CN218974595U

CN218974595U - Ultrasonic sensor chip and ultrasonic radar device

Info

Publication number: CN218974595U
Application number: CN202223469969.2U
Authority: CN
Inventors: 眭志凌; 李桂萍; 王炯
Original assignee: Shanghai Jihaiyingxin Technology Co ltd; Chengdu Jihai Technology Co ltd; Zhuhai Geehy Semiconductor Co Ltd
Current assignee: Chengdu Jihai Technology Co ltd; Shanghai Lingfan Microelectronics Co ltd; Zhuhai Geehy Semiconductor Co Ltd
Priority date: 2022-12-23
Filing date: 2022-12-23
Publication date: 2023-05-05
Anticipated expiration: 2032-12-23

Abstract

The embodiment of the application provides an ultrasonic sensor chip and an ultrasonic radar device, relates to the technical field of ultrasonic waves, and can reduce interference of environment on ultrasonic signal processing. An ultrasonic sensor chip comprising: the device comprises a driving circuit, a signal processing circuit and a storage module, wherein the driving circuit comprises a carrier wave generating module, a modulation code generating module and a phase modulation module, and the signal processing circuit comprises a sampling module, a correlation calculating module and a processing module; the output ends of the carrier wave generating module and the modulation code generating module are electrically connected with the input end of the phase modulation module; the output end of the sampling module is electrically connected with the input end of the correlation calculation module; the input end of the storage module is electrically connected with the output end of the driving circuit, the output end of the storage module is electrically connected with the input end of the correlation calculation module, and the reference signal is stored in the storage module; the input end of the processing module is electrically connected with the output end of the correlation calculation module.

Description

Ultrasonic sensor chip and ultrasonic radar device

Technical Field

The present application relates to the field of ultrasonic technology, and in particular, to an ultrasonic sensor chip and an ultrasonic radar apparatus.

Background

At present, an ultrasonic radar apparatus may be applied to a vehicle, for example, for determining a distance between the vehicle and an obstacle. An ultrasonic radar device transmits an ultrasonic signal on the one hand and receives an ultrasonic signal on the other hand, wherein the received signal is divided into time segments, which are substantially equal to half the burst length. At each time segment of the ultrasonic wave reception signal, a peak value is determined, and a distance between the vehicle and the obstacle is determined from the peak value signal. However, clutter, noise, other ultrasound waves, etc. in the environment may interfere with the ultrasound system, making the existing solutions less effective in assessing obstacle distance.

Disclosure of Invention

An ultrasonic sensor chip and an ultrasonic radar apparatus capable of reducing interference of an environment to ultrasonic signal processing.

In a first aspect, there is provided an ultrasonic sensor chip comprising: the device comprises a driving circuit, a signal processing circuit and a storage module, wherein the driving circuit comprises a carrier wave generating module, a modulation code generating module and a phase modulation module, and the signal processing circuit comprises a sampling module, a correlation calculating module and a processing module;

the input ends of the carrier generating module and the modulation code generating module are used for being coupled to the micro-processing chip to receive the trigger signal, and the output ends of the carrier generating module and the modulation code generating module are electrically connected with the input end of the phase modulation module; the output end of the phase modulation module is used for being coupled to the first ultrasonic transducer; the input end of the sampling module is coupled to the second ultrasonic transducer, and the output end of the sampling module is electrically connected with the input end of the correlation calculation module; the input end of the storage module is electrically connected with the output end of the driving circuit, the output end of the storage module is electrically connected with the input end of the correlation calculation module, and the reference signal is stored in the storage module; the input end of the processing module is electrically connected with the output end of the correlation calculation module, and the output end of the processing module is used for being coupled to the micro-processing chip to send a feedback signal; wherein,,

The carrier generating module receives the trigger signal to generate a carrier and inputs the carrier to the phase modulating module;

the modulation code generation module receives the trigger signal to generate a modulation code, and inputs the modulation code to the phase modulation module;

the phase modulation module is used for receiving the modulation code and the carrier signal, carrying out phase modulation on the carrier to obtain a modulation wave, and outputting the modulation wave to the first ultrasonic transducer;

the sampling module is used for sampling the ultrasonic signals received by the second ultrasonic transducer and inputting the sampled signals to the correlation calculation module;

the correlation calculation module reads the reference signals in the storage module to determine the correlation of the sampling signals, inputs the correlation information into the processing module, and correlates the correlation with the modulation code and the carrier;

and the processing module is used for receiving the correlation information and outputting a feedback signal with the correlation reaching a preset value.

In a second aspect, there is provided an ultrasonic radar apparatus comprising: the ultrasonic sensor chip described above;

the input end of the first ultrasonic transducer is electrically connected with the output end of the ultrasonic sensor chip and is used for receiving the modulated wave and transmitting ultrasonic signals;

And the output end of the second ultrasonic transducer is electrically connected with the input end of the ultrasonic sensor chip, and the ultrasonic sensor chip is used for sampling ultrasonic signals received by the second ultrasonic transducer.

According to the ultrasonic sensor chip and the ultrasonic radar device, the carrier wave is modulated through the modulation code, the modulation wave for exciting ultrasonic wave transmission is generated, the correlation degree of the received signal is calculated through the correlation degree calculation module, whether the received signal is a designated echo is determined according to the calculation result, so that adverse effects of interference, noise and the like in the environment on ultrasonic signal processing are reduced, and the accuracy of ultrasonic signal processing is improved. For example, when the ultrasonic sensor is applied to an ultrasonic radar apparatus of a vehicle, accuracy of radar positioning can be improved.

Drawings

Fig. 1 is a schematic structural diagram of an ultrasonic radar apparatus and an obstacle according to an embodiment of the present application;

FIG. 2 is a schematic waveform diagram of a phase modulation process according to an embodiment of the present application;

FIG. 3 is a schematic diagram of phase modulation in an embodiment of the present application;

fig. 4 is a schematic diagram of spectral variation before and after phase modulation of a carrier according to an embodiment of the present application;

FIG. 5 is a schematic view of a part of the structure of the ultrasonic radar apparatus of FIG. 1;

fig. 6 is a schematic diagram of spectral variation before and after modulation despreading of a signal received by a second ultrasonic transducer and including only a modulation wave in an embodiment of the present application;

fig. 7 is a schematic diagram of spectral variation before and after modulation despreading of a signal including a modulated wave and interference received by a second ultrasonic transducer in an embodiment of the present application;

FIG. 8 is a schematic view of a portion of the structure of the ultrasonic radar apparatus of FIG. 1;

fig. 9 is a schematic diagram of correlation between a carrier and a sampling signal received at different times in the embodiment of the present application;

FIG. 10 is a schematic diagram of waveform sampling according to an embodiment of the present application;

FIG. 11 is a schematic view of a part of the structure of the ultrasonic radar apparatus of FIG. 1;

FIG. 12 is a schematic view of a part of the structure of the ultrasonic radar apparatus of FIG. 1;

FIG. 13 is a schematic diagram of sampling waveforms with different amplitudes according to an embodiment of the present application;

FIG. 14a is a schematic view of a portion of the structure of the ultrasonic radar apparatus of FIG. 1;

FIG. 14b is a schematic view of a portion of the structure of the ultrasonic radar apparatus of FIG. 1;

FIG. 15 is a schematic view of a part of the structure of the ultrasonic radar apparatus of FIG. 1;

FIG. 16 is a schematic diagram illustrating a relationship between correlation and modulation code according to an embodiment of the present application;

fig. 17 is a schematic flow chart of a signal processing method in an embodiment of the present application;

FIG. 18 is a flowchart of another signal processing method according to an embodiment of the present disclosure;

fig. 19 is a flowchart of another signal processing method according to an embodiment of the present application;

FIG. 20 is a flowchart of another signal processing method according to an embodiment of the present disclosure;

FIG. 21 is a flowchart of another signal processing method according to an embodiment of the present disclosure;

fig. 22 is a flowchart of another signal processing method in the embodiment of the application.

Detailed Description

The terminology used in the description section of the present application is for the purpose of describing particular embodiments of the present application only and is not intended to be limiting of the present application.

The embodiment of the application provides an ultrasonic sensor chip and an ultrasonic radar device, the ultrasonic sensor chip can be applied to the ultrasonic radar device, as shown in fig. 1, the ultrasonic radar device 100 comprises the ultrasonic sensor chip 10 and an ultrasonic transducer 200, the ultrasonic transducer 200 comprises a first ultrasonic transducer 201 and a second ultrasonic transducer 202, and an input end of the first ultrasonic transducer 201 is electrically connected to an output end of the ultrasonic sensor chip 10 and is used for receiving a modulation wave and transmitting an ultrasonic signal; the output end of the second ultrasonic transducer 202 is electrically connected to the input end of the ultrasonic sensor chip 10, and the ultrasonic sensor chip 10 is used for sampling the ultrasonic signal received by the second ultrasonic transducer 202. The first ultrasonic transducer 201 and the second ultrasonic transducer 202 may be two independent devices or may be integrated devices; the ultrasonic sensor chip 10 includes: the device comprises a driving circuit, a signal processing circuit and a storage module 81, wherein the driving circuit comprises a carrier generating module 1, a modulation code generating module 2 and a phase modulation module 3, and the signal processing circuit comprises a sampling module 4, a correlation calculating module 5 and a processing module 6. The input ends of the carrier generating module 1 and the modulation code generating module 2 are used for being coupled to the micro-processing chip 20 to receive the trigger signal, and the output ends of the carrier generating module 1 and the modulation code generating module 2 are electrically connected with the input end of the phase modulating module 3; the output of the phase modulation module 3 is for coupling to a first ultrasound transducer 201; the input end of the sampling module 4 is coupled to the second ultrasonic transducer 202, and the output end of the sampling module 4 is electrically connected with the input end of the correlation calculation module 5; the input end of the storage module 81 is electrically connected with the output end of the driving circuit, the output end of the storage module 81 is electrically connected with the input end of the correlation calculation module 5, and the storage module 81 stores reference signals; the input end of the processing module 6 is electrically connected with the output end of the correlation calculation module 5, and the output end of the processing module 6 is used for being coupled to the micro-processing chip 20 to send a feedback signal; the carrier generating module 1 receives a trigger signal to generate a carrier, and inputs the carrier to the phase modulating module 3; the modulation code generation module 2 receives the trigger signal to generate a modulation code, and inputs the modulation code to the phase modulation module 3; the phase modulation module 3 receives the modulation code and the carrier signal, performs phase modulation on the carrier to obtain a modulation wave, and outputs the modulation wave to the first ultrasonic transducer 201; the sampling module 4 is configured to sample the ultrasonic signal received by the second ultrasonic transducer 202, and input the sampled signal to the correlation calculation module 5; the correlation calculation module 5 reads the reference signal in the storage module 81 to determine the correlation of the sampling signal, and inputs the correlation information to the processing module 6, wherein the correlation is related to the modulation code, and the correlation is related to the carrier; and the processing module 6 is used for receiving the correlation information and outputting a feedback signal with the correlation reaching a preset value. The ultrasonic radar apparatus 100 may further include a micro-processing chip 20, an output terminal of the micro-processing chip 20 being electrically connected to an input terminal of the ultrasonic sensor chip 10, an input terminal of the micro-processing chip 20 being electrically connected to an output terminal of the ultrasonic sensor chip 10; the ultrasonic sensor chip 10 receives the trigger signal of the micro-processing chip 20 to generate a modulated wave, and the ultrasonic sensor chip 10 is also configured to transmit a feedback signal to the micro-processing chip 20 that receives a specified echo.

Specifically, at least one pin of the ultrasonic sensor chip 10 is electrically connected to the ultrasonic transducer 200, and at least one pin of the ultrasonic sensor chip 10 is electrically connected to the micro-processing chip 20 through a controller area network (Controller Area Network, CAN), an area interconnection network (Local Interconnect Network, LIN), point-to-Point (pt-to-pt), or the like. When the ultrasonic detection is required, the micro-processing chip 20 outputs a trigger signal to the ultrasonic sensor chip 10, and the ultrasonic sensor chip 10 drives the carrier generation module 1 to generate a carrier (for example, a sine wave) in response to the trigger signal from the micro-processing chip 20, and the modulation code generation module 2 generates a modulation code as a modulation signal. The phase modulation module 3 modulates the phase of the carrier wave according to the modulation code to obtain a modulation wave, namely, the phase of the carrier wave is regulated according to the modulation code, the regulated signal is the modulation wave, and the modulation wave is the ultrasonic excitation signal. The phase modulation module 3 outputs the modulated wave to the first ultrasonic transducer 201, and the first ultrasonic transducer 201 vibrates under the excitation control of the modulated wave to generate corresponding ultrasonic waves, and the ultrasonic waves are reflected when encountering an obstacle. The second ultrasonic transducer 202 receives the ultrasonic signal, and the sampling module 4 samples the ultrasonic signal received by the second ultrasonic transducer 202 to obtain a sampled signal, for example, the sampling module 4 is an Analog-to-Digital Converter (ADC) to convert the Analog signal into a digital signal. Because of interference, noise, and possibly other ultrasound waves generated by other ultrasound transducers in the environment, the waves received by the second ultrasound transducer 202 are not necessarily the ultrasound waves transmitted by the first ultrasound transducer 201. In the embodiment of the present application, the ultrasonic wave emitted by the first ultrasonic transducer 201 is generated based on the driving of the modulated wave modulated by the modulation code, and the ultrasonic wave has not only the signal characteristic of the carrier wave itself but also the signal characteristic of the modulation code. Therefore, for the ultrasonic signal received by the second ultrasonic transducer 202, after being sampled into a sampling signal, the correlation is determined according to the reference signal and the sampling signal in the correlation calculation module 5, if the correlation is judged to reach the preset value in the processing module 6, the signal is indicated to have the characteristics of both carrier and modulation code, namely, the signal is indicated to be from the first ultrasonic transducer 201 and is not an interference and noise signal, and therefore the signal is taken as a designated echo, namely, the designated echo is the echo signal of the ultrasonic wave transmitted by the first ultrasonic transducer 201, so that the distance between the ultrasonic signal and the obstacle is determined according to the designated echo. If the correlation degree is judged to not reach the preset value in the processing module 6, the signal is an interference and noise signal, so that the signal is not used as a designated echo, interference and noise are reduced in the subsequent process of determining the distance between the signal and the obstacle, and the accuracy of ultrasonic positioning is improved.

The microprocessor chip is generally called an electronic control unit (Electronic Control Unit, ECU) or a domain controller in an automobile, and may be, for example, a microprocessor (Microcontroller Unit, MCU), a Digital signal processing (Digital SignalProcessing, DSP), a microprocessor (Microprocessor Unit, MPU), a micro central processing unit (centralprocessing unit, CPU), or the like, a micro central control chip or a system-on-chip capable of processing Digital signals, analog signals, or performing functions such as signal control functions, instruction processing, and arithmetic operations.

According to the ultrasonic sensor chip, the carrier wave is modulated through the modulation code, the modulation wave for exciting ultrasonic wave transmission is generated, the correlation degree of the received signals is calculated through the correlation degree calculation module, whether the received signals are designated echoes or not is determined according to the calculation result, so that adverse effects of interference, noise and the like in the environment on ultrasonic signal processing are reduced, and the accuracy of ultrasonic signal processing is improved. For example, when the ultrasonic sensor chip is applied to an ultrasonic radar apparatus of a vehicle, accuracy of radar positioning can be improved.

In a possible embodiment, the ultrasonic sensor chip 10 further includes a first timer, which may be electrically connected to the processing module 6, and is used to start timing when the first ultrasonic transducer 201 transmits an ultrasonic signal, or to start timing when a trigger signal transmitted by the micro-processing chip 20 is received, and to stop timing when it is determined that a specified echo is received; the ultrasonic sensor chip 10 is also configured to calculate an obstacle distance from the time duration of the first timer and the specified echo, and transmit the obstacle distance to the micro-processing chip 20. The processing module 6 in the ultrasonic sensor chip 10 can calculate the distance of the obstacle according to the relation between time and the ultrasonic transmission speed; the distance information acquiring post-processing module 6 outputs data to the micro-processing chip 20, and the micro-processing chip 20 is used for making judgment according to the received data and triggering prompt, for example triggering a buzzer to send prompt sound, lamplight prompt, display screen prompt, voice prompt and the like.

In one possible embodiment, the micro-processing chip 20 may include a first timer, and the micro-processing chip 20 obtains a timing duration of the first timer and the received feedback signal obtains the obstacle distance. That is, the first timer may be also provided in the micro-processing chip 20, and the timer starts to count after the micro-processing chip 20 sends out a trigger signal for triggering the ultrasonic sensor chip 10 to generate a modulated wave, so that the first ultrasonic transducer 201 transmits an ultrasonic signal, stops counting when it is determined that a specified echo is received, and can calculate the distance of an obstacle according to the relationship between time and the ultrasonic transmission speed; and (3) after the distance information is obtained, corresponding actions are performed, such as triggering a buzzer to give out a prompt tone or triggering an alarm lamp and the like.

That is, in the ultrasonic radar apparatus, the obstacle distance may be calculated by any one of the ultrasonic sensor chip 10 and the micro-processing chip 20. For example, after determining the specified echo, the ultrasonic sensor chip 10 sends a feedback signal for receiving the specified echo, such as that the I/O pin clock is high or low, to the micro-processing chip 20, when determining the specified echo, the ultrasonic sensor chip 10 pulls the I/O pin high or low, the micro-processing chip 20 calculates the time from sending the trigger signal to receiving the indication signal according to the signal, calculates the distance of the obstacle, and then controls the corresponding prompting system to act; if the ultrasonic sensor chip 10 performs distance calculation, the data indicating different distances can be sent out through the I/O pins after the calculation is completed, the data is received and analyzed by the micro-processing chip 20, and the corresponding prompt system is controlled to perform actions according to the analysis result.

In one possible embodiment, the ultrasonic radar apparatus includes a plurality of ultrasonic sensor chips 10, a plurality of first ultrasonic transducers 201, and a plurality of second ultrasonic transducers 202.

In one possible implementation, as shown in fig. 2 and 3, the modulation code includes a first code value, for example, a first code value of 0, and a second code value of 1, where the first code value is used to flip the carrier phase by 180 ° and the second code value is used to keep the carrier phase unchanged during the modulation. If the signal circulated in the circuit is used for illustration, the signal input to the phase modulation module 3 by the modulation code generation circuit 1 comprises a first signal and a second signal, the phase modulation module 3 receives the carrier information corresponding to the output of the first signal, and the phase modulation module 3 receives the information of the output of the second signal which is 180 degrees different from the corresponding carrier.

Specifically, the modulation code includes a plurality of modulation chips, each having a width d, and one carrier period corresponds to one modulation chip width. For example, in fig. 2 the carrier wave is wave a having 9 sine wave periods; the modulation code is 111001100, wave B with 9 modulation chips. In the process of modulating a carrier wave according to a modulation code to obtain a modulation wave, when a wave A encounters a modulation code chip of 0, the phase of the sine wave is turned over by 180 degrees, when the wave A encounters a modulation code chip of 1, the phase of the sine wave is unchanged, and the modulation wave obtained after modulation is a wave C. That is, wave c=wave a=wave B, that is, wave a (111111111) ×wave B (111001100) =wave C (111001100), where "×" means that the above expression is that the carrier wave remains unchanged when encountering a modulation chip of 1, and the phase is inverted when encountering a modulation chip of 0, assuming that the sequence code is 1 when the initial phase of wave a, the sequence code after phase inversion is 0, that is, the sequence code of wave C after modulation by the modulation code is 111001100. After the phase modulation, the carrier wave after the phase modulation has a spread spectrum effect although the driving frequency of the carrier wave is not changed. As shown in fig. 4, before the phase modulation, the carrier has only one frequency, and a plurality of frequencies are generated after the modulation, which is equivalent to the frequency being dispersed, and it should be understood that the present solution does not adjust the frequency of the carrier, but adjusts the phase of the carrier, but generates a frequency modulation effect, which is a significant improvement over frequency modulation, as described in detail below.

In addition, the width of the chip does not necessarily correspond to one carrier period, but may also correspond to a plurality of carrier periods, and the principle is the same as that the width of one chip is equal to one carrier period, and the description is omitted here. Other descriptions of chip widths are described below.

In one possible embodiment, as shown in fig. 5, the ultrasonic sensor chip 10 further includes: the modulation and despreading module 8 is arranged between the sampling module 4 and the correlation calculation module 5, the input end of the modulation and despreading module 8 is coupled to the output end of the sampling module 4, and the output end of the modulation and despreading module 8 is coupled to the input end of the correlation calculation module 5; the storage module also stores a modulation code, and the input end of the modulation despreading module 8 is also electrically connected with the output end of the storage module 81 to read the modulation code; the reference signal is a carrier or a carrier orthogonal wave orthogonal to the carrier.

Specifically, the modulated wave obtained by sampling the ultrasonic signal received by the second ultrasonic transducer 202 by the sampling module 4 is a wave D, and the modulated despreading module 8 performs modulated despreading on the wave D according to the wave B, so that the obtained despread sampled signal is a wave E. The modulation despreading process is the same as the modulation process, i.e. wave e=wave d×wave B. As shown in fig. 6, if the signal received by the second ultrasonic transducer 202 only includes a modulated wave, the wave D corresponds to the wave C, the wave e=the wave c=the wave B, and the wave C has the sequence code 111001100, and the wave B is 111001100, and the wave e=the wave c=the wave b=111111111. The formula of the correlation calculation is the correlation value f= Σmn=m1×n1+m2×n2+ … +mn×nn (convolution operation), m= (M1, M2, …, mn), n= (N1, N2, …, nn). The correlation f= Σwave E is the wave a between the corresponding time sequences of the despread sampling signal (wave E) and the carrier wave (wave a), and since the wave E is equal to the wave a, the correlation value is high (e.g., 9 in the example) when two identical waves do correlation operation.

As shown in fig. 7, if the signal received by the second ultrasonic transducer 202 includes a specified echo (i.e., a spread modulated wave), an interference signal in the environment, a channel noise, a spread signal emitted by another device, or the like, the interference signal in the environment, the channel noise, or the spread signal emitted by another device are called unspecified echoes, and there are two cases where the unspecified echo is a spread signal, that is, a signal including multiple frequencies, and the other is a signal having a certain frequency that is particularly high, that is, a single frequency signal. Here, the received interference signal is a single frequency, and the other signals are spread spectrum signals.

For a better understanding, the examples herein are:

for example, the single-frequency sequence of the interference signal is denoted as a wave D1, where d1= 111111111111111111 (which is a frequency multiplication of 2 times the carrier), and the modulated and despread signal of the interference signal is a wave E1, where the wave E1=d1 is a wave B, and the correlation between the wave E1 and the wave a is calculated, where the correlation value is very low or lower (e.g. less than or equal to 6 in the example); even if the wave D1 slides, the correlation between the obtained wave E1 and the wave a is still low by performing the sliding despreading with the modulation code wave B. The principle of sliding solution expansion is as follows: the first 9 bits of D1 are modulated and despread with the wave B to obtain E1= 111001100, the second 2 nd to 10 th bits of D1 are modulated and despread with the wave B to obtain E1= 111001100, the third 3 rd to 11 th bits of D1 are modulated and despread with the wave B to obtain E1= 111001100, and so on until D1 is moved. And carrying out correlation operation on the wave E1 and the wave A one by one to check the correlation degree between the wave E1 and the wave A in any sliding process. When wave E1 is different from wave a, the correlation is always at a low level throughout the sliding process.

For another example, the interference signal is a single-frequency sequence, and is denoted as a wave D2, where the wave d2=111111111 (the same as the carrier frequency), and then the wave E2=d2=bχ 111001100, where the correlation between the wave E2 and the wave a is calculated with a low correlation value (e.g. up to 5 in the example), so that even if the received echo signal is consistent with the carrier, but does not conform to the modulation rule of the modulation code, the finally obtained correlation is still low and is not the designated echo;

for another example, the other interference signal is a spreading sequence, denoted as D3, and in the example, the wave d3= 111000110, where the wave e3=d3=bjjjjv-111110110, and the correlation between the wave E3 and the wave a is calculated to be low (e.g. up to 6 in the example), so that even if the received echo signal is a signal containing multiple frequencies, the modulation rule of the modulation code is not met, the correlation obtained finally is still low, and the echo is not specified. It should be noted that, all echoes will perform sliding despreading, if signals exist in front and back signals of the corresponding wave, the signals of the corresponding wave and the wave B will be selected for modulation despreading, if one signal includes the waves of D1, D2 and D3 in time sequence, the first 9 bits of D1 and the wave B will be modulated despread, and the modulated despread signals will be output to the next node; the method comprises the steps of continuing to perform modulation and despreading … on the 2 nd bit to 10 th bit of D1 and the wave B, performing modulation and despreading on the 11 th bit to 18 th bit of D1 and the D2 1 st bit and the wave B after the modulation and despreading … on the 10 th bit to 18 th bit of D1 and the wave B are finished, performing modulation and despreading … on the 2 nd bit to 18 th bit of D2 and the D2 1 st bit to the wave B, performing modulation and despreading on the D2 nd bit to 9 bit of D2 and the D3 1 st bit to the wave B after the modulation and despreading on the D2 3 rd bit to 9 bit and the D3 1 st bit to 2 nd bit to the wave B are finished, and performing modulation and despreading on the D3 nd bit to 9 bit to the wave B if no signal is generated after the modulation and despreading on the D3 bit to 9 th bit to the wave B are finished, performing modulation and despreading on the D3 bit to 9 th bit to the D2 to the wave B are smaller and less, and performing modulation and despreading on the D3 bit to the wave B to the D3 bit to the wave B are not overlapped.

It can be appreciated that if the ultrasonic signal received by the second ultrasonic transducer 202 includes a modulated wave, then the despread wave will have a frequency consistent with the carrier wave; if the ultrasonic signal received by the second ultrasonic transducer 202 contains other non-designated echoes, then the despreading process will spread (i.e., break up) again, either the single frequency signal or the spread spectrum signal, so that no wave is obtained having a frequency consistent with the carrier wave. As shown in fig. 7, therefore, the embodiment of the present application can realize the judgment of whether the signal is an interference signal, and the accuracy, precision and recognition effect are excellent.

In a possible embodiment, as shown in fig. 8, the reference signal is a modulated wave or a modulated orthogonal wave orthogonal to the modulated wave, for example, the input end of the correlation calculation module 5 is electrically connected to the output end of the sampling module 4.

Specifically, in the structure shown in fig. 8, the correlation between the sampled signal and the modulated wave may be directly calculated, so as to determine whether the signal received by the second ultrasonic transducer 202 is the signal transmitted by the first ultrasonic transducer 201. For example, since wave c= 111001100 and wave a=wave B, the correlation computation of wave D and wave C is equivalent to calculating the correlation of wave a×wave B and wave D, that is, calculating wave a×wave b×wave d=wave a (wave b×wave D), and doing the correlation computation of wave D and wave C is equivalent to including the despreading process in the above scheme, and the specific process is not repeated as above. Only the correlation operation is described here.

As can be seen from the above, the correlation value f=wave a (wave b×wave D) =111111111 (111001100 ×wave D).

For example, wave d1= 111111111111111111, wave b= 111001100, and the correlation value f1=111111111×111001100 is very low (e.g., up to 5 in the example);

for example, wave d2=111111111, wave b= 111001100, and correlation value f2=111111111×111001100, where the correlation value is low (as in the example, highest is 5);

for example, wave d3= 111000110, wave b= 111110101, and correlation value f3=111111111×111110101, where the correlation value is low (as in the example, up to 7);

for example, wave d4= 111001100, wave b=111111111, and correlation value f4=111111111×111111, where the correlation value is the highest (e.g., 9 in the example).

Therefore, the embodiment corresponding to the structure shown in fig. 8 can also realize the judgment of whether the signal is an interference signal. The modulation wave and the sampling signal are directly used for carrying out correlation operation, so that the modulation and despreading process of the sampling chip can be reduced, and the connection relation between the hardware circuit and the circuit is simpler. In the above patent, the correlation calculation module includes a convolution operation logic circuit to calculate the correlation.

In one possible embodiment, a second timer can also be provided in the ultrasonic sensor chip 10, which second timer is associated with a preset value of the correlation, which preset value of the correlation decreases with increasing time as the ultrasonic echo signal is weaker, i.e. the preset value comprises a plurality of different values. Instead of setting the second timer, the preset value of the correlation may be related to time, and the preset value is directly stored in the memory, where a plurality of different values are set, where the values are used to mark the preset value, and the preset values of different addresses in the memory are read along with the lapse of the clock, where the preset values are related to time, and generally, the preset values are smaller and smaller along with the lapse of the clock. In addition, the memory can store data of the relation between time and a preset value, and the correlation degree is calculated by reading the time and the preset value. The memory for storing the preset value may be the same memory module as the memory module 81 described below, may be a different address, or may be a memory module independent of the memory module 81 described below, but the same memory module is also an independent memory module, and is simply physically divided.

When the correlation preset value related with time is set, the storage module should be electrically connected with the processing module 6, the processing module 6 reads the preset value information in the storage module, and compares the correlation information output by the correlation calculation module with the preset value so as to judge whether a specified echo exists.

The technical effects of the embodiments of the present application will be further described below, for example, in an embodiment corresponding to the configuration shown in fig. 8, whether the despread sampling signal (wave E) is derived from the ultrasonic wave emitted by the first ultrasonic transducer 201 is determined by the correlation between the despread sampling signal (wave E) and the modulated wave (wave C). As shown in fig. 9, the despread sample signal (wave E) contains a specified echo, and during transmission or sliding, the echo signal is not aligned with the timing corresponding to the modulated wave (wave C), is gradually aligned, and is gradually further away from the alignment. For example:

the clock lengths of t0 and t1, and the time sequences corresponding to the despread sampling signal (wave E) and the modulated wave (wave C) are not aligned, so that the correlation degree is low;

t2 clock length, the despread sampling signal (wave E) is aligned with the corresponding timing of the modulated wave (wave C), so that the correlation is highest;

the clocks t3 and t4 are not aligned with the corresponding time sequence of the despread sampling signal (wave E) and the modulated wave (wave C), so that the correlation degree is low.

Therefore, not only the timing corresponding to the specified modulated wave (wave C) but also a high correlation degree occurs in the case where the phases are to be aligned, otherwise the correlation degree is low. If the sequence is long enough, the process of low-to-high correlation and high-to-low correlation basically does not occur, and even if the process occurs, the correlation of the two sides with the highest correlation is low and is easy to distinguish compared with the highest correlation. That is, in the embodiment of the present application, the time when the specified echo is received can be determined more accurately, so that the accuracy of calculating the obstacle distance based on the clock length when the specified echo is received is improved.

As can be seen from the above description, by performing phase modulation on the carrier wave, performing phase adjustment on the carrier wave to achieve a spreading effect, and then performing a despreading process on the echo signal, only the echo signal meeting the rule of modulation and despreading can obtain a higher correlation, that is, reach a preset value of the correlation, any other unspecified echo signal can be spread again by the despreading process, so that a high correlation value cannot be obtained, and whether a specified echo occurs can be judged through the correlation value. Because the phase is adjusted, if only a part of any echo does not meet the rule, the calculated correlation value is lower, and therefore, the echo signal with high correlation value is the appointed echo signal, thereby reducing the adverse effect of interference, noise and the like in the environment on the ultrasonic signal processing according to the determination of the appointed echo signal and improving the accuracy of the ultrasonic signal processing.

In addition, compared with the prior art, the embodiment of the application has the following beneficial effects:

1) The time of occurrence of the echo can be specified clearly, and the judgment logic is simpler. In the existing correlation calculation, when the correlation calculation is carried out on a locally stored signal and a received signal, the correlation calculation generally appears in a process from low to high and then from high to bottom, so that the judgment of the timing logic of selecting which correlation value to appear as an echo signal is complex, the timing of the echo signal appearance of the scheme is clear, and the judgment logic is simplified. If the carrier wave is long enough, the correlation degree is high only when the specified echo waveform occurs in the correlation degree operation, and the correlation degree of other waveforms is low because of the low possibility that waves with high consistency are emitted by the nature or other ultrasonic systems.

2) With the present embodiment, no filtering circuit (before or after sampling) may be added, because in the present embodiment, the waves received by the second ultrasonic transducer 202 are not originally echoes of a single frequency, and no filter is added to filter out extraneous waves. Irrelevant waves are filtered out when correlation operation is performed, the final result is not affected, and the hardware circuit overhead is saved.

3) In the embodiment of the application, the frequency is not changed by changing the phase of the carrier wave, so that the sampling frequency can be fixed during sampling, and the adopted frequency can be lower. If the frequency is adjusted in a frequency-adjusting mode, the sampling frequency is increased, otherwise, the real waveform cannot be reflected, the sampling frequency is adjusted in real time, or a higher sampling frequency is fixed, so that the hardware cost of sampling is larger; if a higher sampling frequency is fixed, the data processed by the subsequent correlation operation, peak value operation and the like can be too much, and the cost of a hardware circuit is further increased. For the embodiment of the application, only one frequency which is relatively low and can reflect the carrier wave waveform needs to be fixed, and the hardware is simpler.

4) In addition, the system has strong anti-interference performance, and allows multiple devices to work simultaneously. Because of the interference immunity of the spreading, multiple devices using mutually uncorrelated spreading code sequences can be allowed to operate simultaneously without interfering with each other.

5) The embodiment of the application can also effectively improve the influence of aftershock, thereby improving the judgment precision of the obstacle. Under the condition that the first ultrasonic transducer and the second ultrasonic transducer are the same sensor, after the ultrasonic sensor emits ultrasonic waves, the ultrasonic excitation signal stops, but as the ultrasonic sensor cannot stop immediately, aftershock can be generated, obstacles cannot be judged during the aftershock, and the judgment precision is reduced, namely the close-range judgment is influenced. The inventor finds that, because the amplitude of the aftershock vibration period changes along with the time and the frequency of the aftershock vibration period also changes, as described in the embodiment of the application, a high correlation cannot be obtained, so that the judgment of the specified echo is not basically affected by aftershock when the first ultrasonic transducer and the second ultrasonic transducer are the same sensor, thereby improving the detection precision. In addition, in the existing case of aftershock, an aftershock elimination circuit is basically additionally adopted, such as on-resistance to ground is increased, suppression signals are increased, the complexity of the circuit and the whole chip is additionally increased, and the processing circuit is not required to be additionally arranged, so that hardware expenditure is saved, and meanwhile, the circuit is simplified.

For the above 2), it is possible to eliminate the filter circuit, which is one of the advantages of the present application, but the present application does not exclude the addition of the filter circuit scheme.

As shown in fig. 10, since sampling is not necessarily performed according to the optimal phase angle, a shift of a certain phase angle occurs, for example, in an ideal case, 0 °, 90 °, 180 °, 270 ° each sample is a point, in an actual case, 20 °, 110 °, 200 °, 290 ° samples may occur, so that a final result of the correlation degree is deviated, and erroneous judgment occurs.

For example, a sine wave samples 4 points, the amplitude of the sine wave is 1V, then 0, 90, 180, 270 samples have values of 0V, 1V, 0V, -1V (a rule that the sine wave of the initial phase angle described above appears, and a rule that the sine wave of the phase inversion described above appears, if the sine wave of-1V, 0V, are shown). If 0V, 1V, 0V, -1V;0V, 1V, 0V, -1V; -1V, 0V, 1V, 0V then represent the occurrence of a 110 wave.

For simplicity of explanation, as shown in fig. 10 and table 1, the waveforms in the drawings show 110 waves, i.e., the designated echoes appear. In the ideal case, the waveform data obtained by sampling from 0 ° (waveform 1), from 30 ° (waveform 2), from 45 ° (waveform 3), and from 90 ° (waveform 4) are different, and an example of a cycle having a length of 4 clocks is described. The lower correlation degree appears when 45 degrees are sampled, and the correlation degree is 0 when 90 degrees are sampled; then, this result is excluded at this time, and it is considered that the specified echo does not occur, resulting in erroneous judgment.

TABLE 1

Therefore, in order to improve the misjudgment problem caused by the deviation of the sampling phase angle, in one possible implementation, as shown in fig. 11, the correlation calculation module 5 is specifically configured to calculate the first correlation between the timings corresponding to the sampling signal and the reference signal; calculating a second correlation degree between orthogonal time sequences corresponding to the sampling signal and the reference signal; and determining the sampling signal with the sum of the first correlation degree and the second correlation degree reaching a preset value as a specified echo. That is, the storage module 81 also stores a signal orthogonal to the reference signal, and the correlation calculation module 5 also reads the signal orthogonal to the reference signal for determining the correlation.

For example, the carrier-to-carrier timing is 0,1,0, -1,0,1, the carrier-to-orthogonal timing is 1,0, -1,0, the sigma carrier-to-carrier timing is equal to the carrier-to-orthogonal timing=0, as shown in table 2.

TABLE 2

The above data of wave 1, wave 2, wave 3, and wave 4 having sampling angles of 0 °, 30 °, 45 °, and 90 ° will be described as an example. Specifically, the results are shown in tables 3-1 and 3-2. The correlation degree 1 is the correlation degree of the carrier wave and the wave n, the correlation degree of the orthogonal time sequence corresponding to the carrier wave with the correlation degree of 2 bits is the correlation degree of the wave n, and the wave n is 1, 2, 3 and 4.

TABLE 3-1

TABLE 3-2

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It can be seen that, regardless of the phase angle of the samples, the sum of the first correlation obtained by performing the correlation operation on the despread sample signal and the timing corresponding to the carrier and the second correlation obtained by performing the correlation operation on the despread sample signal and the orthogonal timing corresponding to the carrier is always unchanged, which is 6 in the example. Therefore, the misjudgment problem caused by the deviation of the sampling phase angle is improved.

In a possible embodiment, as shown in fig. 12, before the correlation calculation, the modulation despreading module may not be provided, and the correlation calculation may be directly performed on the signal output by the sampling module 4. The scheme shown in fig. 12 is similar to the scheme shown in fig. 11, except that in the scheme shown in fig. 11, the correlation of the despread sampling signal is calculated, and in the scheme shown in fig. 12, the correlation of the sampling signal output by the sampling module 4 is calculated, but both the principles are similar, and the problem of misjudgment caused by sampling phase deviation is improved by using the correlation calculation of the orthogonal time sequences.

Since the further the obstruction is from the ultrasound system, the longer the ultrasound transmission time, the amplitude of the ultrasound signal received by the second ultrasound transducer 202 will decrease with increasing time. As shown in fig. 13, for example, the solid line waveform is an ultrasonic signal received by the second ultrasonic transducer 202 when the time from the first ultrasonic transducer 201 to the ultrasonic signal received by the second ultrasonic transducer 202 is 0, the amplitude thereof is the same as that of the ultrasonic signal transmitted by the first ultrasonic transducer 201 (actually, it is impossible to be 0 s), the middle broken line waveform is an ultrasonic signal received by the second ultrasonic transducer 202 when the time is 5ms, the broken line waveform closest to the origin is an ultrasonic signal received by the second ultrasonic transducer 202 when the time is 10ms, and as a result, as the time of the ultrasonic signal received by the second ultrasonic transducer 202 is later, the correlation with the carrier wave or the modulated wave is also lower, and therefore, a dynamic correlation threshold value can be set, which is related to the time, is decreased as the time increases, that is, the preset value of the correlation is set to be inversely related to the time of the second timer by using the above second timer (or directly storing the preset value related to the time). For example, in one possible embodiment, a plurality of different preset values are stored in the memory module 81, and the input of the processing module 6 is electrically connected to the output of the memory module 81 to read the preset values. However, setting the dynamically changing threshold requires more registers, memory, or more hardware circuit overhead.

Therefore, the embodiment of the application also provides another scheme for solving the problem of inaccurate judgment caused by the decrease of the amplitude of the ultrasonic signal along with time.

In one possible embodiment, as shown in fig. 14a, the ultrasonic sensor chip further includes: the symbol processing module 7 is arranged between the sampling module 4 and the correlation calculation module 5, the input end of the symbol processing module 7 is electrically connected with the output end of the sampling module 4, and the output end of the symbol processing module 7 is electrically connected with the input end of the correlation calculation module 5; the sign processing module 7 is configured to convert a positive value of the sampling signal into a first fixed value and convert a negative value of the sampling signal into a second fixed value. For example, the symbol processing module 7 may be located between the correlation calculating module 5 and the modulation despreading module 8, and for 0V in the despread sampling signal, the symbol processing module is unchanged and still takes 0V, and takes a first fixed value, such as-1V, if the symbol processing module is negative of-1V, -0.707V, -0.5V, and takes a second fixed value, such as 1V, if the symbol processing module is positive of 1V, 0.707V, 0.5V, and the like, and performs normalization processing similarly. Thus, the output is independent of the amplitude after being processed by the symbol processing module, regardless of the sampled value.

As shown in tables 4-1 and 4-2, a comparative example in which correlation operation was not performed for symbol extraction based on the scheme shown in fig. 11 is described by taking a 0 ° phase angle sample as an example. Tables 4-1 and 4-2 show that the sampling amplitude decreases with time, for example, 1V-0.7V-0.5V-0.3V (maximum value), and then the correlation between the timing corresponding to the carrier and the orthogonal timing corresponding to the carrier also decreases with time, 6-4.2-3-1.8. Then the dynamic correlation value is adjusted, which has large hardware cost, complex circuit and more complex logic operation.

TABLE 4-1

TABLE 4-2

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As shown in tables 5-1 and 5-2, in the embodiment of the present application shown in fig. 14a, in which the sign processing module processes the positive and negative values, it is understood that the sampled values used for the calculation are unchanged with the increase of time, and therefore, the sum of the correlations is independent of time. Therefore, a large number of hardware circuits can be saved, the chip area is saved, the cost is lower, and the logic operation is simpler.

TABLE 5-1

TABLE 5-2

In a possible embodiment, fig. 14b is a variation of fig. 14a, and the symbol processing module 7 may be further disposed between the sampling module 4 and the modulation despreading module 8, where the symbol processing module 7 is configured to convert a positive value of the sampling signal into a first fixed value, convert a negative value of the sampling signal into a second fixed value, and output the converted sampling signal to the modulation despreading module 8. This scheme is similar to that shown in fig. 14a, except that in the scheme shown in fig. 14a, the symbol extracts the modulated despread signal, and in the variant shown in fig. 14b, the symbol extracts the sampled signal.

In one possible implementation, as shown in fig. 15, the symbol processing module 7 may be further disposed between the sampling module 4 and the correlation calculation module 5, where the symbol processing module 7 is configured to convert a positive value of the sampled signal into a first fixed value, convert a negative value of the sampled signal into a second fixed value, and output the converted sampled signal to the correlation calculation module 5. The scheme shown in fig. 15 is similar to the scheme shown in fig. 14a, i.e. 14b, except that in the schemes shown in fig. 14a and 14b there is a modulation despreading module, and in the scheme shown in fig. 15 there is no modulation despreading module.

One chip width of the modulation code may be larger than one sine wave period of the carrier, such as one chip corresponds to a sine wave period of 2, 3, 4, … n carriers. In one possible implementation, one chip width of the modulation code is equal to one period of the carrier. Referring to fig. 9, a high degree of correlation occurs when a waveform and phase angle correlated signal occurs. However, since one sine wave has a plurality of sampling points, the correlation gradually starts to increase when the first sampling data of the last sine wave starts to have data matching, the correlation reaches the maximum when all the sampling data are matched, and as the wave moves, the matching degree decreases again so that the correlation decreases again. The time axis of the correlation peak is amplified, and the correlation peak with the highest correlation degree can appear to be similar to a triangle, namely, the process of the correlation degree from low to high and then from high to low. As shown in fig. 16. The timing of the occurrence of the correlation peak is precisely determined, the base of the triangle is compressed as much as possible, and the smaller the time is, the more precise the time is. At this time, setting the modulation code chip width equal to the sine wave period of one carrier can effectively lower the base of this triangle. And a sine wave samples n points, the bottom side of the triangle is composed of 2*n clock lengths, the highest point of the correlation peak appears between the n and n+1 clocks of the correlation peak, and the time determination accuracy can be controlled between plus and minus 1 clock length.

In one possible embodiment, during the process of sampling the ultrasonic signal received by the second ultrasonic transducer, the sampling period is one quarter of one sine wave period of the carrier wave.

Specifically, as described above, since phase modulation is employed, the sampling frequency is not very high or modulation is not required; the amplitude of the 4 points of one sine wave sample is 0V, 1V, 0V and-1V, and the amplitude of the 4 points of the sine wave after phase modulation is 0V, -1V, 0V and 1V, so that whether the sine wave of the initial phase or the sine wave after phase modulation is the sine wave after the initial phase can be clearly known through the four sampling points, namely whether the designated echo appears can be judged, and the problem of judgment deviation cannot occur due to low sampling. In the scheme in the prior art, in order to prevent erroneous judgment, the sampling rate is required to be very high, so that the requirement on sampling hardware is high, and the consumption of subsequent correlation calculation hardware is also larger; by adopting the scheme of the embodiment of the application, the cost of the hardware circuit can be greatly reduced.

In one possible embodiment, as shown in fig. 1, the ultrasonic sensor chip 10 may further include: the storage module 81 is electrically connected to the correlation calculation module 5, and the correlation calculation module 5 can perform correlation calculation according to the reference signal stored in the storage module 81. For the implementation mode provided with the modulation and despreading module 8, the information of the carrier wave and the modulation code is stored in the storage module 81, the modulation code is used for adjusting and despreading the received sampling signal, and the despread signal and the carrier wave are subjected to correlation calculation; the modulation and despreading module 8 is electrically connected to the storage module 81 for reading the modulation code and performing modulation and despreading on the sampled signal according to the modulation code, and the correlation calculation module 5 is also electrically connected to the storage module 81 for reading information related to the carrier (such as the carrier, or the carrier and the sequence information orthogonal to the carrier) and performing correlation calculation. For the embodiment where the modulation despreading module 8 is not provided, the storage module 81 stores therein information about the carrier wave and the modulation code, which is a modulated wave, because the modulated wave is obtained by phase modulating the carrier wave with the modulation code, and thus, the modulated wave is also one of the information about the carrier wave and the modulation code; the correlation calculation module 5 is electrically connected to the storage module 9 for reading information related to the modulated wave (such as the modulated wave, or the modulated wave and the sequence information orthogonal to the modulated wave) and performing the correlation calculation.

In addition, for the embodiment where the modulation despreading module 8 is provided, the storage module 81 may be electrically connected with the carrier generating module 1, the modulation code generating module 2 to store information corresponding to the carrier and the modulation code. For embodiments where the modulation despreading module 8 is not provided, the storage module 81 may be electrically connected to the phase modulation module 3 to store information corresponding to the modulated wave.

In addition, the sampling module 4 may be an analog-to-digital converter (ADC), and samples the analog signal to generate a digital signal through the analog-to-digital conversion function of the analog-to-digital converter, that is, the analog signal of the second ultrasonic sensor is converted into the digital signal through the analog-to-digital converter, so as to be used by each module.

In one possible implementation, the correlation calculation module 5 includes convolution operation logic.

In one possible embodiment, the first ultrasonic transducer 201 and the second ultrasonic transducer 202 are the same sensor.

The embodiment of the application also provides an ultrasonic signal processing method, which can be applied to the ultrasonic sensor chip, as shown in fig. 17, and includes:

step 101, generating a carrier wave;

102, generating a modulation code;

Step 103, modulating a carrier wave according to a modulation code to obtain a modulated wave, and outputting the modulated wave to a first ultrasonic transducer;

104, sampling an ultrasonic signal received by a second ultrasonic transducer to obtain a sampling signal;

step 105, determining the correlation degree of the sampling signal according to the reference signal, wherein the correlation degree is related to the modulation code, and the correlation degree is related to the carrier wave;

and 106, determining the sampling signal with the correlation degree reaching a preset value as a specified echo.

The specific process and principle of the method are the same as those of the scheme described in the above embodiment, and are not repeated here.

In a possible implementation manner, as shown in fig. 18, before determining the correlation degree of the sampling signal according to the reference signal in step 105, the method further includes: step 107, modulating and despreading the sampling signal according to the modulation code; the reference signal is a carrier or a carrier orthogonal wave orthogonal to the carrier.

In one possible implementation, as shown in fig. 19, in this procedure, there is no need to perform a modulation despreading process, and the reference signal is a modulated wave or a modulated orthogonal wave orthogonal to the modulated wave.

In one possible implementation, as shown in fig. 20, 21 or 22, the step 105 of determining the correlation of the sampling signal according to the reference signal includes: step 1051, calculating a first correlation between the time sequences corresponding to the sampling signal and the reference signal; step 1052, calculating a second correlation degree between the orthogonal time sequences corresponding to the sampling signal and the reference signal; step 106, determining the sampled signal with the correlation degree reaching the preset value as the specified echo includes: and determining the sampling signal with the sum of the first correlation degree and the second correlation degree reaching a preset value as a specified echo.

In one possible embodiment, as shown in fig. 18 and 20, the method further includes: before the step 107, the step 108 is executed to convert the positive value of the sampling signal into a first fixed value and convert the negative value of the sampling signal into a second fixed value; or, as shown in fig. 21 and 22, before calculating the correlation, step 108 is performed to convert the positive value of the sampling signal into a first fixed value and convert the negative value of the sampling signal into a second fixed value.

In a possible implementation, as shown in fig. 19 to 22, before determining the correlation of the sampling signal according to the reference signal in step 105, the method further includes: step 108, converting the positive value of the sampling signal into a first fixed value, and converting the negative value of the sampling signal into a second fixed value.

In one possible implementation, the modulation code comprises a first code value for flipping the carrier phase by 180 ° and a second code value for keeping the carrier phase unchanged during the modulation.

In one possible implementation, one chip width of the modulation code is equal to one period of the carrier.

In the embodiments of the present application, "at least one" means one or more, and "a plurality" means two or more. "and/or", describes an association relation of association objects, and indicates that there may be three kinds of relations, for example, a and/or B, and may indicate that a alone exists, a and B together, and B alone exists. Wherein A, B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship. "at least one of the following" and the like means any combination of these items, including any combination of single or plural items. For example, at least one of a, b and c may represent: a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, c may be single or plural.

The foregoing is merely a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and variations may be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. An ultrasonic sensor chip, comprising: the device comprises a driving circuit, a signal processing circuit and a storage module, wherein the driving circuit comprises a carrier wave generation module, a modulation code generation module and a phase modulation module, and the signal processing circuit comprises a sampling module, a correlation calculation module and a processing module;

The input ends of the carrier generating module and the modulation code generating module are used for being coupled to the micro-processing chip to receive the trigger signal, and the output ends of the carrier generating module and the modulation code generating module are electrically connected with the input end of the phase modulating module; the output end of the phase modulation module is used for being coupled to a first ultrasonic transducer; the input end of the sampling module is coupled to the second ultrasonic transducer, and the output end of the sampling module is electrically connected with the input end of the correlation calculation module; the input end of the storage module is electrically connected with the output end of the driving circuit, the output end of the storage module is electrically connected with the input end of the correlation calculation module, and a reference signal is stored in the storage module; the input end of the processing module is electrically connected with the output end of the correlation calculation module, and the output end of the processing module is used for being coupled to the micro-processing chip to send a feedback signal; wherein,,

the correlation calculation module reads the reference signal in the storage module to determine the correlation of the sampling signal, and inputs the correlation information to the processing module, wherein the correlation is related to the modulation code, and the correlation is related to the carrier;

2. The ultrasonic sensor chip of claim 1, wherein,

the storage module is also provided with a signal orthogonal to the reference signal, and the correlation calculation module is also used for reading the signal orthogonal to the reference signal and determining the correlation.

3. The ultrasonic sensor chip of claim 1, wherein,

the system further comprises a symbol processing module, wherein the input end of the symbol processing module is electrically connected with the output end of the sampling module, and the output end of the symbol processing module is electrically connected with the input end of the correlation calculation module; the sign processing module is used for converting the positive value of the sampling signal into a first fixed value and converting the negative value of the sampling signal into a second fixed value.

4. The ultrasonic sensor chip according to any one of claim 1 to 3, wherein,

the system further comprises a modulation despreading module, wherein the input end of the modulation despreading module is coupled to the output end of the sampling module, and the output end of the modulation despreading module is coupled to the input end of the correlation calculation module; the storage module is also used for storing the modulation code, and the input end of the modulation despreading module is also electrically connected with the output end of the storage module so as to read the modulation code;

the reference signal is the carrier or a carrier orthogonal wave orthogonal to the carrier.

5. The ultrasonic sensor chip according to any one of claim 1 to 3, wherein,

the reference signal is the modulated wave or a modulated orthogonal wave orthogonal to the modulated wave.

6. The ultrasonic sensor chip according to claim 1 or 2, wherein,

the storage module is used for storing a plurality of different preset values, and the input end of the processing module is electrically connected with the output end of the storage module so as to read the preset values.

7. The ultrasonic sensor chip according to any one of claim 1 to 3, wherein,

The signal input to the phase modulation module by the modulation code generation circuit comprises a first signal and a second signal, the phase modulation module receives the carrier information corresponding to the first signal output, and the phase modulation module receives the information of which the second signal output is 180 degrees different from the corresponding carrier.

8. The ultrasonic sensor chip of claim 7, wherein,

one chip width of the modulation code is equal to one period of the carrier wave.

9. The ultrasonic sensor chip of claim 8, wherein the ultrasonic sensor chip,

in the process of sampling the ultrasonic signal received by the second ultrasonic transducer, the sampling period is one quarter of one period of the carrier wave.

10. The ultrasonic sensor chip of claim 1, wherein,

the sampling module is an analog-to-digital converter.

11. The ultrasonic sensor chip of claim 1, wherein,

the correlation calculation module comprises a convolution operation logic circuit.

12. The ultrasonic sensor chip of claim 1, wherein the first ultrasonic transducer and the second ultrasonic transducer are the same sensor.

13. An ultrasonic radar apparatus, comprising:

the ultrasonic sensor chip according to any one of claims 1 to 12;

the output end of the second ultrasonic transducer is electrically connected to the input end of the ultrasonic sensor chip, and the ultrasonic sensor chip is used for sampling ultrasonic signals received by the second ultrasonic transducer.

14. The apparatus as recited in claim 13, further comprising:

the output end of the micro-processing chip is electrically connected with the input end of the ultrasonic sensor chip, and the input end of the micro-processing chip is electrically connected with the output end of the ultrasonic sensor chip; the ultrasonic sensor chip receives the trigger signal of the micro-processing chip to generate the modulated wave, and is further used for sending the feedback signal of receiving the specified echo to the micro-processing chip.

15. The apparatus of claim 13, wherein the device comprises a plurality of sensors,

The micro-processing chip comprises a first timer, and the micro-processing chip obtains the timing duration of the first timer and the received feedback signal to obtain the obstacle distance.

16. The apparatus of any one of claims 13 to 15, comprising a plurality of the ultrasonic sensor chips, a plurality of the first ultrasonic transducers, and a plurality of the second ultrasonic transducers.