A non-contact photoionization sensing system

Abstract

The application discloses a non-contact photoionization sensitive system, which comprises the following parts: a photoelectric sensor, which is fixedly installed on an off-machine structure, emits infrared light to an inner wall plate of a cabin, and converts a received reflected light signal into a level signal and outputs the level signal to an interface circuit; the interface circuit, which receives the level signal output by the photoelectric sensor and forwards the level signal to a shaping circuit; the shaping circuit, which receives the level signal forwarded by the interface circuit, performs shaping processing on the level signal, and outputs the shaped level signal to a driving circuit; and the driving circuit, which receives the shaped level signal output by the shaping circuit, converts the shaped level signal into a control signal of an electromagnetic relay, drives the electromagnetic relay to act, and realizes power-on of an electrical product in the off-machine structure. The application adopts non-contact photoelectric measurement technology and overload sensing technology to autonomously judge the off-machine state of the system, has high integration degree, and ensures the reliability of power-on output of the system.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of non-contact photoionization sensitive system, belong to spacecraft recovery control technical field. BACKGROUND

[0002] In the field of aerospace recovery controller, it needs to rely on a large number of air-drop tests to carry out technical verification, through the plane to the spacecraft return cabin to the predetermined height, then release the return cabin, the return cabin is powered on and executes control instruction, ensure that the spacecraft return cabin is powered on after leaving the plane is the key to the success of air-drop test.

[0003] At present, in the spacecraft return cabin air-drop test, travel switch or pull pin is mostly used as the control mode of power-on after leaving the plane, whether the return cabin has left the plane is reflected by the switch state, and the control system is powered on after judging that the return cabin is in the state of leaving the plane. Travel switch is mechanically triggered, and some aircraft models cannot be mechanically punched, so travel switch cannot be installed. Pull pin needs to be connected to the return cabin by a long rope, and the pull pin is disconnected after the return cabin is pushed out of the cabin by the slide rail, and the control system is powered on. The pull pin rope will have some impact on the installation and launching of the return cabin. If there is a jam that causes the pull pin to disconnect while the return cabin is not leaving the plane, the control system of the return cabin will be powered on and execute the action, which will bring safety risk to the plane. Therefore, it is urgent to solve the problem of high reliability and high safety power-on of the return cabin model in air-drop test. SUMMARY

[0004] The technical problem solved by the present application is to overcome the shortcomings of the prior art and provide a non-contact photoionization sensitive system that uses non-contact photoelectric measurement technology and overload sensing technology to autonomously judge the system leaving state, has high integration and ensures the reliability of system power-on output.

[0005] The technical solution of the present application is: A non-contact photoionization sensitive system, comprising: a photoelectric sensor, an interface circuit, a shaping circuit, a driving circuit and an electromagnetic relay; The photoelectric sensor is fixedly installed on the leaving structure, emits infrared light to the cabin inner wall plate, and converts the received reflected light signal into a level signal output to the interface circuit; The interface circuit receives the level signal output by the photoelectric sensor and forwards it to the shaping circuit; The shaping circuit receives the level signal forwarded by the interface circuit, performs shaping processing and outputs it to the driving circuit; The driving circuit receives the shaped electrical signal output by the shaping circuit, converts the electrical signal into a control signal of the electromagnetic relay to drive the electromagnetic relay to act, and realizes the power-on of the electrical product in the leaving structure.

[0006] Preferably, it further comprises a state detection circuit; State detection circuit: receiving the shaped electrical signal output by the shaping circuit, driving the LED lamp with the shaped electrical signal, and displaying as a photoelectric sensor signal state.

[0007] Preferably, the interface circuit includes: a resistor R1, a resistor R2, a capacitor C1, and a capacitor C2; One end of the resistor R1 is an input end of the interface circuit, receiving a level signal output by the photoelectric sensor; the other end of the resistor R1 is connected to a power supply; One end of the capacitor C1 is connected to one end of the resistor R1, one end of the capacitor C2, and one end of the resistor R2; The other end of the capacitor C1 is connected to the same reference ground as the ground end of the photoelectric sensor, and the other end of the capacitor C1 is grounded; the other end of the capacitor C2 is connected to the other end of the capacitor C1 and the other end of the resistor R2; One end of the resistor R2 is an output end of the interface circuit, connected to an input end of the shaping circuit.

[0008] Preferably, the shaping circuit includes: a first AND gate logic device U2A, a second AND gate logic device U2B, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a capacitor C8, a capacitor C9, a capacitor C10, a first inverter U1A, a second inverter U1B, a third inverter U1C, and a fourth inverter U1D; The input end of the first inverter U1A is an input end of the shaping circuit, connected to one end of the resistor R2; The input end of the second inverter U1B is connected to the input end of the first inverter U1A, the input end of the third inverter U1C, and the input end of the fourth inverter U1D; The output end of the first inverter U1A is connected to one end of the resistor R3; the other end of the resistor R3 is connected to one end of the capacitor C3 and a first input end of the first AND gate logic device U2A; the other end of the capacitor C3 is grounded; The output end of the second inverter U1B is connected to one end of the resistor R4; the other end of the resistor R4 is connected to one end of the capacitor C4 and a second input end of the first AND gate logic device U2A; the other end of the capacitor C4 is grounded; The power supply end of the first AND gate logic device U2A is connected to one end of the resistor R7; the other end of the resistor R7 is connected to a power supply; one end of the resistor R7 is connected to one end of the capacitor C7 and one end of the capacitor C8; the other end of the capacitor C7 and the other end of the capacitor C8 are grounded; The input end of the third inverter U1C is connected to one end of the resistor R5; the other end of the resistor R5 is connected to one end of the capacitor C5 and a first input end of the second AND gate logic device U2B; the other end of the capacitor C5 is grounded; The output end of the fourth inverter U1D is connected with one end of the resistor R6, the other end of the resistor R6 is connected with one end of the capacitor C6 and the second input end of the second AND gate logic device U2B, and the other end of the capacitor C6 is grounded; The power supply end of the second AND gate logic device U2B is connected with one end of the resistor R8, the other end of the resistor R8 is connected with the power supply, one end of the resistor R8 is connected with one end of the capacitor C9 and one end of the capacitor C10, and the other end of the capacitor C9 and the other end of the capacitor C10 are grounded; The output end of the first AND gate logic device U2A and the output end of the second AND gate logic device U2B are used as the output end of the shaping circuit and are connected with the input end of the driving circuit.

[0009] Preferably, the driving circuit comprises a diode D1, a diode D2, a diode D3, a diode D4, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a capacitor C11, a capacitor C12, an NPN triode D5, an NPN triode D6, an NPN triode D7 and an NPN triode D8. The anode of the diode D1 and the anode of the diode D2 are used as the input end of the driving circuit and are connected with the output end of the first AND gate logic device U2A. The cathode of the diode D1 is connected with one end of the resistor R9, the other end of the resistor R9 is connected with one end of the resistor R11 and the base of the NPN triode D5, and the other end of the resistor R11 is connected with the emitter of the NPN triode D5. The cathode of the diode D2 is connected with one end of the resistor R10, the other end of the resistor R10 is connected with one end of the resistor R12, one end of the capacitor C11 and the base of the NPN triode D6, the other end of the capacitor C11 is grounded, the other end of the resistor R12 is connected with the other end of the capacitor C11 and the emitter of the NPN triode D6, and the collector of the NPN triode D6 is connected with the other end of the resistor R11. The anode of the diode D3 and the anode of the diode D4 are used as the input end of the driving circuit and are connected with the output end of the second AND gate logic device U2B. The cathode of the diode D3 is connected with one end of the resistor R13, the other end of the resistor R13 is connected with one end of the resistor R14 and the base of the NPN triode D7, and the other end of the resistor R14 is connected with the emitter of the NPN triode D7. The cathode of the diode D4 is connected with one end of the resistor R15, the other end of the resistor R15 is connected with one end of the resistor R16, one end of the capacitor C12 and the base of the NPN triode D8, the other end of the capacitor C12 is grounded, the other end of the resistor R16 is connected with the other end of the capacitor C12 and the emitter of the NPN triode D8, and the collector of the NPN triode D8 is connected with the other end of the resistor R14. The collector of the NPN triode D5 and the collector of the NPN triode D7 are output terminals of the driving circuit, and output the control signal of the electromagnetic relay to the electromagnetic relay.

[0010] Preferably, it further comprises: a single-chip microcomputer circuit, an overload sensor and an overload filtering and following circuit. The overload sensor measures the overload value of the off-structure and generates an overload sensor signal output to the interface circuit. The interface circuit forwards the received overload sensor signal to the overload filtering and following circuit. The overload filtering and following circuit receives the overload sensor signal forwarded by the interface circuit, performs filtering processing, and outputs the filtered electrical signal to the single-chip microcomputer circuit. The single-chip microcomputer circuit receives the filtered electrical signal output by the overload filtering and following circuit, judges that the off-structure is in a weightless state, and outputs a control signal to the driving circuit. The driving circuit receives the control signal output by the single-chip microcomputer circuit, converts the control signal into a control signal of the electromagnetic relay, drives the electromagnetic relay to act, and realizes the power-on of the electrical product in the off-structure.

[0011] Preferably, it further comprises: a temperature sampling and heating circuit and a case. The interface circuit, the shaping circuit, the driving circuit, the single-chip microcomputer circuit, the overload filtering and following circuit and the temperature sampling and heating circuit are fixed in the case, and the case is fixedly installed on the off-structure. The single-chip microcomputer circuit obtains a temperature sampling signal and outputs a thermal control signal to the temperature sampling and heating circuit from the temperature sampling signal. The temperature sampling and heating circuit receives the thermal control signal output by the single-chip microcomputer circuit, and controls the heating sheet to heat the case through the driving field effect tube.

[0012] Compared with the prior art, the advantages of the present application mainly lie in the following aspects: 1) The present application proposes an off-sensitive system with non-contact off-state sensing and power-on control, which solves the limitation of contact installation in the previous power-on control using a travel switch in the air-drop test, expands the installation and dropping mode of the air-drop test, and improves the intelligent control of the off-power-on of the return capsule model.

[0013] 2) The system uses multiple photoelectric sensors and overload sensors to sense and judge the off-state, uses a single-chip microcomputer and multiple electromagnetic relays to output control, and uses LED lights to detect the battery capacity and state, which greatly improves the integrated design of the system under reliable output signals.

[0014] 3) The application adopts photoelectric sensor as the main judging means of off-machine state, reflects the off-machine state through the distance change detected by the photoelectric sensor, realizes non-contact sensing detection and product power-on, and has good high and low temperature resistance and anti-vibration and impact characteristics.

[0015] 4) The application adopts overload sensor as the backup judging method of off-machine state, reflects the off-machine state through the overload value sensed by the overload sensor, and improves the reliability of off-machine sensing. The output signal of the overload sensor is subjected to low-pass filtering of hardware circuit and sliding window filtering of software, so as to effectively filter out overload measurement disturbance and high-frequency interference signal and improve the instruction accuracy of the output signal. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is an internal composition diagram of the non-contact photoelectric off-machine sensing system. Figure 2 It is power supply and information flow conversion of the photoelectric off-machine sensing system. Figure 3 It is a circuit schematic diagram of the photoelectric shaping and electromagnetic driving module. Figure 4 It is an external connection schematic diagram of the photoelectric off-machine sensing system. Figure 5 It is a schematic diagram of installation and off-machine process of the photoelectric off-machine sensing system on the return capsule. Figure 6 It is a working process flow chart of the photoelectric off-machine sensing system. DETAILED DESCRIPTION

[0017] In order to better describe the application, the application will be described in detail below in cooperation with the schematic diagram and examples.

[0018] The non-contact photoelectric off-machine sensing system of the application comprises a power supply conversion module, a photoelectric sensor, an overload sensor, an interface circuit, a shaping circuit, an overload filtering and following circuit, a driving circuit, a state detection circuit, a single-chip microcomputer circuit and a temperature sampling and heating circuit.

[0019] The photoelectric sensor emits infrared light, the emitted light is received by the receiving end of the photoelectric sensor after being reflected by the aircraft body, and the off-machine state of the return capsule is judged according to the received reflected light intensity. The photoelectric sensor is fixedly installed on the off-machine structure, emits infrared light to the cabin inner wall plate, and converts the received reflected light signal into a level signal and inputs it to the shaping circuit through the interface circuit; the input shaping circuit is shaped and processed, and then outputs to the single-chip microcomputer circuit, the driving circuit and the state detection circuit, the driving circuit receives the signal transmitted from the shaping circuit and converts it into a relay control signal to drive the relay to act.

[0020] The single-chip microcomputer circuit receives the photoelectric sensor signal after shaping processing, and is used for recording and storing the photoelectric sensor signal change. The state detection circuit receives the photoelectric sensor signal after the shaping processing as the state detection display of the sensor signal.

[0021] The overload sensor measures the overload value of the return cabin to determine whether the return cabin is in a weightless state, as a backup mode to determine the off-machine state of the return cabin, the overload sensor signal is filtered by the load filtering follow-up circuit and then input to the single-chip microcomputer circuit for processing and determination, and the output signal of the single-chip microcomputer controls the driving circuit to drive the relay to act.

[0022] The product case is provided with eight electric connectors, and the functions of equipment power supply, sensor signal acquisition, control signal output, state debugging detection and serial communication are realized through the electric connectors.

[0023] The interface circuit includes photoelectric sensor input and power supply circuit and overload sensor input and power supply circuit, and is responsible for signal input and output and external sensor power supply. The receiving voltage conversion circuit outputs are used to supply power to the external sensor; the photoelectric sensor signal and the overload sensor signal are received, the photoelectric sensor signal is output to the shaping circuit, and the overload sensor signal is output to the overload filtering follow-up circuit.

[0024] In an embodiment of the present application, the interface circuit includes resistors R1, R2, capacitors C1 and C2. One end of the resistor R1 is used as the input end of the interface circuit and receives the level signal output by the photoelectric sensor; the other end of the resistor R1 is connected to the power supply; One end of the capacitor C1 is connected to one end of the resistor R1, one end of the capacitor C2 and one end of the resistor R2. The other end of the capacitor C1 is connected to the same reference ground (i.e., the sensor ground and the control system ground of the off-machine structure are in a common ground relationship) with the ground end of the photoelectric sensor, the other end of the capacitor C1 is grounded, and the other end of the capacitor C2 is connected to the other end of the capacitor C1 and the other end of the resistor R2. One end of the resistor R2 is used as the output end of the interface circuit and is connected to the input end of the shaping circuit.

[0025] The shaping circuit receives the photoelectric signal output by the interface circuit, shapes the photoelectric sensor output signal, and outputs the shaped signal to the driving circuit, the single-chip microcomputer circuit and the state detection circuit, respectively. As shown in Figure 3 The photoelectric sensor output is connected to +5V through a 10KΩ resistor, when the detection distance of the photoelectric sensor is less than 300mm, the sensor output is high, when the detection distance of the photoelectric sensor is greater than 300mm, the sensor output is low, and the output signal is processed by the CD40106BM96 Schmitt trigger circuit to increase the driving capacity of the signal.

[0026] As shown in Figure 3As shown, the shaping circuit comprises: a first AND gate logic device U2A, a second AND gate logic device U2B, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a capacitor C8, a capacitor C9, a capacitor C10, a first inverter U1A, a second inverter U1B, a third inverter U1C and a fourth inverter U1D; An input end of the first inverter U1A is connected to one end of the resistor R2 as an input end of the shaping circuit; An input end of the second inverter U1B is connected to the input end of the first inverter U1A, an input end of the third inverter U1C and an input end of the fourth inverter U1D; An output end of the first inverter U1A is connected to one end of the resistor R3, and the other end of the resistor R3 is connected to one end of the capacitor C3 and a first input end of the first AND gate logic device U2A, and the other end of the capacitor C3 is grounded; An output end of the second inverter U1B is connected to one end of the resistor R4, and the other end of the resistor R4 is connected to one end of the capacitor C4 and a second input end of the first AND gate logic device U2A, and the other end of the capacitor C4 is grounded; A power supply end of the first AND gate logic device U2A is connected to one end of the resistor R7, and the other end of the resistor R7 is connected to a power supply; one end of the resistor R7 is connected to one end of the capacitor C7 and one end of the capacitor C8; the other end of the capacitor C7 and the other end of the capacitor C8 are grounded; An input end of the third inverter U1C is connected to one end of the resistor R5, and the other end of the resistor R5 is connected to one end of the capacitor C5 and a first input end of the second AND gate logic device U2B, and the other end of the capacitor C5 is grounded; An output end of the fourth inverter U1D is connected to one end of the resistor R6, and the other end of the resistor R6 is connected to one end of the capacitor C6 and a second input end of the second AND gate logic device U2B, and the other end of the capacitor C6 is grounded; A power supply end of the second AND gate logic device U2B is connected to one end of the resistor R8, and the other end of the resistor R8 is connected to a power supply; one end of the resistor R8 is connected to one end of the capacitor C9 and one end of the capacitor C10; the other end of the capacitor C9 and the other end of the capacitor C10 are grounded; An output end of the first AND gate logic device U2A and an output end of the second AND gate logic device U2B are connected to an input end of a driving circuit as output ends of the shaping circuit.

[0027] The shaping circuit outputs a Schmidt shaping signal of the first "and" then "or" operation processing to the driving circuit: the AND gate circuit adopts a three-input AND gate for logical "and" operation, two inputs of the AND gate are the sensor signals after Schmidt shaping, the other input of the AND gate adopts RC circuit pull-up to prevent the relay from being triggered by mistake when the product is powered on, and the two-way AND gate output is subjected to "or" operation and then output to the driving circuit. The shaping circuit outputs a Schmidt shaping signal of the first "and" operation to the state detection circuit, which can be connected to an external debugging board for state detection. The shaping circuit outputs a single Schmidt shaping signal to the single-chip microcomputer circuit for internal sensor detection and state recording.

[0028] The driving circuit receives the control signal output by the shaping circuit or the single-chip microcomputer circuit to drive the relay to act. The main driving circuit is composed of four NPN triodes connected in series and parallel, connected after the output of the two-way AND gate, each group of triodes is composed of two triodes connected in series, and the output of the two groups of triodes is connected in parallel to the main relay wire package to control the relay to act. The auxiliary driving circuit is composed of two triodes connected in series, connected after the output of the one-way AND gate, and the collector output of the triode is connected to the auxiliary relay wire package.

[0029] As shown in Figure 3 , the driving circuit comprises a diode D1, a diode D2, a diode D3, a diode D4, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a capacitor C11, a capacitor C12, an NPN triode D5, an NPN triode D6, an NPN triode D7, and an NPN triode D8; The anode of the diode D1 and the anode of the diode D2 are connected as the input end of the driving circuit and connected to the output end of the first AND gate logic device U2A; The cathode of the diode D1 is connected to one end of the resistor R9; the other end of the resistor R9 is connected to one end of the resistor R11 and the base of the NPN triode D5; the other end of the resistor R11 is connected to the emitter of the NPN triode D5; The cathode of the diode D2 is connected to one end of the resistor R10; the other end of the resistor R10 is connected to one end of the resistor R12, one end of the capacitor C11, and the base of the NPN triode D6; the other end of the capacitor C11 is grounded, and the other end of the resistor R12 is connected to the other end of the capacitor C11 and the emitter of the NPN triode D6; the collector of the NPN triode D6 is connected to the other end of the resistor R11; The anode of the diode D3 and the anode of the diode D4 are connected as the input end of the driving circuit and connected to the output end of the second AND gate logic device U2B; The cathode of the diode D3 is connected to one end of the resistor R13; the other end of the resistor R13 is connected to one end of the resistor R14 and the base of the NPN triode D7; the other end of the resistor R14 is connected to the emitter of the NPN triode D7; The cathode of the diode D4 is connected to one end of the resistor R15; the other end of the resistor R15 is connected to one end of the resistor R16, one end of the capacitor C12 and the base of the NPN triode D8; the other end of the capacitor C12 is grounded, and the other end of the resistor R16 is connected to the other end of the capacitor C12 and the emitter of the NPN triode D8; the collector of the NPN triode D8 is connected to the other end of the resistor R14; The collector of the NPN triode D5 and the collector of the NPN triode D7 are output terminals of the driving circuit, and output control signals of the electromagnetic relay to the electromagnetic relay.

[0030] The state detection circuit is connected after the Schmitt trigger circuit, and the photoelectric sensor signal is output after the Schmitt trigger circuit to control the triode and drive the LED lamp, which is used as the state detection display of the sensor signal.

[0031] The overload filter following circuit adopts a three-stage RC filter circuit to filter the overload signal input by the overload sensor, and the filtered signal is sent to the AD converter to convert the analog signal into a digital signal, which is convenient for the single-chip microcomputer to process. The servo voltage design is adopted between the overload sensor and the AD converter to eliminate the measurement precision deviation caused by the inconsistent reference levels of the two circuit systems.

[0032] The single-chip microcomputer circuit detects and saves the number of times of the relay action, and the number of times of the relay switch is saved in the EEPROM, which can be read through the MAX232 serial communication. In addition, the internal software of the single-chip microcomputer uses a sliding window to read the overload value. When the sum of the absolute values of the XYZ three-axis overload sensed by the overload sensor is less than 0.2g and the duration is greater than 5s, it indicates that the current model is in a weightless state, and a backup off instruction is issued to control the relay action. The single-chip microcomputer circuit can output the relay driving signal to the driving circuit, output the thermal control signal to the temperature sampling heating circuit, and output the number of times of the relay switch to the host computer through serial communication. When the off state is detected by the photoelectric sensor, the driving circuit receives the shaped electrical signal output by the shaping circuit, converts the electrical signal into a control signal of the electromagnetic relay to drive the electromagnetic relay to act, and realizes the power-on of the electrical product in the off structure. When the off state is detected by the overload sensor, the driving circuit receives the control signal output by the single-chip microcomputer circuit, converts the control signal into a control signal of the electromagnetic relay to drive the electromagnetic relay to act, and realizes the power-on of the electrical product.

[0033] The interface circuit, the shaping circuit, the drive circuit, the single-chip microcomputer circuit, the overload filtering following circuit and the temperature sampling heating circuit are fixed in the case, and the case is fixed and installed on the off-machine structure. The single-chip microcomputer circuit obtains a temperature sampling signal, outputs a thermal control signal to the temperature sampling heating circuit from the temperature sampling signal, the temperature sampling heating circuit collects a temperature signal to the single-chip microcomputer circuit, receives the thermal control signal output by the single-chip microcomputer circuit, and controls the heating sheet to heat the case through the drive field effect tube. Six temperature acquisition and six heating sheets are equipped, wherein, the current limiting circuit is added to every three heating sheets, the temperature sampling signal is detected by the single-chip microcomputer and the heating control signal is output, the heating sheet is controlled by the drive field effect tube to heat the product case, and the temperature sampling signal of the feedback thermistor is fed back to the single-chip microcomputer circuit.

[0034] As shown in Figure 2 The power supply conversion module is used for providing +24V input voltage for the internal circuit of the off-machine sensor, +28V main and standby power supply for the electromagnetic relay, +15V power supply for the photoelectric sensor and +5.2V power supply for the overload sensor.

[0035] The two groups of lithium batteries are connected in parallel to supply power, and 24V input voltage is provided for the off-machine sensor product (photoelectric sensor, overload sensor). The two groups of batteries are connected to the circuit to form main and standby power supply, and are connected in the product to form redundant backup power supply, so as to ensure the stability of the battery power supply.

[0036] The power supply switch circuit receives the voltage input by the battery pack, and outputs to the power supply interface protection circuit and the battery capacity detection circuit after being controlled by the pull pin switch; The power supply interface protection circuit receives the system power supply output by the power supply switch circuit, performs surge suppression and filtering processing, and then outputs to the voltage conversion circuit; The voltage conversion circuit receives the filtered primary power output by the power supply interface protection circuit, performs DCDC conversion to generate secondary power, and outputs to the photoelectric sensor, overload sensor, single-chip microcomputer circuit and drive circuit in the system.

[0037] The power supply switch circuit uses the pull pin switch to control the power-on and power-off of the product, controls the conduction state of the PMOS tube through the pull pin switch, the positive and negative ends of the switch are connected, the drain and source of the PMOS tube are conducted, and the product is powered on.

[0038] The power supply interface protection circuit includes a surge suppression and EMI filtering circuit.

[0039] The surge suppression circuit receives the battery power output by the power supply switch circuit, performs power-on surge suppression, and outputs a power supply signal to the EMI filter circuit; the EMI filter circuit is composed of common-mode filtering and differential-mode filtering, receives the output power supply signal of the surge suppression circuit, and outputs a signal filtered of interference noise to the voltage conversion circuit.

[0040] The voltage conversion circuit receives the primary power output by the power supply interface protection circuit, performs voltage conversion, and outputs a secondary power source to the interface and drive circuit in the product case, the photoelectric sensor, and the overload sensor; The voltage conversion circuit includes a current limiting circuit, a boost / buck circuit, and a diode isolation circuit. The boost / buck circuit selects a TPS series non-isolated DC / DC chip, the input end of each TPS conversion chip is provided with a current limiting circuit, and the output end is isolated by diode series and parallel connection. The boost / buck circuit includes 18 groups according to the number of power supply products and different required voltage values, each group has dual redundancy, and there are 36 voltage conversion circuits in total, which provide +28V main and backup power supply for 6 electromagnetic relays, +15V main and backup power supply for 6 photoelectric sensors, and +5.2V main and backup power supply for 6 overload sensors, and an AMS linear voltage stabilizer is used to convert the +5.2V voltage into a +5V reference voltage for battery power detection and overload sensor power supply.

[0041] The battery power detection circuit compares the battery input voltage with the reference voltage set by the voltage dividing network through an operational amplifier, and indicates the residual power value through four light-emitting diodes.

[0042] The schematic diagram of the photoelectric shaping and electromagnetic drive circuit part is shown in Figure 3 The interface circuit receives the photoelectric sensor signal and sends it to the shaping circuit; in the shaping circuit part, a Schmidt inverter (U1A, U1B, U1C, U1D) is used to perform waveform shaping on the input photoelectric signal, reduce signal noise, and improve anti-interference performance; the shaped waveform is subjected to "AND" operation through a three-input AND gate (U2A, U2B), and only when all the input signals of the AND gate are "1", the output signal is "1", so as to avoid the influence of single signal error; the AND gate output signal is sent to the drive circuit to drive two serially connected NPN transistors (D5, D5), and the paths of U2A, D5 and D6 are in parallel with the paths of U2B, D7 and D8, which play a redundant backup role; when the photoelectric signal is valid, the AND gate output is 1, the NPN transistor is turned on, the relay line package is powered on, the double contacts of the relay are connected, that is, "switch 01-1 output A" and "switch 01-1 output B" are connected, "switch 01-2 output A" and "switch 01-2 output B" are connected, and after the two signals are connected, the return cabin is powered on.

[0043] The internal composition diagram of the non-contact photoionization sensitive system in an embodiment of the application is shown inFigure 1 As shown in the diagram. A schematic diagram of the external connections of the photoionization sensing system is shown below. Figure 4 As shown. Connector X01 connects to 6 photoelectric sensors, each consisting of an emitting LED and a receiving diode, detecting the positional characteristics of objects at a distance by varying the intensity of reflected light. Connector X02 outputs relay switch signals, connecting to the controlled device to be powered. Multiple sets of switch signals are combined in series and parallel to improve the reliability of the system's power-on control. X03 connects to a toggle switch, powering the off-site sensors (photoelectric sensors, overload sensors) and simultaneously displaying the electromechanical status via LEDs. X04 connects to LEDs to display the relay switch status within the off-site sensors, used for system debugging. X05 and X06 connect to a battery, powering the off-site sensing system. X07 enables external communication via a serial port. The microcontroller collects the number of times the electromagnetic relays open and close, storing it in its internal memory, which can be read via the serial port. Interface X08 connects to a thermistor for temperature sampling, and a heating element maintains the system temperature, ensuring system reliability in high-altitude and low-temperature environments.

[0044] The diagram shows the installation and disembarkation of the photoelectric ionization sensing system on the return capsule. Figure 5 As shown, the reentry capsule is placed on the aircraft cabin floor and pushed out of the cabin exit via a sliding rail. After leaving the aircraft, the capsule performs a return maneuver. An optoelectronic off-flight sensing system is installed on the bottom surface of the reentry capsule. An opening in the bottom of the capsule allows the photoelectric sensor to emit infrared light towards the cabin floor, which is diffusely reflected and received by a photodiode. When the reentry capsule is inside the cabin, its bottom surface is close to the floor, resulting in strong reflected light. After the capsule is pushed away from the aircraft, the photoelectric sensor no longer receives the reflected signal, indicating that the capsule has left the aircraft. Furthermore, the off-flight sensing system includes an overload sensor. After leaving the aircraft, the capsule is in a state of weightlessness; the off-flight status is determined by measuring the overload value.

[0045] The working process flow diagram of the photoionization sensing system is as follows: Figure 6 As shown. The photoionization sensor is fixedly installed inside the reentry capsule and connected to the control equipment inside the capsule via an X02 connector. The system connection is tested and confirmed to be correct. Before the reentry capsule is deployed, the power supply switch of the photoionization sensor system is turned on, and the photoionization sensor starts working. After the internal processor determines that the reentry capsule is in an off-plane state based on photoelectric and overload signals, it controls the electromagnetic relay to operate through the internal drive circuit, outputting a power-on start signal to power the control equipment inside the reentry capsule. After the system completes its operation, it is reset and powered off. At the same time, the internal stored information can be read through the serial port to verify the system's operating status.

[0046] The non-contact photoionization sensitive system of the application has the advantages of non-contact sensing measurement, autonomous judgment of the off-machine state and output of a switch control signal, fully considers the reliability and redundancy design of power supply, interface, sensor driving and relay output, has internal and external state monitoring functions, temperature sampling and holding functions, high device integration and ensures the reliability of system power output.

[0047] The application fully considers the reliability of state sensing and power-on control. The photoelectric sensor is used to detect the distance change to reflect the off-machine state of the return capsule, the photoelectric signal is controlled by relay driving after shaping and logic operation, and the power-on control is avoided. At the same time, the overload sensor is used to measure the system overload value to realize the backup judgment of the off-machine state, the overload signal is subjected to low-pass filtering and software sliding window filtering in a hardware circuit, noise is effectively filtered out, and the off-machine judgment accuracy is improved. Redundant backup strategies are adopted on battery power supply, sensor input and relay output control, and the multi-channel signal of the relay output can be combined in series and parallel to improve the reliability of the power-on control system.

[0048] The application uses the photoelectric sensor as the off-machine state detection means, has good high and low temperature resistance and anti-vibration and impact characteristics. In view of the low altitude temperature of the air drop test, the temperature measurement and holding function is integrated, the system temperature control is realized through multiple thermistors and heating sheets, and the system working condition adaptability is improved.

[0049] Although the application has been disclosed as above with a preferred embodiment, it is not intended to limit the application, and any person skilled in the art can make possible changes and modifications to the technical solutions of the application by using the disclosed methods and technical contents without departing from the spirit and scope of the application. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the application, which does not deviate from the technical solutions of the application, belongs to the protection scope of the technical solutions of the application. In the case of no conflict, the embodiments of the application and the technical features in the embodiments can be combined with each other.

[0050] The contents not described in detail in the specification of the application are the known technology of those skilled in the art.

Claims

1. A non-contact photoionization sensing system, characterized in that, include: Photoelectric sensors, interface circuits, shaping circuits, drive circuits, and electromagnetic relays; Photoelectric sensor: Fixedly installed on the off-board structure, it emits infrared light into the cabin wall panel and converts the received reflected light signal into a level signal for output to the interface circuit; Interface circuit: Receives the level signal output by the photoelectric sensor and forwards it to the shaping circuit; Shaping circuit: Receives the level signal forwarded by the interface circuit, performs shaping processing, and outputs it to the drive circuit; Drive circuit: Receives the shaped electrical signal output from the shaping circuit, converts the electrical signal into a control signal for the electromagnetic relay, drives the electromagnetic relay to operate, and powers on the electrical products in the off-machine structure.

2. The non-contact photoionization sensor system according to claim 1, characterized in that, It also includes: a status detection circuit; Status detection circuit: Receives the shaped electrical signal output from the shaping circuit, uses the shaped electrical signal to drive the LED light, and displays the status of the photoelectric sensor signal.

3. The non-contact photoionization sensor system according to claim 1, characterized in that, The interface circuit includes: resistor R1, resistor R2, capacitor C1, and capacitor C2; One end of resistor R1 serves as the input terminal of the interface circuit, receiving the level signal output by the photoelectric sensor; the other end of resistor R1 is connected to the power supply. One end of capacitor C1 is connected to one end of resistor R1, one end of capacitor C2, and one end of resistor R2; The other end of capacitor C1 is connected to the same reference ground as the ground terminal of the photoelectric sensor. The other end of capacitor C1 is grounded. The other end of capacitor C2 is connected to the other end of capacitor C1 and the other end of resistor R2. One end of resistor R2 serves as the output of the interface circuit and is connected to the input of the shaping circuit.

4. The non-contact photoionization sensitive system according to claim 3, characterized in that, The shaping circuit includes: a first AND gate logic device U2A, a second AND gate logic device U2B, resistors R3, R4, R5, R6, R7, and R8, capacitors C3, C4, C5, C6, C7, C8, C9, and C10, a first inverter U1A, a second inverter U1B, a third inverter U1C, and a fourth inverter U1D; The input terminal of the first inverter U1A is used as the input terminal of the shaping circuit and is connected to one end of the resistor R2; The input terminal of the second inverter U1B is connected to the input terminal of the first inverter U1A, the input terminal of the third inverter U1C, and the input terminal of the fourth inverter U1D. The output of the first inverter U1A is connected to one end of the resistor R3, and the other end of the resistor R3 is connected to one end of the capacitor C3 and the first input of the first AND gate logic device U2A. The other end of the capacitor C3 is grounded. The output of the second inverter U1B is connected to one end of resistor R4, the other end of resistor R4 is connected to one end of capacitor C4 and the second input of the first AND gate logic device U2A, and the other end of capacitor C4 is grounded. The power supply terminal of the first AND gate logic device U2A is connected to one end of resistor R7, and the other end of resistor R7 is connected to the power supply; one end of resistor R7 is connected to one end of capacitor C7 and one end of capacitor C8; the other ends of capacitor C7 and the other ends of capacitor C8 are grounded. The output terminal of the third inverter U1C is connected to one end of the resistor R5, the other end of the resistor R5 is connected to one end of the capacitor C5 and the first input terminal of the second AND gate logic device U2B, and the other end of the capacitor C5 is grounded. The output of the fourth inverter U1D is connected to one end of resistor R6, the other end of resistor R6 is connected to one end of capacitor C6 and the second input of the second AND gate logic device U2B, and the other end of capacitor C6 is grounded. The power supply terminal of the second AND gate logic device U2B is connected to one end of resistor R8, and the other end of resistor R8 is connected to the power supply; one end of resistor R8 is connected to one end of capacitor C9 and one end of capacitor C10; the other ends of capacitor C9 and the other ends of capacitor C10 are grounded. The output terminals of the first AND gate U2A and the second AND gate U2B serve as the output terminals of the shaping circuit and are connected to the input terminals of the driving circuit.

5. A non-contact photoionization sensor system according to claim 4, characterized in that, The driving circuit includes: diodes D1, D2, D3, and D4; resistors R11, R12, R13, R14, R15, and R16; capacitors C11 and C12; NPN transistors D5, D6, D7, and D8. The anodes of diodes D1 and D2 serve as the input terminals of the drive circuit, connected to the output terminal of the first AND gate logic device U2A; The cathode of diode D1 is connected to one end of resistor R9; the other end of resistor R9 is connected to one end of resistor R11 and the base of NPN transistor D5; the other end of resistor R11 is connected to the emitter of NPN transistor D5. The cathode of diode D2 is connected to one end of resistor R10; the other end of resistor R10 is connected to one end of resistor R12, one end of capacitor C11, and the base of NPN transistor D6; the other end of capacitor C11 is grounded; the other end of resistor R12 is connected to the other end of capacitor C11 and the emitter of NPN transistor D6; the collector of NPN transistor D6 is connected to the other end of resistor R11. The anodes of diode D3 and diode D4 serve as the input terminals of the drive circuit, connected to the output terminal of the second AND gate logic device U2B; The cathode of diode D3 is connected to one end of resistor R13; the other end of resistor R13 is connected to one end of resistor R14 and the base of NPN transistor D7; the other end of resistor R14 is connected to the emitter of NPN transistor D7. The cathode of diode D4 is connected to one end of resistor R15; the other end of resistor R15 is connected to one end of resistor R16, one end of capacitor C12, and the base of NPN transistor D8; the other end of capacitor C12 is grounded; the other end of resistor R16 is connected to the other end of capacitor C12 and the emitter of NPN transistor D8; the collector of NPN transistor D8 is connected to the other end of resistor R14. The collectors of NPN transistor D5 and NPN transistor D7 serve as the output terminals of the drive circuit, outputting the control signal of the electromagnetic relay to the electromagnetic relay.

6. A non-contact photoionization sensitive system according to any one of claims 3-5, characterized in that, Also includes: Microcontroller circuit, overload sensor and overload filter follower circuit; Overload sensor: measures the overload value of the off-machine structure and generates an overload sensor signal output to the interface circuit; Interface circuit: forwards the received overload sensor signal to the overload filter follower circuit; Overload filter follower circuit: Receives the overload sensor signal forwarded by the interface circuit, performs filtering processing, and outputs the filtered electrical signal to the microcontroller circuit. The microcontroller circuit receives the filtered electrical signal from the overload filter follower circuit, determines that the off-machine structure is in a weightless state, and then outputs a control signal to the drive circuit. Drive circuit: Receives control signals output from the microcontroller circuit, converts the control signals into control signals for the electromagnetic relay, drives the electromagnetic relay to operate, and enables the electrical products in the off-machine structure to be powered on.

7. A non-contact photoionization sensor system according to claim 6, characterized in that, Also includes: Temperature sampling heating circuit and chassis; The interface circuit, shaping circuit, driving circuit, microcontroller circuit, overload filtering and following circuit, and temperature sampling and heating circuit are all fixed inside the chassis, which is fixedly installed on the off-machine structure. The microcontroller circuit obtains the temperature sampling signal and outputs a thermal control signal to the temperature sampling heating circuit. Temperature sampling heating circuit: Receives the thermal control signal output by the microcontroller circuit, and controls the heating element to heat the chassis by driving the field-effect transistor.

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