JP2002200952A - Steering system failure diagnosing device of automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steering system failure diagnosing device of an automobile for reducing the occurrence rate of a secondary accident, and improving safety of traffic and an occupant by properly coping with a diagnosis by diagnosing that inconvenience is caused in a steering device of a vehicle damaged by a collision. SOLUTION: This steering system failure diagnosing device is provided with a detecting means mounted on the automobile, and detecting the collision applied to the vehicle, a first control means for outputting a control signal according to the size of the collision applied to the vehicle, and a second control means for starting a prestored control program according to the size of the collision on the basis of the control signal outputted by the first control means. The second control means controls a power plant system control unit so that amplitude by vibration of the steering device becomes a preset value or less in the collision such as an air bag does not unfold according to the control program, makes a travel limiting request for reducing a vehicle speed, executes and processes a failure diagnosis of the steering device in the collision such as the air bag unfolds, and makes a travel limiting request for limiting the vehicle speed on the basis of the diagnostic result.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for diagnosing a failure of a steering system of an automobile for safety of traffic and occupants. It relates to a security system for dealing with.

[0002]

When a car accident occurs while driving a car, the user tends to judge the degree of damage to the vehicle only by appearance. for that reason,
Regardless of the true damage condition of the vehicle, when it is determined that the vehicle can be driven, the vehicle often runs by itself and drives to a maintenance shop or home. However, a vehicle whose steering system has been damaged by an accident, even if it is capable of self-driving, inherently has the danger of a secondary accident occurring, and may cause a road failure during traveling. In many cases, it interferes with other traffic.

Usually, a steering system control unit of a vehicle, for example, a power steering ECU is provided with a self-diagnosis (self-diagnosis function) and a fail-safe function as a backup function at the time of failure. However, this self-diagnosis is to notify the user of an abnormal location by using a warning light (steering warning lamp), and the fail-safe function is to control the failure at the time of failure depending on the content of the failure of the sensor system and the solenoid system. It switches the sensor system or turns off the solenoid, but does not positively detect the damage state of the steering device in the event of a collision accident. In addition, since such a backup function cannot give an advance warning of a damage state that gradually deteriorates with time, the user can determine whether or not the vehicle can travel immediately after a vehicle collision. Without having to worry about unnecessary and uneasy thoughts. And
Since it is not possible to determine whether or not the vehicle is allowed to travel, there is a problem that a dangerous situation cannot be detected, and the vehicle continues to travel with the steering device damaged.

Accordingly, the present invention has been made to solve the above-mentioned problem of the self-diagnosis function in the conventional steering control system of an automobile, and it is intended to surely prevent the impact received on the vehicle. To reduce the incidence of secondary accidents and improve traffic and occupant safety by diagnosing malfunctions in steering systems of vehicles damaged by collisions and taking appropriate measures. It is an object of the present invention to provide an apparatus for diagnosing a steering system failure of an automobile that can perform the operation.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a detecting means for detecting a collision applied to a vehicle mounted on an automobile, and a vehicle based on information data detected by the detecting means. Control means for outputting a control signal corresponding to the magnitude of the collision applied to the vehicle, and control stored and stored in advance according to the magnitude of the collision based on the control signal output from the first control means. Second control means for activating a program, wherein the second control means adjusts the vibration amplitude of the steering device to a set value according to the control program in the event of a collision in which the airbag does not deploy. As described below, a travel restriction request for controlling the power plant system control unit to reduce the vehicle speed is made, and in the case of a collision where the airbag is deployed, the steering device is controlled. Processing the fault diagnosis execution, characterized in that the travel limiting request is made to limit the vehicle speed based on the diagnosis result.

[0006] The first control means detects the magnitude of the collision based on the output value of one of an airbag module sensor, an acceleration sensor and an inclination sensor.

The second control means detects occurrence of a malfunction of the steering device based on any output value of a steering angle, a steering torque, and a power steering drive motor current of the steering device. I do.

The second control means performs a harness check of a steering drive system when executing a failure diagnosis of the steering device in the event of a collision in which the airbag is deployed. I do.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a steering system failure diagnosis apparatus according to the present invention will be described below with reference to FIG. Figure 1
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram for explaining a vehicle steering system failure diagnosis device of the present invention.

As shown in FIG. 1, a steering system failure diagnosis apparatus 10 of the present invention includes various sensors 11, an airbag control unit (airbag ECU) 12, a bus 13, a steering system control unit (steering system ECU) 14, It mainly includes a steering device 15, an engine control unit (engine ECU) 16, a transmission control unit (transmission ECU) 17, and the like.

Various sensors 11 include a front sub-sensor 1
8, a side airbag sensor 19, an acceleration sensor 20, an inclination sensor 21, and the like. Output values of these various sensors 11 are input to the airbag ECU 12.

The airbag ECU 12 includes a front sub-sensor 18 disposed in front of the vehicle body and an airbag ECU 12.
Central control unit (CP)
U) has exceeded the set value, and the airbag ECU
Only when the safing sensor in 12 is turned on, it is determined that the impact due to the collision from the front of the vehicle is large, the front airbag 22 is operated, and a large collision signal is output to the steering system ECU 14. I do. Further, the airbag ECU 12 determines that the deceleration signal of the side collision G sensor in the side airbag sensor 19 disposed on the side of the vehicle body has exceeded a set value, and determines whether the safing in the side airbag sensor 19 has occurred. Only when the sensor is turned on, it is determined that the impact at the time of the side collision is large, the side airbag 23 on the side of the collision is operated, and a large collision signal is output to the steering system ECU 14.

The airbag ECU 12 includes an acceleration sensor (a longitudinal acceleration sensor, a lateral acceleration sensor, etc.).
Based on the acceleration signal of 20, the magnitude of the impact applied to the vehicle body from the front and side is determined. Then, when it is determined that the acceleration signal of the acceleration sensor 20 at the time of a collision from the side of the vehicle body receives an impact of a predetermined value or more, a large collision signal having a large impact is output to the steering system ECU 14. Further, when it is determined that a light impact that does not accompany the operation of each airbag is received, a small collision signal having a small impact is output to the steering system ECU 14.

Further, the airbag ECU 12
Is configured to determine the tilt state of the vehicle body based on the output value from the tilt sensor 21. When it is determined that the lean state of the vehicle body is large, a large collision signal is output to the steering system ECU.
And outputs information data of an output value from the inclination sensor 21 to the steering system ECU 14.

A steering ECU 14 networked with the airbag ECU 12 via a bus 13 that can communicate with each other, such as a CAN (controller area network) data bus, is, for example, an electric power steering control unit. The CPU in the steering ECU 14 executes the post-collision failure diagnosis program in accordance with the respective collision signals from the ECU, thereby performing post-collision failure diagnosis 1 and 2 described later.
When the crash failure diagnosis 1 or 2 is started, the damage state of the steering device 15 is positively identified in accordance with the program. The diagnosis result is provided to the occupant, and the optimum fail-safe and the regulation or restriction of the running function are executed through the engine ECU 16 and the transmission ECU 17 according to the damage state.

The steering system ECU 14 includes a steering wheel shaft 2 as an input shaft side of the steering device 15.
The output values of a steering angle sensor 25 attached to the gearbox 4 and a steering torque sensor 27 attached to the gearbox 26 as an output shaft are input, respectively. An output signal is input. Then, a motor current for driving the motor according to the vehicle speed, the engine speed, and the like is transmitted to the steering system E.
It is generated by a drive circuit 30 in the CU 14 and is supplied to a power steering drive motor (power steering motor) 31 attached to the gear box 26 side. Further, a drive circuit 3 is provided in the steering system ECU 14.
Detection circuit 3 for detecting an abnormality of the motor current generated at 0
2 is provided, and when the detection circuit 32 detects an abnormal current, a warning lamp 33 disposed on the meter panel is turned on. Further, a filter 34 for removing a specific frequency band of an output value from the steering torque sensor 27, for example, a frequency of several tens Hz or more may be provided in the steering system ECU 14. By the way, the steering system ECU 14 includes:
Even if a failure occurs in an electric signal system such as an ECU system, a vehicle speed signal system, and an engine speed signal system, a fail-safe function that ensures minimum steering characteristics is incorporated.

The steering system ECU 14 exchanges instructions, control information, information data, etc. with each other with control units such as an engine ECU 16 for performing fuel injection control and a transmission ECU 17 for performing power transmission system control via the bus 13. Will be The steering system ECU 14
The bus 13 is also networked with various vehicle electronic control units such as a suspension control unit and a body control unit.

Next, the steering system failure diagnosis control executed by the steering system ECU 14 will be described with reference to FIGS. FIG. 2 is a flowchart for explaining an example of an operation process of the steering system failure diagnosis control performed by the steering system ECU 14 of the present invention. FIG. 3 is a diagram for explaining an operation of a collision determination process performed by the airbag ECU 12. FIG. 4 is a flowchart for explaining the operation of the post-collision failure diagnosis 1, FIG. 5 is a flowchart for explaining the operation of the post-collision failure diagnosis 2, and FIG. 5 is a flowchart for explaining the operation of FIG.

When the ignition is turned on, the steering ECU 1
When power is supplied to 4, the steering system failure diagnosis control (failure diagnosis program after collision) is started. First, as shown in FIG.
In step 100, it is determined whether or not the post-collision failure diagnosis execution request flag is set in the steering system ECU 14. If it is determined that the flag has not been set, the process proceeds to step 101, while if it is determined that the flag has been set, the processes of step 105 and subsequent steps are executed.

At the same time as the start of the steering system failure diagnosis control by the steering system ECU 14, the airbag ECU 12
As shown in (2), in step 200, a collision determination process is started. In step 201, it is determined whether or not the airbag operation deceleration is detected. If the vehicle has collided and the front or side airbag operation collision deceleration is detected, the process proceeds to step 202 and the steering system ECU
14 to output a large collision signal. On the other hand, in the case of non-detection, the process proceeds to step 203, and it is determined whether or not the acceleration sensor 20 detects an acceleration equal to or higher than a predetermined value. If it is determined based on the acceleration signal of the acceleration sensor 20 that an impact of a predetermined value or more has been received, step 20 is performed.
The process then proceeds to 2 to output a large collision signal to the steering system ECU 14. On the other hand, if no detection is made in step 203,
The routine proceeds to step 204, where it is determined whether or not a slight impact that does not involve the operation of each of the airbags 22 and 23 is received. Here, when it is determined that a slight impact has been received, the routine proceeds to step 205, where the small collision signal is sent to the steering system ECU1.
4 is output. If no detection is made in step 204, the process proceeds to step 206, where the tilt sensor 21
It is determined whether or not has detected an inclination angle equal to or greater than the set value. If detected, the process proceeds to step 202 and outputs a large collision signal to the steering system ECU 14. On the other hand, if no detection is made in step 206, the process returns to step 200.

Next, the steering system ECU 14 executes step 1
At 01, it is determined whether or not a collision signal has been output from the airbag ECU 12. And airbag EC
If a collision signal is output from U12, step 10
On the other hand, if the process has not been output in step 101, the process returns to repeat the execution process of step 101. In step 102, it is determined whether or not the collision signal is a large collision signal.
When the large collision signal is output from U12, the process proceeds to step 103. On the other hand, if the small collision signal has been output, the process proceeds to step 300 and the post-collision failure diagnosis 1
Is executed.

Here, the operation process of the post-collision failure diagnosis 1 will be described. As shown in FIG. 4, when the operation process of the post-collision failure diagnosis 1 is started in step 300, the process proceeds to step 301, and reading of the output signal from the steering torque sensor 27 is started. This output signal is subjected to filter processing in hardware by the filter 34 in the steering system ECU 14 in step 302 to remove electrical signal vibration such as noise and to extract only vibration due to mechanical causes. Thereafter, in step 303, a high-pass filter processing of, for example, about 1 or 2 Hz is performed in a software manner, so that the steering vibration due to the driver's intention is removed, and only the vibration caused by the mechanical cause of the steering device 17 is extracted. Then, it is determined in step 304 whether or not the frequency of the output signal extracted by the filter processing is equal to or greater than the set value and whether the vibration amplitude is equal to or greater than the set value. If this determination is true, the routine proceeds to step 305, where a travel restriction request is made to reduce the vehicle speed by controlling the engine control unit 16 and the transmission control unit 17 so that the vibration amplitude and the like become equal to or less than the set values. You. On the other hand, if the determination in step 304 does not apply, the process returns to step 300.

As described above, the post-collision failure diagnosis 1 when the small collision signal is input to the steering system ECU 14 is executed. The post-collision failure diagnosis 1 is continuously and repeatedly executed, so that even if the steering device 15 is slightly damaged, the steering ECU 1
4, the damaged state is continuously detected and judged. The post-collision failure diagnosis 1 is executed not only as a special failure diagnosis function after a collision but also as a fail-safe logic of a normal steering system in the steering ECU 14 so as to be periodically executed. It may be. As a result, fluctuations (vibration) in the steering torque caused by backlash of the steering system, misalignment, damage to the tire / wheel system, etc. are detected, and when the vibration amplitude or the like exceeds a set value, Since the power plant ECU is required to limit the driving so as not to exceed the set value, secondary accidents in the steering system due to collisions are prevented while leaving maximum room for the user to operate after a collision. Is done.

Next, at step 102, the large collision signal output from the airbag ECU 12 is transmitted to the steering system ECU1.
4 and the process proceeds to step 103. In step 103, a running cutoff process (running limit level 0) for setting the vehicle speed to 0 (km / h) is performed. When step 103 is executed, the process proceeds to step 104, where a flag indicating that the large collision signal has been input to the steering system ECU 14 is set. As a result, even if the active diagnosis described later cannot be completed normally for some reason after the major collision, the active diagnosis is surely executed at the next ignition ON. Then, when the routine proceeds to step 105, it is determined whether or not the vehicle speed has become zero. Here, if it is determined that the vehicle speed has become 0, the process proceeds to step 400. If not, the process returns to repeat step 105.

In step 400, post-collision failure diagnosis 2 is executed. The post-collision failure diagnosis 2 will be described. As shown in FIG. 5, first, in step 401, it is determined whether or not a large collision signal has been output from the inclination sensor 21. This is for estimating whether or not the active diagnosis described later is in a state where it can be performed.
Based on the output signal from the inclination sensor 21, if the inclination state of the vehicle body is large, it is determined that the vehicle is out of wheel or rollover, and the execution of the active diagnosis is prevented. If this is the case, the routine proceeds to step 402, where the diagnosis result of the post-collision failure diagnosis 2 is set to be undiagnosable. Step 4
If the determination in step S01 is negative, the process proceeds to step 403 to start checking the steering drive system harness such as the drive circuit 30 and the power steering motor 31. This means
Before performing an active diagnosis, which will be described later, the driving circuit voltage and the motor terminal voltage due to the extremely short-time driving of the power steering motor 31 are monitored, and a logic mismatch between the monitor and the driving logic is confirmed. This is to confirm that there is no abnormality. Therefore, step 40
If it is determined in step 4 that the drive system harness is abnormal, it means that the active diagnosis after the collision cannot be performed accurately. Is determined.

When it is determined in step 404 that there is no abnormality in the steering drive system harness, the process proceeds to step 406 to start reading the output value from the steering angle sensor 25, and in the next step 407, Motor constant voltage driving is started for a fixed time (short time) in the direction of the middle point of the steering angle or in a certain fixed direction. Then step 40
8 and the active diagnosis is started.

In the next step 409, the steering angle sensor 2
5, the steering angular angular velocity calculated by differentiating the output value from
It is determined whether or not the value is larger than a preset value A1. This is to determine whether or not the front wheel tires are on the road surface.When the power steering motor 31 is driven at a constant voltage in a state where the tires are not on the ground, when compared with the case of normal grounding, , Power steering motor 31
This is because the load is very light, the rotation speed is high, and the load current is small. Here, if it is determined that the steering angular velocity is larger than the set value A1 and the tire is not in contact with the ground, it is impossible to execute the active diagnosis, and the routine proceeds to step 402, where the diagnosis of the post-collision failure diagnosis 2 Make the result non-diagnosable.

In the next step 410, it is determined whether or not the calculated steering angular velocity is smaller than a preset value A2. This is to detect a state in which the steering cannot be turned off due to a failure of the steering device 15 or an obstacle around the front wheel tires, and the load on the power steering motor 31 is large compared to a state in which the steering is normally turned off. This is because the rotation speed decreases and the load current increases. Here, if it is determined that the steering angular angular velocity is larger than the set value A2 and the steering is turned off, step 41 is executed.
Move to 1. On the other hand, when it is determined that the steering angular velocity is smaller than the set value A2 and the steering cannot be turned, the process proceeds to step 419.

Step 411 and subsequent steps will be described.
First, in step 411, automatic steering to the steering angle midpoint is performed based on the output value of the steering angle sensor 25. Then, in the next step 412, it is determined whether or not the steering angular velocity at this time is smaller than the set value A2. In this case, it is determined that the active diagnosis execution frequency NA is a predetermined number N (NA = N) and the maximum steering angle α is smaller than a preset value α2 (α <α2), and the process proceeds to step 419. If not, the process proceeds to step 413. In step 413, automatic steering is performed at a constant voltage up to a preset maximum angle in one side direction. Then, it is determined in the next step 414 whether or not the steering angular velocity at this time is smaller than the set value A2. If this determination is applicable, the respective steering angles α at that time are stored, and step 415 is executed.
The process proceeds to step 419 as a result of the smaller value of the steering angle as a result of the test on the other side, and to step 415 if not. In step 415, automatic steering is performed at a constant voltage up to a preset maximum angle in the other direction. Then, it is determined at next step 416 whether or not the steering angular velocity at this time is equal to or less than the set value A2.
Made in. If this is the case, step 41
Move to 9. If not applicable, step 41
7, the steering is automatically steered to the steering angle midpoint based on the output value of the steering angle sensor 25. Thereafter, the process proceeds to step 418, and the result of the active diagnosis is diagnosed as small damage.

Next, step 419 and subsequent steps will be described. In step 419, the current steering angle is stored in the nonvolatile memory. Thereafter, the process proceeds to step 420, where it is determined whether or not the active diagnosis execution number NA has been performed a predetermined number N times (for example, three times) or more. Here, if it is determined that it is not applicable, the process proceeds to step 421, where the number of active diagnoses NA is set to NA + 1, and the process returns to step 402. On the other hand, if it is determined in step 420 that this is the case, the process proceeds to step 422.

In step 422, the maximum steering angle in the past N active diagnosis runs is determined. afterwards,
In step 423, it is determined whether or not the maximum turning angle is larger than a preset value α1. If this is the case, the process proceeds to step 424, where the active diagnosis result is diagnosed as small damage. If the answer is NO in step 423, the process proceeds to step 425, in which it is determined whether the maximum turning angle is larger than a preset value α2 and equal to or less than a preset value α1. If this is the case, the process proceeds to step 426, where the active diagnosis result is diagnosed as being damaged. On the other hand, if it does not correspond in step 425, the process proceeds to step 427, and the active diagnosis result is diagnosed as large damage.

Then, the steering system ECU 14 performs the processing after step 106 based on the determination result of the active diagnosis. In other words, if the diagnosis result of the active diagnosis is large (step 106), the running restriction level 0 for interrupting the running is executed (step 10).
7) Then, the steering device 15 is shifted to the fail-safe state (step 108). Then, when the post-collision failure diagnosis 2 is completed normally, the flag set in the steering system ECU 14 in step 104 is reset (step 109).

If the diagnosis result of the active diagnosis is that the vehicle is damaged (step 110), the traveling limit level 1 for controlling the power plant ECU to limit the maximum speed of the vehicle to a low speed (for example, 30 km / h). Is executed (step 111), and then the steering device 15
A transition is made to the fail-safe state (step 108).
Then, after the failure diagnosis 2 is completed normally after the collision,
The flag set in the steering system ECU 14 in step 104 is reset (step 109).

Further, if the diagnosis result of the active diagnosis is a small damage (step 112), a travel limit level for controlling the power plant ECU to limit the maximum speed of the vehicle to a medium speed (for example, 60 km / h). 2 is executed (step 113), and then the steering device 15
Is shifted to the fail-safe state (step 10
8). Then, since the post-collision failure diagnosis 2 is normally completed, the flag set in the steering system ECU 14 in step 104 is reset (step 10).
9).

Further, if the diagnosis result of the post-collision failure diagnosis 2 and the active diagnosis cannot be diagnosed, the running restriction level 0 for stopping the running is executed (step 11).
4) Then, the steering device 15 is shifted to a fail-safe state (step 115).

The operation process of the post-collision failure diagnosis control is continuously and repeatedly executed.
The broken state in the steering system is sequentially grasped, and traveling control is performed according to the progress of the broken state.

In the above active diagnosis, the diagnosis result is obtained based on the output of the steering angle sensor 25. However, the present invention is not limited to this.
The diagnosis result may be obtained based on the motor current for driving the motor generated by the drive circuit 30 in U14.

Mainly, a driving circuit 30 in the steering system ECU 14
The case where the active diagnosis is performed based on the motor current generated by the above will be described. Instead of the configuration of steps 409 to 416 in the active diagnosis shown in FIG. 5, the configuration of steps 500 to 507 is adopted. That is, as shown in FIG. 6, in step 500, it is determined whether or not the motor current is smaller than a preset value C1. This is to determine whether or not the front tire is on the road surface. When the power steering motor 31 is driven at a constant voltage while the tire is not on the ground (step 407), the normal tire This is because the load on the power steering motor 31 is very light, the number of rotations is high, and the motor current is small.
Here, when it is determined that the motor current is smaller than the set value C1 and the tire is not in contact with the ground, the active diagnosis cannot be executed. Is not diagnosed.

In the next step 501, the motor current is
It is determined whether or not the value is larger than a preset value C2. This is to detect a state in which the steering cannot be turned off due to a failure of the steering device 15 or an obstacle around the front wheel tires, and the load on the power steering motor 31 is large compared to a state in which the steering is normally turned off. This is because the rotation speed decreases and the motor current increases. Here, when it is determined that the motor current is larger than the set value C2 and the steering cannot be turned, the process proceeds to step 419. On the other hand, when the motor current is equal to or less than the set value C2, the steering is turned. If it is determined that it is in the state, the process proceeds to step 502.

In step 502, the vehicle is automatically steered to the steering angle midpoint based on the output value of the steering angle sensor 25. Then, it is determined in the next step 503 whether or not the motor current detected by the detection circuit 32 is larger than the set value C2. In this case, if the number of active diagnosis executions NA is a predetermined number N (NA =
N), the maximum steered angle α is smaller than the preset set value α2 (α <α2), and the process proceeds to step 419; otherwise, the process proceeds to step 504. Step 50
In No. 4, automatic steering is performed at a constant voltage up to a preset maximum angle in one side direction. Then, it is determined in the next step 505 whether or not the motor current at this time is larger than the set value C2. If it corresponds to this determination, the flow shifts to step 419; otherwise, to step 506.
Move to In step 506, automatic steering is performed at a constant voltage up to a preset maximum angle in the other side direction. Then, it is determined in the next step 507 whether or not the motor current detected at this time is larger than the set value C2. In the case of this judgment, each steering angle α at that time
Is stored, and the process proceeds to step 417. As a result, the smaller value of the steering angle obtained as a result of the test on the other side and the steering angle
Move to 9. If not applicable, step 41
7, the steering is automatically steered to the steering angle midpoint based on the output value of the steering angle sensor 25. Thereafter, the process proceeds to step 418, and the result of the active diagnosis is diagnosed as small damage.

As described above, the operation process of the post-collision failure diagnosis 2 when the large collision signal is input to the steering system ECU 14 is executed. The operation process of the post-collision failure diagnosis 2 is continuously and repeatedly executed,
The state of damage is sequentially grasped, and travel control is performed according to the degree of damage.

According to the steering system failure diagnosis apparatus 10 of the present invention having such a configuration, the front and side airbags 22,
It is possible to reliably detect an impact force acting on the vehicle 23, an impact force applied from the front or side, or an abnormal inclination of the vehicle. At that time, based on the detection values detected by the various sensors 11, the airbag ECU 12 performs a failure diagnosis 1 at the time of a small collision or the like, or a failure diagnosis 2 at the time of a large collision such as an airbag operation. , Steering system ECU 14
It is set to be started by. By doing so,
When the crash failure diagnosis 1 as a self-diagnosis program executed after a small collision is started, even if there is no problem after the collision, fluctuations in the steering torque at the time of traveling due to the backlash of the steering device 15 and the misalignment are caused. As a result, the power plant ECU requests travel limitation to the vehicle speed up to the vehicle speed at which no abnormality occurs, and the state of damage to the steering system is continuously detected and determined. As a result, the damage situation can be continuously grasped, and the secondary accident of the steering device 15 due to the collision can be reliably prevented while leaving the driving room of the user after the collision to the maximum.

When the post-collision failure diagnosis 2, which is performed after a large collision, is started, the collision is detected and the vehicle is stopped. Then, the operation check of the steering system harness is performed, and the steering device 15 is operated independently. Perform active diagnostics.
This is because the collision between the tire and the body occurs due to damage to the steering system and the body around the steering device 15 due to the collision,
The steering angle range can be limited, and such mechanical damage cannot be detected by electrical diagnostics. Therefore, the steering device 15 is actually steered to determine damage, and the active device of the post-collision failure diagnosis 2 automatically steers the steering device 15 and turns the steering device 15 to the maximum steering angle. This is to diagnose the degree of damage to the steering device 15 based on the steering angle, motor current, and the like at that time. Based on the results of this diagnosis, optimal control of the vehicle control system, such as limiting the maximum speed through engine output control and transmission shift control, is carried out, so that optimal limp home control according to the damage state of the vehicle is achieved. This can be implemented, and the level of vehicle travel control after a collision can be increased, so that user convenience and safety can be improved.

Further, by executing the post-collision failure diagnosis 1 periodically during normal use of the vehicle,
Even in the case of steering backlash or damage that cannot be generally recognized as an accident, the post-collision failure diagnosis 1 grasps and recognizes the current situation and recognizes the user in advance before the fail-safe function is activated and a warning is issued. And enhances user safety and protection.

[0045]

As described above, according to the vehicle steering system failure diagnosis apparatus of the present invention, it is possible to reliably detect a collision received by a vehicle and diagnose the occurrence of a failure in the vehicle steering system. The provision of the steering system control means in which the post-collision failure diagnosis program for appropriately coping with the collision state is provided, the failure of the steering system after the collision can be positively detected. Furthermore, by performing the optimal control of each vehicle control system system based on the failure diagnosis result, it is possible to reduce the incidence of secondary accidents after a collision, thereby improving the safety of traffic and occupants. Can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a configuration of a steering system failure diagnosis apparatus for an automobile according to the present invention.

FIG. 2 is a flowchart for explaining an example of an operation process of steering system failure diagnosis control performed in the steering system ECU of the present invention.

FIG. 3 is a flowchart illustrating an operation of a collision determination process performed in the airbag ECU.

FIG. 4 is a flowchart for explaining the operation of the post-collision failure diagnosis 1 of the present invention.

FIG. 5 is a flowchart for explaining the operation of the post-collision failure diagnosis 2 of the present invention.

FIG. 6 is a flowchart for explaining the operation of another post-collision failure diagnosis 2 of the present invention.

[Explanation of symbols]

Reference Signs List 10 steering system failure diagnosis device 11 various sensors 12 airbag control unit (airbag ECU) 13 bus 14 steering system control unit (steering system ECU) 15 steering device 16 engine control unit 17 transmission control unit 18 front sub sensor 19 side airbag Sensor 20 Acceleration sensor 21 Inclination sensor 25 Steering angle sensor 27 Steering torque sensor 30 Drive circuit 31 Power steering drive motor (power steering motor) 32 Detection circuit 34 Filter

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) B62D 103: 00 B62D 103: 00 113: 00 113: 00 119: 00 119: 00 127: 00 127: 00

Claims (4)

[Claims] 1. A detecting means mounted on an automobile for detecting a collision applied to a vehicle, and outputting a control signal corresponding to a magnitude of the collision applied to the vehicle based on information data detected by the detecting means. And a second control unit that starts a control program stored and stored in advance according to the magnitude of the collision based on the control signal output from the first control unit. The control means controls the power plant system control unit in accordance with the control program to control the power plant system control unit so that the vibration amplitude of the steering device becomes equal to or less than a set value in the case of a collision in which the airbag does not deploy. In the case of a collision in which the airbag deploys and a travel restriction request is made to lower the vehicle speed, a failure diagnosis of the steering device is executed and the vehicle speed is determined based on the diagnosis result. A steering system failure diagnostic device for an automobile, wherein a driving restriction request for restricting the steering is made. 2. The apparatus according to claim 1, wherein the first control means detects a magnitude of the collision based on an output value of one of an airbag module sensor, an acceleration sensor, and a tilt sensor. Car steering system failure diagnosis device. 3. The system according to claim 2, wherein the second control unit detects occurrence of a malfunction of the steering device based on any output value of a steering angle, a steering torque, and a power steering drive motor current of the steering device. The vehicle steering system failure diagnosis apparatus according to claim 1 or 2, wherein 4. The steering control system according to claim 2, wherein the second control unit performs a harness check of a steering drive system when performing a failure diagnosis of the steering device in the case of a collision in which the airbag is deployed. The vehicle steering system failure diagnosis apparatus according to claim 1, wherein