Brake control device

Abstract

This invention provides a braking control device. When the braking control device (10) is functioning normally, the first indicator (40) indicates the braking force applied to the first wheel (11) and the third wheel (13), respectively, and the second indicator (41) indicates the braking force applied to the second wheel (12) and the fourth wheel (14), respectively. If the first indicator (40) malfunctions and cannot indicate the braking force applied to the first wheel (11) and the third wheel (13), the second indicator (41) supplements the indication of the braking force applied to the first wheel (11), and the third indicator (60) supplements the indication of the braking force applied to the third wheel (13).

Description

Technical Field

[0001] This invention relates to a braking control device for controlling the braking force applied to the wheels of a vehicle. Background Technology

[0002] As a braking control device that controls the braking force applied to each wheel of a vehicle, the device described in Patent Document 1 is known. The braking control device of this document includes a first ECU and a second ECU as electronic control units (ECUs) that indicate the braking force applied to each wheel. Furthermore, in the braking control device of this document, when either ECU malfunctions, the other ECU supplements the processing of the malfunctioning ECU to continue the braking force control of each wheel.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2019-89505

[0004] In the aforementioned conventional braking control devices, when one ECU malfunctions, the processing load on the other ECU increases significantly. Therefore, both ECUs need to have a much higher processing capacity than required under normal conditions. Summary of the Invention

[0005] The braking control device for solving the aforementioned problem is a device for controlling the braking force applied to the wheels of a vehicle, including a first wheel, a second wheel, a third wheel, and a fourth wheel. This braking control device has a first main indicator, a second main indicator, and a backup indicator as indicators of the braking force applied to the wheels. In this braking control device, when both the first and second main indicators function normally, the first main indicator indicates the braking force applied to the first and third wheels, and the second main indicator indicates the braking force applied to the second and fourth wheels. Furthermore, in the event of an anomaly, the second main indicator supplements the indication of the braking force applied to the first wheel, and the backup indicator supplements the indication of the braking force applied to the third wheel; the anomaly refers to a situation where only the second main indicator functions normally.

[0006] Here, in the aforementioned braking control device, when the first main indicator malfunctions, we consider the case where its function is supplemented solely by the second main indicator. In this case, when the first main indicator malfunctions, the number of wheels indicated by the second main indicator increases from two to four, and correspondingly, the processing load of the second main indicator also increases. On the other hand, when the first main indicator malfunctions, we consider the case where its function is supplemented solely by the backup indicator. In this case, it is necessary for the backup indicator to have the same functionality as the first main indicator. However, it is difficult to provide a high-functionality backup indicator solely for the purpose of preventing the first main indicator from malfunctioning in terms of cost-effectiveness.

[0007] In this respect, in the aforementioned braking control device, when the first main indicator fails to function properly, the second main indicator and the backup indicator take over the supplementary function of indicating the braking force of the first and third wheels provided by the first main indicator. Therefore, the increased processing load of the second main indicator during abnormal situations is suppressed. Furthermore, the backup indicator requires fewer functions. Thus, a braking control device with high resistance to abnormalities can be easily implemented. Attached Figure Description

[0008] Figure 1 This is a schematic diagram illustrating the structure of one embodiment of the braking control device.

[0009] Figure 2 This is a diagram showing the normal operating mode of the braking control device.

[0010] Figure 3 This diagram illustrates the operation of the braking control device when the first indicator malfunctions.

[0011] Figure 4 This diagram illustrates the operation of the braking control device when the first and second indicator sections malfunction.

[0012] Figure 5 This is a diagram illustrating the operation mode of system 3 in a modified example of the braking control device when an abnormality occurs.

[0013] Figure 6 This is a diagram illustrating the operation of the first indicator in other variations of the braking control device when it malfunctions.

[0014] Figure 7 This is a diagram illustrating the operation of the first indicator in a different variation of the braking control device when it malfunctions. Detailed Implementation

[0015] The following is based on Figures 1-4 An embodiment that embodies the braking control device will be described.

[0016] (Structure of brake control device 10)

[0017] Reference Figure 1 The structure of the braking control device 10 in this embodiment will be described. The braking control device 10 in this embodiment controls the braking force applied to the four wheels of a vehicle: the first wheel 11, the second wheel 12, the third wheel 13, and the fourth wheel 14. In this embodiment, the left front wheel is designated as the first wheel 11, the right front wheel as the second wheel 12, the left rear wheel as the third wheel 13, and the right rear wheel as the fourth wheel 14. The braking force applied to each wheel is controlled by hydraulic adjustment of the wheel cylinders 15-18 of each wheel.

[0018] Additionally, the braking control device 10 includes a first braking unit 30 and a second braking unit 50. The first braking unit 30 includes hydraulic circuits for the wheel cylinders 15 and 16 of the first wheel 11 and the second wheel 12. The second braking unit 50 includes hydraulic circuits for the wheel cylinders 17 and 18 of the third wheel 13 and the fourth wheel 14.

[0019] (Structure of the first braking unit 30)

[0020] The first braking unit 30 includes a first wheel actuator 31 that generates hydraulic pressure on the wheel cylinder 15 of the first wheel 11 and a second wheel actuator 32 that generates hydraulic pressure on the wheel cylinder 16 of the second wheel 12. In this embodiment, the first wheel actuator 31 and the second wheel actuator 32 may also be electric cylinders that generate hydraulic pressure by moving the piston cylinder internally via an electric motor.

[0021] Furthermore, the first braking unit 30 includes a first solenoid valve 34. The first solenoid valve 34 is a normally open solenoid valve that is closed when energized and open when de-energized. The wheel cylinder 15 of the first wheel 11 and the wheel cylinder 16 of the second wheel 12 are connected via the first solenoid valve 34. When the first solenoid valve 34 is open, the wheel cylinders 15 and 16 of both the first wheel 11 and the second wheel 12 are connected to the first wheel actuator 31 and the second wheel actuator 32.

[0022] Furthermore, the first braking unit 30 includes hydraulic sensors 37-38, a first drive circuit 42, and a second drive circuit 43. Hydraulic sensor 37 detects the hydraulic pressure generated by the first wheel actuator 31. Hydraulic sensor 38 detects the hydraulic pressure generated by the second wheel actuator 32. The first drive circuit 42 is a circuit for the electrical control of the first wheel actuator 31, and the second drive circuit 43 is a circuit for the electrical control of the second wheel actuator 32.

[0023] Furthermore, the first braking unit 30 includes a first indicator 40 and a second indicator 41. The first indicator 40 is an electronic control unit that includes one or more processors that perform various processes for controlling the braking force of the vehicle and a memory for storing control programs and data. The second indicator 41 is an electronic control unit configured similarly to the first indicator 40. The first indicator 40 is controllably connected to a first drive circuit 42, and the second indicator 41 is controllably connected to a second drive circuit 43. Both the first indicator 40 and the second indicator 41 are controllably connected to a first solenoid valve 34.

[0024] Furthermore, the first indicator 40 and the second indicator 41 are connected to the in-vehicle network 19. Thus, the first braking unit 30 communicates with devices mounted in the vehicle other than the braking control device 10 via the in-vehicle network 19. The first indicator 40 and the second indicator 41 are also connected to the communication 90 within the braking control device. Furthermore, the first indicator 40 and the second indicator 41 are connected in a manner capable of receiving sensor signals from vehicle sensors 91 such as travel sensors and wheel speed sensors. Additionally, the first indicator 40 and the second indicator 41 are connected within the first braking unit 30 in a manner capable of communicating with each other.

[0025] (Structure of the second braking unit 50)

[0026] The hydraulic circuit of the second braking unit 50 has the same structure as that of the first braking unit 30. Specifically, the second braking unit 50 includes a third-wheel actuator 51 that generates hydraulic pressure on the wheel cylinder 17 of the third wheel 13, and a fourth-wheel actuator 52 that generates hydraulic pressure on the wheel cylinder 18 of the fourth wheel 14. Furthermore, the second braking unit 50 includes a second solenoid valve 54, which is a normally open solenoid valve. The wheel cylinder 17 of the third wheel 13 and the wheel cylinder 18 of the fourth wheel 14 are connected via the second solenoid valve 54.

[0027] In addition, the second braking unit 50 includes hydraulic sensors 57-58, a third drive circuit 62, and a fourth drive circuit 63. Hydraulic sensor 57 detects the hydraulic pressure generated by the third wheel actuator 51. Hydraulic sensor 58 detects the hydraulic pressure generated by the fourth wheel actuator 52. The third drive circuit 62 is a circuit for the electrical control of the third wheel actuator 51, and the fourth drive circuit 63 is a circuit for the electrical control of the fourth wheel actuator 52.

[0028] Furthermore, the second braking unit 50 includes two electronic control units: a third indicator 60 and a fourth indicator 61. The third indicator 60 is controllably connected to the third drive circuit 62, and the fourth indicator 61 is controllably connected to the fourth drive circuit 63. Additionally, a second solenoid valve 54 is controllably connected to both the third indicator 60 and the fourth indicator 61.

[0029] Furthermore, the third indicator 60 and the fourth indicator 61 are connected to the communication 90 within the brake control device. Moreover, the third indicator 60 and the fourth indicator 61 can communicate with the first indicator 40 and the second indicator 41 via the communication 90 within the brake control device. The third indicator 60 and the fourth indicator 61 are connected in a manner that allows them to receive sensor signals from vehicle sensors 91 such as travel sensors and wheel speed sensors.

[0030] (Operation of the brake control device 10 under normal conditions)

[0031] Next, refer to Figure 2 The operation of the brake control device 10 under normal conditions will be explained. Here, "normal conditions" refers to a state where both the first indicator 40 and the second indicator 41 are functioning normally. Furthermore, in the following description, the hydraulic pressure of the wheel cylinder 15 of the first wheel 11 will be referred to as first wheel hydraulic pressure P1, and the hydraulic pressure of the wheel cylinder 16 of the second wheel 12 will be referred to as second wheel hydraulic pressure P2. Additionally, the hydraulic pressure of the wheel cylinder 17 of the third wheel 13 will be referred to as third wheel hydraulic pressure P3, and the hydraulic pressure of the wheel cylinder 18 of the fourth wheel 14 will be referred to as fourth wheel hydraulic pressure P4.

[0032] In addition, Figures 2-7 In the diagram, solid lines represent components of the braking control device 10 that are functioning normally, while dashed lines represent components that are not functioning normally. Additionally, in... Figures 2-7 In the diagram, the information and hydraulic transmission paths between the various components of the brake control device 10 and the wheel cylinders 15-18 are represented by solid lines, and by dotted lines, which represent paths that are not active.

[0033] Under normal conditions, the first indicator 40 and the second indicator 41 energize the first solenoid valve 34. Therefore, the first solenoid valve 34 is normally closed. Thus, under normal conditions, a first-stage hydraulic pressure P1 is generated by the first-stage actuator 31. Additionally, under normal conditions, a second-stage hydraulic pressure P2 is generated by the second-stage actuator 32.

[0034] On the other hand, under normal conditions, the third indicator 60 and the fourth indicator 61 energize the second solenoid valve 54. Therefore, the second solenoid valve 54 is in a closed state under normal conditions. Thus, under normal conditions, the third-wheel hydraulic pressure P3 is generated by the third-wheel actuator 51. In addition, under normal conditions, the fourth-wheel hydraulic pressure P4 is generated by the fourth-wheel actuator 52.

[0035] Furthermore, under normal conditions, the first indicator unit 40 calculates the target value of the first-round hydraulic pressure P1 (i.e., the first-round target hydraulic pressure P1*) and the target value of the third-round hydraulic pressure P3 (i.e., the third-round target hydraulic pressure P3*) based on the pedal travel, etc. The first indicator unit 40 then sends the calculated value of the first-round target hydraulic pressure P1* to the first drive circuit 42. The first drive circuit 42 adjusts the drive power of the first-round actuator 31 so that the calculated value of the first-round target hydraulic pressure P1* received from the first indicator unit 40 matches the detection value of the hydraulic pressure generated by the hydraulic sensor 37 on the first-round actuator 31. Additionally, the first indicator unit 40 sends the calculated value of the third-round target hydraulic pressure P3* to the third drive circuit 62. The third drive circuit 62 adjusts the drive power of the third-round actuator 51 so that the received calculated value of the third-round target hydraulic pressure P3* matches the detection value of the hydraulic pressure generated by the hydraulic sensor 37 on the third-round actuator 51. Furthermore, in this embodiment, the first instruction unit 40 sends the calculated value of the third round target hydraulic pressure P3* to the third drive circuit 62 via the in-vehicle network line 19 and the third instruction unit 60.

[0036] On the other hand, under normal conditions, the second indicator unit 41 calculates the target value of the second-wheel hydraulic pressure P2 (i.e., the second-wheel target hydraulic pressure P2*) and the target value of the fourth-wheel hydraulic pressure P4 (i.e., the fourth-wheel target hydraulic pressure P4*) based on the pedal travel, etc. Furthermore, the second indicator unit 41 sends the calculated value of the second-wheel target hydraulic pressure P2* to the second drive circuit 43. The second drive circuit 43 adjusts the drive power of the second-wheel actuator 32 so that the received calculated value of the second-wheel target hydraulic pressure P2* matches the detection value of the hydraulic pressure generated by the hydraulic sensor 38 on the second-wheel actuator 32. Additionally, the second indicator unit 41 sends the calculated value of the fourth-wheel target hydraulic pressure P4* to the fourth drive circuit 63. The fourth drive circuit 63 adjusts the drive power of the fourth-wheel actuator 52 so that the received calculated value of the fourth-wheel target hydraulic pressure P4* matches the detection value of the hydraulic pressure generated by the hydraulic sensor 37 on the fourth-wheel actuator 52. Furthermore, in this embodiment, the second instruction unit 41 sends the calculated value of the fourth wheel target hydraulic pressure P4* to the fourth drive circuit 63 via the in-vehicle network line 19 and the fourth instruction unit 61.

[0037] In normal operation, the first indicator unit 40 applies braking force to the first wheel 11 by calculating the target hydraulic pressure P1* of the first wheel and sending the calculated value. Similarly, in normal operation, the second indicator unit 41 applies braking force to the second wheel 12 by calculating the target hydraulic pressure P2* of the second wheel and sending the calculated value.

[0038] On the other hand, under normal conditions, the first indicator 40 calculates the target hydraulic pressure P3* for the third wheel and sends the target hydraulic pressure P3* to the third drive circuit 62 via the inter-brake communication 70. Similarly, the second indicator 41 indicates the braking force applied to the fourth wheel 14 under normal conditions.

[0039] (Diagnosis of abnormalities in the first instruction unit 40 and the second instruction unit 41)

[0040] In the braking control device 10, an anomaly diagnosis is performed to determine whether the first indicator 40 and the second indicator 41 are functioning properly. Next, an implementation method for such anomaly diagnosis will be described.

[0041] Furthermore, in this embodiment, the malfunction of the first wheel actuator 31 and the first drive circuit 42 also includes the case where the first indicator 40 fails to function properly. That is, in this embodiment, a malfunction in the function relating to applying braking force to the first wheel 11, corresponding to the normal indication of the first indicator 40, is considered a case where the first indicator 40 fails to function properly. Additionally, in this embodiment, the malfunction of the second wheel actuator 32 and the second drive circuit 43 also includes the case where the second indicator 41 fails to function properly. That is, in this embodiment, a malfunction in the function relating to applying braking force to the second wheel 12, corresponding to the normal indication of the second indicator 41, is considered a case where the second indicator 41 fails to function properly.

[0042] The first instruction unit 40 and the second instruction unit 41 self-diagnose whether they are functioning properly. If the first instruction unit 40 detects an abnormality within the range that it can maintain its self-diagnostic function, it notifies the second instruction unit 41, the third instruction unit 60, and the fourth instruction unit 61 of the abnormality. Similarly, if the second instruction unit 41 detects an abnormality within the range that it can maintain its self-diagnostic function, it notifies the first instruction unit 40, the third instruction unit 60, and the fourth instruction unit 61 of the abnormality.

[0043] Furthermore, the first indicator unit 40 and the second indicator unit 41 monitor each other to ensure they are functioning properly. Therefore, if either the first indicator unit 40 or the second indicator unit 41 experiences an abnormality, including a loss of self-diagnostic function, this abnormality can be confirmed. Moreover, if the first indicator unit 40 confirms that the second indicator unit 41 is not functioning properly, it notifies the third indicator unit 60 and the fourth indicator unit 61 of this abnormality. Similarly, if the second indicator unit 41 confirms that the first indicator unit 40 is not functioning properly, it notifies the third indicator unit 60 and the fourth indicator unit 61 of this abnormality.

[0044] Furthermore, if the reception of the calculated value of the third-round target hydraulic pressure P3* from the first instruction unit 40 is interrupted, the third instruction unit 60 determines that the first instruction unit 40 is not functioning properly. Similarly, if the reception of the calculated value of the fourth-round target hydraulic pressure P4* from the second instruction unit 41 is interrupted, the fourth instruction unit 61 determines that the second instruction unit 41 is not functioning properly.

[0045] (1. Operation of the braking control device 10 when the system malfunctions)

[0046] Next, refer to Figure 3 The operation of the braking control device 10 in the event of a system malfunction will be explained. Here, a system malfunction refers to a state where only one of the first indicator 40 and the second indicator 41 is functioning normally. Incidentally, Figure 3 This indicates the operating mode of the brake control device 10 when only the second indicator 41 of the first indicator 40 and the second indicator 41 functions normally.

[0047] Here, we will first explain the situation where the first indicator 40 malfunctions. If the second indicator 41 confirms that the first indicator 40 malfunctions, it will switch the first solenoid valve 34 to a de-energized state. As a result, the first solenoid valve 34 opens. Consequently, the cylinder 15 of the first wheel 11 and the cylinder 16 of the second wheel 12 are connected, and hydraulic pressure from both the first wheel hydraulic pressure P1 and the second wheel hydraulic pressure P2 can be generated by the second wheel actuator 32.

[0048] Furthermore, the second indicator unit 41 calculates the target hydraulic pressure P2* for the second wheel and the target hydraulic pressure P4* for the fourth wheel in the same manner as normally. The second indicator unit 41 sends the calculated value of the target hydraulic pressure P2* to the second drive circuit 43 and the calculated value of the target hydraulic pressure P4* for the fourth wheel to the fourth drive circuit 63. The second drive circuit 43 adjusts the drive power of the actuator 32 for the second wheel based on the calculated value of the target hydraulic pressure P2* received from the second indicator unit 41. As described above, the wheel cylinders 15 and 16 of the first wheel 11 and the second wheel 12 are interconnected at this time. Therefore, the second indicator unit 41 indicates the braking force applied to the first wheel 11, the second wheel 12, and the fourth wheel 14 respectively.

[0049] On the other hand, as described above, the third instruction unit 60 confirms that the first instruction unit 40 has malfunctioned based on notifications from the first instruction unit 40 or the second instruction unit 41. Additionally, the third instruction unit 60 determines that the first instruction unit 40 has malfunctioned if the reception of the calculated value of the third wheel target hydraulic pressure P3* is interrupted. If the third instruction unit 60 determines that the first instruction unit 40 has malfunctioned based on any of these conditions, it initiates the following malfunction control. During malfunction control, the third instruction unit 60 calculates the third wheel target hydraulic pressure P3* based on pedal travel, etc., and sends it to the third drive circuit 62. Therefore, in this case, the third instruction unit 60 instructs the braking force applied to the third wheel 13.

[0050] In contrast, when only the first indicator 40 and the second indicator 41 function normally, the brake control device 10 operates as follows: In this case, after de-energizing the first solenoid valve 34, the first indicator 40 calculates and sends the target hydraulic pressure P1* for the first wheel and the target hydraulic pressure P3* for the third wheel. Furthermore, if the fourth indicator 61 determines that the second indicator 41 has malfunctioned, it begins calculating the target hydraulic pressure P4* for the fourth wheel and sending its calculated value to the fourth drive circuit 63. Therefore, in this case, the first indicator 40 indicates the braking force applied to the first wheel 11, the second wheel 12, and the third wheel 13, respectively. Additionally, in this case, the fourth indicator 61 indicates the braking force applied to the fourth wheel 14.

[0051] (2. Operation of the braking control device 10 when the system malfunctions)

[0052] Next, refer to Figure 4 The operation of the braking control device 10 when the second system malfunctions will be explained. Here, the second system malfunction refers to a state in which neither the first indicator 40 nor the second indicator 41 functions properly.

[0053] As described above, if the third indicator 60 determines that the first indicator 40 has malfunctioned, it begins calculating the target hydraulic pressure P3* for the third wheel and sending its calculated value to the third drive circuit 62. Similarly, if the fourth indicator 61 determines that the second indicator 41 has malfunctioned, it begins calculating the target hydraulic pressure P4* for the fourth wheel and sending its calculated value to the fourth drive circuit 63. Therefore, in this case, the third indicator 60 indicates the braking force applied to the third wheel 13. Furthermore, in this case, the fourth indicator 61 indicates the braking force applied to the fourth wheel 14.

[0054] Furthermore, if the first indicator 40 and the second indicator 41 malfunction, the first solenoid valve 34 becomes de-energized. In this case, the first wheel hydraulic pressure P1 and the second wheel hydraulic pressure P2 cannot be generated by the first wheel actuator 31 and the second wheel actuator 32. In this situation, by configuring the main cylinder to connect with each wheel cylinder 15-16, the first wheel hydraulic pressure P1 and the second wheel hydraulic pressure P2 can be generated by the main cylinder. In this case, a main shut-off valve, which is normally open, is provided between each wheel cylinder 15-16 and the main cylinder. Moreover, when the first wheel hydraulic pressure P1 and the second wheel hydraulic pressure P2 are generated by at least one of the first wheel actuator 31 and the second wheel actuator 32, it is preferable to disconnect the connection between the main cylinder and each wheel cylinder 15-16 by the main shut-off valve.

[0055] Furthermore, in cases where the first indicator 40, second indicator 41, third indicator 60, and fourth indicator 61 all fail to function properly due to power loss, the brake control device 10 operates as follows: In this situation, both the first solenoid valve 34 and the second solenoid valve 54 are de-energized. In this case, by configuring the master cylinder to connect to each wheel cylinder 15-18 as described above, the master cylinder can generate first wheel hydraulic pressure P1, second wheel hydraulic pressure P2, third wheel hydraulic pressure P3, and fourth wheel hydraulic pressure P4. Furthermore, when the brake control device 10 operates in this manner, a main shut-off valve, which is a normally open solenoid valve, is provided between each wheel cylinder 15-18 and the master cylinder. Moreover, when generating first wheel hydraulic pressure P1, second wheel hydraulic pressure P2, third wheel hydraulic pressure P3, and fourth wheel hydraulic pressure P4 by any one of the four actuators, it is preferable to disconnect the master cylinder from the wheel cylinders 15-18 via the main shut-off valve.

[0056] (Effects of the implementation method)

[0057] The function and effects of this implementation method are explained.

[0058] In the braking control device 10 of this embodiment, under normal conditions, the first indicator 40 indicates the braking force applied to the first wheel 11 and the third wheel 13. Additionally, under normal conditions, the second indicator 41 indicates the braking force applied to the second wheel 12 and the fourth wheel 14. That is, under normal conditions, the first indicator 40 and the second indicator 41 respectively indicate the braking force of one front wheel and one rear wheel.

[0059] In addition to the two indicators that indicate braking force under normal conditions, the braking control device 10 of this embodiment also includes a third indicator 60 and a fourth indicator 61. In the following description, the first indicator 40 and the second indicator 41, which indicate braking force under normal conditions, will be referred to as the main indicators, and the third indicator 60 and the fourth indicator 61 will be referred to as backup indicators. Furthermore, in the following description, the ECU that malfunctions when the system malfunctions will be referred to as the malfunctioning main indicator, and the ECU that functions normally will be referred to as the normal main indicator.

[0060] Furthermore, in the following description, the assembly of the indicator, the drive circuit that directly transmits target hydraulic pressure to the indicator, the actuator driven by the drive circuit, and the wheel cylinder that is normally connected to the actuator is referred to as a system. The first braking unit 30 has two systems: a system consisting of a first indicator 40, a first drive circuit 42, and a first wheel actuator 31, and a system consisting of a second indicator 41, a second drive circuit 43, and a second wheel actuator 32. Similarly, the second braking unit 50 has two systems: a system consisting of a third indicator 60, a third drive circuit 62, and a third wheel actuator 51, and a system consisting of a fourth indicator 61, a fourth drive circuit 63, and a fourth wheel actuator 52.

[0061] Furthermore, in the event of a system malfunction where only one of the two main indicators functions normally, the normal main indicator and the backup indicator take over the supplementary instruction of the braking force to the two wheels provided by the malfunctioning main indicator. That is, when a system malfunction is caused by a malfunction of the second indicator 41, the first indicator 40 supplements the instruction of the braking force applied to the second wheel 12, and the fourth indicator 61 supplements the instruction of the braking force applied to the fourth wheel 14. Additionally, when a system malfunction is caused by a malfunction of the first indicator 40, the second indicator 41 supplements the instruction of the braking force applied to the first wheel 11, and the third indicator 60 supplements the instruction of the braking force applied to the third wheel 13.

[0062] Here, we consider the case where, in the event of a system malfunction, the normal main indicator unit supplements the function of the malfunctioning main indicator unit. In this case, when system 1 malfunctions, the normal main indicator unit must independently implement the braking force indication for all four wheels, which is normally handled by the two main indicator units. Therefore, in such a situation, each main indicator unit needs to have a high processing capacity capable of indicating the braking force for all four wheels.

[0063] To address this, consider the scenario where a backup indicator is used to supplement the main indicator's functionality during an anomaly. In this case, the backup indicator needs to have the same functionality as the main indicator. However, simply providing a backup indicator with high processing power for an anomaly is not cost-effective.

[0064] In this embodiment, the normal main indicator and the backup indicator supplement the function of the abnormal main indicator. Therefore, even without significantly increasing the processing capacity of the main indicator and the backup indicator, braking force control of each wheel can continue when the system malfunctions. Thus, the braking control device 10 according to this embodiment easily improves its resistance to malfunctions.

[0065] Furthermore, in the brake control device 10, when system 1 malfunctions, the first solenoid valve 34 is opened, connecting the wheel cylinders 15 and 16 of the first wheel 11 and the second wheel 12. This allows hydraulic pressure to be generated in both wheel cylinders 15 and 16 of the first wheel 11 and the second wheel 12 using only actuators belonging to the same system as the normal main indicator. Therefore, even if the number of wheels indicating braking force by the normal main indicator increases from two in normal operation to three in system 1 malfunction, the number of target hydraulic pressure values ​​calculated and the number of drive circuits sending the calculated values ​​remain at two. That is, the function required by the normal main indicator in system 1 malfunction is almost unchanged from that in normal operation. Furthermore, the braking force indicated by the main indicator for the first wheel 11 and the second wheel 12 is the same at this time.

[0066] Furthermore, in this embodiment, the third indicator 60 of the braking control device 10 determines that the first indicator 40 is not functioning properly based on the interruption of the transmission of the target hydraulic pressure P3* to the third drive circuit 62. Additionally, the fourth indicator 61 determines that the second indicator 41 is not functioning properly based on the interruption of the transmission of the target hydraulic pressure P4* to the fourth drive circuit 63. Moreover, the third and fourth indicators 60 initiate abnormality control based on their determinations. Therefore, in situations where the notification of an abnormality from the main indicator fails to arrive due to a communication error, or where the main indicator is unable to send a notification of an abnormality, the backup indicator can also implement abnormality control.

[0067] Furthermore, in the braking control device 10, when controlling vehicle sideslip suppression, the first wheel 11 and second wheel 12, which are the front wheels, require braking force control at a greater height than the third wheel 13 and fourth wheel 14, which are the rear wheels. On the other hand, the backup indicator of the braking force in the braking control device 10 of this embodiment only indicates the third wheel 13 and fourth wheel 14, which are the rear wheels. Moreover, in this embodiment, the first indicator 40 and second indicator 41, which are the main indicators, are mounted on the first braking unit 30, and the third indicator 60 and fourth indicator 61, which are backup indicators, are mounted on the second braking unit 50. Therefore, the function required for controlling the braking force at the height of the front wheels can be mounted only on the first braking unit 30, and the second braking unit 50 can be a simpler structure than the first braking unit 30.

[0068] (Regarding correspondence)

[0069] In this embodiment, the indicator that malfunctions when the system 1 is abnormal, which is the first main indicator, is the first indicator 40, and the indicator that functions normally is the second main indicator. Furthermore, one of the third indicator 60 and the fourth indicator 61 corresponds to the first backup indicator, and the other corresponds to the second backup indicator. Moreover, the third indicator 60 and the fourth indicator 61 constitute the backup indicator. In this embodiment, the first drive circuit 42 constitutes the first drive unit, the second drive circuit 43 constitutes the second drive unit, the third drive circuit 62 constitutes the third drive unit, and the fourth drive circuit 63 constitutes the fourth drive unit.

[0070] Furthermore, in this embodiment, a first switching mechanism is constituted by a first solenoid valve 34, which switches between a state that cuts off the connection between the cylinder 15 of the first wheel 11 and the cylinder 16 of the second wheel 12, and a state that allows the connection. Also in this embodiment, a second switching mechanism is constituted by a second solenoid valve 54, which switches between a state that cuts off the connection between the cylinder 17 of the third wheel 13 and the cylinder 18 of the fourth wheel 14, and a state that allows the connection.

[0071] (Other implementation methods)

[0072] This embodiment can be modified and implemented as follows. This embodiment and the following modifications can be combined and implemented with each other within the scope of technical inconsistency.

[0073] (Regarding the handling of system anomalies)

[0074] By configuring the brake control device 10 as described below, braking force control can continue even when the three systems malfunction. Here, a malfunction of the three systems refers to a state where only one of the third indicator 60 and the fourth indicator 61 functions normally.

[0075] When dealing with a malfunction in the three systems, firstly, it is necessary to be able to monitor each other through the third indicator 60 and the fourth indicator 61 to confirm whether they are functioning properly. Moreover, when a malfunction occurs in the three systems, by activating the brake control device 10 in the following manner, it is possible to continue controlling the braking force applied to the third wheel 13 and the fourth wheel 14.

[0076] exist Figure 5 The diagram illustrates the operation of the brake control device 10 in the event of an ECU malfunction other than the third indicator 60. If the third indicator 60 determines that an indicator other than itself is not functioning correctly, it de-energizes the second solenoid valve 54. This connects the wheel cylinders 17 and 18 of the third wheel 13 and the fourth wheel 14, enabling the generation of third-wheel hydraulic pressure P3 and fourth-wheel hydraulic pressure P4 via the third-wheel actuator 51. Furthermore, the third indicator 60 begins calculating the target third-wheel hydraulic pressure P3* and sending its calculated value to the third drive circuit 62. Thus, the braking force applied to the third wheel 13 and the fourth wheel 14 can be controlled solely by the remaining third indicator 60.

[0077] Furthermore, in the event of an abnormality in any of the indicators other than the fourth indicator 61, the second solenoid valve 54 is de-energized. Moreover, the fourth indicator 61 performs calculations on the target hydraulic pressure P4* of the fourth wheel and sends the calculated value to the fourth drive circuit 63. Thus, the braking force applied to the third wheel 13 and the fourth wheel 14 can be controlled solely by the remaining fourth indicator 61.

[0078] (Regarding the actions taken when a system malfunctions)

[0079] In the above embodiment, when the main indicator indicates the braking force of the front and rear wheels during normal operation, the main indicator also indicates the braking force of the front wheels, and the backup indicator indicates the braking force of the rear wheels. On the other hand, when system 1 malfunctions, the main indicator continues to indicate the braking force applied to both the front and rear wheels, just as it would during normal operation. When system 1 malfunctions, the main indicator may indicate the braking force applied to the two front wheels, and the backup indicator may indicate the braking force applied to the two rear wheels. Figure 6 The diagram illustrates an example of how the braking control device 10 operates when a system malfunctions under such circumstances. Additionally, in... Figure 7The diagram shows other examples of how the braking control device 10 operates when the system malfunctions under such circumstances.

[0080] exist Figure 6 In this case, the second indicator 41, acting as the normal main indicator, indicates the braking force applied to the first wheel 11 and the second wheel 12, which are the front wheels. Furthermore, the third indicator 60 indicates the braking force applied to the third wheel 13, and the fourth indicator 61 indicates the braking force applied to the fourth wheel 14. Specifically, the second indicator 41 de-energizes the first solenoid valve 34, connecting the wheel cylinders 15 and 16 of the first wheel 11 and the second wheel 12. Moreover, the second indicator 41 indicates the braking force applied to the first wheel 11 and the second wheel 12 by calculating the target hydraulic pressure P2* of the second wheel and sending its calculated value to the second drive circuit 43. Additionally, the third indicator 60 indicates the braking force applied to the third wheel 13 by calculating the target hydraulic pressure P3* of the third wheel and sending its calculated value to the third drive circuit 62. Finally, the fourth indicator 61 indicates the braking force applied to the fourth wheel 14 by calculating the target hydraulic pressure P4* of the fourth wheel and sending its calculated value to the fourth drive circuit 63.

[0081] exist Figure 7 In this case, the second indicator 41, which is also the normal main indicator, indicates the braking force applied to the first wheel 11 and the second wheel 12. On the other hand, in Figure 7 In this case, the third indicator 60 indicates the braking force applied to the third wheel 13 and the fourth wheel 14. Specifically, the third indicator 60 de-energizes the second solenoid valve 54, connecting the wheel cylinders 17 and 18 of the third wheel 13 and the fourth wheel 14. Furthermore, the third indicator 60 calculates the target hydraulic pressure P3* of the third wheel and sends its calculated value to the third drive circuit 62 to indicate the braking force applied to the third wheel 13 and the fourth wheel 14. Alternatively, the fourth indicator 61 can also indicate the braking force applied to the third wheel 13 and the fourth wheel 14 in this manner.

[0082] Alternatively, the braking force of the first wheel 11 and the second wheel 12 can be indicated based on the normal main indicator as follows: That is, the normal main indicator calculates the target hydraulic pressure P1* for the first wheel and the target hydraulic pressure P2* for the second wheel. Furthermore, the normal main indicator can also indicate the braking force applied to the first wheel 11 and the second wheel 12 respectively by sending the calculated value of the target hydraulic pressure P1* to the first drive circuit 42 and the target hydraulic pressure P2* to the second drive circuit 43. In this case, the normal main indicator can also calculate the target hydraulic pressure P1* and the target hydraulic pressure P2* independently. In this case, different braking forces can be generated on the left and right front wheels when system 1 malfunctions. Alternatively, the normal main indicator can calculate only one target hydraulic pressure and send the same value to the first drive circuit 42 and the second drive circuit 43. In this case, the increase in the processing load of the normal main indicator when system 1 malfunctions is suppressed.

[0083] In these cases, the backup indicator for system malfunction indicates the braking force applied to the third wheel 13 and the fourth wheel 14, which are the left and right rear wheels. In contrast, when the backup indicator directly supplements the function of the main indicator for malfunction, it must indicate the braking force applied to both the front and rear wheels. Even if the number of wheels indicating braking force is still two, when both wheels are rear wheels, the processing capacity of the backup indicator is reduced compared to the case where both wheels are front and rear wheels. Therefore, the processing capacity required by the backup indicator is suppressed. Furthermore, in these cases, the number of wheels indicating braking force in the normal main indicator for system malfunction is the same as in normal operation—two. Additionally, both wheels indicating braking force in the normal main indicator for system malfunction are front wheels. Therefore, the increase in processing capacity of the normal main indicator for system malfunction is suppressed.

[0084] (Regarding actuator control)

[0085] In the above embodiment, the actuators are controlled by adjusting the drive power of the actuators through the drive circuit so that the calculated value of the target hydraulic pressure based on the indicator matches the detected value of the generated hydraulic pressure by the hydraulic sensor. Actuator control can also be performed as follows: the indicator calculates the drive power based on the calculated value of the target hydraulic pressure and the detected value of the generated hydraulic pressure, and sends the calculated value to the drive circuit. Furthermore, the drive circuit can also control the actuators by supplying the drive power received from the indicator to the actuators.

[0086] (Other variations)

[0087] • In the above embodiment, the backup instruction unit is composed of the third instruction unit 60 and the fourth instruction unit 61, but it is also possible to use only one instruction unit as the backup instruction unit.

[0088] The first switching mechanism can also be constructed using multiple solenoid valves, which switches between a state where communication between cylinder 15 of the first wheel 11 and cylinder 16 of the second wheel 12 is cut off and a state where communication is allowed. Alternatively, a three-way valve can be provided that combines the functions of the first switching mechanism and the main shut-off valve. In this case, the three-way valve is connected to the main cylinder, wheel cylinder 15, and wheel cylinder 16 respectively. Furthermore, the three-way valve is configured to switch between a state where the three cylinders are hydraulically separated, a state where any two of the three cylinders are connected, and a state where all three cylinders are connected. Similarly, the second switching mechanism, which switches between a state where communication between cylinder 17 of the third wheel 13 and cylinder 18 of the fourth wheel 14 is cut off and a state where communication is allowed, can also be modified in the same way.

[0089] • The master cylinder can also be omitted, making it a complete two-line brake control device.

[0090] • The first-wheel actuator 31, the second-wheel actuator 32, the third-wheel actuator 51, and the fourth-wheel actuator 52 may also be electromechanical brakes (EMBs) that mechanically convert the power of the electric motor into braking force. In this case, the ECU, for example, calculates the target value of the electric motor output and sends it to the drive circuit of the EMB to indicate the braking force applied to the wheels.

[0091] In the above embodiment, a first indicator 40 and a second indicator 41, serving as main indicators, are mounted on the first braking unit 30. Additionally, a third indicator 60 and a fourth indicator 61, serving as backup indicators, are mounted on the second braking unit 50. The combination of the ECUs mounted on the first braking unit 30 and the second braking unit 50 can also be changed. For example, one main indicator and one backup indicator can be mounted on each of the first braking unit 30 and the second braking unit 50.

[0092] The first instruction unit 40, the second instruction unit 41, the third instruction unit 60, and the fourth instruction unit 61 can be configured as follows: They can be configured as one or more dedicated hardware circuits, such as a processor that operates according to a computer program, or dedicated hardware that performs at least a portion of various processes. Alternatively, they can be configured as a combination of the aforementioned processor and the aforementioned dedicated hardware circuit. Examples of dedicated hardware include, for instance, Application-Specific Integrated Circuits (ASICs). The processor includes a CPU and memories such as RAM and ROM, which store program code or instructions configured to cause the CPU to perform processes. The memory, i.e., the storage medium, includes all usable media accessible to general-purpose or special-purpose computers.

Claims

1. A braking control device for controlling the braking force applied to the wheels of a vehicle, wherein the wheels of the vehicle include a first wheel, a second wheel, a third wheel, and a fourth wheel. The aforementioned braking control device includes a first main indicator, a second main indicator, and a backup indicator as indicators of the braking force applied to the aforementioned wheels. When both the first and second main indicators are functioning normally, the first main indicator indicates the braking force applied to the first and third wheels, and the second main indicator indicates the braking force applied to the second and fourth wheels. In case of an abnormality, the second main indicator completes the instruction of the braking force applied to the first wheel, and the backup indicator completes the instruction of the braking force applied to the third wheel. The abnormality refers to the state in which only the second main indicator functions normally among the first main indicator and the second main indicator.

2. The braking control device according to claim 1, wherein, The first and second wheels mentioned above are the left and right front wheels, and the third and fourth wheels mentioned above are the left and right rear wheels. In the event of the above-mentioned abnormality, the backup indicator unit supplements the indication of the braking force applied to the fourth wheel.

3. The brake control device according to claim 1, wherein have: The first wheel uses an actuator to generate hydraulic pressure in the wheel cylinder of the first wheel; The second wheel uses an actuator to generate hydraulic pressure in the wheel cylinder of the second wheel; and The first switching mechanism switches between a state that disconnects the connection between the first wheel cylinder and the second wheel cylinder and a state that allows the connection. The aforementioned first main indicator unit indicates the braking force applied to the aforementioned first wheel by indicating the hydraulic pressure generated by the aforementioned first wheel actuator. The aforementioned second main indicator unit indicates the braking force applied to the second wheel by indicating the hydraulic pressure generated by the actuator of the second wheel. In the event of the aforementioned abnormality, the second main indicator switches the state of the first switching mechanism from the state of cutting off the connection to the state of allowing the connection, and indicates the braking force applied to the first wheel and the second wheel by indicating the generation of hydraulic pressure by the actuator of the second wheel.

4. The brake control device according to claim 2, wherein have: The first wheel uses an actuator to generate hydraulic pressure in the wheel cylinder of the first wheel; The second wheel uses an actuator to generate hydraulic pressure in the wheel cylinder of the second wheel; and The first switching mechanism switches between a state that disconnects the connection between the first wheel cylinder and the second wheel cylinder and a state that allows the connection. The aforementioned first main indicator unit indicates the braking force applied to the aforementioned first wheel by indicating the hydraulic pressure generated by the aforementioned first wheel actuator. The aforementioned second main indicator unit indicates the braking force applied to the second wheel by indicating the hydraulic pressure generated by the actuator of the second wheel. In the event of the aforementioned abnormality, the second main indicator switches the state of the first switching mechanism from the state of cutting off the connection to the state of allowing the connection, and indicates the braking force applied to the first wheel and the second wheel by indicating the generation of hydraulic pressure by the actuator of the second wheel.

5. The brake control device according to any one of claims 1 to 4, wherein have: The third wheel uses an actuator to generate hydraulic pressure in the wheel cylinder of the aforementioned third wheel; The fourth wheel uses an actuator to generate hydraulic pressure in the wheel cylinder of the aforementioned fourth wheel; as well as The second switching mechanism switches between a state that disconnects the connection between the cylinder of the third wheel and the cylinder of the fourth wheel and a state that allows the connection. The first main indicator unit indicates the braking force applied to the third wheel by indicating the hydraulic pressure generated by the actuator of the third wheel. The second main indicator unit indicates the braking force applied to the fourth wheel by indicating the hydraulic pressure generated by the actuator of the fourth wheel. In the event of the aforementioned abnormality, the backup indicator unit switches the state of the second switching mechanism from the state of cutting off the connection to the state of allowing the connection, and indicates the braking force applied to the third wheel and the fourth wheel by indicating the generation of hydraulic pressure by the actuator of the third wheel.

6. The braking control device according to claim 5, wherein, The backup indicator unit determines that the above-mentioned abnormality has occurred based on the interruption of the indication of hydraulic pressure generated from the first main indicator unit to the third wheel actuator.

7. The braking control device according to claim 5, wherein, The device includes a first backup indicator and a second backup indicator as backup indicators. The first backup indicator indicates the generation of hydraulic pressure on the third wheel actuator, and the second backup indicator indicates the generation of hydraulic pressure on the fourth wheel actuator. When only the first backup indicator is functioning normally among the first main indicator, the second main indicator, the first backup indicator, and the second backup indicator, the first backup indicator switches the state of the second switching mechanism from the state of cutting off the connection to the state of allowing the connection, and indicates the braking force applied to the third and fourth wheels by indicating the generation of hydraulic pressure on the actuator of the third wheel. When only the second backup indicator is functioning normally among the first main indicator, the second main indicator, the first backup indicator, and the second backup indicator, the second backup indicator switches the state of the second switching mechanism from the state of cutting off the connection to the state of allowing the connection, and indicates the braking force applied to the third and fourth wheels by indicating the generation of hydraulic pressure by the actuator of the fourth wheel.

8. The braking control device according to claim 6, wherein, The device includes a first backup indicator and a second backup indicator as backup indicators. The first backup indicator indicates the generation of hydraulic pressure on the third wheel actuator, and the second backup indicator indicates the generation of hydraulic pressure on the fourth wheel actuator. When only the first backup indicator is functioning normally among the first main indicator, the second main indicator, the first backup indicator, and the second backup indicator, the first backup indicator switches the state of the second switching mechanism from the state of cutting off the connection to the state of allowing the connection, and indicates the braking force applied to the third and fourth wheels by indicating the generation of hydraulic pressure on the actuator of the third wheel. When only the second backup indicator is functioning normally among the first main indicator, the second main indicator, the first backup indicator, and the second backup indicator, the second backup indicator switches the state of the second switching mechanism from the state of cutting off the connection to the state of allowing the connection, and indicates the braking force applied to the third and fourth wheels by indicating the generation of hydraulic pressure by the actuator of the fourth wheel.

9. The braking control device according to any one of claims 1 to 4, wherein, have: The first drive unit drives the actuator that brakes the first wheel. The second drive unit drives the actuator that brakes the second wheel. The third drive unit drives the actuator that brakes the aforementioned third wheel; as well as The fourth drive unit drives the actuator that brakes the aforementioned fourth wheel. The aforementioned first main indicator, second main indicator, first drive unit, and second drive unit are mounted on the first braking unit. The aforementioned backup indicator, the aforementioned third drive unit, and the aforementioned fourth drive unit are mounted on a second braking unit that is different from the aforementioned first braking unit.

10. The braking control device according to any one of claims 1 to 4, wherein, In the event of the aforementioned abnormality, the second main indicator unit provides instructions to ensure that the braking force applied to the first wheel is the same as the braking force applied to the second wheel.

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