JPH02231380A - Position detecting device for elevator - Google Patents

Abstract

PURPOSE:To accurately detect a position of an elevator, even when a pulse generates its waveform abnormal by a quantity of light changed due to a certain cause, by providing a maximum voltage detecting circuit of an input signal and a voltage divider, dividing an output of the detecting circuit, with an output of the voltage divider serving as the reference voltage. CONSTITUTION:A pulse generator 3, generating a pulse synchronized with movement of an elevator cage, is provided. This pulse generator 3 generates the pulse transmitted to an optical fiber 4 feeding a signal input. This input signal is compared with fixed reference voltage in a comparator 17 generating a square-wave pulse detecting a position of an elevator. Here providing a circuit 30 detecting a peak voltage signal of the light receiving pulse signal, a circuit (voltage divider) 36, adding in proportion to a signal of the peak detecting circuit 30 voltage, adding a predetermined gain, to the reference voltage serving as reference voltage of the comparator 17, is provided.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to an elevator position detection device.

(Prior Art) In recent elevator control devices, microcomputers are used to perform various elevator processes. This is to improve performance by speeding up processing and to make it easier to handle options by using a microcomputer. However, in elevator control equipment that uses a microcomputer, the The position of the elevator is detected using a pulse generator that generates pulses in synchronization with the movement of the elevator.

In addition, with recent advances in optical fiber technology, data transmission using optical fibers has become widespread, and optical fibers can now be applied to pulse generators. Optical pulse generators can also be used in elevator control equipment to achieve numerous effects. There is. One of them is that the pulse transmission is optical, so accurate position detection can be performed without being affected by noise. Furthermore, if the light emitting section is also provided in the control device, there is no need for an electric circuit in the pulse generator section, and wiring can be streamlined. On the other hand, the pulse generator part consists of a light emitting part, a light receiving part, and a slit part, but the light is attenuated due to the gap between the light emitting part and the light receiving part, and the amount of light received is reduced. Figure 2 shows a conventional light detection input circuit from an optical pulse generator. In the figure, 1 is a light emitting diode, 2 is a light emitting side optical fiber cable, 3 is a slit,
4 is a light receiving side optical fiber cable, 5 is a light receiving element, 7 is a first amplifier, 9 is a second amplifier, 18 is a voltage setting volume, 20 is a voltage comparator, 6, 8, 13, 14,
15. 19 each indicates a resistor. The light emitting diode 1 is always lit and continues to send light to the optical fiber 2. In the pulse generator section, the light received by the optical fiber is applied to the slit 3, and the light passing through the slit is input to the light receiving element 5 via the receiving optical fiber. In the light receiving element 5, a current flows through the light receiving element 5 according to the intensity of the received light, and the light is amplified by the first amplifier 7 with a gain corresponding to the resistor 6. The amplified pulse-like waveform is further input to a second amplifier 9 via a resistor 8, where it is amplified by a predetermined gain. It is then input to the input terminal I6 of the comparator 20 via the resistor l5. A voltage set by the variable resistor 18 is input to the comparator 20, and the voltage is compared with the above-mentioned pulse input to form a square wave pulse. FIG. 3 shows the waveforms of the above pulse input circuit.

22 is the output of the first amplifier, 23 is the output of the second amplifier, 24 is the adjustment input of the comparator, and 25 is the output of the comparator. As explained above, the pulse signal input via the optical fiber becomes a pulse that can be input to various counters etc. via the comparator.

(Problem to be Solved by the Invention) However, when using optical fiber light emitting diodes and the like in equipment, it is necessary to consider changes in the amount of light.

Also in the optical pulse generator, when the amount of light input to the light receiving circuit changes, the waveform changes and the waveform of the pulse changes. FIG. 3 shows an example of this change.

26 indicates the output of the second amplifier. As the amount of light decreases, the output voltage 24 of the variable resistor increases relatively, and the pulse signal output from the comparator changes due to the change in the amount of light, causing an abnormality in pulse detection.As explained above, However, when using a pulse generator that uses optical fiber, conventional light receiving circuits are affected by changes, making it impossible to obtain stable performance as an elevator position detection device, and this poses a problem when actually applied. Become.

The present invention realizes a pulse input device for an elevator that does not cause pulse abnormality even if the amount of light changes in a light emitting part or a part of a fiber.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a pulse generator that generates pulses synchronized with the movement of an elevator car, an optical fiber that transmits the pulses generated by this pulse generator, and an input signal sent from this optical fiber. Shiko's input signal and
In an elevator position detection circuit that detects the elevator position by generating a square wave pulse by comparing it with a constant reference voltage, a circuit is provided to detect the peak voltage signal of the received light pulse signal, and the peak voltage signal is proportional to the signal of the peak detection circuit. The present invention is characterized in that a circuit is provided which adds a voltage to which a predetermined gain has been added to the reference voltage and uses this as the reference voltage of the comparator. (Function) If the light intensity of the light emitting diode changes due to aging or voltage fluctuations, or if the optical attenuation changes due to some reason in the optical fiber cable that is transmitting it, the light intensity of the light receiving circuit will eventually change. Change. The amount of received light is input to the peak hold circuit, and the voltage at the time when the light is strongest is output from the peak hold circuit. When the amount of light changes, the above output voltage changes, and when the amount of light decreases, the above output voltage also decreases, A voltage proportional to the amount of light can be obtained regardless of whether the pulse is ON or OFF. A comparison circuit is used to convert the amount of change in the voltage into an ON/OFF pulse signal from an analog signal compared to the light. By correcting the proportional voltage change, the reference voltage can be made proportional to the optical signal input by changing the reference voltage in the same direction in response to changes in the amount of light, and as a result, the initial setting It is possible to maintain the specified duty. (Embodiment) FIG. 1 shows the configuration of an embodiment of the present invention. In the figure 3
0 is a peak hold circuit, 31 is a resistor 32. 35 is an operational amplifier, 33 is a diode, and 34 is a capacitor. Next, the operation of the present invention will be explained.

The light emitted from the light emitting diode 1 is transmitted through the optical fiber 2.
and a continuous signal of light through the rotating slit section,
The light is input to the light receiving element 5 via the optical fiber 4. In the light receiving element, a current proportional to the amount of light flows, and is amplified by the first amplifier 7 with a gain corresponding to the resistor 6.
Furthermore, it is further amplified via the second amplifier 9. The signal is then input to a comparator 17 via a resistor 15.

Further, the output signal of the amplifier is transmitted to a peak hold circuit 30.
is input. When the output signal is input to the operational amplifier 32 via the resistor 31, the capacitor 34 is charged via the diode 33. The voltage of the capacitor 34 is held until a higher input voltage is applied, and stores the maximum voltage of the optical signal pulse. The signal output in normal rotation through the operational amplifier 35 is divided into approximately 172 peak voltages of the input voltage by a voltage divider 36, and is input to the reference voltage input terminal of the comparator 17 through a resistor 19. ．． FIG. 4 shows operational waveforms when the amount of light changes, and the effects of the present invention will be explained. In FIG. 4, 37 is the optical reception signal waveform, 38 is the output voltage waveform of the peak hold circuit, and 39 is the starting point of change in the output voltage of the peak hold circuit due to a decrease in the amount of light. Reference numeral 40 indicates the output voltage waveform of the voltage divider 36 (same as the reference voltage of the comparator 17) obtained by dividing the peak hold voltage, and 41 indicates the digital norm signal waveform of the output of the comparator 17.

The light reception signal waveform 37 is a case where the amount of light received changes for some reason at point 39 and the light reception voltage becomes small. On the other hand, the output voltage 38 of the peak hold circuit 30 decreases from point 39 as the light reception signal 37 decreases. Furthermore, along with this, the gain is adjusted to about 172 and the duty of the pulse waveform is 50%, but due to the decrease in peak hold voltage, it decreases at the same rate, and the standard The voltage also drops. Therefore, even if the amount of light received decreases, the same duty as before can be maintained. By implementing the present invention, it is possible to realize a light receiving circuit for an optical pulse generator that maintains a constant duty ratio even if the amount of received light changes with a simple circuit configuration.

〔Effect of the invention〕

According to the present invention, in an elevator position checking device that uses optical fiber, even if the amount of light changes for some reason and the pulse waveform becomes abnormal, the elevator position can be accurately detected. By taking advantage of the advantages of applying the second method, it is possible to realize a high-performance elevator position detection device that is resistant to noise and does not require power supply wiring.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of the present invention, FIG. 2 is a configuration diagram of a conventional device, FIG. 3 is a conventional signal state diagram, and FIG. 4 is a signal state diagram of the present invention. 1... Light emitting diode, 2, 4... Optical fiber 3... Slit disk, 5 river photodiode, 3
0...Peak hold circuit, 36...Voltage divider. Agent Patent Attorney Noriyuki Ken Yudo Deshimaru Kendai

Claims (1)

[Claims] It has a pulse generator that generates pulses synchronized with the movement of the elevator car, and an optical fiber that transmits the pulses generated by the pulse generator, inputs a signal sent from the optical fiber, and receives the input signal.
In an elevator position detection circuit that detects the position of the elevator by generating a square wave pulse by comparison with a constant reference voltage, a maximum voltage detection circuit of the input signal and a voltage divider that divides the output of the detection circuit are provided, An elevator position detection device characterized in that the output of the voltage divider is used as the reference voltage.