JPH076790B2 - Steering center position detector - Google Patents

Description

TECHNICAL FIELD The present invention relates to a center position detecting device for a steering wheel in an automobile or the like.

[Conventional technology]

The steering of an automobile makes a plurality of left and right rotations about its center position. For example, if it makes less than two rotations left and right, there are a total of three neutral points (one center and one left and right). . Although it is easy to detect this neutral point, it is not easy to detect which point is the center position. Conventionally, when detecting the center position of the steering wheel, each neutral point is detected, and then the center position is detected by other means.

[Problems to be Solved by the Invention]

In the conventional steering center position detecting device, since the neutral points are detected as described above and the other means are used, the structure is complicated and it takes a long time to perform the detection. there were.

The present invention has been made in view of these problems, and provides a center position detecting device for a steering wheel, which has a simple structure and can surely detect the center position in a short time.

[Means for Solving the Problems]

A center position detecting device for a steering wheel according to the present invention is a center position detecting device for a steering device, which makes a plurality of left and right rotations about a center position. Sensor signal that outputs a detection signal of the above and outputs a motion detection signal corresponding to each rotation operation of the left and right when the steering wheel slightly rotates left and right, a timer that operates with the detection signal of the neutral point, and the left and right The counter is provided with counters for respectively inputting the minute rotation motion detection signals and counting the pulses thereof, and comparators for respectively comparing the respective output signals of the counter with preset data, which can be obtained within the set time of the timer. The center position of the steering wheel is detected from the comparison result and the neutral point detection signal. Those were Unishi.

Further, the center position detecting device for a steering wheel according to the present invention comprises the sensor portion described above by an encoder having a code disk that rotates together with the steering wheel.

[Action]

In the steering center position detecting device of the present invention, the detection signal of the neutral point is output from the sensor section, and the operation detection signal corresponding to the minute rotational movement of the steering wheel is output. Then, the operation detection signal is compared with preset data, and the center position of the steering wheel is detected from the comparison result and the neutral point detection signal.

〔Example〕

FIG. 1 is a circuit configuration diagram showing an embodiment of the present invention.
In the figure, reference numeral 1 denotes a sensor section for detecting the operation of a steering wheel (not shown). The sensor section 1 passes through an amplifier 2, and when the steering wheel is in the vicinity of the center position or in a position where the steering wheel is rotated a plurality of times, the neutral point is set. Detection signal Φ ₀ is output, and when the steering wheel slightly rotates left and right, operation detection signals (pulses) Φ ₁ and Φ ₂ corresponding to the rotation operation are output. 3 is a timer that operates with the neutral point detection signal Φ ₀ , 4a and 4b are counters that input the operation detection signals Φ ₁ and Φ ₂ , respectively, and count their pulses, and 5a and 5b are counters 4a and 4b, respectively. A comparator for comparing the output signals (n-bit digital signals) A ₁ and A ₂ with preset data (n-bits) B ₁ and B _2, and when A ₁ > B ₁ , the comparator 5a outputs “H”. (High level) signal is output and A ₂ >
When B _2, the comparator 5b outputs a signal of "H". Reference numeral 6 is a data storage unit for storing the data B ₁ and B ₂ , 7 is an OR circuit, and 8 is an AND circuit. The output signal V ₀ of the AND circuit 8 serves as a center position detection signal.

Next, the operation will be described.

Detection signals Φ ₁ and Φ ₂ from the sensor unit 1 that detects the operation of the steering are input to the counters 4a and 4b, respectively.
Then, the digital output signals (counter values) A ₁ and A _{2 of the} counters 4a and 4b are compared with preset data B ₁ and B ₂ by the comparators 5a and 5b, respectively, and as described above, A ₁ > The output of the comparator 5a becomes "H" when B _{1 and} the comparator when A ₂ > B ₂
The output of 5b becomes “H”. Therefore, A ₁ > B ₁ or A ₂ > B ₂
At this time, the output of the OR circuit 7 becomes "H".

On the other hand, when the steering is at the neutral position, the sensor unit 1
Detection signal [Phi ₀ becomes "H" from, timer 3 as shown in FIG. 2 at this time is started. The output of this timer 3 maintains "L" (low level) for ₁ second when the detection signal Φ _{0 at the} neutral point is "H", and then "H" for ₂ seconds.
And repeat this. This T ₂ seconds is the time during which the counters 4a and 4b can be reset, so the counters 4a and 4b can be reset to T ₁
Data is cleared every second.

The output of the OR circuit 7 is input to the AND circuit 8, where
AND condition with the neutral point detection signal is taken, and this AND circuit 8
Outputs a steering center position detection signal V ₀ . That is, this detection signal V ₀ indicates that the steering is at the neutral position and A ₁ > B ₁ or A ₂ > within T ₁ seconds.
Only when the condition of B ₂ is satisfied, the "H" level is set, and at this time, it is detected that the steering is at the center position.

The motion detection signals φ ₁ and φ ₂ are signals that detect the motion of steering the steering wheel in order to keep going straight when the vehicle normally goes straight,
Specifically, it detects a minute rotation of about ± 5 °.

As described above, when the vehicle advances straight ahead, the steering is slightly rotated to keep the vehicle straight, but when the vehicle turns right or left, the minute rotation is hardly performed.

In this way, the minute movement of the steering wheel and its operation time are used as the criteria for detecting the center position, and when the neutral point of the steering wheel is detected, the small movement of the steering wheel is confirmed several times. Can be detected with high probability. At this time, the above-mentioned probability can be further increased by appropriately setting the number of times of minute operation of the steering wheel and the detection time. Also,
Unlike the conventional case, the center position is not determined only by the relative movement of the steering wheel, so that the center position can be reliably detected in a short time with a simple configuration.

As the sensor unit 1, for example, an encoder having a code disc 9 as shown in FIG. 3 can be used.
In this encoder, the code disk 9 is a reflector for detecting the neutral point.
It is a ring-shaped reflecting plate including 10, and when the light from the light source 11 is reflected by the reflecting portion, it is collected by the condenser lens 12. Then, the photosensor 13 such as a phototransistor whose phase is shifted by 90 ° from the reflection plate operates, whereby each detection signal Φ ₀ ,
Φ ₁ and Φ ₂ are output.

〔The invention's effect〕

As described above, according to the present invention, the neutral position of the steering wheel is detected, and the center position is detected by confirming a few small movements. Therefore, the steering wheel can be reliably operated in a short time with a simple configuration. It is possible to obtain the effect of being able to detect the center position of.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit configuration diagram showing an embodiment of the present invention, FIG. 2 is a timing chart showing its operation, and FIG. 3 is a configuration diagram showing an example of the sensor section of FIG. Is. 1 ... Sensor 3 ... Timer 4a, 4b ... Counter 5a, 5b ... Comparator 6 ... Data storage 7 ... OR circuit 8 ... AND circuit 9 ... Sign disc

Claims (2)

[Claims] 1. A center position detecting device for a steering wheel, which makes a plurality of rotations to the left and right around a center position,
The neutral point detection signal is output when the steering wheel is near the center position or a plurality of rotations from the center position, and when the steering wheel slightly rotates to the left and right, the motion detection signals corresponding to the left and right rotation operations are output. A sensor unit that outputs, a timer that operates by the detection signal of the neutral point, a counter that inputs the operation detection signal of the left and right minute rotations and counts the pulse, and an output signal of each of the counters is set in advance. A center position detecting device for the steering wheel, the center position of the steering wheel is detected from the comparison result obtained within the set time of the timer and the detection signal of the neutral point. . 2. The center position detecting device for a steering wheel according to claim 1, wherein the sensor portion comprises an encoder having a code disc that rotates together with the steering wheel.