JP2011073568A - On-vehicle machine - Google Patents

Abstract

An object of the present invention is to provide an in-vehicle device mainly used for locking / unlocking, opening / closing, etc. of a door of an automobile, with an accurate determination of a site where an abnormality has occurred and easy maintenance.
A transmission antenna 45 is connected to a control means 43 of an in-vehicle device 50, an inspection signal A1 generated by the control means 43 is transmitted via the transmission antenna 45, and a feedback signal C1 that is a harmonic of the inspection signal A1 is obtained. Since feedback to the control means 43 is received via the reception circuit 42, and the control means 43 determines the abnormality of the reception circuit 42 based on the feedback signal C1, the determination of the part where the abnormality has occurred is accurate and easy maintenance is possible. An in-vehicle device can be obtained.
[Selection] Figure 1

Description

  The present invention relates to an in-vehicle device that is used in a vehicle communication system that is mainly mounted on an automobile and used for remote control such as locking / unlocking and opening / closing of a door.

  In recent years, a driver can bring a portable device closer to the vehicle and operate a switch disposed on the vehicle door, etc. to unlock the vehicle door and lock the vehicle door only by leaving the vehicle. Vehicle communication systems capable of passive keyless entry are gradually spreading.

  Such a conventional vehicle communication system will be described with reference to FIG.

  FIG. 5 is a circuit block diagram of a conventional vehicle communication system, in which 1 is a receiving antenna having a resonance frequency in an ultra high frequency band (hereinafter referred to as UHF band) of 350 MHz, for example. Reference numeral 2 denotes a receiving circuit composed of electronic components connected to the receiving antenna 1, and 3 denotes, for example, a 125 kHz low frequency band (hereinafter referred to as LF band) composed of electronic components. The LF circuit for transmission is connected to the external terminals 4 and 5.

  Further, reference numeral 6 denotes a control means composed of a microcomputer or the like, and the control means 6 is electrically connected to the receiving circuit 2, the LF circuit 3 and the external terminal 7 to constitute the in-vehicle device 10.

  Such an in-vehicle device 10 is arranged at a predetermined position such as inside the instrument panel in front of the driver's seat, and the external terminals 4 and 5 of the in-vehicle device 10 are, for example, an in-vehicle antenna of LF band of 125 kHz indicated by 11. Are electrically connected via a connector or a harness.

  Further, the external terminal 7 of the in-vehicle device 10 is electrically connected to a driving device (not shown) such as a motor that performs a locking operation and an unlocking operation of a door locking / unlocking switch.

  On the other hand, 21 is a transmission antenna having a resonance frequency in the UHF band of 350 MHz, for example, 22 is a transmission circuit composed of electronic components connected to the transmission antenna 21, and 23 is a reception antenna having a resonance frequency in the LF band of 125 kHz, for example. Thus, the transmission antenna 21 is connected to the transmission circuit 22.

  Further, reference numeral 24 denotes a control means composed of a semiconductor element such as a microcomputer, which is supplied with power from a battery 25 such as a cylindrical lithium battery, and connected to the transmission circuit 22 and the reception antenna 23. Was composed.

  The vehicle-mounted device 10, the vehicle-mounted antenna 11, and the portable device 30 constitute a conventional vehicle communication system.

  In the above configuration, in the conventional vehicle communication system, as a so-called passive keyless entry operation, first, the control means 6 of the in-vehicle device 10 operates a button-like switch (not shown) provided on, for example, a vehicle door. After the operator performs a pressing operation, a request signal 12 for inquiring about the presence / absence of the portable device is transmitted via the in-vehicle antenna 11.

  When the driver who owns the portable device 30 approaches the vicinity of the vehicle, the control means 24 to which the request signal 12 is input via the receiving antenna 23 of the portable device 30 indicates that the request signal 12 is a normal signal. After confirming that it exists, the unlock signal 13 is automatically output.

  And the control means 6 of the vehicle equipment 10 which received the unlocking signal 13 drives the drive device, such as a motor, after confirming that the unlocking signal 13 is a regular signal, for example, unlocks the front door. .

  At this time, if any of the in-vehicle device 10, the in-vehicle antenna 11, and the portable device 30 is abnormal, the front door lock is not released, but the in-vehicle antenna 11 or the LF circuit of the in-vehicle device 10. 3, that is, in a situation where the request signal 12 is not transmitted, it is possible to specify that there is a cause of the abnormality in the in-vehicle device 10 or the in-vehicle antenna 11 mounted on the vehicle, not the portable device 30. it can.

  That is, the control means 6 of the in-vehicle device 10 monitors the current between the external terminals 4 and 5 that flows when the request signal 12 is transmitted. If the current is not within a predetermined range, the in-vehicle device 10 or the in-vehicle antenna 11 is monitored. It is determined that an abnormality has occurred.

  However, if an abnormality has occurred in the transmission circuit 22 of the portable device 30 or the reception circuit 2 of the in-vehicle device 10, the unlocking signal 13 cannot be received by the control means 6 of the in-vehicle device 10 in any case. It could not be determined whether the machine 30 or the vehicle-mounted machine 10 has a cause of failure.

  As prior art document information related to the invention of this application, for example, Patent Document 1 is known.

JP-A-9-78913

  As described above, in the vehicle-mounted device used in the conventional vehicle communication system, when any abnormality occurs in either the transmission circuit 22 of the portable device 30 or the reception circuit 2 of the vehicle-mounted device 10, in any case Since the unlocking signal 13 cannot be received by the control means 6 of the in-vehicle device 10, there is a problem that it is impossible to determine which of the in-vehicle device 10 or the portable device 30 is abnormal.

  The present invention solves such a conventional problem, and by detecting a failure of the receiving circuit of the in-vehicle device, it is possible to determine whether the abnormality is in the in-vehicle device 10 or the portable device 30, It is an object of the present invention to provide an in-vehicle apparatus that can accurately determine a site where an abnormality has occurred and is easy to maintain.

  In order to achieve the above object, the present invention has the following configuration.

  According to the first aspect of the present invention, the transmission antenna is connected to the control unit of the vehicle-mounted device, the inspection signal generated by the control unit is transmitted via the transmission antenna, and the feedback signal that is a harmonic of the inspection signal is generated. It is fed back to the control means via the receiving circuit, and by determining the abnormality of the receiving circuit based on the feedback signal by the control means, it can be determined whether the abnormality is in the in-vehicle device 10 or the portable device 30. It has the effect of providing an in-vehicle device that is accurate in determining the part that is generated and easy to maintain.

  The invention according to claim 2 can be formed simultaneously with the formation of the wiring pattern of the receiving circuit of the in-vehicle device by configuring the transmitting antenna of the in-vehicle device with the wiring pattern wired on the printed circuit board. There is an effect that it is possible to provide an in-vehicle apparatus that can accurately determine a site where an abnormality has occurred at low cost and that is easy to maintain without requiring separate processing.

  According to the third aspect of the present invention, the fundamental frequency is not transmitted from the transmission antenna by setting the resonance frequency of the transmission antenna of the vehicle-mounted device to 1/5 or more and 5 times or less of the resonance frequency of the reception antenna. It has the effect of providing an in-vehicle device that can suppress radiation noise to the control means and the receiving circuit inside the in-vehicle device.

  As described above, according to the present invention, it is possible to obtain an advantageous effect that it is possible to realize an in-vehicle device that can accurately determine a site where an abnormality has occurred and can be easily maintained.

1 is a circuit block diagram of a vehicle communication system according to an embodiment of the present invention. Signal waveform diagram explaining harmonics 1 is a signal waveform diagram of a vehicle communication system according to an embodiment of the present invention. Partial circuit diagram Circuit block diagram of conventional vehicle communication system

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  In addition, the same code | symbol is attached | subjected to the part of the structure same as the structure demonstrated in the term of background art, and detailed description is simplified.

(Embodiment)
FIG. 1 is a circuit block diagram of a vehicle communication system according to an embodiment of the present invention. In FIG. 1, reference numeral 41 is a receiving antenna having a resonance frequency in the UHF band of 350 MHz, for example, and is a metal bent in an L shape, for example. A wire conductor is formed by, for example, soldering a conductive wire vertically on a printed board.

  Reference numeral 42 denotes a receiving circuit composed of electronic components for amplifying and detecting a signal input from the receiving antenna 41.

  Further, 43 is a control means composed of a microcomputer or the like, which is connected to the receiving circuit 42 directly or indirectly via a predetermined circuit and to the external terminal 44.

  Reference numeral 45 denotes a transmission antenna connected to the signal output terminal 43A of the control means 43. The transmission antenna 45 is formed as a wiring pattern on the printed circuit board. For example, a photoresist is applied to the upper surface or the lower surface of the circuit board to form a predetermined pattern. It is created by performing photolithography that exposes the light.

  The transmission antenna 45 is formed so that the resonance frequency is, for example, 1/5 times or more and 5 times or less of the resonance frequency of the reception antenna 41, and one end of the reception antenna 41 is connected to the signal output terminal 43A. The other end (not shown) is connected to an open end or a connector terminal (not shown) connected to the substrate.

  Reference numeral 47 denotes an LF circuit configured by electronic components that transmits radio waves in the LF band, and is connected to the external terminals 48 and 49 and to the control means 43.

  The vehicle-mounted device 50 includes the reception antenna 41, the reception circuit 42, the control unit 43, the transmission antenna 45, and the LF circuit 47.

  The in-vehicle device 50 is arranged at a predetermined position such as the inside of the instrument panel in front of the driver's seat, and the external terminals 48 and 49 of the in-vehicle device 50 are, for example, a 125 kHz LF in-vehicle antenna and a connector It is electrically connected via a harness.

  The external terminal 44 of the in-vehicle device 50 is electrically connected to a driving device (not shown) such as a motor that performs a locking operation and an unlocking operation of a door locking / unlocking switch.

  On the other hand, 21 is a transmission antenna having a resonance frequency in the UHF band of 350 MHz, for example, 22 is a transmission circuit composed of electronic components connected to the transmission antenna 21, and 23 is a reception antenna having a resonance frequency in the LF band of 125 kHz, for example. It is.

  Further, reference numeral 24 denotes a control means constituted by a semiconductor element such as a microcomputer, which is supplied with power from a battery 25 such as a cylindrical lithium battery, and is connected to the transmission circuit 22 and the reception antenna 23 to constitute the portable device 30. Has been.

  And the vehicle communication system 60 is comprised from the vehicle equipment 50, the vehicle-mounted antenna 11, and the portable device 30. FIG.

  In the vehicle communication system 60 configured as described above, as a so-called passive keyless entry operation, first, the control means 43 of the in-vehicle device 50 is provided with a request signal 12 for inquiring the presence / absence of a portable device, for example, on the door of the vehicle. After detecting a signal that a driver presses a button-like switch (not shown), the signal is transmitted via the vehicle-mounted antenna 11.

  When the driver who owns the portable device 30 approaches the vicinity of the vehicle, the control means 24 to which the request signal 12 is input via the receiving antenna 23 of the portable device 30 indicates that the request signal 12 is a normal signal. After confirming that it exists, the unlock signal 13 is automatically output via the transmission circuit 22 and the transmission antenna 21.

  The control means 43 of the in-vehicle device 50 that has received the unlock signal 13 confirms that the unlock signal 13 is a legitimate signal, and then drives a driving device such as a motor via the external terminal 44, for example, the front Unlock the door.

  If any of the in-vehicle device 50, the in-vehicle antenna 11 and the portable device 30 has an abnormality, the front door is not unlocked but the request signal 12 is not transmitted. It is possible to specify that there is a cause of abnormality in the in-vehicle device 50 or the in-vehicle antenna 11 mounted on the vehicle.

  In this case, the current flowing between the external terminals 48 and 49 when the request signal 12 is transmitted is monitored by the control means 43 of the in-vehicle device 50, and if the current is not within the predetermined range, it is determined that there is a failure. is there.

  On the other hand, when the unlocking signal 13 cannot be received by the control unit 43 of the in-vehicle device 50, the control unit 43, for example, after the driver presses a button-like switch (not shown) provided on the vehicle door or the like. The inspection signal A1 is output from the signal output terminal 43A.

  Here, in the signal waveform diagram of FIG. 2, the inspection signal A1 is a square wave as shown in FIG. 2A, for example, and is generated based on a clock signal for operating the control means 43, for example, a period of 1 MHz. Signal.

  Such a square wave signal is composed of a set of signals having a plurality of sine wave waveforms having different amplitudes.

  This will be described with reference to FIG. 2B. In FIG. 2B, the waveform is approximated to the square wave inspection signal A1 in FIG. 2A by increasing the number of combined waveforms. It shows how it works.

  Here, the signal A2 indicated by the alternate long and short dash line is a signal having the same cycle as the inspection signal A1 in FIG. 2A, and this is called a fundamental wave.

  On the other hand, the signal A3 indicated by a dotted line is a combination of the signal A2 and a signal whose amplitude is 1/3 times the amplitude of the fundamental wave, and the signal A4 indicated by a solid line is the signal A3 having a frequency five times that of the fundamental wave. And a signal waveform having an amplitude of 1/5 times, and gradually approaches the same square wave signal waveform as the inspection signal A1.

  A signal having a frequency that is an integral multiple of these fundamental waves is a harmonic, and a signal waveform of a square wave is composed of a harmonic having a frequency that is an odd multiple of the fundamental wave and the fundamental wave.

  That is, in FIG. 1, when the control means 43 transmits the inspection signal A1 composed of a square wave having a period of 1 MHz, for example, the transmission signal B1 of a harmonic of 315 MHz included in the inspection signal A1 is transmitted via the transmission antenna 45. .

  This transmission signal B1 is fed back as a feedback signal C1 via the reception antenna 41, amplified and detected by the reception circuit 42, and then input to the control means 43 as a demodulated signal D1.

  Further, with reference to the signal waveform diagram of FIG. 3, FIG. 3 (a) shows the inspection signal A1, for example, a signal in which a 1 MHz signal is repeatedly output for a predetermined time T1 and non-output for a predetermined time T2. It has become.

  FIG. 3B shows the transmission signal B1, and if the resonance frequency of the transmission antenna 45 is, for example, 315 MHz, which is the same as that of the reception antenna 41, during the time T1 when the 1 MHz signal is output as the inspection signal A1. A signal having a frequency of 315 MHz is output, and no transmission is performed during the time T2 when the 1 MHz signal is not output.

  Also, FIG. 3C shows a feedback signal C1, which is a signal that the transmission signal B1 has propagated while being attenuated in the housing of the in-vehicle device 50, and a time T1 during which a 315 MHz signal is transmitted as the transmission signal B1. During this time, the feedback signal C1 also receives a 315 MHz signal with a very small amplitude, and does not receive the 315 MHz signal during the non-transmission time T2.

  Further, FIG. 3 (d) shows a demodulated signal D1, and the feedback signal C1 is amplified by the receiving circuit 42, further detected and demodulated into a Hi / Lo digital signal. As a feedback signal C1, During the time T1 when the 315 MHz signal is received, it becomes a Hi signal, and during the non-reception time T2, it becomes a Lo signal.

  Then, the control means 43 determines whether the demodulated signal D1 is a regular signal. If the demodulated signal D1 can be confirmed as a regular signal, “no abnormality in the reception circuit 42”, and if it is not a regular signal, “the reception circuit 42 is abnormal”. judge.

  That is, if the demodulated signal D1 in FIG. 3D is a repetition of a signal in which the Hi signal is time T1 and the Lo signal is time T2, the signal based on the inspection signal A1 is fed back and the receiving circuit 42 The control means 43 determines that the receiver is operating normally and determines that there is no abnormality in the receiving circuit 42. Even if the demodulated signal D1 cannot be recognized or recognized, the Hi signal is time T1, and the Lo signal is time. If there is no repetition of the signal at T2, “the reception circuit 42 is abnormal”.

  The control means 43 can also be configured to receive the feedback signal C1 amplified by the receiving circuit 42. In this case, when the intensity of the amplified feedback signal C1 exceeds a predetermined threshold value. May be determined as “no abnormality in the reception circuit 42”, or “abnormality in the reception circuit 42” when a predetermined threshold value is not exceeded.

  After the determination by the control means 43 as described above, for example, when it is determined that “the reception circuit 42 is abnormal”, a hazard lamp (not shown) or a buzzer (not shown) connected to the in-vehicle device 50. For example, when the control means 43 determines that there is no abnormality in the receiving circuit 42, the notification means is activated. The control means 43 performs notification control that is not notified to the driver.

  Conversely, when the control means 43 determines that “the reception circuit 42 is normal,” the notification means is activated, and when it is determined that “the reception circuit 42 is abnormal”, the notification control is performed so that the notification means is not activated. The control means 43 may perform it.

  That is, since the driver can know that an abnormality has occurred in the receiving circuit 42 of the in-vehicle device 50, even if the unlocking signal 13 cannot be received by the control means 43 of the in-vehicle device 50, an abnormality has occurred in the in-vehicle device 50. It can be determined that there is a cause.

  Therefore, if an abnormality occurs only in the portable device 30, the driver can mail the portable device 30 for repair, and stop by a vehicle dealer when walking around the city to repair the malfunction. Etc., and the labor of the driver and the inspection at the vehicle dealer can be reduced.

  Accordingly, since it is possible to determine which of the in-vehicle device 50 and the portable device 30 is abnormal, it is possible to provide an in-vehicle device that can accurately determine the site where the abnormality has occurred and can be easily maintained. It becomes possible.

  The remaining power of the inspection signal A1 in FIG. 3A excluding the portion transmitted as the transmission signal B1 in FIG. 3B is the tip of the transmission antenna 45 when the transmission antenna 45 is directly connected to the control means 43. Is reflected as a reflected wave and returns to the signal output terminal 43A of the control means 43.

  When the transmission antenna 45 is directly connected to the control means 43 in this way, it is necessary to reduce the reflected wave by reducing the output of the inspection signal A1 in consideration of the power durability of the signal output terminal 43A. As shown in the circuit diagram, if a high-pass filter circuit 63 composed of, for example, a capacitor 61 and a resistor 62 is disposed between the signal output terminal 43A of the control means 43 and the transmitting antenna 45, the output of the inspection signal A1 can be increased. .

  That is, since most of the reflected wave components of the inspection signal A1 are components having a low frequency near the fundamental wave, the high-pass filter circuit 63 allows most of the reflected wave components to escape to the ground of the printed circuit board. The output of the inspection signal A1 can be increased without consideration.

  As described above, according to the present embodiment, the transmission antenna 45 is connected to the control means 43 of the in-vehicle device 50, the inspection signal A1 generated by the control means 43 is transmitted via the transmission antenna, and the harmonics of the inspection signal A1. The feedback signal C1 is fed back to the control means 43 via the receiving circuit 42, and the control means 43 determines an abnormality of the receiving circuit 42 based on the feedback signal C1, and an abnormality occurs in the receiving circuit 42 of the in-vehicle device 50. By detecting this, it is possible to determine whether the abnormality is in the in-vehicle device 50 or the portable device 30, and to obtain an in-vehicle device in which the determination of the part where the abnormality occurs is accurate and easy to maintain. It can be done.

  Further, by configuring the transmission antenna 45 of the in-vehicle device 50 with a wiring pattern wired on the printed circuit board, it can be formed at the same time as the formation of the wiring pattern of the receiving circuit 42 of the in-vehicle device 50. Therefore, it is possible to obtain an in-vehicle apparatus that can accurately determine a site where an abnormality has occurred at low cost and can be easily maintained.

  Furthermore, since the resonance frequency of the transmission antenna 45 of the in-vehicle device 50 is set to 1/5 or more and 5 times or less of the resonance frequency of the reception antenna 41, for example, the fundamental wave of the frequency of the clock signal of the control means 43 is transmitted. Since it is not transmitted from the antenna 45, it is possible to prevent radiation noise of the fundamental frequency from entering the control means 43 and the receiving circuit 42, and an in-vehicle device that can operate stably can be obtained.

  In the above description, the vehicle communication system 60 that performs the passive keyless entry operation in which the in-vehicle device 50 transmits the request signal 12 to the portable device 30 and the portable device 30 returns the unlocking signal 13 is described. The invention is not limited to this, and the vehicle communication system that performs a keyless entry operation in which the driver simply operates a switch or the like provided in the portable device 30 and the portable device 30 transmits the unlock signal 13 to the in-vehicle device 50. That is, you may use for the vehicle communication system which is not equipped with the vehicle-mounted antenna 11 and the LF circuit 47. FIG.

  The present invention is not limited to the case where the control means 43 outputs the inspection signal A1 when the control means 43 outputs the inspection signal A1 when the switch provided on the door of the vehicle is operated. The control means 43 may be configured to output the inspection signal A1 every predetermined time such as 12 hours.

  The vehicle-mounted device according to the present invention is capable of accurately determining a site where an abnormality has occurred and easy to maintain, and is useful mainly for locking / unlocking and opening / closing control of an automobile door.

DESCRIPTION OF SYMBOLS 11 In-vehicle antenna 12 Request signal 13 Unlock signal 21 Transmitting antenna 22 Transmission circuit 23 Reception antenna 24 Control means 25 Battery 30 Portable device 41 Reception antenna 42 Reception circuit 43 Control means 44, 48, 49 External terminal 47 LF circuit 50 In-vehicle device 60 Vehicle communication system

Claims (3)

A receiving means comprising a receiving antenna and a receiving circuit; a control means for inputting a signal from the receiving means; and a transmitting antenna electrically connected to the control means, wherein the inspection signal generated by the control means A vehicle-mounted feedback signal that is transmitted through a transmission antenna and that is a harmonic of the inspection signal is fed back to the control unit through the reception circuit, and the control unit determines abnormality of the reception circuit based on the feedback signal. Machine. The in-vehicle device according to claim 1, wherein the transmission antenna is configured by a wiring pattern wired on a printed circuit board. The in-vehicle device according to claim 1, wherein the resonance frequency of the transmission antenna is set to 1/5 or more and 5 or less times the resonance frequency of the reception antenna.

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