JP2006322852A - Ranging device, ranging technique, and ranging program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ranging device capable of acquiring highly precise and detailed range information quickly. <P>SOLUTION: The ranging device 1 is equipped with a range arithmetic section 20 calculating the range to an object located within an imaging field of view based on an imagery signal group output from an imaging section 10, a radar 60 detecting the range to the object located in detection range, and an interpolating section 31 creating the range data combining the in-range data interpolated with the calculated value of the range arithmetic section 20 between the detected values of the radar 60 with the outlying data consisting of the calculated values corresponding to the outlying range of the radar 60. Also, the interpolating section 31 creates the range data using the previous outlying data, up to the finalization of acquiring of the outlying data in now processing. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

  Conventionally, an optical distance measuring device having an image sensor has been proposed as a distance measuring device (see Patent Document 2). The distance measuring device includes an imaging unit having two left and right lenses and an image sensor corresponding to each of the left and right lenses. Then, among each image output from the image sensor, an image signal that matches an arbitrary image signal in the other image is detected from one image, and based on the amount of movement in the detected image signal, The distance to the object is calculated for each image signal using the principle of triangulation.

Japanese Utility Model Publication No. 63-43172 Japanese Examined Patent Publication No. 63-46363

  However, in the distance measuring device equipped with the conventional radar, the detection range is narrow and the distance between the detection points is wide, and the distance information can only be acquired sparsely. For this reason, when various processing such as alarm output is performed based on such distance information, accuracy may be lacking.

  In addition, the conventional optical distance measuring device has more calculation points and can acquire detailed distance information compared to a distance measuring device equipped with a radar. To achieve this, enormous calculation time is required. For this reason, the conventional optical distance measurement device thins out the calculation time and calculation pixels, narrows the measurement distance range, calculates only the edge portion, and reduces the distance resolution in order to output the calculation results in real time. And so on. As a result, the conventional optical distance measuring device cannot quickly acquire detailed distance information with high accuracy, and cannot perform various processes using the distance image accurately and at appropriate timing. It was.

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

  In order to solve the above-described problems and achieve the object, a distance measuring device according to the present invention includes a detection unit that detects a distance to an object located within a predetermined detection range, and an imaging field including at least the detection range. An imaging means for generating an image signal group corresponding to the imaging visual field, an arithmetic means for calculating a distance to an object located in the imaging visual field based on the image signal group, and detection by the detection means Interpolation means for generating distance data by combining data within the detection range obtained by interpolating between the values with the calculation value of the calculation means and data outside the detection range including the calculation value corresponding to outside the detection range. It is characterized by that.

  Further, in the distance measuring device according to the present invention, the interpolation means generates the distance data using the previous out-of-detection range data until the completion of acquisition of the out-of-detection range data being currently processed. Features.

  The distance measuring apparatus according to the present invention is characterized in that the interpolation means acquires the data within the detection range while the detection means acquires the detection value.

  The distance measuring device according to the present invention further comprises detection range search means for searching for a detection range of the detection means, and the interpolation means is configured to detect the data within the detection range and the data based on the search result of the detection range search means. Data outside the detection range is acquired.

  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. And the arithmetic means detects an image signal that matches an arbitrary image signal of the first image signal group from the second image signal group, and the arbitrary image in the detected image signal A distance to an object located in the imaging field of view is calculated based on a movement amount from the signal.

  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 predetermined range, wherein the detection step detects the distance to an object located within a predetermined detection range, An imaging step for generating an image signal group corresponding to an imaging field including a detection range, an arithmetic step for calculating a distance to an object located in the imaging field based on the image signal group, and a detection step detected An interpolation step for generating distance data by combining data within the detection range interpolated with the calculation value calculated in the calculation step between the detection values and data outside the detection range consisting of the calculation value corresponding to the outside of the detection range; , Including.

  Further, the distance measurement program according to the present invention is a distance measurement program for measuring a distance to an object located within a predetermined range, a detection procedure for detecting a distance to an object located within a predetermined detection range, and at least the above-mentioned An imaging procedure for generating an image signal group corresponding to an imaging field including a detection range, an arithmetic procedure for calculating a distance to an object located in the imaging field based on the image signal group, and detected in the detection procedure An interpolation procedure for generating distance data by combining data within the detection range interpolated with the calculation values calculated in the calculation procedure between the detection values and data outside the detection range consisting of the calculation values corresponding to outside the detection range; , Including.

  According to the distance measuring device of the present invention, the data within the detection range obtained by interpolating between the detection values of the detection means with the calculation value of the calculation means and the data outside the detection range composed of calculation values corresponding to outside the detection range are combined. By providing an interpolation means for generating distance data, it is possible to quickly acquire detailed distance information with high accuracy, and based on this distance information, safe driving support processing such as warning output in various processing is accurately and accurately performed. It is possible to carry out at a proper timing. Further, by using the distance calculation method and the distance calculation program according to the present invention, it is possible to quickly acquire detailed distance information with high accuracy.

  Hereinafter, a distance measuring device according to an embodiment of the present invention will be described with reference to the drawings, taking a distance measuring device mounted on a vehicle as an example. Various safe driving support processes are performed by other devices based on the distance information output by the distance measuring device. In addition, this invention is not limited by this embodiment. In the description of the drawings, the same parts are denoted by the same reference numerals.

(Embodiment 1)
First, the distance measuring apparatus according to the first embodiment will be described. The distance measuring apparatus according to the first embodiment combines the detection range data obtained by interpolating between the detection values of the radar with the calculation value of the distance calculation unit and the out-of-detection range data including calculation values corresponding to outside the detection range. Generated distance data. FIG. 1 is a block diagram illustrating a schematic configuration of the distance information device according to the first embodiment.

  As shown in FIG. 1, the distance measuring apparatus 1 according to the first embodiment has an imaging field including at least a detection range of the radar 60, and an imaging unit 10 that generates an image signal group corresponding to the imaging field. The distance calculation unit 20 that calculates the distance to the object located in the imaging field based on the image signal group generated by the imaging unit 10 and each process and operation of each component that constitutes the distance measuring device are controlled. A control unit 30, an output unit 40 that outputs various types of information including distance information, a storage unit 50 that stores various types of information including distance information, and a radar 60 that detects the distance to an object located within a predetermined detection range. With. 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. The distance calculation unit 20 includes a calculation unit 21 and a memory 22. The control unit 30 includes an interpolation unit 31 having a calculation range setting unit 33 and a timer 34 for measuring time.

  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, the image signal group output from the imaging unit 10, And a memory 22 for storing a calculation value calculated by the calculation unit 21.

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 at. 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 formula (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 outputs calculation data 53 in which the calculation value and the position information in the imaging field of view correspond to each other to the control unit 30. Here, since the calculation data 53 output by the distance calculation unit 20 is calculation data 53 corresponding to each calculation range set by the calculation range setting unit 33, the calculation ranges of the respective calculation data 53 to be output are different. There is a case. 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 interpolating unit 31 inter-detection value data obtained by interpolating between detection values in the detection data 51 of the radar 60 with the calculation value of the distance calculation unit 20, and out-of-detection range data composed of calculation values corresponding to outside the detection range of the radar 60. The distance data 54 combining the above is generated. Further, the interpolation unit 31 creates the distance data 54 using the previous out-of-detection range data until the completion of acquisition of the out-of-detection range data being currently processed. Further, the interpolation unit 31 acquires the data within the detection range while the radar 60 acquires the detection value.

  The calculation range setting unit 33 sets the calculation range in the distance calculation unit 20 based on the time value of the timer 34. The distance calculation unit 20 performs calculation processing in the calculation range set by the calculation range setting unit 33.

  The calculation range setting unit 33 sets a calculation range that is the same as the detection range of the radar 60 when the measured value T of the timer 34 is less than the predetermined time Ts. In this case, the distance calculation unit 20 applies to an image signal corresponding to a calculation range that is the same as the detection range of the radar 60 set by the calculation range setting unit 33 in the image signal group output from the imaging unit 10. To perform arithmetic processing. In addition, the interpolation unit 31 creates data within the detection range by interpolating between the detection values of the radar 60 with each calculation value corresponding to the calculation range equivalent to the detection range of the radar 60 output from the distance calculation unit 20. Then, the distance data 54 is created by combining the data within the detection range and the previous data outside the detection range.

  On the other hand, when the measured value T of the timer 34 is equal to or greater than the predetermined time Ts, the calculation range setting unit 33 sets the entire range that can be calculated by the distance calculation unit 20 as the calculation range. In this case, the performance distance calculation unit 20 performs calculation processing on all image signals in the image signal group output from the imaging unit 10. The interpolation unit 31 interpolates between the detection values of the radar 60 with each calculation value corresponding to the calculation range equivalent to the detection range of the radar 60 among the calculation values output from the distance calculation unit 20. The distance data 54 is generated by combining the data within the detection range and the data outside the detection range including the calculation value corresponding to the detection range out of the calculation data 53 output from the distance calculation unit 20. The predetermined time Ts is set based on the processing capability of the distance calculation unit 20, for example.

  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. . The storage unit 50 stores detection data 51 output from the radar 60 and distance data 53 output from the distance calculation unit 20.

  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 data 54 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 data 54 in the distance measuring apparatus 1.

  As shown in FIG. 2, first, the interpolation unit 31 starts the timer 34 (step S <b> 102). The control unit 30 instructs the radar 60 to perform a detection process for detecting the distance to the object located within the detection range (step S104), and the radar 60 performs the detection process according to the instruction of the control unit 30. The detection data 51 is output to the control unit 30.

  Next, the calculation range setting unit 33 performs calculation range setting processing for setting the calculation range in the distance calculation unit 20 (step S106). The control unit 30 instructs the imaging unit 10 to perform an imaging process (step S108), and the imaging unit 10 performs an imaging process for imaging a predetermined imaging field of view under the control of the control unit 30, and the right camera 11a. The left camera 11b outputs an image signal group. Thereafter, the control unit 30 processes the image signal group output from the imaging unit 10 and instructs the distance calculation unit 20 to calculate the distance to the object located in the imaging field of view ( Step S110). In the distance calculation unit 20, upon receiving an instruction from the control unit 30, the calculation unit 21 performs a calculation process for calculating a distance value for each image signal corresponding to the calculation range set by the calculation range setting unit 33. The distance calculation unit 20 outputs, to the control unit 30, calculation data 53 in which each calculation value and position information in the imaging field of view are associated with each other after the calculation processing on each image signal corresponding to the calculation range is completed. .

  The interpolation unit 31 interpolates between the detection values of the detection data 51 with the calculation value in the corresponding part of the calculation data 53 to create data within the detection range, and includes the detection value data and the calculation value corresponding to outside the detection range. Interpolation processing for creating distance data 54 combined with data outside the detection range is performed (step S112), and the interpolation unit 31 outputs the created distance data 54 (step S114). And the control part 30 judges whether the instruction | indication of the end of distance measurement was input (step S118), and when it is judged that the instruction | indication of the end of distance measurement is not input (step S118: No), Proceeding to step S104, distance measurement is continued. On the other hand, when it is determined that an instruction to end distance measurement has been input (step S118: Yes), the control unit 30 determines whether or not the timer 34 is measuring time (step S120). When the interpolation unit 31 determines that the timer 34 is not measuring time (step S120: No), the distance measurement is finished as it is. Further, when the control unit 30 determines that the timer 34 is measuring time (step S120: Yes), the timer 34 returns to 0 and resets it (step S122), and then the distance measurement ends. .

  Next, the calculation range setting process shown in FIG. 2 will be described. FIG. 3 is a flowchart showing a processing procedure of the calculation range setting process shown in FIG. FIG. 4 is a diagram illustrating a range in which the distance calculation unit 20 can calculate. In FIG. 4, the computable range and the detection range of the radar 60 are superimposed, and in FIG. 4, the detection points in the radar 60 are indicated by “●”.

  As illustrated in FIG. 3, the calculation range setting unit 33 determines whether or not the measured value T of the timer 34 is equal to or longer than a predetermined time Ts (step S142). If the calculation range setting unit 33 determines that the measured value T of the timer 34 is equal to or greater than the predetermined time Ts (step S142: Yes), the calculation range of the distance calculation unit 20 is the same as the detection range of the radar 60. Are set to the region Sa and the region Sb which is the region outside the detection range of the radar 60 (step S144). Specifically, as shown in FIG. 4, the calculation range setting unit 33 is capable of performing calculation processing, that is, the region Sa that is the same range as the detection range of the radar 60 and the region Sb that is the region outside the region Sa. A certain entire range is set as the calculation range. The interpolation unit 31 resets the time value of the timer 34 to 0 (step S146). As a result, the distance calculation unit 20 performs calculation processing on each image signal corresponding to the calculation range which is the region Sa and the region Sb set by the calculation range setting unit 33, and calculation data corresponding to each calculation range. 53 is output.

  On the other hand, when the calculation range setting unit 33 determines that the time value T of the timer 34 is not equal to or greater than the predetermined time Ts, that is, the time value T has not reached the predetermined time Ts (step S142: No), the distance The calculation range of the calculation unit 20 is set to an area Sa that is the same as the detection range of the radar 60 (step S148), and the calculation range setting process is terminated. As a result, the distance calculation unit 20 performs calculation processing on each image signal corresponding to the calculation range that is the region Sa set by the calculation range setting unit 33, and outputs calculation data 53 corresponding to each calculation range. To do.

  Next, the interpolation process shown in FIG. 2 will be described. FIG. 5 is a flowchart showing a processing procedure of the interpolation processing shown in FIG. As illustrated in FIG. 5, the interpolation unit 31 receives the calculation data 53 output from the distance calculation unit 20 (step S162). Next, the interpolation unit 31 determines whether or not the received calculation data 53 is a calculation result corresponding to the region Sa (step S164).

  When the interpolation unit 31 determines that the received calculation data 53 is a calculation result corresponding to the region Sa (step S164: Yes), the interpolation unit 31 extracts the detection data 51 (step S166). Thereafter, calculation data including the data outside the previous detection range is acquired from the storage unit 50, and the calculation result for the region Sb is extracted from the calculation data (step S168). The interpolation unit 31 supplements the detection data 51 with the calculation result corresponding to the region Sa output from the distance calculation unit 20 and the calculation result corresponding to the region Sb acquired from the storage unit 50 (step S170). The distance data 54 is created. Thereafter, the timer 34 starts timing (step S172), and the interpolation process is terminated.

  On the other hand, when the interpolation unit 31 determines that the received calculation data 53 is not the calculation result corresponding to the region Sa (step S164: No), that is, when it is determined that the calculation result corresponds to the region Sa and the region Sb. For this, the detection data 51 is extracted (step S174), and the detection data 51 is supplemented with calculation results corresponding to the areas Sa and Sb output from the distance calculation unit 20 (step S176), and interpolation processing is performed. finish.

  Next, the interpolation process shown in FIG. 5 will be specifically described. First, with reference to FIG. 6, an interpolation process in the case where the calculation data 53 output from the distance calculation unit 20 is a calculation result for the region Sa will be described. In FIG. 6, radar detection points by the radar 60 are indicated by “●”, and calculation points by the distance calculation unit 20 are indicated by “◯”.

  As illustrated in FIG. 6, when the interpolation unit 31 determines that the calculation data 53a output from the distance calculation unit 20 is a calculation result for the region Sa (step S164: Yes), the interpolation unit 31 detects from the storage unit 50. Data 51a is extracted (step S166), and out-of-detection range data, that is, operation data 53b corresponding to the region Sb is extracted from the operation data including the previous detection-out-range data stored in the storage unit 50 (step S166). S168). Then, the interpolating unit 31 interpolates the calculation value of the calculation data 53a between the detection values of the detection radar 51a to create data within the detection range. In this case, the distance data corresponding to the area Sa in the distance data 54a is the detection range data. Further, the interpolating unit 31 creates the distance data 54a by combining the data within the detection range and the calculation data 53a of the region Sb corresponding to the outside of the detection range, and ends the interpolation process.

  On the other hand, with reference to FIG. 7, an interpolation process in the case where the calculation data 53 output from the distance calculation unit 20 is a calculation result for the area Sa and the area Sb will be described. In FIG. 7, similarly to FIG. 6, radar detection points by the radar 60 are indicated by “●”, and calculation points by the distance calculation unit 20 are indicated by “◯”.

  As shown in FIG. 7, when the interpolation unit 31 determines that the calculation data 53c output from the distance calculation unit 20 is the calculation result for the region Sa and the region Sb (step S164: No), the detection data 51a is extracted (step S174). In this case, since the calculation data 53c output from the distance calculation unit 20 includes the calculation result corresponding to the region Sb, the interpolation unit 31 needs to extract the data outside the previous detection range from the storage unit 50. There is no. The interpolating unit 31 interpolates the calculation value of the region Sa in the calculation data 53c between the detection values of the detection data 51a to create data within the detection range. Then, the interpolating unit 31 creates the distance data 54b by combining the created data within the detection range with the calculation data of the region Sb in the calculation data 53c as data outside the detection range, and ends the interpolation processing.

  As described above, in the distance measuring apparatus 1 according to the first embodiment, the data within the detection range obtained by interpolating between the detection values of the radar 60 with the calculation value of the distance calculation unit 20, and the calculation value corresponding to outside the detection range of the radar 60. Creates and outputs distance data combining with out-of-detection range data consisting of For this reason, the distance measuring apparatus 1 according to the first embodiment can acquire highly accurate distance information in a wide range.

  In the first embodiment, the distance calculation unit 20 calculates a distance value for all image signals output from the imaging unit 10 every predetermined time Ts according to the calculation range set by the calculation range setting unit 33. In other cases, the distance value is calculated for an image signal corresponding to an area equivalent to the detection range of the radar 60 in the calculation range. That is, the distance calculation unit 20 does not always calculate the distance value for all image signals output from the imaging unit 10 in each calculation process. For this reason, in comparison with the conventional distance measurement device in which the distance calculation unit always calculates the distance value for all image signals output from the imaging unit, in the first embodiment, the number of image signals to be calculated Can be reduced. As a result, in the distance measuring device 1 according to the first embodiment, it is possible to shorten the processing time in the arithmetic processing as compared with the conventional distance measuring device, and it is possible to quickly acquire the distance information. Become.

  In addition, the distance measuring apparatus 1 according to the first embodiment outputs data within the detection range obtained by interpolating the calculation value of the distance calculation unit 20 between the detection values of the radar 60 every time the distance data 54 is created. That is, the latest distance information is always included in the area Sa shown in FIG. For this reason, as shown in FIG. 9, when measuring the inter-vehicle distance from the preceding vehicle, a region where the preceding vehicle C is highly likely to be located is set as the detection range of the radar 60, that is, the region Sa. The region where the vehicle C is highly likely to be located is the high accuracy region. As a result, in the first embodiment, the distance information to the vehicle C can be acquired almost in real time, and various safe driving support processes can be performed with good timing. On the other hand, in the first embodiment, the out-of-detection range data is generated every predetermined time Ts, and the distance data 54 is generated using the previous out-of-detection range data before the predetermined time Ts elapses. For this reason, the region Sb shown in FIG. 8 is a standard accuracy region in which the distance information is updated every predetermined time Ts. For example, as shown in FIG. 9, when measuring the inter-vehicle distance from the preceding vehicle, an area where the possibility of the preceding vehicle being low is set as an area outside the detection range of the radar 60, that is, the area Sb. In this case, an area where the possibility that the vehicle C is located is the standard accuracy area. Here, it is not necessary to acquire the distance value at a higher frequency in the region where the possibility that the vehicle C is located is lower than the region where the possibility that the vehicle C is located is high. Therefore, in this Embodiment 1, required distance information can be efficiently acquired by setting the area | region where the possibility that the vehicle C is low is set as a standard accuracy area | region.

  Therefore, the measuring apparatus 1 according to the first embodiment has high accuracy without performing calculation time and calculation pixel thinning, narrowing of the measurement distance range, calculation processing of only the edge portion, reduction in distance resolution, and the like. Thus, it is possible to quickly acquire detailed distance information, and as a result, various safety support processes based on the distance information can be accurately performed with good timing.

(Embodiment 2)
Next, a second embodiment will be described. In the first embodiment, it is assumed that the radar detection range is set in advance before the distance measurement, but in the second embodiment, the radar detection range is variable, and this detection range is unknown. The case will be described.

  FIG. 10 is a block diagram illustrating a schematic configuration of the distance measuring apparatus according to the second embodiment. As illustrated in FIG. 10, the distance measurement device 201 according to the second embodiment is similar to the distance measurement device 1 according to the first embodiment, and includes an imaging unit 10, a distance calculation unit 20, an output unit 40, and a storage. Part 50. The distance measuring device 201 can change the detection range by the control unit 230 including the interpolation unit 231 including the detection range search unit 232, the calculation range setting unit 233, and the timer 234, and the control of the control unit 230. And a radar 260.

  The control unit 230 has the same function as the control unit 30 in the first embodiment. The interpolation unit 231 has the same function as the interpolation unit 231 in the first embodiment. The detection range search unit 232 searches for the detection range of the radar 260 based on the detection data 251 output from the radar 260. The calculation range setting unit 233 has the same function as the calculation range setting unit 33 in the first embodiment, and also has a function of setting the calculation range of the distance calculation unit 20 based on the search result of the detection range search unit 232. Have. The timer 234 has a function of measuring time similarly to the timer 34 in the first embodiment.

  Next, of the processing operations performed by the distance measuring device 201, a processing procedure until the interpolation unit 231 outputs the distance data 254 will be described. FIG. 11 is a flowchart showing a processing procedure until the interpolation unit 231 outputs the distance data 254 among the processing operations performed by the distance measuring device 201.

  As shown in FIG. 11, first, the interpolation unit 231 starts the timer 234 (step S202). Next, as in the first embodiment, the control unit 230 instructs the radar 260 to perform a detection process for detecting the distance to the object located within the detection range (step S204), and the radar 260 performs the detection process. The detection data 251 is output to the control unit 230.

  The detection range search unit 232 performs detection data search processing for searching the detection range of the radar 60 (step S208), and the calculation range setting unit 233 uses the search data 252 output from the detection range search unit 232 to calculate the distance. Calculation range setting processing for setting the calculation range of the calculation unit 20 is performed (step S210). As in the first embodiment, the control unit 230 instructs the imaging unit 10 to perform an imaging process (step S212), and the imaging unit 10 performs the imaging process. Next, the control unit 230 instructs the distance calculation unit 20 to perform calculation processing (step S214), and the distance calculation unit 20 sets the calculation range setting unit 233 in the image signal group output from the imaging unit 10. An arithmetic process for calculating a distance value is performed on each image signal corresponding to the calculated range. And the interpolation part 231 performs an interpolation process by performing the process procedure similar to the process procedure shown in FIG. 5 (step S216), and outputs the distance data 254 (step S218).

  As in the first embodiment, the control unit 230 determines whether or not an instruction to end the distance measurement process is input (step S220), and determines that the end of the distance measurement process is not instructed. (Step S220: No), the process proceeds to Step S204, and the distance measurement is continued. Further, when the control unit 230 determines that the end of the distance measurement process is instructed (step S220: Yes), the interpolation unit 231 determines whether the timer 234 is measuring time as in the first embodiment. Is determined (step S222). When the interpolation unit 231 determines that the timer 234 is measuring time (step S222: Yes), the interpolation unit 231 resets the time value of the timer 234 (step S224), ends the distance measurement process, and the timer 234 If it is determined that the time is not being measured (step S222: No), the distance measurement process is terminated as it is.

  Next, the detection range search process shown in FIG. 11 will be described. FIG. 12 is a flowchart showing a processing procedure of the detection range search process shown in FIG. As shown in FIG. 12, the detection range search unit 232 first refers to the detection data 251 output from the radar 260 (step S232). In the detection data 251, a detection value obtained by detecting a distance to an object located within the detection range corresponds to position information within the detection range. Therefore, the detection range search unit 232 searches the detection range of the radar 260 based on the position information in the detection data 251 with reference to the detection data 251 (step S234), and outputs the search data 252. (Step S236).

  Next, the calculation range setting process shown in FIG. 11 will be described. FIG. 13 is a flowchart showing a processing procedure of the calculation range setting process shown in FIG. As illustrated in FIG. 13, the calculation range setting unit 233 refers to the search data 252 output from the detection range search unit 232 (step S242). Next, the calculation range setting unit 233 sets the detection range of the radar 260 in the search data 252 as the region Sa (step S244). In addition, the calculation range setting unit 233 sets a region other than the region Sa, that is, a non-detection region by the radar 260, as a region Sb in a range that can be calculated by the distance calculation unit 20 (step S246). For this reason, for example, as shown in FIG. 14, an area corresponding to the radar detection range 62 a in the computable range 24 is set as the area Sa, and a non-detection area 63 that is an area outside the detection range of the radar 260 is an area. It will be set as Sb.

  Then, the calculation range setting unit 233 determines whether or not the measured value T of the timer 234 is equal to or longer than the predetermined time Ts (step S248). When the calculation range setting unit 233 determines that the time value T of the timer 234 is equal to or greater than the predetermined time Ts (step S248: Yes), the calculation range of the distance calculation unit 20 is set to the region Sa and the region Sb, that is, the calculation. The entire possible range is set as the calculation range (step S250), and the time value of the timer 234 is returned to 0 and reset (step S252). When the calculation range setting unit 233 determines that the time value T of the timer 234 has not reached the predetermined time Ts (step S248: No), the calculation range setting unit 233 sets the calculation range of the distance calculation unit 20 to the region Sa ( Step S254).

  Thereafter, the distance calculation unit 20 performs calculation processing according to the calculation range set by the calculation range setting unit 233, and the interpolation unit 231 calculates the calculation data 253 output from the distance calculation unit 20 as in the first embodiment. And within the detection range obtained by interpolating between the detection values of the radar 260 with the calculation value of the distance calculation unit 20, and out-of-detection range data including calculation values corresponding to the detection range outside the radar 260 floor The distance data 254 combining the above is created. For this reason, the distance measuring device 201 according to the second embodiment can achieve the same effects as those of the first embodiment.

  Further, in the calculation range setting process, the calculation range setting unit 233 sets the calculation range of the distance calculation unit 20 in accordance with the detection range of the radar 260 searched by the detection range search unit 232, as shown in FIG. As described above, even when the detection range of the radar 260 changes from the radar detection range 62a to the radar detection range 62b, the calculation range can be set flexibly corresponding to the radar detection range 62b. For this reason, in the second embodiment, even when the detection range of the radar 260 changes, distance information in which the region corresponding to the detection range of the radar 260 is always a high-precision region can be output. It becomes possible to smoothly output detailed distance information with accuracy.

  In the first and second embodiments, the calculation range setting units 33 and 233 have been described as having the function of setting the calculation range of the distance calculation unit 20, but further, the calculation target in one image signal group The search range when searching for an image signal matching the image signal from the other image signal group may be set based on the detection results of the radars 60 and 260. The calculation unit 21 sequentially compares each image signal of the right image signal group located on the same straight line as an arbitrary straight line that passes through the image signal that is the calculation target of the left image signal group, and the image signal that is the calculation target. As a result, an image signal that most closely matches the image signal to be calculated is detected from the right image signal group. The calculation range setting units 33 and 233 are based on the detection data of the radars 60 and 260 in the region in the right image signal group that is collinear with an arbitrary straight line that passes through the image signal that is the calculation target of the left image signal group. The predetermined area is set as a search range for each image signal to be calculated. The distance calculation unit 20 corresponds to the search range set by the calculation range setting units 33 and 233 among the image signals of the right image signal group located on the same straight line as an arbitrary straight line that passes through the image signal to be calculated. An image signal that most closely matches the image signal to be calculated is detected from the image signals to be processed.

  Hereinafter, with reference to FIG. 16 and FIG. 17, the case where the calculation range setting units 33 and 233 set the search range will be described. In FIG. 16, the horizontal axis indicates the number of pixel columns in the pixel row where the image signal to be calculated is located, and the vertical axis indicates the detection distance of the radar detection points detected by the radars 60 and 260. FIG. 17 is a diagram illustrating the arrangement of the image signals of the right image signal group and the left image signal group output from the imaging unit 10. Hereinafter, the image signal positioned in the pixel column “2” in FIG. 16 will be described. Note that the image signal positioned in the pixel column “2” illustrated in FIG. 16 is described as the image signal 162b of the left image signal group 16b in FIG.

  First, the calculation range setting units 33 and 233 obtain a linear function passing through the radar detection point 161 and the radar detection point 165 located in the vicinity of the image signal 162b. In this case, as shown in FIG. 16, the linear function passing through the radar detection point 161 and the radar detection point 165 is a function corresponding to the straight line la. The calculation range setting units 33 and 233 obtain a region Sc formed by adding a predetermined value e above and below the straight line la around the straight line la. Next, the calculation range setting units 33 and 233 set a region Sc through which the straight line la passes as a search range for each image signal in the distance calculation unit 20.

  For example, the calculation range setting units 33 and 233 obtain the distance width Y2 on the area Sc on the pixel column “2” for the image signal 162b located in the pixel column “2”, and the calculation range setting units 33 and 233 The area corresponding to the distance width Y2 is set as a search area corresponding to the image signal 162b. For example, in this case, a region S11 on the same straight line as the image signal 162b in the right image signal group 16a shown in FIG. 17 is set as a search range corresponding to the image signal 162b. The distance calculation unit 20 detects an image signal that matches the image signal 162b from among the image signals located in the region S11, the image signal of the right image signal group 16a corresponding to the image signal 162b, the detected image signal, and The distance value is calculated based on the movement amount I. As a result, a calculation point 162 as shown in FIG. 18 is obtained. As for the image signal located between the radar detection point 165 and the radar detection point 169, as shown in FIG. 16, a straight line lb passing through the radar detection points 165 and 169 is obtained, and an area Sd passing through the straight line lb is obtained. In addition, a search range corresponding to each image signal may be set.

  In this way, for each image signal to be calculated, the search range is set based on the adjacent radar detection points, thereby reducing the number of image signals to be considered for matching and detecting matching image signals. The processing time required for the process can be shortened.

  In FIG. 16, the calculation range setting units 33 and 233 set the case where the search range is set based on the area Sc obtained by adding the predetermined value e to the straight line la, but the predetermined probability distribution shown in FIG. The search range may be set based on the region Se formed on the basis thereof.

  The calculation range setting units 33 and 233 may set a search range corresponding to the image signal to be calculated based on a radar detection point or a calculation point located in the vicinity of the image signal to be calculated. Good. For example, as shown in FIG. 20, the calculation range setting units 33 and 233 set the search range for the image signal located in the pixel row “2”, based on the adjacent radar detection point 161, the region S <b> 2. And an area corresponding to the distance width Y32 in the area S2 is set as a search range. In addition, the calculation range setting units 33 and 233 set a region S3 based on a calculation point 162c that is an adjacent calculation point for an image signal located in the pixel column “3”, and the distance of the region S3. An area corresponding to the width Y33 is set as a search range.

  In the first and second embodiments, the alignment 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 radars 60 and 260 is obtained in advance as follows. Process. For example, the distance measuring devices 1 and 201 perform imaging processing in the imaging unit 10 and detection processing in the radars 60 and 260 on an object having a known shape, and the positions of the known objects in the imaging unit 10 and the radars 60 and 260. Find the position of a known object at. Thereafter, the distance measuring devices 1 and 201 obtain the relationship between the position of the known object in the imaging unit 10 and the position of the known object in the radars 60 and 260 using the least square method, and the image is captured in the imaging unit 10. The positional relationship in the image information group and the positional relationship in the detection range of the radars 60 and 260 are matched.

  Further, in the distance measuring devices 1 and 201, even if the imaging origin of the imaging unit 10 and the detection origins of the radars 60 and 260 are misaligned, the distance from the imaging point and the detection point to the distance measuring devices 1 and 201 Can be regarded as substantially overlapping the imaging origin and the detection origin. Furthermore, 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 radars 60 and 260 are accurately matched, the imaging origin and the detection origin are detected by geometric transformation. It is also possible to correct the deviation.

  Further, in the distance measuring apparatuses 1 and 201 according to the first and second embodiments, the case where each radar detection point is located at a predetermined interval in the pixel row where each image signal is located has been described. Each radar detection point does not necessarily exist in a pixel row where each image signal is positioned. In this case, the interpolation unit 31 performs laser interpolation on the same pixel row as each image signal to be determined and corrected using a primary interpolation method or the like based on a plurality of laser detection points located in the vicinity of each image signal. A value is obtained and this interpolation value may be used.

  Further, the imaging unit 10 including the pair of imaging elements 13a and 13b corresponding to each of the pair of lenses 12a and 12b has been described as the imaging unit in the first and second embodiments. As shown in FIG. 1, the image pickup device includes a pair of light guide optical systems and an imaging element 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 image pickup region. Alternatively, the imaging unit 110 may be used (see, for example, Japanese Patent Laid-Open No. 8-171151 by the present applicant). As illustrated in FIG. 21, the imaging unit 110 converts a pair of mirrors 111a and 111b, mirrors 112a and 112b corresponding to the mirrors 111a and 111b, a lens 112c, and light collected by 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 116 including an image 116a and an image 116b as shown in FIG. Based on such images 116a and 116b, the distance calculation unit 20 can calculate the distance value corresponding to each image signal.

  In the first and second embodiments, the distance measuring devices 1 and 201 provided with a plurality of cameras have been described. However, the present invention is not limited to this, and may be applied to a distance measuring device provided with 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. 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 first and second embodiments, the distance measuring devices 1 and 201 including the radars 60 and 260 have been described. However, instead of the radars 60 and 260, semiconductor laser elements that transmit infrared light or visible light, It may be a distance measuring device including a light source such as a light emitting diode or a laser diode and a detector realized by a light receiving element such as a photosensor that receives reflected light from an object, or may be a light wave, microwave, millimeter A distance measuring device including a radar-type detector that measures a distance from a delay of a reflected wave using waves, ultrasonic waves, or the like may be used.

  Further, as the first and second embodiments, the distance measuring devices 1 and 201 mounted on the vehicle have been described as an example. May be. 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.

1 is a block diagram showing a schematic configuration of a distance measuring apparatus according to a first embodiment. It is a flowchart which shows the process sequence until the output of distance data is completed in the distance measuring device shown in FIG. It is a flowchart which shows the process sequence of the calculation range setting process shown in FIG. It is a figure explaining the calculation range setting process shown in FIG. It is a flowchart which shows the process sequence of the interpolation process shown in FIG. It is a figure explaining the interpolation process shown in FIG. It is a figure explaining the interpolation process shown in FIG. It is a figure explaining the distance data shown in FIG. It is a figure which shows an example of the image which the imaging part shown in FIG. 1 imaged. It is a block diagram which shows schematic structure of the distance measuring device concerning Embodiment 2. FIG. It is a flowchart which shows the process sequence until the output of distance data is completed in the distance measuring device shown in FIG. It is a flowchart which shows the process sequence of the detection range search process shown in FIG. It is a flowchart which shows the process sequence of the calculation range setting process shown in FIG. 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 figure explaining the other function of the calculation range setting part shown in FIG. 1 and FIG. It is a figure which illustrates the arrangement | sequence of the image signal group output from the imaging part shown in FIG. 1 and FIG. It is a figure explaining the other function of the calculation range setting part shown in FIG. 1 and FIG. It is a figure explaining the other function of the calculation range setting part shown in FIG. 1 and FIG. It is a figure explaining the other function of the calculation range setting part shown in FIG. 1 and 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

1, 201 Distance measuring device 10 110 Imaging unit 11a Right camera 11b Left camera 12a, 12b, 112c Lens 13a, 13b, 113 Imaging element 14a, 14b, 114 A / D conversion unit 15a, 15b, 115 Frame memory 16, 116, 116a, 116b Image 20 Distance calculation unit 24 Computable range 21 Calculation unit 22 Memory 30, 230 Control unit 31, 23 Interpolation unit 33, 233 Calculation range setting unit 34, 234 Timer 40 Output unit 50 Storage unit 51, 51a, 251 Detection Data 53, 53a, 53b, 253 Calculation data 54, 54a, 54b, 254 Distance data 60, 260 Radar 62, 62a, 62b Radar detection range 63 Non-detection range 16a Right image signal group 16b Left image signal group 162b Image signal 232 detection Range search part 252 Search data 111a, 111b, 112a, 112b Mirror C Vehicle

Claims (10)

Detecting means for detecting a distance to an object located within a predetermined 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;
Interpolating means for generating distance data by combining data within the detection range obtained by interpolating between the detection values of the detection means with the calculation value of the calculation means and data outside the detection range consisting of the calculation value corresponding to outside the detection range When,
A distance measuring device comprising:   2. The distance measurement according to claim 1, wherein the interpolation unit generates the distance data by using the previous out-of-detection range data until completion of acquisition of the out-of-detection range data being currently processed. apparatus.   The distance measuring apparatus according to claim 1, wherein the interpolation unit acquires the data within the detection range while the detection unit acquires the detection value. A detection range search means for searching a detection range of the detection means;
The distance measurement according to any one of claims 1 to 3, wherein the interpolation unit acquires the data within the detection range and the data outside the detection range based on a search result of the detection range search unit. apparatus. 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 means detects an image signal that matches an arbitrary image signal of the first image signal group from the second image signal group, and a movement amount of the detected image signal from the arbitrary image signal The distance measuring device according to claim 1, wherein a distance to an object located in the imaging field of view is calculated based on the distance. 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 a predetermined range,
A detection step of detecting a distance to an object located within a predetermined 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;
A distance obtained by combining the detection range data interpolated with the calculation value calculated in the calculation step between the detection values detected in the detection step and the detection range data composed of the calculation value corresponding to the outside of the detection range An interpolation step to generate data;
A distance measurement method comprising: In a distance measurement program that measures the distance to an object located within a predetermined range,
A detection procedure for detecting a distance to an object located within a predetermined detection range;
An imaging procedure for generating an image signal group corresponding to an imaging 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,
A distance obtained by combining the detection range data interpolated with the calculation value calculated in the calculation procedure between the detection values detected in the detection procedure and the detection range data including the calculation value corresponding to the detection range outside the detection range An interpolation procedure to generate data;
The distance measurement program characterized by including.

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