JP7849566B2 - Braking force control device, and saddle-type vehicle - Google Patents

Description

This invention relates to a braking force control device.

Conventionally, in mobile vehicles, brake assist technology is known that increases the braking force when the driver performs an emergency braking operation. Patent Document 1 discloses a technology that determines that an emergency braking operation has been performed and executes brake assist control when the pressure of the master cylinder of the brake mechanism and the rate of increase of that pressure satisfy a preset assist start condition.

Japanese Patent Application Publication No. 9-272418

Drivers of mobile vehicles may momentarily increase braking force while driving, even in situations where the braking operation is not intended to cause a sudden stop. This is especially true for saddle-type vehicles, where braking is often used to control vehicle behavior, such as posture control. If brake assist control is activated when the driver does not intend to stop suddenly, the driver may feel uncomfortable driving.

This specification contains all the contents of Japanese Patent Application No. 2023-056502, filed on March 30, 2023.
A braking force control device for a mobile vehicle that, when the brake assist start condition is met, performs brake assist control to generate a braking force in the braking device that is greater than or equal to the braking force corresponding to the operation of a brake operator, comprising a determination unit that compares the rate of increase of a predetermined value related to the braking device with a predetermined threshold corresponding to the rate of increase, wherein the assist start condition is determined based on the frequency with which the determination unit determines that it has exceeded the threshold, the mobile vehicle is a saddle-type vehicle equipped with front wheels and rear wheels, the front wheel and the rear wheel are provided with a front wheel braking device and a rear wheel braking device, respectively, the assist start condition includes a first assist start condition for starting the brake assist control for the front wheel braking device and a second assist start condition for starting the brake assist control for the rear wheel braking device, the first assist start condition and the second assist start condition are different conditions.
The present invention provides a braking force control device characterized by the following features.
Furthermore, in another aspect of the present invention, a saddle-type vehicle equipped with the above-described braking force control device is provided.

This system enables braking force control where brake assist control is less likely to be activated when the driver does not intend to stop suddenly, and brake assist control is activated when the driver needs to stop suddenly.

Figure 1 is an explanatory diagram of a saddle-type vehicle equipped with a braking control device according to the first embodiment. Figure 2 is a block diagram showing the configuration of the braking system for a saddle-type vehicle. Figure 3 is a block diagram showing the configuration of the braking force control device. Figure 4 is a graph showing an example of how the master cylinder pressure changes over time. Figure 5 is a graph showing an example of how the counter reading changes over time. Figure 6 is a flowchart of the brake assist function. Figure 7 is a graph showing an example of the time variation of the master cylinder pressure in the second embodiment. Figure 8 is a flowchart of the brake assist function.

Embodiments of the present invention will be described below with reference to the drawings. In the description, directions such as front, back, left, right, and up and down refer to directions relative to the vehicle body unless otherwise specified. In each figure, the symbol FR indicates the front of the vehicle body, the symbol UP indicates the top of the vehicle body, and the symbol LH indicates the left side of the vehicle body.

[Embodiment]
Figure 1 is a side view of a saddle-type vehicle 10 according to an embodiment of the present invention.
The saddle-type vehicle 10 is a vehicle that comprises a body frame 11, a power unit 12 supported by the body frame 11, a front fork 14 that supports the front wheel 13 in a steerable manner, a swing arm 16 that supports the rear wheel 15, and a seat 17 for the rider.
The saddle-type vehicle 10 is a vehicle in which the occupant sits straddling the seat 17. The seat 17 is located above the rear of the vehicle frame 11.

The vehicle frame 11 comprises a head pipe 18 located at the front end of the vehicle frame 11, a front frame 19 located behind the head pipe 18, and a rear frame 20 located behind the front frame 19. The front end of the front frame 19 is connected to the head pipe 18.
The seat 17 is supported by the rear frame 20.

The front fork 14 is supported by a head pipe 18 so that it can be steered left and right. The front wheel 13 is supported by an axle 13a provided at the lower end of the front fork 14. The steering handle 21, which is held by the rider, is attached to the upper end of the front fork 14.

The swingarm 16 is supported by a pivot shaft 22 which is supported by the vehicle frame 11. The pivot shaft 22 is an axis that extends horizontally in the vehicle width direction. The pivot shaft 22 is inserted through the front end of the swingarm 16. The swingarm 16 swings up and down around the pivot shaft 22.
The rear wheel 15 is supported by an axle 15a located at the rear end of the swing arm 16.

The power unit 12 is positioned between the front wheels 13 and the rear wheels 15 and is supported by the vehicle frame 11.
The power unit 12 is an internal combustion engine. The power unit 12 comprises a crankcase 23 and a cylinder section 24 that houses a reciprocating piston. An exhaust device 25 is connected to the exhaust port of the cylinder section 24.
The output of the power unit 12 is transmitted to the rear wheels 15 by a drive force transmission member that connects the power unit 12 to the rear wheels 15.

Furthermore, the saddle-type vehicle 10 is equipped with a front fender 26 that covers the front wheel 13 from above, a rear fender 27 that covers the rear wheel 15 from above, a step 28 on which the rider places their feet, and a fuel tank 29 that stores the fuel used by the power unit 12.
The front fender 26 is attached to the front fork 14. The rear fender 27 and step 28 are located below the seat 17. The fuel tank 29 is supported by the vehicle frame 11.

The control device 32, which controls the fuel injection and other functions of the power unit 12, is located below the seat 17. The control device 32 is a computer that includes a braking control device 59, and comprises a storage device 71 and a processor 69 that performs various functions by executing programs stored in the storage device 71, as will be described later in Figure 3.

Furthermore, an IMU (Inertial Measurement Unit) 34, which includes a 6-axis sensor, is provided below the seat 17.

The brake pedal 36 (49A) is located below the pivot shaft 22. The driver can adjust the braking force of the rear wheel 15 by operating the brake pedal 36 with their right foot. In other words, the driver can adjust the braking force of the rear brake 53 by operating the brake pedal 36 (see Figure 2, described later). Also located near the brake pedal 36 is a rear brake master cylinder 31 that converts the pedal force into hydraulic pressure for brake fluid and pumps the brake fluid to the brake caliper 62 of the rear wheel 15.

A brake lever 38 (49B) is provided on the handlebar 21. The driver can adjust the braking force of the front wheel 13 by operating the brake lever 38 with their fingers. In other words, the driver can adjust the braking force of the front brake 51 by operating the brake lever 38 (see Figure 2, described later). Also, near the brake lever 38, a front brake master cylinder 30 is provided that converts the force of squeezing the lever into hydraulic pressure and pumps brake fluid to the brake caliper 63 of the front wheel 13.

Figure 2 is a block diagram showing the configuration of the braking system 41 of the saddle-type vehicle 10.

The front brake 51 and rear brake 53 are examples of braking devices 41.

The braking control device 59, which controls the braking system 41, is connected to a hydraulic pressure sensor 57 that measures the hydraulic pressure of the brake fluid in the rear brake master cylinder 31. The braking control device 59 is also connected to a hydraulic pressure sensor 55 that measures the hydraulic pressure of the brake fluid in the front brake master cylinder 30. Furthermore, the braking control device 59 is connected to a hydraulic pressure sensor 64 that measures the hydraulic pressure in the brake caliper 62 of the rear brake and a hydraulic pressure sensor 65 that measures the hydraulic pressure in the brake caliper 63 of the front brake.

The braking control device 59 is connected to a rear wheel speed sensor 45 that measures the wheel speed of the rear wheels 15. The wheel speed information of the rear wheels 15 measured by the rear wheel speed sensor 45 is also used when the driver depresses the brake pedal 36, which is the brake control element 49A, to activate the ABS (Anti-lock-Break System) function to prevent the rear wheels 15 from locking, and when traction control is performed, etc.

The braking control device 59 is connected to a front wheel speed sensor 43 that measures the wheel speed of the front wheels 13.

Furthermore, the braking control device 59 is connected to a throttle opening sensor 47 that detects the degree to which the throttle, which adjusts the fuel injection amount in the power unit 12, is opened or closed.

The pressurizing module 61 and the rear brake master cylinder 31 are connected by piping that transmits brake fluid hydraulic pressure. Similarly, the pressurizing module 61 and the front brake master cylinder 30 are connected by piping that transmits brake fluid hydraulic pressure. Furthermore, the pressurizing module 61 and the rear brake caliper 62 are connected by piping that transmits brake fluid hydraulic pressure. Similarly, the pressurizing module 61 and the front brake caliper 63 are connected by piping that transmits brake fluid hydraulic pressure.

The braking control device 59 is also connected to the IMU 34. The braking control device 59 is connected to the pressurizing module 61 and controls the pressurizing module 61.

The braking control device 59 is included in the control device 32. Of course, the braking control device 59 and the control device 32 may be separate devices.

Figure 3 is a functional block diagram of the braking control device 59. The braking control device 59 is a computer, specifically an ECU (Electronic Control Unit). The braking control device 59 includes a processor 69 such as a CPU (Central Processing Unit), RAM (Random Access Memory), and ROM (Read Only Memory), and performs various controls. RAM is used as the CPU's work area and memory area, while ROM stores the operating system and programs executed by the CPU.
The processor 69 executes a program stored in the control program storage area 72 of the storage device 71 to realize various functions described later. The storage device 71 may be an SSD (Solid State Drive) or the like.

The processor 69 implements the function of a measuring unit 73 that measures predetermined values related to the braking system 41, including the front brake 51 and the rear brake 53. In this embodiment, the measuring unit 73 measures the hydraulic pressure of the front brake master cylinder 30 and the rear brake master cylinder 31 as predetermined values.
The hydraulic pressure of the front brake master cylinder 30 and the rear brake master cylinder 31 are examples of master cylinder pressures for braking systems.

The processor 69 further implements the function of the measuring unit 73, which measures the values of other sensors. Examples of sensors include, but are not limited to, the front wheel speed sensor 43, the rear wheel speed sensor 45, and the throttle opening sensor 47.
The braking control device 59 may also be equipped with input interface circuits for signals from each sensor.

Furthermore, the predetermined value related to the braking system 41, including the front brake 51 and the rear brake 53, measured by the measuring unit 73 may be the amount of operation of the brake lever 38 and the brake pedal 36, including the brake control element 49.

The processor 69 implements the function of a calculation unit 75 that performs predetermined calculations on predetermined values related to the braking system 41, including the front brake 51 and the rear brake 53. In this embodiment, the increase rate of the hydraulic pressure of the front brake master cylinder 30 and the rear brake master cylinder 31 is calculated.

The processor 69 implements the function of a determination unit 77, which compares the rate of increase of the hydraulic pressure in the front brake master cylinder 30 and the rear brake master cylinder 31 with the magnitude of a predetermined first threshold value stored in the storage device 71.
The determination unit 77 also determines the relationship between the count obtained by the counter 79 (described later) and the assist start condition, which is predetermined and stored in the storage device 71.

The processor 69 implements the function of a counter 79 that measures the frequency with which the determination unit 77 determines that the master cylinder pressure has risen to or above a first threshold within a predetermined period.
The counter 79 is an example of a counting unit that measures the aforementioned frequency. The count of the counter 79 is also an example of the aforementioned frequency. The counter 79 adds 1 to its initial value when the master cylinder pressure exceeds a first threshold during a unit of time within a predetermined period, and subtracts 1 from its initial value when the master cylinder pressure falls below the first threshold during a unit of time within a predetermined period. The unit of time is, for example, a few milliseconds. In other words, the system includes a counting unit that measures the frequency at which the determination unit 77 determines that a predetermined value related to the braking device exceeds a first threshold within a predetermined period, and the start of assistance is determined based on the aforementioned frequency.

The processor 69 implements the function of the pressurizing module control unit 81, which performs brake assist control to the braking device 41. Specifically, it controls the motor that moves the piston that changes the hydraulic pressure in the pressurizing module 61. When the counter 79 satisfies the assist start condition, the pressurizing module 61 pressurizes the master cylinder and performs brake assist, i.e., increases the braking force.

Figure 4 is an example of a graph showing the change in master cylinder pressure over time. The vertical axis represents master cylinder pressure, and the horizontal axis represents time. In this example, the master cylinder refers to either the front brake master cylinder 30 or the rear brake master cylinder 31. The solid line represents the change in master cylinder pressure over time (100), and the slope of the solid line corresponds to the rate of increase in master cylinder pressure. The slope of the dotted line corresponds to a predetermined first threshold (150). That is, if the slope of the solid line on the graph is greater than or equal to the slope of the dotted line, it means that the rate of increase in master cylinder pressure is greater than or equal to the first threshold. Conversely, if the slope of the solid line on the graph is less than the slope of the dotted line, it means that the rate of increase in master cylinder pressure is less than the first threshold.
Specifically, at times B and D on the graph, the rate of increase in master cylinder pressure is below the first threshold, while at times A, C, E, F, and G, the rate of increase in master cylinder pressure is above the first threshold.

Figure 5 is a graph showing an example of the time change of the counter 79. The vertical axis represents the counter 79's count, and the horizontal axis represents time. In this example, the counter 79 starts with an initial value of 0. When the master cylinder pressure increase rate is greater than or equal to the first threshold, it counts up and adds 1 to the count. When the master cylinder pressure increase rate is less than the first threshold, it counts down and subtracts 1 from the count.
Here, when the count of the counter 79 is met, the pressurizing module 61 applies pressure to the master cylinder, resulting in brake assist, or an increase in braking force. If the assist start condition is when the count reaches 3, then brake assist will start at time G. In other words, the first frequency related to the assist start condition is 3 in this case. The sensitivity of brake assist can be adjusted by changing the assist start condition. That is, if the first frequency is set to a large value, brake assist will be less likely to start, and if the first frequency is set to a small value, brake assist will be more likely to start.

Figure 6 is a flowchart illustrating the operation of the brake assist. Here, the master cylinder is the front brake master cylinder 30. The assist start condition is the first assist start condition.

First, the measurement unit 73 detects the master cylinder pressure (step SA1). Then, the calculation unit 75 calculates the rate of increase of the master cylinder pressure (step SA2). Next, the determination unit 77 compares the calculated rate of increase of the master cylinder pressure with a predetermined first threshold value stored in the storage device 71 and determines whether the rate of increase of the master cylinder pressure is equal to or greater than the first threshold value (step SA3). If the rate of increase of the master cylinder pressure is equal to or greater than the first threshold value (step SA3: YES), the counter 79 adds 1 to its count (step SA4). The determination unit 77 determines whether the count of the counter 79 has met the assist start condition predetermined and stored in the storage device 71 (step SA5). If the count of the counter 79 has met the assist start condition (step SA5: YES), the pressurizing module control unit 81 controls the pressurizing module 61 to perform brake assist (step SA6).

Returning to the explanation of step SA3, if the rate of increase of the master cylinder pressure is less than the first threshold (step SA3: NO), subtract the count of counter 79 (step SA7). Then return to step SA1.

Returning to the explanation of step SA5, if the count of counter 79 does not meet the assist start condition (step SA5: NO), return to step SA1.

Here, in the flowchart, the master cylinder may be the rear brake master cylinder 31. In this case, the assist start condition is the second assist start condition. The first assist condition and the second assist condition may be the same or different. When the first assist condition and the second assist condition are different, it is desirable that the first frequency, which is the first assist start condition, is greater than the second frequency, when comparing the first frequency, which is the first assist start condition, with the second frequency, which is the second assist start condition. This is because, when comparing the front brake 51 and the rear brake 53, if the timing at which the pressurizing module 61 increases braking force for braking the front wheel 13 by the front brake 51 is earlier than the timing at which the pressurizing module 61 increases braking force for braking the rear wheel 15 by the rear brake 53, the vehicle may stop by lurching forward in the FR direction, potentially resulting in unnatural vehicle behavior.

[Second Embodiment]
A saddle-type vehicle 10 equipped with a braking control device 59 according to the second embodiment of the present invention will be described below. The above-mentioned embodiment will be referred to as the first embodiment, and the following embodiment will be referred to as the second embodiment.
The configuration of the equipment in the saddle-type vehicle 10 equipped with the braking control device 59 according to the second embodiment is the same as that shown in Figures 1, 2, and 3 representing the previously described embodiment, so its description is omitted.
Figure 7 is a graph showing an example of the time variation of the master cylinder pressure in this embodiment. Here, unlike the first embodiment, a lower threshold _PL and an upper threshold _PH are set for the master cylinder pressure, which is related to the comparison with the assist start condition. If the master cylinder pressure is less than the lower threshold _PL , the comparison between the master cylinder pressure and the first threshold is not performed, and the master cylinder pressure does not contribute to the change in the counter 79's count. Also, if the master cylinder pressure is greater than the upper threshold _PH , the comparison between the master cylinder pressure and the first threshold is not performed, and the master cylinder pressure does not contribute to the change in the counter 79's count.
In other words, the start of assistance is determined based on the frequency with which the master cylinder pressure exceeds a first threshold when the master cylinder pressure is between a predetermined lower threshold and a predetermined upper threshold.
Figure 8 is a flowchart illustrating the operation of the brake assist in this embodiment. Here, the master cylinder is the front brake master cylinder 30. The assist start condition is the first assist start condition.

First, the measurement unit 73 detects the master cylinder pressure (step SB1). The determination unit 77 determines whether the master cylinder pressure is equal to or _greater than the lower threshold P _L (step SB2). If the master cylinder pressure is equal to or greater than the lower threshold P _L (step SB2: YES), the determination unit 77 determines whether the master cylinder pressure is less than the upper threshold _PH (step SB3). If the master cylinder pressure is less than the upper threshold PH (step SB3: YES), the calculation unit 75 calculates the rate of increase of the master cylinder pressure (step SB4). Next, the determination unit 77 compares the calculated rate of increase of the master cylinder pressure with a predetermined first threshold stored in the storage device 71 and determines whether the rate of increase of the master cylinder pressure is equal to or greater than the first threshold (step SB5). If the rate of increase of the master cylinder pressure is equal to or greater than the first threshold (step SB5: YES), the counter 79 adds 1 to the count (step SB6). The determination unit 77 determines whether the count of the counter 79 has met the assist start condition predetermined and stored in the storage device 71 (step SB7). If the count of the counter 79 meets the assist start condition (step SB7: YES), the pressurizing module control unit 81 controls the pressurizing module 61 to perform brake assist (step SB8).

Returning to the explanation for step SB2, if the master cylinder pressure is not greater than or equal to _PL (step SB2: NO), return to step SB1.

Returning to the explanation for step SB3, if the master cylinder pressure is not less than _PH (step SB3: NO), the process is terminated.

Returning to the explanation for step SB5, if the rate of increase in master cylinder pressure is not equal to or greater than the first threshold (step SB5: NO), subtract the count of counter 79 (step SB9). Then return to step SB1.

Returning to the explanation for step SB7, if the count of counter 79 does not meet the assist start condition (step SB7: NO), return to step SB1.

In this flowchart, the master cylinder may be the rear brake master cylinder 31. In this case, the assist initiation condition is the second assist initiation condition. The first assist condition and the second assist condition may be the same or different. If the first assist condition and the second assist condition are different, it is desirable that the first frequency, which is the first assist initiation condition, is greater than the second frequency, when comparing the first frequency, which is the first assist initiation condition, with the second frequency, which is the second assist initiation condition.

The above-described embodiments represent only one aspect of the present invention. The present invention is not limited to the above embodiments, and the details and other configurations may be modified as appropriate. The processing units in the flowcharts shown in Figures 6 and 8 are divided according to the main processing content in order to facilitate understanding of the processing of the braking control device 59, and the present invention is not limited by the way the processing units are divided or the names of the processing units. The operation in Figures 6 and 8 can be further divided into more processing units depending on the processing content, or one processing unit can be divided to include even more processing. Furthermore, the processing order in the flowcharts above is not limited to the illustrated examples.

[Configurations supported by the above embodiment]
The above embodiment supports the following configuration.

(Configuration 1) A braking force control device that performs brake assist control in a moving body, wherein when the conditions for starting brake assist are met, the brake device generates a braking force in the braking device that is greater than or equal to the braking force corresponding to the operation of a brake operator, and the brake force control device is characterized in that it comprises a determination unit that compares the rate of increase of a predetermined value related to the braking device with a predetermined first threshold, and the conditions for starting assist are determined based on the frequency with which the determination unit determines that the value has become greater than or equal to the first threshold.
According to this, brake assist control is less likely to be activated when the driver does not intend to stop suddenly, and brake assist control is activated when the driver needs to stop suddenly, enabling braking force control.

(Configuration 2) The braking force control device according to Configuration 1, comprising: a measuring unit for measuring a predetermined value related to the braking device; a calculation unit for calculating and determining the rate of increase of the predetermined value; a determination unit for comparing the rate of increase of the predetermined value measured by the measuring unit with a predetermined first threshold; and a counting unit for measuring the frequency with which the determination unit determines that the rate of increase of the predetermined value has become equal to or greater than the first threshold within a predetermined period.
According to this, brake assist control is less likely to be activated when the driver does not intend to stop suddenly, and brake assist control is activated when the driver needs to stop suddenly, enabling braking force control.

(Configuration 3) The braking force control device according to Configuration 1 or Configuration 2, characterized in that the predetermined value relating to the braking device is the master cylinder pressure of the braking device.
According to this, it becomes easier to distinguish between an increase in master cylinder pressure when the driver does not intend to stop suddenly and an increase in master cylinder pressure when the driver needs to stop suddenly, making it easier for brake assist control to be executed at the appropriate time for the driver.

(Configuration 4) The braking force control device according to Configuration 1 or Configuration 2, characterized in that the predetermined value is the amount of operation of the brake lever.
According to this, it becomes easier to distinguish between an increase in the amount of brake operation when the driver does not intend to stop and an increase in the amount of brake operation when the driver needs to stop suddenly, making it easier for brake assist control to be executed at the appropriate time for the driver.

(Configuration 5) The braking force control device according to Configuration 3, characterized in that the assist start condition is determined based on the frequency that occurs when the master cylinder pressure is between a predetermined lower threshold and a predetermined upper threshold.
According to this, brake assist control is less likely to be activated when the driver does not intend to stop suddenly, and brake assist control is activated when the driver needs to stop suddenly, enabling braking force control.

(Configuration 6) The braking force control device according to Configuration 1, wherein the mobile body is a saddle-type vehicle equipped with front wheels and rear wheels, and the front wheels and rear wheels are provided with a front wheel braking device and a rear wheel braking device, respectively, and the first assist start condition for starting the brake assist control for the front wheel braking device and the second assist start condition for starting the brake assist control for the rear wheel braking device are different.
According to this, by making the conditions for initiating brake assist different for the front wheel braking system and the rear wheel control system, it becomes possible to provide brake assist control that is tailored to the driver's preferences.

(Configuration 7) The braking force control device according to Configuration 6, characterized in that when comparing the first frequency, which is the first assist initiation condition, with the second frequency, which is the second assist initiation condition, the first frequency is greater than the second frequency.
In most cases, the driver applies the brakes to the rear wheels for posture control. As such, brake assist control is less likely to occur with the rear wheels, meaning that brake assist control is less likely to be activated during braking operations associated with posture control, thus less likely to cause discomfort to the driver.

(Configuration 8) The braking force control device according to Configuration 6 or Configuration 7, characterized in that the front wheel braking device is instructed to apply braking force by a brake lever operated by the driver's hand, and the rear wheel braking device is instructed to apply braking force by a brake pedal operated by the driver's foot.
When a driver intends to make an emergency stop, they are likely to grip the brake lever tightly. This makes it easier to distinguish between braking operations intended for emergency stops and braking operations using the brake pedal for posture control.

(Configuration 9) A saddle-type vehicle equipped with a braking force control device as described in Configuration 1 or Configuration 2.
According to this, a saddle-type vehicle will be realized in which brake assist control is less likely to be activated when the driver does not intend to stop suddenly, and brake assist control is activated when the driver needs to stop suddenly.

10. Saddle-type vehicle (mobile vehicle)
13 Front wheel 15 Rear wheel 36, 49A Brake pedal 38, 49B Brake lever 41 Braking device 49 Brake control 51 Front brake (front wheel braking device)
53. Rear brake (rear wheel braking system)
59 Brake control device 61 Pressure module 73 Measurement unit 75 Calculation unit 77 Judgment unit 79 Counter (counting unit)
81 Pressurization module control unit 100 Time change of master cylinder pressure 150 First threshold

Claims (8)

A braking force control device (59) that, in a moving object, performs brake assist control to generate a braking force in the braking device (41) that is greater than or equal to the braking force corresponding to the operation of the brake operator (49) when the conditions for starting brake assist are met,
The braking device (41) is provided with a determination unit (77) that compares a predetermined rate of increase with a threshold value corresponding to the predetermined rate of increase, and the assist start condition is determined based on the frequency with which the determination unit (77) determines that the threshold value is equal to or greater than the threshold value.
The moving body is a saddle-type vehicle (10) equipped with front wheels (13) and rear wheels (15), and the front wheels (13) and rear wheels (15) are provided with a front wheel braking device (51) and a rear wheel braking device (53), respectively.
The assist start conditions include a first assist start condition for starting the brake assist control for the front wheel braking device (51) and a second assist start condition for starting the brake assist control for the rear wheel braking device (53).
The conditions for initiating the first assist and the conditions for initiating the second assist are different.
A braking force control device characterized by the following: A measuring unit (73) for measuring a predetermined value related to the braking device,
A calculation unit (75) calculates and determines the rate of increase of the predetermined value,
A determination unit (77) compares the rate of increase of the predetermined value measured by the measurement unit (73) with a predetermined threshold ,
The system includes a counting unit (79) that measures the frequency with which the determination unit (77) determines that the rate of increase of the predetermined value within a predetermined period has exceeded the threshold ,
The braking force control device according to feature 1 . The braking force control device according to claim 1 or 2, characterized in that the predetermined value relating to the braking device (41) is the master cylinder pressure of the braking device (41). The braking force control device according to claim 1 or 2, characterized in that the predetermined value is the amount of operation of the brake lever (49). The braking force control device according to claim 3, characterized in that the assist initiation condition is determined based on the frequency that occurs when the master cylinder pressure is between a predetermined lower threshold and a predetermined upper threshold. The braking force control device according to claim 1, characterized in that, when comparing the first frequency, which is the first assist initiation condition, with the second frequency, which is the second assist initiation condition, the first frequency is greater than the second frequency. The braking force control device according to claim 1 or claim 6, characterized in that the front wheel braking device (51) is instructed to apply braking force by a brake lever (38) operated by the driver's hand, and the rear wheel braking device (53) is instructed to apply braking force by a brake pedal (36) operated by the driver's foot. A saddle-type vehicle equipped with a braking force control device (59) as described in claim 1 or 2 .