JP2014195193A - On-vehicle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-vehicle device capable of automatically setting the presence/absence of power feeding according to the types of combined antennas and preventing erroneous setting.SOLUTION: An on-vehicle device 50 performs power feeding when an on-vehicle antenna device 10 includes an antenna booster amplifier 14. The on-vehicle device 50 includes an antenna power feeding circuit 56 that performs power feeding to the antenna booster amplifier 14; a signal power detection section 84 that detects electric power of a signal output from the antenna device 10; a power feeding indication section 82 that indicates power feeding to the antenna power feeding circuit 56; and an antenna determination section 86 that determines types of antennas on the basis of the signal power detected by the signal power detection section 84 when temporary power feeding is performed according to the indication by the power feeding indication section 82.

Description

  The present invention relates to an in-vehicle device that supplies power to an amplifier in an antenna device.

  2. Description of the Related Art Conventionally, a GPS receiver is known in which power is supplied to an amplifier that amplifies a signal received by an antenna through a signal line used to input the output signal of the amplifier to a subsequent circuit (for example, patents). Reference 1). In this GPS receiver, the multipath tolerance is optimized regardless of the type of antenna by changing the threshold for selecting the signal used for positioning calculation depending on whether the antenna is an active antenna or a passive antenna. It becomes possible to control to.

JP 2002-122651 A

  By the way, in an in-vehicle device such as a GPS device disclosed in Patent Document 1, an appropriate threshold value is set regardless of which of an active antenna and a passive antenna is connected. It needs to work properly. Generally, the on / off setting of the power feeding operation is performed based on a user operation while a setting screen is displayed. That is, when an active antenna is connected, the user needs to perform a predetermined operation while looking at the operation screen to enable power supply by the power supply circuit to the amplifier of the active antenna. On the other hand, when the passive antenna is connected, the user needs to perform a predetermined operation while looking at the operation screen to invalidate the power feeding by the power feeding circuit for the passive antenna.

  Thus, in the conventional vehicle-mounted device, there is a problem that it is necessary for the user to set whether or not to supply power according to the type of antenna to be combined, which takes time and effort. In addition, there is a problem that an erroneous setting may occur when the presence / absence of power supply is set according to the user's operation. For example, if power feeding is disabled despite the use of an active antenna, it is not desirable because it may be possible to provide the user with the reception function inherent to the in-vehicle device due to a decrease in reception performance.

  The present invention has been created in view of the above points, and an object of the present invention is to make it possible to automatically set the presence or absence of power feeding according to the type of antenna to be combined, and to prevent erroneous setting. To provide an apparatus.

  In order to solve the above-described problem, the vehicle-mounted device of the present invention includes a power feeding circuit that feeds power to the antenna amplifier in the vehicle-mounted device that feeds power when the antenna device included in the vehicle includes the antenna amplifier; Detection means for detecting the level of the signal output from the antenna device, power supply instruction means for instructing the power supply circuit to supply power to the antenna amplifier, and temporary power supply was performed in response to an instruction from the power supply instruction means Antenna determination means for determining the type of antenna based on the signal level detected by the detection means. Specifically, the type of antenna described above is either an active antenna that includes an antenna amplifier or a passive antenna that does not include an antenna amplifier, and the power supply instruction unit is an active antenna. When the antenna determining means determines that the power feeding operation by the power feeding circuit is enabled, and when the antenna determining means determines that the antenna type is a passive antenna, the power feeding operation by the power feeding circuit is disabled. Yes.

  By temporarily supplying power to the antenna device by the power supply circuit and automatically determining the type of antenna based on the signal level at that time, it is possible to automatically set the presence or absence of power supply according to the type of antenna to be combined it can. Moreover, since the user does not need to set the type of antenna, erroneous setting can be prevented.

  In addition, it is desirable that the temporary power supply performed to determine the type of antenna described above is performed for a predetermined time. By setting the temporary power supply for determining the antenna type for a predetermined time, the influence on the original receiving operation of the in-vehicle device can be reduced.

  In addition, it is desirable that the detection unit described above detects the power of the signal, and the antenna determination unit determines the type of antenna based on a change in signal power corresponding to the presence or absence of temporary power feeding. Based on the change in the signal power, it is possible to accurately identify whether or not the antenna amplifier is operating, that is, whether or not the antenna device is included in the antenna device.

  Further, it is desirable that the antenna type determination by the antenna determination unit described above is performed in accordance with an instruction from the user. This makes it possible to automatically set the presence or absence of power supply according to the type of antenna when an in-vehicle device is mounted on a vehicle or at an arbitrary timing.

  Moreover, it is desirable that the antenna type determination by the antenna determination unit described above is performed when the on-vehicle apparatus is activated. Alternatively, the antenna type determination by the antenna determination unit described above is preferably performed at the timing when the vehicle key switch is turned on. By determining the type of antenna every time the in-vehicle device is activated or started to travel, it is possible to automatically set whether or not to supply power even when the type of antenna to be combined is changed.

1 is a diagram illustrating an overall configuration of an in-vehicle system according to an embodiment. It is a flowchart which shows the operation | movement procedure which determines the kind of antenna apparatus and sets the presence or absence of electric power feeding. It is a figure which shows the mode of the change of the signal power accompanying antenna electric power feeding.

  Hereinafter, an in-vehicle system according to an embodiment to which an in-vehicle device of the present invention is applied will be described with reference to the drawings. FIG. 1 is a diagram illustrating an overall configuration of an in-vehicle system according to an embodiment. The in-vehicle system shown in FIG. 1 includes an antenna device 10 (10A or 10B) whose specifications are determined for each vehicle type, and an in-vehicle device 50 connected to the antenna device 10 via an antenna cable 40. . The output terminal 20 of the antenna device 10 and the input terminal 30 of the in-vehicle device 50 are connected via an antenna cable 40.

  As the antenna device 10, one of two types of antenna devices 10 </ b> A and 10 </ b> B classified according to the presence or absence of power feeding is used. One antenna device 10 </ b> A is a passive antenna and includes an antenna 12. The antenna 12 is directly connected to the output terminal 20. The other antenna device 10B is an active antenna and includes an antenna 12 and an antenna booster amplifier 14. The end of the antenna 12 is connected to the antenna booster amplifier 14. The antenna booster amplifier 14 amplifies and outputs a weak signal received by the antenna 12. The antenna booster amplifier 14 operates by phantom power feeding and performs an amplification operation by an operating voltage supplied from the in-vehicle device 50 via the antenna cable 40.

  The in-vehicle device 50 is a DAB (Digital Audio Broadcasting) receiver, and includes a capacitor 52, a coil 54, an antenna feeding circuit 56, a tuner unit 60, an analog-digital converter (A / D) 62, and an FE (front end) unit. 64, a BE (back end) unit 66, an output processing unit 68, an amplifier 70, a speaker 72, a main control unit 80, a display device 90, and an operation unit 92. The in-vehicle device 50 receives a digital broadcast signal broadcast by a multicarrier method using OFDM (Orthogonal Frequency Division Multiplexing) as a modulation method, performs demodulation processing and decoding processing, and reproduces audio data.

  The capacitor 52 is a coupling capacitor for removing direct current, and extracts a high frequency component signal (RF signal) from a signal (received signal) input via the antenna cable 40. The coil 54 is a band elimination filter that blocks passage of a specific band corresponding to a signal component to be received, and is connected to the input terminal 30. The antenna power supply circuit 56 is connected to the input terminal 30 via the coil 54, generates a predetermined voltage, and supplies power to the antenna booster amplifier 14 in the antenna device 10 via the antenna cable 40.

  The tuner unit 60 is a high frequency circuit and converts a broadcast signal received by the antenna device 10 into an intermediate frequency signal. The analog-digital converter 62 converts the analog intermediate frequency signal output from the tuner unit 60 into digital data (intermediate frequency data). Note that the analog-digital converter 62 may be included in the pre-stage tuner unit 60 or the post-stage FE unit 64.

  The FE unit 64 performs demodulation processing and decoding processing on the intermediate frequency data, and outputs compressed audio data for each service, compressed audio data of various announcements inserted separately from the service, and the like. For example, compressed audio data in MP2 (MPEG1 Audio Layer 2 and MPEG2 Audio Layer 2) format is output as compressed audio data.

The BE unit 66 receives the compressed audio data (MP2 data) output from the FE unit 64, switches the output target service or announcement, expands the compressed audio data such as the switched service, and the like. I do. By the expansion processing, for example, audio data in the I ² S (The Inter-IC Sound Bus) format is output. The output processing unit 68 receives the audio data output from the BE unit 66, converts it into an analog audio signal, and performs variable control of volume, overlay processing of other sounds (for example, operation sounds), and the like. . The amplifier 70 amplifies the audio signal output from the output processing unit 68 and outputs the amplified audio from the speaker 72.

  The main control unit 80 controls the reception operation of the entire vehicle-mounted device 50, determines the type of the connected antenna device 10 (passive antenna / active antenna), and performs the operation of setting the presence / absence of power feeding. For this purpose, the main control unit 80 includes a power supply instruction unit 82, a signal power detection unit 84, and an antenna determination unit 86.

  The power supply instruction unit 82 instructs the antenna power supply circuit 56 to supply power to the antenna booster amplifier 14. The signal power detection unit 84 detects the level (specifically, power) of the signal output from the antenna device 10. Specifically, the signal power detection unit 84 detects (calculates) the signal power using the intermediate frequency data output from the analog-digital converter 62. The antenna determination unit 86 determines the type of the antenna device 10 based on the signal power detected by the signal power detection unit 84 when temporary power supply is performed by the antenna power supply circuit 56 in accordance with an instruction from the power supply instruction unit 82. Determine.

  The display device 90 displays an operation screen indicating an operation state of the in-vehicle device 50, an operation screen for performing various operations, and the like. The operation unit 92 is for a user to give an operation instruction, and includes various operation keys and operation knobs. An instruction to change the volume by the user, an instruction to change the service to be received or an announcement type, and the like are performed using the operation unit 52.

  The signal power detection unit 84 described above corresponds to the detection unit, the power supply instruction unit 82 corresponds to the power supply instruction unit, the antenna determination unit 86 corresponds to the antenna determination unit, and the antenna booster amplifier 14 corresponds to the antenna amplifier.

  The in-vehicle system of the present embodiment has such a configuration, and the operation will be described next. FIG. 2 is a flowchart showing an operation procedure for determining the type of the antenna device 10 and setting the presence / absence of power feeding. The power supply instructing unit 82 determines whether or not it is time to set the presence or absence of power supply (step 100). If it is not the set time, a negative determination is made and this determination is repeated. For example, the timing for setting whether or not to supply power is as follows: (1) when a setting instruction is issued by the user; (2) every time the in-vehicle device 50 is activated; and (3) when the vehicle key switch is turned on. , Etc. can be considered. In addition to the case where any one of (1) to (3) is set as the set timing, two or more may be combined.

  In the case of setting timing, an affirmative determination is made in the determination of step 100. Next, the power supply instruction unit 82 sends an instruction to start power supply to the antenna power supply circuit 56. Thereby, the power supply by the antenna power supply circuit 56 is started (step 102). In parallel with this power feeding operation, the signal power detector 84 takes in the output (intermediate frequency data) of the analog-digital converter 62 and detects (calculates) the signal power (step 104).

  In addition, the power supply instruction unit 82 determines whether or not a predetermined time has elapsed (step 106). This predetermined time needs to be a time in which a change in signal power after the start of power supply can be detected, and is set to, for example, about several hundred ms. If the predetermined time has not elapsed, a negative determination is made in the determination of step 106, and the process returns to step 104 to continue the signal power detection operation.

  Further, when the predetermined time has elapsed, an affirmative determination is made in the determination of step 106. Next, the power supply instruction unit 82 sends an instruction to stop power supply to the antenna power supply circuit 56. Thereby, the power supply by the antenna power supply circuit 56 is stopped (step 108). Further, the antenna determination unit 86 determines whether or not the signal power has increased from the start of the antenna power supply in step 102 to the time when the antenna power supply is stopped in step 108 (step 110). When the signal power increases (when the antenna booster amplifier 14 in the antenna device 10B operates and the received signal is amplified by feeding), an affirmative determination is made, and the antenna determination unit 86 determines that the antenna device 10 is an active antenna. (Step 112). In this case, the power supply instruction unit 82 sends an instruction for enabling the power supply operation to the antenna power supply circuit 56, and the power supply operation by the antenna power supply circuit 56 is started (step 114). On the other hand, when the signal power does not increase (when the antenna booster amplifier 14 is not included in the antenna device 10A and the received signal is not amplified by feeding), a negative determination is made in the determination of step 110, and the antenna determination unit 86 The antenna device 10 is determined to be a passive antenna (step 116). In this case, the power feeding operation by the antenna power feeding circuit 56 is invalid, and the power feeding instruction unit 82 does not give a power feeding instruction to the antenna power feeding circuit 56.

  FIG. 3 is a diagram illustrating a change in signal power accompanying antenna power feeding. In FIG. 3, “antenna feeding” is the presence / absence of feeding by the antenna feeding circuit 56, and the vertical axis represents the feeding voltage and the horizontal axis represents the elapsed time. “Signal power” is the signal power detected by the signal power detection unit 84, where the vertical axis indicates the detected power value, and the horizontal axis indicates the elapsed time. As shown in FIG. 3, in the case of an active antenna, the signal power increases with temporary power feeding, so that the antenna device 10 is an active antenna by monitoring the increase in signal power. Can be determined. After this determination is made, a continuous power supply operation is started. On the other hand, in the case of a passive antenna, since the signal power does not increase with temporary power feeding, it is possible to determine that the antenna device 10 is a passive antenna by monitoring how the signal power does not change. . If this determination is made, the subsequent power feeding operation becomes invalid and power feeding is not performed.

  Note that the above-described antenna type determination can be performed regardless of the signal reception state (regardless of whether the signal is actually received). When the antenna booster amplifier 14 operates, the noise floor rises and the signal power increases even if there is no signal input, so that it is possible to identify the presence or absence of the antenna booster amplifier 14, that is, whether it is an active antenna or a passive antenna. .

  As described above, in the in-vehicle device 50 of the present embodiment, the antenna power supply circuit 56 temporarily supplies power to the antenna device 10, and the antenna type is automatically determined based on the signal level at that time. Depending on the type of antenna to be used, it is possible to automatically set whether or not to supply power. Moreover, since the user does not need to set the type of antenna, erroneous setting can be prevented.

  Further, by setting the temporary power supply for determining the antenna type for a predetermined time, the influence on the original receiving operation of the in-vehicle device 50 can be reduced. Further, based on the change in signal power as the signal level, it is possible to accurately identify whether the antenna booster amplifier 14 is operating, that is, whether the antenna booster amplifier 14 is included in the antenna device 10.

  Further, when the antenna type is determined in accordance with an instruction from the user, the presence / absence of power supply can be automatically set according to the antenna type when the in-vehicle device 50 is mounted on the vehicle or at an arbitrary timing. It becomes possible.

  Further, the determination of the antenna type is performed every time the in-vehicle device 50 is started or starts running (when the vehicle key switch is turned on). The automatic setting can be surely performed.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention. For example, in the above-described embodiment, the in-vehicle device 50 as a DAB receiver has been described. However, other in-vehicle devices such as an AM / FM tuner, a TV tuner, a mobile phone, and the like, and an active antenna mounted on the vehicle, The present invention can be applied to an in-vehicle device that can be connected to any of the passive antennas.

  In the above-described embodiment, the type of antenna is determined based on a change in signal power accompanying temporary power supply. However, the type of antenna is determined based on a change in signal level (for example, signal amplitude) other than signal power. You may make it determine.

  As described above, according to the present invention, the antenna device is temporarily fed by the feeding circuit, and the antenna type is automatically determined based on the signal level at that time, so that the antenna type to be combined is determined. Accordingly, the presence or absence of power supply can be automatically set.

DESCRIPTION OF SYMBOLS 10 Antenna apparatus 12 Antenna 14 Antenna booster amplifier 50 In-vehicle apparatus 52 Capacitor 54 Coil 56 Antenna feeding circuit 60 Tuner part 62 Analog-digital converter (A / D)
64 FE (front end) unit 66 BE (back end) unit 68 output processing unit 80 main control unit 82 power supply instruction unit 84 signal power detection unit 86 antenna determination unit

Claims (7)

In an in-vehicle device that feeds power when an antenna amplifier is included in an antenna device mounted on a vehicle,
A power feeding circuit for feeding power to the antenna amplifier;
Detecting means for detecting a level of a signal output from the antenna device;
Power supply instruction means for instructing the power supply circuit to supply power to the antenna amplifier;
An antenna determination unit that determines the type of antenna based on the signal level detected by the detection unit when temporary power supply is performed in response to an instruction from the power supply instruction unit;
A vehicle-mounted device comprising: In claim 1,
The type of antenna is either an active antenna that includes the antenna amplifier or a passive antenna that does not include the antenna amplifier.
The power supply instructing unit performs a setting to enable a power supply operation by the power supply circuit when the antenna determining unit determines that the antenna type is an active antenna, and the antenna type is a passive antenna. A vehicle-mounted device that performs setting to invalidate a power feeding operation by the power feeding circuit when judged by a judging means. In claim 1 or 2,
A vehicle-mounted device characterized in that temporary power feeding performed to determine the type of antenna is performed for a predetermined time. In any one of Claims 1-3,
The detection means detects the power of the signal;
The on-vehicle apparatus characterized in that the antenna determination means determines the type of antenna based on a change in signal power corresponding to the presence or absence of temporary power feeding. In any one of Claims 1-4,
The in-vehicle apparatus according to claim 1, wherein the antenna type determination by the antenna determination unit is performed in accordance with an instruction from a user. In any one of Claims 1-4,
The on-vehicle device is characterized in that the antenna type determination by the antenna determining means is performed when the on-vehicle device is activated. In any one of Claims 1-4,
The in-vehicle apparatus according to claim 1, wherein the antenna type determination by the antenna determination means is performed at a timing when a key switch of the vehicle is turned on.

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