JPS6115036B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a capacitance-balanced human body detector (commonly known as a man-day detector) which is equipped with an antenna having a ground capacitance in front of the elevator door, and uses an AC bridge including the antenna to detect a human body during the elevator door closing operation. ) relates to elevator door safety devices.

Elevators are equipped with various safety devices to prevent elevator users from being injured by the closing doors during the closing operation. One of these devices is a capacitance-balanced human body detector (hereinafter simply referred to as a human body detector).

A conventional mandaytector will be explained below with reference to FIG.

In Fig. 1, A ₁ and A ₂ are a pair of antennas placed apart from each other in the vertical direction along the front edge of the elevator door, and C ₁ and C ₂ are respectively placed between them and the ground.
It has a capacity of The antenna also has C ₃ ,
It has a capacity of C ₄ and is normally set to satisfy the formula C ₁ ×C ₄ =C ₂ ×C ₃ . 2 is an AC oscillator whose voltage is C ₁ ~ through the shield plate S and the ground.
Added to C ₄ . 3 is an AC amplifier, 4 is a rectifier circuit, 5 is a DC amplifier circuit, and 6 is an output element.

Now, when the elevator door is closing, if someone approaches, the capacitances C ₁ and C ₂ between each antenna A ₁ and A ₂ and the ground will change, causing the AC bridge circuit to become unbalanced. This causes an AC signal to appear between antennas A ₁ and A ₂ .
This signal is amplified, rectified, and amplified by an AC amplifier 3, a rectifier circuit 4, and a DC amplifier circuit 5, respectively, and energizes an output element 6 (for example, a relay). When the output element 6 is energized, a reopening signal (not shown) is issued to the elevator door, thereby preventing a person from getting caught in the door.

In this type of method, it is necessary to amplify at a high magnification the unbalanced output of the AC bridge circuit, which is extremely weak due to the proximity of a human body, and at the same time to compensate for the unbalanced output due to the influence of the ambient temperature of the equipment, dust, etc. This requires complex feedback circuits and delay circuits. In such a mandaytector, the circuit for unbalanced output correction mentioned above is mainly composed of semiconductors, so the stability of the entire device and the shape and structure of the elevator door may change due to the temperature characteristics of the correction circuit components. There was a demand for improvement of the entire device from the point of view of adaptability.

However, the front end of the elevator door (antenna mounting part) is often ordered by customers for its design.
In many cases, customer requests cannot be met due to the dimensions of the antenna shape and the mounting location.

The object of the present invention has been made in view of the above-mentioned points. By processing the judgment on whether or not to use a microcomputer, (1) improved detection accuracy, (2) improved reliability as various correction circuits are no longer required, and (3) cost due to the use of a 1-chip microcomputer. (4) To provide an elevator door safety device that has the advantage of being able to cope with changes in antenna shape and position due to design reasons on the front of the door by changing data in the software memory. .

The present invention will be explained below with reference to an embodiment shown in FIG. In FIG. 2, the same symbols and numerical values as in FIG. 1 indicate parts equivalent to those in FIG. 1. In FIG. 2, an unbalanced output when a human body is detected during a door closing operation is amplified by an AC amplifier 3, converted into a digital value by an A-D converter 7, and then input to a microcomputer 8. 9
is an external signal input section, which receives signals such as the ambient temperature and the position of the door when it is opened and closed.

Next, the principle of operation of the present invention will be explained with reference to FIGS. 3 and 4. The microcomputer 8 reads the output of the A-D converter 7 into the RAM, and calculates the difference Q between the value read last time and the value read this time. Next, information such as the position of the door and the ambient temperature is read into the RAM from the external signal input section 9, and Q is corrected based on the values. The change in Q per unit time is calculated for this corrected Q, and if the value is equal to or greater than a certain value, a door open signal is output. Furthermore, even if the change in Q per unit time is small but the absolute value of Q is large (when the elevator user is touching the front of the door), a door open signal is output as shown in FIG. 4. The program then returns to starting point A and runs the program endlessly.

FIG. 5 shows a modeled example of the sensitivity (balanced output) of the Monday detector when the door is simply opened and closed. Even if the balanced output of the mandaytector varies as shown in the diagram above due to vibrations during the opening/closing operation of the elevator door, by inputting the position information to the microcomputer 8, the relationship between the position and the correction amount can be determined in advance in a non-volatile manner. By writing it into memory, etc., and correcting it using position information, an even more stable Monday Techter can be realized. Similarly, changes in the balanced output due to temperature and humidity can be corrected by inputting the temperature and humidity into the microcomputer 8, allowing for extremely stable operation.

As described above, according to this proposal, by adopting a microcomputer as the main part of the device, a stable and highly reliable mandaytector can be realized with a simple circuit configuration that omits the various correction circuits found in conventional systems. In addition, cost reduction can be expected due to the use of a one-chip microcomputer, and an elevator door safety device can be provided in which disturbance correction can be processed using software.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a conventional door safety device, FIG. 2 is a configuration diagram of a door safety device showing an embodiment of the present invention, and FIGS. 3 and 4 are flowcharts for explaining the present invention. FIG. 5 is a model example of the sensitivity of the door safety device according to the present invention. A ₁ , A ₂ ... antenna, 2 ... oscillator, 3 ...
AC amplifier, 6...output element, 7...A-D converter, 8...microcomputer, 9...external signal input section.

Claims (1)

[Claims] 1. A detection mechanism consisting of an AC bridge including a pair of antennas, each with ground capacitive coupling, used to detect a human body during elevator door closing operation, and converting the unbalanced output of the AC bridge of this detection mechanism into a digital value. The A/D converter sequentially receives the converted digital value, elevator door position information, and ambient temperature information, and uses these information to correct the unbalanced output of the AC bridge. An elevator door safety device comprising: a microcomputer that controls elevator door opening according to changes in an unbalanced output value.