Hybrid hydraulic / electric brake control system for aircraft
Through the hybrid hydraulic/electrical braking control system, the flexibility and space requirements of the brake system in autonomous vehicles are solved, and precise braking control and leakage prevention design are achieved, which is suitable for various aircraft environments.
Patent Information
- Application Number
- CN202510126764.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2025-01-16
- Filing Date
- 2025-01-27
- Publication Date
- 2025-08-01
AI Technical Summary
The existing aircraft braking systems lack flexibility in autonomous vehicles, cannot achieve automated control, and have large space requirements, and conventional mechanical hydraulics and full electrical systems have their own limitations.
The hybrid hydraulic/electrical braking control system is adopted to control the electrical/mechanical actuator through the electrical braking command signal, and the actuation of the hydraulic master cylinder generates braking force and adjusts through pressure feedback to achieve precise braking. The system consists of port and starboard brake channel units, supports symmetric and asymmetric braking control, has parking braking function and is compactly designed to prevent leakage.
It realizes flexible braking control in autonomous aircraft, reduces dependence on space and resources, supports symmetric and asymmetric braking, ensures accurate braking force and prevents hydraulic leakage, and is suitable for a variety of aircraft environments.
Smart Images
Figure CN120397252A_ABST
Abstract
Description
[0001] Cross - Reference to Related Applications
[0002] This application claims the benefit of domestic priority based on U.S. Provisional Application Serial No. 63 / 626,680, filed on January 30, 2024, the entire content of which is hereby expressly incorporated by reference. Technical Field
[0003] The embodiments disclosed herein generally relate to a hybrid hydraulic / electrical braking control system for an aircraft. In a preferred form, embodiments of the present invention increase the flexibility of mounting a braking system for an aircraft that does not have the minimum requirements to support a conventional aircraft hydraulic braking system (such as an on - board pilot - controlled pedal, a system for generating hydraulic pressure, and / or sufficient space for a hydraulic system). Thus, the hybrid hydraulic / electrical braking control system can be usefully mounted in an autonomous aircraft (i.e., an aircraft without an on - board human pilot). Background Art
[0004] Conventionally, there are three basic solutions for providing a braking system for an aircraft. For example, there is a pure mechanical - hydraulic braking system, where the foot force of the pilot on the control pedal is used to directly control the braking intensity. Thus, this type of mechanical braking system depends on the presence of the pedal and the pilot operator. Thus, conventional mechanical - hydraulic braking systems do not possess automation capabilities.
[0005] Another conventional means of providing a braking action to an aircraft is a by - wire braking system, whereby the application of the force applied by the pilot to the control pedal is converted into electrical signals that are transmitted to a control box, which in turn controls a set of hydraulic valves that apply pressure to the corresponding wheel brake assemblies. All - electrical braking systems are also known, whereby several electro - actuators, typically operating at a relatively high voltage, directly apply the braking force to the wheels. Thus, all - electrical systems depend on power generation that is not typically available on small aircraft.
[0006] While conventional braking systems for aircraft are suitable for their intended purposes, there remains a continuing desire for further improvements and design options. For example, it would be particularly desirable if an aircraft braking system could be developed that is particularly well - suited to relatively light weight, electric vertical take - off and landing (eVTOL), and / or autonomous aircraft designs. The embodiments disclosed herein are intended to meet such a need. Summary of the Invention
[0007] Broadly speaking, the embodiments disclosed herein relate to a novel hybrid hydraulic / electrical braking control system for an aircraft. In a particularly preferred embodiment, the hybrid hydraulic / electrical braking control system is capable of operating in response to an electrical braking command signal that is electrically sent to an electronic control unit, which in turn controls an electro-mechanical actuator. The electro-mechanical actuator then responds by applying a force and displacement to a hydraulic master cylinder that is proportional to the command signal sent to the electronic control unit. The actuator movement is then converted by the hydraulic master cylinder into a hydraulic pressure sufficient to actuate an aircraft brake associated with an aircraft main wheel assembly. The pressure generated by the hydraulic master cylinder is fed back to the electronic control unit via a pressure sensor to compensate for internal variables (e.g., backlash, clearance, non-linearity, etc.) and external variables (e.g., temperature, altitude, etc.) to precisely achieve the desired braking force commanded.
[0008] According to several preferred embodiments, the hybrid hydraulic / electrical braking control system consists of two isolated and independently operable port and starboard brake channel units and is thus capable of achieving symmetric and asymmetric braking control. With such a feature, linear braking (e.g., using symmetric braking control) and directional control (i.e., using asymmetric braking control) of the aircraft can be applied during ground maneuvers.
[0009] The hybrid hydraulic / electrical braking control system of the embodiments disclosed herein can also perform a parking brake function by a full command of the electro-mechanical actuator and a sequential closing of normally closed solenoid valves (optionally, together with an internal locking device associated with the electro-mechanical actuator, which is also controlled by a control drive unit to create a braking pressure lock). The hydraulic / electrical braking control system of the embodiments disclosed herein is very compact and can be encapsulated in a small sealed container to ensure two means of preventing leakage, thereby allowing easy installation in any area of the aircraft (such as electrical, avionics, high voltage, and low voltage compartments).
[0010] The hybrid hydraulic / electrical braking control system of the embodiments disclosed herein now enables the electrical control of an aircraft's braking and parking brake applications with a relatively simple control box without relying on adjacent resources or systems such as a hydraulic generation system, a cable and pulley system, valves, etc. The hybrid hydraulic / electrical braking control system of the embodiments disclosed herein can also be suitably installed in almost any airborne environment of the aircraft, such as in an area of the aircraft that is incompatible with combustible fuel.
[0011] These and other aspects and advantages of the present invention will become more apparent after a careful consideration of the following detailed description of the preferred exemplary embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The disclosed embodiments of the present invention will be better and more fully understood from the following detailed description of exemplary non - limiting illustrative embodiments in conjunction with the accompanying drawings, in which:
[0013] Figure 1 is a schematic x - ray plan view of an aircraft equipped with a hybrid hydraulic / electrical braking control system according to an embodiment of the present invention;
[0014] Figure 2 is an enlarged schematic x - ray plan view of an on - board hydraulic / electrical control assembly that can be employed in the aircraft depicted in Figure 1 ; and
[0015] Figure 3 is a sectional elevation view of a port - side brake channel unit taken along line 3 - 3 in Figure 2 . DETAILED DESCRIPTION
[0016] An aircraft AC including a hybrid hydraulic / electrical braking control system 10 according to an embodiment of the present invention is depicted in the attached Figure 1 as a schematic x - ray plan view. As shown, the aircraft AC conventionally includes a port - side wing Wp and a starboard - side wing Ws along with a tricycle landing gear arrangement, which consists of a nose - wheel assembly NW and port - side main - wheel assemblies MWp and starboard - side main - wheel assemblies MWs, respectively. The nose - wheel assembly NW can freely caster (i.e., without any mechanical or electrical interconnection for steering), while the port - side main - wheel assembly MWp and the starboard - side main - wheel assembly MWs are operatively hydraulically interconnected via a port - side hydraulic line HLp and a starboard - side hydraulic line HLs to a port - side brake channel unit 12 and a starboard - side brake channel unit 14 associated with the hybrid hydraulic / electrical braking control system 10, respectively.
[0017] The attached Figure 2 and Figure 3 are enlarged views of the hybrid hydraulic / electrical braking control system 10, where Figure 2 is its schematic X - ray plan view, Figure 3It is a side elevation view of the port brake channel unit 12. As shown, each of the port brake channel unit 12 and the starboard brake channel unit 14 includes an electro-mechanical actuator unit 16, 18 which are operatively interconnected to the brake master cylinders 20, 22 respectively via actuator rods 24a, 26a associated with the linear actuators 24, 26 of the electro-mechanical actuator units 16, 18. The linear actuators 24, 26 of the electro-mechanical actuator units 16, 18 receive brake actuation signals from the control drive units 28, 30. Thus, the actuator units will convert the brake actuation signals into mechanical linear translations of the control rods 24a, 26a so as to in turn apply a braking control force to the port main wheel assembly MWp and the starboard main wheel assembly MWs by means of regulated hydraulic pressures in the hydraulic lines HLp, HLs which are respectively proportional to the brake actuation signals.
[0018] Each of the control drive units 28, 30 is operatively communicable with an on-board controller 40 which in turn receives signal inputs from the port side brake control 42 and the starboard side brake control 44 respectively. In this regard, if the aircraft AC is manned, the port side brake control 42 and the starboard side brake control 44 may be in the form of conventional pedal brake controls or hand brake control switches. However, if the aircraft is unmanned, the on-board controller 40 will wirelessly receive control signals from a remote controller 50 which may be ground or air based. In response to receiving a control signal (e.g., from the port side brake control 42 and / or the starboard side brake control 44, or from the remote controller 50), the on-board controller 40 will issue command signals to the respective control drive units 28, 30 so as to activate the linear actuators 24, 26 which in turn linearly move the actuator rods 24a, 26b. The actuator rods 24a, 26a will in response linearly move the associated cylinder plungers 20a, 22a (associated with the brake master cylinders 20, 22), thereby applying hydraulic pressure via the hydraulic lines HLp, HLs to the port side main wheel assembly MWp and / or the starboard side main wheel assembly MWs, thus causing the desired symmetric or asymmetric braking action to occur. In the case of a desired parking brake function, the on-board controller 40 may issue command signals such that each of the respective control drive units 28, 30 causes the normally closed (NC) solenoid valves 52, 54 to close, thereby creating a hydraulic pressure lock when the master cylinders 20, 22 are fully actuated (e.g., maximum hydraulic braking force is applied). Alternatively or additionally, the hydraulic pressure lock may be achieved by activating an internal locking device associated with the electro-mechanical actuator units 16, 18. In this regard, when the control drive units 28, 30 operate to provide normal brake control as previously discussed, the NC solenoid valves will be signaled to open.
[0019] Each master brake cylinder 20, 22 is provided with a fluid reservoir 20b, 22b that contains a reservoir quantity of hydraulic fluid which supplies the respective master brake cylinders 20, 22 to compensate for natural fluid losses (e.g., leakage and / or thermal variations). Floating level sensors 20c, 22c are disposed within each reservoir 20b, 22b to provide a low hydraulic fluid level signal to the control drive units 28, 30 and thus to the on-board controller 40. Such a signal can then be used to provide a visual notification of the low level hydraulic fluid condition.
[0020] Pressure transducers 20d, 22d are also operatively associated with each master brake cylinder 20, 22 respectively, which provide hydraulic pressure feedback signals to the control drive units 28, 30 respectively. The hydraulic pressure feedback signals thereby allow the control drive units 28, 30 to adjust the linear actuators 24, 26, thus ensuring that appropriate hydraulic pressure is applied by the master brake cylinders 20, 22 via hydraulic lines HLp, HLs to the port side main wheel assembly MWp and the starboard side main wheel assembly MWs respectively.
[0021] The port brake channel unit 12 and the starboard brake channel unit 14 can be incorporated within a fully sealed leak-proof housing 60 that prevents leakage of hydraulic fluid (should a hydraulic fluid leak occur). To ensure that the hybrid hydraulic / electrical brake control system 10 can be positioned in almost any location permitted by the space within the aircraft AC, pre-pressurized springs are provided within the hydraulic reservoirs 20b, 22b. By way of example, Figure 3 FIG. schematically shows a spring 20d between a reservoir cap 20e and a fluid piston 20f located within the hydraulic reservoir 20b. The reservoir cap 20e, the spring 20d, and the fluid piston 20f are assembled as a single unit such that when the cap 20e is removed, the spring 20d and the piston 20f are removed together. When the hydraulic reservoir 20b is capped by this unit, the capping method will compress the spring, thus pre-pressurizing the hydraulic fluid through the fluid piston 20f. A similar arrangement can be provided for the hydraulic reservoir 22b. The housing 60 can also include a bottom tray 60a that will help prevent leakage of hydraulic fluid (should a hydraulic fluid leak occur).
[0022] While the present invention has been described herein with reference to specific embodiments thereof, various modifications within the skill of the art can be envisioned. Accordingly, it is to be understood that the invention is not limited to the disclosed embodiments, but rather is intended to cover various modifications and equivalent arrangements included within its spirit and scope.
Claims
1. A hybrid hydraulic / electrical braking control system for an aircraft, comprising: A port side braking channel unit; And A starboard side braking channel unit, wherein The port side braking channel unit and the starboard side braking channel unit are configured to provide independent braking control to a port side main wheel assembly and a starboard side main wheel assembly associated with the aircraft, and wherein Each of the port side braking channel unit and the starboard side braking channel unit includes: (i) A main brake cylinder for providing hydraulic braking pressure to a respective one of the port side main wheel assembly and the starboard side main wheel assembly associated with the aircraft through a port side hydraulic line and a starboard side hydraulic line, respectively; (ii) A control drive unit configured to output a brake actuation signal; and (iii) A linear actuator operably electrically communicating with the control drive unit, and the linear actuator includes an actuator rod mechanically connected to the main brake cylinder, the linear actuator being configured to receive the brake actuation signal from the control drive unit and convert the brake actuation signal into a mechanical translation of the actuator rod, thereby causing the main brake cylinder to provide a proportional hydraulic braking force to a respective one of the port side main wheel assembly and the starboard side main wheel assembly.
2. The hybrid hydraulic / electrical braking control system according to claim 1, wherein, The main brake cylinder of each of the port side braking channel unit and the starboard side braking channel unit includes a spring-loaded fluid reservoir fluidly connected to the main brake cylinder.
3. The hybrid hydraulic / electrical braking control system according to claim 2, wherein, The spring-loaded fluid reservoir includes a float switch that emits a hydraulic fluid level signal received by the control drive unit.
4. The hybrid hydraulic / electrical braking control system according to claim 1, further comprising a pressure transducer fluidly communicating with the main brake cylinder, the pressure transducer emitting a hydraulic pressure feedback signal to the control drive unit.
5. The hybrid hydraulic / electrical braking control system according to claim 1, further comprising a leak-proof housing that completely encloses the port side braking channel unit and the starboard side braking channel unit.
6. The hybrid hydraulic / electrical braking control system according to claim 5, wherein, The housing includes a bottom tray for receiving hydraulic fluid leakage from the main brake cylinder.
7. An aircraft, comprising: A port side main wheel assembly and a starboard side main wheel assembly, the port side main wheel assembly and the starboard side main wheel assembly including respective braking systems; And The hybrid hydraulic / electrical braking control system according to claim 1, wherein The main brake cylinder of each of the port side braking channel unit and the starboard side braking channel unit is operably connected to a respective one of the braking systems of the port side main wheel assembly and the starboard side main wheel assembly through the port side hydraulic line and the starboard side hydraulic line, respectively.
8. The aircraft according to claim 7, wherein, The main brake cylinder of each of the port side braking channel unit and the starboard side braking channel unit includes a fluid reservoir fluidly connected to the main brake cylinder.
9. The aircraft according to claim 8, wherein, The fluid reservoir includes a float switch that emits a hydraulic fluid level signal received by the control drive unit.
10. The aircraft according to claim 7 further includes a pressure transducer fluidly connected to the master brake cylinder, and the pressure transducer sends a hydraulic pressure feedback signal to the control drive unit.
11. The aircraft according to claim 7 further includes a leak-proof housing that completely surrounds the port brake channel unit and the starboard brake channel unit.
12. The aircraft according to claim 11, wherein, The housing includes a bottom tray for receiving hydraulic fluid leakage from the master brake cylinder.
13. The aircraft according to claim 7 further includes: manually operable port and starboard brake controls on board, the port and starboard brake controls sending corresponding port and starboard brake control signals; and an on-board controller that receives the port and starboard brake control signals from the manually operable port and starboard brake controls and sends corresponding command signals to the port control drive unit and the starboard control drive unit respectively.
14. The aircraft according to claim 7 further includes an on-board controller that wirelessly receives port and starboard brake control signals from a remote controller and, in response, sends corresponding command signals to the port control drive unit and the starboard control drive unit.