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CN-224231142-U - Three-dimensional force sensor with high spatial resolution, electronic skin and robot

CN224231142UCN 224231142 UCN224231142 UCN 224231142UCN-224231142-U

Abstract

The utility model relates to a three-dimensional force sensor with high spatial resolution, an electronic skin and a robot, which comprises a measuring branch, a processing module, a switch array and sensing units, wherein the sensing unit is provided with a flexible body, a three-dimensional force detection assembly which is used as a minimum mechanical sensing unit and generates light intensity, magnetic flux, resistance or capacitance change by stress deformation is arranged in an area contained by the flexible body, the flexible body of each sensing unit is distributed with at least two measuring points, the measuring points are distributed to form a sensing array of the sensing unit and are used for detecting the spatial position of a stress acting point of the flexible body of the corresponding sensing unit, the measuring branch is coupled with the three-dimensional force detection assembly to acquire first type detection data, and each measuring point is respectively coupled with the switch array to acquire second type detection data, and the processing module is coupled with the measuring branch and outputs a three-dimensional force signal according to the first type detection data and a spatial resolution signal according to the second type detection data.

Inventors

  • SUN TENGCHEN
  • ZHANG DAHUA
  • ZENG FANYOU

Assignees

  • 北京他山科技有限公司

Dates

Publication Date
20260512
Application Date
20250530

Claims (18)

  1. 1. A three-dimensional force sensor with high spatial resolution, characterized by: the device comprises a measuring branch, a processing module, a switch array and at least one sensing unit; Each sensing unit is provided with a flexible body for contacting an external object, a three-dimensional force detection assembly for generating light intensity, magnetic flux, resistance or capacitance change by stress deformation is arranged in an area contained by the flexible body, and the three-dimensional force detection assembly is used as a minimum mechanical sensing unit in the sensor for independently detecting three-dimensional force; Each flexible body of each sensing unit is distributed with at least two measuring points, each measuring point is arranged at different positions of the corresponding flexible body to form a sensing array of the sensing unit, and each measuring point in the sensing array is used for detecting the spatial position of the stress acting point of the corresponding flexible body of the sensing unit; The measuring branch is coupled with the three-dimensional force detection component to obtain first-class detection data, and each measuring point is respectively coupled with the switch array to obtain second-class detection data; The processing module is coupled with the measuring branch and is used for outputting a three-dimensional force signal according to the first type of detection data and outputting a spatial resolution signal according to the second type of detection data.
  2. 2. The three-dimensional force sensor of claim 1, wherein: Each measuring point comprises a first electrode and a second electrode which are arranged above each other, and the projection of the first electrode relative to the second electrode at least covers part of the area of the second electrode; The measuring branch circuit comprises a capacitance-to-digital conversion circuit, the capacitance-to-digital conversion circuit is respectively coupled with the first electrode and the second electrode of each point location through a switch array and is used for acquiring the mutual capacitance between the first electrode and the second electrode on each point location, and the first electrode and the second electrode are used as capacitance sensing electrodes.
  3. 3. The three-dimensional force sensor of claim 1, wherein: Each measuring point is provided with a piezoelectric material, a first electrode and a second electrode which are respectively arranged on the upper surface and the lower surface of the piezoelectric material, the piezoelectric material between the measuring points is integrated or split, and the first electrode and the second electrode are used as signal output electrodes of the piezoelectric material of corresponding points; The measuring branch circuit comprises a piezoelectric measuring circuit, the piezoelectric measuring circuit is respectively coupled with the first electrode and the second electrode of each point location through a switch array and is used for acquiring an electric signal between the first electrode and the second electrode on each point location, and the piezoelectric measuring circuit comprises a charge amplifier and is used for amplifying the electric signal.
  4. 4. A three-dimensional force sensor according to claim 3, characterized in that: The projection of the first electrode relative to the second electrode covers at least a partial area of the second electrode; The measuring branch circuit comprises a capacitance-to-digital conversion circuit, the capacitance-to-digital conversion circuit is respectively coupled with a first electrode and a second electrode of each point location through a switch array and is used for acquiring mutual capacitance between the first electrode and the second electrode on each point location, and the first electrode and the second electrode are used as multiplexing electrodes of a capacitance sensing electrode and a signal output electrode of a piezoelectric material.
  5. 5. The three-dimensional force sensor of any of claims 1-4, wherein: Each measuring point at least comprises a first electrode, the measuring branch comprises a capacitance-digital conversion circuit, the capacitance-digital conversion circuit is respectively coupled with the first electrode of each point location through a switch array and is used for acquiring the self capacitance of the first electrode and/or the mutual capacitance of the first electrode between the two point locations, and the first electrode is at least used as a proximity detection electrode.
  6. 6. The three-dimensional force sensor of claim 1, wherein: Each measuring point is provided with a piezoresistive material, the piezoresistive material of each measuring point is correspondingly provided with a first electrode and a second electrode, the first electrode and the second electrode are respectively arranged on the upper surface and the lower surface of the piezoresistive material, and the first electrode and the second electrode are used as signal output electrodes of the piezoresistive material of corresponding points; The measuring branch circuit comprises a piezoresistance measuring circuit, wherein the piezoresistance measuring circuit is respectively coupled with the first electrode and the second electrode of each point location through a switch array and is used for acquiring an electric signal between the first electrode and the second electrode on each point location when an object is contacted.
  7. 7. The three-dimensional force sensor of claim 1, wherein: Each measuring point is provided with a piezoresistive material, the piezoresistive material of each measuring point is correspondingly provided with a first electrode and a second electrode, the first electrode and the second electrode are arranged on the piezoresistive material in a coplanar manner, and the first electrode and the second electrode are used as signal output electrodes of the piezoresistive material of corresponding points; The measuring branch circuit comprises a piezoresistance measuring circuit, wherein the piezoresistance measuring circuit is respectively coupled with the first electrode and the second electrode of each point location through a switch array and is used for acquiring an electric signal between the first electrode and the second electrode on each point location when an object is contacted.
  8. 8. The three-dimensional force sensor of claim 6 or 7, wherein: the piezoresistive material between each measuring point or between the collecting areas formed by a plurality of measuring points forms an insulating interval separately; The second electrode is used as the near-ground end of the measuring point, and a gating switch is connected in series between the second electrode and the ground; The measuring branch circuit comprises a capacitance-digital conversion circuit, the capacitance-digital conversion circuit is respectively coupled with the first electrode of each point location through a switch array and is used for acquiring the self capacitance of the first electrode and/or the mutual capacitance between two mutually insulated first electrodes when an object approaches, and the first electrodes are used as approach detection electrodes.
  9. 9. The three-dimensional force sensor of claim 2, 3 or 4, wherein: the first electrodes of the measuring points are point electrodes, the point electrodes are arranged into an array, the second electrodes of the measuring points are integrated into a whole common electrode, and the point electrodes are positioned above the common electrode.
  10. 10. The three-dimensional force sensor of claim 9, wherein: The three-dimensional force detection component is used for detecting three-dimensional force based on capacitance; the second electrode is used as a multiplexing electrode of a common electrode for contact detection and a shielding electrode of the three-dimensional force detection assembly.
  11. 11. The three-dimensional force sensor of claim 2, 3, 4, 6 or 7, wherein: the first electrode and the second electrode of each measuring point are point electrodes, and the point electrodes in the same layer are arranged into an array.
  12. 12. The three-dimensional force sensor of claim 2 or 6, wherein: The first electrodes and the second electrodes are strip electrodes, the first electrodes are arranged at a certain interval along the transverse direction, the second electrodes are arranged at a certain interval along the longitudinal direction, so that a determinant staggered lattice is formed in the vertical projection direction, and the staggered position is used as the measuring point.
  13. 13. The three-dimensional force sensor of claims 1, 2, 3, 4, 6, or 7, wherein: The inner side of the flexible body is provided with a flexible structure protruding downwards, and the surface of the flexible structure is a curved surface; the flexible body is driven by external force to change the curved surface of the flexible structure to change the light intensity, the magnetic flux, the resistance or the capacitance.
  14. 14. The three-dimensional force sensor of claim 13, wherein: The three-dimensional force detection assembly comprises a magnetic source for actively generating a magnetic field and at least three magnetic field measurement electronic elements, wherein the magnetic source is embedded in the flexible structure, each magnetic field measurement electronic element is arranged below the flexible structure and distributed on the periphery of the flexible structure, the magnetic field measurement electronic elements are directly or indirectly contacted with the curved surface of the flexible structure, and the flexible body is deformed by external force to drive the curved surface of the flexible structure to change the direct or indirect contact area with the magnetic field measurement electronic elements; The measuring branch comprises an analog-to-digital conversion circuit, and the processing module is coupled with each magnetic field measuring electronic element through the analog-to-digital conversion circuit and is used for outputting a three-dimensional force signal according to the magnetic flux of the magnetic field measuring electronic element changed by the deformation of the flexible structure.
  15. 15. The three-dimensional force sensor of claim 13, wherein: The flexible body comprises a region which is a light sealing region, and the flexible body is used as a part of boundary of the light sealing region; The three-dimensional force detection assembly comprises the flexible structure protruding downwards from the inner side of the flexible body, a light emergent channel positioned in a light-sealing area below the flexible structure, and at least three photosensitive electronic elements positioned in the light-sealing area and used for receiving light reflected by the flexible structure; The flexible structure is made of opaque materials, each photosensitive electronic element is distributed on the periphery of the flexible structure, the light-emitting channel is used for emitting light rays emitted to the flexible structure through the light source, and the flexible structure deforms under external force pressing to change the shielding area of the light rays passing through the light-emitting channel; the measuring branch circuit comprises an analog-to-digital conversion circuit, and the processing module is coupled with each photosensitive electronic element through the analog-to-digital conversion circuit and is used for outputting and outputting a three-dimensional force signal according to the condition of reflected light changed by deformation of the flexible structure.
  16. 16. The three-dimensional force sensor of claim 13, wherein: the three-dimensional force detection assembly comprises an upper electrode arranged on the flexible structure and at least three lower electrodes positioned below the upper electrode; the upper electrode is a curved elastic electrode, an insulating layer is arranged between the upper electrode and the lower electrode, each lower electrode is distributed on the periphery of the flexible structure, downward projection of the upper electrode at least covers part of the area of each lower electrode, and the flexible multifunctional layer is deformed by external force to drive the upper electrode to change the indirect contact area with the insulating layer; The measuring branch circuit comprises a capacitance-to-digital conversion circuit, wherein the capacitance-to-digital conversion circuit is respectively coupled with the upper electrode and each lower electrode and is used for acquiring capacitance between the upper electrode and each lower electrode; The processing module is coupled with the capacitance-digital conversion circuit and is used for outputting a three-dimensional force signal according to the capacitance between the upper electrode and each lower electrode, which is changed by the deformation of the flexible structure.
  17. 17. An electronic skin comprising a three-dimensional force sensor with high spatial resolution according to any of claims 1-16.
  18. 18. A robot comprising the electronic skin of claim 17.

Description

Three-dimensional force sensor with high spatial resolution, electronic skin and robot Technical Field The utility model relates to robot touch perception, in particular to a three-dimensional force sensor with high spatial resolution, electronic skin and a robot. Background In a real environment, the contact force between an object and a robot is usually from multiple directions such as pressing, shearing and the like, and the touch of the robot requires three-dimensional force detection to comprehensively reflect the interaction state. Currently, three-dimensional force sensing units or three-dimensional force detection components for realizing the surface touch of a robot have capacitance, piezoresistance, photoelectricity, electromagnetism, multiple modes and the like, and each three-dimensional force sensing unit is the smallest unit with the capability of independently measuring three-dimensional force. In order to meet the high spatial resolution requirement of the surface touch of the robot, the current mainstream is generally striving to make the minimum unit effort smaller and smaller, and a denser lattice is formed by arranging a plurality of units, so that the perceived spatial resolution is improved. CN103743503B discloses a flexible three-dimensional force touch sensor, a plurality of three-dimensional force sensing units are arranged to form a sensing array, each three-dimensional force sensing unit is simultaneously integrated with a vertically arranged force sensing strain gauge and four groups of vertically arranged sensing capacitors, and the sensing array is respectively sensitive to vertical normal force and horizontal tangential force. CN110082010a discloses a flexible tactile sensor array, each three-dimensional force-sensitive unit is realized by four piezoresistive mating projections, and each three-dimensional force-sensitive unit is arranged to form an array. CN117030070a discloses a flexible array touch sensor, each three-dimensional force sensitive unit is formed by an upper electrode and four lower electrodes, and a plurality of sensing units form an array. CN216206640U discloses a composite flexible sensing array, the hemisphere is matched with the four pressure sensors below to form three-dimensional force sensing units, and each three-dimensional force sensing unit forms an array. The touch sensor (see CN 209820667U) proposed previously by my driver adopts the same thought as that the flexible hemispherical protrusions are used as upper electrodes and matched with the lower four lower electrodes to form the minimum three-dimensional force sensing units, and the three-dimensional force sensing units form an array. Although the method has been significantly advanced along with the miniaturization of the three-dimensional force sensing units, the spatial resolution of the tactile array (i.e. the minimum unit number capable of independently sensing the three-dimensional force in a unit area) is limited by technology, physical principles and multiple contradictions of practical application, and the ideal level is still difficult to reach, wherein key factors include that when the size of the force sensing units is reduced to millimeter or even micrometer level, the rigidity of a mechanical structure is increased, deformation signals of micro force are weakened, the signal to noise ratio is reduced, after the three-dimensional force sensing units are miniaturized, the mechanical coupling effect in adjacent directions is enhanced to cause unexpected deformation, and physical limitations of materials and manufacturing are met. Disclosure of utility model In order to overcome the defects in the prior art, a three-dimensional force sensor is provided. The three-dimensional force sensor comprises a measuring branch, a processing module, a switch array and at least one sensing unit, wherein each sensing unit is provided with a flexible body used for contacting an external object, a three-dimensional force detection assembly used for generating light intensity, magnetic flux, resistance or capacitance changes through stress deformation is arranged in an area contained by the flexible body, the three-dimensional force detection assembly is used as a minimum mechanical sensing unit in a sensor and used for independently detecting three-dimensional force, at least two measuring points are distributed on the flexible body of each sensing unit, each measuring point is arranged at different positions of the corresponding flexible body to form a sensing array of the sensing unit, each measuring point in the sensing array is used for detecting the spatial position of a stress acting point of the flexible body of the corresponding sensing unit, the measuring branch is coupled with the three-dimensional force detection assembly to acquire first type detection data, and is respectively coupled with each measuring point through the switch array to acquire second type detection data, and the processi