JP2005181254A - Angular velocity detector for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely prevent a detected value from being calibrated erroneously, and to sufficiently secure a chance for the calibration, in an angular velocity detector for detecting an angular velocity concerned in a behavior of a vehicular body such as a yaw rate. <P>SOLUTION: In this detector, a zero point of the detected yaw rate Yr is calibrated in principle under a stopped condition sequentially by updating a zero point correction amount Yrcalib, and the updating of the zero point correction amount Yrcalib (i.e. calibration of the zero point in the detected yaw rate Yr) is prohibited, determining that a vehicle is under stop on a turn table while the vehicle is kept under IG:ON in a time when an absolute value of a changing speed DYr of the detected yaw rate changes from a prescribed threshold value DYrth or more of value to the threshold value DYrth or less of value in the second time (time t1-t4 in Fig.), when the vehicle travels as a circumstance after the IG:ON and when the vehicle is kept under the stop condition, with the proviso that the absolute value of a changing speed DYr of the detected yaw rate comes first to the prescribed threshold value DYrth or more of value, and that the turn table is under rotation. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an angular velocity detection device that detects an angular velocity related to the behavior of a vehicle body such as a yaw rate, a pitch rate, and a roll rate.

  Conventionally, in general, the yaw rate generated in the vehicle body of the vehicle can be detected by a yaw rate sensor using a rate gyro. In such a yaw rate sensor, a so-called drift may occur due to temperature characteristics and the like, and as a result, a detected yaw rate value (hereinafter referred to as “detected yaw rate”) (specifically, for example, zero An error occurs at point).

  Therefore, when using such a yaw rate sensor, it is necessary to calibrate the detected yaw rate (its zero point) at a predetermined frequency. Here, as a case where the actual yaw rate value acting on the vehicle body becomes zero, for example, a case where the vehicle is in a stopped state, a case where the vehicle is traveling straight, and the like can be considered. Therefore, the calibration of the detected yaw rate value is performed by, for example, obtaining a zero point correction amount for making the detected yaw rate value zero when the vehicle is in a stopped state, and calculating the zero point correction amount from the detected yaw rate. Can be achieved by reducing.

  Incidentally, in recent years, in multi-story parking lots and the like, a turntable is often installed because it is necessary to change the direction of the vehicle in a narrow space. When this turntable rotates, a yaw rate equal to the value of the rotation speed of the turntable is generated in the vehicle stopped on the turntable. Therefore, when calibration of the detected yaw rate is executed in such a case, an error is included in the value of the yaw rate after calibration (hereinafter referred to as “yaw rate after calibration”) by the rotation speed of the turntable. There is a problem that occurs.

In order to deal with such a problem, for example, the yaw rate detection device (the yaw rate sensor calibration method) described in Patent Document 1 below has an output value of the yaw rate sensor (that is, the detected yaw rate) itself when the vehicle is stopped. The calibration of the detected yaw rate is stopped (prohibited) when it is above a predetermined value. According to this, when a large yaw rate that cannot normally occur when the vehicle is in a stopped state is detected, the vehicle is rotating in the yaw direction by the rotation of the turntable on the turntable. At the discretion, the calibration can be aborted, which can prevent erroneous calibration from being performed.
Japanese Patent Laid-Open No. 11-94874

Further, for example, the yaw rate detection device (planar behavior detection device) described in Patent Document 2 described below always prohibits the calibration of the detected yaw rate when the vehicle is in a stopped state. According to this, when the vehicle stopped on the turntable is rotating in the yaw direction due to the rotation of the turntable, the calibration can be surely prohibited, and as a result, incorrect calibration can be performed. It can be reliably prevented.
JP-A-6-87460

  However, in the apparatus described in Patent Document 1, when the rotation speed of the turntable is slow and smaller than the predetermined value, the vehicle is rotating on the turntable by the rotation of the turntable. The value of the detected yaw rate does not exceed the predetermined value, and as a result, there arises a problem that the erroneous calibration may be executed.

  Further, in the apparatus described in Patent Document 2, when the vehicle is stopped and the calibration of the detected yaw rate can be executed accurately (that is, when the actual yaw rate value acting on the vehicle body is zero). Even so, calibration of the detected yaw rate is prohibited, and as a result, there is a problem that the accuracy of the calibration is reduced due to a decrease in the calibration opportunity.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to perform erroneous calibration of detected values in an angular velocity detection device for a vehicle that detects angular velocity related to the behavior of the vehicle body such as yaw rate. An object of the present invention is to provide a device that can surely prevent the occurrence of such a problem and can sufficiently secure an opportunity for calibration.

  A feature of the present invention is that vehicle speed acquisition means for acquiring a vehicle body speed of the vehicle, angular speed detection means for detecting an angular speed related to the behavior of the vehicle body of the vehicle as a detected angular speed, and the vehicle based on the acquired vehicle speed. In order to set the detected angular velocity detected by the angular velocity detecting means to zero when it is determined that at least the vehicle is in the stopped state, and at least when the vehicle is determined to be stopped. An angular velocity detection device for a vehicle comprising a detection angular velocity calibration means for obtaining a zero point correction amount and calibrating a value of the detected angular velocity based on the zero point correction amount from a state in which the vehicle is traveling The detected angular velocity calibration means when it is maintained in the stopped state after shifting to the stopped state, and the change rate of the detected angular velocity is equal to or greater than a predetermined prohibition change rate threshold value In that it comprises a calibration prohibiting means for prohibiting the calibration with.

  Here, the angular velocity related to the behavior of the vehicle body is, for example, yaw rate, pitch rate, roll rate, or the like. For example, the stop state determination unit determines that the vehicle is in a stop state when the acquired vehicle body speed is equal to or less than a predetermined value (for example, zero). The detected angular velocity calibration means obtains the zero point correction amount every predetermined calculation cycle, for example, and subtracts the zero point correction amount from the detected angular velocity to execute the calibration of the detected angular velocity every calculation cycle. (Ie, calculate post-calibration angular velocity). Further, when the calibration prohibition unit prohibits the calibration, for example, the calibration prohibition unit is configured to continue the prohibition of the calibration until the cancellation of the prohibition of the calibration is performed by the calibration prohibition canceling unit described later.

  According to this, when it is determined that at least the vehicle is in a stopped state, in principle, calibration of the detected angular velocity can be performed. Therefore, an opportunity for calibration of the detected angular velocity can be ensured even when the vehicle is stopped, and as a result, it is possible to prevent a decrease in the accuracy of the calibration.

  In general, in the process in which the turntable starts rotating and its rotational speed increases from zero to a predetermined target rotational speed, the change (increase) speed of the rotational speed is equal to the predetermined target rotational speed. Regardless of size, it tends to appear as a relatively large value. Therefore, when the turntable starts rotating while the vehicle is stopped on the turntable, even if the target rotational speed of the turntable is relatively slow (small), the detected yaw rate The rate of change appears as a relatively large value.

  Therefore, as described above, when the state of the vehicle is maintained from the traveling state to the stopped state and maintained in the stopped state, the change rate of the detected angular velocity is a predetermined prohibition change rate threshold value. In such a case, if the calibration is configured to be prohibited, for example, the vehicle rotates on the turntable while the vehicle is traveling and the turntable rotates when the vehicle is kept stopped on the turntable. When the control is started, the value of the change rate of the detected yaw rate as the detected angular velocity is surely equal to or greater than the prohibition change rate threshold value, and the calibration of the detected yaw rate can be reliably prohibited. As a result, even if the target rotational speed of the turntable is relatively slow, it is possible to reliably prevent erroneous calibration or the like due to the rotation of the turntable described above.

  Furthermore, when the turntable starts to rotate, the change speed (increase) of the rotation speed of the turntable can appear as a large value immediately after the start of the rotation. Therefore, the calibration of the detected yaw rate is prohibited from an earlier stage after the time when the rotation of the turntable is started, as compared with the apparatus described in Patent Document 1 that compares the value of the detected yaw rate itself with a predetermined value. As a result, it is possible to more reliably prevent erroneous calibration or the like due to the rotation of the turntable described above.

  Another feature of the present invention is a vehicle including vehicle body speed acquisition means, angular speed detection means, stop state determination means, and detection angular speed calibration means, in the same manner as the angular velocity detection device according to the characteristics of the present invention. The angular velocity detection device includes an angle acquisition means for acquiring an angle related to the behavior of the vehicle body and corresponding to the angular velocity, and the vehicle is stopped after the vehicle state shifts from the running state to the stopped state. The amount of change of the acquired angle from the angle acquired at the time when the vehicle state shifts to the stop state is greater than or equal to a predetermined prohibition angle threshold (or a predetermined value). Calibration prohibiting means for prohibiting the calibration by the detected angular velocity calibration means.

  Here, the angle corresponding to the angular velocity is a yaw angle when the angular velocity is yaw rate, a roll angle when the angular velocity is roll rate, and a pitch angle when the angular velocity is pitch rate. In addition, the angle acquisition means integrates the angular velocity detected by the angular velocity detection means with time by a predetermined calculation even if the angle is acquired by directly directly detecting the angle. It may be configured to acquire the same angle by estimating the same angle.

  According to this, by setting the forbidden angle threshold to a value corresponding to an angle change that cannot normally occur when the vehicle is stopped, for example, a vehicle that has moved on the turntable When the turntable is turned on and rotated by an angle equal to the prohibition angle threshold, calibration of the detected yaw rate as the detected angular velocity can be reliably prohibited. As a result, this also prevents erroneous calibration due to the rotation of the turntable described above even when the target rotation speed of the turntable is relatively slow. This also ensures an opportunity to calibrate the detected angular velocity even when the vehicle is stopped, and as a result, it is possible to prevent a decrease in the accuracy of the calibration.

  In this case, the calibration prohibiting means acquires the angle obtained when a predetermined time has elapsed from the time when the state of the vehicle has shifted to the stopped state, and when the state of the vehicle has shifted to the stopped state. It is preferable that the calibration by the detected angular velocity calibration means is prohibited when the amount of change from the set angle is equal to or greater than the prohibition angle threshold (or the prohibition angle threshold).

  In general, the period from when the vehicle moving on the turntable is stopped to when the turntable starts to rotate is often relatively short. Therefore, the time required for the turntable to rotate by an angle equal to the forbidden angle threshold after the vehicle moving on the turntable is stopped is often relatively short.

  Therefore, for example, a time corresponding to such a short period is set as a predetermined time, and the vehicle at the yaw angle at the time when the predetermined time has elapsed since the vehicle moving on the turntable is stopped is stopped. If it is determined whether or not the amount of change from the yaw angle at the time of the state has reached the forbidden angle threshold, it is determined whether or not the vehicle is stopped on the rotating turntable. A more accurate determination can be made. From the above, if configured as described above, it is possible to more accurately determine whether or not to prohibit calibration of the detected angular velocity, and as a result, it is more erroneous due to the rotation of the turntable described above. Calibration and the like can be prevented from being executed.

  In any one of the angular velocity detection devices described above, the detected angular velocity calibration means prohibits the calibration by a predetermined design value for the zero point correction amount while the calibration is prohibited by the calibration prohibition means. A value based on the latest zero point correction amount obtained at the time point and the zero point correction amount already obtained at the time point when the calibration is prohibited and stored in a predetermined storage unit Are set as a temporary zero point correction amount, and the detected angular velocity value detected by the angular velocity detection means is corrected based on the temporary zero point correction amount. It is.

  Here, the predetermined value in the design is, for example, zero. Further, the value based on the zero point correction amount already obtained when the calibration is prohibited is, for example, a plurality of zeros already obtained in the past (that is, before the calibration is prohibited). This is the average value of the point correction amount. According to this, while the calibration of the detected angular velocity is prohibited, the provisional zero point correction amount can be set to a value considered to be a value close to the true zero point correction amount to be set at the present time. It is possible to correct the detected angular velocity as accurately as possible.

  Further, in any one of the angular velocity detection devices described above, if the calibration is prohibited by the calibration prohibition unit and the change rate of the detected angular velocity is equal to or greater than a predetermined prohibition release change rate threshold, the calibration is prohibited. It is preferable to further include calibration prohibition canceling means for canceling prohibition of the calibration by the prohibiting means.

  Similar to the case where the turntable starts to rotate, when the turntable finishes rotating, in the process in which the rotation speed decreases from the target rotation speed to zero, the change (decrease) speed ( (Absolute value) tends to appear as a relatively large value regardless of the predetermined target rotational speed. Accordingly, even when the turntable stops rotating while the vehicle is stopped on the rotating turntable, the change rate (absolute value) of the detected yaw rate appears as a relatively large value.

  Therefore, as described above, when calibration of the detected angular velocity is prohibited and the change speed (the absolute value thereof) of the detected angular velocity is equal to or greater than a predetermined prohibition release change speed threshold, the calibration is prohibited. If it is configured to cancel, for example, as described above, the vehicle that has moved on the turntable is stopped on the rotating turntable (therefore, calibration of the detected yaw rate is prohibited) ), When the turntable finishes rotating, the detected yaw rate change speed (absolute value) as the detected angular velocity is surely equal to or greater than the prohibition release change speed threshold value, and the detected yaw rate is calibrated reliably. The prohibition is released, and as a result, calibration of the detected yaw rate can be resumed. Therefore, when the vehicle is in a stopped state, it is possible to reliably prohibit calibration of the detected angular velocity only during a period in which erroneous calibration due to the rotation of the turntable described above may be performed. It is possible to secure sufficient opportunities.

  In this case, the calibration prohibition canceling means cancels the prohibition of the detected angular velocity from a value equal to or higher than the prohibition cancel change speed threshold after the change rate of the detected angular velocity becomes equal to or higher than the prohibition cancel change speed threshold. It is preferable that the calibration prohibition is canceled after the time when the value changes to a value less than the change speed threshold.

  When the turntable finishes rotating, the rotational speed change speed of the turntable is maintained at the same value until the rotational speed becomes zero from the time when the rotational speed starts to decrease from the target rotational speed. After the time when the rotation speed becomes zero, it becomes zero. On the other hand, the specific time when the prohibition of the calibration of the detected yaw rate should be canceled is after the time when the rotation speed of the turntable becomes zero.

  From the above, as described above, after the change rate of the detected angular velocity becomes equal to or higher than the prohibition release change rate threshold, the change in the detected angular velocity is canceled from the value equal to or higher than the prohibition release change rate threshold. If it is configured to cancel the prohibition of the calibration after the time when it changes to a value less than the change speed threshold, for example, the calibration of the detected yaw rate can be resumed after the time when the rotation speed of the turntable becomes zero. It is possible to more reliably prevent erroneous calibration or the like due to the rotation of the turntable described above.

  In any one of the angular velocity detection devices described above, when the calibration is prohibited by the calibration prohibition unit and the vehicle body speed is equal to or higher than a predetermined prohibition release speed threshold, the calibration prohibition unit performs the calibration. It is preferable to further include calibration prohibition canceling means for canceling prohibition of calibration.

  As described above, generally, the turntable is in a state where the vehicle moving on the turntable is stopped on the rotating turntable (thus, calibration of the detected yaw rate is prohibited). When the rotation ends, the change speed (absolute value) of the detected yaw rate appears as a relatively large value. However, in the case where the turntable finishes rotating smoothly, that is, when the decrease rate of the rotation speed of the turntable is relatively small, it is the same calibration that the change rate of the detected yaw rate exceeds the prohibition release change rate threshold value. As a condition for canceling the prohibition, the change rate of the detected yaw rate cannot be equal to or greater than the prohibition canceling change speed threshold value. As a result, the prohibition of the same calibration is canceled even if the turntable finishes rotating. An unforeseen situation may occur.

  On the other hand, as described above, if calibration of the detected angular velocity is prohibited and the vehicle body speed is equal to or higher than a predetermined prohibition release speed threshold, the prohibition of the calibration is canceled, For example, when the vehicle starts running after the turntable stops and the vehicle body speed becomes equal to or higher than the prohibition cancellation speed threshold, at least the prohibition of calibration of the detected yaw rate can be reliably canceled, and as a result, Calibration can be reliably restarted.

  In any one of the angular velocity detection devices including the calibration prohibition canceling unit, the detected angular velocity calibration unit is configured to obtain the zero point correction amount when the calibration prohibition is canceled by the calibration prohibition canceling unit. A predetermined design value (for example, zero), the latest zero point correction amount obtained when the calibration is prohibited, and the zero point correction amount already obtained when the calibration is prohibited. A value based on a value (for example, an average value of a plurality of zero point correction amounts, etc.) stored in a predetermined storage means, and detected by the angular velocity detection means when the prohibition of the calibration is released It is preferable that one of the detected angular velocities is set as a temporary zero point correction amount, and the value of the detected angular velocity is corrected based on the temporary zero point correction amount.

  According to this, after the prohibition of the calibration of the detected angular velocity is released, until the new calibration of the detected acceleration is executed, the temporary zero point correction amount is set to the true zero to be set at the present time. It can be set to a value considered to be a value close to the point correction amount, and the detected angular velocity can be corrected as accurately as possible.

  Further, another feature of the present invention is a vehicle including a vehicle body speed acquisition means, an angular speed detection means, a stop state determination means, and a detected angular speed calibration means, as in the angular velocity detection device according to the features of the present invention. The angular velocity detection device is a case where the state of the vehicle is maintained in the stopped state after the ignition switch is changed from the off state to the on state, and the change rate of the detected angular velocity is a predetermined invalid change When it becomes more than a speed threshold value, it exists in providing the calibration invalidation means which invalidates the said calibration already performed by the said detection angular velocity calibration means. Here, “when the change rate of the detected angular velocity is equal to or greater than a predetermined invalidation change rate threshold” means that the invalidation change rate threshold after the change rate becomes equal to or greater than the invalidation change rate threshold. It includes the case where the above value is changed to a value less than the invalidation change speed threshold.

  As described so far, when the vehicle moves on the turntable while traveling and is kept stopped on the turntable (with the ignition switch turned on), it is detected first after that. Utilizing the fact that the change rate of the yaw rate changes to a large value is due to the start of rotation of the turntable and that the change rate of the detected yaw rate changes to a large value for the second time is due to the end of rotation of the turntable. In addition, it is possible to determine the timing for prohibiting the calibration of the detected yaw rate and the timing for canceling the prohibition of the calibration.

  However, after the ignition switch (hereinafter sometimes referred to as “IG”) is changed from the off state to the on state while the vehicle is stopped on the turntable, the vehicle is maintained in the stopped state. If the detected yaw rate change rate subsequently changes to a large value (once or multiple times), the current change in the detected yaw rate change rate is caused by the start of rotation of the turntable. It is not possible to distinguish whether it is due to the end of rotation of the turntable.

  In other words, if the change rate of the detected yaw rate changes to a large value, the calibration of the detected yaw rate before the time of the change should be accurate and the calibration should be prohibited after the same point, or the simultaneous point The previous calibration has an error corresponding to the rotational speed of the turntable, and it cannot be distinguished whether the calibration after the same point is accurate. In such a case, the detected yaw rate is already calibrated every time the change rate of the detected yaw rate changes to a large value until the vehicle starts moving (that is, until the vehicle moves from the turntable). It is considered preferable to disable the calibration as the accuracy of

  Therefore, as described above, it is detected when the vehicle is maintained in the stopped state after the ignition switch is changed from the OFF state to the ON state (hereinafter referred to as “IG: ON”). If the angular velocity change rate is equal to or greater than a predetermined invalidation change velocity threshold value, the detection yaw rate can be calculated based on a calibration with doubtful accuracy, for example, if the calibration of the detected angular velocity already performed is invalidated. It is prevented from being calibrated.

  In this case, when the calibration is invalidated by the calibration invalidation means, the detected angular velocity calibration means changes a predetermined design value for the zero point correction amount from the off state to the on state. One of the value based on the zero point correction amount stored in the predetermined storage unit at the time of the change and the detected angular velocity detected by the angular velocity detection unit at the time when the calibration is invalidated. It is preferable that the provisional zero point correction amount is set and the value of the detected angular velocity is corrected based on the temporary zero point correction amount.

  According to this, after the calibration of the detected angular velocity is invalidated, until the new calibration of the detected acceleration is executed, the temporary zero correction amount is set to the true zero point to be set at the present time. It can be set to a value considered to be a value close to the correction amount, and the detected angular velocity can be corrected as accurately as possible.

  Hereinafter, an embodiment of a vehicle angular velocity detection device according to the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of a vehicle equipped with a vehicle motion control device 10 including a vehicle angular velocity detection device according to an embodiment of the present invention. This vehicle is a four-wheel vehicle including a pair of front wheels (left front wheel FL and right front wheel FR) that are steering wheels and a pair of rear wheels (left rear wheel RL and right rear wheel RR) that are non-steering wheels. .

  The vehicle motion control device 10 includes a front wheel steering mechanism 20 for turning the steered wheels FL and FR, a brake hydraulic pressure control device 30 for generating braking force by brake hydraulic pressure on each wheel, The sensor unit 40 including various sensors and an electric control device 50 are included.

  The front wheel steering mechanism 20 includes a steering wheel 21, a column 22 that can rotate integrally with the steering wheel 21, a steering actuator 23 connected to the column 22, and the steering actuator 23 in the left-right direction of the vehicle body. A link mechanism portion 24 including a tie rod to be moved and a link capable of turning the steered wheels FL and FR by the movement of the tie rod. As a result, the steering angle of the steered wheels FL, FR is changed from the reference angle at which the vehicle goes straight by rotating the steering 21 from the neutral position (reference position).

  The brake fluid pressure control device 30 includes a plurality of solenoid valves (not shown), and independently controls the brake fluid pressure in the wheel cylinders Wfl, Wfr, Wrl, Wrr of each wheel regardless of the operation of the brake pedal BP. A predetermined braking force can be applied independently for each wheel. Since the detailed configuration and operation of the brake fluid pressure control device 30 are well known, a detailed description thereof will be omitted here.

  The sensor unit 40 includes wheel speed sensors 41fl, 41fr, 41rl as vehicle body speed acquisition means configured by a rotary encoder that outputs a signal having a pulse each time the wheels FL, FR, RL, and RR rotate by a predetermined angle. 41rr, a steering angle sensor 42 that detects a rotation angle from the neutral position of the steering wheel 21 and outputs a signal indicating the steering angle θs, and a yaw rate that is an angular velocity related to the behavior of the vehicle body generated in the vehicle body is detected. And a yaw rate sensor 43 as an angular velocity detecting means for outputting a signal indicating the detected yaw rate Yr.

  The steering angle θs is “0” when the steering wheel 21 is in the neutral position, and is a positive value when the steering wheel 21 is rotated counterclockwise (as viewed from the driver) from the neutral position. The value is set to be a negative value when the steering wheel 21 is rotated in the clockwise direction from the position.

  The electric control device 50 includes a CPU 51 connected to each other by a bus, a routine (program) executed by the CPU 51, a table (lookup table, map), a ROM 52 in which constants are stored in advance, and the CPU 51 temporarily stores data as necessary. The microcomputer includes a RAM 53 for storing data, a backup RAM 54 for storing data while the power is on, and holding the stored data while the power is shut off, an interface 55 including an AD converter, and the like. . The interface 55 is connected to the sensors 41 to 43, supplies signals from the sensors 41 to 43 to the CPU 51, and sends drive signals to the electromagnetic valves and the like of the brake fluid pressure control device 30 in accordance with instructions from the CPU 51. It is supposed to be.

  As a result, the brake hydraulic pressure control device 30 performs vehicle stability such as well-known anti-skid (ABS) control, traction control, and front / rear braking force distribution control according to the outputs of the sensors 41 to 43 including the yaw rate sensor 43. Various controls based on the brake fluid pressure for maintaining the above are executed.

(Outline of calibration method of detection yaw rate Yr according to the present invention)
Next, an outline of the calibration method of the detected yaw rate Yr performed by the vehicle motion control device 10 (hereinafter, also referred to as “this device”) including the vehicle angular velocity detection device according to the embodiment of the present invention will be described. To do.

(Normal calibration)
The yaw rate sensor 43 described above is configured to detect the yaw rate generated in the vehicle body using a rate gyro. Therefore, a so-called drift due to the temperature characteristic or the like can occur, and as a result, an error occurs at the zero point of the detected yaw rate Yr. Therefore, it is necessary to calibrate the zero point of the detected yaw rate Yr at a predetermined frequency. On the other hand, as a case where the actual yaw rate value acting on the vehicle body becomes zero, there are a case where the vehicle is in a stopped state and a case where the vehicle is traveling straight ahead.

  From the above, in principle, this apparatus determines whether or not the vehicle is in a stopped state or a straight traveling state at every calculation cycle of the CPU 51. If it is determined that the current value of the detected yaw rate Yr is zero, the zero point correction amount Yrcalib (= Yr) for setting the current detected yaw rate Yr to zero is obtained (updated), and a new (updated) zero point is obtained. The corrected yaw rate Yrfin (in this case, always “0”) is calculated by subtracting the correction amount Yrcalib from the detected yaw rate Yr. The means for calculating the post-calibration yaw rate Yrfin in this way corresponds to the detected angular velocity calibration means.

  On the other hand, when it is determined that the vehicle is not in any of the above states, that is, when the vehicle is running and not moving straight, the actual yaw rate value acting on the vehicle body is not zero, As a result, if calibration of the zero point of the detected yaw rate Yr is executed, it is considered that an error occurs in the calibration. Therefore, in this case, the apparatus prohibits the calibration (specifically, does not newly update the zero point correction amount Yrcalib), and at the same time, the latest zero point correction amount Yrcalib (that is, immediately before the calibration is prohibited). The detected yaw rate Yr is corrected by subtracting the updated value from the current detected yaw rate Yr (formally, the post-calibration yaw rate Yrfin is calculated). Since the value of the latest zero point correction amount Yrcalib is considered to be a value close to the true zero point correction amount to be set at the present time, the corrected detected yaw rate Yr (that is, the post-calibration yaw rate Yrfin) is It can be a value close to the yaw rate actually occurring in the vehicle body. The calibration in the normal case has been described above.

(Consideration when the vehicle is stopped on the turntable)
As described above, when the vehicle is stopped on a turntable set in a multilevel parking lot or the like, when the turntable rotates, the vehicle actually has a yaw rate equal to the rotation speed of the turntable. Occur. Therefore, even if the vehicle is in a stopped state, if the zero point calibration of the detected yaw rate Yr is executed in such a case, the value of the post-calibration yaw rate Yrfin is equal to the rotation speed of the turntable. An error occurs. Therefore, when the vehicle is stopped, it is necessary to prevent such erroneous calibration from being executed.

<When the vehicle enters the turntable and stops on the turntable>
First, the case where the vehicle shown in FIG. 1 enters while traveling on the turntable and is stopped with IG: ON on the turntable will be described with reference to FIG. FIG. 2 shows the detected yaw rate Yr and the detection when the vehicle enters the turntable, stops on the turntable at time t0, and is then maintained in the stopped state with IG: ON. 6 is a time chart showing an example of a change in yaw rate change speed (time differential value of detected yaw rate) DYr. The turntable starts to rotate at time t1, and the rotation speed increases from “0” to a predetermined target rotation speed at a predetermined rotation speed from time t1 until time t2, and from time t2. Maintained at the same target rotational speed until time t3, after time t3, decreases from the target rotational speed to “0” at a predetermined rotational decrease speed until time t4, and maintains “0” after time t4. And

  In this case, at least after time t0 when the vehicle is stopped, in principle, the calibration of the zero point of the detected yaw rate Yr is continuously performed (specifically, the zero point correction amount Yrcalib is sequentially updated). On the other hand, since the actual yaw rate value acting on the vehicle body is not zero from time t1 to time t4, it is necessary to prohibit calibration of the zero point of the detected yaw rate Yr. In other words, it is necessary to detect time t1 when the stopped turntable starts rotating and time t4 when the rotating turntable stops.

  Here, as shown in FIG. 2, the value of the yaw rate Yr detected by the yaw rate sensor 43 changes (assuming that the calibration error of the detected yaw rate Yr is small) in the same manner as the rotation speed of the turntable described above. For this reason, as shown in FIG. 2, the value of the change rate DYr of the detected yaw rate suddenly changes from approximately “0” to a large value (positive value) equal to the rotational speed of the turntable at time t1, During the time t1 to the time t2, the same large value is maintained, and at the time t2, the large large value again suddenly changes to substantially “0”. The value of the detected yaw rate change speed DYr is maintained at approximately “0” from time t2 to time t3, and then at a large value equal to the rotation reduction speed of the turntable from approximately “0” at time t3. It changes suddenly to a negative value) and is maintained at the same large value from time t3 to time t4, and suddenly changes from the same large value to substantially “0” again at time t4.

  If attention is paid to the change in the value of the change speed DYr of the detected yaw rate, the time t1, which is the time when the stopped turntable starts to rotate, is after the time t0 when the vehicle shifts from the running state to the stopped state. First, it can be detected as the time when the absolute value of the change rate DYr of the detected yaw rate changes from less than a predetermined threshold (prohibited change rate threshold) DYrth to more than the same DYrth. The time t4 when the rotating turntable stops can be detected as the time when the absolute value of the change speed DYr of the detected yaw rate changes from the above threshold value DYrth to less than the same DYrth for the second time after the time t1.

  In view of the above, this apparatus first detects that the absolute value of the detected yaw rate change speed DYr is less than the threshold value DYrth after the vehicle moves from the running state to the stopped state (with the IG: ON state). From this point on, when the absolute value of the change rate DYr of the detected yaw rate changes from the above threshold value DYrth to less than the same DYrth, the zero point of the detected yaw rate Yr is calibrated. (Specifically, updating of the zero point correction amount Yrcalib is prohibited). The means for prohibiting the calibration in this way corresponds to the calibration prohibiting means.

  At the same time, while the apparatus continues to prohibit calibration of the zero point of the detected yaw rate Yr, the latest zero point correction amount Yrcalib (provisional zero point correction amount. In FIG. 2, the value updated immediately before time t1. ) Is subtracted from the current detected yaw rate Yr to correct the detected yaw rate Yr (formally, the yaw rate Yrfin after calibration is calculated). Since the value of the latest zero point correction amount Yrcalib is considered to be a value close to the true zero point correction amount to be set at the present time, the corrected detected yaw rate Yr (that is, the post-calibration yaw rate Yrfin) is It can be a value close to the yaw rate actually occurring in the vehicle body.

  Then, when the absolute value of the change rate DYr of the detected yaw rate changes from the threshold value DYrth to less than the same DYrth for the second time, the apparatus cancels the prohibition of calibration, and after the simultaneous point (more specifically, (After the calculation time of the next CPU 51 at the same time) The calibration is resumed. The means for canceling the prohibition of calibration in this way corresponds to the calibration prohibition canceling means. Even when the prohibition of the calibration is canceled, the present apparatus uses the latest zero point correction amount Yrcalib (temporary zero point correction amount; the value updated immediately before time t1 in FIG. 2) at the present time. The detected yaw rate Yr is corrected by subtracting from the detected yaw rate Yr. As described above, the case where the vehicle has entered while traveling on the turntable and IG: ON is stopped on the turntable has been described.

<When the vehicle is IG: ON on the turntable and stopped on the turntable>
Next, the case where the vehicle shown in FIG. 1 is IG: ON on the turntable and is stopped with IG: ON on the turntable will be described with reference to FIG. In FIG. 3, times t11, t12, t13, and t14 correspond to times t1, t2, t3, and t4 in FIG. 2, respectively, and the change in the rotational speed of the turntable at times t11 to t14 (accordingly, the detected yaw rate Yr, The transition of the change rate DYr of the detected yaw rate) is the same as that at times t1 to t4 in FIG.

  Even when the vehicle is in a stopped state after IG: ON on the turntable, in principle, calibration of the zero point of the detected yaw rate Yr described above continues to be performed sequentially after IG: ON. On the other hand, in this case as well, as in the case shown in FIG. 2, it is necessary to prohibit calibration of the zero point of the detected yaw rate Yr from time t11 to time t14, so that the stopped turntable starts to rotate. It is necessary to detect the time t11 which is the time and the time t14 when the rotating turntable stops.

  However, if the time when IG: ON is before the turntable starts rotating (see, for example, time t10 in FIG. 3), the change rate DYr of the detected yaw rate is first set after the time when IG: ON. While the change to a large value is caused by the start of rotation of the turntable, the time when IG: ON is a time point during the rotation of the turntable (for example, see time t10 ′ in FIG. 3). Is caused by the end of the rotation of the turntable that the change rate DYr of the detected yaw rate first changes to a large value after the IG: ON time.

  In other words, if the change rate DYr of the detected yaw rate has changed to a large value (once or multiple times) after IG: ON, is this change due to the start of rotation of the turntable? It cannot be distinguished whether it is caused by the end of rotation of the turntable. Therefore, the period during which the calibration should be prohibited (time t11 to t14 in FIG. 3) cannot be defined.

  In such a case, until the vehicle starts after that (that is, until the vehicle moves from the turntable), every time the change rate DYr of the detected yaw rate changes to a large value (more specifically, Every time the detection yaw rate change rate DYr returns to a small value immediately after it has changed to a large value, it is preferable to invalidate the calibration because the accuracy of the calibration of the detection yaw rate Yr already performed is doubtful. It is done.

  From the above, in the present apparatus, the absolute value of the change rate DYr of the detected yaw rate changes from the above threshold value DYrth to less than the same DYrth as long as the vehicle is maintained in the stopped state after the time when IG: ON is turned on. Every time (in FIG. 3, time t12 or t14), the calibration of the zero point of the detected yaw rate Yr already performed is invalidated. Specifically, the present apparatus corrects the detected yaw rate Yr by subtracting the value of the zero point correction amount storage value (temporary zero point correction amount) Yrmemory stored in the backup RAM 54 from the current detected yaw rate Yr. (Formally, calculate yaw Yrfin after calibration).

  The means for invalidating the calibration in this way corresponds to the calibration invalidating means. The zero point correction amount storage value Yrmemory is an average value of a plurality of zero point correction amounts Yrcalib calculated when the vehicle is running before the current IG: ON, as will be described in detail later. The correction amount Yrcalib is a highly reliable value.

  Note that this apparatus has a period from the time when the absolute value of the change rate DYr of the detected yaw rate changes from less than the above threshold value DYrth to more than the same DYrth to the time when the absolute value of the detected yaw rate changes from less than the same value DYrth to less than the same DYrth ( Detected by subtracting the latest zero point correction amount Yrcalib (value updated immediately before time t11 or t13 in FIG. 3) from the current detected yaw rate Yr at time t11 to t12 or time t13 to t14) Yaw rate Yr is corrected (formally, yaw rate Yrfin is calculated after calibration).

  Then, when the calibration of the zero point of the detected yaw rate Yr is invalidated as described above (time t12 or t14 in FIG. 3), this apparatus performs the calibration again from the next calculation time of the CPU 51. (Specifically, the zero point correction amount Yrcalib is sequentially updated.) The case where the vehicle is IG: ON on the turntable and stopped on the turntable has been described above.

  In this way, when the vehicle is in a stopped state, it is possible to reliably prevent erroneous calibration of the zero point of the detected yaw rate Yr due to the rotation of the turntable described above, and Sufficient opportunities for the calibration can be secured. In addition, the value of the detected yaw rate Yr (that is, the post-calibration yaw rate Yrfin) corrected while such calibration is prohibited (or disabled) is close to the yaw rate actually generated in the vehicle body. obtain. Therefore, the value of the post-calibration yaw rate Yrfin can always be a reliable value, and as a result, the various brake fluid pressure controls described above performed by the present apparatus using such a value can be appropriately executed.

(Actual operation)
FIG. 4 is a flowchart showing a routine executed by the CPU 51 of the electric control device 50 for the actual operation of the vehicle motion control device 10 including the vehicle angular velocity detection device according to the present invention configured as described above. A description will be given with reference to FIG. Each of these routines is executed while the IG is in the ON state.

  The CPU 51 repeatedly executes the routine for calculating the post-calibration yaw rate Yrfin shown in FIG. 4 every elapse of a predetermined time (calculation cycle Δt, for example, 6 msec). Accordingly, when the predetermined timing is reached, the CPU 51 starts processing from step 400, proceeds to step 402, and determines whether or not the IG has been changed from the OFF state to the ON state.

  If it is assumed that the driver has just changed the IG from the OFF state to the ON state while the vehicle is stopped on a normal (stationary) road surface, the CPU 51 determines “Yes in step 402. The process proceeds to step 404, where the value of the prohibition flag PRO is initialized to “0”. In the subsequent step 406, the value of the travel flag RUN is initialized to “0”, and in the subsequent step 408, the detected yaw rate is detected. The value of the change speed DYr is initially set to “0”, and the zero point correction amount Yrcalib is initially set to the zero point correction amount storage value Yrmemory currently stored in the backup RAM 54 in step 410. The zero point correction amount storage value Yrmemory is a value that is appropriately updated by a routine described later.

  Here, when the value of the prohibition flag PRO is “1”, it indicates that the calibration of the detected yaw rate Yr is prohibited (that is, the update of the zero point correction amount Yrcalib is prohibited). When "0" indicates that calibration of the detected yaw rate Yr is not prohibited. Further, when the value of the travel flag RUN is “1”, it indicates that the vehicle has traveled since IG: ON. When the value of the travel flag RUN is “0”, the vehicle is This indicates that there is no history of travel (that is, the vehicle is maintained in a stopped state).

  Next, the CPU 51 proceeds to step 424 to subtract the current zero point correction amount Yrcalib (currently, the zero point correction amount storage value Yrmemory) from the value of the detected yaw rate Yr detected by the yaw rate sensor 43 at the present time. The value is calculated as yaw rate Yrfin after calibration. Then, the CPU 51 proceeds to step 426, stores the current detected yaw rate Yr value as the previous detected yaw rate Yrb, and sets the current detected yaw rate change rate DYr as the previous detected yaw rate change rate DYrb. After the storage, the routine proceeds to step 495 and this routine is temporarily terminated.

  Thereafter, when repeatedly executing this routine, the CPU 51 determines “No” when it proceeds to step 402 and proceeds to step 412. When the CPU 51 proceeds to step 412, the value obtained by subtracting the previous detected yaw rate Yrb stored in the previous step 426 from the detected yaw rate Yr detected by the yaw rate sensor 43 at this time is divided by the calculation period Δt of this routine. The value (that is, the time differential value of the detected yaw rate Yr) is stored as the detected yaw rate changing speed DYr. At the present stage, since the vehicle is stopped on the normal road surface, the change speed DYr of the detected yaw rate becomes a small value (approximately “0”).

  Subsequently, the CPU 51 proceeds to step 414, where the wheel speed sensor 41 ** (where “**” represents one of the wheels FL, FR, RL, RR. The same applies hereinafter). The wheel speed Vw ** of each wheel is obtained on the basis of the respective outputs, and the estimated vehicle body speed Vso is obtained from the wheel speed Vw ** and the function f.

  Next, the CPU 51 proceeds to step 416 to determine whether or not the estimated vehicle body speed Vso is larger than a predetermined stop state determination reference value Vth (for example, “0”). This step 416 corresponds to a stop state determination means. At the present stage, since the vehicle is stopped, the CPU 51 determines “No” and proceeds to Step 418 to determine whether or not the value of the prohibition flag PRO is “0”.

  At the present stage, since the value of the prohibition flag PRO is “0” in the execution of the previous step 404, the CPU 51 determines “Yes” in step 418 and proceeds to step 420, where the previous detected yaw rate is determined. It is determined whether the absolute value of the change rate DYrb is less than the threshold value DYrth and the absolute value of the detected yaw rate change rate DYr is equal to or greater than the threshold value DYrth.

  At this stage, as described above, since the change rate DYr of the detected yaw rate is a small value (that is, less than the threshold value DYrth), the CPU 51 makes a “No” determination at step 420 and proceeds to step 422. The value of the detected yaw rate Yr at is set as the zero point correction amount Yrcalib. In step 424, the CPU 51 stores a value obtained by subtracting the zero point correction amount Yrcalib from the current detected yaw rate Yr (“0” at this stage) as a post-calibration yaw rate Yrfin. Step 426 described above is executed again, and then the routine proceeds to step 495 to end the present routine tentatively. As a result, the value of the zero point correction amount Yrcalib is updated and the zero point of the detected yaw rate Yr is calibrated.

  Thereafter, the CPU 51 repeatedly executes a series of steps 400, 402, 412-426, and 495 as long as the vehicle is stopped on a normal road surface. As a result, the zero point of the detected yaw rate Yr is calibrated every calculation period Δt of this routine.

  Next, a case will be described in which the vehicle starts from this state and travels (the estimated vehicle body speed Vso is larger than the stop state determination reference value Vth). In this case, when the CPU 51 proceeds to step 416, it determines “Yes” and proceeds to step 428. In step 428, the value of the travel flag RUN is set to “1”, and in step 430, the steering angle is increased. It is determined whether or not the current absolute value of the steering angle θs detected by the sensor 42 is less than a predetermined straight traveling state determination reference value θth (small positive value).

  If the CPU 51 determines “Yes”, it executes the processes 422 to 426 described above, assuming that the vehicle is traveling straight ahead, and then proceeds to step 495 to end this routine once. Thereafter, the CPU 51 repeatedly executes a series of processes of steps 400, 402, 412 to 416, 428, 430, 422 to 426, and 495 as long as the vehicle is traveling straight ahead. As a result, in this case as well, the value of the zero point correction amount Yrcalib is updated and the zero point of the detected yaw rate Yr is calibrated every calculation cycle Δt of this routine.

  On the other hand, if the CPU 51 determines “No” in the determination at step 430, it executes the process of step 422 (accordingly, the update process of the zero point correction amount Yrcalib) assuming that the vehicle is traveling and not moving straight ahead. Without performing this, the processing of steps 424 and 426 is executed. As a result, in this case, calibration of the detected yaw rate Yr is prohibited, and detection is performed by subtracting the latest zero point correction amount Yrcalib (that is, a value updated immediately before the start of traveling) from the current detected yaw rate Yr. Yaw rate Yr is corrected (yaw rate Yrfin is calculated after calibration).

  As described above, the case where the vehicle is stopped on the normal road surface and the case where the vehicle is running have been described. Next, a case where the vehicle enters the turntable while traveling and stops on the turntable (IG: remains in the ON state) (see time t0 and after in FIG. 2) will be described.

  In this case, as long as the turntable is stopped, the CPU 51 performs a series of steps 400, 402, 412 to 426, 495, as in the case where “the vehicle is stopped on the normal road surface” described above. The process is repeatedly executed, and as a result, the zero point of the detected yaw rate Yr is calibrated. Similarly to the case where the vehicle is stopped on a normal road surface, the change speed DYr (= DYrb) of the detected yaw rate is maintained at a small value (substantially “0”).

  On the other hand, assuming that the turntable has started to rotate (see time t1 in FIG. 2), the absolute value of the change rate DYrb of the previous detected yaw rate remains small, but is calculated by executing step 412. Since the absolute value of the change speed DYr of the detected yaw rate becomes a large value (above the threshold value DYrth), the CPU 51 makes a “Yes” determination when proceeding to step 420 and proceeds to step 432.

  In step 432, the CPU 51 sets the value of the prohibition flag PRO to “1”, sets the value of the counter M to “0” in the subsequent step 434, and then performs the processing in step 422 (accordingly, the zero point correction amount). Steps 424 and 426 are executed without executing the Yrcalib update process. The counter M will be described later.

  Thereby, prohibition of calibration of the detected yaw rate Yr is started, and the latest zero point correction amount Yrcalib (that is, a value updated immediately before the start of turntable rotation corresponding to the time t1) is detected at the present time. The detected yaw rate Yr is corrected by subtracting from (yaw rate Yrfin after calibration is calculated).

  Thereafter, since the value of the prohibition flag PRO is “1”, the CPU 51 determines “No” when it proceeds to step 418 and proceeds to step 436. When the CPU 51 proceeds to step 436, it determines whether or not the value of the travel flag RUN is “1”. At the present time, because the value of the travel flag RUN has been set to “1” by the processing of the previous step 428 (that is, because the vehicle has traveled since IG: ON), the CPU 51 determines “ It is determined as “Yes”, and the process proceeds to Step 438.

  When the CPU 51 proceeds to step 438, the absolute value of the change rate DYrb of the previous detected yaw rate is equal to or greater than the threshold value DYrth, and the absolute value of the change rate DYr of the detected yaw rate is less than the threshold value DYrth. It is determined whether or not. Here, the absolute value of the change speed DYr of the detected yaw rate is a large value (threshold value DYrth or more) until the time when the rotation speed of the turntable reaches the target rotation speed (see time t2 in FIG. 2) arrives. Therefore, at the present stage, both the absolute value of DYr and the absolute value of DYrb are equal to or greater than the same threshold value DYrth.

  Therefore, the CPU 51 makes a “No” determination at step 438 to execute the processing at steps 426 and 428 without executing the processing at step 422 (and hence the zero point correction amount Yrcalib update processing). Thereafter, the CPU 51 repeatedly executes the processes of steps 400, 402, 412-418, 436, 438, 424, 426, and 495 until the rotational speed of the turntable reaches the target rotational speed. Thus, the prohibition of the calibration of the detected yaw rate Yr is continued, and the latest zero point correction amount Yrcalib (that is, the value updated immediately before the start of the turntable rotation corresponding to the time t1) is detected at the present time. The detected yaw rate Yr continues to be corrected by subtracting from (yaw rate Yrfin after calibration continues to be calculated).

  Next, assuming that the rotation speed of the turntable has reached the target rotation speed from this state, the absolute value of the change speed DYrb of the previous detected yaw rate is maintained at a large value (a value equal to or greater than the threshold value DYrth). On the other hand, the absolute value of the change rate DYr of the detected yaw rate changes to a small value (a value less than the threshold value DYrth). Therefore, when the CPU 51 proceeds to step 438, it determines “Yes” and proceeds to step 440. Then, a value obtained by increasing the value of the counter M at that time (currently “0”) by “1” is set as a new value of the counter M. That is, the absolute value of the change rate DYr of the detected yaw rate is the threshold value after the time when the value of the counter M is set to “0” in the previous step 434 (that is, the time when the turntable starts to rotate). Indicates the number of changes from a value greater than or equal to DYrth to a value less than the same threshold value DYrth.

  Subsequently, the CPU 51 proceeds to step 442 and determines whether or not the value of the counter M is “2”. Since the value of the counter M is “1” at the present time, the CPU 51 determines “No” in step 442 and executes the process of step 422 (and thus the zero point correction amount Yrcalib update process) without executing the process. Processes 426 and 428 are executed. Thereafter, the CPU 51 continues to steps 400, 402, 412 to 418, 436, until it is determined as “Yes” in step 438 (when the rotation of the turntable corresponding to time t4 in FIG. 2 stops). The processes of 438, 424, 426, and 495 are repeatedly executed. Thus, the prohibition of the calibration of the detected yaw rate Yr is further continued, and the latest zero point correction amount Yrcalib (that is, the value updated immediately before the start of the turntable rotation corresponding to the time t1) is calculated from the current detected yaw rate Yr. By subtracting, the detected yaw rate Yr continues to be corrected (post-calibration yaw rate Yrfin continues to be calculated).

  Next, assuming that the rotation of the turntable is stopped from this state, the CPU 51 determines “Yes” when it proceeds to step 438, proceeds to step 440, and increments the value of the counter M. As a result, since the value of the counter M becomes “2”, the CPU 51 determines “Yes” in Step 442 and proceeds to Step 444 to change the value of the prohibition flag PRO from “1” to “0”. The processes of steps 426 and 428 are executed without executing the process of step 422 (and hence the zero point correction amount Yrcalib update process). Thereby, the prohibition of the calibration of the detection yaw rate Yr described above is further continued.

  Thereafter, since the value of the prohibition flag PRO is “0”, the CPU 51 determines “Yes” when it proceeds to step 418 and proceeds to step 420. At the present time, since the vehicle is in a stop state similar to the previous “when the vehicle is in a stop state on a normal road surface”, the CPU 51 determines “No” in step 420 and performs the processing of step 422 (accordingly, Then, the zero point correction amount Yrcalib update process) is resumed. As a result, the prohibition of the calibration of the detected yaw rate Yr is canceled, and the calibration of the detected yaw rate Yr is resumed in step 424.

  As described above, the case where the vehicle enters the turntable while traveling and stops on the turntable (IG: remains in the ON state) has been described. Next, the case where IG: ON is turned on on the turntable where the vehicle is stopped (see time t10 in FIG. 3), and the case where IG: ON is stopped on the turntable will be described.

  In this case, the CPU 51 repeatedly executes the processes of Steps 402, 412 to 426, and 495 until the turntable starts rotating after IG: ON (see time t11 in FIG. 3). As a result, the value of the zero point correction amount Yrcalib is updated and the zero point of the detected yaw rate Yr is calibrated. At this stage, the value of the running flag RUN remains maintained at “0” by the processing of step 406 at the time of IG: ON.

  When the turntable starts to rotate, the CPU 51 determines “Yes” when it proceeds to step 420 and proceeds to steps 432 and 434, whereby the value of the prohibition flag PRO is changed from “0” to “1”. The Therefore, thereafter, when the CPU 51 proceeds to step 418, it determines “No” and proceeds to step 436.

  At the present stage, the value of the travel flag RUN remains maintained at “0” (that is, since the vehicle has not traveled since IG: ON), the CPU 51 determines “No” in step 436. Then, the process proceeds to step 446 where the same determination process as in the previous step 438 is performed. Here, as described above, the determination condition of step 438 (and hence the determination condition of step 446) is the time when the rotation speed of the turntable reaches the target rotation speed (see time t12 in FIG. 3). Alternatively, it does not hold until the time when the rotation of the turntable stops (see time t14 in FIG. 3) has arrived.

  Accordingly, at this stage, the CPU 51 makes a “No” determination at step 446 to execute the processing at steps 426 and 428 without executing the processing at step 422 (and hence the zero point correction amount Yrcalib update processing). To do. Thereafter, the CPU 51 repeatedly executes the processes of steps 400, 402, 412-418, 436, 446, 424, 426, and 495 until the rotational speed of the turntable reaches the target rotational speed. Accordingly, the prohibition of the calibration of the detected yaw rate Yr is continued, and the latest zero point correction amount Yrcalib (that is, the value updated immediately before the start of turntable rotation corresponding to the time t11) is subtracted from the current detected yaw rate Yr. As a result, the detected yaw rate Yr continues to be corrected (yaw rate Yrfin after calibration continues to be calculated).

  From this state, assuming that the rotational speed of the turntable has reached the target rotational speed, the CPU 51 determines “Yes” when it proceeds to step 446, proceeds to step 448, and sets the value of the prohibition flag PRO to “1”. ”To“ 0 ”, and the zero point correction amount stored value Yrmemory (currently stored at the time of ON), which will be described later, stored in the backup RAM 54 in the next step 450 is zero point corrected. The amount Yrcalib is set, and the processing in steps 426 and 428 is executed without executing the processing in step 422 (accordingly, the zero point correction amount Yrcalib update processing).

  As a result, the calibration of the zero point of the detected yaw rate Yr already performed is invalidated. Thereafter, the CPU 51 repeatedly executes the processes of steps 400, 402, 412-426, and 495 until the time when the rotation speed of the turntable starts to decrease from the target rotation speed (see time t13 in FIG. 3). To do. As a result, the value of the zero point correction amount Yrcalib is updated again, and the zero point calibration of the detected yaw rate Yr is resumed. Such calibration includes an error corresponding to the rotational speed of the turntable. Even at the present stage, the value of the running flag RUN remains “0”.

  Then, when the rotation speed of the turntable starts to decrease from the target rotation speed, the CPU 51, like the time from when the turntable starts to rotate until the time when the rotation speed of the turntable reaches the target rotation speed, Until the rotation of the turntable stops (see time t14 in FIG. 3), the inhibition of the calibration of the detected yaw rate Yr is continued again, and the latest zero point correction amount Yrcalib (that is, the turn corresponding to the time t13) is continued. The detected yaw rate Yr is continuously corrected by subtracting the value (updated immediately before the table rotation speed starts decreasing) from the current detected yaw rate Yr (the yaw rate Yrfin after calibration is continuously calculated).

  When the rotation of the turntable stops, the CPU 51 sets the zero point correction amount storage value Yrmemory (IG: a value stored at the time of ON at this stage) as the zero point correction amount Yrcalib. The zero calibration of the detection yaw rate Yr performed is invalidated. Thereafter, the CPU 51 updates the value of the zero point correction amount Yrcalib again and restarts the calibration of the zero point of the detected yaw rate Yr.

  Next, IG: ON is turned on (see time t10 ′ in FIG. 3) on the turntable on which the vehicle is rotating (at the above target rotational speed), and the IG: ON is stopped on the turntable. The case will be described. Also in this case, the value of the zero point correction amount Yrcalib is updated after the time when IG: ON until the time when the rotation speed of the turntable starts to decrease from the target rotation speed (see time t13 in FIG. 3). At the same time, calibration of the zero point of the detected yaw rate Yr is executed. Such calibration includes an error corresponding to the rotational speed of the turntable. Note that at the present stage, the value of the travel flag RUN remains maintained at “0”.

  Then, when the rotation speed of the turntable starts to decrease from the target rotation speed, the CPU 51 prohibits the calibration of the detected yaw rate Yr until the rotation of the turntable stops (see time t14 in FIG. 3). The detected yaw rate Yr is continuously reduced by subtracting the latest zero point correction amount Yrcalib (that is, the value updated immediately before the turntable rotation speed corresponding to the time t13 starts to decrease) from the current detected yaw rate Yr. Continue to correct (continue calculation of yaw rate Yrfin after calibration).

  When the rotation of the turntable stops, the CPU 51 sets the zero point correction amount storage value Yrmemory (IG: a value stored at the time of ON at this stage) as the zero point correction amount Yrcalib. The zero calibration of the detection yaw rate Yr performed is invalidated. Thereafter, the CPU 51 updates the value of the zero point correction amount Yrcalib again and restarts the calibration of the zero point of the detected yaw rate Yr. The routine for executing the calculation of the yaw rate Yrfin after calibration has been described above. The post-calibration yaw rate Yrfin calculated in this way is used when the brake fluid pressure control device 30 executes various controls based on the brake fluid pressure such as the anti-skid (ABS) control, the traction control, and the front / rear braking force distribution control described above. , Will be used sequentially.

  Further, the CPU 51 repeatedly executes the routine shown in FIG. 5 for updating the zero point correction amount storage value Yrmemory every elapse of a predetermined time (for example, 6 msec). Accordingly, when the predetermined timing is reached, the CPU 51 starts the process from step 500 and proceeds to step 505 to determine whether or not the estimated vehicle body speed Vso is larger than the stop state determination reference value Vth (therefore, the vehicle is in the running state). If it is determined “No”, the value of the counter N is cleared to “0” in step 510, and then the process proceeds to step 595 to end the present routine tentatively. That is, the value of the counter N is a value that is cleared to “0” every time the vehicle is stopped.

  Assuming that the vehicle is in a running state, the CPU 51 determines “Yes” in step 505 and proceeds to step 515, immediately after the zero point correction amount Yrcalib is updated in the processing of step 422. If it is determined as “No”, the process proceeds directly to step 595, while if it is determined as “Yes”, the value of the counter N is incremented in subsequent step 520. That is, the value of the counter N represents the total number of times the zero point correction amount Yrcalib has been updated since the transition to the traveling state when the vehicle transitions from the stopped state to the traveling state and is maintained in the traveling state. .

  Subsequently, the CPU 51 proceeds to step 525, stores the current zero point correction amount Yrcalib value in Yrcalib (N), and in step 530, the value of the counter N reaches the predetermined sample number securing reference value Nsum. It is determined whether or not. When determining “No” at step 530, the CPU 51 proceeds directly to step 595, whereas when determining “Yes”, the CPU 51 proceeds to step 535, and Yrcalib (K) (K = 1, 2,... , Nsum−1, Nsum) is updated as a new zero point correction amount storage value Yrmemory, and the updated value is stored in the backup RAM 54. In the subsequent step 540, the value of the counter N is set to “0”. After clearing, the routine proceeds to step 595 to end the present routine tentatively.

  Thus, when the vehicle is in a running state, the zero point correction amount storage value Yrmemory is updated every time the number of updates of the zero point correction amount Yrcalib reaches the sample number securing reference value Nsum, and IG: OFF time Thus, the latest value stored in the backup RAM 54 can be read from the backup RAM 54 even at the subsequent IG: ON time. Note that the value of the zero point correction amount Yrcalib updated when the vehicle is in a running state is a highly reliable value that is not affected by the error due to the rotation of the turntable described above, and is stored in the backup RAM 54. The zero point correction amount storage value Yrmemory is also a highly reliable value in executing the calibration of the zero point of the detected yaw rate Yr.

  As described above, according to the vehicle angular velocity detection device (yaw rate detection device) according to the embodiment of the present invention, in principle, the zero point of the detected yaw rate Yr is calibrated sequentially in the stopped state. Further, it is determined based on the value of the travel flag RUN whether the vehicle has traveled after IG: ON. If the vehicle has traveled (RUN: 1) and the vehicle is in a stopped state, if the absolute value of the detected yaw rate change speed DYr is not less than a predetermined threshold value DYrth for the first time, Thereafter, until the absolute value of the change speed DYr of the detected yaw rate changes to a value less than the threshold value DYrth from the value equal to or higher than the threshold value DYrth for the second time (time t1 to t4 in FIG. 2), the vehicle (IG: The zero point of the detected yaw rate Yr is prohibited from assuming that it is stopped on the turntable and the turntable is rotating.

  As a result, even when the target rotational speed of the turntable is relatively slow, it is possible to reliably prevent erroneous calibration due to the rotation of the turntable. Furthermore, when the vehicle is in a stopped state, it is possible to reliably prohibit the calibration only during a period in which erroneous calibration due to the rotation of the turntable described above may be performed. It was possible to secure sufficient opportunities and to prevent a decrease in the accuracy of the calibration.

  Further, according to this embodiment, when the vehicle has not traveled (travel flag RUN: 0) and the vehicle is in a stopped state, the absolute value of the detected yaw rate change speed DYr is equal to or greater than a predetermined threshold DYrth. Every time the value becomes the value, the vehicle is assumed to be IG: ON on the turntable and stopped on the turntable. When the value changes to a value less than the threshold value DYrth, the zero calibration of the detected yaw rate Yr is invalidated. This prevented the detected yaw rate Yr from being calibrated based on the already performed low-reliability calibration.

  The present invention is not limited to the above embodiment, and various modifications can be employed within the scope of the present invention. For example, in the above embodiment, the start of prohibition of calibration (and hence the start of rotation of the turntable) is determined based on the comparison result between the detected yaw rate change speed DYr and the threshold value DYrth (see step 420). Instead of this, or in addition to this, when the amount of change in the yaw angle of the vehicle from the time when the vehicle shifts from the running state to the stopped state after a predetermined time from the same point, a predetermined reference angle It may be configured such that the start of calibration prohibition is determined when (forbidden angle threshold) (or more).

  In this case, the yaw angle of the vehicle may be detected by a yaw angle sensor that directly detects the yaw angle, or may be estimated by time integrating the value of the yaw rate Yr detected by the yaw rate sensor 43 described above. Good.

  In the above embodiment, the end of the prohibition of calibration (and hence the turntable rotation stop) is determined based on the comparison result between the detected yaw rate change speed DYr and the threshold value DYrth (see step 438). ) When the vehicle body speed (estimated vehicle body speed Vso) exceeds a predetermined value (for example, the stop state determination reference value Vth), the end of prohibition of calibration may be determined.

  In the above embodiment, while calibration is prohibited, the latest zero point correction amount Yrcalib calculated immediately before the start of prohibition of the calibration is subtracted from the current detected yaw rate Yr as a temporary zero point correction amount. Is configured to correct the detected yaw rate Yr, but instead of the latest zero point correction amount Yrcalib, the design zero point correction amount (constant value) and the current zero point correction amount The detected yaw rate Yr may be corrected by subtracting one of the stored values Yrmemory from the current detected yaw rate Yr.

  In the above embodiment, at the time when the prohibition of calibration is canceled, the latest zero point correction amount Yrcalib calculated immediately before the start of prohibition of the calibration is used as a temporary zero point correction amount from the currently detected yaw rate Yr. It is configured to correct the detected yaw rate Yr by subtracting, but instead of the latest zero point correction amount Yrcalib, the design zero point correction amount (constant value), the current zero point correction amount The detected yaw rate Yr may be corrected by subtracting one of the stored value Yrmemory and the current detected yaw rate Yr itself from the current detected yaw rate Yr.

  Further, in the above embodiment, when calibration is invalidated, the current zero point correction amount storage value Yrmemory at the present time (and hence IG: at the time of ON) is detected as a temporary zero point correction amount at the present time. Although it is configured to correct the detected yaw rate Yr by subtracting from the yaw rate Yr (see step 450), instead of the zero point correction amount storage value Yrmemory, a design zero point correction amount (a constant value) Also, the detected yaw rate Yr may be corrected by subtracting any of the current detected yaw rate Yr itself from the current detected yaw rate Yr.

  Further, in the above embodiment, after IG: ON, once it is determined (by one calculation of the CPU 51) that the estimated vehicle speed Vso is greater than the stop state determination reference value Vth, “IG: ON The value of the travel flag RUN is set to “1” as “the vehicle has traveled after that time” (see step 428), but the estimated vehicle body continues for a predetermined time (successively several times in the calculation of the CPU 51). When it is determined that the speed Vso is larger than the stop state determination reference value Vth, the value of the travel flag RUN is set to “1” as “IG: There is a background of the vehicle traveling after the time of ON”. May be.

  Further, in the above embodiment, when the vehicle is in a traveling state and is traveling straight, the zero point correction amount Yrcalib is updated every execution cycle of the routine of FIG. 4 (the calculation cycle of the CPU 51). (Accordingly, the calibration of the detected yaw rate Yr) is executed (see step 422), but every time the vehicle is in a traveling state and continues straight for a predetermined time (ie, step 416). And every time the condition of Step 430 is continuously established a predetermined number of times), the zero point correction amount Yrcalib may be updated (and hence the detected yaw rate Yr is calibrated).

  In the above embodiment, the yaw rate is adopted as the angular velocity related to the behavior of the vehicle body. However, for example, a pitch rate or a roll rate may be adopted.

1 is a schematic configuration diagram of a vehicle equipped with a vehicle motion control device including a vehicle angular velocity detection device according to an embodiment of the present invention. When the vehicle shown in FIG. 1 enters the turntable, stops on the turntable at time t0, and then remains in the stopped state with IG: ON, It is the time chart which showed an example of the change of the change speed of a detection yaw rate. Detected yaw rate and the same detection in the case where the vehicle shown in FIG. 1 is turned on at time t10 (or time t10 ′) on the turntable, and then maintained in a stopped state with IG: ON. It is the time chart which showed an example of the change of the change rate of a yaw rate. 3 is a flowchart showing a routine for calculating a post-calibration yaw rate executed by a CPU shown in FIG. 1. 3 is a flowchart showing a routine for calculating a zero point correction amount storage value executed by a CPU shown in FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 30 ... Brake hydraulic pressure control device, 41 ** ... Wheel speed sensor, 42 ... Steering angle sensor, 43 ... Yaw rate sensor, 50 ... Electric control device, 51 ... CPU, 54 ... Backup RAM

Claims (10)

Vehicle body speed acquisition means for acquiring a vehicle body speed;
Angular velocity detection means for detecting an angular velocity related to the behavior of the vehicle body as a detected angular velocity;
Stop state determination means for determining whether or not the vehicle is in a stop state based on the acquired vehicle body speed;
When it is determined that at least the vehicle is in a stopped state, a zero point correction amount for making the value of the detected angular velocity detected by the angular velocity detection means zero is obtained, and based on the zero point correction amount, the same value is obtained. Detection angular velocity calibration means for calibrating the value of the detection angular velocity;
A vehicle angular velocity detection device comprising:
When the state of the vehicle is maintained in the stopped state after shifting from the running state to the stopped state, and the change rate of the detected angular velocity is equal to or greater than a predetermined prohibition change rate threshold, An angular velocity detection device for a vehicle comprising calibration prohibiting means for prohibiting the calibration by the detected angular velocity calibration means. Vehicle body speed acquisition means for acquiring a vehicle body speed;
Angular velocity detection means for detecting an angular velocity related to the behavior of the vehicle body as a detected angular velocity;
Stop state determination means for determining whether or not the vehicle is in a stop state based on the acquired vehicle body speed;
When it is determined that at least the vehicle is in a stopped state, a zero point correction amount for making the value of the detected angular velocity detected by the angular velocity detection means zero is obtained, and based on the zero point correction amount, the same value is obtained. Detection angular velocity calibration means for calibrating the value of the detection angular velocity;
A vehicle angular velocity detection device comprising:
Angle acquisition means for acquiring an angle related to the behavior of the vehicle body and corresponding to the angular velocity;
When the vehicle state is maintained in the stopped state after shifting from the running state to the stopped state, and when the vehicle state shifts to the stopped state at the acquired angle. Calibration prohibiting means for prohibiting the calibration by the detected angular velocity calibration means when the amount of change from the angle acquired in (1) is equal to or greater than a predetermined prohibition angle threshold;
An angular velocity detection device for a vehicle comprising: The angular velocity detection device for a vehicle according to claim 2,
The calibration prohibition means includes
The amount of change from the angle acquired when a predetermined time elapses from the time when the vehicle state transitions to the stop state from the angle acquired when the vehicle state transitions to the stop state is An angular velocity detection device for a vehicle configured to prohibit the calibration by the detected angular velocity calibration means when a prohibition angle threshold is exceeded. The vehicle angular velocity detection device according to any one of claims 1 to 3,
The detected angular velocity calibration means includes
While the calibration is prohibited by the calibration prohibiting means, a predetermined design value for the zero point correction amount, the latest zero point correction amount obtained when the calibration is prohibited, and the One of the values based on the zero point correction amount already obtained when calibration is prohibited and stored in a predetermined storage means is set as a temporary zero point correction amount. An angular velocity detection apparatus for a vehicle configured to correct a value of the detected angular velocity detected by the angular velocity detection means based on a temporary zero point correction amount. The vehicle angular velocity detection device according to any one of claims 1 to 4,
When the calibration is prohibited by the calibration prohibition means and the change rate of the detected angular velocity is equal to or greater than a predetermined prohibition release change speed threshold, the calibration prohibition cancels the calibration prohibition by the calibration prohibition means. An angular velocity detection device for a vehicle, further comprising release means. The angular velocity detection device for a vehicle according to claim 5,
The calibration prohibition release means includes
After the change speed of the detected angular velocity becomes equal to or higher than the prohibition release change speed threshold, the change speed of the detected angular velocity changes from a value equal to or higher than the prohibition release change speed threshold to a value less than the prohibition release change speed threshold. An angular velocity detection device for a vehicle configured to release the prohibition of the calibration by the calibration prohibiting means after the time. The vehicle angular velocity detection device according to any one of claims 1 to 4,
A calibration prohibition release means for canceling the prohibition of calibration by the calibration prohibition means when the calibration is prohibited by the calibration prohibition means and the vehicle body speed exceeds a predetermined prohibition release speed threshold value; A vehicle angular velocity detection device provided. The angular velocity detection device for a vehicle according to any one of claims 5 to 7,
The detected angular velocity calibration means includes:
When the prohibition of calibration is canceled by the calibration prohibition canceling means, a predetermined design value for the zero point correction amount, and the latest zero point correction amount obtained when the calibration is prohibited , A value based on the zero point correction amount already obtained when the calibration is prohibited and a value stored in a predetermined storage means, and the angular velocity detection when the prohibition of the calibration is released One of the detected angular velocities detected by the means is set as a temporary zero point correction amount, and the angular velocity of the vehicle is configured to correct the value of the detected angular velocity based on the temporary zero point correction amount. Detection device. Vehicle body speed acquisition means for acquiring a vehicle body speed;
Angular velocity detection means for detecting an angular velocity related to the behavior of the vehicle body as a detected angular velocity;
Stop state determination means for determining whether or not the vehicle is in a stop state based on the acquired vehicle body speed;
When it is determined that at least the vehicle is in a stopped state, a zero point correction amount for making the detected angular velocity value detected by the angular velocity detection means zero is obtained, and the detection is performed based on the zero point correction amount. Detection angular velocity calibration means for calibrating the angular velocity value;
A vehicle angular velocity detection device comprising:
After the time when the ignition switch is changed from the off state to the on state, the state of the vehicle is maintained in the stop state, and the change speed of the detected angular velocity becomes equal to or greater than a predetermined invalidation change speed threshold. In this case, the vehicle angular velocity detection device includes calibration invalidation means for invalidating the calibration already performed by the detection angular velocity calibration means. The vehicle angular velocity detection device according to claim 9,
The detected angular velocity calibration means includes
When the calibration is invalidated by the calibration invalidation means, a predetermined design value for the zero point correction amount, and by a predetermined storage means when the ignition switch is changed from the off state to the on state One of the value based on the stored zero point correction amount and the detected angular velocity detected by the angular velocity detection means at the time when the calibration is invalidated is set as a temporary zero point correction amount, An angular velocity detection device for a vehicle configured to correct the value of the detected angular velocity based on the provisional zero point correction amount.

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