Vehicle brake control system

Abstract

The present invention provides a vehicle brake control device that can appropriately perform brake assist control and decelerate the vehicle when the driver applies the brakes. [Solution] The vehicle brake control device comprises a first brake operator for operating the first brake, a second brake operator for operating the second brake, a second detection device for detecting a second operation amount corresponding to the operation of the second brake operator, an external information acquisition device for acquiring external information about the vehicle's surroundings, and a control unit. The control unit is capable of performing deceleration control to slow down the vehicle based on a target deceleration of the vehicle set based on external information and a vehicle deceleration obtained by calculation, etc. If the operating conditions for deceleration control are met (S4:Yes) and the second operation amount is equal to or greater than the first threshold (S3:Yes), the control unit performs brake assist control to slow down the vehicle with a deceleration corresponding to the second operation amount (S5).

Description

Technical Field

[0001] The present invention relates to a vehicle brake control device.

Background Art

[0002] Conventionally, as a vehicle brake control device, one that generates braking force according to a driver's input is known (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] An object of the present invention is to provide a vehicle brake control device that can appropriately perform brake assist control and decelerate a vehicle when a driver performs a braking operation.

[0005] To solve the above problems, a vehicle brake control device according to the present invention includes a first brake operator for operating a first brake that brakes a first wheel, a second brake operator for operating a second brake that brakes a second wheel, a first detection device that detects a first operation amount that varies according to the operation of the first brake operator, a second detection device that detects a second operation amount that varies according to the operation of the second brake operator, an external information acquisition device that acquires external information around the vehicle, and a control unit. The control unit is capable of executing deceleration control to decelerate the vehicle based on a target deceleration of the vehicle set based on the external information and a vehicle deceleration obtained by detection or calculation. When the operating condition of the deceleration control is satisfied and the second operation amount is greater than or equal to a first threshold value, the control unit executes brake assist control to decelerate the vehicle at a deceleration corresponding to the second operation amount.

[0006] With this configuration, if the operating conditions for deceleration control are met while the second brake lever is being operated, brake assist control based on the operation of the second brake lever is executed, thereby assisting the driver's operation and decelerating the vehicle.

[0007] Furthermore, the control unit can calculate the distance between the vehicle and an obstacle in front of the vehicle, and the relative speed, which is the vehicle's speed relative to the obstacle, based on external information. The operating conditions for deceleration control may be that the distance is less than or equal to a first distance threshold, and the absolute value of the relative speed is greater than or equal to a first speed threshold.

[0008] This configuration allows for appropriate deceleration control based on distance and relative velocity.

[0009] The control unit may also calculate the vehicle deceleration based on the wheel speed.

[0010] With this configuration, the control unit calculates the vehicle deceleration, eliminating the need for sensors or other devices to detect vehicle deceleration.

[0011] Furthermore, the vehicle brake control device may include a first detection device that detects a first operating amount that fluctuates due to the operation of a first brake operator, and the control unit may perform braking force control that controls the braking force of the second brake based on the first operating amount when the first operating amount is greater than or equal to a second threshold.

[0012] With this configuration, braking force can be generated from both the first brake and the second brake by operating the first brake control.

[0013] Furthermore, the control unit stores a first map and a second map used for braking force control, where the second map is set to produce a greater braking force of the second brake corresponding to the first manipulated amount than the first map. When braking force control is to be performed when the operating conditions for deceleration control are not met, the first map is used to perform the braking force control. When braking force control is to be performed when the operating conditions for deceleration control are met and the second manipulated amount is less than the first threshold, the second map is used to perform the braking force control.

[0014] This configuration allows for appropriate braking force control according to the operating conditions of the deceleration control.

[0015] Furthermore, the first map and the second map are maps that show at least the relationship between a first manipulated variable and a second target deceleration, which is the target deceleration of the vehicle in braking force control. In the first map, the magnitude of the second target deceleration for a predetermined amount of the first manipulated variable is set to a first value, and in the second map, the magnitude of the second target deceleration for a predetermined amount of the first manipulated variable may be set to a second value which is greater than the first value.

[0016] With this configuration, the second target deceleration can be changed even with the same input, enabling appropriate braking force control.

[0017] Furthermore, the first brake may be a mechanical brake that is mechanically connected to the first brake operator, and the second brake may be a hydraulic brake that generates braking force by hydraulic pressure.

[0018] This configuration allows for a reduction in the number of components in the vehicle's brake control device, resulting in a more compact design, compared to, for example, a structure where both the first and second brakes are hydraulic brakes.

[0019] Furthermore, the control unit may control the braking force of the first brake based on the second manipulated variable when the second manipulated variable is equal to or greater than the third threshold.

[0020] According to this configuration, it is possible to generate braking force from the first brake and the second brake by operating at least one of the first brake operator and the second brake operator.

Brief Description of the Drawings

[0021] [Figure 1] It is a diagram showing the configuration of a bar handle type vehicle equipped with a vehicle brake control device according to an embodiment. [Figure 2] It is a flowchart showing the operation of the control unit. [Figure 3] It is a flowchart showing the BA flag setting process. [Figure 4] It is a flowchart showing the warning flag setting process. [Figure 5] It is a map showing the relationship between the vehicle body speed, the first distance threshold, and the second distance threshold.

Modes for Carrying Out the Invention

[0022] Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. As shown in FIG. 1, a motorcycle MC, which is a bar handle type vehicle, includes a rear wheel WR as an example of a first wheel, a front wheel WF as an example of a second wheel, an engine ENG, a transmission TM, and a vehicle brake control device C.

[0023] The engine ENG is a drive source for driving the motorcycle MC. The engine ENG is connected to the rear wheel WR via the transmission TM. That is, in the motorcycle MC of the present embodiment, the rear wheel WR is a driving wheel and the front wheel WF is a driven wheel. The engine ENG is provided with a throttle sensor 54 for detecting the opening degree of the throttle valve of the engine ENG. The opening degree of the throttle valve increases as the operation amount of the accelerator AC increases. The transmission TM is a mechanism that shifts the driving force of the engine ENG and transmits it to the rear wheel WR, and a speed detection sensor 52 is provided near its output shaft.

[0024] The speed detection sensor 52 is a sensor (so-called speedometer sensor) that detects the wheel speed of the rear wheel WR, and detects the wheel speed corresponding to the speed displayed on a speedometer (not shown). The speed detection sensor 52 has a different detection method than the wheel speed sensor 51 that detects the wheel speed of the front wheel WF. The wheel speed sensor 51 is a sensor that generates pulse waves in conjunction with the rotation of the wheel.

[0025] The vehicle brake control device C comprises a brake system BF for the front wheels WF, a brake system BR for the rear wheels WR, an angle sensor 53 as an example of a first detection device, a second angle sensor 58 as an example of a second detection device, a camera 55 as an example of an external information acquisition device, an HMI 56 as a notification device, an IMU 57 as a vehicle state detection device, and a control unit 100.

[0026] The brake system BF mainly consists of a front brake lever LF as an example of a second brake operator, a master cylinder MF, a hydraulic unit 10, a front brake 20F as an example of a second brake, a pipe 30 connecting the master cylinder MF and the input port 11a of the hydraulic unit 10, and a pipe 40 connecting the output port 11b of the hydraulic unit 10 and the front brake 20F.

[0027] The front brake lever LF is an operating lever for operating the front brake 20F. It is located on the right side of the handlebars of the motorcycle MC and can be operated with the driver's right hand. The front brake lever LF is connected to the front brake 20F via the master cylinder MF, piping 30, hydraulic unit 10, and piping 40. The master cylinder MF is a device that outputs hydraulic pressure corresponding to the amount of movement of the front brake lever LF.

[0028] The front brake 20F is a brake that brakes the front wheel WF. The front brake 20F is a hydraulic brake that generates braking force by hydraulic pressure. The front brake 20F mainly consists of a brake rotor 21, brake pads (not shown), and a wheel cylinder 23 that generates braking force by pressing the brake pads against the brake rotor 21 using hydraulic pressure output from the master cylinder MF.

[0029] The hydraulic unit 10 is a unit that generates braking force for the front brake 20F by applying hydraulic pressure to the front brake 20F. The hydraulic unit 10 is composed of a pump body 11, which is a base body having an oil passage (hydraulic passage) through which brake fluid flows, and various electromagnetic valves and the like are arranged on it. Normally, the input port 11a to the output port 11b of the pump body 11 are connected by an oil passage, so that the hydraulic pressure output from the master cylinder MF is transmitted to the front brake 20F.

[0030] A pressure regulating valve 7 is provided on the hydraulic path connecting the input port 11a and the output port 11b. This valve changes the hydraulic pressure applied to the front brake 20F according to the value of the indicative current output from the control unit 100. The pressure regulating valve 7 is a normally open proportional solenoid valve and can adjust the difference in hydraulic pressure between its upstream and downstream sides according to the value of the indicative current. Specifically, the pressure regulating valve 7 is configured such that the larger the indicative current value, the greater the difference in hydraulic pressure between the upstream and downstream sides of the pressure regulating valve 7. A check valve 7a is provided in parallel with the pressure regulating valve 7, which allows flow only to the output port 11b side.

[0031] An inlet valve 1, which is a normally open solenoid valve, is installed in the hydraulic path between the pressure regulating valve 7 and the output port 11b. A check valve 1a is provided in parallel with the inlet valve 1, which allows flow only to the pressure regulating valve 7 side.

[0032] A recirculating hydraulic passage 19B is provided from the hydraulic passage between the output port 11b and the inlet valve 1, connecting to the hydraulic passage between the pressure regulating valve 7 and the inlet valve 1 via an outlet valve 2 consisting of a normally closed solenoid valve.

[0033] On this recirculating hydraulic pressure passage 19B, a reservoir 3 for temporarily absorbing excess brake fluid, a check valve 3a, a pump 4, and an orifice 4a are arranged in order from the outlet valve 2 side. The check valve 3a is positioned to allow flow only toward the hydraulic pressure passage between the pressure regulating valve 7 and the inlet valve 1. The pump 4 is driven by a motor 6 and is provided to generate pressure toward the hydraulic pressure passage between the pressure regulating valve 7 and the inlet valve 1. The orifice 4a attenuates the pressure pulsation of the brake fluid discharged from the pump 4 and the pulsation generated by the operation of the pressure regulating valve 7.

[0034] The inlet hydraulic pressure passage 19A, which connects the input port 11a and the pressure regulating valve 7, and the section between the check valve 3a and the pump 4 in the return hydraulic pressure passage 19B are connected by the suction hydraulic pressure passage 19C. A mechanical suction valve 8 is installed in the suction hydraulic pressure passage 19C.

[0035] The suction valve 8 switches between opening and closing the suction fluid pressure passage 19C. The suction valve 8 is normally closed and is configured to open based on the difference between the hydraulic pressure of the working fluid on the master cylinder MF side and the hydraulic pressure of the working fluid on the suction port side of the pump 4, which becomes negative pressure when the pump 4 is operating.

[0036] In the hydraulic unit 10 configured as described above, under normal circumstances, no power is supplied to each solenoid valve. The brake fluid pressure introduced from the input port 11a passes through the pressure regulating valve 7 and the inlet valve 1 to the output port 11b, and is directly applied to the front brake 20F. When it is necessary to reduce the excessive brake fluid pressure of the front brake 20F, such as when performing anti-lock brake control, the inlet valve 1 is closed and the outlet valve 2 is opened, allowing the brake fluid to flow to the reservoir 3 through the return fluid pressure passage 19B, thereby draining the brake fluid from the front brake 20F. Furthermore, when pressurizing the front brake 20F with the pump 4, driving the motor 6 opens the suction valve 8, allowing brake fluid to be actively supplied to the front brake 20F by the pressure applied by the pump 4. In addition, if it is necessary to adjust the degree of pressurization of the front brake 20F, this can be done by adjusting the current flowing to the pressure regulating valve 7.

[0037] The brake system BR mainly consists of a rear brake lever LR as an example of a first brake operator, an angle sensor 53, a rear brake 20R as an example of a first brake, and a wire W connecting the rear brake lever LR and the rear brake 20R.

[0038] The rear brake lever LR is the operating lever for the rear brake 20R. It is located on the left side of the handlebars of the motorcycle MC and can be operated with the rider's left hand. The rear brake lever LR is mechanically connected to the rear brake 20R via wire W.

[0039] The angle sensor 53 is a sensor for detecting the operating angle of the rear brake lever LR as an example of a first operating amount. The operating angle of the rear brake lever LR changes depending on the operation of the rear brake lever LR.

[0040] The second angle sensor 58 is a sensor for detecting the operating angle of the front brake lever LF, which is an example of a second operating amount. The operating angle of the front brake lever LF changes depending on the operation of the front brake lever LF. By detecting the change in the operating angle of the front brake lever LF, it is possible to determine whether or not the front brake lever LF has been operated.

[0041] The rear brake 20R is a brake that stops the rear wheel WR, and is a mechanical brake that operates when the force applied when the rear brake lever LR is squeezed is transmitted via wire W. The rear brake 20R cannot be operated with the front brake lever LF. The rear brake 20R is, for example, a drum brake and has a drum 25, brake shoes (not shown), and a return spring.

[0042] The drum 25 is rotatable in conjunction with the rear wheel WR. The brake shoe is rotatable between a contact position where it contacts the inner surface of the drum 25 and a separated position where it is away from the inner surface of the drum 25. The return spring biases the brake shoe from the contact position to the separated position. When the driver squeezes the rear brake lever LR, the wire W is pulled by the rear brake lever LR, causing the brake shoe to rotate from the separated position to the contact position against the biasing force of the return spring.

[0043] Camera 55 is a device that acquires external information about the surroundings of the motorcycle MC. Camera 55 captures images of the area in front of the motorcycle MC and outputs the captured image information as external information to the control unit 100.

[0044] HMI56 is a "Human Machine Interface" and is a device that provides notifications to the driver to prompt them to slow down the motorcycle (MC). HMI56 is equipped with a monitor that can display the distance from the motorcycle (MC) to an obstacle in front of the motorcycle (MC), and a lamp that can emit warning light.

[0045] The IMU57 is an "Inertial Measurement Unit" and is a device that measures the state of a motorcycle MC, including its attitude. To detect three-dimensional inertial motion (translational and rotational motion in three axes), the IMU57 is equipped with an acceleration sensor to detect translational motion and an angular velocity sensor to detect rotational motion. The IMU57 outputs the detected information to the control unit 100.

[0046] The control unit 100 is configured to include, for example, a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), input / output circuits, etc. The control unit 100 controls the hydraulic unit 10 by performing various calculations based on inputs from the wheel speed sensor 51, speed detection sensor 52, angle sensors 53, 58, throttle sensor 54, camera 55 and IMU 57, as well as programs and data stored in ROM.

[0047] The control unit 100 can perform deceleration control to slow down the vehicle based on the target deceleration of the vehicle set based on external information and the vehicle deceleration obtained by detection or calculation. The control unit 100 can perform automatic brake control, braking force control and brake assist control as deceleration control.

[0048] Furthermore, the control unit 100 has the function of calculating the distance D between the motorcycle MC and an obstacle in front of the motorcycle MC, and the relative speed VD, which is the speed of the motorcycle MC relative to the obstacle, based on the image information acquired from the camera 55. The control unit 100 executes deceleration control on the condition that the distance D is less than or equal to the first distance threshold Dth1 and the absolute value of the relative speed VD is greater than or equal to the first speed threshold. In other words, the first condition is the operating condition for deceleration control.

[0049] Automatic brake control is a control system that decelerates the motorcycle MC based on the requested deceleration Dc of the motorcycle MC, which is set based on image information acquired from the camera 55, and the actual vehicle deceleration (hereinafter also referred to as "actual deceleration Dr"). Here, the actual deceleration Dr can be calculated, for example, based on the wheel speed acquired from the wheel speed sensor 51. The control unit 100 executes automatic brake control on the condition that neither the brake lever LF nor LR is operated.

[0050] In this embodiment, the control unit 100 calculates the relative speed VD by subtracting the speed of the motorcycle MC from the speed of the obstacle ahead. Therefore, when the motorcycle MC approaches the obstacle ahead, the relative speed VD is calculated as a negative value. The control unit 100 determines whether the absolute value of the relative speed VD is greater than or equal to the first speed threshold (a positive value) by determining whether the relative speed VD is less than or equal to the negative speed threshold VDth.

[0051] The control unit 100 executes notification by the HMI 56 on the condition that the distance D is less than or equal to the second distance threshold Dth2, which is greater than the first distance threshold Dth1, and the absolute value of the relative velocity VD is greater than or equal to the second velocity threshold. In this embodiment, the first velocity threshold and the second velocity threshold are set to the same value. Therefore, by determining whether the relative velocity VD is less than or equal to the velocity threshold VDth, the control unit 100 also determines whether the absolute value of the relative velocity VD is greater than or equal to the second velocity threshold (a positive value).

[0052] The control unit 100 has a function to set a first distance threshold Dth1 and a second distance threshold Dth2 based on the vehicle speed. The vehicle speed can be calculated, for example, based on the wheel speed obtained from the wheel speed sensor 51.

[0053] Specifically, the control unit 100 stores the map shown in FIG. 6. This map shows the relationship between the vehicle body speeds (V1, V2, V3. Note that V1 < V2 < V3.), the first distance threshold Dth1, and the second distance threshold Dth2. In this map, the magnitude relationship of the values D1, D2, D3 is D1 < D2 < D3, and the magnitude relationship of the values D4, D5, D6 is D4 < D5 < D6.

[0054] That is, the first distance threshold Dth1 and the second distance threshold Dth2 are set to larger values as the vehicle body speed increases. Also, at a predetermined vehicle body speed (for example, any of V1, V2, V3), the second distance threshold Dth2 is larger than the first distance threshold Dth1. That is, D4 > D1, D5 > D2, D6 > D3.

[0055] The values D1 to D6 of this map are set based on TTC (Time To Collision). Here, TTC refers to the remaining time Tr until a collision when the motorcycle MC and the obstacle ahead maintain their current speeds. The remaining time Tr is calculated from the following formula (1). Tr = D ÷ (Vs - Vf) ···(1) D: The distance between the obstacle in front of the motorcycle MC and the motorcycle MC Vs: The speed of the motorcycle MC Vf: The speed of the obstacle ahead

[0056] The braking force control is a control that controls the braking force of the front brake 20F based on the operation angle θr when the operation angle θr of the rear brake lever LR is greater than or equal to the second threshold value θth2.

[0057] Specifically, the control unit 100 executes the braking force control by driving the motor 6 and controlling the pressure regulating valve 7. The control unit 100 calculates the value of the command current value output to the pressure regulating valve 7 based on the operation angle θ and the actual vehicle body deceleration (hereinafter also referred to as "actual deceleration Dr"). The control unit 100 increases the value of the command current value as the operation angle θ increases, and increases the value of the command current value as the magnitude of the actual deceleration Dr decreases.

[0058] The control unit 100 stores a first map and a second map used for braking force control. The first map and the second map are maps that show at least the relationship between the operating angle θr and the second target deceleration, which is the target deceleration of the vehicle in braking force control. In both the first map and the second map, the magnitude of the second target deceleration increases as the operating angle θr increases.

[0059] Furthermore, in the first map, the magnitude of the second target deceleration for a predetermined amount of operating angle θr is set to a first value, while in the second map, the magnitude of the second target deceleration for a predetermined amount of operating angle θr is set to a second value, which is larger than the first value. Specifically, the graph of the second target deceleration in the second map is offset to the side where the magnitude of deceleration is larger compared to the graph of the second target deceleration in the first map. In other words, the second map is set to produce a larger braking force from the front brake 20F in response to the operating angle θr than the first map.

[0060] When the control unit 100 executes braking force control when the operating conditions for deceleration control are not met, it uses the first map to execute braking force control. When the operating conditions for deceleration control are met and the operating angle θf of the front brake lever LF is less than the first threshold θth1, the control unit 100 executes braking force control using the second map to execute braking force control. In the following description, braking force control using the first map will also be referred to as "first braking force control," and braking force control using the second map will also be referred to as "second braking force control."

[0061] Brake assist control is a control system that decelerates the vehicle at a deceleration rate corresponding to the operating angle θf when the operating conditions for deceleration control are met and the operating angle θf of the front brake lever LF is greater than or equal to a first threshold θth1. For example, the control unit 100 sets a target hydraulic pressure for the front brake 20F by multiplying the operating angle θf by a predetermined conversion coefficient, and controls the motor 6 and pressure regulating valve 7 so that the hydraulic pressure of the front brake 20F becomes the target hydraulic pressure.

[0062] Next, the operation of the control unit 100 will be described in detail. The control unit 100 constantly repeats the process shown in Figure 2.

[0063] In the process shown in Figure 2, the control unit 100 first determines whether or not there has been an operation of either the brake lever LF or LR (hereinafter also referred to as "brake operation") (S1). Specifically, in step S1, the control unit 100 determines whether or not there has been a brake operation by determining whether the operation angles θf and θr are greater than or equal to thresholds. The threshold compared with θf in step S1 may be the same value as the first threshold θth1, or it may be a different value from the first threshold θth1, for example, a value smaller than the first threshold θth1. Similarly, the threshold compared with θr may be the same value as the second threshold θth2, or it may be a different value from the second threshold θth2, for example, a value smaller than the second threshold θth2. If it is determined in step S1 that there has been a brake operation (Yes), the control unit 100 determines whether or not there has been a request for anti-lock brake control (hereinafter also referred to as "ABS request") (S2).

[0064] If it is determined in step S2 that there is no ABS request (No), the control unit 100 determines whether the front brake lever LF is being operated by determining whether the operating angle θf is greater than or equal to the first threshold θth1 (S3). If it is determined in step S3 that the front brake lever LF is being operated (Yes), the control unit 100 determines whether the brake assist flag (hereinafter also referred to as the "BA flag") for executing brake assist control (hereinafter also referred to as "BA control") is on, i.e., set (S4).

[0065] If the control unit 100 determines in step S4 that the BA flag is on (Yes), it executes BA control (S5) and terminates the process. If the control unit 100 determines in step S4 that the BA flag is not on (No), it terminates the process without performing BA control.

[0066] If it is determined in step S3 that the front brake lever LF is not being operated (No), the control unit 100 determines whether or not there is a request for braking force control (S6). Specifically, in step S6, the control unit 100 determines whether or not the operating angle θr of the rear brake lever LR is greater than or equal to the second threshold θth2, and if it is determined that θr ≥ θth2, it determines that there is a request for braking force control.

[0067] If step S6 determines that there is a request for braking force control (Yes), the control unit 100 determines whether the BA flag is on or off (S7). If step S7 determines that the BA flag is not on (No), the control unit 100 executes the first braking force control using the first map (S8) and terminates this process. If step S7 determines that the BA flag is on (Yes), the control unit 100 executes the second braking force control using the second map (S9) and terminates this process.

[0068] If it is determined in step S2 that there is an ABS request (Yes), the control unit 100 executes ABS control (S10) and terminates this process. If it is determined in step S1 that there is no brake operation (No), the control unit 100 determines whether or not there is a request for automatic brake control (hereinafter also referred to as "automatic brake") (S11).

[0069] If the control unit 100 determines in step S11 that there is a request for automatic braking (Yes), it performs automatic braking (S12) and terminates this process. If the control unit 100 determines in step S11 that there is no request for automatic braking (No), it terminates this process without performing automatic braking.

[0070] The control unit 100 continuously and repeatedly executes the BA flag setting process shown in Figure 3 and the warning flag setting process shown in Figure 4. First, the warning flag setting process shown in Figure 4 will be explained.

[0071] As shown in Figure 4, in the warning flag setting process, the control unit 100 first sets a first distance threshold Dth1 and a second distance threshold Dth2 according to the vehicle speed using the map shown in Figure 5 (S21). After step S21, the control unit 100 determines, based on the image information acquired from the camera 55, whether or not an object in front of the motorcycle MC is a controlled object that meets the operating conditions for deceleration control (S22).

[0072] Specifically, for example, if the image acquired from camera 55 is an image of an uphill slope, the system determines that the uphill slope is not the object to be controlled. Also, if the image acquired from camera 55 is of a car, the system determines that the car is the object to be controlled.

[0073] If, in step S22, it is determined that the object captured by the camera 55 is the object to be controlled (Yes), the control unit 100 calculates the distance D and relative velocity VD based on the image information acquired from the camera 55, and determines whether the distance D is less than or equal to the second distance threshold Dth2 and the relative velocity VD is less than or equal to the velocity threshold VDth (S23). If, in step S23, it is determined that D ≤ Dth2 and VD ≤ VDth (Yes), the control unit 100 turns on, or sets, the warning flag Low (S24).

[0074] After step S24, the control unit 100 displays the distance D on the monitor of the HMI 56 and makes the lamp of the HMI 56 blink (S25). After step S25, the control unit 100 determines whether the distance D is less than or equal to the first distance threshold Dth1 and the relative velocity VD is less than or equal to the velocity threshold VDth (S26).

[0075] If step S26 determines that D ≤ Dth1 and VD ≤ VDth (Yes), the control unit 100 turns on the warning flag High (S27) and terminates the process. If step S22 or step S23 determines No, the control unit 100 turns off the warning flag Low and the warning flag High, stops the HMI 56 (S28), and terminates the process. If step S26 determines No, the control unit 100 terminates the process while keeping the warning flag Low.

[0076] As shown in Figure 3, in the BA flag setting process, the control unit 100 first determines whether the warning flag High is on (S41). If it is determined in step S41 that the warning flag High is on (Yes), the control unit 100 determines whether a brake operation has occurred, that is, whether either the brake lever LF or LR has been operated (S42). The determination in step S42 can be performed, for example, in the same way as in step S1.

[0077] If step S42 determines that a brake operation has occurred (Yes), the control unit 100 turns on the BA flag (S43) and terminates this process. If step S41 or step S42 determines No, the control unit 100 turns off the BA flag (S44) and terminates this process.

[0078] Next, a specific example of the operation of the control unit 100 will be described. When the conditions in step S26 are met while the motorcycle MC is in motion, the control unit 100 turns on the warning flag High (S27). At this time, if the driver is operating the brakes, the control unit 100 turns on the BA flag in the BA flag setting process shown in Figure 3 (S41-S43).

[0079] If the driver is operating the brakes and the warning flag High is on, and the BA flag is also on, the control unit 100 executes either BA control or second braking force control as shown in Figure 2. Specifically, when the driver is operating only the front brake lever LF, or when both brake levers LF and LR are operating, the control unit 100 determines Yes in step S3, then determines Yes in step S4, and executes BA control (S5). When the driver is operating only the rear brake levers LR, the control unit 100 determines No in step S3, then determines Yes in both steps S6 and S7, and executes second braking force control (S9).

[0080] As described above, the following effects can be obtained according to this embodiment. When the operating conditions for deceleration control are met and the BA flag is turned on while the front brake lever LF is being operated, BA control based on the operation of the front brake lever LF is executed, thereby assisting the driver's operation and slowing down the vehicle.

[0081] Since the operating conditions for deceleration control are defined as the distance being less than or equal to the first distance threshold and the absolute value of the relative velocity being greater than or equal to the first velocity threshold, deceleration control can be appropriately executed based on distance and relative velocity.

[0082] Since the control unit 100 calculates the vehicle deceleration, sensors or other devices for detecting vehicle deceleration become unnecessary.

[0083] The control unit 100 performs braking force control that controls the braking force of the front brake 20F based on the operating angle θr of the rear brake lever LR. Therefore, by operating the rear brake lever LR, braking force can be generated from both the front brake 20F and the rear brake 20R.

[0084] The control unit 100 selects between the first braking force control and the second braking force control according to the operating conditions of the deceleration control, so that appropriate braking force control can be performed according to the operating conditions of the deceleration control.

[0085] In the first map, the magnitude of the second target deceleration for a predetermined amount of the first control input is set to a first value, and in the second map, the magnitude of the second target deceleration for a predetermined amount of the first control input is set to a second value which is greater than the first value. Therefore, the second target deceleration can be changed even with the same control input, enabling appropriate braking force control.

[0086] Since the rear brake 20R is a mechanical brake and the front brake 20F is a hydraulic brake, the number of parts in the vehicle brake control device C can be reduced and the device can be made smaller compared to, for example, a structure in which both the first and second brakes are hydraulic brakes.

[0087] When the warning flag High is activated while only the rear brake levers (LR) are being operated, the second braking force control provides greater braking force than the normal first braking force control. Therefore, even an inexperienced driver who cannot operate the front brake lever (LF) can generate greater braking force than usual by operating only the rear brake levers (LR).

[0088] The present invention is not limited to the embodiments described above, and can be used in various forms as illustrated below.

[0089] In the above embodiment, the first brake was a mechanical brake and the second brake was a hydraulic brake, but for example, both the first and second brakes may be hydraulic brakes. In this case, the control unit of the vehicle brake control device may control the braking force of the first brake based on the second operating amount when the second operating amount is greater than or equal to the third threshold.

[0090] With this configuration, operating either the first brake lever or the second brake lever will activate both the first and second brakes.

[0091] Wheel speed can also be detected using GPS (Global Positioning System) or similar methods.

[0092] The manipulated variable can be any parameter that changes as a result of operating the brake lever. For example, if the hydraulic pressure changes as a result of operating the brake lever, then the manipulated variable may be the hydraulic pressure. In this case, the detection device may be a sensor that detects hydraulic pressure.

[0093] The color of the warning light may be changed depending on whether the warning flag Low is on or High is on. Specifically, for example, the warning light may be yellow when the warning flag Low is on, and red when the warning flag High is on.

[0094] The external information acquisition device may be a distance sensor capable of detecting the distance to an obstacle in front of the vehicle.

[0095] The actual deceleration Dr may be detected by an acceleration sensor or the like.

[0096] The first speed threshold and the second speed threshold may be different values. The first speed threshold and the second speed threshold may each be set according to the vehicle speed.

[0097] In the above embodiment, the operating angle of the brake lever was used as an example of the operating amount, but the operating amount may also be, for example, the stroke amount detected by a stroke sensor that detects the stroke of an operating element such as a brake lever or foot brake, or the distance detected by a distance sensor such as an infrared sensor that detects the distance between the operating element and a support member that movably supports the operating element.

[0098] The second brake is not limited to a hydraulic brake; for example, it may be an electromagnetic brake. The first brake is not limited to a mechanical brake; for example, it may be an electromagnetic brake or a hydraulic brake. Furthermore, the second brake may be used for the rear wheels, and the first brake for the front wheels.

[0099] The vehicle equipped with the first and second brakes is not limited to motorcycles (MC), but can be any type of vehicle. For example, the vehicle may be a handlebar-operated vehicle. A handlebar-operated vehicle may be, for example, a three-wheeled or four-wheeled vehicle.

[0100] The brake control is not limited to a lever; it may also be a foot brake pedal, for example.

[0101] The intake valve may be a normally closed solenoid valve.

[0102] The power source may be a motor used to move the vehicle.

[0103] The elements described in the above embodiments and modifications may be implemented in any combination.

Claims

[Claim 1] A first brake control element for operating the first brake that brakes the first wheel, A second brake control element for operating the second brake that brakes the second wheel, A first detection device for detecting a first manipulated amount that changes as a result of operating the first brake control element, A second detection device for detecting a second operating amount that changes as a result of operating the second brake operator, An external information acquisition device that acquires external information about the surroundings of the vehicle, It comprises a control unit and, The control unit, Based on the aforementioned external information, it is possible to perform deceleration control to slow down the vehicle, based on the target deceleration of the vehicle set and the vehicle deceleration obtained by detection or calculation. If the operating conditions for the deceleration control are met and the second manipulated amount is equal to or greater than the first threshold, brake assist control is executed to decelerate the vehicle at a deceleration rate corresponding to the second manipulated amount. A vehicle brake control device characterized in that, when the second manipulated amount is less than the first threshold and the first manipulated amount is equal to or greater than the second threshold, it performs brake force control to control the braking force of the second brake based on the first manipulated amount.

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