CN116773063A - Device for measuring contact information and multiaxial force/moment information - Google Patents
Device for measuring contact information and multiaxial force/moment information Download PDFInfo
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Abstract
An embodiment of the present invention provides an apparatus for measuring contact information and multiaxial force/moment information, including: the device comprises a main body frame, a floating working platform, a sensing medium, a reflecting mirror, a visual marking element and an optical sensor; a main body frame; a visual marker element secured to the body frame; a floating work platform elastically connected to the main body frame; the sensing medium is fixed on the floating working platform and is used for acquiring contact information of the surface of the sample to be tested; the reflecting mirror is fixed on the floating working platform and is used for reflecting the image of the visual marking element, and the image can be used for calculating multiaxial force/moment information born by the sensor; and the optical sensor is fixed on the floating working platform and is used for acquiring the contact information and the position information of the image. The invention solves the problem of crosstalk between the contact information and the multiaxial force/moment information, and can directly decouple the two information.
Description
Technical Field
The invention relates to the field of photoelectric measurement, in particular to the field of object surface contact information measurement, and more particularly relates to a device for measuring contact information and multiaxial force/moment information.
Background
The human grasping flexibility is achieved, and the robot is a long-term target of the technology in the robot field. To achieve this goal, reliable tactile and force sensing sensors are essential to robots. Engineering implementations for sensors generally include:
a touch sensor, which is a sensor capable of sensing information such as object contact, force, shape, etc. The tactile sensor may be classified into a contact sensor, a force-moment sensor, a pressure sensor, a slip sensor, etc. according to its function. Common tactile sensors are piezoresistive tactile sensors, photo-sensor type tactile sensors, piezoelectric tactile sensors, capacitive tactile sensors, and the like. In recent years, vision-based tactile sensors (VBTS), such as gel vision sensors and variants thereof, have become an effective means of measuring tactile and force information. The basis of gel vision sensing technology involves reconstructing the deformation of the soft elastomer caused by external objects using the image captured by the embedded camera, and furthermore, normal and shear forces can be deduced from the deformation in addition to the contact geometry.
A multi-axis force/moment sensor, which is a sensor that measures and outputs forces and moments at various coordinates (X, Y, and Z) in a cartesian rectangular coordinate system. The multi-axis force/torque sensor is also referred to as a multi-axis loading unit, an F/T sensor, a tri-or hexa-axis force/torque sensor, etc.
In the prior art, when the requirements of touch sense and multiaxial force/moment measurement under the same working condition are met, technicians often need to carry out a cascading mode on different sensors so as to achieve the technical purpose. The prior art has two technical paths, specifically as follows: one is to directly add a black mark lattice on the surface of the flexible material of the touch sensor, and then approximate the deformation of the mark lattice to the corresponding force distribution. However, the method mainly senses the distribution of force and cannot accurately and effectively measure the net value of the multi-axis force/moment. Another method is to cascade a linear elastic mechanism at the bottom of the flexible material of the touch sensor, add a visual mark on the upper surface of the elastic mechanism to measure the multiaxial pose change of the plane, and map the pose change with the multiaxial force/moment by calibration.
In the process of implementing the inventive concept, the inventor finds that at least the following problems exist in the related art:
due to the cascade mode, when the elastic mechanism is deformed, the bottom plane of the flexible body of the upper touch sensor is deviated, so that the field of view of the flexible body (contact information) in the camera is not constant, and the calibration result of the contact information is influenced. Since the two information are coupled to each other, there is always a crosstalk error both during calibration and during actual measurement. Moreover, because the tactile sensor and the multi-axis force/moment sensor are cascaded, the information is independently acquired and acquired, so that a great deal of extra work is needed to calibrate and synchronize the two sensor data, and extra cost is also increased.
Disclosure of Invention
In view of this, the technical problem to be solved by the present invention is to solve the crosstalk between two kinds of information of the sensor, and to realize effective decoupling of the two kinds of sensor information. The present invention provides an apparatus for measuring contact information extrinsic tactile information and multiaxial force/moment (intrinsic tactile information) information, comprising: the device comprises a main body frame, a floating working platform, a sensing medium, a reflecting mirror, a visual marking element and an optical sensor; the main body frame is used for bearing the integral structure of the device for measuring the contact information and the multiaxial force/moment information and connecting an external clamp; the visual marker element is fixed to the main body frame; the floating working platform is elastically connected to the main body frame; the sensing medium is fixed on the floating working platform and is used for acquiring the contact information of the sample to be tested and feeding back the contact information; the reflecting mirror is fixed on the floating working platform and is used for reflecting the image of the visual marking element, and the image can be used for calculating multiaxial force/moment information born by the sensor; the optical sensor is fixed on the floating working platform and used for acquiring the contact information and the position information of the image.
Embodiments of the present invention provide an apparatus for measuring contact information and multiaxial force/moment information, the sensing medium comprising: an optically transparent elastomer layer, an optically transparent duromer layer; the optical transparent elastomer layer is provided with a first surface and a second surface, wherein the first surface is a working surface for measurement, and an optical coating layer which is reflected towards the inside of the optical transparent elastomer layer and the second surface is arranged inside the first surface; the optically transparent hard body layer is attached to the second surface of the optically transparent elastomeric layer. The working face of the optically transparent elastomer layer is printed with a coating, and the pattern of the layer comprises: printing a marking array and an ultraviolet marking array.
The specific embodiment of the invention provides a device for measuring contact information and multiaxial force/moment information, which further comprises a light supplementing lamp;
and the light supplementing lamp is fixed inside the floating working platform and is used for supplementing light to the sensing medium.
Embodiments of the present invention provide an apparatus for measuring contact information and multiaxial force/moment information, the optical coating having a set reflectivity.
The specific embodiment of the invention provides a device for measuring contact information and multiaxial force/moment information, the optically transparent elastomer layer comprises the following constituent materials: transparent rubber, transparent gel or silica gel.
The specific embodiment of the invention provides a device for measuring contact information and multiaxial force/moment information, wherein the optical transparent hard body layer comprises the following constituent materials: high light transmission glass and acrylic.
Embodiments of the present invention provide an apparatus for measuring contact information and multiaxial force/moment information, the floating work platform being elastically connected to the main body frame;
the elastic connection constrains the spatial degrees of freedom of the floating work platform and the main body frame to include spatial degrees of freedom and rotational degrees of freedom in a Cartesian coordinate system.
The specific embodiment of the invention provides a device for measuring contact information and multiaxial force/moment information, wherein the reflecting mirror is fixed on the floating working platform and is used for reflecting images of the visual marking element;
the reflector is fixed on the floating working platform and is attached to the lower surface of the sensing medium.
Embodiments of the present invention provide an apparatus for measuring contact information and multiaxial force/moment information, the visual marker element being secured to the body frame;
the visual marker element is secured to the interior of the body frame.
The specific embodiment of the invention provides a device for measuring contact information and multiaxial force/moment information, which also comprises a microprocessor;
the microprocessor is connected to the optical sensor and used for acquiring the image signals of the optical sensor. The attitude change quantity of the floating working platform and the main body frame is calculated and obtained through obtaining the attitude change quantity of the marking element in the image of the optical sensor, and then multiaxial force/moment information is calculated and obtained; and obtaining the contact information by calculation through obtaining the image change of the optical image layer.
The specific embodiment of the invention provides a device for measuring contact information and multiaxial force/moment information, which also comprises a wired/wireless communication module;
the wired/wireless communication module is connected to the microprocessor and is used for communicating with external communication equipment.
The specific embodiment of the invention provides a device for measuring contact information and multiaxial force/moment information, which further comprises a power supply unit;
and the power supply unit is connected with the microprocessor and is used for supplying power to the microprocessor, the optical sensor and the light supplementing lamp.
Embodiments of the present invention provide an apparatus for measuring contact information and multiaxial force/moment information, the floating work platform being elastically connected to the main body frame;
The elastic connection comprises the following connection modes: spring, torsion spring, reed, elastic rubber and piezoelectric ceramics.
Embodiments of the present invention provide an apparatus for measuring contact information and multiaxial force/moment information, the visual marker elements including, but not limited to: artoolgit, AR Tag, arUco Tag, april Tag, QR Code, framedge, markers.
The device for measuring the contact information and the multiaxial force/moment information and the implementation mode thereof solve the problems in the prior art, and particularly can realize direct decoupling of the contact information and the multiaxial force/moment information even if the elastic mechanism generates deformation and the field of view of the sensor for the contact information is kept constant under the condition that the elastic mechanism is cascaded at the bottom of the flexible material of the touch sensor. The solution provided by the invention can directly decouple the information of the two sensors, does not need to additionally calibrate and synchronize two measurement data, and can be directly called by a technician for use.
Another aspect of the embodiments of the present invention provides an electronic device, including one or more processors and a storage device, where the storage device is configured to store executable instructions, where the executable instructions when executed by the processors implement a method according to an embodiment of the present invention.
Another aspect of an embodiment of the present invention provides a computer-readable storage medium storing computer-executable instructions that, when executed by a processor, are configured to implement a method of an embodiment of the present invention.
Another aspect of embodiments of the present invention provides a computer program comprising computer executable instructions which, when executed, are adapted to carry out the method of embodiments of the present invention.
According to the embodiment of the invention, the floating working platform and the main body frame of the device are in an elastic connection mode, the acquisition activities of gel visual sensing information are all integrated in the floating working platform, meanwhile, as the optical sensor is fixed at the relative position of the floating working platform and the gel visual sensor information, the visual mark fixed in the main body frame and used for measuring multiaxial force/moment information moves relative to the optical sensor through the reflecting mirror. Two kinds of information can be captured by the optical sensor at the same time, so that the problems of coupling and crosstalk of two kinds of acquired information in the related technology can be at least partially solved, and the technical effect that synchronous acquisition does not need additional sensor information calibration can be realized.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the scope of the invention, as claimed.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and, together with the description, serve to explain the principles of the invention.
Fig. 1 is an exploded view of an apparatus for measuring contact information and multiaxial force/moment information according to an embodiment of the present invention.
Fig. 2 is a cross-sectional view of an apparatus for measuring contact information and multiaxial force/moment information according to an embodiment of the present invention.
Fig. 3 is a structural diagram of a floating work platform of an apparatus for measuring contact information and multiaxial force/moment information according to an embodiment of the present invention.
Fig. 4 is a diagram showing a measured multiaxial force/moment state of an apparatus for measuring contact information and multiaxial force/moment information according to an embodiment of the present invention.
Fig. 5 is a cross-sectional view of another apparatus for measuring contact information and multiaxial force/moment information in accordance with an embodiment of the present invention.
Reference numerals illustrate:
100 main body frame 200 floating working platform
300 perception media 400 mirror
500 visual marker element 600 optical sensor
700 elastic connector 310 optically transparent elastomer layer
320 optically transparent hard body layer 330 coating
510 visual marker element image one 520 visual marker element image two
800 ray path
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the spirit of the present disclosure will be clearly described in the following drawings and detailed description, and any person skilled in the art, after having appreciated the embodiments of the present disclosure, may make alterations and modifications by the techniques taught by the present disclosure without departing from the spirit and scope of the present disclosure.
The exemplary embodiments of the present invention and the descriptions thereof are intended to illustrate the present invention, but not to limit the present invention. In addition, the same or similar reference numerals are used for the same or similar parts in the drawings and the embodiments.
The terms "first," "second," …, and the like, as used herein, do not denote a particular order or sequence, nor are they intended to limit the invention, but rather are merely used to distinguish one element or operation from another in the same technical term.
With respect to directional terms used herein, for example: upper, lower, left, right, front or rear, etc., are merely references to the directions of the drawings. Thus, directional terminology is used for purposes of illustration and is not intended to be limiting.
As used herein, the terms "comprising," "including," "having," "containing," and the like are intended to be inclusive and mean an inclusion, but not limited to.
As used herein, "and/or" includes any or all combinations of such things.
Reference herein to "a plurality" includes "two" and "more than two"; the term "plurality of sets" as used herein includes "two sets" and "more than two sets".
The terms "about," "approximately" and the like as used herein are used to modify any quantitative or positional deviation that could vary slightly without such slight variation or positional deviation altering its nature. In general, the range of slight variations or errors modified by such terms may be 20% in some embodiments, 10% in some embodiments, 5% in some embodiments, or other values. It should be understood by those skilled in the art that the above mentioned values can be adjusted according to the actual requirements, and are not limited thereto.
All terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise defined. It should be noted that the terms used herein should be construed to have meanings consistent with the context of the present specification and should not be construed in an idealized or overly formal manner.
Where expressions like at least one of "A, B and C, etc. are used, the expressions should generally be interpreted in accordance with the meaning as commonly understood by those skilled in the art (e.g.," a system having at least one of A, B and C "shall include, but not be limited to, a system having a alone, B alone, C alone, a and B together, a and C together, B and C together, and/or A, B, C together, etc.). Where a formulation similar to at least one of "A, B or C, etc." is used, in general such a formulation should be interpreted in accordance with the ordinary understanding of one skilled in the art (e.g. "a system with at least one of A, B or C" would include but not be limited to systems with a alone, B alone, C alone, a and B together, a and C together, B and C together, and/or A, B, C together, etc.). It should also be appreciated by those skilled in the art that virtually any disjunctive word and/or phrase presenting two or more alternative items, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the items, either of the items, or both. For example, the phrase "a or B" should be understood to include the possibility of "a" or "B", or "a and B".
Fig. 1 is an exploded view of an apparatus for measuring contact information and multiaxial force/moment information according to an embodiment of the present invention, and the following description will explain an embodiment of the present invention with reference to fig. 1:
the embodiment of the invention provides a device for measuring contact information and multiaxial force/moment information, which comprises: a main body frame 100, a floating work platform 200, a sensing medium 300, a reflecting mirror 400, a visual marking element 500, an optical sensor 600; the main body frame 100, which carries the overall structure of the device for measuring contact information and multiaxial force/moment information, is used for connecting an external clamp; the visual marker element 500, which is fixed to the main body frame 100; the floating work platform 200, which is elastically connected to the main body frame 100; the sensing medium 300 is fixed on the floating working platform 200, and is used for obtaining the contact information of the sample to be tested, and feeding back the contact information, and the sensing medium 300 is any VBTS (vison-based tactile sensor); the reflecting mirror 400 is fixed on the floating working platform 200 and is used for reflecting the image of the visual marking element 500; the optical sensor 600 is fixed to the floating platform 200, and is used for acquiring the contact information and the position information of the image.
In this embodiment, the main body frame 100 of the device, which carries the overall structure of the device for measuring contact information and multiaxial force/moment information, is used for connecting an external clamp. The main body frame 100 is connected to the floating work platform 200 by elastic connection. Since the two parts are elastically connected and position movement, torsion and the like are generated during operation, a movable space exists between the main body frame 100 and the floating work platform 200, and interference is prevented during normal operation of the device.
The floating work platform 200 of the device carries the sensing medium 300, the reflecting mirror 400 and the optical sensor 600, and is used for stabilizing the observation field of view of the optical sensor 600 under each posture. Since the floating work platform 200 rigidly fixes the sensing medium 300, the reflecting mirror 400 and the optical sensor 600, the positional relationship is not changed any more, so that the coupling influence of the gesture on the acquisition of the contact information is not generated. The floating work platform 200 can ensure a stable field of view of the optical sensor 600 to the sensing medium 300 by only requiring contact of the workpiece to be measured with the sensing medium 300.
The visual marker element 500 of the device cooperates with the mirror 400 to capture the change in attitude of the device. Since the visual marker element 500 is fixed to the main body frame 100 and the reflecting mirror 400 is fixed to the floating work platform 200, and the main body frame 100 and the floating work platform 200 are in an elastically coupled state, there is a moving relationship therebetween. When the device measures multiaxial force/moment information, external force needs to be applied to the sample to be measured. Since the forces are applied to each other, the elastic connection between the main body frame 100 and the floating work platform 200 may be compressed, stretched or twisted to balance the external force applied to the device. The change of the posture and the position relationship between the two can directly cause the posture and the position relationship between the visual marking element 500 and the reflecting mirror 400 to change, so that the imaging of the visual marking element 500 in the reflecting mirror 400 can change doubly. The relationship is affected by the geometrical-optical relationship such as the distance, angle, etc. between the visual marker element 500 and the mirror 400, and the aforementioned multiple-change relationship can be adjusted by those skilled in the art through engineering.
The optical sensor 600 of the device is fixed to the floating work platform 200. When the device measures a measured sample, the optical sensor 600 receives two parts of image information in the field of view, one part of the image information is optical image information fed back by deformation generated after the sensing medium 300 contacts the measured sample, and the other part of the image information is optical image information of the visual marker element 500 reflected by the reflecting mirror 400. The two pieces of information are acquired simultaneously by the optical sensor 600. Wherein, the optical image information of deformation feedback generated after the sensing medium 300 contacts the measured sample contains the deformation information of the sensing medium 300, the deformation amount of the sensing medium 300 can be obtained by analyzing the image information, and the contact information of the measured sample can be obtained by calculating together with the physical parameters (such as elasticity coefficient, viscosity coefficient, mohs hardness and other physical attribute parameters) of the sensing medium 300; the optical image information of the visual marker element 500 reflected by the mirror 400 contains the position and posture information of the floating work platform 200 and the main body frame 100. The variation between the floating work platform 200 and the main body frame 100 is obtained by comparing the information with the calibrated information. Since the physical parameters (such as elasticity coefficient, viscosity coefficient, mohs hardness and other physical attribute parameters) of the elastic element directly connected with the two are known to those skilled in the art, and the elastic element can be selectively adjusted in engineering implementation, after knowing the variation and the physical parameters of the elastic element, the information of the stress and moment of the sample can be obtained by calculation.
Fig. 2 is a cross-sectional view of an apparatus for measuring contact information and multiaxial force/moment information according to an embodiment of the present invention.
The connection relationship of the respective components of the present embodiment is described below with reference to the correspondence relationship between the elements of fig. 1 and 2:
the body frame 100 is rigidly connected to the visual marker element 500;
the main body frame 100 is elastically connected to the floating work platform 200;
sensing medium 300 is rigidly connected to floating work platform 200;
mirror 400 is rigidly connected to floating work platform 200;
the optical sensor 600 is rigidly connected to the floating work platform 200.
There is a gap between the floating work platform 200 and the main body frame 100, and there is no interference when the floating work platform 200 moves relative to the main body frame 100. The components present within the field of view of optical sensor 600 include at least mirror 400, sensing medium 300, and imaging of visual marker element 500 within mirror 400.
Fig. 3 is a structural diagram of a floating work platform 200 of an apparatus for measuring contact information and multiaxial force/moment information according to an embodiment of the present invention. For easier understanding of the present embodiment, a description will be given of the components in this embodiment that are in connection with the inside of floating work platform 200.
The floating work platform 200 and the links are provided as separate components that carry the sensing medium 300, the mirror 400, and the optical sensor 600. In the case of measuring the surface contact information of the sample to be measured, the floating working platform 200, the sensing medium 300 and the optical sensor 600 are rigidly connected, so that the three components form a whole, and the relative positional relationship and the torsion relationship among the three components are not affected by the position and the posture change of the whole. The floating work platform 200 acts as a work platform to support a stable field of view environment for the optical sensor 600. The external force applied by the external clamp does not affect the positional relationship inside the floating work platform 200 when measuring the multiaxial force/moment information of the sample to be measured.
Decoupling in engineering refers to decoupling the coupling relationship between modules or components such that the dependencies between them are as small as possible. In the measurement field, the reduction of the coupling degree can be understood as decoupling, and the coupling is necessarily present when there is a dependency relationship between measurement sensors, but the coupling degree can be reduced to the minimum by some existing methods.
The device for measuring contact information and multiaxial force/moment information of the present embodiment has an advantage of automatic decoupling compared with the prior art. Because in the prior art, when the elastic mechanism is deformed, the plane at the bottom of the flexible body of the upper Fang Chujiao sensor can deviate, so that the field of view of the flexible body (contact information) in the camera is not constant, and the calibration result of the contact information is affected. Since the two information are coupled to each other, there is always a crosstalk error in both the calibration process and the actual measurement.
Fig. 4 is a diagram showing a measured multiaxial force/moment state of an apparatus for measuring contact information and multiaxial force/moment information according to an embodiment of the present invention. To understand that in this embodiment, no crosstalk occurs between the measured multiaxial force/moment information and the measured contact information, a description will now be made with reference to fig. 4.
Fig. 4 is a graph comparing the positional relationship of the device for measuring contact information and multiaxial force/moment information after calibration and the multiaxial force/moment state measurement. As is apparent from fig. 4, the device uses the reference line as a reference object when an external force is applied, and the position of the floating work platform 200 is changed, but the position of the visual marking element 500 is not changed. Its imaging in mirror 400 is moved by the position of visual marker element image one 510 and twisted to the position of visual marker element image two 520. It is known from geometrical optics that when an object moves relative to a mirror, the relationship between the movement of the object's image and the movement of the object is affected by the following parameters: the distance between the object and the mirror, the angle between the object and the mirror, the speed of the object. When an object moves relative to the mirror, its image will also move. If the object moves to the left, it moves like to the right. If the object moves to the right, it moves like to the left. When an object moves up or down, it will also move up or down. This change in position is captured by the optical sensor 600 for calculation of multi-axis force/moment information.
Fig. 5 is a cross-sectional view of another apparatus for measuring contact information and multiaxial force/moment information in accordance with an embodiment of the present invention. In this embodiment, the device components are optimized, as described below:
in the present embodiment, the sensing medium 300 includes: an optically transparent elastomer layer 310, an optically transparent hard body layer 320; the optically transparent elastomer layer 310 has a first surface and a second surface, the first surface is a working surface for measurement, and an optical coating 330 is provided inside the first surface and is reflected toward the inside of the optically transparent elastomer layer 310 and the second surface; the optically transparent hard body layer 320 is attached to the second surface of the optically transparent elastomeric layer 310. The working surface of the optically transparent elastomer layer 310 is printed with a coating 330, the pattern of the layer comprising: printing a marking array and an ultraviolet marking array.
The optically transparent elastomer layer 310 has a first surface for directly contacting the sample to be measured and a second surface for bonding to the optically transparent hard layer. The optically transparent hard layer provides stable support for the overlying optically transparent elastomeric layer 310. An optical coating 330 is provided on the first surface towards the inside of the optically transparent elastomeric layer 310, the coating 330 being adapted to reflect light towards the optical sensor 600. The back side of the coating 330 is printed with a coating 330 pattern, the coating 330 pattern comprising an array of printed indicia, an array of ultraviolet indicia 330 pattern for reflecting light of a specific wavelength from the coating. Due to the reflective and absorptive properties of light of different wavelengths for the material, the optical sensor 600 can approximate the normal force and shear force distribution experienced by the optically transparent elastomer layer 310 by calculating the deformation of the array for images reflected by two different arrays.
The device for measuring contact information and multiaxial force/moment information in this embodiment further includes a light supplement lamp as compared with the previous embodiment; the light supplementing lamp is fixed inside the floating working platform 200 and is used for supplementing light to the sensing medium 300. The light supplementing lamp can use red, green, blue and white luminous patch LEDs. In order to optimize the imaging quality of the optical sensor 600, a gray filter film or a diffusion film is attached between the light supplement lamp and the sensing medium 300. Preferably, the light supplement lamp may be selected from the group of LUXEON 2835Color Line SMD LED.
The device for measuring contact information and multiaxial force/moment information in this embodiment has a set reflectivity of the optical coating 330 as compared to the previous embodiment. In order to optimize the imaging quality of the optical sensor 600, the optical coating 330 may be designed with different reflectivity distribution patterns, and the central field of view, the printed mark array, and the ultraviolet mark array may be adjusted to have different coating patterns, so as to increase or decrease the reflectivity of the above positions, thereby improving the imaging quality and sensitivity. The deformation of the optically transparent elastomer layer 310 directly affects the deformation of the printed mark array, the ultraviolet mark array, and the ultraviolet mark array printed on the coating. When the optical transparent elastomer layer 310 receives tangential force, the optical elastomer layer deforms to drive the array to deform, so that the density change can be generated at the marking points of the marking array in the tangential force direction, and the tangential force magnitude received by the marking array can be approximately calculated through the change of the marking array before and after receiving the tangential force.
Since the floating work platform 200 and the main body frame 100 together constitute a suspension structure, it can realize a wide range of ranges for multi-axis force/moment information, and thus can reduce the thickness and hardness of the optical elastomer layer outer coating. When the engineering is realized, transparent silica gel with the Shore hardness of A15 can be used as a substrate, and then an organosilicon diluent is added for doping, spraying and coating. For this coating 330, an abrasion-resistant matte oil may be further used to protect the surface of the optical elastomer layer.
The device for measuring contact information and multiaxial force/moment information in this embodiment, the optically transparent elastomer layer 310 comprises: transparent rubber, gel or silica gel. The optically transparent hard body layer 320 comprises the following constituent materials: high light transmission glass and acrylic.
Embodiments of the present invention provide an apparatus for measuring contact information and multiaxial force/moment information, the floating work platform 200 being elastically connected to the main body frame 100;
the elastic connection, which constrains the spatial degrees of freedom of the floating work platform 200 and the main body frame 100, includes spatial degrees of freedom and rotational degrees of freedom in a cartesian coordinate system. The connection mode allows the connection part to stretch and retract axially and shear to turn. Factors influencing the magnitude of the force generated by the axial elastic deformation are mainly the following: modulus of elasticity of the material: the elastic modulus is the rigidity coefficient of the material in the elastic deformation range, and the larger the elastic modulus is, the better the elastic deformation capability of the material is. Cross-sectional area of material: the larger the cross-sectional area, the better the elastic deformability of the material when subjected to an external force. The formula for calculating the force generated by elastic deformation is: f=kx, where F is the force generated by elastic deformation, k is the elastic constant, x is the length of elastic deformation; factors influencing the amount of force generated by shear to elastic deformation are mainly the following: shear modulus of material: the shear modulus is the stiffness coefficient of a material in the shear deformation range, and the larger the shear modulus is, the better the shear deformation capability of the material is. Cross-sectional area of material: the larger the cross-sectional area, the better the elastic deformability of the material when subjected to an external force. In terms of engineering implementation, it is preferable that the elastic connection members 700 for constraining the spatial degrees of freedom of the floating work platform 200 and the main body frame are arranged on spatial cartesian coordinate axes, three coordinate axes being spatially perpendicular to each other. The axial elastic deformation of the three elastic connectors 700 together restrict the relative displacement of the three elastic connectors in the respective axial directions, and the shearing elastic deformation of the three elastic connectors 700 together restrict the relative rotation of the three elastic connectors in the respective axial directions. Therefore, after calibrating the deformation relationship and the multiaxial force/moment relationship of the three elastic connection members 700, multiaxial force/moment information can be obtained by calculating the positional relationship of the two.
In this embodiment, in order to constrain the spatial degrees of freedom between the floating platform 200 and the main frame 100, there is a more compact elastic connection manner, in which a plurality of elastic elements, such as springs, torsion springs, elastic slides, etc., are arranged in a multi-position normal direction on the same plane (e.g., the second plane of the optically transparent elastomer layer 310). The difference in position between the elastic elements will create a multiaxial force/moment to the plane which balances the externally loaded multiaxial force/moment. In selecting the plane, it is preferable to include: the floating platform interfaces with a second plane of optically transparent elastomer layer 310.
The present embodiment provides a device for measuring contact information and multiaxial force/moment information, wherein the reflecting mirror 400 is fixed on the floating working platform 200 and is attached to the lower surface of the sensing medium 300. It is known from geometrical optics that when an object moves relative to a mirror, the relationship between the movement of the object's image and the movement of the object is affected by the following parameters: the distance between the object and the mirror, the angle between the object and the mirror, the speed of the object. When an object moves relative to the mirror, its image will also move. As can be seen from the relationship of fig. 4, the displacement and rotation of the mirror 400 directly causes the position change and rotation of the image of the visual marker element 500, and the amount of the position change of the image is related to the following factors: the distance between the visual marking element 500 and the mirror 400, the angle between the visual marking element 500 and the mirror 400, the distance between the visual marking and the axis of rotation. It is apparent that the greater the distance between the visual marking element 500 and the mirror 400, the greater the displacement of the image of the visual marking element 500 as the mirror 400 is displaced tangentially about the axis of rotation, which is directly proportional to the distance between the visual marking element 500 and the mirror 400. The larger the angle between the visual marker element 500 and the normal to the mirror 400, the larger the displacement of the image of the visual marker element 500 as the mirror 400 rotates about itself about the axis of rotation, which is in cosine direct proportion to the angle between the visual marker element 500 and the normal to the mirror 400. In this embodiment, the visual marker 500 is fixed inside the main frame 100, and on the one hand, the distance between the visual marker 500 and the mirror 400 is as large as possible without enlarging the volume of the whole device. Thus, in the case where the floating work platform 200 and the main body frame 100 are relatively rotated, the image of the visual marker element 500 is displaced as much as possible, thereby providing a high sensitivity possibility for the optical sensor 600 to acquire the position information of the image.
The device for measuring contact information and multiaxial force/moment information provided in this embodiment further includes a microprocessor as compared with the previous embodiment; the microprocessor is connected to the optical sensor 600 and is used for acquiring the image signal of the optical sensor 600. By acquiring the attitude change amount of the marking element in the image of the optical sensor 600, the attitude change amounts of the floating working platform 200 and the main body frame 100 are calculated and obtained, and then multiaxial force/moment information is calculated and obtained; and obtaining the contact information by calculation through obtaining the image change of the optical image layer. In engineering implementation, the microprocessor and the optical sensor 600 may be integrated together into a PCB board to simplify the structure. The microprocessor is used as a localization operation unit of the device for measuring the contact information and the multiaxial force/moment information, can locally calculate image information in real time according to the operation capability of the actually selected chip, and can send the settled contact information and multiaxial force/moment information to an external request machine or send the image information to an external lower computer for external calculation. Preferably, the microprocessor is selected as an ESP32MCU with a ceramic antenna for transmitting the captured image to a remote workstation. In order to balance the sampling frequency, delay and image resolution, the ESP32MCU microprocessor runs an RTSP server to transmit images in JPEG format at a frame rate of 26FPS per second.
The device for measuring the contact information and the multiaxial force/moment information provided by the embodiment further comprises a wired/wireless communication module and a power supply unit; the wired/wireless communication module is connected to the microprocessor and is used for communicating with external communication equipment. The power supply unit is connected to the microprocessor and is used for supplying power to the microprocessor, the optical sensor 600 and the light supplementing lamp.
The device for measuring contact information and multiaxial force/moment information provided in this embodiment has a connection mode of elastic connection comprising: spring, torsional spring, reed, elastic rubber, piezoelectric ceramics, elastic slideway.
Embodiments of the present invention provide an apparatus for measuring contact information and multiaxial force/moment information, the visual marker element 500 including, but not limited to: artoolgit, AR Tag, arUco Tag, april Tag, QR Code, framedge, markers.
The embodiment of the invention provides a device for measuring contact information and multiaxial force/moment information, the number of the optical sensors is more than or equal to one, and the optical sensors comprise: monocular, binocular, infrared cameras. In practice, a person skilled in the art may arrange a plurality of optical sensors according to the position of the visual marking element and the position of the mirror, so as to obtain a better field of view. On the other hand, in order to adapt to the demands of various working conditions, the type of the optical sensor can be selected as a monocular camera, a binocular camera and an infrared camera.
The following can be obviously known from the examples provided by the invention:
(1) The flexible silica gel with the reflective film coated on the upper surface is used as a medium for sensing contact information, and the optical sensor 600 and the floating working platform 200 are fixed so that the relative positions of the two are kept unchanged in order to achieve the technical effect that the visual field of the contact information is kept unchanged. A mirror is fixed on the floating working platform 200 to reflect a visual mark with a constant position, and when the spring structure is deformed, the whole floating working platform 200, the mirror and the camera all follow the elastic deformation movement, the visual mark is fixed, but the mark is relatively moved in the visual field of the camera through reflection in the mirror. Therefore, in the image captured by the optical sensor 600, the field of view of the contact information is kept unchanged all the time, and the visual mark moves along with the deformation of the elastic structure, so that the function of decoupling the two information is achieved.
(2) In the sensor calibration, since the two kinds of information are decoupled, the corresponding calibration can be performed alone. The contact information part can adopt a corresponding calibration method, and the multiaxial force/moment information only needs to map the relation between the movement of the visual mark and the multiaxial force/moment (by connecting an additional multiaxial force/moment sensor as a true value).
(3) Since the contact information and the multiaxial force/moment information originate from different areas of the same captured image, the two information are synchronized.
According to an embodiment of the present invention, the method flow according to an embodiment of the present invention may be implemented as a computer software program. For example, embodiments of the present invention include a computer program product comprising a computer program embodied on a computer readable storage medium, the computer program comprising program code for performing the method shown in the flowcharts. According to embodiments of the present invention, the above-described electronic devices, apparatuses, modules, units, etc. may be implemented by computer program modules.
The present invention also provides a computer-readable storage medium that may be embodied in the apparatus/device/system described in the above embodiments; or may exist alone without being assembled into the apparatus/device/system. The computer-readable storage medium carries one or more programs which, when executed, implement methods in accordance with embodiments of the present invention.
According to embodiments of the present invention, the computer-readable storage medium may be a non-volatile computer-readable storage medium, which may include, for example, but is not limited to: a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams or flowchart illustration, and combinations of blocks in the block diagrams or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
Those skilled in the art will appreciate that the features recited in the various embodiments of the invention and/or in the claims may be combined in various combinations and/or combinations, even if such combinations or combinations are not explicitly recited in the invention. In particular, the features recited in the various embodiments of the invention and/or in the claims can be combined in various combinations and/or combinations without departing from the spirit and teachings of the invention. All such combinations and/or combinations fall within the scope of the invention.
The embodiments of the present invention are described above. However, these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Although the embodiments are described above separately, this does not mean that the measures in the embodiments cannot be used advantageously in combination. The scope of the invention is defined by the appended claims and equivalents thereof. Various alternatives and modifications can be made by those skilled in the art without departing from the scope of the invention, and such alternatives and modifications are intended to fall within the scope of the invention.
Claims (16)
1. An apparatus for measuring contact information and multiaxial force/moment information, comprising: the device comprises a main body frame, a floating working platform, a sensing medium, a reflecting mirror, a visual marking element and an optical sensor;
the main body frame is used for bearing the integral structure of the device for measuring the contact information and the multiaxial force/moment information and connecting an external clamp;
the visual marker element is fixed to the main body frame;
the floating working platform is elastically connected to the main body frame;
the sensing medium is fixed on the floating working platform and is used for acquiring the contact information of the sample to be tested and feeding back the contact information;
The reflecting mirror is fixed on the floating working platform and is used for reflecting the image of the visual marking element;
the optical sensor is fixed on the floating working platform and used for acquiring the contact information and the position information of the image.
2. The apparatus for measuring contact information and multiaxial force/moment information of claim 1 where said sensing medium comprises: an optically transparent elastomer layer, an optically transparent duromer layer;
the optical transparent elastomer layer is provided with a first surface and a second surface, wherein the first surface is a working surface for measurement, and an optical coating layer which is reflected towards the inside of the optical transparent elastomer layer and the second surface is arranged inside the first surface;
the optically transparent hard body layer is attached to the second surface of the optically transparent elastomeric layer.
3. The apparatus for measuring contact information and multiaxial force/moment information of claim 2 where the working surface of the optically transparent elastomeric layer is printed with a coating, the pattern of the layer comprising: printing a marking array and an ultraviolet marking array.
4. The apparatus for measuring contact information and multiaxial force/moment information of claim 2 further comprising a light supplement lamp;
And the light supplementing lamp is fixed inside the floating working platform and is used for supplementing light to the sensing medium.
5. The apparatus for measuring contact information and multiaxial force/moment information of claim 2 where said optical coating has a set reflectivity.
6. The apparatus for measuring contact information and multiaxial force/moment information of claim 2 where said optically transparent elastomeric layer is comprised of materials comprising: transparent rubber, gel or silica gel.
7. The apparatus for measuring contact information and multiaxial force/moment information of claim 2 where said optically transparent hard body layer is comprised of materials comprising: high light transmission glass and acrylic.
8. The apparatus for measuring contact information and multiaxial force/moment information of claim 1 where the floating work platform is resiliently connected to the body frame;
the elastic connection constrains the spatial degrees of freedom of the floating work platform and the main body frame to include spatial degrees of freedom and rotational degrees of freedom in a Cartesian coordinate system.
9. The apparatus for measuring contact information and multiaxial force/moment information of claim 1 where said mirror is affixed to said floating work platform for reflecting an image of said visual marker element;
The reflector is fixed on the floating working platform and is attached to the lower surface of the sensing medium.
10. The apparatus for measuring contact information and multiaxial force/moment information of claim 1 where said visual marker element is affixed to said body frame;
the visual marker element is secured to the interior of the body frame.
11. The apparatus for measuring contact information and multiaxial force/moment information of claim 1 further comprising a microprocessor;
the microprocessor is connected to the optical sensor and used for acquiring the image signals of the optical sensor.
12. The apparatus for measuring contact information and multiaxial force/moment information of claim 11 further comprising a wired/wireless communication module;
the wired/wireless communication module is connected to the microprocessor and is used for communicating with external communication equipment.
13. The apparatus for measuring contact information and multiaxial force/moment information of claim 11 further comprising a power supply unit;
and the power supply unit is connected with the microprocessor and is used for supplying power to the microprocessor, the optical sensor and the light supplementing lamp.
14. The apparatus for measuring contact information and multiaxial force/moment information of claim 1 where the floating work platform is resiliently connected to the body frame;
the elastic connection comprises the following connection modes: spring, torsion spring, reed, elastic rubber and piezoelectric ceramics.
15. The apparatus for measuring contact information and multiaxial force/moment information of claim 1 where the visual marker elements include, but are not limited to: artoolgit, AR Tag, arUco Tag, april Tag, QR Code, framedge, markers.
16. The apparatus for measuring contact information and multiaxial force/moment information of claim 1 where the number of optical sensors is one or more, the optical sensors comprising:
monocular, binocular, infrared cameras.
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