JPH11160429A - Ultrasonic sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable correct detection without overlooking an object existing in a different direction and approximately at an equal distance, by providing a storing means, etc., which stores times successively when an instantaneous sound pressure of a reflected wave received by a wave receiver exceeds a specified threshold value. SOLUTION: A first storing means 42 stores times when an instantaneous sound pressure of a reflected wave received by a first wave receiver 30a, as a first series of times successively. A second storing means 43 stores times when the instantaneous sound pressure of a reflected wave received by a second wave receiver 30b exceeds a specified threshold value, as a second series times successively. A time-series time-difference storing means 44 stores the time differences between a series of the first and the second times, and a shift judging unit 45 judges whether or not there is any point of time having shifted by a specified value or more determined beforehand. If the shift judging unit 45 judges that there is a point of time having shifted by a specified value or more determined beforehand, a recomputing means 46 computes the direction detecting a new objective, on the basis of this shift value having shifted by the specified value or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic sensor device for detecting an object to be detected by utilizing the fact that an ultrasonic pulse wave is reflected back from the object to be detected.

[0002]

2. Description of the Related Art An ultrasonic sensor device for detecting the distance and direction to an object by utilizing the fact that an ultrasonic pulse wave is reflected from an object to be detected is known. . Such a conventional ultrasonic sensor device will be described with reference to FIGS. FIG. 5 is a block diagram showing an ultrasonic sensor device, FIG. 6 is a circuit diagram showing a detection circuit and a waveform shaping circuit of the ultrasonic sensor device, and FIG. 7 shows operations of the detection circuit and the waveform shaping circuit of the ultrasonic sensor device. FIG. 8 is an explanatory diagram showing an outline of signal processing of the ultrasonic sensor device when only one detection target is present in the detection area, and FIG. 9 is a diagram illustrating two detection targets being positions of the ultrasonic sensor device. FIG. 9 is an explanatory diagram illustrating an outline of signal processing of the ultrasonic sensor device when the directions are different, although they are located at substantially equal distances from each other. FIG. 10 is a plan view showing the positional relationship between the ultrasonic sensor device and the detection target. FIG. 10A shows a case where only one detection target exists in the detection area, and FIG. This shows a case where the two detection targets are located at substantially the same distance from the ultrasonic sensor device, but in different directions.

As shown in FIG. 5, a conventional ultrasonic sensor device 1 includes a transmitting unit 2, a receiving unit 3, a signal processing unit 4, a control unit 5, and a display output unit 6. The transmitting unit 2 intermittently radiates an ultrasonic pulse wave of a predetermined frequency to a detection area. The transmitting unit 2 includes a periodic oscillation circuit 20, a transmitting gate circuit 21, a driving circuit 22, and a transmitting oscillator 23. The periodic oscillation circuit 20 generates and outputs a synchronization pulse for setting the timing of emitting an ultrasonic pulse wave. The transmission gate circuit 21 sets the pulse width of the ultrasonic pulse wave. The drive circuit 22 power-amplifies the ultrasonic pulse wave output from the transmission gate circuit 21 to a level at which the transmission oscillator 23 can be driven, and outputs the amplified power to the transmission oscillator 23. The transmitting oscillator 23 oscillates based on the output of the drive circuit 22 and sends a predetermined frequency (normally 40 KHz) to the detection area.
) To emit an ultrasonic pulse wave having a predetermined time width.

The wave receiving section 3 includes a wave receiver 30a corresponding to a first wave receiver and a wave receiver 30b corresponding to a second wave receiver. The receiver 30a and the receiver 30b are configured in exactly the same manner, and the receiver 31a is a receiver 31b.
The amplifier 32a corresponds to the amplifier 32b, the detection circuit 33a corresponds to the detection circuit 33b, and the waveform shaping circuit 34a corresponds to the waveform shaping circuit 34b. Note that the wave receiving oscillator 31a and the wave receiving oscillator 31b are arranged at a predetermined interval d.

[0005] reception transducer 31a serves to reception of the ultrasonic pulse wave reflected back from the object to be detected M _1, sequentially converts the sound pressure of the ultrasonic pulse wave to the reception to the voltage change Then, the signal is output to the amplifier 32a. Amplifier 32
a amplifies the voltage signal of the ultrasonic frequency output from the receiving transducer 31a and outputs the output voltage V _a as shown in FIG.
Is output to the detection circuit 33a.

[0006] detection circuit 33a, in order to obtain a voltage signal proportional to the sound pressure level of reception of the reception transducers 31a, envelope connecting the mountain portion of the voltage signal V _a of the output ultrasonic wave frequency of the amplifier 32a Lines are configured to obtain, for example, FIG.
And outputs an output voltage _Va1 as shown in FIG. 7B to the waveform shaping circuit 34a. Waveform shaping circuit 34a compares the output voltage V _a1 from the reference voltage V _th and the detection circuit 33a as a predetermined threshold value, the period is V _a1> V _th is configured to output a High For example, the output voltage V _a2 is configured as a waveform shaping circuit 34a shown in FIG.
Is output to the signal processing unit 4.

[0007] reception transducer 31b is adapted to reception of the ultrasonic pulse wave reflected back from the object to be detected M _1, sequentially converts the sound pressure of the ultrasonic pulse wave to the reception to the voltage change Then, the signal is output to the amplifier 32b. Amplifier 32
b amplifies the voltage signal of the ultrasonic frequency output from the receiving transducer 31b, and outputs the output voltage V _b as shown in FIG.
To the detection circuit 33b.

[0008] The detection circuit 33b is an envelope connecting the peaks of the ultrasonic frequency voltage signal _Vb output from the amplifier 32b in order to obtain a voltage signal proportional to the sound pressure level received by the reception transducer 31b. Lines are configured to obtain, for example, FIG.
And outputs an output voltage _Vb1 as shown in FIG. 7B to the waveform shaping circuit 34b. Waveform shaping circuit 34b compares the output voltage V _b1 from the reference voltage V _th and the detection circuit 33b as a predetermined threshold value, the period is V _b1> V _th is configured to output a High For example, the output voltage V _b2 is configured as a waveform shaping circuit 34b shown in FIG.
Is output to the signal processing unit 4.

By the way, since the reception transducers 31a and reception transducer 31b is disposed at a predetermined distance d, the detection object M ₁ as shown in FIG. 10 (a) Ultra If there is _{one at} the position of the distance L _{1 in} the direction of the azimuth angle θ 1 from the acoustic wave sensor device 1, as shown in FIG. 8, detection of the ultrasonic pulse wave transmitted from the transmitting oscillator 23 at time t ₀ is detected. Object M
Reflected wave R _m1 from ₁ reception transducer 31 is first in time t _a1
a, and then received by the receiving oscillator 31b at time t _b1 .

Here, the time t₀And time t_a1Time difference with
T_aAt time t₀And time t_b1The time difference between_bAt time t_a1
And time t_b1The time difference between₁, Sound velocity V_S, T = (T_a
+ T _b) / 2, the detection pair from the ultrasonic sensor device 1
Elephant M₁Distance L to₁Is L ₁= V_S・ As T / 2
The detection target M from the ultrasonic sensor device 1₁Towards
Angle θ₁Is θ₁= Sin^-1(T₁・ V_S/ D)
Can be

The signal processing section 4 includes a distance detection circuit 40 and an azimuth detection circuit 41 which operate under the instruction of the control section 5. Therefore, the distance detection circuit 40, described above, and the time difference T _a between time t ₀ and time t _a1, measures the time difference T _b between time t ₀ and time t _b1, the time difference T _a time difference T _b From the average value T and the sound velocity V _S , the distance L ₁ from the ultrasonic sensor device 1 to the detection target M ₁ is calculated as L ₁ =
Is calculated as V _S · T / 2. The azimuth detection circuit 41
The time difference T ₁ between the time t _a1 and the time t _b1 is measured, and the azimuth θ ₁ from the ultrasonic sensor device 1 to the detection target M ₁ is calculated as θ ₁
= Sin ^-1 (T ₁ · V _S / d).

The control unit 5 includes a microcomputer, and controls the entire ultrasonic sensor device 1. The display output unit 6 performs the distance L ₁ and the azimuth θ from the ultrasonic sensor device 1 to the detection target M ₁ based on the instruction of the control unit 5.
₁ and are displayed.

[0013]

However, in the above-described ultrasonic sensor device, as shown in FIG. 10B, two detection objects M _{1 and} M ₂ are connected to the ultrasonic sensor device 1. , The detection target M ₁ is located at a distance L _{1 in} the direction of the azimuth angle θ ₁ from the ultrasonic sensor device, and the detection target M ₂ is in the direction of the azimuth angle θ ₂ from the ultrasonic sensor device. in the distance in the position of L _2, if the distance L ₁ and the distance L ₂ is different only slightly, as shown in FIG. 9, an ultrasonic pulse wave transmitted from the transmitting transducer 23 at time t ₀ reflected wave R _m1 from the detection object M ₁ wave is received wave to wave receiving vibrator 31a is first in time t _a1, then, it is received wave to wave receiving transducer 31b at time t _b1. However, since the distance L ₁ and the distance L ₂ slightly different only from the reflected wave while the R _m1 is not sufficiently attenuated, reception transducers 31a subsequently reflected wave R _{m @ 2} from the detection object M _2, 31b Is received.

Therefore, the waveform shaping circuits 34a and 34b
9 (c) and 9 (e) respectively show the output waveforms of FIG.
As a result, a series of pulses is generated, and two detections are made in the detection area.
Knowledge object M_1,M_TwoDespite the presence of
The sensor device 1 includes the detection target M ₁Distance L to₁And azimuth
θ₁And the detection target M_TwoOverlook the existence of
There was a problem that it might be done.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has as its object to provide a plurality of detection objects, each of which has a distance from the ultrasonic sensor device. If the azimuths to the respective detection targets are sufficiently different, although they differ only slightly, an excellent ultrasonic wave that can correctly detect the presence of a plurality of detection targets without overlooking either detection target. It is to provide a sensor device.

[0016]

According to the present invention, in order to solve the above-mentioned problems, an ultrasonic pulse wave is intermittently transmitted from a transmitter to a detection area space. Then, the reflected wave that the ultrasonic pulse wave reflects from the detection target and returns is received by the first receiver and the second receiver whose distances are known, and transmitted. The distance to the detection target is calculated based on the time delay of the reflected wave received with respect to the waved ultrasonic pulse wave, and the reflected wave received by the first receiver and the second wave are received. In the ultrasonic sensor device which calculates the direction based on the time delay with respect to the reflected wave received by the wave receiver, the instantaneous sound pressure of the reflected wave received by the first wave receiver is set to a predetermined threshold. First storage means for sequentially storing the times exceeding the time as a first series of times,
A second storage means for sequentially storing a time at which the instantaneous sound pressure of the reflected wave received by the second receiver exceeds a predetermined threshold value as a second series of times; A time-series time difference storage means for obtaining and storing a time difference from the second series of times in a time-series manner, and a series of time differences stored in the time-series time difference storage means in a time-series manner; A shift determining unit that determines whether there is a time point when the shift is performed; and, when the shift determining unit determines that there is a time point when the shift value is equal to or more than a predetermined value, the shift value is shifted to a predetermined value or more. Re-calculating means for calculating the direction of a new detection target based on the calculation.

According to the second aspect of the present invention, when the shift judging section judges that there is a point in time when the shift is made to a predetermined value or more, a new detection is performed based on the time when the shift is made to the predetermined value or more. The function to calculate the distance to the object is
It is characterized in that it is added to the recalculation means.

According to the third aspect of the present invention, when the shift judging section judges that there is no point in time when the shift is made to a predetermined value or more, the average of all the time differences stored in the time-series time difference storage means. The direction of the detection target is calculated based on the value.

In the invention according to claim 4, when the shift determining unit determines that there is a point in time when the shift has been performed to a predetermined value or more, the time difference stored in the time-series time difference storage unit is determined. With the average value of the time difference before the time point and the average value of the time difference after the time point among the time differences stored in the time-series time difference storage means, the direction of each detection target is calculated. It is characterized by having done.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an ultrasonic sensor device according to the present invention will be described in detail with reference to FIGS. FIG. 1 is a block diagram showing an ultrasonic sensor device, FIG. 2 is a circuit diagram showing a detection circuit and a waveform shaping circuit of the ultrasonic sensor device, and FIG. 3 shows operations of the detection circuit and the waveform shaping circuit of the ultrasonic sensor device. FIG. 4 is a timing chart for explaining a first series of times and a second series of times. FIG.
In FIG. 2 and FIG. 2, the same parts as those of the ultrasonic sensor device described in the related art are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 1, the ultrasonic sensor 1
Includes a transmitting unit 2, a receiving unit 3, a signal processing unit 4, a control unit 5, and a display output unit 6. The ultrasonic sensor device 1 shown in FIG. 1 is different from the conventional ultrasonic sensor device in that it has the following features.

That is, the first feature is that the wave receiving
In the part 3, the receiver 30a corresponding to the first receiver
A detection circuit 33a and a receiver 30 corresponding to a second receiver;
b from the detection circuit 33b.₀To
Then, as shown in FIG.
Resistor R on cathode₀Only connect the amplifier
32a (32b) as shown in FIG.
Pressure V_a(V_b) Is half-wave rectified as shown in FIG.
Output voltage V_a1(V_b1) To convert this output voltage
V_a1(V_b1) Is output to the waveform shaping circuit 34a (34b).
In the waveform shaping circuit 34a (34b),
Reference voltage V as threshold_thAnd the detection circuit 33a (33
output voltage V from b)_a1(V_b1) And V_a1>
V_thOr V_b1> V_thHigh is output during the period
The output voltage V as shown in FIG._a2(V_b2)
Is output to the signal processing unit 4 so that V_a1> V_this there
Or V _b1> V_thAt the moment t_1,t_2,t_3,...
This is a configuration that can be grasped by the signal processing unit 4.

The second feature is that the signal processing unit 4 includes, in addition to the distance detection circuit 40 and the azimuth detection circuit 41, a storage unit 42 corresponding to first storage means, , A storage unit 44 corresponding to a time-series time difference storage unit, a shift determination unit 45, and a recalculation instruction unit 46 corresponding to a recalculation unit.

The storage unit 42 stores a series of times when the instantaneous sound pressure of the reflected wave received by the receiver 30a exceeds the reference voltage _Vth corresponding to a predetermined threshold, that is, the time t in FIG.
_a1, t _a2, ... t _an are stored. The storage unit 43 stores the receiver 3
A series of times when the instantaneous sound pressure of the reflected wave received at 0b exceeds the reference voltage _Vth corresponding to the predetermined threshold, that is, FIG.
Store the times t _b1, t _b2, ... T _bn in (f). Then, the storage unit 44, the time difference T _1, T _2, stores ... T _n. The time difference T ₁ is given as T ₁ = t _a1 −t _b1 , the time difference T ₂ is given as T ₂ = t _a2 −t _b2 ,..., And the time difference T _n is given as T _n = t _an −t _bn. It is.

The shift judging section 45 has a predetermined
Value T₀For example, T₀= 5.0 μsec,
For example, the time difference T_1,T_2,... T₆Is T₁= 10.0μse
c, T_Two= 10.1μsec, T_Three= 10.0μsec, T_Four= -8.0
μsec, T_Five= -8.2μsec, T₆= -8.1μsec
Then the time difference T_ThreeTime difference T from_FourShift to
Value T₃₄Is T₃₄= | T_Three-T_Four| = 18.0μsec
And T₃₄> T₀Therefore, the ultrasonic sensor device 1
The reflected wave to be waved is at time t_a3And time t_a4Halfway between
And the detection target M₁Reflected wave R from_m1From the detection target M
_TwoReflected wave R from _m2Was replaced by
Eye detection target M_TwoIs determined to exist.

When the shift judging section 45 judges the presence of the _second detection object M ₂ , the recalculation instructing section 46 determines the shift value T when the _second detection object M ₂ is judged to be present.
_The time difference T ₄ used when calculating ₃₄ , ie, -8.0 μsec
Is output to the azimuth angle detection circuit 41. Then, the azimuth detection circuit 41 calculates the azimuth θ of the _second detection target M2.
₂ using the time difference T ₄ , θ ₂ = sin ⁻¹ (T ₄ · V _S
/ D).

The control section 5 includes a microcomputer.
And controls the entire ultrasonic sensor device 1.
The separation detection circuit 40 detects the time t₀And time t_a1Time difference T with_a
And time t₀And time t_b1Time difference T with_bAnd based on the time
Difference T_aAnd time difference T_bTo obtain the average value T
T and sound velocity V_SFrom, L₁= V_S・ Calculate as T / 2
Object M from the ultrasonic sensor device 1₁Distance L to
₁And the azimuth detection circuit 41 calculates the time t_a1And time t_b1With
Time difference T₁Based on θ₁= Sin^-1(T₁・ V _S/ D)
From the ultrasonic sensor device 1 calculated as₁
Azimuth θ to₁And the azimuth angle detection circuit 41 calculates the time difference T_Four
And θ_Two= Sin^-1(T_Four・ V_S/ D)
From the detected ultrasonic sensor device 1 to the detection target M_TwoAzimuth to
θ_TwoAre displayed on the display output unit 6.

Therefore, in the ultrasonic sensor device 1 shown in FIG. 1 as described above, a plurality of detection objects exist in the detection area, and the ultrasonic sensor device 1 of each detection object exists.
Even if the distance from is slightly different, if the azimuth of each detection target is sufficiently different,
The presence of a plurality of detection targets can be correctly detected without overlooking each detection target.

It should be noted that the shift judging section 45 records the information by itself.
A predetermined value T stored in advance ₀(Eg T₀= 5.
0 μsec) and the time difference T stored in the storage unit 44_1,T_2,…
T_nFor example, based on the detection
Elephant M₁To another detection target M at a distance substantially equal to the distance to
_TwoIf it is determined that does not exist,
All stored time differences T_1,T_2,... T_nThe average value τ of_{1, n}
That is, τ_{1, n}= ΣT _n/ N to the azimuth angle detection circuit 41
The first time difference T₁Azimuth using only
Angle θ₁Azimuth angle θ, which is much more accurate than when calculating
₁May be obtained.

Further, the shift determining section 45 records the information by itself.
A predetermined value T stored in advance ₀(Eg T₀= 5.
0 μsec) and the time difference T stored in the storage unit 44_1,T_2,…
T_nFor example, based on the detection
Elephant M₁To another detection target M at a distance substantially equal to the distance to
_TwoIf it is determined that there exists a shift determination unit 4
5 is a predetermined value T set in advance₀(Eg T₀= 5.0 μse
c) is determined to be shifted beyond the time difference T_iOr
Time difference T_{i + 1}Shift value T toward_{i, i + 1}Was
Then, the i time differences T stored in the storage unit 44_1,T_2,
... T_iThe average value τ of_{1, i}That is, τ_{1, i}= ΣT_i/ I and
Ni time differences T stored in the storage unit 44_{i + 1,}T_{i + 2,}
... T_nThe average value τ of_{i + 1, n}That is, τ_{i + 1, n}= ΣT_i/
(Ni) to the azimuth detection circuit 41.
And the time difference T₁And time difference T_{i + 1}Azimuth θ using only
₁And azimuth θ_TwoIs much more accurate than when
High azimuth θ₁And azimuth θ_TwoGood to get
No.

The shift judging section 45 stores a predetermined value T ₀ (for example, T ₀ = 5.0 μsec) and a storage section 44.
Time difference T ₁ that is stored _in, T _2, ... based on the T _n, for example, the shift value T ₃₄ from the time difference T ₃ toward the time difference T ₄
Is T ₃₄ > T ₀ , the ultrasonic sensor device 1
If than is other detection subject M ₂ substantially equal to the distance between the distance to the detection object M ₁ is determined to be present from the reflected wave reception to the ultrasonic sensor device 1 the time t _a3 and t in the intermediate time detection subject's because it was interchanged from the reflected wave R _m1 to the reflected wave R _{m @ 2} from the detection object M ₂ from M ₁ and _a4, to the detection object M ₁ from the ultrasonic sensor device 1 a long the a distance of what than L ₁ is more of a distance L ₂ to the sense target M ₂ is a slight, transmitting transducer 23
From based on the time of an intermediate point of the foregoing the time t ₀ after the transmission of an ultrasound pulse waves, so as to accurately calculates the distance L ₂ from the ultrasonic sensor device 1 to the detection target M _2, the detection target the distance L ₁ and the azimuth angle theta ₁ to the object M _1, the distance L ₂ and the azimuth angle theta ₂ and a display output unit 6 to sense target M ₂ may be displayed, respectively.

[0032]

According to the first aspect of the present invention, even when a plurality of detection objects are present and the distances between the detection objects and the ultrasonic sensor device are slightly different, each detection object is detected. If the azimuths of the objects are sufficiently different,
There is an effect that an excellent ultrasonic sensor device that can correctly detect the distance to the plurality of detection objects and the respective directions without missing each detection object can be provided.

According to the second aspect of the present invention, in addition to the effect of the first aspect, the distance to the previously detected object is further reduced by the distance to the previously detected object. Instead, an advantage is provided in that an excellent ultrasonic sensor device that can accurately obtain a distance to a detection target detected later can be provided.

According to the third aspect of the present invention, in addition to the effects of the first or second aspect of the present invention, it is possible to obtain a highly accurate direction when one detection target exists in the detection area. There is an effect that an excellent ultrasonic sensor device can be provided.

According to the fourth aspect of the present invention, in addition to the effects of the first or second aspect of the present invention, when a plurality of detection objects are present in the detection area, it is possible to obtain the respective directions of high accuracy. And an excellent ultrasonic sensor device can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an ultrasonic sensor device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a detection circuit and a waveform shaping circuit of the ultrasonic sensor device.

FIG. 3 is an explanatory diagram showing operations of a detection circuit and a waveform shaping circuit of the ultrasonic sensor device.

FIG. 4 is a timing chart illustrating a first series of times and a second series of times of the ultrasonic sensor device.

FIG. 5 is a block diagram showing a conventional ultrasonic sensor device.

FIG. 6 is a circuit diagram showing a detection circuit and a waveform shaping circuit of the ultrasonic sensor device.

FIG. 7 is an explanatory diagram showing operations of a detection circuit and a waveform shaping circuit of the ultrasonic sensor device.

FIG. 8 is an explanatory diagram showing an outline of signal processing of the ultrasonic sensor device when only one detection target exists in the detection area.

FIG. 9 is an explanatory diagram showing an outline of signal processing of the ultrasonic sensor device when two detection targets are located at substantially equal distances from the position of the ultrasonic sensor device but in different directions.

FIG. 10 is a plan view showing a positional relationship between the ultrasonic sensor device and a detection target.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Ultrasonic sensor device 2 Transmitter 3a 1st receiver 3b 2nd receiver 42 1st storage means 43 2nd storage means 44 Time series time difference storage means 45 Shift judgment part 46 Recalculation means d mutual distance M ₁ detection subject M ₂ sense target R _m1 reflected wave R _{m @ 2} reflected wave V _th predetermined threshold

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Goro Oda 1048 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Works, Ltd.

Claims (4)

[Claims] 1. An ultrasonic pulse wave is intermittently transmitted from a transmitter to a detection area space, and the ultrasonic pulse wave is reflected from a detection target and returns as reflected waves. Distance to a detection target based on a time delay of a reflected wave received by a known first receiver and a second receiver and received with respect to a transmitted ultrasonic pulse wave Ultrasonic sensor device that calculates the direction based on the time delay between the reflected wave received by the first receiver and the reflected wave received by the second receiver , A first storage means for sequentially storing a time at which the instantaneous sound pressure of a reflected wave received by the first receiver exceeds a predetermined threshold value as a first series of times, and a second receiver Are stored sequentially as a second series of times at which the instantaneous sound pressure of the reflected wave received at Second storage means; time-series time difference storage means for obtaining and storing a time difference between the first series of times and the second series of times in a time-series manner; A shift determining unit that determines whether or not there is a point in time that is shifted to a predetermined value or more in a series of time differences stored in a series; and a time when the shift determining unit shifts to or more than a predetermined value. And a recalculating means for calculating the direction of a new detection target based on the shift value shifted to a predetermined value or more. 2. A function of calculating a distance to a new detection target based on the time when the shift has been shifted to a predetermined value or more when the shift determination unit determines that there is a time point when the shift has been made to a predetermined value or more. 2. The ultrasonic sensor device according to claim 1, wherein the following is added to said recalculation means. 3. The direction of the detection target is calculated using the average value of all time differences stored in the time-series time difference storage means, when the shift determination unit determines that there is no time point at which the shift is made to a predetermined value or more. The ultrasonic sensor device according to claim 1, wherein the ultrasonic sensor device performs the operation. 4. When the shift determining unit determines that there is a point in time when the shift is performed to a predetermined value or more, an average of the time differences before the time in the time differences stored in the time-series time difference storage means. The direction of each detection target is calculated using a value and an average value of a time difference after the time point among the time differences stored in the time-series time difference storage means. Or the ultrasonic sensor device according to 2.