Automobile air intake grille motor high and low temperature test system

Abstract

The application belongs to the technical field of automobile air intake grille motor testing, and specifically discloses a high-low temperature test system for an automobile air intake grille motor, wherein a full-range temperature range is divided into three intervals according to a brittle temperature point of motor material and a demagnetization temperature point of motor magnetic material, and differentiated temperature node division is implemented, so that the temperature excitation of the test is more suitable for the material property mutation characteristics, the detection rate of the key failure temperature range is significantly improved, and then when the temperature nodes are tested according to the division, the torque and angle test is only performed after the double steady states of the environmental temperature and the motor winding resistance both reach the steady state condition of the target temperature node, the distortion of transient data is effectively avoided, finally, when the test result is obtained, the correlation model between the torque and the angle is established, and the temperature-failure mode mapping relationship is constructed, the limitation of traditional isolated analysis is broken through, and the accuracy and interpretability of fault diagnosis are significantly improved.

Description

A high and low temperature testing system for automotive grille motors Technical Field

[0001] This invention belongs to the field of automotive grille motor testing technology, and specifically discloses an automotive grille motor high and low temperature testing system. Background Technology

[0002] The automotive grille motor, also known as an active grille actuator, is a key component of automotive thermal management. It controls the opening and closing angle of the grille louvers to achieve rapid warm-up and optimized heat dissipation. Given that vehicles operate globally and must withstand extreme environments, the internal material properties of the automotive grille motor, as an external component exposed at the front edge of the engine compartment, are susceptible to temperature-related influences. Therefore, to ensure its functional reliability across the entire temperature range, systematic high and low temperature environmental adaptability testing must be conducted to verify its operational stability throughout its entire lifecycle.

[0003] When conducting high and low temperature environmental adaptability tests on automotive grille motors, torque and angular motion characteristics are two core indicators for evaluating their electromechanical performance and functional reliability. The torque parameter directly reflects the motor's driving capability and the load state of the transmission system, while the angle characterizes the actuator's dynamic tracking accuracy and motion integrity in response to control commands.

[0004] However, current testing methods still have several technical defects, which limit the accuracy of test results and the depth of fault diagnosis. Specifically: First, traditional testing schemes usually use equidistant temperature sampling to cover a preset temperature range, without considering the nonlinear thermal response characteristics of the functional materials inside the motor, especially the phase transition or glass transition that may occur at specific temperatures. Since the material properties will change abruptly near the phase transition point, the motor load torque and motion characteristics will deteriorate sharply. Equidistant sampling is very likely to miss such critical temperature points, resulting in the failure to detect the critical failure temperature range, making it impossible to accurately identify the starting boundary of performance degradation, which seriously weakens the effectiveness of the test.

[0005] Second: In the existing tests, torque and angle performance tests are started immediately after the ambient temperature chamber reaches the set temperature node. A strict thermodynamic steady-state determination mechanism has not been established. As a complex system with uneven heat capacity distribution, the temperature response of the key internal components of the motor lags behind the ambient temperature. When the test is carried out before the internal thermal equilibrium is reached, there is a significant deviation between its actual operating temperature and the target ambient temperature. The measured torque and angle response data reflect the transient non-equilibrium state, rather than the true steady-state performance at the target temperature, which leads to distorted test data and reduces the repeatability and reliability of the results.

[0006] Third: Existing technologies typically process and analyze torque and angle data acquired at different temperature nodes independently, lacking the exploration of the intrinsic correlation between multiple parameters. The performance degradation of motor systems is often the result of multi-physical field coupling. Isolated analysis makes it difficult to reveal the synergistic evolution law between performance parameters, making it difficult to effectively identify and accurately locate potential fault mechanisms, thus limiting the in-depth application value of test data in reliability improvement. Summary of the Invention

[0007] In view of this, the present invention aims to propose a high and low temperature testing system for automotive air intake grille motors, which effectively solves the problems mentioned in the background art by focusing on the optimization of temperature excitation, test conditions and data analysis during the testing process.

[0008] The objective of this invention can be achieved through the following technical solution: a high and low temperature testing system for an automotive grille motor, comprising: a temperature node division module: dividing the full-range temperature range of the high and low temperature environment test chamber into several temperature nodes according to the critical characteristics of material properties.

[0009] Test environment control module: The motor under test is installed on the test fixture, and the high and low temperature environment test chamber is driven to perform temperature locking control according to the divided temperature nodes.

[0010] Motor torque testing module: When the motor reaches the steady state at each temperature node, the rated voltage is applied to the motor. The peak torque at the moment of motor start-up is captured by the torque sensor. Then, the motor is driven to run at the rated speed to collect the steady-state torque fluctuation characteristics.

[0011] Motor angle testing module: When entering the steady state at each temperature node, a full open / full close command is sent. The duration from the issuance of the command to the first entry of the angle into the target angle tolerance zone is recorded as the angle response time. After that, a half open command is sent. The angle sensor measures the angle motion trajectory of the motor output shaft and extracts the differential features of the angle motion trajectory as the trajectory smoothness.

[0012] Cross-diagnostic module: Generates starting torque-temperature curve, response time-temperature curve, torque fluctuation-temperature curve and trajectory smoothness-temperature curve based on test results, and identifies characteristic abrupt change points of each curve to establish temperature-failure mode mapping relationship.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The present invention divides the full-range temperature range into three intervals based on the brittle transition temperature point of motor material and the demagnetization temperature point of motor magnetic material, and implements differentiated temperature node division, so that the temperature excitation of the test is more in line with the material property change characteristics, significantly improves the detection rate of key failure temperature range, accurately identifies the performance degradation start boundary, effectively avoids missed detection, and greatly improves the pertinence and accuracy of high and low temperature tests.

[0014] 2. This invention determines the system's thermal balance by monitoring the dual steady state of ambient temperature and motor winding resistance during the temperature node test. Torque and angle tests are only performed after both have reached the steady state conditions of the target temperature node, ensuring that the test is based on real thermal steady-state conditions, effectively avoiding transient data distortion, and significantly improving the repeatability and reliability of the test results.

[0015] 3. When testing the motor torque and angle results at different temperature nodes, this invention establishes a correlation model between torque and angle, constructs a temperature-fault mode mapping relationship, and achieves accurate identification and attribution of typical faults such as abnormal transmission resistance and electromagnetic interference coupling. This breaks through the limitations of traditional isolated analysis, significantly improves the accuracy and interpretability of fault diagnosis, and provides strong support for product design optimization and reliability assessment. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 is a schematic diagram of the system composition in this invention.

[0018] Figure 2 is a diagram of the temperature node division operation in this invention.

[0019] Figure 3 is a flowchart of the process for obtaining the steady-state time corresponding to the temperature node in this invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] This invention proposes a high and low temperature testing system for an automotive grille motor, comprising a temperature node division module, a test environment control module, a motor torque testing module, a motor angle testing module, and a cross-diagnostic module.

[0022] As shown in Figure 1, the temperature node division module is connected to the test environment control module, which is connected to the motor torque test module and the motor angle test module respectively. Both the motor torque test module and the motor angle test module are connected to the cross-diagnosis module, realizing a closed-loop data flow from temperature excitation setting to environmental execution, and then to multi-dimensional data acquisition and fusion diagnosis.

[0023] In the high and low temperature adaptability test of automotive grille motors, output torque reflects driving capability and load status, while angular response characterizes motion accuracy and command tracking capability. Both together determine the system's functional integrity, thus serving as core indicators for evaluating its electromechanical performance and functional reliability. Motor torque includes starting torque and running torque. Starting torque refers to the peak torque required to start the motor and overcome the maximum static friction and mechanical resistance of the transmission system when stationary, reflecting its low-temperature starting capability. Running torque refers to the continuous torque required to maintain the opening and closing motion of the louvers during dynamic operation, reflecting steady-state load characteristics. Angular response includes response time and angular motion trajectory. Angle response time refers to the time from receiving the control command to the actuator reaching the target angle tolerance band, characterizing the system's dynamic response speed. Angular motion trajectory refers to the time-domain curve of the actuator's rotation angle changing over time during motion, reflecting the smoothness of the motion.

[0024] The temperature node division module is used to divide the full-range temperature range of the high and low temperature environment test chamber into several temperature nodes according to the critical characteristics of material properties.

[0025] It should be noted that the present invention uses a high and low temperature environment test chamber as a temperature control platform, which can accurately simulate and control the wide temperature range environment required for testing, provide programmable temperature stress conditions for the air intake grille motor, and ensure that its performance test under the set temperature field is real and effective.

[0026] The full-range temperature range of the high and low temperature environment test chamber is set according to the regional requirements of the vehicle application. Specifically, the minimum and maximum operating temperatures are determined based on the extreme climatic conditions of the vehicle's target market, such as cold, tropical, and high-altitude regions.

[0027] Referring to Figure 2, as a preferred implementation of the above module, the specific process of dividing the temperature nodes is as follows: Based on the brittle temperature point of the motor material and the demagnetization temperature point of the motor magnetic material, the full-range temperature range is divided into the temperature range below the brittle temperature point of the material, the temperature range above the demagnetization temperature point of the magnetic material, and the temperature range in between, which are respectively denoted as the low-temperature risk range, the high-temperature risk range, and the stable operation range.

[0028] It is important to understand that motor failure at extreme temperatures does not occur uniformly, but is driven by abrupt changes in the physical state of specific materials at specific temperature points. The brittle transition temperature of motor materials refers to the critical temperature at which internal polymer materials such as plastic gears, housings, and seals transition from a ductile to a brittle state at low temperatures. Below this temperature, the impact toughness of the material decreases significantly, making it prone to cracking or fracture under start-stop impact loads.

[0029] The demagnetization temperature of motor magnetic materials refers to the starting temperature at which the magnetic properties of permanent magnets such as neodymium iron boron in the motor begin to decay nonlinearly and rapidly at high temperatures. Exceeding this point will lead to irreversible degradation of the motor's output capacity.

[0030] These two temperature points can be obtained from the material's technical specifications based on its properties. Based on these two points, the material can be divided into a low-temperature risk zone, a high-temperature risk zone, and a stable operating zone. In the low-temperature and high-temperature risk zones, the material faces fundamental physical mechanisms that could lead to functional failure. In the stable operating zone, the material operates in its designed state, with relatively gradual and predictable performance changes. By strategically dividing the temperature range into different temperature nodes, the critical temperature domains where sudden changes in material properties cause performance degradation can be accurately identified, enabling refined temperature node layout in high-risk areas. Compared to equal-interval division across the entire temperature range, this approach avoids missing critical failure points, improving testing effectiveness and engineering guidance value.

[0031] The characteristic curve of the motor stator winding resistance as a function of temperature is obtained, and the average slope of the curve in the stable operating range is calculated. Then, the average slope is combined with the resistance change tolerance caused by the unit temperature change allowed by the motor design to determine the temperature step size. Based on the temperature step size, the stable operating range is sampled at equal intervals to generate a set of temperature nodes in the stable operating range.

[0032] It should be noted that the main factor affecting motor performance is the thermal drift of the winding resistance. The winding resistance is positively correlated with temperature, and its characteristics are approximately linear functions within the stable operating range, meaning the resistance-temperature curve has an approximately constant slope. For linear systems, equidistant sampling can achieve optimal information representation, fully reconstructing the trend with the fewest measurement points.

[0033] Furthermore, the expression for determining the temperature step size is as follows: ,in This indicates the tolerance of resistance change caused by a unit temperature change in motor design. This represents the average slope of the curve. This represents the temperature step size. The tolerance for resistance change per unit temperature variation allowed by the motor design is the maximum resistance change caused by temperature that the motor's control strategy, power supply regulation, or torque output accuracy can accept under normal operating conditions. The average slope of the resistance-temperature curve in the stable operating range reflects the inherent physical characteristics of the winding material's resistance changing with temperature, i.e., the actual resistance change per unit temperature variation. Dividing these two values ​​reflects how much temperature change leads to a critical resistance change rate allowed by the design. This represents the maximum permissible temperature sampling step size without exceeding the system design margin. This method couples the rate of change of physical parameters with the engineering design margin, allowing the temperature step size to directly reflect the system's sensitivity to resistance drift and its acceptable range. This avoids oversampling in areas with gradual performance changes, significantly improving test efficiency, shortening the test cycle, and ensuring that critical performance deviations are not missed.

[0034] It should be noted that, due to the limited accuracy of temperature setting and control in high and low temperature environmental test chambers, overly precise non-integer step sizes are difficult to achieve accurately in actual operation and have no practical significance. Using integer or half-integer intervals is more convenient for test process planning, data recording, and result analysis, and improves engineering operability. Therefore, when determining the final temperature step size, the theoretical calculation value should be reasonably rounded, standard temperature increments should be given priority, and conservative design principles should be followed, tending to round down or select smaller conventional intervals to ensure sufficient test coverage, data integrity, and system reliability.

[0035] The inflection point of the characteristic curve of the motor stator winding resistance with temperature is captured in the low-temperature risk range. The detected inflection point is used to divide the low-temperature risk range into several continuous sub-ranges. The local average slope of the performance curve is calculated for each sub-range. Then, the local average slope is combined with the resistance change tolerance caused by the unit temperature change allowed by the motor design to dynamically determine the temperature step size of each sub-range. Thus, non-uniform sampling is performed in each sub-range according to the corresponding temperature step size to generate a set of temperature nodes in the low-temperature risk range.

[0036] It is important to understand that in the low-temperature risk range, the physical properties of the materials inside the motor change highly nonlinearly with temperature. At this time, although the winding resistance still changes with temperature, its rate of change may indirectly exhibit nonlinear characteristics due to the sharp increase in motor load. By capturing inflection points, we can identify the critical points of these material property abrupt changes or load state transitions, decomposing the complex nonlinear range into several approximately linear sub-ranges, laying the foundation for subsequent refined analysis.

[0037] Within each sub-interval, assuming a relatively stable resistance change trend, its local average slope is calculated. Combined with the design-allowed resistance change tolerance, the temperature step size is determined using the same principle as for the stable interval. Since the local average slope may differ between different sub-intervals—for example, the load changes drastically in the material phase transition region, resulting in a steeper change in equivalent resistance—the calculated temperature step size is dynamically adjusted. In sub-intervals with drastic performance changes, the temperature step size automatically decreases to achieve high-density sampling; in sub-intervals with gradual changes, the temperature step size is larger to perform sparse sampling.

[0038] Similarly, the temperature node division method of the low-temperature risk zone is applied to the high-temperature risk zone to generate a set of temperature nodes for the high-temperature risk zone.

[0039] It is important to understand that the physicochemical properties of the materials inside the motor also exhibit strong nonlinear evolution in the high-temperature risk range. In particular, the magnetic properties of permanent magnets decay nonlinearly as they approach their demagnetization inflection point, leading to a significant increase in the rate of change of motor load current and equivalent resistance. Therefore, the resistance-temperature curve in this range also exhibits obvious nonlinear characteristics. By implementing inflection point detection in the high-temperature region, key critical points such as abrupt changes in magnetic properties or the onset of material thermal aging can be identified, dividing the range into multiple sub-segments. Then, the local average slope of each sub-segment is calculated, and combined with the design-allowed resistance variation tolerance, the temperature division interval of each sub-segment is dynamically determined, and non-uniform sampling is performed.

[0040] It should be further noted that the slopes mentioned above refer to their absolute values, that is, only the magnitude and rate of change of resistance with temperature are considered, without being affected by the direction of change, so as to ensure that the calculation of temperature intervals is consistent and comparable in a physical sense.

[0041] All temperature nodes generated in the low-temperature risk zone, stable operation zone, and high-temperature risk zone are sorted in ascending order and merged into an ordered temperature node sequence.

[0042] The test environment control module is used to install the motor under test on the test fixture and drive the high and low temperature environment test chamber to perform temperature locking control according to the divided temperature nodes.

[0043] It is important to clarify that before the test is conducted, the motor under test must be installed on a dedicated test fixture to achieve mechanical fixation, standardized electrical interface connection, and precise alignment of the load simulation and angle measurement reference at the motion output end. This ensures the authenticity of the working condition simulation, the reliability of signal acquisition, and the accuracy of motion parameter measurement during the test.

[0044] The motor torque testing module is used to apply the rated voltage to the motor when it enters the steady state at each temperature node, capture the peak torque at the moment of motor start-up through the torque sensor, and then drive the motor to run at the rated speed to collect the steady-state torque fluctuation characteristics.

[0045] Referring to Figure 3, in one of the ways that the above scheme can be implemented, the steady state time of each temperature node includes the following: after entering each temperature node, the ambient temperature at the location of the motor under test is collected by the temperature sensor built into the low temperature environment test chamber.

[0046] The system calculates the temperature deviation between the current ambient temperature and the target temperature node in real time. When the temperature first enters the preset temperature tolerance range, the system records the entry time and starts tracking the duration of the maintenance.

[0047] The temperature tolerance range mentioned above refers to an allowable deviation range set around the target temperature node. It is used to determine whether the actual temperature inside the environmental test chamber has stabilized near the target value. For specific settings, please refer to the relevant environmental test standards for the provisions on temperature deviation.

[0048] The tracking duration is compared with the preset minimum stable duration. If the duration reaches the minimum stable duration, the current moment is marked as the environmental steady state time.

[0049] The minimum stable holding time mentioned above refers to the shortest time required for the ambient temperature to remain within the target temperature tolerance range after entering the tolerance range. It is used to determine whether the system has reached thermal steady state. Specifically, the thermal response time constant can be estimated based on the thermal conductivity, mass, and heat dissipation conditions of the motor material, and this can be used as the benchmark value for the minimum stable holding time.

[0050] It should be noted that ambient temperature may fluctuate momentarily due to the dynamic response of the control system or external disturbances, causing the temperature to occasionally cross into the tolerance range. By setting a duration tracking mechanism, requiring the temperature to remain within the tolerance range for a preset minimum stable duration, transient fluctuations can be effectively distinguished from true thermal equilibrium, filtering out misjudgments caused by short-term disturbances. This strategy ensures the macroscopic stability of environmental conditions is confirmed, avoiding testing based on transient data. When the duration reaches the target, it indicates that the external thermal environment has sufficiently stabilized, and the system has entered steady-state operating conditions.

[0051] After reaching the steady state of the environment, a small, constant DC detection current is applied to the motor windings through the test system, and the voltage across the windings is measured in real time. The real-time resistance is then calculated using Ohm's law.

[0052] It should be added that after determining that the ambient temperature has reached a steady state, it is necessary to further monitor the internal thermal steady state of the motor. The small constant DC detection current applied to the motor in this process refers to a DC detection current with a constant amplitude and much lower than the rated operating current, to ensure that the motor rotor does not rotate, so that the motor is in a static state during the resistance measurement process, and to avoid interference of the moving back EMF with the voltage sampling.

[0053] The instantaneous resistance change rate is calculated based on continuously collected resistance data and compared with the resistance change rate threshold. If all calculated instantaneous resistance change rates are less than the resistance change rate threshold within a continuous monitoring period, the end time of the monitoring period is recorded as the steady-state time of that temperature node.

[0054] In an example of the above scheme, the instantaneous resistance change rate can be calculated using the difference method between adjacent sampling points.

[0055] The resistance change rate threshold reflects the critical rate of change of resistance when it tends to stabilize. Specifically, it can be selected as the threshold by combining the thermal time constant of the winding and the target steady-state accuracy requirements, and choosing the typical rate of change when the resistance change enters the flat stage.

[0056] The monitoring period is used to confirm the continuous stability of resistance changes and prevent misjudgments caused by measurement noise or transient disturbances. Specifically, based on multiple sets of measured winding resistance-time relaxation curves, the duration distribution of the resistance change rate after entering the steady segment can be statistically analyzed. Based on this, the shortest continuous stable period that can reflect thermal equilibrium with high confidence can be determined and used as the basis for setting the monitoring period.

[0057] It is important to clarify that key performance parameters of a motor, such as output torque and response characteristics, are closely related to winding temperature. Winding temperature rise directly affects its electrical and thermodynamic behavior. Therefore, stable winding temperature is the most direct and fundamental indicator of the motor's overall performance reaching thermal equilibrium. Furthermore, resistance, as an electrical state quantity highly correlated with temperature, can be measured in real-time with non-invasive, high precision, and fast response by applying a microampere-level DC bias current, offering advantages such as low cost and strong anti-interference capabilities.

[0058] This invention selects the rate of change of resistance, rather than the absolute value of resistance, as the steady-state criterion. The core reason is that the rate of change directly reflects the dynamic evolution trend of the system. Even if the measured resistance value is close to the expected steady-state value, if the rate of change deviates significantly from zero, it indicates that the system is still in a transient heat transfer process and has not yet reached thermodynamic equilibrium. By setting a criterion that all instantaneous rates of change of resistance are below a threshold during a continuous monitoring period, the influence of random measurement noise or short-term disturbances can be effectively eliminated, ensuring the continuity and repeatability of the identified steady state. Finally, the end of the monitoring period is taken as the final steady-state moment, ensuring that the system is in a truly stable state for a period of time after this moment, providing a reliable time reference for subsequent motor torque and angle tests.

[0059] This invention fully considers that motor performance testing must be conducted under consistent and clearly defined thermodynamic and electromechanical stable conditions when entering each temperature node. Otherwise, the test results will be non-repeatable and measurement biased due to thermal transient effects or state drift, affecting the accuracy and reliability of the data. To this end, this method achieves accurate identification of the true stable state of the tested system through a dual collaborative determination mechanism of ambient temperature steady state and internal thermal steady state of the motor. This ensures that each performance test is started under complete thermal equilibrium conditions, thereby guaranteeing the scientific validity of high and low temperature test data.

[0060] In another possible way to achieve the above scheme, "applying a rated voltage to the motor and capturing the peak torque at the moment of motor start-up through a torque sensor" is a starting torque test. The specific test process is as follows: a mechanical overload protector is connected in series with the motor output shaft. This device maintains a rigid connection under normal torque. When the transmitted torque exceeds its preset disengagement threshold, it will slide or disengage, i.e., engage, thus protecting the transmission mechanism.

[0061] When the motor reaches the steady state at each temperature node, the rated voltage is applied, and the torque peak at the moment the overload protector engages is captured by the torque sensor.

[0062] It's important to understand that once the motor reaches thermal steady state at each temperature point, it is started with the rated voltage applied, and the torque sensor collects the output shaft torque in real time. The peak torque generated at the moment of startup must overcome the system's maximum static friction and mechanical resistance. If this peak value exceeds the preset tripping torque, the overload protector will engage. By capturing the instantaneous peak torque before the protector trips, the actual starting torque at that temperature can be obtained. This method utilizes the fact that the overload protector's tripping torque must be slightly higher than the expected maximum starting torque, and its tripping value must be known and stable. Thus, when the protector trips, it proves that the motor's starting capability has at least reached this value, and the peak value recorded by the sensor is the true starting torque.

[0063] In another possible implementation of the above scheme, "collecting steady-state torque fluctuation characteristics when the drive motor operates at its rated speed" is a test of operating torque. The specific test process is as follows: the drive motor operates at its rated speed, and under this operating condition, the time-domain torque waveform of the complete mechanical rotation cycle is captured.

[0064] It is important to know that the torque fluctuation of an electric motor is periodic, and its basic period is equal to one mechanical rotation cycle. To fully characterize the fluctuation characteristics of a cycle, data for at least one complete cycle must be collected.

[0065] The angular position signal of the motor rotor is acquired synchronously. The acquired time-domain torque waveform is converted into an angle domain according to the angular position. Within one mechanical rotation cycle, the time-domain torque waveform is resampled at preset equal angular intervals to generate a discrete angle-torque sequence.

[0066] Periodic fluctuation analysis was performed on the angle-torque sequence obtained by resampling to identify all local maxima and local minima in the sequence. Based on these extreme points, the upper and lower envelopes of torque fluctuations were constructed respectively.

[0067] The upper envelope connects the peak values ​​of each fluctuation cycle, and the lower envelope connects the trough values ​​of each cycle. Together, they define the upper and lower boundaries of torque fluctuations.

[0068] The area enclosed by the upper and lower envelopes is calculated as the characteristic of the steady-state torque fluctuation of the motor at that temperature node.

[0069] In an example applied to the above operations, the envelope area can be calculated through numerical integration. The envelope area is essentially the total energy of torque fluctuations within a mechanical cycle. It comprehensively reflects the amplitude and duration of torque fluctuations. Compared to a single indicator such as peak-to-peak value, the envelope area is an integral indicator that considers not only the maximum fluctuation amplitude but also the breadth and duration of the fluctuation throughout the entire cycle. The envelope area of ​​a torque with a small but persistent fluctuation amplitude may be larger than that of a brief spike, and a simple peak-to-peak value is easily affected by measurement noise or transient interference. The envelope line is usually formed by connecting local extrema and interpolation, which has a certain filtering effect on isolated noise points, making the area calculation more stable and better reflecting the true periodic fluctuation trend.

[0070] It's important to understand that during motor operation, factors such as cogging effect, winding distribution, and magnetic circuit saturation cause inherent periodic pulsations in the operating torque. Excessive torque fluctuations can lead to vibration, noise, and unstable speed, affecting system performance and lifespan. Therefore, analyzing the steady-state torque fluctuations of the motor is crucial. However, direct analysis in the time domain, especially with minor speed fluctuations, results in inconsistent time lengths for a single mechanical cycle, causing misalignment of the periodic features on the time axis and hindering accurate analysis. By resampling in the angle domain, the analysis benchmark is transformed from time to rotor mechanical angles, fundamentally eliminating the interference of speed fluctuations on the periodic analysis and ensuring strict alignment of the fluctuation features within the angle domain.

[0071] The motor angle testing module is used to send a fully open / fully closed command when the motor enters the steady state at each temperature node, and record the time from the issuance of the command to the first entry of the angle into the target angle tolerance zone as the angle response time. After that, a half-open command is sent, and the angle sensor measures the angle motion trajectory of the motor output shaft. The differential features of the angle motion trajectory are extracted as the trajectory smoothness.

[0072] As a preferred implementation of the above scheme, "sending a half-open command, measuring the angular motion trajectory of the motor output shaft by the angle sensor, and extracting the differential features of the angular motion trajectory as the trajectory smoothness" belongs to the angle motion trajectory test. The half-open command can be 50% half-open. The specific implementation process of extracting the differential features of the angular motion trajectory as the trajectory smoothness is as follows: perform Kalman filtering on the angular motion trajectory, and calculate its third-order time derivative based on the filtered angular motion trajectory using numerical differentiation.

[0073] It should be noted that, in order to effectively suppress the amplification effect of measurement noise, quantization error and high-frequency interference on high-order differential calculations, a Kalman filter is used to process the angular motion trajectory.

[0074] It should be further explained that the third time derivative is a physical quantity that measures the rate of change of acceleration. It directly reflects the degree of impact and discontinuity during motion. Compared with the first and second derivatives, the third time derivative is more sensitive to the subtle changes in motion quality.

[0075] Calculate the absolute integral of the third-order time derivative over the entire time interval of motion.

[0076] It should also be noted that the absolute value integral comprehensively quantifies the total intensity and duration of the abrupt acceleration changes throughout the entire motion process, and is a core indicator for evaluating the smoothness of motion. The larger the absolute value integral, the more severe the impact during the motion process, and the worse the smoothness.

[0077] Map the absolute value integral to the trajectory smoothness.

[0078] Applying this to the above operations, since trajectory smoothness is a positive performance indicator, a larger expected value indicates higher motion quality; while the absolute value integral of the third derivative of the angular trajectory is a negative indicator, a smaller value indicates better smoothness. To achieve consistency in the direction of the indicators, a reverse mapping is required. For example, a reciprocal form can be used for conversion. However, given that this integral has physical dimensions, a direct reciprocal still retains dimensions, which is not conducive to comparisons across operating conditions or machine models. Therefore, before the reciprocal mapping, a normalized reference value with the same dimensions, such as the design target value, should be introduced, and the dimensions should be eliminated through ratio calculations. The dimensionless quantity after normalization is then subjected to reciprocal processing, ultimately generating a dimensionless, positive trajectory smoothness indicator.

[0079] The cross-diagnostic module is used to generate starting torque-temperature curves, response time-temperature curves, torque fluctuation-temperature curves, and trajectory smoothness-temperature curves based on the test results, and to identify characteristic abrupt change points of each curve to establish a temperature-fault mode mapping relationship.

[0080] Optionally, four types of curves are generated as follows: the peak torque, steady-state torque fluctuation characteristics, angle response time and trajectory smoothness at all completed test temperature nodes are summarized and generated in a coordinate system with temperature nodes as the horizontal axis and peak torque, steady-state torque fluctuation characteristics, angle response time and trajectory smoothness as the vertical axis to generate the starting torque-temperature curve, response time-temperature curve, torque fluctuation-temperature curve and trajectory smoothness-temperature curve.

[0081] Further, optionally, the characteristic abrupt change points of each curve can be identified as follows: Inflection points are captured for the starting torque-temperature curve, response time-temperature curve, torque fluctuation-temperature curve, and trajectory smoothness-temperature curve, and the captured inflection points divide the curves into rising and falling segments.

[0082] The above-mentioned numerical differential detection curve inflection point can accurately locate the temperature range in which performance deteriorates significantly.

[0083] The temperature range corresponding to the rising segment in the starting torque-temperature curve is taken as the torque surge range.

[0084] The temperature range corresponding to the rising segment in the response time-temperature curve is taken as the response surge range.

[0085] The temperature range corresponding to the rising segment in the torque fluctuation-temperature curve is taken as the range where torque fluctuation intensifies.

[0086] The temperature range corresponding to the descending segment in the trajectory smoothness-temperature curve is taken as the trajectory deterioration range.

[0087] Alternatively, the temperature-failure mode mapping relationship can be established as follows: compare the torque surge interval with the response surge interval, calculate the ratio of the intersection and union of the two intervals on the temperature axis as the mechanical-dynamic coupling degradation synchronization index, and compare it with the first synchronization threshold. When the mechanical-dynamic coupling degradation synchronization index reaches the first synchronization threshold, this state is mapped as the transmission resistance abnormality fault mode.

[0088] It should be added that when there are multiple discontinuous sudden increase intervals on the starting torque-temperature curve or response time-temperature curve, all detected sudden increase intervals of starting torque are merged into one set. Similarly, all sudden increase intervals of response are merged into one set. Then, the ratio of the intersection to the union of the two sets is calculated as the mechanical-dynamic coupling degradation synchronization index.

[0089] By comparing the torque fluctuation aggravation interval with the trajectory deterioration interval, the ratio of the intersection and union of the two intervals on the temperature axis is calculated as the electromagnetic-motion quality coupling deterioration synchronization index, and compared with the second synchronization threshold. When the electromagnetic-motion quality coupling deterioration synchronization index is greater than the second synchronization threshold, this state is mapped as an electromagnetic interference coupling fault mode.

[0090] Similarly, when there are multiple discontinuous torque fluctuation aggravation intervals and trajectory deterioration intervals in the torque fluctuation-temperature curve and the trajectory smoothness-temperature curve, interval sets are constructed respectively. By calculating the intersection-union ratio of the two sets on the temperature axis, the electromagnetic-motion quality coupling deterioration synchronization index is obtained.

[0091] The first and second synchronization thresholds mentioned above are decision boundaries for distinguishing significant synchronization from accidental overlap. The thresholds that can maximize the discriminative power can be selected by statistically analyzing the mechanical-dynamic coupling degradation synchronization index and the electromagnetic-motion quality coupling degradation synchronization index of a large number of normal samples and known faulty samples.

[0092] It's important to explain that different physical faults trigger a series of specific performance responses at the system level. These responses are not only reflected in a single parameter but also in the coordinated changes of multiple related parameters. This coordinated change manifests as a specific degradation interval coupling pattern in the temperature-performance two-dimensional space. Traditional single-parameter threshold alarm methods are prone to false alarms or missed alarms. However, analysis based on multi-parameter synchronous degradation utilizes the systematic nature of the fault, significantly reducing sensitivity to single measurement noise or normal temperature drift, resulting in more reliable diagnostic results.

[0093] Using the ratio of the intersection to the union of temperature ranges as a measure of synchronicity is essentially the similarity of the two ranges on the temperature axis. This ratio is automatically normalized to the [0, 1] range, eliminating the influence of the absolute length of the range. The closer the ratio is to 1, the more it means that the degradation of the two performances occurs in almost the same temperature range, indicating that their driving mechanisms are highly consistent or strongly coupled.

[0094] When the mechanical-dynamic coupling degradation synchronization index reaches the first synchronization threshold, it indicates that the increase in starting torque (i.e., the decreased ability to overcome static friction and mechanical resistance) and the dynamic response hysteresis occur highly synchronously within the same temperature range. Both originate from an abnormal increase in the resistance of the mechanical transmission system, thus mapping to an abnormal transmission resistance fault mode.

[0095] When the electromagnetic-motion quality coupling degradation synchronization index exceeds the second synchronization threshold, it indicates a strong correlation between steady-state torque fluctuations and motion smoothness degradation in the temperature domain. This phenomenon is usually caused by periodic disturbance torques induced by electromagnetic excitation nonlinearities such as demagnetization and harmonic currents, which directly lead to mechanical motion impacts and trajectory distortions. The two are causally coupled, thus mapping to an electromagnetic interference coupled fault mode.

[0096] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, in the form of a computer program product.

[0097] Those skilled in the art will recognize that the modules and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0098] In addition, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0099] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0100] Finally, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high and low temperature testing system for an automotive air intake grille motor, characterized in that... ,include: Temperature Node Division Module: The full-range temperature range of the high and low temperature environmental test chamber is divided into temperature ranges below the embrittlement temperature of the motor material, temperature ranges above the demagnetization temperature of the magnetic material, and temperature ranges in between, based on the embrittlement temperature of the motor material and the demagnetization temperature of the magnetic material. These are respectively denoted as the low-temperature risk range, high-temperature risk range, and stable operating range. The low-temperature risk range, high-temperature risk range, and stable operating range are further divided into several temperature nodes. Test Environment Control Module: The motor under test is mounted on the test fixture, and the high and low temperature environmental test chamber is driven to perform temperature locking control according to the divided temperature nodes. Motor torque testing module: Apply rated voltage to the motor at the steady state moment of each temperature node, capture the peak torque at the moment of motor start-up, drive the motor to run at rated speed and collect steady-state torque fluctuation characteristics; Motor angle test module: When entering the steady state moment of each temperature node, a full open / full close command is sent, and the duration from the issuance of the command to the first entry of the angle into the target angle tolerance zone is recorded as the angle response time. Then, a half open command is sent to measure the angle motion trajectory of the motor output shaft and extract the differential features of the angle motion trajectory as the trajectory smoothness. Cross-diagnostic module: Generates starting torque-temperature curve, response time-temperature curve, torque fluctuation-temperature curve and trajectory smoothness-temperature curve based on test results, and identifies characteristic abrupt change points of each curve to establish temperature-failure mode mapping relationship.

2. The high and low temperature testing system for an automotive intake grille motor as described in claim 1, characterized in that: The implementation of the temperature node segmentation module is as follows: The characteristic curve of the motor stator winding resistance versus temperature is obtained, and the average slope of this curve within the stable operating range is calculated. Then, the average slope is combined with the resistance change tolerance caused by a unit temperature change allowed by the motor design to determine the temperature step size. Based on this temperature step size, the stable operating range is sampled at equal intervals to generate a temperature node set for the stable operating range. The characteristic curve of the motor stator winding resistance versus temperature is captured for inflection points in the low-temperature risk range. Using the detected inflection points, the low-temperature risk range is divided into several continuous sub-ranges. The local average slope of the performance curve is calculated for each sub-range. Then, the local average slope is combined with the resistance change tolerance caused by a unit temperature change allowed by the motor design to dynamically determine the temperature step size for each sub-range. Based on this, non-uniform sampling is performed within each sub-range according to the corresponding temperature step size to generate a temperature node set for the low-temperature risk range. Similarly, the characteristic curve of the motor stator winding resistance versus temperature is applied to the high-temperature risk range using the same temperature node segmentation method as the low-temperature risk range to generate a temperature node set for the high-temperature risk range. All temperature nodes generated in the low-temperature risk zone, stable operation zone, and high-temperature risk zone are sorted in ascending order and merged into an ordered temperature node sequence.

3. The high and low temperature testing system for an automotive intake grille motor as described in claim 1, characterized in that: The steady-state time of each temperature node includes the following: after entering each temperature node, the ambient temperature at the location of the motor under test is collected using a temperature sensor built into the low-temperature environment test chamber; the temperature deviation between the current ambient temperature and the target temperature node is calculated in real time; when the motor first enters the preset temperature tolerance range, the entry time is recorded, and the maintenance duration tracking is started; the tracked maintenance duration is compared with the preset minimum stable maintenance time; if the maintenance duration reaches the minimum stable maintenance time, the current time is marked as the environmental steady-state time.

4. The high and low temperature testing system for an automotive intake grille motor as described in claim 3, characterized in that: The steady-state time of each temperature node also includes the following: after entering the environmental steady-state time, a small constant DC detection current is applied to the motor winding through the test system, the voltage across its two ends is measured in real time, and the real-time resistance is calculated; the instantaneous resistance change rate is calculated based on the continuously collected resistance data and compared with the resistance change rate threshold. If all calculated instantaneous resistance change rates are less than the resistance change rate threshold in the continuous monitoring period, the end time of the monitoring period is recorded as the steady-state time of the temperature node.

5. The high and low temperature testing system for an automotive intake grille motor as described in claim 1, characterized in that: The peak torque at the moment of motor start-up is captured as follows: a mechanical overload protector is connected in series with the motor output shaft; when the motor reaches the steady state moment of each temperature node, the rated voltage is applied to the motor, and the peak torque at the moment of overload protector engagement is captured by a torque sensor.

6. The high and low temperature testing system for an automotive intake grille motor as described in claim 1, characterized in that: The steady-state torque fluctuation characteristics are acquired as follows: the drive motor operates at its rated speed, and under this operating condition, the time-domain torque waveform of a complete mechanical rotation cycle is captured; the angular position signal of the motor rotor is acquired synchronously, and the acquired time-domain torque waveform is converted into an angle domain according to the angular position; within one mechanical rotation cycle, the time-domain torque waveform is resampled at preset equal angular intervals to generate a discrete angle-torque sequence; periodic fluctuation analysis is performed on the resampled angle-torque sequence to identify all local maxima and local minima in the sequence, and the upper and lower envelopes of the torque fluctuation are constructed based on these extreme points; the area enclosed by the upper and lower envelopes is calculated as the characteristic of the steady-state torque fluctuation of the motor at that temperature node.

7. The high and low temperature testing system for an automotive intake grille motor as described in claim 1, characterized in that: The trajectory smoothness is extracted as follows: Kalman filtering is applied to the angular motion trajectory; based on the filtered angular motion trajectory, the third-order time derivative is calculated using numerical differentiation; the absolute value integral of the third-order time derivative over the entire motion time interval is calculated; and the absolute value integral is mapped to the trajectory smoothness.

8. The high and low temperature testing system for an automotive intake grille motor as described in claim 1, characterized in that: The process of generating the starting torque-temperature curve, response time-temperature curve, torque fluctuation-temperature curve, and trajectory smoothness-temperature curve based on the test results is as follows: The peak torque, steady-state torque fluctuation characteristics, angle response time, and trajectory smoothness at all completed test temperature nodes are summarized and used to generate the starting torque-temperature curve, response time-temperature curve, torque fluctuation-temperature curve, and trajectory smoothness-temperature curve within a coordinate system constructed with the temperature node as the horizontal axis and the peak torque, steady-state torque fluctuation characteristics, angle response time, and trajectory smoothness as the vertical axis.

9. The high and low temperature testing system for an automotive intake grille motor as described in claim 1, characterized in that: The identification of the characteristic abrupt change points of each curve is described below: Inflection points are captured for the starting torque-temperature curve, response time-temperature curve, torque fluctuation-temperature curve, and trajectory smoothness-temperature curve, respectively. The captured inflection points divide the curves into rising and falling segments; the temperature range corresponding to the rising segment in the starting torque-temperature curve is taken as the torque surge range; the temperature range corresponding to the rising segment in the response time-temperature curve is taken as the response surge range. The temperature range corresponding to the rising segment in the torque fluctuation-temperature curve is taken as the torque fluctuation aggravation range; the temperature range corresponding to the falling segment in the trajectory smoothness-temperature curve is taken as the trajectory deterioration range.

10. The high and low temperature testing system for an automotive intake grille motor as described in claim 9, characterized in that: The process of establishing the temperature-fault mode mapping relationship is as follows: Compare the torque surge interval with the response surge interval, calculate the ratio of the intersection and union of the two intervals on the temperature axis as the mechanical-dynamic coupling degradation synchronization index, and compare it with the first synchronization threshold. When the mechanical-dynamic coupling degradation synchronization index reaches the first synchronization threshold, this state is mapped as the transmission resistance abnormal fault mode. Compare the torque fluctuation aggravation interval with the trajectory degradation interval, calculate the ratio of the intersection and union of the two intervals on the temperature axis as the electromagnetic-motion quality coupling degradation synchronization index, and compare it with the second synchronization threshold. When the electromagnetic-motion quality coupling degradation synchronization index is greater than the second synchronization threshold, this state is mapped as the electromagnetic interference coupling fault mode.

Images