JP6668409B2 - Ultrasonic sensing system and method - Google Patents

Description

  Proximity sensors such as ultrasonic sensors have been widely used to detect the distance to an object. In particular, ultrasonic sensors generally generate an ultrasonic signal by an ultrasonic transducer and receive an echo signal reflected back from an object. The distance to the object can be determined by calculating the time interval between the transmission of the ultrasonic signal and the reception of the echo signal based on the speed of propagation through a propagation medium such as air.

  Traditionally, the use of ultrasonic sensors is limited by the presence of dead zones caused by residual mechanical vibrations of the ultrasonic transducer. Ultrasonic transducers generally generate ultrasonic signals by high frequency vibration or resonance caused by an excitation signal. For example, a pulse of electrical energy can cause a piezoelectric transducer to vibrate piezoelectrically at a given frequency, thereby generating ultrasound. The echo of the propagated ultrasound signal reflected by the object can then be detected and evaluated to determine the distance to the object. However, even when the excitation signal (eg, electrical signal) is removed, the vibration of the transducer does not usually stop immediately. Rather, due to elasticity, the transducer is generally damped, but continues to vibrate for a period of time. Such residual vibration or reverberation can be detected by an ultrasonic sensor. Reverberation signals can obscure detection of echo signals. The dead zone is an area surrounding the ultrasonic transducer, in which the echo signal cannot be reliably detected in distinction from the reverberation signal.

  Existing methods attempt to solve the blind zone problem using either software or mechanical approaches. In a software approach, the detection of ultrasound signals does not work during periods corresponding to dead zones, in order to avoid detecting reverberation signals as echo signals. However, the software approach simply avoids detecting and does not reduce or eliminate dead zones. That is, an object located in the blind zone cannot be reliably detected. Using mechanical techniques, the receiver probe of the ultrasonic sensor can be padded or otherwise protected using a physical barrier. While this approach can reduce or eliminate dead zones by reducing the amplitude of the reverberant signal reaching the receiver probe, it can increase manufacturing complexity and cost.

  The present invention provides methods and systems that reduce or even eliminate blind zones, thereby reducing the minimum measurement distance without increasing production costs. Unlike the software approach described above, the present invention allows for the detection of objects located in blind zones, effectively reducing or eliminating dead zones. In addition, the present invention is implemented at the circuit level, thereby avoiding the additional production costs associated with the mechanical approaches described above.

  According to one aspect of the present invention, an ultrasonic sensing system is provided. The ultrasonic sensing system includes an ultrasonic transmitter that provides the transmission of an ultrasonic signal, an ultrasonic receiver that receives an ultrasonic signal including a reverberation signal and an echo signal as a result of the transmission, and an ultrasonic transmitter through a switch. An attenuator circuit connected to the receiver, wherein the attenuator circuit for attenuating the received ultrasonic signal and a switch are controlled to control the ultrasonic receiver only during a predetermined period after the transmission of the ultrasonic signal. A microcontroller unit (MCU) electrically connected to the attenuator circuit.

  In some embodiments, the ultrasound transmitter is an ultrasound receiver. The predetermined period can correspond to a period during which a reverberation signal can be detected. The predetermined period can correspond to a dead zone period.

  In certain embodiments, the attenuator circuit is selected based at least in part on a previously measured amplitude of the reverberant or echo signal.

  In some embodiments, the switches include single pole double throw (SPDT) switches.

  In certain embodiments, the ultrasound sensing systems described herein further comprise a booster that increases an energy level associated with emitting the ultrasound signal. Boosters increase the power level of electrical signals that can be used to cause the emission of ultrasonic signals.

  In certain embodiments, the ultrasound sensing systems described herein further comprise a gain-adjustable amplifier that amplifies the echo signal.

  In some embodiments, the MCU further controls the gain-adjustable amplifier to vary its gain based at least in part on a timer value corresponding to the measured distance from the ultrasound sensing system. The MCU may control the gain adjustable amplifier based on previously measured data.

  In certain embodiments, the MCU may further control the switch to allow the ultrasound receiver to gain adjust after a predetermined period of time without electrically connecting the attenuator circuit to the gain adjustable amplifier. It is electrically connected to the amplifier.

  In certain embodiments, the ultrasound sensing system described herein further comprises a comparator connected to the gain adjustable amplifier that compares the output of the gain adjustable amplifier to a predetermined threshold. The MCU further controls the gain of the gain-adjustable amplifier based at least in part on the output of the comparator. The comparator may or may not be integrated with the MCU.

  In certain embodiments, the ultrasound sensing system described herein further comprises an analog-to-digital converter (ADC) connected to the gain-adjustable amplifier that converts the output of the gain-adjustable amplifier to a digital value. Is provided. The gain adjustable amplifier can be controlled based at least in part on the output of the ADC. The ADC may or may not be integrated with the MCU. In some embodiments, the comparator and the ADC are used together to determine the occurrence of a peak amplitude.

  According to another aspect of the present invention, there is provided a method of sensing ultrasound. The method comprises the steps of detecting a signal after terminating the transmission of the ultrasound signal, wherein the detected signal may be an echo signal or a reverberation signal; Determining whether or not the signal has occurred within a predetermined time period from the end of the signal transmission; and, in response to the determination that the signal detection has occurred within the predetermined time period, reducing interference caused by reverberation from the transmission of the ultrasonic signal. Attenuating the detected signal to sufficiently reduce it, and detecting the signal without attenuating to determine the proximity of the object in response to the determination that signal detection has occurred after a predetermined period of time. Processing the obtained signal.

  In certain embodiments, the predetermined period corresponds to a period during which reverberation is detectable. In certain embodiments, the predetermined period corresponds to a dead zone period.

  In some embodiments, the ultrasound signal emitted by the emission is amplified prior to emission of the ultrasound signal using, for example, a booster.

  In certain embodiments, attenuating the detected ultrasound signal is based at least in part on the amplitude of one or more previously measured signals. Previously measured signals may include reverberation signals, echo signals, or both.

  In some embodiments, processing the detected ultrasound signal includes using a comparator and an analog-to-digital converter (ADC) to determine the occurrence of a peak amplitude. A multi-controller unit (MCU) may include none, one, or both comparators and ADCs.

  The methods described herein can further include providing a gain to the detected ultrasound signal based at least in part on previously measured data. Previously measured data can correlate the measured distance and the appropriate gain to the measured distance.

  The method described herein can further include providing a gain to the detected ultrasound signal based at least in part on the timer value.

  According to another aspect of the present invention, there is provided an ultrasonic sensing system. The system includes an ultrasonic transmitter that provides transmission of an ultrasonic signal, an ultrasonic receiver that receives an ultrasonic signal generated as a result of transmission, including a reverberation signal and an echo signal, and an ultrasonic receiver. A connectable attenuator circuit, the attenuator circuit operable to reject substantially all of the reverberant signal without rejecting the echo signal. In some embodiments, the ultrasound transmitter is an ultrasound receiver.

  The attenuator circuit can be connected to the ultrasonic receiver only during a predetermined period. The predetermined period corresponds to a dead zone period. The attenuator circuit can be selected based at least in part on a previously measured amplitude of the signal, such as a reverberation signal or an echo signal.

  In certain embodiments, the ultrasound sensing systems described herein further comprise a booster that increases an energy level associated with emitting the ultrasound signal. Boosters increase the voltage level of an electrical signal that can be used to cause the emission of an ultrasonic signal.

  In certain embodiments, the ultrasonic sensing system described herein further controls a switch to electrically connect the ultrasonic receiver with the attenuator circuit only during a predetermined period after the transmission of the ultrasonic signal. A microcontroller unit (MCU) connected to the The switches can include single pole double throw (SPDT) switches.

  In certain embodiments, the ultrasound sensing system described herein is further a gain-adjustable amplifier connectable to an ultrasound receiver via a switch and connected in series with an attenuator circuit. And an amplifier for amplifying an echo signal and having an adjustable gain.

  In some embodiments, the MCU further controls the gain-adjustable amplifier to vary its gain based at least in part on a timer value corresponding to the measured distance from the ultrasound sensing system. The MCU may control the gain adjustable amplifier based on previously measured data.

  In certain embodiments, the MCU may further control the switch to allow the ultrasound receiver to gain adjust after a predetermined period of time without electrically connecting the attenuator circuit to the gain adjustable amplifier. It is electrically connected to the amplifier.

  In certain embodiments, the ultrasound sensing system described herein further comprises a comparator connected to the gain adjustable amplifier that compares the output of the gain adjustable amplifier to a predetermined threshold. The MCU further controls the gain of the gain-adjustable amplifier based at least in part on the output of the comparator. The comparator may or may not be integrated with the MCU.

  In certain embodiments, the ultrasound sensing system described herein further comprises an analog-to-digital converter (ADC) connected to the gain-adjustable amplifier that converts the output of the gain-adjustable amplifier to a digital value. Is provided. The gain adjustable amplifier can be controlled based at least in part on the output of the ADC. The ADC may or may not be integrated with the MCU. In some embodiments, the comparator and the ADC are used together to determine the occurrence of a peak amplitude.

  According to another aspect of the present invention, there is provided a method for sensing ultrasound. The method comprises the steps of detecting an ultrasonic signal after terminating the transmission of the ultrasonic signal, wherein the detected ultrasonic signal is an echo signal or a reverberant signal; To thereby substantially eliminate reverberation signals without rejecting echo signals. In some embodiments, the attenuation of the detected ultrasound signal is applied only within a predetermined time period from the emission of the ultrasound signal. The predetermined period can correspond to the dead zone period.

  In some embodiments, the ultrasound signal emitted by the emission is amplified, eg, by a booster, prior to emission of the ultrasound signal.

  In certain embodiments, the step of attenuating the detected ultrasound signal is based at least in part on a previously measured amplitude of the reverberant or echo signal.

  In certain embodiments, the methods described herein further include using a comparator and an analog-to-digital converter (ADC) to determine the occurrence of the peak amplitude. A multi-controller unit (MCU) may include none, one, or both comparators and ADCs.

  In certain embodiments, the methods described herein further comprise providing a gain to the detected ultrasound signal based at least in part on previously measured data. Previously measured data can correlate the measured distance and the appropriate gain to the measured distance.

  In certain embodiments, the methods described herein further include providing a gain to the detected ultrasound signal based at least in part on the timer value.

  According to another aspect of the present invention, there is provided a method for sensing ultrasound. The method includes adjusting an amplifier to provide a first gain to a received ultrasound signal based at least in part on previously measured adjustable gain control (AGC) data; Adjusting the amplifier at a later point in time to provide a second gain that is greater than the first gain based at least in part on the measured AGC data. The previously measured AGC data can correlate the measured distance and the appropriate gain to the measured distance. For example, the gain can be increased, at least in part, as the measurement distance increases.

  In certain embodiments, the methods described herein further adjust the amplifier to provide increasing gain over time until the echo signal is detected or a predetermined measurement time is reached. Including steps.

  In some embodiments, the received ultrasound signal is attenuated before amplification, only if the ultrasound signal was received during a predetermined time period. During a predetermined period of time, the received ultrasound signal may be attenuated to eliminate substantially all reverberation signals without rejecting echo signals.

  In certain embodiments, the received ultrasound signal is attenuated based at least in part on a previously measured amplitude of the reverberant or echo signal. The predetermined period may include a dead zone period.

  In certain embodiments, the methods described herein further include using a comparator and an analog-to-digital converter (ADC) to determine the occurrence of the peak amplitude. A multi-controller unit (MCU) may include none, one, or both comparators and ADCs.

  It should be understood that different aspects of the invention may be recognized individually, collectively, or in combination with one another. The various aspects of the invention described herein can be applied to any of the specific applications described below. Other objects and features of the present invention will become apparent by a review of the specification, claims, and accompanying drawings.

(Embed by reference)
All publications, patents, and patent applications mentioned in this specification are to the extent that each individual publication, patent, or patent application is specifically and individually indicated and incorporated by reference. Incorporated herein by reference.

  The novel features of the invention are set forth with particularity in the appended claims. The features and advantages of the present invention will be better understood with reference to the following detailed description, which illustrates exemplary embodiments that utilize the principles of the present invention, and the accompanying drawings, in which:

FIG. 3 illustrates an ultrasonic sensor according to one embodiment of the present invention. FIG. 4 illustrates a signal detected by an ultrasonic receiver as a result of an ultrasonic transmission, according to an embodiment of the present invention. 4 is a flowchart illustrating the steps of a method for achieving blind zone reduction or elimination, according to one embodiment of the present invention. FIG. 2 illustrates a circuit diagram of an ultrasonic sensing system according to one embodiment of the present invention. FIG. 4 is a diagram illustrating AGC gain values (AGC values) corresponding to various measurement distances according to an embodiment of the present invention. 4 is a flowchart illustrating steps of a method for implementing time-based gain control according to one embodiment of the present invention. 5 is a flowchart illustrating steps of a method for determining occurrence of a peak amplitude, according to one embodiment of the present invention.

  Methods, systems, and devices that reduce or eliminate dead zones associated with ultrasonic sensors, thereby reducing the minimum measurement distance without reducing the maximum measurement distance and without increasing production costs I do. According to one aspect of the present invention, there is provided a method and system for reducing or eliminating dead zones associated with sensing ultrasound. In some embodiments, an attenuator circuit is introduced to attenuate signals received during periods corresponding to blind zones. The attenuator circuit removes substantially all reverberation signals when reflected from an object, while preserving substantially all echo signals. Selection and deselection of the attenuator circuit may be realized by a controllable switch. The amount of attenuation provided by the attenuator circuit may be configurable based on, among other factors, the values (eg, amplitude) of the actually measured reverberation and echo signals.

  According to another aspect of the present invention, there is provided a method and system for dynamically adjusting the gain of an echo signal to improve the accuracy of a proximity measurement. In particular, a gain-adjustable amplifier may be provided to amplify a received signal based on a current measurement distance indicated by the time elapsed since the start of the measurement. The amount of gain of the gain adjustable amplifier can be controlled by the controller based on the measured distance. The longer the measurement distance, the more the echo signal tends to be attenuated. Thus, more gain is provided by a gain-adjustable amplifier for amplifying the echo signal. In some embodiments, the amount of gain is adjusted periodically by the controller based on empirical measurement data.

  According to another aspect of the present invention, there is provided a method and system that uses an analog-to-digital converter (ADC) in conjunction with a comparator to improve the accuracy and precision of proximity measurements. In particular, a comparator can be used to trigger a proximity measurement. The ADC can be used to determine when a relative peak amplitude has been received within a predetermined time period. This point can then be used to calculate the distance to the object from which the echo signal was reflected. Specifying the time of peak amplitude improves the accuracy and precision of the proximity measurement.

  According to one aspect of the present invention, there is provided a method and system for increasing power associated with ultrasound transmission. For example, boosting the transmitted power is preferred to overcome the attenuation of audio signals in the surrounding environment and / or to increase the upper limit of the measurement range. To increase the transmitted power, the transmission circuit of the ultrasound system can include a booster that increases the electrical power used for transmission. In one embodiment, the booster can be realized by a transformer (eg, a step-up transformer) that increases the voltage level of the electrical signal provided by the controller.

  It should be understood that different aspects of the invention may be recognized individually, collectively, or in combination with one another. The various aspects of the invention described herein can be applied to any of the specific applications described below. Other objects and features of the present invention will become apparent by a review of the specification, claims, and accompanying drawings.

  FIG. 1 is a diagram illustrating an ultrasonic sensor 100 according to an embodiment of the present invention. The ultrasonic sensor 100 includes a transmitter 102 and a receiver 104. An ultrasonic transmitter converts an electric signal into an audio signal, while an ultrasonic receiver converts an audio signal into an electric signal. In some examples, the ultrasound receiver and the ultrasound transmitter are implemented as separate devices. In another example, the ultrasound receiver and the ultrasound transmitter are implemented by the same device that can both emit and receive ultrasound signals. As used herein, the term ultrasonic transducer can refer to an ultrasonic transmitter, an ultrasonic receiver, or both. The arrow from the ultrasonic transmitter 102 to the ultrasonic receiver 104 illustrates a reverberation 106 that can reach the ultrasonic receiver, for example, after the transmitter 102 has stopped actively transmitting ultrasonic signals.

  In certain embodiments, an ultrasonic transducer (eg, an ultrasonic transmitter, an ultrasonic receiver, or both) can be constructed using piezoelectric principles. For example, ultrasonic transducers include piezoelectric transducers that are made of natural or synthetic materials that exhibit piezoelectricity. This material can be, for example, certain crystals (eg, quartz, berlinite, saccharose, Rochelle salt, topaz, or tourmaline mineral), bone, biological materials (eg, tendon, silk, wood, enamel, dentin) , Or DNA), synthetic crystals (eg, gallium orthoester, or langasite), synthetic ceramics (eg, lead zirconate titanate, barium titanate, lead titanate, potassium niobate, lithium niobate, lithium tantalate, Sodium tungstate or zinc oxide), polymers (eg, polyvinylidene fluoride), organic nanostructures, and the like.

  Alternatively, ultrasonic transducers can be constructed using non-piezoelectric principles. For example, an ultrasonic transducer can include a magnetostrictive material that changes size when exposed to a magnetic field. As another example, an ultrasonic transducer includes a condenser microphone that uses a thin plate that moves in response to ultrasonic waves and changes an electric field around the thin plate to convert an audio signal into an electric signal.

  FIG. 1 also illustrates hardware pins provided by an exemplary ultrasonic proximity sensor board. In various embodiments, the definition of the hardware pins can be defined according to the specific requirements of the actual application. In various embodiments, more hardware pins, fewer hardware pins, or at least one of different hardware pins may be provided. In the embodiment shown in FIG. 1, the hardware pins are defined as follows.

  Vcc-power supply (voltage is defined by actual requirements).

  Trig / Tx-UART (universal asynchronous receiver / transmitter) terminal used to transmit an external logic trigger / measurement result or response to an external command to start a measurement.

  Echo / Rx-UART receiving terminal used to receive measurement results / commands, expressed as pulse width.

  GND-Reference ground for power and signals.

FIG. 2 is a diagram illustrating a signal detected by an ultrasonic receiver as a result of ultrasonic transmission, according to an embodiment of the present invention. As illustrated, the excitation electrical signal or drive pulse 202 causes the ultrasonic transmitter to vibrate and emit an ultrasonic signal. Drive pulse 202 is removed around time _{t 1.} However, the transmitter does not stop oscillating immediately even if the drive pulse 202 is removed (ie, the voltage level is zero). Instead, the transmitter continues to ring down or vibrate residually, causing a residual vibration or reverberation signal 214 that may be received by the ultrasound receiver. The signal level received by the receiver probe is represented by 210. The reverberation may last for a period of t _b = t ₂ −t ₁ , during which time the reverberation signal is true if the signal is not suppressed (eg, if the amplitude of the signal is not apparently attenuated). May obscure the reception of the echo signal. Therefore, the period t _b is called a dead zone period or dead zone period indicates a period that can not be reliably detected by the echo signal to distinguish from the reverberation signal. During the dead zone period, the reverberation signal is not suppressed and may be strong enough (eg, may have sufficient amplitude) to trigger the comparator threshold or trigger level 208. Such a comparator trigger threshold is often used to determine whether a true echo signal has been received.

Based on the speed of sound c, the dead distance d _b from the ^{_{transducer, d b = 1/2 *}} c * t b in can be calculated, within its scope, obscured by the echo reverberation signals from the object The object cannot be detected accurately. In other words, the objects in the blind zone, the time ultrasonic signal to return to the transducer to reach the object is less t _b. The dead zone refers to the area surrounding the transducer contained in the transmission (ie, the dead zone), in which the presence of reverberation tends to obscure the echo from the object, making it impossible to accurately detect the object. As used herein, the term dead zone period is used to refer to t _b. While the transducer is ringing down, it hinders or obscures the detection of the true echo signal. In various embodiments, the shape or size of the blind zone can be determined by the propagation medium, the material or location of the transducer, the characteristics of the excitation signal, and other factors. In general, it is desirable to reduce or eliminate dead zones to increase the detectable range of the proximity sensor, especially for short distance detection.

  FIG. 2 shows the receiver signal in two exemplary situations. In a first scenario 204, the object is located beyond the dead zone of the transducer. Thus, echo signal 216 occurs after the occurrence of reverberation signal 214 and after the dead zone period. As illustrated, when the object is located beyond the dead zone, the echo signal from the object is not obscured by the reverberation signal.

  In the second scenario 206, the object is located within the dead zone of the transducer. As a result, echo signal 216 occurs during the same blind zone as reverberant signal 214. Obviously, in the illustrated scenario, if the reverberation signal 214 is not suppressed, it may obscure or prevent detection of the true echo signal 216.

  In both exemplary cases, the reverberation signal 214 is shown to be suppressed or otherwise attenuated below the trigger value 208 (eg, by a hardware attenuator circuit). Thus, the reverberation signal does not falsely trigger the comparator. As will be described in more detail, such attenuation of signals received during dead zone times can be used to effectively reduce or eliminate the effects of dead zones.

  Using the attenuation technique of the present invention, the true echo signal may also be attenuated if it occurs during blind zones. However, the echo signal is generally stronger than the reverberation signal, especially within short distances. Thus, to remove the reverberation signal (eg, reduce the amplitude below the comparator trigger value), while preserving the true echo signal (eg, still keep the amplitude above the comparator trigger value). In addition, it is possible to attenuate the reverberation signal. The reverberation is generally already attenuated by the time it reaches the receiver probe. Other factors contributing to the reduction of the power of the reverberation signal include at least one of the distance between the receiver and the transmitter, the launch angle of the transmitter, or another factor. For example, the launch angle of an ultrasonic transmitter generally cannot reach 180 degrees. Exemplary firing angles include, but are not limited to, 30, 60, 90, 120, and 150 degrees. In contrast, echoes reflected by objects located near the receiver (ie, the dead zone) are generally not very attenuated and generally enter the receiver directly at a very small angle, Keep most of the signal power. Based on these factors, the echo signal is generally stronger than the reverberant signal detected during the dead zone period. Thus, by adjusting the amount of attenuation, it is possible to remove substantially all of the reverberation signal while preserving most of the echo signal within the dead zone period. As shown in scenario 206, reverberation signal 214 can be substantially or completely rejected (eg, of attenuated reverberation signal 214) even when attenuated by an attenuator circuit connected to the receiver. The amplitude is less than the trigger value 208). On the other hand, the true echo signal 216 can be substantially preserved (eg, the amplitude of the attenuated echo signal is still greater than the trigger value 208).

  In accordance with one aspect of the present invention, methods and systems are provided for reducing or eliminating blind zones in a proximity sensing system. FIG. 3 shows a process 300 illustrating steps of a method for achieving blind zone reduction, according to one embodiment of the present invention. Some or all aspects of process 300 (or at least one of the other processes described herein, or variations, or combinations thereof) may include one or more executable instructions. It can be under the control of a computer, processor, or control system. Also, aspects include code (eg, executable instructions, one or more computer programs, or one or more applications) that selectively executes on one or more processors, by hardware, or a combination thereof. It can be realized as The code may be stored on a computer-readable storage medium, for example, in the form of a computer program including a plurality of instructions executable by one or more processors. Computer readable storage media can be non-transitory. The order in which the operations are described are not intended to be construed as limiting, and any number of the described operations may be performed in any order or parallel, and / or in order to implement the process. Can be combined. For example, aspects of process 300 can be implemented by components of an ultrasonic sensor system, as illustrated in FIG.

  In one embodiment, the process 300 detects the signal at step 302 after the end of the transmission of the ultrasound signal. The transmission of the ultrasonic signal can occur in the manner described in FIGS. For example, a pulse of electrical energy can be applied to a piezoelectric transmitter that causes it to vibrate or resonate, thereby generating sound waves. When electrical energy is removed from the transmitter, transmission is deemed terminated. However, as discussed above, the vibration or resonance of the transmitter does not stop immediately. Rather, the transmitter will continue to oscillate even if the amplitude decays over a period of time. Such reverberation can be detected by a receiver and converted to an electrical signal (ie, a reverberant signal). If the transmitted ultrasound signal is reflected by an object, the echo can also be detected by the receiver and converted to an electrical signal (ie, an echo signal). From a receiver perspective, the detected electrical signal may be an echo signal or a reverberation signal.

The process 300 further determines, at step 304, whether the detected signal was detected within a dead zone period associated with the ultrasonic sensor, as discussed in FIG. For example, it can be determined whether the detection of the signal has occurred within a predetermined period from the end of the transmission of the ultrasonic signal. Predetermined period of time corresponds to the dead zone period, it time discussed above with intervals t _b in FIG. In one implementation, the timer associated with the ultrasonic sensor is started at the end of the transmission of the ultrasonic signal or at the start of the transmission. The current timer value is compared to a predetermined dead zone period (eg, t _b ) to determine whether a signal was detected during the dead zone period.

  If the signal is detected within the dead zone period, the detected signal is attenuated at step 306 to reduce the power (eg, amplitude) of the signal. The detected signal may be an echo signal or a reverberant signal that is attenuated during the dead zone period. However, within short distances, the echo (and the detected echo signal) tends to be stronger than the reverberation (and the detected reverberation signal). This is because the reverberation is generally already attenuated by the time it reaches the receiver probe. Other factors contributing to the reduced power of the reverberation signal include at least one of the distance between the receiver and the transmitter, the launch angle of the transmitter, or other factors. For example, the launch angle of an ultrasonic transmitter generally cannot reach 180 degrees. Exemplary firing angles include, but are not limited to, 30, 60, 90, 120, and 150 degrees. In contrast, echoes reflected by objects located near the receiver (ie, the dead zone) are generally not very attenuated and generally enter the receiver directly at a very small angle, Keep most of the signal power. Based on these factors, the echo signal is generally stronger than the reverberant signal detected during the dead zone period. Therefore, by adjusting the amount of attenuation, substantially all reverberation signals can be removed. On the other hand, it is possible to save most of the echo signals within the dead zone period.

In one embodiment, the amount of attenuation is selected based on the amplitude of at least one of the actually measured reverberation signal or echo signal. For example, the maximum amplitude based on the actual measured reverberation signal (or other suitable value) and is V _r, if the minimum threshold voltage for triggering a proximity measurement (hereinafter, the trigger value) is V _0, attenuation, in order to ensure that the amplitude of any vibration residual signal is reduced below the trigger value V _0, it may be set to more than V _r -V _0. On the other hand, the attenuation should be set to less than V _e -V ₀ to ensure that the echo signal, even after attenuation, is still strong enough to trigger a proximity measurement. Where V _e is the minimum amplitude (or other suitable value) based on the actually measured echo signal. Therefore, the amount of attenuation ΔV can be selected as follows.
_{V r -V 0 <ΔV <V} e -V 0

In an alternative embodiment, the attenuation is greater than the difference between the reverberation signal V _r and trigger value V ₀ which has received but can be selected so as not to fall below the difference between the echo signal and the trigger value received. However, the amount of attenuation still needs to be less than the minimum echo signal to preserve the echo signal. In other words,
ΔV> V _r −V ₀ ,
ΔV ≧ V _e −V ₀ and ΔV <V _e .

In another alternative embodiment, the attenuation ΔV can be set to be greater than the measured reverberation signal, such that V _r <ΔV <V _e . In various embodiments, at least one value of V _r , V _e , or V ₀ is determined based on test or calibration measurements. For example, any of the above values may be the average, middle, maximum, minimum, or any other derived value of the measured values.

  In some embodiments, after the attenuation has been applied, the reverberation signal may be reduced to zero, while the echo signal may be reduced to a non-zero value below the trigger value. In such embodiments, post-attenuation amplification may be required to cause the attenuated echo signal to exceed a trigger value to trigger the proximity measurement process. Amplification may also be needed to detect echo signals received outside of the dead zone period to compensate for attenuation caused by the propagation medium. In general, the further the object is from the ultrasound receiver, the more the echo signals reflected by the object are attenuated. To compensate for the greater attenuation of the echo signal, greater amplification or gain can be applied as the measurement range increases. Methods for providing dynamically adjusted gain control are discussed in more detail elsewhere in this disclosure.

  Still referring to FIG. 3, if it is determined that the detected signal was detected outside the dead zone period (e.g., the timer value is greater than the dead zone period), then the residual signal will be less than the minimum trigger value by then. Attenuation of the detected signal is unnecessary (ie, skipping step 306), since the detected signal is considered to be attenuated and the detected signal is probably an echo signal. In certain embodiments, attenuation is turned on and off according to a timer value and may be started at the beginning or end of the ultrasound transmission. When the timer value is within the dead zone period, attenuation is turned on to attenuate the received signal. When the timer value exceeds the dead zone period, the attenuation is turned off and the received signal is not further attenuated. In alternative embodiments, the attenuator may provide different degrees of attenuation during or beyond the dead zone. For example, a greater attenuation may be provided during a dead zone period than outside a dead zone period.

  Regardless of whether the signal is attenuated, process 300 further processes the signal at step 308. In some embodiments, processing the signal at step 308 can include amplifying the signal regardless of whether the signal is attenuated. As discussed above, such amplification may be necessary to increase the power of the echo signal to a level that is sufficient to trigger a proximity measurement process. In some embodiments, processing the signal at step 308 may include calculating a time between transmitting the ultrasound signal and receiving the echo, thereby measuring the distance to the object. As described in further detail below, methods are provided for increasing the accuracy and precision of proximity measurements.

  FIG. 4 illustrates a circuit diagram of an ultrasonic sensing system 400 according to one embodiment of the present invention. In certain embodiments, the ultrasound sensing system 400 may include more or fewer components than those shown in FIG. Ultrasonic sensing system 400 implements aspects of the technique discussed herein. For example, the ultrasound sensing system reduces or eliminates dead zones and increases the measurement range of the ultrasound sensing system, for example, by applying a time-based attenuation of the received signal, as discussed in FIG. be able to. Also, the ultrasound sensing system 400 may maintain and / or increase the upper limit of the measurement range of the ultrasound sensing system by at least one of increasing the energy of the ultrasound transmission and / or amplifying the received signal. Can be done. Ultrasound sensing system 400 also controls the dynamic gain of the received signal to determine the occurrence of peak amplitude, and uses an analog-to-digital converter (ADC) to improve the reliability and proximity measurement. Accuracy can be improved.

  The ultrasonic sensing system 400 includes an ultrasonic transmitter 402 and an ultrasonic receiver 404. The ultrasonic transmitter 402 is connected to a transmitter circuit, and the ultrasonic receiver 404 is connected to a receiver circuit. One or both of the transmitter circuit and the receiver circuit can be at least partially controlled by the controller 412. The ultrasonic transmitter 402 transmits an ultrasonic signal according to the electric signal, and the ultrasonic receiver 404 converts the received audio signal into an electric signal. For example, at least one of the ultrasonic transmitter 402 or the ultrasonic receiver 404 can be implemented by a piezoelectric transducer as discussed with respect to FIG. Although the ultrasound transmitter 402 and the ultrasound receiver 404 are illustrated as separate devices, in certain embodiments they can be implemented by a single device, such as a single piezoelectric transducer.

  According to one aspect of the present invention, there is provided a method and system for increasing power associated with ultrasound transmission. In some situations, boosting of the transmitted power is preferred, for example, to overcome the attenuation of audio signals in the surrounding environment or to increase the upper limit of the measurement range. For example, sound waves are absorbed by wave absorbing materials, such as carpets, sponges, and the like. Thus, when measuring proximity in a carpeted room, it may be necessary to increase the ultrasonic oscillation power to compensate for such attenuation. Also, the more power the transmitted voice has, the more likely it is that the voice will reach a distant object and echo will return at a detectable level. Therefore, by increasing the transmission power, the upper limit of the measurement range of the ultrasonic sensing system can be increased.

  To increase transmission power, the ultrasonic transmitter 402 can be connected to a booster circuit 422 (hereinafter booster) that increases the power used for transmission. In one embodiment, booster 422 may be implemented by a transformer (eg, a step-up transformer) that increases the voltage level of the electrical signal provided by the controller. Conventional inverter circuits can generally only supply twice the operating voltage to drive the ultrasonic transmitter. Such limited power increase in transmitted ultrasound may be insufficient to compensate for damping effects caused by wave absorbing materials such as sponges, carpets, and the like in the surrounding environment . In contrast, booster circuits can be boosted to an outgoing voltage as high as six times the operating voltage (or more, depending on the hardware design). The greatly improved transmitted power allows the reflected wave to be more easily received and used to trigger the receiving circuit, even when the wave absorbing material is present in the surrounding environment.

  Booster 422 increases the voltage level of the electrical signal, preferably the increased voltage level remains within the range of voltages associated with ultrasonic receiver 404. Further, additional mechanisms may be required (eg, when the drive current from controller 412 is not sufficient), and some of the transmitter circuitry may be used to increase output current and maximize transmit power. It can be realized as

  According to another aspect of the present invention, the ultrasound sensing system 400 may include a method for reducing the effects of blind zones, or for achieving zero blind zones (eg, reducing the size of blind zones to zero). I will provide a. This method may be similar to the method discussed in connection with FIG. As discussed above, reverberation can cause the generation of reverberation signals that can be mistaken for echo signals during blind zones. The present invention addresses the above problem at the circuit level by electrically connecting the ultrasonic receiver 404 with the attenuator circuit 408 only during the dead zone. As a result, substantially all, if not all, of the echo signal may be allowed to pass while attenuating or removing substantially all of the reverberation signal. Since attenuation of the received signal is achieved at the circuit level, the cost increase is small compared to the cost of mechanical suppression of reverberation discussed above.

  In one embodiment of the present invention, the ultrasonic receiver 404 is connected to the switch 406. Switch 406 is controllable by a switch control signal 420 provided by controller 412. The switch control signal 420 can cause the switch 406 to electrically connect the ultrasonic receiver 404 and the attenuator circuit 408 during the dead zone to attenuate the received signal. The switch control signal 420 can also cause the switch 406 to electrically disconnect the ultrasonic receiver 404 and the attenuator circuit 408 so that the received signal is not attenuated outside of the dead zone period. In some embodiments, the decision to connect or disconnect the attenuator circuit 408 is based on the value of a timer (not shown). For example, a timer can be started when the transmitter circuit stops causing the ultrasonic transmitter to emit an ultrasonic signal. As long as the accumulated timer value does not exceed the dead zone period, the switch 406 can keep the attenuator circuit 408 selected. However, when the timer value reaches or exceeds the dead zone period, switch control signal 420 causes switch 406 to disconnect from the attenuator circuit.

  In certain embodiments, switch 406 may include a single pole, double throw (SPDT) switch, or may include any number of poles and / or number of throws. In another embodiment, the switch may include a multiplexer (mux) demultiplexer (demux). Switch 406 may also include an electrical switch, such as a power metal oxide semiconductor field effect transistor (MOSFET), a solid state relay, a power transistor, an insulated gate bipolar transistor (IGBT), or the like.

  In various embodiments, the attenuator circuit 408 can include one or more passive components forming a voltage divider network to reduce the power of the electrical signal. For example, attenuator circuit 408 can include a diode and a capacitor, or a resistor and a capacitor. The components of the attenuator circuit may be arranged according to any arrangement, such as Π or T.

  In various embodiments, the parameters of the attenuator circuit 408 may be configurable to accommodate different situations in order to reduce or eliminate reverberation signals without rejecting echo signals. The parameters may be adjusted based on actual or previous measurements of at least one of the reverberation signal and the echo signal. For example, based on the amplitude of at least one of the actual reverberation signal or the echo signal (eg, as measured on an oscilloscope), the parameters of the passive components of the attenuator circuit may be as discussed in connection with FIG. , To achieve a desired amount of attenuation. For example, the capacitance of a capacitor or the resistance of a resistor may be selected to increase or decrease the total attenuation by at least one of less than a trigger value or near zero to reduce the amplitude of the reverberation signal. it can.

  In various embodiments, characteristics (eg, amplitude) associated with at least one of the actually measured reverberation signal or echo signal may be determined by various factors. These factors include the parameters or properties of the ultrasonic transmitter / receiver, the location or method of mounting the ultrasonic transmitter / receiver (eg, the distance between the transmitter and receiver probes, mechanical Vibration reduction is in place, etc.), propagation media, objects in the surrounding environment, and the like. For example, different ultrasound probes mounted using similar methods may produce different reverberation signals and / or echo signals. The same ultrasonic probe may produce different reverberation signals and / or echo signals when mounted differently.

  According to another aspect of the present invention, there is provided a method and system for dynamically adjusting the gain associated with the amplification of an echo signal to improve the accuracy and / or range of the proximity measurement. Existing ultrasonic sensors may include a fixed gain amplifier. The amount of gain is determined by the gain required to reach the maximum measurement distance. Under certain circumstances, such a fixed gain control can result in inaccurate measurement results. In particular, in a crowded environment, objects that are closer than the maximum measurement distance can cause false triggering of the comparator, resulting in inaccurate measurements. For example, during a proximity measurement to the ground, if there is a box on the ground that is within the range of the transmitter probe, the echo from the box will first be reflected by the receiver probe due to over-amplification caused by a fixed gain based on the maximum measured distance. Could be reached. In contrast, using the adjustable gain control approach described by the present invention, a gain value is provided based on the measured distance. Thus, shorter measurement distances are provided with less gain, thereby avoiding over-amplification of echoes from close-range objects. Thus, the measurement accuracy of the ultrasonic sensing system is improved by the present invention.

  In the illustrative embodiment, the ultrasound sensing system 400 includes a gain adjustable amplifier 410. The gain adjustable amplifier amplifies the received signal according to an adjustable gain control (AGC) signal 418 provided dynamically by controller 412. In one embodiment, the gain adjustable amplifier 410 can be electrically connected to the ultrasonic receiver 404 via the switch 406. During the dead zone, the gain adjustable amplifier 410 can be connected in series with the attenuator circuit 408 to amplify the signal attenuated by the attenuator circuit 408. Such post-attenuation amplification may be necessary to cause the attenuated echo signal to exceed a trigger value to trigger the proximity measurement process. A gain-adjustable amplifier 410 over the dead zone period can be used to directly amplify the received signal, bypassing the attenuator circuit 408 (eg, via the switch 406). Such amplification of echo signals received outside of the dead zone period can be used to compensate for attenuation caused by the propagation medium (eg, air, water), improving the range and accuracy of proximity measurements.

  In some embodiments, the gain provided by gain-adjustable amplifier 410 is dynamically adjusted based on the measured distance. As the ultrasound signal is emitted, the measured distance of the ultrasound sensing system increases as the emitted signal propagates further. The greater the measurement distance, the more the echo signal is attenuated due to the attenuation caused by the propagation medium. Therefore, it is generally necessary to provide more gain to the received signal to compensate for the increasing attenuation as the measurement distance increases over time. In one embodiment, the gain provided by the gain-adjustable amplifier 410 is dynamically adjusted to increase stepwise (according to the AGC signal 418) as the measurement distance increases. The adjusted gain may be equal to or greater than the gain previously provided.

  In some cases, the exact attenuation characteristics of the ultrasonic signal may vary depending on the propagation medium (eg, air, water), transmission frequency, transmitter / receiver characteristics, mounting methods, and other factors. Thus, the gain provided by the AGC signal 418 and the gain-adjustable amplifier 410 can be at a varying measurement distance to a trigger value (e.g., sufficient to trigger an interrupt by a comparator) or a detectable level. Until it is reached, it can be provided based at least in part on an empirical measurement of the actual operating gain required to enhance the received echo signal. Alternatively, the gain can be adjusted automatically based on the strength of the received signal. For example, the gain may be proportional to the strength of the received signal, for example, in a linear or exponential manner.

  FIG. 5 illustrates AGC gain values (AGC values) associated with various measurement distances or ranges, according to one embodiment of the present invention. For a given measurement distance or measurement range, the corresponding AGC gain to amplify the echo signal received from that measurement distance or measurement range to a detectable level (eg, above a trigger value defined by a comparator) Is required. The table on the left side of FIG. 5 shows the measurement range (“range”) in centimeters (cm) in the left column, and the corresponding AGC value (“POT AGC value”) in logarithmic decibels (dB) in the right column. . The AGC value can be derived based on the input echo signal and the output signal amplified by the gain-adjustable amplifier, and can indicate the degree to which the input signal has been amplified. In one embodiment, the AGC value may be measured by a potentiometer or other measuring device. Therefore, the data shown in FIG. 5 illustrates the correlation between the AGC value and the measured distance. The graph on the left side of FIG. 5 illustrates the same data. As shown in the table and graph of FIG. 5, the AGC value generally increases as the measurement distance increases. In some cases, the AGC value remains the same for two or more consecutive measurement ranges. In addition to the measured distance, AGC values may also vary based on transmitter / receiver probe, mounting method, propagation medium, and other factors.

  Prior to using the ultrasonic sensing system to provide an appropriate AGC value for a particular ultrasonic sensing system in a particular environment, test measurements are taken (such as the values illustrated in FIG. 5). The AGC value can be measured and / or calculated. During a test measurement, the echo signal for varying the measurement distance can be analyzed (eg, using an oscillator) to determine the amplitude of the echo signal. For example, the measurement distance can be gradually increased at fixed intervals (eg, 10 cm). Based on the amplitude of the received echo signal, the AGC value of the amplifier can be adjusted to cause the echo signal to exceed a trigger value (eg, a threshold that triggers a comparator). During actual proximity measurements, the AGC values derived from such test measurements provide a gain control signal to a gain-adjustable amplifier so that the controller of the ultrasonic sensing system can achieve the desired amount of gain. Can be used by Assuming that the change in measurement distance is proportional to the time elapsed from the start of propagation due to the constant sound propagation speed, the measurement distance shown in the table and graph of FIG. It can be converted to the amount of elapsed time. In some embodiments, a look-up table or similar data structure can be created and used for AGC values for a particular sensor and / or condition. Based on such a look-up table, a time-based gain control method can be provided to approximate the distance-based gain control illustrated in FIG.

  FIG. 6 is a flowchart illustrating the steps of a process 600 for implementing the time-based gain control described herein, according to one embodiment of the invention. In particular, process 600 can be used to provide dynamically adjusted gain control to a gain adjustable amplifier to compensate for variations in input signal attenuation. For example, the amount of gain can be adjusted (e.g., ramped up or kept the same) over time based on AGC data previously measured and / or calculated. In one embodiment, aspects of process 600 may be implemented by controller 412 shown in FIG.

  In one embodiment, the process 600 waits at step 602 for a predetermined interrupt. Such a predetermined interrupt may indicate, for example, the occurrence of a predetermined event that requires processing by an interrupt handler or interrupt handling routine (ISR). For example, such an interrupt may be triggered by a comparator when the input signal is greater than a predetermined trigger value. As another example, an interrupt may be triggered when the output of an analog-to-digital converter (ADC) reaches a predetermined threshold.

  At step 604, it is determined whether an interrupt has occurred. If so, the process 600 handles the interrupt at step 602, for example, by performing an ISR to calculate proximity to the object. If not, the process 600 returns to the waiting step 602.

  In one embodiment, the process 600 determines at step 606 whether a predetermined time increment Δt has elapsed. If so, at step 608, the AGC gain value is adjusted. If not, the process 600 returns to the waiting step 602. Therefore, the AGC gain value is adjusted at fixed time intervals. The time interval Δt may be set to any arbitrary time interval. Alternatively, the AGC value can be adjusted at various time intervals or in response to a given event. In some embodiments, the step of adjusting the AGC gain value comprises empirical AGC data as illustrated in FIG. 5 to determine an appropriate AGC value corresponding to the current measured distance or equivalently the current elapsed time. Or looking up those variations. For example, based on the current timer value, according to the table of FIG. 5, the current measured distance is in the range of 70-80 cm (based on the propagation speed of the ultrasonic signal), and the corresponding AGC value is 9 dB. Can be determined. Also, the AGC value is adjusted based on other factors, such as the output from at least one of a comparator or an analog to digital converter (ADC), various parameters associated with the ultrasound sensing system, and the like. It is also possible. Based on some or all of these factors, an appropriate control signal can be generated by the AGC value and provided to a gain-adjustable amplifier to achieve the desired amount of gain. In some embodiments, process 600 continues until the time period corresponding to the maximum measured distance has expired. Such a maximum measurement distance may be configurable.

  According to another aspect of the present invention, there is provided a method and system that uses an analog-to-digital converter (ADC) in conjunction with a comparator to improve the accuracy and precision of proximity measurements. For example, the ultrasound sensing system 400 of FIG. 4 includes a comparator 414 and an ADC 416, each connected to a gain adjustable amplifier 410. Comparator 414 can compare the input signal from gain-adjustable amplifier 410 with a predetermined trigger value (eg, voltage) and provide an indication whether the input signal is greater than the predetermined trigger value. For example, comparator 414 may output “1” if the input signal is greater than the trigger value, and output “0” otherwise. In some embodiments, the output of the comparator (eg, “1”) can trigger an interrupt as discussed in FIG. 6, causing the ISR to execute. ADC 416 can be configured to convert an analog signal to a digital signal representing the amplitude (eg, voltage) of the signal. In some cases, the output of the ADC can be used to trigger an interrupt. For example, such an interrupt can be triggered when the output of the ADC exceeds a predetermined threshold. In some embodiments, at least one of the comparator 414 or the ADC 416 can be part of or integrated with the controller 412, as illustrated in FIG. Alternatively, at least one of the comparator 414 or the ADC 416 can be external to the controller 412.

  In certain embodiments, the comparator 414 and the ADC 416 can be used together to improve the accuracy and accuracy of the measurement of the echo signal. In particular, comparator 414 can be used to trigger a proximity measurement, and measurements from ADC 416 can be used to determine when, within a predetermined time period, the relative peak amplitude has been received. This point can then be used to calculate the distance to the object that received the echo signal. By specifying the time of the peak amplitude, the accuracy of the proximity measurement is improved.

  Generally, the proximity to an object is calculated based on a time interval between transmission of an ultrasonic signal and reception of an ultrasonic signal reflected by the object. The transmission of the ultrasonic signal is generally at the time of transmission of the peak of the transmitted wave. When the reception time of the ultrasonic signal is set to the time at which the comparator is triggered by the reflected wave, when the comparator is triggered by the reflected wave (for example, less than the peak amplitude) and when the peak amplitude is reached It is difficult to say that the measurement is accurate because there is a period between them. It is relatively easy to detect the peak value and the peak value of the reflected wave by the ADC. The time at which the peak value was detected can then be used to calculate the distance to the object, thereby improving the accuracy of the measurement.

  FIG. 7 is a flowchart illustrating steps of a process 700 for determining the occurrence of a peak amplitude, according to one embodiment. Process 700 may be implemented, for example, by software, hardware, or a combination thereof embedded in controller 412 or elsewhere.

  In some embodiments, process 700 includes determining that the ADC is ready for measurement. In some cases, the ADC is activated for measurement after the comparator is triggered by the received signal. In addition, the ADC may make measurements only at certain time intervals. Such a time interval may be configurable by a manufacturer of the ADC, a user of the ADC (eg, a developer, an end user, etc.), or the like.

When the ADC is ready for measurement, at step 704 the ADC is used to obtain the current ADC value ADC _curr . The ADC value represents a digitized amplitude value of an input signal to the ADC. The current ADC value ADC _curr may be compared to a previously obtained ADC value ADC _old at step 706 to determine whether ADC _curr > ADC _old . In an exemplary embodiment, ADC _old is the ADC value in the last measurement. In some embodiments, the ADC _old is set to zero at the first ADC measurement (eg, at or after step 708) or at least one after each detection of peak amplitude.

If it is determined that the current ADC value is greater than the previously obtained ADC value, it may mean that the peak amplitude has not yet arrived. Thus, the process 700 proceeds to step 702 and begins the next phase of the measurement. However, if the previously acquired ADC value is equal to or greater than the current ADC value, it means that the peak has been reached. At step 708, the current timer value _tpeak is recorded. In some embodiments, the timer is started upon emission of the ultrasound signal. Thus, _tpeak represents the time interval between the transmission of the ultrasound signal and the reception of the peak of the ultrasound signal reflected by the object.

In some embodiments, the process 700 can be used to detect more than one object within the measurement range of the ultrasonic sensor. Thus, there can be more than one _tpeak , each associated with a different object. To realize the detection of multiple peak amplitude value, process 700, as long as the measurement time not ended, it may include the step of deriving the number of t _peak by repeating the process above. ADC _old may be reset to 0 before starting the measurement repeat. The measurement time generally refers to the time required to measure the maximum distance from the proximity sensing system that implements process 700. The measurement time can be determined by at least one of the characteristics of the proximity sensing system, the surrounding environment, or one configurable by the manufacturer, user, customer, or the like.

In some embodiments, the process 700 includes determining at step 710 whether the measurement time has expired. If the measurement time has expired, step 712 returns one or more _tpeak values. On the other hand, if the measurement time has not expired, the process 700 includes looping back to step 702 to begin another iteration to determine when a peak amplitude value has occurred.

  Referring back to FIG. 4, in some embodiments, at least one of the comparator 414 or the ADC 416 can be used to control at least one of the gain-adjustable amplifier 410 or the switch 406 discussed above. For example, at least one of AGC signal 418 or switch control signal 420 may be generated based on an output from at least one of comparator 414 or ADC 416.

  In some embodiments, controller 412 may include a microcontroller unit (MCU) on a single integrated circuit board. In certain other embodiments, controller 412 can include a distributed computing system. Controller 412 may include a processing unit 424, a memory 426, and input / output peripherals (not shown). Processing unit 424 may include one or more processors, such as a programmable processor (eg, a central processing unit (CPU)). The processing unit 424 can be operatively connected to the memory 426. The memory 426 may include one or more units of at least one of a temporary storage medium and a non-transitory storage medium. The storage medium stores at least one of data, logic, code, or program instructions executable by processing unit 424 to perform one or more routines or functions. For example, memory units include random access memory (RAM), read only memory (ROM), erasable programmable read only memory (PROM), electrically erasable programmable read only memory (EEPROM), and the like. Can be The memory units of the memory 426 may include input / output data, including data such as AGC values or variations thereof discussed in FIG. 5, data from comparators, ADCs, timers, sensors, or the like, processing units. Processing results from 424 and the like can be stored. In addition, a memory unit of memory 426 may include at least one of operating parameters or logic, at least code or program instructions executable by processing unit 424 to perform any suitable embodiments of the methods described herein. One can be memorized. For example, processing unit 424 may execute instructions that cause one or more processors of processing unit 424 to provide switch control signal 420 to switch 406 to achieve the time-based decay discussed in FIG. In addition, processing unit 424 may provide an amplifier 410 that can adjust the AGC control signal to one or more processors of processing unit 424 to achieve distance-based amplification of the received signal, as discussed with respect to FIG. Can be executed. Further, processing unit 424 can execute instructions that cause one or more processors of processing unit 424 to determine the occurrence of a peak amplitude (including timing) based on inputs from the comparator and the ADC as discussed above. . Although FIG. 4 illustrates a single processing unit 424 and a single memory 426, those skilled in the art will not limit this and that the system 400 may have multiple processing units or memory units of memory. It will be appreciated that at least one can be included.

In certain embodiments, controller 412 may also include a plurality of input / output peripherals (not shown). For example, the controller 412 can include one or more discrete input / output bits to enable control and / or detection of the logic state of individual package pins. Controller 412 may also include one or more serial inputs / outputs, such as a serial port (eg, a universal asynchronous receiver / transmitter (UART)). The controller 412 also, for the system ^{interconnect, Inter-Integrated Circuit (I 2} C), Serial Peripheral Interface (SPI) bus, controller area network (CAN) bus or the like as the likes, one or more serial A communication interface can also be included. In some cases, controller 412 may also include a timer, an event counter, a pulse width modulation (PWM) generator, a clock generator (eg, a quartz timing crystal, a resonator, or an oscillator for an RC circuit), and the like. And one or more peripherals. In some cases, the controller 412 may also include one or more digital-to-analog converters, in-circuit programming or debugging support, USB and Ethernet support, and the like.

  Although the methods and systems of the present invention are described in the context of an ultrasonic sensing system, aspects of the methods and systems of the present invention also provide a wide variety of proximity sensing using radar, sonar, lidar or other sensing techniques. Recognize that it can also be applied to systems.

  In certain embodiments, the methods and systems described herein can be used with movable objects, including proximity to target objects (eg, potential obstacles), locations of geographic features, locations of man-made structures, and Provide information about a movable object and / or the surrounding environment, such as the like. Such information is used by the movable object to sense at least one of spatial orientation, velocity, or acceleration of the movable object (eg, for up to three degrees of freedom in translation and up to three degrees of rotation). obtain. In addition, the information can assist in the movement of the movable object. This assistance includes, but is not limited to, path planning, autonomous navigation of movable objects along a given flight path, obstacle avoidance, and the like.

  A movable object (eg, a UAV) may include one or more sensors. The sensor may sense at least one of a spatial arrangement, a velocity, or an acceleration of the movable object (eg, for up to three degrees of translation and up to three degrees of rotation). The one or more sensors include a global positioning system (GPS) sensor, a behavior sensor, an inertial sensor, a proximity sensor (eg, at least one of an ultrasonic sensor and a lidar sensor), an image sensor, and the like. In some embodiments, the proximity sensor can rotate (eg, rotate 360 °) to obtain distance and position information of a plurality of objects surrounding the movable object. The distance and position information of the surrounding object can be analyzed to determine at least one of a spatial arrangement, movement of the movable object, or to assist in navigation of the movable object.

  The movable object may also include a controller for controlling the operation of the movable object or at least one of its components. The movable object can also be controlled remotely by the user or locally by an occupant in or on the movable object. In some embodiments, the movable object is an unmanned movable object, such as an unmanned aerial vehicle (UAV). An unmanned movable object such as a UAV may have no occupant boarding the movable object. The movable object can be controlled by a human or an autonomous control system (eg, a computer control system), or any suitable combination thereof. The movable object can be an autonomous or semi-autonomous robot, such as a robot configured with artificial intelligence.

  In certain embodiments, aspects of the methods and systems described herein can be implemented by a movable object, a remote control device, or a combination thereof. For example, the controller 412 of the proximity sensing system 400 may be implemented by a controller embedded in the movable object, which may also control the operation of the movable object, or a controller not embedded in the movable object, such as a remote control device or base station terminal. it can. For example, the control signal of at least one of the switch or the gain adjustable amplifier of FIG. 4 may be provided by a controller of at least one of a movable object or a remote control device. As another example, the proximity measurement and calculation may be performed by a controller of a movable object, a remote control device, a base station, or some third party device. In various embodiments, the controller of the proximity sensing system may be separate from or integrated with the controller of the movable object. In some embodiments, the same remote control device may be operable to control the movable object and the proximity sensing system. In other embodiments, separate remote control devices may be used to control the movable object and the proximity sensing system. In certain embodiments, the data provided by the proximity sensing system described herein provides for at least one of position, attitude, or other state information regarding the movable object and / or the environment surrounding the movable object. Can be used alone. Also, the data can be used in conjunction with data from other sensors or sensing systems that are or are not embedded in the movable object. The sensor or sensing system is, for example, a GPS sensor, a behavior sensor, an inertial sensor, a proximity sensor, an image sensor, and the like.

  A movable object in the present invention may be in air (eg, a fixed wing aircraft, a rotary wing aircraft, or an aircraft having neither fixed wings nor rotating wings), underwater (eg, a ship or submarine), and on the ground (eg, a vehicle). Vehicles such as trucks, buses, vans, motorcycles, bicycles, movable structures or frames such as canes, fishing rods, or trains), underground (eg, subways), in space (eg, space planes, satellites, or space probes) ) In any suitable environment, or any combination of these environments. The movable object can be placed on a living body such as a human or an animal. Suitable animals may include birds, canines, felines, equids, bovines, sheep, pigs, dolphins, rodents, or insects.

  The movable object may be freely movable in an environment with six degrees of freedom (eg, three degrees of freedom in translation and three degrees of rotation). On the other hand, the movement of the movable object may be restricted with respect to one or more degrees of freedom by a predetermined route, trajectory, position, or the like. Movement can be achieved by any suitable actuation mechanism, such as an engine or a motor. The actuation mechanism of the movable object may be powered by any suitable energy source, such as electrical energy, magnetic energy, solar energy, wind energy, gravitational energy, chemical energy, nuclear energy, or any suitable combination thereof.

  In some cases, the movable object may be a manned or unmanned transport. Suitable transports may include water transports, aircraft, spacecraft, or ground vehicles. For example, the aircraft may be a fixed wing aircraft (eg, an airplane, a glider), a rotorcraft (eg, a helicopter, a rotorcraft), an aircraft having both fixed wings and a rotorcraft, or an aircraft having neither. Airship, hot air balloon). The aircraft may be self-propelled, such as self-propelled in the air. A self-propelled vehicle can utilize a propulsion system, such as a propulsion system that includes one or more engines, motors, wheels, axles, magnets, rotors, propellers, vanes, nozzles, or any suitable combination thereof. Also, the propulsion system can be used to allow the movable object to take off from the surface, land on the surface, maintain at least one of its current position or orientation (eg, hover), change at least one of the orientation or position. .

  For example, a propulsion system may include one or more rotors. The rotor may include one or more blades (eg, one, two, three, four, or more blades) mounted on a central shaft. The vanes can be arranged symmetrically or asymmetrically about a central shaft. The blades can be rotated by rotation of a central shaft and can be driven by a suitable motor or engine. The blade may rotate at least one of clockwise rotation or counterclockwise rotation. The rotor may be a horizontal rotor (which may refer to a rotor having a horizontal plane of rotation), a vertically oriented rotor (which may refer to a rotor having a vertical plane of rotation), or a combination of horizontal and vertical positions. The rotor may be inclined at an intermediate angle between them. In certain embodiments, a horizontally oriented rotor may rotate to provide lift to a movable object. The vertically oriented rotor may rotate to provide propulsion to the movable object. Rotors that are oriented at an intermediate angle between the horizontal and vertical positions may rotate to provide both lift and propulsion to a movable object. One or more rotors may be used to provide torque that counteracts the torque generated by the rotation of another rotor.

  The movable object may have any suitable size and / or dimensions. In certain embodiments, the movable object can have at least one of a size or dimensions for providing a human occupant within or on the transport. Also, the movable object may be at least one of a size or a dimension smaller than at least one of a size or a dimension capable of providing a human occupant inside or on the movable object. The movable object may be at least one of a size or a dimension suitable for being lifted or supported by a human. Also, the movable object may be larger than at least one of a size or dimensions suitable for being lifted or supported by a human. In some embodiments, the movable object has a maximum dimension (eg, length, width, height, diameter, etc.) of about 2 cm or less, 5 cm or less, 10 cm or less, 50 cm or less, 1 m or less, 2 m or less, 5 m or less, or 10 m or less. , Diagonal). The largest dimension of the movable object can be about 2 cm or more, 5 cm or more, 10 cm or more, 50 cm or more, 1 m or more, 2 m or more, 5 m or more, or 10 m or more. For example, the distance between the axes of the opposing rotors of the movable object may be about 2 cm or less, 5 cm or less, 10 cm or less, 50 cm or less, 1 m or less, 2 m or less, 5 m or less, or 10 m or less. Alternatively, the distance between the axes of the opposing rotor blades may be about 2 cm or more, 5 cm or more, 10 cm or more, 50 cm or more, 1 m or more, 2 m or more, 5 m or more, or 10 m or more.

In certain embodiments, the movable object can have a volume of less than 100 cm × 100 cm × 100 cm, less than 50 cm × 50 cm × 30 cm, or less than 5 cm × 5 cm × 3 cm. The total volume of the movable object is about 1 cm ³ or less, 2 cm ³ or less, 5 cm ³ or less, 10 cm ³ or less, 20 cm ³ or less, 30 cm ³ or less, 40 cm ³ or less, 50 cm ³ or less, 60cm ³ below, 70cm ³ below, 80 cm ³ below, 90cm ³ below, 100cm ³ below, 150cm ³ below, 200cm ³ below, 300cm ³ below, 500cm ³ below, 750cm ³ below, 1000cm ³ below, 5000cm ³ below, 10,000cm ³ below, 100,000cm ³ below, 1 m ³ or less, or may be 10 m ³ or less. Conversely, the total volume of the movable object is about 1 cm ³ or more, 2 cm ³ or more, 5 cm ³ or more, 10 cm ³ or more, 20 cm ³ or more, 30 cm ³ or more, 40 cm ³ or more, 50 cm ³ or more, 60 cm ³ or more, 70 cm ³ or more , 80cm ³ or more, 90cm ³ or more, 100cm ³ or more, 150cm ³ or more, 200cm ³ or more, 300cm ³ or more, 500cm ³ or more, 750cm ³ or more, 1000cm ³ or more, 5000cm ³ or more, 10,000cm ³ or more, 100,000cm ^{It can be 3} or more, 1 m ³ or more, or 10 m ³ or more.

In certain embodiments, the movable object, 32,000Cm ² or less, 20,000 cm ² or less, 10,000 cm ² or less, 1,000 cm ² or less, 500 cm ² or less, 100 cm ² or less, 50 cm ² or less, 10 cm ² or less, or It may have a footprint (or lateral cross-sectional area surrounded by a movable object) of 5 cm ² or less. Conversely, footprint about 32,000Cm ² or more, 20,000 cm ² or more, 10,000 cm ² or more, 1,000 cm ² or more, 500 cm ² or more, 100 cm ² or more, 50 cm ² or more, 10 cm ² or more, or 5 cm ² Or more.

  In some embodiments, the weight of the movable object can be 1000 kg or less. The weight of the movable object is about 1000 kg or less, 750 kg or less, 500 kg or less, 200 kg or less, 150 kg or less, 100 kg or less, 80 kg or less, 70 kg or less, 60 kg or less, 50 kg or less, 45 kg or less, 40 kg or less, 35 kg or less, 30 kg or less, 25 kg 20 kg or less, 12 kg or less, 10 kg or less, 9 kg or less, 8 kg or less, 7 kg or less, 6 kg or less, 5 kg or less, 4 kg or less, 3 kg or less, 2 kg or less, 1 kg or less, 0.5 kg or less, 0.1 kg or less, 0.1 kg or less. It can be up to 05 kg, or up to 0.01 kg. Conversely, the weight of the movable object is about 1000 kg or more, 750 kg or more, 500 kg or more, 200 kg or more, 150 kg or more, 100 kg or more, 80 kg or more, 70 kg or more, 60 kg or more, 50 kg or more, 45 kg or more, 40 kg or more, 35 kg or more, 30 kg or more , 25 kg or more, 20 kg or more, 12 kg or more, 10 kg or more, 9 kg or more, 8 kg or more, 7 kg or more, 6 kg or more, 5 kg or more, 4 kg or more, 3 kg or more, 2 kg or more, 1 kg or more, 0.5 kg or more, 0.1 kg or more, It may be 0.05 kg or more, or 0.01 kg or more.

  In some embodiments, the movable object may be smaller than the load supported by the movable object. The load may include at least one of a load or a support mechanism, as described in further detail below. In some embodiments, the ratio of the weight of the movable object to the weight of the load may be greater than, less than, or equal to about 1: 1. Also, in other embodiments, the ratio of the weight of the movable object to the weight of the load may be greater than, less than, or equal to about 1: 1. Also, the ratio of support mechanism weight to payload weight may be greater than, less than, or equal to about 1: 1. If required, the ratio of the movable object weight to the load weight may be less than or equal to 1: 2, 1: 3, 1: 4, 1: 5, 1:10 or even less. Conversely, the ratio of the weight of the movable object to the weight of the load may be greater than 2: 1, 3: 1, 4: 1, 5: 1, 10: 1 or even greater.

  In some embodiments, the energy consumption of the movable object may be low. For example, a movable object may use about 5 W / hr, 4 W / hr, 3 W / hr, 2 W / hr, less than 1 W / hr, or less. In other embodiments, the energy consumption of the support mechanism for the movable object may be low. For example, the support mechanism may use about 5 W / hr, 4 W / hr, 3 W / hr, 2 W / hr, less than 1 W / hr, or less. Also, the energy consumption of the load of the movable object can be as low as about 5 W / hour, 4 W / hour, 3 W / hour, 2 W / hour, less than 1 W / hour, or less.

While preferred embodiments of the invention have been illustrated and described herein, it will be obvious to those skilled in the art that such embodiments are for purposes of illustration only. Many variations, modifications, and alternatives will occur to those skilled in the art without departing from the invention. It is to be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. The following claims are intended to define the scope of the invention, thereby covering the claimed methods and structures, as well as their equivalents.
[Item 1]
In an ultrasonic sensing system,
An ultrasonic transmitter for transmitting an ultrasonic signal,
As a result of the transmission, an ultrasonic receiver that receives an ultrasonic signal including a reverberation signal and an echo signal,
An attenuator circuit connected to the ultrasonic receiver via a switch, and an attenuator circuit for attenuating the received ultrasonic signal,
A microcontroller unit (MCU) that controls the switch to electrically connect the ultrasonic receiver to the attenuator circuit during a predetermined period after the transmission of the ultrasonic signal;
Comprising,
Ultrasonic sensing system.
[Item 2]
The ultrasonic transmitter is the ultrasonic receiver,
Item 2. The ultrasonic sensing system according to Item 1.
[Item 3]
The predetermined period corresponds to a dead zone period of the ultrasonic sensing system,
Item 2. The ultrasonic sensing system according to Item 1.
[Item 4]
The attenuator circuit is selected based at least in part on a previously measured amplitude of the reverberant or echo signal;
Item 2. The ultrasonic sensing system according to Item 1.
[Item 5]
Further comprising a booster for increasing an energy level associated with the transmission of the ultrasonic signal,
Item 2. The ultrasonic sensing system according to Item 1.
[Item 6]
Further comprising a gain-adjustable amplifier for amplifying the echo signal,
Item 2. The ultrasonic sensing system according to Item 1.
[Item 7]
The MCU further controls the gain-adjustable amplifier to vary its gain based at least in part on a timer value corresponding to the measured distance.
Item 7. The ultrasonic sensing system according to Item 6.
[Item 8]
The MCU further controls the gain adjustable amplifier to vary its gain based at least in part on previously measured data.
Item 8. The ultrasonic sensing system according to Item 7.
[Item 9]
The MCU further controls the switch so that after the predetermined period has elapsed, the attenuator circuit is not electrically connected to the gain-adjustable amplifier, and the ultrasonic receiver is adjusted for the gain. Electrically connect with possible amplifiers,
Item 7. The ultrasonic sensing system according to Item 6.
[Item 10]
A comparator connected to the gain-adjustable amplifier and comparing an output of the gain-adjustable amplifier to a predetermined threshold value;
Item 7. The ultrasonic sensing system according to Item 6.
[Item 11]
The comparator is integrated with the MCU;
Item 11. The ultrasonic sensing system according to Item 10.
[Item 12]
An analog-to-digital converter (ADC) connected to the gain-adjustable amplifier and converting the output of the gain-adjustable amplifier to a digital value;
Item 11. The ultrasonic sensing system according to Item 10.
[Item 13]
The comparator and the ADC are used together to determine the occurrence of a peak amplitude of the received ultrasound signal;
Item 13. The ultrasonic sensing system according to Item 12.
[Item 14]
In the method of sensing ultrasonic waves,
Detecting the signal after the end of the transmission of the ultrasound signal, wherein the detected signal may be an echo signal or a reverberation signal,
Determining whether the detection of the ultrasonic signal has occurred within a predetermined period from the end of the transmission of the ultrasonic signal,
Responsive to the determination that the detection of the signal has occurred within the predetermined time period, attenuating the detected signal to sufficiently reduce interference caused by reverberation from the transmission of the ultrasonic signal. Steps and
Processing the detected signal without attenuating, in order to determine the proximity of an object, in response to the determination that the detection of the signal has occurred after the predetermined period has elapsed;
Including, methods.
[Item 15]
Item 15. The method according to Item 14, wherein the predetermined period corresponds to a dead zone period.
[Item 16]
15. The method of claim 14, wherein attenuating the detected ultrasound signal is based at least in part on one or more previously measured signals.
[Item 17]
15. The method of claim 14, wherein processing the detected ultrasound signal comprises using a comparator and an analog-to-digital converter (ADC) to determine the occurrence of a peak amplitude.
[Item 18]
15. The method of item 14, further comprising providing a gain to the detected ultrasound signal based at least in part on a measured distance and data previously measured that correlates an appropriate gain to the measured distance. .
[Item 19]
15. The method of claim 14, further comprising providing a gain to the detected ultrasound signal based at least in part on a timer value.
[Item 20]
In the method of sensing ultrasonic waves,
After the transmission of the ultrasonic signal is completed, the step of detecting an ultrasonic signal, wherein the detected ultrasonic signal is an echo signal or a reverberation signal, a detecting step,
Attenuating the detected ultrasonic signal without substantially eliminating the reverberation signal without excluding the echo signal;
Including, methods.
[Item 21]
21. The method according to item 20, wherein the attenuation of the detected ultrasonic signal is applied only within a predetermined period from the transmission of the ultrasonic signal.
[Item 22]
21. The method of item 20, wherein attenuating the detected ultrasound signal is based at least in part on a previously measured amplitude of the reverberant or echo signal.
[Item 23]
21. The method of item 20, further comprising determining the occurrence of a peak amplitude using a comparator and an analog-to-digital converter (ADC).
[Item 24]
21. The method of item 20, further comprising providing a gain to the detected ultrasound signal based at least in part on previously measured data.
[Item 25]
In the method of sensing ultrasonic waves,
Adjusting the amplifier to provide a first gain to the received ultrasound signal based at least in part on previously measured adjustable gain control (AGC) data;
Adjusting the amplifier at a later point in time to provide a second gain that is greater than the first gain based at least in part on the previously measured AGC data;
Including, methods.
[Item 26]
26. The method of claim 25, wherein the previously measured data correlates a measured distance and an appropriate gain to the measured distance.
[Item 27]
26. The method of claim 25, further comprising adjusting the amplifier to provide increasing gain over time until an echo signal is detected or a predetermined measurement time is reached.
[Item 28]
26. The method according to item 25, wherein the received ultrasonic signal is attenuated before being amplified only when the ultrasonic signal is received during a predetermined time period.
[Item 29]
29. The method according to item 28, wherein during the predetermined period, the received ultrasonic signal is attenuated so as not to reject echo signals and to reject substantially all reverberation signals.
[Item 30]
The method of claim 25, further comprising determining the occurrence of a peak amplitude using a comparator and an analog-to-digital converter (ADC).

Claims (20)

In an ultrasonic sensing system,
An ultrasonic transmitter for transmitting an ultrasonic signal,
As a result of the transmission, an ultrasonic receiver that receives an ultrasonic signal including a reverberation signal and an echo signal,
An attenuator circuit connected to the ultrasonic receiver via a switch, wherein the attenuator circuit attenuates the received ultrasonic signal,
Controlling the switch to electrically connect the ultrasonic receiver to the attenuator circuit during a predetermined period after the transmission of the ultrasonic signal, and to perform the ultrasonic reception before and after the predetermined period; A microcontroller unit (MCU) for electrically disconnecting the machine from the attenuator circuit;
During the predetermined period, the gain can be adjusted to amplify the ultrasonic signal attenuated by the attenuator circuit, and after the predetermined period elapse, amplify the ultrasonic signal that has not been attenuated by the attenuator circuit. Amplifier and
A comparator coupled to the gain-adjustable amplifier for comparing the output of the gain-adjustable amplifier to a predetermined threshold and triggering a proximity measurement if the output of the gain-adjustable amplifier is greater than the predetermined threshold; When,
An analog-to-digital converter (ADC) connected to the gain-adjustable amplifier and converting the output of the gain-adjustable amplifier to a digital value ;
The ADC is activated for the proximity measurement when the proximity measurement is triggered by the comparator, and calculates the peak amplitude of the ultrasonic signal used for calculating the distance to the object reflecting the echo signal. Identify when received,
Ultrasonic sensing system. The ultrasonic transmitter is the ultrasonic receiver,
The ultrasonic sensing system according to claim 1. The predetermined period corresponds to a dead zone period of the ultrasonic sensing system.
The ultrasonic sensing system according to claim 1. The attenuator circuit provides a selected amount of attenuation based at least in part on a previously measured amplitude of the reverberant or echo signal;
An ultrasonic sensing system according to any one of claims 1 to 3. Further comprising a booster connected to the ultrasonic transmitter to increase an energy level associated with the transmission of the ultrasonic signal.
An ultrasonic sensing system according to any one of claims 1 to 4. The MCU further controls the gain-adjustable amplifier to vary its gain based at least in part on a timer value corresponding to the measured distance.
An ultrasonic sensing system according to any one of claims 1 to 5 . The MCU further controls the gain adjustable amplifier to vary its gain based at least in part on previously measured data.
An ultrasonic sensing system according to claim 6 . The MCU further controls the switch so that the attenuator circuit is not electrically connected to the gain-adjustable amplifier after the predetermined period has elapsed, and the ultrasonic receiver performs the gain adjustment. Electrically connect with possible amplifiers,
An ultrasonic sensing system according to any one of the preceding claims. The comparator is integrated with the MCU;
An ultrasonic sensing system according to any one of the preceding claims. In the method of sensing ultrasonic waves,
Detecting, at the ultrasonic receiver, a signal after the end of transmission of the ultrasonic signal, wherein the detected signal may be an echo signal or a reverberation signal, and detecting, Determining whether detection has occurred within a predetermined time period from the end of the transmission of the ultrasonic signal;
An attenuator circuit, responsive to the determination that the detection of the signal has occurred within the predetermined time period, to sufficiently reduce interference caused by reverberation from the transmission of the ultrasonic signal. After the signal is attenuated , the detected signal is input to an amplifier connected to the ultrasonic receiver, and after the predetermined period has elapsed, the ultrasonic receiver is electrically connected to the ultrasonic receiver from the attenuator circuit. connection is released, in response to determination that the detection has occurred in the signal after the predetermined period of time, to determine the proximity of an object, entering not attenuate, the detected signal to the amplifier Steps and
Comparing the output of the amplifier to a predetermined threshold with a comparator connected to the amplifier, and triggering a proximity measurement if the output of the amplifier is greater than the predetermined threshold;
When the proximity measurement is triggered by the comparator, an analog-to-digital converter (ADC) connected to the amplifier and converting the output of the amplifier to a digital value is activated for the proximity measurement; Determining when to receive the peak amplitude of the ultrasound signal used to calculate the distance to the object reflecting the echo signal . The method of claim 10 , wherein the predetermined time period corresponds to a dead zone period. The method according to claim 10 or 11 , wherein the step of attenuating the detected ultrasound signal is based at least in part on one or more previously measured signals. Measured distance and based at least in part on the measured data before correlating the appropriate gain to the measurement distance, further comprising the step of providing a gain to the detected ultrasound signals, from 10. 12 A method according to any one of the preceding claims. 14. The method of any one of claims 10 to 13 , further comprising providing a gain to the detected ultrasound signal based at least in part on a timer value. In an ultrasonic sensing system,
An ultrasonic transmitter for transmitting an ultrasonic signal,
As a result of the transmission, an ultrasonic receiver that receives an ultrasonic signal including a reverberation signal and an echo signal,
An attenuator circuit connected to the ultrasonic receiver via a switch, wherein the attenuator circuit attenuates the received ultrasonic signal,
A microcontroller unit (MCU) that controls the switch to electrically connect the ultrasonic receiver with the attenuator circuit only during a predetermined period after the transmission of the ultrasonic signal;
During the predetermined period, the gain can be adjusted to amplify the ultrasonic signal attenuated by the attenuator circuit, and after the predetermined period elapse, amplify the ultrasonic signal that has not been attenuated by the attenuator circuit. Amplifier and
Comparative connected to said gain adjustable amplifier compares the output of said gain adjustable amplifier with a predetermined threshold value, the output of said gain adjustable amplifier triggers a proximity measurement is greater than the predetermined threshold Vessels,
An analog-to-digital converter (ADC) connected to the gain-adjustable amplifier and converting the output of the gain-adjustable amplifier to a digital value ;
The ADC is activated for the proximity measurement when the proximity measurement is triggered by the comparator, and calculates the peak amplitude of the ultrasonic signal used for calculating the distance to the object reflecting the echo signal. An ultrasonic sensing system that identifies when it was received . The ultrasonic transmitter is the ultrasonic receiver,
An ultrasonic sensing system according to claim 15 . The predetermined period corresponds to a dead zone period of the ultrasonic sensing system.
An ultrasonic sensing system according to claim 15 or 16 . The attenuator circuit provides a selected amount of attenuation based at least in part on a previously measured amplitude of the reverberant or echo signal;
An ultrasonic sensing system according to any one of claims 15 to 17 . In the method of sensing ultrasonic waves,
Detecting , at the ultrasonic receiver, a signal after the transmission of the ultrasonic signal is completed, wherein the detected signal may be an echo signal or a reverberation signal;
Amplifying the detected signal with an amplifier connected to the ultrasonic receiver,
Determining whether the detection of the ultrasonic signal has occurred within a predetermined period from the end of the transmission of the ultrasonic signal,
In response to determining that the detection of the signal has occurred within the predetermined time period, attenuating the detected signal to sufficiently reduce interference caused by reverberation from the transmission of the ultrasonic signal. After that, input the detected signal to the amplifier, in response to the determination that the detection of the signal has occurred after the predetermined period has elapsed, to determine the proximity of the object, without attenuation, Inputting the detected signal to the amplifier ;
Comparing the output of the amplifier to a predetermined threshold with a comparator connected to the amplifier, and triggering a proximity measurement if the output of the amplifier is greater than the predetermined threshold;
When the proximity measurement is triggered by the comparator, an analog-to-digital converter (ADC) connected to the amplifier and converting the output of the amplifier to a digital value is activated for the proximity measurement; Determining a point in time at which a peak amplitude of the ultrasound signal used to calculate a distance to the object reflecting the echo signal is received . 20. The method of claim 19 , wherein attenuating the detected ultrasound signal is based at least in part on one or more previously measured signals.