Record player design optimization method and system based on circuit design simulation

Abstract

The invention relates to the cross technical field of computer-aided engineering and audio equipment design, discloses a circuit design simulation-based disc player design optimization method and system, and aims to solve the problem that the existing disc player design depends on physical prototype trial-manufacture and subjective listening evaluation and lacks multi-physical domain co-simulation capability. The method comprises the following steps: constructing a unified multi-physical domain model comprising a mechanical transducer, an electromechanical transducer and an electronic circuit sub-model; bidirectional coupling co-simulation based on the time sequence is executed, and an output electric signal is generated; extracting objective audio performance indexes such as total harmonic distortion and signal-to-noise ratio; and carrying out multi-objective optimization on the key design parameters by utilizing a genetic algorithm, and outputting a Pareto optimal scheme. The system comprises a model construction module, a co-simulation module, a performance index extraction module and an optimization module. Through high-fidelity full-link simulation and automatic optimization, the design efficiency and the audio fidelity are remarkably improved, and the research and development cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of computer aided engineering (CAE) and audio equipment design, and particularly relates to a record player design optimization method and system based on circuit design simulation. BACKGROUND

[0002] With the resurgence of vinyl records in the field of high-fidelity audio, the record player, as the core device for analog audio playback, its sound quality performance is closely related to the precision of circuit design. The traditional record player design mainly relies on experience-driven hardware debugging and trial-and-error circuit building, and the key circuit modules such as preamplifier, RIAA equalization and power filter usually adopt fixed topology structure and nominal parameters. However, vinyl signals have the characteristics of extremely low level, wide dynamic range and high sensitivity to noise, and are easily disturbed by factors such as circuit parasitic parameters, component tolerances, temperature drift and mechanical vibration coupling in the actual playing process. The fixed circuit scheme is difficult to dynamically adapt to different cartridge output impedance, wire distribution capacitance and environmental electromagnetic noise, resulting in a decrease in signal-to-noise ratio, phase distortion or loss of high-frequency details, which seriously affects the accuracy of audio restoration and the immersion of listening experience.

[0003] Among them, the record player optimization method based on circuit simulation aims to predict and correct the circuit performance in advance through virtual modeling. This method usually uses simulation tools such as SPICE to analyze the frequency response, distortion and stability of the preamplifier circuit to guide component selection and layout. However, the existing simulation-driven design process still has significant limitations: the simulation model is usually based on ideal component parameters, and cannot effectively integrate the micro-vibration electric signal coupling effect caused by the actual record player mechanical structure, nor consider the influence of different vinyl record groove wear degrees on signal spectrum distribution; at the same time, there is a lack of closed-loop feedback mechanism between simulation and actual measurement, which cannot dynamically adjust the circuit parameter configuration according to the real listening environment or user subjective sound quality preference.

[0004] In the prior art, on the one hand, there is a problem of excessive reliance on general audio amplifier circuit templates and neglect of the specificity of vinyl signals, resulting in deviation of the RIAA equalization curve from the standard, low-frequency response delay or high-frequency overshoot; on the other hand, the simulation optimization process is mostly static single-point evaluation, lacking systematic verification of the robustness of the circuit under multiple working conditions (such as different cartridge types, cable lengths, grounding methods). In addition, in the field of high-precision audio equipment, users' personalized needs for tone style (such as warmth, resolution, and sound field width) are increasing, and traditional design methods cannot achieve explainable and quantifiable sound quality regulation at the circuit level. Therefore, there is an urgent need for a record player design optimization method and system that deeply integrates circuit simulation, multi-physical field coupling modeling and user perception feedback, to realize the technical leap from being able to play to accurately restoring and even individual interpretation. SUMMARY

[0005] The technical problem to be solved by the present application is that the existing record player design process seriously relies on empirical physical prototype trial production and subjective listening evaluation, lacks accurate modeling and system-level collaborative simulation capabilities for complex dynamic coupling relationships between mechanical vibration, electromechanical transduction, electronic signal processing and other multiple physical domains in the record player system, resulting in long design cycle, high research and development cost, and difficulty in finding the globally optimal design parameter combination through a systematic method, thereby limiting the further improvement of the record player audio fidelity.

[0006] To solve the above technical problems, the present application provides a record player design optimization method and system based on circuit design simulation, which realizes accurate simulation of the dynamic behavior of the full-link from picking up the groove vibration signal of the vinyl record by the stylus to the final audio electrical signal output by constructing a unified multi-physical domain simulation model including mechanical structure, electromechanical transducer and electronic circuit; at the same time, through establishing a bidirectional coupled collaborative simulation execution mechanism, the interaction between different physical domain models is solved in real time, and based on the audio performance indicators output by the simulation, a multi-objective optimization algorithm is used to automatically optimize the key design parameters of the record player, so that the optimal design scheme is obtained in the design stage.

[0007] In one aspect, the present application provides a record player design optimization method based on circuit design simulation, which comprises the following steps: S1, a unified multi-physical domain model of the record player is constructed, which comprises interrelated mechanical sub-model, electromechanical transducer sub-model and electronic circuit sub-model; The mechanical sub-model is used to represent the dynamic mechanical properties of the record player turntable, bearing, tone arm and counterweight assembly; the electromechanical transducer sub-model is used to represent the physical process of converting the stylus vibration to displacement electrical signal inside the cartridge; and the electronic circuit sub-model is used to represent the electrical properties of the cartridge amplifier and motor drive circuit.

[0008] S2, time series-based collaborative simulation is performed, in which a central master algorithm schedules the synchronous iteration calculation of each sub-model within a preset simulation time length, and at each time step, a bidirectional data coupling interface is used to exchange the state variables between each sub-model, so as to solve the dynamic response of the whole system under external excitation and generate the original output electrical signal sequence; the external excitation is a standard test signal representing the groove modulation of the vinyl record.

[0009] S3, audio performance indicators are extracted and quantified, the original output electrical signal sequence generated by the collaborative simulation is signal processed and analyzed, and a set of pre-defined objective audio performance indicators are calculated, including total harmonic distortion plus noise, intermodulation distortion, signal-to-noise ratio, left-right channel separation and wow and flutter rate.

[0010] S4, performing multi-objective design parameter optimization, taking the quantified audio performance indicators as an optimization objective function, taking the key design parameters of the record player as optimization variables, and performing iterative optimization in a preset design parameter space by using a genetic algorithm; in each iteration, the unified multi-physical domain model is reconstructed by using the updated design parameters, and the steps of co-simulation and performance indicator extraction are repeatedly performed until the objective function converges or a preset number of iterations is reached, and finally a set of Pareto optimal design parameter combinations is output.

[0011] Preferably, the mechanical sub-model in the record player unified multi-physical domain model is constructed, specifically by establishing a finite element method: First, according to the geometric structure, material properties and assembly relationship of the record player turntable, bearing, tone arm and counterweight assembly, a three-dimensional solid model is generated and spatial grid is divided; Then, boundary conditions and constraints are applied to the grid model, including rotational constraints of the bearing, pivot constraints of the tone arm, and connection constraints with the base, thereby generating system mass matrix, stiffness matrix and damping matrix describing the structural dynamic behavior.

[0012] Preferably, the electromechanical transducer sub-model in the record player unified multi-physical domain model is constructed, specifically by a coupled magnetic circuit-mechanical vibration equation set.

[0013] For a moving magnet cartridge, the stylus, needle bar, suspension system and magnet are equivalent to a multi-degree-of-freedom mass-spring-damper system, and the vibration equation of the system is input from the force acting on the groove wall of the record; at the same time, a magnetic field model based on the magnetic resistance method of the magnetic circuit is established, which models the magnetic circuit formed by the permanent magnet, yoke, pole shoe and the magnet driven by the needle bar vibration, wherein the needle bar displacement is a variable that changes the air gap length of the magnetic circuit. By calculating the rate of change of total magnetic flux with time, the output voltage generated in the induction coil is solved according to Faraday's law of electromagnetic induction.

[0014] Preferably, the electronic circuit sub-model in the record player unified multi-physical domain model is constructed, specifically by establishing a circuit netlist.

[0015] The circuit netlist accurately describes the types, parameter values and connection topological relationships of all electronic components in the cartridge amplifier circuit, including resistors, capacitors, inductors, operational amplifiers and transistors.

[0016] For the motor drive circuit, the circuit netlist describes the circuit structure of the servo control loop for controlling the constant speed rotation of the turntable, including the speed detection unit, error amplifier and power drive stage.

[0017] Preferably, the bi-directional data coupling interface in time-series based co-simulation is implemented to realize the real-time exchange of the following data: At each simulation time step, the mechanical sub-model transmits the calculated displacement and velocity of the stylus tip in three-dimensional space to the electromechanical transducer sub-model as the boundary conditions of its cantilever vibration system; the electromechanical transducer sub-model transmits the calculated original output voltage of the induction coil to the electronic circuit sub-model as the input signal of the phono preamplifier; the electronic circuit sub-model feeds back the load current caused by the calculated input impedance of the phono preamplifier to the electromechanical transducer sub-model to correct the electromagnetic damping force of the induction coil.

[0018] Meanwhile, the motor drive circuit in the electronic circuit sub-model transmits the output driving torque to the mechanical sub-model to drive the turntable model to rotate, and the mechanical sub-model feeds back the instantaneous angular velocity of the turntable to the speed detection unit in the electronic circuit sub-model to form a closed-loop control.

[0019] Preferably, the key design parameters in the execution of multi-objective design parameter optimization include: In the mechanical sub-model, the effective length, effective mass, overhang, tube wall thickness, material type of the tonearm, and the mass and position of the counterweight; In the electromechanical transducer sub-model, the equivalent mass of the stylus, the compliance and damping coefficient of the suspension system, and the magnetic field strength of the permanent magnet; in the electronic circuit sub-model, the values of the input stage resistance and capacitance of the phono preamplifier, and the parameters of the key components in the feedback network.

[0020] Preferably, the specific process of the genetic algorithm in the execution of multi-objective design parameter optimization includes: Initialization of population, randomly generate an initial population consisting of multiple individuals within the preset design parameter value range, and each individual represents a complete set of turntable design parameters; Fitness evaluation, for each individual in the population, construct the corresponding unified multi-physics domain model according to its design parameters, perform co-simulation and calculate its audio performance indicators, and then convert multiple performance indicators into a single fitness value through weighted summation or Pareto sorting; Selection operation, according to the size of the individual fitness value, use roulette selection or tournament selection to select excellent individuals from the current population into the next generation; Cross operation, pair the selected individuals, and with a preset crossover probability, exchange part of the parameter gene fragments of the two paired individuals at a randomly selected crossover point to generate new offspring individuals; a mutation operation, which randomly changes the value of one or more parameter genes of the newly generated offspring individual with a preset mutation probability, to increase the diversity of the population; The above-mentioned fitness evaluation, selection, crossover and mutation operations are repeated until the overall fitness of the population no longer improves significantly or a preset maximum evolution generation is reached, and the design parameters corresponding to the individual with the highest fitness in the final population are output as the optimal design scheme.

[0021] In another aspect, the present application also provides a record player design optimization system based on circuit design simulation, which comprises: a unified multi-physics domain model construction module, configured to generate a unified multi-physics domain model comprising a mechanical sub-model, an electromechanical transducer sub-model and an electronic circuit sub-model according to the geometric structure, material properties and circuit topology of the record player; a collaborative simulation execution module, connected with the unified multi-physics domain model construction module, configured to iteratively solve the unified multi-physics domain model in the time domain, realize data exchange between the sub-models through a bidirectional data coupling interface, simulate the whole process of the record player from sound pickup to signal output, and output the original electrical signal sequence; an audio performance index extraction module, connected with the collaborative simulation execution module, configured to receive the original electrical signal sequence and perform frequency spectrum analysis and statistical calculation thereon to extract a series of quantified audio performance indexes such as total harmonic distortion plus noise, signal-to-noise ratio and channel separation degree; a multi-objective design optimization module, connected with the unified multi-physics domain model construction module and the audio performance index extraction module, configured to take the audio performance indexes as optimization objectives and the key design parameters of the record player as variables, automatically adjust the design parameters and drive the model construction module and the simulation execution module to perform cyclic calculation through the built-in genetic algorithm until a set of design parameter combinations that make the overall audio performance indexes optimal is found.

[0022] Preferably, the unified multi-physics domain model construction module comprises internally: a mechanical sub-model generation unit, configured to receive three-dimensional geometric data and material parameters of the mechanical components of the record player and generate a system matrix describing the structure dynamics using the finite element analysis software kernel; an electromechanical transducer sub-model generation unit, configured to receive internal structure parameters and electromagnetic parameters of the cartridge and establish a coupled differential equation set describing the relationship between the stylus vibration and voltage induction; an electronic circuit sub-model generation unit, configured to receive the circuit diagram or netlist file of the cartridge amplifier and motor driving circuit and generate a mathematical model for circuit transient analysis.

[0023] Preferably, the collaborative simulation execution module comprises internally: a master time stepper, which is preset with a fixed total simulation time length and a calculation time step, for controlling the time advancement and synchronization of the whole simulation; a finite element solver, which is used to solve the displacement, velocity and acceleration responses of the mechanical sub-model according to the external force and the state at the previous time step in each time step; a differential equation solver, which is used to solve the coupled equations of the electromechanical transducer sub-model to calculate the induced voltage; a circuit simulator, which is used to perform transient analysis on the electronic circuit sub-model to calculate the voltage and current of each node in the circuit; the bidirectional data coupling interface, which is essentially a shared memory area or an inter-process communication pipe, is used to store and forward the state variables calculated by each solver at the end of each time step.

[0024] Preferably, the multi-objective design optimization module comprises: a parameter space definition interface, which is used to allow the user to input the design parameters to be optimized and their value ranges or constraint conditions; an optimization objective function constructor, which is used to combine the multiple performance indicators output by the audio performance indicator extraction module into one or more fitness functions for genetic algorithm evaluation through preset weight coefficients or Pareto sorting rules; a genetic algorithm engine, which implements the complete algorithm logic of population initialization, fitness evaluation, selection, crossover and mutation, and is responsible for the process control and convergence judgment of the whole optimization iteration process.

[0025] In summary, the present application includes at least one of the following beneficial technical effects: 1. The present application realizes, for the first time, high-fidelity dynamic co-simulation of the whole link from mechanical vibration to electrical signal output of the record player system by constructing an integrated multi-physics model, accurately captures the complex bidirectional coupling effect between the mechanical and electrical parts, and overcomes the model distortion problem caused by isolated analysis of each part in the prior art.

[0026] 2. The present application directly extracts objective and quantifiable audio performance indicators from simulation results, replacing the subjective listening evaluation link in the traditional design process, providing a unified and repeatable scientific basis for design evaluation, and greatly improving the accuracy and efficiency of evaluation.

[0027] 3.The application introduces a multi-objective automatic optimization mechanism based on genetic algorithm, which can perform global optimization in a wide and complex design parameter space, systematically explore the optimal design scheme combination beyond the experience range of human engineers, and thus lock the optimal design in the early stage of product development, significantly shorten the development cycle, reduce the manufacturing cost and testing cost of the physical prototype, and finally realize the breakthrough improvement of the audio fidelity performance of the record player. BRIEF DESCRIPTION OF DRAWINGS

[0028] Fig. 1 is the overall technical scheme architecture schematic diagram of the application.

[0029] Fig. 2 is the core principle framework schematic diagram of the unified multi-physical domain model and the bidirectional coupling co-simulation mechanism in the application.

[0030] Fig. 3 is the logic flow framework diagram of the multi-objective design parameter optimization in the application. DETAILED DESCRIPTION

[0031] In order to further illustrate the technical means and effects adopted by the application to achieve the predetermined application purpose, the following will combine the preferred embodiments with the accompanying drawings to explain the specific embodiments of the application in detail. Figs. 1 to 3 and the preferred embodiments, the specific embodiments of the application are described in detail.

[0032] The application provides a record player design optimization method and system based on circuit design simulation, aiming to solve the technical problems of long design cycle, high research and development cost, and difficult systematic improvement of audio fidelity caused by the lack of accurate modeling capability of dynamic coupling relationship between mechanical vibration, electromechanical transducer and electronic signal processing in the existing record player design process.

[0033] The application realizes automatic global optimization of key design parameters of the record player by constructing a unified multi-physical domain model, performing time sequence co-simulation, extracting objective audio performance indicators, and combining a multi-objective optimization algorithm.

[0034] A record player design optimization method based on circuit design simulation, comprising the following steps: S1, constructing a unified multi-physical domain model of the record player; S2, performing time sequence-based co-simulation; S3, extracting and quantifying audio performance indicators; S4, performing multi-objective design parameter optimization.

[0035] In the step S1, the unified multi-physical domain model of the record player is composed of three interrelated sub-models, namely a mechanical sub-model, an electromechanical transducer sub-model and an electronic circuit sub-model.

[0036] The mechanical sub-model is used to represent the dynamic mechanical characteristics of the turntable, bearing, tone arm and counterweight assembly; the electromechanical transducer sub-model is used to represent the physical process of converting the vibration of the stylus into the displacement electrical signal inside the cartridge; the electronic circuit sub-model is used to represent the electrical characteristics of the cartridge amplifier and motor driving circuit.

[0037] The specific construction process of the mechanical sub-model is as follows: According to the geometric structure, material properties and assembly relationship of the turntable, bearing, tone arm and counterweight, a three-dimensional entity model is generated, which is then imported into the finite element analysis kernel for spatial mesh partitioning to generate a discretized grid structure composed of tetrahedral or hexahedral elements; the material properties include elastic modulus, Poisson's ratio, material density and damping coefficient, which are input as standard values or experimentally measured values in the material database.

[0038] After completing the mesh partitioning, boundary conditions and constraints are applied to the three-dimensional entity model, including the rotational freedom constraint of the bearing, the rotational constraint at the tone arm pivot, and the fixed connection constraint between the tone arm base and the cabinet.

[0039] Through the above processing, the system mass matrix, stiffness matrix and damping matrix describing the dynamic behavior of the mechanical structure are generated, which constitute the core mathematical expression of the mechanical sub-model for solving the dynamic response of the structure under external excitation in subsequent co-simulation.

[0040] The specific construction process of the electromechanical transducer sub-model is as follows: For a moving magnet cartridge, the stylus, needle stem, suspension system and magnet are equivalent to a multi-degree-of-freedom mass-spring-damper system, the vibration equation of which is based on Newton's second law, with the input being the transverse and longitudinal forces applied to the stylus tip from the groove wall of the vinyl record.

[0041] At the same time, a magnetic field model based on the magnetic resistance method of magnetic circuit is established, which models the closed magnetic circuit formed by the permanent magnet, yoke, pole shoe and magnet driven by the needle stem vibration, with the displacement of the needle stem as a variable to dynamically change the length of the air gap in the magnetic circuit. The rate of change of total magnetic flux with time is calculated by the Ohm's law of magnetic circuit, and then the output voltage generated in the induction coil is solved according to Faraday's law of electromagnetic induction.

[0042] The output voltage is the output signal of the electromechanical transducer sub-model, and its expression is: ; wherein, is the number of turns of the induction coil, The total magnetic flux of the magnetic circuit is determined by the magnetic reluctance of the magnetic circuit and the magnetic motive force of the permanent magnet, and the magnetic reluctance of the magnetic circuit varies with the displacement of the needle, thereby forming a nonlinear mapping relationship between the output voltage and the vibration displacement of the needle.

[0043] The specific construction process of the electronic circuit sub-model is as follows: The circuit netlist is established to accurately describe the types, parameter values and connection topological relationships of all electronic components in the phono preamplifier circuit, including resistors, capacitors, inductors, operational amplifiers and transistors.

[0044] For the motor drive circuit, the circuit netlist describes the servo control loop for controlling the constant rotation of the turntable, including the circuit structure of the speed detection unit, error amplifier and power drive stage. The circuit netlist is imported into the circuit simulator kernel for subsequent transient analysis calculation.

[0045] In step S2, after the construction of the unified multi-physical domain model is completed, time series-based collaborative simulation is performed. The collaborative simulation is performed within a preset simulation time, and the time step is set to the microsecond level to ensure accurate capture of high-frequency audio signals. The execution of the collaborative simulation is scheduled by a central master algorithm that synchronously calls the solvers of each sub-model at each time step and exchanges state variables between sub-models through a bidirectional data coupling interface.

[0046] The specific data exchange content of the bidirectional data coupling interface is as follows: At the end of each simulation time step, the mechanical sub-model transmits the calculated displacement and velocity of the tone arm end in three-dimensional space to the electromechanical transducer sub-model as the boundary conditions of the needle vibration system. The electromechanical transducer sub-model transmits the calculated original output voltage across the induction coil to the electronic circuit sub-model as the input signal of the phono preamplifier. The electronic circuit sub-model feeds back the load current caused by the input impedance of the phono preamplifier to the electromechanical transducer sub-model for correction of the electromagnetic damping force on the induction coil.

[0047] Meanwhile, the motor drive circuit in the electronic circuit sub-model transmits the output drive torque to the mechanical sub-model to drive the turntable model to rotate, and the mechanical sub-model feeds back the instantaneous angular velocity of the turntable to the speed detection unit in the electronic circuit sub-model to form a closed-loop control.

[0048] The external excitation of the co-simulation is a standard test signal representing the groove modulation of a vinyl record, which is a pre-defined sinusoidal sweep signal or a composite audio test signal with a frequency range from 20 Hz to 20 kHz, simulating the groove track during a real record playing process. The standard test signal is converted to a three-dimensional force vector acting on the stylus tip and is used as the initial excitation input of the mechanical sub-model.

[0049] After the co-simulation is completed, a raw output electrical signal sequence is generated, which is the voltage time series data of the cartridge amplifier output end within the simulation duration.

[0050] In step S3, the audio performance indicators are extracted and quantified, the raw output electrical signal sequence is processed and analyzed, and a set of pre-defined objective audio performance indicators are calculated, including total harmonic distortion plus noise, intermodulation distortion, signal-to-noise ratio, left-right channel separation, and wobble rate.

[0051] The calculation method of total harmonic distortion plus noise is as follows: The raw output electrical signal sequence is subjected to fast Fourier transform to obtain its frequency spectrum distribution; the fundamental frequency amplitude is extracted at the fundamental frequency, and the harmonic amplitudes are extracted at the integer multiple harmonic frequencies; the square sum of all harmonic amplitudes and the square sum of the noise floor are added and then the square root is taken, and then divided by the fundamental frequency amplitude to obtain the percentage value of the total harmonic distortion plus noise.

[0052] The calculation method of intermodulation distortion is as follows: Two sinusoidal signals with similar frequencies, such as 1900 Hz and 2000 Hz, are input to the system; the sum frequency and difference frequency components, such as 300 Hz and 3900 Hz, are detected in the output signal spectrum; the ratio of the total energy of these intermodulation products to the total energy of the original signal is calculated.

[0053] The calculation method of signal-to-noise ratio is as follows: Run the co-simulation under the condition of no input signal to obtain the root mean square value of the system noise floor; then obtain the root mean square value of the output signal under the input of the standard test signal; take the logarithmic ratio of the two, with the unit of decibel.

[0054] The calculation method of left-right channel separation is as follows: Only the left channel is input with the test signal, and the crosstalk signal amplitude of the right channel output end is measured; the amplitude ratio of the main channel signal to the crosstalk signal is calculated, and the logarithmic form is taken.

[0055] The calculation method of wobble rate is as follows: The time series of the turntable angular velocity is subjected to high-pass filtering to extract its high-frequency fluctuation component; the ratio of the standard deviation of this fluctuation component to the average angular velocity is calculated and then converted to a percentage form.

[0056] All the performance indicators mentioned above are output in numerical form as the objective function input of the subsequent optimization algorithm.

[0057] In step S4, multi-objective design parameter optimization is performed, taking the quantified audio performance indicators as the optimization objective function and the key design parameters of the record player as the optimization variables, and using a genetic algorithm to perform iterative optimization in the preset design parameter space.

[0058] The key design parameters include: In the mechanical sub-model, the effective length, effective mass, overhang, tube wall thickness, material type, and mass and position of the counterweight of the tonearm; in the electromechanical transducer sub-model, the equivalent mass of the stylus, the compliance and damping coefficient of the suspension system, and the magnetic field strength of the permanent magnet; and in the electronic circuit sub-model, the values of the input stage resistance and capacitance of the cartridge amplifier, and the parameters of the key components in the feedback network.

[0059] The specific execution process of the genetic algorithm is as follows: Initialize the population, randomly generate an initial population consisting of one hundred individuals within the preset design parameter value range. Each individual is a vector whose dimension is equal to the total number of parameters to be optimized, and each dimension corresponds to the value of a specific parameter.

[0060] Fitness evaluation, for each individual in the population, reconstruct the corresponding unified multi-physics domain model according to its design parameters, perform the complete collaborative simulation process, and calculate its corresponding audio performance indicators. Multiple performance indicators are converted into fitness values through Pareto sorting. Specifically, for each individual, calculate its dominance relationship on all targets, and non-dominated individuals obtain higher fitness. If a weighted sum method is used, normalize each indicator according to the preset weight and then sum them up.

[0061] Selection operation, using the tournament selection method, randomly select five individuals each time, and select the one with the highest fitness to enter the next generation population. Repeat this process until the number of the next generation population reaches one hundred.

[0062] Cross operation, randomly pair the selected individuals, with a pairing probability of 80%. In each pair of individuals, exchange part of the parameter gene fragments of the two individuals at a randomly selected crossover point with a crossover probability of 70% to generate two new offspring individuals.

[0063] Mutation operation, for the newly generated offspring individuals, randomly select one or more parameter dimensions with a mutation probability of 5%, and perform Gaussian perturbation on their values with a perturbation amplitude of 10% of their value range.

[0064] The above fitness evaluation, selection, crossover and mutation operations constitute a complete genetic algorithm iteration, which is repeatedly executed until the optimal fitness values of the populations of ten consecutive generations change less than a preset threshold, or a maximum evolution number of 500 generations is reached, and finally the design parameters corresponding to the individual with the highest fitness in the final population are output as the optimal design scheme.

[0065] The optimal design scheme is a set of Pareto optimal design parameter combinations, which achieves the best balance among multiple audio performance indicators.

[0066] At the system level, the present application provides a record player design optimization system based on circuit design simulation, which includes a unified multi-physics domain model construction module, a collaborative simulation execution module, an audio performance indicator extraction module and a multi-objective design optimization module.

[0067] The unified multi-physics domain model construction module is used to generate a unified multi-physics domain model containing a mechanical sub-model, an electromechanical transducer sub-model and an electronic circuit sub-model according to the geometric structure, material properties and circuit topology of the record player. The unified multi-physics domain model construction module internally includes a mechanical sub-model generation unit, an electromechanical transducer sub-model generation unit and an electronic circuit sub-model generation unit.

[0068] The mechanical sub-model generation unit receives the three-dimensional geometric data and material parameters of the mechanical components of the record player, and calls the finite element analysis software kernel to generate system mass matrix, stiffness matrix and damping matrix; the electromechanical transducer sub-model generation unit receives the internal structure parameters and electromagnetic parameters of the cartridge, and establishes a coupled differential equation system; the electronic circuit sub-model generation unit receives the circuit netlist files of the cartridge amplifier and motor drive circuit, and generates a circuit mathematical model for transient analysis.

[0069] The collaborative simulation execution module is connected with the unified multi-physics domain model construction module, and is used to iteratively solve the unified multi-physics domain model in the time domain. The collaborative simulation execution module internally includes a master time stepper, a finite element solver, a differential equation solver, a circuit simulator and a bidirectional data coupling interface.

[0070] The master time stepper controls the time advancement of the entire simulation, with a preset simulation total time of ten seconds and a time step of one microsecond; the finite element solver solves the displacement, velocity and acceleration responses of the mechanical sub-model at each time step; the differential equation solver solves the coupled equations of the electromechanical transducer sub-model using the fourth-order Runge-Kutta method; the circuit simulator performs transient analysis on the electronic circuit sub-model using the improved node analysis method; the bidirectional data coupling interface is a shared memory area that stores and forwards the state variables calculated by each solver at the end of each time step.

[0071] The audio performance index extraction module is connected with the collaborative simulation execution module, and is used for receiving the original electric signal sequence and performing spectrum analysis and statistical calculation on the original electric signal sequence.

[0072] The multi-objective design optimization module is connected with the unified multi-physical domain model construction module and the audio performance index extraction module, and is used for driving the whole optimization cycle.

[0073] The parameter space definition interface allows a user to input to-be-optimized parameters and upper and lower limits of the to-be-optimized parameters through a graphical interface; the optimization objective function constructor supports two modes of Pareto sorting and weighted summation; and the genetic algorithm engine realizes complete evolution calculation logic, and has convergence judgment and result visualization functions.

[0074] Through the collaborative work of the above method and system, the record player design is changed from experience driving to data driving, from isolated analysis to system simulation, and from subjective evaluation to objective quantification, and a new technical path is provided for the research and development of high-fidelity audio equipment.

[0075] It is apparent for those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application, and thus, the embodiments should be regarded as exemplary and non-limiting in any respect.

[0076] In addition, it should be understood that although the present specification is described in terms of embodiments, each embodiment does not include only one independent technical solution, and the description manner of the specification is only for the sake of clarity, and those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. A method for optimizing the design of a record player based on circuit design simulation, characterized in that, Comprise: S1, build a unified multi-physical domain model of a record player, including interrelated mechanical sub-models, electromechanical transducer sub-models and electronic circuit sub-models; the mechanical sub-models are used to represent the dynamic mechanical characteristics of the record player turntable, bearing, tone arm and counterweight assembly; the electromechanical transducer sub-models are used to represent the physical process of converting the vibration of the stylus into a displacement electrical signal inside the cartridge; the electronic circuit sub-models are used to represent the electrical characteristics of the cartridge amplifier and motor drive circuit; S2, perform time series-based collaborative simulation, within a preset simulation time length, a central master algorithm is used to schedule the synchronous iterative calculation of each sub-model, and at each time step, a bidirectional data coupling interface is used to exchange state variables between each sub-model, thereby solving the dynamic response of the entire system under external excitation and generating the original output electrical signal sequence; S3, extract and quantify audio performance indicators, perform signal processing and analysis on the original output electrical signal sequence generated by the collaborative simulation, and calculate a set of predefined objective audio performance indicators; S4, perform multi-objective design parameter optimization, use the quantified audio performance indicators as the optimization objective function, use the key design parameters of the record player as the optimization variables, and use the genetic algorithm to perform iterative optimization in the preset design parameter space, finally output a set of Pareto optimal design parameter combinations.

2. The record player design optimization method based on circuit design simulation according to claim 1, characterized in that, In step S1, the mechanical sub-models include: According to the geometric structure, material properties and assembly relationship of the record player turntable, bearing, tone arm and counterweight assembly, a three-dimensional entity model is generated and spatial grid subdivision is performed; the material properties include elastic modulus, Poisson's ratio, material density and damping coefficient; Boundary conditions and constraints are applied to the grid model, including rotational constraints of the bearing, pivot constraints of the tone arm, and connection constraints with the base, thereby generating system mass matrix, stiffness matrix and damping matrix describing the structural dynamic behavior.

3. The record player design optimization method based on circuit design simulation according to claim 1, characterized in that, In step S1, the electromechanical transducer sub-models include: The stylus, needle shaft, suspension system and magnet are equivalent to a multi-degree-of-freedom mass-spring-damper system, and the input of the vibration equation is the force from the record groove wall; A magnetic field model based on the magnetic circuit reluctance method is established, which models the magnetic circuit formed by the permanent magnet, yoke, pole shoe and magnet driven by the needle shaft displacement as a variable changing the air gap length of the magnetic circuit. By calculating the rate of change of the total magnetic flux with time, the output voltage generated in the induction coil is solved according to Faraday's law of electromagnetic induction.

4. The jukebox design optimization method based on circuit design simulation of claim 1, wherein, In step S1, the electronic circuit sub-models include: A circuit netlist is established to accurately describe the types, parameter values and connection topological relationships of all electronic components in the cartridge amplifier circuit, including resistors, capacitors, inductors, operational amplifiers and transistors; A circuit netlist is established for the motor drive circuit, which describes the circuit structure of the servo control loop for controlling the constant speed rotation of the turntable, including the speed detection unit, error amplifier and power drive stage.

5. The record player design optimization method based on circuit design simulation according to claim 4, characterized in that, In step S2, the bidirectional data coupling interface is used to exchange the following data at each simulation time step: The mechanical sub-model transmits the calculated displacement and velocity of the end of the tone arm in three-dimensional space to the electromechanical transducer sub-model as the boundary conditions of the stylus vibration system thereof; The electromechanical transducer sub-model transmits the calculated original output voltage across the induction coil to the electronic circuit sub-model as the input signal of the cartridge amplifier; The electronic circuit sub-model feeds back the load current caused by the calculated input impedance of the cartridge amplifier to the electromechanical transducer sub-model to correct the electromagnetic damping force of the induction coil; The motor driving circuit in the electronic circuit sub-model transmits the output driving torque to the mechanical sub-model to drive the turntable model to rotate, and the mechanical sub-model feeds back the instantaneous angular velocity of the turntable to the speed detection unit in the electronic circuit sub-model to form a closed-loop control.

6. The record player design optimization method based on circuit design simulation according to claim 5, characterized in that, In the step S4, the key design parameters include: In the mechanical sub-model, the effective length, effective mass, overhang, wall thickness, material type of the tone arm, and the mass and position of the counterweight; In the electromechanical transducer sub-model, the equivalent mass of the stylus, the compliance and damping coefficient of the suspension system, and the magnetic field strength of the permanent magnet; In the electronic circuit sub-model, the values of the input stage resistance and capacitance of the cartridge amplifier, and the parameters of the key components in the feedback network.

7. The record player design optimization method based on circuit design simulation according to claim 6, characterized in that, In the step S4, the specific process of the genetic algorithm includes: Initialization of the population, randomly generate an initial population consisting of multiple individuals within the preset value range of the design parameters, and each individual represents a complete set of turntable design parameters; Fitness evaluation, for each individual in the population, construct the corresponding unified multi-physics domain model according to its design parameters, perform collaborative simulation and calculate its audio performance indicators, and then convert multiple performance indicators into a single fitness value through weighted summation or Pareto sorting; Selection operation, according to the size of the individual fitness value, adopt roulette selection method or tournament selection method to select excellent individuals from the current population into the next generation; Cross operation, pair the selected individuals, and exchange part of the parameter gene fragments of the two paired individuals at the randomly selected crossover point with a preset crossover probability to generate new offspring individuals; Mutation operation, randomly change the value of one or more parameter genes of the newly generated offspring individuals with a preset mutation probability to increase the diversity of the population; Repeat the above fitness evaluation, selection, crossover and mutation operations until the overall fitness of the population no longer improves significantly or reaches the preset maximum evolution generation, and output the design parameters corresponding to the individual with the highest fitness in the final population as the optimal design scheme.

8. The jukebox design optimization method based on circuit design simulation of claim 1, wherein, In the step S3, the audio performance indicators include total harmonic distortion plus noise, intermodulation distortion, signal-to-noise ratio, left-right channel separation, and jitter rate.

9. The record player design optimization method based on circuit design simulation according to claim 8, characterized in that, The calculation of the total harmonic distortion plus noise includes: Performing fast Fourier transform on the original output signal sequence to obtain its frequency spectrum distribution; Extracting the fundamental frequency amplitude at the fundamental frequency and the harmonic amplitudes at the integer multiple harmonic frequencies; Adding the square sums of all harmonic amplitudes and the square sum of the noise floor, and then taking the square root, and dividing by the fundamental frequency amplitude to obtain the percentage value of the total harmonic distortion plus noise.

10. A record player design optimization system based on circuit design simulation, characterized by, The application relates to a record player multi-physical domain model simulation system, which comprises the following modules: a unified multi-physical domain model construction module, which is used for generating a unified multi-physical domain model containing a mechanical submodel, an electromechanical transducer submodel and an electronic circuit submodel according to the geometric structure, material properties and circuit topology of a record player; a cooperative simulation execution module, which is connected with the unified multi-physical domain model construction module and is used for iteratively solving the unified multi-physical domain model in a time domain, realizing data exchange among the submodels through a bidirectional data coupling interface, simulating the whole process of a record player from sound pickup to signal output and outputting an original electric signal sequence; an audio performance index extraction module, which is connected with the cooperative simulation execution module, is used for receiving the original electric signal sequence and performing spectrum analysis and statistical calculation on the original electric signal sequence, and extracts total harmonic distortion plus noise, signal-to-noise ratio, sound channel separation degree, intermodulation distortion and jitter rate; a multi-target design optimization module, which is connected with the unified multi-physical domain model construction module and the audio performance index extraction module, is used for taking the audio performance indexes as optimization targets, taking key design parameters of the record player as variables, automatically adjusting the design parameters through a built-in genetic algorithm and driving the model construction module and the simulation execution module to perform cyclic calculation until a set of design parameter combinations is found, so that the overall audio performance indexes reach the optimal state.

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