Improved redundant power supply for electromechanical brake system of vehicle

Abstract

The invention discloses a redundant power supply system (rPMS) for an electromechanical brake system of a vehicle, comprising at least two brake circuits (1) and (2), each comprising at least two energy storage modules (10, 15) connected in series so that the two modules can collectively power wheel end brake actuators (17, 18).

Description

Technical Field

[0001] This invention relates to an improved redundant power supply for an electromechanical braking system of a vehicle, preferably a commercial vehicle. Background Technology

[0002] With the ongoing trend of electrification, electromechanical braking systems (EMBS) have gained attention, achieving more precise braking control and faster response solely through electrical signals and energy media. Although pneumatic or hydraulic systems are currently the most common solutions in the commercial vehicle sector, EBS offers numerous advantages, ranging from reduced size and weight to lower environmental emissions.

[0003] These advantages are only realized when the braking system meets regulatory standards and specific safety requirements. The electricity required for the operation and control of the brake actuators is stored and transmitted by the power supply system. Because a failure in this power supply system can impair the vehicle's braking capability, multiple levels of redundancy are needed to improve the system's reliability and availability.

[0004] Traditional pneumatic or hydraulic braking systems use air or hydraulic fluid as the medium to generate and transmit braking signals and forces. Electromechanical braking, however, is a technology that uses only electricity to generate and transmit braking signals and forces. In the event of a power transmission failure, the driver cannot rely on any pneumatic or hydraulic backup system.

[0005] If the power supply system fails without any backup, there is a potential risk of loss of braking function and inability to achieve the expected braking performance and stability. The wheel-end actuators and control units of the electromechanical braking system require a stable and sufficient power supply to function properly. Therefore, a redundant power supply system (rPMS) is needed to meet the braking performance requirements mandated by the driver or automated driving system.

[0006] For example, EP3626505A1 discloses a system and method for providing redundant power. This patent discloses a redundant power supply system for powering at least one vehicle component, comprising at least one power management unit connected to the vehicle's electrical grid and one or more storage units for storing electrical energy. The vehicle component is connected to at least two storage units to achieve redundant power supply.

[0007] Other existing technologies can be found, for example, in WO2023001770A1 or EP4077079A1. Summary of the Invention

[0008] The purpose of this invention is to provide an improved redundant power supply for electromechanical braking systems.

[0009] This objective is achieved by the system described in the independent claim. Other advantageous improvements fall within the scope of the dependent claims.

[0010] This invention discloses a solution in which an electromechanical braking system has at least two independent circuits, each powered by a dedicated power supply unit. Each power supply unit is divided into two energy storage device sub-modules connected in series. A DC / DC converter is responsible for charging the energy storage devices from the vehicle's onboard electrical grid, and another DC / DC converter is used to balance the charge levels between the sub-modules. Since the function of the other DC / DC converter is to balance the charge, Automotive Safety Integrity Level (ASIL) certification is not required. The U1 voltage level is used to power the operation of the brake actuators, and the U2 voltage level in each circuit is used to power the electronic control units (ECUs) and sensors. In the event of a failure in an upstream sub-module, the U2 voltage level can still be provided from the downstream power supply module to ensure the implementation of the aforementioned control electronic functions.

[0011] Specifically, the present invention discloses a solution in which a redundant power supply system includes at least two braking circuits, each braking circuit containing at least two energy storage device modules connected in series, so that the two modules can jointly power the braking actuator.

[0012] Preferably, the redundant power system (rPMS) includes a safety switch, more preferably an intelligent safety switch, for the at least two energy storage modules, configured such that the energy storage modules can be decoupled via the safety switch.

[0013] The advantage of smart fuses and smart switches lies in their protective capabilities. If one component fails (such as a short circuit), other components or other parts of the circuit can be decoupled and protected. This ensures that parts of the circuit still operate, and reduces costs because it eliminates the need to replace all components in the event of a failure.

[0014] Furthermore, they can measure current and voltage and are controlled by an electronic control unit (ECU), thus responding faster than fuses and making them more suitable for safety-related applications. The difference between them is not significant. Switches are used between two active components (such as DC / DC converters or energy storage devices), while fuses are used between the load and the energy source.

[0015] Preferably, the redundant power supply system (rPMS) includes a smart fuse for the wheel-end brake actuator, configured such that the wheel-end brake actuator can be decoupled through the smart fuse.

[0016] Advantageously, the redundant power system (rPMS) includes at least one DC / DC converter to provide the power required to charge the energy storage module.

[0017] Typically, commercial vehicle systems are equipped with a redundant power supply system (rPMS) for electromechanical braking systems. In this system, each braking circuit contains at least two energy storage modules connected in series, configured such that the downstream portion of the modules supplies power to safety-critical loads / equipment.

[0018] Preferably, the system includes a smart fuse configured to decouple safety-critical loads. Its advantages are the same as described above.

[0019] The safety-critical load is preferably a brake control electronic control unit (ECU), a redundant foot brake sensor, a redundant trailer control module, a manual control module, or any sensor.

[0020] This makes it possible to power a variety of loads, etc.

[0021] The system preferably includes a DC / DC converter for achieving charge balance between the upstream and downstream energy storage modules connected in series.

[0022] Since the energy storage modules provide the U2 voltage level to the load, the DC / DC converter is used to balance the charge levels between the energy storage modules.

[0023] The system preferably includes a smart safety switch configured to decouple the DC / DC converter via the smart safety switch. Its advantages are the same as described above.

[0024] The system is preferably configured such that, in the event of a failure in the upstream energy storage module, the downstream energy storage module can still provide power output to safety-critical loads.

[0025] The system can tolerate the failure of the upstream module and still provide the U2 voltage level (of course, the U1 voltage level will be lost, but the U2 voltage level may be sufficient to perform certain tasks).

[0026] The redundant power supply system preferably includes a normally closed switch to ensure power supply to the foot brake sensor in the (ignition) off state.

[0027] This measure improves the safety of the braking system even when the vehicle is stationary and closed. Attached Figure Description

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and preferred embodiments.

[0029] Figure 1 A schematic diagram of a redundant electromechanical braking system for a commercial vehicle is shown.

[0030] Figure 2A schematic diagram of the circuitry for a braking system with a focus on power management is shown.

[0031] Figure 3 The two circuits 1 and 2 of the braking system are shown, with a focus on the redundant power supply system rPMS module and its contents.

[0032] Figure 4 A circuit is shown that has a normally closed switch for powering a redundant foot brake sensor rFBS when the vehicle is off. Detailed Implementation

[0033] Figure 1 This illustrates the braking system architecture with redundant power supplies for a commercial vehicle. The electromechanical braking system consists of the following main components:

[0034] There are at least two independent main braking circuits 1 and 2. The braking system is redundantly powered by redundant power management systems (rPMS) 102 and 103. The energy storage devices of both redundant power management systems (rPMS) are connected to and charged from the vehicle's onboard electrical network 101. In this example, redundant power management system rPMS 102 is dedicated to powering the front axle, and redundant power management system rPMS 103 is dedicated to powering the rear axle.

[0035] If present, the manual control unit (HCU) 107, the redundant foot brake sensor (rFBS) 108, and the redundant trailer control module (rTCM) 109 all receive redundant power from each power supply circuit.

[0036] The front axle wheel-end actuators 104 and 105 obtain the U1 voltage level required for actuation braking from the redundant power management system rPMS 102. The electronic control unit (ECU) 106 of the first braking circuit and the sensors within the wheel-end actuators 104 and 105 obtain the U2 voltage level required for operation from the redundant power management system rPMS 102.

[0037] Similarly, the rear axle wheel-end actuators 111 and 112 obtain the U1 voltage level required for actuation braking from the redundant power management system rPMS 103. The electronic control unit (ECU) 110 of the second circuit, as well as the sensors within the wheel-end actuators 111 and 112, obtain the U2 voltage level required for operation from the redundant power management system rPMS 103.

[0038] Energy recovery from the brake actuator is feasible and is handled by the corresponding redundant power management system (rPMS) module.

[0039] Each power supply circuit is equipped with a Smart Safety Switch (SSSW) to decouple the circuit from the vehicle's electrical grid and between circuits. In addition, multiple Smart Fuses (SFs) are provided to protect different loads / equipment in the event of a failure in other electrical devices.

[0040] Figure 2 The redundant power management system (rPMS) unit in circuit 1 is shown. In circuit 1, smart safety switches SSSW 2 and 4 decouple the DC / DC converter 3 to meet the safety requirement of circuit isolation in the event of a failure of the DC / DC converter 3 itself. Similarly, smart safety switches SSSW 5 and 11 decouple the charge-balancing DC / DC converter 9. Another smart safety switch SSSW 12 isolates the two energy storage modules 10 and 15, and smart safety switch SSSW 6 decouples the energy storage modules 10 and 15 from the vehicle power grid path.

[0041] Smart fuse SF7 protects wheel-end brake actuator 17, smart fuse SF8 protects wheel-end brake actuator 18, while smart fuse SF13 protects electronic control unit (ECU) 19, and smart fuse SF14 protects manual control unit (HCU) 20.

[0042] The power input path of this circuit is connected to the vehicle's onboard electrical network 1 via a DC / DC converter 3. The DC / DC converter 3 is used to perform power conversion to meet the requirements of the energy storage device.

[0043] Two energy storage modules 15 and 10, each with a U2 voltage level, are connected in series. Module 10 is the upstream energy storage module, and module 15 is the downstream energy storage module. Together, they provide the U1 voltage level required by the wheel-end brake actuators 17 and 18. Furthermore, a DC / DC converter 9 is used to achieve active charge balancing between the upstream energy storage module 10 and the downstream energy storage module 15, ensuring coordinated operation of the series-connected energy storage devices and balancing their charge levels. This is because the downstream module 15 is responsible for providing the U2 voltage level to the electronic control unit (ECU) 19 and other loads. Since the DC / DC converter 9 does not directly supply power to the electrical equipment, and the entire system relies on the ASIL-level power output of energy storage modules 10 and 15, a quality management (QM) level DC / DC converter 9 is sufficient.

[0044] The proposed energy storage module (such as a battery) configuration ensures that, in the event of a failure of the upstream energy storage module 10, the downstream module 15 can still provide the U2 voltage level to loads such as the electronic control unit (ECU) 19 and the manual control unit (HCU) 20. The electronic control unit (ECU) 19 can also power such loads, such as the foot brake sensor 21 and the redundant trailer control module 22.

[0045] The setup of circuit 2 is similar to that described above, see... Figure 3 .

[0046] Figure 4 The layout illustrates a redundant power management system (rPMS) with an additional normally closed smart fuse SF-NC 16. SF-NC 16 powers the redundant foot brake sensor 21 when the vehicle is in the (ignition) off state and the braking system is deactivated, so that movement of the brake pedal can trigger a braking event even when the vehicle is off. When the vehicle is in the (ignition) on state and the redundant power management system rPMS is running, SF-NC 16 is disconnected, and the redundant foot brake sensor 21 can be directly powered by the brake control electronic control unit 19.

[0047] List of reference numerals

[0048] 1. Vehicle-mounted electrical grid

[0049] 2 Intelligent Safety Switch SSSW

[0050] 3 DC / DC converters (for charging)

[0051] 4 Intelligent Safety Switch SSSW

[0052] 5 Intelligent Safety Switch SSSW

[0053] 6 Intelligent Safety Switch SSSW

[0054] 7 Smart Fuse SF

[0055] 8 Smart Fuse SF

[0056] 9 DC / DC converters (for balancing)

[0057] 10 (Upstream) Energy Storage Module

[0058] 11 Intelligent Safety Switch SSSW

[0059] 12 Intelligent Safety Switches SSSW

[0060] 13 Smart Fuse SF

[0061] 14 Smart Fuse SF

[0062] 15 (Downstream) Energy Storage Module

[0063] 16 Smart Fuse SF-NC

[0064] 17 Wheel-end brake actuator

[0065] 18 Wheel-end brake actuators

[0066] 19. Brake Control Electronic Control Unit ECU1

[0067] 20 Manual Control Unit (HCU)

[0068] 21 Foot brake sensor

[0069] 22 Redundant Trailer Modules

[0070] 23 Intelligent Safety Switch SSSW

[0071] 24 DC / DC converter (for charging)

[0072] 25 Smart Safety Switch SSSW

[0073] 26 Smart Fuse

[0074] 27 Smart Fuse

[0075] 28 Smart Safety Switch SSSW

[0076] 29 Smart Safety Switch SSSW

[0077] 30 (Upstream) Energy Storage Module

[0078] 31 DC / DC converter (for balancing)

[0079] 32 Intelligent Safety Switch SSSW

[0080] 33 Smart Fuse SF

[0081] 34 Smart Fuse SF

[0082] 35 Smart Safety Switch SSSW

[0083] 36 (Downstream) Energy Storage Module

[0084] 37 Brake Control Electronic Control Unit ECU1

[0085] 38 Wheel-end brake actuator

[0086] 39 Wheel-end brake actuator

[0087] 40. Redundant Power Management System (rPMS) (Circuit 1)

[0088] 41 Redundant Power Management System (rPMS) (Circuit 2)

[0089] 101 Vehicle-mounted electrical grid

[0090] 102 Redundant Power Management System (rPMS) (Circuit 1)

[0091] 103 Redundant Power Management System rPMS (Circuit 2)

[0092] 104 Wheel-end brake actuator

[0093] 105 Wheel-end brake actuator

[0094] 106 Electronic Control Unit (ECU) Circuit 1)

[0095] 107 Manual Control Unit (HCU)

[0096] 108 Redundant Foot Brake Sensors rFBS

[0097] 109 Redundant Trailer Control Module (rTCM)

[0098] 110 Electronic Control Unit (ECU) of the Second Circuit

[0099] 111 Wheel-end brake actuator

[0100] 112 Wheel-end brake actuator

Claims

1. A redundant power supply system (rPMS) for an electromechanical braking system of a vehicle, characterized in that, The redundant power supply system includes at least two braking circuits, each braking circuit including at least two energy storage modules (10, 15), the at least two energy storage modules (10, 15) being connected in series so that the at least two modules can jointly power the braking actuators (17, 18).

2. The redundant power supply system rPMS according to claim 1, characterized in that, The redundant power system includes a safety switch for the at least two energy storage modules, preferably an intelligent safety switch, wherein the safety switch is configured to allow the energy storage modules to be decoupled via the safety switch.

3. The redundant power supply system rPMS according to claim 1, characterized in that, The redundant power system includes a smart fuse for the wheel-end brake actuator, the smart fuse being configured to decouple the wheel-end brake actuator via the smart fuse.

4. The redundant power supply system rPMS according to claim 1, characterized in that, The redundant power system includes at least one DC / DC converter (3) to provide the power required to charge the energy storage module.

5. The redundant power supply system rPMS according to any one of the preceding claims, characterized in that, The redundant power system includes at least two energy storage modules (10, 15) connected in series in each braking circuit, the energy storage modules being configured such that the downstream portion of the module supplies power to safety-critical loads / equipment.

6. The redundant power supply system rPMS according to claim 5, characterized in that, The redundant power system includes smart fuses (7, 8, 13, 14), which are configured to decouple the safety-critical loads.

7. The redundant power supply system rPMS according to claim 5 or 6, characterized in that, The safety-critical load is the brake control electronic control unit (19), redundant foot brake sensor (21), redundant trailer control module, manual control module (20), or any sensor.

8. The redundant power supply system rPMS according to any one of claims 1 to 7, characterized in that, The redundant power system further includes a DC / DC converter (9) configured to achieve balance between the energy storage modules (10, 15), preferably achieving balance between the upstream energy storage module (10) and the downstream energy storage module (15) connected in series.

9. The redundant power supply system rPMS according to claim 8, characterized in that, The redundant power supply system includes intelligent safety switches (5, 11) configured to decouple the DC / DC converter (9) via the intelligent safety switches (5, 11).

10. The redundant power supply system rPMS according to claim 5, characterized in that, The redundant power system is configured such that in the event of a failure of the upstream energy storage module (10), the downstream energy storage module (15) can still provide power output to safety-critical loads.

11. The redundant power supply system rPMS according to any one of the preceding claims, characterized in that, The redundant power supply system includes a normally closed switch (16) to ensure power supply to the foot brake sensor (21) when the ignition is off.

12. A commercial vehicle system equipped with a redundant power supply system according to any one of the preceding claims.

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