JP5394347B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device capable of diagnosing a failure of a reverse switch that detects that a transmission gear is in a reverse position.

  2. Description of the Related Art Conventionally, as a vehicle control device, a device that determines a reverse switch failure by comparing a signal from a wheel speed sensor that can determine whether the vehicle is moving forward or backward and a signal from a reverse switch is known (patent) Reference 1). Specifically, this vehicle control device, for example, when the signal from the wheel speed sensor indicates the forward movement of the vehicle but the ON signal (the signal indicating the backward movement) is output from the reverse switch, It is determined that the reverse switch is faulty.

JP 2004-325448 A

  By the way, some of the wheel speed sensors output the same signal when the vehicle moves forward / backward, that is, for example, the rotational speed of the wheel is purely detected by waveforms output from, for example, a magnetic sensor and a magnetic encoder. There are only those that cannot distinguish forward / backward. When such a wheel speed sensor is used, it is impossible to use the determination method as in the prior art, and it is not possible to determine the reverse switch failure.

  Therefore, an object of the present invention is to provide a vehicle control device that can perform failure determination of a reverse switch (reverse detection means) using a wheel speed sensor that cannot determine forward / reverse of the vehicle.

The present invention that solves the above-described problems includes a first traveling direction determination unit that determines a traveling direction of a vehicle based on a reverse signal output from a reverse detection unit that detects that the gear position of the transmission is a reverse position; Second traveling direction determination means for determining a traveling direction of the vehicle based on a signal different from the reverse signal, a traveling direction of the vehicle determined by the first traveling direction determination means, and a determination by the second traveling direction determination means And a diagnostic unit that determines whether or not the reverse detection unit is normal depending on whether or not the traveling direction of the vehicle coincides with the traveling direction of the vehicle, wherein the second traveling direction determination unit includes wheels A wheel speed calculation unit that calculates a wheel speed based on a signal output from a wheel speed sensor that detects only the rotation speed of the vehicle, a wheel acceleration calculation unit that calculates a wheel acceleration based on the wheel speed, and the wheel speed Anda longitudinal acceleration calculating unit for calculating a longitudinal acceleration of the acceleration applied in the longitudinal direction of the vehicle on the basis of the different information, compares the value correlated with the longitudinal acceleration, and a value correlated to the wheel acceleration, Addition processing for adding a timer when the value correlated with the longitudinal acceleration and the value correlated with the wheel acceleration are both larger than the first plus threshold or both are smaller than the first minus threshold And a value correlated with the longitudinal acceleration is larger than the first plus threshold and a value correlated with the wheel acceleration is smaller than the first minus threshold, or correlated with the longitudinal acceleration. A subtraction process for subtracting a timer when a value to be performed is smaller than the first negative threshold value and a value correlated with the wheel acceleration is larger than the first positive threshold value Run the vehicle when the timer exceeds a first predetermined time and wherein the determining and moving forward.

  Here, the “rotation speed” means the rotation speed (rotation speed) of the wheel per unit time.

According to the present invention, the longitudinal acceleration calculated based on the information different from the wheel speed is used for the value correlated with the wheel acceleration based on the wheel speed acquired from the wheel speed sensor that cannot determine whether the vehicle is moving forward or backward. Correlated values have different signs depending on the forward / backward movement of the vehicle. Therefore, even when using a relatively inexpensive wheel speed sensor that cannot discriminate between forward / reverse of the vehicle, a simple system can be used by comparing the value correlated with the longitudinal acceleration with the value correlated with the wheel acceleration. The traveling direction of the vehicle can be determined in the same manner as the wheel speed sensor that can determine whether the vehicle is moving forward or backward while being configured. Further, when the vehicle moves forward, it is possible to make a forward determination by effectively using a phenomenon in which a value correlated with longitudinal acceleration and a value correlated with wheel acceleration are output to the same sign side (for example, plus side). .

Further, the present invention provides a first traveling direction determination unit that determines a traveling direction of a vehicle based on a reverse signal output from a reverse detection unit that detects that the gear position of the transmission is a reverse position, and the reverse signal. Second traveling direction determining means for determining the traveling direction of the vehicle based on a signal different from the above, the traveling direction of the vehicle determined by the first traveling direction determining means, and the vehicle traveling direction determined by the second traveling direction determining means And a diagnostic unit that determines whether or not the reverse detection unit is normal depending on whether or not the traveling direction coincides with the traveling direction, wherein the second traveling direction determination unit includes the number of rotations of a wheel. A wheel speed calculation unit that calculates a wheel speed based on a signal output from a wheel speed sensor that detects only the wheel speed, a wheel acceleration calculation unit that calculates a wheel acceleration based on the wheel speed, and information different from the wheel speed Based anda longitudinal acceleration calculating unit for calculating a longitudinal acceleration of the acceleration applied in the longitudinal direction of the vehicle, a value correlated with the longitudinal acceleration is compared with the value correlated with the wheel acceleration, the longitudinal acceleration When the value correlated with the wheel acceleration is larger than the second positive threshold and the value correlated with the wheel acceleration is smaller than the second negative threshold, or when the value correlated with the longitudinal acceleration is the second When the value smaller than the minus threshold and correlated with the wheel acceleration is larger than the second plus threshold, an addition process is performed to add a timer, and the value correlated with the longitudinal acceleration and the wheel acceleration are correlated. When the values to be subtracted are both larger than the second positive threshold or both are smaller than the second negative threshold, Timer, wherein the determining that the vehicle is retracted when exceeds a second predetermined time.

According to the present invention , at the time of reverse of the vehicle, the value that correlates with the longitudinal acceleration and the value that correlates with the wheel acceleration are effectively utilized on the different sign sides (plus side and minus side), A reverse determination can be made. In particular, by combining this reverse determination with the above-described forward determination (determination using the fact that the value correlated with the longitudinal acceleration and the value correlated with the wheel acceleration are output to the same sign side), the traveling direction of the vehicle is determined. More accurate determination can be made.

  In the present invention, it is preferable that a value correlated with the longitudinal acceleration is a differential value of the longitudinal acceleration, and a value correlated with the wheel acceleration is a differential value of the wheel acceleration.

  According to this, it is possible to accurately determine the forward / backward movement by using the differential value of each acceleration without being influenced by the road surface gradient.

  In the present invention, it is desirable that the wheel speed calculation unit is configured to calculate a wheel speed based on a signal output from a wheel speed sensor provided on the driven wheel.

  According to this, the wheel acceleration (for example, the differential value) can be calculated from the wheel speed of the driven wheel which is not affected by the driving force of the vehicle and is less likely to slip with the road surface. Can be determined.

Further, the present invention provides a first traveling direction determination unit that determines a traveling direction of a vehicle based on a reverse signal output from a reverse detection unit that detects that the gear position of the transmission is a reverse position, and the reverse signal. Second traveling direction determining means for determining the traveling direction of the vehicle based on a signal different from the above, the traveling direction of the vehicle determined by the first traveling direction determining means, and the vehicle traveling direction determined by the second traveling direction determining means And a diagnostic unit that determines whether or not the reverse detection unit is normal depending on whether or not the traveling direction coincides with the traveling direction, wherein the second traveling direction determination unit includes the number of rotations of a wheel. A wheel speed calculation unit that calculates a wheel speed based on a signal output from a wheel speed sensor that detects only the wheel speed, a wheel acceleration calculation unit that calculates a wheel acceleration based on the wheel speed, and information different from the wheel speed A longitudinal acceleration calculation unit that calculates an acceleration in the longitudinal direction of the vehicle as a longitudinal acceleration based on the vehicle, and compares the value correlated with the longitudinal acceleration with the value correlated with the wheel acceleration, A direction is determined, and the diagnostic means calculates a downhill running history indicating that the vehicle has descended when the vehicle travels down a slope with natural acceleration using gravity , and after the vehicle has traveled When the vehicle stops, a history calculation unit that clears the downhill traveling history up to that time, and whether or not there is the downhill traveling history while the vehicle is traveling and stopped, are always determined, and it is determined that there is no downhill traveling history It is allowed to determine whether or not the reverse detection means is normal when it is, and when it is determined that there is a downhill running history, it is determined whether or not the reverse detection means is normal having, and the diagnosis permission unit that prohibits And wherein the door.

According to the present invention , when there is a downhill traveling history indicating that the vehicle has traveled down the slope, there is a possibility of traveling (natural acceleration due to gravity) that does not depend on the driving force of the vehicle. Therefore, in such a case, the determination accuracy can be improved by prohibiting the failure determination of the reverse detection means.

  In the present invention, the history calculation unit includes a road surface gradient amount calculation unit that calculates a road surface gradient amount from a deviation between the longitudinal acceleration and the wheel acceleration, and whether the vehicle is descending regardless of the driving force. An addition value acquisition unit that acquires a predetermined road slope amount addition value according to each state of the vehicle in order to reflect whether or not the result of the downhill travel history is, the road slope amount The downhill travel history is calculated based on the road surface slope amount addition value, and the diagnosis permission unit is configured to calculate the downhill travel history when the downhill travel history is equal to or greater than a diagnosis permission threshold. It is desirable to determine that there is no downhill travel history when it is less than the diagnosis permission threshold.

  According to this, when it is determined that there is a downhill running history, there is a high possibility that the vehicle is descending without depending on the driving force, so the vehicle is descending regardless of the driving force. Therefore, it is possible to reliably prohibit the failure detection of the reverse detection means. Further, when it is determined that there is no downhill traveling history, there is a high possibility that the vehicle is traveling with the driving force, so that the failure determination can be performed well when the vehicle is traveling with the driving force. .

  In the present invention, the addition value acquisition unit includes a vehicle body speed acquisition unit that acquires a vehicle body speed, and an accelerator opening acquisition unit that acquires an accelerator opening, and the road surface gradient amount addition value is the accelerator. The current value of the downhill travel history exceeds the previous value of the downhill travel history when the opening degree is less than the first predetermined value or the vehicle body speed is less than the second predetermined value. It is desirable to set a value that does not exist.

  According to this, when at least one of the conditions that the accelerator opening is less than the first predetermined value or the vehicle body speed is less than the second predetermined value is satisfied, that is, the vehicle can travel without depending on the driving force. Since the current value of the downhill travel history does not become larger than the previous value (not close to the diagnosis permission threshold value) when the property is high, the failure determination at this time can be reliably prohibited by the diagnosis permission unit. That is, according to this, the road surface gradient amount addition value is appropriately set according to the conditions of the accelerator opening and the vehicle body speed, so that the vehicle can travel without depending on the driving force from the presence / absence of the accelerator operation or the vehicle body speed information. It is possible to classify in detail whether or not it is.

In the present invention, the second advancing direction determination unit is configured such that when both the value correlated with the longitudinal acceleration and the value correlated with the wheel acceleration are both greater than the first plus threshold, or both An addition process for adding a timer when the value is smaller than a negative threshold value of the first value, and a value correlated with the longitudinal acceleration is greater than the first positive threshold value and a value correlated with the wheel acceleration is the first value. A timer when the value is smaller than the negative threshold or when the value correlated with the longitudinal acceleration is smaller than the first negative threshold and the value correlated with the wheel acceleration is larger than the first positive threshold. When the timer exceeds a first predetermined time, it is determined that the vehicle is moving forward and exceeds a third predetermined time shorter than the first predetermined time. Determines that the vehicle is in a forward trend when the road surface gradient amount calculation unit, after the vehicle is determined to be a forward tendency than said filtering process performed before it is determined that the forward tendency It is preferable that the road surface gradient amount is calculated by performing a filtering process so that a fluctuation range between the previous value and the current value of the road surface gradient amount is increased.

  According to this, when it is not determined that the vehicle is moving forward, that is, when it is uncertain whether or not the vehicle is moving forward, the fluctuation range between the current value and the previous value of the road surface gradient amount is determined by strict filtering. Since it is made smaller, it is possible to prevent the downhill traveling history from easily falling below the diagnosis permission threshold due to temporary vehicle behavior. Also, when the vehicle is determined to be moving forward, the fluctuation range between the current value and the previous value of the road surface gradient amount is increased by a loose filter process, so the downhill running history can be quickly converted to the actual road surface gradient amount. Can be followed.

In the present invention, the second advancing direction determination means may be configured such that a value correlated with the longitudinal acceleration is greater than the second plus threshold and a value correlated with the wheel acceleration is greater than the second minus threshold. Or when the value correlated with the longitudinal acceleration is smaller than the second minus threshold and the value correlated with the wheel acceleration is larger than the second plus threshold. A timer is executed when the value correlated with the longitudinal acceleration and the value correlated with the wheel acceleration are both greater than the second plus threshold or both are less than the second minus threshold. When the timer exceeds a second predetermined time, it is determined that the vehicle is moving backward, and a fourth predetermined time shorter than the second predetermined time is exceeded. Determines that the vehicle is in the retracted trend when the road surface gradient amount calculation unit, after the vehicle is determined to be a backward tendency than said filtering performed before is determined to be backward trend It is desirable that the road surface gradient amount is calculated by performing a filtering process that increases the fluctuation range between the previous value and the current value of the road surface gradient amount.

  According to this, when it is not determined that the vehicle is in a backward tendency, that is, when it is uncertain whether the vehicle is in a backward tendency or not, the fluctuation range between the current value and the previous value of the road surface gradient amount by strict filter processing. Therefore, it is possible to prevent the downhill traveling history from easily falling below the diagnosis permission threshold due to temporary vehicle behavior. In addition, when it is determined that the vehicle is moving backward, the fluctuation range between the current value and the previous value of the road slope amount is increased by a loose filter process, so that the downhill running history can be quickly converted to the actual road slope amount. Can be followed.

  According to the present invention, even when a wheel speed sensor that cannot determine forward / reverse of the vehicle is used, the traveling direction of the vehicle can be determined from information different from the reverse signal from the reverse detection means. Can be determined.

It is a block diagram which shows the vehicle provided with the control apparatus for vehicles. It is a block diagram which shows the structure of a control part. It is a time chart which shows the differential value etc. of each acceleration when a vehicle advances. It is a time chart which shows the differential value etc. of each acceleration when a vehicle reverses. It is a flowchart which shows a forward determination process. It is a flowchart which shows reverse determination processing. It is a map which shows the road surface gradient amount addition value set so as to correspond to each vehicle body speed and each accelerator opening. It is the figure (a) which shows the state in which the vehicle stopped by the up grade naturally accelerates in a neutral state, and the time chart (b) which shows the relationship between the amount of road surface gradients, and a downhill running history. It is a flowchart which shows failure determination. It is a flowchart which shows the determination of the presence or absence of a downhill running history.

Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
As shown in FIG. 1, the vehicle control device 100 is for appropriately controlling a braking force (brake hydraulic pressure) applied to each wheel W of the vehicle CR, and mainly includes an oil passage (hydraulic pressure passage). And a hydraulic unit 10 provided with various components, and a control unit 20 for appropriately controlling the various components in the hydraulic unit 10.

  The hydraulic unit 10 is a unit including a known inlet valve, outlet valve, reservoir, pump, and the like, and is configured to be able to reduce, hold, and increase the hydraulic pressure in each wheel cylinder H. .

  The wheel cylinder H is a hydraulic device that converts the brake hydraulic pressure generated by the master cylinder MC and the vehicle control device 100 into the operating force of the wheel brakes FR, FL, RR, RL provided on each wheel W. Each is connected to the hydraulic unit 10 of the vehicle control device 100 via a pipe.

  The control unit 20 includes, for example, a CPU, a RAM, a ROM, and an input / output circuit, and inputs from a wheel speed sensor 91, a reverse switch 92 as an example of a reverse detection means, a longitudinal acceleration sensor 93, and an accelerator opening sensor 94. And control is performed by performing each arithmetic processing based on the program and data memorize | stored in ROM.

  The wheel speed sensor 91 is a sensor that detects only the rotation speed of the wheel W, that is, a sensor that cannot determine whether the vehicle CR is moving forward or backward, and is provided corresponding to each wheel W. Specifically, one wheel speed sensor 91 is provided for each of the two driving wheels W1 disposed on the front side of the vehicle CR, and one wheel speed sensor 91 is provided for each of the two rear driven wheels W2. . Each wheel speed sensor 91 outputs the detected wheel speed to the control unit 20.

  The reverse switch 92 is a sensor that detects that the gear position of the transmission (not shown) is the reverse position, and is provided in the transmission, for example, and directly detects the position of the reverse gear. When the reverse switch 92 detects that the gear position is the reverse position, the reverse switch 92 outputs a reverse signal indicating that to the control unit 20.

  The longitudinal acceleration sensor 93 is a sensor that detects acceleration applied in the longitudinal direction of the vehicle (specifically, acceleration-related information proportional to the acceleration), and is provided at an appropriate position of the vehicle CR. Then, the longitudinal acceleration sensor 93 outputs the detected acceleration related information to the control unit 20. The signal output from the longitudinal acceleration sensor 93 is a value having a direction in which acceleration is applied to the vehicle CR (a value with a positive / negative sign), and differs depending on whether the vehicle CR is moving forward or backward. Value.

  The accelerator opening sensor 94 is a sensor that detects the depression amount of the accelerator pedal AP, that is, the accelerator opening, and is provided in the vicinity of the accelerator pedal AP, for example. Then, the accelerator opening sensor 94 outputs the detected accelerator opening to the control unit 20.

Next, details of the control unit 20 will be described.
As shown in FIG. 2, the control unit 20 includes a first traveling direction determination unit 21, a vehicle body speed calculation unit 22, a stop determination unit 23, a second traveling direction determination unit 24, and a diagnosis unit 25. Yes.

  The first traveling direction determination means 21 has a function of determining the traveling direction of the vehicle based on the reverse signal output from the reverse switch 92. Specifically, the first advancing direction determination means 21 determines that the advancing direction of the vehicle is backward when it receives a reverse signal from the reverse switch 92 when the vehicle starts and does not receive a reverse signal. Is determined to be forward. Then, the first traveling direction determination unit 21 outputs the traveling direction of the vehicle, which is the determination result, to the diagnosis unit 25.

  Note that whether or not the vehicle is starting is determined based on a stop flag from a stop determination unit 23 described later. That is, the first traveling direction determination unit 21 determines that the vehicle has started when the stop flag output from the stop determination unit 23 is switched from “1 (stop state)” to “0 (travel state)”. In this case, it is determined whether or not a backward signal is received. The first traveling direction determination means 21 determines that the vehicle has stopped when the stop flag is switched from “0” to “1”, and resets the determination result of the traveling direction.

  The vehicle body speed calculation means 22 has a function of calculating each wheel speed based on a signal output from each wheel speed sensor 91 and calculating a vehicle body speed based on each calculated wheel speed. The vehicle body speed calculating unit 22 outputs the calculated wheel speed and vehicle body speed to the stop determination unit 23, and outputs the vehicle body speed to the diagnosis unit 25 (specifically, a vehicle body speed acquisition unit A22 described later).

  The stop determination unit 23 has a function of determining whether or not the vehicle has stopped based on the wheel speed and the vehicle body speed output from the vehicle body speed calculation unit 22. In addition, since this determination method should just employ | adopt a well-known method, the description is abbreviate | omitted.

  When the stop determination unit 23 determines that the vehicle has stopped, the stop flag is set to “1”, and the stop flag “1” is set to the first travel direction determination unit 21 and the second travel direction determination unit 24. And it outputs to the diagnostic means 25 (detailed calculation part A3 mentioned later). If the stop determination means 23 determines that the vehicle is not stopped, the stop flag is set to “0”, and the stop flag “0” is set to the first travel direction determination means 21 and the second travel direction determination. It outputs to the means 24 and the diagnostic means 25.

  The second traveling direction determination means 24 has a function of determining the traveling direction of the vehicle based on a signal different from the reverse signal. Specifically, the second traveling direction determination unit 24 includes a wheel speed calculation unit 24a, a wheel acceleration calculation unit 24b, a longitudinal acceleration calculation unit 24c, an LPF processing unit 24d, and a determination unit 24e.

  The wheel speed calculation unit 24a has a function of calculating the wheel speed based on a signal output from a wheel speed sensor 91 provided on the driven wheel W2. Then, the wheel speed calculation unit 24a outputs the calculated wheel speed to the wheel acceleration calculation unit 24b.

  The wheel acceleration calculation unit 24b has a function of calculating the wheel acceleration by calculating the rate of change of the wheel speed output from the wheel speed calculation unit 24a. Then, the wheel acceleration calculation unit 24b outputs the calculated wheel acceleration to the LPF processing unit 24d.

  The longitudinal acceleration calculation unit 24c has a function of calculating the acceleration applied in the longitudinal direction of the vehicle as the longitudinal acceleration based on information different from the wheel speed calculated by the wheel speed calculation unit 24a. Specifically, the longitudinal acceleration calculator 24 c calculates the longitudinal acceleration based on the acceleration related information output from the longitudinal acceleration sensor 93. In this embodiment, the longitudinal acceleration is output to the plus side when the vehicle accelerates in the forward direction, and the longitudinal acceleration is output to the minus side when the vehicle accelerates in the backward direction. However, the longitudinal acceleration may be output to the minus side when the vehicle accelerates in the forward direction, and the longitudinal acceleration may be output to the plus side when the vehicle accelerates in the backward direction. Then, the longitudinal acceleration calculation unit 24c outputs the calculated longitudinal acceleration to the LPF processing unit 24d.

  The LPF processing unit 24d is a low-pass filter that performs filter processing such as removing noise (high frequency) of the input signal. Then, the LPF processing unit 24d filters the wheel acceleration output from the wheel acceleration calculation unit 24b and the longitudinal acceleration output from the longitudinal acceleration calculation unit 24c, and then outputs them to the determination unit 24e.

  The determination unit 24e differentiates both the wheel acceleration and the longitudinal acceleration output from the LPF processing unit 24d, and then compares each differential value (a value correlated with the wheel acceleration and a value correlated with the longitudinal acceleration) Has a function of determining the traveling direction. Here, as shown in FIG. 3, the differential value of the wheel acceleration and the differential value of the longitudinal acceleration are both output to the same sign side when the vehicle moves forward. On the other hand, as shown in FIG. 4, when the vehicle moves backward, the differential value of the wheel acceleration and the differential value of the longitudinal acceleration are output so as to have opposite signs. And the determination part 24e determines the advancing direction of a vehicle using such a difference in the output of each differential value.

  Specifically, the determination unit 24e always performs the forward determination process illustrated in FIG. 5 and the reverse determination process illustrated in FIG.

  In the forward determination process shown in FIG. 5, the determination unit 24e first determines whether or not the vehicle is stopped based on the stop flag output from the stop determination means 23 (S1). If it is determined in step S1 that the vehicle is not stopped (No), the determination unit 24e determines that the absolute value of the differential value GF of the longitudinal acceleration and the absolute value of the differential value GT of the wheel acceleration are both the first threshold value α. It is determined whether it is larger (S2).

  If it is determined in step S2 that both absolute values are both greater than the first threshold value α (Yes), the determination unit 24e determines the sign (positive / negative) of the differential value GF of the longitudinal acceleration and the differential value GT of the wheel acceleration. It is determined whether the signs are the same (S3). If it is determined in step S3 that the differential values GF and GT have the same sign (Yes), the determination unit 24e performs forward timer addition processing such as adding a forward timer (hereinafter referred to as forward timer). Execute (S4).

  In other words, the determination unit 24e performs the process of step S2 (Yes) → step S3 (Yes) → step S4, so that the differential value GF of the longitudinal acceleration and the differential value GT of the wheel acceleration as shown by the solid line in FIG. Are both greater than the first positive threshold value α (for example, between times t1 and t2), or both are smaller than the first negative threshold value −α (for example, between times t3 and t4). Addition processing is executed.

  If it is determined in step S3 that the differential values GF and GT are different signs (No), the determination unit 24e performs forward timer subtraction processing such as subtracting the forward timer (S5).

  That is, the determination unit 24e performs the process of step S2 (Yes) → step S3 (No) → step S5, so that the differential value GF of the longitudinal acceleration becomes the first negative threshold as shown by the broken line in FIG. When the wheel acceleration differential value GT is smaller than −α and larger than the first positive threshold value α (for example, between time t9 and t10), or the longitudinal acceleration differential value GF is higher than the first positive threshold value α. And the differential value GT of the wheel acceleration is smaller than the first minus threshold value −α (for example, after time t11), the forward timer subtraction process is executed.

  After step S4, S5, or when it is determined No in step S2, the determination unit 24e determines that the forward timer (measured time) that is increased by the forward timer addition process (S4) is the first predetermined time T1. Is determined (S6). If it is determined in step S6 that the forward timer has reached the first predetermined time T1 (Yes), the determination unit 24e determines that the vehicle is moving forward, and sets a forward flag indicating that to “1”. (S7).

  In step S6, when the advance timer is less than the first predetermined time T1 (No), the determination unit 24e determines that the advance timer is a third predetermined time T3 (a time shorter than the first predetermined time T1). It is determined whether or not the above is true (S8). In step S8, when it is determined that the forward timer is equal to or longer than the third predetermined time T3 (Yes), the determination unit 24e determines that the vehicle is highly likely to move forward, and indicates the advance. The tendency flag is set to “1” (S9).

  When it is determined in step S8 that the advance timer is less than the third predetermined time T3 (No), the determination unit 24e sets the advance tendency flag to “0” (S15).

  After steps S7, S9, and S15, the determination unit 24e determines whether or not the forward flag is “1” (S10). In step S10, when the advance flag is “1” (Yes), the determination unit 24e determines whether or not the advance timer is equal to or less than the advance cancellation time T5 (T3 <T5 <T1) (S11). .

  If it is determined in step S11 that the advance timer is equal to or less than the advance cancellation time T5 (Yes), the determination unit 24e performs a process of returning the advance flag to 0 (S12).

  If it is determined in step S1 that the vehicle has stopped, the determination unit 24e clears the forward timer (S13), and then returns both the forward flag and the forward tendency flag to “0” (S14).

  In the reverse determination process shown in FIG. 6, the determination unit 24e executes a process in which the addition process (S4) and the subtraction process (S5) in the forward determination process described above are interchanged. Specifically, the determination unit 24e performs steps S101 to S115 that are substantially the same as steps S1 to S15 of the forward determination process, and performs steps S104 and S105 corresponding to steps S4 and S5 of the forward determination process. The conditions for entering are opposite to the conditions for the forward determination process.

  Here, in the reverse determination process, the forward parameters (forward timer, forward flag and forward tendency flag) in the forward determination process are changed to backward parameters (reverse timer, reverse flag and reverse tendency flag). Yes. In steps S102, S106, S108, and S111, each threshold value in the backward determination process is a symbol different from that in the forward determination process in order to distinguish it from each threshold value (α, T1, T3, T5) in the forward determination process. Although expressed as β, T2, T4, and T6, α and β, T1 and T2, T3 and T4, and T5 and T6 may be different values or the same value.

  In the reverse determination process, the determination unit 24e first performs steps S101 to S103 that are substantially the same as those in the forward determination process. If the signs are the same in step S103 (Yes), the determination unit 24e performs reverse timer subtraction processing (S105) for subtracting the reverse timer, contrary to the forward determination processing, and the signs are different. (No), a backward timer addition process (S104) for adding a backward timer is performed.

  That is, the determination unit 24e performs the process of step S102 (Yes) → step S103 (No) → step S104, so that the differential value GF of the longitudinal acceleration becomes the second negative threshold as shown by the solid line in FIG. When the wheel acceleration differential value GT is smaller than −β and larger than the second positive threshold value β (for example, between time t21 and t22), or the longitudinal acceleration differential value GF is larger than the second positive threshold value β. And the differential value GT of the wheel acceleration is smaller than the second minus threshold −β (for example, between time t23 and t24), the reverse timer addition process is executed.

  Moreover, the determination part 24e performs the process of step S102 (Yes)-> step S103 (Yes)-> step S105, and as shown with the broken line in FIG. 4, the longitudinal acceleration differential value GF and the wheel acceleration differential value GT are shown. Are both larger than the second positive threshold value β (for example, between time t29 and t30), or both are smaller than the second negative threshold value −β (for example, after time t31), the backward timer subtraction process. Execute.

  And after step S104, S105, or when it determines with No by step S102, the determination part 24e is the 2nd predetermined | prescribed timer (measurement time) which increases by the reverse timer addition process (S104). It is determined whether or not the time T2 has been reached (S106). If it is determined in step S106 that the reverse timer has reached the second predetermined time T2 (Yes), the determination unit 24e determines that the vehicle is moving backward, and sets a reverse flag indicating that to “1”. (S107).

  In step S106, if the reverse timer is less than the second predetermined time T2 (No), the determination unit 24e determines that the reverse timer is the fourth predetermined time T4 (a time shorter than the second predetermined time T2). It is determined whether or not this is the case (S108). In step S108, when it is determined that the reverse timer is equal to or longer than the fourth predetermined time T4 (Yes), the determination unit 24e determines that the vehicle is highly likely to move backward, and indicates that the vehicle is moving backward. The tendency flag is set to “1” (S109).

  If it is determined in step S108 that the reverse timer is less than the fourth predetermined time T4 (No), the determination unit 24e sets the reverse tendency flag to “0” (S115).

  After steps S107, S109, and S115, the determination unit 24e determines whether or not the reverse flag is “1” (S110). If the reverse flag is “1” in step S110 (Yes), the determination unit 24e determines whether or not the reverse timer is equal to or less than the reverse release time T6 (T4 <T6 <T2) (S111). .

  If it is determined in step S111 that the reverse timer is equal to or less than the reverse release time T6 (Yes), the determination unit 24e performs a process of returning the reverse flag to 0 (S112).

  If YES is determined in step S101, the determination unit 24e clears the reverse timer (S113), and then returns both the reverse flag and the reverse tendency flag to “0” (S114).

  According to the determination unit 24e configured as described above, for example, when the vehicle moves forward from a stopped state as illustrated in FIG. 3 (when the waveforms of the differential values GF and GT are waveforms at the time of forward movement). When the differential values GF and GT exceed both the threshold values α and −α, the advance timer is added. When the differential values GF and GT are within the ranges of the threshold values α and −α, the value of the advance timer is held.

  When the forward timer becomes equal to or longer than the third predetermined time T3 (time t2), the forward tendency flag becomes “1”, and then when the forward timer reaches the first predetermined time T1 (time t8), the forward flag becomes “1”. Therefore, when the output waveform is as shown in FIG. 3, it is possible to determine that the traveling direction of the vehicle is forward.

  After the forward flag becomes “1”, for example, when the differential value GF of the longitudinal acceleration changes as indicated by a broken line, the differential value GF of the longitudinal acceleration is smaller than the first minus threshold −α. And when the differential value GT of the wheel acceleration becomes larger than the first plus-side threshold value α (time t9), the forward timer is subtracted. Thereafter, when the forward timer to be subtracted becomes the forward cancellation time T5 or less (time t10), the forward flag becomes “0”. When the forward timer further subtracted becomes less than the third predetermined time T3 (time t12), the forward tendency flag becomes “0”. Each flag is also set to “0” when it is determined that the vehicle has stopped. In this case, the forward timer is further cleared.

  On the other hand, in the reverse determination process, if the output waveform is a waveform like the solid line in FIG. 3, the reverse timer addition process (S105) is not performed, so the reverse timer and the reverse flag are not increased without increasing the reverse timer. It will never be “1”. In addition, as shown in FIG. 4, when the vehicle moves backward from the stopped state (when the waveforms of the differential values GF and GT are waveforms at the time of backward movement), a waveform opposite to that at the time of forward movement is obtained. In the reverse determination process, the reverse tendency flag and the reverse flag are both “1”. On the other hand, in the forward determination process, the forward tendency flag and the forward flag do not become “1”.

  Then, as shown in FIG. 2, the determination unit 24e diagnoses the forward tendency flag, the backward tendency flag, the forward flag, and the backward flag that are “1” or “0”, and the filtered longitudinal acceleration and wheel acceleration. To 25. Note that because the output waveform of the differential value of longitudinal acceleration differs between forward and backward, the forward tendency flag and the backward tendency flag do not become the same value, and the forward flag and the reverse flag have the same value. Never become.

  The diagnosis unit 25 determines whether the reverse switch 92 is normal depending on whether or not the vehicle traveling direction determined by the first traveling direction determination unit 21 matches the vehicle traveling direction determined by the second traveling direction determination unit 24. It has a function of determining whether or not (hereinafter also referred to as “failure determination”). Specifically, the diagnosis unit 25 includes a history calculation unit 25a, a diagnosis permission unit 25b, and a diagnosis unit 25c.

  The history calculation unit 25a calculates a downhill traveling history indicating that the vehicle has descended when the vehicle travels down the slope, and clears the downhill traveling history up to that time when the vehicle stops after traveling. It has a function to do. Here, “the vehicle travels in the direction of going down the slope” means that the vehicle goes forward and goes down the slope, and also means that the vehicle goes backward and goes down the slope.

  The history calculation unit 25a includes a road surface gradient amount calculation unit A1, an addition value acquisition unit A2, and a calculation unit A3.

  The road surface gradient amount calculation unit A1 has a function of calculating the road surface gradient amount based on the longitudinal acceleration, the wheel acceleration, the forward tendency flag, and the backward tendency flag output from the second traveling direction determination unit 24. Specifically, when the forward tendency flag is “1”, the road surface gradient amount calculation unit A1 calculates the road surface gradient amount by the following equation (1) using the deviation between the longitudinal acceleration and the wheel acceleration.

Road surface gradient amount (n) = road surface gradient amount (n-1) + filter coefficient 1 x {(longitudinal acceleration-wheel acceleration)-road surface gradient amount (n-1)} (1)
Road surface gradient amount (n): Current value of road surface gradient amount Road surface gradient amount (n-1): Previous value of road surface gradient amount Positive number smaller than filter coefficient 1: 1

When the reverse tendency flag is “1”, the road surface gradient amount calculation unit A1 calculates the road surface gradient amount by the following equation (2) in which the sign of the longitudinal acceleration in the equation (1) is minus. Is calculated.
Road surface gradient amount (n) = Road surface gradient amount (n-1) + Filter coefficient 1 x {(-Longitudinal acceleration-Wheel acceleration)-Road surface gradient amount (n-1)} (2)

Further, when both the forward tendency flag and the backward tendency flag are “0”, the road slope amount calculation unit A1 uses the deviation between the longitudinal acceleration and the wheel acceleration to calculate the road slope amount by the following equation (3). Is calculated.
Road surface gradient amount (n) = Road surface gradient amount (n−1) + Filter coefficient 2 × {(longitudinal acceleration−wheel acceleration) −road surface gradient amount (n−1)} (3)
Filter coefficient 2: positive number smaller than filter coefficient 1

  That is, after the road surface gradient amount calculation unit A1 determines that the vehicle has a forward tendency (when the forward tendency flag is “1”), the road surface gradient amount calculation unit A1 sets the forward slope flag to “0”. The road surface gradient amount is calculated by performing a gentle filter process so that the fluctuation range between the previous value and the current value of the road surface gradient amount becomes larger than that of the case of “”.

  Further, the road surface gradient amount calculation unit A1 determines that the vehicle is in a reverse tendency (when the reverse tendency flag is “1”) and before it is determined that the vehicle is in a reverse tendency (the reverse tendency flag is “0”). The road surface gradient amount is calculated by performing a gentle filter process so that the fluctuation range between the previous value and the current value of the road surface gradient amount becomes larger than that in the case of (1).

  According to this, when it is uncertain whether the vehicle is moving forward or backward, the fluctuation range between the current value and the previous value of the road surface gradient amount is reduced by a strict filter coefficient 1, so that it is easy to change depending on temporary vehicle behavior. In addition, it is possible to prevent the downhill running history from falling below a diagnosis permission threshold described later. In addition, when the vehicle is determined to move forward or backward, the fluctuation range between the current value and the previous value of the road slope amount is increased by the loose filter coefficient 2, so that the downhill traveling history can be quickly converted into the actual road slope amount. It is possible to follow.

  Then, the road surface gradient amount calculation unit A1 outputs the calculated road surface gradient amount to the calculation unit A3.

  In order to reflect whether the vehicle is going downhill regardless of driving force (driving force by an engine, a motor, etc.) in the result of the downhill running history, the addition value acquisition unit A2 Accordingly, it has a function of acquiring a predetermined road surface slope amount addition value. Specifically, the addition value acquisition unit A2 includes an accelerator opening acquisition unit A21 that acquires the accelerator opening from the accelerator opening sensor 94, and a vehicle body speed acquisition unit A22 that acquires the vehicle body speed from the vehicle body speed calculation means 22. doing.

  And this addition value acquisition part A2 adds road surface gradient amount based on the accelerator opening acquired by accelerator opening acquisition part A21, the vehicle body speed acquired by vehicle body speed acquisition part A22, and the map shown in FIG. The value is to be acquired. The map is stored in a storage unit (not shown), and road surface slope amount addition values corresponding to the vehicle body speeds and the accelerator opening are set.

Specifically, when the accelerator opening θ is less than the first predetermined value θ1, the road surface slope amount addition value is all 0 m / s ² regardless of the vehicle body speed (the current value of the downhill travel history is the value of the downhill travel history). A value that does not exceed the previous value, that is, a value that selects the smaller one of the previous value of the downhill travel history or the current value of the road surface gradient amount). This is because when the accelerator opening θ is less than the first predetermined value θ1, that is, when the accelerator pedal is OFF, there is a high possibility that traveling by natural acceleration using gravity is performed on the slope, This is because it is necessary to leave a downhill traveling history in order to prohibit failure determination described later.

When the vehicle body speed V is less than the second predetermined value V1, the road surface gradient amount addition value is all 0 m / s ² regardless of the accelerator opening (the current value of the downhill travel history is the previous value of the downhill travel history. Is set to a value that does not exceed the value, that is, the smaller value of the previous value of the downhill running history or the current value of the road surface gradient amount is selected). This assumes the case where the accelerator is turned on by switching to the forward gear before it is determined that the vehicle has stopped after the vehicle has retreated on the slope in the neutral state due to natural acceleration using gravity. Even in this case, a downhill traveling history is left so as to prohibit failure determination described later.

If the vehicle speed is medium (V1 km / h ≦ V <V2 km / h) or high speed (V ≧ V2 km / h), it is considered that the possibility of traveling by natural acceleration is low, and the vehicle travels downhill. Road surface gradient amount addition values are set to values (VAm / s ² , VBm / s ² ) such that no history remains. It should be noted that at medium speed, there is a possibility of natural acceleration, so the value is set smaller than that at high speed. Thereby, in the calculation process of the downhill traveling history, the downhill traveling history gradually approaches a diagnosis permission threshold described later at the middle speed than at the high speed.

  Here, the magnitude relationship between the values V1, V2, VA, and VB is V1 <V2 and VA <VB.

  Then, as illustrated in FIG. 2, the addition value acquisition unit A2 outputs the acquired road surface gradient amount addition value to the calculation unit A3.

  The calculation unit A3 includes a stop flag output from the stop determination unit 23, a road surface gradient amount output from the road surface gradient amount calculation unit A1, and a road surface gradient amount addition value output from the addition value acquisition unit A2. The downhill running history is calculated based on the above. Specifically, when the stop flag is “1 (stop state)”, the calculation unit A3 calculates the downhill travel history based on the following formula (4) and the road surface gradient amount, and stops the vehicle. When the flag is “0 (traveling state)”, the downhill traveling history is calculated based on the following equation (5), the road surface gradient amount, and the road surface gradient amount addition value.

<When stopped>
Downhill running history (n) = MIN {0, road slope amount (n)} (4)
Downhill travel history (n): Current value of downhill travel history Road surface slope amount (n): Current value of road surface slope amount

<When driving>
Downhill travel history (n) = MIN {0, road slope amount (n), downhill travel history (n−1) + MIN [additional value of road slope amount, road slope amount (n) −downhill travel history (n− 1)]} (5)
Downhill travel history (n-1): Previous value of downhill travel history

  That is, in Equation (4), the smaller value of 0 and the road surface gradient amount (n) is selected as the downhill travel history (n). Further, in the equation (5), 0, road slope amount (n) and “downhill running history (n−1) + MIN [road slope amount addition value, road slope amount (n) −downhill running history (n−1) ) ”Is selected as the downhill running history (n).

  Specifically, for example, as shown in FIG. 8 (a), the calculation unit A3, when the vehicle CR goes down due to natural acceleration by releasing the brake in the neutral state from the state where the vehicle CR has stopped on the ascending slope, As shown, the downhill running history is calculated. That is, when the vehicle CR is stopped at an uphill gradient, the road surface gradient amount is held at a positive value by calculating the road surface gradient amount based on the longitudinal acceleration by the above-described equation (3). At this time, 0, which is a value smaller than the positive road surface gradient amount, is selected from the equation (4) as the downhill traveling history.

  After that, when the brake is released in the neutral state, the vehicle CR goes down the ascending slope. At this time, if the reverse tendency flag becomes “1”, the road surface slope amount is calculated by the above-described equation (2). Thus, the road surface gradient amount gradually approaches 0 and changes toward the minus side. The downhill running history is maintained as 0 when the road surface gradient amount is larger than 0 according to the equation (5), and follows the road surface gradient amount when the road surface gradient amount becomes negative.

Further, when the vehicle CR travels on a flat ground after descending an ascending slope, the road surface slope amount gradually rises from the minus side to approach zero. At this time, if the value at the time of low speed (0 m / s ² ) is selected as the road surface slope amount addition value, the previous value (road surface slope) of the downhill travel history is shown as indicated by the solid line. Held at the minimum amount).

When the accelerator ON / medium speed value (VAm / s ² ) is selected as the road surface gradient addition value, the downhill running history gradually approaches 0 as shown by the broken line. . In addition, when accelerator ON / high speed (VBm / s ² ) is selected as the road surface gradient amount addition value, the downhill running history quickly approaches 0 following the road surface gradient amount.

  Then, as illustrated in FIG. 2, the calculation unit A3 outputs the calculated downhill travel history to the diagnosis permission unit 25b.

  The diagnosis permission unit 25b always determines whether or not there is a downhill traveling history while the vehicle is traveling and stopped, and permits a failure determination of the reverse switch 92 when it is determined that there is no downhill traveling history. When it is determined that there is a downhill running history, it has a function of prohibiting failure determination. The diagnosis permission unit 25b determines that there is no downhill travel history when the downhill travel history is equal to or greater than the diagnosis permission threshold, and determines that there is a downhill travel history when the downhill travel history is less than the diagnosis permission threshold. It has become.

  Specifically, as shown in FIG. 8 (b), the diagnosis permission unit 25b indicates that the downhill traveling history output from the calculation unit A3 is less than the diagnosis permission threshold (separated from the diagnosis permission threshold with respect to zero). If it is a negative value), it is determined that there is a downhill traveling history, and failure determination is prohibited. As a result, as shown in FIG. 8 (a), when the vehicle is backed up due to natural acceleration in an ascending slope, it is possible to determine that there is a downhill running history and prohibit failure determination. Therefore, it is possible to prevent erroneous failure determination.

  Then, as shown in FIG. 2, the diagnosis permission unit 25b outputs a permission signal indicating the failure determination to the diagnosis unit 25c when the failure determination is permitted and prohibits the failure determination when the failure determination is prohibited. The signal is output to the diagnosis unit 25c.

  The diagnosis unit 25c is configured to perform a failure determination when receiving a permission signal from the diagnosis permission unit 25b, and to prohibit the failure determination when receiving a prohibition signal from the diagnosis permission unit 25b. In the diagnostic means 25 configured as described above, a failure determination as shown in FIG. 9 is performed. Since the diagnosis means 25 performs the process of determining the presence / absence of the downhill traveling history as described above before the failure determination shown in FIG. 9, first, FIG. The description will be given with reference.

  As shown in FIG. 10, the diagnosis unit 25 first determines whether or not the vehicle has a forward tendency, that is, whether or not the forward tendency flag is “1” (S41). If it is determined in step S41 that the vehicle is moving forward (Yes), the diagnosis unit 25 calculates the road surface gradient amount using the above-described equation (1) (S42).

  If it is determined in step S41 that the vehicle does not tend to move forward (No), the diagnosis unit 25 determines whether or not the vehicle has a tendency to move backward, that is, whether or not the vehicle has a backward tendency flag (S43). ). If it is determined in step S43 that the vehicle has a tendency to move backward (Yes), the diagnosis unit 25 calculates the road surface gradient amount using the above-described equation (2) (S44). The road surface gradient amount is calculated by the above-described equation (3) (S45).

After steps S42, S44, and S45, the diagnostic means 25 acquires the accelerator opening θ and the vehicle body speed V (S46), and determines whether the accelerator opening θ is equal to or greater than a first predetermined value θ1 ( S47). In step S47, when the accelerator opening θ is less than θ1 (No), the diagnosis unit 25 sets 0 m / s ² as the road surface gradient amount addition value (S48).

In step S47, when the accelerator opening θ is equal to or greater than θ1 (Yes), the diagnosis unit 25 determines whether or not the vehicle body speed V is equal to or greater than a second predetermined value V1 (S49). In step S49, when the vehicle body speed V is less than V1 (No), the diagnosis unit 25 sets 0 m / s ² as the road surface gradient amount addition value (S48).

  In step S49, when the vehicle body speed V is equal to or higher than V1 (Yes), the diagnosis unit 25 determines whether or not the vehicle body speed V is equal to or higher than a third predetermined value V2 (S50). In step S50, when the vehicle body speed is V2 or higher (Yes), the diagnosis unit 25 sets VB as the road surface gradient amount addition value (S51), and when it is less than V2 (No), the road surface gradient. VA is set as the amount addition value (S52).

  After steps S48, S51, and S52, the diagnosis unit 25 determines whether or not the vehicle is stopped based on the stop flag output from the stop determination unit 23 (S53). In step S53, when the diagnosis unit 25 determines that the vehicle is stopped (Yes), the downhill running history is calculated by the above-described equation (4) (S54), and when it is determined that the vehicle is not stopped. (No), the downhill running history is calculated by the above-described equation (5) (S55).

  After steps S54 and S55, the diagnosis unit 25 determines whether or not the downhill travel history is less than the diagnosis permission threshold (S56). In step S56, when the diagnosis unit 25 determines that the downhill travel history is less than the diagnosis permission threshold (Yes), it determines that there is a downhill travel history (S57), and is greater than or equal to the diagnosis permission threshold. If it is determined (No), it is determined that there is no downhill traveling history (S58).

  The failure determination will be described in detail below. In FIG. 9, “vehicle traveling direction” means the traveling direction of the vehicle determined by the second traveling direction determination means 24, and “gear position direction” is determined by the first traveling direction determination means 21. It means the direction of travel of the vehicle.

  As shown in FIG. 9, the diagnosis unit 25 determines whether or not the vehicle traveling direction is forward (S21), and when it is forward (Yes), it determines whether or not the gear position direction is backward (S22). ). In step S22, when the vehicle is moving backward (Yes), there is a high possibility that the reverse switch 92 is fixed in the ON state (hereinafter referred to as ON-fixed). It is determined whether or not there is a travel history (S23).

  In step S23, when there is no downhill traveling history (No), the diagnosis means 25 adds an ON fixed failure counter (S24), and when there is a downhill traveling history (Yes), the ON fixed failure counter. The process proceeds to step S26 without adding. Here, the “ON sticking fail counter” is a timer (measurement time) for determining whether or not the reverse switch 92 is sticking ON in a later step S31.

  In step S22, if the gear position direction is forward (No), since the vehicle traveling direction and the gear position direction coincide with each other, the diagnosis means 25 subtracts the ON fixed fail counter (S25). .

  After Steps S24 and S25, after No is determined in Step S21, or after Yes is determined in Step S23, the diagnosis unit 25 determines whether the vehicle traveling direction is backward (S26). In step S26, when the vehicle signal direction is reverse (Yes), the diagnosis unit 25 determines whether the gear position direction is forward (S27).

  In step S27, when the gear position direction is forward (Yes), the diagnosis unit 25 is highly likely to have the reverse switch 92 fixed in the OFF state (hereinafter referred to as OFF fixation). In order to proceed with the failure determination, it is determined whether there is a downhill traveling history (S28).

  In step S28, when there is no downhill traveling history (No), the diagnosis means 25 adds an OFF fixed failure counter (S29), and when there is a downhill traveling history (Yes), the OFF fixed failure counter. The process proceeds to step S31 without adding. Here, the “OFF sticking fail counter” is a timer (measurement time) for determining in a later step S33 whether or not the reverse switch 92 is stuck OFF.

  In step S27, if the gear position direction is reverse (No), the vehicle traveling direction and the gear position direction coincide with each other, so the diagnosis unit 25 subtracts the OFF fixed fail counter (S30). .

  After steps S29 and S30, after determining No in step S26, or after determining Yes in step S28, the diagnostic means 25 determines whether or not the ON sticking fail counter is equal to or greater than the ON threshold (S31). ). In step S31, when the ON fixing fail counter is equal to or larger than the ON threshold (Yes), the diagnosis unit 25 determines that the reverse switch 92 has failed due to ON fixing (S32).

  In step S31, when the ON sticking fail counter is less than the ON threshold (No), the diagnosis unit 25 determines whether the OFF sticking fail counter is equal to or more than the OFF threshold (S33). In step S33, when the OFF sticking fail counter is equal to or greater than the OFF threshold (Yes), the diagnosis unit 25 determines that the reverse switch 92 has failed due to the OFF sticking (S34). In step S33, when the OFF sticking fail counter is less than the OFF threshold, the failure determination is terminated without determining the ON sticking or the OFF sticking.

According to the above, the following effects can be obtained in the present embodiment.
Before and after the differential value of the wheel acceleration based on the wheel speed acquired from the wheel speed sensor 91 that cannot determine whether the vehicle is moving forward or backward is calculated based on information (information from the longitudinal acceleration sensor 93) different from the wheel speed. By comparing with the differential value of acceleration, the comparison result becomes different depending on the forward / backward movement of the vehicle. Therefore, even when the wheel speed sensor 91 that cannot determine whether the vehicle is moving forward or backward is used, the traveling direction of the vehicle can be determined.

  Since the phenomenon in which the differential value of the longitudinal acceleration and the differential value of the wheel acceleration are output to the same sign side (for example, the plus side) at the time of forward movement of the vehicle is effectively used, forward determination can be performed.

  Since the phenomenon in which the differential value of the longitudinal acceleration and the differential value of the wheel acceleration are output to different sign sides (plus side and minus side) at the time of reverse of the vehicle is utilized effectively, the reverse determination can be performed. In particular, in this embodiment, since the reverse determination and the forward determination described above are combined, the traveling direction of the vehicle can be determined more accurately.

  Since the traveling direction of the vehicle is determined using the differential value of each acceleration, it is possible to accurately determine the forward / reverse direction without being affected by the road surface gradient.

  Since the differential value of the wheel acceleration can be calculated from the wheel speed of the driven wheel which is not affected by the driving force of the vehicle and is less likely to slip with the road surface, it is possible to determine forward / reverse more accurately.

  If there is a downhill running history indicating that the vehicle has traveled down the slope, failure determination is prohibited, so if the vehicle is traveling independently of the driving force of the vehicle (natural acceleration due to gravity), It is possible to prevent the failure determination.

  In order to reflect whether or not the vehicle is descending regardless of the driving force in the result of the downhill running history, the road surface slope amount addition value is determined in advance according to each state of the vehicle. When it is determined that there is a downhill travel history calculated based on the road surface gradient amount addition value, there is a high possibility that the vehicle is going downhill regardless of the driving force. Therefore, when the vehicle is descending regardless of the driving force, failure determination can be reliably prohibited. Further, when it is determined that there is no downhill traveling history, there is a high possibility that the vehicle is traveling with the driving force, so that the failure determination can be performed well when the vehicle is traveling with the driving force. .

  When at least one of the conditions that the accelerator opening is less than the first predetermined value θ1 or the vehicle body speed is less than the second predetermined value V1 is satisfied, that is, the vehicle is likely to travel without depending on the driving force. Sometimes, the current value of the downhill traveling history is not made larger than the previous value, so that the failure determination at this time can be surely prohibited. That is, according to this, the road surface gradient amount addition value is appropriately set according to the conditions of the accelerator opening and the vehicle body speed, so that the vehicle can travel without depending on the driving force from the presence / absence of the accelerator operation or the vehicle body speed information. It is possible to classify in detail whether or not it is.

  When it is not determined that the vehicle has a forward or backward tendency, that is, when the forward / reverse tendency of the vehicle is uncertain, the current value and the previous value of the road surface slope amount are determined by strict filtering (filter coefficient 1). Therefore, the downhill running history can be easily prevented from falling below the diagnosis permission threshold due to temporary vehicle behavior. In addition, when the tendency of the vehicle to move forward / backward is determined, the fluctuation range between the current value and the previous value of the road surface gradient amount is increased by a loose filter process (filter coefficient 2), so that the downhill driving history is recorded on the actual road surface. It is possible to quickly follow the gradient amount.

In addition, this invention is not limited to the said embodiment, It can utilize with various forms so that it may illustrate below.
In the above embodiment, the reverse switch that directly detects the position of the reverse gear of the transmission is adopted as the reverse detection means, but the present invention is not limited to this. For example, the gear position is detected by detecting the position of the shift lever. A sensor that detects indirectly may be employed.

  In the embodiment, the value correlated with the longitudinal acceleration or the value correlated with the wheel acceleration is set as the differential value. However, the present invention is not limited to this, and for example, the acceleration may be used as it is as the value correlated with each acceleration. .

  In the above-described embodiment, the absolute value of the first positive threshold and the absolute value of the first negative threshold are set to the same value α, but the present invention is not limited to this, and the first positive threshold The absolute value of the threshold may be different from the absolute value of the first minus threshold. Similarly, the second positive threshold and the second negative threshold may be set so that their absolute values are different.

  In the above-described embodiment, the forward tendency flag and the backward tendency flag are described. However, the forward tendency and the backward tendency are determined by directly referring to the timer values of the forward timer and the backward timer without using these flags. You may do it.

DESCRIPTION OF SYMBOLS 20 Control part 21 1st advancing direction determination means 24 2nd advancing direction determination means 24a Wheel speed calculation part 24b Wheel acceleration calculation part 24c Longitudinal acceleration calculation part 24e Determination part 25 Diagnosis means 91 Wheel speed sensor 92 Reverse switch 93 Longitudinal acceleration sensor 100 Vehicle control device

Claims (11)

First traveling direction determination means for determining a traveling direction of the vehicle based on a reverse signal output from a reverse detection means for detecting that the gear position of the transmission is the reverse position;
Second traveling direction determination means for determining the traveling direction of the vehicle based on a signal different from the reverse signal;
Whether the reverse detection means is normal is determined based on whether the vehicle traveling direction determined by the first traveling direction determining means matches the vehicle traveling direction determined by the second traveling direction determining means. A vehicle control device having diagnostic means,
The second traveling direction determination means includes
A wheel speed calculation unit that calculates a wheel speed based on a signal output from a wheel speed sensor that detects only the rotation speed of the wheel;
A wheel acceleration calculating unit for calculating wheel acceleration based on the wheel speed;
A longitudinal acceleration calculation unit that calculates an acceleration in the longitudinal direction of the vehicle based on information different from the wheel speed as a longitudinal acceleration;
Compare the value correlated with the longitudinal acceleration and the value correlated with the wheel acceleration ,
Addition processing for adding a timer when the value correlated with the longitudinal acceleration and the value correlated with the wheel acceleration are both larger than the first plus threshold or both are smaller than the first minus threshold Run
When the value correlated with the longitudinal acceleration is larger than the first plus threshold and the value correlated with the wheel acceleration is smaller than the first minus threshold, or the value correlated with the longitudinal acceleration is Performing a subtraction process for subtracting a timer when a value smaller than a first negative threshold and a value correlated with the wheel acceleration is larger than the first positive threshold;
A vehicle control device, wherein when the timer exceeds a first predetermined time, it is determined that the vehicle is moving forward . The second traveling direction determination means includes
When the value correlated with the longitudinal acceleration is larger than the second plus threshold and the value correlated with the wheel acceleration is smaller than the second minus threshold, or the value correlated with the longitudinal acceleration is An addition process for adding a timer when a value smaller than a second negative threshold value and correlated with the wheel acceleration is larger than the second positive threshold value;
A subtraction process for subtracting a timer when the value correlated with the longitudinal acceleration and the value correlated with the wheel acceleration are both larger than the second plus threshold or both are smaller than the second minus threshold. Run
2. The vehicle control device according to claim 1, wherein when the timer exceeds a second predetermined time, it is determined that the vehicle is moving backward. First traveling direction determination means for determining a traveling direction of the vehicle based on a reverse signal output from a reverse detection means for detecting that the gear position of the transmission is the reverse position;
Second traveling direction determination means for determining the traveling direction of the vehicle based on a signal different from the reverse signal;
Whether the reverse detection means is normal is determined based on whether the vehicle traveling direction determined by the first traveling direction determining means matches the vehicle traveling direction determined by the second traveling direction determining means. A vehicle control device having diagnostic means,
The second traveling direction determination means includes
A wheel speed calculation unit that calculates a wheel speed based on a signal output from a wheel speed sensor that detects only the rotation speed of the wheel;
A wheel acceleration calculating unit for calculating wheel acceleration based on the wheel speed;
A longitudinal acceleration calculation unit that calculates an acceleration in the longitudinal direction of the vehicle based on information different from the wheel speed as a longitudinal acceleration;
Compare the value correlated with the longitudinal acceleration and the value correlated with the wheel acceleration ,
When the value correlated with the longitudinal acceleration is larger than the second plus threshold and the value correlated with the wheel acceleration is smaller than the second minus threshold, or the value correlated with the longitudinal acceleration is An addition process for adding a timer when a value smaller than a second negative threshold value and correlated with the wheel acceleration is larger than the second positive threshold value;
A subtraction process for subtracting a timer when the value correlated with the longitudinal acceleration and the value correlated with the wheel acceleration are both larger than the second plus threshold or both are smaller than the second minus threshold. Run
A vehicle control device, wherein when the timer exceeds a second predetermined time, it is determined that the vehicle is moving backward . The diagnostic means includes
When a vehicle travels down a slope with natural acceleration using gravity, it calculates a downhill travel history indicating that the vehicle has descended, and when the vehicle stops after traveling, the downhill travel history up to that point is calculated. A history calculation unit that clears
It is always determined whether or not there is the downhill running history while the vehicle is traveling and stopped, and when it is determined that there is no downhill running history, it is determined whether or not the reverse detection means is normal And a diagnosis permission unit that prohibits determination of whether or not the reverse detection means is normal when it is determined that there is the downhill traveling history. The vehicle control device according to claim 3 . First traveling direction determination means for determining a traveling direction of the vehicle based on a reverse signal output from a reverse detection means for detecting that the gear position of the transmission is the reverse position;
Second traveling direction determination means for determining the traveling direction of the vehicle based on a signal different from the reverse signal;
Whether the reverse detection means is normal is determined based on whether the vehicle traveling direction determined by the first traveling direction determining means matches the vehicle traveling direction determined by the second traveling direction determining means. A vehicle control device having diagnostic means,
The second traveling direction determination means includes
A wheel speed calculation unit that calculates a wheel speed based on a signal output from a wheel speed sensor that detects only the rotation speed of the wheel;
A wheel acceleration calculating unit for calculating wheel acceleration based on the wheel speed;
A longitudinal acceleration calculation unit that calculates an acceleration in the longitudinal direction of the vehicle based on information different from the wheel speed as a longitudinal acceleration;
Compare the value correlating with the longitudinal acceleration and the value correlating with the wheel acceleration to determine the traveling direction of the vehicle ,
The diagnostic means includes
When a vehicle travels down a slope with natural acceleration using gravity, it calculates a downhill travel history indicating that the vehicle has descended, and when the vehicle stops after traveling, the downhill travel history up to that point is calculated. A history calculation unit that clears
It is always determined whether or not there is the downhill running history while the vehicle is traveling and stopped, and when it is determined that there is no downhill running history, it is determined whether or not the reverse detection means is normal And a diagnosis permission unit that prohibits determination of whether or not the reverse detection means is normal when it is determined that there is a downhill traveling history. . The history calculation unit
A road surface gradient amount calculating unit for calculating a road surface gradient amount from a deviation between the longitudinal acceleration and the wheel acceleration;
In order to reflect whether or not the vehicle is going downhill regardless of the driving force in the result of the downhill running history, an addition for acquiring a road surface slope amount addition value determined in advance according to each state of the vehicle A value acquisition unit,
It is configured to calculate the downhill traveling history based on the road surface gradient amount and the road surface gradient amount addition value,
The diagnosis permission unit
It is determined that there is no downhill travel history when the downhill travel history is equal to or greater than a diagnosis permission threshold, and it is determined that there is the downhill travel history when the downhill travel history is less than the diagnosis permission threshold. The vehicle control device according to claim 4 or 5 . The addition value acquisition unit
It has a vehicle body speed acquisition unit that acquires the vehicle body speed, and an accelerator opening acquisition unit that acquires the accelerator opening,
The road slope gradient addition value is the current value of the downhill travel history when the accelerator opening is less than a first predetermined value or the vehicle body speed is less than a second predetermined value. The vehicle control device according to claim 6 , wherein the vehicle control device is set to a value that does not exceed a previous value of the downhill traveling history. The second traveling direction determination means includes
Addition processing for adding a timer when the value correlated with the longitudinal acceleration and the value correlated with the wheel acceleration are both larger than the first plus threshold or both are smaller than the first minus threshold Run
When the value correlated with the longitudinal acceleration is larger than the first plus threshold and the value correlated with the wheel acceleration is smaller than the first minus threshold, or the value correlated with the longitudinal acceleration is Performing a subtraction process for subtracting a timer when a value smaller than a first negative threshold and a value correlated with the wheel acceleration is larger than the first positive threshold;
When the timer determines that the vehicle is moving forward when a first predetermined time is exceeded, and the vehicle is in a forward tendency when a third predetermined time shorter than the first predetermined time is exceeded Judgment,
The road surface gradient amount calculation unit
After the vehicle is determined to be a forward tendency, the road surface gradient of the previous value and filtering the fluctuation range such increase of the present value of the filter processing performed before it is determined that the forward tendency It was the vehicle control device according to claim 6 or claim 7, and calculates the road surface gradient magnitude. The second traveling direction determination means includes
When the value correlated with the longitudinal acceleration is larger than the second plus threshold and the value correlated with the wheel acceleration is smaller than the second minus threshold, or the value correlated with the longitudinal acceleration is An addition process for adding a timer when a value smaller than a second negative threshold value and correlated with the wheel acceleration is larger than the second positive threshold value;
A subtraction process for subtracting a timer when the value correlated with the longitudinal acceleration and the value correlated with the wheel acceleration are both larger than the second plus threshold or both are smaller than the second minus threshold. Run
The timer determines that the vehicle is moving backward when the second predetermined time is exceeded, and the vehicle is in a backward tendency when the fourth predetermined time shorter than the second predetermined time is exceeded. Judgment,
The road surface gradient amount calculation unit
After the vehicle is determined to be a backward tendency, the road surface gradient of the previous value and filtering the fluctuation range such increase of the present value of the filter processing performed before is determined to be backward trend The vehicle control device according to any one of claims 6 to 8 , wherein the road surface gradient amount is calculated. The value correlated with the longitudinal acceleration is a differential value of the longitudinal acceleration,
The vehicle control device according to any one of claims 1 to 9 , wherein the value correlated with the wheel acceleration is a differential value of the wheel acceleration. The vehicle according to any one of claims 1 to 10 , wherein the wheel speed calculation unit calculates a wheel speed based on a signal output from a wheel speed sensor provided on a driven wheel. Control device.

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