JP2679530B2 - Doppler ground speed detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a vehicle speed to ground, which is a traveling speed of a vehicle with respect to a road surface, by utilizing the Doppler effect of waves, and more particularly to a technique for improving the detection accuracy thereof. is there.

[0002]

2. Description of the Related Art As disclosed in Japanese Patent Laid-Open No. 61-14586, there is already known a device for detecting a vehicle speed to ground by utilizing the Doppler effect of waves. This Doppler ground vehicle speed detection device is generally (a) a transmitting unit that is mounted on the vehicle body and transmits waves toward the road surface, and (b) is a vehicle-mounted transmitting unit that transmits the wave to the road surface. And (c) a ground vehicle speed determining means for determining the ground vehicle speed, which is the traveling speed of the vehicle with respect to the road surface, based on the transmission frequency of the transmitter and the reception frequency of the receiver. Composed.

[0003]

The transmitting part and the receiving part are usually fixed to the vehicle body so that the angle formed by the road surface, that is, the angle formed by the vehicle traveling direction, is fixed, and the conventional Doppler type ground vehicle speed detection is performed. The device uses only the transmission frequency and the reception frequency based on the assumption that the angle formed by the transmission unit and the reception unit during traveling of the vehicle and the vehicle traveling direction (hereinafter, simply referred to as the angle of the transmission unit, etc.) is always kept constant. It was supposed to uniquely detect the ground vehicle speed.

However, the angle of the transmitting section or the like is not always kept constant while the vehicle is traveling. This is because, for example, during vehicle acceleration, vehicle deceleration, and vehicle braking, the vehicle body tilts from the reference state in the front-rear direction, and the angles of the transmission unit and the like change accordingly. Therefore, the conventional device has a problem that the detection accuracy of the ground vehicle speed cannot always be kept high.

On the basis of the above circumstances, the invention of claim 1 solves the problem by utilizing the fact that there is a certain relationship between the angle of the transmitter and the acceleration / deceleration of the vehicle body. The task was to do.

The Doppler type ground vehicle speed detecting device is generally used together with a device for controlling the motion state of the vehicle, and one of such vehicle controlling devices is an antilock control device.

The anti-lock control device used with the Doppler type ground vehicle speed detecting device usually comprises a plurality of wheel speed sensors, and each wheel speed detected by each wheel speed sensor and the Doppler type ground vehicle speed detecting device are detected. Based on the relationship with the ground vehicle speed, the brake pressure of each wheel is controlled so that each wheel does not fall into a locked state during vehicle braking.

An example of the Doppler type ground speed detecting device used with such an antilock control device is as follows:
The vehicle speed is sequentially estimated from the plurality of wheel speeds detected by the plurality of wheel speed sensors, and the current acceleration / deceleration is acquired as the difference between the current value and the previous value of the estimated vehicle speed. However, since the acceleration / deceleration obtained in this way usually varies widely, such acquired values are not used as they are, but the acquired value of each time is used as the sample acceleration / deceleration from this time to the past multiple times. It is usual to use the average value of a plurality of sample accelerations / decelerations as the true value of this acceleration / deceleration.

In such a Doppler type ground vehicle speed detecting device, normally, the number of sample accelerations / decelerations used for determining the true acceleration / deceleration at each time is always constant. However, the characteristics required for the true acceleration / deceleration to be acquired,
That is, the degree to which the variation in the true acceleration / deceleration should be reduced and the degree to which the response of the true acceleration / deceleration to the change in the actual acceleration / deceleration should be increased are not constant at any time in the braking state. Therefore, if the number of sample accelerations / decelerations used to determine the true acceleration / deceleration at each time is always constant, the true acceleration / deceleration during braking cannot always be obtained with the desired characteristics, which in turn results in the detection accuracy of the ground vehicle speed. There is a problem that it cannot always be kept high.

Further, since there is a period during which the error of the estimated vehicle speed temporarily increases significantly during the antilock control, a plurality of past sample accelerations / decelerations based on the estimated vehicle speed are present at any time during the antilock control. When acquiring the true acceleration / deceleration at each time, the accuracy of the true acceleration / deceleration decreases due to the error of the estimated vehicle speed, and thus the accuracy of the ground vehicle speed also decreases.

Below, the causes of these two problems are shown in FIG.
This will be described in detail with reference to 7. If the operating force applied to the brake master cylinder of the vehicle becomes excessive in relation to the friction coefficient of the road surface, the slip ratios of all the wheels will increase at a substantially similar rate. Therefore, the estimated vehicle speed based on the wheel speed usually falls gradually with respect to the actual ground vehicle speed. Further, before the antilock control is started, the brake pressure of each wheel is not yet controlled, so that the variation in the estimated vehicle speed based on the variation in the wheel speed is almost the same as in the non-braking state. Presumed.

After that, if the antilock control is started,
Since the brake pressure of each wheel is suddenly reduced, the slip ratio of each wheel is reduced, the decreasing tendency of each wheel speed is suppressed, and eventually the increasing tendency is started. At this time, the estimated vehicle speed also normally changes from a decreasing tendency to an increasing tendency. When the anti-lock control is started in this way, the estimated vehicle speed at the beginning thereof is significantly reduced from the actual vehicle speed to ground, and a period during which the estimated vehicle speed is increased will temporarily occur.

Due to the effect of the antilock control, the estimated vehicle speed then starts to decrease following the actual vehicle speed to ground, but thereafter the brake pressure of each wheel is increased and decreased almost periodically. Therefore, in this period, the wheel speeds vary a little, and the estimated vehicle speed based on such wheel speeds also vary a lot.

Therefore, the period during which one braking operation is performed with anti-lock control is divided into four periods, that is, the period A from the braking start timing to the start of the anti-lock control and the end timing thereof. Period B until the estimated vehicle speed starts to increase due to the effect of lock control
And a period C from the end time thereof to the time when the estimated vehicle speed starts decreasing and a period D from the end time thereof to the end of the antilock control (in FIG. 17, “I” means the sum of the above periods A and B, “II” means the above period C, and “III”
Means the period D), and the variation in the estimated vehicle speed is larger than the period A in the periods B to D. This is because the brake pressure of each wheel is not yet under the antilock control in the period A. Further, the accuracy of the estimated vehicle speed (degree of coincidence with the actual ground vehicle speed) is lower in the periods B and C than in the other periods A and D.

In order to accurately determine the true acceleration / deceleration from a plurality of sample accelerations / decelerations based on the estimated vehicle speed, it is not enough to consider the variation of the estimated vehicle speed, and it is also necessary to consider the responsiveness to the change of the actual ground vehicle speed. It is essential. Then, the tendency of the inclination angle of the vehicle body, that is, the angle of the transmitting unit or the like to change is generally stronger in the period A than in the other periods B to D. It is essential to improve the responsiveness to the period A in the period A more than in the other periods B to D.

From these circumstances, during braking, the true acceleration / deceleration of each time is sequentially determined from a plurality of past sample acceleration / deceleration, and the number of sample acceleration / deceleration used for determining the true acceleration / deceleration of each time. If is always constant, period A
Improvement of response of genuine acceleration / deceleration and period B and C
It is impossible to simultaneously improve the accuracy of the true acceleration / deceleration in step S1 and the suppression of the variation in the true acceleration / deceleration in the period D, and it is not possible to constantly maintain high accuracy in detecting the ground vehicle speed in the braking state accompanied by antilock control. Problems arise.

The invention of claim 2 is made as one mode of use of the invention of claim 1 to solve the problem, and is used together with an anti-lock control device and is in a vehicle braking state. Is a Doppler-type ground vehicle speed detection device suitable for acquiring the acceleration / deceleration of the vehicle body using the wheel speed sensor.

The Doppler-type ground vehicle speed detecting apparatus according to the second aspect of the present invention is an indirect method for estimating the vehicle speed from the wheel speed as a method for obtaining the acceleration / deceleration of the vehicle body and indirectly obtaining the acceleration / deceleration as a time differential value thereof. However, a direct method in which the acceleration / deceleration sensor directly acquires the acceleration / deceleration can also be adopted.

When this direct system is adopted, of one braking period, at the beginning of the braking period, rather than in the latter period,
Since the tilting motion of the vehicle body is transient, it is required to accelerate the responsiveness to changes in the actual acceleration / deceleration of the vehicle body to acquire the acceleration / deceleration, which is consistent with the indirect method. However, even in the anti-lock control, the acquisition accuracy does not usually decrease a little, so it is different from the indirect method in this respect.

Based on such a situation, the invention of claim 3 is an application mode of the invention of claim 1, and is a Doppler equation suitable for obtaining the acceleration / deceleration of the vehicle body in a vehicle braking state by a direct method. The object is to provide a ground vehicle speed detection device.

[0021]

The gist of the invention of claim 1 is, as shown in FIG. 1, a Doppler type ground vehicle speed detecting device including the transmitting portion 1, the receiving portion 2 and the ground vehicle speed determining means 3. the acceleration acquiring means 4 acquires acceleration provided, and a ground vehicle speed determining means 3, not only the transmission frequency and reception frequency, collected by acceleration obtaining unit 4 <br/> obtained been deceleration, the Acceleration / deceleration and transmitter 1 and receiver
The ground vehicle speed is determined based on the relationship with the actual angle of the receiver 2 with respect to the road surface .

The "acceleration / deceleration acquisition means 4" herein may be, for example, a sensor for directly detecting the acceleration / deceleration, or indirectly estimating the vehicle speed from the wheel speed and indirectly obtaining it as a time differential value thereof. You can

The gist of the invention of claim 2 is, as shown in FIG. 2, the relationship between each wheel speed detected by each wheel speed sensor for each of a plurality of wheels and the ground vehicle speed determined by the ground vehicle speed determining means 3. The Doppler-type ground vehicle speed detecting device according to claim 1, wherein the anti-lock control device is provided in the anti-lock control device for controlling the brake pressure of each wheel so as not to fall into a locked state when the vehicle is braked. The "acceleration / deceleration acquisition means 4" includes (a) a vehicle speed estimating means 5 for sequentially estimating a vehicle speed from a plurality of wheel speeds detected by a plurality of wheel speed sensors, and (b) a current value and a previous value of the estimated vehicle speed. The sample acceleration / deceleration determining means 6 that determines the sample acceleration / deceleration to be the current time, and (c) the sample acceleration / deceleration determining means 6 sequentially takes in the sample acceleration / deceleration, and the braking is started after one braking is started. Basis In the first period between the start time of anti-lock control and the time when the estimated vehicle speed starts to increase due to the effect of the anti-lock control, the sample acceleration / deceleration from this time to the past multiple times is set in the first period. The first candidate acceleration / deceleration based on this is the true acceleration / deceleration of this time, and the final value of the first candidate acceleration / deceleration in the first period in the second period from the end of the first period until the estimated vehicle speed starts to decrease. The true acceleration / deceleration of each time is fixed to
In the third period from the end of the second period to the end of the antilock control, the number of sample accelerations / decelerations greater than the number of sample accelerations / decelerations of the first candidate acceleration / deceleration from this time to the past multiple times is set. The second candidate acceleration / deceleration based on the true acceleration / deceleration is included in the true acceleration / deceleration determining means 7.

The gist of the invention of claim 3 is, as shown in FIG. 3, "acceleration / deceleration acquisition means 4" in the invention of claim 1.
(A) acceleration / deceleration sensor 8 that directly detects the acceleration / deceleration of the vehicle body, and (b) sequentially determines the sample acceleration / deceleration based on the output signal from the acceleration / deceleration sensor, and at the beginning of one braking, Is the first candidate acceleration / deceleration based on a plurality of sample accelerations / decelerations from this time to the past multiple times as the true acceleration / deceleration of this time, and in the latter period, the sample acceleration / deceleration of the first candidate acceleration / deceleration from this time to past times This is to include the true acceleration / deceleration determining means 9 for setting the second candidate acceleration / deceleration based on the sample acceleration / deceleration larger than the number of speeds as the true acceleration / deceleration of this time.

The "genuine acceleration / deceleration determining means 7, 9" in each of the second and third aspects of the present invention is "first and second based on a plurality of sample acceleration / deceleration from this time to a plurality of past times.
Assuming that the plurality of sample accelerations / decelerations are originally the same, the candidate acceleration / deceleration is assumed to be acquired as an average value of the plurality of sample accelerations / decelerations, or linearly changes with time. Then, a regression line may be obtained from the plurality of sample accelerations / decelerations, and the true acceleration / deceleration of this time may be statistically estimated using the regression line.

[0026]

In the Doppler type ground vehicle speed detecting device according to each of claims 1 to 3, the acceleration / deceleration acquisition means 4 acquires the acceleration / deceleration of the vehicle body, and the ground vehicle speed determination means 3
Not only the transmission frequency and the reception frequency, but also the acquired acceleration / deceleration , the acceleration / deceleration, and the transmitter 1 and the receiver 2.
The ground vehicle speed is also determined based on the relationship with the actual angle with respect to the road surface .

There is usually a certain relationship between the acceleration / deceleration of the vehicle body and the vehicle body inclination angle, that is, the amount of variation in the angle of the transmitting section or the like. Therefore, if the ground vehicle speed determining means 3 uses, for example, the relationship, and estimates the angle of the transmitting unit or the like based on the acquired acceleration / deceleration, and determines the ground vehicle speed in consideration thereof, The vehicle speed to ground can be accurately detected with almost no influence of the inclination of. Here, the acceleration / deceleration, the vehicle body inclination angle, the transmitter, etc.
The relationship between the angle variation amounts will be briefly described. example
For example, when the transmitter etc. is diagonally forward to the vehicle body, the angle is θ ₀ .
When the vehicle is moving forward,
Think. The vehicle leans forward when braking or decelerating
However, the angle θ ₀ of the transmitter and other parts increases, but
At both accelerations, the posture becomes backward, so the angle θ ₀
Becomes smaller. On the other hand, if the transmitter etc. is facing diagonally backward
Therefore, in the case where it is fixed at an angle θ ₀ ,
During vehicle braking or deceleration, the angle θ ₀ of the transmitter is small.
However, since the angle θ ₀ increases when the vehicle accelerates,
is there. Also, the magnitude of the variation of the angle θ ₀ of the transmission unit is
It changes according to the acceleration and deceleration of the vehicle body. High acceleration / deceleration
When the threshold is small, the vehicle body inclination angle is larger than when it is small,
The amount of variation in the angle of the transmitter and the like becomes large.

As described above, four periods, that is, a period A from the braking start time to the antilock control start and the end time of the antilock control are defined as the periods in which one braking operation with antilock control is performed. From period B until the estimated vehicle speed starts to increase due to the effect of anti-lock control
And the period C from the end of it to the time when the estimated vehicle speed starts to decrease, and the period D from the end of it to the end of the antilock control, the lean angle of the vehicle body is In particular, the period A has a strong tendency to fluctuate, but the other periods B to D generally have a tendency to be almost stable. Therefore, as a method of acquiring the true acceleration / deceleration in the periods A to C, (a) the true acceleration / deceleration is sequentially determined based on the estimated vehicle speed in the period A, and the true acceleration / deceleration is determined in the periods B and C. A method of fixing the value to the value, or (b) a method of sequentially determining the true acceleration / deceleration based on the estimated vehicle speed in periods A and B, and fixing the true acceleration / deceleration to the final value in periods A and B in period C. Can be adopted.

As a method of acquiring the true acceleration / deceleration in the periods A and D, in the period A, the true acceleration / deceleration is determined based on a small number of past sample decelerations in order to improve the acquisition responsiveness. On the other hand, in the period D, a method of determining the true acceleration / deceleration based on a large number of past sample accelerations / decelerations can be adopted in order to suppress the acquisition variation.

Based on these circumstances, in the Doppler type ground vehicle speed detecting device according to the invention of claim 2, claim 1
The "acceleration / deceleration acquisition means 4" in the invention of claim 1 includes the vehicle speed estimation means 5, the sample acceleration / deceleration determination means 6 and the true acceleration / deceleration determination means 7, whereby (a) one braking is started. From the start time of the antilock control based on the braking to the start time of the estimated vehicle speed due to the effect of the antilock control from the start time to the first time period (only the above period A or the periods A and B). (According to the sum period of), the first candidate acceleration / deceleration based on a plurality of sample accelerations / decelerations from this time to the past multiple times is regarded as the true acceleration / deceleration of this time, and (b) the first period ends. From the second period until the estimated vehicle speed begins to decrease (the above period B
And the period of the sum of C, or the period C), the true acceleration / deceleration of each time is fixed to the final value of the first candidate acceleration / deceleration in the first period, and (c) the second period ends. During the third period (corresponding to the above period D) from the start to the end of the antilock control, the number of sample accelerations / decelerations greater than the number of sample accelerations / decelerations of the first candidate acceleration / deceleration from this time to the past multiple times. The second candidate acceleration / deceleration based on is the true acceleration / deceleration of this time.

In contrast to the case where the indirect method in which the acceleration / deceleration of the vehicle body is indirectly obtained by using the wheel speed sensors is adopted as described above, the case where the direct method in which the acceleration / deceleration sensor is directly obtained is adopted is described above. As described above, it is sufficient to acquire the true acceleration / deceleration in the initial period of braking, and in the latter half of the braking, to acquire the true acceleration / deceleration by emphasizing the variation suppression, and as in the case of adopting the indirect method, the true acceleration / deceleration in a certain period. Temporary fixing is not essential.

Based on such circumstances, in the Doppler type ground vehicle speed detecting device according to the invention of claim 3, the "acceleration / deceleration acquisition means 4" in the invention of claim 1 determines the acceleration / deceleration sensor 8 and the true acceleration / deceleration determination. Therefore, the first candidate acceleration / deceleration based on a plurality of sample accelerations / decelerations from this time to a plurality of past times is set as the true acceleration / deceleration of this time at the beginning of one braking. In the latter half, the second candidate acceleration / deceleration based on a larger number of sample acceleration / deceleration than the number of sample acceleration / deceleration of the first candidate acceleration / deceleration from this time to the past multiple times is set as the true acceleration / deceleration of this time.

[0033]

As is apparent from the above description, according to each of the first to third aspects of the present invention, the ground vehicle speed is sufficiently high regardless of the inclination of the vehicle body, that is, the inclination of the transmitting portion and the receiving portion. The effect that it can be detected is obtained.

In particular, according to the second aspect of the present invention, in the Doppler type ground vehicle speed detecting device which is used together with the antilock control device and which estimates the vehicle speed from the wheel speed to indirectly obtain the acceleration / deceleration, There is also an effect that the detection accuracy of the ground vehicle speed in the braking state accompanied by the lock control is improved, and the accuracy of the antilock control is improved. Further, since it is not necessary to provide a dedicated sensor for acquiring the acceleration / deceleration, there is an effect that the device cost is reduced.

Further, in particular, according to the invention of claim 3, in the Doppler type ground vehicle speed detecting device of the type in which the acceleration / deceleration of the vehicle body is directly obtained by using the acceleration / deceleration sensor, the ground vehicle speed in one braking state is measured. The effect of improving the detection accuracy is also obtained.

[0036]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described below in detail with reference to the drawings.

First, a Doppler type ground vehicle speed detecting apparatus according to an embodiment of the present invention will be described. As shown in FIG. 4, the present Doppler type ground vehicle speed detection device 10 includes a transmitter 12,
The receiver 14 and the ground vehicle speed detection computer 16 are provided. Both the transmitter 12 and the receiver 14 (see FIG. 6) are fixedly attached to the bottom surface of the vehicle body in a posture facing the front of the vehicle and obliquely facing the road surface. Both the transmission direction of the transmission unit 12 and the reception direction of the reception unit 14 are such that when the vehicle in a stopped state is viewed from the side, the angle formed by each of the transmission direction and the reception direction and the road surface (that is, the vehicle traveling direction) is The reference value θ ₀ is set.

The ground vehicle speed detection computer 16 sends to the transmitter 12 a signal for transmitting ultrasonic waves (this is one mode of "wave" in the invention of claim 1) at a constant transmission frequency f _T. Supply. The transmitted wave is reflected on the road surface, and a part of the reflected wave is received by the receiving unit 14. The receiving unit 14 receiving the reflected wave supplies a signal corresponding to the received frequency f _R to the ground vehicle speed detection computer 16. Then, the ground vehicle speed detection computer 16 detects the ground vehicle speed u based on the transmission frequency f _T and the reception frequency f _R. The method of detecting the ground vehicle speed u will be described in detail later.

An antilock control device 30 is connected to the output part of the ground vehicle speed detection computer 16. As shown in FIGS. 5 and 6, the antilock control device 30 detects the wheel speed V of each of the left and right front wheels and the left and right rear wheels of the vehicle at the input part of the antilock control computer 32.
Wheel speed sensors 34 and a brake switch 38 for detecting the depression of the brake pedal by the driver are connected, and a plurality of solenoid valves 42 (for controlling the pressure in the wheel cylinder of the brake 40 of each wheel are output to the output section). A brake master cylinder (not shown) is connected to the reservoir) and a pump 44 for collecting the brake fluid discharged from each wheel cylinder to the reservoir to the brake master cylinder are connected.

As shown in FIG. 4, the ground vehicle speed detection computer 16 is also connected to the four wheel speed sensors 34 and the brake switch 38, and the output signals from them and the output signal from the receiving section 14 are connected. The ground vehicle speed u is detected by executing various programs including the ground vehicle speed calculation routine represented by the flowchart of FIG.

This routine will be described below, but first, it will be briefly described. This routine includes four wheel speed sensors 3
4 is used to determine the amount of change in the inclination angle of the vehicle body with respect to the road surface from the reference state, and this is used as the amount of change Δθ from the reference angle θ _{0 with} respect to the road surface in the transmitter 12 and the receiver 14. . Further, the transmission frequency f _T of the transmitter 12
Based on the reception frequency f _R of the receiver 14 and the actual value θ of the inclination angle of the transmitter 12 and the receiver 14 with respect to the road surface (this is the sum of the reference angle θ ₀ and the variation Δθ)
The ground vehicle speed u of the vehicle is determined using the Doppler effect of ultrasonic waves.

Next, a detailed description will be given with reference to FIG. First, in step S1 (hereinafter, simply referred to as S1; the same applies to other steps), whether or not the brake switch 38 is in the ON state, that is, whether or not the vehicle is in the braking state (that is, the brake operation by the driver is performed. Is performed) is determined. Assuming that the vehicle is not in the braking state this time, the determination is NO, the variation amount Δθ of the angle of the transmission unit 12 and the like is set to 0 in S2, and the variation amount Δθ is stored in the RAM, and thereafter, the variation amount is determined in S3. Based on the amount Δθ, the reference angle θ ₀ of the transmitter 12 and the like, and the current transmission frequency f _T and reception frequency f _R , the ground vehicle speed u is calculated using the following equation.

U = [aΔf] / [[2f _T + Δf]
Cos (θ ₀ + Δθ)] where: a: traveling speed of ultrasonic wave Δf: Doppler shift (= reception frequency f _R −transmission frequency f _T )

The ground vehicle speed u thus calculated is stored in the RAM of the ground vehicle speed detection computer 16.
The antilock control computer 32 has its RAM
Then, the ground vehicle speed u is sequentially read out, and antilock control is performed for each wheel based on the read out vehicle speed u.

On the other hand, if it is assumed that the brake switch 38 is turned on because the brake pedal is depressed, the determination in S1 is YES, and the vehicle speed is changed from the four wheel speeds V by steps S4 and below. The deceleration G of the vehicle is estimated from the change in the estimated vehicle speed VSO (this is one mode of the "acceleration / deceleration" in the invention of claim 1), and the variation of the angle of the transmitter 12 or the like is obtained from the deceleration G. The amount Δθ is determined, and the ground vehicle speed u is determined using the variation Δθ.
Is calculated.

The acquisition of the deceleration G is performed as follows. That is, based on the fact that the estimated vehicle speed VSO normally matches the actual ground vehicle speed until 150 ms have elapsed from the start of one braking, the estimated vehicle speed VSO is
The time differential value of each is the deceleration G of each time, and after 150 ms has passed from the braking start time, it is normal that the estimated vehicle speed VSO temporarily deviates from the actual ground speed temporarily. And 150ms from the start of braking
Based on the fact that it is normal for the actual deceleration of the vehicle body to be kept substantially constant after the passage of
After the lapse of ms), the deceleration G of each time is
It is fixed to the final value at the beginning of braking (before the lapse of 150 ms). As a result, the variation amount Δ of the angle of the transmitter 12 or the like
θ is variable in the initial stage of braking, and is forcibly kept unchanged in the latter period of braking.

Specifically, first, in S4, it is determined whether or not the present time is within a period of 150 ms from the braking start timing. If this is the case this time, the determination is YES, and in S5, the determination in S4 is YES.
Is determined for the first time after the determination in S1 is YES. If this is the case this time, the determination is yes, in S6 the estimated vehicle speed VSO is calculated based on the four wheel speeds V, and in S7, in preparation for the first calculation of the deceleration G, This estimated vehicle speed VSO is set as the previous estimated vehicle speed VSOLD. After that, in S3, the current variation Δθ is determined to be the same as the value currently stored in the RAM, that is,
The ground vehicle speed u is calculated as 0.

The method of calculating the estimated vehicle speed VSO in S6 determines the estimated vehicle speed VSO by estimating that the wheel speed V of the fastest wheel having the maximum wheel speed V among the four wheels represents the vehicle speed. After the wheel deceleration of the fastest wheel exceeds a predetermined upper limit value, the wheel deceleration is fixed to the upper limit value to determine the estimated vehicle speed VSO.

After that, if S5 is executed and the determination is NO, the current time is 30 ms from the braking start time in S8.
It is determined whether or not they match the time when has passed. If this is not the case this time, the determination is no and the process moves to S3. Also this time, the variation amount Δθ is set to 0 and the ground vehicle speed u is calculated.

Thereafter, the execution of S1, 4, 5, 8 and 3 is repeated many times so that the determination in S8 is YES.
Then, in S9, the current estimated vehicle speed VSO is calculated in the same manner as in S6, and in S10, the current deceleration G is calculated by subtracting the current estimated vehicle speed VSO from the previous estimated vehicle speed VSOLD. continue,
In S11, in order to prepare for the next calculation of the deceleration G, the estimated vehicle speed VSO of this time is the estimated vehicle speed VSOL of the previous time.
D.

After that, in S12, the function g (previously stored in the ROM of the ground vehicle speed detection computer 16) that defines the relationship between the deceleration G and the variation amount Δθ of the angle of the transmission unit 12 or the like is stored. By substituting the deceleration G, the current fluctuation amount Δθ is calculated. Subsequently, in S13, the average value of the previous fluctuation amount ΔθOLD (initial value is 0) and the current fluctuation amount Δθ is set as the true value of the current fluctuation amount Δθ, and in S14, the true value of the next fluctuation amount Δθ. In order to prepare for the decision, the current fluctuation amount Δθ is the previous fluctuation amount ΔθO
It is considered as LD. Then, in S3, the ground vehicle speed u is calculated using the current variation amount Δθ. The variation Δ
The sum of θ and the reference angle θ ₀ is the actual mounting angle θ, and the ground vehicle speed u is calculated as described above based on this and the present transmission frequency f _T and reception frequency f _R.

Thereafter, each time the determination in S8 becomes YES, that is, every 30 ms, the estimated vehicle speed VS
O, deceleration G, and variation amount Δθ are calculated, and eventually, if 150 ms has elapsed from the braking start timing and the determination in S4 is NO, the variation amount Δθ is fixed to the latest value thereof, and the variation amount Δθ The ground vehicle speed u is calculated by using.

Thereafter, the execution of S1, 4 and 3 is repeated, and in each execution, the sum of the fixed variation amount Δθ and the reference angle θ ₀ is set as the actual mounting angle θ, and this and this transmission The ground vehicle speed u is calculated based on the frequency f _T and the reception frequency f _R. Then, when the braking of this time ends, the determination in S1 becomes NO, the variation amount Δθ is set to 0 in S2, and the vehicle speed u to ground is calculated using the variation amount Δθ in S3. After that, execution of S1, S2 and S3 is repeated, and in each execution, the variation amount Δθ is set to 0 and the ground vehicle speed u is calculated.

As is apparent from the above description, in the present embodiment, the transmission unit 1 changes from the deceleration G in the vehicle braking state.
Since the variation amount Δθ of the angle such as 2 is estimated and the ground vehicle speed u is detected by using it, the ground vehicle speed u can be accurately detected regardless of the brake dive of the vehicle body.

Further, in this embodiment, the wheel speed sensor 34 originally provided for the purpose other than the ground vehicle speed detection, that is, for antilock control can be diverted to improve the ground vehicle speed detection accuracy. Since it is not necessary to add a dedicated sensor for detecting the ground vehicle speed, the effect of reducing the cost for improving the detection accuracy of the ground vehicle speed u can be obtained.

As is apparent from the above description, in this embodiment, the portion of the ground vehicle speed detection computer 16 that executes S1, 4 to 11 of FIG. 7 is the "acceleration / deceleration acquisition means" in the invention of claim 1. 4 ”, and the portion that executes S2, 3, 12 to 14 in the figure constitutes one aspect of“ ground vehicle speed determining means 3 ”.

Next, a Doppler type ground vehicle speed detecting device which is an embodiment common to the inventions of claims 1 and 2 will be described.

This Doppler type ground vehicle speed detecting device 60 is shown in FIG.
4, the transmitting unit 62, the receiving unit 64, and the ground vehicle speed detection computer 66, as in FIG.
The ground vehicle speed detection computer 66 is also connected to the four wheel speed sensors 34, the brake switch 38 and the antilock control device 30 as in the previous embodiment.

However, the manner in which the transmitter 62 and the receiver 64 are attached to the vehicle body is different from the previous embodiment. Specifically, the vehicle is directed rearward of the vehicle and diagonally opposed to the road surface. It is fixedly attached in a posture.

In the ROM of the ground vehicle speed detection computer 66, the estimated vehicle speed VSO calculation routine represented by the flowchart of FIG. 9, the sample deceleration GSMP calculation routine represented by the flowchart of FIG. 10, and the first routine represented by the flowchart of FIG. 1 Average deceleration GMEAN1 calculation routine, FIG.
Second average deceleration GMEA represented by the flowchart in FIG.
Various programs including the N2 calculation routine and the ground vehicle speed calculation routine represented by the flowchart of FIG. 13 are stored. Each of these routines is executed by the CPU on a regular basis. Each routine will be described below.

In the estimated vehicle speed VSO calculation routine of FIG. 9, first, in S21, each wheel speed V is calculated based on the output signal from each wheel speed sensor 34. Subsequently, in S22, the estimated vehicle speed VSO is calculated based on the calculated four wheel speeds V in the same manner as in S6 and 9 of FIG. 7, and in S23, the calculated estimated vehicle speed VS.
O is stored in the RAM of the ground vehicle speed detection computer 66. This completes one execution of this routine.

In the sample deceleration GSMP calculation routine of FIG. 10, first, the previous value of the estimated vehicle speed VSO is read from the RAM in S31, and the current value of the estimated vehicle speed VSO is read in S32. Subsequently, in S33, the current sample deceleration GSMP is calculated as a value obtained by subtracting the current value from the previous value of the estimated vehicle speed V, and the calculated sample deceleration GSMP is stored in the RAM in S34. It should be noted that a plurality of times of sample deceleration are stored in the RAM in association with the detection order. This completes one execution of this routine.

In the first average deceleration GMEAN1 calculation routine of FIG. 11, first, in S41, the latest M sample decelerations GSMP are read out, and subsequently in S42, the average values of them are calculated as the average values. First of
Average deceleration GMEAN1 (hereinafter, simply deceleration GMEAN
One. In addition, this is the "first" in the invention of claim 2.
Is a mode of “candidate acceleration / deceleration”) is calculated. Then, in S43, the calculated deceleration GMEAN
1 is stored in RAM. This completes one execution of this routine. The M sample decelerations GSMP are assumed to be detected within a period of 20 to 30 ms, for example.

In the second average deceleration GMEAN2 calculation routine of FIG. 12, first, in S51, the latest N (> M) sample decelerations GSMP are read out, and then in S52, those sample decelerations GSMP are read. The second average deceleration GMEAN2 (hereinafter, simply deceleration G as an average value)
It is called MEAN2. Further, this is an aspect of the "second candidate acceleration / deceleration" in the invention of claim 2). Then, in S53, the calculated deceleration G
MEAN2 is stored in RAM. This completes one execution of this routine. In addition, N sample deceleration GS
The MP is detected, for example, within a period of 100 to 500 ms.

The ground vehicle speed calculation routine shown in FIG. 13 will be described. First, it will be briefly described. In this routine, the variation amount Δθ of the angle of the transmitter 62 or the like is set to 0 in the non-braking state,
In the braking state where antilock control is not performed, the deceleration G
MEAN1 is the true deceleration, and the variation Δ
In a braking state in which θ is calculated and antilock control is performed, a _first period from the start of braking until a fixed time T ₁ elapses (this is one mode of the “first period” in the invention of claim 2). In the above, the deceleration GMEAN1 is set to the true deceleration, the variation amount Δθ is calculated based on the deceleration GMEAN1, and the _second period from the end timing of the first period to the elapse of the fixed time T ₂ (this is the invention in claim 2). "Second period"
Of the deceleration GMEAN1,
The final value in the first period is set as the true deceleration, the variation amount Δθ is calculated based on the true deceleration, and after the end of the second period (this is one mode of the “third period” in the invention of claim 2), The deceleration GMEAN2 is set as the true deceleration, and the variation amount Δθ is calculated based on the true deceleration. This routine also calculates the following equation based on the fluctuation amount Δθ calculated in this way, the reference mounting angle θ _{0 of} the transmitter 62 and the receiver 64, and the current transmission frequency f _T and reception frequency f _R. The ground vehicle speed u is calculated using this.

U = [aΔf] / [[2f _T + Δf]
· Cos (θ ₀ -Δθ)] However, a: ultrasonic rate of progress Delta] f: Doppler shift (= the transmission frequency f _T - reception frequency f _R)

The length of time T ₁ is set so that the estimated vehicle speed VSO expires when the estimated vehicle speed VSO changes from a decreasing tendency to an increasing tendency due to the effect of antilock control.
~ 700 ms. Further, the length of T ₂ time is set so as to expire when the estimated vehicle speed VSO starts to decrease substantially following the actual ground vehicle speed due to the effect of the antilock control, and is set to, for example, 400 to 700 ms.

Hereinafter, this ground vehicle speed calculation routine will be described in detail with reference to FIG. First, the non-braking state will be described. First, in S61, the brake switch 38
Is in the ON state, that is, it is determined whether or not it is in the braking state. Since it is assumed that this is not the case this time, the determination is NO, and in S62, the transmission unit 6
The variation amount Δθ of the angle such as 2 is set to 0. After that, S63
In, the ground vehicle speed u is calculated using the variation amount Δθ (0 this time). This completes one execution of this routine.

Next, a braking state in which antilock control is not performed will be described. First, if it is determined in S61 whether or not the brake switch 38 is in the ON state, it is assumed that the brake state is in the braking state this time, so the determination is YES. Subsequently, in S64, it is determined whether or not it is currently within T ₁ time from the braking start timing. Assuming this is the case this time, the determination is YES and S
At 65, the latest deceleration GMEAN1 is read from the RAM, and the variation amount Δθ is determined based on it.
The relationship between the deceleration and the vehicle body inclination angle, which is experimentally acquired, is stored in advance in the ROM, and the relationship Δθ is determined using the relationship. Then, in S63, the ground vehicle speed u is calculated using the variation amount Δθ. This completes one execution of this routine.

After that, if T ₁ time elapses while the execution of S61, 64, 65 and 63 is repeated, S6
The determination of 4 is NO, and in S66, it is determined whether or not the antilock control is currently being performed. Since it is assumed that the antilock control is not performed this time, the determination is NO, and the steps from S65 are executed. That is, the variation amount Δθ is calculated based on the deceleration GMEAN1, and the ground vehicle speed u is calculated using the calculated variation amount Δθ.

Next, the braking state in which the antilock control is performed will be described. First, in S61, if it is determined whether or not the brake switch 38 is in the ON state,
Since it is assumed that the vehicle is in a braking state this time, the judgment is Y.
In ES 64, in S64 and S65, the ground vehicle speed u is changed by using the variation amount Δθ based on the deceleration GMEAN1 in the first period (represented by “I” in FIG. 17) from the braking start time until T ₁ time elapses. Is calculated. After that, when T ₁ time has elapsed from the braking start time, the determination in S64 becomes NO, and in S66, it is determined whether or not the antilock control is currently being performed.

Assuming that the antilock control is not yet started immediately after the braking, the determination becomes NO, the steps S65 and thereafter are executed, and the deceleration GM is executed.
The variation amount Δθ is calculated based on EAN1, and the ground vehicle speed u is calculated using it. On the other hand, the antilock control was started before the time T ₁ passed from the braking start time, or was not started when the time T ₁ passed, but thereafter, S61, 64, 66, 65.
When the anti-lock control is started while the execution of steps 63 and 63 is repeated, the determination in S66 is YES, and the process proceeds to steps S67 and thereafter.

In S67, the _second period from the end of the first period to the elapse of T ₂ time (see FIG. 1).
7) (denoted by "II").
If this is the case this time, the determination is YES and S
At 68, the value of the deceleration GMEAN1 at the end timing of the first period is determined as the variation amount Δθ, and thereafter, S6.
In 3, the ground vehicle speed u is calculated using the variation amount Δθ.

After that, S61, 64, 66, 67, 68
And 63 are repeated, but at each execution,
In S68, the final value of the deceleration GMEAN1 in the first period is determined as the fluctuation amount Δθ, and eventually the fluctuation amount Δθ in the second period is fixed to the final value of the deceleration GMEAN1 in the first period. Become.

After that, S61, 64, 66, 67, 68
If the second period ends while the execution of steps 63 and 63 is repeated many times (the period after the second period ends is represented by "III" in FIG. 17), the determination in S67 is NO,
In S69, the latest deceleration GMEAN2 is read from the RAM, and the corresponding variation amount Δθ is determined using the relationship stored in advance in the ROM. Then, in S63, the ground vehicle speed u is calculated using the variation amount Δθ.
Is calculated.

Therefore, in the present embodiment, the detection response of the deceleration to the actual deceleration is improved in the initial stage of braking, so the detection accuracy of the ground vehicle speed u is also improved. In addition to this, it is possible to obtain the effect of improving the accuracy of determining whether antilock control is necessary.
Hereinafter, a specific description will be given.

The judgment of the start of the antilock control is usually made by judging whether or not each wheel speed V has dropped considerably with respect to the ground vehicle speed u. On the other hand, in the conventional device in which the transmitter 62 and the like are mounted rearward in the vehicle, when the vehicle body leans forward due to the brake dive, the direction of the transmitter 62 and the like approaches the vehicle traveling direction, that is, the actual mounting of the transmitter 62 and the like. The angle becomes smaller than the reference angle θ ₀ , and the detected ground vehicle speed u becomes larger than the actual ground vehicle speed. for that reason,
In the conventional device, the tendency that the antilock control is performed more than necessary becomes strong. However, in the present embodiment, the ground vehicle speed u is accurately detected even at the beginning of braking, so that it is not necessary to perform the antilock control more than necessary as in the conventional device, and thus the antilock control is performed. The accuracy of determining whether or not it is necessary is improved.

Further, in the present embodiment, the estimated vehicle speed VSO is ignored in the middle braking period from the time when the estimated vehicle speed VSO starts to increase due to the effect of the antilock control to the time when the estimated vehicle speed VSO starts to decrease substantially following the actual ground vehicle speed. , The deceleration G is fixed to the final value at the beginning of braking. Therefore, the accuracy of acquiring the deceleration G in the middle braking period is improved, and the accuracy of detecting the ground vehicle speed u is also improved.

Furthermore, in the present embodiment, in the latter period of braking when the estimated vehicle speed VSO starts to decrease substantially following the actual vehicle speed due to the effect of the antilock control, a larger number of sample decelerations GSMP at the initial braking stage are obtained. The average value of is defined as the true deceleration G. Therefore, the variation of the true deceleration G is suppressed, and the detection accuracy of the ground vehicle speed u is improved.

As is clear from the above description, in the present embodiment, FIG.
The portion for executing the routine of Fig. 10 constitutes one aspect of the "vehicle speed estimating means 5" in the inventions of claims 1 and 2, and the portion for executing the routine of Fig. 10 of the ground vehicle speed detecting computer 66 is "determination of sample acceleration / deceleration. 11 and 12 of the ground vehicle speed detection computer 66, and steps S61, 64 to 67, 69 of FIG.
The portion for executing the above forms one mode of the "genuine acceleration / deceleration determining means 7", and the respective modes of the vehicle speed estimating means 5, the sample acceleration / deceleration determining means 6 and the genuine acceleration / deceleration determining means 7 cooperate with each other, It constitutes one aspect of the "acceleration / deceleration acquisition means 4" in each of the inventions of claims 1 and 2, and, in the ground vehicle speed detection computer 66, S62, 6 in FIG.
The part that executes 3, 65, 68, 69 constitutes one mode of the "ground vehicle speed determining means 3".

Next explained is a Doppler type ground vehicle speed detecting apparatus which is another embodiment common to the inventions of claims 1 and 2.

In this embodiment, only the ground vehicle speed calculation routine is changed from the above embodiment, and the ROM of the ground vehicle speed detection computer 66 is replaced with the routine shown in FIG. The routine is stored in advance. Therefore, the description of the parts common to the above-described embodiment will be omitted, and only the ground vehicle speed calculation routine of FIG. 14 will be described.

This routine is also similar to the routine of FIG. 13, and the variation amount Δθ is determined according to the rule according to each braking period of the vehicle.
Is calculated. However, unlike the routine of FIG. 13, this routine does not calculate the actual vehicle mounting speed u by acquiring the actual mounting angle θ from the reference angle θ ₀ and the variation Δθ.
The ground vehicle speed u is calculated by ignoring the fluctuation amount Δθ, that is, assuming that the actual mounting angle θ matches the reference angle θ ₀ , and then the variable correction coefficient K is calculated according to the fluctuation amount Δθ. The ground vehicle speed u is corrected by multiplying the ground vehicle speed u.

A detailed description will be given below with reference to FIG.
In S71, 72, 76 to 81, S61 of FIG.
The fluctuation amount Δθ is determined in the same manner as 62, 64-69,
Then, in S73, the value of the correction coefficient K corresponding to the variation amount Δθ is determined. The relationship between the fluctuation amount Δθ and the correction coefficient K, which is obtained experimentally, is stored in advance in the ROM of the ground vehicle speed detection computer 66, and the current value of the correction coefficient K is determined using the relationship. Of. After that, in S74, the ground vehicle speed u ignoring the variation of the mounting angle is calculated based on the reference mounting angle θ ₀ and the present transmission frequency f _T and the reception frequency f _R, and then in S75. The product of the ground vehicle speed u and the current value of the correction coefficient K is calculated as the current ground vehicle speed u.

As is clear from the above description, in the present embodiment, FIG.
The portion for executing the routine of Fig. 10 constitutes one aspect of the "vehicle speed estimating means 5" in the inventions of claims 1 and 2, and the portion for executing the routine of Fig. 10 of the ground vehicle speed detecting computer 66 is "determination of sample acceleration / deceleration. 11 and FIG. 1 of the ground vehicle speed detection computer 66, which constitutes one aspect of the “means 6”.
The routine for executing the routine 2 of FIG. 14 and the portion for executing S71, 76 to 79, 81 in FIG. 14 constitute one mode of the "genuine acceleration / deceleration determining means 7", and the vehicle body estimating means 5, the sample acceleration / deceleration determining means 6
Further, the respective aspects of the true acceleration / deceleration determining means 7 cooperate with each other to configure an aspect of the "acceleration / deceleration obtaining means 4" in the inventions of claims 1 and 2, and the ground vehicle speed detection computer 66 , S72 to 75,7 in FIG.
The part that executes steps 7, 80 and 81 constitutes one mode of the "ground vehicle speed determining means 3".

In the two embodiments described above, the estimated vehicle speed VSO is reduced by the antilock control by determining whether the elapsed time from the braking start time exceeds T ₁ time. Whether or not it has turned to an increasing tendency has been indirectly detected.
It can also be directly detected by determining whether or not the time differential value of the estimated vehicle speed VSO becomes 0 or more.
Further, it is also possible to detect the time when the gradient of the estimated vehicle speed VSO becomes zero before it starts to become gentle and to fix the variation amount Δθ from that time.

Further, in these two embodiments, the estimated vehicle speed VSO substantially follows the actual ground vehicle speed by determining whether the elapsed time from the end time of the first period exceeds T ₂ hours. It was designed to indirectly detect whether or not the vehicle speed has started to decrease.
It can also be directly detected by detecting the time when the time differential value of is changed from positive to negative.

Further, in those embodiments, the variation amount Δθ is fixed after the estimated vehicle speed VSO starts to increase due to the effect of the antilock control. For example, the antilock control is started. You may fix it from time to time. This is because the time differential value of the estimated vehicle speed VSO tends to approach 0 during the period from when the antilock control is started to when the estimated vehicle speed VSO starts to increase.

Further, in these embodiments, the estimated vehicle speed calculation routine is the ROM of the ground vehicle speed detection computer 66.
However, it may be stored in the ROM of the antilock control computer 32.

Further, in those embodiments, during the period in which the estimated vehicle speed VSO decreases substantially following the actual ground vehicle speed due to the effect of the antilock control, the estimated vehicle speed VS is reduced.
Although the sample deceleration GSMP was calculated using O, for example, the sample deceleration GS is calculated using the ground vehicle speed u.
MP can also be calculated.

Next, a Doppler ground vehicle speed detecting device which is an embodiment common to the inventions of claims 1 and 3 will be described.

As shown in FIG. 15, the Doppler type ground vehicle speed detecting apparatus 100 according to the present embodiment is configured to include a transmitting unit 102, a receiving unit 104 and a ground vehicle speed detecting computer 106, as in the previous embodiment. Has been done. The ground vehicle speed detection computer 106 also includes the brake switch 38 and the antilock control device 30 as in the previous embodiment.
However, unlike the previous embodiment, the wheel speed sensor 34 is not connected, and instead, the deceleration sensor 1 that directly detects the deceleration in the longitudinal direction of the vehicle body.
30 is connected. Further, as the ground vehicle speed calculation routine, a routine different from that of the previous embodiment, that is, a routine shown in the flowchart of FIG. 16 is stored in advance.

This routine will be described below, but first, it will be briefly described. This routine sequentially determines the sample deceleration GSMP based on the output signal from the deceleration sensor 130, and determines a plurality of sample decelerations GSM from this time to past times.
Based on the average value of P, the variation amount Δ of the angle of the transmitter 102 or the like
Although θ is estimated and the vehicle speed u to the ground is detected based on the estimated θ, the initial period of one braking (the period in which the leaning state of the vehicle body is transient, that is, the period of 150 ms. Is an aspect of "the initial stage" in the invention of 1), the average value of the past M sample decelerations GSMP (this is an aspect of the "first candidate acceleration / deceleration" in each invention of claims 1 and 3). ) Is the true deceleration G, and in the latter period (a period in which the lean state of the vehicle body is steady. This is one aspect of the "latter period" in the invention of claim 3), the past N (> M). ) The average value of the sample decelerations GSMP (this is one aspect of the "second candidate acceleration / deceleration" in each of the first and third aspects of the invention) is defined as the true deceleration G.

The details will be described below with reference to FIG.
First, in S101, the brake switch 38 is turned on.
It is determined whether or not the state is present, and if not, S102.
In, the average value of the latest N sample decelerations GSMP already stored in the RAM is calculated, and this is set as the true deceleration G of this time. Subsequently, in step S103, the current variation amount Δθ of the angle of the transmission unit 102 and the like is calculated using the relationship stored in advance in the ROM. afterwards,
In S104, the variation amount Δθ and the reference angle θ
_The current ground vehicle speed u is calculated based on ₀ and the current transmission frequency f _T and the reception frequency f _R. This completes one execution of this routine.

On the other hand, the brake switch 38 is O
If it is operated to the N state, the determination in S101 is YES, and in S105, the brake switch 38 is turned on.
It is determined whether or not 150 ms has not elapsed since the state was set. Assuming that this time has not elapsed, the determination becomes YES, and in S106, the average value of the latest M sample decelerations GSMP already stored in the RAM is calculated, and this is the true deceleration G of this time. It is said that Then, it transfers to S103.

After that, S101, 105, 106, 10
150 times after the brake switch 38 is operated in the ON state while the execution of 3 and 104 is repeated many times.
If ms has elapsed, the determination in S106 is NO,
The process proceeds to S102, and this time, the latest N sample decelerations G
The average value of SMP is set as the true deceleration G of this time, and the ground vehicle speed u is calculated based on this.

As is clear from the above description, in the present embodiment, the deceleration sensor 130 constitutes one aspect of the "acceleration / deceleration sensor 8" in the invention of claim 3, and the 16, S101,1
The parts that execute 02, 105, and 106 constitute one mode of the “genuine acceleration / deceleration determining means 9”, and one mode of each of the acceleration / deceleration sensor 8 and the true acceleration / deceleration determining means 9 cooperates with each other. It constitutes one aspect of the "acceleration / deceleration acquisition means 4" in each of the inventions of items 1 and 3, and
Of the ground vehicle speed detection computer 106, S1 of FIG.
The part that executes 03 and 104 constitutes one mode of the "ground vehicle speed determining means 3".

Although some embodiments of the present invention have been described in detail with reference to the drawings, various modifications other than these will be made based on the knowledge of those skilled in the art without departing from the scope of the claims. Of course, the present invention can be implemented in an improved mode.

[Brief description of the drawings]

FIG. 1 is a diagram conceptually showing a configuration of the invention of claim 1;

FIG. 2 is a diagram conceptually showing the structure of the invention of claim 2.

FIG. 3 is a diagram conceptually showing the structure of the invention of claim 3.

FIG. 4 is a diagram conceptually showing a configuration of a Doppler type ground vehicle speed detecting device which is an embodiment of the invention of claim 1.

FIG. 5 is a system diagram conceptually showing an electric system of an antilock control device used together with the Doppler type ground vehicle speed detection device.

FIG. 6 is a system diagram showing the antilock control device.

FIG. 7 is a flowchart showing a ground vehicle speed calculation routine used by the Doppler type ground vehicle speed detection device.

FIG. 8 is a diagram conceptually showing the configuration of a Doppler type ground vehicle speed detection device which is an embodiment common to the inventions of claims 1 and 2.

FIG. 9 is a flowchart showing an estimated vehicle speed VSO calculation routine used by the Doppler type ground vehicle speed detection device.

FIG. 10 is a flowchart showing a sample deceleration GSMP calculation routine used by the Doppler ground vehicle speed detection device.

FIG. 11 is a flowchart showing a deceleration GMEAN1 calculation routine used by the Doppler ground vehicle speed detection device.

FIG. 12 is a flowchart showing a deceleration GMEAN2 calculation routine used by the Doppler type ground vehicle speed detection device.

FIG. 13 is a flowchart showing a ground vehicle speed calculation routine used by the Doppler type ground vehicle speed detection device.

FIG. 14 is a flowchart showing a ground vehicle speed calculation routine used by a Doppler type ground vehicle speed detection device which is another embodiment common to the inventions of claims 1 and 2.

FIG. 15 is a diagram conceptually showing the structure of a Doppler type ground vehicle speed detecting device which is an embodiment common to the inventions of claims 1 and 3.

FIG. 16 is a flowchart showing a ground vehicle speed calculation routine used by the Doppler type ground vehicle speed detection device.

FIG. 17 is a graph showing an example of the relationship between the vehicle speed estimated from the wheel speed and the actual ground vehicle speed in one braking state with anti-lock control.

[Explanation of symbols]

 10,60,100 Doppler type ground vehicle speed detection device 12,62,102 Transmission unit 14,64,104 Reception unit 16,66,106 Ground vehicle speed detection computer 30 Antilock control device 34 Wheel speed sensor 38 Brake switch 40 Brake 130 Decrease Speed sensor

Continuation of the front page (56) Reference JP-A-49-8690 (JP, A) JP-A-63-269064 (JP, A) JP-A-47-7467 (JP, A) JP-A-2-140683 (JP , A) Japanese Unexamined Patent Publication No. 50-18887 (JP, A) Actually developed 62-134068 (JP, U)

Claims (3)

(57) [Claims] 1. A transmitter mounted on a vehicle body for transmitting waves toward a road surface, and a receiver mounted on the vehicle body for receiving waves transmitted from the transmitter and reflected on the road surface. In a Doppler type ground vehicle speed detecting device including a ground vehicle speed determining means for determining a ground vehicle speed, which is a traveling speed of the vehicle body with respect to a road surface, based on a transmission frequency of the transmitter and a reception frequency of the receiver, acceleration / deceleration of the vehicle body. Acceleration / deceleration acquisition means is provided, and the ground vehicle speed determination means includes not only the transmission frequency and the reception frequency but also the acceleration / deceleration acquisition means.
Acceleration / deceleration acquired as a result , the acceleration / deceleration, and the transmitter.
Also, the Doppler type ground vehicle speed detecting device is characterized in that the ground vehicle speed is determined also based on the relationship between the receiving unit and the actual angle with respect to the road surface . 2. Based on the relationship between each wheel speed detected by each wheel speed sensor for each of a plurality of wheels and the ground vehicle speed determined by said ground vehicle speed determining means, each wheel is locked during vehicle braking. The Doppler type ground vehicle speed detection device according to claim 1, wherein the anti-lock control device is provided in an anti-lock control device that controls the brake pressure of each wheel so that the acceleration / deceleration acquisition means (a) uses the plurality of wheel speed sensors. Vehicle speed estimating means for sequentially estimating the vehicle speed from the detected plurality of wheel speeds, and (b) a sample acceleration / deceleration determining means for setting the difference between the current value and the previous value of the estimated vehicle speed as the current sample acceleration / deceleration, ) The sample acceleration / deceleration is sequentially fetched from the sample acceleration / deceleration determining means, and after one braking is started,
In the first period between the start time of the antilock control based on the braking and the time when the estimated vehicle speed starts to increase due to the effect of the antilock control, in the first period, a plurality of times from this time to a plurality of past times are reached. The first candidate acceleration / deceleration based on the sample acceleration / deceleration is set as the true acceleration / deceleration of this time, and in the second period from the end of the first period until the estimated vehicle speed starts to decrease, The true acceleration / deceleration of each time is fixed to the final value in the first period, and in the third period from the end of the second period to the end of the antilock control, from the present time to the past multiple times, A true acceleration / deceleration determining means for determining the second candidate acceleration / deceleration based on a larger number of sample accelerations / decelerations than the first candidate acceleration / deceleration as the true acceleration / deceleration of this time. Doppler ground speed detection device. 3. The acceleration / deceleration acquisition unit sequentially determines (a) an acceleration / deceleration sensor that directly detects the acceleration / deceleration of the vehicle body, and (b) a sample acceleration / deceleration based on an output signal from the acceleration / deceleration sensor. In addition, at the beginning of one braking, the first candidate acceleration / deceleration based on multiple sample acceleration / deceleration from this time to past times is set as the true acceleration / deceleration of this time, and in the latter period, from this time to past times Of the first
The Doppler according to claim 1, further comprising: true acceleration / deceleration determining means for setting a second candidate acceleration / deceleration based on a larger number of sample accelerations / decelerations of candidate accelerations / decelerations as a current true acceleration / deceleration. Type ground vehicle speed detection device.