A space vehicle heater control and status detection system

Abstract

The application discloses a space vehicle heater control and state detection system, which comprises a safety switch, n overcurrent protection circuits, n heaters, n heater safety switches, n voltage division circuits, a multipath buffer / bus driver, an internal bus and a CPU module; wherein the safety switch is connected with the power supply positive terminals of the n heaters; the power supply positive terminal of each heater is connected with one overcurrent protection circuit; the power supply negative terminal of each heater is connected with the corresponding heater safety switch of each heater; a voltage division circuit is connected between the power supply negative terminal of each heater and the corresponding heater safety switch of each heater; the n voltage division circuits are connected with the multipath buffer / bus driver; and the multipath buffer / bus driver is connected with the CPU module through the internal bus. The application has the advantages of small volume, light weight, low cost and high reliability, and can work in a complex and severe space environment.

Description

Technical Field

[0001] This invention belongs to the field of power supply and distribution control technology for spacecraft, and particularly relates to a spacecraft heater control and status detection system. Background Technology

[0002] Currently, the control methods for thermal control heaters in spacecraft (satellites) are generally mechanical switch control using relays or drive control methods using relays and MOSFETs. Because spacecraft typically have a large number of heaters, conventional A / D acquisition methods for realizing the heater's safety switch status involve large circuitry and require significant resources in terms of size and weight, making it difficult to implement heater safety switch status detection functionality. When a local temperature control function of the spacecraft malfunctions, the health status of the heater's safety switches cannot be determined in a timely manner, hindering fault location and on-orbit autonomous handling. Summary of the Invention

[0003] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a spacecraft heater control and status detection system with the advantages of miniaturization, lightweight, low cost and high reliability.

[0004] The objective of this invention is achieved through the following technical solution: a spacecraft heater control and status detection system, comprising: a safety switch, n overcurrent protection circuits, n heaters, n heater safety switches, n voltage divider circuits, a multi-channel buffer / bus driver, an internal bus, and a CPU module; wherein, each safety switch is connected to the positive power supply terminal of each heater; each heater's positive power supply terminal is connected to an overcurrent protection circuit; each heater's negative power supply terminal is connected to its corresponding heater safety switch; a voltage divider circuit is connected between each heater's negative power supply terminal and its corresponding heater safety switch; the n voltage divider circuits are connected to the multi-channel buffer / bus driver; the multi-channel buffer / bus driver is connected to the CPU module via the internal bus; the voltage signal output by each voltage divider circuit is converted into a heater safety switch status signal by the multi-channel buffer / bus driver, which transmits the heater safety switch status information to the internal bus, and the CPU module reads the heater safety switch status information via the internal bus. n is a positive integer.

[0005] In the aforementioned spacecraft heater control and status monitoring system, the voltage divider circuit includes resistors R21, R22, and R23; wherein, one end of resistor R1 is connected to the negative power supply terminal of the heater; resistors R22 and R23 are connected in parallel and then connected to the other end of resistor R21.

[0006] In the aforementioned spacecraft heater control and status monitoring system, the voltage divider circuit includes resistor R24, resistor R25, and diode D1; wherein, one end of resistor R24 ​​is connected to the negative terminal of the heater power supply, and the other end of resistor R24 ​​is connected in series with resistor R25 to form a voltage divider circuit; diode D1 is connected in parallel in the bypass of resistor R25 as a Zener diode.

[0007] In the aforementioned spacecraft heater control and status monitoring system, the safety switch includes resistors R31, R32, R33, R34, R35, R36, and R37, a transistor Q1, a MOSFET switch PMOS1, and a MOSFET switch PMOS2. Resistor R31 is connected to the control signal input terminal of transistor Q1; when the control signal is high, transistor Q1 conducts. Resistor R32 is connected to the base and emitter of transistor Q1, respectively; when there is no control signal, transistor Q1 conducts. When the control signal is input, ensure that transistor Q1 is in a stable non-conducting state; one end of resistors R34 and R35 connected in parallel is connected to the bus power supply +, and the other end of resistors R34 and R35 connected in parallel is connected to one end of resistor R33; the other end of resistor R33 is connected to the collector of transistor Q1; resistor R36 is connected to the control signal input terminal of MOS switch PMOS1; resistor R37 is connected to the control signal input terminal of MOS switch PMOS2.

[0008] In the aforementioned spacecraft heater control and status monitoring system, the overcurrent protection circuit includes fuse FU1 and fuse FU2; wherein fuse FU1 and fuse FU2 are connected in parallel.

[0009] In the aforementioned spacecraft heater control and status monitoring system, the overcurrent protection circuit includes fuse FU3, fuse FU4, and resistor R41; wherein fuse FU4 and resistor R41 are connected in series and then in parallel with fuse FU3.

[0010] In the aforementioned spacecraft heater control and status monitoring system, transistor Q1 controls the on / off state of two PMOS transistors, PMOS1 and PMOS2. When transistor Q1 is on, the voltage V of PMOS1 and PMOS2 is... GS When the conduction threshold is reached, MOSFET switches PMOS1 and PMOS2 are turned on, meaning the heater power supply begins to output.

[0011] In the aforementioned spacecraft heater control and status monitoring system, when transistor Q1 is not conducting, the voltage V of MOSFET switches PMOS1 and PMOS2 is... GSIf the conduction threshold cannot be reached, MOSFET switches PMOS1 and PMOS2 are turned off, meaning the heater power supply stops outputting.

[0012] In the aforementioned spacecraft heater control and status monitoring system, the voltage V of the MOS transistor switch PMOS1 is... GS It can be obtained through the following formula:

[0013] V GS =(V CC -V Q1 )*R34‖R35 / (R34‖R35+R33);

[0014] Among them, V cc V is the power supply voltage. Q1 R33 is the on-state voltage drop of transistor Q1, R34 is the resistance value of resistor R34, and R35 is the resistance value of resistor R35.

[0015] In the aforementioned spacecraft heater control and status monitoring system, the on-state voltage drop of transistor Q1 is <2V.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] This invention addresses the needs of spacecraft products for miniaturization, lightweighting, low cost, and high reliability. It employs a resistor voltage divider circuit with a buffer / bus driver to detect the switch status, replacing the A / D acquisition method for heater safety switch status detection. This simplifies the circuit system and meets the engineering application requirements of spacecraft. Attached Figure Description

[0018] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0019] Figure 1 This is a structural block diagram of the spacecraft heater control and status detection system provided in an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the remote voltage divider circuit for measuring the status of the heater safety switch provided in an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the safety switch drive control principle provided by an embodiment of the present invention, which uses two PMOS transistors connected in parallel.

[0022] Figure 4This is a schematic diagram of two balanced and two unbalanced overcurrent protection circuits provided in an embodiment of the present invention. Detailed Implementation

[0023] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] Figure 1 This is a structural block diagram of the spacecraft heater control and status monitoring system provided in an embodiment of the present invention. Figure 1 As shown, the spacecraft heater control and status monitoring system includes a safety switch, n overcurrent protection circuits, n heaters, n heater safety switches, n voltage divider circuits, a multi-channel buffer / bus driver, an internal bus, and a CPU module; among which,

[0025] Each safety switch is connected to the positive power supply terminal of each heater; each heater's positive power supply terminal is connected to an overcurrent protection circuit; each heater's negative power supply terminal is connected to its corresponding heater safety switch; a voltage divider circuit is connected between each heater's negative power supply terminal and its corresponding heater safety switch; n voltage divider circuits are connected to a multi-channel buffer / bus driver; the multi-channel buffer / bus driver is connected to the CPU module via the internal bus; the voltage signal output by each voltage divider circuit is converted into a heater safety switch status signal by the multi-channel buffer / bus driver, which transmits the heater safety switch status information to the internal bus, and the CPU module reads the heater safety switch status information via the internal bus.

[0026] Each safety switch controls the positive terminal of n heater power supplies (n ranges from 2 to 6). At the same time, an independent overcurrent protection circuit is configured at the positive terminal of each heater power supply. A voltage divider circuit is designed between each heater and its corresponding heater safety switch. The voltage signal output by the voltage divider circuit passes through a multi-channel buffer / bus driver to transmit the heater safety switch status information to the internal bus. The CPU module reads the corresponding heater safety switch status information through the internal bus.

[0027] The signal relationship (control method) in this embodiment is as follows:

[0028] 1. The external safety switch control signal generated or received by the CPU module inside the single machine acts on the base of the transistor, and the transistor drive circuit controls the safety switch to be turned on or off.

[0029] 2. The external heater safety switch control signal generated or received by the CPU module inside the unit acts on the heater safety switch to control the heater safety switch to be turned on or off.

[0030] 3. Each heater is equipped with a voltage divider circuit at the negative terminal. The voltage divider circuit generates a telemetry voltage, which is processed by a level buffer / bus driver and then transmitted back to the CPU module via the internal bus to read the telemetry status of the heater safety switch.

[0031] The heater safety switch status detection uses a resistor voltage divider circuit. The voltage divider signal is converted into a switch status signal through a buffer / bus driver. The buffer / bus driver preferably uses 54HC244.

[0032] like Figure 2 As shown in (a), the voltage divider circuit includes resistors R21, R22, and R23; wherein, one end of resistor R1 is connected to the negative power supply terminal of the heater; resistors R22 and R23 are connected in parallel and then connected to the other end of resistor R21.

[0033] Or such as Figure 2 As shown in (b), the voltage divider circuit includes resistor R24, resistor R25 and diode D1; wherein one end of resistor R24 ​​is connected to the negative terminal of the heater power supply, and the other end of R25 is connected in series to form a voltage divider circuit; the diode D1 is connected in parallel in the bypass of resistor R25 as a Zener diode.

[0034] like Figure 3 As shown, the heater safety switch employs a redundant design with two PMOS transistors connected in parallel, driven and controlled by the same control signal. This embodiment uses a transistor drive circuit to turn the PMOS transistors on or off, leveraging the advantages of transistors' small size and light weight. The positive-terminal PMOS transistor switch used in this embodiment may handle currents of tens of amps, resulting in high and concentrated heat dissipation. TO-254 packaged PMOS transistors are selected and mounted on the flat surface of the module's internal structure, utilizing the excellent thermal conductivity of the module's metal structure for heat dissipation.

[0035] like Figure 3 As shown, the safety switch includes resistors R31, R32, R33, R34, R35, R36, and R37, transistor Q1, MOSFET switch PMOS1, and MOSFET switch PMOS2; among which,

[0036] The resistor R31 is connected to the control signal input terminal of transistor Q1. When the control signal is high, transistor Q1 is turned on.

[0037] The resistor R32 is connected to the base and emitter of transistor Q1 respectively, ensuring that transistor Q1 is in a stable non-conducting state when there is no control signal input.

[0038] One end of the resistor R34 and the resistor R35 connected in parallel is connected to the bus power supply +, and the other end of the resistor R34 and the resistor R35 connected in parallel is connected to one end of the resistor R33.

[0039] The other end of the resistor R33 is connected to the collector of the transistor Q1;

[0040] The resistor R36 is connected to the control signal input terminal of the MOS switch PMOS1;

[0041] The resistor R37 is connected to the control signal input terminal of the MOS switch PMOS2.

[0042] Resistors R33, R34, and R35 form a series-parallel voltage divider network, which is connected to the bus power supply + and one end of the transistor, respectively.

[0043] Resistors R36 and R37 are connected to the control signal input terminals of two MOS switching transistors PMOS1 and PMOS2, respectively, to increase the input impedance.

[0044] The transistor Q1 controls the conduction and turn-off of two PMOS transistors. When Q1 is turned on, the VGS voltage of the corresponding PMOS1 and PMOS2 devices reaches the conduction threshold, and PMOS1 and PMOS2 are turned on, that is, the heater power supply starts to output. When Q1 is not turned on, the VGS voltage of the corresponding PMOS1 and PMOS2 devices cannot reach the conduction threshold, and PMOS1 and PMOS2 are turned off, that is, the heater power supply stops outputting.

[0045] The overcurrent protection circuit uses fuses, and the fuse circuit structure consists of two fuses in parallel or two unbalanced fuses.

[0046] like Figure 4 As shown in (a), the overcurrent protection circuit includes fuse FU1 and fuse FU2; wherein FU1 and FU2 are connected in parallel in the heater circuit.

[0047] Or such as Figure 4 As shown in (b), the overcurrent protection circuit includes fuse FU3, fuse FU4 and resistor R41; wherein fuse FU4 and resistor R41 are connected in series in the circuit, and then connected in parallel with fuse FU3 in the circuit for use.

[0048] Each heater's positive terminal uses a fuse for overcurrent protection. The fuse circuit can be configured as a single fuse, two fuses in parallel, or two fuses in unbalanced parallel. Each heater's negative terminal is controlled by a single NMOS transistor, and each switch is controlled by an independent control signal.

[0049] This embodiment implements control of spacecraft heaters using MOSFET electronic switches. Each safety switch controls the positive terminal of multiple heater power supplies. An independent overcurrent protection circuit is configured at the positive terminal of each heater power supply. A voltage divider circuit is designed between each heater and its corresponding safety switch. The voltage signal output from the voltage divider circuit passes through a multi-channel buffer / bus driver, transmitting the heater safety switch status information to the internal bus. The CPU module reads the corresponding heater safety switch status information through the internal bus. This embodiment allows functions that previously required a single unit to be completed with only one or a few functional modules, offering high reliability and advantages such as miniaturization, lightweight design, low cost, and high reliability.

[0050] 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 spacecraft heater control and status detection system, characterized by The application relates to a safety switch for a heater, which comprises a total safety switch, n overcurrent protection circuits, n heaters, n heater safety switches, n voltage dividing circuits, a multiplex buffer / bus driver, an internal bus and a CPU module. The total safety switch is connected with the positive power supply end of each heater. An overcurrent protection circuit is connected between the positive power supply end of each heater and the total safety switch. The negative power supply end of each heater is connected with the heater safety switch corresponding to the heater. A voltage dividing circuit is connected between the negative power supply end of each heater and the heater safety switch corresponding to the heater. The n voltage dividing circuits are connected with the multiplex buffer / bus driver. The multiplex buffer / bus driver is connected with the CPU module through the internal bus. The voltage signal output by each voltage dividing circuit is converted into a heater safety switch state signal by the multiplex buffer / bus driver, the multiplex buffer / bus driver transmits the heater safety switch state information to the internal bus, and the CPU module reads the heater safety switch state information through the internal bus. The voltage dividing circuit comprises resistors R21, R22 and R23.

2. The spacecraft heater control and status detection system of claim 1, wherein: One end of the resistor R21 is connected with the negative power supply end of the heater. The resistor R22 and the resistor R23 are connected with the other end of the resistor R21 in parallel. The voltage dividing circuit comprises resistors R24, R25 and a diode D1.

3. The spacecraft heater control and status detection system of claim 1, wherein: One end of the resistor R24 is connected with the negative power supply end of the heater, and the other end of the resistor R24 is connected with the resistor R25 in series to form the voltage dividing circuit.

4. The spacecraft heater control and status detection system of claim 1, wherein: The diode D1 is connected in parallel with the resistor R25 as a voltage stabilizing diode. The total safety switch comprises resistors R31, R32, R33, R34, R35, R36, R37, a triode Q1, a MOS switch PMOS1 and a MOS switch PMOS2. The resistor R31 is connected with the control signal input end of the triode Q1, and the triode Q1 is turned on when the control signal is high. The resistor R32 is connected with the base and the emitter of the triode Q1 respectively, and ensures that the triode Q1 is in a stable non-conduction state when no control signal is input. The resistor R34 and the resistor R35 are connected with the bus power supply + in parallel, and the other end of the resistor R34 and the resistor R35 is connected with one end of the resistor R33. The other end of the resistor R33 is connected with the collector of the triode Q1. The resistor R36 is connected with the control signal input end of the MOS switch PMOS1.

5. The spacecraft heater control and status detection system of claim 1, wherein: The resistor R37 is connected with the control signal input end of the MOS switch PMOS2.

6. The spacecraft heater control and status detection system of claim 1, wherein: The overcurrent protection circuit comprises a fuse FU1 and a fuse FU2, and the fuse FU1 and the fuse FU2 are connected in parallel.

7. The spacecraft heater control and status detection system of claim 4, wherein: The transistor Q1 controls the on and off of the two PMOS tubes of MOS switch PMOS1 and MOS switch PMOS2. When the transistor Q1 is on, the voltage V GS of the MOS switch PMOS1 and the MOS switch PMOS2 reaches the on threshold, the MOS switch PMOS1 and the MOS switch PMOS2 are on, that is, the heater power supply starts to output.

8. The spacecraft heater control and status detection system of claim 7, wherein: When the triode Q1 is not conducting, the voltage V GS If the threshold value cannot be reached, the MOS switches PMOS1 and PMOS2 are turned off, i.e. the heater power supply stops outputting.

9. The spacecraft heater control and status detection system of claim 4, wherein: The voltage V of the MOS switch PMOS1 GS This is obtained by the following equation: V GS = (V CC -V Q1 )*R34‖R35 / (R34‖R35+R33); wherein V cc is the supply voltage, V Q1 is the on voltage drop of the transistor Q1, R33 is the resistance value of the resistor R33, R34 is the resistance value of the resistor R34, and R35 is the resistance value of the resistor R35.

10. The spacecraft heater control and status detection system of claim 4, wherein: The overcurrent protection circuit comprises a fuse FU3, a fuse FU4 and a resistor R41, and the fuse FU4 and the resistor R41 are connected in series and then connected with the fuse FU3 in parallel. The conduction voltage drop of the triode Q1 is less than 2V.

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