Brake device and vehicle

Abstract

To provide a technique capable of executing appropriate brake assist according to a rider's brake operation.SOLUTION: A brake device for a vehicle having a master cylinder and a brake caliper includes a modulator having a main flow path for allowing brake fluid to flow from the master cylinder to the brake caliper, a sub flow path for allowing the brake fluid to flow back from the brake caliper to the main flow path, and a supply flow path for supplying the brake fluid from the main flow path to the sub flow path, a first detection means for detecting a cylinder pressure which is a pressure of the brake fluid in the master cylinder, a second detection means for detecting a caliper pressure which is a pressure of the brake fluid in the brake caliper, and a control means for determining an operation state of the modulator based on a detection value of the cylinder pressure by the first detection means and a detection value of the caliper pressure by the second detection means, and controlling brake assist by the modulator according to a determination result.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to vehicle braking technology. [Background technology]

[0002] In recent years, efforts to provide access to sustainable transport systems that take into consideration vulnerable transport participants have been gaining momentum. To achieve this, we are focusing on research and development into driver assistance technologies to further improve road safety and convenience.

[0003] Patent Document 1 describes a brake system that controls the braking force of a saddle-riding vehicle using a braking mechanism (a so-called reflux modulator) that includes a main flow path for circulating brake fluid in a master cylinder to a wheel cylinder, a secondary flow path for releasing brake fluid from the wheel cylinder, and a supply flow path for supplying brake fluid from the master cylinder to the secondary flow path. When the brake system determines based on the detected value of the master cylinder pressure that the rider is applying the brakes, it executes a driving assistance mode (a so-called brake assist) that amplifies the braking force of the saddle-riding vehicle. Furthermore, when the detected value of the master cylinder pressure becomes lower than a reference pressure, it determines that the brake operation has been released, and ends the driving assistance mode. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2023 / 007428 Summary of the Invention [Problem to be solved by the invention]

[0005] In a return-flow modulator with a main flow path, a secondary flow path, and a supply flow path, situations can arise in which the rider's brake operation does not match the detected master cylinder pressure. For example, when pressure assist is being performed, brake fluid from the master cylinder flows into the secondary flow path via the supply flow path, which can cause the detected master cylinder pressure to be lower than the value corresponding to the brake operation. Also, when the antilock brake system (ABS) is operating, brake fluid flows into the master cylinder, which can cause the detected master cylinder pressure to be higher than the value corresponding to the brake operation. In such cases, it can be difficult to provide appropriate brake assist in response to the rider's brake operation.

[0006] Therefore, an object of the present invention is to provide a technology that can execute appropriate brake assist in response to the rider's braking operation, thereby contributing to the development of a sustainable transportation system. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, one aspect of the present invention provides a brake device for a vehicle having a master cylinder and a brake caliper, the brake device having a main flow path for flowing brake fluid from the master cylinder to the brake caliper, a secondary flow path for returning the brake fluid from the brake caliper to the main flow path, and a supply flow path for supplying the brake fluid from the main flow path to the secondary flow path, and characterized in that it comprises: a modulator that controls the flow of the brake fluid in the main flow path, the secondary flow path, and the supply flow path using a plurality of valves; a first detection means that detects a cylinder pressure, which is the pressure of the brake fluid in the master cylinder; a second detection means that detects a caliper pressure, which is the pressure of the brake fluid in the brake caliper; and a control means that determines the operating status of the modulator based on the detection value of the cylinder pressure by the first detection means and the detection value of the caliper pressure by the second detection means, and controls brake assist by the modulator in accordance with the determination result. [Effects of the Invention]

[0008] According to the present invention, for example, it is possible to provide a technique that can execute appropriate brake assist in accordance with the brake operation of the rider. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a side view of a saddle-ride type vehicle according to a first embodiment; [Figure 2] FIG. 1 is a schematic diagram showing an example of the configuration of a front wheel brake device in a first embodiment; [Figure 3] Control block diagram of a brake device in the first embodiment [Figure 4] 1 is a flowchart showing a control method for a brake device according to a first embodiment; [Figure 5] 1 is a flowchart showing a control method for a brake device according to a first embodiment; [Figure 6] 1 is a flowchart showing a control method for a brake device according to a first embodiment; [Figure 7] A diagram showing the normal operating conditions of a hydraulic modulator. [Figure 8] A diagram showing the operating status during pressure assistance in the hydraulic modulator. [Figure 9] A diagram showing the operating status of the hydraulic modulator during ABS pressure reduction [Figure 10] FIG. 6 is a diagram illustrating steps S114 to S117 in the flowchart of FIG. 5. [Figure 11] A diagram showing the relationship between vehicle speed and assist gain [Figure 12] 10 is a flowchart showing a control method for a brake device according to a second embodiment. [Figure 13] 10 is a flowchart showing a control method for a brake device according to a second embodiment. [Figure 14] Flowchart showing release determination in the third embodiment [Figure 15] FIG. 15 is a diagram for explaining steps S301 to S307 in the flowchart of FIG. 14. [Figure 16]FIG. 10 is a diagram for explaining another example of release determination in the third embodiment; [Figure 17] 10 is a waveform graph showing the results of filtering processing in the fourth embodiment. [Figure 18] Comparison of multiple filtering processing results with no processing DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the following embodiments, and includes modifications and variations of the configuration within the scope of the present invention. Furthermore, not all of the combinations of features described in the present embodiments are necessarily essential to the present invention. Note that the same reference numerals are used to designate the same components, and their description will be omitted.

[0011] First Embodiment A first embodiment of the present invention will be described. Fig. 1 is a side view of a saddle-ride type vehicle 100 (hereinafter sometimes simply referred to as vehicle 100) according to this embodiment. Vehicle 100 is a motorcycle equipped with one front wheel FW and one rear wheel RW. Note that the present invention is not limited to saddle-ride type vehicles, and can also be applied to other types of vehicles, such as four-wheeled vehicles.

[0012] The vehicle 100 includes a body frame 101 that forms its skeleton. The body frame 101 rotatably supports a front wheel steering unit 102 at its front end, and swingably supports a swing arm 115 at its rear end. The front wheel steering unit 102 includes a pair of left and right front forks 103 that support the front wheels FW, and a steering handlebar 104 attached to the upper parts of the pair of front forks 103. A right grip 105 of the steering handlebar 104 is an accelerator grip that allows a rider (operator) to instruct the acceleration of the vehicle 100. A brake lever 106 that accepts a brake operation by the rider on the front wheel FW is rotatably provided near the right grip 105. The swing arm 115 is swingably supported at its front end by the body frame 101, and supports the rear wheel RW at its rear end.

[0013] An internal combustion engine 107 and a transmission 108 supported by the body frame 101 are disposed in the region between the front wheel FW and the rear wheel RW. The output of the internal combustion engine 107 is transmitted to the rear wheel RW via the transmission 108 and a chain transmission mechanism (not shown). As described above, this embodiment uses a chain drive mechanism, but a shaft drive mechanism or a belt drive mechanism may also be used. Also, a fuel tank 109 is disposed above the internal combustion engine 107. A seat 110 on which a rider sits is disposed behind the fuel tank 109. Note that while the vehicle 100 of this embodiment is a vehicle using the internal combustion engine 107 as a drive source, the present invention is not limited thereto and may be an electric vehicle using an electric motor as a drive source. In this case, the drive force may be transmitted directly from an electric motor mounted in the wheel to the wheel.

[0014] The brake mechanism 111 is a mechanism that applies a braking force to the front wheel FW. In this embodiment, an example will be described in which a disc brake is used as the brake mechanism 111. The brake mechanism 111 includes a brake rotor 112 that rotates coaxially with the front wheel FW, and a brake caliper 113 that has brake pads (not shown). The brake caliper 113 is supported by the front fork 103, and clamps the brake rotor 112 with the brake pads to brake the front wheel FW that rotates integrally with the brake rotor 112. The clamping force of the brake caliper 113 (i.e., the braking force of the front wheel FW) can be generated in accordance with the amount of brake operation by the rider on the brake lever 106. In addition, a wheel speed sensor 114 that detects the amount of rotation of the front wheel FW is provided on the front fork 103.

[0015] The brake mechanism 116 is a mechanism that applies a braking force to the rear wheel RW. In this embodiment, an example will be described in which a disc brake is used as the brake mechanism 116. The brake mechanism 116 includes a brake rotor 117 that rotates coaxially with the rear wheel RW and a brake caliper 118 that has brake pads (not shown). The brake caliper 118 is supported by the swing arm 115, and clamps the brake rotor 117 with the brake pads to brake the rear wheel RW that rotates integrally with the brake rotor 117. The clamping force of the brake caliper 118 (i.e., the braking force of the rear wheel RW) can be generated in accordance with the amount of braking operation of the brake pedal 119 by the rider. In addition, a wheel speed sensor 120 that detects the amount of rotation of the rear wheel RW is provided below the swing arm 115.

[0016] The inertial sensor 121 includes, for example, an inertial measurement unit (IMU) and detects the acceleration and angular velocity occurring in the vehicle 100 (vehicle body). Specifically, the inertial sensor 121 detects the acceleration of the vehicle 100 in each of the longitudinal direction, the transverse direction, and the vertical direction, and detects the angular velocity of the vehicle 100 in each of the roll direction, the pitch direction, and the yaw direction. Here, in the present embodiment, an example using the inertial sensor 121 will be described, but sensors for detecting the acceleration and / or angular velocity in each direction may be provided separately. Furthermore, sensors for detecting the speed of the vehicle 100 in each of the longitudinal direction, the transverse direction, and the vertical direction may be provided, and sensors for detecting the angle of the vehicle 100 in each of the roll direction, the pitch direction, and the yaw direction may be provided.

[0017] [Brake system configuration] FIG. 2 is a schematic diagram showing an example configuration of a brake device 130 (brake system) for the front wheel FW. The brake device 130 for the front wheel FW includes a hydraulic circuit 1 that supplies hydraulic pressure of brake fluid (hydraulic fluid) generated in accordance with the amount of braking operation of the brake lever 106 by the rider to a brake caliper 113 of a brake mechanism 111. The brake caliper 113 clamps a brake rotor 112 with brake pads (not shown) by the hydraulic pressure of the brake fluid supplied by the hydraulic circuit 1, thereby generating a braking force for the front wheel FW. Hereinafter, the brake device 130 for the front wheel FW will be described, but the brake device 130 can be applied not only to the front wheel FW but also to the rear wheel RW. When the brake device 130 is applied to the rear wheel RW, the brake device 130 (hydraulic circuit 1) supplies hydraulic pressure of brake fluid (hydraulic fluid) generated in accordance with the amount of braking operation of the brake pedal 119 by the rider to a brake caliper 118 of the brake mechanism 116. The braking device 130 may be provided for only one of the front wheels FW and the rear wheels RW. That is, the braking device 130 may be provided for at least one of the front wheels FW and the rear wheels RW.

[0018] The hydraulic circuit 1 includes a master cylinder 2. The master cylinder 2 converts the amount of operation of the brake lever 106 into hydraulic pressure of the brake fluid by supplying brake fluid stored in a reservoir 3 to a flow path 1a in accordance with the amount of operation of the brake lever 106. When the hydraulic pressure of the brake fluid generated in the master cylinder 2 is transmitted to a brake caliper 113, a brake rotor 112 is clamped by the brake pads of the brake caliper 113, and a braking force is generated on the front wheels FW.

[0019] In the brake device 130 of this embodiment, when an emergency brake operation for suddenly stopping the vehicle 100 is input to the brake lever 106 by the rider, a pressurization assist is performed to increase the braking force of the front wheel FW by increasing the hydraulic pressure of the brake fluid applied to the brake caliper 113. Furthermore, when the antilock brake system (ABS) is in operation, a depressurization assist may be performed to decrease the braking force of the front wheel FW by reducing the hydraulic pressure of the brake fluid supplied to the brake caliper 113. In order to perform such brake assists as pressurization assist and depressurization assist, the brake device 130 of this embodiment is provided with a return-flow type hydraulic pressure modulator 6 and a control unit 7 that controls the brake assist by the hydraulic pressure modulator 6.

[0020] The hydraulic pressure modulator 6 includes a plurality of solenoid valves 10-13 (valves) whose operation is controlled by the control unit 7, and a motor 15. The solenoid valves 10 and 12 are normally open solenoid valves, and the solenoid valves 11 and 13 are normally closed solenoid valves. The brake fluid flow path 1a branches into a flow path 1b and a flow path 1c at a branch point b1. The flow path 1b is connected to a brake caliper 113.

[0021] Solenoid valves 10 and 12 are provided in flow path 1b to open and close flow path 1b. Solenoid valve 12 is arranged in flow path 1b closer to the brake caliper 113 than solenoid valve 10. Solenoid valve 11 is provided in flow path 1c to open and close flow path 1c.

[0022] Flow path 1c branches into flow paths 1d and 1e at branch point b2. Flow path 1d connects branch point b2 with a portion of flow path 1b between solenoid valve 10 and solenoid valve 12. Flow path 1d is provided with a pump 14 driven by a motor 15. The output port of pump 14 is located on the flow path 1b side, and the input port of pump 14 is located on the branch point b2 side. When motor 15 is driven, brake fluid is pumped by pump 14 in the direction of branch point b2 → flow path 1d → flow path 1b. Meanwhile, flow path 1e connects branch point b2 with a portion of flow path 1b between solenoid valve 12 and brake caliper 113.

[0023] The solenoid valve 13 is provided in the flow path 1e and opens and closes the flow path 1e. A check valve 16 and a reservoir 17 are provided in the flow path 1e between the solenoid valve 13 and the branch point b2. The check valve 16 is configured to allow the flow of brake fluid in the direction from the solenoid valve 13 to the pump 14, while restricting the flow of brake fluid in the opposite direction. The reservoir 17 is connected between the solenoid valve 13 and the check valve 16 and is configured to be able to store brake fluid. In this embodiment, the reservoir 17 is an accumulator.

[0024] A hydraulic pressure sensor 8 is provided in flow path 1c, detecting the hydraulic pressure of the brake fluid in flow path 1c between branch point b1 and solenoid valve 11. The hydraulic pressure sensor 8 may be understood as a sensor (first detection unit) that detects the master cylinder pressure, which is the pressure of the brake fluid in master cylinder 2. Hereinafter, the hydraulic pressure sensor 8 may be referred to as the "M / C pressure sensor 8," and the master cylinder pressure detected by the M / C pressure sensor 8 may be referred to as the "M / C detected value." Furthermore, flow path 1b is provided with a hydraulic pressure sensor 9 that detects the hydraulic pressure of the brake fluid in flow path 1b between solenoid valve 12 and brake caliper 113. The hydraulic pressure sensor 9 may be understood as a sensor (second detection unit) that detects the brake caliper pressure, which is the pressure of the brake fluid in brake caliper 113. Hereinafter, the hydraulic pressure sensor 9 may be referred to as the "CAL pressure sensor 9," and the brake caliper pressure detected by the CAL pressure sensor 9 may be referred to as the "CAL detected value."

[0025] In the hydraulic modulator 6 configured as described above, flow paths 1a and 1b form a main flow path for flowing brake fluid from the master cylinder 2 to the brake caliper 113. Furthermore, flow paths 1d and 1e form a secondary flow path for returning (returning) the brake fluid from the brake caliper 113 to the main flow path (flow path 1b). Flow path 1c forms a supply flow path for supplying brake fluid from the main flow path (flow path 1a) to the secondary flow paths (flow paths 1d, 1e). The flow of brake fluid in these main flow path, secondary flow path, and supply flow path is controlled by driving a plurality of solenoid valves 10-13 and a motor 15 (pump 14).

[0026] [Brake system control block diagram] FIG. 3 is a control block diagram of the brake device 130. The control unit 7 includes a processing unit 71, a storage unit 72 such as a RAM or a ROM, and an interface unit 73 that relays transmission and reception of signals to and from external devices. The processing unit 71 is a processor typified by a CPU, and controls the hydraulic pressure modulator 6 by executing programs stored in the storage unit 72. The storage unit 72 stores various data in addition to the programs executed by the processing unit 71. The interface unit 73 receives detection results from the M / C pressure sensor 8, the CAL pressure sensor 9, the wheel speed sensors 114 and 120, and the inertia sensor 121 via a signal processing circuit (not shown). Based on these detection results, the processing unit 71 controls the driving of the solenoid valves 10 to 13 and the motor 15 using a drive circuit (not shown). The control unit 7 (processing unit 71) may be configured as an ECU (Electronic Control Unit) mounted on the vehicle 100.

[0027] In a conventional hydraulic pressure modulator 6 of a return type, brake assist is controlled based on the master cylinder pressure (M / C detection value) detected by the M / C pressure sensor 8. However, with the hydraulic pressure modulator 6, situations can arise in which the rider's brake operation does not match the M / C detection value. For example, when pressurization assist is being performed, brake fluid from the master cylinder 2 flows into the secondary flow path (flow path 1d) via the supply flow path (flow path 1c), which can cause the M / C detection value to be lower than the value corresponding to the rider's brake operation. Furthermore, when depressurization assist is being performed while the ABS is activated, brake fluid returns to the main flow path (flow path 1a) via the secondary flow paths (flow paths 1d and 1e), which can cause the M / C detection value to be higher than the value corresponding to the rider's brake operation. In such a case, if the brake assist by the hydraulic pressure modulator 6 is controlled based only on the M / C detection value, it can be difficult to provide appropriate brake assist in accordance with the rider's intended brake operation.

[0028] Therefore, in the brake device 130 of this embodiment, the operating condition of the hydraulic pressure modulator 6 is determined based on the M / C detection value and the CAL detection value, and the brake assist by the hydraulic pressure modulator 6 is controlled in accordance with the determination result. Specifically, the brake operation amount intended by the rider is estimated based on the determination result of the operating condition of the hydraulic pressure modulator 6, and the brake assist by the hydraulic pressure modulator 6 is controlled in accordance with the estimated value (hereinafter, sometimes referred to as an operation estimated value). The control unit 7 of this embodiment is provided with a setting unit 74 that determines the operating condition of the hydraulic pressure modulator 6 and sets the operation estimated value in accordance with the determination result. The setting unit 74 can be configured by a processor (e.g., an ECU) different from the processing unit 71.

[0029] [Example of braking device operation] 4 to 6 are flowcharts showing a control method for the brake device 130 in this embodiment. The flowcharts of FIGS. 4 to 6 can be executed by the control unit 7. Specifically, the flowcharts of FIGS. 4 to 5 are executed by the setting unit 74, and the flowchart of FIG. 6 is executed by the processing unit 71. In addition, the flowcharts of FIGS. 4 to 6 can be executed repeatedly. The flowcharts of FIGS. 4 to 5 and the flowchart of FIG. 6 may be executed separately in parallel.

[0030] In step S101, the setting unit 74 determines whether or not there is a deviation between the master cylinder pressure (M / C detection value) detected by the M / C pressure sensor 8 and the brake caliper pressure (CAL detection value) detected by the CAL pressure sensor 9. For example, if the difference between the M / C detection value and the CAL detection value is within a specified range, the setting unit 74 determines that there is no deviation between the M / C detection value and the CAL detection value, and if the difference is outside the specified range, it determines that there is a deviation between the M / C detection value and the CAL detection value. When there is no deviation between the M / C detection value and the CAL detection value, the hydraulic pressure modulator 6 is in a normal operating state as shown in FIG. 7. In a normal operating state, as indicated by the dashed arrow A1 in FIG. 7, only the main flow paths (flow paths 1a, 1b) are connected, and brake fluid is supplied from the master cylinder 2 to the brake caliper 113 via the main flow path. If the M / C detection value and the CAL detection value are different, the process proceeds to step S102, otherwise the process proceeds to step S119 in FIG.

[0031] In step S102, the setting unit 74 determines whether the CAL detection value is greater than the M / C detection value. If the CAL detection value is greater than the M / C detection value, the hydraulic pressure modulator 6 is in the pressurization assist operation state shown in FIG. 8. In the pressurization assist operation state, as shown by the dashed arrow A2 in FIG. 8, the supply flow path (flow path 1c) is further opened, and brake fluid is supplied from the master cylinder 2 to the brake caliper 113 via the supply flow path. In this operation state, the solenoid valve 10 can be closed as appropriate to adjust the pressurization. If the CAL detection value is greater than the M / C detection value, the process proceeds to step S103; otherwise, the process proceeds to step S112 in FIG. 5.

[0032] In step S103, the setting unit 74 determines that the hydraulic pressure modulator 6 is currently in an operating state during pressurization assist, and increments (+1) the number of control cycles of pressurization assist (cycle count). Next, in step S104, the setting unit 74 determines whether the pressurization assist is in the first cycle. If it is the first cycle, the process proceeds to step S105, and if it is the second cycle or later, the process proceeds to step S108.

[0033] In step S105, the setting unit 74 corrects the M / C detection value based on the amount of decrease in hydraulic pressure due to the pump 14 drawing in brake fluid (hereinafter, sometimes referred to as the hydraulic pressure decrease amount), and calculates the resulting value as the "M / C correction value." During operation during pressurization assist, as shown in FIG. 8, the solenoid valve 11 is open and the motor 15 is running. Therefore, in the portion where hydraulic pressure is detected by the M / C pressure sensor 8, brake fluid is drawn (sucked) into the pump 14 via the solenoid valve 11, and the hydraulic pressure in that portion may decrease. As a result, the hydraulic pressure detected by the M / C pressure sensor 8 (the M / C detection value) becomes lower than the value corresponding to the rider's brake operation. Therefore, in step S105, the setting unit 74 calculates the M / C correction value by correcting the M / C detection value by the hydraulic pressure decrease amount. For example, the setting unit 74 can calculate a value obtained by offsetting the M / C detection value by the hydraulic pressure decrease amount as the "M / C correction value." The amount of hydraulic pressure decrease may be understood as the amount of brake fluid flowing into the sub-flow path (flow path 1d) via the supply flow path (flow path 1c), and can be obtained in advance by experiment, simulation, or the like.

[0034] In step S106, the setting unit 74 sets the M / C correction value calculated in step S105 as the operation estimated value. Next, in step S107, the setting unit 74 prohibits a release determination in the next control cycle of the pressure assist. The release determination is a process of determining whether or not the rider has released the brake operation, i.e., whether or not the rider has released the brake lever 106, and is performed in step S127 of FIG. 6, which will be described later. Because the release determination is performed based on a decrease in the M / C detection value, it may be erroneously determined that the rider has released the brake operation depending on the amount of hydraulic pressure decrease during pressure assist. To prevent such an erroneous determination from causing the pressure assist to be unintentionally released or reduced, in step S107, a release determination in the next control cycle is prohibited. After step S107 is completed, the process proceeds to step S120 of FIG. 6.

[0035] Step S108 is a process to which the process proceeds if, in step S104 above, the pressurization assist is in the second cycle or later. In step S108, the setting unit 74 determines whether the M / C detection value is decreasing. Reasons for the M / C detection value decreasing include the release of the brake operation by the rider and the occurrence of a decrease in hydraulic pressure due to the pump 14 during pressurization assist. If the M / C detection value is decreasing, the process proceeds to step S109; otherwise, the process proceeds to step S111.

[0036] In step S109, the setting unit 74 determines whether the M / C correction value is smaller than the M / C detection value. If the M / C correction value is smaller than the M / C detection value, it can be determined that the reason for the decrease in the M / C detection value is the occurrence of a decrease in hydraulic pressure by the pump 14 during pressurization assist. Therefore, in this case, the process proceeds to step S110, where the setting unit 74 sets the M / C correction value calculated in step S105 (i.e., the M / C correction value for the first cycle) as the estimated operation value. In other words, the estimated operation value is not updated. On the other hand, if the M / C correction value is equal to or greater than the M / C detection value, the process proceeds to step S111, where the setting unit 74 sets the M / C detection value as the estimated operation value. In other words, the estimated operation value is updated based on the M / C detection value. After step S110 or step S111 is completed, the process proceeds to step S120 in FIG. 6.

[0037] Step S112 in FIG. 5 is a step that is executed if the CAL detection value is equal to or less than the M / C detection value in step S102. In step S112, the setting unit 74 resets the number of control cycles of the pressurization assist. Next, in step S113, the setting unit 74 determines whether the ABS control in progress flag is "1," i.e., whether ABS control is being performed by the hydraulic pressure modulator 6. In this embodiment, since a control means (e.g., an ECU) for executing ABS control by the hydraulic pressure modulator 6 is provided separately from the control unit 7 (processing unit 71, setting unit 74), the setting unit 74 executes the determination in step S113 based on the ABS control in progress flag of that control means. If the ABS control in progress flag is "1," the process proceeds to step S114; otherwise, the process proceeds to step S119.

[0038] When the ABS control in progress flag is "1", the hydraulic pressure modulator 6 is in an operating state during ABS control. In an operating state during ABS control in which the brake caliper pressure is being reduced (hereinafter, sometimes referred to as "ABS pressure reduction in progress"), the secondary flow paths (flow paths 1d, 1e) are connected, and brake fluid is returned from the brake caliper 113 to the master cylinder 2 via the secondary flow paths, as shown by dashed arrow A3 in Fig. 9. In an operating state during ABS control in which the brake caliper pressure is being maintained (hereinafter, sometimes referred to as "ABS maintenance in progress"), the motor 15 is stopped and the solenoid valve 13 is closed, in contrast to the operating state shown in Fig. 9. In an operating state during ABS control in which the brake caliper pressure is being increased (hereinafter, sometimes referred to as "ABS pressure increase in progress"), the motor 15 is stopped, the solenoid valve 13 is closed, and the solenoid valve 12 is opened, in contrast to the operating state shown in Fig. 9.

[0039] In step S114, the setting unit 74 determines whether the increase / decrease polarities of the M / C detected value and the CAL detected value are opposite. For example, if the M / C detected value is increasing while the CAL detected value is decreasing, or if the M / C detected value is decreasing while the CAL detected value is increasing, the setting unit 74 can determine that the increase / decrease polarities of the M / C detected value and the CAL detected value are opposite. If the increase / decrease polarities of the M / C detected value and the CAL detected value are opposite, it can be determined that the ABS pressure is being reduced as shown in FIG. 9, or that the deviation between the M / C detected value and the CAL detected value that occurs when the brake caliper pressure increase in ABS control begins is being eliminated. In this case, the process proceeds to step S115. On the other hand, if the increase / decrease polarities of the M / C detected value and the CAL detected value are not opposite, it can be determined that the brake caliper pressure is being reduced due to the brake operation by the rider. In this case, the process proceeds to step S119.

[0040] In step S115, the setting unit 74 determines whether the M / C correction value is equal to or less than the CAL detection value. If the M / C correction value is equal to or less than the CAL detection value, it can be determined that an increase in the brake caliper pressure is occurring due to the brake operation by the rider. Specifically, it can be determined that, although ABS control is in progress, the brake caliper pressure is increased, eliminating the pressure difference between the brake caliper pressure and the master cylinder pressure, and that the two pressures are about to become equal. In this case, the process proceeds to step S116, where the setting unit 74 sets the CAL detection value as the estimated operation value. In other words, the estimated operation value is updated based on the CAL detection value. On the other hand, if the M / C correction value is greater than the CAL detection value, it can be determined that the fluctuation in the M / C detection value is due to the influence of control by the hydraulic pressure modulator 6. In this case, the process proceeds to step S117, where the setting unit 74 sets the M / C correction value calculated in step S105 (i.e., the M / C correction value for the first cycle) as the estimated operation value. In other words, the estimated operation value is not updated.

[0041] Furthermore, if step S117 is performed, in step S118, the setting unit 74 changes the threshold value related to the increase rate of the M / C detection value. This threshold value is used to determine whether to perform brake assist in step S121 of FIG. 6, which will be described later. Here, the threshold value may be changed so as to increase by a predetermined amount. When the solenoid valve 12 (inlet valve) is closed, the flow path downstream of the solenoid valve 12 (toward the brake caliper 113) is closed. This reduces the escape route for brake fluid compared to normal operating conditions, and the master cylinder pressure tends to increase more easily. As a result, even if the amount of brake operation by the rider is the same, the master cylinder pressure when the solenoid valve 12 is closed may be higher than the master cylinder pressure when the solenoid valve 12 is open. In this way, when the solenoid valve 12 is closed, an event may occur in which the brake assist (pressure assist) malfunctions even when no emergency braking operation is performed (for example, only a slight braking operation is performed). For this reason, the threshold value is increased in step S118.

[0042] FIG. 10 is a diagram for explaining steps S114 to S117. In FIG. 10, the horizontal axis represents time and the vertical axis represents pressure, and the M / C detected value, the M / C corrected value, and the CAL detected value are illustrated as examples. In a certain control cycle C1, the increase / decrease polarities of the M / C detected value and the CAL detected value are opposite, so the process proceeds to Yes in step S114, and the M / C corrected value is greater than the CAL detected value, so the process proceeds to No in step S114. In this case, in step S117, the M / C corrected value is set as the estimated operation value. On the other hand, in the subsequent control cycle C2, the increase / decrease polarities of the M / C detected value and the CAL detected value are opposite, so the process proceeds to Yes in step S114, and the M / C corrected value and the CAL detected value are equal, so the process proceeds to Yes in step S114. In this case, in step S116, the CAL detected value is set as the estimated operation value.

[0043] Step S119 is the process to be performed if the M / C detected value and the CAL detected value are different from each other in step S101 of Fig. 4, if the ABS control in progress flag is not "1" in step S113, or if the increase / decrease polarities of the M / C detected value and the CAL detected value are not opposite in step S114. In step S119, the setting unit 74 sets the M / C detected value as the operation estimated value. That is, the operation estimated value is updated by the M / C detected value.

[0044] Step S120 in FIG. 6 is a process that is performed when the flowchart in FIG. 4 or FIG. 5 has ended. In step S120, the processing unit 71 determines whether or not the M / C detection value is equal to or greater than a specified value. The specified value is a value for determining whether or not to execute brake assist (pressure assist) in response to an emergency brake operation for suddenly stopping the vehicle 100, and can be set in advance through experiments, simulations, etc. If the M / C detection value is equal to or greater than the specified value, there is a high possibility that an emergency brake operation has been performed by the rider. Therefore, if the M / C detection value is equal to or greater than the specified value, it is desirable to execute brake assist (pressure assist) to assist the emergency brake operation. If the M / C detection value is equal to or greater than the specified value, the process proceeds to step S121. On the other hand, if the M / C detection value is less than the specified value, the process proceeds to step S129, where the processing unit 71 determines not to intervene in brake assist.

[0045] In step S121, the processing unit 71 determines whether the increase rate (increase rate) of the M / C detection value is equal to or greater than a threshold value. The increase rate of the M / C detection value can be obtained by differentiating the M / C detection value. The threshold value is a value for determining whether or not to execute brake assist (pressure assist) in response to an emergency brake operation, and can be set in advance through experiments, simulations, or the like. Furthermore, when the above-mentioned step S118 is performed, the threshold value changed in step S118 can be used. This step S121 allows a two-stage determination to avoid malfunction of brake assist (pressure assist) when an emergency brake operation is not being performed by the rider, in conjunction with step S120. If the increase rate of the M / C detection value is equal to or greater than the threshold value, the processing unit 71 proceeds to step S122. On the other hand, if the increase rate of the M / C detection value is less than the threshold value, the processing unit 71 proceeds to step S129, where the processing unit 71 determines not to intervene in brake assist.

[0046] In step S122, the processing unit 71 determines whether the roll angle (bank angle) of the vehicle 100 is smaller than an angle threshold value based on the detection result of the inertial sensor 121. For example, the roll angle of the vehicle 100 can be obtained by integrating the angular velocity in the roll direction detected by the inertial sensor 121. If the roll angle of the vehicle 100 is large, performing brake assist (pressure assist) in addition to an emergency braking operation may cause the posture of the vehicle 100 to become unstable. Therefore, the angle threshold value can be set, through experiments, simulations, etc., to a value (e.g., a limit value) that can stabilize the posture of the vehicle 100 even if brake assist is performed in addition to an emergency braking operation. If the roll angle of the vehicle 100 is smaller than the angle threshold value, the process proceeds to step S123. On the other hand, if the roll angle of the vehicle 100 is equal to or greater than the angle threshold value, the process proceeds to step S129, where the processing unit 71 determines not to intervene in brake assist.

[0047] In step S123, the processing unit 71 initiates brake assist intervention based on the operation estimated value. Next, in step S124, the processing unit 71 determines a brake assist gain (assist gain) according to the vehicle speed (speed of the vehicle 100) at the time of brake assist intervention. The assist gain may be understood as an amplification factor of pressure. The vehicle speed can be obtained based on the detection result of the wheel speed sensor 114. For example, information indicating the relationship between the vehicle speed and the assist gain, as shown in FIG. 11, is pre-stored in the storage unit 72, and the processing unit 71 can determine the assist gain from the vehicle speed based on the information. In this embodiment, the vehicle speed and the assist gain have a logarithmic proportional relationship. By establishing this relationship, the brake assist intervention amount can be made uniform even when the vehicle speed changes, thereby reducing the rider's discomfort. Here, in the relationship between the vehicle speed and the assist gain shown in FIG. 11, the assist gain decreases sharply when the vehicle speed is 30 km / h or less. However, the brake assist intervention amount itself is small at vehicle speeds 30 km / h or less, so the rider is less likely to feel uncomfortable. As the vehicle speed increases, the amount of brake assist may be reduced to reduce the impact on aerodynamics and handling stability. Also, although an assist gain may be set even when the vehicle speed is 50 km / h or higher, it is preferable that the assist gain be set at a vehicle speed below 50 km / h.

[0048] In step S125, the processing unit 71 changes the distribution of braking force (brake assist) between the front and rear of the vehicle 100, i.e., the distribution of braking force (brake assist) between the front wheels FW and the rear wheels RW, in accordance with the pitch angle of the vehicle 100. The pitch angle of the vehicle can be obtained by integrating the angular velocity in the pitch direction detected by the inertial sensor 121. For example, as the pitch angle, in which the direction in which the front of the vehicle 100 points downward is the positive direction, increases, the processing unit 71 changes the distribution of braking force between the front wheels FW and the rear wheels RW so that the braking force of the rear wheels RW is greater than the braking force of the front wheels FW. As an example, when the pitch angle in the positive direction increases due to an emergency braking operation, brake assist is intervened in the brake device 130 (hydraulic pressure modulator 6) of the rear wheels RW, and brake assist is not intervened in the brake device 130 (hydraulic pressure modulator 6) of the front wheels FW. This makes it possible to stabilize the posture of the vehicle 100 in the pitch direction.

[0049] In step S126, the processing unit 71 increases or maintains the brake assist amount according to the time that has elapsed since the brake assist intervention was started in step S123. For example, the processing unit 71 increases the brake assist amount at a predetermined rate until a predetermined time has elapsed since the brake assist intervention was started, and maintains the brake assist amount constant after the predetermined time has elapsed.

[0050] In step S127, the processing unit 71 determines whether the rider's brake operation has been released based on the estimated operation value (release determination). For example, the processing unit 71 can determine that the rider's brake operation has been released if the estimated operation value falls below a threshold. Alternatively, the processing unit 71 can perform the release determination based on the amount of decrease in the estimated operation value obtained in the current control cycle (the estimated operation value of the current control cycle) relative to the estimated operation value obtained in the previous control cycle (the estimated operation value of the previous control cycle). In this case, if the value obtained by subtracting the estimated operation value of the current control cycle from the estimated operation value of the previous control cycle is equal to or greater than zero, the processing unit 71 integrates the obtained value, and determines that the rider's brake operation has been released if the integrated value exceeds a specified value (e.g., 0.2 MPa). If it is determined that the brake operation has been released, the processing proceeds to step S128; otherwise, the processing unit 71 ends the flowchart. Note that, as described above, in step S107, if the control cycle is a pressure assist control cycle for which the release determination has been prohibited by the setting unit 74, the processing unit 71 does not perform the release determination in step S127 regardless of the amount of decrease in the estimated operation value.

[0051] In step S128, the processing unit 71 reduces the brake assist amount (pressure assist amount) based on the operation estimated value. For example, the processing unit 71 can reduce the brake assist amount in accordance with the rate of decrease of the operation estimated value. This cancels the brake assist intervention.

[0052] As described above, the brake device 130 of this embodiment determines the operating state of the hydraulic pressure modulator 6 based on the M / C detection value and the CAL detection value, and controls the brake assist by the hydraulic pressure modulator 6 according to the determination result. This makes it possible to perform appropriate brake assist according to the brake operation intended by the rider.

[0053] [Variations] In the above example of this embodiment, the estimated operation value is set (changed) in accordance with the determination result of the operating status of the hydraulic modulator 6. However, this is not limiting, and the estimated operation value may be set based on a value determined from the M / C detection value and the CAL detection value. For example, the setting unit 74 may set the estimated operation value based on an average value of the M / C detection value and the CAL detection value. In this case, the setting unit 74 may set the average value as the estimated operation value. Note that the setting unit 74 may also set the estimated operation value based on a value obtained by passing the average value through a low-pass filter that attenuates frequency components higher than a predetermined frequency.

[0054] Second Embodiment A second embodiment of the present invention will be described. This embodiment basically follows on from the first embodiment, and can follow the first embodiment except for the matters mentioned below. Here, compared to the first embodiment, this embodiment has the same configurations of the vehicle 100 and the brake device 130, but differs in the method of controlling the brake device 130. Therefore, the control method of the brake device 130 in this embodiment will be described below.

[0055] 12 and 13 are flowcharts showing a control method for the brake device 130 in this embodiment. The flowcharts of FIGS. 12 and 13 can be executed by the control unit 7. Specifically, the flowchart of FIG. 12 is executed by the setting unit 74, and the flowchart of FIG. 13 is executed by the processing unit 71. In addition, the flowcharts of FIGS. 12 and 13 can be executed repeatedly. The flowchart of FIG. 12 and the flowchart of FIG. 13 may be executed separately in parallel.

[0056] In step S201, the setting unit 74 determines whether or not there is a difference between the M / C detection value and the CAL detection value. If there is a difference between the M / C detection value and the CAL detection value, the process proceeds to step S202; otherwise, the process proceeds to step S205 in FIG. 13. In step S202, the setting unit 74 determines whether or not the CAL detection value is greater than the M / C detection value. If the CAL detection value is greater than the M / C detection value, the process proceeds to step S203; otherwise, the process proceeds to step S205 in FIG. 13. In step S203, the setting unit 74 determines that the hydraulic modulator 6 is currently in an operating state during pressurization assist. Note that steps S201 to S203 are similar to steps S101 to S103 in FIG. 4, respectively, and therefore detailed description thereof will be omitted here.

[0057] In step S204, the setting unit 74 estimates the amount of brake fluid (hereinafter, sometimes referred to as the inflow amount) flowing from the supply flow path (flow path 1c) to the sub-flow path (flow path 1d). For example, the setting unit 74 acquires from the processing unit 71 an assist command value that is supplied to the hydraulic pressure modulator 6 (each of the solenoid valves 10 to 13, the motor 15) by the processing unit 71 during pressurization assist. This allows the setting unit 74 to estimate (calculate) the inflow amount of brake fluid based on the assist command value acquired from the processing unit 71 and the master cylinder pressure (M / C detection value) detected by the M / C pressure sensor 8.

[0058] 13, in step S205, the processing unit 71 determines whether the M / C detection value is equal to or greater than a specified value. If the M / C detection value is equal to or greater than the specified value, the process proceeds to step S206. On the other hand, if the M / C detection value is less than the specified value, the process proceeds to step S214, where the processing unit 71 determines not to intervene in the brake assist. Next, in step S206, the processing unit 71 determines whether the increase rate of the M / C detection value is equal to or greater than a threshold. If the increase rate of the M / C detection value is equal to or greater than the threshold, the process proceeds to step S207, where the processing unit 71 starts the brake assist intervention. On the other hand, if the increase rate of the M / C detection value is less than the threshold, the process proceeds to step S214, where the processing unit 71 determines not to intervene in the brake assist. Note that steps S205 to S207 are similar to steps S120 to S121 and S123 in FIG. 6, respectively, and therefore detailed description thereof will be omitted here.

[0059] In step S208, the processing unit 71 calculates the brake assist amount based on the M / C detection value. For example, information indicating the relationship between the M / C detection value and the assist amount of hydraulic pressure applied to the brake caliper 113 is acquired in advance by experiment, simulation, or the like and stored in the memory unit 72. This allows the processing unit 71 to calculate the brake assist amount from the M / C detection value based on the information.

[0060] In step S209, the processing unit 71 determines whether or not it has been determined that pressurization assist is in progress. For example, if the setting unit 74 determines that pressurization assist is in progress in step S203, the processing unit 71 can determine that it has been determined that pressurization assist is in progress. If it has been determined that pressurization assist is in progress, the process proceeds to step S210, where the processing unit 71 adds the inflow amount estimated in step S204 to the brake assist amount calculated in step S208. In this case, the processing unit 71 controls the hydraulic pressure modulator 6 based on the value obtained by adding the inflow amount to the brake assist amount. On the other hand, if it has been determined that pressurization assist is in progress, step S210 is skipped. In this case, the processing unit 71 controls the hydraulic pressure modulator 6 based on the brake assist amount calculated in step S208.

[0061] In step S211, the processing unit 71 increases or maintains the brake assist amount depending on the time that has elapsed since the brake assist intervention was started in step S207. Next, in step S127, the processing unit 71 determines whether or not the rider's brake operation has been released. If it is determined that the brake operation has been released, the process proceeds to step S123, where the processing unit 71 decreases the brake assist amount (pressure assist amount). On the other hand, if it is determined that the brake operation has been released, the process ends. Note that steps S211 to S213 are similar to steps S126 to S128 in FIG. 6, respectively, and therefore detailed description thereof will be omitted here.

[0062] The control method for the brake device 130 of this embodiment described above also makes it possible to perform appropriate brake assist in accordance with the brake operation intended by the rider.

[0063] Third Embodiment A third embodiment of the present invention will be described. In this embodiment, a specific example (modification) of the release determination performed in step S127 of FIG. 6 in the first embodiment or in step S212 of FIG. 13 in the second embodiment will be described. Note that this embodiment basically inherits the first embodiment, and can follow the first embodiment except for the matters mentioned below. Furthermore, the second embodiment may also be applied to this embodiment.

[0064] 14 is a flowchart showing the release determination (steps S127, S211) of this embodiment. The flowchart in FIG. 14 can be executed by the control unit 7 (processing unit 71).

[0065] In step S301, the processing unit 71 determines whether or not a decrease in the M / C detection value equal to or greater than a first predetermined value has been detected by the M / C pressure sensor 8. The first predetermined value can be obtained in advance by experiment, simulation, or the like as the amount of decrease in the M / C detection value for determining whether or not the rider's brake operation has been released. If a decrease in the M / C detection value equal to or greater than the first predetermined value has been detected, the processing proceeds to step S302, where the processing unit 71 starts counting (timekeeping) using a timer. On the other hand, if a decrease in the M / C detection value equal to or greater than the first predetermined value has not been detected, the flowchart (i.e., the flowchart of FIG. 6 or FIG. 13) ends. In this case, the flowchart of FIG. 4 or FIG. 12 can be started again.

[0066] In step S303, the processing unit 71 determines whether or not an increase in the M / C detection value equal to or greater than a second predetermined value has been detected by the M / C pressure sensor 8. The second predetermined value can be obtained in advance through experiments, simulations, or the like as an increase in the M / C detection value for determining whether or not the rider has applied the brakes again after a decrease in the M / C detection value equal to or greater than the first predetermined value has been detected in step S301 due to the rider releasing the brake operation. The second predetermined value may be the same as or different from the first predetermined value used in step S301.

[0067] If an increase in the M / C detection value equal to or greater than the second predetermined value is not detected in step S303, the process proceeds to step S304, where the processing unit 71 continues counting using the timer. Next, in step S305, the processing unit 71 determines whether the timer has expired, i.e., whether a specified time has elapsed since a decrease in the M / C detection value equal to or greater than the first predetermined value was detected in step S301. If the timer has not expired, the process returns to step S303. On the other hand, if the timer has expired, the process proceeds to step S306, where the processing unit 71 changes the estimated operation value based on the M / C detection value obtained by the M / C pressure sensor 8 while the timer is running (i.e., during the specified time). Then, in step S307, the processing unit 71 determines whether the change amount (e.g., the decrease amount) of the estimated operation value in step S306 is greater than a threshold value. If the change amount of the estimated operation value is greater than the threshold value, the process proceeds to step S128 in FIG. 6 or step S213 in FIG. 13, where the processing unit 71 reduces the brake assist amount based on the changed estimated operation value.

[0068] 15 is a diagram illustrating an example of the release determination according to this embodiment, showing a flow of steps S301 to S307. When a decrease D1 in the M / C detection value equal to or greater than a first predetermined value is detected (Yes in S301), the processing unit 71 starts counting using a timer at time Ts (S302). Time Ts may be the timing when the decrease in the M / C detection value reaches the first predetermined value, or the timing when the monotonous decrease in the M / C detection value equal to or greater than the first predetermined value ends. Next, when an increase in the M / C detection value equal to or greater than a second predetermined value is not detected until time Te when the timer expires (i.e., during the specified time) (No in S303 → Yes in S304 → S305), the processing unit 71 changes the operation estimated value based on the M / C detection value (S306). 15 shows an example in which the estimated operation value is changed to the M / C detected value at time Te when the timer expires (i.e., when a specified time has elapsed), but the estimated operation value may also be changed to the M / C detected value at time Ts when counting by the timer starts (i.e., when a decrease in the M / C detected value equal to or greater than a first predetermined value is detected). Furthermore, the processing unit 71 determines whether or not the change amount D2 of the estimated operation value is greater than a threshold value (S307), and reduces the brake assist amount if the change amount D2 is greater than the threshold value.

[0069] In the hydraulic circuit 1, fluctuations (increases and decreases) called hunting may occur in the master cylinder pressure. Accordingly, the M / C detection value may also fluctuate as shown in the specified time (the period from time Ts to time Te) in FIG. 15 . Such hunting of the M / C detection value does not reflect the rider's brake operation. Therefore, if a release determination is made based on hunting of the M / C detection value, it may be erroneously determined that the rider has braked again, making it difficult to make the release determination accurately. In this embodiment, the release determination is made when a specified time has elapsed since a decrease in the M / C detection value equal to or greater than the first predetermined value was detected. The release determination is made using the amount of change in the operation estimated value that was changed based on the M / C detection value during the specified time. This reduces the influence of hunting of the M / C detection value on the release determination, preventing erroneous determination and enabling the release determination to be made accurately.

[0070] If an increase in the M / C detection value equal to or greater than the second predetermined value is detected in step S303, the process proceeds to step S308, where the processing unit 71 ends counting by the timer. Next, in step S309, the processing unit 71 changes the operation estimated value based on the M / C detection value. For example, the processing unit 71 changes the operation estimated value to the M / C detection value when an increase in the M / C detection value equal to or greater than the second predetermined value is detected.

[0071] 16 is a diagram illustrating another example of the release determination according to this embodiment, showing a flow of steps S301 to S303 and S308 to S309. When a decrease D1 in the M / C detection value equal to or greater than a first predetermined value is detected (Yes in S301), the processing unit 71 starts counting using a timer at time Ts (S302). Next, when an increase D3 in the M / C detection value equal to or greater than a second predetermined value is detected before time Te when the timer expires (i.e., during the specified time) (Yes in S303), the processing unit 71 stops counting using the timer (S308) and changes the estimated operation value based on the M / C detection value (S309). For example, the processing unit 71 changes the estimated operation value to the M / C detection value when the increase D3 in the M / C detection value equal to or greater than the second predetermined value is detected.

[0072] In this way, when an increase in the M / C detection value equal to or greater than the second predetermined value is detected within the specified time, it can be determined that the rider has performed a brake operation again. The second predetermined value can be set to a value greater than the maximum amplitude (maximum fluctuation amount) of hunting that can occur in the M / C detection value through experiments, simulations, etc. Therefore, the influence of hunting in the M / C detection value on the release determination can be reduced, and the release determination can be performed with high accuracy. Furthermore, in this embodiment, the estimated operation value is changed to the M / C detection value when an increase in the M / C detection value equal to or greater than the second predetermined value is detected. It can be said that the changed estimated operation value reflects the brake operation intended by the rider, and therefore it is possible to improve the ability to follow the rider's brake operation.

[0073] <Fourth embodiment> A fourth embodiment of the present invention will be described. In this embodiment, an example will be described in which a detected M / C pressure value is obtained by performing a filtering process on the output of the M / C pressure sensor 8. This embodiment basically follows on from the first embodiment, and can follow the first embodiment except for the matters mentioned below. In addition, the second embodiment and / or the third embodiment may also be applied to this embodiment.

[0074] FIG. 17 shows waveforms obtained by filtering the output (actual detected value) of the M / C pressure sensor 8 using multiple filters F1 to F2. In FIG. 17, the horizontal axis represents time, and the vertical axis represents the output of the M / C pressure sensor 8. For convenience, in FIG. 17, waveforms obtained by filtering the output of the M / C pressure sensor 8 using the multiple filters F1 to F2 are denoted as "F1" and "F2," respectively, and the waveform obtained by not filtering the output of the M / C pressure sensor 8 (i.e., the output of the M / C pressure sensor 8 itself) is denoted as "F0." Each of the multiple filters F1 to F2 is, for example, a low-pass filter, and is configured to remove high-frequency components that occur in the output of the M / C pressure sensor 8 due to fluctuations (hunting) in the master cylinder pressure. Furthermore, the multiple filters F1 to F2 may be configured to have different pass frequency bands. While this embodiment describes an example in which two filters F1 to F2 are used, the number of filters is not limited to two and may be three or more.

[0075] The control unit 7 (processing unit 71) filters the output of the M / C pressure sensor 8 using multiple filters F1 to F2. Figure 17(a) shows the results (waveforms) of filtering the output of the M / C pressure sensor 8 using the filters F1 to F2. Compared to filter F2, filter F1 has a pass frequency band set to the higher frequency side, making it easier for high-frequency components to pass through. When filters F1 to F2 are configured as low-pass filters, the high-frequency components in the output of the M / C pressure sensor 8 are attenuated, delaying the rise of the signal and increasing the time it takes to reach a peak value. In other words, the multiple waveforms obtained by filtering the output of the M / C pressure sensor 8 using the filters F1 to F2 have peak values ​​at different times.

[0076] The control unit 7 determines the maximum value of the multiple values ​​obtained by filtering the output of the M / C pressure sensor 8 using each of the multiple filters F1 to F2, as shown by the thick line in Figure 17(b), i.e., the maximum value for each time in the multiple waveforms, as the detected M / C pressure value. Figure 18 shows the results of comparing the detected M / C values ​​when filtering using the multiple filters F1 to F2 is performed and when no filtering is performed. As shown in Figure 18, the detected M / C value obtained by filtering has reduced fluctuations compared to when no filtering is performed.

[0077] This reduces the influence of fluctuations (hunting) in the master cylinder pressure, enabling appropriate brake assist to be performed in response to the rider's brake operation. For example, not only the M / C detected value but also the M / C corrected value obtained by correcting the M / C detected value based on the amount of hydraulic pressure reduction (amount of suction) can be obtained with the influence of hunting reduced, allowing for accurate calculation of the operation estimated value. Here, filtering using multiple filters may be performed on the output of the CAL pressure sensor 9. In this case, a CAL detected value with the influence of hunting reduced can be obtained.

[0078] <Summary of the embodiment> (Item 1) A vehicle brake device (e.g., 130) having a master cylinder (e.g., 2) and a brake caliper (e.g., 113), a modulator (e.g., 6) having a main flow path (e.g., 1a, 1b) for flowing brake fluid from the master cylinder to the brake caliper, a sub-flow path (e.g., 1d, 1e) for returning the brake fluid from the brake caliper to the main flow path, and a supply flow path (e.g., 1c) for supplying the brake fluid from the main flow path to the sub-flow path, and controlling the flow of the brake fluid in the main flow path, the sub-flow path, and the supply flow path by a plurality of valves (e.g., 10 to 13); a first detection means (e.g., 8) for detecting a cylinder pressure, which is the pressure of the brake fluid in the master cylinder; a second detection means (e.g., 9) for detecting a caliper pressure, which is the pressure of the brake fluid in the brake caliper; a control means (e.g., 7) that determines an operating condition of the modulator based on the detection value of the cylinder pressure by the first detection means and the detection value of the caliper pressure by the second detection means, and controls the brake assist by the modulator in accordance with the determination result; A brake device comprising: According to this item, in a brake device having a reflux type modulator, the operating status of the modulator can be taken into consideration and appropriate brake assist can be performed in accordance with the brake operation intended by the driver.

[0079] (Item 2) The brake device according to item 1, characterized in that the control means estimates the amount of brake operation by the driver based on a determination result of the operating status of the modulator, and controls the brake assist based on the estimated value of the amount of brake operation. According to this item, the brake operation intended by the driver can be appropriately estimated according to the operating conditions of the modulator, and the brake assist can be controlled based on the estimated results, thereby providing appropriate brake assist according to the brake operation intended by the driver.

[0080] (Item 3) 3. The brake device according to claim 2, wherein the control means determines whether the driver's brake operation has been released based on the estimated value of the brake operation amount, and cancels the brake assist when it determines that the driver's brake operation has been released. According to this item, appropriate brake assist can be performed in accordance with the brake operation intended by the driver, even if the vehicle does not have an external sensor for detecting the surrounding conditions of the vehicle.

[0081] (Item 4) The control means When a specified time has elapsed since the first detection means detected a decrease in the cylinder pressure equal to or greater than a first predetermined value, the estimated value of the brake operation amount is changed based on the detected value of the cylinder pressure; 4. The brake device according to item 3, wherein it is determined whether the driver's brake operation has been released based on the amount of change in the estimated value of the brake operation amount. According to this item, the influence of hunting of the detected value of the cylinder pressure on the release determination, which determines whether the driver's brake operation has been released, is reduced, thereby preventing erroneous determination and enabling the release determination to be performed with high accuracy.

[0082] (Item 5) 5. The brake device according to item 4, wherein the control means determines that the driver's brake operation has been released when the change amount of the estimated value of the brake operation amount is greater than a threshold value. According to this item, the release determination can be performed with high accuracy based on the amount of change in the estimated value of the brake operation amount.

[0083] (Item 6) 6. The brake device according to item 4 or 5, wherein the control means changes the estimated value of the brake operation amount to the detected value of the cylinder pressure when a decrease in the cylinder pressure equal to or greater than the first predetermined value is detected, or to the detected value of the cylinder pressure when the specified time has elapsed. According to this item, the driver's intention can be reflected in the estimated value of the brake operation amount, so that the release determination can be performed with high accuracy.

[0084] (Item 7) 7. The brake device according to any one of items 4 to 6, wherein the control means determines that the driver's brake operation has not been released when the first detection means detects an increase in the cylinder pressure of equal to or greater than a second predetermined value before the specified time has elapsed after the first detection means detects a decrease in the cylinder pressure of equal to or greater than the first predetermined value. According to this item, if an increase in cylinder pressure equal to or greater than the second predetermined value is detected within a specified time, it can be determined that the rider has applied the brakes again. In other words, release determination can be performed with high accuracy.

[0085] (Item 8) 8. The brake device according to item 7, wherein the control means changes the estimated value of the brake operation amount to the detected value of the cylinder pressure when an increase in the cylinder pressure equal to or greater than the second predetermined value is detected. According to this item, the driver's intention can be reflected in the estimated value of the brake operation amount, thereby improving the ability to follow the driver's brake operation.

[0086] (Item 9) 9. The brake device according to any one of items 2 to 8, wherein the control means cancels the brake assist when the estimated value of the brake operation amount falls below a threshold value. According to this item, appropriate brake assist can be performed in accordance with the brake operation intended by the driver, even if the vehicle does not have an external sensor for detecting the surrounding conditions of the vehicle.

[0087] (Item 10) 10. The brake device according to any one of items 2 to 9, wherein, when the detection value of the caliper pressure by the second detection means is greater than the detection value of the cylinder pressure by the first detection means, the control means corrects the detection value of the cylinder pressure by the amount of brake fluid flowing from the main flow path to the sub-flow path via the supply flow path, and sets the obtained value as the estimated value of the brake operation amount. According to this item, the amount of brake operation by the driver can be estimated taking into account the amount of brake fluid flowing from the main flow path to the secondary flow path via the supply flow path, and the brake assist can be controlled based on this estimated value, thereby avoiding an unintended reduction in the amount of brake assist or the cancellation of brake assist by the driver.

[0088] (Item 11) 11. The brake device according to any one of items 2 to 10, wherein the control means sets the detected value of the cylinder pressure as the estimated value of the brake operation amount when the detected value of the caliper pressure by the second detection means is greater than the detected value of the cylinder pressure by the first detection means and the detected value of the cylinder pressure is not decreasing. According to this item, the amount of brake operation by the driver can be appropriately estimated according to the operating state of the modulator, and the brake assist can be controlled based on the estimated value.

[0089] (Item 12) When the detection value of the caliper pressure by the second detection means is greater than the detection value of the cylinder pressure by the first detection means and the detection value of the cylinder pressure is decreasing, a correction value obtained by correcting the detected value of the cylinder pressure based on the amount of brake fluid flowing from the main flow path to the sub-flow path via the supply flow path, and if the correction value is smaller than the detected value of the cylinder pressure, the correction value is set as an estimated value of the brake operation amount; 12. The brake device according to any one of items 2 to 11, wherein if the correction value is equal to or greater than the detected value of the cylinder pressure, the detected value of the cylinder pressure is set as the estimated value of the brake operation amount. According to this item, the amount of brake operation by the driver can be appropriately estimated according to the operating state of the modulator, and the brake assist can be controlled based on the estimated value.

[0090] (Item 13) When ABS control is being performed by the modulator and the increase / decrease polarities of the cylinder pressure detected by the first detection means and the caliper pressure detected by the second detection means are opposite to each other, the control means a correction value obtained by correcting the detected value of the cylinder pressure based on the amount of brake fluid flowing from the main flow path to the sub-flow path via the supply flow path is equal to or less than the detected value of the caliper pressure, and setting the detected value of the caliper pressure as an estimated value of the brake operation amount; 13. The brake device according to any one of items 2 to 12, wherein if the correction value is greater than the detected value of the caliper pressure, the correction value is set as the estimated value of the brake operation amount. According to this item, the amount of brake operation by the driver can be appropriately estimated according to the operating state of the modulator, and the brake assist can be controlled based on the estimated value.

[0091] (Item 14) 14. The brake device according to any one of items 1 to 13, wherein the control means determines a gain of the brake assist in accordance with the speed of the vehicle. According to this item, the gain of the brake assist is determined according to the vehicle speed, so that the amount of brake assist relative to the vehicle speed can be made uniform, and the sense of discomfort felt by the driver can be reduced.

[0092] (Item 15) 15. The brake device according to any one of items 1 to 14, wherein the control means does not perform the brake assist when the bank angle of the vehicle detected by the vehicle is equal to or greater than an angle threshold value. According to this item, when the bank angle of the vehicle is large, the instability of the vehicle's posture can be reduced by performing brake assist in addition to emergency braking operation.

[0093] (Item 16) the brake devices are provided for the front wheels and the rear wheels of the vehicle, 16. The brake device according to any one of items 1 to 15, wherein the control means changes the distribution of the brake assist between the front and rear of the vehicle in accordance with the pitch angle of the vehicle detected by the vehicle. According to this item, it is possible to reduce an increase in the pitch angle of the vehicle due to an emergency braking operation, and to stabilize the attitude of the vehicle in the pitch direction.

[0094] (Item 17) 17. The brake device according to any one of items 1 to 16, wherein the control means determines the maximum value of a plurality of values ​​obtained by filtering the output of the first detection means using a plurality of filters (e.g., F1 to F2) each having a different pass frequency band as the detection value of the cylinder pressure by the first detection means. According to this item, the influence of fluctuations (hunting) in the master cylinder pressure can be reduced, and appropriate brake assist can be performed in response to the driver's brake operation.

[0095] (Item 18) Item 18. The brake device according to item 17, wherein each of the plurality of filters is a low-pass filter. According to this item, it is possible to reduce high frequency components that are the influence of fluctuations (hunting) in the master cylinder pressure.

[0096] (Item 19) A vehicle brake device (e.g., 130) having a master cylinder (e.g., 2) and a brake caliper (e.g., 113), a modulator (e.g., 6) having a main flow path (e.g., 1a, 1b) for flowing brake fluid from the master cylinder to the brake caliper, a sub-flow path (e.g., 1d, 1e) for returning the brake fluid from the brake caliper to the main flow path, and a supply flow path (e.g., 1c) for supplying the brake fluid from the main flow path to the sub-flow path, and controlling the flow of the brake fluid in the main flow path, the sub-flow path, and the supply flow path by a plurality of valves (e.g., 10 to 13); a first detection means (e.g., 8) for detecting a cylinder pressure, which is the pressure of the brake fluid in the master cylinder; a second detection means (e.g., 9) for detecting a caliper pressure, which is the pressure of the brake fluid in the brake caliper; a control means (e.g., 7) that estimates an average value of the detection value of the cylinder pressure by the first detection means and the detection value of the caliper pressure by the second detection means as a brake operation amount by the driver, and controls the brake assist by the modulator based on the estimated value of the brake operation amount; A brake device comprising: According to this item, in a brake device having a reflux type modulator, the difference between the detected value of the cylinder pressure and the hydraulic pressure corresponding to the amount of brake operation by the driver can be reduced, and appropriate brake assist can be performed according to the brake operation intended by the driver.

[0097] (Item 20) A vehicle brake device (e.g., 130) having a master cylinder (e.g., 2) and a brake caliper (e.g., 113), a modulator (e.g., 6) having a main flow path (e.g., 1a, 1b) for flowing brake fluid from the master cylinder to the brake caliper, a sub-flow path (e.g., 1d, 1e) for returning the brake fluid from the brake caliper to the main flow path, and a supply flow path (e.g., 1c) for supplying the brake fluid from the main flow path to the sub-flow path, and controlling the flow of the brake fluid in the main flow path, the sub-flow path, and the supply flow path by a plurality of valves (e.g., 10 to 13); a first detection means (e.g., 8) for detecting a cylinder pressure, which is the pressure of the brake fluid in the master cylinder; a second detection means (e.g., 9) for detecting a caliper pressure, which is the pressure of the brake fluid in the brake caliper; A control means (e.g., 7) for controlling the brake assist by the modulator; Equipped with The control means, when the detection value of the caliper pressure by the second detection means is greater than the detection value of the cylinder pressure by the first detection means, estimates the amount of brake fluid flowing from the supply flow path to the secondary flow path, and controls the brake assist based on a value obtained by adding the inflow amount to the assist amount of hydraulic pressure applied to the brake caliper. According to this item, in a brake device having a reflux type modulator, appropriate brake assist can be performed in accordance with the braking operation intended by the driver, depending on the amount of brake fluid flowing from the supply flow path to the secondary flow path.

[0098] (Item 21) A vehicle (for example, 100) having the brake device according to any one of items 1 to 20. According to this item, a vehicle is provided that is equipped with a brake device that can provide appropriate brake assist in accordance with the brake operation intended by the driver.

[0099] The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0100] 1: hydraulic circuit, 2: master cylinder, 3: reservoir, 6: hydraulic modulator, 7: control unit, 71: processing unit, 74: setting unit, 8: hydraulic pressure sensor (M / C pressure sensor), 9: hydraulic pressure sensor (CAL pressure sensor), 10 to 13: solenoid valve, 14: pump, 15: motor, 113: brake caliper, 130: brake device

Claims

1. A vehicle brake device having a master cylinder and a brake caliper, a modulator having a main flow path for flowing brake fluid from the master cylinder to the brake caliper, a sub-flow path for returning the brake fluid from the brake caliper to the main flow path, and a supply flow path for supplying the brake fluid from the main flow path to the sub-flow path, the modulator controlling the flow of the brake fluid in the main flow path, the sub-flow path and the supply flow path by a plurality of valves; a first detection means for detecting a cylinder pressure, which is the pressure of the brake fluid in the master cylinder; a second detection means for detecting a caliper pressure, which is the pressure of the brake fluid in the brake caliper; a control means for determining an operating state of the modulator based on the detected value of the cylinder pressure by the first detection means and the detected value of the caliper pressure by the second detection means, and for controlling the brake assist by the modulator in accordance with the determination result; A brake device comprising:

2. 2. The brake device according to claim 1, wherein the control means estimates the amount of brake operation by the driver based on a result of determining the operating state of the modulator, and controls the brake assist based on the estimated value of the amount of brake operation.

3. 3. The brake device according to claim 2, wherein the control means determines whether the driver's brake operation has been released based on the estimated value of the brake operation amount, and cancels the brake assist when it determines that the driver's brake operation has been released.

4. The control means When a specified time has elapsed since the first detection means detected a decrease in the cylinder pressure equal to or greater than a first predetermined value, the estimated value of the brake operation amount is changed based on the detected value of the cylinder pressure; 4. The brake device according to claim 3, wherein it is determined whether the driver has released the brake operation based on the amount of change in the estimated value of the brake operation amount.

5. 5. The brake device according to claim 4, wherein the control means determines that the driver has released the brake operation when the change amount of the estimated value of the brake operation amount is greater than a threshold value.

6. 5. The brake device according to claim 4, wherein the control means changes the estimated value of the brake operation amount to the detected value of the cylinder pressure when a decrease in the cylinder pressure equal to or greater than the first predetermined value is detected, or to the detected value of the cylinder pressure when the specified time has elapsed.

7. 5. The brake device according to claim 4, wherein the control means determines that the driver's brake operation has not been released when the first detection means detects an increase in the cylinder pressure of equal to or greater than a second predetermined value before the specified time has elapsed after the first detection means detects a decrease in the cylinder pressure of equal to or greater than the first predetermined value.

8. 8. The brake device according to claim 7, wherein the control means changes the estimated value of the brake operation amount to the detected value of the cylinder pressure when an increase in the cylinder pressure equal to or greater than the second predetermined value is detected.

9. 3. The brake device according to claim 2, wherein the control means cancels the brake assist when the estimated value of the brake operation amount falls below a threshold value.

10. 3. The brake device according to claim 2, wherein, when the detected value of the caliper pressure by the second detection means is greater than the detected value of the cylinder pressure by the first detection means, the control means sets a value obtained by correcting the detected value of the cylinder pressure based on the amount of brake fluid flowing from the main flow path to the sub-flow path via the supply flow path as the estimated value of the brake operation amount.

11. 3. The brake device according to claim 2, wherein the control means sets the detected value of the cylinder pressure as the estimated value of the brake operation amount when the detected value of the caliper pressure by the second detection means is greater than the detected value of the cylinder pressure by the first detection means and when the detected value of the cylinder pressure is not decreasing.

12. When the detected value of the caliper pressure by the second detection means is greater than the detected value of the cylinder pressure by the first detection means and the detected value of the cylinder pressure is decreasing, a correction value obtained by correcting the detected value of the cylinder pressure based on the amount of brake fluid flowing from the main flow path to the sub-flow path via the supply flow path, and if the correction value is smaller than the detected value of the cylinder pressure, the correction value is set as an estimated value of the brake operation amount; 3. The brake device according to claim 2, wherein if the correction value is equal to or greater than the detected value of the cylinder pressure, the detected value of the cylinder pressure is set as the estimated value of the brake operation amount.

13. When ABS control is being performed by the modulator and the cylinder pressure detected by the first detection means and the caliper pressure detected by the second detection means have opposite increase / decrease polarities, the control means a correction value obtained by correcting the detected value of the cylinder pressure based on the amount of brake fluid flowing from the main flow path to the sub-flow path via the supply flow path is equal to or less than the detected value of the caliper pressure, and setting the detected value of the caliper pressure as an estimated value of the brake operation amount; 3. The brake device according to claim 2, wherein if the correction value is greater than the detected value of the caliper pressure, the correction value is set as the estimated value of the brake operation amount.

14. 2. The brake device according to claim 1, wherein the control means determines a gain of the brake assist in accordance with a speed of the vehicle.

15. 2. The brake device according to claim 1, wherein the control means does not perform the brake assist when the bank angle of the vehicle detected by the vehicle is equal to or greater than an angle threshold value.

16. the brake devices are provided for the front wheels and the rear wheels of the vehicle, 2. The brake device according to claim 1, wherein the control means changes the distribution of the brake assist between the front and rear of the vehicle in accordance with a pitch angle of the vehicle detected at the vehicle.

17. 2. The brake device according to claim 1, wherein the control means determines the maximum value of a plurality of values ​​obtained by filtering the output of the first detection means using a plurality of filters each having a different pass frequency band as the detection value of the cylinder pressure detected by the first detection means.

18. 18. The braking system of claim 17, wherein each of the plurality of filters is a low-pass filter.

19. A vehicle brake device having a master cylinder and a brake caliper, a modulator having a main flow path for flowing brake fluid from the master cylinder to the brake caliper, a sub-flow path for returning the brake fluid from the brake caliper to the main flow path, and a supply flow path for supplying the brake fluid from the main flow path to the sub-flow path, the modulator controlling the flow of the brake fluid in the main flow path, the sub-flow path and the supply flow path by a plurality of valves; a first detection means for detecting a cylinder pressure, which is the pressure of the brake fluid in the master cylinder; a second detection means for detecting a caliper pressure, which is the pressure of the brake fluid in the brake caliper; a control means for estimating an average value of the detected value of the cylinder pressure by the first detection means and the detected value of the caliper pressure by the second detection means as a brake operation amount by the driver, and for controlling brake assist by the modulator based on the estimated value of the brake operation amount; A brake device comprising:

20. A vehicle brake device having a master cylinder and a brake caliper, a modulator having a main flow path for flowing brake fluid from the master cylinder to the brake caliper, a sub-flow path for returning the brake fluid from the brake caliper to the main flow path, and a supply flow path for supplying the brake fluid from the main flow path to the sub-flow path, the modulator controlling the flow of the brake fluid in the main flow path, the sub-flow path and the supply flow path by a plurality of valves; a first detection means for detecting a cylinder pressure, which is the pressure of the brake fluid in the master cylinder; a second detection means for detecting a caliper pressure, which is the pressure of the brake fluid in the brake caliper; a control means for controlling the brake assist by the modulator; Equipped with When the detection value of the caliper pressure by the second detection means is greater than the detection value of the cylinder pressure by the first detection means, the control means estimates the amount of brake fluid flowing from the supply flow path to the secondary flow path, and controls the brake assist based on a value obtained by adding the inflow amount to the assist amount of hydraulic pressure applied to the brake caliper.

21. A vehicle comprising a brake device according to any one of claims 1 to 20.

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