JP2012215447A - Object detection device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an object detection device for a vehicle, for preventing an object such as a wall which is horizontally long relative to an advancing direction of a present vehicle and has low reflection intensity from being erroneously detected as having moved from a transverse direction to the advancing direction of the present vehicle, when detecting an object using electromagnetic waves.SOLUTION: In an object detection device for a vehicle for transmitting electromagnetic waves in an advancing direction of the own vehicle, and detecting an object with time on the basis of reflection points obtained by making the object present in the advancing direction reflect the electromagnetic waves, a point group obtained by projecting the reflection point on a two-dimensional plane is detected (S10), a centroid position of the detected point group is calculated (S10), whether or not the calculated centroid position is moving in a transverse direction relative to the advancing direction and a detection width of the transverse direction is changing is determined (S14, S16, S20, S22 and S28), and it is determined that the object is not moving in the transverse direction when the calculated centroid position is moving in the transverse direction and the detection width of the transverse direction is changing (S24).

Description

  The present invention relates to an object detection apparatus for a vehicle, and more specifically to an apparatus for determining whether an object detected using electromagnetic waves is a stationary object such as a wall that does not move laterally.

  Detecting a laterally moving object such as a pedestrian in front of the vehicle traveling direction using electromagnetic waves is often performed, and the technology described in Patent Document 1 below can be given as an example. In the prior art, it is determined whether or not the person is a pedestrian or the like by comprehensively considering the lateral movement speed, position, and size of the object.

JP 2000-251200 A

  By the way, when an object is detected using electromagnetic waves, an object such as a wall that has a low reflection intensity and is horizontally long with respect to the traveling direction of the own vehicle is shown in FIG. 4B. When a part of the object is detected due to a change in position, pitching, or a change in the separation distance to the object, and the object is erroneously detected as if the object has moved laterally with respect to the traveling direction of the vehicle. As a result, unnecessary contact avoidance control may be performed.

  However, since the technique described in Patent Document 1 uses the lateral movement speed of an object, such erroneous detection cannot be prevented.

  Accordingly, the object of the present invention is to solve the above-mentioned problems, and when detecting an object using electromagnetic waves, an object such as a wall that is weak in reflection intensity and is horizontally long with respect to the traveling direction of the own vehicle is in the traveling direction of the own vehicle. An object of the present invention is to provide a vehicle object detection device that prevents erroneous detection of movement from the lateral direction.

  In order to solve the above-mentioned object, according to claim 1, the electromagnetic wave is transmitted in the traveling direction of the host vehicle, and the object is timed based on the reflection point obtained by reflecting the electromagnetic wave on the object existing in the traveling direction. In a vehicle object detection device that detects automatically, a point group detection unit that detects a point group obtained by projecting the reflection point onto a two-dimensional plane, and a centroid position calculation that calculates a centroid position of the detected point group And a lateral movement determining means for determining whether or not the calculated center-of-gravity position moves laterally with respect to the traveling direction and whether the lateral detection width has changed. The determination means is configured to determine that the object has not moved in the lateral direction when the calculated center of gravity moves in the lateral direction and the detection width in the lateral direction changes.

  In the vehicle object detection device according to claim 2, the lateral movement determination means, when the calculated center of gravity position moves in the lateral direction, and the lateral detection width is changed, Since a part of the object in the horizontal direction is detected, it is determined that the object has not moved in the horizontal direction.

  In the vehicle object detection device according to claim 3, when the lateral movement determination unit detects that the point group reciprocates in the lateral direction, the object does not move in the lateral direction. It was comprised so that it might be judged.

  In the vehicle object detection device according to claim 4, the lateral movement determination means stores a travel location where it is determined that the object has not moved in the lateral direction, and at the time of the next travel, When the object is detected at the travel location, it is immediately determined that the object has not moved in the lateral direction.

  In the vehicle object detection device according to claim 1, a point group obtained by projecting a reflection point onto a two-dimensional plane is detected, a center of gravity position of the detected point group is calculated, and the calculated center of gravity position is calculated. As a result of determining whether or not the lateral detection width has changed, the calculated center of gravity position moves laterally and the lateral detection width When the object is detected, the object is determined not to move in the lateral direction. Therefore, when the object is detected using electromagnetic waves, the reflection intensity is weak and the object is It is possible to prevent an erroneous detection that an object such as a wall has moved from a lateral direction with respect to the traveling direction of the host vehicle, and thus it is possible to suppress unnecessary contact avoidance control and the like.

  In the vehicle object detection device according to claim 2, when the calculated center of gravity moves in the horizontal direction and the detection width in the horizontal direction changes, a part of the object in the horizontal direction is detected. Therefore, it is determined that the object does not move in the lateral direction, so that an object such as a wall that is horizontally long with respect to the traveling direction of the host vehicle is erroneously detected as moving from the lateral direction with respect to the traveling direction of the own vehicle. Can be surely prevented.

  In the vehicle object detection device according to claim 3, when the point cloud is detected so as to reciprocate in the horizontal direction, the object is determined not to move in the horizontal direction. It is possible to more reliably prevent an erroneous detection that an object such as a wall that is horizontally long with respect to the traveling direction has moved from the lateral direction with respect to the traveling direction of the host vehicle.

  In the vehicle object detection device according to claim 4, the travel location where it is determined that the object is not moving in the lateral direction is stored, and the object is detected at the travel location during the next travel. In this case, it is configured to immediately determine that the object is not moving in the lateral direction. Therefore, it is erroneously assumed that an object such as a wall that is horizontally long with respect to the traveling direction of the own vehicle has moved from the lateral direction with respect to the traveling direction of the own vehicle. Detection can be prevented quickly and easily.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram illustrating an entire vehicle object detection device according to an embodiment of the present invention. It is a flowchart which shows operation | movement of the vehicle object detection apparatus shown in FIG. 2 is an explanatory diagram explaining the processing of the flow chart. 2 is an explanatory diagram specifically showing detection of an object such as a wall that is low in reflection intensity and is transverse to the traveling direction of the host vehicle, which is premised on the processing of the flow chart of FIG.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments for implementing a vehicle object detection device according to the invention will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic view generally showing a vehicle object detection device according to an embodiment of the present invention.

  In FIG. 1, reference numeral 10 denotes a vehicle (hereinafter referred to as “own vehicle”), and a four-cylinder engine (internal combustion engine; indicated as “ENG” in FIG. 1) 12 is mounted on the front thereof. The output of the engine 12 is input to an automatic transmission (shown as “T / M” in FIG. 1) 14. The automatic transmission 14 is a stepped type with 5 forward speeds and 1 reverse speed, and the output of the engine 12 is appropriately shifted there and transmitted to the left and right front wheels 16, driving the left and right front wheels 16, and the left and right rear wheels. 20 is driven to drive the vehicle 10.

  An alarm device 22 including an audio speaker and an indicator is provided in the driver's seat of the own vehicle 10, and the driver is warned by voice and vision. A brake pedal 24 disposed on the driver's seat floor of the host vehicle 10 includes brakes (disc brakes) mounted on the left and right front wheels 16 and the rear wheels 20 via a master back 26, a master cylinder 30 and a brake hydraulic mechanism 32, respectively. ) 34.

  When the driver depresses the brake pedal 24, the depressing force is increased by the master back 26, and the master cylinder 30 generates a braking pressure by the increased depressing force, and the front wheel 16 and the rear wheel 20 via the brake hydraulic mechanism 32. The brakes 34 attached to each of these are operated to decelerate the host vehicle 10. A brake switch 36 is disposed in the vicinity of the brake pedal 24 and outputs an ON signal when the driver operates the brake pedal 24.

  The brake hydraulic mechanism 32 includes an electromagnetic solenoid valve group inserted in an oil passage connected to a reservoir, a hydraulic pump, and an electric motor (all not shown) that drives the hydraulic pump. The electromagnetic solenoid valves are connected to an ECU (Electronic Control Unit) 38 via a drive circuit (not shown), and thus the four brakes 34 are mutually connected by the ECU 38 separately from the operation of the brake pedal 24 by the driver. Configured to operate independently.

  Further, an electric motor 40 that assists steering is disposed near the front wheels to assist steering. That is, in a mechanism that converts the rotational movement of the steering wheel transmitted from the steering shaft or the like into the reciprocating movement of the rack through the pinion and steers the front wheels through the tie rod (not shown), the electric motor 40 is mounted on the rack. Is placed.

  The electric motor 40 is also connected to the ECU 38 via a drive circuit (not shown). When it is necessary to avoid an obstacle by steering, the ECU 38 operates the electric motor 40 to assist the driver in avoiding the obstacle by steering.

  A radar (laser scan radar) 42 is provided in front of the host vehicle 10. The radar 42 emits a laser beam (electromagnetic wave (carrier wave)) in the traveling direction of the host vehicle 10 and receives a reflected wave of the laser beam from an object (an obstacle such as a preceding vehicle) existing in the traveling direction. Detect objects.

  The output of the radar 42 is sent to a radar output processing ECU (electronic control unit) 44 comprising a microcomputer. In the radar output processing ECU 44, the time from when the laser light is emitted until the reflected light is received is measured, the relative distance to the object is calculated, and the relative speed to the object is obtained by differentiating the relative distance. . Further, the direction of the object is detected from the incident direction of the reflected wave, and two-dimensional information of the object is obtained.

  The output of the radar output processing ECU 44 is sent to an ECU (electronic control unit) 38. Although not shown, the ECU 38 is composed of a microcomputer including a CPU, a RAM, a ROM, an input / output circuit, and the like.

  A wheel speed sensor 46 is disposed in the vicinity of the front wheel 16 and the rear wheel 20 and outputs a pulse signal for each predetermined rotation angle of each wheel. A steering angle sensor 52 is disposed in the vicinity of the steering wheel 50 provided in the driver's seat of the host vehicle 10 and generates an output proportional to the steering angle of the steering wheel 50 input by the driver. A yaw rate sensor 54 is disposed in the vicinity of the center of gravity of the host vehicle 10 and generates an output proportional to the yaw rate (rotational angular velocity) around the vertical axis (yaw axis) of the host vehicle 10.

  A crank angle sensor 60 is disposed near the crankshaft (not shown) of the engine 12 to output a pulse signal indicating the crank angle, and an intake pipe absolute pressure sensor 62 is provided to an intake pipe (not shown). Is arranged to output a signal corresponding to the absolute pressure in the intake pipe (engine load). A throttle opening sensor 64 is disposed near a throttle valve (not shown) and outputs a signal corresponding to the throttle opening.

  The output of the sensor group described above is also sent to the ECU 38. The ECU 38 counts the outputs of the four wheel speed sensors 46, detects the vehicle speed indicating the traveling speed of the host vehicle 10 by calculating the average value, etc., and counts the output of the crank angle sensor 60 to rotate the engine. The number NE is detected.

  Further, a navigation device 70 is mounted on the host vehicle 10. The navigation device 70 includes a current position detection unit 70a, a navigation processing unit 70b, a map data storage unit 70c, an input unit 70d, and a display unit 70e.

  The current position detection unit 70a outputs a positioning signal receiving unit 70a1 that receives a positioning signal such as a GPS (Global Positioning System) signal, and a signal corresponding to the orientation of the host vehicle 10 on the horizontal plane and the inclination angle with respect to the vertical direction. A gyro sensor 70a2 is provided, and the current position of the host vehicle 10 is calculated based on the received positioning signal or the autonomous navigation based on the output of the gyro sensor 70a2 and the wheel speed sensor 46 described above.

  The map data storage unit 70c includes a storage medium such as a CD-ROM, and stores (stores) map (road) data including the width of the road on which the vehicle 10 is traveling, an intersection, a right turn lane, and the like. The input unit 70d includes a switch group and a keyboard, and the display unit 70e includes a display.

  The navigation processing unit 70b includes the current position of the host vehicle 10 obtained by the current position detection unit 70a in the map (road) data stored in the map data storage unit 70c, or the position of the host vehicle 10 input to the input unit 70d. Is displayed on the display unit 70e.

  The navigation processing unit 70b and the ECU 38 are communicably connected, and the navigation processing unit 70b outputs information specifying the position where the host vehicle 10 travels on the road map data to the ECU 38.

  FIG. 2 is a flowchart showing the operation of the apparatus shown in FIG.

  In the following, the front / rear / left / right end point positions / velocities of all objects are detected using electromagnetic waves in S10. That is, as shown in FIG. 3, an electromagnetic wave is transmitted from the radar 42 in the traveling direction of the host vehicle (vehicle) 10 over time at every time tn (t0, t1, t2), and all objects existing in the traveling direction (see FIG. 3). In the example shown, only one wall 100 is shown), and the object is detected over time based on the reflection point obtained by reflection.

  In the detection area of the radar 42, as shown in FIG. 3, the object (wall 100) is regarded as a laser reflection point. When the reflection point is projected onto a two-dimensional plane on the scanner data provided in the memory of the radar output processing ECU 44, which is composed of the traveling direction (front-rear direction) of the own vehicle 10 and the direction (left-right direction) orthogonal thereto, Since a plurality of reflection points are continuously distributed at positions close to each other, the object is detected as a set (point group) of reflection points.

  In the process of S10, the position and speed (moving speed between time tn) of the reflection points (end points) at the ends in the left-right direction and the front-rear direction are detected from the set of detected reflection points of the object. Further, the center of gravity position of the set (point group) of the detected reflection points is calculated.

  Returning to the description of the flow chart of FIG. 2, the process then proceeds to S12, and when the detected object is a horizontally long object such as the wall 100 as shown in FIG. 3, its position information (about the position detected in S10). It is determined whether there is a history of information.

  When the result is affirmative in S12, the process proceeds to S14, and the fact that there is a history means that the object is superimposed on the same position (horizontal object determination position) at time tn. to decide.

  On the other hand, when the result in S12 is negative, the program proceeds to S16, in which there is a left-right center of gravity movement, that is, the center-of-gravity position calculated in S10 moves in the left-right direction (lateral to the traveling direction of the host vehicle 10). Determine whether or not.

  When the result in S16 is negative, the program proceeds to S18, in which the object is recognized as a moving object candidate, and the lateral speed is determined from the amount of movement of the center of gravity position (calculated in S10).

  As a result, in another routine (not shown), the course of the host vehicle 10 and the course of the object are predicted to determine whether or not there is a possibility of contact. Contact avoidance support control such as braking via the brake hydraulic mechanism 32 or steering assist via the electric motor 40 is executed.

  On the other hand, when the result in S16 is affirmative, the program proceeds to S20, in which whether or not there is no back-and-forth center of gravity movement, that is, whether or not the center-of-gravity position calculated in S10 moves in the front-and-rear direction Judge whether or not.

  When the result in S20 is negative, the process proceeds to S18. When the result is affirmative, the process proceeds to S22, and the current time (for example, FIG. It is determined whether or not the object of t1) in a) exists.

  If the result in S22 is affirmative, if the object at the maximum detection width is, for example, that at t0 in FIG. 3A, it is determined that a part of the object is detected at the current time (referred to as t1 in FIG. 3). Proceed to, and determine that the object is a stationary object (such as wall 100). That is, it is determined that the object has not moved in the lateral direction.

  Next, in S26, the navigation processing unit 70b of the navigation device 70 is accessed to read out the current traveling area from the map (road) data stored in the map data storage unit 70c and store it in an appropriate memory. The travel location (determined as a stationary object such as the wall 100 where the object has not moved in the lateral direction) is stored.

  As a result, when the next object is traveled (more accurately, after the next time), the same object is detected at the same travel location in the processes of S10 and S12 during the process of the flowchart of FIG. Without processing, it is immediately determined that the object has not moved laterally.

  On the other hand, when the result in S22 is negative, the process proceeds to S28, in which the left-right center-of-gravity movement of the object is not in a fixed direction in the past N times (for example, 3 times) or the width variation is large in the past M times (for example, 3 times) Judge. In other words, it is determined whether or not the movement of the center of gravity of the object is constant and the detection width is stable.

  That is, as shown in FIG. 3 (b), the calculated center of gravity moves in the horizontal direction and the detection width in the horizontal direction changes, or the point cloud is on the right side at time t1, and on the left side at time t2. Then, it is determined whether or not it is detected so as to reciprocate in the horizontal direction.

  When the result in S28 is affirmative, in other words, when it is determined that the movement of the center of gravity of the object is not constant or the detection width is not stable, the process proceeds to S24, and the object is determined as a stationary object. That is, it is determined that the object has not moved in the lateral direction.

  Since this embodiment is configured as described above, when an object is detected using the radar 42, an object such as a wall 100 that has a low reflection intensity and is horizontally long with respect to the traveling direction of the own vehicle 16 moves in the horizontal direction ( It is possible to prevent erroneous detection of the movement from the horizontal direction.

  That is, when an object is detected using electromagnetic waves such as the radar 42, an object 100 such as a wall having a low reflection intensity and being horizontally long with respect to the traveling direction of the own vehicle is usually detected as shown in FIG. However, due to changes in the front / rear and left / right positions of the vehicle relative to the object, pitching, and changes in the separation distance to the object, as shown in FIG. There was a case of erroneous detection as if the vehicle moved from the side with respect to the traveling direction of the car.

  However, by configuring as described above, erroneous detection can be prevented. As a result, unnecessary contact avoidance control or the like can be suppressed, and a driver's unexpected warning or braking or steering assist is not automatically performed, so that driving comfort is not reduced.

  As described above, in this embodiment, an electromagnetic wave is transmitted in the traveling direction of the host vehicle 10, and the object is reflected based on a reflection point obtained by reflecting the electromagnetic wave on an object (such as the wall 100) existing in the traveling direction. In a vehicle object detection device that detects over time, a point group detection unit (ECU 38, S10) that detects a point group obtained by projecting the reflection point onto a two-dimensional plane, and a barycentric position of the detected point group The center-of-gravity position calculation means (ECU 38, S10) for calculating the lateral position, and the lateral position for determining whether the calculated center-of-gravity position moves laterally with respect to the traveling direction and whether the lateral detection width has changed. Movement determination means (ECU 38, S14, S16, S20, S22, S28), and the lateral movement determination means moves the calculated center of gravity position in the lateral direction and has a detection width in the lateral direction. Change When the object is detected, it is determined that the object is not moving in the lateral direction (ECU 38, S24). On the other hand, it is possible to prevent an erroneous detection that an object such as the horizontally long wall 100 has moved from the lateral direction with respect to the traveling direction of the host vehicle 10, thereby suppressing unnecessary contact avoidance control.

  The lateral movement determination means detects a part of the object in the lateral direction when the calculated center of gravity moves in the lateral direction and the lateral detection width changes. Therefore, it is determined that the vehicle does not move in the lateral direction (S16, S20, S22, S24), and therefore an object such as a wall 100 that is horizontally long with respect to the traveling direction of the host vehicle 10 travels the host vehicle 10. It is possible to reliably prevent erroneous detection of movement from the lateral direction with respect to the direction.

  The lateral movement determining means is configured to determine that the object has not moved in the lateral direction when the point cloud is detected to reciprocate in the lateral direction (S16, S28, S24). Therefore, it is possible to more reliably prevent an erroneous detection that an object such as a wall 100 that is horizontally long with respect to the traveling direction of the host vehicle 10 has moved from the lateral direction with respect to the traveling direction of the host vehicle.

  In addition, the lateral movement determination means stores a travel location where it is determined that the object has not moved in the lateral direction, and when the object is detected at the travel location during the next travel, Since it is configured to immediately determine that the object has not moved in the lateral direction (S24, S26), an object such as a horizontally long wall 100 with respect to the traveling direction of the host vehicle 10 is lateral to the traveling direction of the host vehicle. It is possible to quickly and easily prevent erroneous detection of movement from a direction.

  In the above description, a laser radar is disclosed as an apparatus for transmitting an electromagnetic wave, but a millimeter wave radar may be used instead of or in addition to the laser radar.

  DESCRIPTION OF SYMBOLS 10 Vehicle (own vehicle), 12 Engine (internal combustion engine), 16 Front wheel, 20 Rear wheel, 22 Alarm device, 34 Brake, 36 Brake switch, 38 ECU (electronic control unit), 40 Electric motor, 42 Laser radar, 44 Radar Output processing ECU, 46 wheel speed sensor, 50 steering wheel, 52 steering angle sensor, 54 operation switch, 60 crank angle sensor, 62 intake pipe absolute pressure sensor, 64 throttle opening sensor, 70 navigation device, 100 wall

Claims (4)

  In a vehicle object detection device for detecting an object over time based on a reflection point obtained by transmitting an electromagnetic wave in the traveling direction of the host vehicle and reflecting the electromagnetic wave on an object existing in the traveling direction, the reflection point is two-dimensionally Point cloud detection means for detecting a point cloud obtained by projecting on a plane, gravity center position calculation means for calculating the gravity center position of the detected point cloud, and the calculated gravity center position transverse to the traveling direction. And a horizontal movement determination means for determining whether or not the detection width in the horizontal direction has changed, and the horizontal movement determination means moves the calculated center of gravity position in the horizontal direction. At the same time, when the lateral detection width changes, it is determined that the object has not moved in the lateral direction.   The lateral movement determining means detects a part of the object in the lateral direction when the calculated center of gravity moves in the lateral direction and the lateral detection width changes. The vehicle object detection device according to claim 1, wherein it is determined that the vehicle has not moved in the lateral direction.   The said horizontal movement determination means determines that the said object is not moving to the said horizontal direction, when the said point cloud is detected so that it may reciprocate in the said horizontal direction. Vehicle object detection device.   The lateral movement determining means stores a travel location where it is determined that the object has not moved in the lateral direction, and when the object is detected at the travel location during the next travel, 4. The vehicle object detection device according to claim 1, wherein it is immediately determined that the vehicle has not moved in the lateral direction.

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