JP2008143371A - Vehicle control device - Google Patents

Abstract

An object of the present invention is to provide a vehicle control device that suppresses erroneous determination in abnormality determination of a wheel speed sensor when turning radius reduction control is activated.
In a vehicle control apparatus 1 that performs turning control based on a driving force difference between left and right wheels in order to improve the turning performance of a vehicle, when turning control is performed, abnormality determination of wheel speed sensors 10, 11, 12, and 13 is performed. (For example, when turning control is performed, turning control is performed to change the abnormality determination threshold value of the wheel speed sensor to a value that makes it difficult to determine abnormality as the driving force difference between the left and right wheels increases.) (When the abnormality of the wheel speed sensor is stopped).
[Selection] Figure 1

Description

  The present invention relates to a vehicle control apparatus that performs rotational radius reduction control.

  The minimum turning radius of a vehicle is determined by the characteristics unique to the vehicle such as the wheel base and the maximum turning angle of the wheel. When performing a U-turn or parking in a narrow parking lot, turning with a turning radius smaller than the minimum turning radius may be required. In this case, the driver needs to perform a driving operation such as turning over. In particular, in a vehicle having a long wheelbase such as a minivan, the minimum turning radius is large, and thus the driver is required to perform a complicated driving operation in such a driving scene. Therefore, in order to improve the turning ability of the vehicle, a device (hereinafter referred to as a “rotation radius shortening control device”) has been developed that shortens the turning radius to be smaller than the minimum turning radius determined by the characteristics of the vehicle. In the turning radius shortening control device, a braking force is applied to the rear turning inner wheel at a low speed and a large turning angle, and a rotating moment is generated by a difference in driving force between the left and right wheels.

Since control devices such as a turning radius shortening control device and an ABS (Anti-lock Brake System) device perform control based on wheel speed and vehicle body speed, wheel speed sensors are attached to each wheel of the vehicle. When an abnormality occurs in the wheel speed sensor, the detection accuracy of the wheel speed by the wheel speed sensor decreases, and the control accuracy of each control device using the wheel speed also decreases. Therefore, abnormality determination is performed on the wheel speed sensor, and when an abnormality of the wheel speed sensor is detected, control in each control device is stopped and a warning lamp is turned on. As an abnormality determination method for a wheel speed sensor, for example, when a state in which a speed difference between a wheel speed of a determination target wheel and a reference speed (such as a vehicle body speed) is a predetermined speed difference or more continues for a predetermined time or more, It is determined that the wheel speed sensor of the wheel is abnormal. In particular, in the abnormality determination device described in Patent Document 1, in order to prevent the wheel speed sensor from being erroneously determined to be abnormal due to an unnatural behavior of the vehicle, the wheel is in a spin state or an uphill state. Does not perform speed sensor abnormality determination.
JP 2003-89350 A JP 2005-81935 A JP-A-11-170993 JP 2000-198462 A

  When the turning radius shortening control is operating, the wheel speed of the rear turning inner wheel becomes much lower than that of the other wheels due to the addition of the braking force to the rear turning inner wheel by the turning radius shortening control and the difference in turning inner wheel. For this reason, when an abnormality determination is made for the wheel speed sensor of the rear turning inner ring, the wheel speed sensor of the rear turning inner ring is erroneously determined to be abnormal because the wheel speed of the rear turning inner ring becomes extremely lower than the reference speed. End up. Even when the abnormality determination device described in Patent Document 1 is applied, the turning radius shortening control is not taken into consideration, so the abnormality determination for the wheel speed sensor of the rear turning inner wheel is performed, and the wheel speed sensor of the rear turning inner wheel is abnormal. Misjudged. As described above, when the wheel speed sensor is erroneously determined to be abnormal, control using the wheel speed sensor is stopped and an unnecessary warning lamp is lit even though the wheel speed sensor is operating normally.

  Then, this invention makes it a subject to provide the vehicle control apparatus which suppresses the misjudgment in abnormality determination of a wheel speed sensor, when rotation radius shortening control act | operates.

  The vehicle control device according to the present invention is a vehicle control device that performs a turn control based on a difference in driving force between left and right wheels in order to improve the turning performance of the vehicle. It is characterized by making it difficult to determine.

  In this vehicle control device, by turning control, a driving force difference is generated between the left and right wheels when turning the vehicle, thereby improving turning performance (small turning performance) and reducing the turning radius. In this turning control, a driving force difference is generated between the left and right wheels by applying a braking force by a brake or / and adjusting a driving force by a driving source such as an engine. In particular, in the vehicle control device, it is difficult to determine that the wheel speed sensor is abnormal in the abnormality determination of the wheel speed sensor during the turning control or at the timing of starting the turning control. That is, since a driving force difference is actively generated between the left and right wheels in order to shorten the turning radius, a wheel speed difference is generated between the wheels. Therefore, even though the wheel speed sensor is operating normally, there is a possibility that the wheel speed sensor is determined to be abnormal in the abnormality determination. Therefore, by making the determination of the abnormality of the wheel speed sensor not to be determined as abnormal than the normal abnormality determination, it is possible to suppress erroneous determination during turning control, and further, the wheel speed sensor due to erroneous determination of abnormality of the wheel speed sensor. Stopping the control to be used and unnecessary lighting of the warning lamp can be suppressed.

  In the vehicle control device of the present invention, when turning control is performed, the abnormality determination threshold value of the wheel speed sensor may be changed to a value that is less likely to be determined to be abnormal as the driving force difference between the left and right wheels increases.

  In this vehicle control device, the abnormality determination threshold value of the wheel speed sensor is changed to a value that is less likely to be determined as abnormal as the driving force difference between the left and right wheels is larger during turning control or at the timing at which turning control is started. That is, when the turning radius shortening control is being performed, the wheel speed difference between the wheels increases as the driving force difference between the left and right wheels increases, so the wheel speed sensor is easily determined to be abnormal. Therefore, by setting a higher threshold for determining that the wheel speed sensor is abnormal as the driving force difference between the left and right wheels becomes larger, erroneous determination of abnormality of the wheel speed sensor can be suppressed during turning control. If it is abnormal, it can be determined as abnormal.

  The vehicle control device of the present invention may be configured to correct the abnormality determination threshold value of the wheel speed sensor according to the brake control amount by the turning control when the turning control is performed.

  In this vehicle control device, in order to generate a driving force difference between the left and right wheels during turning control, a brake control amount is set and braking force is applied to the rear turning inner wheel or the like (a braking force difference is generated between the left and right wheels). . In the vehicle control device, it is difficult to determine an abnormality in the abnormality determination of the wheel speed sensor according to the brake control amount (the braking force difference between the left and right wheels) by the turning control during the turning control or at the timing of starting the turning control. In addition, the abnormality determination threshold value of the wheel speed sensor is corrected.

  The vehicle control device of the present invention may be configured to stop the abnormality determination of the wheel speed sensor when turning control is performed.

  In this vehicle control device, the abnormality determination of the wheel speed sensor is stopped during turning control or at the timing of starting turning control. Thus, during the turning control, the wheel speed sensor abnormality determination is not performed, so that erroneous determination of the wheel speed sensor abnormality can be reliably prevented.

  In the vehicle control device of the present invention, it is preferable that the turning control is performed when the vehicle speed is equal to or lower than the predetermined vehicle speed and the steering angle is equal to or higher than the predetermined steering angle.

  It is necessary to reduce the turning radius of the vehicle when driving at a low speed and a large steering angle, such as a U-turn or parking in a parking lot. Therefore, in this vehicle control device, turning control is performed when the vehicle speed is equal to or lower than the predetermined vehicle speed and the rudder angle is equal to or greater than the predetermined rudder angle, and the turning radius is reduced to improve the small turning performance.

  In the vehicle control device of the present invention, it is preferable to determine the driving force difference between the left and right wheels according to at least one of the accelerator operation amount and the steering angle in the turn control.

  In a vehicle, the driving force usually changes in accordance with the driver's accelerator operation amount (accelerator opening, etc.). On the other hand, in the turning control in the vehicle control device, a driving force difference is actively generated between the left and right wheels by adding braking force or the like. Thus, in this vehicle control device, the difference in driving force between the left and right wheels in turning control is determined according to the amount of accelerator operation, thereby suppressing the driver from feeling uncomfortable due to the difference in driving force between the left and right wheels. Further, the larger the steering angle, the smaller the turning radius is required. Therefore, in this vehicle control device, the turning ability is improved by determining the driving force difference between the left and right wheels in turning control according to the steering angle. Since the vehicle speed changes according to the accelerator operation amount, the accelerator operation amount includes the vehicle speed.

  In the present invention, when turning radius shortening control is being performed, it is difficult to determine that there is an abnormality in the wheel speed sensor abnormality determination. Can be suppressed.

  Hereinafter, an embodiment of a vehicle control device according to the present invention will be described with reference to the drawings.

  In the present embodiment, the vehicle control device according to the present invention is applied to a vehicle control device mounted on a rear wheel drive vehicle. The vehicle control device according to the present embodiment has at least a turning radius shortening control function. In addition, the vehicle control device according to the present embodiment also performs each process for the wheel speed sensor, and particularly performs invalidity determination and abnormality determination for the wheel speed sensor. In this embodiment, there are two forms. The first embodiment is a form in which it is difficult to determine invalidity and abnormality in wheel speed sensor invalidity determination and abnormality determination during turning radius reduction control. In the second embodiment, the invalidity determination and abnormality determination of the wheel speed sensor are stopped during the turning radius reduction control. The invalidity determination and the abnormality determination are the temporary determination, the abnormality determination is positioned as the main determination, and an abnormal state occurs when the invalid state continues for a predetermined time.

  With reference to FIGS. 1-4, the vehicle control apparatus 1 which concerns on 1st Embodiment is demonstrated. FIG. 1 is a configuration diagram of a vehicle control device according to the present embodiment. FIG. 2 is an explanatory diagram of the rotation radius shortening control. FIG. 3 is a diagram showing temporal changes in the wheel speed and the reference speed of the rear turning inner wheel when the vehicle is accelerated from a stopped state by full steering. FIG. 4 is a diagram showing the relationship between the amount of pressurization of the wheel cylinder of the rear turning inner wheel and the invalidity determination threshold value (correction value) of the wheel speed sensor according to the first embodiment.

  In the vehicle control device 1, in order to improve the turning performance at the time of turning, the turning radius is shortened by applying a braking force to the rear turning inner wheel at the time of turning at a low speed and a large steering angle. In particular, the vehicle control device 1 performs invalidity determination and abnormality determination during the rotation radius reduction control in order to suppress erroneous determination of invalidity determination and abnormality determination of the wheel speed sensor when the rotation radius reduction control is performed. Change the threshold. For this purpose, the vehicle control device 1 includes wheel speed sensors 10, 11, 12, 13, a rudder angle sensor 14, an accelerator opening sensor 15, wheel cylinder actuators 20, 21, a warning lamp 22 and an ECU [Electronic Control Unit] 31. I have.

  Wheel speed sensors 10, 11, 12, and 13 are sensors that are provided on the front right wheel, the front left wheel, the rear right wheel, and the rear left wheel, and detect the rotational speed of the wheel (number of pulses corresponding to the rotation of the wheel). The wheel speed sensors 10, 11, 12, and 13 detect the rotational speed of the wheel, and transmit the detected value to the ECU 31 as a wheel speed signal.

  The rudder angle sensor 14 is a sensor that is provided at a predetermined position in the steering mechanism from the steering wheel to the steered wheel and detects the rudder angle. The steering angle sensor 14 detects the steering angle, and transmits the detected value to the ECU 31 as a steering angle signal.

  The accelerator opening sensor 15 is a sensor that is provided on the accelerator pedal and detects the opening of the accelerator pedal. The accelerator opening sensor 15 detects the accelerator opening, and transmits the detected value to the ECU 31 as an accelerator opening signal.

  The wheel cylinder actuators 20 and 21 are actuators that are provided in each wheel cylinder of the rear right wheel and the rear left wheel and adjust the hydraulic pressure of the wheel cylinder. When the wheel cylinder actuators 20 and 21 receive the brake pressure control signal from the ECU 31, the wheel cylinder actuators 20 and 21 operate based on the brake pressure control signal to change the hydraulic pressure of the wheel cylinder.

  The warning lamp 22 is a lamp for notifying the abnormal state of the wheel speed sensors 10, 11, 12, and 13. The warning lamp 22 is turned on when an abnormality signal is received from the ECU 31.

  The ECU 31 is an electronic control unit that includes a CPU [Central Processing Unit], a ROM [Read Only Memory], a RAM [Random Access Memory], and the like, and performs overall control of the vehicle control device 1. The ECU 31 takes in the detection signals of the sensors 10 to 15 at regular time intervals. Further, the ECU 31 executes each program stored in the ROM by the CPU, so that a speed calculation process, an invalidity determination process, an abnormality determination process, a turning radius shortening control process, and a shortening control for the wheel speed sensor are performed at regular intervals. An hour wheel speed sensor corresponding process is performed, and a control signal is transmitted to the wheel cylinder actuators 20 and 21 and the warning lamp 22 as necessary.

  The speed calculation process will be described. The ECU 31 calculates the wheel speed for each wheel based on the number of pulses indicated by the wheel speed signal. Further, the ECU 31 calculates the vehicle body speed based on the wheel speeds of all the wheels.

  The invalidity determination process will be described. The ECU 31 calculates the difference (absolute value) between the wheel speed and the reference speed for each wheel, and determines whether the speed difference is equal to or greater than the invalidity determination threshold value. When it is determined that the speed difference is equal to or greater than the invalidity determination threshold, the ECU 31 determines that the wheel speed sensor is in an invalid state, and stops all applications (such as turning radius shortening control, ABS control, and traction control) that use the wheel speed sensor. The reference speed is the third fastest wheel speed of the vehicle body speed or each wheel speed of the four wheels. The invalidity determination threshold value is a speed difference at which the speed difference between the wheel speed and the reference speed is large and it can be determined that the wheel speed sensor that detects the wheel speed is not normal, and the basic value is set in advance by experiments or simulations. . As the invalidity determination threshold, a preset basic value is usually used, and a correction value set in the wheel speed sensor corresponding process during the shortening control is used during the rotation radius shortening control.

  The determination may be made not by the wheel speed but by the number of pulses detected by the wheel speed sensor. Moreover, when stopping an application, you may continue an application about the application which uses only the wheel speed sensor of another wheel, without using the wheel speed sensor determined to be an invalid state.

  The abnormality determination process will be described. The ECU 31 determines whether or not each wheel is determined to be in an invalid state in the invalidity determination process. When it is determined that the state is invalid, the ECU 31 measures the duration of the invalid state after it is determined to be invalid, and determines whether or not the duration exceeds the abnormality determination threshold. When it is determined that the duration is equal to or greater than the abnormality determination threshold, the ECU 31 determines that the wheel speed sensor is in an abnormal state, continues the stop of the application using the wheel speed sensor, and transmits an abnormality signal to the warning lamp 22. The abnormality determination threshold is a duration during which the invalid state continues to some extent and the wheel speed sensor can be clearly determined to be abnormal, and a basic value is set in advance by experiments or simulations. As the abnormality determination threshold value, a preset basic value is normally used, and a correction value set in the wheel speed sensor corresponding process during the shortening control is used during the rotation radius shortening control.

  The turning radius shortening control process will be described. The ECU 31 determines whether or not the vehicle is not stopped and the vehicle body speed is equal to or less than the vehicle speed at which the turning radius reduction control is started. The rotation radius shortening control start vehicle speed is a low vehicle speed for determining that the vehicle is traveling at a low speed, and is set in advance in consideration of a U-turn, a vehicle speed when parking, and the like. When it is determined that the vehicle is not stopped and the vehicle body speed is equal to or less than the rotation radius reduction control start vehicle speed, the ECU 31 determines whether or not the steering angle is equal to or greater than the rotation radius reduction control start steering angle. The turning radius shortening control start steering angle is a large steering angle for determining a state close to full steering, and is set in advance based on the maximum steering angle of the vehicle.

  When it is determined that the vehicle body speed is equal to or less than the vehicle speed at which the turning radius reduction control is started and the steering angle is greater than or equal to the steering angle at which the turning radius reduction control is started (when the operating condition for the turning radius reduction control is satisfied), the ECU 31 On the other hand, a target pressurization amount for applying braking force according to the accelerator opening is set, a brake pressure control signal for setting the target pressurization amount is set, and the brake pressure control signal is set to the wheel cylinder. Send to the actuator. The target pressurization amount is set to a larger value as the accelerator opening is larger, and is set using a map or the like showing the relationship between the target pressurization amount and the accelerator opening. In this way, the target pressurization amount is set according to the accelerator opening because the braking force is actively added on the vehicle side. Therefore, in order to suppress the uncomfortable feeling caused by the braking force, the target pressurizing amount is added as the driving force decreases. This is to reduce the braking force to be applied. The target pressurization amount may be set in consideration of the steering angle.

  The reason why the braking force is applied to the rear turning inner wheel will be described. By applying a braking force to the turning inner wheel at a low speed and a large steering angle, a rotational moment is generated that turns the vehicle inward. Due to this rotational moment, the arm length FL of the front turning inner ring FW and the arm length RL of the rear turning inner ring RW become as shown in FIG. The arm length is the length between the center of gravity axis (axis indicating the traveling direction of the center of gravity of the vehicle) A and each wheel, and the longer the arm length, the better the turning performance of the vehicle. Comparing the arm length FL of the front turning inner ring FW and the arm length RL of the rear turning inner ring RW, as can be seen from FIG. 2, the arm length RL is longer. In other words, when the braking force is applied to the rear turning inner wheel RW, the turning performance of the vehicle is improved and the minimum turning radius can be further shortened. Note that even if a braking force is applied to the front turning inner wheel FW, the turning performance of the vehicle is improved. Therefore, a braking force may also be applied to the front turning inner wheel FW.

  FIG. 3 shows the wheel speed WS (solid line) of the rear turning inner wheel when the turning radius shortening control is activated and the braking force is applied to the rear turning inner wheel when the vehicle accelerates from the stopped state by full steering. The time change of the reference speed BS (broken line) is shown. As can be seen from FIG. 3, both the wheel speed WS and the reference speed BS increase with acceleration, but since the braking force is applied to the rear turning inner wheel, the speed difference between the wheel speed WS and the reference speed BS (BS− WS) gradually increases. When this speed difference becomes equal to or greater than the invalidity determination threshold (basic value), the wheel speed sensor of the rear turning inner wheel is determined to be in an invalid state. An abnormal state is determined. Thus, even if the wheel speed sensor is operating normally, if the turning radius reduction control is operated, it is erroneously determined as an invalid state or an abnormal state. Therefore, the invalidity determination threshold value and the abnormality determination threshold value are corrected when the rotation radius shortening control is operated so that the speed difference of this level is not erroneously determined as an invalid state or an abnormal state.

  The wheel speed sensor handling process during shortening control will be described. The ECU 31 determines whether or not the turning radius shortening control is being performed (whether or not the operating condition of the turning radius shortening control is satisfied). When it is determined that the turning radius shortening control is in progress, the ECU 31 disables the control depending on the pressure applied to the wheel cylinder of the rear turning inner wheel in order to suppress erroneous determination in the invalid determination and abnormality determination of the wheel speed sensor of the rear turning inner wheel. The determination threshold value is corrected to a value larger than the basic value, and the abnormality determination threshold value is corrected to a value larger than the basic value. The greater the amount of pressure applied to the wheel cylinder of the rear turning inner wheel during the turning radius reduction control (that is, the greater the braking force applied to the rear turning inner wheel, and the greater the difference in driving force between the left and right wheels), the same body Since the degree of reduction in the wheel speed of the rear turning inner wheel with respect to the speed increases, the invalid determination threshold value and the abnormality determination threshold value are increased so that the invalid determination state and the abnormal state are not erroneously determined.

  The correction value for the invalidity determination threshold value and the correction value for the abnormality determination threshold value are set in advance by experiments or the like in consideration of how much the wheel speed decreases according to the amount of pressure applied to the wheel cylinder of the rear turning inner wheel. The correction value for the invalidity determination threshold value is set using a map or the like indicating the relationship between the invalidity determination threshold value and the pressurization amount. For example, as shown in FIG. 4, the invalid determination threshold correction value is set to a certain minimum guard value so that the correction value does not become excessive in a region where the pressurization amount is small, and the correction value in a region where the pressurization amount is large. A constant maximum guard value is set so that the pressure amount does not become excessive, and a value that increases linearly as the pressurization amount increases is set in the region between the pressurization amounts. The correction value for the abnormality determination threshold value may be a fixed value, or may be set according to the amount of pressurization such as the correction value for the invalid determination threshold value.

  Note that the abnormality determination threshold value may not be corrected with the basic value even when the rotation radius reduction control is activated. Because it is a condition that it is determined as an invalid state in order to be determined as an abnormal state, it is difficult to determine an invalid state by correcting the invalid determination threshold to a large value, and at the same time, an abnormal state This is because it becomes difficult to judge. That is, by correcting the invalid determination threshold value, the abnormality determination threshold value is also corrected.

  The operation of the vehicle control device 1 will be described with reference to FIG. Here, a case where the vehicle makes a U-turn from a state where the vehicle is stopped in the intersection will be described. In particular, the shortening control wheel speed sensor handling process of the ECU 31 will be described with reference to the flowchart of FIG. FIG. 5 is a flowchart showing the flow of the shortening control wheel speed sensor corresponding process in the ECU according to the first embodiment.

  Each wheel speed sensor 10, 11, 12, 13 detects the rotational speed of each wheel and transmits a wheel speed signal to the ECU 31. The steering angle sensor 14 detects the steering angle and transmits a steering angle signal to the ECU 31. The accelerator opening sensor 15 detects the accelerator opening and transmits an accelerator opening signal to the ECU 31.

  The ECU 31 receives detection signals from the sensors 10 to 15 at regular intervals. The ECU 31 calculates the wheel speed based on the wheel speed signal of each wheel, and further calculates the vehicle body speed from the wheel speed of each wheel.

  At certain time intervals, the ECU 31 determines whether the vehicle is not stopped, the vehicle body speed is equal to or less than the rotation radius reduction control start vehicle speed, and the steering angle is equal to or greater than the rotation radius reduction control start steering angle. When the vehicle is stopped in the intersection waiting for the oncoming vehicle to pass, the ECU 31 determines that the vehicle is stopped and does not start the turning radius reduction control.

  When the oncoming vehicle passes, the vehicle starts a U-turn and travels at a low speed and a large steering angle in the right turn direction. Then, the ECU 31 determines that the vehicle body speed is equal to or less than the rotation radius reduction control start vehicle speed and the steering angle is equal to or greater than the rotation radius reduction control start steering angle during traveling, and starts the rotation radius reduction control. The ECU 31 sets a brake pressure control signal for the rear turning inner wheel (right wheel) according to the accelerator opening, and transmits the brake pressure control signal to the wheel cylinder actuator 20. The rear right wheel cylinder actuator 20 operates in response to a brake pressure control signal to increase the hydraulic pressure of the wheel cylinder. As a result, a braking force is applied to the rear right wheel, and a rotational moment in the right direction is generated in the vehicle. As a result, the minimum turning radius of the vehicle is reduced during the U-turn. Incidentally, the rear right wheel has a braking force applied, so the wheel speed is lower than the other wheels.

  Further, at every predetermined time, the ECU 31 determines whether or not the turning radius reduction control is being performed (S10). When the vehicle is stopped in the intersection, the ECU 31 determines in S10 that the turning radius reduction control is not being performed, and the current process is terminated. When the vehicle starts a U-turn, the ECU 31 determines in S10 that the turning radius reduction control is being performed, and the invalidity determination threshold value is difficult to determine as an invalid state according to the amount of pressure applied to the wheel cylinder of the rear turning inner wheel (basic (S11), and the abnormality determination threshold value is changed to a value (a value larger than the basic value) that makes it difficult to determine an abnormal state (S12).

  In addition, when the vehicle is stopped within the intersection at regular intervals, the ECU 31 determines whether or not the speed difference between the wheel speed and the reference speed is greater than or equal to the invalid determination threshold (basic value) for all wheels. judge. When it is determined in S10 that the turning radius reduction control is being performed, the ECU 31 determines whether the speed difference between the wheel speed and the reference speed for the rear turning inner wheel has become equal to or greater than the invalidity determination threshold value (correction value) for each rear turning inner wheel. And for other wheels, it is determined whether or not the speed difference between the wheel speed and the reference speed is equal to or greater than the invalidity determination threshold (basic value). When it is determined that the speed difference is equal to or greater than the invalidity determination threshold, the ECU 31 determines that the wheel speed sensor is in an invalid state, and stops all applications using the wheel speed sensor. In particular, during the turning radius shortening control, the wheel speed of the rear turning inner wheel is lower than the other wheels and the speed difference is large, but the invalidity determination threshold (correction value) is also set to a large value. The speed difference is less than the invalidity determination threshold, and the invalid state is not determined.

  In addition, at every predetermined time, the ECU 31 determines whether or not all wheels are determined to be in an invalid state. If it is determined that the vehicle is in an invalid state, the ECU 31 measures the duration time of the invalid state when the vehicle is stopped in the intersection, and the duration time of all the wheels is equal to or greater than the abnormality determination threshold value (basic value). It is determined whether or not. When it is determined in S10 that the turning radius reduction control is being performed, the ECU 31 measures the duration time of the invalid state, and whether or not the duration time of the rear turning inner wheel is equal to or greater than the abnormality determination threshold value (correction value). It is determined, and it is determined whether or not the duration time of other wheels is equal to or greater than the abnormality determination threshold value (basic value). When it is determined that the duration is equal to or greater than the abnormality determination threshold, the ECU 31 determines that the wheel speed sensor is in an abnormal state, continues the stop of the application using the wheel speed sensor, and transmits an abnormality signal to the warning lamp 22. When the warning lamp 22 receives the abnormality signal, the lamp is turned on. In particular, during the turning radius shortening control, even if the wheel speed of the rear turning inner wheel temporarily decreases extremely and is temporarily determined to be invalid, the abnormality determination threshold (correction value) is set to a large value. Therefore, the duration time is less than the abnormality determination threshold value, and the abnormal state is not determined.

  According to the vehicle control device 1, when the turning radius reduction control is performed, the invalidity determination threshold value and the abnormality determination threshold value for the wheel speed sensor of the rear turning inner wheel are changed to values that are difficult to determine the invalid state and the abnormal state. Further, it is possible to suppress erroneous determination in invalidity determination and abnormality determination of the wheel speed sensor of the rear turning inner wheel. Therefore, the stop of the application using the wheel speed sensor due to the invalid determination of the wheel speed sensor or the erroneous determination of the abnormality determination and unnecessary lighting of the warning lamp can be suppressed. Further, when the wheel speed sensor of the rear turning inner wheel is actually abnormal, it can be determined as abnormal.

  With reference to FIG. 1, the vehicle control apparatus 2 which concerns on 2nd Embodiment is demonstrated. In the vehicle control device 2, the same reference numerals are given to the same configurations as those of the vehicle control device 1 according to the first embodiment, and the description thereof is omitted.

  The vehicle control device 2 differs from the vehicle control device 1 only in the handling of invalidity determination and abnormality determination for the wheel speed sensor during turning radius reduction control. In the vehicle control device 2, the wheel speed sensor of the rear turning inner wheel is disabled during the rotation radius reduction control in order to prevent erroneous determination of wheel speed sensor invalidity and abnormality determination when the rotation radius reduction control is performed. Judgment processing and abnormality judgment processing are stopped. Therefore, the vehicle control device 2 differs from the vehicle control device 1 only in the processing in the ECU 32.

  Compared with the ECU 31 according to the first embodiment, the ECU 32 performs the same process for the speed calculation process and the rotation radius shortening control process, but the invalidity determination process, the abnormality determination process, and the shortening control wheel speed sensor corresponding process. A different process is performed. Therefore, only the invalidity determination process, the abnormality determination process, and the shortening control wheel speed sensor handling process will be described.

  The invalidity determination process will be described. When the turning radius shortening control is not being performed, the ECU 32 determines the invalidity of the wheel speed sensor of each wheel by the same processing as in the first embodiment. On the other hand, when the turning radius shortening control is being performed, the ECU 32 stops the invalid determination of the wheel speed sensor for the rear turning inner wheel through the shortening control wheel speed sensor handling process. Note that the basic value is used for all invalidity determination thresholds.

  The abnormality determination process will be described. When the turning radius shortening control is not being performed, the ECU 32 determines whether or not the wheel speed sensor of each wheel is abnormal by the same processing as in the first embodiment. On the other hand, when the turning radius shortening control is being performed, the ECU 32 stops the abnormality determination of the wheel speed sensor for the rear turning inner wheel through the shortening control wheel speed sensor handling process. Note that all of the abnormality determination thresholds use basic values.

  The wheel speed sensor handling process during shortening control will be described. The ECU 32 determines whether or not the turning radius reduction control is being performed. When it is determined that the turning radius shortening control is being performed, the ECU 32 performs invalidity determination and abnormality determination of the wheel speed sensor of the rear turning inner wheel in order to prevent erroneous determination in the wheel speed sensor invalidity determination and abnormality determination of the rear turning inner wheel. Stop.

  The operation of the vehicle control device 2 will be described with reference to FIG. Here, a case where the vehicle makes a U-turn from a state where the vehicle is stopped in the intersection will be described. In particular, the shortening control wheel speed sensor handling process in the ECU 32 will be described with reference to the flowchart of FIG. FIG. 6 is a flowchart showing the flow of the shortening control wheel speed sensor corresponding process in the ECU according to the second embodiment.

  The vehicle control device 2 performs the same operations as those in the first embodiment on the various types of sensors 10 to 15 and the control process for shortening the rotation radius of the ECU 32, and thus the description of the operations is omitted.

  At certain time intervals, the ECU 32 determines whether or not the turning radius reduction control is being performed (S20). When the vehicle is stopped at the intersection, the ECU 32 determines in S20 that the turning radius reduction control is not being performed, and the current process is terminated. When the vehicle starts a U-turn, the ECU 32 determines in S20 that the turning radius reduction control is being performed, stops invalidity determination for the wheel speed sensor 12 of the rear turning inner wheel (S21), and also sets the wheel speed sensor 12 of the rear turning inner wheel. The abnormality determination for is stopped (S22).

  Further, when the vehicle stops within the intersection at regular intervals, the ECU 32 determines whether or not the speed difference between the wheel speed and the reference speed is equal to or greater than the invalidity determination threshold for all wheels. When it is determined in S20 that the turning radius reduction control is being performed, the ECU 32 stops the invalidity determination for the rear turning inner wheel, and the speed difference between the wheel speed and the reference speed for the other wheels becomes equal to or greater than the invalidity determination threshold value. It is determined whether or not. When it is determined that the speed difference is equal to or greater than the invalidity determination threshold, the same operation as in the first embodiment is performed. In particular, during the turning radius shortening control, the wheel speed of the rear turning inner wheel is lower than that of the other wheels and the speed difference is large. However, since the invalidity determination is not performed, the invalid state is not determined.

  Further, when the vehicle stops within the intersection at regular intervals, the ECU 32 determines whether or not all wheels are determined to be in an invalid state. When it is determined that the vehicle is in an invalid state, the ECU 32 measures the duration time of the invalid state and determines whether or not the duration time of all the wheels is equal to or greater than the abnormality determination threshold value. When it is determined in S20 that the turning radius reduction control is being performed, the ECU 32 stops the abnormality determination for the rear turning inner wheel and performs the same abnormality determination as described above for the other wheels. When it is determined that the duration is equal to or greater than the abnormality determination threshold, the same operation as that of the first embodiment is performed. In particular, during the turning radius reduction control, the abnormality determination is not performed for the rear turning inner wheel, so that it is not determined as an abnormal state.

  According to this vehicle control device 2, when the turning radius reduction control is performed, the invalidity determination and abnormality determination of the wheel speed sensor of the rear turning inner wheel are stopped by stopping the invalidity determination and abnormality determination of the rear turning inner wheel. An erroneous determination in the determination can be surely prevented. For this reason, it is possible to reliably prevent the application using the wheel speed sensor from stopping due to invalid determination of the wheel speed sensor or erroneous determination of the abnormality determination and unnecessary lighting of the warning lamp.

  As mentioned above, although embodiment which concerns on this invention was described, this invention is implemented in various forms, without being limited to the said embodiment.

  For example, although the present embodiment is applied to a rear wheel drive vehicle, it can also be applied to a four wheel drive vehicle and a front wheel drive vehicle.

  Further, in the present embodiment, the vehicle control device having the turning radius reduction control function is configured to perform each process for the wheel speed sensor. However, each process for the wheel speed sensor is performed by another device using a wheel speed sensor such as an ABS device. Alternatively, the processing device for the wheel speed sensor may be provided alone.

  In the present embodiment, the turning radius shortening control for applying the braking force to the rear turning inner wheel is applied. However, the present invention can also be applied to the turning radius shortening control for adding the braking force to the front turning inner wheel.

  Further, in the present embodiment, when the speed difference between the wheel speed of the wheel speed sensor and the reference speed is equal to or greater than the invalidity determination threshold, the invalidity determination that determines the invalid state and the invalid state when the invalid state continues for the abnormality determination threshold or more. Although the configuration is such that the abnormality determination is performed, only the abnormality determination may be performed, and other methods may be applied to the invalidity determination method and the abnormality determination method.

  In the present embodiment, the invalidity determination threshold and abnormality determination threshold of the wheel speed sensor are changed or the invalidity determination and abnormality determination of the wheel speed sensor are stopped during the rotation radius reduction control, but the rotation radius reduction control is started. It is good also as a structure which changes the invalid determination threshold value and abnormality determination threshold value of a wheel speed sensor, or stops the invalidity determination and abnormality determination of a wheel speed sensor at the timing to perform.

  In the first embodiment, the invalidity determination threshold is changed according to the pressurization amount of the wheel cylinder. However, the invalidity determination threshold value may be changed by a fixed amount, or according to a parameter other than the pressurization amount. The configuration may be changed.

It is a block diagram of the rotation radius shortening control apparatus which concerns on this Embodiment. It is explanatory drawing of rotation radius shortening control. It is a figure which shows the time change of the wheel speed and reference | standard speed of a rear turning inner wheel when it accelerates from a stop state by full steering. It is a figure which shows the relationship between the pressurization amount of the wheel cylinder of the rear turning inner ring which concerns on 1st Embodiment, and the invalid determination threshold value (correction value) of a wheel speed sensor. It is a flowchart which shows the flow of the wheel speed sensor corresponding | compatible process at the time of the shortening control in ECU which concerns on 1st Embodiment. It is a flowchart which shows the flow of the wheel speed sensor corresponding | compatible process at the time of the shortening control in ECU which concerns on 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Vehicle control apparatus 10, 11, 12, 13 ... Wheel speed sensor, 14 ... Steering angle sensor, 15 ... Accelerator opening sensor, 20, 21 ... Wheel cylinder actuator, 22 ... Warning lamp, 31, 32 ... ECU

Claims (6)

In a vehicle control device that performs turning control by a driving force difference between left and right wheels in order to improve turning performance of a vehicle,
When the turning control is performed, the vehicle control device makes it difficult for the wheel speed sensor to be determined to be abnormal in the abnormality determination.   2. The vehicle control device according to claim 1, wherein when the turning control is performed, the abnormality determination threshold value of the wheel speed sensor is changed to a value that is less likely to be determined as abnormal as the difference in driving force between the left and right wheels increases.   3. The vehicle control device according to claim 1, wherein when the turning control is performed, an abnormality determination threshold value of a wheel speed sensor is corrected according to a brake control amount by the turning control.   The vehicle control device according to claim 1, wherein the abnormality determination of the wheel speed sensor is stopped when the turning control is performed.   The vehicle control device according to any one of claims 1 to 4, wherein the turning control is performed when a vehicle speed is equal to or less than a predetermined vehicle speed and a steering angle is equal to or greater than a predetermined steering angle.   The vehicle control device according to any one of claims 1 to 5, wherein a driving force difference between the left and right wheels is determined in accordance with at least one of an accelerator operation amount and a steering angle in the turning control.

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