JPH0529078B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention detects the presence or absence of a moving object such as a human body within a predetermined detection area, and controls the opening/closing of an automatic door or the operation of a security alarm device. The present invention relates to a moving object detection device that can be applied to a start switch for detecting a moving object.

<Prior art> Various types of moving object detection devices have been put into practical use as starting switches for detecting moving objects such as human bodies and controlling the operation of security alarm devices. A commonly used non-contact type is an infrared passive type that utilizes fluctuations in the radiated infrared light flux based on the temperature difference between the background and the moving object. As shown in FIG. 6, this detection device focuses radiant energy in a predetermined detection area onto an infrared sensor 2 using an optical system 1 consisting of a mirror or a lens. The infrared sensor 2 converts the change in the focused radiant energy into an electrical signal, and after this electrical signal is amplified by the amplifier circuit 3, it is determined by the signal level determination circuit 4 whether or not it is above the detection level. , a signal is output when it is above the detection level, and this output signal drives the alarm output circuit 5 to operate the relay and issue an alarm.

Further, as shown in FIG. 7, the infrared sensor 2 is generally a differential type sensor called a twin type sensor or dual type sensor in which two detection elements 2a and 2b of different polarities are operatively connected. Radiant energy from the floor and wall surfaces in the detection area set by the optical system 1 is constantly detected, and when a human body enters this detection area, the incident energy to the infrared sensor 2 changes,
When this variation exceeds a certain level, an alarm is output.

<Problems to be solved by the invention> By the way, the above-mentioned infrared detection elements 2a and 2b
In addition to the inherent noise of the element itself,
It has noise caused by external factors. That is, first, disturbance light from sunlight, illumination light, or automobile headlights; second, sudden changes in the ambient temperature around the infrared sensor 2 due to sunlight, wind, air conditioners, etc.; and third, sudden changes in the ambient temperature around the infrared sensor 2 caused by radio equipment, electric motors, etc. When any of the radio waves caused by electromagnetic noise or lightning induction occur,
The infrared sensor 2 reacts as a change in incident energy. The differential infrared sensor 2 described above detects noise caused by such external factors by using a pair of detection elements 2.
They can be removed by canceling each other at a and 2b. To be more specific, since the detection object of this type of detection device is a moving object, for example, when the moving object moves in the direction of the arrow in FIG. 7, as shown in FIG. 8a,
The detection signal A1 by the first detection element 2a and the detection signal B1 by the second detection element 2b are output with a certain time difference, but physical changes due to external factors are simultaneously applied to both detection elements 2a and 2b. Therefore, the detection elements 2a and 2b simultaneously output the outputs A2 and 2b as shown in FIG. 8b and c, respectively.
B2, and because they are connected differentially, voltages with opposite polarities and the same magnitude are generated and cancel each other out, so that no output is generated as the sensor 2.

However, it is impossible to make each of the detection elements 2a and 2b completely the same shape and performance, and there are considerable variations.
There is a sensitivity difference between a and 2b, and disturbances do not necessarily act equally on both detection elements 2a and 2b.
Therefore, even if it is a differential type, it is impossible to cancel out the signals A2 and B2 due to disturbance noise and make the output completely zero, and in reality, as shown in Figure 8d, a small amount of output is generated. However, if the disturbance is large, the alarm output circuit 5 will be activated and a false alarm will be issued.

<Purpose of the Invention> The present invention has been made in view of these conventional problems and to solve them, and has a very simple and inexpensive structure that offsets physical changes caused by disturbance factors. It is an object of the present invention to provide a moving object detection device that can reduce signal output to almost zero.

<Means for Solving the Problems> In order to achieve the above object, the moving object detection device of the present invention includes a differential infrared sensor in which a pair of infrared detection elements are differentially connected to each other, and a predetermined A moving object detection device configured as an infrared passive type with an optical system that focuses infrared energy emitted from a detection area on the infrared detection element,
The differential infrared sensors are combined into a set of two, and the infrared detection elements are arranged in a line parallel to the moving direction of the moving object to be detected and arranged in close proximity. An absolute value circuit that converts the output signal of the sensor into an absolute value of either positive or negative is individually connected to each of the differential infrared sensors, and each of the differential infrared sensors of the set is connected to an absolute value circuit. It is characterized by comprising a subtraction circuit that calculates the time-series difference between the absolute value outputs of the two connected absolute value circuits, and a level discrimination circuit that compares the difference signal of the subtraction circuit with a detection level. It is something to do.

<Function> Since the differential infrared sensors, each consisting of a pair of detection elements connected differentially, are combined into a set, when a physical change due to a disturbance factor occurs, each sensor's respective The pair of detection elements cancel each other out, and each sensor outputs a small signal due to variations in each pair of detection elements. Each of these signals is converted into an absolute value by an absolute value circuit, and a time-series difference between the two signals is calculated by a subtraction circuit. Here, since physical changes due to disturbance factors are applied to both differential infrared sensors at the same time, small absolute value signals from both absolute value circuits are also output at the same time, so the time series difference between the two absolute value signals is almost negligible. Becomes zero. That is, noise caused by external factors is canceled out twice by the pair of detection elements in each sensor and the subtraction circuit, and the output from the subtraction circuit becomes almost zero, so that no malfunction occurs as a detection device. On the other hand, when a moving object such as a human body crosses the detection area, a total of four infrared detection elements in a pair of differential infrared sensors move in a direction parallel to the moving direction of the moving object to be detected. Since they are arranged in a line, the detection signals from each infrared detection element are output sequentially in a time-division manner with a time delay due to the movement of the moving object, so they are not canceled out, and the outputs of these two sensors are individually Even if the time-series difference between the two signals converted into absolute values is calculated using the absolute value circuit of can be reliably detected.

<Example> Hereinafter, preferred examples of the present invention will be described in detail based on the drawings.

As shown in FIG. 1 and FIG. 2 showing one embodiment, a pair of detection elements 6a, 6 with different polarities are used.
Two differential infrared sensors 6 and 7 are provided in which differential infrared sensors b, 7a and 7b are connected, and both differential infrared sensors 6 and 7 are connected as shown in FIG.
The detection elements 6a, 6b, 7a, and 7b are arranged in a row parallel to the direction of movement of the moving object to be detected, which is indicated by an arrow, in close proximity to each other.
As the infrared sensors 6 and 7, it is preferable to use a pyroelectric element, a thermistor bolometer, a thermocouple (thermo panel), etc.; The elements 6a, 6b, 7a, 7b may be arranged in a line and installed internally, and in this case, four detection elements 6a, 6
The arrangement of b, 7a, 7b is +, -, +, - in polarity.
However, it may be +, -, -, or +. Furthermore, each 2
The differential connection of the detection elements 6a, 6b, 7a, 7b may be either series connection or parallel connection.

The optical system 8 focuses radiant energy in a predetermined detection area onto each of the detection elements 6a, 6b, 7a, and 7b. ,6b,7a,
7b may be provided, or the detection area may be made into a multi-area by using a split optical system such as a split mirror, or may be made into a single area by using a single optical system. .

Then, detection signals obtained by converting changes in incident energy into electrical signals in each of the infrared sensors 6 and 7 are amplified in amplifier circuits 8 and 9, respectively, and then converted into absolute values in absolute value circuits 10 and 11. . The output signals of both absolute value circuits 10 and 11 are subtracted by a subtracting circuit 12, and a level determining circuit 13 determines whether or not the output signal level of the subtracting circuit 12 is higher than the detection level. In certain cases, an activation signal is output from the level discrimination circuit 13 and the output circuit 14 is driven.

Next, the operation of the above-mentioned embodiment device is explained in Figs. 3 to 5.
This will be explained with reference to the figures.

First, when a moving object, for example a human body, crosses the detection area, each detection element 6a, 6b, 7a, 7b
From there, detection signals are sequentially output with a time delay due to movement, as shown in FIGS. 3a to 3d. In this figure, each detection element 6a, 6b, 7a,
The case where the polarity of 7b is arranged as +, -, +, - is shown. Each infrared sensor 6, 7 outputs a signal as shown in FIG. and from each absolute value circuit 10, 11,
A signal converted into an absolute value is output as shown by h,
The subtraction circuit 12 calculates the time-series difference between the two absolute value outputs, resulting in a signal output as shown in FIG. 3i.
This output signal is a waveform in which the output signals of the four infrared detection elements are simply converted into absolute values and output in a time-division manner without any subtraction, and this output signal is as shown in Figure 5. , level discrimination circuit 13
It is determined whether or not the detection level is higher than the detection level shown by the dashed-dotted line set in advance. As shown in the figure, if the detection level is higher than the detection level, the level determination circuit 13 outputs an activation signal and the output circuit 14 is driven,
An alarm output is issued and automatic doors are opened and closed.

In addition, when a sudden temperature change occurs on the lens surface or mirror cover surface of the optical system 1 due to disturbance light and wind, each detection element 6a, 6b, 7a, 7b responds to the change in incident energy. 4a from each detection element 6a, 6b, 7a, 7b.
Detection signals are simultaneously output as shown in d.
These simultaneously output detection signals cancel each other out, and from each infrared sensor 6, 7,
As shown in FIG.
A small signal is output due to variations in b, 7a, and 7b. After this output signal is amplified by amplifier circuits 8 and 9, respectively, it is converted into an absolute value by absolute value circuits 10 and 11, and from both absolute value circuits 10 and 11, a fourth
As shown in Figures g and h, these output signals are output as small signals of the same polarity, and the time-series difference between these two output signals is calculated by the subtraction circuit 12, so the signal output of the calculation circuit 12 is as shown in Figure 4 i. As shown in , it becomes almost zero.
In this way, for simultaneous inputs due to disturbances, etc.,
Since each infrared sensor 6, 7 and the subtraction circuit 12 cancel each other out twice, even when the disturbance is large, the output signal level of the subtraction circuit 12 will not exceed the detection level of the level discrimination circuit, preventing malfunctions. This can be reliably prevented.

It should be noted that the present invention is not limited only to the above embodiments, and it goes without saying that various embodiments are possible without departing from the scope of the claims. For example, in the embodiment described above, a case is described in which two infrared sensors 6 and 7 are provided, but more than two infrared sensors 6 and 7 may be provided. However, the number needs to be a multiple of 2. Alternatively, one of the absolute value circuits 10 may convert the values into positive absolute values, and the other absolute value circuit 11 may convert the values into negative absolute values, and the calculation may be performed such that the results are added and subtracted as a result.

<Effects of the Invention> As detailed above, according to the moving object detection device of the present invention, two differential infrared sensors are provided in combination, and after converting the detection signals of both sensors into absolute values, Since the configuration is configured to calculate time-series differences, energy that is input at the same time, such as noise due to disturbance factors, can be canceled out twice by each infrared sensor and the subtraction circuit. Noise can be almost eliminated, and even large disturbances can be suppressed to below the detection level, thereby reliably preventing malfunctions.

[Brief explanation of drawings]

1 to 5 show an embodiment of the moving object detection device of the present invention, FIG. 1 is a block diagram, FIG. 2 is an explanatory diagram of the infrared sensor in FIG. 1, and FIG. 3 is a
~i is a waveform diagram of the operating voltage of each part when a moving object is detected, Figures 4 a to i are waveform diagrams of the operating voltage of each part when disturbance noise is detected, and Figure 5 is an explanatory diagram of the detection level. FIG. 6 is a block diagram of a conventional device, FIG. 7 is an explanatory diagram of the infrared sensor of FIG. 1, and FIGS. 8 a to 8 d are waveform diagrams of operating voltages of various parts of FIG. 1. 6, 7...Differential infrared sensor, 6a, 6b,
7a, 7b...Infrared detection element, 8...Optical system,
10, 11...absolute value circuit, 12...subtraction circuit,
13...Level discrimination circuit.

[Claims]

1 In a zirconium-based alloy cladding tube, the +
A zirconium-based alloy cladding tube characterized in that the concentration of a metal having a valence of 1, +2, or +3 is higher than the concentration of a metal having a valence of 10 μm or more from the outer surface. . 2 In a method for manufacturing a zirconium-based alloy cladding tube, in a downstream process after hot rolling, high-energy ions of a metal having a valence of +1, +2, or +3 are irradiated onto the outer surface of the cladding tube, and the metal ions are A method for manufacturing a zirconium-based alloy cladding tube, characterized by forcibly dissolving the zirconium matrix into a solid solution in the zirconium matrix near the outer surface of the cladding tube. 3 In the manufacturing method of zirconium-based alloy cladding tube, +1, +2, or +3 in the hot rolling process.
A method for manufacturing a zirconium-based alloy cladding tube, characterized by providing a metal layer having a valence on the outer surface of the cladding tube, and repeating rolling and annealing.