An on-board autonomous recovery method for ion electric propulsion misfire induced by ignition

Abstract

The present application belongs to the technical field of spacecraft electric propulsion system, and relates to a kind of on-board autonomous recovery method of ion electric propulsion firing induced non-resident fault: whether the fault occurred in the ignition process of ion electric propulsion system is firing fault is judged, if it is firing fault, control ion electric propulsion to start discharge chamber ignition mode, in the mode, after waiting for first preset time t1, whether ion electric propulsion acceleration current is within the preset range is judged, if yes, autonomous recovery is successful, ion electric propulsion stops ignition, after waiting for third preset time t3, ion electric propulsion is autonomously recovered to normal ignition mode;Otherwise, ion electric propulsion stops ignition, waits for second preset time t2, until ion thruster cools down, repeat the above process several times.

Description

Technical Field

[0001] This invention belongs to the field of spacecraft electric propulsion system technology, and in particular relates to an on-board autonomous recovery method for non-resident faults induced by ion electric propulsion arcing, which is applicable to on-orbit fault handling of ion electric propulsion. Background Technology

[0002] Ultra-low Earth orbit (ULE) satellites, with their low orbits and high atmospheric drag, are constrained by satellite weight. Traditional chemical propulsion systems cannot meet the total impulse requirements throughout their operational lifespan, necessitating the use of high-specific-impulse ion electric propulsion systems. During ion electric propulsion ignition, the operating voltage between the ion thruster's grid and accelerating grid reaches over 1000V, with a spacing of less than 1mm. Due to dust, sputtered deposits, and grid burrs, instantaneous short circuits between the grid and accelerating grid inevitably occur, a phenomenon known as sparking. Grid-to-grid sparking is an inherent characteristic of ion thrusters. In the event of sparking, ignition is typically stopped to protect the overall satellite power supply. For ULE satellites, due to high atmospheric drag, the ion electric propulsion system needs to perform more than ten orbit control tasks daily, each lasting 30 minutes to 1 hour. Most ignition occurs outside the telemetry and control phase. Existing ion electric propulsion systems, upon experiencing a sparking fault in orbit, directly shut down, stopping ignition and awaiting ground intervention for troubleshooting and remediation. If the fault is successfully resolved, ignition can be resumed via remote ground control.

[0003] To prevent rapid orbital decay caused by prolonged failure to restore ignition during non-tracking and control periods after an ion electric propulsion system ignition failure, it is necessary to implement onboard autonomous protection and recovery for ion electric propulsion ignition failures in ultra-low orbit satellites. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose an on-board autonomous recovery method for non-resident faults induced by ion electric propulsion sparking. This method enables the satellite to autonomously execute a shutdown procedure when inter-grid sparking occurs during non-telemetry and control arcs, protecting the overall satellite energy safety. Then, the satellite can restore normal ignition through the on-board autonomous recovery method, ensuring that the satellite will not fail to perform orbit maintenance missions due to non-resident inter-grid sparking faults during non-telemetry and control arcs.

[0005] The solution to the technical problem of this invention is: an on-board autonomous recovery method for non-residential faults induced by ion electric propulsion arcing, the method comprising the following steps:

[0006] S1. Determine whether the fault that occurs during the ignition process of the ion electric propulsion system is an ignition fault. If it is not an ignition fault, then end; otherwise, initialize the number of autonomous recovery times for ignition faults N=0 and proceed to step S2.

[0007] S2, number of times the ignition fault can be automatically recovered N = N + 1. If N ≤ the set number of times the automatic recovery can be recovered N0, then step S3 is executed. Otherwise, the ion electric propulsion is used to stop ignition and the number of times the ignition fault can be automatically recovered is cleared to zero.

[0008] S3. Control the ion electric propulsion to start the discharge chamber ignition mode, and wait for the first preset time t1 in this mode before proceeding to step S4.

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

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

[0011] Preferably, the method for determining ignition failure is as follows:

[0012] Grid current I of ion electric propulsion b If the average value over a consecutive preset time period exceeds k times the rated value I0 of the grid current, then 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 of k ranges from [2, 4].

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

[0014] Preferably, in the discharge chamber ignition mode, the two high-voltage power supplies, the grid power supply and the acceleration power supply, are in the off state, while the neutralizer contact power supply, the cathode contact 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 contact power supply, cathode contact power supply, anode power supply, grid power supply and acceleration power supply are normally turned on; in this mode, there is a high-voltage accelerated ion beam that generates thrust.

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

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

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

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

[0020] Preferably, the preset range is [I1*90%, I1*110%], where I1 is the normal value of the accelerating current under non-short-circuit conditions between gates.

[0021] The advantages of this invention compared to the prior art are:

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

[0023] (2) The present invention uses the method of entering the discharge chamber mode to realize the on-board autonomous recovery of non-resident ignition failure of ion electric propulsion. No thrust is generated during the autonomous recovery process, thus avoiding the impact on the satellite's attitude and orbit.

[0024] (3) The present invention uses the acceleration current value of ion electric propulsion to judge the short circuit state between gates. Without adding extra resources, it realizes the diagnosis of whether the gate arcing is a permanent fault. The method is simple and reliable.

[0025] (4) In the autonomous recovery ignition process, the present invention limits the number of recovery ignitions to avoid the ion electric propulsion system having a permanent fault and entering a dead loop of "ignition-firing fault", which would cause the satellite's energy and propellant to be consumed. Attached Figure Description

[0026] Figure 1 This invention relates to an onboard autonomous recovery method for non-resident faults induced by ion electric propulsion ignition, as described in an embodiment of the present invention. Detailed Implementation

[0027] The present invention will be further described below with reference to the embodiments.

[0028] like Figure 1 As shown, to avoid rapid orbital decay caused by prolonged failure of the ion electric propulsion system to resume ignition during non-telemetry and control arcs in ultra-low orbit satellites, this invention proposes an on-board autonomous recovery method for non-resident faults induced by ion electric propulsion ignition. This method recovers the non-resident gate short-circuit fault of the ion electric propulsion system, and includes the following steps:

[0029] S1. Determine whether the fault that occurs during the ignition process of the ion electric propulsion system is an ignition fault. If it is not an ignition fault, then end; otherwise, initialize the number of autonomous recovery times for ignition faults N=0 and proceed to step S2.

[0030] Preferably, the method for diagnosing ignition failure is as follows:

[0031] Grid current I of ion electric propulsion b If the average value over a continuously preset time period exceeds k times the rated value I0 of the grid current, then the fault occurring during the ignition process of the ion electric propulsion system is considered an ignition fault; otherwise, the fault occurring during the ignition process of the ion electric propulsion system is considered a non-ignition fault; the value of k ranges from [2, 4]. The preset time period is 50us to 100us.

[0032] S2, number of times the ignition fault can be automatically recovered N = N + 1. If N ≤ the set number of times the automatic recovery can be recovered N0, then step S3 is executed. Otherwise, the ion electric propulsion is used to stop ignition and the number of times the ignition fault can be automatically recovered is cleared to zero.

[0033] The allowed number of autonomous recovery attempts N0 is set to range from [1, 10].

[0034] S3. Control the ion electric propulsion to start the discharge chamber ignition mode, and wait for the first preset time t1 in this mode before proceeding to step S4.

[0035] In the discharge chamber ignition mode, the two high-voltage power supplies, the grid power supply and the acceleration power supply, are in the off state, while the neutralizer contact power supply, the cathode contact power supply, and the anode power supply are normally turned on. In this mode, only plasma discharge is generated, without a high-voltage accelerated ion beam, and no thrust is generated.

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

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

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

[0039] The preset range is [I1*90%, I1*110%], where I1 is the normal value of the accelerating current under non-short-circuit conditions between gates.

[0040] The inter-gate short circuit state is determined by the acceleration current value of ion electric propulsion. Without adding extra resources, the method can diagnose whether the gate arcing is a persistent fault. The method is simple and reliable.

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

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

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

[0044] In summary, this invention achieves onboard autonomous recovery from non-resident ignition failures in ion electric propulsion by employing a discharge chamber entry method. No thrust is generated during the autonomous recovery process, thus avoiding any impact on the satellite's attitude and orbit. Furthermore, this invention limits the number of ignition attempts during the autonomous recovery ignition process to prevent the ion electric propulsion system from experiencing persistent ignition failures and entering a vicious cycle of "ignition-failure," which would otherwise deplete the satellite's energy and propellant.

[0045] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations 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 protection scope of the technical solutions of the present invention.

Claims

1. A method for onboard autonomous recovery from non-resident faults induced by ion electric propulsion sparking, characterized in that... Includes the following steps: S1. Determine whether the fault that occurs during the ignition process of the ion electric propulsion system is an ignition fault. If it is not an ignition fault, then end; otherwise, initialize the number of autonomous recovery times for ignition faults N=0 and proceed to step S2. S2, number of times the ignition fault can be automatically recovered N = N + 1. If N ≤ the set number of times the automatic recovery can be recovered N0, then step S3 is executed. Otherwise, the ion electric propulsion is used to stop ignition and the number of times the ignition fault can be automatically recovered is cleared to zero. S3. Control the ion electric propulsion to start the discharge chamber ignition mode, and wait for the first preset time t1 in this mode before proceeding to step S4. S4. Determine whether the ion electric propulsion acceleration current is within the preset range. If yes, the autonomous recovery is successful, the ion electric propulsion stops ignition, the number of autonomous recovery counts for ignition failure is cleared to zero, and the process proceeds to step S5. Otherwise, the ion electric propulsion stops ignition and waits for the second preset time t2 until the ion thruster cools down, then returns to step S2. S5. After waiting for the third preset time t3, the ion electric propulsion will automatically return to the normal ignition mode.

2. The on-board autonomous recovery method for non-resident faults induced by ion electric propulsion sparking according to claim 1, characterized in that, The method for diagnosing ignition problems is as follows: Grid current I of ion electric propulsion b If the average value over a consecutive preset time period exceeds k times the rated value I0 of the grid current, then 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 of k ranges from [2, 4].

3. The on-board 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 50μs to 100μs.

4. 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 discharge chamber ignition mode, the two high-voltage power supplies, the grid power supply and the acceleration power supply, are in the off state, while the neutralizer contact power supply, the cathode contact power supply, and the anode power supply are normally turned on. In this mode, only plasma discharge is generated, without a high-voltage accelerated ion beam, 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 contact power supply, cathode contact power supply, anode power supply, grid power supply and acceleration power supply are turned on normally; in this mode, there is a high-voltage accelerated ion beam that generates thrust.

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

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

8. The on-board 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 third preset time t3 is [10min, 30min].

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

10. The on-board autonomous recovery method for non-resident faults induced by ion electric propulsion sparking according to claim 1, characterized in that, The preset range is [I1*90%, I1*110%], where I1 is the normal value of the accelerating current under non-short-circuit conditions between gates.

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