JP2014107643A - Wireless controller for on-vehicle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control On/Off of an on/off device 52 mounted on a vehicle by using wireless communication.SOLUTION: A transmission device 6 transmits a first Barker sequence at timing of turning On, and transmits a second Barker sequence at timing of turning Off. A reception device 20 for receiving a bit sequence comprises: a shift register 26 for shifting the bit sequence; a first correlation coefficient calculation device 32 for calculating a correlation coefficient with the first Barker sequence in association with the number of shifted bits; and a first comparison device 40 which checks whether or not only a correlation coefficient calculated using a specific number of bits is equal to or larger than a reference value and all of correlation coefficients calculated using the remaining numbers of bits are equal to or smaller than a reference value, and determines that a first Barker sequence is received when a result of the check is yes and performs On-control, where similar processing is performed for the second Barker sequence. Timing signals are transmitted/received without generating an error even when wireless communication is contaminated by a code inversion phenomenon caused by influence of electromagnetic noise.

Description

  An automobile is equipped with a device that is switched between on and off, for example, a semiconductor switching device that energizes a motor when switched on and stops energization of the motor when switched off. In the present specification, an on-vehicle device that is used by switching between on and off like the above-described semiconductor switching device is referred to as an on / off device. The present specification discloses a control device that switches on / off of an on / off device using wireless communication.

  The on / off device requires a control device that switches on and off. For example, a semiconductor switching device such as IGBT or MOS requires a control device that is turned on by applying a turn-on voltage to the gate electrode and turned off by applying a turn-off voltage to the gate electrode. In addition, a timing determination device (many of which is configured by a computer) that determines the timing of turning on and turning off these on / off devices is mounted on the automobile. The automobile requires a control device that turns on / off the on / off device at the timing determined by the timing determination device.

An automobile has a large number of on / off devices mounted thereon, and generates large electromagnetic noise when the on / off devices are switched on and off. In-vehicle devices are exposed to large electromagnetic noise.
Wireless communication has low resistance to electromagnetic noise. On the other hand, an on / off device mounted on the vehicle is not allowed to malfunction. In the current technology, the timing determination device and the on / off device are connected by wiring, and measures are taken to prevent the electromagnetic noise from adversely affecting the wiring.

  As described in Patent Document 1, a technique for insulating between a timing determination device and an on / off device has also been developed. In this technique, a photocoupler is incorporated in the control device, the timing determination device controls the presence or absence of light emission of the light emitting device, and the on / off device is switched on and off based on the light reception result of the light receiving device. Significant timing signals are transmitted by light, and electrical isolation is provided between the timing determination device and the on / off device. A magnetic coupler may be used in place of the photocoupler.

  Even when using a photocoupler, it is necessary to arrange the light emitting device and the light receiving device close to each other, and it is necessary to connect the timing determining device and the on / off device in a wired manner. The same applies to the magnetic coupler. The number of on / off devices mounted on the vehicle is increasing, the number of wire harnesses connecting the timing determination device and the on / off devices is increasing, and wiring / connection work is complicated.

  If wireless communication is applied to a control device that functions between the timing determination device and the on / off device, a wired connection can be eliminated. However, at present, in a vehicle exposed to large electromagnetic noise, if a signal indicating the timing to turn on or off is transmitted by wireless communication, it is possible to prevent the on / off device from malfunctioning due to electromagnetic noise being adversely affected. Absent. The current technology does not allow wireless.

As described in Patent Document 2, a technique for wireless communication is known by transmitting using a PN pattern of a primitive polynomial and calculating a correlation coefficient and calculating a correlation coefficient with an inverse polynomial of the received signal. It has been. According to this technology, it is possible to prevent the communication quality from being deteriorated due to the influence of electromagnetic noise.
However, this wireless communication technology has a problem that it requires a dedicated element called a SAW convolver, lacks versatility, and is expensive. It is difficult to apply to in-vehicle devices.

JP 2007-14161 A JP-T-2006-520132

  The present specification discloses a control device that switches on / off of an on / off device mounted on a vehicle using wireless communication. That is, a control technique that does not require a wired connection between the timing determination device and the on / off device and that can be realized at low cost without requiring a dedicated element such as a SAW convolver is disclosed.

The control device disclosed in the present specification is a device that switches on / off of an on / off device mounted on a vehicle, and includes a transmission device and a reception device.
The transmission device includes a first Barker sequence storage device, a second Barker sequence storage device, a modulation device, and a transmission antenna. At the timing of turning on the on / off device mounted on the vehicle, a radio wave obtained by modulating the first Barker sequence is transmitted from the transmission antenna. At the timing when the on-off device mounted on the vehicle is turned off, a radio wave obtained by modulating the second Barker sequence is transmitted from the transmission antenna.
The receiving device includes a receiving antenna, a demodulating device, a shift register, a first correlation coefficient calculation device, a first comparison device, a second correlation coefficient calculation device, and a second comparison device. The shift register shifts the bit position of the bit sequence received by the receiving antenna and demodulated by the demodulator. The shift register includes a device that increments the number of bits to be shifted, and performs processing such as 1-bit shift, 2-bit shift, and 3-bit shift. In the series of processing, processing for shifting the demodulated bit sequence by zero bits (that is, processing that does not shift) is also performed. The first correlation coefficient calculation device calculates a first correlation coefficient with the first Barker sequence in association with the number of bits shifted by the shift register. The first comparison device executes the on control when only the first correlation coefficient with a specific number of bits becomes a predetermined comparison result with respect to the on reference value. The second correlation coefficient calculation device calculates a correlation coefficient with the second Barker sequence in association with the number of bits shifted by the shift register. The second comparison device executes the off control when only the second correlation coefficient with a specific number of bits has a predetermined comparison result with respect to the off reference value.

The Barker sequence here has a significant difference between the autocorrelation coefficient when the time delay is zero and the autocorrelation coefficient when the time delay is not zero (corresponding to shifting bits). It means a certain PN code sequence. For example, in the case of an 11-bit Barker sequence, there are 11 types of time delay states, ranging from a time delay of zero to a state delayed by 10 bits. There are 10 states in the state where the time delay is not zero, from a 1-bit delay to a 10-bit delay. In other words, there are 10 autocorrelation coefficients when the time delay is not zero. In the case of a Barker sequence, between one autocorrelation coefficient when the time delay is zero and a plurality of autocorrelation coefficients when the time delay is not zero (10 when the Barker sequence is 11 bits). There is a noticeable difference. That is, there is one former autocorrelation coefficient at a level far from the numerical range in which the latter plurality of autocorrelation coefficients are distributed. There is a gap between them, and a threshold can be set between them. In this specification, by comparing the autocorrelation coefficient with a threshold value, a code sequence (bit sequence) that can distinguish between an autocorrelation coefficient when there is no time delay and an autocorrelation coefficient when there is a time delay. This is called the Barker series.
The modulation here is not limited to the modulation method as long as it is for transmitting the PN code sequence by radio waves. Modulation schemes such as FSK, ASK, and PSK can be used.

In the present control device, the transmission device transmits the first Barker sequence at a timing when the on-vehicle on / off device is turned on. Actually, the data is modulated and transmitted for wireless communication, but in the following, in order to avoid complications, the description is omitted with respect to modulation / demodulation.
The receiving device counts the correlation coefficient between the received bit sequence (hereinafter referred to as a received sequence) and the first Barker sequence. At that time, the shift register operates to calculate the autocorrelation coefficient of the reception sequence without shifting the bits, calculate the correlation coefficient of the reception sequence shifted by 1 bit, and the correlation coefficient of the reception sequence shifted by 2 bits. If the Barker sequence is n bits, the correlation coefficient of the received sequence shifted by n-1 bits is calculated. As a result, a correlation coefficient is calculated for each number of shifted bits.
The Barker sequence has a property that the correlation coefficient when the number of shift bits is zero is separated from the correlation coefficient group when the number of shift bits is 1 to n−1 bits. A threshold exists between the former one correlation coefficient and the latter n-1 correlation coefficient groups.
The first comparison device compares the correlation coefficient group with the ON reference value, and watches whether or not only the correlation coefficient at a specific number of shift bits has a predetermined comparison result with respect to the ON reference value. For example, the occurrence of a state in which only the correlation coefficient at a specific number of bits exceeds the on-reference value and all the correlation coefficients at the other number of bits do not exceed the on-reference value is observed. If this state occurs, it can be determined that the received sequence is the first Barker sequence. In this case, the receiving apparatus performs on control.
The transmission device transmits the first Barker sequence at a timing when the on / off device is turned on. The receiving device turns on the on / off device when receiving the first Barker sequence. This functions as a control device that turns on the on / off device at the timing of turning on.
When turning off, the second Barker sequence is used instead of the first Barker sequence. The other points are exactly the same as when turning on. If the second Barker series is used instead of the first Barker series, the off reference value is used instead of the on reference value, and the off control is used instead of the on control, the control device turns off the on / off device at the timing of turning off. It can be understood that it functions as a control device.

As described above, a running car is exposed to severe electromagnetic noise, and the received Barker series may be no longer a true Barker series due to the influence of the electromagnetic noise.
However, most of the electromagnetic noise acting on automobiles is a large-amplitude monopulse waveform (hereinafter referred to as spike-like noise), and all or most bits of the Barker series are not affected by electromagnetic noise. Electromagnetic noise affects only the bits of the part.
In the case of a Barker sequence, the characteristics described above with respect to the autocorrelation coefficient are not lost even if the sign of some bits is inverted from the true code and is no longer a true Barker sequence. That is, even if the sign of some bits is inverted from the true code and is no longer a true Barker sequence, the correlation coefficient when the number of shift bits is zero is the correlation coefficient group when the number of shift bits is not zero. The characteristic that a threshold exists between one correlation coefficient group of the former and the n-1 correlation coefficient groups of the latter is maintained. If the sign of some bits is inverted, the difference between the correlation coefficient when the number of shift bits is zero and the correlation coefficient group when the number of shift bits is not zero decreases. There is no loss of the property that there is a threshold and the two can be distinguished.
Therefore, when the first Barker sequence whose sign is inverted due to the influence of electromagnetic noise on some bits is received, only the first correlation coefficient at a specific number of shift bits is a predetermined comparison result with respect to the reference value. If the comparison result is not lost, it can be assumed that the first Barker sequence has been received. The transmission of the first Barker sequence is not overlooked by electromagnetic noise. At the time of transmission other than the first Barker sequence, only the first correlation coefficient at a specific number of shift bits does not become a predetermined comparison result with respect to the reference value. There is no misjudgment that the first Barker sequence has been received. The on / off device is not turned on except during transmission of the first Barker sequence.
The same applies to the transmission / reception of the second Barker sequence, and it is assumed that the second Barker sequence is transmitted / received if only the second correlation coefficient with a specific number of shift bits is a predetermined comparison result with respect to the reference value. In addition, the above relationship is not obtained except when the second Barker sequence is transmitted.
While it is not the timing to turn on or the timing to turn off, the transmission of the code sequence may be stopped, or a radio wave obtained by modulating a code sequence that is not a Barker sequence may be transmitted. In the latter case, an idle sequence is transmitted while it is not turned on or turned off. Even if an idle sequence is transmitted, it is not a Barker sequence, so even if it is affected by electromagnetic noise, it is not erroneously determined that a Barker sequence has been received.

  When the Barker series is used, resistance against electromagnetic noise that affects the in-vehicle device is enhanced, and transmission of the ON signal is not overlooked, and it is not mistaken that the ON signal is received during transmission other than the ON signal. Generation of transmission / reception errors can be prevented, and an on signal can be received at the timing of turning on. The same applies to the off signal, and the transmission of the off signal is not overlooked, and it is not mistaken that the off signal is received during transmission other than the off signal. An off signal can be received at the timing of turning off.

The second Barker sequence may be a completely different Barker sequence from the first Barker sequence, but may be a bit sequence obtained by inverting the first Barker sequence.
When the first Barker sequence and the second Barker sequence are inverted, the first correlation coefficient calculating device for calculating the correlation coefficient between the received sequence and the first Barker sequence, and the phase relationship between the received sequence and the second Barker sequence The second correlation coefficient calculation device for calculating the number can be configured by the same device. Since the sign is inverted, two correlation coefficients can be calculated with one correlation coefficient calculation device.
For example, an apparatus that uses a n-bit Barker sequence as a first Barker sequence, uses a sequence with each code inverted as a second Barker sequence, and calculates a correlation coefficient with the first Barker sequence in a common correlation coefficient calculation device If no noise is mixed during wireless communication, all bits match when the first Barker sequence is received, and all bits do not match when the second Barker sequence is received. When the number of matching bits is used as a correlation coefficient, a correlation coefficient “n” is calculated when the first Barker sequence is received, and a correlation integer “0” is calculated when the second Barker sequence is received. When the number of bits is shifted, an n / 2 correlation coefficient is calculated for both the first Barker sequence and the second Barker sequence.
That is, when the correlation coefficient is calculated while shifting the bits of the received sequence, the correlation coefficient near n or n is calculated for one bit number, and n / 2 or all of the other bit numbers are correlated. If the number is calculated, the first Barker sequence may be received. Similarly, if one bit number calculates a correlation coefficient of 0 or close to 0, and all other bit numbers calculate a correlation coefficient of n / 2 or close thereto, the second Barker sequence is received. Good. If the correlation coefficient with the first Barker sequence can be calculated with one correlation coefficient calculation device, the correlation coefficient with the second Barker sequence can also be calculated.

There may be various modes for the comparison method for confirming reception of the first Barker sequence by the first comparison device. As described above, in the case of the Barker sequence, when the autocorrelation coefficient is calculated while shifting the bits, the autocorrelation coefficient in one bit number is far from the group of autocorrelation coefficients in the other number of bits. . Therefore, one threshold is provided between the two, the autocorrelation coefficient at one bit number is larger (or smaller) than the threshold value, and all of the autocorrelation coefficient groups at other bit numbers are smaller (or larger) than the threshold value. ) Or not. In order to further improve the reliability, two threshold values may be set between the autocorrelation coefficient in one bit number and the autocorrelation coefficient group in the other number of bits. For example, when the autocorrelation coefficient in one bit number is large and the autocorrelation coefficient group in the other bit numbers is small, two threshold values can be provided in the gap between them. A large threshold value is close to a large autocorrelation coefficient in one bit number, and a small threshold value is close to a small autocorrelation coefficient group in another bit number. The former threshold value can be the on-first reference value, and the latter threshold value can be the on-second reference value. In this case, in the first comparison device, only the first correlation coefficient at a specific number of bits becomes a predetermined comparison result (for example, the correlation coefficient is larger than the first reference value) with respect to the on-first reference value. On control is executed when all of the first correlation coefficients in the remaining number of bits have a predetermined comparison result (for example, the correlation coefficient group is smaller than the second reference value) with respect to the on second reference value. Can be. This can reduce the possibility of erroneously determining that the Barker sequence has been received when a signal other than the Barker sequence is received.
As described above, it can be said that the correlation coefficient is high if all bits match. Conversely, if all bits do not match, it can be said that there is still a high correlation. Depending on how the correlation coefficient is defined, a higher correlation coefficient may be calculated as the correlation is higher, and a lower correlation coefficient may be calculated as the correlation is higher. When using the latter correlation coefficient, the ON first reference value is set to a level lower than the ON second reference value. In this case, only the first correlation coefficient at a specific number of bits is ON. It can be assumed that the Barker sequence is received when the first correlation coefficient is lower than the first reference value and all of the first correlation coefficients with the remaining number of bits are larger than the on-second reference value. Only the first correlation coefficient with a specific number of bits is a predetermined comparison result with respect to the on-first reference value, and all of the first correlation coefficients with the remaining number of bits are predetermined with respect to the on-second reference value. The expression to be the comparison result of
(1) Only the first correlation coefficient with a specific number of bits is larger than the on-first reference value, and all of the first correlation coefficients with the remaining number of bits are smaller than the on-second reference value;
(2) Including the case where only the first correlation coefficient at a specific number of bits is smaller than the on-first reference value and all of the first correlation coefficients at the remaining number of bits are larger than the on-second reference value. It is an expression to do.
In the second comparison device, only the second correlation coefficient with a specific number of bits is a predetermined comparison result with respect to the off first reference value, and all the second correlation coefficients with the remaining number of bits are off. The off control is executed when a predetermined comparison result is obtained with respect to the reference value. This can reduce the possibility of erroneously determining that a Barker sequence has been received when a signal other than the Barker sequence is received even when switching off. Here, the expression “a predetermined comparison result with respect to the off first reference value and a predetermined comparison result with respect to the off second reference value” means the same contents as in the above (1) and (2). doing.

Automobiles have multiple on / off devices. Therefore, when the transmission device transmits a bit sequence by wireless communication, it is preferable that an on / off device to which the bit sequence is transmitted can be designated. According to wireless communication, electromagnetic noise also affects a radio signal that designates a partner on / off device, and an on / off device that is not the original partner may malfunction. In order to prevent this, it is preferable to use a Barker sequence for a radio signal designating an on / off device.
For example, when the first on / off device is instructed to turn on, a protocol for transmitting the third Barker sequence and the first Barker sequence is used. The third Barker sequence indicates communication with the first on / off device. Since it indicates the timing when the first Barker sequence is turned on, it is possible to instruct the first on / off device to turn on by transmitting the third Barker sequence and the first Barker sequence. Similarly, it is possible to instruct the first on / off device to turn off by transmitting the third Barker sequence and the second Barker sequence. The second ON / OFF device can be associated with the fourth Barker series. In that case, the second on / off device can be commanded to turn on by transmitting the fourth Barker sequence and the first Barker sequence, and the second on / off device can be transmitted by transmitting the fourth Barker sequence and the second Barker sequence. -The off device can be commanded to turn off.
The transmission device having the above function transmits, from the transmission antenna, a radio wave obtained by modulating the Barker sequence and the first Barker sequence corresponding to the reception device at a timing at which a signal to be turned on by the specific reception device is transmitted. At a timing at which a signal to be turned off to a specific receiving device is transmitted, a radio wave obtained by modulating the Barker sequence and the second Barker sequence corresponding to the receiving device is transmitted from the transmitting antenna.
In the above, a plurality of “Barker sequences for designating a communication partner and Barker sequences for instructing on or off” are transmitted. You may transmit by a time division system, and you may transmit by a time division multiplexing system.

The reliability required for transmission of the timing signal differs depending on the type of signal. For example, in signal transmission to a device that brakes by turning on, the risk for not receiving a signal that turns on may be high, while the risk for not receiving a signal that turns off may be small. Conversely, in signal transmission to a device that increases speed by turning on, there is a small risk that a signal that turns on is not received, whereas there is a large risk that a signal that turns off is not received.
In the technique of determining whether or not a Barker sequence has been received using a correlation coefficient, the possibility of misjudgment and risk can be linked by selecting the size of a reference value to be compared with the correlation coefficient. For example, when a higher correlation coefficient is calculated for a first Barker sequence and a second Barker sequence as the correlation is higher, the following relationship can be obtained.
(3) When the risk for not receiving the ON signal is large, the ON first reference value is lowered to increase the ON second reference value, and when the risk for the OFF signal not being received is low, the OFF first reference value Increase the OFF second reference value.
(4) When the risk for not receiving the ON signal is small, the ON first reference value is increased and the ON second reference value is decreased, and when the risk for the OFF signal not being received is high, the OFF first reference value Reduce the second reference value off.
When a sequence in which the sign of the first Barker sequence is inverted is used as the second Barker sequence, and the correlation coefficient is higher as the correlation with the first Barker sequence is higher, the following relationship can be obtained.
(3a) When the risk for not receiving the ON signal is large, the ON first reference value is lowered and the ON second reference value is increased, and when the risk for not receiving the OFF signal is small, the OFF first reference value Reduce the second reference value off.
(4a) When the risk for not receiving the ON signal is small, the ON first reference value is increased and the ON second reference value is decreased, and when the risk for not receiving the OFF signal is large, the OFF first reference value Increase the OFF second reference value.
In order to respond to the above request, it is preferable that the transmission device transmits, from the transmission antenna, a radio wave obtained by modulating a reference value used in the comparison device for each type of Barker sequence. The communication is not required to be instantaneous and can be sent in advance. This is because if the reference value is not correctly received due to the influence of electromagnetic noise, it can be retransmitted. When transmitting the reference value, it is not always necessary to use the Barker sequence.

  According to the technology disclosed in this specification, it is possible to transmit on-timing and off-timing to an on-off device mounted on a vehicle using wireless communication. It is possible to eliminate the need to wire and connect to an on / off device that had to be wired to avoid the influence of electromagnetic noise.

The figure which shows the system configuration | structure of the control apparatus which utilizes radio | wireless communication. The figure which shows the relationship between the shift number of a bit, and the autocorrelation coefficient of a Barker series. The figure explaining the magnitude relationship between a correlation coefficient and a reference value. The figure which shows the process sequence which judges the presence or absence of reception of a Barker series. The figure which shows the allocation method of a Barker series.

The main features of the embodiments described below are listed.
Feature 1: The Barker sequence here is not only a pure Barker sequence but also a blank band between a correlation coefficient at a specific number of shift bits and a correlation coefficient group at another number of shift bits. It includes quasi-Barker sequences that have the property that a threshold can be set within the band.
Feature 2: The Barker sequence mentioned here is a sequence in which a 7-bit Barker sequence, an 11-bit Barker sequence, and a 13-bit Barker sequence are connected in an arbitrary order. For example, six types of Barker sequences 7-11-13, 7-13-11, 11-7-13, 11-13-7, 13-7-11, and 13-11-7 are used. The number indicates the number of bits of the Barker sequence as a unit. The order of 7-7-7, 7-7-11, 7-7-13... 13-13-13 is adopted, and 27 types of Barker sequences can be used. The number of unit barker sequences to be used in combination is determined according to the number of types of necessary barker sequences.

(Barker series)
FIG. 2 shows the nature of the Barker sequence, taking the case of “1110010”, which is a 7-bit Barker sequence, as an example. The column 60 shown in the figure shows the Barker sequence after the bit shift. When the number of shift bits is zero, it becomes “1110010”, and when the number of shift bits is 1, it becomes “0111001”. The same applies to the following, and when the number of shift bits is 6, “1100101” is obtained. The column 62 shown in the figure shows the processing contents of the apparatus that processes each bit to calculate the autocorrelation coefficient. If the 7-bit Barker sequence “1110010” is correctly received, the received Barker sequence and the transmitted Barker sequence are completely correlated, in which case the maximum autocorrelation coefficient is calculated. I try to do it. That is, if the first bit is 1, it is 1 if the 2nd bit is 1, 1 if the 3rd bit is 1, 1 if the 4th bit is 0, and 1 if the 5th bit is 0. If it is 0, it is 1; if the 6th bit is 1, it is 1; if the 7th bit is 0, it is 1, and the values obtained in this way are summed to obtain the correlation coefficient. . In the column 62, the 1 is transmitted as it is to the 1 bit in the transmitted Barker sequence (that is, a non-inverting circuit is prepared), and the inverted 1 bit is transmitted (that is, the inverting circuit is transmitted). A processing circuit is prepared. A column 64 indicates the processing result for each bid, and a column 66 indicates the obtained correlation coefficient. The numbers in the 66 column are the sum (Σ) of the 64 columns.

When the Barker sequence “1110010” is correctly received, the correlation coefficient calculated by setting the number of shift bits to zero is 7. The maximum correlation coefficient (7 in this case) is obtained when the code transmitted in all bits matches the received code.
On the other hand, when the correlation coefficient between the sequence shifted by 1 bit and the transmitted Barker sequence is calculated, there is a bit that does not match the matching bit, and the correlation coefficient is 3. For example, the first bit of the series shifted by 1 bit is 0. This bit should be 1, and column 64 is 0 because it does not match. The processing circuit in column 62 calculates 1 for bits that match the transmitted Barker sequence and 0 for bits that do not match.
Similarly, the correlation coefficients calculated after shifting from 2 bits to 6 bits are all 3. The value “3” here indicates that the number of matching bits is 3, and the number of mismatching bits is 4. As will be described later, if all 7 bits do not match, there is a correlation. The state where the number of matching bits is 3 and the number of non-matching bits is 4 corresponds to a state where no correlation is recognized. A correlation coefficient of “3” corresponds to a state where no correlation is recognized.
As is apparent from FIG. 2, in the case of “1110010”, which is a 7-bit Barker sequence, only the correlation coefficient at a specific number of shift bits (in this case, 0) is a value indicating a strong correlation, and other shift bit numbers The correlation coefficient group in all (1 to 6 in this case) is a value (3 in this case) indicating a weak correlation.
The above property is recognized for all Barker sequences, and is also recognized for “11100010010”, which is an 11-bit Barker sequence, and “1111100110101”, which is a 13-bit Barker sequence.

  The bit processing content shown in the column 62 is 1 if the first bit of the received Barker sequence is 1, 1 if the second bit is 1, and 1 if the third bit is 1. Outputs 1 if the 4th bit is 0, outputs 1 if the 5th bit is 0, outputs 1 if the 6th bit is 1, and outputs 1 if the 7th bit is 0 1 is output. This means that when the received bit sequence is “1110010”, the processing result of all the bits is 1, and the correlation coefficient is maximized. The processing content of the column 62 corresponds to counting the number of bits whose received sequence matches the sequence of “1110010”. When all bits match, a value of 7 is calculated. In this embodiment, the number of coincidence bits is used as a correlation coefficient.

  Actually, the number of shift bits between the transmitted Barker sequence and the received Barker sequence is not known. However, if the autocorrelation coefficient is calculated while incrementing the number of shift bits to 0, 1, 2, 3,..., If the received sequence is a Barker sequence, only the correlation coefficient at the specific number of shift bits is the residual The relationship is far from the correlation coefficient group in the number of shift bits. This is a phenomenon that is recognized only when the received sequence is a Barker sequence, and the above phenomenon cannot be obtained even if a sequence other than the Barker sequence is received. If only the correlation coefficient at a specific number of shift bits is far from the correlation coefficient group at the remaining number of shift bits, the Barker sequence is received.

FIG. 2 also illustrates a case where a series obtained by inverting “1110010”, which is a 7-bit Barker series, is used as the second Barker series. The column 70 shown in the figure shows the second Barker sequence after the bit shift. When the number of shift bits is zero, it becomes “0001101”, and when the number of shift bits is 1, it becomes “1000110”. The same applies hereinafter. The column 62 shown is the same as the bit processing content described when calculating the correlation coefficient of the first Barker sequence. An apparatus for calculating the correlation coefficient of the first Barker sequence can be used as the apparatus for calculating the correlation coefficient of the second Barker sequence. When the 7-bit second Barker sequence “0001101” is correctly received, the received second Barker sequence and the Barker sequence for calculating the correlation coefficient are completely correlated (inverted for all bits). In this case, the minimum autocorrelation coefficient is calculated. That is, if the first bit is 0, it is 0, and if the second bit is 0, it is 0. If the 3rd bit is 0, it is 0. If the 4th bit is 1, it is 0. If it is 1, it will be 0 if the 6th bit is 0, 0 if the 7th bit is 1, and the correlation coefficient will be obtained by summing the values thus obtained. . In the column 62, the 0 is transmitted as it is to the 0 bit in the transmitted Barker sequence (that is, a non-inverting circuit is prepared), and the inverted 1 bit is transmitted (that is, the inverting circuit is transmitted). A processing circuit is prepared. The column 74 indicates the processing result for each bid, and the column 76 indicates the obtained correlation coefficient.
When the second Barker sequence “0001101” is correctly received, the correlation coefficient calculated by setting the number of shift bits to zero is zero. The minimum correlation coefficient (0 in this case) is obtained when the code compared with the code transmitted in all bits does not match.
On the other hand, when the correlation coefficient of the second Barker sequence shifted by 1 bit and the Barker sequence to be compared are calculated, there are bits that do not match and bits that do not match, and the correlation coefficient is 4.
The bit processing content shown in the column 62 is 0 if the first bit of the received Barker sequence is 0, 0 if the second bit is 0, and 0 if the third bit is 0. Outputs 0 if the 4th bit is 1, outputs 0 if the 5th bit is 1, outputs 0 if the 6th bit is 0, and 1 if the 7th bit is 1. 0 is output. This means that when the received Barker sequence is “0001101”, the processing result of all bits is 0, and the correlation coefficient is minimum. The processing content of the column 62 corresponds to counting the number of bits whose received sequence matches the sequence of “1110010”. A value of 0 is calculated when all bits do not match.

The bit processing content shown in the column 62 is equivalent to counting the number of bits matching the “1110010” series. If all bits match, it becomes 7, indicating that they are completely correlated. If all bits do not match, it becomes 0, indicating that this is also completely correlated. When there is no correlation, the number of matching bits is 3 or 4, and the number of mismatching bits is 4 or 3.
When the correlation coefficient is calculated for a sequence shifted from “1110010” or “0001101”, it becomes 3 or 4, indicating that there is no correlation.
The processing circuit (part of the correlation coefficient calculation circuit) shown in the column 62 may be the reverse of that in FIG. That is, a processing circuit in which inversion, inversion, inversion, non-inversion, non-inversion, inversion, and non-inversion circuits are arranged in order from the first bit side may be used. In this case, when the first Barker sequence is correctly received, one of the seven correlation coefficients calculated while changing the number of shift bits is 0, and the other six correlation coefficients are 4. Further, when the second Barker sequence is correctly received, one of the seven correlation coefficients calculated while changing the number of shift bits is 7, and the other six correlation coefficients are 3 It becomes. The correspondence between the level of the correlation and the magnitude of the correlation coefficient can be freely adjusted by the circuit configuration of the correlation coefficient calculation circuit.

The vertical axis in FIG. 3A indicates the calculated first correlation coefficient Σ.
(5) When the first Barker sequence is correctly received, the correlation coefficient Σ at the specific number of shift bits is 7 which is the maximum value, and the correlation coefficient Σ at other shift bit numbers (there are 6 types) is The intermediate value is 3.
The broken line in FIG. 3B indicates the calculated second correlation coefficient.
(6) When the second Barker sequence is correctly received, the correlation coefficient Σ at a specific number of shift bits is 0, which is the minimum value, and the correlation coefficient Σ at other shift bit numbers (there are six types) is The intermediate value is 4.

Using the above characteristics of a Barker sequence, it is determined whether the received sequence is a Barker sequence.
(7) If the correlation coefficient Σ at a specific number of shift bits is far from the distribution range of the correlation coefficient Σ at other shift bit numbers, it is a Barker sequence.
(8) For example, if only the correlation coefficient at a specific number of shift bits is 6 or more and all of the correlation coefficients Σ in the remaining number of shift bits are 5 or less, the first Barker sequence,
(9) For example, if only the correlation coefficient at a specific number of shift bits is 1 or less and all of the correlation coefficients Σ in the remaining number of shift bits are 2 or more, it is understood that the second Barker sequence is used. .
As described above, depending on how the correlation coefficient calculation circuit is set, when the first Barker sequence is correctly received, the correlation coefficient Σ at a specific number of shift bits is 0, which is the minimum value, and other shifts. The correlation coefficient Σ in the number of bits (there are six types) is an intermediate value of 4, and when the second Barker sequence is correctly received, the correlation coefficient Σ at a specific number of shift bits is the maximum value. Thus, the correlation coefficient Σ in other shift bit numbers (there are six types) can be obtained as a relationship of 3 being an intermediate value. The relationship between the comparison result with the threshold value and the determination result of whether it is the first Barker sequence, the Barker sequence or the second Barker sequence is not uniform, and the correlation is It should reflect the correspondence between the height and the correlation coefficient.

  In the above, in order to simplify the description, the case of a 7-bit Barker sequence has been exemplified. When 7-bit Barker sequences are connected in series, 14-bit, 21-bit, etc. Barker sequences are obtained. An 11-bit Barker sequence and a 13-bit Barker sequence are also known. When they are connected in series in various combinations, a plurality of types of multi-bit Barker sequences can be prepared.

For the sake of simplicity, a 21-bit first Barker sequence in which three 7-bit Barker sequences are connected in series will be described below.
(10) As shown in FIG. 3 (c), when the first Barker sequence is correctly received, the correlation coefficient Σ at a specific number of shift bits is the maximum value 21, and the number of other shift bits (20 The correlation coefficient Σ is 9 as an intermediate value.
(11) It is assumed that the sign of one bit is inverted due to the influence of electromagnetic noise during transmission / reception of the first Barker sequence. In that case, the correlation coefficient Σ at a specific number of shift bits decreases to 20, and all of the correlation coefficients Σ at other shift bit numbers increase to 10.
(12) It is assumed that, during transmission / reception of the first Barker sequence, the sign of 2 bits thereof is inverted due to the influence of electromagnetic noise. In that case, the correlation coefficient Σ at a specific number of shift bits decreases to 19, and the correlation coefficient Σ at other shift bit numbers increases to 11.
(13) Similarly, as the number of bits inverted by electromagnetic noise increases, the correlation coefficient Σ at a specific number of shift bits decreases, and the correlation coefficient Σ at other shift bit numbers increases.
(14) For example, if a 4-bit code is inverted, the correlation coefficient Σ at a specific number of shift bits decreases to 17, and the correlation coefficient Σ at other shift bit numbers increases to 13.
(15) Nevertheless, the property that the correlation coefficient Σ at a specific number of shift bits is far from the distribution area of the correlation coefficient Σ at other shift bit numbers is not lost. In FIG. 3, the horizontal axis indicates the number of received bits with the sign inverted due to the influence of electromagnetic noise. When a 21-bit Barker sequence is used and the sign of 4 bits is inverted, the correlation coefficient Σ at a specific number of shift bits decreases to 17, and the correlation coefficient Σ at other shift bit numbers increases to 13. I understand that. Nevertheless, the property that the correlation coefficient Σ at a specific number of shift bits is far from the distribution area of the correlation coefficient Σ at other shift bit numbers is not lost.
(16) From the above, when a Barker sequence is transmitted / received, even if the sign of some bits is inverted in the process of transmission / reception, the correlation coefficient Σ at a specific number of shift bits is a phase at other shift bit numbers. By determining whether or not there is a property of being far from the distribution range of the relation number Σ, it is possible to determine whether a Barker sequence is transmitted or received or another sequence is transmitted or received. In the case of FIG. 3C, by determining whether only the correlation coefficient Σ at a specific number of shift bits is 16 or more and all the correlation coefficients Σ at other shift bit numbers are 14 or less, It is possible to determine whether a Barker sequence is transmitted / received or another bit sequence is transmitted / received.

  Although automobiles are exposed to severe electromagnetic noise, the electromagnetic noise is strong noise in a short time (it can be said that it is spike noise, burst noise, or large amplitude monopulse noise). When a bit sequence is transmitted / received, even if some bits are affected, most bits are not affected. Even if the sign of a part of the Barker sequence is inverted even if the sign of the Barker sequence is reversed, the correlation coefficient Σ at a specific number of shift bits is the same as that at other shift bit numbers. When combined with the property that the property of being separated from the distribution range of the relation number Σ is maintained, it becomes possible to transmit the operation timing by wireless communication to the on / off device mounted on the vehicle.

  For example, if the first Barker sequence is transmitted at the timing of the on operation, even if the sign of some bits is inverted in the process of transmission and reception, in the case of FIG. The first Barker sequence is received by determining whether only the correlation coefficient Σ is 16 or more and all of the correlation coefficients Σ in the other shift bit numbers are 14 or less. It can be determined whether an inverted sequence has been received) or not a Barker sequence. By adopting a method that counts the correlation coefficient between the received bit sequence and Barker sequence and compares it with a reference value, whether or not the first Barker sequence is transmitted / received even if the sign inversion phenomenon is mixed Judgment can be made.

The same applies to transmission / reception of the second Barker sequence obtained by inverting the first Barker sequence. In the following, it is assumed that the second Barker sequence is transmitted at the timing of the off operation. Further, the correlation coefficient calculation apparatus is assumed to be the one described above. That is, a device for calculating an autocorrelation coefficient unique to the second Barker sequence is not used, and a device for calculating the autocorrelation coefficient of the first Barker sequence is used. The following description explains the phenomenon shown by the broken line in FIG.
(17) When the second Barker sequence is correctly received, the correlation coefficient Σ at a specific number of shift bits is 0, which is the minimum value, and the correlation coefficient Σ at other shift bit numbers (there are 20 types) is The intermediate value is 12. In FIG. 3C, in order to avoid the intersection of the solid line and the broken line, the vertical axis of the solid line is shifted from the vertical axis of the broken line.
(18) It is assumed that the sign of one bit is inverted due to the influence of electromagnetic noise during transmission / reception of the second Barker sequence. In that case, the correlation coefficient Σ at a specific number of shift bits increases to 1, and all the correlation coefficients Σ at other shift bit numbers decrease to 11.
(19) It is assumed that, during transmission / reception of the second Barker sequence, the sign of 2 bits thereof is inverted due to the influence of electromagnetic noise. In that case, the correlation coefficient Σ at a specific number of shift bits increases to 2, and all of the correlation coefficients Σ at other shift bit numbers decrease to 10.
(20) Similarly, as the number of bits inverted by electromagnetic noise increases, the correlation coefficient Σ at a specific number of shift bits increases, and the correlation coefficient Σ at other shift bit numbers decreases.
(21) For example, if a 4-bit code is inverted, the correlation coefficient Σ at a specific number of shift bits increases to 4, and the correlation coefficient Σ at other shift bit numbers decreases to 8.
(22) Nevertheless, the property that the correlation coefficient Σ at a specific number of shift bits is far from the distribution area of the correlation coefficient Σ at other shift bit numbers is not lost. As shown in FIG. 3C, when the sign of 4 bits of the 21-bit second Barker sequence is inverted, the correlation coefficient Σ at a specific number of shift bits increases to 4, The correlation coefficient Σ in the number of shift bits decreases to 8, but there is still a blank band between the two.
(23) From the above, when a Barker sequence is transmitted / received, even if the sign of some bits is inverted during the transmission / reception process, the correlation coefficient Σ at a specific number of shift bits is a phase at other shift bit numbers. By determining whether or not there is a property of being far from the distribution range of the relation number Σ, it is possible to determine whether a Barker sequence is transmitted or received or another sequence is transmitted or received. In the case of FIG. 3C, by determining whether only the correlation coefficient Σ at a specific number of shift bits is 5 or less and all the correlation coefficients Σ at other shift bit numbers are 7 or more, It is possible to determine whether the second Barker sequence is transmitted / received or another bit sequence is transmitted / received.
By adopting a method that counts the correlation coefficient between the received bit sequence and Barker sequence and compares it with a reference value, whether or not the second Barker sequence is transmitted / received even if the sign inversion phenomenon is mixed Judgment can be made.

  In the above, when the sign of 4 bits is inverted during transmission / reception of the 21-bit first Barker sequence, the correlation coefficient Σ at a specific number of shift bits decreases to 17, and the other shift bit numbers An example in which all the correlation coefficients Σ are increased to 13 is shown. In the case of the example, it was shown that it is possible to determine whether or not the first Barker has been received by setting one threshold value (for example, 15) between the two. In order to further improve the reliability, there is a gap between the correlation coefficient at a specific number of shift bits and the distribution area of the correlation coefficient at other shift bits. Can be increased. In FIG. 3C, an ON first reference value is set immediately below the correlation coefficient Σ with a specific number of shift bits, and the ON second value is set immediately above the distribution area of the correlation coefficient Σ with the remaining shift bits. The case where the reference value is set is shown. On first reference value> on second reference value. In this case, it is determined whether only the correlation coefficient at a specific number of shift bits is equal to or greater than the on first reference value, and all of the correlation coefficients at the remaining number of shift bits are equal to or less than the on second reference value. Is introduced. Accordingly, it is possible to reduce the possibility of erroneously determining that the first Barker sequence has been received when receiving a sequence other than the Barker sequence. In the above example, the first Barker sequence indicates the on timing. Therefore, in FIG. 3C, the on-first reference value and the on-second reference value are indicated.

  With the same method, it is possible to reduce the possibility of erroneous determination that the second Barker sequence has been received when receiving a sequence other than the Barker sequence. In FIG. 3C, an off first reference value is set immediately above the correlation coefficient Σ at a specific number of shift bits, and the off second reference value is set just below the distribution area of the correlation coefficient Σ at the remaining number of shift bits. The case where the reference value is set is shown. OFF first reference value <OFF second reference value. In this case, it is determined whether only the correlation coefficient with a specific number of shift bits is less than or equal to the off first reference value, and all of the correlation coefficients with the remaining number of shift bits are greater than or equal to the off second reference value. Is introduced. Accordingly, it is possible to reduce the possibility of erroneously determining that the second Barker sequence has been received when receiving a sequence other than the Barker sequence.

When compared with the reference value, the magnitude of the reference value affects the determination result. In the case of the previous example, for example,
(24) If the ON first reference value is increased and the ON second reference value is decreased, the possibility of erroneous determination that the first Barker sequence has been received when receiving a sequence other than the Barker sequence can be reduced.
(25) Conversely, if the ON first reference value is lowered and the ON second reference value is increased, the possibility of erroneous determination that the first Barker sequence was not received during transmission of the first Barker sequence can be reduced. .
The need to avoid misjudgment depends on the function of the on / off device. Some braking devices have a higher need for avoiding a phenomenon that does not operate accidentally than a need for avoiding a phenomenon that operates erroneously. That is, there are some cases where it is more necessary to avoid the erroneous determination of (25) than the erroneous determination of (24). Therefore, it is preferable to increase the ON second reference value by decreasing the ON first reference value. By adjusting the reference value, it is possible to adjust to a required characteristic.
Similarly,
(26) If the off first reference value is lowered and the off second reference value is raised, the possibility of erroneous determination that the second Barker sequence has been received when a sequence other than the second Barker sequence is received can be reduced.
(27) Conversely, if the off first reference value is increased and the off second reference value is decreased, the possibility of erroneous determination that the second Barker sequence was not received during the transmission of the second Barker sequence can be reduced. .
Some braking devices have a higher need for avoiding accidental turn-off than that for avoiding accidental turn-off. In other words, there are cases where it is more necessary to avoid the erroneous determination of (26) than the erroneous determination of (27). Therefore, it is preferable to increase the OFF second reference value by decreasing the OFF first reference value. It is possible to adjust to the required characteristics by adjusting the off reference value.

FIG. 1 shows a system configuration of a control device 48 that is between the timing determination device 50 and the on / off device 52 and switches the on / off device 52 on and off at the timing determined by the timing determination device 50. The control device 48 includes the transmission antenna 14 and the reception antenna 22,
Use wireless communication. The transmission device 6 can be placed in the vicinity of the timing determination device 50, and the reception device 20 can be placed in the vicinity of the on / off device 52. There is no need to connect the timing determination device 50 and the on / off device 52 by wire.

  The timing determination device 50 outputs a signal indicating that it is a timing to transmit an ON signal to the input terminal 2 at a timing when the ON / OFF device 52 is turned ON. In addition, the timing determination device 50 outputs a signal indicating that it is a timing to transmit an off signal to the input terminal 4 at a timing at which the on / off device 52 is turned off.

The transmission device 6 includes a first Barker sequence storage device 8 and a second Barker sequence storage device 10.
The second Barker sequence may be an inversion of the first Barker sequence, but in the embodiment of FIG. 1, a completely different Barker sequence is used. When the ON signal transmission timing instruction signal is input to the terminal 2, the transmission device 6 reads the first Barker sequence from the first Barker sequence storage device 8, modulates the read first Barker sequence with the modulation device 12, and performs modulation. The transmitted signal is transmitted from the transmission antenna 14. When the off signal transmission timing instruction signal is input to the terminal 4, the transmission device 6 reads the second Barker sequence from the second Barker sequence storage device 8 and modulates the read second Barker sequence by the modulation device 12. The modulated signal is transmitted from the transmission antenna 14.

The receiving device 20 includes a receiving antenna 22 and a demodulating device 24, receives the radio signal transmitted by the transmitting antenna 14 with the receiving antenna 22, demodulates the received signal with the demodulating device 24, and demodulates the bit sequence.
The transmission device 6 and the reception device 20 are mounted on the vehicle and receive the radio wave 16 affected by the electromagnetic noise 18. Due to the influence of the electromagnetic noise 18, some bits of the bit sequence demodulated by the demodulator 24 may be inverted from the sign of the transmitted Barker sequence.

  The bit position of the bit sequence demodulated by the demodulator 24 is shifted by the shift register 26. As described in the column 60 or 70 of FIG. 2, the shift register 26 includes a bit sequence shifted by 0 bits, a bit sequence shifted by 1 bit, a bit sequence shifted by 2 bits,..., A bit shifted by n−1 bits. Output series. Here, n is the number of bits of the first Barker sequence and the second Barker sequence.

  The bit sequence whose bit position is shifted by the shift register 26 is sent to the first phase relationship calculation device 32. The first phase relationship calculation device 32 is connected to the first Barker sequence storage device 28 and compares the bit sequence sent from the shift register 26 with the first Barker sequence stored in the first Barker sequence storage device 28. , Count the number of bits with the same sign. The details are as described in relation to the columns 60, 62, 64, 66 of FIG. The first phase relationship calculation device 32 stores n correlation coefficients. That is, calculation is performed from the correlation coefficient when the shift bit number in the shift register 26 is 0 to the correlation coefficient when the shift bit number is n-1.

The n correlation coefficients are sent to the first comparison device 40. The first comparison device 40 is connected to the on-reference value storage device 36 and performs the following comparison.
(28) Only one of the n correlation coefficients is greater than or equal to the on-reference value,
(29) Are all the remaining n-1 correlation coefficients less than the on-reference value?
If both are established, the on-control execution device 44 is operated assuming that the first Barker sequence has been received. Thereby, the on / off device 52 is turned on. For example, when the on / off device 52 is a MOS transistor, the on control execution device 44 applies an on voltage to the gate electrode of the MOS.

  As described above, when the Barker sequence is transmitted and the comparison methods (28) and (29) are adopted, the first Barker sequence is transmitted and received even if a sign inversion phenomenon occurs in some bits during transmission and reception. Is called. Even if an error is mixed in wireless communication due to electromagnetic noise, the on / off device 52 can be turned on at the stage determined by the timing determination device 50. The on reference values used in the above (28) and (29) may be the same reference values as shown in FIGS. Alternatively, as shown in FIG. 3C, the reference value used in the comparison (28) and the reference value used in the comparison (29) may be separated.

  The n bit sequences whose bit positions are shifted by the shift register 26 are also sent to the second phase relationship calculation device 34. The second phase relationship calculation device 34 is connected to the second Barker sequence storage device 30 and compares the bit sequence sent from the shift register 26 with the second Barker sequence stored in the second Barker sequence storage device 30. , Count the number of bits with the same sign. The second phase relationship calculation device 42 calculates n correlation coefficients. That is, calculation is performed from the correlation coefficient when the shift bit number in the shift register 26 is 0 to the correlation coefficient when the shift bit number is n-1.

The n correlation coefficients are sent to the second comparison device 42. The second comparison device 42 is connected to the off reference value storage device 38 and performs the following comparison.
(30) Only one of the n correlation coefficients is greater than or equal to the off reference value,
(31) Are all the remaining n-1 correlation coefficients less than the off-reference value?
When both are established, the off control execution device 46 is operated as having received the second Barker sequence. As a result, the on / off device 52 is turned off. For example, when the on / off device 52 is a MOS transistor, the off control execution device 46 discharges the electric charge charged in the MOS gate electrode.

  As described above, when the Barker sequence is transmitted and the comparison methods (30) and (31) are adopted, the second Barker sequence is transmitted and received even if a sign inversion phenomenon occurs in some bits during transmission and reception. Is called. Even if an error is mixed in wireless communication due to electromagnetic noise, the on / off device 52 can be turned off at the stage determined by the timing determination device 50. The off reference value used in the comparison of the above (30) and (31) may be the same reference value as shown in FIGS. Alternatively, as shown in FIG. 3C, the reference value (30) and the reference value (31) may be separated.

  In the embodiment of FIG. 1, the first and second Barker sequences are irrelevant. In this case, both the first correlation coefficient calculation device 32 and the second correlation coefficient calculation device 34 are required. On the other hand, a bit sequence obtained by inverting the sign of the first Barker sequence can be used as the second Barker sequence. In this case, a common correlation coefficient calculation device can be used. In this case, as shown in FIG. 3C, the magnitude relationship of the correlation coefficient with respect to the second Barker sequence is opposite to the magnitude relationship of the correlation coefficient with respect to the first Barker sequence. In consideration of this, as long as the comparison contents of the second comparison device 42 are determined, exactly the same operation can be obtained.

FIG. 4 illustrates a comparison procedure by the first comparison device 40. (A) has shown the process sequence which discriminate | determines whether the 1st Barker series was received using the single on reference value, as shown to (a) and (b) of FIG. FIG. 3B shows a processing procedure for determining whether or not the first Barker sequence has been received using two types of on-reference values, as shown in FIG.
Either (a) or (b) may be used to determine whether or not the second Barker sequence has been received.

FIG. 5 shows the assignment of Barker sequences.
(A) shows an allocation example in which the first Barker sequence is transmitted at the timing of turning on and the second Barker sequence is transmitted at the timing of turning off. The first Barker series and the second Barker series are completely different types.
(B) shows an allocation example in which a Barker sequence in which the sign of the Barker sequence sent at the timing of turning on is inverted is transmitted at the timing of turning off.
(C) shows a case where only one transmitting device 6 is prepared while a plurality of receiving devices 20 and a plurality of on / off devices 52 exist. (C) shows a case where the transmission device 6 controls three on / off devices 52. In this case, it is necessary to indicate which on / off device 52 the on signal or off signal transmitted by the transmission device 6 is for. In the embodiment of (c), if the third Barker sequence is transmitted following the on signal or the off signal, it indicates that the signal is for the on / off device 52 indicated by ID3, and is followed by the on signal or the off signal. If the fourth Barker sequence is transmitted, it indicates that the signal is for the on / off device 52 indicated by ID4. If a unique Barker sequence is assigned to each on / off device 52, a plurality of on / off devices 52 can be controlled by one transmission device 6. As described above, when a Barker sequence is used, transmission / reception of the Barker sequence may be erroneously determined or the type of Barker sequence transmitted / received may be erroneously determined even if noise whose code is inverted by some bits is mixed. Unlikely. Even if the control target apparatus is instructed by wireless communication, it is possible to prevent the instruction from being erroneously transmitted.
(D) is an alternative to (c), in which the sixth Barker sequence is transmitted when the on / off device 52 indicated by ID6 is turned on, and the seventh Barker is indicated when the on / off device 52 indicated by ID6 is turned off. An example of an allocation relationship in which the eighth Barker sequence is transmitted at the timing when the sequence is transmitted and the on / off device 52 indicated by ID7 is turned on, and the ninth Barker sequence is transmitted at the timing when the on / off device 52 indicated by ID7 is turned off. doing. By using the allocation relationship, it is possible to control on / off of the plurality of on / off devices 52.

As described above, the reference value used in the first comparison device 40 or the second comparison device 42, that is, the tolerance for the sign inversion at the time of transmission / reception depending on the contents stored in the on-reference value storage device 36 and the off-reference value storage device 38. Is different. The reference values stored in the on-reference value storage device 36 and the off-reference value storage device 38 are preferably set for each on / off device in consideration of the function and personality of the on / off device 52. .
In addition, the tolerance for the sign inversion varies depending on the traveling state of the automobile. If the vehicle is running, the signal for turning on the braking device should not be transmitted, whereas if the vehicle is stopped, it is allowed that the signal for turning on the braking device is not transmitted. Therefore, there can be a technique of sending an instruction to increase or decrease the reference values stored in the on reference value storage device 36 and the off reference value storage device 38 from another control device.

If a time delay is allowed for the change of the reference value, the new reference value or the like may be sent by normal wireless communication. The reference value can be switched after checking for communication errors. On the other hand, a time delay may not be allowed until the reference value is changed. In this case, a Barker sequence can be assigned to the reference value. As a result, the new reference value can be communicated wirelessly without error.
In the above description, an embodiment in which ON control or OFF control is performed by reception of a Barker sequence has been described. Alternatively, a protocol that “reception of the first Barker sequence = 1 reception and reception of the first Barker sequence = 0 reception” is also possible. When this protocol is used, the present technology can be used for general-purpose data communication.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

2: input terminal 4: input terminal 6: transmitting device 8: first Barker sequence storage device 10: second Barker sequence storage device 12: modulation device 14: transmitting antenna 16: radio wave 18 for radio communication 18: electromagnetic noise 20: receiving device 22: reception antenna 24: demodulator 26: shift register 28: first Barker sequence storage device 30: second Barker sequence storage device 32: first correlation coefficient calculation device 34: second correlation coefficient calculation device 36: ON reference Value storage device 38: OFF reference value storage device 40: first comparison device 42: second comparison device 44: ON control execution device 46: OFF control execution device 48: control device 50: timing determination device 52: ON / OFF device

Claims (5)

It is a control device that switches on and off of the on-off device mounted on the vehicle,
A transmitter and a receiver,
The transmission device includes a first Barker sequence storage device, a second Barker sequence storage device, a modulation device, and a transmission antenna, and transmits a radio wave obtained by modulating the first Barker sequence from the transmission antenna at a turn-on timing and turns it off. The radio wave which modulated the 2nd Barker series with is transmitted from the transmitting antenna,
The reception device includes a reception antenna, a demodulation device, a shift register, a first correlation coefficient calculation device, a first comparison device, a second correlation coefficient calculation device, and a second comparison device,
The shift register includes a device that shifts the bit position of the bit sequence received by the receiving antenna and demodulated by the demodulator, and increments the number of shift bits.
The first correlation coefficient calculating device calculates a first correlation coefficient with the first Barker sequence in association with the number of bits shifted by the shift register,
The first comparison device performs ON control when only the first correlation coefficient with a specific number of bits becomes a predetermined comparison result with respect to the ON reference value,
The second correlation coefficient calculating device calculates a correlation coefficient with the second Barker sequence in association with the number of bits shifted by the shift register,
The second comparison device performs off control when only a second correlation coefficient with a specific number of bits has a predetermined comparison result with respect to an off reference value.   2. The control apparatus according to claim 1, wherein the second Barker sequence is a bit sequence obtained by inverting the first Barker sequence. In the first comparison device, only the first correlation coefficient with a specific number of bits is a predetermined comparison result with respect to the on first reference value, and all the first correlation coefficients with the remaining number of bits are on. On-control is executed when a predetermined comparison result is obtained with respect to the reference value,
In the second comparison device, only the second correlation coefficient with a specific number of bits is a predetermined comparison result with respect to the off first reference value, and all the second correlation coefficients with the remaining number of bits are off. The control device according to claim 1, wherein the off control is executed when a predetermined comparison result is obtained with respect to the reference value. The transmitting device is intended for a plurality of receiving devices,
At the timing of transmitting an ON signal to a specific receiving device, a radio wave obtained by modulating the Barker sequence and the first Barker sequence corresponding to the receiving device is transmitted from the transmitting antenna,
4. The radio wave modulated by the Barker sequence and the second Barker sequence corresponding to the receiving device is transmitted from the transmitting antenna at a timing at which the off signal is transmitted to the specific receiving device. The control device according to item 1. 5. The control device according to claim 1, wherein the transmission device transmits, from the transmission antenna, a radio wave obtained by modulating a reference value used in the comparison device for each type of Barker sequence.

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