JP4417685B2 - Steering method for vehicle, computer program for executing steering method for vehicle, control device, and steering for vehicle - Google Patents

Description

  The present invention relates to a method for driving active steering for a vehicle.

  In the following, the steering referred to as active steering, unlike so-called steer-by-wire steering, always has a mechanical connection between the steering wheel and the steered wheel. Active steering, on the one hand, seeks to improve the comfort for the driver of the vehicle, for example by providing servo assistance or by changing the steering gear ratio according to speed and / or steering angle. On the other hand, the active steering enables the active safety of the vehicle to be increased by dynamic stabilization control during driving.

  Both can be achieved in particular by a tatami mat transmission with an electric servomotor. The superposition transmission allows the superposition angle to be added to the steering angle set by the driver of the vehicle via the steering wheel. For example, when entering the garage, the steering angle set by the driver of the vehicle is set. In addition, the steering amount of the steered wheel is increased. When the vehicle is oversteered, the steering angle set by the driver of the vehicle can be reduced by the superimposed transmission and the servomotor in order to stabilize the vehicle.

  Of course, active steering, like all other steering of the vehicle, is desired to comply with greater safety requirements. Therefore, in active steering, it is necessary to recognize as soon as possible and uniquely the errors that occur, so that the vehicle occupant is not at risk based on these errors. Yes.

  Therefore, the present invention has been made in view of such problems, and the object of the present invention is to recognize as quickly and uniquely as possible an error that occurs in the active steering of a vehicle. A new and improved method of driving a vehicle steering is provided.

  In order to solve the above problems, according to an aspect of the present invention, the steering angle of the steering wheel is detected by the steering wheel rotation angle sensor, and the rotation angle of the pinion of the steering gear box is detected by the pinion rotation angle sensor. The rotation angle of the first servomotor of the transmission is detected by the first servomotor rotation angle sensor, the first servomotor is driven according to the external input amount, and the probability of the signal generated by the pinion rotation angle sensor is There is provided a method of driving active steering for a vehicle, characterized in that it is examined by comparison of signals generated by a steering wheel rotation angle sensor and a first servomotor rotation angle sensor.

  By adopting such a configuration, all of the above three sensors can be obtained without additional effort by checking the probability of the signals of the pinion rotation angle sensor, the steering wheel rotation angle sensor, and the first servo motor rotation angle sensor. , And whether the active steering is operating as desired.

Of course, when the signals detected by the steering wheel rotation angle sensor and the first servo motor rotation angle sensor are compared with the signals detected by the pinion rotation angle sensor, the steering wheel rotation angle sensor, the pinion rotation angle sensor, The transmission ratio between the servomotor rotation angle sensors of 1 is taken into consideration. This means that the total steering angle can be calculated from the servo motor rotation angle sensor signal and the steering wheel rotation angle sensor signal as follows:
_{δ LW, gesamt = i1 × δ} LR + i2 × δ SM
Can be done by being calculated according to: In the above formula,
δ _{LW, gesamt} total steering angle δ _LR steering wheel angle δ _SM servo motor angle i1: first gear ratio i2: second gear ratio

In particular, when the difference is detected from the total steering angle δ _{LW, gesamt} calculated according to the above formula and the pinion angle δ _Ritzel measured by the pinion angle sensor, and the difference exceeds a preset limit value, Checking the probability described above is easy when the erroneous behavior of the steering, particularly the sensors involved, is estimated.

  In order to improve the recognition of the error function of the active steering, it may be effective if an error signal is output only when the above difference exceeds a preset limit value during a predetermined interval. It has been revealed. Thereby, it is possible to exclude a very short time deviation of the total steering angle from the pinion angle which is not based on the error function of the active steering. Such very short deviations can be caused by differences in the sampling rates of the various rotational angle sensors, for example.

  When checking the probability of the signals of the pinion rotation angle sensor, the steering wheel rotation angle sensor, and the first servo motor rotation angle sensor according to the present invention, the limit value from which an error signal is output is Further improvements can be made if determined according to the running speed and / or the rotational speed of the steering wheel. There is a fixed relationship between the rotational speed of the steering wheel and the torque transmitted from the steering wheel to the steering column. This constant relationship can be used to estimate the torque transmitted from the steering wheel based on the rotational speed of the steering wheel without torque measurement.

  In particular, it is effective if the above-mentioned limit value, which is a criterion for error signal output, is determined according to the torque transmitted between the steering wheel and the steering column. This is because the torsion of the steering column and, in some cases, the play that occurs when rotational motion is transmitted from the steering wheel to the steering gear box is significantly dependent on torque. Thereby, according to the present invention, it is possible to minimize the limit value according to the driving state of the active steering and to recognize the error quickly and with greater reliability. Therefore, the potential danger to which a passenger of a vehicle equipped with an active steering according to the present invention is exposed is reduced.

  The advantage of the present invention is that the superposition transmission for superimposing the operation motion of the first servo motor on the steering motion, the steering wheel rotation angle sensor for detecting the steering motion of the steering wheel, and the steering gear box steering A steering wheel having a pinion rotation angle sensor for detecting the rotation movement of the pinion driven by the wheel, a first servo motor rotation angle sensor for detecting an operation movement of the first servo motor, and a control device. The steering device for a vehicle with a steering gear box for converting the steering movement of the wheel, steering column and steering wheel into the steering movement of the steered wheel of the vehicle also causes the control device to take any one of the methods described above. It is suitable for carrying out By, it is obtained.

  Other advantages and preferred forms of the invention will become apparent from the following drawings, description thereof and claims.

  As described in detail above, according to the present invention, by checking the probability of the signals of the pinion rotation angle sensor, the steering wheel rotation angle sensor, and the first servo motor rotation angle sensor, all three of these sensors can be briefly and properly arranged. It can be checked whether it is operating and whether the active steering is operating as desired. This makes it possible to recognize errors in active steering quickly and with greater reliability, thus reducing the potential danger to the vehicle occupant.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a schematic configuration diagram schematically showing the configuration of the active steering in the first embodiment of the present invention. When the driver steers, the steering operation of the driver is transmitted to the steering column 3 composed of three parts via the steering wheel 1, and the steering column 3 drives the steering gear box 5. The steering gear box 5 is formed as a rack and pinion steering gear box in the present embodiment shown in FIG. Of the rack and pinion steering gear box, only the pinion 7 is shown in FIG. 1, and this pinion 7 cooperates with a rack (not shown). The steering gear box 5 converts the rotational movement of the steering wheel 1 into a substantially linear movement of the steering tie rod 9, and the steering tie rod 9 is operatively connected to a steered wheel (not shown) of the vehicle.

Above the portion in 3a of the steering column 3, steering wheel angle sensor 11 for detecting a steering operation or a steering wheel rotation angle [delta] _LR of the driver is located. A superposition transmission 13 is provided in a portion 3 c below the steering column 3. The superposition transmission 13 includes a first servo motor 15 and a first servo motor rotation angle sensor 17.

  The superposition transmission 13 can add or subtract an additional angle to the rotation angle of the steering wheel 1, so that the rotation angle of the pinion 7 driven by the output shaft (not shown) of the superposition transmission. Can be larger, equal to or smaller than the rotation angle of the steering wheel 1. The superposition of the rotational movements of the steering wheel 1 and the first servo motor 15 can be performed, for example, via a planet gear not shown in detail in FIG.

  In order to detect the rotation angle of the pinion 7, a pinion rotation angle sensor 19 is provided on the pinion 7. The steering wheel rotation angle sensor 11, the first servo motor rotation angle sensor 17, and the pinion rotation angle sensor 19 are connected to the control device 23 via a signal line 21. The same applies to the first servomotor 15, which can be driven by the control device 23 via the signal line 21.

  Since the steering wheel 1 and the pinion 7 and the first servo motor 15 and the pinion 7 are coupled, the rotation angle of the pinion 7 is changed from the rotation angle of the steering wheel 1 and the rotation angle of the servo motor 15. It can be calculated based on the ratio. The method according to the present embodiment checks the probability of the calculation result of the gear ratio described above, thereby checking the steering wheel rotation angle sensor 11, the first servo motor rotation angle sensor 17, the pinion rotation angle sensor 19, and the remaining. It is checked whether the active steering is operating normally.

In this case, the total steering angle δ _{LW, GESAMT} is calculated, and the signal δ _LR of the steering wheel rotation angle sensor 11 and the signal δ _{SM of} the first servo motor rotation angle sensor are included in this calculation as input amounts. Furthermore, the gear ratios i1 and i2 between the steering wheel 1 and the pinion 7 and between the servo motor 15 and the pinion 7 are taken into account.

When the calculated total steering angle δ _{LW, GESAMT} is _deviated from the signal δ _Ritzel of the pinion rotation angle sensor by a preset difference angle δ _Diff that is greater than a preset limit value S, In particular, errors of the steering wheel rotation angle sensor 11, the first servo motor rotation angle sensor 17, and the pinion rotation angle sensor 19 described above are estimated, and an error signal is output from the control device 23. This error signal can, for example, cause a warning lamp to be lit on the vehicle dashboard, or activate other instructions to the driver of the vehicle. In addition, the drive mode of the active steering can be changed instead. For example, by providing only the functions that are inevitably most necessary for the steering function, it is possible to switch to the emergency driving mode, in which case the comfort of steering is sacrificed.

  Hereinafter, the method based on the first embodiment of the present invention will be described in detail with reference to the flowchart shown in FIG.

  In order to improve the safety of the active steering, the second servo motor 25 and the second servo motor rotation angle sensor 27 are arranged in parallel with the first servo motor 15 and the first servo motor rotation angle sensor 18. Is provided. Therefore, the servo motor and the attached rotation angle sensor are redundantly formed, thereby further improving the reliability of the electronic active steering equipment.

  FIG. 2 shows a flowchart of the operating sequence of the method according to the present embodiment for driving the active steering. In the first step 31, the active steering is driven. This is because the control device 23 is initialized and it is checked whether signals from all sensors, in particular, the steering wheel rotation angle sensor 11, the first servo motor rotation angle sensor 17, and the pinion rotation angle sensor 19 exist. Means. Further, it is checked whether another input signal 29 exists in the control device 23. Such other input signals 29 may be, for example, vehicle speed, vehicle yaw rate, and other signals. The active steering is controlled by the control device 23 using these signals and the signals generated by the steering wheel rotation angle sensor 11, the first servo motor rotation angle sensor 17 and the pinion rotation angle sensor 19 described above.

In a second step 33, the steering angle [delta] _LR of the steering wheel 1 is detected by the steering wheel rotational angle sensor 11. Further, the rotation angle δ _Ritzel of the pinion 7 of the steering gear box 5 is detected by the pinion rotation angle sensor 19, and the rotation angle δ _SM of the first servo motor 15 of the superimposed transmission 13 is detected by the first servo motor rotation angle sensor 17. Detected. Further, the first servo motor 15 is driven according to another external input amount 29.

Next, in the third step 35, the probability of the signal δ _Ritzel detected by the pinion rotation angle sensor 19 is determined by the steering wheel rotation angle detected by the steering wheel rotation angle sensor 11 and the first servomotor rotation angle sensor 17. It is checked by comparing the signal δ _LR with the servo motor rotation angle signal δ _SM . This is performed as follows based on the gear ratios i1 and i2 among the steering wheel rotation angle sensor 11, the pinion rotation angle sensor 19, and the second servomotor rotation angle sensor:

First, the total steering angle δ _{LW, gesamt} is obtained from the signal δ _{SM of} the servo motor rotation angle sensor 17 and the signal δ _{LR of the} steering wheel rotation angle sensor 11 according to the following formula:
_{δ LW, gesamt = i1 × δ} LR + i2 × δ SM

Thereafter, the angle difference δ _Diff is obtained from the total steering angle and the pinion angle δ _Ritzel measured by the pinion rotation angle sensor 19. Thereafter, it is compared whether the angle difference δ _Diff exceeds a preset limit value S (step 37).

If the angle difference δ _Diff exceeds a preset limit value S, an error signal is output. This is indicated by step 39 in FIG. When the angle difference δ _Diff does not exceed the preset limit value S, the active steering based on the present embodiment returns to before the second step 33 described above.

The method according to the present embodiment is further improved when an error signal is output only when the angle difference δ _Diff exceeds a preset limit value S during a preset time interval Δt. Is done. By this measure, it is possible to filter out deviations occurring in a short time that may be caused by, for example, a difference in sampling rate between the rotation angle sensors 11, 17 and 19.

  Furthermore, it is advantageous if the limit value S is determined according to the torque transmitted between the steering wheel and the steering column. This is because the torsion in the steering column 3 and the undesired, but possibly existing play in the links connecting the individual parts of the steering column 3 are taken into account. As a result, the limit value S can be minimized, so that errors that occur can be recognized more quickly.

  If the torque transmitted between the steering wheel 1 and the steering column 3 is not detected, the limit value S can optionally be determined according to the running speed and / or the rotational speed of the steering wheel 1. This can be done by storing this type of limit value in a characteristic curve or map, as in the embodiment described above.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  The present invention can be applied to a method for driving an active steering for a vehicle, and in particular, a steering wheel, a steering column, and a steering wheel for converting a steering motion of the steering wheel into an operation motion of a wheel steered by the vehicle. Steering gear driven by the steering wheel, a gearbox, a superposition transmission for superimposing the operation motion of the first servo motor on the steering motion, a steering wheel rotation angle sensor for detecting the steering angle of the steering wheel A vehicle equipped with a pinion rotation angle sensor for detecting the rotation movement of a pinion of a box, a first servo motor rotation angle sensor for detecting an operation movement of a first servo motor, and a control device. Those who drive active steering It can be applied to.

1 shows a simplified first embodiment of an active steering system according to the invention. It is a flowchart explaining the embodiment of the method based on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steering wheel 3 Steering column 5 Steering gear box 7 Pinion 9 Steering tie rod 11 Steering wheel angle sensor 13 Superposition transmission 15 1st servomotor 17 1st servomotor rotation angle sensor 19 Pinion rotation angle sensor 21 Signal line 23 Controller 25 Second servo motor 27 Second servo motor rotation angle sensor

Claims (14)

A steering wheel angle sensor for detecting the steering movement of the steering wheel;
A pinion rotation angle sensor for detecting the rotational movement of the pinion driven by the steering wheel;
A first servo motor rotation angle sensor for detecting an operation motion of the first servo motor;
In a method of driving a steering of a vehicle comprising:
A pinion rotation angle signal (δ _Ritzel ) detected by the pinion rotation angle sensor, a steering wheel rotation angle signal (δ _LR ) detected by the steering wheel rotation angle sensor and the first servo motor rotation angle sensor, and Inspecting the pinion rotation angle signal by comparing with a servo motor rotation angle signal (δ _SM );
A method of driving a vehicle steering, characterized by: A superposition transmission for superimposing the operation motion of the first servomotor on the steering motion;
A steering wheel rotation angle sensor for detecting the steering movement of the steering wheel;
A pinion rotation angle sensor for detecting rotational movement of a pinion of a steering gear box driven by the steering wheel;
A first servo motor rotation angle sensor for detecting an operation motion of the first servo motor;
Steering wheel rotation angle signal (δ _LR ), pinion rotation angle signal (δ _Ritzel ), and servo motor rotation detected by the steering wheel rotation angle sensor, the pinion rotation angle sensor, and the first servo motor rotation angle sensor A controller for evaluating the angle signal (δ _SM ) and driving the first servomotor;
In the method of driving a vehicle steering, the steering gear box converts a steering motion of the steering wheel, a steering column, and the steering wheel into an operation motion of a wheel steered by the vehicle.
The pinion rotation angle signal (δ _Ritzel), the steering wheel rotation angle signal (δ _LR), and the by comparing the servo motor rotation angle signal (δ _SM), comprising the step of examining the pinion rotation angle signal thing,
A method of driving a vehicle steering, characterized by: When inspecting the steering wheel rotation angle signal (δ _LR ), the pinion rotation angle signal (δ _Ritzel ), and the servo motor rotation angle signal (δ _SM ), the steering wheel rotation angle sensor, the pinion rotation angle sensor, and the The method for driving a vehicle steering according to claim 1 or 2, characterized in that a gear ratio (i1, i2) between the first servomotor rotation angle sensors is taken into account. From the servo motor rotation angle signal (δ _SM ) and the steering wheel rotation angle signal (δ _LR ), the total steering angle (δ _{LW, gesumt} ) is _expressed by the following formula:
_{δ LW, gesamt = i1 × δ} LR + i2 × δ SM
The vehicle steering driving method according to claim 3, wherein the vehicle steering driving method is calculated according to: An angle difference (δ _Diff ) is obtained from the total steering angle (δ _{LW, gesamt} ) and the pinion rotation angle signal (δ _Ritzel ), and the angle difference (δ _Diff ) is set to a preset limit value (S). 4. The method of driving a vehicle steering according to claim 3, wherein an error signal is output when the value exceeds the limit. The error signal is output only when the angle difference (δ _Diff ) exceeds the preset limit value (S) during a preset time interval (Δt). The method of driving a vehicle steering according to claim 5.   The method of driving a vehicle steering according to any one of claims 4 to 6, wherein the limit value (S) is set according to a rotational speed of the steering wheel.   The method for driving a vehicle steering according to any one of claims 4 to 7, wherein the limit value (S) is set according to a traveling speed of the vehicle.   The vehicle steering according to any one of claims 4 to 6, wherein the limit value (S) is set in accordance with a torque transmitted between the steering wheel and the steering column. Driving method.   The method for driving a vehicle steering according to any one of claims 4 to 9, wherein the limit value (S) is stored in a map or a characteristic curve. In a computer program for steering a vehicle,
A computer program for executing the vehicle steering driving method according to any one of claims 1 to 10. The computer program according to claim 11, wherein the computer program can be stored on a memory medium. In a control device for steering a vehicle,
11. A control apparatus for steering a vehicle, characterized in that the vehicle steering driving method according to claim 1 is executed. A superposition transmission for superimposing the operation motion of the first servomotor on the steering motion;
A steering wheel rotation angle sensor for detecting the steering movement of the steering wheel;
A pinion rotation angle sensor for detecting the rotational movement of the pinion of the steering gear box driven by the steering wheel;
A first servo motor rotation angle sensor for detecting an operation motion of the first servo motor;
A controller for driving the first servo motor by evaluating signals generated by the steering wheel rotation angle sensor, the pinion rotation angle sensor, and the first servo motor rotation angle sensor;
In the steering for a vehicle, the steering gear box converts a steering motion of the steering wheel, a steering column, and the steering wheel into an operation motion of a wheel steered by the vehicle.
A steering for a vehicle, wherein the control device executes the steering driving method for a vehicle according to any one of claims 1 to 10.

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