Zero-delay real-time hybrid test method and system based on EtherCAT-PDO mapping and application

Abstract

The invention relates to a zero-delay real-time hybrid test method and system based on EtherCAT-PDO mapping and application, and belongs to the technical field of structural engineering tests. Comprising the following steps: establishing an EtherCAT master station manager, and uniformly managing EtherCAT network resources by adopting a single example mode; the EtherCAT slave station equipment is configured to comprise a bus coupler, an analog output module and an analog input module; a straight-through zero-delay data exchange mechanism is set, and data are directly written into a PDO mapping area to realize lowest-delay transmission; a PDO data mapping mechanism is established, and real-time transmission from a numerical substructure calculation result to a physical substructure loading instruction is achieved; a multi-substructure parallel communication architecture is established, and a plurality of numerical substructures and physical substructures are supported to participate in a hybrid test at the same time. According to the method, the technical problems of data loss, overlarge delay, insufficient expansibility and the like in the existing real-time hybrid test communication method are effectively solved.

Description

TECHNICAL FIELD

[0001] The application relates to a zero-delay real-time hybrid test method, system and application based on EtherCAT-PDO (EtherCAT: Ethernet for Control Automation Technology, PDO: Process Data Object) mapping, and belongs to the technical field of structural engineering test. BACKGROUND

[0002] Real-time hybrid test is an important test method in the field of structural engineering. A part of a structure is simulated by a numerical model (numerical substructure), and another part is actually loaded by a physical test piece (physical substructure), so as to realize real-time coupling of numerical simulation and physical test. In the hybrid test process, the numerical substructure needs to transmit the calculated boundary force to the loading device of the physical substructure in real time, and the physical substructure needs to feed back the measured displacement response to the numerical substructure in real time. The real-time performance and stability of the two-way data exchange directly affect the success of the test.

[0003] At present, the data communication of real-time hybrid test mainly adopts the following ways: the first way is network communication based on UDP (User Datagram Protocol) protocol. Although the transmission speed is relatively fast, the UDP protocol itself does not guarantee the reliable transmission of data packets, and data packet loss may occur when the network load is high or there is interference, resulting in discontinuous data in the test process. The second way is network communication based on TCP / IP protocol. Although the reliability of data transmission can be guaranteed, the transmission delay is relatively large due to the protocol overhead and confirmation mechanism, and it is difficult to meet the low delay requirement of real-time hybrid test. The third way is the transmission mode based on analog signal. Digital signal and analog signal are converted through a digital-analog converter. However, analog signal is easily disturbed by electromagnetic noise, the signal processing circuit is complex, and the transmission distance and channel number are limited.

[0004] The main problems of the prior art include: the reliability of data transmission is insufficient, the inherent characteristics of network protocol affect the continuity of test; the transmission delay control is difficult, the protocol overhead affects the real-time requirement; the system scalability is limited, it is difficult to support large-scale parallel communication of multiple substructures; the anti-interference ability is insufficient, the signal quality affects the test accuracy; the system integration complexity is high, and the mixed use of multiple communication modes increases the system configuration and maintenance difficulty. SUMMARY

[0005] In view of the above defects existing in the prior art, the application provides a zero-delay real-time hybrid test method, system and application based on EtherCAT-PDO mapping, which establishes an efficient, stable and zero-delay EtherCAT-PDO data mapping communication network, and solves the technical problems of data loss, excessive delay and insufficient expansibility existing in the existing real-time hybrid test communication method.

[0006] In order to achieve the above object, the technical scheme adopted by the application is as follows:

[0007] A zero-delay real-time hybrid test method based on EtherCAT-PDO (Ethernet for Control Automation Technology) mapping, comprising a numerical substructure and a physical substructure, comprising the following steps:

[0008] An EtherCAT master controller is established as the communication hub of the real-time hybrid test system;

[0009] A plurality of EtherCAT slave devices are configured, including a bus coupler, an analog output module and an analog input module, to form an EtherCAT network topology;

[0010] A PDO (Process Data Object) data mapping mechanism is established to transmit the calculation results of the numerical substructure to the loading device of the physical substructure in real time through the EtherCAT network;

[0011] A zero-delay data exchange mechanism is set to realize the lowest delay data transmission between the numerical substructure and the physical substructure;

[0012] Parallel communication of multiple substructures is realized to support multiple numerical substructures and physical substructures to exchange data through the same EtherCAT network at the same time.

[0013] Further, the EtherCAT master controller adopts a singleton mode design, and the EtherCAT network resources are uniformly managed by a global manager to avoid resource conflicts between multiple communication instances.

[0014] Further, the configuration of the EtherCAT slave device comprises:

[0015] The bus coupler serves as a network starting node and is responsible for coupling and converting EtherCAT network signals;

[0016] The multi-channel analog output module is responsible for converting digital signals into analog voltage signal outputs;

[0017] The multi-channel analog input module is responsible for converting analog voltage signals into digital signal inputs.

[0018] Further, the PDO data mapping mechanism comprises:

[0019] Establishing a direct mapping relationship of numerical substructure output data to analog output module;

[0020] Establishing a direct mapping relationship of analog input module to numerical substructure input data;

[0021] Using high-precision digital values to represent voltage ranges, realizing linear conversion between digital signals and analog voltages.

[0022] Further, the pass-through zero-delay data exchange mechanism comprises:

[0023] Directly writing data into the PDO mapping area to realize real-time data transmission with the lowest delay;

[0024] Immediately performing EtherCAT data sending and receiving operations;

[0025] Skipping intermediate buffering steps and directly performing data mapping and conversion.

[0026] Further, the multi-substructure parallel communication supports the following topologies:

[0027] Multiple numerical substructures are connected to the same EtherCAT master controller and share network resources;

[0028] Multiple physical substructures are connected to different slave devices in the same EtherCAT network;

[0029] Supporting arbitrary data routing configuration between numerical substructures and physical substructures.

[0030] Further, it also includes real-time performance optimization measures:

[0031] Setting high frequency operation of EtherCAT network to ensure high time resolution of data exchange;

[0032] Using real-time operating system scheduling to assign high priority to EtherCAT communication tasks;

[0033] Using atomic operations and lock-free data structures to reduce thread synchronization overhead;

[0034] It also includes the following safety protection measures:

[0035] Voltage output limitation: strictly limiting analog output voltage within a safe range;

[0036] Communication timeout detection: automatically switching to a safe state when EtherCAT communication times out;

[0037] Slave state check: Regularly check the running state of slave devices, and alarm in time when abnormalities are found;

[0038] Support dynamic configuration management:

[0039] Dynamic adjustment of running frequency: Adjust the running frequency of the EtherCAT network in real time according to the test requirements;

[0040] Dynamic configuration of channel mapping: Support reconfiguring the mapping relationship of data channels during the test process;

[0041] Dynamic expansion of network topology: Support adding or reducing slave devices in real time.

[0042] An EtherCAT-PDO mapping-based zero-delay real-time hybrid test system for implementing the above-mentioned EtherCAT-PDO mapping-based zero-delay real-time hybrid test method, comprising:

[0043] EtherCAT master controller, configured with EtherCAT master manager, responsible for the initialization and data exchange control of the whole network;

[0044] EtherCAT slave device group, including bus coupler, multi-channel analog output module and multi-channel analog input module;

[0045] PDO data processing module, realizing real-time mapping and conversion of PDO data;

[0046] Zero-delay communication module, supporting real-time data transmission with the lowest delay;

[0047] The EtherCAT master controller further comprises:

[0048] Network state monitoring module, real-time monitoring the running state of slave devices;

[0049] Error detection and recovery module, automatically performing recovery operation when communication error is detected;

[0050] Performance statistics module, recording performance indicators such as data transmission delay and success rate.

[0051] Further, the PDO data processing module supports the following data processing functions:

[0052] Digital conversion of voltage signal, supporting linear mapping of voltage range;

[0053] Data timestamp marking, recording the generation and processing time of each data packet;

[0054] Data sequence number management, ensuring the correct order and integrity of data packets;

[0055] The system also supports various network topology deployments:

[0056] Linear topology: all slave devices are connected in series;

[0057] Star topology: slave devices are connected to the master through a switch;

[0058] Tree topology: supports branch network structure, suitable for complex multi-substructure configuration.

[0059] The application of the above-mentioned zero-delay real-time hybrid test method based on EtherCAT-PDO mapping is suitable for the following application scenarios:

[0060] Real-time hybrid test of seismic performance of building structure, real-time hybrid test of dynamic response of bridge structure, real-time hybrid test of vibration control of mechanical equipment, or coordinated loading test of multi-degree-of-freedom complex structure.

[0061] After adopting the above technical solutions, the present application has at least one of the following beneficial effects compared with the prior art:

[0062] (1) High communication stability: EtherCAT protocol adopts ring topology and time synchronization mechanism, avoiding the data packet loss problem of UDP protocol, ensuring the reliability of data transmission;

[0063] (2) Low transmission delay: PDO data exchange delay is significantly lower than TCP / IP protocol, meeting the strict time requirements of real-time hybrid test;

[0064] (3) Strong scalability: supports a large number of slave devices, can realize complex multi-substructure hybrid test, greatly expands the scale and complexity of the test system;

[0065] (4) Strong anti-interference ability: digital signal transmission avoids the noise interference problem of analog signal, improves the accuracy and stability of data transmission;

[0066] (5) Flexible deployment: supports linear, star, tree and other network topologies, adapts to different test site and equipment layout requirements;

[0067] (6) High cost-effectiveness: one master can manage multiple substructures at the same time, compared with traditional solutions, reduces the number of hardware devices, reduces the overall system cost. BRIEF DESCRIPTION OF DRAWINGS

[0068] Figure 1 is the overall architecture diagram of the zero-delay real-time hybrid test system based on EtherCAT-PDO mapping of the present application;

[0069] Figure 2is a schematic diagram of an EtherCAT network topology of the present application;

[0070] Figure 3 is a flow chart of a direct zero-delay data exchange mechanism of the present application;

[0071] Figure 4 is a schematic diagram of a PDO data mapping mechanism of the present application;

[0072] Figure 5 is a schematic diagram of a multi-substructure parallel communication architecture of the present application. DETAILED DESCRIPTION

[0073] The present application will be further described in conjunction with the accompanying drawings and specific embodiments, so as to facilitate clear understanding of the present application, but they do not constitute limitation of the present application. Figures 1-5 The present application will be further described in conjunction with the accompanying drawings and specific embodiments, so as to facilitate clear understanding of the present application, but they do not constitute limitation of the present application.

[0074] In the description of the present application, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0075] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0076] Example 1

[0077] The zero-delay real-time hybrid test method based on EtherCAT-PDO mapping of the present embodiment includes a numerical substructure and a physical substructure, and includes the following steps:

[0078] An EtherCAT master controller is established as the communication hub of the real-time hybrid test system; the EtherCAT master controller is designed in a singleton mode, and the EtherCAT network resources are uniformly managed by a global manager to avoid resource conflicts between multiple communication instances.

[0079] A plurality of EtherCAT slave devices are configured, including a bus coupler, an analog output module and an analog input module, to form an EtherCAT network topology; the configuration of the EtherCAT slave device includes:

[0080] The bus coupler, as a network starting node, is responsible for coupling and converting EtherCAT network signals;

[0081] The multi-channel analog output module is responsible for converting digital signals into analog voltage signals for output;

[0082] The multi-channel analog input module is responsible for converting analog voltage signals into digital signals for input.

[0083] A PDO data mapping mechanism is established to transmit the calculation results of the numerical substructure to the loading device of the physical substructure in real time through the EtherCAT network; the PDO data mapping mechanism includes:

[0084] A direct mapping relationship between the numerical substructure output data and the analog output module is established;

[0085] A direct mapping relationship between the analog input module and the numerical substructure input data is established;

[0086] A high-precision digital value is used to represent the voltage range, realizing linear conversion between digital signals and analog voltages.

[0087] A zero-delay data switching mechanism is set up to realize the lowest delay data transmission between the numerical substructure and the physical substructure; the zero-delay data switching mechanism includes:

[0088] Data is directly written into the PDO mapping area to realize real-time data transmission with the lowest delay;

[0089] EtherCAT data sending and receiving operations are immediately executed;

[0090] The intermediate buffering link is skipped, and data mapping and conversion are directly performed.

[0091] Multi-substructure parallel communication is realized to support multiple numerical substructures and physical substructures to exchange data through the same EtherCAT network at the same time. The multi-substructure parallel communication supports the following topological structures:

[0092] Multiple numerical substructures are connected to the same EtherCAT master controller and share network resources;

[0093] Multiple physical substructures are connected to different slave devices of the same EtherCAT network;

[0094] Any data routing configuration between the numerical substructure and the physical substructure is supported.

[0095] Further, real-time performance optimization measures are also included:

[0096] Set EtherCAT network high frequency operation, ensure the high time resolution of data exchange;

[0097] Using real-time operating system scheduling, assign high priority to EtherCAT communication tasks;

[0098] Using atomic operations and lock-free data structures, reduce thread synchronization overhead;

[0099] Also includes the following safety protection measures:

[0100] Voltage output limit: strictly limit the analog output voltage within the safe range;

[0101] Communication timeout detection: automatically switch to a safe state when EtherCAT communication times out;

[0102] Slave state check: regularly check the running state of the slave device, and alarm in time when an exception is found;

[0103] Support dynamic configuration management:

[0104] Running frequency dynamic adjustment: adjust the running frequency of the EtherCAT network in real time according to the test requirements;

[0105] Channel mapping dynamic configuration: support reconfiguring the mapping relationship of data channels during the test process;

[0106] Network topology dynamic expansion: support adding or reducing slave devices in real time.

[0107] Embodiment 2

[0108] One embodiment of the zero-delay real-time hybrid test system based on EtherCAT-PDO mapping is used to implement the zero-delay real-time hybrid test method based on EtherCAT-PDO mapping as claimed in the preceding embodiment, which comprises:

[0109] EtherCAT master controller, configured with EtherCAT master manager, responsible for the initialization and data exchange control of the entire network; wherein, the EtherCAT master controller further comprises:

[0110] Network state monitoring module, which monitors the running state of the slave device in real time;

[0111] Error detection and recovery module, which automatically performs recovery operation when communication error is detected;

[0112] Performance statistics module, which records performance indicators such as data transmission delay and success rate.

[0113] EtherCAT slave device group, including bus coupler, multi-channel analog output module and multi-channel analog input module;

[0114] PDO data processing module, which realizes real-time mapping and conversion of PDO data; the PDO data processing module supports the following data processing functions:

[0115] Digital conversion of voltage signal, supporting linear mapping of voltage range;

[0116] Data timestamp marking, recording the generation and processing time of each data packet;

[0117] Data sequence number management, ensuring the correct order and integrity of data packets;

[0118] Zero delay communication module, supporting real-time data transmission with the lowest delay;

[0119] In this embodiment, the system also supports deployment of various network topologies:

[0120] Linear topology: all slave devices are connected in series;

[0121] Star topology: slave devices are connected to the master station through a switch;

[0122] Tree topology: supports branch network structure, suitable for complex multi-substructure configuration.

[0123] Embodiment 3

[0124] An embodiment of the zero-delay real-time hybrid test method based on EtherCAT-PDO mapping of embodiment 1 is applied, which is suitable for the following application scenarios:

[0125] Real-time hybrid test of seismic performance of building structure, real-time hybrid test of bridge structure dynamic response, real-time hybrid test of mechanical equipment vibration control, or coordinated loading test of multi-degree-of-freedom complex structure.

[0126] Embodiment 4

[0127] As shown in the accompanying Figures 1-5 The embodiment provides a zero-delay real-time hybrid test system and method based on EtherCAT-PDO mapping, which is used for real-time hybrid test of seismic performance of building structure, and specifically as follows.

[0128] (1) Basic EtherCAT communication network establishment

[0129] As Figure 1As shown, the embodiment provides a basic configuration of a zero-delay real-time hybrid test system based on EtherCAT-PDO mapping. The system includes an EtherCAT master controller 1, a bus coupler 2, a multi-channel analog output module 3, a multi-channel analog input module 4, a numerical substructure 5 (i.e., a numerical substructure calculation node), and a physical substructure 6 (i.e., a physical substructure test device).

[0130] The EtherCAT master controller 1 runs on an industrial computer configured with a real-time operating system. The master controller is connected to the bus coupler 2 through an Ethernet cable to establish the starting node of the EtherCAT network.

[0131] The bus coupler 2 serves as the first network node, responsible for electrical isolation and signal integrity assurance of the EtherCAT signal. The multi-channel analog output module 3 serves as the second network node, providing multiple independent analog output channels, each supporting voltage output with high resolution and fast response capability. The multi-channel analog input module 4 serves as the third network node, providing multiple independent analog input channels, each supporting voltage input with high precision and low noise characteristics.

[0132] The numerical substructure 5 runs structural analysis software and is responsible for calculating the numerical response of the structure. The physical substructure 6 includes loading devices, force sensors, displacement sensors, acceleration sensors, etc., and is responsible for actual loading and response measurement of the physical test specimen.

[0133] The establishment process of the EtherCAT network is as follows:

[0134] Step 1: The master controller calls the network initialization function to initialize the EtherCAT master, with the network card interface name as the parameter;

[0135] Step 2: Call the device configuration function to automatically discover and configure the slave devices. The system automatically identifies the bus coupler, analog output module, analog input module, etc., as slave stations;

[0136] Step 3: Call the data mapping function to establish PDO mapping and map the data buffer to the input and output data of the slave stations;

[0137] Step 4: Call the state checking function to switch all slave stations to the pre-operation state, preparing to enter the operation mode;

[0138] Step 5: Set the master station to the operation state and start normal data exchange.

[0139] This configuration realizes the basic EtherCAT communication network, laying the foundation for subsequent data exchange.

[0140] (2) PDO data mapping and conversion mechanism

[0141] As Figure 4 shown, this embodiment details the specific implementation of the PDO data mapping and conversion mechanism.

[0142] For analog output channels (data transmission from numerical substructure to physical substructure):

[0143] The numerical substructure calculates the control command F, which needs to be converted to voltage value V, and the conversion formula is:

[0144] V = F × K_scale, where K_scale is the calibration coefficient;

[0145] The voltage value V is further converted to digital value D, and the conversion formula is:

[0146] D = Max_Value × (V / V_max), to ensure linear conversion within the voltage range;

[0147] The digital value D is directly written into the output register of the analog output module through PDO mapping.

[0148] For analog input channels (data transmission from physical substructure to numerical substructure):

[0149] Read the digital value from the input register of the analog input module;

[0150] Convert the digital value to voltage value:

[0151] voltage = V_max × (raw / Max_Value);

[0152] Convert the voltage value to physical quantity (such as displacement value):

[0153] physical_value = voltage × K_sensor, where K_sensor is the sensor calibration coefficient.

[0154] This mapping mechanism realizes the direct conversion between numerical calculation results and physical measurement data, ensuring high precision and real-time data.

[0155] (3) Zero-delay data switch mechanism

[0156] As Figure 3 shown, this embodiment realizes the zero-delay data switch mechanism, ensuring the lowest delay data transmission between numerical substructure and physical substructure.

[0157] Implementation of zero-delay mode:

[0158] Data is directly written into the PDO mapping area:

[0159] Directly write voltage data into PDO mapping area, skip intermediate buffer link;

[0160] Immediately call data sending function to transmit data to EtherCAT hardware;

[0161] Update current value cache for data continuity maintenance.

[0162] Directly read data from PDO mapping area:

[0163] Immediately call data receiving function to get the latest data from EtherCAT hardware;

[0164] Directly read original digital value from PDO mapping area;

[0165] Perform voltage conversion and physical quantity calibration to obtain actual measurement value.

[0166] This mechanism realizes the lowest delay of data processing by skipping intermediate data cache, meeting the strict requirements of time accuracy of real-time hybrid test.

[0167] (4) Multi-substructure parallel communication

[0168] As shown in Figure 5 , the embodiment realizes multi-substructure parallel communication architecture, supporting multiple numerical substructures and physical substructures to exchange data simultaneously.

[0169] System configuration includes: multiple numerical substructure nodes, multiple physical substructure nodes, and coordinated communication through one EtherCAT master station.

[0170] Data routing configuration:

[0171] Numerical substructure 1 output → analog output module channel group 1 → physical substructure 1 loader

[0172] Physical substructure 1 sensor → analog input module channel group 1 → numerical substructure 1 input

[0173] Numerical substructure 2 output → analog output module channel group 2 → physical substructure 2 loader

[0174] Physical substructure 2 sensor → analog input module channel group 2 → numerical substructure 2 input

[0175] Time synchronization mechanism:

[0176] All substructure nodes adopt a unified time step;

[0177] EtherCAT network running frequency is set to high frequency mode to ensure data exchange and time step synchronization;

[0178] High-precision time synchronization is achieved using the distributed clock function of EtherCAT.

[0179] Data exchange process:

[0180] Step 1: Numerical calculation is performed in parallel for each numerical substructure.

[0181] Step 2: The calculation results are transmitted synchronously to the corresponding physical substructure through the EtherCAT network.

[0182] Step 3: Physical loading and response measurement are performed in parallel for each physical substructure.

[0183] Step 4: The measurement results are fed back synchronously to the corresponding numerical substructure through the EtherCAT network.

[0184] Step 5: Repeat the above process to achieve continuous hybrid testing.

[0185] (5) Real-time performance optimization

[0186] This embodiment focuses on the real-time performance optimization measures of the system.

[0187] Real-time operating system configuration:

[0188] Use an operating system kernel that supports real-time scheduling;

[0189] Set the priority of the EtherCAT communication thread to the highest priority to ensure real-time data processing;

[0190] Adopt a preemptive scheduling strategy to ensure timely execution of EtherCAT tasks.

[0191] Memory management optimization:

[0192] Lock the memory pages of critical data structures to avoid delays caused by memory swapping;

[0193] Pre-allocate all data structures to avoid uncertain delays caused by runtime memory allocation;

[0194] Use continuous memory space to store PDO data to improve data access efficiency.

[0195] Lock-free data structure:

[0196] Use atomic variables to achieve lock-free data access to avoid blocking delays caused by mutexes;

[0197] Use lock-free queues and buffers to achieve efficient data transmission;

[0198] Ensure data consistency through hardware atomic operations.

[0199] Through the above optimization measures, the system realizes stable high-frequency data exchange, and the single data exchange delay is controlled within the microsecond level, meeting the strict time requirements of real-time hybrid testing.

[0200] (6) Safety protection and error handling

[0201] This example illustrates the safety protection mechanism and error handling strategy of the system.

[0202] Voltage output limit:

[0203] All analog output voltages are strictly limited within the set safety range;

[0204] Through software and hardware double protection, prevent output voltage from exceeding the safety range;

[0205] When an abnormal voltage is detected, immediately switch to a safe state.

[0206] Communication timeout detection:

[0207] Set the EtherCAT communication timeout time to monitor the network communication state;

[0208] When the communication is timed out, automatically enter the safety state and stop all outputs;

[0209] Record communication failure information for fault diagnosis and recovery.

[0210] Slave state monitoring:

[0211] Periodically check the running state and health status of the slave device;

[0212] Monitor the operation state, error flag and diagnostic information of the slave;

[0213] When an abnormal slave is found, timely alarm and take protective measures.

[0214] Error recovery mechanism:

[0215] When a slave error is detected, automatically attempt to reinitialize and recover;

[0216] Provide multi-level error recovery strategy, from minor faults to serious faults;

[0217] Record error history and recovery process for system maintenance.

[0218] (7) Performance test and verification

[0219] This example shows the results of system performance testing and verification methods.

[0220] Delay test:

[0221] Data transmission delay is measured using high-precision time measurement method;

[0222] The test includes the complete process of data sending, network transmission, hardware processing and data receiving; the test result shows that the average data transmission delay is significantly lower than that of the traditional communication method;

[0223] The delay stability is good, meeting the time requirements of real-time hybrid test.

[0224] Stability test:

[0225] Long-time continuous operation test is carried out to verify the stability of the system;

[0226] Data transmission remains continuous during the test, without communication interruption;

[0227] The stable operation of the system proves the high reliability of the EtherCAT protocol.

[0228] Multi-substructure scalability test:

[0229] The parallel communication capability of multiple numerical substructures and physical substructures is tested;

[0230] The stable operation of the system under the multi-substructure configuration is verified;

[0231] The network load is reasonable, verifying the good scalability of the system.

[0232] The comparison test results with the traditional method show that the method based on the EtherCAT protocol is superior to the UDP and TCP / IP methods in terms of delay, stability and scalability, and is suitable as a communication solution for real-time hybrid test.

[0233] The above is only the preferred embodiment of the present application, and does not limit the structure of the present application in any form. The arrangement and the number of uses of the present application are not limited to the above, and can be optimized according to the actual engineering. Any modification, equivalent change and decoration of the above embodiment according to the technical principle of the present application, without departing from the technical scheme of the present application, are still within the scope of the technical scheme of the present application.

Claims

1. A zero-latency real-time hybrid test method based on EtherCAT-PDO mapping, comprising a numerical substructure and a physical substructure, characterized in that, The method comprises the following steps: An EtherCAT master controller is established as the communication hub of the real-time hybrid test system; A plurality of EtherCAT slave devices are configured, including a bus coupler, an analog output module and an analog input module, to form an EtherCAT network topology; A PDO data mapping mechanism is established to transmit the calculation results of the numerical substructure to the loading device of the physical substructure in real time through the EtherCAT network; A zero-delay data switching mechanism is set to realize the lowest delay data transmission between the numerical substructure and the physical substructure; Parallel communication of multiple substructures is realized to support multiple numerical substructures and physical substructures to exchange data through the same EtherCAT network at the same time.

2. The zero-latency real-time hybrid test method based on EtherCAT-PDO mapping according to claim 1, characterized in that: The EtherCAT master controller is designed in a singleton mode, and the EtherCAT network resources are uniformly managed by a global manager to avoid resource conflicts between multiple communication instances.

3. The zero-latency real-time hybrid test method based on EtherCAT-PDO mapping according to claim 2, characterized in that, The configuration of the EtherCAT slave device comprises: The bus coupler serves as a network starting node and is responsible for coupling and converting EtherCAT network signals; The multi-channel analog output module is responsible for converting digital signals into analog voltage signals for output; The multi-channel analog input module is responsible for converting analog voltage signals into digital signals for input.

4. The zero-latency real-time hybrid test method based on EtherCAT-PDO mapping according to claim 3, characterized in that, The PDO data mapping mechanism comprises: A direct mapping relationship is established between the output data of the numerical substructure and the analog output module; A direct mapping relationship is established between the analog input module and the input data of the numerical substructure; A high-precision digital value is used to represent the voltage range to realize linear conversion of digital signals and analog voltage.

5. The EtherCAT-PDO mapping based zero-latency real-time hybrid test method according to claim 4, wherein, The zero-delay data switching mechanism comprises: Data is directly written into the PDO mapping area to realize real-time data transmission with the lowest delay; EtherCAT data sending and receiving operations are immediately executed; Data mapping and conversion are directly performed without intermediate buffering.

6. The EtherCAT-PDO mapping based zero-latency real-time hybrid test method according to claim 5, wherein, The parallel communication of multiple substructures supports the following topologies: Multiple numerical substructures are connected to the same EtherCAT master controller to share network resources; Multiple physical substructures are connected to different slave devices of the same EtherCAT network; Any data routing configuration between the numerical substructure and the physical substructure is supported.

7. The zero-delay real-time hybrid test method based on EtherCAT-PDO mapping according to claim 1, further comprising real-time performance optimization measures: An EtherCAT network with high frequency is set to ensure high time resolution of data exchange; A real-time operating system is used to schedule and assign high priority to EtherCAT communication tasks; Atomic operations and lock-free data structures are used to reduce thread synchronization overhead; The following safety protection measures are also included: Voltage output limitation: strictly limit the analog output voltage within a safe range; Communication timeout detection: automatically switch to a safe state when EtherCAT communication times out; Slave state checking: periodically check the running state of the slave device and alarm in time when an abnormality is found; Dynamic configuration management is supported: Running frequency is dynamically adjusted according to test requirements in real time; ​ Channel mapping dynamic configuration: support reconfiguring the mapping relationship of data channels during the test process; Network topology dynamic expansion: support increasing or decreasing slave devices at runtime.

8. An EtherCAT-PDO mapping based zero-latency real-time hybrid test system for implementing the EtherCAT-PDO mapping based zero-latency real-time hybrid test method of any one of claims 1-7, characterized in that, Comprise: EtherCAT master controller, configured with EtherCAT master manager, responsible for the initialization and data exchange control of the whole network; EtherCAT slave device group, including bus coupler, multi-channel analog output module and multi-channel analog input module; PDO data processing module, realizing real-time mapping and conversion of PDO data; Zero-delay communication module, supporting real-time data transmission with minimum delay; The EtherCAT master controller further comprises: Network state monitoring module, real-time monitoring the running state of slave devices; Error detection and recovery module, automatically performing recovery operation when detecting communication error; Performance statistics module, recording performance indicators such as data transmission delay and success rate.

9. The zero-delay real-time hybrid test system based on EtherCAT-PDO mapping according to claim 8, wherein: The PDO data processing module supports the following data processing functions: Digital conversion of voltage signal, supporting linear mapping of voltage range; Data timestamp marking, recording the generation and processing time of each data packet; Data sequence number management, ensuring the correct order and integrity of data packets; The system also supports multiple network topology structures: Linear topology: all slave devices are connected in series; Star topology: slave devices are connected to the master through a switch; Tree topology: supports branch network structure, suitable for complex multi-substructure configuration.

10. Use of the zero-latency real-time hybrid test method based on EtherCAT-PDO mapping according to any one of claims 1 to 7, characterized in that, This method is suitable for the following application scenarios: Real-time hybrid test of seismic performance of building structure, real-time hybrid test of bridge structure dynamic response, real-time hybrid test of mechanical equipment vibration control or coordinated loading test of multi-degree-of-freedom complex structure.

Images