JP2010112829A - Detection device, method and program - Google Patents

Abstract

An object of the present invention is to accurately detect the traveling direction and speed of an object based on detection position information detected at random.
A detection position specifying unit 81 specifies a relative detection position of an object based on a speed, a distance, and an angle at a detection position of the detected object, and a content number counting unit 86 A specific detection position is associated with the time, and plotted on a two-dimensional plane set by an axis indicating the detection position in the horizontal direction and an axis indicating the distance to the detection position in the traveling direction. Count the number of detected detection positions included in the frame for each rotation angle while rotating the frame with the shape on the plane that the head part is expected to pass within the predetermined time at the predetermined rotation angle, and the direction The determination unit 87 determines the presence position where the object exists and the traveling direction based on the rotation angle of the frame that maximizes the number of plotted plots. The present invention can be applied to a vehicle safety device.
[Selection] Figure 2

Description

  The present invention relates to a detection apparatus, method, and program, and more particularly, to a detection apparatus, method, and program that can detect the traveling direction and speed of an approaching object.

  2. Description of the Related Art Conventionally, a two-frequency CW (Continuous Wave) type sensor is known as a sensor for measuring the relative speed and distance between a host vehicle and another vehicle (see, for example, Patent Documents 1 and 2). That is, this two-frequency CW sensor detects the frequency (hereinafter referred to as the Doppler frequency) and phase of a Doppler signal with respect to the received carrier wave, and uses these to detect the relative speed between the vehicle and other vehicles. Measure distance.

  As a sensor for measuring an angle indicating a relative position between the own vehicle and another vehicle, a monopulse type sensor is known.

  In this way, the distance between the host vehicle and the other vehicle is measured using the two-frequency CW sensor, and the angle between the host vehicle and the other vehicle is measured by the monopulse sensor, so that there is an approaching other vehicle. It is possible to detect the position to perform.

Japanese Patent No. 3203600 JP 2004-69693 A

  By the way, it is known that the detection position varies within the vehicle existence range in the case of a radar that estimates the distance by the above-described two-frequency CW method and estimates the angle by the monopulse method.

  Therefore, conventionally, when detecting the speed, distance, and direction of a vehicle approaching by the reflected wave from an on-vehicle radar and pre-detecting the possibility of collision, the speed information and the detected position information are filtered. In addition, the speed vector was estimated to estimate the position of the vehicle that actually exists. In this filter, it is necessary to foresee that the output variation shows a constant distribution. For example, the Kalman filter is based on the premise that the output variation shows a Gaussian distribution.

  However, in the case of radio waves reflected from a vehicle, the distribution is not necessarily determined by noise or S / N ratio (Signal to Noise Ratio). In other words, the detected coordinates (radio wave reflection center) are determined by the positional relationship between the radar and the vehicle and the radio wave interference state determined by the vehicle outer shape. However, it will be random variation, and in order to estimate the center path of the detected object, even if a low-pass filter or Kalman filter is passed through the obtained detection result, an accurate result can be obtained. I can't.

  For this reason, in the method using the filter, it is sometimes impossible to specify the exact vehicle position from the detection position by the radio wave.

  The present invention has been made in view of such a situation, and makes it possible to detect at least one of a traveling direction and a speed of an approaching object based on a position detection result of the approaching object.

  A detection device according to one aspect of the present invention is a detection device that detects an object, and includes a transmission unit that transmits a transmission signal by irradiating a radio wave in a predetermined direction, and a transmission signal transmitted by the transmission unit. Of the radio waves, a reflected radio wave is received, a reception unit that generates a reception signal from the received radio wave, and a reception signal generated by the reception unit is sampled for a predetermined period of time. A detecting means for detecting a speed, a distance, and an angle; a position specifying means for specifying a relative detection position of the object based on the distance and angle of the object detected by the detecting means; and the position specifying means. Plotting means for plotting the specified detection position on a two-dimensional plane, frame setting means for setting a frame, and rotating the frame at a predetermined rotation angle Therefore, at least one of the existence position of the object and the traveling direction is determined based on a predetermined determination method using a plurality of plotted detection positions included in the frame for each rotation angle. Direction determining means.

  The object may be a vehicle.

  The transmission unit is, for example, a transmission unit, and can transmit a transmission signal by irradiating a predetermined range including a range near a predetermined distance in a predetermined direction near the back of the vehicle.

  The receiving means is, for example, a receiving unit that receives and receives a reflected radio wave from a transmission signal in a predetermined direction close to a predetermined distance in a predetermined direction near the back of the vehicle. A reception signal can be generated from radio waves.

  The detection means is, for example, a Doppler frequency calculation unit, a distance calculation unit, and an angle calculation unit, and based on the received signal, the received signal is sampled at a predetermined cycle by FFT to determine the speed, distance, and angle at the detection position. Can be detected.

  The position specifying unit is, for example, a detection position specifying unit, and can specify the detection position of an object, that is, a vehicle based on the speed, distance, and angle.

  The plotting unit is, for example, a content number counting unit, plots the detection position on the two-dimensional plane of the detection position of the object stored in the detection position storage unit, and the frame setting unit plots the detection position with respect to the traveling direction of the vehicle. The number of plotted detection positions included in the frame is counted for each rotation angle while rotating the frame indicating the set range that is swept at a predetermined speed for each predetermined rotation angle.

  The direction determining means is, for example, a direction determining means, and determines the traveling direction of the vehicle based on the maximum frame rotation angle among the count values for each frame rotation angle by the plotting means. At this time, the center position of the frame is determined as the position where the vehicle exists. Although it is known that the detection position varies randomly by this process, even if the detection position varies randomly, the position of the frame having the rotation angle with the largest number of detection positions that are considered to be present is determined by the vehicle's path of travel. Therefore, it is possible to appropriately determine the vehicle location. As a result, it is possible to accurately determine the presence or absence of a collision from the exact position of the vehicle, and in a situation where a collision is expected to occur, it is possible to accurately perform a preliminary collision operation. It becomes possible to improve safety.

  Based on the presence position determined by the direction determining means and the traveling direction, the speed vector setting means for setting the speed vector of the object, and the speed vector set by the speed vector setting means at the set time A speed vector storage means for storing the data in association with each other and a correction means for correcting the speed vector set at the current time based on the speed vector stored at the past time by the speed vector storage means are further included. be able to.

  The speed vector setting unit is, for example, a vector setting unit, the speed vector storage unit is, for example, a vector storage unit, and the correction unit is, for example, a vector correction unit, which is obtained by the speed vector setting unit. The current speed vector is corrected from the past speed vector information stored in the speed vector storage unit in association with the time information. For this reason, it is possible to accurately recognize the presence position and the moving direction of the vehicle, so that it is possible to accurately determine the presence or absence of a collision and to improve the safety at the time of the collision.

  When the speed of the vehicle is higher than a predetermined speed and the position of the vehicle is within a predetermined range, a preliminary collision operation executing means for executing a preliminary collision operation can be included.

  The collision preliminary motion execution means is, for example, a collision preliminary motion control unit, and a vehicle approaching from information on the vehicle location determined by the direction determination unit and the vehicle speed calculated by the Doppler frequency calculation unit. When there is a possibility of a collision, a preliminary operation in preparation for the collision can be executed, and when provided in the vehicle, safety at the time of the collision can be improved.

  Based on the detection position plotted on the plane, the vehicle presence position, and the traveling direction, the noise corresponding to the variation in the plotted detection position and the intensity of the radio wave received by the receiving means Further, an estimation means for estimating the size of the detected vehicle from the variation estimated by the above can be included.

  When the size of the vehicle estimated by the estimation unit is larger than a predetermined size, the collision preliminary motion execution unit may decrease the predetermined speed and set the predetermined range wide. In addition, when the speed of the object is higher than the predetermined speed and the presence position is in the predetermined range, a collision preliminary operation can be executed.

  The estimation means is, for example, a vehicle estimator, and includes variations in the detected detection positions plotted, variations due to noise estimated from received signal strength, vehicle location, and vehicle size detected from the traveling direction. By estimating the vehicle case of the approaching vehicle, the judgment criterion of the presence or absence of a collision according to the vehicle case is switched, and the preliminary collision operation when there is a possibility of a collision is switched according to the vehicle case Therefore, it is possible to determine the collision according to the vehicle case and the collision preliminary operation according to the vehicle case, and as a result, it is possible to improve the safety at the time of the collision.

  A detection method according to one aspect of the present invention is a detection method of a detection device that detects an object, and is transmitted by a transmission step of transmitting a transmission signal by irradiating a radio wave in a predetermined direction, and the processing of the transmission step. A reception step of receiving a reflected radio wave from the received radio wave and generating a reception signal from the received radio wave, and sampling the reception signal generated by the reception unit for a predetermined time A detection step for detecting the speed, distance, and angle of the object, and a position specifying step for specifying a relative detection position of the object based on the distance and angle of the object detected by the detection means; A plotting step for plotting the detection position specified by the processing of the position specifying step on a two-dimensional plane; and a frame for setting a frame The presence of the object based on a predetermined determination method using a plurality of plotted detection positions included in the frame for each rotation angle while rotating the frame at a predetermined rotation angle. A direction determining step for determining at least one of the presence position and the traveling direction, and a direction determining step for determining the existing position of the object and the traveling direction.

  A program according to one aspect of the present invention includes a transmission step of transmitting a transmission signal by irradiating a radio wave in a predetermined direction to a computer that controls a detection device that detects an object, and a transmission transmitted by the processing of the transmission step. By receiving a reflected radio wave out of radio waves as a signal and generating a received signal from the received radio wave, and sampling the received signal generated by the receiving means for a predetermined time A detection step for detecting the speed, distance, and angle of the object; a position specifying step for specifying a relative detection position of the object based on the distance and angle of the object detected by the detection means; Set the plot step and the frame to plot the detection position specified by the processing of the specific step on a two-dimensional plane. Presence of the object on the basis of a predetermined determination method using a plurality of plotted detection positions included in the frame for each rotation angle while rotating the frame at a predetermined rotation angle; And a direction determining step for determining at least one of the existing position and the traveling direction.

  In one aspect of the present invention, a transmission signal is transmitted by irradiating a radio wave in a predetermined direction, and a reflected radio wave is received out of the radio waves as the transmitted transmission signal. A reception signal is generated, and the generated reception signal is sampled for a predetermined time to detect the speed, distance, and angle of the object, and based on the detected distance and angle of the object, the object Relative detection positions are specified, the specified detection positions are plotted on a two-dimensional plane, a frame is set, and the frame is set at a predetermined rotation angle while rotating the frame at a predetermined rotation angle. Based on a predetermined determination method using a plurality of plotted detection positions included in the object, at least one of the existence position of the object and the traveling direction is He is constant.

  As described above, it is possible to accurately determine the occurrence of a collision in the pre-crash safety device, and it is possible to perform an appropriate collision preparatory operation against the collision, thereby improving safety at the time of the collision. It becomes.

  According to the present invention, it is possible to detect a position, a traveling direction, and a speed at which an approaching object exists, and when used in an automobile, it is possible to improve safety when an object collides.

  FIG. 1 is a diagram showing a configuration example of an embodiment of a radar apparatus according to the present invention.

  The radar device 1 is mounted on a vehicle, detects a vehicle that approaches a rear range of the vehicle (a range that is substantially right behind and includes a relatively far part) at a high speed that is higher than a predetermined speed, and detects a collision. It has a so-called pre-crash function that performs a preliminary operation in preparation for a collision.

  The radar apparatus 1 includes a transmission unit 11, a reception unit 12, a collision preliminary operation signal processing unit 13, and a collision preliminary operation control unit.

  The transmission unit 11 generates and radiates a radio wave composed of two frequencies CW (Continuous Wave) as a transmission signal. The reception unit 12 receives a radio wave reflected by an object among radio waves that are transmission signals transmitted from the transmission unit 11, generates a reception signal from the received radio wave, and performs a preliminary collision operation signal processing unit 13. To supply.

  The collision pre-operation signal processing unit 13 samples the reception signal supplied from the reception unit 12 with a relatively short period, detects the approach of another vehicle from the rear, determines the presence or absence of a collision, and determines the result. In response to this, the collision preliminary movement control unit 14 is caused to execute the collision preliminary movement. The collision preliminary operation control unit 14 controls the operation of a collision protection device that protects an occupant at the time of a collision, such as an audio warning device, a seat belt, an airbag, or a movable headrest, for example. When instructed to carry out more collision preparatory actions, a warning is given in advance by voice to call attention, and the seat belt is lifted to fix the occupant to the seat, preventing the occurrence of so-called whiplash. Or by operating the airbag at an appropriate timing before the collision to absorb the impact of the occupant at the time of the collision, or by operating the movable headrest and pressing it against the occupant's head, etc. A process of suppressing the impact caused by the reaction to the head at the time is executed.

  Next, a detailed configuration of the transmission unit 11 will be described.

  The transmission unit 11 includes an oscillation unit 31, a frequency switching unit 32, an amplification unit 33, a three-branch unit 34, an amplification unit 35, and an antenna 36.

  Based on the switching signal supplied from the frequency switching unit 32 at a predetermined interval, the oscillating unit 31 uses a CW signal having a frequency f1 of several tens of GHz band and a CW signal having a frequency f2 different from the frequency f1 by several MHz as a carrier wave. It is generated by switching, amplified by the amplifying unit 33 and supplied to the three branching unit 34. The frequency switching unit 32 supplies a switching signal that instructs the oscillation unit 31 to switch the frequency to be oscillated and also supplies the switching signal to the reception unit 12.

  The 3-branch unit 34 branches and supplies the CW signal having the frequency f1 or f2 supplied from the amplification unit 33 to each of the reception unit 12 and the amplification unit 35. The amplifying unit 35 outputs the CW signal having the frequency f1 or f2 supplied from the three-branch unit 34 as a radio wave from the antenna 36 as a transmission signal.

  The antenna 36 is provided in the vicinity of the rear center portion of the vehicle main body, and has an intensity distribution characteristic that can detect the range Z1 as shown in FIG. In FIG. 2, the downward direction in the figure is the traveling direction of the vehicle C1, and the antenna A (antennas 36, 51-1, and 51-2 in FIG. 1 are integrated together) provided near the rear center of the vehicle C1. The intensity distribution characteristics when radio waves are emitted from (composed) are shown.

  A range Z1 in the intensity distribution characteristic of FIG. 2 is a range of a hatched portion in the drawing including the angle α in the horizontal direction and a predetermined distance from the position where the antenna A exists with the rear front as the center. FIG. 2 shows a state in which the vehicle C1 is traveling in the downward direction in the figure in the lane L2 of the lanes L1 to L3.

  Next, the configuration of the receiving unit 12 will be described.

  The receiving unit 12 includes antennas 51-1 and 51-2, an adding unit 52, a subtracting unit 53, LNA (Low Noise Amplifier) 54-1 and 54-2, mixers 55-1 and 55-2, and a distributing unit 56. 57, LPF (Low Pass Filter) 58-1 to 58-3, amplifiers 59-1 to 59-3, ADC (Analog Digital Converter) 60-1 to 60-3, and reception level output unit 61. ing.

  The antennas 51-1 and 51-2 sequentially receive radio waves reflected on an object such as a vehicle or a human among radio waves as transmission signals emitted from the antenna 36 of the transmission unit 11. Are supplied to the adder 52 and the subtractor 53, respectively. The antenna 51-2 supplies a signal corresponding to the received radio wave to the reception level output unit 61. Since the reception level output unit 61 outputs the level of the received radio wave, the supplied received radio wave is not limited to the one from the antenna 51-2 but from the antenna 51-1. May be. Further, as described above, the transmission signal is transmitted with the frequencies f1 and f2 sequentially switched. However, when the object is moving, the Doppler frequencies fd1 and fd2 correspond to the frequencies f1 and f2 due to reflection. Will occur. For this reason, the radio waves received by the antennas 51-1 and 51-2 are those corresponding to the CW signal having the frequency f1 + fd1 and those corresponding to the CW signal having the frequency f2 + fd2 between f1 and f2 frequencies in the transmission signal. In synchronization with the timing, the signals are sequentially switched and received. Further, the radar device 1 including the configuration of the transmission unit 11 and the reception unit 12 is configured as an integrated package and is mounted on a substantially central portion of the rear portion of the vehicle, and the antenna 51-1 in view of the size of the vehicle. , 51-2 and the antenna 36 are arranged at substantially the same position. For this reason, the antennas 51-1 and 51-2 receive radio waves that are reflected by objects and returned to substantially the same position among radio waves as transmission signals output from the antenna 36.

  The adder 52 adds the signals supplied from the antennas 51-1 and 51-2, and adds the f1 sum signal (a frequency (f1 + fd1) including the Doppler frequency fd1 received by reflecting the CW signal having the frequency f1). And a sum signal of a frequency (f2 + fd2) including a Doppler frequency fd2 received by reflection of the CW signal of the frequency f2) is supplied to the LNA 54-1. The subtracting unit 53 subtracts the signals supplied from the antennas 51-1 and 51-2 and obtains the f1 difference signal (the frequency (f1 + fd1) including the Doppler frequency fd1 received by reflecting the CW signal having the frequency f1). ) And f2 difference signal (difference signal of frequency (f2 + fd2) including Doppler frequency fd2 received by reflection of CW signal of frequency f2) is supplied to LNA 54-1.

  The LNAs 54-1 and 54-2 receive the f1 sum signal or the f2 sum signal and the f1 difference signal or the f2 difference signal respectively supplied from the adder 52 and the subtractor 53, respectively, at the subsequent mixers 55-1, 55. -2 is amplified to the same level as the level of the CW signal having the frequency f1 or f2 supplied from the three-branch unit 34 and supplied to the mixers 55-1 and 55-2.

  The mixers 55-1 and 55-2 are the CW signal having the frequency f1 or f2 supplied from the three-branch unit 34 of the transmission unit 11, and the f1 sum signal supplied from each of the LNAs 54-1 and 54-2. And the f1 difference signal, or the f2 sum signal and the f2 difference signal are mixed and supplied to the distributing units 56 and 57, respectively. Signals in which the f1 sum signal and the f1 difference signal are mixed with the CW signal having the frequency f1 are referred to as the fd1 sum signal and the fd1 difference signal, respectively, and the f2 sum signal and the f2 difference signal are referred to as the CW signal having the frequency f2. The signals mixed with the signals are referred to as fd2 sum signal and fd2 difference signal, respectively.

  The distribution unit 56 distributes the signal supplied from the mixer 55-1 to the LPFs 58-1 and 58-2 as an fd1 sum signal and an fd2 sum signal for each frequency corresponding to the switching signal, and outputs them. To do. The allocating unit 57 distributes and outputs only the fd1 difference signal to the LPF 58-3 in accordance with the switching signal among the fd1 difference signal and the fd2 difference signal respectively supplied from the mixer 55-2.

  The LPFs 58-1 to 58-3 smooth the fd1 sum signal, the fd2 sum signal, and the fd1 difference signal respectively supplied from the allocating units 56 and 57, and then supply them to the amplifying units 59-1 to 59-3. To do. The amplifying units 59-1 to 59-3 amplify the fd1 sum signal, the fd2 sum signal, and the fd1 difference signal supplied from the LPFs 58-1 to 58-3, respectively, to the ADCs 60-1 to 60-3. Supply. The ADCs 60-1 to 60-3 convert the smoothed and further amplified fd1 sum signal, fd2 sum signal, and fd1 difference signal into digital signals and use them as received signals for collision preliminary operation signal control unit 13. To supply.

  The reception level output unit 61 measures the reception level of the signal received by the antenna 51-2, converts it to a digitized signal, and supplies the signal to the collision preliminary operation signal processing unit 13.

  Next, the configuration of the collision preliminary motion signal processing unit 13 will be described.

  The collision pre-operation signal processing unit 13 includes FFT (Fast Fourier transform) 71-1 to 71-3, a collision determination FFT timing control unit 72, a Doppler frequency calculation unit 73, a distance calculation unit 74, an angle A calculation unit 75 and a collision determination unit 76 are included.

  The FFTs 71-1 to 71-3 are, based on the control signal from the collision determination FFT timing control unit 72, the fd1 sum signal, the fd2 sum signal, and the fd1 difference signal respectively supplied as reception signals from the reception unit 12. Are sequentially sampled and FFT processed, and the FFT 71-1 supplies the result obtained from the spectrum distribution of the fd1 sum signal to the distance calculation unit 74 and the angle calculation unit 75, and the FFT 71-2 provides the spectrum result of the fd2 sum signal. Are supplied to the Doppler frequency calculation unit 73 and the distance calculation unit 74, and the FFT 71-3 supplies the result obtained from the spectrum distribution of the fd1 difference signal to the angle calculation unit 75.

  The collision determination FFT timing control unit 72 adds the built-in counter 72a every predetermined time, and instructs the FFTs 71-1 to 71-3 to execute the FFT processing when the predetermined time T1 has elapsed.

  The Doppler frequency calculation unit 73 calculates the Doppler frequency fd2 based on the spectrum result of the fd2 sum signal supplied from the FFT 71-2, and calculates the velocity v1 at the detection position of the detected object from the obtained Doppler frequency fd2. And supplied to the distance calculation unit 74, the angle calculation unit 75, and the collision determination unit 76.

  The distance calculation unit 74 is based on the fd1 sum signal and the fd2 sum signal supplied from the FFTs 71-1 and 71-2, and the speed v1 supplied from the Doppler frequency calculation unit 73, and the fd1 sum signal and the fd2 sum signal. The distance D1 to the position where the object is detected is calculated from the phase difference information and supplied to the collision determination unit 76.

  The angle calculation unit 75 detects the angle of the position where the object is detected from the intensity ratio between the fd1 sum signal and the fd1 difference signal based on the fd1 sum signal from the FFT 71-1, the fd1 difference signal from the FFT 71-3, and the velocity v1. θ1 is calculated and supplied to the collision determination unit 76.

  The collision determination unit 76 includes a detection position specifying unit 81, a detection position storage unit 82, a frame matching determination unit 83, a frame setting unit 84, a frame rotation unit 85, a content number counting unit 86, a direction determining unit 87, a vector setting unit 88, A vector storage unit 89, a vector correction unit 90, a vehicle case estimation unit 91, and a speed range determination unit 92 are provided. The detected object speed v 1 supplied from the Doppler frequency calculation unit 73 and supplied from the distance calculation unit 74. When determining the presence or absence of a collision based on the distance D1 and the angle θ1 of the angle calculation unit 75 and determining that there is a possibility of a collision, the collision preliminary operation control unit 14 is caused to execute the preliminary collision operation. .

  The detection position specifying unit 81 specifies the detection position of the detection object based on the speed v1, the distance D1, and the angle θ1 at the detection position of the detection object, and stores the detection position in the detection position storage unit 82 in association with the detection time. Note that the detection position here does not necessarily match the center position of the vehicle that is the detection object, and the radio wave transmitted by the transmission unit 11 is reflected, for example, somewhere in the front portion of the vehicle. It is the position.

  The frame matching determination unit 83 determines whether or not frame matching described later is possible based on the number of past detection position information stored in the detection position storage unit 82. That is, if the number of detection positions is not equal to or greater than the predetermined number, frame matching is impossible. Therefore, it is determined whether or not the information on the detection positions is accumulated as many as frame matching is possible.

  The frame setting unit 84 sets the size of the matching frame required for frame matching based on the speed v1. That is, the matching frame to be set in the frame matching is a substantially rectangular shape having a width corresponding to the width of the vehicle as the test object and a length corresponding to the speed of the vehicle. Therefore, the frame setting unit 84 sets the average vehicle width (for example, about 1.7 m) of a general ordinary vehicle as the width of the matching frame, and further, sets the distance obtained by multiplying the speed v1 by a predetermined time as the matching frame. Set as length.

  The frame rotation unit 85 rotates the matching frame set by the frame setting unit 84 by a predetermined angle with reference to the current detection position. The content number counting unit 86 counts the number of detection positions included in the matching frame rotated by the frame rotation unit 85 for each predetermined rotation angle as a content number, and stores it for each rotation angle.

  The direction determination unit 87 determines the direction by assuming that the rotation angle that is the maximum value among the content numbers for each rotation angle stored in the content number counting unit 86 is the traveling direction of the vehicle. Moreover, the direction determination part 87 determines the presence position of a vehicle based on the information of the position of the matching frame where the number of inclusions becomes the maximum.

  The vector determination unit 88 determines the detected vehicle speed vector based on the vehicle location and travel direction information determined by the direction determination unit 87, and associates the detected vehicle speed vector with the detected time. Remember me.

  The vector correction unit 90 corrects the current speed vector using the past speed vector stored in the vector storage unit 89.

  The vehicle estimator 91 estimates the width of the vehicle from the variation in the detection position and the variation due to noise. The variation in the detection position includes a variation component caused by a difference in vehicle width and a variation component caused by noise. Therefore, the vehicle case estimation unit 91 obtains the width of the vehicle by removing the variation component caused by noise from the variation in the detection position. The magnitude of variation due to noise has a correlation with the magnitude of the reception level. Corresponding to each reception level supplied from the reception level output unit 61, noise variation defined by detection performance is determined in advance. The vehicle type estimation unit 91 obtains the variation caused by the width of the vehicle by removing the variation due to the noise corresponding to the reception level from the variation of the detection position, and is a large vehicle larger than the vehicle rating, that is, the normal vehicle. Or an ordinary vehicle (including a smaller vehicle).

  The speed range determination unit 92 includes a vehicle case determination unit 92a, and determines the vehicle case estimated by the vehicle case estimation unit 91 and warns of a collision according to the determined vehicle case and the speed. Determine the warning range. The collision determination unit 76 determines the possibility of a collision depending on whether or not the vehicle presence position is included in the warning range.

  When the collision determination unit 76 determines that there is a possibility of a collision, the collision preliminary operation instruction unit 93 causes the collision preliminary operation control unit 14 to perform a preliminary collision operation according to the vehicle case.

  Next, a configuration example of the collision preliminary operation control unit 14 will be described.

  The collision preliminary motion control unit 14 includes a large vehicle preliminary motion control unit 14a and a normal vehicle preliminary motion control unit 14b. When the collision determination operation is instructed by the large vehicle from the collision determination unit 76, the large vehicle preliminary motion control unit 14b is operated. The controller 14a is controlled to control the collision protection device to perform a collision preparatory operation in preparation for a large vehicle collision. Further, the collision preliminary operation control unit 14 controls the normal vehicle preliminary operation control unit 14b when the collision determination unit 76 instructs the normal vehicle collision preliminary operation to prepare for the collision of the normal vehicle. To cause the collision protection device to execute.

  Next, object measurement processing by the radar apparatus 1 of FIG. 1 will be described with reference to the flowchart of FIG.

  In step S1, the oscillating unit 31 oscillates either the C1 signal of the f1 frequency or the CW signal of the f2 frequency based on the switching signal from the frequency switching unit 32, and amplifies it by the amplifying unit 33 to branch into three. Output to the unit 34. At this time, the frequency switching unit 32 also supplies the same switching signal to the receiving unit 12.

  In step S <b> 2, the three branching unit 34 branches the CW signal of the f1 frequency or the CW signal of the f2 frequency supplied from the amplifying unit 33 to the receiving unit 12 and the amplifying unit 35. Supply each. The amplifying unit 35 transmits the CW signal of the f1 frequency or the CW signal of the f2 frequency supplied from the three branch unit 34 as a transmission signal by outputting a radio wave from the antenna 36. To do. At this time, the radio wave as a transmission signal transmitted from the antenna 36 is output with an intensity distribution as shown in FIG. 2, for example. Note that the shape formed by the range Z1 in FIG. 2 does not have to be strict, and may be transmitted so as to obtain an intensity distribution that has a substantially similar shape.

  Since the transmission signal as the radio wave output by the process of step S2 is output by the intensity distribution shown in FIG. 2, when an object (vehicle) exists in the range constituted by the range Z1, it is reflected by the object. The That is, as described above, as shown in the upper part of FIG. 4, the transmission signal is simplified and expressed as antenna A (in FIG. 4, antennas 36, 51-1 and 51-2 are integrated. ), The CW signals having the frequencies f1 and f2 are sequentially switched and output. For this reason, when reflected by the vehicle C1, which is an object, Doppler frequencies fd1 or fd2 are generated corresponding to the CW signals of the respective frequencies, so that as shown in the lower part of FIG. , F2 + fd2 is reflected as a CW signal, and a radio wave that is a reflected wave is received.

  Therefore, in step S3, the antennas 51-1 and 51-2 receive the reflected radio waves, and supply signals corresponding to the received radio waves to the addition unit 52 and the subtraction unit 53, respectively. At this time, the antenna 51-2 also supplies a signal corresponding to the received radio wave to the reception level output unit 61.

  In step S4, the adding unit 52 adds the reception signals supplied from the antennas 51-1 and 51-2 to each other to generate an f1 sum signal or an f2 sum signal, and outputs the sum signal to the LNA 54-1. The voltage is amplified and output to the mixer 55-1.

  In step S5, the subtraction unit 53 subtracts the reception signals supplied from the antennas 51-1 and 51-2 from each other to generate an f1 difference signal or an f2 difference signal, and outputs the difference signal to the LNA 54-2. And output to the mixer 55-2.

  In step S6, the mixer 55-1 mixes the transmission signal supplied from the three-branch unit 34 of the transmission unit 11 and the sum signal, and outputs the sum signal to the distribution unit 56 as a mixed signal of the sum signal. Further, the mixer 55-2 mixes the transmission signal supplied from the three-branch unit 34 of the transmission unit 11 and the difference signal, and outputs the mixed signal to the distribution unit 57 as a mixed signal of the difference signal.

  The processes in steps S2 to S6 are processed at different timings as shown in the flowchart, but the actual processes are processed almost simultaneously and are substantially processed in parallel. is there.

  In step S7, the allocating unit 56, when the switching signal supplied from the frequency switching unit 32 of the transmission unit 11 in the process of step S10 is a switching signal corresponding to the frequency f1, is the corresponding sum signal fd1 sum. When the signal is supplied to the LPF 58-1, and the switching signal is the switching signal corresponding to the frequency f2, the corresponding sum signal fd2 sum signal is supplied to the LPF 58-2. Further, the allocating unit 57 fd1 difference signal which is a corresponding difference signal only when the switching signal supplied from the frequency switching unit 32 of the transmission unit 11 in the process of step S10 is a switching signal corresponding to the frequency f1. Is supplied to LPF58-3.

  That is, as shown in the upper left part of FIG. 5, when the frequency switching unit 32 outputs Hi as the switching signal at the frequency f1 and Low at the frequency f2, as shown in the middle left part of FIG. In response to the switching signal, the distribution unit 56 alternately receives the fd1 sum signal corresponding to the frequency f1 and the fd2 sum signal corresponding to the frequency f2 from the mixer 55-1. Sequentially supplied. At this time, when the switching signal is Hi corresponding to the frequency f1, the allocating unit 56 supplies the fd1 sum signal to the LPF 58-1 and the switching signal corresponds to the frequency f2, as shown in the upper right part of FIG. When Low, the fd2 sum signal is supplied to the LPF 58-2 as shown in the middle right part of FIG.

  Further, as shown in the upper left part of FIG. 5, when the frequency switching unit 32 outputs Hi as the switching signal at the frequency f1 and Low at the frequency f2, as shown in the lower left part of FIG. The distribution unit 57 alternately receives the fd1 difference signal, which is the difference signal corresponding to the frequency f1, and the fd2 difference signal, which is the difference signal corresponding to the frequency f2, from the mixer 55-2. Sequentially supplied. At this time, the allocating unit 57 supplies the fd1 difference signal to the LPF 58-3 as shown in the lower right part of FIG. 5 only when the switching signal is Hi corresponding to the frequency f1.

  In step S8, the LPFs 58-1 to 58-3 smooth the fd1 sum signal, the fd2 sum signal, and the fd1 difference signal sequentially supplied from the allocating units 56 and 57, respectively, and amplify units 59-1 to 59, respectively. -3. The amplifying units 59-1 to 59-3 amplify the supplied fd1 sum signal, fd2 sum signal, and fd1 difference signal, respectively, and supply the amplified signals to the ADCs 60-1 to 60-3. The ADCs 60-1 to 60-3 convert the smoothed and further amplified fd1 sum signal, fd2 sum signal, and fd1 difference signal into digital signals and supply them to the collision pre-operation signal processing unit 13 as received signals. . At this time, the reception level output unit 61 converts the level of the signal corresponding to the received radio wave supplied from the antenna 51-2 into a predetermined digital signal and outputs it to the collision preliminary operation signal processing unit 13.

  In step S9, the frequency switching unit 32 determines whether or not a predetermined time has elapsed since switching to the currently output frequency f1 or f2 CW signal, and the predetermined time has not elapsed. If it is determined, the process returns to step S2. On the other hand, when it is determined in step S9 that the predetermined time has elapsed, in step S10, the frequency switching unit 32 switches the switching signal, that is, a frequency different from the frequency output so far. And the oscillation unit 31 oscillates the CW signal.

  The above processing is summarized as follows. In the process of step S2, for example, if the radio wave output from the antenna 36 of the transmission unit 11 is expressed by the following formula (1), the radio waves received by the antennas 51-1 and 51-2 are: It represents as the following formula | equation (2) and Formula (3).

  Here, Ti is the transmission radio wave, Rx1Rx2 is the reception radio wave of the antennas 51-1, 51-2, A and B are the intensity of the transmission radio wave and the reception radio wave, respectively, d is the distance to the object, v Is the relative speed between the vehicle on which the radar device 1 is mounted and the vehicle C1 as an object that reflects radio waves as transmission signals, and fi is the frequency of the transmitted radio waves (frequency f1 when i = 1, when i = 2) Frequency f2), c is the speed of light, L is, for example, the distance between the antennas 51-1 and 51-2 shown in FIG. 6, and θ is between the antennas 51-1 and 51-2 shown in FIG. The angle (angle of arrival) of the object C1 from the center is shown respectively. In addition, Lsin (θ) in the third term in parentheses in the equation (3) indicates a path difference between radio waves reaching both the antennas 51-1 and 51-2 as shown in FIG. 6. . Therefore, if the paths of the radio waves received from the vehicle C1 to the antennas 51-1 and 51-2 are parallel, the received signals received by both the antennas 51-1 and 51-2 include the path A phase difference corresponding to the difference Lsin (θ) is generated.

  Therefore, in the process of step S4, the adding unit 52 adds the radio wave signals received by the antennas 51-1 and 51-2 represented by the equations (2) and (3), thereby obtaining the following equation. A sum signal Radd shown in (4) is generated. In Expression (4), information on the phase difference caused by the path difference Lsin (θ) is expressed as an amplitude. That is, in the expression (4), the information of the phase difference caused by the path difference Lsin (θ) is expressed as an amplitude by the term 2Bcos (π · Lsin (θ) · fi / c).

  In the process of step S5, the subtraction unit 53 subtracts the signals corresponding to the received radio waves of the antennas 51-1 and 51-2 represented by the expressions (2) and (3), thereby A difference signal Rsub indicated by (5) is generated. In Expression (5), information on the phase difference caused by the path difference Lsin (θ) is expressed as an amplitude. That is, in the expression (5), the information of the phase difference caused by the path difference Lsin (θ) is expressed as the amplitude by the term 2Bsin (π · Lsin (θ) · fi / c).

  Then, by the processing of step S6, the mixers 55-1 and 55-2 mix the sum signal Radd and the difference signal Rsub represented by the equations (4) and (5) with the transmission signals, respectively. A sum signal mixed signal Radd_d and a difference signal mixed signal Rsub_d represented by the following equations (6) and (7) are obtained.

  The mixed signal Radd_d of this sum signal is the fd1 sum signal or the fd2 sum signal corresponding to the frequency f1 or f2 in FIG. 5, and the mixed signal Rsub_d of the difference signal is the fd1 difference signal corresponding to the frequency f1 in FIG. .

  That is, by the above processing, the fd1 sum signal, the fd2 sum signal, and the fd1 difference signal represented by the equations (6) and (7) are synchronized with the switching signal of the frequency f1 or f2, and are shown in FIG. Are supplied to LPFs 58-1 to 58-3, respectively. Then, by the process of step S9, the LPFs 58-1 to 58-3 smooth the fd1 sum signal, the fd2 sum signal, and the fd1 difference signal supplied discretely to obtain continuous values. Converted and supplied to the amplifying units 59-1 to 59-3. The amplifying units 59-1 to 59-3 amplify each and supply the amplified signals to the ADCs 60-1 to 60-3. Further, the ADCs 60-1 to 60-3 convert the signals into digital signals, and the collision preliminary operation signal processing unit 13 receives three types of received signals (the fd1 sum signal and the fd2 sum signal converted into digital signals after being smoothed). , As well as the fd1 difference signal).

  Next, the collision preliminary operation signal processing will be described with reference to the flowchart of FIG.

  In step S21, the collision determination FFT timing control unit 72 initializes the count value X of the collision determination FFT timing measurement counter 72a and starts counting.

  In step S22, the FFTs 71-1 to 71-3 acquire the fd1 sum signal and the fd2 sum signal, and the fd1 difference signal, which are digital signals supplied from the receiving unit 12, and sequentially store and sample them.

  In step S23, the collision determination FFT timing control unit 72 determines whether or not the count value X of the counter 72a exceeds a predetermined time T1, that is, whether or not a predetermined sampling time is exceeded. Note that this time T1 needs to be set to a relatively short time since it is necessary to determine a collision, and when a collision is determined, it is necessary to perform a preliminary operation for dealing with the collision.

  If it is determined in step S23 that the count value X is not greater than the predetermined time T1, the process returns to step S22. That is, the processing in steps S22 and S23 is repeated until the predetermined time T1 elapses, and sampling is continued.

  In step S23, for example, when it is determined that the count value X is larger than the predetermined time T1 and it is determined that the timing for ending sampling and starting the process has been reached, in step S24, the collision determination FFT timing control is performed. The unit 72 causes the FFTs 71-1 to 71-3 to execute FFT processing. In response to this instruction, the FFTs 71-1 to 71-3 perform FFT processing based on the sampled data, and the FFT 71-1 sends the result obtained from the spectrum distribution of the fd1 sum signal to the distance calculation unit 74. Supply. Further, the FFT 71-2 supplies the result obtained from the spectrum distribution of the fd2 sum signal to the Doppler frequency calculation unit 73 and the distance calculation unit 74. Further, the FFT 71-3 supplies a result obtained from the spectrum distribution of the fd1 difference signal to the angle calculation unit 75.

  In step S25, the Doppler frequency calculation unit 73 obtains the Doppler frequency fd2 based on the spectrum of the fd2 sum signal, further calculates the velocity v1 at the detection position of the object from the Doppler frequency fd2, and calculates the distance calculation unit 74, the angle It outputs to the calculation part 75 and the collision determination part 76. That is, the relationship between the Doppler frequency fd2 and the object velocity v is expressed by the following equation (8). Here, v is the speed, fi (i = 1 or 2) is the frequency of the CW signal, and c is the speed of light. Therefore, the Doppler frequency calculation unit 73 calculates the velocity v as the velocity v1 at the detection position of the object by modifying Equation (8) based on the Doppler frequency fd2 obtained from the spectrum distribution of the fd2 sum signal.

  In step S26, the distance calculation unit 74 obtains the result obtained from the spectrum distribution of the fd1 sum signal supplied from the FFT 71-1, and the result obtained from the spectrum distribution of the fd2 sum signal supplied from the FFT 71-2. In addition, based on the velocity v1, the distance D1 from the phase difference between the fd1 sum signal and the fd2 sum signal to the detection position of the object is calculated and supplied to the collision determination unit 76.

  That is, while the frequency f1 is several tens of GHz, the frequency f2 is only a frequency difference between the frequency f1 and several MHz, so the Doppler frequencies fd1 and fd2 are represented by 2vf1 / c and 2vf2 / c, respectively. However, both can be considered to be the same.

  The phase difference Δφ between the mixed signal Radd_d of the sum signal expressed by the above-described Expressions (6) and (7) and the mixed signal Rsub_d of the difference signal is expressed by the following Expression (9). Here, if the frequency difference between the frequencies f1 and f2 is Δf, the distance d to the detection position of the object is expressed by the following equation (10).

  Therefore, in step S26, the distance calculation unit 74 calculates the distance d to the detection position of the object as the distance D1, using the above-described equation (10).

  In step S27, the angle calculator 75 calculates the fd1 sum based on the result obtained from the spectrum distribution of the fd1 sum signal supplied from the FFT 71-1, the result obtained from the spectrum distribution of the fd1 difference signal, and the velocity v1. The angle θ1 of the detection position of the object (corresponding to the arrival angle θ in FIG. 6) is calculated from the ratio between the result obtained from the spectrum distribution of the signal and the result obtained from the spectrum distribution of the fd1 difference signal. That is, the amplitudes Aadd and Asub in the mixed signal Radd_d of the sum signal and the mixed signal Rsub_d of the difference signal expressed by the above-described expressions (6) and (7) are respectively expressed by the following expressions (11) and (12). ).

  Here, the angle of arrival θ in FIG. 6 is expressed by the following equation (13).

  The angle calculator 75 calculates the angle θ as the angle θ1 using the above-described equation (13), and supplies the calculated angle θ1 to the collision determination unit 76.

  With the above processing, the velocity v1, the distance D1, and the angle θ1 of the detected object at the detection position are supplied to the collision determination unit 76 at this time.

  Therefore, in step S28, the collision determination unit 76 controls the detection position specifying unit 81 to specify the detected position Pt of the detected vehicle based on the speed v1, the distance D1, and the angle θ1, and in step S29. The detected position storage unit 82 stores the information in association with the time information t. That is, for example, as shown in FIG. 8, the vehicle C1 on which the radar device 1 is mounted is traveling in the downward direction in the figure, and the vehicle C2 is approaching while traveling in the same direction from behind. In this case, for example, the detection positions Pt are sequentially detected as the detection positions Pt1 to Pt11 and sequentially stored in the detection position storage unit 82. In FIG. 8, the vertical axis is an axis indicating the distance in the traveling direction of the vehicle C1 from the vehicle C1 to the detection position, and the horizontal axis is an axis indicating the detection position in the horizontal direction. Each plotted example is shown. That is, the detection positions Pt1 to Pt11 are arranged and plotted in time series from the top in the figure, and the detection positions in the horizontal direction for each time are shown.

  In addition, the detection position varies depending on the positional relationship between the radar apparatus and the vehicle and the radio wave interference state determined by the vehicle outer shape. For this reason, for example, as shown in FIG. 9, the variation does not follow the normal distribution, but becomes a random variation as shown in FIG. 8. For example, in order to estimate the center route of the detected vehicle In addition, even if the obtained information on the detected position is processed by a low-pass filter or a Kalman filter, it cannot be estimated with high accuracy. In FIG. 9, detection is performed when the vehicle C1 having the radar device 1 mounted in the downward direction in the drawing is traveling downward and the vehicle C2 is approaching while traveling in the same direction from behind. An example when the positions are distributed according to a normal distribution as shown in the lower part of the figure is shown. However, in reality, as described above, the plot result of the detection position does not vary according to the normal distribution as shown in FIG.

  In step S <b> 30, the collision determination unit 76 controls the frame matching determination unit 83 to perform frame matching according to the number of detection positions Pt stored in the detection position storage unit 82. Determine whether. That is, in frame matching, which will be described later, accurate determination is difficult unless the information on the detection position Pt is a predetermined number or more. Specifically, the frame matching determination unit 83 is stored in the detection position storage unit 82. It is determined whether or not the number of detected positions Pt is larger than a predetermined number that allows frame matching and that frame matching is sufficiently possible.

  If it is determined in step S30 that the detection position information stored in the detection position storage unit 82 is more than a predetermined number and frame matching is possible, the collision determination unit 76 in step S31 Then, the frame setting unit 84 is controlled to set a matching frame corresponding to the speed v1.

  That is, as shown in FIG. 8, the detection position is on a two-dimensional space composed of an axis indicating the detection position in the horizontal direction and an axis indicating the distance in the traveling direction of the vehicle C1 from the vehicle C1 to the detection position. Expressed as a distribution of Hereinafter, a space indicating the distribution of detection positions is referred to as a detection position distribution space. As described above, the variation of the detection position in the detection position distribution space does not follow the normal distribution, but at least the detection position indicates that a part of the vehicle exists. Therefore, in this distribution of detection positions, assuming that a region where the head portion of the vehicle passes for a predetermined time is assumed as a matching frame, the distribution of detection positions should be entirely included in the matching frame if there is no variation due to noise. . Based on these assumptions, frame matching is based on the assumption that the region where the vehicle passes at a predetermined time is set as a matching frame, and the direction of the set matching frame is changed (the position is also changed if necessary). ), The traveling path of the center position of the vehicle is estimated by determining the position and direction including the most information of the detected position.

  Therefore, the frame setting unit 84 sets the average vehicle width of the ordinary vehicle to the width of the matching frame, and sets the length of the matching frame according to the speed v1. That is, when the speed v1 is low, for example, the distribution of the detection positions in the detection position distribution space is the detection positions Pt1 to Pt10 shown on the left side of FIG. On the other hand, when the speed v1 is high, the distribution of the detection positions in the detection position distribution space becomes sparse because the intervals between the detection positions are widened as shown in the right part of FIG. Therefore, if the speed v1 is low, the frame setting unit 84 sets a matching frame as shown by the matching frame F1 or F2 as shown in the left part of FIG. 10, and if the speed v1 is high, The length is increased and set to a size such as the matching frame F11 or F12 as shown in the right part of FIG. That is, the frame setting unit 84 sets the length of the matching frame in proportion to the speed v1.

  In step S32, the collision determination unit 76 controls the frame rotation unit 85 to set a counter i for counting the rotation angle φi of the matching frame set by the frame setting unit 84 to 0, and the rotation angle φi of the matching frame. Is initialized. That is, for example, the frame rotation unit 85 initializes the matching frame in the detection position distribution space as indicated by the left matching frame F1 in FIG. 10 or the right matching frame F11 in FIG. Set the initial angle to rotate the frame).

  In step S33, the collision determination unit 76 controls the content number counting unit 86 to count the number of detection positions plotted in the region set as the matching frame in the detection position distribution space as the content number Ci. Let me remember.

  In step S34, the collision determination unit 76 controls the frame rotation unit 85 to determine whether or not the number of detection positions has been counted for all rotation angles φi. If it is determined in step S34 that the number of detection positions is not counted at all the rotation angles φi, the collision determination unit 76 controls the frame rotation unit 85 and increments the counter i by 1 in step S35. Thus, the corresponding rotation angle φi is set by rotating it by a predetermined angle, and the process returns to step S33. That is, the collision determination unit 76 controls the frame rotation unit 85 to rotate the matching frame F1 by a predetermined angle in the arrow direction as shown in the left part of FIG. 10, or the right part of FIG. As shown, the matching frame F11 is rotated by a predetermined angle in the direction of the arrow.

  That is, while rotating by a predetermined rotation angle, the process of counting the content number Ci indicating the number of detection positions plotted in the matching frame in the detection position distribution space for each rotation angle is repeated, and for all rotation angles, Until the content number Ci is counted, the processes of steps S33 to S35 are repeated.

  In step S35, for example, the matching frame F1 shown in the left part of FIG. 10 is rotated by a predetermined rotation angle and rotated to the matching frame F2, or the matching frame F11 shown in the right part of FIG. Is rotated by a predetermined rotation angle and rotated to the matching frame F12, etc., and it is determined that the content number Ci indicating the number of detection positions plotted for each rotation angle is counted for all rotation angles. In step S36, the collision determination unit 76 controls the direction determination unit 87 to determine the rotation angle φi at which the content number Ci is the maximum as the traveling direction of the approaching vehicle.

  In step S <b> 37, the collision determination unit 76 controls the vector setting unit 88 to set a vehicle speed vector, and stores it in the vector storage unit 89 in association with the detection time. That is, by assuming that the center of gravity position of the matching frame is a traveling path in the center of gravity position of the vehicle, for example, the vector setting unit 88 starts from the center of gravity position of the matching frame where the number of inclusions Ci is maximum, and corresponds to the speed v1. A vector of magnitude and direction is set as a vehicle speed vector and stored in the vector storage unit 89.

  In step S <b> 38, the collision determination unit 76 controls the vector correction unit 90 to correct the current speed vector using the speed vector at the past time stored in the vector storage unit 89. That is, for example, as shown in FIG. 11, when the velocity vectors Vc1 to Vc5 are stored in the vector storage unit 89 and the velocity vector Vc6 is detected at the current timing, the vector correction unit 90 Since the position of the starting point is shifted, for example, the position of the starting point is corrected to the position of the end point of the latest velocity vector Vc5, and the velocity vector Vc6 ′ is stored in the vector storage unit 89 as the corrected velocity vector Vc6.

  In step S39, the collision determination unit 76 controls the vehicle estimator 91 to respond to the reception level of the reception unit 12 based on the variation in the information on the detected position existing in the matching frame corresponding to the corrected speed vector. The size of the detected vehicle is estimated in consideration of noise variation measured in advance, and the vehicle size is estimated from the estimated size of the vehicle. That is, the variation in the information of the actually detected detection position includes the variation due to the noise that can be recognized in advance according to the reception level, in addition to the variation in the reflected radio wave. Therefore, the vehicle size estimation unit 91 estimates the vehicle width of the detected vehicle in consideration of the variation width caused by the noise corresponding to the reception level to the width obtained by the detection position plotted in the matching frame, and estimates The vehicle case is estimated according to the vehicle width.

  More specifically, the vehicle level estimation unit 91 receives the reception level supplied from the reception level output unit 61 with respect to the width between the detection positions plotted on the leftmost side and the right side in the matching frame, for example. Assuming that the result of adding the variation width due to noise estimated to occur in advance is the vehicle width of the detected vehicle, the vehicle case of the vehicle detected corresponding to the vehicle width is normal It is estimated whether it is a vehicle or a large vehicle larger than a normal vehicle.

  In step S40, the collision determination unit 76 controls the speed range determination unit 92 to determine whether or not the vehicle case estimated by the vehicle case estimation unit 91 is a large vehicle. At this time, the speed range determination unit 92 controls the vehicle case determination unit 92a and determines whether the vehicle case is a large vehicle based on the estimation result from the vehicle case estimation unit 91. In step S40, for example, when it is determined that the estimated vehicle size is a large vehicle, the process proceeds to step S41.

  In step S41, the speed range determination unit 92 sets the collision range A2 (FIG. 2) as a range in consideration of the possibility of collision of a large vehicle. Then, the collision determination unit 76 determines whether or not the detected speed v1 of the large vehicle is greater than a predetermined predetermined speed V2 (<V1) and is within the collision range A2. In step S41, if the detected speed v1 of the large vehicle is greater than the predetermined predetermined speed V2 (<V1) and is within the collision range A2, it is considered that there is a possibility of a collision by the large vehicle in step S42. The collision determination unit 76 controls the collision preliminary operation instruction unit 93 to instruct the collision preliminary operation control unit 14 to perform the preliminary collision operation corresponding to the large vehicle.

  In response to this, in step S43, the collision preliminary motion control unit 14 controls the large vehicle preliminary motion control unit 14a to warn of the occurrence of the collision by, for example, issuing a warning sound in preparation for the collision of the large vehicle. At the same time, the seat belt is pulled up with a stronger restraining force than when a normal vehicle collides, and the occupant is fixed to the seat to prevent the occurrence of so-called whiplash and the air at the appropriate timing before the collision for large vehicles. Operate the bag to absorb the impact at the time of collision, and press the movable headrest against the head more strongly than in a normal vehicle, etc. Preliminary collision operation corresponding to large vehicle collisions is performed.

  On the other hand, in step S40, for example, when it is determined that the estimated vehicle size is not a large vehicle but a normal vehicle, the process proceeds to step S44.

  In step S44, the speed range determination unit 92 sets the collision range A1 (FIG. 2) as a range in consideration of the possibility of a collision of a normal vehicle. Then, the collision determination unit 76 determines whether or not the detected speed v1 of the large vehicle is greater than a predetermined predetermined speed V1 (> V2) and is within the collision range A1. In step S44, if the detected speed v1 of the large vehicle is greater than the predetermined predetermined speed V1 and is within the collision range A1, it is determined in step S45 that there is a possibility of a collision by the ordinary vehicle, and the collision determination unit 76 controls the collision preliminary movement instruction unit 93 to instruct the collision preliminary movement control unit 14 to perform the collision preliminary movement corresponding to the ordinary vehicle.

  In response to this, in step S46, the collision preliminary motion control unit 14 controls the normal vehicle preliminary motion control unit 14b to warn of the occurrence of the collision by, for example, issuing a warning sound in preparation for a collision of the normal vehicle. At the same time, the seat belt is pulled up with an appropriate restraining force at the time of a collision of a normal vehicle to fix the occupant to the seat, so that the occurrence of so-called whiplash is suppressed, or the air at an appropriate timing before the collision for a normal vehicle Operate the bag to absorb the impact at the time of the collision, and further press the movable headrest against the head appropriately for ordinary vehicles, etc. to suppress the impact caused by the recoil to the head at the time of the passenger's collision Preliminary collision operation corresponding to the collision of ordinary vehicles is performed.

  That is, when the detected vehicle is a normal vehicle, for example, as shown in FIG. 2, a collision range A1 indicated by a dotted line relatively close to the vehicle C1, which is the host vehicle, is a range that considers the possibility of a collision. If a collision of a large vehicle is detected, the collision range A2 indicated by the alternate long and short dash line including the range far from the vehicle C1, which is the host vehicle, is set as a range that considers the possibility of a collision. Therefore, for large vehicles that are heavily damaged at the time of collision, the possibility of a collision is determined from a distance, and the preliminary action corresponding to the collision is executed at an earlier timing, thereby improving the safety at the time of the collision. It becomes possible to make it.

  In determining the possibility of a collision at the speed v1, in the case of a large vehicle, the speed v1 for determining the possibility of a collision is a predetermined speed V2 that is lower than the predetermined speed V1 for determining the possibility of a collision with a normal vehicle. By setting to, it is possible to improve the safety at the time of a collision by more surely performing a preliminary operation for a collision of a large vehicle that is expected to be damaged by a collision at a low speed.

  In step S44, when the detected speed v1 of the large vehicle is not greater than the predetermined predetermined speed V1 or not within the collision range A1, the detected speed v1 of the large vehicle is determined to be the predetermined predetermined speed in step S41. If it is not greater than the velocity V2 (<V1) or not within the collision range A2, or if it is determined in step S30 that frame matching is not possible, the process returns to step S21, and thereafter The process is repeated.

  In the above description, an example using the Doppler frequency fd2 has been described in calculating the velocity of the detected object. However, since the frequency difference between the frequencies f1 and f2 is several MHz, the Doppler frequency fd1 is used. In this way, substantially the same speed can be obtained. Similarly, in the above description, the example of using the phase difference between the fd1 sum signal and the fd2 sum signal has been described in calculating the distance. However, the phase difference between the fd1 difference signal and the fd2 difference signal may be used. For example, it is configured so that both can be measured, and after comparing the signal quality of the fd1 sum signal and the fd2 sum signal with the signal quality of the fd1 difference signal and the fd2 difference signal, the distance is calculated using the signal quality that is high. And the accuracy may be improved. Similarly, in the above description, the example of obtaining the angle by the ratio of the fd1 sum signal and the fd1 difference signal has been described. However, the angle may be obtained by the ratio of the fd2 sum signal and the fd2 difference signal. Furthermore, the signal quality of the fd1 sum signal and the fd1 difference signal is compared with the signal quality of the fd2 sum signal and the fd2 difference signal, and the angle is calculated using a signal having a high signal quality, thereby improving the accuracy. You may do it.

  As described above, according to the present invention, when detecting the position of an approaching object, a frame using the detection result plot result even when using information on a detection position that is a distribution that cannot be processed such as a normal distribution. By matching, it is possible to specify the position, traveling direction, and speed of an object that is approaching accurately, so that it is possible to accurately specify the position where the object exists.

  In addition, since it is possible to accurately specify the position of the approaching object, the traveling direction, and the speed, for example, in the pre-crash safety device, the preliminary collision operation can be performed at an accurate timing. .

  Furthermore, the size of the approaching vehicle (object) can be estimated in consideration of the variation width due to noise corresponding to the reception level that can be recognized in advance, with the result that the pre-crash is detected as a result. In a safety device or the like, it is possible to perform a preliminary collision operation corresponding to the vehicle grade of an approaching vehicle, and it is possible to further improve safety at the time of collision.

  Incidentally, the series of monitoring processes described above can be executed by hardware, but can also be executed by software. When a series of processing is executed by software, a program constituting the software may execute various functions by installing a computer incorporated in dedicated hardware or various programs. For example, it is installed from a recording medium in a general-purpose personal computer or the like.

  FIG. 12 shows a configuration example of a general-purpose personal computer. This personal computer incorporates a CPU (Central Processing Unit) 1001. An input / output interface 1005 is connected to the CPU 1001 via the bus 1004. A ROM (Read Only Memory) 1002 and a RAM (Random Access Memory) 1003 are connected to the bus 1004.

  The input / output interface 1005 includes an input unit 1006 including an input device such as a keyboard and a mouse for a user to input an operation command, an output unit 1007 for outputting a processing operation screen and an image of a processing result to a display device, a program and various data. A storage unit 1008 including a hard disk drive for storing data, a LAN (Local Area Network) adapter, and the like, and a communication unit 1009 for performing communication processing via a network represented by the Internet are connected. Also, a magnetic disk (including a flexible disk), an optical disk (including a CD-ROM (Compact Disc-Read Only Memory), a DVD (Digital Versatile Disc)), a magneto-optical disk (including an MD (Mini Disc)), or a semiconductor A drive 1010 for reading / writing data from / to a removable medium 1011 such as a memory is connected.

  The CPU 1001 is read from a program stored in the ROM 1002 or a removable medium 1011 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory, installed in the storage unit 1008, and loaded from the storage unit 1008 to the RAM 1003. Various processes are executed according to the program. The RAM 1003 also appropriately stores data necessary for the CPU 1001 to execute various processes.

  In this specification, the step of describing the program recorded on the recording medium is not limited to the processing performed in time series in the order described, but of course, it is not necessarily performed in time series. Or the process performed separately is included.

It is a figure which shows the structure of one Embodiment of the radar apparatus to which this invention is applied. It is intensity distribution of the electromagnetic wave irradiated by the transmission part of FIG. It is a flowchart explaining a measurement process. It is a figure explaining a measurement process. It is a figure explaining operation | movement of a distribution part. It is a figure explaining the path | route difference of the antenna in a receiving part. It is a flowchart explaining the signal processing for collision preliminary action. It is a figure explaining the signal processing for collision preliminary operation. It is a figure explaining the signal processing for collision preliminary operation. It is a figure explaining the signal processing for collision preliminary operation. It is a figure explaining the signal processing for collision preliminary operation. And FIG. 11 is a diagram illustrating a configuration example of a general-purpose personal computer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Radar apparatus 11 Transmitter 12 Receiving part 13 Collision preliminary operation signal processing part 14 Collision preliminary operation control part 36 Antenna 51-1, 51-2 Antenna 71-1 thru | or 71-3 FFT
72 FFT timing control unit for collision determination 73 Doppler frequency calculation unit 74 Distance calculation unit 75 Angle calculation unit 76 Collision determination unit

Claims (8)

In a detection device for detecting an object,
Transmitting means for transmitting a transmission signal by radiating radio waves in a predetermined direction;
Receiving means for receiving a reflected radio wave among radio waves as a transmission signal transmitted by the transmission means, and generating a reception signal from the received radio wave;
Detecting means for detecting the velocity, distance, and angle of the object by sampling the reception signal generated by the receiving means for a predetermined time;
Position specifying means for specifying a relative detection position of the object based on the distance and angle of the object detected by the detection means;
Plotting means for plotting the detection position specified by the position specifying means on a two-dimensional plane;
Frame setting means for setting a frame;
While rotating the frame at a predetermined rotation angle, based on a predetermined determination method using a plurality of plotted detection positions included in the frame for each rotation angle, the presence position where the object exists, and And a direction determining means for determining at least one of the traveling directions. Speed vector setting means for setting the speed vector of the object based on the presence position determined by the direction determination means and the traveling direction;
Speed vector storage means for storing the speed vector set by the speed vector setting means in association with the set time;
The detection apparatus according to claim 1, further comprising: a correction unit that corrects a speed vector set at a current time based on a speed vector stored at a past time by the speed vector storage unit. The detection device according to claim 1, wherein the object is a vehicle. When the speed of the vehicle is higher than a predetermined speed and the presence position is within a predetermined range, or when the speed vector is larger than a predetermined value and the direction is within a predetermined range, a preliminary collision operation is executed. The detection device according to claim 2, further comprising: a collision preliminary operation executing means. Based on the detection position plotted on the plane, the vehicle presence position, and the traveling direction, the noise corresponding to the variation in the plotted detection position and the intensity of the radio wave received by the receiving means The detection apparatus according to claim 4, further comprising: estimation means for estimating the size of the detected vehicle from the variation estimated by the calculation. When the size of the vehicle estimated by the estimating unit is larger than a predetermined size, the collision preliminary motion executing unit reduces the predetermined speed, sets the predetermined range wide, and sets the speed of the object. The detection device according to claim 4, wherein a collision preliminary operation is executed when the speed is higher than the predetermined speed and the presence position is within the predetermined range. In a detection method of a detection device for detecting an object,
A transmission step of transmitting a transmission signal by radiating radio waves in a predetermined direction;
A reception step of receiving a reflected radio wave among radio waves as a transmission signal transmitted by the process of the transmission step, and generating a reception signal from the received radio wave;
A detection step of detecting the speed, distance, and angle of the object by sampling the received signal generated by the receiving means for a predetermined time;
A position specifying step for specifying a relative detection position of the object based on a distance and an angle of the object detected by the detection means;
A plotting step of plotting the detection position specified by the processing of the position specifying step on a two-dimensional plane;
A frame setting step for setting a frame;
While rotating the frame at a predetermined rotation angle, based on a predetermined determination method using a plurality of plotted detection positions included in the frame for each rotation angle, the presence position where the object exists, and A direction determining step for determining at least one of the traveling directions. In a computer that controls a detection device that detects an object,
A transmission step of transmitting a transmission signal by radiating radio waves in a predetermined direction;
A reception step of receiving a reflected radio wave among radio waves as a transmission signal transmitted by the process of the transmission step, and generating a reception signal from the received radio wave;
A detection step of detecting the speed, distance, and angle of the object by sampling the received signal generated by the receiving means for a predetermined time;
A position specifying step for specifying a relative detection position of the object based on a distance and an angle of the object detected by the detection means;
A plotting step of plotting the detection position specified by the processing of the position specifying step on a two-dimensional plane;
A frame setting step for setting a frame;
While rotating the frame at a predetermined rotation angle, based on a predetermined determination method using a plurality of plotted detection positions included in the frame for each rotation angle, the presence position where the object exists, and A program for executing a process including: a direction determining step for determining at least one of the traveling directions.

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