The subject matter herein generally relates to ultrasonic ranging technique, and particularly relates to an ultrasonic ranging device, an ultrasonic ranging method, and a controller.
A conventional ultrasonic ranging device includes a single ultrasonic probe for transmitting an ultrasonic wave. The ultrasonic ranging device is configured to calculate a distance to a target object according to the round-trip time with a known sound velocity. In single ultrasonic probe, the probe curvature has determined the focal point position and limited its application field, which makes it difficult to obtain target distances over a large field. The ultrasonic wave reflected by the target object may diverge if the target object is too far from the focal point, which reduces a resolution of the ultrasonic ranging device.
Therefore, there is room for improvement in the art.
Implementations of the present disclosure will now be described, by way of embodiment, with reference to the attached figures.
It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein may be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features of the present disclosure.
The term “coupled” is defined as connected, whether directly or indirectly through intervening components and is not necessarily limited to physical connections. The connection can be such that the objects are permanently connected or releasably connected. The term “comprising” when utilized, means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in the so-described combination, group, series, and the like.
Referring to
The ultrasonic ranging device 10 can be assembled in intelligent devices as a functional module for ranging. For example, the ultrasonic ranging device 10 may be assembled in a vehicle or a carrier to construct a map, reveal obstacles in a driving path when driving, and obtain distances to the obstacles.
Referring to
The ultrasonic transmitter 11 includes a plurality of transmitting channels 111 (shown in
The first ultrasonic wave is reflected by the target object 20 when it reaches the target object 20. In the present embodiment, the reflection of the first ultrasonic wave by the target object 20 is defined as a second ultrasonic wave. Each of the transmitting channels 111 in the ultrasonic transmitter 11 can receive the second ultrasonic wave.
A ranging period is defined as the period of time between one transmission of the first ultrasonic wave and the reception of the corresponding second ultrasonic wave. The ultrasonic ranging device 10 may work during numerous ranging periods. In each of the ranging periods, a number of the transmitting channels 111 which transmit the first ultrasonic waves can be controlled according to actual needs. In general, the larger the range, the greater the number, and the smaller the range, the less can be the number. In addition, the ultrasonic focal point can be controlled by adjusting the time-delay at each channel according to the application needs.
The ultrasonic transmitting/receiving circuit 12 includes an ultrasonic transmitting circuit 121, an ultrasonic receiving circuit 122, and a transmitting/receiving switching circuit 123 electrically connected to the ultrasonic transmitting circuit121 and the ultrasonic receiving circuit122. The ultrasonic transmitting circuit 121 includes a transmitting beamformer, an amplifier, and a digital-analog converter electrically connected to the transmitting beamformer and the amplifier. The ultrasonic receiving circuit122 includes a receiving beamformer, an amplifier, and an analog-digital converter electrically connected to the receiving beamformer and the amplifier. The amplifiers in the ultrasonic transmitting circuit 121 and the ultrasonic receiving circuit 122 are electrically connected to the transmitting/receiving switching circuit 123. The controller 13 includes a transmission control circuit 131 and a data processing circuit 132 electrically connected to each other. The transmission control circuit 131 is electrically connected to the ultrasonic transmitting circuit121, and the data processing circuit 132 is electrically connected to the ultrasonic receiving circuit 122.
The transmission control circuit 131 is configured to output a command to control the ultrasonic transmitting circuit 121 to activate at least one or more transmitting channel 111 to generate an ultrasonic transmission signal. The transmitting/receiving switching circuit 123 is configured to switch to a transmitting state to transmit the ultrasonic transmission signal to at least one transmitting channel 111 to transmit the first ultrasonic wave. The second ultrasonic wave reflected by the target object 20 is received by the at least one transmitting channel 111. The transmitting/receiving switching circuit 123 is configured to switch to a receiving state, so that the second ultrasonic wave when received is converted into a signal by the ultrasonic receiving circuit 122, wherein the signal is recognizable to the data processing circuit 132. The data processing circuit 132 can control to activate at least one or more transmitting channel 111 to receive second ultrasonic wave and calculate the distance of the target object 20 from the ultrasonic ranging device 10 according to a transmitting time of the first ultrasonic wave and a receiving time of the second ultrasonic wave, similar to a time-of-flight calculation.
The embodiment of the present disclosure further provides an ultrasonic ranging method applied to the ultrasonic ranging device 10 (or applied to the controller 13).
Referring to
At block S1, controlling at least one of the plurality of transmitting channels 111 to transmit a first ultrasonic wave, the first ultrasonic wave being reflected by a target object 20 when reaches the target object 20. The reflection of the first ultrasonic wave by the target object 20 is defined as a second ultrasonic wave.
At block S2, controlling the ultrasonic transmitter 11 to receive the second ultrasonic wave and obtaining a distance of the target object 20 according to a transmitting time of the first ultrasonic wave and a receiving time of the second ultrasonic wave.
At block S1, the first ultrasonic wave transmitted by the ultrasonic transmitter 11 can be focused or can be divergent.
Referring to
The transmitting beamformer in transmitting circuit 121 is configured to obtain transmitting-delay times of the transmitting channels 111 to transmit the first ultrasonic waves according to distances between the focal point and each of the transmitting channels. The controller 13 is further configured to control the transmitting channels 111 to transmit the first ultrasonic waves in turn according to the transmitting-delay time.
Referring to
The distances of the detection point 21 to the transmitting channels E1, E2, E3, E4, and E5 are defined as Tx_path1, Tx_path2, Tx_path3, Tx_path4, and Tx_path5. The transmitting-delay times of the transmitting channels E1, E2, E3, E4, and E5 are defined as τTx1, τTx2, τTx3, τTx4, and τTx5. As can be seen from
Referring to
The transmitting delay times are calculated by the following formula (1):
Referring to
A plane cartesian coordinate system including a Z-axis and an X-axis is established. The Z-axis of the plane cartesian coordinate system is a straight line passing through the virtual focal point F2, and the X-axis of the plane cartesian coordinate system is a straight line perpendicular to the Z-axis, tangential to the ring formed by the transmitting channels 111 and close to the transmitting channels 111 transmitting the first ultrasonic waves. A coordinate of an intersection of the X-axis and Z-axis is defined as (0,0), a coordinate of the virtual focal point F2 is defined as (0, −R), coordinates of the transmitting channels 111 transmitting the first ultrasonic waves are defined as (Xn, Zn), 1≤n≤5, N being an integer.
In the modified embodiment, the transmitting-delay times are calculated by the following formula (2):
The target object 20 reflects the first ultrasonic waves received, as the second ultrasonic waves received by the transmitting channels 111 transmitting the first ultrasonic waves.
At block S2, the second ultrasonic waves received are dynamically focused. On transmit beamforming, the fist ultrasonic wave is fired only once to the specified position, as for the receiving beamforming, the second ultrasonic waves are continuously stored on each channels and can be dynamically updated. The receiving beamformer in receiving circuit 122 is configured to obtain receiving-delay times of the transmitting channels 111 receiving the second ultrasonic waves according to the distance between the locations in imaging area and each of channels. The controller 13 is further configured to control the transmitting channels 111 to receive the second ultrasonic waves in turn according to the receiving-delay times.
Referring to
Although the transmitting channels E1, E2, E3, E4, and E5 have different arrival time before receiving the second ultrasonic waves, the controller 13 can be controlled to receive the second ultrasonic waves simultaneously by adjusting values of the receiving-delay times τRx1, τRx2, τRx3, τRx4, and τRx5. After the receive delay time of channel data are properly adjusted, all of signals are summed. This is so called as delay-and-sum beamformer. This process will be repeated until all of detection points in imaging area are completed.
Referring to
At block S1, if all of the transmitting channels 111 are controlled to transmit the first ultrasonic waves in a divergent manner during the ranging period, the possible range of the ultrasonic ranging device 10 can be 360° , which is conducive to improve a ranging speed, however a spatial resolution needs to be improved. In block S1, if the transmitting channels 111 are controlled to transmit the first ultrasonic waves focused during the ranging period, the target object 20 far away from the ultrasonic ranging device 10 can be measured, and the spatial resolution is significantly improved, however the detection area is reduced.
In the present embodiment, the target object 20 defines a plurality of detection points. The ultrasonic ranging device 10 repeats block S1 and block S2 until completing the ranging of all of the detection points.
In the present embodiment, the distance to the target object 20 is obtained through a plurality of the ranging periods. The transmitting channels 111 are controlled to transmit different forms (divergent or focused) of first ultrasonic waves during different ranging periods, and the distance of the target object 20 is obtained by compounding ranging information in each of the ranging periods, which is conducive to enabling the ultrasonic ranging device 10 to achieve beneficial effects of both the first ultrasonic waves being divergent and being focused.
Referring to
Referring to
In another embodiment, accuracy of the distance d of the target object 20 can be further improved by increasing a ranging period for transmitting the first ultrasonic waves which are focused (the third ranging period).
In other embodiments, more ranging periods can be added to transmit the first ultrasonic waves which are focused to obtain more ranging information, and more ranging information can be averaged to obtain the distance d of the target object 20.
The ultrasonic ranging device 10, the ultrasonic ranging method, and the controller 13 in the present embodiment can obtain ranging information (or positional information) of the target object 20 in a complete range (360°) in one ranging period by setting the ultrasonic transmitter 11 including the plurality of transmitting channels 111 arranged in a ring, which is conducive to improving the ranging speed of the ultrasonic ranging device 10. Further, the number of the transmitting channels 111 transmitting the first ultrasonic waves is adjustable (can be one or more), so that a detectable range is adjustable, a detection mode of the ultrasonic ranging device 10 can match actual detection needs, and the detection mode is more flexible.
The first ultrasonic waves which are focused can be obtained according to the transmitting-delay times, which focuses the first ultrasonic waves transmitted during a same ranging period onto the target object 20 simultaneously, so that an energy density of the first ultrasonic waves is enhanced and the spatial resolution is improved. Moreover, the first ultrasonic waves which are focused can be projected to a further distance, which is conducive to detecting a further target object 20.
The second ultrasonic waves which are focused can be obtained according to the receiving-delay times, which focuses the second ultrasonic waves received in the same ranging period onto the transmitting channels 111 simultaneously, so that an energy density of the second ultrasonic waves is enhanced, the spatial resolution is improved, and the distance calculated by the controller 13 is more accurate.
The first ultrasonic waves transmitted divergently can also be obtained according to the transmitting-delay time. The divergent first ultrasonic waves can significantly expand the range of the ultrasonic ranging device 10 during one ranging period. Therefore, in a case that a specific range is needed to be detected, it is conducive to reduce a number of ranging periods by expanding the range of the ultrasonic ranging device 10 during one ranging period. That is, it is conducive to improving the ranging speed.
Different ranging information can be obtained in different ranging periods by controlling the ultrasonic ranging device 10 to transmit different forms of the first ultrasonic waves (focused or divergent) in the different ranging periods. The different ranging information obtained in the different ranging periods is used to obtain the distance of the target object 20, which is conducive to achieve the beneficial effects of the first ultrasonic waves being focused and the first ultrasonic waves being divergent at the same time. That is, it is conducive for the ultrasonic ranging device 10 to achieve a high resolution, an accurate distance, and a high ranging speed.
It is to be understood, even though information and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the present embodiments, the disclosure is illustrative only. Changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the present embodiments to the full extent indicated by the plain meaning of the terms in which the appended claims are expressed.
Number | Date | Country | Kind |
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202011356761.2 | Nov 2020 | CN | national |