JP4682802B2 - Sensor device and self-propelled robot using the same - Google Patents

Description

  The present invention relates to a sensor device used for detecting a distance to an object, an azimuth in which the object exists, and a self-running robot using the sensor device.

  Conventionally, as this type of sensor device, for example, a sparse wave is intermittently transmitted into the air from a wave transmission device having a transmission element capable of transmitting a sparse wave such as an ultrasonic wave and reflected by an object. There is known a sensor device that detects a distance to an object and an azimuth in which the object exists based on a time difference until a dense wave is received by a wave receiving element (see, for example, Patent Document 1). Note that this type of sensor device is used as an obstacle detection device that detects obstacles in the field of a self-propelled robot that moves while avoiding obstacles, for example, for applications such as detection of obstacles and human bodies. Has been.

  In the sensor device disclosed in Patent Document 1, a receiving device that receives a dense wave transmitted from a transmitting device and reflected by an object has a plurality of receiving devices arranged on one plane. Therefore, it is possible to detect an object existing in a desired direction by using the relation between the arrival direction of the dense wave (the direction in which the object exists) and the time difference between the arrival times of the dense wave in adjacent receiving elements. It is configured as follows.

  That is, the sensor device disclosed in Patent Document 1 combines a received signal obtained by delaying the received signal of each receiving element by a delay time corresponding to the arrangement pattern (arrangement position) of each receiving element. The output of the delay means, the adder for adding the set of received signals delayed by the delay means, and the peak value exceeding the threshold by comparing the magnitude relationship between the peak value of the output waveform of the adder and an appropriate threshold And determining means for determining that the direction corresponding to the combination of the delay times set by the delay means is the direction in which the object exists (the arrival direction of the dense wave). In short, when the peak value of the output waveform of the adder exceeds the threshold value, in other words, when the timings of all the received signals delayed by the delay unit overlap (when the times of the received signals match) The direction corresponding to the combination of the delay times is set as the arrival direction of the dense wave with respect to the receiving device (the direction in which the object exists).

In the sensor device, piezoelectric elements are widely used for the transmitting elements and the receiving elements.
JP 2002-156451 A

  However, the sensor device described in Patent Document 1 performs complicated signal processing in which the received signal of each receiving element is added with a delay time corresponding to the arrangement pattern of each receiving element. Therefore, since the distance to the object and the azimuth in which the object exists are obtained, a plurality of receiving elements are required, the signal processing circuit is complicated, and the configuration of the entire sensor device is complicated. Further, in the sensor device having one transmitting element and one receiving element, the directivity of the transmitting element is determined by the specifications of the sensor apparatus. Therefore, in order to adjust the detection area of the sensor apparatus In addition, it is necessary to provide a radiation range adjusting member for adjusting the radiation range of the dense wave from the transmission element and to provide a movable mechanism for changing the direction of the transmission element.

  The present invention has been made in view of the above reasons, and its purpose is to provide a sensor device capable of adjusting the detection area with a simpler configuration than before and an obstacle detection area with a simpler configuration than conventional. It is to provide an adjustable self-propelled robot.

The inventions of claims 1 and 2 are a transmission element that transmits a sparse / dense wave, a sparse wave that is transmitted from the transmission element and reflected by an object, and the received sparse / dense wave is an electrical signal. And a signal processing unit for detecting an object using the received wave signal output from the wave receiving element, and the wave transmitting element has a temperature of the heat generating part due to energization of the heat generating part. It consists of a sound wave generating element that generates a dense wave by giving a thermal shock to the air by change, and the pulse width of the drive input waveform energized to the heat generating part of the transmitting element is variable, and the wave is transmitted by controlling the pulse width It has a transmission control unit capable of controlling the directivity of the dense wave generated from the element.

  According to this invention, the wave transmitting element is composed of a sound wave generating element that generates a sparse wave by applying a thermal shock to the air due to a temperature change of the heat generating part accompanying energization of the heat generating part, and energizes the heat generating part of the wave transmitting element. Since the pulse width of the drive input waveform is variable and has a transmission control unit capable of controlling the directivity of the dense wave generated from the transmission element by controlling the pulse width, the radiation range adjustment member is used. Control of transmission without adjusting the radiation range of the dense wave by adjusting the radiation range of the dense wave or providing a movable mechanism that adjusts the direction of the transmission element and adjusting the direction of the transmission element by the movable mechanism By controlling the pulse width of the drive input waveform energized from the heating part to the heating element of the wave transmitting element, the directivity of the dense wave generated from the wave transmitting element can be changed and the detection area can be adjusted. Detection area with simple configuration It becomes adjustable. In addition, if a switch for instructing to change the pulse width of the drive input waveform is provided, the detection area can be easily adjusted or changed on the spot according to the surrounding conditions at each installation location and the purpose of the user. It becomes possible.

The invention of claim 1 and 2, feed wave control unit causes directional from the waves element feed has successively changing the pulse width of the drive input waveform as a plurality of types of compressional waves respectively different are sequentially transmitting, signal processing unit, and detects the object by using the output of the wave receiving element at each wave receiving period defined in accordance with the respective energization timing of each pulse width each drive input waveform.

According to the present invention, feeding wave control unit causes directivity from the waves element feed has successively changing the pulse width of the drive input waveform as a plurality of types of compressional waves different each is sequentially transmit, the signal processing unit , and detects the object by using the output of the put that received wave element in each wave receiving period defined in accordance with the respective energization timing of each pulse width each drive input waveform, to be capable of setting a plurality of detection areas Become. Moreover, whereas the ultrasonic wave generating device using a conventional piezoelectric element to enhance the sound pressure can radiate compression wave of a continuous wave or a plurality of cycles, with feed wave element, the occurrence period and short sound pressure Can generate a high density of sparse and dense waves, so that the interval between the energization timings of the drive input waveform can be shortened, and each of the sparse and dense waves that are sequentially transmitted from the transmission element and have different directivities and reflected by the object Can be received separately by the receiving element at relatively short time intervals to obtain independent received signals, so that the time resolution can be increased.

Further, in the invention of claim 1, signal processing unit corresponding to the output and the pulse width of the put that received wave element in each wave receiving period defined in accordance with the respective energization timing of each pulse width each drive input waveform It is characterized by comprising area estimation means for estimating the area where an object exists based on the relationship with directivity.

  According to the present invention, an area where an object exists can be estimated.

Further, in the invention of claim 2, signal processing unit corresponds to the output and the pulse width of the wave receiving devices of each wave receiving period defined in accordance with the respective energization timing of each pulse width each drive input waveform It is characterized by comprising azimuth estimating means for estimating the azimuth in which an object exists based on the relationship with directivity.

  According to the present invention, the azimuth in which an object exists can be estimated.

According to a third aspect of the present invention, a plurality of sensor units comprising the sensor device according to the second aspect are arranged on the same plane, and a dense wave transmitted from a wave transmitting element of another sensor unit and reflected by an object is received. It is characterized by comprising a shielding plate that prevents the light from entering the element.

  According to the present invention, it is possible to more accurately estimate the azimuth in which an object exists.

According to a fourth aspect of the present invention, there is provided a robot main body, traveling means for allowing the robot main body to move, an obstacle detection device mounted on the robot main body for detecting an obstacle, and avoiding an obstacle detected by the obstacle detection device. And a travel control means for controlling the travel means so that the robot body moves, and the sensor device according to any one of claims 1 to 3 is used as an obstacle detection device. And

  According to the present invention, it becomes possible to adjust the detection area of the obstacle detection device in the self-running robot with a simple configuration as compared with the conventional one, the degree of freedom of the attachment position of the obstacle detection device with respect to the robot body is increased, and the installation work And the load on a self-propelled robot equipped with a complicated control system and drive system can be reduced.

According to the first and second aspects of the present invention, the directivity of the dense wave generated from the transmission element can be changed by controlling the pulse width of the drive input waveform energized from the transmission control unit to the heat generating part of the transmission element. In addition, since the detection area can be adjusted, there is an effect that the detection area can be adjusted with a simpler configuration than in the past.

In the invention of claim 4 , there is an effect that the detection area of the obstacle detection device in the self-propelled robot can be adjusted with a simpler configuration than in the prior art.

(Reference example)
As shown in FIG. 1, the sensor device of this reference example includes a transmission element 10 that transmits a sparse / dense wave, a transmission control unit 20 that controls the transmission element 10, and an object transmitted from the transmission element 10. A wave receiving element 30 that receives the density wave reflected by Ob and converts the received density wave into a received wave signal that is an electric signal, and a received signal output from the wave receiving element 30 is used to detect the object Ob. And a signal processing unit 50 for detecting.

In this reference example, a sound wave generating element that generates a dense wave by applying a thermal shock to air as will be described later is used as the wave transmitting element 10, so that the Q value of the resonance characteristics of the wave transmitting element 10 is expressed as a piezoelectric element. The reverberation component included in the received signal is such that the density of the resonance characteristic of the receiving element 30 is sufficiently smaller than that of the piezoelectric element. A capacitance type microphone with a short generation period is used.

  Here, as shown in FIG. 2, the wave transmitting element 10 includes a heat insulating layer (including a porous silicon layer) on one surface (upper surface in FIG. 2) of a base substrate 11 made of a single crystal p-type silicon substrate. A heat insulating layer) 12 is formed, and a heat generating layer 13 made of a metal thin film is formed on the surface side of the heat insulating layer 12 as a heat generating portion, and is electrically connected to the heat generating layer 13 on the one surface side of the base substrate 11. A pair of pads 14 and 14 are formed. The planar shape of the base substrate 11 is a rectangular shape, and the planar shapes of the heat insulating layer 12 and the heating element layer 13 are also formed in a rectangular shape.

  In the above-described transmission element 10, when a sudden temperature change is caused in the heating element layer 13 by energizing the pads 14 and 14 at both ends of the heating element layer 13, the air (medium that is in contact with the heating element layer 13) ) Abruptly changes in temperature (thermal shock) (that is, thermal shock is applied to the air in contact with the heating element layer 13). Accordingly, the air in contact with the heating element layer 13 expands when the temperature of the heating element layer 13 rises and contracts when the temperature of the heating element layer 13 decreases. Therefore, by appropriately controlling energization to the heating element layer 13 Density waves propagating in the air can be generated. In short, the sound wave generating element constituting the wave transmitting element 10 generates a sparse wave propagating through the medium by converting a rapid temperature change of the heating element layer 13 accompanying energization to the heating element layer 13 into expansion and contraction of the medium. Therefore, the reverberation time can be reduced as compared with the case where a dense wave is generated by mechanical vibration like a piezoelectric element (in other words, the reverberation component in the dense wave transmitted from the wave transmitting element 10 can be reduced). In addition, the reverberation time is about 0.5 ms in the dense wave transmitted from the wave transmitting element using the piezoelectric element, whereas the dense wave transmitted from the wave transmitting element 10 including the above-described sound wave generating element. Can suppress the reverberation time to about 0.05 ms.

In the above-described transmission element 10, a p-type silicon substrate is used as the base substrate 11, and the heat insulating layer 12 is composed of a porous silicon layer having a porosity of about 60 to about 70%. A porous silicon layer serving as the thermal insulating layer 12 can be formed by anodizing a part of the silicon substrate used as 11 in an electrolytic solution made of a mixed solution of hydrogen fluoride aqueous solution and ethanol (here, The porous silicon layer formed by the anodization treatment contains a large number of nanocrystalline silicon composed of microcrystalline silicon having a crystal grain size on the order of nanometers). Since the porous silicon layer has a lower thermal conductivity and heat capacity as the porosity becomes higher, the thermal conductivity and heat capacity of the heat insulating layer 12 are made smaller than the heat conductivity and heat capacity of the base substrate 11, and heat insulation is performed. By making the product of the thermal conductivity and the thermal capacity of the layer 12 sufficiently smaller than the product of the thermal conductivity and the thermal capacity of the base substrate 11, the temperature change of the heating element layer 13 can be efficiently transmitted to the air. The heat generating body layer 13 and the air can efficiently exchange heat, and the base substrate 11 can efficiently receive the heat from the heat insulating layer 12 and release the heat of the heat insulating layer 12 to generate heat. It is possible to prevent heat from the body layer 13 from being accumulated in the heat insulating layer 12. Note that the porosity formed by anodizing a single crystal silicon substrate having a thermal conductivity of 148 W / (m · K) and a heat capacity of 1.63 × 10 ⁶ J / (m ³ · K) is 60%. The porous silicon layer is known to have a thermal conductivity of 1 W / (m · K) and a heat capacity of 0.7 × 10 ⁶ J / (m ³ · K). In this reference example, the heat insulating layer 12 is composed of a porous silicon layer having a porosity of approximately 70%, the heat conductivity of the heat insulating layer 12 is 0.12 W / (m · K), and the heat capacity is 0. .5 × 10 ⁶ J / (m ³ · K).

  The heating element layer 13 is formed of tungsten, which is a kind of refractory metal, but the material of the heating element layer 13 is not limited to tungsten, and for example, tantalum, molybdenum, iridium, aluminum, or the like may be employed. Further, in the above-described transmission element 10, the thickness of the base substrate 11 is 300 to 700 μm, the thickness of the thermal insulating layer 12 is 1 to 10 μm, the thickness of the heating element layer 13 is 20 to 100 nm, and the thickness of each pad 14. Although the thickness is 0.5 μm, these thicknesses are merely examples and are not particularly limited. Further, Si is adopted as the material of the base substrate 11, but the material of the base substrate 11 is not limited to Si, and, for example, it can be made porous by anodizing treatment such as Ge, SiC, GaP, GaAs, InP or the like. Other semiconductor materials may be used.

  As described above, the wave transmitting element 10 generates a dense wave in accordance with a temperature change of the heating element layer 13 due to energization of the heating element layer 13 via the pair of pads 14 and 14. When the drive input waveform formed from the drive voltage waveform or the drive current waveform applied to 13 is a sine wave waveform having a frequency of f1, for example, the frequency of the temperature oscillation generated in the heating element layer 13 is ideally the frequency f1 of the drive input waveform. The frequency f2 is twice that of the drive input waveform f1, and a dense wave having a frequency approximately twice that of the drive input waveform f1 can be generated. That is, the above-described transmission element 10 has a flat frequency characteristic, and the frequency of the generated dense wave can be changed over a wide range. Further, in the above-described transmission element 10, for example, a half-cycle isolated wave having a sine wave waveform is applied as a drive input waveform from the drive circuit 20 to the pair of pads 14, 14, so that a sparse wave having approximately one cycle with less reverberation is provided. Can be generated.

  Further, the capacitance type microphone constituting the wave receiving element 30 is formed by utilizing micromachining technology, and as shown in FIG. 3, a window hole 31a penetrating in the thickness direction through the silicon substrate is formed. A rectangular frame 31 is provided, and a cantilever-type pressure receiving portion 32 is disposed on one surface side of the frame 31 so as to straddle two opposing sides of the frame 31. Here, a thermal oxide film 35, a silicon oxide film 36 covering the thermal oxide film 35, and a silicon nitride film 37 covering the silicon oxide film 36 are formed on one surface side of the frame 31, and one end of the pressure receiving portion 32. Is supported by the frame 31 via the silicon nitride film 37, and the other end faces the silicon nitride film 37 in the thickness direction of the silicon substrate. Further, a fixed electrode 33 a made of a metal thin film (for example, a chromium film) is formed on a surface of the silicon nitride film 37 facing the other end of the pressure receiving portion 32, and the silicon nitride film 37 at the other end of the pressure receiving portion 32 is formed. A movable electrode 33b made of a metal thin film (for example, a chromium film) is formed on the opposite side of the opposite surface. A silicon nitride film 38 is formed on the other surface of the frame 31. The pressure receiving portion 32 is constituted by a silicon nitride film formed in a separate process from the silicon nitride films 37 and 38 described above.

  In the wave receiving element 30 composed of the capacitance type microphone having the configuration shown in FIG. 3, a capacitor having the fixed electrode 33a and the movable electrode 33b as electrodes is formed, so that the pressure receiving portion 32 receives the pressure of the dense wave. As a result, the distance between the fixed electrode 33a and the movable electrode 33b changes, and the capacitance between the fixed electrode 33a and the movable electrode 33b changes. Therefore, if a DC bias voltage is applied between pads (not shown) provided on the fixed electrode 33a and the movable electrode 33b, a minute voltage change occurs between the pads in accordance with the sound pressure of the dense wave. The sound pressure of the dense wave can be changed to an electric signal.

  By the way, in the above-described transmission element 10, when the drive input waveform applied to the heating element layer 13 via the pair of pads 14 and 14 is a Gaussian-shaped isolated wave, a Gaussian-shaped sparse / dense wave is converted into a single pulse. Waves can be transmitted, and side lobes can be prevented from being formed in the dense wave transmitted from the wave transmitting element 10.

  Here, the sound pressure of the dense wave transmitted from the transmission element 10 by changing the pulse width of the drive input waveform energized to the transmission element 10 in the period of 10 μs to 50 μs of one cycle of ultrasonic waves of about 100 kHz to 20 kHz. As a result, the results shown in FIG. 4 were obtained, and it was found that the change in sound pressure was small even when the pulse width was changed.

  Similarly, when the directivity of the dense wave transmitted from the transmission element 10 was measured by changing the pulse width of the drive input waveform in the range of 10 μs to 50 μs, the result shown in FIG. 5 was obtained. It was found that the directivity angle can be changed by changing the pulse width in the range of 10 μs to 25 μs. Note that the directivity angle on the vertical axis in FIG. 5 is the minimum sound pressure required at the maximum measurement distance when the receiving element 30 detects the dense wave reflected by the object Ob existing at the desired maximum measurement distance. It is an angle defined as the maximum angle of the radiation range where a prescribed predetermined sound pressure is obtained.

  By the way, the transmission control unit 20 that controls the transmission element 10 has a variable pulse width of the drive input waveform energized to the heating element layer 13 of the transmission element 10, and the transmission element 10 is controlled by controlling the pulse width. It is configured to be able to control the directivity of the dense wave generated from the.

  Specifically, as shown in FIG. 6, the transmission control unit 20 includes three charging / discharging circuits 21, 22, and 23, and each charging / discharging circuit 21, 22, and 23 is connected to the DC voltage source E. Capacitors C1, C2, C3 are connected between both ends via a charging switch SW0, and one end on the thyristor Th1, Th2, Th3 side in a series circuit of thyristors Th1, Th2, Th3 and inductors L1, L2, L3 is a capacitor C1. , C2 and C3 are connected to the high potential side, and the other ends of the inductors L1, L2 and L3 are connected to the transmission element 10. Further, pulse width switching switches SW1, SW2, SW3 are inserted between the charging switch SW0 and the capacitors C1, C2, C3, and further, the pulse width switching switches SW1, SW2, SW3 and the capacitors C1, C2, Between C3, variable power supply units VE1, VE2, and VE3 including a booster circuit that boosts the output voltage of the DC voltage source E are inserted.

  In the transmission control unit 20 illustrated in FIG. 6, the pulse widths of the drive input waveforms energized to the transmission element 10 are made different by changing the circuit constants of the three charge / discharge circuits 21, 22, and 23. . More specifically, since the resistance value of the transmission element 10 is the same regardless of the charge / discharge circuits 21, 22, 23, the time constants of the charge / discharge circuits 21, 22, 23 are set to the capacitances of the capacitors C1, C2, C3. And the inductances of the inductors L1, L2, and L3 are adjusted so that the pulse widths of the drive input waveforms supplied from the charge / discharge circuits 21, 22, and 23 to the transmission element 10 are different. Further, in the transmission control unit 20, the outputs of the variable power supply units VE1, VE2, and VE3 are set so that the sound pressure of the dense wave transmitted from the transmission element 10 is substantially constant regardless of the pulse width of the drive input waveform. The voltage is adjusted.

Here, in the sensor device of this reference example , the operation unit of the above-described pulse width switching switches SW1, SW2, SW3 is provided in the sensor device body, and the pulse width switching switch SW1, SW1 is operated by operating the operation unit. SW2 and SW3 can be selectively turned on, and any one of the three charge / discharge circuits 21, 22, and 23 can be selectively charged / discharged. Yes.

  In the above-described charging / discharging circuits 21, 22, and 23, the capacitors C1, C2, and C3 are charged while the charging switch SW0 and the pulse width switching switches SW1, SW2, and SW3 are on. An energization timing control circuit (not shown) that controls the energization timing of the drive input waveform detects the voltages across the capacitors C1, C2, and C3, and the voltages across the capacitors C1, C2, and C3 are set for each. When a predetermined threshold value is exceeded, the charging switch SW0 is turned off and a control signal is given to the gates of the thyristors Th1, Th2, Th3. That is, in the charge / discharge circuits 21, 22, 23 having the configuration shown in FIG. 6, charges are accumulated in the capacitors C1, C2, C3 from the DC voltage source E through the variable power supply units VE1, VE2, VE3, and the capacitors C1, C2, C3. When the voltage at both ends of each exceeds a predetermined threshold value set for each, a control signal is given from the energization timing control circuit to the thyristors Th1, Th2, Th3, the thyristors Th1, Th2, Th3 are turned on, and the transmitting element 10 A drive input waveform (voltage) is applied between the pads 14 and 14, and a dense wave is transmitted along with the temperature change of the heating element layer 13.

  By the way, the above-described signal processing unit 50 is configured to detect the object Ob using the output of the wave receiving element 30 in the wave receiving period defined according to the energization timing of the drive input waveform.

  Here, the signal processing unit 50 includes a signal amplification unit 51 configured by an amplifier that amplifies the reception signal output from the reception element 30, and an analog reception signal amplified by the signal amplification unit 51. The A / D conversion unit 52 that converts and outputs the wave signal, the memory 53 that stores the output of the A / D conversion unit 52, and the energization timing from the transmission control unit 20 to the transmission element 10 are controlled. The distance to the object Ob using the data of the received signal stored in the memory 53 by operating the A / D converter 52 for a predetermined receiving period when receiving a timing signal output in synchronization with the control signal. And a calculation unit 54 composed of a microcomputer for performing a calculation to obtain the above.

In the present reference example, the A / D conversion unit 52 receives a wave that makes the received signal output from the wave receiving element 30 valid only during a predetermined wave receiving period after the wave transmitting element 10 transmits a dense wave. Although it has a function as a timing control unit, the reception timing control unit is provided between the reception element 30 and the memory 53 separately from the A / D conversion unit 52 and receives signals outside the reception period. The signal may be invalidated. Further, in this reference example, since the above-described capacitance type microphone is used as the wave receiving element 30, the wave receiving element 30 converts a sparse wave into a wave receiving signal and converts it only during the wave receiving period. The receiving element 30 may be configured to operate in response to a timing signal from the energization timing control circuit so as to output. In the present reference example, by having the above-described reception timing control unit, the reception signal output from the reception element 30 is effective only during the reception period, and from the reception element 30 other than the reception period. Since the output received signal becomes invalid, the influence of noise such as external noise and multiple reflection can be reduced.

  The arithmetic unit 54 receives the timing signal (that is, the timing at which a sparse wave is transmitted from the transmission element 10) and the time when the digital reception signal is stored in the memory 53 (in the signal processing unit 50). If the delay time is ignored, the time difference (in other words, the timing at which the dense wave is received by the wave receiving element 30) (in other words, the wave receiving element 30 receives the dense wave after the wave transmitting element 10 transmits the dense wave). Distance calculating means for calculating the distance to the object Ob based on the time until the wave travels. The distance calculation means of the calculation unit 54 can be realized by mounting an appropriate program on the microcomputer.

In the sensor device of this reference example described above, the acoustic wave that generates a dense wave by applying a thermal shock to the air due to the temperature change of the heating element layer 13 when the wave transmitting element 10 energizes the heating element layer 13 that is a heating part. The pulse width of the drive input waveform that is composed of the generation element and is energized to the heating element layer 13 of the transmission element 10 is variable, and the directivity of the dense wave generated from the transmission element 10 can be controlled by controlling the pulse width. Since the transmission control unit 20 is provided, a movable mechanism for adjusting the radiation range of the dense wave using a radiation range adjustment member or adjusting the direction of the transmission element made of a piezoelectric element is provided as in the prior art. A pulse of a drive input waveform energized from the transmission control unit 20 to the heating element layer 13 of the transmission element 10 without adjusting the radiation range of the dense wave by adjusting the direction of the transmission element made of a piezoelectric element by a movable mechanism. By controlling the width It is possible to change the compression wave directivity to be generated from the wave element 10, because it adjusts the detection area, it becomes possible to adjust the detection area with a simple configuration as compared with the prior art. In short, in the sensor device of the present reference example, the detection area of the object Ob can be adjusted without attaching the radiation range adjusting member or adjusting the direction of the transmitting element 10 or the receiving element 30.

Further, the sensor device of this reference example includes the above-described pulse width switching switches SW1, SW2, SW3 as switches for instructing the change of the pulse width of the drive input waveform, and the pulse width switching switches SW1, SW2, SW3. Since the operation unit can be operated from the outside, it is possible to easily adjust or change the detection area on the spot according to the surrounding situation for each installation location of the sensor device and the purpose of the user. It becomes possible.

(Embodiment 1 )
Although the basic configuration of the sensor device of the present embodiment is substantially the same as the sensor device of the reference example, the illustration is omitted. However, the energization timing control circuit of the transmission control unit 20 is the lower charge / discharge circuit 21 in FIG. The charging switch SW0 is turned on and off and the pulse width switching switches SW1, SW2, and SW3 are turned on and off so that the middle charging / discharging circuit 22 in FIG. And the timing of giving different control signals to the thyristors Th1, Th2 and Th3 are different. In short, in the sensor device of this embodiment, the energization timing control circuit sequentially changes the pulse width of the drive input waveform, so that a plurality of types of dense waves with different directivities are sequentially transmitted from the wave transmitting element 10. This is different from Reference Example 1 in that it is configured as described above.

  Further, the signal processing unit 50 defines a reception period according to each energization timing of the drive input waveform for each pulse width, and detects the object Ob using the output of the reception element 30 in each specified reception period. Is configured to do.

  That is, the received signal of the receiving element 30 in each receiving period is stored in the memory 53 of the signal processing unit 50. In addition, the calculation unit 54 of the signal processing unit 50 is configured to perform calculation for obtaining the distance to the object Ob using the received signal data stored in the memory 53 and to estimate the area where the object Ob exists. ing.

Here, the arithmetic unit 54, in addition to the distance calculation means that hand described in Reference Example, the area estimation means present in the object Ob by using the data of the received signals of the wave receiving devices 30 stored in the memory 53 I have. Here, the area estimation means is based on the relationship between the output of the wave receiving element 30 and the directivity corresponding to each pulse width in each wave receiving period defined according to the energization timing of each drive input waveform for each pulse width. The area where the object Ob exists is estimated. For example, it is assumed that the relative positional relationship between the transmission element 10 and the object Ob is as shown in FIG. 7A, and the positions of the transmission element 10 and the object Ob do not change. It is assumed that the directivity angle of the sparse / dense wave transmitted from 10 gradually increases as shown in FIG. 10 (a), FIG. 10 (b), and FIG. Then, in the case of FIG. 7A, the object Ob is not detected, and in the case of FIGS. 7B and 7C, the object Ob is detected. Therefore, the output of the wave receiving element 30 in each wave receiving period. And the area where the object Ob exists can be estimated based on the relationship between the directivity corresponding to each pulse width. In the example of FIG. 7, it is estimated that the object Ob exists in an area obtained by removing the detection area in the case of FIG. 7A from the detection area in the case of FIG. The distance calculation means and the area estimation means of the calculation unit 54 can be realized by installing an appropriate program in the microcomputer.

  As described above, in the sensor device according to the present embodiment, the transmission control unit 20 has the pulse width of the drive input waveform so that a plurality of types of dense waves having different directivities are sequentially transmitted from the transmission element 10. Are sequentially changed, and the signal processing unit 50 detects the object Ob using the output of the wave receiving element 30 in each wave receiving period defined according to the energization timing of each drive input waveform of each pulse width. It is possible to set the detection area.

  In addition, according to the sensor device of the present embodiment, the ultrasonic pressure generating element using the conventional piezoelectric element increases the sound pressure by radiating a continuous wave or a plurality of cycles of dense waves. Since the generation period can be generated from the element 10 and the acoustic wave having a high sound pressure can be generated, the energization timing interval of the drive input waveform can be shortened. In addition, since each of the dense waves reflected by the object Ob can be received separately by the receiving element 30 at relatively short time intervals to obtain independent received signals, the time resolution is increased. It is also possible.

  By the way, in the above-mentioned embodiment, the calculating part 54 has the directivity corresponding to each pulse width and the output of the receiving element 30 in each receiving period prescribed | regulated according to each energization timing of each drive input waveform of each pulse width. Area estimation means for estimating the area where the object Ob is present based on the relationship between the directivity and the directivity angle of the dense wave sequentially transmitted by further increasing the number of charge / discharge circuits in the transmission control unit 20. The difference is made small, and the calculation unit 54 outputs the output of the wave receiving element 30 in each wave receiving period and the directivity corresponding to each pulse width defined according to the energization timing of each drive input waveform of each pulse width. Based on the relationship, an azimuth estimating means for estimating the azimuth in which the object Ob exists (the arrival direction of the dense wave reflected by the object Ob) may be provided. By providing such an azimuth estimation means, it is possible to estimate the azimuth in which the object Ob exists, and it is also possible to estimate the shape and movement of the object Ob.

(Embodiment 2 )
By the way, in the sensor device provided with the direction estimating means in the calculation unit 54 as described above, it is possible to estimate the direction in which the object Ob exists, but for example, the relative relationship between the wave transmitting element 10 and the object Ob. 7A, whether the object Ob exists obliquely above the transmission element 10 as shown in FIG. 7A, or obliquely below the transmission element 10 (that is, the actual object It is impossible to identify whether the object Ob is present at a position obtained by mirror-reversing the position where the Ob is present. Therefore, a system is considered in which a plurality of sensor devices are arranged so as not to interfere with each other, and signal processing for obtaining the direction in which the object Ob exists is performed based on the detection result of each sensor device. In such a system, the installation work of the sensor device becomes troublesome, the whole system becomes large, and the signal processing circuit becomes complicated.

  On the other hand, as shown in FIG. 8, the sensor device of the present embodiment includes a plurality (two in the illustrated example) of sensor units 1 including the sensor device including the azimuth estimation unit in the calculation unit 54. A shielding plate 60 that is arranged adjacent to each other on the same plane and prevents the dense wave transmitted from the wave transmitting element 10 of the other sensor unit 1 and reflected by the object Ob from entering the wave receiving element 30 is provided. There is a feature in that. Here, according to the sensor device having the configuration shown in FIG. 8, in the sensor unit 1 on the left side (upper side in FIG. 8) of the shielding plate 60, the detection area is set on the left side of the shielding plate 60. In the sensor unit 1 on the right side (lower side in FIG. 8), since the detection area is set on the right side of the shielding plate 60, it is possible to more accurately estimate the azimuth in which the object Ob exists in each sensor unit 1. Therefore, the azimuth in which the object Ob exists estimated by any one of the sensor units 1 can be uniquely processed as the azimuth in which the object Ob exists, and the distance to the object Ob is obtained with a simple configuration and the object It is possible to estimate the orientation in which Ob is present more accurately.

  In the above-described example, the incident direction of the dense wave reflected by the object Ob by the shielding plate 60 is limited, but the radiation range of the dense wave transmitted from the wave transmitting element 10 is limited. You may make it restrict | limit with the shielding board 60. FIG. In short, the shielding plate 60 may be arranged so that interference between different sensor units 1 is prevented.

(Embodiment 3 )
As shown in FIG. 9, the self-propelled tobot of the present embodiment includes a robot main body 71, traveling means 72 including wheels that can move the robot main body 71, and two robots mounted on the robot main body 71 that detect obstacles. An obstacle detection device 73 and a travel control means (not shown) for controlling the travel means 72 so that the robot main body 71 moves while avoiding the obstacle detected by each obstacle detection device 73 are provided. The sensor device described in the first embodiment is used as the obstacle detection device 73. In the example shown in FIG. 9, one obstacle detection device 73 is attached to each of the front side (left side in FIG. 9) and the rear side (right side in FIG. 9) of the robot main body 71.

  By the way, when mounting a conventional sensor device as an obstacle detection means on a self-propelled robot, or when mounting a plurality of ultrasonic sensors with a narrow detection area, the attachment position of the obstacle detection means with respect to the robot body 71 can be freely set. As the degree is lowered, the mounting work becomes troublesome, and the load of the self-running robot having a complicated control system and drive system becomes heavy, and the volume and weight of the self-running robot increase.

  On the other hand, in the present embodiment, the detection area of the obstacle detection device 73 in the self-running robot can be adjusted with a simpler configuration than in the past, and the attachment position of the obstacle detection device 73 with respect to the robot body 71 can be freely set. The degree of installation becomes higher and the installation work becomes easier, and the load on a self-propelled robot equipped with a complicated control system and drive system can be reduced.

In the above-described example, the sensor device described in the first embodiment is employed as the obstacle detection device 73. However , the sensor device described in the reference example or other embodiment 2 may be employed. .

It is a schematic block diagram of the sensor apparatus of a reference example . It is a schematic sectional drawing of the wave transmitting element same as the above. The wave receiving element in the same as above is shown, (a) is a schematic perspective view partly broken, and (b) is a schematic sectional view. It is operation | movement explanatory drawing of the wave transmission element in the same as the above. It is operation | movement explanatory drawing of the wave transmission element in the same as the above. It is a schematic circuit diagram of the wave transmission control part in the same as the above. FIG. 3 is an operation explanatory diagram of the sensor device of the first embodiment. It is a schematic block diagram of the sensor apparatus of Embodiment 2 . It is a schematic block diagram of the self-propelled robot of Embodiment 3 .

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Transmission element 20 Transmission control part 30 Reception element 50 Signal processing part 51 Signal amplification part 52 A / D conversion part 53 Memory 54 Operation part Ob Object

Claims (4)

A transmitting element for transmitting a sparse / dense wave; and a receiving element for receiving a sparse wave transmitted from the transmitting element and reflected by an object and converting the received sparse / dense wave into a received signal that is an electrical signal; A signal processing unit that detects an object using a received signal output from the wave receiving element, and the wave transmitting element gives a thermal shock to the air due to a temperature change of the heat generating part when the heat generating part is energized The pulse width of the drive input waveform that energizes the heat generating part of the transmission element is variable, and the directivity of the dense wave generated from the transmission element by controlling the pulse width The transmission control unit can sequentially change the pulse width of the drive input waveform so that multiple types of dense waves with different directivities are sequentially transmitted from the transmission element. , The signal processing unit is the drive input waveform for each pulse width. An object is detected by using the output of the receiving element in each receiving period defined according to each electric timing, and each receiving period defined according to each energization timing of the drive input waveform for each pulse width A sensor device comprising area estimation means for estimating an area where an object exists based on a relationship between an output of a wave receiving element and directivity corresponding to each pulse width . A transmitting element for transmitting a sparse / dense wave; and a receiving element for receiving a sparse wave transmitted from the transmitting element and reflected by an object and converting the received sparse / dense wave into a received signal that is an electrical signal; A signal processing unit that detects an object using a received signal output from the wave receiving element, and the wave transmitting element gives a thermal shock to the air due to a temperature change of the heat generating part when the heat generating part is energized The pulse width of the drive input waveform that energizes the heat generating part of the transmission element is variable, and the directivity of the dense wave generated from the transmission element by controlling the pulse width has a controllable transmitting control unit, transmitting control unit, the pulse width of the drive input waveform is sequentially changed so as to be transmitting a plurality of types of compressional waves from transmission waves element different directivities respectively successively , signal processing unit, for each pulse width each drive input waveform A shall detect an object using the output of the put that received wave element in each wave receiving period defined in accordance with the respective electric timing, the signal processing unit are each conduction timing of each pulse width each drive input waveform it characterized in that it comprises a direction estimation means for estimating the existing orientation of an object based on a relationship between the output and the directivity corresponding to each pulse width of the wave receiving devices of each wave receiving period defined in accordance sensor apparatus. A plurality of sensor units comprising the sensor device according to claim 2 are arranged on the same plane, and prevent a dense wave transmitted from a wave transmitting element of another sensor unit and reflected by an object from entering the wave receiving element. It is provided with a shielding plate which features and to Rousset capacitors device. The robot main body, traveling means that can move the robot main body, an obstacle detection device that is mounted on the robot main body and detects an obstacle, and the robot main body moves while avoiding the obstacle detected by the obstacle detection device and a traveling control means for controlling the driving means so as, self-propelled robot you characterized by using a sensor device according to any one of claims 1 to 3 as an obstacle detecting device.

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