BRAKE ARCHITECTURE FOR A COMBINED HYDRAULIC AND ELECTROMECHANICAL BRAKE SYSTEM

Abstract

The disclosure provides a "brake architecture for a combined hydraulic and electromechanical braking system." A braking system includes a first hydraulic brake assembly assigned to a first front wheel, a second hydraulic brake assembly assigned to a second front wheel, a front EBB module operatively coupled to the first and second hydraulic brake assemblies for the primary operation of the first and second hydraulic brake assemblies, a first EMB assembly assigned to a first rear wheel, a second EMB assembly assigned to a second rear wheel, a controller operatively coupled to the first and second EMB assemblies for the primary operation of the first and second EMB assemblies, a first power grid and a second power grid providing redundant power supply for the system, and a bus network.that both the EBB module and the controller are coupled with the first and second EMB assemblies, so that the EBB module can provide control of a safety operation of the first and second EMB assemblies when the controller is not operational.

Description

TECHNICAL FIELD

[0001] Exemplary embodiments generally relate to vehicle braking systems and in particular a system that provides redundant power for brake assemblies of different types. BACKGROUND

[0002] Brake force boosting systems are commonly used in automotive applications to increase the force a driver applies to the brake pedal to acceptable levels, ensuring proper braking performance when hydraulic brakes are used. Electromechanical brakes (EMBs) are also becoming increasingly popular, often as an alternative to hydraulic brakes. When a combination of hydraulic brakes and EMBs is used on the same vehicle, a challenge can arise in providing redundant power supplies and signaling for the activation of each different brake system type.

[0003] Therefore, it may be desirable to develop an architecture that provides redundant power supply and signaling capabilities with respect to different types of braking systems. BRIEF PRESENTATION OF SOME EXAMPLES

[0004] According to an exemplary embodiment, a vehicle braking system can be provided. The system can include a first hydraulic brake assembly assigned to a first front wheel, a second hydraulic brake assembly assigned to a second front wheel, a front electronic brake force booster module (EBB module) operatively coupled to the first and second hydraulic brake assemblies to control the primary operation of the first and second hydraulic brake assemblies, a first electromechanical brake assembly (EMB assembly) assigned to a first rear wheel, a second EMB assembly assigned to a second rear wheel, a controller operatively coupled to the first and second EMB assemblies to control the primary operation of the first and second EMB assemblies, and a first power supply and a second power supply that provide redundant power for the system.and a communication bus network that couples both the EBB module and the controller with the first and second EMB assemblies to enable the EBB module to provide control of a backup operation of the first and second EMB assemblies when the controller is not operational.

[0005] In another exemplary embodiment, a communication bus network can be provided for a vehicle braking system. The vehicle braking system includes a first hydraulic brake assembly assigned to a first front wheel, a second hydraulic brake assembly assigned to a second front wheel, a front EBB module operatively coupled to the first and second hydraulic brake assemblies to control the primary operation of the first and second hydraulic brake assemblies, a first EMB assembly assigned to a first rear wheel, a second EMB assembly assigned to a second rear wheel, a controller operatively coupled to the first and second EMB assemblies to control the primary operation of the first and second EMB assemblies, and a first power grid and a second power grid providing redundant power supply for the system.The communication bus network can include a first communication bus that operatively couples the first and second EMB modules to the EBB module, and a second bus network that operatively couples the first and second EMB modules to the controller. The communication bus network operatively couples both the EBB module and the controller to the first and second EMB modules, enabling the EBB module to control the safety operation of the first and second EMB modules when the controller is inoperative. BRIEF DESCRIPTION OF THE MULTIPLE VIEWS OF THE DRAWING(S)

[0006] Having thus generally described the invention, reference is now made to the accompanying drawings, which are not necessarily drawn to scale and in which: Fig. 1 illustrates a block diagram of a vehicle control system according to an exemplary embodiment; Fig. Figure 2 illustrates a block diagram of some components of the vehicle control system of Fig. 1 according to an exemplary embodiment; Fig. Figure 3 illustrates a block diagram of a signaling system decided by an EBB module associated with a brake control system according to an exemplary embodiment; and Fig. Figure 4 illustrates a block diagram of a gateway that manages signals between communication buses according to an exemplary embodiment. DETAILED DESCRIPTION

[0007] Some embodiments are now described in more detail below with reference to the accompanying drawings, which illustrate some, but not all, of the embodiments. In fact, the examples described and illustrated in this document should not be interpreted as limiting the scope, applicability, or configuration of the present disclosure. Rather, these embodiments are provided to enable this disclosure to meet applicable requirements. The same reference numerals refer throughout to the same elements. Furthermore, the expression "or," as used in this document, is to be interpreted as a logical operator that evaluates to true if one or more of its operands are true.As used in this document, active coupling is understood to mean a direct or indirect connection which in any case enables a functional connection of components which are actively coupled to one another.

[0008] Normally, redundancy for a purely hydraulic braking system is provided by mechanically-hydraulically depressing a brake pedal at a hydraulic cylinder that supplies brake pressure to all four wheel hubs. In some situations and vehicle architectures, the rear brake circuits are isolated from the front during mechanical-hydraulic depressurization, with the rear electric parking brakes being used to provide additional braking torque. Architectures with front electronic brake boosters (EBBs) that are hydraulic and electromechanical brakes (EMBs) on the rear axle in passenger cars require a redundant power supply and a supporting control structure. However, as noted above, this can be difficult to achieve in a context where different braking systems are used, and signaling in backup operating modes can also be challenging.Exemplary embodiments aim to provide separate electronic control units (ECUs) for each of the rear EMBs, each powered by a different power source, but signaling in backup modes (i.e., when central control is unavailable for the ECUs) can be provided via the EBB module using a network bus architecture that provides backup signaling when required.

[0009] Fig. Figure 1 illustrates a block diagram of a vehicle control system 100 of an exemplary embodiment. The components of the control system 100 can be integrated into a vehicle 110 (e.g., by being operatively coupled to a chassis of the vehicle 110, various components of the vehicle 110, and / or electronic control systems of the vehicle 110). It should be noted that, although the components are made of Fig. 1 may be operatively coupled to the vehicle 110, it is understood that such a connection may be either direct or indirect. Furthermore, some of the components of the control system 100 may be connected to the vehicle 110 via interconnections to other components of either the chassis or other electronic and / or mechanical systems or components.

[0010] The control system 100 can include one or more input devices in the form of one or more control pedals. In some embodiments, the control pedals can include a brake pedal 120, which is generally foot-operated by an operator 125 to initiate braking forces or the application of braking torque to the wheels of the vehicle 110. The brake pedal 120 can be operatively coupled to hydraulic brakes 130 (e.g., front brakes) via mechanical and / or hydraulic links under the control of an EBB module 135. The brake pedal 120 can also be connected to the EMBs 140 (e.g., rear brakes) via a brake pedal position sensor 142.The EMBs 140 can be operatively coupled to the rear brakes, and the EMBs 140 can be actuated in response to the operation of corresponding instances of ECUs 144, which receive instructions from a vehicle control module (VCM) 146 that is operatively coupled to the brake pedal position sensor 142 to receive position information indicating the brake pedal 120. The brake pedal position sensor 142 can provide data indicating the exact position of the brake pedal 120 as input to the VCM 146.

[0011] In particular, the control pedals could alternatively be operated manually or any other operable element through which the operator 125 can provide input indicating the operator's intention regarding the control of the net torque to be applied to the wheels of the vehicle 110. In some cases, the control system 100 may be configured to perform other tasks, which may or may not involve a drive and brake control operation or power management. In one exemplary embodiment, the control system 100 can receive information that is used to determine the vehicle status of various components or subassemblies 150 of the vehicle 110.Additionally or alternatively, various sensors may be included that can be operatively coupled to the components or subassemblies 150 and provide inputs to the control system 100, which are used to determine the vehicle status. Such sensors can be part of a sensor network 160, and sensors of the sensor network 160 can be operatively coupled to the control system 100 (and / or the components or subassemblies 150) via one or more instances of a vehicle communication bus 170 (e.g., a controller area network (CAN) bus).

[0012] The components or subassemblies 150 may, for example, include a braking system, a drive system, a steering system, and / or a wheel assembly of the vehicle 110. The braking system may be configured to provide braking inputs to braking components of the vehicle 110 and includes the components discussed above. One or more corresponding sensors of the sensor network 160, which may be operatively coupled to the braking system and / or the wheel assembly, may provide information regarding braking torque, braking torque rate, vehicle speed (including rate of change of speed), front / rear wheel speeds, vehicle tilt, etc. Inputs from the sensors of the sensor network 160 may be provided to the control system 100 to enable the control system 100 to provide various primary and secondary (or backup) control functions with respect to the components or subassemblies 150.Accordingly, the control system 100 can, for example, be capable of receiving numerous different parameters, specifications, and other information relating to or indicating various situations or conditions associated with the vehicle status. The control system 100 can also receive information indicating the operator's intention 125 regarding the control of various aspects of the vehicle's operation 110 and then be configured to use the received information to issue instructions for controlling responses to those specific situations or conditions. The control system 100 is made of... Fig. 1 can be similar to conventional systems in many respects, except that the control system 100 can be modified to respond to situations where a safety current and safety signaling for the EMBs 140 are required, as referred to in the Fig. 2-4 described in more detail.

[0013] Fig. Figure 2 illustrates a block diagram of various components of a control system 200, which can be used either as a specific example of the control system 100 from Fig. 1 or as a part thereof that is associated with a vehicle braking system. In this respect, for example, it illustrates Fig. 2 exemplary interactions under normal operating conditions for the control system 200 between the brake pedal 120, the EBB module 135 and the VCM 146 of Fig. 1 and various other elements of the components or subassemblies 150 with respect to information received thereby (e.g. from the sensor network 160, from various components / subassemblies 150 and / or from the operator 125).

[0014] The control system 200 can include the brake pedal 120, which can have the corresponding brake pedal position sensor 142 for determining a position of the brake pedal 120 and for providing a signal or input to the VCM 146, which indicates the determined position. The hydraulic brakes 130 from Fig. 1. The first hydraulic brake assembly 210, which is assigned to one of the wheels 212 (e.g., a left front wheel) of the vehicle 110, and the second hydraulic brake assembly 220, which is assigned to another of the wheels 212 (e.g., a right front wheel) of the vehicle 110, can include a first hydraulic brake assembly 210, which is assigned to one of the wheels 212 (e.g., a right front wheel). Each of the first and second hydraulic brake assemblies 210 and 220 can include corresponding instances of a brake caliper or brake drum for providing friction braking of the corresponding assigned wheels 212. Hydraulic power for actuating the first and second hydraulic brake assemblies 210 and 220 can be provided by the EBB module 135 via respective instances of hydraulic lines 222. Each of the wheels 212 assigned to the first and second hydraulic brake assemblies 210 and 220 can also have a corresponding assigned wheel speed sensor (e.g., a speedometer).the first front wheel speed sensor (FFWSS) 224 and the second front wheel speed sensor (SFWSS) 226) to measure the wheel speed of the corresponding wheel 212 and to provide information about the measured wheel speed to the EBB module 135.

[0015] The control system 200 can also include a first EMB 240, which is assigned to one of the corresponding wheels 212 (e.g., a left rear wheel), and a second EMB 242, which is assigned to another corresponding wheel 212 (e.g., a right rear wheel). The first and second EMB 240 and 242 are examples of the EMBs 140 from Fig. 1, and the ECUs 144 from Fig. 1 can be exemplified by the first ECU 250 and the second ECU 252 from Fig. Figure 2 shows the following. The first ECU 250 can be operatively coupled to a first motor 260, which can actuate a brake caliper or a brake drum (based on the application of the brake pedal 120) under the control of the first ECU 250 to provide braking torque to the wheel 212 (e.g., the left rear wheel). The second ECU 252 can be operatively coupled to a second motor 262, which can actuate a brake caliper or a brake drum (based on the application of the brake pedal 120) under the control of the second ECU 252 to provide braking torque to the wheel 212 (e.g., the right rear wheel).

[0016] The wheel speed for wheel 212 corresponding to the first EMB 240 (e.g., the left rear wheel) can be measured by a first wheel speed sensor (WSS) 270, and the wheel speed for wheel 212 corresponding to the second EMB 242 (e.g., the right rear wheel) can be measured by a second WSS 272. The first WSS 270 can provide the first ECU 250 with a reading of the wheel speed measured for the corresponding wheel 212 (e.g., the left rear wheel), and the second WSS 272 can provide the second ECU 252 with a reading of the wheel speed measured for the corresponding wheel 212 (e.g., the right rear wheel).

[0017] The first and second ECUs 250 and 252 receive an electronic instruction from the VCM 146 to initiate braking functions via the first and second EMBs 240 and 242, respectively. Therefore, there is no mechanical / hydraulic connection between the brake pedal 120 and the rear brakes in this example (whereas such a connection exists for the front brakes). Since these instructions are transmitted electronically, redundant power supplies are used to ensure that braking can still occur even if one of the power supplies fails for any reason. Accordingly, a first power supply 280 is provided to power the first EMB 240, the first ECU 250, and the first motor 260. A second power supply 282 is provided to power the second EMB 242, the second ECU 252, and the second motor 262.In this example, the first power grid 280 also supplies power to the VCM 146, and the second power grid 282 also supplies power to the EBB module 135. Thus, all electronic components required for braking are supplied with power from different power supplies and corresponding grids to ensure that power is available for braking. However, the signaling to ensure that the powered components receive the signaling required to implement the desired or necessary braking can be a completely different matter. In one exemplary embodiment, the first power grid 280 can be a quality management (QM) power source, and the second power grid 282 can be an ISIL-B power source. In alternative embodiments, however, other power sources can be used.

[0018] The first ECU 250 and the second ECU 252 can each be operatively coupled to the VCM 146 to receive control instructions from it via a first communication bus 290 (e.g., a public CAN). As discussed above, the VCM 146 is the primary control source for providing control signals to the first and second ECUs 250 and 252. However, if the VCM 146 fails or is inoperable for any reason (e.g., failure of the first power supply 280, failure of communication to / from the VCM 146, etc.), backup signaling for the first and second ECUs 250 and 252 can be provided via a communication bus network in which the EBB module 135 is integrated as a backup control signal source. To achieve this, a second communication bus 292 (e.g. a private CAN) can be integrated into the communication bus network, which couples the first and second ECU 250 and 252 with the EBB module 135.However, in some cases, the second communication bus 292 could also be split into two separate private CAN buses. For example, by using the first and second communication buses 290 and 292, if the VCM 146 is inoperable for any reason and the primary signaling for controlling brake functions at the first and second ECUs 250 and 252 is therefore interrupted or unavailable, a backup signaling regarding the brake functions of the first and second ECUs 250 and 252 can be provided by the EBB module 135 via the second communication bus 292.

[0019] Thus, for example, if a braking torque request of 1000 Nm is generated at the VCM 146 (based on the position of the brake pedal 120), instructions would normally be provided by the VCM 146 via the first communication bus 290 to the first and second ECUs 250 and 252, instructing the first EMB 240 to apply 500 Nm of braking torque, and instructing the second EMB 242 to apply 500 Nm of braking torque. A failure of the VCM 146 and / or the first communication bus 290 would then be addressed by the EBB module 135 providing a corresponding instruction via the second communication bus 292 to each of the first and second ECUs 250 and 252 to apply braking torques to the first and second EMBs 240 and 242, which could also each be approximately 500 Nm of braking torque.

[0020] Exemplary embodiments therefore provide a central vehicle control module or central vehicle controller (e.g., the VCM 146) for primary brake control with an EBB module as a secondary control option, each powered by a different power source. The backup function of the second communication bus 292 can ensure that the EMBs can be provided with redundant signaling and redundant power supplies simultaneously. In some cases, however, other functional capabilities can also be provided to improve conventional systems. For example, in one exemplary embodiment, the first and second EMBs 240 and 242 can also be capable of providing wheel-side anti-lock braking (ABS) functions in response to a failure of one or both of the wheel speed sensors (e.g., the first and / or second WSS 270 and 272).In some cases, the final application of the parking brake can also be achieved due to a communication failure. In this regard, if, for example, a communication failure occurs with both the VCM 146 and the EBB module 135, the first and second ECUs 250 and 252 may be programmed to apply the parking brake as soon as the measured wheel speed (e.g., from the first and second WSS 270 and 272) decreases from zero (and perhaps even stabilizes).

[0021] In some embodiments, the EBB module 135 can perform a braking signal decision for the system. Fig. Figure 3 illustrates a block diagram showing signaling associated with the operation of a vehicle's braking system, where such a decision is implemented according to an exemplary embodiment. In this respect, a pedal force 300 can be applied to the brake pedal 120 and communicated to the EBB module 135. The EBB module 135 can communicate a brake pedal travel estimate 310 to the VCM 146. The brake pedal travel estimate 320 can drive the generation of a brake torque request from the VCM 146 to the first and second EMBs 240 and 242 via a decision at the EBB module 135. In this respect, the VCM 146 can provide a front and rear axle brake torque request 330 to the EBB module 135.A corresponding hydraulic brake actuation 332 can then be provided by the EBB module 135 to the first and second hydraulic brake assemblies 210 and 220, and decisive brake torque requests 340 can also be communicated by the EBB module 135 to the first and second EMBs 240 and 242. The VCM 146 can also provide a parking brake command 350 to the EBB module 135 in order to provide a relay command 352 to the second EMB 242, while a parking brake command 354 is also provided directly to the first EMB 240.

[0022] Although not in Fig. As shown in Figure 2, in some embodiments a component may be provided as a gateway device to act as a gateway between individual buses (e.g., the first and second communication buses 290 and 292) of the communication bus network. Although not required, in some cases the gateway device may be implemented as a High Power Computer Cluster A (HPCCA) 400, as shown in Figure 2. Fig. 4 shown. In this respect, it shows Fig.Figure 4 shows the brake pedal 120, which, based on pedal force, provides an input 410 to the EBB module 135. This input, in turn, generates a hydraulic brake actuation 420 from the EBB module 135 to the first and second hydraulic brake assemblies 210 and 220. Meanwhile, the movement of the brake pedal 120 also causes the brake pedal position sensor 142 to generate a pedal angle 430 for transmission to the VCM 146. The VCM 146 can generate a brake torque request 440 for the rear axle, which can then be split by the HPCCA 400 into separate individual brake torque requests 442 for the first and second EMB 240 and 242. A parking brake request 460 can also be split by the HPCCA 400 into respective individual parking brake requests 462 for the first and the second EMB 240 and 242.

[0023] A vehicle braking system can therefore be provided for a vehicle. The vehicle braking system can include a first hydraulic brake assembly assigned to a first front wheel, a second hydraulic brake assembly assigned to a second front wheel, a front EBB module operatively coupled to the first and second hydraulic brake assemblies to control the primary operation of the first and second hydraulic brake assemblies, a first EMB assembly assigned to a first rear wheel, a second EMB assembly assigned to a second rear wheel, a controller operatively coupled to the first and second EMB assemblies to control the primary operation of the first and second EMB assemblies, a first power grid and a second power grid providing redundant power supply for the system, and a communication bus network.that includes coupling both the EBB module and the controller with the first and second EMB assemblies to enable the EBB module to provide control of a backup operation of the first and second EMB assemblies when the controller is not operational.

[0024] The system in some embodiments may include additional features, modifications, extensions, and / or the like to solve further tasks or improve system performance. These additional features, modifications, extensions, and / or the like can be added in any combination. The following is a list of various additional features, modifications, and extensions, each of which can be added individually or in any combination. For example, the first power grid is operatively coupled with the controller and the first EMB module, and the second power grid is operatively coupled with the EBB module and the second EMB module.In one exemplary embodiment, the communication bus network can comprise a first communication bus network that operatively couples the first and second EMB assemblies to the EBB module, and a second bus network that operatively couples the first and second EMB assemblies to the controller. In some cases, the first bus network can be a private Controller Area Network (CAN) bus, and the second bus network can be a public CAN bus. In one exemplary embodiment, the first power network can be a QM power source, and the second power network can be an ASIL-B power source.In an exemplary embodiment, the first EMB assembly can include a first electronic control unit (ECU), and the second EMB assembly can include a second ECU, wherein the first bus network can extend between the first and second ECUs and the EBB module, and the second bus network can extend between the first and second ECUs and the controller. In an exemplary embodiment, the first and second ECUs can each be operatively coupled to a first wheel speed sensor and a second wheel speed sensor, wherein the first wheel speed sensor provides a wheel speed for the first rear wheel to the first ECU, and the second wheel speed sensor provides a wheel speed for the second rear wheel to the second ECU.In response to a communication failure between the first and second ECUs and both the controller and the EBB module, the first and second ECUs can apply a parking brake to the first and second rear wheels, respectively, when the first and second wheel speed sensors indicate zero wheel speed for the first and second rear wheels. In some cases, the first and second ECUs can provide a wheel-side anti-lock braking system (ABS) function for the first and second rear wheels, respectively, in response to a communication failure of the first and second wheel speed sensors. In an exemplary embodiment, the first and second ECUs can each include a separate motor to provide the first and second rear wheels with the necessary power.To provide braking torque to the second rear wheel, the signaling for the operation of the respective motors of the first and second ECUs is primarily provided via the second bus network and is provided as a backup via the EBB module. In some cases, a brake pedal of the system can be functionally coupled to the controller, and the braking signal to the EBB module is received from the brake pedal by the controller.

[0025] Many modifications and other embodiments of the inventions set forth in this document will be apparent to a person skilled in the art in the field to which these inventions belong, given the teachings presented in the preceding descriptions and the accompanying drawings. It is therefore understood that the disclosure is not limited to the specific implementations disclosed and that modifications and other implementations are to be included within the scope of protection of the appended claims. Furthermore, it is understood that, although the preceding descriptions and the accompanying drawings describe exemplary embodiments within the framework of certain exemplary combinations of elements and / or functions, different combinations of elements and / or functions can be provided by alternative embodiments without deviating from the scope of the appended claims.In this respect, other combinations of elements and / or functions than those expressly described above are also considered, as may be set forth in some of the appended claims. Where advantages, benefits, or solutions to problems are described in this document, it is understood that such advantages, benefits, and / or solutions may be applicable to some embodiments, but not necessarily to all embodiments. Thus, all advantages, benefits, or solutions described in this document should not be considered critical, necessary, or essential for all embodiments or for the subject matter claimed in this document. Although specific terms are used in this document, they are used only in a generic and descriptive sense and not for the purpose of limitation.

[0026] According to the present invention, a vehicle braking system is provided comprising: a first hydraulic brake assembly assigned to a first front wheel; a second hydraulic brake assembly assigned to a second front wheel; a front electronic brake force booster module (EBB module) operatively coupled to the first and second hydraulic brake assemblies to control the primary operation of the first and second hydraulic brake assemblies; a first electromechanical brake assembly (EMB assembly) assigned to a first rear wheel; a second EMB assembly assigned to a second rear wheel; a control unit operatively coupled to the first and second EMB assemblies to control the primary operation of the first and second EMB assemblies; a first power supply network and a second power supply network providing a redundant power supply for the system;and a communication bus network that couples both the EBB module and the controller with the first and second EMB assemblies to enable the EBB module to provide control of a backup operation of the first and second EMB assemblies when the controller is not operational.

[0027] According to one embodiment, the first power grid is operatively coupled with the control unit and the first EMB assembly, and the second power grid is operatively coupled with the EBB module and the second EMB assembly.

[0028] According to one embodiment, the communication bus network comprises a first communication bus network that operatively couples the first and second EMB assemblies with the EBB module, and a second bus network that operatively couples the first and second EMB assemblies with the controller.

[0029] In one embodiment, the first bus network is a private Controller Area Network (CAN) bus, and the second bus network is a public CAN bus. In another embodiment, the first power network is QM power, and the second power network is ASIL-B power.

[0030] According to one embodiment, the first EMB assembly comprises a first electronic control unit (ECU), and the second EMB assembly comprises a second ECU, wherein the first bus network extends between the first and second ECU and the EBB module, and wherein the second bus network extends between the first and second ECU and the controller.

[0031] According to one embodiment, the first and second ECUs are each operatively coupled to a first wheel speed sensor and a second wheel speed sensor, wherein the first wheel speed sensor of the first ECU provides the wheel speed for the first rear wheel and the second wheel speed sensor of the second ECU provides the wheel speed for the second rear wheel, and wherein, in response to a communication failure between the first and second ECUs and both the controller and the EBB module, the first and second ECUs actuate a parking brake on the first and second rear wheel, respectively, when the first and second wheel speed sensors each indicate a wheel speed of zero for the first and second rear wheel.

[0032] According to one embodiment, the first and second ECUs provide a wheel-side anti-lock braking system (ABS) function for the first and second rear wheels, respectively, in response to a communication failure of the first and second wheel speed sensors. According to another embodiment, the first and second ECUs each include a motor to provide braking torque to the first and second rear wheels, respectively, and the signaling for the operation of the respective motor of the first and second ECUs is primarily provided via control over the second bus network and is provided as a backup via the EBB module.

[0033] According to one embodiment, a brake pedal of the system is operatively coupled to the control unit, and the signal to brake to the EBB module is received by the brake pedal through the control unit.

[0034] According to the present invention, a communication bus network is provided for a vehicle braking system, comprising a first hydraulic brake assembly assigned to a first front wheel, a second hydraulic brake assembly assigned to a second front wheel, a front electronic brake force booster module (EBB module) operatively coupled to the first and second hydraulic brake assemblies to control the primary operation of the first and second hydraulic brake assemblies, a first electromechanical brake assembly (EMB assembly) assigned to a first rear wheel, a second EMB assembly assigned to a second rear wheel, a controller operatively coupled to the first and second EMB assemblies to control the primary operation of the first and second EMB assemblies, and a first power network and a second power network providing a redundant power supply for the system.wherein the communication bus network comprises: a first communication bus that operatively couples the first and second EMB assemblies to the EBB module; and a second bus network that operatively couples the first and second EMB assemblies to the controller, wherein the communication bus network operatively couples both the EBB module and the controller to the first and second EMB assemblies in order to enable the EBB module to provide control of the safety operation of the first and second EMB assemblies when the controller is not operational.

[0035] According to one embodiment, the first power grid is operatively coupled with the control unit and the first EMB assembly, and the second power grid is operatively coupled with the EBB module and the second EMB assembly.

[0036] In one embodiment, the first bus network is a private Controller Area Network (CAN) bus, and the second bus network is a public CAN bus. In another embodiment, the first power network is QM power, and the second power network is ASIL-B power.

[0037] According to one embodiment, the first EMB assembly comprises a first electronic control unit (ECU), and the second EMB assembly comprises a second ECU, wherein the first bus network extends between the first and second ECU and the EBB module, and wherein the second bus network extends between the first and second ECU and the controller.

[0038] According to one embodiment, the first and second ECUs are each operatively coupled to a first wheel speed sensor and a second wheel speed sensor, wherein the first wheel speed sensor of the first ECU provides the wheel speed for the first rear wheel and the second wheel speed sensor of the second ECU provides the wheel speed for the second rear wheel, and wherein, in response to a communication failure between the first and second ECUs and both the controller and the EBB module, the first and second ECUs actuate a parking brake on the first and second rear wheel, respectively, when the first and second wheel speed sensors each indicate a wheel speed of zero for the first and second rear wheel.

[0039] According to one embodiment, the first and second ECUs provide a wheel-side anti-lock braking system (ABS) function for the first and second rear wheels, respectively, in response to a communication failure of the first and second wheel speed sensors. According to another embodiment, the first and second ECUs each include a motor to provide braking torque to the first and second rear wheels, respectively, and the signaling for the operation of the respective motor of the first and second ECUs is primarily provided via control over the second bus network and is provided as a backup via the EBB module.

[0040] According to one embodiment, a brake pedal of the system is operatively coupled to the control unit, and the signal to brake to the EBB module is received by the brake pedal through the control unit.

Claims

[1] A communication bus network for a vehicle braking system comprising a first hydraulic brake assembly associated with a first front wheel, a second hydraulic brake assembly associated with a second front wheel, a front electronic brake booster (EBB) module operatively coupled to the first and second hydraulic brake assemblies to control primary operation of the first and second hydraulic brake assemblies, a first electromechanical brake (EMB) assembly associated with a first rear wheel, a second EMB assembly associated with a second rear wheel, a controller operatively coupled to the first and second EMB assemblies to control primary operation of the first and second EMB assemblies, and a first power grid and a second power grid providing redundant power to the system, the communication bus network comprising: a first bus network that operatively couples the first and second EMB modules to the EBB module; and a second bus network that effectively connects the first and second EMB modules to the controller, wherein the communication bus network operatively couples both the EBB module and the controller to the first and second EMB assemblies to enable the EBB module to provide control of the backup operation of the first and second EMB assemblies when the controller is inoperative. [2] The communication bus network of claim 1, wherein the first power network is operatively coupled to the controller and the first EMB module, and the second power network is operatively coupled to the EBB module and the second EMB module. [3] The communication bus network of claim 2, wherein the first bus network is a private controller area network (CAN) bus and the second bus network is a public CAN bus. [4] The communication bus network of claim 3, wherein the first power network is QM power and the second power network is ASIL-B power. [5] A communication bus network according to claim 3, wherein the first EMB assembly comprises a first electronic control unit (ECU) and the second EMB assembly comprises a second ECU, wherein the first bus network extends between the first and second ECUs and the EBB module and wherein the second bus network extends between the first and second ECUs and the controller. [6] The communication bus network of claim 5, wherein the first and second ECUs are each operatively coupled to a first wheel speed sensor and a second wheel speed sensor, the first wheel speed sensor of the first ECU provides a wheel speed for the first rear wheel, and the second wheel speed sensor of the second ECU provides a wheel speed for the second rear wheel, and wherein, in response to a communication failure between the first and second ECUs and both the controller and the EBB module, the first and second ECUs apply a parking brake on the first and second rear wheels, respectively, when the first and second wheel speed sensors each indicate zero wheel speed for the first and second rear wheels. [7] A communication bus network according to claim 6, wherein the first and second ECUs provide a wheel-side anti-lock braking system (ABS) function for the first and second rear wheels, respectively, in response to a communication failure of the first and second wheel speed sensors. [8] A communication bus network according to claim 5, wherein the first and second ECUs each include a respective motor for providing braking torque to the first and second rear wheels, respectively, and wherein signaling for operation of the respective motor is provided to the first and second ECUs primarily via the controller via the second bus network and provided as a backup via the EBB module. [9] The communication bus network of claim 1, wherein a brake pedal of the system is operatively coupled to the controller and the signaling to brake to the EBB module is received from the brake pedal by the controller. [10] Vehicle braking system comprising: a first hydraulic brake assembly associated with a first front wheel; a second hydraulic brake assembly associated with a second front wheel; a front electronic brake boost (EBB) module operatively coupled to the first and second hydraulic brake assemblies to control primary operation of the first and second hydraulic brake assemblies; a first electromechanical brake assembly (EMB assembly) associated with a first rear wheel; a second EMB assembly associated with a second rear wheel; a controller operatively coupled to the first and second EMB assemblies to control primary operation of the first and second EMB assemblies; a first power grid and a second power grid that provide redundant power to the system; and the communication bus network according to one of claims 1 to 9.

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