A drone brake system architecture and brake control method

Abstract

The application relates to a kind of unmanned aerial vehicle brake system architecture and brake control method, belong to aircraft brake system technical field.The system architecture includes the main brake system, the auxiliary brake system and the emergency brake system arranged in parallel, forms three redundant brake channel architecture.Each redundancy works independently, any redundancy in three redundant brake channels can work, that is, it can ensure the normal work of unmanned aerial vehicle brake system, and the control board of three channel brake systems monitors the health state independently and mutually, ensures the safety of aircraft brake.The unmanned aerial vehicle brake system architecture cancels the monitoring board design, introduces the active intervention and anti-skid function of emergency brake, solves the problems of monitoring board single point failure in existing brake system architecture, emergency brake without active anti-skid and fault detection reporting.

Description

Technical Field

[0001] This invention relates to the field of aircraft braking system technology, specifically to a braking system architecture and braking control method for unmanned aerial vehicles (UAVs). Background Technology

[0002] The aircraft braking system is a critical system during takeoff and landing, and one of the most important systems affecting aircraft safety. Older aircraft used only a single-redundant system control, resulting in low safety margins. With advancements in technology, most aircraft braking systems now employ a dual-redundant design with both normal and emergency braking. This means the aircraft braking system consists of a normal braking system and an emergency braking system. The normal braking system typically includes a main braking system and a backup braking system, while the emergency braking system requires a separate emergency lever. The normal and emergency braking systems operate independently. Under normal circumstances, the pilot sends braking command signals through the brake pedal in the normal braking system or via communication or other means. After a series of software calculations, braking pressure is output to apply the braking force. Typically, if the normal braking fails or becomes inoperable, the pilot can use the emergency braking system to bring the aircraft to a stop and ensure safety.

[0003] In the traditional aircraft braking system architecture that includes normal braking and emergency braking, such as Figure 1 The normal braking system, as shown, utilizes a main control board and a secondary control board to achieve electrical redundancy. The main control board controls the primary braking system, while the secondary control board controls the backup braking system. A monitoring board controls both the main and secondary control boards. For pilot-operated aircraft, emergency braking requires manual operation of the brake lever. For UAVs, the manual brake lever is replaced with motor-controlled emergency brake buttons or levers operated via a ground station. In this brake controller architecture with main and secondary control boards, the main and secondary control boards only acquire and process analog quantities (such as speed and brake pressure) and discrete quantities (such as wheel load signals), as well as control anti-skid and braking. During anti-skid braking control, the monitoring board monitors the status of the control boards to determine their braking capability and perform redundancy switching to ensure braking safety. The monitoring board's main functions include: system status monitoring and fault management, communication protocol management, and dual-redundancy design and switching.

[0004] The drawbacks of the above-mentioned aircraft braking system architecture are as follows: 1. The control arbitration signals sent to the main control board and the secondary control board are issued by the monitoring board. If the monitoring board is faulty, the switching between the main brake and the backup brake cannot be performed, and only the main brake system can be used. If the main brake system fails, it may lead to brake failure; 2. For UAVs, the emergency brake only changes the manual brake handle to motor control, and manual operation is still required to perform the emergency brake. The emergency brake does not have functions such as automatic intervention braking control, active anti-skid, fault detection and fault reporting.

[0005] Therefore, there is a need to provide an architecture for a drone braking system and a braking control method to solve the above problems. Summary of the Invention

[0006] The technical problem to be solved: To overcome the shortcomings of existing technologies, this invention provides a UAV braking system architecture and braking control method. It integrates control and monitoring functions into a single functional board, eliminating the need for a separate monitoring board. This results in a triple-redundant braking channel design with three independently controlled control boards. The normal operation of the braking system is guaranteed as long as any one of the triple-redundant braking channels is functional. Furthermore, the three control boards monitor each other's health status to ensure braking safety. This invention solves the problems of single-point failure of the monitoring board and the lack of active anti-skid and fault detection reporting in existing braking system architectures.

[0007] The technical solution of the present invention is: a braking system architecture for unmanned aerial vehicles, including a main braking system, a secondary braking system and an emergency braking system; The main braking system is used to receive braking commands from the host computer and control the aircraft braking. The secondary braking system has the same structure as the main braking system. As a backup system for the main braking system, the secondary braking system is used to control the aircraft braking according to the braking command from the host computer when the main braking system fails. The emergency braking system is used to control the aircraft braking according to the braking command from the host computer after the main braking system and the auxiliary braking system fail; the emergency braking system is also used to directly receive emergency braking commands from the host computer to control the aircraft braking and to perform intermittent pulse anti-skid braking. The main braking system, auxiliary braking system, and emergency braking system are all electrically connected to the host computer to receive braking commands from the host computer; the main braking system, auxiliary braking system, and emergency braking system are electrically connected to each other for self-monitoring and mutual monitoring of their health status.

[0008] A further technical solution of the present invention is: the main braking system includes a main control board, a main brake valve, a wheel speed sensor, and a pressure sensor; The secondary braking system includes a secondary control board, a secondary brake valve, a wheel speed sensor, and a pressure sensor; The emergency braking system includes an emergency control board, a setpoint pressure reducing valve, wheel speed sensors, and pressure sensors; Among them, the three braking systems share wheel speed sensors and pressure sensors, the three control boards constitute the brake controller, and the set value pressure reducing valve in the emergency braking system is integrated into the auxiliary brake valve. The main control board is used to receive braking commands from the host computer and convert them into main braking signals to send to the main braking valve; the main braking valve is used to convert the main braking signals into braking pressure to control the brakes. The secondary control board is used to receive braking commands from the host computer and convert them into secondary braking signals, which are then sent to the secondary braking valve. The secondary braking valve is used to convert the secondary braking signals into braking pressure to control the brakes. The emergency control board is used to receive braking commands from the host computer and convert them into emergency braking signals to send to the setpoint pressure reducing valve; the setpoint pressure reducing valve is used to convert the emergency braking signal into a setpoint braking pressure to control the braking. Wheel speed sensors are used to detect wheel speed and feed the results back to the brake controller for processing. Pressure sensors are used to detect the brake pressure output downstream of the main brake valve and the auxiliary brake valve and feed the results back to the brake controller for processing.

[0009] A further technical solution of the present invention is as follows: the main control board, the secondary control board and the emergency control board are connected to each other via an RS422 bus, and the main control board, the secondary control board and the emergency control board are all connected to the host computer via an RS422 bus; the main control board, the secondary control board and the emergency control board all have built-in brake control software.

[0010] A further technical solution of the present invention is: the built-in software of the main control board, the secondary control board and the emergency control board is set to self-monitor the health status of the braking system in which they are located and to mutually monitor the health status of each braking system. When the braking system currently holding braking control fails, the control is handed over to the other healthy braking system.

[0011] A further technical solution of the present invention is: the main control chip of the main control board, the auxiliary control board and the emergency control board is used to output the braking signal of their respective braking systems through logical calculation based on the braking command of the host computer, the braking pressure fed back by the pressure sensor and the wheel speed fed back by the wheel speed sensor.

[0012] A further technical solution of the present invention is as follows: the main brake valve is installed in the landing gear bay, and the main brake valve includes a first electromagnetic hydraulic lock and two first servo valves; the first electromagnetic hydraulic lock is electrically connected to the main control board and is used to control the on / off of the brake hydraulic oil circuit; both first servo valves are electrically connected to the main control board, and the first servo valves are used to receive the brake current signal from the main control board and convert it into brake pressure to control the wheel brakes, and the two first servo valves respectively control the left wheel and the right wheel.

[0013] A further technical solution of the present invention is as follows: the auxiliary brake valve is installed in the landing gear bay, and the auxiliary brake valve includes a second electromagnetic hydraulic lock, two second servo valves, and a setpoint pressure reducing valve; the second electromagnetic hydraulic lock is electrically connected to the auxiliary control board and is used to control the on / off of the brake hydraulic oil circuit; both second servo valves are electrically connected to the auxiliary control board, and the second servo valves are used to receive the brake current signal from the auxiliary control board and convert it into brake pressure to control the wheel brakes, and the two second servo valves respectively control the left wheel and the right wheel; the setpoint pressure reducing valve is independent of the other components in the auxiliary brake valve, and the setpoint pressure reducing valve is electrically connected to the emergency control board, and a relay is connected in series in the circuit between the setpoint pressure reducing valve and the emergency control board, the relay is used to control the opening and closing of the setpoint pressure reducing valve, and the setpoint pressure reducing valve is used to convert the emergency brake signal into a setpoint brake pressure to control the left wheel and the right wheel brakes.

[0014] A braking control method employing the aforementioned UAV braking system architecture, the method comprising: The host computer sends a braking command to the controller. After receiving a braking command, the controller assesses the health status of the main braking system, the auxiliary braking system, and the emergency braking system, and assigns braking control to the healthy braking system. By default, the main braking system performs braking. When the main braking system fails, the auxiliary braking system responds. When both the main and auxiliary braking systems fail, or when the host computer issues an emergency braking command, the emergency braking system performs braking. The health status of each braking system is reported to the host computer. When the main braking system performs braking, the main control board performs logical calculations based on the braking command from the host computer, the wheel speed information fed back by the wheel speed sensor, and the pressure information fed back by the pressure sensor. It then outputs a main braking signal to the main braking valve through its built-in software, and the main braking valve outputs braking pressure to perform braking. When the auxiliary braking system performs braking, the braking command from the host computer of the auxiliary control board, the wheel speed information fed back by the wheel speed sensor, and the pressure information fed back by the pressure sensor are logically calculated by its built-in software and the auxiliary braking signal is sent to the auxiliary braking valve. The auxiliary braking valve then outputs braking pressure to perform braking. When the emergency braking system applies the brakes, the emergency control board controls the relay to turn on, inputting a 28V emergency control electrical signal to the setpoint pressure reducing valve, which then controls the setpoint pressure reducing valve to output a setpoint braking pressure to apply the brakes.

[0015] A further technical solution of the present invention is: the logic for health determination is set such that if the braking system currently performing braking control malfunctions, the current health status is determined by the current task control board. If the malfunction does not affect braking and anti-skid, the current malfunction status is retained and braking operation continues. If a malfunction affecting braking and anti-skid occurs, redundancy switching is performed.

[0016] A further technical solution of the present invention is: when the emergency braking system detects an abnormal wheel speed signal, it controls the relay to conduct intermittently through the emergency control board, so that the set value pressure reducing valve intermittently outputs braking pressure to achieve pulse-type active anti-skid braking.

[0017] The beneficial effects of this invention are as follows: This invention provides a UAV braking system architecture that eliminates the monitoring board found in traditional aircraft braking systems. Instead, it employs three parallel control boards to form the controller for the UAV braking system. Each control board controls one braking system path, achieving a triple-redundancy design. The three parallel control boards communicate with the host computer and receive braking commands from the host computer in parallel, thereby avoiding single-point failures caused by monitoring board malfunctions that would prevent the switching between primary and backup braking.

[0018] In this invention, the main control board, secondary control board, and emergency control board are connected in pairs via an RS422 bus, and then communicate with the host computer software to perform self-monitoring and mutual monitoring of their health status. Finally, the fault status is determined by a comprehensive analysis. Compared to the traditional method of detecting faults in itself and the control board through a monitoring board, this design allows the control board to monitor its own health status while simultaneously monitoring the health status of another redundant board, significantly improving the fault detection rate.

[0019] This invention fully utilizes a health management model, retaining the current fault state and continuing braking operations when it does not affect braking and anti-skid functions. This maximizes the redundancy of the braking system. Furthermore, each braking system identifies itself through its own control board's position identification signal and function, and determines whether to maintain control output or relinquish control through its software's control decision function. Compared to traditional vehicle systems that switch over immediately upon detecting a fault without considering their own state to continue braking operations, this invention maximizes system redundancy, improves system reliability, and avoids the primary / backup dual-output problem of traditional braking systems.

[0020] This invention controls the relay setpoint pressure reducing valve through an emergency control board. When the main and backup brakes (i.e., the auxiliary brake system) fail, the emergency brake automatically intervenes. Furthermore, by intermittently controlling the relay to open and close, it achieves on-off anti-skid control, which is more in line with the usage requirements of UAVs. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1This is a schematic diagram of the architecture of an existing traditional aircraft braking system; Figure 2 This is a schematic diagram of the brake controller structure consisting of three control boards in the UAV braking system architecture of the present invention; Figure 3 This is a schematic diagram of the software architecture in the UAV braking system architecture of the present invention; Figure 4 This is a simplified schematic diagram of the UAV braking system architecture of the present invention; Figure 5 This is a system framework diagram of the UAV braking system architecture of the present invention; Figure 6 This is a schematic diagram of the pulse output of the pulse-type active anti-skid braking system during emergency braking according to the present invention. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] An embodiment of the drone braking system architecture of the present invention, such as Figures 2-6 As shown, the system includes a main braking system, a secondary braking system, and an emergency braking system, forming a triple-redundant parallel braking channel. As long as any one of the braking channels functions properly, the drone can brake normally. This invention solves the stability and safety problems of dual-redundant braking systems, providing a highly reliable triple-redundant drone braking system.

[0025] The main braking system receives braking commands from the host computer and controls the aircraft's braking. The secondary braking system has the same structure as the main braking control system and serves as a backup. In the event of a failure in the main braking control system, the secondary braking system controls the aircraft's braking according to the host computer's braking commands. The emergency braking system controls the aircraft's braking according to the host computer's braking commands after a failure in both the main and secondary braking systems, or when the host computer requests emergency braking. The emergency braking system also functions as an intermittent pulse anti-skid braking system.

[0026] The main braking system includes a main control board, a main brake valve, wheel speed sensors, and pressure sensors; the secondary braking system includes a secondary control board, a secondary brake valve, wheel speed sensors, and pressure sensors; and the emergency braking system includes an emergency control board, a setpoint pressure reducing valve, wheel speed sensors, and pressure sensors. The three control boards of the main braking system, secondary braking system, and emergency braking system constitute the brake controller of the entire UAV braking system architecture, acting as the control core to implement braking control. The brake controller receives braking commands from the host computer. The main and secondary brake valves, as well as the setpoint pressure reducing valve, are used to convert the electrical signals from their respective control boards into braking pressure to control the wheel brakes. The setpoint pressure reducing valve is integrated within the secondary brake valve. The main braking system, secondary braking system, and emergency braking system share wheel speed sensors and pressure sensors. The wheel speed sensors monitor and transmit wheel speed signals, converting them into approximately sinusoidal signals that are transmitted to the brake controller (i.e., the three control boards) for processing. In this embodiment, two wheel speed sensors are provided, installed on the left and right wheels respectively. Pressure sensors are used to detect the brake pressure output downstream of the main brake valve and the auxiliary brake valve, and feed it back to the brake controller for processing. In this embodiment, there are four pressure sensors: two are installed in the hydraulic circuit downstream of the main brake valve to measure the brake pressure output by the main brake valve to the left and right wheels, respectively; the other two are installed in the hydraulic circuit downstream of the auxiliary brake valve to measure the brake pressure output by the auxiliary brake valve to the left and right wheels, respectively. To improve operational stability, the sensors in this embodiment employ electrical redundancy.

[0027] Specifically, such as Figure 4 , Figure 5 As shown, the main control board is electrically connected to the host computer. It is used to receive the braking command from the host computer and convert it into a main braking signal to send to the main braking valve. The main braking valve is used to convert the main braking signal into braking pressure to control the braking of the left and right wheels.

[0028] The main control board is the BCU control board, whose main control core has built-in brake control software. It can output a brake signal to the main brake valve through logic calculation based on the brake command from the host computer, the brake pressure fed back by the pressure sensor, and the wheel speed fed back by the wheel speed sensor.

[0029] The main brake valve is installed in the landing gear bay and includes a first electromagnetic hydraulic lock and two first servo valves. The first electromagnetic hydraulic lock is electrically connected to the main control board and is used to control the on / off of the brake hydraulic circuit according to the output signal of the main control board. The two first servo valves are connected in parallel and in series downstream of the first electromagnetic hydraulic lock. Both first servo valves are also electrically connected to the main control board. The first servo valves are used to receive the brake current signal from the main control board and convert it into brake pressure to control the wheel brakes. The two first servo valves control the left and right wheels respectively.

[0030] The secondary control board is electrically connected to the host computer. It is used to receive the braking command from the host computer and convert it into a secondary braking signal, which is then sent to the secondary brake valve. The secondary brake valve is used to convert the secondary braking signal into braking pressure to control the braking of the left and right wheels.

[0031] The secondary control board is the BCU control board, whose main control core has built-in brake control software. It can output a brake signal to the secondary brake valve through logic calculation based on the brake command from the host computer, the brake pressure fed back by the pressure sensor, and the wheel speed fed back by the wheel speed sensor.

[0032] The secondary brake valve is installed in the landing gear bay and includes a second electromagnetic hydraulic lock, two second servo valves, and a setpoint pressure reducing valve. The second electromagnetic hydraulic lock is electrically connected to the secondary control board and controls the on / off of the brake hydraulic circuit based on the output signal from the secondary control board. The two second servo valves are connected in parallel and in series downstream of the second electromagnetic hydraulic lock, and both are electrically connected to the secondary control board. The second servo valves receive the brake current signal from the secondary control board and convert it into brake pressure to control the wheel brakes. The two second servo valves control the left and right wheels respectively.

[0033] The emergency control board is electrically connected to the host computer. It is used to receive the braking command from the host computer and convert it into an emergency braking signal to send to the setpoint pressure reducing valve. The setpoint pressure reducing valve is used to convert the emergency braking signal into a setpoint braking pressure to control the braking.

[0034] The emergency control board is a BCU control board. Its main control core has built-in brake control software, which can realize the output of emergency braking signal through logic calculation based on the brake command from the host computer, the brake pressure fed back by the pressure sensor and the wheel speed fed back by the wheel speed sensor. The relay switch control signal makes the relay conduct 28V power to the fixed value pressure reducing valve in the auxiliary brake valve to realize the on and off of emergency braking signal transmission.

[0035] The pressure reducing valve is integrated into the auxiliary brake valve and is independent of the other components in the auxiliary brake valve. The pressure reducing valve is electrically connected to the emergency control board. A relay is connected in series in the circuit between the pressure reducing valve and the emergency control board. The relay is used to control the conduction and disconnection of the 28V power supply, thereby controlling the opening and closing of the pressure reducing valve. The pressure reducing valve is used to convert the emergency brake signal into a fixed brake pressure to control the brakes of the left and right wheels.

[0036] The main control board, secondary control board, and emergency control board are connected in pairs via RS422 bus. All three boards are also connected to the host computer via RS422 bus, enabling the integration of built-in brake control software on the main control board, secondary control board, and emergency control board with the host computer's software system. Figure 3 The software network architecture shown.

[0037] Based on the communication connection between the main control board, the secondary control board, and the emergency control board, health management and data reconstruction are adopted to enable the three redundancies to perform self-monitoring and mutual monitoring voting respectively. That is, the built-in software of the main control board, the secondary control board, and the emergency control board is set to self-monitor the health status of the braking system where it is located and to mutually monitor the health status of each braking system. When the braking system currently holding braking control fails, the control is handed over to the other healthy braking system.

[0038] The switching logic is primary-secondary-emergency. Under normal circumstances, the system defaults to primary braking, meaning the main control board responds and outputs braking current to control the main brake valve for braking and anti-skid control after considering the current status. The secondary braking system does not output anything. When the primary braking system fails, the secondary braking system responds and outputs a braking control signal. Both the primary and secondary braking systems operate under normal braking conditions. When both the primary and secondary braking systems fail, or when the host computer issues an emergency braking command, the emergency braking system takes over.

[0039] Each control board reports its current health status to the host computer. Simultaneously, to maximize the redundancy of the braking system, the health determination logic is configured as follows: if a fault occurs in the braking system currently performing braking control, the current task control board determines the current health status. If the fault does not affect braking and anti-skid operation, the current fault status is retained, and braking operations continue. If a fault affecting braking and anti-skid operation occurs, a healthier channel is selected for redundancy switching. To this end, a fault level table (Table 1) is established to evaluate the fault level of each braking channel to assess its health status. Each channel monitors its own health status while also monitoring the health status of another channel, and the final fault status is determined after comprehensive evaluation.

[0040] Table 1 Fault Level Table

[0041] The entire system distinguishes the three control boards through the hardware circuit in the controller. By collecting the machine position identification signal, the system uses the machine position identification function in the software to identify itself as the main / secondary / emergency control board. Through the control authority decision function in the software, the system determines whether to control the output, thus avoiding the problem of main / backup dual output in the original braking system.

[0042] The emergency braking system of this invention features automatic switching, automatic anti-skid, and fault detection functions. The emergency control board responds to normal and emergency braking commands sent from the host computer.

[0043] When an emergency traction braking command (or command ≥ 4.5MPa) sent by the host computer needs to be executed, the emergency control board responds and controls the emergency brake relay to conduct, thereby causing the set pressure reducing valve in the auxiliary brake valve to work and output a set pressure for emergency traction braking.

[0044] When both the main braking system and the auxiliary braking system fail, the system will automatically switch to the emergency braking system for braking.

[0045] When the drone operator performs a braking operation and the braking pressure is greater than or equal to the emergency braking setpoint pressure, the emergency brake automatically responds and takes over the output; when the braking pressure of the drone operator's braking operation is less than the emergency braking setpoint pressure, the drone switches to emergency brake and does not output pressure. It can only output pressure when an emergency brake command is sent or a braking operation with a pressure greater than or equal to the emergency brake setpoint pressure is used.

[0046] When the wheel speed signal is normal, the emergency braking system can achieve two control modes: anti-slip and non-anti-slip. When anti-slip is not used, the emergency brake outputs a set pressure normally throughout the entire process; when anti-slip is used, the emergency brake performs pulse-type active anti-slip braking throughout the entire process, realizing on-off anti-slip control.

[0047] When the wheel speed signal is abnormal, the emergency braking system will perform pulse-type active anti-skid braking throughout the entire process.

[0048] Under normal braking conditions, the emergency braking system's pressure-reducing valve outputs a constant pressure. When the system determines that anti-skid function intervention is needed, it can directly control the 28V relay to shut down, thereby closing the pressure-reducing valve in the backup brake valve. See details... Figure 6 A 500ms braking time and a 500ms braking release time are used to achieve intermittent anti-skid control. The emergency braking command can override the normal braking command, directly switching to the emergency control board to respond to the emergency braking, ensuring that the emergency braking is responded to and improving the safety of the drone.

[0049] When the UAV braking system of this invention is used in practice, the braking control method is as follows: The host computer sends a braking command to the controller. Upon receiving the command, the controller assesses the health status of the main braking system, the auxiliary braking system, and the emergency braking system, and assigns braking control to the healthy braking system. The main braking system is the default; if it fails, the auxiliary braking system responds; if both fail, or if the host computer issues an emergency braking command, the emergency braking system takes over. The health status of each braking system is reported to the host computer.

[0050] When the main braking system applies the brakes, the main control board, based on the braking command from the host computer, the wheel speed information fed back by the wheel speed sensor, and the pressure information fed back by the pressure sensor, performs logical calculations through its built-in software and outputs a main braking signal to the main brake valve. The main brake valve then converts the electrical signal from the main control board into a braking pressure output to control the braking of the left and right wheels.

[0051] When the main braking system fails and the auxiliary braking system performs braking, the auxiliary control board, based on the braking command from the host computer, the wheel speed information fed back by the wheel speed sensor, and the pressure information fed back by the pressure sensor, performs logical calculations through its built-in software and outputs an auxiliary braking signal to the auxiliary brake valve. The auxiliary brake valve converts the electrical signal from the auxiliary control board into a braking pressure output to control the braking of the left and right wheels.

[0052] When both the main and auxiliary braking systems fail, or when the host computer requests the emergency braking system to activate, the emergency braking system will engage. The emergency control board, based on the braking command from the host computer, controls the relay to conduct, inputting a 28V emergency control signal to the pressure reducing valve in the auxiliary brake valve. This pressure reducing valve then outputs a set braking pressure, achieving braking of the left and right wheels.

[0053] like Figure 6 As shown, when the emergency braking system detects an abnormal wheel speed signal, it controls the relay to conduct intermittently via the emergency control board, causing the setpoint pressure reducing valve to intermittently output braking pressure to perform pulse-type active anti-skid braking. Specifically, the emergency control board inputs a 28V electrical signal to the setpoint pressure reducing valve, and the relay intermittently switches the 28V electrical signal on and off to control the setpoint pressure reducing valve to intermittently output braking pressure, thereby achieving pulse-type active anti-skid braking.

[0054] This invention breaks away from the functional module division of the original brake controller architecture, integrates and optimizes redundant circuits on the control board, and removes some power detection circuits and discrete quantity acquisition circuits. While ensuring safety, it integrates control and monitoring functions into a single functional board, eliminating the monitoring board design and replacing it with a control board with equal redundancy. This achieves a triple-redundant braking channel including a main braking system, a secondary braking system, and an emergency braking system. By increasing control redundancy based on data exchange between control boards, and with each redundancy monitoring the health status of the others, it enables parallel control of each braking system via a host computer. Emergency braking is actively incorporated into the braking control, and through the design of relays and setpoint pressure reducing valves, pulse-type active anti-skid braking is achieved, improving the stability of UAV braking control. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A braking system architecture for unmanned aerial vehicles (UAVs), characterized in that: This includes the main braking system, the auxiliary braking system, and the emergency braking system; The main braking system is used to receive braking commands from the host computer and control the aircraft braking. The secondary braking system has the same structure as the main braking system. As a backup system for the main braking system, the secondary braking system is used to control the aircraft braking according to the braking command from the host computer when the main braking system fails. The emergency braking system is used to control the aircraft braking according to the braking command from the host computer after the main braking system and the auxiliary braking system fail; the emergency braking system is also used to directly receive emergency braking commands from the host computer to control the aircraft braking and to perform intermittent pulse anti-skid braking. The main braking system, auxiliary braking system, and emergency braking system are all electrically connected to the host computer to receive braking commands from the host computer; the main braking system, auxiliary braking system, and emergency braking system are electrically connected to each other for self-monitoring and mutual monitoring of their health status.

2. The UAV braking system architecture according to claim 1, characterized in that: The main braking system includes a main control board, a main brake valve, wheel speed sensors, and pressure sensors; The secondary braking system includes a secondary control board, a secondary brake valve, a wheel speed sensor, and a pressure sensor; The emergency braking system includes an emergency control board, a setpoint pressure reducing valve, wheel speed sensors, and pressure sensors; Among them, the three braking systems share wheel speed sensors and pressure sensors, the three control boards constitute the brake controller, and the set value pressure reducing valve in the emergency braking system is integrated into the auxiliary brake valve. The main control board is used to receive braking commands from the host computer and convert them into main braking signals to send to the main braking valve; the main braking valve is used to convert the main braking signals into braking pressure to control the brakes. The secondary control board is used to receive braking commands from the host computer and convert them into secondary braking signals, which are then sent to the secondary braking valve. The secondary braking valve is used to convert the secondary braking signals into braking pressure to control the brakes. The emergency control board is used to receive braking commands from the host computer and convert them into emergency braking signals to send to the setpoint pressure reducing valve; the setpoint pressure reducing valve is used to convert the emergency braking signal into a setpoint braking pressure to control the braking. Wheel speed sensors are used to detect wheel speed and feed the results back to the brake controller for processing. Pressure sensors are used to detect the brake pressure output downstream of the main brake valve and the auxiliary brake valve and feed the results back to the brake controller for processing.

3. The UAV braking system architecture according to claim 2, characterized in that: The main control board, the secondary control board, and the emergency control board are connected in pairs via an RS422 bus, and all three are connected to the host computer via an RS422 bus; each of the main control board, the secondary control board, and the emergency control board has built-in brake control software.

4. The UAV braking system architecture according to claim 3, characterized in that: The built-in software of the main control board, the secondary control board, and the emergency control board is set to monitor the health status of their respective braking systems and monitor the health status of each braking system. When a braking system that currently holds braking control fails, control is handed over to the other healthy braking system.

5. The UAV braking system architecture according to claim 3, characterized in that: The main control chips of the main control board, secondary control board, and emergency control board are used to output the braking signals of their respective braking systems through logical calculations based on the braking commands from the host computer, the braking pressure fed back by the pressure sensor, and the wheel speed fed back by the wheel speed sensor.

6. The UAV braking system architecture according to claim 2, characterized in that: The main brake valve is installed in the landing gear bay and includes a first electromagnetic hydraulic lock and two first servo valves. The first electromagnetic hydraulic lock is electrically connected to the main control board and is used to control the on / off of the brake hydraulic oil circuit. Both first servo valves are electrically connected to the main control board. The first servo valves are used to receive the brake current signal from the main control board and convert it into brake pressure to control the wheel brakes. The two first servo valves control the left wheel and the right wheel respectively.

7. The UAV braking system architecture according to claim 2, characterized in that: The auxiliary brake valve is installed in the landing gear bay and includes a second electromagnetic hydraulic lock, two second servo valves, and a setpoint pressure reducing valve. The second electromagnetic hydraulic lock is electrically connected to the auxiliary control board and is used to control the on / off state of the brake hydraulic circuit. Both second servo valves are electrically connected to the auxiliary control board and are used to receive brake current signals from the auxiliary control board and convert them into brake pressure to control the wheel brakes. The two second servo valves control the left and right wheels respectively. The setpoint pressure reducing valve is independent of the other components in the auxiliary brake valve and is electrically connected to the emergency control board. A relay is connected in series in the circuit between the setpoint pressure reducing valve and the emergency control board. The relay is used to control the opening and closing of the setpoint pressure reducing valve. The setpoint pressure reducing valve is used to convert the emergency brake signal into a setpoint brake pressure to control the left and right wheel brakes.

8. A braking control method employing the UAV braking system architecture described in any one of claims 2-7, characterized in that: The host computer sends a braking command to the controller. After receiving the braking command, the controller assesses the health status of the main braking system, the auxiliary braking system, and the emergency braking system, and then transfers braking control to the healthy braking system. The main braking system is used by default. When the main braking system fails, the secondary braking system responds. When both the main and secondary braking systems fail, or when the host computer issues an emergency braking command, the emergency braking system will take over. The health status of each braking system is reported to the host computer. When the main braking system performs braking, the main control board performs logical calculations based on the braking command from the host computer, the wheel speed information fed back by the wheel speed sensor, and the pressure information fed back by the pressure sensor, and then outputs the main braking signal to the main braking valve. The main braking valve then outputs braking pressure to perform braking. When the secondary braking system performs braking, the secondary control board performs logical calculations based on the braking command from the host computer, the wheel speed information fed back by the wheel speed sensor, and the pressure information fed back by the pressure sensor, and then outputs a secondary braking signal to the secondary braking valve. The secondary braking valve then outputs braking pressure to perform braking. When the emergency braking system applies the brakes, the emergency control board controls the relay to turn on, inputting a 28V emergency control electrical signal to the setpoint pressure reducing valve, which then controls the setpoint pressure reducing valve to output a setpoint braking pressure to apply the brakes.

9. The braking control method according to claim 8, characterized in that: The logic for health determination is set as follows: if the braking system currently performing braking control malfunctions, the current health status is determined through the current task control panel. If the malfunction does not affect braking and anti-skid, the current malfunction status is retained and braking operation continues. If a malfunction that affects braking and anti-skid occurs, redundancy switching is performed.

10. The braking control method according to claim 8, characterized in that: When the emergency braking system detects an abnormal wheel speed signal, it controls the relay to conduct intermittently through the emergency control board, causing the set value pressure reducing valve to output braking pressure intermittently, so as to achieve pulse-type active anti-skid braking.

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