JP3917336B2 - Stop lamp switch abnormality detection device and tire abnormality detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention includes a stop lamp switch abnormality detection device for detecting an abnormality relating to a stop lamp that is lit in conjunction with a brake operation in an automobile, and also includes a stop lamp switch abnormality detection device and detects an abnormality in tire air pressure. The present invention relates to a tire abnormality detection device.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, stop lamps that are turned on in conjunction with a brake operation such as stepping on a brake pedal are well known. This stop lamp is generally connected to a stop lamp switch that is turned on in conjunction with the operation of the brake pedal. This stop lamp switch not only lights the stop lamp but also detects the vehicle status. It is also used to do.
[0003]
As one of the devices that use the stop lamp switch for detecting the vehicle state as described above, for example, a tire abnormality detection device described in JP-A-8-156549 is known. This publication describes a device that detects an abnormality in tire air pressure from a change in tire angular velocity and notifies the driver of this abnormality. Further, the change in the angular velocity of the tire also occurs due to factors other than the tire air pressure. For example, the variation in the angular velocity of each wheel varies depending on the wheel load state and the road surface friction coefficient during braking. Therefore, in the above-described prior art, when the stop lamp switch is turned on, it is assumed that braking is being performed and tire abnormality determination is stopped.
[0004]
[Problems to be solved by the invention]
In the circuit having the stop lamp and the stop lamp switch described above, a failure may occur in which the stop lamp remains in a lit state because the contact of the stop lamp switch is fixed or the circuit is short-circuited. It was. However, conventionally, there has been no device for detecting such a failure when it occurs.
[0005]
Further, in the above-described tire abnormality detection device, when the above-described abnormality occurs in the stop lamp switch, a signal indicating that braking is being performed remains output, and a correct tire abnormality determination cannot be made. There was a problem that it might lead to detection.
[0006]
The present invention has been made by paying attention to the above-described conventional problems, and has as its first object to provide a novel device capable of detecting when an abnormality occurs in a stop lamp switch, and further, a tire. A second object of the abnormality detection device is to detect when a failure occurs in the stop lamp switch, to prevent erroneous detection, and to detect air pressure abnormality with high accuracy.
[0007]
[Means for Solving the Problems]
In order to achieve the first object described above, the stop lamp switch abnormality detecting device according to claim 1 detects a wheel speed detecting means for detecting a rotation speed of each wheel of the vehicle, and detects an ON operation state of the stop lamp. An ON operation detecting means for performing the operation, a first comparing means for detecting that the wheel speed exceeds the first threshold value, and a second smaller than the first threshold value after the wheel speed exceeds the first threshold value. The second comparison means for detecting that the threshold value has been reached, and the number of times the detection by the second comparison means has been performed since the detection by the first comparison means with the stop lamp still operating. Stop lamp switch abnormality determining means for determining whether or not the measurement condition is satisfied, and determining that the stop lamp switch is abnormal when the frequency measurement condition is continuously satisfied for a predetermined number of times. And features.
[0008]
In addition, as described in claim 2, in the stop lamp switch abnormality detection device according to claim 1, it is preferable that the second threshold value is 0 km / h.
[0009]
In addition, in the stop lamp switch abnormality detecting device according to claim 1 or 2, as described in claim 3, when the stop lamp switch abnormality determining means determines that there is an abnormality, a notification that notifies the driver of the abnormality is provided. It is preferable to provide means.
[0010]
In order to achieve the second object described above, the invention according to claim 4 compares the wheel speed of each wheel to detect that the tire air pressure is decreasing under a predetermined condition. In the tire abnormality detection device provided with tire abnormality detection means for executing detection control, wheel speed detection means for detecting the rotation speed of each wheel of the vehicle, ON operation detection means for detecting the ON operation state of the stop lamp, The first comparison means for detecting that the wheel speed has exceeded the first threshold value, and the wheel speed has reached the second threshold value smaller than the first threshold value after the first threshold value has been exceeded. Whether the second comparison means for detecting this and the number measurement condition for the detection by the second comparison means after the detection by the first comparison means in the state in which the stop lamp remains ON Judgment or not And a stop lamp switch abnormality detecting device for determining that the stop lamp switch is abnormal when the frequency measurement condition is continuously established for a predetermined number of times. When the means determines that the stop lamp switch is abnormal, there is provided a prohibition determination means for prohibiting the determination of a decrease in air pressure in the tire abnormality detection means.
[0011]
In order to achieve the second object described above, the invention according to claim 5 compares the wheel speed of each wheel and detects that the tire air pressure is decreasing under a predetermined condition. Tire abnormality detection means for performing detection control and prohibition determination means for prohibiting determination of a decrease in air pressure by the tire abnormality detection means when the vehicle deceleration exceeds a deceleration threshold value In the detection device, wheel speed detection means for detecting the rotational speed of each wheel of the vehicle, ON operation detection means for detecting the ON operation state of the stop lamp, and detecting that the wheel speed has exceeded the first threshold value. First comparison means, second comparison means for detecting that the wheel speed has reached a second threshold value smaller than the first threshold value after exceeding the first threshold value, and the stop lamp is turned on. In the state that A determination is made as to whether or not a condition for counting the number of times detected by the second comparing means after the detection by the first comparing means is satisfied, and a stop lamp switch is set when the number of measuring conditions is continuously satisfied for a predetermined number of times. A stop lamp switch abnormality detecting device for determining an abnormality, and when the stop lamp switch abnormality determining device determines that the stop lamp switch is abnormal, the prohibition determining device decelerates. The threshold value is configured to be shifted to the side of increasing the sensitivity of the prohibition determination.
[0012]
Operation and effect of the invention
In the stop lamp switch abnormality detection device according to claim 1, after the wheel speed exceeds the first threshold value in a state where the stop lamp is still ON, further to the second threshold value. When it decreases, the stop lamp switch abnormality determining means establishes the number-of-times measurement condition, and further determines that an abnormality has occurred in the stop lamp switch when the number-of-times measurement condition continues to be established a predetermined number of times.
[0013]
That is, in the stop lamp, the circuit may remain closed due to the fixing of the stop lamp switch and the stop lamp may remain lit. When the stop lamp switch is normal, the stop lamp switch does not repeatedly increase from the predetermined vehicle speed (second threshold value) to the predetermined vehicle speed (first threshold value) while the stop lamp is lit. If an abnormality has occurred, this is repeated. Therefore, the abnormality of the stop lamp switch can be detected by detecting such a traveling state.
As described above, according to the first aspect of the present invention, it is possible to provide a novel device capable of detecting an abnormality of the stop lamp switch with high accuracy.
[0014]
In the second aspect of the invention, the second threshold value is 0 km / h, that is, the vehicle is stopped, and therefore, the vehicle stops from a predetermined vehicle speed (first threshold value) while the stop lamp remains on. → Predetermined vehicle speed → It is determined that the stop lamp switch is abnormal when the vehicle is continuously stopped.
That is, the first threshold value and the second threshold value are values that are included in a driving pattern that is likely to cause a speed change that cannot occur when braking and is likely to occur in a normal driving state. It is preferable. Therefore, the first threshold value is preferably within a speed range that is normally reached when starting running, for example, within a range of 20 km / h to 40 km / h, and the second threshold value is a low speed range, For example, it is preferably within a range of 15 km / h to 0 km / h. If such a speed range is set, the two speed ranges are not traversed a plurality of times even when braking is performed. However, the closer these two speeds are, and the higher the second threshold value is, the more likely the abnormality determination condition is to be satisfied depending on the running pattern even if braking is being performed. Is slightly higher. For example, the speed may increase or decrease while braking, such as when traveling in a traffic jam.
On the other hand, in the invention according to claim 2, by setting the second threshold value to 0 km / h, the difference from the first threshold value is widened and it is not included in the more normal traveling pattern. Therefore, the effect that the abnormality detection accuracy of the stop lamp switch is improved can be obtained.
[0015]
In the stop lamp switch abnormality detecting device according to the third aspect, when the stop lamp switch abnormality determining means determines that there is an abnormality, the notifying means notifies the driver of this. Therefore, the driver can immediately respond to the abnormality of the stop lamp switch. Note that the notification means includes lighting of a lamp, a warning sound such as a buzzer, a voice warning, or a display on a display screen in the instrument panel.
[0016]
In the tire abnormality detection device according to the fourth aspect, when the stop lamp switch abnormality detection device determines that the stop lamp switch is abnormal, the determination of a decrease in air pressure is prohibited. Therefore, it is possible to improve the tire pressure abnormality detection accuracy without determining the tire pressure abnormality based on the signal from the ON operation detecting means corresponding to the abnormal stop lamp switch state.
[0017]
In the tire abnormality detection device according to claim 5, when the tire abnormality detection means makes an abnormality determination, if the vehicle deceleration exceeds a predetermined deceleration threshold, the wheel speed is affected by braking. Appears. Therefore, since the accuracy of determining the air pressure abnormality due to the wheel speed is reduced, the prohibition determining means prohibits the air pressure decrease determination by the tire abnormality detecting means.
[0018]
Further, when the stop lamp switch abnormality determining means determines that the stop lamp switch is abnormal, the deceleration threshold value is shifted to increase the sensitivity of prohibition determination. That is, when an abnormality occurs in the stop lamp switch, the detection result of the ON operation detecting means cannot be used for tire abnormality determination. Accordingly, by shifting the deceleration threshold value to increase the sensitivity of the prohibition determination regarding deceleration, it is possible to make a determination according to braking with high accuracy without using the detection result of the ON operation detection means. Accordingly, when a predetermined deceleration occurs even when the stop lamp switch is abnormal, it is determined that braking has been performed, and determination of a decrease in air pressure is prohibited, thereby improving tire abnormality detection accuracy.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
(Embodiment 1)
The vehicle behavior detection device according to the first embodiment corresponds to the stop lamp switch abnormality detection device according to claims 1 to 3 and also corresponds to the tire abnormality detection device according to claim 4.
[0020]
FIG. 1 is a system diagram of a vehicle on which a vehicle control device having a stop lamp switch abnormality detection device and a tire abnormality detection device according to Embodiment 1 is mounted. The vehicle control device corresponds to the detected vehicle behavior. It is configured to control the operation of the brake unit BU, the driving state of the engine ENG, and the shift of the automatic transmission AT.
[0021]
In the figure, the MCU is a main control unit, which determines the vehicle behavior based on the inputs from the sensors 1, 2, 3 and the stop lamp switch 4 for detecting the vehicle behavior and outputs a control signal to the brake unit BU. In addition, it is configured to output necessary signals to the AT control unit ATCU that controls the automatic transmission AT and the ENG control unit ENGCU that controls the driving of the engine ENG.
[0022]
The main control unit MCU has, as sensors for detecting vehicle behavior, a wheel speed sensor 1 for detecting the wheel speed of each wheel, a steering angle sensor 2 for detecting a steering angle, and a yaw rate sensor 3 for detecting the yaw rate of the vehicle. And a stop lamp switch 4 that is turned on in conjunction with depression of a brake pedal (not shown). The wheel speed sensor 1 corresponds to the wheel speed detecting means in the claims, and is a well-known sensor that outputs a predetermined number N of pulses when the wheel W rotates once. In the present embodiment, For example, N = 42.
[0023]
Further, the main control unit MCU includes ON operation detection means, first comparison means, and second comparison means, which are constituent elements of the stop lamp switch abnormality detection device of the claims, and the tire abnormality detection device. Tire abnormality detecting means and prohibition determining means, which are constituent elements of
[0024]
The tire abnormality detection device determines whether or not there is an abnormality in the air pressure of each wheel W and notifies the abnormality when there is an abnormality. This tire abnormality detection is basically described later. Is based on the following thinking. In other words, if the tire pressure of any of the four wheels falls below the normal pressure, the tire radius of this wheel becomes smaller than the tire radius of the normal pressure, so that the wheel speed of this abnormal wheel is compared with the wheel speed of the normal wheel. Slightly faster. Thus, when the wheel speed of a certain wheel is slightly higher than that of the other wheels for a predetermined time or more, it is determined that the tire air pressure of that wheel has decreased.
[0025]
Hereinafter, tire abnormality detection based on this concept will be described with reference to a flowchart.
In executing the tire abnormality detection control, first, wheel speed pulse measurement is executed based on the flowchart shown in FIG.
The wheel speed pulse measurement is performed for each wheel speed sensor. First, in step 91, the pulse count NCNTxx is incremented every time a pulse obtained from each wheel speed sensor is input, and in step 92, FRC ( Free running counter) The period TCNTxx is obtained by adding the capture values. The wheel speed sensor is configured to generate a pulse having a frequency corresponding to the rotation speed of the wheel W, and the pulse count NCNT for two rotations of the wheel W output from the wheel speed sensor is used for two rotations of the tire. Each wheel speed Vxx is obtained by dividing by the cycle TCNT. Here, xx represents each of front right FR, front left FL, rear right RR, and rear left RL.
[0026]
FIG. 3 is a flowchart showing the overall control flow of tire abnormality detection control. First, in step 101, the wheel speed Vxx is obtained from the number of pulses NCNTxx integrated in the pulse count for each wheel and the cycle TCNTxx, and then in step 102. The pulse number NCNTxx and the cycle TCNTxx are cleared to zero.
[0027]
Steps 103 to 113 below are used to determine whether or not a tire abnormality warning is to be determined, which corresponds to the prohibition determination means in the claims and does not satisfy a predetermined determination condition. In the case of an appropriate running state, one flow is finished without making an alarm judgment.
[0028]
In step 103, it is determined whether or not the lowest value of the four wheels is at a low speed of less than 15 km / h, which is a predetermined speed, and at a low speed of less than 15 km / h, the alarm is not judged. Proceeding to 119, when 10 ms, which is the time for executing one control flow, has elapsed, one flow is finished, and if it is 15 km / h or more in step 103, the process proceeds to step 104. That is, during low-speed traveling, there is an influence on the wheel speed due to road surface unevenness and the like, so that an alarm judgment is not made as inappropriate for determining a tire air pressure abnormality based on the wheel speed.
[0029]
In step 104, it is determined whether or not stop lamp switch abnormality processing is being executed. If the abnormality processing is being executed, the determination is canceled because the stop lamp switch 4 has failed and the reliability of the above determination is low. Then, the process proceeds to step 119, and the process proceeds to step 104b if the abnormality process is not being executed.
[0030]
In step 104b, it is determined whether or not the stop lamp switch 4 is turned on, that is, whether or not braking is in progress. If the brake is being applied, the process proceeds to step 119 without making an alarm determination. Proceed to step 105. That is, at the time of braking, there is an influence on the wheel speed due to tire slip or the like, so that the alarm judgment is not performed as inappropriate for judging the tire air pressure abnormality based on the wheel speed.
[0031]
In step 105, the acceleration ACCxx of each wheel is calculated. In this case, a calculation is performed based on a value obtained by subtracting the previous (10 ms before) wheel speed Vxx 10 ms before from the current wheel speed Vxx. In the following step 106, the highest value of the acceleration ACCxx of each wheel is obtained, it is determined whether or not this value is larger than a predetermined threshold value +0.1 g, and an alarm is issued when acceleration is larger than +0 and 1 g. The process proceeds to step 119 without making a determination, and proceeds to step 107 if it is less than +0.1 g. In step 107, the lowest value of the acceleration of the four wheels is obtained, and the process proceeds to step 119 without making an alarm judgment at the time of deceleration when this value is lower than a predetermined value of -0.1 g. In other words, even when the vehicle is accelerating or decelerating more than a predetermined value, the wheel speed is affected by tire slips, etc., so an alarm judgment is made as inappropriate for determining tire pressure abnormality based on the wheel speed. Absent.
[0032]
Next, at step 108, the wheel speed ratio HiVR of the right front and rear wheels and the wheel speed ratio HiVL of the left front and rear wheels are respectively determined.
HiVR = (VFR / VRR) −1, HiVL = (VFL / VRL) −1
Obtained by the following equation. These front-to-back ratios HiVR and HiVL are used to determine whether there is an abnormality in air pressure in the front and rear, respectively. For example, if there is an air pressure abnormality in the front wheels, HiVR and HiVL are positive values, and the air pressure in the rear wheels is abnormal. When there is, HiVR and HiVL are negative values.
[0033]
Subsequently, in step 109, it is determined whether or not the larger value of the two front-to-back ratios HiVR and HiVL exceeds a predetermined threshold value of 1%. Thus, even when the front-to-back ratio is larger than the threshold value, it is determined that the wheel speed is abnormal due to a factor other than a decrease in tire air pressure, and a warning is given as inappropriate for determining the tire air pressure abnormality based on the wheel speed. The process proceeds to step 119 without making a determination.
[0034]
On the other hand, in step 109, when the larger value of the two front-to-back ratios HiVR and HiVL is equal to or less than the threshold value (1%), the routine proceeds to step 110, where the select lateral acceleration YGS is calculated.
[0035]
The selected lateral acceleration YGS in step 110 is the difference between the front wheel lateral acceleration YGF obtained based on the left and right wheel speed difference of the front wheel and the rear wheel lateral acceleration YGR obtained based on the left and right wheel speed difference of the rear wheel. The value is a value selected from either one, and the key is the lateral acceleration obtained from the wheel speed.
[0036]
If the selected lateral acceleration YGS is obtained in step 110, the process proceeds to step 111, where it is determined whether or not the absolute value | YGS | of the selected lateral acceleration is larger than a predetermined threshold value 0.1g, and the absolute value of the lateral acceleration | If YGS | is larger than the threshold value, the vehicle is not in a steady driving state such as turning, so the routine proceeds to step 119 without making an alarm judgment, and one flow is completed. The absolute value of the lateral acceleration | YGS | Proceeds to step 112 when is less than the threshold (0.1 g).
[0037]
In step 112, the turning radius RS is calculated based on the following calculation.
RS = {(VxR + VxL) / (VxR−VxL)} × Kb
Here, x indicates either the front wheel F or the rear wheel R. Kb is a preset coefficient. In this step 112, the main point is that if there is a difference between the left and right wheels, the turning radius is calculated by multiplying the coefficient as the difference due to the difference between the turning inner and outer wheels. The +/- of the values obtained by the times will be different.
[0038]
In the following step 113, it is determined whether or not the turning radius R is less than a threshold value of 30 m. When turning with a radius of less than 30 m, the wheel speed differs greatly depending on the turning inner and outer wheels, and the tire pressure abnormality cannot be determined by the wheel speed. From step 119, the flow proceeds to step 119 without making an alarm determination, and one flow is completed. When the turning radius R is equal to or greater than the threshold value 30m, the flow proceeds to step 114, where tire abnormality determination, that is, tire pressure reduction determination value D1 is set. Perform the desired calculation.
Note that a method for calculating the decompression determination value D1 will be described later based on the flowchart shown in FIG.
[0039]
In step 115, it is determined whether or not the pressure reduction determination value D1 is equal to or greater than a threshold value (0.5%) (whether or not the tire air pressure is abnormally decreased). To set the decompression flag to 1. Incidentally, the threshold value to be compared with the decompression judgment value D1 is a fixed value here. For example, 0.5% when the vehicle speed is 40 km / h and 0.3% when the vehicle speed is 80 km / h. It is preferable to change according to the vehicle speed. This is because a tire having a low air pressure has a small diameter at a relatively low rotational speed, but when the rotational speed is high, the tire swells outward and the diameter is increased, thereby reducing the diameter difference from the normal wheel. Therefore, it is preferable in terms of accuracy to change the threshold value according to the vehicle speed as described above. Note that the above-described calculation in step 114 and the comparison determination in step 115 correspond to the tire abnormality detection means in the claims.
[0040]
In the following step 117, it is determined whether or not the decompression flag is 1. When the decompression flag is set to 1, the routine proceeds to step 118 and an alarm operation is executed. As this alarm operation, a visual alarm operation such as turning on an alarm lamp or displaying on an in-vehicle monitor is executed, and an audio alarm such as a voice message or a buzzer is executed. The part that performs this process and the part that performs the operation correspond to the notification means in the claims.
[0041]
Next, the calculation processing flow of the selected lateral acceleration YGS in step 110 will be described with reference to the flowchart of FIG.
First, in step 201, the front wheel lateral acceleration YGF is calculated by the following formula based on the front wheel speeds VFR and VFL. Similarly, in step 202, the front wheel lateral acceleration YGR is calculated based on the rear wheel speeds VRR and VRL. Calculate with the following formula.
YGF = {(VFR + VFL) / (VFR−VFL)} × Kc
YGR = {(VRR + VRL) / (VRR−VRL)} × Kd
In the above equation, Kc and Kd are coefficients.
[0042]
In step 203, the absolute values of the front-rear ratios HiVR and HiVL are compared. If the left-wheel front-rear ratio HiVL is larger, the process proceeds to step 204. If the right-wheel front-rear ratio HiVR is larger, the process proceeds to step 207.
[0043]
In step 204, it is determined whether or not the left / right ratio HiVL of the left wheel is equal to or greater than 0. If it is equal to or greater than 0, it is determined that there is an abnormality in the front wheel and the process proceeds to step 206 to select the rear wheel lateral acceleration YGR as the selected lateral acceleration YGS. If it is less than 0, it is determined that there is an abnormality in the rear wheel, and the routine proceeds to step 207 where the front wheel lateral acceleration YGF is selected as the selected lateral acceleration YGS.
[0044]
Similarly, in Step 207, it is determined whether or not the front-rear ratio HiVR of the right wheel is equal to or greater than 0. If it is equal to or greater than 0, it is determined that there is an abnormality in the front wheel. The acceleration YGR is selected. If it is less than 0, it is determined that there is an abnormality in the rear wheel, and the routine proceeds to step 208, where the front wheel lateral acceleration YGF is selected as the selected lateral acceleration YGS.
[0045]
Next, the procedure for obtaining the pressure reduction judgment value D1 will be described with reference to FIG. 5. In step 301, D10 = (VFL / VFR) − (VRR / VRL)
The reference value D10 is obtained by the calculation of
D1 = D10−YGS × Ke
Is calculated based on the calculated select lateral acceleration YGS to obtain the reference value D10. That is, when turning, a difference in speed occurs between the inner and outer wheels, and this amount is corrected to improve accuracy. Ke is a coefficient.
[0046]
Next, the stop lamp switch abnormality process determined in step 104b will be described. FIG. 6 shows the control flow of stop lamp switch abnormality determination.
First, in step 601, it is determined whether or not the stop lamp switch 4 is ON (turned on). If it is ON, the process proceeds to step 602, and if it is not ON, the process proceeds to 604. A process of setting the stop lamp on flag FSTSON = 0 and setting the on counter CTSSON = 0 is executed. The on-counter CTSSON is a counter that measures the time during which the stop lamp switch 4 is ON.
[0047]
In step 602, it is determined whether the higher value of the wheel speeds VFR and VFL of the front wheels is 30 km / h or more corresponding to the first threshold value in the claims. If it is equal to / h or more, the process proceeds to step 603 to set the stop lamp on flag FSTSON to 1 and then proceeds to step 605. On the other hand, if it is less than 30 km / h, the process proceeds directly to step 605 without performing any processing. In addition, the part which performs determination of step 602 corresponds to the first comparison means in the claims.
[0048]
In step 605, it is determined whether the higher value of the wheel speeds VFR and VFL of the front wheels is 0 km / h corresponding to the second threshold value in the claims. In step 606, if it is not 0 km / h, one flow is finished. It should be noted that the portion for performing the determination in step 605 corresponds to the second comparison means in the claims.
[0049]
In step 606, it is determined whether or not the stop lamp on flag FSTSON = 1. If the stop lamp on flag FSTSON = 1, the process proceeds to step 607 and the count value of the on counter CTSSON is incremented by +1.
[0050]
In the next step 608, it is determined whether or not the on-counter CTSSON is 3 or more. If CTSSON ≧ 3, the routine proceeds to step 609, where stop lamp switch abnormality processing is executed. The stop lamp switch abnormality process is, for example, a process of turning on a fail lamp (not shown), displaying a failure of the stop lamp on the display screen, or giving a warning to that effect. This is a process to inform the driver of the stop lamp abnormality. The portion for executing the determination and processing in steps 606 to 608 corresponds to the stop lamp switch abnormality determining means in the claims, and the portion for executing the processing in step 609 is informing the claims. Corresponds to means.
In the subsequent step 610, the stop lamp on flag FSTSON = 0 is reset.
[0051]
Next, the operation of the first embodiment will be described.
The operation when the stop lamp switch 4 is fixed will be described based on the time chart of FIG.
When the stop lamp switch 4 is fixed, it is maintained in the ON state. When the wheel speed of the front wheels becomes 30 km / h or higher in this ON fixed state, the stop lamp on flag FSTSON is set to 1 (steps 601 → 602 → 603). If the wheel speed of the front wheels becomes 0 km / h by applying a brake or the like while the stop lamp on flag FSTSON = 1, the on-counter CTSSON is incremented by 1 (the flow of steps 605 → 606 → 607). Further, if the operation of incrementing the on-counter CTSSON by 1 is performed three times as described above, it is determined that the stop lamp switch 4 is abnormal, and stop lamp switch abnormality processing such as turning on the fail lamp is executed. (Step 608 → 609). That is, it is determined that an abnormality has occurred in the stop lamp switch 4 because the wheel speed cannot go between 30 km / h and 0 km / h three times with the brake pedal depressed.
[0052]
Further, when the stop lamp switch abnormality process is executed in this way, the tire abnormality determination is canceled in the tire abnormality detection control (the flow from step 104b to 119). Therefore, it is possible to increase the detection accuracy of the tire air pressure abnormality.
[0053]
When the stop lamp switch 4 is normal, each time the stop lamp switch 4 is turned OFF, the stop lamp ON flag FSSON and the ON counter CTSSON are cleared to 0, and the wheel speed is 0 km with the brake applied. The on-counter CTSSON is not counted up to 3 because there is no repeated increase from / h to 30 km / h. Therefore, the stop lamp switch abnormality process is not executed.
[0054]
(Embodiment 2)
Next, a second embodiment will be described. The second embodiment corresponds to the stop lamp switch abnormality detecting device according to claims 1 to 3 of the claims and the tire abnormality detecting device according to claim 5, and the main configuration and main operational effects are as follows. Since it is common to the first embodiment, description of common points is omitted, and only different points will be described.
In the second embodiment, in the tire abnormality detection control, the deceleration threshold value for determining whether or not to detect the tire abnormality detection based on the deceleration is set based on whether or not the stop lamp switch abnormality process is being executed. This is an example of making them different.
[0055]
FIG. 8 is a flowchart showing the flow of tire abnormality detection control in the second embodiment, and the same steps as those in the first embodiment are denoted by the same step numbers and description thereof is omitted.
[0056]
In the second embodiment, as shown in step 107b of the figure, when the minimum value of the wheel speed deceleration is equal to or less than the deceleration threshold value -KG, the change in the wheel speed is influenced by factors other than the tire air pressure. Therefore, the tire abnormality determination is canceled and the process proceeds to step 119. Here, the difference from the first embodiment is that in the first embodiment, the deceleration threshold value for performing this determination is a fixed value of −0.1, whereas in the second embodiment, This deceleration threshold value -KG is a variable.
[0057]
This deceleration threshold value -KG is determined by the processing of steps 104, 104b, 104c, and 104d following step 103. That is, in step 104b following step 103, it is determined whether or not the stop lamp switch 4 is ON. If STS = ON, the process proceeds to step 104 to determine whether or not stop lamp switch abnormality processing is being performed. To do. If the stop lamp switch abnormality process is not executed, the brake pedal is depressed and braking is performed, so that the detection of the tire air pressure abnormality is canceled and the routine proceeds to step 119.
[0058]
On the other hand, if stop lamp switch abnormality processing is being executed in step 104, the routine proceeds to step 104c where KG = 0.08. On the other hand, if the stop lamp switch 4 is not ON in step 104b, the process proceeds to step 104d to execute processing for setting KG = 0.1.
[0059]
That is, in the second embodiment, when the brake operation is not performed, the process proceeds from step 104b to 104d, and the deceleration threshold -KG is the same value as in the first embodiment -0.1. And On the other hand, when the stop lamp switch abnormality process is being executed even if the stop lamp switch 4 is ON, it is not possible to determine whether braking is being performed in the ON / OFF state of the stop lamp switch 4. When the stop lamp switch 4 is ON, the tire abnormality detection is returned to the flow of step 105 without canceling, while in step 107b, the deceleration threshold -KG is shifted to the side of increasing the sensitivity for canceling the tire abnormality detection. It is something to be made.
[0060]
Therefore, even when the stop lamp switch 4 is stuck, it is possible to continue detecting the tire pressure abnormality.
[0061]
As mentioned above, although embodiment was described based on drawing, this invention is not limited to these embodiment, The design change in the range which does not change the summary of this invention described in this specification is included. .
For example, the values of 30 km / h and 0 km / h are shown as the first threshold value and the second threshold value used for determining the abnormality of the stop lamp switch 4. As long as the step is followed, the speed does not repeat such a speed change, and the speed range is not limited to these values as long as it is included in the normal traveling pattern. Therefore, for example, a value in the range of 20 to 40 km / h can be used as the first threshold value, and a value in the range of 0 to 15 km / h can be used as the second threshold value.
In the first and second embodiments, as one of the conditions for determining whether to detect or cancel the tire abnormality, the wheel acceleration / deceleration is set to a predetermined threshold value (+0.1, −0.1). , −0.08), but this threshold value is not limited to the values shown in the first and second embodiments. For example, the sensitivity is increased during the execution of the stop lamp switch abnormality process. As the threshold value when shifted to the side, a threshold value within the range of +0.07 to -0.07 can be used.
[Brief description of the drawings]
1 is an overall configuration diagram of a vehicle control device including a stop lamp switch abnormality detection device and a tire abnormality detection device according to Embodiment 1;
FIG. 2 is a flowchart showing a control flow of wheel speed pulse measurement according to the first embodiment.
FIG. 3 is a flowchart showing a control flow of tire abnormality detection according to the first embodiment.
FIG. 4 is a flowchart showing a control flow of select lateral acceleration calculation according to the first embodiment.
FIG. 5 is a flowchart showing calculation of a decompression determination value according to the first embodiment.
FIG. 6 is a time chart showing a control flow of stop lamp switch abnormality detection according to the first embodiment.
FIG. 7 is a time chart showing an operation example of the first embodiment.
FIG. 8 is a flowchart showing a tire abnormality detection control flow of a second embodiment.
[Explanation of symbols]
MCU main control unit
ENGCU engine control unit
ATCU AT control unit
ENG engine
AT automatic transmission
BU brake unit
W wheel
1 Wheel speed sensor
2 Steering angle sensor
3 Yaw rate sensor
4 Stop lamp switch

Claims (5)

Wheel speed detecting means for detecting the rotational speed of each wheel of the vehicle;
ON operation detection means for detecting the ON operation state of the stop lamp;
First comparing means for detecting that the wheel speed exceeds a first threshold;
Second comparing means for detecting that the wheel speed has reached a second threshold value smaller than the first threshold value after exceeding the first threshold value;
While the stop lamp is still ON, it is determined whether or not the number measurement condition for detection by the second comparison unit after the detection by the first comparison unit is satisfied, and the number measurement condition Stop lamp switch abnormality determining means for determining that the stop lamp switch is abnormal when the establishment of is continued a predetermined number of times,
A stop lamp switch abnormality detection device comprising: In the stop lamp switch abnormality detection device according to claim 1,
The stop lamp switch abnormality detection device, wherein the second threshold value is 0 km / h. In the stop lamp switch abnormality detection device according to claim 1 or 2,
A stop lamp switch abnormality detecting device, comprising: a notification means for notifying a driver when the stop lamp switch abnormality determining means determines that an abnormality has occurred. In the tire abnormality detection device provided with tire abnormality detection means for executing tire abnormality detection control for comparing the wheel speed of each wheel and detecting that the tire air pressure is reduced under a predetermined condition,
Wheel speed detection means for detecting the rotational speed of each wheel of the vehicle, ON operation detection means for detecting the ON operation state of the stop lamp, and first comparison means for detecting that the wheel speed exceeds the first threshold value And second comparison means for detecting that the wheel speed has reached a second threshold value smaller than the first threshold value after exceeding the first threshold value, and the stop lamp is still ON. In this state, after the detection by the first comparison means, it is determined whether or not the number measurement condition for detection by the second comparison means is satisfied, and the number measurement condition is continuously satisfied for a predetermined number of times. A stop lamp switch abnormality detecting device, which is provided with a stop lamp switch abnormality determining means for determining that the stop lamp switch is abnormal.
A tire abnormality detection device, comprising: a prohibition determination means for prohibiting a determination of a decrease in air pressure in the tire abnormality detection means when the stop lamp switch abnormality determination means determines that the stop lamp switch is abnormal. Tire abnormality detection means for performing tire abnormality detection control for comparing the wheel speed of each wheel and detecting that the tire air pressure has decreased under a predetermined condition, and the vehicle deceleration exceeds a deceleration threshold In the tire abnormality detection device provided with prohibition determination means for prohibiting the air pressure decrease determination by the tire abnormality detection means,
Wheel speed detection means for detecting the rotational speed of each wheel of the vehicle, ON operation detection means for detecting the ON operation state of the stop lamp, and first comparison means for detecting that the wheel speed exceeds the first threshold value And second comparison means for detecting that the wheel speed has reached a second threshold value smaller than the first threshold value after exceeding the first threshold value, and the stop lamp is still ON. In this state, after the detection by the first comparison means, it is determined whether or not the number measurement condition for detection by the second comparison means is satisfied, and the number measurement condition is continuously satisfied for a predetermined number of times. A stop lamp switch abnormality detecting device, which is provided with a stop lamp switch abnormality determining means for determining that the stop lamp switch is abnormal.
When the stop lamp switch abnormality determining means determines that the stop lamp switch is abnormal, the tire abnormality is characterized in that the deceleration threshold value in the prohibition determining means is shifted to a side that increases the sensitivity of the prohibition determination. Detection device.

Images