An ultrasonic radar speed measurement method, speed measurement circuit and electronic device
By performing low-noise amplification and analog-to-digital conversion on the ultrasonic echo signal, and using the bandpass filter in the frequency shift extraction unit to extract the Doppler frequency shift, the delay and accuracy problems of ultrasonic radar velocity measurement are solved, and fast and accurate velocity calculation is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- INST OF FLEXIBLE ELECTRONICS TECH OF THU ZHEJIANG
- Filing Date
- 2025-12-04
- Publication Date
- 2026-07-03
AI Technical Summary
Existing ultrasonic radar technology struggles to measure the speed of target objects quickly and accurately, especially in autonomous driving and robot navigation, where traditional methods suffer from large computational delays and low accuracy.
By performing low-noise amplification and analog-to-digital conversion on the ultrasonic echo signal reflected by the target object, and using multiple parallel bandpass filters in the frequency shift extraction unit to extract the Doppler frequency shift, the velocity of the target object can be directly calculated, avoiding the problems of low velocity accuracy caused by delays and inaccurate ranging in traditional methods.
It achieves rapid and accurate determination of target objects, improving real-time performance and precision, and is suitable for collision warning and decision-making in autonomous driving and robot navigation.
Smart Images
Figure CN122330896A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of ultrasonic speed measurement, and more particularly to an ultrasonic radar speed measurement method, speed measurement circuit, and electronic equipment. Background Technology
[0002] Ultrasonic radar is widely used in automotive reversing radar, autonomous driving assistance systems, robot navigation, and industrial inspection. It primarily calculates the distance to a target object by measuring the flight time of an ultrasonic pulse from its emission to its reflection and reception. In practical applications, besides distance information, the target object's speed is also crucial. For example, in autonomous driving or robot navigation scenarios, quickly and accurately determining the approaching or receding speed of obstacles is essential for collision warning and decision-making. Therefore, there is an urgent need for an ultrasonic radar technology solution capable of quickly and accurately measuring the speed of target objects. Summary of the Invention
[0003] This disclosure provides an ultrasonic radar speed measurement method, speed measurement circuit, and electronic device to at least solve the above-mentioned technical problems existing in the prior art.
[0004] According to a first aspect of this disclosure, an ultrasonic radar velocity measurement method is provided, comprising: amplifying an ultrasonic echo signal reflected by a target object with low noise; performing analog-to-digital conversion on the amplified ultrasonic echo signal to obtain a digital echo signal; inputting the digital echo signal to a frequency shift extraction unit, wherein a bandpass filter in the frequency shift extraction unit filters the digital echo signal; the frequency shift extraction unit includes multiple parallel bandpass filters, each bandpass filter having a center frequency corresponding to a Doppler frequency shift; determining the target Doppler frequency shift corresponding to the digital echo signal based on the output signal amplitude of the bandpass filter; and determining the velocity of the target object based on the target Doppler frequency shift.
[0005] In one embodiment, filtering the digital echo signal by the bandpass filter in the frequency shift extraction unit includes: if the target object is stationary, the digital echo signal passes through a bandpass filter in the frequency shift extraction unit where the Doppler frequency shift is zero; if the target object is moving, the digital echo signal passes through a bandpass filter in the frequency shift extraction unit where the matching degree between the Doppler frequency shift and the frequency shift of the digital echo signal is greater than a first threshold.
[0006] In one possible implementation, determining the target Doppler frequency shift corresponding to the digital echo signal based on the output signal amplitude of the bandpass filter includes: in response to the fact that the output signal amplitude of only one bandpass filter is greater than a second threshold, the center frequency of the bandpass filter is determined as the target Doppler frequency shift.
[0007] In one possible implementation, determining the target Doppler frequency shift corresponding to the digital echo signal based on the output signal amplitude of the bandpass filter includes: in response to the existence of multiple adjacent bandpass filters whose output signal amplitudes are greater than a second threshold, determining the ratio of the output signal amplitudes of the multiple bandpass filters; and determining the target Doppler frequency shift corresponding to the digital echo signal based on the output signal amplitude ratio and the center frequencies of the multiple bandpass filters.
[0008] In one possible implementation, determining the velocity of the target object based on the target Doppler frequency shift includes: determining the velocity of the target object based on the target Doppler frequency shift, the speed of sound, and the ultrasonic emission frequency.
[0009] According to a second aspect of this disclosure, an ultrasonic radar speed measurement circuit is provided, comprising: a signal amplification unit for low-noise amplification of ultrasonic echo signals reflected by a target object; an analog-to-digital conversion unit for performing analog-to-digital conversion processing on the amplified ultrasonic echo signal to obtain a digital echo signal; a frequency shift extraction unit comprising multiple parallel bandpass filters, each bandpass filter having a center frequency corresponding to a Doppler frequency shift, for filtering the digital echo signal based on the bandpass filters; a frequency shift detection unit for monitoring the output signal amplitude of each bandpass filter and determining the target Doppler frequency shift corresponding to the digital echo signal based on the output signal amplitude of the bandpass filters; and a speed calculation unit for determining the speed of the target object based on the target Doppler frequency shift.
[0010] In one embodiment, the frequency shift extraction unit is further configured to: if the target object is stationary, the digital echo signal passes through a bandpass filter in the frequency shift extraction unit where the Doppler frequency shift is zero; if the target object is moving, the digital echo signal passes through a bandpass filter in the frequency shift extraction unit where the matching degree between the Doppler frequency shift and the frequency shift of the digital echo signal is greater than a first threshold.
[0011] In one embodiment, the frequency shift detection unit is further configured to: determine the center frequency of the bandpass filter as the target Doppler frequency shift in response to the fact that the amplitude of the output signal of only one bandpass filter is greater than the second threshold.
[0012] In one embodiment, the frequency shift detection unit is further configured to: determine the ratio of the output signal amplitudes of the multiple adjacent bandpass filters in response to the existence of multiple bandpass filters having output signal amplitudes greater than a second threshold; and determine the target Doppler frequency shift corresponding to the digital echo signal based on the output signal amplitude ratio and the center frequencies of the multiple bandpass filters.
[0013] According to a third aspect of this disclosure, an electronic device is provided, including the ultrasonic radar speed measurement circuit described in this disclosure.
[0014] This disclosure discloses an ultrasonic radar velocity measurement method, circuit, and electronic device. The method involves low-noise amplification and analog-to-digital conversion of the ultrasonic echo signal reflected from a target to obtain a digital echo signal. This digital echo signal is then input into a frequency shift extraction unit, which includes multiple parallel bandpass filters. The center frequency of each bandpass filter corresponds to a specific Doppler frequency shift. By monitoring the output signal amplitude of each bandpass filter, the Doppler frequency shift of the target object can be determined, and thus the velocity of the target object can be calculated. Therefore, by extracting the Doppler frequency shift of the ultrasonic echo signal through bandpass filters and directly calculating the velocity of the target object based on the Doppler frequency shift, this method avoids the time delay problem of traditional velocity measurement methods that require multiple distance measurements and velocity calculations based on distance. Furthermore, the Doppler frequency shift can be detected, improving its accuracy and further enhancing the accuracy of the target object velocity calculation.
[0015] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description
[0016] The above and other objects, features, and advantages of this disclosure will become readily apparent from the following detailed description of exemplary embodiments, taken in conjunction with the accompanying drawings. Several embodiments of this disclosure are illustrated in the drawings by way of example and not limitation, in which: In the accompanying drawings, the same or corresponding reference numerals indicate the same or corresponding parts.
[0017] Figure 1 A flowchart illustrating an ultrasonic radar velocity measurement method according to an embodiment of this disclosure is shown. Figure 2 A schematic diagram of the structure of an ultrasonic radar speed measurement circuit according to an embodiment of the present disclosure is shown. Figure 1 ; Figure 3 A schematic diagram of the structure of an ultrasonic radar speed measurement circuit according to an embodiment of the present disclosure is shown. Figure 2 . Detailed Implementation
[0018] To make the objectives, features, and advantages of this disclosure more apparent and understandable, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.
[0019] Figure 1 A flowchart illustrating an ultrasonic radar velocity measurement method according to an embodiment of this disclosure is shown, as follows: Figure 1 As shown, an ultrasonic radar speed measurement method includes: Step S101: Amplify the ultrasonic echo signal reflected by the target object with low noise.
[0020] In this embodiment, the ultrasonic echo signal is the signal reflected back to the ultrasonic transducer by the target object after the ultrasonic signal emitted by the transducer encounters the target object; the target object can be a vehicle, obstacle, human body, etc. The ultrasonic echo signal reflected from the target object is usually very weak, with an amplitude possibly only at the millivolt level. Therefore, it is necessary to amplify the ultrasonic echo signal to a level suitable for subsequent processing. A low-noise amplifier (LNA) can be used to amplify the ultrasonic echo signal reflected from the target object. Low-noise amplification refers to increasing the amplitude of the ultrasonic echo signal to a level suitable for subsequent processing while minimizing the introduction of noise. For example, assuming the initial amplitude of the ultrasonic echo signal is 10mV, after amplification, the signal amplitude can be increased to about 1V, thus ensuring that the signal can be processed subsequently.
[0021] Step S102: Perform analog-to-digital conversion on the amplified ultrasonic echo signal to obtain a digital echo signal.
[0022] In this embodiment, the amplified ultrasonic echo signal can be processed using an analog-to-digital converter (ADC). The purpose of ADC is to convert a continuous analog signal into discrete digital signals, each representing the amplitude value of the signal at a specific moment, for subsequent processing and analysis. The sampling rate of the ADC is typically much higher than the frequency of the ultrasonic echo signal to satisfy the Nyquist theorem. For example, if the frequency of the ultrasonic echo signal is 40 kHz, the sampling rate of the ADC can be set to 200 kHz or higher.
[0023] Step S103: The digital echo signal is input to the frequency shift extraction unit, and the bandpass filter in the frequency shift extraction unit filters the digital echo signal.
[0024] In this embodiment, the digital echo signal also needs to be input to the frequency shift extraction unit. The frequency shift extraction unit consists of multiple parallel bandpass filters, each with a center frequency corresponding to a specific Doppler frequency shift, and the Doppler frequency shift corresponding to the center frequency of each bandpass filter is different. After the digital echo signal is input to the frequency shift extraction unit, it enters a bandpass filter that matches the frequency shift of the digital echo signal, thereby effectively separating the signal components with different Doppler frequency shifts.
[0025] Step S104: Determine the target Doppler frequency shift corresponding to the digital echo signal based on the output signal amplitude of the bandpass filter.
[0026] In this embodiment, the output signal amplitude of each bandpass filter in the frequency shift extraction unit reflects the degree of matching between the digital echo signal and the Doppler frequency shift corresponding to the bandpass filter. By monitoring these output signal amplitudes, the target Doppler frequency shift corresponding to the digital echo signal can be determined. For example, if the output signal amplitude of a certain bandpass filter is significantly higher than that of other filters, it indicates that the Doppler frequency shift of the digital echo signal best matches the Doppler frequency shift corresponding to that bandpass filter, and the Doppler frequency shift corresponding to that bandpass filter can be determined as the target Doppler frequency shift.
[0027] Step S105: Determine the velocity of the target object based on the target Doppler frequency shift.
[0028] In this embodiment, the velocity of the target object can be determined based on the extracted target Doppler frequency shift. When there is relative motion between the target object and the ultrasonic radar, the reflected ultrasonic echo signal will generate a Doppler frequency shift. That is, the target Doppler frequency shift corresponding to the digital echo signal is a parameter directly related to the velocity of the target object, and the velocity of the target object can be directly determined based on the target Doppler frequency shift.
[0029] In traditional methods, ultrasonic radar typically acquires the velocity of a target object by performing post-processing calculations based on multiple distance measurements. For example, the system needs to continuously measure the distance d1, d2, d3, ... between itself and the target object at different time points t1, t2, t3, ..., and then estimate the average velocity v of the target object by calculating the ratio of the distance difference to the time difference between adjacent time points. However, traditional solutions have at least the following technical drawbacks: Large computational latency: To obtain an effective velocity estimate, the system must complete at least two full ranging cycles. This introduces an inherent latency of at least one ranging cycle (typically tens to hundreds of milliseconds). For high-speed moving targets or applications requiring rapid response (such as emergency braking), this latency is unacceptable and severely impacts the system's real-time performance and safety limits.
[0030] Low speed measurement accuracy: The accuracy of traditional methods directly depends on the accuracy of distance measurement. Ultrasonic ranging is inherently susceptible to interference from various factors such as temperature, humidity, and the characteristics of the target's reflective surface, resulting in a certain degree of measurement error. When differential calculations are performed on these inherently inaccurate distance values, the small errors in distance measurement are amplified, leading to a low signal-to-noise ratio, large fluctuations, and poor accuracy in the final calculated speed value. Especially under low-speed or uniform motion conditions, the distance change is very small, and the speed estimate is almost completely overwhelmed by noise, significantly reducing reliability.
[0031] To address the technical problems of traditional methods, this disclosure utilizes the Doppler frequency shift, which is directly related to the target's velocity, to calculate the target's speed. First, the ultrasonic echo signal reflected from the target is amplified with low noise and converted from analog to digital to obtain a digital echo signal. Then, the digital echo signal is input into a frequency shift extraction unit, which contains multiple parallel bandpass filters. The center frequency of each bandpass filter corresponds to a specific Doppler frequency shift. By monitoring the output signal amplitude of each bandpass filter, the Doppler frequency shift of the target object can be determined, and thus the target object's speed can be calculated. Therefore, by extracting the Doppler frequency shift of the ultrasonic echo signal through bandpass filters and directly calculating the target object's speed based on the Doppler frequency shift, this method avoids the time delay problem of traditional speed measurement methods that require multiple distance measurements and speed calculations based on distance. It also avoids the problem of low speed accuracy due to inaccurate distance measurements. This method can quickly and accurately determine the target object's speed, exhibiting significant advantages in real-time performance and high precision.
[0032] In another embodiment, step S103, "filtering the digital echo signal by the bandpass filter in the frequency shift extraction unit," includes: If the target object is stationary, the digital echo signal passes through a bandpass filter in the frequency shift extraction unit where the Doppler frequency shift is zero; if the target object is moving, the digital echo signal passes through a bandpass filter in the frequency shift extraction unit where the matching degree between the Doppler frequency shift and the frequency shift of the digital echo signal is greater than a first threshold.
[0033] In this embodiment, when the target object is stationary, the frequency of its reflected ultrasonic echo signal is the same as the transmission frequency, and no Doppler frequency shift occurs. In this case, the digital echo signal will primarily pass through the bandpass filter in the frequency shift extraction unit, which has zero Doppler frequency shift. For example, assuming the ultrasonic transmission frequency is 40 kHz, when the target is stationary, the frequency of the echo signal is also 40 kHz. At this time, the bandpass filter with a center frequency of 40 kHz in the frequency shift extraction unit will output a stronger signal amplitude, while the output amplitude of bandpass filters at other frequencies will be relatively weaker.
[0034] In this embodiment, when the target object is in motion, the reflected ultrasonic echo signal will experience a Doppler frequency shift, deviating from the transmission frequency. At this time, the digital echo signal will pass through the bandpass filter in the frequency shift extraction unit that has the highest matching degree with the actual Doppler frequency shift (i.e., a matching degree greater than a first threshold). For example, assuming the target object approaches the ultrasonic radar at a certain speed, the frequency of the echo signal may change from 40 kHz to 40.1 kHz. The bandpass filter in the frequency shift extraction unit with a center frequency of 40.1 kHz will effectively filter this frequency component and output a stronger signal amplitude.
[0035] In this disclosure, when the target is stationary, the echo signal frequency is the same as the transmission frequency, and it mainly passes through a bandpass filter with zero Doppler frequency shift. However, when the target moves, the echo signal will generate a Doppler frequency shift, and it passes through a bandpass filter with a high degree of matching to the actual frequency shift. Therefore, based on the bandpass filter with an output signal, the Doppler frequency shift corresponding to the digital echo signal can be preliminarily determined.
[0036] In another embodiment, step S104, "determining the target Doppler frequency shift corresponding to the digital echo signal based on the output signal amplitude of the bandpass filter," includes: If the output signal amplitude of only one bandpass filter is greater than the second threshold, then the center frequency of that bandpass filter is determined as the target Doppler shift.
[0037] In this embodiment, after the multiple bandpass filters in the frequency shift extraction unit filter the digital echo signal, it is also necessary to monitor the output signal amplitude of each bandpass filter in real time, and determine the target Doppler frequency shift corresponding to the digital echo signal based on the output signal amplitude of the bandpass filters. If, at a certain moment, the output signal amplitude of only one bandpass filter exceeds a preset second threshold, this indicates that the center frequency of the bandpass filter is highly matched with the actual Doppler frequency shift of the echo signal reflected by the target object. For example, assuming there are multiple bandpass filters in the frequency shift extraction unit with center frequencies of 10 Hz, 20 Hz, 30 Hz, etc., when the target object moves at a certain speed, its Doppler frequency shift may be 20 Hz. At this time, the output signal amplitude of the bandpass filter with a center frequency of 20 Hz will be significantly higher than the output amplitude of other filters (exceeding the second threshold). In this case, the center frequency (20 Hz) of the bandpass filter can be determined as the target Doppler frequency shift.
[0038] In this disclosure, by setting a second threshold, the system can effectively determine the actual Doppler frequency shift signal, thereby improving the accuracy and reliability of the target Doppler frequency shift signal.
[0039] In another embodiment, step S104, "determining the target Doppler frequency shift corresponding to the digital echo signal based on the output signal amplitude of the bandpass filter," includes: In response to the existence of multiple adjacent bandpass filters whose output signal amplitudes are greater than a second threshold, the ratio of the output signal amplitudes of the multiple bandpass filters is determined; based on the ratio of the output signal amplitudes and the center frequencies of the multiple bandpass filters, the target Doppler frequency shift corresponding to the digital echo signal is determined.
[0040] In this embodiment, after the multiple bandpass filters in the frequency shift extraction unit filter the digital echo signal, the output signal amplitude of each bandpass filter is monitored in real time. If, at a certain moment, the output signal amplitudes of multiple adjacent bandpass filters simultaneously exceed a preset second threshold, this indicates that the Doppler frequency shift of the target object may be located between the center frequencies of these adjacent filters. For example, assuming there are multiple bandpass filters in the frequency shift extraction unit with center frequencies of 10 Hz, 20 Hz, 30 Hz, etc., when the Doppler frequency shift of the target object is 15 Hz, the output signal amplitudes of the bandpass filters with center frequencies of 10 Hz and 20 Hz may simultaneously exceed the second threshold. In this case, it is necessary to further determine the ratio of the output signal amplitudes of these two bandpass filters in order to more accurately estimate the target Doppler frequency shift.
[0041] After determining the output signal amplitude ratios of several adjacent bandpass filters, it is necessary to accurately estimate the target Doppler frequency shift based on these ratios and the filter center frequencies using a pre-defined interpolation algorithm. For example, suppose the output signal amplitudes of bandpass filters with center frequencies of 10 Hz and 20 Hz are A1 and A2, respectively, and the ratio of A1 to A2 is 0.6. According to the interpolation algorithm, the precise value of the target Doppler frequency shift can be calculated. If the ratio of A1 to A2 is close to 1, it indicates that the target Doppler frequency shift is closer to the midpoint between these two center frequencies; if the ratio deviates significantly from 1, it indicates that the target Doppler frequency shift is closer to one of the center frequencies. Therefore, the target Doppler frequency shift can be estimated with higher accuracy, even if the target Doppler frequency shift does not perfectly match the center frequency of any of the bandpass filters.
[0042] In another embodiment, step S105, "determining the velocity of the target object based on the target Doppler frequency shift," includes: The velocity of the target object is determined based on the target Doppler frequency shift, sound velocity, and ultrasonic emission frequency.
[0043] In this embodiment, the target Doppler frequency shift is obtained. Next, it is necessary to use the target's Doppler frequency shift value, combined with the known speed of sound. and ultrasonic emission frequency The velocity of the target object is calculated using the Doppler frequency shift formula. v The Doppler frequency shift formula is:
[0044] in, It could be the radial velocity of the target object. The speed is 340 m / s under standard atmospheric conditions.
[0045] In practical applications, the system will use the calculated velocity value v The output is sent to the main controller for subsequent decision-making and control. For example, in the field of intelligent robots, the velocity value v is a key basis for robot navigation and obstacle avoidance. When service robots move in scenarios such as shopping malls and hospitals, they obtain the radial velocity v of targets such as pedestrians and pillars through ultrasonic radar. The main controller can predict the direction of target movement and collision risk. If a pedestrian is detected approaching the robot at 0.5 m / s, the system will plan an alternative path in advance or stop moving. In adaptive cruise control systems, the main controller combines the radial velocity v of the vehicle in front with the real-time distance between the two vehicles to dynamically adjust the throttle and brakes of its own vehicle. In automatic parking scenarios, if surrounding obstacles (such as curbs or other vehicles) are detected to have a slow-moving trend, the v value can help determine the trajectory of the obstacle and prevent scratches during parking.
[0046] Figure 2A schematic diagram of the structure of an ultrasonic radar speed measurement circuit according to an embodiment of the present disclosure is shown. Figure 1 ; Figure 3 A schematic diagram of the structure of an ultrasonic radar speed measurement circuit according to an embodiment of the present disclosure is shown. Figure 2 ,like Figure 2 and Figure 3 As shown, an ultrasonic radar speed measurement circuit includes: The signal amplification unit 10 is used to amplify the ultrasonic echo signal reflected by the target object with low noise. The signal amplification unit 10 may include a low noise amplifier.
[0047] The analog-to-digital conversion unit 20 is used to perform analog-to-digital conversion processing on the amplified ultrasonic echo signal to obtain a digital echo signal. The analog-to-digital conversion unit 20 may include an analog-to-digital converter.
[0048] The frequency shift extraction unit 30 includes multiple parallel bandpass filters, each with a center frequency corresponding to a Doppler frequency shift, used for filtering digital echo signals based on the bandpass filters. Figure 3 In the frequency shift extraction unit 30, there are parallel bandpass filters 1, 2, ..., n, and the Doppler frequency shift corresponding to the center frequency of each bandpass filter is different. The frequency shift detection unit 40 is used to monitor the output signal amplitude of each bandpass filter and determine the target Doppler frequency shift corresponding to the digital echo signal based on the output signal amplitude of the bandpass filter.
[0049] The velocity calculation unit 50 is used to determine the velocity of the target object based on the target Doppler frequency shift.
[0050] In another embodiment, the frequency shift extraction unit 30 is further configured to: If the target object is stationary, the digital echo signal passes through the bandpass filter in the frequency shift extraction unit 30 where the Doppler frequency shift is zero; If the target object is running, the digital echo signal passes through a bandpass filter in the frequency shift extraction unit 30 where the matching degree between the Doppler frequency shift and the frequency shift of the digital echo signal is greater than a first threshold.
[0051] In another embodiment, the frequency shift detection unit 40 is further configured to: If the output signal amplitude of only one bandpass filter is greater than the second threshold, then the center frequency of that bandpass filter is determined as the target Doppler shift.
[0052] In another embodiment, the frequency shift detection unit 40 is further configured to: In response to the existence of multiple adjacent bandpass filters whose output signal amplitudes are greater than the second threshold, the ratio of the output signal amplitudes of the multiple bandpass filters is determined. The target Doppler frequency shift corresponding to the digital echo signal is determined based on the output signal amplitude ratio and the center frequencies of multiple bandpass filters.
[0053] In another embodiment, the speed calculation unit 50 is further configured to: The velocity of the target object is determined based on the target Doppler frequency shift, sound velocity, and ultrasonic emission frequency.
[0054] According to embodiments of this disclosure, this disclosure also provides an electronic device that includes the ultrasonic radar speed measurement circuit described in this disclosure.
[0055] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this disclosure can be achieved, and this is not limited herein.
[0056] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.
[0057] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.
Claims
1. An ultrasonic radar speed measurement method, characterized in that, The method includes: The ultrasonic echo signal reflected by the target object is amplified with low noise. The amplified ultrasonic echo signal is processed by analog-to-digital conversion to obtain a digital echo signal; The digital echo signal is input to the frequency shift extraction unit, and the bandpass filter in the frequency shift extraction unit filters the digital echo signal; the frequency shift extraction unit includes multiple parallel bandpass filters, and the center frequency of each bandpass filter corresponds to a Doppler frequency shift; The target Doppler frequency shift corresponding to the digital echo signal is determined based on the output signal amplitude of the bandpass filter. The velocity of the target object is determined based on the target Doppler frequency shift.
2. The method according to claim 1, characterized in that, The filtering of the digital echo signal by the bandpass filter in the frequency shift extraction unit includes: If the target object is stationary, the digital echo signal passes through a bandpass filter in the frequency shift extraction unit where the Doppler frequency shift is zero; If the target object is running, the digital echo signal passes through a bandpass filter in the frequency shift extraction unit where the matching degree between the Doppler frequency shift and the frequency shift of the digital echo signal is greater than a first threshold.
3. The method of claim 1, wherein, Determining the target Doppler frequency shift corresponding to the digital echo signal based on the output signal amplitude of the bandpass filter includes: If the output signal amplitude of only one bandpass filter is greater than the second threshold, then the center frequency of the bandpass filter is determined as the target Doppler shift.
4. The method of claim 1, wherein, Determining the target Doppler frequency shift corresponding to the digital echo signal based on the output signal amplitude of the bandpass filter includes: In response to the existence of multiple adjacent bandpass filters whose output signal amplitudes are greater than the second threshold, the ratio of the output signal amplitudes of the multiple bandpass filters is determined. Based on the output signal amplitude ratio and the center frequencies of the plurality of bandpass filters, the target Doppler frequency shift corresponding to the digital echo signal is determined.
5. The method of claim 1, wherein, Determining the velocity of the target object based on the target Doppler frequency shift includes: The velocity of the target object is determined based on the target Doppler frequency shift, sound velocity, and ultrasonic emission frequency.
6. An ultrasonic radar speed measuring circuit, characterized by The circuit includes: The signal amplification unit is used to amplify the ultrasonic echo signal reflected by the target object with low noise. The analog-to-digital conversion unit is used to perform analog-to-digital conversion on the amplified ultrasonic echo signal to obtain a digital echo signal. The frequency shift extraction unit includes multiple parallel bandpass filters, each bandpass filter having a center frequency corresponding to a Doppler frequency shift, used to filter the digital echo signal based on the bandpass filters; A frequency shift detection unit is used to monitor the output signal amplitude of each bandpass filter and determine the target Doppler frequency shift corresponding to the digital echo signal based on the output signal amplitude of the bandpass filter. A velocity calculation unit is used to determine the velocity of the target object based on the target Doppler frequency shift.
7. The circuit of claim 6, wherein, The frequency shift extraction unit is further configured to: If the target object is stationary, the digital echo signal passes through a bandpass filter in the frequency shift extraction unit where the Doppler frequency shift is zero; If the target object is running, the digital echo signal passes through a bandpass filter in the frequency shift extraction unit where the matching degree between the Doppler frequency shift and the frequency shift of the digital echo signal is greater than a first threshold.
8. The circuit of claim 6, wherein, The frequency shift detection unit is also used for: If the output signal amplitude of only one bandpass filter is greater than the second threshold, then the center frequency of the bandpass filter is determined as the target Doppler shift.
9. The circuit of claim 6, wherein, The frequency shift detection unit is also used for: In response to the existence of multiple adjacent bandpass filters whose output signal amplitudes are greater than the second threshold, the ratio of the output signal amplitudes of the multiple bandpass filters is determined. Based on the output signal amplitude ratio and the center frequencies of the plurality of bandpass filters, the target Doppler frequency shift corresponding to the digital echo signal is determined.
10. An electronic device, comprising: The ultrasonic radar speed measurement circuit includes any one of claims 6-9.