JP3581946B2 - Vehicle steering system - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicle steering system for steering a vehicle in response to a driver's operation.
[0002]
[Prior art]
The steering of the vehicle is performed by operating a steering means disposed inside the vehicle compartment, for example, by rotating a steering wheel, and externally disposing the steering wheel (generally, a front wheel) for steering. This is done by telling the steering mechanism.
In recent years, steering assisting actuators such as hydraulic cylinders and electric motors have been arranged in the middle of the steering mechanism, and the actuators are driven based on the operating force applied to the steering wheel for steering. 2. Description of the Related Art Power steering devices (power steering devices) configured to assist the operation of a steering mechanism in accordance with the rotation of a vehicle by the force generated by an actuator and reduce the labor burden on a driver for steering have become widespread.
[0003]
However, in such a conventional vehicle steering system, a mechanical connection between a steering wheel, which is a steering means, and a steering mechanism is necessary, and the position of the steering wheel inside the vehicle compartment is outside the vehicle compartment. There is a problem that it is limited to a position where connection with the steering mechanism is possible, and even if the steering wheel is arranged so as to be connectable, a complicated connection structure is required to realize the connection. This is a factor that hinders weight reduction of the vehicle and simplification of the assembly process.
[0004]
Japanese Utility Model Publication No. 2-29017 discloses a steering device for a vehicle, which is a linkless power steering device for solving such a problem. This steering apparatus for a vehicle has a steering wheel separated from a steering mechanism, and an electric motor as a steering actuator in the middle of the steering mechanism, similarly to an actuator for assisting steering in a power steering apparatus. A control means comprising a microprocessor controls the driving of the electric motor based on the detection result of the operation direction and the operation amount of the steering wheel, thereby performing steering according to the operation of the steering wheel. It has become.
[0005]
A steering wheel that is not mechanically connected to the steering mechanism is provided with a reaction force actuator that is a reaction force control unit including an electric motor. The reaction force actuator drives and controls the motor based on the detection result of the vehicle speed and the steering amount of the steering wheel, based on the reaction force instruction signal output by the control means, and controls the steering wheel to change the vehicle speed and the steering amount. It becomes large or small accordingly, and applies a reaction force toward the neutral position. As a result, the steering can be performed with the same feeling as a general vehicle steering device (connection type steering device) in which the steering wheel and the steering mechanism are mechanically connected.
[0006]
The linkless vehicle steering system configured as described above provides a new steering system that replaces the steering wheel, such as levers and pedals, in addition to the aforementioned objects such as increasing the degree of freedom in arranging the steering wheel and reducing the weight of the vehicle. The present invention is useful for the development of automobile technology in the future, such as the realization of means, the detection of guidance signs on the road surface, the realization of an automatic driving system according to driving information such as the reception of satellite information, etc.
[0007]
[Problems to be solved by the invention]
However, based on the detection result of the operation direction and the operation amount of the steering means such as the steering wheel, drive control of a steering mechanism such as an electric motor for steering is performed to calculate a reaction force to be applied to the steering means such as the steering wheel. When the control means for outputting the reaction force instruction signal fails, there is a problem that there is no means for detecting the failure.
[0008]
To detect an abnormality in the force to be applied to the steering wheel, the direction of the axial force of the rack formed by linking the knuckle arms connected to the wheels at both ends and the direction of the steering torque applied to the steering wheel are compared for a predetermined time. As described above, there is an electric power steering apparatus (Japanese Patent Publication No. Hei 8-29709) that determines an abnormality when the two do not match, but detects an abnormality in the steering torque applying means in the conventional coupled power steering apparatus. It is for doing.
The present invention has been made in view of the circumstances described above, and in a linkless vehicle steering system, a steering mechanism such as an electric motor for steering is drive-controlled and provided to steering means such as a steering wheel. It is an object of the present invention to provide a vehicular steering system capable of promptly detecting a failure of a control means for obtaining a desired reaction force when the control means fails.
[0009]
[Means for Solving the Problems]
A steering device for a vehicle according to a first aspect of the present invention includes a steering device operated by a driver, a steering mechanism for steering a wheel, a steering amount detection device for detecting a steering amount of the steering device, and a steering device. A vehicle steering system comprising: a reaction force control unit that applies a reaction force; and a control unit that controls the steering mechanism and the reaction force control unit in accordance with the steering amount. Failure detection means for detecting a failure of the control means based on a reaction force instruction signal given to the meansA vehicle speed detecting means for detecting a traveling speed of the vehicle, and an axial force detecting means for detecting an axial force applied to an axis for changing the direction of the wheel and a direction of the axial force by a road surface reaction force received by the wheel from the road surface. A vehicle speed comparison unit that compares the vehicle speed detected by the vehicle speed detection unit with a predetermined speed; and a reaction direction indicated by the direction of the axial force detected by the axial force detection unit and the reaction force instruction signal. First direction comparing means for comparing the direction of force with the direction of force, wherein the vehicle speed comparing means determines that the vehicle speed is lower than the predetermined speed, and the first direction comparing means determines the direction of the axial force. When it is determined that the direction of the reaction force does not match theIt is characterized by the following.
[0010]
In this vehicle steering system, when the control unit that controls the steering angle of the steering mechanism to increase or decrease the steering angle and obtains the reaction force to be applied to the steering unit and outputs the reaction force instruction signal fails, the failure detection unit outputs the reaction force instruction signal. The failure is detected based on the signal.The vehicle speed detecting means detects the running speed of the vehicle, and the axial force detecting means detects the axial force applied by the road surface reaction force. In the failure detecting means, the vehicle speed comparing means compares the vehicle speed detected by the vehicle speed detecting means with a predetermined speed, and the first direction comparing means shows the direction of the axial force detected by the axial force detecting means and the reaction force instruction signal. Compare with the direction of the reaction force. Then, when the vehicle speed comparing means determines that the vehicle speed is lower than the predetermined speed and the first direction comparing means determines that the direction of the axial force does not match the direction of the reaction force, the failure of the control means is determined. To detect.
Essentially, the direction of the reaction force applied to the steering means as a simulation force of the reaction force applied to the steering means due to the road surface reaction force must match the direction of the road surface reaction force. Therefore, at a low speed where the detection signal of the axial force resulting from the road surface reaction force is large enough to be distinguished from noise, if the directions do not match, it is determined that the control means has failed.This makes it possible to quickly detect a failure of the control means.
[0013]
No.2The vehicle steering device according to the present invention,Steering means operated by a driver, a steering mechanism for steering wheels, steering amount detection means for detecting a steering amount of the steering means, reaction force control means for applying a steering reaction force to the steering means, A vehicle steering device comprising: a steering mechanism that controls the steering mechanism and the reaction force control means in accordance with the steering amount; based on a reaction force instruction signal given to the reaction force control means by the control means, Failure detection means for detecting a failure of the control means;Vehicle speed detecting means for detecting a traveling speed of the vehicle, the failure detecting means comprising: vehicle speed comparing means for comparing the vehicle speed detected by the vehicle speed detecting means with a predetermined speed; and a direction of a reaction force to be applied to the steering means. Direction determining means for determining based on the steering amount, and a second direction comparing means for comparing the direction of the reaction force determined by the direction determining means and the direction of the reaction force indicated by the reaction force instruction signal, The vehicle speed comparing means determines that the vehicle speed is higher than the predetermined speed, and the second direction comparing means determines the direction of the reaction force determined by the direction determining means and the direction of the reaction force indicated by the reaction force instruction signal. When it is determined that the control means does not match, the control unit determines that the control unit is out of order.
[0014]
In this vehicle steering system,If the control means that controls the steering angle of the steering mechanism to increase or decrease the steering angle and obtains the reaction force to be applied to the steering means and outputs a reaction force instruction signal fails, the failure detection means detects the failure based on the reaction force instruction signal I do.Vehicle speed detecting means detects the running speed of the vehicle. In the failure detecting means, the vehicle speed comparing means compares the vehicle speed detected by the vehicle speed detecting means with a predetermined speed, and the direction determining means determines the direction of the reaction force to be applied to the steering means by the steering amount detected by the steering amount detecting means. And the second direction comparing means compares the direction of the reaction force determined by the direction determining means with the direction of the reaction force indicated by the reaction force instruction signal. The failure detecting means determines that the vehicle speed is higher than the predetermined speed by the vehicle speed comparing means, and the second direction comparing means determines the direction of the reaction force determined by the direction determining means and the reaction force indicated by the reaction force instruction signal. When it is determined that the direction does not match, it is determined that the control means is out of order.
[0015]
In the failure detection means, the direction determination means determines the direction of the reaction force to be applied to the steering means based on the steering amount detected by the steering amount detection means, and the second direction comparison means determines the direction of the reaction force determined by the direction determination means. The direction of the force is compared with the direction of the reaction force indicated by the reaction force instruction signal obtained by the control means. At this time, of course, the two directions must match. Therefore, at a high speed at which both reaction forces are large enough to be easily compared, if the directions do not match, it is determined that the control means has failed. This makes it possible to quickly detect a failure of the control means.
[0016]
No.3The vehicle steering device according to the present invention,Steering means operated by a driver, a steering mechanism for steering wheels, steering amount detection means for detecting a steering amount of the steering means, reaction force control means for applying a steering reaction force to the steering means, A vehicle steering device comprising: a steering mechanism that controls the steering mechanism and the reaction force control means in accordance with the steering amount; based on a reaction force instruction signal given to the reaction force control means by the control means, Failure detection means for detecting a failure of the control means;The failure detecting means includes a first calculating means for calculating a reaction force to be applied to the steering means based on the steering amount, a reaction force obtained by the first calculating means and a reaction force indicated by the reaction force instruction signal. And a comparing means for comparing the difference calculated by the second calculating means with a predetermined value, wherein the comparing means calculates the difference calculated by the second calculating means as a predetermined value. When it is determined that the value is larger than the predetermined value, it is determined that the control unit is out of order.
[0017]
In this vehicle steering system,If the control means that controls the steering angle of the steering mechanism to increase or decrease the steering angle and obtains the reaction force to be applied to the steering means and outputs a reaction force instruction signal fails, the failure detection means detects the failure based on the reaction force instruction signal I do.The failure detecting means calculates the reaction force to be applied to the steering means by the first calculating means based on the steering amount detected by the steering amount detecting means. The second calculating means calculates the difference between the reaction force calculated by the first calculating means and the reaction force indicated by the reaction force instruction signal obtained by the control means, and the comparing means calculates the difference by the second calculating means. The calculated difference is compared with a predetermined value. The failure detecting means determines that the control means has failed when the comparing means determines that the difference calculated by the second calculating means is larger than a predetermined value.
[0018]
The failure detecting means calculates the reaction force to be applied to the steering means by the first calculating means separately from the control means based on the steering amount detected by the steering amount detecting means, and the control means by the second calculating means. Calculate the difference from the calculated reaction force. This difference can be regarded as an error, and when this error is large, it is determined that the control means has failed. This makes it possible to quickly detect a failure of the control means.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described with reference to the drawings showing the embodiments.
FIG.One shotIt is a block diagram showing composition of a steering device for vehicles concerning light. The vehicle steering system includes a steering mechanism 1 for causing a pair of steering wheels 10, 10 arranged on the left and right sides of a vehicle body (not shown) to perform a steering operation, and a steering mechanism separated from the steering mechanism 1. A steering wheel 2 as means, an electric motor 3 for applying a reaction force to the steering wheel 2, a reaction force control unit 7 which uses a microprocessor to drive and control the electric motor 3, and is disposed in the middle of the steering mechanism 1. A steering mechanism control unit 8 for controlling the driving of the steering motor 5 and a main control unit (control means) 4 using a microprocessor. The operation of the main control unit 4 in accordance with the operation of the steering wheel 2 enables The steering motor 5 is driven to operate the steering mechanism 1.
[0020]
As is well known, the steering mechanism 1 includes both ends of a steering shaft 11 that extends in the left-right direction of the vehicle body and slides in the axial direction, and knuckle arms 12 that support the wheels 10. Each tie rod 13 is connected by another tie rod 13, and the knuckle arms 12, 12 are pushed and pulled through the tie rods 13 by sliding the steering shaft 11 in both directions to steer the wheels 10, 10 left and right. In this steering, the rotation of the steering motor 5 coaxially formed in the middle of the steering shaft 11 is converted into sliding of the steering shaft 11 by an appropriate motion conversion mechanism.
[0021]
The rotation of the steering shaft 11 around the axis is restricted by rotation restricting means (not shown) interposed between the steering shaft 11 and the steering shaft housing 14. The steering (steering of the steering wheels 10, 10) according to the rotation of the steering motor 5 is performed. The current flowing through the steering motor 5 is detected by the current sensor 8a and provided to the main control unit 4.
[0022]
The steering angles of the wheels 10 and 10 thus steered are detected by the steering angle sensor 16 using the relative sliding position between the steering shaft housing 14 on one side of the steering motor 5 and the steering shaft 11 as a medium. The output of the steering angle sensor 16 is provided to the main control unit 4 together with the output of the rotary encoder 15 that detects the rotational position of the steering motor 5.
The tie rods 13, 13 are provided with axial force sensors (axial force detecting means) 9, 9 for detecting an axial force applied by the road surface reaction force that the wheels 10, 10 receive from the road surface, and each output of the axial force sensors 9, 9 is provided. Is given to the main control unit 4 and the reaction force control unit 7.
[0023]
An electric motor 3 (for example, a DC motor) that applies a reaction force to the steering wheel 2 is fixedly attached to a housing of the rotating shaft 30, and its rotational movement is performed by an electromagnetic clutch 3a and by a worm gear mechanism 3b. The rotation direction is converted and transmitted to the rotation shaft 30. The reaction force control section 7 constitutes a reaction force control means together with the electric motor 3 and the electromagnetic clutch 3a.
The steering wheel 2 is coaxially fixed to a protruding end on one side of a rotating shaft 30, and the protruding end on the other side is connected to an appropriate portion of a vehicle body (not shown) by a torsion spring 31 having a predetermined elasticity. I have.
[0024]
The electric motor 3 is driven in both forward and reverse directions by energization from a reaction force control unit 7 in accordance with a reaction force instruction signal given from a main control unit 4, and is operated by a steering wheel 2 attached to one end of a rotating shaft 30. An operation of applying a force (reaction force) in a direction opposite to the direction is performed. Therefore, it is necessary to apply a steering torque against the reaction force generated by the electric motor 3 for the rotation operation of the steering wheel 2, and the steering torque applied to the steering wheel 2 in this manner is detected by the torque sensor 32. You. The output of the torque sensor 32 is provided to the main control unit 4.
[0025]
The operation amount (steering amount) of the steering wheel 2 is detected by the rotary encoder 33 as the steering amount detecting means, including the operation direction. This detection result is provided to the main control unit 4 and the reaction force control unit 7.
Further, a current flowing through the electric motor 3 is detected by a current sensor 7 a and provided to the main control unit 4 and the reaction force control unit 7.
[0026]
The torsion spring 31 interposed between the other end of the rotating shaft 30 and a part of the vehicle body rotates the rotating shaft 30 by its elasticity at the time of stopping the rotating operation performed as described above, and performs steering. It functions to return the wheel 2 to a predetermined neutral position. This return is necessary for returning the steering wheel 2 in accordance with the return operation of the wheels 10, 10 in the straight traveling direction that occurs on the mechanically separated steering mechanism 1 side.
[0027]
As described above, the state of steering actually occurring on the steering mechanism 1 side is given to the main control unit 4 as input from the rotary encoder 15 and the steering angle sensor 16, and the steering wheel as steering means is provided. 2 are provided as inputs from the torque sensor 32 and the rotary encoder 33, respectively, and in addition to these, the main control unit 4 is provided with the output of the vehicle speed sensor 6 for detecting the running speed of the vehicle. ing. The output of the vehicle speed sensor 6 is also provided to a reaction force control unit 7.
[0028]
On the other hand, as described above, the output of the main control unit 4 includes a reaction force control unit 7 for applying a reaction force to the steering wheel 2 and a steering mechanism control unit 8 for causing the steering mechanism 1 to perform a steering operation. , And the reaction force control unit 7 and the steering mechanism control unit 8 perform different control operations according to the instruction signal from the main control unit 4.
The main control unit 4 determines the reaction force to be applied to the steering wheel 2 so as to be large or small according to the level of the vehicle speed given as an input from the vehicle speed sensor 6, for example. A reaction force control for giving a reaction force instruction signal to the control unit 7 is performed.
[0029]
Further, the main control unit 4 recognizes an operation angle including an operation direction of the steering wheel 2 based on an input from the rotary encoder 33, and recognizes an actual steering that is recognized based on an input of a steering angle sensor 16 attached to the steering mechanism 1. A steering angle deviation from the angle is obtained, and this steering angle deviation is corrected so as to be larger or smaller in accordance with the vehicle speed given as an input from the vehicle speed sensor 6 to obtain a target steering angle, and the target steering angle is obtained. The steering control operation for driving the steering motor 5 is performed until this operation. At this time, the input from the rotary encoder 15 is used as a feedback signal for checking whether or not the steering motor 5 has reached a desired rotational position.
The output of the rotary encoder 33 is also supplied to the reaction force control unit 7, which recognizes the operation angle including the operation direction of the steering wheel 2.
[0030]
Hereinafter, the operation of the vehicle steering system according to the first and second aspects of the present invention will be described with reference to a flowchart showing the operation.
FIG. 2 is a flowchart showing the operation of the vehicle steering system according to the first and second inventions. The reaction force controller 7 reads the vehicle speed detected by the vehicle speed sensor 6 (S10) and compares this vehicle speed with a predetermined speed (S12). When the vehicle speed is equal to or lower than the predetermined speed (S12), the axial force detected by the axial force sensor 9 is read (S14), and a reaction force instruction signal indicating the reaction force obtained by the main control unit 4 is read (S16).
[0031]
Next, the reaction force control unit 7 compares the direction of the reaction force indicated by the read reaction force instruction signal with the direction of the axial force, and the direction of the reaction force indicated by the reaction force instruction signal is correct (both coincide). Is checked (S18). As a result, when the direction of the reaction force indicated by the reaction force instruction signal is incorrect (both do not match) (S18), it is determined that the main control unit 4 that has determined the reaction force indicated by the reaction force instruction signal has failed. (S20).
When the vehicle speed exceeds the predetermined speed (S12), the axial force and the reaction force instruction signal are not read (S14, 16), and the process proceeds to the reaction force control operation other than the failure detection.
[0032]
FIG.24 is a flowchart showing the operation of the vehicle steering system according to the present invention. No.2The configuration of the vehicle steering system according to the invention is the same as that of the above-described vehicle steering system.One shotExcept for the configuration and control contents of the vehicle steering system according to the present invention, the description is the same, and therefore the description is omitted.
The reaction force controller 7 of the vehicle steering system reads the vehicle speed detected by the vehicle speed sensor 6 (S22), and compares this vehicle speed with a predetermined speed (S24). If the vehicle speed is equal to or higher than the predetermined speed (S24), the operation angle (steering steering angle) of the steering wheel 2 is read from the output of the rotary encoder 33 (S26), and the reaction force to be applied according to the read operation angle is obtained. The direction is determined (S27), and then a reaction force instruction signal indicating the reaction force obtained by the main control unit 4 is read (S28).
[0033]
Next, the reaction force control unit 7 compares the direction of the reaction force indicated by the read reaction force instruction signal with the direction of the reaction force to be applied (S27), and determines the reaction force indicated by the reaction force instruction signal. (S30), it is checked whether the direction is correct (the direction of the reaction force to be applied according to the steering angle). As a result, when the direction of the reaction force indicated by the reaction force instruction signal is incorrect (not the direction of the reaction force to be applied according to the steering angle) (S30), the reaction force indicated by the reaction force instruction signal is obtained. It is determined that the main control unit 4 has failed (S32).
When the vehicle speed is lower than the predetermined speed (S24), the steering angle is read (S26), the direction of the reaction force to be applied according to the steering angle (S27), and the reaction instruction signal is read (S28). ) Is not performed, and the process proceeds to a reaction force control operation other than the failure detection.
[0034]
FIG.34 is a flowchart showing the operation of the vehicle steering system according to the present invention. No.3The configuration of the vehicle steering system according to the invention is the same as that of the above-described vehicle steering system.One shotExcept for the configuration and control contents of the vehicle steering system according to the present invention, the description is the same, and therefore the description is omitted.
The reaction force controller 7 of the vehicle steering system reads the axial force F of the tie rod 13 detected by the axial force sensor 9 (S34), and reads the vehicle speed V detected by the vehicle speed sensor 6 (S36). Next, the operation angle (steering steering angle) θ of the steering wheel 2 is read from the output of the rotary encoder 33 (S38), and the standard reaction torque T is calculated (S40).
[0035]
FIG. 5 is a flowchart showing an operation in which the reaction force control unit 7 calculates the standard reaction force torque T (S40). The reaction force control unit 7 obtains a basic reaction force torque corresponding to the tie rod axial force F from a table storing the tie rod axial force F-basic reaction force torque TB characteristic in a proportional relationship as shown in FIG. The TB is read (S50).
Next, as shown in FIG. 6B, the reaction force control unit 7 has a minimum value slightly larger than 0, gradually increases to a predetermined speed, and rapidly increases from the predetermined speed, and 1 is an upper limit. The vehicle speed coefficient KV corresponding to the vehicle speed V is read from the table storing the vehicle speed coefficient KV-vehicle speed V characteristic (S52).
[0036]
Next, as shown in FIG. 6C, the reaction force control unit 7 is in a proportional relationship up to the predetermined steering angle θ, and is 1 when the steering angle is larger than the predetermined steering angle θ. The vehicle speed coefficient Kθ corresponding to the steering angle θ is read from a table storing the Kθ-steering angle θ characteristic (S54).
Next, the reaction force controller 7 calculates the standard reaction torque T = KV · Kθ · TB (S56) and returns.
[0037]
After calculating the standard reaction torque T (S40), the reaction control unit 7 reads the reaction instruction torque TM (reaction instruction signal) from the main control unit 4 (S42).
FIG. 7 is a flowchart illustrating an operation in which the main control unit 4 calculates a steering reaction torque T (reaction instruction torque TM). The main controller 4 reads the axial force F of the tie rod 13 detected by the axial force sensor 9 (S58), and reads the vehicle speed V detected by the vehicle speed sensor 6 (S60). Next, the operation angle (steering steering angle) θ of the steering wheel 2 is read from the output of the rotary encoder 33 (S62).
[0038]
Next, the main control unit 4, like the reaction force control unit 7, uses a table storing the tie rod axial force F-basic reaction force torque TB characteristic in a proportional relationship as shown in FIG. The basic reaction torque TB corresponding to the tie rod axial force F is read (S64).
Next, as shown in FIG. 6B, the main control unit 4 determines that the minimum value is slightly larger than 0, gradually increases to a predetermined speed, and rapidly increases from the predetermined speed, and 1 is an upper limit of the vehicle speed coefficient. A vehicle speed coefficient KV corresponding to the vehicle speed V is read from a table storing the KV-vehicle speed V characteristics (S66).
[0039]
Next, as shown in FIG. 6C, the main control section 4 is in a proportional relationship up to the predetermined steering angle θ, and is 1 when the steering angle is larger than the predetermined steering angle θ. Reading the vehicle speed coefficient Kθ corresponding to the steering angle θ from the table storing the steering angle θ characteristic (S68).
Next, the main control unit 4 calculates the steering reaction force torque T = KV · Kθ · TB (S70) and sets it as the reaction force instruction torque TM.
[0040]
After reading the reaction force instruction torque TM (S42), the reaction force control unit 7 calculates a deviation ΔT = T−TM between the standard reaction force torque T and the reaction instruction torque TM (S44), and calculates the deviation ΔT as a predetermined value. The value is compared with the value (S46). As a result, when the deviation ΔT is equal to or larger than the predetermined value (S46), it is determined that the main control unit 4 that has calculated the reaction force instruction torque is out of order (S48).
When the reaction force instruction torque is less than the predetermined value (S46), the process directly proceeds to the reaction force control operation other than the failure detection.
[0041]
The vehicle steering system shown in FIG. 8 is the same as the vehicle steering system shown in FIG.One shotThe configuration is substantially the same as the configuration of the vehicle steering system according to the present invention, except that the torsion spring 31 interposed between the other end of the rotating shaft 30 of the steering wheel 2 and a part of the vehicle body is omitted. I have.
In the vehicle steering system equipped with the twisting spring 31, the electromagnetic clutch 3a is disengaged at the time of failure, and the steering wheel 2 is returned to a predetermined neutral position by the restoring force of the twisting spring 31. The steering feeling becomes too light, and the driver may feel uneasy.
[0042]
In this vehicle steering system, the steering feeling of the steering wheel 2 is simply increased by the motor friction of the electric motor 3 without disengaging the electromagnetic clutch 3a at the time of failure, and the steering feeling of the steering wheel 2 becomes too light. Eliminate anxiety. Since a control current does not flow through the electric motor 3 at the time of failure, motor friction caused by electromagnetic induction suppresses rotation of the steering wheel 2. Other operations are the same as those described above.One shotSince the operation is the same as that of the vehicle steering system according to the present invention, the description is omitted.
As a result, anxiety due to the steering feeling of the steering wheel 2 becoming too light at the time of failure can be eliminated, and the torsion spring 31 and its mounting mechanism can be omitted, and the number of parts can be reduced.
[0043]
The above embodiment is an example of the vehicle steering apparatus according to the present invention, and does not limit the configurations of the electric motor 3 and the steering motor 5 as reaction force actuators. As a matter of course, it goes without saying that other steering means such as a lever and a joystick can be used instead of the steering wheel 2.
[0044]
【The invention's effect】
According to the vehicular steering apparatus according to the present invention, when the control means for driving and controlling the steering mechanism such as the electric motor for steering and calculating the reaction force to be applied to the steering means such as the steering wheel fails, the Failure can be detected quickly.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a vehicle steering system according to the present invention.
FIG. 2One shotIt is a flowchart which shows operation | movement of the vehicle steering device which concerns on light.
FIG. 324 is a flowchart showing the operation of the vehicle steering system according to the present invention.
FIG. 434 is a flowchart showing the operation of the vehicle steering system according to the present invention.
FIG. 5 is a flowchart illustrating a routine of a standard reaction torque calculation by a reaction control unit.
6A and 6B are graphs showing characteristics of a basic reaction torque and a coefficient used for a standard reaction torque calculation, wherein FIG. 6A is a graph showing a basic reaction torque TB-tie rod axial force F characteristic, and FIG. A graph showing a vehicle speed coefficient KV-vehicle speed V characteristic, and (c) is a graph showing a steering steering angle coefficient Kθ-steering steering angle θ characteristic.
FIG. 7 is a flowchart illustrating an operation of calculating a reaction force instruction torque of a main control unit.
FIG. 8 is a block diagram showing a configuration of a vehicle steering system according to the present invention.
[Explanation of symbols]
1 Steering mechanism
2 Steering wheel (steering means)
3 electric motor (reaction force control means)
3a Electromagnetic clutch (reaction force control means)
4 Main control unit (control means)
5 Steering motor
6. Vehicle speed sensor (vehicle speed detection means)
7 Reaction force control unit (reaction force control means, failure detection means)
9 Axial force sensor (axial force detecting means)
13 Tie rod
15 Rotary encoder
16 Steering angle sensor
30 rotation axis
33 rotary encoder (steering amount detection means)

Claims (3)

Steering means operated by a driver, a steering mechanism for steering wheels, steering amount detection means for detecting a steering amount of the steering means, reaction force control means for applying a steering reaction force to the steering means, Control means for controlling the steering mechanism and the reaction force control means according to the steering amount;
Failure detection means for detecting a failure of the control means based on a reaction force instruction signal given to the reaction force control means by the control means ; vehicle speed detection means for detecting a traveling speed of the vehicle; An axial force applied to an axis for changing the direction of the wheel by force, and an axial force detecting means for detecting a direction of the axial force, wherein the failure detecting means includes a vehicle speed detected by the vehicle speed detecting means, a predetermined speed, Vehicle speed comparing means, and first direction comparing means for comparing the direction of the axial force detected by the axial force detecting means with the direction of the reaction force indicated by the reaction force instruction signal, wherein the vehicle speed comparing means However, when the control unit determines that the vehicle speed is lower than the predetermined speed and the first direction comparison unit determines that the direction of the axial force does not match the direction of the reaction force, the control unit fails. characterized in that it determined to be Dual steering system. Steering means operated by a driver, a steering mechanism for steering wheels, steering amount detection means for detecting a steering amount of the steering means, reaction force control means for applying a steering reaction force to the steering means, Control means for controlling the steering mechanism and the reaction force control means according to the steering amount;
The control unit includes a failure detection unit that detects a failure of the control unit based on a reaction force instruction signal given to the reaction force control unit, and a vehicle speed detection unit that detects a traveling speed of the vehicle. A vehicle speed comparison unit that compares the vehicle speed detected by the vehicle speed detection unit with a predetermined speed, a direction determination unit that determines a direction of a reaction force to be applied to the steering unit based on the steering amount, and the direction determination unit. A second direction comparing unit that compares the determined direction of the reaction force with the direction of the reaction force indicated by the reaction force instruction signal, wherein the vehicle speed comparison unit determines that the vehicle speed is higher than the predetermined speed. When the second direction comparing means determines that the direction of the reaction force determined by the direction determination means does not match the direction of the reaction force indicated by the reaction force instruction signal, the control means is determined to have failed. car, characterized in that the judgment Use steering system. Steering means operated by a driver, a steering mechanism for steering wheels, steering amount detection means for detecting a steering amount of the steering means, reaction force control means for applying a steering reaction force to the steering means, Control means for controlling the steering mechanism and the reaction force control means according to the steering amount;
Failure detection means for detecting a failure of the control means based on a reaction force instruction signal given to the reaction force control means by the control means, wherein the failure detection means determines a reaction force to be applied to the steering means by the steering amount. First calculating means for calculating the difference between the reaction force calculated by the first calculating means and the reaction force indicated by the reaction force instruction signal; and the second calculating means. Comparing means for comparing the calculated difference with a predetermined value, wherein when the comparing means determines that the difference calculated by the second calculating means is larger than the predetermined value, it is determined that the control means has failed. A vehicle steering device for determining .

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