JP5699571B2 - Vehicle control device - Google Patents

Description

  The present invention relates to an apparatus for controlling vehicle behavior such as turning stability, and more particularly to an apparatus configured to optimize a stability factor that greatly affects the behavior of the vehicle.

  Stability factors are known as factors that greatly affect vehicle behavior. Assuming a steady turning condition without acceleration or deceleration, the vehicle stability factor is the inertial mass, wheelbase, front and rear wheel cornering power (cornering force), the center of gravity between the vehicle and the front and rear axles. It is expressed by a distance or can be obtained based on the actual steering angle, wheelbase, lateral acceleration, and vehicle speed. It is known that this can be extended to a turning state with driving or braking, and a term obtained by multiplying the longitudinal acceleration by a coefficient and a term obtained by multiplying the square of the longitudinal acceleration by a coefficient are stored in a state without acceleration / deceleration. It is given by a quadratic expression that is added to the stability factor. These coefficients are due to load movement by driving or braking, toe angle change and compliance, and due to cornering characteristics of tires on which driving force and braking force act.

  The yaw rate and turning radius during turning vary depending on the stability factor, and therefore the stability factor is an important parameter that governs the steering characteristics of the vehicle. The stability factor is basically determined based on the structure of the vehicle and the characteristics of the tires, but the cornering power of the front and rear wheels may change depending on the load applied to the front and rear wheels, deterioration over time, and so-called expansion. In the stability factor determined, the coefficient of the primary term and the coefficient of the secondary term of the longitudinal acceleration may not be as designed.

  Conventionally, an attempt has been made to correct the stability factor for vehicle behavior control. For example, in Patent Document 1, when the difference between the designed stability factor and the actual stability factor is large, A method is described in which a stability factor used for vehicle behavior control and driving force control is replaced with an actual stability factor. That is, in the method described in Patent Document 1, steady circular turning is performed when the vehicle is shipped from a factory, and various characteristics at that time are measured, and an actual stability factor is based on the data obtained by the measurement. Is calculated, the actual stability factor is compared with the stability factor stored in advance, and the stability factor is replaced as necessary based on the result of the comparison.

  Further, Patent Document 2 describes a system configured to suppress the influence of driver operation disturbance and road surface disturbance to stabilize the behavior of the vehicle. That is, the system described in Patent Document 2 pays attention to the fact that the stability factor is affected by the ground contact load of the front and rear wheels, and determines the stability factor from the cornering power of the front and rear wheels and the center of gravity of the vehicle. The difference between the distance and the product (that is, the moment based on the cornering power of the front and rear wheels) corrects the axle torque so that it follows the target value.

JP 2006-131052 A JP 2005-256636 A

  The method described in Patent Document 1 is a method of obtaining a characteristic value of a vehicle while traveling with a predetermined steering pattern at a constant vehicle speed, and calculating an actual stability factor based on the characteristic value. Therefore, the stability factor is assumed assuming steady circular turning, but if the stability factor is used to determine the driving force or longitudinal acceleration during circular turning with driving or braking, braking or driving is considered. Therefore, an appropriate driving force or longitudinal acceleration or a correction value thereof cannot be obtained.

  Further, in the system described in Patent Document 2, since the axle torque is corrected so that the moment due to the cornering power of the front and rear wheels is brought close to the target value among the factors that determine the stability factor, there is no driving or braking. For steady circle turning, the steer characteristics may be improved. However, in the case of circular turning accompanying driving or braking, control based on the so-called extended stability factor is necessary, and it is preferable to make the extended stability factor appropriate. In the system described in 2), it is difficult to make the expanded stability factor suitable for the actual situation and to improve the behavior characteristics when turning with driving and braking, and there is room for developing new technology. was there.

  The present invention has been made paying attention to the above technical problem, and a control device capable of making the stability factor suitable for an actual vehicle so as to stably perform turning traveling with driving and braking. Is intended to provide.

In order to achieve the above object, the invention of claim 1 is a vehicle for obtaining a stability factor extended to a turn with acceleration / deceleration for the vehicle based on data obtained when the vehicle actually turns. in the control device, Rutotomoni determined at least three of the longitudinal acceleration of the different values at which the vehicle is actually cornering, the three so that the absolute value of the difference between the longitudinal acceleration mutual is greater than a predetermined reference value the three and pressurized deceleration detecting means for determining a longitudinal acceleration, a stability factor calculating means for their longitudinal acceleration determining an actual stability factor at the traveling obtained, the stability factor during turning with acceleration in Is equal to the sum of a term obtained by multiplying the square of the longitudinal acceleration by a coefficient, a term obtained by multiplying the longitudinal acceleration by another coefficient, and a constant term. Substituting the longitudinal acceleration obtained by the detection means and the actual stability factor obtained by the stability factor calculation means to establish a ternary simultaneous linear equation, and the ternary simultaneous linear equations are converted into the coefficients and other coefficients. And coefficient calculation means for obtaining the respective values of the constants of the constant term, and the coefficient obtained by the coefficient calculation means and other coefficients and constants of the constant term are substituted into the relational expression to make a turn with acceleration and deceleration. Update means for updating the definition formula of the extended stability factor, and the elapsed time until the longitudinal acceleration having a difference larger than the reference value with respect to the longitudinal acceleration that has already been obtained among the three longitudinal accelerations is determined in advance. Longitudinal acceleration in which the absolute value of the difference from the longitudinal acceleration that has already been obtained becomes greater than the reference value when the specified time has elapsed And is characterized in that it comprises a longitudinal acceleration generating means for generating said vehicle.

According to a second aspect of the present invention, in the first aspect of the invention, the elapsed time includes a time at which counting is started from the time when the definition formula of the stability factor is updated by the updating means. It is a control device.

  The stability factor expanded to turning with driving or braking can be expressed by a quadratic expression of longitudinal acceleration, and according to the present invention, the vehicle actually travels with each coefficient and constant term in the secondary. From the simultaneous equations based on the longitudinal acceleration and the actual stability factor, and substituting the obtained value into the above quadratic formula to update the stability factor definition formula extended to turning with driving or braking . Therefore, according to the present invention, a stability factor suitable for the vehicle can be obtained, and accordingly, the steer characteristic, the driving force control, etc. can be made suitable, and the drivability can be improved.

In particular, phase since each other make a simultaneous equation using the actual stability factor of the longitudinal acceleration and for each of the longitudinal acceleration a difference exceeding the reference value, the resulting coefficients or defining equation, it is assumed good precision Can do.

Furthermore, since the resulting actively longitudinal acceleration absolute value of the difference between the longitudinal acceleration that is sought already exceeds the reference value, it is possible to avoid or suppress the delay in updating the defining equation.

It is a flowchart for demonstrating an example of the control performed with the control apparatus of this invention. It is a flowchart for demonstrating the other example of the control performed with the control apparatus of this invention. It is a schematic diagram which simplifies and shows the drive system and control system of the vehicle which can be made into object by this invention.

  The present invention is an apparatus configured to optimize the longitudinal acceleration or driving force of a vehicle using a stability factor, and the vehicle includes a front-wheel drive vehicle using an internal combustion engine, a motor, or the like as a power source. It may be a rear wheel drive vehicle or a four wheel drive vehicle. FIG. 3 is a block diagram showing an example of a drive system and a control system of a two-wheel drive vehicle that drives rear wheels by an engine. A transmission 2 is connected to the output side of the engine 1, and the power output from the transmission 2 is distributed and transmitted to the left rear wheel Rl and the right rear wheel Rr via a differential (final reduction gear) 3. It is configured. The left and right front wheels Fl, Fr are steered wheels, and provided with a wheel speed sensor 4 for detecting the rotational speed (rotation speed) of each of the four wheels Fl, Fr, Rl, Rr, and the yaw generated in the vehicle body Is provided.

  Furthermore, a vehicle electronic control unit (vehicle ECU) 6 mainly including a microcomputer that performs overall control of the entire vehicle is provided. The vehicular electronic control device 6 is mainly configured to control the driving force, and includes detection signals output from the wheel speed sensor 4 and the yaw rate sensor 5 described above, longitudinal acceleration, lateral acceleration, steering angle, accelerator opening. Various detection signals such as speed, brake signal, road surface friction coefficient, etc. are input, and the vehicle weight, wheelbase, distance from the center of gravity of the vehicle body to the front and rear wheel shafts (distance between the front and rear wheels), front and rear wheel cornering stiff Data such as ness (cornering force) and other preset constants and maps are stored in the vehicle electronic control device 6. Then, the vehicle electronic control device 6 calculates the target stability factor, the target driving force, the target longitudinal acceleration, and the like based on these detection signals, data, and maps, and outputs the necessary control signals. It is configured. An engine / transmission electronic control unit (engine / TM ECU) 7 mainly including a microcomputer that controls the engine 1 and the transmission 2 when the control signal is input is provided.

  The control device according to the present invention is so-called extended to obtain a coefficient for determining the stability factor based on the longitudinal acceleration when the longitudinal acceleration changes during turning in order to optimize the steering characteristic of the vehicle. The stability factor is set to a value corresponding to the actually measured value. An example of the control is shown in the flowchart of FIG. The routine shown in FIG. 1 is repeatedly executed at short time intervals. First, it is determined whether or not the vehicle is turning (step S1). This can be determined based on, for example, the detected lateral acceleration, and a threshold value for the lateral acceleration for turning determination is prepared in advance, and the detected lateral acceleration exceeds the threshold value. In this case, it may be determined that the vehicle is turning. If a negative determination is made in step S1 because the vehicle is not turning, this routine is temporarily terminated without performing any particular control. On the other hand, if the vehicle is turning and the lateral acceleration is large and the determination is affirmative in step S1, the longitudinal acceleration Gxcurr of the vehicle based on the current accelerator operation by the driver is the i-th acceleration. (Step S2). In FIG. 1, Gx [i] is a longitudinal acceleration storage variable, and initially Gx [i] = O. Further, the longitudinal acceleration Gxcurr may be detected by an acceleration sensor, or the driving force is obtained from the accelerator operation amount or the corresponding throttle opening, and is calculated from the longitudinal force calculated from the driving force and the vehicle body weight. There may be.

Next, the storage number i is determined (step S3). That is, immediately after starting the routine of FIG. 1, it is determined whether or not “i = 1”. If the first longitudinal acceleration Gxcurr is obtained, an affirmative determination is made in step S3. In this case, the actual stability factor is calculated from the lateral acceleration Gyreal at that time, the vehicle speed V, and the actual steering angle δ. khcurr is obtained and stored (step S4). That is, “kh [i] = khcurr” is set. The actual stability factor khcurr is
khcurr = (δ / LGyreal) − (1 / V ² ) (L: wheelbase)
Calculated with

  After storing the actual stability factor khcurr, it is determined whether or not the storage number i is “3” (step S5). Since the storage number i increases in order, a negative determination is made in step S5 at the beginning of storage. In this case, the storage variable is increased by one (step S6) and the process returns. If the vehicle changes to straight running when making the determination in step S1 of the subsequent cycle, a negative determination is made in step S1, and in that case, the process returns without performing any particular control. On the contrary, if the vehicle is turning, the determination in step S1 is affirmative. Therefore, the process proceeds to step S2 again, and the vehicle longitudinal acceleration Gxcurr based on the current accelerator operation by the driver is i. Stored as the second acceleration.

  In step S3, it is determined whether or not the storage number i is “1”. In this case, since the storage number i is incremented by one in step S6 described above and becomes “i + 1”, in step S3. Judgment is negative. As a result, the process proceeds to step S7, where it is determined whether or not the absolute value of the difference between the longitudinal acceleration Gx [i] stored this time and the longitudinal acceleration Gx [i-1] stored last time is greater than a predetermined reference value X. The This reference value X is used to determine whether or not there is a substantial change in the longitudinal acceleration Gx. As will be described later, a three-way simultaneous linear equation for obtaining a coefficient in an equation defining an extended stability factor is used. The longitudinal acceleration Gx that is sufficiently different to be obtained can be determined in advance as a value that can be determined, and can be a value in a range of change in the longitudinal acceleration Gx that occurs in a relatively short time. This is because if the reference value X is a large value, it takes a long time to store the (i + 1) th longitudinal acceleration Gx.

  Therefore, if the absolute value of the difference between the longitudinal accelerations Gx is equal to or less than the reference value X and a negative determination is made in step S7, the process returns without performing any particular control. On the other hand, if the absolute value of the difference between the longitudinal acceleration Gx exceeds the reference value X and a positive determination is made in step S7, it is determined whether or not the storage number i is “2”. (Step S8). After step S6 described above is executed for the first time, since “i + 1 = 2”, the determination is affirmative in step S8.

  If the determination in step S8 is affirmative, the process proceeds to step S4 described above, and the actual stability factor khcurr is obtained from the lateral acceleration Gyreal at the present time, the vehicle speed V, and the actual steering angle δ, and stored. That is, “kh [i] = khcurr” is set. In this case, “i” is “2”. The calculation formula for obtaining the actual stability factor is as described above. Subsequent to the control in step S4, the process proceeds to step S5, where it is determined whether or not the storage number i is “3”. As described above, the number i of storages increases in order, but if it is the second time in the determination in step S5, “i = 2”, so a negative determination is made in step S5. (Step S6) and return.

  If the vehicle changes to straight running when performing the determination in step S1 in the cycle executed again, a negative determination is made in step S1, and in that case, the process returns without performing any particular control. On the contrary, if the vehicle is making a turn, the determination in step S1 is affirmative. Therefore, the process proceeds to step S2 and step S3 again, and the vehicle longitudinal acceleration based on the current accelerator operation by the driver is the same as described above. Gxcurr is stored as the i-th acceleration, and whether the stored number i is “1” or not is determined as a negative determination result. Accordingly, the process proceeds to step S7 and the current longitudinal acceleration Gx [i] and the previous storage are stored. It is determined whether or not the absolute value of the difference between the longitudinal acceleration Gx [i-1] and the reference acceleration X is greater than a predetermined reference value X. If there is no difference exceeding the reference value X, the process returns without performing any particular control. On the contrary, if it is determined positively that a difference exceeding the reference value X occurs, Proceeding to step S8 described above, it is determined whether or not the storage number i is "2". Since “i + 1 = 3” after step S6 described above is executed twice, a negative determination is made in step S8.

  As described above, since the longitudinal acceleration Gx is detected so as to obtain a ternary simultaneous linear equation for obtaining a coefficient in the quadratic equation defining the extended stability factor, the current longitudinal acceleration Gx [i ] Must be different from the first longitudinal acceleration Gx [i-2] by more than the reference value X. Therefore, if a negative determination is made in step S8, the current longitudinal acceleration Gx It is determined whether or not the absolute value of the difference between [i] and the first longitudinal acceleration Gx [i-2] exceeds the reference value X (step S9). If a negative determination is made in step S9, the current stored longitudinal acceleration Gx is not sufficient to obtain the ternary simultaneous linear equation for obtaining the above coefficient, and therefore control is performed in particular. Return without. On the contrary, since the absolute value of the difference between the current longitudinal acceleration Gx [i] and the first longitudinal acceleration Gx [i-2] exceeds the reference value X, a positive determination is made in step S9. If YES, the process proceeds to step S4 and step S5 described above in order. That is, “kh [i] = khcurr” is set. In this case, “i” is “3”. Further, it is determined whether or not the storage number i is “3”.

In this case, since the number i stored is already “3”, a positive determination is made in step S5. That is, since three actual stability factors kh [1], kh [2], kh [3] and longitudinal accelerations Gx1, Gx2, Gx3 have already been obtained, the following ternary simultaneous linear equations are established.
kh1 = kh'0 + kh'1Gx1 + kh'2Gx1 ²
kh2 = kh'0 + kh'1Gx2 + kh'2Gx2 ²
kh3 = kh'0 + kh'1Gx3 + kh'2Gx3 ²

Therefore, if the determination in step S5 is affirmative, the constant term kh0, the first-order coefficient kh1 and the second-order term defining the expanded stability factor based on the ternary simultaneous linear equation described above are used. A coefficient kh2 is calculated (step S10). Then, the following quadratic equation defining the extended stability factor kh: kh = kh0 + kh1 · Gx + kh2 · Gx ²
The values of the coefficients kh0, kh1, and kh2 are updated to the values calculated in step S10 (step S11). That is, kh0 = kh′0, kh1 = kh′1, and kh2 = kh′2 are replaced.

  After updating the quadratic equation that defines the expanded stability factor kh in this way, the stored number i is reset to zero (step S12), and then the stored number i is incremented by one in step S6 described above, and the process returns.

  The control device according to the present invention updates the quadratic equation defining the extended stability factor kh based on the actually measured longitudinal acceleration Gx as described above. That is, the actual stability factor kh [i] is obtained based on the lateral acceleration and vehicle speed obtained in the actually traveling vehicle and the actual steering angle, and the longitudinal acceleration Gx at that time is obtained, and these values are used. A three-dimensional simultaneous linear equation using the longitudinal acceleration Gx and the actual stability factor which are different from each other due to three unknowns, and solving the ternary simultaneous linear equation to obtain a coefficient value, The definition formula of the stability factor using the coefficient is obtained. Therefore, the definition formula corrects a difference from the design value such as individual differences of vehicles and changes in characteristics over time, and an appropriate stability factor can be obtained for each vehicle. In particular, in the control device according to the present invention, when the three-dimensional simultaneous linear equation is obtained, the longitudinal acceleration Gx having a different value exceeding the reference value X is used. The definition formula reflects actual vehicle characteristics or individual differences, and each coefficient and definition formula can be updated with high accuracy. As a result, by controlling the driving force at the time of turning to be the longitudinal acceleration obtained by the definition formula, it becomes possible to perform a stable turning and improve drivability.

  As described above, when the simultaneous equations for obtaining the respective coefficients are established, the longitudinal acceleration Gx [i] and the actual stability factor kh [i] are subject to disturbances in order to improve the accuracy of the calculated values. In addition to being not included and due to the accelerator operation of the driver, it is preferable that there is a certain difference between them. Therefore, in the specific example mentioned above, it is comprised so that the longitudinal acceleration Gx with the difference exceeding the reference value X may be employ | adopted. In other words, when the change in the longitudinal acceleration Gx based on the driver's operation does not exceed the reference value X, the above simultaneous equations cannot be established, and the extended stability factor definition formula is extended over a long period of time. May not be updated. Therefore, when the variation in the accelerator operation of the driver is small and the change in the longitudinal acceleration Gx does not exceed the reference value X over a predetermined time, the longitudinal acceleration Gx is generated by the control, and the aforementioned coefficient is set as an unknown. You may comprise so that a linear equation may be obtained.

  FIG. 2 is a flowchart for explaining an example thereof. In the routine shown in FIG. 1, the step of counting time, the step of determining the counted time, and the longitudinal acceleration Gx are given by control. And a step. Therefore, a different part from the routine shown in FIG. 1 is demonstrated, and about the same part as the routine shown in FIG. 1, the same step number as FIG. 1 is attached | subjected to FIG. 2, and the description is abbreviate | omitted. The routine shown in FIG. 2 is repeatedly executed every predetermined short time, and first, the elapsed time from the last update of the expanded stability factor definition formula is counted up (step S0). Next, the above-described control of Step S1, Step S2, and Step S3 is executed in order. Therefore, if the vehicle is not turning, the control returns without executing any particular control. Also, if the detected longitudinal acceleration Gx is stored for the first time, an affirmative determination is made in step S3, and the process proceeds to step S4 to obtain the actual stability factor khcurr, which is “kh [i]. = Khcurr "is stored. Thereafter, a negative determination is made in step S5, and the process proceeds to step S6. After the storage number i is incremented, the process returns.

  Thereafter, by executing the routine again, the timer is counted up in step S0, and because the stored number i is “i + 1 = 2”, a negative determination is made in step S3. Then, it is determined whether or not the absolute value of the difference between the current longitudinal acceleration Gx [i] and the previous longitudinal acceleration Gx [i-1] exceeds the reference value X. If the absolute value of the difference between the longitudinal accelerations Gx does not exceed the reference value X and a negative determination is made in step S7, the control example shown in FIG. 1 is configured to return. In the control example shown in FIG. 2, it is determined whether the elapsed time from the previous update, that is, the timer count value t is equal to or greater than the determination threshold value tx (step S13). The determination threshold value tx can be appropriately determined as a value that preferentially determines the update period of the definition formula by design. In this case, the determination threshold value tx may be a constant value, or may be a vehicle travel distance or age of use. It can also be set as a variable that changes accordingly.

If a negative determination is made in step S13, that is, if the elapsed time from the previous update has not reached the determination threshold value tx, the process returns without performing any particular control. On the contrary, when the elapsed time t from the previous update is equal to or greater than the determination threshold value tx and a positive determination is made in step S13, the longitudinal acceleration Gx is given by control (step S14). This control can be executed by changing the throttle opening of the engine 1 or causing a shift in the transmission 2. Further, the target value Gx ^* of the longitudinal acceleration Gx to be changed by the control is set so as to satisfy the following expression (1) for the longitudinal acceleration Gx [i = 2] stored for the second time.
| Gx * -Gx [i-1] |> X (1)

Therefore, the longitudinal acceleration Gx ^* generated by the control in step S14 is stored as the current longitudinal acceleration Gx [i], and the actual stability factor khcurr at that time is stored as kh [i] (step S4). Thereafter, the process proceeds to step S5 and step S6 as in the case of the first storage.

  Since there are three coefficients to be obtained, the routine shown in FIG. 2 is executed again, and at that time, the timer is counted up (step S0), and thereafter, the process proceeds to step S2 and step S3 and negative in step S3. Accordingly, the process proceeds to step S7. That is, it is determined whether or not the absolute value of the difference between the previous value and the current value of the longitudinal acceleration Gx exceeds the reference value X described above. If an affirmative determination is made in step S7, the process proceeds from step S8 to step S9, where the absolute value of the difference between the current value of the longitudinal acceleration Gx and the value stored for the first time becomes the reference value X. It is determined whether or not it exceeds. If the determination in step S9 is affirmative, the process proceeds from step S4 to step S5, step S10, step S11, and step S12 as in the control example shown in FIG. That is, each value of the coefficient is obtained, and the definition formula of the stability factor expanded based on the values is updated. Therefore, in step S12, in addition to the stored number i being reset to zero, the count value t of the timer is reset to zero.

On the other hand, if the absolute value of the difference between the current value of the longitudinal acceleration Gx and the previous value or the previous previous value is equal to or less than the reference value X, a negative determination is made in step S7 or step S9, the above-described step S13 is performed. And control of step S14 is performed. That is, it is determined whether or not the count value t of the timer is equal to or greater than the determination threshold value tx. If it is above, the longitudinal acceleration Gx is given by the control in the same manner as described above, and the target value at that time or the longitudinal acceleration Gx ^* actually generated is stored as the current value Gx [i]. In this case, the longitudinal acceleration Gx ^* given by the control is set to satisfy the following expression (2) by being stored in the third time.
| Gx ^* -Gx [i-1] |> X and | Gx ^* -Gx [i-2] |> X (2)
Then, as in the case where the absolute value of the difference between the current value of the longitudinal acceleration Gx and the previous value or the previous previous value exceeds the reference value X, the control after step S4 is executed and the extended stability factor The definition formula of is updated.

  In the case of the configuration shown in FIG. 2 above, the so-called forcible longitudinal acceleration Gx is forcibly changed without waiting for the longitudinal acceleration Gx to be greatly changed by the operation of the driver. A delay in updating the definition formula is avoided or suppressed. Therefore, control of steering, longitudinal acceleration, yaw rate, or the like with a stability factor having a value deviating from the actual value is avoided or suppressed, and drivability is improved.

  Here, the relationship between the above-described specific example and the present invention will be briefly described. The functional means for executing the control of the above-described steps S2, S7, and S9 corresponds to the acceleration / deceleration detecting means in the present invention. The functional means for executing the control in step S4 corresponds to the stability factor calculating means in the present invention, the functional means for executing the control in step S10 corresponds to the coefficient calculating means in the present invention, and further in step S11. The functional means for executing the control corresponds to the updating means in the present invention. And the functional means which performs control of Step S13 and Step S14 is equivalent to the longitudinal acceleration generating means in this invention.

  DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Transmission, 3 ... Differential (final reduction gear), 4 ... Wheel speed sensor, 5 ... Yaw rate sensor, 6 ... Electronic controller for vehicles (vehicle ECU), 7 ... Electronic control for engine / transmission Device (Engine / TM ECU), Rl ... Left rear wheel, Rr ... Right rear wheel, Fl ... Left front wheel, Fr ... Right front wheel.

Claims (2)

In a vehicle control device for obtaining a stability factor extended to a turn with acceleration / deceleration for the vehicle based on data obtained when the vehicle actually turns,
Rutotomoni determined at least three of the longitudinal acceleration of the different values at which the vehicle is actually cornering, the three absolute values the three longitudinal to be greater than the predetermined reference value of the difference of the longitudinal acceleration mutual a pressure deceleration detecting means for determining an acceleration,
Stability factor calculation means for determining the actual stability factor at each driving for which the longitudinal acceleration was obtained,
The acceleration / deceleration detecting means is a relational expression in which the stability factor during turning with acceleration / deceleration is equal to the sum of a term obtained by multiplying the square of the longitudinal acceleration by a coefficient and a term obtained by multiplying the longitudinal acceleration by another coefficient and a constant term. Substituting the longitudinal acceleration obtained in step 3 and the actual stability factor obtained by the stability factor calculation means to establish a ternary simultaneous linear equation, Coefficient calculation means for obtaining respective values for the term constants;
Update means for updating the stability factor definition formula extended to the turn with acceleration / deceleration by substituting the constants of the coefficient and other coefficients obtained by the coefficient calculation means and constants into the relational expression ,
When the elapsed time until the longitudinal acceleration having a difference larger than the reference value with respect to the longitudinal acceleration that has already been obtained among the three longitudinal accelerations has passed a predetermined time, the longitudinal Longitudinal acceleration generating means for causing the vehicle to generate longitudinal acceleration in which the absolute value of the difference from acceleration is greater than the reference value;
The vehicle control apparatus characterized by the above-mentioned. Before SL elapsed time, control apparatus for a vehicle according to claim 1, characterized in that it comprises a time defining equation of the stability factor starts counting from the time it is updated by the update unit.

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