JP2008275344A - Device for determining output of yaw rate sensor, and device for determining preceding/following vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To highly precisely calibrate the zero point of a yaw rate sensor, in spite of using an inexpensive relative angle sensor for a steering angle sensor. <P>SOLUTION: This device determines that the yaw rate sensor outputs a value offset from a reference position representing a straightly traveling state, if a variation in the lateral position of a preceding vehicle detected by a radar system is less than a third threshold, when the output of the yaw rate sensor is not smaller than a first threshold representing being in the course of traveling a corner for a predetermined period of time or more continuously, and a variation in steering angle detected by the steering angle sensor composed of the relative angle sensor is less than a second threshold, at which the vehicle's driver is determined to keep a steering angle, namely his or her own vehicle turns regularly. Consequently, it is possible to determine whether or not the output of the yaw rate sensor is normal, while using the inexpensive relative angle sensor and without using an expensive absolute angle sensor for a steering angle sensor. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an output determination device for a yaw rate sensor that determines an offset of an output of a yaw rate sensor of a vehicle, and a follow-up preceding vehicle determination device that uses the output determination device to determine a preceding vehicle that is subject to follow-up traveling control. And about.

  Since the yaw rate of the vehicle is zero when the vehicle is running straight, the output of the yaw rate sensor mounted on the vehicle must be zero. However, in the yaw rate sensor, it is unavoidable that the zero point drifts due to the influence of temperature change and the variation between individuals, and it is necessary to calibrate the zero point by some method.

Therefore, when the vehicle is stopped or traveling straight, the average value of the output of the yaw rate sensor over a relatively short predetermined time is calculated, and the zero point of the yaw rate sensor is calibrated with the average value. When the vehicle is not stopped or traveling straight, the average value of the output of the yaw rate sensor over a relatively long predetermined time is calculated, and the zero point of the yaw rate sensor is calibrated with the average value according to Patent Document 1 below. It is known.
Japanese Patent No. 3164672

  By the way, in order to calibrate the zero point of the yaw rate sensor, it is necessary to determine whether or not the vehicle is in a straight traveling state, which is determined based on the output of the steering angle sensor that detects the steering angle of the steering wheel. . Steering angle sensors include an absolute angle sensor that can detect the position of the steering wheel including the neutral position, and a relative angle sensor that can detect how many times the steering wheel has rotated to the right or left. In order to detect that the vehicle is running straight, that is, the steering wheel is in the neutral position, an expensive absolute angle sensor is required.

  Also, when determining the preceding vehicle that the subject vehicle is subject to following traveling control, the vehicle detected on the traveling locus of the subject vehicle estimated based on the yaw rate and the vehicle speed is determined as the preceding vehicle. If there is a drift, the traveling locus of the own vehicle is erroneously estimated, and the vehicle in the adjacent lane may be mistaken for the preceding vehicle.

  The present invention has been made in view of the above-mentioned circumstances, and while using an inexpensive relative angle sensor for the steering angle sensor, the zero point of the yaw rate sensor is accurately calibrated, and thereby the preceding vehicle is determined in the following traveling control. The purpose of this is to perform accurately.

  To achieve the above object, according to the first aspect of the present invention, a yaw rate sensor mounted on the host vehicle, a steering angle sensor including a relative angle sensor for detecting a steering angle, and a traveling direction of the host vehicle. An object detection means for detecting an object existing in the vehicle, a lateral position calculation means for calculating a lateral position of the detected object from the front position of the vehicle based on the output of the object detection means, and determining an offset of the output of the yaw rate And a yaw rate output determining means for detecting the steering angle sensor, wherein the yaw rate output determining means is not less than a first threshold value indicating that the output of the yaw rate sensor is continuously cornering for a predetermined time or more, and is detected by the steering angle sensor. The change in the lateral position of the object calculated by the lateral position calculating means is less than a second threshold value that is determined that the driver holds the steering angle. There If it is less than the third threshold value, said yaw rate sensor output determination device of the yaw rate sensor and judging that outputs a value that is offset from the reference position shown straight traveling state is proposed.

  According to the second aspect of the present invention, in addition to the configuration of the first aspect, the yaw rate output determining means determines that the value offset from the reference position indicating the straight traveling state is output. An output determination device for a yaw rate sensor is proposed in which an offset amount from the reference position is calculated based on the output of the yaw rate sensor.

  According to a third aspect of the present invention, there is provided a preceding vehicle determination device including the yaw rate sensor output determination device according to the first or second aspect, wherein the vehicle speed sensor detects the vehicle speed of the host vehicle. A traveling locus estimation means for estimating a traveling locus of the own vehicle based on outputs of the yaw rate sensor and the vehicle speed sensor; and the own vehicle performs tracking traveling control based on outputs of the object detection means and the traveling locus estimation means. A preceding vehicle determining device for determining a preceding vehicle as a target, wherein the preceding vehicle determining unit changes a preceding vehicle determining logic based on an output of the yaw rate output determining unit. Is proposed.

  According to the invention described in claim 4, in addition to the configuration of claim 3, the preceding vehicle determination unit sets the object existing in the recognition area including the traveling locus of the own vehicle as the object of the follow-up traveling control. A follow-up preceding vehicle determination device is proposed in which a longitudinal distance of the recognition area is shortened in accordance with an increase in the offset amount.

  According to the invention described in claim 5, in addition to the configuration of claim 3, the preceding vehicle determination unit sets the object existing in the recognition area including the traveling locus of the own vehicle as the object of the following traveling control. A follow-up preceding vehicle determination device is proposed in which the width of the recognition area is reduced in accordance with an increase in the offset amount.

  According to the invention described in claim 6, in addition to the configuration of claim 3, the preceding vehicle determination unit detects an object detected continuously for a predetermined time in a recognition area including a travel locus of the own vehicle. A follow-up preceding vehicle determination device is proposed in which the vehicle is determined to be a preceding vehicle that is subject to follow-up traveling control, and the predetermined time is lengthened in accordance with an increase in the offset amount.

  According to the invention described in claim 7, in addition to the configuration of any one of claims 1 to 6, the travel locus estimation unit corrects the output of the yaw rate sensor with the offset amount. A follow-up preceding vehicle determination device is proposed that estimates the travel locus based on a value.

  The radar device R according to the embodiment corresponds to the object detection means of the present invention.

  According to the configuration of the first aspect, the output of the yaw rate sensor is equal to or greater than the first threshold value indicating that the vehicle is cornering continuously for a predetermined time or more, and the steering angle detected by the steering angle sensor including the relative angle sensor. When the amount of change is less than a second threshold value determined that the driver holds the steering angle, that is, when it is estimated that the vehicle is making a steady turn, the object detected by the object detection means (preceding When the amount of change in the lateral position of the vehicle or roadside object is less than the third threshold value, the yaw rate sensor determines that it outputs a value offset from the reference position indicating the straight traveling state, so the steering angle sensor is expensive. Whether or not the output of the yaw rate sensor is normal can be determined using an inexpensive relative angle sensor without using an absolute angle sensor.

  According to the second aspect of the present invention, when it is determined that the output of the yaw rate sensor outputs a value offset from the reference position indicating the straight traveling state, the output of the yaw rate sensor at that time is offset from the reference position. By using the quantity, the reference position of the yaw rate sensor can be calibrated with high accuracy.

  According to the configuration of claim 3, the traveling locus of the own vehicle is estimated based on the vehicle speed and the yaw rate of the own vehicle, and the preceding vehicle whose own vehicle is subject to the follow-up traveling control on the object detected on the traveling locus; When making the determination, the logic for determining the preceding vehicle is changed depending on whether the yaw rate sensor is outputting the correct yaw rate, so that it is possible to prevent the preceding vehicle from being erroneously determined based on the yaw rate including an error.

  According to the fourth aspect of the present invention, when an object existing in the recognition area including the travel locus of the host vehicle estimated based on the vehicle speed and the yaw rate is determined as the preceding vehicle subject to the follow-up travel control, the yaw rate sensor Since the vertical distance of the recognition area is shortened according to the increase in the offset amount of the output of the vehicle, it is possible to prevent an object that deviates from the original traveling locus of the own vehicle from being erroneously determined as the preceding vehicle based on the offset yaw rate. be able to.

  According to the fifth aspect of the present invention, when an object existing in the recognition area including the travel locus of the host vehicle estimated based on the vehicle speed and the yaw rate is determined as the preceding vehicle subject to the follow-up travel control, the yaw rate sensor The width of the recognition area is narrowed according to the increase in the offset amount of the output of the vehicle, so that it is possible to prevent an object that deviates from the original traveling locus of the own vehicle from being erroneously determined as a preceding vehicle based on the offset yaw rate. it can.

  According to the sixth aspect of the present invention, an object detected continuously for a predetermined time in the recognition area including the travel locus of the host vehicle estimated based on the vehicle speed and the yaw rate is determined as the preceding vehicle subject to the follow-up travel control. In this case, the predetermined time is lengthened in accordance with an increase in the offset amount of the output of the yaw rate sensor, so that an object deviating from the original traveling locus of the own vehicle is erroneously determined as a preceding vehicle based on the offset yaw rate. Can be prevented.

  According to the seventh aspect of the present invention, since the travel locus is estimated based on the value obtained by correcting the output of the yaw rate sensor with the offset amount, the preceding vehicle can be accurately determined by estimating the correct travel locus. .

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 to 5 show a first embodiment of the present invention. FIG. 1 is a block diagram of a follow-up preceding vehicle determination device provided with an output determination device for a yaw rate sensor, and FIG. 2 is a flowchart for explaining the operation. FIG. 3 is a time chart showing changes in yaw rate, steering angle, and lateral position of the preceding vehicle, FIG. 4 is an explanatory diagram of an action during traveling in a corner, and FIG. 5 is an explanatory diagram of a recognition area correction method based on an offset amount.

  As shown in FIG. 1, a radar device (object detection means) R detects a preceding vehicle that the host vehicle should follow, and performs vehicle distance control on the preceding vehicle. An electronic control unit U used for vehicle control that stops and starts following the stop / start is a travel locus estimation means M1, a preceding vehicle determination means M2, a lateral position calculation means M3, and a yaw rate output determination means. M4. A vehicle speed sensor Sa and a yaw rate sensor Sb are connected to the travel locus estimating means M1, a travel locus estimating means M1 and a radar device R are connected to the preceding vehicle determining means M2, and a preceding vehicle determining means M2 is connected to the lateral position calculating means M3. Further, the radar device R is connected to the yaw rate output determining means M4, and the lateral position calculating means M3, the yaw rate sensor Sb, and the steering angle sensor Sc are connected.

  The yaw rate sensor Sb should be adjusted so that the output becomes 0 when the vehicle is traveling straight (yaw rate = 0). However, the drift caused by the influence of temperature change or individual performance fluctuations. As a result, the output may not become zero even when the vehicle is traveling straight. When the steering wheel is in the neutral position, the vehicle is estimated to be in a straight traveling state. Therefore, by setting the output of the yaw rate sensor Sb when the steering angle of the steering wheel is 0, the output of the yaw rate sensor Sb is set. Can be compensated for.

  However, the steering angle sensor includes an absolute angle sensor that detects the absolute angle of the steering angle (for example, the rotation angle of the steering wheel with reference to the neutral position), and the relative angle of the steering angle (the rotation angle of the steering wheel in the left-right direction). ) To detect the drift of the output of the yaw rate sensor Sb by the above-described method, there is a problem that an expensive absolute angle sensor is required. Therefore, in this embodiment, the drift of the output of the yaw rate sensor Sb is compensated by using the steering angle sensor Sc made of an inexpensive relative angle sensor.

  The travel locus estimation means M1 estimates the future travel locus of the host vehicle based on the vehicle speed detected by the vehicle speed sensor Sa and the yaw rate detected by the yaw rate sensor Sb. That is, since the turning radius of the own vehicle can be calculated based on the yaw rate and the vehicle speed, an arc having the turning radius becomes the estimated traveling locus of the own vehicle.

  In the preceding vehicle determination means M2, a belt-like recognition area having a predetermined width (for example, a width corresponding to the lane width) on the estimated travel locus and a predetermined distance (for example, 100 m) forward from the own vehicle is set. Of the preceding vehicles detected by the radar device R in this recognition area, the preceding vehicle closest to the host vehicle is determined as the preceding vehicle subject to the follow-up travel control.

  The lateral position calculation means M3 calculates the lateral position (shift in the left-right direction) of the preceding vehicle that is subject to follow-up travel control with respect to the direction of the vehicle body centerline of the host vehicle. In general, since the radar device R is mounted on the vehicle so as to be directed in the direction of the vehicle body centerline, the lateral position of the preceding vehicle to be subjected to the follow-up traveling control is determined in the left-right direction of the preceding vehicle detected by the radar device R. It is also a position.

  The yaw rate output determining means M4 is based on the yaw rate detected by the yaw rate sensor Sb, the steering angle detected by the steering angle sensor, and the lateral position of the preceding vehicle that is the target of the follow-up running control detected by the lateral position calculating means M3. The offset amount of the yaw rate sensor Sb (the yaw rate output when the actual yaw rate is 0) is calculated.

  Hereinafter, the function of the yaw rate output determination means M4 will be described based on the flowchart of FIG.

  First, the yaw rate data output from the yaw rate sensor Sb is retained for a predetermined time in step S1, the steering angle data output from the steering angle sensor Sc is retained for a predetermined time in step S2, and the data output from the radar device R is retained in step S3. Hold for a predetermined time.

  In the following step S4, the fluctuation of the yaw rate for a predetermined time is less than the predetermined value, in step S5, the average value of the yaw rate for the predetermined time is not less than the predetermined value (first threshold), and in step S6, the fluctuation of the steering angle for the predetermined time is changed. If it is less than the predetermined value (second threshold value) and the approach of the preceding vehicle subject to the follow-up running control is detected by the radar device R in step S7, the data of the preceding vehicle subject to the follow-up running control is obtained in step S8. Attention is paid and it is determined that there is an offset in the output of the yaw rate sensor Sb when the lateral position fluctuation of the data of the preceding vehicle of interest for a predetermined time is less than a predetermined value (third threshold value) in step S9.

  The contents of steps S8 and S9 will be described with reference to FIGS.

  As shown in FIG. 3A, when the yaw rate output from the yaw rate sensor Sb is held substantially non-zero, and the steering angle (relative steering angle) output from the steering angle sensor Sc is held substantially constant. (See steps S4 to S6). This state corresponds to a case where the host vehicle is traveling along an arc corner as shown in FIG. At this time, it is assumed that the inter-vehicle distance of the own vehicle with respect to the preceding vehicle is reduced from the state of FIG. 4A to the state of FIG. 4B (see step S7). Assuming that the lateral position of the preceding vehicle when the inter-vehicle distance shown in FIG. 4 (A) is large is X1, the lateral position of the preceding vehicle when the inter-vehicle distance shown in FIG. 4 (B) is small is X2 smaller than X1. It should decrease (see the dashed line in FIG. 3B). Therefore, in this case, it can be determined that the yaw rate sensor Sb is outputting the correct yaw rate (the output offset amount is 0).

  On the other hand, as shown by a two-dot chain line in FIG. 3 (B), when the lateral position of the preceding vehicle does not change even when the own vehicle approaches the preceding vehicle, the road on which the own vehicle and the preceding vehicle are traveling is This means that it is not a corner road but a straight road. In this case, if the vehicle is traveling straight and the output of the yaw rate sensor Sb should be 0, but the yaw rate indicated by the solid line in FIG. 3A is output, the yaw rate will be the offset amount of the yaw rate sensor Sb. It can be judged that it is equivalent.

  Returning to FIG. 1, if the yaw rate output determination means M4 determines that there is a drift in the output of the yaw rate sensor Sb as described above, the yaw rate indicated by the solid line in FIG. Perform correction. The offset amount output by the yaw rate output determining means M4 is input to the traveling locus estimating means M1, and the traveling locus estimating means M1 can estimate the correct traveling locus based on the correct yaw rate calibrated to compensate for the offset amount. (See FIG. 5A). Thereby, the possibility of misidentifying the vehicle in the adjacent lane as the preceding vehicle of the own vehicle can be reduced.

  Alternatively, the offset amount output by the yaw rate output determination means M4 is input to the preceding vehicle determination means M2, and the preceding vehicle determination means M2 normally determines the distance from the host vehicle to the front end of the recognition area that is 100 meters ahead of the vehicle. The length is shortened accordingly (see FIG. 5B). Further, instead of shortening the distance to the front edge of the recognition area according to the magnitude of the offset amount, the width of the recognition area is tapered so as to become narrower toward the front side according to the magnitude of the offset amount (FIG. 5C )reference). In this way, by adopting one or both of the two methods for changing the shape and size of the recognition area, even if there is a drift in the output of the yaw rate sensor Sb, the vehicle in the adjacent lane is It is possible to reduce the possibility of being mistaken for the preceding vehicle.

  FIGS. 6 to 8 show a second embodiment of the present invention. FIG. 6 is a flowchart for explaining the operation. FIG. 7 is a time chart showing changes in yaw rate, steering angle and lateral position of the preceding vehicle. 8 is an explanatory diagram of an action during traveling in a corner.

  In the first embodiment, the drift of the output of the yaw rate sensor Sb is determined based on the lateral position of the preceding vehicle with respect to the host vehicle. However, in the second embodiment, an object (roadside object) fixed to the roadside is used. Based on this, the output drift of the yaw rate sensor Sb is determined.

  As is clear when comparing the flowchart of FIG. 6 of the second embodiment with the flowchart of FIG. 2 of the first embodiment, steps S1 to S6 and step S10 are common, and the first embodiment Steps S8 and S9 of the form are changed to Steps S8 ′ and S9 ′ of the second embodiment, and Step S7 of the first embodiment is deleted.

  In step S8 ′, attention is paid to the roadside object detected by the radar device R instead of the preceding vehicle. In step S9 ′, when the lateral position variation of the data of the roadside object of interest for a predetermined time is less than a predetermined value (third threshold value), It is determined that there is an offset in the output of the yaw rate sensor Sb.

  This will be described with reference to FIGS.

  As shown in FIG. 7A, when the yaw rate output from the yaw rate sensor Sb is held substantially non-zero, and the steering angle (relative steering angle) output from the steering angle sensor Sc is held substantially constant. (See steps S4 to S6). This state corresponds to the case where the host vehicle is traveling along an arc corner as shown in FIG. At this time, if the host vehicle is turning right, the roadside object that was originally on the right side of the host vehicle gradually moves to the left side, and further passes to the left side through the front of the host vehicle (FIG. 7 ( B). Therefore, in this case, it can be determined that the yaw rate sensor Sb is outputting the correct yaw rate (the output offset amount is 0).

  On the other hand, as shown by a two-dot chain line in FIG. 7B, if the lateral position of the roadside object does not change even when the vehicle travels, the road on which the vehicle is traveling is not a corner road but a straight road. It means that. In this case, if the vehicle is traveling straight and the output of the yaw rate sensor Sb should be 0, but if a yaw rate of a predetermined magnitude indicated by a solid line in FIG. 7A is output, the yaw rate is detected by the yaw rate sensor. It can be determined that this corresponds to the offset amount of Sb.

  Also in the second embodiment, as in the first embodiment, the offset amount of the yaw rate sensor Sb is input to the travel locus estimation means M1 and the preceding vehicle determination means M2, and the recognition area size and shape are changed. Thus, it is possible to accurately determine the preceding vehicle that is subject to the follow-up traveling control.

  As mentioned above, although embodiment of this invention was explained in full detail, this invention can perform a various design change in the range which does not deviate from the summary.

  For example, when the yaw rate output determination means M4 determines the drift of the yaw rate sensor Sb, the preceding vehicle determination means M2 determines the predetermined time in steps S4 to S10 and step S10 in the flowcharts of FIGS. You may extend according to. By doing so, it is possible to prevent an object that deviates from the original traveling locus of the own vehicle from being erroneously determined as a preceding vehicle based on the offset yaw rate.

1 is a block diagram of a tracking preceding vehicle determination device including an output determination device for a yaw rate sensor according to a first embodiment. Flow chart explaining operation Time chart showing changes in yaw rate, steering angle and lateral position of the preceding vehicle Action explanation diagram while driving in the corner Illustration of correction method for recognition area based on offset amount Flowchart for explaining the operation of the second embodiment Time chart showing changes in yaw rate, steering angle and lateral position of the preceding vehicle Action explanation diagram while driving in the corner

Explanation of symbols

M1 Traveling track estimation means M2 Preceding vehicle determination means M3 Transverse position calculation means M4 Yaw rate output determination means R Radar device (object detection means)
Sa Vehicle speed sensor Sb Yaw rate sensor Sc Steering angle sensor

Claims (7)

A yaw rate sensor (Sb) mounted on the vehicle;
A steering angle sensor (Sc) comprising a relative angle sensor for detecting a steering angle;
Object detection means (R) for detecting an object present in the traveling direction of the host vehicle;
Lateral position calculating means (M3) for calculating the lateral position of the detected object from the front position of the vehicle based on the output of the object detecting means (R);
A yaw rate output determining means (M4) for determining an offset of the output of the yaw rate;
With
The yaw rate output determining means (M4) is at least a first threshold value indicating that the output of the yaw rate sensor (Sb) continues cornering for a predetermined time or more and is detected by the steering angle sensor (Sc). The amount of change in the steering angle is less than a second threshold value at which it is determined that the driver holds the steering angle, and the amount of change in the lateral position of the object calculated by the lateral position calculation means (M3) is the first. An output determination device for a yaw rate sensor, wherein when it is less than three threshold values, it is determined that the yaw rate sensor (Sb) outputs a value offset from a reference position indicating a straight traveling state. The yaw rate output determining means (M4)
The offset amount from the reference position is calculated based on the output of the yaw rate sensor (Sb) when it is determined that a value offset from the reference position indicating the straight traveling state is output. The output determination device for a yaw rate sensor according to Item 1. A follow-up preceding vehicle determination device comprising the output determination device for a yaw rate sensor according to claim 1 or 2,
A vehicle speed sensor (Sa) for detecting the speed of the host vehicle;
Traveling locus estimation means (M1) for estimating the traveling locus of the host vehicle based on the outputs of the yaw rate sensor (Sb) and the vehicle speed sensor (Sa);
Preceding vehicle determination means (M2) for determining the preceding vehicle that the subject vehicle is subject to following traveling control based on the outputs of the object detection means (R) and the travel locus estimation means (M1);
With
The preceding preceding vehicle determining device (M2) changes the preceding vehicle determining logic based on the output of the yaw rate output determining means (M4).   The preceding vehicle determination means (M2) determines that an object existing in a recognition area including a travel locus of the host vehicle is a preceding vehicle that is subject to follow-up travel control, and the recognition area according to an increase in the offset amount. The preceding preceding vehicle determination device according to claim 3, wherein a longitudinal distance of the vehicle is shortened.   The preceding vehicle determination means (M2) determines that an object existing in a recognition area including a travel locus of the host vehicle is a preceding vehicle that is subject to follow-up travel control, and the recognition area according to an increase in the offset amount. The following vehicle determination device according to claim 3, wherein the following vehicle is narrowed.   The preceding vehicle determination means (M2) determines an object detected continuously for a predetermined time within a recognition area including a traveling locus of the own vehicle as a preceding vehicle to be subjected to follow-up traveling control, and increases the offset amount. The preceding preceding vehicle determination device according to claim 3, wherein the predetermined time is lengthened according to the vehicle speed.   The travel trajectory estimating means (M1) estimates the travel trajectory based on a value obtained by correcting the output of the yaw rate sensor (Sb) with the offset amount. The preceding preceding vehicle determination device according to any one of the preceding claims.

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