JP3496606B2 - Radar equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radar device for detecting the position of an object reflecting a radar wave using a plurality of reception beams.

[0002]

2. Description of the Related Art Conventionally, a vehicle-mounted radar device (hereinafter referred to as "vehicle-mounted radar device") for detecting an object (obstacle or preceding vehicle) located in front of the vehicle for use in control of collision prevention or follow-up traveling. Is known). In such an on-vehicle radar device, it is important to be able to acquire the direction data for specifying the accurate positional relationship between the host vehicle and the target object in addition to the distance and the relative speed to the target object.

Therefore, for example, as shown in FIG.
The reception levels of radar waves (reflected waves) reflected by the target object M1 are respectively detected by a plurality of reception beams BM whose directions are different from each other, and the reception level distribution of the reflected waves obtained as the detection result is the most received. A method is known in which the direction in which the received beam from which a high level signal is obtained is directed is the direction of the target object. The scanning of the reception beam is performed by mechanically moving a single antenna or by sequentially switching and using a plurality of antennas having different beam directing directions.

[0004]

By the way, when the object to be detected is a vehicle, especially when an electromagnetic wave (millimeter wave, microwave, etc.) is used as the radar wave, the radar wave is reflected at various parts of the vehicle. , And the reflection position (car body, bumper,
The reflection intensity varies depending on the material of the license plate, glass, etc.). In other words, the in-vehicle radar device does not always receive the reflected wave from the same reflection position even if it is the reflected wave from the same vehicle, and the antenna receives it according to the positional relationship with the vehicle to be detected. The reflected position of the reflected wave on the vehicle changes variously, and as a result, the signal intensity distribution of the reflected wave changes every moment.

Moreover, in a vehicle-mounted radar device using a radar wave composed of electromagnetic waves, a reflected wave directly reflected from a vehicle and a different route (multipath) by being reflected on the road surface, etc.
The reflected wave that has passed through may be received at the same time, and if the phases of both signals deviate by exactly 180 °, they may cancel each other and the signal strength of the reflected wave may be greatly reduced.

When the signal intensity distribution of the reflected wave detected by the in-vehicle radar device is disturbed in this way, the signal intensity of the receive beam different from the receive beam in which the vehicle to be detected is mainly present is the maximum. There was a problem that the direction of the vehicle to be erroneously detected. Specifically, when the beam of the radar wave radiated from a certain point spreads in the range of the angle α, the beam width of the radar wave at a point distant from the point by the distance Y (orthogonal to the beam center direction and received). The width W in the direction along the beam arrangement direction can be calculated by the equation (1).

W = Y × sin α (1) For example, when the irradiation direction of the reception beam is set at 1 ° intervals, the distance between the centers of the beams is about 17 cm at 10 m, but about 100 m at 1.7m, that is,
It is about the same as the width of the lane.

That is, even if the reception beam specified as the presence of the vehicle is deviated by one beam, if the vehicle to be detected is in a relatively short distance, it is calculated from the azimuth data representing the irradiation direction of the reception beam. The error of the lateral position data is small, but the error of the lateral position data becomes large when the vehicle to be detected is at a relatively long distance.

Actually, assuming that the azimuth data θ as shown in FIG. 10A (provided that the front direction is 0 °) is obtained, the vehicle to be detected is at a short distance (Y is small). For a certain case and a long distance (Y is large), the lateral position data X representing the lateral position along the direction orthogonal to the front direction (however, the front position is the origin) is obtained. When,
In the case of a short distance, almost constant lateral position data X is obtained as shown in FIG. 10B, but in the case of a long distance,
As shown in FIG. 10C, the lateral position data X will change greatly.

As a result, the lateral position data of the preceding vehicle detected by the above-mentioned disturbance of the signal strength distribution during the automatic cruise control in which the preceding vehicle traveling in the same lane as the own vehicle is followed. If X changes greatly, it may be determined that the preceding vehicle is not on the own lane in some cases, and it may be impossible to continue following the vehicle.

In order to solve such a phenomenon, the detected lateral position data X is smoothed on the time axis using a low-pass filter or the like (see the dotted line in FIG. 10C) to obtain the lateral position data. It is also practiced to suppress a sharp change in X. However, if the value of the filter is set so that the behavior at a long distance is sufficiently stable, the responsiveness at a short distance deteriorates, and for example, detection of an interrupting vehicle (vehicle M in FIG. 9).
However, there is a problem in that the deceleration processing and the like performed in response to this interrupted vehicle cannot be effectively operated.

In order to solve the above problems, the present invention provides
In a radar device that detects the position of an object that has reflected radar waves using multiple reception beams, while ensuring responsiveness when detecting an object at a short distance, when detecting an object at a long distance The purpose is to improve the stability of the lateral position.

[0013]

According to another aspect of the present invention, there is provided a radar apparatus according to claim 1, wherein the receiving means irradiate each other within a scanning area centered on a preset specific direction. When a plurality of reception beams having different directions are formed and the radar wave reflected by the object is received for each of the reception beams, the azimuth calculation means determines the arrival direction of the radar wave based on the reception signal output from the reception means. In addition to calculating the azimuth data indicating the distance, the distance calculating means calculates the distance data indicating the distance to the object that reflected the radar wave.

Further, based on the azimuth data and the distance data calculated by the azimuth calculating means and the distance calculating means,
The lateral position calculation means calculates lateral position data that represents a position that is orthogonal to the specific direction and along the array direction of the reception beams, and the smoothing means inputs the lateral position data calculated by the lateral position calculation means into the input data. Then, the output data generated by suppressing the variation of the input data is generated, and the position of the object is specified by the distance data calculated by these distance calculation means and the smoothed lateral position data generated by the smoothing means. It outputs as position information for.

In particular, in the radar device of the present invention, the characteristic varying means, depending on the distance to the object calculated by the distance calculating means, the farther the distance is, the greater the degree of suppression of the variation of the input data becomes. The characteristics of the smoothing means are changed so that That is, according to the radar device of the present invention,
For an object at a short distance where the lateral position data does not change significantly, the degree of suppression of the variation of the lateral position data by the smoothing means is set to be small, so sufficient responsiveness can be ensured, On the other hand, for a long-distance object that does not require high-speed response, the smoothing means increases the degree of suppression of variation in lateral position data, so stable lateral position data can be obtained. You can

As a result, when the radar device of the present invention is mounted on a vehicle, various controls executed by the detection results of these objects (vehicles, etc.), for example, a warning for a cruise system for performing follow-up traveling and an interrupting vehicle are generated. It is possible to improve the control accuracy of the alarm system and the like.

Further, in the radar apparatus of the present invention, the smoothing means includes a filter means for generating output data by weighted addition of the input data and the past output data, the smoothing means for a preset reference value If the deviation of the input data to is larger than the preset comparison value,
There is provided guard means for supplying preset limit data as input data to the filter means instead of input data to the smoothing means .

The characteristic varying means may be, for example,
As described in Item 6, the further the distance to the object is, the lighter the weighting of the input data of the weighted addition performed by the filter means may be made, and the item may be configured to be lighter.
As described above, the comparison value used by the guard means may be reduced as the distance to the object increases .

As the reference value used by the guard means, the previous output data may be used as in claim 2 , or the input data and the past output data may be used as in claim 3 . A weighted addition value may be used. The weighted addition value may be an average value of the input data and the output data of the past multiple times.

Further, as the guard value used by the guard means as claimed in claim 4, wherein, to the deviations from the reference value may be used a value limited by comparison value, as claimed in claim 5, wherein , The previous output data may be used as it is.

[0021]

[0022]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] FIG. 1 is a block diagram showing the overall structure of an on-vehicle radar device for obstacle detection according to the first embodiment of the present invention.

As shown in FIG. 1, the in-vehicle radar device 2 of this embodiment is radiated from a transmitter 12 that transmits a radar wave modulated to a predetermined frequency according to the modulation signal Sm, and is radiated by an obstacle. A transmitter / receiver 10 including a receiver 14 for receiving a radar wave reflected by an object and a transmitter 12 are provided with a modulation signal Sm, and an obstacle is generated based on an intermediate frequency beat signal B output from the receiver 14. The signal processing unit 20 executes processing for detecting an object.

In the present embodiment, the transmitting / receiving unit 1 is used to detect an obstacle in front of the vehicle by the device 2.
0 is attached to the front of the vehicle, and the signal processing unit 20
It is installed at a predetermined position in or near the passenger compartment.
Here, first, the transmitter 12 is a voltage controlled oscillator (VCO) 12 that generates a high frequency signal in the millimeter wave band as a transmission signal.
b, a modulator (MOD) 12a for converting the modulation signal Sm into the adjustment level of the voltage controlled oscillator 12b and supplying the voltage controlled oscillator 12b to the voltage controlled oscillator 12b, and a transmission signal from the voltage controlled oscillator 12b for power distribution to each receiver 14 , 16 for power supply (COUP) 12c for generating local signals
And a transmission antenna 12d that radiates a radar wave according to a transmission signal.

The transmitting antenna 12d detects a range in which the radar device 2 can detect an obstacle due to its transmitting beam (for example, in the present embodiment, the traveling direction of the vehicle is set to 0).
The one that can cover the entire range of ± 15 ° is used. Further, the receiver 14 includes a reception antenna 14a that receives a radar wave, a mixer 14b that mixes a reception signal from the reception antenna 14a with a local signal from the power distributor 12c, and a preamplifier that amplifies the output of the mixer 14b. 14c, a low-pass filter 14d that removes unnecessary high-frequency components from the output of the preamplifier 14c, and extracts the beat signal B that is the difference component of the frequencies of the transmission signal and the reception signal, and the beat signal B to the required signal level. It is composed of a post-amplifier 14e for amplifying.

The receiving antenna 14a is used to form a receiving beam having a strong directivity (a beam width of about 3 ° in this embodiment), and moreover, the irradiation direction of the receiving beam is along a horizontal plane. It is configured to be rotatable in any direction. Then, the reception antenna 14a is provided in the transmission / reception unit 10 according to a control signal C3 from the signal processing unit 20 at a predetermined step angle (for example, 1 in the present embodiment).
A scanning drive device 16 is provided for sequentially switching the irradiation direction of the reception beam in units of °) to perform scanning within the above-described detection range.

On the other hand, the signal processing unit 20 is activated by the activation signal C1 to generate the triangular wave modulation signal Sm, and the activation signal C2 to activate the beat signal B from the receiver 14. A / D converter 24 for converting to data D, CPU 26a, ROM 26b, R
A data collection process mainly composed of the AM 26c, which collects data by sending start signals C1 and C2 and a control signal C3 to operate the triangular wave generator 22, the A / D converter 24, and the scan driver 16. , And a well-known microcomputer (hereinafter referred to as “microcomputer”) 26 that executes an obstacle detection process for detecting an obstacle based on the digital data D collected by the data collection process, and a high speed based on a command from the microcomputer 26. The arithmetic processing unit 28 executes an operation of Fourier transform (FFT).

Next, the data collection process executed by the CPU 26a of the microcomputer 26 will be described. In this data collection process, first, the control signal C3 is transmitted to move the reception antenna 14a to the initial position (for example, the position where the reception beam comes to one end within the detection range). Subsequently, the activation signal C1 is transmitted to activate the triangular wave generator 22, and the activation signal C2 is transmitted to activate the A / D converter 24. Then, the modulation signal Sm generated by the triangular wave generator 22 is input to the voltage controlled oscillator 12b via the modulator 12a, and the voltage controlled oscillator 12b predetermined according to the rising slope of the triangular waveform of the modulated signal Sm. Modulation is performed such that the frequency increases at a rate of (hereinafter, this section is referred to as the "upstream modulation section"), and the frequency decreases according to the subsequent downward gradient (hereinafter, this section is referred to as the "downstream modulation section"). The transmitted signal (center frequency f0, frequency modulation width ΔF, modulation cycle 1 / fm) is output. That is, the in-vehicle radar device 2 of this embodiment operates as a so-called FMCW radar.

A radar wave corresponding to the frequency-modulated transmission signal is transmitted from the transmitter 12, and the radar wave reflected by the obstacle is received by the receiver 14. Then,
In the receiver 14, the beat signal B is generated by mixing the reception signal output from the reception antenna 14 a and the transmission signal from the transmitter 12. It should be noted that the reception signal is delayed with respect to the transmission signal by the time for the radar wave to make a round trip to the obstacle, and if there is a relative velocity with the obstacle, the reception signal undergoes Doppler shift accordingly. . Therefore, the beat signal B contains the delay component fr and the Doppler component fd.

The beat signal B is A / D converted by the A / D converter 24 activated by the activation signal C2, and the digital data D obtained as a result of the A / D conversion is sequentially stored in the RAM 26c. By the way, the A / D converter 24 is activated by the activation signal C2 together with the activation of the triangular wave generator 22 as described above, and performs the A / D conversion a predetermined number of times while the modulation signal Sm is being output. I am supposed to do it.
That is, the first half half of the data becomes the upstream modulation section data corresponding to the upstream modulation section of the transmission signal, and the second half half of the data becomes the downstream modulation section data corresponding to the downstream modulation section of the transmission signal.

When the processing for one cycle of the modulation signal Sm is completed in this way, the control signal C3 is output to move the irradiation direction of the reception beam of the reception antenna 14a by one step by the scanning drive device 16. Subsequently, by sending the activation signals C1 and C2, the above processing is repeatedly executed. Then, when the scanning of the reception beam is completed over the entire detection range, the obstacle detection processing is started, and thereafter, this processing is repeatedly executed in parallel with the obstacle detection processing.

Next, the obstacle detection process will be described with reference to the flowchart shown in FIG. As shown in FIG. 2, when this process is activated, first, in step (hereinafter simply referred to as “S”) 110, the digital data D written in the RAM 26c is sequentially read, and each received beam and each modulation are performed. The frequency analysis of the beat signal B is performed by executing the calculation of the fast Fourier transform (FFT) for each unit (upstream modulation unit / downstream modulation unit). Note that the data input to the arithmetic processing unit 28 is subjected to a well-known window process using a Hanning window, a triangular window, or the like in order to suppress side lobes appearing in the FFT calculation, and then is input to the arithmetic processing unit 28. The frequency spectrum data sent and subjected to the FFT operation and obtained as the operation result is obtained as a complex vector for each frequency.

In the subsequent S120, the peak of the frequency spectrum is detected based on the absolute value of the complex vector, that is, the amplitude of the frequency component indicated by the complex vector, and the frequency is detected as the beat frequency (fu in the up-modulation section, down-modulation section). Then, the amplitude is compared between the respective reception beams with respect to the detected frequency component, and the peak reception beam is specified from the signal strength distribution. Then, the irradiation direction of the specified reception beam is set as azimuth data θ representing the arrival direction of the radar wave, that is, the direction in which the obstacle exists. However, the azimuth data θ is represented by a positive value in the clockwise direction and a negative value in the counterclockwise direction with the traveling direction in front of the vehicle being 0 °. In addition, this processing is performed for each modulator data.

In step S130, if there are a plurality of peak frequency components, that is, if a plurality of obstacles are detected, the upstream modulator and the downstream modulator correctly combine frequency components based on the same obstacle. Execute the pairing process. This pairing processing is performed, for example, by combining the products in the order of increasing frequency or combining the products having almost the same signal strength. In this pairing process, the identity is also determined by comparing the information with the obstacle information detected when the process was last started. Since the determination of identity is a known technique and is not directly related to the present invention, its description is omitted.

At S140, the distance data Y to the obstacle is calculated from the beat frequencies fu and fd of the ascending portion and the descending portion using the following equation (2), and the obstacle data is calculated using the equation (3). Relative speed data V with respect to the object is calculated. Y = (c / (8 · ΔF · fm)) · (fu + fd) (2) V = (c / (4 · f0)) · (fu-fd) (3) In the subsequent S150, for each obstacle From the distance data Y and the azimuth data θ, the lateral position data X, which represents the lateral position orthogonal to the front direction of the vehicle and along the horizontal direction, is calculated using the following equation (4). However, the lateral position data calculated in this step will be referred to as "raw lateral position data" below.
Shall be called.

X = Y · sin θ (4) In subsequent S160, the past lateral position data Xn-1 of the same obstacle specified by the identity determination with the past data performed at the time of pairing in S130. , Xn-2,
Is used to execute the filtering process for suppressing the variation of the data, and the lateral position data Xn in which the variation is suppressed, that is, the smoothed lateral position data Xn is obtained in S170.
The distance data Y and the relative velocity data V calculated at 40 are output together with the process, and the present process is terminated.

The lateral position data X calculated in this way
The n, the distance data Y, and the relative speed data V are used to determine the presence or absence of danger in a separately executed determination process. When it is determined that there is a danger, for example, an alarm device (not shown) sounds. It is used for processing such as to notify the driver of a danger and automatic cruise control for traveling following a preceding vehicle traveling in the same lane as the own vehicle.

The filtering process executed in S160 will be described below with reference to the flowchart shown in FIG. As shown in FIG. 3, when this process is activated, first, in S210, the distance data Y calculated in the previous S140 is acquired, and in the subsequent S220, the acquired distance data Y is preset. It is determined whether it is smaller than the lower limit value YL. If the distance data Y is smaller than the lower limit value YL (Y <YL), the process proceeds to S240, the preset first limit value LM1 is set as the determination value Xth, and the process proceeds to S270.

On the other hand, if the distance data Y is greater than or equal to the lower limit value YL, then the flow shifts to S230, where it is determined whether or not the distance data Y is greater than the upper limit value YH. If the distance data Y is larger than the upper limit value YH, the process proceeds to S250 and the preset second limit value LM2 is set to the determination value Xth.
Is set and the process proceeds to S270.

If the distance data Y is less than or equal to the upper limit value YH, the flow shifts to S260, the limit value f (Y) corresponding to the distance data Y is obtained by the following equation (5), and this limit value f (Y) is set as the determination value Xth, and the process proceeds to S270.

[0041]

[Equation 1]

That is, in S210 to S260, as shown in FIG.
As shown in (a), if the obstacle is closer to the lower limit value YL, the first limit value LM1, and if the obstacle is farther from the upper limit value YH, the second limit value LM2, and the lower limit value YL and the upper limit value YH. If there is a space, the limit value f (Y) determined by the distance Y is set as the determination value Xth.

Then, in S270, the lateral position data Xn-i (where i = 1 to 3 in this embodiment) calculated when the process is started i times ago is acquired, and the subsequent S28.
At 0, the value (X-Xn-1) obtained by subtracting the previous lateral position data Xn-1 acquired in S270 from the raw lateral position data X calculated in S150 is set in the processes of S210 to S260. It is determined whether or not it is greater than the determined threshold value Xth,
If it is larger than the judgment value Xth, the process proceeds to S300, the raw lateral position data X is replaced with the limit value (Xn-1 + Xth), and S3 is performed.
Go to 20.

On the other hand, if a negative determination is made in S280,
The process proceeds to S290, and this time, the subtraction value (X-Xn-1
) Is smaller than the judgment value −LM, and if smaller than the judgment value −LM, the process proceeds to S310, the raw lateral position data X is replaced with the limit value (Xn−1 −Xth), and S32 is executed.
Go to 0. If a negative determination is made in S290 as well, that is, if the deviation of the raw lateral position data X from the previous lateral position data Xn-1 is within the judgment value (| X-Xn-1 | ≤Xth). Moves to S320 as it is without limiting the raw lateral position data X.

Then, in step S320, the current lateral position data Xn is calculated from the result of weighted addition with the past lateral position data using the following equation (6), and this processing ends.

[0046]

[Equation 2]

However, in this embodiment, the coefficients A0 to A3 of the lateral position data X and Xn-1 to Xn-3 are set as follows, respectively. (A0, A1, A2, A3) = (0.5, 0.16,
0.16, 0.16) Further, when the number of past lateral position data Xn-1 to Xn-3 regarding the same obstacle as the raw lateral position data X is less than 3, all the past lateral position data X existing at that time The average value with the lateral position data or the raw lateral position data X may be used as it is as the lateral position data Xn of this time.

As described above, in the on-vehicle radar device 2 of this embodiment, by executing the filtering process, as shown in FIG. 4B, the obstacles P1 and P3 located nearer to the lower limit value YL. For the first limit value L
M1, obstacles P3, P6 located farther than the upper limit value YH
For the obstacles P2 and P4 located between the second limit value LM2 and the lower limit value YL and the upper limit value YH, the limit value f (Y) determined by the respective distances is set as the determination value Xth. It is supposed to do. Moreover, the deviation of the raw lateral position data X from the previous lateral position data Xn-1 is larger than the set judgment value Xth (| X−X
In the case of (n-1 |> Xth), the value of the raw lateral position data X is limited according to the previous lateral position data Xn-1 and the judgment value Xth.

Therefore, when the horizontal position data Xn of this time is calculated, the raw horizontal position data X is changed to the past horizontal position data Xn-.
Not only is it simply smoothed by weighted addition with i (S320), even if the raw lateral position data X is the same, for example, for obstacles P1, P2, P3, its distance data Y is The larger the value, the more the value of the raw lateral position data X is limited so that the variation from the previous lateral position data Xn-1 becomes smaller.

As a result, the in-vehicle radar device 2 of this embodiment is
According to the above, when the obstacle exists at a relatively distant position, the variation can be sufficiently suppressed, and stable lateral position data Xn can be obtained. For example, the stability of the follow-up control performed at the time of auto-cruise. When the obstacle is located at a relatively close position, the behavior of the obstacle can be detected with high responsiveness. For example, an alarm can be generated when there is an interrupting vehicle. The control such as braking can be promptly executed, and the traveling safety can be improved.

That is, regardless of whether the obstacle exists at a distant position or at a near position, the lateral position data Xn suitable for control corresponding to each position can always be obtained. In the present embodiment, the receiver 14 and the scan driving device 16 correspond to the receiving means of the present invention. Further, S120 is an azimuth calculation means, and S14
0 is the distance calculation means, S150 is the lateral position calculation means, S16
0 is a smoothing means, S210 to S260 are characteristic changing means,
S270 to S310 correspond to the guard means, and S320 corresponds to the filter means. [Second Embodiment] Next, a second embodiment will be described.

In the in-vehicle radar device 2 of this embodiment, the first
Since only a part of the filtering process is different from the embodiment, only the different filtering process will be described. FIG. 5 is a flowchart showing the content of the filtering process in this embodiment.
However, steps having the same contents as the filtering process of the first embodiment are given the same step numbers.

As shown in FIG. 5, when this process is started, first, as in the case of the first embodiment, the distance data Y
The determination value Xth is set (S210 to S260) and the past lateral position data Xn-i is acquired (S270). Then, in subsequent S285, the deviation | X-Xn-1 | between the raw lateral position data X calculated in S150 and the previous lateral position data Xn-1 acquired in S270 is S21.
0 to S260, it is judged whether or not it is larger than the judgment value Xth set, and if the deviation is larger than the judgment value (| X-Xn-
1 |> Xth), shift to S305, and raw lateral position data X
Replace the value of with the value of the previous horizontal position data Xn-1 and S
Moving to 320.

On the other hand, if the deviation is less than or equal to the judgment value, (| X-
Xn-1 | ≦ Xth), without restricting the value of the raw lateral position data X, the process directly proceeds to S320. And S32
0, the raw lateral position data X and
The present lateral position data Xn is obtained by performing weighted addition with the past lateral position data Xn-i, and this processing is ended.

That is, in the in-vehicle radar device 2 of this embodiment, as shown in FIG. 6, when the deviation between the raw lateral position data X and the previous lateral position data Xn-1 is larger than the judgment value Xth (obstacle P2 , P3, P4), the raw lateral position data X is not used, and the previous lateral position data Xn-1 is used instead.
Is used. The determination value Xth is the first
Just as in the case of the embodiment, it is variably set according to the distance data Y.

Therefore, the in-vehicle radar device 2 of the present embodiment
According to the above, the same effect as that of the first embodiment can be obtained. In the present embodiment, S210 to S260 are characteristic changing means, S270 to S305 are guard means, and S3.
20 corresponds to the filter means. [Reference Example] Next, a reference example will be described.

In the on-vehicle radar device 2 of this reference example , the first
Since only a part of the filtering process is different from the embodiment, only the different process will be described. FIG. 7 is a flowchart showing the content of the filtering process in this embodiment. However, steps having the same contents as the filtering process of the first embodiment are given the same step numbers.

As shown in FIG. 7, when this process is started, first, as in the case of the first embodiment, the distance data Y
Is acquired, and the acquired distance data Y is compared with the preset lower limit value YL and upper limit value YH (S21).
0-S230). Then, when the distance data Y is smaller than the lower limit value YL (S220-YES), the process proceeds to S245, and the weighting factors A0 to A3 used in the weighting addition performed in S320 are set as in (7). ,Also,
When the distance data Y is larger than the upper limit value YH (S230-
If YES, the process proceeds to S255, in which the weighting coefficients A0 to A3 are also set as in (8), and the distance data Y is equal to or more than the lower limit value YL and equal to or less than the upper limit value YH (S).
230-NO), the process proceeds to S265, and the weighting factors A0 to A3 are similarly set as in (9).
Proceed to 70.

[A0, A1, A2, A3] = [0.7, 0.1, 0.1, 0.1] (Y <YL) (7) [A0, A1, A2, A3] = [0.25,0.25,0.25,0.25] ( (Y> YH) (8) [A0, A1, A2, A3] = [0.5, 0.16,0.16,0.16] (YL ≦ Y ≦ YH) (9) In S270, past lateral position data Xn-i is acquired. In subsequent S320, the weighting factors A0 to A3 set in S210 to S265, the raw lateral position data X calculated in S150, and the past lateral position data Xn-1 to Xn-3 acquired in S270. Based on the above, weighted addition is performed according to (6) shown above to calculate the horizontal position data Xn of this time, and this processing ends.

That is, in the filtering process of the present reference example , instead of limiting the variation of the raw lateral position data X by variably setting the determination value Xth according to the distance data Y, the weighting coefficient A0 is set according to the distance data Y. The contents of weighted addition are changed by variably setting A3. Specifically, as the distance data Y is smaller, the weight of the raw lateral position data X is increased so that the lateral position data Xn with good responsiveness can be obtained, and as the distance data Y is larger, the past lateral position data Xn can be obtained. The weight of the position data Xn-i is increased so that the temporal variation of the lateral position data Xn can be sufficiently suppressed.

Therefore, according to the on-vehicle radar device 2 of the present reference example , the same effect as that of the first embodiment can be obtained. In this reference example , S210 to S265 correspond to the characteristic changing means, and S320 corresponds to the filter means.

Although some embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be implemented in various modes. For example, in each of the first to second embodiments, the filtering process is performed on the lateral position data, but the filtering process is performed on the azimuth data θ, and the smoothed azimuth obtained as a result is obtained. Data θ
May be used to calculate the lateral position data.

In this case, as shown in FIG. 8, the obstacle detection processing is executed in the order of the lateral position data calculation (S150) and the filtering processing (S160) as compared with the case of the first embodiment. On the contrary, the filtering process (S155) and the lateral position data calculation (S165) may be executed in this order.

The details of the filtering process (S155) can be the same as those shown in FIGS. 3, 5 and 7. However, in this case, the value X related to the lateral position data,
Xth and Xn-i are the values relating to azimuth data θ, θth and θn-i
Should be replaced with In this case, S155 corresponds to the smoothing means and S165 corresponds to the lateral position calculating means.

Further, the weighting factors A0 to A3, the lower limit value YL used for comparison with the distance data Y, the upper limit value YH, and the limit values LM1, LM2 used for the judgment values Xth, θth.
The f (Y) and f (θ) are not limited to those described above, and may be appropriately optimized and set according to the control to be realized.

Further, in the above embodiment, beam scanning is performed by mechanically operating a single antenna, but a plurality of receiving beams are simultaneously formed using a plurality of antennas. However, the present invention may be applied to a device such as a DBF that forms beams by calculation from data that is simultaneously received.

Furthermore, in the first and second embodiments, it is determined whether or not the raw position data X is limited according to the deviation of the raw lateral position data X from the previous lateral position data Xn-1. Instead of the lateral position data Xn-1, the average value or weighted addition value of the lateral position data Xn-i (i = 1 to m) obtained a plurality of times in the past may be used.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of an in-vehicle radar device according to an embodiment.

FIG. 2 is a flowchart showing the contents of obstacle detection processing in the first embodiment.

FIG. 3 is a flowchart showing the content of a filtering process in the first embodiment.

FIG. 4 is an explanatory diagram showing setting of a determination value Xth and changes in lateral position data by the processing of FIG.

FIG. 5 is a flowchart showing the contents of filtering processing in the second embodiment.

FIG. 6 is an explanatory diagram showing a change in lateral position data by the processing of FIG.

FIG. 7 is a flowchart showing the contents of filtering processing in the reference example .

FIG. 8 is a flowchart showing the contents of obstacle detection processing in another embodiment.

FIG. 9 is a schematic diagram illustrating an operation of an on-vehicle radar device that detects an obstacle using a plurality of reception beams.

FIG. 10 is an explanatory diagram showing a problem of the conventional device.

[Explanation of symbols]

2 ... In-vehicle radar device, 10 ... Transceiver unit, 12 ... Transmitter,
12a ... Modulator, 12b ... Voltage controlled oscillator, 12c ... Power distributor, 12d ... Transmitting antenna, 14 ... Receiver, 14
a: receiving antenna, 14b ... mixer, 14c ... preamplifier, 14d ... low pass filter, 14e ... postamplifier,
16 ... Scan drive device, 20 ... Signal processing part, 22 ... Triangular wave generator, 24 ... A / D converter, 26 ... Microcomputer, 28 ... Arithmetic processing device

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01S ⁷ /00-7/42 G01S 13/00-13/95

Claims (7)

(57) [Claims] 1. A reception device that forms a plurality of reception beams having different irradiation directions in a scanning region centered on a preset specific direction, and receives a radar wave reflected by an object for each reception beam. Means, azimuth calculation means for calculating azimuth data representing the arrival direction of the radar wave based on the reception signal output from the reception means, and the radar wave based on the reception signal output from the reception means. Based on the azimuth data and the distance data calculated by the azimuth calculation means and the distance calculation means, the distance calculation means for calculating the distance data representing the distance to the reflected object and the direction orthogonal to the specific direction and Lateral position calculating means for calculating lateral position data representing a position along the array direction of the reception beam, and lateral position data calculated by the lateral position calculating means as input data, Smoothing means for generating output data in which variation of the data is suppressed, the distance data calculated by the distance calculating means, and the smoothed lateral position data generated by the smoothing means, In the radar device that outputs as position information for specifying the position of, the degree of suppression of the variation of the input data is increased as the distance is increased according to the distance to the object calculated by the distance calculation means. A characteristic changing means for changing the characteristic of the smoothing means is provided so as to be large , and the smoothing means is configured by weighting addition of input data and past output data.
Filter means for generating output data, and input to the smoothing means for a preset reference value
If the data deviation is larger than the preset comparison value,
In this case, the preset data is set instead of the input data to the smoothing means.
The restricted data as input data to the filter means
Radar apparatus, characterized by comprising a guard unit for supplying Te. 2. The radar device according to claim 1 , wherein the previous output data is used as the reference value used by the guard means. 3. The radar device according to claim 1 , wherein a weighted addition value of input data and past output data is used as the reference value used by the guard means. 4. The radar device according to claim 1 , wherein a value obtained by limiting a deviation from the reference value by the comparison value is used as the guard value used by the guard means. A characteristic radar device. 5. The radar device according to claim 1 , wherein the previous output data is used as the guard value used by the guard means. 6. The radar device according to claim 1 , wherein the characteristic varying means reduces the weighting of the input data of the weighted addition performed by the filtering means as the distance to the object increases. A radar device characterized by: 7. The radar device according to claim 1 , wherein the characteristic varying unit reduces the comparison value used by the guard unit as the distance to the object increases. Radar device.