On-satellite autonomous recovery method for non-resident fault induced by ion electric propulsion ignition

Abstract

The invention belongs to the technical field of spacecraft electric propulsion systems, and relates to an on-satellite autonomous recovery method for a non-resident fault induced by ion electric propulsion ignition, which comprises the following steps of: judging whether a fault occurring in an ignition process of an ion electric propulsion system is an ignition fault, if so, controlling the ion electric propulsion to start a discharge chamber ignition mode, and if not, starting the discharge chamber ignition mode; in the mode, after waiting for a first preset time t1, judging whether an ion electric propulsion acceleration current is within a preset range or not, if yes, successful autonomous recovery is achieved, ignition of ion electric propulsion is stopped, and after waiting for a third preset time t3, the ion electric propulsion is autonomously recovered to a normal ignition mode; otherwise, stopping ignition of the ion electric propulsion, waiting for a second preset time t2, and repeating the process for multiple times after the ion thruster is cooled.

Description

Technical Field

[0001] The present invention belongs to the technical field of spacecraft electric propulsion systems, and in particular relates to an on-board autonomous recovery method for non-resident faults induced by ion electric propulsion ignition, which is suitable for handling on-orbit faults of ion electric propulsion. Background Art

[0002] Ultra-low-orbit satellites (ULEO) experience low orbits, high atmospheric damping, and heavy satellite weight constraints. Traditional chemical propulsion systems cannot meet the total impulse requirements throughout their operational lifespan, necessitating the deployment of high-specific-impulse ion electric propulsion systems. During ion electric propulsion ignition, the operating voltage between the ion thruster's screen and accelerator grids reaches over 1000V, while the spacing between them is less than 1mm. Due to dust, sputtering deposits, and grid burrs, momentary short circuits between the screen and accelerator grids are unavoidable, a phenomenon known as sparking. Inter-grid sparking is an inherent characteristic of ion thrusters. When a spark occurs, ignition is typically halted to protect the satellite's power supply. For ultra-low-orbit satellites, due to the high atmospheric drag, ion electric propulsion systems must perform more than ten orbit control missions daily, each lasting 30 minutes to an hour. Most of these missions occur during the non-T&C arc. Existing ion electric propulsion systems, when a spark failure occurs on-orbit, shut down the system and halt ignition, awaiting ground intervention for troubleshooting and resolution. If the resolution is successful, ignition is resumed via ground-based remote control command injection.

[0003] In order to avoid the rapid decay of the orbit caused by the failure to restore ignition for a long time in the non-tracking arc segment after an ion electric propulsion system ignition failure occurs, it is necessary to realize on-board autonomous protection and recovery of ion electric propulsion ignition failures in ultra-low orbit satellites. Summary of the Invention

[0004] The technical problem solved by the present invention is: to overcome the shortcomings of the existing technology and propose an on-board autonomous recovery method for non-resident faults induced by ion electric propulsion ignition. When inter-grid ignition occurs in the non-tracking and control arc section of the ion electric propulsion, the on-board autonomous execution of the shutdown program is realized to protect the energy safety of the entire satellite. Then, normal ignition is restored through the on-board autonomous recovery method, ensuring that the satellite will not fail to perform the orbit maintenance mission in the non-tracking and control arc section due to the non-resident inter-grid ignition fault.

[0005] The solution to the technical problem provided by the present invention is: an on-board autonomous recovery method for a non-resident fault induced by ion electric propulsion ignition, the method comprising the following steps:

[0006] S1. Determine whether the fault occurring during the ignition process of the ion electric propulsion system is an ignition fault. If it is a non-ignition fault, then end the process. Otherwise, initialize the number of ignition fault self-recovery times N to 0 and proceed to step S2.

[0007] S2, the number of ignition failure self-recovery times N = N + 1, if N ≤ the set number of allowed self-recovery times N0, then execute step S3, otherwise, the ion electric propulsion stops ignition and the number of ignition failure self-recovery times is reset to zero;

[0008] S3, controlling the ion electric propulsion to start the discharge chamber ignition mode, and in this mode, waiting for a first preset time t1 before entering step S4;

[0009] S4. Determine whether the ion thruster acceleration current is within a preset range. If so, autonomous recovery is successful, the ion thruster stops ignition, the number of autonomous ignition failure recovery times is reset, and the process proceeds to step S5. Otherwise, the ion thruster stops ignition, waits for a second preset time t2 until the ion thruster cools down, and then returns to step S2.

[0010] S5. After waiting for a third preset time t3, the ion electric propulsion automatically recovers to the normal ignition mode.

[0011] Preferably, it is characterized in that the method for judging the ignition failure is:

[0012] Screen current I for ion electric propulsion b If the average value within a continuous preset time period exceeds k times the screen current rated value I0, the fault occurring during the ignition process of the ion electric propulsion system is considered to be an ignition fault; otherwise, the fault occurring during the ignition process of the ion electric propulsion system is considered to be a non-ignition fault; the value range of k is [2, 4].

[0013] Preferably, the preset time period is 50 us to 100 us.

[0014] Preferably, in the discharge chamber ignition mode, the two high-voltage power supplies, the screen power supply and the acceleration power supply, are in the off state, and the neutralizer touch-holding power supply, the cathode touch-holding power supply, and the anode power supply are normally turned on; in this mode, only plasma discharge is generated, there is no high-voltage accelerated ion beam, and no thrust is generated.

[0015] Preferably, in the normal ignition mode, the neutralizer holding power supply, cathode holding power supply, anode power supply, screen grid power supply and acceleration power supply are normally turned on; in this mode, there is a high-voltage accelerated ion beam to generate thrust.

[0016] Preferably, the value range of the first preset time t1 is [60min, 120min].

[0017] Preferably, the value range of the first preset time t2 is [30min, 60min].

[0018] Preferably, the value range of the third preset time t3 is [10min, 30min].

[0019] Preferably, the set value range of the allowed number of autonomous recovery times N0 is [1, 10].

[0020] Preferably, the preset range is [I1*90%, I1*110%], where I1 is a normal value of the acceleration current when there is no short circuit between gates.

[0021] The beneficial effects of the present invention compared with the prior art are:

[0022] (1) The present invention can recover the non-resident grid short-circuit fault of ion electric propulsion through the on-board autonomous recovery method, thereby avoiding the rapid orbit decay caused by the long-term failure to restore ignition after the grid-to-grid ignition fault occurs in the ion electric propulsion system of the ultra-low orbit satellite in the non-tracking arc segment.

[0023] (2) The present invention uses a method of entering the discharge chamber mode to achieve on-board autonomous recovery of ion electric propulsion non-resident ignition failures. No thrust is generated during the autonomous recovery process, thereby avoiding affecting the attitude and orbit of the satellite.

[0024] (3) The present invention determines the short-circuit state between gates by the acceleration current value of ion electric propulsion, and realizes the diagnosis of whether the gate sparking is a permanent fault without adding additional resources. The method is simple and reliable.

[0025] (4) In the autonomous ignition recovery process, the present invention limits the number of ignition recovery times to avoid permanent faults in the ion electric propulsion system, which would cause a dead cycle of “ignition-ignition failure” and result in loss of satellite energy and propellant. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is an on-board autonomous recovery method for non-resident faults induced by ion electric propulsion ignition according to an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the embodiments.

[0028] like Figure 1 As shown, in order to prevent the ultra-low-orbit satellite from rapid orbit decay due to the long-term non-tracking arc segment of the ion electric propulsion system not restoring ignition, the present invention proposes an on-board autonomous recovery method for non-resident faults induced by ion electric propulsion ignition, and recovers the non-resident gate short-circuit fault of the ion electric propulsion. The method includes the following steps:

[0029] S1. Determine whether the fault occurring during the ignition process of the ion electric propulsion system is an ignition fault. If it is a non-ignition fault, then end the process. Otherwise, initialize the number of ignition fault self-recovery times N to 0 and proceed to step S2.

[0030] Preferably, the method for determining ignition failure is:

[0031] Screen current I for ion electric propulsion b If the average value within a continuous preset time period exceeds k times the screen current rating I0, the fault occurring during the ion electric propulsion system ignition process is considered an ignition fault; otherwise, the fault occurring during the ion electric propulsion system ignition process is considered a non-ignition fault; the value of k ranges from [2, 4]. The preset time period is 50µs to 100µs.

[0032] S2, the number of ignition failure self-recovery times N = N + 1, if N ≤ the set number of allowed self-recovery times N0, then execute step S3, otherwise, the ion electric propulsion stops ignition and the number of ignition failure self-recovery times is reset to zero;

[0033] The set value range of the allowed number of autonomous recovery times N0 is [1, 10].

[0034] S3, controlling the ion electric propulsion to start the discharge chamber ignition mode, and in this mode, waiting for a first preset time t1 before entering step S4;

[0035] In the discharge chamber ignition mode, the two high-voltage power supplies, the screen grid power supply and the acceleration power supply, are in the off state, and the neutralizer touch-holding power supply, the cathode touch-holding power supply, and the anode power supply are normally turned on; in this mode, only plasma discharge is generated, no high-voltage accelerated ion beam is generated, and no thrust is generated.

[0036] The value range of the first preset time t1 is [60min, 120min].

[0037] S4. Determine whether the ion thruster acceleration current is within a preset range. If so, autonomous recovery is successful, the ion thruster stops ignition, the number of autonomous ignition failure recovery times is reset, and the process proceeds to step S5. Otherwise, the ion thruster stops ignition, waits for a second preset time t2 until the ion thruster cools down, and then returns to step S2.

[0038] The value range of the second preset time t2 is [30min, 60min].

[0039] The preset range is [I1*90%, I1*110%], where I1 is a normal value of the acceleration current when there is no short circuit between gates.

[0040] The inter-gate short-circuit state is judged by the acceleration current value of ion electric propulsion. Without adding additional resources, the diagnosis of whether the gate sparking is a permanent fault is achieved. The method is simple and reliable.

[0041] S5. After waiting for a third preset time t3, the ion electric propulsion automatically recovers to the normal ignition mode.

[0042] In the normal ignition mode, the neutralizer holding power supply, cathode holding power supply, anode power supply, screen grid power supply and acceleration power supply are normally turned on; in this mode, there is a high-voltage accelerated ion beam to generate thrust.

[0043] The value range of the third preset time t3 is [10min, 30min].

[0044] In summary, the present invention utilizes a method of entering discharge chamber mode to achieve onboard autonomous recovery of non-resident ion propulsion ignition failures. This autonomous recovery process generates no thrust, thus preventing impacts on the satellite's attitude and orbit. Furthermore, the present invention limits the number of recovery ignitions during the autonomous recovery ignition process, preventing the ion propulsion system from entering an "ignition-failure" cycle due to resident failures, which could lead to loss of satellite energy and propellant.

[0045] Although the present invention has been disclosed above in terms of preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solutions of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the scope of protection of the technical solutions of the present invention.

Claims

1. An onboard autonomous recovery method for non-resident faults induced by ion electric propulsion ignition, characterized in that The steps include: S1. Determine whether the fault occurring during the ignition process of the ion electric propulsion system is an ignition fault. If it is a non-ignition fault, then end the process. Otherwise, initialize the number of ignition fault self-recovery times N to 0 and proceed to step S2. S2, the number of ignition failure self-recovery times N = N + 1, if N ≤ the set number of allowed self-recovery times N0, then execute step S3, otherwise, the ion electric propulsion stops ignition and the number of ignition failure self-recovery times is reset to zero; S3, controlling the ion electric propulsion to start the discharge chamber ignition mode, and in this mode, waiting for a first preset time t1 before entering step S4; S4. Determine whether the ion thruster acceleration current is within a preset range. If so, autonomous recovery is successful, the ion thruster stops ignition, the number of autonomous ignition failure recovery times is reset, and the process proceeds to step S5. Otherwise, the ion thruster stops ignition, waits for a second preset time t2 until the ion thruster cools down, and then returns to step S2. S5. After waiting for a third preset time t3, the ion electric propulsion automatically recovers to the normal ignition mode.

2. The onboard autonomous recovery method for non-resident faults induced by ion electric propulsion sparking according to claim 1, characterized in that: The method to judge the ignition failure is: Screen current I for ion electric propulsion b If the average value within a continuous preset time period exceeds k times the screen current rated value I0, the fault occurring during the ignition process of the ion electric propulsion system is considered to be an ignition fault; otherwise, the fault occurring during the ignition process of the ion electric propulsion system is considered to be a non-ignition fault; the value range of k is [2, 4].

3. The onboard autonomous recovery method for non-resident faults induced by ion electric propulsion sparking according to claim 2, characterized in that: The preset time period is 50us to 100us.

4. The onboard autonomous recovery method for non-resident faults induced by ion electric propulsion sparking according to claim 1, characterized in that: In the discharge chamber ignition mode, the two high-voltage power supplies, the screen grid power supply and the acceleration power supply, are in the off state, and the neutralizer touch-holding power supply, the cathode touch-holding power supply, and the anode power supply are normally turned on; in this mode, only plasma discharge is generated, no high-voltage accelerated ion beam is generated, and no thrust is generated.

5. The on-board autonomous recovery method for non-resident faults induced by ion electric propulsion sparking according to claim 1, characterized in that: In the normal ignition mode, the neutralizer holding power supply, cathode holding power supply, anode power supply, screen grid power supply and acceleration power supply are normally turned on; in this mode, there is a high-voltage accelerated ion beam to generate thrust.

6. The onboard autonomous recovery method for non-resident faults induced by ion electric propulsion sparking according to claim 1, characterized in that: The value range of the first preset time t1 is [60min, 120min].

7. The onboard autonomous recovery method for non-resident faults induced by ion electric propulsion sparking according to claim 1, characterized in that: The value range of the first preset time t2 is [30min, 60min].

8. The onboard autonomous recovery method for non-resident faults induced by ion electric propulsion sparks according to claim 1, characterized in that: The value range of the third preset time t3 is [10min, 30min].

9. The onboard autonomous recovery method for non-resident faults induced by ion electric propulsion sparking according to claim 1, characterized in that: The set range of the allowed number of autonomous recovery times N0 is [1, 10].

10. The onboard autonomous recovery method for non-resident faults induced by ion electric propulsion sparks according to claim 1, characterized in that: The preset range is [I1*90%, I1*110%], where I1 is a normal value of the acceleration current when there is no short circuit between gates.

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