JP2006298293A - Vehicle-control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize stable oscillation-restrictive control which is not affected by the weight of loads. <P>SOLUTION: An oscillation-restrictive filter 13 is provided, which removes components in a prescribed frequency band, which gives rise to an oscillation on a spring of a vehicle, from a wave form of a request braking-and-driving force which is computed by a required braking-and-driving force computation means 11 based on a driver's driving operation quantity or the like. Then, the required braking-and-driving force, which is filtered by the oscillation-restrictive filter 13, is inputted to a control means 14 to control the braking-and-driving force. Further, a weight-of-load detection means 18 is provided, which detects the weight of loads which varies depending on the number of people on board, quantities of loaded cargoes or quantity of fuel, and a filter characteristic correction means 19, which corrects the characteristics of the oscillation-restrictive filter 13, is also provided to correct the characteristics of the oscillation-restrictive filter 13 in accordance with the weight of loaded cargoes on board. Accordingly, even if oscillation characteristics on a vehicle spring vary depending on the number of people on board, the quantities of cargoes on board or quantity of fuel, the characteristics of the oscillation-restrictive filter can be corrected so that the characteristics concerned may be consistent with the oscillation characteristics of the vehicle spring in accordance with the variation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle control device having a function of controlling braking / driving force (driving force and braking force) on a vehicle so as to suppress vibration on a spring of the vehicle.

In recent years, in order to optimize vehicle vibration suppression control, an input corresponding to at least one of an accelerator operation, a steering operation, and a brake operation by a driver as shown in Patent Document 1 (Japanese Patent Application Laid-Open No. 2004-168148). An engine that suppresses vehicle vibration using a motion model that is a dynamic model of vehicle tire vibration, suspension under vehicle spring vibration in suspension, and vibration on vehicle spring received by the vehicle itself. And / or the technique which correct | amends the braking / driving force which generate | occur | produces with a brake device is developed.
JP 2004-168148 A (the second page etc.)

  By the way, it is necessary to design the vibration suppression control characteristics so as to match the vehicle sprung vibration characteristics, but the vehicle sprung vibration characteristics depend on the number of passengers, the amount of load and the amount of fuel that changes depending on the vehicle loading weight. Therefore, there is a possibility that the actual vehicle sprung vibration characteristic and the vibration suppression control characteristic shift due to increase / decrease in the vehicle load weight, and the vibration reduction effect by the vibration suppression control may be reduced.

  The present invention has been made in view of such circumstances, and therefore an object of the present invention is to provide a vehicle control apparatus capable of performing stable vibration suppression control independent of the vehicle load weight.

  In order to achieve the above object, an invention according to claim 1 is directed to a vehicle control device that controls braking / driving force on a vehicle in accordance with required braking / driving force, and vibration on a spring of the vehicle from a waveform of the requested braking / driving force. A damping filter that removes a component that induces the vehicle, a control unit that controls the braking / driving force according to the requested braking / driving force filtered by the damping filter, a loaded weight detection unit that detects a loaded weight of the vehicle, Filter characteristic correction means for correcting the characteristics of the vibration damping filter based on the vehicle load weight detected by the load weight detection means. In this configuration, even if the vehicle loaded weight changes due to the number of passengers, the amount of loaded luggage, and the amount of fuel, and the vehicle sprung vibration characteristics change, the characteristics of the damping filter are matched with the vehicle sprung vibration characteristics accordingly. Therefore, stable vibration control can be performed regardless of the vehicle load weight.

  In this case, since the lift according to the aerodynamic characteristic acts on the vehicle while traveling, the loaded weight of the traveling vehicle is substantially reduced by the amount of lift. In consideration of this point, vehicle speed detection means for detecting the vehicle speed, and lift estimation means for estimating the lift acting on the traveling vehicle based on the vehicle speed detected by the vehicle speed detection means, as in claim 2 A value obtained by subtracting a weight corresponding to the lift estimated by the lift estimation means from the vehicle load detected by the load weight detection means is regarded as a substantial vehicle load weight during traveling. It is preferable to correct the characteristics of the vibration damping filter based on the weight. In this way, even if the vehicle speed increases and the lift acting on the vehicle increases, the characteristic of the vibration damping filter is corrected based on the substantial vehicle load weight obtained by subtracting the weight equivalent to the lift, The characteristics of the damping filter can be matched with the vehicle sprung vibration characteristics in a state where the lift is applied, and stable damping control independent of the lift acting on the vehicle can be performed.

  In general, in consideration of the fact that the frequency of vibration on the vehicle spring tends to decrease as the vehicle loading weight increases, the filter characteristic correction means, as described in claim 3, provides the vibration damping filter as the vehicle loading weight increases. It is preferable to correct the characteristic so that the frequency in the attenuation region is lowered. In this way, the vehicle sprung vibration can be effectively suppressed regardless of the vehicle loading weight.

  Further, in consideration of the tendency that the greater the vehicle load weight, the smaller the amplitude of the vehicle sprung vibration tends to be, the filter characteristic correction means, as described in claim 4, the filter characteristic correction means increases the vehicle load weight. It is preferable to correct this characteristic so that the attenuation rate becomes small. In this way, it is possible to avoid excessive vibration damping effects when the vehicle loading weight is heavy, or to avoid insufficient vibration damping effects when the vehicle loading weight is light. An appropriate vibration damping effect according to the weight can be obtained.

  Hereinafter, two Examples 1 and 2, which embody the best mode for carrying out the present invention, will be described.

  A first embodiment of the present invention will be described with reference to FIGS. First, the configuration of the vehicle braking / driving force control system will be described with reference to FIG.

  The required braking / driving force calculating means 11 calculates the required braking / driving force based on the driving operation amount of the driver (for example, the depression amount of the accelerator pedal, the depression amount of the brake pedal, the steering angle of the steering wheel, etc.) and cruise control. In a vehicle equipped with various automatic travel control systems such as (constant speed travel control), traction control, and vehicle body behavior control (VDC), the required braking / driving force for executing these automatic travel controls is calculated. Thereby, when a plurality of required braking / driving forces are calculated, any one required braking / driving force is selected (arbitration) as the final required braking / driving force.

  The required braking / driving force output from the required braking / driving force calculating means 11 is input to the vibration damping filter 13. The vibration suppression filter 13 is a filter that removes a component of a predetermined frequency band that induces vibration on the spring of the vehicle from the waveform of the required braking / driving force input from the required braking / driving force calculating means 11. (Band rejection filter) or the like. The requested braking / driving force filtered by the vibration damping filter 13 is input to the control means 14.

  The control means 14 controls the engine driving force by operating the engine driving means 16 (fuel injection device, ignition device, electronic throttle device, etc.) according to the required braking / driving force filtered by the vibration damping filter 13 and brakes. The driving means 17 is operated to control the braking force, and the vehicle drive system is driven or braked with the braking / driving force generated thereby.

  The loaded weight detection means 18 detects the loaded weight of the vehicle that varies depending on the number of passengers, the amount of loaded luggage and the amount of fuel. The loaded weight detection means 18 detects, for example, the stroke amount of the suspension device, detects the number of passengers with a seating sensor provided in each seat, detects the remaining amount of fuel with a fuel fuel gauge, or The vehicle loading weight may be detected by a combination of the road surface gradient detected by the road surface gradient sensor and the acceleration detected by the acceleration sensor.

  The characteristics of the damping filter 13 need to be designed so as to match the vehicle sprung vibration characteristics, but the vehicle sprung vibration characteristics change according to the vehicle load weight that changes depending on the number of passengers, the amount of load, and the amount of fuel. Therefore, if the characteristics of the damping filter 13 are constant, the actual vehicle sprung vibration characteristic and the damping control characteristic are shifted due to increase / decrease of the vehicle load weight, and the vibration reduction effect by the damping filter 13 is reduced. End up.

Therefore, in the first embodiment, filter characteristic correction means 19 for correcting the characteristic of the vibration suppression filter 13 is provided, and the characteristic of the vibration suppression filter 13 is corrected according to the vehicle load weight detected by the load weight detection means 18. ing. The characteristic of the damping filter 13 is represented by the following transfer function G (s).
G (s) = (s ² + 2ζp ωp s + ωp ² ) / (s ² + 2ζωp s + ωp ² )
ωp: vehicle angular frequency after correction [rad / s]
ζ: desired vehicle damping coefficient
ζp: Corrected vehicle damping coefficient

  The filter characteristic correcting means 19 corrects the characteristic of the damping filter 13 so that the attenuation rate (attenuation coefficient ζp) becomes smaller as the vehicle loading weight becomes heavier, and as the vehicle loading weight becomes heavier. The characteristic is corrected so that the frequency of the attenuation region (angular frequency ωp) becomes small.

  The correction of the characteristics of the damping filter 13 and the control of the braking / driving force based on the vehicle loading weight described above are executed according to the routines shown in FIGS. The processing contents of each routine will be described below.

  The braking / driving force control main routine of FIG. 2 is executed at a predetermined cycle during engine operation. When this routine is started, first, in step 101, a filter characteristic correction coefficient calculation routine of FIG. 3 to be described later is executed to calculate an attenuation coefficient correction coefficient Kz and an angular frequency correction coefficient Kw according to the vehicle loading weight ratio WR. To do.

Thereafter, the process proceeds to step 102, where the vehicle angular frequency initial value ωn is multiplied by the angular frequency correction coefficient Kw to obtain a corrected vehicle angular frequency ωp, and the vehicle damping coefficient initial value ζn is multiplied by the damping coefficient correction coefficient Kz. The corrected vehicle damping coefficient ζp is obtained.
ωp = Kw × ωn
ζp = Kz × ζn

  Thereafter, the process proceeds to step 103, and the transfer function G (s) of the vibration suppression filter 13 is calculated. Then, in the next step 104, a braking / driving force correction routine (not shown) is executed, and the requested braking / driving force output from the requested braking / driving force calculating means 11 is calculated in step 103. The transfer function G (s) is input to the waveform of the required braking / driving force to remove a component in a predetermined frequency band that induces vibration on the spring of the vehicle. The engine driving means 16 is operated in accordance with the required braking / driving force to control the engine driving force, and the brake driving means 17 is operated to control the braking force. The vehicle is driven by the braking / driving force generated thereby. Drive or brake the system.

On the other hand, when the filter characteristic correction coefficient calculation routine of FIG. 3 is started in step 101, first, in step 111, the detection of the total vehicle weight including the vehicle loading weight is completed, for example, by detecting the stroke amount of the suspension device or the like. If the detection of the total vehicle weight has not been completed, the process proceeds to step 115 where the attenuation coefficient correction coefficient Kz is set to the attenuation coefficient correction coefficient initial value Kz0 and the angular frequency correction coefficient Kw is set to the angular frequency correction coefficient Kw. The frequency correction coefficient initial value Kw0 is set.
Kz = Kz0
Kw = Kw0

On the other hand, if it is determined in step 111 that the detection of the total vehicle weight has been completed, the process proceeds to step 112 where the detected value of the total vehicle weight is set to W, and in the next step 113, the current total vehicle weight W is determined. By dividing by the total vehicle weight Wmax at the time of maximum loading, the current vehicle loading weight ratio WR [%] is obtained.
WR = (W / Wmax) × 100

  Thereafter, the routine proceeds to step 114, where the attenuation coefficient correction coefficient Kz corresponding to the current vehicle loading weight ratio WR is calculated with reference to the attenuation coefficient correction coefficient Kz table Tztbl (WR) of FIG. With reference to the frequency correction coefficient Kw table Twtbl (WR), an angular frequency correction coefficient Kw corresponding to the current vehicle loading weight ratio WR is calculated. The damping coefficient correction coefficient Kz table Tztbl (WR) in FIG. 4 is set such that the damping coefficient correction coefficient Kz decreases as the vehicle loading weight ratio WR increases. The angular frequency correction coefficient Kw table Twtbl (WR) in FIG. Is set such that the angular frequency correction coefficient Kw decreases as the vehicle loading weight ratio WR increases. As a result, the corrected vehicle angular frequency ωp and the corrected vehicle damping coefficient ζp calculated in step 102 in FIG. 2 are calculated so as to decrease as the vehicle loading weight ratio WR increases.

  According to the first embodiment described above, the load weight detecting means 18 detects the vehicle load weight (vehicle load weight ratio WR), and the characteristics of the vibration damping filter 13 are reduced as the vehicle load weight ratio WR increases. Since the damping coefficient ζp) and the frequency of the damping region (angular frequency ωp) are corrected to be small, the vehicle loading weight changes depending on the number of passengers, the amount of load, and the amount of fuel, and the vibration characteristics on the vehicle spring changes. Even so, the characteristic of the vibration damping filter can be corrected so as to match the vibration characteristic on the vehicle spring, and stable vibration damping control independent of the vehicle loading weight can be performed.

  By the way, since the lift according to an aerodynamic characteristic acts on a vehicle during driving | running | working, the loading weight of the vehicle during driving | running | working substantially becomes light by the part of lift. In consideration of this point, in the second embodiment of the present invention, by executing the filter characteristic correction coefficient calculation routine of FIG. 6, the vehicle running is detected based on the vehicle speed V detected by the vehicle speed sensor (vehicle speed detection means). The effective lifting force L is calculated, and the value obtained by subtracting the weight L / g corresponding to the lifting force L from the vehicle loading weight detected by the loading weight detection means 18 is regarded as the substantial vehicle loading weight during traveling. The characteristics of the damping filter 13 are corrected based on the vehicle load weight.

  Also in the second embodiment, the braking / driving force control main routine of FIG. 2 described in the first embodiment is executed at a predetermined cycle, and in step 101, the filter characteristic correction coefficient calculation routine of FIG. 6 is executed. In the filter characteristic correction coefficient calculation routine of FIG. 6, first, at step 211, it is determined whether or not the detection of the total vehicle weight including the vehicle loading weight has been completed, for example, by detecting the stroke amount of the suspension device, and the like. If the detection is not completed, the process proceeds to step 217, where the attenuation coefficient correction coefficient Kz and the angular frequency correction coefficient Kw are set to initial values Kz0 and Kw0, respectively.

  If it is determined in step 211 that the detection of the total vehicle weight has been completed, the process proceeds to step 212, where it is determined whether the vehicle speed V is detected by the vehicle speed sensor (vehicle speed detection means), and the vehicle speed V is still detected. If not, the process proceeds to step 217, and the attenuation coefficient correction coefficient Kz and the angular frequency correction coefficient Kw are set to initial values Kz0 and Kw0, respectively.

On the other hand, if the detection of the vehicle speed V is completed, the process proceeds to step 213, and the lift L corresponding to the vehicle speed V is calculated by the following equation.
L = 1/2 × C1 × ρ × V ² × S
C1: Lift coefficient
ρ: Air density
S: Vehicle lower surface projected area The processing of step 213 serves as lift estimation means in the claims.

  Thereafter, the process proceeds to step 214, and a value obtained by subtracting a weight L / g corresponding to lift from the current total vehicle weight is set as a substantial total vehicle weight W during traveling. Thereafter, the process proceeds to step 215, where the current total vehicle weight W is divided by the maximum total vehicle weight Wmax at the time of maximum loading to obtain the current vehicle loading weight ratio WR [%].

  Thereafter, the process proceeds to step 216, where the attenuation coefficient correction coefficient Kz corresponding to the current vehicle loading weight ratio WR is calculated with reference to the attenuation coefficient correction coefficient Kz table Tztbl (WR) of FIG. With reference to the frequency correction coefficient Kw table Twtbl (WR), an angular frequency correction coefficient Kw corresponding to the current vehicle loading weight ratio WR is calculated.

  According to the first embodiment described above, the lift L acting on the traveling vehicle is calculated based on the vehicle speed V detected by the vehicle speed sensor (vehicle speed detection means), and the vehicle load weight detected by the load weight detection means 18 is calculated. Since the value obtained by subtracting the weight L / g corresponding to lift from the vehicle is regarded as the substantial vehicle loaded weight during traveling, the characteristic of the vibration damping filter 13 is corrected based on the substantial vehicle loaded weight. Even if the vehicle speed increases and the lift L acting on the vehicle increases, the characteristics of the damping filter 13 can be corrected based on the substantial vehicle load weight obtained by subtracting the weight L / g corresponding to the lift L. . As a result, the characteristics of the damping filter 13 can be matched with the on-spring vibration characteristics in the state where the lift L is applied, and stable damping control independent of the lift acting on the vehicle can be performed.

It is a block diagram which shows the system configuration | structure of Example 1 of this invention. 4 is a flowchart for explaining the flow of processing of a braking / driving force control main routine according to the first embodiment. 6 is a flowchart for explaining a processing flow of a filter characteristic correction coefficient calculation routine according to the first embodiment. It is a figure which shows an example of the attenuation coefficient correction coefficient Kz table Tztbl (WR). It is a figure which shows an example of the angular frequency correction coefficient Kw table Twtbl (WR). 12 is a flowchart for explaining a flow of processing of a filter characteristic correction coefficient calculation routine according to the second embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Required braking / driving force calculating means, 13 ... Damping filter, 14 ... Control means, 16 ... Engine driving means, 17 ... Brake driving means, 18 ... Load weight detecting means, 19 ... Filter characteristic correcting means

Claims (4)

In the vehicle control device that controls the braking / driving force on the vehicle according to the required braking / driving force,
A vibration suppression filter for removing a component that induces vibration on a vehicle spring from the waveform of the required braking / driving force;
Control means for controlling the braking / driving force according to the required braking / driving force filtered by the vibration damping filter;
Load weight detection means for detecting the load weight of the vehicle;
A vehicle control apparatus comprising: filter characteristic correction means for correcting the characteristic of the vibration damping filter based on the vehicle load weight detected by the load weight detection means. Vehicle speed detection means for detecting the vehicle speed;
A lift estimation means for estimating a lift acting on a running vehicle based on the vehicle speed detected by the vehicle speed detection means;
The filter characteristic correction means regards a value obtained by subtracting a weight corresponding to the lift estimated by the lift estimation means from the vehicle load detected by the load weight detection means as a substantial vehicle load during traveling. The vehicle control device according to claim 1, wherein a characteristic of the vibration suppression filter is corrected based on a typical vehicle loading weight.   3. The vehicle control device according to claim 1, wherein the filter characteristic correction unit corrects the characteristic of the vibration suppression filter so that a frequency in an attenuation region becomes lower as the vehicle loading weight increases.   The vehicle control device according to any one of claims 1 to 3, wherein the filter characteristic correcting unit corrects the characteristic of the damping filter so that an attenuation factor becomes smaller as the vehicle loading weight becomes heavier. .

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