JP2933954B2 - Moving object speed detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a moving object speed detecting device for detecting the speed of a moving object such as a train, which is arranged at intervals along the traveling direction of the moving object. A moving body speed detecting device including first and second moving body detectors, and a speed calculating device that calculates the speed of the moving body from detection signals given from the two moving body detectors, wherein the speed calculating device includes: From the rising and falling times of the detection pulse obtained from the detection signal, calculate the intermediate time of each, calculate the lower time between the two intermediate times, and calculate the speed of the moving object based on the calculated lower time With this configuration, the speed of the moving object can be accurately detected without being affected by the detection signal which is an analog signal and a threshold level fluctuation for obtaining a detection pulse from the detection signal. Than it is.

<Prior Art> Conventionally, in a moving object detecting device such as a train speed detecting device, a first moving object detector is provided at an interval L along a traveling direction of a moving object 1 as shown in FIG. The second and second moving body detectors 3 are arranged, and the detection signals E ₁ and E ₂ obtained by the moving body detectors 2 and 3 are given to the speed calculation device 4. The moving body detectors 2 and 3 are axle detectors known, for example, from Japanese Patent Publication No. 58-42929, and output analog detection signals E ₁ and E ₂ .

The speed calculating device 4 applies a fifth
As shown in the figure, a fixed threshold level V _S is set, and detection pulses P ₁ and P ₂ are created. Then, the speed v of the moving object 1 is calculated and output from the time difference Δt between the detection pulses P ₁ and P ₂ and the interval L between the moving object detectors 2-3. Reference numeral 5 denotes a traveling path such as a track.

Time difference △ t of the detection pulses P _1, P ₂ has a rising time t ₁₀ of the detection pulse P _1, captures a rising time t ₂₀ of the detection pulse P _2, obtained as △ t = t ₂₀ -t _10.

<Problems to be Solved by the Invention> However, in the above-described conventional moving body speed detection device, when the detection signals E ₁ and E ₂ given as analog signals from the moving body detectors 2 and 3 change, the detection pulse
Rising time t ₂₀ of rise of P ₁ at t ₁₀ and the detecting pulse P ₂ is changed. For example, as shown in FIG. 6, E from the first moving body detection element 2 detects the signal E ₁ is E ₁₁ given from ₁₂
When the rising edge of the detection pulse P ₁
Δt changes by ₁₀ and Δt changes by this amount.
The same applies when the threshold level V _S fluctuates. For this reason, there is a problem that the time difference Δt, which is a reference for speed detection, fluctuates, and the speed detection accuracy is reduced.

Therefore, an object of the present invention is to solve the above-described conventional problems, and to provide a detection signal obtained by a moving body detector and a threshold level for obtaining a detection pulse from the detection signal without being affected by a threshold level fluctuation. Another object of the present invention is to provide a moving object speed detecting device capable of detecting the speed of a moving object with high accuracy.

<Means for Solving the Problems> In order to solve the above-described problems, the present invention provides first and second moving body detectors arranged at intervals along the traveling direction of the moving body, and the moving body A speed calculating device that calculates the speed of the moving object based on a detection signal given from a detector, wherein the speed calculating device includes the first and second moving object detectors. First and second detection pulses are created from the respective detection signals given by the first and second detection pulses, respectively, from the rising and falling times of the first detection pulse, and from the rising and falling times of the second detection pulse, respectively. And the time difference between the two intermediate times is calculated, and the calculated time difference is compared with the first moving object detector and the second time.
Calculating and outputting the speed of the moving body from the distance between the moving body detectors, the first moving body detector and the second moving body detector,
It is characterized in that the detection pulses are arranged at intervals overlapping with each other in time.

<Operation> The speed calculation device creates first and second detection pulses from the respective detection signals provided from the first and second moving body detectors. The detection signal is an analog quantity, and the speed calculation device sets a threshold level for the analog detection signal to generate the above-described detection pulse.

Then, an intermediate time is calculated from the rising and falling times of the first detection pulse and the rising and falling times of the second detection pulse, and the time difference between the two intermediate times is calculated. Although the rise and fall of the detection pulse vary depending on the detection signal and the threshold level fluctuation, the intermediate time is substantially constant irrespective of the fluctuation of the detection signal and the threshold level.

Accordingly, by calculating the speed of the moving object from the time difference calculated as described above and the interval between the first moving object detector and the second moving object detector, the detection output from the moving object detector is calculated. It is possible to accurately detect the speed of the moving object without being affected by the fluctuation of the threshold level for obtaining the detection pulse from the signal and the detection signal.

<Embodiment> Fig. 1 is a diagram showing a configuration of a moving body speed detecting device according to the present invention together with a time chart of detection pulses. In the figure, the same reference numerals as those in FIG. 4 indicate identical components. The speed calculation device 4 calculates a first signal from each of the detection signals E ₁ and E ₂ given from the first and second moving object detectors 2 and 3.
And the second detection pulses P ₁ and P ₂ are created.

Then, down time t ₁₁ up to the first rising time t ₁₀ of the detection pulse P _1, and, when the second detection pulse P ₂ rising t ₂₀
Falling time t ₂₁ and, to calculate each intermediate time t _m1, t _{m @ 2,} to calculate the time difference △ t = t _m2 -t _m1 of both the intermediate time t _m1, t _m2. T ₁₀ , t ₂₀ at rising of detection pulse P ₁ , P ₂
And the falling times t ₁₁ and t ₂₁ change depending on the fluctuations of the detection signals E ₁ and E ₂ and the threshold level V _S , but the intermediate times t _m1 and t _m2 are the detection signals P ₁ , P ₂ and It is substantially constant irrespective of fluctuations in the threshold level V _S. For example, as shown in FIG. 2, when the detection signal E ₁ provided from the first moving body detection element 2 is changed as E ₁₂ from E _11, rises at t ₁₀ the detection pulse P ₁ △ t ₁₀ only changes in time extending direction, it is t ₁₁ when falling △ t
It changes in the direction shortened by ₁₁ . Therefore, the detection signal E ₁
Despite There was change as E ₁₂ from E _11, the intermediate time t _m1 is kept substantially constant. Second moving body detector 3
The same applies with respect to the detection signals E _2, also applies to the case where the threshold level V _S is varied.

Therefore, the time difference Δt calculated as described above,
By calculating the speed v of the moving body 1 from the distance L between the first moving body detector 2 and the second moving body detector 3, the detection signals E ₁ , E ₂ and the threshold level V _S are obtained. The speed v of the moving body 1 can be accurately detected without being affected by the fluctuation.

FIG. 3 is a diagram showing the relationship between another arrangement example of the first moving body detector 2 and the second moving body detector 3 in the moving body speed detecting device according to the present invention and the detection pulse. In this embodiment, an arrangement example for identifying the traveling direction of the moving body 1 is shown.
The first moving body detector 2 and the second moving body detector 3 are arranged at an interval L at which the detection pulses P ₁ and P ₂ temporally overlap each other. Therefore, the distance L between the first moving body detector 2 and the second moving body detector 3 is significantly shorter than that in the embodiment shown in FIG. In such a short interval L, the detection pulse P _1, the prior art for detecting the speed v from the time difference t ₂₀ -t ₁₀ at the time of rising of P ₂ t _10, t _20, the time of rising
Even if t ₁₀ and t ₂₀ fluctuate slightly, the detected speed v greatly fluctuates, and the detection error increases.

In the present invention, when the first detection pulse P ₁ rise
time interval of falling at the time t ₁₁ Standing and _{t 10 (t 11 -t 10)} , and,
Fall time t ₂₁ up to the second sensing rising time t ₂₀ pulse P ₂
From these, the respective intermediate times t _m1 and t _m2 are calculated, and the time difference Δt = t _m2 −t _m1 between both the intermediate times t _m1 and t _m2 is calculated. The calculated time difference Δt and the first movement Since the speed v of the moving body 1 is calculated from the distance L between the body detector 2 and the second moving body detector 3, even when the distance L is short, the detection signals E ₁ and E ₂ and the threshold level are obtained. The speed v of the moving object 1 can be accurately detected without being affected by the fluctuation of V _S.

<Effects of the Invention> As described above, in the moving object detection device according to the present invention, the speed calculation device performs the first and second detections based on the detection signals given from the first and second moving object detectors. Each pulse is created, and at the time of rising and falling of the first detection pulse, and at the time of rising and falling of the second detection pulse, the respective intermediate times are calculated,
A time difference between the two intermediate times is calculated, and a speed of the moving object is calculated from the calculated time difference and an interval between the first moving object detector and the second moving object detector. And the second moving body detector has a detection signal output from the moving body detector and a detection pulse for obtaining the detection pulse from the detection signal since the detection pulses are arranged at intervals overlapping with each other in time. It is possible to provide a moving object speed detecting device capable of detecting the speed of the moving object with high accuracy without being affected by the fluctuation of the threshold level.

[Brief description of the drawings]

FIG. 1 is a diagram showing the configuration of a moving object speed detecting device according to the present invention together with a time chart of detection pulses, FIG. 2 is a diagram showing the operation of the moving object speed detecting device according to the present invention, and FIG.
The figure shows the relationship between another example of the arrangement of the first moving object detector and the second moving object detector in the moving object speed detecting device according to the present invention and the detection pulse, and FIG. 4 shows the conventional moving object detector. FIG. 5 is a diagram showing a configuration of a speed detecting device, FIG. 5 is a diagram showing a relationship between another arrangement example of the first moving body detector and the second moving body detector and a detection pulse, and FIG. It is a figure showing a problem. 1... Moving body 2... First moving body detector 3... Second moving body detector

Claims (1)

(57) [Claims] 1. A moving object, comprising: first and second moving object detectors arranged at intervals along a traveling direction of a moving object; and a speed of the moving object based on a detection signal given from the moving object detector. And a speed calculating device that calculates the first and second detection pulses from the respective detection signals given from the first and second moving object detectors. Are created respectively, at the time of rising and falling of the first detection pulse, and
An intermediate time is calculated from the rising time and the falling time of the second detection pulse, and the time difference between the two intermediate times is calculated. The calculated time difference is compared with the first moving object detector and the second movement. Calculating and outputting the speed of the moving body from the interval of the body detectors, the first moving body detector and the second moving body detector determine an interval at which the detection pulses temporally overlap each other. A moving object speed detecting device, which is arranged at a distance.