JPS5822283A - Detector for abnormality of elevator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to abnormality detection in elevators, and more particularly to an abnormality detection device suitable for elevators equipped with a pulse generator according to the travel distance of the elevator.

If an elevator control device malfunctions for some reason, it may cause an abnormal speed increase or deceleration depending on the type of failure, which is extremely dangerous, so it is important to detect this problem immediately and ensure safe operation. No.

A conventional method for such a case will be described by taking an AC elevator using an induction motor as a drive source as an example. To control the speed of an AC elevator, an anti-parallel connected thyristor is inserted into the 2nd or 3rd phase of the primary side of the induction motor, and the phase control of this thyristor controls the primary voltage of the induction motor to increase the driving torque. a drive torque control element to control;
The output of a rectifier circuit including a thyristor is supplied to the induction motor, and a braking torque control element is used to control the DC braking torque of the induction motor by controlling the position of the thyristor. A method is adopted in which the driving force and braking force of the induction motor are controlled by speed feedback according to the deviation between the reference speed command and the actual speed. In such a control system, if the thyristor or the like as the torque control element fails, the elevator will perform the following abnormal operation.

For example, when the elevator is operating in an upward direction and the load inside the car is light, or when the elevator is operating in a downward direction and the load inside the car is heavy, the thyristor on the drive torque control side is non-conducting and the rated voltage is applied to the motor. In the event of a failure in which no pressure is applied, the elevator speed gradually increases due to the unbalanced torque determined by the difference between the weight on the car side and the weight on the counterweight side. Even if this speed exceeds the synchronous speed of the electric motor, no regenerative braking torque is generated because a predetermined voltage is not applied to the electric motor, and therefore the elevator accelerates to a dangerous speed exceeding the rated speed.

In addition, in the case of a failure in which the thyristor on the braking torque control side remains conductive and behaves like a diode that cannot perform gate control, an excessive DC braking current flows to the motor, generating a large braking torque, and the elevator - will suddenly decelerate, giving passengers an abnormal shock.

In addition, even if a combination of malfunctions of the thyristors that control the driving torque and braking torque occurs, or a malfunction of the device that controls these thyristors, the elevator may operate abnormally in the same way as described above.

Conventionally, in such cases, the following method is used:
Performed fault detection.

First, in the case of a failure in which the motor speeds up without voltage being applied, the current flowing through the motor is detected, and if the current is zero, the power is immediately shut off and an electromagnetic brake is applied to stop the motor.

However, since the driving torque and braking torque are continuously controlled over the entire speed range, there always occurs a period in which the current is zero at the switching point of these torques. Therefore, detection by the above method must be ignored during the torque switching period.

Therefore, the above-mentioned failures within these periods cannot be detected.

Next, if the thyristor on the braking torque control side fails and sudden deceleration occurs, the upper limit value of the braking current is detected, and if the current exceeds this value, it is considered an abnormality, the power is cut off, and the electromagnetic brake to stop it.

In this case, the electromagnetic brake torque is considerably smaller than the current braking torque at the time of the above-mentioned failure, so even if the failure is detected and stopped using this method, the shock to passengers can be kept to a smaller level than when stopping with all DC braking. can.

However, in the above method, due to variations in the load and torque characteristics in the motor range and the detection characteristics of the current detector, the upper limit value for detecting abnormalities in the braking current is set slightly larger than the upper limit value during normal control. Therefore, even if an abnormality occurs, the detector does not operate immediately and cannot perform sufficient detection.

As described above, the conventional method has the drawback that abnormal operation of the elevator cannot be sufficiently detected and a detector is required for each faulty element.

Therefore, a method is known in which the actual speed of the elevator is monitored and the actual speed is compared with a set value to detect an abnormality. However, since the elevator speed varies depending on the load, the set value needs to have some margin. For this reason,
There was a problem that abnormality detection was delayed.

An object of the present invention is to provide an abnormality detection device that can quickly detect most abnormalities in an elevator, thereby realizing a highly safe elevator.

The feature of the present invention is that an abnormality in the elevator is detected when a change element that changes according to the difference in the actual speed of the elevator between a plurality of points in time exceeds a permissible value.
The system is designed to immediately detect an abnormality before it reaches abnormal speed due to a failure or the like. This change factor can be, for example, per unit time, and in the embodiment, this speed change rate will be described in detail as an example, but it may also be a value simply proportional to the speed difference.

In addition to the above-mentioned objects and features, the present invention also realizes a highly accurate device using digital calculations using elevator running pulses, and this point will be explained in detail in the following embodiments.

FIG. 1 is a detailed explanatory diagram of the present invention, in which FIG. 1B is a velocity curve diagram and FIG. 1B is an acceleration curve diagram.

In the figure, V is the velocity curve at normal times, and av is the acceleration curve at that time.

Assume that the speed curve V is abnormally accelerated as shown in the speed curve v1 due to a failure of the control device.

In this case, the conventional method of comparing with the set value S2 cannot detect an abnormality up to 0 point, and even with the method of comparing with the set value S1 according to the operating condition, the abnormality cannot be detected up to 0 point. Can not do it.

In the present invention, as described above, the speed change rate at that time, that is, the acceleration av, is determined and monitored.

Therefore, for example, even if a certain tolerance value PT is set and an abnormality is detected by comparing it, it can be detected immediately with a zero point. As will be understood from this, according to the present invention, an abnormality in an elevator can be detected more quickly than in the conventional method. In addition, in the present invention, if the actual acceleration is simulated and the upper and lower limits are set as permissible values of acceleration as PH and PL, the detection speed can be further increased. In this case, an abnormality can be detected instantaneously at 0 point.

As described above, according to the present invention, an abnormality in an elevator can be detected extremely quickly. In particular, since abnormalities can be detected at an early stage when abnormal speeds are likely to occur in the future, this is extremely effective in improving elevator safety. Furthermore, if it is taken into account that elevator failures will ultimately appear in the speed, the present invention can quickly detect most abnormalities.

The present invention will be explained below using specific examples.

FIG. 2 is a block diagram of an elevator control device to which the present invention is applied.

An elevator seat 1 and a collar/tower weight 2 are suspended from a sheep 4 via a rope 3 in a hanging manner.

The sheep 4 is connected to an elevator-driving three-phase induction motor 6 and an electromagnetic brake 7 via a reduction gear 5, and a three-phase AC speed generator 8 is connected to the induction motor 6.

The output voltage and frequency of this AC speed generator 8 are proportional to the rotation speed of the electric motor 6. Therefore, this output voltage is converted into a signal by the waveform shaping circuit 13 and inputted to the elevator control computer 14.

This computer 14 is composed of a microcomputer as shown in FIG. 4, and detects the running position of the elevator by integrating the pulses, and at the same time calculates a speed command. Further, the rectified voltage of the speed generator 8 is taken out from the circuit 13 and inputted to the phase shifter 15 to control the driving force and braking force of the electric motor 6.

R,, 'f', 8 is a three-phase AC power supply, main contact circuit 17
Switching between raising, lowering, maintenance operation 9 and normal operation is performed by a combination of switches, and is connected to a thyristor control device 16. Here, the thyristor control device 16 is composed of a driving torque control element and a braking torque control element using a thyristor or a combination of a thyristor and a diode, and these thyristors are controlled by the phase shifter 15.

This phase shifter 15 inputs the speed command 18 from the elevator control computer 14 and the speed feedback signal to perform feedback control. This feedback control allows the elevator passengers 1 to operate at a speed similar to the speed command 18 generated by the computer 14.

The speed command 18 is a command that increases over time during acceleration, and decreases during deceleration in response to the deceleration position.

In other words, the time required to obtain the acceleration command is
The position signal necessary for the deceleration command is calculated by counting the position signal of the waveform shaping circuit 12 and the pulses of the speed generator 8, and every time a predetermined number of pulses of the internal clock and the speed generator 8 are counted. , or every time the waveform shaping circuit 12 generates a position signal, interrupts the computer 14 and reads speed command data stored in a ROM (read only memory) of the computer 14, which will be described later.
This is converted into an analog quantity using a D/A converter and shown in Figure 3 (a).
) is set as a command that increases and decreases stepwise, and is further smoothed by a smoothing circuit to create a speed command as shown in FIG. 3(b).

Here, the above-mentioned position signal is only used for correcting the deceleration pattern, and is detected by the position detector 10 attached to the car 1.
11 crosses a shield plate provided in the tower, a signal is obtained via the waveform shaping circuit 12.

The computer and its peripheral devices are shown in the dashed line in FIG. Microprocessor (abbreviated MPU)20. A timer 33, a programmable counter-timer element (PTM for short) 2 that informs the MPU of a clock and a specific time interval that determines the timing of operation of this MPU.
2. Peripheral interface (P) for exchanging digital external signals with the microcomputer 14
IA) 23, 24, 25, ROM (read only memory) 26, M in which the operation manual of the MPU 20 is written
RA used for temporary storage as PU200 work area
It consists of an M (random access memory) 27, a data bus 28 for exchanging data between elements, and a control path 29 for selecting addresses and elements of the memory and exchanging clocks, interrupt signals, etc.

Note that the PTM 22 is usually called a programmable timer module, and here, the pulse from the AC speed generator 8 is input, the content of the counter is subtracted, and when the pulse enters after the counter reaches zero, the maximum value is reached. The value indicates the value.

The contents of this color can be read out by the FiMPU 20 at any time.

The position signal from the waveform shaping circuit 12 is input to the PIA which is set to receive a digital signal via the input/output device 32.
23. The speed command 18 is outputted via a D/A converter 30 and a filter circuit 31 that convert a digital signal output from the PIA 24 into an analog signal. Inputs from the operation panel of the elevator maintenance personnel and the elevator control circuit 19 (FIG. 1) are also input to the PIA 23 via the input/output device 32.

With such a circuit configuration, the elevator is controlled by a microcomputer.

Elevator abnormality detection is based on the operating principle described above, and the elevator is controlled by comparing the allowable speed change rate stored in the microcomputer 14 (7) ROM 26 with the elevator actual speed change rate. It is possible to detect whether the device is normal or not. However, here, in order to facilitate understanding and reduce the load factor on the computer, a case will be described in which the abnormality detection circuit 33 is configured with dedicated hardware. The configuration and operation diagrams of this circuit 33 are shown in FIGS. 5 to 7.

FIG. 5 shows an embodiment of a circuit that detects the interval time of the output pulses of the waveform shaping circuit 130PG shown in FIG. In the figure, 51 is a lock signal equivalent to the output signal of the clock 21 that determines the operation timing of the MPU 20 in figure g4. 52 is an inverting circuit, 53 is an AND circuit, 54 is a time delay element, 55°61.62 is a counter, 56, 57Il
i latch, 58 is the PG output pulse signal, and 59.60 is the output of the latch.

On the other hand, detection of the rate of change in the actual elevator speed is carried out as in the downtown area.

When the counter 55, which starts counting at the falling edge W of the clock signal 51, reaches a certain value, it issues an output signal, and when the output signal of the inverting circuit 52 is issued, that is, the falling edge of the clock signal 51 is kept constant. When the number of times has been counted, the AND circuit 53 issues an output signal. When this output signal is issued, the counter 55 is reset,
Start counting again. Therefore, this circuit generates an interrupt signal 71 of a fixed time (for example, TI) shown in FIG.

On the other hand, the counter 62 that detects the fall of the PG output pulse signal 58 starts counting when the PG output pulse signal 58 falls, and when the next PG output pulse signal falls, a signal is output from Q2 of the counter 62. to end the count. Furthermore, since this counter 62 is reset by the interrupt signal 71, from the first fall of the PG output pulse signal 58 after the interruption of the interrupt signal 71,
Outputs the output signal until the next falling edge. The counter 61 is set by this signal and the fall of the clock signal 51. This signal becomes points A to D shown in FIG. Therefore, the counter 61 counts the clock signal 51 shown in FIG. 6 from point A to point B and from point 6 to point 0. This counter 61 is also reset by the interrupt signal 71, so the count values at points A and 0 are reset to, for example, $0000 at point A, and the count starts from the first fall of the PG output pulse. However, at point B it is $0O.
At the FFND point, a value of $0OFO is counted by the counter 61.

This count value is input to the launch 56 gated by the interrupt signal 71. Similarly, the latch 57 reads the count value from the latch 56 in response to the interrupt signal 71.

Here, latch 56, latch 57, counter 61.62
The gate signal and reset signal of time delay element 5
The data is inputted one by one with a delay of 4. therefore,
The contents of the latch 59.60 are shifted by one, e.g.
The output 59 of the latch 56 is the value $0OFF at point 1B, and the output 60 of the latch 57 is the value $00FO at point D.

According to the circuit configuration described above, the contents of the latch 59.6
0 is the interval time of PG output pulses.

Here, the latch contents 59 are TPLl, the latch contents 6
If 0 is TPL2, the rate of change in the actual speed can be determined as the difference between TPLI and TPL2 divided by the interrupt interval time T1 of the interrupt signal 71. Therefore, the above TPL1 and TPL2 are input to the computer 14 via the PIA 25, the rate of change of the actual speed is calculated, and compared with the allowable value written in advance in the ROM 26 inside the computer 14. If the allowable value is exceeded, the failure occurs. Anomaly detection can be performed by setting a flag.

According to this, since division with a decimal point is performed by the microcomputer, there is a calculation time delay of about 100 m5, but there is an effect that the above-mentioned calculation process of TPL1 and 'I'PL2 is unnecessary.

However, here, a case will be described in which the above abnormality detection process is also performed within the abnormality detection circuit 33. FIG. 7 shows a circuit configuration for this purpose, which is realized here without using the division function. Therefore, even when processing with a computer, the processing becomes easy if this method is used.

In the figure, 81 is a subtracter, 82 is a multiplier, 83 is a multiplier, and 84U is a comparator.

In the circuit described in FIG. 6, the difference between TPLl and TPL2 is determined by the subtracter 81, the product of TPLI and TPL2 is determined by the multiplier 82, and the product of TPLI and TPL2 is added to the rate of change of the actual speed. Subtraction and multiplication are performed by a multiplier 83 that multiplies the allowable value. Then, by comparing the outputs of the subtracter 81 and the multiplier 83 with the comparator 84, if the output of the subtracter 81 is dog, it is determined that the rate of change of the actual speed has exceeded the allowable value, and an abnormality detection signal is sent. Output AN.

The reciprocal of TPL1 and TPL2 corresponds to the speed, and when the allowable value is PT, the following relationship holds true.

Therefore, if we transform this equation (1), we get 1,', TPL2-TPLI>PT(TPLI・TPLI2
)...(2).

Therefore, the above circuit eliminates the need for division by executing equation (2).

Therefore, in the figure, swl is a contact that is turned on during acceleration, SW2 is a contact that is turned on during constant driving, and 8W3 is a contact that is turned on during acceleration. Tolerance value PT2 during constant running
, by setting the allowable value PT3 at the time of deceleration, Figure 1 (2
), it is possible to detect abnormalities according to the condition of the elevator.

Furthermore, the increase value (PH) and the lower limit value (PL) of the allowable value are set for the husbands of the multipliers 83, 85. By setting standard tolerance values for 83, 85, and 86, and comparing and judging the calculated values with a predetermined dead area in the comparator 84, as shown in Fig. 1 (5), , upper limit (PH) and lower limit (P L
) can also be determined to be abnormal.

By inputting the signal AN detected in this manner to the computer 14 via the PIA 25, the computer 14 operates the elevator protection device to ensure the safety of passengers.

In the embodiment described above, a dedicated abnormality detection circuit 33 is provided outside the computer 14. It is possible to reduce the load factor of the computer 14, and also to detect abnormalities including abnormalities of the computer 14.

Therefore, the abnormality detection signal AN is transmitted to the computer 1.
In addition to inputting the signal AN into the computer 14, the safety of the elevator can be ensured even in the event of an abnormality in the computer 14 by directly operating a safety device such as a brake using the signal AN.

However, the present invention is not limited to this more specific embodiment, and for example, the processes shown in FIGS. 5 to 7 can be easily executed by a program of the computer 14. In this case, although the hardware for abnormality detection can be reduced, its effectiveness is also lost.

Furthermore, as described in FIG. 6, instead of measuring only one PG output pulse interval time during the interrupt interval of the interrupt signal 71, for example, three PG output pulse interval times are detected and the PG output pulse interval time is measured. Among them, the PG output pulse interval time excluding large and small ones is calculated, and after the next interrupt signal 71 is input, the same is compared to prevent malfunctions due to elevator vibrations, etc. , stable abnormality detection can be performed.

Further, in the above embodiment, highly accurate detection is possible by measuring the interval time of PG output pulses using a clock signal in order to detect the speed. However, the present invention is not limited to this, and the actual speed can also be easily detected by counting the number of PG output pulses 58 generated during the interrupt signal 71, as shown in FIG.

As described above, according to the present invention, an abnormality in an elevator can be detected quickly. Therefore, it can greatly contribute to improving elevator safety.

[Brief explanation of the drawing]

Fig. 1 is a detailed explanatory diagram of the present invention, Fig. 2 is a block diagram of an elevator control device to which the present invention is applied, Fig. 3 is an explanatory diagram of a speed command generation method, and Fig. 4 is a computer and its surroundings. The circuit diagram, FIG. 5 is an example of the actual speed detection section of the abnormality detection device according to the present invention, FIG. 6 is an explanatory diagram of the operation of FIG. 5, and FIG.
The figure is an example diagram of the abnormality determination section of the abnormality detection device according to the present invention,
FIG. 8 is an explanatory diagram of another speed detection method. DESCRIPTION OF SYMBOLS 1... Car, 14... Computer and its peripheral circuit, 15... Phase shifter, 33... Abnormality detection circuit, 51
... clock signal, 58 ... running pulse, 55,
61.62...Counter, 56,57...Latch,
81... Subtractor, 82... Multiplier, 83, 85, 8
6... Multiplier, 84... Comparator, SW1 to SW3.
・・Elevator operating condition 1st z (A) l atsushi 22 taku 3 concave (υ) face closure 412] 纂 S 口口等 [] Iρρ06 $tpoip 10//6
Jρθfθ is also 7 mouths

Claims (1)

[Claims] (1) In an elevator that runs between multiple floors, a variable element that changes depending on the speed difference of the elevator between multiple points in time; An elevator abnormality detection device characterized by detecting an elevator abnormality. 2. The elevator abnormality detection device according to claim 1, wherein the change factor is a speed change rate determined from the speed difference between the plurality of points per unit time. 3. In the elevator equipped with a means for generating pulses according to the traveling distance of the elevator, the pulse interval time at a first point in time and the pulse at a second point in time after a unit time from this first point in time. Claim 2 wherein the speed change rate is calculated from the difference with the interval time.
Elevator abnormality detection device described in Section 1. 4. The elevator according to claim 3, wherein the pulse interval time is an average value of a plurality of pulse interval times.
Anomaly detection device. 5. The elevator abnormality detection device according to claim 1, wherein the permissible value is changed depending on the operating condition of the elevator. 6. In the elevator equipped with a means for generating pulses according to the travel distance of the elevator, the number of pulses within a predetermined time at a first point in time and a second point in time after a unit time from this first point in time. Claim 2, wherein the speed change rate is calculated from the difference between the pulse number and the pulse number.
An abnormality detection device for an elevator as described in Section 1. 7. The elevator according to claim 1, which is equipped with a digital computer for controlling the elevator, and is configured to detect abnormalities in the elevator by a dedicated circuit provided separately from the computer. Anomaly detection device. 8. An elevator abnormality detection device according to claim 1, comprising a digital computer for controlling the elevator, wherein the computer is configured to detect abnormalities in the elevator.