JP7123493B2 - Control device - Google Patents

Description

The present invention relates to a control device for a vehicle, in which each of a plurality of wheels of a vehicle is provided with a wheel speed sensor for detecting the rotational speed of the wheel.

The wheel speed sensor is, for example, provided with a plurality of magnetic poles of N pole and S pole alternately along the outer circumference of a rotating body that rotates with the wheel, and a magnetic detecting element such as a magnetoresistive element or a Hall element near the outer circumference of the rotating body. is arranged. When the wheel rotates, the magnetism fluctuation due to the movement of the magnetic pole accompanying the rotation is detected via the magnetism detecting element and output as a pulse signal. By counting the number of pulses per unit time, the rotation speed of the wheels can be obtained, and the vehicle speed, that is, the moving speed of the vehicle, can be derived.

The accuracy of vehicle speed detection with reference to the output signal of the wheel speed sensor decreases in a low speed range where the vehicle slows down at a speed of 10 km/h or less. In the low speed range, the number of pulses in the signal output by the wheel speed sensor decreases, ignoring the discrepancy between the vehicle speed and the number of pulses caused by improper pulse output due to wheel slippage on the road surface and vibration at the location where the wheel speed sensor is installed. Because I can't. Therefore, in the past, when the vehicle speed obtained by referring to the output signal of the wheel speed sensor was in the low speed range, the vehicle speed was uniformly regarded as zero.

On the other hand, in recent years, attempts have been made to install a system for assisting driving when parking a vehicle. A parking assist system requires highly accurate information on vehicle speed or wheel rotation speed in an extremely low speed range. For this reason, in a low-speed range where the vehicle runs slowly, the accuracy of the vehicle speed information based on the output signal of the wheel speed sensor is increased so that it can be used. Specifically, the output signal of the wheel speed sensor associated with the target wheel is compared with the output signal of the wheel speed sensor associated with the other wheels, or the output signal of the wheel speed sensor associated with the target wheel is compared. By comparing the amount of change per unit time in the rotation speed of the target wheel that is learned with reference to the threshold value, whether or not the output signal of the wheel speed sensor associated with the target wheel is mixed with disturbance is determined (refer to the patent document below).

JP 2018-036155 A

According to the above prior art, the number of pulses output by the wheel speed sensor associated with any wheel other than the target wheel within the most recent unit time is 0, and the wheel speed sensor associated with the target wheel If the number of pulses output within the same unit time exceeds a predetermined threshold, it is determined that the output signal of the wheel speed sensor attached to the target wheel contains disturbance.

However, if the vehicle is suddenly braked before stopping, the braking force applied to each wheel becomes uneven, and an event may occur in which only some of the wheels are locked and stop rotating. As a result, the control device erroneously determines that the output signal of the wheel speed sensor associated with the unlocked wheel is mixed with a disturbance, and the vehicle is actually moving, but the amount of movement is may be misidentified as 0.

The present invention has been made for the first time by paying attention to the above problems, and it is intended to further improve the accuracy of vehicle speed information based on the output signal of the wheel speed sensor in a low speed range where the vehicle is traveling slowly. purpose.

In the present invention, in a vehicle in which each of a plurality of wheels of the vehicle is provided with a wheel speed sensor for detecting the rotational speed of the wheel, the output signal of the wheel speed sensor attached to the target wheel and the output signal of the other wheels The amount of change per unit time in the rotation speed of the target wheel, which is learned by comparing with the output signal of the accompanying wheel speed sensor or by referring to the output signal of the wheel speed sensor accompanying the target wheel is compared with the threshold value to determine whether or not the output signal of the wheel speed sensor attached to the target wheel is mixed with the disturbance. It outputs the value of the rotation speed of the wheel set to the wheel speed sensor, or outputs the judgment result of whether or not disturbance is mixed in the output signal of the wheel speed sensor. A control device is configured to determine that the output signal of the sensor is not mixed with disturbance.

In addition, in the present invention, in a vehicle equipped with a wheel speed sensor for detecting the rotational speed of each of a plurality of wheels provided in the vehicle, the output signal of the wheel speed sensor attached to the target wheel and the other By comparing with the output signal of the wheel speed sensor attached to the wheel, or by referring to the output signal of the wheel speed sensor attached to the target wheel, the rotation speed of the target wheel per unit time By comparing the amount of change with a threshold value, it is determined whether or not the output signal of the wheel speed sensor associated with the target wheel is mixed with disturbance, and the output signal of the wheel speed sensor that has been determined not to be mixed with disturbance. or output the determination result of whether or not disturbance is mixed in the output signal of the wheel speed sensor, and only when the vehicle is stopped. , a control device for determining whether or not an output signal of a wheel speed sensor is mixed with a disturbance.

ADVANTAGE OF THE INVENTION According to this invention, the accuracy of the information of the vehicle speed based on the output signal of a wheel speed sensor can be improved further in the low-speed area where a vehicle runs slowly.

1 is a block diagram showing the configuration of a control device according to one embodiment of the present invention; FIG. FIG. 4 is a flowchart showing an example of the procedure of processing executed by the control device of the embodiment; FIG. 4 is a flowchart showing an example of the procedure of processing executed by the control device of the embodiment; FIG. 4 is a flowchart showing an example of the procedure of processing executed by the control device of the embodiment;

One embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of a vehicle control device 1 of this embodiment. The wheel speed sensors 21, 22, 23, 24 attached to each wheel FR, RR, FL, RL of the vehicle are known ones used for ABS (Antilock Brake System). Each wheel speed sensor 21, 22, 23, 24 outputs a number of pulses proportional to the amount of rotation (angle of rotation or number of rotations) of the target wheels FR, RR, FL, RL. By counting the number of pulses per unit time, the rotational speeds of the target wheels FR, RR, FL, and RL can be obtained. As a result, it is possible to derive the vehicle speed.

The control device 1 of this embodiment is mainly composed of an ECU (Electronic Control Unit), which is a microcomputer system having a processor, a main memory, an auxiliary storage device (flash memory, etc.), an input/output interface, and the like. The ECU 1 may be the same as an ABS-ECU that controls the ABS or a VSC-ECU that controls a vehicle stability control (VSC), which is a side slip prevention device.

Programs to be executed by the processor are stored in advance in the auxiliary storage device of the ECU 1 . During its execution, the program is read from the secondary storage device into main memory and decoded by the processor. The ECU 1, which is a control device, controls the right front wheel disturbance determination unit 11, the right rear wheel disturbance determination unit 12, the left front wheel disturbance determination unit 13, the left rear wheel disturbance determination unit 14, and the right wheel rotation speed output unit 15 shown in FIG. , and the left wheel rotational speed output unit 16.

The right front wheel disturbance determination unit 11 determines whether or not the output signal of the wheel speed sensor 21 attached to the right front wheel FR of the vehicle includes disturbance. A disturbance means that the number of pulses output by the wheel speed sensors 21, 22, 23, and 24 increases or decreases from the number of pulses corresponding to the actual vehicle speed. Disturbance factors include slippage of the wheels FR, RR, FL, and RL on the road surface, and vibration of the locations where the wheel speed sensors 21, 22, 23, and 24 are installed, causing the wheel speed sensors 21, 22, 23, and 24 to outputting an illegal pulse. The right rear wheel disturbance determination unit 12 determines whether or not the output signal of the wheel speed sensor 22 associated with the right rear wheel RR of the vehicle is mixed with disturbance. The left front wheel disturbance determination unit 13 determines whether or not the output signal of the wheel speed sensor 23 attached to the left front wheel FL of the vehicle includes disturbance. Then, the left rear wheel disturbance determination unit 14 determines whether or not the output signal of the wheel speed sensor 24 attached to the left rear wheel RL of the vehicle contains disturbance.

A method for determining whether or not the output signals of the wheel speed sensors 21, 22, 23, and 24 are mixed with disturbance by the disturbance determination units 11, 12, 13, and 14 will be specifically described. Whether or not the output signals of the wheel speed sensors 21, 22, 23, and 24 are mixed with disturbance is determined according to the following three conditions (I), (II), and (III):
(I) The absolute value of the difference in the number of pulses output by each of the three wheel speed sensors attached to the three wheels including the target wheel within the most recent unit time (for example, 50 milliseconds) is a predetermined threshold Is it within the following?
For example, in order to determine whether or not the output signal of the wheel speed sensor 21 attached to the right front wheel FR contains a disturbance, the number of pulses output by the wheel speed sensor 21 within the most recent unit time The number of pulses output within the same unit time by the wheel speed sensor 22 associated with the rear wheel RR and the number of pulses output within the same unit time by the wheel speed sensor 23 associated with the left front wheel FL are counted. Then, the absolute value of the difference obtained by subtracting the number of pulses output by the wheel speed sensor 22 associated with the rear right wheel RR from the number of pulses output by the wheel speed sensor 21 associated with the front right wheel FR is compared with a threshold value. Also, the absolute value of the difference obtained by subtracting the number of pulses output by the wheel speed sensor 23 associated with the front left wheel FL from the number of pulses output by the wheel speed sensor 21 associated with the front right wheel FR is compared with the threshold. If the absolute value of any difference is equal to or less than the threshold value, it is determined that the output signal of the wheel speed sensor 21 associated with the right front wheel FR is not mixed with disturbance. On the other hand, if the absolute value of any difference exceeds the threshold, it is determined that the output signal of the wheel speed sensor 21 is mixed with disturbance.
Alternatively, the number of pulses output by the wheel speed sensor 21 within the most recent unit time, the number of pulses output within the same unit time by the wheel speed sensor 22 attached to the right rear wheel RR, and the wheel attached to the left front wheel FL The value of the difference obtained by subtracting the minimum number of pulses from the maximum number of pulses output by the speed sensor 23 within the same unit time may be compared with the threshold value. If the difference value is equal to or less than the threshold value, it is determined that the output signal of the wheel speed sensor 21 associated with the right front wheel FR is not mixed with disturbance. On the other hand, if the difference value exceeds the threshold value, it is determined that the output signal of the wheel speed sensor 21 is mixed with disturbance.

(II) The number of pulses output by the wheel speed sensor attached to the target wheel within the most recent unit time (for example, 50 milliseconds from the time 50 milliseconds before the current time to the current time), and past units The absolute value of the difference between the number of pulses output within a period of time (for example, 50 milliseconds from the time 100 milliseconds before the current time to the time 50 milliseconds before the current time) falls below a predetermined threshold. Whether or not there is (if it is settled, disturbance is not mixed; if it is not settled, disturbance is mixed)
For example, in order to determine whether or not the output signal of the wheel speed sensor 21 attached to the right front wheel FR contains a disturbance, the number of pulses output by the wheel speed sensor 21 within the most recent unit time, The number of pulses output by the same wheel speed sensor 21 within the past unit time is also counted. Then, the value of the difference obtained by subtracting the smaller one from the larger one of the two pulse numbers is compared with the threshold value. If the difference value is equal to or less than the threshold value, it is determined that the output signal of the wheel speed sensor 21 associated with the right front wheel FR is not mixed with disturbance. On the other hand, if the difference value exceeds the threshold value, it is determined that the output signal of the wheel speed sensor 21 is mixed with disturbance.

(III) When the number of pulses output by the wheel speed sensor associated with any wheel other than the target wheel in the most recent unit time (for example, 100 milliseconds) is 0, associated with the target wheel Whether or not the number of pulses output by the wheel speed sensor within the same unit time is within a predetermined threshold value (if it is, there is no disturbance; if it is not, there is disturbance)
For example, in order to determine whether or not the output signal of the wheel speed sensor 21 attached to the right front wheel FR contains a disturbance, the number of pulses output by the wheel speed sensor 21 within the most recent unit time The number of pulses output within the same unit time by the wheel speed sensor 22 associated with the rear wheel RR, the number of pulses output within the same unit time by the wheel speed sensor 23 associated with the front left wheel FL, and the number of pulses associated with the rear left wheel RL The number of pulses output by the wheel speed sensor 24 within the same unit time is counted. Further, when the number of pulses output by the wheel speed sensors 22, 23, 24 attached to any of the wheels RR, FL, RL other than the right wheel FR within the same unit time is 0, the right wheel FR The number of pulses output within the same unit time by the wheel speed sensor 21 associated with is compared with a threshold value. If the number of pulses is equal to or less than the threshold, it is determined that the output signal of the wheel speed sensor 21 associated with the right front wheel FR is not mixed with disturbance. It is determined that the output signal of the wheel speed sensor 21 is mixed with disturbance.

Examining the success or failure of the above conditions (I) and (III) is based on the output signals of the wheel speed sensors 21, 22, 23, and 24 associated with the target wheels FR, RR, FL, and RL and the other wheels FR. , RR, FL, RL with the output signals of the wheel speed sensors 21, 22, 23, 24 associated therewith. Further, examining the success or failure of condition (II) is performed by referring to the output signals of the wheel speed sensors 21, 22, 23, 24 attached to the wheels FR, RR, FL, RL of interest. It means comparing the amount of change per unit time of the rotation speed of the wheels FR, RR, FL, RL with a threshold value.

The right wheel rotation speed output unit 15 outputs information about the rotation speed of the right front wheel FR based on the output signal of the wheel speed sensor 21 attached to the right front wheel FR. However, as will be described later, when the output signal of the wheel speed sensor 21 attached to the right front wheel FR is mixed with a disturbance, the right rear Information on the rotational speed of the wheel RR may be output. Further, the left wheel rotation speed output unit 16 outputs information on the rotation speed of the left front wheel FL based on the output signal of the wheel speed sensor 23 attached to the left front wheel FL. However, when the output signal of the wheel speed sensor 23 attached to the left front wheel FL is mixed with the disturbance, the rotation speed of the left rear wheel RL is calculated based on the output signal of the wheel speed sensor 24 attached to the left rear wheel RL. information may be output.

2 to 4 show an example of the procedure of processing executed by the ECU 1 according to the program. First, the right front wheel disturbance determination unit 11 examines whether the above conditions (I), (II) and (III) are met with respect to the right front wheel FR (steps S1, S2 and S4). Then, when it is assumed that disturbance is mixed in by at least one of the conditions (I), (II), and (III), the output signal of the wheel speed sensor 21 associated with the right front wheel FR is It is determined that there is disturbance (step S5). Otherwise, it is determined that the output signal of the wheel speed sensor 21 associated with the right front wheel FR is not mixed with disturbance (step S6).

Next, the right rear wheel disturbance determination unit 12 examines whether the conditions (I), (II) and (III) are met with respect to the right rear wheel RR (steps S7, S8 and S10). Then, when it is determined that disturbance is mixed in by at least one of the conditions (I), (II), and (III), the output signal of the wheel speed sensor 22 associated with the right rear wheel RR is (step S11). Otherwise, it is determined that the output signal of the wheel speed sensor 22 associated with the right rear wheel RR is not mixed with disturbance (step S12).

In addition, the left front wheel disturbance determination unit 13 examines whether the conditions (I), (II) and (III) are met with respect to the left front wheel FL (steps S13, S14 and S16). Then, when it is determined that a disturbance is mixed due to at least one of the conditions (I), (II), and (III), the output signal of the wheel speed sensor 23 associated with the left front wheel FL is It is determined that there is a disturbance (step S17). Otherwise, it is determined that the output signal of the wheel speed sensor 23 associated with the left front wheel FL is not mixed with disturbance (step S18).

Further, the left rear wheel disturbance determination unit 14 examines whether the conditions (I), (II) and (III) are established for the left rear wheel RL (steps S19, S20 and S22). Then, when it is determined that disturbance is mixed in by at least one of the conditions (I), (II), and (III), the output signal of the wheel speed sensor 24 attached to the left rear wheel RL (step S23). Otherwise, it is determined that the output signal of the wheel speed sensor 24 associated with the left rear wheel RL is not mixed with disturbance (step S24).

Thus, the right wheel rotation speed output unit 15 refers to the output signal of the wheel speed sensor 21 associated with the right front wheel FR according to the determination results of the right front wheel disturbance determination unit 11 and the right rear wheel disturbance determination unit 12. , or to refer to the output signal of the wheel speed sensor 22 attached to the right rear wheel RR. That is, if the output signal of the wheel speed sensor 21 associated with the front right wheel FR is not mixed with a disturbance (step S25), the wheel speed sensor 21 associated with the front right wheel FR detects the latest unit time (for example, 50 milliseconds). ) is output as a value indicative of the rotation speed of the right front wheel FR and thus the vehicle speed (step S26). At the same time, it also outputs information indicating the determination result that the output signal of the wheel speed sensor 21 is not mixed with disturbance (may be a reset of a 1-bit flag).

On the other hand, if the output signal of the wheel speed sensor 21 attached to the right front wheel FR is mixed with the disturbance, but the output signal of the wheel speed sensor 22 attached to the right rear wheel RR is not mixed with the disturbance ( Step S27), the number of pulses output by the wheel speed sensor 22 attached to the right rear wheel RR within the most recent unit time (50 milliseconds) is output as a substitute value indicating the rotation speed of the right front wheel FR (step S27). S28). At the same time, it also outputs information indicating the determination result that the output signal of the wheel speed sensor 22 is not mixed with disturbance (may be a reset of a 1-bit flag). The reason why the outputs of the sensors 21 and 23 on the front wheel side are prioritized is that when the vehicle is driven for parking, the front wheels FR and FL, which are steered wheels, are more likely to move than the rear wheels RR and RL. This is because the radius of the trajectory (turning radius) is large and the amount of rotation or rotation speed is also large.

If the output signal of the wheel speed sensor 21 associated with the front right wheel FR and the output signal of the wheel speed sensor 22 associated with the rear right wheel RR are mixed with disturbance, the wheel speed sensor associated with the front right wheel FR 21 outputs the number of pulses output within the most recent unit time (50 milliseconds) as a value tentatively suggesting the rotation speed of the right front wheel FR (step S29). However, since it is expected that this rotational speed value contains an error, information indicating the determination result that the output signal of the wheel speed sensor 21 contains a disturbance (a 1-bit flag set may be present) is also output.

In steps S26, S28 and S29, the value of the rotation speed of the right front wheel FR and information on the determination result are written in the memory or auxiliary storage device of the ECU 1 and/or via an in-vehicle network such as CAN (Controller Area Network). It is transmitted to other communicably connected ECUs, such as an ECU that controls an internal combustion engine or an electric motor mounted as a driving source of a vehicle, or an ECU that constitutes a parking assistance or other driving assistance system.

Similarly, the left wheel rotation speed output unit 16 refers to the output signal of the wheel speed sensor 23 associated with the left front wheel FL according to the determination result of the left front wheel disturbance determination unit 13 and the left rear wheel disturbance determination unit 14, or Alternatively, it is selected whether to refer to the output signal of the wheel speed sensor 24 associated with the left rear wheel RL. That is, if the output signal of the wheel speed sensor 23 associated with the left front wheel FL is not mixed with the disturbance (step S30), the wheel speed sensor 23 associated with the left front wheel FL is detected within the most recent unit time (50 milliseconds). is output as a value indicative of the rotation speed of the left front wheel FL and thus the vehicle speed (step S31). At the same time, it also outputs information indicating the determination result that the output signal of the wheel speed sensor 23 is not mixed with disturbance (may be a reset of a 1-bit flag).

On the other hand, if the output signal of the wheel speed sensor 23 associated with the left front wheel FL is mixed with the disturbance, but the output signal of the wheel speed sensor 24 associated with the left rear wheel RL is not mixed with the disturbance ( Step S32), the number of pulses output by the wheel speed sensor 24 associated with the left rear wheel RL within the most recent unit time (50 milliseconds) is output as a substitute value indicating the rotational speed of the left front wheel FL (step S32). S33). At the same time, it also outputs information indicating the determination result that the output signal of the wheel speed sensor 24 is not mixed with disturbance (may be a reset of a 1-bit flag).

If the output signal of the wheel speed sensor 23 associated with the front left wheel FL and the output signal of the wheel speed sensor 24 associated with the rear left wheel RL are mixed with disturbance, the wheel speed sensor associated with the front left wheel FL 23 outputs the number of pulses output within the most recent unit time (50 milliseconds) as a value tentatively suggesting the rotation speed of the left front wheel FL (step S34). However, since it is expected that this rotational speed value contains an error, information indicating the determination result that the output signal of the wheel speed sensor 23 contains a disturbance (a 1-bit flag set may be present) is also output.

In steps S31, S33 and S34, the value of the rotation speed of the left front wheel FL and the information of the determination result are written in the memory or auxiliary storage device of the ECU 1 and/or connected via an in-vehicle network such as CAN so as to be communicable. transmit to other ECUs that are

Incidentally, the above condition (III) tries to detect an event in which the wheel speed sensors 21, 22, 23, and 24 output pulse signals due to disturbances even though the vehicle is actually stopped. It is. Therefore, the length of the unit time (100 milliseconds) in examining the success or failure of condition (III) is the length of the unit time in examining the success or failure of conditions (I) and (II), and the repetition cycle of steps S1 to S34. (both are 50 milliseconds), it is preferable to set longer.

Of course, the ECU 1 of this embodiment does not always determine whether or not the output signals of the wheel speed sensors 21, 22, 23, and 24 contain disturbances. When the vehicle is suddenly braked before stopping, the braking force applied to each wheel FR, RR, FL, RL becomes uneven, and only some of the wheels FR, RR, FL, RL are locked and stop rotating. An event like this can occur. As a result, the number of pulses output from the wheel speed sensors 21, 22, 23, 24 attached to the locked wheels FR, RR, FL, RL becomes 0, but the wheels FR, RR, The wheel speed sensors 21, 22, 23, 24 associated with FL, RL still continue to output pulses. In spite of this, since it is erroneously determined that the output signals of the wheel speed sensors 21, 22, 23, and 24 are mixed with disturbance, the amount of movement of the vehicle that is actually moving is erroneously determined to be 0. There is a risk that it will be lost.

Therefore, in the present embodiment, the determination processing (steps S4, S10, S16, and S22) for determining whether or not the output signals of the wheel speed sensors 21, 22, 23, and 24 contain disturbances based on condition (III) is performed. Only when it is deemed necessary (steps S3, S9, S15 and S21) to execute the determination process, otherwise the determination process based on condition (III) is canceled and the wheel speed sensors 21, 22, 23, It is determined that the output signal of 24 has no disturbance (steps S6, S12, S18 and S24).

The reason why the ECU 1 determines whether or not the output signals of the wheel speed sensors 21, 22, 23, 24 contain disturbances based on the condition (III) is when the vehicle is not suddenly braked. Or when the vehicle is parked. As described above, when the vehicle is suddenly braked, there is a possibility that the output signals of the wheel speed sensors 21, 22, 23, and 24 may be erroneously determined to be subject to disturbance even though the output signals are not. Further, disturbance due to vibration of the installation locations of the wheel speed sensors 21, 22, 23, and 24, that is, output of improper pulses, becomes a problem while the vehicle is stopped. Due to such a disturbance, the vehicle, which is actually stopped, is misidentified as moving.

In steps S3, S9, S15 and S21, the ECU 1, for example,
[A] The driver is stepping on the brake pedal, and the brake fluid pressure (brake back pressure) applied to the vehicle brake device (disc brake caliper or drum brake wheel cylinder) exceeds a predetermined threshold. , and if the absolute value of deceleration along the longitudinal direction of the vehicle exceeds a predetermined threshold value, it is assumed that the vehicle is suddenly braked by the driver's operation, and determination processing based on condition (III) is executed. Cancel this without acknowledging the need.
Whether or not the brake pedal is stepped on can be known through the stop lamp switch 3, a sensor for detecting the amount of depression of the brake pedal, or the like. The magnitude of the brake fluid pressure can be obtained through a hydraulic pressure sensor 4 installed on the hydraulic circuit. The magnitude of deceleration of the vehicle can be obtained via the acceleration sensor 5 .

[B] The brake pedal is not depressed by the driver, but the vehicle is required to be automatically braked, the brake fluid pressure applied to the vehicle brake device exceeds a predetermined threshold, and the front and rear of the vehicle If the absolute value of the deceleration along the direction exceeds a predetermined threshold, it is assumed that the vehicle is being braked abruptly by automatic braking that does not depend on the driver's operation, and judgment processing based on condition (III) is executed. Cancel this without acknowledging the need.
Whether or not automatic braking is requested can be learned by communicating with the ECU 6 that controls the collision damage mitigation brake (collision avoidance support brake) system, adaptive cruise control system, level 3 automatic driving system, or the like.

[C] If the vehicle speed remains below a threshold value of 0 or close to 0 for a predetermined period of time or longer, it is assumed that the vehicle is stopped, and it is necessary to execute determination processing based on condition (III). is recognized, and the determination process is executed.

The ECU 1 executes determination processing based on condition (III) of steps S4, S10, S16 and S22 on the condition that neither of the above [A] and [B] is satisfied. And/or, on the condition that the above [C] is satisfied, the determination processing based on the condition (III) of steps S4, S10, S16 and S22 is executed.

The ECU 1 repeatedly executes the above-described steps S1 to S34 every unit time (for example, 50 milliseconds).

In this embodiment, wheel speed sensors 21, 22, 23, and 24 for detecting the rotational speeds of the wheels FR, RR, FL, and RL are attached to each of the plurality of wheels FR, RR, FL, and RL provided in the vehicle. In the vehicle, the output signals of the wheel speed sensors 21, 22, 23, and 24 associated with the target wheels FR, RR, FL, and RL and the wheel speed sensors 21 associated with the other wheels FR, RR, FL, and RL, by comparing (conditions (I) and (III)) with the output signals of 22, 23, 24 or wheel speed sensors 21, 22, 23, 24 associated with the wheels FR, RR, FL, RL of interest. By comparing the amount of change per unit time in the rotation speed of the target wheels FR, RR, FL, and RL with reference to the output signal of the target wheels FR, wheel speed sensors 21, 22 that determine whether or not disturbance is mixed in the output signals of the wheel speed sensors 21, 22, 23, 24 attached to RR, FL, RL, and determine that the disturbance is not mixed; 23, 24 based on the output signals of the wheels FR, RR, FL, RL, or whether the output signals of the wheel speed sensors 21, 22, 23, 24 are mixed with disturbance. A control device 1 is configured to output the determination result.

In addition, when the vehicle is being braked suddenly (condition [A] or [B]), the control device 1 of the present embodiment does not cause disturbance to the output signals of the wheel speed sensors 21, 22, 23, and 24. It is determined that there is no contamination. Alternatively, only when the vehicle is stopped (condition [C]), it is determined whether or not the output signals of the wheel speed sensors 21, 22, 23, 24 contain disturbance.

According to this embodiment, the accuracy of vehicle speed information based on the output signals of the wheel speed sensors 21, 22, 23, and 24 can be further enhanced in a low speed range where the vehicle is slowing down. It is also possible to detect a low vehicle speed of 10 km/h or less and provide the information to the ECU 7 of the parking assistance system.

The present invention is not limited to the embodiments detailed above. For example, in the right wheel rotation speed output unit 15, the number of pulses output by the wheel speed sensor 21 or the wheel speed sensor 22 within a unit time (for example, 50 milliseconds) is integrated for a predetermined time, and the integrated value is calculated as the right front wheel. It may be output as a value suggesting the rotational speed of the FR or the vehicle speed. In this case, the output pulse number of the wheel speed sensor 21 associated with the right front wheel FR is used for each of a plurality of unit times included in the most recent predetermined time, or the output of the wheel speed sensor 22 associated with the right rear wheel RR is used. Select whether to use the number of pulses. That is, if it is determined that the output signal of the wheel speed sensor 21 does not contain any disturbance for a certain unit time, the number of output pulses of the wheel speed sensor 21 is added to the integrated value as the number of pulses in that unit time, and the wheel speed If it is determined that the output signal of the wheel speed sensor 22 is not mixed with the disturbance while the output signal of the sensor 21 is mixed, the number of output pulses of the wheel speed sensor 22 is integrated as the number of pulses per unit time. Renormalize to value. Alternatively, if it is determined that the output signals of both wheel speed sensors 21 and 22 are mixed with disturbance, the number of output pulses of the wheel speed sensor 21 is added to the integrated value as the number of pulses per unit time.

Similarly, in the left wheel rotation speed output unit 16, the number of pulses output by the wheel speed sensor 23 or the wheel speed sensor 24 within a unit time (for example, 50 milliseconds) is integrated for a predetermined time, and the integrated value is It may be output as a value suggesting the rotation speed of the FL or the vehicle speed. In this case, the output pulse number of the wheel speed sensor 23 associated with the left front wheel FL is used for each of a plurality of unit times included in the most recent predetermined time, or the output of the wheel speed sensor 24 associated with the left rear wheel RL is used. Select whether to use the number of pulses. That is, if it is determined that the output signal of the wheel speed sensor 23 does not contain any disturbance for a certain unit time, the number of output pulses of the wheel speed sensor 23 is added to the integrated value as the number of pulses in that unit time, and the wheel speed If it is determined that the output signal of the wheel speed sensor 24 is not mixed with the disturbance while the output signal of the sensor 23 is mixed, the number of output pulses of the wheel speed sensor 24 is integrated as the number of pulses per unit time. Renormalize to value. Alternatively, if it is determined that the output signals of both wheel speed sensors 23 and 24 are mixed with disturbance, the number of output pulses of the wheel speed sensor 23 is added to the integrated value as the number of pulses per unit time.

In addition, the specific configuration of each part, the contents of processing, etc. can be modified in various ways without departing from the scope of the present invention.

INDUSTRIAL APPLICABILITY The present invention can be used for controlling an internal combustion engine mounted on a vehicle or the like.

1... Control device (ECU)
21, 22, 23, 24... wheel speed sensors FR, RR, FL, RL... wheels provided in the vehicle

Claims (2)

A vehicle equipped with a wheel speed sensor for detecting the rotational speed of each of a plurality of wheels of the vehicle,
By comparing the output signal of the wheel speed sensor associated with the target wheel with the output signal of the wheel speed sensor associated with the other wheels, or referring to the output signal of the wheel speed sensor associated with the target wheel. By comparing the amount of change per unit time in the rotation speed of the target wheel, which is learned by the controller, with a threshold value, it is determined whether or not the output signal of the wheel speed sensor associated with the target wheel is mixed with disturbance. ,
It outputs the value of the rotation speed of the wheel based on the output signal of the wheel speed sensor determined that there is no disturbance, or outputs the determination result of whether or not the output signal of the wheel speed sensor is mixed with disturbance. which outputs
A control device that determines that the output signal of the wheel speed sensor is free from disturbance when the vehicle is being braked suddenly. A vehicle equipped with a wheel speed sensor for detecting the rotational speed of each of a plurality of wheels of the vehicle,
By comparing the output signal of the wheel speed sensor associated with the target wheel with the output signal of the wheel speed sensor associated with the other wheels, or referring to the output signal of the wheel speed sensor associated with the target wheel. By comparing the amount of change per unit time in the rotation speed of the target wheel, which is learned by the controller, with a threshold value, it is determined whether or not the output signal of the wheel speed sensor associated with the target wheel is mixed with disturbance. ,
It outputs the value of the rotation speed of the wheel based on the output signal of the wheel speed sensor determined that there is no disturbance, or outputs the determination result of whether or not the output signal of the wheel speed sensor is mixed with disturbance. which outputs
A control device that determines whether or not a disturbance is mixed in the output signal of the wheel speed sensor only when the vehicle is stopped.

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