JPH01212998A - Radio control system - Google Patents

Abstract

PURPOSE:To effectively eliminate an interference by the third party by providing a means for extracting first digital information and second digital information, a means for storing said second digital information for every receiving and a means for comparing the latest second digital information with the second digital information received therebefore. CONSTITUTION:A signal received by a receiver 12 in a receiving part 23 is decoded by a code decoding circuit 13 and outputted as a decoded result x23. In a numeric value information reading circuit 14, the second digital information included in the decoded result x23 is extracted, read as numeric value information representing the number of times of transmissions and stored to a first memory 15. At this time, the numeric value information stored in the first memory 15 until then is transferred to a second memory 16. A comparison part 17 compares the numeric value information of the first memory 15 with the numeric value information of the second memory 16 and when the numeric value information of the first memory 15 is larger, this signal is considered to be a newly received signal. Then, the comparison part 17 outputs the output x17 of a logical value '1'.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a wireless control system for wirelessly controlling the operation of equipment at a remote location, and in particular a wireless control system that takes measures against interference by third parties, etc. Regarding.

91 [Prior Art] This type of wireless control system is generally a system in which a transmission signal is encrypted and then transmitted. however.

Until now, only control signals for controlling the partner station and identification signals for selecting the partner station were encrypted.

An example of a conventional wireless control system will be explained with reference to FIG.

In FIG. 3, a control signal is sent from the control station, and control is performed on one of the controlled stations A to C. Let station X be a wireless station operated by a third party.

The control station uses the identification signal setting unit 23 to set the identification signal of the controlled station, turns on the switch 22, and transmits the control signal with the identification signal added to the control signal by the control signal transmitter 24.

25, 26, and 27 are control signal receiving devices.

28.29.30 are electronic devices to be controlled.

The control signal receiving device responds only to the controlled station corresponding to the identification signal set by the control station, and the electronic equipment is controlled.

When the control station transmits a control signal in which the identification signal of the controlled station A is set, the electronic device 28 is activated. When this is finished, the electronic device 29 of controlled station B is started,
Furthermore, the electronic device 30 of the controlled station C is activated. Here, among the signals sent from the control station to the controlled station, the control signal and the identification signal are encrypted. In this case, the X station cannot easily know what kind of codes the control signal and identification signal are composed of.

[Problem to be solved by the invention]

However, if the X station receives the encrypted information transmitted from the control signal transmitter 24 and stores it in the memory 32, and retransmits this stored information after a certain period of time has elapsed,
The electronic device of the controlled station corresponding to the identification signal stored in the memory 32 responds.

In this way, the X station, which is a third party, can activate the electronic device without having to decrypt the code.

This becomes a big problem when the electronic device controls something of high social importance, such as the supply of electric power.

In view of these problems, one technical object of the present invention is to provide a wireless control system that can reliably eliminate interference by third parties.

[Failure to solve the problem]

In the wireless control system according to the present invention, the control station includes a first digital information generating means and a second digital information generating means that differs for each transmission, and the control station generates the first digital information and the second digital information. After combining, the first digital information and the second digital information are transmitted by a transmitting means, and the controlled station receives the first digital information and the second digital information from the receiving means for receiving the signal transmitted from the control station and the output of the receiving means. a means for extracting, a means for storing the extracted second digital information each time it is received, and a means for comparing the latest second digital information with the second digital information received earlier, It is characterized in that it is determined whether or not to perform control based on the latest first digital information in accordance with the comparison result of the comparison means.

The present invention also includes: As the second digital information.

Numerical information representing the number of transmissions is transmitted, and the controlled station compares the latest second digital information with the previously received second digital information, and uses the latest second digital information. The present invention is characterized in that control is performed using the latest first digital information only when the indicated number of transmissions is greater than the number of transmissions indicated by the previously received second digital information.

〔Example〕

Next, two embodiments of the present invention will be described.

FIG. 1 and FIG. 2 are block diagrams of a control station and a controlled station, respectively, which are applied to the present invention.

Referring to FIG. 1, the control station has a switch 1 and an identification signal setting section 2 as first digital information generating means, and also has a control signal transmitting device 3.

The control signal transmitting device 3 includes a second digital information generating section 4 consisting of a counter 10 and a parallel-to-serial conversion circuit 11, and a first .
It has a transmitting section 7 consisting of second combining circuits 5, 6, an encryption circuit 8, and a transmitter 9.

In FIG. 1, when switch 1 is turned on.

The control signal transmitting device 3 generates a signal that is a combination of the control signal representing activation by the switch 1 and the identification signal output from the identification signal setting section 2 .

The operation of the control signal transmitting device 3 will be explained as follows. The first synthesis circuit 5 synthesizes the output from the switch 1 (=control signal representing activation) and the output from the identification signal setting section 2 to obtain first digital information. The output of the switch 1 is also input to the second digital information generator 4.

Here, using the counter 10, information 1 that is different for each transmission is
o is obtained, and further parallel information Z is obtained by the parallel-serial conversion circuit 11.
16 into serial information and outputs this as second digital information. As the counter 10, its output ZIG
If you use something with about 20 bits.

220 = 1,048,576, and different information can be output for each transmission up to a million or more transmissions.

This is 2. For example, assuming that wireless control is performed on average about 100 times a day, 2" / 100 (Sunday) Yu 10.485 (
El)=28.7 years, which is practically equivalent to outputting different information every time it is transmitted for an infinitely long time. The radio equipment that actually constitutes the system is generally considered to have a lifespan of around 10 years, and there is no practical problem as long as it continues to output different information each time it is transmitted for a longer period of time.

The second synthesis circuit 6 synthesizes the first digital information and the second digital information and sends it to the transmitter 7. In the transmitter 7, the output of the second combining circuit 6 is encrypted by the encryption circuit 8, and transmitted by the transmitter 9. The encryption circuit 8 may be a well-known one.

The signal transmitted in this way has the following characteristics.

(1) In addition to the first digital information consisting of a control signal and an identification signal, second digital information that differs for each transmission is included.

(11) Not only the first digital information but also the second digital information is encrypted.

Next, how to receive and process this signal in the controlled station shown in FIG. 2 will be explained. The controlled station is.

It has a control signal receiving device 21 and an electronic device 22 to be controlled.

The control signal receiving device 21 includes a receiver 12 and a decryption circuit 1.
3, and an identification signal detection section 18 as a first digital information extraction means.

It also includes a numerical information reading section 14 as a second digital information extraction means.

The control signal receiving device 21 operates as follows.

In the receiving section 23, the signal received by the receiver 12 is decrypted by a decryption circuit 13 having a function opposite to that of the encryption circuit 8 described in FIG. 1, and output as a decryption result Z23. The numerical information reading unit 14 extracts the second digital information included in the decoding result Z23, reads this as numerical information representing the number of transmissions, and stores it in the first memory 15. At this time, the numerical information previously stored in the first memory 15 is transferred to the second memo I716.

The comparison unit 17 compares the numerical information in the first memory 15 and the numerical information in the second memory 16, and if the numerical information in the first memory 15 is larger, this signal is regarded as a newly received signal. . Then, the comparator 17 outputs an output Z17 with a logical value of "1#".

On the other hand, the identification signal detection section 18 determines whether or not the identification signal of the output Z23 of the receiving section 23 is assigned to this controlled station. If the signal corresponds to this controlled station, the identification signal detection unit 18 outputs an output zts with a logical value of "1".

Furthermore, the startup information reading section 19 monitors the control signal included in the output x23, and when it detects that the switch 1 on the control station side is turned on, it outputs the output Zli with a logical value of "1".
Output l.

As a result of the above operation, the conditions for the output 220 of the AND circuit 20 to take the logical value "'1" are as follows.

(1) Regarding the second digital information, the newly received latest numerical information (the contents of the first memory 15) has a larger value than the previously received numerical information (the contents of the second memory 16). It is.

(2) The identification signal for this controlled station is correctly received.

(3) The control signal is likely to be received correctly.

Note that in order for the first conditions (2) and (3) to hold true, the second-order condition is also required.

(4) The decryption is performed correctly in the decryption circuit 13.

(If the decryption is not performed correctly, the identification signal and control signal for this controlled station will not be received correctly.) Only when all of the above conditions (1) to (4) are met.

The output Zoo of the AND circuit 20 has a logical value of "1".

Startup control is applied to the electronic device 22.

Here, in order to apply the present invention to the wireless control system shown in FIG. 3, condition (1) is required. Therefore, in the third party's In other words, in this case, the condition ( 1)
is not satisfied, and startup control cannot be applied to electronic devices. In other words, in order for the X station to start up the electronic equipment of the controlled station, it is necessary to decrypt the code, check the signal structure, etc., and then re-encrypt it based on this.

Usually for digital signals.

An infinite number of combinations of encryption keys can be considered (for example, 1
A combination of 0 and 2 is easily realized. ) Since it is not easy to decipher encrypted digital signals, it is practically impossible for the X station to control the electronic equipment of the controlled station.

〔Effect of the invention〕

As explained above, by using the wireless control system of the present invention, it is possible to reliably prevent a third party from activating the electronic equipment of the controlled station from the wireless station, and It is possible to only control the station.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a control station used in the present invention. FIG. 2 is a configuration diagram of a controlled station used in the present invention. FIG. 3 is a configuration diagram for explaining the wireless control method. 1 is a switch, and 4 is a second digital information generator. 7 is the transmitting section. Station X Controlled station A Controlled station B Controlled station C

Claims (1)

[Claims] 1. The control station includes a first digital information generating means and a second digital information generating means that differs for each transmission,
The first digital information and the second digital information are combined and then transmitted by a transmitting means, and in the controlled station, a receiving means receives the signal transmitted from the control station, and from the output of the receiving means. means for extracting the first digital information and second digital information; means for storing the extracted second digital information each time it is received; and the latest second digital information and the previously received second digital information. 1. A wireless control method, comprising: means for comparing the first digital information with the second digital information, and determining whether or not to perform control based on the latest first digital information according to the comparison result of the comparing means. 2. Numerical information representing the number of transmissions is transmitted as the second digital information, and the controlled station compares the latest second digital information with the second digital information received before this. , only when the number of transmissions represented by the latest second digital information is greater than the number of transmissions represented by the second digital information received before this, the latest first
2. The wireless control system according to claim 1, wherein control is performed using digital information. 3. The wireless control system according to claim 1, wherein the transmitting means has an encrypting means, and the receiving means has a decrypting means.