JP2009078904A - Communication system for elevator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication system for an elevator capable of surely carrying out communication even when a communication system is interfered by a power line. <P>SOLUTION: In the communication system for the elevator, a switching cycle of power converters 8 and 20 and a transmission speed and a bit number of error-correcting codes in a communication transmission passage are set so that noise on the power line caused by switching in the power converters 8 and 20 has an error bit correcting function of equal to or more than the bit number having the possibility to rewrite bit information in one communication frame. Therefore, the error bit correcting function capable of suitably coping with the noise generated by the power converters 8 and 20 can be achieved, and communication can be surely carried out even when the communication system is interfered by the power line. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an elevator communication system.

  In the conventional elevator system, the tail code between the control panel for controlling each elevator and the push button in the car and the car position indicator, the push button and the car position installed in the control board and each floor hall Push button information, car position, and planned stoppage between the display unit and the group management control panel for optimal operation control of multiple elevators and the control panel for each of multiple elevators controlled by group management A communication transmission network for exchanging information related to driving such as floors and driving directions is spread out as disclosed in Patent Document 1.

  On the other hand, in order to operate the entire elevator system, the control panel and the car door are opened and closed between the commercial power supply and the elevator control panel, between the power converter in the control panel and the drive motor that drives the elevator car itself up and down. Group management of commercial power supply and multiple elevators between power converters to be driven, air conditioners mounted on the car, lighting equipment, display devices and control devices, between control panels and display devices and control devices at the landings The power line is stretched vertically and horizontally, such as between the control panel. The following countermeasures have been proposed for communication errors that occur in the communication transmission line due to these nearby power lines and external electromagnetic waves.

  Patent Document 2 discloses a system that performs communication using a plurality of carrier signals in a tail code, estimates an S / N ratio for each carrier signal, and assigns transmission data to the carrier according to the value. There are proposals for changing the amount to stabilize communication.

  Patent Document 3 describes noise generated at random timing by maintaining the operation state of the elevator in synchronization with the timing of a stable environment for communication and controlling the elevator with the retained operation signal of the elevator. Has proposed a highly accurate control method that eliminates the possibility of erroneous detection even if the input is made.

  Patent Document 4 proposes detecting the voltage of the transmission line and blocking the transmission line when the value is large to prevent malfunction due to surge and damage to the components.

  Japanese Patent Application Laid-Open No. 2004-228561 proposes that noise reduction means is provided at a receiving station on a transmission path, and that the configuration is changed with the characteristics of transmission errors to exhibit stable characteristics.

Japanese Examined Patent Publication No. 6-79960 JP 2007-1774 A JP 2006-199466 A Japanese Patent No. 3346980 JP 2007-36588 A

  However, in patent document 1, although the network application to an elevator system is proposed, there is no mention about troubles, such as a transmission failure. In Patent Document 2, since transmission data is allocated according to the S / N ratio, it is a response after an event occurs, and after a certain amount of data is accumulated, a response based on the result Therefore, there is some difficulty in real time. In Patent Document 3, the state of transmission must be monitored with high frequency. Also in Patent Document 4, it is a countermeasure after a failure occurs in the transmission path. Also in Patent Document 5, since the characteristics of the noise that is received are grasped and the characteristics of the noise removal function are determined and dealt with, there is a time delay, and there is still difficulty in real time.

  The objective of this invention is providing the communication system of the elevator which can communicate reliably, even if a communication system receives interference from a power line.

  The present invention is based on the novel knowledge regarding the relationship among the switching period of the power converter, the transmission speed in the communication transmission path, and the number of bits of the error correction code, which the present inventors have found. Based on this knowledge, more specifically, the power line noise generated by switching in the power converter has a function of correcting an error bit more than the number of bits that may rewrite bit information in one communication frame. The switching period of the converter, the transmission speed on the communication transmission line, and the number of bits of the error correction code are set.

  According to the present invention, an error bit correction function that can sufficiently cope with noise generated by the power converter can be obtained, so that communication can be reliably performed even if the communication system receives interference from the power line.

  Hereinafter, an elevator communication system according to one embodiment of the present invention is shown in FIG.

  A car 1 on which a passenger rides is connected to a counterweight 3 via a rope 2 and is suspended on a sheave 4 and a sled wheel 5. The sheave 4 is driven by a driving motor 6, and the motor 6 is supplied with pulsed driving power chopped at a predetermined switching frequency from a power converter 8 in the control panel 7. Yes. Similarly, since pulsed power is applied from the converter 20 to the door motor 21 that drives a door (not shown) of the car 1, noise is superimposed on the car feed line 19 and the hall feed line 13, which are power lines. In order to prevent this effect from being exerted on the adjacent transmission lines 17 and 22 in the cables 12 and 18, the present invention is implemented as described later.

  In the elevator system, in order to operate the car 1, the hall transmission line 17 is used around the main communication terminal 9 in the control panel 7, and the push buttons 15-1 to n and display devices 14-1 to n on each floor are used. Hall communication terminals 16-1 to 16-n for control, a car push button 15-c using the car transmission line 22, a car communication terminal 16-c for controlling the display device 14-c, and other groups A group management terminal 16-g in the management apparatus and a maintenance terminal 16-h for interfacing with an external maintenance center communicate with each other. In these terminals, the transmission speed and bit error correction function described later are set in relation to the switching frequency of the power converters 8 and 20 that are noise sources.

  Hereinafter, the car communication terminal 16-c will be described as an example of the communication terminal in the communication system with reference to FIGS.

  FIG. 2 shows the configuration of a communication terminal in an embodiment of the present invention. The car communication terminal 16-c is mainly composed of a transceiver 23 and a communication microcomputer 24, and the electric power obtained from the car feed line 19 is converted into a direct current by the AC / DC converter 11-c. Supplied to electronic equipment. Data addressed to the communication terminal 16-c transmitted from the main communication terminal 9 via the car transmission line 22 is converted by the transceiver 23 into an electrical signal that can be used by the communication microcomputer 24. The communication microcomputer 24 performs data transmission / reception, error detection / encoding processing, and serial / parallel data conversion, and the data is transferred to the display 14-c and the like. The transmission is performed in the reverse flow. The car transmission line 22 that performs this communication shares the cable 18 with the car feed line 19 that sends power to each device in the car.

  FIG. 3 shows the main functions of the communication microcomputer 24. The communication microcomputer 24 has functions of an initial setting unit 25, a data transmission / reception unit 26, an error correction function execution unit 27, and a data holding unit 28.

  The initial setting unit 25 includes a transmission rate setting unit 25-a that sets a transmission rate, a communication frame configuration bit setting unit 25-b that sets the number of bits that constitute a communication frame, which will be described later, and the number of bits that can correct a transmission error. There is an error correctable bit number setting unit 25-c to be set. These may be set by a program or may be set by hardware such as a dip switch.

  The data transmission / reception unit 26 actually exchanges data with other communication terminals according to the transmission rate set by the initial setting unit 25, the number of bits of the frame, and the number of correctable bits. This can also be configured by hardware or program.

  The error correction function execution unit 27 determines whether there is a transmission error in the received data and an encoding unit 27-a that adds an error correction code to transmit data, and if there is, performs a correction process. There is an error detection / correction unit 27-b. Here, there are a Hamming code, a BCH code, a Reed-Solomon code, etc. as an error bit correction function, and an appropriate one may be selected from them. These functions may also be realized by hardware such as a shift register, or the functions may be implemented by a program.

  The data holding unit 28 holds data to be transmitted / received and performs parallel / serial data conversion. This is realized by a memory or the like.

  The communication system has been described with reference to FIGS. 2 and 3 by taking the car communication terminal 16-c as an example. Here, the car communication terminal 16-c has been described as an example, but the same applies to other communication terminals.

  Returning to FIG. 1, the overall configuration will be further described. Near the transmission line connecting the main communication terminal 9 and the communication terminal of each elevator equipment, commercial power is supplied to the elevator equipment (14-1 to n, 15-1 to n, 16-1 to n) in each hall. A car feed line 19 connecting a power feed 10 to a hall feed line 13 for transmitting a voltage converted into a direct current by an AC / DC converter, an AC / DC converter 11-c for feeding a door motor 21 for driving a car door, and the like. Are placed close together. In particular, the hall transmission line 17 and the hall feed line 13 use the same cable 12, and the car transmission line 22 and the car feed line 19 use the same cable 18. Transmission errors are caused by the power converters connected to these feeders. As an example, the operation of the power converter 20 that supplies power to the door motor 21 that drives the car door will be described with reference to FIG.

  FIG. 4 shows a main circuit / control circuit configuration of the power converter 20 in one embodiment of the present invention. The power converter of this embodiment is a so-called pulse width modulation (PWM) power converter. Power is supplied from the commercial power supply 10 to the power converter 20 via the car feed line 19. In the power converter 20, AC / DC conversion is performed by the rectifier 29. Although a diode is shown as a semiconductor element for the rectifier 29 in FIG. 4, it is not limited to this, and a self-excited semiconductor switching element may be used. The DC voltage output from the rectifier 20 is DC / AC converted by the inverter 30 to drive the door motor 21. At this time, the control circuit 34 controls the door motor 21 to rotate according to the command value.

  Next, the operation of the control circuit 34 is shown in FIG. In order to drive the door motor 21 according to the command, the rotational speed control unit 35 compares the command value with the actual rotational speed value of the motor obtained from the rotational speed detector 32 shown in FIG. Create a current command value. In the torque current control unit 36, the generated torque current command value is compared with the actual measured torque current values obtained from the phase current sensors 33-1 to 3-n shown in FIG. To do. Next, the PWM comparison unit compares the generated voltage command value with the carrier wave set in advance by the carrier wave setting unit 37, and commands for switching at the intersection are switching elements 31-1 to 6 of the inverter 30 shown in FIG. Send to.

  Here, the carrier wave setting unit 37 sets the waveform of the carrier wave, the switching frequency or the switching period. Although the details will be described later, the setting of the switching frequency or the switching cycle defines ON / OFF of the power supply pulse and relates to the number of occurrences of noise in a predetermined time. Such carrier wave characteristics may be set by a program or by hardware. Moreover, the control used by each control part (35, 36) should just be what can make the difference of command value and measured value, such as PI control, into zero.

  The outline of the embodiment will be described below with reference to FIG. As described with reference to FIG. 5, in the three-phase inverter, when the voltage commands for the u-phase, v-phase, and w-phase are given by 40-1, 40-2, and 40-3, respectively, each voltage command and carrier wave Switching is performed at the timing of crossing with 41. Here, paying attention to the switching half-cycle section 42 of the converter, switching is performed three times in total for each phase (43-1, 43-2, 43-3). Since the inverter outputs a rectangular wave voltage by switching, a zero-phase current 44-1 is generated due to a change in the voltage. Noise 44-2 due to the zero-phase current 44-1 is superimposed on the data string 45 of serial communication. This noise causes a transmission error.

Here, the time required to transmit the communication frame 46 composed of the header 46-1, the information data 46-2, and the error correction code 46-3 designating the command and ID indicating the transmission / reception terminal as shown in FIG. (Hereinafter referred to as the communication frame time length) 47 is T _f , the number of phases of the power converter is n, and the switching half cycle section 42 is T _S / 2, the number of noises e _max superimposed in the communication frame 46 is It can be shown as:

  In this embodiment, since it is a three-phase converter, n = 3. Therefore, equation (1) is rewritten as equation (2).

  In the present embodiment, the numbers in [] are rounded up to the left of the previous expressions (1) and (2).

FIG. 8 shows the relationship between the communication frame time length _Tf and the superimposed noise. When T _{f is set} to T _S / 2 or more and T _S or less, e _max is 6. When T _f is set to T _S / 2 or less, e _max is 3. Here, when b is the total number of bits constituting the communication frame and v _C is the transmission rate, equation (3) is derived.

  However, in the present embodiment, the value in [] is rounded up.

Equation (3) shows that the number of superimposed noises can be adjusted here by changing T _s , but the same effect can be obtained even if the switching period of the power converter is changed. In order to make it less susceptible to noise, the communication system may have an error bit correction number c equal to or greater than the number of noises shown in equation (3) as in equation (4).

Hereinafter, a method for setting the total number of bits b, the number of error bit corrections c, the switching period T _S , and the transmission rate v _C constituting the communication frame in this embodiment will be described.

One form of the setting method is shown in FIG. This process may be executed once for each terminal during the initial process immediately after the elevator is started, or if it is desired to respond adaptively to the influence from others, the setting is dynamically performed multiple times. You may implement. In this embodiment, the bit correction number c of the error bit correction function of the communication system, the total number of bits b constituting the communication frame, and the switching period T _S of the power converter are fixed in advance in the equations (3) and (4). initial setting unit 25 shown as a value in FIG. 2, may be set by the carrier setting unit 37 shown in FIG. 5, sets the communication frame length T _f by setting by calculating the transmission rate v _C. That is, by adjusting the communication frame time length 47 in FIG. 6, the number of noises e _max superimposed in the communication frame is made equal to or less than the bit correction number c. In this embodiment, the calculation and setting are performed by the communication microcomputer 24 (the same applies to the forms of FIGS. 10 and 11 described later).

As an example, c is 3 bits, b is 20 bits, and 1 / T _s is 8 kHz. From formulas (3) and (4), v _C can be calculated by formula (5).

Substituting each value shows that the transmission rate v _C should be 320 kbps or higher. This value is set in the transmission rate setting unit 25-a shown in FIG.

Another form of the setting method is shown in FIG. In this embodiment, the number of bit corrections c, the transmission rate v _C and the number of bits constituting a communication frame b in Equations (3) and (4) are set in advance as fixed values in the initial setting unit 25 shown in FIG. The switching period T _S of the power converter is calculated and set. That is, by adjusting the switching half cycle section 42 in FIG. 6, the number of noises e _max superimposed in the communication frame is made equal to or less than the number of bit corrections c.

3 bits c as an example, a v _c 400kbps, b is referred to as 20 bits. From the expressions (3) and (4), T _S can be calculated by the expression (6).

  When values are assigned to the respective values, it is understood that the switching period Ts of the power converter may be set to 100 μs or more, that is, the switching frequency may be set to 10 kHz or less. This value is set in the carrier wave setting unit 37 shown in FIG.

FIG. 11 shows still another form of the setting method. In this embodiment, in the equations (3) and (4), the transmission rate v _C , the communication frame configuration bit number b, and the switching period Ts of the power converter are set to fixed values in advance, and the initial setting unit 25 shown in FIG. Is set by calculating the bit correction number c.

As an example, v _C is 400 kbps, b is 20 bits, and 1 / Ts is 8 kHz. From Equations (3) and (4), c can be calculated by Equation (7).

  If a value is substituted for each, it can be seen that the bit correction number c may be 3 bits or more. This value is set in the error correctable bit number setting unit 25-c shown in FIG.

  According to the above embodiment, since it is possible to correct a transmission error occurring within the communication frame time length, it is possible to construct a communication system that is less susceptible to the noise generated by the power converter.

1 shows an elevator communication system according to an embodiment of the present invention. The structure of the communication terminal in one Example of this invention is shown. The main function of the communication microcomputer in one Example of this invention is shown. The main circuit and control structure of the power converter in one Example of this invention are shown. The operation | movement of the control circuit of the inverter in one Example of this invention is shown. An outline of one embodiment of the present invention will be described. The structure of the communication frame in one Example of this invention is shown. The relationship between the communication frame time length and the superimposed noise is shown. One form of the method for setting the total number of bits, the number of error bit corrections, the switching period, and the transmission rate is shown. Another form of the method for setting the total number of bits, the number of error bit corrections, the switching period, and the transmission rate is shown. Another form of the method for setting the total number of bits, the number of error bit corrections, the switching period, and the transmission rate is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Passenger car 2 Rope 3 Counterweight 4 Sheave 5 Deflection car 6 Electric motor 7 Control panel 8,20 Power converter 9 Main communication terminal 10 Commercial power supply 11-1,11-c, 11-h, 11-g AC / DC Converters 12, 18 Cable 13 Hall feed lines 14-1 to n, 14-c Display devices 15-1 to n, 15-c Push buttons 16-1 to n, 16-c, 16-h, 16-g Communication Terminal 17 Hall transmission line 19 Car feed line 21 Car door drive motor 22 Car transmission line 23 Transceiver 24 Communication microcomputer 25 Initial setting unit 25-a Transmission speed setting unit 25-b Communication frame configuration bit number setting unit 25- c Error correctable bit number setting unit 26 Data transmission / reception unit 26-a Transmission unit 26-b Reception unit 27 Error correction function implementation unit 27-a Coding unit 27-b Error detection / correction unit 28 Data Sandwiching member 29 rectifier 30 inverter 31-1～6 switching element 32 rotational speed detector 33-1～3 current sensor 34 the control circuit 35 rotation speed control unit 36 a torque current controller 37 carrier setting unit 38 PWM comparator unit

Claims (5)

In an elevator communication system in which a power line for supplying power from an electric power converter to an elevator device and a communication transmission path for transmitting a signal for controlling the elevator device transmitted and received by a communication terminal are arranged close to each other,
The noise on the power line generated by switching in the power converter has an error bit correction function of more than the number of bits that may rewrite bit information in one communication frame in the signal.
The elevator communication system, wherein a switching cycle of the power converter, a transmission speed in the communication transmission path, and the number of bits of an error correction code are set.   2. The elevator according to claim 1, wherein two of the switching period, the transmission speed, and the number of bits of the error correction code are set in advance, and the other is calculated for the two. Communications system. According to claim 1 or 2, wherein the number of phases of the power converter, the switching period of the power converter, wherein the 1 number of bits of the communication frame, the transmission rate, the number of bits of each n of the error correction code, T _S, Let b, v _C and c be
An elevator communication system, wherein c ≧ n (2b / v _C T _S ).   The elevator communication system according to any one of claims 1 to 3, wherein the power converter is of a pulse width modulation type.   The elevator communication system according to any one of claims 1 to 4, wherein the error correction code is one of a Hamming code, a BCH code, and a Reed-Solomon code.

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