JP4853365B2 - Vehicle rollover risk determination device - Google Patents

Description

  The present invention relates to a vehicle rollover risk determination device, and more particularly to a device for determining a vehicle rollover risk based on a roll angle and a roll angular velocity of a running vehicle.

  Conventional examples [1] and [2] of the above-described vehicle rollover risk determination device will be described below with reference to FIGS.

Conventional example [1]: Fig. 6 to Fig. 11
The vehicle rollover risk determination device 1 shown in FIG. 6 includes a vehicle height sensor 10 that detects vehicle height displacement signals HL and HR on both the left and right sides of the vehicle, a vehicle steering angle θ, and the steering angle θ. Steering angle / steering angular velocity detection unit 20 that calculates steering angular velocity ω by differentiation, roll angle / roll angular velocity calculation unit 30 that calculates vehicle roll angle X and roll angular velocity Y from vehicle height displacement signals HL and HR, and roll A rollover that determines the risk of rollover of a vehicle using a two-dimensional map that shows the relationship between the roll angle and roll angular velocity of the vehicle based on the angle X and the roll angular velocity Y, and outputs a rollover determination flag FLG that indicates whether there is a risk of rollover. Based on the determination unit 40, the vehicle height displacement signals HL and HR, the steering angle θ and the steering angular speed ω, the influence of the road surface undulation state and the running state of the vehicle are determined, and the rollover risk in the rollover determination unit 40 is determined according to the determination result Set the weighting coefficient q used to determine It is composed of a road surface condition-running state determination unit 50.

  The rollover determination flag FLG is input to a brake controller, an alarm device, or the like (not shown), and is used for brake control and alarm control for preventing the vehicle from rolling over.

  In operation, as shown in FIG. 7, first, the vehicle roll angle X1 and roll angular velocity Y1 are calculated by the mutual operation of the vehicle height sensor 10 and the roll angle / roll angular velocity calculation unit 30, and given to the rollover judging unit 40. (Step S20).

That is, as shown in FIG. 8, the vehicle height sensor 10 detects vehicle height displacement signals HL and HR on the left and right sides of the vehicle (step S30), and the roll angle / roll angular velocity calculation unit 30 detects these vehicle height displacements. Low-pass filter processing is performed on the signals HL and HR to extract low frequency components HL _L and HR _L (that is, signal components from which noise components due to road surface undulations have been removed) (step S31).

  Then, the roll angle / roll angular velocity calculation unit 30 calculates the roll angle X1 according to the following equation (1) (step S32).

  In the above equation (1), SL represents a detection unit for detecting the vehicle height displacement signal HL on the left side of the vehicle and a detection unit for detecting the vehicle height displacement signal HR on the right side (both not shown. Vehicle height sensor 10 This is the distance between each other.

  Further, the roll angle / roll angular velocity calculation unit 30 calculates the roll angular velocity Y1 according to the following equation (2) (step S33).

  Here, X0 in the above equation (2) is a roll angle calculated before time Δt. After executing step S33, the roll angle / roll angular velocity calculation unit 30 overwrites the memory MEM with the roll angle X1 calculated in step S32 as the roll angle X0. Thereby, the roll angle / roll angular velocity calculation unit 30 can calculate the roll angular velocity Y1 every time the roll angle X1 is calculated.

  The rollover judging unit 40 that has received the roll angle X1 and the roll angular velocity Y1, for example, the point S specified by the roll angle X1 and the roll angular velocity Y1 from the boundary lines T1 and T2 set on the two-dimensional map as shown in FIG. The respective distances L1 and L2 to (X1, Y1) are obtained according to the following equations (3) and (4) (step S21).

  However, as shown in FIG. 9, A1 and B1 in the above equation (3) are the X-axis intercept and Y-axis intercept of the boundary line T1, and A2 and B2 in the above equation (4) are the boundary line T2. X-axis intercept and Y-axis intercept.

  Further, in this example, the left rollover risk area R2L side with respect to the boundary line T1 and the right rollover risk area R2R side with respect to the boundary line T2 are set as positive, and in both cases, the stable area R1 side is set as negative. Therefore, the distance L1 has a positive polarity, and the distance L2 has a negative polarity. That is, since the polarity of the distance L1 is positive, there is a risk that the vehicle rolls over to the left.

  Then, the rollover judging unit 40 calculates the moving speed V1 with respect to the boundary line T1 of the point S from the distance L1 with a positive polarity according to the following equation (5), and also from the distance L2 to the boundary line of the point S The moving speed V2 with respect to T2 is calculated according to the following equation (6) (step S22).

  Here, the polarities of the moving speeds V1 and V2 are the same as the distances L1 and L2 (that is, positive and negative polarities, respectively).

  Further, the magnitudes of the moving speeds V1 and V2 are, for example, when the point S draws a locus P indicated by a solid line in FIG. 9 from the origin and moves away from the stable region R1 and enters the left rollover risk region R2L (i.e., roll (When the change in angular velocity is small and the vehicle slowly enters), or when entering the left side rollover risk area R2L with the locus Q shown by the alternate long and short dash line in the same figure (that is, when the roll angular velocity increases rapidly) is there.

  That is, the movement speeds V1 and V2 draw a trajectory P or Q, and the point S that entered the left rollover risk area R2L moves away from the stable area R1 at the next moment, and rapidly enters the left rollover danger area R2L. This indicates the possibility (that is, the possibility that the risk of rollover of the vehicle rapidly increases).

  For this reason, the rollover judging unit 40 calculates a weighted value by multiplying the polarity and magnitude l1 of the distance L1 by a constant p and a weighted value by multiplying the polarity and magnitude v1 of the moving speed V1 by a coefficient q. The sum is calculated as the risk D1 of entering point S into the left rollover risk area R2L (see equation (7)). Similarly, the rollover judging unit 40 weights the distance L2 and the moving speed V2, takes the sum, and calculates the approach risk D2 of the point S to the right rollover risk area R2R (see Expression (8)) ( Step S23).

  In addition, since the approach risk degrees D1 and D2 are calculated as having only the polarity and magnitude of the distance and the moving speed by the above weighting, the unit of the distance and the moving speed is not interposed.

  Here, since the terms of the moving speeds V1 and V2 in the approach risk D1 and D2 correspond to the prediction terms of the roll state of the vehicle, when the vehicle is traveling on a large road surface such as unevenness, the distance L1 and It is easier to be affected by noise components faster than the term L2, and the effect appears greatly. Therefore, depending on the undulation state of the road surface on which the vehicle travels, there is a possibility that it may be erroneously determined that there is a risk of rollover in spite of stable travel.

  For this reason, the moving speed weighting coefficient q is determined by the vehicle height sensor 10, the steering angle / steering angular velocity detection unit 20, and the road surface state / running state determination unit 50 due to the interaction between the road surface undulation state and the vehicle running. It is set dynamically according to the state.

  That is, as shown in FIG. 10, first, the vehicle height sensor 10 detects vehicle height displacement signals HL and HR on both the left and right sides of the vehicle, and provides them to the road surface state / traveling state determination unit 50 (step S40).

The road surface state / running state determination unit 50 performs high-pass filter processing and low-pass filter processing in parallel on these vehicle height displacement signals HL and HR (steps S41_H and S41_L). That is, in the above step S41_H, only the high frequency components HL _H and HR _H (that is, noise components) in the vehicle height displacement signals HL and HR are passed, respectively, and in the above step S41_L, the vehicle height displacement signals HL and HR are passed. Only the low frequency components HL _L and HR _{L in the} middle (that is, the signal component from which the noise component has been removed) are passed.

Then, road surface condition, the traveling state determining section 50, respectively, to calculate the roll angle X _H and X _L in accordance with the following equation (9) and (10) (step S42_H and S42_L).

Thereafter, the road surface state and running state determining section 50, respectively, calculates an integrated value SUM _L of the integrated value SUM _H and the roll angle X _L of the roll angle X _H according to the following equation (11) and (12) ( Steps S43_H and S43_L).

However, t in the above equations (11) and (12) is the time (current time) when the roll angle integral values SUM _H and SUM _L are calculated, and ts is a certain time before the current time t. It's time.

Then, the road surface state / traveling state determination unit 50 compares the roll angle integral values SUM _H and SUM _L to determine whether the influence of the undulation state of the road surface on which the vehicle travels is large (step S44). . That is, the road surface state / running state determination unit 50 determines that the influence of the road surface undulation state is large when the roll angle integral value SUM _H > SUM _L is satisfied, and the roll angle integral value SUM _H ≦ SUM _L is satisfied. It is determined that the influence of the road surface undulation is small.

  When it is determined in step S44 that the influence of the undulation state of the road surface is small, the road surface state / traveling state determination unit 50 sets the moving speed weighting coefficient q to an effective value PV (a vehicle roll characteristic or the like is set in advance). Value) and give to the rollover judging unit 40 (step S45).

  As a result, the approaching risks D1 and D2 shown in the above equations (7) and (8) are the terms of the moving speed V1 (polarity and magnitude v1) and the terms of the moving speed V2 (polarity and magnitude v2). ) Can be included.

  On the other hand, when it is determined in step S44 that the influence of the undulation state of the road surface is large, the road surface state / running state determination unit 50 determines that the steering angle θ and the steering angular velocity ω of the vehicle from the steering angle / steering angular velocity detection unit 20 Wait for input (step S46).

  When the steering angle θ and the steering angular velocity ω are input, the road surface state / traveling state determination unit 50 determines the traveling state of the vehicle based on the steering angle θ and the steering angular velocity ω using, for example, a two-dimensional map shown in FIG. (Step S47).

  Here, this two-dimensional map is divided into a stable region R1 and a rollover risk region R2 by a boundary line T expressed by the following equation (13).

  Further, the stable region R1 indicates a stable traveling state in which the vehicle goes straight and is close to steady steering, and the rollover risk region R2 indicates a traveling state in which the vehicle is more turned and close to sudden steering (that is, there is a risk that the vehicle rolls over). A certain state).

  Assuming that the point on the two-dimensional map specified by the steering angle θ and the steering angular velocity ω is the point W1 on the stable region R1 side, the road surface state / running state determination unit 50 causes the vehicle to travel stably. The moving speed weighting coefficient q is set to “0” (that is, invalid) (step S48).

  As a result, the term of the moving speed V in the approach risk D becomes “0”, and therefore the approach risk D can include only the term of the distance L.

  On the other hand, the point on the two-dimensional map specified by the steering angle θ and the steering angular velocity ω has transitioned from the point W1 to the point W2 on the rollover risk area R2 side when the vehicle has made a sharp turn or the like. At this time, the road surface state / running state determination unit 50 determines that there is a risk that the vehicle rolls over, and executes step S45 described above to set the moving speed weighting coefficient q to the effective value PV.

  As a result, even when the influence of the undulation state of the road surface is large, when there is urgency in the determination of the rollover risk, the approach risk D includes both the term of the distance L and the term of the moving speed V. be able to.

  Then, as shown in FIG. 7, the rollover judging unit 40 selects the maximum approach risk Dmax including polarity from the approach risk D1 and D2 calculated in step S23, according to the equation (14) ( Step S24).

  In this example, both the distance L1 and its moving speed V1 have a positive polarity, and both the distance L2 and its moving speed V2 have a negative polarity. D2 shows negative polarity. Accordingly, the approach risk D1 is selected as the maximum approach risk Dmax. The rollover judging unit 40 sets the maximum approach risk Dmax as the rollover risk H (step S25).

  When the rollover risk H indicates a negative polarity, the rollover determination unit 40 determines that there is no risk of rollover (within the safety region R1) (step S26), and sets the rollover determination flag FLG to “0” ( Step S27).

  On the other hand, in the above step S26, when the rollover risk H indicates a positive polarity, the rollover determination unit 40 determines that there is a risk of rollover (within the rollover risk area R2 (R2L or R2R)), and the rollover determination flag FLG is set to “1” (step S28).

  In this way, it is possible to quickly determine the rollover risk that continuously changes according to the roll state of the vehicle, and to output the rollover determination flag FLG indicating the presence or absence of the rollover risk (for example, the present application) (See human patent application 2006-337262.)

Conventional example [2]: Fig. 9
The boundary line (reference threshold) on the two-dimensional map showing the relationship between the roll angle and the roll angular velocity as shown in FIG. 9 changes based on the roll angle and the lateral acceleration calculated from the vehicle running speed and steering angle. A vehicle rollover risk determination device (see, for example, Patent Document 1).
JP 2005-001522 A

  In the above conventional example [1], when a vehicle is turning relatively large on a large road surface with unevenness or the like at a low traveling speed, there is actually no risk of rollover even though there is no risk of rollover. There was a situation where it was misjudged if there was sex. This may be due to insufficient removal of noise components from the vehicle height displacement signal in the roll angle and roll angular velocity calculation processing (for example, the cut-off frequency of the low-pass filter processing is high) or the boundary on the two-dimensional map. The line may not be appropriate. In this case, it is possible to take measures to change the cutoff frequency and the boundary line on the two-dimensional map, but this measure changes the roll characteristics of the vehicle itself (i.e., the determination result other than the above driving conditions). It is not a good idea.

  In the above conventional example [2], the boundary line on the two-dimensional map is changed based on the roll angle and the lateral acceleration. For example, when the vehicle transits from a sudden turning state to a straight traveling state. Since no steering angle is detected, the lateral acceleration is not calculated. In this case, since the boundary line on the two-dimensional map is not set appropriately, there is a problem that it is erroneously determined that there is no risk of rollover even though the vehicle has a risk of rollover.

  Accordingly, an object of the present invention is to provide an apparatus capable of preventing erroneous determination when there is no risk of rollover when determining the risk of rollover of a vehicle.

 [1] In order to achieve the above object, a rollover risk determination device for a vehicle according to the present invention includes a first rollover determination unit that determines a rollover risk of the vehicle based on a roll angle and a roll angular velocity of the vehicle, From the time when the lateral acceleration generated in the vehicle exceeds a predetermined threshold to the time when the lateral acceleration changes below the threshold and the first rollover determination unit determines that the rollover risk is low. The rollover risk of the vehicle is determined except when the second rollover determination unit that determines that the rollover risk of the vehicle is high and the first and second rollover determination units both determine that the rollover risk is high. And a final determination unit that finally determines that the value is low.

  That is, the first rollover determination unit determines the rollover risk based on the roll angle and the roll angular velocity of the vehicle in the same manner as the rollover determination unit 40 of the conventional example [1] shown in FIG.

  In addition, the second rollover judging unit judges that the vehicle is in a sharp turning state from when the lateral acceleration generated in the vehicle exceeds a predetermined threshold, and rolls over due to the lateral acceleration. It is determined that the degree of danger is high, and then the rollover risk based on the roll angle and the roll angular velocity is determined to be low by the first rollover judgment unit even after the lateral acceleration decreases and changes below the threshold. For example, it is determined that the vehicle has transitioned from a rapid turning state to a straight traveling state (that is, the lateral acceleration is not detected), and the risk of rollover due to the lateral acceleration is determined to be high. .

  Thereafter, the second rollover determination unit determines that the roll angle and roll angular velocity of the vehicle are not in a state of high risk of rollover, and determines that the rollover risk due to the lateral acceleration is low.

  The final determination unit determines that the vehicle rollover risk is high when both the first and second rollover determination units determine that the rollover risk is high. Since it is determined that the risk of rollover is low, it is possible to prevent erroneous determination when there is no risk of rollover.

 [2] Also, in [1] above, the first rollover judging section distinguishes between a rollover risk area and a stable area set on a two-dimensional map indicating the relationship between the roll angle and roll angular velocity of the vehicle. The distance from the line to the point on the two-dimensional map specified by the roll angle and the roll angular velocity is calculated, and the moving speed of the point with respect to the boundary line is calculated from the distance, and the distance and the moving speed are calculated. When it is determined that the point moves away from the stable region and enters the rollover risk region, it may be determined that the risk of rollover of the vehicle is high.

 [3] Also, in the above [2], when it is determined that the roll angle and roll angular velocity do not include the influence of the undulation state of the road surface on which the vehicle travels based on the vehicle height displacement of the vehicle, or the undulation The movement used for the determination of the first rollover determination unit when it is determined that the vehicle is not traveling stably based on the steering angle and the steering angular velocity of the vehicle even when the influence of the state is included You may further provide the road surface state and driving state determination part which makes speed effective.

  According to the present invention, it is possible to prevent erroneous determination when there is no risk of rollover when determining the risk of rollover of the vehicle. It can be determined accurately. Thereby, vehicle rollover prevention control (brake control, alarm control, etc.) can be performed correctly.

  An embodiment of a vehicle rollover risk degree judging device according to the present invention will be described below with reference to FIGS.

Example: FIGS. 1-5
Configuration example: Figure 1
In addition to the conventional configuration shown in FIG. 6, a vehicle rollover risk determination device 1 according to the embodiment of the present invention shown in FIG. 1 includes a vehicle speed sensor 60 that detects a vehicle traveling speed (hereinafter, vehicle speed) SP. A lateral acceleration calculation unit 70 for calculating a lateral acceleration Gye generated in the vehicle from the vehicle speed SP and the steering angle θ output from the steering angle / steering angular velocity detection unit 20, and an output from the lateral acceleration Gye and the rollover determination unit 40 The rollover judgment flag 80 that determines the risk of rollover of the vehicle based on the rollover judgment flag FLG1 and outputs a rollover judgment flag FLG2 that indicates whether there is a risk of rollover, and the vehicle rollover based on the rollover judgment flags FLG1 and FLG2 And a final determination unit 90 that finally determines the degree of risk and outputs a final rollover determination flag FLG_F that indicates whether there is a risk of rollover.

Further, the rollover judging unit 80 uses a predetermined threshold G _Th1 when judging the risk of rollover of the vehicle based on the lateral acceleration Gye. This threshold G _Th1 is set in advance according to the rollover limit characteristic of the vehicle.

  In the rollover risk determination device 1, a brake controller, an alarm device (both not shown) or the like may be connected after the final determination unit 90 to give the final rollover determination flag FLG_F.

Example of operation: Fig. 1 to Fig. 5
Next, operations of the vehicle speed sensor 60, the lateral acceleration calculation unit 70, the rollover determination unit 80, and the final determination unit 90 included in the rollover risk determination device 1 illustrated in FIG. 1 will be described with reference to FIGS. explain. 2 shows an operation flow of the rollover judging unit 80, and FIG. 4 shows an operation flow of the final judging unit 90. Further, the operations of the vehicle height sensor 10, the steering angle / steering angular velocity detection unit 20, the roll angle / roll angular velocity calculation unit 30, the rollover determination unit 40, and the road surface state / running state determination unit 50 will be described with reference to FIGS. Since it is the same as the conventional example described, the description thereof is omitted.

  As shown in FIG. 1, first, the vehicle speed sensor 60 detects the vehicle speed SP and provides it to the lateral acceleration calculation unit 70. At the same time, the steering angle / steering angular velocity detector 20 gives the detected steering angle θ to the lateral acceleration calculator 70.

  The lateral acceleration calculation unit 70 calculates the lateral acceleration Gye from the vehicle speed SP and the steering angle θ according to the following equation (15), and provides the lateral roll determination unit 80 with the lateral acceleration Gye.

  However, WB and GR in the above equation (15) are the vehicle wheel base length and the steering gear ratio (both are constants), respectively. That is, the above equation (15) indicates that the lateral acceleration Gye follows the magnitude (absolute value) of the steering angle θ (0 ° <θ <90 °).

  As shown in FIG. 2, the rollover judging unit 80 that has received the roll acceleration Gye judges the rollover risk of the vehicle, and outputs a rollover judgment flag FLG2 indicating whether or not there is a risk of rollover.

That is, as shown in FIG. 3 (1), when taking a case where the vehicle transitions from a sudden turn traveling state to a straight traveling state, the rollover judging unit 80 determines that the lateral acceleration Gye (t) at a time before time t0. Is less than or equal to the threshold G _Th1 (step S1), and the internal running state storage variable s is referred to (step S4).

  Here, the running state storage variable s is a variable for storing that the vehicle has transitioned from the sudden turning state to the straight running state or the gentle turning state, and from the sudden turning state to the straight running state. Alternatively, “1” is set when transitioning to the gentle turning state, and “0” is set otherwise (including the initial state).

Now, if the rollover judging unit 80 is in the initial state, the running state storage variable s = “0” is established, and therefore the rollover judging unit 80 has the lateral acceleration Gye (t−Δt) before the sampling interval Δt. Whether or not the threshold G _Th1 has been exceeded (i.e., whether the lateral acceleration Gye (t) has changed from a state in which the threshold G _Th1 has been exceeded to a state in which the threshold G _{Th1 is} below, or a state in which the threshold G _{Th1 is} below the threshold G _Th1 before Δt (Step S5). Since the lateral acceleration Gye (t−Δt) is also equal to or less than the threshold value G _Th1 before the time t0, the rollover determination unit 80 determines that the rollover risk is low based on the vehicle lateral acceleration Gye and determines the rollover determination flag. FLG2 is set to “0 (no risk of rollover)” (step S9).

On the other hand, at time t0, as the steering angle θ increases rapidly, the lateral acceleration Gye also increases following the above equation (15), and when the lateral acceleration Gye (t0) exceeds the threshold value G _Th1 (FIG. (Refer to (2).), The rollover judging unit 80 determines that the vehicle is in a sudden turning traveling state in step S1, and maintains the running state storage variable s = “0 (rapid turning traveling)”. Together with (Step S2), it is determined that the risk of rollover based on the lateral acceleration Gye of the vehicle is high, and the rollover determination flag FLG2 is set to “1 (There is a risk of rollover)” (Step S3, FIG. 3 (4)). .

Further, since the roll angle X increases as the steering angle θ increases, at the time t1 when the roll angle X exceeds the threshold value G _Th2 , the rollover judging unit 40 shown in FIG. Similarly, the rollover determination flag FLG1 is set to “1 (there is a risk of rollover)” (FIG. 3 (3)). At this time, since the lateral acceleration Gye (t1) still exceeds the threshold value G _Th1 , the rollover determination unit 80 maintains the rollover determination flag FLG2 = “1”.

Thereafter, until time t2, the steering angle θ is large and the lateral acceleration Gye exceeds the threshold value G _Th1 , but at time t3, the vehicle transitions to a gentle turning state and the steering angle θ is small. becomes, the rollover determination unit 80, in step S1 described above is determined that the lateral acceleration Gye (t3) is the threshold value G _Th1 or less, in the step S4 described above, the running state storage for variable s is set to "0" It is determined whether or not.

Now, since the traveling state storage for variable s is set to "0", the rollover determination unit 80 in step S5 above, or the sampling interval Δt before the lateral acceleration Gye (t2) exceeds the threshold value G _Th1 Determine whether or not. Since the lateral acceleration Gye (t2) exceeds the threshold G _Th1 , the rollover determination unit 80 changes from a state where the lateral acceleration Gye exceeds the threshold G _Th1 to a state equal to or less than the threshold G _Th1 (that is, at time t3). The vehicle has transitioned from a sudden turning state to a slow turning state or a straight running state) and is set to `` 1 (slow turning or straight running) '' in the running state storage variable s (step S6), It is determined whether or not the rollover determination flag FLG1 is “1” (that is, whether or not the rollover risk is high based on the roll angle X of the vehicle and the roll angular velocity calculated therefrom) (step S7).

  Now, since the rollover determination flag FLG1 = “1”, the rollover determination unit 80 executes the above step S3 again and outputs the rollover determination flag FLG2 = “1”.

Thereafter, until the time t4, the roll angle X is larger than the threshold value G _Th2 , the rollover determination flag FLG1 = “1”, and the running state storage variable s remains set to “1”. The determination unit 80 repeatedly executes the above steps S4 to S7 and S3 and outputs a rollover determination flag FLG2 = “1”.

On the other hand, when the roll angle X becomes equal to or smaller than the threshold value G _{Th2 at} time t5, and the rollover determination unit 40 changes the rollover determination flag FLG1 to “0”, the rollover determination unit 80 performs the above steps S1 and S4 to S7. , The running state storage variable s is initialized to “0” (step S8), and in step S9, it is determined that the risk of rollover based on the lateral acceleration Gye of the vehicle is low, and the rollover determination flag is set. Set FLG2 to “0”.

Thereafter, when the lateral acceleration Gye (t6) is received at time t6, the lateral acceleration Gye (t6) and Gye (t5) are both equal to or less than the threshold value G _Th1 and the running state storage variable s is “0”. The rollover determination unit 80 outputs the rollover determination flag FLG2 = “0” via the above steps S1, S4, S5, and S9.

  Upon receiving the rollover determination flag FLG2 output as described above and the rollover determination flag FLG1 output from the rollover determination unit 40, the final determination unit 90 finally determines the rollover risk of the vehicle as shown in FIG. The final rollover determination flag FLG_F indicating whether there is a risk of rollover is output.

  That is, when both the rollover determination flags FLG1 and FLG2 indicate “1 (there is a risk of rollover due to the roll angle X, the roll angular velocity, and the lateral acceleration Gye”) (step S10), the final determination unit 90 performs the rollover of the vehicle. It is determined that the degree of risk is high, and the final rollover determination flag FLG_F is set to “1” (step S11).

  On the other hand, in the above step S10, when one or both of the rollover determination flags FLG1 and FLG2 indicate “0 (no risk of rollover due to roll angle X and roll angular velocity, or lateral acceleration Gye)”, the final The determination unit 90 determines that the risk of rollover of the vehicle is low, and sets the final rollover determination flag FLG_F to “0” (step S12).

  Therefore, when the rollover determination flags FLG1 and FLG2 exhibit the characteristics shown in FIGS. 3 (3) and (4), respectively, the final rollover determination flag FLG_F is “ It is set to “1”, and is set to “0” at other times t0, t5, and t6.

In addition, as shown in FIG. 6 (6), the vehicle exhibits a characteristic in which the lateral acceleration Gye is less than the threshold value G _Th1, but is in a relatively large turning state, and the noise component due to the road surface undulation effect on the roll angle X. In the case where (indicated by diagonal lines) is included (that is, when there is actually no risk of rollover of the vehicle), the lateral acceleration Gye is less than or equal to the threshold G _Th1 at times t7 to t11 ( 7), the rollover judging unit 80 makes a positive judgment that the rollover risk is low based on the lateral acceleration Gye of the vehicle, and outputs a rollover judgment flag FLG2 = “0” as shown in FIG.

On the other hand, the rollover determination unit 40 makes a positive determination that the rollover risk is low based on the roll angle X and the roll angular velocity of the vehicle because the roll angle X is equal to or less than the threshold G _Th2 at time t7 and time t10 to t11. As shown in FIG. 8 (8), rollover determination flag FLG1 = "0" is output, but from time t8 to t9, the roll angle X exceeds the threshold value G _Th2 , so it is based on the roll angle X and the roll angular velocity of the vehicle. If the risk of rollover is high, the rollover determination flag FLG1 = "1" is output.

  However, since the rollover determination flags FLG1 and FLG2 do not both become “1” from time t7 to t11, the final determination unit 90 determines that the risk of rollover of the vehicle is low, as shown in FIG. The final rollover judgment flag FLG_F is set to “0”.

Further, as shown in FIG. 5 (1), the vehicle exhibits a characteristic in which the roll angle X is equal to or less than the threshold value G _Th2, but is making a large turn while the vehicle speed SP is low. Example when lateral acceleration Gye exceeds threshold G _Th1 between t13 and t14 (for example, when there is no risk of rollover of the vehicle but the steering angle θ changes greatly, such as when turning over when entering the garage) In this case, the rollover determination unit 80 erroneously determines that the risk of rollover based on the lateral acceleration Gye of the vehicle is high, and outputs a rollover determination flag FLG2 = “1” as shown in FIG.

On the other hand, the rollover determination unit 40 positively determines that the rollover risk based on the roll angle X and the roll angular velocity of the vehicle is low since the roll angle X is equal to or less than the threshold value G _{Th2 at} times t12 to t15. ), The rollover judgment flag FLG1 = "0" is output.

  Accordingly, since the rollover determination flags FLG1 and FLG2 do not both become “1” from time t12 to t15, the final determination unit 90 determines that the risk of rollover of the vehicle is low, as shown in FIG. The final rollover judgment flag FLG_F is set to “0”.

  In this way, the final determination unit 90 can accurately determine the degree of rollover risk of the vehicle based on both the rollover determination flags FLG1 and FLG2.

  Note that the present invention is not limited to the above-described embodiments, and it is obvious that various modifications can be made by those skilled in the art based on the description of the scope of claims.

It is the block diagram which showed the example of a structure of the Example of the vehicle rollover risk degree determination apparatus which concerns on this invention. It is the flowchart figure which showed the operation example of the 2nd rollover determination part used for the Example of the rollover risk degree determination apparatus of the vehicle which concerns on this invention. It is the time chart which showed an example of the running state transition of the vehicle used for the Example of the vehicle rollover risk determination apparatus which concerns on this invention. It is the flowchart figure which showed the operation example of the final determination part used for the Example of the vehicle rollover risk degree determination apparatus which concerns on this invention. It is the time chart figure which showed the other example of the running state transition of the vehicle used for the Example of the rollover risk degree determination apparatus of the vehicle which concerns on this invention. FIG. 10 is a block diagram showing a configuration example of a conventional example [1] of a vehicle rollover risk degree determination device. FIG. 10 is a flowchart showing an example of the overall operation of the conventional example [1] of the vehicle rollover risk determination device. FIG. 10 is a flowchart showing an example of a roll angle and roll angular velocity calculation process of a conventional example [1] of the vehicle rollover risk determination device. FIG. 10 is a graph showing an example of a two-dimensional map used in the conventional example [1] of the vehicle rollover risk determination device. FIG. 10 is a flowchart showing an operation example of a road surface state / running state determination unit used in the conventional example [1] of the vehicle rollover risk degree determination device. FIG. 10 is a graph showing a running state determination example (two-dimensional map example) of a road surface state / running state determination unit used in the conventional example [1] of the vehicle rollover risk determination device.

Explanation of symbols

1 Rolling risk assessment device
10 Vehicle height sensor
20 Steering angle / steering angular velocity detector
30 Roll angle / roll angular velocity calculator
40, 80 Rollover judgment part
50 Road surface / running state judgment unit
60 Vehicle speed detector
70 Lateral acceleration calculator
90 Final judgment part
X, X1, X _H , X _L roll angle
Y, Y1 Roll angular velocity
L, L1, L2 distance
V, V1, V2 Travel speed
H Rollover risk
HL, HR Vehicle height displacement signal
HL _H high frequency components
HL _L low frequency component
SUM _H , SUM _L Roll angle integral value
p Distance weighting constant
q Moving speed weighting factor
PV effective value θ Steering angle ω Steering angular velocity
SP vehicle speed
Gye lateral acceleration
G _Th1 , G _Th2 threshold
FLG, FLG1, FLG2 Rollover judgment flag
FLG_F Final rollover judgment flag
s Variable for running state memory
A1, A2 X-axis intercept
B1, B2 Y-axis intercept
D1, D2 Risk of entering
Dmax Maximum approach risk
R1 stability region
R2, R2L, R2R Rolling over danger area
T, T1, T2 boundary lines In the figure, the same reference numerals indicate the same or corresponding parts.

Claims (3)

A first rollover judging unit for judging the rollover risk of the vehicle based on the roll angle and roll angular velocity of the vehicle;
From the time when the lateral acceleration generated in the vehicle exceeds a predetermined threshold to the time when the lateral acceleration changes below the threshold and the first rollover determination unit determines that the rollover risk is low. A second rollover judging unit for judging that the risk of rollover of the vehicle is high;
A final determination unit that finally determines that the rollover risk of the vehicle is low, except when both the first and second rollover determination units determine that the risk of rollover is high;
A vehicle rollover risk determination device characterized by comprising: In claim 1,
The first rollover judging unit is identified by the roll angle and the roll angular velocity from a boundary line that distinguishes the rollover danger region and the stable region set on the two-dimensional map indicating the relationship between the roll angle and the roll angular velocity of the vehicle. Calculating a distance to the point on the two-dimensional map, and calculating a moving speed of the point with respect to the boundary line from the distance, and moving the point away from the stable region from the distance and the moving speed. A vehicle rollover risk determination device, characterized in that, when it is determined that the vehicle is about to enter a rollover risk region, the vehicle rollover risk is determined to be high. In claim 2,
Even when it is determined that the roll angle and roll angular velocity do not include the influence of the undulation state of the road surface on which the vehicle travels based on the vehicle height displacement of the vehicle, or even when the influence of the undulation state is included Road surface state / running state determination that enables the moving speed used for the determination of the first rollover determination unit when it is determined that the vehicle is not traveling stably based on the steering angle and steering angular speed of the vehicle A vehicle rollover risk determination device characterized by further comprising a section.

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