FI89784B - Process and device for sending lift call signal - Google Patents

Description

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METHOD AND EQUIPMENT FOR TRANSMITTING THE ELEVATOR CALL SIGNAL

The invention relates to a method according to the preamble of claim 1 for transmitting an elevator call signal generated by a hair change in the elevator call button circuit and to an apparatus according to the preamble of claim 5 for carrying out the purpose of the method.

In those elevator call button solutions that aim for very little or no clearance to register the call, solutions are often applied in which pressing or touching the button 10 causes a change in the oscillation frequency of the circuit. The change in oscillation frequency is based on a change in capacitance, inductance, or other quantity associated with the coupling. Such call buttons are, for example, the quite commonly used capacitance-sensitive touch buttons.

15 In a conventional touch capacitance sensing button, the capacitance of the touch button is connected to the oscillation circuit so that the frequency of the oscillation circuit depends on the current value of each capacitance. When the touch button is pressed, i.e. an increase in capacitance equal to the finger capacitance is brought to the touch button, the frequency changes accordingly. The deviation of the frequency of the oscillation circuit from its value is indicated and the pressing of the button is recorded.

Although the change in frequency of the oscillation circuit as a phenomenon is easily detectable and distinctive for pushbutton purposes, there are many practical problems in its application. For example, the frequency detection circuit must be tuned to the correct detection value and sensitivity according to the resting frequency of the oscillation circuit. This has to be done individually, because the components of the oscillation circuit and the detection circuit are not completely matched to each other and for cost reasons it does not make sense to require a very narrow tolerance for the component functions. The tuning may need to be repeated because the operating values of the components may change due to aging or some other reason, changing the tuning of the expression or the characteristics of the oscillation circuit. A conventional touch button is also sensitive to environmental influences. In difficult environments where the buttons are easily soiled or where, for example, thermal .- 'f /

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the space varies greatly, it would be advantageous to use a button that engages its frame without gaps. A capacitive button would be well suited for its slit, but its other sensitivity to conditions reduces usability. The Capacit-5 button is also sensitive to certain types of vandalism. For example, gluing chewing gum to a button causes a change in the capacitance of the button, which appears as being left on the button and a continuous elevator call.

In order to avoid the above-mentioned problems, the invention provides a method and apparatus for transmitting an elevator call signal generated by a frequency change of an elevator call button circuit.

The method according to the invention is characterized by what is set forth in the characterizing part of claim 1 and the apparatus according to the invention is characterized by what is set forth in the characterizing part of claim 5.

Other embodiments of the invention are characterized by what is stated in the other claims.

The invention achieves e.g. the following advantages: The invention is applicable to many different button solutions, in which pressing the button causes a change in the frequency of the oscillation circuit.

- The solution according to the invention is constantly tuned, which improves reliability and reduces the need for maintenance.

- Continuous tuning allows, for example, more precise adjustment of the call sensitivity, because, for example, daily changes in temperature or humidity that affect the performance of the circuit components do not need to be taken into account to a significant extent. Due to the excitability, the oscillation circuit and / or the frequency detection do not have to be compensated separately, for example in case of temperature changes.

- Since the implementation of the invention is digital, it must be at least to some extent programmable. Programming can affect, for example, interference tolerance, sensitivity or self-adjustment time, i.e. the time during which the effect of the external change factor on the excitation is eliminated.

- The connection according to the invention can technically be implemented as a single microcircuit. In this case, it is advantageous to place the switching electronics of several buttons on the same circuit.

The invention will now be described in detail by means of an embodiment with reference to the drawings, in which Figure 1 shows a block diagram of an apparatus according to the invention and Figure 2 shows a circuit according to the invention.

Figure 1 is a block diagram of the connection of a capacitive touch pin to a control system. The capacitance C of the touch button is connected to an oscillator circuit 5, whose oscillation pulses are monitored by a counter 1. The operation of the counter 1 is cycled by another oscillator 6. the frequency of the oscillation circuit and thus also the number of pulses obtained. The countdown 2 thus stores the previous value of the counter 20 1, which is now compared with the new value of the counter 1 in the comparator 3. The output of the comparator depends on whether the value given by the counter 1 is greater, equal or smaller than the value obtained from the counter 2. When the counter values are the same, no further action is taken. When the number of pulses of the counter 1 is less than the number of pulses of the counter 2, the elevator call detection is performed by the detection unit 22 and the value of the down counter 2 is updated by means of the integration counter 18. The elevator call is sent to the elevator control system 4. When the number of pulses of the counter 1 is greater than the number of pulses of the counter two, the value 30 of the down counter 2 is updated via the recovery counter 19. With the exception of the oscillator circuit 1, the functions can be easily implemented programmatically in a microprocessor or as a digital circuit, or so that some of the functions are implemented programmatically and some as a circuit. To start the system, the equipment 4 ”'/ J> / O' t also includes an initial reset member 45 connected to the recovery and integration counters.

Fig. 2 shows a circuit implementation according to the solution shown in Fig. 1, in which the same reference numerals as in Fig. 1 are used where applicable. In the implementation, the transmission of a call to the control system is shown as an LED function, but may be any solution suitable for an elevator control system. it is not appropriate to explain in more detail in this context.

10 The circuit includes two oscillators 5 and 6 implemented with IC circuits, resistors and capacitors. Oscillator 5 is part of the basic oscillator that senses touch. As you touch, the capacitance of capacitor C increases and the frequency of the oscillator decreases. This oscillator-15 tors pulses binary counter 1. Instead of capacitance, the variable can be inductance, resistance, or other quantity.

The second oscillator 6 is a slow, constant frequency oscillator which generates constant length counting cycles for the pulses of the oscillator 5. Oscillator 6 resets a binary counter 1 (e.g. National 4040) which is clocked by oscillator 5.

A counter 2 consisting of IC circuits 7, 8 and 9 (e.g.

National 4516), counts down towards the binary counter 1 reading if its value deviates from it. Comparison circuit 3, which consists of circuits 10, 11 and 12 of IC -... 25 (e.g. National 4585) compares the difference between binary counter 1 and counter 2 at the end of the period of binary counter 1, i. at the time determined by the oscillator circuit 6.

The output 13 of the IC circuit 12 of the comparator 3 is connected via the AND circuit 14 and the OR circuit 15 to an integration counter 18 (e.g. National .30 4040) which, via the selected output, clocks the countdown timer 2.

The recovery counter is implemented in IC circuit 19 (e.g., National 4040), which receives pulses as the capacitance on the button decreases (finger is pulled out). When the circuit has obtained a hysteresis selection l, - I · ·. r · 5 ''

X1 of the selected number of pulses, its selected output in xi rises, causing the next STROBE pulse 20 to cause a LOAD pulse 21, which in turn loads the current value of the binary counter 1 into the countdown 2 and thus the switching returns to the basic state 5.

The detecting member 22 includes an IC circuit 46. When the touch button is pressed, the above-mentioned flip-flop is set, controlling the LED to light up.

When the electricity is switched on, the connection must return to its basic state. In this case, during the initial delay set by the resistor 23 and the capacitor 24, the value of the binary counter 1 is charged directly to the value of the down counter 2.

In the normal state, the reading of the binary counter 1 and the down counter 2 is the same and the outputs, pins 13 and 25 of the comparator 3, i.e. the IC circuit 12, are low. Likewise, the output of pin 22 from pin 26 is down 15, so that LED 30 is off.

When the touch button is pressed, the capacitance of the input 28 of the IC circuit 27 of the oscillator circuit 1 increases, thus decreasing the frequency of the oscillator 5. Since the frequency of the oscillator 6 is constant, the oscillator 5 does not have time to pulse the binary counter 1 as high as 20 the last time. The countdown 2 has a previous higher value in the memory, whereby the comparison circuit 12 notices the value of the binary counter 1 smaller than the value of the countdown 2. In this case, pin 13 of the reference circuit 12 rises. This in turn causes the simultaneously arriving STROBE pulse 20 25 to pass through the AND gate 14 and further through the OR gate 15. It in turn causes the pulse to propagate into the clock pulse of the circuit 18, thereby stepping up. After the second clock pulse, the output 28 of the circuit 18 rises, causing a clock pulse on the detection circuit 22, whereupon its output from the pin 26 rises 30, illuminating the LED 30.

During normal pressing, there are a few COUNT pulses 31, during which the countdown 2 counts down.

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When the finger is pulled out, the capacitance of the pin 28 of the IC circuit 27 decreases, whereby the frequency of the oscillator 5 increases. It, in turn, follows that during the next period of the oscillator 6, the oscillator 5 has time to pulse the binary counter 1 5 further than the previous time. Since the counter 2 was allowed to count down during pressing, its value is now smaller than the binary counter 1. Then the pin 25 of the IC circuit 12 of the reference circuit 3 rises, whereby the STROBE pulse 20 reaches the pin 33 of the AND circuit 32 and further the pin 35 of the OR circuit 34. via 10 to reset the integration counter 18 and to clock the reset counter 19. At the same time, the above-mentioned pulse also resets the detection circuit 22, whereby the LED indicator light 30 goes out.

When the reset counter 19 has received the selected number of pulses with X1, pin 37 of the AND circuit 36 rises and at the same time pin 38, 15 generating a LOAD pulse 21 for the counter counter 2. Thus, the value of the binary counter 1 is loaded into the counter counter 2 and thus returned to the basic state. The importance of X1 hysteresis is to prevent momentary disturbances from entering the system. Thus, Xl actually selects the degree of filtration.

20 If the change in the frequency of the oscillator 5 caused by the increase in capacitance remains permanent (e.g. due to chewing gum or some other reason), the connection works as follows.

As previously shown in connection with normal pressing, as a result of the capacitance change, COUNT pulses 31 25 start to come down to the counter 2. If the capacitance change is continuous, the countdown 2 slowly decreases towards the value of the binary counter 1 and in time reaches its value.

During the calculation, the detection circuit 22 is activated and the LED 30 is lit.

When equilibrium is reached, pin 13 of the reference circuit 12 drops to zero. When the pin 25 in turn rises, the detection circuit 22 is reset and the LED 30 turns off.

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When the capacitance decreases (e.g. the chewing gum is removed or it decreases for some other external reason), the value of the binary counter 1 is loaded into the value of the down counter 2 using the LOAD pulse 21 as previously described.

5 Self-tuning is active at all times and therefore the connection is always on.

It will be apparent to those skilled in the art that the invention is not limited to the examples described above but may vary to the extent set forth in the claims.

For example, the following variations or combinations thereof are included in the inventive idea set forth in the claims:

In the examples, the frequency-changing quantity of the oscillation circuit is a capacitance, the change of which is caused by an external 15 additional capacitance. Instead of capacitance, some other quantity affecting the frequency of the oscillation circuit can just as well be disturbed. A sufficiently large momentary change in the monitored frequency is essential for the success of the button function. Such are, for example, buttons in which pressing 20 causes a change in the resistance value, or buttons in which the characteristic frequency of the crystal in the oscillation circuit depends on the external force applied to the crystal.

- Instead of counters, the frequency can also be monitored directly by a converter which converts the instantaneous frequency into a digital form which can be fed to a microprocessor in which the necessary functions are performed programmatically. The microprocessor may be part of an elevator control system or it may be connected to the elevator control, for example via a serial bus.

Claims (8)

8. '· R · r ή A method for transmitting an elevator paging signal generated by a frequency change of an elevator paging circuit, the method comparing the frequency of the paging circuit to a reference value and transmitting the elevator paging signal in response to this comparison, characterized by per reference value per value generated from at least one frequency of the call button circuit prevailing at an earlier time. A method according to claim 1, characterized in that the 15th frequency is monitored as the number of pulses counted over set calculation periods and compared to the currently valid reference value, - changed to a reference value based on at least one previous result from the calculation period, and - if the number of counted pulses in a given period, including at least one counting period, deviates from the valid reference value more often than the preset, then a call signal is sent to the elevator control system (4). Method according to Claim 2, characterized in that the reference value is changed towards the value according to the previous calculation period. Method according to one of the preceding claims, characterized in that the speed at which the reference value is changed is adjustable. Apparatus for transmitting an elevator paging signal generated by a frequency change of an elevator call button circuit, the apparatus comprising at least one unit (3) for comparing the frequency of the call button circuit 9 r '' * ^ 4! In order to have a reference value in force at the time, it is known that the apparatus comprises a unit (2) for generating a new reference value on the basis of at least one frequency prevailing at an earlier time. Apparatus according to claim 5, characterized in that the apparatus comprises - in connection with the call button circuit, an oscillator (5), - a counter (1) which counts the number of pulses emitted by the oscillator (5) in set length calculation periods; to compare the number with the reference value and the unit (2) to change the reference value. Apparatus according to claim 5 or 6, characterized in that the apparatus has a second oscillator (6) 15 for setting the length of the calculation periods. Apparatus according to claim 7, characterized in that the apparatus has a capacitive touch button connected to an oscillator circuit (5), the output of which is connected to a counter (1) 20 which is periodically reset by a second oscillator (6) and that the output of the counter (1) is connected to a countdown counter (2) in which the reference value is stored and that the outputs of the countdown counter (2) and the counter (1) are connected to the comparator (3). 10 ''