required value and estimated value of the wheel torque in the manner described in detail later. A compensation component (K · X) that reduces or cancels a vibration component that can cause pitch bounce vibration in the vehicle body is calculated. When the wheel torque Tw is input, in order to adjust the balance of the contribution between the driver requested wheel torque Tw0 and the estimated wheel torque value Tw in an after-mentioned motion model, the wheel torque Tw is a feedback control gain (input). The gain may be input after being multiplied by λin (multiplier 52d). Still further, the compensation component determination unit may calculate a compensation component for damping pitch / bounce vibration caused by a change in wheel torque generated in the wheel by a driver's brake operation or steering operation. In that case, as indicated by a dotted line in the figure, a wheel torque estimated value estimated based on the brake operation amount or the steering operation amount by the wheel torque estimator 52x is input to the compensation component determination unit, and the wheel The compensation component is calculated in the same manner as the torque request value and the like. The estimation of the change amount of the wheel torque based on the brake operation amount or the steering operation amount may be performed by an arbitrary method.

  Thus, the compensation component (K · X) calculated by the compensation component determination unit 52 is converted into a unit of the drive torque request value (compensation component U), transmitted to the adder a1, and is sent to the adder a1. Thus, the drive torque request value is compensated by superimposing the compensation component on the drive torque request value (before compensation) (in the illustrated example, the compensation component U is subtracted from the drive torque request value). ). When the compensation component (K · X) is output from the compensation component determination unit 52, a multiplier 52f that multiplies the compensation component K · X by the control gain λout to adjust the contribution of the compensation component for an arbitrary purpose. (That is, the compensation component is sent to the adder a1 in the state of λout · K · X). Then, the control command determination unit 53 is experimentally or theoretically determined in advance based on the compensated drive torque request value with reference to the engine speed and / or the engine temperature at that time. Using a map, in a known manner, control commands to drive units (not shown) of each part of the engine are determined and control commands are transmitted to the drive units so as to achieve drive torque. .

  In short, the vehicle height control device 50c and the air suspension control device 50d refer to the detection amounts of the vehicle height sensors 38FR to 38RL so that the vehicle height is maintained substantially constant, or the vehicle height increases or decreases. Therefore, the elastic modulus (spring constant) is controlled by adjusting the air pressure of the air suspension. Such vehicle height control and air suspension control may be of any known type. Typically, this is executed together with suspension damping force control such as AVS (Adaptive Variable Suspension) system or TEMS (Toyota Electric Modulated Suspension) to optimize the ride comfort of the vehicle occupant. Specifically, the vehicle height control device 50c receives signals from the vehicle height sensors 38FR to 38RL, detects the current vehicle height value or the amount of change in the vehicle height, and sets the air so that the vehicle height value becomes a set value. A control command is given to the suspension control device 50d, and the air suspension control device 50d gives a control command to the compressor valve of the pneumatic control system in order to adjust the elastic modulus (spring constant) and damping coefficient of the air suspension. It may be. Further, the vehicle height control device 50c is provided with an input of a vehicle height setting switch 60 operated by the driver, whereby the driver may be able to change the vehicle height to a desired setting ( Usually, there are three levels of high, normal, and low, but the number of levels that can be set may be less or more than three.)

  Thus, according to the above configuration, in the vehicle, on the other hand, vibration suppression of pitch / bounce vibration by the vibration suppression control device (compensation component determination unit 52 and the configuration associated therewith) realized in the drive control device. On the other hand, the vehicle height control by the vehicle height control device 50c and the air suspension control device is executed. In that case, in the vibration suppression control, a compensation component for suppressing the vibration is calculated based on a vehicle body vibration model using parameters such as the elastic modulus and damping rate of the suspension, the vehicle height, the vehicle weight, and the inertia moment of the vehicle body. Compensation of the drive output (drive torque) of the control device is performed, but if the vehicle height control changes the elastic modulus and damping rate of the suspension, the vehicle height, etc., the actual vehicle vibration model used in the vibration suppression control (actual The error (with respect to the condition of the vehicle) is increased, and therefore the accuracy of the compensation component is degraded. Therefore, in this embodiment, in order to reduce the influence of an increase in the error of the vehicle body vibration model, the model changing unit 52e is provided, the vehicle height control is activated, and the vehicle has an elastic modulus of the air suspension. Is in a state of being fluctuated, the parameter used in the vehicle body vibration model is updated (update of the operator component), or the damping control is interrupted or the contribution is reduced (the configuration of the compensation component determining unit is changed). Executed.

Operation of the Device Hereinafter, the configuration and operation of the control device illustrated in FIG. 2 will be described in detail. It should be understood that in the illustrated example, the vibration suppression control device is realized with the compensation component determination unit 52 and the model change unit 52e as main components in the drive control device.

(I) Pitch / bounce vibration suppression control In the above configuration, the pitch / bounce vibration suppression control by the compensation component calculated by the compensation component determination unit 52 of FIG. 2 may be performed in the following manner. .

(Principle of vibration suppression control)
In the vehicle, when the driving device is activated based on the driving request of the driver and the wheel torque fluctuates, the vertical position of the center of gravity Cg of the vehicle body in the vehicle body 10 as illustrated in FIG. The bounce vibration in the direction (z direction) and the pitch vibration in the pitch direction (θ direction) around the center of gravity of the vehicle body can occur. In addition, if a force or torque (disturbance) acts on wheels due to changes in road surface conditions or wind while the vehicle is running, the disturbance is transmitted to the vehicle, and vibrations in the bounce direction and pitch direction are also generated in the vehicle body. obtain. Therefore, in the pitch bounce vibration damping control exemplified here, a motion model of the pitch bounce vibration of the vehicle body is constructed, and the drive torque request value converted into wheel torque in that model (wheel torque Required value) and / or vehicle body displacement z and θ and their rate of change dz / dt and dθ / dt when the current wheel torque estimation value is input, that is, a state variable of vehicle body vibration is calculated and obtained from the model. The drive torque of the drive device (engine) is adjusted so that the state variable converges to 0, that is, the pitch / bounce vibration is suppressed (the drive torque request value is compensated).

ここに於いて、Ｌｆ、Ｌｒは、それぞれ、重心から前輪軸及び後輪軸までの距離であり、ｒは、車輪半径であり、ｈは、重心の路面からの高さ（即ち、重心の車高）である。なお、式（１ａ）に於いて、第１、２項は、前輪軸から、第３、４項は、後輪軸からの力の成分であり、式（１ｂ）に於いて、第１項は、前輪軸から、第２項は、後輪軸からの力のモーメント成分である。式（１ｂ）に於ける第３項は、駆動輪に於いて発生する車輪トルクＴが車体の重心周りに与える力のモーメント成分である。 Thus, first, as a dynamic motion model in the bounce direction and the pitch direction of the vehicle body in the vibration suppression control, for example, as shown in FIG. 3B, the vehicle body is a rigid body S having a mass M and an inertia moment I. It is assumed that the rigid body S is supported by a front wheel suspension having an elastic modulus kf and a damping rate cf, and a rear wheel suspension having an elastic modulus kr and a damping rate cr (vehicle body sprung vibration model). In this case, the motion equation in the bounce direction and the motion equation in the pitch direction of the center of gravity of the vehicle body are expressed as the following Equation 1.

Here, Lf and Lr are distances from the center of gravity to the front wheel shaft and the rear wheel shaft, r is a wheel radius, and h is the height of the center of gravity from the road surface (that is, the vehicle height of the center of gravity). ). In the equation (1a), the first and second terms are components of the force from the front wheel shaft, the third and fourth terms are components of the force from the rear wheel shaft, and in the equation (1b), the first term is From the front wheel shaft, the second term is the moment component of the force from the rear wheel shaft. The third term in the equation (1b) is a moment component of the force that the wheel torque T generated in the drive wheel gives to the periphery of the center of gravity of the vehicle body.

であり、行列Ａの各要素a1-a4及びb1-b4は、それぞれ、式（１ａ）、（１ｂ）のｚ、θ、ｄｚ／ｄｔ、ｄθ／ｄｔの係数をまとめることにより与えられ、
a1=-(kf+kr)/M、a2=-(cf+cr)/M、
a3=-(kf・Lf-kr・Lr)/M、a4=-(cf・Lf-cr・Lr)/M、
b1=-(Lf・kf-Lr・kr)/I、b2=-(Lf・cf-Lr・cr)/I、
b3=-(Lf²・kf+Lr²・kr)/I、b4=-(Lf²・cf+Lr²・cr)/I
である。また、ｕ(t)は、
ｕ(t)＝Ｔ
であり、状態方程式（２ａ）にて表されるシステムの入力である。従って、式（１ｂ）より、行列Ｂの要素p1は、
p1=h/(I・r)
である。 The above formulas (1a) and (1b) are expressed as (linear) as shown in the following formula (2a) with the vehicle body displacements z and θ and their change rates dz / dt and dθ / dt as the state variable vector X (t). It can be rewritten in the form of a system state equation.
dX (t) / dt = A · X (t) + B · u (t) (2a)
Here, X (t), A, and B are respectively

And each element a1-a4 and b1-b4 of the matrix A is given by combining the coefficients of z, θ, dz / dt, dθ / dt in the equations (1a) and (1b), respectively.
a1 =-(kf + kr) / M, a2 =-(cf + cr) / M,
a3 =-(kf ・ Lf-kr ・ Lr) / M, a4 =-(cf ・ Lf-cr ・ Lr) / M,
b1 =-(Lf ・ kf-Lr ・ kr) / I, b2 =-(Lf ・ cf-Lr ・ cr) / I,
b3 =-(Lf ²・ kf + Lr ²・ kr) / I, b4 =-(Lf ²・ cf + Lr ²・ cr) / I
It is. U (t) is
u (t) = T
And is an input of the system represented by the state equation (2a). Therefore, from equation (1b), the element p1 of the matrix B is
p1 = h / (I ・ r)
It is.

In the equation of state (2a)
u (t) = − K · X (t) (2b)
Then, the equation of state (2a) is
dX (t) / dt = (A-BK) .X (t) (2c)
It becomes. Accordingly, the initial value X ₀ (t) of X (t) is set as X ₀ (t) = (0,0,0,0) (assuming that there is no vibration before torque is input). ), The gain that converges the magnitude of X (t), that is, the displacement in the bounce direction and the pitch direction and its time change rate, to 0 when the differential equation (2c) of the state variable vector X (t) is solved When K is determined, a torque value u (t) for suppressing pitch bounce vibration is determined. A value obtained by converting the torque value u (t) into an engine drive torque request value is a compensation component given to the engine by vibration suppression control.

The gain K can be determined by using a so-called optimal regulator theory. According to this theory, a quadratic evaluation function J = 1/2 · ∫ (X ^T QX + u ^T Ru) dt (3a)
(Integral range is 0 to ∞)
When the value of is the minimum, the matrix K that minimizes the evaluation function J by the stable convergence of X (t) in the state equation (2a) is
K = R ⁻¹・ B ^T・ P
It is known to be given by Where P is the Riccati equation
^{-dP / dt = A T P +} PA + Q-PBR -1 B T P
Is the solution. The Riccati equation can be solved by any method known in the field of linear systems, which determines the gain K.

などと置いて、式（３ａ）に於いて、状態ベクトルの成分のうち、特定のもの、例えば、ｄｚ／ｄｔ、ｄθ／ｄｔ、のノルム（大きさ）をその他の成分、例えば、ｚ、θ、のノルムより大きく設定すると、ノルムを大きく設定された成分が相対的に、より安定的に収束されることとなる。また、Ｑの成分の値ｑ１〜ｑ４を大きくすると、過渡特性重視、即ち、状態ベクトルの値が速やかに安定値に収束し、Ｒの値ρを大きくすると、消費エネルギーが低減される。 Q and R in the evaluation function J and Riccati equation are a semi-positive definite symmetric matrix and a positive definite symmetric matrix, respectively, which are arbitrarily set, and are weight matrices of the evaluation function J determined by the system designer. For example, in the case of the motion model considered here, Q and R are

In Equation (3a), a specific one of the components of the state vector, for example, the norm (magnitude) of dz / dt, dθ / dt, and the other components, for example, z, θ If the value is set larger than the norm of, the component having the larger norm is converged relatively stably. Further, when the Q component values q1 to q4 are increased, the transient characteristics are emphasized, that is, the value of the state vector quickly converges to a stable value, and when the R value ρ is increased, the energy consumption is reduced.

ここに於いて、xf、xrは、前輪、後輪のばね下変位量であり、mf、mrは、前輪、後輪のばね下の質量である。式（４ａ）−（４ｂ）は、ｚ、θ、xf、xrとその時間微分値を状態変数ベクトルとして、図３（Ｂ）の場合と同様に、式（２ａ）の如き状態方程式を構成し（ただし、行列Ａは、８行８列、行列Ｂは、８行１列となる。）、最適レギュレータの理論に従って、状態変数ベクトルの大きさを０に収束させるゲイン行列Ｋを決定することができる。 As a dynamic motion model in the bounce direction and the pitch direction of the vehicle body, for example, as shown in FIG. 3C, in addition to the configuration in FIG. 3B, the spring elasticity of the front and rear tires A model that takes into account the above (vehicle body sprung / lower vibration model) may be employed. Assuming that the front and rear tires have the respective elastic moduli ktf and ktr, the motion equation in the bounce direction and the motion equation in the pitch direction of the center of gravity of the vehicle body are as understood from FIG. The following equation 4 is expressed.

Here, xf and xr are unsprung displacement amounts of the front and rear wheels, and mf and mr are unsprung masses of the front and rear wheels. Equations (4a)-(4b) form a state equation as shown in Equation (2a) using z, θ, xf, xr and their time differential values as state variable vectors, as in FIG. 3B. (However, the matrix A has 8 rows and 8 columns and the matrix B has 8 rows and 1 column.) According to the theory of the optimal regulator, the gain matrix K that converges the magnitude of the state variable vector to 0 can be determined. it can.

(Configuration of compensation component determination unit)
The configuration of the control process in the compensation component determination unit 52 in FIG. 2 for calculating the compensation component U for the pitch / bounce vibration suppression control is shown in the form of a control block in FIG. ing. In the control configuration of FIG. 3D, first, the wheel torque request value Two obtained by converting the drive torque request value from the drive torque request determination unit 51 into the wheel torque to the wheel torque input end of the motion model. Each wheel torque (estimated value) Tw currently generated in the wheel is input (in addition, an estimated wheel torque value corresponding to the brake operation amount or the steering operation amount is input as indicated by the dotted line in the figure). You may be supposed to be.) Next, in the motion model, the state variable vector X (t) is calculated by solving the differential equation (2a) using the torque input value T (= Two + Tw). A value K · X (= −u (t)) obtained by multiplying the state vector X (t) by the gain K determined to converge the state variable vector X (t) to 0 or the minimum value as described above. Is calculated, and K · X is converted into a compensation component U in units of engine drive torque request values. The compensation component calculated in this way is transmitted to the adder a1, and is superposed on the drive torque request value in the adder a1, so that the component corresponding to the value of K · X (t) becomes the drive torque request value. Will be deducted from. The body pitch / bounce vibration system is a resonance system as understood from equations (1a) and (1b), and the value of the state variable vector X (t) is substantially equal to an arbitrary input. Only the frequency components in a band (usually about 1 to 5 Hz) having a certain spectral characteristic with the natural frequency of the system as the center. Accordingly, by subtracting K · X (t) from the drive torque request value as described above, the natural frequency component of the system of the drive torque request value or the currently generated wheel torque, that is, in the vehicle body. Thus, components that cause pitch bounce vibration are reduced or eliminated, and pitch bounce vibration in the vehicle body is suppressed.

(Estimation of wheel torque)
For the motion model shown in FIG. 3D, the wheel torque value Tw that is actually generated, which is input as a disturbance effect, is ideally detected by providing a torque sensor for each wheel. However, it is difficult to provide a torque sensor on each wheel of a normal vehicle. Therefore, in the illustrated example, the wheel torque estimated value estimated by the wheel torque estimator 52c (FIG. 2) from other detectable values in the running vehicle is used as the disturbance input of the wheel torque. The wheel torque estimated value Tw is typically obtained by using a wheel rotational speed ω obtained from a wheel speed sensor of a driving wheel or a time derivative of a wheel speed value r · ω,
Tw = M · r ² · dω / dt (5)
Can be estimated. Here, M is the mass of the vehicle, and r is the wheel radius. [If the sum of the driving forces generated at the contact points of the driving wheels on the road surface is equal to the overall driving force MG (G is acceleration) of the vehicle, the wheel torque Tw is
Tw = M · G · r (5a)
Given in The acceleration G of the vehicle is obtained from the differential value of the wheel speed r · ω,
G = r · dω / dt (5b)
Therefore, the wheel torque is estimated as shown in Equation (5). Note that the estimated wheel torque value is not estimated from the wheel speed, but from the rotational speed of the rotating shaft of the drive system operatively connected to the drive wheels, such as the engine rotational speed, the transmission rotational speed, and the turbine rotational speed. It may be. When the rotational speed ne of the output shaft of the engine or motor of the driving device is used, the wheel rotational speed of the driving wheel is
ωe = ne x transmission (transmission) gear ratio x differential (differential gear) gear ratio (6)
Given by. When using the rotational speed no of the output shaft of the transmission,
ωo = no x differential gear ratio (7)
Given by. Then, the estimated value of the wheel rotational speed ω of the drive wheel in Expression (6) or (7) is substituted into Expression (5), and the estimated wheel torque value is calculated.

(Ii) Change in configuration of compensation component determination unit when vehicle height control is executed As already described, in the vehicle of this embodiment, the air suspension 38f, r, the vehicle height control device 50c, and the air suspension control device If necessary, the actual vehicle height is determined according to the selection of the vehicle height changeover switch even if the vehicle load or the number of passengers changes, that is, the weight of the vehicle body on the spring changes. The vehicle height control is performed to control the elastic modulus of the suspension so as to coincide with the target value of the vehicle (the vehicle height target value is automatically changed by a parameter representing the vehicle speed or other driving state). May be good). When such vehicle height control is executed, as easily understood, the vehicle height is determined by the balance between the elastic force of the suspension and the weight of the vehicle body on the spring (including the weight of the load / occupant). When the elastic modulus is changed to keep the vehicle height substantially constant, the vehicle body weight on the spring is changed. Further, when the setting of the vehicle height is changed, the elastic modulus of the suspension and the vehicle height change. Furthermore, in some vehicles, the damping factor of the suspension is changed along with the change of the elastic modulus by the vehicle height control. When the vehicle weight changes, the inertial moment of the vehicle body may fluctuate greatly due to the different weight distribution.

  Thus, in the situation where the vehicle height control is executed, among the parameters of the vehicle body vibration model shown in FIG. 3B or 3C, the elastic modulus, damping rate, vehicle weight, vehicle height, and moment of inertia of the suspension for vibration suppression control are included. However, if the moment of inertia changes, there is a possibility that the position of the center of gravity in the front-rear direction also changes. Ignore changes in the fore-and-aft direction.) In that case, the larger the change in these parameters, the larger the error of the model and the lower the accuracy of the compensation component of the vibration suppression control. Therefore, as already mentioned, in the present invention, the configuration of the compensation component determination unit is determined by detecting or estimating a parameter that changes during execution of the vehicle height control, and controlling the model change unit 52e based on the detected value. To reduce the influence of the decrease in accuracy of the compensation component of the vibration suppression control for the vehicle. Hereinafter, some aspects of the control processing of the model changing unit 52e will be described.

(First mode of control processing of model changing unit 52e)
In the first aspect of the control process of the model changing unit 52e, the current value of the parameter that may change when the vehicle height control is executed is acquired, and the compensation component in the compensation component determining unit is obtained. The parameter used for calculation is updated to the current value. That is, the components of the matrices A, B, and K in FIG. 3D (hereinafter referred to as “operator components”) are recalculated using the new parameter values.

Specifically, first, in the model changing unit 52e, first, the “error function” ε of the elastic modulus, damping rate, vehicle weight, vehicle height or moment of inertia of the suspension is calculated, and the value of ε is a predetermined value εo. Larger state ε> εo (8)
Is determined for a predetermined time τo or more. Here, the error function ε is used in the current actual value ξ (detected value or estimated value) and the vehicle body vibration model for each of the elastic modulus, damping rate, vehicle weight, vehicle height or moment of inertia of the suspension. Is a quantity representing a deviation from the value ξo, for example,
ε = (| ξ ² −ξo ² |) ^1/2 (8a)
(The values of the elastic modulus, damping rate, vehicle weight, vehicle height, and moment of inertia are substituted for ξ, and the corresponding model set values are substituted for ξo.)

  In calculating the error function ε, the current values of the elastic moduli kf and kr and the damping rates cf and cr of the suspension are given from, for example, the vehicle height controller 50c as described above.

The current value of the vehicle height h may also be given by the vehicle height control device 50c. In this regard, the vehicle height value used in the vibration suppression control device is the vehicle height value at the center of gravity, whereas the vehicle height control device can control the vehicle height separately for the front and rear wheels. In some cases, the vehicle height h at the center of gravity cannot be obtained directly. In such a case, the vehicle height h at the center of gravity is
h = Lf / (Lf + Lr). (hf−hr) + hr (9)
May be given by hf and hr are the vehicle height values of the front wheel and rear wheel axle positions, that is, the positions of the front wheel and rear wheel axles at the height of the center of gravity at the time of initial setting (usually when the vehicle height control is set to normal). This is a value obtained by adding the displacement amount of the vehicle height sensor at.

The current value of the vehicle weight is determined from the front and rear wheel loads Mf and Mr: M = Mf + Mr (10)
May be given by Here, the values of Mf and Mr may be used if a load sensor is provided for each wheel, but when such a sensor is not provided, the elastic modulus kf, kr and the vehicle height h From the displacement, it may be estimated using Hooke's law. Specifically, Mf and Mr are
Mf = kf / g · (Δf ^o −Δhf) (10a)
Mf = kf / g · (Δr ^o −Δhr) (10b)
Given by. Here, g is the gravitational acceleration, .DELTA.Hf, Hr is front or rear wheel axle initial set value of in vehicle height in ^hf o, the amount of change from ^{hr o Δhf = hf-hf o} ; Δhr = hr- hr ^o (10c)
(Δhf and Δhr correspond to readings of the vehicle height sensor). Δf ^o and Δr ^o are the amount of deflection of the suspension of the front and rear wheels in the initial setting state (the amount of displacement from the natural length of the spring),
ν · Mo · g = kf ^o · Δf ^o ; (1-ν) · Mo · g = k r ^o · Δr ^o (10d)
Given from the relationship. Here, Mo is the vehicle weight at the time of initial setting, ν, and (1-ν) is the load distribution ratio of the front wheels and the rear wheels.

Further, the current value I of the moment of inertia is the load Wf, Wr, detected by each of the load sensors 42f, 42r, 42t provided at the lower part of the front and rear seats and the trunk described in FIG. Using Wt,
I = Io + Wf · lmf ² + Wr · lmr ² + Wt · lmt ² (11)
Given by. Here, Io is a moment of inertia at the time of initial setting, and lmf, lmr, and lmt are distances in the front-rear direction from the load sensors 42f, 42r, and 42t to the center of gravity (see FIG. 4A). Strictly speaking, a change in the center of gravity accompanying a change in the load distribution of the vehicle body may be taken into consideration.

Thus, an error function ε is calculated for each of the above kf, kr, cf, cr, h, M, and I.
ε> εo (8)
Is determined to have continued for a predetermined time τo or more, using the new parameter values acquired or calculated as described above, that is, by updating the parameter values, the matrix A in FIG. The operator components of B and K are recalculated. The predetermined value εo may be arbitrarily determined by searching for a limit experimentally allowed to be affected by a decrease in accuracy of the compensation component. Then, the recalculated component is passed to the compensation component determination unit 52, and each component is updated.

  According to the above aspect, under the vehicle height control, the elastic modulus of the suspension is changed (that is, the target value of the vehicle weight or the vehicle height is changed), and the parameter for which the error function ε is increased is successively determined. Since it is updated, it is expected that a decrease in accuracy of the compensation component is suppressed. In the vehicle height control, the vehicle height is controlled to be kept substantially constant in the first place. Therefore, unless the vehicle height target value is changed, the vehicle height value h is not updated, and the parameters that can be updated are kf, kr, cf, cr, M, and I. In addition, the parameter error is always accompanied by a change in the elastic modulus of the suspension due to the vehicle height control, so the parameter and operator components are updated only by referring to the error function for the elastic modulus of the suspension. (For vehicles in which the elastic modulus cannot be variably controlled, the above update may be executed with reference to only the vehicle height error function). Furthermore, the update of the parameter and operator component may be executed immediately when the condition (8) is satisfied.

(Second aspect of control processing of model changing unit 52e)
In the second mode of the control process of the model changing unit 52e, first, an error function ε of a parameter that may change when the vehicle height control is executed is calculated as in the first mode. However, the initial setting values of the respective parameters are substituted for ξo in Expression (8). And any error function of parameters (including elastic modulus and vehicle height) is ε> ε1 (12)
Is satisfied, the output gain λout of the compensation component is set to 0, and the input of the compensation component to the adder a1 is cut off. Here, ε1 may be a predetermined value that is arbitrarily set. This process may be executed when the condition (12) is satisfied exceeds the predetermined time τ1. Further, after the input of the compensation component to the adder a1 is cut off, when the state where the condition (12) is not satisfied in the error function of all parameters continues for a predetermined time τ1, the output gain λout of the compensation component is the original. The value may be restored (the predetermined time τ1 may be arbitrarily set by experiment). According to this aspect, it is avoided that the compensation component having a reduced accuracy due to an error of any parameter is reflected in the wheel torque. Further, the configuration is simplified in that the configuration for recalculating the operator component of the model is not required as in the first aspect. In this case as well, when the error function increases, either the elastic modulus or the vehicle height changes, so that the compensation component is cut off and restored by referring to only the error function for any of them. Also good.

(Third Aspect of Control Processing of Model Changing Unit 52e)
In the third aspect of the control processing of the model changing unit 52e, after calculating the error function ε of the parameter that may change during the execution of the vehicle height control as in the second aspect, the error function The contribution of the compensation component is reduced by reducing the output gain λout of the compensation component according to the value of ε. Specifically, first, a correction coefficient Γ for the output gain λout is determined for each parameter as a function of the error function ε using a map as shown in FIG. By multiplying all products of coefficients Γ_total by the output gain λout, λout becomes
λout = Γ_total · λout ^o (13)
To be corrected. Here, λout ^o is an initial setting value of the output gain. Note that the value of Γ corresponding to each parameter may be reflected after a lapse of a certain time after the error function has changed in order to avoid a sudden change. Also in this case, when the error function increases, either the elastic modulus or the vehicle height changes, so that the compensation component may be cut off and restored with reference to only the error function for any of them. .

(Fourth Mode of Control Processing of Model Changing Unit 52e)
As a further aspect of the control process of the model changing unit 52e, the first and second aspects described above may be combined. FIG. 5 shows the control processing in that case in the form of a flowchart. Referring to the figure, in the process, first, as described above, the error function ε of each parameter is calculated with ξo as an initial set value (step 100). Thereafter, it is determined whether or not the condition (12) continues for a predetermined time τ1 or more (step 110). When the condition (12) continues for a predetermined time τ1 or more, the control gain is set to 0 (step 120). On the other hand, when the condition (12) does not continue for the predetermined time τ1 or more, the error function ε of each parameter is calculated using ξo as a model set value (step 130). Then, it is determined whether or not the condition (8) continues for the predetermined time τo or more (step 140). When the condition (8) continues for the predetermined time τo or more, the operator component is changed (step 150). When the control gain is set to 0, the control gain is restored when the condition (12) is not satisfied for a predetermined time τ1 or more (steps 105, 115, and 125). According to this configuration, as long as the actual vehicle state does not deviate significantly from the initial setting, vibration suppression control is executed by correcting the model parameters. When the actual vehicle state deviates greatly from the initial setting, the control is performed. The execution of vibration control is interrupted. Therefore, it is possible to execute the vibration suppression control within the allowable range even if the model parameters deviate from the initial settings.

  Although the above description has been made in relation to the embodiment of the present invention, many modifications and changes can be easily made by those skilled in the art, and the present invention is limited to the embodiment exemplified above. It will be apparent that the invention is not limited and applies to various devices without departing from the inventive concept.

  For example, although the wheel torque estimated value in the above embodiment is estimated from the wheel speed, the wheel torque estimated value may be estimated from parameters other than the wheel speed. Further, the vibration suppression control in the above embodiment is a vibration control of pitch bounce vibration using the theory of an optimal regulator assuming a sprung vibration model or a sprung / unsprung vibration model as a motion model. However, the concept of the present invention is that any vehicle body vibration can be controlled by using a vehicle body vibration motion model other than the one introduced here or by a control method other than the optimal regulator, as long as it uses wheel torque. The present invention is also applied to those that perform vibration, and such a case also belongs to the scope of the present invention. Furthermore, the present invention may be applied to a vehicle equipped with a suspension whose elastic modulus is variably controlled other than the air suspension.

FIG. 1 shows a schematic diagram of an automobile in which a preferred embodiment of a vibration damping control device according to the present invention is realized. (A) is a top view and (B) is a figure showing the inside from a side. FIG. 2 shows the internal configuration of the embodiment of the electronic control device of FIG. 1 in the form of a control block diagram. Various parameters other than those shown in the figure, such as engine temperature, may be input to the drive torque request value determination unit 51 and the control command determination unit 53. FIG. 3A is a diagram illustrating a state variable of vehicle body vibration that is suppressed in the operation of vibration suppression control according to a preferred embodiment of the present invention. FIG. 3B is a view for explaining a “sprung vibration model” which is one of the mechanical motion models of the vehicle body vibration assumed in the vibration damping control according to the preferred embodiment of the present invention, and FIG. It is a figure explaining an upper and unsprung vibration model. FIG. 3D is a diagram showing the configuration of the compensation component determination unit in the preferred embodiment of the present invention in the form of a control block diagram. FIG. 4A shows a model for calculating a change in the pitch inertia moment of the vehicle body. The dotted circle shows the tire. FIG. 4B shows an example of a map of the control gain correction coefficient Γ used in the third mode of processing of the model changing unit. A map of Γ may be prepared separately for each parameter. FIG. 5 shows a fourth aspect of the control process in the model changing unit of FIG. 2 in the form of a flowchart.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Vehicle body 12FL, FR, RL, RR ... Wheel 14 ... Accelerator pedal 20 ... Drive device 22 ... Diesel engine 22a ... Fuel device 30FL, FR, RL, RR ... Wheel speed sensor 32f, r ... Air suspension 34f, r ... Axle 36 ... Frame 37 ... Body bottom 38FL, FR, RL, RR ... Vehicle height sensor 40f, 40r ... Front and rear seats 40t ... Trunk bottom plate 42f, r, t ... Load sensor 50 ... Electronic control unit 50a ... Drive control unit 50b ... Braking Control device

Claims (7)

  In a vehicle having a suspension whose elastic modulus can be changed, vibration suppression control of the vehicle which suppresses the pitch bounce vibration of the vehicle by controlling the wheel torque generated at the contact point between the wheel and the road surface A compensation component determining unit that calculates a compensation component for compensating the wheel torque so as to reduce a vibration displacement of the vehicle body predicted using a vehicle body vibration model of the vehicle; and a vehicle height of the vehicle. A vehicle height value acquisition unit that acquires a value to be expressed, wherein the configuration of the compensation component determination unit is changed when a value representing the elastic modulus of the suspension or the vehicle height changes.   2. The apparatus according to claim 1, wherein the change in the configuration of the compensation component determination unit is performed by changing the suspension of the vehicle body vibration model in the compensation component determination unit based on a change in the vehicle height and the elastic modulus of the suspension. An apparatus comprising: changing at least some of the elastic modulus, vehicle weight or other parameters used in the vehicle body vibration model to their current actual values or estimated values thereof.   3. The apparatus according to claim 2, wherein the vehicle height value acquisition unit acquires a front wheel side vehicle height value at a front wheel of the vehicle and a rear wheel side vehicle height value at a rear wheel of the vehicle, and the compensation component determination unit. The vehicle height value at the center of gravity of the vehicle of the vehicle body vibration model in the compensation component determination unit based on the front wheel side vehicle height value and the rear wheel side vehicle height value is the current actual value or A device comprising changing to the estimated value.   4. The apparatus according to claim 2, wherein a change in the configuration of the compensation component determination unit is performed when the inertia moment of the vehicle body in the direction of displacement of the vehicle body vibration in the vehicle body vibration model in the compensation component determination unit is a current value. A device comprising changing to an actual value or an estimated value thereof.   5. The apparatus according to claim 1, wherein the change of the configuration of the compensation component determination unit is performed by changing the elastic modulus of the suspension, the vehicle weight, or other current values and initial values of at least some of the parameters used for the vehicle body vibration model. An apparatus comprising: stopping an output of the compensation component from the compensation component determination unit when an amount representing a deviation from a value deviates from a predetermined allowable range.   6. The apparatus according to claim 1, wherein a change in the configuration of the compensation component determination unit is performed between a vehicle height value acquired by the vehicle height acquisition unit and an initial value of a vehicle height used in the vehicle body vibration model. An apparatus comprising: stopping an output of the compensation component from the compensation component determination unit when an amount representing a deviation deviates from a predetermined allowable range.   7. The apparatus according to claim 1, wherein the change in the configuration of the compensation component determination unit is executed after a predetermined time has elapsed since the change in the value indicating the elastic modulus of the suspension or the vehicle height. A device characterized by that.

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