JP5638900B2 - Magnetic sensor device - Google Patents

Description

  The present invention relates to a magnetic sensor device.

  As a conventional technique, a moving body to which a cylindrical magnet is fixed, first and second GMR (Giant Magneto Resistive effect) sensors that are arranged to face the peripheral surface of the magnet and detect the tilt amount of the moving body, A third GMR sensor having a detection surface arranged at a position not parallel to any of the detection surfaces of the first and second GMR sensors, and at least first to first based on detection values by the first to third GMR sensors. There is known a moving body position detection apparatus including a determination circuit that determines a failure of any one of the three GMR sensors (see, for example, Patent Document 1).

  The first to third GMR sensors are installed in a vertical direction from the surface of the substrate by inserting terminals into holes formed in the substrate and soldering.

  The determination circuit includes an addition circuit for adding the detection values obtained by the first and second GMR sensors, a value obtained by multiplying the value added by the addition circuit by a predetermined coefficient, and a detection value obtained by the third GMR sensor. And a comparison circuit for comparison.

  The moving body position detection device determines that at least one of the first to third GMR sensors has failed when the multiplied value does not match the detection value by the third GMR sensor.

  However, in the conventional mobile body position detection device, it is difficult to accurately arrange the first to third GMR sensors, the detection values vary, and it becomes difficult to accurately set the predetermined coefficient. There is a problem with detection accuracy.

JP 2009-115645 A

  An object of the present invention is to provide a magnetic sensor device that detects a failure with high accuracy.

One embodiment of the present invention includes a first magnetic sensor that outputs a first linear output signal in response to a change in a magnetic field, and an output that is substantially the same as the first linear output signal in response to a change in the magnetic field. Calculating the difference between the second and third magnetic sensors that output the second and third linear output signals and the first linear output signal and a first offset value that is not zero. An offset unit that generates a signal and calculates a difference between the third linear output signal and a second offset value that is not zero to generate a second offset signal; the first offset signal; and the first offset signal Calculating a first difference between the first linear output signal and a second difference between the first linear output signal and the second offset signal, and calculating the first difference When it becomes larger than the first offset value When it is determined that at least one of the first and second magnetic sensors has failed and the calculated second difference is greater than the second offset value, the first and third magnetic sensors Provided is a magnetic sensor device including a failure determination unit that determines that at least one has failed.

Another aspect of the present invention includes a first magnetic sensor that outputs a first linear output signal in response to a change in a magnetic field, and substantially the same as the first linear output signal in response to a change in the magnetic field. A difference between a second magnetic sensor that outputs a second linear output signal that is output and a first offset value that is not zero and the second linear output signal is calculated to generate a first offset signal the second linear output signal and the offset portion for generating a second offset signal by calculating a difference between the second offset value is not zero, the first linear output signal is the first offset signal A failure determination unit that determines that the first or second magnetic sensor has failed when the first linear output signal becomes smaller than the second offset signal, or when the first linear output signal becomes smaller than the second offset signal. Sensor device To provide.

  According to the present invention, a failure can be detected with high accuracy.

FIG. 1A is a part of a circuit diagram of the first magnetic sensor IC according to the first embodiment of the invention, and FIG. 1B is a schematic diagram showing input / output of the first magnetic sensor IC. FIG. 4C is a schematic diagram showing input / output of the second magnetic sensor IC, and FIG. 4D is a schematic diagram showing a shift pattern of the shift device. FIG. 2A is a graph showing the relationship between the operation voltage and the output voltage (V) of the main magnetic sensor and the first and second sub magnetic sensors according to the first embodiment of the present invention. ) Is a block diagram relating to the shift device. FIG. 3 is a flowchart relating to the operation of the first magnetic sensor IC according to the first embodiment of the invention. FIG. 4 is a circuit diagram of a magnetic sensor IC according to the second embodiment of the present invention. FIG. 5 is a flowchart relating to the operation of the magnetic sensor IC according to the second embodiment of the present invention.

[First embodiment]
(Configuration of the first magnetic sensor IC)
FIG. 1A is a circuit diagram relating to a shift signal and a diagnosis signal of a first magnetic sensor IC (Integrated Circuit) according to the first embodiment of the present invention, and FIG. 1B is a first magnetic sensor. Schematic diagram showing input / output of the IC, (c) is a schematic diagram showing input / output of the second magnetic sensor IC, and (d) is a schematic diagram showing a shift pattern of the shift device.

  The first magnetic sensor IC1 as the magnetic sensor device in the present embodiment is mounted on, for example, a shift device described later of the vehicle. The first magnetic sensor IC1 detects the operation position of the shift lever based on, for example, a change in the magnetic field due to the movement of a magnet 50 provided on a shift lever (described later) of the shift device. The device on which the first magnetic sensor IC1 is mounted is not limited to the shift device, and is widely used for devices that output an output signal corresponding to the operation position of the operation unit.

  In addition, the shift device is a double device that further includes a second magnetic sensor IC3 having the same configuration and function as the first magnetic sensor IC1.

  The first and second magnetic sensor ICs 1 and 3 are disposed to face each other with a substrate 52 (see FIG. 2B), which will be described later, in the shift device, for example. For example, the first and second magnetic sensors IC1 and IC3 may change the selection signal 1a of the first magnetic sensor IC1, the selection signal 3a of the second magnetic sensor IC3, the first signal by the change of the magnetic field due to the movement of the magnet 50, for example. The shift signal 1b of the magnetic sensor IC1 and the shift signal 3b of the second magnetic sensor IC3 are configured to have the same output. The arrangement of the first and second magnetic sensor ICs 1 and 3 is not limited to the above, and for example, two magnetic sensors may be arranged in an overlapping manner as long as each output is the same output.

  Since the second magnetic sensor IC3 has the same configuration as the first magnetic sensor IC1, a specific configuration of the first magnetic sensor IC1 will be described below.

  The first magnetic sensor IC1 includes, for example, a main magnetic sensor 10 as a first magnetic sensor, first and second sub magnetic sensors 11 and 12 as second and third magnetic sensors, and an offset unit. Operational amplifiers 16 and 19, operational amplifiers 22 and 23 as calculation units, and a failure determination unit 24.

As shown in FIGS. 1A to 1C, for example, the first and second magnetic sensor ICs 1 and 3 have a voltage _Vcc applied to one terminal and the other terminal grounded. The first magnetic sensor IC1 includes a main magnetic sensor 10, a first sub magnetic sensor 11, a second sub magnetic sensor 12, operational amplifiers 13, 16, 19, 22, 23, a failure determination unit 24, and the like. It is packaged. The second magnetic sensor IC3 is packaged in the same manner as the first magnetic sensor IC1.

  FIG. 2A is a graph showing the relationship between the operation voltage and the output voltage (V) of the main magnetic sensor and the first and second sub magnetic sensors according to the first embodiment of the present invention. ) Is a block diagram relating to the shift device. FIG. 2A shows the output voltage when the main magnetic sensor 10 and the first and second sub magnetic sensors 11 and 12 are normal.

  The main magnetic sensor 10 of the first magnetic sensor IC1 is composed of, for example, a plurality of known MR (magnetic resistance) elements, and detects the operation position in the select direction and the shift direction of the shift pattern 4 shown in FIG. Is configured to do. Here, the select direction is, for example, a direction connecting the operation position 41 (M) and the operation position 44 (N) as shown in FIG. The shift direction is, for example, a direction orthogonal to the select direction. The main magnetic sensor 10 and the first and second sub magnetic sensors 11 and 12 may be composed of magnetic sensors such as Hall elements and GMR elements.

  For example, the main magnetic sensor 10 outputs Lo as the select signal 1a when the magnet 50 is in any of the operation positions 40 to 42, and when the magnet 50 is in any of the operation positions 43 to 45, the select signal It is configured to perform digital output that outputs Hi as 1a.

  The main magnetic sensor 10 is configured to output a shift side linear output signal 10a as a first linear output signal corresponding to the shift direction of the shift pattern 4 shown in FIG. For example, as shown in FIG. 2A, the shift-side linear output signal 10a is generated between the operation position 40 (+) and the operation position 42 (−), and between the operation position 43 (R) and the operation position 45 (D). The interval is linear output.

The shift-side linear output signal 10a is input to the non-inverting input terminal of the operational amplifier 13, for example, as shown in FIG. The shift-side linear output signal 10a is, for example, the midpoint potential of the resistors 14 and 15, and is adjusted by the voltage V _ref applied to the inverting input terminal of the operational amplifier 13, and from the first magnetic sensor IC1 as the shift signal 1b. Is output. Note that the shift-side linear output signal 10a may be output as the shift signal 1b without being adjusted by the voltage _Vref , for example.

  For example, the first and second sub magnetic sensors 11 and 12 have the same configuration as the MR element that detects the operation position of the main magnetic sensor 10 in the shift direction.

  For example, as shown in FIG. 2A, the first sub magnetic sensor 11 outputs a shift-side linear output signal 11a as a second linear output signal that is the same output as the shift-side linear output signal 10a. It is configured. For example, the first sub magnetic sensor 11 is disposed in proximity to the main magnetic sensor 10 so as to have the same linear output as the main magnetic sensor 10.

The shift-side linear output signal 11a is input from, for example, a non-inverting input terminal of the operational amplifier 16. The shift-side linear output signal 11a is, for example, the midpoint potential of the resistor 17 and the resistor 18, and is offset by the offset value _Voff1 as the first offset value applied to the inverting input terminal side of the operational amplifier 16. Offset signal 16a.

For example, as shown in FIG. _{2A, the} voltage of the first offset signal 16a increases from the shift signal 1b by the offset value V _off1 .

  For example, as shown in FIG. 2A, the second sub magnetic sensor 12 outputs a shift-side linear output signal 12a as a third linear output signal that is the same output as the shift-side linear output signal 10a. It is configured. For example, the second sub magnetic sensor 12 is disposed close to the main magnetic sensor 10 so as to have the same linear output as the main magnetic sensor 10.

The shift-side linear output signal 12a is input from, for example, a non-inverting input terminal of the operational amplifier 19. The shift-side linear output signal 12a is, for example, the midpoint potential of the resistor 20 and the resistor 21, and is offset by the offset value _Voff2 as the second offset value applied to the inverting input terminal side of the operational amplifier 19. Offset signal 19a.

For example, as shown in FIG. 2A, the voltage of the second offset signal 19a is lowered from the shift signal 1b by the offset value V _off2 . The offset value _{V off1} and _{V off2} may be a different value, may be the same value. In this embodiment, the offset value _{V off1} and _{V off2} are the same value. Further, the offset value _{V off1} and _{V off2} is, when a different value, the threshold _{V th} becomes the two values according to each offset value, the inverting input terminal of the comparator 25, the non-inverting input terminal of the comparator 26 To enter each.

The first offset signal 16a is input to the non-inverting input terminal of the operational amplifier 22, for example, as shown in FIG. The operational amplifier 22 calculates, for example, a difference ΔV ₁ as a first difference between the first offset signal 16a and the shift signal 1b input to the inverting input terminal, and outputs the difference ΔV ₁ as the first difference signal 22a. When the main magnetic sensor 10 and the first magnetic sensor 11 are normal, the difference ΔV ₁ is equal to the offset value V _off1 .

The second offset signal 19a is input to the inverting input terminal of the operational amplifier 23, for example, as shown in FIG. The operational amplifier 23 calculates, for example, a difference ΔV ₂ as a second difference between the shift signal 1b input to the non-inverting input terminal and the second offset signal 19a, and outputs the difference ΔV ₂ as the second difference signal 23a. When the main magnetic sensor 10 and the second magnetic sensor 12 are normal, the difference ΔV ₂ becomes equal to the offset value V _off2 .

Here, the shift signal 1b is a signal obtained by adjusting the shift-side linear output signal 10a with the voltage _Vref . When each magnetic sensor is normal, the shift signal 1b and the first and second offset signals 16a and 19a are difference is a value different from the offset value _{V off1} and _{V off2.} Therefore, in the present embodiment, the voltage _{V ref,} the offset value _{V off1} and _{V off2,} it is assumed that the value does not affect the determination of the failure.

  The failure determination unit 24 of the first magnetic sensor IC1 includes a comparator 25 as a first comparator, a comparator 26 as a second comparator, and an OR circuit 27.

The first difference signal 22 a is input from the non-inverting input terminal of the comparator 25, is a midpoint potential of the resistors 28 and 29, and is compared with the threshold value V _th applied to the inverting input terminal of the comparator 25. . The comparator 25 outputs the comparison result to the OR circuit 27 as the first output signal 25a.

For example, the comparator 25 is configured to output Lo when the difference ΔV ₁ based on the first difference signal 22a is smaller than the threshold value V _th and output Hi when the difference ΔV ₁ is larger.

The second difference signal 23 a is input from the inverting input terminal of the comparator 26, is a midpoint potential of the resistors 28 and 29, and is compared with the threshold value V _th applied to the non-inverting input terminal of the comparator 26. Is done. The comparator 26 outputs the comparison result to the OR circuit 27 as the second output signal 26a.

Comparator 26, for example, when the difference [Delta] V ₂ based on the second differential signal 23a is smaller than the threshold value V _th outputs a Lo, is greater is configured to output a Hi.

The OR circuit 27 is a logical sum circuit in which _Vcc is applied to one end and the other end is grounded. When the input first and second output signals 25a and 26a are other than (Lo, Lo), the OR circuit 27 is connected to the main magnetic sensor 10, the first sub magnetic sensor 11, or the second sub magnetic sensor. It is configured to output a diagnosis signal 1c indicating 12 failures.

  The shift device 5 is connected to a vehicle ECU (Electronic Control Unit) 6 as shown in FIG.

  The vehicle ECU 6 determines the operation position of the shift lever 51 based on the select signals 1a, 3a and the shift signals 1b, 3b output from the first and second magnetic sensors IC1, 3 of the shift device 5, for example. A shift signal 60 based on the operated position is output to the drive unit 7.

  For example, when the diagnosis signal 1c from the first magnetic sensor IC1 or the diagnosis signal 3c from the second magnetic sensor IC3 is input, the vehicle ECU 6 notifies the vehicle occupant of the failure of the shift device 5. The notification signal 61 is output to the notification unit 8. Note that the vehicle ECU 6 switches the drive unit 7 based on the output of a magnetic sensor IC that is different from the magnetic sensor IC that has output the diagnosis signal, for example, when one of the diagnosis signal 1c and the diagnosis signal 3c is input. It may be configured as follows.

  For example, the drive unit 7 changes the gear ratios of a plurality of gears that transmit the rotation of the engine based on the shift signal 60 output from the vehicle ECU 6.

  The notification unit 8 notifies the occupant of a failure of the shift device 5 by, for example, lighting of a lamp or sound. The failure notification method is not limited to the above.

(Operation)
FIG. 3 is a flowchart relating to the operation of the first magnetic sensor IC according to the first embodiment of the invention. Below, operation | movement of 1st magnetic sensor IC1 is demonstrated according to the flowchart of FIG. Note that the shift lever 51 of the shift device 5 is operated to the operation position 44 (N) while the vehicle is stopped.

When the electrical system of the vehicle in the on state, the voltage V _cc is applied to the first and second magnetic sensors IC1,3 from the power supply of the vehicle. The main magnetic sensor 10 of the first magnetic sensor IC1 outputs a shift-side linear output signal 10a to the non-inverting input terminal of the operational amplifier 13. The first sub magnetic sensor 11 outputs a shift-side linear output signal 11 a to the non-inverting input terminal of the operational amplifier 16. The second sub magnetic sensor 12 outputs a shift side linear output signal 12 a to the non-inverting input terminal of the operational amplifier 19. The first and second magnetic sensors IC1, 3 output select signals 1a, 3a to the vehicle ECU 6.

The operational amplifier 13 adjusts the shift-side linear output signal 10a based on the voltage V _ref applied to the inverting input terminal, and outputs it as the shift signal 1b.

The operational amplifier 16 offsets the shift-side linear output signal 11a based on the offset value V _off1 applied to the inverting input terminal, and outputs a first offset signal 16a.

The operational amplifier 19 offsets the shift-side linear output signal 12a based on the offset value V _off2 applied to the inverting input terminal, and outputs a second offset signal 19a.

The operational amplifier 22 calculates a difference ΔV ₁ between the shift signal 1b output from the operational amplifier 13 input to the inverting input terminal and the first offset signal 16a output from the operational amplifier 16 input to the non-inverting input terminal. 1 as a differential signal 22a. The operational amplifier 23 calculates a difference ΔV ₂ between the shift signal 1b output from the operational amplifier 13 input to the non-inverting input terminal and the second offset signal 19a output from the operational amplifier 19 input to the inverting input terminal. The second difference signal 23a is output (S1). Here, when a failure has not occurred, the difference [Delta] V ₁ is regarded as the offset value _{V off1,} difference [Delta] V ₂ can be regarded as the offset value _{V off2.}

Next, the comparator 25 of the failure determination unit 24 compares the first difference signal 22a input to the non-inverting input terminal with the threshold value _Vth and outputs the first output signal 25a. The threshold value _Vth input to the inverting input terminal is compared with the second difference signal 23a input to the inverting input terminal, and the second output signal 26a is output. Here, the threshold value _{V th,} so the same value as the offset value _{V off1} and offset values _{V off2,} when a failure has not occurred, the result of comparison by the comparator 25 becomes (Lo, Lo).

OR circuit 27, first and second output signals 25a, _{V off1} based on 26a> [Delta] V ₁ or _{V off2>} When [Delta] V ₂ holds (S2; Yes), the main magnetic sensor 10, the first and second It is determined that the sub magnetic sensors 11 and 12 are normal (S3). When normal, the first magnetic sensor IC1 continues to operate from step 1 until the vehicle power is turned off.

Further, OR circuit 27, first and second output signals 25a, _{V off1} based on 26a> [Delta] V ₁ or _{V off2>} When [Delta] V ₂ is not satisfied (S2; No), the main magnetic sensor 10, the first and It is determined that a failure has occurred in either of the second sub magnetic sensors 11 and 12, and a diagnosis signal 1c is output (S4).

  The vehicle ECU 6 outputs a notification signal 61 to the notification unit 8 based on the output diagnosis signal 1 c, and the notification unit 8 notifies the failure of the shift device 5 based on the notification signal 61.

(effect)
According to the first magnetic sensor IC1 according to the present embodiment, it is possible to determine the presence or absence of a failure without requiring a determination unit configured by an ECU or the like. In addition, according to the first magnetic sensor IC1, since a determination unit configured by an ECU or the like is not required, a failure self-detection can be performed at a low cost.

  According to the first magnetic sensor IC 1 according to the present embodiment, the main magnetic sensor 10 and the first and second sub magnetic sensors 11 and 12 are packaged together. 10 and the output errors of the first and second sub magnetic sensors 11 and 12 can be suppressed, and the failure detection accuracy is high.

  According to the first magnetic sensor IC1 according to the present embodiment, the presence or absence of a failure is determined by comparing the shift signal 1b with the first and second offset signals 16a and 19a. Even when a failure that continues to output a signal occurs, the failure can be accurately detected.

[Second Embodiment]
The second embodiment is different from the first embodiment in that two offset signals offset from one sub magnetic sensor are generated.

  FIG. 4 is a circuit diagram of a magnetic sensor IC according to the second embodiment of the present invention. In the following embodiments, portions having the same functions and configurations as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 4, for example, the magnetic sensor IC 9 according to this embodiment includes a main magnetic sensor 90, a sub magnetic sensor 91, an operational amplifier 92, an operational amplifier 93, a first offset unit 94, and a second offset. The offset unit 95 and the failure determination unit 96 are roughly configured.

  The main magnetic sensor 90 has, for example, the same configuration and function as the main magnetic sensor 10 in the first embodiment. For example, the main magnetic sensor 90 outputs a shift-side linear output signal 90 a according to a change in the magnetic field due to the movement of the magnet 50.

The shift-side linear output signal 90a is input to the non-inverting input terminal of the operational amplifier 92, for example, as shown in FIG. The shift-side linear output signal 90a is, for example, the midpoint potential of the resistor 100 and the resistor 101, is adjusted by the voltage V _ref applied to the inverting input terminal of the operational amplifier 92, and is output from the magnetic sensor IC9 as the shift signal 1b. .

  The sub magnetic sensor 91 has the same configuration and function as, for example, the first or second sub magnetic sensor 11 or 12 in the first embodiment. For example, the sub magnetic sensor 91 outputs a shift-side linear output signal 91a that is the same as the shift-side linear output signal 90a output from the main magnetic sensor 90 in accordance with a change in the magnetic field due to the movement of the magnet 50.

The shift side linear output signal 91a is input to the non-inverting input terminal of the operational amplifier 93, for example, as shown in FIG. The shift-side linear output signal 91a is adjusted by, for example, the voltage V _ref applied to the inverting input terminal of the operational amplifier 93, and the first and second offset units 94 and 95 serve as the adjustment signal 93a that is the same signal as the shift signal 1b. Is output.

For example, the first offset unit 94 is _configured to offset the adjustment signal 93a so that the output voltage is higher than the adjustment signal 93a by the offset value V _off1 and output the first offset signal 94a to the failure determination unit 96. ing.

For example, the second offset unit 95 is configured to offset the adjustment signal 93a so that the output voltage is lower than the adjustment signal 93a by the offset value V _{off2 and} to output the second offset signal 95a to the failure determination unit 96. ing.

  The failure determination unit 96 is schematically configured to include, for example, a comparator 97, a comparator 98, and an OR circuit 99.

  In the comparator 97, for example, the shift signal 1b output from the operational amplifier 92 is input to the non-inverting input terminal, and the first offset signal 94a output from the first offset unit 94 is input to the inverting input terminal. For example, the comparator 97 compares the shift signal 1 b with the first offset signal 94 a and outputs the first output signal 97 a to the OR circuit 99. For example, the comparator 97 is configured to output Lo when the first offset signal 94a is greater than the shift signal 1b, and output Hi when the first offset signal 94a is smaller.

  In the comparator 98, for example, the second offset signal 95a output from the second offset unit 95 is input to the non-inverting input terminal, and the shift signal 1b output from the operational amplifier 92 is input to the inverting input terminal. For example, the comparator 98 compares the second offset signal 95 a with the shift signal 1 b and outputs the second output signal 98 a to the OR circuit 99. For example, the comparator 98 is configured to output Lo when the shift signal 1b is larger than the second offset signal 95a, and output Hi when it is smaller.

The OR circuit 99 is a logical sum circuit in which _Vcc is applied to one end and the other end is grounded. The OR circuit 99 outputs a diagnosis signal 1c indicating a failure of the main magnetic sensor 90 or the sub magnetic sensor 91 when the input first and second output signals 97a and 98a are other than the combination of (Lo, Lo). It is configured as follows.

(Operation)
FIG. 5 is a flowchart relating to the operation of the magnetic sensor IC according to the second embodiment of the present invention. Below, operation | movement of magnetic sensor IC9 is demonstrated according to the flowchart of FIG. Note that the shift lever 51 of the shift device 5 is operated to the operation position 44 (N) while the vehicle is stopped.

When the electric system of the vehicle is turned on, the voltage _Vcc is applied to the magnetic sensor IC9 from the power source of the vehicle. The main magnetic sensor 90 of the magnetic sensor IC 9 outputs a shift-side linear output signal 90 a to the non-inverting input terminal of the operational amplifier 92.

  The sub magnetic sensor 91 outputs a shift-side linear output signal 91 a to the non-inverting input terminal of the operational amplifier 93. Further, the magnetic sensor IC9 outputs a select signal 1a to the vehicle ECU 6.

The operational amplifier 92 adjusts the shift-side linear output signal 90a based on the voltage V _ref applied to the inverting input terminal, and outputs it as the shift signal 1b.

The operational amplifier 93 adjusts the shift-side linear output signal 91a based on the voltage V _ref applied to the inverting input terminal, and outputs an adjustment signal 93a that is the same signal as the shift signal 1b.

The first offset unit 94 generates the first offset signal 94a by offsetting the input adjustment signal 93a based on the offset value _Voff1 , and outputs the first offset signal 94a (S10).

The second offset unit 95 generates the second offset signal 95a by offsetting the input adjustment signal 93a based on the offset value _Voff2 and outputs it (S10).

  The comparator 97 of the failure determination unit 24 compares the shift signal 1b input to the non-inverting input terminal with the first offset signal 94a and outputs the first output signal 25a, and the comparator 98 receives the non-inverting input terminal. The input second offset signal 95a and the shift signal 1b input to the inverting input terminal are compared to output a second output signal 98a.

  When the second offset signal 95a <shift signal 1b <first offset signal 94a holds based on the first and second output signals 97a and 98a (S11; Yes), the OR circuit 99 It is determined that the sub magnetic sensor 91 is normal (S12).

  When the second offset signal 95a <shift signal 1b <first offset signal 94a does not hold based on the first and second output signals 97a and 98a (S11; No), the OR circuit 99 It is determined that a failure has occurred in the sensor 90 or the sub magnetic sensor 91, and a diagnosis signal 1c is output (S13).

  The vehicle ECU 6 outputs a notification signal 61 to the notification unit 8 based on the output diagnosis signal 1 c, and the notification unit 8 notifies the failure of the shift device 5 based on the notification signal 61.

The magnetic sensor IC9, for example, first and second offset signals 94a offset, includes a calculation unit for calculating a difference between 95a and the shift signal 1b, calculated difference and the offset value _{V off1} and _{V off2} In comparison, at least one failure of the main magnetic sensor 90 and the sub magnetic sensor 91 may be determined.

(effect)
According to the magnetic sensor IC 9 according to the present embodiment, the failure self-detection is performed at a low cost by using fewer magnetic sensors than the first and second magnetic sensor ICs 1 and 3 according to the first embodiment. be able to. Further, according to the magnetic sensor IC9, the failure self-detection can be performed with a smaller configuration.

  The present invention is not limited to the above-described embodiments, and various modifications and combinations can be made without departing from or changing the technical idea of the present invention.

  For example, in the above embodiment, the offset unit, the calculation unit, and the failure determination unit are configured by electronic circuits. However, the present invention is not limited to this, and a part or the whole is replaced by software and executed by a computer. Also good.

DESCRIPTION OF SYMBOLS 1 ... 1st magnetic sensor IC, 1a ... select signal, 1b ... shift signal, 1c ... diagnostic signal, 3 ... 2nd magnetic sensor IC, 3a ... select signal, 3b ... shift signal, 3c ... diagnostic signal, 4 ... Shift pattern, 5 ... shift device, 6 ... vehicle ECU, 7 ... drive unit, 8 ... notification unit, 9 ... magnetic sensor IC, 10 ... main magnetic sensor, 10a ... shift side linear output signal, 11 ... first sub-magnetism Sensor, 11a: Shift side linear output signal, 12: Second sub magnetic sensor, 12a: Shift side linear output signal, 14, 15, 17, 18, 20, 21, 28, 29 ... Resistor, 13, 16, 19 , 22, 23, operational amplifier, 16a, first offset signal, 19a, second offset signal, 22a, first differential signal, 23a, second differential signal, 24, failure determination unit, 25 26 ... Comparator, 25a ... first output signal, 26a ... second output signal, 27 ... OR circuit, 40-45 ... operating position, 50 ... magnet, 51 ... shift lever, 52 ... substrate, 60 ... shift signal, 61 ... Notification signal, 90 ... Main magnetic sensor, 90a ... Shift side linear output signal, 91 ... Sub magnetic sensor, 91a ... Shift side linear output signal, 92, 93 ... Operational amplifier, 93a ... Adjustment signal, 94 ... First offset Part 94a ... first offset signal 95 ... second offset part 95a ... second offset signal 96 ... failure determination part 97, 98 ... comparator 97a ... first output signal 98a ... second Output signal, 99 ... OR circuit, 100, 101 ... resistor

Claims (4)

A first magnetic sensor that outputs a first linear output signal in response to a change in the magnetic field;
Second and third magnetic sensors that output second and third linear output signals that are substantially the same output as the first linear output signal in response to a change in the magnetic field;
In said second linear output signal and zero by calculating the difference between the first offset value without generating the first offset signal, and the second offset value is not a third linear output signal with zero An offset unit for calculating a difference and generating a second offset signal;
A calculating unit that calculates a first difference between the first offset signal and the first linear output signal, and calculates a second difference between the first linear output signal and the second offset signal; ,
When the calculated first difference is greater than the first offset value, it is determined that at least one of the first and second magnetic sensors has failed, and the calculated second difference is the first difference. A failure determination unit that determines that at least one of the first and third magnetic sensors has failed when the offset value is greater than 2.
Magnetic sensor device with The calculation unit includes a first operational amplifier that calculates the first difference and a second operational amplifier that calculates the second difference,
The failure determination unit inputs the first difference to a non-inverting input terminal, compares the threshold value to an inverting input terminal, compares the first difference, and outputs a first output signal; and the second difference Is input to the inverting input terminal, the threshold value is input to the non-inverting input terminal, the second comparator outputs the second output signal, and the first and second output signals are used for the first comparator. 2. An OR circuit that outputs a diagnostic signal indicating a failure of any one of the third to third magnetic sensors , wherein the first offset value, the second offset value, and the threshold value are equal. The described magnetic sensor device. A first magnetic sensor that outputs a first linear output signal in response to a change in the magnetic field;
A second magnetic sensor that outputs a second linear output signal that is substantially the same output as the first linear output signal in response to a change in the magnetic field;
A difference between the second linear output signal and a non-zero first offset value is calculated to generate a first offset signal, and the second linear output signal and the non-zero second offset value are An offset unit for calculating a difference and generating a second offset signal;
When the first linear output signal is larger than the first offset signal, or when the first linear output signal is smaller than the second offset signal, the first or second magnetic sensor is A failure determination unit that determines that a failure has occurred;
Magnetic sensor device with   The failure determination unit inputs the first linear output signal to a non-inverting input terminal, compares the first offset signal to an inverting input terminal, compares the first linear output signal, and outputs a first output signal; A second comparator for inputting the first linear output signal to an inverting input terminal, comparing the second offset signal to a non-inverting input terminal, and outputting the second output signal; and the first and second 4. The magnetic sensor device according to claim 3, further comprising an OR circuit that outputs a diagnosis signal indicating a failure of the first or second magnetic sensor based on the output signal.

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