JPH02144262A - Steering angle detecting device for vehicle - Google Patents

Abstract

PURPOSE:To make it possible to precisely compensate the neutral position of a steering angle by detecting a running condition of a vehicle by use of a status value detector including either a yaw rate sensor or a G sensor, and by determining such that the vehicle runs straightforward when its detection output signal is below a predetermined value. CONSTITUTION:An ECU receives output signals from a G sensor 10, a yaw rate sensor 14 and a steering sensor 18, and discriminates, at first, the large and small relationship between a vehicle speed V and a predetermined value (a). If V>a, the ECU determines the large and small relationship between the absolute value ¦YR¦ of an output YR from the yaw rate sensor 12 and a predetermined value (b) set by the vehicle speed V, and if ¦YR¦<b, it allows a timer to count, and thus counted value is compared with a predetermined value N. If RC>N, it is determined that the vehicle runs straight-forward so as to determine the steering position as a neutral position. Thereby the neutral position of the steering sensor 18 is compensated in accordance with the result of the determination.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention detects the neutral position of the steering wheel of a vehicle,
The present invention relates to a steering angle detection device for a vehicle to be corrected.

[Prior Art] The neutral position of the steering angle of a vehicle is important as a basic TN information for controlling each part of the vehicle while the vehicle is running. However, the steering of a vehicle has short-period wobbling, and if the neutral position is detected by following this wobbling, the error component is too large, which poses a practical problem, and it is difficult to eliminate detection errors caused by such wobbling. It was a conventional section report.

Japanese Unexamined Patent Publication No. 59-143913 describes a vehicle steering angle center detection device aimed at eliminating detection errors caused by such wandering. This detection device includes a steering wheel angle sensor, a temporary storage section that temporarily stores a center value of the steering wheel (a value indicating a neutral position), and a temporary storage section that temporarily stores the center value of the steering wheel (a value indicating a neutral position), and a temporary storage section that stores the center value of the steering wheel through a switch. It includes a center storage unit to retrieve the center value, and a distance measurement unit that controls the switch on and off after traveling a predetermined distance, and takes in the new center value when the steering center value is maintained updated while traveling for a predetermined distance M. In addition, averaging is performed using a circuit when taking in the center value.

Correction of the steering center value (neutral position) is determined according to the following order.

1. Initial setting: The steering position when the ignition is turned on or when the check mode is released is stored as the center.

2. Center correction condition: 15m every 15±0.5m travel
Center correction is performed when the steering movement remains within ±18@ during this travel distance based on the previous steering position.

3. Center correction method: After setting the balance, the current steering position is set as the steering center during the first correction. From the second time onwards, the following formula is used.

New steering center 15 x (old steering center) / 16 + (steering position 15m before) / 1
6 However, if the steering position 15m in front is within 72° from the old steering center, the old steering wheel should be moved 15m away from the old steering wheel.
The angle shifted by 4° to 5° in the direction of the previous steering position is set as the new steering center.

4. Prohibition of center correction: Do not perform center correction when the vehicle speed is less than 20 km/h.

Issues to be solved by the invention] Conventional issues The above-mentioned conventional structure TEMS (Toyota Electronic
(modulated suspension), if you park the car with the steering wheel in the left position or turn for a long time, the neutral position will shift, and it will take time to return to the original neutral position, and the accuracy of the return position may be poor. It had some problems.

In addition, ECT (Electronic Condroldo)
In the case of the method used in transmissions, time-opening processing is performed, which requires a huge amount of ROM capacity, and correction processing is always performed using the steering angle signal while driving, resulting in a large amount of calculations. In many cases, calculation processing takes time, making it unsuitable for rapid control.Furthermore, since average value processing is performed, accuracy is poor.

The methods using absolute sensors described above are sufficient for TEMS and ECT control, but 4WS (wheel steering) is expected to develop in the future.
It must be said that this method is insufficient for controlling the steering stability of systems such as suspension systems and active suspensions, and therefore there is a problem that the above-mentioned problems must be solved.

Purpose of the Invention The present invention was made in order to solve the above-mentioned problems, and an object thereof is to provide a steering angle detection device for a vehicle that can detect and correct the neutral position of the steering angle at high speed and with high accuracy. shall be.

[Means for Solving the Problems] A steering angle detection device for a vehicle according to the present invention includes a steering sensor that is provided in a steering mechanism of a vehicle and that electrically detects a steering angle, a yaw rate sensor that is provided in the vehicle, and a G. The electronic control unit is provided with an output from a vehicle state quantity detector including at least one of the sensors, an output from a vehicle speed sensor, and an output from the steering sensor. The vehicle speed is monitored by the output from the vehicle speed sensor, and the vehicle running state is detected by a vehicle state quantity detector including either a yaw rate sensor or a G sensor, and the output of the vehicle state quantity detector corresponds to the vehicle speed. When the value is less than a predetermined value, it is determined that the vehicle is traveling straight, and the neutral position of the steering sensor is detected and corrected by using the steering position at this time as a neutral position.

[Function] Since the steering angle detection device for a vehicle according to the present invention performs the above-mentioned means, it uses a sensor called a yaw rate sensor or a G sensor that detects the state quantity of the vehicle without using an absolute type sensor such as a steering sensor. The output from the vehicle speed sensor is input to the electronic control unit to detect the running state of the vehicle, and in parallel, the output from the vehicle speed sensor is input to the electronic control unit to monitor the vehicle speed. When the output of the vehicle status ffi detector is below a predetermined value determined corresponding to the vehicle speed, it is determined that the vehicle is traveling straight, and the neutral position of the steering sensor is detected with the steering position at this time being set as a neutral position. . In this way, the neutral position of the steering wheel can be detected and corrected accurately and quickly with a small amount of calculation.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of a vehicle steering angle detection device according to the present invention. 10 is a G sensor, 12 is a yaw rate sensor, and 14 is a vehicle speed sensor, and the outputs of these sensors 10 and 12.14 are sent to an electronic control unit (ECU) 1.
6 is input.

Further, the output of a steering sensor 18 that is provided in the steering mechanism of the vehicle and that electrically detects the steering angle is connected to the electronic II+ control section 15. The steering sensor 18 is composed of, for example, a potentiometer that electrically detects the steering angle, and can extract an electrical signal corresponding to the steering angle by interlocking with the steering shaft.

The output of the electronic control 16 is connected to a turn signal switch return control and other control systems 20.

Next, the operation of correcting the detection of the neutral position of the steering wheel using the apparatus configured as described above will be described with reference to the flowchart shown in FIG. First, in step 1, information on the vehicle speed outputted from the vehicle speed sensor 14 is sent to the electronic control unit 16.
In step 2, the magnitude relationship between the vehicle speed ■ and the predetermined value a is determined, and if it is not Via, the process returns to step 1. V
In the case of ia, the output YR from the yaw rate sensor 12 is input to the electronic control unit 16, and in step 4, the magnitude relationship between the absolute value IYR of the output YR of the yaw rate sensor 12 and a predetermined value I is determined, and l YRl If IYRI<b, the process returns to step 1. If IYRI<b, a timer (not shown) is counted, and in step 6, the magnitude relationship between the timer count value RC and the predetermined value N is determined. RC>N
If not, return to step 1, and if RC>N, I
Since the state of YRIKb has continued for t seconds, it is determined that the vehicle is traveling straight, the steering position is determined to be the neutral position, and the neutral position of the steering sensor 18 is corrected in step 7. conduct. The magnitude of the yaw rate connection time t for determining that the vehicle is traveling straight varies depending on the vehicle, and the reference value S for determining the magnitude of the yaw rate is a function of the vehicle speed V.

Note that step 3.4 in the flowchart is a horizontal G
The sensor output may also be used, and the yaw rate sensor 1
It is also possible to use both the output of G sensor 2 and the output of G sensor 10.

According to this embodiment configured as described above, there is no need to perform complicated calculations using an absolute type sensor as in the past, and the neutral position of the steering wheel can be detected quickly and accurately with a small amount of calculations. Can be corrected.

[Effects of the Invention] As explained above, the vehicle steering angle detection device according to the present invention includes at least one of a steering sensor provided in a steering mechanism of a vehicle and electrically detecting a steering angle, and a yaw rate center and a G sensor. The configuration includes an electronic control unit that receives as input the output of the vehicle state quantity detector including the vehicle speed sensor, the output of the vehicle speed sensor, and the output of the steering sensor, thereby reducing the amount of calculation without using an absolute type sensor. This has the effect that the neutral position of the steering wheel can be detected and corrected quickly and accurately.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of one embodiment of the present invention, and FIG. 2 is a flow chart for explaining the operation of the embodiment of FIG. 10...G sensor Yaw rate sensor Vehicle speed sensor Electronic control unit Steering sensor control system

Claims (1)

[Claims] A steering sensor provided in a steering mechanism of a vehicle to electrically detect a steering angle, an output of a vehicle state quantity detector including at least one of a yaw rate sensor and a G sensor, and an output of a vehicle speed sensor. and an electronic control unit that receives as input the output of the steering sensor, and the electronic control unit monitors the vehicle speed based on the output from the vehicle speed sensor, and monitors the vehicle speed based on the output of the vehicle state quantity detector. When the output of the vehicle state quantity detector is below a predetermined value determined corresponding to the vehicle speed, it is determined that the vehicle is traveling straight, and the steering position at this time is set as the neutral position. A vehicle steering angle detection device characterized by detecting and correcting a neutral position of a sensor.