JP2006083604A - Data reader and on-vehicle equipment radio control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a data reader capable of reading data from received signals with a small CPU burden. <P>SOLUTION: This data reader reading data on a pulse signal string from the received signal 9 including the pulse signal string having a plurality of bit cycles Tp, Td as repetition cycles, is provided with a sampling means for sampling specific bit parts (e.g., second bit parts) of the plurality of bit cycles Tp, Td of the received signal 9, and a data reading means for reading the data on the received signal 9 based on the sampling result of the sampling means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a data reader for reading data carried on a pulse signal sequence from a received signal including a pulse signal sequence having a repetition period of a plurality of bit periods, and an in-vehicle device radio control system using the data reader.

  Conventionally, in an in-vehicle device wireless control system that wirelessly controls an in-vehicle device mounted on a predetermined vehicle by a wireless remote control signal from a user's portable remote controller, such as a remote keyless entry system, as the wireless remote control signal, FIG. As shown in FIG. 6, a signal including a pulse signal sequence having a repetition period Td of, for example, a 3-bit period (3TE) is used, and the vehicle side reads the data on the pulse signal sequence from the wireless remote control signal. The in-vehicle device is controlled based on the read data. TE in FIG. 6 is a cycle per bit.

  As a conventional method of reading data from a wireless remote control signal on the vehicle side, a sampling method for each bit has been adopted. That is, for example, as shown by the arrows in FIG. 6, sampling is performed for each bit portion within the repetition period (3-bit period) Td of the received wireless remote control signal to detect the pulse width of the pulse signal within the repetition period. From the detected pulse width, the data placed in the repetition cycle is read (for example, when the pulse width is 2TE, the data is read as “0” of the logic level). Each arrow in FIG. 6 represents sampling.

  In this type of in-vehicle device radio control system, encryption technology (for example, encryption technology KEELOQ of Microchip, etc.) may be applied to the wireless remote control signal. In this case as well, data from the wireless remote control signal on the vehicle side As a reading method, a sampling method for each bit is adopted as described above.

  The above-described in-vehicle device radio control system employs a sampling method for each bit as a method of reading data from a radio remote control signal on the vehicle side, so that there is a drawback in that the processing load on the sampling of the CPU is large. . In particular, if there is an application that operates in parallel with the sampling, there is a drawback in that the processing load on the CPU increases more and the application cannot be operated sufficiently quickly.

  SUMMARY OF THE INVENTION An object of the present invention is to provide, firstly, a data reader capable of reading data from a received signal with a small CPU burden, and secondly, an in-vehicle device radio control system using the data reader. Is to provide.

  In order to solve the above-mentioned problem, the invention according to claim 1 is a data reading device that reads data carried on a pulse signal sequence from a received signal including a pulse signal sequence having a repetition period of a plurality of bit periods. Sampling means for sampling a specific bit portion of the plurality of bit periods of the received signal; and data reading means for reading the data loaded on the received signal based on a sampling result of the sampling means. .

  According to a second aspect of the present invention, in the case where the plurality of bit periods of the received signal include a bit portion in which the amplitude of the received signal changes and a bit portion in which the amplitude of the received signal does not change according to the content of the data, The specific bit portion is a bit portion in which the amplitude of the received signal changes according to the content of the data.

  According to a third aspect of the present invention, when the period per bit is TE and the specific bit part is the Ni-th bit part of the plurality of bit periods, the sampling means is the plurality of bits of the received signal. The start part of the period is detected, and every time the start part of the multi-bit period is detected, the received signal is sampled when (Ni−0.5) × TE time elapses from the detection point. Is.

  According to a fourth aspect of the present invention, there is provided a specific bit portion within the plurality of bit periods of the reception signal from the time when the beginning of the plurality of bit periods of the reception signal is detected until Ni × TE time elapses. 1st judgment means which judges whether sampling of this was performed is further provided.

  According to a fifth aspect of the present invention, in the case where the number of bit periods of the plurality of bit periods is Nf, even if Nf × TE time elapses after the start of the plurality of bit periods of the received signal is detected, When the start portion of the plurality of bit periods is not detected, the received signal is further provided with second determining means for determining that the received signal is an unspecified received signal.

  The invention according to claim 6 is an in-vehicle device radio control system for wirelessly controlling an in-vehicle device mounted on a predetermined vehicle by a radio remote control signal from a user's portable remote controller, wherein the radio remote control signal includes a plurality of radio remote control signals. 2. A pulse signal train having a bit period as a repetition period, wherein the portable remote controller and the vehicle side receive a wireless remote controller signal from the portable remote controller and read data carried on the received signal. A data reader according to any one of claims 5 to 6 and control means for controlling the in-vehicle device based on data read by the data reader.

  According to the first aspect of the present invention, the specific bit portion within a plurality of bit periods of the received signal is sampled, and the data placed on the received signal is read based on the sampling result. Can read data from the received signal with a small CPU load.

  According to the second aspect of the present invention, when the bit portion in which the amplitude of the received signal changes and the bit portion in which the amplitude of the received signal does not change are included in the plurality of bit periods of the received signal, the specific bit portion is Since this is a bit portion in which the amplitude of the received signal changes according to the data content, the data can be accurately read from the received signal even by sampling for each specific bit portion of a plurality of bit periods of the received signal.

  According to the third aspect of the present invention, every time a start portion of a plurality of bit periods of the received signal is detected, when (Ni−0.5) × TE time elapses from the detection time, Thus, sampling can be appropriately performed for each specific bit portion of a plurality of bit periods of the received signal.

  According to the fourth aspect of the present invention, sampling at the specific bit portion of the plurality of bit periods of the received signal until the time Ni × TE has elapsed since the beginning of the plurality of bit periods of the received signal was detected. Since the first determination means for determining whether or not has been performed, it is possible to appropriately detect a sampling failure due to a sampling delay, and to prevent erroneous recognition and reading of data from the received signal.

  According to the fifth aspect of the present invention, when the start portion of the next multi-bit period is not detected even after Nf × TE time has elapsed since the start of the multi-bit period of the received signal is detected, Since the received signal is provided with the second determination means for determining that the received signal is not specified, it is possible to prevent erroneous reading of unrelated data from the received signal that is not specified when the signal that is not specified is received.

  According to invention of Claim 6, the vehicle equipment radio | wireless control system which show | plays the effect in any one of Claims 1-5 can be provided.

  FIG. 1 is a schematic configuration diagram of an in-vehicle device radio control system using a data reader according to the present invention.

  The in-vehicle device wireless control system 1 according to this embodiment wirelessly controls an in-vehicle device mounted on a predetermined vehicle by a wireless remote control signal from a user's portable remote controller (here, for example, a remote keyless entry system). As shown in FIG. 1, a car key 3 with a remote control function as the portable remote controller and a door for locking and unlocking a car door as the in-vehicle device on the vehicle side based on a wireless remote control signal 9 from the key 3 And a control unit 7 for controlling the locking / unlocking device 5. Here, a case where an encryption technology (for example, encryption technology KEELOQ of Microchip) is applied to the wireless remote control signal 9 will be described.

  The key 3 includes a button 3a for receiving a wireless operation for locking and unlocking the automobile door, a transmission unit 3b, predetermined data (encryption key and key side synchronization counter value) used for generating encrypted data, and a key side serial number. Is stored in the storage unit 3c and in response to an operation input to the button 3a, predetermined data (the encrypted data, the button code corresponding to the operation input of the button 3a and the encrypted data) For example, a control unit 3d for transmitting a wireless remote control signal 9 of 300 MHz band carrying the key side serial number).

  When there is an operation input to the button 3a, the control unit 3d uses the predetermined encryption algorithm (for example, the encryption technology KEELOQ of Microchip Corporation) as shown in FIG. 2, and the encryption stored in the storage unit 3c. Encrypted data is generated from the key and the key-side synchronization counter value, and the generated encrypted data, the key-side serial number stored in the storage unit 3c, and the button code corresponding to the operation input of the button 3a are transmitted as a wireless remote control signal. 9 is transmitted from the transmission unit 3b to the control unit 7 side on the vehicle side. Each time such transmission is performed, the control unit 3d increments the key-side synchronization counter value stored in the storage unit 3c by one, and updates and stores the key-side synchronization counter. The encrypted data is generated using a value.

  Here, for example, as shown in FIG. 2, the radio remote control signal 9 includes a preamble part (for example, 24 bits) 9a, a synchronization header part (for example, 10 bits) 9b, and a data part 9c in order (transmission order) from the MSB side. Configured. For example, the data portion 9c is configured by arranging encrypted data (for example, 32 bits), a key-side serial number (for example, 28 bits), and a button code (for example, 4 bits) in order from the MSB side.

  For example, as shown in FIG. 3, the preamble section 9a sets the repetition period Tp to a 2-bit period (2TE), and sets the amplitude of each bit part in the 2-bit period to the H level in order (transmission order) from the MSB side. It consists of a pulse signal sequence in which 12 pulse signals for level are arranged. This preamble section 9a represents information (data) that the radio remote control signal is not noise by listing 12 pulse signals as described above. In the synchronization header portion 9b, for example, as shown in FIG. 3, the L level is repeated for a period of 10 bits (10TE). Further, as shown in FIG. 3, for example, the data portion 9c has a repetition period Td of 3 bit periods (3TE), and the amplitude of each bit portion in the 3 bit period is set to H level, H level, L It consists of a pulse signal sequence in which a predetermined number of pulse signals having a level (in this case, the pulse width is 2 TE) or H level, L level, and L level (in this case, the pulse width is 1 TE). Each pulse signal in the data portion 9b represents, for example, a logical level “0” when the pulse width is 2TE, and represents a logical level “1” when the pulse width is 1TE.

  Here, in the repetition period Tp of the data portion 9c, the bit portion (here, the second bit portion) in which the amplitude of the signal 9 changes according to the data content (“0” or “1”) and the signal 9 Are included in the bit portion (here, the first bit portion and the third bit portion) in which the amplitude of the signal does not change.

  For example, as shown in FIG. 1, the vehicle-side control unit 7 receives a wireless remote control signal 9 from the key 3 and reads the data on the reception signal 9 obtained from the reception unit 7a. A data reading unit (data reading device) 7b for verifying whether the received signal is from the key 3 and predetermined data (decryption key, vehicle side serial number) used for verifying whether the received signal is from the regular key 3 And a storage unit 7c that stores the vehicle-side synchronization counter value) and a control unit that controls the door locking / unlocking device 5 based on the data read by the data reading unit 7b when the received signal is from the regular key 3 ( Control means) 7d. The data reading unit 7b has a function of sampling the received signal from the receiving unit 7a (sampling means), and a data reading function (data reading means) of reading data placed on the received signal based on the sampling result. . Here, the data reading part 7b, the memory | storage part 7c, and the control part 7d are comprised, for example in the microcomputer 7e.

  In addition, the vehicle side serial number memorize | stored in the memory | storage part 7c is the same number as the key side serial number memorize | stored in the memory | storage part 3c by the side of the key 3. FIG. The vehicle-side counter value initially stored in the storage unit 7c is the same value as the key-side synchronization counter value initially stored in the key 3-side storage unit 3c.

  The data reading unit 7b first determines the presence or absence of the preamble unit 9a with respect to the received signal from the receiving unit 7a. That is, the data reading unit 7b performs sampling (detection of the amplitude of the received signal) at the second bit portion (specific bit portion) of each cycle at a 2-bit cycle from the first rising time of the received signal, and the sample result Based on the above, the presence or absence of the preamble portion 9a is determined. More specifically, referring to FIG. 3, every time a rising edge of a pulse signal (starting part of a repetition period Tp which is a 2-bit period) is detected in the order of reception with respect to a received signal, the rising edge of the pulse signal is detected. Then, when 1.5 × TE time has elapsed from the detection time (arrow part), sampling is performed on the received signal, and the rise of the pulse signal is repeated 12 times at intervals of 2 bits (2TE) If the sampling results at the time when 1.5 × TE time has elapsed from each of the 12 detection times are all at the L level, it is determined that the preamble portion 9a is present, otherwise, the preamble portion It is determined that there is no 9a.

  If the data reading unit 7b determines that the preamble unit 9a is not present, the data reading unit 7b invalidates the received signal as not being a remote control signal (for example, noise). On the other hand, if the data reading unit 7b determines that the preamble unit 9a is present, A pulse signal sequence portion following the synchronization header portion (L level portion) 9b following the preamble portion 9a as a signal is regarded as a data portion 9c, and data (encrypted data, key side serial number and button code) is received from the data portion 9c. )

  Here, the data reading unit 7b performs sampling at the second bit portion (specific bit portion) of each cycle in a 3-bit cycle from the first rising time of the data portion 9c, and reads the data from the sample result. go. More specifically, referring to FIG. 3, the rising edge of the pulse signal (starting portion of the repetition period Td, which is a 3-bit period) is detected in the order of reception with respect to the data portion 9c, and the rising edge of the pulse signal is detected. Every time 1.5 × TE time has elapsed from the detection point (arrow part), sampling is performed on the data portion 9c, and if the sampling result is H level, within the repetition cycle Td When the represented data is read as a logical level “0” and the sampling result is an L level, the data represented in the repetition period Td is read as a logical level “1”. In this way, the data reading unit 7b reads data (encrypted data, key-side serial number and button code) from the data unit 9c.

  Then, as shown in FIG. 4, the data reading unit 7 b determines whether the received signal is a valid remote control signal from the regular key 3 using the read encrypted data and the key-side serial number. To do. That is, the data reading unit 7b first compares the read key-side serial number with the vehicle-side serial number stored in the storage unit 7c. It is determined that the received signal is not a signal (that is, a remote control signal from another key with a remote control function) and the received signal is ignored. ) And the decryption key stored in the storage unit 7c, the key-side synchronization counter value is decrypted from the encrypted data read from the received signal.

  If the key reading counter value cannot be decoded from the encrypted data, the data reading unit 7b determines that the received signal is not a valid remote control signal from the regular key 3, and ignores the received signal. On the other hand, when the key-side synchronization counter value is decrypted from the encrypted data, the decrypted key-side synchronization counter value is collated with the vehicle-side synchronization counter value stored in the storage unit 7c. If they match, it is determined that the received signal is a valid remote control signal from the regular key 3, and the vehicle counter value stored in the storage unit 7c is incremented by one and updated and stored. According to the button code read from the received signal, the door locking / unlocking device 5 is locked or unlocked via the control unit 7d. On the other hand, if the key-side synchronization counter value is greater than the vehicle-side synchronization counter value if they do not match, it is determined that the received signal is a valid remote control signal from the key 3 but is not valid, and read from the received signal. Without executing the button code, the key counter value read from the received signal is overwritten and stored as the vehicle counter value in the vehicle counter value in the storage unit 7c, and the overwritten stored vehicle counter value is stored. Increment by one, only update storage is performed, and wait for the normal remote control signal to be transmitted from the key 3 again. On the other hand, if the key-side synchronization counter value is smaller than the vehicle-side synchronization counter value when they do not match, it is determined that the received signal is not a remote control signal from the regular key 3 (ie, an imitation remote control signal by an eavesdropper). The received signal is ignored.

  According to the in-vehicle device radio control system 1 configured as described above, in the data reading unit 7b, the specific bit portion of the received signal having a plurality of bit periods (the second bit portion of the 2-bit period in the preamble portion 9a, the data portion 9c). In this case, sampling is performed every second bit portion of the 3-bit period), and the data loaded on the received signal is read based on the sampling result, so that the data can be read with a smaller number of sampling times than before, and the CPU load is small. Thus, data can be read from the received signal.

  Also, within the 3-bit period Td of the data portion 9c of the received signal, the bit portion (second bit portion) where the amplitude of the received signal changes according to the data content and the bit portion (first bit portion and third bit portion) where it does not change. Portion) is included, the specific bit portion is a bit portion (second bit portion) in which the amplitude of the received signal changes according to the data content, and therefore the specification of the 3-bit period of the data portion 9c of the received signal Even when sampling is performed for each bit portion, the data can be accurately read from the data portion 9c.

  Further, every time the beginning portion of the plurality of bit periods Tp, Td of the received signal is detected, 1.5 × TE time (generally, the specific bit portion is the Nith number in the plurality of bit periods Tp, Td). In the case of the bit portion, sampling is performed on the received signal when (Ni-0.5) × TE time) has elapsed, and accordingly, 2 bits within the multiple bit periods Tp and Td of the received signal Sampling can be performed for each eye part (specific bit part).

  In this embodiment, not only the data portion 9c but also the preamble portion 9a has been described by sampling only a specific bit of the repetition period. However, for the preamble portion 9a, as in the past, for each bit of the repetition period, You may make it sample.

  In this embodiment, the case where the data of the data portion 9c is represented by the so-called PMW code method has been described. However, it is needless to say that the present invention can also be applied when represented by the Manchester code method. That is, the data of the data portion 9c is the Manchester encoding method (the 2-bit period is the repetition period Tm, and the amplitude of each bit part of the 2-bit period is set to the H level and L level in this order from the MSB side (in this case, the logic level “0”)). ) Or L level or H level (in this case, a method using a pulse signal having a logic level “1”), as in the PMW encoding method, a specific bit portion (for example, 2 bits) of the repetition period Tm. When only the (eye portion) is sampled and the sampling result is L level (H level), it may be read as the logic level “0” (“1”) represented in the repetition period Tm.

<Modification 1>
In the above embodiment, the data reading unit 7b further includes 1.5 × TE time (in general, from the time when the rising edge of the pulse signal of the data unit 9c of the received signal (the beginning of the repetition period Td) is detected. When the specific bit part is the Ni-th bit part of the repetition periods Tp and Td, the (N−0.5) × TE time) elapses in the specific bit part within the repetition period Td of the received signal. A determination function (first determination means) for determining whether or not sampling has been performed may be provided, and when it is determined that the sampling has not been performed, for example, the received signal may be discarded as a sampling delay. In this way, it is possible to appropriately detect a sampling failure due to a sampling delay, and it is possible to prevent erroneous recognition and reading of data from the received signal.

<Modification 2>
In the above-described embodiment, the data reading unit 7b further includes 3TE time (generally, the repetition period Td) from the time when the rising edge of the pulse signal of the data part 9c of the received signal (the beginning part of the repetition period Td) is detected. When the number of bit periods is Nf, a determination function (second determination means) that determines that the received signal is an unspecified received signal when the rising edge of the next pulse signal is not detected even after Nf × TE time) If the received signal is determined to be an unspecified received signal, the received signal may be discarded. In this way, when a non-standard signal is received, it is possible to prevent erroneous reading of unrelated data from the non-standard signal.

<Modification 3>
In the above embodiment, as an example of the in-vehicle device radio control system, the remote keyless entry system (the button for operating the in-vehicle device 5 wirelessly on the key side) has been described, but the smart key system (in-vehicle device) 5 may be configured such that a button for wirelessly operating 5 is on the vehicle-side control unit 7 side. That is, the in-vehicle device radio control system (smart key system) 1B in that case, as shown in, for example, FIG. 5, wirelessly connects the in-vehicle device 5 to the vehicle-side control unit 7 side as compared with the above-described embodiment. In addition to a button 7f for operation, a radio signal corresponding to the operation input of the button 7f from the transmission unit 7g to the key 3 side according to the operation input to the transmission unit 7g and the button 7f (for example, a wireless signal of 100 kHz band) Signal) 11 and a transmission control unit 7h that transmits the signal 11 on the other hand, except that the key 3 side further includes a reception unit 3e that receives the radio signal 11 from the control unit 7 on the vehicle side. Is done.

  In this in-vehicle device radio control system 1B, when there is an operation input to the button 7f in the control unit 7 on the vehicle side, the radio corresponding to the operation input of the button 7f from the transmission unit 7g to the key 3 side by the transmission control unit 7h. Signal 11 is transmitted. When the wireless signal 11 from the vehicle-side control unit 7 is received by the receiving unit 3e on the key 3 side, the same processing as in the above embodiment is performed with the reception as a trigger, and the control unit The wireless remote control signal 9 carrying predetermined data (encrypted data, button code corresponding to the operation input of the button 7f and the key 3 side serial number) is transmitted from the transmission unit 3b to the control unit 7 on the vehicle side by 3d. When the control unit 7 on the vehicle side receives the radio signal 11 from the key 3 side by the receiving unit 7a, the same processing as in the above embodiment is performed in the control unit 7, and the in-vehicle device 5 is controlled.

  In this case, the vehicle-mounted device radio control system 1B also obtains the same effects as those in the above-described embodiment.

1 is a schematic configuration diagram of an in-vehicle device radio control system using a data reader according to an embodiment of the present invention. It is a figure explaining the encryption process of the radio | wireless remote control signal by the key side in the vehicle equipment radio | wireless control system of FIG. It is a figure explaining the waveform structure and sampling method of a radio | wireless remote control signal in the vehicle equipment radio | wireless control system of FIG. It is a figure explaining the process of the data reading part by the side of the vehicle in the vehicle equipment radio | wireless control system of FIG. It is a block schematic diagram of the vehicle equipment radio | wireless control system which concerns on the modification 3. It is a figure explaining the waveform structure and sampling method of the radio | wireless remote control signal in the conventional vehicle equipment radio | wireless control system.

Explanation of symbols

1,1B In-vehicle device wireless control system 3 key 3a button 3b transmission unit 3c storage unit 3d control unit 3e reception unit 5 door locking / unlocking device 7 control unit 7a reception unit 7b data reading unit 7c storage unit 7d control unit 7e microcomputer 7f button 7g Transmission unit 7h Transmission control unit 9 Radio remote control signal Td, Tp Repeat period TE Period per bit

Claims (6)

A data reader for reading data placed on the pulse signal sequence from a received signal including a pulse signal sequence having a repetition period of a plurality of bit periods
Sampling means for sampling specific bit portions of the plurality of bit periods of the received signal;
Data reading means for reading the data carried on the received signal based on the sampling result of the sampling means;
A data reading device comprising: In the case where the bit portion where the amplitude of the received signal changes and the bit portion which does not change according to the content of the data are included in the plurality of bit periods of the received signal,
The data reading apparatus according to claim 1, wherein the specific bit portion is a bit portion in which an amplitude of the reception signal changes according to a content of the data. When the period per bit is TE, and the specific bit part is the Ni-th bit part of the plurality of bit periods,
The sampling means detects the start portion of the plurality of bit periods of the received signal, and every time the start portion of the plurality of bit periods is detected, (Ni−0.5) × TE time has elapsed from the detection time point. The data reading apparatus according to claim 1, wherein sampling is performed on the received signal at a point in time.   Whether or not sampling at the specific bit portion in the plurality of bit periods of the reception signal has been performed until Ni × TE time has elapsed since the beginning of the plurality of bit periods of the reception signal was detected. The data reading apparatus according to claim 3, further comprising a first determination unit for determining. When the number of bit periods of the plurality of bit periods is Nf,
If the beginning of the next plurality of bit periods is not detected even after Nf × TE time has elapsed since the beginning of the plurality of bit periods of the received signal is detected, the received signal is an unspecified reception signal. 5. The data reading apparatus according to claim 3, further comprising a second determination unit for determining. An in-vehicle device wireless control system that wirelessly controls an in-vehicle device mounted on a predetermined vehicle by a wireless remote control signal from a user's portable remote controller,
The wireless remote control signal includes a pulse signal sequence having a repetition period of a plurality of bit periods,
The data reader according to any one of claims 1 to 5, wherein the portable remote controller and the vehicle side receive a wireless remote controller signal from the portable remote controller and read data carried on the received signal. And a control means for controlling the in-vehicle device based on the data read by the data reading device.

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