JP2010116105A - Bank angle restriction device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the value of an estimated band angle from being made unstable by restricting the estimated bank angle when the amount of behavior of a vehicle largely changes, or when a curve is a reversing bank. <P>SOLUTION: A bank angle restriction device 10A is provided with: a low pass filter part 12 equipped with a low pass filter 16; and a vehicle behavior determination part 14 for determining whether or not the amount of behavior of a vehicle is more than a prescribed threshold. When it is determined that the amount of behavior is more than the threshold by the vehicle behavior determination part 14, the low pass filter part 12 outputs the estimated bank angle of a road surface estimated by the bank angle estimation device loaded on the vehicle through a low pass filter 16. On the other hand, when it is determined that the amount of behavior is equal to or less than the threshold by the vehicle behavior determination part 14, the low pass filter part 12 directly outputs the estimated bank angle. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a bank angle limiting device for limiting an estimated bank angle of a road surface estimated by a bank angle estimating device mounted on a vehicle.

  Conventionally, the bank angle (estimated bank angle) of the road surface on which the vehicle travels is estimated based on the behavior amount of the vehicle such as the vehicle speed, the yaw rate, and the lateral acceleration of the vehicle, and the vehicle angle of the vehicle is estimated using the estimated bank angle. Controlling behavior is widely performed (see Patent Documents 1 and 2).

JP 2006-138800 A JP 2006-236238 A

  As described above, since the estimated bank angle is estimated based on the amount of behavior of the vehicle, the actual bank angle of the road surface on which the vehicle is traveling hardly changes with the movement of the vehicle. First, when the amount of behavior changes greatly according to changes in the behavior of the vehicle while traveling or the road surface condition, the estimated bank angle also changes greatly, and the value of the estimated bank angle becomes unstable. There is a risk. Further, when estimating a bank angle in a so-called reverse bank where the inside of the curve is high and the outside is low, the estimated bank angle may be erroneously estimated and the value of the estimated bank angle may become unstable.

  The present invention has been made in consideration of such problems, and restricts the estimated bank angle when the amount of vehicle behavior changes greatly, or when the curve is an inverse bank, and the estimated bank An object of the present invention is to provide a bank angle limiting device that prevents the angle value from becoming unstable.

  The bank angle limiting device according to the present invention includes a low-pass filter unit including a low-pass filter, and a vehicle behavior determination unit that determines whether or not a vehicle behavior amount is greater than a predetermined threshold, and the low-pass filter unit includes: When the vehicle behavior determination unit determines that the behavior amount is larger than the threshold value, the estimated bank angle of the road surface estimated by the bank angle estimation device mounted on the vehicle is output via the low-pass filter, On the other hand, when the vehicle behavior determination unit determines that the behavior amount is equal to or less than the threshold value, the estimated bank angle is directly output.

  According to this configuration, when the behavior amount of the vehicle is larger than the threshold value, the estimated bank angle is output through the low-pass filter. Therefore, even if the behavior amount changes greatly, The estimated bank angle can be limited so that the value of the estimated bank angle does not become unstable.

  On the other hand, when the behavior amount of the vehicle is equal to or less than the threshold value, the estimated bank angle is directly output without passing through the low-pass filter, so that the phase delay of the estimated bank angle can be suppressed.

  In this case, if the differential value of the yaw rate of the vehicle is used as the behavior amount, the estimated bank angle can be reliably limited when the vehicle makes a large turn.

  Further, the bank angle limiting device according to the present invention includes a limit value setting unit that sets a limit value of a rate of change of an estimated bank angle of a road surface estimated by a bank angle estimating device mounted on a vehicle according to a vehicle speed, and the estimation And a rate limiter for limiting the rate of change so that the rate of change of the bank angle does not exceed the limit value.

  According to this configuration, the limit value is set according to the vehicle speed as the behavior amount of the vehicle, and the rate of change of the estimated bank angle is limited so as not to exceed the set limit value. Even when there is a large change (abrupt acceleration or sudden deceleration), it is possible to prevent the estimated bank angle from changing abruptly more than necessary and to prevent the estimated bank angle from becoming unstable. .

  Further, the bank angle limiting device according to the present invention is based on the turning direction of the vehicle and the estimated bank angle of the road surface estimated by the bank angle estimating device mounted on the vehicle, whether or not the road surface is an inverse bank. And a limiter for limiting the estimated bank angle so that the estimated bank angle does not exceed a predetermined limit value when it is determined that the bank is the reverse bank.

  According to this configuration, in the case of the reverse bank, the estimated bank angle is limited so as not to exceed the limit value. Therefore, erroneous estimation of the estimated bank angle is prevented, and the value of the estimated bank angle is invalid. You can avoid falling into stability.

  According to the present invention, when the amount of vehicle behavior changes greatly, or when the road surface is an inverse bank, the estimated bank angle is limited so that the estimated bank angle value does not become unstable. be able to.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, a bank angle limiting device 10A according to a first embodiment of the present invention will be described with reference to FIG.

  The bank angle limiting device 10A is connected between a bank angle estimating device and a yaw rate sensor mounted on a vehicle (not shown), and a control device (ECU composed of a microcomputer) for controlling the behavior of the vehicle. It is possible to filter (limit) the estimated bank angle of the road surface on which the vehicle travels, which is estimated by the bank angle estimation device, and output the filtered bank angle to the ECU. In this case, the bank angle limiting device 10 </ b> A includes a low-pass filter unit 12 and a vehicle behavior determination unit 14. The configurations and functions of the bank angle estimation device, the yaw rate sensor, and the ECU mounted on the vehicle are disclosed in Patent Documents 1 and 2, and in this specification, detailed descriptions thereof will be given. Omitted.

  The low-pass filter unit 12 includes a low-pass filter 16 and a changeover switch 18. In this case, the input port 18a and the output port 18c are connected by the input of the control signal from the vehicle behavior determination unit 14 to the input port 18d of the changeover switch 18, while the input of the control signal to the input port 18d is stopped. The connection between the input port 18a and the output port 18c is switched to the connection between the input port 18b and the output port 18c. The vehicle behavior determination unit 14 includes an absolute value conversion unit 20, a threshold storage unit 22, and a determination unit 24.

  Next, the operation of the bank angle limiting device 10A will be described.

  The bank angle estimation device estimates the bank angle based on the vehicle behavior amount such as the vehicle speed, the yaw rate, and the lateral acceleration, and outputs the estimated bank angle (estimated bank angle) to the low-pass filter unit 12.

  On the other hand, when the yaw rate sensor detects the yaw rate of the vehicle and the differential value of the detected yaw rate is input to the vehicle behavior determination unit 14, the absolute value conversion unit 20 of the vehicle behavior determination unit 14 determines the derivative of the yaw rate. The value is converted into an absolute value and output to the determination unit 24.

  The determination unit 24 reads a predetermined threshold value stored in the threshold value storage unit 22, compares the read threshold value with the absolute value, and the absolute value is larger than the threshold value (absolute value> threshold). Is determined that the value of the estimated bank angle estimated by the bank angle estimator is unstable, and the control signal (predetermined value) is applied to the input port 18d of the changeover switch 18. Output an amplitude level signal). The changeover switch 18 connects the input port 18a and the output port 18c when a control signal is input to the input port 18d. Thereby, the low-pass filter 16 passes the low frequency component below a predetermined cut-off frequency among the estimated bank angles. The low-frequency component signal output from the low-pass filter 16 (the estimated bank angle that has passed through the low-pass filter 16) is supplied to the ECU as a signal necessary for controlling the behavior of the vehicle via the input port 18a and the output port 18c. Is done.

  On the other hand, the determination unit 24 compares the absolute value with the threshold value, and when the absolute value is equal to or less than the threshold value (absolute value ≦ threshold value), the behavior of the vehicle is small and It is determined that the value is not an unstable value, and then the control signal output to the input port 18d of the changeover switch 18 is stopped. Thereby, the changeover switch 18 switches the connection between the input port 18a and the output port 18c to the connection between the input port 18b and the output port 18c due to the stop of the input of the control signal to the input port 18d. As a result, the estimated bank angle (estimated bank angle not passing through the low-pass filter 16) from the bank angle estimation device is directly supplied to the ECU via the input port 18b and the output port 18c.

  As described above, the bank angle limiting device 10A according to the first embodiment includes the low-pass filter unit 12 including the low-pass filter 16 and whether the vehicle behavior amount (differential value of the yaw rate) is greater than a predetermined threshold value. And the low-pass filter unit 12 has a bank angle estimation device mounted on the vehicle when the vehicle behavior determination unit 14 determines that the behavior amount is greater than the threshold value. The estimated bank angle of the road surface estimated by the vehicle is output through the low-pass filter 16, while the estimated bank angle is directly output when the vehicle behavior determining unit 14 determines that the behavior amount is equal to or less than the threshold value. .

  Thus, when the behavior amount of the vehicle is larger than the threshold value, the estimated bank angle is output via the low-pass filter 16, so even if the behavior amount changes greatly, the estimated bank angle The estimated bank angle value can be prevented from becoming unstable.

  On the other hand, when the behavior amount of the vehicle is equal to or less than the threshold value, the estimated bank angle is directly output without passing through the low-pass filter 16, so that the phase delay of the estimated bank angle can be suppressed.

  In this case, if the differential value of the yaw rate detected by the yaw rate sensor mounted on the vehicle is used as the behavior amount of the vehicle, the estimated bank angle can be reliably limited when the vehicle makes a large turn.

  Next, a bank angle limiting device 10B according to the second embodiment will be described with reference to FIG.

  This bank angle limiting device 10B is adapted to a rate limiter 30 that limits the amount of time change (time change rate) of the estimated bank angle so as not to exceed a predetermined limit value, and the vehicle speed detected by a vehicle speed sensor mounted on the vehicle. A limit value setting unit 33 (an upper limit value setting unit 32 and a gain amplifier 34) for setting the limit value.

  Next, the operation of the bank angle limiting device 10B will be described.

  The vehicle speed sensor detects the vehicle speed and outputs it to the upper limit setting unit 32. The upper limit value setting unit 32 sets the upper limit value of the time change amount as a limit value according to the vehicle speed (the upper limit value of the positive time change amount when the estimated bank angle increases rapidly as the vehicle suddenly accelerates). ) And the determined upper limit value is output to the rate limiter 30 and the gain amplifier 34. The gain amplifier 34 sets a value obtained by multiplying the input upper limit value by (−1) to a lower limit value of the time change amount corresponding to the vehicle speed (the estimated bank angle is abruptly increased with sudden deceleration of the vehicle). And output to the rate limiter 30 as the lower limit of the negative time change amount when decreasing.

  On the other hand, the bank angle estimation device outputs the estimated bank angle to the rate limiter 30.

  The rate limiter 30 limits the estimated bank angle so that the amount of change over time does not exceed the limit value, and supplies the estimated bank angle after the limit to the ECU as a signal necessary for controlling the behavior of the vehicle.

  Specifically, when the time change amount of the estimated bank angle exceeds the upper limit value (time change amount> upper limit value), the rate limiter 30 causes the estimated bank to increase with time due to rapid acceleration of the vehicle. It is determined that the angle increases rapidly, and then the time change amount is forcibly limited to the upper limit value, and the estimated bank angle after limitation is supplied to the ECU.

  Further, when the amount of time change is less than the lower limit value (time change amount <lower limit value), the rate limiter 30 rapidly decreases the estimated bank angle with time due to rapid deceleration of the vehicle. Then, the time change amount is forcibly limited to the lower limit value, and the estimated bank angle after limitation is supplied to the ECU.

  Further, the rate limiter 30 is configured such that when the time change amount is between the upper limit value and the lower limit value (lower limit value ≦ time change amount ≦ upper limit value), the time elapses even if the vehicle speed changes. On the other hand, it is determined that the estimated bank angle does not change suddenly, the restriction on the estimated bank angle is not performed, and the estimated bank angle is supplied to the ECU as it is.

  As explained above, the bank angle limiting device 10B according to the second embodiment is the limit value of the rate of change of the estimated bank angle of the road surface estimated by the bank angle estimating device mounted on the vehicle (the upper limit value for the amount of time change and A limit value setting unit 33 for setting the lower limit value) according to the vehicle speed, and a rate limiter 30 for limiting the rate of change so that the time change amount of the estimated bank angle does not exceed the limit value.

  Accordingly, the limit value is set according to the vehicle speed as the behavior amount of the vehicle, and the time change amount of the estimated bank angle is limited so as not to exceed the set limit value, so that the vehicle speed greatly changes. Even in the case of (abrupt acceleration or sudden deceleration), it is possible to prevent the estimated bank angle from changing abruptly more than necessary and to prevent the estimated bank angle from becoming unstable.

  Next, a bank angle limiting device 10C according to the third embodiment will be described with reference to FIGS. 3A to 5.

  3A to 4B are diagrams for explaining banks in the curve 40. FIG.

  As shown in FIGS. 3A and 4A, the bank in the curve 40 includes a bank having a low inside and a high outside, as shown in FIGS. 3A and 4A, and a bank having a high inside and an outside, as shown in FIGS. 3B and 4B. There is a so-called reverse bank.

  Here, when the vehicle 42 travels along the curve 40 and the actual bank angle is θ or −θ, the bank angle θ is estimated by estimating the bank angle −θ or θ of the reverse bank in FIGS. 3B and 4B. There is a possibility that (−θ) is erroneously estimated and the value of the estimated bank angle becomes unstable.

  In FIGS. 3A to 4B, on the left side of the curve 40, the angle formed by the horizontal direction and the road surface is the bank angle θ or −θ, the left rotation direction is the positive direction (+ θ), and the right rotation direction is the negative direction ( −θ). Also, in FIGS. 3A to 4B, the counterclockwise direction (see FIGS. 3A and 3B) with respect to the axis of the alternate long and short dash line along the front-rear direction of the vehicle 42 is the positive direction (+ u) of the yaw rate. The direction clockwise with respect to the axis of the chain line (see FIGS. 4A and 4B) is the negative direction (−u) of the yaw rate.

  Therefore, the bank angle limiting device 10C according to the third embodiment employs the configuration shown in the schematic block diagram of FIG. 5 to prevent erroneous estimation of the estimated bank angle, and the value of the estimated bank angle is unstable. To avoid falling into.

  That is, the bank angle limiting device 10C sets the limiter 70 for limiting the estimated bank angle so as not to exceed a predetermined limit value when the curve 40 is an inverse bank (see FIGS. 3B and 4B) and the limit value. Limit value setting unit 71 (upper limit value setting units 52 and 56, lower limit value setting units 50 and 58, allowable value output units 54, 60 and 68, threshold value storage unit 62, determination unit 64, and changeover switch 66).

  Next, the operation of the bank angle limiting device 10C will be described.

  The yaw rate sensor mounted on the vehicle 42 detects the yaw rate, and outputs the detected yaw rate to the upper limit value setting unit 56, the lower limit value setting unit 50, and the determination unit 64.

  The lower limit value setting unit 50 determines the lower limit value of the estimated bank angle as the limit value according to the yaw rate (the limit value in the negative direction of the estimated bank angle when the curve 40 is the reverse bank of FIG. 3B). The determined lower limit value is output to the allowable value output unit 54.

  Further, the upper limit value setting unit 56 sets the upper limit value of the estimated bank angle as a limit value corresponding to the yaw rate (the limit value in the forward direction of the estimated bank angle when the curve 40 is the reverse bank of FIG. 4A). The determined upper limit value is output to the allowable value output unit 60.

  Furthermore, the upper limit value setting unit 52 stores a condition that there is no upper limit (limit value) of the estimated bank angle, while the lower limit value setting unit 58 does not have a lower limit (limit value) of the estimated bank angle. The condition of the effect is stored.

  Therefore, the allowable value output unit 54 outputs the lower limit value from the lower limit value setting unit 50 and the condition that there is no upper limit read from the upper limit value setting unit 52 to the input port 66a of the changeover switch 66. The allowable value output unit 60 outputs the upper limit value from the upper limit value setting unit 56 and the condition that there is no lower limit read from the lower limit value setting unit 58 to the input port 66b of the changeover switch 66.

  The determination unit 64 compares the yaw rate from the yaw rate sensor with 0 as a threshold stored in the threshold storage unit 62 (when the vehicle 42 goes straight), and if the yaw rate is 0 or more (yaw rate ≧ 0) ), It is determined that the vehicle 42 turns in the forward direction (see FIGS. 3A and 3B), and a control signal is output to the input port 66 d of the changeover switch 66. The change-over switch 66 connects the input port 66a and the output port 66c when a control signal is input to the input port 66d, and sets a condition that there is no lower limit value and no upper limit from the allowable value output unit 54. Output to the output unit 68.

  If the yaw rate is less than 0 (yaw rate <0), the determination unit 64 determines that the vehicle 42 turns in the negative direction (see FIGS. 4A and 4B), and outputs a control signal to the input port 66d. To stop. The changeover switch 66 switches the connection between the input port 66a and the output port 66c to the connection between the input port 66b and the output port 66c due to the stop of the input of the control signal to the input port 66d. The condition that there is no upper limit value and no lower limit is output to the allowable value output unit 68.

  The allowable value output unit 68 outputs a condition indicating that there is no lower limit and no upper limit input from the allowable value output unit 54 via the changeover switch 66 to the limiter 70, or from the allowable value output unit 60 to the changeover switch 66. The condition that there is no upper limit value and no lower limit input via, is output to the limiter 70.

  The limiter 70 is input from the allowable value output unit 68 under the condition that there is no upper limit and the lower limit value (limit value when the vehicle 42 turns in the forward direction with the yaw rate> 0), or the upper limit value and the lower limit value. Based on the condition that there is no (yaw rate <0 and the limit value when the vehicle 42 turns in the negative direction) and the estimated bank angle, it is determined whether or not the curve 40 is a reverse bank. When the bank is determined to be a bank, the estimated bank angle is limited so that the estimated bank angle does not exceed the limit value, and the estimated bank angle after the limitation is supplied to the ECU as a signal necessary for controlling the behavior of the vehicle. To do.

  Specifically, the limiter 70 is a case where the limit value input from the allowable value output unit 68 is a condition that there is no upper limit and a lower limit value, and the estimated bank angle is a negative value (see FIG. 3B). If the estimated bank angle value is less than the lower limit value (estimated bank angle <lower limit value), the estimated bank angle value is forcibly limited to the lower limit value. Then, the estimated estimated bank angle is supplied to the ECU.

  Further, the limiter 70 is a condition that the limit value input from the allowable value output unit 68 is a condition that the upper limit value and the lower limit value are not present, and the estimated bank angle is a positive value (see FIG. 4B). If the estimated bank angle value exceeds the upper limit value (estimated bank angle> upper limit value), the estimated bank angle value is forcibly limited to the upper limit value. Then, the estimated bank angle after limitation is supplied to the ECU.

  Furthermore, even when the limiter 70 determines that the bank is a normal bank (see FIGS. 3A and 4A) or an inverse bank (see FIGS. 3B and 4B), the estimated bank angle value is below the lower limit value. If the estimated bank angle value does not exceed the upper limit (within the range of the reverse bank that can exist on general roads), the estimated bank angle is not limited and the estimated bank angle is not limited. The bank angle is supplied to the ECU as it is.

  As described above, the bank angle limiting device 10C according to the third embodiment is based on the turning direction of the vehicle and the estimated bank angle of the road surface estimated by the bank angle estimating device mounted on the vehicle. It is determined whether (curve 40) is a reverse bank, and when it is determined that the curve is the reverse bank, the estimated bank angle does not exceed a predetermined limit value (upper limit value or lower limit value). It has a limiter 70 for limiting the bank angle.

  As a result, in the case of an inverse bank, the estimated bank angle is limited so as not to exceed the limit value, so that an erroneous estimation of the estimated bank angle is prevented so that the estimated bank angle value does not become unstable. Can be.

  The present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted based on the description in the specification and the drawings.

1 is a schematic block diagram of a bank angle limiting device according to a first embodiment. It is a schematic block diagram of the bank angle limiting device concerning a 2nd embodiment. 3A and 3B are diagrams for explaining banks in a curve. 4A and 4B are diagrams for explaining banks in a curve. It is a schematic block diagram of the bank angle limiting device concerning a 3rd embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10A-10C ... Bank angle limiter 12 ... Low pass filter part 14 ... Vehicle behavior determination part 16 ... Low pass filter 18, 66 ... Changeover switch 18a, 18b, 18d, 66a, 66b, 66d ... Input port 18c, 66c ... Output port 20 ... absolute value conversion units 22, 62 ... threshold storage unit 24 ... determination unit 30 ... rate limiter 32 ... upper limit value setting unit 33, 71 ... limit value setting unit 34 ... gain amplifier 40 ... curve 42 ... vehicle 50, 58 ... lower limit value Setting unit 52, 56 ... Upper limit setting unit 54, 60, 68 ... Allowable value output unit 64 ... Determination unit 70 ... Limiter

Claims (4)

A low-pass filter unit including a low-pass filter, and a vehicle behavior determination unit that determines whether the behavior amount of the vehicle is greater than a predetermined threshold,
When the vehicle behavior determining unit determines that the behavior amount is greater than the threshold, the low-pass filter unit uses the low-pass filter to calculate an estimated bank angle of a road surface estimated by a bank angle estimation device mounted on the vehicle. On the other hand, when the vehicle behavior determination unit determines that the behavior amount is equal to or less than the threshold value, the bank angle limiting device directly outputs the estimated bank angle. The apparatus of claim 1.
The bank angle limiting device, wherein the behavior amount is a differential value of a yaw rate of the vehicle. A limit value setting unit for setting the limit value of the rate of change of the estimated bank angle of the road surface estimated by the bank angle estimation device mounted on the vehicle according to the vehicle speed;
A rate limiter for limiting the rate of change so that the rate of change of the estimated bank angle does not exceed the limit value;
A bank angle limiting device comprising:   Based on the turning direction of the vehicle and the estimated bank angle of the road surface estimated by the bank angle estimation device mounted on the vehicle, it is determined whether or not the road surface is a reverse bank, and is determined to be the reverse bank And a limiter for limiting the estimated bank angle so that the estimated bank angle does not exceed a predetermined limit value.

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