Mechanical positioning perception sensor

Abstract

The application discloses a mechanical positioning and sensing sensor, which comprises a signal receiving device, a base and a plurality of conversion elements, the signal receiving device and the base are provided with the conversion elements which are distributed in a circumferential array, the side surface of the conversion element is provided with an arc-shaped cut seam and a vertical cut groove which are communicated with each other, and a strain gauge is arranged on the arc-shaped cut seam. The conversion element is of a hollow structure and comprises a plane one, a plane two and a curved surface, the plane one and the plane two are perpendicular to each other, and the two ends of the curved surface are smoothly and transitionally connected with the plane one and the plane two respectively. Preferably, the conversion element is made of nylon which is an elastic material with certain rigidity. The application amplifies a weak signal by using the stress concentration effect at the slit and combines a high-sensitivity strain gauge, thereby realizing acute detection of a small mechanical quantity and solving the problems of a large volume and low sensitivity of an existing positioning sensor. The unique cylindrical surface conversion element array design endows the sensor with natural omnidirectional sensing capability, and high-precision direction positioning is realized by using array signal analysis.

Description

Technical Field

[0001] This invention pertains to positioning sensors, specifically a mechanical positioning sensing sensor. Background Technology

[0002] In nature, many arthropods possess extremely keen mechanosensory abilities. For example, scorpions possess a special type of "slit receptor" in their legs, capable of sensing weak matrix vibrations and using an array of slits distributed at different locations or angles on their legs to accurately determine the direction and location of prey. Existing mechanosensory sensors often rely on complex microphone arrays or multi-axis accelerometer combinations, which suffer from problems such as large size, complex signal processing, and insufficient response to weak signals. Although high-sensitivity pressure sensors utilizing the crack effect already exist, current biomimetic sensor designs mostly focus on single-point force measurement or wide-range measurement, lacking effective design schemes for spatial orientation sensing using cylindrical array structures, resulting in large size and low sensitivity. Therefore, how to combine the ultrasensitive mechanism of biological slit receptors with arrayed positioning algorithms to design a compact sensor capable of precise positioning is a pressing technical problem that needs to be solved. Summary of the Invention

[0003] Purpose of the invention: In order to overcome the shortcomings of the existing technology, the purpose of this invention is to provide a mechanical positioning sensing sensor based on a biological suture array that achieves high-sensitivity vibration detection and vibration source localization sensing.

[0004] Technical solution: The mechanical positioning sensing sensor of the present invention includes a signal receiving device, a base and several conversion elements, wherein the conversion elements are arranged in a circumferential array between the signal receiving device and the base; the sides of the conversion elements are provided with interconnected arc-shaped slits and vertical grooves, and strain gauges are arranged on the arc-shaped slits.

[0005] The main function of the signal receiving device is to act as a contact surface to receive external mechanical vibrations or contact pressures and to uniformly transmit these mechanical signals to multiple conversion elements below. In addition, the signal receiving device also serves as a dustproof protection and provides structural constraints. The base supports the entire sensor structure and provides an interface for mounting external equipment (such as robotic arms or testing platforms).

[0006] Furthermore, the conversion element is a hollow structure, comprising a first plane, a second plane, and a curved surface. The first plane and the second plane are perpendicular to each other, and the two ends of the curved surface are smoothly connected to the first plane and the second plane, respectively. Preferably, the conversion element is made of nylon, an elastic material with a certain stiffness.

[0007] Furthermore, the angle between the vertical cut and plane one is 10°~15°. An angle greater than 15° will usually reduce the effective length of the arc cut; an angle less than 10° will change the span of the arc cut in the circumferential direction.

[0008] Furthermore, the curved surfaces are pieced together to form a hollow cylinder. Multiple identical conversion elements are arranged in a ring array, giving it 360° omnidirectional sensing capability.

[0009] Furthermore, the cross-section of the vertical groove is trapezoidal, and the depth of the vertical groove is 1 / 2 to 2 / 3 of the height of the conversion element.

[0010] Furthermore, the arc-shaped slit gradually approaches the signal receiving device from the direction away from the vertical groove, with a width of 1-2 mm. The vertical groove and the arc-shaped slit form an elastic deformation zone similar to a cantilever beam at the top of the conversion element. This structural design simulates the mechanical mechanism of the slit-like receptors on a scorpion's leg, effectively converting minute external pressures or vibrations into changes in the slit width. The arc-shaped slit on the conversion element utilizes fracture mechanics principles to generate stress concentration, amplifying minute mechanical vibrations into observable displacements at the slit edge. Using a gold-plated PDMS thin film as a strain gauge, combined with the elastic properties of nylon material, significantly improves the quality of the sensor's electrical signal output.

[0011] Furthermore, the arc-shaped kerf satisfies the following relationship:

[0012] Where (x, y, z) are the coordinates of a point on the cut line, and t is a parameter variable. The size of the arc-shaped slit and the vertical groove will affect the sensing performance. Changes in the size of the slit will affect the range of the sensing force. The larger the slit, the greater the force that can be sensed, but if the force is too great, it will cause the slit to be damaged.

[0013] Furthermore, the strain gauge comprises a cracked PDMS layer and a conductive layer, the conductive layer being fabricated by spraying metal onto the cracked PDMS layer. When the slit undergoes a micrometer-level "opening and closing" motion due to force, the strain gauge undergoes tensile or compressive deformation, which in turn causes a change in its resistance or charge, converting the mechanical deformation signal into an electrical signal output.

[0014] Preferably, the conductive layer is a gold layer.

[0015] Furthermore, the strain gauge is connected to the signal processing unit, which calculates the azimuth angle of the vibration source by comparing the relative amplitudes of the strain gauges.

[0016] Detection Principle: When external vibration or impact signals are transmitted to the sensor through the base or signal receiving device, due to the directional nature of wave propagation, the arc-shaped slits and vertical grooves on the sides of the conversion element located at different orientations will produce varying degrees of opening and closing deformation. The slit structure (arc-shaped slit) can generate a stress concentration effect, amplifying minute mechanical vibrations into displacement changes at the slit edge, which can then be detected by strain gauges spanning the slit. When the vibration source is located at a specific angle, the arc-shaped slit directly opposite or to the side of the vibration source experiences the greatest degree of compression or stretching, while the vertical groove perpendicular to it experiences less deformation. By comparing the amplitude and phase difference of the output electrical signals from different channels in the array, the azimuth angle of the vibration source can be determined using vector synthesis or differential algorithms, achieving location sensing.

[0017] Beneficial effects: Compared with the prior art, the present invention has the following significant features:

[0018] 1. By utilizing the stress concentration effect at the slit to amplify weak signals and combining them with a high-sensitivity strain gauge, the system achieves sensitive detection of minute mechanical quantities, which can solve the problems of large size and low sensitivity of existing positioning sensors.

[0019] 2. It is endowed with natural omnidirectional sensing capability through a unique cylindrical surface conversion element array design, and high-precision orientation positioning is achieved by using array signal analysis;

[0020] 3. The design that integrates the sensing element with the main structure significantly reduces the size, making it more compact than traditional discrete arrays and easy to integrate into robots or monitoring equipment. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention;

[0022] Figure 2 This is a front view of the conversion element in this invention;

[0023] Figure 3 This is an enlarged view of the slit functional unit in this invention.

[0024] Figure 4 This is a schematic diagram of the crack strain gauge in this invention. Detailed Implementation

[0025] like Figure 1The bio-slit array-based mechanical positioning sensor has a cylindrical structure, consisting of a signal receiving device 1, a base 2, and a ring array of four conversion elements 3 located between them. The four conversion elements 3 are evenly distributed along the circumference, collectively forming the core mechanical sensing component of the sensor. The signal receiving device 1 is a disc-shaped structure that covers and is fixedly connected to the top of the four conversion elements 3. Its main function is to act as a contact surface to receive external mechanical vibrations or contact pressures and to evenly transmit these mechanical signals to the four conversion elements 3 below. It also provides dust protection and structural constraint. The base 2 is a disc-shaped structure, and the bottom ends of the four conversion elements 3 are fixedly mounted on the base 2. The base 2 supports the entire sensor structure and provides an interface for mounting external equipment (such as a robotic arm or testing platform).

[0026] like Figures 2-3 The four conversion elements 3 are structurally identical, each being a 90° fan-shaped hollow columnar structure. These four conversion elements are arranged in a ring array, forming a complete hollow cylinder. The conversion element 3 is primarily made of PA12 GF nylon and includes a first plane 31, a second plane 32, and a curved surface 33. The first plane 31 and the second plane 32 are perpendicular to each other, and the two ends of the curved surface 33 smoothly transition to the first plane 31 and the second plane 32, respectively. The four curved surfaces 33 are assembled to form a hollow cylinder. A specific slit structure is formed on the curved surface 33 of the conversion element 3. This slit structure consists of a horizontal arc-shaped slit 301 and a vertical groove 302, thus creating an elastic deformation zone at the top of the conversion element 3, similar to a cantilever beam. This structural design simulates the mechanical mechanism of the slit-like receptors in a scorpion's leg, effectively converting minute external pressures or vibrations into changes in the slit width. The vertical groove 302 has a trapezoidal cross-section. Two sides of the vertical groove 302 coincide with the conversion element 3, the bottom edge is horizontal, and the top edge forms a 25-degree angle with the bottom edge, forming a quadrilateral. It is stretched downwards and removed by 18mm. The angle between the vertical groove 302 and the plane 31 is 10°~15°, and the height of the conversion element 3 is 30mm. The arc-shaped slit 301 is obtained by stretching and removing 0.18 turns of a rectangle with a length of 1.5mm and a width of 1mm along a spiral with a pitch of 14.5mm and a diameter of 30mm, with an initial angle of 105 degrees. The arc-shaped slit 301 gradually approaches the signal receiving device 1 in a direction away from the vertical groove 302, and the arc-shaped slit 301 satisfies the following relationship:

[0027] .

[0028] Where (x, y, z) are the coordinates of a point on the cut line, and t is a parameter variable. .

[0029] The two ends of strain gauge 4 are fixed to the upper and lower sides of the arc-shaped slit 301, respectively, as follows: Figure 4The strain gauge 4 employs a high-sensitivity surface-sprayed gold PDMS thin film to form a PDMS layer 41 and a conductive layer 42, with the conductive layer 42 being a gold layer. When the arc-shaped slit 301 undergoes a micrometer-level "opening and closing" movement due to force, the strain gauge 4 experiences tensile or compressive deformation, resulting in changes in its resistance or charge, converting the mechanical deformation signal into an electrical signal output. The strain gauge 4 is connected to a signal processing unit, which calculates the azimuth angle of the vibration source by comparing the relative amplitude of the strain gauge 4.

[0030] The mechanical positioning sensing sensor in this embodiment realizes the sensing of the vibration source's orientation: when the signal receiving device 1 receives an external impact or vibration from a specific direction, the force signal is transmitted from the top to the array of conversion elements 3 below. Because the force transmission is directional, the cantilever structure at the top of the conversion element 3 located on the force-bearing side will undergo significant downward bending or compression deformation, resulting in a larger signal response from the strain gauges 4 on it. In contrast, the conversion elements 3 located on the back or side experience different torques, and their arc-shaped slits 301 or vertical grooves 302 deform less, resulting in weaker output signals from the corresponding strain gauges.

[0031] The source of vibration is "calculated" using multiple slits arranged in different directions. By collecting and comparing the amplitude differences and phase relationships of the output signals from four conversion elements 3 and four strain gauges 4, when a mechanical vibration signal (such as footsteps from the ground or abnormal vibration of mechanical equipment) is transmitted to the base 2, the vibration wave propagates upward along the sensing structure. Assuming the vibration source is located in the positive X-axis direction of the sensor: the slit at the conversion element in the X-axis direction will undergo significant deformation due to the compression or bending of the wave, and the resistance value of the strain gauge 4 on it will change significantly, outputting a strong voltage signal. The conversion element 3 located in the Y-axis direction (perpendicular to the wave propagation direction) experiences a different stress mode in its arc-shaped slit 301, resulting in smaller deformation or different phase, and a weaker output signal. The signal processing unit collects signals from four channels (V1, V2, V3, V4), and by comparing the relative amplitudes, the azimuth angle θ of the vibration source can be accurately calculated. Furthermore, the signal receiving device 1 is designed not only as a counterweight to adjust the system's resonant frequency, but also as an omnidirectional receiving antenna to capture sound waves or low-frequency vibrations over a wide range, further enhancing the sensor's application scenarios. Sensitivity reaches 200, and positioning accuracy reaches ±3°.

[0032] Specifically, assuming the mechanical positioning sensor in this embodiment is fixed on the test platform, its four conversion elements 3 are evenly distributed on the circumference, corresponding to spatial azimuth angles of 0°, 90°, 180°, and 270° respectively. When the vibration source is located at 30°, the vibration wave is transmitted to the sensor. Due to spatial geometry, the deformation of each conversion element 3 has a projection relationship with the azimuth angle. The theoretical amplitude (V) collected by its strain gauge 4 can be approximately expressed as the values ​​in Table 1.

[0033] Table 1. Theoretical amplitudes (V) obtained from different strain gauges 4

[0034]

[0035] Azimuth calculation process:

[0036] 1. Constructing differential signals

[0037] To eliminate common-mode noise and extract the direction vector, the difference components of the X and Y axes can be calculated:

[0038] Vx = V1 - V3 = 0.866 - (-0.866) = 1.732

[0039] Vy = V2 - V4 = 0.500 - (-0.500) = 1.000

[0040] Where Vx is the difference component of the X-axis and Vy is the difference component of the Y-axis.

[0041] 2. Calculate the azimuth angle θ

[0042] The source angle can be obtained by inversely solving the arctangent function:

[0043] θ=arctan2(Vy, Vx) =arctan2(1.000, 1.732)=30

[0044] Through the above calculations, the system can accurately detect the direction of the vibration source at 30°. This array design, based on the mechanism of biological slit receptors, utilizes the stress concentration effect at the slit to amplify the signal and, combined with the cylindrical symmetry structure, achieves natural omnidirectional sensing capability.

Claims

1. A mechanical positioning sensing sensor, characterized in that: It includes a signal receiving device (1), a base (2) and several conversion elements (3), with the conversion elements (3) arranged in a circular array between the signal receiving device (1) and the base (2); the sides of the conversion elements (3) are provided with interconnected arc-shaped slits (301) and vertical grooves (302), and strain gauges (4) are provided on the arc-shaped slits (301).

2. The mechanical positioning sensing sensor according to claim 1, characterized in that: The conversion element (3) is a hollow structure, including a plane one (31), a plane two (32) and a curved surface (33). The plane one (31) and the plane two (32) are perpendicular to each other, and the two ends of the curved surface (33) are smoothly connected to the plane one (31) and the plane two (32) respectively.

3. The mechanical positioning sensing sensor according to claim 2, characterized in that: The angle between the vertical groove (302) and the plane (31) is 10°~15°.

4. A mechanical positioning sensing sensor according to claim 1, characterized in that: The curved surfaces (33) are joined together to form a hollow cylinder.

5. A mechanical positioning sensing sensor according to claim 1, characterized in that: The vertical groove (302) has a trapezoidal cross-section, and the depth of the vertical groove (302) is 1 / 2 to 2 / 3 of the height of the conversion element (3).

6. A mechanical positioning sensing sensor according to claim 1, characterized in that: The arc-shaped slit (301) gradually approaches the signal receiving device (1) in a direction away from the vertical slit (302), and has a width of 1~2mm.

7. A mechanical positioning sensing sensor according to claim 1, characterized in that: The arc-shaped cut (301) satisfies the following relationship: Where (x, y, z) are the coordinates of a point on the cut line, and t is a parameter variable. .

8. A mechanical positioning sensing sensor according to claim 1, characterized in that: The strain gauge (4) includes a cracked PDMS layer (41) and a conductive layer (42), the conductive layer (42) being made by spraying metal onto the cracked PDMS layer (41).

9. A mechanical positioning sensing sensor according to claim 8, characterized in that: The conductive layer (42) is a gold layer.

10. A mechanical positioning sensing sensor according to claim 1, characterized in that: The strain gauge (4) is connected to the signal processing unit, which calculates the azimuth angle of the vibration source by comparing the relative amplitude of the strain gauge (4).

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