PC housing impact test integrated system based on multi-dimensional control

Abstract

The application relates to the technical field of structure testing, and discloses a PC shell impact test integrated system based on multidimensional control, which comprises a multi-axis pose adjusting mechanism, an electromagnetic load applying unit and a central control core. The central control core extracts a local normal vector on the surface of a to-be-tested piece and drives the mechanism to realize impact axis alignment. The current response of a driving winding in a detection stage is used to identify local dynamic stiffness, and a main pulse waveform is reconstructed accordingly. A feedback correction unit monitors real-time displacement signals and corrects trigger timing, so as to offset structural settlement. The application ensures that the impact load vertically invades the interior of a material, realizes physical consistency of peak load strain rates in different thickness regions, eliminates measurement bias, and improves the fidelity of structure response evaluation.

Description

Technical Field

[0001] This invention relates to an integrated system for impact testing of PC housings based on multidimensional control, belonging to the field of structural testing technology. Background Technology

[0002] Current assessments of the mechanical strength of electronic device housings employ impact testing systems to simulate the dynamic response of products under drop or collision conditions. The industry standard practice is to apply a load of preset energy to the test sample using an electromagnetically driven or gravity-driven impact device. As PC housings evolve towards thinner and lighter designs and more complex topologies, they exhibit structural characteristics such as large aspect ratios, variable wall thicknesses, and non-uniform curvature. In actual testing, the housing experiences asymmetric settlement due to its own weight while in a clamped state, and the geometric normal at the impact point dynamically changes with the surface curvature. This causes the existing axial load to generate an unexpected tangential slip component at the moment of contact, transforming the internal stress state of the material from pure compressive stress to a combined bending and shear stress driven by load bias. This masks the true strength limit of thin-walled structures under localized normal loads.

[0003] Besides insufficient alignment accuracy in the physical architecture, the control logic lags in its ability to dynamically perceive and adaptively correct complex curved surfaces. For example, the utility model patent CN213068521U discloses a PC board impact resistance testing device that uses a base, slider, and sleeve mechanical assembly to initially fix the sample and adjust its height. This manual alignment and mechanical positioning mode cannot meet the micron-level pose compensation requirements of modern PC shells. Due to the lack of real-time alignment logic for the impact axis and local normal, and the absence of an energy feedback closed loop for the local dynamic stiffness of the material, the load rate drifts due to geometric impedance fluctuations when dealing with areas of varying wall thickness or complex R-angles. The system cannot sense and offset the microscopic settlement caused by the workpiece's own weight, making it difficult to maintain constant physical boundary conditions during long-sequence testing, resulting in a disconnect between failure data and real physical conditions. Industry attempts have tried to optimize alignment accuracy by increasing frame rigidity or introducing a multi-axis pose adjustment platform, but these attempts not only significantly increase the hardware cost and maintenance difficulty of the system, but also fail to resolve the contradiction between test data and real physical boundary conditions in a laboratory environment due to the lack of a feedback closed loop between the load pulse and the sample's local dynamic impedance.

[0004] Therefore, the technical problem to be solved by this invention is how to achieve high-fidelity mechanical response evaluation of complex curved thin-walled parts by dynamically mapping the normal vector of the shell surface and impedance matching the impact load pulse. Summary of the Invention

[0005] To address the problems mentioned in the background art, the technical solution of the present invention is as follows: An integrated system for PC casing impact testing based on multi-dimensional control, comprising: A multi-axis pose adjustment mechanism is used to clamp the PC housing, which is the structural component under test, and adjust the spatial pose of the structural component under test. The electromagnetic load application unit is equipped with a drive winding and an impact head, and is used to apply impact load to the structure under test. The central control core is connected to both the multi-axis pose adjustment mechanism and the electromagnetic load application unit. The central control core includes: The geometric topology analysis module is used to obtain the three-dimensional digital model of the structure under test, extract the local normal vector at the impact point of the structure under test, and control the multi-axis pose adjustment mechanism to adjust the pose of the structure under test so that the local normal vector coincides with the impact axis of the electromagnetic load application unit. The contact damping sensing unit is used to control the drive winding to output a detection pulse during the initial detection stage when the impact head contacts the surface of the structure to be tested. By monitoring the current rise slope of the drive winding at the moment of contact, the local dynamic stiffness at the impact point is identified. The momentum balance compensation module is used to determine the momentum balance correction coefficient based on the local dynamic stiffness, and to reconstruct the pulse current drive waveform of the drive winding using the momentum balance correction coefficient, so that the peak load strain rate of the structure under test in different wall thickness regions remains physically consistent. The feedback correction unit is used to monitor the real-time displacement signal of the multi-axis posture adjustment mechanism and generate axial displacement deviation. In the unloaded section before the impact head contacts the structure under test, the triggering sequence of the detection pulse is dynamically corrected according to the axial displacement deviation to counteract the structural settlement caused by the self-weight of the structure under test.

[0006] Preferably, the feedback correction unit includes: a settlement calculation submodule, used to collect the axial displacement deviation of the multi-axis posture adjustment mechanism in the vertical direction in real time; and a pulse phase correction submodule, used to convert the axial displacement deviation into a nonlinear compensation gain of the electromagnetic thrust, and adjust the launch starting point coordinates of the drive winding to ensure that the actual coordinates of the physical collision between the impact head and the structure under test are consistent with the theoretical coordinates defined by the three-dimensional digital model, and the correction amount of the pulse phase correction submodule to the launch starting point coordinates is not less than the absolute value of the axial displacement deviation.

[0007] Preferably, the system further includes a thermal efficiency compensation module, which is used to: monitor the change in DC resistance of the drive winding during the interval between two adjacent impact actions; determine the temperature rise attenuation factor of the electromagnetic load application unit based on the change in DC resistance; and increase the compensation amount of the drive voltage for subsequent impact actions based on the temperature rise attenuation factor to offset the influence of the coil thermal effect of the drive winding on the magnetic field thrust, thereby maintaining the constantness of energy output in the long sequence of test cycles.

[0008] Preferably, the multi-axis pose adjustment mechanism includes a multi-axis servo drive component and a turntable. The multi-axis servo drive component is connected to the central control kernel and is used to receive pose adjustment commands generated by the geometric topology analysis module. By synchronously adjusting the tilt angle of the structure under test in the horizontal and vertical dimensions, it ensures that the topological structure of the surface of the structure under test is under pressure at the moment of impact.

[0009] Preferably, the contact damping sensing unit adopts a local stiffness inversion logic based on the fluctuation of the reverse induced electromotive force. The specific expression of the local stiffness inversion logic is as follows: ,in, The value represents the local dynamic stiffness of the structural component under test at the impact point. This is the instantaneous current value of the drive winding. To detect the duration of the pulse, The instantaneous impact velocity of the impact head. This is the inherent inductance coefficient of the drive winding.

[0010] Preferably, the momentum balance compensation module introduces characteristic frequency modulation into the pulse current drive waveform to suppress low-frequency resonance interference generated when the test component is impacted in the suspended area, ensuring that the stress gradient generated by the impact load penetrates into the interior of the test component.

[0011] Preferably, the electromagnetic load application unit is equipped with a laser aligner and a displacement encoder. The laser aligner is connected to the central control core and is used to assist in verifying the coincidence accuracy between the impact axis and the local normal vector. The displacement encoder is used to record the entire trajectory of the impact head and feed it back to the feedback correction unit.

[0012] Preferably, the multi-axis posture adjustment mechanism is equipped with a vacuum adsorption matrix and a flexible support pad. The vacuum adsorption matrix is ​​used to fix the non-impact surface of the structure under test without stress, and the flexible support pad is used to provide mechanical boundary support for the structure under test.

[0013] Preferably, the central control kernel also includes a data acquisition unit and a failure analysis module. The data acquisition unit is used to record the structural integrity data of the component under test after the impact action; the failure analysis module is used to compare the structural integrity data with a preset crack propagation threshold and automatically determine the dynamic fatigue life of the component under test.

[0014] Preferably, the multi-axis posture adjustment mechanism, the electromagnetic load application unit, and the central control core are all integrated into a shielded frame with a vibration isolation base. The shielded frame is used to isolate the influence of the external environment on the accuracy of the drive winding current monitoring and the accuracy of the local normal vector alignment.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. In the integrated impact test of PC housing, the local normal vector of the surface of the housing under test is calculated by the topology mapping unit, and the pose adjustment platform is controlled to adjust the pose of the housing under test so that the normal direction at the impact point coincides with the preset impact axis of the energy actuator. This avoids energy slippage when the impact load contacts the curvature change position, ensures that the test stress completely penetrates into the material, and solves the problem of falsely high strength data caused by physical alignment deviation.

[0016] 2. The feedback correction unit monitors the real-time displacement signal of the posture adjustment platform. During the no-load operation period before the energy actuator contacts the shell under test, it dynamically corrects the triggering sequence of the drive pulse based on the displacement change. It uses the nonlinear response characteristics of electromagnetic force to offset the structural settlement caused by the shell's own weight, so that the physical coordinates of the collision are highly consistent with the preset digital model definition, thus eliminating the systematic error caused by mechanical clearance to the test results.

[0017] 3. By utilizing the back-induced electromotive force fluctuation generated by the drive winding of the energy actuator during the contact dwell stage, the ratio of the current rise slope to the displacement change rate during the contact process between the impact head and the shell under test is extracted, thereby inverting the local dynamic stiffness at the impact point. Based on this stiffness characteristic, the driving waveform of the pulse current is reconstructed in real time to achieve the physical equivalence of strain rate under different structural regions, and eliminate the test bias caused by uneven shell wall thickness or stiffener distribution. Attached Figure Description

[0018] Figure 1 This is a flowchart of the multi-dimensional control logic and signal feedback closed loop of the system of the present invention; Figure 2 This is a block diagram illustrating the overall hardware architecture and module interaction principle of the system of the present invention. Detailed Implementation

[0019] The present invention will now be described in conjunction with specific embodiments. This section is intended to elaborate on the present invention in detail for explanation and illustration purposes, and is not intended to limit the scope of protection of the present invention.

[0020] This invention provides an integrated system for PC shell impact testing based on multi-dimensional control, including a multi-axis posture adjustment mechanism, an electromagnetic load application unit, and a central control kernel. The multi-axis posture adjustment mechanism is used to clamp the PC shell, which is the structural component under test, and adjust the spatial attitude of the structural component. The electromagnetic load application unit is equipped with a drive winding and an impact head for applying impact load to the structural component under test. The central control kernel is connected to both the multi-axis posture adjustment mechanism and the electromagnetic load application unit. The central control kernel includes a geometric topology analysis module, a contact damping sensing unit, a momentum balance compensation module, and a feedback correction unit. In PC shell impact testing, the complex curved surface features of the structural component under test can cause misalignment between the impact vector and the local normal vector, resulting in tangential slippage. To solve this problem, the geometric topology analysis module acquires a three-dimensional digital model of the structural component under test and extracts the local normal vector at the impact point. The geometric topology analysis module calculates the local normal vector at the impact point using the first-order partial derivative based on the surface equation of the impact coordinate point in the three-dimensional digital model. The central control kernel controls the multi-axis pose adjustment mechanism to adjust the pose of the structure under test, so that the local normal vector coincides with the impact axis of the electromagnetic load application unit; the multi-axis servo drive component receives the pose adjustment command generated by the geometric topology analysis module and synchronously adjusts the tilt angle of the structure under test in the horizontal and vertical dimensions to ensure that the topology of the surface of the structure under test is under pressure during the impact transient; the physical alignment of the local normal vector with the impact axis ensures that the impact load penetrates vertically into the material, eliminating the bias in strength data measurement caused by alignment deviation.

[0021] The PC shell exhibits localized mechanical impedance heterogeneity due to reinforcing ribs and variations in wall thickness, resulting in inconsistent strain rates under the same energy. During the initial detection phase of the impact head contacting the surface of the structural component under test, the contact damping sensing unit controls the drive winding to output a detection pulse. The feedback correction unit monitors the current rise slope of the drive winding at the moment of contact, identifying the local dynamic stiffness at the impact point. This contact damping sensing unit employs local stiffness inversion logic based on the fluctuation of the reverse induced electromotive force; the specific calculation formula is as follows: ,in, The local dynamic stiffness of the structural component under test at the impact point; This is the instantaneous current value of the drive winding; To detect the duration of the pulse; The instantaneous impact velocity of the impact head; The inherent inductance of the drive winding; for example, when the inherent inductance is... For 0.5H, the change in current 0.2A, time interval The value is 0.001s, and the instantaneous velocity of the impact is... The calculated local dynamic stiffness at a speed of 1.0 m / s The current is 100 N / m. The momentum balance compensation module determines the momentum balance correction coefficient based on the local dynamic stiffness and reconstructs the pulse current drive waveform of the drive winding using the momentum balance correction coefficient. By adjusting the current rise slope of the pulse waveform, the peak load strain rate of the structure under test in different wall thickness regions is kept physically consistent. In momentum balance compensation, the central control kernel stores the correlation data between wall thickness and current slope, and the momentum balance correction coefficient. The determination method is to collect the local dynamic stiffness from the contact damping sensing unit. With reference stiffness Compare the ratios. The measured stiffness at the impact point is expressed in N / m. The reference stiffness for a standard flat region with a thickness of 2mm is given in N / m. The momentum balance compensation module utilizes the momentum balance correction coefficient. For the rising slope of the drive current Linear correction, the formula satisfies The corrected rising slope is The unit is A / ms. The standard flat zone generates a preset strain rate reference current rise slope, in units of A / ms. The current steepness is changed by adjusting the duty cycle of the power drive circuit, so that the impact head generates a consistent peak load strain rate in the reinforcing rib support area and the thin-walled suspended area.

[0022] The thin-walled PC shell experiences structural settlement due to its own weight, causing the actual physical coordinates of the collision to deviate from the theoretical coordinates. The feedback correction unit monitors the real-time displacement signal of the multi-axis posture adjustment mechanism and generates axial displacement deviation. The settlement calculation submodule collects the axial displacement deviation of the multi-axis posture adjustment mechanism in the vertical direction in real time. In the unloaded section before the impact head contacts the structure under test, the pulse phase correction submodule converts the axial displacement deviation into a nonlinear compensation gain of the electromagnetic thrust and adjusts the launch starting coordinates of the drive winding. The correction amount of this launch starting coordinate is not less than the absolute value of the axial displacement deviation, ensuring that the actual coordinates of the physical collision between the impact head and the structure under test are consistent with the theoretical coordinates defined by the three-dimensional digital model. By dynamically correcting the triggering timing of the detection pulse, the system cancels out the structural settlement caused by the weight of the structure under test. The nonlinear compensation gain of the feedback correction unit adopts the gap function thrust correction equation, and the axial displacement deviation in the vertical direction of the structure under test is obtained by the settlement calculation submodule in the unloaded section. The absolute value of the deviation between the measured displacement and the theoretical position of the three-dimensional digital model is determined, in mm. The pulse phase correction submodule converts the axial displacement deviation into electromagnetic thrust nonlinear compensation gain. The formula satisfies , Dimensionless gain coefficient The magnetic field gradient has a preset correction factor of 1.25. Axial displacement deviation The initial gap at the theoretical starting position of the impact head, in mm, is determined according to the formula. Calculate the trigger lead time. The probe pulse trigger timing correction time, in milliseconds. The unloaded running speed of the impact head, in m / s, will be corrected. Injecting a driving timing sequence enables synchronization of impact position and energy output under gravity settlement conditions.

[0023] During long-sequence test cycles, the drive winding experiences a temperature rise due to the thermal effect of the current, leading to a decrease in kinetic energy output. The thermal efficiency compensation module applies a non-action-level detection pulse to the drive winding during the interval between two adjacent impact actions, monitoring the change in the DC resistance of the drive winding. The central control core determines the temperature rise attenuation factor of the electromagnetic load application unit based on the change in DC resistance. Based on the temperature rise attenuation factor, the system increases the drive voltage compensation for subsequent impact actions to counteract the influence of the coil thermal effect of the drive winding on the magnetic field thrust. The thermal compensation mechanism maintains the constancy of energy output throughout the test sequence. The system uses a failure analysis module to determine the fatigue life of the tested structure. During the dwell phase after the impact action, the electromagnetic load application unit switches to a passive sensing mode, using the drive winding to capture the induced current waveform caused by the internal mechanical oscillations of the tested structure. The data acquisition unit records the structural integrity data of the tested structure after the impact action. The failure analysis module analyzes the damping characteristics and frequency envelope of this induced current waveform and compares it with the preset crack propagation threshold, automatically determining the dynamic fatigue life of the tested structure and establishing a physical causal relationship between the load vector and structural failure characteristics.

[0024] Example 1: In a specific application of high-fidelity impact strength assessment for laptop PC casings with variable wall thickness and complex R-angle topology, the corner region of the tested structure exhibits local geometric curvature changes. When the electromagnetic load application unit applies an impact load to the tested structure, a slight deviation between the impact axis and the local tangential plane during the dynamic process causes the impact head to generate a tangential slip component along the shell surface at the moment of contact. This causes the strain field distribution inside the material to shift from a pure compression state to an uncontrolled bending-shear composite state driven by load bias, thereby masking the true strength limit of the tested structure under local normal load. To address the tangential slip obstacle, the central control kernel obtains the three-dimensional digital model at the impact point of the tested structure through the geometric topology analysis module and extracts the local normal vector. The geometric topology analysis module performs first-order partial derivative calculations on the surface equations of the three-dimensional digital model at the selected impact coordinate points to obtain the local normal vector used to characterize the local geometric features. The multi-axis posture adjustment mechanism is driven to adjust the spatial attitude of the turntable, so that the impact axis and the local normal vector are collinear, thereby ensuring that the load energy can penetrate vertically along the material thickness direction and eliminating the phenomenon of falsely high measurement data caused by alignment deviation.

[0025] To address the impedance heterogeneity caused by the uneven distribution of internal reinforcing ribs in the PC housing, the system utilizes a contact damping sensing unit to control the drive winding to output a detection pulse with a peak current of 0.1A to 0.3A during the initial detection phase when the impact head contacts the surface of the structural component under test. The local dynamic stiffness is inverted by monitoring the slope of the current rise at the moment of contact and combining this with the fluctuation of the back-induced electromotive force. The formula for calculating the local dynamic stiffness is as follows: ,in, The value represents the local dynamic stiffness of the structural component under test at the impact point. This is the instantaneous current value of the drive winding. To detect the duration of the pulse, The instantaneous impact velocity of the impact head. To drive the inherent inductance coefficient of the winding, the momentum balance compensation module reconstructs the main pulse current driving waveform based on the identified values, ensuring that the peak load strain rate experienced by the tested structural component in the stiffener support area and the thin-walled suspended area remains consistent, thus resolving the conflict between structural stiffness differences and the requirement for constant strain rate. Under the condition that the tested structural component experiences asymmetric settlement due to its own weight, the feedback correction unit collects the axial displacement deviation of the multi-axis posture adjustment mechanism in real time. The pulse phase correction submodule converts the axial displacement deviation into the corresponding electromagnetic thrust initial phase gain, dynamically correcting the triggering point of the probe pulse within microseconds to offset the mechanism's... The negative impact of the mechanical clamping gap on the collision coordinates ensures that the physical interaction between the impact head and the surface of the test structure matches the theoretical contact boundary defined by the three-dimensional digital model, eliminating measurement noise caused by systematic settlement. When the test task is completed, the failure mode of the test structure in the complex curved area is a compression crack driven by local normal load. The impact load displacement curves show a high degree of overlap in multiple sets of repeated experiments. The load transfer efficiency is maintained within the preset linear response range at different curvature points. The fracture energy index finally output by the system characterizes the dynamic response characteristics of the complex topological thin-walled component under normal loading conditions.

[0026] Example 2: The experiment aimed to verify the consistency of load application in complex curvature regions and under varying wall thickness conditions. The test platform was equipped with an electromagnetic drive source with a drive current resolution better than 0.01A and a displacement acquisition accuracy of 0.001mm. The data acquisition signal was sourced from the measured waveform of the laptop computer's A-part casing, where the sampling period was... The setting depends on the highest characteristic frequency of the reverse induced electromotive force signal. To satisfy the Nyquist sampling theorem and suppress high-frequency aliasing, the parameters Determined to satisfy the inequality The critical value, when measured At 50kHz, it is determined through calculation. 2 This establishes an initial sampling benchmark that balances data real-time performance with processor computational load. Specifically, the analog-to-digital converter of the central control core is configured with a sampling frequency of 100kHz to ensure the capture of subtle fluctuations in the current rising edge during the 0.1ms to 2.0ms transient process. Signal processing employs a sliding window with a length of 1024 sampling points, a fixed overlap rate of 50%, and a fourth-order low-pass digital filter with a cutoff frequency of 20kHz to filter out electromagnetic noise. The duration of each probe pulse is limited to 5.0ms. Furthermore, in the calculation of the current rising edge slope, only the linear segment data with sampled values ​​between 10% and 90% of the peak current is extracted and subjected to least squares fitting. To eliminate interference from initial contact resistance fluctuations and to simulate electromagnetic interference present in industrial settings, Gaussian white noise with a signal-to-noise ratio of 25 dB was actively superimposed on the test signal. The test system was divided into three groups: control group 1 used constant voltage drive without momentum compensation, control group 2 removed the feedback correction unit, and the test group used the complete system of this invention. Gradient testing of the detection pulse current intensity in the range of 0.05 A to 0.6 A revealed that when the peak current was below 0.1 A, the identification result deviated from the calibration value by more than 15%, and when the current exceeded 0.5 A, the drive winding entered the magnetic saturation region, causing nonlinear distortion of the induced electromotive force. Finally, 0.1 A to 0.3 A was determined to be the optimal detection current range.

[0027] Table 1: Dynamic verification data for different impedance gradient sites

[0028] Referring to Table 1, the system extracts differentiated current rise slopes for the central thin-walled region, the R-angle turning region, and the stiffener intersection region. The momentum balance compensation module then uses the identified local dynamic stiffness... The current steepness of the drive winding was adjusted so that the peak load deviation transmitted to the material surface was all within 2.0%. In contrast, the load rate deviation of control group 1 in the reinforcing rib support area reached 35.4%.

[0029] Example 3: This example combines Figures 1 to 2 A description of an integrated system for PC housing impact testing based on multidimensional control, such as... Figure 1As shown, the logic control flow revolves around the PC housing, the structural component under test subjected to impact loads. Considering the complex curved surface and variable wall thickness of the housing, the system uses a geometric topology analysis module to extract local normal vectors and calculate the three-dimensional digital model surface equations. This generates pose adjustment commands, which are transmitted to a multi-axis pose adjustment mechanism. This mechanism is equipped with a multi-axis servo drive assembly to adjust the spatial attitude of the test component. While completing clamping and attitude adjustment, it outputs real-time displacement signals to a feedback correction unit. The feedback correction unit monitors the real-time displacement signals and corrects the trigger timing of the detection pulses. The generated timing correction command is sent to an electromagnetic load application unit. This unit is equipped with a drive winding and an impact head to apply physical impact loads. The resulting drive winding current response is input to a contact damping sensing unit, which monitors the current rise slope and identifies local dynamic stiffness. The identified local dynamic stiffness is transmitted to a momentum balance compensation module to determine the momentum balance correction coefficient and reconstruct the pulse current drive waveform. The reconstructed drive waveform is finally fed back to the electromagnetic load application unit.

[0030] like Figure 2 As shown, the system hardware architecture is confined within a physical boundary formed by electromagnetic shielding and vibration isolation. The central hub is the central control host, i.e., the intelligent core. This host integrates modules for geometric topology analysis, contact damping sensing, momentum balance compensation, feedback correction control, thermal efficiency compensation, and failure life analysis. On one hand, the central control host sends attitude commands to the multi-axis posture adjustment platform and receives displacement feedback. The multi-axis posture adjustment platform includes a multi-axis servo drive, a precision turntable, and a vacuum adsorption matrix, and is connected to the PC shell under test through adsorption fixation. On the other hand, the central control host sends pulse waveforms to the electromagnetic load application system and receives current feedback. The electromagnetic load application system includes a drive winding and an impact head, a laser alignment device, and a displacement encoder, which is used to apply vertical impact to the PC shell under test.

[0031] Example 4: During a continuous 5000-cycle impact fatigue test on a high-fiber reinforced polycarbonate shell, the Joule heat continuously generated by the drive winding causes magnetic flux loss, resulting in nonlinear fluctuations in the impact kinetic energy output. The thermal efficiency compensation module controls the central control core to apply a 0.5A detection pulse to the drive winding and collect the current response signal during the 10ms interval between two adjacent impact actions. Ohm's law is used to determine the change in the DC resistance of the drive winding, and the compensated drive voltage is then calculated. The calculation formula is as follows: ,in, The compensated driving voltage is expressed in volts (V). The reference driving voltage is expressed in volts (V). The temperature coefficient of resistance of the driving winding material is set to 0.00393. The measured DC resistance value, in units of ; The reference resistance value at the initial ambient temperature, in units of When measured It is 10.42 and It is 10.00 and The calculated compensation voltage is 200.0V. The voltage gain is 203.3V, which directly affects the power drive bridge of the electromagnetic load application unit, eliminating the power output fluctuation caused by the Joule heating effect.

[0032] To address the microcrack accumulation phenomenon caused by long-sequence impacts, the failure analysis module initiates an energy dissipation spectrum extraction procedure after every 500 impact cycles. The central control core switches the electromagnetic load application unit to a passive sensing mode, where the drive winding captures the induced current waveform caused by internal mechanical oscillations in the structure under test. The failure analysis submodule performs a discrete Fourier transform on the induced current waveform and extracts the damping characteristic value. Crack propagation threshold The determination method is as follows: A pre-set microcrack test is performed on an undamaged sample, and the damping response value at the structural failure critical point is recorded. 115% of this critical value is determined as the judgment threshold. When the system monitors the damping characteristic value within three consecutive sampling periods... All exceeded the crack propagation threshold. At that time, it is determined that structural failure has occurred at the impact site; this determination logic establishes a quantitative mapping from the frequency drift of the induced current to the physical damage state of the material, realizing closed-loop monitoring of impact loading and damage degree; the momentum balance compensation module is based on the local dynamic stiffness identified by the contact damping sensing unit. The momentum balance compensation module reconstructs the pulse current waveform in real time by adjusting the duty cycle of the pulse width modulation signal to change the slope of the rising edge of the drive current. slope With local dynamic stiffness The correlation is positively proportional; when the high impedance characteristics of the reinforcing rib area are identified during the detection phase, the algorithm automatically increases the duty cycle of the pulse width modulation signal to increase the current growth rate, ensuring that the impact head can produce a physically consistent momentum retention effect when contacting walls of different thicknesses; after completing 5000 impact cycles, the standard deviation of the measured load peak converges to 0.82N, proving that the system has adaptive correction capability when dealing with impedance reference drift caused by fatigue characteristics.

[0033] Example 5: When the system faces discrete mechanical impedance conditions of different production batches of polymer structural components, the integrated system executes a benchmark calibration procedure before initiating the impact test sequence. The geometric topology analysis module drives the multi-axis pose adjustment mechanism to adjust the structural component under test to the theoretical horizontal pose. The central control core initiates a microsecond-level frequency sweep excitation action when the electromagnetic load application unit is in an unloaded state. The data acquisition unit captures the amplitude sequence of the induced current generated by the drive winding and performs a fast Fourier transform. The initial energy distribution vector is determined by calculating the obtained spectral envelope characteristics. This procedure is used to establish the mechanical characteristic fingerprint of the sample before it is damaged, reduce the dynamic stiffness identification error caused by the fluctuation of the molding process, and make the failure analysis module track the damage evolution under a unified physical scale.

[0034] When the system encounters background electromagnetic field fluctuations, the central control kernel performs high-speed sampling of the parasitic voltage signal across the drive winding before the detection phase begins. The feedback correction unit calculates the average power of the parasitic voltage signal within a 10ms sliding window and outputs the environmental interference gain factor. The failure analysis module is based on the environmental interference gain factor. Dynamically adjust the failure determination boundary and correct the crack propagation threshold. The calculation formula is as follows: ,in, This is the corrected crack propagation threshold; This is the damping reference value under standard conditions; The interference immunity factor is set to 1.15. This is an environmental interference gain factor that enables the failure determination logic to perceive changes in environmental noise and reduces the impact of common-mode interference on damping feature extraction, thereby improving the accuracy of failure diagnosis reproduction under field conditions.

[0035] Example 6: In the coordinate system calibration procedure for the integrated system pre-deployment of a laptop PC casing with complex curvature characteristics, the geometric topology analysis module drives the electromagnetic load application unit to perform detection actions at three non-collinear reference points on the surface of the structure under test. The central control kernel performs correlation calculations based on the physical space coordinates collected by the displacement encoder and the theoretical coordinates defined by the three-dimensional digital model, and obtains the translation offset vector through calculation. ,in A vector describing the workpiece clamping offset; The coordinate deviation values ​​for each axis, and the translation offset vector. The components are composed of the coordinate deviation values ​​of each axis. This procedure establishes a mapping benchmark between the physical space and the virtual mesh before testing, ensuring that the local methods extracted by the geometric topology analysis module in subsequent processes are applied to the vector... It is consistent with the normal direction of the actual pressure surface.

[0036] When dealing with the discrete fluctuations in the elastic modulus of different batches of polycarbonate materials, the multi-axis posture adjustment mechanism executes the equilibrium pressure calibration procedure of the vacuum adsorption matrix, and the central control core monitors the microscopic displacement of the non-impact surface of the structural component under test during the vacuum adsorption start-up phase. ,in The displacement of the structural component under test caused by the clamping force is expressed in mm. The system linearly changes the adsorption negative pressure by adjusting the control voltage of the vacuum generator. This causes the clamping stress acting on the surface of the structure under test to be in a micro-displacement. Within a constraint range of less than 0.005 mm, the adsorption negative pressure The calculation formula is as follows: ,in, This is the adsorption negative pressure, expressed in kPa. This is the proportionality coefficient; The elastic modulus of the material is expressed in MPa. This specification determines the dynamic input value of the clamping load through material properties, thereby reducing the local dynamic stiffness caused by clamping prestress. Identify biases to ensure that the mechanical boundary conditions of different batches of samples in the test sequence are physically consistent.

[0037] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. An integrated system for impact testing of PC housings based on multi-dimensional control, characterized in that, include: A multi-axis pose adjustment mechanism is used to clamp the PC housing, which is the structural component under test, and adjust the spatial pose of the structural component under test. The electromagnetic load application unit is equipped with a drive winding and an impact head, and is used to apply impact load to the structure under test. The central control core is connected to both the multi-axis pose adjustment mechanism and the electromagnetic load application unit. The central control core includes: The geometric topology analysis module is used to obtain the three-dimensional digital model of the structure under test, extract the local normal vector at the impact point of the structure under test, and control the multi-axis pose adjustment mechanism to adjust the pose of the structure under test so that the local normal vector coincides with the impact axis of the electromagnetic load application unit. The contact damping sensing unit is used to control the drive winding to output a detection pulse during the initial detection stage when the impact head contacts the surface of the structure to be tested. By monitoring the current rise slope of the drive winding at the moment of contact, the local dynamic stiffness at the impact point is identified. The momentum balance compensation module is used to determine the momentum balance correction coefficient based on the local dynamic stiffness, and to reconstruct the pulse current drive waveform of the drive winding using the momentum balance correction coefficient, so that the peak load strain rate of the structure under test in different wall thickness regions remains physically consistent. The feedback correction unit is used to monitor the real-time displacement signal of the multi-axis posture adjustment mechanism and generate axial displacement deviation. In the unloaded section before the impact head contacts the structure under test, the triggering sequence of the detection pulse is dynamically corrected according to the axial displacement deviation to counteract the structural settlement caused by the self-weight of the structure under test.

2. The integrated system for PC housing impact testing based on multi-dimensional control according to claim 1, characterized in that, The feedback correction unit includes: a settlement calculation submodule, used to collect the axial displacement deviation of the multi-axis posture adjustment mechanism in the vertical direction in real time; and a pulse phase correction submodule, used to convert the axial displacement deviation into the nonlinear compensation gain of the electromagnetic thrust, and adjust the launch starting point coordinates of the drive winding to ensure that the actual coordinates of the physical collision between the impact head and the structure under test are consistent with the theoretical coordinates defined by the three-dimensional digital model, and the correction amount of the pulse phase correction submodule to the launch starting point coordinates is not less than the absolute value of the axial displacement deviation.

3. The integrated system for PC housing impact testing based on multi-dimensional control according to claim 1, characterized in that, The system also includes a thermal efficiency compensation module, which is used to: monitor the change in DC resistance of the drive winding during the interval between two adjacent impact actions; determine the temperature rise attenuation factor of the electromagnetic load application unit based on the change in DC resistance; and increase the drive voltage compensation amount of subsequent impact actions based on the temperature rise attenuation factor to offset the influence of the coil thermal effect of the drive winding on the magnetic field thrust, thereby maintaining the constantness of energy output in long-sequence test cycles.

4. The integrated system for PC housing impact testing based on multi-dimensional control according to claim 1, characterized in that, The multi-axis pose adjustment mechanism includes a multi-axis servo drive component and a turntable. The multi-axis servo drive component is connected to the central control kernel and is used to receive pose adjustment commands generated by the geometric topology analysis module. By synchronously adjusting the tilt angle of the structure under test in the horizontal and vertical dimensions, it ensures that the topology of the surface of the structure under test is under pressure at the moment of impact.

5. The integrated system for PC housing impact testing based on multi-dimensional control according to claim 1, characterized in that, The contact damping sensing unit adopts local stiffness inversion logic based on the fluctuation of the reverse induced electromotive force. The specific expression of the local stiffness inversion logic is as follows: ,in, The value represents the local dynamic stiffness of the structural component under test at the impact point. This is the instantaneous current value of the drive winding. To detect the duration of the pulse, The instantaneous impact velocity of the impact head. This is the inherent inductance coefficient of the drive winding.

6. The integrated system for PC housing impact testing based on multi-dimensional control according to claim 5, characterized in that, The momentum balance compensation module introduces characteristic frequency modulation into the pulse current drive waveform to suppress low-frequency resonance interference generated when the structure under test is subjected to impact in the suspended area.

7. The integrated system for PC housing impact testing based on multi-dimensional control according to claim 1, characterized in that, The electromagnetic load application unit is equipped with a laser aligner and a displacement encoder. The laser aligner is connected to the central control core and is used to assist in verifying the coincidence accuracy of the impact axis and the local normal vector. The displacement encoder is used to record the entire trajectory of the impact head and feed it back to the feedback correction unit.

8. The integrated system for PC housing impact testing based on multi-dimensional control according to claim 1, characterized in that, The multi-axis posture adjustment mechanism is equipped with a vacuum adsorption matrix and flexible support pads. The vacuum adsorption matrix is ​​used to fix the non-impact surface of the structure under test without stress, and the flexible support pads are used to provide mechanical boundary support for the structure under test.

9. The integrated system for PC housing impact testing based on multi-dimensional control according to claim 1, characterized in that, The central control kernel also includes a data acquisition unit and a failure analysis module. The data acquisition unit is used to record the structural integrity data of the structure under test after the impact action; the failure analysis module is used to compare the structural integrity data with the preset crack propagation threshold and automatically determine the dynamic fatigue life of the structure under test.

10. The integrated system for PC housing impact testing based on multi-dimensional control according to claim 1, characterized in that, The multi-axis posture adjustment mechanism, electromagnetic load application unit, and central control core are all integrated into a shielded frame with a vibration isolation base. The shielded frame is used to isolate the influence of the external environment on the accuracy of drive winding current monitoring and local normal vector alignment.

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