JP6024463B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device that controls driving force of a vehicle.

  As a method for maintaining the vehicle's rotational angular velocity (i.e., yaw rate) at an appropriate value while turning and obtaining a favorable vehicle turning performance, conventionally, the front and rear wheel loads have been changed in accordance with changes in driving force or braking force. There has been proposed a method for obtaining a desired vehicle steering characteristic by utilizing the fact that the cornering power of the tire is changed by the movement of the front and rear wheels and the generated force of the front and rear wheels is changed.

  In contrast, the applicant of the present application calculates a target value of the front and rear wheel load movement amount based on the vehicle speed V, the turning radius ρ, the steering angle δ, and the like so that the front and rear wheel load movement amount of the vehicle follows the target value. A technique for improving the vehicle turning performance by controlling the driving force has already been proposed (see, for example, Patent Document 1).

JP 2005-256636 A

  However, the technique described in Patent Document 1 has a problem that the vehicle turning performance cannot be sufficiently improved depending on the vehicle state, or the driver feels uncomfortable when the vehicle turns.

  The present invention has been made in view of these problems, and an object of the present invention is to provide a technique that makes it possible to appropriately control the driving force in accordance with the vehicle state.

Car two control devices made in order to achieve the above object, the basic driving force calculating means, based on an accelerator pedal operation by the driver, the driver calculates the basic required driving force is a driving force required for the vehicle . Further, the target load movement amount calculation means uses the load movement amount between the front and rear wheels of the vehicle as the front and rear wheel load movement amount, and the target load movement that is the front and rear wheel load movement amount for the vehicle to travel stably. Calculate the amount. Further, the load movement amount estimation means estimates the front and rear wheel load movement amount of the vehicle. The driving force correcting means corrects the basic required driving force so that the front and rear wheel load moving amount estimated by the load moving amount estimating means follows the target load moving amount.

Thus, the car two control devices, by the front and rear wheel load movement of the vehicle to correct the base required driving force so as to follow the target load shift amount, it is possible to stabilize the steering characteristics at the time of vehicle operation it can.

  The target load movement amount is expressed by the following equation (16).

すなわち目標荷重移動量は、車両の走行速度（以下、車速ともいう）が小さくなるに従い大きくなるように変化する。

That is, the target load movement amount changes so as to increase as the traveling speed of the vehicle (hereinafter also referred to as vehicle speed) decreases.

  For this reason, for example, when the vehicle is started by turning the steering wheel in a shape close to a stationary stop from a stationary state, the target load movement amount becomes a very large value because the vehicle speed is low. Here, when the target load movement amount is set so as to be the preload, the driving force is greatly reduced. In this case, the driving force is reduced in a state where the vehicle speed is not so high immediately after the start, and the driver feels uncomfortable that the vehicle does not advance so much.

  Further, the target load movement amount is expressed by the following equation (20). Equation (20) is simply calculated without considering the road gradient and the load movement due to acceleration / deceleration. However, the influence of the weight of the vehicle is the same even when the road gradient and load movement are taken into account.

すなわち目標荷重移動量は、車両の重量（以下、車重ともいう）が大きくなるに従い大きくなるように変化する。

That is, the target load movement amount changes so as to increase as the vehicle weight (hereinafter also referred to as vehicle weight) increases.

  Then, the vehicle weight changes depending on the number of passengers or whether heavy luggage is mounted on the trunk. However, for example, when a fixed value assuming that there is one occupant is adopted as the vehicle weight used for calculating the target load movement amount, the target load movement amount is based on the actual vehicle weight when there are a plurality of occupants. Is smaller than the value calculated by

  For this reason, for example, when the target load movement amount is set to a positive value so as to be corrected to the oversteer side in an understeer state during cornering, control for reducing the driving force so as to be a preload is performed. Is done. As a result, the cornering force increases, and the steering characteristic becomes the oversteer side. However, since the target load movement amount is calculated to be smaller than a value based on the actual vehicle weight, the control amount becomes small, and desired steering characteristics may not be obtained.

  Also, when the target load movement amount is set to a positive value so as to correct to the oversteer side when the shift position is set to the R range and the vehicle is understeering while turning in the back, it is driven so as to be the preload when the target load movement amount is set to a positive value. Control is done to reduce the force. However, since the steered wheel is a rear wheel in reverse travel, it is necessary to use a rear load to bring the steering characteristic to the oversteer side, which adversely deteriorates the steering characteristic.

This against the car two control devices, the load shift amount correcting means, the traveling speed of the vehicle, based on at least one shift position and weight, the target load shift amount calculated by the target load movement amount calculating means to correct.

This ensures that the car two control devices, the travel speed of the vehicle, suitably it is possible to change the target load shift amount according to the shift position and the weight change, the traveling speed of the vehicle, due to the shift position and weight The driving force can be appropriately controlled according to the change in the vehicle state.

It is a block diagram which shows the structure of the electronic control apparatus 1 of 1st Embodiment. 3 is a block diagram illustrating a configuration of a running resistance disturbance estimation unit 14. FIG. 3 is a block diagram showing a configuration of a target load movement amount calculation unit 19. FIG. It is a figure explaining the parameter used with a sprung vibration model. 3 is a block diagram showing a configuration of a target load movement amount correction unit 21. FIG.

Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, an electronic control device 1 of this embodiment is mounted on a vehicle and controls an engine 2 of the vehicle.

  The electronic control device 1 inputs signals from the accelerator stroke sensor 3, the intake air amount sensor 4, the crank angle sensor 5, the wheel speed sensor 6, the steering angle sensor 7, the vehicle speed sensor 8, and the navigation device 9.

The accelerator stroke sensor 3 outputs a signal corresponding to the depression amount of the accelerator pedal by the driver.
The intake air amount sensor 4 outputs a signal corresponding to the intake air amount to the engine 2.

The crank angle sensor 5 outputs a pulse signal that causes an edge at every predetermined angle according to the rotation of the crankshaft of the engine 2.
The wheel speed sensor 6 is attached to each of the left front wheel, the right front wheel, the left rear wheel, and the right rear wheel, and outputs a pulse signal in which an edge is generated at every predetermined angle according to the rotation of each wheel shaft.

The steering angle sensor 7 outputs a signal corresponding to the steering angle of the steering wheel of the vehicle.
The vehicle speed sensor 8 outputs a pulse signal in which an edge is generated at every predetermined angle according to the rotation of the drive shaft of the vehicle.

  The navigation device 9 acquires road map data from a map storage medium in which road map data and various types of information are recorded, and based on a GPS signal received via a GPS (Global Positioning System) antenna (not shown) or the like. It is configured to detect the current position and execute route guidance from the current position to the destination. The road map data includes various data such as road position, road type (highway, toll road, general road, etc.), road shape, road width, road name, number of lanes, road gradient, and the like. The navigation device 9 includes a yaw rate sensor (not shown) that detects the yaw rate of the vehicle.

  The electronic control device 1 includes a basic required torque calculation unit 11, an estimated driving wheel torque calculation unit 12, a wheel speed calculation unit 13, a running resistance disturbance estimation unit 14, a steering angle calculation unit 15, a vehicle speed calculation unit 16, and a road gradient acquisition unit. 17, a virtual turning radius calculation unit 18, a target load movement amount calculation unit 19, a vibration suppression correction unit 20, and a target load movement amount correction unit 21.

The basic required torque calculation unit 11 calculates an accelerator pedal depression amount based on a signal from the accelerator stroke sensor 3, and further calculates a torque T _{w_tgt} applied to the drive shaft of the vehicle based on the accelerator pedal depression amount. The accelerator pedal depression amount corresponds to the torque request by the driver, and the torque T _{w_tgt} is a basis for torque correction by the vibration suppression correction unit 20. Therefore, hereinafter, the torque calculated by the basic required torque calculation unit 11 is referred to as basic required torque T _{w_tgt} .

The estimated drive wheel torque calculation unit 12 first calculates the intake air amount based on the signal from the intake air amount sensor 4 and also determines the rotational speed Ne (hereinafter referred to as the engine 2) of the engine 2 based on the signal from the crank angle sensor 5. Rotational speed) is calculated. Then, the estimated drive wheel torque calculation unit 12 calculates the torque T _{w_est} applied to the drive shaft of the vehicle based on the calculated intake air amount and the engine rotation speed. The estimated drive wheel torque calculation unit 12 estimates the torque generated in the engine 2 and applied to the drive shaft based on the intake air amount and the engine rotation speed. Hereinafter, this torque is referred to as estimated drive wheel torque T _{w_est} .

Based on the signal from the wheel speed sensor 6, the wheel speed calculation unit 13 determines the wheel speed V _{fl of} the left front wheel (hereinafter referred to as the left front wheel speed V _fl ), the wheel speed V _{fr of} the right front wheel (hereinafter, the right front wheel speed V). _fr ), wheel speed V _{rl of} the left rear wheel (hereinafter referred to as left rear wheel speed V _rl ) and wheel speed V _{rr of} the right rear wheel (hereinafter referred to as right rear wheel speed V _rr ).

  As shown in FIG. 2, the running resistance disturbance estimation unit 14 includes average processing units 31, 32, 33, subtractors 34, 35, differentiators 36, 37, low-pass filters 38, 39, and amplifiers 40, 41. With.

The average processing unit 31 calculates an average value of the left front wheel speed V _fl and the right front wheel speed V _fr .
The average processing unit 32 calculates an average value of the left rear wheel speed V _rl and the right rear wheel speed V _rr .
The average processing unit 33 calculates an average value of the left front wheel speed V _fl , the right front wheel speed V _fr , the left rear wheel speed V _rl, and the right rear wheel speed V _rr .

  The subtractor 34 calculates a value obtained by subtracting the calculated value of the average processing unit 33 from the calculated value of the average processing unit 31. The subtractor 35 calculates a value obtained by subtracting the calculated value of the average processing unit 33 from the calculated value of the average processing unit 32.

Differentiators 36 and 37 calculate differential values of the calculated values of the subtractors 34 and 35, respectively.
The low-pass filters 38 and 39 remove high-frequency components from the calculated values of the differentiators 36 and 37, respectively, and output them.

The amplifiers 40 and 41 respectively output the signals input from the low-pass filters 38 and 39 by multiplying the vehicle mass by M.
Therefore, the running resistance disturbance estimation unit 14 estimates the difference between the average value of the wheel speeds of the front wheels and the average value of the wheel speeds of the four wheels multiplied by the vehicle weight as the running resistance disturbance of the front wheels. The difference between the average value of the wheel speeds of the rear wheels and the average value of the wheel speeds of the four wheels multiplied by the vehicle weight is estimated as the disturbance resistance of the rear wheels.

As shown in FIG. 1, the steering angle calculation unit 15 calculates a steering wheel steering angle δ _n based on a signal from the steering angle sensor 7.
The vehicle speed calculation unit 16 calculates a traveling speed V of the vehicle (hereinafter referred to as a vehicle speed V) based on a signal from the vehicle speed sensor 8.

The road gradient acquisition unit 17 acquires the road gradient φ at the current position of the vehicle from the navigation device 9.
Based on the yaw rate γ acquired from the navigation device 9 and the vehicle speed V acquired from the vehicle speed calculation unit 16, the virtual turning radius calculation unit 18 is a virtual turning radius suitable for the vehicle to travel (hereinafter referred to as virtual turning radius). Ρ) (referred to as radius) is calculated using the following equation (1).

ρ = V / γ (1)
As shown in FIG. 3, the target load movement amount calculation unit 19 includes a cornering power calculation unit 51, a steering angle dependent parameter calculation unit 52, and a multiplier 53.

  The cornering power calculation unit 51 includes a front and rear wheel static load calculation unit 61, a road gradient influence term calculation unit 62, a static ground load change amount calculation unit 63, multipliers 64, 65, and 68, adders 66 and 67, and an amplifier 69. Prepare.

The front and rear wheel static load calculation unit 61 includes a constant output device 71 and amplifiers 72 and 73.
Constant output device 71 outputs a fixed value indicating the static load W _o of the vehicle. The static load _Wo of the vehicle is expressed by the following equation (2), where M is the mass of the vehicle and g is the acceleration of gravity.

W _o = M × g (2)
The amplifier 72 has the wheel base of the vehicle as L (see FIG. 4), the distance between the center of gravity of the vehicle and the rear wheel shaft as L _r (see FIG. 4), and the signal inputted from the constant output device 71 (L _r / L) Multiply and output. This output value corresponds to the static load _Wfo of the front wheel and is expressed by the following equation (3).

W _fo = (L _r / L) W _o (3)
The amplifier 73 sets the distance between the center of gravity of the vehicle and the front wheel shaft to L _f (see FIG. 4), and multiplies the signal input from the constant output device 71 by (L _f / L) and outputs it. This output value corresponds to the static load W _ro of the rear wheel and is expressed by the following expression (4).

W _ro = (L _f / L) W _o (4)
Accordingly longitudinal HanawaShizu load calculating section 61 outputs a value indicating wheel static load W _fo and Kowasei load W _ro.

The road gradient influence term calculation unit 62 includes a cosine function calculator 81, a sine function calculator 82, amplifiers 83 and 84, a subtracter 85, and an adder 86.
The cosine function calculator 81 inputs the road gradient φ from the road gradient acquisition unit 17 and performs a cosine function (cos) calculation. That is, the cosine function calculator 81 outputs cosφ.

The sine function calculator 82 inputs the road gradient φ from the road gradient acquisition unit 17 and performs a sine function (sin) calculation. That is, the sine function calculator 82 outputs sinφ.
The amplifier 83 sets the distance between the road surface and the center of gravity of the vehicle (hereinafter referred to as the height of the center of gravity) as h _cg (see FIG. 4), and the signal input from the sine function calculator 82 is multiplied by (h _cg / L _r ). And output. The amplifier 84 multiplies the signal input from the sine function calculator 82 by (h _cg / L _f ) and outputs the result.

The subtracter 85 calculates a value obtained by subtracting the output value of the amplifier 83 from the output value of the cosine function calculator 81. That is, the subtractor 85 outputs {cos φ− (h _cg / L _r ) sin φ}.
The adder 86 calculates a value obtained by adding the output value of the cosine function calculator 81 and the output value of the amplifier 83. That is, the adder 86 outputs {cos φ + (h _cg / L _f ) sin φ}.

Therefore, the road gradient influence term calculation unit 62 outputs {cosφ− (h _cg / L _r ) sinφ} and {cosφ + (h _cg / L _f ) sinφ}.
The static ground load change amount calculation unit 63 includes a sprung vibration model steady solution calculation unit 91 and front and rear wheel load change amount calculation units 92.

The sprung vibration model steady solution calculation unit 91 uses the sprung vibration model to calculate the vertical displacement xν of the vehicle body (see FIG. 4) and the pitch angle θ _p (see FIG. 4) around the pitching center of the vehicle body. For each, a value in the steady state is calculated.

  In the sprung vibration model, as shown in FIG. 4, the front wheel and the vehicle body of the vehicle and the rear wheel and the vehicle body are connected by a suspension in which a predetermined spring constant and a predetermined damping coefficient are set. Assuming that the vehicle vibrates with pitching, the vehicle state of the vehicle is expressed by a state equation.

And the state equation about the vertical displacement xν and the pitch angle θ _p of the vehicle body is expressed by the following equation (5). Here, xν ′ and xν ″ represent the first and second derivatives of xν, respectively. θ _p ′ and θ _p ″ indicate the first and second derivatives of θ _p , respectively. The _{a 1 ~ 4, b 1 ~} 4, p 1 ~ 3 are constants that are set in advance. ΔF _df and ΔF _dr are changes in translational force acting on the front wheel shaft and the rear wheel shaft, respectively. [Delta] T _w is the change amount of the estimated drive wheel torque _T w_est.

When the vehicle is in a steady state, xν ′, xν ″, θ _p ′, and θ _p ″ are 0. Therefore, in equation (5), xν ′, xν ″, θ _p ′, θ _p substituting 0 into '', the following equation (6), as shown in (7), is obtained and the stationary solution theta _{p_s} of stationary solutions Xnyu _{_s} and theta _p of Xnyu.

Sprung vibration model constant solution calculating section 91 thus has the formula (6) with (7), the stationary solution Xnyu _{_s,} calculates the theta _{p_s.}
Front and rear wheel load variation calculating unit 92, Equation (8), with (9), calculates the front wheel static ground load change amount [Delta] W _{f_s,} the rear wheel static ground load change amount [Delta] W _{r_s.} Here, K _sf is the spring constant of the suspension on the front wheel side, and K _sr is the spring constant of the suspension on the rear wheel side (see FIG. 4).

Thus static ground load change amount calculating unit 63, as shown in FIG. 3, and outputs a static ground load change amount [Delta] W _{r_s} front wheel static ground load change amount [Delta] W _{f_s} and rear wheels.
The multiplier 64 calculates a multiplication value of the output value from the amplifier 72 and the output value from the subtracter 85. That is, the multiplier 64 outputs W _fo {cos φ− (h _cg / L _r ) sin φ}. This value corresponds to the ground load applied to the front wheels along the direction perpendicular to the road surface traveling on the road surface having the road gradient φ.

The multiplier 65 calculates a multiplication value of the output value from the amplifier 73 and the output value from the adder 86. That is, the multiplier 65 outputs W _ro {cos φ + (h _cg / L _f ) sin φ}. This value corresponds to the ground contact load applied to the rear wheel along the road surface vertical direction while traveling on the road surface of road gradient φ.

The adder 66 calculates an addition value between the output value from the multiplier 64 and the static ground load change amount ΔW _{f — s} from the static ground load change amount calculation unit 63. This value is the total value W _f of the front wheel static ground load with the load movement caused by the steady driving torque added to the ground load of the front wheel corresponding to the road gradient φ in the steady state (hereinafter, the front wheel static load). corresponds to) that the ground load W _f.

The adder 67 calculates an addition value between the output value from the multiplier 65 and the static ground load change amount ΔW _{r — s} from the static ground load change amount calculation unit 63. This value is a total value W _r (hereinafter, referred to as “rear wheel static ground load”) in which the load movement caused by the steady driving torque is added to the ground load of the rear wheel corresponding to the road gradient φ in the steady state. This corresponds to the rear wheel static ground load _Wr ).

Multiplier 68 calculates a multiplication value of front wheel static ground load W _f from adder 66 and rear wheel static ground load W _r from adder 67.
Amplifier 69 outputs a signal inputted from the multiplier 68 C _w ² multiplied by. C _w is a load dependent coefficient of cornering power. That is, the amplifier 69 outputs (C _w ² × W _f × W _r ).

The front wheel cornering power _Cpf and the rear wheel cornering power _Cpr are expressed by the following equations (10) and (11), respectively.
C _pf = C _w W _f (10)
C _pr = C _w W _r (11)
Accordingly, the cornering power calculation unit 51 outputs a value C _pf C _pr obtained by multiplying the front wheel cornering power C _pf by the rear wheel cornering power C _pr .

  Next, the steering angle dependent parameter calculation unit 52 includes amplifiers 101, 104, and 110, an absolute value calculator 102, a multiplier 103, a constant output unit 105, a subtractor 106, a square calculator 107, a zero division preventer 108, and a divider. 109.

The amplifier 101 sets the steering gear ratio to R _s , multiplies the steering wheel steering angle δ _n input from the steering angle calculation unit 15 by (1 / R _s ), and outputs the result as the steering angle δ of the front wheels.
The absolute value calculator 102 calculates and outputs the absolute value of the output value from the amplifier 101.

The multiplier 103 calculates a multiplication value of the absolute value of the steering angle δ and the virtual turning radius ρ from the virtual turning radius calculation unit 18.
The amplifier 104 multiplies the output value from the multiplier 103 by (1 / L) and outputs the result.

The constant output unit 105 outputs a preset constant 1.
The subtractor 106 calculates a value obtained by subtracting the output value from the constant output unit 105 from the output value from the amplifier 104. That is, the subtractor 106 outputs (ρ | δ | / L−1).

The square calculator 107 receives the vehicle speed V from the vehicle speed calculator 16 and performs a square calculation. That is, the square calculator 107 outputs the V ^2.
The zero division preventer 108 performs zero division prevention on the output value V ² from the square calculator 107.

The divider 109 outputs a value obtained by dividing the output value from the subtractor 106 by the output value from the zero division preventer 108.
The amplifier 110 multiplies the output value from the divider 109 by a coefficient k expressed by the following equation (12) and outputs the result.

k = −2L ² / MC _w (12)
Therefore, the steering angle dependent parameter calculation unit 52 outputs {2L ² (1-ρ | δ | / L) / MC _w V ² }.

The multiplier 53 calculates and outputs a multiplication value of the output value from the cornering power calculation unit 51 and the output value from the steering angle dependent parameter calculation unit 52.
As described above, the target load movement amount calculation unit 19 outputs a value represented by the following expression (13) as the target load movement amount Δ.

Δ = (2L ² C _pf C _pr / MC _w V ² ) × (1−ρ | δ | / L) (13)
The turning radius ρ of the vehicle is expressed by the following formula (14).

Equation (14) shows that the value of the turning radius with respect to increase / decrease in vehicle speed with a constant rudder angle depends on the value of (L _f C _pf −L _r C _pr ). Specifically, when (L _f C _pf −L _r C _pr ) is smaller than 0, the turning radius ρ increases as the vehicle speed V increases, that is, understeer, and (L _f C _pf −L _r When C _pr ) is greater than 0, the turning radius ρ decreases as the vehicle speed V increases, that is, oversteer. That is, the steering characteristic can be controlled using (L _f C _pf −L _r C _pr ).

Further, (L _f C _pf −L _r C _pr ) is expressed by the following equation (15) using equations (10) and (11).
_{(L f C pf -L r C} pr) = C w (L f W f -L r W r) ··· (15)
Therefore, (L _f W _f −L _r W _r ) in the equation (15) is expressed by the following equation (16).

As can be understood by comparing Expression (13) and Expression (16), the target load movement amount calculation unit 19 calculates (L _f W _f −L _r W _r ) as the target load movement amount Δ. ing.
Next, as shown in FIG. 1, the vibration suppression correction unit 20 includes a sprung vibration model calculation unit 121, subtractors 122, 127, 130, an integrator 123, amplifiers 124, 125, 128, 129, and an adder / subtractor 126. .

The sprung vibration model calculation unit 121 calculates the state quantity x = (xν, xν ′, θ _p , θ _p ′) by the above equation (5). The sprung vibration model calculation unit 121 calculates the estimated load movement amount y _s by the following equation (17) using the state quantity x calculated by the above equation (5). Here, K _sf is the spring constant of the suspension on the front wheel side, K _sr is the spring constant of the suspension on the rear wheel side, C _sf is the damping coefficient of the suspension on the front wheel side, and C _sr is the damping coefficient of the suspension on the rear wheel side. (See FIG. 4).

Subtractor 122 calculates the output value from the target load shift amount correcting unit 21, a value obtained by subtracting the estimated load shift amount y _s from sprung vibration model calculating unit 121, i.e. the model output error.
The integrator 123 integrates the output error from the subtractor 122. The amplifier 124 multiplies the integral value input from the integrator 123 by a preset integral gain K _i and outputs it. Therefore, the vibration damping correction unit 20 is a type 1 servo system.

The amplifier 125 multiplies the state quantity x output from the sprung vibration model calculation unit 121 by a preset state feedback gain K _s and outputs the result.
The adder / subtractor 126 adds the output value from the amplifier 124 and the running resistance disturbance from the running resistance disturbance estimation unit 14. Further, the adder / subtractor 126 calculates a value obtained by subtracting the output value from the amplifier 125 from the added value, and outputs the subtracted value to the sprung vibration model calculation unit 121 and the subtractor 127. The output value of the adder / subtractor 126 is an absolute value of driving torque (hereinafter referred to as corrected driving torque) corrected in view of the running resistance disturbance and the state quantity x estimated to follow the target load movement amount.

The subtractor 127 subtracts the correction drive torque from the adder / subtractor 126 from the torque T _{w_est} from the estimated drive wheel torque calculation unit 12 to calculate a relative drive torque correction value.
The amplifier 128 sets the reduction ratio (final gear ratio) in the final reduction gear as R _d , and outputs the output value from the subtractor 127 multiplied by (1 / R _d ). The amplifier 129 _multiplies the basic required torque T _{w — tgt} from the basic required torque calculation unit 11 by (1 / R _d ) and outputs the result.

The subtractor 130 calculates a value obtained by subtracting the output value from the amplifier 128 from the output value from the amplifier 129.
The output of the subtractor 130 is the corrected required torque, and the electronic control unit 1 uses the throttle motor (not shown) that changes the opening of the throttle valve based on the corrected required torque, and the fuel in each cylinder. The engine 2 is operated by controlling various actuators such as an ignition plug (not shown) for igniting and an injector (not shown) for injecting fuel into each cylinder.

As shown in FIG. 5, the target load movement amount correction unit 21 includes a vehicle speed correction factor calculation unit 141, a shift correction factor calculation unit 142, a vehicle weight correction factor calculation unit 143, and multipliers 144, 145, and 146.
Is provided.

Speed correction factor calculation unit 141 is provided with a one-dimensional map M1 the value of the vehicle speed correction factor F _v where the vehicle speed V as a parameter is set in advance. The vehicle speed correction factor calculation unit 141, based on the input vehicle speed V, and calculates a vehicle speed correction factor F _v by reference to one-dimensional map M1. Incidentally, the vehicle speed correction factor F _v of the one-dimensional map M1 is 0 is less than (2km / h in this embodiment) first determination vehicle speed from 0 km / h, in the second determination vehicle speed (the present embodiment from the first determination vehicle speed When the speed is less than 10 km / h), the speed is increased in proportion to the vehicle speed V, and is set to 1 at the second judgment vehicle speed or higher.

The shift correction factor calculation unit 142 includes a one-dimensional map M2 in which the value of the shift correction factor F _{s using} the shift position as a parameter is preset. Then, the shift correction factor calculation unit 142 refers to the one-dimensional map M2 based on the detection result of the shift position sensor 151 that detects the shift position of a transmission (not shown) mounted on the vehicle, thereby shifting the shift correction factor F. Calculate _s . The shift correction factors F _s of one-dimensional map M2 in the case of 0, R range in the case of P-range and N-range is -1, is set to be 1 in the case of D-range and S range ing.

Vehicle weight correction factor calculation unit 143, based on the road gradient φ input from the road gradient obtaining section 17, the entered height h 'from the vehicle height sensor 152 for detecting the height of the vehicle, vehicle weight correction factor F _h Is calculated using the following equation (18). Here, k is a spring constant of the vehicle. h is the height of the vehicle in a state where a heavy object is not mounted. M is the weight of the vehicle when no heavy object is mounted.

F _h = 1+ {k × (h′−h) / (M · g · cos φ)} (18)
Equation (18) is based on the fact that the weight m of the heavy object mounted on the vehicle (that is, the increase in vehicle weight) m is calculated by the following equation (19).

m = k × (h′−h) / (g · cos φ) (19)
The multiplier 144 calculates and outputs a multiplication value of the target load movement amount Δ from the target load movement amount calculation unit 19 and the vehicle speed correction factor F _v from the vehicle speed correction factor calculation unit 141.

The multiplier 145 calculates and outputs a multiplication value of the output value from the multiplier 144 and the shift correction factor F _s from the shift correction factor calculation unit 142.
The multiplier 146 calculates and outputs a multiplication value of the output value from the multiplier 145 and the vehicle weight correction factor F _h from the vehicle weight correction factor calculation unit 143.

Thus the target load shift amount correcting unit 21, the target load shift amount delta, outputs a value obtained by multiplying the vehicle speed correction factor F _v and the shift correction factor F _s and the vehicle weight correction factor F _h.
In the electronic control device 1 configured as described above, the basic required torque calculation unit 11 calculates the basic required torque T _{w_tgt} based on the accelerator pedal operation by the driver. The target load movement amount calculation unit 19 calculates the target load movement amount Δ so that the vehicle travels stably, and the sprung vibration model calculation unit 121 estimates the estimated load movement amount y _s of the vehicle. The vibration damping correcting unit 20, the estimated load shift amount y _s corrects the basic request torque T _{W_tgt} so as to follow the target load shift amount delta.

In this way, the electronic control unit 1 can stabilize the steering characteristics when the vehicle is traveling.
The target load movement amount is expressed by the above equation (16). That is, the target load movement amount changes so as to increase as the traveling speed of the vehicle (hereinafter also referred to as vehicle speed) decreases. For this reason, for example, when the vehicle is started by turning the steering wheel in a shape close to a stationary stop from a stationary state, the target load movement amount becomes a very large value because the vehicle speed is low.

  On the other hand, the target load movement amount correction unit 21 sets a second determination vehicle speed (10 km / h in the present embodiment) that is set in advance to determine whether or not the vehicle is traveling at a low vehicle speed V. If it is less, the target load movement amount Δ is corrected so as to be smaller than the target load movement amount Δ calculated by the target load movement amount calculation unit 19.

  Thus, for example, when the target load movement amount Δ is set to be a preload when the vehicle is started by turning the steering wheel in a form close to a stationary stop from a stationary state, the target load movement amount Δ is very large. Although it is a value, the target load movement amount correction unit 21 corrects the target load movement amount Δ to be small. For this reason, the degree to which the driving force is reduced can be reduced, and the situation where the driving force is reduced immediately after the start and the vehicle does not go forward in a state where the vehicle speed is not so much generated causes the driver to feel uncomfortable. Occurrence can be suppressed.

  In addition, when the target load movement amount Δ is set to a positive value so as to correct to the oversteer side when the shift position is set to the R range and the vehicle is understeering while turning in the back, if the target load movement amount Δ is set to a positive value, the preload is set. Control is performed to reduce the driving force. However, since the steered wheel is a rear wheel in reverse travel, it is necessary to use a rear load to bring the steering characteristic to the oversteer side, which adversely deteriorates the steering characteristic.

  On the other hand, the target load movement amount correction unit 21 has a positive / negative sign based on the shift position when the shift position is in the R range, compared to the case where the shift position is in the D range or S range. The target load movement amount Δ is corrected so that is reversed.

  As a result, the target load movement amount Δ can be set in consideration of whether the steered wheel is the front wheel or the rear wheel. Therefore, calculation of the target load movement amount Δ assuming forward traveling is performed during backward traveling. Thus, the stability of the steering characteristics during reverse travel can be improved.

  Further, the target load movement amount is expressed by the following equation (20). Equation (20) is simply calculated without considering the road gradient and the load movement due to acceleration / deceleration. However, the influence of the weight of the vehicle is the same even when the road gradient and load movement are taken into account.

That is, the target load movement amount Δ changes so as to increase as the vehicle weight increases.
On the other hand, the target load movement amount correction unit 21 corrects the target load movement amount Δ based on the vehicle weight so that the target load movement amount Δ increases or decreases at the same rate as the vehicle weight increases or decreases.

Thus the electronic control unit 1, it is possible to perform control so that the actual estimated load movement amount to the target load shift amount Δ corresponding to the vehicle weight y _s to follow, desired steering characteristics by the vehicle weight can be obtained The stability of steering characteristics can be improved.

  As described above, in the electronic control device 1, the target load movement amount correction unit 21 corrects the target load movement amount Δ calculated by the target load movement amount calculation unit 19 based on the vehicle speed V, the shift position, and the vehicle weight. Thus, the electronic control unit 1 can appropriately change the target load movement amount Δ in accordance with changes in the vehicle speed V, the shift position, and the vehicle weight, and the vehicle state of the vehicle state caused by the vehicle speed V, the shift position, and the vehicle weight can be changed. The driving force can be appropriately controlled according to the change.

In the embodiment described above, the electronic control device 1 is the vehicle control device in the present invention, the basic required torque calculation unit 11 is the basic driving force calculation means in the present invention, and the target load movement amount calculation unit 19 is the target load movement amount in the present invention. The calculation means, the sprung vibration model calculation section 121 is the load movement amount estimation means in the present invention, the vibration suppression correction section 20 is the driving force correction means in the present invention, and the target load movement amount correction section 21 is the load movement amount correction means in the present invention. The basic required torque T _{w_tgt} is the basic required driving force in the present invention, and the second determination vehicle speed is the low speed determination speed in the present invention.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, As long as it belongs to the technical scope of this invention, a various form can be taken.

  DESCRIPTION OF SYMBOLS 1 ... Electronic controller, 11 ... Basic required torque calculation part, 19 ... Target load movement amount calculation part, 20 ... Damping correction part, 21 ... Target load movement amount correction part, 121 ... Sprung vibration model calculation part

Claims (1)

A vehicle control device (1) mounted on a vehicle for controlling the driving force of the vehicle,
Basic driving force calculating means (11) for calculating a basic required driving force which is a driving force required by the driver for the vehicle based on an accelerator pedal operation by the driver;
The target load movement amount is Δ, the wheel base of the vehicle is L, the cornering power of the front wheels is C _pf , the cornering power of the rear wheels is C _pr , the mass of the vehicle is M, the load dependence coefficient of the cornering power is C _w , the vehicle speed Is the virtual turning radius ρ, the steering angle of the front wheels is δ, and “Δ = (2L ² C _pf C _pr / MC _w V ² ) × (1−ρδ / L)” A target load movement amount calculating means (19) for calculating;
Load movement amount estimation means (121) for estimating a front and rear wheel load movement amount that is a load movement amount between a front wheel and a rear wheel of the vehicle ;
Driving force correction means (20) for correcting the basic required driving force so that the front and rear wheel load movement amount estimated by the load movement amount estimation means follows the target load movement amount;
Running speed of the vehicle, based on at least one shift position and weight, Bei give a load movement amount correction means for correcting the target load shift amount calculated (21) by the target load movement amount calculating means,
The load movement amount correction means includes:
When correcting the target load movement amount based on the travel speed, when the travel speed is lower than a low speed determination speed set in advance to determine whether the vehicle is traveling at a low speed The target load movement amount is corrected so as to be smaller than the target load movement amount calculated by the target load movement amount calculation means,
When correcting the target load movement amount based on the shift position, when the shift position is in the R range, the sign of the sign is reversed compared to the case where the shift position is in the D range or S range. Correct the target load movement amount so that
When the target load movement amount is corrected based on the weight, the target load movement amount is corrected so that the target load movement amount increases or decreases according to the increase or decrease of the weight. .

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