Picosecond-level delay precision control device and method for electromagnetic ultrasonic phased array

Abstract

The invention discloses a picosecond-level delay precision control device and method for an electromagnetic ultrasonic phased array, and relates to the technical field of ultrasonic nondestructive testing, and the device comprises an upper computer, a multi-channel transmitting system, an electromagnetic ultrasonic transducer and a multi-channel receiving system; the upper computer is used for setting parameters and sending the parameters to the multi-channel transmitting system; the multi-channel transmitting system comprises a picosecond-level channel delay excitation module, the multi-channel receiving system comprises a picosecond-level channel delay receiving module, and compared with a traditional phased array device, the picosecond-level channel delay excitation module and the picosecond-level channel delay receiving module are higher in delay control precision. On the basis of a traditional electromagnetic ultrasonic phased array, the detection precision is greatly improved.

Description

Technical Field

[0001] The present application relates to the technical field of ultrasonic nondestructive testing, and in particular to a device and method for controlling picosecond delay accuracy of an electromagnetic ultrasonic phased array. Background Art

[0002] Electromagnetic ultrasonic testing technology has the advantages of intuitive test results, high detection accuracy, no need for coupling agents, non-contact, and non-destructiveness. It has been widely used in industrial non-destructive testing.

[0003] The electromagnetic ultrasonic phased array device detects defect locations by utilizing the principle that ultrasonic waves will be reflected when they encounter defects during propagation in the test piece. The generation of ultrasonic waves requires the cooperation of the host computer and the transmitting circuit, and accurate scanning is achieved through the programmable delay of each channel. The host computer transmits the waveform value and channel delay parameters required for the excitation waveform to the transmitting circuit. The transmitting circuit controls the DAC of the FPGA to convert the digital waveform into an electrical signal, and then excites the coil of the transducer through the high-voltage amplifier circuit. Phased array equipment using this method will inevitably introduce hardware delays during the DAC conversion and high-voltage conversion process. The delay accuracy of the transmitter will affect the accuracy of the sound beam scanning angle and the resolution of the system.

[0004] The delay time between channels of traditional electromagnetic ultrasonic phased array devices is controlled by FPGA, and the delay is in nanoseconds. FPGA generates counters according to internal clocks. When the counters count to the specified value, the corresponding channels are excited. In this case, the performance of FPGA chips has a great influence on the delay accuracy. For example, the stable working clock of Xilinx's Spartan series chips is below 200MHz. Using this chip to directly generate a 400MHz clock to drive the counter to form a 2.5ns delay, its accuracy cannot be guaranteed. Through the PLL IP core, the delay is realized by phase shifting, which will introduce phase errors. The time when traditional electromagnetic ultrasonic phased array devices receive echo signals is controlled by FPGA. When the transmitting module starts to excite, the module will synchronize the excitation signal to the receiving module. The receiving module starts timing. When the timing reaches a certain time, it starts to receive echo data. There is the same problem as the traditional phased array excitation. The receiving signal depends on the timing function of FPGA. As the number of channels of phased array devices increases, the delay accuracy will have a greater impact on the final detection imaging results.

[0005] In summary, multiple hardware delays will be introduced between the FPGA digital signal and the high-voltage excitation ultrasonic transducer, and each channel cannot be excited strictly according to the channel delay set by the program. The receiving module is also subject to the conversion of electrical signals and digital signals and the FPGA counter. Summary of the invention

[0006] The purpose of this application is to provide a picosecond delay accuracy control device and method for an electromagnetic ultrasonic phased array, which can achieve picosecond delay accuracy. The improvement of the excitation delay and receiving delay accuracy makes the measurement results more accurate.

[0007] To achieve the above objectives, this application provides the following solutions.

[0008] In a first aspect, the present application provides a picosecond delay precision control device for an electromagnetic ultrasonic phased array, wherein the picosecond delay precision control device for an electromagnetic ultrasonic phased array comprises: a host computer, a multi-channel transmitting system, an electromagnetic ultrasonic transducer and a multi-channel receiving system.

[0009] The host computer is used to set parameters and send the parameters to the multi-channel transmission system; the parameters include: transmission timing, amplitude of the excitation waveform voltage and excitation frequency.

[0010] The multi-channel transmitting system comprises: a first FPGA module, a first DDR buffer module, a DAC module, a high-voltage amplification module and a picosecond channel delay excitation module.

[0011] The first FPGA module is used to control the parameters to be sent to the first DDR cache module for caching, and is also used to control the DAC module to convert the parameters into electrical signals and transmit them to the high-voltage amplifier module.

[0012] The high-voltage amplification module is used to convert the electrical signal into a high-voltage pulse signal.

[0013] The picosecond channel delay excitation module is used to trigger the high-voltage pulse signal of the corresponding channel in a time sequence based on a fixed delay time to form an ultrasonic wave of a corresponding time sequence.

[0014] The electromagnetic ultrasonic transducer is used to realize the conversion between electrical signals and ultrasonic signals; it is used to convert electrical signals into ultrasonic excitation in the transmitting stage, and is used to receive echo signals and convert them into electrical signals in the receiving stage; the echo signal is the signal generated when the ultrasonic wave contacts the test piece; the echo signal includes defect information.

[0015] The multi-channel receiving system comprises: a picosecond channel delay receiving module, a gain amplifying circuit, a filtering circuit, a second DDR buffer module, a second FPGA module and an ADC module.

[0016] The picosecond channel delay receiving module is used to receive the echo signals of each channel in time sequence based on another fixed delay time.

[0017] The gain amplifier circuit is used to amplify the echo signals of each channel to obtain amplified echo signals.

[0018] The filtering circuit is used to filter the amplified echo signal to obtain a filtered echo signal.

[0019] The second FPGA module is used to control the ADC module to perform ADC conversion on the filtered echo signal to obtain a converted echo signal; it is also used to control the second DDR cache module to cache the converted echo signal and send the converted echo signal to the host computer.

[0020] The host computer is also used to receive the converted echo signal, perform gradient matching on the echo amplitude according to the color, and generate a detection result image.

[0021] In the second aspect, the present application provides a picosecond delay accuracy control method for an electromagnetic ultrasonic phased array, which is applied to the picosecond delay accuracy control device for the electromagnetic ultrasonic phased array described above, and the picosecond delay accuracy control method for the electromagnetic ultrasonic phased array includes the following steps.

[0022] Obtain the parameters set by the host computer; the parameters include: emission timing, amplitude of the excitation waveform voltage and excitation frequency.

[0023] The parameters are converted into electrical signals.

[0024] Based on the fixed delay time and the electrical signal, an ultrasonic wave of corresponding timing is generated.

[0025] Based on another fixed delay time, the echo signals of each channel are received in sequence; the echo signals are signals generated when the ultrasonic wave contacts the object under test; the echo signals include defect information.

[0026] Based on the echo signals of each channel, a detection result image is obtained.

[0027] According to the specific embodiments provided in this application, this application discloses the following technical effects.

[0028] The present application provides a picosecond delay accuracy control device and method for an electromagnetic ultrasonic phased array, the device comprising: a host computer, a multi-channel transmitting system, an electromagnetic ultrasonic transducer and a multi-channel receiving system; wherein the multi-channel transmitting system comprises a picosecond channel delay excitation module, and the multi-channel receiving system comprises a picosecond channel delay receiving module. Compared with traditional phased array equipment, the picosecond channel delay excitation module and the picosecond channel delay receiving module used have higher control accuracy for delay, which greatly improves the detection accuracy on the basis of the traditional electromagnetic ultrasonic phased array. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 A schematic diagram of the structure of a picosecond delay accuracy control device for an electromagnetic ultrasonic phased array provided in one embodiment of the present application.

[0031] Figure 2 A schematic diagram of the structure of a picosecond channel delay excitation module provided in one embodiment of the present application.

[0032] Figure 3 A schematic diagram of the structure of a picosecond channel delay receiving module provided in one embodiment of the present application.

[0033] Figure 4 Schematic diagram of the detection results using traditional phased array equipment.

[0034] Figure 5 Schematic diagram of the detection results using the device of the present application.

[0035] Figure 6 A schematic diagram of the detection process of a phased array electromagnetic ultrasonic method provided in one embodiment of the present application.

[0036] Figure 7 A schematic flow chart of a method for controlling picosecond delay accuracy of an electromagnetic ultrasonic phased array provided in one embodiment of the present application. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0038] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0039] In an exemplary embodiment, Figure 1 As shown, a picosecond delay precision control device for an electromagnetic ultrasonic phased array is provided, and the picosecond delay precision control device for an electromagnetic ultrasonic phased array includes: a host computer, a multi-channel transmitting system, an electromagnetic ultrasonic transducer and a multi-channel receiving system.

[0040] The host computer is used to set parameters and send the parameters to the multi-channel transmission system; the parameters include: transmission timing, amplitude of the excitation waveform voltage and excitation frequency.

[0041] The multi-channel transmitting system comprises: a first FPGA module, a first DDR buffer module, a DAC module, a high-voltage amplification module and a picosecond channel delay excitation module.

[0042] The first FPGA module is used to control the parameters to be sent to the first DDR cache module for caching, and is also used to control the DAC module to convert the parameters into electrical signals and transmit them to the high-voltage amplifier module.

[0043] The high-voltage amplification module is used to convert the electrical signal into a high-voltage pulse signal.

[0044] The picosecond channel delay excitation module is used to trigger the high-voltage pulse signal of the corresponding channel in a time sequence based on a fixed delay time to form an ultrasonic wave of a corresponding time sequence.

[0045] The electromagnetic ultrasonic transducer includes a permanent magnet and a multi-channel coil, which is used to realize the conversion between electrical signals and ultrasonic signals; it is used to convert electrical signals into ultrasonic excitation in the transmitting stage, and is used to receive echo signals and convert them into electrical signals in the receiving stage; the echo signal is a signal generated when the ultrasonic wave contacts the test piece; the echo signal includes defect information.

[0046] The multi-channel receiving system comprises: a picosecond channel delay receiving module, a gain amplifying circuit, a filtering circuit, a second DDR buffer module, a second FPGA module and an ADC module.

[0047] The picosecond channel delay receiving module is used to receive the echo signals of each channel in time sequence based on another fixed delay time.

[0048] The gain amplifier circuit is used to amplify the echo signals of each channel to obtain amplified echo signals.

[0049] The filtering circuit is used to filter the amplified echo signal to obtain a filtered echo signal.

[0050] The second FPGA module is used to control the ADC module to perform ADC conversion on the filtered echo signal to obtain a converted echo signal; it is also used to control the second DDR cache module to cache the converted echo signal and send the converted echo signal to the host computer.

[0051] The host computer is also used to receive the converted echo signal, perform gradient matching on the echo amplitude according to the color, and generate a detection result image.

[0052] Among them, the host computer: sets the emission timing in the parameters, realizes the deflection of the ultrasonic angle in the tested object, sets the amplitude and excitation frequency of the excitation waveform voltage. Sends the parameters to each channel in the multi-channel emission system to realize the scanning of the defect area, and is equipped with a host computer program for waveform synthesis and an RGB imaging interface.

[0053] Multi-channel transmitting system: used to send multiple high-voltage pulse signals to the electromagnetic ultrasonic transducer to stimulate ultrasonic waves according to the transmitting timing of each channel in the set parameters.

[0054] Compared with the traditional electromagnetic ultrasonic phased array, the multi-channel transmission system adds a picosecond channel delay excitation module. The first FPGA module controls the parameters set by the host computer to be sent to the first DDR cache module. After a packet of transmission data is transmitted, the first FPGA module controls the DAC module to convert the digital signal into an electrical signal and transmit it to the high-voltage amplifier module. After high-voltage amplification, the low voltage is converted into a kilovolt high voltage, and then transmitted to the picosecond channel delay excitation module, which finally controls the excitation of the corresponding channel.

[0055] Electromagnetic ultrasonic transducer: It includes permanent magnets and multi-channel coils. Electromagnetic ultrasonic transducers can realize the conversion between electrical signals and ultrasonic signals. In the transmitting stage, it is used to convert electrical signals into ultrasonic excitation, and in the receiving stage, it is used to receive echo signals and convert them into electrical signals.

[0056] Multi-channel receiving system: Introduces picosecond channel delay receiving function instead of using FPGA timer.

[0057] The present application aims to solve the problems of low accuracy of excitation channel delay and received echo signal delay in existing electromagnetic ultrasonic detection systems. Traditional phased array channel delay is implemented by using FPGA to generate a counter. The present application adds a picosecond channel delay excitation module and a picosecond channel delay receiving module on the basis of the traditional phased array, thereby improving the detection accuracy of the electromagnetic ultrasonic phased array.

[0058] like Figure 2 As shown, the picosecond channel delay excitation module includes: a plurality of first voltage-controlled delay units, a plurality of first triggers and a first high-precision DAC; each of the first triggers corresponds to a first voltage-controlled delay unit.

[0059] The first FPGA module is also used to set the digital value of the first high-precision DAC voltage value.

[0060] The first high-precision DAC is used to set a first voltage value for each of the first voltage-controlled delay units.

[0061] The first voltage-controlled delay unit is used to set a first delay time according to the first voltage value.

[0062] The first trigger is used to trigger the corresponding channel to be excited when the delay of the first voltage-controlled delay unit ends, and simultaneously trigger the second delay unit to start working, thereby triggering the high-voltage pulse signal of the corresponding channel in sequence to form an ultrasonic wave of the corresponding sequence.

[0063] In the picosecond channel delay excitation module, the first FPGA module sets the digital value of the first high-precision DAC voltage value. The voltage value of the first high-precision DAC enables the voltage-controlled delay unit to form a fixed delay time, rather than using the FPGA counter to do the excitation delay. When the high-voltage pulse signal that starts the excitation is transmitted to the picosecond channel delay excitation module, the first voltage-controlled delay unit starts to work. Every time a first voltage-controlled delay unit is passed, the first trigger corresponding to the voltage-controlled delay unit is triggered for the set delay time. The first trigger will trigger the high-voltage pulse signal of the corresponding channel and trigger the second first voltage-controlled delay unit to start working. After passing through multiple first voltage-controlled delay units in sequence, multiple corresponding channels will be excited to form ultrasonic waves with corresponding timing.

[0064] When the ultrasonic wave encounters the defect position, it is reflected. The echo signal contains the defect information and is converted into an electrical signal again by the electromagnetic ultrasonic transducer and transmitted to the multi-channel receiving system.

[0065] like Figure 3 As shown, the picosecond channel delay receiving module includes: a second high-precision DAC, a third high-precision DAC, a voltage-controlled delay unit combination, a second trigger corresponding to the voltage-controlled delay unit combination, a plurality of second voltage-controlled delay units connected to the voltage-controlled delay unit combination, and a plurality of third triggers; each of the third triggers corresponds to a second voltage-controlled delay unit.

[0066] The second FPGA module is also used to set the digital value of the second high-precision DAC voltage value and the digital value of the third high-precision DAC voltage value.

[0067] The second high-precision DAC is used to set a second voltage value for the voltage-controlled delay unit combination.

[0068] The third high-precision DAC is used to set a third voltage value for each of the second voltage-controlled delay units.

[0069] The voltage-controlled delay unit combination is used to set the second delay time according to the second voltage value.

[0070] The second trigger is used to start receiving the echo signal when the combined delay of the voltage-controlled delay unit ends.

[0071] The second voltage-controlled delay unit is used to set a third delay time according to a third voltage value.

[0072] The third trigger is used to trigger the corresponding channel when the delay of the second voltage-controlled delay unit ends, and simultaneously trigger the next second voltage-controlled delay unit to start working.

[0073] When the multi-channel transmitting system starts to be excited, the signal is transmitted to the multi-channel receiving system, the picosecond channel delay receiving module starts timing, and the second voltage-controlled delay unit is used for timing. The second FPGA module of the multi-channel receiving system controls the second high-precision DAC, and sets the second voltage value for the voltage-controlled delay unit combination. The set second voltage value forms a fixed delay value, and the echo signal is received when the timing ends.

[0074] When the echo signal is transmitted to the multi-channel receiving system, the second FPGA module is used to control the third high-precision DAC to set the voltage value. During the receiving process, each time the electrical signal passes through a third voltage-controlled delay unit, an echo signal is formed, which gets rid of the clock error caused by the FPGA counter. The received data will pass through: the gain amplifier circuit amplifies the signal to the volt level to obtain the amplified echo signal, the filter circuit removes clutter to obtain the filtered echo signal, the ADC module performs ADC conversion on the filtered echo signal to obtain the converted echo signal, the second DDR cache module caches the converted echo signal, and the imaging data is cached and transmitted to the host computer via USB.

[0075] The host computer receives the converted echo signal and performs gradient matching on the echo amplitude according to the color, from red to blue from the smallest to the largest, and displays it on the screen in the form of RGB. Figure 4 and Figure 5 shown.

[0076] For example, testing and imaging of defective test blocks. Figure 4 As shown, the test results of this application are as follows Figure 5 As shown in the figure, the imaging defects of the conventional phased array equipment are deformed. However, the imaging of the detection result of the present application is clearer and more accurate.

[0077] In another exemplary embodiment of the present application, Figure 6 and Figure 7As shown, a picosecond delay accuracy control method for an electromagnetic ultrasonic phased array is provided. The picosecond delay accuracy control method for an electromagnetic ultrasonic phased array is applied to the picosecond delay accuracy control device for an electromagnetic ultrasonic phased array described above. The picosecond delay accuracy control method for an electromagnetic ultrasonic phased array includes the following steps.

[0078] S1: Obtain the parameters set by the host computer; the parameters include: emission timing, amplitude of the excitation waveform voltage and excitation frequency.

[0079] S2: Convert the parameters into electrical signals.

[0080] S3: Based on the fixed delay time and the electrical signal, an ultrasonic wave of corresponding timing is generated.

[0081] S4: Based on another fixed delay time, receiving the echo signal of each channel in time sequence; the echo signal is a signal generated when the ultrasonic wave contacts the test piece; the echo signal includes defect information.

[0082] S5: Obtain a detection result image based on the echo signals of each channel.

[0083] Compared with the FPGA counter delay method of the traditional electromagnetic ultrasonic phased array, the delay method of the present application can achieve picosecond delay accuracy. The improvement of the excitation delay and receiving delay accuracy makes the measurement results more accurate.

[0084] In an exemplary embodiment, step S3 specifically includes the following steps.

[0085] S31: performing high-voltage amplification processing on the electrical signal to obtain a high-voltage pulse signal.

[0086] S32: Setting the digital value of the first high-precision DAC voltage value.

[0087] S33: Setting a first voltage value for each first voltage-controlled delay unit based on the digital value of the first high-precision DAC voltage value.

[0088] S34: setting a first delay time according to the first voltage value.

[0089] S35: Based on the corresponding first delay time, trigger the high-voltage pulse signal of the corresponding channel in a time sequence to form an ultrasonic wave of a corresponding time sequence.

[0090] In an exemplary embodiment, step S4 specifically includes the following steps.

[0091] S41: respectively setting the digital value of the second high-precision DAC voltage value and the digital value of the third high-precision DAC voltage value.

[0092] S42: Based on the digital value of the second high-precision DAC voltage value, set a second voltage value for the voltage-controlled delay unit combination.

[0093] S43: Setting a second delay time according to the second voltage value.

[0094] S44: Setting a third voltage value for each second voltage-controlled delay unit based on the digital value of the third high-precision DAC voltage value.

[0095] S45: Setting a third delay time according to the third voltage value.

[0096] S46: When the second delay time ends, based on the corresponding third delay time, the echo signals of each channel are received in time sequence.

[0097] In an exemplary embodiment, step S5 specifically includes the following steps.

[0098] S51: Amplify the echo signals of the channels to obtain amplified echo signals.

[0099] S52: Filter the amplified echo signal to obtain a filtered echo signal.

[0100] S53: Perform ADC conversion on the filtered echo signal to obtain a converted echo signal.

[0101] S54: Based on the converted echo signal, gradient matching is performed on the echo amplitude according to the color to generate a detection result image.

[0102] In an exemplary embodiment, step S54 specifically includes the following contents.

[0103] Based on the converted echo signal, the echo amplitude is gradient matched according to the color, from the smallest to the largest, from red to blue, and displayed on the screen in the form of RGB to obtain a detection result image.

[0104] In addition, the method for controlling picosecond delay accuracy of the electromagnetic ultrasonic phased array further includes: caching the parameters.

[0105] In another exemplary embodiment of the present application, the method for controlling picosecond delay accuracy of the electromagnetic ultrasonic phased array further includes: caching the converted echo signal.

[0106] In response to the low delay accuracy of the electromagnetic ultrasonic phased array, the present application provides a picosecond delay accuracy control method for the electromagnetic ultrasonic phased array, which can achieve high-precision channel delay excitation and high-precision timing reception, thereby enhancing the detection effect of the equipment.

[0107] The present application also provides an application scenario, which applies the above-mentioned picosecond delay accuracy control method of the electromagnetic ultrasonic phased array. Specifically: The picosecond delay accuracy control method of the electromagnetic ultrasonic phased array provided in this embodiment can be applied in the ultrasonic non-destructive testing technology scenario. The ultrasonic non-destructive testing technology scenario includes: a parameter setting link, a corresponding timing ultrasonic wave formation link, an echo signal receiving link, and a detection result determination link. First, the parameters set by the host computer are obtained, and the parameters are converted into electrical signals; secondly, based on a fixed delay time and the electrical signal, an ultrasonic wave of the corresponding timing is formed; then, based on another fixed delay time, the echo signals of each channel are received in sequence; the echo signal is a signal generated when the ultrasonic wave contacts the test piece; the echo signal includes defect information; finally, based on the echo signals of each channel, the detection result image can be obtained.

[0108] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0109] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A picosecond delay accuracy control device for an electromagnetic ultrasonic phased array, characterized in that: The picosecond delay precision control device of the electromagnetic ultrasonic phased array comprises: a host computer, a multi-channel transmitting system, an electromagnetic ultrasonic transducer and a multi-channel receiving system; The host computer is used to set parameters and send the parameters to the multi-channel transmission system; the parameters include: transmission timing, amplitude of the excitation waveform voltage and excitation frequency; The multi-channel transmission system includes: a first FPGA module, a first DDR cache module, a DAC module, a high-voltage amplifier module and a picosecond channel delay excitation module; The first FPGA module is used to control the parameters to be sent to the first DDR cache module for caching, and is also used to control the DAC module to convert the parameters into electrical signals and transmit them to the high-voltage amplification module; The high-voltage amplification module is used to convert the electrical signal into a high-voltage pulse signal; The picosecond channel delay excitation module is used to trigger the high-voltage pulse signal of the corresponding channel in a time sequence based on a fixed delay time to form an ultrasonic wave of a corresponding time sequence; The electromagnetic ultrasonic transducer is used to realize the conversion between electrical signals and ultrasonic signals; it is used to convert electrical signals into ultrasonic excitation in the transmitting stage, and is used to receive echo signals and convert them into electrical signals in the receiving stage; the echo signal is a signal generated when the ultrasonic wave contacts the test piece; the echo signal includes defect information; The multi-channel receiving system comprises: a picosecond channel delay receiving module, a gain amplification circuit, a filtering circuit, a second DDR cache module, a second FPGA module and an ADC module; The picosecond channel delay receiving module is used to receive the echo signals of each channel in time sequence based on another fixed delay time; The gain amplifier circuit is used to amplify the echo signals of each channel to obtain amplified echo signals; The filtering circuit is used to filter the amplified echo signal to obtain a filtered echo signal; The second FPGA module is used to control the ADC module to perform ADC conversion on the filtered echo signal to obtain a converted echo signal; and is also used to control the second DDR cache module to cache the converted echo signal and send the converted echo signal to the host computer; The host computer is also used to receive the converted echo signal, perform gradient matching on the echo amplitude according to the color, and generate a detection result image.

2. The device for controlling picosecond delay accuracy of an electromagnetic ultrasonic phased array according to claim 1, characterized in that: The picosecond channel delay excitation module includes: a plurality of first voltage-controlled delay units, a plurality of first triggers and a first high-precision DAC; each of the first triggers corresponds to a first voltage-controlled delay unit; The first FPGA module is further used to set the digital value of the first high-precision DAC voltage value; The first high-precision DAC is used to set a first voltage value for each of the first voltage-controlled delay units; The first voltage-controlled delay unit is used to set a first delay time according to the first voltage value; The first trigger is used to trigger the corresponding channel to be excited when the delay of the first voltage-controlled delay unit ends, and simultaneously trigger the next first voltage-controlled delay unit to start working, thereby triggering the high-voltage pulse signal of the corresponding channel in sequence to form an ultrasonic wave of corresponding sequence.

3. The device for controlling picosecond delay accuracy of an electromagnetic ultrasonic phased array according to claim 1, characterized in that: The picosecond channel delay receiving module includes: a second high-precision DAC, a third high-precision DAC, a voltage-controlled delay unit combination, a second trigger, a plurality of second voltage-controlled delay units connected to the voltage-controlled delay unit combination, and a plurality of third triggers; each of the third triggers corresponds to a second voltage-controlled delay unit; The second FPGA module is further used to set the digital value of the second high-precision DAC voltage value and the digital value of the third high-precision DAC voltage value; The second high-precision DAC is used to set a second voltage value for the voltage-controlled delay unit combination; The third high-precision DAC is used to set a third voltage value for each of the second voltage-controlled delay units; The voltage-controlled delay unit combination is used to set a second delay time according to the second voltage value; The second trigger is used to start receiving the echo signal when the combined delay of the voltage-controlled delay unit ends; The second voltage-controlled delay unit is used to set a third delay time according to a third voltage value; The third trigger is used to trigger the corresponding channel when the delay of the second voltage-controlled delay unit ends, and simultaneously trigger the next second voltage-controlled delay unit to start working.

4. A picosecond delay accuracy control method for an electromagnetic ultrasonic phased array, characterized in that: The picosecond delay accuracy control method of the electromagnetic ultrasonic phased array is applied to the picosecond delay accuracy control device of the electromagnetic ultrasonic phased array according to any one of claims 1 to 3, and the picosecond delay accuracy control method of the electromagnetic ultrasonic phased array comprises: Obtaining parameters set by the host computer; the parameters include: emission timing, amplitude of the excitation waveform voltage and excitation frequency; converting the parameter into an electrical signal; Based on the fixed delay time and the electrical signal, an ultrasonic wave of corresponding time sequence is formed; Based on another fixed delay time, the echo signal of each channel is received in time sequence; the echo signal is a signal generated when the ultrasonic wave contacts the test piece; the echo signal includes defect information; Based on the echo signals of each channel, a detection result image is obtained.

5. The method for controlling picosecond delay accuracy of an electromagnetic ultrasonic phased array according to claim 4, characterized in that: Based on the fixed delay time and the electrical signal, an ultrasonic wave of corresponding time sequence is formed, specifically including: Performing high-voltage amplification processing on the electrical signal to obtain a high-voltage pulse signal; Setting a digital value of a first high-precision DAC voltage value; Based on the digital value of the first high-precision DAC voltage value, setting a first voltage value for each first voltage-controlled delay unit; According to the first voltage value, setting a first delay time; Based on the corresponding first delay time, the high-voltage pulse signal of the corresponding channel is triggered in time sequence to form an ultrasonic wave of the corresponding time sequence.

6. The method for controlling picosecond delay accuracy of an electromagnetic ultrasonic phased array according to claim 4, characterized in that: Based on another fixed delay time, the echo signals of each channel are received in sequence, specifically including: respectively setting the digital value of the second high-precision DAC voltage value and the digital value of the third high-precision DAC voltage value; Based on the digital value of the second high-precision DAC voltage value, setting a second voltage value for the voltage-controlled delay unit combination; According to the second voltage value, setting a second delay time; Based on the digital value of the third high-precision DAC voltage value, setting a third voltage value for each second voltage-controlled delay unit; According to the third voltage value, setting a third delay time; When the second delay time ends, the echo signals of each channel are received in time sequence based on the corresponding third delay time.

7. The method for controlling picosecond delay accuracy of an electromagnetic ultrasonic phased array according to claim 4, characterized in that: Based on the echo signals of each channel, a detection result image is obtained, which specifically includes: amplifying the echo signals of each channel to obtain amplified echo signals; filtering the amplified echo signal to obtain a filtered echo signal; Performing ADC conversion on the filtered echo signal to obtain a converted echo signal; Based on the converted echo signal, the echo amplitude is gradient matched according to the color to generate a detection result image.

8. The method for controlling picosecond delay accuracy of an electromagnetic ultrasonic phased array according to claim 7, characterized in that: Based on the converted echo signal, the echo amplitude is gradient matched according to the color to generate a detection result image, which specifically includes: Based on the converted echo signal, the echo amplitude is gradient matched according to the color, from the smallest to the largest, from red to blue, and displayed on the screen in the form of RGB to obtain a detection result image.

9. The method for controlling picosecond delay accuracy of an electromagnetic ultrasonic phased array according to claim 4, characterized in that: The picosecond delay accuracy control method of the electromagnetic ultrasonic phased array also includes: The parameters are cached.

10. The method for controlling picosecond delay accuracy of an electromagnetic ultrasonic phased array according to claim 4, characterized in that: The picosecond delay accuracy control method of the electromagnetic ultrasonic phased array also includes: The converted echo signal is buffered.

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