Ultrasonic radar echo envelope optimization circuit and optimization method

Abstract

Provided in the present application are an ultrasonic radar echo envelope optimization circuit and optimization method. The optimization circuit comprises an analog-to-digital conversion module, a signal demodulation module, an envelope signal optimization module and a controller. The analog-to-digital conversion module is used for converting an echo signal of a transducer from an analog signal into a digital signal. The signal demodulation module is used for generating an initial envelope signal on the basis of the echo signal that has been subjected to analog-to-digital conversion. The envelope signal optimization module is used for performing interference suppression on the initial envelope signal, so as to generate a target envelope signal. The controller is used for controlling an anti-interference coefficient of the envelope signal optimization module. The anti-interference coefficient is negatively correlated with the operating frequency of the transducer, positively correlated with the sampling frequency of the analog-to-digital conversion module, and positively correlated with a quality factor of a band-pass filter. The anti-interference coefficient can be dynamically adjusted on the basis of different combinations of the operating frequency of the transducer, the sampling frequency of the analog-to-digital conversion module and the quality factor of the band-pass filter, thereby improving the anti-interference capability of the target envelope signal.

Description

Ultrasonic radar echo envelope optimization circuit and optimization method Cross-reference of related applications

[0001] This patent application claims priority to Chinese Patent Application No. 202411930649.3, filed on December 25, 2024, entitled "Ultrasonic Radar Echo Envelope Optimization Circuit and Optimization Method", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of ultrasonic radar technology, and in particular to an ultrasonic radar echo envelope optimization circuit and optimization method. Background Technology

[0003] In an ultrasonic radar ranging system, the reflected ultrasonic waves are captured by a receiver, and the received signal is converted into an envelope signal through signal demodulation. The envelope signal is then compared with a set threshold to realize the function of echo detection of obstacles.

[0004] Because ultrasonic radar ranging systems operate in complex environments, they are subject to various environmental interference signals (such as raindrops). These interference signals can significantly impact the echo detection process, leading to increased misjudgments. Therefore, in ultrasonic radar obstacle detection systems, it is necessary to eliminate interference signals caused by environmental noise in order to more accurately identify the echoes of actual obstacles.

[0005] Current technology typically uses an analog differential amplifier circuit to suppress interference signals. However, analog differential amplifier circuits cannot adjust their coefficients for different schemes, resulting in poor anti-interference capabilities. Summary of the Invention

[0006] This application provides an ultrasonic radar echo envelope optimization circuit and optimization method to solve at least some of the problems in the related art.

[0007] This application provides an ultrasonic radar echo envelope optimization circuit, comprising: an analog-to-digital conversion module connected to the transducer for converting the echo signal from the transducer from an analog signal to a digital signal; a signal demodulation module connected to the analog-to-digital conversion module, the signal demodulation module including a bandpass filter for generating an initial envelope signal based on the echo signal after analog-to-digital conversion; an envelope signal optimization module connected to the signal demodulation module for suppressing interference in the initial envelope signal to generate a target envelope signal; and a controller connected to the envelope signal optimization module for controlling the anti-interference coefficient of the envelope signal optimization module, the anti-interference coefficient determining the interference suppression capability of the envelope signal optimization module; wherein the anti-interference coefficient is negatively correlated with the operating frequency of the transducer, positively correlated with the sampling frequency of the analog-to-digital conversion module, and positively correlated with the quality factor of the bandpass filter.

[0008] Optionally, the ultrasonic radar echo envelope optimization circuit further includes a switch connected between the signal demodulation module and the envelope signal optimization module. The controller is used to control the switch to control the on / off state between the signal demodulation module and the envelope signal optimization module.

[0009] Optionally, the envelope signal optimization module includes a subtractor, a first multiplier, a second multiplier, an adder, a first register, and a second register. One input of the subtractor is connected to the output of the signal demodulation module, used to input the initial envelope signal at the current moment into the subtractor. The other input of the subtractor is connected to the first register, which is connected to the signal demodulation module, used to input the initial envelope signal at the previous moment into the subtractor. The output of the subtractor is connected to one input of the first multiplier. The controller is connected to the other input of the first multiplier, used to input the anti-interference coefficient into the first multiplier. The controller is connected to one input of the second multiplier, used to input the anti-interference coefficient into the second multiplier. The other input of the second multiplier is connected to the second register, which is connected to the output of the adder, used to input the target envelope signal at the previous moment into the second multiplier. The outputs of the first multiplier and the second multiplier are both connected to the adder, and the output of the adder is used to output the target envelope signal.

[0010] Optionally, the first register stores the initial envelope signal from the previous moment.

[0011] Optionally, the second register stores the target envelope signal from the previous moment.

[0012] Optionally, the anti-interference coefficient Where A is the anti-interference coefficient, Q is the quality factor of the bandpass filter, Fc is the operating frequency of the transducer, and Fs is the sampling frequency of the analog-to-digital conversion module.

[0013] Optionally, the controller pre-stores a calibration table corresponding to the calibration anti-interference coefficient, calibration operating frequency, calibration sampling frequency, and calibration quality factor. The controller is used to select the calibration anti-interference coefficient corresponding to the calibration operating frequency, calibration sampling frequency, and calibration quality factor that are the same as the operating frequency, the sampling frequency, and the quality factor in the corresponding calibration table as the anti-interference coefficient.

[0014] This application also provides an ultrasonic radar echo envelope optimization method, comprising: converting the echo signal of a transducer from an analog signal to a digital signal; generating an initial envelope signal based on the echo signal after analog-to-digital conversion; controlling the anti-interference coefficient of the envelope signal optimization module, wherein the anti-interference coefficient is negatively correlated with the operating frequency of the transducer, positively correlated with the sampling frequency of the analog-to-digital conversion module, and positively correlated with the quality factor of the bandpass filter; and suppressing interference in the initial envelope signal through the envelope signal optimization module to generate the target envelope signal.

[0015] Optionally, the optimization method further includes: controlling the connection between the signal demodulation module and the envelope signal optimization module by controlling the on / off state of a switch connected between the signal demodulation module and the envelope signal optimization module.

[0016] Optionally, the step of suppressing interference in the initial envelope signal to generate the target envelope signal includes: subtracting the initial envelope signal at the current time from the initial envelope signal at the previous time, and multiplying the difference between the initial envelope signal at the current time and the initial envelope signal at the previous time and the anti-interference coefficient; multiplying the anti-interference coefficient and the target envelope signal at the previous time; adding the output values ​​of the two multiplication operations, and outputting the target envelope signal at the current time.

[0017] Optionally, the anti-interference coefficient Where A is the anti-interference coefficient, Q is the quality factor of the bandpass filter, Fc is the operating frequency of the transducer, and Fs is the sampling frequency of the analog-to-digital conversion module.

[0018] Optionally, the envelope signal optimization module performs smoothing processing on the initial envelope signal based on the exponentially weighted moving average method.

[0019] Optionally, the method further includes: pre-establishing a calibration table corresponding to the calibration anti-interference coefficient, calibration operating frequency, calibration sampling frequency, and calibration quality factor; the control of the anti-interference coefficient of the envelope signal optimization module includes: selecting the calibration anti-interference coefficient corresponding to the calibration operating frequency, calibration sampling frequency, and calibration quality factor that are the same as the operating frequency, the sampling frequency, and the quality factor in the corresponding calibration table as the anti-interference coefficient.

[0020] This application provides an ultrasonic radar echo envelope optimization circuit. By connecting a controller to an envelope signal optimization module, the circuit controls the anti-interference coefficient of the envelope signal optimization module. The anti-interference coefficient determines the interference suppression capability of the envelope signal optimization module. The anti-interference coefficient is negatively correlated with the transducer's operating frequency, positively correlated with the sampling frequency of the analog-to-digital converter module, and positively correlated with the quality factor of the bandpass filter. Different anti-interference coefficients can be obtained for different combinations of transducer operating frequencies, analog-to-digital converter sampling frequencies, and bandpass filter quality factors, achieving dynamic adjustment of the anti-interference coefficient of the envelope signal optimization module and improving its anti-interference capability. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0022] Figure 1 is a block diagram of an ultrasonic radar echo envelope optimization circuit according to an embodiment.

[0023] Figure 2 is a block diagram of an ultrasonic radar echo envelope optimization circuit according to another embodiment.

[0024] Figure 3 is a circuit diagram of one embodiment of the envelope signal optimization module in the ultrasonic radar echo envelope optimization circuit shown in Figure 1.

[0025] Figure 4 is a flowchart illustrating an ultrasonic radar echo envelope optimization method according to an embodiment.

[0026] Figure 5 is a flowchart illustrating one implementation of step 23 in the ultrasonic radar echo envelope optimization method shown in Figure 1.

[0027] Figure 6 is a flowchart illustrating another embodiment of the ultrasonic radar echo envelope optimization method.

[0028] Figure reference numerals: 1. Ultrasonic radar echo envelope optimization circuit; 11. Transducer; 12. Analog-to-digital conversion module; 13. Signal demodulation module; 14. Envelope signal optimization module; 15. Controller; 16. Switch; 131. Bandpass filter; 141. Subtractor; 142. First multiplier; 143. Second multiplier; 144. Adder; 145. First register; 146. Second register; 147. Comparator. Detailed Implementation

[0029] This application provides an ultrasonic radar echo envelope optimization circuit and an ultrasonic radar echo envelope optimization method. The ultrasonic radar echo envelope optimization circuit and method of this application will be described in detail below with reference to the accompanying drawings. Unless otherwise specified, the features in the following embodiments and implementations can be combined with each other.

[0030] Please refer to Figure 1, which is a block diagram of an ultrasonic radar echo envelope optimization circuit 1 according to an embodiment. As shown in Figure 1, the ultrasonic radar echo envelope optimization circuit 1 includes an analog-to-digital conversion module 12, a signal demodulation module 13, an envelope signal optimization module 14, and a controller 15.

[0031] The analog-to-digital conversion module 12 is connected to the transducer 11 and is used to convert the echo signal of the transducer 11 from an analog signal to a digital signal. The transducer 11 is an ultrasonic transducer. The transducer 11 vibrates under the excitation of a pulse drive signal to generate ultrasonic waves, which are then transmitted outward. When the transmitted ultrasonic waves encounter an obstacle, they return to the transducer 11. The wave returning to the transducer 11 is the echo. By detecting the echo, the presence and distance of the obstacle can be determined.

[0032] The analog-to-digital converter module 12 converts the echo signal from the transducer 11 from an analog signal to a digital signal. Digital signals have higher noise immunity than analog signals. In digital systems, signals can be protected and recovered using error correction codes and other methods, thereby reducing the impact of noise on signal quality. Furthermore, many computers and electronic devices are digital systems, making them more suitable for processing digital signals. Converting analog signals to digital signals facilitates interaction and processing with these digital systems.

[0033] The signal demodulation module 13 is connected to the analog-to-digital conversion module 12. The signal demodulation module 13 includes a bandpass filter 131, used to generate an initial envelope signal based on the echo signal after analog-to-digital conversion. The main function of the signal demodulation module 13 is to extract useful information, such as frequency and amplitude information, from the received signal. The signal demodulation module 13 includes key components such as the bandpass filter 131. The bandpass filter 131 can selectively pass signals within a specific frequency range while suppressing signals of other frequencies. In the signal demodulation module 13, the bandpass filter 131, through its frequency response characteristics, only allows signals within a specific frequency band to pass. When the echo signal passes through the bandpass filter 131, the filter filters out frequency components outside its passband, thereby retaining the envelope information corresponding to the desired signal frequency.

[0034] The envelope signal optimization module 14 is connected to the signal demodulation module 13 and is used to suppress interference in the initial envelope signal to generate the target envelope signal. Specifically, the envelope signal optimization module 14 can reduce the background noise of the initial envelope signal, such as high-frequency noise caused by raindrops, wind resistance, leaves, etc., so that the target envelope signal has a good anti-interference effect and avoids frequent alarms from the reversing radar caused by high-frequency noise such as raindrops, which would affect the driving experience.

[0035] The controller is connected to the envelope signal optimization module 14 and is used to control the anti-interference coefficient of the envelope signal optimization module 14. The anti-interference coefficient determines the interference suppression capability of the envelope signal optimization module 14. The larger the anti-interference coefficient, the stronger the interference suppression capability of the envelope signal optimization module 14. By controlling the anti-interference coefficient, the envelope signal optimization module 14 can achieve a balance between signal smoothing and response speed. The anti-interference coefficient is negatively correlated with the operating frequency of the transducer 11, positively correlated with the sampling frequency of the analog-to-digital conversion module 12, and positively correlated with the quality factor of the bandpass filter 131.

[0036] By connecting the controller 15 to the envelope signal optimization module 14, the anti-interference coefficient of the envelope signal optimization module 14 is controlled. The anti-interference coefficient determines the interference suppression capability of the envelope signal optimization module 14. The anti-interference coefficient is negatively correlated with the operating frequency of the transducer 11, positively correlated with the sampling frequency of the analog-to-digital converter module 12, and positively correlated with the quality factor of the bandpass filter 131. Different anti-interference coefficients can be obtained for different combinations of the operating frequency of the transducer 11, the sampling frequency of the analog-to-digital converter module 12, and the quality factor of the bandpass filter 131, thereby realizing the dynamic adjustment of the anti-interference coefficient of the envelope signal optimization module 14 and improving its anti-interference capability.

[0037] Please refer to Figure 2, which is a block diagram of the ultrasonic radar echo envelope optimization circuit 1 according to another embodiment. The embodiment shown in Figure 2 is basically the same as the embodiment shown in Figure 1. The difference is that in the embodiment shown in Figure 2, the ultrasonic radar echo envelope optimization circuit 1 further includes a switch 16, which is connected between the signal demodulation module 13 and the envelope signal optimization module 14. The controller 15 is used to control the switch 16 to control the on / off state between the signal demodulation module 13 and the envelope signal optimization module 14. The envelope signal optimization module 14 can be controlled by the switch 16 to operate, and the controller 15 can autonomously decide whether to turn on the envelope signal optimization module 14 according to the environmental conditions. For example, on a sunny day with no wind and no fallen leaves, when the factors affecting the reversing alarm in the environment are relatively small, the envelope signal optimization module 14 can be turned off. On rainy days, windy days, or days with many fallen leaves, the envelope signal optimization module 14 is turned on to avoid the influence of high-frequency noise in the environment on the ultrasonic radar envelope signal.

[0038] Please refer to Figure 3, which is a circuit diagram of one embodiment of the envelope signal optimization module 14 in the ultrasonic radar echo envelope optimization circuit 1 shown in Figure 1. In the embodiment shown in Figure 3, the envelope signal optimization module 14 includes a subtractor 141, a first multiplier 142, a second multiplier 143, an adder 144, a first register 145, and a second register 146. One input terminal of the subtractor 141 is connected to the output terminal of the signal demodulation module 13, and is used to input the initial envelope signal at the current moment into the subtractor 141. The other input terminal of the subtractor 141 is connected to the first register 145, which is connected to the signal demodulation module 13. The first register 145 can store the initial envelope signal at the previous moment, and is used to input the initial envelope signal at the previous moment into the subtractor 141. The output terminal of the subtractor 141 is connected to one input terminal of the first multiplier 142, and the controller is connected to the other input terminal of the first multiplier 142, used to input the anti-interference coefficient into the first multiplier 142.

[0039] The controller is connected to one input of the second multiplier 143 to input the anti-interference coefficient. The other input of the second multiplier 143 is connected to the second register 146. The second register 146 can store the target envelope signal from the previous time step. The second register 146 is connected to the output of the adder 144 to input the target envelope signal from the previous time step to the second multiplier 143. The outputs of the first multiplier 142 and the second multiplier 143 are both connected to the adder 144, and the output of the adder 144 is used to output the target envelope signal.

[0040] This envelope signal optimization module 14 can filter out high-frequency noise and smooth the initial envelope signal based on the exponentially weighted moving average method. The anti-interference coefficient controls the sensitivity of the envelope signal optimization module 14 and determines the trade-off between signal smoothing and response speed.

[0041] Adder 144 is connected to comparator 147 and is used to compare the target envelope signal with a set threshold through comparator 147. When the amplitude of the target envelope signal is greater than the set threshold, it indicates that there is an obstacle. If the amplitude of the target envelope signal is not greater than the set threshold, it indicates that there is no obstacle.

[0042] In this embodiment, the anti-interference coefficient Where A is the anti-interference coefficient, Q is the quality factor of the bandpass filter 131, Fc is the operating frequency of the transducer 11, and Fs is the sampling frequency of the analog-to-digital conversion module 12.

[0043] The operating frequency of transducer 11, also known as the resonant frequency of transducer 11, is the frequency of the sound wave emitted by transducer 11 during operation. The operating frequency of transducer 11 has a significant impact on the performance of transducer 11, such as its transmission power, receiving sensitivity, sound wave propagation distance in the medium, and resolution.

[0044] The sampling frequency of the analog-to-digital converter (ADC) 12 determines the speed and accuracy at which it can capture and convert analog signals. If the sampling frequency is too low, important information in the analog signal may be lost, resulting in aliasing distortion; conversely, if the sampling frequency is too high, it may increase the burden and cost of the converter. Generally, the sampling frequency Fs of the ADC 12 is greater than or equal to twice the operating frequency Fc.

[0045] Q is the quality factor of the bandpass filter 131, and it is an important indicator for measuring the frequency selectivity of the bandpass filter 131. The quality factor Q of the bandpass filter 131 is defined as the ratio of the center frequency f0 to the bandwidth BW. A larger quality factor Q indicates that the bandpass filter 131 has a narrower frequency response width, can better suppress signals of non-target frequencies, and has higher selectivity. Conversely, a smaller quality factor Q indicates that the bandpass filter 131 has a wider frequency response width, but lower selectivity. When selecting the quality factor Q, it is necessary to balance the relationship between selectivity and bandwidth. An excessively high Q value may lead to a narrow bandwidth, limiting the application range of the filter, while an excessively low Q value may reduce the selectivity of the filter and affect the filtering effect. The main controller will select different Q values ​​of the bandpass filter 131 for filtering according to different operating conditions. Specifically, the radar ranging chip can provide several bandwidth filter Q values ​​for the main control chip to configure. The larger the Q, the narrower the bandwidth, and the more obvious the effect of the filter in filtering out noise of other frequencies. The smaller the Q, the wider the bandwidth, and the larger the frequency range retained by the filter. Therefore, the main controller can dynamically adjust the Q value setting during use to adapt to different application environments. Specifically, the main controller chip can adjust the bandwidth of the bandpass filter 131 according to the length of the transmitted burst signal and the requirements for the echo signal.

[0046] In this embodiment, the controller 15 has a pre-stored calibration table corresponding to the calibration anti-interference coefficient, calibration working frequency, calibration sampling frequency and calibration quality factor. The controller 15 is used to select the calibration anti-interference coefficient corresponding to the calibration working frequency, calibration sampling frequency and calibration quality factor that are the same as the working frequency, sampling frequency and quality factor in the corresponding calibration table as the anti-interference coefficient.

[0047] Because of the anti-interference coefficient The calculation of the anti-interference coefficient requires division. Therefore, in the radar ranging chip design, the anti-interference coefficient can be calculated and tableted based on the frequencies of all supported transducers 11, the determined sampling frequency, and the quality factor of the bandpass filter 131 under different configurations. Specifically, the controller pre-stores a calibration table corresponding to the calibrated anti-interference coefficient, calibrated operating frequency, calibrated sampling frequency, and calibrated quality factor. The controller selects the calibrated anti-interference coefficient corresponding to the same calibrated operating frequency, calibrated sampling frequency, and calibrated quality factor as the anti-interference coefficient from the corresponding calibration table. In this way, different anti-interference coefficients can be determined based on different operating frequencies, sampling frequencies, and quality factors. This enables dynamic adjustment of the anti-interference coefficient of the envelope signal optimization module 14, improving its anti-interference capability.

[0048] This application also provides an ultrasonic radar echo envelope optimization method 20. Please refer to Figure 4, which is a flowchart illustrating an embodiment of the ultrasonic radar echo envelope optimization method. As shown in Figure 4, the ultrasonic radar echo envelope optimization method 20 includes steps 21 to 24.

[0049] Step 21: Convert the transducer's echo signal from an analog signal to a digital signal.

[0050] Step 22: Generate the initial envelope signal based on the echo signal after analog-to-digital conversion.

[0051] Step 23: Control the anti-interference coefficient of the envelope signal optimization module. The anti-interference coefficient is negatively correlated with the operating frequency of the transducer, positively correlated with the sampling frequency of the analog-to-digital conversion module, and positively correlated with the quality factor of the bandpass filter.

[0052] Step 24: The initial envelope signal is suppressed by the envelope signal optimization module to generate the target envelope signal.

[0053] Thus, by controlling the anti-interference coefficient of the envelope signal optimization module, which is negatively correlated with the transducer's operating frequency, positively correlated with the sampling frequency of the analog-to-digital conversion module, and positively correlated with the quality factor of the bandpass filter, different anti-interference coefficients can be determined based on different operating frequencies, sampling frequencies, and quality factors. This enables dynamic adjustment of the anti-interference coefficient of the envelope signal optimization module, thereby improving its anti-interference capability.

[0054] In some embodiments, the optimization method 20 further includes controlling the on / off state of the signal demodulation module and the envelope signal optimization module by controlling the on / off state of a switch connected between the signal demodulation module and the envelope signal optimization module. The envelope signal optimization module can be controlled by a switch to operate, and the controller autonomously decides whether to activate the envelope signal optimization module based on environmental conditions. For example, on a sunny day with no wind and no fallen leaves, when environmental factors affecting the reversing alarm are relatively small, the envelope signal optimization module can be turned off. On rainy days, windy days, or days with many fallen leaves, the envelope signal optimization module is activated to avoid the influence of high-frequency noise in the environment on the ultrasonic radar envelope signal.

[0055] Please refer to Figure 5, which is a flowchart illustrating one embodiment of step 24 in the ultrasonic radar echo envelope optimization method shown in Figure 1. In the embodiment shown in Figure 5, step 24 uses an envelope signal optimization module to suppress interference in the initial envelope signal and generate a target envelope signal, including steps 241 to 243.

[0056] Step 241: Subtract the initial envelope signal at the current time from the initial envelope signal at the previous time, and multiply the difference between the initial envelope signal at the current time and the initial envelope signal at the previous time and the anti-interference coefficient.

[0057] Step 242: Multiply the anti-interference coefficient and the target envelope signal from the previous time step.

[0058] Step 243: Add the output values ​​of the two multiplication operations together and output the target envelope signal at the current time.

[0059] The generated target envelope signal can filter out high-frequency noise. Based on the exponentially weighted moving average method, the initial envelope signal is smoothed. The anti-interference coefficient controls the sensitivity of the envelope signal optimization module, determining the trade-off between signal smoothing and response speed.

[0060] In this embodiment, the anti-interference coefficient Where A is the anti-interference coefficient, Q is the quality factor of the bandpass filter, Fc is the operating frequency of the transducer, and Fs is the sampling frequency of the analog-to-digital conversion module.

[0061] Please refer to Figure 6, which is a flowchart illustrating another embodiment of the ultrasonic radar echo envelope optimization method. In the embodiment shown in Figure 6, the optimization method further includes step 25: pre-establishing a calibration table corresponding to the calibration anti-interference coefficient, calibration operating frequency, calibration sampling frequency, and calibration quality factor. Because the anti-interference coefficient... The calculation of the anti-interference coefficient requires division. Therefore, in the radar ranging chip design, the anti-interference coefficient can be calculated and tabulated based on all supported transducer frequencies, the determined sampling frequency, and the quality factor of the bandpass filter under different configurations. In other words, the controller pre-stores a calibration table corresponding to the calibrated anti-interference coefficient, calibrated operating frequency, calibrated sampling frequency, and calibrated quality factor.

[0062] Step 23 controls the anti-interference coefficient of the envelope signal optimization module, including: selecting the calibration anti-interference coefficient corresponding to the same calibration working frequency, calibration sampling frequency, and calibration quality factor as the operating frequency, sampling frequency, and quality factor from the corresponding calibration table. In this way, different anti-interference coefficients can be determined according to different operating frequencies, sampling frequencies, and quality factors. This enables dynamic adjustment of the anti-interference coefficient of the envelope signal optimization module, improving its anti-interference capability.

[0063] This application provides an ultrasonic radar echo envelope optimization circuit and method. By controlling the anti-interference coefficient of the envelope signal optimization module, the anti-interference coefficient determines the interference suppression capability of the envelope signal optimization module. The anti-interference coefficient is negatively correlated with the transducer's operating frequency, positively correlated with the sampling frequency of the analog-to-digital converter module, and positively correlated with the quality factor of the bandpass filter. Different anti-interference coefficients can be obtained for different combinations of transducer operating frequencies, analog-to-digital converter sampling frequencies, and bandpass filter quality factors, realizing dynamic adjustment of the anti-interference coefficient of the envelope signal optimization module and improving its anti-interference capability.

[0064] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0065] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. An ultrasonic radar echo envelope optimization circuit, characterized in that, include: An analog-to-digital converter module, connected to the transducer, is used to convert the echo signal from the transducer from an analog signal to a digital signal; A signal demodulation module is connected to the analog-to-digital conversion module. The signal demodulation module includes a bandpass filter for generating an initial envelope signal based on the echo signal after analog-to-digital conversion. An envelope signal optimization module, connected to the signal demodulation module, is used to suppress interference in the initial envelope signal and generate a target envelope signal. A controller, connected to the envelope signal optimization module, is used to control the anti-interference coefficient of the envelope signal optimization module. The anti-interference coefficient determines the interference suppression capability of the envelope signal optimization module. The anti-interference coefficient is negatively correlated with the operating frequency of the transducer, positively correlated with the sampling frequency of the analog-to-digital conversion module, and positively correlated with the quality factor of the bandpass filter.

2. The ultrasonic radar echo envelope optimization circuit according to claim 1, characterized in that, The ultrasonic radar echo envelope optimization circuit also includes a switch connected between the signal demodulation module and the envelope signal optimization module. The controller is used to control the switch to control the on / off state between the signal demodulation module and the envelope signal optimization module.

3. The ultrasonic radar echo envelope optimization circuit according to claim 1, characterized in that, The envelope signal optimization module includes a subtractor, a first multiplier, a second multiplier, an adder, a first register, and a second register. One input of the subtractor is connected to the output of the signal demodulation module, used to input the initial envelope signal at the current moment into the subtractor. The other input of the subtractor is connected to the first register, which is connected to the signal demodulation module, used to input the initial envelope signal at the previous moment into the subtractor. The output of the subtractor is connected to one of the inputs of the first multiplier. The controller is connected to the other input of the first multiplier, used to input the anti-interference coefficient into the first multiplier. The controller is connected to one input terminal of the second multiplier to input the anti-interference coefficient to the second multiplier. The other input terminal of the second multiplier is connected to the second register, and the second register is connected to the output terminal of the adder to input the target envelope signal of the previous moment to the second multiplier. The outputs of the first multiplier and the second multiplier are both connected to the adder, and the output of the adder is used to output the target envelope signal.

4. The ultrasonic radar echo envelope optimization circuit according to claim 3, characterized in that, The first register stores the initial envelope signal from the previous moment.

5. The ultrasonic radar echo envelope optimization circuit according to claim 3, characterized in that, The second register stores the target envelope signal from the previous moment.

6. The ultrasonic radar echo envelope optimization circuit according to claim 1, characterized in that, The anti-interference coefficient Where A is the anti-interference coefficient, Q is the quality factor of the bandpass filter, Fc is the operating frequency of the transducer, and Fs is the sampling frequency of the analog-to-digital conversion module.

7. The ultrasonic radar echo envelope optimization circuit according to claim 1, characterized in that, The envelope signal optimization module smooths the initial envelope signal based on the exponentially weighted moving average method.

8. The ultrasonic radar echo envelope optimization circuit according to claim 1, characterized in that, The controller has a pre-stored calibration table corresponding to the calibration anti-interference coefficient, calibration working frequency, calibration sampling frequency, and calibration quality factor. The controller is used to select the calibration anti-interference coefficient corresponding to the calibration working frequency, calibration sampling frequency, and calibration quality factor that are the same as the working frequency, the sampling frequency, and the quality factor in the corresponding calibration table as the anti-interference coefficient.

9. A method for optimizing the echo envelope of ultrasonic radar, characterized in that, The optimization method includes: Convert the transducer's echo signal from an analog signal to a digital signal; The initial envelope signal is generated based on the echo signal after analog-to-digital conversion; The anti-interference coefficient of the control envelope signal optimization module is negatively correlated with the operating frequency of the transducer, positively correlated with the sampling frequency of the analog-to-digital conversion module, and positively correlated with the quality factor of the bandpass filter. The initial envelope signal is subjected to interference suppression by the envelope signal optimization module to generate the target envelope signal.

10. The ultrasonic radar echo envelope optimization method according to claim 9, characterized in that, The optimization method further includes: The connection between the signal demodulation module and the envelope signal optimization module is controlled by controlling the on / off state of the switch connected between them.

11. The ultrasonic radar echo envelope optimization method according to claim 9, characterized in that, The step of suppressing interference in the initial envelope signal to generate the target envelope signal includes: Subtract the initial envelope signal at the current time from the initial envelope signal at the previous time, and multiply the difference between the initial envelope signal at the current time and the initial envelope signal at the previous time and the anti-interference coefficient. Perform a multiplication operation between the anti-interference coefficient and the target envelope signal from the previous time step; The output values ​​of the two multiplication operations are added together, and the target envelope signal at the current time is output.

12. The ultrasonic radar echo envelope optimization method according to claim 11, characterized in that, The anti-interference coefficient Where A is the anti-interference coefficient, Q is the quality factor of the bandpass filter, Fc is the operating frequency of the transducer, and Fs is the sampling frequency of the analog-to-digital conversion module.

13. The ultrasonic radar echo envelope optimization method according to claim 9, characterized in that, The method further includes: pre-establishing a calibration table corresponding to the calibration anti-interference coefficient, calibration working frequency, calibration sampling frequency, and calibration quality factor.

14. The ultrasonic radar echo envelope optimization method according to claim 13, characterized in that, The anti-interference coefficient of the control envelope signal optimization module includes: selecting the calibration anti-interference coefficient corresponding to the calibration working frequency, calibration sampling frequency and calibration quality factor that are the same as the working frequency, the sampling frequency and the quality factor in the corresponding calibration table as the anti-interference coefficient.

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