Redundancy management method of dual-redundancy electro-hydrostatic servo mechanism
By combining three-loop control and electromagnetic isolation valve, the problem of inconsistent parameters in fault diagnosis of dual redundant electrostatic servo mechanism is solved, realizing fast and accurate fault diagnosis and isolation, and meeting the requirements of lightweight and real-time performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-07
- Publication Date
- 2026-03-10
AI Technical Summary
When a fault occurs, the dual-redundant electrostatic servo mechanism cannot effectively distinguish the inconsistency of parameters between the two channels, resulting in the inability to diagnose the faulty channel. Existing technical methods are complex, have poor real-time performance, and have high hardware requirements.
A three-loop control method is adopted, which compares the speed signal of the servo motor pump with the speed loop input signal, uses an electromagnetic isolation valve to isolate the fault channel, and reconstructs the system by adjusting the position loop gain parameter to achieve fault diagnosis and isolation.
It enables rapid and accurate fault diagnosis and isolation, meets the lightweight requirements of aerospace servos, reduces hardware complexity and fault diagnosis time, and ensures that system performance is not degraded.
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Figure CN121643532A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a redundancy management method for a dual-redundant electrostatic servo mechanism, belonging to the field of electrostatic servo control technology. Background Technology
[0002] In the aerospace field, electrostatic servo mechanisms (EHAs) are critical actuators, and their reliability directly impacts the success or failure of weapon system missions. To meet the stringent "zero-failure" requirements of aerospace missions, redundancy design is the mainstream approach. Among these, triple-redundant systems, with their inherent "two out of three" voting condition, are maturely applied in fault diagnosis and fault-tolerant control. As aerospace missions impose extremely stringent constraints on system weight and size, dual-redundant servo mechanisms offer significant advantages in terms of size, weight, and cost compared to triple-redundant or multi-redundant systems. Dual-redundant electrostatic servo mechanisms, with their more compact structure and lower resource consumption, are gradually becoming the preferred solution for lightweight aerospace servos. However, dual-redundant systems have an inherent bottleneck in fault diagnosis. When a fault occurs, the two redundant channels cannot directly employ the "two out of three" voting method—when the parameters of the two channels are inconsistent, it is impossible to distinguish which channel is faulty, leading to diagnostic difficulties.
[0003] In the prior art, a fault diagnosis and reconfiguration control method for a dual-redundant electrostatic servo mechanism involves constructing a mathematical model of the dual-redundant electrostatic servo mechanism. The main control chip (DSP) generates corresponding virtual current signals based on the mathematical model. Threshold judgments and fault diagnoses are then performed on the two collected motor current signals and one virtual current signal. The two motor current signals are acquired through a current sampling circuit and current balancing control is applied. However, this invention has the following main problems:
[0004] This method requires a high degree of accuracy in constructing the mathematical model of the electrostatic servo mechanism. To improve the accuracy of the virtual redundancy model, it is necessary to calibrate the mathematical model by combining experience and experimental data. This method ensures the accuracy and reliability of fault diagnosis results by addressing the errors in the amplitude and phase of the frequency response. However, the model calibration iteration time is relatively long and there is a certain degree of randomness. Furthermore, considering that the performance of each motor-pump may vary, and that the efficiency of the motor-pump may decrease slightly during long-term operation, this method also has certain limitations.
[0005] This method also places high demands on the acquisition accuracy of the current sensor and the processing method. This method considers the dynamic and static asynchrony of current in a dual-redundant servo mechanism, introducing current balancing feedback control in the inner loop to average the current regions of the two channels, thereby reducing the difference in current between the channels and compensating for the asynchrony between steady-state and dynamic currents.
[0006] Furthermore, a method and system for fault detection and isolation of a dual-redundant servo mechanism is proposed. This invention constructs a controller and sensor system combining dual redundancy and triple redundancy, consisting of a triple-redundant position sensor system, a triple-redundant system controller, and a dual-redundant motor controller. Fault location is then performed on the feedback component or the forward channel component. The system has no single point of failure and no decision-making center, preventing system collapse due to a failure of the decision-making center. However, this invention mainly has the following problems:
[0007] This invention introduces three system controllers and three sensors for fault diagnosis, resulting in a complex system with significant disadvantages in terms of weight, size, and cost. The invention instead places three position sensors at the system output shaft to measure the system's output angle or linear displacement. The three system position outputs obtained from the three sensors are compared with the received control commands, and a "two-out-of-three" vote is used to determine system faults.
[0008] The fault diagnosis method of this invention is also quite complex. After locating the forward channel using a position sensor, it must be switched to a cold backup operating state (one motor works, and the other follows). This further increases the fault determination time by at least three times, and real-time performance cannot be guaranteed. The fault reconstruction scheme of this invention is not applicable to electrostatic servo mechanisms. Fault channel isolation is achieved by shutting down the driver output or disconnecting the power supply to that channel using a switch. Since the flow from both channels of the dual-redundant electrostatic servo mechanism works together in the piston chamber, when the driver output of the abnormal channel is shut down or the power supply is disconnected, the flow generated by the servo motor pump in the normal channel will be consumed by the abnormal motor pump and cannot act normally on the piston rod. Summary of the Invention
[0009] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose a redundancy management method for a dual-redundant electrostatic servo mechanism, which solves the problem that when the parameters of the two channels of a dual-redundant system are inconsistent, it is impossible to distinguish the faulty channel, resulting in the inability to diagnose the problem.
[0010] The technical solution of the present invention is as follows: The method of the present invention relates to a dual redundant electrostatic servo mechanism, including a control module, a first drive module, a second drive module, a first current sensor, a second current sensor, a first servo motor pump, a second servo motor pump, a first rotary transformer, a second rotary transformer, a first electromagnetic isolation valve, a second electromagnetic isolation valve, a piston rod, and a displacement sensor.
[0011] The first drive module, the first servo motor pump, the first current sensor, and the first rotary transformer constitute the first channel; the second drive module, the second servo motor pump, the second current sensor, and the second rotary transformer constitute the second channel.
[0012] The control module performs three-loop control of position, speed, and current through a control correction network, outputs drive signals to the first drive module and the second drive module, and controls the opening and closing of the first and second electromagnetic isolation valves; at the same time, the control module calculates the position deviation based on the received position feedback signal and command signal, and outputs the corresponding speed command, i.e., the speed loop input signal, through the control correction network.
[0013] The first drive module is used to receive the output signal from the control module and drive the first servo motor pump to rotate.
[0014] The second drive module is used to receive the output signal from the control module and drive the second servo motor pump to rotate.
[0015] The first servo motor pump and the second servo motor pump rotate to output pressure and flow, pushing and pulling the piston rod to extend and retract, thereby causing the load to swing according to the command.
[0016] The first rotary transformer is used to acquire the speed signal of the first servo motor pump and transmit the acquired speed signal of the first servo motor pump to the control module.
[0017] The second rotary transformer is used to acquire the second servo motor pump speed signal and transmit the acquired second servo motor pump speed signal to the control module.
[0018] The first current sensor is used to acquire the current signal of the first servo motor pump and transmit the acquired current signal of the first servo motor pump to the control module.
[0019] The second current sensor is used to acquire the current signal of the second servo motor pump and transmit the acquired current signal of the second servo motor pump to the control module.
[0020] The displacement sensor is configured in parallel with the piston rod. The displacement sensor is used to collect the extension and retraction displacement of the piston rod and transmit the collected piston rod position signal to the control module.
[0021] The first electromagnetic isolation valve is used for fault isolation of the first channel. After receiving the electrical signal from the control module, it opens the oil inlet and outlet of the first servo motor pump and separates the oil passages of the two chambers of the piston, thereby achieving fault isolation.
[0022] The second electromagnetic isolation valve is used for fault isolation of the second channel. After receiving the electrical signal from the control module, it opens the oil inlet and outlet of the second servo motor pump and separates the oil passages of the two chambers of the piston, thereby achieving fault isolation.
[0023] This invention discloses a redundancy management method for a dual-redundant electrostatic servo mechanism, comprising:
[0024] Acquire the first motor pump speed signal, the second motor pump speed signal, and the speed loop input signal;
[0025] Based on the acquired first motor pump speed signal, second motor pump speed signal and speed loop input signal, calculate the speed difference between the two servo motor pump speed signals and the speed loop input signal respectively;
[0026] The speed difference is continuously calculated in real time during the fault determination time, and the speed difference between the two servo motor pumps is determined based on the obtained speed difference to determine whether the speed difference between the two servo motor pumps is within the threshold range, thereby diagnosing the fault channel.
[0027] Based on the faulty path, implement physical isolation of the faulty path:
[0028] Based on the identified faulty path, the single-pump position loop gain parameter of the other path is adjusted to achieve system reconfiguration.
[0029] The acquisition of the first motor pump speed signal, the second motor pump speed signal, and the speed loop input signal includes:
[0030] Speed loop input signal n0: The displacement signal collected by the piston rod extension displacement sensor is converted from line to angle, and the difference is calculated with the control signal received by the dual-redundant electrostatic servo mechanism. The difference is then converted into speed loop input n0 through the correction network of the control module.
[0031] The rotational speed n1 of the first servo motor pump is obtained through the first rotary transformer of the first servo motor pump.
[0032] The rotational speed n2 of the second servo motor pump is obtained through the second rotary transformer of the second servo motor pump.
[0033] The calculation of the speed difference between the speed loop input signals of the two servo motor pumps includes:
[0034] The speed difference between the first servo motor pump and the second servo motor pump: n12=|n1-n2|;
[0035] The speed difference between the first servo motor pump and the speed loop output is: n10 = |n1 - n0|;
[0036] The speed difference between the second servo motor pump and the speed loop output is: n20 = |n2 - n0|.
[0037] The step involves determining whether the speed difference between the two servo motor pumps is within a threshold range based on the obtained speed difference, where the threshold nc for the speed difference is 20% of the highest speed.
[0038] The fault diagnosis channel includes:
[0039] The speed difference between the two servo motor pumps is calculated and compared with the speed threshold. If the speed difference does not exceed the threshold nc by 100% within a time threshold t, both channels are considered normal. If the speed difference exceeds the threshold nc by 100% within a time threshold t, one channel is determined to be abnormal. The speed difference between the two servo motor pumps is calculated with the speed loop input / output n0. If the channel speed difference exceeds the threshold nc by 100% within a time threshold t, that channel is determined to be abnormal.
[0040] The time threshold t ≤ 100ms.
[0041] The physical isolation of the faulty channel based on the faulty channel includes:
[0042] The dual redundant electrostatic servo actuator can open the electromagnetic isolation valve of the fault channel and disconnect the drive circuit of the corresponding channel. At this time, the servo motor pump of the fault channel does not consume power, and the oil inlet and outlet of the servo motor pump of the fault channel are connected through the electromagnetic isolation valve. The oil circuits of the two chambers of the piston are separated by the electromagnetic valve, so as to achieve the purpose of isolating the faulty motor pump.
[0043] The step of adjusting the single-pump position loop gain parameter of another channel based on the determined fault channel to achieve system reconfiguration includes:
[0044] Adjust the single-pump position loop gain parameters to ensure that the product performance is not degraded after fault isolation reconstruction;
[0045] After fault isolation, the position loop gain of the dual pumps is adjusted in segments based on the position loop deviation:
[0046] When the position loop deviation is greater than 40% of the position loop deviation limit, the single-pump position loop gain parameter is adjusted to 2.5 times the dual-pump position loop gain.
[0047] When the position loop deviation is less than 5% of the position loop deviation limit, adjust the single-pump position loop gain parameter to 1.5 times the dual-pump position loop gain.
[0048] When the position loop deviation is 5% to 40% of the position loop deviation limit, adjust the single-pump position loop gain parameter to twice the dual-pump position loop gain.
[0049] The advantages of this invention compared to the prior art are:
[0050] (1) This invention uses the inherent parameters in the three-loop control for fault diagnosis, without the need to install additional sensors and components, which is highly applicable, meets the lightweight requirements of aerospace servo, and avoids the risk of single-point failure of new hardware.
[0051] (2) The redundancy management method proposed in this invention mainly involves basic arithmetic operations and simple logical judgments, which have low computing power requirements for the servo control module and a fault diagnosis time of ≤100ms, thus meeting the real-time requirements and the needs of practical application.
[0052] (3) The redundancy management method proposed in this invention can effectively diagnose the faults of the drive module and servo motor pump, and can effectively isolate and reconstruct the faults so that the performance of the reconstructed product is not degraded.
[0053] (4) It is compatible with the existing dual redundant electrostatic servo mechanism hardware architecture, and can be upgraded without changing the mechanical structure, which has engineering promotion value. Attached Figure Description
[0054] Figure 1 Diagram showing the configuration of a dual-redundant electrostatic servo mechanism;
[0055] Figure 2 This is a diagram showing the configuration of the electrostatic servo mechanism after a failure.
[0056] Figure 3 This is a logic diagram of the redundancy management method. Detailed Implementation
[0057] The redundancy management method of the dual-redundant electrostatic servo mechanism of the present invention mainly utilizes the comparison between the "motor pump speed signal" and the third reference quantity "speed loop input signal" in the dual-redundant electrostatic servo mechanism to achieve fault diagnosis through threshold judgment.
[0058] The present invention relates to a dual-redundant electrostatic servo mechanism, comprising a control module, a first drive module, a second drive module, a first current sensor, a second current sensor, a first servo motor pump, a second servo motor pump, a first rotary transformer, a second rotary transformer, a first electromagnetic isolation valve, a second electromagnetic isolation valve, a piston rod, and a displacement sensor.
[0059] The first drive module, the first servo motor pump, the first current sensor, and the first rotary transformer constitute the first channel; the second drive module, the second servo motor pump, the second current sensor, and the second rotary transformer constitute the second channel.
[0060] The control module performs three-loop control of position, speed, and current through a control correction network, outputs drive signals to the first drive module and the second drive module, and controls the opening and closing of the first and second electromagnetic isolation valves; at the same time, the control module calculates the position deviation based on the received position feedback signal and command signal, and outputs the corresponding speed command, i.e., the speed loop input signal, through the control correction network.
[0061] The first drive module is used to receive the output signal from the control module and drive the first servo motor pump to rotate.
[0062] The second drive module is used to receive the output signal from the control module and drive the second servo motor pump to rotate.
[0063] The first servo motor pump and the second servo motor pump rotate to output pressure and flow, pushing and pulling the piston rod to extend and retract, thereby causing the load to swing according to the command.
[0064] The first rotary transformer is used to acquire the speed signal of the first servo motor pump and transmit the acquired speed signal of the first servo motor pump to the control module.
[0065] The second rotary transformer is used to acquire the second servo motor pump speed signal and transmit the acquired second servo motor pump speed signal to the control module.
[0066] The first current sensor is used to acquire the current signal of the first servo motor pump and transmit the acquired current signal of the first servo motor pump to the control module.
[0067] The second current sensor is used to acquire the current signal of the second servo motor pump and transmit the acquired current signal of the second servo motor pump to the control module.
[0068] The displacement sensor is configured in parallel with the piston rod. The displacement sensor is used to collect the extension and retraction displacement of the piston rod and transmit the collected piston rod position signal to the control module.
[0069] The first electromagnetic isolation valve is used for fault isolation of the first channel. After receiving the electrical signal from the control module, it opens the oil inlet and outlet of the first servo motor pump and separates the oil passages of the two chambers of the piston, thereby achieving fault isolation.
[0070] The second electromagnetic isolation valve is used for fault isolation of the second channel. After receiving the electrical signal from the control module, it opens the oil inlet and outlet of the second servo motor pump and separates the oil passages of the two chambers of the piston, thereby achieving fault isolation.
[0071] like Figure 1As shown, the dual-redundant electrostatic servo mechanism adopts a redundant architecture of "1 control module + 2 independent drive channels + 1 execution end," with the first and second channels being identical in selection. This invention enables operation even in the event of a single channel failure, ensuring system continued operation. The dual-redundant electrostatic servo mechanism uses a three-loop control algorithm of "position + speed + current" to control the extension and retraction of the piston rod, thereby driving the load to swing. Upon receiving an external control command, the displacement sensor at the piston rod collects the displacement feedback signal at the execution end. After calculating the position deviation between the two, the corresponding speed command, i.e., the speed loop input signal, is output through the control correction network. The first rotary transformer collects the rotational speed of the first servo motor pump. After calculating the speed deviation between the speed loop input signal and the rotational speed of the first servo motor pump, the corresponding current command, i.e., the first current loop input signal, is output through the control correction network. The second rotary transformer at the second servo motor pump collects the rotational speed of the second servo motor pump. After calculating the speed deviation between the speed loop input signal and the rotational speed of the second servo motor pump, the corresponding current command, i.e., the second current loop input signal, is output through the control correction network. The first current sensor collects the current signal of the first servo motor pump. After calculating the speed deviation between the first current loop input signal and the current of the first servo motor pump, a drive signal is output to drive the first servo motor pump to output pressure and flow. The second current sensor collects the current signal of the second servo motor pump. After calculating the speed deviation between the second current loop input signal and the current of the second servo motor pump, a drive signal is output to drive the second servo motor pump to output pressure and flow. The pressure and flow output by the first and second servo motor pumps together drive the load movement.
[0072] Fault diagnosis logic: The two servo motor pump speed and speed loop input signals constitute the three signals for fault diagnosis. When one motor pump fails, the speed of the servo motor pump on that line is significantly different from the other two. When the speed difference exceeds the threshold for multiple consecutive beats, it is determined that the drive module or servo motor pump on that line has failed.
[0073] like Figure 2 As shown, when a channel fails, the faulty channel is isolated using the method of this invention. Fault isolation primarily relies on the isolation function of the electromagnetic isolation valve to physically isolate the faulty channel. The electromagnetic isolation valve is typically a two-position, four-way valve that converts electrical signals into valve core movement. This valve core movement then controls the flow and direction of the hydraulic fluid to the hydraulic servo actuator, thereby isolating the system fault. The drive circuit of the corresponding channel is also disconnected. At this time, the servo motor pump in the faulty channel does not consume electrical energy, and the inlet and outlet ports of the servo motor pump in the faulty channel are connected through the electromagnetic isolation valve. The two chamber oil circuits of the piston are separated by the electromagnetic valve, achieving the purpose of isolating the faulty motor pump.
[0074] Assuming a fault occurs in the second channel, after fault isolation, the dual-redundant electrostatic servo mechanism, upon receiving an external control command, acquires the displacement feedback signal at the execution end via the displacement sensor at the piston rod. After calculating the position deviation between the two, it outputs the corresponding speed command, i.e., the speed loop input signal, through the control correction network. It also acquires the rotational speed of the servo motor pump via the first rotary transformer at the first servo motor pump. After calculating the speed deviation between the speed loop input signal and the rotational speed of the first servo motor pump, it outputs the corresponding current command, i.e., the first current loop input signal, through the control correction network. Finally, it acquires the current signal of the first servo motor pump via the first current sensor in the first servo motor pump channel. After calculating the speed deviation between the first current loop input signal and the current of the first servo motor pump, it outputs a drive signal to drive the first servo motor pump to output pressure and flow, thereby moving the load.
[0075] Assuming a fault occurs in the first channel, after fault isolation, the dual-redundant electrostatic servo mechanism, upon receiving an external control command, acquires the displacement feedback signal at the execution end via a displacement sensor at the piston rod. After calculating the position deviation between the two, it outputs the corresponding speed command, i.e., the speed loop input signal, through the control correction network. It also acquires the rotational speed of the servo motor pump via a second rotary transformer at the second servo motor pump. After calculating the speed deviation between the speed loop input signal and the second servo motor pump's rotational speed, it outputs the corresponding current command, i.e., the second current loop input signal, through the control correction network. Finally, it acquires the current signal of the second servo motor pump via a second current sensor in the second servo motor pump channel. After calculating the speed deviation between the second current loop input signal and the second servo motor pump's current, it outputs a drive signal to drive the second servo motor pump to output pressure and flow, thus moving the load.
[0076] like Figure 3 As shown, the specific steps of the method of the present invention are as follows:
[0077] Step 1: Obtain the "two motor pump speed signals" and the "speed loop input signal";
[0078] Speed loop input signal n0: The displacement signal collected by the displacement sensor at the piston rod is converted from line to angle, and then the difference is calculated with the control signal received by the dual-redundant electrostatic servo mechanism. After passing through the correction network of the control module, it is converted into speed loop input n0.
[0079] The rotational speed n1 of the first servo motor pump is obtained through the first rotary transformer of the first servo motor pump.
[0080] The rotational speed n2 of the second servo motor pump is obtained through the second rotary transformer of the second servo motor pump.
[0081] Step 2: Calculate the speed difference;
[0082] The speed difference between the first servo motor pump and the second servo motor pump: n12=|n1-n2|;
[0083] The speed difference between the first servo motor pump 1 and the speed loop output is: n10 = |n1 - n0|;
[0084] The speed difference between the second servo motor pump 2 and the speed loop output is: n20=|n2-n0|;
[0085] Step 3: Determine whether the speed difference between the two pump motors is within the threshold range;
[0086] Speed difference threshold nc: Different models of servo motor pumps have different speeds, and therefore different speed difference thresholds. It is recommended to set the value to 20% of the highest speed.
[0087] Fault determination time threshold t: Selected based on experience, generally ≤100ms;
[0088] Step 4: Diagnose faulty channels;
[0089] The speed difference between the two servo motor pumps is calculated and compared with a speed threshold. If the speed difference does not exceed the threshold nc by 100% within time t, both channels are considered normal; if the speed difference exceeds the threshold nc by 100% within time t, one channel is determined to be abnormal. Alternatively, the speed difference between the two servo motor pumps is calculated with respect to the speed loop input / output n0. If the channel speed difference exceeds the threshold nc by 100% within time t, that channel is determined to be abnormal.
[0090] Step 5: Fault Isolation:
[0091] The dual redundant electrostatic servo actuator can open the electromagnetic isolation valve of the fault channel and disconnect the drive circuit of the corresponding channel. At this time, the servo motor pump of the fault channel does not consume power, and the oil inlet and outlet of the servo motor pump of the fault channel are connected through the electromagnetic isolation valve. The oil circuits of the two chambers of the piston are separated by the electromagnetic valve to achieve the purpose of isolating the fault motor pump.
[0092] Step 6: System Restructuring
[0093] By adjusting the single-pump position loop gain parameters, the product performance is ensured not to degrade after fault isolation and reconstruction.
[0094] After fault isolation, the position loop gain of the servo motor pump is adjusted in segments based on the position loop error.
[0095] (1) When the position loop deviation is greater than 40% of the position loop deviation limit, the single pump position loop gain parameter is adjusted to 2.5 times the dual pump position loop gain to quickly compensate for the output capability and quickly solve the problem of large deviation caused by the fault channel.
[0096] (2) When the position loop deviation is less than 5% of the position loop deviation limit, adjust the single-pump position loop gain parameter to 1.5 times the dual-pump position loop gain to avoid overshoot caused by high gain.
[0097] (3) When the position loop deviation is 5% to 40% of the position loop deviation limit, adjust the single pump position loop gain parameter to twice the dual pump position loop gain.
[0098] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention based on the above-disclosed technical content without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.
Claims
1. A redundancy management method for a dual-redundant electrostatic pressure servo mechanism, characterized by, The method comprises the following steps: Obtaining a first motor pump speed signal, a second motor pump speed signal and a speed loop input signal; According to the obtained first motor pump speed signal, the second motor pump speed signal and the speed loop input signal, the speed difference of the two servo motor pumps is calculated respectively. In the fault determination time, the speed difference is continuously calculated in real time, and whether the speed difference of the two servo motor pumps is within the threshold range is determined according to the obtained speed difference, so as to diagnose the fault channel. According to the fault channel, the physical isolation of the fault channel is implemented: According to the determined fault channel, the single-pump position loop gain parameter of the other channel is adjusted to realize system reconstruction.
2. The redundancy management method of a dual-redundant electrostatic pressure servo mechanism according to claim 1, characterized by, The method comprises the following steps: The speed loop input signal n0: after the displacement signal collected by the piston rod telescopic displacement sensor is linearly converted, the difference between the converted signal and the control signal received by the double-redundancy electro-hydraulic servo mechanism is converted into the speed loop input n0 through the correction network of the control module; The speed n1 of the first servo motor pump is collected through the first rotary transformer of the first servo motor pump; The speed n2 of the second servo motor pump is collected through the second rotary transformer of the second servo motor pump.
3. The method of claim 1, wherein the method further comprises: The method comprises the following steps: The speed difference of the first servo motor pump and the second servo motor pump: n12=|n1-n2|; The speed difference between the first servo motor pump and the speed loop output: n10=|n1-n0|; The speed difference between the second servo motor pump and the speed loop output: n20=|n2-n0|.
4. The method of claim 1, wherein the method further comprises: The threshold value of the speed difference is 20% of the highest speed.
5. The method of claim 1, wherein the method further comprises: The method comprises the following steps: The speed difference of the two servo motor pumps is compared with the speed threshold value, if the speed difference does not exceed the threshold value nc by 100% within the time threshold value t, it is considered that both channels are normal, if the speed difference exceeds the threshold value nc by 100% within the time threshold value t, it is considered that one channel is abnormal, the speed difference between the two servo motor pumps and the speed loop input n0 is taken respectively, and if the speed difference exceeds the threshold value nc by 100% within t, it is considered that the channel is abnormal.
6. The method of claim 5, wherein the method further comprises: The time threshold value t is less than or equal to 100 ms.
7. The method of claim 1, wherein the method further comprises: The method comprises the following steps: The electromagnetic isolation valve of the double-redundancy electro-hydraulic servo actuator can be opened, and the drive circuit of the corresponding channel is disconnected, at this time the servo motor pump of the fault channel does not consume electric energy, and the inlet and outlet of the servo motor pump of the fault channel are connected through the electromagnetic isolation valve, and the two oil paths of the piston are separated through the electromagnetic valve, so as to isolate the fault motor pump.
8. The method of claim 1, wherein, The method comprises the following steps: Adjusting the single-pump position loop gain parameter to ensure that the performance of the product after fault isolation and reconstruction does not degrade; After fault isolation, the position loop gain of the double-pump is adjusted in a segmented manner through the position loop deviation: When the position loop deviation is greater than 40% of the position loop deviation limit value, the single-pump position loop gain parameter is adjusted to 2.5 times the double-pump position loop gain; When the position loop deviation is less than 5% of the position loop deviation limit value, the single-pump position loop gain parameter is adjusted to 1.5 times the double-pump position loop gain; When the position loop deviation is 5% to 40% of the position loop deviation limit value, the single-pump position loop gain parameter is adjusted to 2 times the double-pump position loop gain.