JP5286916B2 - Vehicle behavior sensor temperature correction device - Google Patents

Description

  The present invention relates to a vehicle behavior sensor temperature correction device that can set a vehicle control intervention threshold value in consideration of a temperature drift that a zero point of an output of a vehicle behavior sensor drifts according to temperature.

Conventionally, Patent Document 1 discloses a method for adjusting an output signal of an angular velocity sensor. In this output signal adjustment method, in order to perform temperature correction of the angular velocity sensor, correction information is written in an EEPROM built in the sensor, and then, in the vehicle assembly process, electronic control for performing sensor and vehicle behavior control, etc. When the apparatus (hereinafter referred to as ECU) is connected, the correction information written in the EEPROM built in the sensor is transferred to the ECU away from the sensor and stored in the memory of the ECU. Then, the angular velocity detection signal of the angular velocity sensor and the temperature detection signal of the temperature sensor provided in the angular velocity sensor are input to the ECU, and the ECU corrects the angular velocity detection signal based on the correction information and the temperature detection signal stored in the memory. Car behavior control is performed.
Japanese Patent Laid-Open No. 2003-242637

  However, there is a problem that a complicated and non-generic process is required, such as a process of writing correction information stored in the EEPROM built in the sensor to the ECU after the sensor is assembled to the vehicle.

  Further, the temperature correction is performed by providing one temperature sensor in the angular velocity sensor, but since only one temperature sensor is provided, fail-safe cannot be performed when the temperature sensor fails. That is, since a failure of the temperature sensor cannot be detected, temperature correction based on an erroneous temperature detection signal is performed, and vehicle behavior control based on the temperature correction is performed. Therefore, accurate vehicle behavior control cannot be performed.

  In view of the above points, the present invention has as its first object to provide a versatile vehicle behavior sensor temperature correction device that does not require a correction information writing step after a vehicle behavior sensor is assembled to a vehicle. To do.

  It is a second object of the present invention to provide a vehicle behavior sensor temperature correction device capable of fail-safe when a temperature sensor fails.

  In order to achieve the above object, according to the first aspect of the present invention, the temperature calculated from the temperature detection signals of the first and second temperature sensors (4a, 5a) is compared with the vehicle behavior sensor temperature correction device. An abnormality determining means (105) for determining whether or not the first and second temperature sensors (4a, 5a) are normal, a stop determining means (115) for determining whether or not the vehicle is stopped, When the first and second temperature sensors (4a, 5a) are normal and the vehicle is stopped, 0 point learning at the time of stop is learned, which is 0 point of the physical quantity at the time of stop. Means (120), temperature storage means (125) for storing the temperature (Ty0) of the vehicle behavior sensor (4) when learning the zero point at the time of stop, and the temperature (Ty0) when learning the zero point at the time of stop Temperature difference calculation to calculate the amount of temperature change (ΔTy) from Means (135) and threshold correction means (100, 140 to 160, 230 to 240) for correcting the control intervention threshold (Th) according to the magnitude of the temperature change amount (ΔTy). .

  In this way, when the two temperature sensors (4a, 5a) are utilized and the temperature sensors (4a, 5a) are normal, the zero point learning is performed when the vehicle stops, and thereafter the zero point learning is performed. The control intervention threshold (Th) is set in accordance with the temperature change amount (ΔTy) with respect to the temperature when the zero point learning is performed during the period until it is performed. This makes it possible to provide a versatile vehicle behavior sensor temperature correction device that does not require a correction information writing step after the vehicle behavior sensor is assembled to the vehicle.

  Specifically, as described in claim 2, the threshold correction means (100, 140 to 160, 230 to 240) increases the change in the control intervention threshold (Ty) as the temperature change amount (ΔTy) increases. Can be corrected as follows.

According to the third aspect of the present invention, when the first and second temperature sensors (4a, 5a) are normal and the learning of the zero point at the time of stop is performed for the first time after turning on the ignition switch, Temperature of vehicle behavior sensor (4) when learning 0 point and temperature (Ty0) when learning 0 point at the time of previous stop that was already stored in the temperature storage means (125) before turning on the ignition switch And the change of the 0 point to be learned this time from the previously learned 0 point is smaller than the threshold value set corresponding to these temperature differences, and no 0 point deterioration has occurred. Deterioration determination means (110) for determining whether or not the zero point learning means (120) at the time of stop determines that the zero point to be learned this time is stopped when it is determined that no zero point deterioration has occurred. Learning as 0 points It is characterized in Rukoto.

  If 0 points learned last time and 0 points that are going to be learned this time are not changing much, 0 points have not deteriorated, so learning may be carried out. It is not preferable to carry out learning. For this reason, the current learning is attempted only when the change of the 0 point to be learned this time from the previously learned 0 point is smaller than the threshold value set corresponding to the temperature difference before and after turning on the ignition switch. By learning 0 point as 0 point at the time of stop, it becomes possible to learn 0 point which has not deteriorated.

In the invention according to claim 4 , the stop 0 point learning means (120) is also provided with the stop 0 point each time when the vehicle stops after learning the stop 0 point for the first time after turning on the ignition switch. The temperature storage means (125) also stores the temperature (Ty0) when learning the 0 point at the stop every time the 0 point at the stop is learned.

  As described above, since the first 0-point deterioration determination is already performed after the ignition switch is turned on, the 0-point deterioration determination is normally normal after the second time, and the 0-point learning is performed as it is. Temperature (Ty0) is stored.

In the fifth aspect of the invention, the abnormality determining means (105) repeatedly determines whether or not the first and second temperature sensors (4a, 5a) are normal, and the zero-point learning means during stop ( 120), even if it is determined that the first and second temperature sensors (4a, 5a) are once normal by the abnormality determining means (105), the first and second temperature sensors (4a, 5a) are When it is determined that it is not normal, 0 point learning at the time of stop is not performed.

  Thus, even if it is determined that the first and second temperature sensors (4a, 5a) are once normal, the first and second temperature sensors (4a, 5a) are subsequently determined to be not normal. By not learning the zero point at the time of stop, it is possible to perform fail-safe when the temperature sensor fails, and to accurately learn the zero point at the time of stop.

In the invention according to claim 6 , the straight travel determination means (205) for determining whether or not the vehicle is traveling straight, and when the vehicle is traveling straight, the physical quantity is 0 point during the straight travel. Traveling 0 point learning means (210) for learning 0 points during traveling, vehicle speed storage means (215) for storing the vehicle speed (V0) when learning 0 points during traveling, and learning of 0 points during traveling Speed change amount calculating means (225) for calculating a speed change amount (ΔV) from the vehicle speed (V0) when the vehicle speed is changed, and the threshold value correcting means (100, 140 to 160, 230 to 240) are speed changes. The control intervention threshold (Th) is corrected according to the magnitude of the amount (ΔV).

  Thus, the control intervention threshold (Th) can be corrected based on the speed change amount (ΔV).

In the seventh aspect of the invention, the threshold correction means (100, 140 to 160, 230 to 240) does not start the vehicle behavior control before the zero point learning is performed after the ignition switch is turned on. The control intervention threshold (Th) is set to a maximum value.

  In this way, when the temperature sensor (4a, 5a) is still unclear whether the temperature sensor (4a, 5a) is still normal, or when the ignition switch is turned on, the temperature suddenly changes due to the heat generated by the heat-generating component for a while. It is possible to prevent the vehicle behavior control from being started in a transient state.

In the invention described in claim 8 , the threshold value correction means (100, 140 to 160, 230 to 240) is a value used for correcting the control intervention threshold value (Th), and the control intervention increases as a larger value is set. It is characterized in that the control intervention threshold (Th) is corrected by setting a zero-point drift margin (Yd2) that is a value that allows the threshold (Th) to be corrected to a large value.

  Thus, the threshold value correction means (100, 140 to 160, 230 to 240) sets the control intervention threshold value (Yd2) to be used for correcting the control intervention threshold value (Th). Th) can be corrected.

According to the ninth aspect of the present invention, the vehicle behavior sensor is the yaw rate sensor (4), and the temperature drift correction value from 0 point from the actual yaw rate that is the actual yaw rate obtained based on the detection signal of the yaw rate sensor (4). When the absolute value of the difference between the value obtained by subtracting (Yerror) and the target yaw rate, which is the target yaw rate, is greater than the control intervention threshold (Th), vehicle skid prevention control is executed as vehicle behavior control. Yes.

  Thus, the skid prevention control can be given as the vehicle behavior control. In this case, the control intervention threshold (Th) to be compared with the absolute value of the difference between the actual yaw rate and the target yaw rate can be corrected as described in the above claims.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

(First embodiment)
In the present embodiment, a case will be described in which the vehicle behavior sensor temperature correction device is provided in a side slip prevention control (ESC (Electronic Stability Control) ECU (hereinafter referred to as ESC-ECU)).

  The ESC-ECU is mounted, for example, in an engine room. The engine room is an environment exposed to the outside air and is also an environment affected by the heat generated by the engine. It must be compatible with a wide range. In the present embodiment, the vehicle behavior sensor temperature correction device is adapted to cope with such a wide range. FIG. 1 shows a block diagram of an ESC-ECU 1 provided with a vehicle behavior sensor temperature correction apparatus according to the present embodiment, and the details of the ESC-ECU 1 and the vehicle behavior sensor temperature correction apparatus will be described with reference to this figure. .

  As shown in FIG. 1, the ESC-ECU 1 includes an ESC microcomputer 2 and an EEPROM 3, and a yaw rate sensor 4 and a G sensor 5 that serve as vehicle behavior sensors.

The ESC microcomputer 2 is a control unit for executing ESC control, and is configured by a well-known microcomputer including a CPU, a ROM, a RAM, an I / O, and the like, and performs various processes according to a program stored in the ROM or the like. . For example, the ESC microcomputer 2 receives the output signals of the vehicle speed sensor 6 and the steering angle sensor 7 provided outside the yaw rate sensor 4, the G sensor 5 and the ESC-ECU 1, and the yaw rate actually generated (hereinafter, the actual yaw rate). Yr, acceleration, vehicle speed, and rudder angle are calculated, and a yaw rate target value (hereinafter referred to as target yaw rate) Yi is calculated based on the vehicle speed, rudder angle, and the like. Then, based on the calculation result, correction is performed by subtracting the temperature drift correction value Y _error corresponding to the temperature drift from the actual yaw rate Yr, or the control intervention threshold Th for ESC control is set in consideration of the temperature drift. Perform temperature drift correction. Based on this, the ESC control is started based on the value obtained by subtracting the temperature drift correction value Y _error from the actual yaw rate Yr, the target yaw rate Yi, and the set control intervention threshold Th, and the ESC control is started. In order to execute the ESC control according to the calculation result, a control signal for applying a braking force to the target wheel for ESC control is output to a brake control actuator (not shown).

For example, the ESC control controls that the absolute value | (Yr−Y _error ) −Yi | of the difference between the value obtained by subtracting the temperature drift correction value Y _error from the actual yaw rate Yr and the target yaw rate Yi exceeds the control intervention threshold Th. This is done as a start condition.

The temperature drift correction value Y _error is set to the amount of deviation of the actual yaw rate Yr from the zero point, which is the point at which the yaw rate becomes 0 after removing the temperature drift, so the temperature drift correction value Y _error is subtracted from the actual yaw rate Yr. For example, the true yaw rate can be calculated. However, since the zero point fluctuates due to temperature drift, the temperature drift correction value Y _error must be updated according to the temperature drift. For this reason, by performing the zero point learning of calculating the temperature drift correction value Y _error to be subtracted from the actual yaw rate Yr by calculating the temperature drift when the actual yaw rate Yr should be 0 or when going straight ahead, the time drift is calculated every moment. The temperature drift correction value Y _error corresponding to the changing temperature drift can be updated.

In addition, even after learning 0 point, the temperature drift correction value Y _error changes according to the temperature change with respect to the temperature at the time of 0 point learning and the vehicle speed. _{The error} cannot be updated. Therefore, instead of calculating the temperature drift correction value Y _error , the control intervention threshold Th is corrected so as to follow the temperature drift. That is, the control intervention threshold value Th is set in consideration of the temperature drift, considering that the absolute value | (Yr−Y _error ) −Yi | Thus, accurate ESC control taking temperature drift into consideration is executed. The temperature drift correction process including the setting of the control intervention threshold Th described here will be described in detail later. However, since a specific control method in the ESC control is conventionally known, a description thereof is omitted here.

  The EEPROM 3 functions as a data storage unit in which data is written and erased through the ESC microcomputer 2 and data can be transmitted to the ESC microcomputer 2 by reading from the ESC microcomputer 2. The EEPROM 3 is used for ESC control such as temperature detection signals (temperature information) of temperature sensors 4a and 5a provided in the yaw rate sensor 4 and G sensor 5 and vehicle speed information obtained based on detection signals of the vehicle speed sensor 6. Various data are stored.

  The yaw rate sensor 4 detects a yaw rate corresponding to the speed in the rotational direction of the vehicle. The yaw rate detected by the yaw rate sensor 4 is the actual yaw rate Yr as described above. The yaw rate sensor 4 of the present embodiment is formed based on a semiconductor process using a semiconductor substrate, and a temperature sensor 4a configured using, for example, a temperature characteristic of a diode is built in the same semiconductor substrate. For this reason, the temperature of the yaw rate sensor 4 can be detected by the temperature sensor 4a. From the yaw rate sensor 4, an output signal indicating the yaw rate and a temperature detection signal of the temperature sensor 4a are transmitted to the ESC microcomputer 2.

  The G sensor 5 detects the longitudinal acceleration of the vehicle. The G sensor 5 of the present embodiment is also formed based on a semiconductor process using a semiconductor substrate, and a temperature sensor 5a configured using, for example, a temperature characteristic of a diode is built in the same semiconductor substrate. For this reason, although the temperature of the G sensor 5 can be detected by the temperature sensor 5a, since the G sensor 5 is arranged in the vicinity of the yaw rate sensor 4, it is used for redundancy for detecting the temperature of the yaw rate sensor 4. Used as a sensor. From the G sensor 5, an output signal indicating acceleration and a temperature detection signal of the temperature sensor 5a are transmitted to the ESC microcomputer 2.

  Thus, the ESC-ECU 1 of the present embodiment is configured. The part used for executing the temperature drift correction process in the ESC-ECU 1, that is, the part for performing the temperature drift correction in the ESC microcomputer 2, the temperature sensors 4a and 5a of the yaw rate sensor 4 and the G sensor 5, etc. It corresponds to a sensor temperature correction device.

  The ESC-ECU 1 configured as described above has the ESC microcomputer 2, the EEPROM 3, the yaw rate sensor 4, and the G sensor 5 mounted on the wiring board accommodated in the case of the ESC-ECU 1, and then the temperature drift correction processing is performed on the EEPROM 3. Or by writing a program for executing ESC control.

Next, temperature drift correction processing including setting of the control intervention threshold Th by the ESC-ECU 1 completed as described above will be described. The temperature drift correction process is a process for calculating a temperature drift correction value Y _error to be subtracted from the actual yaw rate Yr and a process for setting the control intervention threshold Th. Specifically, the timing at which the temperature drift correction value Y _error can be calculated is obtained, and the temperature drift correction value Y _error is calculated every time the calculation timing comes, and occurs until the next calculation timing comes after the calculation. The control intervention threshold Th is set in anticipation of temperature drift. Since the calculation timing of the temperature drift correction value Y _error is when the vehicle is stopped and when the vehicle is traveling straight, 0 point learning processing corresponding to each of them is performed.

  2 and 3 are flowcharts of the stop yaw rate 0-point learning process and the running yaw rate 0-point learning process, respectively. The stop yaw rate 0-point learning process and the running yaw rate 0-point learning process are executed in parallel, and are always executed at predetermined control cycles during a period in which an ignition switch (not shown) is turned on.

First, the stop yaw rate zero point learning process will be described with reference to FIG. This process is based on the assumption that no yaw rate is generated when the vehicle is stopped, and calculates the temperature drift correction value Y _error using the time when the vehicle is stopped as the calculation timing. Correspondingly, the control intervention threshold Th is set.

Specifically, in step 100, a yaw rate zero point margin Yd1 is set. The yaw rate zero-point margin Yd1 here means the maximum temperature drift amount with respect to the zero point during the previous zero-point learning (see step 120 described later). The zero point is the point at which the yaw rate becomes zero after removing the temperature drift as described above, so the actual yaw rate Yr obtained from the yaw rate sensor 4 should be zero when the yaw rate should not have occurred. It is a point. Since the actual yaw rate Yr includes a temperature drift, the temperature drift correction value Y _error is subtracted from the actual yaw rate Yr in order to remove an error corresponding to the temperature drift. The point corresponding to this temperature drift correction value Y _error is 0 point. Therefore, the maximum temperature drift amount that may deviate from this zero point is obtained as the yaw rate zero point margin Yd1, and the control intervention threshold Th is shifted from the baseline (reference value) by a value corresponding to the maximum temperature drift amount. Set.

  At this point in time, it is completely unknown whether or not the ESC control is started, such as whether or not the temperature sensors 4a and 5a are still normal, and the ESC-ECU 1 for a while after the ignition switch is turned on. This is a transitional state in which the temperature inside changes suddenly due to heat generated by the heat-generating component. Therefore, in setting the yaw rate zero point margin Yd1 at step 100, the control intervention threshold Th is set high so that the ESC control does not malfunction by forcibly setting the maximum value Yd_max of the yaw rate zero point margin Yd1. To do.

  Next, in step 105, it is determined whether or not the temperature sensors 4a and 5a are normal. This determination is performed by determining whether or not the temperatures obtained from the temperature detection signals of the temperature sensors 4a and 5a indicate substantially equal temperatures. For example, if the absolute value of the temperature difference obtained from the temperature detection signals of the temperature sensors 4a and 5a is equal to or less than a predetermined threshold value, it is determined that it is normal. If an affirmative determination is made here, the process proceeds to step 110, and if a negative determination is made, the control intervention threshold Th should not be corrected, so the process returns to step 100.

  In step 110, it is determined whether or not the yaw rate zero point deterioration is normal. The yaw rate 0-point deterioration is the timing when the ignition switch is turned on this time and the 0-point learning at the time of stop described later is performed for the first time, and the previously learned 0 point is compared with the 0 point that is being learned this time, This means that the 0 point to be learned this time exceeds the range that can be changed with respect to the previously learned 0 point. In other words, if the 0 point learned last time and the 0 point to be learned this time have not changed so much, the yaw rate has not deteriorated by 0 point. Therefore, learning may be performed, but if the change has greatly changed, 0 point deterioration will occur. Therefore, it is not preferable to carry out learning. Therefore, it is determined whether or not the yaw rate 0-point deterioration is normal. If normal, the process proceeds to the subsequent processes.

  In this determination of the 0-point deterioration of the yaw rate, if the temperature at the time of the previous 0-point learning and the temperature at the time of the current learning are the same, the difference between the previously learned 0 point and the current 0-point learning Can be compared with a predetermined threshold value, but if there is a temperature difference, a temperature drift corresponding to the temperature difference occurs, so the previously learned 0 point is compared with the 0 point that is being learned this time with one threshold value. I can't. For this reason, the threshold value is changed according to the temperature difference, and the threshold value that is determined to be deteriorated as the temperature difference is increased is set to a threshold value that takes into account the temperature drift.

  In the next step 115, it is determined whether or not the stop 0 point condition is satisfied. The stop 0 point condition means a condition in which the vehicle stops and 0 point learning can be performed. Here, the vehicle speed calculated based on the detection signal of the vehicle speed sensor 6 is 0. As a condition. If a positive determination is made here, the process proceeds to step 120, and if a negative determination is made, the process returns to step 100.

In step 120, zero point learning at the time of stop is performed. Specifically, in the stop zero learning, the actual yaw rate Yr that is occurring is calculated and the difference between the calculated actual yaw rate Yr from 0 is used as a temperature drift and the ± sign of the actual yaw rate Yr is replaced. To calculate the temperature drift correction value Y _error . Since the point corresponding to the temperature drift correction value Y _error is zero, the temperature drift correction value Y _error is stored in the EEPROM 3 or the like as a value corresponding to the zero point. In step 125, the temperature Ty0 at that time is calculated from the temperature detection signal of the temperature sensor 4a provided in the yaw rate sensor 4 and stored in a built-in RAM or the like.

  Then, the process proceeds to step 130 to determine whether or not the temperature sensors 4a and 5a are normal and the yaw rate sensor 4 is normal. Whether or not the temperature sensors 4a and 5a are normal is determined by the same processing as in step 105 described above. Whether or not the yaw rate sensor 4 is normal must be determined by checking whether the actual yaw rate Yr remains at a fixed value and does not change, or is a value that cannot be considered normally. If it is applicable, it is determined that it is not normal. If an affirmative determination is made here, the process proceeds to step 135, and if a negative determination is made, there is a possibility that accurate ESC control cannot be performed due to a sensor abnormality, and thus the process ends.

  In step 135, the temperature change amount ΔTy from the temperature Ty0 stored in step 125 is calculated. Specifically, the temperature change amount ΔTy is calculated by subtracting the temperature Ty0 from the temperature at the current control cycle. Subsequently, the routine proceeds to step 140, where it is determined whether or not the temperature change amount ΔTy exceeds 30 ° C. which is the first threshold value. If not, the routine proceeds to step 145, where the yaw rate zero point drift margin Yd1 is set to 0 deg / s. Setting, that is, no change. If the temperature change amount ΔTy exceeds 30 ° C., the process proceeds to step 150 to determine whether the temperature change amount ΔTy exceeds 60 ° C., which is a second threshold value that is larger than the first threshold value. If the temperature change amount ΔTy does not exceed 60 ° C., the process proceeds to step 155 and the yaw rate zero point drift margin Yd1 is set to 0.5 deg / s. If it exceeds, the process proceeds to step 160 and the yaw rate zero point drift margin is set. Set to 1.5 deg / s.

  Note that deg / s corresponds to the unit of the actual yaw rate Yr detected by the yaw rate sensor 4. Therefore, by setting the yaw rate zero point drift margin Yd1 to 0.5 deg / s, for example, the maximum temperature drift amount expected for the actual yaw rate Yr is increased by the temperature drift corresponding to the temperature difference of 30 ° C.

  Thereafter, the process proceeds to step 165, and it is determined again whether or not the stop 0 point condition is satisfied as in step 115. Here, if the stop 0 point condition is satisfied, the process proceeds to steps 120 and 125 again to perform the stop 0 point learning, and stores the temperature change amount ΔTy, and if not satisfied, the processing from step 130 is repeated.

  In this way, zero point learning at the time of stop can be performed. Thereby, it becomes possible to correct the temperature drift according to the temperature change from the learned 0 point.

Next, the running yaw rate zero point learning process will be described with reference to FIG. This process is based on the premise that no yaw rate is generated when the vehicle is traveling straight, and the temperature drift correction value Y _error is calculated using the time when the vehicle is traveling straight as the calculation timing, and the subsequent temperature change The control intervention threshold Th is set corresponding to

  Specifically, in step 200, a yaw rate zero point margin Yd2 is set. The yaw rate zero point margin Yd2 here means a difference from the zero point that is finally set by correcting the yaw rate zero point margin Yd1 according to the vehicle speed as will be described later. Eventually, the ESC microcomputer 2 sets the control intervention threshold Th so that the value corresponding to the yaw rate 0-point margin Yd2 is shifted from the baseline. Here, the yaw rate zero point margin Yd1 corresponding to the maximum temperature drift amount set in the stop yaw rate zero point learning process is set as the yaw rate zero point margin Yd2.

  Next, in step 205, it is determined whether or not the zero point condition during travel is satisfied. The traveling zero point condition means that the vehicle can perform zero point learning while the vehicle is traveling. Here, the steering angle calculated based on the detection signal of the steering angle sensor 7 is zero. That is, the condition is that the vehicle is traveling straight. If a positive determination is made here, the process proceeds to step 210, and if a negative determination is made, the process returns to step 200.

In step 210, zero point learning is performed during traveling. Specifically, the actual yaw rate Yr that is currently generated is calculated even when learning 0 points during traveling, and the ± sign of the actual yaw rate Yr is replaced with the difference from the calculated actual yaw rate Yr from 0 as a temperature drift. To calculate the temperature drift correction value Y _error . Since the point corresponding to the temperature drift correction value Y _error is zero, the temperature drift correction value Y _error is stored in the EEPROM 3 or the like as a value corresponding to the zero point. Further, the process proceeds to step 215, where the vehicle speed V0 at that time is calculated from the vehicle speed detection signal of the vehicle speed sensor 6 and stored in a built-in RAM or the like.

  Then, the process proceeds to step 220, and it is determined whether or not the yaw rate sensor 4 is normal. Whether the yaw rate sensor 4 is normal is determined in the same manner as in step 130 described above. If an affirmative determination is made here, the process proceeds to step 225. If a negative determination is made, there is a possibility that accurate ESC control cannot be performed due to a sensor abnormality.

  In step 225, the vehicle speed change amount ΔV from the vehicle speed V0 stored in step 215 is calculated. Specifically, the vehicle speed change amount ΔV is calculated by subtracting the vehicle speed V0 from the vehicle speed at the current control cycle. Then, it progresses to step 230 and it is determined whether vehicle speed variation | change_quantity (DELTA) V is not 0 km / h. Here, if the vehicle speed change amount ΔV is 0 km / h, there is no need for temperature drift correction according to the vehicle speed, so the routine proceeds to step 235 and the yaw rate zero point margin Yd2 is set to 0 deg / s. If the vehicle speed change amount ΔV is not 0 km / h, the yaw rate zero-point margin Yd2 is set as follows according to the vehicle speed change amount ΔV.

(Equation 1) Yd2 = Yd1 × (ΔV / V0)
In this way, the maximum temperature drift amount expected for the actual yaw rate Yr can be set in consideration of the temperature drift according to the vehicle speed change amount ΔV0.

  Thereafter, the process proceeds to step 245, and it is determined again whether or not the traveling zero point condition is satisfied as in step 215. If the traveling zero point condition is satisfied, the process proceeds to steps 210 and 215 again to perform the traveling zero point learning and stores the vehicle speed change amount ΔV. If not satisfied, the processing from step 220 is repeated.

  In this way, zero point learning during running can be performed. As a result, it is possible to perform 0 point learning during traveling and to correct a temperature drift according to the vehicle speed from the learned 0 point.

  FIG. 4 is a timing chart when the stop yaw rate 0 point learning and the running yaw rate 0 point learning are performed as described above.

  As shown in this figure, when the vehicle has traveled after the ignition switch is turned on and before the validity determination that the temperature sensors 4a and 5a are normal is issued, the result of the learning of the yaw rate 0 during traveling is obtained. Based on this, a control intervention threshold Th is set.

First, at the same time when the ignition switch is turned on, the temperature drift correction value Y _error corresponding to the zero point, specifically, the zero point stored in the EEPROM 3 is read, and the temperature drift correction of the actual yaw rate Yr is performed using the read value. , Whether or not the absolute value | (Yr−Y _error ) −Yi | exceeds the control intervention threshold Th is determined. The period from time t1 when the vehicle travels straight and the travel zero point condition is satisfied is a transitional state in which the temperature in the ESC-ECU 1 changes suddenly due to heat generated by the heat-generating component after the ignition switch is turned on. Therefore, the yaw rate zero point drift margin is set to Yd2 = Yd1 = Yd_max. For this reason, the control intervention threshold Th is set to the maximum value so that the ESC control is not started.

Next, when the travel 0 point condition is satisfied at time t1, travel 0 point learning is performed. As a result, the value obtained by subtracting the temperature drift correction value Y _error from the actual yaw rate Yr becomes a value that does not include any temperature drift (= 0), so the control intervention threshold Th is returned to the baseline. After this, the yaw rate zero point drift margin Yd2 is set according to the vehicle speed change amount ΔV during the period until the traveling zero point condition is satisfied again. However, at this time, the yaw rate zero-point drift margins Yd1 and Yd2 corresponding to the temperature change amount ΔTy from when the previous 0-point learning was performed are not set, and the maximum values thereof are set, so the control intervention threshold Th Varies greatly depending on the vehicle speed.

  Although the yaw rate zero-point drift margin Yd2 and the control intervention threshold Th are set according to the vehicle speed here, these can be set in consideration of the temperature drift according to the temperature rise. For example, if the ESC-ECU 1 is set in the engine room, the maximum rising temperature (maximum temperature change gradient) in the engine room can be assumed after turning on the ignition switch. If the control intervention threshold Th is set based on the temperature drift corresponding to the assumed maximum temperature rise, a more accurate control intervention threshold Th can be set.

After such traveling 0 point learning is repeated, an effective determination is made that the temperature sensors 4a, 5a are normal at time t2, and when the vehicle stops at time t3 and the stop 0 point condition is satisfied, 0 is satisfied. Point deterioration determination is performed. If the zero point deterioration determination is normal, zero point learning at the time of stop is performed. As a result, the value obtained by subtracting the temperature drift correction value Y _error from the actual yaw rate Yr becomes a value that does not include any temperature drift (= 0), so the control intervention threshold Th is returned to the baseline. Then, the yaw rate zero-point drift margin Yd2 is set according to the temperature change amount ΔTy until the traveling zero point condition is satisfied again or the stop zero point condition is satisfied. For example, if the temperature change amount ΔTy exceeds 30 ° C. at the time point t4, the yaw rate zero point drift margin Yd1 = 0.5 deg / s, and this amount is added to the maximum temperature drift amount of the actual yaw rate Yr. Therefore, the control intervention threshold Th also becomes a large value.

  When the traveling zero point condition is satisfied again at time t5, the traveling zero point learning is performed, the yaw rate zero point drift margin Yd2 is calculated according to the vehicle speed change amount ΔV, and the yaw rate is changed with the change in the vehicle speed change amount ΔV. Since the zero point drift margin Yd2 changes, the control intervention threshold Th also changes. However, when the temperature change amount ΔTy becomes 30 ° C. or less as at time t6, the yaw rate zero point drift margin Yd2 becomes 0 again, so that the control intervention threshold Th is returned to the baseline.

  Thereafter, when the change amount ΔTy exceeds 30 ° C. or 60 ° C. at the time t7 or the time t8, the yaw rate zero-point drift margins Yd1 and Yd2 change accordingly, so that the control intervention threshold Th also changes. This continues for a period in which the validity determination that the temperature sensors 4a and 5a are normal continues. Then, when the vehicle stops again at time t9, 0-point learning at the time of stop is performed, but since the first yaw rate 0-point deterioration determination has already been performed after the ignition switch is turned on, the second and subsequent times are normal. The zero point deterioration determination becomes normal, and the zero point learning is performed as it is, and the temperature Ty0 at that time is stored.

  Subsequently, when the validity determination is interrupted at time t10, the control intervention threshold Th is set again only by the traveling yaw rate 0-point learning process, and the same operation from time t1 to time t3 is performed. Become.

  As described above, in the present embodiment, the two temperature sensors 4a and 5a are utilized, and when the temperature sensors 4a and 5a are normal, 0-point learning is performed when the vehicle stops, and thereafter 0 During the period until point learning is performed, the control intervention threshold Th is set according to the temperature change amount ΔTy with respect to the temperature when the zero point learning is performed. This makes it possible to provide a versatile vehicle behavior sensor temperature correction device that does not require a correction information writing step after a vehicle behavior sensor such as the yaw rate sensor 4 or the G sensor 5 is assembled to the vehicle. Become.

  Further, when the temperature sensors 4a and 5a are not normal, temperature drift correction based on the temperature change amount ΔTy is not performed. For this reason, it becomes possible to perform the fail safe at the time of failure of the temperature sensors 4a and 5a.

(Other embodiments)
In the embodiment described above, the ESC-ECU 1 includes the yaw rate sensor 4 including the temperature sensor 4a and the G sensor 5 including the redundant temperature sensor 5a, but these are separated from the ESC-ECU 1. You may install in the place. That is, it is sufficient that the yaw rate sensor 4 to be subjected to temperature drift correction, the temperature sensor 4a for detecting the temperature thereof, and the redundant temperature sensor 5a for measuring the same temperature as the temperature sensor 4a are installed at the same position. It is not necessary to be arranged at the same position as the ECU for executing vehicle behavior control such as the ESC-ECU 1. In the above embodiment, the built-in type in which the temperature sensors 4a and 5a are built in the yaw rate sensor 4 and the G sensor 5 has been described as an example. However, the temperature of the yaw rate sensor 4 to be corrected for the temperature drift is described. It does not have to be a built-in type as long as it can be detected.

  In the above embodiment, the temperature change amount ΔTy is compared with the first threshold value and the second threshold value to set the yaw rate zero point drift margin Yd1, but the yaw rate zero point drift margin Yd1 increases as the temperature change amount ΔTy increases. May be set to a linearly large value.

  In the above embodiment, the yaw rate sensor 4 and the G sensor 5 are described as examples of the vehicle behavior sensor. However, other vehicle behavior sensors that require temperature drift correction, for example, the temperature drift correction value of the G sensor 5 are corrected. The present invention can also be applied to semiconductor sensors such as pressure sensors.

  The steps shown in each figure correspond to means for executing various processes. Specifically, the part that executes the process of step 105 performs abnormality determination, the part that executes the process of step 110 performs deterioration determination, the part that executes the process of step 115 executes stop determination, and the process of step 120 The part that performs the process of step 125 is the temperature storage means, the part that executes the process of step 135 is the temperature difference calculating means, and the processes of steps 100, 140 to 160, and 230 to 240 are performed. The part to be executed is a threshold correction means, the part to execute the process of step 205 is a straight-ahead determination means, the part to execute the process of step 210 is a zero point learning means during travel, the part to execute the process of step 215 is a vehicle speed storage means The part that executes the processing of step 225 corresponds to vehicle speed change amount calculation means.

It is a figure which shows the block block diagram of ESC-ECU1 provided with the vehicle behavior sensor temperature correction apparatus concerning 1st Embodiment of this invention. It is a flowchart of the 0 point learning process at the time of a stop yaw rate. It is a flowchart of a running yaw rate 0 point learning process. It is a timing chart at the time of performing the yaw rate 0 point learning at the time of stop and the yaw rate 0 point learning at the time of traveling.

Explanation of symbols

1 ... ESC-ECU, 2 ... ESC microcomputer, 3 ... EEPROM,
4 ... Yaw rate sensor, 4a ... Temperature sensor, 5 ... G sensor, 5a ... Temperature sensor,
6 ... Vehicle speed sensor, 7 ... Rudder angle sensor

Claims (9)

The physical quantity is calculated based on the output signal of the vehicle behavior sensor (4) that generates an output signal corresponding to the physical quantity indicating the behavior of the vehicle, and the temperature detection signal is detected by detecting the temperature of the vehicle behavior sensor (4). The temperature of the vehicle behavior sensor (4) is calculated based on the temperature detection signals of the first temperature sensor (4a) and the redundant second temperature sensor (5a) to be output, and the zero of the physical quantity is obtained by removing the temperature drift. After the learning, the temperature drift from the zero point of the physical quantity is corrected based on the learning result, and a predetermined control intervention serving as a starting reference for the vehicle behavior control executed based on the corrected physical quantity A vehicle behavior sensor temperature correction device for setting a threshold (Th),
The temperature calculated from the temperature detection signals of the first and second temperature sensors (4a, 5a) is compared to determine whether the first and second temperature sensors (4a, 5a) are normal. An abnormality determination means (105);
Stop determination means (115) for determining whether or not the vehicle is stopped;
When the first and second temperature sensors (4a, 5a) are normal and when the vehicle is stopped, the stop time of learning 0 point of the physical quantity at the time of stop is learned. 0 point learning means (120);
Temperature storage means (125) for storing the temperature (Ty0) of the vehicle behavior sensor (4) when learning the zero point at the time of stop;
A temperature difference calculating means (135) for calculating a temperature change amount (ΔTy) from the temperature (Ty0) when learning the zero point at the time of the stop;
Threshold correction means (100, 140 to 160, 230 to 240) for correcting the predetermined control intervention threshold value (Th) according to the magnitude of the temperature change amount (ΔTy). A vehicle behavior sensor temperature correction device.   The threshold correction means (100, 140 to 160, 230 to 240) corrects the control intervention threshold (Ty) so that the change in the control intervention threshold (Ty) increases as the temperature change amount (ΔTy) increases. The vehicle behavior sensor temperature correction device according to claim 1. When learning the 0 point at the time of stop for the first time when the ignition switch is turned on when the first and second temperature sensors (4a, 5a) are normal, when learning the 0 point at the time of stop this time The temperature difference between the temperature of the vehicle behavior sensor (4) and the temperature (Ty0) when learning the zero point at the previous stop that was already stored in the temperature storage means (125) before turning on the ignition switch And whether or not the change of the 0 point to be learned from the previously learned 0 point is smaller than the threshold value set corresponding to these temperature differences is smaller and the 0 point deterioration has not occurred. A deterioration determining means (110) for determining;
The stop 0-point learning means (120) learns the 0 point to be learned this time as the stop 0 point when it is determined that the 0-point deterioration has not occurred. Or the vehicle behavior sensor temperature correction apparatus of 2 or 2 . The stop 0 point learning means (120) learns the stop 0 point each time when the vehicle stops after learning the stop 0 point for the first time after turning on the ignition switch,
The temperature storing means (125) also, each of learning the stop time 0 point, one of three claims 1, characterized in that to store the temperature (Ty0) when the learned the stop 0 points The vehicle behavior sensor temperature correction apparatus as described in one. The abnormality determining means (105) repeatedly determines whether or not the first and second temperature sensors (4a, 5a) are normal,
The stop 0-point learning means (120) is configured such that, even if the abnormality determination means (105) determines that the first and second temperature sensors (4a, 5a) are once normal, The vehicle behavior according to any one of claims 1 to 4 , wherein when it is determined that the second temperature sensor (4a, 5a) is not normal, learning of the zero point at the time of the stop is not performed. Sensor temperature correction device. Straight travel determination means (205) for determining whether the vehicle is traveling straight ahead;
Travel time 0 point learning means (210) for learning 0 point of travel, which is 0 point of the physical quantity during straight travel, when the vehicle is traveling straight ahead;
Vehicle speed storage means (215) for storing the speed (V0) of the vehicle when learning the zero point during travel;
Speed change amount calculating means (225) for calculating a speed change amount (ΔV) from the vehicle speed (V0) when learning the zero point at the time of traveling,
The threshold correction means (100, 140 to 160, 230 to 240) corrects the control intervention threshold (Th) according to the magnitude of the speed change amount (ΔV). 5. The vehicle behavior sensor temperature correction device according to claim 5. The threshold correction means (100, 140 to 160, 230 to 240) is configured to prevent the vehicle behavior control from starting before the zero point learning is performed after the ignition switch is turned on. The vehicle behavior sensor temperature correction device according to any one of claims 1 to 6 , wherein Th) is set to a maximum value. The threshold correction means (100, 140 to 160, 230 to 240) is a value used for correcting the control intervention threshold (Th), and the larger the value is set, the larger the control intervention threshold (Th) is. by setting the zero point drift margin is a value to be corrected to the value (Yd2), to any one of claims 1 to 7, characterized in that to correct the control intervention threshold value (Th) The vehicle behavior sensor temperature correction apparatus as described. The vehicle behavior sensor is a yaw rate sensor (4), and a value obtained by subtracting a temperature drift correction value (Yerror) from zero from an actual yaw rate that is an actual yaw rate obtained based on a detection signal of the yaw rate sensor (4). The vehicle skid prevention control is executed as the vehicle behavior control when the absolute value of the difference between the target yaw rate, which is a target yaw rate, is larger than the control intervention threshold (Th). The vehicle behavior sensor temperature correction apparatus according to any one of Items 1 to 8 .

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