JP2014153160A - Radar device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform accurate distance calculation by suppressing an influence due to the delay of a signal transmission time with simple configurations in a radar device in which a sensor part and a measurement part are stored in individual casings.SOLUTION: In a sensor part 10, a transmission/reception part 45 transmits a radar wave in accordance with a trigger signal, and receives the reflection wave, and AD-converts a reception signal in a preliminarily set AD conversion period, and an embedment signal generation part 47 generates, by defining the AD-converted data as AD reception data, and defining the data row of the AD reception data as an AD reception signal, an embedment signal in which a trigger correspondence signal indicating a timing in which the trigger signal has been output is embedded in the AD reception signal. The embedment signal is transmitted to the measurement part 20. In the measurement part 20, a measurement control part 87 measures a peak time required for the reciprocation of the radar wave to/from a target with the timing in which the trigger correspondence signal has appeared as a start point in the received embedment signal, and calculates a distance to the target having reflected the radar wave by using the peak time.

Description

  The present invention relates to a radar apparatus that detects a target that reflects a transmission wave by transmitting a radar wave and receiving the reflected wave.

  Conventionally, by transmitting a radar wave, receiving the reflected wave, and measuring the time difference from the transmission timing of the radar wave to the reception timing of the reflected wave, at least the distance to the target reflecting the transmitted radar wave is measured. A radar device is known (see Patent Document 1).

JP 2005-257405 A

  By the way, in the above-described radar apparatus, when each component of the radar apparatus is accommodated in one casing, there is a problem that the casing becomes large and the degree of freedom in installing the radar apparatus is reduced.

  Therefore, the above-described radar device is divided into two parts: a sensor unit that transmits at least a radar wave and receives the reflected wave, and a measurement unit that measures a distance to a target that reflects at least the radar wave. It is conceivable that the degree of freedom of installation can be improved by accommodating the individual cases and making the individual cases smaller.

  Here, for example, the measurement unit generates a trigger signal, the sensor unit uses the trigger signal as a trigger to transmit and receive a radar wave to the target, and the measurement unit triggers based on the reflected wave received by the sensor unit. A configuration is conceivable in which the round trip time of the radar wave to the target is calculated from the generation of the signal, and the distance from the round trip time to the target is measured.

  However, in the radar device in which the sensor unit and the measurement unit are housed in separate housings as described above, a transmission / reception element for transmitting and receiving signals between the sensor unit and the meter side unit is required. The temperature characteristics of the transmission time and the reception time may cause a delay in signal transmission time that affects the distance measurement. Further, when the sensor unit and the measurement unit are connected with a cable, there is a concern that the delay of the signal transmission time becomes a size that cannot be ignored in measuring the distance depending on the length of the cable.

  Here, it is conceivable to measure the temperature characteristics of the delay time generated in the transmitting / receiving element in advance, measure the delay time due to the cable length fixed in advance, and suppress the influence of the delay using these measurement results. However, in this case, a circuit for correcting the temperature characteristic is required, which causes a problem that the configuration of the radar apparatus is complicated. In addition, it is necessary to always use a fixed-length cable that has been measured in advance, which causes a problem that the degree of freedom in arrangement is reduced.

  The present invention has been made in view of such problems, and in a radar device in which a sensor unit and a measurement unit are housed in separate housings, the influence of a delay in signal transmission time is suppressed by a simple configuration, The object is to improve the detection accuracy. Another object of the present invention is to improve the degree of freedom of arrangement in a radar apparatus in which a sensor unit and a measurement unit are housed in separate housings.

  The radar apparatus according to claim 1, wherein the radar apparatus according to claim 1 is configured to detect a strength of a received signal by transmitting and receiving a radar wave, and a measurement unit that measures at least a distance according to a detection result of the detection unit. Is provided. The detection means includes trigger output means, transmission / reception means, embedded signal generation means, and embedded signal transmission means. The trigger output means outputs a trigger signal. The transmission / reception means transmits a radar wave according to the trigger signal, receives the reflected wave, and AD-converts the received signal at a preset AD conversion cycle.

  The embedded signal generating means uses the data AD-converted by the transmission / reception means as AD reception data, the data string of the AD reception data as an AD reception signal, and a trigger that indicates the timing at which the trigger signal is output to the AD reception signal An embedded signal in which a corresponding signal is embedded is generated. The embedded signal transmitting unit transmits the embedded signal to the measuring unit.

  The measuring means includes an embedded signal receiving means and a target measuring means. The embedded signal receiving unit receives the embedded signal from the embedded signal transmitting unit. The target measuring means measures at least the distance to the target reflecting the transmitted radar wave using the timing at which the trigger corresponding signal appears in the embedded signal received by the embedded signal receiving means.

  According to such a radar apparatus, the detection means performs distance measurement using the embedded signal in which both the timing at which the radar wave is transmitted and the timing at which the radar wave is received appear. In other words, since the embedded signal holds the relative relationship between the timing at which the radar wave is actually transmitted and the timing at which it is received, the signal generated between the detection means and the measurement means housed in a separate housing The influence of the transmission delay is suppressed, and at least the distance detection accuracy can be improved. In addition, since it is not necessary to compensate for the temperature characteristics of the delay time generated in the transmission / reception elements included in each housing, the radar apparatus can be configured simply.

  Further, in the radar apparatus of the present invention, for example, when the detection unit and the measurement unit are connected by a cable, it is not necessary to consider the influence of the signal transmission delay in the cable. The means and the measuring means can be connected. As a result, the degree of freedom of arrangement in the radar apparatus can be improved.

1 is a block diagram illustrating a radar device according to a first embodiment. It is a timing chart which shows the signal in each part of a sensor part. It is a timing chart of a reference clock, an embedded signal, and a transmission data clock. It is a flowchart of a distance detection process. It is explanatory drawing explaining the measurement of the peak time in an embedded signal, (a) is a timing chart which shows a measurement reference clock, (b) is explanatory drawing which shows each data of an embedded signal in time series, (c ) Is an explanatory diagram in which the value of each data of the embedded signal is plotted in synchronization with the rise of the measurement reference clock, and (d) is an explanatory diagram illustrating the peak time. It is explanatory drawing explaining operation | movement in a comparative example, (a) is a timing chart which shows a trigger signal, (b) is a timing chart which shows a trigger timing signal, (c) is explanatory drawing which shows a light reception waveform. is there. It is a block diagram which shows the radar apparatus of 2nd Embodiment. It is a block diagram which shows the radar apparatus of 3rd Embodiment. It is a block diagram which shows the radar apparatus of 4th Embodiment. It is a block diagram which shows the embedded signal generation part of the radar apparatus of 5th Embodiment.

Embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
[overall structure]
As shown in FIG. 1, a radar apparatus 1 to which the present invention is applied includes a sensor unit 10 that transmits and receives laser light as a radar wave to detect the intensity of a received signal, and at least a radar wave according to a detection result of the sensor unit 10. And a measuring unit 20 that measures the distance to the reflected target. Hereinafter, description will be given with reference to FIG.

[Sensor part]
The sensor unit 10 includes a clock reception unit 41, a trigger output unit 43, a transmission / reception unit 45, an embedded signal generation unit 47, and a serializer 49.

  The clock receiving unit 41 includes a differential receiver, and supplies the clock input from the twisted pair cable 33 to the trigger output unit 43, the transmission / reception unit 45, the embedded signal generation unit 47, and the serializer 49 as the reference clock a1.

  The trigger output unit 43 includes a trigger receiver 51 including a differential receiver that outputs a trigger signal c input from the twisted pair cable 31 and a synchronization obtained by synchronizing the trigger signal c input from the trigger receiver 51 with a reference clock a1. Trigger synchronization circuit 53 for outputting the synchronization trigger signal d, and trigger delay circuit for outputting the trigger timing signal e obtained by delaying the synchronization trigger signal d by an AD delay time (here, one clock of the reference clock a1) described later (Refer to FIG. 2 for the timings of the signals a1, c, d, and e).

  The transmitter / receiver 45 receives a reflected light of the laser beam from the target to be measured and emits a laser beam as a radar wave according to the synchronization trigger signal d, and a voltage corresponding to the intensity of the reflected light The light receiving unit 63 that outputs an analog signal (light receiving signal) having a value and the light receiving signal (from the light receiving unit 63 with a preset AD conversion cycle based on the reference clock a1 supplied from the clock receiving unit 41) And an AD converter 65 that performs AD conversion by sampling the received light waveform. Here, the AD conversion cycle is equal to the cycle of the reference clock a1.

  The AD converter 65 delays the AD delay time corresponding to N clocks (here, N = 1) of the reference clock a1 from the input of the received light waveform, and then converts the received light signal into digital data (AD reception). Data). The delay in the above-described trigger delay circuit 55 is set to be equal to this AD delay time.

  Here, the AD converter 65 converts the AD reception data into digital data represented by 16 bits with a sign (the normal range that can be taken as a numerical value is −32768 to +32767), and 1 bit is converted into this. A total of 17 bits of parallel data including the overflow occurrence bits is output. The overflow occurrence bit becomes 1 when the value of the received light signal is larger than the maximum value (32767) of the normal range or smaller than the minimum value (−32768).

  That is, the overflow occurrence bit is commonly used when an underflow occurs and when an overflow occurs. When the overflow occurs, the output of the AD converter 65 remains at the maximum value and the overflow occurrence bit becomes 1. When the underflow occurs, the AD converter 65 The output remains at the minimum value and the overflow occurrence bit becomes 1. When the value of the received light signal is within the normal range, the overflow occurrence bit is 0. Hereinafter, a data string in which AD reception data is arranged in time series is referred to as an AD reception signal f.

  Returning to FIG. 1, the embedded signal generation unit 47 is input from the trigger corresponding signal output unit 71 that outputs the trigger corresponding signal TS, the trigger corresponding signal TS input from the trigger corresponding signal output unit 71, and the AD converter 65. And a multiplexer 73 that generates an embedded signal g using the AD reception signal f. Specifically, the multiplexer 73 normally selects the AD reception signal f and sequentially outputs AD reception data. However, when the trigger timing signal e is input from the trigger delay circuit 55, the trigger corresponding signal TS is selected and output instead of the AD reception data.

  That is, the embedded signal g is a signal in which the trigger corresponding signal TS indicating the timing at which the laser light is emitted is embedded in the AD reception signal f. In the example shown in FIG. 2, the timing at which the laser beam is emitted corresponds to the timing at which an analog signal corresponding to the data (AD reception data) ADn of the AD reception signal f appears in the light reception waveform. A trigger corresponding signal TS is output instead of the data ADn.

  The trigger corresponding signal TS is set so as to be distinguishable from the AD reception data. Here, the trigger corresponding signal TS is data that the AD converter 65 cannot output, that is, a numerical value M within the normal range output by the AD converter 65 (minimum value <M <maximum value, for example, M = 0). The data is set to a total of 17 bits by adding 1 as an overflow occurrence bit to the signed 16-bit data.

  FIG. 3 shows a timing chart of the reference clock a1, the embedded signal g, and the embedded signal g. The embedded signal g generated in this way is output to the serializer 49.

  The serializer 49 converts the embedded signal g, which is 17-bit parallel data, into serial data in synchronization with the reference clock a1, and transmits a transmission data clock for transmitting the serial data (here, the reference clock a1 is 17 or more). This is a well-known one that encodes the clock information of the clock frequency multiplied by 2 (see FIG. 3) and generates transmission data D in which the clock information is added to the serial data.

  The embedded signal g in which the clock information is encoded is serially output by the serializer 49 in units of 1 bit while being bit-shifted sequentially from the MSB (or LSB) in synchronization with the transmission data clock. The serializer 49 converts the generated transmission data D into a differential signal and outputs it to the cable 35.

[Measurement section]
Returning to FIG. 1, the measurement unit 20 includes a trigger transmission unit 81, a clock generation unit 82, a clock transmission unit 83, a transmission data reception unit 84, a measurement control unit 87, and a display unit 88. The trigger transmission unit 81 includes a differential driver, converts the trigger signal b input from the measurement control unit 87 into a differential signal, and outputs the differential signal to the twisted pair cable 31.

  The clock generation unit 82 generates the measurement reference clock a and supplies it to the clock transmission unit 83, the measurement control unit 87, and the transmission data reception unit 84. The clock transmission unit 83 includes a differential driver, converts the measurement reference clock a supplied from the clock generation unit 82 into a differential signal, and outputs the differential signal to the twisted pair cable 33. The measurement reference clock a and the reference clock a1 of the sensor unit 10 are set to the same frequency.

The transmission data receiving unit 84 includes a deserializer 91, a data recovery circuit 93, and a clock synchronization circuit 95.
The deserializer 91 operates in accordance with the measurement reference clock a, outputs an embedded signal s restored as 17-bit parallel data from transmission data D input as a differential signal via the twisted pair cable 35, and uses clock information. This is a well-known clock that restores and outputs a clock having the same cycle as the reference clock a1.

The data recovery circuit 93 latches and outputs the embedded signal h input from the deserializer 91 with the reference clock k restored by the deserializer 91.
The clock synchronization circuit 95 operates in accordance with the measurement reference clock a, and synchronizes the embedded signal s input from the data recovery circuit 93 with the measurement reference clock a and outputs it. The embedded signal s is input to the measurement control unit 87.

  The measurement control unit 87 includes a known microcomputer mainly composed of a CPU, a ROM, and a RAM, and executes a process of outputting the trigger signal b at a predetermined cycle. Further, the measurement control unit 87 executes a distance detection process for detecting the distance to the target reflecting the laser beam using the input embedded signal s. The display unit 88 outputs the measurement result output from the measurement control unit 87 to a display (not shown) or the like.

[Processing in the measurement control unit]
Next, distance detection processing executed by the measurement control unit 87 will be described with reference to the flowchart shown in FIG. This process is repeatedly activated at predetermined intervals corresponding to the output cycle of the trigger signal b. When this process is started, first, in step (hereinafter simply referred to as “S”) 10, an embedded signal s that changes in accordance with the measurement reference clock a is acquired (see FIGS. 5A and 5B).

  Next, in S20, the trigger corresponding signal TS is detected from the embedded signal s, and in the subsequent S30, the position of the peak vertex in the received light waveform (restored received light waveform) restored from the individual AD reception data of the embedded signal s is estimated ( (See (c) in the figure). The position of the peak apex is a position where the intensity in the reconstructed received light waveform is estimated to be the maximum value after the trigger corresponding signal TS is detected. For the estimation, various known methods (for example, see JP-A-2005-257405). ) Can be used, and the description is omitted here.

  Next, in S40, the peak time, which is the time from when the trigger corresponding signal TS appears in the embedded signal s until the estimated peak vertex (estimated peak vertex) appears, is measured (see FIG. 4D). The distance to the target is calculated using the peak time. Since the peak time is the time when the laser light travels back and forth the distance (d) to the target, the distance to the target is determined by using the peak time (Tp) with the speed of the laser light as the speed of light (c). Calculated by the formula.

Finally, in S50, the calculated distance is output, and this process is terminated.

[effect]
As described above, in the radar apparatus 1, the sensor unit 10 and the measurement unit 20 are housed in separate housings, and the sensor unit 10 generates a trigger signal generated by the measurement unit 20 via the twisted pair cable 31. And irradiates laser light in accordance with the trigger signal. The received waveform from the target to be measured is transmitted to the measuring unit 20 via the twisted pair cable 35, and the measuring unit 20 measures the peak time from the received waveform and calculates the distance to the target.

  Furthermore, the radar apparatus 1 uses the embedded signal s in which the measurement unit 20 shows both the timing at which the radar wave is transmitted (trigger-corresponding signal TS) and the timing at which the radar wave is received (estimated peak apex). It is configured to detect and calculate the distance.

  According to this, since the embedded signal s holds the relative relationship between the timing at which the radar wave is actually transmitted and the timing at which it is received, the peak time can be correctly measured. That is, by calculating the distance using the embedded signal s, the influence of the signal transmission delay that occurs between the sensor unit 10 and the measurement unit 20 housed in the individual housing is suppressed, and the accurate distance detection result Can be obtained.

  Here, as a comparative example, unlike the present invention, in a radar apparatus in which the sensor unit 10 and the measurement unit 20 are housed in separate housings, the peak time when the embedded signal is not used just by connecting with a twisted pair cable is used. An example of detection is shown in FIG. In this case, the measuring unit measures the peak time Tk, which is the sum of the correct peak time Tp to be originally detected and the delay time Td generated by the operation of the transmission / reception element. That is, when the embedded signal is not used, the peak time is measured starting from the timing at which the trigger signal is generated by the measurement unit 20, so that a distance error corresponding to the delay time Td occurs and the correct distance to the target is generated. It can be seen that the detection result cannot be obtained.

  In the radar apparatus 1, the trigger corresponding signal TS appears much earlier in time series than the peak apex in the embedded signal s. Therefore, the AD reception data (the embedded signal g in FIG. 5) replaced with the trigger corresponding signal TS. The lack of the AD reception data ADn) does not affect the detection of the estimated peak vertex.

  Since this trigger corresponding signal TS is set to a value that cannot be obtained by normal AD reception data, it can be easily identified from the embedded signal s, that is, the data string of the AD reception data.

  In the radar apparatus 1, the delay time generated by the transmission / reception units (the trigger transmission unit 81, the trigger reception unit 51, the clock transmission unit 83, the clock reception unit 41, the serializer 49, and the deserializer 91) included in the sensor unit 10 and the measurement unit 20. Since it is not necessary to compensate for the temperature characteristics, the apparatus configuration can be simplified.

  Furthermore, in the radar apparatus 1 of the present invention, there is no need to consider the influence of signal transmission delay on the twisted pair cables 31, 33, 35 connecting the sensor unit 10 and the measurement unit 20. The unit 10 and the measurement unit 20 can be connected. As a result, the degree of freedom of arrangement of the radar device 1 can be improved.

  Moreover, in the radar apparatus 1 of the present invention, the data transmitted between the sensor unit 10 and the measurement unit 20 is transmitted as serial data, so the number of cables 35 can be reduced. As a result, the configuration of the radar apparatus 1 can be simplified and the degree of freedom in arrangement can be further improved.

  Such a radar apparatus 1 of the present invention may be applied to a radar apparatus mounted on a vehicle. For example, there may be a case where only the sensor unit 10 is installed in the vehicle interior and the measurement unit 20 is installed outside the vehicle interior (for example, inside the trunk). In such a case, the sensor unit 10 and the measurement unit 20 Since there is no need to consider the influence of signal transmission delay due to the length of the cable connecting the cables, a cable having an arbitrary length can be used. Moreover, since the sensor part 10 can be reduced in size, the freedom degree of arrangement | positioning in a vehicle interior can be improved.

[Correspondence with Claims]
The sensor unit 10 corresponds to “detection unit” in the claims, the measurement unit 20 corresponds to “measurement unit” in the claims, and the clock reception unit 41 corresponds to “AD clock reception unit” in the claims. The trigger output unit 43 corresponds to “trigger output means” in the claims, and the transmission / reception unit 45 corresponds to “transmission / reception means” in the claims.

  The embedded signal generation unit 47 corresponds to “embedded signal generation means” in the claims, the serializer 49 corresponds to “embedded signal transmission means” in the claims, and the trigger delay circuit 55 corresponds to the claims. Corresponds to “AD delay adjusting means”. The trigger transmission unit 81 corresponds to “trigger transmission means” in the claims, the clock transmission unit 83 corresponds to “AD clock transmission means” in the claims, and the transmission data reception unit 84 claims. It corresponds to “embedded signal receiving means” in the range, and the measurement control unit 87 corresponds to “measurement control means” in the claims.

[Second Embodiment]
A second embodiment will be described.
The configuration of the radar apparatus 2 according to the present embodiment will be described with a focus on the different parts of the configuration of the sensor unit 10 and the measurement unit 20 because they are different from those of the first embodiment.

  In the radar device 2 of the present embodiment, as shown in FIG. 7, the trigger transmission unit 81 is deleted in the measurement unit 20 and the sensor unit 10 as compared with the configuration of the radar device 1 shown in FIG. 1. The trigger receiving unit 51 is replaced with a trigger generating unit 52. Accordingly, the twisted pair cable 31 is deleted.

  The trigger generation unit 52 generates a pulse signal having a predetermined period and outputs the pulse signal as a trigger signal c1. Then, according to the trigger signal c1 generated by the sensor unit 10, the light emitting unit 61 emits laser light, and the embedded signal generating unit 47 generates the embedded signal g in which the trigger corresponding signal TS is embedded.

  That is, in the radar apparatus 2, the measurement unit 20 transmits the radar wave held in the embedded signal g regardless of whether or not the timing at which the sensor unit 20 actually transmits the radar wave is detected. The distance can be calculated using the relative relationship between the received timing (trigger corresponding signal TS) and the received timing (peak vertex).

  Therefore, the radar device 2 has the same effect as the above embodiment. In addition, since the twisted pair cable 31 for transmitting the trigger signal from the measurement unit 20 in the above embodiment is not required, the configuration is simplified, and the degree of freedom of arrangement of the housing of the sensor unit 10 and the housing of the measurement unit 20 is increased. Can be improved.

  Since the radar device 2 is configured to transmit a radar wave triggered by the trigger signal c1 generated on the sensor unit 10 side, the sensor unit 10 may be replaced according to the purpose using the measurement unit 20 as a common member. Good.

For example, when the measurement target is a target existing at a short distance, the radar device is configured using a sensor unit (low output sensor unit) configured so that the transmission power of the radar wave is low, and the measurement target May be configured using a sensor unit configured so that the transmission power of the radar wave is high output instead of the low output sensor unit. Thereby, the versatility of a radar apparatus can be improved. The trigger generation unit 52 corresponds to “trigger signal generation means” in the claims.
[Third Embodiment]
A third embodiment will be described.

The apparatus configuration of the radar apparatus 3 according to the present embodiment will be described mainly with respect to different parts of the configuration of the sensor unit 10 and the measurement unit 20 because they are partially different from those of the second embodiment.
In the radar device 3 of the present embodiment, as shown in FIG. 8, the clock transmission unit 83 is deleted in the measurement unit 20 and the sensor unit 10 as compared with the configuration of the radar device 2 shown in FIG. Thus, the clock receiver 41 is replaced with a clock generator 42.

  The clock generation unit 42 generates a clock having the same cycle as the measurement reference clock a of the measurement unit 20 as an AD clock. That is, in the sensor unit 10, the AD converter 65 performs AD conversion according to the AD clock generated by the sensor unit 10, and the serializer 49 performs serial transmission with a data transmission clock obtained by multiplying the AD clock by 17 times. .

  As described above, clock information of the data transmission clock is added to the transmission data D transmitted by the serializer 49, and in the measurement unit 20, the deserializer 91 restores and outputs this data transmission clock. Then, the embedded signal h1 received by the deserializer is latched by the data recovery circuit 93 using the restored data transmission clock k, so that the embedded signal synchronized with the AD clock is restored.

  As described above, in the radar apparatus 3, the twisted pair cable 33 for transmitting the measurement reference clock from the measurement unit 20 in the above embodiment is not necessary, so that the configuration is further simplified, and the housing of the sensor unit 10 and the measurement are measured. The degree of freedom of arrangement of the unit 20 with the housing can be further improved. The clock generation unit 42 corresponds to “AD clock generation means” in the claims.

[Fourth Embodiment]
In the radar device 2 according to the second embodiment, the trigger transmission unit 81 is deleted in the measurement unit 20 and the trigger reception unit 51 in the sensor unit 10 as compared with the configuration of the radar device 1 shown in FIG. Is replaced with the trigger generation unit 52.

  On the other hand, as shown in FIG. 9, the radar device 4 of the present embodiment is compared with the configuration of the radar device 1 shown in FIG. The clock receiving unit 41 may be replaced with the clock generating unit 42 in the unit 10. Here, the clock generation unit 42 has the same configuration as that of the clock generation unit 42 of the third embodiment, and the sensor unit 10 operates according to the AD clock as in the third embodiment, and thus detailed description thereof is omitted. .

That is, in the radar device 4, each part of the sensor unit 10 operates according to the AD clock generated by the sensor unit 10 and according to the trigger signal generated by the measurement unit 20.
As a result, the radar apparatus 4 does not require the twisted pair cable 33 for transmitting the measurement reference clock from the measurement unit 20 in the first embodiment, so that the configuration is simplified and the housing of the sensor unit 10 and the measurement unit 20 are simplified. The degree of freedom of arrangement with the casing can be improved.

[Fifth Embodiment]
A fifth embodiment will be described.
The configuration of the radar apparatus according to the present embodiment will be described mainly with respect to the different parts of the configuration of the embedded signal generation unit 47, which is partially different from that of the above embodiment.

  In the radar apparatus of the present embodiment, as shown in FIG. 10, the embedded signal generation unit 47 is deleted as compared with the configuration of the radar apparatus 1 shown in FIG. 1, and the AD reception signal f and the trigger timing signal are sent to the serializer 49. e is input. That is, the serializer 49 converts parallel data of a total of 18 bits obtained by adding the trigger timing signal e (1 bit) to the AD reception signal f (17 bits parallel data) to serial data. In the present embodiment, this 18-bit parallel data corresponds to an embedded signal.

  Here, in other words, the trigger timing signal e is a 1-bit signal that takes a binary value represented by 1 or 0 as to whether or not the trigger signal is output. The serializer 49 adds the trigger timing signal e to the AD reception signal f as the trigger corresponding signal to generate an embedded signal. The generated embedded signal is transmitted to the measuring unit 20 as in the above embodiment, and the measuring unit 20 measures the peak time based on the embedded signal and calculates the distance to the target.

As described above, since the radar apparatus according to the present embodiment does not require a multiplexer, the same effects as those of the above-described embodiment can be achieved with a simpler configuration.
The serializer 49 corresponds to the “embedded signal generation unit” and the “embedded signal transmission unit” in the claims, and the trigger timing signal e input to the serializer 49 corresponds to the “trigger corresponding signal” in the claims. To do.

[Other Embodiments]
As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, In the range which does not deviate from the summary of this invention, it is possible to implement in various aspects.

  (A) In the above embodiment, the transmission data D is transmitted as serial data. However, the transmission data D may be transmitted as parallel data. As a result, similarly to the above embodiment, the peak time can be detected correctly and the distance can be calculated regardless of the signal transmission delay due to the length of the cable and the operation of the transmitting / receiving element.

  (B) In the above embodiment, the transmission data D is transmitted by the cable 35. However, the transmission data D may be transmitted by wireless transmission without using the cable. Alternatively, the transmission data D may be replaced with an optical signal instead of an electric signal, and an optical communication cable may be used. This is effective when the sensor unit and the measurement unit are installed at a distance.

  (C) In the first to third embodiments, the trigger corresponding signal TS is a 17-bit signal. However, the present invention is not limited to this, and the trigger corresponding signal is a binary signal having an arbitrary number of bits. Good. In the fourth embodiment, the trigger corresponding signal is a 1-bit signal. However, the trigger corresponding signal is not limited to this, and the trigger corresponding signal may be a binary signal having an arbitrary number of bits.

  (D) In the above embodiment, laser light is used as a radar wave. However, the present invention is not limited to this, and the present invention determines the distance to the target by measuring the round-trip time of the radar wave to the target. The present invention can be applied to all radar systems that calculate.

  (E) In the above embodiment, the measurement result output from the measurement control unit 87 is output to the display or the like by the display unit 88. However, the radar apparatus may be configured so that the measurement result is used for various controls.

  1, 2, 3 ... Radar device 10 ... Sensor unit 20 ... Measurement unit 43 ... Trigger output unit 45 ... Transmission / reception unit 47 ... Embedded signal generation unit 84 ... Transmission data reception 55 ... Trigger delay circuit 81 ... Trigger transmission unit 87 ... Measurement control unit

Claims (9)

A radar apparatus comprising: detection means (10) for detecting the intensity of a received signal by transmitting and receiving radar waves; and measurement means (20) for measuring at least a distance according to a detection result of the detection means,
The detection means includes
Trigger output means (43) for outputting a trigger signal;
Transmission / reception means (45) for transmitting a radar wave in accordance with the trigger signal, receiving the reflected wave, and AD converting the received signal at a preset AD conversion cycle;
The data converted by the transmission / reception means is AD reception data, the data string of the AD reception data is an AD reception signal, and a trigger corresponding signal indicating the timing at which the trigger signal is output is embedded in the AD reception signal. Embedded signal generating means (47) for generating an embedded signal;
Embedded signal transmitting means (49) for transmitting the embedded signal to the measuring means;
With
The measuring means includes
Embedded signal receiving means (84) for receiving the embedded signal transmitted by the embedded signal transmitting means;
Measurement control means (87) for measuring a distance to a target reflecting at least the transmitted radar wave, using the timing at which the trigger corresponding signal appears in the embedded signal received by the embedded signal receiving means;
A radar apparatus (1, 2, 3) comprising: The radar apparatus according to claim 1,
The radar apparatus, wherein the embedded signal transmitted from the embedded signal transmitting unit and received by the embedded signal receiving unit is serial data. The radar apparatus according to claim 1 or 2,
The trigger corresponding signal is distinguishable from the AD reception data,
The radar apparatus according to claim 1, wherein the embedded signal generating means generates the embedded signal by outputting the AD reception data and outputting the trigger corresponding signal instead of the AD reception data. The radar apparatus according to claim 1 or 2,
The trigger-corresponding signal is a signal having a predetermined number of bits that takes a binary value indicating whether or not the trigger signal is output.
The radar apparatus according to claim 1, wherein the embedded signal generating means generates the embedded signal by adding the trigger corresponding signal to the AD reception data. The radar apparatus according to any one of claims 1 to 4,
The trigger output means causes the transmission / reception means to transmit a radar wave, with the time required for the signal data input by the transmission / reception means to be AD converted and output as the AD reception data as an AD delay time. A radar apparatus comprising AD delay adjusting means (55) for adjusting timing so that the trigger corresponding signal appears in the embedded signal after the AD delay time from when a trigger signal is transmitted. The radar apparatus according to any one of claims 1 to 5,
The measurement means includes trigger transmission means (81) for generating and transmitting a pulse signal having a predetermined period,
The radar apparatus (1), wherein the trigger output means outputs the pulse signal received from the trigger transmission means as the trigger signal. The radar apparatus according to any one of claims 1 to 5,
The radar apparatus (2), wherein the trigger output means includes a trigger signal generation means (52) that generates a pulse signal having a predetermined period and outputs the pulse signal as the trigger signal. The radar apparatus according to any one of claims 1 to 5,
The measurement means includes AD clock transmission means (82, 83) for generating and transmitting a clock having the AD conversion cycle as an AD clock,
The detecting means includes AD clock receiving means (41) for receiving and outputting the AD clock generated by the measuring means,
The radar apparatus (1), wherein the transmission / reception means performs AD conversion in accordance with the AD clock output from the AD clock reception means. The radar apparatus according to any one of claims 1 to 5,
The detection means includes AD clock generation means (42) for generating a clock having the AD conversion cycle as an AD clock,
The radar apparatus (3), wherein the transmission / reception means performs AD conversion according to the AD clock generated by the AD clock generation means.