JP6717171B2 - Correction device for yaw rate sensor - Google Patents

Description

The present invention relates to a yaw rate sensor correction device that performs at least one of correction of an output value of a yaw rate sensor and determination of whether or not there is a drift abnormality of the output value.

The output value of the yaw rate sensor for detecting the motion state of the horizontal plane due to the turning of the vehicle may drift due to temperature and deterioration with time. Therefore, conventionally, there has been considered a correction device that corrects the drift of the output value of the yaw rate sensor and/or performs the drift abnormality determination that determines that the output value is abnormal when the drift of the output value is larger than a predetermined amount. In many cases, the above-mentioned correction (so-called zero-point correction) is executed in a vehicle stop state, which is a state in which it is assumed that the vehicle is not turning, that is, when the vehicle speed (vehicle speed) is substantially zero. It

However, when the vehicle is stopped on the turntable that is used to change the direction of the vehicle when the vehicle moves in and out, and when the vehicle is rotating together with the turntable, the deviation of the output value of the yaw rate sensor can be corrected. If done, the yaw rate sensor may not be corrected correctly. This is because the correction is performed while the actual yaw rate is generated even when the vehicle is stopped.

Therefore, in one of the conventional yaw rate sensor correction devices (hereinafter referred to as “conventional device”), the vehicle speed V is substantially zero (V≈0), and the yaw rate sensor output (yaw rate signal ψ) is the first. If the threshold value is equal to or greater than 1 threshold value ψ1 (ψ≧ψ1), it is determined that the vehicle is on the turntable, and the yaw rate sensor is not corrected (for example, refer to Patent Document 1).

JP-A-6-107208 (Fig. 5)

However, the output of the yaw rate sensor may fluctuate significantly due to disturbances such as the winded vehicle driving a stopped vehicle and the person getting on and off the vehicle. If the output of the yaw rate sensor temporarily increases due to such a disturbance, the conventional device may determine that the turntable is rotating even though the turntable is not rotating. On the contrary, when the output of the yaw rate sensor is temporarily reduced due to disturbance while the turntable is rotating, it may be determined that the turntable is not rotating and the yaw rate sensor may be corrected. As a result, it may be difficult to appropriately correct the output value of the yaw rate sensor (zero point correction) and/or appropriately determine whether or not the output value of the yaw rate sensor has a drift abnormality.

The present invention has been made to address the above problems. That is, one of the objects of the present invention is to more reliably inhibit the zero point correction and/or the zero point drift abnormality determination of the yaw rate sensor when the vehicle is placed on the turntable and is rotating together with the turntable. It is to provide a correction device for a yaw rate sensor capable of

Therefore, the correction device for a yaw rate sensor of the present invention (hereinafter, also referred to as “the present invention device”) has the correction of the output value of the yaw rate sensor (14) for detecting the yaw rate of the vehicle and the drift abnormality of the output value. At least one of the determinations as to whether or not to perform is performed.

Furthermore, the device of the present invention is commonly present in at least two images acquired at different times by the image acquisition means (12, 12A) capable of acquiring image information of at least the vehicle front area. Image processing means (step 310, step 510) for extracting a plurality of targets, and a horizontal direction in the same direction among the plurality of targets with respect to the total number of the plurality of targets extracted by the image processing means. Determination means (step 315, step 515) for determining whether or not the number of targets moving while having a directional component is equal to or greater than a predetermined ratio, and moving while having a horizontal component in the same direction. When the determination means determines that the number of target objects being operated is equal to or greater than a predetermined ratio, at least the determination of whether the output value of the yaw rate sensor is corrected and whether the output value has a drift abnormality is determined. Prohibiting means (step 320, step 520) for prohibiting one
Equipped with.

According to this, the device of the present invention determines whether or not the vehicle is placed on the turntable and is likely to rotate together with the turntable by the image acquisition means, not by the output value of the yaw rate sensor. This is performed based on at least the acquired image information in front of the vehicle. Therefore, when the vehicle is placed on the turntable and is rotating together with the turntable, it is possible to more reliably inhibit the zero point correction and/or the zero point drift abnormality determination of the yaw rate sensor than the conventional device. Become.

In the above description, in order to help understanding of the present invention, the names and/or reference numerals used in the embodiments are attached in parentheses to the configurations of the invention corresponding to the embodiments described later. However, each constituent element of the present invention is not limited to the embodiment defined by the reference numerals. Other objects, other features and attendant advantages of the present invention will be readily understood from the description of the embodiments of the present invention described with reference to the following drawings.

FIG. 1 is a schematic configuration diagram of a yaw rate sensor correction device according to a first embodiment of the present invention. FIG. 2 is a diagram for explaining the relationship between the image captured by the camera shown in FIG. 1 and the orientation of the vehicle on the turntable. FIG. 3 is a flowchart showing a “yaw rate sensor correction routine” executed by the CPU of the ECU shown in FIG. FIG. 4 is a diagram for explaining the relationship between the image captured by the camera shown in FIG. 1 and the rotation angle of the vehicle on the turntable. FIG. 5 is a flowchart showing a "yaw rate sensor correction routine" executed by the CPU of the ECU of the yaw rate sensor correction device according to the second embodiment of the present invention. FIG. 6 is a flowchart showing a “yaw rate sensor correction routine” executed by the CPU of the ECU of the yaw rate sensor correction device according to the modification of the second embodiment of the present invention.

<First Embodiment>
The yaw rate sensor correction device (hereinafter, also referred to as “first device”) according to the first embodiment of the present invention, as illustrated in FIG. 1, is a vehicle (hereinafter, also referred to as “own vehicle”). ) Applies to MV.

(Constitution)
The first device 10 includes a camera 12, a yaw rate sensor 14, a vehicle speed sensor 16, a display 18, and an electronic control device 20.

The camera 12 is arranged, for example, on the vehicle interior side of the front window and in front of the interior mirror. The camera 12 includes one CCD camera or CMOS camera. The camera 12 is a so-called monocular camera. The camera 12 can acquire image information of the vehicle front region SR (range of an angle 2θ1 about the longitudinal symmetry axis C1 of the vehicle MV). The camera 12 is also referred to as “image acquisition means”.

The yaw rate sensor 14 is arranged, for example, below the driver's seat of the vehicle MV. The yaw rate sensor 14 detects the rotational angular velocity yaw rate about the vertical axis of the vehicle MV and outputs a signal γ representing the yaw rate (hereinafter referred to as “yaw rate γ”).

The zero point of the yaw rate sensor 14 (the output voltage when the yaw rate γ is “0”) changes due to the temperature drift. Therefore, temperature drift correction (so-called zero point correction) is performed at appropriate times. The timely time is, for example, when the vehicle is considered to have no yaw rate, that is, when the vehicle speed V is substantially “0”.

The vehicle speed sensor 16 detects the traveling speed (vehicle speed) of the vehicle MV and outputs a vehicle speed signal V (hereinafter, referred to as “vehicle speed V”).

The display 18 displays an image captured by the camera 12 as appropriate, and a message from the electronic control unit 20 described later is appropriately displayed.

The electronic control unit (ECU) 20 is an electronic circuit including a well-known microcomputer, and includes a CPU, a ROM, a RAM, an interface I/F, and the like. ECU is an abbreviation for electronic control unit. The CPU implements various functions described below by executing instructions (routines) stored in a memory (ROM).

The ECU 20 is electrically connected to the camera 12, the yaw rate sensor 14, the vehicle speed sensor 16 and the like, and receives (inputs) signals from each of them. The ECU 20 is electrically connected to the display device 18 and sends signals such as a caution and a warning for displaying on the display device 18 in response to an instruction from the CPU.

(Operation)
First, an image captured by the camera 12 when the host vehicle MV is placed on the turntable and the turntable is rotating will be described with reference to FIG.

As shown in FIG. 2A, the own vehicle MV is placed on the turntable TT. In FIG. 2A, the camera 12 is located substantially on the rotation axis (center C2) of the turntable TT. The camera 12 images the area SR in front of the vehicle. An image of the area SR captured by the camera 12 is shown as an image P1 on the right side of FIG. In the image P1, a first building 31, a second building 32, a tree 33, a guardrail 34, a running vehicle (hereinafter referred to as “other vehicle”) 35, and the like are imaged.

When the turntable TT rotates counterclockwise by the angle φ from the state shown in FIG. 2A, the image of the region SR imaged by the camera 12 is shown as an image P2 on the right side of FIG. 2B. .. In the image P2, the first building 31, the second building 32, the tree 33, the guardrail 34, the other vehicle 35, and the like are imaged.

The first building 31, the second building 32, the tree 33, and the guardrail 34 imaged in the image P2 move to the right with respect to the image P1. On the other hand, the other vehicle 35 imaged in the image P2 is moving leftward with respect to the image P1.

[Camera image processing]
Next, a method (camera image processing) of tracking an object (hereinafter, also referred to as “target”) on the image by performing image recognition processing on such an image will be described.

First, the CPU of the ECU 20 extracts a plurality of partial regions called “templates” from the image P1. The “template” is a pixel group having a rectangular unit of horizontal direction: m pixels and vertical direction: n pixels as a unit, and is extracted from the image P1 so that a characteristic pattern is included in the pixel group. Each of m and n is, for example, an integer of several tens to 100.

The CPU of the ECU 20 extracts templates T1, T2, T3, T4, and T5 for the first building 31, the second building 32, the tree 33, the guardrail 34, and the other vehicle 35, respectively. In this case, the coordinates of the upper left corner of the templates T1 to T5 are (x1, y1), (x2, y2), (x3, y3), (x4, y4), (x5, y5), respectively.

In the image P2 shown in FIG. 2B, template matching is performed as follows based on the templates T1 to T5 extracted in the image P1.

Template matching finds the degree of similarity between a template and a partial area of the same size as the template. The degree of similarity is calculated by the following equation (1), for example. This similarity is called SSD (Sum of Squared Difference).
_{X-1 Y-1}
SSD = Σ Σ [I(x,y)-T(x,y)] ² (1)
^{x=0 y=0}

Here, I(x, y) is the brightness value of the image, and T(x, y) is the brightness value of the template. The smaller the similarity SSD is, the more similar the image of the partial area is to the image of the template. When the two completely match, the value of the similarity SSD is “0”.

Since the CPU of the ECU 20 detects a partial region similar to each template T1 to T5 from the image P2, a region (pixel group) having the same size as each template is selected from the image P2 and the similarity SSD is calculated. The selection of the region from the image P2 is sequentially performed by the raster scan method from the origin (upper left) of the image P2, for example. The CPU extracts the regions in which the similarity SSD with the templates T1 to T5 is the minimum as the partial regions R1 to R5, respectively. The above is the outline of the camera image processing.

Such template matching is well known, and is described in detail, for example, in Japanese Patent Laid-Open No. 2004-207393 and Japanese Patent Laid-Open No. 2011-218090. These are incorporated herein by reference.

The CPU further compares the coordinate positions of the partial regions R1 to R5 (the coordinates of the upper left corner) with the coordinate positions of the templates T1 to T5 corresponding to the partial regions R1 to R5, respectively. Then, the CPU obtains a vector (direction and size) from the coordinate position of each template to the coordinate position of the corresponding partial area.

Of these (in this case, five) vectors, if a predetermined ratio (for example, 80%) or more of the vectors are oriented horizontally and in the same direction (that is, they have horizontal components in the same direction). The CPU of the ECU 20 determines that the host vehicle MV may be placed on the turntable TT and may be rotating together with the turntable TT.

More specifically, the coordinate positions of the partial regions R1 to R5 extracted in FIG. 2B are, for example, (x1+L1, y1), (x2+L2, y2), (x3+L3, y3), (x4+L4, y4) and (x5-L5, y5) (L1 to L5 are positive values). The magnitudes of the horizontal components of the vectors from the templates T1 to T5 toward the partial regions R1 to R5 are |L1|, |L2|, |L3|, |L4|, and |L5|, respectively. Among these vectors, the vectors corresponding to |L1| to |L4| are rightward, and the vectors corresponding to |L5| are leftward. That is, the partial regions R1 to R4 have a rightward horizontal component, and the partial region R5 has a leftward horizontal component.

That is, in this example, a vector of a predetermined ratio (80%) or more among the vectors from the templates T1 to T5 to the partial regions R1 to R5 has the horizontal component in the same direction. In particular, in this example, they are oriented horizontally and in the same direction. Therefore, the CPU determines that the host vehicle MV may be placed on the turntable TT and may be rotating together with the turntable TT.

Next, the zero point correction process and the zero point drift abnormality determination process of the yaw rate sensor 14 will be briefly described below.

[Zero point correction processing of yaw rate sensor]
The CPU of the ECU 20 sets the output value (voltage value) of the yaw rate sensor 14 as a zero point output value when the vehicle MV is not turning, for example, when the vehicle MV is stopped (zero point correction). .. Therefore, for example, the CPU, when the condition that the speed (vehicle speed) of the vehicle MV is substantially “0” (the vehicle speed V is equal to or lower than the predetermined vehicle speed Vth) is satisfied, the CPU detects the yaw rate γ detected by the yaw rate sensor 14. Is set as the zero point output value. This zero point correction process is executed every predetermined time and when the above condition (the vehicle speed V is equal to or less than the predetermined vehicle speed Vth) is satisfied, and the zero point output value is updated at any time. The predetermined vehicle speed Vth is relatively close to "0".

[Yaw rate sensor zero point drift abnormality determination processing]
In the zero point correction process repeatedly executed at a predetermined time, when the value of the yaw rate γ set as the zero point output value largely deviates from the value initially set as the zero point output value (initial yaw rate γ0), the CPU It is determined that the yaw rate sensor 14 is abnormal (drift abnormality). For example, when the magnitude |γ-γ0| of the difference between the yaw rate γ and the initial yaw rate γ0 is equal to or greater than the predetermined value γth (|γ-γ0|≧γth), the CPU determines that the yaw rate sensor 14 is abnormal. Hereinafter, the predetermined value γth is also referred to as “zero point drift amount threshold value γth”.

The previous zero point output value γpre may be used instead of the initial yaw rate γ0. Further, when it is determined that the yaw rate sensor 14 is abnormal, the CPU may stop the vehicle stability control (VSC: Vehicle Stability Control) and may also display on the display 18 that the VSC is stopped. For example, VSC is started when the absolute value |(γr−γerr)−γtgt| of the difference between the target yaw rate γtgt and the value obtained by subtracting the temperature drift correction value γerr from the actual yaw rate γr exceeds the control intervention threshold Th. Therefore, if the yaw rate sensor 14 is abnormal, the VSC start condition may change, and the behavior of the vehicle MV may become unstable. Therefore, it is possible to prevent the behavior of the vehicle MV from becoming unstable by stopping the VSC.

(Specific operation)
The actual operation of the first device will be described below with reference to FIG. The CPU of the ECU 20 is adapted to execute the yaw rate sensor correction routine shown by the flowchart in FIG. 3 every time a fixed time elapses.

The CPU starts the process from step 300 at a predetermined time and proceeds to step 305 to determine whether the vehicle is stopped. As described above, the vehicle being stopped means that the vehicle speed V of the vehicle MV is substantially “0” (equal to or less than the predetermined vehicle speed Vth). When the vehicle MV is placed on the turntable TT, the vehicle is stopped. Therefore, the CPU makes a “Yes” determination at step 305 to proceed to step 310 to execute the above-mentioned “camera image processing”.

Next, the CPU proceeds to step 315 to move the target having a horizontal component in the same direction (right or left) with respect to the total number (for example, 5) of the targets extracted by the image processing. Is determined to be equal to or greater than a predetermined ratio (for example, 80%). When the number of targets moving while having horizontal components in the same direction is equal to or greater than the predetermined ratio, the CPU determines “Yes” in step 315, proceeds to step 320, and sets “ "Zero point correction" and "Zero point drift abnormality judgment" are prohibited. After that, the CPU proceeds to step 395 to end the present routine tentatively.

In this case, since "the number of targets moving while having horizontal direction components in the same direction is equal to or greater than a predetermined ratio", "the host vehicle MV is placed on the turntable TT and the turntable TT is present. It is thought that there is a possibility that they are rotating together with. If the host vehicle MV is placed on the turntable TT and is rotating together with the turntable TT, the output value of the yaw rate sensor 14 indicates the yaw rate γrot and the “zero point deviation γdev” due to the rotation of the turntable TT. It is a value that includes. Therefore, if the zero point correction is executed in this situation, the zero point correction is performed with a value different from the original “zero point shift γdev”, which causes inconvenience. Therefore, the CPU prohibits the zero point correction in step 320 as described above.

Similarly, when the host vehicle MV is mounted on the turntable TT and is rotating together with the turntable TT, the zero point shift γdev may exceed the threshold value γth of the zero point drift amount described above. Therefore, the CPU prohibits the zero point drift abnormality determination in step 320 as described above.

On the other hand, when the number of moving targets having the horizontal direction component in the same direction is not equal to or more than the predetermined ratio, the CPU makes a “No” determination at step 315 to proceed to step 325, at which the yaw rate sensor 14 detects The zero point correction is permitted and the zero point drift abnormality determination is permitted, and the routine proceeds to step 395 to end this routine once. In this case, the CPU determines that "the number of moving targets having the same horizontal component is not greater than or equal to a predetermined ratio", and thus "the own vehicle MV is placed on the turntable TT. , And it is not rotating with the turntable TT”.

When the vehicle speed V of the vehicle MV is not substantially “0”, the CPU makes a “No” determination at step 305 to directly proceed to step 320 to perform zero point correction and zero point drift abnormality determination of the yaw rate sensor 14. After prohibition, the routine proceeds to step 395 to end this routine once.

As described above, in the first device, when the vehicle MV is placed on the turntable TT and is rotating together with the turntable TT, the zero point correction and/or the zero point drift abnormality determination of the yaw rate sensor 14 is performed. Can be more reliably prohibited.

<Second Embodiment>
A yaw rate sensor correction device according to the second embodiment of the present invention (hereinafter, also referred to as “second device”) will be described. The second device differs from the first device 10 in that the camera 12 is a stereo camera. Therefore, the difference will be mainly described below.

The stereo camera can measure the distance between the vehicle MV and the target imaged by the stereo camera.

By the way, as shown in FIG. 4, assuming that the stereo camera 12A is on the rotation axis (center C2) of the turntable TT, the angular velocity ω during rotation of the turntable TT (own vehicle MV) is the same as the target and the stereo. It can be calculated from the distance D to the camera 12A (on the rotation axis C2 of the turntable TT), the apparent horizontal movement distance H of the target, and the imaging time interval ΔT of the stereo camera 12A. The apparent horizontal movement distance H is the difference between the horizontal components of the pixel coordinate positions calculated from at least two captured images with different shooting times.

The distance D between the target and the own vehicle MV (stereo camera 12A) is measured in each image picked up by the left and right imaging elements of the stereo camera 12A that are equidistant from each other with the intersection point with the longitudinal symmetry axis C1 as the middle point. It is calculated from the difference between the pixel coordinate positions in the horizontal direction of the target. This difference is hereinafter referred to as "parallax". As described above, the calculation of the distance D from the target utilizes the principle that the closer the distance D to the target is, the larger the parallax becomes. More specifically, the parallax is in inverse proportion to the distance D from the target. Therefore, the CPU can calculate the distance D to the target from the parallax.

For convenience, the template on the left side of FIG. 4A shows the template T2 and the template T4 shown in the image P1L. Further, the partial regions R2 and R4 shown in the image P2L are virtually displayed. That is, the position on the left side of FIG. 4A shows the position of the target before the turntable TT rotates and the apparent position of the target after the turntable TT rotates by φ. As shown in FIG. 4A, if the distance between the stereo camera 12A and the second building 32 is D2 and the distance between the stereo camera 12A and the guardrail 34 is D4, the distance D2 is smaller than the distance D4. Large (D2>D4). On the other hand, if the apparent horizontal movement distance of the second building 32 is represented by H2 and the apparent horizontal movement distance of the guardrail 34 is represented by H4, the apparent horizontal movement distance H2 is larger than the apparent horizontal movement distance H4 (H2 >H4).

More specifically, when the turntable TT is rotating, the ratio of the distance D between the target and the stereo camera 12A and the apparent horizontal movement distance H is constant. In other words, the ratio D2/H2 for the second building 32 and the ratio D4/H4 for the guardrail 34 are equal. That is, the apparent angular velocity ω of the second building 32 and the apparent angular velocity ω of the guardrail 34 are equal. Therefore, in this case, the CPU can determine that the host vehicle MV is placed on the turntable TT and the turntable TT is rotating. The picked-up images P1L and P2L are images picked up by the left image pickup device of the left and right image pickup devices of the stereo camera 12A. This is an example, and an image captured by the imaging element on the right side may be used as the image for calculating the angular velocity ω.

(Specific operation)
The actual operation of the second device will be described below with reference to FIG. The CPU of the ECU 20 is adapted to execute the yaw rate sensor correction routine shown by the flowchart in FIG.

The CPU starts the process from step 500 at a predetermined time and proceeds to step 505 to determine whether or not the vehicle is stopped. When the vehicle MV is stopped (that is, the vehicle speed V is substantially “0”), the CPU determines “Yes” in step 505, proceeds to step 510, and executes camera image processing. The “camera image processing” is the same as the camera image processing executed by the CPU of the ECU 20 of the first device 10.

Next, the CPU proceeds to step 515, and with respect to the total number of targets (for example, five) extracted by the image processing, the number of targets moving while having a horizontal component in the same direction is a predetermined number. It is determined whether the ratio is 80% or more (for example, 80%). If the number of moving targets having the horizontal direction component in the same direction is equal to or larger than the predetermined ratio, the CPU determines “Yes” in step 515, proceeds to step 520, and sets the yaw rate sensor 14 to zero. Prohibit point correction processing. That is, in this case, the CPU determines that “the own vehicle MV may be placed on the turntable TT and may be rotating together with the turntable TT”.

Next, the CPU proceeds to step 525, where the number of targets rotating at the same angular velocity is a predetermined ratio (eg, 80%) or more with respect to the total number of extracted targets (eg, 5). Determine whether there is. When the number of targets rotating at the same angular velocity is equal to or higher than the predetermined ratio, the CPU determines “Yes” in step 525, proceeds to step 530, and establishes the relationship shown in the following equation (2). It is determined whether it holds. In this case, since the number of targets rotating at the same angular velocity is equal to or more than a predetermined ratio, the CPU says that "the own vehicle MV is placed on the turntable TT and is rotating together with the turntable TT". judge.

|γcv-γs|>Th1 (2)

γcv: Yaw rate estimated from the captured image γs: Yaw rate detected by the yaw rate sensor

If the equation (2) is satisfied, the CPU makes a “Yes” determination at step 530 to proceed to step 535, determines that the “zero point drift abnormality” has occurred and proceeds to step 595 to end the present routine tentatively. To do. On the other hand, if the above expression (2) is not satisfied, the CPU makes a “No” determination at step 530 to directly proceed to step 595 to end the present routine tentatively.

If the CPU determines “No” in step 525, the CPU proceeds to step 540 to prohibit the zero-point drift abnormality determination and directly proceeds to step 595 to end the present routine tentatively. That is, in this case, since there is a high probability that the host vehicle MV is moving on the horizontal plane without rotating, the CPU prohibits the zero point drift abnormality determination of the yaw rate sensor 14.

Further, when the determination is “No” in step 515, the CPU proceeds to step 545 to permit the zero point correction and the zero point drift abnormality determination, and directly proceeds to step 595 to end the present routine tentatively. .. That is, in this case, "there is no possibility that the host vehicle MV is rotating on the horizontal plane (turntable TT)" and "the host vehicle MV is stopped", so the CPU determines that the yaw rate sensor 14 is at zero. It is determined that point correction and zero point drift abnormality determination are possible.

In addition, when the determination in step 505 is “No”, the CPU proceeds to step 550 to prohibit the zero point correction and the zero point drift abnormality determination, and directly proceeds to step 595 to end the present routine tentatively. To do.

As described above, in the second device, in the case where the host vehicle MV is placed on the turntable TT and is rotating together with the turntable TT, the host vehicle MV is detected from the image captured by the stereo camera 12A. If it is determined that the yaw rate sensor 14 is rotating, the zero point drift abnormality of the yaw rate sensor 14 can be determined.

<Modification of Second Embodiment>
A yaw rate sensor correction device according to a modified example of the second embodiment of the present invention (hereinafter also referred to as “second modified device”) is applied to a vehicle equipped with a variable damping force absorber. In the second modification, before the CPU of the ECU 20 executes the drift abnormality determination of the yaw rate sensor 14, the vehicle state quantity feedback control of the damping force variable absorber is stopped, and the damping force of the shock absorber is fixed to the maximum value. Different from the second device. Hereinafter, this difference will be mainly described.

The variable damping force absorber is hereinafter also referred to as an AVS (Adaptive Variable Suspension system). The AVS independently determines the damping force of the shock absorber corresponding to each wheel of the vehicle MV based on the vertical, lateral, and longitudinal accelerations of the vehicle MV detected by an acceleration sensor (not shown) provided in the vehicle. Change to, to make the body's "flapping" natural and smooth.

However, when the vehicle MV is placed on the turntable TT and is rotating together with the turntable TT and the AVS function is enabled, in order to reduce the roll, pitch, etc. that occur during rotation, The damping force of each shock absorber fluctuates. Due to this fluctuation, the output value of the yaw rate sensor 14 transiently changes.

Therefore, the second modification device stops the vehicle state quantity feedback control during AVS operation so that the own vehicle MV reduces unnecessary movement on its own spring and reduces the yaw rate fluctuation that occurs transiently. As a result, the accuracy of the yaw rate estimated from the captured image can be improved.

(Specific operation)
Hereinafter, the actual operation of the second modification device will be described with reference to FIG. The CPU of the ECU 20 is adapted to execute the yaw rate sensor correction routine shown by the flowchart in FIG. 6 every time a fixed time elapses. Note that steps 505 to 550 in FIG. 6 represent the same steps as steps 505 to 550 in FIG. 5, respectively. Hereinafter, differences from the yaw rate sensor correction routine shown in FIG. 5 will be mainly described.

When the CPU determines “Yes” in Steps 505 and 515, the CPU proceeds to Step 525 and, with respect to the total number of extracted targets (for example, 5), the number of targets rotating at the same angular velocity. Is greater than or equal to a predetermined ratio (e.g., 80%).

When the number of targets rotating at the same angular velocity is equal to or higher than the predetermined ratio, the CPU determines “Yes” in step 525 and proceeds to step 605 to determine whether the AVS is in the operating state. To do. If the AVS is in the operating state, the CPU makes a “Yes” determination at step 605 to proceed to step 610, stops the vehicle state quantity feedback control, and proceeds to step 615. On the other hand, if the AVS is not in operation, the CPU makes a “No” determination at step 605 to directly proceed to step 615. Next, in step 615, the CPU fixes the damping force of each shock absorber to the maximum value, proceeds to step 530, and determines whether or not the relationship shown in the above-mentioned equation (2) is established.

If the expression (2) is satisfied, the CPU makes a “Yes” determination at step 530 to proceed to step 535, determines that the “zero point drift abnormality” has been reached, proceeds to step 695, and ends the present routine tentatively. To do. On the other hand, if the above expression (2) is not satisfied, the CPU makes a “No” determination at step 530 to directly proceed to step 695 to end the present routine tentatively.

As described above, the output value of the yaw rate sensor 14 is fixed by fixing the damping force of each shock absorber to the maximum value when the vehicle MV is placed on the turntable TT and is rotating together with the turntable TT. It is possible to reduce the transitional fluctuation of and to improve the accuracy of determination of zero-point drift abnormality.

<Modification>
The present invention is not limited to the above embodiment, and various modifications can be adopted within the scope of the present invention as described below.

When the vehicle has a back camera for checking the rear of the vehicle, the back camera may be used as the image acquisition unit instead of the camera 12 or together with the camera 12. The back camera is provided, for example, on the trunk lid of the vehicle. The back camera is equipped with one CCD or CMOS camera.

The ECUs 20 of the first device, the second device, and the second modification device have used the vector information regarding all the extracted targets for the “determination process” in steps 315 and 515. Further, the ECU 20 uses the angular velocity information regarding all the extracted targets in the “determination process” in step 525. On the other hand, in one of the modified examples, targets that are recognized as moving objects such as vehicles (other vehicles) and pedestrians among the extracted targets are excluded from the target of the “determination process”. Good.

More specifically, the ECU 20 stores in advance the image patterns of moving bodies (vehicles, pedestrians, etc.) in the ROM, and the image patterns stored in these ROMs and the image patterns of the extracted targets. And are compared. The ECU 20 determines that a target whose image pattern is similar to the image pattern stored in the ROM among the plurality of extracted targets is a moving object, and excludes it from the target of the “determination process”. This makes it possible to exclude the vector information and/or the angular velocity information about the moving body that may be noise in the “determination process” and improve the accuracy of the determination process.

The first device, the second device, and the second modification device calculated the similarity using SSD in template matching. For example, SAD (Sum of Absolute Difference) which is the sum of absolute values of differences in luminance value and normal It may be calculated using NCC (Normalized Cross-Correlation) which is a generalized cross-correlation. Further, although the first device, the second device, and the second modification device extract the target using the template matching method, it is possible to use not only the template matching method but also various other pattern matching methods. Good.

10... Yaw rate sensor correction device, 12... Camera, 14... Yaw rate sensor, 16... Vehicle speed sensor, 18... Display (display), 20... Electronic control unit (ECU), MV... Vehicle (own vehicle).

Claims (1)

A yaw rate sensor correction device that executes at least one of correction of an output value of a yaw rate sensor that detects a yaw rate of a vehicle and determination of whether or not there is a drift abnormality of the output value,
Image acquisition means capable of acquiring image information of at least the vehicle front area,
Image processing means for extracting a plurality of targets that are commonly present in at least two images acquired at different times by the image acquisition means;
With respect to the total number of the plurality of targets extracted by the image processing unit, the number of the targets moving among the plurality of targets having the horizontal component in the same direction is equal to or more than a predetermined ratio. Determination means for determining whether or not there is,
When the determination means determines that the number of moving targets having the horizontal component in the same direction is equal to or greater than a predetermined ratio, the output value of the yaw rate sensor is corrected and Prohibiting means for prohibiting at least one of the determination of whether there is a drift abnormality,
Compensation device for yaw rate sensor.

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