A signal processing and fault monitoring method for EVTOL flight control electronics

Abstract

The present application belongs to the field of EVTOL flight control, and particularly relates to a signal processing and fault monitoring method for EVTOL flight control electronics. The method comprises the following steps: step 1: receiving pitch axis, roll axis, yaw axis and vertical axis sensor signals from a control system, and obtaining a pitch angle, a roll angle, a yaw angle and a vertical angle through addition, subtraction, multiplication, division and arctangent processing; step 2: self-monitoring sine voltage or cosine voltage output by a magneto-resistance sensor to obtain a transient self-monitoring result; and step 3: sending the pitch angle, the roll angle, the yaw angle, the vertical angle and the transient self-monitoring result between two channels, and judging a CCDL transient fault state after 3 ms, and if no CCDL permanent fault occurs, then performing two-channel voting, and finally sending a channel voting value out through a CAN / CANFD bus.

Description

Technical Field

[0001] This invention belongs to the field of EVTOL flight control, specifically relating to a signal processing and fault monitoring method for EVTOL flight control electronics. Background Technology

[0002] The control system of a certain type of EVTOL consists of a main joystick and an auxiliary control controller. The main joystick comprises a main control device and main control electronics, while the auxiliary control controller comprises an auxiliary control device and auxiliary control electronics. The main joystick or auxiliary control controller controls the flying car's forward and backward movement, left / right lateral movement, altitude gain / loss, and left / right yaw, providing the pilot with a control command interface and simultaneously outputting control commands to the FCU for aircraft control.

[0003] The main control electronics are configured with two channels. Except for the bus interface, the hardware requirements for channels A and B are identical. The following description will use channel A as an example, and channel B can be designed accordingly. The main control electronics acquires analog signals from the longitudinal, lateral, vertical, and yaw displacement sensors and PTT switch signals through the signal interface and processing module. After calculation and processing, the information is uploaded to the FCU via the CANFD / CAN bus.

[0004] The auxiliary control electronics are single-channel configured. They acquire discrete signals from the forward / backward, left / right, and up / down switches on the auxiliary control device via a signal interface and processing module. After processing and calculation, the information is uploaded to the FCU via CANFD. A master control switch is located on the auxiliary control device to cut off the power supply to the master joystick.

[0005] Previous operating systems used a DSP+FPGA architecture, with data acquisition completed on the FPGA and computation and processing completed on the DSP. This resulted in poor real-time performance and a significant waste of device resources. Summary of the Invention

[0006] Purpose of the invention: To propose a signal processing and fault monitoring method for EVTOL flight control electronics, which uses FPGA to process and calculate data from magnetoresistive sensor signals (pitch axis, roll axis, yaw axis) and potentiometer signals (vertical axis) to obtain pitch / roll / yaw / vertical angles, while monitoring and processing abnormal situations, thereby improving the real-time performance and safety of the control system.

[0007] Technical solution:

[0008] A signal processing and fault monitoring method for EVTOL flight control electronics, applied to a two-channel main control electronics system, the method comprising:

[0009] Step 1: Receive pitch axis, roll axis, yaw axis and vertical axis sensor signals from the control system, and obtain pitch angle, roll angle, yaw angle and vertical angle by addition, subtraction, multiplication, division and arctangent processing;

[0010] Step 2: Perform self-monitoring on the sinusoidal or cosine voltage output by the magnetoresistive sensor to obtain transient self-monitoring results;

[0011] Step 3: The two channels send pitch angle, roll angle, yaw angle, vertical angle and transient self-monitoring results to each other. After 3ms, the transient fault status of CCDL is judged. If no permanent CCDL fault occurs, the two channels vote and finally send the channel voting value out through the CAN / CANFD bus.

[0012] Preferably, in step 1, the pitch axis angle θ p The calculation method is as follows:

[0013]

[0014] Where Pitch_Sin is the sine wave of the pitch axis, Pitch_Cos is the cosine wave of the pitch axis, 4V_PS is the 4V power supply signal, and θ p It is the pitch axis angle.

[0015] Preferably, in step 2, the transient self-monitoring result of the pitch axis is: if the pitch axis sinusoidal voltage monitoring result is normal, the pitch axis cosine voltage monitoring result is normal, and the monitoring result of the sum of squares of the pitch axis sinusoidal voltage and cosine voltage is normal, the transient self-monitoring result of the pitch axis is normal; otherwise, the transient self-monitoring result of the pitch axis is abnormal.

[0016] Preferably, in step 2, the pitch axis sinusoidal voltage monitoring result is normal when the sinusoidal voltage Pitch_SIN is between the lower threshold of 7% 4V_PS and the upper threshold of 93% 4V_PS; otherwise, the pitch axis sinusoidal voltage monitoring result is abnormal.

[0017] Preferably, in step 2, the pitch axis cosine voltage monitoring result is normal, specifically: when the cosine voltage Pitch_COS is between the lower threshold of 7% 4V_PS and the upper threshold of 93% 4V_PS, the pitch axis sine voltage monitoring result is normal; otherwise, the pitch axis sine voltage monitoring result is abnormal.

[0018] Preferably, in step 2, the monitoring result of the sum of squares of the pitch axis sine voltage and cosine voltage is normal, specifically:

[0019] The sum of the squares of the sinusoidal voltage and the cosine voltage along the pitch axis: At the lower threshold of 0.011 (4V_PS)2 With an upper threshold of 0.14 (4V_PS) 2 When the pitch axis sinusoidal voltage and cosine voltage square sum monitoring results are normal, otherwise the pitch axis sinusoidal voltage and cosine voltage square sum monitoring results are abnormal.

[0020] Preferably, step 3 specifically includes:

[0021] If a CCDL transient fault occurs and lasts for 5 cycles, it is considered a permanent CCDL fault. The pitch angle and transient self-monitoring result theta_P1_VF of other channels acquired by this channel are set to the fault-safe value of 0°, the transient self-monitoring result is invalid, and the longitudinal manipulation command flag FCSS_PthVD is set to invalid (0). The CANFD / CAN bus sends the fault-safe value of 0° for this channel. If a CCDL transient fault occurs and does not last for 5 cycles, the pitch angle theta_P1 and transient self-monitoring result theta_P1_VF of other channels acquired by this channel are set to the normal value of the previous cycle.

[0022] If no permanent CCDL fault occurs, a vote is taken based on the two channel values. If the difference between the two channel values ​​is less than or equal to 2° and the transient self-monitoring results of both channels are valid, the channel voting value is (theta_P-theta_P1) / 2, and the transient longitudinal manipulation command flag PthVD is set to valid; otherwise, the channel voting value is the fault-safe value of 0°, and the transient longitudinal manipulation command flag PthVD is set to invalid.

[0023] Preferably, step 3 further includes:

[0024] The voting value of the channel is limited. If the voting value of the channel exceeds the upper threshold, the upper threshold value is used; if the voting value of the channel exceeds the lower threshold, the lower threshold value is used.

[0025] Based on the transient longitudinal control command flag PthVD, the CANFD / CAN bus determines the data to be transmitted: If the transient longitudinal control command flag PthVD is invalid and lasts for more than 10 cycles, a permanent fault is considered to have occurred, the longitudinal control command flag FCSS_PthVD is invalid and does not recover, and the CANFD / CAN bus transmits the fault safety value 0° for this channel; if the transient longitudinal control command flag PthVD is invalid and does not last for more than 10 cycles, the CANFD / CAN bus transmits the previous cycle's normal value for the voting value of this channel; if the transient longitudinal control command flag PthVD is valid and the longitudinal control command flag FCSS_PthVD is valid, then the CANFD / CAN bus transmits the channel voting value; if the transient longitudinal control command flag PthVD is valid and the longitudinal control command flag FCSS_PthVD is invalid, then the CANFD / CAN bus transmits the fault safety value 0°.

[0026] Beneficial effects:

[0027] The control system for the EVTOL flight controller adopts a dual-redundant design. Except for the bus interface, the hardware requirements for channels A and B are identical. The following description will use channel A as an example, and channel B can be designed accordingly. The functions of acquiring analog signals from longitudinal, lateral, vertical, and yaw displacement sensors and PTT switch signals through the signal interface and processing module, and uploading the information to the FCU through CANFD / CAN bus after calculation and processing are all implemented using complex electronic hardware and hardware programmable logic devices. This design also uses FPGA as the implementation carrier. By utilizing the parallelism and strong computing power of FPGA, pitch / roll / yaw / vertical angles can be easily calculated and fault monitoring can be completed. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the pitch axis signal processing and fault monitoring process.

[0029] Figure 2 This is a schematic diagram of the self-monitoring algorithm for the pitch axis magnetoresistive sensor. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to the accompanying drawings.

[0031] Example 1:

[0032] Combination Figure 1 As shown in the figure, this embodiment provides a flow chart for pitch axis signal processing and fault monitoring, and the specific implementation steps are as follows. The method is applied to a two-channel configured main control electronic system.

[0033] Step 1: Calculate the pitch axis angles theta_P and theta_P1 for the main channel and auxiliary channel respectively.

[0034] Step 2: Calculate the pitch axis transient self-monitoring results for the main channel and the auxiliary channel respectively: Obtain the pitch axis transient self-monitoring results theta_P_VF and theta_P1_VF through self-monitoring of the pitch axis magnetoresistive sensor.

[0035] Step 3: The two channels exchange pitch angles and transient self-monitoring results via the CCDL bus.

[0036] Step 4: 3ms after this channel sends data via CCDL, it checks the transient fault status of CCDL. If a CCDL transient fault occurs and lasts for 5 cycles, it is considered a permanent CCDL fault. The pitch angle and transient self-monitoring result theta_P1_VF of other channels acquired by this channel are set to the fault-safe value (pitch angle is 0°, transient self-monitoring result is invalid). The longitudinal manipulation command flag FCSS_PthVD is set to invalid (0). The CANFD / CAN bus sends the fault-safe value (0°) of this channel. If a CCDL transient fault occurs but does not last for 5 cycles, the pitch angle theta_P1 and transient self-monitoring result theta_P_VF1 of other channels acquired by this channel are set to the normal value of the previous cycle.

[0037] Step 5: Vote based on the two channel values. If the difference between the two channel values ​​is less than or equal to 2° and the transient self-monitoring results of both channels are valid, then the channel voting value is (theta_P-theta_P1) / 2, and the transient longitudinal manipulation command flag PthVD is set to valid; otherwise, the channel voting value is the fault-safe value (0°), and the transient longitudinal manipulation command flag PthVD is set to invalid.

[0038] Step Six: Limit the channel voting value. If the channel voting value exceeds the upper threshold, use the upper threshold value; if the channel voting value exceeds the lower threshold, use the lower threshold value. See the table below for specific threshold parameters.

[0039]

[0040] Step 7: Based on the transient longitudinal manipulation command flag PthVD, determine the data to be sent by the CANFD / CAN bus. If the transient longitudinal manipulation command flag PthVD is invalid (0) and lasts for more than 10 cycles, a permanent fault is considered to have occurred, the longitudinal manipulation command flag FCSS_PthVD is invalid (0), and this flag is not restored, and the CANFD / CAN bus sends the fault-safe value (0°) for this channel; if the transient longitudinal manipulation command flag PthVD is invalid (0) and does not last for more than 10 cycles, the CANFD / CAN bus sends the normal value of the previous cycle for the voting value of this channel; if the transient longitudinal manipulation command flag PthVD is valid (1) and the longitudinal manipulation command flag FCSS_PthVD is valid (1), then the CANFD / CAN bus sends the channel voting value; if the transient longitudinal manipulation command flag PthVD is valid (1) and the longitudinal manipulation command flag FCSS_PthVD is invalid (0), then the CANFD / CAN bus sends the fault-safe value (0°).

[0041] Example 2:

[0042] In this embodiment, the sine and cosine inputs of the output signals (pitch axis, roll axis, yaw axis) of each magnetoresistive sensor are sampled synchronously. Oversampling filtering is used within the AD converter to output the sampled and converted sensor signals. Data processing and calculations are performed on the magnetoresistive sensor signals (pitch axis, roll axis, yaw axis) to obtain the pitch / roll / yaw angles.

[0043] The specific calculation method for the pitch axis angle is as follows:

[0044]

[0045] Note: The units for Pitch_Sin (sine wave of the pitch axis), Pitch_Cos (cosine wave of the pitch axis), and 4V_PS (4V power signal) are V (volts), θ p The unit for pitch axis angle is ° (degrees).

[0046] The specific implementation uses the CORDIC algorithm based on FPGA. The core of the algorithm is the (pseudo) rotation angle, where tanθ t =2 -t Therefore, the equation is x. i+1 =x i -d i y i 2 -i ,y i+1 =y i +d i x i 2 -i An angle accumulator is used to track the accumulated rotation angle, z, during each iteration. i+i =z i -d i θ i . d i It is a decision operator used to determine the direction of rotation, so each iteration requires two shifts, one lookup table, and three additions. The corresponding arctangent result can be obtained after 16 iterations.

[0047] Example 3

[0048] Combination Figure 2 As shown in this embodiment, a self-monitoring algorithm for the pitch axis magnetoresistive sensor is provided to obtain the transient self-monitoring results of the pitch axis.

[0049] The pitch axis magnetoresistive sensor outputs a sinusoidal voltage (Pitch_SIN) or a cosine voltage.

[0050] The lower threshold for (Pitch_COS) monitoring is 7% of 4V_PS, and the upper threshold is 93% of 4V_PS.

[0051] The square of the pitch-axis sinusoidal voltage plus the square of the cosine voltage. The lower threshold for monitoring is 0.011 (4V_PS). 2 The upper threshold for monitoring is 0.14 (4V_PS). 2 .

[0052] Pitch axis transient self-monitoring results theta_P_VF = Pitch_SIN monitoring & Pitch_COS monitoring & Monitoring.

[0053] If either the sine or cosine voltage output by the pitch axis magnetoresistive sensor exceeds the threshold range, or if the sum of the squares of the sine and cosine voltages exceeds the threshold range, then the magnetoresistive sensor is considered to have experienced a transient fault.

[0054] The signal acquisition, processing, and fault monitoring functions of this invention are performed by the FPGA inside the operating system. Information is uploaded to the FCU via the CANFD / CAN bus.

Claims

1. A signal processing and fault monitoring method for EVTOL flight control electronics, characterized in that, The method, applied to a two-channel configured master control electronic system, includes: Step 1: Receive pitch axis, roll axis, yaw axis and vertical axis sensor signals from the control system, and obtain pitch angle, roll angle, yaw angle and vertical angle by addition, subtraction, multiplication, division and arctangent processing; Step 2: Perform self-monitoring on the sinusoidal or cosine voltage output by the magnetoresistive sensor to obtain transient self-monitoring results; Step 3: The two channels send pitch angle, roll angle, yaw angle, vertical angle and transient self-monitoring results to each other. After 3ms, the transient fault status of CCDL is judged. If no permanent CCDL fault occurs, the two channels vote and finally send the channel voting value out through the CAN / CANFD bus.

2. The signal processing and fault monitoring method for EVTOL flight control electronics according to claim 1, characterized in that, In step 1, the pitch axis angle θ P The calculation method is as follows: Where Pitch_Sin is the sine wave of the pitch axis, Pitch_Cos is the cosine wave of the pitch axis, 4V_PS is the 4V power supply signal, and θ p It is the pitch axis angle.

3. The signal processing and fault monitoring method for EVTOL flight control electronics according to claim 2, characterized in that, In step 2, the transient self-monitoring result of the pitch axis is as follows: if the pitch axis sinusoidal voltage monitoring result is normal, the pitch axis cosine voltage monitoring result is normal, and the monitoring result of the sum of squares of the pitch axis sinusoidal voltage and cosine voltage is normal, the transient self-monitoring result of the pitch axis is normal; otherwise, the transient self-monitoring result of the pitch axis is abnormal.

4. The signal processing and fault monitoring method for EVTOL flight control electronics according to claim 3, characterized in that, In step 2, the pitch axis sinusoidal voltage monitoring result is normal, specifically: when the sinusoidal voltage Pitch_SIN is between the lower threshold of 7% 4V_PS and the upper threshold of 93% 4V_PS, the pitch axis sinusoidal voltage monitoring result is normal; otherwise, the pitch axis sinusoidal voltage monitoring result is abnormal.

5. The signal processing and fault monitoring method for EVTOL flight control electronics according to claim 4, characterized in that, In step 2, the pitch axis cosine voltage monitoring result is normal, specifically: when the cosine voltage Pitch_COS is between the lower threshold of 7% 4V_PS and the upper threshold of 93% 4V_PS, the pitch axis sine voltage monitoring result is normal; otherwise, the pitch axis sine voltage monitoring result is abnormal.

6. The signal processing and fault monitoring method for EVTOL flight control electronics according to claim 5, characterized in that, In step 2, the monitoring results for the sum of squares of the pitch axis sine and cosine voltages are normal, specifically: The sum of the squares of the sinusoidal voltage and the cosine voltage along the pitch axis: At the lower threshold of 0.011 (4V_PS) 2 With an upper threshold of 0.14 (4V_PS) 2 When the pitch axis sinusoidal voltage and cosine voltage square sum monitoring results are normal, otherwise the pitch axis sinusoidal voltage and cosine voltage square sum monitoring results are abnormal.

7. The signal processing and fault monitoring method for EVTOL flight control electronics according to claim 6, characterized in that, Step 3, specifically: If a CCDL transient fault occurs and lasts for 5 cycles, it is considered a permanent CCDL fault. The pitch angle and transient self-monitoring result theta_P1_VF of other channels acquired by this channel are set to the fault-safe value of 0°, the transient self-monitoring result is invalid, and the longitudinal manipulation command flag FCSS_PthVD is set to invalid (0). The CANFD / CAN bus sends the fault-safe value of 0° for this channel. If a CCDL transient fault occurs and does not last for 5 cycles, the pitch angle theta_P1 and transient self-monitoring result theta_P1_VF of other channels acquired by this channel are set to the normal value of the previous cycle. If no permanent CCDL fault occurs, a vote is taken based on the two channel values. If the difference between the two channel values ​​is less than or equal to 2° and the transient self-monitoring results of both channels are valid, the channel voting value is (theta_P-theta_P1) / 2, and the transient longitudinal manipulation command flag PthVD is set to valid; otherwise, the channel voting value is the fault-safe value of 0°, and the transient longitudinal manipulation command flag PthVD is set to invalid.

8. The signal processing and fault monitoring method for EVTOL flight control electronics according to claim 7, characterized in that, Step 3 also includes: The voting value of the channel is limited. If the voting value of the channel exceeds the upper threshold, the upper threshold value is used; if the voting value of the channel exceeds the lower threshold, the lower threshold value is used. Based on the transient longitudinal control command flag PthVD, the CANFD / CAN bus determines the data to be transmitted: If the transient longitudinal control command flag PthVD is invalid and lasts for more than 10 cycles, a permanent fault is considered to have occurred, the longitudinal control command flag FCSS_PthVD is invalid and does not recover, and the CANFD / CAN bus transmits the fault safety value 0° for this channel; if the transient longitudinal control command flag PthVD is invalid and does not last for more than 10 cycles, the CANFD / CAN bus transmits the previous cycle's normal value for the voting value of this channel; if the transient longitudinal control command flag PthVD is valid and the longitudinal control command flag FCSS_PthVD is valid, then the CANFD / CAN bus transmits the channel voting value; if the transient longitudinal control command flag PthVD is valid and the longitudinal control command flag FCSS_PthVD is invalid, then the CANFD / CAN bus transmits the fault safety value 0°.

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