JP5718726B2 - Vehicle periphery monitoring device - Google Patents

Description

  The present invention relates to a vehicle periphery monitoring device that detects an object existing in front of a vehicle using a radar device mounted on the vehicle.

  Conventionally, the position (distance and azimuth) of an object existing in front of the vehicle is detected by a radar device mounted on the vehicle to determine the possibility of contact between the vehicle and the object. 2. Description of the Related Art A vehicle periphery monitoring device that performs processing (warning for a driver, automatic braking of a vehicle, etc.) is known (see, for example, Patent Document 1).

JP 2000-57495 A

  A radar device mounted on a vehicle scans a detection range in front of the vehicle for each predetermined control cycle to detect an object in front of the vehicle. In order to prevent erroneous detection of an object due to noise or the like, when the same object is detected in a predetermined number of control cycles or more, a reliability improvement process is performed in which this object is a contact determination target.

  However, the present inventors have found that the start of the contact avoidance process may be delayed when such a reliability improvement process is performed. 9 to 10 describe this case.

  As shown in FIG. 9A, when a vehicle 51 equipped with a radar device having Se as a detection range passes through an intersection with a road 70 provided with a shield 60 such as a wire mesh fence or a guardrail. When the shielding object 60 is interposed between the host vehicle 51 and the other vehicle 52, the radar apparatus may detect only the front shielding object 60 and the other vehicle 52 behind may not be detected.

  Then, as shown in FIG. 9B, when the other vehicle 52 reaches the intersection, the other vehicle 52 starts to be detected by the radar device, and after the condition for the reliability improvement processing is satisfied, The contact avoidance process is started. In this case, the host vehicle 51 and the other vehicle 52 are already close to each other. As a result, the timing at which the possibility of contact between the host vehicle 51 and the other vehicle 52 is determined is delayed, and as a result, the start of the contact avoidance process is delayed, and as shown in FIG. When the vehicle 51 stops, there is a possibility that the distance between the other vehicles 52 may be narrower than when the shielding object 60 is not provided.

  The present invention has been made in view of such a background, and provides a vehicle periphery monitoring device that suppresses a delay in the start of contact avoidance processing due to the influence of a shielding object interposed between the host vehicle and an object. With the goal.

  The present invention has been made to achieve the above object, and based on distance measurement data obtained by a radar device mounted on a vehicle, an object existing in a detection range in front of the vehicle is determined for each predetermined control cycle. When the same object approaching the vehicle is detected by the object position detection unit that detects a position and the object position detection unit in the control cycle that is equal to or greater than a predetermined number of determinations, the object is in contact with the vehicle. The present invention relates to an improvement in a vehicle periphery monitoring device including a contact determination unit that determines a possibility and a contact avoidance unit that executes a predetermined contact avoidance process when the contact determination unit determines that there is a possibility of contact.

And an image part detection unit that detects an image part of an object that exists in the detection range based on a captured image of a camera mounted on the vehicle, wherein the contact determination unit is configured by the object position detection unit. Before the position detection of the object approaching the vehicle is started, the image portion detection unit exists between the image portion of the object approaching the vehicle and the vehicle and the object based on the captured image of the camera. When the first condition that the image portion of the shielding object is detected and the position of the shielding object is detected by the object position detection unit based on the distance measurement data by the radar device is satisfied, the radar device to determine the number of the control cycles in which the same object is detected by the object position detecting unit based on distance measurement data by, the number of determinations used in the contact determination unit, first With less than when the matter is not satisfied, and judging a possibility of contact between the between the object vehicle (first invention).

  According to the first invention, the image part detection unit detects an image part of an object approaching the vehicle and a shielding object (such as a wire mesh fence, a guardrail) existing between the object and the vehicle, and the object When the first condition that the position of the shielding object is detected by the position detection unit is satisfied, it is difficult to detect the object behind the shielding object by the radar device. The image part is in a situation where it is detected by the image part detection unit.

  In this case, since the presence of the object approaching the vehicle can be detected from the image, the reliability of the detection position of the approaching object used by the contact determination unit can be ensured even if the number of determinations is reduced. . Therefore, the contact determination unit determines the possibility of contact between the vehicle and the object approaching the vehicle detected by the object position detection unit by reducing the number of determinations.

  Then, since an object that has not been detected because it is hidden behind a roadside shield starts to be detected at an intersection where the shield is interrupted, the contact determination unit may contact the object with the vehicle. The time until the determination is made can be shortened. Therefore, it can suppress that the start of the contact avoidance process by the said contact avoidance part is overdue.

  In the first invention, the contact determination unit detects the same object approaching the vehicle in a predetermined local range within the detection range in the control cycle equal to or more than the determination times by the object position detection unit. The image portion detection before the position detection of the object approaching the vehicle in the local range is started by the object position detection unit. The image portion of the object approaching the vehicle and the image portion of the shielding object existing between the vehicle and the object are detected by the unit, and the position of the shielding object is detected by the object position detection unit. When the second condition that the position of the object is detected outside the local range is satisfied, the number of times of determination is smaller than when the second condition is not satisfied, and the object and the vehicle Can contact And judging sex (second invention).

  In the second invention, an image portion of an object approaching the vehicle and an image portion of a shielding object existing between the vehicle and the object are detected by the image portion detector, and the object position detector When the second condition that the position of the shielding object is detected and the position of the object is detected outside the local range is satisfied, there is an object approaching the vehicle behind the shielding object. Can be recognized with higher accuracy.

  Therefore, in this case, by further reducing the number of determinations, it is possible to further shorten the time until the contact determination unit starts determining the possibility of contact between the object and the vehicle. Therefore, it can suppress that the start of the contact avoidance process by the said contact avoidance part is overdue.

Explanatory drawing of the attachment aspect to the vehicle of a vehicle periphery monitoring apparatus. Explanatory drawing of the scanning range of the left-right direction of a radar apparatus. Explanatory drawing of the scanning range of the up-down direction of a radar apparatus. The block diagram of a vehicle periphery monitoring apparatus. The 1st flowchart of the decision process of the detection position of the object in a vehicle periphery monitoring apparatus. The 2nd flowchart of the decision processing of the detection position of the object in a vehicle periphery monitoring apparatus. Explanatory drawing of the condition where the own vehicle and another vehicle approach in the state where the shielding object intervened between the own vehicle and the other vehicle. Explanatory drawing of the condition where a shield is interrupted and a contact determination process and a contact avoidance process are performed. Explanatory drawing of the condition where the own vehicle and another vehicle approach in the conventional contact determination process. Explanatory drawing of the condition where the own vehicle and another vehicle approach by performing the conventional contact avoidance process.

  An embodiment of a vehicle periphery monitoring device of the present invention will be described with reference to FIGS.

  Referring to FIG. 1, a vehicle periphery monitoring device 10 is mounted on a vehicle (own vehicle) 1 having an infrared camera 11 and a radar device 12 mounted on the front side. The infrared camera 11 has a characteristic that the output level increases (the luminance increases) as the temperature of the imaged object increases. Instead of the infrared camera 11, a camera whose sensitivity is adjusted to other wavelength regions such as visible light may be used.

  Further, in the real space coordinate system of the object detected by the radar device 12, the front portion of the vehicle 1 is the origin 0, the X axis is the left and right direction of the vehicle 1, the Y axis is the up and down direction of the vehicle 1, and the Z axis is the vehicle 1 It is defined as the front-rear direction.

  The radar device 12 is attached to an upper position of the infrared camera 11 on the front side of the vehicle 1. As shown in FIG. 2, the radar device 12 generates a millimeter-wave (electromagnetic wave) beam BM that spreads in a narrower width than the imaging range L1 to L2 of the infrared camera 11 when viewed from above the vehicle 1. The transmission angle of the beam BM having a constant intensity is shifted by a predetermined angle so as to be scanned in the left-right direction of the vehicle 1 and output.

  The scanning range of the beam BM in the left-right direction is set so as to include all the imaging areas L1 to L2 of the infrared camera 11 in the horizontal direction. Further, as shown in FIG. 3, the vertical direction of the beam BM is scanned by three layers A1 to A3. The vertical width of the beam BM is set so as to include the vertical visual field of the imaging range L1 to L2 of the infrared camera 11.

  The radar apparatus 12 receives this millimeter wave reflected wave, that is, the millimeter wave reflected by the object existing in front of the vehicle 1 by a receiving antenna (not shown) arranged in the vertical direction. The radar apparatus 12 detects an object present in the transmission direction of the beam BM based on a reflected wave having a predetermined intensity or more among the received reflected waves.

  Further, the radar apparatus 12 detects the distance between the object reflected from the beam BM and the vehicle 1 based on the time difference between the transmission wave and the reception wave. In addition, as a radar apparatus, you may employ | adopt the radar apparatus which uses elastic vibration waves, such as an ultrasonic wave, besides electromagnetic waves (laser light etc.), such as a millimeter wave.

  Next, referring to FIG. 4, the vehicle periphery monitoring device 10 is an electronic unit composed of a CPU, a memory, an interface circuit, etc. (not shown), and digitally outputs an analog video signal output from the infrared camera 11. The CPU has a function of converting the data into an image memory (not shown) and performing various arithmetic processes by the CPU on the front image of the vehicle 1 captured in the image memory.

  The vehicle periphery monitoring device 10 also includes distance measurement data including reflection intensity data indicating the reflection intensity of the millimeter wave reflected by the object from the radar device 12 and distance data indicating the distance between the object and the vehicle 1. Is entered. Further, the vehicle 1 includes a yaw rate sensor 13 that detects the yaw rate of the vehicle 1, a speed sensor 14 that detects the traveling speed of the vehicle 1, and a brake sensor 15 that detects an operation state of a brake pedal (not shown) of the vehicle 1. The detection signals of these sensors are input to the vehicle periphery monitoring device 10.

  In addition, the vehicle 1 includes an audio output device 16, an image output device 17, and a braking device 18, and the operation of these devices is controlled by a control signal output from the vehicle periphery monitoring device 10. As the image output device 17, a HUD (head-up display) that displays an image on the front window of the vehicle 1, a display meter that indicates the traveling state of the vehicle 1, a display device that constitutes a navigation device, and the like are employed.

  The vehicle periphery monitoring device 10 executes the vehicle periphery monitoring program stored in the memory by the CPU, thereby determining the position of the object located in front of the vehicle 1 based on the distance measurement data output from the radar device 12. The object position detection unit 21 to detect, the image portion detection unit 22 to detect the image part of the object existing in front of the vehicle 1 from the image captured by the infrared camera 11, the object detected by the object position detection unit 21 and the vehicle 1 A contact determination unit 23 that determines the possibility of contact with the vehicle, and a process (contact avoidance process) for avoiding contact with an object that is determined to be in contact with the vehicle 1 by the contact determination unit 23 It functions as the contact avoiding unit 24.

  Hereinafter, according to the flowcharts shown in FIGS. 5 and 6, processing by the object position detection unit 21, the image part detection unit 22, and the contact determination unit 23 will be described. The vehicle periphery monitoring apparatus 10 repeatedly executes the flowcharts shown in FIGS. 5 and 6 for each predetermined control cycle.

  STEP 1 is processing by the object position detection unit 21. The object position detection unit 21 detects the position (direction and distance) of an object existing in the detection range in front of the vehicle 1 from the distance measurement data received from the radar device 12. STEP 20 is a process performed by the image part detection unit 22, and STEP 1 and STEP 20 are executed in parallel.

  In STEP 20, the image part detection unit 22 determines whether each pixel of the captured image (grayscale image) of the infrared camera 11 captured in the image memory is equal to or higher than the binarization threshold. 1] A binary image is generated by performing binarization processing to classify into (white) and “0” (black).

  Then, the image portion detection unit 22 has a width of one pixel in the vertical direction (y direction) of the image, in which the group of pixels divided into “1” that constitutes the high luminance area of the binary image. The lines are classified into lines extending in the horizontal direction (x direction), and each line is converted into run-length data including coordinates and lengths (number of pixels) of the position (two-dimensional position in the image). Of the lines represented by the run-length data, labels (identifiers) are attached to each of the line groups that overlap in the vertical direction of the image, and the line group is detected as an image portion of the object.

  Thereby, an object existing in the detection range is detected. The detected objects include objects such as wire fences and guardrails installed on the side of the road in addition to objects for contact determination such as other vehicles and pedestrians.

  Moreover, the image part detection part 22 performs the process (same object determination process) which determines whether the object detected for every control cycle of the vehicle periphery monitoring apparatus 10 is the same object. The same object determination process is performed by, for example, a target object detected in each of the binarized images at times k-1 and k (k: an index representing a control cycle) by a method described in Japanese Patent Application Laid-Open No. 2001-6096. This is executed based on the shape and size of the image, the correlation of the luminance distribution in the gray scale image, and the like. When it is determined that the objects are the same, the label of the image part at time k is changed to the same label as the label of the image part at time k-1.

  The subsequent STEP 2 to STEP 7 in FIG. 6, STEP 30 in FIG. 5, STEP 40 to STEP 41, STEP 50, and STEP 60 in FIG. 6 are processing by the contact determination unit 23. The contact determination unit 23 determines whether or not the detection position by the radar device 12 has been determined in STEP 60 for all objects in which the image portion is detected by the image portion detection unit 22 in STEP 2 by the processing in STEP 3 and subsequent steps. .

  Then, when the detection positions by the radar device 12 have been determined for all the objects from which the image portion has been detected, the process branches to STEP 8 in FIG. 6 and the process of one control cycle is completed. When the detection position by the radar device 12 is fixed, the contact determination unit 23 determines the possibility of contact between the vehicle 1 and the object based on the detection position.

  Regarding the determination process of the possibility of contact between the vehicle 1 and the object, for example, as described in Japanese Patent Application Laid-Open No. 2001-6096, an entry determination in which the movement vector of the detected object is set in front of the vehicle. When it is determined that the vehicle proceeds from the region to the approach determination region (the object approaches the vehicle 1), it is determined that there is a possibility that the object (the approaching object) and the vehicle 1 are in contact with each other.

  When it is determined that there is a possibility that the object and the vehicle 1 are in contact with each other, the contact avoidance unit 24 executes a contact avoidance process. Specifically, the contact avoidance unit 24 determines whether or not the driver is operating the brake based on the detection signal of the brake sensor 15. When the brake operation is not performed, an alarm from the audio output device 16 and the image output device 17 is immediately output.

  On the other hand, when the driver is operating the brake, the contact avoiding unit 24 determines whether or not the contact is avoided by the operation of the braking device 18 according to the brake operation. When it is determined that it will be avoided, an alarm is not output so that the driver is not bothered excessively.

  Further, when it is determined that it is avoided, the contact avoidance unit 24 outputs an alarm from the audio output device 16 and the image output device 17. Furthermore, the contact avoidance unit 24 operates the braking device 18 so that contact is avoided as necessary.

  In the next STEP 3, the contact determination unit 23 uses the center layer A 2 (see FIG. 3) of the radar device 12 for the approaching object (moving object approaching the vehicle 1 from the left and right direction of the vehicle 1) from which the image portion is detected. It is determined whether or not the position can be detected. When the position can be detected in the center layer A2, the process proceeds to STEP4.

  Here, when the position can be detected in the center layer A2 of the radar apparatus 12, it can be assumed that the position of the center portion of the object 42 such as a pedestrian is detected as shown in FIG. Therefore, in STEP 4, the contact determination unit 23 counts up a counter NCNT (normal counter) indicating that the position of the detection target object (another vehicle or a pedestrian) has been reliably detected (NCNT + 1 → NCNT). Then, the process proceeds to STEP 5 in FIG.

  On the other hand, as shown in FIG. 3, when the position of the approaching object from which the image portion is detected cannot be detected in the center layer A2 of the radar apparatus 12 due to the influence of the shielding object 40 as shown in FIG. The determination unit 23 determines whether it is possible to detect the image part and the position of the shielding object between the approaching object from which the image part is detected and the host vehicle 1. The condition of STEP 30 corresponds to the first condition of the present invention.

  If the position of the image part of the shielding object can be detected, the process branches to STEP 40. If the position of the image part of the shielding object cannot be detected, the process proceeds to STEP 5 in FIG. In STEP 40, the contact determination unit 23 determines whether the position of the approaching object behind the shield can be detected by the upper layer A3 or the lower layer A1 (see FIG. 3) of the radar device 12. Note that the fact that both the conditions of STEP 30 and STEP 40 are satisfied corresponds to the second condition of the present invention.

  In STEP 40, when the position of the approaching object behind the shield can be detected by the upper layer A3 or the lower layer A1 of the radar apparatus 12, the process branches to STEP 50, and the contact determination unit 23 receives the counter PCNT (partial detection counter). ) Is counted up (PCNT + 1 → PCNT), and the process proceeds to STEP41.

  On the other hand, when the position of the approaching object behind the shielding object cannot be detected in the upper layer A3 or the lower layer A1 of the radar apparatus 12 in STEP40, the process proceeds to STEP41. In STEP 41, the contact determination unit 23 counts up the counter SCNT (shielding counter) (SCNT + 1 → SCNT), and proceeds to STEP 5 in FIG.

In STEP 5 to STEP 7 in FIG. 6, the contact determination unit 23 determines whether or not the following three conditions are satisfied, and determines the detection position of the object by the radar device 12.
(1) STEP5 ... Conditions when a shield (such as a wire fence or roadside fence) is detected The number of control cycles in which the same approaching object is detected in the central layer A2 of the radar apparatus 12 is the first determination number. (NCNT_th1) or more (NCNT_th1 ≦ NCNT).
(2) STEP6: Condition when a shielding object is detected and an image part of an approaching object is detected, but a part of the approaching object is not detected in the upper layer A3 or the lower layer A1 of the radar apparatus 12. Image part detection The number of control cycles in which the image portion of the shielding object and the approaching object is detected by the unit 22 and the position of the shielding object is detected by the object position detection unit 21 is greater than or equal to the shielding object detection threshold (SNCT_th) (SCNT_th ≦ SCNT) In addition, the number of control cycles in which an approaching object is detected in the center layer A2 of the radar apparatus 12 is equal to or greater than the second determination number (NCNT_th2, NCNT_th2 <NCNT_th1) (NCNT_th2 ≦ NCNT).
(3) STEP7: Conditions when a shielding object is detected, an image portion of the approaching object is detected, and a part of the approaching object is detected in the upper layer A3 or the lower layer A1 of the radar apparatus 12 Above the radar apparatus 12 The number of control cycles in which an approaching object is detected by the layer A3 or the lower layer A1 is partially equal to or greater than the detection threshold (PCNT_th) (PCNT_th ≦ PCNT), and the approaching object is detected by the center layer A2 of the radar apparatus 10. The number of control cycles is equal to or greater than the third determination number (NCNT_th3, NCNT_th3 <NCNT_th2) (NCNT_th3 ≦ NCNT).

  When at least one of the above conditions (1) to (3) is satisfied, the process branches to STEP 60, and the contact determination unit 23 determines the detection position of the object (approaching object) by the radar device 12. In this case, the contact determination unit 23 performs the above-described determination process of the possibility of contact between the vehicle 1 and the object based on the determined position of the object. Then, the process proceeds to STEP 8 and the process of one control cycle is completed.

  On the other hand, when none of the above conditions (1) to (3) is satisfied, the process proceeds to STEP8. In this case, the detection position of the object by the radar device 12 is not fixed.

  Next, with reference to FIGS. 7 to 8, effects obtained by executing the processing according to the flowcharts of FIGS. 5 to 6 described above will be described.

  As shown in FIG. 7A, when the vehicle (own vehicle) 1 approaches an intersection with a road 41 provided with a roadside shield (installed object such as a wire fence, guardrail, etc.) 40, The shield 40 may block millimeter waves emitted from the radar device 12 of the host vehicle 1 to the detection range Se, and the radar device 12 may not be able to detect the position of the other vehicle 30.

  In this case, the other vehicle 30 starts to be detected by the center layer A2 of the radar device 12 of the own vehicle 1, as shown in FIG. 7B, the other vehicle 30 approaches the intersection and the shield 40 is interrupted. From time. From this point of time, if the position of the object is determined on the condition that the object is detected in the central layer A2 of the radar apparatus 12 in the control cycle equal to or more than the predetermined number of determinations, the contact determination unit 23 There is a possibility that the timing at which the contact determination between the vehicle 1 and the object is performed is delayed. As a result, the start of the contact avoidance process by the contact avoiding unit 24 is delayed, and the host vehicle 1 and the other vehicle 30 may be in contact with each other.

  On the other hand, in the present embodiment, the contact determination unit 23 detects that the roadside shield 40 is an object position detection unit as shown in FIG. 7A by the processing according to the flowcharts of FIGS. 21 and the image portion detection unit 22 and when the image portion detection unit 22 detects an image portion of a part of the other vehicle 30 (such as a roof) behind the shield 40, STEP 41 in FIG. Thus, the shield counter SCNT is counted up.

  In STEP 6 of FIG. 6, when the count value of the shielding object counter SCNT is equal to or greater than the shielding object detection threshold SCNT_th and the count value of the normal counter NCNT is equal to or greater than the second determination number NCNT_th2 that is smaller than the first determination number NCNT_th1. In STEP 60, the detection position of the object by the radar device 12 is determined.

  Therefore, as shown in FIG. 7B, after the position of the other vehicle 30 starts to be detected by the center layer A2 of the radar device 12 of the host vehicle 1, the position of the other vehicle 30 is determined by the contact determination unit 23. The time until is shortened. As a result, as shown in FIG. 8A, the timing at which the contact avoidance process is started by the contact avoiding unit 24 is advanced, so that the host vehicle 1 is connected to the other vehicle 30 as shown in FIG. It is possible to stop before touching.

  Further, in the state of FIG. 7A, when the position of a part of the other vehicle 30 (such as a roof) is detected over the shield 40 by the upper layer A3 of the radar device 12 of the own vehicle 1, FIG. In STEP 50, the partial detection counter PCNT is counted up. Then, in STEP 7 of FIG. 6, the count value of the partial detection counter PCNT is equal to or greater than the partial detection threshold PCNT_th, and the count value of the normal counter NCNT is equal to or greater than the third determination count NCNT_th3, which is smaller than the second determination count NCNT_th2. Sometimes, in STEP 60, the detection position of the object by the radar device 12 is determined.

  Therefore, after the position of the other vehicle 30 starts to be detected by the center layer A2 of the radar device 12 of the own vehicle 1 in the state of FIG. 7B, the position of the other vehicle 30 is determined by the contact determination unit 23. Can be further shortened.

  In the present embodiment, the example of avoiding contact between the host vehicle 1 and the other vehicle 30 has been described, but the same applies to contact avoidance between the host vehicle 1 and another type of object such as a pedestrian. An effect can be obtained.

  Further, in this embodiment, in STEP 40 of FIG. 5, it is determined whether the approaching object behind the shielding object is detected by the upper layer A3 or the lower layer A1 of the radar apparatus 12, and the detection position of the object is determined. Although the process of changing the conditions is performed, the effect of the present invention can be obtained even when this process is not performed.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle (own vehicle), 10 ... Vehicle periphery monitoring device, 11 ... Infrared camera, 12 ... Radar device, 16 ... Audio | voice output device, 17 ... Image output device, 18 ... Braking device, 21 ... Object position detection part 22 ... Image part detection unit, 23 ... contact determination unit, 24 ... contact avoidance unit, 30 ... other vehicle, 40 ... shielding object.

Claims (2)

An object position detection unit that detects the position of an object existing in a detection range in front of the vehicle for each predetermined control cycle based on distance measurement data from a radar device mounted on the vehicle;
A contact determination unit that determines the possibility of contact between the object and the vehicle when the same object approaching the vehicle is detected by the object position detection unit in the control cycle of a predetermined number of determinations or more;
In the vehicle periphery monitoring device including a contact avoidance unit that executes a predetermined contact avoidance process when the contact determination unit determines that there is a possibility of contact,
An image portion detection unit that detects an image portion of an object existing in the detection range based on a captured image of a camera mounted on the vehicle;
The contact determination unit is configured to detect an image of an object approaching the vehicle by the image partial detection unit based on a captured image of the camera before the position detection of the object approaching the vehicle by the object position detection unit is started. And an image portion of the shielding object existing between the vehicle and the object is detected, and the position of the shielding object is detected by the object position detection unit based on distance measurement data by the radar device. Is used in the contact determination unit to determine the number of control cycles in which the same object is detected by the object position detection unit based on distance measurement data from the radar device. A vehicle periphery monitoring device, wherein the number of times of determination is made smaller than when the first condition is not satisfied, and the possibility of contact between the object and the vehicle is determined. In the vehicle periphery monitoring device according to claim 1,
The contact determination unit
When the same position approaching the vehicle is detected in the predetermined local range within the detection range in the control cycle equal to or greater than the number of determinations by the object position detection unit, the contact between the object and the vehicle Determine the possibility,
Before the position detection of the object approaching the vehicle in the local range by the object position detection unit is started, the image portion of the object approaching the vehicle by the image portion detection unit and the vehicle and the object A second condition is established in which an image portion of a shielding object existing in between is detected, the position of the shielding object is detected by the object position detection unit, and the position of the object is detected outside the local range. When this is the case, the vehicle periphery monitoring apparatus is characterized in that the number of times of determination is made smaller than when the second condition is not satisfied, and the possibility of contact between the object and the vehicle is determined.