CN-115107074-B - Clamping device, robot and force information sensing method

CN115107074BCN 115107074 BCN115107074 BCN 115107074BCN-115107074-B

Abstract

The invention provides a clamping device, a robot and a force information sensing method. The clamping device comprises a shell a plurality of link clamping assemblies and drive assemblies for cooperating to clamp an object. Each connecting rod clamping assembly comprises a fingertip, a first rod piece, a second rod piece and a third rod piece, wherein the fingertip, the first rod piece, the second rod piece and the third rod piece are used for clamping an object. The first rod piece is fixedly connected with the fingertip. The first end of the second rod piece is rotationally connected with the first end of the first rod piece, and the second end of the second rod piece is rotationally connected with the shell. The first end of the third rod piece is rotationally connected with the second end of the first rod piece, and the second end of the third rod piece is rotationally connected with the shell. The driving component is in transmission connection with the second end of the second rod piece and is used for driving the second rod piece to rotate. The clamping device further comprises a plurality of force transducers respectively arranged on at least three of the first rod piece, the second rod piece, the third rod piece and the driving component and configured to measure the axial force of the at least three when the clamping device is in static balance so as to be used for calculating the force information output by fingertips.

Inventors

CHANG JINCHAO
ZHOU YISHUN
JIANG HAO

Assignees

上海非夕机器人科技有限公司
非夕科技有限公司

Dates

Publication Date: 20260505
Application Date: 20220805

Claims (9)

1. A clamping device, comprising: A housing; a plurality of link clamping assemblies for cooperating with one another to clamp an object, each link clamping assembly comprising: A fingertip for holding an object; the first rod piece is fixedly connected with the fingertip; a second rod member having a first end rotatably connected to the first end of the first rod member and a second end rotatably connected to the housing, and The first end of the third rod piece is rotationally connected with the second end of the first rod piece, and the second end of the third rod piece is rotationally connected with the shell; A driving assembly in driving connection with the second end of the second rod member for driving the second rod member to rotate, and The plurality of single-shaft axial force sensors are respectively embedded in at least three of the first rod piece, the second rod piece, the third rod piece and the driving assembly along the axial direction and are configured to measure the internal axial force of the at least three when the clamping device is in static balance so as to be used for establishing a statics model according to the structural parameters and the position parameters of the first rod piece, the second rod piece and the third rod piece to calculate force information output by the fingertip, wherein the force information comprises tangential force, normal force and bending moment of the fingertip along a contact surface.
2. The clamping device of claim 1, wherein at least the third rod is axially embedded with one of the single axis force sensors to measure the internal axial force of the third rod when the clamping device is in static equilibrium.
3. The clamping device of claim 1, wherein the drive assembly comprises: A motor; the screw rod is connected with the output end of the motor so as to drive the screw rod to rotate along the axial direction by the motor; a nut engaged with the screw, the nut moving in an axial direction of the screw when the screw is rotated, and The plurality of transmission parts are respectively corresponding to each connecting rod clamping assembly, wherein the first ends of the transmission parts are rotationally connected with the nuts, and the second ends of the transmission parts are fixedly connected with the second ends of the second rod pieces, so that when the motor axially drives the screw rod to rotate, the nuts drive the second rod pieces to rotate.
4. A clamping arrangement according to claim 3, wherein the drive assembly is provided with one of the axial force sensors configured for measuring the driving force output by the drive assembly in the axial direction of the screw.
5. The clamping device of claim 1, wherein the plurality of force sensors are embedded axially in the first, second, and third bars, respectively, to measure internal axial forces of the first, second, and third bars, respectively, when the clamping device is in static equilibrium.
6. The gripping device of claim 1 wherein the fingertip is further provided with a multiple degree of freedom sensor to measure force information of the fingertip when the fingertip is used to grip an object.
7. A robot comprising the gripping device of any one of claims 1 to 6, the robot further comprising: A position measuring device for measuring structural parameters and position parameters of the first, second and third bars, the structural parameters including length values of the first, second and third bars, the position parameters including attitude vectors of the first, second and third bars, and And the control system is used for acquiring measured values of the position measuring device and the plurality of single-axis axial force sensors when the clamping device is in static balance, respectively establishing static models of the first rod piece, the second rod piece, the third rod piece and the driving assembly, and calculating to obtain force information output by fingertips.
8. A force information sensing method applied to the clamping device of claim 1, comprising: acquiring force measurements of the plurality of uniaxial axial force sensors when the clamping device is in static balance; Measuring structural and positional parameters of the first, second, and third bars, and And respectively establishing a statics model of the first rod piece, the second rod piece, the third rod piece and the driving assembly according to the measured force measurement value, the measured structural parameter and the position parameter, and calculating to obtain force information output by the fingertip, wherein the force information comprises tangential force, normal force and bending moment of the fingertip along a contact surface.
9. The method of claim 8, wherein establishing a statics model of the first rod, the second rod, the third rod, and the drive assembly, respectively, based on the measured force measurements, the measured structural parameters, and the positional parameters comprises: simplifying the first rod piece, the second rod piece and the third rod piece into a two-force rod model, simplifying the driving assembly and the second rod piece into a moment balance model, Performing static stress analysis on the two-force rod model and the moment balance model, and And respectively establishing a statics model of the first rod piece, the second rod piece, the third rod piece and the driving assembly.

Description

Clamping device, robot and force information sensing method Technical Field The present disclosure relates to robots, and particularly to a clamping device, a robot with the clamping device, and a force information sensing method applied to the clamping device. Background The gripping device is an important end effector of the robot. The gripping device is typically driven by a drive assembly, with gripping or releasing of the object being accomplished by the fingertips of the gripping device. When the gripping device performs a process of gripping an object, in particular a fragile object, it is necessary to keep the force applied to the object by the fingertip proper and stable, and it is therefore important to monitor the force information output by the fingertip relative to the object. Disclosure of Invention A first aspect of an embodiment of the present invention provides a clamping device, including a housing, a plurality of link clamping assemblies and a driving assembly for cooperating with each other to clamp an object, each link clamping assembly including a fingertip for clamping the object, a first lever, a second lever, and a third lever. The first rod piece is fixedly connected with the fingertip. The first end of the second rod piece is rotationally connected with the first end of the first rod piece, and the second end of the second rod piece is rotationally connected with the shell. The first end of the third rod piece is rotationally connected with the second end of the first rod piece, and the second end of the third rod piece is rotationally connected with the shell. The driving component is in transmission connection with the second end of the second rod piece and is used for driving the second rod piece to rotate. The clamping device further comprises a plurality of force transducers respectively arranged on at least three of the first rod piece, the second rod piece, the third rod piece and the driving component and configured to measure the axial force of the at least three when the clamping device is in static balance so as to be used for calculating the force information output by fingertips. In some embodiments, at least the third rod is axially embedded with a load cell to measure an axial force of the third rod when the clamping device is in static balance, wherein the axial force refers to an internal axial force of the third rod. In some embodiments, the driving assembly comprises a motor, a screw, a nut and a plurality of transmission members, wherein the screw is connected with an output end of the motor to drive the screw to rotate in the axial direction, the nut is matched with the screw, when the screw rotates, the nut moves in the axial direction of the screw, the plurality of transmission members respectively correspond to each connecting rod clamping assembly, a first end of each transmission member is rotationally connected with the nut, and a second end of each transmission member is fixedly connected with a second end of the second rod member, so that when the motor drives the screw to rotate in the axial direction, the nut drives the second rod member to rotate. In some embodiments, the drive assembly is provided with a load cell configured to measure the driving force output by the drive assembly in the axial direction of the lead screw. In some embodiments, a plurality of force sensors are embedded in the first rod, the second rod, and the third rod, respectively, in an axial direction to measure axial forces of the first rod, the second rod, and the third rod, respectively, when the clamping device is in static equilibrium, wherein the axial forces refer to internal axial forces of the first rod, the second rod, and the third rod. In some embodiments, the force information includes tangential force, normal force, and bending moment of the fingertip along the contact surface. In some embodiments, the fingertip is further provided with a multiple degree of freedom sensor to measure force information of the fingertip when the fingertip is used to grip an object. A second aspect of the embodiment of the invention provides a robot, which comprises the clamping device, the position measuring device and the control system of any of the embodiments, wherein the position measuring device is used for measuring structural parameters and position parameters of the first rod piece, the second rod piece and the third rod piece, the structural parameters comprise length values of the first rod piece, the second rod piece and the third rod piece, the position parameters comprise attitude vectors of the first rod piece, the second rod piece and the third rod piece, and the control system is used for acquiring measured values of the position measuring device and a plurality of force sensors when the clamping device is in static balance, respectively establishing static models of the first rod piece, the second rod piece, the third rod piece and the driving assembly, and calculat