JPH0319154B2 - - Google Patents

Description

Detailed Description of the Invention Technical Field of the Invention The present invention relates to an elevator speed control device, and more particularly to an elevator speed control device equipped with a detector that can detect the elevator speed with high accuracy over the entire speed range. It is.

In recent years, systems have been put into practical use that digitally detect the car speed of an elevator or the rotational speed of a hoist motor. This method detects the actual speed of the car by generating movement pulses corresponding to the movement amount and direction of the car and counting them at predetermined intervals.

Such a movement pulse generator is disclosed in, for example, Japanese Patent Laid-Open No. 72583/1983. The travel pulse in this method is generally directly connected to the drive sheave of the hoist or the speed governor sheave, or a rotating disk via a transmission mechanism such as a pulley, or a steel plate connected to the car. It is obtained from a disc that is directly connected to a sheave wrapped with tape or the like.
In addition, this type of disk has pores arranged at equal intervals around its periphery, and by detecting these pores optically or electromagnetically, pulses of frequency proportional to the rotation speed of the disk can be generated. I'm starting to get more.

In elevator speed control, when used for determining the deceleration position and position feedback control of speed commands in the deceleration area, the distance detection unit of the movement pulse is several mm.
However, when used for speed feedback control, the detection speed becomes an issue, and in the above-mentioned method of detecting speed by counting movement pulses that arrive within a predetermined time, the distance detection unit is 1 to 2 digits. Moreover, in a low speed region, the number of movement pulses generated per unit time decreases, so when detecting speed, the distance conversion value of one pulse must be further reduced. A travel pulse generator that satisfies this requirement requires high mechanical precision, and has not been put into practical use due to processing accuracy and cost. Therefore, at present, in order to increase the number of pulses generated in the low speed region, a method is used to increase the distance detection resolution per pulse by mechanical means such as a speed increasing coupling using a gear or a pulley. However, the device as a whole becomes extremely expensive.

Summary of the invention This invention solves the above-mentioned conventional drawbacks.
By counting the travel pulses in the high-speed region, and measuring the pulse interval of the travel pulses in the low-speed region and detecting the speed from the reciprocal, it is possible to avoid increasing mechanical accuracy even in the low-speed region. An object of the present invention is to provide an elevator speed control device that enables highly accurate speed detection.

Embodiments of the Invention Hereinafter, embodiments of the invention will be described based on the drawings.

1 and 2 show an embodiment of the elevator speed control device of the present invention, in which 1 is an elevator car, 2 is a counterweight, 3 is a main rope connecting the car 1 and the counterweight 2; Reference numeral 4 denotes a hoisting machine installed in the machine room, which has a sheave 5, on which the main rope 3 is wound, and by rotating the sheave 5 by the hoisting machine 4, the car And the counterweight 2 is raised and lowered in a hanging manner. Reference numeral 6 denotes a disc having fine holes 6a formed at equal intervals on its periphery, and a timing belt 9 is wound between a pulley 7 coaxially attached to the disc 6 and a pulley 8 coaxially attached to the sheave 5. This allows the rotation of the sheave 5 to be transmitted to the disc 6. 10 is a movement pulse generator that detects the pore 6a of the disk 6 and generates a pulse. quantity pulse signal 10a and a signal having a phase difference of 90° from this movement quantity pulse signal 10a (not shown)
A direction signal 10b is generated based on the relationship between the two signals and represents the direction of the car. The direction signal 10b becomes "H" when the car 1 moves in the upward direction, and becomes "L" when the car 1 moves in the downward direction.

The movement amount pulse signal 10a and the direction signal 10
b is applied to a speed detector 11, which receives a direction signal 10b and a movement pulse signal 10.
Calculate and detect the actual speed of car 1 based on a,
This is output as an actual speed signal 11a. 1
2 is a drive control device that controls the electric motor (not shown) of the hoisting machine 4, and this drive control device 12 includes the actual speed signal 11a and a speed command generation device that outputs the speed command at which the elevator should run. A speed command signal 13 from a motor (not shown) is input, and the electric motor of the hoisting machine 4 is controlled so that the speed of the elevator follows the speed command signal 13.

FIG. 2 shows details of the internal configuration of the speed detector 11, in which 20 and 21 are first and second pulses that generate sampling pulses 20a and _21a of predetermined frequencies ₁ and ₂ ( _1≫2 ), respectively. The sampling pulse generator 2, 22, is a counter that counts the movement pulse signal 10a from the movement pulse generator 10, and the counted value is stored in the memory 23. Trigger input terminal T of the memory device 23
A sampling pulse 21a from the second sampling pulse generator 21 is applied to the counter 22, and when the sampling pulse 21a changes from "L" to "H", the count value of the counter 22 is captured and stored, and then output. I'm starting to do that. 2
4 is a pulse width converter, which includes a NOT gate 24A, a resistor 24B, a capacitor 24C, and an AND gate 2.
This output pulse 2
4a to the reset input terminal R of the counter 22,
As a result, the counter 22 outputs the sampling pulse 2.
The movement amount pulse signal 10a is counted with a pulse period of 1a, and the output of the memory 23 indicates the maximum count value of the counter 22, which becomes the speed data of the elevator.

Further, 25 is a counter that counts the sampling pulses 20a of the first sampling pulse generator 20 and measures the pulse width of the movement pulse signal 10a. A pulse width converter 26 is connected in series between the input terminals T1.
The pulse converter 26 has a NOT gate 26A and a resistor 2.
6B, capacitor 26C and AND gate 26D
, which results in a movement amount pulse signal 10
The rising portion of a is converted into a pulse having a width sufficiently narrower than that of the sampling pulse 20a, and this output pulse is input to the counter 25 as a reset signal. 27 is a memory device that stores and holds the count contents of the counter 25;
This memory device 27 stores the counter 25 at the time when the movement amount pulse signal 10a changes from "L" to "H".
It is designed to import the contents of 28 is a reciprocal conversion decoder that detects the speed (low speed region) from the reciprocal of the content stored in the storage device 27, and a data table (not shown) in which a large number of speed data is stored in advance by multiplying the reciprocal of the measurement content by a predetermined coefficient. ), and by accessing the data table using the storage contents of the storage device 27 as address data, speed data corresponding to the storage contents is output.
Reference numeral 29 is a memory for storing data output from the reciprocal conversion decoder 28, and reference numeral 30 is a memory for storing the direction signal 10b input from the input terminal T2. Sampling pulse 2 from generator 21
Each data is stored and held at the time when 1a changes from "L" to "H". 31 is a constant setter that outputs speed data of a preset value; 32 is a comparator that compares the data from the storage device 23 with the speed data from the constant setter 31; both input data X, Y; (X is the data in the memory unit 23, Y is the data in the constant setter 31) When X≧Y, “H” is generated at the output, and when X<Y, “L” is generated at the output. There is. 33 is a selection circuit that selectively outputs the stored data of either one of the storage devices 29 and 30, and the output signal of the comparator 32 is applied to the selection input terminal S of this selection circuit 33; When the output of the comparator 32 is "H", the data stored in the memory 23 is selected;
When the signal is "L", data stored in the memory 29 is selected and sent to the output terminal 34, and the direction signal 10b of the memory 30 is sent to the output terminal 35. Note that the signal sent to the output terminal 34 corresponds to the actual speed signal 11a.

Next, the operation of this embodiment configured as described above will be explained.

When the speed command signal 13 is input to the drive control device 12, the drive control device 12 starts supplying current to the electric motor (not shown) of the hoisting machine 4 to obtain a rotation speed corresponding to the speed command signal 13. The electric motor is started, the sheave 5 of the hoisting machine 4 rotates, and the car 1 starts running. At this time, the rotation of the sheave 5 is transmitted to the disc 6 via the pulley 8, timing belt 9, and pulley 7, and when the car 1 is in upward operation, the direction signal 10b becomes "H" and the car 1
A movement pulse signal 10a is generated from the movement pulse generator 10 every time the movement is 0.1 mm. This pulse signal 10a is counted by a counter 22, and the count increases.

On the other hand, a sampling pulse 21a sent out from the sampling pulse generator 21 (see FIG. 3a)
At the time when the value changes from "L" to "H", the count contents of the counter 22 are taken into the memory 23 and held there. At the same time, the pulse width converter 24
A pulse signal 24a shown in FIG. d is sent out and applied to the reset input terminal R of the counter 22, thereby resetting the counter 22. Note that the count stored in the memory 23 is the number of movement pulse signals 10a that arrive between the sampling pulses 21a, and this corresponds to the actual speed of the car 1.

The operation of the pulse width converter 24 will now be explained with reference to FIG.

When the sampling pulse 21a becomes "H",
The output of the NOT gate 24A becomes "L" as shown in Figure 3b, and accordingly, the charge in the capacitor 24C gradually discharges through the resistor 24B as shown in Figure 3c, and the potential changes from the start of discharge to the AND gate. Since one input of the AND gate 24D is kept at "H" until the threshold voltage of the transistor constituting the transistor 24D is reached, the output of the AND gate 24D receives the pulse signal 24 shown in FIG. 3d.
a occurs. Next, when the sampling pulse 21a is inverted to "L", the output of the NOT gate 24A becomes "H", and the capacitor 24C begins to be charged through the resistor 24B with a time constant determined by both of them as shown in FIG. 3c. At this time, the potential of the capacitor 24C is low and has not reached the operating potential of the AND gate 24D, so no pulse signal 24a is generated in the pulse width converter 24. The pulse width of the pulse signal 24a can be made sufficiently narrower than the movement amount pulse signal by appropriately selecting the values of the capacitor 24D and the resistor 24B.

In this way, each time the sampling pulse 21a becomes "H", one pulse is generated from the pulse width converter 24, and the contents of the counter 22 are reset.

On the other hand, the counter 25 receives the sampling pulse 2 generated from the first sampling pulse generator 20.
0a is counted, and the movement amount pulse signal 1
The count contents of the counter 25 at the time when 0a is inverted from "L" to {H" are taken into the memory 27 and held. At the same time, the counter 25 is reset by the output pulse 26a of a pulse width converter 26 similar to the pulse width converter 24 described above. At this time,
Sampling pulse 20 taken into memory 27
The count value of a corresponds to the pulse width of the movement pulse 10a. Furthermore, by outputting the stored data in the storage device 27 to the reciprocal conversion decoder 28,
The speed data corresponding to the stored data is read from the data table, and this is used as the sampling pulse 2.
The time point when 1a changes from "L" to "H" is stored in the storage device 29. The speed data stored in this memory 29 indicates the actual speed of the car 1.

Further, the comparator 32 constantly compares the speed data in the memory 23 and the predetermined speed data from the constant setter 31, and if the speed data X from the memory 23 is smaller than the predetermined speed data Y (X<Y) Since the output of the comparator 32 becomes "L", when this output "L" is applied to the selection circuit 33, the selection circuit 3
3 selects the speed data in the memory 29 and outputs it to the output terminal 34. Along with this, the direction signal 10b stored in the memory 30 is also sent to the output terminal 35.

Speed data and direction signal 10 in the storage device 29
The drive control device 12 that receives the signal b controls the electric motor of the hoisting machine 4 to follow the speed command signal 13. Furthermore, when the condition of X≧Y is established in the comparator 32, the output of the comparator 32 becomes "H", so the selection circuit 33 receiving this output
3 is selected and outputted to the drive control device 12 together with the direction signal 10b stored in the memory 30. The electric motor of the hoisting machine 4 is then controlled so as to follow the speed command signal 13.

In this embodiment as described above, when the car speed is equal to or higher than a predetermined speed set by the constant setting device 31, the movement amount pulse 10a is counted according to a predetermined sampling time to detect the speed, and the speed is detected when the car speed is set at the predetermined speed. In the following cases, the pulse interval of the movement amount pulse signal 10a is measured by the counter 26 and the sampling pulse generator 20 to detect the speed. There is no need to reduce the units of generated pulses and the travel distance of the pulse generator, that is, there is no need to make the pulse generation mechanism mechanically highly accurate.
In addition to being advantageous in terms of processing accuracy, it is possible to obtain an elevator speed detector at a low cost.

In the above embodiment, a case was described in which the speed value obtained by directly counting the movement amount pulse signal and the predetermined speed value were compared by the comparator 32. A similar effect can be obtained by comparing the obtained speed values.
In addition, in the above embodiment, two types of detection speeds obtained by sampling pulses are sampled and selected, but in a digital calculation type drive control device using a microcomputer or the like, the counter 22 is directly used in each calculation cycle. The output of the reciprocal conversion decoder 28 may be taken in as input data and selectively processed using a predetermined processing program.

Effects of the Invention As explained above, according to the present invention, in the high speed region of the elevator, movement pulses are counted,
In the low-speed region, the speed is detected by measuring the pulse interval of the travel pulses, so even in the low-speed region, high precision can be achieved without reducing the mechanical accuracy of the travel pulse generation mechanism and the unit of the generated pulse. This has the advantage that speed detection becomes possible and the speed detection means can also be made inexpensive.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an example of the elevator speed control device of the present invention, Fig. 2 is a block diagram showing details of the speed detector in Fig. 1, and Fig. 3 is a block diagram showing various parts of the pulse width converter in Fig. 2. FIG. 1... Basket, 2... Counterweight, 3... Rope, 4... Winding machine, 5... Sheave, 6... Disc, 1
0...Movement pulse generator, 11...Speed detector, 12...Drive control device, 13...Speed command signal, 20, 21...Sampling pulse generator,
22, 25...Counter, 23, 27, 29, 3
0... Memory device, 24, 26... Pulse width converter,
28... Reciprocal conversion decoder, 31... Setting device, 3
2... Comparator, 33... Selection circuit.

Claims (1)

[Claims] 1. In a device that controls the speed of an elevator car using a speed command signal and an actual speed signal, one movement pulse generator generates pulses corresponding to the movement amount of the car, and counts the movement pulses within a predetermined time. and a first speed detection means for detecting the speed of the car, a second speed detection means for measuring the pulse interval of the movement pulse and detecting the speed of the car by reciprocal conversion of the measured value, and the first speed detection means for detecting the speed of the car. Alternatively, the output signal of the second speed detection means is compared with a predetermined set value, and when the output signal of the first or second speed detection means is equal to or higher than the set value, the output signal of the first speed detection means is determined. is less than the set value, comparing and selecting means outputs the output signal of the second speed detecting means as the actual speed signal, respectively.