JP2006322856A - Distance measuring device, distance measuring method and distance measuring program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a distance measuring device capable of acquiring detailed distance information. <P>SOLUTION: This distance measuring device 1 can acquire the detailed distance information by being equipped with a radar 60 for detecting the distance to an object positioned in a detection range, an imaging part 10 for generating an image signal group corresponding to a prescribed imaging visual field, a distance operation part 20 for operating the distance in the imaging visual field based on the image signal group outputted from the imaging part 10, and an interpolation part 31 for interpolating an operated value by the distance operation part 20 between detected values by the radar 60. The distance measuring device 1 is also equipped with an operation range setting part 32 for determining a prescribed function passing each detected value, and setting a domain passed by the prescribed function as an operation range of the operation means. The distance operation part 20 detects an image signal having a prescribed condition from within the image signal group corresponding to the operation range set by the operation range setting part 32, and operates the distance to the object positioned in the imaging visual field. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a distance measuring device, a distance measuring method, and a distance measuring program for measuring a distance to an object located within a detection range.

  In recent years, with the popularization of vehicles, various devices mounted on vehicles have been put into practical use. As such a vehicle-mounted device, there is a distance measuring device that measures an inter-vehicle distance between the host vehicle and a preceding vehicle and performs various processes such as alarm output based on the measured inter-vehicle distance.

  Conventionally, as such a distance measuring device, a distance measuring device including a radar has been proposed (see Patent Document 1). This radar distance measuring device detects the presence of an obstacle and the distance to the obstacle by emitting a transmitted wave such as a laser beam in the forward direction and detecting a reflected wave from an obstacle such as a preceding vehicle. is doing.

Japanese Utility Model Publication No. 63-43172

  However, in the conventional radar distance measuring device, the distance between the detection points is wide, and the distance information can be acquired only sparsely. When various processing such as alarm output is performed based on this distance information, In some cases, it was lacking in sex.

  The present invention has been made in view of the above-described drawbacks of the prior art, and an object of the present invention is to provide a distance measuring device capable of acquiring dense distance information in a distance measuring device equipped with a radar. .

  In order to solve the above-described problems and achieve the object, a distance measuring device according to the present invention has a detection means for detecting a distance to an object located within a detection range, and an imaging field of view including at least the detection range. An imaging unit that generates an image signal group corresponding to the imaging field, an arithmetic unit that calculates a distance to an object located in the imaging field based on the image signal group, and a detection value of the detection unit Interpolating means for interpolating the calculated value of the calculating means is provided.

  In addition, the distance measuring device according to the present invention includes a calculation range setting unit that obtains a predetermined function that passes between the detection values and sets a region through which the predetermined function passes as a calculation range in the calculation unit, and the calculation unit includes: An image signal having a predetermined condition is detected from the image signal group corresponding to the calculation range, and a distance to an object located in the imaging field is calculated.

  The distance measuring apparatus according to the present invention is characterized in that the predetermined function is a linear function.

  The distance measuring apparatus according to the present invention further includes a calculation range setting unit that sequentially sets a calculation range in the calculation unit based on the detection value or the calculation value adjacent to the image signal to be calculated. Is characterized in that an image signal having a predetermined condition is detected from the image signal group corresponding to the calculation range, and a distance to an object located in the imaging field is calculated.

  Further, in the distance measuring device according to the present invention, the imaging means has the first image signal group imaged through the first optical path and the second image signal group imaged through the second optical path. The calculation range setting means sets the calculation range in the second image signal group corresponding to an arbitrary image signal of the first image signal group, and the calculation means sets the second image signal in the second image signal group. An image signal matching the arbitrary image signal is detected from the calculation range in the image signal group, and the object located in the imaging field is detected based on a distance from the arbitrary image signal in the detected image signal. The distance is calculated.

  The distance measuring device according to the present invention is characterized in that the imaging means includes a pair of optical systems and a pair of imaging elements that convert optical signals output from the pair of optical systems into electrical signals. To do.

  In the distance measuring device according to the present invention, the imaging means has a pair of light guide optical systems and an imaging region corresponding to each light guide optical system, and takes each optical signal guided by each light guide optical system. And an image pickup device for converting into an electric signal in the region.

  The distance measuring device according to the present invention is characterized in that the distance measuring device is mounted on a vehicle.

  Further, the distance measurement method according to the present invention is a distance measurement method for measuring a distance to an object located within a detection range, a detection step for detecting a distance to an object located within the detection range, and at least the detection An imaging step for generating a group of image signals corresponding to an imaging field including a range, a calculation step for calculating a distance to an object located in the imaging field based on the image signal group, and a calculation value in the calculation step An interpolation step of interpolating between detection values in the detection step.

  The distance measurement program according to the present invention is a distance measurement program for measuring a distance to an object located within a detection range, a detection procedure for detecting a distance to an object located within the detection range, and at least the detection An imaging procedure for generating an image signal group corresponding to an imaging field including a range, an arithmetic procedure for calculating a distance to an object located in the imaging field based on the image signal group, and an arithmetic value in the calculation procedure An interpolation procedure for interpolating between detection values in the detection procedure.

  According to the distance measuring apparatus of the present invention, the calculation means calculates the distance to the object located in the imaging field based on the image signal group generated by the imaging means, and the calculation means calculates between the detection values of the radar. By providing the interpolation means for interpolating the value, detailed distance information can be acquired, and various safe driving support processes based on this distance information can be accurately performed. Further, by using the distance measurement method and the distance measurement program according to the present invention, detailed distance information can be acquired.

  Hereinafter, a distance measuring apparatus according to an embodiment of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments. In the description of the drawings, the same parts are denoted by the same reference numerals.

  First, the distance measuring device according to the present embodiment will be described by taking a distance measuring device mounted on a vehicle and outputting distance information within a detection range as an example. Based on the distance information output from the distance measuring device, various safe driving support processes are performed by other devices. In the distance measuring apparatus according to the present embodiment, the calculation value obtained by the distance calculation unit performing the distance calculation is interpolated between the detection values of the radar. FIG. 1 is a block diagram showing a schematic configuration of the distance measuring apparatus according to the present embodiment.

  As shown in FIG. 1, the distance measuring apparatus 1 according to the present embodiment has an imaging field including at least a detection range of the radar 60, and generates an image signal group corresponding to the imaging field, A distance calculation unit 20 that calculates a distance to an object located in the imaging field based on a group of image signals generated by the imaging unit 10, and a control that controls each process and each operation of each component that constitutes the distance measuring device. Unit 30, an output unit 40 that outputs various information including distance information, a storage unit 50 that stores various information including distance information, and a radar 60 that detects a distance to an object located within a predetermined detection range, Is provided. The imaging unit 10, the distance calculation unit 20, the output unit 40, the storage unit 50, and the radar 60 are electrically connected to the control unit 30. Further, the control unit 30 includes an interpolation unit 31 having a calculation range setting unit 32.

  The imaging unit 10 includes a right camera 11a and a left camera 11b. The right camera 11a and the left camera 11b output image signal groups corresponding to respective imaging fields. The right camera 11a and the left camera 11b include lenses 12a and 12b, image sensors 13a and 13b, analog / digital (A / D) converters 14a and 14b, and frame memories 15a and 15b, respectively. The lenses 12a and 12b collect light incident from a predetermined viewing angle. The image sensors 13a and 13b arranged corresponding to the lenses 12a and 12b are realized by a CCD or a CMOS, and detect the light transmitted through the lenses 12a and 12b and convert it into an analog image signal. The A / D converters 14a and 14b convert analog image signals output from the image sensors 13a and 13b into digital image signals. The frame memories 15a and 15b store digital image signals output from the A / D conversion units 14a and 14b, and a digital image signal group corresponding to one captured image is used as an image signal group corresponding to the imaging field of view as needed. Output.

  The distance calculation unit 20 processes the image signal group output from the imaging unit 10 to calculate the distance to an object located in the imaging field of view, and the image signal group output from the imaging unit 10. And a memory 22 for storage. The distance calculation unit 20 detects an image signal having a predetermined condition from the image signal group corresponding to the calculation range set by the calculation range setting unit 32, and calculates a distance to an object located in the imaging field of view. .

The computing unit 21 computes the distance to the object located in the imaging field based on the image signal group output from the imaging unit 10 using the stereo method. The computing unit 21 detects an image signal that matches an arbitrary image signal in the left image signal group output from the left camera 11b from the right image signal group output from the right camera 11a, and detects the detected image signal. The distance is calculated by the principle of triangulation based on the amount of movement I from an arbitrary image signal. The movement amount described here indicates a parallax amount generally referred to. The calculating part 21 calculates | requires the distance R from the imaging part 10 to the vehicle C which is a target object using the following (1) Formula. In the equation (1), f is the focal length of the lenses 12a and 12b, and L is the width between the optical axes of the lenses 12a and 12b. Further, the movement amount I may be obtained based on the number of moved pixels and the pixel pitch.
R = f · L / I (1)
The calculation unit 21 calculates the distance R corresponding to each image signal, and the distance calculation unit 20 outputs the calculated value and the position information in the imaging field of view to the control unit 30 in association with each other. For simplicity, the parallel stereo is described here, but the optical axes intersect with an angle, the focal length is different, the positional relationship between the image sensor and the lens is calibrated, and so on. It is also possible to realize parallel stereo by arithmetic processing.

  The control unit 30 is realized by a CPU or the like that executes a processing program stored in the storage unit 50, and controls each process or operation of the imaging unit 10, the distance calculation unit 20, the output unit 40, the storage unit 50, and the radar 60. To do. The control unit 30 performs predetermined input / output control on information input / output to / from each of these components and performs predetermined information processing on the information.

  The interpolation unit 31 interpolates the calculation value output from the calculation unit 20 between the detection values of the radar 60 based on the detection information 51 detected from the radar 60 and the calculation information 52 output from the distance calculation unit 20. To do. The interpolation unit 31 outputs a detection result obtained by interpolating a calculation value between detection values of the radar 60 as distance information.

  In addition, the interpolation unit 31 includes a calculation range setting unit 32 that sets a calculation range in the distance calculation unit 20 based on the detection information 51 of the radar 60. The calculation range setting unit 32 obtains a predetermined function passing between the detection values, and sets a region through which the predetermined function passes as a calculation range in the calculation unit 20. In the present embodiment, description will be made regarding a case where the calculation range setting unit 32 obtains a linear function passing between the detection values and sets a region through which the linear function passes as a calculation range in the calculation unit 20.

  The output unit 40 is realized by a liquid crystal display, an organic electroluminescence display, or the like, and displays and outputs various display information such as an image captured by the imaging unit 10 in addition to the distance information. Moreover, the output part 40 is further provided with a speaker, and outputs various audio | voice information, such as a warning audio | voice which alert | reports that it approached the preceding vehicle C other than distance information.

  The storage unit 50 includes a ROM in which various types of information such as processing programs are stored in advance, and a RAM in which calculation parameters for each processing, various types of information output from various components, writing information, audio information, and the like are stored. . For example, the storage unit 50 stores detection information 51 output from the radar 60, calculation information 52 output from the distance calculation unit 20, and distance information 53 output from the interpolation unit 31.

  The radar 60 transmits a predetermined transmitted wave, receives a reflected wave reflected by the surface of the object, and a distance from the radar 60 to the object that reflects the transmitted wave based on the transmitted state and the received state. And the direction in which the object is located. The radar 60 determines the distance based on the transmission angle of the transmitted wave, the incident angle of the reflected wave, the reception intensity of the reflected wave, the time from transmission of the transmitted wave to reception of the reflected wave, frequency change of the reflected wave, and the like. The distance from the measuring device 1 to the object reflecting the transmitted wave is detected. The radar 60 outputs detection data 51 in which a detection distance value to an object located within the detection range is associated with position information within the detection range to the control unit 30. The radar 60 transmits laser light, infrared rays, or millimeter waves as a transmission wave.

  Next, processing operations performed until the interpolation unit 31 outputs the distance information 53 among the processing operations performed by the distance measuring device 1 will be described. FIG. 2 is a flowchart showing a processing procedure until the interpolation unit 31 completes the output of the distance information 53 in the distance measuring apparatus 1.

  As shown in FIG. 2, first, the control unit 30 instructs the radar 60 to perform a detection process for detecting a distance to an object located within the detection range (step S102). The radar 60 detects the distance to an object located within the detection range in accordance with an instruction from the control unit 30 and outputs detection information 51 to the control unit 30. The control unit 30 receives the detection information 51 output from the radar 60 (step S104).

  Thereafter, the calculation range setting unit 32 obtains a linear function passing between the detection values based on the detection information 51 received from the radar 60, and sets a region through which the linear function passes as a calculation range in the calculation unit 20. A range setting process is performed (step S106). Here, the calculation range setting unit 32 sets a calculation range corresponding to each image signal of the image signal group output from the imaging unit 10.

  Next, the control unit 30 instructs the imaging unit 10 to perform an imaging process (step S108). The imaging unit 10 performs imaging processing according to instructions from the control unit 30, and the right camera 11a and the left camera 11b output image signal groups corresponding to the respective imaging fields.

  Thereafter, the control unit 30 instructs the calculation unit 20 to perform a distance calculation process (step S110). In accordance with an instruction from the control unit 30, the calculation unit 21 selects the left image signal from the image signal group corresponding to the calculation range set by the calculation range setting unit 32 among the right image signal group output from the right camera 11a. An image signal matching an arbitrary image signal in the group is detected, and a distance calculation corresponding to the arbitrary image signal is performed. The distance calculation unit 20 outputs calculation information 52 to the control unit 30 after the calculation unit 21 performs a distance calculation on each image signal. The control unit 30 receives the calculation information 52 output from the distance calculation unit 20 (step S112).

  The interpolation unit 31 performs an interpolation process for interpolating the calculation values output from the calculation unit 20 between the detection values of the radar 60 (step S114). The control unit 30 outputs the interpolation result obtained by interpolating the calculation value between the detection values as the distance information 53 (step S116).

  Next, the calculation range setting process performed by the calculation range setting unit 32 will be specifically described. FIG. 3 is a diagram illustrating an example of a detectable range in the radar 60. In FIG. 3, a location where the radar 60 detects a distance to an object located within the detection range is indicated as a radar detection point “●”. 3 superimposes the detectable range of the radar 60 and the image signal group output from the imaging unit 10, and each cell in FIG. 3 is, for example, a left image signal group output from the left camera 11b. Corresponds to each image signal. Hereinafter, in the calculation range setting process, the calculation range in the distance calculation unit 20 is set for the image signals 525b and 535b located between the radar detection point 515 and the radar detection point 555 in the image signal group shown in FIG. A case of setting will be described as an example.

  FIG. 4 is a diagram for explaining the calculation range setting process shown in FIG. 4, the horizontal axis indicates the number of pixel columns in the pixel row where the radar detection points 515 and 555 are located in the image signal group illustrated in FIG. 3, and the vertical axis indicates the radar detection points 515 and 555 detected by the radar 60. Indicates the detection distance. In FIG. 4, the pixel column “1” is the number of columns corresponding to the radar detection point 515, and the pixel column “5” is the number of columns corresponding to the radar detection point 555. The image signal 525b corresponds to the pixel column “2”, and the image signal 535b corresponds to the pixel column “3”.

  First, the calculation range setting unit 32 obtains a linear function passing through the radar detection point 515 and the radar detection point 555. In this case, as shown in FIG. 4, the linear function passing through the radar detection point 515 and the radar detection point 555 is a straight line la.

  The calculation range setting unit 32 obtains a region Sa formed by adding the predetermined value e above and below the straight line la. For example, the predetermined value e is determined based on the probability that each distance value is distributed between the radar detection values.

  Next, the calculation range setting unit 32 sets a calculation range for the image signals 525b and 535b based on the area Sa. Specifically, the calculation range setting unit 32 obtains the distance width Y2 on the region Sa in the pixel column “2” as the calculation range corresponding to the image signal 525b. The calculation range setting unit 32 sets an image signal group corresponding to the distance width Y2 in the right image signal group as a calculation range corresponding to the image signal 525b. With reference to FIG. 5, the calculation range corresponding to the image signal 525b will be specifically described.

  FIG. 5 is a diagram illustrating a right image signal group output from the right camera 11a and a left image signal group output from the left camera 11b. The calculation range setting unit 32 sets the image signal group corresponding to the distance width Y2 shown in FIG. 4 in the right image signal group 16a as the calculation range corresponding to the image signal 525b in the left image signal group 16b. In this case, among the right image signal group 16a, the image signal group corresponding to the distance width Y2 shown in FIG. 4 is, for example, an image signal group located in the region S11 shown in FIG. Thereafter, the calculation unit 21 detects an image signal that matches the image signal 525b from the calculation range set by the calculation range setting unit 32, that is, the image signal group located in the region S11 of the right image signal group 16a. The computing unit 21 obtains the movement amount I from the detected position of the image signal, and computes the distance value corresponding to the image signal 525b using the equation (1). As a result, a calculation point 525 shown in FIG. 7 is obtained.

  When the calculation range setting unit 32 sets the calculation range corresponding to the image signal 535b, the distance width Y3 on the region Sa in the pixel column “3” is obtained, and the distance width Y2 in the right image signal group is obtained. A corresponding image signal group is set as a calculation range corresponding to the image signal 525b. In this case, the calculation range setting unit 32 selects an image signal group corresponding to the distance width Y3 shown in FIG. 4 among the right image signal group 16a, for example, an image signal group located in the region S22 shown in FIG. The calculation range corresponding to the image signal 535b in the group 16b is set. Thereafter, the calculation unit 21 detects an image signal that matches the image signal 535b from the image signal group located in the region S22 of the right image signal group 16a, and calculates a distance value corresponding to the image signal 525b. As a result, a calculation point 535 shown in FIG. 7 is obtained.

  Further, when setting the calculation range of each image signal located between the radar detection point 555 and the radar detection point 595 shown in FIG. 3, as shown in FIG. 4, the radar detection point 555 and the radar detection point 595 are set. And a calculation range is set for each image signal based on a region Sb centered on the straight line lb. As a result of the distance calculation unit 20 sequentially performing distance calculation processing on each image signal, as shown in FIG. 7, distance values of the calculation points located between the radar detection points 515, 555, and 595 are obtained. Become. As described above, the calculation range setting unit 32 sets the calculation range corresponding to each image signal to be calculated based on the radar detection point. The distance calculation unit 20 matches the image signal to be calculated in the left image signal group 11b from among the image signals located within the calculation range set by the calculation range setting unit 32 in the right image signal group 11a. The image signal to be detected is detected, and the distance calculation is performed.

  Thereafter, in the interpolation process (step S114) shown in FIG. 2, the interpolation unit 31 calculates points calculated by the distance calculation unit 20 between the radar detection points (shown as “●”) as shown in FIG. Interpolation processing is performed by interpolating (the calculation point is indicated by “◯”). The interpolation unit 31 outputs the interpolation result of this interpolation process as distance information 53.

  As described above, in the distance measurement device 1 according to the present embodiment, detailed distance information is acquired because the distance information 53 obtained by interpolating the calculation value in the distance calculation unit 20 is output between the detection points in the radar 60. It becomes possible. As a result, the distance measuring device 1 can accurately perform various safe driving support processes based on the distance information 53.

  In the conventional distance measuring device, when the distance calculation unit performs the distance calculation process on the image signal 1162b of the left image signal group 116b illustrated in FIG. 9, the image signal that matches the image signal 1162b is input to the image signal. It was necessary to detect from all the image signals of the right image signal group 116a located on the same straight line as an arbitrary straight line passing through 1662b. That is, conventionally, the distance calculation unit needs to detect an image signal that matches the image signal 1162b from the region S10 including all the image signals located on the same straight line as the image signal 1162b. .

  On the other hand, in the distance measuring device 1 according to the present embodiment, the distance calculation unit 20 includes the image signal included in the calculation range set by the calculation range setting unit 32 in the right image signal group 16a. An image signal that matches the image signal that is the object of calculation of the left image signal group is searched. For this reason, in the distance measuring device 1 according to the present embodiment, compared to the conventional distance measuring device, the distance calculation unit 20 narrows the detection range of an image signal that matches an arbitrary image signal, and matching is studied. The number of image signals to be reduced is reduced. Therefore, in the distance measuring device 1 according to the present embodiment, it is possible to shorten the processing time required to detect the image signal as compared with the conventional distance measuring device. As a result, the distance measurement device 1 according to the present embodiment can acquire distance information more quickly than a conventional distance measurement device.

  As shown in FIG. 10, the calculation range setting unit 32 may set the calculation range based on a region Sc formed based on a predetermined probability distribution with the straight line la as the center. In this case, as shown in FIG. 10, the calculation range for the image signal 525b is set based on the distance Y22 on the region Sc in the pixel column “2”, and the calculation range for the image signal 535b is the pixel column “3”. Is set based on the distance Y23 on the area Sc.

  In the present embodiment, the calculation range setting unit 32 obtains a linear function that passes between the radar detection values, and sets the calculation range in the distance calculation unit 20 based on the region through which the linear function passes. Not limited to this, a quadratic function or a cubic function passing between the radar detection values may be obtained, and it is sufficient to obtain a predetermined function having a high probability of being close to the distance value between the radar detection points through the radar detection values.

  Further, in the present embodiment, the calculation range setting unit 32 obtains a linear function that passes between the radar detection values, and the calculation range in the distance calculation unit 20 is set based on the region through which the linear function passes. However, the present invention is not limited to this, and the calculation range of the distance calculation unit 20 may be sequentially set based on the radar detection value or the calculation value located in the vicinity of the image signal to be calculated.

  For example, the case where the calculation range setting unit 32 sets the calculation range for the image signal located in the pixel column “2” illustrated in FIG. 11 will be described. In this case, the calculation range setting unit 32 sets the region S2 based on the radar detection point 515A adjacent to the image signal located in the pixel row “2”. For example, the region S2 is determined based on the distribution probability of the calculated value of the image signal located in the pixel column “2”. Then, the calculation range setting unit 32 sets the image signal group corresponding to the distance width Y32 on the region S2 as the calculation range of the image signal located in the pixel column “2”. The distance calculation unit 20 detects a predetermined image signal from the image signal group corresponding to the distance width Y32, and obtains a distance value at the calculation point 525A by performing distance calculation processing.

  In addition, when the calculation range is set for the image signal located in the pixel column “3”, the calculation range setting unit 32 calculates the distance calculation unit 20 adjacent to the image signal located in the pixel column “3”. A region S3 is set based on the calculated calculation point 525A, and a calculation range corresponding to the distance width Y33 of the region S3 is set. Further, when the calculation range is set for the image signal located in the pixel column “5”, the calculation range can be set based on the calculation point 545A or the radar detection point 565A adjacent to the pixel column “5”. . As described above, the calculation range setting unit 32 may sequentially set the calculation range based on the radar detection points or calculation points located in the vicinity of the image signal to be calculated.

  FIG. 3 referred to in the description of the distance measuring apparatus 1 according to the embodiment is a diagram in which the detection range in the radar 60 and the imaging range in the imaging unit 10 are overlapped, and any of the regions where the image signals are located. Although the case where the radar detection point corresponds is described, the radar detection point does not necessarily match the position of each image signal output from the imaging unit 10. In this case, the calculation range setting unit 32 uses the same pixel row as the image signal to be calculated using a primary interpolation method or the like based on a plurality of radar detection values located in the vicinity of the image signal to be calculated. The radar detection values may be interpolated, and the calculation range may be set using the interpolation detection values.

  In the present embodiment, the matching between the positional relationship in the image information group captured by the imaging unit 10 and the positional relationship in the detection range in the radar 60 is obtained in advance as follows, and each process is performed. For example, the distance measuring apparatus 1 performs an imaging process in the imaging unit 10 and a detection process in the radar 60 on an object whose shape is known, and the position of the known object in the imaging unit 10 and the position of the known object in the radar 60. Ask for. Thereafter, the distance measuring apparatus 1 obtains a relationship between the position of the known object in the imaging unit 10 and the position of the known object in the radar 60 using a least square method or the like, and in the image information group captured by the imaging unit 10 The positional relationship and the positional relationship in the detection range of the radar 60 are matched.

  Further, in the distance measuring device 1, even when the imaging origin of the imaging unit 10 and the detection origin of the radar 60 are misaligned, the distance from the imaging point and the detection point to the distance measuring device 1 is sufficiently large. In this case, it can be considered that the imaging origin and the detection origin almost overlap each other. Further, when the positional relationship in the image information group captured by the imaging unit 10 and the positional relationship in the detection range in the radar 60 are accurately matched, the deviation between the imaging origin and the detection origin is performed by geometric transformation. It is also possible to correct.

  Moreover, although the imaging part 10 provided with a pair of imaging device 13a, 13b corresponding to each of a pair of lenses 12a, 12b was demonstrated as an imaging part in this Embodiment, it is not restricted to this but is shown in FIG. In addition, the imaging unit 110 may include a pair of light guiding optical systems and an imaging element that has an imaging region corresponding to each optical system and converts the electrical signal in each imaging region guided by each light guiding optical system. For example, see JP-A-8-171151 by the present applicant). As illustrated in FIG. 12, the imaging unit 110 converts the light collected by the pair of mirrors 111a and 111b, the mirrors 112a and 112b corresponding to the mirrors 111a and 111b, the lens 112c, and the lens 112c into an analog image. An image sensor 113 that converts the signal into a signal, an A / D converter 114 that changes an analog image signal output from the image sensor 113 into a digital image signal, and a frame memory 115 that stores the digital signal are provided. The mirrors 111a and 111b receive light from a subject such as the vehicle C, and the mirrors 112a and 112b reflect the light received by the mirrors 111a and 111b to the lens 112c. Therefore, an image corresponding to each optical system is formed on the image sensor 113. Therefore, the imaging unit 110 outputs an image 118 including an image 118a and an image 118b as shown in FIG. Based on such images 118a and 118b, the distance calculation unit 20 can calculate a distance value corresponding to each image signal.

  Further, in the present embodiment, the distance measuring device 1 including a plurality of cameras has been described. However, the present invention is not limited to this, and the present invention may be applied to a distance measuring device including a single camera. In this case, the distance calculation unit 20 uses, for example, a shape from focus method, a shape from defocus method, a shape from motion method, or a shape from shading method based on the image signal group output from the imaging unit. Calculate the distance within. In this case, the distance calculation unit 20 calculates the distance within the imaging field of view within the calculation range set by the calculation range setting unit 32 based on the radar detection point. The shape from focus method is a method for obtaining a distance from a focus position when the focus is best achieved. The shape from defocus method is a method of obtaining a relative blur amount from a plurality of images having different in-focus distances and obtaining a distance based on a correlation between the blur amount and the distance. The shape from motion method is a method for obtaining a distance to an object on the basis of the movement trajectory of a predetermined feature point in a plurality of temporally continuous images. The shape-from-shading method is a method for obtaining a distance to an object based on shading in an image, reflection characteristics of a target object, and light source information.

  The imaging unit 10 may constitute a so-called trinocular stereo camera structure, or may constitute a so-called four-eye stereo camera structure. When the imaging unit has a three-eye stereo camera structure or a four-eye stereo camera structure, a distance measurement device that can obtain a reliable and stable distance calculation result by performing a three-dimensional reconstruction process or the like is realized. It becomes possible to do. In particular, when a plurality of cameras are arranged so as to have a baseline length in two directions, even when a plurality of objects are arranged in a complicated configuration, three-dimensional reconstruction processing is possible, and the distance calculation result is stable. Can be obtained. In this case, it is possible to employ a multi-baseline method in which a plurality of cameras are arranged in the base length direction in one direction, and highly accurate distance measurement can be realized.

  In the present embodiment, the distance measuring apparatus 1 including the radar 60 has been described. However, instead of the radar 60, a light source such as a semiconductor laser element, a light emitting diode, or a laser diode that transmits infrared light or visible light is used. A distance measuring device having a detector realized by a light receiving element such as a photosensor that receives reflected light from an object, or using light waves, microwaves, millimeter waves, ultrasonic waves, etc. It may be a distance measuring device provided with a radar type detector that measures the distance from the delay of the reflected wave.

  Further, as the present embodiment, the distance measuring device 1 mounted on the vehicle has been described as an example. However, the present invention is not limited to this, and may be applied to a distance measuring device mounted on another moving body. Further, the present invention is not limited to the distance measuring device mounted on the moving body, and may be applied to a distance measuring device that measures the distance within the detection range in a state of being fixed at a predetermined position, for example.

It is a block diagram showing a schematic structure of a distance measuring device concerning an embodiment. It is a flowchart which shows the process sequence until the output of distance information is completed in the distance measuring device shown in FIG. It is a figure explaining the detectable range of the radar shown in FIG. It is a figure explaining the calculation range setting process shown in FIG. It is a figure explaining the distance calculation process which the distance calculation part shown in FIG. 1 performs. It is a figure explaining the distance calculation process which the distance calculation part shown in FIG. 1 performs. It is a figure explaining the interpolation process shown in FIG. It is a figure which shows an example of the distance information shown in FIG. It is a figure explaining the distance calculation process which the distance calculating part in the conventional distance measuring device performs. It is a figure explaining the calculation range setting process shown in FIG. It is a figure explaining the calculation range setting process shown in FIG. It is a block diagram which shows the other example of schematic structure of the imaging part shown in FIG. It is a figure which shows an example of the image output from the imaging part shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Distance measuring device 10 Imaging part 11a Right camera 11b Left camera 12a, 12b, 112c Lens 13a, 13b, 113 Imaging element 14a, 14b, 114 A / D conversion part 15a, 15b, 115 Frame memory 16a, 116a Right image signal group 16b, 116b Left image signal group 20 Distance calculation unit 21 Calculation unit 22 Memory 30 Control unit 31 Interpolation unit 32 Calculation range setting unit 40 Output unit 50 Storage unit 51 Detection information 51a Detectable range 52 Calculation information 53, 53a Distance information 60 Radar 111a, 111b, 112a, 112b Mirror 118, 118a, 118b Image 525b, 535b, 1162b Image signal 515, 515A, 555, 565A, 595 Radar detection point 525, 525A, 535, 535A, 545A, 555A Calculation point Vehicle

Claims (10)

Detection means for detecting a distance to an object located within the detection range;
An imaging unit having an imaging field including at least the detection range and generating an image signal group corresponding to the imaging field;
A computing means for computing a distance to an object located in the imaging field based on the image signal group;
Interpolation means for interpolating the calculation value of the calculation means between the detection values of the detection means;
A distance measuring device comprising: A calculation function setting unit that obtains a predetermined function passing between the detection values and sets a region through which the predetermined function passes as a calculation range in the calculation unit,
The calculation means detects an image signal having a predetermined condition from the image signal group corresponding to the calculation range, and calculates a distance to an object located in the imaging field of view. The distance measuring apparatus according to 1.   The distance measuring apparatus according to claim 2, wherein the predetermined function is a linear function. A calculation range setting means for sequentially setting a calculation range in the calculation means based on the detection value or the calculation value located in the vicinity of an image signal to be calculated;
The calculation means detects an image signal having a predetermined condition from the image signal group corresponding to the calculation range, and calculates a distance to an object located in the imaging field of view. The distance measuring apparatus according to 1. The imaging means generates a first group of image signals captured through a first optical path and a second group of image signals captured through a second optical path;
The calculation range setting means sets the calculation range in the second image signal group corresponding to an arbitrary image signal of the first image signal group,
The calculation means detects an image signal that matches the arbitrary image signal from the calculation range in the second image signal group, and based on a distance from the arbitrary image signal in the detected image signal The distance measuring device according to any one of claims 2 to 4, wherein a distance to an object located in the imaging field is calculated. The imaging means includes
A pair of optical systems;
A pair of image sensors that convert optical signals output by the pair of optical systems into electrical signals;
The distance measuring device according to any one of claims 1 to 5, further comprising: The imaging means includes
A pair of light guiding optical systems;
An imaging device that has an imaging region corresponding to each light guide optical system and converts an optical signal guided by each light guide optical system into an electrical signal in each imaging region;
The distance measuring device according to any one of claims 1 to 5, further comprising:   The distance measuring apparatus according to claim 1, wherein the distance measuring apparatus is mounted on a vehicle. In a distance measurement method for measuring the distance to an object located within the detection range,
A detection step of detecting a distance to an object located within the detection range;
An imaging step for generating an image signal group corresponding to an imaging field including at least the detection range;
A calculation step of calculating a distance to an object located in the imaging field based on the image signal group;
An interpolation step of interpolating the calculated values in the calculating step between the detected values in the detecting step;
A distance measurement method comprising: In a distance measurement program that measures the distance to an object located within the detection range,
A detection procedure for detecting a distance to an object located within the detection range;
An imaging procedure for generating an image signal group corresponding to an imaging visual field including at least the detection range;
A calculation procedure for calculating a distance to an object located in the imaging field based on the image signal group,
An interpolation procedure for interpolating the calculation values in the calculation procedure between the detection values in the detection procedure;
The distance measurement program characterized by including.

Images