JP2008215937A - Combined mode radar system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a combined mode radar system capable of precisely measuring a position and reducing interferences with other systems, by using a narrow-band radar and a wide-band radar together and operating them so as to act along with each other. <P>SOLUTION: The combined mode radar system 100 has a narrow-band radar section 102 and a wide-band radar section 103 being disposed in the same case and is configured such that both sections are operated along with each other under control of an arithmetic section 101. Data sets measured by the narrow-band radar section 102 and the wide-band radar section 103 are input to the arithmetic section 101, and an operation of measuring a distance is carried out precisely in the arithmetic section 101, based on the measured data sets input from the both sections. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technical field of an on-vehicle radar device using radio waves, and particularly to a technical field of a composite mode radar device using a plurality of frequency band modes.

  Many techniques have already been disclosed for the function of measuring position data such as the distance and angle to an object using radio waves, that is, the radar function. For example, a radar using a pulse repeatedly transmitted monotonously as a distance measuring function is known. In addition, as radar using continuous wave (CW: Continuous Wave), Doppler radar that detects the speed using a continuous wave of a single frequency, or ranging and speed detection using a band of several tens to 200 MHz An FMCW (Frequency Modulated Continuous Wave) radar is known (Patent Document 1).

  The conventional radar system uses a system that simply detects a Doppler signal that is returned by outputting a tone signal, or an FMCW system that sequentially changes the frequency in a narrow band up to 200 MHz in time series. In such a system that performs ranging, speed detection, etc. using a narrow-band radio wave, the distance resolution is low, so that, for example, sufficient detection accuracy cannot be obtained when the object is at a short distance of 10 m or less. There was a problem. A 76-GHz band millimeter-wave radar conventionally used for in-vehicle use is a radar suitable for detecting a distance and a relative speed with respect to a vehicle ahead of about 100 m.

  On the other hand, UWB (Ultra Wide Band) radar, which is an ultra-wideband wireless system using a 450 MHz to several GHz band, is known as a new concept wireless communication technology in recent years. ing.

  UWB is an impulse radio system using an ultra-short pulse wave having a pulse width of about nanoseconds or less by making a wide band available. In a ranging system using pulses, a higher resolution can be obtained as the pulse width becomes narrower. Therefore, a high-performance ranging function can be realized by using UWB. On the other hand, by reducing the pulse width, the average transmission power is reduced and the reach distance is shortened. From this, it can be said that UWB is a suitable method for measuring a short distance with high resolution.

  In a UWB wireless system, after transmitting an impulse from a UWB wave transmission source, by measuring the time from when the impulse is reflected by a predetermined object surface and received again by the transmission source, the object and the UWB wave transmission source Can be measured with high accuracy.

  In the UWB wireless system, in the quasi-millimeter wave band of 22 to 29 GHz, an ultrashort pulse wave signal is generated using a wide band of 450 MHz to several GHz, and a conventional radar system using a narrow-band radio wave is sufficient. A high detection accuracy can be obtained in a short-distance measurement of 10 m or less in which a high accuracy was not obtained. For example, an object within about 30 m can be detected with high accuracy of several tens of centimeters.

  On the other hand, since the UWB wireless system uses a wideband frequency, there is a possibility that interference with other wireless systems may be a problem. To prevent this, the output of the UWB signal is kept extremely low. Regulations are being considered. Therefore, it is preferable to lower the signal output by using the UWB wireless system for short distance measurement.

Under such circumstances, studies are being made on a composite mode radar that measures a short distance using a UWB signal and measures a long distance using a narrow-band signal. For example, in Europe, a combination of a narrowband mode Doppler radar using a narrowband signal in the SRD band and a wideband mode UWB radar using a wideband signal obtained by spectrum spreading at the same frequency as the narrowband signal. Mode radar has been studied (Non-Patent Document 1).
Japanese Patent Laid-Open No. 11-271430 Th. Wixforth, W. Ritschel, “Multimode-Radar-Technologie fur 24 GHz,“ auto & elektronik, vol.3 / 2004, pp.56-58

  However, in the composite mode radar described in Non-Patent Document 1, since the frequency band used in the narrowband mode and the frequency band used in the wideband mode are the same or shared, both functions of the narrowband radar and the UWB radar are used. Cannot be used at the same time, and both are switched in a time-sharing manner.

  For this reason, it has not been possible to realize an advanced usage method such as performing high-resolution ranging with a UWB radar during ranging with a narrow-band radar. Also, since the boundary between the measurement range suitable for broadband radar and the measurement range suitable for narrowband radar is ambiguous, it is clear which distance should be switched between broadband radar and narrowband radar. There is also a problem that the dead zone can be generated by operating the narrow area radar and the broadband radar independently.

  Therefore, the present invention has been made to solve the above-described problem, and by performing a cooperative operation using a narrowband radar and a broadband radar in combination, it is possible to perform highly accurate position measurement and It is an object of the present invention to provide a combined mode radar device with reduced interference.

  According to a first aspect of the composite mode radar apparatus of the present invention, a narrowband signal generation unit that generates a narrowband signal having a first frequency as a center frequency, and a second frequency different from the first frequency are centered. A wideband signal generating unit that generates a wideband signal having a frequency, and the narrowband signal and the wideband signal are input and transmitted from the narrowband signal generating unit and the wideband signal generating unit, respectively, and the narrowband signal and the An antenna unit that receives a reflected wave of a wideband signal, a first filtering unit that receives a received signal from the antenna unit and filters the received wave of the narrowband signal, and a received signal that is input from the antenna unit A second filtering unit for filtering the received wave of the wideband signal, and a narrowband receiving unit for detecting the reflected wave of the narrowband signal by inputting the received wave filtered by the first filtering unit And the second filtering section A broadband receiving unit that receives a filtered received wave and detects a reflected wave of the broadband signal, and an arithmetic unit that receives each detected data from the narrowband receiving unit and the broadband receiving unit to determine position data And the first frequency and the second frequency are set to be separated so that the frequency band of the narrowband signal and the frequency band of the wideband signal are separated. .

  In another aspect of the composite mode radar device of the present invention, the wideband receiving unit inputs the narrowband signal from the narrowband signal generation unit and mixes it with the received wave of the wideband signal. The frequency band is down-converted.

  In another aspect of the combined mode radar device of the present invention, the narrowband receiving unit receives the narrowband signal from the narrowband signal generating unit and mixes it with the received wave of the narrowband signal. It is characterized by down-converting the wave frequency band to the baseband.

  In another aspect of the composite mode radar device of the present invention, the narrowband signal generator includes a continuous wave generation source that generates a continuous wave of the narrowband signal, and a switch that performs a switching operation for outputting or blocking the continuous wave. The switch is controlled to perform the switching operation based on a control signal from the arithmetic unit.

  In another aspect of the combined mode radar device of the present invention, the narrowband signal generator is configured to generate the narrowband signal in any one band obtained by dividing a frequency band to be used into two or more. It is controlled by.

  In another aspect of the composite mode radar device of the present invention, the broadband signal generator includes a broadband impulse source that generates the broadband impulse signal, and the broadband impulse source is based on a control signal from the arithmetic unit. It is controlled to generate the impulse signal.

  In another aspect of the composite mode radar device of the present invention, the calculation unit outputs the control signal to at least one of the narrowband signal generation unit and the wideband signal generation unit based on the determination result of the position data. It is characterized by doing.

  According to another aspect of the combined mode radar device of the present invention, the antenna unit is configured to selectively transmit and receive a transmission / reception antenna, and the transmission / reception shared antenna is controlled for transmission or reception by control from the arithmetic unit. An antenna duplexer for switching, and when the transmission / reception shared antenna is switched for transmission, the narrowband signal and the wideband signal are mixed and transmitted, and when the transmission / reception shared antenna is switched for reception Is characterized in that the received signal is demultiplexed into the first filtering unit and the second filtering unit and output.

  In another aspect of the combined mode radar device of the present invention, the antenna unit includes a transmitting antenna and a receiving antenna, and the transmitting antenna mixes and transmits the narrowband signal and the wideband signal. The reception antenna demultiplexes the received signal into the first filtering unit and the second filtering unit and outputs the demultiplexed signal.

  In another aspect of the combined mode radar device of the present invention, the antenna unit includes a narrowband transmitting antenna, a wideband transmitting antenna, a narrowband receiving antenna, and a wideband receiving antenna. The trusted antenna inputs the narrowband signal and transmits it in a predetermined angle range, and the wideband transmitting antenna inputs the broadband signal and transmits it in a wide angle range wider than the predetermined angle range, The narrowband receiving antenna outputs the received signal received from the predetermined angle range to the first filtering unit, and the wideband receiving antenna receives the received signal received from the wide angle range. It outputs to the 2nd filtering part.

  In another aspect of the combined mode radar device of the present invention, the first center frequency and the second center frequency are any of 22 GHz and 29 GHz.

  In another aspect of the composite mode radar device of the present invention, the wideband signal is a UWB signal having a bandwidth of at least 450 MHz.

  As described above, according to the present invention, a combined mode in which narrow-band radar and wide-band radar are used in combination for coordinated operation to enable highly accurate position measurement and reduce interference with other systems. A radar device can be provided. According to the present invention, by combining a narrow-band radar capable of measuring a long distance and a broadband radar capable of measuring a short distance with high accuracy, a combined mode capable of measuring from a short distance to a long distance with high accuracy. A radar apparatus can be provided.

  A composite mode radar apparatus according to a preferred embodiment of the present invention will be described in detail with reference to the drawings. Each component having the same function is denoted by the same reference numeral for simplification of illustration and description. Hereinafter, as a position measurement by the combined mode radar device of the present invention, a distance measuring function for measuring a distance to an object will be described as an example.

  The composite mode radar apparatus of the present invention is configured so that both radar functions can be used simultaneously by dividing so that the frequency band used by the narrowband radar and the frequency band used by the wideband radar do not overlap. . An example of the frequency band used in the composite mode radar apparatus of the present invention is shown in FIG. In the figure, (a) shows the frequency band used in the composite mode radar apparatus of the present invention, and (b) shows the frequency band used in the composite mode radar apparatus studied in Europe described in Non-Patent Document 1. Show.

  In the combined mode radar device described in Non-Patent Document 1, as shown in FIG. 2B, the center frequency of the signal used for the narrowband radar and the center frequency of the signal used for the wideband radar are both about 24 GHz in the same SRD band. Therefore, the narrow band radar band 13 and the wide band radar band 14 overlap. For this reason, narrowband radar and broadband radar cannot be used at the same time, and it has been necessary to switch between the two as required.

  On the other hand, in the combined mode radar device of the present invention, as shown in FIG. 2A, the center frequency of the narrowband radar is set to 24.125 GHz, for example, and the center frequency of the wideband radar is set to 26.5 GHz, for example. The narrow band radar band 11 and the wide band radar band 12 do not overlap, and as a result, they can be used in a coordinated manner without switching. In the following, an embodiment of the combined mode radar device of the present invention configured to have different frequency bands between narrowband radar and wideband radar will be described.

  The basic configuration of the composite mode radar apparatus according to the embodiment of the present invention will be described with reference to the block diagram shown in FIG. The combined mode radar apparatus 100 of the present embodiment is configured such that the narrowband radar unit 102 and the wideband radar unit 103 are provided in the same casing, and both operate cooperatively under the control of the calculation unit 101. ing. Both the data measured by the narrowband radar unit 102 and the wideband radar unit 103 are input to the calculation unit 101 so that the calculation unit 101 can perform distance measurement with high accuracy based on the measurement data input from both. Yes.

  The narrowband radar unit 102 includes a narrowband signal generation unit 110 that generates a narrowband signal, a first filtering unit 131 that filters only a predetermined narrowband received wave from the received signal, and a first filtering. And a narrowband receiving unit 130 that processes the received wave filtered by the unit 131 and acquires detection data. The broadband radar 103 includes a broadband signal generator 120 that generates a broadband signal, a second filtering unit 141 that filters only a predetermined broadband received wave from the received signal, and a second filtering unit 141. And a broadband receiving unit 140 that acquires detection data from the received wave.

  The narrowband signal generation unit 110 and the wideband signal generation unit 120 are respectively provided with a narrowband wave source 111 and a wideband impulse source 121, and the narrowband signal and the wideband signal generated by each are combined by the multiplexer 150. As a result, a transmission signal is transmitted from the antenna unit 160.

  On the other hand, the received signal received by the antenna unit 160 is demultiplexed by the demultiplexer 170 and is output to the first filtering unit 131 and the second filtering unit 141, and the narrow band received wave and the wide band are respectively obtained. The received wave is filtered. The narrowband received wave and the wideband received wave filtered by the first filtering unit 131 and the second filtering unit 141 are input to the narrowband receiving unit 130 and the wideband receiving unit 140, respectively. Predetermined detection data is acquired from the input, and this is input to the calculation unit 101 to perform predetermined processing for distance determination.

  Note that the antenna unit 160 of the present embodiment is configured to perform transmission and reception using the antenna 161 in common, and can switch between transmission and reception using the antenna duplexer 162. As the antenna 161, an antenna that can transmit and receive both a narrowband signal and a wideband signal is used.

  The composite mode radar apparatus 100 of the present embodiment is configured to be able to operate the narrowband radar unit 102 and the broadband radar unit 103 in a coordinated manner under the control of the arithmetic unit 101, and is detected by the narrowband radar unit 102. By combining the measured data and the measurement data detected by the broadband radar unit 103, high-precision distance measurement is possible. That is, the narrowband radar unit 102 and the wideband radar unit 103 can be used in basic operations as shown in FIG. 3, and the narrowband radar unit 102 and the wideband radar unit 103 can be combined by combining these basic operations. A suitable radar function can be realized in cooperation.

  As the basic operation described above, a switching method in which the narrowband radar unit 102 and the wideband radar unit 103 shown in FIG. 3A are switched and operated as appropriate, and the narrowband radar unit 102 and the wideband radar unit shown in FIG. There are two types of parallel use systems in which 103 is operated in parallel. One embodiment for performing distance measurement using such a basic operation will be described below with reference to the flowchart shown in FIG. Such a cooperative operation between the narrowband radar unit 102 and the wideband radar unit 103 is realized by control from the calculation unit 101.

  The processing of FIG. 4 is periodically executed by the calculation unit 101. In step S1, the previously measured distance L0 is compared with the first reference value LT1, and the previously measured distance L0 is the first reference value LT1. If larger, distance measurement is performed using only the narrowband radar unit 102 by the switching method in step S2. If the previously measured distance L0 is equal to or less than the first reference value LT1, the process proceeds to step S3.

  In step S3, the previously measured distance L0 is compared with the second reference value LT2, and if the previously measured distance L0 is less than or equal to the first reference value LT1 and greater than the second reference value LT2, In step S4, the narrow-band radar unit 102 and the wide-band radar unit 103 are operated together using the combined method to perform distance measurement. In this case, the calculation unit 101 can suitably determine the distance by a method such as adopting the shorter distance or calculating the average value of both based on the measurement results of both. .

  If the previously measured distance L0 is less than or equal to the second reference value LT2, in step S5, ranging is performed only by the broadband radar unit 103 using the switching method. As described above, in the combined mode radar device 100 according to the present embodiment, it is possible to realize a highly accurate ranging function by configuring the narrowband radar unit 102 and the wideband radar unit 103 to be used simultaneously. It has become.

  In the processing method shown in FIG. 4, the narrowband radar unit 102 and the wideband radar unit 103 are selectively used based on the distance to the object. However, for example, the narrowband radar unit 102 is usually used as another processing method. The broadband radar unit 103 can be used only when high resolution is required. As a result, use of the broadband radar unit 103 can be limited, and interference with other systems can be reduced.

  When the use of the broadband radar unit 103 may cause a problem of interference with other systems, it is possible to temporarily control so that only the narrowband radar unit 102 is used. Can be realized only by software processing of the arithmetic unit 101. Further, when the use of the narrowband radar unit 102 is expected to cause a problem of interference with other narrowband radars, the frequency band used by the narrowband radar unit 102 is divided into a plurality of usage bands in advance. Can be used.

  As an example, as shown in FIG. 5, when the bandwidth that can be used by the narrowband radar unit 102 is 200 MHz and the bandwidth of the narrowband signal is 20 MHz, the available bandwidth 200 MHz is divided into 10 parts. It is possible to use it separately from the usage band 20 to the tenth usage band 29. In this case, assuming that another narrowband system uses the first usage band 20 and the second usage band 21, the narrowband radar unit 102 is one of the third to tenth usage bands 22 to 29. By switching to, interference with other narrow band systems can be avoided.

  As described above, according to the combined mode radar device 100 of the present embodiment, the narrowband radar unit 102 capable of measuring a long distance and the wideband radar unit 103 capable of measuring a short distance with high accuracy are used in cooperation. Thus, it is possible to measure from a short distance to a long distance with high accuracy. In addition, the processing in the calculation unit 101 can control the narrowband radar unit 102 and the wideband radar unit 103 to easily avoid interference with other systems.

A configuration of a composite mode radar device according to another embodiment of the present invention will be described below with reference to FIG. FIG. 6 shows a detailed configuration of the composite mode radar apparatus 200 of the present embodiment.
In the combined mode radar device 200 of this embodiment, a VCO (Voltage Controlled Oscillator) 211 is used as a narrowband wave source. The narrowband radar unit 202 generates a narrowband signal whose frequency is modulated by the VCO 211 based on the signal from the triangular wave generator 212, amplifies the signal by the amplifier 213, and then a multiplexer when the switch 214 is on. 250. Various control parameters of the triangular wave generator 212 can be set from the calculation unit 201, and switching of the switch 214 is controlled by a trigger signal from the calculation unit 201.

  In addition, a BO (Burst Oscillator) 221 is used as a broadband impulse source, and when an impulse trigger is output from the calculation unit 201, a high-frequency broadband impulse signal is oscillated in the BO 221 for a period of about 1 nsec. The wideband impulse signal oscillated by the BO 221 is amplified by the amplifier 223 and then output to the multiplexer 250, where it is combined with the narrowband signal and sent to the antenna unit 260 as a transmission signal.

  The antenna unit 260 of the present embodiment is configured to include a transmission antenna 261 and a reception antenna 262, and an antenna duplexer is unnecessary. Since the transmission signal combined by the multiplexer 250 becomes a wideband signal, the transmission antenna 261 is made a wideband transmission antenna capable of transmitting a wideband signal correspondingly. Similarly, the receiving antenna 262 is an antenna that can receive each reflected wave of a narrowband signal and a wideband impulse signal.

  The received signal received by the receiving antenna 262 is demultiplexed by the demultiplexer 270 and then transmitted to the first filtering unit 231 and the second filtering unit 241. Further, the narrowband receiving unit 230 and the wideband receiving unit are transmitted. 240. In the first filtering unit 231, a received wave having a narrow band frequency is filtered from the received signal. In the narrowband receiving unit 230, the reception wave filtered by the first filtering unit 231 is amplified by the amplifier 232, mixed with the transmission signal by the mixer 233, and converted into a predetermined beat signal. The transmission signal mixed with the reception wave by the mixer 233 is demultiplexed from the directional coupler 215 of the narrowband signal generation unit 210.

  By filtering the mixed wave generated by the mixer 233 with an LPF (Low Pass Filter) 234, a beat signal having a beat frequency corresponding to the observed distance to the object can be acquired. The beat signal is amplified by an amplifier 235 and then transmitted to an S / H (Sample / Hold) circuit 237, where detection data by the narrowband radar unit 202 is acquired and output to the calculation unit 201.

  Similarly, the second filtering unit 241 also filters a received wave having a broadband frequency from the received signal. In the wideband receiving unit 240, the received wave filtered by the second filtering unit 241 is amplified by the amplifier 242 and then demultiplexed by the mixer 243 from the directional coupler 215 of the narrowband signal generating unit 210. Mixed with the transmitted signal. However, the mixing with the transmission signal in the mixer 243 is for down-conversion of the wideband signal, thereby down-converting to a frequency band close to the baseband. In this way, by down-converting a wideband signal, it is possible to use a low-priced LPF 244 and amplifier 245 that are relatively low-priced for low frequencies.

  By filtering the mixed wave generated by the mixer 243 with the LPF 244, it is possible to obtain a down-converted wideband received wave, which is amplified by the amplifier 245 and then input to the detector 246 to detect the impulse signal. Let it be done. The impulse signal detected by the detector 246 is transmitted to the S / H circuit 247, where detection data by the broadband radar unit 203 is acquired and output to the calculation unit 201.

  In the combined mode radar device 200 of this embodiment, FMCW is used as a narrowband signal. Radars using FMCW use radio waves whose frequencies are sequentially changed in time series, thereby making it possible to measure the distance to the object and the relative velocity. In the FMCW radar, the frequency increases when reflected by a distant object, and the frequency decreases when reflected by a nearby object. A distance and relative velocity measurement method using FMCW will be described with reference to FIG.

  In the FMCW radar, as shown in FIG. 7 (a), a transmission wave that is modulated in a triangular shape by increasing / decreasing the frequency in time series is used. The change width (bandwidth) of the frequency shown in FIG. 7A is as small as about 20 MHz, and it can be said that the signal used for the FMCW radar is a narrow-band signal. When such a signal is transmitted and reflected by an object separated by a distance L, the signal is received by the receiving antenna 262 with a time delay of a round trip distance of 2L. By mixing the received wave and the transmitted wave with the mixer 233, a signal having a beat frequency proportional to the distance L as shown in FIG. 7B can be extracted. Therefore, this beat signal is FFT-analyzed by the calculation unit 201 to detect the peak frequency.

A frequency fb corresponding to the distance can be obtained from the beat frequency fbu in the increasing section and the beat frequency fbd in the decreasing section shown in FIG.
[Equation 1]
fb = (| fbu | + | fbd |) / 2 (Formula 1)
When the object has a relative speed with respect to the radar apparatus, the frequency of the reflected wave is shifted by fd shown in FIG. 7 due to the Doppler effect.

  On the other hand, in the broadband radar unit 203, the broadband impulse signal oscillated by the BO 221 is detected with a time delay corresponding to the round-trip distance 2L to the observation object, and this is detected by the broadband receiving unit 240 and processed as detection data. Is processed by the arithmetic unit 201 to calculate the distance L.

  Also in this embodiment, by using the narrowband radar unit 202 and the wideband radar unit 203 in cooperation, it is possible to measure from a short distance to a long distance with high accuracy. It is possible to easily avoid interference with other systems by controlling the narrowband radar unit 202 and the broadband radar unit 203.

  In addition, the received signal input to the wideband receiving unit 240 is mixed with the narrowband signal generated by the narrowband signal generating unit 210 and down-converted to filter the wideband received wave. As the LPF 244 and the amplifier 245 for amplifying the LPF 244, it is possible to use a low-cost one corresponding to a low frequency band. The frequency-modulated narrowband signal is a sufficiently narrowband signal when viewed from the bandwidth of the wideband impulse signal, and does not cause a problem in the detection of the impulse.

  Furthermore, in the present embodiment, the antenna unit 260 is configured to include the transmission antenna 261 and the reception antenna 262 so that transmission and reception can be performed in parallel. Can be used at a higher level.

  Note that when the transmission antenna 261 and the reception antenna 262 are provided so that transmission and reception can be performed in parallel, in order to use a continuous wave such as FMCW for the transmission signal, the transmission antenna 261 and the reception antenna 262 Must be set apart to some extent. This is to prevent part of the continuous wave transmitted from the transmission antenna 261 from being directly received by the reception antenna 262 due to wraparound.

  If the transmitting antenna 261 and the receiving antenna 262 are installed close to each other, when the transmission signal is a continuous wave, a part of the transmitted wave is always received by the receiving antenna 262 due to wraparound, and the receiving circuit is saturated and cannot be measured. Become. In order to prevent this, in the present embodiment, the distance between the transmission antenna 261 and the reception antenna 262 is increased to some extent to achieve isolation. In the combined mode radar device 200 of the present embodiment, the narrowband signal is output from the narrowband signal generator 210 only during the period when the switch 214 is on, so that the receiving circuit is saturated. However, it is more preferable that the transmission antenna 261 and the reception antenna 262 be isolated.

  On the other hand, when an impulse signal is transmitted, since this signal is output at a predetermined interval, there is no problem that the receiving circuit is saturated. In the present embodiment, an impulse signal is used as a wideband signal, and the above-described problem does not occur in the wideband radar unit 203.

  A configuration of a composite mode radar apparatus according to still another embodiment of the present invention will be described below with reference to FIG. In the combined mode radar apparatus 300 of the present embodiment, the observation area by the narrowband radar unit 302 and the observation area by the wideband radar unit 303 are set to be different. An example of each observation region is shown in FIG.

  In FIG. 9, the observation region 31 by the narrow-band radar unit 302 is set to a narrow angle range and to a long distance, whereas the observation region 32 of the wide-band radar unit 303 is a region to a wide angle and a short distance. It is said. In the radar function using the broadband impulse signal by the broadband radar unit 303, it is possible to observe a short distance over a wide range, and therefore, the observation areas of the narrowband radar unit 302 and the broadband radar unit 303 are shown in FIG. It is preferable to set as follows.

  When the observation areas of the narrowband radar unit 302 and the broadband radar unit 303 are set to different areas as shown in FIG. 9, for example, the transmission range and the reception range are also different. Both those used for the unit 302 and those used for the broadband radar unit 303 are required.

  In this embodiment, as shown in FIG. 8, the antenna unit 360 is provided with a narrowband transmitting antenna 361, a wideband transmitting antenna 362, a narrowband receiving antenna 363, and a wideband receiving antenna 364. The band signal generator 310, the broadband signal generator 320, the narrowband receiver 330, and the broadband receiver 340 are connected.

  Next, the processing in the calculation unit 201 will be described using the composite mode radar device 200 as an example. In the calculation unit 201, a process related to the narrowband radar unit 202, a process related to the wideband radar unit 203, and a process that controls them are executed. As shown in FIG. 10, the NBR CPU 420, the WBR CPU 430, and the like, respectively. And the centralized CPU 410. FIG. 11 shows an operation state transition diagram in each CPU, and FIGS.

  In the overall CPU 410, an overall processing unit 411 that controls each process in the NBR (Narrow Band Radar) CPU 420 and the WBR (Wide Band Radar) CPU 430 is executed based on a command from the host system 40. In the operation state transition diagram of the overall CPU 410 shown in FIG. 11A, as the process of the overall processing unit 411, a trigger output for operating the narrowband radar unit 202 and the wideband radar unit 203 at a predetermined timing, and a predetermined timing In the identification processing for obtaining the determination result of the measurement data from the NBR CPU 420 and the WBR CPU 430 and determining the distance to the observation object, etc., and the upper system information for outputting the identification processing result according to the information request from the upper system 40 It shows that each process of output is performed.

  Further, the NBR CPU 420 executes an NBR processing unit 421 and an NBR control unit 422 that perform each process related to the narrowband radar unit 202 based on a request from the overall processing unit 411 and the like. In the operation state transition diagram of the NBR CPU 420 shown in FIG. 11B, the NBR processing unit 421 is activated by the activation of the NBR control unit 422 by the trigger from the overall processing unit 411 and the polling process from the overall processing unit 411. It shows that each process of outputting measurement data is performed. In the NBR control unit 422, the narrowband radar unit 202 is controlled.

  Further, the WBR CPU 430 executes a WBR processing unit 431 and a WBR control unit 432 that perform each process related to the wideband radar unit 203 based on a request from the overall processing unit 411 and the like. In the operation state transition diagram of the WBR CPU 430 shown in FIG. 11C, the processing of the WBR processing unit 431 is based on the activation of the WBR control unit 432 by the trigger from the overall processing unit 411 and the polling processing from the overall processing unit 411. It shows that each process of outputting measurement data is performed. The WBR control unit 432 controls the broadband radar unit 203.

  The arithmetic unit 201 is further provided with a RAMP generation circuit 433, a comparator 434, and an integrator 435 in order to sample the detection data from the wideband radar unit 203 and fetch the data into the WBR CPU 430.

  The processing flow of the overall processing unit 411 will be described with reference to the flowchart shown in FIG. The overall processing unit 411 initializes parameters and the like used for each of the above-described processes in step S11 immediately after the activation of the overall CPU 410, and then executes the processes after the next step S12 in a predetermined cycle. In step S12, it is determined whether or not there is an information request from the host system 40. If there is an information request, the process of the next step S13 is executed. If there is no information request, the process proceeds to step S14. .

  In step S13, in response to the information request from the host system 40, the result of the identification processing that has been performed so far is output. In the next step S14, it is determined whether or not it is a trigger output timing for operating the narrowband radar unit 202 and the wideband radar unit 203. If it is determined that the trigger output timing is reached, the process of the next step S15 is executed. On the other hand, if it is determined that it is not the trigger output timing, the process proceeds to step S16.

  In step S <b> 15, a trigger for operating the narrowband radar unit 202 and the broadband radar unit 203 is output to the NBR CPU 420 and the WBR CPU 430. In the next step S16, it is determined whether or not it is the timing for taking in the measurement data from the NBR CPU 420 and the WBR CPU 430. If it is determined as the data take-in timing, the processing after the next step S17 is executed. If it is determined that it is not the data capture timing, the processing is started from step S12 in the next cycle.

  In step S17, polling processing is performed on the NBR CPU 420 and the WBR CPU 430 to acquire measurement data from each, and in step S18, measurement data tracking processing is performed. Further, in step S19, an identification process for determining the distance to the observation object based on the result of the tracking process in step S18 is performed.

  Next, the processing flow of the NBR processing unit 421 will be described with reference to the flowcharts shown in FIGS. The NBR processing unit 421 initializes parameters and the like used for each of the above-described processes in step S21 immediately after the activation of the NBR CPU 420, and then executes the processes subsequent to step S22 at a predetermined cycle. In step S22, it is determined whether or not there is a data request from the overall processing unit 411. If there is a data request, the process of the next step S23 is executed. If there is no data request, the process proceeds to step S24. move on.

  In step S23, in response to the data request from the overall processing unit 411, the measurement data processed immediately before is output. In the next step S24, it is determined whether or not a trigger for operating the narrowband radar unit 202 has been input from the overall processing unit 411. If it is determined that the trigger has been input, the processing of the next step S25 is executed. On the other hand, if it is determined that the trigger is not input, the processing is started from step S22 in the next cycle. In step S25, the NBR control unit 422 is executed by the same NBR CPU 420, and measurement data is acquired from the NBR control unit 422 that has completed the execution.

  When requested to be executed by the NBR processing unit 421, the NBR control unit 422 outputs a transmission trigger to the switch 214 in order to output a narrowband signal from the narrowband signal generation unit 210 in step S26. In the next step S27, data sampling is performed from the S / H circuit 237. The sampling data is subjected to FFT analysis in step S28 to determine the beat frequency shown in FIG. 7, and in step S29, the beat frequency obtained by FFT analysis is determined. Measurement data such as distance is determined from the above.

  The processing flow of the WBR processing unit 431 will be described with reference to the flowcharts shown in FIGS. The WBR processing unit 431 initializes parameters and the like used for each of the above-described processes in step S31 immediately after the start of the WBR CPU 430, and then executes the processes after the next step S32 in a predetermined cycle. In step S32, it is determined whether or not there is a data request from the overall processing unit 411. If there is a data request, the process of the next step S33 is executed. If there is no data request, the process proceeds to step S34. move on.

  In step S33, in response to the data request from the overall processing unit 411, the measurement data processed immediately before is output. In the next step S34, it is determined whether or not a trigger for operating the broadband radar unit 203 is input from the overall processing unit 411. If it is determined that the trigger is input, the process of the next step S35 is executed. On the other hand, if it is determined that the trigger is not input, the processing is started from step S32 in the next cycle. In step S35, the WBR control unit 432 is executed by the same WBR CPU 430, and measurement data is acquired from the WBR control unit 432 that has completed the execution.

  When requested to execute from the WBR processing unit 431, the WBR control unit 432 outputs an impulse trigger to the BO 221 in step S36. In the next step S37, data sampling is performed by the S / H circuit 247 at the timing determined by the RAMP generation circuit 433 and the comparator 434. In step S38, the sampling data is integrated by the integrator 435 for a predetermined number of impulses. From the integrated value, measurement data such as distance is determined in step S39.

  In the processing in step S37, the ramp wave 433a generated by the RAMP generation circuit 433 shown in FIG. 10A and the threshold value 432a set by the WBR control unit 432 are compared by the comparator 434, and the ramp wave 433a is compared. When the value exceeds the threshold value 432a, a trigger is output to the S / H circuit 247. When this trigger is input, the S / H circuit 247 latches the amplitude of the impulse input from the detector 246 and outputs it to the integrator 435.

  The RAMP generation circuit 433 generates a ramp wave 433a as shown in FIG. 10B by charging with a constant current source, and outputs it to the comparator 434. The ramp wave 433a is configured to be repeatedly generated at a predetermined cycle. By configuring the S / H circuit 247 to latch the input data using the ramp wave 433a, it is possible to adjust the data sampling timing only by changing the threshold value 432a.

  Note that the description in the present embodiment shows an example of the composite mode radar apparatus according to the present invention, and the present invention is not limited to this. The detailed configuration and detailed operation of the combined mode radar device in the present embodiment can be changed as appropriate without departing from the spirit of the present invention.

It is a figure which shows the block diagram of the compound mode radar apparatus which concerns on embodiment of this invention. It is a figure which shows an example of the frequency band used with the compound mode radar apparatus of this invention. It is a figure which shows the basic operation | movement of a narrowband radar part and a wideband radar part. It is a flowchart which shows one Example which performs ranging using basic operation | movement. It is a figure which shows the form which divides | segments and can utilize the bandwidth which can be utilized in a narrow-band radar part. It is a figure which shows the block diagram of the composite mode radar apparatus which concerns on another embodiment of this invention. It is a figure explaining the measuring method of distance and relative velocity using FMCW. It is a figure which shows the block diagram of the compound mode radar apparatus which concerns on another embodiment of this invention. It is a figure which shows the example from which the observation area | region by a narrowband radar part differs from the observation area | region by a broadband radar part. It is a figure which shows the structure of a calculating part. FIG. 5 is an operation state transition diagram of a central CPU, an NBR CPU, and a WBR CPU. It is a figure which shows the flow of a process in CPU for control. It is a figure which shows the flow of a process in CPU for NBR and CPU for WBR.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11, 13 Narrow-band radar band 12, 14 Wide-band radar band 20-29 Utilization band 31, 32 Observation area 40 Upper system 100, 200, 300 Compound mode radar apparatus 101 Arithmetic unit 102, 202, 302 Narrow-band radar unit 103 , 203, 303 Broadband radar unit 110, 210, 310 Narrowband signal generation unit 111 Narrowband wave source 120, 220, 320 Wideband signal generation unit 121 Wideband impulse source 130, 230, 330 Narrowband reception unit 131, 231 First filter Wave part 132 Narrow band receiving circuit 140, 240, 340 Wide band receiving part 141, 241 Second filtering part 142 Wide band receiving circuit 150, 250 Multiplexer 160, 260 Antenna part 161, 261, 262 Antenna 162 Antenna duplexer 170 270 demultiplexer 211 VCO
212 Triangular Wave Generator 213, 223, 232, 235, 242, 245 Amplifier 214 Switch 215 Directional Coupler 221 BO
233 Mixer 237, 247 S / H circuit 246 Detector 410 General-purpose CPU
411 General processing unit 420 CPU for NBR
421 NBR processing unit 422 NBR control unit 430 CPU for WBR
431 WBR processing unit 432 WBR control unit 433 RAMP generation circuit 434 comparator 435 integrator

Claims (12)

A narrowband signal generator for generating a narrowband signal having a first frequency as a center frequency;
A wideband signal generator for generating a wideband signal having a second frequency different from the first frequency as a center frequency;
An antenna unit that receives and transmits the narrowband signal and the broadband signal from the narrowband signal generator and the broadband signal generator, respectively, and receives the reflected wave of the narrowband signal and the broadband signal;
A first filtering unit that receives a received signal from the antenna unit and filters the received wave of the narrowband signal;
A second filtering unit that receives a received signal from the antenna unit and filters the received wave of the broadband signal;
A narrowband receiving unit that receives a reception wave filtered by the first filtering unit and detects a reflected wave of the narrowband signal;
A broadband receiving unit that receives a received wave filtered by the second filtering unit and detects a reflected wave of the broadband signal;
A calculation unit that inputs each detection data from the narrowband reception unit and the wideband reception unit and determines position data; and
The composite mode radar device, wherein the first frequency and the second frequency are set to be separated so that the frequency band of the narrowband signal and the frequency band of the wideband signal are separated. The wideband receiving unit receives the narrowband signal from the narrowband signal generation unit and mixes it with the received wave of the wideband signal, thereby down-converting the frequency band of the received wave. The composite mode radar device according to 1. The narrowband receiving unit receives the narrowband signal from the narrowband signal generation unit and mixes it with the received wave of the narrowband signal, thereby down-converting the frequency band of the received wave to a baseband. The composite mode radar device according to claim 1, wherein The narrowband signal generation unit includes a continuous wave generation source that generates a continuous wave of the narrowband signal, and a switch that performs a switching operation to output or cut off the continuous wave,
The composite mode radar device according to any one of claims 1 to 3, wherein the switch is controlled to perform the switching operation based on a control signal from the arithmetic unit. 2. The narrowband signal generation unit is controlled by the arithmetic unit so as to generate the narrowband signal in any one band in which a frequency band to be used is divided into two or more. The composite mode radar device according to claim 3. The broadband signal generator includes a broadband impulse source that generates the broadband impulse signal,
The combined mode radar according to any one of claims 1 to 3, wherein the broadband impulse source is controlled to generate the impulse signal based on a control signal from the arithmetic unit. apparatus. The calculation unit outputs the control signal to at least one of the narrowband signal generation unit and the wideband signal generation unit based on the determination result of the position data. A combined mode radar device according to claim 1. The antenna unit includes a transmission / reception shared antenna that can selectively perform transmission and reception, and an antenna duplexer that switches the transmission / reception shared antenna to transmission or reception by control from the arithmetic unit,
When the transmission / reception shared antenna is switched for transmission, the narrowband signal and the wideband signal are mixed and transmitted,
2. When the transmission / reception shared antenna is switched for reception, the received signal is demultiplexed into the first filtering unit and the second filtering unit and output. The composite mode radar device according to claim 3. The antenna unit includes a transmitting antenna and a receiving antenna,
The transmitting antenna mixes and transmits the narrowband signal and the wideband signal,
The said receiving antenna demultiplexes and outputs the said received signal to said 1st filtering part and said 2nd filtering part. A combined mode radar device according to claim 1. The antenna unit includes a narrowband transmitting antenna, a wideband transmitting antenna, a narrowband receiving antenna, and a wideband receiving antenna.
The narrowband transmitting antenna inputs the narrowband signal and transmits it in a predetermined angular range,
The wideband transmitting antenna receives the wideband signal and transmits it in a wide angle range wider than the predetermined angle range,
The narrowband receiving antenna outputs the received signal received from the predetermined angle range to the first filtering unit,
4. The composite mode according to claim 1, wherein the wideband receiving antenna outputs the received signal received from the wide angle range to the second filtering unit. 5. Radar device. 4. The combined mode radar device according to claim 1, wherein the first center frequency and the second center frequency are any of 22 GHz and 29 GHz. 5. The composite mode radar apparatus according to any one of claims 1 to 3, wherein the wideband signal is a UWB signal having a bandwidth of at least 450 MHz.

Images