Digital ANC automatic simulation test methodTechnical Field
The invention relates to the technical field of active noise reduction earphones, in particular to a digital ANC automatic simulation test method.
Background
The existing noise reduction earphones on the market are mainly classified into analog noise reduction and digital noise reduction, the existing mainstream design process is mainly the basic simulation of earphones before mass production, a set of fixed filter parameters is obtained, the frequency response phase of a target curve is greatly different due to the difference of mass production materials during mass production, and two methods for earphone noise reduction are adopted, namely active noise reduction and passive noise reduction. The active noise reduction function is to generate reverse sound waves equal to external noise through a noise reduction system to neutralize the noise, so that the noise reduction effect is realized. The active noise reduction earphone is provided with a noise reduction circuit which is in counter balance with external noise, most of the active noise reduction earphone adopts a head-wearing design with a larger volume, structures such as earplug cotton and an earphone shell can be used for blocking the external noise, a first round of sound insulation is carried out, and meanwhile, the active noise reduction circuit and a power supply are arranged in order to have sufficient space. The passive noise reduction earphone mainly forms a closed space by surrounding ears, or adopts sound insulation materials such as silica gel earplugs and the like to block outside noise. Because the noise is not processed by the noise reduction circuit chip, the noise can only be blocked from high-frequency noise generally, and the noise reduction effect on low-frequency noise is not obvious. Three noise reduction measures, namely noise reduction at the sound source, noise reduction during propagation, and noise reduction at the human ear, which are generally adopted for noise reduction, are passive and passive.
The test system on the market can only adjust the gain of the filter to achieve the best noise reduction effect among different earphones, the test scheme can only compensate the gain, and the material difference can only affect the frequency response and the phase, so that the test system can not effectively adjust each earphone to achieve the best level, but also can lead to the straight rise of the reject ratio, and bring the direct loss of the benefit to a production company and bring the unpredictable influence on the consistency and the stability of the product.
Disclosure of Invention
The invention aims to solve the problems that a test system cannot effectively adjust each earphone to the best level, the reject ratio is increased linearly, the direct loss of benefits is brought to a production company, and unpredictable influence is brought to the consistency and stability of a product.
In order to achieve the purpose, the invention adopts the following technical scheme:
the digital ANC automatic simulation test method comprises the following steps:
s1: manually performing ANC on a new earphone by a technician on the earphone with the characteristic production line, and storing test data in a database named by a project name;
s2: placing the earphone to be tested into a testing frame by an employee, and testing the basic conditions of the earphone;
s3: sending the test data to a test system for analysis and calculating a target curve;
s4: adjusting the filter to best fit the curve of the filter to the target curve;
s5: the calculated filter curve is written to the headphone and tested.
Preferably, in S5, the test content is fully automatic, and only the headset needs to be placed in the test rack, the test is clicked on the computer and the product two-dimensional code is scanned, and after the headset test is completed, the test result is popped up and all data in the test are placed in the separate folder generated by the product two-dimensional code.
Preferably, the test system comprises test software, a simulated noise source and a simulated ear receiver.
Preferably, in S2, the basic conditions include a noise standard, a microphone, and a speaker.
Preferably, a scanner and a controller are arranged in the test frame, when in test, the controller controls the scanner to work, the scanner scans the two-dimensional code on the test product and transmits the scanning result to a computer, and the scanning angle of the scanner can be adjusted.
Preferably, the simulation noise source is a simulation noise device, the simulation noise device slides on a track, during testing, the simulation noise device is manually moved, the distance between the simulation noise device and a tested earphone is controlled, an infrared distance meter is installed on the simulation noise device and connected with a display, the distance between the simulation noise device and the tested earphone is measured through the infrared distance meter, the measured data are displayed on the display, during testing of the earphone, the distance data displayed on the display are recorded, the measured data are classified according to different distance data, an electric push rod is controlled by the controller, the controller is a programmable PLC (programmable logic controller), meanwhile, the simulation noise device is controlled through the controller, the decibel of the simulation noise device is changed, and the decibel of the simulation noise device is also displayed on the display.
Compared with the prior art, the invention has the advantages that:
(1) the scheme calculates an ideal target curve and phase of each earphone through simple test, calculates a filter most suitable for the earphone through a system automatic algorithm, and automatically customizes the filter for each earphone so as to enable the filter to reach the requirement of a designer all the time;
(2) the scheme can adjust the frequency response and the phase of the filter, and compared with a system which can only adjust the sensitivity, the yield of the product is greatly improved, the cost is saved, and the mass production of the ANC earphone is no longer the product with the lowest through rate in the industry.
Detailed Description
The technical solutions in the embodiments are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments, but not all embodiments.
The digital ANC automatic simulation test method comprises the following steps:
s1: manually performing ANC on a new earphone by a technician on the earphone with the characteristic production line, and storing test data in a database named by a project name;
s2: the method comprises the following steps that a worker puts a tested earphone into a test frame, basic conditions of the earphone are tested, the basic conditions comprise a noise standard, a microphone and a loudspeaker, a scanner and a controller are arranged in the test frame, the controller controls the scanner to work during testing, the scanner scans a two-dimensional code on a tested product and transmits a scanning result to a computer, and the scanning angle of the scanner can be adjusted;
s3: the testing system comprises testing software, a simulation noise source and a simulation ear receiver, wherein the simulation noise source is a simulation noise device, the simulation noise device slides on a track, the simulation noise device is manually moved during testing, the distance between the simulation noise device and a tested earphone is controlled, an infrared distance meter is installed on the simulation noise device and connected with a display, the distance between the simulation noise device and the tested earphone is measured through the infrared distance meter, the measured data are displayed on the display, the distance data displayed on the display are recorded during earphone testing, the measured data are classified according to different distance data, an electric push rod is controlled by the controller, the controller is a programmable PLC (programmable logic controller), and meanwhile, the noise device is controlled by the controller to change the decibel of the simulation noise device, decibels of the analog noise device are also displayed on the display;
s4: adjusting the filter to best fit the curve of the filter to the target curve;
s5: and writing the calculated filter curve into the earphone and testing, wherein the testing content is full-automatic, the earphone is only required to be placed on a testing frame, the test is clicked on a computer and the product two-dimensional code is scanned, after the earphone test is finished, a test result can be popped up, and all data in the test can be placed into an independent folder generated by the product two-dimensional code. The scheme calculates an ideal target curve and phase of each earphone through simple test, calculates a filter most suitable for the earphone through a system automatic algorithm, and automatically customizes the filter for each earphone so as to enable the filter to reach the requirement of a designer all the time; the scheme can adjust the frequency response and the phase of the filter, and compared with a system which can only adjust the sensitivity, the yield of the product is greatly improved, the cost is saved, and the mass production of the ANC earphone is no longer the product with the lowest through rate in the industry.
The above description is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered as the technical solutions and the inventive concepts of the present invention in the technical scope of the present invention.