Brake pedal device and brake system

Abstract

A brake pedal device (10) comprises: a housing (70) fixed to a vehicle; a brake pedal (60) provided so as to be swingable about a prescribed axis (CL) with respect to the housing (70); and at least three sensors (40-42) that output a signal corresponding to an operation amount of the brake pedal (60). The at least three sensors include at least one magnetic sensor (40) and at least two inductive sensors (41, 42). The at least two inductive sensors (41, 42) are disposed separate from each other such that a detection coil of one inductive sensor does not detect the movement of a target metal of the other inductive sensor except for the target metal in the one inductive sensor.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Patent Application No. 2021-142749 filed on September 1, 2021, the contents of which are incorporated herein by reference. [Technical field]

[0002] The present disclosure relates to a brake pedal device and a brake system. [Background technology]

[0003] Conventionally, a brake-by-wire system has been known in which an electronic control unit detects the amount of brake pedal operation based on an output signal from a pedal sensor that outputs a signal corresponding to the amount of brake pedal operation by a driver, and controls the operation of a brake circuit to brake the vehicle. In the following description, the electronic control unit is sometimes referred to as an "ECU," the amount of brake pedal operation is sometimes referred to as a "pedal operation amount," and the brake-by-wire system is sometimes referred to as a "brake system." ECU is an abbreviation for Electronic Control Unit. The brake system described in Patent Document 1 employs an electric brake as an example of a brake circuit. The electric brake includes an electric motor that is driven by a current supplied from a motor driver included in the ECU, and a linear motion mechanism that converts the torque output by the electric motor into linear motion to press a friction member against the brake rotor of each wheel.

[0004] The ECU included in the brake system described in Patent Document 1 detects the pedal operation amount based on the output signal of the pedal sensor and converts it into a target value of the pressing force of the linear motion mechanism of the electric brake. The ECU is configured to compare the output signal of the pressing force sensor that detects the pressing force of the linear motion mechanism with the target value of the pressing force of the linear motion mechanism, and to perform feedback control of the current value supplied from the motor driver to the electric motor.

[0005] This brake system is provided with a current sensor that detects the value of a current supplied from an ECU to the electric motor, and an angle sensor that detects a rotation angle of the electric motor. If the pressing force sensor fails, the ECU is configured to control the current supplied from the ECU to the electric motor based on the output signal of the current sensor and the output signal of the angle sensor to drive the electric brake. Furthermore, this ECU is configured to check the accuracy of the drive of the electric brake based on the output signal of the current sensor and the output signal of the angle sensor when the vehicle is stopped. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2018-43674 A Summary of the Invention

[0007] However, the brake system described in Patent Document 1 is built on the premise that a normal signal indicating a correct pedal operation amount is input to the ECU from a pedal sensor (hereinafter, the pedal sensor is simply referred to as the "sensor") provided in the brake pedal device. If an abnormal signal indicating an incorrect pedal operation amount is input from the sensor to the ECU, the ECU may detect the incorrect pedal operation amount based on the abnormal signal and activate the electric brake, resulting in a problem that the vehicle cannot be braked reliably.

[0008] Therefore, in a brake-by-wire system, it is important that the ECU accurately detects the amount of pedal operation by the driver in order to brake the vehicle reliably. In a brake-by-wire system, it is preferable that the ECU detects the amount of pedal operation using output signals from three or more sensors in order to ensure redundancy of the sensor output signals. In this way, even if an abnormal signal is input to the ECU due to a failure of one sensor, the ECU can determine that the signal is normal by taking a majority vote between the signal from the failed sensor and the signals from the remaining two sensors.

[0009] However, even if three or more sensors are provided in the brake pedal device, if multiple sensors fail simultaneously due to the same cause of failure, the ECU may not be able to determine a normal signal by the majority vote described above. Therefore, when ensuring redundancy with three or more sensors, measures are required to prevent multiple sensors from failing simultaneously due to the same cause of failure.

[0010] As a candidate for a sensor for measuring the pedal operation amount, a pressure sensor that directly measures the pedal force applied by the driver to the brake pedal in a contact manner, or various sensors that measure the rocking angle of the brake pedal in a non-contact manner are conceivable. However, using a contact sensor in a brake pedal device that is frequently used when driving a vehicle has problems such as a decrease in detection accuracy due to deterioration of the sensor's detection section, and problems such as the sensor becoming expensive and large in size in order to ensure reliability. Furthermore, a pressure sensor has a problem that detection accuracy decreases if the driver's pedal force is not applied uniformly to the piezoelectric element. Therefore, it is preferable to adopt a non-contact sensor rather than a contact sensor as a sensor for measuring the pedal operation amount.

[0011] Non-contact sensors include, for example, magnetic sensors that utilize the state of magnetism (specifically, Hall sensors, magnetic resistance sensors, etc.), inductive sensors that utilize electromagnetic induction of a coil, photoelectric sensors that utilize the amount of light, etc. Of these, photoelectric sensors have the problem that the amount of light decreases in the presence of dust or oil, resulting in false detection, and are therefore unsuitable for in-vehicle applications such as brake pedal devices.

[0012] Furthermore, the magnetic sensor is a sensor that detects changes in magnetism inside the sensor. Therefore, if a magnetic foreign object approaches the magnetic sensor, there is a risk of false detection. In the vehicle environment in which the brake pedal device is installed, it is difficult to predict to what extent a magnetic foreign object will approach the sensor. Therefore, if all three sensors were magnetic sensors, there is a risk that all three sensors would fall over when a magnetic foreign object approaches. Therefore, it is not possible to use magnetic sensors for all three sensors.

[0013] Even if two of the three sensors are magnetic sensors, if a magnetic foreign object approaches and both magnetic sensors fail at the same time, the ECU will not be able to determine the normal signal by majority vote. Therefore, it is not possible to use magnetic sensors for two of the three sensors.

[0014] An object of the present disclosure is to provide a brake pedal device and a brake system that are capable of accurately detecting a pedal operation amount using three or more sensors.

[0015] According to one aspect of the present disclosure, there is provided a brake pedal device used in a brake system in which an electronic control device detects an operation amount of a brake pedal based on an output signal of a sensor provided in the brake pedal device and controls the driving of a brake circuit, A housing fixed to a vehicle; a brake pedal that is pivotably provided around a predetermined axis relative to the housing and that is depressed by a driver; At least three sensors outputting signals corresponding to the amount of operation of the brake pedal; The at least three sensors include at least one magnetic sensor and at least two inductive sensors; The magnetic sensor has a magnetic circuit portion that operates together with the brake pedal and a magnetic detection portion that detects a change in a magnetic field generated by the magnetic circuit portion. Each of the at least two inductive sensors has a target metal that cooperates with the brake pedal and a detection coil that detects the movement of the target metal; At least two inductive sensors are arranged apart from each other so that their detection coils do not detect movement of the target metal of the other inductive sensors other than the target metal of their own inductive sensor.

[0016] According to this, the brake pedal device is configured to detect the amount of brake pedal operation using multiple non-contact sensors with different detection principles, such as a magnetic sensor and an inductive sensor. Therefore, even if the output signal of one sensor becomes abnormal due to the proximity of a magnetic foreign object or a conductive foreign object, which each sensor is weak against, the output signals of the other sensors can remain normal. Therefore, this brake pedal device ensures redundancy of the sensor output signals, and the electronic control device can accurately detect the amount of pedal operation by taking a majority vote of the output signals of at least three sensors.

[0017] Specifically, the inductive sensor is a sensor that detects the position of a target metal at a predetermined distance from a detection coil by utilizing electromagnetic induction of the coil. Therefore, if a conductive foreign object (i.e., a metallic foreign object) other than the target metal approaches the inductive sensor, there is a risk of false detection. In contrast, according to one aspect of the present disclosure, the at least three sensors include at least two inductive sensors. Therefore, even if a conductive foreign object enters between the detection coil of one of the inductive sensors and the target metal, the output signals of the other inductive sensors can be kept normal. Therefore, this brake pedal device can ensure redundancy of the sensor output signals by preventing simultaneous failure of multiple inductive sensors, and can accurately detect the pedal operation amount in the electronic control device.

[0018] Further, the magnetic sensor is a sensor that detects a change in the magnetic field generated by the magnetic circuit unit by a magnetic detection unit. Therefore, if the brake pedal device is equipped with multiple magnetic sensors, when a magnetic foreign object approaches the multiple magnetic sensors, the multiple magnetic sensors may simultaneously make erroneous detections. In contrast, according to one aspect of the present disclosure, the at least three sensors include at least one magnetic sensor and at least two inductive sensors. Therefore, even if the magnetic sensor fails due to the proximity of a magnetic foreign object, the output signals of the at least two inductive sensors can remain normal. Therefore, this brake pedal device ensures redundancy of the sensor output signals, and the pedal operation amount can be accurately detected in the electronic control device.

[0019] According to another aspect of the present disclosure, there is provided a brake pedal device used in a brake system in which an electronic control device detects an operation amount of a brake pedal based on an output signal of a sensor provided in the brake pedal device and controls driving of a brake circuit, A housing fixed to a vehicle; a brake pedal that is pivotably provided around a predetermined axis relative to the housing and that is depressed by a driver; At least three sensors outputting signals corresponding to the amount of operation of the brake pedal; the at least three sensors include at least three inductive sensors; Each of the at least three inductive sensors has a target metal that cooperates with the brake pedal and a detection coil that detects the movement of the target metal; The at least three inductive sensors are arranged apart from one another so that their detection coils do not detect movement of the target metals of the other inductive sensors other than the target metal of their own inductive sensor.

[0020] According to this, by arranging the multiple inductive sensors at a distance from each other, even if a conductive foreign object enters between the detection coil of one inductive sensor and the target metal, the output signals of at least the other two inductive sensors can be kept normal. In other words, by spacing the multiple inductive sensors apart, it is possible to prevent simultaneous failure of the multiple inductive sensors due to conductive foreign objects. Therefore, this brake pedal device ensures redundancy of the sensor output signals and allows the electronic control device to accurately detect the pedal operation amount.

[0021] According to yet another aspect of the present disclosure, there is provided a brake system for controlling a brake circuit that applies brakes to a vehicle, comprising: a brake pedal device including a housing fixed to a vehicle, a brake pedal pivotably provided with respect to the housing and depressed by a driver, and at least three sensors that output signals corresponding to an amount of operation of the brake pedal; an electronic control device that detects an operation amount of a brake pedal detected based on output signals of at least three sensors and drives and controls a brake circuit; the at least three sensors include at least one magnetic sensor and at least two inductive sensors, or at least three inductive sensors; The multiple inductive sensors are arranged apart from one another so that the detection coil of each inductive sensor does not detect movement of the target metal of the other inductive sensors other than the target metal of the inductive sensor of that sensor.

[0022] As a result, the brake system according to yet another aspect of the present disclosure, like the brake systems according to the one and another aspect of the present disclosure described above, ensures redundancy of the sensor output signal and enables the electronic control device to accurately detect the pedal operation amount.

[0023] The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and specific components described in the embodiments described below. [Brief description of the drawings]

[0024] [Figure 1] 1 is a block diagram showing a schematic configuration of a brake system according to a first embodiment. [Diagram 2] 1 is a perspective view of a brake pedal device included in a brake system according to a first embodiment, as viewed from the right side. [Diagram 3] 1 is a perspective view of a brake pedal device included in a brake system according to a first embodiment, as viewed from the left side. [Figure 4] 1 is a left side view of a brake pedal device provided in a brake system according to a first embodiment. FIG. [Diagram 5] 5 is a cross-sectional view taken along line VV in FIG. 4. [Figure 6] 6 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] 7 is a cross-sectional view taken along line VII-VII in FIG. 6. [Figure 8] FIG. 4 is an explanatory diagram for explaining an example of a method for detecting a pedal operation amount. [Figure 9] 10 is an explanatory diagram for explaining another example of a method for detecting a pedal operation amount. FIG. [Figure 10A] FIG. 10 is an explanatory diagram for explaining still another example of a method for detecting a pedal operation amount. [Figure 10B] FIG. 10 is an explanatory diagram for explaining still another example of a method for detecting a pedal operation amount. [Figure 10C] FIG. 10 is an explanatory diagram for explaining still another example of a method for detecting a pedal operation amount. [Figure 11] FIG. 11 is a block diagram showing a schematic configuration of a brake system according to a second embodiment. [Figure 12] FIG. 6 is a cross-sectional view of a brake pedal device included in a brake system according to a second embodiment. [Figure 13] 13 is a cross-sectional view taken along line XIII-XIII in FIG. 12. [Figure 14] FIG. 11 is a perspective view of a brake pedal device according to a third embodiment, as viewed from the left side. [Figure 15] FIG. 11 is a cross-sectional view of a brake pedal device according to a fourth embodiment. [Figure 16] 16 is a cross-sectional view taken along line XVI-XVI in FIG. 15. [Figure 17] FIG. 13 is a block diagram showing a schematic configuration of a brake system according to a fifth embodiment. [Figure 18] FIG. 13 is a block diagram showing a schematic configuration of a brake system according to a sixth embodiment. [Figure 19] FIG. 13 is a block diagram showing a schematic configuration of a brake system according to a seventh embodiment. [Figure 20] FIG. 13 is a block diagram showing a schematic configuration of a brake system according to an eighth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals, and the description thereof will be omitted.

[0026] (First embodiment) A first embodiment will be described. First, the configuration of the brake system according to the first embodiment will be described. As shown in FIG. 1, the brake system 1 of the first embodiment is a brake-by-wire system including a brake pedal device 10, an electronic control unit 20 (hereinafter referred to as "ECU 20"), a brake circuit 30, and the like. The brake-by-wire system is a system in which the ECU 20 detects the amount of operation of the brake pedal (hereinafter referred to as "pedal operation amount") based on output signals from a plurality of sensors provided in the brake pedal device 10, and drives and controls the brake circuit 30 to brake the wheels.

[0027] The brake pedal device 10 of the first embodiment includes a plurality of sensors that output a signal according to the pedal operation amount, namely, one magnetic sensor 40 and two inductive sensors 41 and 42. In the following description, one of the two inductive sensors 41 and 42 is referred to as the first inductive sensor 41, and the other inductive sensor is referred to as the second inductive sensor 42.

[0028] The magnetic sensor 40 and the ECU 20 are connected by a first signal line 51. The first inductive sensor 41 and the ECU 20 are connected by a second signal line 52. The second inductive sensor 42 and the ECU 20 are connected by a third signal line 53. Therefore, the output signal of the one magnetic sensor 40 and the output signals of the two inductive sensors 41 and 42 are respectively input to the ECU 20. The first to third signal lines 51 to 53 are, for example, configured by a wire harness or a predetermined in-vehicle LAN (Local Area Network). The specific configurations of the brake pedal device 10 and the three sensors will be described later.

[0029] The ECU 20 is composed of a microcomputer including a processor that performs control processing and arithmetic processing, a storage unit such as a ROM and a RAM that stores programs and data, and the like, and peripheral circuits thereof. The storage unit is composed of a non-transient substantial storage medium. The ECU 20 performs various control processing and arithmetic processing based on the programs stored in the storage unit, and controls the operation of each device connected to the output port. Specifically, the ECU 20 detects an accurate pedal operation amount based on the output signals of the above-mentioned three sensors 40 to 42, and controls the driving of the brake circuit 30. A method of detecting the pedal operation amount executed by the ECU 20 will be described later.

[0030] In the first embodiment, for example, electric brakes 31 to 34 are used as the brake circuit 30. The electric brakes 31 to 34 are mechanisms that apply brakes to the respective wheels by driving electric motors in response to commands from the ECU 20 to press brake pads against disc brake rotors.

[0031] Next, the configuration of the brake pedal device 10 and the three sensors 40-42 of the first embodiment will be described with reference to Figs. 2 to 7. In the first embodiment, an organ-type brake pedal device will be described as an example of the brake pedal device 10. In the organ-type brake pedal device, the part of the brake pedal 60 that is pressed by the driver is disposed above the axis CL of the rocking motion in the vertical direction when mounted on the vehicle. The three-dimensional coordinates shown in Figs. 2 to 6 indicate the up-down direction, the front-rear direction, and the left-right direction when the brake pedal device 10 is mounted on the vehicle.

[0032] As shown in FIGS. 2 to 6, the brake pedal device 10 includes a housing 70, a brake pedal 60, two inductive sensors 41, 42, one magnetic sensor 40, and the like.

[0033] 2 to 4, the housing 70 is fixed to a floor or dash panel of a vehicle by bolts or the like via a base plate 71. A shaft member 61 is provided in the housing 70. As shown in FIG. 6, the shaft member 61 is rotatably supported by a bearing 73 provided inside the housing 70. One end of the shaft member 61 protrudes outward from a right side surface 74 of the housing 70.

[0034] 2 to 4, the brake pedal 60 is formed in a plate shape and disposed obliquely with respect to the floor of the vehicle. Specifically, the brake pedal 60 is disposed obliquely so that its upper end is in the front of the vehicle and its lower end is in the rear of the vehicle. An upper portion of the brake pedal 60 is provided with a thick portion 63 as a portion to be stepped on by the driver.

[0035] The brake pedal 60 and the shaft member 61 are connected by a connecting portion 64. The connecting portion 64 is a plate-shaped member and is provided on the outside of a right side surface 74 of the housing 70. A part of the connecting portion 64 is fixed to an end of the shaft member 61 protruding from the right side surface 74 of the housing 70, and a part of the connecting portion 64 on the brake pedal 60 side is fixed to the back surface of the brake pedal 60. With this configuration, the brake pedal 60 is provided so as to be swingable with respect to the housing 70, with the center of the shaft member 61 serving as an axis CL. In this specification, swinging refers to a rotational movement in the forward and reverse directions within a predetermined angle range around a predetermined axis CL.

[0036] Although not shown in the first embodiment, a space is provided inside the housing 70 for arranging a reaction force generating mechanism that generates a reaction force against the pedal force applied to the brake pedal 60 by the driver. The reaction force generating mechanism provided in the space inside the housing 70 can be composed of one or more elastic members or actuators. The brake pedal 60 of this embodiment is configured not to be mechanically connected to the master cylinder that is provided in a conventional general brake circuit. Even in this configuration, the brake pedal device 10 is provided with a reaction force generating mechanism, so that it is possible to obtain a reaction force similar to that obtained when the brake pedal 60 and the master cylinder are mechanically connected (i.e., when a reaction force is obtained by the hydraulic pressure of the master cylinder).

[0037] 2 to 5, the two inductive sensors 41, 42 detect the swing angle or stroke amount of the brake pedal 60 relative to the housing 70. Both the swing angle and stroke amount of the brake pedal 60 are included in the pedal operation amount.

[0038] As shown in FIG. 2 and FIG. 5, the first inductive sensor 41 has a first target metal 411 and a first circuit board 413. The first target metal 411 operates together with the brake pedal 60. A first detection coil 412 and a first transmitting / receiving circuit for detecting the operation of the first target metal 411 are mounted on the first circuit board 413. The first detection coil 412 includes a transmitting coil and a receiving coil. The first transmitting / receiving circuit detects the position of the first target metal 411 by applying an alternating current to the transmitting coil of the first detection coil 412 and utilizing the physical principle of an eddy current generated in the first target metal 411 moving above the coil, based on the change in inductance of the receiving coil.

[0039] As shown in Figs. 3 to 5, the second inductive sensor 42 has a second target metal 421 and a second circuit board 423. The second target metal 421 operates together with the brake pedal 60. A second detection coil 422 and a second transmitting / receiving circuit for detecting the operation of the second target metal 421 are mounted on the second circuit board 423. The second detection coil 422 also includes a transmitting coil and a receiving coil. The second transmitting / receiving circuit applies an alternating current to the transmitting coil of the second detection coil 422, and detects the position of the second target metal 421 by the change in inductance of the receiving coil, utilizing the physical principle of an eddy current generated in the second target metal 421 moving above the coil.

[0040] The first circuit board 413 on which the first detection coil 412 and the like are mounted is provided on a first side surface of the housing 70 facing one side in the axial direction of the axis center CL. In contrast, the second circuit board 423 on which the second detection coil 422 and the like are mounted is provided on a second side surface of the housing 70 facing the other side in the axial direction of the axis center CL. In the first embodiment, the first side surface corresponds to the right side surface 74, and the second side surface corresponds to the left side surface 75. That is, the first detection coil 412 is provided on the right side surface 74, and the second detection coil 422 is provided on the left side surface 75. The axial direction of the axis center CL can also be referred to as the direction in which the axis center CL extends.

[0041] An upper end of the first target metal 411 is fixed to a right side portion of the brake pedal 60. The first target metal 411 extends from the right side portion of the brake pedal 60 toward the vehicle floor. A lower end of the first target metal 411 is disposed at a position facing a first circuit board 413 on which a first detection coil 412 and the like are provided. The first target metal 411 moves parallel to the right side surface 74 in association with the rocking of the brake pedal 60.

[0042] In contrast, an upper end of the second target metal 421 is fixed to a left portion of the brake pedal 60. The second target metal 421 extends from the left portion of the brake pedal 60 toward the floor. A lower end of the second target metal 421 is disposed in a position facing a second circuit board 423 on which the second detection coil 422 and the like are provided. The second target metal 421 moves parallel to the left side surface 75 as the brake pedal 60 rocks.

[0043] In this manner, in the first embodiment, the first detection coil 412 of the first inductive sensor 41 is provided on the right side surface 74, and the second detection coil 422 of the second inductive sensor 42 is provided on the left side surface 75. That is, the first detection coil 412 and the second detection coil 422 are provided on the left and right sides of the housing 70. As a result, the two inductive sensors 41 and 42 do not detect the movement of the target metal of the other inductive sensor except for the target metal of the inductive sensor itself. In addition, even if a conductive foreign object comes close to the first detection coil 412 provided on the right side surface 74 of the housing 70 and the output signal of the first inductive sensor 41 becomes abnormal, the output signal of the second inductive sensor 42 is not affected by the conductive foreign object. Similarly, even if a conductive foreign object comes close to the second detection coil 422 provided on the left side surface 75 of the housing 70 and the output signal of the second inductive sensor 42 becomes abnormal, the output signal of the first inductive sensor 41 will not be affected by the conductive foreign object.

[0044] 6 and 7, one magnetic sensor 40 has a magnetic circuit unit 401 fixed to an end of a shaft member 61 that operates together with the brake pedal 60, and a magnetic detection unit 402 that detects changes in the magnetic field generated by the magnetic circuit unit 401. The magnetic sensor 40 also detects the rocking angle of the brake pedal 60 relative to the housing 70. As described above, the rocking angle of the brake pedal 60 is included in the pedal operation amount.

[0045] Specifically, the magnetic circuit unit 401 is formed in a cylindrical shape by two permanent magnets 401a, 401b and two arc-shaped yokes 401c, 401d, and is provided around the axis CL of the shaft member 61. The magnetic circuit unit 401 forms a closed magnetic circuit. Note that the closed magnetic circuit is a circuit in which the permanent magnets 401a, 401b and the yokes 401c, 401d are in contact with each other, and a loop through which magnetic flux flows is closed.

[0046] The two permanent magnets 401a, 401b are arranged on one side of the axis CL in the radial direction. In the following description, the magnet arranged on one side of the axis CL in the radial direction of the two permanent magnets 401a, 401b is referred to as the first magnet 401a, and the magnet arranged on the other side of the axis CL is referred to as the second magnet 401b. In addition, one of the two yokes 401c, 401d is referred to as the first yoke 401c, and the other yoke is referred to as the second yoke 401d.

[0047] One circumferential end of the first yoke 401c is connected to the N pole of the first magnet 401a, and the other circumferential end is connected to the N pole of the second magnet 401b. One circumferential end of the second yoke 401d is connected to the S pole of the first magnet 401a, and the other circumferential end is connected to the S pole of the second magnet 401b. Therefore, as shown by the dashed arrow M in FIG. 7, a magnetic field is formed in the radially inner region of the magnetic circuit unit 401, in which magnetic flux flies from the first yoke 401c to the second yoke 401d in a direction intersecting the axis CL.

[0048] The magnetic circuit section 401 is insert-molded inside the resin section 403. The resin section 403 is fixed to one end of the shaft member 61 by a bolt 404 or the like. In this state, the center of the magnetic circuit section 401 coincides with the axis CL of the shaft member 61. The magnetic circuit section 401 swings together with the shaft member 61 around the axis CL of the shaft member 61. When the magnetic circuit section 401 swings together with the shaft member 61 around the axis CL, the direction of the magnetic field formed in the radially inner region of the magnetic circuit section 401 changes. The magnetic detection section 402 is provided in the radially inner region of the magnetic circuit section 401.

[0049] The magnetic detection unit 402 is provided integrally with the resin constituting the sensor holding unit 405 by insert molding. The sensor holding unit 405 is fixed to the housing 70. The positioning of the sensor holding unit 405 and the housing 70 is performed by fitting a protrusion 406 provided on the outer periphery of the sensor holding unit 405 into an inner wall surface 407 of an opening provided in the housing 70. In this state, it is possible to prevent misalignment between the magnetic detection unit 402 provided on the sensor holding unit 405 and the axis CL of the shaft member 61.

[0050] The magnetic detection unit 402 is composed of a magnetoresistance element (hereinafter referred to as an "MR element") or a Hall element that outputs a signal according to the magnetic field of the magnetic circuit unit 401. MR is an abbreviation for Magneto Resistive. The MR element is an element whose electrical resistance value changes according to the angle of the magnetic field in the horizontal direction relative to the magnetic sensing surface. The Hall element is an element that outputs a Hall voltage according to the strength of the magnetic field in the vertical direction relative to the magnetic sensing surface.

[0051] When the driver depresses the brake pedal 60, the brake pedal 60, the shaft member 61, and the magnetic circuit unit 401 all swing about the axis CL. The magnetic detection unit 402 outputs a signal corresponding to the swing angle of the magnetic circuit unit 401. The swing angle of the magnetic circuit unit 401 is the same as the swing angle of the brake pedal 60. Therefore, the magnetic sensor 40 outputs a signal corresponding to the swing angle of the brake pedal 60 relative to the housing 70 as the operation amount of the brake pedal 60.

[0052] The output signals of the two inductive sensors 41, 42 and the one magnetic sensor 40 included in the above-mentioned brake pedal device 10 are input to the ECU 20. The ECU 20 detects an accurate pedal operation amount based on the output signals of the above-mentioned three sensors. As a method of detecting the pedal operation amount executed by the ECU 20, several methods described below are possible.

[0053] First, an example of a method for detecting the pedal operation amount will be described with reference to FIG.

[0054] The horizontal axis of FIG. 8 indicates the three sensors, respectively called the first sensor, the second sensor, and the third sensor. The correspondence between the two inductive sensors 41, 42 and the one magnetic sensor 40 and the first to third sensors is not particularly limited, and may be any correspondence. The vertical axis of FIG. 8 indicates the magnitude of the signal input from each sensor to the ECU 20 and converted into a mutually comparable value according to the output characteristic of each sensor inside the ECU 20, which is called the sensor signal. In the following description, the signals converted into mutually comparable values ​​of the output signals of the first to third sensors are called the first sensor signal S1, the second sensor signal S2, and the third sensor signal S3, respectively. FIG. 8 shows an example of the first to third sensor signals S1 to S3 when the brake pedal 60 is at a predetermined swing angle. This also applies to FIG. 9 and FIG. 10A to FIG. 10C, which will be referred to in the following description.

[0055] In one example of a method for detecting the pedal operation amount, the ECU 20 calculates a difference value for every combination of two sensor signals selected from the first to third sensor signals S1 to S3. The difference value is calculated as an absolute value. The ECU 20 then determines, among the calculated difference values, the two sensor signals with the smallest difference value as normal values, and detects the pedal operation amount based on the normal value.

[0056] Specifically, as shown in Fig. 8, the ECU 20 calculates a difference value Δ1 between the first sensor signal S1 and the second sensor signal S2. The ECU 20 also calculates a difference value Δ2 between the first sensor signal S1 and the third sensor signal S3. The ECU 20 calculates a difference value Δ3 between the second sensor signal S2 and the third sensor signal S3. In the example of Fig. 8, Δ3 is the smallest of the three difference values ​​Δ1, Δ2, and Δ3. In this case, the ECU 20 determines that the second sensor signal S2 and the third sensor signal S3 for which the difference value Δ3 has been calculated are normal values, and detects the pedal operation amount based on the second sensor signal S2 and the third sensor signal S3.

[0057] Next, another example of a method for detecting the pedal operation amount will be described with reference to FIG.

[0058] In another example of a method for detecting the pedal operation amount, the ECU 20 determines, as a normal sensor signal, a sensor signal showing an intermediate value among the first to third sensor signals S1 to S3, excluding the sensor signal showing the maximum value and the sensor signal showing the minimum value, and then detects the pedal operation amount based on the normal sensor signal.

[0059] 9, the ECU 20 determines the third sensor signal S3, which indicates an intermediate value among the first to third sensor signals S1 to S3, excluding the first sensor signal S1 indicating the maximum value and the second sensor signal S2 indicating the minimum value, as a normal sensor signal, and then detects the pedal operation amount based on the normal third sensor signal S3.

[0060] As a modification of the other example of the detection method, the following detection method is also available. For example, the ECU 20 may determine that a sensor signal falling within a reference range between an upper limit value obtained by adding a predetermined value to a sensor signal indicating an intermediate value among the first to third sensor signals S1 to S3 and a lower limit value obtained by subtracting a predetermined value from the sensor signal, is also a normal sensor signal. That is, as shown in the example of FIG. 9, the ECU 20 sets a reference range R1 between an upper limit value obtained by adding a predetermined value Th1 to a normal third sensor signal S3 indicating an intermediate value among the first to third sensor signals S1 to S3 and a lower limit value obtained by subtracting a predetermined value Th2 from the normal third sensor signal S3. In the example of FIG. 9, the second sensor signal S2 falls within the reference range R1. In this case, the ECU 20 determines that the second sensor signal S2 falling within the reference range R1 of the third sensor signal S3 is also a normal sensor signal in addition to the third sensor signal S3 indicating an intermediate value, and detects the pedal operation amount based on the normal second sensor signal S2 and third sensor signal S3.

[0061] Next, still another example of the method for detecting the pedal operation amount will be described with reference to FIGS. 10A to 10C.

[0062] In yet another example of the method for detecting the pedal operation amount, the ECU 20 sets a reference range between an upper limit value obtained by adding a predetermined value to a predetermined sensor signal among the first to third sensor signals S1 to S3 and a lower limit value obtained by subtracting a predetermined value from the predetermined sensor signal. Then, the ECU 20 determines whether the other two sensor signals, excluding the predetermined sensor signal, fall within the reference range set for the predetermined sensor signal by majority vote, thereby distinguishing between a sensor signal indicating an abnormal value and a normal sensor signal. Note that in this detection method, the predetermined sensor signal can be arbitrarily set from among the first to third sensor signals S1 to S3. Also, the value added to and the value subtracted from the predetermined sensor signal may be a fixed value, or may be switched according to the traveling speed of the vehicle, etc.

[0063] 10A to 10C, a predetermined sensor signal that can be arbitrarily set among the first to third sensor signals S1 to S3 is set as the first sensor signal S1. The ECU 20 sets a reference range R2 between an upper limit value obtained by adding a predetermined value Th3 to the first sensor signal S1 and a lower limit value obtained by subtracting a predetermined value Th4 from the first sensor signal S1. Then, a majority vote is taken as to whether the second sensor signal S2 and the third sensor signal S3 fall within the reference range R2, and the ECU 20 distinguishes between normal sensor signals and abnormal signals.

[0064] 10A, neither the second sensor signal S2 nor the third sensor signal S3 is within the reference range R2 of the first sensor signal S1. In this case, the ECU 20 determines by majority vote that the first sensor signal S1 is an abnormal signal and that the second sensor signal S2 and the third sensor signal S3 are normal signals. The ECU 20 then detects the pedal operation amount based on the normal second sensor signal S2 and the third sensor signal S3.

[0065] In the example shown in Fig. 10B, the second sensor signal S2 is within the reference range R2 of the first sensor signal S1, but the third sensor signal S3 is not. In this case, the ECU 20 determines by majority vote that the first sensor signal S1 and the second sensor signal S2 are normal signals and the third sensor signal S3 is an abnormal signal. Then, the ECU 20 detects the pedal operation amount based on the normal first sensor signal S1 and second sensor signal S2.

[0066] 10C, both the second sensor signal S2 and the third sensor signal S3 are within the reference range R2 of the first sensor signal S1. In this case, the ECU 20 determines that all of the first to third sensor signals S1 to S3 are normal. Then, the ECU 20 detects the pedal operation amount based on the normal first to third sensor signals S1 to S3.

[0067] The brake pedal device 10 and the brake system 1 of the first embodiment described above provide the following advantages.

[0068] (1) The brake pedal device 10 of the first embodiment includes three sensors that output signals corresponding to the amount of operation of the brake pedal 60. The three sensors include one magnetic sensor 40 and two inductive sensors 41, 42. The two inductive sensors 41, 42 are disposed apart from each other so that their own detection coils do not detect the movement of the target metals of the other inductive sensors except for the target metal of the inductive sensor itself.

[0069] According to this, the brake pedal device 10 is configured to detect the amount of operation of the brake pedal 60 using multiple non-contact sensors with different detection principles, such as a magnetic sensor 40 and an inductive sensor. Therefore, even if the output signal of one sensor becomes abnormal due to the proximity of a magnetic foreign object or a conductive foreign object that each sensor is weak against, the output signals of the other sensors can remain normal. Therefore, this brake pedal device 10 ensures redundancy of the sensor output signals, and the electronic control device 20 can accurately detect the amount of pedal operation by taking a majority vote of the output signals of the three sensors.

[0070] In addition, the two inductive sensors 41, 42 are arranged apart from each other so that their detection coils do not detect the movement of the target metal of the other inductive sensor except for the target metal of the inductive sensor itself. Therefore, even if a conductive foreign object enters between the detection coil and the target metal of one of the inductive sensors, the output signal of the other inductive sensor can be kept normal. Therefore, by preventing simultaneous failure of multiple inductive sensors, this brake pedal device 10 ensures redundancy of the sensor output signal and allows the ECU 20 to accurately detect the pedal operation amount.

[0071] Furthermore, the brake pedal device 10 includes one magnetic sensor 40 and two inductive sensors 41, 42. Therefore, even if the magnetic sensor 40 fails due to the proximity of a magnetic foreign object, the output signals of the two inductive sensors 41, 42 can remain normal. Therefore, the brake pedal device 10 ensures redundancy of the sensor output signals, and the ECU 20 can accurately detect the pedal operation amount.

[0072] (2) In the brake pedal device 10 of the first embodiment, the detection coil 412 of the first inductive sensor 41 is provided on a first side surface of the housing 70, and the detection coil 422 of the second inductive sensor 42 is provided on a second side surface of the housing 70. In this embodiment, the first side surface corresponds to the right side surface 74, and the second side surface corresponds to the left side surface 75. According to this, by disposing the two detection coils 412, 422 of the two inductive sensors 41, 42 on the first side surface and the second side surface of the housing 70, respectively, it is possible to prevent the inductive sensors 41, 42 from being adjacent to each other. Therefore, it is possible to prevent simultaneous failure of the multiple inductive sensors 41, 42 due to conductive foreign objects.

[0073] (3) In the brake system 1 of the first embodiment, the ECU 20 detects the pedal operation amount in the following manner as an example. That is, the ECU 20 calculates difference values ​​for all combinations of two sensor signals selected from the first to third sensor signals S1 to S3. Then, the ECU 20 determines that the two sensor signals with the smallest difference value among the calculated difference values ​​are normal. According to this, even if one of the first to third sensor signals S1 to S3 has an abnormal value, the amount of operation of the brake pedal 60 can be detected from a normal sensor signal without adopting the sensor signal indicating the abnormal value.

[0074] (4) In the brake system 1 of the first embodiment, the ECU 20 detects the pedal operation amount in the following way as another example: Among the first to third sensor signals S1 to S3, a sensor signal showing an intermediate value excluding the sensor signal showing the maximum value and the sensor signal showing the minimum value is determined to be a normal sensor signal. According to this, even if one of the three sensor signals has an abnormal value, the ECU 20 can detect the operation amount of the brake pedal 60 from the normal sensor signal without adopting the sensor signal indicating the abnormal value.

[0075] (5) In the brake system 1 of the first embodiment, the ECU 20 detects the pedal operation amount in the following way as another example. That is, a reference range R2 is set between an upper limit value obtained by adding a predetermined value Th3 to a predetermined sensor signal and a lower limit value obtained by subtracting a predetermined value Th4 from the predetermined sensor signal. Then, the ECU 20 determines whether two sensor signals other than the predetermined sensor signal fall within the reference range R2 set for the predetermined sensor signal by majority vote, thereby distinguishing between a sensor signal indicating an abnormal value and a normal sensor signal. According to this, a reference range R2 is set for a specific sensor signal among the output signals of the three sensors, and a majority vote is taken as to whether the other two sensor signals fall within that reference range R2, making it possible to distinguish between sensor signals that indicate abnormal values ​​and normal sensor signals.

[0076] Second embodiment The second embodiment will be described. The second embodiment is different from the first embodiment in that the configuration of the three sensors included in the brake pedal device 10 is changed, and other aspects are the same as those of the first embodiment, so only the differences from the first embodiment will be described.

[0077] As shown in Fig. 11, the brake pedal device 10 of the second embodiment includes three inductive sensors 41 to 43 as a plurality of sensors that output signals according to the pedal operation amount. In the following description, the three inductive sensors included in the brake pedal device 10 of the second embodiment are referred to as a first inductive sensor 41, a second inductive sensor 42, and a third inductive sensor 43, respectively. In the second embodiment, the output signals of the first to third inductive sensors 41 to 43 are respectively input to the ECU 20. The ECU 20 accurately detects the pedal operation amount based on the output signals of the first to third inductive sensors 41 to 43, and drives and controls the brake circuit 30.

[0078] In the second embodiment, the configurations of the first inductive sensor 41 and the second inductive sensor 42 are the same as those of the first inductive sensor 41 and the second inductive sensor 42 described in the first embodiment with reference to Figs. 2 to 5. That is, as shown in Figs. 2 and 5, a first circuit board 413 on which the first detection coil 412 and the like of the first inductive sensor 41 are mounted is provided on a right side surface 74 of the housing 70. On the other hand, as shown in Figs. 3 to 5, a second circuit board 423 on which the second detection coil 422 and the like of the second inductive sensor 42 are mounted is provided on a left side surface 75 of the housing 70.

[0079] Furthermore, as shown in FIG. 12 and FIG. 13, the third inductive sensor 43 included in the brake pedal device 10 of the second embodiment is provided inside the housing 70. The inside of the housing 70 is an enclosed space 76 that prevents intrusion of foreign matter from the outside. The third inductive sensor 43 has a third target metal 431 that operates together with the shaft member 61, and a third circuit board 433 on which a third detection coil 432 and a third receiving / transmitting circuit are mounted. The third target metal 431 is fixed to an end of the shaft member 61 and moves together with the shaft member 61. Meanwhile, the third circuit board 433 is provided on the inner wall of the housing 70 at a position facing the third target metal 431 in the axial direction of the axis CL. The third receiving / transmitting circuit detects the position of the third target metal 431 by applying an alternating current to the transmitting coil of the third detection coil 432, utilizing the physical principle of an eddy current generated in the third target metal 431 moving over the coil, based on a change in inductance of the receiving coil. The third inductive sensor 43 is disposed in the sealed space 76 inside the housing 70 into which conductive foreign objects cannot enter, thereby preventing erroneous detection due to conductive foreign objects.

[0080] In the second embodiment described above, the three inductive sensors 41 to 43 do not detect the movement of the target metal of the other inductive sensors except the target metal of the inductive sensor itself. The first circuit board 413 of the first inductive sensor 41 is provided on the right side surface 74 of the housing 70, and the second circuit board 423 of the second inductive sensor 42 is provided on the left side surface 75 of the housing 70. The third inductive sensor 43 is provided inside the housing 70. In this way, by arranging the three inductive sensors 41 to 43 at a distance from each other, it is possible to prevent simultaneous failure of the sensors due to conductive foreign matter. Therefore, by preventing simultaneous failure of multiple inductive sensors, the brake pedal device 10 ensures redundancy of the output signals of the sensors and allows the ECU 20 to accurately detect the pedal operation amount.

[0081] Third embodiment A third embodiment will be described below. The third embodiment is a modification of the first and second embodiments, in which the method of installing the inductive sensor in the brake pedal device 10 is changed.

[0082] As shown in FIG. 14, the brake pedal device 10 of the third embodiment includes two inductive sensors 41, 42 on the left side of the housing 70. Two circuit boards 413, 423 on which the detection coils 412, 422 of the two inductive sensors 41, 42 are mounted are arranged side by side in the vehicle longitudinal direction on the left side surface 75 of the housing 70. On the other hand, two target metals 411, 421 of the two inductive sensors 41, 42 are arranged side by side in the vehicle longitudinal direction on the left side portion of the brake pedal 60. The two target metals 411, 421 of the two inductive sensors 41, 42 extend from the left side portion of the brake pedal 60 to the vehicle floor side. The lower ends of the two target metals 411, 421 are arranged in positions facing the circuit boards 413, 423 on which the corresponding detection coils 412, 422 and transmitting / receiving circuits are provided. The two target metals 411 and 421 move parallel to the left side surface 75 as the brake pedal 60 swings.

[0083] The brake pedal device 10 of the third embodiment includes a third inductive sensor 43 in addition to the two inductive sensors 41 and 42 described above. The third inductive sensor 43 may be disposed on a right side surface 74 of the housing 70, for example, as shown in Fig. 2. Alternatively, the third inductive sensor 43 may be disposed inside the housing 70, for example, as shown in Figs. 12 and 13. Alternatively, the third inductive sensor 43 may be disposed side by side in the vehicle front-rear direction on a left side surface 75 of the housing 70 together with the two inductive sensors 41 and 42 shown in Fig. 14.

[0084] In the third embodiment described above, it is also possible to prevent simultaneous failure of the sensors due to conductive foreign objects by arranging the three inductive sensors 41 to 43 at a distance from each other. Therefore, by preventing simultaneous failure of the multiple inductive sensors, this brake pedal device 10 ensures redundancy of the sensor output signals and enables the ECU 20 to accurately detect the pedal operation amount.

[0085] In the configuration of the third embodiment, a magnetic sensor 40 may be provided in place of the third inductive sensor 43.

[0086] (Fourth embodiment) A fourth embodiment will be described. The fourth embodiment is also a modification of the first to third embodiments, and the method of installing the inductive sensor in the brake pedal device 10 is changed.

[0087] As shown in Figures 15 and 16, the brake pedal device 10 of the fourth embodiment also includes three inductive sensors 41-43 as multiple sensors that output signals according to the pedal operation amount. In the following description, the three inductive sensors included in the brake pedal device 10 of the fourth embodiment will be referred to as the first inductive sensor 41, the second inductive sensor 42, and the third inductive sensor 43, respectively. The first to third inductive sensors 41-43 are provided inside a housing 70. The inside of the housing 70 forms an enclosed space 76 that prevents intrusion of foreign matter from the outside.

[0088] The first inductive sensor 41 has a first circuit board 413 on which a first detection coil 412 and a first transmitting / receiving circuit are mounted, and a first target metal 411 provided to face the first circuit board 413. The first circuit board 413 on which the first detection coil 412 and the first transmitting / receiving circuit are mounted is provided on the inner wall of the right side surface 74 of the housing 70. The first target metal 411 is provided to extend from the shaft member 61 toward the front of the vehicle. An end of the first target metal 411 opposite to the shaft member 61 is disposed at a position facing the first circuit board 413 in the axial direction of the axis center CL. The first target metal 411 moves parallel to the first circuit board 413 in accordance with the rocking of the brake pedal 60 and the shaft member 61.

[0089] The second inductive sensor 42 has a second circuit board 423 on which the second detection coil 422 and the second transmitting / receiving circuit are mounted, and a second target metal 421 provided to face the second circuit board 423. The second circuit board 423 on which the second detection coil 422 and the second transmitting / receiving circuit are mounted is provided on the inner wall of the left side surface 75 of the housing 70. The second target metal 421 is provided to extend from the shaft member 61 toward the front of the vehicle. An end of the second target metal 421 on the opposite side to the shaft member 61 is disposed at a position facing the second circuit board 423 in the axial direction of the shaft center CL. The second target metal 421 moves parallel to the second circuit board 423 in accordance with the rocking of the brake pedal 60 and the shaft member 61.

[0090] The third inductive sensor 43 has a third circuit board 433 on which a third detection coil 432 and a third transmitting / receiving circuit are mounted, and a third target metal 431 provided to face the third circuit board 433. The third target metal 431 is fixed to an end of the shaft member 61 and operates together with the shaft member 61. The third circuit board 433 is provided on the inner wall of the housing 70 at a position facing the third target metal 431 in the axial direction of the axis CL.

[0091] In the fourth embodiment described above, all of the first to third inductive sensors 41 to 43 are disposed in the sealed space 76 inside the housing 70 into which conductive foreign matter cannot enter, so that erroneous detection due to conductive foreign matter does not occur. Furthermore, the first to third inductive sensors 41 to 43 are disposed at a distance from each other inside the housing 70. Therefore, even if a conductive foreign matter enters the housing 70, it is possible to prevent simultaneous failure of the first to third inductive sensors 41 to 43 due to the conductive foreign matter. Therefore, by preventing simultaneous failure of the multiple inductive sensors 41 to 43, the brake pedal device 10 ensures redundancy of the sensor output signals, and the ECU 20 can accurately detect the pedal operation amount.

[0092] In the configuration of the fourth embodiment, a magnetic sensor 40 may be provided in place of any one of the first to third inductive sensors 41 to 43.

[0093] (Fifth to Seventh Embodiments) In the fifth to seventh embodiments, the brake system 1 is modified from the first to fourth embodiments. Note that, in the fifth to seventh embodiments, the brake pedal device 10 is described as including one magnetic sensor 40 and two inductive sensors 41, 42, but is not limited thereto. In the fifth to seventh embodiments, the brake pedal device 10 may also include, for example, three inductive sensors 41 to 43.

[0094] Fifth embodiment As shown in Fig. 17, the brake system 1 of the fifth embodiment includes a first ECU 21 and a second ECU 22. The magnetic sensor 40 and the first ECU 21 are connected by a first signal line 51. The first inductive sensor 41 and the first ECU 21 are connected by a second signal line 52. The second inductive sensor 42 and the second ECU 22 are connected by a third signal line 53. Thus, the output signal of the magnetic sensor 40 and the output signal of the first inductive sensor 41 are input to the first ECU 21. On the other hand, the output signal of the second inductive sensor 42 is input to the second ECU 22.

[0095] The first ECU 21 and the second ECU 22 are connected through an in-vehicle LAN using, for example, CAN (Controller Area Network) communication as a signal transmission unit 55, so that two-way communication can be performed. Therefore, the output signals of the magnetic sensor 40 and the first inductive sensor 41 input to the first ECU 21 are transmitted to the second ECU 22 via the signal transmission unit 55. In addition, the output signal of the second inductive sensor 42 input to the second ECU 22 is transmitted to the first ECU 21 via the signal transmission unit 55. Therefore, the first ECU 21 and the second ECU 22 can accurately detect the pedal operation amount based on the output signals of the above-mentioned three sensors 40 to 42, and can drive and control the brake circuit 30.

[0096] The brake system 1 of the fifth embodiment described above is configured such that an output signal from at least one of the multiple sensors 40-42 is directly input to each of the first ECU 21 and the second ECU 22 via a signal line. Therefore, even if one of the first ECU 21 and the second ECU 22 fails, the brake system 1 can operate the brake circuit 30 using the other ECU. Therefore, the brake system 1 can ensure redundancy of the sensor output signals as well as redundancy of the ECUs.

[0097] Similarly to the brake system 1 described in the first embodiment, etc., the brake system 1 of the fifth embodiment also includes three sensors 40 to 42. Therefore, the brake system 1 of the fifth embodiment also ensures redundancy of the output signals of the sensors 40 to 42, and enables the ECU 20 to accurately detect the pedal operation amount.

[0098] Sixth embodiment As shown in Fig. 18, the brake system 1 of the sixth embodiment also includes a first ECU 21 and a second ECU 22. The magnetic sensor 40 and the first ECU 21 are connected by a first signal line 51. The first inductive sensor 41 and the second ECU 22 are connected by a second signal line 52, and the second inductive sensor 42 and the second ECU 22 are connected by a third signal line 53. Thus, the output signal of the magnetic sensor 40 is input to the first ECU 21. On the other hand, the output signal of the first inductive sensor 41 and the output signal of the second inductive sensor 42 are input to the second ECU 22.

[0099] The first ECU 21 and the second ECU 22 are connected through an in-vehicle LAN using, for example, CAN communication as a signal transmission unit 55, so that two-way communication can be performed. Therefore, the output signal of the magnetic sensor 40 input to the first ECU 21 is transmitted to the second ECU 22 via the signal transmission unit 55. In addition, the output signals of the first inductive sensor 41 and the second inductive sensor 42 input to the second ECU 22 are transmitted to the first ECU 21 via the signal transmission unit 55. Therefore, the first ECU 21 and the second ECU 22 can accurately detect the pedal operation amount based on the output signals of the above-mentioned three sensors 40 to 42, and can drive and control the brake circuit 30.

[0100] The brake system 1 of the sixth embodiment described above is also configured such that an output signal of at least one of the multiple sensors 40-42 is directly input via a signal line to each of the first ECU 21 and the second ECU 22. Therefore, the brake system 1 of the sixth embodiment can achieve the same effects as the fifth embodiment.

[0101] Seventh embodiment As shown in FIG. 19, the brake system 1 of the seventh embodiment also includes a first ECU 21 and a second ECU 22. In the seventh embodiment, the output signal of the magnetic sensor 40 is divided into a first separation signal and a second separation signal, which are input to the first ECU 21 and the second ECU 22, respectively. Specifically, the magnetic sensor 40 and the first ECU 21 are connected by a first signal line 51. The magnetic sensor 40 and the second ECU 22 are connected by a second signal line 52. As a result, the output signal of the magnetic sensor 40 is divided into a first separation signal and a second separation signal, which are input to the first ECU 21 and the second separation signal are input to the second ECU 22. Note that the first separation signal input to the first ECU 21 and the second separation signal input to the second ECU 22 may be the same value obtained by separating the output signal detected from a pair of a magnetic circuit unit and a magnetic detection unit arranged in one magnetic sensor 40. Alternatively, the first separation signal input to the first ECU 21 and the second separation signal input to the second ECU 22 may be the same two output signals detected from two pairs of magnetic circuit sections and magnetic detection sections arranged within a single magnetic sensor 40.

[0102] The first inductive sensor 41 and the first ECU 21 are connected by a third signal line 53. The second inductive sensor 42 and the second ECU 22 are connected by a fourth signal line 54. Therefore, a first separated signal obtained by separating the output signal of the magnetic sensor 40 and the output signal of the first inductive sensor 41 are input to the first ECU 21. On the other hand, a second separated signal obtained by separating the output signal of the magnetic sensor 40 and the output signal of the second inductive sensor 42 are input to the second ECU 22.

[0103] The first ECU 21 and the second ECU 22 are connected through an in-vehicle LAN using, for example, CAN communication as a signal transmission unit 55, so that bidirectional communication can be performed. Therefore, the first separation signal of the magnetic sensor 40 and the output signal of the first inductive sensor 41 inputted to the first ECU 21 are transmitted to the second ECU 22 via the signal transmission unit 55. In addition, the second separation signal of the magnetic sensor 40 and the output signal of the second inductive sensor 42 inputted to the second ECU 22 are transmitted to the first ECU 21 via the signal transmission unit 55. Therefore, the first ECU 21 and the second ECU 22 can accurately detect the pedal operation amount based on the output signals of the above-mentioned three sensors, and can drive and control the brake circuit 30.

[0104] In the brake system 1 of the seventh embodiment described above, the output signal of the magnetic sensor 40 is divided into a first separation signal and a second separation signal, and the first separation signal is input to the first ECU 21 and the second separation signal is input to the second ECU 22. According to this, the first separation signal input to the first ECU 21 and the second separation signal input to the second ECU 22 have the same value. However, if the first ECU 21 is normal and the second ECU 22 fails, the first ECU 21 may detect the first separation signal as a normal value, and the second ECU 22 may detect the second separation signal as an abnormal value. In this case, the first ECU 21 judges the signals of the three sensors including the first separation signal as normal, and the second ECU 22 judges the second separation signal of the magnetic sensor 40 as abnormal. In such a case, the judgment result of the first ECU 21 and the judgment result of the second ECU 22 are compared, and it is possible for the first ECU 21 to operate the brake circuit 30 on the assumption that an abnormality has occurred in the second ECU 22 or the magnetic sensor 40. Therefore, the brake system 1 of the seventh embodiment can detect an abnormality in the first ECU 21 or the second ECU 22.

[0105] Eighth embodiment An eighth embodiment will be described. In the eighth embodiment, the brake pedal device 10 of the first to seventh embodiments is configured to include a fourth sensor 44. The fourth sensor 44 may be, for example, a magnetic sensor or an inductive sensor. Alternatively, the fourth sensor 44 may be, for example, a force sensor that detects the depression force applied to the brake pedal 60 by the driver, a switch sensor that detects only whether the brake pedal 60 is depressed, or a motion sensor that observes the driver's actions.

[0106] The fourth sensor 44 and the ECU 20 are connected by a fourth signal line 54. Therefore, the output signal of the fourth sensor 44 is input to the ECU 20. The output signal of the magnetic sensor 40 and the output signals of the two inductive sensors 41 and 42 are also input to the ECU 20.

[0107] In the eighth embodiment, the ECU 20 is also configured to obtain the pedal operation amount by comparing the output signals of the three sensors 40 to 42 with the output signal of the fourth sensor 44. In this case, the ECU 20 may determine that, of the output signals of the three sensors 40 to 42, a signal that largely deviates from the output signal of the fourth sensor 44 is an abnormal signal.

[0108] Alternatively, when a switch sensor is used as the fourth sensor 44, the ECU 20 may start detecting the operation amount of the brake pedal 60 by the three sensors 40 to 42 in response to the output signal of the fourth sensor 44. According to this configuration, the detection load of the ECU 20 can be reduced.

[0109] Alternatively, if a motion sensor is used as the fourth sensor 44, the ECU 20 may detect the amount of operation of the brake pedal 60 using the three sensors 40 to 42, and adjust the vehicle braking force applied by the brake circuit 30 in accordance with the output signal of the fourth sensor 44.

[0110] In the eighth embodiment, the brake pedal device 10 is described as including one magnetic sensor 40, two inductive sensors 41 and 42, and the fourth sensor 44, but is not limited thereto. The brake pedal device 10 may include, for example, three inductive sensors 41 to 43 and the fourth sensor 44.

[0111] (Other embodiments) (1) In the above embodiments, an organ-type brake pedal device has been described as an example of the brake pedal device 10, but the present invention is not limited thereto. The brake pedal device 10 may be, for example, a pendant-type brake pedal device. The pendant-type brake pedal device 10 is a device in which a portion of the brake pedal 60 that is pressed by the driver is disposed below the axis CL of the rocking motion in the vertical direction when the brake pedal is mounted on the vehicle.

[0112] (2) In the above embodiments, the electric brakes 31 to 34 have been described as an example of the brake circuit 30 included in the brake system 1, but the present invention is not limited thereto. For example, the brake circuit 30 may be configured to increase the hydraulic pressure of the brake fluid by operating a hydraulic pump or a master cylinder, and to drive wheel cylinders arranged on the respective wheels to operate the brake pads.

[0113] (3) In each of the above embodiments, the inductive sensor is provided on the side of the housing or in an enclosed space within the housing, but this is not limited thereto, and the detection range of the inductive sensor may have a maze structure.

[0114] The present disclosure is not limited to the above-described embodiments, and can be modified as appropriate. Moreover, the above-described embodiments are not unrelated to each other, and can be combined as appropriate, except when the combination is clearly impossible. Moreover, in each of the above-described embodiments, it goes without saying that the elements constituting the embodiments are not necessarily essential, except when they are specifically stated as essential or when they are clearly considered essential in principle. Moreover, in each of the above-described embodiments, when the numbers, values, amounts, ranges, etc. of the components of the embodiments are mentioned, they are not limited to the specific numbers, except when they are specifically stated as essential or when they are clearly limited to a specific number in principle. Moreover, in each of the above-described embodiments, when the shapes, positional relationships, etc. of the components are mentioned, they are not limited to the shapes, positional relationships, etc., except when they are specifically stated or when they are limited to a specific shape, positional relationship, etc. in principle.

[0115] The control unit and the method described in the present disclosure may be implemented by a special-purpose computer provided by configuring a processor and a memory programmed to execute one or more functions embodied in a computer program. Alternatively, the control unit and the method described in the present disclosure may be implemented by a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and the method described in the present disclosure may be implemented by one or more special-purpose computers configured by a combination of a processor and a memory programmed to execute one or more functions and a processor configured with one or more hardware logic circuits. The computer program may also be stored in a computer-readable non-transitory tangible recording medium as instructions executed by the computer.

Claims

1. A brake pedal device used in a brake system (1) in which an electronic control device (20-22) detects an amount of operation of a brake pedal (60) based on an output signal of a sensor (40-42) provided in the brake pedal device (10) and drives and controls a brake circuit (30), A housing (70) fixed to a vehicle; the brake pedal, which is provided so as to be pivotable about a predetermined axis (CL) relative to the housing and which is depressed and operated by a driver; At least three of the sensors output a signal corresponding to an amount of operation of the brake pedal, The at least three sensors include at least one magnetic sensor (40) and at least two inductive sensors (41, 42); The magnetic sensor includes a magnetic circuit unit (401) that operates together with the brake pedal, and a magnetic detection unit (402) that detects a change in a magnetic field generated by the magnetic circuit unit, Each of the at least two inductive sensors has a target metal (411, 421) that moves with the brake pedal and a detection coil (412, 422) that detects the movement of the target metal; A brake pedal device, wherein at least two of the inductive sensors are positioned apart from each other so that the detection coil of each inductive sensor does not detect movement of the target metal of another inductive sensor other than the target metal of the inductive sensor of that sensor.

2. A brake pedal device used in a brake system (1) in which an electronic control device (20-22) detects an amount of operation of a brake pedal (60) based on an output signal of a sensor (41-43) provided in the brake pedal device (10) and controls the driving of a brake circuit (30), A housing (70) fixed to a vehicle; the brake pedal, which is provided so as to be pivotable about a predetermined axis (CL) relative to the housing and which is depressed and operated by a driver; At least three of the sensors output a signal corresponding to an amount of operation of the brake pedal, The at least three sensors include at least three inductive sensors (41-43); Each of the at least three inductive sensors has a target metal (411, 421, 431) that moves with the brake pedal and a detection coil (412, 422, 432) that detects the movement of the target metal; A brake pedal device, wherein at least three of the inductive sensors are positioned apart from one another so that the detection coils of each of the inductive sensors do not detect movement of the target metal of another inductive sensor other than the target metal of the inductive sensor of that sensor.

3. The detection coil of one of the inductive sensors is provided on a first side surface (74) of the housing facing one side in the axial direction of the shaft center, 3. A brake pedal device as described in claim 1 or 2, wherein the detection coil of another of the multiple inductive sensors is provided on a second side (75) of the housing facing the other axial direction of the shaft center.

4. 4. The brake pedal device according to claim 1, wherein the target metal and the detection coil of the inductive sensor are provided in an enclosed space (76) inside the housing to prevent the intrusion of foreign matter.

5. 5. The brake pedal device according to claim 1, wherein the inductive sensor detects a rocking angle of the brake pedal relative to the housing.

6. A brake system (1) for controlling the operation of a brake circuit (30) for braking a vehicle, a brake pedal device (10) including a housing (70) fixed to the vehicle, a brake pedal (60) pivotably provided with respect to the housing and depressed by a driver, and at least three sensors (40 to 43) that output a signal corresponding to an amount of operation of the brake pedal; an electronic control device (20 to 22) that detects an operation amount of the brake pedal detected based on output signals of at least three of the sensors and drives and controls the brake circuit; The at least three sensors include at least one magnetic sensor (40) and at least two inductive sensors (41, 42), or at least three inductive sensors (41-43); Each of the plurality of inductive sensors includes a target metal that moves with the brake pedal and a detection coil that detects the movement of the target metal; A brake system, wherein the multiple inductive sensors are positioned apart from one another so that the detection coil of each inductive sensor does not detect movement of the target metal of another inductive sensor other than the target metal of the inductive sensor of that sensor.

7. The electronic control device includes a first electronic control device (21) and a second electronic control device (22), an output signal of a predetermined one of the at least three sensors is input to the first electronic control device; output signals of the at least three sensors other than a predetermined sensor are input to the second electronic control device; 7. The brake system according to claim 6, wherein the output signal of the sensor is communicated bidirectionally between the first electronic control unit and the second electronic control unit.

8. an output signal of the magnetic sensor is divided into a first separation signal and a second separation signal; 8. The brake system of claim 7, wherein the first isolation signal is input to the first electronic control unit and the second isolation signal is input to the second electronic control unit.

9. The signals input from the three sensors to the electronic control device and converted into mutually comparable values ​​according to the output characteristics of each sensor are called a first sensor signal (S1), a second sensor signal (S2), and a third sensor signal (S3), respectively.

9. The brake system according to claim 6, wherein the electronic control device is configured to compare a difference value (Δ1) between the first sensor signal and the second sensor signal, a difference value (Δ2) between the first sensor signal and the third sensor signal, and a difference value (Δ3) between the second sensor signal and the third sensor signal, and detect the amount of operation of the brake pedal as a normal value, the two sensor signals for which the smallest difference value is calculated.

10. The signals input from the three sensors to the electronic control device and converted into mutually comparable values ​​according to the output characteristics of each sensor are called a first sensor signal (S1), a second sensor signal (S2), and a third sensor signal (S3), respectively.

9. The brake system according to claim 6, wherein the electronic control device is configured to determine, when the three sensor signals are different, that a sensor signal indicating an intermediate value among the three sensor signals, excluding a sensor signal indicating a maximum value and a sensor signal indicating a minimum value, is a normal sensor signal.

11. The signals input from the three sensors to the electronic control device and converted into mutually comparable values ​​according to the output characteristics of each sensor are called a first sensor signal (S1), a second sensor signal (S2), and a third sensor signal (S3), respectively. the electronic control device determines whether or not the other two sensor signals, excluding the predetermined sensor signal, fall within a reference range (R2) between an upper limit value obtained by adding a predetermined value (Th3) to a predetermined sensor signal among the three sensor signals and a lower limit value obtained by subtracting a predetermined value (Th4); If the other two sensor signals fall within the reference range of a given sensor signal, it is determined that all three sensor signals are normal signals; When one of the two sensor signals falls within a reference range of a predetermined sensor signal, it is determined that the one sensor signal falling within the reference range and the predetermined sensor signal are normal signals, and the one sensor signal not falling within the reference range is an abnormal signal; 9. The brake system according to claim 6, wherein when neither of the other two sensor signals falls within a reference range of a predetermined sensor signal, it is determined that the two signals not falling within the reference range are normal signals and that the predetermined sensor signal is an abnormal signal.

12. The brake pedal device includes, in addition to the at least three sensors, a fourth sensor (44) that outputs a signal corresponding to an amount of operation of the brake pedal, 12. The brake system according to claim 6, wherein the electronic control device is configured to determine an operation amount of the brake pedal by comparing output signals of at least three of the sensors with an output signal of the fourth sensor.

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