A rotor speed signal processor with dual mode criteria

Abstract

The application discloses a rotor rotating speed signal processor with a dual-mode criterion, which comprises a power supply circuit board and a processing circuit board. The rotor rotating speed signal processor collects the frequency signal of a rotor rotating speed magnetic sensor, and provides an alarm signal of high rotor rotating speed or low rotor rotating speed to an alarm module and an electromechanical management system after processing the sensor signal. The mode criterion signal input to the electromechanical management system can change the rotor rotating speed qualified criterion, realize the dual judgment of the rotor rotating speed qualification in the helicopter mode and the fixed-wing mode, and the power supply module adopts multiple filter units and multiple energy storage units. The problems of the existing rotor rotating speed signal processor, such as the inability to realize the dual judgment of the rotor rotating speed qualification in the helicopter mode and the fixed-wing mode, the high precision and the anti-EMI problem of the frequency and voltage conversion in the dual mode, are solved. The frequency value of the aircraft rotor rotating speed is accurately and truly reflected, and the anti-EMI capability of the processor and the overall reliability of the system are improved.

Description

Technical Field

[0001] This invention belongs to the field of rotor control technology, and particularly relates to a rotor speed signal processor with dual-mode criteria. Background Technology

[0002] The rotor speed signal processor is a core system ensuring the safe operation of the rotorcraft's power system, and its technological evolution is closely linked to the development of avionics systems. Early speed monitoring used mechanical centrifugal governors, which were limited by response speed and accuracy and were gradually replaced by electronic systems. In the 1990s, digital processors based on Hall effect sensors became mainstream, calculating speed through pulse frequency measurement. A typical architecture included analog front-end conditioning circuitry and an 8-bit microcontroller, but its electromagnetic interference resistance was insufficient, resulting in a high false alarm rate under complex operating conditions.

[0003] With the increasing demand for avionics integration, its technological development focuses on high reliability, real-time performance and environmental robustness. Modern designs adopt mixed-signal design, integrate high-precision timers and hardware CRC check units to shorten response time, and use threshold comparison algorithms combined with speed gradient prediction signal processing algorithms to achieve speed signal protection and improve processor reliability.

[0004] Furthermore, the weak signal from the magnetic sensor acquired by the rotor speed signal processor is easily overwhelmed by electromagnetic noise and susceptible to power supply noise interference, leading to electromagnetic interference (EMI) problems. This ultimately results in glitch, jump, or loss of the speed signal, making it difficult to achieve dual-mode rotor speed qualification for both helicopter and fixed-wing modes, as well as high-precision frequency and voltage conversion in both modes, and to address EMI issues. Therefore, there is an urgent need to provide a rotor speed signal processor with dual-mode criteria to solve the aforementioned technical problems. Summary of the Invention

[0005] In view of this, the present invention provides a rotor speed signal processor with dual-mode criteria, which can accurately and truly reflect the frequency value of the aircraft rotor speed, improve the processor's anti-EMI capability, and enhance the overall reliability of the system. The specific technical solution adopted is as follows.

[0006] The present invention provides a rotor speed signal processor with dual-mode criteria. The rotor speed signal processor includes a housing, a power circuit board disposed at the bottom of the housing, an inter-board connector disposed on the power circuit board, and a processing circuit board located on the inter-board connector. An electrical connector for connecting multiple rotor speed magnetic sensors is disposed on the side of the housing.

[0007] The power circuit board includes a power module and a voltage adjustment module. The power module includes a rectifier unit, a first energy storage unit, a first filter unit, and a second energy storage unit for connecting to the power input terminal. The first energy storage unit and the first filter unit are both connected to the rectifier unit. The first filter unit is connected to one end of the second energy storage unit, and the other end of the second energy storage unit is connected to the voltage adjustment module.

[0008] The processing circuit board includes a detection module connected to multiple rotor speed magnetic sensors, a main control module connected to the detection module, an alarm module, and a mode criterion signal input module. The voltage adjustment module, the alarm module, and the mode criterion signal input module are all connected to the main control module. The mode criterion signal input module is used to connect to the motor management system and receive the mode criterion signal from the motor management system.

[0009] The power supply module and the voltage adjustment module are used to supply power to the main control module. The main control module controls the detection module to detect the connection status between the rotor speed magnetic sensor and the rotor speed signal processor, and receives the speed acquisition signal and the mode criterion signal from the rotor speed magnetic sensor according to the connection status. The main control module processes the speed acquisition signal and the mode criterion signal and controls the alarm module to turn on and off.

[0010] As a preferred embodiment of the above technical solution, the voltage adjustment module includes a DC-DC converter, a second filter unit, and a low-dropout three-terminal voltage regulator connected to the second energy storage unit. One end of the second filter unit is connected to the DC-DC converter, and the other end of the second filter unit is connected to the low-dropout three-terminal voltage regulator. The low-dropout three-terminal voltage regulator is connected to the main control module.

[0011] As a preferred embodiment of the above technical solution, the rectifier unit includes a diode D19, the first energy storage unit includes a capacitor C48, and the first filter unit includes a common-mode rejection inductor T1, a capacitor C36, a capacitor C37, and a filter IC11. The anode of the diode D19 is connected to the power input terminal, the cathode of the diode D19 is connected to one end of the capacitor C48 and the common-mode rejection inductor T1, and the other end of the common-mode rejection inductor T1 is connected to the capacitors C36 and C37 respectively. Both the capacitors C36 and C37 are connected to the filter IC11.

[0012] The second energy storage unit includes capacitors C38, C39, and C40, diodes D20 and D21, and resistor R38. The anode of diode D20, capacitors C38 and C39 are all connected to filter IC11, and the cathode of diode D21 is connected to the cathode of resistor R38, capacitor C40, and diode D21.

[0013] The DC-DC converter includes chip IC10. The second filter unit includes capacitors C41, C42, C43, C44, C45, C46, ​​and C47. Capacitors C41 and C42 are connected in parallel, C43 and C44 are connected in parallel, and C46 and C47 are connected in parallel to chip IC10. The low dropout three-terminal voltage regulator includes chip IC12, capacitors C49, C50, C51, and C52. Capacitors C49, C50, C51, and C52 are connected in parallel to chip IC12.

[0014] As a preferred embodiment of the above technical solution, both the first energy storage unit and the second energy storage unit use high-energy tantalum capacitors, and the capacitance values ​​of capacitors C41, C43 and C46 are greater than the capacitance values ​​of capacitors C36, C37, C39, C40, C42, C44, C45 and C47.

[0015] As a preferred embodiment of the above technical solution, the detection module includes a self-test signal switching circuit connected to the rotor speed magnetic sensor and a filter circuit, an amplification circuit, and a clamping circuit connected in sequence. The filter circuit and the main control module are both connected to the self-test signal switching circuit.

[0016] The self-test signal switching circuit is used to perform a power-on BIT test on the rotor speed magnetic sensor. The filtering circuit is used to filter the input frequency signal of the self-test signal switching circuit. The amplification circuit is used to amplify the filtered signal and shape the amplified signal into a square wave signal. The clamping circuit is used to process the square wave signal and send it to the main control module.

[0017] As a preferred embodiment of the above technical solution, the alarm module includes an alarm switch circuit connected to the main control module and an alarm control light box connected to the alarm switch circuit. The alarm switch circuit includes a relay, a diode, and an inductor. The alarm switch circuit is used to receive the output level of the main control module.

[0018] When the clamping circuit clamps the level of the square wave signal to the input range of the main control module, the main control module performs calculations on the speed acquisition signal corresponding to the input frequency signal to obtain the corresponding speed input signal.

[0019] The main control module performs judgment processing based on the speed input signal and the mode criterion signal to obtain the output level. The main control module controls the alarm control light box to turn on and off through the alarm switch circuit based on the output level. The mode criterion signal includes fixed-wing mode criterion, helicopter and transition mode criterion.

[0020] As a preferred embodiment of the above technical solution, the mode judgment signal input module includes an RS422 communication circuit connected to the main control module. The RS422 communication circuit is used to transmit the speed value processed by the main control module to the motor management system and to send the mode judgment signal of the motor management system to the main control module.

[0021] As a preferred embodiment of the above technical solution, the main control module controls the detection module to detect the connection status between the rotor speed magnetic sensor and the rotor speed signal processor, including:

[0022] The main control module sends a power-on self-test command to the detection module, and the detection module checks whether there is a signal input at the input interface of the rotor speed magnetic sensor;

[0023] If there is no signal input, the main control module sets the input frequency self-test signal to control the rotor speed magnetic sensor to connect to the speed measurement channel. The main control module receives the speed acquisition signal from the speed measurement channel, performs calculations, and determines whether the speed measurement channel is normal. Each rotor speed magnetic sensor includes one speed measurement channel.

[0024] If normal, the main control module selects the acquisition frequency corresponding to the rotor speed acquisition signal according to the lowest measurement frequency of the rotor speed magnetic sensor. The acquisition frequency is determined by the frequency signal change rate based on the engine speed change rate and calculated using a threshold comparison algorithm and a speed gradient prediction algorithm.

[0025] As a preferred embodiment of the above technical solution, the detection module is further used to detect the input level of the AD interface of the main control module to determine whether the power supply of the main control module is normal.

[0026] If normal, the detection module is also used to detect and compare the received and transmitted data of the communication interface of the main control module to determine whether the communication interface of the main control module is normal.

[0027] As a preferred embodiment of the above technical solution, the rotor speed signal processor further includes a cover plate and a limiting component disposed on the housing. The limiting component includes a flat washer disposed on the side of the housing, a spring washer fitted to the flat washer, and a pan head screw. One end of the pan head screw is connected to the electrical connector, and the other end of the pan head screw is used to fix the spring washer and the flat washer.

[0028] This invention provides a rotor speed signal processor with dual-mode criteria. By setting up a power supply circuit board and a processing circuit board on the rotor speed signal processor, the rotor speed signal processor collects the frequency signal of the rotor speed magnetic sensor, processes the sensor signal, and provides alarm signals for high or low rotor speed to the alarm module and electromechanical management system. The addition of a mode criteria signal input module to the electromechanical management system can change the rotor speed qualification criteria, realizing dual judgment of rotor speed qualification in helicopter mode and fixed-wing mode. The power supply module adopts multiple filtering units and multiple energy storage units, which solves the problems of existing rotor speed signal processors that cannot realize dual judgment of rotor speed qualification in helicopter mode and fixed-wing mode, high accuracy of frequency and voltage conversion in dual-mode, and anti-EMI problems. It can accurately reflect the frequency value of aircraft rotor speed, improve the processor's anti-EMI capability, and enhance the overall reliability of the system. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a structural block diagram of the rotor speed signal processor provided by the present invention;

[0031] Figure 2 A schematic diagram of the rotor speed signal processor provided by the present invention;

[0032] Figure 3 The circuit schematic of the rotor speed signal processor provided by the present invention;

[0033] Figure 4 A circuit diagram of a power supply circuit board provided for this invention;

[0034] Figure 5 This is a structural block diagram of the voltage adjustment module provided by the present invention;

[0035] Figure 6 This is a structural block diagram of the detection module provided by the present invention;

[0036] Figure 7 The main workflow diagram of the rotor speed signal processor provided by the present invention is shown.

[0037] The symbols for the main components are explained below:

[0038] 10-Housing; 20-Power supply circuit board; 30-Inter-board connector; 40-Processing circuit board; 50-Electrical connector; 60-Power supply module; 70-Voltage adjustment module; 80-Rectifier unit; 90-First energy storage unit; 100-First filter unit; 110-Second energy storage unit; 120-Detection module; 130-Main control module; 140-Alarm module; 150-Mode criterion signal input module; 160-DC-DC converter; 170-Second filter unit; 180-Low drop three-terminal voltage regulator; 190-Self-test signal switching circuit; 200-Filter circuit; 210-Amplifier circuit; 220-Clamping circuit; 230-Cover plate; 240-Limiting component; 250-Pan head screw; 260-Nut; 270-Conductive rubber ring; 280-Counterhead screw. Detailed Implementation

[0039] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0040] It should be noted that when an element is said to be "fixed" to another element, it can be directly on the other element or there may be an intervening element. When an element is said to be "connected" to another element, it can be directly connected to the other element or there may be an intervening element. Conversely, when an element is said to be "directly" on another element, there is no intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0041] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0042] To add a speed criterion switching function to the rotor speed signal processor, a single RS422 communication channel is used for full-duplex communication. For switching between "helicopter and transition mode" and "fixed-wing mode" commands, the rotor speed signal processor prioritizes data from the RS422 communication interface. If a communication failure occurs, discrete commands (corresponding to...) are then used. Figure 3The switching signals of the fixed-wing mode criterion and the helicopter and transient mode criterion are used to balance data real-time performance and ensure functional safety and integrity. Common-mode suppression inductors, EMI filters and filter capacitors are added to the power circuit board to improve EMI immunity.

[0043] See Figure 1 , Figure 2 and Figure 3 The present invention provides a rotor speed signal processor with dual-mode criteria. The rotor speed signal processor includes a housing 10, a power circuit board 20 disposed at the bottom of the housing 10, an inter-board connector 30 disposed on the power circuit board 20, and a processing circuit board 40 located on the inter-board connector 30. An electrical connector 50 for connecting multiple rotor speed magnetic sensors is disposed on the side of the housing 10.

[0044] The power circuit board 20 includes a power module 60 and a voltage adjustment module 70. The power module 60 includes a rectifier unit 80, a first energy storage unit 90, a first filter unit 100, and a second energy storage unit 110 for connecting to the power input terminal. The first energy storage unit 90 and the first filter unit 100 are both connected to the rectifier unit 80. The first filter unit 100 is connected to one end of the second energy storage unit 110, and the other end of the second energy storage unit 110 is connected to the voltage adjustment module 70.

[0045] The processing circuit board 40 includes a detection module 120 connected to multiple rotor speed magnetic sensors, a main control module 130, an alarm module 140, and a mode criterion signal input module 150 connected to the detection module 120. The voltage adjustment module 70, the alarm module 140, and the mode criterion signal input module 150 are all connected to the main control module 130. The mode criterion signal input module 150 is used to connect to the motor management system and receive the mode criterion signal from the motor management system.

[0046] The power supply module 60 and the voltage adjustment module 70 are used to supply power to the main control module 130. The main control module 130 controls the detection module 120 to detect the connection status between the rotor speed magnetic sensor and the rotor speed signal processor, and receives the speed acquisition signal and the mode criterion signal from the rotor speed magnetic sensor according to the connection status. The main control module 130 processes the speed acquisition signal and the mode criterion signal and controls the alarm module 140 to turn on and off.

[0047] In this embodiment, the rotor speed signal processor further includes a cover plate 230 and a limiting component 240 disposed on the housing 10. The limiting component 240 includes a flat washer disposed on the side of the housing 10, a spring washer fitted to the flat washer, and a pan head screw 250. One end of the pan head screw 250 is connected to the electrical connector 50, and the other end of the pan head screw 250 is used to fix the spring washer and the flat washer. The pan head screw 250 is fixedly installed to the side of the housing 10 by a nut 260. The cover plate 230 is fixedly installed to the housing 10 by a countersunk screw 280. The electrical connector 50 is connected to the power circuit board 20 or the processing circuit board 40 inside the housing 10 by a conductive rubber ring 270. The rotor speed signal processor contains two circuit boards: a power supply circuit board 20 and a processing circuit board 40. The power supply circuit board 20 serves as an EMI suppressor; the power output from it is the processed power. The power supply circuit board 20 mainly consists of a common-mode rejection inductor T1 and a filter with DC surge protection (EMI filter). Figure 4 The system consists of IC11, energy storage capacitors, a DC-DC converter, and filter capacitors. A common-mode rejection inductor T1 at the positive input terminal suppresses differential-mode interference signals. A rectifier diode D19 ensures that the product (rotor speed signal processor) will not be damaged by current input when the power input polarity is reversed. Simultaneously, when the product loses power or lacks input power, the internal energy storage capacitor C48 discharges without feedback to the onboard power grid. EMI filters and resistive capacitor components (a combination of resistor R38 and capacitor C38) are used to filter both the primary and secondary power supplies, reducing mutual interference between the onboard power supply and the rotor speed signal processor to meet the product's electromagnetic compatibility requirements.

[0048] It should be noted that, upon rereading Figure 4 and Figure 5 The voltage adjustment module 70 includes a DC-DC converter 160, a second filter unit 170, and a low-dropout three-terminal voltage regulator 180, all connected to the second energy storage unit 110. One end of the second filter unit 170 is connected to the DC-DC converter 160, and the other end is connected to the low-dropout three-terminal voltage regulator 180. The low-dropout three-terminal voltage regulator 180 is connected to the main control module 130. The rectifier unit 80 includes a diode D19. The first energy storage unit 90 includes a capacitor C48. The first filter unit 100 includes a common-mode rejection inductor T1, capacitors C36 and C37, and a filter IC11. The anode of the diode D19 is connected to the power input terminal. The cathode of the diode D19 is connected to capacitor C48 and one end of the common-mode rejection inductor T1. The other end of the common-mode rejection inductor T1 is connected to capacitors C36 and C37, respectively. Both capacitors C36 and C37 are connected to the filter IC11.

[0049] The second energy storage unit 110 includes capacitors C38, C39, and C40, diodes D20 and D21, and resistor R38. The anode of diode D20, capacitors C38 and C39 are all connected to filter IC11, and the cathode of diode D21 is connected to resistor R38, capacitor C40, and the cathode of diode D21.

[0050] The DC-DC converter 160 includes a chip IC10. The second filter unit 170 includes capacitors C41, C42, C43, C44, C45, C46, ​​and C47. Capacitors C41 and C42 are connected in parallel, capacitors C43 and C44 are connected in parallel, and capacitors C46 and C47 are connected in parallel to the chip IC10. The low dropout three-terminal voltage regulator 180 includes a chip IC12, capacitors C49, C50, C51, and C52. Capacitors C49, C50, C51, and C52 are connected in parallel to the chip IC12.

[0051] Both the first energy storage unit 90 and the second energy storage unit 110 use high-energy tantalum capacitors. The capacitance values ​​of capacitors C41, C43, and C46 are greater than those of capacitors C36, C37, C39, C40, C42, C44, C45, and C47. A filter (ZMEMI type IC11) is selected. This filter has an input voltage range of 0V to 50V, a maximum surge voltage of 80V / 50ms, and a common-mode insertion loss of 35dB / 500KHz. The filter capacitor is 10uF (…). Figure 4 C41, C43, C46) and 0.01uF ( Figure 4 C36, C37, C39, C40, C42, C44, C45, and C47 are used as input filter capacitors to effectively filter out low-frequency and high-frequency interference in the circuit. Figure 4 In this context, Positive Input indicates the positive input terminal, Input Common indicates the input common, Case Ground indicates the case ground, Main(+5) Output indicates the main output +5V voltage, Pos.Aux.Output indicates the positive auxiliary output, Output Common indicates the output common, and Neg.Aux.Output indicates the negative auxiliary output.

[0052] The energy storage capacitor (C38) is a high-energy tantalum capacitor (THCL type). This capacitor can provide power to the product when the external power supply fails, allowing the product to operate normally even with a 50ms power outage. Due to the large capacitance of the capacitor, the charging current is too high, therefore a slow-charge and fast-discharge control circuit (tantalum capacitor C38 can achieve the function of slow-charge and fast-discharge) is required to prevent the system power supply from being impacted at the moment of power-on. A DC-DC converter (ZHF type) is selected. Figure 4 The IC10 in the circuit provides a stable power supply for the rotor speed signal processor, supporting 16V~48V input, +5V, ±15V output, and a power of 15W. The power module 60 is manufactured using a thick-film hybrid integrated process and encapsulated in a fully sealed metal shell. It features input undervoltage, disable, and short-circuit protection, and can withstand 80V / 1s surges, meeting product design requirements. It uses 10uF output filter capacitors (C41, C43, C46) to effectively filter out low-frequency and high-frequency interference in the circuit. The DCDC converter 160 outputs the +5V circuit through a low-dropout three-terminal voltage regulator 180 (…). Figure 4 IC12 in the chip converts the output to +3.3V, which powers the main control module 130 and the level conversion chip. Among them, chip IC10 converts 28V to +5V (pin 2) and outputs ±15V (pins 4 and 5); chip IC12 can be a level conversion chip, which converts +5V to +3.3V.

[0053] It should be understood that by setting up a power circuit board 20 and a processing circuit board 40 on the rotor speed signal processor, the rotor speed signal processor collects the frequency signal of the rotor speed magnetic sensor, processes the sensor signal, and provides alarm signals for high or low rotor speed to the alarm module 140 and the electromechanical management system. The addition of a mode judgment signal input module 150 to the electromechanical management system can change the rotor speed qualification judgment, realizing dual judgment of rotor speed qualification in helicopter mode and fixed-wing mode. The power module 60 adopts multiple filtering units and multiple energy storage units, which solves the problems of existing rotor speed signal processors that cannot realize dual judgment of rotor speed qualification in helicopter mode and fixed-wing mode, as well as the high accuracy of frequency and voltage conversion in dual mode and the anti-EMI problem. It can accurately and truly reflect the frequency value of the aircraft rotor speed, improve the processor's anti-EMI capability, and enhance the overall reliability of the system.

[0054] Optionally, the detection module 120 includes a self-test signal switching circuit 190 connected to the rotor speed magnetic sensor and a filter circuit 200, an amplifier circuit 210 and a clamping circuit 220 connected in sequence. The filter circuit 200 and the main control module 130 are both connected to the self-test signal switching circuit 190.

[0055] The self-test signal switching circuit 190 is used to perform a power-on BIT test on the rotor speed magnetic sensor. The filtering circuit 200 is used to filter the input frequency signal of the self-test signal switching circuit 190. The amplification circuit 210 is used to amplify the filtered signal and shape the amplified signal into a square wave signal. The clamping circuit 220 is used to process the square wave signal and send it to the main control module 130.

[0056] In this embodiment, see Figure 6 The alarm module 140 includes an alarm switch circuit connected to the main control module 130 and an alarm control light box connected to the alarm switch circuit. The alarm switch circuit includes a relay, a diode, and an inductor. The alarm switch circuit is used to receive the output level of the main control module 130. When the clamping circuit 220 clamps the level of the square wave signal to the input range of the main control module 130, the main control module 130 performs calculation processing on the speed acquisition signal corresponding to the input frequency signal to obtain the corresponding speed input signal. The main control module 130 performs judgment processing based on the speed input signal and the mode criterion signal to obtain the output level. The main control module 130 controls the alarm control light box to turn on and off through the alarm switch circuit based on the output level. The mode criterion signal includes fixed-wing mode criterion, helicopter mode criterion, and transition mode criterion. The mode judgment signal input module 150 includes an RS422 communication circuit connected to the main control module 130. The RS422 communication circuit is used to transmit the speed value processed by the main control module 130 to the motor management system and send the mode judgment signal of the motor management system to the main control module 130. The electromechanical management system can store and manage the speed, frequency, etc. of the engine, motor, etc., and the alarm control light box can include a buzzer, indicator light, etc.

[0057] It should be noted that the main control module 130 controls the detection module 120 to detect the connection status between the rotor speed magnetic sensor and the rotor speed signal processor, including: the main control module 130 sends a power-on self-test command to the detection module 120; the detection module 120 detects whether there is a signal input at the input interface of the rotor speed magnetic sensor; if there is no signal input, the main control module 130 sets an input frequency self-test signal to control the rotor speed magnetic sensor to connect to the speed measurement channel; the main control module 130 receives the speed acquisition signal from the speed measurement channel, performs calculations, and determines whether the speed measurement channel is normal. Each rotor speed magnetic sensor includes one speed measurement channel. If normal, the main control module 130 selects the acquisition frequency corresponding to the speed acquisition signal according to the lowest measurement frequency of the rotor speed magnetic sensor. The acquisition frequency is determined based on the engine speed change rate and calculated using a threshold comparison algorithm and a speed gradient prediction algorithm.

[0058] The detection module 120 is also used to detect the input level of the AD interface of the main control module 130 to determine whether the power supply of the main control module 130 is normal.

[0059] If normal, the detection module 120 is also used to detect and compare the received data and sent data of the communication interface of the main control module 130 to determine whether the communication interface of the main control module 130 is normal.

[0060] Specifically, the main control module 130 can be a microprocessor (MCU), and the processing circuit board 40 mainly consists of a disconnection detection circuit (not shown), a self-test signal switching circuit 190, a port protection circuit, a filter circuit 200, an amplifier circuit 210, a clamping circuit 220, a microprocessor (main control module 130), an alarm switch circuit, and a mode criterion signal input module 150 (which can be implemented through an RS422 communication circuit). The self-test signal switching circuit 190 is mainly used for the product's power-on BIT test (internal self-test). After the product is powered on, under the condition of no speed signal input, the power-on self-test program is started, and the microprocessor sends a control signal to switch the level signal. The high-level signal output from the MCU's I / O port is connected to the connection circuit between the sensor (rotor speed magnetic sensor) and the product. By detecting its level signal, the connection between the product (rotor speed signal processor) and the sensor is checked for any disconnection. At the same time, the standard frequency signal (PWM signal) is connected to the product's speed measurement circuit (channel). The acquired signal is compared with the standard signal (PWM signal) to determine whether the product's speed acquisition channel (there is only one speed acquisition channel for one rotor speed magnetic sensor) is working properly. The detection information is then sent to the electromechanical management system through the communication interface circuit (port protection circuit and RS422 communication circuit).

[0061] The aforementioned detection information mainly includes whether the rotational speed acquisition channel is normal, whether the acquisition signal of the rotational speed acquisition channel and the sensor connection are normal, etc. The port protection circuit is the interface for impedance matching and external impact protection with the rotor speed magnetic sensor. It does not affect the signal amplitude output by the sensor. The port protection circuit and the communication port protection circuit establish the communication connection between various circuits or hardware modules. According to the input signal, after passing through the low-pass filter circuit, the low-pass filter circuit (filter circuit) can effectively filter out high-frequency interference signals. Then, after passing through the amplifier circuit 210, the signal is appropriately amplified and the signal is shaped into a square wave signal for subsequent circuit processing. Then, after the clamping circuit 220 limits the amplitude protection to control the voltage of the square wave signal (the processed rotor speed magnetic sensor signal) within the range that the microprocessor can accept.

[0062] Specifically, the filter circuit 200 (low-pass filter) is mainly used to filter the input frequency signal (the signal fed back from the self-test signal switching circuit) to suppress high-frequency and low-frequency interference in the input signal; the clamping circuit 220 is mainly used to clamp the (square wave signal) level to the microprocessor input range; the microprocessor is used to process the conditioned speed signal (according to) and, based on the input mode criterion signal and the converted value of the speed input signal, to control the alarm switch circuit to issue a high speed alarm or a low speed alarm. The alarm switch circuit (low-speed alarm output, high-speed alarm output) is mainly composed of a relay, a diode, and an inductor. It conducts when receiving a high level from the microprocessor and outputs a low level to trigger an alarm; it disconnects when the received signal is low and outputs a high level; the mode criterion signal input module 150 (circuit) mainly receives and converts the mode criterion signal ("fixed-wing mode criterion" and "helicopter and transition mode criterion") for easy reading by the microprocessor interface. The communication circuit consists of an RS422 communication circuit, which is mainly used to transmit the speed value processed by the microprocessor to the electromechanical management system, and to receive the mode judgment signal to the product's microprocessor.

[0063] In one feasible embodiment, the rotor speed signal processor requires software design, which includes error prevention, high reliability, and high security. The software program is stored in the microprocessor's memory and can run automatically upon power-on. It mainly performs functions such as power-on self-test, signal acquisition, communication interface, measurement channel switching, fault detection, digital output, and periodic self-test. The specific execution process is as follows:

[0064] S1: During the power-on self-test, the sensor connection is checked by detecting sensor disconnection. It checks if there is a signal at the sensor input interface; if no signal is received, it sets the input frequency self-test signal to the measurement channel (speed measurement channel), processes the measurement data (speed signal), and determines if the measurement channel is functioning correctly.

[0065] S2: Determine the minimum measurement frequency based on the sensor's synchronization requirements (the software program specifies that the frequency value corresponding to speeds below 6% is 0, which is the minimum measurement frequency), and select a suitable acquisition frequency (the acquisition frequency is the minimum measurement frequency × 0xFFFF) to improve algorithm efficiency; determine the frequency signal change rate based on the engine speed change rate (e.g., 20% rpm / s) to eliminate signal jitter; select a suitable filtering algorithm (threshold comparison algorithm combined with speed gradient prediction) based on the input signal frequency value to ensure the real-time performance of the output data;

[0066] S3: During the periodic self-test, the input level of the AD interface (analog-to-digital converter) of the microprocessor (MCU) is detected in real time to determine whether the working power supply (±15V, 5V) is normal; the received data and transmitted data of the communication interface (circuit) are compared to determine whether the communication interface is normal.

[0067] S4: To prevent software crashes, an on-chip watchdog timer is set in the software. The watchdog timer reset is set to 1 second, so that the software can be reliably reset after a crash.

[0068] In this embodiment, during the initialization of the underlying layer, the sensor coil receives a self-test command, the measurement channel executes the self-test command, and after the self-test sensor is working normally, it is necessary to test the speed measurement channel (speed measurement, converted into digital signal output) to determine whether the rate of change of speed is higher than 102%.

[0069] If so, then a high output speed alarm will be triggered;

[0070] If not, determine whether the input mode criterion signal is a fixed-wing mode;

[0071] If it is a fixed-wing mode, then determine whether the current rate of change of rotational speed is below 83%;

[0072] If so, output a low speed alarm (warning).

[0073] If not, return to continue measuring the rotational speed;

[0074] If it is not in fixed-wing mode, then determine whether the current rate of change of rotational speed is below 96%;

[0075] If so, output a low speed alarm (warning).

[0076] If not, return to continue measuring the rotational speed.

[0077] The system periodically sends digital information (signals) to the electromechanical management system, and periodically sends digital information to the alarm system after a power outage. The rotor speed signal processor provided by this invention employs dual judgment of rotor speed qualification in both helicopter and fixed-wing modes, integrates a high-precision timer and hardware CRC check unit, which can shorten the response time, and uses a threshold comparison algorithm (…). Figure 7 The signal processing algorithm, which combines the comparison and judgment of three rotational speed values ​​with the prediction of rotational speed gradient (interval values ​​of the three rotational speed values), realizes rotational speed signal protection and improves processor reliability. It solves the problem of dual judgment of rotor speed in helicopter mode and fixed-wing mode from the source, and achieves high accuracy of frequency and voltage conversion and anti-EMI in dual-mode. It is convenient to balance the realization of data real-time performance and ensure functional safety and integrity.

[0078] In all examples shown and described herein, any specific values ​​should be interpreted as merely exemplary and not as limitations; therefore, other examples of exemplary embodiments may have different values.

[0079] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0080] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A rotor speed signal processor with dual-mode criteria, characterized in that, The rotor speed signal processor includes a housing, a power circuit board disposed at the bottom of the housing, an inter-board connector disposed on the power circuit board, and a processing circuit board located on the inter-board connector. An electrical connector for connecting multiple rotor speed magnetic sensors is disposed on the side of the housing. The power circuit board includes a power module and a voltage adjustment module. The power module includes a rectifier unit, a first energy storage unit, a first filter unit, and a second energy storage unit for connecting to the power input terminal. The first energy storage unit and the first filter unit are both connected to the rectifier unit. The first filter unit is connected to one end of the second energy storage unit, and the other end of the second energy storage unit is connected to the voltage adjustment module. The processing circuit board includes a detection module connected to multiple rotor speed magnetic sensors, a main control module connected to the detection module, an alarm module, and a mode criterion signal input module. The voltage adjustment module, the alarm module, and the mode criterion signal input module are all connected to the main control module. The mode criterion signal input module is used to connect to the motor management system and receive the mode criterion signal from the motor management system. The power supply module and the voltage adjustment module are used to supply power to the main control module. The main control module controls the detection module to detect the connection status between the rotor speed magnetic sensor and the rotor speed signal processor, and receives the speed acquisition signal and the mode criterion signal from the rotor speed magnetic sensor according to the connection status. The main control module processes the speed acquisition signal and the mode criterion signal and controls the alarm module to turn on and off.

2. The rotor speed signal processor with dual-mode criteria according to claim 1, characterized in that, The voltage adjustment module includes a DC-DC converter, a second filter unit, and a low-dropout three-terminal voltage regulator connected to the second energy storage unit. One end of the second filter unit is connected to the DC-DC converter, and the other end of the second filter unit is connected to the low-dropout three-terminal voltage regulator. The low-dropout three-terminal voltage regulator is connected to the main control module.

3. The rotor speed signal processor with dual-mode criteria according to claim 2, characterized in that, The rectifier unit includes a diode D19, the first energy storage unit includes a capacitor C48, and the first filter unit includes a common-mode rejection inductor T1, a capacitor C36, a capacitor C37, and a filter IC11. The anode of the diode D19 is connected to the power input terminal, the cathode of the diode D19 is connected to one end of the capacitor C48 and the common-mode rejection inductor T1, the other end of the common-mode rejection inductor T1 is connected to the capacitors C36 and C37 respectively, and both the capacitors C36 and C37 are connected to the filter IC11. The second energy storage unit includes capacitors C38, C39, and C40, diodes D20 and D21, and resistor R38. The anode of diode D20, capacitors C38 and C39 are all connected to filter IC11, and the cathode of diode D21 is connected to the cathode of resistor R38, capacitor C40, and diode D21. The DC-DC converter includes chip IC10. The second filter unit includes capacitors C41, C42, C43, C44, C45, C46, ​​and C47. Capacitors C41 and C42 are connected in parallel, C43 and C44 are connected in parallel, and C46 and C47 are connected in parallel to chip IC10. The low dropout three-terminal voltage regulator includes chip IC12, capacitors C49, C50, C51, and C52. Capacitors C49, C50, C51, and C52 are connected in parallel to chip IC12.

4. The rotor speed signal processor with dual-mode criteria according to claim 3, characterized in that, Both the first energy storage unit and the second energy storage unit use high-energy tantalum capacitors. The capacitance values ​​of capacitors C41, C43, and C46 are greater than the capacitance values ​​of capacitors C36, C37, C39, C40, C42, C44, C45, and C47.

5. The rotor speed signal processor with dual-mode criteria according to claim 1, characterized in that, The detection module includes a self-test signal switching circuit connected to the rotor speed magnetic sensor and a filter circuit, an amplifier circuit and a clamping circuit connected in sequence. The filter circuit and the main control module are both connected to the self-test signal switching circuit. The self-test signal switching circuit is used to perform a power-on BIT test on the rotor speed magnetic sensor. The filtering circuit is used to filter the input frequency signal of the self-test signal switching circuit. The amplification circuit is used to amplify the filtered signal and shape the amplified signal into a square wave signal. The clamping circuit is used to process the square wave signal and send it to the main control module.

6. The rotor speed signal processor with dual-mode criteria according to claim 5, characterized in that, The alarm module includes an alarm switch circuit connected to the main control module and an alarm control light box connected to the alarm switch circuit. The alarm switch circuit includes a relay, a diode, and an inductor. The alarm switch circuit is used to receive the output level of the main control module. When the clamping circuit clamps the level of the square wave signal to the input range of the main control module, the main control module performs calculations on the speed acquisition signal corresponding to the input frequency signal to obtain the corresponding speed input signal. The main control module performs judgment processing based on the speed input signal and the mode criterion signal to obtain the output level. The main control module controls the alarm control light box to turn on and off through the alarm switch circuit based on the output level. The mode criterion signal includes fixed-wing mode criterion, helicopter and transition mode criterion.

7. The rotor speed signal processor with dual-mode criteria according to claim 6, characterized in that, The mode judgment signal input module includes an RS422 communication circuit connected to the main control module. The RS422 communication circuit is used to transmit the speed value processed by the main control module to the motor management system and send the mode judgment signal of the motor management system to the main control module.

8. The rotor speed signal processor with dual-mode criteria according to claim 1, characterized in that, The main control module controls the detection module to detect the connection status between the rotor speed magnetic sensor and the rotor speed signal processor, including: The main control module sends a power-on self-test command to the detection module, and the detection module checks whether there is a signal input at the input interface of the rotor speed magnetic sensor; If there is no signal input, the main control module sets the input frequency self-test signal to control the rotor speed magnetic sensor to connect to the speed measurement channel. The main control module receives the speed acquisition signal from the speed measurement channel, performs calculations, and determines whether the speed measurement channel is normal. Each rotor speed magnetic sensor includes one speed measurement channel. If normal, the main control module selects the acquisition frequency corresponding to the rotor speed acquisition signal according to the lowest measurement frequency of the rotor speed magnetic sensor. The acquisition frequency is determined by the frequency signal change rate based on the engine speed change rate and calculated using a threshold comparison algorithm and a speed gradient prediction algorithm.

9. The rotor speed signal processor with dual-mode criteria according to claim 8, characterized in that, Also includes: The detection module is also used to detect the input level of the AD interface of the main control module to determine whether the power supply of the main control module is normal. If normal, the detection module is also used to detect and compare the received and transmitted data of the communication interface of the main control module to determine whether the communication interface of the main control module is normal.

10. The rotor speed signal processor with dual-mode criteria according to claim 1, characterized in that, The rotor speed signal processor also includes a cover plate and a limiting component disposed on the housing. The limiting component includes a flat washer disposed on the side of the housing, a spring washer fitted to the flat washer, and a pan head screw. One end of the pan head screw is connected to the electrical connector, and the other end of the pan head screw is used to fix the spring washer and the flat washer.

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