JP2011223691A - Vehicle control apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce degradation in a vibration suppression performance due to aliasing.SOLUTION: A vehicle control apparatus for controlling the drive control quantity of an engine as a drive source and a second motor/generator to suppress vibrations in a vehicle body is provided with a vibration-suppression-performance degradation-suppressing device (an input signal processing section 7o and an input signal determination section 7n) for reducing degradation in the vibration-suppression-performance against the vibration due to aliasing if the aliasing is generated in a signal regarding vibration information or a signal regarding a vibration-suppression-control compensation-quantity calculated based on the vibration information. The vibration-suppression-performance degradation-suppressing device is a filter for cutting a frequency higher than a Nyquist frequency.

Description

  The present invention relates to a vehicle control apparatus that performs vehicle system vibration control for suppressing vibration generated in a vehicle body.

  Conventionally, there is a technique called vehicle system vibration control that suppresses vibration generated in a vehicle body. As the vehicle system vibration control, one that suppresses vibration on the spring by increasing or decreasing the driving torque of the driving wheel (hereinafter referred to as “wheel torque”) is known. The target value of the wheel torque is set in consideration of the vibration suppression control compensation amount obtained based on the detection signal of a vibration information detection device (for example, a wheel speed sensor). For example, Patent Documents 1 and 2 below disclose ones that reduce pitch vibration and bounce vibration by fluctuations in the wheel torque. Here, the patent document 2 describes a technique for reducing the control gain of the compensation component of the wheel torque when the vibration amplitude such as pitch bounce vibration is equal to or greater than the predetermined amplitude for a predetermined time. Yes. Further, in Patent Document 3, in addition to the control gain reduction technique, noise frequency components (those generated by resonance, etc.) that cause vibration are removed from the detection signal such as wheel speed, and the wheel torque is adjusted. A technique is described in which a noise frequency component is not input to a drive torque control unit that controls drive torque of a power source.

  The following Patent Document 4 discloses vehicle system vibration control that suppresses unsprung vibration, and stops vibration suppression control when there is a possibility that it may be mistaken as a fluctuation in the rotational speed of a wheel due to aliasing noise. The technology is described. Patent Document 5 listed below describes a technique for providing an anti-aliasing filter that allows only a signal having a predetermined frequency or less of a cancellation error signal related to noise and cancellation noise to pass through in a vehicle interior noise control device. Yes.

JP 2009-040163 A JP 2009-127456 A JP 2008-231989 JP 2008-179196 A JP 2008-247342 A

  By the way, in the vibration suppression control amount calculation device that calculates the vibration suppression control compensation amount, if noise is superimposed on the input signal input from the vibration information detection device, so-called aliasing occurs depending on the sampling period. , Vibration information may be mistakenly recognized. For example, when wheel speed fluctuation is used as vibration information, the wheel speed fluctuation information is erroneously recognized as aliasing occurs. For this reason, in the conventional vehicle system vibration control, the estimation accuracy of the vibration state is lowered, which makes it difficult to set the compensation amount of the wheel torque with high accuracy, which may reduce the vibration damping performance against vibration. .

  Therefore, an object of the present invention is to provide a vehicle control apparatus that can improve the disadvantages of the conventional example and can suppress a decrease in vibration damping performance due to aliasing.

  In order to achieve the above object, the present invention provides a vehicle control device for controlling vibration generated in a vehicle body by controlling a drive control amount of a drive source, and a control calculated based on a signal related to vibration information or the vibration information. A feature of the present invention is to provide a vibration suppression performance deterioration suppressing device that suppresses a decrease in vibration suppression performance due to the aliasing when aliasing occurs in the signal related to the vibration control compensation amount.

  Here, it is preferable that the vibration suppression performance deterioration suppressing device includes a filter that allows only a predetermined frequency component of a signal related to the vibration information to pass therethrough and suppresses the occurrence of aliasing. The filter desirably cuts frequencies higher than the Nyquist frequency.

  Moreover, it is desirable that the vibration suppression performance deterioration suppressing device is configured to suppress the occurrence of aliasing by changing a sampling frequency related to the signal according to an environment where a vehicle is placed.

  Further, the vibration suppression performance deterioration suppressing device suppresses the occurrence of the aliasing, and interrupts the vibration suppression control for the vibration or suppresses the vibration suppression control compensation amount if the occurrence of the aliasing cannot be suppressed. It is desirable that

  Further, it is preferable that the vibration suppression performance deterioration suppressing device is configured to reduce a gain used for calculating the vibration suppression control compensation amount to 0 at the maximum.

  In order to achieve the above object, according to the present invention, in a vehicle control device that controls a drive control amount of a drive source to suppress vibration generated in a vehicle body, aliasing occurs in a signal related to vibration information. In addition, a vibration suppression control compensation amount for suppressing the vibration is obtained using a signal obtained by cutting a frequency higher than the Nyquist frequency of the signal, and the drive source is controlled based on the vibration suppression control compensation amount. It is said.

  The vehicle control device according to the present invention can suppress a decrease in the vibration suppression performance of the vehicle body due to aliasing. For example, by providing a vibration suppression performance deterioration suppressing device having a filter that suppresses the occurrence of aliasing, the vehicle control device performs a filtering process on a signal (input signal) related to vibration information, and performs aliasing of the input signal. Therefore, it is possible to calculate an appropriate amount of vibration suppression control compensation using an input signal through the filter. In addition, by providing a damping performance degradation suppressing device that suppresses the occurrence of aliasing by changing the sampling frequency related to the input signal or a signal (output signal) related to the damping control compensation amount calculated based on the input signal, If the environment in which the vehicle is located has a large road surface input, this vehicle control device can calculate an appropriate amount of vibration suppression control compensation at the current sampling frequency, and the environment has a large road surface input. If not, aliasing can be suppressed by changing the sampling frequency, and an appropriate damping control compensation amount can be calculated. In addition, by providing a damping performance deterioration suppressing device that interrupts damping control if the occurrence of aliasing cannot be suppressed or suppresses the damping control compensation amount to a low level, this vehicle control device can prevent erroneous damping due to aliasing. Vibration control can be suppressed.

FIG. 1 is a diagram illustrating an example of a vehicle to which a vehicle control device according to the present invention is applied. FIG. 2 is a diagram for explaining state variables of sprung vibration in the vehicle. FIG. 3 is a schematic diagram showing an example of a functional configuration of the vehicle control device according to the present invention in the form of a control block. FIG. 4 is a diagram for explaining an example of a dynamic motion model of sprung vibration assumed in the vehicle. FIG. 5 is a diagram for explaining another example of a dynamic motion model of sprung vibration assumed in a vehicle. FIG. 6 is a flowchart illustrating an operation for suppressing a reduction in vibration suppression performance in the vehicle control device according to the first embodiment. FIG. 7 is a schematic diagram illustrating an example of a functional configuration of the input signal processing unit according to the first embodiment in the form of a control block. FIG. 8 is a schematic diagram illustrating an example of a functional configuration of the input signal processing unit according to the second embodiment in the form of a control block. FIG. 9 is a flowchart for explaining the suppression operation of the vibration damping performance decrease in the vehicle control device of the second embodiment. FIG. 10 is a flowchart illustrating an operation for suppressing a decrease in vibration suppression performance in the vehicle control device according to the third embodiment. FIG. 11 is a flowchart for explaining another example of the suppression operation for suppressing the vibration damping performance in the vehicle control apparatus of the third 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 device according to the first embodiment performs vehicle system vibration control that suppresses vibrations generated in the vehicle body, and is prepared as a function of an electronic control device (ECU). In the vehicle system vibration control, the vibration state is estimated based on information for acquiring the vibration state (hereinafter referred to as “vibration information”), and a compensation amount for suppressing the vibration is obtained. The amount of compensation is a command value for a device for suppressing vibration (hereinafter referred to as “vibration suppressing device”).

  The vibration information is, for example, information indicating a driver's operation state, information indicating a vehicle state, external vehicle environment information, and the like, and is detected by a vibration information detection device (vibration information detection unit 8 described later). Information indicating the operation state of the driver includes an accelerator operation amount, a brake operation amount, a steering angle, and the like. The information indicating the vehicle state includes detection information by various sensors such as a wheel speed sensor and an acceleration sensor, control information in various control devices, control information of various actuators, and the like. The main information detected by the various sensors is the rotational speed (rotational speed) of the rotating body. For example, in addition to the wheel speed, the engine rotational speed, the motor rotational speed, the rotational speed of the output shaft of the transmission, etc. Is applicable. Further, the information indicating the vehicle state includes in-vehicle environment information, for example, information indicating the state of the driver. Further, the environment information outside the vehicle includes weather information, information on the road surface condition of the traveling road, and other information related to disturbance applied to the vehicle body.

  On the other hand, as a vibration suppression device, a power source, an automatic transmission, a braking device, a wheel steering device (controllable to a desired steering angle), and the like can be considered. In the case of a power source or an automatic transmission, a compensation amount for driving torque (driving force) is set. In the case of a braking device, a compensation amount of braking torque (braking force) is set. In the case of a steering device, a compensation amount for the steering angle of the wheel is set.

  Specifically, in a traveling vehicle, for example, when an external force or torque (that is, disturbance) is applied to a wheel due to road surface unevenness or the like, the external force or the like is transmitted to the vehicle body via the wheel and the suspension. For this reason, in this vehicle, vibrations of 1 to 4 Hz, more precisely about 1.5 Hz (hereinafter referred to as “sprung vibration”) are applied to the vehicle body via wheels and suspensions by input from the running road surface. Can occur). The sprung vibration includes components in the vertical direction (Z direction) of the vehicle (strictly speaking, the vehicle center of gravity Cg) shown in FIG. 2 (hereinafter referred to as “bounce vibration”) and a pitch direction centered on the vehicle center of gravity Cg. (Θ direction) component (hereinafter referred to as “pitch vibration”). When this sprung vibration is generated, at least one of bounce vibration and pitch vibration is generated. FIG. 2 exemplifies the vehicle posture during nose lift. In addition, when the power source that is the vehicle driving device is operated based on the driver's driving request and the like, and the wheel torque (wheel driving force) of the driving wheel fluctuates, the same sprung vibration (bouncing) At least one of vibration and pitch vibration) may occur. The vehicle drive device corresponds to the vibration suppression device described above. Here, the wheel torque (wheel driving force) of the drive wheels can be increased or decreased, and an automatic transmission or the like is included in addition to the power source.

  The vehicle control apparatus according to the first embodiment is exemplified as one that controls the wheel torque (wheel driving force) of the drive wheel by controlling the drive control amount of the vehicle drive apparatus, thereby suppressing the sprung vibration. . The drive control amount means, for example, the output torque if the vehicle drive device is a power source such as an engine. When the vehicle system vibration control (sprung vibration suppression control) is executed, the vehicle is controlled with respect to a travel control amount such as a required output torque of a power source or a required wheel torque of a drive wheel that is originally required for traveling. A damping control compensation amount for system vibration control (such as a compensation amount for damping the required output torque or a compensation amount for damping the required wheel torque) is added or subtracted.

  Here, examples of the vehicle to which the vehicle control device is applied include a vehicle that generates a driving force only with the power of a mechanical power source (an engine represented by a heat engine such as an internal combustion engine), and an electric power source (motor). , A vehicle (so-called electric vehicle) that generates a driving force only by the power of a generator that can be driven by power, or a motor / generator that can drive both powering and regeneration, and both a mechanical power source and an electric power source are installed A vehicle (so-called hybrid vehicle) is conceivable. In the first embodiment, the hybrid vehicle 100 shown in FIG. 1 will be described as an example.

The hybrid vehicle 100 illustrated here includes an engine 110, a power split mechanism 120 including a planetary gear mechanism that divides the engine torque output from the engine 110, and one of the engine torques divided by the power split mechanism 120. A first motor / generator 131 operable as a generator by a unit, and a second motor / generator 132 operable as an electric motor using electric power generated by the first motor / generator 131 and / or electric power of the battery 141, , And a power transmission mechanism 150 such as a differential gear that transmits the output torque of the power source to the drive wheels W _FL and W _FR (drive shafts Ds and Ds).

  The hybrid vehicle 100 includes an electronic control device (hereinafter referred to as “main ECU”) 10 that controls the operation of the entire vehicle and an electronic control device (hereinafter referred to as “engine ECU”) that controls the operation of the engine 110. .) 11 and an electronic control unit (hereinafter referred to as “motor generator ECU”) 12 for controlling the operation of the first motor / generator 131 and the second motor / generator 132 via the inverter 142. . The main ECU 10 is connected to the engine ECU 11 and the motor generator ECU 12, and can send and receive detection signals and control commands of various sensors between them. The vehicle control device according to the first embodiment functions as a vehicle system vibration control device by at least the main ECU 10, the engine ECU 11, and the motor generator ECU 12.

An example of the vehicle system vibration control operation by the vehicle control device of the first embodiment will be described in detail. In the vehicle system vibration control according to the first embodiment, a vibration suppression control compensation amount for suppressing sprung vibration (bounce vibration and pitch vibration) generated in the vehicle body is obtained, and an engine torque corresponding to the vibration suppression control compensation amount or / And the motor torque is output and generated in the vehicle body. In the first embodiment, a motion model of the sprung vibration of the vehicle body is constructed, and a state variable of the sprung vibration is calculated using the motion model. The state variable of the sprung vibration is a required vehicle driving torque Tddr (specifically, a value obtained by converting this to the required wheel torque Tw0 of the driving wheels W _FL and W _FR ) according to the driving request of the driver, Of the vehicle body when the wheel torque Tw (specifically estimated value thereof) is input to the motion model, and the rate of change dz / dt and dθ / dt thereof. In the first embodiment, the driver corrects the required vehicle driving torque Tddr, the required engine torque, the required motor torque, etc. so that the state variable converges to 0 or the minimum value, and outputs the vehicle driving device. (Drive torque, drive force) is adjusted so that the sprung vibration is suppressed.

  A control block diagram schematically showing the configuration of the vehicle control device is shown in FIG. The vehicle control device includes a driver request calculation unit 1 that calculates a required vehicle drive torque Tddr according to a driver's drive request, a vehicle drive torque calculation unit 2 that calculates a final required vehicle drive torque Tdr, an engine An engine control amount calculation unit 3 that calculates a control amount (required engine torque Ter and required engine speed Ner), an engine control unit 4 that controls the engine 110 based on the engine control amount, and a motor generator control amount (required motor) Based on a motor generator control amount calculation unit (hereinafter referred to as “MG control amount calculation unit”) 5 that calculates torques Tmg1r and Tmg2r) and a motor generator control amount (hereinafter referred to as “MG control amount”). And a motor generator control unit (hereinafter referred to as “MG control”) for controlling the second motor / generators 131 and 132. Parts "that.) Includes a 6, a. Further, the vehicle control apparatus includes a vibration suppression control amount calculation unit 7 for calculating a vibration suppression control compensation amount for suppressing the sprung vibration of the vehicle body, and a basis for estimating the vibration state of the sprung vibration. And a vibration information detection unit 8 for detecting the following information. In the hybrid vehicle 100 illustrated here, the engine control unit 4 and the MG control unit 6 are provided in the engine ECU 11 and the motor generator ECU 12, respectively, and the remaining various calculation units 1-3, 5, 7 and vibrations. An information detection unit 8 is provided in the main ECU 10.

  The driver request calculation unit 1 determines a requested vehicle drive torque Tddr by the driver based on drive request information associated with the driver's accelerator operation and information on the vehicle speed at that time. For example, the accelerator opening θa is used as the drive request information. Further, as information on the vehicle speed, information on the vehicle speed V, information on the wheel rotation angular velocity ω, information on the wheel speed Vw, information on the rotation angular velocity of the output shaft of a vehicle equipped with a transmission, and the like are used. Here, the wheel speed Vw (= r · ω) is used. “R” is the wheel radius. The required vehicle drive torque Tddr is a required value of the total output torque (hereinafter referred to as “total output torque”) of each power source that is output to satisfy the drive request of the driver.

  The vehicle drive torque calculation unit 2 obtains the final required value of the total output torque from each power source as the required vehicle drive torque Tdr based on the required vehicle drive torque Tddr by the driver. The requested vehicle driving torque Tdr is obtained by performing a predetermined correction on the requested vehicle driving torque Tddr by the driver. For example, at the time of braking, the braking torque (> 0) at that time is subtracted from the required vehicle driving torque Tddr. Further, in the vehicle driving torque calculation unit 2, the HV basic performance protection value is added to or subtracted from the requested vehicle driving torque Tddr by the driver. For this reason, the final required vehicle drive torque Tdr in this case is the total output torque of the power source that can satisfy all of the drive request of the driver and the HV basic performance.

  Here, the HV basic performance is a basic performance required for a hybrid vehicle. For example, drivability, performance against noise and vibration due to gear rattling, etc. (so-called sound vibration performance), battery balance, and battery balance. For example, the power balance between the engine 110 and the motor / generator (first and second motor / generators 131 and 132) for maintaining within a specified range, protection of components, and the like. The HV basic performance protection value is an HV basic performance compensation amount necessary for compensating the HV basic performance, and is set according to a difference between the current vehicle state and the HV basic performance.

  By the way, in the illustration of FIG. 3, an adder add1 is provided on the input side of the vehicle driving torque calculation unit 2 (that is, between the driver request calculation unit 1), and the requested vehicle drive by the driver is performed by this adder add1. The torque Tddr and a vibration suppression control compensation amount (vibration suppression torque Tdc described later) set by the vibration suppression control amount calculation unit 7 are added. For this reason, the vehicle driving torque calculation unit 2 illustrated in FIG. Therefore, the required vehicle drive torque Tdr in this example is the total output torque of the power source that not only satisfies the driver's drive request and HV basic performance, but also enables suppression of sprung vibration.

  The engine control amount calculation unit 3 obtains an engine control amount (required engine torque Ter and requested engine speed Ner) based on the requested vehicle drive torque Tddr by the driver. Here, since the information (wheel speed Vw) regarding the vehicle speed to the driver request calculation unit 1 is also input, the engine control amount is set in consideration of the information. Further, the engine control amount calculation unit 3 obtains the engine control amount in consideration of the gear ratio in the power transmission means such as the power split mechanism 120 and the power transmission mechanism 150, the remaining power storage amount of the battery 141, and the like. In the calculation, for example, the required engine torque Ter and the required engine speed Ner on the optimum fuel consumption line that satisfy the required vehicle drive torque Tddr may be obtained from the map in order to drive with good fuel efficiency. The requested engine torque Ter and the requested engine speed Ner are sent to the engine control unit 4. Further, the requested engine torque Ter is also sent to the MG control amount calculation unit 5.

  Here, in the illustration of FIG. 3, the added value of the required vehicle drive torque Tddr and the vibration suppression control torque Tdc in the adder add <b> 1 is input to the engine control amount calculation unit 3. For this reason, the engine control amount calculation unit 3 in this example calculates the engine control amount based on the added value. Therefore, the engine control amount takes into account the vibration suppression control compensation amount.

  The engine control unit 4 controls the throttle opening and the like of the engine 110 so as to be the received engine control amount (required engine torque Ter and requested engine speed Ner).

  In addition to the requested engine torque Ter, the requested vehicle driving torque Tdr is input from the vehicle driving torque computing unit 2 to the MG control amount computing unit 5. The MG control amount calculation unit 5 includes a subtraction rod 5a, and subtracts the requested engine torque Ter from the requested vehicle driving torque Tdr in the subtraction rod 5a. For example, in the engine travel mode in which the engine 110 travels only with the power of the engine 110, the subtraction value is 0, and the required motor torque Tmg1r is set so that neither the power running drive nor the regenerative drive is performed in both the first and second motor generators 131 and 132. , Tmg2r is set to zero. On the other hand, in the so-called EV travel mode in which the vehicle travels only with the power of the motor / generator (here, the second motor / generator 132), the required engine torque Ter is 0. Therefore, for example, during acceleration, the required motor torque Tmg2r. = Tdr, and the required motor torque Tmg1r becomes zero. Also, in the hybrid travel mode in which the engine 110 and the motor / generator (second motor / generator 132) travel with power, for example, if the subtraction value (= Tdr-Ter) is positive, the second motor / generator 132 is powered. The subtraction value is set to the required motor torque Tmg2r so as to be driven. If the subtraction value is negative, the subtraction value is set to the required motor torque Tmg1r so that the first motor generator 131 is driven to regenerate. The requested motor torques Tmg1r and Tmg2r are sent to the MG control unit 6. In this example, the calculated MG control amount (required motor torques Tmg1, Tmg2) takes into account the vibration suppression control compensation amount.

  The MG control unit 6 controls the first and second motor generators 131 and 132 so that the received MG control amount (required motor torque Tmg1, Tmg2) is obtained.

The vibration suppression control amount calculation unit 7 obtains a vibration suppression control compensation amount for suppressing sprung vibration generated in the vehicle body by using a well-known method in this technical field. For example, here, the state variable of the sprung vibration is calculated by the motion model of the sprung vibration, and the wheel torque compensation value Twc of the drive wheels W _FL and W _FR that converges the state variable to 0 or the minimum value is obtained. Is replaced with a vibration suppression control torque Tdc (a vibration suppression control compensation amount). Specifically, the vibration suppression control amount calculation unit 7 is provided with a feedforward control unit 7a and a feedback control unit 7b.

The feedforward control unit 7a has a so-called optimum regulator configuration, and a wheel torque conversion unit 7c that converts a requested vehicle driving torque Tddr by the driver into a requested wheel torque Tw0 and a spring based on the requested wheel torque Tw0. A motion model unit 7d for sprung vibration for obtaining a state variable of upper vibration, and an FF secondary regulator unit 7e for obtaining a correction amount of the required wheel torque Tw0 for converging the state variable to 0 or a minimum value. ing. The required wheel torque Tw0 is a required value of the wheel torque of the drive wheels W _FL and W _FR according to the driver's drive request. In the motion model unit 7d, a response of the state variable of the vehicle body to the input requested wheel torque Tw0 is calculated. On the other hand, the FF secondary regulator unit 7e calculates an FF system damping torque compensation amount U · FF that converges the state variable to 0 or the minimum value based on a predetermined gain K described later. The FF system damping torque compensation amount U · FF is a correction amount of the requested wheel torque Tw0 by the driver, and a feedforward control amount (FF control amount) of damping control set in the feedforward control system. That is, it means a vibration suppression control compensation amount of the vehicle body in the feedforward control. The FF control amount is based on the vehicle drive torque Tddr requested by the driver.

The feedback control unit 7b also has a so-called optimum regulator configuration. The feedback control section 7b is driven wheels _{W FL,} a wheel torque estimating unit 7f for estimating the wheel torque estimated value Tw of _{W FR,} the motion model unit 7d of the combined feed-forward control unit 7a, FB secondary regulator unit 7g And. In the feedback control unit 7b, the wheel torque estimation unit 7f calculates a wheel torque estimated value Tw of the drive wheels W _FL and W _FR based on the wheel rotation angular velocity ω or the wheel speed Vw as described later, and this wheel torque estimation. The value Tw is input to the motion model unit 7d as a disturbance input. In the motion model unit 7d, a response of the state variable of the vehicle body to the input wheel torque estimation value Tw is calculated. On the other hand, the FB secondary regulator unit 7g calculates an FB system damping torque compensation amount U · FB that converges the state variable to 0 or the minimum value based on a predetermined gain K described later. The FB system damping torque compensation amount U · FB is a correction amount of the requested wheel torque Tw0 by the driver, and is a feedback control amount (FB control amount) of damping control set in the feedback control system, that is, This refers to the amount of vibration suppression control compensation of the vehicle body in feedback control. The FB control amount corresponds to the fluctuation of the wheel rotational angular velocity ω or the wheel speed Vw based on the external force or torque (disturbance) by the input from the road surface to the wheels W _FL , W _FR , W _RL , W _RR . In the first embodiment, the feedforward control unit 7a and the feedback control unit 7b share the motion model unit 7d. However, the motion model unit may be prepared individually.

  As described above, the FF system damping torque compensation amount U · FF is set based on the driver's accelerator opening θa (operating state of the driver). Further, the FB system damping torque compensation amount U · FB is set based on the wheel rotational angular velocity ω or the wheel velocity Vw (vehicle state). As described above, the vibration generated in the vehicle body is detected by information indicating the operation state of the driver, information indicating the vehicle state, external environment information, and the like. Therefore, in this vibration suppression control amount calculation unit 7, in order to estimate the vibration state with higher accuracy, the feedforward control unit 7a is provided with an FF control change unit 7h and an FF control gain setting unit 7i, and a feedback control unit. An FB control changing unit 7j and an FB control gain setting unit 7k are provided in 7b. The FF control changing unit 7h and the FF control gain setting unit 7i are for changing (correcting) the FF system damping torque compensation amount U / FF further according to the vehicle state or the like. On the other hand, the FB control changing unit 7j and the FB control gain setting unit 7k are for changing (correcting) the FB system damping torque compensation amounts U and FB according to the operation state of the driver.

  The FF control changing unit 7h multiplies the FF system damping torque compensation amount U · FF input from the FF secondary regulator unit 7e by the FF control gain K · FF, and uses the FF system damping torque compensation amount U · FF. Change (correct) the vehicle according to the vehicle condition. The FF control gain K · FF is set by the FF control gain setting unit 7i according to the vehicle state and the like.

  On the other hand, the FB control changing unit 7j multiplies the FB system damping torque compensation amount U · FB input from the FB secondary regulator unit 7g by the FB control gain K · FB, and the FB system damping torque compensation amount U · FB. FB is changed (corrected) according to the operation state of the driver. The FB control gain K · FB is set by the FB control gain setting unit 7k according to the operation state of the driver.

In the vibration suppression control amount calculation unit 7, the FF system damping torque compensation amount U · FF and the FB system damping torque compensation amount U · FB are transmitted to the adder 7l. In the adder 7l, the FF vibration damping torque compensation amount U · FF and the FB vibration damping torque compensation amount U · FB are added. The added value is a wheel torque compensation value Twc for vehicle system vibration control. The wheel torque compensation value Twc is a vibration suppression control compensation amount for the drive wheels W _FL and W _FR . The wheel torque compensation value Twc is input to the drive torque conversion unit 7m, and is converted into a unit of the required torque (drive torque) of the vehicle drive device by the drive torque conversion unit 7m. Here, it converts into the unit of the output torque of each motive power source. In the vibration suppression control amount calculation unit 7, the converted value becomes the vibration suppression control torque Tdc as the final vibration suppression control compensation amount.

  In this example, since the vibration suppression control torque Tdc is input to the adder add1, the sprung vibration is suppressed using both the engine torque and the motor torque. On the other hand, when suppressing the sprung vibration only with the engine torque, an adder is provided on the engine control amount calculation unit 3 or on the input side thereof, and the vehicle drive torque calculation unit 2 includes an element related to the vibration suppression control torque Tdc. It is only necessary to prevent input. In this case, the engine control amount calculation unit 3 calculates the engine control amount based on the added value of the requested vehicle drive torque Tddr and the vibration suppression control torque Tdc. Further, when suppressing the sprung vibration only by the motor torque, the MG control amount calculation unit 5 or its input side (that is, between the vehicle drive torque calculation unit 2) or the output side (that is, the MG control unit 6). It is only necessary that an adder is provided between the vehicle driving torque calculation unit 2 and the engine control amount calculation unit 3 so that elements relating to the vibration suppression control torque Tdc are not input. Thereby, in this case, the vibration suppression control torque Tdc is output only by the motor torque.

  As described above, in this vehicle system vibration control, a dynamic motion model of sprung vibration (bounce vibration and pitch vibration) of the vehicle body is assumed, and the requested wheel torque Tw0 and the estimated wheel torque Tw (disturbance) by the driver are assumed. Is formed as a state equation of state variables in the bounce direction and the pitch direction. In this vehicle system vibration control, the input (torque value) at which the bounce and pitch state variables converge to 0 is determined from the state equation using the theory of the optimal regulator, and the torque value is subjected to vibration suppression control. The compensation amount (vibration control torque Tdc) is used.

  As such a dynamic motion model, as shown in FIG. 4, the vehicle body is regarded as a rigid body S having a mass M and a moment of inertia I. An example supported by a rear wheel suspension at a rate cr (vehicle body sprung vibration model) is illustrated. In this case, the motion equation in the bounce direction and the motion equation in the pitch direction at the vehicle center of gravity Cg can be expressed as the following equations 1 and 2, respectively.

In the formulas 1 and 2, Lf and Lr represent the distance from the vehicle center of gravity Cg to the front wheel axis and the distance to the rear wheel axis, respectively, and r represents the wheel radius. Further, h represents the distance from the road surface to the vehicle center of gravity Cg. In Equation 1, the first and second terms are components of force from the front wheel shaft, and the third and fourth terms are components of force from the rear wheel shaft. In Equation 2, the first term is the moment component of the force from the front wheel shaft, and the second term is the moment component of the force from the rear wheel shaft. The third term of Equation 2 is the moment component of the force that the wheel torque T (= Tw0 + Tw) generated in the drive wheels W _FL and W _FR gives around the vehicle center of gravity Cg.

  These equations 1 and 2 are the state equations (linear system) as shown in equation 3 below, with the vehicle body displacements z and θ and their rate of change dz / dt and dθ / dt as the state variable vector X (t). Can be rewritten.

  In Equation 3, X (t), A, and B are as follows.

The elements a1 to a4 and b1 to b4 of the matrix A are given by combining the coefficients of z, θ, dz / dt, and dθ / dt in the above equations 1 and 2, 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 becomes.

  In addition, u (t) in this equation 3 is shown in the following equation 5 and is an input of the linear system represented by this equation 3.

  Therefore, from the above equation 2, the element p1 of the matrix B can be expressed by the following equation 6.

  If u (t) is set as in the following formula 7 in the above formula 3 (state equation), this formula 3 can be expressed as in the following formula 8.

Therefore, 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) When the differential equation (formula 8) of the state variable vector X (t) is solved, the gain K for converging X (t), that is, the displacement in the bounce direction and the pitch direction and the time change rate thereof to 0 is obtained. If determined, a torque value u (t) that suppresses sprung vibration is determined.

  The gain K can be determined using a so-called optimal regulator theory. According to this theory, when the value of the quadratic evaluation function J (integral range is 0 to ∞) of the following equation 9 is minimized, X (t) is stable in the state equation (equation 3). It is known that the matrix K that converges and minimizes the evaluation function J is given as shown in Equation 10 below.

  Here, P is a solution of the Riccati equation (Equation 11). This Riccati equation can be solved by any method known in the field of linear systems, which determines the gain K.

  Note that Q and R in the evaluation function J and Riccati equation are a semi-positive definite symmetric matrix and a positive definite symmetric matrix, which are arbitrarily set, respectively, and are weight matrices of the evaluation function J determined by the system designer. For example, in the case of the motion model here, Q and R are set as follows, and in Equation 9 above, specific ones of the components of the state variable vector X (t) (for example, dz / dt, dθ / dt) ) Is set to be larger than the norm of other components (for example, z and θ), the component having a larger norm is relatively stably converged. Further, when the value of the Q component is increased, the transient characteristics are emphasized, that is, the value of the state variable vector X (t) quickly converges to a stable value, and when the value of R is increased, the energy consumption is reduced.

  In the vehicle system vibration control of the first embodiment, as shown in FIG. 3, the state variable vector X (t) is calculated by solving the differential equation of Equation 3 using the torque input value in the motion model unit 7d. . Subsequently, in the FF secondary regulator unit 7e and the FB secondary regulator unit 7g, U (t) is obtained by multiplying the gain K by the state variable vector X (t) that is the output of the motion model unit 7d. The gain K is determined to converge the state variable vector X (t) to 0 or the minimum value. Further, U (t) obtained by the FF secondary regulator unit 7e and the FB secondary regulator unit 7g is the FF system damping torque compensation amount U · FF and the FB system damping torque compensation amount U · FB, respectively. It is. This multiplication value U (t) indicates a positive or negative value depending on the vibration direction of the sprung vibration. Further, here, the FF control changing unit 7h changes (corrects) the FF system damping torque compensation amount U / FF, and the FB control changing unit 7j changes (corrects) the FB system damping torque compensation amount U / FB. ) Subsequently, the wheel torque compensation value Twc based on the changed (corrected) FF system damping torque compensation amount U · FF and the FB system damping torque compensation amount U · FB is converted into the damping control torque Tdc by the drive torque conversion unit 7m. Converted to The damping control torque Tdc, which is the final damping control compensation amount, is added to the requested vehicle driving torque Tddr by the driver in the adder add1. Such a system is a resonant system, and for a given input, the value of the state variable vector X (t) is substantially only a component of the natural frequency of the system. Accordingly, by configuring the converted value of U (t) to be added to the required vehicle drive torque Tddr (substantially subtracted when U (t) is negative), the required vehicle drive torque Tddr The component of the natural frequency of the system, that is, the component causing the sprung vibration in the vehicle body is corrected, and the sprung vibration is suppressed. When the component of the natural frequency of the system disappears in the required torque given by the driver, the component of the natural frequency of the system in the requested vehicle drive torque command input by the driver to the vehicle drive device is -U ( t) only, and the vibration due to Tw (disturbance) converges.

  Here, as the dynamic motion model in the bounce direction and the pitch direction of the vehicle body in the above example, for example, as shown in FIG. 5, in addition to the configuration of FIG. 4, the spring elasticity of the tires of the front wheels and the rear wheels is considered. The model (a sprung / lower vibration model of the vehicle body) may be employed. Assuming that the tires of the front wheels and the rear wheels have the elastic moduli ktf and ktr, respectively, the motion equation in the bounce direction and the motion equation in the pitch direction of the vehicle center of gravity Cg are as follows. It can represent like Formula 13a-13d.

  In these equations, 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 13a to 13d constitute a state equation like the above Equation 3 using z, θ, xf, and xr and their time differential values as state variable vectors, as in FIG. , 8 rows and 8 columns, and matrix B is 8 rows and 1 column.) According to the theory of the optimal regulator, the gain matrix K that converges the state variable vector to 0 can be determined. The actual sprung mass damping control in this case is the same as in the case of FIG.

Furthermore, the feedback control unit 7b may be configured to actually detect the wheel torque input as a disturbance by, for example, providing each wheel _WFL , _WFR , _WRL , _WRR with a torque sensor. Here, the estimation is made based on other values detected by the vibration information detector 8 during traveling. In this example, the wheel speed sensors of the drive wheels W _FL and W _FR are used as the vibration information detection unit 8, and the wheel rotation angular speed ω is detected by the wheel speed sensor. For example, the wheel torque estimating unit 7f can estimate (calculate) the wheel torque estimated value Tw by the following formula 14 using the time differentiation of the wheel rotation angular velocity ω.

Here, assuming that the sum of the driving forces generated at the ground contact points on the road surface of the driving wheels W _FL and W _FR is equal to the driving force M · G (G: vehicle longitudinal acceleration) of the entire vehicle, the estimated wheel torque value Tw Is given by Equation 15 below.

  Further, the vehicle longitudinal acceleration G of the hybrid vehicle 100 is given by the following equation 16 from the differential value of the wheel rotation angular velocity ω.

  It can be seen from these formulas 15 and 16 that the wheel torque estimated value Tw can be estimated by the above formula 14.

Thus, in this vehicle control device, the vibration state is estimated based on the vibration information detected by the vibration information detector 8. In the above specific example, the wheel torque estimated value Tw obtained based on the wheel rotation angular velocity ω, which is vibration information, indicates wheel torque fluctuation due to vibration and represents a vibration state. Here, the wheel speed Vw (= r · ω) obtained by multiplying the wheel rotation angular speed ω by the wheel radius r may be input to the vibration suppression control amount calculation unit 7 as vibration information. In FIG. Such a form is illustrated. Therefore, in the illustration, the wheel speed Vw (= r · ω) is calculated by the braking control device 9 to which the wheel rotation angular speed ω is input, and the wheel speed Vw is input to the vibration suppression control amount calculation unit 7. The estimated wheel torque value Tw corresponds to the wheel rotational angular speed fluctuation or wheel speed fluctuation. Therefore, the wheel rotation angular speed fluctuation and the wheel speed fluctuation also represent a vibration state. Further, although the wheel rotation angular velocity ω is exemplified as that of the front wheels W _FL and W _FR as driving wheels, it may be that of the rear wheels W _RL and W _RR as driven wheels.

  By the way, when noise is superimposed on the input signal to the vibration suppression control amount calculation unit 7, so-called aliasing may occur due to the noise exceeding the sampling limit frequency depending on the sampling period. As a result, noise superimposed on the input signal changes to a fake frequency including 1.5 Hz, and vibration information may be erroneously recognized. There is a risk of causing. For example, in the above example, there is a possibility that the wheel rotation angular speed fluctuation or the wheel speed fluctuation obtained based on the input signal of the wheel rotation angular speed ω or the wheel speed Vw may be erroneously recognized. There is a concern that the estimation accuracy of the value Tw) may be reduced. Therefore, at that time, it is difficult to set the vibration suppression control compensation amount to an amount suitable for vibration suppression, and there is a possibility that the vibration suppression performance against vibration is reduced. As a more specific example, the wheel speed Vw is calculated at a calculation period of 6 ms in a brake ECU (not shown) of the braking control device 9, and a signal of the wheel speed Vw is transmitted to the other ECU (main The transmission cycle for transmission to the ECU 10) is 12 ms. In this case, if wheel speed noise (85 Hz) with a sampling limit frequency of 6 ms is on the vehicle, for example, the aliasing frequency fa = 85− (1 / 0.012) ≈1.66 (Hz), which is a fake frequency. . The aliasing frequency fa is derived by Expression 17 below. “F0” is the frequency of the input signal (source signal), and “fs” is the sampling frequency. Here, since f0 = 85 Hz and fs = 1 / 0.012≈83.33 Hz, “fs ≦ f0 ≦ 3fs / 2” is derived from the third equation from the top. Therefore, in this case, vehicle system vibration control cannot be executed correctly by superimposing a frequency including fake 1.5 Hz on the input signal of the wheel speed Vw input to the vibration suppression control amount calculation unit 7.

  Therefore, in the vehicle control device according to the first embodiment, a damping performance reduction suppressing device that suppresses a reduction in the damping performance of the vehicle body against vibration due to aliasing is provided.

  In the first embodiment, it is determined that there is a possibility of occurrence of aliasing when an input signal to the vibration suppression control amount calculation unit 7 satisfies a predetermined condition. In this case, when the determination is made, a predetermined process is performed on the input signal to avoid the occurrence of the aliasing phenomenon. The aliasing phenomenon refers to a phenomenon in which an original signal (source signal) cannot be correctly reproduced from sampling information when a certain signal is sampled.

  The vibration suppression control amount calculation unit 7 is provided with an input signal determination unit 7n that determines whether or not the input signal satisfies a predetermined condition. The input signal determination unit 7n receives a detection signal from the vibration information detection unit 8 or a signal based on the detection signal. In the example of FIG. 3, the wheel speed Vw (= r · ω) calculated based on the wheel rotation angular speed ω of the vibration information detection unit 8 is input, and the input signal is the rotation speed (rotation speed) of the rotating body described above. That is, it may be the wheel rotational angular velocity ω, the engine rotational speed, the motor rotational speed, the rotational speed of the output shaft of the transmission, and the like.

  The input signal determination unit 7n determines that there is a possibility of aliasing when the input signal is in a predetermined region. If the input signal is the rotational speed (rotation speed) of the rotating body, the input signal determination unit 7n determines that there is a possibility of occurrence of aliasing when the input signal is in a predetermined rotation region. For example, when the determination is made using the n-order component of the rotation speed, the predetermined rotation area is the rotation speed when the n-order component is in the predetermined area at a predetermined sampling frequency (a certain rotation). It may be a number or a rotation speed with a width. The n-order component represents one rotation of the rotating body as one cycle and the number of vibrations per cycle, that is, the vibration frequency. Here, the predetermined sampling frequency is the sampling frequency when the input signal (source signal) is sampled for the first time, and the lowest sampling when there is downsampling due to resampling or transmission period at the second and subsequent samplings. It is a frequency. Here, when a sampling frequency corresponds to at least one of the two, it corresponds to a predetermined sampling frequency. On the other hand, the predetermined region is when the fake frequency in aliasing due to the sampling period is at a low frequency (around 1.5 Hz). That is, the input signal determination unit 7n, for example, when the false frequency due to the n-order component of the input rotational speed of the rotating body becomes a low frequency (near 1.5 Hz) at the sampling frequency at the time of initial sampling, It is determined that there is a possibility that the rotational speed of the rotating body is in a predetermined rotational region where aliasing may occur. In this example, sprung mass damping control is taken as an example, so that it is around 1.5 Hz. However, in the case of unsprung vibration damping control, the aliasing frequency fa is around 14 Hz, and the vibration damping control of a drive system such as a transmission is performed. In some cases, aliasing may occur at around 8 Hz.

  The input signal determination unit 7n may determine that there is a possibility of occurrence of aliasing when the rotating body enters such a predetermined rotating state. Here, as shown in the flowchart of FIG. When such a predetermined rotation state continues for a certain time (for example, several milliseconds s, several seconds), it is determined that there is a possibility of occurrence of aliasing.

  The input signal determination unit 7n determines whether or not the rotating body related to the input signal has been in a predetermined rotation state for a certain period of time (step ST1). Then, the input signal determination unit 7n determines that there is no possibility of occurrence of aliasing if the predetermined rotation state does not continue for a certain period of time, and uses the raw input signal (raw value) as the input source signal. Setting of the vibration suppression control compensation amount is executed (step ST2). On the other hand, the input signal determination unit 7n determines that there is a possibility of occurrence of aliasing if the predetermined rotation state continues for a certain period of time, and applies a predetermined filter process to the input source signal (input signal). Is used to set the damping control compensation amount (step ST3).

  The vibration suppression control amount calculation unit 7 is provided with an input signal processing unit 7o that performs predetermined processing on the input signal based on the determination result input from the input signal determination unit 7n. As shown in FIG. 7, the input signal processing unit 7o includes a predetermined filter 71o and a signal selection bar 72o that selects a signal according to the determination result of the input signal determination unit 7n. The predetermined filter 71o is a low-pass filter (LPF) or a high-cut filter (HCF) that passes only a low-frequency component of the input signal. The cut-off frequency of the filter 71o is set to, for example, a Nyquist frequency (a frequency that is ½ of the sampling frequency fs) so as to suppress the occurrence of aliasing. The signal selection rod 72o is, for example, a changeover switch circuit, and when the input signal determination unit 7n obtains the determination result of step ST2, the switching of the contact is performed so that the raw input signal is input to the wheel torque estimation unit 7f. If the determination result of step ST3 is obtained, the contact is switched so that the input signal through the filter 71o is input to the wheel torque estimating unit 7f.

  Thus, in this vehicle control device, when there is no possibility of occurrence of aliasing, the wheel torque fluctuation (wheel torque estimated value Tw) can be accurately estimated using the raw input signal. For this reason, in this case, it is possible to set an appropriate amount of vibration suppression control compensation and execute appropriate vehicle system vibration control, so that the sprung vibration of the vehicle body can be suppressed with high accuracy. On the other hand, in this vehicle control device, when there is a possibility of occurrence of aliasing, the wheel torque fluctuation is estimated using the input signal after the filter processing. Therefore, in this case, the occurrence of aliasing can be avoided, so that the wheel torque fluctuation can be estimated with high accuracy. Therefore, in this vehicle control device, even when there is a possibility of occurrence of such aliasing, it is possible to suppress the on-spring vibration of the vehicle body with high accuracy by appropriate vehicle system vibration control. Here, the input signal determination unit 7n and the input signal processing unit 7o function as a vibration suppression performance deterioration suppressing device.

  Here, in the example of FIG. 3, the wheel speed Vw (= r · ω) is also input to the driver request calculation unit 1. For this reason, the above determination is also performed for the rotating body (wheel) related to the input signal, and if there is a possibility of occurrence of aliasing, the same filtering process may be performed on the input signal.

  In the first embodiment, the number of rotations (rotation speed) of the rotating body is exemplified as the vibration information input to the vibration suppression control amount calculation unit 7. However, the vibration information may be any information as long as vibration can be grasped. It may be a thing. For example, it is possible to use vehicle acceleration information such as vehicle longitudinal acceleration and vehicle lateral acceleration. When this vehicle acceleration information is input as vibration information, the input signal determination unit 7n receives aliasing when a fake frequency due to noise of the acceleration sensor becomes a low frequency (near 1.5 Hz) at a predetermined sampling frequency. It is determined that there is a risk of occurrence of The predetermined sampling frequency is the same as that shown above. In addition, as vibration information, if the vibration accompanying the input from the road can be recognized in advance as the road information, the vehicle position information for specifying the road information together with the map information or the like can be used. is there. The own vehicle position information is a detection signal of a GPS (global positioning system), a detection signal of a car navigation system, or the like. Further, the vibration suppression control amount calculation unit 7 may be input with a plurality of pieces of the above-described various vibration information such as the rotational speed of the rotating body and vehicle acceleration information.

  When a plurality of types of vibration information such as the number of rotations of the rotating body and vehicle acceleration information can be input, it is preferable to determine whether there is a possibility of occurrence of aliasing in each of them. In this case, when the determination result of step ST3 is obtained, it is preferable to perform the above-described filter processing on all of them in order to improve the estimation accuracy of the wheel torque fluctuation, but at least one of them is preferable. It is possible to improve the estimation accuracy of the wheel torque fluctuation only by performing the filtering process on one of them.

  Here, in the first embodiment, it is determined that there is a possibility of occurrence of aliasing when the predetermined rotation state continues for a certain time. Alternatively, it may be determined that there is a possibility of occurrence of aliasing when the predetermined rotation state is determined a predetermined number of times within a predetermined time.

  In addition, the input signal determination unit 7n determines that there is a possibility of occurrence of aliasing when the input signal is in a predetermined rotation region, and performs filtering on the input signal. Filter processing may be performed on the input signal.

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

  Although the filtering process performed in the first embodiment described above can avoid the occurrence of aliasing, there is a risk that the signal may be delayed as it passes through the filter 71o. The accuracy of the control compensation amount may be reduced.

  Therefore, in the second embodiment, the vibration suppression control amount calculation unit 7 may be set so that an input signal is input to the wheel torque estimation unit 7f without going through the input signal processing unit 7o. If there is a possibility of occurrence of aliasing, a command is sent to the FB control gain setting unit 7k, and the FB control gain K · FB is obtained so as to obtain an accurate vibration suppression control compensation amount by avoiding the influence of aliasing. May be reduced. At that time, the FF control gain K · FF may be similarly reduced in the FF control gain setting unit 7i. In this case, in the vehicle body control apparatus, the compensation amount based on the vibration estimation result without delay caused by the raw input signal is adjusted by the control gain, so that an appropriate vibration suppression control compensation amount can be set. Therefore, the vehicle body control device can suppress the sprung vibration of the vehicle body with high accuracy by appropriate vehicle body vibration control. In this case, it is determined that there is a possibility of occurrence of aliasing when the input signal is in a predetermined rotation region, and the control gain (FB control gain K · FB, FF control gain K · FF) is changed. The control gain may be changed regardless of the rotation region.

  In order to avoid the delay due to the filter processing, the input signal determination unit 7n and the input signal processing unit 7o are set as follows, and when there is a possibility of occurrence of an aliasing phenomenon, vibration information of another rotating body You may cope with it by switching to the input signal based on.

As shown in FIG. 8, the input signal processing unit 7 o includes a signal selection rod 73 o that can switch input signals based on vibration information of a plurality of types of rotating bodies. For example, here, it is assumed that a wheel speed sensor for the front wheels W _FL and W _FR, a wheel speed sensor for the rear wheels W _RL and W _RR , and a motor rotation sensor are prepared as the vibration information detection unit 8. In this case, the signal selection噐73o is set to allow the front wheels _{W FL,} switching of signals between the wheel speed Vwr and motor speed Nmg of _W wheel speed Vwf and the rear wheels _W RL of _{FR, W RR.} For example, the wheel speed Vwf of the front wheels W _FL and W _FR is mainly used, and when the wheel speed Vwf cannot be used due to the possibility of occurrence of aliasing, the wheel speed Vwr of the rear wheels W _RL and W _RR and the motor rotation speed Nmg are used. Let me switch.

As shown in the flowchart of FIG. 9, the input signal determination unit 7n determines whether or not the front wheels W _FL and W _FR are continuously in a predetermined rotation state for a certain period of time as in the previous example ( Step ST11). Then, the input signal determination unit 7n, if the predetermined rotation state has not continued a predetermined time, the front wheels _{W FL,} it is determined that no possibility of aliasing occurs in _{W FR,} the wheel speed Vwf of front wheels _{W FL, W FR} Is set using the input signal (raw value) (step ST12).

On the other hand, the input signal determination unit 7n are the front wheels _{W FL,} if the _{W FR} is predetermined rotation state if subsequently a certain time, it is determined that there is a risk of the front wheels _{W FL,} the _{W FR} aliasing occurs, the rear wheel W It is similarly determined whether or not _RL and _WRR are in a predetermined rotation state for a predetermined time (step ST13). Then, the input signal determination unit 7n, if the predetermined rotation state has not continued a predetermined time, the rear wheels W _RL, and determines that there is no risk of aliasing occurs in W _RR, rear wheel W _RL, wheels W _RR Using the input signal (raw value) of the speed Vwr, the vibration suppression control compensation amount is set (step ST14).

In contrast, the input signal determination unit 7n are the rear wheels W _RL, if also in W _RR if followed predetermined rotation state a predetermined time, determines that there is a possibility of aliasing occurrence rear wheel W _RL, even W _RR Thus, for example, it is determined whether or not the second motor / generator (MG2) 132 continues to be in a predetermined rotation state for a certain period of time (step ST15). Then, if the predetermined rotation state does not continue for a predetermined time, the input signal determination unit 7n determines that the second motor / generator 132 has no possibility of occurrence of aliasing. Value) is used to set the damping control compensation amount (step ST16).

  The input signal determination unit 7n may cause aliasing in the input signals related to all the rotating bodies to be determined if the predetermined rotation state continues in the second motor / generator 132 for a certain period of time. Judgment is made and the vehicle system vibration control is interrupted (step ST17).

The signal selection box 73o switches signals based on the determination result input from the input signal determination unit 7n. The signal selection噐73o, if obtain a judgment result of the step ST12, the switching contacts so that the front wheels _{W FL,} input signals of the wheel speed Vwf of _{W FR} (raw value) is input to the wheel torque estimating unit 7f I do. Similarly, signal selection噐73o is as if to give the decision result in the step ST14, the rear wheels _{W RL,} the input signals of the wheel speed Vwr of _{W RR} (raw value) is input to the wheel torque estimating unit 7f When the contact is switched and the determination result of step ST16 is obtained, the contact is switched so that the input signal (raw value) of the motor rotation speed Nmg is input to the wheel torque estimating unit 7f.

As described above, in the vehicle control apparatus of the second embodiment, when there is no possibility of occurrence of aliasing in the input signal related to the first rotating body (front wheels W _FL , W _FR ), the raw front wheels W _FL , W _FR The wheel torque fluctuation (the wheel torque estimated value Tw) can be accurately estimated using the input signal of the wheel speed Vwf, and it is possible to suppress the on-spring vibration of the vehicle body with high accuracy by appropriate vehicle system vibration control. . On the other hand, in this vehicle control device, when there is a possibility of occurrence of aliasing in the input signal related to the rotating body (front wheels W _FL , W _FR ), other rotating bodies (rear wheels W _RL , W _RR and second wheel The same determination is made for the motor / generator 132), and the input signal is switched so as not to cause aliasing. For this reason, in this vehicle control apparatus, it is possible to accurately estimate the vibration state using a raw input signal that does not cause the occurrence of aliasing even in this case. In this vehicle control device, an input signal that is unlikely to cause aliasing is found in this way, and the vibration state is estimated by switching to the input signal. Therefore, this vehicle body control device can use a raw input signal that is free from the occurrence of aliasing, so that an appropriate amount of vibration suppression control compensation can be set without causing a signal delay due to filtering. Therefore, it is possible to suppress the sprung vibration of the vehicle body with high accuracy by appropriate vehicle system vibration control.

  Here, in the second embodiment, it is determined that there is a possibility of occurrence of aliasing when the predetermined rotation state continues for a certain time. Alternatively, it may be determined that there is a possibility of occurrence of aliasing when the predetermined rotation state is determined a predetermined number of times within a predetermined time.

  Further, in order to avoid a delay due to the filtering process, the occurrence of aliasing may be suppressed by changing the sampling frequency (for example, the calculation cycle or the transmission cycle) of the input signal that is determined to have a possibility of occurrence of aliasing. Good.

[Example 3]
A vehicle control apparatus according to a third embodiment of the present invention will be described with reference to FIGS.

  In the vehicle control apparatus according to the second embodiment described above, if there is a possibility of occurrence of aliasing, the control signal is switched to another input signal, and the vibration suppression control compensation amount is set with a raw input signal that is not subjected to filter processing. . However, in the vehicle control apparatus according to the second embodiment, an appropriate vibration suppression control compensation amount cannot be set unless it is detected or estimated in advance that aliasing may occur with respect to at least one input signal. Further, in the vehicle control apparatus of the second embodiment, appropriate control is not performed unless it is detected or estimated that there is a possibility of occurrence of aliasing in real time, for example, when a secular change of the rotating body occurs. Vibration control compensation amount cannot be set.

  Therefore, in the third embodiment, when a predetermined state is detected in a predetermined region with respect to a predetermined signal related to the vibration suppression control of the vehicle body, a sampling frequency (for example, a calculation cycle or a transmission cycle) related to the signal is detected. To change.

  Here, the predetermined signal is at least one of the various input signals exemplified above.

  The predetermined region means that when the predetermined signal is the rotational speed (input signal) of the rotating body, for example, the aliasing frequency fa related to the input signal is within a predetermined range. The aliasing frequency fa is calculated based on Equation 17 described above using the frequency f0 of the input signal (source signal) and the sampling frequency fs known in advance. In this calculation, the frequency f0 of the input signal (source signal) is regarded as “f0 = rotational speed (rps) × n-order component”. Here, when the aliasing frequency fa (a false frequency in aliasing due to the sampling period) is at a low frequency (near 1.5 Hz), it is determined that the input signal determination unit 7n is in a predetermined region. Further, the input signal determination unit 7n may determine that the input signal determination unit 7n is in the predetermined region when the aliasing frequency fa is equal to or lower than the predetermined frequency. The frequency equal to or lower than the predetermined frequency refers to a state where noise cannot be removed even if the signal is subjected to filter processing such as LPF. In the case of the unsprung vibration suppression control, the aliasing frequency fa is in the predetermined region when it is near 14 Hz, and when the drive system vibration suppression control is in the vicinity of 8 Hz.

  The time when a predetermined signal is in a predetermined state is when aliasing has occurred with respect to that signal. This time corresponds to, for example, a case where the input signal determination unit 7n performs frequency analysis of the signal and a certain frequency magnitude in the analysis result is equal to or greater than a predetermined magnitude. Here, FFT (Fast Fourier Transform) analysis is performed. A certain frequency is, for example, a frequency that is predetermined as a determination target among all frequencies in the analysis result. The predetermined size is a threshold value for determining that aliasing is present.

  The input signal determination unit 7n may determine the occurrence of aliasing when the frequency to be determined in the FFT analysis result of the signal is equal to or greater than a predetermined magnitude, but in order to ensure the accuracy of the determination, Here, it is determined that aliasing has occurred when the state has been continuously detected for a certain period of time. When the input signal determination unit 7n determines that aliasing has occurred, the input signal determination unit 7n requests the input signal processing unit 7o to perform a signal cycle change process.

  Specifically, as shown in the flowchart of FIG. 10, the input signal determination unit 7n performs, for example, an FFT analysis of the wheel speed Vw (= r · ω) as an input signal (step ST21), and the frequency to be determined in the analysis result. Is determined to be equal to or larger than a predetermined size for a predetermined time (step ST22).

  The input signal determination unit 7n determines that aliasing has not occurred unless the frequency to be determined continues to be greater than or equal to a predetermined value for a certain period of time, and calculates the calculation period of the signal subjected to the FFT analysis. Alternatively, it is determined that there is no need to change the transmission cycle (step ST23). Upon receiving this determination result, the input signal processing unit 7o of the third embodiment sends the raw value of the signal (here, the wheel speed Vw) subjected to the FFT analysis to the wheel torque estimating unit 7f, and uses that signal. Calculate the damping control compensation amount. Therefore, the vehicle body control device at this time can suppress the sprung vibration of the vehicle body with high accuracy by appropriate vehicle system vibration control.

  On the other hand, the input signal determination unit 7n determines that aliasing has occurred when the frequency to be determined is equal to or greater than a predetermined value for a certain period of time, and calculates the signal subjected to FFT analysis. A request for changing the cycle or the transmission cycle is requested (step ST24).

  The input signal processing unit 7o that has received the cycle change processing request determines whether or not the cycle can be changed to a cycle that can suppress the occurrence of aliasing (step ST25). For example, when determining whether it is possible to change the calculation cycle of the wheel speed Vw, the input signal processing unit 7o is based on the calculation processing capability (maximum calculation cycle or minimum calculation cycle) of the braking control device 9. It is determined whether or not it is possible to change to an operation cycle that can suppress the occurrence of aliasing. Further, when determining whether or not the transmission cycle of the wheel speed Vw can be changed, the input signal processing unit 7o is based on the arithmetic processing capability (maximum transmission cycle or minimum transmission cycle) of the braking control device 9. It is determined whether or not it is possible to change to a transmission cycle that can suppress the occurrence of aliasing.

  If the cycle can be changed, the input signal processing unit 7o causes the target device to execute a change process to a cycle that can suppress the occurrence of aliasing (step ST26). For example, when changing the calculation cycle or the transmission cycle of the wheel speed Vw, the input signal processing unit 7o causes the braking control device 9 to execute a process for changing the calculation cycle or the transmission cycle of the wheel speed Vw. Thereby, in the subsequent input signal determination unit 7n, the determination in step ST22 is performed based on the FFT analysis result of the signal after the period change, and it is determined that aliasing has not occurred, and the process proceeds to step ST23. Become. Therefore, the vehicle body control device at this time can suppress the sprung vibration of the vehicle body with high accuracy by appropriate vehicle system vibration control based on the raw value of the input signal (wheel speed Vw).

  On the other hand, if the input signal processing unit 7o determines that the cycle cannot be changed, the input signal processing unit 7o gives an instruction to interrupt the vehicle body vibration suppression control (step ST27). For example, the input signal processing unit 7o at that time sends an instruction to the FF control gain setting unit 7i and the FB control gain setting unit 7k in order to interrupt the vibration suppression control of the vehicle body. The FB control gain K · FB is set to zero. As a result, in the vibration suppression control amount calculation unit 7, the FF system damping torque compensation amount U · FF and the FB system damping torque compensation amount U · FB become 0, and the wheel torque compensation value as the damping control compensation amount Since Twc and damping control torque Tdc become 0, damping control is interrupted. For this reason, this vehicle control device can avoid execution of erroneous vibration suppression control due to aliasing. Further, here, the vibration suppression control of the vehicle body is interrupted, but the input signal processing unit 7o decreases the FF control gain K · FF and the FB control gain K · FB to reduce the vibration suppression control compensation amount (the wheel torque compensation value Twc). Or the vibration suppression control torque Tdc) may be kept low. As a result, even if aliasing and vibration occur at the same time, the vehicle control device can suppress the execution of erroneous vibration suppression control due to aliasing, and can also suppress the vibration of the vehicle body. Therefore, for the FF control gain K · FF and the FB control gain K · FB when the cycle cannot be changed, the FF control gain K · FF and the FB control gain K · FB are reduced to 0 at the maximum. Also good.

  As described above, the vehicle control device according to the third embodiment can execute the vehicle system vibration control using the signal in which aliasing has not occurred. In this vehicle control device, since it is possible to determine in real time whether aliasing has occurred in the signal, even if it is impossible to detect or estimate in advance that there is a possibility of aliasing, for example, the secular change of the rotating body may occur. Even if it has occurred, an appropriate vibration suppression control compensation amount can be set, and appropriate vehicle system vibration control can be executed.

  Here, when judging whether or not aliasing occurs by looking at the magnitude of the frequency in the FFT analysis result, the input signal determination unit 7n erroneously determines that aliasing is caused by the environment in which the vehicle is placed. There is a risk of doing. For example, when there is a large road surface input, there is a risk of erroneously determining that aliasing is occurring by looking at a frequency that has become a predetermined magnitude or more with the road surface input. For this reason, when it is determined that aliasing occurs, the same FFT analysis is performed for another signal, and the magnitude of the frequency in the analysis result is also observed. The input signal determination unit 7n compares the FFT analysis results for a plurality of signals, and each FFT analysis result becomes an equivalent result, and when a certain frequency in each is similarly equal to or larger than a predetermined size, Judgment is due to road surface input and not aliasing. This determination is made on condition that the calculation cycle of all signals is not an integral multiple of another cycle (for example, the transmission cycle of the signal). In this case, since the environment in which the vehicle is placed is an environment with a large road surface input, for example, the sampling frequency (calculation cycle or transmission cycle) of the signal according to such an environment is set. On the other hand, the FFT analysis results of the input signal determination unit 7n are different, and a certain frequency at each frequency is a predetermined size or larger and a predetermined frequency is not mixed. In this case, it is determined that aliasing has occurred for a signal having a predetermined magnitude or more. In this case, the environment in which the vehicle is placed is an environment in which there is no large road surface input, for example, but in an environment in which aliasing occurs, the sampling frequency of the signal in accordance with such an environment (calculation cycle) Or transmission cycle).

For example, as shown in the flowchart of FIG. 11, the input signal determination unit 7n performs FFT analysis on the wheel speeds Vwf (= r · ω) of the front wheels W _FL and W _FR (step ST31), and the determination target in the analysis result It is determined whether or not the frequency continues to be a predetermined magnitude or more for a predetermined time (step ST32).

The input signal determination unit 7n, unless become greater than or equal to a predetermined magnitude frequency to be determined is continued a predetermined time, the front wheels W _FL, a judgment that aliasing does not occur with respect to the wheel speed Vwf of W _FR done Thus, it is determined that there is no need to change the calculation cycle or transmission cycle of the wheel speed Vwf (step ST33). Upon receiving this determination result, the input signal processing unit 7o sends the raw value of the input signal of the wheel speed Vwf of the front wheels W _FL and W _FR to the wheel torque estimating unit 7f, and uses the input signal to determine the damping control compensation amount. Calculate. Therefore, the vehicle body control device at this time can suppress the sprung vibration of the vehicle body with high accuracy by appropriate vehicle system vibration control.

On the other hand, the input signal determination unit 7n indicates that there is a possibility that aliasing may occur with respect to the wheel speeds Vwf of the front wheels W _FL and W _FR when the frequency to be determined is a predetermined magnitude or more continuously for a predetermined time. Judgment is performed, and the wheel speed Vwr (= r · ω) of the rear wheels W _RL and W _RR is subjected to FFT analysis (step ST 34), and the frequency to be determined in the analysis result continuously exceeds a predetermined magnitude for a predetermined time. It is determined whether or not (step ST35).

Input signal judgment unit 7n, the aliasing is generated with respect to the wheel speed Vwr of this step ST35 frequency to be determined is continued a predetermined time when it is determined that it is not equal to or greater than a predetermined size, the rear wheels W _RL, W _RR It is determined that it is not necessary, and it is determined that there is no need to change the calculation cycle or transmission cycle of the wheel speed Vwr (step ST36). In this case, it also leads to a determination that aliasing has occurred with respect to the wheel speeds Vwf of the front wheels W _FL and W _FR , so that the input signal processing unit 7 o that has received the determination results in the rear wheels W _RL and W _RR. The raw value of the input signal of the wheel speed Vwr is sent to the wheel torque estimating unit 7f, and the vibration suppression control compensation amount is calculated using the input signal. Therefore, the vehicle body control device at this time can suppress the sprung vibration of the vehicle body with high accuracy by appropriate vehicle system vibration control.

Further, the input signal determination unit 7n, when determining that the frequency of the determination target even step ST35 is equal to or greater than a predetermined size continues a predetermined time, the front wheels W _FL, the wheel speed Vwf of W _FR, the rear wheel W _RL, both the wheel speed Vwr of _{W RR,} it is determined that the determination result is due to the road surface input rather than the aliasing, the wheel speed Vwr of the front wheels _{W FL, W} wheel speed Vwf and the rear wheels _W RL of _{FR, W RR} It is determined that there is no need to change the calculation cycle or the transmission cycle (step ST37). The determination result of the input signal processing unit 7o having received the front wheels _{W FL,} feed _{W FR} wheel speed Vwf or rear wheel _{W RL,} the raw value of the input signal of the wheel speed Vwr of _{W RR} to the wheel torque estimating unit 7f, The damping control compensation amount is calculated using the input signal. Therefore, the vehicle body control device at this time can suppress the sprung vibration of the vehicle body with high accuracy by appropriate vehicle system vibration control.

  Thus, when the aliasing is occurring, the vehicle control device can execute the vehicle system vibration control by switching to another signal where the aliasing has not occurred. Also in this vehicle control device, since the presence or absence of aliasing with respect to the signal can be determined in real time, even if it is impossible to detect or estimate in advance that there is a possibility of occurrence of aliasing, for example, the secular change of the rotating body may occur. Even if it has occurred, an appropriate vibration suppression control compensation amount can be set, and appropriate vehicle system vibration control can be executed.

Here, when the frequency of the determination target at the step ST35 is determined to continue a certain time is not equal to or greater than a predetermined magnitude, the input signal determination unit 7n, the front wheels W _FL, the wheel speed Vwf of W _FR You may request the change process of a calculation period or a transmission period. Then, the input signal processing unit 7o, by determining whether it is possible to change to a period that may suppress the occurrence of aliasing, changes if possible, computation of wheel speed Vwf of front wheels W _FL, W _FR Change the cycle or transmission cycle. Thereby, in the subsequent input signal judgment unit 7n, the front wheels W _FL after cycle _change, the determination in step ST32 based on the FFT analysis result of the wheel speed Vwf of W _FR is performed, it determines that aliasing does not occur Then, it will progress to step ST33. Therefore, the vehicle body control device at this time can suppress the sprung vibration of the vehicle body with high accuracy by appropriate vehicle system vibration control based on the raw value of the input signal of the wheel speed Vwf of the front wheels W _FL and W _FR. Can do. Here, even if they are determined to not be changed in the necessity determination period changed, the rear wheels W _RL, since it calculates the appropriate damping control compensation amount using the wheel speed Vwr of W _RR, previous It is desirable not to interrupt the vibration suppression control as illustrated.

  Further, here, the FFT analysis results of a plurality of signals are compared to determine whether aliasing is present or not. For example, for a signal related to a certain type of rotating body, the same time is shifted as in one cycle or the like. The presence or absence of aliasing may be determined by comparing the FFT analysis results of the signals of the rotating body.

By the way, in the third embodiment, the same input signal as that of the first and second embodiments described above is given as an example of the predetermined signal. However, as the predetermined signal, the output signal (the wheel torque compensation which is the damping control compensation amount) is used. The value Twc or the vibration suppression control torque Tdc) may be used. In this case, in the example shown in FIG. 10, the vibration suppression control compensation amount (wheel torque compensation value Twc or vibration suppression control torque Tdc) calculated based on, for example, the wheel speed Vw as an input signal is subjected to FFT analysis in step ST21. When the cycle changing process is performed in step ST26, for example, the calculation cycle of the FF system damping torque compensation amount U / FF and the FB system damping torque compensation amount U / FB in the FF control changing unit 7h and the FB control changing unit 7j. Alternatively, the transmission cycle, or the calculation cycle or transmission cycle of the vibration suppression control torque Tdc in the drive torque conversion unit 7m is changed to a cycle that can suppress the occurrence of aliasing. In the example shown in FIG. 11, the damping control compensation amount (wheel torque compensation value Twc or damping control torque Tdc) calculated based on the wheel speeds Vwf of the front wheels W _FL and W _FR in step ST31 is subjected to FFT analysis. , the rear wheels _W RL in step _ST34, damping control compensation amount calculated based on the wheel speed Vwr of _{W RR} (wheel torque compensation value Twc or damping control torque Tdc) FFT is analyzing. Even in these cases, the same effect as that of the previous input signal can be obtained in each of them.

  Further, when the input signal is a detection signal of the acceleration sensor, it can be considered that a surge is directly applied. For this reason, the case where the predetermined signal in this case is in the predetermined state corresponds to the case where the input signal is viewed in a time series in the order of input and exceeds a predetermined magnitude. The predetermined size is a threshold for determining that aliasing is occurring.

  In this example, it is determined that aliasing is caused when the frequency to be determined is equal to or greater than a predetermined value for a predetermined time. Alternatively, it may be determined that aliasing is detected when a state in which the frequency to be determined is equal to or greater than a predetermined magnitude is detected a predetermined number of times within a predetermined time.

  In addition, the input signal determination unit 7n is configured to determine whether or not the determination target frequency is equal to or greater than a predetermined magnitude in the predetermined area described above, but regardless of such an area, Such a determination may be executed.

  Further, in the third embodiment, the occurrence of aliasing is suppressed by changing the sampling frequency. For the suppression, the control gain (FB control gains K · FB, FF) is used as described in the second embodiment. The control gain (K · FF) may be changed to decrease.

  As described above, the vehicle control device according to the present invention is useful for a technique for suppressing a decrease in vibration suppression performance due to aliasing.

DESCRIPTION OF SYMBOLS 1 Driver request | requirement calculation part 2 Vehicle drive torque calculation part 3 Engine control amount calculation part 4 Engine control part 5 MG control amount calculation part 6 MG control part 7 Vibration suppression control amount calculation part 7a Feedforward control part 7b Feedback control part 7d Motion Model unit 7f Wheel torque estimation unit 7h FF control change unit 7i FF control gain setting unit 7j FB control change unit 7k FB control gain setting unit 7l Adder 7m Drive torque conversion unit 7o Input signal processing unit 7n Input signal determination unit 8 Vibration information Detector 9 Braking control device 71o Filter 72o Signal selection ７３ 73o Signal selection ａｄ add1 Adder

Claims (7)

In a vehicle control device that controls a drive control amount of a drive source to suppress vibration generated in the vehicle body,
When aliasing occurs for a signal related to vibration information or a signal related to a vibration suppression control compensation amount calculated based on the vibration information, suppression of deterioration in vibration suppression performance is suppressed to suppress a decrease in vibration suppression performance due to the aliasing. A vehicle control device comprising the device.   The vehicle control device according to claim 1, wherein the vibration suppression performance reduction suppressing device includes a filter that passes only a predetermined frequency component of a signal related to the vibration information and suppresses the occurrence of the aliasing.   The vehicle control device according to claim 2, wherein the filter cuts a frequency higher than a Nyquist frequency.   The vehicle control device according to claim 1, wherein the vibration suppression performance reduction suppressing device suppresses the occurrence of aliasing by changing a sampling frequency related to the signal according to an environment in which the vehicle is placed.   The vibration suppression performance deterioration suppressing device suppresses the occurrence of aliasing, while interrupting the vibration suppression control for the vibration or suppressing the vibration suppression control compensation amount to a low level if the occurrence of the aliasing cannot be suppressed. The vehicle control device according to claim 1.   The vehicle control device according to claim 5, wherein the vibration suppression performance lowering suppression device reduces a gain used for calculating the vibration suppression control compensation amount to 0 at the maximum. In a vehicle control device that controls a drive control amount of a drive source to suppress vibration generated in the vehicle body,
When aliasing occurs in a signal related to vibration information, a vibration suppression control compensation amount for suppressing the vibration is obtained using a signal obtained by cutting a frequency higher than the Nyquist frequency of the signal, and the vibration suppression control A vehicle control apparatus that controls the drive source based on a compensation amount.

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