Signal processing device

Abstract

A signal processing device (3) for processing a sensor signal output by a sensor (6) of a brake pedal device (4) comprises a behavior determination unit (16), a filter circuit (17), and a filter constant setting unit (18). The behavior determination unit (16) determines, based on the sensor signal, whether rebound behavior occurs after a pedal arm (8) has rotated in the closing direction and reached a fully closed position. The filter circuit (17) performs smoothing of the sensor signal according to a filter constant to generate a control signal for braking the vehicle, the degree of smoothing of the generated change in the sensor signal increasing with the size of the filter constant.The filter constant setting unit (18) sets the filter constant so that it is larger when the behavior determination unit (16) determines that the rebound behavior occurs than when the behavior determination unit (16) determines that the rebound behavior does not occur.

Description

Cross-reference to related registrations

[0001] The present application is based on Japanese patent application No. 2023-071628, which was filed on April 25, 2023, and whose description is hereby incorporated by reference. Technical field

[0002] The present disclosure relates to a signal processing device for use in a brake-by-wire system. background

[0003] In a conventional brake-by-wire system, an electronic control unit controls the vehicle's braking based on an electrical signal output from a brake pedal device mounted on the vehicle. Similarly, in a conventional accelerator-by-wire system, an electronic control unit controls the acceleration and deceleration of a vehicle based on an electrical signal output from an accelerator pedal device.

[0004] Patent document 1 describes an accelerator pedal device used in an accelerator-by-wire system. The accelerator pedal device includes a pedal arm that rotates in response to a force applied by the driver, a spring mechanism that exerts a reaction force against the force on the pedal arm, and two fully closed stoppers that stop the pedal arm in a fully closed position. The fully closed position is a position in which the rotation of the pedal arm is restricted when no pedal force is applied to the pedal arm by the driver and is referred to in patent document 1 as the rest position. Furthermore, the fully closed stopper is referred to in patent document 1 as a wait-stop stopper.The accelerator pedal assembly is equipped with two fully enclosed stoppers to suppress the collision noise that occurs when the pedal arm rotates vigorously due to the applied force of the spring mechanism and collides with the fully enclosed stopper when the driver removes his foot from the pedal arm. Document in the state of the art Patent document

[0005] Patent document 1: Japanese patent no. 4374180 Summary of the invention

[0006] However, if the driver removes their foot from the pedal arm and the force exerted by the spring mechanism, causing the pedal arm to collide with the fully closed stopper, is significant, the pedal arm may rebound from near the fully closed position. In this case, the sensor signal output by the accelerator pedal device sensor also oscillates near the fully closed position. If the electronic control unit controls the vehicle's acceleration / deceleration based on the sensor signal, the vehicle will accelerate or decelerate against the driver's intention to release the accelerator pedal, resulting in impaired drivability. This problem is not addressed in Patent Document 1. The issue of impaired drivability due to such pedal arm rebound behavior is not limited to accelerator-by-wire systems but can also occur in brake-by-wire systems.

[0007] In general, the force exerted by the spring mechanism in the brake pedal assembly used in a brake-by-wire system is greater than the force exerted by the spring mechanism in the accelerator pedal assembly. Therefore, when the driver releases their foot from a depressed position in the brake pedal assembly, the impact force upon contact of the pedal arm with the fully closed stop is greater than in an accelerator pedal assembly, and the rebound of the pedal arm is more pronounced. In this case, the sensor signal output by the brake pedal assembly also fluctuates considerably near the fully closed position. Consequently, when the electronic control unit applies the brakes based on this sensor signal, the vehicle decelerates against the driver's intention to release the brakes, resulting in impaired drivability.

[0008] Furthermore, in a brake-by-wire system, the number of unnecessary braking operations increases when the electronic control unit applies the brakes in response to a sensor signal that fluctuates according to the rebound behavior of the pedal arm. This can lead to problems such as accelerated brake pad wear. To address these issues, it is conceivable to set a large filter constant for a filter circuit that smooths the sensor signal output by a sensor in the signal processing unit used in the brake-by-wire system. However, if the filter constant is set to a large value and the driver presses and releases the pedal arm, the vehicle's braking response is delayed, resulting in a deterioration in drivability.To prevent the pedal arm from rebounding, it is also conceivable to increase the size of the fully closed stopper and physically absorb the impact force of the pedal arm. However, increasing the size of the fully closed stopper also increases the size of the brake pedal assembly, which raises concerns about increased manufacturing costs.

[0009] The objective 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.

[0010] According to one aspect of the present disclosure, a signal processing device is used in a brake-by-wire system and processes a sensor signal output by a sensor of a brake pedal device.

[0011] The brake pedal assembly comprises a support element, a pedal arm, a spring mechanism, a fully closed stop, and a sensor. The support element is mounted on a vehicle. The pedal arm is rotatable about a predetermined axis relative to the support element and rotates in the opening direction when the driver's pedal force increases and in the closing direction when the driver's pedal force decreases or is released. The spring mechanism applies a preload force to the pedal arm as a reaction force against the driver's pedal force. The fully closed stop stops the pedal arm in a fully closed position, restricting rotation of the pedal arm in the closing direction when no driver pedal force is applied. The sensor outputs a sensor signal corresponding to an angle or stroke of the pedal arm.

[0012] The signal processing device that processes the sensor signal comprises a behavior determination unit, a filter circuit, and a filter constant setting unit. Based on the sensor signal, the behavior determination unit determines whether rebound behavior will occur after the pedal arm has rotated in the closing direction and reached the fully closed position. The filter circuit performs smoothing of the sensor signal according to a filter constant to generate a control signal for braking the vehicle. The degree of smoothing of the resulting change in the sensor signal increases with the size of the filter constant. The filter constant setting unit adjusts the filter constant so that it is larger when the behavior determination unit determines that rebound behavior will occur than when the behavior determination unit determines that rebound behavior will not occur.

[0013] According to this configuration, the filter constant setting unit sets the filter constant to a large value when the behavior determination unit detects that rebound behavior will occur, and the filter circuit generates a control signal that significantly smooths the changes in the sensor signal. Even if the driver removes their foot from the pedal arm while it is depressed, and the pedal arm rebounds, the electronic control unit of the brake-by-wire system immediately releases the vehicle's braking force based on the control signal, in which the changes in the sensor signal have been significantly smoothed, thus improving drivability.

[0014] If, however, the behavior determination unit determines that no rebound behavior is occurring, the filter constant setting unit sets the filter constant to a value smaller than the value at which rebound behavior occurs, and the filter circuit generates a control signal that smooths the changes in the sensor signal to a small degree. Therefore, when the driver depresses and releases the pedal with their foot on the pedal arm, the electronic control unit of the brake-by-wire system initiates highly responsive braking based on a control signal with a low degree of smoothing of the changes in the sensor signal, thus improving drivability.

[0015] In addition, according to the signal processing of this signal processing device, the electronic control unit immediately releases the vehicle braking command even if the pedal arm springs back, so that there is no unnecessary increase in the number of vehicle braking operations and no unnecessary wear of the brake pads, etc.

[0016] Furthermore, according to the signal processing of this signal processing device, even with an increase in the preload force of the brake pedal spring mechanism, no enlargement of the fully enclosed stopper is required, which physically absorbs the collision force of the pedal arm, and drivability can be improved through control. Therefore, an increase in the size of the brake pedal device due to an enlargement of the fully enclosed stopper can be avoided, and manufacturing costs can be reduced.

[0017] According to another aspect of the present disclosure, a signal processing device is used in a brake-by-wire system and processes a sensor signal output by a sensor of a brake pedal device.

[0018] The brake pedal assembly comprises a support element, a pedal arm, a spring mechanism, a fully closed stop, and a sensor. The support element is mounted on a vehicle. The pedal arm is rotatable about a predetermined axis relative to the support element and rotates in the opening direction when the driver's pedal force increases and in the closing direction when the driver's pedal force decreases or is released. The spring mechanism applies a preload force to the pedal arm as a reaction force against the driver's pedal force. The fully closed stop stops the pedal arm in a fully closed position, restricting rotation of the pedal arm in the closing direction when no driver pedal force is applied. The sensor outputs a sensor signal corresponding to an angle or stroke of the pedal arm.

[0019] The signal processing device that processes the sensor signal includes a behavior determination unit and a signal switching unit. Based on the sensor signal, the behavior determination unit determines whether rebound behavior will occur after the pedal arm has rotated in the closing direction and reached the fully closed position. If the determination unit determines that rebound behavior will occur, the signal switching unit switches and outputs a control signal to brake the vehicle for a predetermined period, based on a signal value indicating that the pedal arm is in a fully closed position (hereinafter referred to as the "full-close signal").

[0020] According to this configuration, if the behavior determination unit detects that rebound behavior will occur, the signal switching unit switches the control signal to a full-closing signal for a predetermined period and outputs it. Even if the driver removes 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 a full-closing signal, thus improving drivability.

[0021] If, however, the behavior determination unit detects that the rebound behavior does not occur, the signal switching unit does not switch the control signal to the full-closing signal. Therefore, when the driver depresses and releases the pedal with their foot on the pedal arm, the electronic control unit of the brake-by-wire system initiates highly responsive vehicle braking based on the control signal or the sensor signal, which is processed in the normal manner, thus improving drivability.

[0022] In addition, according to the signal processing of the signal processing device, as described in another aspect of the present disclosure, there is no unnecessary increase in the number of operations for braking the vehicle, and unnecessary wear of the brake pads, etc., can be prevented.

[0023] Furthermore, according to the signal processing of the signal processing device, as described in another aspect of the present disclosure, there is no need to increase the size of the fully enclosed stopper, thus preventing the brake pedal device from becoming larger and reducing manufacturing costs.

[0024] The reference numbers given in parentheses, which are attached to the components and the like, provide an example of the correspondence between the components and the like and specific components and the like that are described in at least one of the embodiments described below. Brief description of the drawings Fig. Figure 1 is a schematic configuration diagram of a brake-by-wire system in which a signal processing device according to the first embodiment is used; Fig. Figure 2 is a block diagram of an electronic control unit containing the signal processing device according to the first embodiment; Fig. Figure 3 is a flowchart showing a control process performed by the signal processing device according to the first embodiment; Fig. Figure 4 is a graph showing a relationship between a sensor signal and a control signal in the signal processing device according to the first embodiment; Fig. Figure 5 is a graph showing a relationship between a sensor signal and a control signal in a signal processing device of a comparative example; Fig. Figure 6 is a block diagram of an electronic control unit that includes a signal processing device according to a second embodiment; Fig. Figure 7 is a block diagram of an electronic control unit containing the signal processing device according to the second embodiment; Fig. Figure 8 is a flowchart showing a control process performed by the signal processing device according to the second embodiment; Fig. Figure 9 is a graph showing the relationship between a sensor signal and a control signal in the signal processing device according to the second embodiment; Fig. Figure 10 is a graph showing a relationship between a sensor signal and a control signal and a movement speed of a pedal arm in a signal processing device according to the third embodiment; Fig. Figure 11 is a graph showing a relationship between a sensor signal and a control signal and a dwell time in the fully closed position of the pedal arm in a signal processing device according to the fourth embodiment; Fig. Figure 12 is a graph showing a relationship between a sensor signal and a control signal, a movement speed of a pedal arm and an acceleration of the movement of the pedal arm in a signal processing device according to a fifth embodiment; Fig. Figure 13 is a graph showing a relationship between the angle or stroke of the pedal arm and the force exerted on the pedal arm by the spring mechanism in the signal processing device according to the fifth embodiment; Fig. Figure 14 is a graph showing a relationship between a sensor signal and a control signal in a signal processing device according to a sixth embodiment; Fig. Figure 15 is a schematic configuration diagram of a brake-by-wire system in which a signal processing device according to a seventh embodiment is used; Fig. Figure 16 is a graph showing a relationship between a sensor signal and a control signal and an output value of a load sensor in the signal processing device according to the seventh embodiment; and Fig. Figure 17 is a schematic configuration diagram of a brake-by-wire system in which a signal processing device according to an eighth embodiment is used. Detailed description

[0025] Embodiments of the present disclosure are now described with reference to the drawings. Parts that are identical or equivalent in the following embodiments are assigned the same reference numerals and are not described. First embodiment:

[0026] A first embodiment is described with reference to the drawings. As in Fig. As shown in Figure 1, in the first embodiment a signal processing device 3 is integrated into a part of an electronic circuit of an electronic control unit 2, which is used in a brake-by-wire system 1 that performs the braking of a vehicle. Hereinafter, the electronic control unit 2 is referred to as "ECU 2". ECU is the abbreviation for "Electronic Control Unit". The signal processing device 3 is not limited to being integrated into the ECU 2, but can also be configured as an integrated circuit, such as an IC or ASIC, which is integrated into the sensor 6 provided in the brake pedal device 4.

[0027] First, a schematic configuration of the brake-by-wire system 1 is described.

[0028] As in Fig. As shown in Figure 1, the brake-by-wire system 1 comprises a brake pedal assembly 4, an ECU 2, a brake mechanism 5, and the like. The brake-by-wire system 1 is a system in which an ECU 2 controls the operation of a brake mechanism 5 based on a sensor signal output by a sensor 6 provided in the brake pedal assembly 4 to initiate vehicle braking. In particular, the brake-by-wire system 1, in which the signal processing device 3 of the first embodiment is used, is a complete brake-by-wire system in which components of the brake mechanism 5 (e.g., a master cylinder) and the brake pedal assembly 4 are not mechanically connected.

[0029] The brake pedal assembly 4 includes a housing 7 as a support element, a pedal arm 8, a fully enclosed stopper 9, a spring mechanism 10, a sensor 6 and the like. Fig. Figure 1 shows a cross-sectional view of the brake pedal assembly 4.

[0030] The housing 7 of the brake pedal assembly 4 is fixed to the vehicle with screws or the like (not shown).

[0031] In particular, the housing 7 is fixed to the floor 22 or to the dashboard in the vehicle interior. An interior space 11 is provided inside the housing 7. The interior space 11 accommodates the sensor 6, the spring mechanism 10, the shaft 12, and the like. The sensor 6 is positioned so that it overlaps the shaft 12 in its axial direction. Therefore, the shaft 12 is located on the reverse side of the paper surface of Fig. 1 is provided in relation to the sensor 6. The shaft 12 is provided to be rotatable about its own axis CL relative to the housing 7.

[0032] The pedal arm 8 is essentially plate-like and is fixed to the shaft 12 via a connecting element 13. One end of the connecting element 13 is fixed to the underside of the pedal arm 8, and the other end is fixed to the shaft 12. Therefore, the pedal arm 8 is designed to be rotatable about the axis CL of the shaft 12 relative to the housing 7.

[0033] The brake pedal assembly 4 of the first embodiment is an organ-type pedal assembly. An organ-type pedal assembly refers to a device configured such that all or most of the pedal tread 14, which is the part of the pedal arm 8 on which the driver's pedal force is exerted, is arranged vertically above the axis of rotation CL of the pedal arm 8 when mounted on the vehicle, i.e., above the vehicle. In the organ-type pedal assembly, the pedal arm 8 rotates in response to an increase in the pedal force exerted by the driver on the pedal arm 8 toward the floor 22 or the dashboard in the vehicle interior.

[0034] In the following description, the direction in which the pedal arm 8 rotates due to an increase in the pedal force exerted by the rider on the pedal arm 8 is referred to as the opening direction, and the direction in which the pedal arm 8 rotates due to a decrease or reduction in the pedal force exerted by the rider on the pedal arm 8 is referred to as the closing direction. The opening direction is referred to as the pedal pressure direction, and the closing direction is referred to as the pedal return direction.

[0035] The rotation of the pedal arm 8 in the opening direction is restricted by a fully open stopper 15. The fully open stopper 15 is a component that stops the pedal arm 8 in a fully open position, in which the rotation of the pedal arm 8 in the opening direction is restricted when the rider's pedal force is applied to the pedal arm 8. A dashed line 8a in Fig. Figure 1 indicates a state in which the pedal arm 8 and the fully open stopper 15 are in contact and the pedal arm 8 is in the fully open position. The fully open stopper 15 is preferably made of an elastic material such as rubber, resin, or silicone.

[0036] On the other hand, the rotation of the pedal arm 8 in the closing direction is restricted by a fully closed stopper 9. The fully closed stopper 9 is a component that stops the pedal arm 8 in a fully closed position, in which the rotation of the pedal arm 8 in the closing direction is restricted when the rider's pedal force is not applied to the pedal arm 8. A solid line 8b in Fig. Figure 1 indicates a state in which the pedal arm 8 and the fully closed stopper 9 are in contact and the pedal arm 8 is in the fully closed position. Incidentally, the fully closed stopper 9 is preferably also made of an elastic material such as rubber, resin, or silicone.

[0037] The spring mechanism 10 is configured to include one or more springs. The spring mechanism 10 generates a force that acts as a reaction force against the pedal force exerted by the driver on the pedal arm 8. By equipping the brake pedal assembly 4 with the spring mechanism 10, it is possible, even if the mechanical connection between the pedal arm 8 and the conventional master cylinder is eliminated, to achieve a reaction force similar to that achieved with a connected master cylinder, i.e., when the reaction force is generated by hydraulic pressure.

[0038] Sensor 6 detects pedal arm 8 or shaft 12 and outputs a sensor signal corresponding to the angle or stroke of pedal arm 8, since pedal arm 8 or shaft 12 is the detection target. Various types of sensors can be used as sensor 6, such as a magnetic sensor, an inductive sensor, an optical sensor, a load sensor, a rotary encoder, and a potentiometer. Sensor 6 does not necessarily have to be positioned at a location that overlaps the axis CL of shaft 12, but can also be positioned at a location that is away from the axis CL. The sensor signal output by sensor 6 is transmitted to the ECU. In this description, the sensor signal refers to the "raw sensor value" output by sensor 6.

[0039] The ECU 2 includes a microcontroller with a processor for performing control processing and arithmetic operations, as well as a memory unit, for example, a ROM and a RAM, for storing programs and data. The control unit also includes peripheral circuitry for these components. The memory unit comprises non-volatile physical storage media. Based on the programs stored in the memory unit, the ECU 2 performs various types of control processing and arithmetic operations to control the operation of devices connected to output ports of the ECU 2. In particular, the ECU 2 of the first embodiment includes the signal processing device 3 as part of its electronic circuitry. The signal processing device 3 processes sensor signals transmitted by the sensor 6 and the like and generates a control signal.The control circuit 24 of the ECU 2 controls the drive of the brake mechanism 5 on the basis of the control signal generated by the signal processing device 3.

[0040] Various mechanisms can be used as braking mechanism 5. For example, braking mechanism 5 can be an electric brake that applies braking to each wheel by driving an electric motor in response to a command from ECU 2 to press brake pads against a disc brake rotor. Alternatively, braking mechanism 5 can be configured, for example, to increase the hydraulic pressure of the brake fluid by actuating a master cylinder or hydraulic pump, thereby driving the wheel cylinders located at each wheel and actuating the brake pads. Additionally, braking mechanism 5 is also capable of performing normal control, ABS control, VSC control, etc., in response to commands from ECU 2. ABS stands for anti-lock braking system and VSC for vehicle stability control.

[0041] Next, the configuration of the signal processing device 3, which processes the sensor signal output by the sensor 6 of the brake pedal device 4, is described, with reference to Fig. 2.

[0042] As in Fig. As shown in Figure 2, the signal processing device 3 comprises a behavior determination unit 16, a filter circuit 17 and a filter constant setting unit 18 as functional blocks formed from electronic circuits.

[0043] The sensor signal output by sensor 6 is entered into the behavior determination unit 16 and the filter circuit 17.

[0044] The behavior determination unit 16 is a circuit that determines, based on the sensor signal, whether a rebound behavior occurs after the pedal arm 8 has rotated in the closing direction and reached its full position. The behavior determination unit 16 is configured to determine, before the rebound behavior occurs, whether or not a rebound behavior will occur. The specific method by which the behavior determination unit 16 determines whether or not the rebound behavior occurs is described in detail in the third to seventh embodiments described later.

[0045] Filter circuit 17 is a circuit that performs smoothing processing of the sensor signal according to a filter constant and generates a control signal for braking the vehicle. Filter circuit 17 generates a control signal that smooths changes in the sensor signal to a greater extent the larger the filter constant. Filter circuit 17 can be implemented using various techniques, such as a moving average filter or a low-pass filter. For example, if a moving average filter is used as filter circuit 17, the filter constant is the moving average time. Similarly, if a low-pass filter is used as filter circuit 17, the filter constant is a time constant.

[0046] The filter constant setting unit 18 is a circuit that sets a filter constant used in the filter circuit 17 based on the result of the determination by the behavior determination unit 16. The filter constant setting unit 18 sets the filter constant when the behavior determination unit 16 determines that the rebound behavior will be greater than the filter constant, and when the behavior determination unit 16 determines that the rebound behavior will not occur. More precisely, if the behavior determination unit 16 determines that rebound behavior will occur, the filter constant setting unit 18 sets the filter constant to a "rebound suppression filter constant." Conversely, if the behavior determination unit 16 determines that the rebound behavior will not occur, the filter constant setting unit 18 sets the filter constant to the "normal control filter constant."The “rebound suppression filter constant” is a value that is larger than the “normal control filter constant” and causes the filter circuit 17 to generate a control signal that smooths the changes in the sensor signal to a greater degree.

[0047] Next, the control process executed by the signal processing device 3 will be described with reference to the flowchart of Fig. 3 described. In the following explanation and drawings, a step is simply represented as "S".

[0048] In S10 of Fig. 3. Based on the sensor signal input from sensor 6, the behavior determination unit 16 determines whether there is a risk of rebound behavior occurring. That is, the behavior determination unit 16 determines whether rebound behavior occurs after the pedal arm 8 has rotated in the closing direction and reached the fully closed position, before the rebound behavior occurs.

[0049] If the behavior determination unit 16 in S10 detects a risk of rebound behavior, the process continues to S20. In S20, the filter constant setting unit 18 sets the filter constant to a "rebound suppression filter constant." As a result, the filter circuit 17 generates a control signal in which changes in the sensor signal are smoothed to a greater degree. The control circuit 24 of the ECU 2 controls the actuation 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 has reached the fully closed position, the control circuit 24 of the ECU 2 can immediately release the vehicle braking command to the brake mechanism 5.

[0050] If, however, the behavior determination unit 16 in S10 determines that there is no risk of rebound behavior occurring, the process continues with S30. In S30, the filter constant setting unit 18 sets the filter constant to the "filter constant for normal control". As a result, the filter circuit 17 generates a control signal in which the degree of smoothing of the change in the sensor signal is relatively low. The control circuit 24 of the ECU 2 controls the actuation of the brake mechanism 5 based on the control signal. Thus, if the driver presses and releases the pedal arm 8 with their foot, the control circuit 24 of the ECU 2 can perform a highly responsive vehicle braking action.

[0051] Next, the control process executed by signal processing unit 3 will be described with reference to the diagram in Fig. 4 described in relation to the relationship between the sensor signal and the control signal.

[0052] The horizontal axis of Fig. Number 4 indicates the time, and the vertical axis shows the angle of pedal arm 8, i.e., the pedal angle. On the vertical axis, "fully closed" is the angle at which pedal arm 8 is in the fully closed position and indicates a state in which the rider is not braking. Conversely, on the vertical axis, "fully open" is the angle at which pedal arm 8 is in the fully open position and indicates a state in which the rider is fully applying the brake. Fig. 4 The dashed dotted line S indicates the sensor signal and the solid line C indicates the control signal.

[0053] The dotted line S in Fig. The sensor signal displayed is a raw sensor value and indicates the actual angle of pedal arm 8. As indicated by the dashed dotted line S, the rider therefore begins to actuate pedal arm 8 at time t1, and pedal arm 8 begins to rotate from the fully closed position towards the opening direction. At time t2, pedal arm 8 reaches the fully open position. At time t3, the rider removes their foot from pedal arm 8, and pedal arm 8 begins to rotate from the fully open position towards the closing direction solely due to the preload force of the spring mechanism 10. At time t4, 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 due to the impact 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 elasticity. Therefore, the pedal arm 8 exhibits rebound behavior during the period from time t6 to time t9.

[0054] A solid line C in Fig. Figure 4 indicates a control signal generated by the filter circuit 17. From time t0 to t4, the behavior determination unit 16 determines that there is no risk of rebound behavior, and the filter constant setting unit 18 sets the filter constant to the "filter constant for normal control". As a result, the filter circuit 17 generates a control signal in which the degree of smoothing of the change in the sensor signal is relatively low. Therefore, during the period from time t1 to time t2, when the driver operates the pedal arm 8, the delay time Δα between the sensor signal and the control signal is short. When the pedal arm 8 is pressed, the control circuit 24 of the ECU 2 can therefore perform highly responsive vehicle braking.

[0055] If the behavior determination unit 16 determines that there is a risk of rebound behavior between times t3 and t4, the filter constant setting unit 18 sets the filter constant to a "rebound suppression filter constant" for a specific time period starting from time t4 (for example, between times t4 and t9). As a result, the filter circuit 17 generates a control signal in which changes in the sensor signal are smoothed to a greater degree. Therefore, even if the pedal arm 8 jumps between times t4 and t9, the control circuit 24 of the ECU 2 can immediately issue the vehicle braking command to the brake mechanism 5 based on the control signal.

[0056] At time t9, a certain amount of time has elapsed since time t4, and the filter constant setting unit 18 sets the filter constant to the "filter constant for normal control". If the driver starts to actuate the pedal arm 8 again after time t9, the control circuit 24 of the ECU 2 can consequently perform highly responsive vehicle braking.

[0057] For comparison with the control process of the first embodiment described above, the diagram in Fig. 5. A relationship between the sensor signal and the control signal in a signal processing device is described using a comparative example.

[0058] Although not shown in the figure, the signal processing device of the comparison example comprises only a filter circuit and no behavior determination unit 16 or filter constant setting unit 18.

[0059] The filter constant of the filter circuit of the comparison example is always set to a value that corresponds approximately to the “filter constant for rebound suppression” described in the first embodiment.

[0060] The dotted line S in Fig. The sensor signal specified in 5, i.e., the actual angle of the pedal arm 8, is the same as that described in the first embodiment.

[0061] The solid line C in Fig. The control signal specified in section 5 is generated by the filter circuit of the comparative example described above. During the period from time t1 to time t2, in which the driver operates the 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, the problem is that drivability deteriorates due to a delay in the response of the vehicle brakes when the pedal arm 8 is pressed.

[0062] In contrast, the signal processing device 3 of the first embodiment offers the following advantageous effects.

[0063] The signal processing unit 3 of the first embodiment comprises the behavior determination unit 16, the filter circuit 17, and the filter constant setting unit 18. The behavior determination unit 16 determines, based on the sensor signal, whether or not rebound behavior occurs in the pedal arm 8. The filter circuit 17 performs smoothing processing of the sensor signal according to a filter constant and generates a control signal. The filter constant setting unit 18 sets the filter constant higher when the behavior determination unit 16 determines that rebound behavior will occur than it does when the behavior determination unit 16 determines that rebound behavior will not occur.

[0064] According to this configuration, the filter constant setting unit 18 sets the filter constant to a large value when the behavior determination unit 16 detects that rebound behavior will occur, and the filter circuit 17 generates a control signal that significantly smooths the change in the sensor signal. Even if the driver releases their foot from the pedal arm 8 from the depressed position 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, in which the change in the sensor signal has been largely smoothed. Therefore, drivability can be improved.

[0065] If, however, the driver presses and releases pedal arm 8 while placing their foot on it, pedal arm 8 does not rotate in the closing direction and does not collide with the fully closed stopper 9 solely due to the preload force of the spring mechanism 10, and the behavior determination unit 16 determines that no rebound behavior occurs. Therefore, the filter constant setting unit 18 sets the filter constant to a value smaller than the value at which rebound behavior occurs, and the filter circuit 17 generates a control signal that smooths the changes in the sensor signal to a lesser degree. Thus, when the driver presses and releases pedal arm 8 with their foot on it, the control circuit 24 of the ECU 2 initiates highly responsive vehicle braking based on a control signal with a low degree of smoothing of the changes in the sensor signal, thereby improving drivability.

[0066] Furthermore, the control circuit 24 of the ECU 2, in accordance with the signal processing performed by the signal processing unit 3, immediately cancels the vehicle braking command to the brake mechanism 5 even if the pedal arm 8 exhibits rebound behavior. Therefore, there is no unnecessary increase in the number of vehicle braking operations, and unnecessary wear of the brake pads, etc., can be prevented.

[0067] Furthermore, according to the signal processing of the signal processing device 3, even if the preload force of the spring mechanism 10 provided in the brake pedal device 4 is increased, the size of the fully enclosed stopper 9, which physically absorbs the collision force of the pedal arm 8, does not need to be increased, and drivability can be improved by adjusting the controls. Therefore, an increase in the size of the brake pedal device 4 due to an increase in the size of the fully enclosed stopper 9 can be prevented, and manufacturing costs can be reduced.

[0068] In the signal processing device 3 of the first embodiment, the behavior determination unit 16 can determine the strength of the rebound behavior based on a sensor signal. In this case, the filter constant setting unit 18 can set the "rebound suppression filter constant" to a larger value as the rebound behavior increases. Furthermore, the filter constant setting unit 18 can lengthen the time for applying the "rebound suppression filter constant" to the filter circuit 17 as the rebound behavior increases. Specifically, the filter constant setting unit 18 can lengthen the time between when the "rebound suppression filter constant" is set and when the "normal control filter constant" is reset, as the rebound behavior increases. Second embodiment:

[0069] A second embodiment is described. In the second embodiment, the configuration of the signal processing device 3 and its control method are changed compared to the first embodiment, but other aspects are similar to those of the first embodiment, so only the parts that differ from the first embodiment are described.

[0070] As in Fig. As shown in Figure 6, the signal processing device 3 of the second embodiment comprises the behavior determination unit 16, the filter circuit 17, a full-closing signal generation unit 19 and a signal switching unit 20 as functional blocks formed from electronic circuits.

[0071] The sensor signal output by sensor 6 is entered into the behavior determination unit 16 and the filter circuit 17.

[0072] The behavior determination unit 16 is a circuit that determines, based on the sensor signal, whether a rebound behavior occurs after the pedal arm 8 has rotated in the closing direction and reached the fully closed position. The behavior determination unit 16 is configured to determine, before the rebound behavior occurs, whether or not a rebound behavior will occur. The specific method by which the behavior determination unit 16 determines whether or not the rebound behavior will occur is described in detail in the third to seventh embodiments described later.

[0073] The filter circuit 17 is a circuit that performs smoothing processing of the sensor signal according to a filter constant and generates a control signal for braking the vehicle. The filter circuit 17 can be implemented using various techniques, such as a moving average processing filter or a low-pass filter. In the second embodiment, the filter circuit 17 is not strictly necessary, and the signal processing device 3 can be configured without the filter circuit 17.

[0074] The full-closing signal generation unit 19 is a circuit that generates and outputs a full-closing signal. In this description, the full-closing signal refers to a signal value designated as the full-closing signal, indicating that the pedal arm 8 is in the fully closed position.

[0075] The signal switching unit 20 is a circuit that switches between the control signal generated by the filter circuit 17 and the full-closing signal generated by the full-closing signal generation unit 19, and outputs the switched signal based on the determination result of the behavior determination unit 16. If the behavior determination unit 16 determines that the rebound behavior does not occur, the signal switching unit 20 outputs a control signal generated by the filter circuit 17, as shown in Fig. 6 shown. If, however, the behavior determination unit 16 determines that the rebound behavior will occur, as in Fig. As shown in Figure 7, the signal switching unit 20 switches the control signal to the full closing signal generated by the full closing signal generation unit 19 and outputs it for a predetermined time.

[0076] Next, the control process performed by the signal processing unit 3 of the second embodiment will be described with reference to the flowchart of Fig. 8 described.

[0077] In S110 of Fig. Based on the sensor signal input from sensor 6, the behavior determination unit 16 determines whether there is a risk of rebound behavior occurring. That is, the behavior determination unit 16 determines whether rebound behavior will occur after the pedal arm 8 has rotated in the closing direction and reached the fully closed position, before the rebound behavior actually occurs.

[0078] If the behavior determination unit 16 in S110 detects a risk of rebound behavior, the process continues to S120. In S120, the signal switching unit 20 switches the control signal to the full-closing signal generated by the full-closing signal generation unit 19 and outputs the full-closing signal for a predetermined duration. As a result, the control circuit 24 of the ECU 2 controls the actuation of the brake mechanism 5 based on the full-closing signal. Even if the driver removes their foot from the pedal arm 8 and rebound behavior occurs after the pedal arm 8 has reached the fully closed position, the control circuit 24 of the ECU 2 can immediately release the vehicle braking command to the brake mechanism 5.

[0079] If, however, the behavior determination unit 16 in S110 determines that there is no risk of rebound behavior occurring, the process continues with S130. In S130, the signal switching unit 20 outputs the normal control signal generated by the filter circuit 17. If the signal processing unit 3 does not contain a 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 actuation of the brake mechanism 5 based on the control signal or the sensor signal. Thus, if the driver presses and releases the pedal arm 8 with their foot, the control circuit 24 of the ECU 2 can initiate highly responsive vehicle braking.

[0080] Next, the control process executed by the signal processing unit 3 will be described with reference to a diagram in Fig. 9 describes the relationship between the sensor signal, the control signal and the full closing signal.

[0081] The dotted line S in Fig. The sensor signal specified in 9, i.e. the actual angle of the pedal arm 8, is the same as that described in the first embodiment.

[0082] A solid line C in Fig. Figure 9 shows the control signal and the full-closing signal output by the signal switching unit 20. From time t0 to t4, the behavior determination unit 16 determines that there is no risk of rebound behavior, and the signal switching unit 20 outputs a normal control signal generated by the filter circuit 17. Therefore, during the period from time t1 to time t2, when the driver operates the pedal arm 8, the delay time Δα between the sensor signal and the control signal is very short. When the pedal arm 8 is operated, the control circuit 24 of the ECU 2 can therefore initiate highly responsive vehicle braking.

[0083] If the behavior determination unit 16 determines that there is a risk of rebound behavior between times t3 and t4, the signal switching unit 20 switches the control signal to the full-closing signal generated by the full-closing signal generation unit 19 and outputs it for a predetermined period starting from time t4 (for example, between times t4 and t9). Therefore, even if the pedal arm 8 bounces or rebounds 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 full-closing signal.

[0084] At time t9, which is a certain time after time t4, the signal switching unit 20 switches to the normal control signal generated by the filter circuit 17 and outputs it. As a result, if the driver starts to actuate the pedal arm 8 again after time t9, the control circuit 24 of the ECU 2 can therefore perform a highly responsive vehicle braking action.

[0085] The signal processing device 3 of the second embodiment described above provides the following advantageous effects.

[0086] The signal processing unit 3 of the second embodiment comprises the behavior determination unit 16 and the signal switching unit 20. Based on the sensor signal, the behavior determination unit 16 determines whether rebound behavior occurs in the pedal arm 8. If the behavior determination unit 16 determines that rebound behavior will occur, the signal switching unit 20 switches the control signal to a fully closed signal for a predetermined period and outputs it.

[0087] According to this configuration, when the behavior determination unit 16 detects that rebound behavior will occur, the signal switching unit 20 switches the control signal to a full-closing signal and outputs it for a predetermined period. Even if the driver removes their foot from the pedal arm 8 while operating it, causing the pedal arm 8 to rebound, the control circuit 24 of the ECU 2 immediately releases the vehicle braking command to the brake mechanism 5 based on the full-closing signal, thereby improving drivability.

[0088] If, however, the driver presses and releases pedal arm 8 while placing their foot on it, pedal arm 8 does not rotate in the closing direction and does not collide with the fully closed stopper 9 solely due to the preload force of the spring mechanism 10, and the behavior determination unit 16 determines that no rebound behavior occurs. Therefore, the signal switching unit 20 does not switch the control signal to a fully closed signal. Consequently, when the driver presses and releases pedal arm 8 with their foot on it, the control circuit 24 of the ECU 2 performs highly responsive vehicle braking based on the control signal, which is normally derived from the sensor signal, thereby improving drivability.

[0089] Furthermore, according to the signal processing of the signal processing device 3, as in the first embodiment, there is no unnecessary increase in the number of operations for braking the vehicle, and unnecessary wear of the brake pads and the like can be prevented.

[0090] Furthermore, according to the signal processing of the signal processing device 3, as in the first embodiment, no enlargement of the fully closed stopper 9 is required, thus preventing an enlargement of the brake pedal device 4 and reducing manufacturing costs.

[0091] In the signal processing unit 3 of the second embodiment, the behavior determination unit 16 can determine the strength of the rebound behavior based on a sensor signal. In this case, the signal switching unit 20 can output a full-closing signal for a longer period if the rebound behavior increases. Specifically, the signal switching unit 20 can extend the time from switching from the normal control signal generated by the filter circuit 17 to the full-closing signal generated by the full-closing signal generation unit 19 until switching back to the normal control signal generated by the filter circuit 17, depending on the strength of the rebound behavior. Third to seventh embodiments:

[0092] In contrast, the third to seventh embodiments describe a specific method in which the behavior determination unit 16 determines whether or not rebound behavior will occur. In the descriptions of the third to seventh embodiments, the signal processing device 3 is described similarly to the first embodiment, comprising the behavior determination unit 16, the filter circuit 17, and the filter constant setting unit 18. However, without being limited to this, the signal processing device 3 in the descriptions of the third to seventh embodiments may also be equipped, as in the second embodiment, with the behavior determination unit 16, the filter circuit 17, the full-closing signal generation unit 19, and the signal switching unit 20. Third embodiment:

[0093] The relationship between the sensor signal and the control signal in the upper part of the graph in Fig. The pedal angle shown in section 10 is essentially the same as in the diagram in Fig. 4, which is referenced in the description of the first embodiment, and therefore a description of it is omitted. Additionally, the signal processing device 3 of the third embodiment is capable of outputting a control signal that is considered fully closed when the sensor signal is less than a value indicating the fully closed state. In particular, the signal processing device 3 can be located in the upper part of the graph in Fig. 10. Between times t4 and t6 and between times t8 and t9, output a control signal that is considered to be fully closed. This configuration also applies to the first and second embodiments described above, as well as to the fourth through seventh embodiments described below.

[0094] A line V in the lower part of the diagram in Fig. Figure 10 indicates the movement speed of the pedal arm 8. The behavior determination unit 16, included in the signal processing unit 3 of the third embodiment, is able to calculate the movement speed of the pedal arm 8 from the difference value of the sensor signal. The behavior determination unit 16 then determines that a rebound behavior occurs when the pedal arm 8 rotates in the closing direction at a speed equal to or greater than a predetermined speed threshold Th_v, or when the pedal arm 8 reaches the fully closed position at a speed equal to or greater than a predetermined speed threshold Th_v.

[0095] The predetermined velocity threshold Th_v is determined by tests or the like, depending on the pressure force characteristic of the spring mechanism 10 included in the brake pedal device 4, and is stored in advance in the memory of the signal processing device 3. The memory is a non-volatile material storage medium. A velocity equal to or greater than the predetermined velocity threshold Th_v means a velocity that, as an absolute value, is equal to or greater than the predetermined velocity threshold Th_v, regardless of the direction in which the pedal arm 8 moves.

[0096] In the third embodiment described above, the behavior determination unit 16 determines that a rebound behavior occurs when the pedal arm 8 rotates in the closing direction at a speed equal to or greater than a predetermined speed threshold Th_v, or when the pedal arm 8 reaches the fully closed position at a speed equal to or greater than a predetermined speed threshold Th_v.

[0097] According to this configuration, when the rider removes their foot from the pedal arm 8, the pedal arm 8 rotates in the closing direction solely due to the preload force of the spring mechanism 10 at a speed equal to or greater than a predetermined speed threshold Th_v. If it collides with the fully closed stopper 9 in the fully closed position, a rebound behavior occurs. Therefore, before the rebound behavior occurs, the behavior determination unit 16 can determine whether or not a rebound behavior will occur by calculating the speed of movement as the pedal arm 8 rotates in the closing direction from the difference value of the sensor signal.

[0098] In the signal processing unit 3 of the third embodiment, the behavior determination unit 16 can determine the magnitude of the rebound behavior based on a sensor signal. Specifically, the behavior determination unit 16 determines that the rebound behavior is greater the higher the speed at which the pedal arm 8 rotates in the closing direction. In this case, the filter constant setting unit 18 described in the first embodiment can adjust the "rebound suppression filter constant" to a larger value as the rebound behavior increases. Furthermore, the filter constant setting unit 18 can increase the duration for applying the "rebound 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 can output a full closing signal for a longer period of time with increasing rebound behavior. Fourth embodiment:

[0099] The relationship between the sensor signal and the control signal in the upper part of the graph in Fig. The pedal angle shown in Figure 11 is essentially the same as in the graph in Fig. 4, which is referred to in the description of the first embodiment, and therefore a description of it is omitted.

[0100] A line I in the lower part of the graph in Fig. 11 displays a count value for the time during which the pedal arm 8 is in the fully closed position and in a position further in the closing direction than the fully closed position. The behavior determination unit 16 provided in the signal processing unit 3 of the fourth embodiment has a counter circuit that counts the time during which the pedal arm 8 is in the fully closed position and in a position further in the closing direction than the fully closed position, and is capable of counting this time. In particular, the vertical axis in the lower part of the graph represents Fig. Figure 11 represents the count value obtained by counting the time that the pedal arm 8 is in the fully closed position and further in the closing direction than the fully closed position. When the pedal arm 8 moves from the fully closed position in the opening direction, the count value is reset. In line I of the graph in Fig. 11 the count is reset at time t1, the counting starts at time t4 and the count is reset at time t6.

[0101] The behavior determination unit 16 determines that a rebound behavior occurs when the time the pedal arm 8 remains in the fully closed position and in a position further in the closing direction than the fully closed position (i.e., the counter value) is less than a predetermined time limit Th_t. The time limit Th_t is set to a time shorter than the time (e.g., 0.25 seconds) a person would need to pivot the pedal arm 8 several times with their foot at maximum speed and is pre-stored in the memory of the signal processing device 3.

[0102] In the fourth embodiment described above, the behavior determination unit 16 determines that the rebound behavior occurs when the time during which the pedal arm 8 remains in the fully closed position or in a position further in the closing direction than the fully closed position is shorter than a predetermined time limit Th_t.

[0103] According to this configuration, when the pedal arm 8 rotates in the closing direction solely due to the preload force of the spring mechanism 10 and collides with the full-closing stopper 9, it only briefly impacts the full-closing stopper 9, preventing a person from operating it with their foot at maximum speed, and then exhibits a rebound behavior. Therefore, the behavior determination unit 16 can determine whether or not the rebound behavior will occur before it does by recording the time the pedal arm 8 remains in the fully closed position and in a position further in the closing direction than the fully closed position.

[0104] In the signal processing unit 3 of the fourth embodiment, the behavior determination unit 16 can determine the magnitude of the rebound behavior based on a sensor signal. Specifically, the behavior determination unit 16 determines that the shorter the time the pedal arm 8 remains in the fully closed position and in a position further in the closing direction than the fully closed position, the greater the rebound behavior. In this case, the filter constant setting unit 18 described in the first embodiment can set the "rebound suppression filter constant" to a larger value as the rebound behavior increases. Furthermore, the filter constant setting unit 18 can set the duration for applying the "rebound suppression filter constant" to the filter circuit 17 to be longer as the rebound behavior increases.In this case, the signal switching unit 20 described in the second embodiment can output a full closing signal for a longer period of time if the rebound behavior is increased. Fifth embodiment:

[0105] The relationship between the sensor signal and the control signal in the upper part of the diagram in Fig. The pedal angle shown in section 12 is essentially the same as in the diagram in Fig. 4, which is referenced in the description of the first embodiment, and therefore a description of it is omitted. A line V in the middle part of the diagram in Fig. 12 represents the speed of movement of the pedal arm 8, and since this line essentially corresponds to line V in the lower part of the diagram in Fig. Since it corresponds to point 10, which is referenced in the explanation of the third embodiment, a description of it is omitted.

[0106] A line G in the lower part of the diagram in Fig. 12 indicates an acceleration of the movement of the pedal arm 8. The behavior determination unit 16, contained in the signal processing unit 3 of the fifth embodiment, is able to calculate the acceleration of the movement of the pedal arm 8 from the second-order differential of the sensor signal. The behavior determination unit 16 then determines that a rebound behavior occurs when the pedal arm 8 rotates in the closing direction with an acceleration equal to or greater than a predetermined acceleration threshold Th_a, or when the pedal arm 8 reaches the fully closed position with an acceleration equal to or greater than a predetermined acceleration threshold Th_a.The acceleration equal to or greater than the predetermined acceleration threshold Th_a means an acceleration whose absolute value is equal to or greater than the predetermined acceleration threshold Th_a, regardless of the direction in which the pedal arm 8 moves. Furthermore, the predetermined acceleration threshold Th_a is either a constant value or a value uniquely determined according to the angle or stroke of the pedal arm 8, based on the properties of the spring mechanism 10 and the mass of the pedal arm 8.

[0107] Fig. Figure 13 is a diagram showing the relationship between the angle θ or stroke of the pedal arm 8 and the preload force F(θ) exerted on the pedal arm 8 by the spring 10. This diagram is defined during the design of the spring mechanism 10 and is referred to as the pedal force characteristic of the spring mechanism 10. A solid line D in the diagram of Fig. Figure 13 shows the relationship between the angle θ or the stroke of the pedal arm 8 and the preload force F(θ) exerted by the spring mechanism 10 on the pedal arm 8 when the pedal arm 8 rotates in the opening direction. Furthermore, the dashed dotted line E indicates the ratio between the angle θ or the stroke of the pedal arm 8 and the preload force F(θ) exerted by the spring mechanism 10 on the pedal arm 8 when the pedal arm 8 rotates in the closing direction.

[0108] When the pedal arm 8 rotates in the closing direction, the preload force F(θ) acting on the pedal arm 8 by the spring 10 at a predetermined angle θ, the acceleration a at this predetermined angle θ and the mass m of the pedal arm 8 have the following relationship, which is expressed by equation 1 from the equation of motion. F(θ)=ma

[0109] From the above equation 1 it follows that when the pedal arm 8 rotates in the closing direction, the acceleration a at a predetermined angle θ has the relationship of the following equation 2. a=F(θ) / m

[0110] As described above, the preload force F(θ) acting on the pedal arm 8 from the spring mechanism 10 at a predetermined angle θ has a value that is defined at the time of construction as the pedal force characteristic of the spring mechanism 10.

[0111] If the pedal arm 8 rotates in the closing direction and the acceleration a at a predetermined angle θ is less than the value obtained by dividing the preload force F(θ) specified during construction at the predetermined angle θ by the mass m of the pedal arm 8, it is assumed that the rider's foot is on the pedal arm 8. In this case, no rebound movement occurs after the pedal arm 8 strikes the full-closing stopper 9.

[0112] If, however, the pedal arm 8 rotates in the closing direction, the following can be assumed in a case where the acceleration a at a predetermined angle θ corresponds to the value obtained by dividing the spring force F(θ) specified at the time of construction for this predetermined angle θ by the mass m of the pedal arm 8. In other words, in this case, the rider's foot is not placed on the pedal arm 8, and the pedal arm 8 rotates in the closing direction only due to the preload force of the spring of the spring mechanism 10, so that a rebound behavior can be assumed to occur after the impact of the pedal arm 8 on the full-closing stopper 9.Incidentally, the statement "the acceleration a at a predetermined angle θ corresponds to the value obtained by dividing the preload force F(θ) specified at the time of construction at the predetermined angle θ by the mass m of the pedal arm 8" is intended to acknowledge that the acceleration a is slightly reduced due to the friction of the shaft 12, etc., the air resistance of the pedal arm 8, etc. Therefore, by setting the specified acceleration threshold Th_a to a value uniquely determined according to the angle or stroke of the pedal arm 8 based on the properties of the spring mechanism 10 and the mass m of the pedal arm 8, it can be precisely determined whether or not rebound behavior occurs.The predetermined acceleration threshold Th_a can be determined experimentally and is a value that is uniquely determined, including an error, with respect to the acceleration level required to cause rebound behavior.

[0113] Furthermore, if the pedal arm 8 rotates with an acceleration greater than a certain constant value, the rebound behavior occurs after the pedal arm 8 has collided with the full-closing stopper 9, so that it is also possible to set the specified acceleration threshold Th_a to a certain constant value.

[0114] In the fifth embodiment described above, the behavior determination unit 16 determines that the rebound behavior occurs when an acceleration equal to or greater than a predetermined acceleration threshold Th_a occurs while the pedal arm 8 rotates in the closing direction and reaches the fully closed position.

[0115] According to this configuration, when the rider removes their foot from the pedal arm 8, it rotates in the closing direction with an acceleration equal to or greater than a predetermined acceleration caused solely by the preload force of the spring mechanism 10. When it collides with the full-closing stopper 9 in the fully closed position, the rebound behavior occurs. Therefore, the behavior determination unit 16 can determine whether or not rebound behavior will occur before it occurs by calculating the acceleration of the pedal arm 8 from the second-order differential of the sensor signal.

[0116] Furthermore, in the fifth embodiment, the predetermined acceleration threshold Th_a, which is used by the behavior determination unit 16 to determine the rebound behavior, is either a constant value or a value that is uniquely determined depending on the angle or stroke of the pedal arm 8, based on the properties of the spring 10 and the mass m of the pedal arm 8. According to this configuration, the behavior determination unit 16 can accurately determine whether or not rebound behavior occurs.

[0117] In the signal processing unit 3 of the fifth embodiment, the behavior determination unit 16 can determine the magnitude of the rebound behavior based on a sensor signal. Specifically, the behavior determination unit 16 determines that the greater the acceleration of the pedal arm 8 as it rotates toward full closure, the greater the rebound behavior. In this case, the filter constant setting unit 18 described in the first embodiment can set the "rebound suppression filter constant" to a larger value as the rebound behavior increases. Furthermore, the filter constant setting unit 18 can increase the duration for applying the "rebound 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 can output a full closing signal for a longer period of time if the rebound behavior is increased. Sixth embodiment:

[0118] The relationship between the sensor signal and the control signal in the diagram in Fig. The pedal angle shown in section 14 is essentially the same as in the diagram in Fig. 4, which is referenced in the description of the first embodiment, and therefore a description of it is omitted. In the diagram in Fig. Figure 14 is an exaggerated representation of the distance traveled by the pedal arm 8 from the fully closed position towards full closure from time t4 to time t5, for the sake of simplicity.

[0119] The behavior determination unit 16 determines that rebound behavior occurs when the pedal arm 8 moves a distance Th_d or more in the closing direction from the fully closed position. This is because a large impact force between the pedal arm 8 and the full-closing stopper 9 causes the full-closing stopper 9 to deflect significantly, resulting in rebound behavior. Therefore, the behavior determination unit 16 determines whether the pedal arm 8 has deflected the full-closing stopper 9 significantly due to the collision force, i.e., whether the pedal arm 8 has moved a distance Th_d or more in the closing direction from the fully closed position. In this way, the behavior determination unit 16 can determine whether or not rebound behavior will occur before it does.

[0120] In the signal processing unit 3 of the sixth embodiment, the behavior determination unit 16 can determine the magnitude of the rebound behavior based on a sensor signal. Specifically, the behavior determination unit 16 determines that the greater the distance by which the pedal arm 8 has risen in the closing direction from the fully closed position, the greater the rebound behavior. In this case, the filter constant setting unit 18 described in the first embodiment can set the "rebound suppression filter constant" to a larger value as the rebound behavior increases. Furthermore, the filter constant setting unit 18 can increase the duration for applying the "rebound 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 can output a full closing signal for a longer period of time if the rebound behavior is increased. Seventh embodiment:

[0121] As in Fig. As shown in Figure 15, the brake pedal device 4, for which the signal processing device 3 of the seventh embodiment is used, is provided with a load sensor 21 that detects whether the driver's pedal force is exerted on the pedal arm 8 or not. The signal output by the load sensor 21 is transmitted to the signal processing device 3.

[0122] The relationship between the sensor signal and the control signal in the upper part of the diagram in Fig. The pedal angle shown in Figure 16 is essentially the same as in the diagram in Fig. 4, which is referred to in the description of the first embodiment, and therefore a description of it is omitted.

[0123] A line K in the lower part of the diagram in Fig. 16 indicates the value output by load sensor 21, i.e., the load sensor value. If the load sensor value is equal to or less than a predetermined load threshold Th_p, this indicates a state in which no pedal force is exerted by the rider on pedal arm 8, i.e., a state in which the rider's foot is not on pedal arm 8. In line K of the diagram in Fig. 16. The rider's pedal force is applied to pedal arm 8 from time t1 onwards, and from time t3 onwards, no pedal force is applied to pedal arm 8. That is, the rider begins to actuate pedal arm 8 at time t1, pushes pedal arm 8 to the fully open position at time t2, and then removes their foot from pedal arm 8 at time t3. Therefore, pedal arm 8 rotates as shown by the dotted line S in the upper part of the diagram. Fig. 16 shows that after time t3 only the preload force of the spring mechanism 10 in the closing direction occurs, and after the impact on the full-closing stopper 9 at time t4 the rebound behavior occurs.

[0124] Based on the output signal from the load sensor 21 and the sensor signal, the behavior determination unit 16 determines that the rebound behavior occurs when the pedal arm 8 rotates in the closing direction and reaches the fully closed position without the rider applying pedal force to the pedal arm 8. This is because, when the rider removes their foot from the pedal arm 8, the pedal arm 8 rotates in the closing direction solely due to the preload force of the spring mechanism 10 and, in the fully closed position, collides with the full-closing stopper 9, resulting in the rebound behavior. Therefore, as the pedal arm 8 rotates in the closing direction and reaches the fully closed position, the behavior determination unit 16 can determine whether or not the rebound behavior will occur, depending on whether or not the rider applies pedal force to the pedal arm 8. Eighth embodiment:

[0125] The eighth embodiment differs from the first to seventh embodiments in that the configuration of the brake pedal device 4 is changed, but is otherwise similar to the first to seventh embodiments, so that only the parts that differ from the first to seventh embodiments are described.

[0126] As in Fig. Figure 17 shows a brake pedal device 4 for which a signal processing device 3 of the eighth embodiment is applied, a suspended pedal device. The suspended pedal device is a device in which all or most of the pedal tread surface 14, which is the part of the pedal arm 8 on which the driver's pedal force acts, is positioned downwards in a vertical direction (i.e., below the vehicle) with respect to the axis of rotation CL of the pedal arm 8 when it is attached to the vehicle.

[0127] The housing 7, which serves as a mount, is attached to a dashboard 23 or the like by screws or the like (not shown). The pedal arm 8 is rotatably mounted relative to the housing 7. A dashed line 8a in Fig. Figure 17 indicates a state in which the pedal arm 8 and the full-opening stopper 15 are in contact and the pedal arm 8 is in the fully open position. A solid line 8b in Fig. 17 indicates a state in which the pedal arm 8 and the full-closing stopper 9 are in contact and the pedal arm 8 is in the fully closed position.

[0128] The sensor 6 detects the pedal arm 8 or the shaft 12 and outputs a sensor signal according to the angle or stroke of the pedal arm 8, since the pedal arm 8 or the shaft 12 is the detection target. The sensor signal output by the sensor 6 is transmitted to the ECU. The ECU 2 comprises the signal processing device 3 described in the first to seventh embodiments. In the configuration of the eighth embodiment, the signal processing device 3 is not limited to being integrated into the ECU 2, but can be configured as an integrated circuit, such as an IC or ASIC, which is integrated into the sensor 6 provided in the brake pedal assembly 4.

[0129] The eighth embodiment described above can also achieve the same effects as the first to seventh embodiments. Other embodiments:

[0130] The present disclosure is not limited to the embodiments described above and may be modified accordingly. The embodiments described above are not independent of one another and may be combined accordingly, unless the combination is obviously impossible. The components of each of the embodiments described above are not necessarily essential, unless it is specifically stated that the components are essential in the embodiment described above, or unless the components are obviously essential in principle.A quantity, value, size, area, or the like referred to in the description of the embodiments described above is not necessarily limited to a specific value, size, area, or the like, unless it is expressly described as essential or is generally understood to be essential. Furthermore, a shape, positional relationship, or the like of a structural element referred to in the embodiments described above is not limited to such a shape, positional relationship, or the like, unless specifically described or obviously necessary to be generally limited.

[0131] The control unit and method described in this disclosure are implemented by a dedicated computer, which is provided by configuring a processor and memory programmed to perform one or more functions executed by a computer program. Alternatively, the control unit and method described in this disclosure can be implemented by a special-purpose computer configured as a processor with one or more special-purpose hardware logic circuits. Alternatively, the control unit and method described in this disclosure can be implemented by one or more special-purpose computers configured as a combination of a processor and memory programmed to perform one or more functions, and a processor configured with one or more hardware logic circuits.Computer programs can be stored as instructions to be executed by a computer in a tangible, non-volatile, computer-readable medium. Various aspects of the present revelation:

[0132] The present revelation described above can be understood, for example, by the following characteristics. Aspect 1:

[0133] A signal processing device for processing a sensor signal from a brake pedal device (4) used in a brake-by-wire system (1), wherein the brake pedal device contains a support element attached to a vehicle (7), a pedal arm (8) configured to be rotatable about a predetermined axis (CL) relative to the support element and to rotate in an opening direction when the rider's pedal force is increased, and to rotate in a closing direction when the rider's pedal force is decreased or released, a spring (10) configured to exert a preload force on the pedal arm as a reaction force against the rider's pedal force a full-closing stopper (9) configured to stop the pedal arm in a fully closed position, in which rotation of the pedal arm in the closing direction is restricted when no pedal force is applied to the pedal arm by the rider, and a sensor (6) configured to output a sensor signal corresponding to an angle or stroke of the pedal arm, the signal processing device contains a behavior determination unit (16) configured to determine, based on the sensor signal, whether a rebound behavior occurs after the pedal arm has rotated in the closing direction and reached the fully closed position, a filter circuit (17) configured to perform the smoothing processing of the sensor signal in accordance with a filter constant to generate a control signal for braking the vehicle, wherein the filter circuit generates the control signal with a greater degree of smoothing of the change in the sensor signal when the filter constant is increased, and a filter constant setting unit (18) configured to set the filter constant to a value when the behavior determination unit determines that rebound behavior occurs, which is greater than the filter constant when the behavior determination unit determines that rebound behavior does not occur. Aspect 2:

[0134] Signal processing device for processing a sensor signal from a brake pedal device (4) used in a brake-by-wire system (1), wherein the brake pedal device includes a support element (7) that is attached to a vehicle, a pedal arm (8) configured to be rotatable about a predetermined axis (CL) relative to the support element and to rotate in an opening direction when the rider's pedal force is increased, and to rotate in a closing direction when the rider's pedal force is decreased or released, a spring (10) configured to exert a preload force on the pedal arm as a reaction force against the rider's pedal force a full-closing stopper (9) configured to stop the pedal arm in a fully closed position, in which rotation of the pedal arm in the closing direction is restricted, when no pedal force is applied to the pedal arm by the rider, and a sensor (6) configured to output a sensor signal corresponding to an angle or stroke of the pedal arm, the signal processing device contains a behavior determination unit (16) configured to determine, based on the sensor signal, whether a rebound behavior occurs after the pedal arm has rotated in the closing direction and reached the fully closed position, and a signal switching unit (20) configured to switch a control signal for braking the vehicle to a signal value indicating that the pedal arm has been in the fully closed position for a predetermined period of time and to output this signal when the behavior determination unit determines that the rebound behavior is occurring. Aspect 3:

[0135] In the signal processing device according to aspect 1 or 2, the behavior determination unit calculates an operating speed of the pedal arm from a difference value of the sensor signal and determines that the rebound behavior occurs when the pedal arm rotates in the closing direction at a speed equal to or greater than a predetermined speed threshold (Th_v) or when the pedal arm reaches the fully closed position at a speed equal to or greater than the predetermined speed threshold. Aspect 4:

[0136] In the signal processing device according to one of aspects 1 to 3, the behavior determination unit determines that the rebound behavior occurs when the time during which the pedal arm remains in the fully closed position and in a position further in the closing direction than the fully closed position is shorter than a predetermined time limit (Th_t). Aspect 5:

[0137] In the signal processing device according to one of aspects 1 to 4, the behavior determination unit calculates an acceleration with which the pedal operates from a second-order differential value of the sensor signal and determines that the rebound behavior occurs when, between the time at which the pedal arm rotates in the closing direction and the time at which it reaches the fully closed position, an acceleration occurs which is equal to or greater than a predetermined acceleration threshold (Th_a). Aspect 6:

[0138] In the signal processing device according to aspect 5, the predetermined acceleration threshold is a constant value or a value that is uniquely determined according to an angle or stroke of the pedal arm based on a property of the spring mechanism and a mass of the pedal arm. Aspect 7:

[0139] In the signal processing device according to one of aspects 1 to 6, the behavior determination unit determines that the rebound behavior occurs when the pedal arm moves by a predetermined distance threshold (Th_d) or more in the closing direction from the fully closed position. Aspect 8:

[0140] In the signal processing device according to one of aspects 1 to 7, the brake pedal device includes a load sensor (21) configured to detect whether the driver's pedal force is applied to the pedal arm, and based on an output signal from the load sensor and the sensor signal, the behavior determination unit determines that the rebound behavior occurs when the pedal arm rotates in the closing direction and reaches the fully closed position while the driver's pedal force is not applied to the pedal arm. Aspect 9:

[0141] In the signal processing unit according to aspect 1, the behavior determination unit determines a magnitude of the rebound behavior based on the sensor signal, and the filter constant setting unit adjusts the filter constant to a larger value when the rebound behavior increases. Aspect 10:

[0142] In the signal processing device according to one of aspects 1 to 9, the behavior determination unit determines a magnitude of the rebound behavior based on the sensor signal, and The filter constant setting unit increases the time from when the behavior determination unit sets the filter constant when it determines that rebound behavior occurs, until when it resets to the filter constant when the behavior determination unit determines that rebound behavior does not occur; the higher the rebound behavior, the greater the increase. Aspect 11:

[0143] In the signal processing device according to aspect 2, the behavior determination unit determines a magnitude of the rebound behavior based on the sensor signal, and the signal switching unit increases a predetermined time from the time at which the control signal to brake the vehicle is switched to the signal value indicating that the pedal arm is in the fully closed position, until the time at which the behavior determination unit resets the control signal to the value when it is determined that the rebound behavior will not occur, with the rebound behavior being greater the higher the rebound behavior. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2023-071628

[0001] JP 4374180

[0005]

Claims

[1] Signal processing device for processing a sensor signal from a brake pedal device (4) used in a brake-by-wire system (1), wherein the brake pedal device includes a support element to be attached to a vehicle (7), a pedal arm (8) configured to be rotatable about a predetermined axis (CL) relative to the support element and to rotate in an opening direction when the rider's pedal force is increased, and to rotate in a closing direction when the rider's pedal force is decreased or released, a spring (10) configured to exert a preload force on the pedal arm as a reaction force against the rider's pedal force, a full-closing stopper (9) configured to stop the pedal arm in a fully closed position in which rotation of the pedal arm in the closing direction is restricted when no pedal force is applied to the pedal arm by the rider, and a sensor (6) configured to output a sensor signal corresponding to an angle or stroke of the pedal arm, wherein the signal processing device includes: a behavior determination unit (16) configured to determine, based on the sensor signal, whether a rebound behavior occurs after the pedal arm has rotated in the closing direction and reached the fully closed position; a filter circuit (17) configured to process the sensor signal in accordance with a filter constant to generate a control signal for braking the vehicle, wherein the filter circuit generates the control signal with a greater degree of smoothing of a change in the sensor signal when the filter constant is increased; and a filter constant setting unit (18) that is configured to set the filter constant, when the behavior determination unit determines that the rebound behavior occurs, to a value greater than the filter constant when the behavior determination unit determines that the rebound behavior does not occur. [2] Signal processing device for processing a sensor signal from a brake pedal device (4) used in a brake-by-wire system (1), wherein the brake pedal device includes a support element to be attached to a vehicle (7), a pedal arm (8) configured to be rotatable about a predetermined axis (CL) relative to the support element and to rotate in an opening direction when the rider's pedal force is increased, and to rotate in a closing direction when the rider's pedal force is decreased or released, a spring (10) configured to exert a preload force on the pedal arm as a reaction force against the rider's pedal force, a full-closing stopper (9) configured to stop the pedal arm in a fully closed position in which rotation of the pedal arm in the closing direction is restricted when no pedal force is applied to the pedal arm by the rider, and a sensor (6) configured to output a sensor signal corresponding to an angle or stroke of the pedal arm, wherein the signal processing device, features: a behavior determination unit (16) configured to determine, based on the sensor signal, whether rebound behavior occurs after the pedal arm has rotated in the closing direction and reached the fully closed position; and a signal switching unit (20) configured to determine that the rebound behavior occurs and to switch and output a control signal for controlling the vehicle to a signal value indicating that the pedal arm is in the fully closed position for a predetermined period of time. [3] Signal processing device according to claim 1 or 2, wherein the behavior determination unit calculates an operating speed of the pedal arm from a difference value of the sensor signal and determines that the rebound behavior occurs when the pedal arm rotates in the closing direction at a speed equal to or greater than a predetermined speed threshold (Th_v) or when the pedal arm reaches the fully closed position at a speed equal to or greater than the predetermined speed threshold. [4] Signal processing device according to claim 1 or 2, wherein the behavior determination unit determines that the rebound behavior occurs when a time during which the pedal arm remains in the fully closed position and in a position further in the closing direction than the fully closed position is shorter than a predetermined time limit (Th_t). [5] Signal processing device according to claim 1 or 2, wherein the behavior determination unit calculates an operational acceleration of the pedal arm from a second-order differential value of the sensor signal and determines that the rebound behavior occurs when, between the time at which the pedal arm rotates in the closing direction and the time at which it reaches the fully closed position, an acceleration occurs which is equal to or greater than a predetermined acceleration threshold (Th_a). [6] Signal processing device according to claim 5, wherein the predetermined acceleration threshold is a constant value or a value that is uniquely determined according to an angle or stroke of the pedal arm based on a property of the spring mechanism and a mass of the pedal arm. [7] Signal processing device according to claim 1 or 2, wherein the behavior determination unit determines that the rebound behavior occurs when the pedal arm moves by a predetermined distance (Th_d) or more in the closing direction from the fully closed position. [8] Signal processing device according to claim 1 or 2, wherein the brake pedal device includes a load sensor (21) configured to detect whether the driver's pedal force is being applied to the pedal arm, and The behavior determination unit, based on an output signal from the load sensor and the sensor signal, determines that the rebound behavior occurs when the pedal arm rotates in the closing direction and reaches the fully closed position while the rider's pedal force is not being applied to the pedal arm. [9] Signal processing device according to claim 1, wherein the behavior determination unit determines a magnitude of the rebound behavior based on the sensor signal, and the filter constant setting unit sets the filter constant to a larger value when the rebound behavior increases. [10] Signal processing device according to claim 1 or 9, wherein the behavior determination unit determines a measure of the rebound behavior based on the sensor signal and The filter constant setting unit increases the time from when the behavior determination unit sets the filter constant when it determines that the rebound behavior occurs, until when it resets the filter constant when the behavior determination unit determines that the rebound behavior does not occur, the greater the rebound behavior. [11] Signal processing device according to claim 2, wherein The behavior determination unit determines a measure of the rebound behavior based on the sensor signal, and The signal switching unit increases a predetermined time from the moment the control signal for braking the vehicle is switched to the signal value indicating that the pedal arm is in the fully closed position, until the moment the behavior determination unit resets the control signal to the value when it is determined that the rebound behavior will not occur, the greater the rebound behavior.

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