Brake system

Abstract

The present invention addresses the problem of obtaining a brake control device that can assuredly decelerate and stop a vehicle during a failure of the brake control devices, has a simplified system configuration, and exhibits high reliability for use in automated driving. A brake device 101 according to the present invention comprises a first unit 102p, a second unit 102s, and a connection pipe 119. A first hydraulic unit includes a first cutoff valve 104p, a first pressure regulation part 105p, and a first control part 106p, while a second hydraulic unit includes a second cutoff valve 104s, a second pressure regulation part 105s, and a second control part 106s. This brake device is further provided with: a third pressure regulation unit 120p and a fourth pressure regulation unit 120s that regulate brake fluid pressures supplied from the first pressure regulation part 105p and the second pressure regulation part 105s to a plurality of first wheel cylinders 118a, 118d and a plurality of second wheel cylinders 118b, 118c, respectively; and third control parts 130p, 130s that control said pressure regulation parts.

Description

[Technical Field]

[0001] The present invention relates to a brake device compatible with automatic driving. [Background technology]

[0002] Regarding autonomous driving, according to the autonomous driving levels and responsibility allocation classifications specified in SAE_J3016, at so-called Level 3 and above, control responsibility is placed on the system side, and at Level 3, the driver has final operational responsibility in the event of a failure, but failure judgment and control transitions are guaranteed by the system. Furthermore, at Level 4 and above, all states are guaranteed by the system. Therefore, system components for autonomous driving must be highly reliable and must have redundancy to maintain functionality in the event of a failure.

[0003] Brake control devices also require redundancy to ensure the vehicle can decelerate and stop reliably in the event of a malfunction. Furthermore, considering the expansion of the limited operating range in autonomous vehicles, it is preferable for ABS (anti-lock braking system) and anti-skid functions to remain functional even if a single malfunction occurs in the brake control device. This is because it is impossible to determine the road conditions and vehicle motion state at the time of an accidental malfunction. Otherwise, the limited operating range must be restricted based on vehicle speed, weather conditions, road conditions, etc. Thus, to achieve ABS and anti-skid functions in addition to normal braking, a function to independently control the braking force of each wheel of the vehicle and a control device for this purpose are required. Patent Document 1 discloses a brake control device equipped with two hydraulic control units (a first hydraulic control unit and a second hydraulic control unit) as a redundant configuration.

[0004] In Patent Document 1, the first hydraulic control unit and the second hydraulic control unit have the same configuration, and each hydraulic control unit has a brake hydraulic pressure output section for independently braking four wheels, and the output section is connected to a wheel cylinder provided on each wheel. From the perspective of one wheel cylinder, it is connected to multiple hydraulic control devices, so that even if one hydraulic control unit fails, the other unit can continue to control the brakes. This achieves redundancy, maintaining the hydraulic control function for each of the four wheels in the event of a failure. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] US 2018 / 0334150 A1 Summary of the Invention [Problem to be solved by the invention]

[0006] In the conventional brake control device described above, each wheel cylinder is connected to two hydraulic output devices, so when the system is normal, the two hydraulic control units must operate in coordination, which may complicate the hydraulic control rules.

[0007] Furthermore, because each wheel cylinder is connected to two hydraulic output devices, if a failure occurs in one hydraulic control unit, the resulting hydraulic disturbance may directly affect the other hydraulic control unit via the piping. From this perspective, the hydraulic control law must be designed to take into account the disturbance factors from other units in response to various failure modes, which could complicate the state transitions during fail-safe operation.

[0008] An object of the present invention is to provide a brake device that can reliably generate wheel cylinder hydraulic pressure for all FR to RR wheels even in the event of such a failure, reliably decelerate and stop the vehicle, and further has a hydraulic pressure control function for each of the four wheels while simplifying the hydraulic pressure control rules, thereby providing high reliability for autonomous driving. [Means for solving the problem]

[0009] In order to solve the above problem, the brake device of the present invention is a brake device mounted on a vehicle, a first hydraulic unit that supplies brake fluid to a plurality of first wheel cylinders; a second hydraulic unit that supplies brake fluid to the second wheel cylinders; a connecting pipe that connects the first hydraulic pressure unit and the second hydraulic pressure unit and allows the brake fluid to flow, The first hydraulic unit is a first shutoff valve that shuts off the flow of the brake fluid between the connecting pipe and the brake fluid supply pipe; a first pressure adjusting unit that adjusts the pressure of the brake fluid supplied to the plurality of first wheel cylinders; a first control unit that controls opening and closing of the first shutoff valve and the first pressure adjusting unit, The second hydraulic unit is a second shutoff valve that shuts off the flow of the brake fluid between the connecting pipe and the brake fluid supply pipe; a second pressure adjusting unit that adjusts the pressure of the brake fluid supplied to the plurality of second wheel cylinders; a second control unit that controls opening and closing of the second shutoff valve and the second pressure adjusting unit, a third pressure adjusting unit that adjusts the brake fluid pressures supplied from the first pressure adjusting unit to the first wheel cylinders; a fourth pressure adjusting unit that adjusts the brake fluid pressures supplied from the second pressure adjusting unit to the second wheel cylinders; a third control unit that controls the third pressure adjusting unit and the fourth pressure adjusting unit; The present invention is characterized by comprising: [Effects of the Invention]

[0010] According to the present invention, if a failure occurs in one of the two hydraulic units, the discharge hydraulic pressure of the other hydraulic unit is supplied to one of the hydraulic units through the connecting pipe, and at that time, the brake hydraulic pressure supplied to each wheel cylinder is adjusted, thereby controlling the hydraulic pressure at each of the four wheels, thereby achieving higher reliability as a brake device. Further features related to the present invention will become apparent from the description of the present specification and the accompanying drawings. In addition, problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram showing the configuration of a hydraulic pressure control system according to a first embodiment. [Figure 2] 4 is a flowchart showing the flow of brake control processing in the control unit in the first embodiment. [Figure 3] 4 is a flowchart showing the flow of brake control processing in the control unit in the first embodiment. [Figure 4] FIG. 10 is a diagram showing the configuration of a hydraulic pressure control system according to a second embodiment. [Figure 5] FIG. 10 is a diagram showing a modified example of the configuration of the hydraulic pressure control system of the second embodiment. [Figure 6] FIG. 10 is a diagram showing the configuration of a hydraulic pressure control system according to a third embodiment. [Figure 7] FIG. 10 is a diagram showing the configuration of a hydraulic pressure control system according to a fourth embodiment. [Figure 8] FIG. 10 is a diagram showing the configuration of a hydraulic pressure control system according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] [Embodiment 1] FIG. 1 is a configuration diagram of a hydraulic pressure control system 101 according to the first embodiment. The hydraulic control system 101 is a system intended for application primarily to Level 4 or higher autonomous vehicles, and constitutes a brake device mounted on the vehicle. In each part of FIG. 1 , the suffix p of a reference symbol indicates that it corresponds to the primary system (P system) of the wheel cylinder 118. The suffix s of a reference symbol indicates that it corresponds to the secondary system (S system) of the wheel cylinder 118. Hereinafter, when there is no distinction between the P and S systems, the p and s will be omitted. The suffix a of a reference symbol indicates that it corresponds to the left front wheel FL. Similarly, the suffix b of a reference symbol indicates that it corresponds to the right front wheel FR, the suffix c of a reference symbol indicates that it corresponds to the left rear wheel RL, and the suffix d of a reference symbol indicates that it corresponds to the right rear wheel RR. When there is no distinction between the individual wheels FL to RR, the suffix a, b, c, and d will be omitted. The suffix f of a reference symbol indicates that it corresponds to the front wheels FL / FR, and the suffix r of a reference symbol indicates that it corresponds to the rear wheels RL / RR. When there is no distinction between the front wheels and the rear wheels, the suffix f and r will be omitted.

[0013] The hydraulic pressure control system 101 applies braking force to each of the wheels FL to RR by generating brake hydraulic pressure (wheel cylinder hydraulic pressure) in wheel cylinders (braking force application units) 118, which press the brake pads provided on each of the wheels FL to RR against brake discs provided on the wheel side. Wheel cylinders 118 are provided on each of the four wheels.

[0014] The hydraulic control system 101 includes a first unit 102p and a second unit 102s. Each of the first unit 102p and the second unit 102s is a unit in which a pressure source 103, a shutoff valve 104, a pressure adjusting means 105, wheel pressure adjusting means 120, a main controller 106, and a sub-controller 130 are integrally provided.

[0015] The first unit 102p and the second unit 102s have a unit connection port 113, a suction port 114, and a wheel cylinder port 115.

[0016] The unit connection port 113 is connected to a unit connection pipe 119, and is connected to the shutoff valve 104 via a connection liquid path 111. The first unit 102p and the second unit 102s are connected via the unit connection pipe 119.

[0017] The suction port 114 is connected to a suction hose 116, and is connected to a pressure source 103 via a connecting fluid path 112. The first unit 102p and the second unit 102s are also connected to a reservoir tank 107 via the suction hose 116. The reservoir tank 107 is a brake fluid source that stores brake fluid, and is a low-pressure part that is open to atmospheric pressure.

[0018] Wheel cylinder port 115 is connected to wheel cylinder piping 117, connected to each wheel pressure regulating means 120 via connecting fluid passage 121, and further connected to pressure regulating means 105 via 110. Furthermore, first unit 102p and second unit 102s are each connected to wheel cylinder 118 via wheel cylinder piping 117. A so-called X (cross) piping configuration is adopted, in which the primary system of first unit 102p is connected to left front wheel cylinder 118a and right rear wheel cylinder 118d, while the secondary system of second unit 102s is connected to right front wheel cylinder 118b and left rear wheel cylinder 118c. Note that H piping may also be used, connecting the front wheels to the primary system and the rear wheels to the secondary system.

[0019] The pressure source 103 and the pressure adjusting means 105 are connected via a connecting liquid path 108. The shutoff valve 104 and the pressure adjusting means 105 are connected via a connecting liquid path 109.

[0020] Based on a command from a main controller 106, the pressure source 103 draws in brake fluid stored in a reservoir tank 107 and discharges the required flow rate to a pressure adjusting means 105.

[0021] Based on a command from the main controller 106, the pressure adjusting means 105 adjusts the pressure of the brake fluid supplied from the pressure source 103 and outputs the desired pressure to the wheel cylinder 118 side and the shutoff valve 104 side. Here, in the pressure adjusting means 105, the connecting fluid path 109 and the connecting fluid path 110 are connected (not shown in the drawing). The pressure adjusting means 105 is configured to be able to independently control the hydraulic pressure of the wheel cylinder 118 to which the pressure is output.

[0022] The shutoff valve 104 opens / closes based on a command from the main controller 106, thereby connecting / blocking communication between the connecting liquid path 109 and the connecting liquid path 111. The shutoff valve 104 has a so-called normally open structure, and when there is no command (electrical signal) from the main controller 106 and it is not energized, it is open, i.e., the connecting liquid path 109 and the connecting liquid path 111 are in an open state (connected).

[0023] Each wheel pressure adjusting means 120 is a backup pressure adjusting means (redundant each wheel pressure adjusting means) in case an abnormality occurs in the system and it becomes impossible to control the braking force (hydraulic pressure) of each wheel using only the pressure source 103, the shutoff valve 104, and the pressure adjusting means 105. Each wheel pressure adjusting means 120 adjusts the brake fluid pressure supplied to each of the plurality of wheel cylinders.

[0024] The main controller 106 receives signals (target brake hydraulic pressure) from other ECUs via communication means. It also has applications for preventing unstable vehicle behavior, specifically ABS and anti-skid functions, and has the function of monitoring vehicle behavior, wheel speed, etc., and adjusting the braking force of each wheel as necessary. It controls the pressure source 103, shut-off valve 104, and pressure regulating means 105 to adjust the hydraulic pressure to achieve the desired braking force, thereby controlling the hydraulic pressure of each wheel. The main controller 106 is composed of a microcontroller, actuator driver, communication means, software, etc.

[0025] The sub-controller 130 controls each wheel pressure adjusting means 120 and is composed of a microcontroller, an actuator driver, a communication means, software, etc. Two power systems (first power supply and second power supply), power supply system 1 and power supply system 2, are connected to the sub-controller 130. The sub-controller 130 is configured to be contained within a single ECU together with the main controller 106, but the functions of the sub-controller 130 and the main controller 106 are independent and are configured so that they are not affected by each other's failures.

[0026] Wheel cylinders 118a and 118d of this embodiment correspond to the multiple first wheel cylinders in the claims, wheel cylinders 118b and 118c of this embodiment correspond to the multiple second wheel cylinders in the claims, first unit 102p and second unit 102s of this embodiment correspond to the first hydraulic unit and the second hydraulic unit in the claims, and unit connection pipe 119 of this embodiment corresponds to the connection pipe in the claims. Shutoff valves 104p and 104s of this embodiment correspond to the first shutoff valve and the second shutoff valve in the claims, and main controllers 106p and 106s of this embodiment correspond to the first control unit and the second control unit in the claims. A configuration in which pressure sources 103p and 103s and pressure regulating means 105p and 105s of this embodiment are combined corresponds to the first pressure regulating unit and the second pressure regulating unit in the claims. In addition, the wheel pressure adjusting means 120p and 120s in this embodiment correspond to the third and fourth pressure adjusting sections in the claims, the sub-controller 130 corresponds to the third control section, and the sub-controllers 130p and 130s correspond to the fourth and fifth control sections.

[0027] Next, the operation of the hydraulic pressure control system 101 of the first embodiment will be described. (Normal control when the system is normal) In the first unit 102p and the second unit 102s, the shutoff valve 104 closes in response to a command from the main controller 106, blocking communication between the connecting fluid path 109 and the connecting fluid path 111. The main controller 106 also controls the pressure source 103 and the pressure adjusting means 105 to output the desired pressure to the wheel cylinder 118, thereby applying the necessary braking force to each of the wheels FL to RR of the wheel cylinder 118. At this time, the wheel pressure adjusting means 120 does not perform any operation. Therefore, the connecting fluid paths 110 and 121 are at exactly the same pressure, and the output result of the pressure adjusting means 105 is directly reflected in the wheel cylinder 118.

[0028] When the main controller 106 detects unstable vehicle behavior and requires braking force application by the ABS or anti-skid function, the pressure regulating means 105 supplies the necessary pressure to the wheel cylinders 118 to apply the necessary braking force to each of the wheels FL to RR. In this case, in the application software for the ABS or anti-skid function, the control intervention decision and braking force operation amount calculation can be performed by at least one of the first unit 102p and the second unit 102s. For example, if the main controller 106p of the first unit 102p mainly performs the control calculation, the hydraulic pressure command value for the wheel cylinders 118b / 118c connected to the second unit 102s can be transmitted to the main controller 106s via a communication means and controlled by the main controller 106s. Conversely, the second unit 102s may mainly perform the calculation and transmit the hydraulic pressure command value to the first unit 102p. Alternatively, the first unit 102p and the second unit 102s may independently determine control intervention and operation. This combination is possible because it consists of two hydraulic units with the same function.

[0029] (Backup control in case of system failure) Here, as an example, a process performed by the main controller 106 when the pressure adjusting means of the second unit 102s fails (breaks down) will be described with reference to the flowchart of FIG.

[0030] In step S401, it is determined whether the second unit 102s is capable of hydraulic pressure control. This determination is made by the pressure source 103, the shutoff valve 104, the pressure adjusting means 105, and a fault detection logic (not shown) of the main controller 106, which are incorporated in the main controller 106. If it is determined that hydraulic pressure control is possible, the process proceeds to step S402, and if it is determined that hydraulic pressure control is not possible, i.e., a system failure, the process proceeds to step S403.

[0031] In step S402, the normal control when the system is normal, as described above in

[0027] , is continued.

[0032] In step S403, the process shifts to backup control, and the process proceeds to step S404. As a result, the shutoff valve 104p of the first unit 102p is opened. This operation establishes communication between the connecting fluid path 109p and the connecting fluid path 111p, and the pressure regulated by the pressure regulating means 105p is applied to the unit connection port 113s of the second unit 102s via the unit connection pipe 119 together with the wheel cylinders 118a / 118d.

[0033] In step S404, the system notifies the sub-controller 130 that the system has transitioned to backup control, and transmits the target hydraulic pressure for each wheel via communication means 1 or 2 (first communication unit or second communication unit). Each wheel pressure adjusting means 120 recognizes that backup control is in effect and controls the hydraulic pressure of each wheel cylinder.

[0034] Furthermore, when the second unit 102s determines that there is a system failure, the pressure source 103s, the shutoff valve 104s, and the pressure adjusting means 105s are all deactivated (de-energized), the shutoff valve 104s opens, and the connecting liquid path 109s and the connecting liquid path 111s communicate with each other. In other words, when the main controllers 106p and 106s detect a failure of either the first unit 102p or the second unit 102s, they open both the shutoff valves 104p and 104s, respectively.

[0035] Therefore, the pressure adjusted by the pressure adjustment means 105p of the first unit 102p flows not only through the connecting liquid path 110a / 110d, but also through the connecting liquid path 111p, the unit connection port 113p, and the connecting liquid path 119, into the unit connection port 113s of the second unit 102s, and is applied to the connecting liquid path 111s, the connecting liquid path 109s, the pressure adjustment means 105s, and the connecting liquid paths 110b / 110c.

[0036] Next, the processing performed by the sub-controller 130 will be described with reference to the flowchart of FIG. This process is performed by the sub-controllers 130p / 130s of the first unit 102p and the second unit 102s, respectively. The sub-controller 130 is configured to be independent of the main controller 106 and not be affected by failures. Even if the main controller 106s of the second unit 102s fails and is unable to regulate pressure, the sub-controller 130s and each wheel pressure regulating means 120s are configured to continue to function. For example, when the sub-controller 130s detects a failure of the main controller 106s, it controls each wheel pressure regulating means 120p and each wheel pressure regulating means 120s in cooperation with the pressure regulating means 105p. Furthermore, when the sub-controller 130p detects a failure of the main controller 106p, it controls each wheel pressure regulating means 120p and each wheel pressure regulating means 120s in cooperation with the pressure regulating means 105s.

[0037] In step S501, it is determined whether the system is in a backup state. This is determined based on whether some kind of failure has occurred in the pressure regulation system of the first unit 102p or the second unit 102s, requesting backup control (flowchart in FIG. 2). In step S501, if it is determined that the system is not in a backup control state (i.e., the system is normal), the process proceeds to step S502.

[0038] In step S502, the normal control when the system is normal, as described above in

[0027] , is continued. That is, each wheel pressure adjusting means 120 is not operated, and the pressure adjusted by the pressure adjusting means 105 is transmitted to the wheel cylinder 118 as is.

[0039] If it is determined in step S501 that the backup control state is in effect, the process proceeds to step S503. In step S503, the hydraulic pressure target for each wheel is received. In this case, the hydraulic pressure target for each wheel based on the calculation result of the first unit 102p is received via communication means 1 or 2. Next, the process proceeds to step S504.

[0040] In step S504, each wheel pressure adjusting means 120 adjusts the pressure to the received wheel hydraulic pressure. As described above in

[0032] , the brake fluid supplied from the pressure source 103p of the normal system can be transmitted to the connecting fluid passages 110 of the first unit 102p and the second unit 102s, so all that remains is to distribute it to each wheel cylinder 118. To achieve this, each wheel pressure adjusting means 120 adjusts the pressure of the brake fluid supplied to the connecting fluid passages 110, and ultimately adjusts the hydraulic pressure of each wheel.

[0041] As described above, the hydraulic pressure in the connecting fluid passages 110a / 110d of the first unit 102p is further adjusted by each wheel pressure adjusting means 120p and is applied to wheel cylinders 118a / 118d via connecting fluid passages 121a / 121d, wheel cylinder ports 115a / 115d, and wheel cylinder piping 117a / 117d. The hydraulic pressure in the connecting fluid passages 110b / 110c of the second unit 102s is further adjusted by each wheel pressure adjusting means 120s and is applied to wheel cylinders 118b / 118c via connecting fluid passages 121b / 121c, wheel cylinder ports 115b / 115c, and wheel cylinder piping 117b / 117c.

[0042] As a result, even if the second unit 102s fails, the desired pressure is output to each wheel cylinder 118a to 118d, just as when the system is normal, and the required braking force can be applied independently to each wheel FL to RR of the wheel cylinder 118.

[0043] Note that the above is an example of the case where the second unit 102s fails, but even if the first unit 102p fails, the operation itself is the same except that the first unit 102p and the second unit 102s are swapped in the processing of step S403 above.

[0044] Next, the effects of the first embodiment will be described. The hydraulic control system 101 of embodiment 1 has two hydraulic units (identical units) having the same configuration, namely, a first unit 102p and a second unit 102s, where the first unit 102p has a main controller 106p and the second unit 102s has a main controller 106s, and each unit 102 is provided with a shut-off valve 104 that is controlled only by the main controller 106 of each unit 102, and the upstream side (opposite the wheel cylinder) of the shut-off valve 104 provided in each unit 102 is connected by a unit connection pipe 119.

[0045] In this way, the two units 102p, 102s and the main controllers 106p, 106s, which are the ECUs possessed by each unit 102p, 102s, are separated. Therefore, even if a failure occurs in one of the units / ECUs, the failure will not affect the other unit / ECU. Therefore, the discharge hydraulic pressure from the other unit can be supplied to all wheels FL to RR, ensuring braking force.

[0046] Furthermore, by providing each hydraulic unit 102p, 102s with a wheel pressure adjusting means 120 and a sub-controller 130 that controls it, it is possible to adjust the hydraulic pressure generated in the hydraulic unit individually at each wheel, making it possible to redundantly continue braking force control such as more advanced ABS and anti-skid functions, thereby achieving higher reliability as a braking device.

[0047] Furthermore, although the two units have the same configuration, they operate independently via shutoff valve 104 when the system is operating normally, so the first and second units can be configured to control only the hydraulic pressure control of the wheel cylinders connected to them, simplifying the consideration of control and the impact of failures. This also has the advantage of simplifying the system configuration.

[0048] [Embodiment 2] Next, a second embodiment of the present invention will be described with reference to Fig. 4. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. 4 is a configuration diagram of a hydraulic control system 201 of the second embodiment, which shows more specific hydraulic circuit components than those of the first embodiment. As with the first embodiment, this system is intended to be applied mainly to autonomous vehicles of Level 4 or higher.

[0049] The hydraulic control system 201 generates brake hydraulic pressure (wheel cylinder hydraulic pressure) in the wheel cylinders (braking force applying units) 218a to 218d, thereby pressing the brake pads provided on each wheel FL to RR against the brake discs provided on the wheel side, thereby applying braking force to each wheel FL to RR.

[0050] The hydraulic pressure control system 201 includes a first unit 202p and a second unit 202s. Each of the first unit 202p and the second unit 202s is a unit in which a pressure source 203, a shutoff valve 204, a pressure adjusting means 205, each wheel pressure adjusting means 265, and an ECU 250 are integrally provided.

[0051] The first unit 202p and the second unit 202s have a unit connection port 213, a suction port 214, and a wheel cylinder port 215.

[0052] The unit connection port 213 is connected to a unit connection pipe 219, and is connected to the shutoff valve 204 via a connection liquid path 211. The first unit 202p and the second unit 202s are connected to each other via the unit connection pipe 219.

[0053] In the configuration example shown in Fig. 4, two unit connection pipes 219f and 219r are used. The unit connection pipe 219f connects the unit connection port 213a of the first unit 202p to the unit connection port 213b of the second unit 202s, and the unit connection pipe 219r connects the unit connection port 213d of the first unit 202p to the unit connection port 213c of the second unit 202s. As another configuration example, as shown in Fig. 5, the first unit 202p and the second unit 202s may be connected by a single unit connection pipe 219f, and the connection liquid paths 211a and 211b may branch into the connection liquid paths 211e and 211f inside the first unit 202p and the second unit 202s. According to the configuration example shown in Fig. 5, the number of connection pipes can be reduced to one compared to the configuration example shown in Fig. 4, thereby reducing the number of parts and the number of processes.

[0054] The suction port 214 is connected to a suction hose 216, and is connected to a pressure source 203 via a connecting fluid path 212. The first unit 202p and the second unit 202s are connected to a reservoir tank 207 via the suction hose 216. Specifically, the reservoir tank 207 is divided into two compartments, with a primary fluid chamber 257p connected to the first unit 202p and a secondary fluid chamber 257s connected to the second unit 202s. The reservoir tank 207 is a brake fluid source that stores brake fluid, and is a low-pressure section that is open to atmospheric pressure.

[0055] Wheel cylinder port 215 is connected to wheel cylinder piping 217 and to pressure regulating means 205 via connecting fluid passage 210. Each wheel pressure regulating means 265 is provided on connecting fluid passage 210. First unit 202p and second unit 202s are connected to wheel cylinder 218 via wheel cylinder piping 217. A so-called X (cross) piping configuration is adopted, in which the primary system of first unit 202p is connected to left front wheel cylinder 218a and right rear wheel cylinder 218d, while the secondary system of second unit 202s is connected to right front wheel cylinder 218b and left rear wheel cylinder 218c. Note that an H-shaped piping configuration may also be used, connecting the front wheels to the primary system and the rear wheels to the secondary system.

[0056] The pressure source 203 and the pressure adjusting means 205 are connected via a connecting liquid path 208. The shutoff valve 204 and the pressure adjusting means 205 are connected via a connecting liquid path 209.

[0057] The pressure source 203 is composed of a pump 223 and a motor 233 that drives the pump. Based on a command from a main controller 206 of the ECU 250, the rotation of the motor 233 is controlled to suck in brake fluid stored in a reservoir tank 207 and discharge the required flow rate to the pressure adjusting means 205.

[0058] The pressure adjusting means 205 is composed of a pressure increase control valve 225, a pressure decrease control valve 235, a communication valve 245, a pressure sensor 255, and a pressure sensor 266, and adjusts the pressure of the brake fluid supplied from the pressure source 203 based on a command from the main controller 206 of the ECU 250. That is, the pressure detected by the pressure sensors 255 / 266 is fed back, and when increasing the pressure, the pressure increase control valve 225 is opened and the pressure decrease control valve 235 is closed, and when decreasing the pressure, the pressure increase control valve 225 is closed and the pressure decrease control valve 235 is opened, thereby obtaining the desired pressure. The adjusted pressure is output to the wheel cylinder 218 and to the shutoff valve 204 side by opening the communication valve 245. Each wheel cylinder 218 is assigned one pressure increase control valve 225, one pressure decrease control valve 235, one communication valve 245, and one pressure sensor 255. For example, pressure increase control valve 225a, pressure decrease control valve 235a, communication valve 245a, and pressure sensor 255a are assigned to FL wheel cylinder 218a. Therefore, the brake fluid supplied from pressure source 203 can be independently adjusted to a desired pressure in the wheel cylinder of each wheel. Therefore, hydraulic pressure control system 201 can independently adjust the pressure in all four wheels.

[0059] The shutoff valve 204 opens / closes based on a command from the main controller 206 of the ECU 250, thereby connecting / blocking communication between the connecting fluid path 209 and the connecting fluid path 211. The shutoff valve 204 has a so-called normally open structure, and is open when there is no command (electrical signal) from the ECU 250 and when it is not energized, i.e., the connecting fluid path 209 and the connecting fluid path 211 are in an open state (connected).

[0060] Each wheel pressure adjusting means 265 is composed of a backup pressure increasing valve 260 and a backup pressure reducing valve 261. Based on a command from sub-controller 230 of ECU 250, backup pressure increasing valve 260 can control the amount of pressure increase by restricting the inflow to wheel cylinder 218 in response to the flow rate generated in connecting fluid path 210 during backup control. Backup pressure reducing valve 261 can control the amount of pressure reduction in wheel cylinder 218 by causing the pressure generated in the wheel cylinder to flow out to connecting fluid path 222. Therefore, as long as there is a means for flowing brake fluid into connecting fluid path 210, it is possible to continue adjusting the pressure at each wheel.

[0061] The ECU 250 is an electronic control unit (ECU) that controls the first unit 202p and the second unit 202s, and is composed of a main controller 206 and a sub-controller 230.

[0062] The main controller 206 receives signals (target brake hydraulic pressure) from other ECUs via communication means. It also includes applications for preventing unstable vehicle behavior, specifically ABS and anti-skid functions, and has the function of monitoring vehicle behavior, wheel speed, etc., and adjusting the braking force of each wheel as necessary. It controls the hydraulic pressure of each wheel by controlling the pressure source 203, shutoff valve 204, and pressure regulator 205 so that the hydraulic pressure achieves the desired braking force.

[0063] The sub-controller 230 controls each wheel pressure adjusting means 265 and is composed of a microcontroller, an actuator driver, a communication means, software, etc. Two power systems, power supply system 1 and power supply system 2, are connected to the sub-controller 230. Although they are contained within a single ECU, the functions of the sub-controller 230 and the main controller 206 are independent, and are configured so that they are not affected by each other's failures.

[0064] Wheel cylinders 218a and 218d of this embodiment correspond to the first wheel cylinders in the claims, wheel cylinders 218b and 218c of this embodiment correspond to the second wheel cylinders in the claims, first unit 202p and second unit 202s of this embodiment correspond to the first hydraulic unit and the second hydraulic unit in the claims, and unit connection pipe 219 of this embodiment corresponds to the connection pipe in the claims. Shut-off valves 204p and 204s of this embodiment correspond to the first shut-off valve and the second shut-off valve in the claims, and main controllers 206p and 206s of this embodiment correspond to the first control unit and the second control unit in the claims. The combined configuration of pressure sources 203p and 203s and pressure adjustment units 205p and 205s of this embodiment corresponds to the first pressure adjustment means and the second pressure adjustment means in the claims. In addition, the wheel pressure adjusting means 265a / 265d, 265b / 265c of this embodiment correspond to the third pressure adjusting means and the fourth pressure adjusting means in the claims, the sub-controller 230 corresponds to the third control unit, and the sub-controllers 230p / 230s correspond to the fourth control unit and the fifth control unit.

[0065] Next, the operation of the hydraulic pressure control system 201 of the second embodiment will be described. (Normal control when the system is normal) In the first unit 202p and the second unit 202s, the shutoff valve 204 closes in response to a command from the main controller 206 of the ECU 250, blocking communication between the connecting fluid path 209 and the connecting fluid path 211. The ECU 250 also controls the pressure source 203 and the pressure adjusting means 205 to output a desired pressure to the wheel cylinder 218, thereby applying the necessary braking force to each of the wheels FL to RR of the wheel cylinder 218. At this time, each wheel pressure adjusting means 265 is in a standby state where it does nothing, and the pressure generated by the pressure adjusting means 205 is transmitted directly to the wheel cylinder 218.

[0066] When main controller 206 detects unstable vehicle behavior and braking force application is required by ABS or anti-skid function, pressure regulating means 205 supplies the necessary pressure to wheel cylinders 118 to apply the necessary braking force to each of wheels FL-RR. In this case, in the application of ABS or anti-skid function, control intervention determination and braking force operation amount calculation can be performed by at least one of first unit 202p and second unit 202s. For example, when main controller 206p of first unit 202p mainly performs control calculation, hydraulic pressure command values ​​for wheel cylinders 218b / 218c connected to second unit 202s can be transmitted to main controller 206s via communication means and controlled by main controller 206s. Conversely, main controller 206s of second hydraulic unit 202s may mainly perform calculation and transmit hydraulic pressure command values ​​to first unit 202p. Alternatively, the controllers of the first unit 202p and the second unit 202s may independently determine control intervention and operation. Such a combination is possible because two units with the same function are provided.

[0067] (Backup control in case of system failure) Here, as an example, a process performed by the main controller 206 of the ECU 250 when the second unit 202s fails will be described with reference to the flowchart of FIG.

[0068] In step S401, it is determined whether the second unit 202s is capable of hydraulic pressure control. This determination is made by the pressure source 203, the shutoff valve 204, the pressure adjusting means 205, and a failure detection logic (not shown) of the ECU 250, which are incorporated in the main controller 206p of the ECU 250p. If it is determined that hydraulic pressure control is possible, the process proceeds to step S402. If it is determined that hydraulic pressure control is not possible, i.e., a system failure, the process proceeds to step S403.

[0069] In step S402, the normal control when the system is normal, as described above in

[0065] , is continued.

[0070] In step S403, the process shifts to backup control. That is, the shutoff valves 204a / 204d of the first unit 202p are opened. This operation establishes communication between the connecting fluid path 209a and the connecting fluid path 211a, and between the connecting fluid path 209d and the connecting fluid path 211d, and the pressure regulated by the pressure regulating means 205a / 205d is applied to the unit connection ports 213b / 213c of the second unit 202s via the unit connection pipe 219 together with the wheel cylinders 218a / 218d.

[0071] In step S404, the system notifies the sub-controller 130 that the system has transitioned to backup control, and transmits the target hydraulic pressure for each wheel via communication means 1 or 2. Each wheel pressure adjusting means 265 recognizes that backup control is in effect and controls the hydraulic pressure in each wheel cylinder.

[0072] Furthermore, when the second unit 202s determines that there is a system failure, the pressure source 203s, the shut-off valves 204b / 204c, and the pressure adjustment means 205b / 205c are all deactivated (de-energized), the shut-off valves 204b / 204c open, and communication is established between the connecting liquid path 209b and the connecting liquid path 211b, and between the connecting liquid path 209c and the connecting liquid path 211c.

[0073] Therefore, the pressure adjusted by the pressure adjusting means 205a / 205d of the first unit 202p is applied from the unit connection ports 213b / 213c of the second unit 202s to the connecting liquid paths 211b / 211c, 209b / 209c, and 210b / 210c.

[0074] Next, the processing performed by the sub-controller 230 will be described with reference to the flowchart of FIG. This process is performed by the sub-controllers 230p / 230s of the first unit 202p and the second unit 202s, respectively. The sub-controller 230 is configured to be independent of the main controller 206 and not be affected by failures, and is configured so that even if the main controller 206s of the second unit 202s fails and is unable to regulate pressure, the sub-controller 230s and each wheel pressure regulating means 265b / 265c can continue to function.

[0075] In step S501, it is determined whether the system is in a backup state. This is determined based on whether some kind of failure has occurred in the pressure regulation system of the first unit 202p or the second unit 202s, requesting backup control (flowchart in FIG. 2). If it is determined in step S501 that the system is not in a backup control state (i.e., the system is normal), the process proceeds to step S502.

[0076] In step S502, the normal control when the system is normal, as described above in

[0065] , is continued. That is, the wheel pressure adjusting means 265 is not operated, and the pressure adjusted by the pressure adjusting means 205 is transmitted to the wheel cylinder 218 as is.

[0077] If it is determined in step S501 that the backup control state is in effect, the process proceeds to step S503. In step S503, the hydraulic pressure target for each wheel is received. In this case, the hydraulic pressure target for each wheel based on the calculation result of the first unit 202p is received via communication means 1 or 2. Next, the process proceeds to step S504.

[0078] In step S504, the individual wheel pressure adjusting means 265 adjusts the respective pressures to the received individual wheel fluid pressures. As described above in

[0070] , the brake fluid supplied from the pressure source 203p of the normal system can be transmitted to the connecting fluid paths 210 of the first unit 202p and the second unit 202s, so all that remains is to distribute it to each wheel cylinder 218. To achieve this, the individual wheel pressure adjusting means 265 adjusts the pressure of the brake fluid supplied to the connecting fluid paths 210, and ultimately adjusts the fluid pressure of each wheel.

[0079] Each wheel pressure adjusting means 265 adjusts the pressure of the brake fluid supplied to the connecting fluid line 210 using a backup pressure increasing valve 260 and a backup pressure reducing valve 261, ultimately adjusting the fluid pressure of each wheel. In this case, no pressure sensors are used to detect the wheel cylinder pressure, but the amount of pressure increase or decrease is estimated, allowing for some degradation in accuracy. This estimation is performed by determining the characteristics of the differential pressure and flow rate generated at the solenoid valve in advance through experiments, etc., and then calculating the amount of brake fluid flowing into the caliper from the flow rate per unit time to estimate the pressure. Note that the differential pressure generated at the solenoid valve can be detected by the pressure sensor 255 of the normal system, which detects the pressure in the connecting fluid line 210, and the wheel cylinder pressure is an estimated value.

[0080] As described above, the hydraulic pressure in the connecting fluid passages 210a / 210d of the first unit 202p is adjusted by the wheel pressure adjusting means 265a / 265d, and is applied to the wheel cylinders 218a / 218d via the wheel cylinder ports 215a / 215d and the wheel cylinder piping 217a / 217d. The hydraulic pressure in the connecting fluid passages 210b / 210c of the second unit 202s is adjusted by the wheel pressure adjusting means 265b / 265c, and is applied to the wheel cylinders 218b / 218c via the wheel cylinder ports 215b / 215c and the wheel cylinder piping 217b / 217c.

[0081] As a result, even if the second unit 202s fails, the desired pressure is output to the wheel cylinder 218, just as when the system is normal, and the necessary braking force can be applied independently to each wheel FL to RR of the wheel cylinder 118.

[0082] Note that the above is an example of the case where the second unit 202s fails, but even if the first unit 102p fails, the operation itself is the same except that the first unit 202p and the second unit 202s are swapped in the processing of step S403 above.

[0083] Next, the effects of the second embodiment will be described. The hydraulic control system 201 of embodiment 2 includes two hydraulic units having the same configuration, namely, a first unit 202p and a second unit 202s, where the first unit 202p has an ECU 250p and the second unit 202s has an ECU 250s, and each hydraulic unit is provided with a shut-off valve 204 that is controlled only by a main controller 206 possessed by each hydraulic unit, and the upstream side (opposite the wheel cylinder) of the shut-off valve 204 provided in each hydraulic unit is connected by a unit connection pipe 219.

[0084] Therefore, since the two hydraulic units and the ECUs of each hydraulic unit are separated, even if a failure occurs in one of the hydraulic units or ECUs, the failure will not affect the other hydraulic unit or ECU.As a result, the discharge hydraulic pressure from the other hydraulic unit can be supplied to all wheels, ensuring braking force and resulting in greater reliability.

[0085] Furthermore, by providing each wheel pressure adjusting means 265 and sub-controller 230 within each hydraulic unit, it is possible to adjust the hydraulic pressure generated in the hydraulic unit individually at each wheel, making it possible to redundantly continue braking force control such as more advanced ABS and anti-skid functions, thereby achieving higher reliability as a braking device.

[0086] Furthermore, although the two units have the same configuration, they operate independently via shutoff valve 104 when the system is operating normally, so the first and second units can be configured to control only the hydraulic pressure control of the wheel cylinders connected to them, simplifying the consideration of control and the impact of failures. This also has the advantage of simplifying the system configuration.

[0087] [Embodiment 3] Fig. 6 is a configuration diagram of a hydraulic control system 401 according to a third embodiment. As with the first and second embodiments, the hydraulic control system 401 is a system intended for application primarily to autonomous vehicles of Level 4 or higher. A distinctive feature of this embodiment is that a backup wheel pressure adjusting means and a sub-controller are newly provided as a third unit separate from the first and second units.

[0088] The hydraulic control system 301 generates brake hydraulic pressure (wheel cylinder hydraulic pressure) in the wheel cylinder (braking force applying section) 418, thereby pressing the brake pads provided on each wheel FL to RR against the brake discs provided on the wheel side, thereby applying braking force to each wheel FL to RR.

[0089] The hydraulic control system 301 includes a first unit 302p, a second unit 302s, and a third unit 300. The first unit 302p and the second unit 302s are each a unit in which a pressure source 303, a shutoff valve 304, a pressure adjusting means 305, and a main controller 306 are integrally provided. The third unit 300 is a unit in which each wheel pressure adjusting means 320 and a sub-controller 330 are integrally provided. This differs from the first and second embodiments in that each wheel pressure adjusting means is separated into an independent hydraulic unit (the third unit 300). This allows for the configuration of a single sub-controller 330.

[0090] The first unit 302p and the second unit 302s each have a unit connection port 313, a suction port 314, and an output port 325.

[0091] The unit connection port 313 is connected to a unit connection pipe 319, and is connected to the shutoff valve 304 via a connection liquid path 311. The first unit 302p and the second unit 302s are connected by the unit connection pipe 319.

[0092] The suction port 314 is connected to a suction hose 316, and is connected to a pressure source 303 via a connecting fluid path 312. The first unit 302p and the second unit 302s are also connected to a reservoir tank 307 via the suction hose 316. The reservoir tank 307 is a brake fluid source that stores brake fluid, and is a low-pressure part that is open to atmospheric pressure.

[0093] The pressure source 303 and the pressure adjusting means 305 are connected via a connecting liquid path 308. The shutoff valve 304 and the pressure adjusting means 305 are connected via a connecting liquid path 309.

[0094] The output port 325 is connected to the pressure adjusting means 305 via a connecting liquid path 310. The first unit 302p and the second unit 302s are also connected from the output port 325 to an input port 326 of the third unit 300 via a relay pipe 327.

[0095] Each wheel pressure adjusting means 320 of the third unit 300 is connected to an input port 326 via a connecting fluid path 328. Also, each wheel pressure adjusting means 320 is connected to a wheel cylinder port 315 via a connecting fluid path 329.

[0096] Furthermore, each wheel pressure adjusting means 320 of the third unit 300 is connected to a return port 336 via a connecting fluid path 335. The return port 336 is connected to the reservoir tank 307 via a return pipe 337.

[0097] An output of first unit 302p is connected to left front wheel cylinder 318a and right rear wheel cylinder 318d, while an output of second unit 302s is connected to right front wheel cylinder 318b and left rear wheel cylinder 318c, in a so-called X (cross) piping configuration. Note that an H piping configuration may also be used, connecting the front wheels to first unit 302p and the rear wheels to second unit 302s.

[0098] Based on a command from a main controller 306, a pressure source 303 draws in brake fluid stored in a reservoir tank 307 and discharges the required flow rate to a pressure adjusting means 305.

[0099] Based on a command from the main controller 306, the pressure adjusting means 305 adjusts the pressure of the brake fluid supplied from the pressure source 303 and outputs the desired pressure to the output port 327 and to the shutoff valve 304. Here, within the pressure adjusting means 305, the connecting fluid path 309 and the connecting fluid path 310 are in communication (not shown).

[0100] Each wheel pressure adjusting means 320 is a backup pressure adjusting means (redundant each wheel pressure adjusting means) in case an abnormality occurs in the system and it becomes impossible to control the braking force (hydraulic pressure) of each wheel using only the pressure source 303, the shut-off valve 304, and the pressure adjusting means 305.

[0101] The shutoff valve 304 opens / closes based on a command from the main controller 306, thereby connecting / blocking communication between the connecting liquid path 309 and the connecting liquid path 311. The shutoff valve 304 has a so-called normally open structure, and is open when there is no command (electrical signal) from the main controller 306 and when it is not energized, i.e., the connecting liquid path 309 and the connecting liquid path 311 are in an open state (connected).

[0102] The main controllers 306p and 306s of the first unit 302p and the second unit 302s receive signals (target brake hydraulic pressure) from other ECUs via communication means. They also include applications for preventing unstable vehicle behavior, specifically ABS and anti-skid functions, and have the function of monitoring vehicle behavior, wheel speed, etc., and adjusting the braking force of each wheel as necessary. The main controller 306 controls the hydraulic pressure of each wheel by controlling the pressure source 303, shutoff valve 304, and pressure regulator 305 so that the hydraulic pressure achieves the desired braking force. The main controller 306 is composed of a microcontroller, an actuator driver, communication means, software, etc.

[0103] The sub-controller 330 of the third unit 300 controls each wheel pressure adjusting means 320 and is composed of a microcontroller, an actuator driver, a communication means, software, etc. Two power systems, power supply system 1 and power supply system 2, are connected to the sub-controller 330.

[0104] Wheel cylinders 318a and 318d of this embodiment correspond to the first wheel cylinders in the claims, wheel cylinders 318b and 318c of this embodiment correspond to the second wheel cylinders in the claims, first unit 302p and second unit 302s of this embodiment correspond to the first hydraulic unit and the second hydraulic unit in the claims, and unit connection pipe 319 of this embodiment corresponds to the connection pipe in the claims. Shutoff valves 304p and 304s of this embodiment correspond to the first shutoff valve and the second shutoff valve in the claims, and main controllers 306p and 306s of this embodiment correspond to the first control unit and the second control unit in the claims. A configuration in which pressure sources 303p and 303s and pressure adjustment units 305p and 305s of this embodiment are combined corresponds to the first pressure adjustment means and the second pressure adjustment means in the claims. Moreover, the pressure adjusting means 320 of this embodiment corresponds to the third pressure adjusting means and the fourth pressure adjusting means in the claims, and the sub-controller 330 corresponds to the third control section.

[0105] Next, the operation of the hydraulic pressure control system 301 of the third embodiment will be described. (Normal control when the system is normal) In the first unit 302p and the second unit 302s, the shutoff valve 304 closes in response to a command from the main controller 306, thereby shutting off the connection between the connecting liquid path 309 and the connecting liquid path 311. The main controller 306 also controls the pressure source 303 and the pressure adjusting means 305 to output a desired pressure to the wheel cylinder 318.

[0106] Furthermore, when main controller 306 detects unstable vehicle behavior and requires braking force application by the ABS or anti-skid function, it operates to apply the necessary pressure to wheel cylinders 318 to each of wheels FL-RR. In this case, the control intervention decision and braking force operation amount calculation in the application software for the ABS or anti-skid function can be performed by either first hydraulic pressure unit 302p or second hydraulic pressure unit 302s. For example, if first hydraulic pressure unit 302p mainly performs the control calculation, the hydraulic pressure command value for wheel cylinders 318b / 318c connected to second hydraulic pressure unit 302s can be transmitted and controlled using communication means. Conversely, second hydraulic pressure unit 302s may mainly perform the calculation and transmit the hydraulic pressure command value to first hydraulic pressure unit 302p. Alternatively, first hydraulic pressure unit 203p and second hydraulic pressure unit 203s may independently determine control intervention and operation. This combination is possible because two hydraulic pressure units with the same function are configured.

[0107] (Backup control in case of system failure) Here, as an example, the processing performed by the main controller 306 when the pressure adjusting means of the second unit 302s fails (breaks down) will be described with reference to the flowchart in Fig. 2. In step S401, it is determined whether the second unit 302s is capable of hydraulic pressure control. This determination is made by the pressure source 303, the shutoff valve 304, the pressure adjusting means 305, and failure detection logic (not shown) of the main controller 306, which are incorporated in the main controller 306. If it is determined that hydraulic pressure control is possible, the process proceeds to step S402, and if it is determined that hydraulic pressure control is not possible, i.e., a system failure, the process proceeds to step S403.

[0108] In step S402, the normal control when the system is normal, as described above in

[0105] , is continued.

[0109] In step S403, the process shifts to backup control, and the process proceeds to step S404. As a result, the shutoff valve 304p of the first unit 302p is opened. This operation connects the connecting liquid path 309p and the connecting liquid path 311p, and the pressure regulated by the pressure regulating means 305p is applied to the unit connecting port 313s of the second unit 302s via the output ports 325a / 325d and the unit connecting pipe 319.

[0110] In step S404, the sub-controller 330 of the third unit 300 is notified that the system has transitioned to backup control, and the target hydraulic pressures for each wheel are transmitted via the communication means 1 or 2. Each wheel pressure adjusting means 320 of the third unit 300 recognizes that backup control is in effect and controls the hydraulic pressure of each wheel cylinder.

[0111] Furthermore, when the second unit 302s determines that there is a system failure, the pressure source 303s, the shutoff valve 304s, and the pressure adjusting means 305s are all deactivated (de-energized), the shutoff valve 304s opens, and the connecting liquid path 309s and the connecting liquid path 311s communicate with each other. In other words, when the main controllers 306p and 306s detect a failure of either the first unit 302p or the second unit 302s, they open the shutoff valves 304p and 304s, respectively.

[0112] Therefore, the pressure regulated by the pressure regulating means 305p of the first unit 302p not only flows through the connecting liquid path 310a / 310d, but also enters the unit connection port 313s of the second unit 302s via the connecting liquid path 311p, the unit connection port 313p, and the connecting liquid path 319, and is applied to the connecting liquid path 311s, the connecting liquid path 309s, the pressure regulating means 305s (inactive state), and the connecting liquid paths 310b / 310c.

[0113] Next, the processing performed by the sub-controller 330 will be described with reference to the flowchart of FIG. This process is performed by the sub-controller 330 in the third unit 300. The sub-controller 330 is configured to be independent of the main controllers 306 of the first unit 302p and the second unit 302s and is not affected by failures, and is configured so that even if the main controller 306s of the second unit 302s fails and is unable to regulate pressure, the sub-controller 330 of the third unit 300 and each wheel pressure regulating means 320 can continue to function.

[0114] In step S501, it is determined whether the system is in a backup state. This is determined based on whether some kind of failure has occurred in the pressure regulation system of the first unit 302p or the second unit 302s, requesting backup control (flowchart in FIG. 2). In step S501, if it is determined that the system is not in a backup control state (i.e., the system is normal), the process proceeds to step S502.

[0115] In step S502, the normal control when the system is normal, as described in

[0105] above, is continued. That is, the wheel pressure adjusting means 320 is not operated, and the pressure adjusted by the pressure adjusting means 305 is transmitted to the wheel cylinder 318 as is.

[0116] If it is determined in step S501 that the backup control state is in effect, the process proceeds to step S503. In step S503, the hydraulic pressure target for each wheel is received. In this case, the hydraulic pressure target for each wheel based on the calculation result of the first unit 302p is received via communication means. The hydraulic pressure target for the second unit 302s in which a failure has occurred is ignored even if it is output. Next, the process proceeds to step S504.

[0117] In step S504, each wheel pressure adjusting means 320 adjusts the pressure to the received wheel fluid pressure. As described above in

[0112] , the brake fluid supplied from the pressure source 303p of the normal system can be transmitted to the connecting fluid passages 310 of the first unit 302p and the second unit 302s, so all that remains is to distribute it to each wheel cylinder 318. To achieve this, each wheel pressure adjusting means 320 adjusts the pressure of the brake fluid supplied to the connecting fluid passages 310, and ultimately adjusts the fluid pressure of each wheel. At this time, any brake fluid that becomes surplus in the wheel cylinder as a result of the pressure adjustment is returned to the reservoir tank via the return pipe 337.

[0118] As described above, the hydraulic pressure in connecting fluid passages 310a / 310d of first unit 302p is further adjusted by each wheel pressure adjusting means 320 and is applied to wheel cylinders 318a / 318d via connecting fluid passages 329a / 329d, wheel cylinder ports 315a / 315d, and wheel cylinder piping 317a / 317d. The hydraulic pressure in connecting fluid passages 310b / 310c of second unit 302s is further adjusted by each wheel pressure adjusting means 320 and is applied to wheel cylinders 318b / 318c via connecting fluid passages 329b / 329c, wheel cylinder ports 315b / 315c, and wheel cylinder piping 317b / 317c.

[0119] As a result, even if the second unit 302s fails, the desired pressure is output to the wheel cylinder 318, just as when the system is normal, and the required braking force can be applied independently to each of the wheels FL to RR by the wheel cylinder 318.

[0120] Note that the above is an example of the case where the second unit 302s fails, but even if the first unit 302p fails, the operation itself is the same, except that the first unit 302p and the second unit 302s are swapped in the processing of step S401 above.

[0121] Next, the effects of the third embodiment will be described. The hydraulic control system 301 of embodiment 3 includes two hydraulic units having the same configuration, a first unit 302p and a second unit 302s, and a third unit 300. The first unit 302p has a main controller 306p, and the second unit 302s has a main controller 306s. Each hydraulic unit is provided with a shut-off valve 304 that is controlled only by the main controller 306 of each hydraulic unit. The upstream side (opposite the wheel cylinder) of the shut-off valve 304 provided in each unit is connected by a unit connection pipe 319, and the unit connection pipe 319 is provided.

[0122] Therefore, since these hydraulic units and the ECUs possessed by each hydraulic unit are separated, even if a failure occurs in the hydraulic unit / ECU of either the first unit 302p or the second unit 302s, the failure will not affect the other hydraulic unit / ECU, and the discharge hydraulic pressure from the other hydraulic unit can be supplied to all wheels, ensuring braking force and thereby achieving higher reliability.

[0123] Furthermore, by providing each wheel pressure adjusting means 320, it is possible to adjust the hydraulic pressure generated in the hydraulic unit individually for each wheel, making it possible to redundantly continue braking force control such as more advanced ABS and anti-skid functions, thereby achieving higher reliability as a braking device.

[0124] Furthermore, although the first and second units have the same configuration, they operate independently via shutoff valve 304 when the system is operating normally, and the first and second units can be configured to control only the hydraulic pressure control of the wheel cylinders connected to them, which simplifies the consideration of control and the impact of failures. This also has the advantage of simplifying the system configuration.

[0125] In this configuration, compared to the first and second embodiments, each wheel pressure adjusting means 320 is separated into the third unit 300, thereby reducing the number of sub-controllers 330 by one. However, since the number of pipes increases as the relay pipe 327 and the return pipe 337, it is preferable to select the most suitable one in consideration of the vehicle layout, etc.

[0126] [Embodiment 4] 7 is a configuration diagram of a hydraulic control system 601 according to embodiment 4. Similar to embodiments 1, 2, and 3, the hydraulic control system 401 is a system intended for application mainly to autonomous vehicles of Level 4 or higher. This embodiment also uses more specific hydraulic circuit components than embodiment 3.

[0127] The hydraulic control system 601 generates brake hydraulic pressure (wheel cylinder hydraulic pressure) in the wheel cylinder (braking force applying section) 618, thereby pressing the brake pads provided on each wheel FL to RR against the brake discs provided on the wheel side, thereby applying braking force to each wheel FL to RR.

[0128] The hydraulic control system 601 includes a first unit 602p and a second unit 602s. Each of the first unit 602p and the second unit 602s is a unit in which a pressure source 603, a shutoff valve 604, a pressure adjusting means 605, and an ECU 650 are integrally provided. The third unit 600 is a unit in which each wheel pressure adjusting means 620 and an ECU 690 are integrally provided.

[0129] The first unit 602p and the second unit 602s each have a unit connection port 613, a suction port 614, and an output port 655.

[0130] The unit connection port 613 is connected to a unit connection pipe 619, and is connected to the shutoff valve 604 via a connection liquid path 611. The first unit 602p and the second unit 602s are connected to each other via the unit connection pipe 619.

[0131] The suction port 614 is connected to a suction hose 616, and is connected to a pressure source 603 via a connecting fluid path 612. The first unit 602p and the second unit 602s are connected to a reservoir tank 607 via the suction hose 616. In detail, the reservoir tank 607 is divided into three sections, with a primary fluid chamber 667P connected to the first unit 602p and a secondary fluid chamber 667S connected to the second unit 602s. The return fluid chamber 667R is connected to the third unit 600. The reservoir tank 607 is a brake fluid source that stores brake fluid and is a low-pressure section that is open to atmospheric pressure.

[0132] Output port 655 is connected to pressure regulating means 605 via connecting fluid path 610. Furthermore, first unit 602p and second unit 602s are connected to input port 657 of the third unit via output port 655 and relay piping 656. This path ultimately adopts a so-called X (cross) piping configuration, in which the primary system of first unit 602p is connected to left front wheel cylinder 618a and right rear wheel cylinder 618d, while the secondary system of second unit 602s is connected to right front wheel cylinder 618b and left rear wheel cylinder 618c. Note that H piping may also be used, connecting the front wheels to the primary system and the rear wheels to the secondary system.

[0133] The pressure source 603 and the pressure adjusting means 605 are connected via a connecting liquid path 608. The shutoff valve 604 and the pressure adjusting means 605 are connected via a connecting liquid path 609.

[0134] The pressure source 603 is composed of a pump 623 and a motor 633 that drives the pump. Based on a command from the controller 606, the rotation of the motor 633 is controlled to suck in brake fluid stored in the reservoir tank 607 and discharge the required flow rate to the pressure adjusting means 605.

[0135] The pressure adjusting means 605 is composed of a pressure increase control valve 625, a pressure decrease control valve 635, a communication valve 645, a pressure sensor 685, and a pressure sensor 666, and adjusts the pressure of the brake fluid supplied from the pressure source 603 based on a command from the controller 606. That is, the pressure detected by the pressure sensors 685 / 665 is fed back, and when increasing the pressure, the pressure increase control valve 625 is opened and the pressure decrease control valve 635 is closed, and when decreasing the pressure, the pressure increase control valve 625 is closed and the pressure decrease control valve 635 is opened, thereby obtaining the desired pressure. The adjusted pressure is output to the output port 655 and the shutoff valve 204 side by opening the communication valve 645. One pressure increase control valve 625, one pressure decrease control valve 635, one communication valve 645, and one pressure sensor 685 are assigned to each output port 655. For example, pressure increase control valve 625a, pressure decrease control valve 635a, communication valve 645a, and pressure sensor 685a are assigned to output port 655a connected to FL wheel cylinder 618a. Therefore, the brake fluid supplied from pressure source 603 can be independently adjusted to a desired pressure in the wheel cylinder of each wheel. Therefore, hydraulic pressure control system 601 can independently adjust the pressure in all four wheels.

[0136] The shutoff valve 604 opens / closes based on a command from the controller 606, and connects / disconnects the connecting liquid path 609 and the connecting liquid path 611. The shutoff valve 604 has a so-called normally open structure, and is open when there is no command (electrical signal) from the controller 606, i.e., when it is not energized, the shutoff valve 604 is open, i.e., the connecting liquid path 609 and the connecting liquid path 611 are in an open state.

[0137] The ECU 650 is an electronic control unit (ECU) that controls the first unit 602p and the second unit 602s, and includes a main controller 606 therein.

[0138] The main controller 606 receives signals (target brake hydraulic pressure) from other ECUs via communication means. It also includes applications for preventing unstable vehicle behavior, specifically ABS and anti-skid functions, and has the function of monitoring vehicle behavior, wheel speed, etc., and adjusting the braking force of each wheel as necessary. It controls the hydraulic pressure of each wheel by controlling the pressure source 603, shutoff valve 604, and pressure regulator 605 so that the hydraulic pressure achieves the desired braking force.

[0139] A connecting fluid passage 672 is formed from input port 657 of third unit 600 to wheel cylinder port 615, and a backup pressure increase valve 670 is provided on connecting fluid passage 672. An oil passage branches on connecting fluid passage 672 between backup pressure increase valve 670 and wheel cylinder port 615, and a backup pressure reduction valve 671 is provided on an oil passage different from that of wheel cylinder port 615. Backup pressure reduction valve 671 is connected to a return port 659 via a return connecting fluid passage 658. Return port 659 is connected to a return fluid chamber 667R of reservoir tank 607 via return piping 660.

[0140] Each wheel pressure adjusting means 620 refers to a portion configured from a backup pressure increasing valve 670, a backup pressure reducing valve 671, a connecting fluid path 672, and a return connecting fluid path 658. Based on a command from a controller 630 of an ECU 690, the backup pressure increasing valve 670 can control the amount of pressure increase by restricting the flow rate generated in an input port 657 to a wheel cylinder 618 during backup control. The backup pressure reducing valve 671 can control the amount of pressure reduction in the wheel cylinder 618 by causing the pressure generated in the wheel cylinder to flow out to a return connecting fluid path 658. Therefore, as long as there is a means for flowing brake fluid into the input port 657, the pressure adjustment of each wheel can be continued.

[0141] The controller 630 controls each wheel pressure adjusting means 620 and is composed of a microcontroller, an actuator driver, a communication means, software, etc. At this time, two power supply connections are made. The functions of the controller 606 and the controller 630 are independent, and they are configured so that they are not affected by each other's failures.

[0142] Wheel cylinders 618a and 618d of this embodiment correspond to the first wheel cylinders in the claims, wheel cylinders 618b and 618c of this embodiment correspond to the second wheel cylinders in the claims, first unit 602p and second unit 602s of this embodiment correspond to the first hydraulic unit and the second hydraulic unit in the claims, and unit connection pipe 619 of this embodiment corresponds to the connection pipe in the claims. Shutoff valves 604p and 604s of this embodiment correspond to the first shutoff valve and the second shutoff valve in the claims, and controllers 606p and 606s of this embodiment correspond to the first control unit and the second control unit in the claims. A configuration in which pressure sources 603p and 603s and pressure adjustment units 605p and 605s of this embodiment are combined corresponds to the first pressure adjustment means and the second pressure adjustment means in the claims. Moreover, the wheel pressure adjusting means 620 of this embodiment corresponds to the third pressure adjusting means and the fourth pressure adjusting means in the claims, and the controller 630 corresponds to the third control section.

[0143] Next, the operation of the hydraulic pressure control system 601 of the fourth embodiment will be described. (Normal control when the system is normal) In the first unit 602p and the second unit 602s, the shutoff valve 604 closes in response to a command from the controller 606 in the ECU 650, blocking communication between the connecting fluid path 609 and the connecting fluid path 611. The ECU 650 also controls the pressure source 603 and the pressure adjusting means 605 to output the desired pressure to the wheel cylinder 618. At this time, the third unit 600 is in a standby state where it does nothing, and the pressure output by the pressure adjusting means 605 is generated directly in the wheel cylinder 618.

[0144] When controller 606 detects unstable vehicle behavior and braking force application is required by ABS or anti-skid function, pressure regulating means 605 supplies the necessary pressure to wheel cylinder 618 to apply the necessary braking force to each of wheels FL-RR. In this case, in the application of ABS or anti-skid function, control intervention determination and braking force operation amount calculation can be performed by at least one of first hydraulic pressure unit 602p and second hydraulic pressure unit 602s. For example, when controller 606p of first hydraulic pressure unit 602p mainly performs control calculation, hydraulic pressure command values ​​for wheel cylinders 618b / 618c connected to second hydraulic pressure unit 602s are transmitted to controller 606s via communication means, and controller 606s controls the hydraulic pressures in accordance with the received command. Conversely, controller 606s of second hydraulic pressure unit 602s may mainly perform calculations and transmit hydraulic pressure command values ​​to first hydraulic pressure unit 602p. Alternatively, the controllers of the first hydraulic pressure unit 602p and the second hydraulic pressure unit 602s may each independently determine control intervention and operation. This type of combination is possible because two units with exactly the same functions are prepared as redundant systems.

[0145] (Backup control in case of system failure) Here, as an example, a process performed by the controller 606p of the ECU 650 when the pressure regulation function of the second unit 602s fails will be described with reference to the flowchart of FIG.

[0146] In step S401, it is determined whether the second unit 602s is capable of hydraulic pressure control. This determination is made by the pressure source 603, the shutoff valve 604, the pressure adjusting means 605, and a failure detection logic (not shown) of the ECU 650, which are incorporated in the ECU 650. If it is determined that hydraulic pressure control is possible, the process proceeds to step S402, and if it is determined that hydraulic pressure control is not possible, i.e., a system failure, the process proceeds to step S403.

[0147] In step S402, normal control when the system is normal, as described above in

[0143] , is continued.

[0148] In step S403, the system transitions to backup control. That is, the shutoff valves 604a / 604d of the first unit 602p are opened. This operation establishes communication between the connecting liquid path 609a and the connecting liquid path 611a, and between the connecting liquid path 609d and the connecting liquid path 611d, and the pressure regulated by the pressure regulating means 605a / 605d passes through the output ports 655a / 655d and the unit connection pipe 619 and is applied to the unit connection ports 613b / 613c of the second unit 602s.

[0149] In step S404, the controller 630 of the third unit 600 is notified that the system has transitioned to backup control, and the target hydraulic pressures for each wheel are transmitted via communication means 1 or 2. Each wheel pressure adjusting means 620 recognizes that backup control is in effect and controls the hydraulic pressure of each wheel cylinder.

[0150] Furthermore, when the second unit 602s determines that there is a system failure, the pressure source 603s, the shut-off valves 604b / 604c, and the pressure adjustment means 605b / 605c are all deactivated (de-energized), the shut-off valves 604b / 604c open, and communication is established between the connecting liquid path 609b and the connecting liquid path 611b, and between the connecting liquid path 609c and the connecting liquid path 611c.

[0151] Therefore, the pressure adjusted by the pressure adjusting means 605a / 605d of the first unit 602p is applied from the unit connection ports 613b / 613c of the second unit 602s to the connecting liquid paths 611b / 611c, connecting liquid paths 609b / 609c, connecting liquid paths 610b / 610c, and output ports 655c / 655d.

[0152] Next, the processing performed by the controller 630 of the third unit 600 will be described with reference to the flowchart of FIG. This process is performed by the controller 630 of the third unit 600. The controller 630 is configured to be independent of the controller 606 and not be affected by failures, and is configured so that even if the controller 606s of the second unit 602s fails and is unable to regulate pressure, the controller 630 and each wheel pressure regulating means 620 can continue to function.

[0153] In step S501, it is determined whether the system is in a backup state. This is determined based on whether some kind of failure has occurred in the pressure regulation system of the first unit 602p or the second unit 602s, requesting backup control (flowchart in FIG. 2). In step S501, if it is determined that the system is not in a backup control state (i.e., the system is normal), the process proceeds to step S502.

[0154] In step S502, the normal control when the system is normal, as described above in

[0143] , is continued. That is, each wheel pressure adjusting means 620 is not operated, and the pressure adjusted by the pressure adjusting means 605 is transmitted to the wheel cylinder 618 as is.

[0155] If it is determined in step S501 that the backup control state is in effect, the process proceeds to step S503. In step S503, the hydraulic pressure target for each wheel is received. In this case, the hydraulic pressure target for each wheel based on the calculation result of the first unit 602p is received via communication means 1 or 2. Next, the process proceeds to step S504.

[0156] In step S504, each wheel pressure adjusting means 620 adjusts the pressure to the received wheel fluid pressure. As described above in

[0148] , the brake fluid supplied from the pressure source 603p of the normal system can be transmitted to the connecting fluid passages 610 of the first unit 602p and the second unit 602s, so all that remains is to distribute it to each wheel cylinder 618. Therefore, each wheel pressure adjusting means 620 adjusts the pressure of the brake fluid supplied to the connecting fluid passages 610, and ultimately adjusts the fluid pressure of each wheel.

[0157] Each wheel pressure adjusting means 620 adjusts the pressure of the brake fluid supplied to the connecting fluid line 610 using a backup pressure increasing valve 670 and a backup pressure reducing valve 671, ultimately adjusting the fluid pressure of each wheel. In this case, no pressure sensors are used to detect the wheel cylinder pressure, but the amount of pressure increase or decrease is estimated, allowing for some degradation in accuracy. This estimation is performed by determining the characteristics of the differential pressure and flow rate generated at the solenoid valve in advance through experiments, etc., and then calculating the amount of brake fluid flowing into the caliper from the flow rate per unit time to estimate the pressure. Note that the pressure difference generated at the solenoid valve, the pressure of the connecting fluid line 610, can be detected by a pressure sensor 685 in the normal system, and the wheel cylinder pressure is an estimated value.

[0158] As described above, the hydraulic pressure in connecting fluid passages 610a / 610d of first unit 602p is adjusted by wheel pressure adjusting means 620a / 620d, and is applied to wheel cylinders 618a / 618d via wheel cylinder ports 615a / 615d and wheel cylinder piping 617a / 617d. The hydraulic pressure in connecting fluid passages 610b / 610c of second unit 602s is adjusted by wheel pressure adjusting means 620b / 620c, and is applied to wheel cylinders 618b / 618c via wheel cylinder ports 615b / 615c and wheel cylinder piping 617b / 617c.

[0159] As a result, even if the second unit 602s fails, the desired pressure is output to the wheel cylinder 618, just as when the system is normal, and the required braking force can be applied independently to each wheel FL to RR of the wheel cylinder 618.

[0160] Note that the above is an example of when the second unit 602s fails, but even if the first unit 602p fails, the operation itself is the same, except that the first unit 602p and the second unit 602s are swapped in the processing of step S403 above.

[0161] Next, the effects of the fourth embodiment will be described. The hydraulic control system 601 of embodiment 4 includes two hydraulic units having the same configuration, namely, a first unit 602p, a second unit 602s, and a third unit 600, wherein the first unit 602p has a controller 606p and the second unit 602s has a controller 606s, and each hydraulic unit is provided with a shut-off valve 604 controlled only by the controller 606 of each unit, and the upstream side (opposite the wheel cylinder) of the shut-off valve 304 provided in each hydraulic unit is connected by a unit connection pipe 619, and the unit connection pipe 619 is provided.

[0162] Therefore, since these hydraulic units and the ECUs possessed by each hydraulic unit are separated, even if a failure occurs in the hydraulic unit / ECU of either the first unit 602p or the second unit 602s, the failure will not affect the other hydraulic unit / ECU, and the discharge hydraulic pressure from the other hydraulic unit can be supplied to all wheels, making it possible to ensure braking force, thereby achieving higher reliability.

[0163] Furthermore, by providing the third unit 600 with wheel pressure adjusting means 620 and controller 630, it is possible to adjust the hydraulic pressure generated in the first and second units for each wheel individually, making it possible to redundantly continue braking force control such as more advanced ABS and anti-skid functions, thereby achieving higher reliability as a braking device.

[0164] Furthermore, although the first and second units have the same configuration, they operate independently via shutoff valve 604 when the system is operating normally, so the first and second units can be configured to control only the hydraulic pressure control of the wheel cylinders connected to them, simplifying the consideration of control and the impact of failures. This also simplifies the system configuration.

[0165] In this configuration, the number of controllers is reduced by one by separating each wheel pressure adjusting means 620 into the third unit 600 compared to the first and second embodiments. However, since the number of relay pipes 656 and return pipes 660 increases, it is preferable to select the most suitable one in consideration of the vehicle layout, etc.

[0166] [Embodiment 5] 8 is a configuration diagram of a hydraulic control system 701 according to embodiment 5. As with embodiments 1 to 4, hydraulic control system 701 is a system intended for application mainly to autonomous vehicles of Level 4 or higher. This embodiment has many of the same configurations as embodiment 1, and only the differences will be described.

[0167] The hydraulic pressure control system 101 of the first embodiment includes a first unit 102p and a second unit 102s, each of which is an integral unit that includes a pressure source 103, a shutoff valve 104, a pressure adjusting means 105, each wheel pressure adjusting means 120, a main controller 106, and a sub-controller 130. However, the hydraulic pressure control system 701 of the fifth embodiment has a configuration in which the sub-controller 130p is removed from the first unit 702p. The other configurations and functions are the same as those of the first embodiment. Note that it is also possible to remove the sub-controller of the second unit and leave the sub-controller of the first unit.

[0168] Instead, an electromagnetic valve drive signal line 780 is provided from the second unit 702s and connected to each wheel pressure adjusting means 720p of the first unit 702p.

[0169] That is, the sub-controller 730s of the second unit 702s is in charge of controlling the wheel pressure adjusting means 720p of the first unit 702p and the wheel pressure adjusting means 720s of the second unit 702s.

[0170] The sub-controller 730s is composed of a microcontroller, an actuator driver, communication means, software, etc. At this time, two power supply connections are made. The functions of the sub-controller 730s and the main controller 706s are independent, and are configured so that they are not affected by each other's failures. Therefore, when a failure occurs in the system and operation of each wheel pressure regulating means 720 is required, not only each wheel pressure regulating means 720s of the second unit 702s but also each wheel pressure regulating means 720p of the first unit 702p can be controlled.

[0171] Wheel cylinders 718a and 718d of this embodiment correspond to the first wheel cylinders in the claims, wheel cylinders 718b and 718c of this embodiment correspond to the second wheel cylinders in the claims, first unit 702p and second unit 702s of this embodiment correspond to the first hydraulic unit and the second hydraulic unit in the claims, and unit connection piping 719 of this embodiment corresponds to the connection piping in the claims. Shutoff valves 704p and 704s of this embodiment correspond to the first shutoff valve and the second shutoff valve in the claims, and controllers 706p and 706s of this embodiment correspond to the first control unit and the second control unit in the claims. A configuration in which pressure sources 703p and 703s and pressure regulating means 705p and 705s of this embodiment are combined corresponds to the first pressure regulating means and the second pressure regulating means in the claims. Moreover, the wheel pressure adjusting means 720p, 720s in this embodiment correspond to the third pressure adjusting means and the fourth pressure adjusting means in the claims, and the sub-controller 730s corresponds to the third control section.

[0172] Next, the operation of the hydraulic pressure control system 701 of the fifth embodiment will be described. (Normal control when the system is normal) The normal operation is the same as in the first embodiment because the wheel pressure adjusting means are not in operation, and therefore a description thereof will be omitted here.

[0173] (Backup control in case of system failure) Here, the process performed by the main controller 706p when the pressure adjusting means of the second unit 702s fails (breaks down) will be described with reference to the flowchart of FIG. In step S401, it is determined whether the second unit 702s is capable of hydraulic pressure control. This determination is made by the pressure source 703, the shutoff valve 704, the pressure adjusting means 705, and a fault detection logic (not shown) of the main controller 706, which are incorporated in the main controller 706. If it is determined that hydraulic pressure control is possible, the process proceeds to step S402, and if it is determined that hydraulic pressure control is not possible, i.e., a system failure, the process proceeds to step S403.

[0174] In step S402, normal control when the system is normal continues.

[0175] In step S403, the process shifts to backup control, and the process proceeds to step S404. As a result, the shutoff valve 704p of the first unit 702p is opened. This operation connects the connecting fluid path 709p and the connecting fluid path 711p, and the pressure regulated by the pressure regulating means 705p is applied to the unit connection port 713s of the second unit 702s via the unit connection pipe 719 together with the wheel cylinders 718a / 718d.

[0176] In step S404, the system notifies the sub-controller 730s that the system has transitioned to backup control, and transmits the target hydraulic pressure for each wheel via communication means 1 or 2. Recognizing that the system is in backup control, each wheel pressure adjusting means 720 controls the hydraulic pressure in each wheel cylinder.

[0177] Furthermore, when the second unit 702s determines that there is a system failure, the pressure source 703s, the shutoff valve 704s, and the pressure adjusting means 705s are all deactivated (de-energized), the shutoff valve 704s opens, and the connecting liquid path 709s and the connecting liquid path 711s communicate with each other. In other words, when the main controllers 706p and 706s detect a failure of either the first unit 702p or the second unit 702s, they open the shutoff valves 704p and 704s, respectively.

[0178] Therefore, the pressure adjusted by the pressure adjustment means 705p of the first unit 702p flows not only through the connecting liquid path 710a / 710d, but also through the connecting liquid path 711p, the unit connection port 713p, and the unit connection piping 719 to the unit connection port 713s of the second unit 702s, and is applied to the connecting liquid path 711s, the connecting liquid path 709s, the pressure adjustment means 705s, and the connecting liquid paths 710b / 710c.

[0179] Next, the processing performed by the sub-controller 730s will be described with reference to the flowchart of FIG. This process is performed by the sub-controller 730s of the second unit 702s. The sub-controller 730s is configured to be independent of the main controllers 706p / 706s and not be affected by failures, so that even if the main controller 706s of the second unit 702s fails and is unable to regulate pressure, the sub-controller 730s and each wheel pressure regulating means 720p / 720s are configured to continue to function.

[0180] In step S501, it is determined whether the system is in a backup state. This is determined based on whether some kind of failure has occurred in the pressure regulation system of the first unit 702p or the second unit 702s, requesting backup control (flowchart in FIG. 2). In step S501, if it is determined that the system is not in a backup control state (i.e., the system is normal), the process proceeds to step S502.

[0181] In step S502, normal control is continued under normal system conditions. That is, each wheel pressure adjusting means 720 is not operated, and the pressure adjusted by pressure adjusting means 105 is transmitted to wheel cylinder 718 as is.

[0182] If it is determined in step S501 that the backup control state is in effect, the process proceeds to step S503. In step S503, the hydraulic pressure target for each wheel is received. In this case, the hydraulic pressure target for each wheel based on the calculation result of the first unit 702p is received via the communication means. Next, the process proceeds to step S504.

[0183] In step S504, each wheel pressure regulating means 720 controls its pressure to the received wheel fluid pressure. As described above in

[0175] , the brake fluid supplied from the pressure source 703p of the normal system can be transmitted to the connecting fluid paths 710 of the first unit 702p and the second unit 702s, so all that remains is to distribute it to each wheel cylinder 718. To achieve this, each wheel pressure regulating means 720 regulates the pressure of the brake fluid supplied to the connecting fluid paths 710, and ultimately regulates the fluid pressure of each wheel. At this time, a control signal is transmitted to each wheel pressure regulating means 720p of the first unit 702p via the solenoid valve drive signal line 780, and the solenoid valve of each wheel pressure regulating means 720p is driven, thereby enabling control to the desired brake fluid pressure.

[0184] As described above, the hydraulic pressure in the connecting fluid passages 710a / 710d of the first unit 702p is further adjusted by each wheel pressure adjusting means 720p and is applied to wheel cylinders 718a / 718d via connecting fluid passages 721a / 721d, wheel cylinder ports 715a / 715d, and wheel cylinder piping 717a / 717d. The hydraulic pressure in the connecting fluid passages 710b / 710c of the second unit 102s is further adjusted by each wheel pressure adjusting means 120s and is applied to wheel cylinders 718b / 718c via connecting fluid passages 721b / 721c, wheel cylinder ports 715b / 715c, and wheel cylinder piping 717b / 717c.

[0185] As a result, even if the second unit 702s fails, the desired pressure is output to the wheel cylinder 718, just as when the system is normal, and the required braking force can be applied independently to each wheel FL to RR of the wheel cylinder 718.

[0186] Note that the above is an example of when the second unit 702s fails, but even if the first unit 702p fails, the operation itself is the same, except that the first unit 702p and the second unit 702s are swapped in the processing of step S403 above.

[0187] Next, the effects of the fifth embodiment will be described. The hydraulic control system 701 of embodiment 5 has two hydraulic units, namely, a first unit 702p and a second unit 702s, the first unit 702p having a main controller 706p, and the second unit 702s having a main controller 706s, and each hydraulic unit is provided with a shut-off valve 704 that is controlled only by the main controller 706 of each hydraulic unit, and the upstream side (opposite the wheel cylinder) of the shut-off valve 704 provided in each hydraulic unit is connected by a unit connection pipe 719.

[0188] Therefore, since the two hydraulic units and the ECUs of each hydraulic unit are separated, even if a failure occurs in one of the hydraulic units or ECUs, the failure will not affect the other hydraulic unit or ECU. As a result, the hydraulic pressure discharged from the other hydraulic unit can be supplied to all wheels, ensuring braking force.

[0189] Furthermore, each hydraulic unit is provided with a wheel pressure adjusting means 720, and one of the hydraulic units is provided with a sub-controller 730 for controlling it. For hydraulic units that do not have a sub-controller 730, a solenoid valve drive signal line 780 is provided to each wheel pressure adjusting means 720 to transmit a control signal and drive it. This makes it possible to adjust the hydraulic pressure generated in the hydraulic unit individually for each wheel, making it possible to redundantly continue braking force control such as more advanced ABS and anti-skid functions, and achieving higher reliability as a brake device.

[0190] Furthermore, although the two units have the same configuration except for the presence or absence of the sub-controller, when the system is normal they operate independently via shutoff valve 704, so first / second unit 702 can be configured for control with consideration given only to the hydraulic control of the wheel cylinders connected to it, simplifying the consideration of the effects of control and failures. This also has the advantage of simplifying the system configuration.

[0191] By eliminating the sub-controller, it is possible to reduce the microcontroller of the hydraulic control system 701 and the associated power supply circuit and communication functions, and to build an efficient system by centralizing the control of each wheel pressure adjusting means 720. Furthermore, this change can be realized by whether or not related elements are mounted on the ECU board, so it can be handled with a simple design change.

[0192] Other Embodiments The above describes an embodiment for carrying out the present invention, but the specific configuration of the present invention is not limited to the configuration of the embodiment, and design changes and the like that do not deviate from the gist of the invention are also included in the present invention.

[0193] For example, in the embodiment, the pressure source is described as being composed of a pump and a motor that drives the pump, but the pump may be either a plunger pump or a rotary pump, or may be an electric piston operated by an electric motor.

[0194] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various design modifications can be made without departing from the spirit of the present invention as defined in the claims. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations. [Explanation of symbols]

[0195] 101 hydraulic control system (brake device), 102p first unit (first hydraulic unit), 102s second unit (second hydraulic unit), 103p pressure source (first pressure feeding section), 103s pressure source (second pressure feeding section), 104p shut-off valve (first shut-off valve), 104s shut-off valve (second shut-off valve), 105p pressure regulating means (first pressure regulating section), 105s pressure regulating means (second pressure regulating section), 106p ECU (first control section), 106s ECU (second control section), 107 reservoir tank, 118a, 118d wheel cylinder (first wheel cylinder), 118b, 118c wheel cylinder (second wheel cylinder), 119 unit connecting piping (connecting piping), 120p each wheel pressure regulating means (third pressure regulating section), 120s Each wheel pressure adjusting means (fourth pressure adjusting unit), 130 sub-controller (third control unit), 130p sub-controller (fourth control unit), 130s sub-controller (fifth control unit)

Claims

1. A brake device mounted on a vehicle, a first hydraulic unit that supplies brake fluid to a plurality of first wheel cylinders; a second hydraulic unit that supplies brake fluid to the second wheel cylinders; a connecting pipe that connects the first hydraulic pressure unit and the second hydraulic pressure unit and allows the brake fluid to flow, The first hydraulic unit is a first shutoff valve that shuts off the flow of the brake fluid between the connecting pipe and the first shutoff valve; a first pressure adjusting unit that adjusts the pressure of the brake fluid supplied to the plurality of first wheel cylinders; a first control unit that controls opening and closing of the first shutoff valve and the first pressure adjusting unit, The second hydraulic unit is a second shutoff valve that shuts off the flow of the brake fluid between the connecting pipe and the brake fluid supply pipe; a second pressure adjusting unit that adjusts the pressure of the brake fluid supplied to the plurality of second wheel cylinders; a second control unit that controls opening and closing of the second shutoff valve and the second pressure adjusting unit, a third pressure adjusting unit that adjusts the brake fluid pressures supplied from the first pressure adjusting unit to the first wheel cylinders; a fourth pressure adjusting unit that adjusts the brake fluid pressures supplied from the second pressure adjusting unit to the second wheel cylinders; a third control unit that controls the third pressure adjusting unit and the fourth pressure adjusting unit; Equipped with the first control unit and the second control unit open both the first shut-off valve and the second shut-off valve, respectively, when detecting a failure of at least one of the first hydraulic pressure unit and the second hydraulic pressure unit; The third control unit controls the third pressure adjustment unit and the fourth pressure adjustment unit in cooperation with the second pressure adjustment unit when a failure of the first control unit is detected. A brake device characterized by:

2. A brake device mounted on a vehicle, a first hydraulic unit that supplies brake fluid to a plurality of first wheel cylinders; a second hydraulic unit that supplies brake fluid to the second wheel cylinders; a connecting pipe that connects the first hydraulic pressure unit and the second hydraulic pressure unit and allows the brake fluid to flow, The first hydraulic unit is a first shutoff valve that shuts off the flow of the brake fluid between the connecting pipe and the first shutoff valve; a first pressure adjusting unit that adjusts the pressure of the brake fluid supplied to the plurality of first wheel cylinders; a first control unit that controls opening and closing of the first shutoff valve and the first pressure adjusting unit, The second hydraulic unit is a second shutoff valve that shuts off the flow of the brake fluid between the connecting pipe and the brake fluid supply pipe; a second pressure adjusting unit that adjusts the pressure of the brake fluid supplied to the plurality of second wheel cylinders; a second control unit that controls opening and closing of the second shutoff valve and the second pressure adjusting unit, a third pressure adjusting unit that adjusts the brake fluid pressures supplied from the first pressure adjusting unit to the first wheel cylinders; a fourth pressure adjusting unit that adjusts the brake fluid pressures supplied from the second pressure adjusting unit to the second wheel cylinders; a third control unit that controls the third pressure adjusting unit and the fourth pressure adjusting unit; Equipped with the first control unit and the second control unit open both the first shut-off valve and the second shut-off valve, respectively, when detecting a failure of at least one of the first hydraulic pressure unit and the second hydraulic pressure unit; A brake device characterized in that, when a failure of the second control unit is detected, the third control unit controls the third pressure regulating unit and the fourth pressure regulating unit in cooperation with the first pressure regulating unit.

3. The brake device according to claim 1 or 2, the first control unit is connected to the first communication unit, the second communication unit, and a first power source; the second control unit is connected to the first communication unit, the second communication unit, and a second power source; The brake device, wherein the third control unit is connected to the first communication unit, the second communication unit, the first power source, and the second power source.

4. The brake device according to claim 1 or 2, The third control unit is a fourth control unit that is located in the same unit as the first control unit and controls the third pressure adjusting unit; a fifth control unit that is located in the same unit as the second control unit and controls the fourth pressure adjusting unit; A brake device comprising:

5. 5. The brake device according to claim 4, the first control unit is connected to the first communication unit, the second communication unit, and a first power source; the second control unit is connected to the first communication unit, the second communication unit, and a second power source; the fourth control unit is connected to the first communication unit, the second communication unit, the first power source, and the second power source; The brake device, wherein the fifth control unit is connected to the first communication unit, the second communication unit, the first power source, and the second power source.

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