JP4414391B2 - Abnormality determination device for vehicle steering angle sensor - Google Patents

Description

  The present invention relates to a vehicle steering angle sensor abnormality determination device that determines a steering angle sensor abnormality using a detection value of a yaw rate sensor and a detection value of a lateral acceleration sensor.

Abnormality detection means for detecting abnormalities of sensors that detect the yaw rate, lateral acceleration, and steering angle, which are state quantities when the vehicle is turning, identifies gains that are parameters applied to related equations related to at least two sensors A technique for detecting an abnormality of each sensor by comparing the amount of change in each gain is known from Patent Document 1 below.
JP 2000-55933 A

  By the way, what was described in the said patent document 1 had the problem that the calculation load of an electronic control unit increased because complicated calculation was needed in order to identify a gain using a complicated relational expression.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to easily and reliably determine an abnormality of a steering angle sensor.

To achieve the above object, according to the first aspect of the present invention, a steering angle sensor that detects the steering angle of the vehicle, a yaw rate sensor that detects the yaw rate of the vehicle, and a lateral angle that detects the lateral acceleration of the vehicle. An acceleration sensor, a yaw rate sensor abnormality determination unit that determines abnormality of the yaw rate sensor based on at least a detection value of the yaw rate sensor, and a lateral that determines abnormality of the lateral acceleration sensor based on at least the detection value of the lateral acceleration sensor An acceleration sensor abnormality determination unit; a detection value conversion unit that converts one of the detection value of the steering angle sensor and the detection value of the yaw rate sensor so as to coincide with the other dimension; the yaw rate sensor abnormality determination unit; lateral acceleration sensor abnormality determination unit of the judgment result are both normal, and the vehicle is shown to condition that it is in the steady turning state When you are standing, compared with the other detection values of the transformed one of the detected value at the detection value conversion unit and the steering angle sensor and the yaw rate sensor, the steering angle sensor when they are in disagreement and a steering angle sensor abnormality determination unit determines abnormality, the vehicle is stable one condition indicating that in a turning state, the detection value and the detected value is the same turning direction of the lateral acceleration sensor of the yaw rate sensor And an abnormality determination device for a steering angle sensor of a vehicle, characterized in that both detected values exceed a predetermined value .

According to the invention described in claim 2, in addition to the first aspect, the pre-Symbol detection value and the steering angular velocity based on the detection value of the steering angle sensor of the yaw rate sensor indicates a different turning direction comprising determining counter steer state determination unit to counter steer state of the vehicle based on the vehicle is one shown to condition that it is in the steady turning state, the counter steer determination of the determination result counter steer state Therefore, there is proposed a steering angle sensor abnormality determination device characterized by not being.

According to a third aspect of the present invention, in addition to the configuration of the second aspect , the countersteer determination unit is configured such that a steering angular velocity obtained from a detection value of the steering angle sensor exceeds a predetermined value. An abnormality determination device for a steering angle sensor of a vehicle is proposed, in which the countersteer state is determined based on the above.
According to a fourth aspect of the present invention, in addition to the configuration of the first aspect, the steering angle sensor abnormality determining unit includes the one detected value converted by the detected value converting unit, the steering angle sensor, wherein comparing the other detected value of the yaw rate sensor, they malfunction determining device for a steering angle sensor for a vehicle, characterized by determining an abnormality when both mismatch right turn and left turn are proposed.

  The yaw rate estimation front wheel angle calculation unit M3 of the embodiment corresponds to the detection value conversion unit of the present invention, and the yaw rate estimation front wheel angle βyr and the lateral acceleration estimation front wheel angle calculated by the yaw rate estimation front wheel angle calculation unit M3 of the embodiment. The lateral acceleration estimated front wheel angle βg calculated by the calculation unit M4 corresponds to the detection value of the yaw rate sensor and the detection value of the lateral acceleration sensor of claim 2, respectively.

According to the first aspect, the lateral acceleration sensor for detecting a yaw rate sensor and the lateral acceleration detecting the yaw rate is both normal and when the vehicle is stable shown to condition that a turning state is satisfied In addition, based on the result of comparing and comparing the detected value of the steering angle sensor for detecting the steering angle and the detected value of the yaw rate sensor, an abnormality of the steering angle sensor is determined when they do not match. It is possible to reliably determine abnormality of the steering angle sensor with simple logic.

Furthermore, to indicate that there that the detection value of the yaw rate sensor and are detected value of the lateral acceleration sensor indicate the same turning direction, and both detected values are both exceeded the predetermined value in the turning state in which the vehicle is stabilized By setting one of the conditions, it is possible to reliably determine the stable turning state of the vehicle.

According to the configuration of claim 2 , when the steering angular velocity based on the detected value of the yaw rate sensor and the detected value of the steering angle sensor indicates different turning directions, the vehicle is in the countersteer state and not in the stable turning state. that it is not a countersteering state vehicle by one of stable indicates that a turning state to conditions, it is possible to reliably determine the stable turning state of the vehicle.

According to the configuration of the third aspect , since the counter steer state is determined based on the fact that the steering angular velocity obtained from the detected value of the steering angle sensor exceeds a predetermined value, it is possible to prevent erroneous determination of the counter steer state. it can.

According to the configuration of the fourth aspect , the steering angle sensor abnormality is determined when the comparison result between the detected value of the steering angle sensor and the detected value of the yaw rate sensor is inconsistent in both the right turn and the left turn. An abnormality of the angle sensor can be reliably determined.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples of the present invention shown in the accompanying drawings.

  1 to 5 show an embodiment of the present invention. FIG. 1 is a diagram showing the overall configuration of a vehicle steering angle sensor abnormality determination device. FIG. 2 is a diagram for explaining the operation of a turning determination unit. 3 is a diagram illustrating the operation of the counter steer determination unit, FIG. 4 is a diagram illustrating the operation of the determination permission unit, and FIG. 5 is a diagram illustrating the operation of the steering angle sensor abnormality determination unit.

  As shown in FIG. 1, an abnormality determination device that determines an abnormality of a steering angle sensor Sa that detects a steering angle δ of a steering wheel of a vehicle includes a yaw rate that detects a yaw rate γ of the vehicle in addition to the steering angle sensor Sa. A sensor Sb, a lateral acceleration sensor Sc that detects the lateral acceleration YG of the vehicle, and a wheel speed sensor Sd that detects the wheel speed Vw of each wheel are connected.

  The abnormality determination device includes a yaw rate sensor abnormality determination unit M1, a lateral acceleration sensor abnormality determination unit M2, a yaw rate estimation front wheel angle calculation unit M3, a lateral acceleration estimation front wheel angle calculation unit M4, a steering angular velocity calculation unit M5, and an actual front wheel. An angle calculation unit M6, a vehicle body speed calculation unit M7, a turning determination unit M8, a counter steer determination unit M9, a control state determination unit M10, a determination permission unit M11, and a steering angle sensor abnormality determination unit M12 are provided.

  The yaw rate sensor abnormality determination unit M1 determines abnormality of the yaw rate sensor Sb when the yaw rate γ detected by the yaw rate sensor Sb indicates an abnormal value that does not normally occur. Further, when the lateral acceleration YG detected by the lateral acceleration sensor Sc indicates an abnormal value that does not normally occur, the lateral acceleration sensor abnormality determining unit M2 determines the abnormality of the lateral acceleration sensor Sc.

  When the yaw rate sensor abnormality determining unit M1 determines abnormality of the yaw rate sensor Sb and the lateral acceleration sensor abnormality determining unit M2 determines abnormality of the lateral acceleration sensor Sc, sensors other than the yaw rate sensor Sb and the lateral acceleration sensor Sc, for example, wheel speed The detection value of the sensor Sd can be referred to. That is, if the detected value of the wheel speed sensor Sd indicates that the vehicle is stopped, but the yaw rate γ or the lateral acceleration YG greater than a predetermined value is detected, the yaw rate sensor Sb or the lateral acceleration sensor Sc is abnormal. It can be determined that

  The vehicle body speed calculation unit M7 to which the wheel speed Vw detected by the wheel speed sensor Sd is input calculates, for example, the vehicle body speed V as an average value of the wheel speeds Vw of four wheels. The yaw rate estimation front wheel angle calculation unit M3 calculates the yaw rate estimation front wheel angle βyr from the yaw rate γ detected by the yaw rate sensor Sb, the vehicle body speed V calculated by the vehicle body speed calculation unit M7, and the vehicle specifications. The dimension of the yaw rate γ is angular velocity, but the dimension of the yaw rate estimation front wheel angle βyr is an angle. Therefore, the yaw rate estimation front wheel angle calculation unit M3 constitutes the detection value conversion unit of the present invention. The lateral acceleration estimated front wheel angle calculation unit M4 calculates the lateral acceleration estimated front wheel angle βg from the lateral acceleration YG detected by the lateral acceleration sensor Sc, the vehicle body speed V calculated by the vehicle body speed calculation unit M7, and vehicle specifications. The dimension of the lateral acceleration estimated front wheel angle βg is also an angle.

  As is apparent from FIG. 2 which shows a part of FIG. 1, the yaw rate estimation front wheel angle βyr estimated by the yaw rate estimation front wheel angle calculation unit M3 and the lateral acceleration estimation front wheel angle βg estimated by the lateral acceleration estimation front wheel angle calculation unit M4. The turning determination unit M8 to which is input determines whether the vehicle is in a turning state based on whether the yaw rate estimated front wheel angle βyr and the lateral acceleration estimated front wheel angle βg indicate the same turning direction.

In particular,
Yaw rate estimated front wheel angle βyr> 1 ° and lateral acceleration estimated front wheel angle βg> 1 °
When is established, it is determined that the vehicle is turning right,
Yaw rate estimated front wheel angle βyr <-1 ° and lateral acceleration estimated front wheel angle βg <-1 °
When is established, it is determined that the vehicle is in a left turn state.

  Returning to FIG. 1, the steering angular velocity calculation unit M5 to which the steering angle δ detected by the steering angle sensor Sa is input calculates the steering angular velocity δ ′ by differentiating the steering angle δ with respect to time. The actual front wheel angle calculation unit M6 to which the steering angle δ is input calculates an actual front wheel angle β that is proportional to the steering angle δ.

As is apparent from FIG. 3 which is a part of FIG. 1, the counter steer determination unit M9 to which the yaw rate γ detected by the yaw rate sensor Sb and the steering angular velocity δ ′ calculated by the steering angular velocity calculation unit M5 are input.
Condition 1: The direction of the yaw rate γ and the direction of the steering angular velocity δ ′ are reversed. Condition 2: The steering angular velocity δ ′> 30 ° / sec.
When both of the above are established simultaneously, that is, when the steering wheel is operated in the direction opposite to the yaw rate direction and the steering angular speed δ ′ for operating the steering wheel is equal to or higher than a predetermined value, it is determined that the vehicle is in the counter steer state. To do. When the counter steer state is determined, the counter steer timer is set to 500 msec, and when the counter steer state is not determined, the counter steer timer is counted down.

As is apparent from FIG. 4 which shows a part of FIG. 1, the yaw rate sensor abnormality determination unit M1, the lateral acceleration sensor abnormality determination unit M2, the turning determination unit M8, the counter steer determination unit M9, the control state determination unit M10, and the yaw rate estimation The determination permission unit M11 connected to the front wheel angle calculation unit M3, the lateral acceleration estimation front wheel angle estimation unit M4, and the vehicle body speed calculation unit M7 has normal determination results of the yaw rate sensor abnormality determination unit M1 and the lateral acceleration sensor abnormality determination unit M2. When the following conditions 1 to 5 are satisfied, the abnormality determination of the steering angle sensor Sa is permitted.
Condition 1: Vehicle speed V> 10.8 km / h
Condition 2: The turning determination unit M8 determines that the vehicle is in a turning condition. Condition 3: The count value of the counter steer timer is 0 msec and the vehicle is not in the counter steer condition. Condition 4: ABS (anti-lock) Brake system), TCS (traction control system) and EDC (engine drag control) are all inoperative. Condition 5: | Yaw rate estimated front wheel angle βyr−lateral acceleration estimated front wheel angle βg | <0.2 °
That is, the vehicle is turning at a vehicle body speed V equal to or higher than a predetermined value, is not in a counter steer state, ABS, TCS, and EDC are all inactive, and yaw rate estimated front wheel angle βyr and lateral acceleration estimated front wheel angle βg When the deviation of the steering angle sensor Sa is less than the predetermined value, the abnormality determination of the steering angle sensor Sa is permitted assuming that the vehicle is in a stable turning state.

As is clear from FIG. 5 that shows a part of FIG. 1, the steering angle sensor abnormality determination unit M12 sets the gain value G to G = (actual front wheel angle β ÷ yaw rate) when the determination permission unit M11 permits. Estimated front wheel angle βyr) x 100%
If G <20%, the abnormality determination timer is counted up, and if G> 80%, the abnormality determination timer is counted down. For both abnormality determination timers for the right turn direction and the left turn direction, if the count value exceeds 300 msec, it is determined that an abnormality may have occurred in the steering angle sensor Sa, and the detection of the steering angle sensor Sa is performed. By halving the control gain of the control device using the value, the influence of the abnormality of the steering angle sensor Sa is minimized. On the other hand, if the count value exceeds 1500 msec, an abnormality of the steering angle sensor Sa is confirmed, the operation of the control device is prohibited, and a predetermined fail-safe process such as turning on a warning lamp is executed.

  As described above, when the vehicle is in a stable turning state, the yaw rate estimated front wheel angle βyr obtained by converting the yaw rate γ detected by the yaw rate sensor Sb and the actual front wheel corresponding to the steering angle δ detected by the steering angle sensor Sa. Compares the angle β with each other and determines whether the steering angle sensor Sa is abnormal when they do not match. Therefore, it is possible to determine the abnormality of the steering angle sensor Sa with simple logic without using complicated and time-consuming relational expressions. can do.

  Although the embodiments of the present invention have been described above, various design changes can be made without departing from the scope of the present invention.

  For example, in the embodiment, the dimension (angular velocity) of the yaw rate γ is converted to the yaw rate estimated front wheel angle βyr in accordance with the dimension (angle) of the actual front wheel angle β, but conversely, the dimension (angle) of the steering angle δ is You may convert so that it may match with the dimension (angular velocity) of yaw rate (gamma).

The figure which shows the whole structure of the abnormality determination apparatus of the steering angle sensor of a vehicle The figure explaining the effect | action of a turning determination part The figure explaining the effect | action of a counter steer determination part The figure explaining the effect | action of a determination permission part The figure explaining the effect | action of a steering angle sensor abnormality determination part

M1 Yaw rate sensor abnormality determination unit M2 Lateral acceleration sensor abnormality determination unit M3 Yaw rate estimation front wheel angle calculation unit (detection value conversion unit)
M9 Counter steer determination unit M12 Steering angle sensor abnormality determination unit Sa Steering angle sensor Sb Yaw rate sensor Sc Lateral acceleration sensor βg Lateral acceleration estimated front wheel angle (detected value)
βry Yaw rate estimated front wheel angle (detected value)
δ Steering angle δ ′ Steering angular velocity γ Yaw rate (detected value)
YG Lateral acceleration (detected value)

Claims (4)

A steering angle sensor (Sa) for detecting a steering angle (δ) of the vehicle;
A yaw rate sensor (Sb) for detecting the yaw rate (γ) of the vehicle;
A lateral acceleration sensor (Sc) for detecting a lateral acceleration (YG) of the vehicle;
A yaw rate sensor abnormality determination unit (M1) that determines abnormality of the yaw rate sensor (Sb) based on at least a detection value of the yaw rate sensor (Sb);
A lateral acceleration sensor abnormality determining unit (M2) that determines abnormality of the lateral acceleration sensor (Sc) based on at least a detection value of the lateral acceleration sensor (Sc);
A detection value conversion unit (M3) that converts one dimension of the detection value of the steering angle sensor (Sa) and the detection value of the yaw rate sensor (Sb) so as to coincide with the other dimension;
The yaw rate sensor abnormality determining unit (M1) and the lateral acceleration sensor abnormality determination unit determining result of (M2) are both normal, and when the vehicle is shown to condition that it is in a stable turning state is satisfied In addition, one detection value converted by the detection value conversion unit (M3) is compared with the other detection value of the steering angle sensor (Sa) and the yaw rate sensor (Sb). steering angle sensor abnormality determination unit determining abnormality of the steering angle sensor (Sa) and a (M12),
One of the conditions indicating that the vehicle is in a stable turning state is that the detection values (γ, βyr) of the yaw rate sensor (Sb) and the detection values (YG, βg) of the lateral acceleration sensor (Sc) are the same. It indicates the turning direction, and abnormality determination device of the steering angle sensor of the vehicle, characterized in der Rukoto that both detection values are both exceeded the predetermined value. Counter steer for determining the counter steer state of the vehicle based on the steering angular velocity (δ ′) based on the detected value of the yaw rate sensor (Sb) and the detected value of the steering angle sensor (Sa) indicating different turning directions. A determination unit (M9),
The vehicle is the one shown to condition that it is in the steady turning state, wherein said counter judgment result of the steering judging portion (M9) is not a counter steer state, according to claim 1 An abnormality determination device for a steering angle sensor of a vehicle. The counter steer determination unit (M9) determines the counter steer state based on a steering angular velocity (δ ′) obtained from a detection value of the steering angle sensor (Sa) exceeding a predetermined value. The abnormality determination device for a steering angle sensor for a vehicle according to claim 2 . The steering angle sensor abnormality determination unit (M12), the and the other of the detected value of the said the transformed one of the detected value at the detection value conversion unit (M3) steering angle sensor (Sa) and the yaw rate sensor (Sb) comparison, characterized in that they determine the abnormality when both mismatch right turn and left turn, the abnormality determination apparatus for a steering angle sensor for a vehicle according to claim 1.

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