Control device and control method

Abstract

Increase the amount of electricity generated through regenerative power generation. [Solution] In the control device and control method according to the present invention, the execution unit of the control device performs a regenerative braking operation to brake a saddle-type vehicle using regenerative braking with an electric motor, and the execution unit performs a hydraulic pressure control operation to control the hydraulic pressure control unit so that the wheel cylinder pressure becomes lower than the master cylinder pressure, which is the pressure of the brake fluid in the master cylinder, while performing a regenerative braking force increasing operation to increase the regenerative braking force (FR), which is the braking force acting on the saddle-type vehicle by the regenerative braking operation.

Description

Technical Field

[0001] This disclosure relates to a control device and a control method capable of increasing the electric power obtained by regenerative power generation.

Background Art

[0002] For a straddle-type vehicle, as a mechanism for controlling the braking force generated on the wheels, for example, a hydraulic control unit that controls the wheel cylinder pressure, which is the pressure of the brake fluid in the wheel cylinder, is provided (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, there is a straddle-type vehicle equipped with an electric motor as a drive source. In such a straddle-type vehicle, in addition to braking the straddle-type vehicle by the wheel cylinder pressure controlled by the hydraulic control unit, it is also possible to brake the straddle-type vehicle by regenerative braking using the electric motor. Regenerative braking is generated by causing the electric motor to perform regenerative power generation. And in such a straddle-type vehicle, it is desired to obtain more electric power by regenerative power generation.

[0005] The present invention has been made against the background of the above problems, and aims to obtain a control device and a control method capable of increasing the electric power obtained by regenerative power generation.

Means for Solving the Problems

[0006] The control device according to the present invention is a control device for controlling the behavior of a saddle-type vehicle, which comprises a master cylinder connected to a brake operation unit, a wheel cylinder, a hydraulic pressure control unit connected to the wheel cylinder and controlling the wheel cylinder pressure, which is the pressure of the brake fluid in the wheel cylinder, and an electric motor as a drive source, and includes an execution unit that performs a regenerative braking operation to brake the saddle-type vehicle by regenerative braking using the electric motor, and the execution unit performs a hydraulic pressure control operation to control the hydraulic pressure control unit so that the wheel cylinder pressure becomes lower than the master cylinder pressure, which is the pressure of the brake fluid in the master cylinder, when the rider of the saddle-type vehicle is performing a brake operation using the brake operation unit, and also performs a regenerative braking force increasing operation to increase the regenerative braking force, which is the braking force acting on the saddle-type vehicle by the regenerative braking operation.

[0007] The control method according to the present invention is a control method for controlling the behavior of a saddle-type vehicle comprising a master cylinder connected to a brake operation unit, a hydraulic control unit connected to a wheel cylinder and controlling the wheel cylinder pressure, which is the pressure of the brake fluid in the wheel cylinder, and an electric motor as a drive source, wherein the execution unit of the control device performs a regenerative braking operation to brake the saddle-type vehicle by regenerative braking using the electric motor, and the execution unit performs a hydraulic control operation to control the hydraulic control unit so that the wheel cylinder pressure becomes lower than the master cylinder pressure, which is the pressure of the brake fluid in the master cylinder, while performing a regenerative braking force increase operation to increase the regenerative braking force, which is the braking force acting on the saddle-type vehicle by the regenerative braking operation, under the condition that the rider of the saddle-type vehicle is performing a brake operation using the brake operation unit. [Effects of the Invention]

[0008] In the control device and control method according to the present invention, the execution unit of the control device performs a regenerative braking operation to brake a saddle-type vehicle using regenerative braking with an electric motor. The execution unit performs a hydraulic control operation to control the hydraulic control unit so that the wheel cylinder pressure is lower than the master cylinder pressure, which is the pressure of the brake fluid in the master cylinder, while the execution unit performs a regenerative braking force increase operation to increase the regenerative braking force, which is the braking force acting on the saddle-type vehicle by the regenerative braking operation, while the wheel cylinder pressure is lower than the master cylinder pressure, which is the pressure of the brake fluid in the master cylinder. As a result, when braking is performed, the proportion of regenerative braking force in the total braking force acting on the saddle-type vehicle can be increased, and more electricity can be obtained by regenerative power generation. Therefore, the amount of electricity obtained by regenerative power generation can be increased. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing the general configuration of a saddle-type vehicle according to an embodiment of the present invention. [Figure 2] This is a schematic diagram showing the general configuration of a brake system for a saddle-type vehicle according to an embodiment of the present invention. [Figure 3] This is a block diagram showing an example of the functional configuration of a control device according to an embodiment of the present invention. [Figure 4] This figure shows an example of the transitions of various state variables in a comparative example. [Figure 5] This flowchart shows an example of the processing flow performed by the control device according to an embodiment of the present invention. [Figure 6] This figure shows an example of the transitions of various state variables in an embodiment of the present invention. [Modes for carrying out the invention]

[0010] The control device and control method according to the present invention will be described below with reference to the drawings.

[0011] Although the following description refers to a control device used in a two-wheeled motorcycle (see saddle-type vehicle 1 in Figure 1), the vehicle controlled by the control device according to the present invention may be a saddle-type vehicle other than a two-wheeled motorcycle. A saddle-type vehicle means a vehicle on which a rider straddles and rides. Examples of saddle-type vehicles include motorcycles (two-wheeled vehicles, three-wheeled vehicles), bicycles, buggies, etc. Motorcycles include examples such as motorcycles and electric scooters. A bicycle means a vehicle that can be propelled on the road by the pedaling force applied by the rider. Bicycles include electric bicycles, etc.

[0012] Furthermore, the configurations and operations described below are merely examples, and the control device and control method according to the present invention are not limited to such configurations and operations.

[0013] Furthermore, in the following, identical or similar explanations have been simplified or omitted as appropriate. Also, in each figure, identical or similar components or parts have either had their reference numerals omitted or the same reference numerals have been used. In addition, detailed structures have been simplified or omitted as appropriate.

[0014] <Configuration of saddle-type vehicles> The configuration of the saddle-type vehicle 1 according to an embodiment of the present invention will be described below.

[0015] Figure 1 is a schematic diagram showing the general configuration of a saddle-type vehicle 1. The saddle-type vehicle 1 is a two-wheeled motorcycle that corresponds to an example of a saddle-type vehicle according to the present invention. As shown in Figure 1, the saddle-type vehicle 1 comprises an electric motor 11, a battery 12, a hydraulic control unit 13, an input device 14, a front wheel speed sensor 15, a rear wheel speed sensor 16, and a control unit (ECU) 20.

[0016] The electric motor 11 is the drive source for the saddle-type vehicle 1, outputting the driving force that acts on the saddle-type vehicle 1. The electric motor 11 is connected to the rear wheels 3, which are the drive wheels of the saddle-type vehicle 1, and outputs the driving force that is transmitted to the rear wheels 3.

[0017] The battery 12 stores the electric power supplied to the electric motor 11. The battery 12 can charge and discharge electric power. For example, the battery 12 is a secondary battery such as a lithium-ion battery.

[0018] The hydraulic control unit 13 is a unit responsible for the function of controlling the braking force generated on the wheels. For example, the hydraulic control unit 13 is provided on an oil path connecting the master cylinder and the wheel cylinder, and includes components (for example, control valves and pumps) for controlling the pressure of the brake fluid in the wheel cylinder. Details of the brake system 10 including the hydraulic control unit 13 will be described later.

[0019] The input device 14 receives various operations by the rider. The input device 14 is provided on, for example, the handlebar and includes push buttons and the like used for the rider's operations. Information regarding the rider's operations using the input device 14 is output to the control device 20.

[0020] The front wheel speed sensor 15 is a wheel speed sensor that detects the wheel speed of the front wheel 2 (for example, the number of revolutions [rpm] per unit time or the moving distance [km / h] per unit time of the front wheel 2) and outputs the detection result. The front wheel speed sensor 15 may detect other physical quantities that can be substantially converted into the wheel speed of the front wheel 2. The front wheel speed sensor 15 is provided on the front wheel 2.

[0021] The rear wheel speed sensor 16 is a wheel speed sensor that detects the wheel speed of the rear wheel 3 (for example, the number of revolutions [rpm] per unit time or the moving distance [km / h] per unit time of the rear wheel 3) and outputs the detection result. The rear wheel speed sensor 16 may detect other physical quantities that can be substantially converted into the wheel speed of the rear wheel 3. The rear wheel speed sensor 16 is provided on the rear wheel 3.

[0022] The control device 20 controls the behavior of the saddle-type vehicle 1. For example, part or all of the control device 20 is composed of a microcontroller, microprocessor unit, etc. Alternatively, part or all of the control device 20 may be composed of updatable components such as firmware, or it may be a program module executed by commands from a CPU, etc. The control device 20 may be a single unit or it may be divided into multiple units. Details of the control device 20 will be described later.

[0023] Figure 2 is a schematic diagram showing the general configuration of the brake system 10 of the saddle-type vehicle 1. As shown in Figure 2, the brake system 10 comprises a front wheel braking mechanism 31, a rear wheel braking mechanism 32, a first brake operating unit 41, and a second brake operating unit 42. The first brake operating unit 41 is, for example, a brake lever. The front wheel braking mechanism 31 brakes the front wheel 2 in conjunction with at least the first brake operating unit 41. The second brake operating unit 42 is, for example, a brake pedal. The rear wheel braking mechanism 32 brakes the rear wheel 3 in conjunction with at least the second brake operating unit 42. Part of the front wheel braking mechanism 31 and part of the rear wheel braking mechanism 32 are included in the hydraulic control unit 13.

[0024] Each of the front wheel braking mechanisms 31 and the rear wheel braking mechanism 32 includes a master cylinder 51 containing a piston (not shown), a reservoir 52 attached to the master cylinder 51, a brake caliper 53 held on the body of the saddle-type vehicle 1 and having brake pads (not shown), a wheel cylinder 54 provided on the brake caliper 53, a main passage 55 for circulating brake fluid from the master cylinder 51 to the wheel cylinder 54, and a sub-passage 56 for releasing brake fluid from the wheel cylinder 54.

[0025] The master cylinder 51 of the front wheel braking mechanism 31 is connected to the first brake operating unit 41. The master cylinder 51 of the rear wheel braking mechanism 32 is connected to the second brake operating unit 42. The hydraulic control unit 13 is connected to the master cylinder 51 of the front wheel braking mechanism 31 and the master cylinder 51 of the rear wheel braking mechanism 32 via brake fluid piping. Hereinafter, the brake fluid pressure in the master cylinder 51 will also be referred to as the master cylinder pressure.

[0026] Furthermore, the hydraulic control unit 13 is connected to the wheel cylinders 54 of the front wheel braking mechanism 31 and the rear wheel braking mechanism 32 via brake fluid piping. Hereinafter, the brake fluid pressure in the wheel cylinders will also be referred to as the wheel cylinder pressure. The hydraulic control unit 13 controls the wheel cylinder pressure of the front wheel braking mechanism 31 and the rear wheel braking mechanism 32.

[0027] The main flow path 55 is provided with a suction valve (EV) 61. The suction valve 61 is, for example, a solenoid valve that opens when de-energized and closes when energized. The secondary flow path 56 bypasses the main flow path 55 between the wheel cylinder 54 side and the master cylinder 51 side relative to the suction valve 61. The secondary flow path 56 is provided with, in order from the upstream side, a release valve (AV) 62, an accumulator 63, and a pump 64. The release valve 62 is, for example, a solenoid valve that closes when de-energized and opens when energized.

[0028] The hydraulic control unit 13 is also equipped with a motor 71, a first brake operation sensor 81, a second brake operation sensor 82, and a master cylinder pressure sensor 83. The motor 71 drives the pump 64. The first brake operation sensor 81 detects whether or not a brake operation is being performed using the first brake operation unit 41. The second brake operation sensor 82 detects whether or not a brake operation is being performed using the second brake operation unit 42. The master cylinder pressure sensor 83 is provided for each of the front wheel braking mechanism 31 and the rear wheel braking mechanism 32, and detects the master cylinder pressure of each of the front wheel braking mechanism 31 and the rear wheel braking mechanism 32. The master cylinder pressure can be considered an indicator of the amount of brake operation.

[0029] The hydraulic control unit 13 includes components for controlling wheel cylinder pressure, including a suction valve 61, a release valve 62, an accumulator 63, and a pump 64, and a base body 13a on which these components are provided and which has internally formed passages for forming a main passage 55 and a sub-passage 56.

[0030] The base 13a may be formed from a single member or from multiple members. Furthermore, if the base 13a is formed from multiple members, each component may be provided on a different member.

[0031] The operation of the above-mentioned components of the hydraulic control unit 13 and the motor 71 is controlled by the control device 20. This controls the braking force generated on the front wheels 2 by the front wheel braking mechanism 31 and the braking force generated on the rear wheels 3 by the rear wheel braking mechanism 32.

[0032] Under normal conditions (i.e., when the system is set to generate braking force on the wheels in response to the rider's braking operation), the control device 20 opens the engagement valve 61 and closes the release valve 62. In this state, when braking is performed using the first brake operation unit 41, the piston (not shown) of the master cylinder 51 in the front wheel braking mechanism 31 is pushed in, increasing the wheel cylinder pressure, and the brake pads (not shown) of the brake caliper 53 are pressed against the rotor 2a of the front wheel 2, generating braking force on the front wheel 2. Also, when braking is performed using the second brake operation unit 42, the piston (not shown) of the master cylinder 51 in the rear wheel braking mechanism 32 is pushed in, increasing the wheel cylinder pressure, and the brake pads (not shown) of the brake caliper 53 are pressed against the rotor 3a of the rear wheel 3, generating braking force on the rear wheel 3.

[0033] In the above description of the brake system 10 with reference to Figure 2, the example in Figure 2 is merely one example, and the configuration of the brake system 10 is not limited to the example in Figure 2. For example, the hydraulic control unit 13 may control only the braking force generated on either the front wheel 2 or the rear wheel 3. Also, for example, in addition to the main passage 55 and the sub-passage 56, the hydraulic control unit 13 may further include a supply passage that supplies brake fluid from the master cylinder 51 to the sub-passage 56.

[0034] Figure 3 is a block diagram showing an example of the functional configuration of the control device 20. As shown in Figure 3, the control device 20 includes, for example, an acquisition unit 21 and an execution unit 22. The control device 20 also communicates with each device of the saddle-type vehicle 1.

[0035] The acquisition unit 21 acquires information from each device of the saddle-type vehicle 1 and outputs it to the execution unit 22. For example, the acquisition unit 21 acquires information from the input device 14, the front wheel speed sensor 15, the rear wheel speed sensor 16, the first brake operation unit sensor 81, the second brake operation unit sensor 82, and the master cylinder pressure sensor 83. In this specification, information acquisition may include information extraction or generation (e.g., calculation).

[0036] The execution unit 22 performs various controls by controlling the operation of each device of the saddle-type vehicle 1. For example, the execution unit 22 controls the operation of the electric motor 11 and the hydraulic control unit 13. More specifically, for example, the electric motor 11 is directly controlled by a control device other than the control device 20. The execution unit 22 then indirectly controls the operation of the electric motor 11 by, for example, outputting control commands to the other control device. However, the execution unit 22 may also directly control the electric motor 11 without going through the other control device.

[0037] <Operation of the control device> The operation of the control device 20 according to an embodiment of the present invention will be described.

[0038] As described above, the saddle-type vehicle 1 is equipped with an electric motor 11 as a drive source. Therefore, in addition to braking the saddle-type vehicle 1 by the wheel cylinder pressure controlled by the hydraulic control unit 13, the saddle-type vehicle 1 can also be braked by regenerative braking using the electric motor 11.

[0039] Here, the electric motor 11 and the battery 12 are connected via an inverter (not shown). The execution unit 22 controls the power supplied from the battery 12 to the electric motor 11 by controlling the operation of the inverter, and can control the driving force output from the electric motor 11. The execution unit 22 also controls the operation of the inverter to cause the electric motor 11 to perform regenerative power generation, and can charge the battery 12 with the power obtained from regenerative power generation. Regenerative power generation is a type of power generation that obtains electricity by converting the rotational energy of the rear wheels 3, which are the drive wheels, into electrical energy. When regenerative power generation is performed, the rotational energy of the rear wheels 3 is converted into electrical energy, which brakes the saddle-type vehicle 1. This type of braking associated with regenerative power generation is also called regenerative braking. Regenerative braking is produced by causing the electric motor 11 to perform regenerative power generation.

[0040] As described above, the execution unit 22 of the control device 20 can perform a regenerative braking operation to brake the saddle-type vehicle 1 using regenerative braking with the electric motor 11. Specifically, the execution unit 22 performs the regenerative braking operation when the rider's accelerator operation (specifically, the operation of turning the accelerator grip) is released. As a result, the rider can brake the saddle-type vehicle 1 by releasing the accelerator operation with a feeling similar to that of braking the saddle-type vehicle 1 with engine braking in an engine-powered vehicle.

[0041] Figure 4 shows an example of the transitions of various state variables in a comparative example. In Figure 4, time T is plotted on the horizontal axis and various state variables are plotted on the vertical axis, showing the transitions of the various state variables. Specifically, in Figure 4, the various state variables shown are the speed V of the saddle-type vehicle 1, the various braking forces F acting on the saddle-type vehicle 1, the execution state of accelerator operation AO, and the execution state of brake operation BO.

[0042] In Figure 4, the state in which the accelerator operation AO and brake operation BO are performed is indicated by "ON," and the state in which the accelerator operation AO and brake operation BO are released is indicated by "OFF." In addition, Figure 4 shows the various braking forces F as follows: regenerative braking force FR, which is the braking force acting on the saddle-type vehicle 1 due to regenerative braking operation; hydraulic braking force FH, which is the braking force acting on the saddle-type vehicle 1 due to wheel cylinder pressure; and total braking force FT, which is the sum of hydraulic braking force FH and regenerative braking force FR.

[0043] In the comparative example, the execution unit 22 performs regenerative braking when the accelerator operation AO is released, and maintains the regenerative braking force FR at a basically constant level. For example, in the regenerative braking operation, the execution unit 22 maintains the regenerative braking force FR at a level equivalent to engine braking. The execution unit 22 may also appropriately adjust the regenerative braking force FR in, for example, control to stabilize the posture of the saddle-type vehicle 1. The execution unit 22 can adjust the regenerative braking force FR by, for example, controlling the operation of the inverter.

[0044] In the example in Figure 4, the saddle-type vehicle 1 is running with the accelerator pedal AO engaged before time T11. Then, at time T11, the accelerator pedal AO is released and regenerative braking begins. As described above, in the comparative example in Figure 4, the regenerative braking force FR is basically maintained at a constant level during the regenerative braking operation.

[0045] At time T12, following time T11, brake operation BO is initiated. As a result, from time T12 onward, the hydraulic braking force FH increases as the amount of brake operation BO increases. When brake operation BO is performed using the first brake operation unit 41, the hydraulic braking force FH is generated by the front wheel braking mechanism 31. When brake operation BO is performed using the second brake operation unit 42, the hydraulic braking force FH is generated by the rear wheel braking mechanism 32. Furthermore, from time T12 onward, the total braking force FT also increases. Then, at time T13, following time T12, the increase in the hydraulic braking force FH stops as the increase in the amount of brake operation BO stops. Therefore, from time T13 onward, the total braking force FT is maintained at a constant level.

[0046] Here, as described above, regenerative power generation is a method of generating electricity by converting the rotational energy of the rear wheels 3, which are the drive wheels, into electrical energy. Therefore, the upper limit of the amount of electricity that can be generated by regenerative power generation decreases as the speed V decreases to a certain extent. Consequently, the upper limit of the regenerative braking force FR also decreases as the speed V decreases to a certain extent. In the example in Figure 4, at time T14, after time T13, the upper limit of the regenerative braking force FR matches the current value of the regenerative braking force FR. Then, from time T14 onward, the regenerative braking force FR decreases as the upper limit decreases. Consequently, from time T14 onward, the total braking force FT also decreases. At time T15, after time T14, the saddle-type vehicle 1 comes to a stop.

[0047] As described above, in the comparative example, the execution unit 22 maintains the regenerative braking force FR to a force equivalent to engine braking during regenerative braking, for example. In this case, during regenerative braking, the regenerative braking force FR is controlled to a value smaller than the upper limit. Therefore, it is conceivable to increase the power obtained by regenerative power generation by controlling the regenerative braking force FR to a larger value. However, if the regenerative braking force FR is simply increased, the saddle-type vehicle 1 may be braked too strongly, potentially causing discomfort to the rider. Therefore, in this embodiment, while the rider is performing a brake operation BO using the brake operation unit (specifically, the first brake operation unit 41 or the second brake operation unit 42), both the hydraulic braking force FH and the regenerative braking force FR are adjusted to solve the above problem while increasing the power obtained by regenerative power generation. The following describes an example of processing performed by the control device 20 with reference to Figures 5 and 6.

[0048] Figure 5 is a flowchart showing an example of the processing flow performed by the control device 20. The processing flow shown in Figure 5 starts, for example, after the power supply system of the saddle-type vehicle 1 is started. Step S101 in Figure 5 corresponds to the start of the processing flow shown in Figure 5.

[0049] When the processing flow shown in Figure 5 begins, in step S102, the execution unit 22 determines whether or not the brake operation BO has started.

[0050] In step S102, the execution unit 22 determines, for example, whether or not brake operation BO has been started based on the master cylinder pressure. For example, the execution unit 22 may acquire the master cylinder pressure of the front wheel braking mechanism 31 based on the output information of the master cylinder pressure sensor 83 of the front wheel braking mechanism 31. Then, for example, the execution unit 22 can determine that brake operation BO using the first brake operation unit 41 has been started if the master cylinder pressure of the front wheel braking mechanism 31 exceeds a predetermined value. Also, for example, the execution unit 22 may acquire the master cylinder pressure of the rear wheel braking mechanism 32 based on the output information of the master cylinder pressure sensor 83 of the rear wheel braking mechanism 32. Then, for example, the execution unit 22 can determine that brake operation BO using the second brake operation unit 42 has been started if the master cylinder pressure of the rear wheel braking mechanism 32 exceeds a predetermined value.

[0051] In this specification, the output information of the sensor (in the example above, the master cylinder pressure sensor 83) may be the sensor output itself, or it may be information extracted from said output.

[0052] However, the execution unit 22 may determine whether or not brake operation BO has been started based on information other than the master cylinder pressure. In that case, the hydraulic control unit 13 does not need to be provided with a master cylinder pressure sensor 83. For example, the execution unit 22 may determine whether or not brake operation BO using the first brake operation unit 41 has been started based on the output information of the first brake operation unit sensor 81. Alternatively, for example, the execution unit 22 may determine whether or not brake operation BO using the second brake operation unit 42 has been started based on the output information of the second brake operation unit sensor 82. Alternatively, for example, the execution unit 22 may determine whether or not brake operation BO has been started based on the output information of the front wheel speed sensor 15 and the rear wheel speed sensor 16. In this case, the execution unit 22 can, for example, obtain the speed V of the saddle-type vehicle 1 based on the output information of the front wheel speed sensor 15 and the rear wheel speed sensor 16, and determine whether or not brake operation BO has been started based on the change in speed V.

[0053] If it is determined that brake operation BO has not started (step S102 / NO), step S102 is repeated. On the other hand, if it is determined that brake operation BO has started (step S102 / YES), the process proceeds to step S103.

[0054] If the result in step S102 is determined to be YES, in step S103, the execution unit 22 starts the hydraulic pressure control operation and the regenerative braking force adjustment operation.

[0055] The hydraulic control operation is an operation that controls the hydraulic control unit 13 so that the wheel cylinder pressure is lower than the master cylinder pressure. By performing the hydraulic control operation, the hydraulic braking force FH can be reduced compared to when the hydraulic control operation is not performed. The regenerative braking force adjustment operation is an operation that adjusts the regenerative braking force FR. Specifically, in the regenerative braking force adjustment operation, the execution unit 22 adjusts the regenerative braking force FR to compensate for the reduction in hydraulic braking force FH by the hydraulic control unit 13. In particular, the execution unit 22 performs a regenerative braking force increase operation, which increases the regenerative braking force FR, as the regenerative braking force adjustment operation.

[0056] Details of the hydraulic control operation and regenerative braking force adjustment operation will be described later with reference to Figure 6.

[0057] Following step S103, in step S104, the execution unit 22 determines whether the saddle-type vehicle 1 has stopped or whether the brake operation BO has been released.

[0058] The execution unit 22 can determine, for example, whether the saddle-type vehicle 1 has stopped based on the speed V of the saddle-type vehicle 1. The execution unit 22 can also determine, for example, whether the brake operation BO has been released based on the master cylinder pressure. For example, the execution unit 22 can determine whether the brake operation BO using the first brake operation unit 41 has been released based on the master cylinder pressure of the front wheel braking mechanism 31. For example, the execution unit 22 can determine whether the brake operation BO using the second brake operation unit 42 has been released based on the master cylinder pressure of the rear wheel braking mechanism 32. In addition, similar to step S102 described above, the execution unit 22 may also determine whether the brake operation BO has been released based on information other than the master cylinder pressure (for example, the output information of the first brake operation unit sensor 81, the output information of the second brake operation unit sensor 82, or the speed V of the saddle-type vehicle 1).

[0059] If it is determined that the saddle-type vehicle 1 is not stopped and the brake operation BO has not been released (step S104 / NO), step S104 is repeated. On the other hand, if it is determined that the saddle-type vehicle 1 has stopped or the brake operation BO has been released (step S104 / YES), the process proceeds to step S105.

[0060] If the result in step S104 is determined to be YES, in step S105 the execution unit 22 terminates the hydraulic pressure control operation and the regenerative braking force adjustment operation and returns to step S102.

[0061] Figure 6 shows an example of the transitions of various state variables in this embodiment. In Figure 6, as in Figure 4, time T is plotted on the horizontal axis and various state variables are plotted on the vertical axis, showing the transitions of the various state variables.

[0062] As described above, in this embodiment, the execution unit 22 adjusts both the hydraulic braking force FH and the regenerative braking force FR by performing a hydraulic control operation and a regenerative braking force adjustment operation when the rider is performing a brake operation BO using the brake operation unit. Specifically, the execution unit 22 starts the hydraulic control operation and the regenerative braking force adjustment operation when it determines that a brake operation BO has started. Then, in the regenerative braking force adjustment operation, the execution unit 22 first performs a regenerative braking force increase operation to increase the regenerative braking force FR, and then performs a regenerative braking force maintenance operation to maintain the regenerative braking force FR at the upper limit value.

[0063] In the example shown in Figure 6, the saddle-type vehicle 1 is running with the accelerator pedal AO being operated before time T21. Then, at time T21, the accelerator pedal AO is released and regenerative braking is initiated. In this embodiment, when the accelerator pedal AO is released and the brake pedal BO is not being operated, the execution unit 22 maintains the regenerative braking force FR to a force equivalent to engine braking, similar to the comparative example described above.

[0064] At time T22, following time T21, the brake operation BO is initiated. As a result, from time T22 onward, the hydraulic braking force FH increases as the amount of brake operation BO increases. As described above, when the brake operation BO is performed using the first brake operation unit 41, the hydraulic braking force FH is generated by the front wheel braking mechanism 31. When the brake operation BO is performed using the second brake operation unit 42, the hydraulic braking force FH is generated by the rear wheel braking mechanism 32. In addition, from time T22 onward, the total braking force FT also increases. Then, at time T23, following time T22, the execution unit 22 determines that the brake operation BO has been initiated. Therefore, at time T23, the execution unit 22 starts the hydraulic control operation and the regenerative braking force increase operation.

[0065] As described above, the hydraulic control operation is an operation that controls the hydraulic control unit 13 so that the wheel cylinder pressure is lower than the master cylinder pressure. By performing the hydraulic control operation, the hydraulic braking force FH can be reduced compared to when the hydraulic control operation is not performed. For example, in the hydraulic control operation, the execution unit 22 can lower the wheel cylinder pressure to the master cylinder pressure by reducing the opening degree of the suction valve 61 compared to when the hydraulic control operation is not performed. Alternatively, for example, in the hydraulic control operation, the execution unit 22 can lower the wheel cylinder pressure to the master cylinder pressure by operating the suction valve 61 to repeatedly switch between open and closed states, thereby shortening the time the suction valve 61 is open per unit time. The execution unit 22 may also lower the wheel cylinder pressure to the master cylinder pressure by controlling the operation of solenoid valves other than the suction valve 61.

[0066] Furthermore, when a brake operation BO is performed using the first brake operation unit 41 and a hydraulic braking force FH is generated by the front wheel braking mechanism 31, the execution unit 22 controls the hydraulic control unit 13 in the hydraulic control operation so that the wheel cylinder pressure of the front wheel braking mechanism 31 becomes lower than the master cylinder pressure of the front wheel braking mechanism 31. Also, when a brake operation BO is performed using the second brake operation unit 42 and a hydraulic braking force FH is generated by the rear wheel braking mechanism 32, the execution unit 22 controls the hydraulic control unit 13 in the hydraulic control operation so that the wheel cylinder pressure of the rear wheel braking mechanism 32 becomes lower than the master cylinder pressure of the rear wheel braking mechanism 32.

[0067] Furthermore, as described above, the regenerative braking force increase operation is an operation that increases the regenerative braking force FR. Specifically, in the regenerative braking force increase operation, the execution unit 22 increases the regenerative braking force FR relative to the value before the start of the regenerative braking force increase operation. As described above, the execution unit 22 can adjust the regenerative braking force FR by, for example, controlling the operation of the inverter. Therefore, the execution unit 22 increases the regenerative braking force FR by, for example, controlling the operation of the inverter in the regenerative braking force increase operation.

[0068] Here, if the regenerative braking force FR is simply increased by the regenerative braking force increase operation, the power obtained by regenerative power generation can be increased, but there is a risk that the saddle-type vehicle 1 will be braked too strongly, causing discomfort to the rider. Therefore, the execution unit 22 performs hydraulic control operation and regenerative braking force increase operation so that the total braking force FT, which is the sum of the hydraulic braking force FH and the regenerative braking force FR, becomes the required braking force determined according to the brake operation BO. In this way, the power obtained by regenerative power generation can be increased while appropriately suppressing the possibility of causing discomfort to the rider.

[0069] The required braking force is the braking force requested by the rider and is determined, for example, based on the amount of operation of brake operation BO. As described above, in cases where the hydraulic control operation and the regenerative braking force increase operation are not performed (for example, the example in Figure 4 above), the total braking force FT changes according to the amount of operation of brake operation BO. For example, the total braking force FT in this example corresponds to the required braking force. Therefore, the execution unit 22 can determine the required braking force based, for example, the amount of operation of brake operation BO.

[0070] As described above, the execution unit 22 performs hydraulic control operations and regenerative braking force increase operations so that the total braking force FT becomes the required braking force. In other words, the execution unit 22 performs hydraulic control operations and regenerative braking force increase operations so that the amount of increase in regenerative braking force FR due to the regenerative braking force increase operation matches the amount of decrease in hydraulic braking force FH due to the hydraulic control operation. In the example in Figure 6, from time T23 onward, both hydraulic braking force FH and regenerative braking force FR increase in accordance with the increase in the required braking force due to the increase in the amount of brake operation BO. At this time, the ratio of hydraulic braking force FH and regenerative braking force FR in the total braking force FT is, for example, constant. In the example in Figure 6, from time T23 onward, as a result of the hydraulic control operation being performed, the rate of increase of hydraulic braking force FH is lower than the rate of increase between time T22 and time T23.

[0071] From time point T23 onward, the amount of brake operation BO gradually increases with the passage of time. The regenerative braking force FR also gradually increases in accordance with the increase in the amount of brake operation BO. Thus, in the regenerative braking force increase operation, the execution unit 22 increases the regenerative braking force FR in accordance with the increase in the amount of brake operation BO. However, if the rate of increase of the regenerative braking force FR in the regenerative braking force increase operation is excessively high, the feel of the brake control unit may become too stiff. Therefore, the rate of increase of the regenerative braking force FR in the regenerative braking force increase operation can be preset to a predetermined value, for example, a value that prevents the feel of the brake control unit from becoming too stiff. As mentioned above, the master cylinder pressure can be an indicator of the amount of brake operation BO. Therefore, the execution unit 22 can acquire the amount of brake operation BO based, for example, the output information of the master cylinder pressure sensor 83.

[0072] At time point T24, following time point T23, the regenerative braking force FR reaches its upper limit. In this way, the execution unit 22 increases the regenerative braking force FR to its upper limit during the regenerative braking force increase operation. For example, the control device 20 can obtain information indicating the upper limit of the regenerative braking force FR from a control device that directly controls the electric motor 11 (specifically, another control device other than the control device 20). The upper limit of the regenerative braking force FR is determined according to, for example, the speed V, the state information of the battery 12 (for example, information on the remaining capacity or temperature of the battery 12), etc.

[0073] From time T24 onward, the execution unit 22 performs a regenerative braking force maintenance operation to maintain the regenerative braking force FR at its upper limit. As a result, from time T24 onward, the regenerative braking force FR is maintained at its upper limit. Furthermore, from time T24 onward, the execution unit 22 performs a hydraulic pressure control operation so that the total braking force FT becomes the required braking force while the regenerative braking force FR is maintained at a constant level. Therefore, from time T24 onward, the rate of increase of the hydraulic braking force FH is higher than the rate of increase between time T23 and time T24.

[0074] At time point T25, following time point T24, the increase in the amount of brake operation BO stops, and consequently, the increase in the hydraulic braking force FH also stops. Therefore, from time point T25 onward, the total braking force FT is maintained at a constant level.

[0075] As described above, the upper limit of the regenerative braking force FR decreases as the speed V decreases to a certain extent. In the example in Figure 6, the upper limit of the regenerative braking force FR begins to decrease at time T26, after time T25. Therefore, from time T26 onward, the regenerative braking force FR decreases in accordance with the decrease in the upper limit. Here, the execution unit 22 performs a hydraulic pressure control operation while the regenerative braking force maintenance operation is being performed so that the total braking force FT becomes the required braking force. Therefore, from time T26 onward, the hydraulic braking force FH increases to compensate for the decrease in the regenerative braking force FR. Thus, from time T26 onward, the total braking force FT is maintained at a constant level.

[0076] Furthermore, at time T27, following time T26, the wheel cylinder pressure equals the master cylinder pressure, making it impossible to increase the hydraulic braking force FH any further. Therefore, from time T27 onward, the total braking force FT decreases to some extent. Then, at time T28, following time T27, the saddle-type vehicle 1 comes to a stop.

[0077] In the example shown in Figure 6, the hydraulic braking force FH is continuously generated between time points T23 and T28, during which the hydraulic control operation is performed. In other words, a situation where only the regenerative braking force FR is generated and the hydraulic braking force FH is not generated does not occur. Thus, the execution unit 22 performs the hydraulic control operation in such a way that the hydraulic braking force FH is continuously generated. This prevents a situation from occurring where no braking force is generated at all for the saddle-type vehicle 1 in the event that regenerative braking becomes impossible due to a failure of the electric motor 11 or the like. Therefore, it is possible to suppress the sudden acceleration of the saddle-type vehicle 1, thereby improving safety.

[0078] The above describes examples of processing performed by the control device 20 with reference to Figures 5 and 6. However, the control device 20 may perform processing other than that described above.

[0079] For example, the above describes an example in which the rate of increase of the regenerative braking force FR in the regenerative braking force increase operation is preset. However, the execution unit 22 may change the rate of increase of the regenerative braking force FR in the regenerative braking force increase operation depending on the situation. For example, the execution unit 22 may change the rate of increase of the regenerative braking force FR in the regenerative braking force increase operation based on the driving mode of the saddle-type vehicle 1. Examples of driving modes include a sport mode in which the behavior of the saddle-type vehicle 1 is controlled to be more sporty than its general behavior. For example, the rider can change the driving mode by operating the input device 14. Here, the upper limit of the rate of increase of the regenerative braking force FR may differ depending on the driving mode. Therefore, the execution unit 22 may, for example, set the rate of increase of the regenerative braking force FR in the regenerative braking force increase operation higher the higher the upper limit according to the driving mode.

[0080] Furthermore, for example, the execution unit 22 may prohibit regenerative braking operation based on the status information of the battery 12. The status information of the battery 12 includes various information about the state of the battery 12, and may include, for example, information on the remaining capacity or temperature of the battery 12. For example, if the remaining capacity of the battery 12 is greater than a predetermined value (for example, if the battery 12 is almost fully charged), the execution unit 22 may prohibit regenerative braking operation because charging the battery 12 becomes difficult. Also, for example, if the temperature of the battery 12 is higher than a predetermined value (for example, if the temperature is so high that it is suspected that there is an abnormality in the battery 12), the execution unit 22 may prohibit regenerative braking operation because charging the battery 12 becomes difficult. In addition, when charging the battery 12 becomes difficult, the execution unit 22 may control the flow of power so that the power obtained by regenerative power generation is not sent to the battery 12 but to a location other than the battery 12.

[0081] Furthermore, the execution unit 22 may perform additional control not mentioned above. For example, when a brake operation BO is performed using the first brake operation unit 41 and a hydraulic braking force FH is generated by the front wheel braking mechanism 31, the execution unit 22 may additionally perform control to automatically generate a hydraulic braking force FH using the rear wheel braking mechanism 32.

[0082] <Effects of the control device> The effects of the control device 20 according to an embodiment of the present invention will be described.

[0083] The control device 20 controls the behavior of a saddle-type vehicle 1, which includes a master cylinder 51 connected to a brake operation unit (in the above example, a first brake operation unit 41 or a second brake operation unit 42), a wheel cylinder 54, and a hydraulic control unit 13 connected to each of these units that controls the wheel cylinder pressure, which is the pressure of the brake fluid in the wheel cylinder 54, and an electric motor 11 as a drive source. The control device 20 also includes an execution unit 22 that performs a regenerative braking operation to brake the saddle-type vehicle 1 using regenerative braking with the electric motor 11. The execution unit 22 performs a hydraulic control operation to control the hydraulic control unit 13 so that the wheel cylinder pressure is lower than the master cylinder pressure, which is the pressure of the brake fluid in the master cylinder 51, when the rider of the saddle-type vehicle 1 is performing a brake operation BO using the brake operation unit, and at the same time performs a regenerative braking force increasing operation to increase the regenerative braking force FR, which is the braking force acting on the saddle-type vehicle 1 by the regenerative braking operation. As a result, when braking operation BO is performed, the proportion of regenerative braking force FR in the total braking force (total braking force FT in the above example) acting on the saddle-type vehicle 1 can be increased, and more electricity can be obtained through regenerative power generation. Therefore, the amount of electricity obtained through regenerative power generation can be increased.

[0084] Preferably, in the control device 20, the execution unit 22 performs hydraulic control operation and regenerative braking force increasing operation so that the sum of the hydraulic braking force FH, which is the braking force acting on the saddle-type vehicle 1 by the wheel cylinder pressure, and the regenerative braking force FR (total braking force FT in the above example) becomes the required braking force determined according to the brake operation BO. This suppresses excessive braking of the saddle-type vehicle 1, thereby appropriately increasing the power obtained by regenerative power generation while suppressing any discomfort to the rider.

[0085] The execution unit 22 may also perform hydraulic control operations and regenerative braking force increasing operations so that the total braking force FT, which is the sum of the hydraulic braking force FH and the regenerative braking force FR, becomes to some extent larger or smaller than the required braking force.

[0086] Preferably, in the control device 20, the execution unit 22 performs hydraulic control operations so that a hydraulic braking force FH, which is a braking force acting on the saddle-type vehicle 1 due to the wheel cylinder pressure, continues to be generated. This prevents a situation from occurring where no braking force is generated on the saddle-type vehicle 1 if regenerative braking becomes impossible due to a failure of the electric motor 11 or the like. Therefore, it is possible to suppress the sudden acceleration of the saddle-type vehicle 1, thereby improving safety.

[0087] Furthermore, the execution unit 22 may perform hydraulic control operations such that a situation occurs at least once in which no hydraulic braking force FH is generated (for example, the hydraulic braking force FH may temporarily become 0 during the execution of hydraulic control operations).

[0088] Preferably, in the control device 20, the execution unit 22 increases the regenerative braking force FR to an upper limit during the regenerative braking force increase operation. As a result, more power can be obtained through regenerative power generation when the brake operation BO is being performed. Therefore, the power obtained through regenerative power generation can be effectively increased.

[0089] Furthermore, the execution unit 22 may control the regenerative braking force FR to remain below the upper limit during the regenerative braking force increase operation, rather than increasing it to the upper limit.

[0090] Preferably, in the control device 20, the execution unit 22 increases the regenerative braking force FR in accordance with the increase in the amount of brake operation BO during the regenerative braking force increase operation. This prevents the brake operation from becoming too stiff due to a sudden increase in the ratio of regenerative braking force FR to the total braking force FT when brake operation BO is being performed.

[0091] Furthermore, the execution unit 22 may discretely change the regenerative braking force FR at least once during the regenerative braking force increase operation (i.e., to distant values) (for example, the regenerative braking force FR may change temporarily in a step-like manner during the execution of the regenerative braking force increase operation).

[0092] Preferably, in the control device 20, the execution unit 22 changes the rate of increase of the regenerative braking force FR in the regenerative braking force increase operation based on the driving mode of the saddle-type vehicle 1. This appropriately realizes that a large amount of power can be obtained by regenerative power generation according to the driving mode. Thus, it is appropriately realized that the amount of power obtained by regenerative power generation can be increased according to the driving mode.

[0093] Preferably, in the control device 20, the execution unit 22 determines whether or not brake operation BO has started, and if it determines that brake operation BO has started, it starts the hydraulic pressure control operation and the regenerative braking force increase operation. This allows the hydraulic pressure control operation and the regenerative braking force increase operation to start after appropriately recognizing that brake operation BO has started. Therefore, for example, it is possible to suppress the saddle-type vehicle 1 from being braked too strongly due to the regenerative braking force increase operation being performed when brake operation BO is not being performed.

[0094] Preferably, in the control device 20, the execution unit 22 determines whether or not brake operation BO has been initiated based on the master cylinder pressure. This allows for an appropriate determination of whether or not brake operation BO has been initiated.

[0095] Preferably, in the control device 20, the execution unit 22 prohibits regenerative braking operation based on the state information of the battery 12 that stores the power supplied to the electric motor 11. This allows the system to focus on the state of the battery 12 and prohibit regenerative braking operation in situations where charging the battery 12 becomes difficult.

[0096] Preferably, the hydraulic control unit 13 controls the wheel cylinder pressure of at least the front wheels 2 of the saddle-type vehicle 1. Generally, when braking the saddle-type vehicle 1, braking the front wheels 2 makes it easier to brake the saddle-type vehicle 1 effectively compared to braking the rear wheels 3. Furthermore, with the hydraulic control unit 13 described above, it is possible to increase the power obtained by regenerative power generation when braking the saddle-type vehicle 1 using the brake operation BO performed with the first brake operation unit 41, which is commonly performed when braking the saddle-type vehicle 1.

[0097] The present invention is not limited to the descriptions of embodiments. For example, only a portion of the embodiments may be implemented. [Explanation of symbols]

[0098] 1 Saddle-type vehicle, 2 Front wheel, 2a Rotor, 3 Rear wheel, 3a Rotor, 10 Brake system, 11 Electric motor, 12 Battery, 13 Hydraulic control unit, 13a Base, 14 Input device, 15 Front wheel speed sensor, 16 Rear wheel speed sensor, 20 Control device, 21 Acquisition unit, 22 Execution unit, 31 Front wheel braking mechanism, 32 Rear wheel braking mechanism, 41 First brake operation unit, 42 Second brake operation unit, 51 Master cylinder, 52 Reservoir, 53 Brake caliper, 54 Wheel cylinder, 55 Main flow path, 56 Sub-flow path, 61 Loading valve, 62 Release valve, 63 Accumulator, 64 Pump, 71 Motor, 81 First brake operation unit sensor, 82 Second brake operation unit sensor, 83 Master cylinder pressure sensor, AO Accelerator operation, BO Brake operation, F Various braking forces, FH Hydraulic braking force, FR regenerative braking force, FT total braking force, V speed.

Claims

1. A control device (20) for controlling the behavior of a saddle-type vehicle (1) comprising a master cylinder (51) connected to brake operating units (41, 42) and a wheel cylinder (54), respectively, and a hydraulic control unit (13) connected to the wheel cylinder (54) for controlling the wheel cylinder pressure, which is the pressure of the brake fluid in the wheel cylinder (54), and an electric motor (11) as a drive source, The system includes an execution unit (22) that performs a regenerative braking operation to brake the saddle-type vehicle (1) using the regenerative brake of the electric motor (11), The execution unit (22), while in a situation where the rider of the saddle-type vehicle (1) is performing a brake operation using the brake operation units (41, 42), performs a hydraulic pressure control operation to control the hydraulic pressure control unit (13) so that the wheel cylinder pressure becomes lower than the master cylinder pressure, which is the brake fluid pressure of the master cylinder (51), and also performs a regenerative braking force increasing operation to increase the regenerative braking force (FR), which is the braking force acting on the saddle-type vehicle (1) by the regenerative braking operation. Control device.

2. The execution unit (22) performs the hydraulic control operation and the regenerative braking force increase operation so that the sum (FT) of the hydraulic braking force (FH), which is the braking force acting on the saddle-type vehicle (1) by the wheel cylinder pressure, and the regenerative braking force (FR) becomes the required braking force determined according to the brake operation. The control device according to claim 1.

3. The execution unit (22) performs the hydraulic control operation so that the hydraulic braking force (FH), which is the braking force acting on the saddle-type vehicle (1) by the wheel cylinder pressure, continues to be generated. The control device according to claim 1.

4. The execution unit (22) increases the regenerative braking force (FR) to the upper limit in the regenerative braking force increase operation. The control device according to claim 1.

5. The execution unit (22) increases the regenerative braking force (FR) in the regenerative braking force increase operation in accordance with the increase in the amount of the brake operation. The control device according to claim 1.

6. The execution unit (22) changes the rate of increase of the regenerative braking force (FR) in the regenerative braking force increase operation based on the driving mode of the saddle-type vehicle (1). The control device according to claim 5.

7. The execution unit (22) determines whether or not the brake operation has been started, and if it determines that the brake operation has been started, it starts the hydraulic pressure control operation and the regenerative braking force increase operation. The control device according to claim 1.

8. The execution unit (22) determines whether or not the brake operation has been initiated based on the master cylinder pressure. The control device according to claim 7.

9. The execution unit (22) prohibits the regenerative braking operation based on the state information of the battery (12) that stores the power supplied to the electric motor (11). The control device according to claim 1.

10. The hydraulic control unit (13) controls the wheel cylinder pressure of at least the front wheel (2) of the saddle-type vehicle (1). The control device according to any one of claims 1 to 9.

11. A control method for controlling the behavior of a saddle-type vehicle (1) comprising a master cylinder (51) connected to brake operating units (41, 42), a wheel cylinder (54), a hydraulic control unit (13) connected to the wheel cylinder (54) and controlling the wheel cylinder pressure, which is the pressure of the brake fluid in the wheel cylinder (54), and an electric motor (11) as a drive source, wherein The execution unit (22) of the control device (20) performs a regenerative braking operation to brake the saddle-type vehicle (1) using the regenerative brake with the electric motor (11). The execution unit (22), while in a situation where the rider of the saddle-type vehicle (1) is performing a brake operation using the brake operation units (41, 42), performs a hydraulic pressure control operation to control the hydraulic pressure control unit (13) so that the wheel cylinder pressure becomes lower than the master cylinder pressure, which is the brake fluid pressure of the master cylinder (51), and also performs a regenerative braking force increasing operation to increase the regenerative braking force (FR), which is the braking force acting on the saddle-type vehicle (1) by the regenerative braking operation. Control method.

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