JP3018837B2 - Moving object position detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving object position detecting apparatus, and more particularly, to a receiver installed at two points on a moving object and a receiver on the ground side.
The present invention relates to a moving object position detection device that detects a distance from a transmitter installed at a point and detects a moving object position within predetermined coordinates based on the distance data.

[0002]

2. Description of the Related Art Conventionally, transmitters are installed at two points on the ground, and receivers are installed at two points on a moving body, and the distance between the transmitter and the receiver is detected to detect the position of the moving body. An apparatus for performing the above is known. For example, Japanese Patent Laying-Open No. 1-231808 discloses an apparatus using an ultrasonic oscillator and an ultrasonic receiver as these transmitters and receivers.

The apparatus disclosed in the above publication measures two transmissions for each receiver by measuring the time required for an ultrasonic wave emitted from a transmitter installed on the ground to reach a receiver on the mobile body side. Detects distance to aircraft. For this reason,
If coordinates are previously set on the ground based on the installation positions of the two transmitters, the position on the coordinates is determined for each receiver. If the coordinates are determined for each of the receivers installed at two points on the moving body, the angle of the moving body with respect to the coordinates is also determined.

As described above, according to the moving body position detecting device disclosed in the above publication, the position of the moving body with respect to the coordinates set on the ground and the traveling direction can be detected. , Or an autopilot.

[0005]

However, when detecting the distance between the transmitter and the receiver based on the time required for the ultrasonic wave emitted from the transmitter to reach the receiver, if any obstacle exists between the two. A situation occurs in which the distance cannot be measured accurately. If there is an obstacle between the transmitter and the receiver, the receiver receives an indirect wave reflected by some object, that is, an ultrasonic wave that has propagated along a roundabout path, and the actual transmitter / receiver This is because an unduly long propagation time is detected for the distance.

The above-mentioned conventional device does not have any means for coping with such a situation, and is directly affected by an obstacle between a terrestrial transmitter and a mobile receiver. Had the problem that

The present invention has been made in view of the above points, and calculates a distance between a transmitter and a distance between receivers whose distance is known in advance based on the detected distance data between the transmitter and the receiver. It is another object of the present invention to provide a moving object position detecting device that can solve the above-described problem by adopting distance data only when the value is appropriate.

[0008]

FIG. 1 is a block diagram showing the principle of a moving object position detecting apparatus which achieves the above object. That is, the above-mentioned object is achieved by two transmitters 1r and 11l spaced apart from each other as shown in FIG. 1, two receivers 2R and 2L spaced apart from each other, and the two transmitters 1r , 1
1 or a moving body equipped with one of the two receivers 2R and 2L, a reference object equipped with the other, and a transmitter 1r,
Distance detecting means 3 for detecting the distance between 1l and each of the receivers 2R and 2L; and position calculating means 4 for calculating the relative position between the reference object and the moving body based on the distance data detected by the distance detecting means 3. The distance between the two receivers 1r and 1l whose distances are known and the two transmitters 2R and 2L are known based on the distance data detected by the distance detecting means 3. A known distance calculating means for calculating at least one of the distances;
This is achieved by a moving object position detecting device including a correctness / incorrectness determining means 6 for determining whether the detection data of the distance detecting means 3 is correct or not by comparing the calculation result of the above with known distance data.

[0009]

In the moving object position detecting device according to the present invention, when signals emitted from the transmitters 1r and 11 reach the receivers 2R and 2L, respectively, the distance detecting means 3 emits the signal from the transmitter 1r. The propagation time until the received signal reaches the receivers 2R and 2L and the propagation time until the signal emitted from the transmitter 11 reaches the receivers 2R and 2L are measured.

[0010] The distance detecting means 3 determines the transmitter 1r and the receivers 2R, 2L based on the propagation time measured in this way and the propagation speed of the signal generated by the transmitters 1r, 11. And the distance between the transmitter 11 and the receivers 2R and 2L are calculated.

The position calculating means 4 presets one of the two transmitters 1r, 11 and one of the two receivers 2R, 2L as a reference based on the calculated four distance data. The position on the other coordinate and the inclination with respect to the coordinate axis are calculated. Thereby, the relative position of the moving object with respect to the reference object is detected.

On the other hand, the known distance calculating means 5 calculates the distance based on the four distance data detected by the distance detecting means 3.
The distance w between the transmitters 1r, 11 and the receivers 2R, 2
At least one of the distances L between L is calculated back. In this case, if proper distance measurement is performed without any obstacle between the transmitters 1r and 1l, the back calculation value is substantially equal to the known distance data, and the distance data is affected by obstacles and the like. If a large erroneous detection is made, the back calculation is calculated as a value that is significantly different from the known distance data.

Therefore, by comparing the calculation result of the known distance calculation means 5 with the known distance data in the correctness judgment means 6, whether or not the distance data detected by the distance detection means 3 is an appropriate value is determined. Can be determined, and the influence of an obstacle or the like can be eliminated.

[0014]

FIG. 2 is an overall view showing the structure of a moving object position detecting apparatus 10 according to an embodiment of the present invention. The moving object position detecting device 10 according to the present embodiment is provided as a device for guiding the vehicle 11 to the garage 12.

Here, FIG. 2 shows that the vehicle 11
This shows a state where the rear is turned rightward. Ultrasonic oscillators 13R and 13L corresponding to the above-mentioned receivers 2R and 2L are disposed at the rear left and right corners of the vehicle 11. The ultrasonic oscillators 13R and 13L are provided with, for example, PZ
A T (lead zirconate titanate) element or the like is joined to detect ultrasonic vibrations propagating in the air and generate a voltage signal having the same cycle as the vibrations. Here, these ultrasonic oscillators 13R and 13L are arranged with a predetermined distance w between each other.

These ultrasonic oscillators 13R and 13L are both electrically connected to a control device 14. The control device 14 includes the distance detecting means 3, the position calculating means 4,
This is a main part of the apparatus of the present embodiment for realizing the known distance calculation means 5 and the right / wrong judgment means 6. Here, in addition to the above-described ultrasonic oscillators 13R and 13L, the control device 14 of the present embodiment includes:
An electromagnetic wave receiver 15 for detecting an electromagnetic wave of a specific frequency is connected. Therefore, when the electromagnetic wave to be detected is propagated in the air, it is possible to appropriately detect the generation time.

On both sides of the entrance of the garage 12, markers 16r and 16l corresponding to the transmitters 1r and 11 described above are provided.
It is installed at a distance W equal to the width of the garage 12. These markers 16r and 16l are connected to the signal generator 17, convert the voltage signals supplied from the signal generator 17 into ultrasonic waves, and emit the ultrasonic signals toward the front of the garage 12.

Here, an electromagnetic wave transmitter 18 for generating an electromagnetic wave of a predetermined frequency is connected to the signal generator 17 of the present embodiment in addition to the markers 16r and 16l.
The electromagnetic wave transmitter 18 is also used for the markers 16r, 16r.
As in the case of 1, the electromagnetic wave is generated at an appropriate time according to the instruction of the signal generator 17.

Hereinafter, the principle of detecting the distances Rr, Lr, Rl, Ll between the markers 16r, 16l and the ultrasonic receiving oscillators 13R, 13L shown in FIG. 2 using the above-mentioned ultrasonic and electromagnetic wave signals will be described.

FIG. 3 shows the distances Rr, Lr,
FIG. 4 is a time chart showing states of ultrasonic signals and electromagnetic wave signals transmitted / received between markers 16r and 16l, electromagnetic wave transmitter 18, ultrasonic oscillators 13R and 13L, and electromagnetic wave receiver 15 for detecting Rl and Ll. .

As shown in FIGS. 3A, 3B and 3C, the electromagnetic wave transmitter 18 and the markers 16r, 1
From 61, an electromagnetic wave signal and one ultrasonic signal are transmitted simultaneously. In this case, the electromagnetic wave transmitter 18 can transmit the r signal and the l signal while distinguishing the r signal and the l signal based on the frequency, the duration, and the like. When the electromagnetic wave is emitted in synchronization with the marker 16r, the r signal is output. When an electromagnetic wave is emitted synchronously, an l signal is generated.

By the way, as shown in FIGS. 3A and 3B, when the r signal of the electromagnetic wave transmitter 18 and the ultrasonic signal of the marker 16r are emitted simultaneously at time t ₀ , the propagation of both signals Due to the speed difference, there is a difference in the time at which these signals arrive at the vehicle 11.

That is, r having a propagation speed equal to the speed of light
The signal arrives at the electromagnetic wave receiver 15 almost at the same time as being emitted from the electromagnetic wave transmitter 18, and the time can be regarded as t ₀ as shown in FIG. 3 (D). On the other hand, the marker 16
The ultrasonic signal that emitted r propagates in the air at the speed of sound, and reaches each of the ultrasonic oscillators 13R and 13L after a propagation time corresponding to the distance from the marker 16r.

Accordingly, when Rr is longer than Lr as shown in FIG. 2, at time t ₁ when the ultrasonic oscillator 13L receives the ultrasonic signal as shown in FIGS. 3 (F) and 3 (H). late, ultrasonic generator 13R will receive the signal at time t _2.

The time required from the reception of the electromagnetic wave by the electromagnetic wave receiver 15 to the reception of the ultrasonic signal by the ultrasonic oscillators 13R and 13L, that is, the propagation times "t ₂ -t ₀ " and "t ₂ -t ₀ " of the ultrasonic signal. “t ₁ −t ₀ ” has a meaning as a characteristic value indicating a distance between the marker 16r and the ultrasonic oscillators 13R and 13L.

In the present embodiment, the counters C _R and C _L for measuring the propagation time are provided in the control device 14 to detect the propagation time. Then, Figure 3 the value of the counter C _R immediately after receiving the r signal as described above
As a count value C _Rr to the distance Rr (E), the addition recognizes the value of the counter C _L as a count value C _Lr for the distance Lr as shown in FIG. 3 (G).

Similarly, as shown in FIGS. 3A and 3C, when the electromagnetic wave transmitter 18 and the marker 16l emit an l signal and an ultrasonic signal at time t ₃ , respectively, the electromagnetic wave receiver 15 After detecting the l signal, each ultrasonic oscillator 13
The time “t ₄ −” until the ultrasonic signal reaches R, 13L.
When t ₃ ”and“ t ₅ −t ₃ ”are measured, the weighed value is 16 l and the distances Rl, L between the ultrasonic oscillators 13R, 13L.
l.

Therefore, in the present embodiment, the values counted by the counters C _R and C _L immediately after receiving the 1 signal are respectively used as the count values C _R1 and C _L1 corresponding to the distance Rl.
It is to be recognized as. As a result, the counter C
_R, easily marker 16 by monitoring the value of C _L
r, 16l and distance R between ultrasonic oscillators 13R, 13L
r, Lr, Rl, Ll can be detected.

By the way, assuming that the coordinates are set in advance on the ground based on the positions of the markers 16r and 16l,
Once the distances Rr and Rl are determined, the coordinates of the ultrasonic oscillator 13R are determined. Similarly, if the distances Lr and Ll are determined, the position of the ultrasonic oscillator 13L is determined. That is, when the distances Rr, Lr, Rl, and Ll can be detected as described above, the coordinates can be specified for two points on the vehicle 11.

If the coordinates of two points on the vehicle 11 can be specified, the attitude angle of the vehicle 11 with respect to the coordinate axis can be specified together with the position of the vehicle 11. In particular,
For example, as shown in FIG. 4, when the x-axis is set in the width direction of the garage 12 and the y-axis is set in the depth direction, the coordinates (X, Y) of the center of the rear wheel axis of the vehicle 11, and the axis in the longitudinal direction of the vehicle 11 and the x-axis Is the angle formed by the above-mentioned markers 16r, 16r
1 and the distances Rr, Lr, between the ultrasonic oscillators 13R, 13L.
Rl, Ll, and distance w between ultrasonic oscillators 13R, 13L
Can be specified as follows.

[0031]

(Equation 1)

In the above equation (1), S represents the ultrasonic oscillator 1
From the rear end of the vehicle 11 where the 3R and 13L are disposed, the vehicle 1
1 is the distance to the rear axle 11a,₁, K_Two,
Y₁, Y _Two, Α, J₁, J_TwoAre represented by the following equations, respectively.
Variable.

[0033]

(Equation 2)

As described above, according to the apparatus for detecting the distance between two points on the vehicle 11 and two points on the ground, such as the moving body position detecting apparatus 10 of the present embodiment, the position and posture of the moving body are detected. The vehicle 1 can be placed in the garage 12 by combining it with, for example, steering control and throttle control.
It is also possible to automatically guide 1.

However, the moving object position detecting device 10
When the pedestrian is mounted on the vehicle 11, the pedestrians, the street trees, and the like are provided with the markers 16r and 16l and the ultrasonic oscillators 13R and 13L.
It is necessary to consider the influence on the transmission and reception of signals performed between them. This is because, in view of the fact that the vehicle 11 is used in a wide range of environments, it is not always possible to execute transmission and reception of signals in a favorable state.

FIG. 5 shows the marker 161 and the ultrasonic oscillator 13.
This illustrates a state in which a pedestrian 20 is interposed between the ultrasonic generator 13R and an indirect wave reflected by a wall 21 existing beside the garage 12 is incident on the ultrasonic oscillator 13R. As shown in the figure, in such a situation, the ultrasonic wave emitted from the marker 16l propagates a distance Rl 'longer than the linear distance Rl between the marker 16l and the ultrasonic oscillator 13R, and the ultrasonic oscillator 13R
To reach.

Therefore, the time required for the ultrasonic wave emitted from the marker 16l to reach the ultrasonic oscillator 13R becomes longer than the original time, and the control device 14
The linear distance between 1 and the ultrasonic oscillator 13R is detected as Rl '. If such an erroneous detection is performed, the calculation result of the coordinates (X, Y) executed according to the above equation (1) naturally becomes an erroneous value, and no action is taken for this. For example, a trouble such as the vehicle 11 being guided to an incorrect position occurs.

By the way, as described above, the moving object position detecting device 10 of this embodiment uses the distances Rr, Lr, Rl, Ll and the distance w between the ultrasonic oscillators 13R, 13L to determine the coordinates (X, Y) and the attitude angle θ. Is calculated. In this case, α in the above equation (4) is the marker 16r, 1
This is a value equal to the distance W between 6l. Therefore, W is represented by K ₁ , K ₂ , Y ₁ , Y represented by the above equations (2) and (3).
It can be expressed as follows using ₂ .

[0039]

(Equation 3)

Here, since the distance w between the ultrasonic oscillators 13R and 13L is known, the distances Rr, Lr, R1, and L are eventually obtained.
Once l is determined, the markers 16r, 16r,
The distance W between 16l can be calculated. The calculation result is equal to the known distance W if the distances Rr, Lr, Rl, and Ll have been properly detected. If the distances Rr, Lr, Rl, and Ll have been erroneously detected for some reason, the calculation result is known. Is calculated as a value different from the distance W.

Therefore, the moving body position detecting device 1 of this embodiment
0, when the distances Rr, Lr, Rl, Ll are detected, the coordinates (X, Y) and attitude angle θ of the vehicle 11 are calculated based on those values, and the distance W between the markers 16r, 16l is calculated. Only when the result is a proper value, the coordinates (X, Y) and the posture angle θ are recognized as proper values.

The above equations (1) to (7) represent the coordinates (X, X) from the detected distances Rr, Lr, Rl, Ll and the known w.
Y), a relational angle for determining the attitude angle θ, and the distance W between the markers 16r and 16l. Similarly, the distances Rr, Lr, Rl, L
It is also possible to obtain the coordinates (X, Y), the attitude angle θ, and the distance w between the ultrasonic oscillators 13R, 13L from the distance l and the known distance W between the markers 16r, 16l. Verification is possible using either of them.

FIG. 6 shows a flowchart of a routine executed by the control device 14 to realize such processing. Hereinafter, the operation of the moving object position detecting device 10 will be described with reference to FIG. This routine is executed by a microcomputer or the like constituting the control device 14, and is, for example, a periodic interrupt routine started every one second.

When this routine is started, first, in step 1
00, the markers 16r, 16l
Rr, Lr, R between the distance and the ultrasonic oscillators 13R, 13L
l and Ll are measured. In the present embodiment, by executing step 100, the above-described distance detecting means 3 is realized.

After measuring these distances Rr, Lr, Rl, Ll based on the propagation time of the ultrasonic signal, the process proceeds to step 102, where these values and the previously stored ultrasonic oscillators 13R, 13L are measured. The distance w is substituted into the above equation (1), and the coordinates (X,
Y) and the attitude angle θ of the vehicle 11 are calculated. Thus, the present step 102 corresponds to the above-described position calculating means 4.

Steps 104 and 106 are steps for judging whether or not the coordinates (X, Y) and the attitude angle θ thus obtained are appropriate values. And a main part of the present embodiment corresponding to the true / false inversion means 6.

That is, at step 104, the detected Rr, Lr, Rl, Ll,
The distance W between the markers 16r and 16l is calculated based on the known w. In step 106, whether W is calculated as a value within a preset error range, that is, W ₀ −ΔW <with respect to the known value W ₀ and the allowable range ΔW.
It is determined whether or not W <W + ΔW is satisfied.

Here, if the distance W between the markers 16r and 16l satisfies the above condition, the step 10
It is ensured that the distances Rr, Lr, Rl, Ll measured at 0 are appropriate values. Therefore, in such a case, the values of the calculated coordinates (X, Y) and the posture angle θ are determined to be appropriate values, and the subsequent processing is continued.

That is, after the counter N described later is cleared to "0" in step 108, the routine proceeds to step 110, where the steering angle of the vehicle 11 is controlled. Then step 11
In 2, it is determined whether or not the current position of the vehicle 11 is the parking end position. If the current position of the vehicle 11 has reached the parking end position, the process ends. If it is determined that the vehicle has not yet reached the parking end position, the process returns to step 100, and thereafter, the processing of steps 100 to 112 is repeatedly performed until it is determined that the vehicle 11 has reached the parking end position. .

By the way, in step 106,
It is determined that W ₀ −ΔW <W <W + ΔW does not hold when obviously an abnormal value is calculated as W. Therefore, the distances Rr, Lr, Rl,
The value of Ll is not appropriate, and thus the distances Rr, Lr, R
It can be determined that the values of the coordinates (X, Y) and the posture angle θ calculated based on l and Ll are not appropriate. Therefore, in such a case, X, Y,
Step 114 without taking the value of θ as an update value
Proceed to.

Step 114 is to count the number of times that the condition is not satisfied in step 106.
This is the step of incrementing the counter N. This counter N is a counter that is cleared in step 108 when the condition of step 106 is satisfied as described above. Therefore, the value of N indicates the number of times of abnormal value detection.

[0052] Then, in step 116, the value of the counter N has to determine exceeds a predetermined reference value N _0,
If it is determined that the error has not yet been exceeded, it is determined that some minor abnormality has occurred, and after "abnormal data is being detected" is displayed in step 118, the processing in step 100 and thereafter is repeatedly executed. .

Therefore, as shown in FIG. 5, when an obstacle such as the pedestrian 20 continuously intervenes between the ultrasonic oscillators 13R and 13L and the markers 16r and 16l, every time the routine is started. Then, the condition of step 106 is not satisfied, and eventually the condition N> N _{0 of} step 116 is satisfied.

Therefore, in this embodiment, if the abnormal state continues until N> N ₀ is satisfied in step 116, the process proceeds to step 120, where N is cleared to “0”, and then to step 122. For example, a call or display such as "Parking position cannot be detected. Move obstacle between sensors." Is performed to end the processing.

As a result, in the moving object position detecting device 10 of the present embodiment, the distance R that is ensured to be an appropriate value is obtained.
Only the coordinates (X, Y) and the attitude angle θ calculated based on the r, Lr, Rl, and Ll data are adopted as appropriate data, and the detection accuracy of the position of the vehicle 11 can be constantly maintained at a high level. it can.

As shown in the routine of FIG. 6, in the system that performs the steering angle control based on the detected position, the vehicle 11 is not guided to an inappropriate position due to an obstacle. Further, as described above, if the processing is continued as “abnormal data is being detected” for a predetermined period after the abnormality is detected, the trouble that the processing is stopped each time due to a temporary abnormal state due to the passage of a pedestrian or the like is eliminated. Therefore, it is possible to realize vehicle control according to the actual situation.

In the above embodiment, the distances Rr, Rr between the ultrasonic oscillators 13R, 13L and the markers 16r, 16l are determined.
In measuring Lr, Rl, and Ll, a method is employed in which an electromagnetic wave is emitted together with the ultrasonic signal to measure the propagation time of the ultrasonic signal and substitute the values for the distances Rr, Lr, Rl, and Ll. The distance measurement is not necessarily limited to the above method.

FIG. 7 shows another embodiment of the moving object position detecting apparatus according to the present invention, which shows the entire structure of the apparatus which does not require the transmission and reception of electromagnetic waves between the ground and the moving object.

That is, the vehicle 31 includes ultrasonic oscillators 32R and 32L corresponding to the receivers 2R and 2L described above,
A control device 33 for transmitting and receiving signals to and from the ultrasonic oscillators 32R and 32L and realizing the distance detecting means 3, the position calculating means 4, the known distance calculating means 5, and the correctness determining means 6 is mounted. And there is no device corresponding to the electromagnetic wave receiver 15 in the above embodiment.

On the other hand, on the ground, that is, on the garage 12 side, the repeaters 34r, 34 corresponding to the transmitters 1r, 11 described above.
1 and a signal generator 34 for transmitting and receiving signals to and from these repeaters 34r and 34l, and there is no device corresponding to the electromagnetic wave transmitter 18 in the above embodiment.

Here, the ultrasonic oscillator 32R of this embodiment,
The 32L and the repeaters 34r and 34l are identical in configuration to the ultrasonic oscillators 13R and 13L and the markers 16r and 16l, but in this embodiment, both function as a transmitter and a receiver for an ultrasonic signal.

The control device 33 controls the ultrasonic oscillator 32
Distances Rr, L between R, 32L and repeaters 34r, 34l
r, Rl, Ll are detected in accordance with the following principle, the coordinates (X, Y) and the attitude angle θ of the vehicle 31 are calculated based on the values, and the calculated values are calculated using the distance W between the repeaters 34r, 34l. Is to verify whether or not is appropriate.

The principle of detecting the distance between the ultrasonic oscillators 32R, 32L and the repeaters 34r, 34l in the moving object position detecting device 30 of the present embodiment will be described below with reference to the time chart shown in FIG.

[0064] FIG. 8 (A) shows a state in which the ultrasonic generator 32L mounted on the vehicle 11 transmits the ultrasonic wave at time t _0. The ultrasonic waves emitted in this way reach the repeater via the distances Lr and Ll, respectively. Accordingly, the time at which the repeaters 34r and 34l receive the ultrasonic signals is a function of the distances Lr and Ll. For example, when Ll is longer than Lr as shown in FIG.
r receives an ultrasonic signal earlier than the repeater 34l.

Therefore, when the reception time of the above-mentioned ultrasonic signal is represented for each of the repeaters 34r and 34l, the time t ₁ is obtained for the repeater 34r and the time is obtained for the repeater 34l as shown in FIGS. 8 (D) and 8 (F). latest time t ₄ than t ₁ is the time of reception of ultrasonic signals.

When the repeaters 34r and 34l of the mobile object position detecting device 30 of the present embodiment receive the ultrasonic signals, the repeaters 34r and 34l immediately receive the r signals,
1 signal is returned. Here, if repeater 34r, the response time in 34l as Delta] t, FIG. 8 (C), the time t ₅ corresponds after Delta] t time t ₄ from the repeater 34r (E), the addition, the repeater 34l Is the time t
Each r signal at time t ₂ corresponding after ₁ Delta] t, so that the l signal is returned.

Then, the r signal and the l signal are moved backward by distances Lr and Ll from the repeaters 34r and 34l toward the ultrasonic oscillator 32L, respectively, and then transmitted to the ultrasonic oscillator 32L as shown in FIG. will be reached, t ₃ and time t _6.

In this case, the time (t ₃ -t ₀ ) required from the time when the ultrasonic oscillator 32L emits the ultrasonic signal to the time when the r signal is received is determined by the time when the ultrasonic wave having the propagation velocity v is equal to the ultrasonic oscillator 32L and the repeater. It can be grasped as the sum of the time (2 × Lr / v) required to reciprocate the distance Lr from the repeater 34r and the response speed Δt of the repeater 34r.

The time required from when the ultrasonic oscillator 32L emits an ultrasonic signal to when it receives the 1 signal (t ₆ −
t ₀ ) is the time (2 × Ll / v) required for the ultrasonic wave having the propagation velocity v to reciprocate the distance Ll between the ultrasonic oscillator 32L and the repeater 34l and the response speed Δt of the repeater 34l.
Can be understood as the sum of

In this case, the response speeds of the repeaters 34r and 34l are both Δt, and there is no difference between them. Therefore, the distances Lr and Ll can be expressed as follows.

Lr = {(t ₃ −t ₀ ) −Δt} × v / 2 (8) Ll = {(t ₆ −t ₀ ) −Δt} × v / 2 (9) , (T ₃ −t ₀ ) and (t ₃ )
_{If 6−} t ₀ ) is measured, the distances Lr and Ll can be easily obtained. The above principle is based on the distance R between the ultrasonic oscillator 32R and the repeaters 34r and 34l.
The same applies to the determination of r and Rl. The ultrasonic oscillator 32R and the ultrasonic oscillator 32L transmit ultrasonic signals at appropriate intervals, and alternately Lr, L1 and Rr, R
l, all the distances Rr, Lr, Rl, Ll necessary for calculating the coordinates (X, Y) and the posture angle θ.
Can be easily detected.

As described above, according to the moving body position detecting device 30 of the present embodiment, the distances Rr, Lr, Rl, Ll can be measured without transmitting and receiving electromagnetic waves between the moving body and the ground. The configuration can be simplified. If the control device 33 executes the routine shown in FIG. 6, the ultrasonic oscillators 32R and 32L and the repeaters 34r and 34r, 3 similarly to the moving object position detection device 10 described above.
When any obstacle intervenes between 4l
The effect can be eliminated.

FIG. 9 shows the moving object position detecting device 30 as
An example applied to a vehicle guidance system for appropriately guiding a vehicle 11 into a garage 12 adjacent to a wall 21 is shown.

When the garage 12 is provided adjacent to the wall 21 as shown in FIG. 9, in order to secure a wide guiding area of the vehicle 11 without being affected by the wall 21,
It is preferable to dispose the repeaters 34r and 34l at the forefront. However, the repeaters 34r and 34l and the ultrasonic oscillators 32R and 32L are set to transmit and receive signals when the vehicle 11 is located in front of the garage 12, and the repeaters 34r and 34l and the ultrasonic oscillators 3
The 2R and 32L cannot effectively transmit and receive signals in any case.

That is, as shown in FIG.
r and 341 have regions which can effectively transmit and receive signals to and from the ultrasonic oscillators 32R and 32L, respectively.
When R and 32L are located, the repeaters 34r and 34l and the ultrasonic oscillators 32R and 32L cannot continue proper communication.

When the wall 21 is present adjacent to the garage 12 as shown in FIG. 9, the ultrasonic oscillators 32R, 3R located outside the effective operation area are located.
2L is transmitted to the repeaters 34r and 34 by indirect waves through the wall 21.
If this state cannot be detected in some cases, erroneous vehicle guidance will be continued based on erroneous distance data.

In this case, as described above, the moving object position detecting device 30 mounted on the vehicle 11 can appropriately detect such a situation and stop erroneous vehicle guidance. Here, in the vehicle guidance system shown in FIG. 9, repeaters 36r and 36l are installed on both sides of the rear end of the garage 12, and when the moving body position detecting device 30 detects that communication with the repeaters 34r and 34l cannot be continued, the repeater 36r , 36
1 is started.

According to such a configuration, even if there is any object adjacent to the garage 12 like the wall 21 shown in FIG.
The vehicle 11 can be appropriately guided to the rear end of the garage 12, and a practical vehicle guidance system can be constructed. Although the vehicle guidance system shown in FIG. 9 uses the moving body position detecting device 30, the vehicle guiding system can be similarly configured by the moving body position detecting device 10 described above.

In each of the above embodiments, the ultrasonic oscillators 13R, 13R corresponding to the receivers 2R, 2L are used.
L, 32R, 32L are installed on the vehicle 11 and the markers 16r, 16l or repeaters 34r, 34l corresponding to the transmitters 1r, 11l are installed on the garage 12 side, but the ultrasonic oscillators 13R, 13L, 32R, 32
L may be mounted on the garage 12, and the markers 16r and 16l or the repeaters 34r and 34l may be mounted on the vehicle 11.

In this case, for example, if the position of the vehicle 11 is detected on the garage 12 side and the detection result is transmitted to the vehicle 11, the mobile body position detecting devices 10 and 30 of the above-described embodiments can be used.
It is possible to realize a guidance system for the vehicle 11 in the same manner as described above.

[0081]

As described above, according to the present invention, two transmitters or two receivers installed on a reference object, and two transmitters or two receivers mounted on a mobile body After detecting the distance to the vehicle, the position data of the vehicle is updated only when it is verified that these distances are appropriate distances in relation to the known distance between the receivers or the distance between the transmitters.

For this reason, in the case where some obstacle is interposed between the transmitter and the receiver, the abnormality is accurately detected and the updating of the position data of the vehicle is stopped.
There is a feature that highly accurate position detection can be performed without being affected by such obstacles.

[Brief description of the drawings]

FIG. 1 is a principle diagram of a moving object position detecting device according to the present invention.

FIG. 2 is an overall configuration diagram of an embodiment of a moving object position detecting device according to the present invention.

FIG. 3 is a time chart for explaining a principle of measuring a distance between an ultrasonic oscillator and a marker in the moving object position detecting device of the present embodiment.

FIG. 4 is a setting example of a coordinate system in the moving object position detecting device of the present embodiment.

FIG. 5 is an overall view showing a situation where a pedestrian intervenes as an obstacle between the ultrasonic oscillator and the marker in the moving object position detecting device of the present embodiment.

FIG. 6 is a flowchart of a routine executed by the moving object position detecting device according to the present embodiment.

FIG. 7 is an overall configuration diagram of another embodiment of the moving object position detecting device according to the present invention.

FIG. 8 is a time chart for explaining a principle of measuring a distance between an ultrasonic oscillator and a repeater in another embodiment of the moving object position detecting device according to the present invention.

FIG. 9 is an overall configuration diagram of a vehicle guidance system configured using the moving object position detection device according to the present invention.

[Explanation of symbols]

 1r, 1l transmitter 2r, 2l receiver 3 distance detecting means 4 position calculating means 5 known distance calculating means 6 true / false determining means 10, 30 moving object position detecting device 11, 31 vehicle 12 garage 13R, 13L, 32R, 32L ultrasonic wave Oscillator 14, 33 Controller 15 Electromagnetic wave receiver 16r, 16l Marker 17, 35 Signal generator 18 Electromagnetic wave transmitter 20 Pedestrian 21 Wall 34r, 341, 36r, 36l Repeater

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-213877 (JP, A) JP-A-4-277900 (JP, A) JP-A-5-19853 (JP, A) JP-A-5-1985 2422 (JP, A) JP-A-7-20223 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01S 11/00-11/16 G01S 5/30 G01S 15/00- 15/96

Claims (1)

(57) [Claims] 1. Two transmitters spaced apart from each other;
Two receivers spaced apart from each other, a mobile unit equipped with one of the two transmitters or the two receivers, a reference object equipped with the other, and between each transmitter and each receiver A moving body position detecting device comprising: a distance detecting means for detecting a distance of the moving object; and a position calculating means for calculating a relative position between the reference object and the moving body based on the distance data detected by the distance detecting means. Known distance calculating means for calculating at least one of the distance between the two receivers and the distance between the two transmitters whose intervals are known, based on the distance data detected by the detecting means; A moving body position detecting device comprising: a correctness / incorrectness determining means for determining whether the detection data of the distance detecting means is correct or not by comparing the calculation result of the distance and known distance data.