JP2022073446A - Sensor device - Google Patents

Abstract

To provide a sensor device with which it is possible to improve the ability of detecting the abnormality of a duty cycle.SOLUTION: A sensor unit 110 outputs a first duty cycle detection signal when a first range in a detection body 200 is detected, and outputs a second duty cycle detection signal which is larger than the first duty cycle when a second range in the detection body 200 is detected. A signal processing unit 120 has a first assessment range that includes the first duty cycle and a second assessment range that includes the second duty cycle. The upper-limit value of the first assessment range and the lower-limit value of the second assessment range are separate. The signal processing unit 120 accepts a detection signal from the sensor unit 110 as input and assesses whether or not the duty cycle of the detection signal is included in the first assessment range or the second assessment range. The signal processing unit 120 assesses the detection signal as being abnormal when the duty cycle of the detection signal inputted from the sensor unit 110 is included in a range between the first assessment range and the second assessment range.SELECTED DRAWING: Figure 2

Description

The present invention relates to a sensor device.

Conventionally, for example, Patent Document 1 has proposed a configuration in which a detection signal is output from a sensor device to a control device. The sensor device outputs a pulse signal as a detection signal. The detection signal contains different information depending on the width of the pulse, that is, the duty ratio.

Japanese Unexamined Patent Publication No. 2005-256842

However, in the above-mentioned conventional technique, the duty ratio may fluctuate when an abnormality occurs in which the signal waveform of the detection signal changes due to a decrease in output voltage or the like. As a result, the control device may erroneously determine the information indicated by the duty ratio.

In view of the above points, it is an object of the present invention to provide a sensor device capable of improving the detectability of an abnormality in the duty ratio.

In order to achieve the above object, in the invention according to claim 1, the sensor device includes a sensor unit (110) and a signal processing unit (120).

The sensor unit detects the first range or the second range in the detector (200), outputs the detection signal of the first duty ratio when the first range is detected, and detects the second range. Outputs a detection signal with a second duty ratio that is larger than the first duty ratio.

The signal processing unit has a first determination range including a first duty ratio and a second determination range including a second duty ratio, and a detection signal is input from the sensor unit so that the duty ratio of the detection signal is the first determination range or the first determination range. 2 The first range or the second range is determined by determining whether or not it is included in the determination range.

The upper limit of the first determination range and the lower limit of the second determination range are separated. The signal processing unit determines an abnormality in the detection signal when the duty ratio of the detection signal input from the sensor unit is included in the range between the first determination range and the second determination range.

According to this, since the upper limit value of the first determination range and the lower limit value of the second determination range are separated, the determination timing of the first range and the determination timing of the second range can be separated. Therefore, even if the duty ratio fluctuates, it is not determined to be in either the first range or the second range. Further, when the duty ratio fluctuates, it can be determined that the duty ratio range that does not belong to both the first range and the second range is a duty abnormality. Therefore, the detectability of the abnormality of the duty ratio can be improved.

The reference numerals in parentheses of each means described in this column and the scope of claims indicate the correspondence with the specific means described in the embodiment described later.

It is a block diagram of the sensor device which concerns on 1st Embodiment. It is a figure which showed the detection signal of the 1st duty ratio and the detection signal of the 2nd duty ratio. It is a figure which showed the detection signal which concerns on 2nd Embodiment. It is a figure which showed the detection signal which concerns on 3rd Embodiment. It is a perspective view which shows the shift range switching system which concerns on 4th Embodiment. It is a figure which showed the detector and the sensor device which concerns on 4th Embodiment.

(First Embodiment)
Hereinafter, one embodiment will be described with reference to the drawings. The sensor device according to the present embodiment is a device for acquiring the range (state) of the position of the detector.

As a detector, the sensor device detects the position of a moving part linked to the operation of the shift position of the vehicle. The sensor device adopts a magnetic detection method. Specifically, the sensor device acquires the state of the shaft by detecting a signal corresponding to the position of the shaft.

The state of the shaft means the position of the shaft when the shift position is operated by the user. For example, the shaft moves in conjunction with parking in the shift position. When the shift position is operated to be in the parking position, the shaft moves axially. This causes the shaft to reflect the parking condition. The position sensor detects the position of the shaft corresponding to parking.

On the other hand, when the shift position is operated to be located in a position other than parking, the shaft reflects the state other than parking. In this case, the position sensor detects a position on the shaft other than the position corresponding to parking. Of course, the shaft may move in conjunction with a position other than parking.

As shown in FIG. 1, the sensor device 100 includes a sensor unit 110 and a signal processing unit 120. The sensor unit 110 generates a detection signal corresponding to the position of the detector 200 based on the change in the magnetic field received from the detector 200 as the detector 200 made of the magnetic material moves.

Specifically, the sensor unit 110 has a detection element (not shown). The detection element is an element in which a bias magnetic field is applied from a magnet (not shown) and the resistance value changes based on a change in the magnetic field received from the detection body 200 as the detection body 200 moves. The detection element is composed of, for example, a plurality of magnetoresistive element pairs. The magnetoresistive element pair is configured as a half-bridge circuit in which two magnetoresistive portions are connected in series.

The magnetoresistive element is, for example, an AMR element (Anisotropic Magneto Resistance; AMR). The detection element may be a GMR element (Giant Magneto Resistance; GMR) or a TMR element (Tunneling Magneto Resistance; TMR).

The detector 200 has, for example, two ranges arranged in one direction along the moving direction. The two ranges are arranged along the moving direction of the detector 200. One range is the first range. The first range corresponds to the state A of the detector 200. The other range is the second range. The second range corresponds to the state B of the detector 200.

The sensor unit 110 detects a first range or a second range in the detector 200. The sensor unit 110 outputs a PWM signal having a duty ratio corresponding to the detection position as a detection signal to the signal processing unit 120. The duty ratio is the ratio of Hi and Lo in one cycle.

The signal processing unit 120 inputs a detection signal from the sensor unit 110, and determines the first range or the second range in the detector 200 by comparing the duty ratio of the detection signal with the threshold value. Therefore, the signal processing unit 120 has a first determination range including the first duty ratio and a second determination range including the second duty ratio.

Further, the signal processing unit 120 has an abnormality determination range for detecting an abnormality in the duty ratio of the detection signal. The signal processing unit 120 outputs the determination result to an external device (not shown). The above is the configuration of the sensor device 100.

Next, the operation of the sensor device 100 will be described. First, the sensor unit 110 generates a detection signal corresponding to the current state of the detector 200 based on the change in the magnetic field received from the detector 200. As shown in FIG. 2, the detection signal is a PWM signal having a period tp.

When the sensor unit 110 detects the first range, that is, the state A in the detector 200, the sensor unit 110 generates a detection signal of the first duty ratio. The range of Lo of the detection signal of the first duty ratio with respect to the threshold value is the Lo interval tA.

When the sensor unit 110 detects the second range, that is, the state B, the sensor unit 110 generates a detection signal having a second duty ratio larger than the first duty ratio. The range of Lo of the detection signal of the second duty ratio with respect to the threshold value is the Lo section tB larger than the Lo section tA. The sensor unit 110 outputs the detection signal to the signal processing unit 120.

The signal processing unit 120 determines whether or not the duty ratio of the detection signal input from the sensor unit 110 is included in the first determination range or the second determination range. The first determination range is a range including the Lo section tA in the range of the period tp. The second determination range is a range including the Lo section tB.

Then, the signal processing unit 120 determines whether or not the duty ratio is included in the first determination range or the second determination range by comparing the duty ratio of the detection signal with the threshold value. For example, it is determined whether or not the duty ratio is a value smaller than the upper limit value of the first determination range, and whether or not the duty ratio is a value larger than the lower limit value of the second determination range. As a result, the signal processing unit 120 determines the first range or the second range as the current position of the detector 200.

Here, as shown in FIG. 2, an error determination margin is provided between the first range (state A) and the second range (state B) of the detector 200 in the period tp. That is, the upper limit value of the first determination range and the lower limit value of the second determination range are separated. The error judgment margin corresponds to the abnormality judgment range. That is, the abnormality determination range is set between the first determination range and the second determination range.

The upper limit of the first determination range is, for example, 16%, and the lower limit of the second determination range is, for example, 80%. That is, when the detection signal switches between 0% and 16% in the period tp, it corresponds to the first range. Further, when the detection signal switches between 80% and 100% in one cycle of the signal, it corresponds to the second range.

On the other hand, when the duty ratio of the detection signal fluctuates due to a decrease in the output voltage or the like, the duty ratio of the detection signal is not included in both the first range and the second range. In this case, the signal processing unit 120 determines that the duty ratio of the detection signal input from the sensor unit 110 is included in the abnormality determination range between the first determination range and the second determination range, and determines the abnormality of the detection signal. do. The signal processing unit 120 outputs a diagnostic signal to an external device.

As described above, since the upper limit value of the first determination range and the lower limit value of the second determination range are separated, the determination timings of the first range and the second range can be separated. Therefore, even if the duty ratio fluctuates, it is not erroneously determined to be in either the first range or the second range. Further, a duty ratio that does not belong to both the first range and the second range can be determined to be a duty abnormality. Therefore, it is possible to improve the detectability of the abnormality of the duty ratio in the sensor device 100.

(Second Embodiment)
In this embodiment, a part different from the first embodiment will be mainly described. In the present embodiment, the detector 200 has, for example, three ranges arranged in one direction along a moving direction. The three ranges are a first range corresponding to the state A of the detector 200, a second range corresponding to the state B of the detector 200, and a third range corresponding to the state C of the detector 200. .. The range of Lo of the detection signal of the third duty ratio with respect to the threshold value is the Lo section tC larger than the Lo section tB.

In this case, as shown in FIG. 3, in the period tp, between the first range (state A) and the second range (state B) of the detector 200, and the second range (state B). An error determination margin corresponding to the abnormality determination range is provided between the third range (state C) and the third range (state C). As a result, the upper limit value of the first determination range and the lower limit value of the second determination range are separated, and the upper limit value of the second determination range and the lower limit value of the third determination range are separated.

Therefore, the signal processing unit 120 determines whether or not the duty ratio of the detection signal is included in any of the first determination range, the second determination range, and the third determination range, thereby determining whether or not the duty ratio of the detection signal is included in any of the first determination range, the second determination range, and the third determination range. Determine the position. Further, the signal processing unit 120 includes the duty ratio of the detection signal in the abnormality determination range between the first determination range and the second determination range, or the abnormality determination range between the second determination range and the third determination range. If so, it is determined that the detection signal is abnormal.

As described above, the state of the detector 200 is not limited to two cases, and the sensor device 100 can also detect three states as in the present embodiment. Of course, four or more states may be detected by providing an abnormality determination range between the determination ranges.

(Third Embodiment)
In this embodiment, the parts different from the first and second embodiments will be mainly described. In the present embodiment, as shown in FIG. 4, an error determination margin corresponding to the abnormality determination range is provided at the beginning and end of the cycle tp. Further, an abnormality determination range is provided between the first range (state A) and the third range (state C) of the detector 200. The second range (state B) may be used instead of the third range (state C).

As described above, the abnormality determination range is not limited to one case, and each determination range may be set to be sandwiched between the abnormality determination ranges. Of course, three or more determination ranges may be set.

(Fourth Embodiment)
In this embodiment, the parts different from each of the above embodiments will be mainly described. In the present embodiment, as shown in FIG. 5, the detector 200 is provided in the shift range switching system 300 for switching the shift range of the vehicle. The shift range switching system 300 includes a motor 310, a shift range switching mechanism 320, and a parking lock mechanism 330.

The motor 310 rotates by being supplied with electric power from a battery mounted on a vehicle (not shown). The motor 310 is a drive source for the shift range switching mechanism 320. The motor 310 is a switched reluctance motor. As the motor 310, any kind such as a DC motor may be used.

A speed reducer (not shown) is provided between the motor shaft of the motor 310 and the output shaft 311. The speed reducer decelerates the rotation of the motor 310 and outputs it to the output shaft 311. As a result, the rotation of the motor 310 is transmitted to the shift range switching mechanism 320.

The shift range switching mechanism 320 has a detent plate 321 and a detent spring 322 as an urging member. The shift range switching mechanism 320 transmits the rotational driving force output from the speed reducer to the manual valve 323 and the parking lock mechanism 330.

The detent plate 321 is a movable component fixed to the output shaft 311 and driven by the motor 310. The direction in which the detent plate 321 separates from the base of the detent spring 322 is the forward rotation direction, and the direction in which the detent plate 321 approaches the base is the reverse rotation direction.

The detent plate 321 is provided with a pin 324 that protrudes in parallel with the output shaft 311. The pin 324 is connected to the manual valve 323. When the detent plate 321 is driven by the motor 310, the manual valve 323 reciprocates in the axial direction. That is, the shift range switching mechanism 320 converts the rotational motion of the motor 310 into a linear motion and transmits it to the manual valve 323.

The manual valve 323 is provided on the valve body 325. When the manual valve 323 reciprocates in the axial direction, the hydraulic pressure supply path to the hydraulic clutch (not shown) is switched, and the engagement state of the hydraulic clutch is switched to change the shift range.

On the side of the detent spring 322 of the detent plate 321, a first valley portion 326, a second valley portion 327, and a mountain portion 328 formed between the two valley portions 326 and 327 are provided. The side closer to the base of the detent spring 322 is the second valley portion 327, and the far side is the first valley portion 326. The first valley portion 326 corresponds to the P range, and the second valley portion 327 corresponds to the notP range other than the P range.

The detent spring 322 is an elastically deformable plate-shaped member, and a detent roller 329 as an engaging member is provided at the tip thereof. The detent spring 322 urges the detent roller 329 toward the center of rotation of the detent plate 321. When a predetermined or greater rotational force is applied to the detent plate 321, the detent spring 322 is elastically deformed, and the detent roller 329 moves between the first valley portion 326 and the second valley portion 327.

By fitting the detent roller 329 into any of the valleys 326 and 327, the swing of the detent plate 321 is restricted. As a result, the axial position of the manual valve 323 and the state of the parking lock mechanism 330 are determined, and the shift range of the automatic transmission (not shown) is fixed. The detent roller 329 fits into the second valley portion 327 when the shift range is the notP range, and fits into the first valley portion 326 when the shift range is the P range.

The parking lock mechanism 330 includes a parking rod 331, a cone 332, a parking lock pole 333, a shaft portion 334, and a parking gear 335. The parking rod 331 is formed in a substantially L shape, and one end 336 side is fixed to the detent plate 321. A cone 332 is provided on the side of the other end 337 of the parking rod 331. The conical body 332 is formed so as to have a diameter reduced toward the other end 337 side. When the detent plate 321 swings in the reverse rotation direction, the cone 332 moves in the P direction.

The parking lock pole 333 abuts on the conical surface of the conical body 332 and is provided so as to be swingable around the shaft portion 334. On the side of the parking gear 335 of the parking lock pole 333, a convex portion 338 that can mesh with the parking gear 335 is provided. When the detent plate 321 rotates in the reverse rotation direction and the conical body 332 moves in the P direction, the parking lock pole 333 is pushed up and the convex portion 338 and the parking gear 335 mesh with each other. On the other hand, when the detent plate 321 rotates in the forward rotation direction and the conical body 332 moves in the notP direction, the meshing between the convex portion 338 and the parking gear 335 is released.

The parking gear 335 is provided on an axle (not shown) so as to be meshable with the convex portion 338 of the parking lock pole 333. When the parking gear 335 and the convex portion 338 mesh with each other, the rotation of the axle is restricted. When the shift range is the notP range, the parking gear 335 is not locked by the parking lock pole 333, and the rotation of the axle is not hindered by the parking lock mechanism 330. Further, when the shift range is the P range, the parking gear 335 is locked by the parking lock pole 333, and the rotation of the axle is restricted.

In the above configuration, the detent plate 321 of the shift range switching mechanism 320 is provided with the detector 200 so that the magnetic field changes according to the rotation of the output shaft 311.

As shown in FIG. 6, the detector 200 has three region portions 201 to 203 corresponding to a plurality of ranges arranged in one direction along the moving direction. Each area portion 201 to 203 is composed of a square plate member 204. Further, each region portion 201 to 203 is configured to be connected in a stepped manner in the moving direction of the detection body 200 in the plane of the detection surface 205 facing the sensor portion 110 of the detection body 200.

"Connected in a stepped manner" means that one of the regions 201 to 203 and the other are connected in the plane of the detection surface 205 so as to be offset in the direction perpendicular to the moving direction. As a result, both end portions, that is, the two long side portions along the moving direction in each region portion 201 to 203 form a stepped shape.

In the detector 200, one end in the moving direction is referred to as the first end 206, and the other end is referred to as the second end 207. The connection portion between the region portion 201 and the region portion 202 is referred to as a first edge 208. The connection portion between the region portion 202 and the region portion 203 is referred to as a second edge 209. Further, the position of the region portion 201 is A, the position of the region portion 202 is B, and the position of the region portion 203 is C.

In the detector body 200, a plate member made of a magnetic material is formed by press working or the like. The detection body 200 may be a separate member from the detent plate 321 or may be formed by, for example, pressing the detent plate 321 if the detent plate 321 is a magnetic material.

The lengths of the region portions 201 to 203 in the moving direction may be the same or may be different. Further, the lengths of the region portions 201 to 203 in the direction perpendicular to the moving direction in the plane of the detection surface 205 may be the same or different.

The sensor unit 110 includes a bias magnet 111 and a detection element 112. The bias magnet 111 and the detection element 112 are housed in the case 101 of the sensor device 100. The bias magnet 111 is arranged with a detection gap of a certain distance with respect to the detection surface 205.

The detection element is an element in which a bias magnetic field is applied from a magnet and a resistance value changes based on a change in the magnetic field received from the detection body 200 as the detection body 200 moves. The detection element is composed of, for example, a plurality of magnetoresistive element pairs. The magnetoresistive element pair is configured as a half-bridge circuit in which two magnetoresistive portions are connected in series.

The signal processing unit 120 acquires a detection signal from the detection element 112 of the sensor unit 110, compares the detection signal with the threshold value, and is one of a plurality of ranges based on the combination of the magnitude relationship between the detection signal and the threshold value. The position of the detector 200 is specified as the position of the range.

When the combination of the magnitude relation between the detection signal and the threshold value corresponds to the first end portion 206 to the first edge 208 of the detector body 200, the position determination is “A”. Alternatively, when the combination of the magnitude relationship between the detection signal and the threshold value corresponds to the first edge 208 to the second edge 209 of the detector 200, the position determination is “B”. Alternatively, when the combination of the magnitude relationship between the detection signal and the threshold value corresponds to the second edge 209 to the second end 207 of the detector 200, the position determination is “C”.

The signal processing unit 120 generates an output signal corresponding to the position determination and outputs the output signal to the external device.

As described above, the detector 200 may be configured to have a plurality of region portions 201 to 203 configured in a stepped shape. Since there is a possibility of erroneous detection in the detector 200 having a stepped portion, it is possible to notify the occurrence of an abnormality at an early stage.

The detector 200 may be fixed to a component such as a shaft. Alternatively, in the detector body 200, the region portions 201 and 203 at both ends may be fixed to the shaft.

(Other embodiments)
The configuration of the sensor device 100 shown in each of the above embodiments is an example, and the configuration is not limited to the configuration shown above, and other configurations that can realize the present invention can be used. For example, the use of the sensor device 100 is not limited to that of a vehicle, and can be widely used for industrial robots, manufacturing equipment, and the like as a device for detecting the position of a moving part.

100 Sensor device 110 Sensor unit 120 Signal processing unit 200 Detector

Claims (3)

When the first range or the second range of the detector (200) is detected, the first range is detected, the detection signal of the first duty ratio is output, and when the second range is detected, the second range is detected. A sensor unit (110) that outputs a detection signal with a second duty ratio that is larger than the 1 duty ratio, and
It has a first determination range including the first duty ratio and a second determination range including the second duty ratio, and the detection signal is input from the sensor unit so that the duty ratio of the detection signal is the first determination range or A signal processing unit (120) that determines the first range or the second range by determining whether or not it is included in the second determination range.
Including
The upper limit of the first determination range and the lower limit of the second determination range are separated from each other.
The signal processing unit is a sensor device that determines an abnormality in the detection signal when the duty ratio of the detection signal input from the sensor unit is included in the range between the first determination range and the second determination range. .. The detector has a plurality of region portions (201 to 203) corresponding to the first range and the second range.
The first aspect of the present invention, wherein the plurality of regions are connected in a stepwise manner in the moving direction of the detector in the surface of the detection surface (205) facing the sensor of the detector. Sensor device. The sensor device according to claim 1 or 2, wherein the detector is a movable component that moves in conjunction with the operation of the shift position of the vehicle.

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