PXI-based household appliance control panel test method

Abstract

The invention discloses a PXI (PCI eXtensions for Instrumentation)-based household appliance control panel test method, which takes a PXI case with a built-in PXI main control module, a digital I / O (Input / Output) module and an oscilloscope card as a platform. Executing an automatic test process including hardware self-inspection, test script loading, key simulation and response acquisition, display signal acquisition and comparison, control logic and safety function test and report generation through the test software; a PXI digital I / O module, an oscilloscope card and the like are controlled by adopting a standardized and modularized hardware platform based on a PXI case and utilizing an automatic test program written by LabVIEW, user key operation is accurately simulated, signal excitation and abnormal working condition input are displayed, response signals, display data and state feedback of a control panel are collected at the same time, and the test accuracy of the PXI digital I / O module and the oscilloscope card is improved. Automatic testing of the whole process is achieved, and therefore subjectivity and inconsistency of manual operation are avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic equipment function test, and particularly relates to a household appliance control panel test method based on PXI. BACKGROUND

[0002] In the production and manufacturing of household appliances, the test panel is a key component for detecting the functions of household appliances, and the accuracy and stability of its performance are crucial for product quality evaluation. Currently, the test of the control panel of household appliances requires manual item-by-item testing and recording by test personnel using a multimeter, an oscilloscope, a signal generator and other general or special instruments.

[0003] The above method has the following disadvantages. First, it is easy to introduce errors, resulting in poor accuracy of test results. Second, the test process lacks unified standards, and there are differences in test results of different batches. With the rapid development of the household appliance industry and the continuous expansion of production scale, the requirements for product quality are increasing, and therefore higher requirements are put forward for automatic testing.

[0004] Therefore, in view of the above problems, the present application provides a household appliance control panel test method based on PXI. SUMMARY

[0005] In order to overcome the problems of poor accuracy of the traditional method and lack of unified standards in the test process, the present application provides a household appliance control panel test method based on PXI. The method integrates multiple functional modules to realize automatic testing of the key response, display function, control logic and safety protection of the test panel of household appliances, thereby improving test efficiency and the accuracy of test results, reducing the cost of manual testing, standardizing the test process, and providing strong support for protecting the quality of household appliance products.

[0006] The present application provides a household appliance control panel test method based on PXI: The test system of the present method takes a PXI chassis as a hardware platform, and realizes safety testing of the test panel of household appliances by loading PXI modules with different functions and combining corresponding software programming. The system mainly includes the following parts: (1) Master control: a standard PXI chassis is selected as the system hardware carrier, and a PXI master module is installed in the chassis. The master module has powerful data processing and system control capabilities. The master module realizes unified control and coordinated management of the entire test system through high-speed data transmission and communication with other functional modules in the chassis through the PXI bus. The master module is programmed by writing a control program based on LabVIEW or other adaptive software development platform to realize automatic control of the test process and processing and analysis of test data.

[0007] (2) Signal acquisition: Key signal acquisition: PXI digital I / O module is configured for simulating user's operation on the test panel of household appliances, and the corresponding electrical signal is outputted by programming control of the digital I / O module to simulate the pressing and releasing action of different keys, so as to test the response function of the test panel to the key operation, for example, simulate the operation signal of various function keys, and detect whether the test panel correctly receives and executes the corresponding instruction.

[0008] Display signal acquisition: PXI data acquisition module is installed for acquiring the display signal of the test panel of household appliances. For the test panel with liquid crystal display or light emitting diode, the data acquisition module is connected to the display driving circuit through a suitable interface circuit to acquire the display data and control signal in real time, judge whether the display content is consistent with the operation instruction, test whether the display function is normal, and ensure that the test panel can accurately control the household appliance to execute the corresponding function in different operation modes.

[0009] (3) Software test platform: Based on the LabVIEW software development platform, the software program of the test system is designed and developed, and the software program includes a test flow control module, a data acquisition and processing module, a test result analysis and report generation module, the test flow control module automatically controls the function module to execute the test task according to the preset test scheme, the data acquisition and processing module processes and analyzes the collected test data in real time, and the test result analysis and report generation module judges whether the test result is qualified according to the processed data, and automatically generates a detailed test report, and the report content includes test items, test data, test results and fault information.

[0010] Advantages of the present application: 1. The present application adopts a standardized and modular hardware platform based on a PXI chassis, and uses an automatic test program written by LabVIEW to control PXI digital I / O module and oscilloscope card, accurately simulates user's key operation, display signal excitation and abnormal working condition input, simultaneously collects the response signal, display data and state feedback of the control panel, realizes the automatic test of the whole process, avoids the subjectivity and inconsistency of manual operation, greatly reduces the error introduced by human, and greatly improves the accuracy and reliability of the test result.

[0011] 2.The application realizes the automatic execution of each test under the unified and standard software process control by pre-compiling and loading the standardized verification test script for the control panel of a specific model, which strictly defines the complete flow, specific parameters and qualified criterion of a series of test items from the hardware self-check, power supply check, function test to safety protection verification, thereby ensuring the high consistency of the process and standard when different batches, different time and different operators perform the test, thereby effectively solving the test result difference problem caused by the arbitrary process of the traditional method. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 A schematic diagram of the test process of the control panel of the electric rice cooker is shown. Figure 2 A schematic diagram of the test process of the control panel of the electric fan is shown. DETAILED DESCRIPTION

[0013] In order to make the purpose, technical scheme and advantages of the embodiments of the application clearer, the technical scheme in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are some embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0014] Please refer to Figure 1 The application provides an embodiment 1: The embodiment is used for the off-line detection of the control panel of the intelligent electric rice cooker.

[0015] (1) When starting, the software first calls the NI-MAX to perform the hardware self-check, ensures the electrical integrity of the backplane and module, and then performs the power supply check. The program-controlled power supply module is set to output the alternating voltage (such as 220VAC, 50Hz). The test software first performs the static power consumption test: in the standby state of the panel, the PXI oscilloscope card synchronously samples the voltage and current waveforms output by the power supply module, and through the calculation of the true effective value and the instantaneous power integral, the standby power is obtained. Then, the voltage fluctuation test is performed: the software controls the power supply module to change at a fixed step within the ±15% range of the standard voltage (such as 187V to 253V). At each voltage point, the system automatically performs a simplified key response test (such as pressing the "power" key) once, to verify whether the panel can work normally and is not damaged under the abnormal power grid condition.

[0016] This step can capture the millisecond-level surge current peak when the panel is powered on for the first time or when the analog power grid instantaneously recovers, and determine whether it is within the safety specifications of devices such as fuses and rectifier bridges. This step can accurately measure standby power consumption as low as 0.1 W, with an accuracy of better than ±5 mW, ensuring that the product complies with energy-saving regulations (such as the ErP directive). And the automated traversal test replaces the tedious operation of manually adjusting the voltage regulator, with more and more accurate test data points, and the system can clearly record the minimum and maximum voltage thresholds for the panel to work normally and the consistency of key functions (such as display brightness and button response) within this range.

[0017] (2) Then the key / indicator light function verification is performed, the multi-output channel of the PXI digital I / O module is connected to each micro switch or touch sensing point of the panel through a special fixture, and a "key test sequence" is defined by the test script, for example: short press "function" key, long press "reservation" key for 3 seconds, and rapid consecutive press "+" key 5 times. For each simulated key action, the digital I / O module outputs the corresponding ground or power signal, and the system's measurement resources are automatically switched: For the key backlight LED, the anode voltage is measured by the PXI oscilloscope card to determine whether it is designed to light up or turn off when pressed.

[0018] For the buzzer, the PXI oscilloscope card or module with audio analysis function is used to collect the waveform of its driving pin to analyze whether the sound frequency and duration meet the design (for example, a short "ding" sound corresponds to a frequency of 2KHz and a duration of 100ms).

[0019] For the LCD display screen, its parallel or SPI / I2C bus is connected to capture its display buffer data using digital I / O modules or special communication cards, and after decoding, the string comparison is performed with the expected display content (such as "cooking" and "12:00").

[0020] This step can accurately measure the time delay from the simulation of the key signal to the panel MCU recognizing and producing an effective response (such as changing the display or emitting a beep). By analyzing the stability of this delay, the effectiveness of the key debouncing algorithm in the panel firmware can be indirectly verified. At the same time, by writing test scripts, all possible operation paths (normal and abnormal) of the user can be simulated, such as trying to set the reservation in the warm-up state to verify whether the panel gives the correct prompt or rejects illegal operations.

[0021] (3) Then the temperature calibration of the thermistor is performed. The electric rice cooker relies on a negative temperature coefficient (NTC) thermistor to sense the temperature of the inner pot. The test system uses a resistance simulator module to replace the real NTC sensor. According to the temperature-resistance characteristic table of the NTC, the software controls the resistance simulator to output a series of resistance values representing specific temperatures (such as room temperature 25℃ and boiling water 100℃). At the same time, the high-precision digitizer card measures the voltage division voltage of the NTC at the ADC pin of the MCU on the panel. The system compares the measured voltage value (corresponding to the ADC code value read by the MCU) with the standard resistance value (corresponding to the real temperature) set by the resistance simulator. Through curve fitting algorithms such as least squares, the calibration coefficients (such as offset and gain coefficient) of the panel temperature measurement circuit are automatically calculated and can be written into the memory of the panel MCU to complete online calibration.

[0022] Then the control logic verification is performed. First, the resistance value is set to simulate the temperature changing from low to high, and the system synchronously monitors the output signal of the panel to the heater (controlled by a relay or a thyristor) to verify whether it acts according to the preset logic at specific "temperature points" (corresponding to specific resistance values), such as stopping full-power heating and switching to holding power when reaching the "rice cooking" set temperature.

[0023] This step requires equipment such as a constant-temperature oil tank when using traditional calibration methods, and takes tens of minutes. This method can complete automatic scanning and calibration of multiple temperature points within seconds, with a temperature calibration accuracy of ±0.5℃ or less, greatly improving efficiency.

[0024] (4) Then the resistance and power of the heating element are measured. First, the programmable switch matrix is used to connect the heater output terminals on the panel to the PXI digital multimeter module. The cold DC resistance of the heating wire is measured at low current to determine whether it is open circuit, short circuit or resistance out of tolerance. When the panel actually drives the heater, the PXI power analysis module is used to measure the actual AC power and compare it with the rated power and the panel display power.

[0025] (5) Then the path resistance of the relay is checked. Through the switch matrix and the PXI digital multimeter module, the contact resistance and open insulation resistance between the main contacts of the relay are measured in the states of relay attraction and disconnection to determine the performance at the end of the relay life and whether there is a risk of welding and sticking.

[0026] (6) Finally, simulate the fault to test the protection triggering function. The software controls the resistance simulator to simulate NTC open circuit (extremely high resistance) or short circuit (extremely low resistance), and controls the power module to simulate overvoltage, while monitoring whether the panel enters the protection state (cuts off the heating output and displays the error code "E1") within the specified time (such as 2 seconds).

[0027] (7) After the whole test is completed, if the detection is qualified, a "self-check qualified" report is generated, and if not, the unqualified items are generated and the log is saved.

[0028] Referring to Figure 2 The present application provides an embodiment 2: This embodiment tests the fan panel with multi-speed regulation, timing and head control.

[0029] The power supply check, button / indicator light function verification and relay path resistance check of this embodiment are the same as those of embodiment 1, and this embodiment will not be repeated.

[0030] (1) After the power supply check, button / indicator light function verification, the calibration test of the speed sensor is performed, first, the system uses a PXI analog input module as a high-precision signal acquisition front end, connected to the speed sensor (Hall sensor / optical encoder) output signal line of the fan. During testing, the fan impeller is driven by an external driving device to rotate at multiple known and stable speed points (such as 200 RPM, 600 RPM, 1200 RPM). At each stable speed point, the PXI analog input module collects the pulse waveform output by the sensor at a high sampling rate, and accurately calculates the pulse frequency or period through the built-in timing / counting function or software algorithm. The system associates the collected original signal parameters (average voltage, frequency value) with the corresponding known standard speed value, and generates a "sensor signal characteristic value-actual speed" calibration curve or conversion formula through curve fitting algorithms such as least squares method. This calibration data can be used to verify the linearity of the sensor itself, or directly written into the panel control program as a parameter to realize software calibration of speed measurement, thereby eliminating the measurement error caused by the discreteness of the sensor.

[0031] (2) After the relay path resistance check is completed, PWM driving and power measurement tests are performed. The test system first simulates the panel controller to output multi-gear PWM (pulse width modulation) driving signals through a PXI digital I / O module or a PWM output module, with a duty cycle covering each node (such as 30%, 50%, 70%, etc.) from 0% (stop) to 100% (full speed). The PWM signal is applied to the motor driver input of the fan, and at the same time, the PXI power analysis module of the system collects the working voltage and current waveforms of the motor drive circuit in real time. The special computing unit integrated in the module or the upper computer software calculates the instantaneous power, average power, power factor, and harmonic components according to the synchronously sampled instantaneous voltage and current values, and then the test software automatically compares the average power and steady-state current data measured at each gear PWM with the allowable range specified in the product design specification. This process not only verifies whether the panel PWM output can correctly control the motor to achieve the expected power level, but also accurately quantifies the input power of the entire machine at different wind speeds, checks whether it meets the energy efficiency standard requirements, and finds out whether there are problems such as abnormal drive circuit efficiency or poor load matching.

[0032] (3) After the entire test is completed, if the detection is qualified, a "self-check qualified" report is generated, and if it is not qualified, the unqualified items are generated and the log is saved.

[0033] The present application provides a comparative example: Traditional household appliance control panel testing mainly relies on manual operation. A typical test station may include: a manual voltage regulator, a digital multimeter, a simple oscilloscope, and a manual test box with physical buttons and indicator lights.

[0034] The tester needs to manually adjust the voltage regulator to the specified voltage according to the paper work instruction, then measure the voltage and resistance of each test point with the multimeter pen, then press the buttons on the test box with his hand, observe the indicator lights or LCD display on the panel, listen to the buzzer sound with his ears, connect the oscilloscope probe to the key point, manually adjust the time base and amplitude, observe the waveform shape, estimate the parameters, and finally record the test results (check or fill in the values) on the paper table.

[0035] (1) The comparative example detects the same type of control panel on a production line of 1 million electric rice cookers per year to observe the performance of the two methods. The detection items of the comparative example include power adaptability (3 voltage points), all button functions (12 keys), LED indicator lights (6), LCD display (5 interfaces), buzzer, temperature sensor calibration (5 temperature points), heating element resistance, working power, relay contact resistance, and NTC fault simulation protection.

[0036] Comparison dimension Traditional method The present application Single board test total time consumption About 300 ± 50 seconds About 45 ± 2 seconds Test labor intensity High Low Result determination subjectivity High None Data record and trace Paper record, easy to lose, alter, difficult to query and analyze. Electronic data record, automatically generate report, database storage, one-key trace. Complex project test ability Temperature calibration cannot be performed online; protection test has safety risk and is not comprehensive High-precision online automatic calibration can be completed; fault injection test can be safely and comprehensively automatically executed From the above table, the conventional manual test method takes about 300 seconds for single board test, while the present application greatly shortens the test time to about 45 seconds with little fluctuation, greatly improving the detection efficiency. At the same time, the automated method eliminates the high labor intensity, high subjectivity of results and difficulty in tracing data caused by relying on manual operation, sensory judgment and paper records in the traditional way, and builds a traceable test process.

[0037] (2) Further long-term test is carried out to verify the long-term operation quality and operation cost of the present application.

[0038] Comparison dimension Traditional manual test method The PXI automatic test method of the present application First pass yield (FPY) Simulation value: 98.2% Simulation value: 99.5% Misjudgment rate High Extremely low Test personnel requirement Each line needs to be configured with 2-3 full-time test personnel, and 6-9 people are needed for three shifts Each line only needs one operator to be responsible for feeding and discharging, three shifts need 3 people, and the test is automatically completed by the device Test data value Almost no value High value From the above table, the conventional manual test method shows a low first-pass rate (98.2%), a high misjudgment rate, a high labor demand (6-9 people are needed for each line) and almost no value of test data in the simulation of 100,000 pieces of production, while the first-pass rate of the present application is 99.5% and the misjudgment rate is extremely low. The method reduces the demand for production line test personnel to 3 people per line through automation, greatly reducing the direct labor cost, and the test data generated can become a high-value asset for quality traceability and help process improvement.

[0039] The above is only a preferred embodiment of the present application, and does not limit the present application in other forms. Any skilled person in the art can modify or reform the above disclosed technical content into equivalent embodiments applied to other fields, but any simple modification, equivalent change and reform made according to the technical essence of the present application to the above embodiments without departing from the technical solution content of the present application still falls within the protection scope of the present application.

Claims

1. A PXI-based method of testing a control panel of a household appliance, characterized by, The method is executed by establishing a test system with a PXI chassis as a hardware platform, the system comprising a PXI host module, a PXI digital I / O module and a PXI oscilloscope card installed in the PXI chassis, and the method comprising the following steps: S1, through a test control program developed based on LabVIEW, calling a hardware management interface to perform self-checking on the electrical connection integrity and functional state of the PXI chassis, the PXI host module, the PXI digital I / O module and the PXI oscilloscope card; S2, the test control program loads a verification test script preset for a specific household appliance control panel model, the verification test script defining a series of test items, test parameters and qualification criteria; S3, the test control program controls the PXI digital I / O module to output simulated key operation electrical signals to the key interface of the control panel under test according to the timing requirements of the verification test script, and simultaneously collects the response signals of the control panel under test under simulated key operation through the input channel of the PXI digital I / O module or the PXI oscilloscope card; S4, the test control program controls the PXI oscilloscope card to collect the display data and control signals of the display driving circuit of the control panel under test after receiving the test instructions, and compares the collected display data with the expected display content in the verification test script; S5, the test control program simulates user operation sequences and abnormal working conditions through the cooperative work of the PXI digital I / O module and the PXI oscilloscope card, and synchronously monitors the output control signals and state feedback signals of the control panel under test to verify the correctness of the control logic and the triggering conditions and actions of the safety protection function; S6, the test control program performs real-time processing and analysis on all the response signals, display data and state signals collected in steps S3-S5, judges whether each test passes or not according to the qualification criteria in the verification test script, and generates a test report containing test items, test data, comparison results, final conclusion and fault details.

2. The PXI-based home appliance control panel test method of claim 1, wherein: In step S1, calling the hardware management interface specifically refers to calling the configuration and diagnosis interface provided by the NI-MAX software to perform identification and basic function diagnosis on the PXI backplane bus, the module identification and the firmware version.

3. The PXI-based home appliance control panel test method of claim 2, wherein: The verification test script further comprises a power supply check item, after step S2, the test control program controls a program-controlled power supply module connected with the PXI chassis to apply a rated voltage to the control panel under test, and monitors the voltage, current waveform and steady-state value during the power-on process using the PXI oscilloscope card or a dedicated PXI digital multimeter module to determine whether the power supply circuit is normal.

4. The PXI-based home appliance control panel test method of claim 3, wherein, The method further comprises a power measurement step: when the control panel under test drives its load, the working voltage and current of the load are measured in real time through the PXI oscilloscope card or a dedicated PXI power analysis module, the real-time power is calculated, and compared with the rated power range set in the verification test script.

5. The PXI-based home appliance control panel test method according to claim 4, characterized in that: In step S3, the simulated key operation electrical signals include level change sequences simulating short press, long press, continuous press and combined key operation.

6. The PXI-based home appliance control panel test method according to claim 5, characterized in that: In step S3, the collected response signals include the state change signals of the key backlight, the key triggered buzzer prompt tone signals or the key event data packets fed back through the communication interface of the control panel under test.

7. The PXI-based home appliance control panel testing method of claim 6, wherein: In step S4, the signals of the data line and control line of the driving chip of the liquid crystal display screen are collected to restore the display content, and the driving level of the anode or cathode of the LED indicator light is collected to determine whether the on, off or flickering state is correct.

8. The PXI-based home appliance control panel test method according to claim 7, wherein, In step S5, the simulation of abnormal working conditions includes simulating the open circuit or short circuit fault signals of the sensor through the PXI digital I / O module, or simulating the overvoltage or undervoltage conditions of the input voltage through the program-controlled power module, and the monitored output control signals include the control signals of the driving relays, thyristors or stepping motors of the control panel under test.

9. The PXI-based home appliance control panel test method according to claim 8, wherein, The method further includes a path resistance detection step: in the test process or after the test is completed, a BIRST compatible programmable relay matrix is controlled by the test control program to switch to the connection path between different electrical nodes on the control panel under test, and the PXI digital multimeter module in the PXI chassis or the built-in measurement function of the switch matrix is used to measure and record the path resistance, which is used to determine the contact state of the contact, the integrity of the line connection and whether there is a virtual welding.

10. The PXI-based home appliance control panel testing method of claim 9, wherein: In step S6, the standardized test report is saved in the form of an electronic document, and the test time, the serial number of the panel under test, the test system identification and the operator information are recorded, and the detailed data of the unqualified items and the fault log are stored.

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