Vehicle and braking control device

Abstract

To provide a vehicle capable of suppressing deterioration of braking performance when the temperature of a braking device is low.SOLUTION: A vehicle according to an embodiment of the present disclosure includes a brake device including a brake disc attached to a wheel of the vehicle and a brake pad that can come into contact with the brake disc, the brake device being capable of braking the vehicle by bringing the brake pad into contact with the brake disc, and a control device capable of acquiring a temperature of the brake device and operating the brake device during acceleration of the vehicle when the temperature of the brake device is lower than a threshold temperature.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a vehicle capable of controlling a braking device, and a braking control device for use in such a vehicle. [Background technology]

[0002] A vehicle is generally provided with brake pads and brake discs, and the frictional force generated when they come into contact with each other brakes the vehicle. For example, Patent Document 1 discloses a technique for increasing the temperature of the braking device by intermittently pressing the brake pads against the brake disc when the temperature of the braking device is low and the frictional force between the brake pads and the brake disc is unstable. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-6970 Summary of the Invention [Problem to be solved by the invention]

[0004] Thus, in a vehicle, when the temperature of the braking device is low, it is desirable to suppress the deterioration of braking performance, and it is expected that braking performance will be ensured.

[0005] It is desirable to provide a vehicle and a brake control device that can suppress deterioration in braking performance when the temperature of the brake device is low. [Means for solving the problem]

[0006] A vehicle according to an embodiment of the present disclosure includes a braking device and a control device. The braking device has brake discs attached to wheels of the vehicle and brake pads that can contact the brake discs, and the brake pads can brake the vehicle when the brake pads contact the brake discs. The control device is capable of acquiring the temperature of the braking device and is capable of operating the braking device when the temperature of the braking device is lower than a threshold temperature.

[0007] A braking control device according to an embodiment of the present disclosure includes a control device that can acquire the temperature of a braking device that can brake a vehicle by contacting a brake pad with a brake disc, and that can operate the braking device when the vehicle is accelerating if the temperature of the braking device is lower than a predetermined temperature. [Effects of the Invention]

[0008] According to the vehicle and braking control device according to one embodiment of the present disclosure, it is possible to suppress a decrease in braking performance when the temperature of the braking device is low. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram illustrating an example configuration of a vehicle according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a flowchart showing an example of an operation for warming up the braking device in the vehicle shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0011] <Embodiment> [Configuration example] 1 shows an example of the configuration of a vehicle (vehicle 1) according to one embodiment. In this example, vehicle 1 is an electrically powered vehicle such as an electric car. Vehicle 1 includes an accelerator pedal 11, a battery 12, an inverter 13, a motor 14, a driving force transmission mechanism 15, four wheels 16, a brake pedal 21, a brake booster 22, a VDC (Vehicle Dynamics Control) unit 23, four braking devices 24, and a control device 30.

[0012] The accelerator pedal 11 is configured to accept an acceleration operation by the driver. The driver performs an acceleration operation by depressing the accelerator pedal 11. The accelerator pedal 11 is configured to accept this acceleration operation.

[0013] The battery 12 is configured to store electric power used when the vehicle 1, which is an electric vehicle, travels.

[0014] The inverter 13 is configured to convert DC power supplied from the battery 12 to AC power based on an acceleration command supplied from the control device 30, and to use the converted AC power to drive the motor 14. The inverter 13 is also configured to supply regenerative power supplied from the motor 14 to the battery 12.

[0015] The motor 14 is configured to generate driving force based on the AC voltage supplied from the inverter 13. The motor 14 is also configured to generate regenerative power, for example, when the vehicle 1 decelerates.

[0016] The driving force transmission mechanism 15 is configured to transmit the driving force generated by the motor 14 to the four wheels 16.

[0017] Each of the four wheels 16 is configured to rotate about an axle based on driving force supplied from the motor 14 via the driving force transmission mechanism 15, thereby causing the vehicle 1 to travel. The four wheels 16 include two wheels 16 on the left and right at the front of the vehicle 1 and two wheels 16 on the left and right at the rear of the vehicle 1.

[0018] The brake pedal 21 is configured to receive a braking operation by the driver. The driver performs a braking operation by stepping on the brake pedal 21. The brake pedal 21 is configured to receive this braking operation.

[0019] The brake booster 22 is configured to change the pressure of the brake fluid (oil in this example) based on a braking command supplied from the control device 30.

[0020] The VDC unit 23 is configured to adjust the pressure of the brake fluid supplied to each of the four braking devices 24 .

[0021] The four braking devices 24 are provided corresponding to the four wheels 16, respectively, and are configured to brake the vehicle 1. Each of the four braking devices 24 has a brake disc 25 and brake pads 26. The brake disc 25 is attached to the corresponding wheel 16 and configured to rotate together with the wheel 16. The brake pads 26 are configured to sandwich the brake disc 25 from both sides. The braking devices 24 press the brake pads 26 against the brake disc 25 in accordance with the pressure of the brake fluid, thereby bringing the brake pads 26 and the brake disc 25 into contact with each other. As a result, frictional force is generated between the brake disc 25 and the brake pads 26 in the braking devices 24, and this frictional force is capable of braking the vehicle 1.

[0022] The control device 30 is, for example, an ECU (Electronic Control Unit) and includes one or more processors and one or more memories. The control device 30 has a motor control unit 31, a speed estimating unit 32, a braking control unit 33, and a temperature estimating unit 34.

[0023] The motor control unit 31 is configured to issue an acceleration command to the inverter 13 based on the amount of depression of the accelerator pedal 11 by the driver. The motor control unit 31 also supplies the braking control unit 33 with information as to whether the vehicle 1 is accelerating.

[0024] The speed estimation unit 32 is configured to estimate the speed of the vehicle 1. Specifically, the speed estimation unit 32 estimates the speed of the vehicle 1 based on information such as the rotation speed of the motor 14. The speed estimation unit 32 also estimates the acceleration of the vehicle 1 based on the change in the speed of the vehicle 1 over time.

[0025] The braking control unit 33 is configured to issue a braking command to the brake booster 22 based on the amount of depression of the brake pedal 21 by the driver. Furthermore, when the temperature estimated by the temperature estimating unit 34 is lower than a predetermined threshold temperature, the braking control unit 33 issues a braking command to the brake booster 22 so as to operate the braking device 24 to such an extent that the acceleration of the vehicle 1 is not hindered when the vehicle 1 accelerates. As a result, in the vehicle 1, for example in cold regions, when the temperature of the braking device 24 is low, the braking device 24 is warmed up early after the vehicle starts traveling, thereby preventing a decrease in braking performance.

[0026] The temperature estimation unit 34 is configured to estimate the temperature of the braking device 24. Specifically, the temperature estimation unit 34 is configured to estimate the temperature of the braking device 24 based on, for example, a braking amount indicating the strength of the braking force in the braking device 24 and a braking time indicating the time for which the braking force is applied.

[0027] Here, the braking device 24 corresponds to a specific example of a "braking device" in an embodiment of the present disclosure. The brake disc 25 corresponds to a specific example of a "brake disc" in an embodiment of the present disclosure. The brake pad 26 corresponds to a specific example of a "brake pad" in an embodiment of the present disclosure. The control device 30 corresponds to a specific example of a "control device" in an embodiment of the present disclosure.

[0028] [Actions and Actions] Next, the operation and function of the vehicle 1 of this embodiment will be described.

[0029] (Overview of overall operation) First, an overview of the overall operation of vehicle 1 will be described with reference to FIG. 1. Accelerator pedal 11 accepts acceleration operation by the driver. Battery 12 stores power used when vehicle 1, which is an electric vehicle, travels. Inverter 13 converts DC power supplied from battery 12 to AC power based on an acceleration command supplied from control device 30, and drives motor 14 using the converted AC power. In addition, inverter 13 supplies regenerative power supplied from motor 14 to battery 12. Motor 14 generates driving force based on the AC voltage supplied from inverter 13. In addition, motor 14 generates regenerative power, for example, when vehicle 1 decelerates. Driving force transmission mechanism 15 transmits the driving force generated by motor 14 to four wheels 16. Each of four wheels 16 rotates about its axle based on the driving force supplied from motor 14 via driving force transmission mechanism 15, thereby propelling vehicle 1.

[0030] The brake pedal 21 receives a braking operation by the driver. The brake booster 22 changes the pressure of the brake fluid based on a braking command supplied from the control device 30. The VDC unit 23 adjusts the pressure of the brake fluid supplied to each of the four braking devices 24. The four braking devices 24 brake the vehicle 1.

[0031] The motor control unit 31 of the control device 30 issues an acceleration command to the inverter 13 based on the amount of depression of the accelerator pedal 11 by the driver. The speed estimation unit 32 estimates the speed and acceleration of the vehicle 1. The braking control unit 33 issues a braking command to the brake booster 22 based on the amount of depression of the brake pedal 21 by the driver. Furthermore, if the temperature estimated by the temperature estimation unit 34 is lower than a predetermined temperature, the braking control unit 33 issues a braking command to the brake booster 22 when accelerating the vehicle 1 so as to operate the braking device 24 to an extent that the effect on the acceleration of the vehicle 1 is minimized. The temperature estimation unit 34 estimates the temperature of the braking device 24.

[0032] (Detailed operation) In the vehicle 1, when the temperature of the braking device 24 is low, the braking device 24 is warmed up by operating the braking device 24 when the vehicle 1 is accelerating. This operation will be described in detail below.

[0033] FIG. 2 shows an example of an operation for warming up the braking device 24 in the vehicle 1. In FIG.

[0034] First, the temperature estimation unit 34 of the control device 30 estimates the temperature of the braking device 24 (step S101). Specifically, the temperature estimation unit 34 estimates the temperature of the braking device 24 based on the braking amount, which indicates the strength of the braking force in the braking device 24, and the braking time, which is the time for which the braking force is applied.

[0035] Next, the braking control unit 33 of the control device 30 checks whether the temperature of the braking device 24 is lower than the threshold temperature (step S102). If the temperature of the braking device 24 is equal to or higher than the threshold temperature ("N" in step S102), this flow ends.

[0036] In step S102, if the temperature of the braking device 24 is lower than the threshold temperature ("Y" in step S102), the braking control unit 33 checks whether the vehicle 1 is accelerating or not (step S103) based on information from the motor control unit 31. If the vehicle 1 is not accelerating, this flow ends.

[0037] If the vehicle 1 is accelerating ("Y" in step S103), the braking control unit 33 sets the braking amount of the braking device 24 based on the temperature of the braking device 24, the speed and acceleration of the vehicle 1, so that the acceleration of the vehicle 1 is not hindered (step S104). Specifically, the speed estimating unit 32 estimates the speed of the vehicle 1, and also estimates the acceleration of the vehicle 1 based on the change in the speed of the vehicle 1 over time. Then, the braking control unit 33 sets the braking amount so that the acceleration of the vehicle 1 is not hindered while bringing the brake pads 26 into contact with the brake discs 25, based on the temperature of the braking device 24 estimated in step S101, and the speed and acceleration of the vehicle 1.

[0038] Then, the braking control unit 33 controls the operation of the braking device 24 based on the braking amount set in step S104 (step S105). As a result, the braking device 24 brings the brake pads 26 into contact with the brake discs 25 to an extent that does not impede the acceleration of the vehicle 1. As a result, in the braking device 24, frictional force is generated between the brake discs 25 and the brake pads 26, and this frictional force warms up the braking device 24.

[0039] This is the end of the flow. The vehicle 1 repeats this flow.

[0040] In this way, the vehicle 1 is provided with a braking device 24 that has brake discs 25 attached to the wheels 16 of the vehicle 1 and brake pads 26 that can come into contact with the brake discs 25 and that can brake the vehicle 1 when the brake pads 26 come into contact with the brake discs 25, and a control device 30 that can acquire the temperature of the braking device 24 and, when the temperature of the braking device 24 is lower than a threshold temperature, can operate the braking device 24 when the vehicle 1 is accelerating. As a result, the vehicle 1 can suppress a decrease in braking performance when, for example, the temperature of the braking device 24 is low.

[0041] That is, for example, when the vehicle 1 is in a cold region, the temperature of the braking device 24 may be very low. In such a case, even if the brake pads 26 are brought into contact with the brake disc 25, the desired frictional force may not be obtained, and sufficient braking performance may not be exhibited. In the vehicle 1, when the temperature of the braking device 24 is lower than a predetermined threshold temperature, the brake pads 26 are brought into contact with the brake disc 25 during acceleration of the vehicle 1. That is, in the vehicle 1, for example, when the vehicle 1 starts moving and is accelerating, the brake pads 26 are brought into contact with the brake disc 25. As a result, in the braking device 24, frictional force is generated between the brake disc 25 and the brake pads 26, and this frictional force can warm up the braking device 24. As a result, the vehicle 1 can suppress a decrease in braking performance.

[0042] In particular, in vehicle 1, since braking device 24 can be warmed up when vehicle 1 starts traveling and is accelerating, braking performance can be ensured, for example, at the first braking after starting traveling. That is, for example, if braking device 24 is warmed up when operating braking device 24 to decelerate vehicle 1, braking performance is unlikely to be exerted at the first braking after starting traveling. On the other hand, in vehicle 1 according to this embodiment, braking device 24 is warmed up when vehicle 1 is accelerating, so braking performance can be ensured at the first braking after starting traveling.

[0043] Furthermore, the vehicle 1 is an electric vehicle. In an electric vehicle, the vehicle 1 can be decelerated not only by operating the brake device 24 but also by regenerating energy using the motor 14. Therefore, in an electric vehicle, the brake device 24 is used infrequently, and therefore there is little opportunity to warm up the brake device 24. Since the present technology is applied to the vehicle 1, the brake device 24 can be effectively warmed up in an electric vehicle in which the brake device 24 is used infrequently, and deterioration of braking performance can be suppressed. Furthermore, when the brake device 24 is used infrequently, rust may occur on the brake disc 25, for example. In the vehicle 1, by bringing the brake pad 26 into contact with the brake disc 25, rust on this contact surface can be removed, thereby smoothing the contact surface, thereby ensuring braking performance.

[0044] Furthermore, in vehicle 1, since braking device 24 is warmed up when vehicle 1, which is an electric vehicle, is accelerating, it is possible to reduce the impact on the electric power consumption of vehicle 1 and the distance that vehicle 1 can travel. That is, for example, if braking device 24 is warmed up when braking device 24 is operated to decelerate vehicle 1, the opportunity to regenerate energy by motor 14 to brake vehicle 1 is reduced, and the amount of energy that can be regenerated is reduced. On the other hand, in vehicle 1, braking device 24 is warmed up when vehicle 1 is accelerating, so the amount of energy that can be regenerated is not reduced in this way, and it is possible to reduce the impact on the electric power consumption of vehicle 1 and the distance that vehicle 1 can travel.

[0045] Furthermore, in the vehicle 1, the control device 30 is capable of calculating the braking amount of the brake device 24 based on one or more of the temperature of the brake device 24, the traveling speed of the vehicle 1, and the acceleration of the vehicle 1, and is capable of operating the brake device 24 based on this braking amount when the temperature of the brake device 24 is lower than a threshold temperature. This allows the brake pads 26 to come into contact with the brake discs 25 to an extent that does not impede acceleration. In other words, the braking amount that does not impede acceleration may vary depending on, for example, the temperature of the brake device 24, the traveling speed and acceleration of the vehicle 1, etc. Therefore, in the vehicle 1, the control device 30 calculates the braking amount of the brake device 24 based on the temperature of the brake device 24, the traveling speed of the vehicle 1, and the acceleration of the vehicle 1. This allows the vehicle 1 to operate the brake device 24 based on, for example, an appropriate braking amount that does not impede acceleration.

[0046] [effect] As described above, this embodiment includes a braking device that has brake discs attached to vehicle wheels and brake pads that can come into contact with the brake discs and that can brake the vehicle 1 when the brake pads come into contact with the brake discs, and a control device that can acquire the temperature of the braking device and operate the braking device when the vehicle accelerates if the temperature of the braking device is lower than a threshold temperature. This makes it possible to prevent a decrease in braking performance when the temperature of the braking device is low. In particular, it is possible to ensure braking performance during the first braking after starting to drive.

[0047] In this embodiment, vehicle 1 is an electric vehicle, and therefore, in an electric vehicle in which the braking device is used infrequently, the braking device can be effectively warmed up, and a decrease in braking performance can be suppressed. Also, in an electric vehicle in which the braking device is used infrequently, the contact surface can be smoothed, and braking performance can be ensured. Furthermore, the impact on the vehicle's electricity consumption and the distance the vehicle can travel can be suppressed.

[0048] In this embodiment, the control device is capable of calculating the braking amount of the braking device based on one or more of the temperature of the braking device, the traveling speed of the vehicle 1, and the acceleration of the vehicle 1, and when the temperature of the braking device is lower than a threshold temperature, it is possible to operate the braking device based on this braking amount when the vehicle accelerates.Therefore, for example, the braking device can be operated based on an appropriate braking amount that does not hinder acceleration.

[0049] Although the present technology has been described above by giving embodiments, the present technology is not limited to these embodiments and can be modified in various ways.

[0050] For example, in the above embodiment, the present technology is applied to an electric vehicle, but is not limited to this. Instead, the present technology may be applied to a vehicle that uses an engine as a driving force source.

[0051] For example, in the above embodiment, the temperature estimation unit 34 estimates the temperature of the braking device 24 to obtain the temperature of the braking device 24, but this is not limited to this. Instead, for example, a temperature sensor may be provided in the braking device 24, and the control device 30 may obtain the temperature detected by the temperature sensor.

[0052] For example, in the above embodiment, as shown in step S104 of Fig. 2, the braking control unit 33 sets the braking amount of the braking device 24 based on the temperature of the braking device 24, and the speed and acceleration of the vehicle 1, but this is not limited to this. Alternatively, the braking control unit 33 may set the braking amount of the braking device 24 based on one or more of the temperature of the braking device 24, the speed of the vehicle 1, and the acceleration of the vehicle 1.

[0053] The effects described in this specification are merely examples and are not limiting, and other effects may also be present.

[0054] Furthermore, the present disclosure may take the following aspects.

[0055] (1) a braking device including a brake disc attached to a wheel of a vehicle and a brake pad capable of coming into contact with the brake disc, the brake pad coming into contact with the brake disc to brake the vehicle; a control device capable of acquiring the temperature of the braking device and operating the braking device when the temperature of the braking device is lower than a threshold temperature; A vehicle equipped with. (2) The control device The braking amount of the braking device can be calculated based on one or more of the temperature of the braking device, the traveling speed of the vehicle, and the acceleration of the vehicle; When the temperature of the braking device is lower than the threshold temperature, the braking device can be operated based on the braking amount during acceleration of the vehicle. The vehicle described in (1) above. (3) The vehicle is equipped with a control device that has a brake disc attached to a wheel of the vehicle and a brake pad that can come into contact with the brake disc, and that can acquire the temperature of a braking device that can brake the vehicle when the brake pad comes into contact with the brake disc, and that can operate the braking device when the vehicle is accelerating if the temperature of the braking device is lower than a predetermined temperature. Braking control device. [Explanation of symbols]

[0056] 1...vehicle, 11...accelerator pedal, 12...battery, 13...inverter, 14...motor, 15...driving force transmission mechanism, 16...wheel, 21...brake pedal, 22...brake booster, 23...VDC unit, 24...braking device, 25...brake disc, 26...brake pad, 30...control device, 31...motor control unit, 32...speed estimation unit, 33...braking control unit, 34...temperature estimation unit

Claims

1. a braking device including a brake disc attached to a wheel of a vehicle and a brake pad capable of coming into contact with the brake disc, the brake pad coming into contact with the brake disc to brake the vehicle; a control device capable of acquiring the temperature of the braking device and operating the braking device when the temperature of the braking device is lower than a threshold temperature; A vehicle equipped with.

2. The control device a braking amount of the braking device can be calculated based on one or more of a temperature of the braking device, a traveling speed of the vehicle, and an acceleration of the vehicle; When the temperature of the braking device is lower than the threshold temperature, the braking device can be operated based on the braking amount during acceleration of the vehicle. The vehicle of claim 1 .

3. The temperature of a braking device capable of braking a vehicle by contacting a brake pad with a brake disc can be acquired, and a control device can operate the braking device when the vehicle is accelerating if the temperature of the braking device is lower than a threshold temperature. Braking control device.

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