Flexible positioner with adjustable spatial detection range and detection method

Abstract

The application discloses a flexible positioner with adjustable spatial detection range and a detection method. The positioner is mainly composed of an upper packaging layer, an upper electrode layer, an ultrasonic sensitive layer, a lower electrode layer and a lower packaging layer which are stacked from top to bottom, a polyester fiber backing layer is embedded in the lower part of the upper packaging layer, the lower electrode layer is connected with a signal generator, the method comprises the following steps: folding the positioner in a planar form into a three-dimensional form, completing detection of X, Y and Z surfaces by rotating the whole positioner and swinging the folding block, and finally completing positioning of the object to be detected. The method adopts the principle of combined ultrasonic ranging and the algorithm of spatial affine transformation, and completes the positioning work of the detection object through ultrasonic ranging in at least three dimensions. The PVDF adopted by the application is more sensitive than other piezoelectric materials, and the method of multi-directional detection is adopted to avoid the error of ultrasonic ranging and the interference of the environment.

Description

Technical Field

[0001] This invention relates to a locator and detection method in the field of intelligent robots, specifically a flexible locator and detection method with an adjustable spatial detection range. Background Technology

[0002] With the rapid development of the robotics industry and the emergence of Intelligent Manufacturing 3.0, the requirements for robot operations and production are constantly increasing, and the precision requirements for robots in tasks such as flaw detection, positioning, and self-inspection are also gradually rising. However, traditional ultrasonic testing often has limitations such as large size and bulkiness, making it unsuitable for installation on robots that typically require portability. Even rapidly developing vision technologies with higher detection precision have similar drawbacks and are subject to environmental constraints, such as interference problems caused by the large size of cameras and CCD sensors during installation, or the required lighting conditions during operation. Therefore, miniaturized ultrasonic testing devices have enormous application potential.

[0003] Mobile robots have varying requirements for ultrasonic sensing capabilities depending on their specific operational objectives, which can be broadly categorized into two applications: internal detection of external objects and self-inspection of the robot's internal structure. Both applications share the common requirement of high precision, flexibility, and small size for the ultrasonic detection device. The working principle of a flexible ultrasonic positioner is based on the piezoelectric properties of piezoelectric materials. Proven piezoelectric materials include piezoelectric crystals, piezoelectric ceramics, and piezoelectric polymers. Due to the relatively high relative permittivity of the piezoelectric materials used in commonly used ultrasonic detection devices, current ultrasonic positioning applications in medicine and industry often only provide the approximate location of the object being detected, rather than its precise coordinates. High-sensitivity piezoelectric polymers can effectively solve this problem. Furthermore, flexible ultrasound can effectively address the surface coupling and installation interference problems that are common in traditional ultrasound. Currently, there is a lack of ultrasonic detection devices made using high-sensitivity piezoelectric polymers. Summary of the Invention

[0004] To address the problems existing in the background art, the present invention provides a flexible positioner with an adjustable spatial detection range and a detection method.

[0005] The technical solution adopted in this invention is:

[0006] I. A flexible positioner with adjustable spatial detection range:

[0007] It is mainly composed of an upper encapsulation layer, an upper electrode layer, an ultrasonic sensitive layer, a lower electrode layer, and a lower encapsulation layer stacked from top to bottom. The polyester fiber backing layer is embedded in the lower part of the upper encapsulation layer, and the lower surface of the polyester fiber backing layer is flush with the lower surface of the upper encapsulation layer. The lower electrode layer is connected to an external signal generator.

[0008] The L-shaped locator is used to locate the object to be detected. The ultrasonic waves emitted by the locator will be reflected when they encounter the object to be detected. By adjusting the position and shape of the locator, the position information of the object to be detected can be obtained.

[0009] The lower part of the upper encapsulation layer is provided with several rectangular grooves. The polyester fiber backing layer is mainly formed by several polyester fiber sheets arranged in an L-shaped array at intervals. Each polyester fiber sheet is embedded in the rectangular groove of the upper encapsulation layer. The ultrasonic sensitive layer is mainly formed by several piezoelectric units arranged in an L-shaped array at intervals. The number and arrangement position of the polyester fiber sheets in the polyester fiber backing layer and the piezoelectric units in the ultrasonic sensitive layer are the same and aligned.

[0010] Both the upper and lower electrode layers are mainly composed of several circular electrodes. The circular electrodes in the upper and lower electrode layers are connected by electrode lines. The number and arrangement of the circular electrodes in the upper and lower electrode layers are the same and aligned. The circular electrodes in the upper and lower electrode layers are respectively located on both sides of the piezoelectric unit.

[0011] The upper encapsulation layer is an "L"-shaped structure mainly composed of a first encapsulation block, a second encapsulation block, and a third encapsulation block. The second and third encapsulation blocks are located on both sides of the first encapsulation block, and the second and third encapsulation blocks are movably connected to the first encapsulation block through hinges.

[0012] The lower encapsulation layer is an "L"-shaped structure mainly composed of a fourth encapsulation block, a fifth encapsulation block, and a sixth encapsulation block. The fifth and sixth encapsulation blocks are located on both sides of the fourth encapsulation block, and both the fifth and sixth encapsulation blocks are movably connected to the fourth encapsulation block via hinges.

[0013] The first, second, and third encapsulation blocks are arranged in the same and aligned positions as the fourth, fifth, and sixth encapsulation blocks, respectively.

[0014] The piezoelectric unit includes a copolymer film piezoelectric sheet and a polyimide fixing edge. Four polyimide fixing edges are fixedly connected around the polyimide fixing edge. The number and arrangement of the copolymer film piezoelectric sheet and the polyester fiber sheet are the same and aligned. The upper and lower surfaces of the copolymer film piezoelectric sheet are plated with silver.

[0015] A suspended ground wire is also connected to the electrode line in the lower electrode layer, and a lead-out electrode is connected to the circular electrode at the corner of the lower electrode layer. The lead-out electrode is connected to an external signal generator.

[0016] The locator has two forms: planar and three-dimensional. The locator mainly consists of an "L"-shaped structure composed of a first folding block, a second folding block, and a third folding block. The second and third folding blocks are located on both sides of the first folding block and are movably connected to the first folding block via hinges. In the planar form, the first, second, and third folding blocks of the locator are connected to form a foldable planar whole, with the hinge serving as the folding edge of the locator. In the three-dimensional form, the locator is formed by folding the planar whole along the folding edge.

[0017] II. A method for detecting a flexible positioner, comprising the following steps:

[0018] Step 1: Using an external robot, the planar locator is folded along the hinge into a three-dimensional form with three perpendicular folded blocks. This form is taken as the initial three-dimensional form of the locator. The planes containing the first, second, and third folded blocks are designated as the first plane (X-plane), the second plane (Y-plane), and the third plane (Z-plane), respectively. An initial spatial rectangular coordinate system (o0x0y0z0) is established for the locator in its initial three-dimensional form. The intersection of the first plane (X-plane), the second plane (Y-plane), and the third plane (Z-plane) is taken as the origin O0 of the initial spatial rectangular coordinate system (o0x0y0z0). The x0, y0, and z0 axes of the initial spatial rectangular coordinate system (o0x0y0z0) are perpendicular to the first plane (X-plane), the second plane (Y-plane), and the third plane (Z-plane), respectively. The locator is located in the initial spatial rectangular coordinate system (o0x0y0z0). o The positive directions of the x0, y0, and z0 axes of the y0z0 system;

[0019] Step 2: Complete the detection of the first plane, X-plane.

[0020] Turn on the signal generator to make the locator emit ultrasonic waves, place the locator around the object to be detected, and simultaneously rotate the locator sequentially around the initial spatial Cartesian coordinate system o0x. o When the x0 and z0 axes of the y0z0 system rotate, and the signal generator detects an echo signal generated on the first plane X, the difference between the excitation time and the echo time of the first plane X at this moment is recorded as the first time of flight (TOF). X ;

[0021] Step 3: Complete the detection of the second plane, Y-plane.

[0022] The second folding block of the positioner is rotated around the hinge between the first and second folding blocks. When the signal generator detects an echo signal generated on the second plane Y-plane, the difference between the excitation time and the echo time of the echo signal on the second plane Y-plane at this time is recorded as the second time of flight (TOF). Y ;

[0023] Then, the current shape of the locator is taken as the second three-dimensional shape, and a second spatial rectangular coordinate system o2x2y2z2 is established for the locator in the second three-dimensional shape: the intersection of the first plane X, the second plane Y, and the third plane Z is taken as the origin O2 of the second spatial rectangular coordinate system o2x2y2z2. The x2 axis, y2 axis, and z2 axis of the second spatial rectangular coordinate system o2x2y2z2 are perpendicular to the first plane X, the second plane Y, and the third plane Z, respectively. The locator is located in the positive directions of the x2 axis, y2 axis, and z2 axis of the second spatial rectangular coordinate system o2x2y2z2.

[0024] Step 4: Complete the detection of the third plane Z-plane.

[0025] The third folding block of the positioner is rotated around the hinge between the first and third folding blocks. When the signal generator detects an echo signal generated on the third plane Z-plane, the difference between the excitation time and the echo time of the echo signal on the third plane Z-plane at this time is recorded as the third time of flight (TOF). Z ;

[0026] Step 5: Locate the object to be detected:

[0027] Obtain the coordinates c2(x) of the object to be detected in the second spatial rectangular coordinate system o2x2y2z2. p y p , z p ):

[0028] x p =v·TOF X / 2

[0029] y p =v·TOF Y / 2

[0030] z p =v·TOF Z / 2

[0031] Where v is the speed of sound propagation, x p y p , z p These are the coordinates of the object to be detected on the x2 axis, y2 axis, and z2 axis in the second spatial rectangular coordinate system o2x2y2z2.

[0032] The distance between each electrode line in the same electrode layer is controlled to be greater than 0.5mm. A floating ground wire is provided in the lower electrode layer to reduce mutual inductance and capacitance problems that may occur during high-frequency signal transmission. Lead-out electrodes are provided in the lower electrode layer for easy connection to external instruments such as external signal generators, oscilloscopes, or circuit boards.

[0033] The circular electrode has a diameter of 2 mm and is used to excite the ultrasonic sensitive layer. The upper and lower electrode layers are tightly bonded to the copolymer film piezoelectric sheet.

[0034] The isolation blocks are used to isolate the upper and lower electrode layers to prevent short circuits. The diameter of the isolation blocks must be greater than the width of the electrode lines. The isolation blocks are distributed around the circular electrodes and lead-out electrodes.

[0035] The polyester fiber backing layer is composed of polyester fiber sheets with the same area as the copolymer film piezoelectric sheet. The lower surface of the polyester fiber sheet is tightly attached to the electrode layer, and the upper surface of the polyester fiber sheet is tightly attached to the groove at the corresponding position of the upper encapsulation layer.

[0036] The detection range is:

[0037] The detection range of the flexible positioner is determined by three factors: the gap of the excitation voltage signal, the attenuation of the ultrasonic wave, and the rotation angle of the auxiliary working surfaces Y and Z.

[0038] When the gap between the excitation voltage signals during operation is t, the maximum detection distance can be obtained from the detection process as v·t / 2. If this distance is exceeded, the echo signal may be submerged in the excitation voltage signal or interfere with the subsequent echo signal, causing the measured distance to be distorted.

[0039] Ultrasonic waves attenuate when propagating in air, and their sound pressure change can be given by the following formula.

[0040] p x =p0·e -afx

[0041] Where, p x Let p0 be the sound pressure at a distance x from the ultrasonic source, e be the natural logarithm, a be the attenuation coefficient of the ultrasonic wave, f be the frequency of the ultrasonic wave, and x be the distance the ultrasonic wave travels. In this invention, the echo sound pressure is required to be at least 1 / 4 of the emitted sound pressure. Given that this example operates in air, the attenuation coefficient varies with ambient temperature by 1–2 dB / (cm*MHz). The operating frequency in this example is 30–50 kHz. Therefore, in this example, the ultrasonic wave propagation distance is within the range of 25°C.

[0042]

[0043] The maximum accurate coordinate that can be measured in the working detection space coordinate system o2x2y2z2 is 1 / 2 of the propagation distance, where i is X, Y or Z.

[0044] According to the definition in the testing process, considering the limitations of the robot's working range on the actual auxiliary working surfaces (Y-plane and Z-plane), the rotation angle θ of the auxiliary working surfaces (Y-plane and Z-plane) is... Y and θ ZThe range of all values ​​is limited to (-π / 3, π / 3).

[0045] As can be seen from the detection process of this invention, the coordinates of the object to be detected measured in the rectangular coordinate system o1x1y1z1 in the workspace are c1:

[0046]

[0047] Substituting c2, we get

[0048]

[0049] In summary, the detection distance in this example is... Where min{} denotes the minimum value function, c1(k) min Let c1 represent the minimum value of the k-th element in the coordinate vector c1, where k = 1, 2, 3.

[0050] The detection accuracy is:

[0051] In this example, the first plane X, the second plane Y, and the third plane Z are all 20mm*20mm squares, and each ultrasonic sensitive unit in the second and third planes works synchronously. Therefore, the energy of the ultrasonic waves emitted by each working surface is concentrated in a 20mm*20mm square plane. That is, the volume of the object to be detected in this example is required to be at least a spherical object with a diameter of 20mm. If the volume is smaller than the volume of the sphere, it may cause the inability to locate.

[0052] This invention utilizes flexible materials such as polydimethylsiloxane (PDMS) and vinylidene fluoride-trifluoroethylene copolymer (PVDF-TrFE) to avoid surface coupling problems that may occur during folding or in traditional ultrasonic testing. The lower relative permittivity and other parameters of the PVDF-TrFE copolymer ensure high detection accuracy, while the backing layer design minimizes environmental interference and aftershocks. The fixed edge design of the PI polyimide reduces interference between adjacent units in ultrasonic sensing, and the higher rigidity of PI polyimide compared to PVDF-TrFE ensures accurate positioning of the piezoelectric unit, reducing environmental interference with ultrasonic sensing. Furthermore, the small size and simple detection principle of the flexible positioner ensure low manufacturing cost and high portability, while the folding design addresses positioning issues difficult to achieve with traditional ultrasonic testing and eliminates blind spots such as corners.

[0053] The signal generator provides an excitation voltage signal to the locator. The voltage difference between the two electrode layers allows the ultrasonic sensitive layer to emit ultrasonic waves under the action of the signal generator. When the ultrasonic waves emitted by the ultrasonic sensitive layer in the locator encounter the object to be detected, a reflection phenomenon occurs. The reflection phenomenon causes the locator to output a voltage signal to the signal generator. The signal generator is used to read the voltage signal to determine whether the ultrasonic waves emitted by the locator have encountered the object to be detected, and thus locate the object to be detected.

[0054] This invention employs the principle of combined ultrasonic ranging and the algorithm of spatial affine transformation to locate the object being detected through ultrasonic ranging in at least three dimensions. The PVDF-TrFE used in this invention exhibits a more sensitive response than other piezoelectric materials, and the multi-directional detection method avoids errors in ultrasonic ranging and environmental interference.

[0055] The beneficial effects of this invention are as follows:

[0056] 1. The PVDF-TrFE copolymer used in this invention as a piezoelectric material ensures high-precision detection, while the polyester fiber backing layer reduces high noise interference caused by high-precision detection. Simultaneously, a suspended ground wire is incorporated into the electrode line arrangement to reduce crosstalk that may be caused by high-frequency vibrations, and PI polyimide is placed around the piezoelectric unit to absorb additional sound waves, reducing mutual interference between diffracted ultrasonic waves from different working surfaces.

[0057] 2. This invention uses flexible PDMS material as a substrate to ensure the foldability of the flexible positioner and the degree of fit after folding, minimizing potential surface coupling problems. Through affine transformation of the spatial coordinate system, the measured detection coordinates are transformed into coordinates in a fixed coordinate system, achieving high-precision, low-interference positioning of the internal detection object. Attached Figure Description

[0058] Figure 1 This is a layered exploded view of the flexible positioner structure of the present invention;

[0059] Figure 2 This is a schematic diagram of the upper encapsulation layer structure;

[0060] Figure 3 This is a schematic diagram of the polyester fiber backing layer structure;

[0061] Figure 4 This is a schematic diagram of the upper electrode layer structure;

[0062] Figure 5 This is a schematic diagram of the ultrasonic sensitive layer structure;

[0063] Figure 6 This is a schematic diagram of the lower electrode layer structure;

[0064] Figure 7 This is a schematic diagram of the lower encapsulation layer structure;

[0065] Figure 8 This is a perspective view of the internal structure of the flexible positioner of the present invention;

[0066] Figure 9a This is a schematic diagram of the screen printing plate for the upper electrode layer;

[0067] Figure 9b This is a schematic diagram of the screen printing plate for the lower electrode layer;

[0068] Figure 10a This is a schematic diagram of the overall structure of the upper encapsulation layer mold;

[0069] Figure 10b This is a schematic diagram of the upper encapsulation layer cavity structure;

[0070] Figure 10c This is a schematic diagram of the upper encapsulation layer punch structure;

[0071] Figure 11 This is a schematic diagram of the fixing mechanism for the polyester fiber backing layer and the ultrasonic sensitive layer;

[0072] Figure 12 A schematic diagram of the overall mold for the flexible positioner;

[0073] Figure 13 This is a schematic diagram showing the location of the ultrasound-sensitive layer;

[0074] Figure 14 This is a schematic diagram showing the location of the isolation blocks;

[0075] Figure 15a This is a schematic diagram of the planar shape of the flexible positioner;

[0076] Figure 15b Schematic diagram of the initial spatial rectangular coordinate system o0x0y0z0;

[0077] Figure 15c This is a schematic diagram of the first three-dimensional form;

[0078] Figure 15d This is a schematic diagram of the second three-dimensional form;

[0079] Figure 16 This is a schematic diagram of the second spatial rectangular coordinate system o2x2y2z2.

[0080] In the diagram: 1. Upper encapsulation layer; 2. Polyester fiber backing layer; 3. Upper electrode layer; 4. Ultrasonic sensitive layer; 5. Lower electrode layer; 6. Lower encapsulation layer; 7. Copolymer film piezoelectric sheet; 8. Polyimide fixing edge; 9. Circular electrode; 11. Isolation block; 12. Polyester fiber sheet; 13. Lead-out electrode; 14. Floating ground wire. Detailed Implementation

[0081] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0082] like Figure 1 , Figure 7 and Figure 8 As shown, the positioner is mainly composed of an upper encapsulation layer 1, an upper electrode layer 3, an ultrasonic sensitive layer 4, a lower electrode layer 5, and a lower encapsulation layer 6 stacked from top to bottom. The polyester fiber backing layer 2 is embedded in the lower part of the upper encapsulation layer 1, and the lower surface of the polyester fiber backing layer 2 is flush with the lower surface of the upper encapsulation layer 1. The lower electrode layer 5 is connected to external devices such as a signal generator or an oscilloscope.

[0083] The L-shaped locator is used to locate the object to be detected. The ultrasonic waves emitted by the locator will be reflected when they encounter the object to be detected. By adjusting the position and shape of the locator, the position information of the object to be detected can be obtained.

[0084] The object to be detected is an obstacle, such as the positioning of materials to be grasped by a logistics robot.

[0085] Both the upper encapsulation layer 1 and the lower encapsulation layer 6 are made of polydimethylsiloxane material, and the ultrasonic sensitive layer 4 is made of PVDF-TrFE material.

[0086] like Figure 2 As shown, the lower part of the upper encapsulation layer 1 has several rectangular slots, such as... Figure 3 As shown, the polyester fiber backing layer 2 is mainly formed by several rectangular polyester fiber sheets 12 arranged in an L-shaped array at intervals. Each polyester fiber sheet 12 is embedded in a rectangular groove of the upper encapsulation layer 1, as shown in the figure. Figure 5 As shown, the ultrasonic sensitive layer 4 is mainly formed by several piezoelectric units arranged in an L-shaped array. The number and arrangement of the polyester fiber sheets 12 in the polyester fiber backing layer 2 and the piezoelectric units in the ultrasonic sensitive layer 4 are the same and the arrangement positions are aligned one by one in the vertical direction.

[0087] like Figure 4 and Figure 6 As shown, both the upper electrode layer 3 and the lower electrode layer 5 are mainly composed of several circular electrodes 9. The two circular electrodes 9 in each of the upper electrode layer 3 and the lower electrode layer 5 are connected by electrode lines. The number and arrangement of the circular electrodes 9 in the upper electrode layer 3 and the lower electrode layer 5 are the same and their arrangement positions are aligned vertically. The circular electrodes 9 in the upper electrode layer 3 and the lower electrode layer 5 are respectively set on both sides of the piezoelectric unit. That is, the number and arrangement of the circular electrodes 9 in the polyester fiber sheet 12, the piezoelectric unit, and the electrode layers 3 and 5 are the same and their arrangement positions are aligned vertically.

[0088] The upper encapsulation layer 1 is an "L"-shaped structure mainly composed of a first encapsulation block, a second encapsulation block, and a third encapsulation block. The second and third encapsulation blocks are located on both sides of the first encapsulation block, and the second and third encapsulation blocks are movably connected to the first encapsulation block through hinges. That is, the first encapsulation block is located at the corner of the upper encapsulation layer 1, and the second and third encapsulation blocks are located at both ends of the upper encapsulation layer 1. The first, second, and third encapsulation blocks are all provided with rectangular slots.

[0089] like Figure 7 As shown, the lower encapsulation layer 6 is an "L"-shaped structure mainly composed of a fourth encapsulation block, a fifth encapsulation block, and a sixth encapsulation block. The fifth and sixth encapsulation blocks are located on both sides of the fourth encapsulation block, and both the fifth and sixth encapsulation blocks are movably connected to the fourth encapsulation block through hinges; that is, the fourth encapsulation block is located at the corner of the lower encapsulation layer 6, and the fifth and sixth encapsulation blocks are located at both ends of the lower encapsulation layer 6.

[0090] The first, second, and third encapsulation blocks are arranged in the same positions as the fourth, fifth, and sixth encapsulation blocks, respectively, and their positions are aligned vertically.

[0091] The piezoelectric unit includes a rectangular copolymer film piezoelectric sheet 7 and a polyimide fixing edge 8. Four polyimide fixing edges 8 are fixedly connected around the polyimide fixing edge 8. The number and arrangement of the copolymer film piezoelectric sheet 7 and the polyester fiber sheet 12 are the same and the arrangement positions are aligned vertically. The upper and lower surfaces of the copolymer film piezoelectric sheet 7 are plated with silver.

[0092] The polyimide fixing edge 8 is a thin sheet unit that is slightly thicker than the copolymer film piezoelectric sheet 7. The copolymer film piezoelectric sheets 7 are arranged uniformly at certain intervals, and the polyimide fixing edge 8 is arranged along the copolymer film piezoelectric sheet 7, with no overlapping parts on the two sides that are close to each other.

[0093] A floating ground wire 14 is also connected to the electrode line in the lower electrode layer 5. The circular electrode 9 at the corner of the lower electrode layer 5 is connected to an output electrode 13, which is connected to an external device such as a signal generator or oscilloscope.

[0094] An isolation block 11 is provided between two vertically aligned electrode lines in electrode layers 3 and 5.

[0095] The upper encapsulation layer 1 and the lower encapsulation layer 6 define the main body shape of the flexible positioner as an "L" shape. The encapsulation block can rotate around the hinge so that the entire flexible positioner can be folded along the hinge.

[0096] The circular electrodes 9 on the Y and Z surfaces of the upper electrode layer 3 are each led out by an electrode line, while all the circular electrodes 9 on the lower electrode layer 5 are led out by a common electrode line.

[0097] A hinge structure is designed at the connection between the upper encapsulation layer 1 and the lower encapsulation layer 6, which can greatly optimize the internal stress when the degree of bending is large.

[0098] Polyimide has a certain absorption capacity for ultrasound, which can reduce interference between ultrasound waves excited by adjacent working surfaces and adjacent piezoelectric units. To ensure the excitation effect of each piezoelectric unit, the copolymer film piezoelectric sheet requires silver plating on both the upper and lower surfaces.

[0099] The locator comes in two forms: planar and three-dimensional. The locator mainly consists of an "L"-shaped structure composed of a first folding block, a second folding block, and a third folding block. The second and third folding blocks are located on both sides of the first folding block and are movably connected to the first folding block via hinges. In the planar form, the first, second, and third folding blocks of the locator are connected to form a foldable planar whole, with the hinge serving as the folding edge of the locator. In the three-dimensional form, the locator is formed by folding the planar whole along the folding edge, with the first folding block located at the corner of the locator and the second and third folding blocks located at both ends of the locator.

[0100] The specific detection process of this invention is as follows:

[0101] First, the flexible locator is attached to the surface of any object, and the object to be tested is placed at a distance h from the locator, with the line connecting the object and the locator parallel to the direction of ultrasonic wave propagation emitted by the locator. The time of flight (TOF) of the echo signal reflected by the locator is recorded using a signal generator, and the propagation speed v of the ultrasonic wave is calculated.

[0102] v = 2·h / TOF

[0103] Where TOF is the time difference between the excitation time of the echo signal and the time difference between the voltage signal generated by the echo, and h is the distance between the locator and the object to be detected. If the speed of ultrasonic wave propagation is known, this step can be omitted.

[0104] Step 1: When not in operation, the positioner is in a planar state, such as... Figure 15a As shown, an external robot folds the planar locator along the hinge into a three-dimensional form with three mutually perpendicular folded blocks. This form is taken as the initial three-dimensional form of the locator, i.e., the planes containing the first, second, and third folded blocks are mutually perpendicular. The planes containing the first, second, and third folded blocks are respectively designated as the first plane (X-plane), the second plane (Y-plane), and the third plane (Z-plane). An initial spatial rectangular coordinate system o0x0y0z0 is established for the locator in its initial three-dimensional form.

[0105] like Figure 15bAs shown, the intersection of the first plane X, the second plane Y, and the third plane Z is taken as the initial spatial rectangular coordinate system o0x0y. o The origin O0 of the z0 system, and the initial spatial rectangular coordinate system o0x o The x0, y0, and z0 axes of the y0z0 system are perpendicular to the first plane (X-plane), the second plane (Y-plane), and the third plane (Z-plane), respectively. The locator is located in the initial spatial rectangular coordinate system o0x0y. o The positive directions of the x0, y0, and z0 axes of the z0 system are defined by taking the first plane X as the initial spatial rectangular coordinate system o0x. o y o The yoz plane of the z0 system, the second plane Y plane as the Zox plane of the initial spatial rectangular coordinate system o0x0y0z0 system, and the third plane Z plane as the yox plane of the initial spatial rectangular coordinate system o0x0y0z0 system;

[0106] Step 2: Complete the detection of the first plane, X-plane.

[0107] The signal generator is turned on, causing the ultrasonic sensitive layer 4 in the locator to emit ultrasonic waves. The locator is placed around the object to be detected, and simultaneously rotated around the x0 and z0 axes of the initial spatial rectangular coordinate system o0x0y0z0. When the signal generator detects an echo signal generated on the first plane X, the time difference between the excitation time and the echo time on the first plane X is recorded as the first time of flight (TOF). x Meanwhile, the rotation angles of the positioner around the x0 axis and z0 axis at this time are respectively denoted as the first rotation angle α and the second rotation angle. And through the first rotation angle α and the second rotation angle The affine matrix M1 is obtained as follows:

[0108]

[0109] like Figure 15c As shown, the current shape of the locator is taken as the first three-dimensional shape, and a first spatial rectangular coordinate system o1x1y1z1 is established for the locator in the first three-dimensional shape: the intersection of the first plane X, the second plane Y, and the third plane Z is taken as the origin O1 of the first spatial rectangular coordinate system o1x1y1z1. The x1 axis, y1 axis, and z1 axis of the first spatial rectangular coordinate system o1x1y1z1 are perpendicular to the first plane X, the second plane Y, and the third plane Z, respectively. The locator is located in the positive directions of the x1 axis, y1 axis, and z1 axis of the first spatial rectangular coordinate system o1x1y1z1.

[0110] First rotation angle α and second rotation angle Both vary within the interval (-π / 2, π / 2); where α and From the perspective of the positive direction of the coordinate axis, counterclockwise is the positive value.

[0111] When an ultrasonic wave encounters the object being tested, it is reflected and returns to the X-plane along the same path. Through the piezoelectric effect, the PVDF-TrFE ultrasonic sensitive layer 4 generates a voltage signal. Due to the diffusion of the ultrasonic wave, the echo with a propagation path perpendicular to the main working surface X-plane has the greatest energy and can generate the strongest voltage signal. Upon receiving this signal, the flexible positioner stops moving.

[0112] Step 3: Complete the detection of the second plane, Y-plane.

[0113] Keeping the positions of the first and third folding blocks unchanged, rotate the second folding block of the positioner around the hinge between the first and second folding blocks. When the signal generator detects an echo signal generated on the second plane Y, record the excitation time and echo time difference of the echo signal on the second plane Y at this time as the second time of flight (TOF). Y Meanwhile, the rotation angle of the second folded block at this time is recorded as the first rotation angle θ. Y ;

[0114] θ Y From the perspective of the positive z1 direction, counterclockwise is the positive value.

[0115] like Figure 15d and Figure 16 As shown, the current shape of the locator is then taken as the second three-dimensional shape, and a second spatial rectangular coordinate system o2x2y2z2 is established for the locator in the second three-dimensional shape: the intersection of the first plane X, the second plane Y, and the third plane Z is taken as the origin O2 of the second spatial rectangular coordinate system o2x2y2z2. The x2 axis, y2 axis, and z2 axis of the second spatial rectangular coordinate system o2x2y2z2 are perpendicular to the first plane X, the second plane Y, and the third plane Z, respectively. The locator is located in the positive directions of the x2 axis, y2 axis, and z2 axis of the second spatial rectangular coordinate system o2x2y2z2.

[0116] Step 4: Complete the detection of the third plane Z-plane.

[0117] Keeping the positions of the first and second folding blocks unchanged, rotate the third folding block of the positioner around the hinge between the first and third folding blocks. When the signal generator detects an echo signal generated on the third plane Z-plane, record the excitation time and echo time difference of the echo signal on the third plane Z-plane at this time as the third time of flight (TOF). Z Meanwhile, the rotation angle of the third folded block at this time is recorded as the second rotation angle θ. Z and through the first turning angle θ Y Second turning angle θ Z The transfer matrix M2 is obtained:

[0118]

[0119] Where, θ Z From the perspective of the positive direction of y1, counterclockwise is the positive value.

[0120] Step 5: Locate the object to be detected:

[0121] Obtain the coordinates c2(x) of the object to be detected in the second spatial rectangular coordinate system o2x2y2z2. p y p , z p ):

[0122] x p =v·TOF X / 2

[0123] y p =v·TOF Y / 2

[0124] z p =ν·TOF Z / 2

[0125] Where v is the speed of sound propagation, x p y p , z p These are the coordinates of the object to be detected on the x2 axis, y2 axis, and z2 axis in the second spatial rectangular coordinate system o2x2y2z2.

[0126] Step 5: Obtain the coordinates c0(x, y, z) of the object to be detected in the initial Cartesian coordinate system o0x0y0z0. pp y pp , z pp ):

[0127]

[0128] in:

[0129]

[0130]

[0131] x pp y pp Z pp These are the coordinates of the object to be detected on the x0, y0, and z0 axes, respectively, within the initial spatial rectangular coordinate system o0x0y0z0.

[0132] A method for manufacturing a flexible positioner with adjustable spatial detection range:

[0133] The specific implementation steps of this invention are as follows:

[0134] 1) Prepare resin molds, fixing mechanisms, and electrode printing screen printing plates for each component of the flexible positioner in advance.

[0135] like Figures 10a-10c and Figure 12 As shown, the resin mold includes a resin mold with an upper encapsulation layer 1 having a patterned shape and grooves, and a resin mold with an integral shape of a flexible positioner; as shown... Figure 11 As shown, the fixing mechanism includes a resin mechanism with the polyester fiber sheet 12 and the PVDF-TrFE copolymer film in relative positions; as Figure 9a and Figure 9b As shown, the electrode screen printing plate includes a metal mesh with three rows of lines in the upper electrode layer and a metal mesh with five rows of lines in the lower electrode layer.

[0136] The resin mold and fixing mechanism are manufactured by 3D printing, while the electrode screen printing plate is manufactured by laser cutting.

[0137] 2) Prepare in advance PDMS liquid material, curing agent, silver particle silicone grease, polyester fiber material, PVDF-TrFE copolymer material, PI polyimide material, and silicone rubber material.

[0138] PDMS liquid material and curing agent were mixed at a mass ratio of 10:1 and stirred in a mixer for 3 minutes to obtain PDMS colloidal material.

[0139] Polyester fiber material and PVDF-TrFE copolymer material were cut into square sheets of 4mm×4mm respectively, and PI polyimide material was cut into strips of 4mm×(1~2)mm.

[0140] A square PVDF-TrFE copolymer film was completely immersed in a roughening agent, heated at 60°C for 5 minutes, washed with water, and then neutralized by cleaning in alkali. After soaking in an activator diluted at 15 g: 1 kg for 30 seconds, the film was removed and heated at 40°C until the film surface was completely dry. The film was then immersed in a chemical silver plating solution for 2 minutes, the solution was changed, and the film was soaked again for 10 minutes. It was then rinsed in water and dried at 30°C to obtain a silver-plated copolymer piezoelectric film 7.

[0141] 3) Fabricate the various layered structures of the flexible positioner, including the upper encapsulation layer 1, the polyester fiber backing layer 2, the upper electrode layer 3, the ultrasonic sensitive layer 4, the lower electrode layer 5, and the lower encapsulation layer 6.

[0142] a) Manufacturing the upper encapsulation layer 1 and the lower encapsulation layer 6:

[0143] Apply release agent evenly to the mold surface corresponding to the upper encapsulation layer 1 and the lower encapsulation layer 6 using a spray bottle, and let it stand at room temperature for 10 minutes; pour the PDMS colloidal material obtained in step 2) into the mold corresponding to the upper encapsulation layer 1 and the lower encapsulation layer 6, scrape off the excess with a scraper, heat at 80°C for 2 hours to cure and shape, and open the mold to obtain the upper encapsulation layer 1 and the lower encapsulation layer 6.

[0144] b) Manufacturing polyester fiber backing layer 2:

[0145] Apply a small amount of PDMS colloid material evenly to the groove surface of the obtained upper encapsulation layer 1 with a scraper, attach the polyester fiber fixing mechanism to the obtained upper encapsulation layer 1, ensuring that each side is completely overlapped, and obtain the specific position of each unit of the polyester fiber backing layer 2. Place the polyester fiber square sheet obtained in step 2) into the groove in parallel, heat at 80°C for 10 minutes, and remove the fixing mechanism.

[0146] c) Fabricating the upper electrode layer 3 and the lower electrode layer 5:

[0147] The upper electrode layer 3 and the lower electrode layer 5 are manufactured by screen printing.

[0148] The screen printing plate with the upper electrode layer 3 is attached parallel to the upper encapsulation layer 1, ensuring that each edge is completely overlapped. Silver particle silicone grease is evenly applied to the screen printing plate with a squeegee, ensuring that the gaps in each pattern on the screen printing plate are filled with silver particle silicone grease. After completion, the screen printing plate is removed, and the silver particle silicone grease is heated at 80°C for 2 hours to complete curing.

[0149] The screen printing plate with the lower electrode layer 5 is attached parallel to the lower encapsulation layer 6, ensuring that each edge is completely overlapped. Silver particle silicone grease is evenly applied to the screen printing plate with a squeegee, ensuring that the gaps in each pattern on the screen printing plate are filled with silver particle silicone grease. After completion, the screen printing plate is removed, and the silver particle silicone grease is heated at 80°C for 2 hours to complete curing.

[0150] Apply a small amount of PDMS gel material to the electrode lines of the upper encapsulation layer 1 (with upper electrode layer 3) and the lower encapsulation layer 6 (with lower electrode layer 5) printed on the upper encapsulation layer 3 using a scraper, ensuring that the PDMS gel material can cover the electrode lines and that the circular electrode can be completely exposed, and heat at 80°C for 1 hour.

[0151] d) Fabrication of the ultrasonic sensitive layer 4:

[0152] The PVDF-TrFE copolymer film fixing mechanism is attached to the upper encapsulation layer 1 with the upper electrode layer 3 printed on it obtained in step c), ensuring that each edge of the upper electrode layer 3 is completely overlapped, so as to obtain the relative position of the copolymer film piezoelectric sheet 7. A small amount of adhesive is placed on the circular electrode part of the upper electrode layer 3 with tweezers, and the PVDF-TrFE copolymer film obtained in step 2) is placed parallel to the through hole. The film is left to stand at room temperature for 30 minutes, and then the fixing mechanism is removed.

[0153] like Figure 13 As shown, a small amount of PDMS colloidal material is applied along the edge of each copolymer film piezoelectric sheet 7 using a scraper. The PI polyimide strip obtained in step 2) is placed around each copolymer film piezoelectric sheet 7, ensuring that there is no overlap and that the boundaries are tightly attached. Heat at 80°C for 10 minutes.

[0154] 4) Bond the corresponding layers together with adhesive or PMDS glue to complete the fabrication of the flexible positioner.

[0155] A release agent is evenly sprayed onto the inner surface of the mold with the overall shape of the flexible positioner using a spray bottle, and allowed to stand at room temperature for 10 minutes; the upper encapsulation layer obtained in step 3) is then placed parallel into the mold, as follows. Figure 14 As shown, place isolation blocks around the circular electrode of the upper electrode layer 3, and then place the lower encapsulation layer 6 parallel into the mold, ensuring that the upper encapsulation layer 1 and the groove left at the bottom of the mold are aligned and that the boundaries of the upper encapsulation layer 1 and the lower encapsulation layer 6 are completely overlapped. Place a 10g pressure block above the flexible positioner to ensure that the upper encapsulation layer 1 and the lower encapsulation layer 6 are adhered. Pour PDMS colloidal material along the gap between the mold and the flexible positioner, heat at 80°C for 2 hours, and then remove the mold.

[0156] Complete the packaging and manufacturing of the flexible positioner;

[0157] The parameters of the flexible positioner in the embodiments of the present invention are as follows:

[0158] The thickness of the upper encapsulation layer 1 and the lower encapsulation layer 6 is 1 mm, and the hinge part is an arc with a diameter of 1.17 mm; the thickness of the upper electrode layer 3 and the lower electrode layer 5 is 0.1 mm; the thickness of the ultrasonic sensitive layer 4 is 0.038 mm; and the thickness of the polyester fiber backing layer 2 is 1 mm.

[0159] Each working surface of the flexible positioner is a square with a side length of 20mm, and a 1mm margin is left between each working surface. That is, the upper encapsulation layer 1 and the lower encapsulation layer 6 are "L"-shaped, with each side being 21mm long. In the upper electrode layer 3 and the lower electrode layer 5, the electrode lines 10 are 0.5mm wide, 0.5mm apart, and 0.1mm high; the radius of the circular electrode 9 is 1mm; the shape and size of the isolation block are variable, and the size is smaller than the width of the electrode lines; the polyester fiber sheet 12 is a square with a side length of 4mm and a thickness of 1mm; the copolymer film piezoelectric sheet 7 is a square with a side length of 4mm and a thickness of 0.038mm; the polyimide fixing edge 8 is a rectangle with a length of 4mm, a width of 1mm, and a thickness of 1mm.

[0160] The above-described specific embodiments are used to explain and illustrate the present invention, and are not intended to limit the present invention. Any modifications and changes made to the present invention within the spirit and scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A flexible positioner with an adjustable spatial detection range, characterized in that: It is composed of an upper encapsulation layer (1), an upper electrode layer (3), an ultrasonic sensitive layer (4), a lower electrode layer (5) and a lower encapsulation layer (6) stacked from top to bottom. The polyester fiber backing layer (2) is embedded in the lower part of the upper encapsulation layer (1), and the lower surface of the polyester fiber backing layer (2) is flush with the lower surface of the upper encapsulation layer (1). The lower electrode layer (5) is connected to a signal generator. The L-shaped locator is used to locate the object to be detected. The ultrasonic waves emitted by the locator will be reflected when they encounter the object to be detected. By adjusting the position and shape of the locator, the position information of the object to be detected can be obtained. The locator has two forms: planar and three-dimensional. The locator is an "L"-shaped structure composed of a first folding block, a second folding block, and a third folding block. The second and third folding blocks are located on both sides of the first folding block and are movably connected to the first folding block through hinges. In the planar form, the first, second, and third folding blocks of the locator are connected to form a foldable planar whole, with the hinge serving as the folding edge of the locator. In the three-dimensional form, the locator is formed by folding the planar whole along the folding edge.

2. The flexible positioner with adjustable spatial detection range according to claim 1, characterized in that: The lower part of the upper encapsulation layer (1) is provided with several rectangular grooves. The polyester fiber backing layer (2) is formed by several polyester fiber sheets (12) arranged in an L-shaped array. Each polyester fiber sheet (12) is embedded in the rectangular groove of the upper encapsulation layer (1). The ultrasonic sensitive layer (4) is formed by several piezoelectric units arranged in an L-shaped array. The number and arrangement of the polyester fiber sheets (12) in the polyester fiber backing layer (2) and the piezoelectric units in the ultrasonic sensitive layer (4) are the same and aligned. Both the upper electrode layer (3) and the lower electrode layer (5) are composed of several circular electrodes (9). The circular electrodes (9) in the upper electrode layer (3) and the lower electrode layer (5) are connected by electrode lines. The number and arrangement of the circular electrodes (9) in the upper electrode layer (3) and the circular electrodes (9) in the lower electrode layer (5) are the same and aligned. The circular electrodes (9) in the upper electrode layer (3) and the circular electrodes (9) in the lower electrode layer (5) are respectively located on both sides of the piezoelectric unit.

3. A flexible positioner with adjustable spatial detection range according to claim 2, characterized in that: The upper encapsulation layer (1) is an "L"-shaped structure composed of a first encapsulation block, a second encapsulation block and a third encapsulation block. The second encapsulation block and the third encapsulation block are located on both sides of the first encapsulation block, and the second encapsulation block and the third encapsulation block are movably connected to the first encapsulation block through hinges. The lower encapsulation layer (6) is an "L"-shaped structure composed of a fourth encapsulation block, a fifth encapsulation block and a sixth encapsulation block. The fifth encapsulation block and the sixth encapsulation block are located on both sides of the fourth encapsulation block, and the fifth encapsulation block and the sixth encapsulation block are movably connected to the fourth encapsulation block through hinges. The first, second, and third encapsulation blocks are arranged in the same and aligned positions as the fourth, fifth, and sixth encapsulation blocks, respectively.

4. A flexible positioner with adjustable spatial detection range according to claim 2, characterized in that: The piezoelectric unit includes a copolymer film piezoelectric sheet (7) and a polyimide fixing edge (8). Four polyimide fixing edges (8) are fixedly connected around the polyimide fixing edge (8). The number and arrangement of the copolymer film piezoelectric sheet (7) and the polyester fiber sheet (12) are the same and aligned. The upper and lower surfaces of the copolymer film piezoelectric sheet (7) are plated with silver.

5. A flexible positioner with adjustable spatial detection range according to claim 2, characterized in that: The electrode line in the lower electrode layer (5) is also connected to a suspended ground wire (14), and the circular electrode (9) at the corner of the lower electrode layer (5) is connected to a lead-out electrode (13), which is connected to an external signal generator.

6. A method for detecting a flexible positioner according to any one of claims 1-5, characterized in that, Includes the following steps: Step 1: Using an external robot, the planar locator is folded along the hinge into a three-dimensional form with three perpendicular folded blocks. This form is taken as the initial three-dimensional form of the locator. The planes containing the first, second, and third folded blocks are respectively designated as the first plane (X-plane), the second plane (Y-plane), and the third plane (Z-plane). An initial spatial rectangular coordinate system o0x0y0z0 is established for the locator in its initial three-dimensional form. The intersection of the first plane (X-plane), the second plane (Y-plane), and the third plane (Z-plane) is taken as the origin O0 of the initial spatial rectangular coordinate system o0x0y0z0. The x0, y0, and z0 axes of the initial spatial rectangular coordinate system o0x0y0z0 are perpendicular to the first plane (X-plane), the second plane (Y-plane), and the third plane (Z-plane), respectively. The locator is located in the positive directions of the x0, y0, and z0 axes of the initial spatial rectangular coordinate system o0x0y0z0. Step 2: Complete the detection of the first plane, X-plane. Turn on the signal generator to make the locator emit ultrasonic waves, place the locator around the object to be detected, and rotate the locator sequentially around the x0 axis and z0 axis of the initial spatial rectangular coordinate system o0x0y0z0. When the signal generator detects an echo signal generated on the first plane X, record the time difference between the excitation time and the echo time of the first plane X as the first time of flight (TOF). X ; Step 3: Complete the detection of the second plane, Y-plane. The second folding block of the positioner is rotated around the hinge between the first and second folding blocks. When the signal generator detects an echo signal generated on the second plane Y, the difference between the excitation time and the echo time of the echo signal on the second plane Y at this time is recorded as the second time of flight (TOF). Y ; Then, the current shape of the locator is taken as the second three-dimensional shape, and a second spatial rectangular coordinate system o2x2y2z2 is established for the locator in the second three-dimensional shape: the intersection of the first plane X, the second plane Y, and the third plane Z is taken as the origin O2 of the second spatial rectangular coordinate system o2x2y2z2. The x2 axis, y2 axis, and z2 axis of the second spatial rectangular coordinate system o2x2y2z2 are perpendicular to the first plane X, the second plane Y, and the third plane Z, respectively. The locator is located in the positive directions of the x2 axis, y2 axis, and z2 axis of the second spatial rectangular coordinate system o2x2y2z2. Step 4: Complete the detection of the third plane Z-plane. The third folding block of the positioner is rotated around the hinge between the first and third folding blocks. When the signal generator detects an echo signal generated on the third plane Z-plane, the difference between the excitation time and the echo time of the echo signal on the third plane Z-plane at this time is recorded as the third time of flight (TOF). Z ; Step 5: Locate the object to be detected: Obtain the coordinates c2(x) of the object to be detected in the second spatial rectangular coordinate system o2x2y2z2. p y p , z p ): x p =ν·TOF X / 2 y p =ν·TOF Y / 2 With p =ν TOF Z / 2 Where is the speed of propagation of ultrasound, x p y p , z p These are the coordinates of the object to be detected on the x2 axis, y2 axis, and z2 axis in the second spatial rectangular coordinate system o2x2y2z2.

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