JPH0543362Y2 - - Google Patents

Description

[Detailed explanation of the idea]

(Industrial Application Field) The present invention relates to a vehicle position detection device that detects the passing position of a vehicle on a circular test course used for vehicle running tests. (Prior art) In a driving test using a test course, which is carried out during the development of a vehicle, depending on the purpose of the test, the driver or an observer outside the vehicle must confirm the passing points of the vehicle on the test course. Therefore, this type of test course is equipped with a vehicle position detection device that detects the position of a running vehicle. This vehicle position detection device is generally used in automatic guided vehicles (for example, see Japanese Patent Application Laid-Open No. 53-114172), and a cable connected to an oscillator is connected to a road surface at a predetermined detection point provided on a test course. While the cable is buried across the cable, a pick-up coil is installed on the vehicle side, and by detecting the induced magnetic field generated around the cable, it is possible to confirm that the vehicle has passed the detection point. It is the composition. In that case,
Since a plurality of detection points are provided on the test course, a plurality of cables B ₁ , B ₂ . . . connected to a plurality of oscillators A ₁ , A ₂ . Each detection point D ₁ , D ₂ ... of the test course C is arranged in different combinations,
The vehicle is configured to be able to identify which detection point the vehicle has passed by using a combination of frequencies detected by a pickup coil on the vehicle side. However, in this type of vehicle position detection device, as shown in FIG. _{8 ,} cables B ₁ , B ₂ . At the same time, each cable _{B 1 , B 2 .} As shown in the diagram, one detection point crosses the road surface from the outer circumference side to the inner circumference side of the test course C, and then the other detection points cross the road surface from the inner circumference side to the outer circumference side. , the above cable storage groove E must be provided on both the inner and outer circumferential sides of the test course C. Therefore, the cost of installing this type of vehicle position detection device increases. Furthermore, according to the cable arrangement shown in Fig. 8, the cables B ₁ , B _{2 .} . . only cross the road surface once at each detection point D ₁ , D 2 . When the traveling speed is high, the detection time of the magnetic field by the pick-up coil becomes extremely short, making it difficult to detect the position reliably. (Purpose of the invention) This invention deals with the above-mentioned actual situation regarding vehicle position detection devices installed on test courses. , it is possible to identify a large number of detection points with a small number of cables and oscillators, and at the same time, it is possible to centrally arrange each of the above cables on one side of the test course at locations other than the detection points, which makes it possible to store cables. The installation cost of this type of equipment is reduced by making it sufficient to provide a magnetic field groove only on one side of the test track, and at the same time ensuring that sufficient magnetic field detection time is obtained at each detection point even when the vehicle is running at high speed. It is an object of the present invention to enable reliable and accurate detection of the passing position of a vehicle. (Structure of the invention) That is, the vehicle position detection device on the vehicle test course according to the invention detects the passing position of the vehicle by detecting the magnetic field generated on the road surface of the test course via the pickup coil on the vehicle side. In the detection device, a plurality of cables each connected to a plurality of oscillators with different oscillation frequencies are stored in a cable storage groove provided along the inner circumference of the test course, and these cables are
A loop section is provided that crosses the road surface in a U-shape at a plurality of detection points provided on the road surface. In that case, set the combination of cables provided with this loop part to be different for each detection point,
The pick-up coil is configured to detect a combination of magnetic fields of different frequencies generated by each loop section at each detection point, and the magnetic fields generated by both of the outward and return paths crossing the road surface of the loop section overlap. They are characterized in that they are arranged at a predetermined width apart so that a wide magnetic field is formed. (Effect of the invention) As described above, according to the invention, the frequency combination of the induced magnetic field formed by the loop portion of each cable at each detection point on the test course is different at each detection point. It is possible to identify a large number of detection points with a small number of cables and oscillators, and these cables can be concentrated on one side of the test course at locations other than the above detection points. It is sufficient to provide a cable storage groove for storing the cable only on one side of the test course, especially on the inner circumferential side where the distance is shorter. This reduces the cost of installing this type of vehicle position detection device. In addition, at each of the above detection points, each cable crosses the road twice with a predetermined width apart, and a wide induced magnetic field is formed on the outbound and return trips, which creates a pickup coil on the vehicle side. This increases the magnetic field detection time, making it possible to reliably detect the passing position of the vehicle even when the vehicle is traveling at high speed. (Example) Hereinafter, an example of the present invention will be described. As shown in FIG. 1, a plurality of vehicle passing position detection points 2...2 are set at predetermined positions on a circular test course 1, and a cable is installed along the inner circumference of the test course 1. A housing groove 3 is provided, and a magnetic field generating cable 5 connected to an oscillator 4 is housed in the groove 3. This cable 5 extends from the inner circumferential side to the outer circumferential side of the test course 1 at each of the detection points 2...2, and then
U-shaped loop portions 6...6 that make a U turn and return to the inner circumferential side again are provided, and these loop portions 6...6
is buried in the road surface, so that an induced magnetic field corresponding to the oscillation frequency of the oscillator 4 is generated on the road surface at each detection point 2...2. By the way, the oscillator 4 and the cable 5 are, in detail, a plurality of oscillators 4 ₁ to 4 _o having different oscillation frequencies and these oscillators 4 1 to ₄ o as shown in FIG.
It is composed of a plurality of cables 5 ₁ to 5 _o respectively connected to 4 _o , and each cable 5 ₁ to
5 _o is a power supply section 7 ₁ - _{7 o} that starts from the corresponding oscillator 4 ₁ - 4 _o and goes around the storage groove 3 approximately once along the inner circumferential side of the test course 1; _o
Turning portions 8 ₁ to 8 _o that make a U turn in the vicinity of
Then, the return portions 9 1 to 9 _o pass through the storage groove 3 again from the folded portions 8 ₁ to 8 o, go around the inner circumferential side of the test course 1, and return to the corresponding oscillators 4 ₁ to _{4 o .} Each detection point 2 of test course 1...
2, the loop portion 6 crossing the road surface is provided in the power feeding portions 7 ₁ to 7 _o . As shown in FIG. 3, the loop portion 6 is inserted into non-magnetic pipes 10, 10, and is buried in the road surface with a certain distance L between the outbound and return trips. . However, each of the cables 5 ₁ to 5 _o does not have a loop portion 6 at every detection point 2 . . . ₂ , but as shown in FIG. 3 cable 5
₂ , 5 ₃ have loop portions 6 ₂ , 6 ₃ , and at the Mth detection point 2 m, the first, third, and fourth cables 5 ₁ , 5 ₃ , and 5 ₄ have loop portions 6 ₁ , 6 _{3 .} , 6 ₄ , and so on, the cable 5 ₁ to 6 has loop portions 6 ₁ to 6 _o at each detection point 2...2.
5 All combinations of _o are now different.
In that case, the loop portion 6 ₁ of each cable 5 ₁ to 5 _o
~6 _o Since the frequency of the induced magnetic field generated at each detection point 2...2 is different, the induced magnetic field of one or more frequencies is synthesized in different combinations at each detection point 2...2. This results in the formation of a magnetic field. Here, as shown in the figure, oscillator 4 and cable 5
If 5 sets of cables are provided, a total of 31 cable combinations will be obtained as shown in Table 1. Therefore, in this case, there will be 31 detection points 2...2. Different magnetic fields can be generated for each. In Table 1, the mark ◯ indicates a cable that has a loop portion at the detection point, and the mark x indicates a cable that does not have a loop portion.

[Table] On the other hand, as shown in FIG. 3, a pickup coil 12 is attached to the front of the vehicle 11 running on the test course 1, and as shown in FIG. is configured. This circuit 13 receives the output of the pickup coil 12 and outputs the oscillators 4 ₁ to 4 _{o .}
The filters 15 ₁ have the same number as the oscillators 4 _{1 to 4 o, which pass only frequency components equal to the oscillation frequency of the oscillators 4 1} to 4 _o , respectively.
~ _15o , and a decoder 1 that determines the detection point corresponding to the combination of the outputs of these filters ₁₅₁ ~ _15o , for example according to Table 1.
It consists of 6. Next, the operation of this embodiment will be explained. It is now assumed that the vehicle 11 running on the test course 1 passes, for example, the Nth detection point 2n, and at this detection point 2n, there is a loop section of the second and third cables 5 ₂ and 5 ₃ , for example. 6 ₂ , 6 ₃
It is assumed that a magnetic field is generated on the road surface by combining two induced magnetic fields having a frequency equal to the oscillation frequency of the second and third oscillators 4 ₂ and 4 ₃ . At this time, the pickup coil 12 provided in the vehicle 11 detects the above-mentioned composite magnetic field, and an output corresponding to the magnetic field is sent from the coil 12 to the detection circuit 13.
The signal is inputted to the filters 15 ₁ to 15 _o via the amplifier 14 of the filters 15 1 to 15 o, but in this case, only the second and third filters 15 ₂ and 15 ₃ generate outputs, so the decoder 16 extracts the output from the combination of the outputs. Based on the combination table shown in Table 1, the detection point is
It is determined that it is the th detection point 2n.
This makes it possible to confirm which detection point the driver of the vehicle 11 has passed, or in other words, the current driving position on the test course 1. However, according to the above configuration, each cable 5 ₁ to
5 The loop part 6 provided at _o is the detection point 2...
As the cables 5 ₁ to 5 _o cross the road surface of the test course 1 in a U-shape at the detection points 2...2, the test course 1
Therefore, the groove 3 for accommodating these cables 5 ₁ to 5 _o is also provided only on one side of the test course 1, especially on the inner circumferential side where the distance is short. This results in lower setup costs for this type of equipment than if cable storage grooves were provided on both sides of the test track. In addition, since the loop portion 6 of each cable 5 ₁ to 5 _o crosses the road twice with a predetermined width L apart at the detection point 2...2, there is a loop portion on the road surface as shown in Fig. 5a. The magnetic fields from both the outgoing path 6' and the returning path 6'' of the vehicle 6 overlap each other to form a wide magnetic field, and therefore, when the pickup coil 12 provided in the vehicle 11 passes over this magnetic field, the same As shown in Figure b, a sufficiently long magnetic field detection time t is obtained.Here, when the distance L between the outgoing path 6' and the returning path 6'' of the loop section 6 is 1.2 m, the vehicle travels at a speed of 150 km/h. It has been confirmed that the pickup coil 12 of the vehicle generates an output for 25 msec. This makes it possible to reliably detect passage of detection points 2...2 even when the vehicle is running at high speed. In addition, as shown in FIG. 5a, the pickup coil 12 is attached to the vehicle 11 in a vertical position in conjunction with detecting the overlapping portion of two magnetic fields, but in this case, as shown in FIG. As shown, even if the attitude of the vehicle 11 with respect to the test course 1, in other words, the angle of entry of the pickup coil 12 into the magnetic field changes, the coil 12 can always detect the magnetic field under the same conditions. Therefore, the position of the vehicle 11 can be detected reliably and accurately even when the vehicle 11 is traveling in a meandering direction, for example. Furthermore, in this embodiment, each cable 5 ₁ to
5 _o is a power feeding section 7 ₁ to 7 _o that goes around the inner circumferential side of the test course 1, and a U-turn at the turning section 8 ₁ to 8 _o to go approximately in the opposite direction along the inner circumferential side of the test course 1. It has current return parts ₉₁ to _9o that go around the circuit, and these are arranged in the cable storage groove 3 in a state other than the detection points 2...2 and adjacent to each other as shown in FIG. ing. Therefore, within this cable storage groove 3, the power supply parts ₇₁ to _7o and the power return parts _{91 to 9o}
The magnetic fields generated by the grooves 3 cancel each other out on the sides of the groove 3, and as a result, the magnetic fields generated at locations other than the detection points 2...2 are applied to the pickup coil 12 of the vehicle 11 running on the test course 1. There is no adverse effect, so-called noise is reduced, and the detection sensitivity of the coil 12 is improved.

[Brief explanation of the drawing]

Figures 1 to 7 show examples of the present invention; Figure 1 is a schematic plan view of a test course showing the cable arrangement; Figure 2 is an enlarged plan view of the main parts; Figure 3 is an enlarged vertical sectional view showing the buried state of the cable at the detection point cut along the line in Figure 2, Figure 4 is a circuit diagram of the detection circuit installed in the vehicle, and Figures 5a and b are the diagrams at the detection point. A schematic diagram showing the state of the magnetic field and an output characteristic diagram of the pickup coil that detects the magnetic field. Figure 6 is a schematic plan view showing the relationship between the cable and the vehicle attitude at the detection point. Figure 7 is the inside of the cable storage groove. FIG. 2 is a schematic cross-sectional view showing the state of a magnetic field caused by a cable disposed in FIG. Furthermore, FIG. 8 is a plan view of the main part of a test course showing the arrangement of conventional cables. 1...Test course, 2...Detection point, 3
... Cable storage groove, 4 ... Oscillator, 5 ... Cable, 6 ... Loop section, 6' ... Forward path, 6'' ...
Return trip, 11... Vehicle, 12... Pick up coil.

Claims (1)

[Scope of utility model registration request] A device for detecting the passing position of a vehicle by detecting the magnetic field generated on the road surface through a pickup coil on the vehicle side on a test course for running tests of the vehicle. A cable storage groove provided along the
It consists of multiple oscillators with different oscillation frequencies and multiple cables connected to each of these oscillators and arranged in the cable storage groove, and these cables are connected to multiple detection points on the road surface. A loop section is provided that crosses the road surface in a U-shape, and the combination of cables provided with this loop section is set to be different at each detection point, so that the above-mentioned pick-up coil is connected at each detection point. Each loop section is configured to detect a combination of magnetic fields of different frequencies generated, and the outgoing and returning paths of the loop section that cross the road surface overlap to form a wide magnetic field. 1. A vehicle position detection device on a vehicle test course, characterized in that the device is arranged at a predetermined width apart from each other so that the vehicle position is detected.