JP4186744B2 - Radar equipment - Google Patents

Description

  The present invention relates to a radar device using a so-called frequency modulation continuous wave radar system (or FMCW: Frequency Modulated Continuous Wave), and in particular, each of an up phase (frequency rise period) and a down phase (frequency fall period). It is related with the technology which utilizes the information obtained from efficiently.

  A radar mounted on a vehicle or the like has a distance of a target to be measured (for example, a vehicle or an external obstacle) within a range of several meters to several hundred meters, and detects a measurement target within such a range. As the radar system, the FMCW system published in a plurality of publications (for example, Non-Patent Document 1, Non-Patent Document 2, Non-Patent Document 3, etc.) is often used.

  The operation principle of this FMCW radar system will be briefly described as follows. That is, first, the transmission signal is subjected to frequency modulation including a frequency rising period (hereinafter referred to as an up phase) and a frequency falling period (hereinafter referred to as a down phase), and the transmission signal is irradiated to an external target and reflected. A reflected signal is received as a received signal. Then, a beat signal between the transmission signal and the reception signal is generated, and the relative distance and relative speed of the external target are obtained from the frequency of the beat signal.

  Here, when there are N external targets (N is a natural number of 2 or more), a plurality of beat signal frequencies corresponding to each external target are calculated in each of the up phase and the down phase. In this case, the beat signal frequency in the up phase and the beat signal frequency in the down phase naturally have different values. Therefore, in order to stably calculate the relative distance and relative speed of N external targets, it corresponds to each external target from N beat signal frequencies in the up phase and N beat signals in the down phase. It is necessary to select a beat signal frequency to be set one by one and configure a frequency pair. Therefore, selection criteria for selecting a frequency pair have been proposed (for example, Patent Document 1 and Patent Document 2).

  In general, the relative distance and relative speed of these targets are repeatedly measured at preset time intervals. However, in reality, when targeting a vehicle, the frequency of the beat signal varies in time series measurement due to the reflection state of the vehicle and the characteristics of the components of the transceiver, etc. There was a problem that measurement results became unstable. Thus, as means for solving such a problem, it has been proposed to use information in the time-series direction regarding the frequency of the beat signal (for example, Patent Document 3, Patent Document 4, and Patent Document 5).

  However, both of these prior arts require a frequency pair consisting of the beat signal frequency in the up phase and the beat signal frequency in the down phase in order to obtain the distance and speed of the external target. Therefore, if one frequency cannot be obtained, a target that cannot be detected because a frequency pair cannot be selected even though it actually exists (a non-detection target), or a target that should not exist originally (Fake target) occurred, causing the reliability of the measurement results to decrease.

  As a means to solve such a problem, when a certain target is observed for the first time, the beat frequency in the up phase and the frequency pair of the beat frequency in the down phase are selected to obtain the target relative distance and relative speed. In the second and subsequent observations, the relative distance and relative speed of the target are calculated by using only the relative distance and relative speed obtained in the first time and the beat frequency in either the up phase or the down phase. A measuring method has been proposed (for example, Patent Document 6).

Japanese Patent Laid-Open No. 5-142337 "Millimeter Wave Radar Distance and Speed Measuring Device" JP-A-11-337635 “Scanning FM-CW Radar Signal Processing Device” Japanese Patent Laid-Open No. 5-142338 "Millimeter Wave Radar Distance Speed Measuring Device" Japanese Patent Laid-Open No. 5-150035 "Millimeter Wave Radar Distance Speed Measuring Device" Japanese Patent Laid-Open No. 5-249233 “Millimeter Wave Radar Device” WO02 / 067010 “Distance / Speed Measurement Method and Radar Signal Processing Device”

"Introduction to Radar Systems" M.I.SKOLNIK, McGRAW-HILL BOOK COMPANY, INC. (1962) "RADAR HANDBOOK" M.I.SKOLNIK, McGRAW-HILL BOOK COMPANY, INC. (1970) "Radar technology" supervised by Yoshida Manabu, IEICE (1989)

  In this method, only one of the up-phase beat signal frequency and the down-phase beat signal frequency is used in the second and subsequent relative distance and relative speed calculation processes. For this reason, even when the beat signal frequencies of both the up phase and the down phase are obtained, either one is discarded, and there is a problem that the data use efficiency is poor. That is, for example, when only the up phase is used, no measurement is actually performed until the down phase elapses. As a result, this problem becomes apparent in the form of degradation of target detection probability and degradation of target distance / speed measurement accuracy.

  Therefore, in the radar device according to the present invention, when both the up-phase and down-phase beat signal frequencies are obtained without depending on the selection of the frequency pair, the target frequency is obtained using both frequencies. The purpose is to improve the measurement accuracy of detection probability and target distance / speed.

The radar apparatus according to the present invention performs frequency modulation including an up phase (frequency increase period) and a down phase (frequency decrease period) on a transmission signal, and radiates the transmission signal to an external target. A sensor that receives the reflected signal of
Frequency analysis means for extracting beat signal frequency observation values of the transmission signal and the reception signal;
Distance speed calculation means for calculating the current distance and speed of the external target based on the beat signal frequency observation value extracted by the frequency analysis means in the up phase and the down phase;
Tracking means for calculating respective predicted values of the distance, speed and beat signal frequency of the external target after a predetermined time from the current distance and speed;
A radar apparatus comprising:
Further comprising tracking result storage means for storing predicted values of the distance, speed and beat signal frequency of the external target,
The tracking unit calculates the next predicted value based on the predicted value of the immediately previous phase stored in the tracking result storage unit when the transmission signal newly shifts to the up phase or the down phase. Is.

Further, tracking result storage means for storing the predicted values of the distance, speed and beat signal frequency of the external target individually for the up phase and the down phase,
Integration means for calculating an integrated prediction value by integrating the up-phase and down-phase prediction values stored in the tracking result storage means.

  Since the radar apparatus according to the present invention does not depend on the frequency pair, the target distance / speed can be measured even when the beat signal frequency of either the up phase or the down phase cannot be obtained. In addition, when both up-phase and down-phase beat signal frequencies are obtained, the target distance and speed are measured using both beat signal frequencies, so either the up-phase or the down-phase Compared to measuring the target distance / speed using only one of them, the target detection probability and the target distance / speed measurement accuracy are improved.

  In addition, the continuous wave radar according to the present invention has tracking result storage means for each of the up phase and the down phase, and is provided with an integration means for integrating them. Measurement results can be integrated so that the measurement error does not affect the measurement error of the other phase.

Embodiments of the present invention will be described below with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of a radar apparatus according to Embodiment 1 of the present invention. In the figure, a sensor 11 irradiates an external target with a transmission signal subjected to frequency modulation consisting of an up phase and a down phase as a radio wave, receives the reflected wave, and beats the reception signal and the transmission signal obtained therefrom. A signal is output. The A / D converter 12 is an element or a circuit that converts a beat signal that is an analog signal into a digital signal. The frequency analysis unit 13 is a part for obtaining the frequency of the beat signal sampled by the A / D converter 12. The frequency analysis means is constituted by an A / D converter 12 and a frequency analysis unit 13.

  The switch 14 is a switch element or circuit that includes at least one movable terminal, an input end, and two output ends composed of D1 and D2. Control of the movable terminal is performed by a control means (not shown) (control circuit or element, or central processing unit that executes a computer program). This control means connects the movable terminal to the output terminal D1 when calculating the initial value, and connects to the output terminal D2 otherwise.

  The time information memory 15 is a storage element or circuit for storing the observation time. When the sensor 11 outputs a beat signal, the sampling interval extraction unit 16 calculates a time difference between the current time and the time information memory 15 and outputs it as a sampling interval.

  The phase determination unit 17 is a part that determines whether the current radar apparatus is in the up phase or the down phase. The frequency modulation is normally performed by a voltage controlled oscillator (or VCO: Voltage Controlled Oscillator) (not shown). The phase determination unit 17 acquires a control signal for controlling the VCO and outputs phase determination information. It may be.

  The up-phase tracking filter 18 and the down-phase tracking filter 19 are parts that perform the tracking process when the transmission signal is in each of the up-phase and down-phase periods. These may be realized by a dedicated circuit or element using a DSP or the like, but may be realized in a form in which a general-purpose central processing unit (CPU) executes a computer program. In the first embodiment, the up-phase tracking filter 18 and the down-phase tracking filter 19 are prepared for each of the up-phase and the down-phase. However, the tracking processing for both periods is performed by either one of the tracking filters. You may make it also use. The up-phase tracking filter 18 and the down-phase tracking filter 19 correspond to tracking means.

  The tracking result storage unit 20 is a storage element or circuit for storing the tracking processing results of the up-phase tracking filter 18 and the down-phase tracking filter 19. The tracking result storage unit 20 corresponds to tracking result storage means.

  The frequency pair selection unit 21 is a part that operates only at the time of observation using the first beat signal frequency, and performs a frequency pair selection process including a pair of a beat signal frequency in the up phase and a beat signal frequency in the down phase. . The distance / speed deriving unit 22 is a part that calculates the relative distance and the relative speed of the external target based on the frequency pair subjected to the frequency pair selection process.

  Next, detailed configurations of the up-phase tracking filter 18 and the down-phase tracking filter 19 will be described. FIG. 2 is a block diagram showing a detailed configuration of the up-phase tracking filter 18. The configuration of the down-phase tracking filter 19 is the same as the configuration of the up-phase tracking filter 18. In the figure, a frequency prediction unit 23 is a part that calculates a predicted value of the next beat signal frequency based on a predicted value of distance / speed. In the FMCW radar system, the beat signal frequency and the relative distance / relative speed of the external target have a predetermined relationship, and the beat signal frequency is calculated based on the relationship. This relationship will be described later.

  The correlation determination unit 24 is a part that determines the correlation between the predicted value of the beat signal frequency calculated by the frequency prediction unit 23 and the observed value of the beat signal frequency output by the frequency analysis unit 13. The distance / speed smoothing unit 25 uses the beat signal predicted value determined by the correlation determining unit 24 to be correlated with the observed beat signal frequency value, the distance / speed predicted value, and the beat output from the frequency analyzing unit 13. This is the part where the distance and speed are smoothed from the observed signal frequency. The smooth values of the distance and speed are stored in the tracking result storage unit 20 and used for the next tracking process. The distance / speed prediction unit 26 is a part that calculates a predicted value of the next distance / speed based on the previous smooth value of the distance / speed. The distance / speed prediction values are output to the frequency prediction unit 23.

  Next, the operation of the radar apparatus according to Embodiment 1 of the present invention will be described. First, the sensor 11 performs frequency modulation consisting of an up-phase and a down-phase at regular intervals on the transmission signal, irradiates the external target with a carrier wave, and receives a radio wave reflected from the external target as a reception signal. And

  FIG. 3 is a graph showing the relationship between a transmission signal, a reception signal, and a beat signal in this radar apparatus employing the FMCW radar system. In the figure, 1 indicates the time lapse of the carrier frequency of the transmission signal that the sensor 11 irradiates to the external target as a radio wave (carrier wave). Reference numeral 2 denotes the time lapse of the carrier wave frequency of the radio wave reflected by the external target and received by the sensor 11 as a reception signal among the radio waves irradiated to the external target. For convenience of explanation, in the following explanation, this transmission signal is referred to as transmission signal 1 and the reception signal is referred to as reception signal 2. Thus, the transmission signal 1 repeats the up phase and the down phase at regular intervals. On the other hand, the carrier frequency of the reception signal 2 exhibits a property of increasing / decreasing slightly after the carrier frequency of the transmission signal 1. This is because there is a time difference until the transmission signal 1 radiated from the sensor 11 reaches the external target, is further reflected, and returns to the sensor 11.

The sensor 11 outputs a beat signal by mixing the transmission signal 1 and the reception signal 2 using a mixer (multiplier) or the like. Here, the frequency of the beat signal in the up-face is U, and the frequency of the beat signal in the down-phase is D. FIG. 3 shows the time lapse of the frequency of the beat signal thus obtained, and illustrates the frequencies U and D of the beat signal. In the following description, this beat signal is referred to as beat signal 3. The beat signal 3 is subjected to signal processing, and the distance and speed of the external target are calculated. FIG. 4 is a flowchart of such signal processing.

  First, prior to the processing shown in this flowchart, the initialization flag f is set to 0. And in step P1 of the flowchart of FIG. 4, the sampling interval extraction part 16 extracts a sampling interval. That is, the difference between the previous time read from the time information memory 15 and the current time detected from the sensor 11 is calculated to obtain the sampling interval Δt. In the initial state (when f = 0), Δt = 0 is set since the previous time is not recorded in the time information memory 15. In addition to the calculation of the sampling interval Δt, the current sampling time is stored in the time information memory 15. This makes it possible to obtain a meaningful sampling interval in the next measurement.

  Next, the beat signal is digitally converted by the A / D converter 12. Then, each beat signal frequency is extracted from the beat signal of the up phase or the down phase by the frequency analysis unit 13 (step P2). Here, for example, by frequency analysis using fast Fourier transform, up-phase or down-phase frequencies U (t) i and D (t) i (where i = 1, 2,...) Corresponding to a plurality of external targets are obtained. Each is extracted.

  Next, in step P3, the value of the initialization flag is tested. Since f = 0 in the initial state, the process proceeds to Step P4 (Step P3: Yes). The case of f ≠ 0 will be described later. Then, the sampling interval is extracted again in the same manner as in step P1 (step P4), and then the beat signal is extracted in the same manner as in step P2 (step P5).

  The frequency pair selection unit 21 selects a frequency pair {U (t) x, D (t) y} from the beat frequencies U (t) i and D (t) i obtained in steps P2 and P5 ( Step P6). Since several known techniques have already been proposed as frequency pair selection methods, description thereof is omitted here.

ここで、Ｂは周波数掃引幅、Ｔは周波数掃引時間、ｃは光速、λは送信波の波長である。 Next, the distance / speed deriving unit 22 calculates the relative distance r and the relative speed v of the external target from the beat frequencies of the up phase and the down phase obtained so far (step P7). After the calculation, the relative distance r and the relative speed v of the external target are stored in the tracking result storage unit 20. Here, the frequencies of the up-phase and down-phase beat signals in the FMCW system (for simplicity, U and D), the relative distance r and the relative speed v of the external target are expressed by the following equations (1) and (1): Satisfy (2).

Here, B is the frequency sweep width, T is the frequency sweep time, c is the speed of light, and λ is the wavelength of the transmission wave.

From these relationships, Equations (3) and (4) are obtained.

The relative distance r and the relative speed v of the external target are given as Expression (5) and Expression (6) by modifying Expression (3) and Expression (4).

  Subsequently, the value of the initialization flag f is set to 1 (step P8), and the relative distance r and the relative speed v of the external target calculated by the equations (5) and (6) are output to an external device (not shown). (Step P9). Thereafter, the process returns to step P1 again, and sampling interval extraction and beat signal extraction in step P2 are performed. Since f = 1 in Step P3, the process proceeds to Step P10 (Step P3: No), and the phase is determined by the phase determiner 17. That is, if the current phase is the up phase, the up phase tracking filter 18 is selected, and if the current phase is the down phase, the down phase tracking filter 19 is selected.

  In each of the tracking filters of the up-phase tracking filter 18 and the down-phase tracking filter 19, processing from Step P <b> 11 to Step P <b> 14 (tracking processing) is performed. Therefore, in the following description, it is assumed that the current observation is in the up phase as an example. Even if the observation value is not obtained, the process is executed with a filter corresponding to the current observation state.

なお、前回の処理が初期処理（ｆ＝０の場合に実行される処理）である場合は、平滑処理は行われていないので、代わりにステップＰ７で算出され追尾結果記憶部２０に記憶されている距離と速度を用いることとする。 In the tracking process, first, the distance / velocity prediction unit 26 uses the smoothing value Rs (t) of the previous distance and the smoothing value Vs (t) of the speed stored in the tracking result storage unit 20 to determine the external values at the current observation time t + Δt. Assuming the target motion, the predicted values Rp (t + Δt) and Vp (t + Δt) of the distance and speed are calculated (step P11). For example, when it can be assumed that the target moves at a constant speed, Rp (t + Δt) and Vp (t + Δt) are calculated by the equations (7) and (8).

If the previous process is an initial process (a process executed when f = 0), the smoothing process is not performed. Instead, it is calculated in step P7 and stored in the tracking result storage unit 20. The distance and speed are used.

  Next, the frequency predicting unit 23 calculates the predicted value Up (t + Δt) of the beat signal frequency in the up phase using the predicted value Rp (t + Δt) of the distance and the predicted value Vp (t + Δt) of the speed using the equation (1). (Step P12).

  Further, the correlation determination unit 24 calculates the correlation between the up-phase beat signal frequency predicted value Up (t + Δt) and the up-phase beat frequency U (t + Δt) i, that is, the correspondence between the predicted value and the beat signal frequency. The observed value U (t + Δt) x is determined (step P13). Here, as a method of determining the correlation, for example, a method of selecting the observed value U (t + Δt) closest to the predicted value Up (t + Δt) of the beat frequency, a probability distribution of the observed value centering on the predicted value Up (t + Δt) The likelihood γ (t + Δt) i of the observation value is calculated on the assumption that follows a normal distribution, and the observation value is weighted and integrated based on the magnitude of γ (t + Δt) i.

  When the observed value U (t + Δt) cannot be obtained (in the case of no detection), the correlation determining unit 24 uses the distance smooth value Rs (t + Δt) and the speed smooth value Vs (t + Δt) as the tracking result storage unit 20. May be substituted by the predicted distance value Rp (t + Δt) and the predicted speed value Vp (t + Δt) stored in (memory track processing). By doing in this way, the problem that the measurement result of distance and speed becomes unstable by the reflective state of a vehicle, the characteristic of the component of a transmitter / receiver, etc. can be prevented.

ここで計算された平滑値、予測値は追尾結果記憶部２０に記憶され、次回の追尾処理に用いられる。 Subsequently, the distance / speed smoothing unit 25 calculates the distance smoothing value from the distance predicted value Rp (t + Δt), the speed predicted value Vp (t + Δt), the frequency predicted value Up (t + Δt), and the observed value U (t + Δt). Rs (t + Δt) and the smoothed speed value Vs (t + Δt) are calculated (step P14). For these calculations, for example, tracking filters such as a Kalman filter and a PDA (Probabilistic Data Association) filter are used in addition to Expressions (9) and (10) according to Patent Document 6.

The smoothed value and the predicted value calculated here are stored in the tracking result storage unit 20 and used for the next tracking process.

  Next, as in the case of f = 0, the relative distance r and relative speed v of the external target obtained by the above tracking process are output to an external device (not shown) (step P9).

  In the above, each of the tracking filters of the up-phase tracking filter 18 and the down-phase tracking filter 19 has a memory track function, so even if the measured value of either the up-phase or the down-phase cannot be used. Measurement can be performed only in the remaining phases. In addition, this radar device is characterized in that when the frequency of the beat signal is observed from both the up phase and the down phase, the measurement accuracy is further improved by using the frequency observation values of both phases. It is said. That is, the distance / speed prediction unit 26 uses the smooth value of the relative speed and the smooth value of the relative distance of the external target as the previous smooth value. For this reason, even when the current observation shifts to a different phase from the previous observation, the frequency of the beat signal obtained as the observation value can be used in general. In other words, even when the previous phase is the up phase and this time is the down phase, or when the previous time is the down phase and the current time is the up phase (when this time newly transitions to the up phase or the down phase), the latest smooth value is always used. The accuracy of the tracking process is improved. If the beat signal frequency is used only for the up phase or only for the down phase, the observation value for the period until the end of the phase cannot be used when switching to a different phase. The accuracy is naturally deteriorated, but such a problem does not occur in this radar apparatus.

  Furthermore, this radar apparatus integrates frequency prediction processing of beat signals in up-phase and down-phase using smooth values of the relative distance and relative velocity of the external target. For this reason, even in the situation where there are a plurality of external targets, it is not necessary to create frequency pairs of up-phase and down-phase beat signals except for the initial processing. Therefore, it is possible to perform stable measurement processing independent of the external target radio wave reflection state.

  Note that a smooth value of the beat signal frequency may be used instead of the smooth value of the relative distance and the relative speed of the external target. In this case, since the relative distance and the relative speed of the external target can be obtained by the equations (5) and (6), the same effect can be obtained as a result. However, in this case, smooth values of beat signal frequencies in both the up phase and the down phase are required.

  As is clear from the above, according to the radar apparatus according to the first embodiment of the present invention, the relative distance of the external target is calculated using both the up-phase beat signal frequency and the down-phase beat signal frequency. Since the relative speed is obtained, the data can be used efficiently, and the measurement accuracy of the relative distance and the relative speed of the external target can be improved.

  In the above description, the sampling interval extracted by the sampling interval extraction unit 16 is used as the value of Δt. However, instead of this, a predetermined time may be used.

  In step P11, the sampling interval Δt extracted by the sampling interval extraction unit 16 is newly used from the previous distance and velocity smoothed values Rs (t) and Vs (t) read from the tracking result storage unit 20. Predicted values Rp (t + Δt) and Vp (t + Δt) are calculated. However, instead of this, a predicted value is calculated in advance using a predetermined time and stored in the tracking result storage unit 20, and these values are read out and used as a predicted value when necessary. May be.

Embodiment 2. FIG.
According to the radar device according to the first embodiment, even when there are a plurality of external targets, the frequency of both beat signals is selected without selecting the frequency pair of the up phase and down phase beat signals. It is possible to improve the measurement accuracy. However, when the frequencies of the beat signals are too close to each other on the frequency plane and cannot be separated, it may be assumed that the correlation cannot be determined correctly. Therefore, it is examined how close the predicted value Up (t) of the beat signal frequency in the up phase and the predicted value Dp (t) of the beat signal frequency in the down phase are, and the predicted values are close to each other. In this case, the observed value U (t) x of the frequency of the beat signal in the up phase and the D (t) y of the frequency of the beat signal in the down phase may not be used. The radar apparatus according to the second embodiment performs such an operation.

  FIG. 5 is a block diagram showing the configuration of the radar apparatus according to the second embodiment. In the figure, a predicted value determination unit 31 and a predicted value determination unit 32 are parts that determine whether the frequency predicted value and smooth value of the beat signal stored in the tracking result storage unit 20 satisfy a predetermined condition. Note that the predicted value determination unit 31 is used for signal processing of the up phase, and the predicted value determination unit 32 is used for signal processing of the beat signal in the down phase. Further, the up-phase tracking filter 18 and the up-phase tracking filter 19 use only the predicted frequency value and smooth value of the beat signal that satisfy the predetermined condition in the predicted value determination unit 31 and the predicted value determination unit 31. Tracking processing is performed. The other components having the same reference numerals as those in FIG. 1 are the same as those in the first embodiment, and thus the description thereof is omitted.

  Next, the operation of the radar apparatus according to the second embodiment will be described. A flowchart showing the operation of this radar apparatus is shown in FIG. 4 as in the radar apparatus of the first embodiment. Therefore, here, the description will focus on portions that operate differently from the first embodiment, and other processing will be the same as in the first embodiment. First, since the processing from step P1 to step P10 is the same as that of the first embodiment, the description thereof is omitted. In the following description, it is assumed that the processing up to Step P10 has already been completed, the phase is the up phase, the target i and the target j are observed, and the beat frequencies U (t + Δt) i, U ( It is assumed that t + Δt) j is obtained.

In this state, the distance / speed prediction unit 26 predicts the relative distance and relative speed at time t + Δt based on the relative distance and relative speed of the external targets i and j of the previous time (time t) from the tracking result storage unit 20. Prior to the processing, the predicted value determination unit 31 reads the previous beat frequency predicted values Up (t) i and Up (t) j, and sets the external target i as, for example, by equation (11). The distance value dUp (t) i, j of the beat frequency prediction value of the external target j is calculated.

Subsequently, for example, it is verified whether or not the relationship of the expression (12) is satisfied with respect to the preset threshold value dUpth, and then the processing of the distance / speed prediction unit 26 is executed. Note that for the predicted values i and j that do not satisfy Expression (12), it is assumed that the observed value U (t + Δt) x is not obtained, and the memory track processing described in the first embodiment is performed. Good.

  As can be seen from the above, according to the radar apparatus of the second embodiment of the present invention, the frequencies of the beat signals are too close to each other on the frequency plane to be separated, and thus the correlation cannot be determined correctly. However, since the measurement process is performed without using a beat signal frequency that cannot be separated, the relative distance and relative speed of the external target can be measured without degrading the measurement accuracy.

  In the second embodiment, the frequency distance value of the external target is calculated using the frequency prediction values Up (t) i and Up (t) j of the previous beat signal stored in the tracking result storage unit 20. However, in addition to this, the prediction value determination unit 31 is arranged between the frequency prediction unit 23 and the correlation determination unit 24 so that the beat signal frequency prediction values Up (t + Δt) i, Up (t + For t + Δt) j, for example, a distance value according to the equation (11) may be calculated, and a test process according to the equation (12) may be performed to transmit the test result to the correlation determination unit 24. Even in this case, when the test is not satisfied in Expression (12), the correlation determination unit 24 does not perform the correlation process, so that an erroneous observation value can be prevented from being adopted.

Embodiment 3 FIG.
In addition, when the frequencies of the beat signals for a plurality of external targets are close to each other, the prediction determination units 31 and 32 not only reject those observation values but also control the sensor 11 to change the resolution. It may be. The radar apparatus according to Embodiment 3 of the present invention has such a purpose.

  FIG. 6 is a block diagram showing a configuration of a radar apparatus according to Embodiment 3 of the present invention. In the figure, the sensor control unit 33 acquires the determination result of the predicted value determination unit 31 for the up phase and the predicted value determination unit 32 for the down phase, particularly the determination result when the condition is not satisfied, and corresponds to the result. This is the part that controls the sensor 11. Further, the resolution of the sensor 11 can be changed by a control signal or parameter input from the sensor control unit 33.

  Next, the operation of the radar apparatus according to Embodiment 3 of the present invention will be described. For example, the predicted value determiners 31 and 32 output to the sensor control unit 33 that there is an external target that does not satisfy the formula (12), that is, an external target that cannot be resolved. The presence / absence of an external target that cannot be resolved may be output to the sensor control unit 33 as an on / off signal (consisting of 0 and 1), or the number of external targets that cannot be resolved may be output.

  Next, the sensor control unit 33 acquires signals from the predicted value determiners 31 and 32 and outputs a signal or parameter that increases the resolution of each phase to the sensor 11. As a result, the sensor 11 irradiates the external target with a transmission signal with a higher resolution than the present, and receives the reflected reception signal.

  As is clear from the above, according to the radar apparatus according to the third embodiment of the present invention, the resolution is dynamically changed based on the beat signal frequency of the external target. Detection can be prevented.

  In the above description, a configuration using a sensor that can change the resolution by inputting an external signal is assumed as the sensor 11, but the configuration is not limited to such a configuration. That is, even when a sensor whose resolution cannot be changed is used, erroneous detection can be prevented by using the outputs of the predicted value determiners 31 and 32 as follows. That is, the determination results of the predicted value determiners 31 and 32 are output to the sensor 11 and the frequency analysis unit 13 in advance. If an external target that cannot be resolved in one phase exists among them, only the beat signal of the other phase is generated or the frequency is output.

  Further, when the predicted value determination units 31 and 32 output the number of external targets that cannot be decomposed, the number of external targets that cannot be decomposed in both phases is compared, and only the phase having the smaller number of external targets that cannot be decomposed is compared. You may employ | adopt the structure measured using. This is because the number of external targets that cannot be resolved is considered to increase as the resolution decreases.

Embodiment 4 FIG.
In the radar apparatus according to the first to third embodiments described above, one tracking result is shared in both the up phase and the down phase, but these are individually stored in each phase. Thus, the configuration may be such that one phase is not affected by the tracking result of the other phase, and these are separately integrated and output. The radar device according to the fourth embodiment of the present invention is for this purpose.

  FIG. 7 is a block diagram showing a configuration of a radar apparatus according to Embodiment 7 of the present invention. In the figure, an up-phase tracking result storage unit 41 and a down-phase tracking result storage unit 42 are storage elements, circuits, or storage devices for storing the results of the tracking processing of the respective phases. The result is the same as that of the tracking result storage unit 20 in the first to third embodiments except that the results are stored individually. The integration unit 43 is a unit that integrates the tracking results stored in the up-phase tracking result storage unit 41 and the down-phase tracking result storage unit 42 by performing weighting using a smooth error covariance matrix. The other components having the same reference numerals as those in FIG. 1 are the same as those in the first embodiment, and thus the description thereof is omitted.

  FIG. 8 is a block diagram showing a detailed configuration of the integration unit 43. In the figure, weight coefficient calculation units 44 and 45 are parts for calculating weight coefficients for the up-phase tracking result and the down-phase tracking result, respectively. The integration operation unit 46 is a part that performs an operation of integrating the up-phase tracking results and the down-phase tracking results using the weighting coefficients calculated by the weighting coefficient calculation units 44 and 45.

  Next, the operation of the radar apparatus according to Embodiment 4 of the present invention will be described. FIG. 9 is a flowchart showing the operation of the radar apparatus. In the figure, steps denoted by the same reference numerals as those in the flowchart of FIG. 4 are the same as those in the first embodiment, and thus description thereof is omitted. Prior to this process, the initialization flag f is set to 0 as in the first embodiment. Further, in the radar apparatus of the fourth embodiment, a processing status determination flag P indicating the progress status of the up-phase signal processing and the down-phase signal processing is provided, and the value of the processing status determination flag P is set to 0. deep. When the processing status determination flag P is 0, it indicates that either the up-phase signal processing or the down-phase signal processing has not yet been performed, and when the value of P is 1, both signal processing is performed. Indicates the finished state.

  The processing from step P1 to step P6 is the same as in the first embodiment. In step P7, the distance / speed deriving unit 22 calculates the distance and speed in the same manner as in the first embodiment. In the fourth embodiment of the present invention, in addition to the calculation of the distance and speed, the up phase and the down phase are calculated. A smoothing error covariance matrix is calculated for each of the external targets for each of. The smoothing error covariance matrix Psu (t) i for each external target in the up phase is stored in the tracking result storage unit 41 for the up phase, and the smoothing error covariance matrix Psd (t) for each external target in the down phase. i is stored in the tracking result storage unit 42 for the down phase.

  Subsequently, after setting f = 1 (step P8), the distance and speed calculated by the distance / speed deriving unit 22 are output (step P9), returning to step P1 and performing the same processing as in the case of f = 0 until step P2. I do. Since f = 1 in Step P3, the process proceeds to Step P101. In step P101, processing corresponding to the processing (tracking processing) from step P10 to step P14 in the flowchart of FIG. 4 is performed. However, the distance / velocity smoothing unit 25 calculates a smoothing error covariance matrix in addition to the calculation of the respective smooth values of the relative distance and the relative speed of the external target. The smoothing error covariance matrix Psu (t) i for each external target in the up phase is stored in the tracking result storage unit 41 for the up phase, and the smoothing error covariance matrix Psd (t) for each external target in the down phase. i is stored in the tracking result storage unit 42 for the down phase. When the processing of step P101 is completed, the up-phase signal processing is completed, the frequency U (t) i of the up-phase beat signal, the predicted value of the relative distance and relative speed of the external target based on them, and the observation It is assumed that a value is calculated and stored in the up-phase tracking result storage unit 41.

  Subsequently, the value of the processing status determination flag P is verified (step P21). When the value of P is 0, the process proceeds to Step P22 (Step P21: Yes). Since the value of P is 0 in the initial state, the processing after step P22 will be described first, and the processing when the value of P is not 0 will be described later.

  Next, in step P22, the sampling interval extraction unit 16 extracts the sampling interval. Further, in step P23, the beat signal of the down phase is extracted. Since the sampling interval extraction method and the down-phase beat signal extraction are the same as those in the first embodiment, description thereof will be omitted. As a result, it is assumed that the frequency D (t) i of the beat signal in the down phase is obtained. Thereafter, the value of the process status determination flag P is set to 1 (step P24), and the process returns to the process of step P101 to execute the tracking process for D (t) i. Then, it is assumed that predicted values and observed values of the relative distance and relative speed of the external target based on them are calculated and stored in the down-phase tracking result storage unit 42.

  Next, it is verified again whether or not the value of the processing status determination flag P is 0 (step P21). Here, since P = 1, the process proceeds to the integration process of step P25 (step P21: No). In Step P25, the integration unit 43 reads the tracking results from the up-phase tracking result storage unit 41 and the down-phase tracking result storage unit 42, and performs an integration process for collecting the results into one measurement result.

Next, the integration process performed by the integration unit 43 will be described in detail. Here, as a method for integrating the measurement result in the up phase and the measurement result in the down phase, weighting using a smooth error covariance matrix is performed. As described above, the smoothing error covariance matrix is calculated in advance by the distance / velocity deriving unit 22 and the distance / velocity smoothing unit 25, and the upphase tracking result storage unit 41 stores the smoothing error covariance of each external target in the upphase. The variance matrix Psu (t) i and the down-phase tracking result storage unit 42 store the smoothing error covariance matrix Psd (t) i of each external target. First, the weighting factor calculation units 44 and 45 obtain the weighting factors Wu (t) i and Wd (t) i from the smoothing error covariance matrices of the respective external targets in the up phase and the down phase, respectively, using the equations (13) and (13). Calculate based on (14).

  The weighting factors Wu (t) i and Wd (t) i calculated by the weighting factor calculation units 44 and 45 are smooth values read from the up-phase tracking result storage unit 41 and the down-phase tracking result storage unit 42. Rsu (t) i, Vsu (t) i, Rsd (t) i, and Vsd (t) i are added respectively.

以上が統合部４３における処理である。 Next, the integration calculation unit 46 integrates the calculation results of the weighting coefficient calculation units 44 and 45 by the equation (15), and obtains the relative distance and the relative speed.

The above is the processing in the integration unit 43.

  Then, the value of the processing status determination flag P is set to 0 again (step P25), the result is output (step P9), and the process proceeds to the next up-phase and down-phase signal processing.

  As is apparent from the above, according to the radar device of the fourth embodiment of the present invention, the up-phase and down-phase beat signals are not dependent on the frequency pair selection of the up-phase and down-phase beat signals. Utilization can improve measurement accuracy.

  Furthermore, the beat signal obtained in the up phase and the beat signal obtained in the down phase are processed independently of the other phases, and the measured values of the relative distance and relative speed are obtained, and then the integration processing is performed. Thus, it is possible to prevent an error in the measurement value in the up phase and the down phase from propagating to the measurement value in the other phase. For this reason, it is possible to improve the measurement accuracy of the relative distance / relative speed of the external target.

In the above, the measurement results in the up phase and the measurement results in the down phase are integrated using the smooth error covariance matrix. However, in addition to this, a method of integrating by weighting using residual information, which is the difference between the predicted value of the beat signal of the external target and the observed value, is also conceivable. In other words, the up-phase tracking result storage unit 41 stores the predicted value Up (t) i and the observed value Up (t) x of the frequency of the external target beat signal, and the down-phase tracking result storage unit. 42 stores the predicted value Dp (t) i and the observed value Dp (t) x of the frequency of the beat signal of the external target. Then, the beat frequency residuals Su (t) i and Sd (t) i are calculated by the equations (16) and (17).

Next, the beat frequency residuals Su (t) i and Sd (t) i are converted into weighting coefficients so that the weighting coefficients become smaller as the residuals become larger. For example, a method of normalizing and using the reciprocal of the residual can be considered. For example, the integrated prediction values Rs (t) i and Vs (t) i are obtained from the smoothed values Rsu (t) i, Vsu (t) i, Rsd (t) i, and Vsd (t) i by Expression (18). .

  By doing this, the phase with a large residual, that is, the predicted value and the observed value are far apart and the influence of the phase with the degraded reliability is reduced, and the phase with a small residual, that is, a highly reliable phase As a result, the measurement accuracy can be improved.

  In addition to the smoothing error covariance matrix and residual information, a method of integrating up-phase and down-phase measurement results by weighting using a time series of residual information is also conceivable. The time series of the residual information is a sequence of differences at the same time in the time series of the predicted value of the beat signal and the observed value (sequence of the predicted value and the observed value of the beat signal at each time). Specifically, first, the time series {Up (T) x, Dp (T) x: ts ≦ T ≦ t} of the observed values of the beat signal frequency of each external target and the predicted value of the beat signal frequency Every time the time series {Up (T) i, Dp (T) i: ts ≦ T ≦ t} is calculated by the distance / speed deriving unit 22, the up-phase tracking filter 18, and the down-phase tracking filter 19, This is stored in the tracking result storage unit 41 and the tracking result storage unit 42 for the down phase. Note that ts is a time and is set as a parameter in advance.

  Next, the time series {Su (T) i, Sd (T) i: ts ≦ T ≦ t} of the residuals at each time is calculated by the equations (16) and (17). The residual at each time is calculated by the distance / speed deriving unit 22, the up-phase tracking filter 18, and the down-phase tracking filter 19, and the time series of the residual is stored as the up-phase tracking result. It may be stored in the unit 41 and the tracking result storage unit 42 for the down phase.

Subsequently, the residual time series {Su (T) i, Sd (T) i: ts ≦ T ≦ t} are integrated, respectively, and the integrated residual {Sut (T) i, Sdt (T) i} is obtained. calculate. As a method for integrating residuals, the number of samples used for integration is set as Ns, for example, a method using a simple average shown in Equation (19) and Equation (20), or a weighting factor Aj shown in Equation (21) and Equation (22). An integration method based on weighted moving average using Bj can be considered.

  Then, Sut (T) i and Sdt (T) i obtained in this way are converted into weighting coefficients so that the larger the residual, the smaller the weighting coefficient. Specifically, for example, by substituting Sut (T) i and Sdt (T) i for Su (t) i and Sd (t) i in Expression (18), respectively, integrated prediction values Rs (t) i and Vs (T) Find i.

  In this way, the weighting factor is statistically calculated from the predicted value of the beat signal of the external target within the preset number of samples or time and the observed value of the beat signal, and the measurement results of the up phase and the down phase are integrated. As a result, it is possible to suppress the influence of a case where the measurement result is temporarily detected erroneously, to accurately reflect the measurement accuracy of each phase in the integration, and to improve the measurement accuracy.

Embodiment 5 FIG.
In Embodiments 1 to 4 described above, the measurement accuracy is improved by combining the measurement results of the up phase and the down phase. On the other hand, a method of improving the measurement accuracy by improving the accuracy of the correlation determination process between the predicted value and the observed value is also conceivable. Specifically, gate information that is a correlation determination condition in the correlation determination unit 24 is created based on the better measurement accuracy of either the up phase or the down phase, and this gate information is shared by both phases. Therefore, the deterioration of measurement accuracy is prevented. The radar apparatus according to Embodiment 5 of the present invention has such a purpose.

  FIG. 10 is a block diagram showing a configuration of a radar apparatus according to Embodiment 5 of the present invention. In the figure, a gate information creation unit 51 is a part that creates a gate based on measurement results of beat signal frequencies in the up phase and the down phase. The correlation determination unit 24 of the up-phase tracking filter 18 and the down-phase tracking filter 19 takes in the gate information created by the gate information creation unit 51 and performs correlation determination processing. The other components having the same reference numerals as those in FIG. 7 are the same as those in the fourth embodiment, and thus the description thereof is omitted.

  FIG. 11 is a block diagram showing a detailed configuration of the gate information creation unit 51. In the figure, an up-phase frequency predicting unit 52 and a down-phase frequency predicting unit 53 are configured based on the up-phase beat signal frequency predicted values stored in the up-phase tracking result storage unit 41, respectively. This is the part that performs the process of predicting the beat signal frequency in the down phase. Further, the down-phase frequency predicting unit 54 and the up-phase frequency predicting unit 55 respectively increase and decrease the down-phase beat signal frequency based on the down-phase beat signal frequency predicted value stored in the down-phase tracking result storage unit 42. This is the part that performs the process of predicting the beat signal frequency of the phase. The gate calculation unit 56 is a part that performs gate calculation based on the outputs of the up-phase frequency prediction unit 52 and the down-phase frequency prediction unit 53. The gate calculation unit 57 is a part that performs gate calculation based on the outputs of the down-phase frequency prediction unit 54 and the up-phase frequency prediction unit 55. The gate creation unit 58 is a part that creates a gate based on the processing results of the gate calculation units 56 and 57.

  First, the gate will be described. The gate is a value representing a range in which the presence of the target that is the observation target is predicted with the predicted value as the center. That is, here, at time t + Δt, it represents a frequency band in which the presence of the up-phase beat frequency U (t) x or the down-phase beat frequency D (t) x is predicted.

  The gate information is used in the correlation determining unit 24 of the up-phase tracking filter 18 and the down-phase tracking filter 19. For example, the up-phase tracking filter 18 extracts U (t) i included in the frequency band calculated as the gate as a candidate for the observed value U (t) x.

なお、上記においてＳ_ｋは残差共分散行列であって、Ｂｐ（ｔ）ｉはビート信号の周波数の予測値であり（Ｕｐ（ｔ）ｉ，Ｄｐ（ｔ）ｉ⊆Ｂｐ（ｔ）ｉ、ただしＵｐ（ｔ）ｉとＤｐ（ｔ）ｉはそれぞれアップフェーズとダウンフェーズのビート信号の周波数予測値である）、ｄはゲートの大きさを決めるパラメータである。具体的なｄの設定方法の例としては、次のようにする。すなわち、Ｂｔ（ｉ）の確率密度分布が、予測値Ｂｐｔ（ｉ）を中心とした正規分布に従うと近似すれば、式（２３）の左辺はカイ２乗分布で近似される。そこで、Ｂｔ（ｉ）がゲート内に得られる確率をどの程度にしたいかに応じて、カイ２乗分布に基づいてｄを設定するのである。 The frequency B (t) i of the beat signal observed in the gate satisfies the relationship given by equation (23). Note that the frequency U (t) i of the beat signal in the up phase and the frequency D (t) of the beat signal in the down phase satisfy U (t) i, D (t) i⊆B (t) i. Shall.

In the above, S _k is a residual covariance matrix, and Bp (t) i is a predicted value of the frequency of the beat signal (Up (t) i, Dp (t) i⊆Bp (t) i, Here, Up (t) i and Dp (t) i are frequency prediction values of up-phase and down-phase beat signals, respectively, and d is a parameter that determines the size of the gate. An example of a specific method for setting d is as follows. That is, if the probability density distribution of Bt (i) is approximated to follow a normal distribution centered on the predicted value Bpt (i), the left side of equation (23) is approximated by a chi-square distribution. Therefore, d is set based on the chi-square distribution according to how much the probability that Bt (i) is obtained in the gate is desired.

  Next, the operation of the gate information creation unit 51 will be described. After the phase determination process (corresponding to step P10 on the flowchart of FIG. 4) by the phase determiner 17 is completed, the gate information creation unit 51 performs the distance / speed prediction process (on the flowchart of FIG. 4). It corresponds to the start of (corresponding to step P11).

  The predicted distance value based on the up-phase beat signal at time t + Δt is Rpu (t) i, the predicted speed value is Vpu (t) i, the predicted distance value based on the down-phase beat signal is Rpd (t) i, and the predicted speed. Let the value be Vpd (t) i. First, the up-phase frequency prediction unit 52 reads Rpu (t) i and Vpu (t) i from the up-phase tracking result storage unit 41, and calculates a predicted value Upu (t + Δt) i of the beat frequency in the up phase. To do. Further, the down-phase frequency prediction unit 53 reads Rpu (t) i and Vpu (t) i from the up-phase tracking result storage unit 41, and calculates a predicted value Dpu (t + Δt) i of the beat frequency in the down phase. To do.

  Similarly, the down-phase frequency prediction 54 reads Rpd (t) i and Vpd (t) i from the down-phase tracking result storage unit 42, and predicts a beat frequency predicted value Dpd (t + Δt) i in the down phase. Is calculated. Further, the up-phase frequency prediction 55 reads Rpd (t) i and Vpd (t) i from the down-phase tracking result storage unit 42, and calculates a predicted value Upd (t + Δt) i of the beat frequency in the up-phase. .

Next, in the gate calculation units 56 and 57, the gate Guu (t + Δt) i centered on Upu (t + Δt) i from the equation (23),
Gate Gud (t + Δt) i centered at Upd (t + Δt) i,
A gate Gdu (t + Δt) i centered on Dpu (t + Δt) i,
A gate Gdd (t + Δt) i centered on Dpd (t + Δt) i is calculated.

  Subsequently, the gate creation unit 58 combines Guu (t + Δt) i, Gud (t + Δt) i, Gdu (t + Δt) i, and Gdd (t + Δt) i, and uses the up-phase gate Gu (t + Δt) i, which is used at time t + Δt, A down-phase gate Gd (t + Δt) is created. Specifically, for example, the gate Gu (t + Δt) i in the up phase is obtained as Guu (t + Δt) i∩Gud (t + Δt) i. Similarly, the gate Gd (t + Δt) in the down phase is obtained as, for example, Gdu (t + Δt) i∩Gdd (t + Δt) i. FIG. 12 is a conceptual diagram illustrating an example of an operation for obtaining a new gate by combining gates. As shown in the figure, a new gate may be extracted from a common portion of a plurality of gates to be combined.

By using these, for example, when the tracking performance of the down phase is good, (1) Only Gud (t + Δt) i is used as a gate.
(2) Use a gate Guu (t + Δt) i∪Gud (t + Δt) i that satisfies both Guu (t + Δt) i and Gud (t + Δt) i.
(3) Only the common part Guu (t + Δt) i∩Gud (t + Δt) i of Guu (t + Δt) i and Gud (t + Δt) i is used as a gate.
(4) A combination of the gates (1) to (3) above is executed.
Etc. method is used.

  As is apparent from the above, according to the radar apparatus of the fifth embodiment of the present invention, the gate information calculated from the beat signal obtained in the up phase, that is, the range in which the target is observed, and the beat signal obtained in the down phase The gate information calculated from the above is used to obtain new gate information, and this gate information is used in the measurement in the up phase and the down phase, so the gate information of the phase with better measurement accuracy is used. As a result, it is possible to improve the measurement accuracy of the relative distance and the relative speed of the external target.

  The radar apparatus according to the present invention is mounted on a moving body such as a vehicle, for example, detects an object as an external target, and measures its relative distance and relative speed.

It is a block diagram which shows the structure of the radar apparatus by Embodiment 1 of this invention. It is a block diagram which shows the detailed structure of a part of radar apparatus by Embodiment 1 of this invention. It is a figure for demonstrating the operation principle of the radar apparatus by Embodiment 1 of this invention. It is a flowchart which shows operation | movement of the radar apparatus by Embodiment 1 of this invention. It is a block diagram which shows the structure of the radar apparatus by Embodiment 2 of this invention. It is a block diagram which shows the structure of the radar apparatus by Embodiment 3 of this invention. It is a block diagram which shows the structure of the radar apparatus by Embodiment 4 of this invention. It is a block diagram which shows the detailed structure of a part of radar apparatus by Embodiment 4 of this invention. It is a flowchart which shows operation | movement of the radar apparatus by Embodiment 4 of this invention. It is a block diagram which shows the structure of the radar apparatus by Embodiment 5 of this invention. It is a block diagram which shows the detailed structure of a part of radar apparatus by Embodiment 5 of this invention. It is a conceptual diagram for demonstrating the method of gate preparation by Embodiment 5 of this invention.

Explanation of symbols

11 sensor,
12 A / D converter,
13 Frequency analyzer,
14 switches,
15 Time information memory,
16 sampling interval extraction unit,
17 phase detector,
18 Tracking filter for up-phase,
19 Tracking filter for down phase,
20 Tracking result storage unit,
21 Frequency pair selector,
22 Distance / speed deriving section,
23 Frequency prediction unit,
24 correlation determining unit,
25 Distance / speed smoothing section,
26 Distance / speed prediction unit,
31 predicted value determination unit,
32 predicted value determination unit,
33 sensor control unit,
41 Upphase tracking result storage unit,
42 Tracking result storage unit for down phase,
43 Integration Department,
44 Weight coefficient calculator,
45 Weight coefficient calculator,
46 Integrated calculation part,
51 Gate information creation part,
52 Up-phase frequency prediction unit,
53 Down-phase frequency prediction unit,
54 Down-phase frequency prediction unit,
55 Up-phase frequency prediction unit,
56 Gate calculator,
57 Gate calculator,
57 Gate creation part.

Claims (11)

Subjected to the up phase (frequency increase period) and down phase (frequency fall period) or Ranaru frequency modulated transmission signal, thereby emitting the transmission signal to an external target, receiving a reflected signal from the external target as a received signal A sensor to
A frequency analysis means for extracting a beat signal frequency observations of the transmission signal and the reception signal,
-Out based on the beat signal frequency observations the frequency analysis means is extracted by the up phase and the down phase, and the distance speed calculation means for calculating a distance and speed of the external target,
The external target using the distance and speed to calculate the smoothed value of the distance and speed of the external target, the distance of the outer target speed and beat after between predetermined time based on the smoothed value of the distance and speed of the external target and tracking means for calculating the predicted value of the signal frequency,
The distance of the outer target speed and the beat signal frequency of the predicted value, and includes a tracking result storage means for storing a smoothed value of the distance and speed of the external target,
The tracking means, when the transmission signal is migrated to the new up-phase or down phase, the tracking result storage means is already immediately before stored da down phase or up phase of the external target distance and speed A radar apparatus, wherein a predicted value of a distance and speed of an external target in the new up phase or down phase is calculated using a smooth value. Subjected to the up phase (frequency increase period) and down phase (frequency fall period) or Ranaru frequency modulated transmission signal, thereby emitting the transmission signal to an external target, receiving a reflected signal from the external target as a received signal A sensor to
A frequency analysis means for extracting a beat signal frequency observations of the transmission signal and the reception signal,
-Out based on the beat signal frequency observations the frequency analysis means is extracted by the up phase and the down phase, and the distance speed calculation means for calculating a distance and speed of the external target,
The external target using the distance and speed to calculate the smoothed value of the distance and speed of the external target, the distance of the outer target speed and beat after between predetermined time based on the smoothed value of the distance and speed of the external target and tracking means for calculating the predicted value of the signal frequency,
A tracking result storage means for individually storing with the predicted value of the distance of the outer target speed and the beat signal frequency to the up phase and the down phases,
Integration means for calculating an integrated prediction value by integrating the prediction values of the up phase and the down phase stored in the tracking result storage means;
A radar apparatus comprising: Beat signal frequency observation value extracted by the frequency analysis means;
Correlation determining means for determining the presence or absence of correlation with the beat signal frequency prediction value calculated by the tracking means,
The distance speed calculation means and the tracking means calculate a smooth value of the current distance and speed from the beat signal frequency observation value determined to have correlation by the correlation determination means, and based on the smooth value, 3. The radar apparatus according to claim 1, wherein each predicted value is calculated. The distance / velocity calculating means and the tracking means are distances of the external target stored in the tracking result storage means when the beat signal frequency observation value determined to have correlation by the correlation determination means does not exist. 4. The current distance, speed, and each predicted value are calculated by substituting the predicted values of velocity, beat, and beat signal frequency for the beat signal frequency observation value, respectively. The radar device described in 1. When the tracking unit calculates predicted values of a plurality of beat signal frequencies, the tracking unit includes a predicted value determination unit that determines whether the plurality of beat signal frequency predicted values meet a predetermined condition,
The tracking means replaces the beat signal frequency observation value corresponding to the beat signal frequency prediction value determined by the prediction value determination means not to meet the predetermined condition, and the tracking result storage means stores each of the tracking result storage means. The radar apparatus according to claim 3, wherein each predicted value after a predetermined time is calculated based on a predicted value. 6. The sensor control means for setting the resolution of the sensor to be smaller when the predicted value determining means determines that a predetermined condition is not met for the plurality of beat signal frequency predicted values. The radar device described in 1. The predicted value determination means further outputs the number of beat signal frequency predicted values that do not meet the predetermined condition for each of the up phase and the down phase,
The tracking unit selects a phase with a smaller number of the beat signal frequency predicted values output by the predicted value determination unit from an up phase and a down phase, and performs a tracking process only for the phase. The radar device according to claim 5 or 6. The integration unit calculates a smoothing error covariance matrix from the current distance, speed, and the predicted values, and weights the predicted values in the up phase and the down phase based on the smoothing error covariance matrix. The radar apparatus according to claim 2, wherein the integrated prediction value is calculated. The integration means calculates residual information from the beat frequency observation value and the beat frequency prediction value, weights each prediction value in the up phase and the down phase based on the residual information, and integrates the integration information. The radar apparatus according to claim 2, wherein a predicted value is calculated. The radar apparatus according to claim 9, wherein the integration unit calculates a time series of the residual information and weights each predicted value based on the time series of the residual information. Gate information creation means for creating a gate from predicted values of beat signal frequencies in the up phase and down phase stored in the tracking result storage means, and the correlation determination means includes an internal gate created by the gate information creation means. The radar apparatus according to claim 3, wherein a correlation between only the beat signal frequency observation value included in the signal and the beat signal frequency prediction value is determined.

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