Brake pedal device and brake system

Abstract

A brake pedal device (10) is provided with: a housing (70) fixed to a vehicle; a brake pedal (60) provided in a manner capable of oscillating about a prescribed axis (CL) with respect to the housing (70); and at least three sensors (40-42) that output signals corresponding to an operation amount of the brake pedal (60), the at least three sensors including at least one magnetic sensor (40) and at least two inductive sensors (41, 42), the at least two inductive sensors (41, 42) being disposed apart from each other in a manner such that a detection coil of each inductive sensor does not detect movement of a target metal of the other inductive sensor in addition to a target metal possessed by the inductive sensor itself.

Description

[0001] Cross-referencing of related applications

[0002] 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

[0003] This disclosure relates to brake pedal devices and braking systems. Background Technology

[0004] Previously, brake-by-wire systems were known whereby the electronic control unit (ECU) detected the amount of brake pedal operation based on the output signal of a pedal sensor that corresponds to the amount of brake pedal operation performed by the driver, and then controlled the brake circuit to brake the vehicle. In the following description, the ECU will sometimes be referred to as an "ECU," the amount of brake pedal operation as a "pedal operation," and the brake-by-wire system as a "brake system." ECU is short for Electronic Control Unit.

[0005] In the braking system described in Patent Document 1, an electric brake is used as an example of the braking circuit. The electric brake includes an electric motor that is driven by current supplied from a motor driver in the ECU, and a linear motion mechanism that converts the torque output by the electric motor into linear motion and pushes the friction components against the brake rotors of each wheel.

[0006] The braking system described in Patent Document 1 includes an ECU that detects the pedal operation amount based on the output signal of a pedal sensor and converts it into a target value of the pushing force of the linear motion mechanism of the electric brake. Furthermore, this ECU is configured to compare the output signal of the pushing force sensor that detects the pushing force of the linear motion mechanism with the target value of the pushing force of the linear motion mechanism, and to perform feedback control on the current value supplied from the motor driver to the electric motor.

[0007] This braking system includes a current sensor and an angle sensor. The current sensor detects the current supplied to the electric motor from the ECU, and the angle sensor detects the rotation angle of the electric motor. The ECU is configured to, in the event of a malfunction in the thrust sensor, control the current supplied to the electric motor from the ECU based on the output signals of the current sensor and the angle sensor, thereby actuating the electric brake. Furthermore, the ECU is configured to, when the vehicle is stationary, verify the accuracy of the electric brake actuation based on the output signals of the current sensor and the angle sensor.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2018-43674 Summary of the Invention

[0011] However, the braking system described in Patent Document 1 is based on the premise that a normal signal indicating the correct pedal operation amount is input from a pedal sensor (hereinafter simply referred to as "sensor") installed in the brake pedal device to the ECU. If an abnormal signal indicating an incorrect pedal operation amount is input to the ECU from the sensor, when the ECU detects the incorrect pedal operation amount based on the abnormal signal and actuates the electric brake, there is a problem that the vehicle can no longer be braked reliably.

[0012] Therefore, in a brake-on-line system, it is crucial for the ECU to accurately detect the amount of pedal operation performed by the driver in order to reliably brake the vehicle. Furthermore, to ensure redundancy of sensor output signals in a brake-on-line system, it is preferable for the ECU to use the output signals of three or more sensors to detect the amount of pedal operation. Thus, even if an abnormal signal is input to the ECU due to the failure of one sensor, the ECU can distinguish a normal signal by taking a majority decision between the signal from the faulty sensor and the signals from the remaining two sensors.

[0013] However, even with three or more sensors in the brake pedal system, if multiple sensors fail simultaneously due to the same cause, the ECU can no longer determine the normal signal through the majority decision method. Therefore, even with three or more sensors ensuring redundancy, countermeasures are needed to prevent multiple sensors from failing simultaneously due to the same cause.

[0014] Furthermore, as candidates for sensors to measure the amount of pedal operation, pressure sensors that directly measure the force applied by the driver to the brake pedal (contact type) or various sensors that measure the swing angle of the brake pedal (non-contact type) are conceivable. However, using contact sensors for brake pedal devices, which are frequently used during vehicle operation, presents problems such as decreased detection accuracy due to deterioration of the sensor's detection section, and the need for expensive and large sensors to ensure reliability. Moreover, there is also the problem that pressure sensors lose accuracy when the driver's pedal force is not uniformly applied to the piezoelectric element. Therefore, non-contact sensors, rather than contact sensors, are preferred for measuring the amount of pedal operation.

[0015] Non-contact sensors include magnetic sensors that utilize magnetic states (specifically, Hall effect sensors, magnetoresistive sensors, etc.), inductive sensors that utilize the electromagnetic induction of coils, and photoelectric sensors that utilize light flux. Among these, photoelectric sensors are not suitable for automotive applications such as brake pedal devices because they suffer from issues such as false detections due to decreased light flux caused by dust or oil.

[0016] Furthermore, magnetic sensors detect changes in magnetic field within the sensor itself. Therefore, if a magnetic object approaches the vicinity of the magnetic sensor, false detections may occur. In the automotive environment where the brake pedal is located, it is difficult to predict the degree of magnetism that a foreign object might approach the sensor. Therefore, if all three sensors are magnetic sensors, all three sensors may fail if a magnetic object approaches. Thus, a solution that uses all three sensors as magnetic sensors is not feasible.

[0017] Furthermore, even when two of the three sensors are magnetic sensors, the ECU cannot distinguish normal signals through majority decision when a magnetic foreign object approaches and both magnetic sensors malfunction simultaneously. Therefore, the scheme of setting two of the three sensors as magnetic sensors is also not feasible.

[0018] The purpose of this disclosure is to provide a brake pedal device and braking system that can accurately detect the amount of pedal operation using three or more sensors.

[0019] According to one technical solution of this disclosure, a brake pedal device is used in a braking system. In this braking system, an electronic control device detects the amount of brake pedal operation based on the output signals of sensors provided by the brake pedal device, and drives and controls the braking circuit. The brake pedal device includes: a housing fixed to a vehicle; a brake pedal configured to swing about a predetermined axis relative to the housing, operated by a driver; and at least three sensors that output signals corresponding to the amount of brake pedal operation. 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 with the brake pedal and a magnetic detection portion that detects changes in the magnetic field generated by the magnetic circuit portion. The at least two inductive sensors each have a target metal that operates with the brake pedal and a detection coil that detects the movement of the target metal. The at least two inductive sensors are arranged apart from each other in such a way that their own detection coils will not detect the movement of the target metal of other inductive sensors besides the target metal of their own inductive sensor.

[0020] Therefore, the brake pedal device uses multiple non-contact sensors with different detection principles, such as magnetic and inductive sensors, to detect the amount of brake pedal operation. Thus, even if the output signal of one sensor becomes abnormal due to the proximity of a magnetic or conductive foreign object that the sensors are not suited for, the output signals of the other sensors remain normal. Therefore, this brake pedal device ensures redundancy in the sensor output signals, allowing the electronic control unit to make a majority decision based on the output signals of the three sensors, thereby accurately detecting the amount of pedal operation.

[0021] Specifically, inductive sensors utilize the electromagnetic induction of a coil to detect the position of a target metal at a predetermined distance from the detection coil. Therefore, if a conductive foreign object (i.e., a metallic foreign object) other than the target metal approaches the vicinity of the inductive sensor, false detection may occur. In contrast, according to one embodiment of this disclosure, at least three sensors include at least two inductive sensors. Therefore, even assuming a conductive foreign object intrudes between the detection coil and the target metal of one inductive sensor, the output signals of the other inductive sensors can remain normal. Thus, by preventing simultaneous failure of multiple inductive sensors, this brake pedal device ensures the redundancy of sensor output signals, enabling accurate detection of pedal operation in the electronic control unit.

[0022] Furthermore, magnetic sensors are sensors that detect changes in the magnetic field generated by a magnetic circuit through a magnetic detection unit. Therefore, assuming the brake pedal device has multiple magnetic sensors, if a magnetic foreign object approaches the vicinity of these sensors, multiple magnetic sensors may simultaneously cause false detections. In contrast, according to a technical solution of this disclosure, at least three sensors include at least one magnetic sensor and at least two inductive sensors. Therefore, even assuming that the magnetic sensors malfunction due to the proximity of a magnetic foreign object, the output signals of at least two inductive sensors can remain normal. Thus, this brake pedal device can ensure the redundancy of the sensor output signals, enabling accurate detection of pedal operation in the electronic control unit.

[0023] Furthermore, according to another technical solution of this disclosure, a brake pedal device is used in a braking system. In this braking system, an electronic control device detects the amount of brake pedal operation based on the output signals of sensors provided by the brake pedal device, and drives and controls the braking circuit. The brake pedal device includes: a housing fixed to a vehicle; a brake pedal configured to swing about a predetermined axis relative to the housing, operated by a driver; and at least three sensors that output signals corresponding to the amount of brake pedal operation. The at least three sensors include at least three inductive sensors. Each of the at least three inductive sensors has a target metal that moves 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 each other in such a way that their own detection coils will not detect the movement of the target metals of other inductive sensors besides the target metal of their own inductive sensors.

[0024] Therefore, by arranging multiple inductive sensors separately, even if a conductive foreign object intrudes between the detection coil and target metal of one inductive sensor, the output signals of at least the other two inductive sensors can remain normal. That is, by separating the multiple inductive sensors by a distance, simultaneous failure of multiple inductive sensors due to conductive foreign objects can be prevented. Thus, this brake pedal device ensures the redundancy of the sensor output signals, enabling accurate detection of pedal operation in the electronic control unit.

[0025] Furthermore, according to another technical solution of this disclosure, a braking system is a braking system that drives and controls the braking circuit for braking a vehicle. This braking system includes: a brake pedal device having a brake pedal fixed to the vehicle housing, configured to swing relative to the housing and operated by the driver, and at least three sensors that output signals corresponding to the amount of brake pedal operation; and an electronic control device that detects the amount of brake pedal operation detected based on the output signals of the at least three sensors and drives and controls the braking circuit. The at least three sensors include at least one magnetic sensor and at least two inductive sensors, or include at least three inductive sensors. The multiple inductive sensors are arranged separately from each other in such a way that their respective detection coils do not detect movement of the target metal of other inductive sensors besides the target metal of their own inductive sensor.

[0026] Therefore, the braking system according to another technical solution of this disclosure is also similar to the braking systems of one and another technical solutions of this disclosure described above, and can ensure the redundancy of the sensor output signal, and can correctly detect the pedal operation amount in the electronic control device.

[0027] Furthermore, the parenthesized labels assigned to each constituent element indicate an example of the correspondence between that constituent element and the specific constituent element described in the embodiments described later. Attached Figure Description

[0028] Figure 1 This is a block diagram showing the general structure of the braking system according to the first embodiment.

[0029] Figure 2 This is a perspective view of the brake pedal device included in the braking system of the first embodiment, viewed from the right side.

[0030] Figure 3 This is a perspective view of the brake pedal device included in the braking system of the first embodiment, viewed from the left side.

[0031] Figure 4 This is a left-side view of the brake pedal device included in the braking system of the first embodiment.

[0032] Figure 5 yes Figure 4 A cross-sectional view of the V-V line.

[0033] Figure 6 yes Figure 4 A sectional view along line VI-VI.

[0034] Figure 7 yes Figure 6 A sectional view of line VII-VII.

[0035] Figure 8 This is an explanatory diagram illustrating an example of a method for detecting pedal operation.

[0036] Figure 9 This is an explanatory diagram illustrating another example of a method for detecting pedal operation.

[0037] Figure 10A These are illustration diagrams illustrating other examples of methods for detecting pedal operation amounts.

[0038] Figure 10B These are illustration diagrams illustrating other examples of methods for detecting pedal operation amounts.

[0039] Figure 10C These are illustration diagrams illustrating other examples of methods for detecting pedal operation amounts.

[0040] Figure 11 This is a block diagram showing the general structure of the braking system according to the second embodiment.

[0041] Figure 12This is a cross-sectional view of the brake pedal device included in the braking system of the second embodiment.

[0042] Figure 13 yes Figure 12 A cross-sectional view of line XIII-XIII.

[0043] Figure 14 This is a perspective view of the brake pedal device of the third embodiment, viewed from the left side.

[0044] Figure 15 This is a cross-sectional view of the brake pedal device according to the fourth embodiment.

[0045] Figure 16 yes Figure 15 A cross-sectional view of the XVI-XVI line.

[0046] Figure 17 This is a block diagram showing the general structure of the braking system according to the fifth embodiment.

[0047] Figure 18 This is a block diagram showing the general structure of the braking system according to the sixth embodiment.

[0048] Figure 19 This is a block diagram showing the general structure of the braking system according to the seventh embodiment.

[0049] Figure 20 This is a block diagram showing the general structure of the braking system according to the eighth embodiment. Detailed Implementation

[0050] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Furthermore, in the following embodiments, identical or equivalent parts will be given the same reference numerals and their descriptions will be omitted.

[0051] (First Embodiment)

[0052] The first embodiment will be described. First, the structure of the braking system according to the first embodiment will be described. Figure 1 As shown, the braking system 1 of the first embodiment is a brake-by-wire system including a brake pedal device 10, an electronic control device 20 (hereinafter referred to as "ECU20"), a brake circuit 30, etc. The brake-by-wire system is a system in which the ECU20 detects the amount of brake pedal operation (hereinafter referred to as "pedal operation amount") based on the output signals of multiple sensors installed on the brake pedal device 10, and drives and controls the brake circuit 30 to brake the wheels.

[0053] The brake pedal device 10 of the first embodiment includes a magnetic sensor 40 and two inductive sensors 41 and 42 as multiple sensors that output signals corresponding to the pedal operation amount. In the following description, one of the two inductive sensors 41 and 42 will be referred to as the first inductive sensor 41, and the other inductive sensor will be referred to as the second inductive sensor 42.

[0054] The magnetic sensor 40 is connected to the ECU 20 via the first signal line 51. The first inductive sensor 41 is connected to the ECU 20 via the second signal line 52. The second inductive sensor 42 is connected to the ECU 20 via the third signal line 53. Therefore, the output signal of one magnetic sensor 40 and the output signals of the two inductive sensors 41 and 42 are respectively input to the ECU 20. Furthermore, the first to third signal lines 51 to 53 are configured, for example, by in-vehicle wiring or a pre-defined in-vehicle LAN (Local Area Network). The specific structure of the brake pedal device 10 and the three sensors will be described later.

[0055] The ECU 20 consists of a microcomputer and its peripheral circuitry. The microcomputer includes a processor for control and computational processing, and storage units such as ROM and RAM for storing programs and data. The storage units are composed of non-transient physical storage media. The ECU 20 performs various control and computational processes based on the programs stored in the storage units, controlling the actions of the devices connected to the output ports. Specifically, the ECU 20 detects the correct pedal operation amount based on the output signals of the three sensors 40-42 mentioned above, and drives and controls the brake circuit 30 accordingly. The method for detecting the pedal operation amount performed by the ECU 20 will be described later.

[0056] In the first embodiment, electric brakes 31 to 34 are used as the braking circuit 30. The electric brakes 31 to 34 are mechanisms that are driven by an electric motor according to instructions from the ECU 20, and push the brake pads against the disc brake disc to brake each wheel.

[0057] Next, refer to Figures 2-7 The structure of the brake pedal device 10 and the three sensors 40-42 in the first embodiment will be described. In the first embodiment, an organ-type brake pedal device will be described as an example of the brake pedal device 10. An organ-type brake pedal device is a structure in which the portion of the brake pedal 60 for the driver to press is positioned above the pivot point CL in the vertical direction when the vehicle is mounted. Furthermore, Figures 2-6 The three-dimensional coordinates recorded in the text represent the up-down, forward-backward, and left-right directions of the brake pedal device 10 when it is mounted in the vehicle.

[0058] like Figures 2-6 As shown, the brake pedal device 10 includes a housing 70, a brake pedal 60, two inductive sensors 41 and 42, and a magnetic sensor 40.

[0059] like Figures 2-4 As shown, the housing 70 is fixed to the vehicle floor or dashboard via bolts or the like via a base plate 71. A shaft component 61 is provided on the housing 70. Figure 6 As shown, the shaft component 61 is rotatably supported by a bearing 73 disposed inside the housing 70. One end of the shaft component 61 protrudes outward from the right side 74 of the housing 70.

[0060] like Figures 2-4 As shown, the brake pedal 60 is formed in the shape of a plate and is arranged at an angle relative to the vehicle floor. Specifically, the brake pedal 60 is arranged at an angle with its upper end facing the front of the vehicle and its lower end facing the rear of the vehicle. A thick-walled portion 63 is provided on the upper side of the brake pedal 60 as a part for the driver to step on.

[0061] The brake pedal 60 and the shaft member 61 are connected by a connecting part 64. The connecting part 64 is a plate-shaped component provided on the outer side of the right side face 74 of the housing 70. A portion of the connecting part 64 is fixed to the end of the shaft member 61 that protrudes from the right side face 74 of the housing 70, and the portion of the connecting part 64 on the brake pedal 60 side is fixed to the back of the brake pedal 60. With this structure, the brake pedal 60 is configured to swing relative to the housing 70 about the center CL of the shaft member 61. In this specification, swinging refers to rotational movement in the positive and negative directions within a specified angle range about a predetermined axis CL.

[0062] Furthermore, in the first embodiment, although the illustration is omitted, a space for arranging a reaction force generating mechanism is provided inside the housing 70. This reaction force generating mechanism generates a reaction force relative to the force applied by the driver to the brake pedal 60. The reaction force generating mechanism provided in the space within the housing 70 can be composed of one or more elastic components or actuators. The brake pedal 60 in this embodiment is not mechanically connected to the master cylinder present in a conventional brake circuit. In this structure, the brake pedal device 10, by providing the reaction force generating mechanism, can obtain the same reaction force as when the brake pedal 60 is mechanically connected to the master cylinder (i.e., when a reaction force generated by the hydraulic pressure of the master cylinder can be obtained).

[0063] like Figures 2-5As shown, two inductive sensors 41 and 42 detect the swing angle or travel of the brake pedal 60 relative to the housing 70. Furthermore, both the swing angle and travel of the brake pedal 60 are included in the pedal operation amount.

[0064] like Figure 2 and Figure 5 As shown, the first inductive sensor 41 includes 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 for detecting the movement of the first target metal 411 and a first transceiver circuit are mounted on the first circuit board 413. The first detection coil 412 includes a transmitting coil and a receiving coil. The first transceiver circuit applies an alternating current to the transmitting coil of the first detection coil 412, and detects the position of the first target metal 411 by utilizing the physical principle of eddy currents generated by the first target metal 411 moving above the coil and based on the change in inductance of the receiving coil.

[0065] like Figures 3-5 As shown, the second inductive sensor 42 includes 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 for detecting the movement of the second target metal 421 and a second transceiver circuit are mounted on the second circuit board 423. The second detection coil 422 also includes a transmitting coil and a receiving coil. The second transceiver 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 utilizing the physical principle of eddy currents generated by the second target metal 421 moving above the coil and based on the change in inductance of the receiving coil.

[0066] A first circuit board 413, on which the first detection coil 412 and the like are mounted, is located on a first side of the housing 70 facing the axial direction of the axis CL. Conversely, a second circuit board 423, on which the second detection coil 422 and the like are mounted, is located on a second side of the housing 70 facing the axial direction of the axis CL. In the first embodiment, the first side corresponds to the right side 74, and the second side corresponds to the left side 75. That is, the first detection coil 412 is located on the right side 74, and the second detection coil 422 is located on the left side 75. Furthermore, the axial direction of the axis CL can also be described as the direction in which the axis CL extends.

[0067] Furthermore, the upper end of the first target metal 411 is fixed to the right side of the brake pedal 60. The first target metal 411 extends from the right side of the brake pedal 60 to the vehicle floor side. The lower end of the first target metal 411 is positioned opposite the first circuit board 413, on which the first detection coil 412 and the like are provided. The first target metal 411 moves parallel to the right side surface 74 as the brake pedal 60 is moved.

[0068] In contrast, the upper end of the second target metal 421 is fixed to the left side of the brake pedal 60. The second target metal 421 extends from the left side of the brake pedal 60 to the floor side. The lower end of the second target metal 421 is positioned opposite the 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 75 as the brake pedal 60 swings.

[0069] Thus, in the first embodiment, the first detection coil 412 of the first inductive sensor 41 is disposed on the right side 74, and the second detection coil 422 of the second inductive sensor 42 is disposed on the left side 75. That is, the first detection coil 412 and the second detection coil 422 are disposed on the left and right sides, separated by the housing 70. Therefore, the two inductive sensors 41 and 42 will not detect movement of the target metal of any inductive sensor other than the target metal of their own inductive sensor. Furthermore, even if a conductive foreign object approaches the first detection coil 412 disposed on the right side 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 will not be affected by the conductive foreign object. Similarly, even if a conductive foreign object approaches the second detection coil 422 disposed on the left side 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.

[0070] Next, as Figure 6 and Figure 7 As shown, a magnetic sensor 40 has a magnetic circuit section 401 and a magnetic detection section 402. The magnetic circuit section 401 is fixed to the end of a shaft member 61 that moves together with the brake pedal 60; the magnetic detection section 402 detects changes in the magnetic field generated in the magnetic circuit section 401. The magnetic sensor 40 detects the swing angle of the brake pedal 60 relative to the housing 70. As described above, the swing angle of the brake pedal 60 is included in the pedal operation amount.

[0071] Specifically, the magnetic circuit section 401 is formed into a cylindrical shape by two permanent magnets 401a and 401b and two arc-shaped magnetic yokes 401c and 401d, and is arranged around the axis CL of the shaft member 61. The magnetic circuit section 401 constitutes a closed magnetic circuit. In addition, a closed magnetic circuit is a loop in which the permanent magnets 401a and 401b contact with the magnetic yokes 401c and 401d to close the flow of magnetic flux.

[0072] Two permanent magnets 401a and 401b are arranged radially on one side and the other side, separated by an axis CL. In the following description, the permanent magnet 401a or 401b arranged radially on one side separated by the axis CL is referred to as the first magnet 401a, and the magnet arranged radially on the other side is referred to as the second magnet 401b. Furthermore, one of the two yokes 401c or 401d is referred to as the first yoke 401c, and the other yoke is referred to as the second yoke 401d.

[0073] One circumferential end of the first magnetic 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 magnetic 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... Figure 7 As indicated by the dashed arrow M, a magnetic field is formed in the region radially inside the magnetic circuit section 401, where magnetic flux flies from the first yoke 401c toward the second yoke 401d in a direction intersecting the axis CL.

[0074] A magnetic circuit portion 401 is inlaid and molded inside a resin portion 403. The resin portion 403 is fixed to one end of a shaft member 61 by bolts 404 or the like. In this state, the center of the magnetic circuit portion 401 coincides with the axis CL of the shaft member 61. Furthermore, the magnetic circuit portion 401 and the shaft member 61 oscillate together around the axis CL of the shaft member 61. When the magnetic circuit portion 401 and the shaft member 61 oscillate together around the axis CL, the orientation of the magnetic field formed in the radially inner region of the magnetic circuit portion 401 changes. A magnetic detection portion 402 is provided in the radially inner region of the magnetic circuit portion 401.

[0075] The magnetic detection unit 402 is integrally formed into the resin constituting the sensor holding unit 405 by insert molding. The sensor holding unit 405 is fixed to the housing 70. Furthermore, the positioning of the sensor holding unit 405 and the housing 70 is achieved by engaging a protrusion 406 provided on the outer periphery of the sensor holding unit 405 with the inner wall surface 407 of the opening provided in the housing 70. In this state, it is possible to prevent the position of the magnetic detection unit 402 provided in the sensor holding unit 405 from shifting from the axis CL of the shaft member 61.

[0076] The magnetic detection unit 402 is composed of a magnetoresistive element (hereinafter referred to as "MR element") or a Hall element that outputs a signal corresponding to the magnetic field of the magnetic circuit unit 401. MR is short for Magneto Resistive. Furthermore, an MR element is a component whose resistance value changes accordingly based on the angle of the magnetic field in the horizontal direction relative to the magnetic sensing surface. A Hall element is a component that outputs a Hall voltage corresponding to the strength of the magnetic field in the vertical direction relative to the magnetic sensing surface.

[0077] When the driver depresses the brake pedal 60, the brake pedal 60, shaft component 61, and magnetic circuit section 401 all swing around the axis CL. The magnetic detection unit 402 outputs a signal corresponding to the swing angle of the magnetic circuit section 401. The swing angle of the magnetic circuit section 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, which serves as the operation amount of the brake pedal 60.

[0078] The output signals of the two inductive sensors 41 and 42 and the output signal of the magnetic sensor 40 of the brake pedal device 10 described above are respectively input to the ECU 20. Based on the output signals of the three sensors, the ECU 20 detects the correct pedal operation amount. Several methods for detecting the pedal operation amount performed by the ECU 20 can be described below.

[0079] First, refer to Figure 8 This illustrates an example of a method for detecting pedal operation.

[0080] Figure 8 The horizontal axis represents the three sensors, referred to as sensor 1, sensor 2, and sensor 3, respectively. Furthermore, the correspondence between the two inductive sensors 41 and 42 and the one magnetic sensor 40 and the first to third sensors is not specifically limited and can be arbitrary. Figure 8 The vertical axis represents the magnitude of the sensor signal, which is obtained by converting the signals input from each sensor to the ECU20 and then, within the ECU20, into comparable values ​​based on the output characteristics of each sensor. Furthermore, in the following explanation, the signals obtained by converting the output signals of the 1st to 3rd sensors into comparable values ​​are referred to as the 1st sensor signal S1, the 2nd sensor signal S2, and the 3rd sensor signal S3, respectively. Figure 8 This diagram shows examples of the signals S1 to S3 from the first to third sensors when the brake pedal 60 is at a specified swing angle. This is also relevant to the descriptions provided later. Figure 9 , Figures 10A to 10C The same applies.

[0081] In one example of a method for detecting pedal operation amount, the ECU 20 calculates the difference for all combinations of two sensor signals selected from the first to third sensor signals S1 to S3. Furthermore, the difference is calculated as an absolute value. The ECU 20 then determines the two sensor signals with the smallest calculated difference as normal values ​​and detects the pedal operation amount based on these normal values.

[0082] Specifically, such as Figure 8 As shown, ECU 20 calculates the difference Δ1 between the first sensor signal S1 and the second sensor signal S2. Furthermore, ECU 20 calculates the difference Δ2 between the first sensor signal S1 and the third sensor signal S3. ECU 20 also calculates the difference Δ3 between the second sensor signal S2 and the third sensor signal S3. Figure 8 In the example, among the three differences Δ1, Δ2, and Δ3, Δ3 is the smallest. In this case, the ECU20 will determine the second sensor signal S2 and the third sensor signal S3, which have been calculated to have this difference Δ3, as normal values, and will use these second sensor signal S2 and the third sensor signal S3 to detect the pedal operation amount.

[0083] Next, refer to Figure 9 Another example of a method for detecting pedal operation is described.

[0084] In another example of the method for detecting pedal operation amount, the ECU 20 determines the sensor signals representing intermediate values ​​(excluding the sensor signals representing the maximum and minimum values) from the first to third sensor signals S1 to S3 as normal sensor signals. Furthermore, the ECU 20 detects the pedal operation amount based on these normal sensor signals.

[0085] Specifically, such as Figure 9 As shown in the example, ECU20 determines the third sensor signal S3, which represents an intermediate value (excluding the first sensor signal S1 representing the maximum value and the second sensor signal S2 representing the minimum value), as a normal sensor signal. Furthermore, ECU20 detects the pedal operation amount based on this normal third sensor signal S3.

[0086] Furthermore, as another variation of this detection method, there is the following detection method. For example, the ECU 20 may also determine that sensor signals falling within the reference range described below are normal sensor signals, where the reference range is the range between the upper limit obtained by adding a predetermined value to the sensor signal representing the intermediate value among the first to third sensor signals S1 to S3, and the lower limit obtained by subtracting the predetermined value. That is, as... Figure 9As shown in the example, ECU20 sets the reference range R1 between the upper limit obtained by adding a predetermined value Th1 to the normal third sensor signal S3, which represents the intermediate value among the first to third sensor signals S1 to S3, and the lower limit obtained by subtracting a predetermined value Th2. Figure 9 In the example, the second sensor signal S2 enters the reference range R1. In this case, the ECU20 not only determines the third sensor signal S3, which represents the intermediate value, as a normal sensor signal, but also determines the second sensor signal S2, which enters the reference range R1 of the third sensor signal S3, as a normal sensor signal, and detects the pedal operation amount based on the normal second sensor signal S2 and the third sensor signal S3.

[0087] Next, refer to Figures 10A to 10C Other examples illustrating methods for detecting pedal operation amount.

[0088] In other examples of the method for detecting pedal operation amount, the ECU 20 sets a reference range between an upper limit obtained by adding a predetermined value to a predetermined sensor signal from the first to third sensor signals S1 to S3, and a lower limit obtained by subtracting a predetermined value from the upper limit. Furthermore, the ECU 20 determines whether sensor signals indicating abnormal values ​​and normal sensor signals are those that have entered the reference range set for the predetermined sensor signal, using majority decision. In this detection method, the predetermined sensor signal can be arbitrarily set from the first to third sensor signals S1 to S3. Moreover, the values ​​added to and subtracted from the predetermined sensor signal can be fixed values ​​or can be changed according to factors such as vehicle speed.

[0089] Specifically, in Figures 10A to 10C In the example shown, a predetermined sensor signal that can be arbitrarily set from the first to the third sensor signals S1 to S3 is designated as the first sensor signal S1. The ECU 20 sets a reference range R2 between the upper limit obtained by adding a predetermined value Th3 to the first sensor signal S1 and the lower limit obtained by subtracting a predetermined value Th4. Furthermore, a majority decision is made to determine whether the second sensor signal S2 and the third sensor signal S3 fall within the reference range R2, thus distinguishing between normal sensor signals and abnormal signals.

[0090] exist Figure 10AIn the example shown, neither the second sensor signal S2 nor the third sensor signal S3 falls within the reference range R2 of the first sensor signal S1. In this case, the ECU 20, based on majority decision, determines that the first sensor signal S1 is an abnormal signal, while the second sensor signal S2 and the third sensor signal S3 are normal signals. Furthermore, the ECU 20 detects the pedal operation amount based on these normal second sensor signal S2 and third sensor signal S3.

[0091] exist Figure 10B In the example shown, the second sensor signal S2 falls within the reference range R2 of the first sensor signal S1, while the third sensor signal S3 does not. In this case, the ECU 20, based on majority decision, determines 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. Furthermore, the ECU 20 detects the pedal operation amount based on these normal first sensor signal S1 and second sensor signal S2.

[0092] exist Figure 10C In the example shown, both the second sensor signal S2 and the third sensor signal S3 fall 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 signals. Furthermore, the ECU 20 detects the pedal operation amount based on these normal first to third sensor signals S1 to S3.

[0093] The brake pedal device 10 and brake system 1 of the first embodiment described above have the following effects.

[0094] (1) The brake pedal device 10 of the first embodiment includes three sensors that output signals corresponding to the operation amount of the brake pedal 60. The three sensors include one magnetic sensor 40 and two inductive sensors 41 and 42. Furthermore, the two inductive sensors 41 and 42 are arranged apart from each other, so that their own detection coils will not detect the movement of the target metal of other inductive sensors besides the target metal of their own inductive sensors.

[0095] Therefore, the brake pedal device 10 is structured to detect the amount of brake pedal operation using multiple non-contact sensors with different detection principles, such as the magnetic sensor 40 and the inductive sensor. Thus, even if the output signal of one sensor becomes abnormal due to the proximity of a magnetic or conductive foreign object that the sensors are not well-suited for, the output signals of the other sensors can remain normal. Therefore, the brake pedal device 10 ensures the redundancy of the sensor output signals, and the electronic control unit 20 makes a majority decision among the output signals of the three sensors, thereby accurately detecting the amount of pedal operation.

[0096] Furthermore, the two inductive sensors 41 and 42 are configured separately from each other, preventing their respective detection coils from detecting movement of the target metal of other inductive sensors besides their own. Therefore, even if a conductive foreign object intrudes between the detection coil and target metal of one inductive sensor, the output signals of the other inductive sensors can remain normal. Thus, by preventing simultaneous failure of multiple inductive sensors, the brake pedal device 10 ensures the redundancy of sensor output signals, enabling the ECU 20 to accurately detect the pedal operation amount.

[0097] Furthermore, the brake pedal device 10 includes one magnetic sensor 40 and two inductive sensors 41 and 42. Therefore, even if the magnetic sensor 40 malfunctions due to the proximity of a magnetic foreign object, the output signals of the two inductive sensors 41 and 42 can remain normal. Thus, the brake pedal device 10 can ensure the redundancy of the sensor output signals, enabling the ECU 20 to accurately detect the amount of pedal operation.

[0098] (2) In the brake pedal device 10 of the first embodiment, the detection coil 412 of the first inductive sensor 41 is provided on the first side of the housing 70, and the detection coil 422 of the second inductive sensor 42 is provided on the second side of the housing 70. In addition, in this embodiment, the first side corresponds to the right side 74, and the second side corresponds to the left side 75.

[0099] Therefore, by distributing the two detection coils 412 and 422 of the two inductive sensors 41 and 42 respectively on the first and second sides of the housing 70, it is possible to prevent the inductive sensors 41 and 42 from being adjacent to each other. Thus, it is possible to prevent the simultaneous failure of multiple inductive sensors 41 and 42 due to foreign objects in the conductor.

[0100] (3) For the braking system 1 of the first embodiment, as an example of the method for detecting the amount of pedal operation executed by the ECU 20, the following detection method is used. That is, the difference is calculated for all combinations of two sensor signals selected from the first to third sensor signals S1 to S3. Furthermore, the ECU 20 determines the two sensor signals with the smallest difference among the calculated multiple differences as normal values.

[0101] Therefore, even if one of the sensor signals S1 to S3 is an abnormal value, the brake pedal 60 can be detected based on the normal sensor signal instead of using the sensor signal representing the abnormal value.

[0102] (4) For the braking system 1 of the first embodiment, as another example of the method for detecting the amount of pedal operation executed by the ECU 20, there is the following detection method. That is, the sensor signals representing intermediate values ​​among the first to third sensor signals S1 to S3, excluding the sensor signal representing the maximum value and the sensor signal representing the minimum value, are determined to be normal sensor signals.

[0103] Therefore, even if one of the three sensor signals is an abnormal value, the ECU20 can detect the amount of brake pedal operation based on the normal sensor signal instead of using the sensor signal indicating the abnormal value.

[0104] (5) For the braking system 1 of the first embodiment, as another example of the method for detecting the amount of pedal operation executed by the ECU 20, the following detection method is used. That is, the reference range R2 is set between the upper limit obtained by adding a predetermined value Th3 to a predetermined sensor signal and the lower limit obtained by subtracting a predetermined value Th4. Furthermore, the ECU 20 uses majority decision to determine whether two sensor signals other than the predetermined sensor signal fall within the reference range R2 set for the predetermined sensor signal, thereby distinguishing between sensor signals indicating abnormal values ​​and normal sensor signals.

[0105] Therefore, by setting a reference range R2 for a specified sensor signal among the output signals of the three sensors, and making a majority decision on whether the other two sensor signals fall within the reference range R2, it is possible to distinguish between sensor signals indicating abnormal values ​​and normal sensor signals.

[0106] (Second Implementation)

[0107] The second embodiment will be described. The second embodiment changes the structure of the three sensors in the brake pedal device 10 compared to the first embodiment, but is otherwise the same as the first embodiment, so only the parts that are different from the first embodiment will be described.

[0108] like Figure 11 As shown, the brake pedal device 10 of the second embodiment includes three inductive sensors 41 to 43 as multiple sensors that output signals corresponding to the amount of pedal operation. In the following description, the three inductive sensors included in the brake pedal device 10 of the second embodiment will be referred to as the first inductive sensor 41, the second inductive sensor 42, and the third inductive sensor 43. 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 detects the correct amount of pedal operation based on the output signals of the first to third inductive sensors 41 to 43 and controls the drive of the brake circuit 30.

[0109] In the second embodiment, the structures of the first inductive sensor 41 and the second inductive sensor 42 are the same as those in the first embodiment. Figures 2-5 The first inductive sensor 41 and the second inductive sensor 42 described herein have the same structure. That is, as... Figure 2 and Figure 5 As shown, a first circuit board 413, which houses the first detection coil 412 and other components of the first inductive sensor 41, is provided on the right side 74 of the housing 70. On the other hand, as... Figures 3-5 As shown, a second circuit board 423, which houses the second detection coil 422 and other components of the second inductive sensor 42, is provided on the left side 75 of the housing 70.

[0110] Furthermore, such as Figure 12 and Figure 13 As shown, the third inductive sensor 43 of the brake pedal device 10 in the second embodiment is disposed inside the housing 70. The inside of the housing 70 forms a sealed space 76 to prevent foreign objects from entering from the outside. The third inductive sensor 43 has a third target metal 431 that moves together with the shaft member 61, and a third circuit board 433 on which a third detection coil 432 and a third transceiver circuit are mounted. The third target metal 431 is fixed to the end of the shaft member 61 and moves together with the shaft member 61. On the other hand, the third circuit board 433 is disposed on the inner wall of the housing 70 at a position opposite to the third target metal 431 in the axial direction of the axis CL. The third transceiver circuit applies an alternating current to the transmitting coil of the third detection coil 432, and detects the position of the third target metal 431 by utilizing the physical principle of the eddy current generated by the third target metal 431 moving above the coil, based on the change in the inductance of the receiving coil. The third inductive sensor 43 is disposed in a sealed space 76 inside the housing 70, where conductive foreign objects cannot penetrate, thus preventing false detections caused by conductive foreign objects.

[0111] In the second embodiment described above, the three inductive sensors 41-43 will not detect movement of the target metal of any inductive sensor other than the target metal of its own inductive sensor. Furthermore, the first circuit board 413 of the first inductive sensor 41 is disposed on the right side 74 of the housing 70, and the second circuit board 423 of the second inductive sensor 42 is disposed on the left side 75 of the housing 70. The third inductive sensor 43 is disposed inside the housing 70. Thus, by arranging the three inductive sensors 41-43 at a distance from each other, simultaneous sensor malfunctions due to conductive foreign objects can be prevented. Therefore, by preventing simultaneous malfunctions of multiple inductive sensors, the brake pedal device 10 ensures the redundancy of the sensor output signals, enabling accurate detection of the pedal operation amount in the ECU 20.

[0112] (Third Implementation)

[0113] The third embodiment will be described. The third embodiment is a variation of the first and second embodiments, in which the method of setting the inductive sensor for the brake pedal device 10 is changed.

[0114] like Figure 14 As shown, the brake pedal device 10 of the third embodiment has two inductive sensors 41 and 42 on the left side of the housing 70. Two circuit boards 413 and 423, on which the detection coils 412 and 422 of the two inductive sensors 41 and 42 are mounted, are arranged on the left side 75 of the housing 70 in a manner oriented in the vehicle's longitudinal direction. On the other hand, two target metals 411 and 421 of the two inductive sensors 41 and 42 are arranged on the left side of the brake pedal 60 in a manner oriented in the vehicle's longitudinal direction. The two target metals 411 and 421 of the two inductive sensors 41 and 42 extend from the left side of the brake pedal 60 to the vehicle floor side. The lower ends of these two target metals 411 and 421 are respectively positioned opposite to the circuit boards 413 and 423 on which the corresponding detection coils 412 and 422 and transceiver circuits are provided. The two target metals 411 and 421 move parallel to the left side 75 as the brake pedal 60 swings.

[0115] Furthermore, the brake pedal device 10 of the third embodiment, in addition to the two inductive sensors 41 and 42 described above, also includes a third inductive sensor 43. The third inductive sensor 43 may, for example, be as follows: Figure 2 It is configured on the right side 74 of the housing 70 as shown. Alternatively, the third inductive sensor 43 can also be configured as follows: Figure 12 and Figure 13It is configured inside the housing 70 as shown. Alternatively, the third inductive sensor 43 can also be, for example, with... Figure 14 The two inductive sensors 41 and 42 shown are arranged together on the left side 75 of the housing 70 in a manner that is aligned in the longitudinal direction of the vehicle.

[0116] The third embodiment described above, by arranging the three inductive sensors 41-43 at a distance from each other, also prevents simultaneous sensor malfunctions caused by conductive foreign objects. Therefore, by preventing simultaneous malfunctions of multiple inductive sensors, the brake pedal device 10 ensures the redundancy of the sensor output signals, enabling the ECU 20 to accurately detect the pedal operation amount.

[0117] Alternatively, in the structure of the third embodiment, a magnetic sensor 40 may be provided instead of the third inductive sensor 43.

[0118] (Fourth implementation)

[0119] The fourth embodiment will be described. The fourth embodiment is also a variation of the first to third embodiments, except that the method of setting the inductive sensor for the brake pedal device 10 is changed.

[0120] like Figure 15 and Figure 16 As shown, the brake pedal device 10 of the fourth embodiment includes three inductive sensors 41 to 43 as multiple sensors that output signals corresponding 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 also 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 to 43 are provided inside the housing 70. The inside of the housing 70 is a sealed space 76 that prevents foreign objects from entering from the outside.

[0121] The first inductive sensor 41 has a first circuit board 413 on which a first detection coil 412 and a first transceiver circuit are mounted, and a first target metal 411 disposed opposite to the first circuit board 413. The first circuit board 413 on which the first detection coil 412 and the first transceiver circuit are mounted is disposed on the inner wall of the right side surface 74 of the housing 70. The first target metal 411 is disposed so as to extend from the shaft member 61 toward the front of the vehicle. The end of the first target metal 411 opposite to the shaft member 61 is disposed in a position opposite to the first circuit board 413 in the axial direction of the axis CL. The first target metal 411 moves parallel to the first circuit board 413 as the brake pedal 60 and the shaft member 61 swing.

[0122] The second inductive sensor 42 has a second circuit board 423 on which a second detection coil 422 and a second transceiver circuit are mounted, and a second target metal 421 disposed opposite to the second circuit board 423. The second circuit board 423 on which the second detection coil 422 and the second transceiver circuit are mounted is disposed on the inner wall of the left side 75 of the housing 70. The second target metal 421 is disposed so as to extend from the shaft member 61 toward the front of the vehicle. The end of the second target metal 421 opposite to the shaft member 61 is disposed in a position opposite to the second circuit board 423 in the axial direction of the axis CL. The second target metal 421 moves parallel to the second circuit board 423 as the brake pedal 60 and the shaft member 61 swing.

[0123] The third inductive sensor 43 includes a third circuit board 433 on which a third detection coil 432 and a third transceiver circuit are mounted, and a third target metal 431 disposed opposite to the third circuit board 433. The third target metal 431 is fixed to the end of the shaft member 61 and moves together with the shaft member 61. The third circuit board 433 is disposed on the inner wall of the housing 70 at a position opposite to the third target metal 431 in the axial direction of the axis CL.

[0124] In the fourth embodiment described above, the first to third inductive sensors 41 to 43 are all disposed in a sealed space 76 inside the housing 70, where conductive foreign objects will not intrude, thus preventing false detections caused by conductive foreign objects. 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 object enters the housing 70, simultaneous malfunction of the first to third inductive sensors 41 to 43 due to the foreign object can be prevented. Thus, by preventing simultaneous malfunction of multiple inductive sensors 41 to 43, the brake pedal device 10 ensures the redundancy of the sensor output signals, enabling accurate detection of pedal operation in the ECU 20.

[0125] Alternatively, in the structure of the fourth embodiment, a magnetic sensor 40 may be provided instead of one of the first to third inductive sensors 41 to 43.

[0126] (5th to 7th embodiments)

[0127] The fifth to seventh embodiments differ from the first to fourth embodiments described above in that the structure of the braking system 1 is modified. Furthermore, in the fifth to seventh embodiments, the brake pedal device 10 is described as having one magnetic sensor 40 and two inductive sensors 41 and 42, but this is not a limitation. In the fifth to seventh embodiments, the brake pedal device 10 may, for example, have three inductive sensors 41 to 43.

[0128] (Fifth Embodiment)

[0129] like Figure 17 As shown, the braking system 1 of the fifth embodiment includes a first ECU 21 and a second ECU 22. A magnetic sensor 40 and the first ECU 21 are connected via a first signal line 51. A first inductive sensor 41 and the first ECU 21 are connected via a second signal line 52. A second inductive sensor 42 and the second ECU 22 are connected via a third signal line 53. Therefore, 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.

[0130] The first ECU 21 and the second ECU 22 are connected via an in-vehicle LAN, such as CAN (Controller Area Network) communication, which serves as the signal transmission unit 55, enabling bidirectional communication. 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. Furthermore, 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. Thus, the first ECU 21 and the second ECU 22 can detect the correct pedal operation amount based on the output signals of the three sensors 40 to 42, and control the brake circuit 30 accordingly.

[0131] The braking system 1 of the fifth embodiment described above is structured such that at least one of the multiple sensors 40-42 is directly input to the first ECU 21 and the second ECU 22 via signal lines. Therefore, for this braking system 1, even if one of the ECUs, the first ECU 21 and the second ECU 22, fails, the other ECU can still activate the braking circuit 30. Thus, this braking system 1 ensures redundancy of both the sensor output signals and the ECUs.

[0132] Furthermore, the braking system 1 of the fifth embodiment, like the braking system 1 described in the first embodiment, also includes three sensors 40 to 42. Therefore, the braking system 1 of the fifth embodiment can also ensure the redundancy of the output signals of the sensors 40 to 42, and the pedal operation amount can be accurately detected in the ECU 20.

[0133] (Sixth Embodiment)

[0134] like Figure 18As shown, the braking 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 via a first signal line 51. The first inductive sensor 41 and the second ECU 22 are connected via a second signal line 52, and the second inductive sensor 42 and the second ECU 22 are connected via a third signal line 53. Therefore, the output signal of the magnetic sensor 40 is input to the first ECU 21. On the other hand, the output signals of the first inductive sensor 41 and the second inductive sensor 42 are input to the second ECU 22.

[0135] The first ECU 21 and the second ECU 22 are connected via an in-vehicle LAN, such as CAN communication, which serves as the signal transmission unit 55, enabling bidirectional communication. 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. Furthermore, 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. Thus, the first ECU 21 and the second ECU 22 can respectively detect the correct pedal operation amount based on the output signals of the three sensors 40 to 42, and control the brake circuit 30 accordingly.

[0136] The braking system 1 of the sixth embodiment described above is also a structure in which the output signals of at least one of the multiple sensors 40 to 42 are directly input to the first ECU 21 and the second ECU 22 via signal lines. Therefore, the braking system 1 of the sixth embodiment can also achieve the same effect as that of the fifth embodiment.

[0137] (Seventh Embodiment)

[0138] like Figure 19As shown, the braking 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 configured to be divided into a first separation signal and a second separation signal, which are respectively input to the first ECU 21 and the second ECU 22. Specifically, the magnetic sensor 40 and the first ECU 21 are connected via a first signal line 51. The magnetic sensor 40 and the second ECU 22 are connected via a second signal line 52. Thus, the output signal of the magnetic sensor 40 is divided into a first separation signal and a second separation signal, with the first separation signal input to the first ECU 21 and the second separation signal input to the second ECU 22. Furthermore, 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 signals detected by the pair of magnetic circuit sections and magnetic detection sections disposed within the one magnetic sensor 40. Alternatively, the first separation signal input to the first ECU21 and the second separation signal input to the second ECU22 can be the same two output signals detected from two pairs of magnetic circuit sections and magnetic detection sections configured in a magnetic sensor 40.

[0139] Furthermore, the first inductive sensor 41 and the first ECU 21 are connected via the third signal line 53. The second inductive sensor 42 and the second ECU 22 are connected via the fourth signal line 54. Therefore, for the first ECU 21, the output signal of the input magnetic sensor 40 is separated into a first separation signal and the output signal of the first inductive sensor 41. On the other hand, for the second ECU 22, the output signal of the input magnetic sensor 40 is separated into a second separation signal and the output signal of the second inductive sensor 42.

[0140] The first ECU 21 and the second ECU 22 are connected via an in-vehicle LAN, such as CAN communication, which serves as the signal transmission unit 55, enabling bidirectional communication. Therefore, the first disconnect signal from the magnetic sensor 40 and the output signal from the first inductive sensor 41 input to the first ECU 21 are transmitted to the second ECU 22 via the signal transmission unit 55. Furthermore, the second disconnect signal from the magnetic sensor 40 and the output signal from the second inductive sensor 42 input to the second ECU 22 are transmitted to the first ECU 21 via the signal transmission unit 55. Thus, the first ECU 21 and the second ECU 22 can detect the correct pedal operation amount based on the output signals from the three sensors 40 to 42, and control the brake circuit 30 accordingly.

[0141] In the braking system 1 of the seventh embodiment described above, the output signal of the magnetic sensor 40 is configured to be divided into a first separation signal and a second separation signal, the first separation signal is input to the first ECU 21, and the second separation signal is input to the second ECU 22.

[0142] Therefore, 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 malfunctions, sometimes the first ECU 21 detects the first separation signal as normal, while the second ECU 22 detects the second separation signal as abnormal. In this case, the first ECU 21 determines the signals from the three sensors containing the first separation signal to be normal, while the second ECU 22 determines the second separation signal from the magnetic sensor 40 to be abnormal. In such a case, by comparing the determination result of the first ECU 21 with the determination result of the second ECU 22, it can be assumed that an abnormality has occurred in the second ECU 22 or the magnetic sensor 40, and the braking circuit 30 can be activated by the first ECU 21. Therefore, the braking system 1 of the seventh embodiment can detect an abnormality in either the first ECU 21 or the second ECU 22.

[0143] (Eighth Embodiment)

[0144] The eighth embodiment will be described. In contrast to the first to seventh embodiments, the eighth embodiment includes a fourth sensor 44 in the brake pedal device 10. 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 force applied by the driver to the brake pedal 60, a switch sensor that only detects whether the brake pedal 60 is pressed, or a motion sensor that observes the driver's actions.

[0145] The fourth sensor 44 and the ECU 20 are connected via the fourth signal line 54. Therefore, the output signal of the fourth sensor 44 is input to the ECU 20. In addition, the output signals of the magnetic sensor 40 and the two inductive sensors 41 and 42 are also input to the ECU 20.

[0146] In the eighth embodiment, the ECU 20 is also configured to determine the pedal operation amount by comparing the output signals of the three sensors 40-42 with the output signal of the fourth sensor 44. In this case, the ECU 20 may also determine the signal among the output signals of the three sensors 40-42 that deviates significantly from the output signal of the fourth sensor 44 as an abnormal signal.

[0147] Alternatively, if a switch sensor is used as the fourth sensor 44, the ECU 20 can also start detecting the operation amount of the brake pedal 60 through the three sensors 40-42 based on the output signal of the fourth sensor 44. This configuration reduces the detection load on the ECU 20.

[0148] Alternatively, if a motion sensor is used as the fourth sensor 44, the ECU 20 can also use the three sensors 40-42 to detect the amount of operation of the brake pedal 60 while adjusting the vehicle braking force brought by the brake circuit 30 based on the output signal of the fourth sensor 44.

[0149] Furthermore, in the eighth embodiment, the brake pedal device 10 is described as having one magnetic sensor 40, two inductive sensors 41 and 42, and a fourth sensor 44, but it is not limited to this. For example, the brake pedal device 10 may also have three inductive sensors 41 to 43 and a fourth sensor 44.

[0150] (Other implementation methods)

[0151] (1) In the above embodiments, an organ-type brake pedal device was described as an example of the brake pedal device 10, but it is not limited thereto. The brake pedal device 10 may also be a suspended brake pedal device, for example. A suspended brake pedal device 10 is a structure in which the part of the brake pedal 60 for the driver to step on is positioned below the pivot point CL in the vertical direction when the vehicle is mounted.

[0152] (2) In the above embodiments, electric brakes 31 to 34 have been described as an example of the brake circuit 30 provided in the braking system 1, but it is not limited thereto. The brake circuit 30 may, for example, adopt a structure in which the hydraulic pressure of the brake fluid is increased by the action of a hydraulic pump or master cylinder, and the brake pads are actuated by driving the brake wheel cylinders located on each wheel.

[0153] (3) In the above embodiments, the inductive sensor is placed on the side of the housing or in the sealed space inside the housing, but it is not limited to this. The inductive sensor can also detect a maze structure.

[0154] This disclosure is not limited to the embodiments described above, but can be appropriately modified. Furthermore, the embodiments described above are not unrelated to each other, and can be appropriately combined except in cases where they are explicitly impossible to combine. Furthermore, in the embodiments described above, the elements constituting the embodiment are not necessarily essential, except where they are specifically stated to be necessary or are explicitly considered necessary in principle. Furthermore, in the embodiments described above, when referring to the number, value, quantity, range, etc., of the constituent elements of the embodiment, the quantity is not limited to that specific number, except where it is specifically stated to be necessary or is explicitly limited to a specific number in principle. Furthermore, in the embodiments described above, when referring to the shape, positional relationship, etc., of the constituent elements, the shape, positional relationship, etc., are not limited to that shape, positional relationship, etc., except where it is specifically stated or is limited to a specific shape, positional relationship in principle.

[0155] The control unit and method described in this disclosure can be implemented using a dedicated computer provided by means of a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the control unit and method described in this disclosure can also be implemented using a dedicated computer provided by means of a processor configured using one or more dedicated hardware logic circuits. Alternatively, the control unit and method described in this disclosure can also be implemented using one or more dedicated computers configured by a combination of a processor and memory programmed to perform one or more functions and a processor configured by one or more hardware logic circuits. Furthermore, the computer program can also be stored as instructions to be executed by the computer in a computer-readable, non-transitory tangible storage medium.

Claims

1. A brake pedal device used in a braking system, wherein an electronic control unit detects the amount of brake pedal operation based on the output signal of a sensor provided with the brake pedal device, and performs drive control on the brake circuit, characterized in that... have: The casing is fixed to the vehicle; The aforementioned brake pedal is configured to swing relative to the aforementioned housing about a predetermined axis, and is operated by the driver; and At least three of the aforementioned sensors output signals corresponding to the amount of brake pedal operation. The at least three of the aforementioned sensors include at least one magnetic sensor and at least two inductive sensors. The aforementioned magnetic sensor includes a magnetic circuit section that operates together with the brake pedal and a magnetic detection section that detects changes in the magnetic field generated by the magnetic circuit section. At least two of the aforementioned inductive sensors each have a target metal that actuates together with the brake pedal and a detection coil that detects the actuation of the target metal. At least two of the aforementioned inductive sensors are arranged apart from each other in such a way that their own detection coils will not detect the movement of the target metal of any other inductive sensor besides the target metal of the inductive sensor itself.

2. A brake pedal device used in a braking system, wherein an electronic control unit detects the amount of brake pedal operation based on the output signal of a sensor provided with the brake pedal device, and performs drive control on the brake circuit, characterized in that... have: The casing is fixed to the vehicle; The aforementioned brake pedal is configured to swing relative to the aforementioned housing about a predetermined axis, and is operated by the driver; and At least three of the aforementioned sensors output signals corresponding to the amount of brake pedal operation. At least three of the above sensors include at least three inductive sensors. At least three of the aforementioned inductive sensors each have a target metal that actuates together with the brake pedal and a detection coil that detects the actuation of the target metal. At least three of the aforementioned inductive sensors are arranged apart from each other in such a way that their own detection coils will not detect the movement of the target metal of other inductive sensors besides the target metal of their own inductive sensor.

3. The brake pedal device as described in claim 1 or 2, characterized in that, The detection coil of one of the aforementioned inductive sensors is disposed on a first side of the housing facing the axis of the shaft. The detection coil of another of the aforementioned inductive sensors is disposed on a second side of the housing facing the axis opposite to the axis.

4. The brake pedal device as described in claim 1 or 2, characterized in that, The target metal and the detection coil of the aforementioned inductive sensor are disposed in a sealed space inside the housing to prevent the intrusion of foreign objects.

5. The brake pedal device as described in claim 1 or 2, characterized in that, The aforementioned inductive sensor detects the swing angle of the brake pedal relative to the aforementioned housing.

6. A braking system that performs drive control on a braking circuit for braking a vehicle, characterized in that... have: The brake pedal device includes a brake pedal fixed to the vehicle housing, a brake pedal that is pivotally mounted relative to the housing and operated by the driver, and at least three sensors that output signals corresponding to the amount of brake pedal operation; and The electronic control unit detects the amount of brake pedal operation based on the output signals of at least three of the aforementioned sensors, and performs drive control on the brake circuit. The at least three of the aforementioned sensors include at least one magnetic sensor and at least two inductive sensors, or include at least three of the aforementioned inductive sensors. Multiple inductive sensors are arranged apart from each other in such a way that their own detection coils will not detect the movement of the target metal of other inductive sensors besides the target metal of their own inductive sensor.

7. The braking system as claimed in claim 6, characterized in that, The aforementioned electronic control device includes a first electronic control device and a second electronic control device. The output signals of at least three of the aforementioned sensors are input to the first electronic control device. The output signals of at least three of the aforementioned sensors, excluding the specified sensors, are input to the aforementioned second electronic control device. The braking system is configured such that the output signals of the sensors communicate bidirectionally between the first electronic control device and the second electronic control device.

8. The braking system as claimed in claim 7, characterized in that, The output signal of the aforementioned magnetic sensor is divided into a first separation signal and a second separation signal. The braking system is configured such that the first separation signal is input to the first electronic control device, and the second separation signal is input to the second electronic control device.

9. The braking system as described in any one of claims 6 to 8, characterized in that, When the signals input from the three aforementioned sensors to the aforementioned electronic control device, and transformed into comparable values ​​based on the output characteristics of each sensor, are respectively referred to as the first sensor signal, the second sensor signal, and the third sensor signal, The aforementioned electronic control device is configured to compare the differences between the first sensor signal and the second sensor signal, the differences between the first sensor signal and the third sensor signal, and the differences between the second sensor signal and the third sensor signal, and to use the two sensor signals with the smallest calculated differences as normal values ​​to detect the amount of brake pedal operation.

10. The braking system as described in any one of claims 6 to 8, characterized in that, When the signals input from the three aforementioned sensors to the aforementioned electronic control device, and transformed into comparable values ​​based on the output characteristics of each sensor, are respectively referred to as the first sensor signal, the second sensor signal, and the third sensor signal, The aforementioned electronic control device is configured such that, when the three sensor signals are different, the sensor signal representing the intermediate value (excluding the sensor signal representing the maximum value and the sensor signal representing the minimum value) is determined to be a normal sensor signal.

11. The braking system as described in any one of claims 6 to 8, characterized in that, When the signals input from the three aforementioned sensors to the aforementioned electronic control device, and transformed into comparable values ​​based on the output characteristics of each sensor, are respectively referred to as the first sensor signal, the second sensor signal, and the third sensor signal, The aforementioned electronic control device determines whether the other two sensor signals besides the specified sensor signal have entered a reference range. This reference range is the range between the upper limit obtained by adding a specified value to the specified sensor signal among the three sensor signals and the lower limit obtained by subtracting the specified value. If the signals from the other two sensors fall within the specified reference range for sensor signals, then all three sensor signals are considered to be normal. If one of the other two sensor signals enters the specified reference range for the sensor signal, the sensor signal entering the reference range and the specified sensor signal are determined to be normal signals; the sensor signal not entering the reference range is determined to be an abnormal signal. The braking system described above is configured such that, if neither of the other two sensor signals enters the specified reference range of the sensor signal, the two signals that do not enter the reference range are determined to be normal signals, and the specified sensor signal is an abnormal signal.

12. The braking system as described in any one of claims 6 to 8, characterized in that, In addition to the at least three sensors described above, the aforementioned brake pedal device also has a fourth sensor that outputs a signal corresponding to the amount of brake pedal operation. The aforementioned electronic control device is configured to determine the amount of brake pedal operation by comparing the output signals of at least three of the aforementioned sensors with the output signal of the aforementioned fourth sensor.

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