Flexible assembly system and method

Patent metadata

Field	Value
Publication number	US-11724344-B2
Application number	US-202117909188-A
Country	US
Kind code	B2
Filing date	Mar 3, 2021
Priority date	Dec 31, 2020
Publication date	Aug 15, 2023
Grant date	Aug 15, 2023

Abstract

A flexible assembly system includes an industrial personal computer, a data collection card, a motion control card, a six-degree-of-freedom assembly platform, a first visual platform, a second visual platform and a supporting platform. The six-degree-of-freedom assembly platform includes a four-degree-of-freedom motion platform and a two-degree-of-freedom adjustment device, the two-degree-of-freedom adjustment device includes a two-degree-of-freedom motion platform and a clamping mechanism, and the clamping mechanism includes an outer frame, a flexible wrist rotatably connected in the outer frame, two clamping sheets mounted on the flexible wrist, two driving parts corresponding to the two clamping sheets, two first force sensors provided on the outer frame and two second force sensors provided on the flexible wrist; a first image collection apparatus is mounted on the first visual platform, and a second image collection apparatus is mounted on the second visual platform. A flexible assembly method is also disclosed.

First claim

What is claimed is:

1. A flexible assembly system, comprising an industrial personal computer, a data collection card, a motion control card, a six-degree-of-freedom assembly platform, a first visual platform, a second visual platform and a supporting platform; wherein the data collection card and the motion control card are both connected with the industrial personal computer, the six-degree-of-freedom assembly platform comprises a four-degree-of-freedom motion platform and a two-degree-of-freedom adjustment device, the two-degree-of-freedom adjustment device comprises a two-degree-of-freedom motion platform and a clamping mechanism mounted on the two-degree-of-freedom motion platform, and the clamping mechanism comprises an outer frame, a flexible wrist rotatably connected in the outer frame, two clamping sheets mounted on the flexible wrist, two driving parts corresponding to the two clamping sheets, two first force sensors provided on the outer frame and two second force sensors provided on the flexible wrist; a first image collection apparatus is mounted on the first visual platform, and a second image collection apparatus is mounted on the second visual platform.

2. The flexible assembly system according to claim 1 , wherein the four-degree-of-freedom motion platform comprises a base, a first motor, a second motor, a third motor, a fourth motor, a Y-axis linear motion platform mounted on the base, an X-axis linear motion platform mounted on the Y-axis linear motion platform, a Z-axis linear motion platform mounted on the X-axis linear motion platform, and a Z-axis rotary motion platform mounted on the Z-axis linear motion platform.

3. The flexible assembly system according to claim 2 , wherein the two-degree-of-freedom motion platform comprises a fifth motor, a sixth motor, an X-axis rotary motion platform and a Y-axis rotary motion platform; the fifth motor drives the X-axis rotary motion platform to rotate around the X axis, and the sixth motor drives the Y-axis rotary motion platform to rotate around the Y axis.

4. The flexible assembly system according to claim 1 , wherein the flexible wrist comprises an outer ring and an inner ring, the outer ring is rotatably connected with the outer frame, and the inner ring is rotatably connected with the outer ring; the two clamping sheets are mounted on the inner ring; the two first force sensors are a first outer ring force sensor and a second outer ring force sensor respectively, the two second force sensors are a first inner ring force sensor and a second inner ring force sensor respectively, the first outer ring force sensor and the second outer ring force sensor are oppositely mounted on the outer frame, the first inner ring force sensor and the second inner ring force sensor are oppositely mounted on the outer ring, and the first inner ring force sensor, the second inner ring force sensor, the first outer ring force sensor and the second outer ring force sensor are all connected with the data collection card.

5. The flexible assembly system according to claim 4 , wherein a mounting hole is provided in the inner ring, a middle part of the mounting hole is connected with a balancing weight, and the balancing weight is provided with at least one balancing weight hole.

6. A flexible assembly method, in which the system according to claim 4 is used, comprising the following steps:
(1) a first to-be-assembled part is placed in a clamping region, and a second to-be-assembled part is placed on the supporting platform;
(2) the two clamping sheets are controlled by the industrial personal computer to clamp the first to-be-assembled part;
(3) the industrial personal computer controls the first visual platform and the second visual platform to move through the motion control card, such that the first image collection apparatus and the second image collection apparatus are located at optimal viewing angle positions;
(4) the industrial personal computer acquires image signals of the first image collection apparatus and the second image collection apparatus, so as to obtain a position and a posture of the second to-be-assembled part, controls the six-degree-of-freedom assembly platform to roughly adjust the posture of the first to-be-assembled part, then controls the two-degree-of-freedom adjustment device to stabilize the clamping state of the first to-be-assembled part, and then slowly finishes fine adjustment of the posture of the first to-be-assembled part in a process of controlling the first to-be-assembled part to approach the second to-be-assembled part through the six-degree-of-freedom assembly platform; and
(5) in a stage of assembly contact between the first to-be-assembled part and the second to-be-assembled part, the industrial personal computer acquires a force signal for clamping the first to-be-assembled part through the data collection card, and in a deep assembly stage, the industrial personal computer controls the six-degree-of-freedom assembly platform through the motion control card to perform fine movement adjustment, so as to finally complete the assembly of the first to-be-assembled part and the second to-be-assembled part.

7. The flexible assembly method according to claim 6 , wherein the step (4) that the industrial personal computer controls the two-degree-of-freedom adjustment device to stabilize the clamping state of the first to-be-assembled part comprises:
when the industrial personal computer detects a force signal of the first outer ring force sensor, the outer ring is in a state of deflecting leftwards around the X axis in the positive direction of the X axis, and the industrial personal computer controls a two-degree-of-freedom rotary platform to deflect rightwards around the X axis in the positive direction of the X axis; when the industrial personal computer detects that the force signal of the first outer ring force sensor is less than a certain threshold, the outer ring and the first outer ring force sensor are in a contact-free state or an unstressed state;
when the industrial personal computer detects a force signal of the second outer ring force sensor, the outer ring is in a state of deflecting rightwards around the X axis in the positive direction of the X axis, and the industrial personal computer controls the two-degree-of-freedom rotary platform to deflect leftwards around the X axis in the positive direction of the X axis; when the industrial personal computer detects that the force signal of the second outer ring force sensor is less than a certain threshold, the outer ring and the second outer ring force sensor are in a contact-free state or an unstressed state;
when the industrial personal computer detects a force signal of the first inner ring force sensor, the inner ring is in a state of deflecting leftwards around the Y axis in the positive direction of the Y axis, and the industrial personal computer controls the two-degree-of-freedom rotary platform to deflect rightwards around the Y axis in the positive direction of the Y axis; when the industrial personal computer detects that the force signal of the first inner ring force sensor is less than a certain threshold, the inner ring and the first inner ring force sensor are in a contact-free state or an unstressed state;
when the industrial personal computer detects a force signal of the second inner ring force sensor, the inner ring is in a state of deflecting rightwards around the Y axis in the positive direction of the Y axis, and the industrial personal computer controls the two-degree-of-freedom rotary platform to deflect leftwards around the Y axis in the positive direction of the Y axis; when the industrial personal computer detects that the force signal of the second inner ring force sensor is less than a certain threshold, the inner ring and

Assignees

• Univ Soochow

Inventors

• Chen Tao
• Tian Yuxiang
• Tian Xiandong
• Sun Lining
• Ni Kejian
• Huang Zhiying

Classifications

• B23P19/00 Primary

  Machines for simply fitting together or separating metal parts or objects, or metal and non-metal parts, whether or not involving some deformation {(connecting metal parts or objects by metal-working procedures B21J, B23K)}; Tools or devices therefor so far as not provided for in other classes (hand tools in general B25) · CPC title

• B23P21/00

  Machines for assembling a multiplicity of different parts to compose units, with or without preceding or subsequent working of such parts, e.g. with program control · CPC title

• B25J7/00 Primary

  Micromanipulators {(specimen supports for investigating or analysing materials G01N23/2204; associated with microscopes G02B21/32; means for supporting or positioning the objects or the material in discharge tubes H01J37/20)} · CPC title

• B25J9/023

  Cartesian coordinate type · CPC title

• B25J13/085

  Force or torque sensors (B25J13/082, B25J13/084 take precedence) · CPC title