JPS6348794B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a device for detecting the position of an elevator.

Recently, devices that digitally detect the position of an elevator car have been put into practical use. This detects the relative position of the car by generating movement pulses according to the movement amount and direction of the car and reversibly counting them. It is shown in the official gazette. This travel pulse is generally directly connected to the drive network wheel of the hoist or the speed governor, or is obtained from a rotating disc via a transmission mechanism such as a pulley.
It can also be obtained from a disk connected to a cage and rotated by a pulley around which a steel tape or the like is wrapped.
This disc has pores arranged at equal intervals around its circumference, and these pores can be detected optically or electromagnetically to obtain pulses with a frequency proportional to the rotation speed of the disc. It is.

This travel pulse is used for determining the deceleration position and position feedback control of the speed command in the deceleration area in elevator speed control, and the position detection unit is also 10 mm.
However, speed control near the stopping point requires a detection accuracy of about 1 mm due to landing accuracy.
A travel pulse generator that satisfies this requirement requires high mechanical precision, and has not been put into practical use due to machining accuracy and cost. Currently, specially shaped guide plates for position detection are installed in the hoistway of each stop floor.
In reality, this is detected electromagnetically and precise position/velocity conversion is performed to control the velocity near the landing position. Since these devices must be installed on each floor, the overall cost is quite high.

This invention improves the above-mentioned problem, and by interpolating time at equal time intervals according to the time interval of the movement pulse, it is possible to detect a precise car position that can be used for speed control in the low-speed region near landing. It is an object of the present invention to provide an elevator position detection device as described above.

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In the figure, 1 is the elevator car, 2 is the counterweight, 3 is the main rope connecting the car 1 and the counterweight 2, and 4 is the drive network of the hoist installed in the machine room and around which the main rope 3 is wound. The wheel 5 is a disc driven by a mesh wheel 4 via a timing belt 6 and has pores arranged at equal intervals around its circumference, and 7 has a pulse detector 7A for detecting the pores in the disc 5. A movement amount pulse signal 7a is generated every time the table 1 moves a predetermined distance, for example 10 mm, and in the case of an upward movement, "H",
In the case of downward movement, the direction signal 7b becomes "L"
8 is a constant frequency f _s
9 is a counter configured by series connection of a decimal counter 9A and a 4-bit binary counter 9B, and 10 is a binary output Q ₁ of the counter 9B. _Q4 is connected to data inputs _D1 to _D4 and is a 4-bit memory that stores when input T becomes "H".
The counters 9A, 9B and the memory 10 constitute a pulse interval detector 11. 12 is a subtraction counter 1 with 4-bit preset count inputs _D1 to _D4 .
2A _frequency modulator _, which uses the input value
3 is composed of a NOT gate 13A, a resistor 13B, a capacitor 13C, and an AND gate 13D, and converts the rising portion (“H” portion) of the movement pulse 7a into a pulse 13a having a pulse width sufficiently narrower than that of the sampling pulse 8a. The pulse width converter 14 is a reversible counter that adds the pulse of the input C when the input U/D is "H" and subtracts it when the input U/D is "L" to generate a signal 14a which is the higher digit of the car position signal. 15 is a reversible counter which also generates a lower digit signal 15a. Note that the output of the reversible counter 15 is reset to zero when the input R becomes "H" when the input U/D is "H", and when the input R becomes "H" when the input U/D is "L". The output is reset to 9.

Next, the operation of this embodiment will be explained.

When the car 1 moves, the rotation of the mesh sheave 4 is transmitted to the disc 5 via the timing belt 6, and when the car 1 is moving upward, the direction signal 7b becomes "H", and the rotation is transmitted every 10 mm when the car 1 moves. A movement pulse signal 7a is generated. The reversible counter 14 adds and counts this, and the signal 14a corresponding to the higher car position increases. Further, when the car 1 is moving downward, the direction signal 7b becomes "L", so the reversible counter 14 subtracts this and the signal 14a corresponding to the higher car position decreases. Through these operations, a relative car position signal in units of 10 mm is obtained from the reversible counter 14.

The decimal counter 9A counts the sampling pulses 8a, and when the number reaches 10, it generates one pulse from the output _Q4 , and the binary counter 9B generates a binary output _Q1 to Q corresponding to the number of input pulses. Generates ₄ . on the other hand,
As shown in FIG. 3, when the movement amount pulse signal 7a becomes "H", the output 13 of the NOT gate 13A
Aa becomes "L", but since capacitor 13C gradually discharges, its output is "H",
The output 13a of the AND gate 13D becomes a pulse.
When the movement amount pulse signal 7a becomes “L”, NOT
The gate output 13Aa becomes "H", but since the capacitor output 13Ca has not yet become "H", the pulse 13a is not generated. The width of the pulse 13a can be made sufficiently narrower than the pulse width of the sampling pulse 8a by selecting appropriate values for the capacitor 13C and the resistor 13B. In this way, each time the movement amount pulse signal 7a becomes "H", the pulse width converter 13 generates one pulse 13a, and the contents of the counters 9A and 9B are reset to zero. Therefore, counter 9B
The maximum value of the output Q ₁ to _{Q 4} is the travel pulse signal 7
represents the pulse time interval of a. When the movement amount pulse signal 7a becomes "H", the memory 10 receives the input _D1.
~ D ₄ is retained in memory. When the input L of the subtraction counter 12A becomes "H", the inputs _D1 to _D4 are set,
When a number of pulses corresponding to inputs D ₁ to _{D 4} come to input CD, a pulse is generated from borrow output BR. Therefore, between the pulses of the movement amount pulse signal 7a,
1/10 of the sampling pulse 8a is counted by the counter 9B, and the value is stored in the memory 10, and this value becomes the preset data of the subtraction counter 12A, so that during the next movement amount pulse signal 7a, Ten pulse signals will be output from the borrow output BR. This always holds true if the pulse width of the movement amount pulse signal 7a is constant, and is not affected by the magnitude of the pulse width. Therefore, the movement amount pulse signal 7a
As long as the pulse width does not change suddenly, approximately 10 output pulses of the frequency modulator 12 will be generated at regular intervals during the arrival of the movement pulse signal 7a. These pulses are counted by addition or subtraction in a reversible counter 15. If 1/10 of the minimum count value of the reversible counter 14 is set as the minimum count value of the reversible counter 15 and the counting capacity is set to 10, the output of the reversible counter 15 will be the signal 15a of the lower car position, and the output will be 1 mm below 10 mm. A unit car position signal is obtained. That is, the high-order car position signal 14a and the low-order car position signal 15a provide a highly accurate car position signal.

Here, if the frequency of the movement amount pulse signal 7a is f _c , then the input C of the reversible counter 15, that is, the frequency f of the output pulse of the frequency modulator 12 needs to be f=10 f _c . Further, if the modulation rate of the frequency modulator 12 is Y, then f = Yf _s ... For the output value X of the memory device 10, f _c = f _s /X ... From equations to equations, Y = 10 / X ... Therefore, The frequency modulator 12 generates a sampling pulse 8a with a frequency f _s for the modulation coefficient input value X.
is modulated to a frequency f=10/Xf _s and output. Now, if car 1 is moving upward, direction signal 7
Since b is "H", the reversible counter 15 is in an addition counting state, and when the movement amount pulse signal 7a is generated, the reversible counter 14 adds and counts the contents by 1, and at the same time, the pulse width converter 13 Output pulse 1 of
3a, the output 15a of the reversible counter 15 is reset to zero. Then, in order to count the output pulses of the frequency modulator 12 until the next movement amount pulse signal 7a is generated, the contents of the reversible counter 15 change from 0 to 9 at equal time intervals based on the equation. Conversely, when the car 1 moves downward, the direction signal 7b
Since is "L", the reversible counter 15 enters a subtraction counting state, and when the movement pulse signal 7a is generated, the reversible counter 14 subtracts the contents by 1 and at the same time, the pulse width converter 13 Output pulse 13
By a, the output of the reversible counter 15 is reset to 9, and the output pulse of the frequency modulator 12 is subtracted and counted until the next movement amount pulse signal 7a is generated, and the output is changed from 9 to 0 in equal time. Varies at intervals.

Here, the rate of change in the pulse period of the movement amount pulse signal 7a when the movement speed of the car 1 changes is examined.

Now, if the moving speed of car 1 is v [m/s], the speed change rate is a [m/s ² ], and the distance equivalent value of the unit pulse of the movement amount pulse signal 7a is △S [m], then the speed v
The period Δt [s] of the movement amount pulse signal 7a at
is, △t=△S/v The period △t' of the next movement amount pulse signal 7a is, △t'=△S/v-△t・a=△S/v-△S・a/v
It can be approximated by = △S・v/v ² −△S・a, so the period change rate α is α=1−△t/△t′=1−△S/v・v ² −△S・a /
ΔS·v=ΔS·a/v ² , and the larger the unit pulse distance equivalent value ΔS, the larger the speed change rate, and the smaller the speed, the larger the period change rate.

By the way, in the elevator speed pattern,
When the above rate of change α is the largest, it is the point where the velocity is low and the acceleration is maximum, and v = 0.5 [m/
s], a = 1.0 [m/s ² ], and △S = 10 [mm], then α = 0.01 x 1.0/0.5 ² = 0.04, and as in this embodiment, the movement pulse signal 7a is When dividing, the error is so small that it does not pose a problem.

In addition, in order to detect the amount of pulse width change of the movement amount pulse signal 7a with higher accuracy, a binary counter 9 is used.
All you have to do is increase the counting capacity of B. In this case, the counting capacity of the memory device 10 and the subtraction counter 12A will also be increased.

As explained above, in this invention, the time interval of the movement pulse of the elevator car is detected, the frequency of the pulse of a predetermined frequency is modulated using this as a modulation coefficient, and the pulse of this modulated frequency is counted to position the car. Since the signal is a lower digit signal, it is possible to interpolate time between the pulses of the travel pulse signal at equal time intervals at the same rate, without installing special equipment in the hoistway, etc. Accurate car position detection can be improved by more than one order of magnitude in nearby low-speed areas.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram showing an embodiment of an elevator position detection device according to the present invention, FIG. 2 is a detailed block circuit diagram of the portion shown in FIG. 1, and FIG. 3 is a pulse width converter shown in FIG. 2. FIG. 3 is an output waveform diagram of each part of 1...Elevator car, 7...Movement pulse generator, 8...Sampling pulse generator, 9...
... Counter, 10 ... Memory device, 11 ... Pulse interval detector, 12 ... Frequency modulator, 14 ... Reversible counter (first counter), 15 ... Reversible counter (second counter) Note that the same reference numerals in the figures indicate the same parts.

Claims (1)

[Claims] 1. A travel pulse generator that generates a pulse according to the travel distance of the car; a first counter that counts the travel pulses and generates a signal of the upper digit of the car position signal; a pulse interval detector that detects the time interval of the pulse; a frequency modulator that modulates the frequency of the pulse at a predetermined frequency using the output of the pulse interval detector as a modulation coefficient; An elevator position detection device comprising a second counter that counts each arrival of the car position signal and generates a lower digit signal of the car position signal.