Electromagnetic relay control method and system based on programmable controller

Abstract

The application relates to the technical field of electromagnetic relay control, and discloses an electromagnetic relay control method and system based on a programmable controller, which realizes real-time extraction of a target relay coil dynamic baseline impedance under a non-driven state, collects transient power supply voltage and transient current when an action instruction is received, constructs a crosstalk suppression matrix in combination with the coil transient current change rate of adjacent relays, synchronously deducts internal impedance voltage drop and a space magnetic coupling induced electromotive force, solves a back electromotive force representing a real displacement state, accurately maps the back electromotive force into a real-time air gap position of an armature, cuts off a forward drive and applies a reverse brake voltage pulse when a position parameter reaches a preset critical threshold, generates an electromagnetic brake torque to attenuate armature kinetic energy, realizes soft landing of contacts, extracts a transient mechanical characteristic to calculate a health deviation index after physical closure, generates a compensation coefficient to update subsequent period control parameter execution structure wear compensation when it is confirmed that an alarm threshold is not reached.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic relay control technology, specifically to an electromagnetic relay control method and system based on a programmable logic controller (PLC). Background Technology

[0002] In industrial automation control systems, programmable logic controllers (PLCs) typically drive electromagnetic relay arrays by outputting switching signals. During the closing process of electromagnetic relays, the armature often strikes the stationary contact with high kinetic energy, causing mechanical bounce and arc erosion, which drastically shortens the electrical life of the contact. To suppress contact bounce, conventional sensorless control strategies usually attempt to extract the back electromotive force inside the coil to indirectly calculate the real-time movement position of the armature, and then apply electrical braking before the contact closes to achieve a soft landing.

[0003] However, the physical environment of actual industrial sites makes the extraction of pure back EMF subject to complex interference. The DC resistance and static inductance of the coil itself will dynamically drift with Joule heating, masking the real and weak motion back EMF signal. In addition, the relays inside modern input and output modules often adopt a high-density side-by-side mounting layout. When adjacent relays operate frequently, the alternating magnetic field generated will penetrate the physical space and induce a magnetic coupling EMF inside the target relay coil.

[0004] Because the back EMF parameter acquired at the front end has been severely contaminated by thermal drift and spatial magnetic field, the real-time air gap position of the armature mapped by the control system will inevitably be distorted. The signal distortion makes it difficult for the controller to accurately capture the critical spatial node used to trigger the reverse braking operation. It is very easy for the braking pulse to intervene too early, causing the engagement to stop midway, or to intervene too late, completely losing the effect of eliminating mechanical collisions and causing runaway phenomena. Under long-term operation, the reaction spring of the relay and the mechanical hinge will inevitably suffer fatigue wear. The existing drive system only relies on the factory-fixed control parameters to execute open-loop output, making it difficult to extract the damping change characteristics during each action. Ultimately, it is difficult to provide any predictive maintenance warnings before the equipment experiences substantial jamming or sticking. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an electromagnetic relay control method and system based on a programmable controller. This solves the problems of existing control systems that fail to decouple and eliminate the distortion of characteristic signals caused by internal impedance drift and electromagnetic crosstalk between adjacent coils, resulting in the inaccurate timing of reverse braking triggering and difficulty in achieving soft landing of the contacts, and the lack of an adaptive compensation mechanism for mechanical wear conditions.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] In a first aspect, this invention provides an electromagnetic relay control method based on a programmable logic controller (PLC), which is executed within a two-layer decoupled control architecture based on a time-sensitive network (TSN). The PLC acts as the main controller, issuing action commands and a parameter matrix containing control parameters. The underlying edge input / output module receives the action commands and, independent of the PLC's main scan cycle, independently performs high-frequency sampling and waveform reconstruction within a local timing cycle independent of the main scan cycle. The control method includes the following steps:

[0008] In the non-driven state, the dynamic baseline impedance of the target relay coil is extracted in real time. Specifically, an orthogonal high-frequency probe carrier voltage is continuously or periodically injected into the target relay coil. The amplitude of this carrier voltage is limited to below the critical starting energy threshold that triggers mechanical action of the armature. Subsequently, the steady-state response current of the target relay coil to this carrier voltage is sampled synchronously. The system combines the orthogonal high-frequency probe carrier voltage and the steady-state response current to calculate the complex impedance magnitude and phase difference, and further calculates the dynamic DC resistance and static inductance to characterize the dynamic baseline impedance. The innovative principle of this step is that by obtaining the dynamic DC resistance and static inductance through a low-energy high-frequency probe carrier, the system is provided with a baseline physical zero-point calibration basis that reflects the influence of the current ambient temperature and the remanence of the iron core, eliminating physical interference caused by thermodynamic drift.

[0009] Upon receiving an action command, the system acquires the transient supply voltage and transient current of the target relay coil. Combining this with the dynamic baseline impedance and the spatial magnetic coupling induced electromotive force (EMF) generated by the coils of adjacent relays, it calculates the true back EMF after eliminating the spatial magnetic coupling induced EMF. During this process, the system simultaneously acquires the transient current change rate of the coils of adjacent relays and constructs a spatial magnetic coupling crosstalk suppression matrix based on the spatial mutual inductance coefficient between the target relay and adjacent relays. The innovative principle of this step lies in using differential algebraic operations to purify the electrical data into electrical quantities that only reflect the armature displacement of the target relay. The specific physical equation for calculating the true back EMF after eliminating the spatial magnetic coupling induced EMF is as follows:

[0010]

[0011] In the formula, This represents the true back electromotive force after removing the spatial magnetic coupling induced electromotive force. This represents the transient supply voltage of the target relay coil, synchronously acquired by the edge input / output module. This represents the transient current in the target relay coil; This represents the dynamic DC resistance calculated and extracted in the preceding steps; This represents the static inductance calculated and extracted in the preceding steps; This represents the rate of change of the transient current of the target relay; This indicates the total number of adjacent relays within a preset Euclidean distance range that are affected by electromagnetic crosstalk; From 1 to An incrementing integer variable; Indicates the target relay coil and the first The spatial mutual inductance coefficient of adjacent relay coils is a constant that is pre-simulated and calculated using finite element electromagnetic simulation software during the factory manufacturing stage. Indicates the number of synchronously acquired data. The rate of change of transient current of adjacent relays.

[0012] After obtaining the true back electromotive force, it is mapped to the real-time motion state of the target relay armature. The system maps the true back electromotive force to the real-time motion velocity of the armature by using a pre-calibrated position-associated electromagnetic coefficient (i.e., the rate of change constant of the flux linkage with respect to the air gap displacement); then, by combining the time integral value of the initial stationary air gap and the real-time motion velocity, the real-time air gap position of the armature is obtained as a position parameter, and the real-time motion acceleration is obtained by taking the time derivative of the real-time motion velocity.

[0013] When the position parameters in the real-time motion state reach a preset critical position threshold, a reverse braking voltage pulse is applied to the target relay coil based on preset control parameters to achieve a soft landing of the contacts. Specifically, the system continuously monitors the real-time air gap position. When this position is less than or equal to the preset critical position threshold, the forward drive voltage is immediately cut off. Simultaneously, based on the real-time motion speed, real-time motion acceleration, and the feedback gain coefficient as a control parameter, a reverse braking voltage pulse is calculated and output to generate a reverse electromagnetic braking torque in the magnetic circuit opposite to the direction of armature motion, thereby reducing the kinetic energy of the armature. This control strategy completely changes the traditional open-loop blind operation mode of relays. Without the intervention of external displacement sensors, it eliminates mechanical collisions and contact bounce through precise damping control of electromagnetic force.

[0014] After the mechanical action corresponding to the action command is completed, transient mechanical features are extracted to assess the health status, and control parameters are adaptively updated. The system extracts the pull-in delay time and kinetic energy damping attenuation coefficient from the recorded transient process of a single mechanical action as transient mechanical features. These transient mechanical features are compared with a preset standard delay time and standard attenuation coefficient based on historical test bench statistics, and a health deviation index is calculated using normalized weighting coefficients to quantify the degree of degradation. When the health deviation index is less than the safety alarm threshold, a compensation coefficient is generated to cover and update the feedback gain coefficient for the next action cycle; when the health deviation index is greater than or equal to the safety alarm threshold, a warning signal frame containing the device's media access control address is generated and pushed to the host computer along with the specific port index for predictive maintenance. This completes the parameter adaptive closed-loop iteration for physical wear compensation throughout the relay's entire lifecycle.

[0015] In a second aspect, this invention provides an electromagnetic relay control system based on a programmable logic controller (PLC). The system includes a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor, as the core of the hardware computation, has an internal hardware coprocessor capable of performing complex calculations. The memory consists of a read-only flash memory chip with pre-calibrated constants and a local random access memory (RAM) for caching transient data during operation. When the processor executes the computer program, it establishes a data synchronization link via a control network communication interface, reads electrical parameters using an analog-to-digital converter (ADC), and executes the steps of the aforementioned PLC-based electromagnetic relay control method, thereby completing the aforementioned multi-dimensional feature decoupling and flexible braking logic using physical hardware units.

[0016] This invention provides an electromagnetic relay control method and system based on a programmable logic controller (PLC). It offers the following advantages:

[0017] 1. In this invention, dynamic baseline impedance is extracted by injecting orthogonal high-frequency probe carriers, and crosstalk suppression matrix is ​​constructed by collecting transient current change rates of adjacent coils in a coordinated manner. The impedance voltage drop and spatial magnetic coupling induced electromotive force are simultaneously subtracted from the supply voltage to calculate the parameter that characterizes only the back electromotive force of the armature displacement.

[0018] 2. In this invention, the back electromotive force parameter is mapped to the real-time air gap position of the armature, and the forward driving voltage is cut off when the value reaches the critical threshold. The reverse braking voltage pulse is output according to the real-time movement speed and control parameters to generate a reverse electromagnetic braking torque, which attenuates the kinetic energy of the armature and causes the moving and stationary contacts to complete the closing action in a zero-speed state.

[0019] 3. In this invention, after the contact is closed, the transient process pull-in delay time and kinetic energy damping attenuation coefficient are extracted as transient mechanical features. The health deviation index is calculated in conjunction with preset standard parameters. When the index does not reach the alarm threshold, a compensation coefficient is generated to update the control parameters of the next action cycle and physical wear iterative compensation is performed. Attached Figure Description

[0020] Figure 1 This is the main flowchart of the electromagnetic relay control method based on a programmable controller according to the present invention;

[0021] Figure 2 This is a schematic diagram of the two-layer decoupling control system based on time-sensitive networks of the present invention;

[0022] Figure 3 This is a schematic diagram illustrating the dynamic baseline impedance extraction and orthogonal demodulation principle of the present invention;

[0023] Figure 4 This is a schematic diagram of the calculation logic for eliminating the induced electromotive force of spatial magnetic coupling in this invention.

[0024] Figure 5 This is a schematic diagram of the relay operation and contact soft landing control of the present invention;

[0025] Figure 6 This is a flowchart illustrating the adaptive update process for health status assessment and control parameters in this invention. Detailed Implementation

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Please see the appendix Figure 1 To be continued Figure 6 This invention provides an electromagnetic relay control method based on a programmable logic controller (PLC). This method is executed under a two-layer decoupled control architecture based on a time-sensitive network (TSN) to solve the technical problems of complex electromagnetic crosstalk and wear of relay mechanical contacts in industrial control environments.

[0028] As shown in the architecture diagram, the programmable logic controller (PLC) acts as the main controller, issuing action commands and parameter matrices containing control parameters. The underlying edge input / output (EI / O) modules connect the target relay coil to the coils of adjacent relays. After receiving the action command, the EI / O modules operate independently of the PLC's main scan cycle, performing high-frequency sampling and waveform reconstruction within a local timing cycle independent of the main scan cycle. A time-sensitive network (TSN) provides an absolute clock synchronization link between the main controller and the EI / O modules, ensuring constant instruction network transmission delay and guaranteeing that the EI / O modules accurately trigger their local control logic at the specified absolute timestamp.

[0029] The edge input / output module internally houses a high-frequency analog-to-digital converter, a pulse-width modulation output unit, and a hardware coprocessor. During system operation, the main controller's operating frequency is limited by the scale of the higher-level logic; its main scan cycle is defined as... The high-frequency sampling frequency used by the edge input / output module to perform electrical feature extraction is generated by dividing the internal crystal oscillator clock, and its corresponding local timing period is defined as... The physical implementation of the dual-layer decoupling mechanism relies on the IEEE 802.1AS generalized precise clock synchronization protocol for time-sensitive networks. The main controller and edge input / output modules maintain nanosecond-level clock synchronization. Simultaneously, the IEEE 802.1Qbv time-aware shaper allocates dedicated time slots for transmitting action commands, isolating the host computer from non-deterministic network jitter. The edge input / output modules operate autonomously without main controller intervention, maintaining strict... The electromagnetic field characteristic calculation and braking pulse output are performed with a step size, and are not affected by the step size. The impact of fluctuations.

[0030] The control parameter matrix issued by the main controller is defined as follows: This matrix includes, but is not limited to, time integral compensation coefficients, critical position thresholds, and feedback gain coefficients for closed-loop regulation. Parameter matrix The parameter matrix is ​​generated based on historical test bench statistics and relay factory calibration parameters, and pre-cached in the local random access memory of the edge input / output module. The edge input / output module continuously reads the parameter matrix during operation. The system switches its working state based on the physical processes of the system.

[0031] The electromagnetic relay control method based on a programmable logic controller (PLC) for industrial control systems may include the following steps:

[0032] Step S1: In the non-driving state, extract the dynamic baseline impedance of the target relay coil in real time;

[0033] Step S2: When the action command is received, the transient supply voltage and transient current of the target relay coil are collected, and the true back electromotive force after removing the spatial magnetic coupling induced electromotive force is calculated by combining the dynamic baseline impedance and the spatial magnetic coupling induced electromotive force generated by the coils of adjacent relays.

[0034] Step S3: Map the real back electromotive force to the real-time motion state of the armature of the target relay, and when the position parameter in the real-time motion state reaches the preset critical position threshold, apply a reverse braking voltage pulse to the target relay coil based on the preset control parameters to achieve soft landing of the contacts;

[0035] Step S4: After the mechanical action corresponding to the action command is completed, extract transient mechanical features to assess the health status and adaptively update the control parameters.

[0036] The above control steps rigorously divide the operational lifecycle of the electromagnetic relay into a non-drive standby stage, a transient action stage, and a steady-state analysis stage. Before the main controller issues an action command, the relay is in a non-drive state, and the edge input / output module executes background detection logic. The dynamic baseline impedance in step S1 reflects the real-time impact of the current ambient temperature and the residual magnetism of the iron core on the coil's electrical characteristics, providing a basic physical zero-point calibration basis for subsequent back electromotive force calculation.

[0037] When the control parameter matrix When the accompanying action command is sent to the edge input / output module via the time-sensitive network, the edge input / output module immediately cuts off the background detection task and enters the high-frequency sampling and real-time calculation stage. In step S2, the system simultaneously monitors the operating status of the target relay and adjacent relays. For industrial control backplanes with high-density distribution, the current surge of adjacent coils causes an additional change in magnetic flux induced in the target relay coil. Based on the electrical data acquired through synchronous sampling, the system performs differential algebraic operations to eliminate interference components from spatial magnetic coupling effects and extract the true electrical quantities that only reflect the displacement of the target relay armature.

[0038] After obtaining the electrical quantities after crosstalk removal, step S3 uses these parameters to calculate the mechanical displacement characteristics. The hardware coprocessor performs parallel multiply-accumulate operations to convert the electrical characteristics into kinematic characteristics and tracks the spatial coordinates of the armature on the time axis. Once the calculated value crosses the set safety boundary, the pulse width modulation unit of the edge input / output module immediately flips the output polarity, generating instantaneous electromagnetic resistance opposite to the direction of the magnetic flux attraction, consuming the remaining kinetic energy of the armature, and causing the moving and stationary contacts to close at an extremely low speed.

[0039] After a stable connection is established at the physical contacts, step S4 proceeds to the post-processing flow. The system reviews the electrical waveform sample set throughout the entire operation to identify characteristic inflection points reflecting the mechanical health status. Based on the degree of deviation of the current control, the system uses an adaptive iterative algorithm to adjust the parameter matrix. The internal control parameters are corrected, overwriting the old parameters in the original memory, thereby completing the control loop and providing an optimized basis for the next action command issued by the main controller.

[0040] In this embodiment, when the system is in a non-driven state, the main controller does not issue any action commands, and the armature of the target relay remains in its initial stationary air gap position. The edge input / output module continuously or periodically injects orthogonal high-frequency probe carrier voltage into the target relay coil. The system's internal digitally controlled oscillator generates a sine and cosine sequence with a 90-degree phase difference, and the digital-to-analog converter circuit combines these sequences to output the probe voltage signal of the physical entity. The time-domain expression of the orthogonal high-frequency probe carrier voltage is defined as follows: ,in Indicates the amplitude of the carrier voltage. Represents a time variable. This indicates the preset carrier angular frequency. The system sets the carrier angular frequency. carrier frequency The value range was selected as 10kHz to 50kHz. This frequency band is much higher than the inherent response frequency of the relay's mechanical structure, ensuring that the alternating magnetic field will not induce mechanical resonance in the armature.

[0041] In this invention, the main controller pre-determines the minimum sustaining voltage of the target relay based on historical test bench statistics and factory static calibration parameters. and the equivalent capacitance of the coil The system calculates the critical starting energy threshold that triggers the mechanical action of the armature, and its energy equation is defined as follows: The edge input / output module adjusts the carrier voltage amplitude before the output signal. This limits the carrier energy duty cycle within a single cycle to the critical start-up energy threshold. The amplitude is between 15% and 30%. The transient electromagnetic attraction generated inside the target relay coil by the low-amplitude high-frequency alternating electromagnetic field is insufficient to overcome the initial mechanical reaction force of the restoring spring, and the armature remains absolutely stationary throughout the entire detection cycle. The target relay coil generates a steady-state response to the quadrature high-frequency detection carrier voltage, and the high-frequency analog-to-digital converter inside the edge input / output module synchronously samples the steady-state response current of the target relay coil to the quadrature high-frequency detection carrier voltage.

[0042] The steady-state response current time-domain expression obtained by the edge input / output module is defined as follows: In the formula, This represents the magnitude of the steady-state response current. This represents the phase difference between the current phasor and the voltage phasor. A high-frequency analog-to-digital converter (ADC) converts the simulated steady-state response current into a discrete-time sequence using a local timing period, which is then transmitted to a hardware coprocessor for analytical calculation. The hardware coprocessor uses a digital quadrature demodulation algorithm to perform the calculation: first, it converts the steady-state response current... The discrete sequences are discretely multiplied with the unit sine and unit cosine sequences synchronously output by the digitally controlled oscillator. The product results are then input into a preset digital low-pass filter, specifically a fourth-order Butterworth infinite-impulse response (IIR) low-pass filter with a cutoff frequency set at 500Hz. This filter removes high-frequency components of the harmonics and separates the in-phase and quadrature components of the DC state. The hardware coprocessor calculates the complex impedance magnitude and phase difference based on these components.

[0043] When the system performs specific algebraic operations, the magnitude of the complex impedance is defined as... Phase difference The value is obtained by combining the arctangent function with the ratio of the in-phase component to the quadrature component. When the target relay coil is in the non-driving state, its electromagnetic model is equivalent to a series circuit of a resistor and inductor with lumped parameters. Real-time fluctuations in ambient temperature cause thermodynamic drift in the resistance of the copper wire winding, while the microscopic remanent magnetization state inside the iron core alters the initial permeability; this causes the complex impedance modulus to... It exhibits nonlinear time-varying characteristics. The system utilizes a hardware coprocessor to further calculate the dynamic DC resistance and static inductance to characterize the dynamic baseline impedance and eliminate physical interference caused by the aforementioned environmental factors.

[0044] The edge input / output module decomposes the complex impedance magnitude based on the fundamental phasor theory of AC circuits. The formula for calculating dynamic DC resistance is as follows: The formula for calculating static inductance is: In the above formula, This represents the dynamic DC resistance that drifts in real time with ambient temperature and its own Joule heat. This represents the static inductance when the armature is in its initial static air gap position and is affected by the remanent magnetization of the iron core. The system will calculate the dynamic DC resistance. With static inductance The data is stored in local random access memory and continuously overwritten and updated periodically to form the latest dynamic baseline impedance parameter characterization set, providing a zero-point reference for extracting the true back electromotive force without time drift error in subsequent action phases.

[0045] In this embodiment, the main controller issues an action command through a time-sensitive network. The edge input / output module receives the command and triggers a high-frequency sampling program with a local timing cycle. The internal analog-to-digital converter synchronously acquires the transient supply voltage and transient current of the target relay coil. The system defines the time-domain symbol of the transient supply voltage as... The time-domain symbol for transient current is defined as... ,in This represents a time variable. The system uses a first-order backward difference algorithm to analyze the transient current. The discrete sampling points are subjected to time differentiation, which subtracts the current value of the previous period from the current value of the current sampling period and divides by the local timing period. Obtain the transient current change rate of the target relay. .

[0046] In this invention, to address the magnetic flux intermodulation phenomenon caused by the arrangement of multiple relay arrays on an industrial control backplane, the edge input / output module synchronously acquires the transient current of the coils of adjacent relays. The hardware system defines the adjacent range based on physical distance, identifying relays that share the same common ground reference plane with the target relay and whose physical Euclidean distance is within a radius of five centimeters as adjacent relays. The system sets the industrial control backplane to include the aforementioned defined range. The adjacent relays that are affected by electromagnetic crosstalk will... The rate of change of transient current of adjacent relays is defined as ,in The integer value range is from 1 to Incremental. The system retrieves the spatial mutual inductance coefficient between the target relay and adjacent relays. This spatial mutual inductance coefficient is a pre-determined numerical constant calculated using finite element electromagnetic simulation software by inputting circuit board stack-up parameters, coil physical spacing, and trace coordinates, and then simulating magnetic field coupling strength. It is statically stored in the edge input / output module.

[0047] The hardware coprocessor uses the extracted spatial mutual inductance coefficients to construct a spatial magnetic coupling crosstalk suppression matrix. The system expresses the row vectors of this matrix as follows: ; matrix elements Represents the target relay coil and the first The pre-calibrated spatial mutual inductance coefficients of adjacent relay coils. The hardware coprocessor uses the spatial magnetic coupling crosstalk suppression matrix. with by rate of change of transient current The column vectors formed are multiplied algebraically to calculate the spatial magnetic coupling induced electromotive force generated by the coils of adjacent relays.

[0048] The system defines the spatial magnetic coupling induced electromotive force generated by the coils of adjacent relays as a symbol. The algebraic summation equation for this parameter is expressed as follows: Simultaneously, the system reads the dynamic DC resistance stored in the local random access memory during the non-drive phase. With static inductance The edge input / output module, combining the aforementioned dynamic baseline impedance with transient current and transient current rate of change, calculates the voltage drop across the dynamic baseline impedance caused by the transient current. The sign of this voltage drop is set as... Its circuit model calculation equation is: .

[0049] The system performs differential operations on Kirchhoff's voltage loop equations to remove interference. The hardware processing unit utilizes transient supply voltages. Subtract the voltage drop across the dynamic baseline impedance caused by the transient current. And subtract the space magnetic coupling induced electromotive force calculated by the space magnetic coupling crosstalk suppression matrix and the transient current change rate. The hardware coprocessor outputs the final result based on the above subtraction logic, deriving the true back electromotive force after removing the spatial magnetic coupling induced electromotive force. The system defines the sign of the true back electromotive force as... Its comprehensive physical equations are presented as The true back electromotive force output by this equation. This eliminates waveform distortion caused by DC bias and coupling with adjacent magnetic fields due to temperature drift, providing a decoupled data source for time integration of motion states.

[0050] In this embodiment, after the edge input / output module obtains the true back electromotive force, the system retrieves a pre-calibrated position-associated electromagnetic coefficient. This position-associated electromagnetic coefficient... Defined as the rate of change of the magnetic flux with respect to the air gap displacement, i.e. During the manufacturing process, the system obtains the linearization constant by dividing the rated magnetic flux by the total mechanical stroke length of the armature and stores it in local random access memory. The hardware coprocessor performs the division operation and correlates the position with the electromagnetic coefficient. The system maps the real back electromotive force to the real-time velocity of the armature. The sign of the real-time velocity is defined as... The mapping calculation formula is expressed as follows: .

[0051] The system acquires real-time motion speed Then, combined with the initial static air gap Extracting the real-time air gap position. The system employs a trapezoidal numerical integration algorithm to extract the real-time motion velocity along the discrete time axis. The area under the curve is accumulated. The system defines the sign of the real-time air gap position as... The position solution equation is expressed as follows ,in These are time integral compensation coefficients extracted from the parameter matrix, used to correct clock drift. This is the integration time variable. Simultaneously, the hardware coprocessor employs a first-order backward difference algorithm to calculate the real-time motion velocity. The system performs time derivative calculations to obtain real-time motion acceleration. The sign of the real-time motion acceleration is defined as... The formula for differentiation is expressed as follows: .

[0052] In this invention, the logic control unit inside the edge input / output module continuously monitors and calculates the real-time air gap position. The system obtains control parameter matrices. The system reads a preset critical position threshold and defines the sign of this critical position threshold as... The critical position threshold The initial value is set to the initial static air gap. 5% to 10% represents the high-risk zone boundary before a physical collision occurs between the moving and stationary contacts. The logic judgment circuit executes numerical comparison instructions at a local timing cycle, determining the real-time air gap position. Less than or equal to the preset critical position threshold At this time, the edge input / output module sends a shutdown command to the internal pulse width modulation unit, which immediately cuts off the positive drive voltage. The armature continues to move towards the stationary contact using its existing kinetic energy, and the system synchronously enters the active braking process.

[0053] After the pulse width modulation unit cuts off the positive drive voltage, the system adjusts according to the real-time motion speed. Real-time motion acceleration The system calculates and outputs the reverse braking voltage pulse based on the feedback gain coefficient, which serves as a control parameter. The proportional feedback gain coefficient and the derivative feedback gain coefficient are extracted and used as the control parameters mentioned above. The system defines the proportional feedback gain coefficient as... The differential feedback gain coefficient is defined as The two coefficients mentioned above are pre-calculated using the Ziegler-Nichols empirical tuning method during system initialization to ensure that the braking process exhibits a critical damping state without overshoot. The system defines the sign of the reverse braking voltage pulse as... The hardware coprocessor operates based on the control law equation. Calculate the target pulse amplitude.

[0054] Edge input / output module based on reverse braking voltage pulse The calculation results control the underlying hardware to drive the bridge arm to flip the output polarity. The pulse width modulation unit, based on... The absolute value is dynamically adjusted in real time to regulate the output duty cycle and inject a reverse excitation current into the target relay coil. This reverse excitation current generates a reverse electromagnetic braking torque in the magnetic circuit, opposite to the direction of armature movement. This reverse electromagnetic braking torque acts directly on the armature, producing negative work to reduce the armature's kinetic energy. When the high-frequency analog-to-digital converter detects a transient current spike indicating a contact closure collision, the specific judgment criteria are: the rate of change of current for three consecutive high-frequency sampling cycles is greater than the preset 20A / s jump threshold, or the calculated real-time movement speed... When the speed drops to a near-zero stop threshold (specifically set to 0.05 m / s), the pulse width modulation unit terminates the reverse pulse output. This process precisely reduces the speed of the armature end movement, and the collision energy when the moving contact reaches the mechanical closed position approaches zero, achieving a soft landing of the physical contact.

[0055] In addition to the process of the main controller issuing the engagement command, when the main controller issues the release command, the edge input / output module cuts off the coil sustaining voltage according to the same two-layer decoupling logic. The restoring spring releases mechanical potential energy to drive the armature to retract in the opposite direction, and the hardware coprocessor also calculates the true back electromotive force during the demagnetization stage according to the equation. This is then mapped to retraction speed and position. When the air gap position of the reverse retraction is detected to reach the preset reverse release threshold, which is specifically defined as 5% to 10% of the total mechanical air gap stroke in the initial fully released state, and is directly provided by the parameter matrix, the pulse width modulation unit injects a brief positive compensation voltage pulse into the coil. The target amplitude of the positive compensation voltage pulse is... Based on the release closed-loop control law equation Real-time calculation, in which and These represent the reverse retraction velocity and retraction acceleration of the armature, respectively. The proportional release gain in the equation... With differential release gain The damping factor is pre-set by the system during the factory calibration stage using the critical damping formula, based on the stiffness coefficient of the recovery spring and the mass of the armature. The pulse width modulation unit is based on the target amplitude. The duty cycle of the positive compensation pulse is dynamically adjusted to generate a weak positive electromagnetic attraction to counteract the impact kinetic energy at the end of the restoring spring. When the transient current during the demagnetization phase finally returns to zero, or the calculated reverse retraction speed... When the voltage drops to the preset zero-point stop threshold, the pulse width modulation unit terminates the positive compensation voltage pulse output. Through the above-mentioned bidirectional symmetrical closed-loop control strategy, the system fully covers the entire life cycle of the relay's engagement and disengagement, and bidirectionally eliminates the contact bounce phenomenon caused by mechanical collisions.

[0056] In this embodiment, the local random access memory of the edge input / output module completely records all electrical and kinematic discrete data during a single mechanical action. The system reads the recorded transient process data corresponding to the mechanical action and uses an internal high-frequency timer to extract the real-time motion speed from the moment the action command is received. The time difference between the first occurrence of the second zero crossing is used as the pull-in delay time. Simultaneously, the system extracts the true back electromotive force. The residual oscillation waveform after dropping to zero is obtained by acquiring the peak amplitude of two adjacent oscillation cycles and performing a natural logarithmic ratio calculation to obtain the kinetic energy damping attenuation coefficient.

[0057] In this invention, the system uses the pull-in delay time and the kinetic energy damping attenuation coefficient as transient mechanical characteristics characterizing the current closed state of the mechanical contacts. The system sets the sign of the pull-in delay time as... The sign of the kinetic energy damping attenuation coefficient is set as... The system retrieves the preset standard delay time and standard attenuation coefficient from local random access memory. The main controller presets these standard parameters based on the statistical average value of life cycle test benches for the same type of relay and sends them out along with the initial parameter matrix. The system sets the symbol for the standard delay time to be... The sign of the standard attenuation coefficient is set as The hardware coprocessor inside the edge input / output module compares the extracted transient mechanical features with the aforementioned standard parameters using absolute deviation.

[0058] During the comparison operation, the system simultaneously introduces normalized weighting coefficients to balance the difference in data magnitude between the time dimension and the energy decay dimension. The system defines the normalized weighting coefficients for the time feature as follows: The normalized weighting coefficients for the decay characteristics are defined as follows: Based on the analysis of the main failure modes of relays, contact wear has a greater impact on time characteristics, and the system is set with the following weighting conditions: And pre-configure specific values ​​as , The hardware coprocessor calculates the health deviation index using normalized weighting coefficients. The system defines the sign of the health deviation index as... Its mathematical evaluation model is constructed as follows This index visually quantifies the degree of mechanical performance degradation caused by fatigue of the relay's recovery spring and wear of the contact surface.

[0059] The edge input / output module continuously monitors the health deviation index calculated after each action. This data is then compared to a pre-set safety alarm threshold. This safety alarm threshold is defined based on factory fatigue test data, and its symbol is defined as follows: When the logic judgment circuit detects the health deviation index Less than the safety alarm threshold At this time, the system extracts preset static compensation parameters as proportional compensation coefficients and differential compensation coefficients to prevent parameter divergence caused by a single disturbance. The system defines the proportional compensation coefficient as follows: The differential compensation coefficient is defined as follows: The specific values ​​of the aforementioned compensation coefficients are set between 0.01 and 0.05 to control the iteration step size. The system uses multiply-accumulate operations to update the feedback gain coefficient for the next action cycle. The update equation is expressed as: New Generation Proportional Feedback Gain Coefficient New generation differential feedback gain coefficient The edge input / output module utilizes the updated... and Coverage control parameter matrix The system uses the original parameters and the health deviation index. Extract the lookup table correction value (the system has a pre-built one-dimensional mapping lookup table that divides the health deviation index range of 0 to 0.8 into 16 sub-intervals, with each sub-interval incrementally mapped to a set of coefficient fine-tuning amounts with a step size of 0.01%), and synchronously fine-tune the time integral compensation coefficient. With critical position threshold It also covers the original matrix parameters, thus completely offsetting the closed-loop control error caused by mechanical aging.

[0060] When the logic judgment circuit identifies the health deviation index Greater than or equal to the safety alarm threshold When this occurs, it indicates that the internal mechanical structure of the target relay is at risk of failure. This safety alarm threshold... Based on the factory-defined extreme fatigue test data, the specific value is set to 0.8, meaning a warning is triggered when the mechanical condition deviates from the ideal baseline by 80%. Under such severe degradation, simply relying on adaptive updates to the feedback gain coefficient is insufficient to guarantee a soft landing effect for the contacts. The communication control unit of the edge input / output module immediately generates a data set including the device media access control address, the specific port index, and the current health deviation index. The warning signal data frame is received. The edge input / output module uses a time-sensitive network to precisely push this warning signal data frame to the host computer. After receiving the warning signal, the main controller generates a maintenance work order on the human-machine interface, guiding field engineers to perform predictive maintenance on specific port nodes to avoid unexpected downtime of the industrial control system.

[0061] In this embodiment, the control system includes a memory, a processor, and a computer program stored within the memory. The system internally includes an address bus and a data bus, through which the processor establishes a physical communication link with the memory. The processor has an instruction decoding unit and a hardware coprocessor for performing complex matrix and floating-point operations. The control system utilizes an external network communication interface to establish a data synchronization link with a time-sensitive network to receive upper-level control commands; the control system also uses an external analog-to-digital converter channel to read the analog electrical parameters of the target relay coil and the coils of adjacent relays.

[0062] In this invention, the memory is composed of a read-only flash memory chip and a local random access memory. The read-only flash memory chip contains the basic instruction set of the computer program and the location-associated electromagnetic coefficients pre-calibrated at the factory. Standard delay time Compared with standard attenuation coefficient During system power-on operation, the local random access memory caches the parameter matrix containing control parameters issued by the main controller. The local random access memory synchronously records the transient currents generated during each local timing cycle. Transient supply voltage And the real-time motion velocity generated by real-time integration and differentiation. With real-time air gap position .

[0063] As the core of hardware computation, the processor fetches and executes computer programs from memory according to instruction cycles during runtime. When executing these programs, the processor first controls the analog-to-digital converter channel to inject quadrature high-frequency probe carrier voltage into the coil. And sample steady-state response current The transient parameters of the dynamic baseline impedance are calculated using a phasor separation algorithm. After receiving the action command at the network communication interface, the processor's hardware coprocessor retrieves the spatial magnetic coupling crosstalk suppression matrix. Matrix multiplication and addition are performed with the transient current rate of change vectors of each channel to remove the spatial magnetic coupling induced electromotive force from the electrical quantities at the power supply end. The true back electromotive force is calculated and extracted from the baseline voltage drop. .

[0064] Processor obtains true back EMF Then, the hardware coprocessor performs time integration and differentiation calculations in the register space, outputting real-time motion state characteristics. The internal logic gates of the processor determine the real-time air gap position. With critical position threshold The level comparison result triggers a hardware interrupt service. This hardware interrupt service forces the pulse width modulation unit to toggle its drive polarity and outputs a reverse braking voltage pulse. Upon reaching the bottom power bridge arm, the drive armature decelerates and engages to achieve a soft landing of the contact point. After the mechanical action is completed, the processor reads the transient data characteristics recorded in memory and executes the health deviation index. The algebraic solution is used to generate corresponding parameter update values ​​based on the algebraic solution result, and the parameter matrix in the local random access memory is rewritten. The feedback gain coefficient, or the writing of early warning data frames to the network communication interface, can realize a predictive control closed loop based on physical device carrier.

Claims

1. A method for controlling an electromagnetic relay based on a programmable logic controller (PLC), characterized in that: Includes the following steps: In the non-driving state, the dynamic baseline impedance of the target relay coil is extracted in real time; When an action command is received, the transient supply voltage and transient current of the target relay coil are collected, and the true back electromotive force after removing the spatial magnetic coupling induced electromotive force is calculated by combining the dynamic baseline impedance with the spatial magnetic coupling induced electromotive force generated by the coils of adjacent relays. The real back electromotive force is mapped to the real-time motion state of the armature of the target relay. When the position parameter in the real-time motion state reaches the preset critical position threshold, a reverse braking voltage pulse is applied to the coil of the target relay based on the preset control parameters to achieve soft landing of the contact. After the mechanical action corresponding to the action command is completed, transient mechanical features are extracted to assess the health status, and the control parameters are adaptively updated.

2. The electromagnetic relay control method based on a programmable controller according to claim 1, characterized in that, The method is executed under a two-layer decoupled control architecture based on time-sensitive networks, and the specific process includes: The programmable controller, acting as the main controller, issues the action commands and a parameter matrix containing the control parameters. After receiving the action command, the underlying edge input / output module breaks away from the main scan cycle of the programmable controller and independently performs high-frequency sampling and waveform reconstruction within a local timing cycle independent of the main scan cycle.

3. The electromagnetic relay control method based on a programmable controller according to claim 1, characterized in that, The real-time extraction of the dynamic baseline impedance of the target relay coil in the non-driven state includes: A quadrature high-frequency probe carrier voltage is continuously or periodically injected into the target relay coil, wherein the amplitude of the quadrature high-frequency probe carrier voltage is lower than the critical starting energy threshold that triggers the mechanical action of the armature; The steady-state response current of the target relay coil to the orthogonal high-frequency detection carrier voltage is sampled synchronously.

4. The electromagnetic relay control method based on a programmable controller according to claim 3, characterized in that, By combining the orthogonal high-frequency probe carrier voltage and the steady-state response current, the complex impedance magnitude and phase difference are calculated; and the dynamic DC resistance and static inductance are further calculated to characterize the dynamic baseline impedance.

5. The electromagnetic relay control method based on a programmable controller according to claim 1, characterized in that, The calculation yields the true back electromotive force after removing the spatial magnetic coupling induced electromotive force, including: The transient current change rate of the coils of the adjacent relays is collected synchronously; A spatial magnetic coupling crosstalk suppression matrix is ​​constructed based on the spatial mutual inductance coefficient between the target relay and the adjacent relays; The true back electromotive force is obtained by subtracting the voltage drop generated by the transient current on the dynamic baseline impedance from the transient supply voltage, and by subtracting the spatial magnetic coupling induced electromotive force generated by the coils of adjacent relays, which is calculated by the spatial magnetic coupling crosstalk suppression matrix and the transient current change rate.

6. The electromagnetic relay control method based on a programmable controller according to claim 1, characterized in that, The process of mapping the real back electromotive force to the real-time motion state of the armature of the target relay includes: By using pre-calibrated position-associated electromagnetic coefficients, the actual back electromotive force is mapped to the real-time movement speed of the armature; By combining the initial static air gap with the time integral value of the real-time motion velocity, the real-time air gap position of the armature is obtained as the position parameter, and the real-time motion acceleration is obtained by time differentiation of the real-time motion velocity.

7. The electromagnetic relay control method based on a programmable controller according to claim 6, characterized in that, Applying a reverse braking voltage pulse to the target relay coil to achieve soft landing of the contacts includes: The real-time air gap position is continuously monitored, and when the real-time air gap position is less than or equal to the preset critical position threshold, the positive drive voltage is immediately cut off. Based on the real-time motion speed, the real-time motion acceleration, and the feedback gain coefficient as the control parameter, the reverse braking voltage pulse is calculated and output to generate a reverse electromagnetic braking torque to reduce the kinetic energy of the armature.

8. The electromagnetic relay control method based on a programmable controller according to claim 7, characterized in that, The extraction of transient mechanical features to assess health status includes: From the recorded transient process corresponding to the mechanical action, the pull-in delay time and kinetic energy damping attenuation coefficient are extracted as the transient mechanical characteristics; The transient mechanical characteristics are compared with the preset standard delay time and standard attenuation coefficient, and combined with the normalized weighting coefficient, the health deviation index is calculated.

9. The electromagnetic relay control method based on a programmable controller according to claim 8, characterized in that, The adaptive update of the control parameters includes: When the health deviation index is less than the safety alarm threshold, a compensation coefficient is generated to update the feedback gain coefficient for the next action cycle; When the health deviation index is greater than or equal to the safety alarm threshold, a warning signal and a specific port index are pushed to the host computer for predictive maintenance.

10. An electromagnetic relay control system based on a programmable logic controller, characterized in that, include: The memory, the processor, and the computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, it implements the steps of the electromagnetic relay control method based on a programmable controller as described in any one of claims 1 to 9.

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