JP2009192251A - Device and method for determining abnormality - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device and a method for determining abnormality which are capable of improving the reliability of the result of determination as to whether or not there is a sensor showing the abnormality among various sensors carried by a vehicle. <P>SOLUTION: ECU calculates a real yaw rate, based on an output signal from a yaw rate sensor, and also a rudder-angle-converted yaw rate, based on an output signal from a steering angle sensor, and moreover calculates a lateral-G-converted yaw rate, based on an output signal from a lateral direction acceleration sensor. Then, the ECU calculates three yaw differences SY1, SY2 and SY3 (step S25), using each yaw rate at the timing of a turning end (affirmative determination at step S21). Next, the ECU determines that a skid of a vehicle body occurs at the time of turning of the vehicle, in the case when at least one of the yaw differences SY1, SY2 and SY3 is a yaw difference threshold KSY or above (negative determination at step S26), and regulates execution of an abnormality determination processing (step S27). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an abnormality determination device and an abnormality determination method for determining whether or not there is a sensor indicating abnormality among various sensors for detecting a behavior state of a vehicle during traveling.

  In general, a vehicle is equipped with a braking device that can individually apply a braking force to each wheel. Such a braking device operates according to vehicle state values (yaw rate, lateral acceleration, steering angle of steering, etc.) calculated based on output signals output from the yaw rate sensor, lateral acceleration sensor, and steering angle sensor. This is intended to stabilize the running state of the vehicle.

  By the way, the braking device operates on the assumption that each vehicle state value calculated based on output signals output from various sensors is accurate. Therefore, when an abnormality such as a failure occurs in at least one of the various sensors, the operation of the braking device may be hindered. Therefore, as a braking control device that controls the operation of the braking device, a braking control device having a failure diagnosis (fail-safe) function of various sensors mounted on the vehicle has been conventionally known.

Such a braking control device calculates the actual yaw rate based on the output signal output from the yaw rate sensor, calculates the first estimated yaw rate based on the output signal output from the lateral acceleration, and further from the steering angle sensor. A second estimated yaw rate is calculated based on the output signal output. Subsequently, the braking control device calculates a first gain of the first estimated yaw rate with respect to the actual yaw rate, a second gain of the second estimated yaw rate with respect to the actual yaw rate, and a third gain of the second estimated yaw rate with respect to the first estimated gain. And the brake control apparatus specified the sensor which shows abnormality from various sensors by performing the abnormality determination process which compares the variation | change_quantity of each gain at the time of turning of a vehicle (for example, refer patent document 1).
JP 2000-55933 A

  By the way, the output signal output from the yaw rate sensor indicates the actual yaw rate (speed at which the vehicle rotates) even if a side slip of the vehicle body occurs when the vehicle turns. On the other hand, each estimated yaw rate based on the output signals output from the lateral acceleration sensor and the steering angle sensor is an estimated value calculated on the assumption that the vehicle body does not skid. The value deviates from the value (that is, the actual yaw rate). For this reason, even if the abnormality determination process is executed when the vehicle slips, the result that one yaw rate (for example, the actual yaw rate) is different from the other yaw rate (for example, each estimated yaw rate) ) Is really abnormal, or because there is no abnormality in one sensor (eg, yaw rate sensor) itself, and each estimated yaw rate has deviated from the actual yaw rate due to the side slip of the vehicle body. I couldn't determine if it was.

  The present invention has been made in view of such circumstances, and an object thereof is to improve the reliability of the determination result as to whether or not there is a sensor indicating abnormality among various sensors mounted on the vehicle. It is an object to provide an abnormality determination device and an abnormality determination method capable of performing the above.

  In order to achieve the above-mentioned object, the invention according to claim 1 according to the abnormality determination device is provided with a plurality of types for detecting the turning state of the vehicle as a turning state value (YR, Yst, Ygy) when the vehicle turns. An abnormality determination device (12) that executes an abnormality determination process (S28) for determining whether or not there is a sensor indicating abnormality among the sensors (SE1 to SE4, SE5, SE6, SE7), A yaw rate sensor (SE5) for detecting the actual yaw rate (YR) of the vehicle as a turning state value, and other sensors (SE1 to SE4, SE6, SE7) different from the yaw rate sensor (SE5) The turning state value (YR) is mounted on the basis of output signals output from the yaw rate sensor (SE5) and the other sensors (SE1 to SE4, SE6, SE7). Yst, Ygy) are calculated by the state value calculation means (12, S10, S11, S12) and the state value calculation means (12, S10, S11, S12) at the timing when the vehicle turns. A side slip determining means (12, S26) for determining whether or not a side slip of the vehicle body has occurred at the time of turning of the vehicle based on the comparison result of each turning state value (YR, Yst, Ygy), and at the end of the turning An execution restriction means (12, S28) for restricting the execution of the abnormality determination process (S27) when the side slip determination means (12, S26) determines that a side slip has occurred when the vehicle is turning. Is the gist.

  According to the above configuration, when it is determined that a side slip of the vehicle body has not occurred during turning of the vehicle, the abnormality determination process using each turning state value based on the output signal from each sensor including the yaw rate sensor is performed. Executed. On the other hand, if it is determined that a side slip of the vehicle body has occurred when the vehicle is turning, the turning state value based on the other sensor deviates from the turning state value based on the yaw rate sensor even if there is no abnormal sensor. There is a possibility. Therefore, the execution of the abnormality determination process using each turning state value is restricted. Therefore, it is possible to improve the reliability of the determination result as to whether or not there is a sensor indicating abnormality among the various sensors mounted on the vehicle.

  According to a second aspect of the present invention, in the abnormality determination device according to the first aspect, the vehicle includes the yaw rate sensor (SE5), and sensors (SE1 to SE4) for detecting a turning state of the turning vehicle. , SE5, SE6, SE7) are provided, and the state value calculation means (12, S10, S11, S12) are output from the sensors (SE1 to SE4, SE5, SE6, SE7). The gist is to calculate three or more turning state values (YR, Yst, Ygy) based on the output signal.

  According to the above configuration, since three or more turning state values are calculated, it is specified which of the sensors is abnormal by executing the abnormality determination process using each of the turning state values. .

  According to a third aspect of the present invention, in the abnormality determination device according to the second aspect, the turning state values (YR, Y) calculated by the state value calculating means (12, S10, S11, S12) when the vehicle turns. Yst, Ygy) is further provided with a turning side slip judging means (12, S19) for judging whether or not a side slip of the vehicle body has occurred, and the execution restricting means (12, S28) The gist of the invention is to restrict the execution of the abnormality determination process (S27) when it is determined by the side slip determination means (12, S19) during turning that the vehicle body is skidding.

  According to the above configuration, it is not only determined whether or not a side slip of the vehicle body has occurred at the time of turning of the vehicle based on each turning state value calculated at the timing when the turning of the vehicle is finished, but is also calculated during turning of the vehicle. It is determined whether or not the vehicle body is skidding based on each turning state value. Therefore, it is possible to detect the side slip of the vehicle body when the vehicle is turning with a higher probability. Therefore, the reliability of the determination result by the abnormality determination process can be further improved.

  According to a fourth aspect of the present invention, in the abnormality determination device according to any one of the first to third aspects, the respective state values calculated by the state value calculating means (12, S10, S11, S12). Straight travel in which it is determined that the vehicle has traveled straight when the turning state values (YR, Yst, Ygy) are less than a straight travel threshold (KYT1) set in advance as a reference value for determining whether the vehicle travels straight. The execution restricting means (12, S28) is further provided with a determining means (12, S13). When the straight traveling determining means (12, S13) determines that the vehicle is inexperienced in straight traveling, the execution restricting means (12, S13) The gist is to restrict the execution of the abnormality determination process (S27) even at the timing when the turning of the vehicle is completed.

  According to the above configuration, when at least one turning state value among the turning state values when the vehicle is traveling straight is greater than or equal to the straight traveling threshold value, it is necessary to calculate the at least one turning state value. Since there is a possibility that the sensor is inconvenient (such as an offset in the input signal from the sensor), the subsequent execution of the abnormality determination process is restricted. On the other hand, it is possible to further improve the reliability of the abnormality determination process by executing the abnormality determination process after it is determined that the vehicle has traveled straight due to each turning state value being less than the straight travel threshold value. .

  On the other hand, the invention according to claim 5 related to the abnormality determination method is a plurality of types of sensors (SE1 to SE4) for detecting the turning state of the vehicle as a turning state value (YR, Yst, Ygy) when the vehicle turns. An abnormality determination method for executing an abnormality determination process (S27) for determining whether there is a sensor indicating an abnormality in SE5, SE6, SE7), wherein the vehicle includes an actual yaw rate (YR) of the vehicle Is installed as a yaw rate sensor (SE5) for detecting a turning state value and other types of sensors (SE1 to SE4, SE6, SE7) different from the yaw rate sensor (SE5). Based on the output signals output from SE5) and the other sensors (SE1 to SE4, SE6, SE7), a plurality of the turning state values (YR, Yst, Ygy) are calculated. State value calculating steps (S10, S11, S12) and the respective turning state values (YR, Yst) calculated in the state value calculating steps (S10, S11, S12) executed at the timing when the turning of the vehicle is completed. , Ygy) based on the comparison result, when it is determined whether or not a side slip of the vehicle body has occurred when the vehicle is turning, a side slip determination step at the end of the turn (S26) and a side slip determination step at the end of the turn (S26). The present invention includes an execution restriction step (S28) for restricting execution of the abnormality determination process (S27) when it is determined that a side slip of the vehicle body has occurred during turning of the vehicle.

  According to the said structure, the effect equivalent to the invention of Claim 1 can be acquired.

  Hereinafter, an embodiment embodying the abnormality determination device and abnormality determination method of the present invention will be described with reference to FIGS. In the following description of the present specification, the traveling direction (forward direction) of the vehicle is assumed to be the front (front of the vehicle). Unless otherwise specified, the left-right direction in the following description is the same as the left-right direction in the vehicle traveling direction.

  As shown in FIG. 1, the braking device 11 of the present embodiment is applied to a vehicle having a plurality of (four in the present embodiment) wheels (a right front wheel FR, a left front wheel FL, a right rear wheel RR, and a left rear wheel RL). It is mounted and configured to be able to individually apply braking force to each wheel FR, FL, RR, RL. The operation of the braking device 11 is controlled by an electronic control device (hereinafter referred to as “ECU”) 12 as an abnormality determination device.

  An input side interface (not shown) of the ECU 12 detects wheel speed sensors SE1, SE2, SE3, SE4 for detecting the wheel speeds of the wheels FR, FL, RR, RL, and a yaw rate of the vehicle. A yaw rate sensor SE5 is electrically connected. Further, an input side interface of the ECU 12 includes a steering angle sensor SE6 for detecting a steering angle of a steering wheel (not shown) and a lateral acceleration for detecting a lateral acceleration (also referred to as “lateral G”) of the vehicle. A sensor (also referred to as “lateral G sensor”) SE7 is electrically connected. The yaw rate sensor SE5, the steering angle sensor SE6, and the lateral acceleration sensor SE7 each output an output signal corresponding to a positive value while the vehicle is turning to the left, while being negative while the vehicle is turning to the right. Each output signal corresponding to a value is output.

  The braking device 11 is electrically connected to an output side interface (not shown) of the ECU 12. And ECU12 controls operation | movement of the braking device 11 based on each output signal output from various sensors SE1-SE7.

  The ECU 12 is provided with a CPU 13, a ROM 14 and a RAM 15. The ROM 14 stores various control processes (such as sensor abnormality determination process described later) and various thresholds (a turning threshold, a lower threshold, an upper threshold, a turning time threshold, a yaw difference threshold, a first straight traveling determination threshold, and a second straight traveling determination described later). Threshold, determination lower limit, determination upper limit, counter threshold, etc.) are stored in advance. Further, the RAM 15 stores various information (an actual yaw rate, a rudder angle converted yaw rate, a lateral G converted yaw rate, an actual yaw rate integral value, an actual yaw rate integrated value, a rudder angle converted yaw rate, which will be described later) while an ignition switch (not shown) of the vehicle is “ON”. Integral value, lateral G-converted yaw rate integral value, first gain, second gain, third gain, first yaw difference, second yaw difference, third yaw difference, turn time, rectilinear counter, rectilinear determination flag, etc.) are temporarily Remembered.

  Next, a sensor abnormality determination processing routine for determining whether or not the yaw rate sensor SE5 is abnormal among the control processes executed by the ECU 12 of the present embodiment is shown in the flowcharts of FIGS. And it demonstrates based on the timing chart shown in FIG.

  The ECU 12 executes the sensor abnormality determination processing routine at predetermined intervals (in this embodiment, “every 0.01 seconds”). In this sensor abnormality determination processing routine, the ECU 12 calculates the actual yaw rate YR of the vehicle based on the output signal output from the yaw rate sensor SE5 (step S10). The yaw rate sensor SE5 is a dedicated sensor for detecting the yaw rate of the vehicle. Therefore, the actual yaw rate YR is an almost accurate value regardless of whether or not the vehicle body is skidding when the vehicle is turning unless the yaw rate sensor SE5 is abnormal. In the present embodiment, the term “side slip of the vehicle body” refers to a skid of a magnitude such that the behavior of the turning vehicle becomes unstable, and “when a side slip of the vehicle body occurs during the turning of the vehicle. “Can be paraphrased as“ when the behavior of the turning vehicle becomes unstable ”. In addition, “when no side slip of the vehicle body occurs during turning of the vehicle” can be restated as “when the behavior of the turning vehicle is stable”.

  Subsequently, the ECU 12 calculates a steering angle of a steering wheel (not shown) based on an output signal output from the steering angle sensor SE6. Then, the ECU 12 calculates the steering angle converted yaw rate Yst using the following relational expression (formula 1) (step S11). The rudder angle converted yaw rate Yst is an estimated value calculated assuming that the side slip of the vehicle body has not occurred, that is, the behavior of the vehicle is in a stable state.

ただし、Ｙｓｔ…舵角換算ヨーレート、ｎ…ステアリングホイールのギヤ比、Ｌ…車両のホイールベース長、Ｖ…車両の車体速度、θ…ステアリングホイールの操舵角、Ａ…スタビリティファクタ
続いて、ＥＣＵ１２は、横方向加速度センサＳＥ７から出力された出力信号に基づき車両の横方向加速度を演算する。そして、ＥＣＵ１２は、以下に示す関係式（式２）を用い、横Ｇ換算ヨーレートＹｇｙを演算する（ステップＳ１２）。なお、この横Ｇ換算ヨーレートＹｇｙは、車体の横滑りが発生していない状態、即ち、車両の挙動が安定状態であるものとして演算した推定値である。

However, Yst ... steering angle conversion yaw rate, n ... steering wheel gear ratio, L ... vehicle wheel base length, V ... vehicle body speed, .theta .... steering wheel steering angle, A ... stability factor. The lateral acceleration of the vehicle is calculated based on the output signal output from the lateral acceleration sensor SE7. Then, the ECU 12 calculates the lateral G-converted yaw rate Ygy using the following relational expression (formula 2) (step S12). Note that the lateral G-converted yaw rate Ygy is an estimated value calculated assuming that the side slip of the vehicle body has not occurred, that is, the behavior of the vehicle is in a stable state.

ただし、Ｙｇｙ…横Ｇ換算ヨーレート、Ｇｙ…横方向加速度、Ｖ…車両の車体速度
したがって、本実施形態では、ＥＣＵ１２が、車両の旋回状態を示す旋回状態値として複数（３つ）のヨーレートＹＲ，Ｙｓｔ，Ｙｇｙを演算する状態値演算手段としても機能する。また、ステップＳ１０，Ｓ１１，Ｓ１２が、状態値演算ステップに相当する。なお、上記各関係式（式１）（式２）で用いられる車両の車体速度「Ｖ」は、各車輪速度センサＳＥ１〜ＳＥ４から出力された各出力信号に基づき演算された各車輪ＦＲ，ＦＬ，ＲＲ，ＲＬの車輪速度を用いて演算される。

However, Ygy: lateral G converted yaw rate, Gy: lateral acceleration, V: vehicle body speed Therefore, in this embodiment, the ECU 12 has a plurality of (three) yaw rates YR, Y as the turning state values indicating the turning state of the vehicle. It also functions as a state value calculation means for calculating Yst and Ygy. Steps S10, S11, and S12 correspond to state value calculation steps. The vehicle body speed “V” used in each of the relational expressions (Expression 1) and (Expression 2) is calculated based on the output signals output from the wheel speed sensors SE1 to SE4. , RR, and RL are used for calculation.

  Subsequently, the ECU 12 executes a straight traveling experience determination process detailed in FIG. 4 (step S13). In this straight travel experience determination process, when it is detected that the vehicle has traveled straight for a predetermined time (eg, “1 second”), it is determined whether or not the vehicle has experienced straight travel. The straight traveling determination flag FLG1 is set to “1”. Therefore, in this respect, in this embodiment, the ECU 12 also functions as a straight traveling determination unit. Then, the ECU 12 determines whether or not the straight traveling determination flag FLG1 is “1” (step S14). If this determination process is a negative determination (FLG1 = "0"), the ECU 12 once ends the sensor abnormality determination process routine.

  On the other hand, if the determination result in step S14 is affirmative (FLG1 = "1"), the ECU 12 determines that the vehicle has experienced straight travel, and the absolute value of the steering angle converted yaw rate Yst calculated in step S11. Whether or not exceeds a preset turning threshold value KY1 (step S15). This turning threshold value KY1 is a value (for example, “9 deg / s (degrees / second)”) for determining whether or not the vehicle is turning, and is set in advance by experiments or simulations.

  If the determination result in step S15 is negative (Yst absolute value ≦ KY1), the ECU 12 proceeds to step S19 described later. On the other hand, if the determination result in step S15 is affirmative (Yst absolute value> KY1), the ECU 12 determines that the vehicle is turning. That is, as shown in the timing chart of FIG. 7, the first timing t1 when the absolute value of the steering angle converted yaw rate Yst exceeds the turning threshold value KY1 is the timing when the turning of the vehicle is started. 2 and 3, the ECU 12 updates the turning time T1, which is an elapsed time from the start of turning (that is, adds “0.01 seconds” that is the predetermined interval) (step S16).

  Subsequently, the ECU 12 integrates the actual yaw rate YR calculated in step S10, and updates the actual yaw rate integrated value YR_I. Further, the ECU 12 integrates the rudder angle conversion yaw rate Yst calculated in step S11, and updates the rudder angle yaw rate integrated value Yst_I. Further, the ECU 12 integrates the lateral G-converted yaw rate Ygy calculated in step S12, and updates the lateral G-converted yaw rate integrated value Ygy_I (step S17). These yaw rate integral values YR_I, Yst_I, and Ygy_I are the sum totals of the integral values of the yaw rates YR, Yst, and Ygy that have been calculated since the vehicle started turning.

  Then, the ECU 12 calculates a first gain G1 (= YR_I / Yst_I) of the actual yaw rate integrated value YR_I with respect to the steering angle yaw rate integrated value Yst_I. Further, the ECU 12 calculates a second gain G2 (= YR_I / Ygy_I) of the actual yaw rate integrated value YR_I with respect to the lateral G-converted yaw rate integrated value Ygy_I. Further, the ECU 12 calculates a third gain G3 (= Yst_I / Ygy_I) of the steering angle yaw rate integrated value Yst_I with respect to the lateral G-converted yaw rate integrated value Ygy_I (step S18), and thereafter the process proceeds to step S19 described later. .

  In step S19, the ECU 12 determines that the third gain G3 calculated in step S18 is greater than or equal to a preset lower limit threshold value KGmin (eg, “70%”) and a preset upper limit threshold value KGmax (eg, “130%”). ]) It is determined whether or not the following. Each of these threshold values KGmin and KGmax is a value for determining whether or not a side slip of the vehicle body occurs when the vehicle turns, and is set in advance through experiments, simulations, or the like. In other words, the rudder angle converted yaw rate Yst and the lateral G converted yaw rate Ygy are estimated values based on the assumption that no side slip of the vehicle body has occurred, and therefore when the vehicle side slip occurs during turning of the vehicle, the actual yaw rate ( That is, the value greatly deviates from the actual yaw rate YR). For this reason, when the side slip of the vehicle body occurs, the third gain G3 becomes a value larger or smaller than “100%”. Therefore, in this embodiment, in this embodiment, the ECU 12 also functions as a side slip determination means during turning.

  If the determination result in step S19 is negative (G3 <KGmin or KGmax <G3), the ECU 12 determines that the vehicle is skidding, and the process proceeds to step S28 described later. On the other hand, if the determination result in step S19 is affirmative (KGmin ≦ G3 ≦ KGmax), the ECU 12 determines whether or not the vehicle has finished turning, that is, whether or not the turn has ended (step S21). Specifically, as shown in the timing charts of FIGS. 7 and 8, when the second timing t2 at which the sign of the steering angle conversion yaw rate Yst calculated in step S11 has changed is reached, the turn is completed. It is determined that it is time.

  2 and 3, if the determination result in step S21 is negative, the ECU 12 determines that the vehicle is still turning, that is, has not yet reached the second timing t2, and sensor abnormality determination The processing routine is temporarily terminated. On the other hand, if the determination result in step S21 is affirmative, that is, if the sign of the previous rudder angle converted yaw rate Yst and the current rudder angle converted yaw rate Yst is switched, the ECU 12 determines that the turn end timing has come, The straight traveling determination flag FLG1 is set to “0 (zero)” (step S22). Subsequently, the ECU 12 determines whether or not the absolute value of the maximum value Yst_max of each steering angle conversion yaw rate Yst calculated when the vehicle is turning is greater than a preset maximum turning threshold KYmax (step S23). When the absolute value of each yaw rate YR, Yst, Ygy is small, the ratio of error components included in each yaw rate YR, Yst, Ygy may increase. When abnormality determination processing described later is performed using such yaw rates YR, Yst, and Ygy, there is a risk of erroneous determination. Therefore, the maximum turning threshold value KYmax is set in advance so that the ratio of error components included in each yaw rate YR, Yst, Ygy falls within an allowable range.

  When the determination result of step S23 is negative (absolute value of Yst_max ≦ KYmax), the ECU 12 proceeds to step S28 described later. On the other hand, when the determination result in step S23 is affirmative (absolute value of Yst_max> KYmax), the ECU 12 sets a turning time threshold value KT1 (for example, “3 seconds”) in which the turning time T1 updated in step S16 is set in advance. ) It is determined whether or not the above is satisfied (step S24). This turning time threshold value KT1 is a value for preventing the abnormality determination process described later from being executed when the steering wheel steering by the driver is instantaneous steering for adjusting the behavior of the vehicle. It is set in advance by experiments or simulations.

  If the determination result in step S24 is negative (T1 <KT1), the ECU 12 determines that the turning time T1 is short, and the process proceeds to step S28 described later. On the other hand, when the determination result of step S24 is affirmative (T1 ≧ KT1), the ECU 12 calculates a first yaw difference SY1 that is a difference between the actual yaw rate YR and the steering angle conversion yaw rate Yst. Further, the ECU 12 calculates a second yaw difference SY2 that is a difference between the lateral G-converted yaw rate Ygy and the actual yaw rate YR, and a third yaw difference SY3 that is a difference between the lateral G-converted yaw rate Ygy and the steering angle-converted yaw rate Yst. (Step S25).

  Subsequently, the ECU 12 determines whether or not each yaw difference SY1, SY2, SY3 calculated in step S25 is less than a preset yaw difference threshold value KSY (for example, “3 deg / s (degrees / second)”). (Step S26). When the vehicle body is still skidding at the end of the turn, the steering angle converted yaw rate Yst and the lateral G converted yaw rate Ygy are values that deviate from the actual yaw rate YR. Therefore, the yaw differences SY1, SY2, and SY3 have deviations (variations). ) Occurs. Using the occurrence of such deviations of the yaw differences SY1, SY2, SY3, in step S26, when at least one of the yaw differences SY1, SY2, SY3 is equal to or greater than the yaw difference threshold value KSY, It is determined that a side slip occurred. In this regard, in the present embodiment, the ECU 12 also functions as a skid determination unit at the end of turning.

  If the determination result in step S26 is negative (at least one of SY1, SY2, SY3 ≧ KSY), the ECU 12 proceeds to step S28 described later without executing the abnormality determination processing described later. . On the other hand, when the determination result of step S26 is affirmative (SY1, SY2, SY3 <KSY), the ECU 12 executes an abnormality determination process detailed in FIG. 5 (step S27). In this abnormality determination process, it is determined whether or not there is a sensor indicating an abnormality due to a cause such as a failure. Then, the ECU 12 proceeds to the next step S28. “Sensor abnormality” means abnormality of the sensor itself (failure, etc.), abnormality of wiring that electrically connects the sensor and the ECU 12 (short circuit, etc.), and an amplification circuit (not shown) that amplifies the output signal from the sensor. ) Abnormalities (failures, etc.).

  In step S <b> 28, the ECU 12 executes a reset process that will be described in detail with reference to FIG. 6, and then ends the sensor abnormality determination process routine. Note that if step S28 is executed because the determination results in steps S14, S19, S24, and S26 are negative, at the end of the current turn, a side slip of the vehicle body has occurred, or straight running is inexperienced. Therefore, the execution of the abnormality determination process (step S27) is restricted. Therefore, in this respect, in this embodiment, the ECU 12 also functions as an execution restricting unit. Step S28 corresponds to an execution regulation step.

Next, the straight traveling experience determination processing (straight traveling experience determination processing routine) in step S13 will be described based on the flowchart shown in FIG.
In the straight travel experience determination processing routine, the ECU 12 determines whether or not the straight travel determination flag FLG1 is “0 (zero)” (step S30). If this determination result is a negative determination (FLG1 = "1"), the ECU 12 determines that the vehicle has already experienced a straight travel, and ends the straight travel experience determination processing routine. On the other hand, if the determination result in step S30 is affirmative (FLG1 = “0”), the ECU 12 sets all yaw rates YR, Yst, Ygy calculated in steps S10 to S12 as the straight advance threshold values set in advance. It is determined whether or not it is less than one straight-running determination threshold KYT1 (for example, “3 deg / s (degrees / second)”) (step S31). The first straight travel determination threshold value KYT1 is a value for determining whether or not the vehicle is traveling straight ahead from the yaw rates YR, Yst, and Ygy of the vehicle, and is set in advance by experiments or simulations.

  If the determination result in step S31 is a negative determination (at least one of YR, Yst, Ygy ≧ KYT1), the ECU 12 proceeds to step S35 to be described later. On the other hand, if the determination result in step S31 is affirmative (YR, Yst, Ygy <KYT1), the ECU 12 calculates the yaw differences SY1, SY2, SY3 as in step S26 (step S32). Subsequently, the ECU 12 determines whether or not all yaw differences SY1, SY2, SY3 calculated in step S32 are less than a preset second straight travel determination threshold value KYT2 (for example, “3 deg / s (degrees / second)”). Is determined (step S33). The second straight travel determination threshold value KYT2 is a value for determining that the deviation of each yaw rate YR, Yst, Ygy when the vehicle travels straight is small, and is set in advance through experiments, simulations, or the like.

  If the determination result in step S33 is affirmative (SY1, SY2, SY3 <KYT2), the ECU 12 increments the straight-ahead counter SC by “1” (step S331). Subsequently, the ECU 12 determines whether or not the rectilinear counter SC incremented in step S331 has exceeded a preset counter threshold KSC (step S332). The counter threshold value KSC is set in advance to such a value that it is determined that the vehicle has experienced a straight traveling when the straight traveling is continued for a predetermined time. Therefore, it is not determined that the vehicle has traveled straight if the conditions for the determination processes in steps S31 and S33 are satisfied for a moment. If the determination result of step S332 is negative (SC ≦ KSC), the ECU 12 ends the straight traveling experience determination processing routine. On the other hand, if the determination result in step S33 is affirmative (SC> KSC), the ECU 12 determines that the vehicle is traveling straight ahead, sets the straight travel determination flag FLG1 to “1” (step S34), and then Then, the straight traveling experience determination processing routine is terminated.

In step S35, the ECU 12 resets the straight travel counter SC to “0 (zero)”, and then ends the straight travel experience determination processing routine.
Next, the abnormality determination processing (abnormality determination processing routine) in step S27 will be described based on the flowchart shown in FIG.

  In the abnormality determination processing routine, the ECU 12 determines whether or not both the first gain G1 and the second gain G2 calculated in step S18 are equal to or less than a predetermined determination lower limit value Kmin (for example, “70%”). Is determined (step S40). This determination lower limit value Kmin is a value for determining whether or not the yaw rate sensor SE5 has an abnormality based on the magnitudes of the first gain G1 and the second gain G2, and is set in advance through experiments, simulations, or the like. .

  If the determination result in step S40 is affirmative (G1, G2 ≦ Kmin), the ECU 12 determines that the yaw rate sensor SE5 is abnormal (step S41), and then ends the abnormality determination processing routine. On the other hand, when the determination result in step S40 is negative (at least one of G1 and G2> Kmin), the ECU 12 determines the determination upper limit value Kmax (for example, “ 130% ") or more (step S42). This determination upper limit value Kmax is a value for determining whether or not the yaw rate sensor SE5 has an abnormality based on the magnitudes of the first gain G1 and the second gain G2, and is set in advance through experiments or simulations. .

  If the determination result of step S42 is affirmative (G1, G2 ≧ Kmax), the ECU 12 executes the process of step S41 described above, and then ends the abnormality determination process routine. On the other hand, if the determination result of step S42 is negative (at least one of G1 and G2 <Kmax), the ECU 12 determines that the yaw rate sensor SE5 is normal and ends the abnormality determination processing routine.

Finally, the reset process (reset process routine) in step S28 will be described based on the flowchart shown in FIG.
In the reset processing routine, the ECU 12 resets the straight traveling determination flag FLG1 to “0 (zero)” and resets the turning time T1 to “0 (zero)”. Further, the yaw rate integrated values YR_I, Yst_I, Ygy_I is reset to “0 (zero)”. The ECU 12 resets the gains G1, G2, and G3 to “0 (zero)” and resets the straight-ahead counter SC to “0 (zero)” (step S50). Thereafter, the ECU 12 ends the reset processing routine.

Therefore, in this embodiment, the following effects can be obtained.
(1) When it is determined that the vehicle is not skidding when turning, the yaw rates YR, Yst, Ygy calculated based on the output signals from the sensors SE5 to SE7 at the timing when the turning of the vehicle ends are used. The abnormality determination process that was performed is executed. On the other hand, if it is determined that the vehicle is skidding when turning, the estimated steering angle converted yaw rate Yst and lateral G converted yaw rate are values that deviate from the actual yaw rate YR, even if the sensors SE5 to SE7 are normal. become. Therefore, the abnormality determination process using each yaw rate YR, Yst, Ygy is not executed. Therefore, it is possible to improve the reliability of the determination result as to whether or not there is a sensor indicating abnormality among the various sensors SE5 to SE7.

  (2) If each yaw difference SY1, SY2, SY3 at the second timing t2, which is the timing at which the vehicle has finished turning, is less than the yaw difference threshold value KSY, the vehicle is not skidding when the vehicle is turning. To be judged. In this state, if each of the sensors SE5 to SE7 is normal, the estimated steering angle converted yaw rate Yst and lateral G converted yaw rate are substantially equal to the actual yaw rate YR. Therefore, when the abnormality determination process is executed in this state and the actual yaw rate YR deviates from the other yaw rates Yst and Ygy, the reliability of the determination result that the yaw rate sensor SE5 is abnormal is increased. On the other hand, if at least one of the yaw differences SY1, SY2, SY3 at the second timing t2 is equal to or greater than the yaw difference threshold KSY, it is determined that a skid has occurred when the vehicle is turning. In this state, the steering angle conversion yaw rate Yst and the lateral G conversion yaw rate, which are estimated values, may be values that deviate from the actual yaw rate YR, so the abnormality determination process using each yaw rate YR, Yst, Ygy is not executed. . Therefore, it is possible to suppress the occurrence of erroneous determination in the abnormality determination process.

  (3) The vehicle of this embodiment is provided with a yaw rate sensor SE5, a steering angle sensor SE6, and a lateral acceleration sensor SE7, and yaw rates YR, Yst, and Ygy are individually calculated using the various sensors SE5 to SE7. Is done. Then, by executing an abnormality determination process using these yaw rates YR, Yst, Ygy, it can be determined whether there is an abnormality in the yaw rate sensor SE5.

  (4) Further, in the present embodiment, when it is detected that the yaw rates YR, Yst, Ygy are deviated from each other when the vehicle turns, that is, the third gain G3 is the lower limit threshold KGmin or the third gain. When G3 exceeds the upper limit threshold value KGmax, it is determined that the vehicle is skidding, and the execution of the abnormality determination process using each yaw rate YR, Yst, Ygy during the turn is restricted. In this way, when it is detected that the vehicle is skidding during the turning of the vehicle, the subsequent execution of the calculation processing of each yaw rate YR, Yst, Ygy is restricted, so the control load of the ECU 12 is reduced. Can be reduced.

  (5) For example, when a vehicle slips at the beginning of a turn, the side slip is canceled during the turn by a driver's operation of the steering wheel, and the turn ends when the side slip is eliminated, the turn From the yaw rates YR, Yst, and Ygy calculated at the end timing, the first side slip may not be detected. In this regard, in the present embodiment, it is possible to determine whether or not the vehicle is skidding using the yaw rates YR, Yst, and Ygy during the turning of the vehicle. Therefore, since it is the structure which determines the presence or absence of the occurrence of skidding of the vehicle in two stages, during the turn and immediately after the end of the turn, erroneous determination due to the abnormality determination process can be more reliably suppressed.

  (6) If the absolute value of each yaw rate YR, Yst, Ygy is less than the first straight travel determination threshold value KYT1 for a predetermined time, it is determined that the vehicle is traveling straight ahead, and thereafter in the sensor abnormality determination processing routine. The process is executed. On the other hand, if there is a yaw rate (for example, the actual yaw rate YR) that does not become less than the first straight travel determination threshold value KYT1 for a predetermined time, there is a possibility that the yaw rate is offset, and an erroneous determination due to the abnormality determination process may occur. It becomes a cause. Therefore, when the above step S31 is a negative determination, the abnormality determination process is not executed. Therefore, it can contribute to suppression of occurrence of erroneous determination by the abnormality determination process.

  (7) Even if the determination in step S31 is affirmative, if each yaw difference SY1, SY2, SY3 is greater than or equal to the second straight travel determination threshold value KYT2, there is a deviation in each yaw rate YR, Yst, Ygy. It is judged. As described above, when deviations occur in the respective yaw rates YR, Yst, and Ygy, there is a possibility that an erroneous determination due to the abnormality determination process caused by the occurrence of the deviation may occur. Therefore, in this embodiment, when each determination result of step S31 and step S33 is affirmative determination, it is determined that the vehicle is traveling straight ahead, and the subsequent processing in the sensor abnormality determination processing routine is executed. Therefore, it can contribute to suppression of occurrence of erroneous determination by the abnormality determination process.

  (8) In the present embodiment, the abnormality determination process is executed using the yaw rate integral values YR_I, Yst_I, and Ygy_I. In other words, the abnormality determination process is executed using all the yaw rates YR, Yst, Ygy calculated during the turning of the vehicle. Therefore, the determination result by the abnormality determination process can be made more reliable than in the case of the abnormality determination process in which the amount of change per unit time of each yaw rate YR, Yst, Ygy at the start of turning of the vehicle is compared. .

  (9) Further, in the present embodiment, when the absolute value of the maximum value Yst_max of the steering angle conversion yaw rate Yst during turning is equal to or less than the maximum turning threshold KYmax, the error component included in each yaw rate YR, Yst, Ygy It is determined that the ratio is large, and the abnormality determination process is not executed. That is, when each yaw rate YR, Yst, Ygy is relatively large, the ratio of error components included in each yaw rate YR, Yst, Ygy is small, so that the abnormality determination process using each yaw rate YR, Yst, Ygy is performed. Is executed. Therefore, the reliability of the determination result by the abnormality determination process can be further improved.

  (10) Furthermore, when the turning time T1 is less than the turning time threshold value KT1, the driver may steer the steering wheel for a moment to stabilize the behavior of the vehicle. In such a case, the amount of data that can be acquired during a turn is too small, and there is a risk that accurate abnormality determination processing will not be performed. That is, it is possible to contribute to further improvement of the reliability of the determination result by the abnormality determination process.

  (11) By improving the reliability of the determination result by the abnormality determination process as described above, the vehicle drive control using each yaw rate YR, Yst, Ygy (for example, ESC (Electric Stability Control)) is further improved. It can be executed with accuracy. If the reliability of the determination result by the abnormality determination process is low, it is necessary to set various threshold values to be large in consideration of the possibility that the yaw rate sensor SE5 is abnormal, and there is a possibility that the ESC start timing may be shifted. is there. In this regard, in the present embodiment, since the reliability of the determination result by the abnormality determination process is high, the various threshold values can be set low, so that ESC can be executed at an appropriate timing. Note that ESC is control for maintaining behavior stability of the vehicle when the vehicle turns.

The embodiment may be changed to another embodiment as described below.
-In embodiment, as long as step S24 is performed between step S21 and step S27, you may perform it at arbitrary timings (for example, timing before step S22). Further, the determination process in step S24 may be omitted. In this case, the process after step S25 is performed irrespective of the length of the turning time T1.

  -In embodiment, if step S23 is performed between step S21 and step S27, you may perform it at arbitrary timings (for example, timing before step S22). Further, the determination process in step S23 may be omitted. In this case, the processing after step S24 is executed regardless of the magnitude of each yaw rate YR, Yst, Ygy.

-In the straight traveling experience determination processing routine of the embodiment, if the determination processing in step S31 is executed, the determination processing in step S33 may be omitted.
In the embodiment, the straight traveling experience determination processing routine may be omitted.

In the embodiment, step S19 may be omitted. Even in this configuration, it is determined in step S33 whether or not skidding has occurred when the vehicle is turning.
In the embodiment, the yaw rate of the vehicle (hereinafter referred to as “wheel converted yaw rate”) is calculated based on the wheel speed of each wheel FR, FL, RR, RL, and abnormality determination processing using the wheel converted yaw rate is executed. You may do it. In this case, the abnormality determination process is executed using four types of yaw rates.

Moreover, you may use a wheel conversion yaw rate instead of the rudder angle conversion yaw rate Yst or lateral G conversion yaw rate Ygy which is an estimated value.
In the embodiment, in step S26, a configuration using at least one of the first yaw difference SY1 and the third yaw difference SY3 may be used. That is, it is not necessary to determine whether or not the second yaw difference SY2 is less than the yaw difference threshold value KSY.

  In the embodiment, in step S26, the first difference between the timing (time) when the sign of the steering angle converted yaw rate Yst changes and the timing when the sign of the actual yaw rate YR changes, and the sign of the steering angle converted yaw rate Yst Whether or not a side slip of the vehicle body has occurred during turning of the vehicle is determined based on a comparison result between the timing at which the sign changes and the second difference between the timing at which the sign of the lateral G-converted yaw rate Ygy changes. Also good. That is, when the difference between the first difference and the second difference is equal to or less than a threshold value set in advance as a determination value as to whether or not the vehicle body has slipped, it is determined that the vehicle body has not slipped. It will be.

  In the embodiment, in the abnormality determination process, the amount of change per unit time of each yaw rate YR, Yst, Ygy immediately after the vehicle starts turning is stored, and the amount of change is compared to indicate an abnormality. A sensor may be specified.

  In the embodiment, lateral acceleration applied to the vehicle may be used as the turning state value of the vehicle. In this case, the lateral acceleration based on the output signal output from the lateral acceleration sensor SE7, and the lateral accelerations (estimated values) calculated based on the output signals output from the yaw rate sensor SE5 and the steering angle sensor SE6, Will be used.

  Further, the steering angle of the steering wheel may be used as the turning state value of the vehicle. In this case, the steering angle based on the output signal output from the steering angle sensor SE6 and the steering angles (estimated values) calculated based on the output signals output from the yaw rate sensor SE5 and the lateral acceleration sensor SE7 are used. It will be.

  In the embodiment, when it is determined that the yaw rate sensor SE5 is abnormal continuously as a result of the abnormality determination processing being executed a plurality of times, it may be output that the yaw rate sensor SE5 is abnormal. Further, when it is determined that the yaw rate sensor SE5 is abnormal in both the abnormality determination process after turning to the right and the abnormality determination process after turning to the left, it is output that the yaw rate sensor SE5 is abnormal. May be.

  In the embodiment, it is embodied in an abnormality determination process for determining whether or not the yaw rate sensor SE5 is abnormal, but an abnormality determination process for determining whether or not the steering angle sensor SE6 is abnormal It may be embodied in. In this case, in the abnormality determination process, the first gain G1 and the third gain G3 are used. Further, it may be embodied in an abnormality determination process for determining whether or not the lateral acceleration sensor SE7 is abnormal. In this case, in the abnormality determination process, the second gain G2 and the third gain G3 are used.

  In the embodiment, the abnormality determination process is performed using two types of yaw rates including the actual yaw rate YR, that is, using the estimated steering angle converted yaw rate Yst or lateral G converted yaw rate Ygy and the actual yaw rate YR. The determination process may be embodied. In this case, when it is established that the first gain G1 is less than the determination lower limit value Kmin or the first gain G1 exceeds the determination upper limit value Kmax, it is determined that one of the sensors is abnormal. be able to.

The block diagram of the vehicle in this embodiment. The flowchart explaining the sensor abnormality determination processing routine (first half part). The flowchart explaining the sensor abnormality determination processing routine (second half part). The flowchart explaining a straight traveling experience determination processing routine. The flowchart explaining an abnormality determination process routine. The flowchart explaining a reset process routine. The timing chart which shows an example of the fluctuation | variation of each yaw rate. The timing chart which shows an example of the fluctuation | variation of each yaw rate at the time of completion | finish of turning.

Explanation of symbols

  12: Abnormality determining device, state value calculating means, side slip determining means at the end of turning, execution restricting means, ECU during turning side slip determining means, straight running judging means, KYT1 ... first straight running judgment threshold as straight running threshold, SE1 to SE4 ... wheel speed sensor as another sensor, SE5 ... yaw rate sensor, SE6 ... steering angle sensor as another sensor, SE7 ... lateral acceleration sensor as another sensor, YR ... actual yaw rate as turning state value, Yst ... Rudder angle conversion yaw rate as a swirling body, Ygy... Horizontal G conversion yaw rate as a turning state value.

Claims (5)

Is there a sensor indicating an abnormality among a plurality of types of sensors (SE1 to SE4, SE5, SE6, SE7) for detecting the turning state of the vehicle as a turning state value (YR, Yst, Ygy) when the vehicle is turning An abnormality determination device (12) that executes an abnormality determination process (S28) for determining whether or not,
The vehicle includes a yaw rate sensor (SE5) for detecting the actual yaw rate (YR) of the vehicle as a turning state value, and other types of sensors (SE1 to SE4, SE6, different from the yaw rate sensor (SE5)). SE7) is installed,
State value calculating means (12) for calculating a plurality of the turning state values (YR, Yst, Ygy) based on output signals output from the yaw rate sensor (SE5) and the other sensors (SE1 to SE4, SE6, SE7). , S10, S11, S12),
When the vehicle turns, the vehicle body skids when the vehicle turns based on the comparison result of the turning state values (YR, Yst, Ygy) calculated by the state value calculating means (12, S10, S11, S12). A side slip determination means (12, S26) at the end of turning to determine whether or not the
An execution restricting means (12, S28) for restricting the execution of the abnormality determining process (S27) when it is determined by the skid determining means (12, S26) at the end of the turn that a side slip has occurred when the vehicle is turning; An abnormality determination device comprising: The vehicle is provided with three or more types of sensors (SE1 to SE4, SE5, SE6, SE7) for detecting the turning state of the turning vehicle, including the yaw rate sensor (SE5),
The state value calculation means (12, S10, S11, S12) is based on the output signals output from the sensors (SE1 to SE4, SE5, SE6, SE7), and has three or more turning state values (YR, Yst). , Ygy). Whether or not a side slip of the vehicle body has occurred based on the comparison result of the respective turning state values (YR, Yst, Ygy) calculated by the state value calculating means (12, S10, S11, S12) when the vehicle turns. The vehicle further includes a side slip judging means (12, S19) for judging,
The execution restricting means (12, S28) executes the abnormality determination process (S27) when it is determined by the side-slip determining means (12, S19) during turning that the vehicle body is skidding. The abnormality determination device according to claim 2 to be regulated. Each of the turning state values (YR, Yst, Ygy) calculated by the state value calculating means (12, S10, S11, S12) is set in advance as a reference value for determining whether the vehicle has traveled straight ahead. When it is less than the threshold value (KYT1), the vehicle further includes a straight traveling determination means (12, S13) for determining that the vehicle has traveled straight.
The execution restricting means (12, S28) may be the timing when the turning of the vehicle is completed when the straight traveling determining means (12, S13) determines that the vehicle has not experienced straight traveling. The abnormality determination apparatus according to any one of claims 1 to 3, wherein execution of the abnormality determination process (S27) is restricted. Is there a sensor indicating an abnormality among a plurality of types of sensors (SE1 to SE4, SE5, SE6, SE7) for detecting the turning state of the vehicle as a turning state value (YR, Yst, Ygy) when the vehicle is turning An abnormality determination method for executing an abnormality determination process (S27) for determining whether or not,
The vehicle includes a yaw rate sensor (SE5) for detecting the actual yaw rate (YR) of the vehicle as a turning state value, and other types of sensors (SE1 to SE4, SE6, different from the yaw rate sensor (SE5)). SE7) is installed,
A state value calculating step in which a plurality of the turning state values (YR, Yst, Ygy) are calculated based on output signals output from the yaw rate sensor (SE5) and the other sensors (SE1 to SE4, SE6, SE7). S10, S11, S12),
When the vehicle turns, based on the comparison result of each turning state value (YR, Yst, Ygy) calculated in the state value calculating step (S10, S11, S12) executed at the timing when the turning of the vehicle is finished, When it is determined whether or not a side slip has occurred, a side slip determination step at the end of turning (S26),
An execution restriction step (S28) for restricting the execution of the abnormality determination process (S27) when it is determined in the side slip determination step (S26) at the end of the turn that a side slip of the vehicle body has occurred when the vehicle turns. An abnormality determination method having:

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