JP2009294071A - Radar device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a DBF-system radar device, capable of preventing influence of phase/amplitude changes resulting from temperature/changes due to aging. <P>SOLUTION: A signal processing means 101 has a phase/amplitude detection means 60 for detecting the phase/amplitude of a transmission signal of each channel obtained, when a switching means 50 is closed onto a splitter 7 side; a storage means 70 for storing data detected by the detection means 60; a detection-period control means 121 for controlling a data detection period of the detection means 60; a difference-value detection means 80 for finding a change component between new data, detected within a period set by the control means 121 and data stored in the storage means 70; a storage means 90 for storing the change component acquired by the detection means 80 up to the next change-component detection period; and a received data-signal processing means 111 for correcting phase and amplitude errors of each receiving system, on the basis of the phase/amplitude data stored in the storage means 70 and 90. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a radar device for receiving reflected radio waves reflected by a target by a plurality of receiving antennas and measuring a relative distance, speed, and angle with the target. For example, the radar device is mounted on an automobile and is a target. A vehicle-mounted radar device that receives reflected radio waves reflected by surrounding vehicles with multiple receiving antennas, measures relative distance, speed, angle, etc. with the target, and is useful for inter-vehicle distance control and collision damage reduction. Is.

In general, in a radar device, the target angle is obtained by scanning an antenna beam (radio wave emitted from a transmitting antenna) that is narrowed to a desired width and detecting the reception angle of the radio wave reflected by the target. Can do.
The beam scanning method can be broadly divided into a mechanical scanning method and an electronic scanning method, and digital beam forming (hereinafter also abbreviated as DBF) is known as one of the electronic scanning methods.
DBF (Digital Beam Forming) is a radio signal that is transmitted from a transmitting antenna and received by a plurality of receiving antennas at the same time and is reflected from the target, and various antenna patterns are converted into digital signals using the phase difference between the received signals. It is formed by processing.
According to the DBF, there is no need to drive the antenna as in the mechanical scanning system, so that a drive mechanism is not required. Therefore, the DBF has a feature that it is resistant to vibration and can be reduced in size and weight. It is considered as one of the most suitable methods.

As this type of radar apparatus, an apparatus as shown in FIG. 7 is known.
In FIG. 7, for the sake of simplicity, one transmission system is used, but an in-vehicle radio wave radar device having a plurality of transmission systems is also known.
In FIG. 7, 1 is a target (for example, a surrounding vehicle as an object to be detected), 500 is a conventional radar device, 2 is a voltage controlled oscillator (VCO), 3 is a distributor, 4 is a transmission amplifier, Reference numeral 5 denotes a transmission antenna.
Reference numeral 10 denotes a receiving antenna unit, 20 denotes a mixer unit, 30 denotes a receiving amplifier unit, 40 denotes an A / D (analog / digital) converter unit, and 100 denotes a signal processing unit.
The reception antenna unit 10 to the A / D converter unit 40 are configured by a plurality of reception channels (systems). The reception antenna unit 10 includes a plurality of reception antennas and a mixer unit 20 corresponding to the plurality of reception channels. Includes a plurality of mixers, the reception amplifier unit 30 includes a plurality of reception amplifiers, and the A / D converter unit 40 includes a plurality of A / D converters.

The operation of the conventional radar apparatus shown in FIG. 7 will be described.
The signal processing unit 100 controls the voltage controlled oscillator (VCO) 2 to determine an arbitrary transmission frequency, and the radio wave amplified by the transmission amplifier 4 is transmitted from the transmission antenna 5 to the target 1.
The radio wave reflected by the target is received by each receiving antenna of the receiving antenna unit 10, down-converted by the mixer unit 20, amplified by the receiving amplifier unit 30, and converted into digital data by the A / D converter unit 40, The signal converted into digital data is input to the signal processing unit 100.

Then, the signal processing unit 100 performs DBF processing based on the phase / amplitude data for each reception system (for each reception channel) from each reception antenna to the A / D converter, so that the relative distance R to the target and the relative measure are obtained. V and relative angle θ are obtained.
At that time, it is well known that a change in phase and amplitude from the initial adjustment for each receiving system due to a temperature change and a secular change affects the accuracy of the antenna beam.
As for a radar apparatus that detects and corrects a phase / amplitude change for each receiving system after the assembly of the radar, a proposal as described in Patent Document 1 (Japanese Patent Laid-Open No. 10-332811) has been made.

Japanese Patent Laid-Open No. 2004-133867 discloses that in a radar device that receives reflected echoes from a target by a plurality of reception systems and detects a target based on the plurality of reception results, the plurality of reception systems respectively emit signals radiated into the space. An antenna unit for receiving a signal and outputting the received signal as a received signal, a phase detecting unit for detecting a phase of the received signal from the antenna unit, a reference data storage unit for storing predetermined reference detection data, and a predetermined monitor signal for the antenna unit Is received, based on the phase detection result of the received signal and the reference detection data stored in the reference data storage means, at least one of the phase fluctuation component and the amplitude fluctuation component included in the reception signal Fluctuation component detecting means for detecting the fluctuation component and fluctuation component correction means for correcting the fluctuation component detected by the fluctuation component detection means with respect to the phase detection result of the phase detection means Radar system "has been proposed was.
According to this proposal, it is possible to detect the phase / amplitude change of the entire receiving system including the receiving antenna, which is a very desirable proposal for correcting the change of the phase / amplitude.
JP-A-10-332811 (paragraph 0022)

However, in order to realize this, a transmission antenna (which is a monitor antenna in Patent Document 1) for inputting a test signal for monitoring to the reception antenna is required.
Therefore, in an in-vehicle radar device that is particularly required to be miniaturized, it is not desirable in terms of the size of the device to have an extra antenna mechanism (that is, a monitor antenna mechanism).
In addition, when receiving a test signal for monitoring, external radio waves (radio waves outside the test signal) may be received at the same time, which may cause errors in correcting the phase difference and amplitude difference. there were.

Therefore, a means for efficiently detecting and correcting a phase / amplitude change for each receiving system due to a temperature change and a secular change has been demanded as a vehicle-mounted radar apparatus without causing a significant mechanical effect.
In addition, by measuring the temperature characteristics of each receiving system in advance and providing a correction map, it is possible to correct changes in phase and amplitude with respect to temperature changes. This is not preferable from the viewpoint of the characteristics, and there is a problem that it is not possible to correct the temperature characteristic variation for each receiving system due to aging.

If the size is about the same as a general on-vehicle radar device, it can be seen that the expansion and contraction due to temperature change and secular change of the transmission / reception antenna unit is uniform.
Further, the interval between the receiving antennas of the receiving antenna unit 10 is arranged with a size of about ½ wavelength of the transmission frequency (for example, in the case of 76 GHz, the wavelength λ is about 4 mm). It can be expected that the amount of change in the interval (that is, phase) is small, and the influence on each receiving system is uniform.

On the other hand, the amount of change in phase and amplitude due to temperature changes and secular changes of the electronic components that make up the radar device does not depend on the size of the radar device, and generally depends on the variation of individual components. For each receiving system, it appears as variations in the amount of change in phase and amplitude.
Further, considering the electronic components of each receiving system (electronic components from the mixer unit 20 to the A / D converter unit 40), the delay time (usually on the order of nsec) required for the reception signal to pass is the receiving antenna interval (for example, 76 GHz). In the case of λ / 2, it is very large with respect to the change amount of about 7 psec), and the occurrence of variations in this causes disturbance in the phase information of each received signal, and consequently affects the accuracy of beam synthesis by calculation.

  The present invention has been made in order to solve the above-described problems, and obtains the arrival direction of a reflected wave from the relationship between phases and amplitudes between received data obtained from a plurality of receiving channels, and provides a target. A DBF radar device that detects a direction and cancels the influence of a phase / amplitude change of an electronic component due to temperature change / aging change, and can obtain an accurate antenna beam. The purpose is to provide.

A radar apparatus according to the present invention includes: a transmission amplifier configured to amplify a transmission signal output from a voltage-controlled oscillator; a transmission system configured to transmit a transmission signal amplified by the transmission amplifier to a target; A plurality of receiving antennas for receiving reflected reflected signals; a plurality of mixers for frequency down-converting the received signals obtained by the plurality of receiving antennas; and a plurality of receiving amplifiers for amplifying the outputs of the plurality of mixers, respectively. A plurality of A / D converters for converting the outputs of the plurality of reception amplifiers into digital data, respectively, and based on the reception data obtained for each of the plurality of reception antennas. In a radar device that detects a target,
A first distributor that distributes a transmission signal output from the voltage controlled oscillator to the transmission amplifier side and the reception system side, and a transmission signal output from the transmission amplifier is switched to the transmission antenna 5 side or the reception system side. Possible first switching means, a second distributor for distributing a transmission signal from the transmission amplifier to a plurality of channels of the reception system when the first switching means is switched to the reception system side, and A second switching means capable of switching a reception signal from the reception antenna and a transmission signal from the second distributor for each channel of the reception system and allowing the signals to be input to the plurality of mixers; A third distributor that distributes the transmission signal distributed to the reception system side by one distributor to each of the plurality of mixers; and the plurality of A / D converters for each channel of the reception system. And a signal processing means for correcting the reception data based on the transmission signal from the received signal and the second divider outputs from vessel,
The signal processing means includes a phase / amplitude detection means for detecting a phase / amplitude of a transmission signal for each channel obtained when the second switching means is switched to the second distributor, and the phase / amplitude detection Set by a first storage means for storing phase / amplitude data detected by the means, a detection period control means for controlling a period during which the phase / amplitude detection means detects phase / amplitude data, and a detection period control means Difference value detection means for obtaining a change between the new phase / amplitude data detected in the period and the phase / amplitude data stored in the first storage means, and the change obtained by the difference value detection means Second storage means for storing the minutes until the next change detection period, and the phase for each reception system based on the phase and amplitude data stored in the first storage means and the second storage means, Amplitude error In which and a received data signal processing means is a correction for correcting unit.

  According to the present invention, the phase / amplitude data in the first detection period (for example, the assembly adjustment period) stored for each reception system and the phase / amplitude data newly obtained in the second detection period are stored. By detecting the change, it is possible to correct the phase and amplitude errors for each receiving system caused by the radar apparatus itself, and to realize highly accurate antenna beam formation.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In the drawings, the same reference numerals indicate the same or equivalent ones.
Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of a radar apparatus according to the first embodiment.
In FIG. 1, 2 is a VCO, 3 is a first distributor, 4 is a transmission amplifier, 5 is a transmission antenna, 6 is a transmission side switch (first switching means), 7 is a second distributor, and 8 is An amplifier, 9 is a third distributor, and 10 is a receiving antenna unit.
Also, 20 is a mixer section, 30 is a receiving amplifier section, 40 is an A / D converter section, 50 is a receiving side switch section (second switching means), and 60 is a phase / amplitude detecting section (phase / amplitude detecting means). , 70 is a first storage unit (first storage unit), 80 is a difference value detection unit (difference value detection unit), and 90 is a second storage unit (second storage unit).
Reference numeral 101 denotes a signal processing unit (signal processing unit), 111 denotes a reception data signal processing unit (reception data signal processing unit) having a DBF signal processing function, 121 denotes a detection period control unit, and 501 denotes a radar according to the first embodiment. Device.
In FIG. 1, “Tx” represents transmission (Transmit exchange), and “Rx” represents reception.

First, the transmission procedure in the normal radar operation will be described.
A desired transmission frequency is determined by controlling a voltage controlled oscillator (VCO) 2 from the signal processing unit 101, and then from the voltage controlled oscillator (VCO) 2 through the first distributor 3 and the transmission amplifier 4. The transmission signal is input to the transmission side switch (first switching means) 6.
By closing the transmission side switch 6 on the transmission antenna 5 side (that is, switching the contact point of the transmission side switch 6 to the reception side in the state shown in FIG. 1), the radio wave is transmitted from the transmission antenna 5 to the target 1 (not shown). Sent.

Next, the reception procedure in the normal radar operation will be described.
Note that FIG. 1 shows a case where the reception channels are four channels Rx1 to Rx4 for the sake of simplicity, but the reception channels are not limited to four channels.
A radio wave reflected from a target 1 (not shown) that is an object to be detected is input as a received radio wave to each of the receiving antennas 11 to 14 of the receiving antenna unit 10.
The reception-side switch unit (second switching means) 50 is configured with switches 51 to 54 corresponding to the respective reception channels, and each switch 51 to 54 of the reception-side switch unit 50 is connected to the reception antenna 10 side. (Ie, switching the contacts of each switch of the receiving side switching means 50 to the state shown in FIG. 1), the received signals received by the receiving antennas 11 to 14 of the receiving antenna unit 10 are mixed with the mixer unit 20. Are converted by the A / D converters 41 to 44 of the A / D converter unit 40 through the reception amplifiers 31 to 34 of the reception amplifier unit 30.

The transmission side switch (first switching unit) 6 and the reception side switch unit (second switching unit) 50 are switched according to an instruction from the detection period control unit 121.
First, the phase / amplitude data of each system at the time of initial adjustment (first detection period) is stored using the detection period control means 121, and each system in the second detection period after the radar apparatus is operated. The phase / amplitude data is stored.
The detection period set by the detection period control means 121 may be switched manually or automatically by a control unit inside the radar apparatus.
Based on the digital data converted by the A / D converter unit 40, the signal processing unit 101 calculates the phase and amplitude for each channel (four channels Rx1 to Rx4) of the receiving antenna unit 10, Based on the information, the received data signal processing unit 111 performs DBF signal processing to form an antenna beam.

As described above, the radar apparatus 501 according to the present embodiment obtains the arrival direction of the reflected wave by DBF signal processing from the relationship between the phase and amplitude between reception data obtained from a plurality of reception channels, and the direction of the detected object. It is a radar system that detects
In the initial assembly state of the radar apparatus 501, even if the received radio wave is input to each of the receiving antennas 11 to 14 of the receiving antenna unit 10 evenly so that a phase difference does not occur between the channels, the component variations for each receiving channel There is a phase difference and an amplitude difference for each reception channel.

Therefore, normally, at the time of assembly adjustment, the phase and amplitude data for each reception system are measured by the phase / amplitude detectors 61 to 64 of the phase / amplitude detection unit 60, and the storage units 71 to 71 of the first storage unit 70 are measured. 74 is stored.
In the normal radar operation, the reception data signal processing unit 111 receives each reception caused by the radar apparatus while referring to the phase and amplitude data for each reception system stored in each storage means (memory) 71 to 74. Correct antenna beam formation is realized by correcting the phase difference and amplitude difference between systems.

Hereinafter, a method of correcting a change in phase / amplitude accompanying a change in temperature and aged over time after the radar apparatus 501 is attached to a vehicle will be described.
First, a detection period (detection time point) for detecting a change in phase and amplitude is provided, and this detection period is controlled by the detection period control means 121.
Only in this period (that is, a period in which a change in phase / amplitude is detected) by the signal processing unit 101, the transmission side switch ( The first switching means) 6 is operated.
Next, when the signal processing unit 101 distributes the signal by the distributor 7, the contacts of the switching units 51 to 54 of the reception side switching unit 50 are connected so that the signals are input to the mixers 21 to 24 of the mixer unit 20. Perform switching operation.
This operation order may be reversed or simultaneous according to the convenience of each circuit configuration.

Next, a desired transmission frequency is determined by operating the VCO 2 from the signal processing unit 101, and the loop of the loop (VCO 2 to distributor 3 to transmission amplifier 4 to transmission side switch 6 to first switch realized by the above-described operation. Phase / amplitude detection unit (phase) for each receiving system via 2 distributors 7 to reception side switching unit 50 to mixer unit 20 to reception amplifier unit 30 to A / D converter unit 40). (Amplitude detection means) 60.
Even if the transmission side switch 6 is not provided and a power is supplied (inputs a signal) from the transmission amplifier 4 to both the transmission antenna 5 and the mixer unit 20 using a distributor, the same observation (ie, for each reception system) (Calculation of phase and amplitude) is possible.

However, in this case, there is a problem that power during normal radar operation supplied to the transmission antenna 5 is attenuated by power distribution, and it is necessary to increase the gain of the transmission amplifier 4 or add a new amplifier. Therefore, it is desirable to supply power to either the transmission antenna 5 provided with the transmission side switch 6 or the mixer unit 20 side.
In addition, a folding signal (that is, a signal input to the reception system via the VCO 2 -distributor 3 -transmission amplifier 4 -transmission side switch 6 -distributor 7) input to each reception system is output from the transmission amplifier 4. Instead, it is possible to observe changes for each receiving system as a reference signal source provided separately.
However, in actual radar operation, the transmission system via the transmission amplifier 4 is also affected by temperature and aging.
Therefore, when observing the change in phase / amplitude, it is desirable to use a system that conforms to the actual radar operation including this (that is, the transmission system via the transmission amplifier 4).
This is the same when there are a plurality of transmission systems.

Next, phase / amplitude data for each reception system calculated by the phase / amplitude detectors 61 to 64 of the phase / amplitude detector 60 and the memories 71 to 74 of the first storage unit 70 are stored. Based on the phase / amplitude data at the time of initial adjustment for each reception system, the difference detectors 81 to 84 of the difference detector 80 change amounts for each reception system (that is, changes in phase / amplitude). Ask for.
The amount of change for each reception system obtained here is stored in each of the memories 91 to 94 of the second storage means 90.
The reception data signal processing unit 111 is stored in each of the memories 71 to 74 of the first storage unit 70 in the phase and amplitude differences during assembly adjustment stored for each reception system in the DBF processing in the normal radar operation. Data) and the newly determined change amount (that is, the change amount stored in each of the memories 91 to 94 of the second storage unit 90), for each reception system caused by the radar device itself. Thus, it is possible to realize a highly accurate antenna beam formation.

As described above, the radar apparatus according to the present embodiment includes the transmission amplifier 4 that amplifies the transmission signal output from the voltage-controlled oscillator 2 and the transmission antenna that emits the transmission signal amplified by the transmission amplifier 4 to the target 1. 5, a plurality of receiving antennas 11 to 14 that receive the reflected signal reflected by the target 1, and a plurality of mixers 21 to 24 that down-convert the received signals obtained by the plurality of receiving antennas, respectively. The plurality of reception amplifiers 31 to 34 for amplifying the outputs of the plurality of mixers 21 to 24, respectively, and the plurality of A / D converters 41 to 44 for converting the outputs of the plurality of reception amplifiers 31 to 34 to digital data, respectively. A radar system that detects a target 1 based on received data obtained for each of a plurality of receiving antennas,
The first distributor 3 that distributes the transmission signal output from the voltage controlled oscillator 2 to the transmission amplifier 4 side and the reception system side, and the transmission signal output from the transmission amplifier 4 can be switched to the transmission antenna 5 side or the reception system side. First switching means 6 and a second distributor 7 for distributing a transmission signal from the transmission amplifier 4 to a plurality of channels of the reception system when the first switching means 6 is switched to the reception system side, Second switching means capable of switching the reception signal from the reception antennas 11 to 14 and the transmission signal from the second distributor 7 for each channel of the reception system and inputting them to the plurality of mixers 21 to 24, respectively. 50, a third distributor 9 that distributes the transmission signal distributed to the reception system side by the first distributor 3 to the plurality of mixers 21 to 24, and a plurality of A / S for each channel of the reception system. D converter 41 And a signal processing unit 101 for correcting the reception data based on the transmission signal from the received signal and the second distributor 7 is output from the 44,
The signal processing unit 101 includes a phase / amplitude detection unit that detects a phase / amplitude of a transmission signal for each channel obtained when the second switching unit 50 is switched to the second distributor 7 side, and a phase / amplitude detection unit. First storage means 70 for storing phase / amplitude data detected by 60, detection period control means 121 for controlling a period during which phase / amplitude detection means 60 detects phase / amplitude data, and detection period control means 121. A difference value detection means 80 for obtaining a change between the new phase / amplitude data detected in the set period and the phase / amplitude data stored in the first storage means 70, and a difference value detection output means 80 Based on the second storage means 90 for storing the obtained change amount until the next change detection period, and the phase / amplitude data stored in the first storage means 70 and the second storage means 90. It strains each phase, and a received data signal processing unit 111 is a correction means for correcting the amplitude error.

  Therefore, the phase / amplitude data in the first detection period (for example, the assembly adjustment period) stored for each reception system and the change in the phase / amplitude data newly obtained in the second detection period are detected. By doing so, it is possible to correct the phase and amplitude errors for each receiving system caused by the radar apparatus itself, and to realize highly accurate antenna beam formation.

Embodiment 2. FIG.
FIG. 2 is a schematic diagram for explaining a characteristic configuration of the radar apparatus according to the second embodiment.
As shown in FIG. 2, the radar apparatus according to the present embodiment is provided with an attenuator 301 between the first switching means 6 and the second distributor 7 in FIG. 1 showing the configuration of the first embodiment. It is characterized by that.
Reference numeral 502 denotes a radar apparatus according to the present embodiment.
It is known that the strength of radio waves is attenuated in inverse proportion to the square of the distance (the strength of the radio waves is 1/4 when the distance is doubled).

Therefore, when considered in a vehicle-mounted radar device, the power transmitted from the transmission amplifier 5 is much less than the power of the radio wave reflected from the detected object (that is, the target) and received by the receiving antenna unit 10. Generally, it is large.
Conversely, it can be seen that the receiving system has a circuit configuration that assumes this.
Therefore, when the return path from the transmission system circuit to the reception system circuit is configured, even if the transmission power is divided into four equal parts by the second distributor 7, the mixer unit 20, the reception amplifier unit 30, and the A / D converter There is a possibility that phase saturation and amplitude data cannot be acquired due to circuit saturation exceeding the dynamic range of the receiving system circuit composed of the unit 40.
Therefore, in the present embodiment, by providing an attenuator 301 having an appropriate attenuation amount (predetermined attenuation amount) between the first switching means 6 and the second distributor 7, The correction means for preventing the dynamic range from being exceeded can be realized.

Embodiment 3 FIG.
FIG. 3 is a diagram illustrating a configuration of the signal processing unit 103 of the in-vehicle radio wave radar device according to the third embodiment.
In the first embodiment described above, if the amount of change in the phase and amplitude data for each reception system obtained by the difference value detection means 80 is too large, it is considered that one of the transmission / reception systems of the radar apparatus has failed. I can do it.
The CPU 131 is a part of the received data signal processing means described above, and a predetermined threshold value is input from the CPU 131 to each comparator of the comparator unit (comparing means) 310.
In the present embodiment, the CPU 131 monitors the result of comparing the predetermined threshold value (design allowable value) set by the CPU 131 with the calculated value of the difference value detection means 80 by each comparator G of the comparator unit 310. When it is determined that the amount of change exceeds the threshold, the CPU 131 notifies the vehicle system 600 through the communication unit 132 that the radar device is in a circuit failure state.
Further, the object to be compared by the comparator unit 310 may be the value of the second storage unit 90 shown in FIG. 1 in which the calculation data is stored instead of the difference value detection unit 80.

Here, the reason why the temperature measuring means 133 is provided will be described.
The phase / amplitude information (phase / amplitude data) detected by the phase / amplitude detection means 60 varies with temperature changes.
For example, when performing failure detection at high temperatures, if you try to make a determination based on the difference from normal temperature data (stored data during initial adjustment), a threshold (determination value) that takes into account the amount of phase / amplitude change due to temperature ) Is prepared, and the determination accuracy deteriorates.
Moreover, if the amount of change in phase / amplitude due to temperature is not taken into account, there is a possibility that a failure is determined only by the change due to temperature.
Therefore, by storing a typical (average) amount of change in phase / amplitude due to temperature in the CPU 131, the temperature change based on the temperature value obtained from the temperature measuring means 133 is stored. By subtracting the quantity representative value, the accuracy can be increased or erroneous determination can be prevented.

  As described above, the signal processing unit 103 of the radar apparatus according to the present embodiment includes the comparison unit 310 that compares the difference value detected by the difference value detection and output unit 80 with a preset threshold value, and exceeds the threshold value. When there is a change, the communication unit 132 determines that a failure has occurred and notifies the vehicle system 600 on which the radar device is mounted that the radar device is defective.

Embodiment 4 FIG.
FIG. 4 is a block diagram showing a configuration of a radar apparatus according to the fourth embodiment.
In the first embodiment described above, for example, the phase and amplitude data measured at the time of initial adjustment are stored in the first storage means 70, and the change amount data measured at the time of measuring the change amount of the phase / amplitude data is stored in the second storage. The means 90 is configured to be stored.
However, the data required for DBF processing during normal radar operation is only the relative error (shift amount) between the receiving systems.
Therefore, except for the case where data at the time of initial adjustment as shown in the first embodiment is required, it is not necessary to provide the second storage means 90 and the difference detection means 80 shown in FIG.

  Therefore, in the present embodiment, the phase and amplitude data for each reception system obtained at the time of new change measurement (new change detection period) is re-stored (overwritten) in the first storage means 70 to receive data. In the DBF processing in the normal radar operation, the signal processing unit 141 refers to the latest phase and amplitude data stored in the first storage unit 70, thereby causing the phase for each reception system due to the radar device itself, Amplitude error is corrected to realize highly accurate antenna beam formation.

As shown in FIG. 4, the radar apparatus according to the present embodiment transmits a transmission amplifier 4 that amplifies the transmission signal output from the voltage control transmitter 2 and transmits the transmission signal amplified by the transmission amplifier 4 to the target 1. A transmission system including the antenna 5, a plurality of reception antennas 11 to 14 that receive the reflected signal reflected by the target 1, and a plurality of mixers 21 to 24 that down-convert the reception signals obtained by the plurality of reception antennas, respectively. A plurality of reception amplifiers 31 to 34 for amplifying the outputs of the plurality of mixers 21 to 24, respectively, and a plurality of A / D converters 41 to 44 for converting the outputs of the plurality of reception amplifiers 31 to 34 to digital data, respectively. A radar system that detects a target 1 based on reception data obtained for each of a plurality of receiving antennas,
The first distributor 3 that distributes the transmission signal output from the voltage controlled oscillator 2 to the transmission amplifier 4 side and the reception system side, and the transmission signal output from the transmission amplifier 4 to the transmission antenna 5 side or the reception system side A first switching means 6 that can be switched to the first switching means 6 and a second distributor 7 that distributes a transmission signal from the transmission amplifier 4 to a plurality of channels of the receiving system when the first switching means 6 is switched to the receiving system side. The second switching that can switch the reception signal from the reception antennas 11 to 14 and the transmission signal from the second distributor 7 for each channel of the reception system and input the signals to the plurality of mixers 21 to 24, respectively. Means 50, a third distributor 9 for distributing the transmission signal distributed to the reception system side by the first distributor 3 to the plurality of mixers 21 to 24, and a plurality of channels for each channel of the reception system. A / D converter 4 And a signal processing unit 104 for correcting the reception data based on the transmission signal from the received signal and the second distributor 7 output from to 44,
The signal processing means 104 includes a phase / amplitude detection means 60 for detecting the phase / amplitude of the transmission signal for each channel obtained when the second switching means 50 is switched to the second distributor 7 side, and a phase / amplitude detection. A first storage means 70 for storing phase / amplitude data for each channel detected by the means 60; a detection period control means 121 for controlling a period during which the first storage means 70 detects phase / amplitude data; Received data signal processing means 141 for correcting a phase / amplitude error for each reception system based on the change in phase / amplitude data stored in the storage means 70.

Embodiment 5 FIG.
FIG. 5 is a timing chart for explaining the operation of the radar apparatus according to the fifth embodiment.
5A shows the timing of turning on the power supply (ignition SW), FIG. 5B shows the timing of vehicle start (system start), and FIG. 5C shows the correction data acquisition period.
In the present embodiment, the periodic detection period of the phase and amplitude data change amount for each reception system described in the first embodiment is set immediately after the radar apparatus is turned on, Correction processing is always performed before vehicle control such as inter-vehicle distance control using a radar apparatus is started, and thus a highly accurate and reliable antenna beam pattern can be formed.
In addition, if there is time before the vehicle-side system is activated immediately after power-on, it is possible to realize more accurate correction processing (which can ensure the degree of freedom of detection patterns used for phase and amplitude detection). It becomes.
As described above, the present embodiment is characterized in that the period for detecting the change in phase / amplitude is a predetermined period immediately after the power is turned on.

Embodiment 6 FIG.
In the present embodiment, it is determined that the vehicle on which the radar apparatus is mounted is stopped during the periodic detection period of the change amount of the phase / amplitude data for each reception system described in the first embodiment. In this case, it is possible to perform more frequent correction than shown in the fifth embodiment.
The radar apparatus can determine that the mounted vehicle is stopped by obtaining vehicle speed and wheel speed information through the communication means 132 with the vehicle system 600 as shown in FIG.
However, in the follow-up traveling system in the entire speed range, it is necessary to monitor the movement of the preceding vehicle even when the vehicle is stopped in a traffic jam. Therefore, it is not desirable to provide a detection period (correction period) using only speed information.
In general, it is difficult to consider that the following traveling system is in an effective state when considering the case where the vehicle is stopped with the power supplied to the radar apparatus and the side brake is applied.
Therefore, the periodic detection period of the phase / amplitude data is assumed to be a case where it is determined that the vehicle on which the radar apparatus is mounted is stopped and the side brake is set.
That is, in the radar apparatus according to the present embodiment, the period during which the phase / amplitude change is detected is set when the vehicle on which the radar apparatus is mounted is stopped and the side brake is determined to be in the set state. It is characterized by.

Embodiment 7 FIG.
FIG. 6 is a timing chart for explaining the operation of the radar apparatus according to the seventh embodiment.
6A shows the radar observation period (update period), FIG. 6B shows the received data acquisition period, and FIG. 6C shows the change observation period.
In the present embodiment, the periodic detection period of the change amount of the phase / amplitude data for each reception system described in the first embodiment is received within the radar observation period (update period) as shown in FIG. By making the period when data is not observed, correction can be made in real time every cycle.

Embodiment 8 FIG.
In this embodiment, the situation where the radar device is placed is analyzed by the CPU in the received data signal processing unit,
By combining the periodical detection period of the amount of change of the phase / amplitude data for each reception system with any convenient one of the ones of the detection periods shown in the fifth embodiment to the seventh embodiment, More practical correction can be made possible.

  The present invention is useful for realizing a radar apparatus capable of canceling the influence of a change in phase and amplitude of an electronic component due to temperature change and secular change and emitting an accurate antenna beam to a target.

1 is a block diagram showing a configuration of a radar apparatus according to Embodiment 1. FIG. It is a figure for demonstrating the characteristic structure of the radar apparatus by Embodiment 2. FIG. FIG. 10 is a diagram illustrating a configuration of a signal processing unit of an in-vehicle radio wave radar device according to a third embodiment. FIG. 6 is a block diagram illustrating a configuration of a radar apparatus according to a fourth embodiment. 10 is a timing chart for explaining the operation of the radar apparatus according to the fifth embodiment. 10 is a timing chart for explaining the operation of a radar apparatus according to a seventh embodiment. It is a block diagram which shows the structure of the conventional radar apparatus.

Explanation of symbols

1 Target 2 Voltage Control Oscillator (VCO)
DESCRIPTION OF SYMBOLS 3 1st divider | distributor 4 Transmission amplifier 5 Transmission antenna 6 1st switching means 7 2nd divider | distributor 9 3rd divider | distributor 10 Reception antenna part 11-14 Reception antenna 20 Mixer part 21-24 Mixer 30 Reception amplifier part 31-34 Reception amplifier 40 A / D converter part 41-44 A / D converter 50 2nd switching means 60 Phase / amplitude detection means 70 1st memory | storage means 80 Difference value detection output means 80
90 Second storage means 101, 103, 104 Signal processing means 111, 141 Reception data signal processing means 121 Detection period control means 131 CPU
132 Communication Unit 301 Attenuator 310 Comparison Unit 501 Radar Device 600 Vehicle System

Claims (8)

A transmission system comprising a transmission amplifier for amplifying a transmission signal output from a voltage controlled oscillator, a transmission antenna for emitting the transmission signal amplified by the transmission amplifier to a target, and a plurality of signals for receiving a reflected signal reflected by the target Receiving antennas, a plurality of mixers that respectively down-convert the received signals obtained by the plurality of receiving antennas, a plurality of receiving amplifiers that respectively amplify outputs of the plurality of mixers, and outputs of the plurality of receiving amplifiers In a radar apparatus that has a plurality of channel receiving systems each consisting of a plurality of A / D converters for converting each into a digital data, and detects a target based on the received data obtained for each of the plurality of receiving antennas,
A first distributor that distributes a transmission signal output from the voltage controlled oscillator to the transmission amplifier side and the reception system side, and a transmission signal output from the transmission amplifier is switched to the transmission antenna 5 side or the reception system side. Possible first switching means, a second distributor for distributing a transmission signal from the transmission amplifier to a plurality of channels of the reception system when the first switching means is switched to the reception system side, and A second switching means capable of switching a reception signal from the reception antenna and a transmission signal from the second distributor for each channel of the reception system and allowing the signals to be input to the plurality of mixers; A third distributor that distributes the transmission signal distributed to the reception system side by one distributor to each of the plurality of mixers; and the plurality of A / D converters for each channel of the reception system. And a signal processing means for correcting the reception data based on the transmission signal from the received signal and the second divider outputs from vessel, said signal processing means,
Phase / amplitude detection means for detecting a phase / amplitude of a transmission signal for each channel obtained when the second switching means is switched to the second distributor side, and a phase / amplitude detection means detected by the phase / amplitude detection means A first storage means for storing amplitude data; a detection period control means for controlling a period in which the phase / amplitude detection means detects phase / amplitude data; and a new one detected in a period set by the detection period control means Difference value detection means for obtaining a change amount between the phase / amplitude data and the phase / amplitude data stored in the first storage means, and the change amount obtained by the difference value detection output means as the next change amount Second storage means for storing until the detection period, and correction for correcting the phase and amplitude error for each reception system based on the phase / amplitude data stored in the first storage means and the second storage means By means Radar apparatus characterized by and a received data signal processing means that.   2. The radar apparatus according to claim 1, wherein an attenuator having a predetermined attenuation is provided between the first switching unit and the second distributor.   A vehicle having comparison means for comparing a difference value detected by the difference value detection means with a preset threshold value, and determining that there is a failure when there is a change greater than or equal to the threshold value, the vehicle on which the radar device is mounted The radar apparatus according to claim 1, further comprising means for notifying that the radar apparatus is out of order. A transmission system comprising a transmission amplifier for amplifying a transmission signal output from a voltage controlled oscillator, a transmission antenna for emitting the transmission signal amplified by the transmission amplifier to a target, and a plurality of signals for receiving a reflected signal reflected by the target Receiving antennas, a plurality of mixers that respectively down-convert the received signals obtained by the plurality of receiving antennas, a plurality of receiving amplifiers that respectively amplify outputs of the plurality of mixers, and outputs of the plurality of receiving amplifiers In a radar apparatus that has a plurality of channel receiving systems each consisting of a plurality of A / D converters for converting each into a digital data, and detects a target based on the received data obtained for each of the plurality of receiving antennas,
A first distributor for distributing a transmission signal output from the voltage controlled oscillator to the transmission amplifier side and the reception system side; and a transmission signal output from the transmission amplifier to a transmission antenna side or the reception system side And a second distributor that distributes a transmission signal from the transmission amplifier to a plurality of channels of the reception system when the first switching means is switched to the reception system side. A second switching means capable of switching a reception signal from the reception antenna and a transmission signal from the second distributor for each channel of the reception system and allowing the signals to be input to the plurality of mixers, respectively. A third distributor that distributes the transmission signal distributed to the reception system side by the first distributor to the plurality of mixers; and the plurality of A / S for each channel of the reception system. And a signal processing means for correcting the reception data based on the transmission signal from the received signal and the second divider outputs from the transducer, said signal processing means,
Phase / amplitude detection means for detecting a phase / amplitude of a transmission signal for each channel obtained when the second switching means is switched to the second distributor side, and for each channel detected by the phase / amplitude detection means First storage means for storing phase / amplitude data, detection period control means for controlling a period during which the first storage means detects phase / amplitude data, and phase / amplitude data stored by the first storage means. A radar apparatus comprising: received data signal processing means for correcting a phase / amplitude error for each receiving system based on a change in amplitude data.   The in-vehicle radio wave radar device according to any one of claims 1 to 4, wherein a period for detecting a change in the phase / amplitude data is a predetermined period immediately after power-on.   The period for detecting the change in the phase / amplitude data is a time when the vehicle on which the radar device is mounted is stopped and the side brake is determined to be in the set state. The radar device according to any one of the above.   The radar apparatus according to any one of claims 1 to 4, wherein a period for detecting a change in the phase / amplitude data is outside a reception data acquisition period within a radar observation period.   The radar apparatus according to any one of claims 1 to 4, wherein a period for detecting a change in the phase / amplitude data takes any combination of claims 6 to 8.

Images