Asymmetric electrical dual-redundancy linear steering engine and control method

Abstract

The invention relates to an asymmetric electrical dual-redundancy linear steering engine and a control method, and belongs to the field of aviation aircraft steering engine control. The transmission mechanism is used for converting rotation output of the motor into linear displacement output; the first position sensor comprises an electromagnetic induction type angle sensing unit and a contact type displacement sensing unit and is used for detecting the angle and linear displacement of a motor rotor; the second position sensor adopts a differential magnetic encoder and is used for detecting the multi-turn absolute angle of the motor; the first control circuit and the second control circuit are respectively in signal connection with the corresponding position sensors, and respectively drive corresponding windings of the double-winding motor through corresponding driving units to form two redundant control channels configured by adopting asymmetric sensors; state information exchange and redundancy switching are realized between the first control circuit and the second control circuit in an isolated communication mode. Redundant hardware is reduced, the overall structure is compact, and the method is suitable for space-limited equipment such as unmanned aircrafts.

Description

Technical Field

[0001] This invention relates to the field of aircraft servo control, and more particularly to an asymmetric electrically redundant linear servo and its control method. Background Technology

[0002] With the widespread application of unmanned aerial vehicles (UAVs) in both military and civilian fields, the requirements for the reliability and safety of servo systems are becoming increasingly stringent. Traditional dual-redundant linear servos typically employ a symmetrical design, meaning that both control channels use the same sensor configuration and control strategy. While this design offers high reliability, it suffers from issues such as large size, high cost, and heavy weight, limiting its application in small UAVs.

[0003] In existing technologies, dual-redundant servos typically require two complete position sensor systems, leading to structural complexity and increased costs. Especially in space-constrained small UAVs, symmetrical dual-redundant designs often struggle to meet size and weight requirements. Summary of the Invention

[0004] Based on the above analysis, this invention aims to disclose an asymmetric electrically redundant linear servo and its control method; through asymmetric sensor and control algorithm configuration, high system reliability and lightweight design are achieved.

[0005] This invention discloses an asymmetric electrically redundant linear servo, comprising:

[0006] A dual-winding motor has two independent windings;

[0007] The transmission mechanism is used to convert the rotational output of the motor into linear displacement output, thereby driving the output shaft of the servo motor to move linearly.

[0008] The first position sensor includes an electromagnetic induction angle sensing unit and a contact displacement sensing unit, used to detect the motor rotor angle and linear displacement.

[0009] The second position sensor, using a differential magnetic encoder, is used to detect the absolute angle of the motor over multiple turns;

[0010] The first control circuit and the second control circuit are respectively connected to the corresponding position sensor signals, and each drives the corresponding winding of the dual-winding motor through the corresponding drive unit, forming two redundant control channels with asymmetric sensor configuration to control the movement of the servo motor.

[0011] The first control circuit and the second control circuit exchange status information and switch redundancy through isolated communication.

[0012] Furthermore, the electromagnetic induction angle sensing unit is a rotary transformer, and the contact displacement sensing unit is a potentiometer; wherein,

[0013] The stator of the resolver is fixed in the inner hole of the rear end cover of the main shell of the steering gear, and the rotor is connected with the tail end extension shaft of the double-winding motor through a key, which is used for detecting the single-circle angle signal of the motor;

[0014] The potentiometer is configured to detect the linear displacement of the output shaft of the steering gear and output the linear displacement signal of the steering gear.

[0015] Further, the first control circuit comprises a resolver decoding circuit, a potentiometer detection circuit, a first three-phase voltage and current detection circuit, a first bus voltage and current detection circuit, a first signal conditioning circuit and a first controller.

[0016] The resolver decoding circuit is connected with the stator winding of the resolver, and after the angle signal detected by the resolver is subjected to analog-to-digital conversion and resolver decoding, the first motor rotor angle is obtained.

[0017] The potentiometer detection circuit is connected with the sliding end of the potentiometer, and after the linear displacement signal of the steering gear detected by the potentiometer is subjected to analog-to-digital conversion and signal conditioning, the first linear displacement of the steering gear is obtained.

[0018] The first three-phase voltage and current detection circuit is connected with the three-phase terminals of the first winding of the double-winding motor, respectively, and is used for sampling phase voltage and phase current.

[0019] The first bus voltage and current detection circuit is connected with the power bus of the first winding of the double-winding motor, and is used for sampling bus voltage and bus current.

[0020] The input end of the first signal conditioning circuit is connected with the output ends of the first three-phase voltage and current detection circuit and the first bus voltage and current detection circuit, and the input detection signal is subjected to filtering, amplification and level shifting, and the conditioned signal meeting the ADC input range of the first controller is output.

[0021] The first controller differentiates the continuously input first motor rotor angle to obtain the first motor rotation speed and based on the first motor rotor angle, rotation speed and linear displacement of the steering gear, as well as the conditioned voltage and current signals, executes position-speed-current three-loop cascade PID+FOC calculation, outputs the first SVPWM duty ratio control quantity, drives the first winding through the first driving circuit, and realizes the closed-loop control of the first channel.

[0022] Further, the differential magnetic encoder comprises:

[0023] The driving gear and the driven gear have a gear ratio i rThe driving gear is fixed to the tail end of the motor extension shaft, and the driven gear is sleeved on the vertical column of the rear cover of the shell through a sliding bearing, the end faces of the two gears are coplanar and perpendicular to the motor axis;

[0024] The first and second permanent magnets are coaxially embedded in the center of the end faces of the driving gear and the driven gear, and are both radially magnetized;

[0025] The first and second magnetic encoding chips are respectively opposite to the centers of the first and second permanent magnets with a set axial air gap, and are welded on the same printed circuit board assembly which is fixed parallel to the inner side of the rear cover of the shell.

[0026] Further, the second control circuit comprises: a first magnetic encoder circuit, a second magnetic encoder circuit, a second three-phase voltage and current detection circuit, a second bus voltage and current detection circuit, a second signal conditioning circuit, and a second controller;

[0027] The first and second magnetic encoder circuits are connected with the first and second magnetic encoding chips respectively, and collect the driving gear magnetic encoding angle θ1 and the driven gear magnetic encoding angle θ2 through SPI or I 2 C interface and send them to the second controller;

[0028] The second three-phase voltage and current detection circuit is connected with the three-phase terminals of the second winding of the double-winding motor, and is used for sampling phase voltage and phase current;

[0029] The second bus voltage and current detection circuit is connected with the second winding power bus of the double-winding motor, and is used for sampling bus voltage and bus current;

[0030] The input end of the second signal conditioning circuit is connected with the output ends of the second three-phase voltage and current detection circuit and the second bus voltage and current detection circuit, and the input detection signals are filtered, amplified and level shifted, and the conditioned signals meeting the ADC input range of the second controller are outputted;

[0031] The second controller calculates the second motor rotor angle, speed and rudder linear displacement based on the driving gear magnetic encoding angle θ1 and the driven gear magnetic encoding angle θ2, combines and conditions the voltage and current signals, executes position-speed-current three-loop cascade PID+FOC calculation, outputs the second SVPWM duty ratio control quantity, drives the second winding through the second drive circuit, and realizes the closed-loop control of the second channel.

[0032] Further, the second controller calculates the second motor rotor angle, speed and rudder linear displacement based on the driving gear magnetic encoding angle θ1 and the driven gear magnetic encoding angle θ2; the calculation process comprises:

[0033] 1) Upon power-up, read the magnetic encoding angle θ1 of the driving gear and the magnetic encoding angle θ2 of the driven gear within the range of 0-2π;

[0034] 2) Calculate the unique, non-repeating double-winding motor based on the magnetic encoding angle θ1 of the driving gear and the magnetic encoding angle θ2 of the driven gear. Multiple angles θ within the circle r ;

[0035] θ r =(θ2-θ1) / (i r -1); 0≤θ r <2π / (i r -1);

[0036] 3) Calculation process Circle the integer index k;

[0037] k = floor(θ1 / θ) r _max), where θ r _max=2π / (i r -1);

[0038] 4) Obtain the rotor angle of the second motor

[0039]

[0040] 5) The rotor angle of the second motor was measured continuously. The second rotor speed is obtained by differentiation.

[0041]

[0042] 6) Based on the multi-turn angle θ r Determined as the linear displacement of the second servo motor And the maximum unambiguous displacement of the ball screw;

[0043]

[0044] i is the gear ratio, and L is the ball screw lead.

[0045] Furthermore, the first processor and the second processor establish a cross-processor isolated communication link through a communication interface for dual-channel status information exchange and redundancy switching; wherein,

[0046] In normal operating mode, the first SVPWM signal of the first channel is PWM 1 The second SVPWM signal of the second channel drives the first winding. 2 The second winding is driven, and the two channels achieve torque balance and hot backup through load sharing.

[0047] When any channel self-check or cross-validation determines a fault, a fault code is sent to the opposite end through the isolation communication link across the processors, and the healthy channel receives the fault code and shuts down the fault side SVPWM at the next control cycle and continues to drive its own winding independently, maintaining the continuous output of the rudder.

[0048] Further, each of the first processor and the second processor is configured with a hierarchical redundancy diagnosis module;

[0049] The hierarchical redundancy diagnosis module comprises:

[0050] A range monitoring unit is configured to monitor the motor rotor angle, the motor speed and the rudder linear displacement parameters of the channel, and directly determine a fault of the channel when any parameter exceeds a preset normal range;

[0051] A first cross-validation unit is configured to compare the rudder linear displacement deviation, the motor rotor angle deviation and the motor speed deviation of the two channels when the parameters of the two channels are within the normal range, and trigger redundancy switching when any deviation exceeds a corresponding threshold value Δd th , Δθ th or Δn th , and use the main channel of the two channels to drive its own winding to maintain the continuous output of the rudder;

[0052] A PWM monitoring unit is configured to monitor the SVPWM signal of the channel, and directly determine a fault of the channel when the SVPWM signal exceeds a preset normal range;

[0053] A second cross-validation unit is configured to compare the SVPWM signal deviation of the two channels when the SVPWM signals of the two channels are within the normal range, and trigger redundancy switching when the deviation exceeds a control quantity error threshold value ΔPWM th , and use the main channel of the two channels to drive its own winding to maintain the continuous output of the rudder.

[0054] Further, a filter circuit is further included;

[0055] The filter circuit comprises a first filter circuit and a second filter circuit arranged symmetrically;

[0056] The input ends of the first filter circuit and the second filter circuit are connected to power supply buses with the same voltage, respectively;

[0057] The output ends of the first filter circuit supply power to the first drive circuit and the first control circuit, respectively;

[0058] The output ends of the second filter circuit supply power to the second drive circuit and the second control circuit, respectively;

[0059] Each filter is composed of two stages of common mode filter stage and differential mode filter stage, and both filters take the rudder housing as the reference ground to eliminate common mode interference and improve electromagnetic compatibility and reliability of dual-redundancy power supply.

[0060] The application further discloses a control method of the asymmetric electrical dual-redundancy linear rudder machine.

[0061] S1, after the system is powered on, the first control circuit and the second control circuit perform self-checking in parallel, and verify sensor signal effectiveness, communication link connectivity and power drive module state;

[0062] S2, after the self-checking is passed, the resolver and the potentiometer signals are collected by the first channel and are decoded, and the double magnetic encoding chip signals are collected by the second channel and are solved based on a differential algorithm to obtain motor rotor angle, speed and linear displacement of the rudder machine;

[0063] S3, the state information of the two channels is exchanged through the isolation communication link across the processors, and layered redundant diagnosis is performed, including parameter range monitoring and double-stage cross verification;

[0064] S4, the two channels are driven in parallel in the normal state, and the healthy channel is turned off to drive the fault channel and independently maintain the rudder output in the abnormal state;

[0065] Steps S2 to S4 are cyclically executed at a fixed period.

[0066] The application can realize one of the following beneficial effects:

[0067] The asymmetric electrical dual-redundancy linear rudder machine and the control method disclosed by the application reduce redundant hardware, reduce volume and cost by adopting an asymmetric sensor design, realize multi-turn absolute angle measurement by a differential magnetic encoder, reduce complex mechanical structure, improve fault tolerance and safety by a double-control-circuit heterogeneous algorithm, improve system reliability by parallel communication and redundant switching mechanism, and are compact in overall structure and suitable for space-limited devices such as unmanned aerial vehicles. BRIEF DESCRIPTION OF DRAWINGS

[0068] The accompanying drawings are only for the purpose of illustrating specific embodiments and are not considered as limiting the application, and in the whole drawings, the same reference signs represent the same parts;

[0069] Figure 1 Fig. 1 is a mechanical structure schematic diagram of the asymmetric electrical dual-redundancy linear rudder machine in the embodiments of the application;

[0070] Figure 2 Fig. 2 is a system structure schematic diagram of the asymmetric electrical dual-redundancy linear rudder machine in the embodiments of the application;

[0071] Figure 3The schematic diagram of the differential magnetic encoder principle in the embodiment of the present application

[0072] Figure 4 The schematic diagram of the control circuit structure in the embodiment of the present application

[0073] Figure 5 The schematic diagram of the driving circuit structure in the embodiment of the present application

[0074] Figure 6 The schematic diagram of the filter circuit structure in the embodiment of the present application

[0075] Figure 7 The control method flow chart of the asymmetric electrical dual-redundancy linear actuator in the embodiment of the present application

[0076] Figure 8 The more detailed control method flow chart in the embodiment of the present application. DETAILED DESCRIPTION

[0077] The preferred embodiments of the present application will be specifically described below in conjunction with the accompanying drawings, wherein the drawings form a part of the present application and are used to explain the principles of the embodiments of the present application.

[0078] One embodiment of the present application discloses an asymmetric electrical dual-redundancy linear actuator, comprising:

[0079] The double-winding motor has two groups of independent windings;

[0080] The transmission mechanism is used for converting the rotary output of the motor into linear displacement output and pushing the linear movement of the output shaft of the actuator;

[0081] The first position sensor comprises an electromagnetic induction type angle sensing unit and a contact type displacement sensing unit and is used for detecting the angle of the motor rotor and the linear displacement;

[0082] The second position sensor adopts a differential magnetic encoder and is used for detecting the multi-turn absolute angle of the motor;

[0083] The first control circuit and the second control circuit are respectively connected with the corresponding position sensor signals and respectively drive the corresponding windings of the double-winding motor through the corresponding driving units, thereby constituting two redundant control channels adopting asymmetric sensor configuration to control the movement of the actuator;

[0084] The first control circuit and the second control circuit realize the exchange of state information and the redundant switching through the way of isolated communication.

[0085] As shown in Figure 1 and 2 , the mechanical structure schematic diagram and the system structure schematic diagram of the asymmetric electrical dual-redundancy linear actuator in the embodiment are respectively given.

[0086] In the figure, the gear set and the ball screw constitute the transmission mechanism. The input end of the gear set is connected to the output shaft of the dual-winding motor, and the output end drives the ball screw to rotate. The nut of the ball screw is fixed to the output shaft of the servo motor.

[0087] The rotational motion output by the motor is reduced in speed and increased in torque by the gear reducer, which drives the ball screw to rotate. The ball screw nut converts the rotational motion into linear displacement, which is then output to realize the control torque of the servo motor through the servo motor output shaft.

[0088] The rotary transformer and potentiometer constitute the first position sensor; the second position sensor is a differential magnetic encoder; the figure shows the relative positions of the sensor housing, lead screw, and dual-winding motor.

[0089] Specifically, the first position sensor includes a rotary transformer and a potentiometer; wherein,

[0090] The stator of the rotary transformer is fixed to the inner hole of the rear end cover of the servo motor main housing, and the rotor is keyed to the tail extension shaft of the dual-winding motor to detect the single-turn angle signal of the motor.

[0091] The potentiometer is configured to detect the linear displacement of the servo motor output shaft and output a servo motor linear displacement signal.

[0092] Preferably, the potentiometer body is fixed to the servo housing, and its sliding end is connected to the side of the servo output shaft through a connector to convert the linear displacement of the servo output shaft into a voltage signal.

[0093] Specifically, such as Figure 3 As shown, the second position sensor includes:

[0094] The ratio of the number of teeth between the driving gear and the driven gear is i. r The driving gear is fixed to the end of the motor extension shaft, and the driven gear is loosely fitted to the rear cover column of the housing through a sliding bearing. The end faces of the two gears are coplanar and perpendicular to the motor axis.

[0095] The first permanent magnet and the second permanent magnet are coaxially embedded at the center of the end faces of the driving gear and the driven gear, respectively, and both are radially magnetized;

[0096] The first magnetic encoding chip and the second magnetic encoding chip are respectively positioned so that the axial air gap is directly opposite the center of the first permanent magnet and the second permanent magnet, and are soldered onto the same printed circuit board assembly (PCBA), which is fixed parallel to the inside of the back cover of the housing.

[0097] The set axial air gap is 0.3 to 0.8 mm.

[0098] Specifically, such as Figure 4The first control circuit comprises a resolver decoding circuit, a potentiometer detection circuit, a first three-phase voltage and current detection circuit, a first bus voltage and current detection circuit, a first signal conditioning circuit, and a first controller.

[0099] The resolver decoding circuit is connected with the resolver stator winding, and the resolver decoding circuit obtains the first motor rotor angle after analog-to-digital conversion and resolver decoding of the angle signal detected by the resolver.

[0100] The potentiometer detection circuit is connected with the sliding end of the potentiometer, and the potentiometer detection circuit obtains the first linear displacement of the steering engine after analog-to-digital conversion and signal conditioning of the linear displacement signal of the steering engine detected by the potentiometer.

[0101] The first three-phase voltage and current detection circuit is connected with the three-phase terminals of the first winding of the double-winding motor, and is used for sampling phase voltage and phase current.

[0102] The first bus voltage and current detection circuit is connected with the power bus of the first winding of the double-winding motor, and is used for sampling bus voltage and bus current.

[0103] The input end of the first signal conditioning circuit is connected with the output ends of the first three-phase voltage and current detection circuit and the first bus voltage and current detection circuit, the first signal conditioning circuit filters, amplifies and level shifts the input detection signal, and outputs the conditioned signal meeting the ADC input range of the first controller.

[0104] The first controller obtains the first motor rotor angle The first motor rotor speed is obtained by differentiation. The first SVPWM duty ratio control quantity is outputted by the first control circuit based on the first motor rotor angle, the first motor rotor speed, the linear displacement of the steering engine, and the conditioned voltage and current signals, the first winding is driven by the first driving circuit, and the closed-loop control of the first channel is realized.

[0105] The second control circuit comprises a first magnetic encoder circuit, a second magnetic encoder circuit, a second three-phase voltage and current detection circuit, a second bus voltage and current detection circuit, a second signal conditioning circuit, and a second controller.

[0106] The first and second magnetic encoder circuits are connected with the first and second magnetic encoder chips respectively, and the driving gear magnetic encoding angle θ1 and the driven gear magnetic encoding angle θ2 are collected through SPI or I 2 C interface and are sent into the second controller.

[0107] The second three-phase voltage and current detection circuit is connected with the three-phase terminals of the second winding of the double-winding motor, and is used for sampling phase voltage and phase current.

[0108] The second bus voltage and current detection circuit is connected to the second winding power supply bus of the dual-winding motor and is used to sample the bus voltage and bus current.

[0109] The input terminal of the second signal conditioning circuit is connected to the output terminals of the second three-phase voltage and current detection circuit and the two bus voltage and current detection circuit. It filters, amplifies and levels-shifts the input detection signal and outputs a conditioned signal that meets the input range of the second controller's ADC.

[0110] The second controller calculates the rotor angle, speed, and servo linear displacement of the second motor based on the magnetic encoding angle θ1 of the driving gear and the magnetic encoding angle θ2 of the driven gear. It combines and conditions the voltage and current signals, performs position-speed-current three-loop cascade PID+FOC calculation, and outputs the second SVPWM duty cycle control quantity. This quantity drives the second winding through the second drive circuit, realizing closed-loop control of the second channel.

[0111] Preferably, the second controller calculates the rotor angle, speed, and servo motor linear displacement of the second motor based on the magnetic encoding angle θ1 of the driving gear and the magnetic encoding angle θ2 of the driven gear; the calculation process includes:

[0112] 1) Upon power-up, read the magnetic encoding angle θ1 of the driving gear and the magnetic encoding angle θ2 of the driven gear within the range of 0-2π;

[0113] 2) Calculate the unique, non-repeating double-winding motor based on the magnetic encoding angle θ1 of the driving gear and the magnetic encoding angle θ2 of the driven gear. Multiple angles θ within the circle r ;

[0114] θ r =(θ2-θ1) / (i r -1); 0≤θ r <2π / (i r -1);

[0115] 3) Calculation process Circle the integer index k;

[0116] k = floor(θ1 / θ) r _max), where θ r _max=2π / (i r -1);

[0117] 4) Obtain the rotor angle of the second motor

[0118]

[0119] 5) The rotor angle of the second motor was measured continuously. Differentiating to obtain the second rotor speed

[0120]

[0121] 6) According to the multi-turn angle θ r Determine the second steering engine linear displacement And the maximum unambiguous displacement of the ball screw;

[0122]

[0123] i is the gear ratio, and L is the ball screw lead.

[0124] As shown in Figure 4 The first processor and the second processor establish a cross-processor isolated communication link through a communication interface, which is used for double-channel state information exchange and redundant switching;

[0125] In normal operation mode, the first SVPWM signal PWM 1 of the first channel drives the first winding, and the second SVPWM signal PWM 2 of the second channel drives the second winding, and the two channels realize torque balance and hot backup through load sharing;

[0126] When any channel self-checking or cross-validation determines a fault, the fault code is sent to the opposite end through the cross-processor isolated communication link, and after the healthy channel receives it, the SVPWM of the fault side is turned off in the next control period, and the winding of the healthy channel is independently continued to be driven, so that the continuous output of the steering engine is maintained.

[0127] The first processor and the second processor are each configured with a layered redundant diagnosis module;

[0128] The layered redundant diagnosis module comprises:

[0129] A range monitoring unit is configured to monitor the motor rotor angle, speed and steering engine linear displacement parameters of the channel, and directly determine the fault of the channel when any parameter exceeds the preset normal range;

[0130] A first cross-validation unit is configured to compare the steering engine linear displacement deviation, motor rotor angle deviation and motor speed deviation of the two channels when the parameters of the two channels are within the normal range, and trigger redundant switching when any deviation exceeds the corresponding threshold value Δd th , Δθ th or Δn th The main channel of the two channels outputs the motor rotor angle, speed and steering engine linear displacement parameters to continue to calculate the control quantity, and the auxiliary channel no longer calculates the control quantity.

[0131] The steering engine linear displacement deviation is

[0132] Motor rotor angle deviation is

[0133] Motor speed deviation is

[0134] Δd th , Δθ th , Δn th are respectively rudder linear displacement error threshold, motor rotor angle error threshold, motor speed error threshold;

[0135] The PWM monitoring unit is used for monitoring the SVPWM signal of the channel, and directly determines that the channel is faulty when the SVPWM signal exceeds the preset normal range.

[0136] The second cross-validation unit is used for comparing the SVPWM signal deviation of the two channels when the SVPWM signals of the two channels are in the normal range, triggering the redundancy switching when the deviation exceeds the control quantity error threshold ΔPWM th , and using the main channel in the two channels to output the control quantity to drive its own winding, maintaining the continuous output of the rudder, and the auxiliary channel no longer outputs the control quantity.

[0137] The SVPWM signal deviation is |PWM 1 -PWM 2 |;

[0138] ΔPWM th is the control quantity error threshold.

[0139] Preferably, the first processor and the second processor are each connected with an external CAN bus through a CAN communication circuit.

[0140] The two-way CAN bus (the first CAN and the second CAN) adopts a parallel hot backup working mode; under normal working conditions, the first processor as the main channel receives the flight control instruction through the first CAN, and the backup channel second processor synchronously listens to the instruction frame through the second CAN; when the first CAN bus does not receive a valid frame for 50 ms, the backup channel second processor automatically switches to the instruction receiving mode and reports the bus degradation state. The two-way CAN node ID adopts asymmetric distribution (such as channel 1 is 0x1A0 and channel 2 is 0x1B0), avoiding arbitration failure caused by ID conflict.

[0141] The first controller and the second controller can adopt programmable control devices such as MCU, DSP or FPGA.

[0142] Specifically, as Figure 5As shown, the first driving circuit is connected to the first winding, and a phase voltage and current sampling unit inside the first driving circuit acquires motor operating state signals, generates a driving waveform through an SVPWM modulator, performs level conversion and isolation through a pre-driving circuit, and finally drives a MOS three-phase full-bridge circuit to output three-phase alternating current to the first winding.

[0143] The second driving circuit is connected to the second winding, and a phase voltage and current sampling unit inside the second driving circuit acquires motor operating state signals, generates a driving waveform through an SVPWM modulator, performs level conversion and isolation through a pre-driving circuit, and finally drives a MOS three-phase full-bridge circuit to output three-phase alternating current to the second winding.

[0144] The two driving circuits are electrically isolated and independently powered, and drive two groups of three-phase windings of the double-winding motor, to realize torque balancing and hot backup functions.

[0145] In the preferred scheme, a filter circuit is further included.

[0146] The filter circuit includes symmetrically arranged first and second filter circuits.

[0147] The input ends of the first and second filter circuits are connected to power supply bus lines with the same voltage.

[0148] The output ends of the first filter circuit supply power to the first driving circuit and the first control circuit.

[0149] The output ends of the second filter circuit supply power to the second driving circuit and the second control circuit.

[0150] Each filter is composed of a common-mode filtering stage and a differential-mode filtering stage, and both filters take the rudder housing as a reference ground to eliminate common-mode interference and improve electromagnetic compatibility and reliability of the dual-redundancy power supply.

[0151] As shown in Figure 6 The common-mode filtering stage includes a common-mode choke L0 and a capacitor network composed of capacitors C1, C2 and C3.

[0152] The capacitor C1 is connected between the positive power supply bus and the rudder housing, the capacitor C2 is connected between the negative power supply bus and the rudder housing, and the capacitor C3 is connected across the positive and negative power supply buses. The common-mode choke L0 is connected in series in the power supply bus.

[0153] The differential-mode filtering stage includes a differential-mode choke L1 connected in series in the power supply bus after the common-mode filtering stage.

[0154] The embodiment also discloses a control method of the asymmetric electrical dual-redundancy linear rudder machine, which controls the asymmetric electrical dual-redundancy linear rudder machine as described above, as follows:Figure 7 As shown, comprising the following steps:

[0155] S1, after the system is powered on, the first control circuit and the second control circuit perform self-checking in parallel, verifying sensor signal effectiveness, communication link connectivity and power drive module state;

[0156] S2, after the self-checking passes, the first channel collects resolver and potentiometer signals and decodes, and the second channel collects double magnetic encoder chip signals and calculates motor rotor angle, speed and rudder linear displacement based on a differential algorithm;

[0157] S3, exchange two-channel state information through a cross-processor isolated communication link, perform layered redundant diagnosis, including parameter range monitoring and double-level cross verification;

[0158] S4, normally two channels are driven in parallel, and when an abnormality occurs, the healthy channel is turned off and the fault channel is driven and independently maintains the rudder output;

[0159] Steps S2 to S4 are executed in a fixed cycle.

[0160] More specifically, the control flow is as shown in Figure 8

[0161] • The system is powered on and the dual control circuits are reset simultaneously, entering an independent self-checking program;

[0162] The self-checking program includes hardware state detection and sensor effectiveness verification; if either channel fails the self-checking, immediately report the fault code to the CAN bus and trigger a shutdown lock; if both channels pass, enter the main loop.

[0163] • Two channels collect data parameters in parallel for calculation;

[0164] Among them, in the first channel, the analog signal of the resolver, the voltage signal of the potentiometer, the bus current voltage and the phase current voltage signal are collected synchronously; parameter calculation is performed to obtain the motor rotor angle, speed and rudder linear displacement;

[0165] In the first channel, the angle signals of the first and second magnetic encoders are collected, and the bus current voltage and phase current voltage signals are synchronously sampled; parameter calculation is performed to obtain the motor rotor angle, speed and rudder linear displacement;

[0166] The specific collection and calculation process can refer to the content of the device embodiment;

[0167] • First-level verification and fault diagnosis;

[0168] Including:

[0169] ​(1) Each channel monitors the motor rotor angle, rotation speed and rudder linear displacement parameters of the channel, and directly determines the fault of the channel when any parameter exceeds the preset normal range;

[0170] (2) When the parameters of the two channels are in the normal range, the rudder linear displacement deviation, motor rotor angle deviation and motor rotation speed deviation of the two channels are compared, and when any deviation exceeds the corresponding threshold value Δd th , Δθ th or Δn th , the redundant switching is triggered, the main channel in the two channels outputs the motor rotor angle, rotation speed and rudder linear displacement parameters to continue to calculate the control quantity, and the auxiliary channel no longer calculates the control quantity;

[0171] Control quantity calculation;

[0172] The normally operating channel executes position-speed-current three-loop cascade PID+FOC calculation according to the input motor rotor angle, rotation speed and rudder linear displacement, combined and conditioned voltage and current signals, and outputs the respective channel SVPWM duty ratio control quantity;

[0173] Second level verification and fault diagnosis;

[0174] Including:

[0175] (1) Monitor the SVPWM signal of the channel, and directly determine the fault of the channel when the SVPWM signal exceeds the preset normal range;

[0176] (2) When the SVPWM signals of the two channels are in the normal range, the SVPWM signal deviation of the two channels is compared, and when the deviation exceeds the control quantity error threshold value ΔPWM th , the redundant switching is triggered, the control quantity of the main channel in the two channels is output to drive its own winding, the continuous output of the rudder is maintained, and the auxiliary channel no longer outputs the control quantity;

[0177] The steps after self-checking are executed in a fixed cycle to realize the whole process control of the asymmetric electrical dual redundancy linear rudder.

[0178] In summary, the asymmetric electrical dual redundancy linear rudder and the control method of the embodiment of the application adopt asymmetric sensor design to reduce redundant hardware, reduce volume and cost; the differential magnetic encoder realizes multi-turn absolute angle measurement, reduces complex mechanical structure; the dual control circuit heterogeneous algorithm improves fault tolerance and safety; parallel communication and redundant switching mechanism improves system reliability; the overall structure is compact, and is suitable for unmanned aerial vehicles and other space-limited devices.

[0179] The above merely describes preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. An asymmetric electrical dual-redundancy linear actuator, characterized in that, The asymmetric electric dual-redundancy linear servo mechanism comprises: a double-winding motor having two independent windings; a transmission mechanism for converting the rotary output of the motor into linear displacement output to push the output shaft of the servo mechanism to move linearly; a first position sensor comprising an electromagnetic induction type angle sensing unit and a contact type displacement sensing unit for detecting the angle of the motor rotor and linear displacement; a second position sensor adopting a differential magnetic encoder for detecting the absolute angle of the motor; a first control circuit and a second control circuit connected with the corresponding position sensor signals respectively, and each driving the corresponding winding of the double-winding motor through the corresponding driving unit, thereby forming two redundant control channels adopting asymmetric sensor configuration to control the movement of the servo mechanism; the first control circuit and the second control circuit exchange state information and realize redundant switching through isolated communication.

2. The asymmetric electric dual-redundancy linear servo mechanism according to claim 1, wherein the electromagnetic induction type angle sensing unit is a rotary transformer, and the contact type displacement sensing unit is a potentiometer; wherein the stator of the rotary transformer is fixed in the inner hole of the rear end cover of the servo mechanism main shell, and the rotor is connected with the tail end extension shaft of the double-winding motor through a key, for detecting the single-turn angle signal of the motor; the potentiometer is configured to detect the linear displacement of the output shaft of the servo mechanism, and output the linear displacement signal of the servo mechanism.

3. The asymmetric electric dual-redundancy linear servo mechanism according to claim 2, wherein the first control circuit comprises a rotary transformer decoding circuit, a potentiometer detection circuit, a first three-phase voltage and current detection circuit, a first bus voltage and current detection circuit, a first signal conditioning circuit, and a first controller; the first three-phase voltage and current detection circuit is connected with the three-phase terminals of the first winding of the double-winding motor respectively, for sampling phase voltage and phase current; the first bus voltage and current detection circuit is connected with the power supply bus of the first winding of the double-winding motor, for sampling bus voltage and bus current; the input end of the first signal conditioning circuit is connected with the output ends of the first three-phase voltage and current detection circuit and the first bus voltage and current detection circuit, for filtering, amplifying and level shifting the input detection signals, and outputting the conditioned signals meeting the ADC input range of the first controller.

4. The asymmetric electric dual-redundancy linear servo mechanism according to claim 1, wherein the differential magnetic encoder comprises: a first permanent magnet and a second permanent magnet coaxially embedded in the center of the end face of the driving gear and the driven gear respectively, and both are radially magnetized; a first magnetic encoding chip and a second magnetic encoding chip facing the center of the first permanent magnet and the second permanent magnet respectively with a set axial air gap, and welded on the same printed circuit board assembly, which is fixed parallel to the inner side of the shell rear cover.

5. The asymmetric electric dual-redundancy linear servo mechanism according to claim 4, wherein the second control circuit comprises a first magnetic encoder circuit, a second magnetic encoder circuit, a second three-phase voltage and current detection circuit, a second bus voltage and current detection circuit, a second signal conditioning circuit, and a second controller; wherein The resolver decoding circuit is connected with the resolver stator winding, and after analog-to-digital conversion and resolver decoding are performed on the angle signal detected by the resolver, a first motor rotor angle is obtained The potential meter detection circuit is connected with the sliding end of the potential meter, and the linear displacement signal of the steering engine detected by the potential meter is converted into digital signal and signal processed to obtain the first linear displacement signal of the steering engine ​ ​ ​ The first controller is used to continuously input the first motor rotor angle The first motor speed is obtained by differentiation Based on the first motor rotor angle, speed and linear displacement of the steering gear, and the regulated voltage and current signals, a position-speed-current three-loop cascade PID+FOC solution is executed to output the first SVPWM duty ratio control quantity, which drives the first winding through the first drive circuit to realize closed-loop control of the first channel. ​ ​ The driving gear and the driven gear have a gear ratio i r The driving gear is fixed to the tail end of the motor extension shaft, and the driven gear is sleeved on the rear cover post of the shell through a sliding bearing. The end faces of the two gears are coplanar and perpendicular to the motor axis. ​ ​ ​ ​ The first and second magnetic encoder circuits are connected with the first and second magnetic encoding chips respectively through SPI or I 2 The active gear magnetic encoding angle θ1 and the driven gear magnetic encoding angle θ2 collected by the C interface are sent into the second controller. A second three-phase voltage and current detection circuit is connected with the three-phase terminals of the second winding of the double-winding motor, and is configured to sample phase voltage and phase current. A second bus voltage and current detection circuit is connected with the power bus of the second winding of the double-winding motor, and is configured to sample bus voltage and bus current. An input end of a second signal conditioning circuit is connected with the output ends of the second three-phase voltage and current detection circuit and the second bus voltage and current detection circuit, and is configured to filter, amplify and level shift the input detection signals, and output conditioned signals that meet the input range of the second controller. The second controller is configured to calculate the second motor rotor angle, speed and rudder linear displacement based on the driving gear magnetic encoding angle θ1 and the driven gear magnetic encoding angle θ2, combine and condition the voltage and current signals, perform position-speed-current three-loop cascade PID + FOC calculation, and output second SVPWM duty ratio control quantity to drive the second winding through the second driving circuit, so as to realize closed-loop control of the second channel.

6. The asymmetrical electrical dual-redundancy linear actuator according to claim 5, characterized in that, The second controller calculates the second motor rotor angle, speed and rudder linear displacement based on the driving gear magnetic encoding angle θ1 and the driven gear magnetic encoding angle θ2. The calculation process includes: 1) reading the driving gear magnetic encoding angle θ1 and the driven gear magnetic encoding angle θ2 in the range of 0-2π upon power-on; 2) Calculate the multi-turn angle θ of the unique non-repeating double-winding motor in the circle according to the drive gear magnetic encoding angle θ1, the driven gear magnetic encoding angle θ2 r ;​ θ r = (θ2- θ1) / (i r -1); 0≤θ r <2π / (i r -1); 3) elapsed time integer number of turns k; k = floor(θ1 / θ r _max), where θ r _max = 2π / (i r -1); 4) Get second motor rotor angle 5) second motor rotor angle from continuous measurement Differentiate to get second rotor speed 6) according to the number of turns θ r determined as a straight line displacement of the second steering wheel and the maximum unambiguous displacement of the ball screw; satisfy i is the gear set transmission ratio, and L is the lead of the ball screw.

7. The asymmetric electrical double-redundancy linear rudder machine according to claim 5, wherein The first processor and the second processor are connected through a communication interface to establish a cross-processor isolated communication link, which is used for double-channel state information exchange and redundant switching. In a normal working mode, the first SVPWM signal PWM 1 drives the first winding, the second SVPWM signal PWM 2 drives the second winding, and the two channels realize torque balance and hot backup through load sharing. When any channel is determined to be faulty through self-checking or cross-verification, a fault code is sent to the opposite end through the cross-processor isolated communication link, and the healthy channel turns off the SVPWM of the faulty side in the next control cycle and continues to drive its own winding independently, thereby maintaining continuous output of the rudder machine.

8. The asymmetric electrical double-redundancy linear rudder machine according to claim 7, wherein Each of the first processor and the second processor is configured with a hierarchical redundant diagnosis module. The hierarchical redundant diagnosis module includes: a range monitoring unit configured to monitor the motor rotor angle, speed and rudder linear displacement parameters of the channel, and directly determine the channel to be faulty when any parameter exceeds the preset normal range; The first cross-validation unit is used for comparing the rudder straight displacement deviation, motor rotor angle deviation and motor rotating speed deviation of the two channels when the two-channel parameters are in the normal range. When any deviation exceeds the corresponding threshold value Δd th , Δθ th or Δn th , the redundancy switching is triggered, the main channel in the two channels is used to drive its own winding, and the continuous output of the rudder is maintained. a PWM monitoring unit configured to monitor the SVPWM signal of the channel, and directly determine the channel to be faulty when the SVPWM signal exceeds the preset normal range. The second level cross validation unit is used to compare the deviation of the two channel SVPWM signals when both of them are in the normal range, and trigger the redundancy switching when the deviation exceeds the control quantity error threshold ΔPWM th , and maintain the continuous output of the steering gear by using the main channel in the two channels to drive its own winding.

9. The asymmetric electrical double-redundancy linear rudder machine according to any one of claims 1-8, wherein The filter circuit includes a first filter circuit and a second filter circuit arranged symmetrically. The input ends of the first filter circuit and the second filter circuit are connected to power buses with the same voltage. The output end of the first filter circuit supplies power to the first driving circuit and the first control circuit. The output end of the second filter circuit supplies power to the second driving circuit and the second control circuit. ​ Each filter is composed of common mode filter stage and differential mode filter stage, and the two filters take the rudder housing as the reference ground to eliminate common mode interference and improve the electromagnetic compatibility and reliability of the dual-redundancy power supply.

10. A control method of an asymmetric electrically dual-redundant linear actuator, for controlling the asymmetric electrically dual-redundant linear actuator according to any one of claims 1 to 9, characterized in that, The method comprises the following steps: S1, after the system is powered on, the first control circuit and the second control circuit perform self-checking in parallel to verify the sensor signal effectiveness, the communication link connectivity and the power driving module state; S2, after the self-checking passes, the resolver and the potentiometer signals are collected by the first channel and decoded, and the double magnetic encoding chip signals are collected by the second channel and the motor rotor angle, speed and rudder linear displacement are calculated based on the differential algorithm; S3, the two-channel state information is exchanged through the cross-processor isolation communication link to perform layered redundant diagnosis, including parameter range monitoring and two-stage cross verification; S4, in normal times, the two channels are driven in parallel, and in abnormal times, the healthy channel is turned off to drive the fault channel and independently maintain the rudder output; Steps S2 to S4 are executed in a fixed cycle.

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