JPH10164677A - Receiver and method for discriminating received data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a receiver and a method for discriminating received data by which data can be received with high accuracy in an excellent noise-resistant state. SOLUTION: Whether or not the leading edge of a pulse train of received data falls within the range of the design value of a header is confirmed (S2) and, when the leading edge falls within the range, the leading edge is stored as the measured value of the header (S4). Then the numbers of '0' and '1' contained in the succeeding received data are discriminated based on the dispersion range of the design value composed of '0' and '1' and the predicted length of the received data is calculated based on the discriminated numbers of '0' and '1', the header, the design values of '0' and '1' data lengths, and the measured value of the header and the predicted length is compares with the measured length of the received data (S5-S16). When both lengths are nearly equal to each other, the received data are discriminated as the data to be received by its own receiving circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiver and a received data discriminating method, and more particularly to a receiver for transmitting a predetermined radio wave to an external device equipped with a receiver to remotely control the operation of the external device. The present invention relates to an apparatus and a method for determining received data.

[0002]

2. Description of the Related Art A so-called remote control system which realizes start / stop and operation control of an external device by remote control is used in a wide range of fields. In recent years, as an external device to be controlled, for example, an engine starter system that starts and stops an engine of a typical vehicle such as an automobile has been widely used. Such a remote control system generally includes a plurality of key switches for operation in a transmitter, and generates digital signals by processing input data by the key switches with a built-in microcomputer. The digital signal is modulated and amplified by a high frequency circuit and transmitted as a control signal for remote control from the antenna to the receiver. On the other hand, an external device to be controlled is configured to receive the control signal in a receiver provided in the own device and perform an operation according to the signal.

A receiver of such a remote control system transmits a received signal from a predetermined transmitter to the own receiver before interpreting the received control signal by the own receiver and operating. It is necessary to determine whether the signal has been transmitted or a signal or noise from a device other than a predetermined transmitter.

In particular, in a receiver of a remote control system in which a control signal at the time of transmission is represented by three types of pulse widths of "header", "0", and "1" modulated in frequency, reception is performed. Accurate discrimination of these pulses (pulse width discrimination) and noise elimination are required to improve data accuracy. To this end, measures to minimize the allowable range of each pulse width, that is, to narrow the receivable frequency range of the receiver as much as possible can be considered. In this case, in the transmitter, the oscillation clock needs to have a small variation, that is, a small deviation from an ideal value in design. However, in order to oscillate an oscillation clock with little variation, it is generally necessary to use a crystal oscillator or a ceramic oscillator for the transmitter.
There is also a problem in terms of weight reduction. Therefore, a method of reducing the cost by forming a so-called CR oscillation circuit using small capacitors and resistors is considered. However, the oscillation frequency of the CR oscillation circuit causes a very large variation as compared with the crystal or ceramic oscillation, so that a signal having such a large variation can be received by the receiver. It is necessary to widen the frequency range, and in this case, noise resistance becomes a problem.

A conventional example employed in a receiver of a remote control system using the above three types of pulse widths to satisfy cost and noise resistance will be described with reference to FIG.

FIG. 6 is a diagram for explaining a process of determining a received signal in a receiver of a remote control system as a conventional example. As shown in the figure, in the receiver, the upper limit value and the lower limit value (for example, ± 20%) of the variation (deviation) of the pulse width predicted around the design value (ideal value) are preset for the three types of pulses. Then, the range of the pulse width of the received signal is divided, for example, into three between the upper limit and the lower limit. Upon receiving a signal, the receiver first determines that the pulse width of the signal, which would correspond to a "header",
Which of the above-mentioned variation ranges is included in or outside the variation range is determined from the time of the “header” pulse stored in advance. If the pulse of the signal is out of the variation range, it is determined that the signal is not a signal addressed to the own receiver, and the pulse is ignored. On the other hand, if the pulse width of the signal falls within any of the above ranges, it is interpreted that the pulse is a "header" and that a pulse data sequence following the pulse is a signal to be received. . Then, the pulse train following the first pulse is assumed to be data of “0” or “1” having the same variation, and the variation range to which the first pulse belongs and “0” and “1” stored in advance. The reception process is performed by determining whether it is "0", "1", or any other based on the "pulse time".

[0007]

However, in the above conventional example, if the number of divisions in the range of variation is small, favorable noise resistance cannot be obtained. Conversely, if the number of divisions is too large, the load of the discrimination processing increases, and the processing time increases. Further, when the received signal is near the boundary of the range of variation, there is a problem that the receiving performance becomes unstable.

Accordingly, an object of the present invention is to provide a receiving apparatus which is excellent in noise resistance and capable of receiving data with high accuracy, and a method of determining received data.

[0009]

To achieve the above object, a receiving apparatus according to the present invention has the following configuration.

That is, in a receiving apparatus for receiving a signal group from the outside, a time length of a head signal in the signal group is measured, it is determined whether or not the signal falls within a predetermined error range. A first signal discriminating means for discriminating the first signal to be received, and a succeeding signal subsequent to the first signal based on a pre-stored reference value when the first signal discriminating means determines that the signal is the first signal to be received. And a subsequent signal discriminating means for discriminating.

Preferably, when the subsequent signals include 0 information and 1 information having different time lengths, the reference values are different reference values for the 0 information and the 1 information, respectively. The determining means may determine whether or not the subsequent signal falls within the predetermined error range based on the reference value of the 0 information and the reference value of the 1 information. Thus, it is determined whether each of the signal groups falls within a predetermined error range.

Further, the 0 which is determined by the subsequent signal determining means is 0.
Counting means for counting the number of pieces of information and one piece of information,
After the subsequent signal discriminating means has discriminated the predetermined number of the subsequent signals, the number of 0 information and 1 information counted by the counting means, the reference value of the 0 information and the reference value of the 1 information, and the A subsequent signal length calculation unit that calculates a time length of the subsequent signal based on the measured value and a pre-stored reference value; a signal length measurement unit that measures an actual time length of the subsequent signal; Means for comparing the time length of the subsequent signal calculated by the means with the actual time length of the subsequent signal measured by the signal length measuring means, and the signal group based on a comparison result of the comparing means. Is determined to be a signal group to be received. Thereby, noise resistance and reception accuracy are improved.

[0013] Preferably, the apparatus further comprises a number-of-subsequent-signals determining means for determining whether a predetermined number of signals are included in the subsequent signals. Thereby, it is determined whether or not the signal group is to be received by the receiver based on the number of signals included in the received signal group.

[0014] In order to achieve the above object, a received data discriminating method according to the present invention has the following configuration.

That is, this is a received data discriminating method for receiving a signal group from the outside, which measures the time length of the first signal in the signal group, determines whether the signal falls within a predetermined error range, and enters the error range. In this case, it is determined to be the first signal to be received,
When it is determined that the received signal is a head signal to be received, a subsequent signal following the head signal is determined based on a reference value.

Preferably, when the subsequent signals include 0 information and 1 information having different time lengths, the reference values are different reference values for the 0 information and the 1 information, respectively. It is preferable to determine whether the subsequent signal falls within the predetermined error range, based on the reference value of the first information and the reference value of the one information. Thus, it is determined whether each of the signal groups falls within a predetermined error range.

Further, 0 included in the determined subsequent signal is included.
After counting the number of the information and the number of the 1 information, and determining a predetermined number of the subsequent signals, the number of the counted 0 information and 1 information, the reference value of the 0 information and the reference value of the 1 information,
And, based on the measurement value and the reference value of the head signal, calculate the time length of the subsequent signal, measure the actual time length of the subsequent signal, the time length of the subsequent signal and the actual time of the subsequent signal And comparing the signal group with a signal group to be received based on the comparison result. Thereby, noise resistance and reception accuracy are improved.

Further, preferably, it is determined whether or not a predetermined number of signals are included in the subsequent signal,
It is characterized in that it is determined whether the signal group is a signal group to be received. Thereby, it is determined whether or not the signal group is to be received by the receiver based on the number of signals included in the received signal group.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a receiving apparatus according to the present invention will be described.
An embodiment applied to an engine starter system for starting and stopping an engine of a typical automobile will be described with reference to the drawings.

First, the operation of the entire engine starter system and the outline of the apparatus will be described with reference to FIGS.

[System Configuration] FIG. 1 is a diagram showing an engine starter system as one embodiment of the present invention.

In FIG. 1, reference numeral 100 denotes a transmitter, and 200 denotes an automobile on the receiving side. The transmitter 100 is provided with two push-down operation key switches (hereinafter, operation keys) X and Y. The operation key X is a key for starting the engine, and the operation key Y is a key for stopping the engine.

When the operation key X or Y of the transmitter 100 is depressed, the transmission circuit 101 of the transmitter 100 transmits an “engine start / stop signal” of a predetermined format to the automobile 200.
Is converted into a radio signal and transmitted to the receiving side via the antenna 102.

The vehicle 200 on the receiving side includes an antenna 201 for receiving a radio signal from the transmitter 100 and a receiving circuit 20.
2, and the engine control unit (hereinafter referred to as EC
U) 203.

Next, the transmission circuit 101 and the reception circuit 202
Will be described.

[Configuration and Operation of Transmitting Circuit 101] FIG.
FIG. 1 is a block diagram showing a transmission circuit as one embodiment of the present invention.

In the figure, a transmission circuit 101 is
In addition to the battery power source 107 for driving the
2, nonvolatile memory 103, oscillation circuit 104, CPU1
05, a reset circuit 106, and the operation keys described above.

Next, the operation of the transmitter 100 will be described. When any one of the operation keys X and Y is pressed, the reset circuit 106 sends a reset pulse to the CPU 105. When a reset pulse is input, the CPU 105 starts up and starts operation, and performs initialization. And
The CPU 105 resets the reset circuit 106
Is stopped, the “engine start / stop signal” and the “ID code” are read from the memory 103 and stored in the RAM (not shown) inside the CPU 105. Next, the CPU 105
The “engine start / stop signal” and the “ID code” are read from the memory 103, converted by a pulse width modulation (PWM) method, and output to the oscillation circuit 104.
The oscillation circuit 104 modulates and amplifies the input pulse from the CPU 105 and transmits the modulated pulse as a radio signal.

[Configuration and operation of the receiving circuit 202] FIG.
FIG. 2 is a block diagram illustrating a receiving circuit as one embodiment of the present invention.

In the figure, a receiving circuit 202 is supplied with power from a battery 211 of a vehicle body and converts the voltage to a power supply circuit 2.
08 for use at a constant voltage. The receiving circuit 20
2 is an antenna 20 for receiving a radio wave from the transmitter 100
1. a signal receiving circuit 210 for detecting and demodulating a received radio wave;
A reset circuit 209 for resetting the CPU 207 when the power is turned on, a non-volatile memory 204 storing an “engine start / stop signal”, an “ID code”, and the like, and an output circuit 206 for generating a signal for releasing an operation lock are provided.

Next, the operation of the receiving circuit 202 will be described. The CPU 207 performs initial setting after an ignition switch (not shown) is turned off, and
It is in a reception waiting state from 00. Signal receiving circuit 210
Demodulates a radio signal or noise received by the antenna 201 by a pulse width modulation (PWM) method, decodes the digital signal into digital data, and sends the digital data to the CPU 207. The CPU 207 determines whether or not the digital data from the signal receiving circuit 210 is addressed to the own receiving circuit by a process described later according to the present invention. If the digital data is addressed to its own receiving circuit, the CPU
Reference numeral 207 temporarily stores the ID code in the RAM (not shown) in the CPU 207 and determines whether or not the ID code includes a previously stored ID code. As a result, if the ID data of the own receiving circuit 202 is not included, the digital data once stored in the RAM is ignored. On the other hand, the digital data
If the ID data includes the ID data of No. 2, the digital data is further collated with an “engine start / stop signal” stored in the memory 204 in advance, and it is determined whether or not they match. If they match, it is determined that the “engine start / stop signal” and “ID code” from the transmitter 100 are present, and the ECU 203 is instructed to start or stop the engine to start or stop the engine. On the other hand, if they do not match,
The digital data once stored in the RAM is ignored. In the present embodiment, an EEPROM (electrica
lly erasable programable ROM) is used.

[Discrimination Processing of Received Data in Receiving Circuit] Next, processing for determining received data in the receiving circuit 202 will be described. FIG. 4 shows a reception signal to be received by the reception circuit 202.

FIG. 4 is a diagram showing a format of received data according to an embodiment of the present invention.

In the figure, a receiving circuit 202 includes a transmitting circuit 101.
, Three types of data are sent from
It is assumed that a 40-bit "0" or "1" data combination follows the bit "header". The 40 bits include an ID code indicating a specific receiver, a command for instructing start or stop of the engine, and the like. Since the three types of data are converted into pulses having different widths by the signal receiving circuit, the time length of the data bits differs depending on the combination of 40-bit "0" and "1". "Header",
The design value of each data of “0” and “1” is 3.2
5 mS, 2.00 mS, and 1.20 mS, and it is assumed that there is a variation of ± 20% at maximum.

In the process of determining received data according to the present embodiment,
First, it is determined whether or not the head of the pulse train of the received data falls within a range of variation (± 20%) centered on the design value of the “header” data stored in advance by measuring the pulse width of the head of the actually measured pulse train. Confirmed by comparison, according to the design values of “0” and “1” data stored in advance,
It is determined how many “0” and “1” are included in the 40-bit pulse data. Next, when the determination for 40 bits is completed, the number of “0” and “1”, the design values of the “header”, “0”, and “1” data stored in advance, and the actually measured pulse train , A predicted reception time (predicted reception data length) is calculated on the basis of the leading pulse width. Next, the predicted reception time is compared with the actually measured reception time of 40 bits (measured reception data length). If the reception times are substantially equal, the received signal is from the transmission circuit 101 to be received by the reception circuit 202. Judge. If the received data is addressed to the receiving circuit 202, the above-mentioned [Receiving circuit 2
02 Configuration and Operation]. Next, this determination processing will be described with reference to the flowchart of FIG.

FIG. 5 is a flowchart showing a process of determining received data according to an embodiment of the present invention. The received data is determined bit by bit.

In the figure, the CPU 207 includes a signal receiving circuit 2
10, the input of the pulse train of the reception data is detected by the edge of each pulse data, and the first pulse is taken in (step S1). Next, it is determined whether the data fetched in step S1 is a "header" based on the previously stored design value of the "header" and whether the data falls within a variation range thereof (step S2). Step S2
In the case of YES, the parameters such as the counter described later are initialized (step S3), the data length of the actually received “header” is stored (step S4), and the process returns to step S1 to process the subsequent data. .

If NO in step S2, step S
It is determined whether or not the data captured in step 1 is “1” based on the design value of the data “1” stored in advance (step S5). In the case of YES in step S5, 1 is added to a counter for counting the number of data "1" (step S6), and set as "1" as processing data inside CPU 207 (step S7). RA
M is temporarily stored in M (step S12). On the other hand, if NO in step S5, the same determination is made for data "0" (step S8), and if data "0", 1 is added to a counter for counting the number of data "0" (step S10). ), Set as "0" as processing data inside the CPU 207 (step S11), and temporarily store it in a RAM (not shown) (step S12). Step S
In the case of NO in step 8, since the data is not data to be received, parameters such as a counter are initialized (step S9A),
The actual value of the “header” data length stored in step S4 is cleared (step S9B), and the process returns.

Next, in step S13, step S1
Then, one data taken in this time is added to the actually measured reception data length. In step S14, it is determined whether or not the determination of "0" and "1" for all data, that is, 40 bits as data bits has been completed. If NO, the process returns to step S1 to determine subsequent data. On the other hand, YES in step S14
In the case of, the count values of the data “0” and “1” counters, the design values of the data lengths of the data “0” and “1”, the design values of the data length of the “header”, and the actual values stored in step S4 4 using the data length of the received "header"
The expected reception data length of the data of 0 bits is calculated.

For example, when there are 14 “0” and 26 “1”, the ideal design value is: T3.25 = 14 × 1.20 mS + 26 × 2.00 mS = 6
8.8 mS.

At this time, if the variation ratio is (actually measured “header” data length) / (prestored “header” data length) = 2.98 mS / 3.25 mS, the predicted received data length is: T2.98 = 68.8mS × (2.98mS / 3.25m
S) = 63.08 mS. Therefore, the predicted received data length is compared with the actually measured received data length sequentially added in step S13 (step S16), and when they are substantially equal (OK), the data stored in the RAM is sequentially interpreted (step S17) and the counter is read. Are initialized (step S17), and the process returns. On the other hand, in the case of NG, the parameters such as the counter are initialized (step S17), and the process returns.

In the present embodiment, the "header" is one pulse, but it is needless to say that a plurality of pulses may be used.

In this embodiment, the communication between the transmitter and the receiver is performed by using a radio wave medium. However, it is needless to say that the communication may be performed using, for example, infrared rays.
In that case, the oscillation circuit 104 is a circuit for converting pulse data to infrared light, the antenna 102 is an infrared light emitting element,
The signal receiving circuit 210 is replaced with an inverse conversion circuit from infrared to pulse data, and the antenna 201 is replaced with an infrared light receiving element.

<Effects of this Embodiment> (1) The received signal has a predetermined variation range (± 2) centered on the design value of each data of “header”, “0”, and “1”.
0%) and count the number of “0” and “1”, and based on those numbers, the design values of “0” and “1”, and the actually measured and designed values of “header” Then, the received data length was calculated and compared with the actually measured received data length. This makes it possible to achieve both stable reception processing over the entire frequency range in which the receiver can receive and highly accurate received data discrimination processing with excellent noise resistance. (2) Also, since it is determined whether the number of signals to be received is a predetermined number (40 in the present embodiment), it is possible to make a more accurate determination. (3) Also, since there are only three types of data to be determined, the simplification of the receiving process is realized, and the circuit and the program can be reduced. Therefore, the structure of the oscillation circuit of the transmission circuit can be made inexpensive with some variation in the oscillation clock. Further, since the reception frequency range of the receiver can be set relatively wide due to its excellent noise resistance, the reception frequency can be easily adjusted even in the manufacturing process of the reception device.

[0045]

As described above, according to the present invention,
Thus, it is possible to provide a receiving apparatus and a received data discriminating method which are excellent in noise resistance and capable of receiving data with high accuracy.

[0046]

[Brief description of the drawings]

FIG. 1 is a diagram showing an engine starter system as one embodiment of the present invention.

FIG. 2 is a block diagram illustrating a transmission circuit according to an embodiment of the present invention.

FIG. 3 is a block diagram showing a receiving circuit as one embodiment of the present invention;

FIG. 4 is a diagram showing a format of received data as one embodiment of the present invention.

FIG. 5 is a flowchart illustrating a process of determining received data according to an embodiment of the present invention.

FIG. 6 is a diagram illustrating a process of determining a received signal in a receiver of a remote control system as a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 transmitter 101 transmission circuit 102, 201 antenna 200 automobile 202 reception circuit 103, 204 EEPROM 105, 207 CPU 106, 209 reset circuit

Claims (10)

[Claims] 1. A receiving apparatus for receiving a signal group from the outside, comprising: measuring a time length of a head signal in the signal group; determining whether the signal falls within a predetermined error range; A first signal discriminating means for discriminating the first signal to be received, and a subsequent signal subsequent to the first signal based on a pre-stored reference value when the first signal discriminating means determines that the signal is the first signal to be received. And a subsequent signal discriminating means for discriminating the following. 2. When the subsequent signals include 0 information and 1 information having different time lengths, the reference values are different reference values for the 0 information and the 1 information, respectively. Means for determining the reference value of the 0 information and the 1
And determining whether the subsequent signal falls within the predetermined error range based on a reference value of the information.
The receiving device according to the above. 3. A counting means for counting the number of 0 information and 1 information determined by the subsequent signal discriminating means, respectively, and after the predetermined number of the subsequent signals are discriminated by the subsequent signal discriminating means, Based on the number of 0 information and 1 information counted by the means, the reference value of the 0 information and the reference value of the 1 information, and the measured value of the head signal and the reference value stored in advance, the time length of the subsequent signal is determined. Subsequent signal length calculation means to calculate, signal length measurement means to measure the actual time length of the subsequent signal, time length of the subsequent signal calculated by the subsequent signal length calculation means and measured by the signal length measurement means Comparing means for comparing an actual time length of the subsequent signal, and determining whether or not the signal group is a signal group to be received based on a comparison result of the comparing means. 2 notes On-board receiver. 4. The receiving apparatus according to claim 1, further comprising a number-of-subsequent-signals determining unit configured to determine whether a predetermined number of signals are included in the subsequent signals. apparatus. 5. The remote control system according to claim 1, wherein the receiving device is a receiving device of a remote control system that performs a predetermined operation by interpreting information included in the signal group. The receiving device according to the above. 6. The information included in the signal group is represented by radio waves of different frequencies. Further, prior to the discrimination by the head signal discriminating means, the signal group is converted into a predetermined data format. The receiving device according to any one of claims 1 to 5, further comprising means. 7. A received data discriminating method for receiving a signal group from outside, comprising: measuring a time length of a head signal in the signal group, discriminating whether a signal falls within a predetermined error range, and entering the error range. In this case, the received signal is determined to be a head signal to be received, and if the head signal is determined to be received, a subsequent signal following the head signal is determined based on a reference value. 8. When the subsequent signal includes 0 information and 1 information having different time lengths, the reference values are different reference values for the 0 information and the 1 information, respectively. Based on the reference value and the reference value of the one information,
8. The received data determination method according to claim 7, wherein it is determined whether the subsequent signal falls within the predetermined error range. 9. The method further includes counting the number of 0 information and 1 information included in the determined subsequent signal, determining the predetermined number of the subsequent signals, and counting the number of the counted 0 information and 1 information. Calculating a time length of the subsequent signal based on a reference value of the 0 information and a reference value of the 1 information, and a measurement value and a reference value of the head signal; measuring an actual time length of the subsequent signal; 9. The method according to claim 8, further comprising: comparing a time length of the subsequent signal with an actual time length of the subsequent signal, and determining whether the signal group is a signal group to be received based on a result of the comparison.
The received data determination method described in the above. 10. The method according to claim 7, further comprising: determining whether the subsequent signal contains a predetermined number of signals to determine whether the signal group is a signal group to be received. The received data determination method according to claim 9.