Single-chip 360-degree spiral blade-based mechanical doppler signal generation device and velocity measurement method thereof

Abstract

This invention discloses a mechanical Doppler signal generating device and its velocity measurement method based on a single 360-degree helical blade. The device includes a single 360-degree helical blade, a support rod, a base, and an ultrasonic probe. The 360-degree single helical blade is mounted on the base via the support rod and is driven to rotate by a motor. An ultrasonic probe is positioned directly in front of the fan-shaped surface of the 360-degree helical blade for transmitting and receiving ultrasonic signals. This invention features a simple structure, small size, high speed, and facilitates the generation of adjustable, high-quality Doppler echo signals. It effectively reduces costs and is highly suitable for teaching and research, as well as for verifying ultrasonic Doppler velocimetry systems.

Description

Technical Field

[0001] This invention belongs to the field of ultrasonic applications. It utilizes the motion characteristics of a single helical blade to generate a stable mechanical Doppler signal, converting angular velocity into a linear velocity that is easy to measure, and is used to verify the accuracy of the ultrasonic Doppler measurement system. Background Technology

[0002] When a sound wave source moves, the measured frequency differs from the actual frequency emitted by the source. The magnitude of this frequency shift is determined by the direction and velocity of the source's motion; this phenomenon is called the Doppler effect. The Doppler effect can be used to measure the velocity of moving objects.

[0003] Existing devices for generating mechanical Doppler signals are complex in structure, mostly employing linear harmonic motion, resulting in large size and limitations in travel distance. They cannot maintain uniform motion for extended periods, leading to unstable Doppler signals that are inconvenient for ultrasonic Doppler measurement systems to acquire and measure.

[0004] Existing Doppler signal generating devices have limited range and speed, resulting in very limited frequency shift of the generated Doppler signals, which is insufficient for comprehensive testing of ultrasonic Doppler measurement systems.

[0005] 360-degree invention content

[0006] To overcome the shortcomings of the prior art, this invention provides a mechanical Doppler signal generating device and its velocity measurement method based on a single helical blade, aiming to generate a stable and controllable mechanical Doppler ultrasonic signal, thereby comprehensively verifying the accuracy of the ultrasonic Doppler velocimetry system.

[0007] The present invention solves the technical problem by adopting the following technical solution:

[0008] The mechanical Doppler signal generating device based on a single 360-degree helical blade of the present invention is characterized in that it includes: a single 360-degree helical blade, a support rod, a base, and an ultrasonic probe;

[0009] A single 360-degree spiral blade is mounted on the base via a support rod, and the single 360-degree spiral blade is driven to rotate by a motor.

[0010] An ultrasonic probe is positioned directly in front of the fan-shaped surface of the 360-degree single helical blade to transmit and receive ultrasonic signals.

[0011] The speed measurement method of the present invention based on the mechanical Doppler signal generation device of the single 360-degree helical blade is characterized by the following steps:

[0012] Step 1: Use a motor to control the rotation of a single 360-degree spiral fan blade. After the rotation speed of the single 360-degree spiral fan blade stabilizes, use an ultrasonic probe to emit an ultrasonic wave at a frequency of [frequency missing] towards the single 360-degree spiral fan blade. The ultrasonic signal;

[0013] Step 2: According to the Doppler effect, the frequency received by a single 360-degree spiral blade is... After receiving the ultrasonic signal, a frequency of is generated. The echo signal;

[0014] Step 3: According to the Doppler effect, the frequency received by the ultrasonic probe after reflection from a single 360-degree spiral fan blade is... The doopler echo signal;

[0015] Step 4: Analyze and process the doopler echo signal to obtain the rotational angular velocity of a single 360-degree spiral fan blade;

[0016] Step 4.1: Calculate the Doppler frequency shift using equation (1). :

[0017] (1)

[0018] Step 4.2: Construct the Doppler frequency shift using equation (2) linear velocity of a single 360-degree helical blade Relationship:

[0019] (2)

[0020] In equation (2), The speed at which ultrasound propagates;

[0021] Step 4.3: Calculate the number of rotations of a single 360-degree spiral blade using formula (3). horizontal displacement at time :

[0022] (3)

[0023] In equation (3), The pitch of a single 360-degree helical blade; The angle of rotation of a single 360-degree spiral blade;

[0024] Step 4.4: Construct the angular velocity of a single 360-degree helical blade using equation (4). With linear velocity Relationship: (4)

[0025] In equation (4), A single 360-degree spiral blade rotates Time taken;

[0026] Step 4.5: Use equation (5) to obtain the angular velocity of a single 360-degree helical blade. :

[0027] (5)

[0028] Step 5: After adjusting the single 360-degree spiral fan blade to different speeds using the motor, return to Step 1 and execute the sequence, thereby realizing the speed measurement of a single 360-degree spiral blade based on the Doppler effect.

[0029] Compared with existing technologies, the beneficial effects of this invention are reflected in:

[0030] 1. Because the structure of this invention is simpler than that of traditional devices for generating mechanical doopler ultrasonic signals, the cost is effectively reduced.

[0031] 2. The single 360-degree spiral blade of this invention can maintain a constant speed rotation over a long period of time with controllable rotation speed. By emitting ultrasonic waves through an ultrasonic probe, a stable and adjustable mechanical doopler ultrasonic signal can be generated without replacing the ultrasonic probe. Compared with traditional devices for generating mechanical doopler ultrasonic signals, this invention effectively improves the quality and spectral range of the generated mechanical doopler ultrasonic signal.

[0032] 3. Based on the structural characteristics and rotation features of a single 360-degree spiral blade, this invention can convert the angular velocity of rotation into a linear velocity that is easy to measure with an ultrasonic Doppler measurement system, thus facilitating the verification of the reliability of the ultrasonic Doppler measurement system. Attached Figure Description

[0033] Figure 1 This is a structural diagram of a single 360-degree helical blade of the present invention;

[0034] Figure 2 This is a structural diagram of the present invention in its static state;

[0035] Figure 3 This is a flowchart illustrating the measurement process of a single 360-degree spiral blade according to the present invention.

[0036] The following are the labels in the diagram: 1 Single 360-degree spiral blade; 2 Support rod; 3 Base; 4 Ultrasonic probe. Detailed Implementation

[0037] In this embodiment, as Figure 2As shown, the mechanical Doppler signal generating device based on a single 360-degree helical blade is a device that can maintain a constant speed for a long time and whose speed can be adjusted to generate mechanical Doppler signals. This device can convert angular velocity into linear velocity that is easy to measure by an ultrasonic Doppler velocimetry system, aiming to simplify existing measurement methods while improving measurement accuracy and speed. Specifically, the device mainly includes: a single 360-degree helical blade 1, a support rod 2, a base 3, and an ultrasonic probe 4.

[0038] A single 360-degree spiral blade 1 is mounted on the base 3 via a support rod 2, and the single 360-degree spiral blade 1 is driven to rotate by a motor.

[0039] An ultrasonic probe 4 is positioned directly in front of the fan-shaped surface of a single 360-degree helical blade 1, used for transmitting and receiving ultrasonic signals. The ultrasonic probe has two main operating modes: CW (continuous wave) mode and PW (pulse wave) mode, which can transmit continuous wave signals and pulse wave signals respectively.

[0040] In this embodiment, the speed measurement method of a mechanical Doppler signal generation device for a single 360-degree helical blade is performed according to the following steps:

[0041] Step 1: Use a motor to control the rotation of a single 360-degree spiral fan blade 1. After the rotation speed of the single 360-degree spiral fan blade 1 stabilizes, use an ultrasonic probe 4 to emit an ultrasonic wave at a frequency of [frequency missing] towards the single 360-degree spiral fan blade 1. The ultrasonic signal;

[0042] Step 2: According to the Doppler effect, the frequency received by a single 360-degree spiral blade 1 is... After receiving the ultrasonic signal, a frequency of is generated. Assuming the direction of motion is towards the ultrasonic probe 4, the frequency received by the single 360-degree spiral blade 1 can be obtained using equation (1). :

[0043] (1)

[0044] Equation (1) yields the result that... The speed at which ultrasound propagates. The relative velocity between the single 360-degree helical blade 1 and the ultrasonic probe 4. The wavelength of ultrasound;

[0045] Step 3: According to the Doppler effect, the frequency received by the ultrasonic probe 4 after reflection by the single 360-degree spiral fan blade 1 is... The doopler echo signal. At this time, the 360-degree single spiral fan blade 1 is equivalent to the wave source, and the ultrasonic probe 4 is equivalent to the receiver. The frequency of the doopler echo signal received by the ultrasonic probe 4 is obtained by using equation (2). :

[0046] (2)

[0047] Step 4: Use an ultrasonic Doppler velocimetry system to analyze and process the doopler echo signal to obtain the rotational angular velocity of a single 360-degree spiral fan blade 1.

[0048] Step 4.1, Doppler frequency shift The Doppler frequency shift value is the difference between the probe's receiving frequency and the probe's transmitting frequency, as shown in equation (3):

[0049] (3)

[0050] Step 4.2, due to the measured The value is often much smaller than The value, therefore, in the denominator The term can be omitted, hence the Doppler frequency shift. Measuring the linear velocity of a moving object The relationship is shown in equation (4):

[0051] (4)

[0052] Step 4.3, as follows Figure 1 As shown, based on the structural characteristics of a single 360-degree spiral blade 1, each rotation corresponds to a horizontal displacement. Therefore, each rotation horizontal displacement at time As shown in equation (5):

[0053] (5)

[0054] Step 4.4: The angular velocity of a single 360-degree helical blade 1 can be obtained. With the measured linear velocity The relationship is shown in equation (6): (6)

[0055] In equation (6), The pitch of a single 360-degree helical blade 1. For rotation Time taken;

[0056] Step 4.5: Use equation (7) to obtain the angular velocity of a single 360-degree helical blade 1. :

[0057] (7)

[0058] when When the value is positive, it indicates that the single 360-degree helical blade 1 rotates clockwise; when... When the value is negative, it indicates that the single 360-degree spiral blade 1 is rotating counterclockwise.

[0059] Step 5: After adjusting the single 360-degree spiral fan blade 1 to different speeds using the motor, return to step 1 and execute sequentially to achieve speed measurement of the single 360-degree spiral fan blade 1 based on the Doppler effect.

[0060] Angular velocity measured by an ultrasonic Doppler velocimetry system The reliability of the ultrasonic Doppler velocimetry system can be verified by comparing it with the set rotation speed.

Claims

1. A speed measurement method using a mechanical Doppler signal generating device for a single 360-degree helical blade, wherein the mechanical Doppler signal generating device comprises: A single 360-degree spiral blade (1), a support rod (2), a base (3), and an ultrasonic probe (4); A single 360-degree spiral blade (1) is mounted on the base (3) via a support rod (2), and the single 360-degree spiral blade (1) is driven to rotate by a motor; an ultrasonic probe (4) is mounted directly in front of the fan-shaped surface of the 360-degree single spiral blade (1) for transmitting and receiving ultrasonic signals, characterized in that the speed measurement method is performed according to the following steps: Step 1: Use a motor to control the rotation of a single 360-degree spiral fan blade (1), and after the rotation speed of the single 360-degree spiral fan blade (1) stabilizes, use an ultrasonic probe (4) to emit an ultrasonic wave at a frequency of [frequency missing] towards the single 360-degree spiral fan blade (1). The ultrasonic signal; Step 2: According to the Doppler effect, a single 360-degree spiral blade (1) receives a frequency of... After receiving the ultrasonic signal, a frequency of is generated. The echo signal; Step 3: According to the Doppler effect, the frequency received by the ultrasonic probe (4) from the reflection of the single 360-degree spiral fan blade (1) is... The doopler echo signal; Step 4: Analyze and process the doopler echo signal to obtain the rotational angular velocity of a single 360-degree spiral fan blade (1); Step 4.1: Calculate the Doppler frequency shift using equation (1). : (1) Step 4.2: Construct the Doppler frequency shift using equation (2) The linear velocity of a single 360-degree helical blade (1) Relationship: (2) In equation (2), The speed at which ultrasound propagates; Step 4.3: Calculate the number of rotations per 360-degree spiral blade (1) using formula (3). horizontal displacement at time : (3) In equation (3), The pitch of a single 360-degree helical blade (1); The angle of rotation of a single 360-degree spiral blade (1); Step 4.4: Construct the angular velocity of a single 360-degree helical blade (1) using equation (4). With linear velocity Relationship: (4) In equation (4), For a single 360-degree helical blade (1) to rotate Time taken; Step 4.5: Use equation (5) to obtain the angular velocity of a single 360-degree helical blade (1). : (5) Step 5: After adjusting the single 360-degree spiral fan blade (1) to different speeds using the motor, return to step 1 and execute sequentially to realize the speed measurement of the single 360-degree spiral fan blade (1) based on the Doppler effect.

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