A method, device and storage medium for calibrating the position of an ultrasonic transducer

Abstract

The present specification discloses a method, device and storage medium for calibrating the position of an ultrasonic transducer, controlling the transducer to be calibrated to transmit an ultrasonic signal, and determining the number of sampling moments M at which the ultrasonic signal is sampled according to the signal value of the other transducer at each sampling moment for each other transducer, and determining the number of sampling moments M at which the ultrasonic signal is sampled for the kth sampling moment t k , according to the sampling time t k+1 To sampling time t k+M The average power of the signal value between the first sampling time t1 and the sampling time t k The ratio of the average power of the signal values ​​between the two determines the sampling time t k The power jump ratio. According to the power jump ratio at each sampling moment, the wave arrival time of the other transducer is determined, and the actual position of the transducer to be calibrated is calibrated by the wave arrival time of each other transducer. By calculating the power jump ratio, the wave arrival time of other transducers can be accurately determined, thereby achieving accurate position calibration of the transducer to be calibrated.

Description

Technical Field

[0001] The present invention relates to the field of transducer position calibration, and in particular to a method, device and storage medium for calibrating the position of an ultrasonic transducer. Background Art

[0002] Ultrasonic transducer array is a device for ultrasonic emission and ultrasonic echo reception, which is composed of multiple transducers arranged in a certain shape. In the process of manufacturing ultrasonic transducer array, multiple transducers need to be assembled, and the assembly process inevitably causes position errors of the transducers, so that the actual position of each transducer in the finished ultrasonic transducer array does not match the ideal position during manufacturing.

[0003] In medical ultrasound imaging, the position error of the transducer may cause artifacts and reduced resolution in the ultrasound image, which is not conducive to doctors making diagnoses based on the ultrasound image. Therefore, this specification provides a method for calibrating the position of an ultrasound transducer. Summary of the invention

[0004] The present specification provides a method, device, storage medium and electronic device for calibrating the position of an ultrasonic transducer to at least partially solve the above-mentioned problems existing in the prior art.

[0005] This manual adopts the following technical solutions:

[0006] This specification provides a method for calibrating the position of an ultrasonic transducer, including:

[0007] Determining a transducer to be calibrated and other transducers in the transducer array;

[0008] Controlling the transducer to be calibrated to transmit an ultrasonic signal, and each of the other transducers to receive the ultrasonic signal;

[0009] For each other transducer, sampling the ultrasonic signal received by the other transducer, and determining the signal value of the other transducer at each sampling time;

[0010] Determine the number M of sampling moments at which the ultrasonic signal is sampled according to the signal value of the other transducer at each sampling moment;

[0011] For the kth sampling time t k , according to the sampling time t k+1 To sampling time t k+M The average power of the signal value between the first sampling time t1 and the sampling time t k The ratio of the average power of the signal values ​​between the two determines the sampling time t k Power jump ratio;

[0012] Determining the arrival time of the other transducer according to the power jump ratio at each sampling moment;

[0013] The actual position of the transducer to be calibrated is calibrated according to the estimated position of the transducer to be calibrated, the actual positions of the other transducers, the speed of sound and the arrival time of the other transducers.

[0014] Optionally, determining the number M of sampling moments at which the ultrasonic signal is sampled according to the signal value of the other transducer at each sampling moment specifically includes:

[0015] Determining the length of time that the other transducer receives the ultrasonic signal according to the signal value of the other transducer at each sampling moment;

[0016] A sampling period is determined, and the number M of sampling moments at which the ultrasonic signal is sampled is determined according to a ratio of a time length during which the other transducer receives the ultrasonic signal to the sampling period.

[0017] Optionally, determining the arrival time of the other transducer according to the power jump ratio at each sampling moment specifically includes:

[0018] Among the power ramp ratios at the sampling moments, determining the maximum power ramp ratio;

[0019] Determine the order of the sampling moments corresponding to the maximum power ramp ratio among the sampling moments;

[0020] A sampling period is determined, and the product of the order and the sampling period is taken as the arrival time of the other transducer.

[0021] Optionally, calibrating the actual position of the transducer to be calibrated according to the estimated position of the transducer to be calibrated, the actual positions of the other transducers, the speed of sound and the arrival time of the other transducers, specifically includes:

[0022] For each other transducer, determining the distance between the other transducer and the transducer to be calibrated according to the product of the wave arrival time of the other transducer and the sound velocity;

[0023] According to the actual position of the other transducer, the estimated position of the transducer to be calibrated and the distance, determine the equation of a circle with the transducer to be calibrated as the center and the distance as the radius, as the original equation corresponding to the other transducer;

[0024] Determine the target equation group according to the original equations corresponding to each other transducer;

[0025] The target equation group is solved by weighted iterative least square method to obtain the actual position of the transducer to be calibrated.

[0026] Optionally, the target equation group is determined according to the original equations corresponding to each other transducer, specifically including:

[0027] In the primitive equations corresponding to the other transducers, each pair of equations consisting of two different primitive equations is determined;

[0028] For each equation pair, subtract the two original equations contained in the equation pair to obtain the target equation of the equation pair;

[0029] The target equations of each pair of equations are combined to obtain the target equation group.

[0030] Optionally, the sound speed is an estimated value, and the solution of the target equation group is divided into multiple alternating iteration cycles;

[0031] Calibrate the actual position of the transducer to be calibrated according to the estimated position of the transducer to be calibrated, the actual position of each of the other transducers, the speed of sound, and the wave arrival time of each of the other transducers, specifically including:

[0032] For each alternating iteration cycle, determine the target equation group of the alternating iteration cycle according to the estimated position of the transducer to be calibrated iteratively updated in the previous alternating iteration cycle, the actual position of each of the other transducers, the estimated sound velocity updated in the previous alternating iteration cycle, and the wave arrival time of each of the other transducers;

[0033] Solving the target equation group of the alternating iteration period by weighted iterative least square method to obtain the estimated position of the transducer to be calibrated that is iteratively updated in the alternating iteration period;

[0034] Determine whether the alternating iteration cycle reaches the second iteration stop condition;

[0035] If so, the estimated position of the transducer to be calibrated updated in the alternating iteration period is used as the actual position of the transducer to be calibrated;

[0036] If not, then for each other transducer, according to the actual position of the other transducer and the estimated position of the transducer to be calibrated iteratively updated in the alternating iteration period, determine the distance between the other transducer and the transducer to be calibrated in the alternating iteration period; use the ratio of the distance between the other transducer and the transducer to be calibrated in the alternating iteration period to the wave arrival time of the other transducer as the estimated sound speed corresponding to the other transducer in the alternating iteration period; according to the estimated sound speed corresponding to each other transducer in the alternating iteration period, determine the estimated sound speed updated in the alternating iteration period, and continue the iteration process of the next alternating iteration period until the second iteration stop condition is reached.

[0037] Optionally, determining the estimated sound speed updated in the alternating iterative period according to the estimated sound speed corresponding to each other transducer in the alternating iterative period specifically includes:

[0038] Determine the median of the estimated sound speeds corresponding to each of the other transducers in the alternating iteration cycle;

[0039] The median is used as the estimated sound speed updated in the alternating iteration cycle.

[0040] This specification provides a position calibration device for an ultrasonic transducer, the device comprising:

[0041] A calibration target determination module determines the transducer to be calibrated and other transducers in the transducer array;

[0042] An ultrasonic transmitting module controls the transducer to be calibrated to transmit an ultrasonic signal, and each of the other transducers receives the ultrasonic signal;

[0043] A sampling module, for each other transducer, samples the ultrasonic signal received by the other transducer, and determines the signal value of the other transducer at each sampling time;

[0044] A sampling moment number determination module, which determines the number M of sampling moments at which the ultrasonic signal is sampled according to the signal value of the other transducer at each sampling moment;

[0045] The power ramp ratio determination module is used for the kth sampling time t k , according to the sampling time t k+1 To sampling time t k+M The average power of the signal value between the first sampling time t1 and the sampling time t k The ratio of the average power of the signal values ​​between the two determines the sampling time t k Power jump ratio;

[0046] A wave arrival time determination module, which determines the wave arrival time of the other transducer according to the power jump ratio at each sampling moment;

[0047] The calibration module calibrates the actual position of the transducer to be calibrated according to the estimated position of the transducer to be calibrated, the actual positions of the other transducers, the speed of sound and the arrival time of the other transducers.

[0048] This specification provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the above-mentioned ultrasonic transducer position calibration method is implemented.

[0049] The present specification provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned ultrasonic transducer position calibration method when executing the program.

[0050] At least one of the above technical solutions adopted in this specification can achieve the following beneficial effects:

[0051] In the ultrasonic transducer position calibration method provided in this specification, the transducer to be calibrated is controlled to transmit an ultrasonic signal, and each other transducer receives the ultrasonic signal. For each other transducer, the ultrasonic signal received by the other transducer is sampled, and the signal value of the other transducer at each sampling time is determined. According to the signal value of the other transducer at each sampling time, the number of sampling times M at which the ultrasonic signal is sampled is determined, and for the kth sampling time t k , according to the sampling time t k+1 To sampling time t k+M The average power of the signal value between the first sampling time t1 and the sampling time t k The ratio of the average power of the signal values ​​between the two determines the sampling time t k According to the power jump ratio at each sampling moment, the wave arrival time of the other transducer is determined, and the actual position of the transducer to be calibrated is calibrated by the wave arrival time of each other transducer.

[0052] In this method, when the ultrasonic signal reaches other transducers, the signal values ​​of other transducers will change significantly, and the energy of the received ultrasonic signal is concentrated in M ​​sampling moments. The power jump ratio represents the average power difference of the signal value in two consecutive time periods. At the sampling moment when the ultrasonic signal is received, the average power of the subsequent M sampling moments will increase significantly compared with the average power of the previous sampling moments. Therefore, by calculating the power jump ratio at each sampling moment, the wave arrival time of other transducers can be accurately determined, thereby achieving accurate position calibration of the transducer to be calibrated. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The drawings described herein are used to provide a further understanding of this specification and constitute a part of this specification. The illustrative embodiments and descriptions of this specification are used to explain this specification and do not constitute an improper limitation on this specification. In the drawings:

[0054] Figure 1 A schematic diagram of a flow chart of a method for calibrating the position of an ultrasonic transducer in this specification;

[0055] Figure 2 Two sets of signal sampling data provided in the embodiments of this specification;

[0056] Figure 3 A schematic diagram of a primitive equation construction provided in an embodiment of this specification;

[0057] Figure 4 An iterative hierarchical diagram provided in an embodiment of this specification;

[0058] Figure 5 A schematic diagram of a position calibration device for an ultrasonic transducer provided in this specification;

[0059] Figure 6 The corresponding Figure 1 Schematic diagram of electronic equipment. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solutions and advantages of this specification more clear, the technical solutions of this specification will be clearly and completely described below in combination with the specific embodiments of this specification and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0061] The transducer array is composed of multiple transducers assembled in a certain shape, and the assembly process will produce position errors. At present, large ultrasonic transducer arrays with complex spatial structures, such as arc transducer arrays, annular transducer arrays, hemispherical transducer arrays, etc., are increasingly widely used. Compared with ordinary planar transducer arrays, large ultrasonic transducers have better spatial resolution when receiving ultrasonic signals and are more suitable for three-dimensional ultrasonic imaging.

[0062] The manufacturing process of large ultrasonic transducers is more complicated because the array is curved. During manufacturing, usually individual transducers are first spliced ​​into smaller array units, and then multiple array units are spliced ​​into a curved shape. The positional errors that may occur during the manufacturing process of large ultrasonic transducer arrays are more serious.

[0063] During ultrasound imaging, the accuracy of the position of each transducer in the transducer array has an important impact on the imaging quality. Therefore, precise calibration of the position of each transducer in the transducer array can reduce ultrasound imaging artifacts and provide doctors with more accurate diagnostic basis.

[0064] The technical solutions provided by the embodiments of this specification are described in detail below in conjunction with the accompanying drawings.

[0065] Figure 1 The following is a flow chart of a method for calibrating the position of an ultrasonic transducer in this specification, which specifically includes the following steps:

[0066] S100: Determine a transducer to be calibrated and other transducers in a transducer array.

[0067] All steps in the ultrasonic transducer position calibration method provided in this specification can be implemented by any electronic device with computing functions, such as a terminal, a server, etc. For the convenience of description, the ultrasonic transducer position calibration method provided in this specification is described below with the server as the execution subject.

[0068] The ultrasonic transducer position calibration method of the present specification can calibrate the position of a transducer with inaccurate position in an ultrasonic array, can calibrate the position of multiple transducers with inaccurate position in an ultrasonic array, and can also calibrate the position of all transducers included in the ultrasonic array.

[0069] The method of position calibration for multiple transducers is similar to the method of position calibration for one transducer. The position calibration for one transducer is first taken as an example to illustrate the position calibration method of the ultrasonic transducer of this specification.

[0070] Before the calibration process begins, the positions of each transducer in the transducer array are all estimated positions. The server determines the transducer that needs to be calibrated in the transducer array as the transducer to be calibrated, and uses the estimated positions of other transducers in the transducer array other than the transducer to be calibrated as fixed values, that is, the estimated positions of other transducers are used as actual positions to calibrate the transducer to be calibrated.

[0071] The estimated position of each transducer to be calibrated in the transducer array can be an ideal position specified when the transducer array is designed, or a randomly determined position. In the subsequent iterative solution process, the estimated position of each transducer to be calibrated will be gradually optimized to the actual position.

[0072] S102: Control the transducer to be calibrated to transmit an ultrasonic signal, and each of the other transducers to receive the ultrasonic signal.

[0073] The server controls the transducer to be calibrated to transmit an ultrasonic signal, and enables other transducers to receive the ultrasonic signal.

[0074] So that in the subsequent steps, the time when each other transducer receives the ultrasonic signal is calculated, and the distance between each other transducer and the transducer to be calibrated is determined according to the sound speed of the ultrasonic signal through the principle of acoustic wave ranging, thereby determining the actual position of the transducer to be calibrated.

[0075] S104: For each other transducer, sampling the ultrasonic signal received by the other transducer, and determining the signal value of the other transducer at each sampling moment.

[0076] For each other transducer, the server samples the ultrasonic signal received by the other transducer according to a preset sampling period starting from the moment when the transducer to be calibrated transmits the ultrasonic signal, and obtains the signal value of the other transducer at each sampling moment.

[0077] The server takes the moment when the transducer to be calibrated transmits the ultrasonic signal as time zero, and samples the signal values ​​of the other transducers at each sampling moment to calculate the corresponding arrival time of the other transducers, that is, the time when the ultrasonic signal emitted by the transducer to be calibrated reaches the other transducers.

[0078] S106: Determine the number M of sampling moments at which the ultrasonic signal is sampled according to the signal value of the other transducer at each sampling moment.

[0079] When the ultrasonic signal emitted by the transducer to be calibrated reaches the other transducer, the value of the sampled signal will increase. The period from when the ultrasonic signal reaches the other transducer until the other transducer cannot receive the ultrasonic signal is the length of time that the other transducer receives the ultrasonic signal. The ultrasonic signal sampled is a discrete signal, and the time length is a multiple of the sampling period.

[0080] Specifically, the server determines the time length that the other transducer receives the ultrasonic signal according to the signal value of the other transducer at each sampling time, and then determines the number M of sampling times at which the ultrasonic signal is sampled according to the ratio of the time length that the other transducer receives the ultrasonic signal to the sampling period.

[0081] The length of time that the other transducer receives the ultrasonic signal can be determined in a variety of ways. For example, the server can determine the waveform corresponding to the other transducer based on the signal value at each sampling moment, and the user can manually determine the length of time by observing the waveform. Alternatively, the server determines the length of time based on a preset signal threshold and a number of consecutive sampling moments when the signal value is greater than the signal threshold.

[0082] In another embodiment, the server may also determine the number M of sampling moments at which the ultrasonic signal is sampled according to the difference in sampling order corresponding to the first sampling moment and the last sampling moment at which the ultrasonic signal is received.

[0083] S108: For the kth sampling time t k , according to the sampling time t k+1 To sampling time t k+M The average power of the signal value between the first sampling time t1 and the sampling time t k The ratio of the average power of the signal values ​​between the two determines the sampling time t k Power boost ratio.

[0084] In sampling the ultrasonic signal received by the other transducer, the signal value obtained at the sampling time within the time length when the other transducer receives the ultrasonic signal is usually greater than the signal value obtained at the sampling time not within the time length when the other transducer receives the ultrasonic signal.

[0085] The M signal values ​​sampled at the sampling time within the time length when the other transducer receives the ultrasonic signal correspond to higher energy, and accordingly, the average power of the M signal values ​​sampled at the sampling time within the time length when the other transducer receives the ultrasonic signal is higher. Based on this feature, the sampling time when the other transducer starts to receive the ultrasonic signal can be determined to determine the wave arrival time of the other transducer.

[0086] In this specification, the server takes the kth sampling time t k , according to the sampling time t k+1 To sampling time t k+M The average power of the signal value between the first sampling time t1 and the sampling time t k The ratio of the average power of the signal values ​​between the two determines the sampling time t k Power boost ratio.

[0087] Specifically, the power ramp ratio can be determined according to the following formula:

[0088]

[0089] in, Indicates The other transducers are in The power jump ratio at the sampling moment is Indicates The other transducers are sampled from the first sampling moment to the The energy at each sampling moment, Indicates the time from the first sampling moment to the Between sampling times The average power at the sampling time, Indicates The other transducers are from Sampling time to The energy at each sampling moment, Indicates Sampling time to Between sampling times The average power at each sampling moment.

[0090] S110: Determine the arrival time of the other transducer according to the power jump ratio at each sampling moment.

[0091] For each sampling moment, the power jump ratio reflects the difference between the average power of the M sampling moments after the sampling moment and the average power of each sampling moment before the sampling moment. This is because the signal value of the sampled ultrasonic signal is larger in the time length corresponding to the M sampling moments after the other transducer receives the ultrasonic signal, that is, the energy of the ultrasonic signal received by the other transducer is concentrated in the time length corresponding to the M sampling moments after the other transducer receives the ultrasonic signal.

[0092] For the sampling moment when the other transducer starts to receive the ultrasonic signal, in the absence of noise, the energy value of each sampling moment before the sampling moment is 0, and the energy of the ultrasonic signal received by the other transducer is concentrated in the M consecutive sampling moments starting from the sampling moment. Then the difference between the average power of the M sampling moments after the sampling moment and the sampling moments before the sampling moment is the largest, that is, the sampling moment when the ultrasonic signal starts to be received has the largest power jump ratio.

[0093] Even in the presence of noise, at each sampling moment before the ultrasonic signal received by the other transducer, the signal value corresponding to the noise signal will be sampled, but since the signal value of these noise signals has a smaller amplitude than that of the ultrasonic signal, the energy of the ultrasonic signal received by the other transducer will still be concentrated in the time period of M sampling moments included in the signal duration. According to the above principle, the sampling moment when the ultrasonic signal begins to be received still has the largest power jump ratio.

[0094] Therefore, for each other transducer, the server determines the maximum power ramp ratio among the power ramp ratios at each sampling moment, and then determines the order of the sampling moments corresponding to the maximum power ramp ratio among the sampling moments, and uses the product of the order and the sampling period as the wave arrival time of the other transducer.

[0095] After the server determines the sampling moment corresponding to the maximum power jump ratio, it determines which sampling moment the sampling moment is, and then determines the time when the other transducers receive the ultrasonic signal, that is, the arrival time, based on the product of the order of the sampling moment and the sampling period.

[0096] Specifically, the wave arrival time can be determined according to the following formula:

[0097]

[0098] in, Indicates The arrival time of the other transducers, represents the sampling period, Indicates the order of sampling times corresponding to the maximum power rise ratio.

[0099] Figure 2 Two sets of signal sampling data are provided for the embodiments of this specification, wherein the left figure is the sampling data of the ultrasonic signal received by the normal other transducer, and the right figure is the sampling data of the ultrasonic signal received by the damaged other transducer. It can be seen from the right figure that the signal fluctuates continuously and has noise. The signal value concentration time periods of the left figure and the right figure are basically the same. If the position calibration method provided in this specification is applied, the noise signal will not affect the accuracy of the calculation of the wave arrival time, and the position calibration method provided in this specification has good robustness to the noise signal.

[0100] S112: Calibrate the actual position of the transducer to be calibrated according to the estimated position of the transducer to be calibrated, the actual positions of the other transducers, the speed of sound, and the arrival time of the other transducers.

[0101] After determining the arrival time of each other transducer, the server constructs the target equation set required for iteration to solve the actual position of the transducer to be calibrated by iterative weighted least squares method.

[0102] For each other transducer, the server determines the distance between the other transducer and the transducer to be calibrated according to the product of the wave arrival time and the sound speed of the other transducer, and determines the equation of a circle with the transducer to be calibrated as the center and the distance as the radius according to the actual position of the other transducer, the estimated position of the transducer to be calibrated and the distance, as the original equation corresponding to the other transducer.

[0103] Figure 3 A schematic diagram of a primitive equation construction provided in the embodiments of this specification is shown in FIG. Figure 3 As shown in the figure, the dark dots in the hemispherical area represent other transducers, and the light dots above represent the transducer to be calibrated. The equation of a circle with the transducer to be calibrated as the center and the distance d between the other transducer and the transducer to be calibrated as the radius is used as the original equation corresponding to the other transducer. The distance d is determined according to the product of the wave arrival time of the other transducer and the initial sound velocity.

[0104] Secondly, the server determines the target set of equations based on the original equations corresponding to the other transducers.

[0105] Specifically, the server determines each pair of equations consisting of two different primitive equations in the primitive equations corresponding to each other transducer, and for each pair of equations, subtracts the two primitive equations included in the pair of equations to obtain the target equation of the pair of equations.

[0106] Among them, the objective equation can be determined according to the following process:

[0107] ①

[0108] ②

[0109] ③

[0110] Among them, the number of other transducers is hour, Desirable , Not equal to .

[0111] In the above formula, equation ① and equation ② respectively represent the original formulas of other transducers corresponding to the two equations in an equation pair, and equation ③ represents the target equation, which is derived from equation ②-equation ①. and They respectively represent the coordinates of the other transducers corresponding to the two equations in an equation pair, which are fixed values. Represents the coordinates of the transducer to be calibrated, which is iteratively updated in each round of iteration. represents the speed of sound, The coordinates are The corresponding arrival time of other transducers, The coordinates are The corresponding wave arrival time of other transducers.

[0112] The specific number of target equations is not limited in this specification, and the number of target equations is the number of equation pairs. The more target equations a target equation group contains, the more accurate the calibration result is. The specific number of transducer groups can be set according to the actual calibration accuracy.

[0113] In addition, in order to enable the estimated position of the transducer to be calibrated iteratively determined by the iterative weighted least squares method to converge, the number of transducers included in the transducer array may be set to at least 4, that is, at least 3 other transducers receiving ultrasonic signals.

[0114] After determining the target equations of each equation pair, the server combines the target equations of each equation pair to obtain the target equation group.

[0115] Finally, the server solves the target equations by weighted iterative least squares method to obtain the actual position of the transducer to be calibrated.

[0116] Equation ① and Equation ② are about , and The nonlinear equation of , obtained by subtracting equation ② from equation ①, is equation ③. , and The target equation group consisting of the equations in the form of equation ③ can be solved by iterative weighted least squares method.

[0117] Specifically, the server determines the target equation group in each round of iteration of the weighted iterative least squares method.

[0118] For each target equation in the target equation group during this round of iteration, the position of the transducer to be calibrated in the target equation is taken as an unknown term, and the coefficient terms of the three coordinate dimensions in the unknown terms and the constant term in the target equation are determined.

[0119] Taking the above equation ③ as the target equation, the unknown term is , among the unknown items The coefficient term is , among the unknown items The coefficient term is , among the unknown items The coefficient term is , the constant term in the objective equation is .

[0120] Then, the server substitutes the estimated position of the transducer to be calibrated updated in the previous iteration process and the actual position of each other transducer into the left side of equation ③ to obtain the intermediate value of this iteration process.

[0121] When the iterative process is the first iterative process, the server uses the intermediate value as the weighted value;

[0122] When the iteration process is not the first iteration process, the server determines the weighted value according to the product of the iteration weight of the target equation determined in the previous iteration process and the intermediate value. The difference between the constant term and the weighted value is used as the iteration weight of the target equation determined in the iteration process, and the next iteration process is continued until the first iteration stop condition is reached, the iteration is stopped, and the estimated position of the transducer to be calibrated updated when the iteration is stopped is used as the actual position of the transducer to be calibrated.

[0123] Because in the position calibration method of this specification, the wave arrival time is determined according to the power jump ratio, and the power jump ratio is robust to the wave arrival time calculation of the ultrasonic signal with noise, the server can accurately determine the wave arrival time of each other transducer. Based on the accuracy of the wave arrival time determination, the actual position of the transducer to be calibrated determined by the iterative weighted least squares method is also more accurate.

[0124] In this method, when the ultrasonic signal reaches other transducers, the signal values ​​of other transducers will change significantly, and the energy of the received ultrasonic signal is concentrated in M ​​sampling moments. The power jump ratio represents the average power difference of the signal value in two consecutive time periods. At the sampling moment when the ultrasonic signal is received, the average power of the subsequent M sampling moments will increase significantly compared with the average power of the previous sampling moments. Therefore, by calculating the power jump ratio at each sampling moment, the wave arrival time of other transducers can be accurately determined, thereby achieving accurate position calibration of the transducer to be calibrated.

[0125] Currently, when calibrating the position of a transducer, it is necessary to make the transducer to be calibrated emit an ultrasonic signal, calculate the arrival time of the ultrasonic signal emitted by the transducer to be calibrated and received by other transducers in the transducer array, and then determine the distance between the transducer to be calibrated and the transducer receiving the ultrasonic signal by multiplying the arrival time by the speed of sound of the ultrasonic signal, so as to calibrate the position of the transducer to be calibrated.

[0126] When determining the arrival time, the threshold method is usually used. The general practice of the threshold method is to set a threshold. The ultrasonic signal received by the transducer receiving the ultrasonic signal is sampled in advance to obtain the signal value at each sampling time, and the peak signal value is determined in each signal value. The sampling time when the first sampled signal value exceeds the threshold ratio of the peak signal value is taken as the arrival time.

[0127] When the threshold method is used to determine the arrival time, only the peak signal value is taken into account. When a noise signal is present, the arrival time determination may be disturbed, resulting in inaccurate arrival time determination and errors in transducer position calibration.

[0128] The iterative solution process of the target equation group in the above step S112 can be expressed in matrix form.

[0129] The specific steps are as follows:

[0130] The target equations can be expressed in the form of matrix equations: , represents the number of target equations contained in the target equation group, represents the unknown matrix, is the coordinate of the transducer to be calibrated. represents the coefficient matrix of the target system of equations, Represents the constant term matrix of the objective system of equations.

[0131] according to , we can get the equivalent equation , then it can be deduced that .in, is the weight matrix used for iteration.

[0132] Initialize the weight matrix by the identity matrix , express Middle The element value of the row, after initialization .

[0133] For each round of iteration, the server , determine the coordinates of the transducer to be calibrated in this round of iteration process, and at the same time, according to , determine the weight matrix of the next iteration process, continue the next iteration process until the first iteration stop condition is reached, and the coordinates of the transducer to be calibrated no longer change significantly in the continuous preset number of iterations, and the iteration stops. The server uses the actual position of the transducer to be calibrated iteratively updated in the last iteration process as the actual position of the transducer to be calibrated.

[0134] In one or more embodiments of the present specification, when the sound velocity is an estimated value, the position and sound velocity of the transducer to be calibrated can be calibrated simultaneously by an alternating calibration method.

[0135] In the above step S112, the position calibration process can be divided into multiple alternating iteration cycles. An alternating iteration cycle consists of a transducer iteration cycle and a sound velocity calibration process. A transducer iteration cycle is an iterative process of solving the target equation group by iterative weighted least squares method until the first iteration stop condition is reached. The iterative process described in the above step S112 is a transducer iteration cycle.

[0136] Specifically, for each iteration cycle, the server determines the target equation group of the alternating iteration cycle based on the estimated position of the transducer to be calibrated updated in the previous iteration cycle, the actual position of each other transducer, the estimated sound speed updated in the previous iteration cycle, and the wave arrival time of each other transducer.

[0137] In particular, the estimated sound speed of the first alternating iteration cycle is the sound speed determined by the server in step S102.

[0138] Then, the target equation group of the alternating iteration period is iteratively solved by the iterative weighted least squares method, and the estimated position of the transducer to be calibrated iteratively updated when the first iteration stop condition is reached is used as the actual position of the transducer to be calibrated iteratively updated in the alternating iteration period.

[0139] Specifically, for each iteration process of the transducer iteration cycle in the alternating iteration cycle, the solution is performed according to the iterative solution process in the above step S112 until the first iteration stop condition of the transducer iteration cycle is reached, and the estimated position of the transducer to be calibrated determined in the last iteration process of the transducer iteration cycle is used as the actual position of the transducer to be calibrated for iterative update of the alternating iteration cycle.

[0140] Next, the server determines whether the alternating iteration cycle reaches the second iteration stop condition, which is an iteration stop condition at the alternating iteration cycle level. When the second iteration stop condition is reached, the server no longer performs the iteration process of the next alternating iteration cycle. The second iteration stop condition is used to indicate that the iterative solution process converges at the alternating iteration cycle level, that is, in a continuous preset number of alternating iteration cycles, the actual position of the updated transducer to be calibrated no longer changes significantly, and the second iteration stop condition is reached.

[0141] When the alternating iteration cycle does not reach the second iteration stop condition, the server determines the estimated position of the transducer to be calibrated in the alternating iteration cycle, performs sound speed calibration, and updates the estimated sound speed to use the updated estimated sound speed for the position calibration iteration process of the next alternating iteration cycle.

[0142] The specific steps of the sound velocity calibration process are as follows:

[0143] First, the server determines, for each other transducer, the distance between the other transducer and the transducer to be calibrated in the alternating iteration cycle according to the actual position of the other transducer and the estimated position of the transducer to be calibrated iteratively updated in the alternating iteration cycle.

[0144] The server uses the ratio of the distance between the other transducer and the transducer to be calibrated in the alternating iteration period to the wave arrival time of the other transducer as the estimated sound speed corresponding to the other transducer in the alternating iteration period. According to the estimated sound speed corresponding to each other transducer in the alternating iteration period, the estimated sound speed updated in the alternating iteration period is determined.

[0145] Specifically, the server selects an estimated sound speed from the estimated sound speeds corresponding to the other transducers as the estimated sound speed updated in the alternating iteration period. This specification does not limit the specific method of selecting the estimated sound speed. For example, the server can select the estimated sound speed corresponding to the median, mean, mode, etc. of the estimated sound speeds as the initial sound speed updated in the alternating iteration period.

[0146] When the alternating iteration cycle reaches the second iteration stop condition, the estimated position of the transducer to be calibrated updated in the alternating iteration cycle is used as the actual position of the transducer to be calibrated. At the same time, the initial sound velocity updated in the previous alternating iteration cycle is used as the actual sound velocity of the ultrasonic signal.

[0147] In the position calibration process of this embodiment, an alternating calibration method is adopted. The position calibration is divided into multiple alternating iteration cycles. One alternating iteration cycle includes a complete iteration process of the least squares method and a calibration process of estimating the sound speed based on the coordinates of the transducer to be calibrated updated according to the alternating iteration cycle.

[0148] Because the speed of sound of ultrasonic signals cannot usually be accurately measured, during the position calibration process, the server needs to determine the distance between the other transducer and the transducer to be calibrated for each other transducer based on the speed of sound of the ultrasonic signal and the wave arrival time of the other transducer, and construct an initial equation with the distance as the radius. Therefore, the accuracy of the speed of sound of the ultrasonic signal will affect the accuracy of the position calibration. By calibrating the position and speed of sound of the transducer to be calibrated at the same time in this embodiment, the accuracy of the calibration result can be further improved.

[0149] In one or more embodiments of the present specification, because the ultrasonic signal is stronger in an underwater environment, when the position calibration method provided in the present specification is used, the ultrasonic array can be immersed in water, and the position calibration method described in the above steps S100 to S112 can be implemented in the underwater environment.

[0150] In the above process, the number of transducers to be calibrated is one. When the number of transducers to be calibrated in the transducer array is multiple, the estimated position of each transducer in the ultrasonic array is determined. The position calibration process of each transducer to be calibrated is divided into multiple array iteration cycles, and one array iteration cycle consists of the transducer iteration cycle of each transducer to be calibrated.

[0151] For each array iteration period, the server determines each to-be-calibrated transducer that needs to be calibrated in the array iteration period.

[0152] Then, for each transducer to be calibrated, assuming that the estimated positions of the other transducers in the transducer array other than the transducer to be calibrated are accurate positions, the estimated positions of the other transducers other than the transducer to be calibrated are taken as the actual positions of the other transducers. The actual position of the transducer to be calibrated is determined according to the method described in steps S100 to S112.

[0153] Next, after the server determines the updated estimated position of each transducer to be calibrated in the array iteration cycle, it determines whether the array iteration cycle reaches the third iteration stop condition. The third iteration stop condition is an iteration stop condition at the array iteration cycle level. When the third iteration stop condition is reached, the server no longer performs the iteration process of the next array iteration cycle. The third iteration stop condition is used to indicate that the iterative solution process converges at the array iteration cycle level, that is, in a continuous preset number of array iteration cycles, the updated estimated position of each transducer to be calibrated no longer changes significantly, and the third iteration stop condition is reached.

[0154] When the array iteration cycle reaches the third iteration stop condition, the estimated position of each to-be-calibrated transducer updated in the array iteration cycle is used as the actual position of each to-be-calibrated transducer. When the array iteration cycle does not reach the third iteration stop condition, the next array iteration cycle is continued.

[0155] In one or more embodiments of the present specification, when the sound speed is an estimated value of the sound speed of the ultrasonic signal, there are multiple transducers to be calibrated. Then the position calibration process of the multiple transducers to be calibrated in the transducer array can be composed of a triple iteration process, namely, an array iteration cycle, an alternating iteration cycle, and a transducer iteration cycle.

[0156] Figure 4 This is an iterative hierarchical diagram provided in the embodiments of this specification. Figure 4 The position calibration process of multiple transducers to be calibrated in the transducer array in this embodiment is described. Figure 4 As shown, the outermost iteration is an iteration at the array iteration cycle level. One array iteration cycle includes alternating iteration cycles of multiple different transducers to be calibrated. One alternating iteration cycle includes a transducer iteration cycle of a transducer to be calibrated and a sound velocity calibration process based on the estimated position updated at the end of the transducer iteration cycle.

[0157] The above is the ultrasonic transducer position calibration method provided in this specification. Based on the same idea, this specification also provides a corresponding ultrasonic transducer position calibration device, such as Figure 5 shown.

[0158] Figure 5 A schematic diagram of a position calibration device for an ultrasonic transducer provided in this specification specifically includes:

[0159] A calibration target determination module 200, used to determine the transducer to be calibrated and other transducers in the transducer array;

[0160] An ultrasonic transmitting module 202, used for controlling the transducer to be calibrated to transmit an ultrasonic signal, and each of the other transducers to receive the ultrasonic signal;

[0161] The sampling module 204 is used to sample the ultrasonic signal received by each other transducer and determine the signal value of the other transducer at each sampling time;

[0162] A sampling moment number determination module 206, used to determine the number M of sampling moments at which the ultrasonic signal is sampled according to the signal value of the other transducer at each sampling moment;

[0163] The power ramp ratio determination module 208 is used to determine the power ramp ratio at the sampling time ti according to the ratio of the average power of the signal value between the sampling time ti+1 and the sampling time ti+M to the average power of the signal value between the first sampling time t1 and the sampling time ti for the i-th sampling time ti;

[0164] The wave arrival time determination module 210 is used to determine the wave arrival time of the other transducer according to the power jump ratio at each sampling moment;

[0165] The calibration module 212 is used to calibrate the actual position of the transducer to be calibrated according to the estimated position of the transducer to be calibrated, the actual positions of the other transducers, the speed of sound and the arrival time of the other transducers.

[0166] The sampling moment quantity determination module 206 is specifically used to determine the time length that the other transducer receives the ultrasonic signal and the sampling period according to the signal value of the other transducer at each sampling moment, and determine the number M of sampling moments of sampling the ultrasonic signal according to the ratio of the time length that the other transducer receives the ultrasonic signal to the sampling period.

[0167] The arrival time determination module 210 is specifically used to determine the maximum power jump ratio among the power jump ratios at the sampling moments, determine the sampling moment corresponding to the maximum power jump ratio, determine the order among the sampling moments, determine the sampling period, and use the product of the order and the sampling period as the arrival time of the other transducer.

[0168] The calibration module 212 is specifically used to determine, for each other transducer, the distance between the other transducer and the transducer to be calibrated according to the product of the wave arrival time of the other transducer and the sound speed, and determine, according to the actual position of the other transducer, the estimated position of the transducer to be calibrated and the distance, the equation of a circle with the transducer to be calibrated as the center and the distance as the radius as the original equation corresponding to the other transducer, determine a target equation group according to the original equations corresponding to each other transducer, and solve the target equation group by weighted iterative least squares method to obtain the actual position of the transducer to be calibrated.

[0169] The calibration module 212 is specifically used to determine each equation pair consisting of two different original equations in the original equations corresponding to each other transducer, and for each equation pair, subtract the two original equations included in the equation pair to obtain the target equation of the equation pair, and combine the target equations of each equation pair to obtain a target equation group.

[0170] The calibration module 212, wherein the sound speed is an estimated value, divides the solution of the target equation group into multiple alternating iteration cycles, and is specifically used for determining the target equation group of the alternating iteration cycle according to the estimated position of the transducer to be calibrated iteratively updated in the previous alternating iteration cycle, the actual position of each other transducer, the estimated sound speed updated in the previous alternating iteration cycle, and the wave arrival time of each other transducer for each alternating iteration cycle, and solving the target equation group of the alternating iteration cycle by weighted iterative least squares method to obtain the estimated position of the transducer to be calibrated iteratively updated in the alternating iteration cycle, and judging whether the alternating iteration cycle reaches the second iteration stop condition, and if so, the estimated position of the transducer to be calibrated updated in the alternating iteration cycle is stopped. The estimated position is taken as the actual position of the transducer to be calibrated. If not, then for each other transducer, according to the actual position of the other transducer and the estimated position of the transducer to be calibrated iteratively updated in the alternating iteration period, the distance between the other transducer and the transducer to be calibrated in the alternating iteration period is determined, and the ratio of the distance between the other transducer and the transducer to be calibrated in the alternating iteration period to the wave arrival time of the other transducer is used as the estimated sound speed corresponding to the other transducer in the alternating iteration period, according to the estimated sound speed corresponding to each other transducer in the alternating iteration period, the estimated sound speed updated in the alternating iteration period is determined, and the iteration process of the next alternating iteration period is continued until the second iteration stop condition is reached.

[0171] The calibration module 212 is specifically used to determine the median of the estimated sound speeds corresponding to the other transducers in the alternating iteration period, and use the median as the estimated sound speed updated in the alternating iteration period.

[0172] This specification also provides a computer-readable storage medium, which stores a computer program, which can be used to execute the above Figure 1 A position calibration method for an ultrasonic transducer is provided.

[0173] This manual also provides Figure 6 The schematic structure diagram of the electronic device shown in FIG. Figure 6 As mentioned above, at the hardware level, the electronic device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory, and may also include other hardware required for the business. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it to achieve the above Figure 1 The ultrasonic transducer position calibration method. Of course, in addition to the software implementation, this specification does not exclude other implementation methods, such as logic devices or a combination of software and hardware, etc., that is, the execution subject of the following processing flow is not limited to each logic unit, but can also be hardware or logic devices.

[0174] For the improvement of a technology, it can be clearly distinguished whether it is a hardware improvement (for example, improvement of the circuit structure of diodes, transistors, switches, etc.) or a software improvement (improvement of the method flow). However, with the development of technology, many improvements of the method flow today can be regarded as direct improvements of the hardware circuit structure. Designers almost always obtain the corresponding hardware circuit structure by programming the improved method flow into the hardware circuit. Therefore, it cannot be said that the improvement of a method flow cannot be implemented with a hardware entity module. For example, a programmable logic device (PLD) (such as a field programmable gate array (FPGA)) is such an integrated circuit whose logical function is determined by the user's programming of the device. Designers can "integrate" a digital system on a PLD by programming themselves, without having to ask chip manufacturers to design and make dedicated integrated circuit chips. Moreover, nowadays, instead of manually making integrated circuit chips, this kind of programming is mostly implemented by "logic compiler" software, which is similar to the software compiler used when developing and writing programs, and the original code before compilation must also be written in a specific programming language, which is called hardware description language (HDL). There is not only one kind of HDL, but many kinds, such as ABEL (Advanced Boolean Expression Language), AHDL (Altera Hardware Description Language), Confluence, CUPL (Cornell University Programming Language), HDCal, JHDL (Java Hardware Description Language), Lava, Lola, MyHDL, PALASM, RHDL (Ruby Hardware Description Language), etc. The most commonly used ones are VHDL (Very-High-Speed ​​Integrated Circuit Hardware Description Language) and Verilog. Those skilled in the art should also know that it is only necessary to program the method flow slightly in the above-mentioned hardware description languages ​​and program it into the integrated circuit, and then it is easy to obtain the hardware circuit that implements the logic method flow.

[0175] The controller may be implemented in any suitable manner, for example, the controller may take the form of a microprocessor or processor and a computer-readable medium storing a computer-readable program code (e.g., software or firmware) executable by the (micro)processor, a logic gate, a switch, an application-specific integrated circuit (ASIC), a programmable logic controller, and an embedded microcontroller, examples of which include but are not limited to the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20, and Silicone Labs C8051F320, and the memory controller may also be implemented as part of the control logic of the memory. It is also known to those skilled in the art that, in addition to implementing the controller in a purely computer-readable program code manner, the controller may be implemented in the form of a logic gate, a switch, an application-specific integrated circuit, a programmable logic controller, and an embedded microcontroller by logically programming the method steps. Therefore, such a controller may be considered as a hardware component, and the devices for implementing various functions included therein may also be considered as structures within the hardware component. Or even, the devices for implementing various functions may be considered as both software modules for implementing the method and structures within the hardware component.

[0176] The systems, devices, modules or units described in the above embodiments may be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer. Specifically, the computer may be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

[0177] For the convenience of description, the above device is described in various units according to their functions. Of course, when implementing this specification, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0178] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0179] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0180] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0181] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0182] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0183] The memory may include non-permanent storage in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0184] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0185] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0186] It should be understood by those skilled in the art that the embodiments of this specification may be provided as methods, systems or computer program products. Therefore, this specification may take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware. Moreover, this specification may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0187] This specification may be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. This specification may also be practiced in distributed computing environments where tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules may be located in local and remote computer storage media, including storage devices.

[0188] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0189] The above description is only an embodiment of this specification and is not intended to limit this specification. For those skilled in the art, this specification may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this specification should be included in the scope of the claims of this application.

Claims

1. A method for calibrating the position of an ultrasonic transducer, characterized in that: include: Determining a transducer to be calibrated and other transducers in the transducer array; Controlling the transducer to be calibrated to transmit an ultrasonic signal, and each of the other transducers to receive the ultrasonic signal; For each other transducer, sampling the ultrasonic signal received by the other transducer, and determining the signal value of the other transducer at each sampling time; Determine the number M of sampling moments at which the ultrasonic signal is sampled according to the signal value of the other transducer at each sampling moment; For the kth sampling time t k , according to the sampling time t k+1 To sampling time t k+M The average power of the signal value between the first sampling time t1 and the sampling time t k The ratio of the average power of the signal values ​​between the two determines the sampling time t k The power transition ratio is determined by the following formula: in, Indicates The other transducers are in The power jump ratio at the sampling moment is Indicates The other transducers are sampled from the first sampling moment to the The energy at each sampling moment, Indicates the first sampling time to the Between sampling times The average power at the sampling time, Indicates The other transducers are from Sampling time to The energy at each sampling moment, Indicates Sampling time to Between sampling times The average power at each sampling moment; Determining the arrival time of the other transducer according to the power jump ratio at each sampling moment; The actual position of the transducer to be calibrated is calibrated according to the estimated position of the transducer to be calibrated, the actual positions of the other transducers, the speed of sound and the arrival time of the other transducers.

2. The method according to claim 1, characterized in that Determining the number M of sampling moments at which the ultrasonic signal is sampled according to the signal value of the other transducer at each sampling moment specifically includes: Determining the length of time that the other transducer receives the ultrasonic signal according to the signal value of the other transducer at each sampling moment; A sampling period is determined, and the number M of sampling moments at which the ultrasonic signal is sampled is determined according to a ratio of a time length during which the other transducer receives the ultrasonic signal to the sampling period.

3. The method according to claim 1, characterized in that Determining the arrival time of the other transducer according to the power jump ratio at each sampling moment specifically includes: Among the power ramp ratios at the sampling moments, determining the maximum power ramp ratio; Determine the order of the sampling moments corresponding to the maximum power ramp ratio among the sampling moments; A sampling period is determined, and the product of the order and the sampling period is taken as the arrival time of the other transducer.

4. The method according to claim 1, characterized in that Calibrate the actual position of the transducer to be calibrated according to the estimated position of the transducer to be calibrated, the actual position of each of the other transducers, the speed of sound, and the wave arrival time of each of the other transducers, specifically including: For each other transducer, determining the distance between the other transducer and the transducer to be calibrated according to the product of the wave arrival time of the other transducer and the sound velocity; According to the actual position of the other transducer, the estimated position of the transducer to be calibrated and the distance, determine the equation of a circle with the transducer to be calibrated as the center and the distance as the radius, as the original equation corresponding to the other transducer; Determine the target equation group according to the original equations corresponding to each other transducer; The target equation group is solved by weighted iterative least square method to obtain the actual position of the transducer to be calibrated.

5. The method according to claim 1, characterized in that According to the original equations corresponding to the other transducers, the target equation group is determined, which specifically includes: In the primitive equations corresponding to the other transducers, each pair of equations consisting of two different primitive equations is determined; For each equation pair, subtract the two original equations contained in the equation pair to obtain the target equation of the equation pair; The target equations of each pair of equations are combined to obtain the target equation group.

6. The method according to claim 1, characterized in that The sound speed is an estimated value, and the solution of the target equation group is divided into multiple alternating iteration cycles; Calibrate the actual position of the transducer to be calibrated according to the estimated position of the transducer to be calibrated, the actual position of each of the other transducers, the speed of sound, and the wave arrival time of each of the other transducers, specifically including: For each alternating iteration cycle, determine the target equation group of the alternating iteration cycle according to the estimated position of the transducer to be calibrated iteratively updated in the previous alternating iteration cycle, the actual position of each of the other transducers, the estimated sound velocity updated in the previous alternating iteration cycle, and the wave arrival time of each of the other transducers; Solving the target equation group of the alternating iteration period by weighted iterative least square method to obtain the estimated position of the transducer to be calibrated which is iteratively updated in the alternating iteration period; Determine whether the alternating iteration cycle reaches the second iteration stop condition; If yes, the estimated position of the transducer to be calibrated updated in the alternating iteration period is used as the actual position of the transducer to be calibrated; If not, then for each other transducer, according to the actual position of the other transducer and the estimated position of the transducer to be calibrated iteratively updated in the alternating iteration period, determine the distance between the other transducer and the transducer to be calibrated in the alternating iteration period; use the ratio of the distance between the other transducer and the transducer to be calibrated in the alternating iteration period to the wave arrival time of the other transducer as the estimated sound speed corresponding to the other transducer in the alternating iteration period; according to the estimated sound speed corresponding to each other transducer in the alternating iteration period, determine the estimated sound speed updated in the alternating iteration period, and continue the iteration process of the next alternating iteration period until the second iteration stop condition is reached.

7. The method according to claim 6, characterized in that Determining the estimated sound speed updated in the alternating iterative cycle according to the estimated sound speed corresponding to each other transducer in the alternating iterative cycle specifically includes: Determine the median of the estimated sound speeds corresponding to each of the other transducers in the alternating iteration cycle; The median is used as the estimated sound speed updated in the alternating iteration cycle.

8. A position calibration device for an ultrasonic transducer, characterized in that: include: A calibration target determination module determines the transducer to be calibrated and other transducers in the transducer array; An ultrasonic transmitting module controls the transducer to be calibrated to transmit an ultrasonic signal, and each of the other transducers receives the ultrasonic signal; A sampling module, for each other transducer, samples the ultrasonic signal received by the other transducer, and determines the signal value of the other transducer at each sampling time; A sampling moment number determination module, which determines the number M of sampling moments at which the ultrasonic signal is sampled according to the signal value of the other transducer at each sampling moment; The power ramp ratio determination module is used for the kth sampling time t k , according to the sampling time t k+1 To sampling time t k+M The average power of the signal value between the first sampling time t1 and the sampling time t k The ratio of the average power of the signal values ​​between the two determines the sampling time t k The power transition ratio is determined by the following formula: in, Indicates The other transducers are in The power jump ratio at the sampling moment is Indicates The other transducers are sampled from the first sampling moment to the The energy at each sampling moment, Indicates the first sampling time to the Between sampling times The average power at the sampling time, Indicates The other transducers are from Sampling time to The energy at each sampling moment, Indicates Sampling time to Between sampling times The average power at each sampling moment; A wave arrival time determination module, which determines the wave arrival time of the other transducer according to the power jump ratio at each sampling moment; The calibration module calibrates the actual position of the transducer to be calibrated according to the estimated position of the transducer to be calibrated, the actual positions of the other transducers, the speed of sound and the arrival time of the other transducers.

9. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by a processor, the method described in any one of claims 1 to 7 is implemented.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the method described in any one of claims 1 to 7 is implemented.

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