Signal processing device

Abstract

A signal processing device (3) for processing a sensor signal output from a sensor (6) of a brake pedal device (4) is provided with a behavior determination unit (16), a filter circuit (17), and a filter constant setting unit (18). The behavior determination unit (16) determines, on the basis of the sensor signal, whether or not a rebound behavior has occurred after the pedal arm (8) is rotated in the closing direction and reaches the fully closed position. The filter circuit (17) performs smoothing processing on the sensor signal in accordance with the filter constant, generates a control signal for braking the vehicle, and generates a control signal that increases the degree of smoothing of the change in the sensor signal as the filter constant increases. The filter constant setting unit (18) sets the filter constant when the behavior determination unit (16) determines that the rebound behavior occurs to be larger than the filter constant when the behavior determination unit (16) determines that the rebound behavior does not occur.

Description

[0001] Cross-reference to related applications

[0002] This application is based on Japanese Patent Application No. 2023-071628 filed on April 25, 2023, the contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a signal processing device for a brake-by-wire system. Background Art

[0004] Conventionally, there are known brake-by-wire systems in which an electronic control device controls vehicle braking based on an electrical signal output from a brake pedal device mounted on the vehicle. Furthermore, there are known accelerator-by-wire systems in which an electronic control device controls vehicle acceleration and deceleration based on an electrical signal output from an accelerator pedal device.

[0005] Patent Document 1 describes an accelerator pedal device for a drive-by-wire acceleration system. The accelerator pedal device includes a pedal arm that rotates in response to a pedal force applied by the driver; a spring mechanism that applies a reaction force to the pedal arm against the pedal force; and two fully closed stoppers that stop the pedal arm in a fully closed position. The fully closed position, referred to as the rest position in Patent Document 1, restricts the rotation of the pedal arm when no pedal force is applied to the pedal arm. Furthermore, the fully closed stoppers are referred to as rest stoppers in Patent Document 1. By including two fully closed stoppers, the accelerator pedal device suppresses the clashing sound caused by the pedal arm violently rotating due to the force of the spring mechanism and colliding with the fully closed stoppers when the driver releases his foot from the pedal arm.

[0006] Prior art literature Patent Literature Patent Document 1: Japanese Patent No. 4374180 Summary of the Invention

[0007] However, when the driver removes his foot from the pedal arm, if the pedal arm collides with the fully closed stopper with a large impact force due to the action of the spring mechanism, the pedal arm may sometimes rebound near the fully closed position. In this case, the sensor signal output from the sensor of the accelerator pedal device also vibrates near the fully closed position. Therefore, if the electronic control unit controls the acceleration and deceleration of the vehicle based on this sensor signal, the vehicle is accelerated or decelerated against the driver's intention to release the accelerator, resulting in a problem of deterioration in driving performance. However, this problem is not described in Patent Document 1. The problem of deterioration in driving performance caused by such rebound behavior of the pedal arm is not limited to the wire-controlled acceleration system, but may also occur in the wire-controlled brake system.

[0008] Typically, the spring mechanism in a brake pedal system used in a brake-by-wire system has a greater force than that in an accelerator pedal system. Therefore, when the driver releases their foot from the pedal arm, the impact force between the pedal arm and the fully closed stopper is greater in the brake pedal system than in the accelerator system, resulting in a greater rebound of the pedal arm. In this situation, the sensor signal output from the brake pedal system's sensor also fluctuates significantly near the fully closed position. Consequently, if the electronic control unit applies vehicle brakes based on this sensor signal, the vehicle brakes against the driver's intention to release the brakes, resulting in a deterioration in drivability.

[0009] Furthermore, in a brake-by-wire system, if the electronic control device brakes the vehicle based on a sensor signal that vibrates due to rebound movement of the pedal arm, unnecessary braking increases, accelerating wear of the brake pads.

[0010] To address these issues, signal processing devices used in brake-by-wire systems have considered setting a large filter constant in the filter circuit that smoothes the sensor signals output from the sensors. However, setting a large filter constant can lead to a delay in the vehicle's braking response when the driver depresses or resets the pedal arm, deteriorating drivability.

[0011] In order to prevent the pedal arm from bouncing back, it is also conceivable to enlarge the size of the fully closed stopper to physically absorb the impact force of the pedal arm. However, if the fully closed stopper is enlarged, the brake pedal device will also be enlarged, which may increase the manufacturing cost.

[0012] An object of the present disclosure is to improve drivability at low cost without increasing the size of a brake pedal device in a signal processing device used in a brake-by-wire system.

[0013] According to one aspect of the present disclosure, a signal processing device is used in a brake-by-wire system to process a sensor signal output from a sensor of a brake pedal device.

[0014] The brake pedal device includes a support body, a pedal arm, a spring mechanism, a fully closed stopper, and a sensor. The support body is mounted on the vehicle. The pedal arm is configured to be rotatable relative to the support body about a predetermined axis, and rotates in the opening direction when the driver's pedal force increases, and rotates in the closing direction when the driver's pedal force decreases or is released. The spring mechanism applies a force to the pedal arm that acts as a reaction force relative to the driver's pedal force. The fully closed stopper stops the pedal arm at a fully closed position where the pedal arm's rotation in the closing direction is restricted when no pedal force is applied to the pedal arm. The sensor outputs a sensor signal corresponding to the angle or stroke of the pedal arm.

[0015] The signal processing device that processes the sensor signal includes a behavior determination unit, a filter circuit, and a filter constant setting unit. The behavior determination unit determines, based on the sensor signal, whether rebound behavior has occurred after the pedal arm rotates in the closing direction and reaches the fully closed position. The filter circuit smoothes the sensor signal according to the filter constant and generates a control signal for braking the vehicle. A larger filter constant increases the degree of smoothing of sensor signal variations. The filter constant setting unit sets the filter constant to a larger value when the behavior determination unit determines that rebound behavior has occurred than when the behavior determination unit determines that rebound behavior has not occurred.

[0016] Thus, if the behavior determination unit determines that rebound behavior has occurred, the filter constant setting unit sets the filter constant to a larger value, causing the filter circuit to generate a control signal that significantly smoothes changes in the sensor signal. Consequently, even if the driver releases their foot from the pedal arm and the pedal arm rebounds, the brake-by-wire system's electronic control unit immediately releases the vehicle brakes based on the control signal that significantly smoothes changes in the sensor signal, thereby improving drivability.

[0017] On the other hand, if the behavior determination unit determines that rebound behavior is not occurring, the filter constant setting unit sets the filter constant to a smaller value than when rebound behavior is occurring, and the filter circuit generates a control signal that minimizes the smoothing of sensor signal changes. Therefore, when the driver performs a pedal operation or a reset operation while resting their foot on the pedal arm, the electronic control unit of the brake-by-wire system brakes the vehicle with high responsiveness based on the control signal that minimizes the smoothing of sensor signal changes, thereby improving drivability.

[0018] Furthermore, according to the signal processing of the signal processing device, even when the pedal arm rebounds, the electronic control device immediately cancels the vehicle braking command, thereby preventing unnecessary vehicle braking operations and unnecessary wear of brake pads, etc.

[0019] Furthermore, the signal processing performed by this signal processing device allows for increased force applied by the spring mechanism of the brake pedal device without increasing the size of the fully closed stopper that physically absorbs the impact force of the pedal arm, thereby improving drivability through control. This prevents the brake pedal device from being oversized, which would otherwise be associated with an increase in the size of the fully closed stopper, and reduces manufacturing costs.

[0020] According to another aspect of the present disclosure, a signal processing device is used in a brake-by-wire system to process a sensor signal output from a sensor of a brake pedal device.

[0021] The brake pedal device includes a support body, a pedal arm, a spring mechanism, a fully closed stopper, and a sensor. The support body is mounted on the vehicle. The pedal arm is configured to be rotatable relative to the support body about a predetermined axis, and rotates in the opening direction when the driver's pedal force increases, and rotates in the closing direction when the driver's pedal force decreases or is released. The spring mechanism applies a force to the pedal arm that acts as a reaction force relative to the driver's pedal force. The fully closed stopper stops the pedal arm at a fully closed position where the pedal arm's rotation in the closing direction is restricted when no pedal force is applied to the pedal arm. The sensor outputs a sensor signal corresponding to the angle or stroke of the pedal arm.

[0022] The signal processing device that processes the sensor signal includes a behavior determination unit and a signal switching unit. The behavior determination unit determines, based on the sensor signal, whether rebound behavior has occurred after the pedal arm rotates in the closing direction and reaches the fully closed position. If the behavior determination unit determines that rebound behavior has occurred, the signal switching unit switches the control signal for braking the vehicle to a signal value indicating that the pedal arm is in the fully closed position (hereinafter referred to as the "fully closed signal") for a predetermined time and outputs the signal.

[0023] Thus, when the behavior determination unit determines that a rebound behavior has occurred, the signal switching unit switches the control signal to a fully closed signal for a predetermined time and outputs it. Therefore, even if the driver releases their foot from the pedal arm and the pedal arm rebounds, the electronic control unit of the brake-by-wire system immediately releases the vehicle brakes based on the fully closed signal, thereby improving drivability.

[0024] On the other hand, if the behavior determination unit determines that rebound behavior has not occurred, the signal switching unit does not switch the control signal to the fully closed signal. Therefore, when the driver performs a pedal operation or a reset operation with their foot resting on the pedal arm, the electronic control unit of the brake-by-wire system brakes the vehicle with high response based on the control signal or sensor signal after the sensor signal has been subjected to normal processing, thereby improving drivability.

[0025] Furthermore, according to the signal processing of the signal processing device of another aspect of the present disclosure, as in the first aspect of the present disclosure, unnecessary wear of brake pads and the like can be prevented without increasing the number of unnecessary vehicle brake operations.

[0026] Furthermore, according to the signal processing of the signal processing device according to another aspect of the present disclosure, similarly to the one aspect of the present disclosure, there is no need to increase the size of the fully closed stopper, thereby preventing the brake pedal device from being enlarged and reducing manufacturing costs.

[0027] In addition, the reference numerals in parentheses attached to each component etc. show an example of the correspondence relationship between the component etc. and the specific component etc. described in the embodiment described later. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the configuration of a brake-by-wire system using the signal processing device according to the first embodiment.

[0029] Figure 2 This is a block diagram of an electronic control device incorporating the signal processing device according to the first embodiment.

[0030] Figure 3 This is a flowchart showing a control process executed by the signal processing device according to the first embodiment.

[0031] Figure 4 This is a graph showing the relationship between the sensor signal and the control signal in the signal processing device according to the first embodiment.

[0032] Figure 5 : is a graph showing the relationship between the sensor signal and the control signal in the signal processing device of the comparative example.

[0033] Figure 6 This is a block diagram of an electronic control device incorporating a signal processing device according to a second embodiment.

[0034] Figure 7 This is a block diagram of an electronic control device incorporating a signal processing device according to a second embodiment.

[0035] Figure 8 This is a flowchart showing a control process executed by the signal processing device according to the second embodiment.

[0036] Figure 9 This is a graph showing the relationship between the sensor signal and the control signal in the signal processing device according to the second embodiment.

[0037] Figure 10 This is a graph showing the relationship between the sensor signal and the control signal, and the operation speed of the pedal arm in the signal processing device according to the third embodiment.

[0038] Figure 11 This is a graph showing the relationship between the sensor signal and the control signal, and the dwell time of the pedal arm at the fully closed position, in the signal processing device according to the fourth embodiment.

[0039] Figure 12 This is a graph showing the relationship between the sensor signal and the control signal, the operation speed of the pedal arm, and the acceleration of the operation of the pedal arm in the signal processing device according to the fifth embodiment.

[0040] Figure 13 This is a graph showing the relationship between the angle or stroke of the pedal arm and the force acting on the pedal arm from the spring mechanism in the signal processing device according to the fifth embodiment.

[0041] Figure 14 This is a graph showing the relationship between the sensor signal and the control signal in the signal processing device according to the sixth embodiment.

[0042] Figure 15 FIG. 1 is a schematic diagram showing the configuration of a brake-by-wire system using a signal processing device according to a seventh embodiment.

[0043] Figure 16 This is a graph showing the relationship between the sensor signal and the control signal, and the output value of the load sensor in the signal processing device according to the seventh embodiment.

[0044] Figure 17 This is a schematic diagram of the configuration of a brake-by-wire system using a signal processing device according to an eighth embodiment. DETAILED DESCRIPTION

[0045] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In the following embodiments, identical or equivalent parts are denoted by the same reference numerals, and their description will be omitted.

[0046] (First embodiment) The first embodiment will be described with reference to the accompanying drawings. Figure 1 As shown, in the first embodiment, a signal processing device 3 is incorporated into a portion of the electronic circuitry of an electronic control unit 2 of a brake-by-wire system 1 for vehicle braking. Hereinafter, the electronic control unit 2 will be referred to as "ECU 2." ECU stands for Electronic Control Unit. Furthermore, the signal processing device 3 is not limited to being incorporated into the ECU 2; it may also be configured as an integrated circuit, such as an IC or ASIC, integrated with the sensor 6 provided in the brake pedal device 4.

[0047] First, the schematic configuration of the brake-by-wire system 1 will be described.

[0048] like Figure 1 As shown, a brake-by-wire system 1 includes a brake pedal device 4, an ECU 2, and a brake mechanism 5. Brake-by-wire system 1 is a system in which ECU 2 drives and controls brake mechanism 5 based on sensor signals output from sensor 6 included in brake pedal device 4, thereby braking the vehicle. In particular, brake-by-wire system 1 using signal processing device 3 of the first embodiment is a complete brake-by-wire system in which components of brake mechanism 5 (e.g., a master cylinder) are not mechanically connected to brake pedal device 4.

[0049] The brake pedal device 4 includes a housing 7 as a support body, a pedal arm 8, a fully closed stopper 9, a spring mechanism 10, a sensor 6, and the like. Figure 1A cross-sectional view of the brake pedal arrangement 4 is shown.

[0050] The housing 7 of the brake pedal device 4 is fixed to the vehicle by bolts (not shown). Specifically, the housing 7 is fixed to the floor 22 or the dash panel in the vehicle interior. An internal space 11 is provided inside the housing 7. The sensor 6, the spring mechanism 10, and the shaft 12 are provided in the internal space 11. In addition, the sensor 6 is provided at a position overlapping the shaft 12 in its axial direction. Therefore, the shaft 12 is provided relative to the sensor 6. Figure 1 The shaft 12 is arranged to be rotatable relative to the housing 7 about its own axis CL.

[0051] The pedal arm 8 is formed in a generally plate-like shape and is fixed to the shaft 12 via a connecting member 13. One end of the connecting member 13 is fixed to the lower surface of the pedal arm 8, and the other end is fixed to the shaft 12. Therefore, the pedal arm 8 is provided so as to be rotatable relative to the housing 7 about the axis CL of the shaft 12.

[0052] The brake pedal device 4 of the first embodiment is an accordion-type pedal device. An accordion-type pedal device is one in which all or most of the pedal tread 14, the portion of the pedal arm 8 to which the driver's pedal force is applied, is positioned vertically above the vehicle when mounted, i.e., above the vehicle, relative to the rotational axis CL of the pedal arm 8. Furthermore, in an accordion-type pedal device, the pedal arm 8 rotates toward the floor 22 or dash panel within the vehicle cabin as the driver's pedal force applied to the pedal arm 8 increases.

[0053] In the following description, the direction in which the pedal arm 8 rotates due to an increase in the driver's pedal force applied to the pedal arm 8 is referred to as an opening direction, and the direction in which the pedal arm 8 rotates due to a decrease or release of the driver's pedal force applied to the pedal arm 8 is referred to as a closing direction. Furthermore, the opening direction is sometimes referred to as a pedal depression direction, and the closing direction is sometimes referred to as a pedal return direction.

[0054] The pedal arm 8 is restricted from rotating in the opening direction by the fully open stopper 15. The fully open stopper 15 stops the pedal arm 8 at the fully open position where the pedal arm 8 is restricted from rotating in the opening direction when the driver's pedal force is applied to the pedal arm 8. Figure 1 The dotted line 8a shows a state where the pedal arm 8 is in contact with the fully open stopper 15 and the pedal arm 8 is located at the fully open position. In addition, the fully open stopper 15 is preferably made of an elastic member such as rubber, resin, or silicone.

[0055] On the other hand, the pedal arm 8 is restricted from rotating in the closing direction by the fully closed stopper 9. The fully closed stopper 9 stops the pedal arm 8 at the fully closed position where the pedal arm 8 is restricted from rotating in the closing direction when no pedal force is applied to the pedal arm 8 by the driver. Figure 1The solid line 8b shows the state where the pedal arm 8 is in contact with the fully closed stopper 9 and the pedal arm 8 is located in the fully closed position. In addition, the fully closed stopper 9 is also preferably made of an elastic member such as rubber, resin, or silicone.

[0056] The spring mechanism 10 is configured to include one or more springs. The spring mechanism 10 generates a reaction force that acts as a reaction force to the driver's pedal force applied to the pedal arm 8. By including the spring mechanism 10, the brake pedal device 4 can obtain the same reaction force as when the pedal arm 8 is connected to the master cylinder, that is, when a reaction force based on hydraulic pressure is obtained, even if the mechanical connection between the pedal arm 8 and the conventional master cylinder is eliminated.

[0057] The sensor 6 detects the pedal arm 8 or the shaft 12 and outputs a sensor signal corresponding to the angle or stroke of the pedal arm 8. As the sensor 6, various sensors such as a magnetic sensor, an inductive sensor, a light sensor, a load sensor, a rotary encoder, and a potentiometer can be used. The sensor 6 is not limited to being set at a position overlapping with the axis CL direction of the shaft 12, but can also be set at a position away from the axis CL. The sensor signal output by the sensor 6 is transmitted to the ECU 2. In addition, in this specification, the sensor signal refers to the "sensor raw value" output from the sensor 6.

[0058] ECU2 has a microcomputer and its peripheral circuits, including a processor that performs control processing and calculation processing, a ROM, RAM and other storage units that store programs, data, etc. The storage unit is composed of a non-transitory physical storage medium. ECU2 performs various control processing and calculation processing based on the programs stored in the storage unit, and controls the operation of each device connected to the output port. Specifically, the ECU2 of the first embodiment includes a signal processing device 3 in a part of its electronic circuit. The signal processing device 3 processes the sensor signal transmitted from the sensor 6 and the like, and generates a control signal. The control circuit 24 of ECU2 drives and controls the brake mechanism 5 based on the control signal generated by the signal processing device 3.

[0059] Various mechanisms can be used as the braking mechanism 5. For example, as the braking mechanism 5, an electric brake can be used in which an electric motor is driven according to a command from the ECU2 to press the brake pads against the disc brake rotor to brake each wheel. Alternatively, for example, as the braking mechanism 5, a structure can be used in which the hydraulic pressure of the brake fluid is increased by the action of a master cylinder or a hydraulic pump, the wheel cylinders arranged at each wheel are driven, and the brake pads are actuated. In addition, the braking mechanism 5 can also perform normal control, ABS control, and VSC control, etc. according to the command from the ECU2. ABS is the abbreviation of Anti-lock Braking System, and VSC is the abbreviation of Vehicle Stability Control.

[0060] Next, refer to Figure 2 The configuration of the signal processing device 3 that processes the sensor signal output from the sensor 6 of the brake pedal device 4 will be described.

[0061] like Figure 2 As shown, the signal processing device 3 includes a behavior determination unit 16 , a filter circuit 17 , and a filter constant setting unit 18 as functional blocks formed of electronic circuits.

[0062] The sensor signal output from the sensor 6 is input to the behavior determination unit 16 and the filter circuit 17 .

[0063] The behavior determination unit 16 is a circuit that determines, based on the sensor signal, whether a rebound behavior has occurred after the pedal arm 8 rotates in the closing direction and reaches the fully closed position. The behavior determination unit 16 is configured to determine whether a rebound behavior has occurred before the rebound behavior occurs. The specific method used by the behavior determination unit 16 to determine whether a rebound behavior has occurred will be described in detail in the third to seventh embodiments described below.

[0064] Filter circuit 17 smoothes the sensor signal according to a filter constant to generate a control signal for braking the vehicle. The larger the filter constant, the more the filter circuit 17 generates a control signal that smoothes the sensor signal's variations. Filter circuit 17 can employ various methods, such as a moving average filter and a low-pass filter. For example, when a moving average filter is employed as filter circuit 17, the filter constant is the moving average time. For example, when a low-pass filter is employed as filter circuit 17, the filter constant is a time constant.

[0065] The filter constant setting unit 18 is a circuit that sets the filter constant used by the filter circuit 17 based on the determination result of the behavior determination unit 16. The filter constant setting unit 18 sets the filter constant to be larger when the behavior determination unit 16 determines that a bounce behavior has occurred than when the behavior determination unit 16 determines that a bounce behavior has not occurred. Specifically, when the behavior determination unit 16 determines that a bounce behavior has occurred, the filter constant setting unit 18 sets the filter constant to the "filter constant for bounce suppression." On the other hand, when the behavior determination unit 16 determines that a bounce behavior has not occurred, the filter constant setting unit 18 sets the filter constant to the "filter constant for normal control." The "filter constant for bounce suppression" is a value larger than the "filter constant for normal control," and causes the filter circuit 17 to generate a control signal that increases the degree of smoothing of changes in the sensor signal.

[0066] Next, refer to Figure 3The flowchart of FIG. 1 will explain the control process executed by the signal processing device 3. In the following description and drawings, steps are abbreviated as "S".

[0067] exist Figure 3 In S10, the behavior determination unit 16 determines whether a rebound behavior is likely to occur based on the sensor signal input from the sensor 6. That is, the behavior determination unit 16 determines whether a rebound behavior occurs after the pedal arm 8 rotates in the closing direction and reaches the fully closed position before the rebound behavior occurs.

[0068] If, in S10, the behavior determination unit 16 determines that rebound behavior is likely to occur, processing proceeds to S20. In S20, the filter constant setting unit 18 sets the filter constant to the "bounce suppression filter constant." This causes the filter circuit 17 to generate a control signal that smoothes the sensor signal changes. The control circuit 24 of the ECU 2 controls the driving of the brake mechanism 5 based on this control signal. Therefore, even if the driver removes their foot from the pedal arm 8 and rebound behavior occurs after the pedal arm 8 reaches the fully closed position, the control circuit 24 of the ECU 2 can immediately release the vehicle braking command to the brake mechanism 5.

[0069] On the other hand, if the behavior determination unit 16 determines in S10 that there is no possibility of rebound behavior, the process proceeds to S30. In S30, the filter constant setting unit 18 sets the filter constant to the "normal control filter constant." This causes the filter circuit 17 to generate a control signal that relatively minimizes the degree of smoothing of sensor signal changes. The control circuit 24 of the ECU 2 controls the driving of the brake mechanism 5 based on this control signal. Therefore, when the driver performs a depressing operation or a reset operation while resting their foot on the pedal arm 8, the control circuit 24 of the ECU 2 can brake the vehicle with high response.

[0070] Next, regarding the control processing performed by the signal processing device 3, refer to Figure 4 The diagram shows the relationship between the sensor signal and the control signal.

[0071] Figure 4 The horizontal axis represents time, and the vertical axis represents the angle of the pedal arm 8, that is, the pedal angle. On the vertical axis, "fully closed" refers to the angle when the pedal arm 8 is in the fully closed position, indicating that the driver has not applied the brakes. On the other hand, "fully open" on the vertical axis refers to the angle when the pedal arm 8 is in the fully open position, indicating that the driver has fully applied the brakes. Figure 4 The dashed line S represents the sensor signal, and the solid line C represents the control signal.

[0072] Figure 4The sensor signal shown by the single-dot chain line S is the sensor raw value, which represents the actual angle of the pedal arm 8. Therefore, as shown by the single-dot chain line S, at time t1, the driver starts to step on the pedal arm 8, and the pedal arm 8 starts to rotate from the fully closed position to the open direction. At time t2, the pedal arm 8 reaches the fully open position. At time t3, the driver removes his foot from the pedal arm 8, and the pedal arm 8 starts to rotate from the fully open position to the closed direction only by the force of the spring mechanism 10. At time t4, the pedal arm 8 reaches the fully closed position and collides with the fully closed stopper 9. From time t4 to t5, the fully closed stopper 9 contracts under the action of the collision force of the pedal arm 8, and from time t5 to t6, the fully closed stopper 9 returns to its original shape due to its own elastic force. Therefore, during the period from time t6 to t9, the pedal arm 8 produces a rebound behavior.

[0073] Figure 4 The solid line C represents the control signal generated by the filter circuit 17. From time t0 to t4, the behavior determination unit 16 determines that there is no possibility of rebound behavior, and the filter constant setting unit 18 sets the filter constant to the "normal control filter constant." This allows the filter circuit 17 to generate a control signal that minimizes the smoothing of sensor signal changes. Therefore, from time t1 to t2, when the driver steps on the pedal arm 8, the delay time Δα between the sensor signal and the control signal is minimal. Consequently, when the pedal arm 8 is stepped on, the control circuit 24 of the ECU 2 can brake the vehicle with high response.

[0074] If the behavior determination unit 16 determines that there is a possibility of rebound behavior between times t3 and t4, the filter constant setting unit 18 sets the filter constant to a "bounce suppression filter constant" for a predetermined period starting from time t4 (for example, between times t4 and t9). This causes the filter circuit 17 to generate a control signal that smoothes the sensor signal changes. Therefore, even if rebound behavior of the pedal arm 8 occurs between times t4 and t9, the control circuit 24 of the ECU 2 can immediately release the vehicle braking command to the brake mechanism 5 based on the control signal.

[0075] At time t9, a certain time after time t4, the filter constant setting unit 18 sets the filter constant to the "normal control filter constant." This allows the control circuit 24 of the ECU 2 to brake the vehicle with high response when the driver resumes depressing the pedal arm 8 after time t9.

[0076] For comparison with the control process of the first embodiment described above, in the signal processing device of the comparative example, referring to Figure 5 The diagram below illustrates the relationship between the sensor signal and the control signal.

[0077] Although not shown in the figure, the signal processing device of the comparative example includes only a filter circuit and does not include the behavior determination unit 16 and the filter constant setting unit 18. The filter constant of the filter circuit of the comparative example is always set to a value similar to the "bounce suppression filter constant" described in the first embodiment.

[0078] Figure 5 The sensor signal indicated by the one-dot chain line S, that is, the actual angle of the pedal arm 8 , is the same as that described in the first embodiment.

[0079] Figure 5 The control signal shown by the solid line C is generated by the filter circuit of the comparative example. During the period from time t1 to time t2 when the driver steps on pedal arm 8, the delay time Δβ between the sensor signal and the control signal is greater than the delay time Δα described in the first embodiment. Therefore, in the comparative example, when the pedal arm 8 is stepped on, the vehicle's braking response is delayed, resulting in degraded drivability.

[0080] Compared to the above-described comparative example, the signal processing device 3 of the first embodiment achieves the following operational effects due to the configuration.

[0081] The signal processing device 3 of the first embodiment includes a behavior determination unit 16, a filter circuit 17, and a filter constant setting unit 18. The behavior determination unit 16 determines whether a rebound behavior has occurred in the pedal arm 8 based on the sensor signal. The filter circuit 17 smoothes the sensor signal according to the filter constant and generates a control signal. The filter constant setting unit 18 sets the filter constant to a larger value when the behavior determination unit 16 determines that a rebound behavior has occurred than when the behavior determination unit 16 determines that a rebound behavior has not occurred.

[0082] Thus, when the behavior determination unit 16 determines that a rebound behavior has occurred, the filter constant setting unit 18 sets the filter constant to a larger value, and the filter circuit 17 generates a control signal that significantly smoothes the sensor signal changes. Therefore, even if the driver removes their foot from the pedal arm 8 and the pedal arm 8 rebounds, the control circuit 24 of the ECU 2 immediately releases the vehicle braking command to the brake mechanism 5 based on the control signal that significantly smoothes the sensor signal changes. This improves drivability.

[0083] On the other hand, when the driver performs a pedaling operation or a reset operation while resting their foot on the pedal arm 8, the pedal arm 8 does not rotate in the closing direction solely due to the force of the spring mechanism 10 and collide with the fully closed stopper 9. Therefore, the behavior determination unit 16 determines that no rebound behavior occurs. Therefore, the filter constant setting unit 18 sets the filter constant to a smaller value than when rebound behavior occurs, and the filter circuit 17 generates a control signal that minimizes the smoothing of sensor signal changes. Therefore, when the driver performs a pedaling operation or a reset operation while resting their foot on the pedal arm 8, the control circuit 24 of the ECU 2 brakes the vehicle with high responsiveness based on the control signal that minimizes the smoothing of sensor signal changes, thereby improving drivability.

[0084] Furthermore, based on the signal processing by the signal processing device 3, even if the pedal arm 8 rebounds, the control circuit 24 of the ECU 2 immediately cancels the vehicle braking command to the brake mechanism 5. Therefore, unnecessary vehicle brake operations are not increased, and unnecessary wear of the brake pads and the like can be prevented.

[0085] Furthermore, the signal processing by the signal processing device 3 allows for increased force applied by the spring mechanism 10 of the brake pedal device 4 without increasing the size of the fully closed stopper 9 that physically absorbs the impact force of the pedal arm 8. This allows for improved drivability through control. This prevents an increase in the size of the brake pedal device 4, which would otherwise be associated with an increase in the size of the fully closed stopper 9, and reduces manufacturing costs.

[0086] Furthermore, in the signal processing device 3 of the first embodiment, the behavior determination unit 16 may determine the magnitude of the bounce behavior based on the sensor signal. In this case, the larger the bounce behavior, the larger the filter constant setting unit 18 may set the "bounce suppression filter constant." Alternatively, the larger the bounce behavior, the longer the filter constant setting unit 18 applies the "bounce suppression filter constant" to the filter circuit 17. Specifically, the larger the bounce behavior, the longer the filter constant setting unit 18 increases the time from setting the "bounce suppression filter constant" to returning to the "normal control filter constant."

[0087] (Second embodiment) The second embodiment is described below. The second embodiment changes the configuration of the signal processing device 3 and its control method compared to the first embodiment. The rest is the same as the first embodiment, so only the differences from the first embodiment will be described.

[0088] like Figure 6As shown, the signal processing device 3 of the second embodiment includes a behavior determination unit 16 , a filter circuit 17 , a fully closed signal generation unit 19 , and a signal switching unit 20 as functional blocks constituted by electronic circuits.

[0089] The sensor signal output from the sensor 6 is input to the behavior determination unit 16 and the filter circuit 17 .

[0090] The behavior determination unit 16 is a circuit that determines, based on the sensor signal, whether a rebound behavior has occurred after the pedal arm 8 rotates in the closing direction and reaches the fully closed position. The behavior determination unit 16 is configured to determine whether a rebound behavior has occurred before the rebound behavior occurs. The specific method by which the behavior determination unit 16 determines whether a rebound behavior has occurred will be described in detail in the third to seventh embodiments described below.

[0091] The filter circuit 17 smoothes the sensor signal according to the filter constant and generates a control signal for braking the vehicle. Various filter methods, such as a moving average filter and a low-pass filter, can be used as the filter circuit 17. In the second embodiment, the filter circuit 17 is not essential, and the signal processing device 3 may also be configured without the filter circuit 17.

[0092] The fully closed signal generating unit 19 is a circuit that generates and outputs a fully closed signal. In this specification, the fully closed signal refers to a signal value indicating that the pedal arm 8 is in the fully closed position.

[0093] The signal switching unit 20 is a circuit that switches and outputs the control signal generated by the filter circuit 17 and the fully closed signal generated by the fully closed signal generating unit 19 based on the determination result of the behavior determining unit 16. When the behavior determining unit 16 determines that no rebound behavior occurs, as shown in FIG. Figure 6 As shown in FIG. 1 , the signal switching unit 20 outputs the control signal generated by the filter circuit 17. On the other hand, if the behavior determination unit 16 determines that a rebound behavior has occurred, then Figure 7 As shown, the signal switching unit 20 switches the control signal to the fully closed signal generated by the fully closed signal generating unit 19 and outputs the signal for a predetermined time.

[0094] Next, refer to Figure 8 The flowchart of FIG. 1 illustrates the control process executed by the signal processing device 3 according to the second embodiment.

[0095] exist Figure 8 In S110, the behavior determination unit 16 determines whether a rebound behavior is likely to occur based on the sensor signal input from the sensor 6. That is, the behavior determination unit 16 determines whether a rebound behavior occurs after the pedal arm 8 rotates in the closing direction and reaches the fully closed position before the rebound behavior occurs.

[0096] If the behavior determination unit 16 determines in S110 that rebound behavior is likely to occur, the process proceeds to S120. In S120, the signal switching unit 20 switches the control signal to the fully closed signal generated by the fully closed signal generation unit 19 and outputs it for a predetermined time. The control circuit 24 of the ECU 2 then controls the braking mechanism 5 based on this fully closed signal. Therefore, even if the driver removes their foot from the pedal arm 8 and rebound behavior occurs after the pedal arm 8 reaches the fully closed position, the control circuit 24 of the ECU 2 can immediately release the vehicle braking command to the braking mechanism 5.

[0097] On the other hand, if the behavior determination unit 16 determines in S110 that there is no possibility of rebound behavior, the process proceeds to S130. In S130, the signal switching unit 20 outputs the normal control signal generated by the filter circuit 17. Furthermore, if the signal processing device 3 does not include the filter circuit 17, the signal switching unit 20 outputs the sensor signal as the control signal. The control circuit 24 of the ECU 2 controls the driving of the brake mechanism 5 based on this control signal or sensor signal. Therefore, when the driver performs a stepping operation and a reset operation with their foot resting on the pedal arm 8, the control circuit 24 of the ECU 2 can brake the vehicle with high response.

[0098] Next, regarding the control processing performed by the signal processing device 3, refer to Figure 9 The diagram below illustrates the relationship between the sensor signal, control signal, and fully closed signal.

[0099] Figure 9 The sensor signal indicated by the one-dot chain line S, that is, the actual angle of the pedal arm 8 , is the same as that described in the first embodiment.

[0100] Figure 9 The solid line C represents the control signal and the fully closed signal output from the signal switching unit 20. From time t0 to t4, the behavior determination unit 16 determines that there is no possibility of rebound behavior, and the signal switching unit 20 outputs the normal control signal generated by the filter circuit 17. Therefore, from time t1 to t2, when the driver steps on the pedal arm 8, the delay time Δα between the sensor signal and the control signal is extremely small. Consequently, when the pedal arm 8 is stepped on, the control circuit 24 of the ECU 2 can brake the vehicle with high response.

[0101] If the behavior determination unit 16 determines that rebound behavior is likely to occur between times t3 and t4, the signal switching unit 20 switches the control signal to the fully closed signal generated by the fully closed signal generation unit 19 and outputs it for a predetermined period of time starting from time t4 (for example, between times t4 and t9). Therefore, even if rebound behavior occurs between times t4 and t9, the control circuit 24 of the ECU 2 can immediately release the vehicle braking command to the brake mechanism 5 based on the fully closed signal.

[0102] At time t9, a certain time after time t4, the signal switching unit 20 switches to and outputs the normal control signal generated by the filter circuit 17. As a result, after time t9, when the driver resumes depressing the pedal arm 8, the control circuit 24 of the ECU 2 can brake the vehicle with high response.

[0103] The signal processing device 3 of the second embodiment described above achieves the following operational effects.

[0104] The signal processing device 3 of the second embodiment includes a behavior determination unit 16 and a signal switching unit 20. The behavior determination unit 16 determines whether a rebound behavior has occurred in the pedal arm 8 based on the sensor signal. If the behavior determination unit 16 determines that a rebound behavior has occurred, the signal switching unit 20 switches the control signal to a fully closed signal for a predetermined time and outputs the signal.

[0105] Thus, when the behavior determination unit 16 determines that a rebound behavior has occurred, the signal switching unit 20 switches the control signal to a fully closed signal for a predetermined time and outputs it. Therefore, even if the driver releases his foot from the pedal arm 8 and the pedal arm 8 rebounds, the control circuit 24 of the ECU 2 immediately releases the vehicle braking command to the brake mechanism 5 based on the fully closed signal, thereby improving drivability.

[0106] On the other hand, when the driver performs a pedal operation or a reset operation while resting their foot on the pedal arm 8, the pedal arm 8 does not rotate in the closing direction solely due to the force of the spring mechanism 10 and collide with the fully closed stopper 9. Therefore, the behavior determination unit 16 determines that no rebound behavior occurs. Therefore, the signal switching unit 20 does not switch the control signal to the fully closed signal. Therefore, when the driver performs a pedal operation or a reset operation while resting their foot on the pedal arm 8, the control circuit 24 of the ECU 2 brakes the vehicle with high response based on the control signal or sensor signal after the sensor signal has been subjected to normal processing, thereby improving drivability.

[0107] Furthermore, according to the signal processing of the signal processing device 3 , as in the first embodiment, unnecessary operation frequency of the vehicle brakes is not increased, and unnecessary wear of the brake pads and the like can be prevented.

[0108] Furthermore, according to the signal processing of the signal processing device 3 , similarly to the first embodiment, there is no need to increase the size of the fully closed stopper 9 , thereby preventing an increase in size of the brake pedal device 4 and reducing manufacturing costs.

[0109] Furthermore, in the signal processing device 3 of the second embodiment, the behavior determination unit 16 may also determine the magnitude of the rebound behavior based on the sensor signal. In this case, the greater the rebound behavior, the longer the signal switching unit 20 outputs the fully closed signal. Specifically, the greater the rebound behavior, the longer the signal switching unit 20 extends the time from when the normal control signal generated by the filter circuit 17 is switched to the fully closed signal generated by the fully closed signal generating unit 19 until it switches back to the normal control signal generated by the filter circuit 17.

[0110] (Third to Seventh Embodiments) The third to seventh embodiments describe a specific method by which the behavior determination unit 16 determines whether a rebound behavior has occurred, as compared to the first and second embodiments. Furthermore, in the descriptions of the third to seventh embodiments, it is assumed that the signal processing device 3 includes the behavior determination unit 16, the filter circuit 17, and the filter constant setting unit 18, as in the first embodiment. However, this is not limiting. In the descriptions of the third to seventh embodiments, the signal processing device 3 may also include the behavior determination unit 16, the filter circuit 17, the fully closed signal generating unit 19, and the signal switching unit 20, as in the second embodiment.

[0111] (Third embodiment) Figure 10 The relationship between the sensor signal and the control signal under the pedal angle described in the upper part of the graph is the same as that referred to in the description of the first embodiment. Figure 4 The diagrams of are substantially the same, so the description is omitted. In addition, the signal processing device 3 of the third embodiment can output a control signal that is considered to be fully closed when the sensor signal is less than the value indicating fully closed. Specifically, Figure 10 In the upper portion of the graph, the signal processing device 3 can output a control signal that is considered fully closed during the period from time t4 to t6 and the period from time t8 to time t9. This also applies to the first and second embodiments described above and the fourth to seventh embodiments described below.

[0112] Figure 10The line V in the lower portion of the graph represents the movement speed of the pedal arm 8. The behavior determination unit 16 included in the signal processing device 3 of the third embodiment can calculate the movement speed of the pedal arm 8 based on the differential value of the sensor signal. Furthermore, the behavior determination unit 16 determines that a rebound behavior has occurred when the pedal arm 8 rotates in the closing direction at a speed greater than a predetermined speed threshold Th_v, or when the pedal arm 8 reaches the fully closed position at a speed greater than the predetermined speed threshold Th_v.

[0113] The predetermined speed threshold Th_v is set based on, for example, the pedal force characteristics of the spring mechanism 10 included in the brake pedal device 4 through experiments and is pre-stored in the memory of the signal processing device 3. The memory is a non-transitory physical storage medium. Furthermore, a speed greater than the predetermined speed threshold Th_v refers to a speed that is greater than the predetermined speed threshold Th_v as an absolute value, regardless of the direction in which the pedal arm 8 moves.

[0114] In the third embodiment described above, the behavior determination unit 16 determines that a rebound behavior has occurred when the pedal arm 8 rotates in the closing direction at a speed greater than the predetermined speed threshold Th_v or when the pedal arm 8 reaches the fully closed position at a speed greater than the predetermined speed threshold Th_v.

[0115] Thus, when the driver releases his foot from the pedal arm 8, the pedal arm 8 rotates in the closing direction at a speed greater than a predetermined speed threshold Th_v solely due to the force of the spring mechanism 10. If this collides with the fully closed stopper 9 in the fully closed position, a rebound action occurs. Therefore, the action determination unit 16 calculates the action speed of the pedal arm 8 when rotating in the closing direction based on the differential value of the sensor signal, thereby enabling determination of whether a rebound action will occur before the rebound action occurs.

[0116] In addition, in the signal processing device 3 of the third embodiment, the behavior determination unit 16 may also determine the size of the rebound behavior based on the sensor signal. Specifically, the faster the speed of the pedal arm 8 when rotating in the closing direction, the larger the rebound behavior is determined by the behavior determination unit 16. In this case, the filter constant setting unit 18 described in the first embodiment may also be configured to set the "filter constant for bounce suppression" to be larger as the rebound behavior is larger. In addition, it may also be configured to extend the time for the filter circuit 17 to apply the "filter constant for bounce suppression" as the rebound behavior is larger. In addition, in this case, the signal switching unit 20 described in the second embodiment may also be configured to extend the time for outputting the fully closed signal as the rebound behavior is larger.

[0117] (Fourth embodiment) Figure 11The relationship between the sensor signal and the control signal under the pedal angle described in the upper part of the graph is the same as that referred to in the description of the first embodiment. Figure 4 The diagrams are substantially the same, so their description is omitted.

[0118] Figure 11 The line I in the lower part of the graph represents the count value of the time the pedal arm 8 stays in the fully closed position and the position closer to the closing direction than the fully closed position. The behavior determination unit 16 of the signal processing device 3 of the fourth embodiment has a counter circuit that counts the time the pedal arm 8 is in the fully closed position and the position closer to the closing direction than the fully closed position, and is capable of counting this time. Specifically, Figure 11 The vertical axis of the lower portion of the graph represents the count value obtained by counting the time when the pedal arm 8 is in the fully closed position and in the closing direction relative to the fully closed position. If the pedal arm 8 moves from the fully closed position to the opening direction, the count value is reset. Figure 11 In line I of the graph of , the count value is reset at time t1, counting starts at time t4, and the count value is reset at time t6.

[0119] The behavior determination unit 16 determines that a rebound behavior has occurred if the time the pedal arm 8 remains in the fully closed position or in a position closer to the closing direction than the fully closed position, i.e., the counter value, is less than a predetermined time threshold Th_t. The time threshold Th_t is set to a value shorter than the time it takes for a person to vibrate the pedal arm 8 multiple times at the fastest speed using their foot (e.g., 0.25 seconds) and is pre-stored in the memory of the signal processing device 3.

[0120] In the fourth embodiment described above, the behavior determination unit 16 determines that a rebound behavior has occurred when the time the pedal arm 8 stays at the fully closed position or at a position closer to the closing direction than the fully closed position is shorter than the predetermined time threshold Th_t.

[0121] Thus, if the pedal arm 8 rotates in the closing direction solely due to the force of the spring mechanism 10 and collides with the fully closed stopper 9, the pedal arm 8 will only contact the fully closed stopper 9 for a short period of time, far enough that a person cannot operate the pedal arm with their foot at maximum speed, and then a rebound action will occur. Therefore, the action determination unit 16 can determine whether a rebound action will occur before a rebound action occurs by detecting the time that the pedal arm 8 remains in the fully closed position and at a position further in the closing direction than the fully closed position.

[0122] In addition, in the signal processing device 3 of the fourth embodiment, the behavior determination unit 16 may also determine the size of the rebound behavior based on the sensor signal. Specifically, the shorter the time that the pedal arm 8 stays in the fully closed position and the position closer to the closing direction than the fully closed position, the greater the rebound behavior is determined by the behavior determination unit 16. In this case, the filter constant setting unit 18 described in the first embodiment may also be configured to set the "filter constant for bounce suppression" to a larger value as the rebound behavior is larger. Alternatively, the filter constant setting unit 18 may extend the time for applying the "filter constant for bounce suppression" to the filter circuit 17 as the rebound behavior is larger. In this case, the signal switching unit 20 described in the second embodiment may also be configured to extend the time for outputting the fully closed signal as the rebound behavior is larger.

[0123] (Fifth embodiment) Figure 12 The relationship between the sensor signal and the control signal under the pedal angle described in the upper part of the graph is the same as that referred to in the description of the first embodiment. Figure 4 The diagrams are substantially the same, so their description is omitted. Figure 12 The line V in the middle of the graph is the operating speed of the pedal arm 8, which is the same as that referred to in the description of the third embodiment. Figure 10 The lines V in the lower portion of the graph are substantially the same, and therefore description thereof is omitted.

[0124] Figure 12 The line G in the lower part of the graph represents the acceleration of the movement of the pedal arm 8. The behavior determination unit 16 of the signal processing device 3 of the fifth embodiment is capable of calculating the acceleration of the movement of the pedal arm 8 based on the second-order differential value of the sensor signal. Moreover, the behavior determination unit 16 determines that a rebound behavior has occurred when the pedal arm 8 rotates in the closing direction with an acceleration greater than the prescribed acceleration threshold Th_a, or when the pedal arm 8 reaches the fully closed position with an acceleration greater than the prescribed acceleration threshold Th_a. In addition, the acceleration greater than the prescribed acceleration threshold Th_a refers to an acceleration greater than the prescribed acceleration threshold Th_a as an absolute value, regardless of the direction in which the pedal arm 8 moves. In addition, the prescribed acceleration threshold Th_a is a fixed value, or a value uniquely determined according to the angle or stroke of the pedal arm 8 based on the characteristics of the spring mechanism 10 and the mass of the pedal arm 8.

[0125] Figure 13 This is a graph showing the relationship between the angle θ or stroke of the pedal arm 8 and the force F(θ) acting on the pedal arm 8 from the spring mechanism 10 . This graph is set when the spring mechanism 10 is designed and is called the pedaling force characteristic of the spring mechanism 10 . Figure 13The solid line D in the graph shows the relationship between the angle θ or stroke of the pedal arm 8 when the pedal arm 8 rotates in the opening direction and the force F(θ) acting on the pedal arm 8 from the spring mechanism 10. Furthermore, the dashed-dotted line E shows the relationship between the angle θ or stroke of the pedal arm 8 when the pedal arm 8 rotates in the closing direction and the force F(θ) acting on the pedal arm 8 from the spring mechanism 10.

[0126] Here, when the pedal arm 8 rotates in the closing direction, the force F(θ) acting on the pedal arm 8 from the spring mechanism 10 at a predetermined angle θ, the acceleration a at the predetermined angle θ, and the mass m of the pedal arm 8 have the following relationship according to the equation of motion:

[0127] F(θ)=ma… (Equation 1) According to the above-mentioned Expression 1, when the pedal arm 8 rotates in the closing direction, the acceleration a at a predetermined angle θ has the relationship expressed by the following Expression 2.

[0128] a=F(θ) / m… (Equation 2) As described above, the acting force F(θ) acting from the spring mechanism 10 on the pedal arm 8 at the predetermined angle θ has a value set at the time of design as the pedaling force characteristic of the spring mechanism 10 .

[0129] Therefore, when the pedal arm 8 rotates in the closing direction, if the acceleration a at a predetermined angle θ is less than the value obtained by dividing the force F(θ) set at the predetermined angle θ by the mass m of the pedal arm 8 during design, it is considered that the driver's foot is resting on the pedal arm 8. In this case, no rebound behavior occurs after the pedal arm 8 collides with the fully closed stopper 9.

[0130] In contrast, when the pedal arm 8 rotates in the closing direction, if the acceleration a at a predetermined angle θ is equal to the value obtained by dividing the force F(θ) set at the predetermined angle θ by the mass m of the pedal arm 8 during design, it is considered as follows. Specifically, in this case, without the driver's foot resting on the pedal arm 8, the pedal arm 8 rotates in the closing direction solely due to the force of the spring mechanism 10, resulting in a rebound behavior after the pedal arm 8 collides with the fully closed stopper 9. Furthermore, "the acceleration a at the predetermined angle θ is equal to the value obtained by dividing the force F(θ) set at the predetermined angle θ by the mass m of the pedal arm 8 during design" includes situations where the acceleration a is slightly reduced due to friction with the shaft 12, air resistance against the pedal arm 8, and other factors. Therefore, by setting the predetermined acceleration threshold Th_a to a value uniquely determined based on the angle or stroke of the pedal arm 8, based on the characteristics of the spring mechanism 10 and the mass m of the pedal arm 8, it is possible to accurately determine whether a rebound behavior has occurred. The predetermined acceleration threshold value Th_a may be determined experimentally, and is a value that uniquely determines, including an error, the degree of acceleration at which rebound occurs.

[0131] Furthermore, if the pedal arm 8 rotates at an acceleration greater than a certain fixed value, a rebound behavior occurs after the pedal arm 8 collides with the fully closed stopper 9 . Therefore, the predetermined acceleration threshold Th_a can also be determined as a certain fixed value.

[0132] In the fifth embodiment described above, when acceleration equal to or greater than the predetermined acceleration threshold Th_a occurs while the pedal arm 8 rotates in the closing direction and reaches the fully closed position, the behavior determination unit 16 determines that a rebound behavior occurs.

[0133] Thus, when the driver removes their foot from the pedal arm 8, the pedal arm 8 rotates in the closing direction at an acceleration greater than a predetermined acceleration solely due to the force of the spring mechanism 10. This causes a rebound movement when it collides with the fully closed stopper 9 in the fully closed position. Therefore, the movement determination unit 16 calculates the acceleration of the pedal arm 8 based on the second-order differential value of the sensor signal, enabling it to determine whether a rebound movement will occur before the rebound movement occurs.

[0134] Furthermore, in the fifth embodiment, the predetermined acceleration threshold value Th_a used by the behavior determination unit 16 for determining rebound behavior is a fixed value or a value uniquely determined based on the angle or stroke of the pedal arm 8, the characteristics of the spring mechanism 10, and the mass m of the pedal arm 8. This allows the behavior determination unit 16 to accurately determine whether a rebound behavior has occurred.

[0135] Furthermore, in the signal processing device 3 of the fifth embodiment, the behavior determination unit 16 may also determine the magnitude of the rebound behavior based on the sensor signal. Specifically, the greater the acceleration of the pedal arm 8 when rotating in the fully closed direction, the greater the rebound behavior determined by the behavior determination unit 16. In this case, the filter constant setting unit 18 described in the first embodiment may also set the "bounce suppression filter constant" to a larger value as the rebound behavior increases. Alternatively, the filter constant setting unit 18 may increase the time for applying the "bounce suppression filter constant" to the filter circuit 17 as the rebound behavior increases. In this case, the signal switching unit 20 described in the second embodiment may also increase the time for outputting the fully closed signal as the rebound behavior increases.

[0136] (Sixth embodiment) Figure 14 The relationship between the sensor signal and the control signal under the pedal angle recorded in the graph is the same as that referred to in the description of the first embodiment. Figure 4 The diagrams of are substantially the same, so the description is omitted. Figure 14 In the graph, for convenience of explanation, the distance that the pedal arm 8 moves further from the fully closed position to the fully closed direction from time t4 to time t5 is shown as larger.

[0137] The behavior determination unit 16 determines that a rebound behavior has occurred if the pedal arm 8 has moved further in the closing direction from the fully closed position by a predetermined distance threshold Th_d or more. This is because if the impact force between the pedal arm 8 and the fully closed stopper 9 is large, the fully closed stopper 9 will significantly bend, subsequently causing a rebound behavior. Therefore, the behavior determination unit 16 determines whether the pedal arm 8 has significantly deflected the fully closed stopper 9 due to the impact force, that is, whether the pedal arm 8 has moved further in the closing direction from the fully closed position by a predetermined distance threshold Th_d or more. This allows the behavior determination unit 16 to determine whether a rebound behavior has occurred before it occurs.

[0138] In addition, in the signal processing device 3 of the sixth embodiment, the behavior determination unit 16 may also determine the size of the rebound behavior based on the sensor signal. Specifically, the greater the distance that the pedal arm 8 moves from the fully closed position in the closing direction, the greater the rebound behavior is determined by the behavior determination unit 16. In this case, the filter constant setting unit 18 described in the first embodiment may also be such that the larger the rebound behavior, the larger the "filter constant for bounce suppression" is set. Alternatively, the larger the rebound behavior, the longer the time for the filter constant setting unit 18 to apply the "filter constant for bounce suppression" to the filter circuit 17. In this case, the signal switching unit 20 described in the second embodiment may also be such that the larger the rebound behavior, the longer the time for outputting the fully closed signal.

[0139] (Seventh embodiment) like Figure 15 As shown, the brake pedal device 4 to which the signal processing device 3 of the seventh embodiment is applied includes a load sensor 21 for sensing whether a driver's pedal force is applied to the pedal arm 8 . A signal output from the load sensor 21 is transmitted to the signal processing device 3 .

[0140] Figure 16 The relationship between the sensor signal and the control signal under the pedal angle described in the upper part of the graph is the same as that referred to in the description of the first embodiment. Figure 4 The diagrams are substantially the same, so their description is omitted.

[0141] Figure 16 The line K in the lower part of the graph represents the signal output from the load sensor 21, that is, the load sensor value. When the load sensor value is less than the predetermined load threshold value Th_p, it indicates that the driver's pedal force is not applied to the pedal arm 8, that is, the driver's foot is off the pedal arm 8. Figure 16In the line K of the graph, the driver's pedal force is applied to the pedal arm 8 from time t1, and no pedal force is applied to the pedal arm 8 after time t3. That is, the driver starts the pedal arm 8 from time t1, presses the pedal arm 8 to the fully open position at time t2, and then removes the foot from the pedal arm 8 at time t3. Figure 16 As shown by the dashed line S in the upper portion of the graph, the pedal arm 8 rotates in the closing direction only by the force of the spring mechanism 10 after time t3, and collides with the fully closed stopper 9 at time t4, generating a rebound action.

[0142] Based on the output signal of the load sensor 21 and the sensor signal, the behavior determination unit 16 determines that a rebound behavior has occurred when the pedal arm 8 rotates in the closing direction and reaches the fully closed position while the driver's pedal force is not being applied to the pedal arm 8. This is because if the driver releases his foot from the pedal arm 8, the pedal arm 8 rotates in the closing direction solely due to the force of the spring mechanism 10, colliding with the fully closed stopper 9 in the fully closed position, thereby causing a rebound behavior. Therefore, the behavior determination unit 16 can determine whether a rebound behavior has occurred before the occurrence of a rebound behavior by determining whether the driver's pedal force is being applied to the pedal arm 8 when the pedal arm 8 rotates in the closing direction and reaches the fully closed position.

[0143] (Eighth Embodiment) The eighth embodiment has a different configuration of the brake pedal device 4 than the first to seventh embodiments. The other parts are the same as the first to seventh embodiments, so only the differences from the first to seventh embodiments will be described.

[0144] like Figure 17 As shown, the brake pedal device 4 to which the signal processing device 3 of the eighth embodiment is applied is a suspended-type pedal device. A suspended-type pedal device is a configuration in which all or most of the pedal tread 14, the portion of the pedal arm 8 to which the driver's pedal force is applied, is positioned below the rotation axis CL of the pedal arm 8 in the vertical direction when mounted on the vehicle (i.e., below the vehicle).

[0145] The housing 7 as a support body is fixed to the dash panel 23 or the like by bolts (not shown). The pedal arm 8 is supported so as to be rotatable relative to the housing 7. Figure 17 The dotted line 8a indicates that the pedal arm 8 is in contact with the fully open stopper 15 and the pedal arm 8 is in the fully open position. Figure 17 The solid line 8 b indicates a state in which the pedal arm 8 is in contact with the fully closed stopper 9 and the pedal arm 8 is located in the fully closed position.

[0146] Sensor 6 detects the pedal arm 8 or shaft 12 and outputs a sensor signal corresponding to the angle or stroke of the pedal arm 8. The sensor signal output by sensor 6 is transmitted to ECU 2. ECU 2 incorporates the signal processing device 3 described in the first through seventh embodiments. Furthermore, in the eighth embodiment, the signal processing device 3 is not limited to being incorporated into ECU 2; it may also be configured as an integrated circuit (IC) or ASIC integrated with sensor 6 included in brake pedal device 4.

[0147] The eighth embodiment described above can also achieve the same operational effects as those of the first to seventh embodiments.

[0148] (Other Implementation Methods) The present disclosure is not limited to the above-mentioned embodiments and can be appropriately changed. In addition, the above-mentioned embodiments are not unrelated to each other and can be appropriately combined except for cases where they are obviously not combinable. In addition, in the above-mentioned embodiments, the elements constituting the embodiments are not necessarily necessary, except for cases where they are specifically indicated as necessary and cases where they are obviously considered to be necessary in principle. In addition, in the above-mentioned embodiments, when referring to the number, value, amount, range and other numerical values ​​of the constituent elements of the embodiments, except for cases where they are specifically indicated as necessary and cases where they are clearly limited to a specific number in principle, they are not limited to the specific number. In addition, in the above-mentioned embodiments, when referring to the shape, positional relationship and the like of the constituent elements, etc., except for cases where they are specifically indicated as necessary and cases where they are clearly limited to a specific shape, positional relationship and the like in principle, they are not limited to the shape, positional relationship and the like.

[0149] The control unit and method thereof described in the present disclosure may also be implemented by a special-purpose computer, which is provided by a processor and a memory programmed to execute one or more functions embodied by a computer program. Alternatively, the control unit and method thereof described in the present disclosure may also be implemented by a special-purpose computer provided by a processor composed of one or more special-purpose hardware logic circuits. Alternatively, the control unit and method thereof described in the present disclosure may also be implemented by one or more special-purpose computers, which are composed of a combination of a processor and a memory programmed to execute one or more functions and a processor composed of one or more hardware logic circuits. In addition, the computer program may also be stored as instructions executed by a computer in a computer-readable non-transient tangible recording medium.

[0150] (The viewpoint of this disclosure) The present disclosure described above can be understood as, for example, the following viewpoints.

[0151] [First point of view] A signal processing device for processing a sensor signal output from a sensor of a brake pedal device (4), for use in a brake-by-wire system (1), wherein the brake pedal device comprises: A support body (7) is mounted on the vehicle; A pedal arm (8) is configured to be rotatable relative to the support body about a predetermined axis (CL), and is rotated in an opening direction by an increase in the pedaling force of the driver, and is rotated in a closing direction by a decrease or release of the pedaling force of the driver; a spring mechanism (10) for applying a force to the pedal arm that acts as a reaction force relative to the pedaling force of the driver; a fully closed stopper (9) for stopping the pedal arm at a fully closed position where the rotation of the pedal arm in the closing direction is restricted when the pedal arm is not subjected to the pedal force of the driver; and The sensor (6) outputs the sensor signal corresponding to the angle or stroke of the pedal arm, wherein The signal processing device comprises: A behavior determination unit (16) determines, based on the sensor signal, whether a rebound behavior will occur after the pedal arm rotates in the closing direction and reaches the fully closed position; a filter circuit (17) for performing smoothing processing on the sensor signal according to a filter constant to generate a control signal for braking the vehicle, wherein the larger the filter constant, the greater the control signal generated by the filter circuit for smoothing the change of the pulsating signal; and A filter constant setting unit (18) sets the filter constant when the behavior determination unit determines that the bounce behavior will occur to a larger value than the filter constant when the behavior determination unit determines that the bounce behavior will not occur.

[0152] [Second opinion] A signal processing device for processing a sensor signal output from a sensor of a brake pedal device, for use in a wire control brake system (1), wherein the brake pedal device comprises: A support body (7) is mounted on the vehicle; A pedal arm (8) is configured to be rotatable relative to the support body about a predetermined axis (CL), and is rotated in an opening direction by an increase in the pedaling force of the driver, and is rotated in a closing direction by a decrease or release of the pedaling force of the driver; a spring mechanism (10) for applying a force to the pedal arm that acts as a reaction force relative to the pedaling force of the driver; a fully closed stopper (9) for stopping the pedal arm at a fully closed position where the rotation of the pedal arm in the closing direction is restricted when the pedal arm is not subjected to the pedal force of the driver; and The sensor (6) outputs the sensor signal corresponding to the angle or stroke of the pedal arm, wherein The signal processing device comprises: a behavior determination unit (16) for determining, based on the sensor signal, whether a rebound behavior will occur after the pedal arm rotates in the closing direction and reaches the fully closed position; and A signal switching unit (20) switches a control signal for braking the vehicle to a signal value indicating that the pedal arm is at the fully closed position for a predetermined time and outputs the signal value when the behavior determination unit determines that the rebound behavior will occur.

[0153] [Third Viewpoint] The signal processing device according to the first or second aspect, wherein: The behavior determination unit calculates the movement speed of the pedal arm based on the differential value of the sensor signal, and determines that the rebound behavior will occur when the pedal arm rotates in the closing direction at a speed greater than a predetermined speed threshold (Th_v) or when the pedal arm reaches the fully closed position at a speed greater than the predetermined speed threshold.

[0154] [Fourth Viewpoint] The signal processing device according to any one of the first to third aspects, wherein: The behavior determination unit determines that the rebound behavior will occur when the time for which the pedal arm stays at the fully closed position or at a position closer to the closing direction than the fully closed position is shorter than a predetermined time threshold (Th_t).

[0155] [Fifth Viewpoint] The signal processing device according to any one of the first to fourth aspects, wherein: The behavior determination unit calculates acceleration of the pedal arm's movement based on a second-order differential value of the sensor signal, and determines that the rebound behavior will occur if an acceleration greater than or equal to a predetermined acceleration threshold value (Th_a) occurs while the pedal arm rotates in the closing direction until it reaches the fully closed position.

[0156] [Sixth Viewpoint] The signal processing device according to the fifth aspect, wherein: The predetermined acceleration threshold value is a fixed value, or a value uniquely determined according to the angle or stroke of the pedal arm based on the characteristics of the spring mechanism and the mass of the pedal arm.

[0157] [Seventh Viewpoint] The signal processing device according to any one of the first to sixth aspects, wherein: The behavior determination unit determines that the rebound behavior will occur when the pedal arm moves further in the closing direction from the fully closed position by a predetermined distance threshold (Th_d) or more.

[0158] [Eighth Viewpoint] The signal processing device according to any one of the first to seventh aspects, wherein: The brake pedal device further includes a load sensor (21) for sensing whether the pedal arm is subjected to the pedal force of the driver. The behavior determination unit determines that the rebound behavior will occur when the pedal arm rotates in the closing direction and reaches the fully closed position without the driver's pedaling force being applied to the pedal arm, based on the output signal of the load sensor and the sensor signal.

[0159] [Ninth Viewpoint] The signal processing device according to the first aspect, wherein: The behavior determination unit can determine the magnitude of the rebound behavior based on the sensor signal. The filter constant setting unit sets the filter constant to a larger value as the rebound behavior increases.

[0160] [Tenth Viewpoint] The signal processing device according to the first or ninth aspect, wherein: The behavior determination unit can determine the magnitude of the rebound behavior based on the sensor signal. The larger the bounce behavior, the longer the filter constant setting unit increases the time from setting the filter constant when the behavior determination unit determines that the bounce behavior will occur to restoring the filter constant to the filter constant when the behavior determination unit determines that the bounce behavior will not occur.

[0161] [Viewpoint 11] The signal processing device according to the second aspect, wherein: The behavior determination unit can determine the magnitude of the rebound behavior based on the sensor signal. The greater the rebound behavior, the longer the signal switching unit extends the specified time from switching the control signal for braking the vehicle to the signal value indicating that the pedal arm is in the fully closed position to restoring the control signal to the time when the behavior determination unit determines that the rebound behavior does not occur.

Claims

1. A signal processing device for processing a sensor signal output from a sensor of a brake pedal device (4), for use in a brake-by-wire system (1), wherein the brake pedal device comprises: A support body (7) is mounted on the vehicle; A pedal arm (8) is configured to be rotatable relative to the support body about a predetermined axis (CL), and is rotated in an opening direction by an increase in the pedaling force of the driver, and is rotated in a closing direction by a decrease or release of the pedaling force of the driver; a spring mechanism (10) for applying a force to the pedal arm that acts as a reaction force relative to the pedaling force of the driver; a fully closed stopper (9) for stopping the pedal arm at a fully closed position where the rotation of the pedal arm in the closing direction is restricted when the pedal arm is not subjected to the pedal force of the driver; and The sensor (6) outputs the sensor signal corresponding to the angle or stroke of the pedal arm, and is characterized in that: The signal processing device comprises: A behavior determination unit (16) determines, based on the sensor signal, whether a rebound behavior will occur after the pedal arm rotates in the closing direction and reaches the fully closed position; A filter circuit (17) performs smoothing processing on the sensor signal according to a filter constant to generate a control signal for braking the vehicle, wherein the larger the filter constant is, the greater the degree of smoothing of the sensor signal change is; as well as A filter constant setting unit (18) sets the filter constant when the behavior determination unit determines that the bounce behavior will occur to a larger value than the filter constant when the behavior determination unit determines that the bounce behavior will not occur.

2. A signal processing device for processing a sensor signal output from a sensor of a brake pedal device, for use in a brake-by-wire system (1), wherein the brake pedal device comprises: A support body (7) is mounted on the vehicle; A pedal arm (8) is configured to be rotatable relative to the support body about a predetermined axis (CL), and is rotated in an opening direction by an increase in the pedaling force of the driver, and is rotated in a closing direction by a decrease or release of the pedaling force of the driver; a spring mechanism (10) for applying a force to the pedal arm that acts as a reaction force relative to the pedaling force of the driver; a fully closed stopper (9) for stopping the pedal arm at a fully closed position where the rotation of the pedal arm in the closing direction is restricted when the pedal arm is not subjected to the pedal force of the driver; and The sensor (6) outputs the sensor signal corresponding to the angle or stroke of the pedal arm, and is characterized in that: The signal processing device comprises: A behavior determination unit (16) determines, based on the sensor signal, whether a rebound behavior will occur after the pedal arm rotates in the closing direction and reaches the fully closed position; as well as A signal switching unit (20) switches a control signal for braking the vehicle to a signal value indicating that the pedal arm is at the fully closed position for a predetermined time and outputs the signal value when the behavior determination unit determines that the rebound behavior will occur.

3. The signal processing device according to claim 1 or 2, characterized in that The behavior determination unit calculates the movement speed of the pedal arm based on the differential value of the sensor signal, and determines that the rebound behavior will occur when the pedal arm rotates in the closing direction at a speed greater than a predetermined speed threshold (Th_v) or when the pedal arm reaches the fully closed position at a speed greater than the predetermined speed threshold.

4. The signal processing device according to claim 1 or 2, characterized in that The behavior determination unit determines that the rebound behavior will occur when the time for which the pedal arm stays at the fully closed position or at a position closer to the closing direction than the fully closed position is shorter than a predetermined time threshold (Th_t).

5. The signal processing device according to claim 1 or 2, characterized in that: The behavior determination unit calculates acceleration of the pedal arm's movement based on a second-order differential value of the sensor signal, and determines that the rebound behavior will occur if an acceleration greater than or equal to a predetermined acceleration threshold value (Th_a) occurs while the pedal arm rotates in the closing direction until it reaches the fully closed position.

6. The signal processing device according to claim 5, characterized in that The predetermined acceleration threshold value is a fixed value, or a value uniquely determined according to the angle or stroke of the pedal arm based on the characteristics of the spring mechanism and the mass of the pedal arm.

7. The signal processing device according to claim 1 or 2, characterized in that: The behavior determination unit determines that the rebound behavior will occur when the pedal arm moves further in the closing direction from the fully closed position by a predetermined distance threshold (Th_d) or more.

8. The signal processing device according to claim 1 or 2, characterized in that: The brake pedal device further includes a load sensor (21) for sensing whether the pedal arm is subjected to the pedal force of the driver. The behavior determination unit determines that the rebound behavior will occur when the pedal arm rotates in the closing direction and reaches the fully closed position without the driver's pedaling force being applied to the pedal arm, based on the output signal of the load sensor and the sensor signal.

9. The signal processing device according to claim 1, wherein The behavior determination unit can determine the magnitude of the rebound behavior based on the sensor signal. The filter constant setting unit sets the filter constant to a larger value as the rebound behavior increases.

10. The signal processing device according to claim 1 or 9, characterized in that: The behavior determination unit can determine the magnitude of the rebound behavior based on the sensor signal. The larger the bounce behavior, the longer the filter constant setting unit increases the time from setting the filter constant when the behavior determination unit determines that the bounce behavior will occur to restoring the filter constant when the behavior determination unit determines that the bounce behavior will not occur.

11. The signal processing device according to claim 2, wherein: The behavior determination unit can determine the magnitude of the rebound behavior based on the sensor signal. The greater the rebound behavior, the longer the signal switching unit extends the specified time from switching the control signal for braking the vehicle to the signal value indicating that the pedal arm is in the fully closed position to restoring the control signal when the behavior determination unit determines that the rebound behavior does not occur.

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