ROBOTIC STRUCTURE WITH SIX DEGREES OF FREEDOM ALLOWING GRIPPING

Abstract

Some embodiments are directed to a parallel robotic structure with six degrees of freedom, comprising movable bases that can be rotated or translated. A platform coupled with the movable bases by moving elements, wherein the platform is made up of two rigid elements connected to one another by a single articulation. This parallel robotic structure makes it possible to perform cutting, gripping and manipulating operations simultaneously with six degrees of without requiring an additional tool. The gripping functionality is provided due to the articulated platform, which is an integral part of the mechanical architecture and can be entirely controlled by the offset actuators located in the stationary base.

Claims

1. A parallel robotic structure with six degrees of freedom, comprising: movable bases that can be rotated or translated; and a platform coupled with the movable bases by an arm made up of spacers and by moving elements of the spacers, wherein, the platform is made up of two rigid elements connected to one another by a single link.

2. The structure according to claim 1, wherein the link is a pivoting link.

3. The structure according to claim 1, wherein the movable bases are arranged symmetrically.

4. The structure according to claim 1, wherein the moving elements of the spacers are linked by passive articulations to the articulated platform and to a movable base configured as linear actuators.

5. The structure according to claim 1, wherein the passive articulations are ball joints or universal joints.

6. The structure according to claim 1, wherein force sensors are arranged on the movable bases.

7. The structure according to claim 1, wherein the structure is a sub-millimetric size.

8. The structure according to claim 1, wherein the structure is actuated by piezoelectric Qi actuators.

9. The structure according to claim 1, wherein position sensors are arranged on the actuators.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0038] FIG. 1 is a graph of the layout of a first structure,

[0039] FIG. 2 shows a layout graph of a second structure,

[0040] FIG. 3 is an exemplary illustration of the first robotic structure of FIG. 1,

[0041] FIG. 4 is an exemplary illustration of the second robotic structure of FIG. 2,

[0042] FIG. 5 is another exemplary illustration of a structure with four spacers per arm,

[0043] FIG. 6 is exemplary illustration of a structure with one spacer with several branches,

[0044] FIG. 7 is an alternative of FIG. 2 where the actuators are arranged between two links.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0045] FIGS. 1 and 2 show layout graphs of two different robotic structures. These graphs reveal the topology of the structure of the robots and the various kinematic branches and loops. The conventions used for these graphs are: [0046] A: Liaison passive of the Universal (cardan) or spherical (ball joint) type. [0047] R: Passive link of the Rotational (pivot) type [0048] Qi: Actuator with 1 degree of freedom.

[0049] These examples of structures are part of the family of manipulators with six degrees of freedom and more of which certain alternatives are redundant in terms of actuation.

[0050] The exemplary illustration shown in FIG. 3 shows a robotic structure 1 with seven movable bases 2, an articulated platform 3 in two portions 30 and 31 connected by a passive connection 32. Each one of the two portions 30 and 31 is extended by a gripper 33; this gripper can be replaced with scissors, clamps or others. Three movable bases 21, 22, 23 are connected to the portion 31 of the articulated platform 3 by an arm 4 and, in the same way, three bases 24, 25, 26 are connected to the portion 32 of the articulated platform 3 by an arm 4.

[0051] Each one of the arms 4 is included of three spacers 40, 41 and 42, the first spacer 40 is connected to the second spacer 41 by a passive link 400, the second spacer 41 is connected to the third spacer 42 by a passive link 410. The passive link 400 can be of the spherical type and the connection 410 of the universal type.

[0052] Qi actuators are arranged on the spacers 40.

[0053] The movements of the portions 30 and 31 of the articulated platform 3 as well as the relative movement between the two portions of the platform are controlled by the movements of the various arms 4. The opening and/or the closing of the grippers 33 is obtained by the displacement of the arms as well as their position and their orientation.

[0054] The exemplary illustration shown in FIG. 4 shows a robotic structure 1 that is substantially identical to the preceding one except that it includes eight movable bases 2 instead of seven which makes for a robot that is redundant in actuation.

[0055] Here four bases 21, 22, 23, 24 are connected to the portion 31 of the articulated platform 3 by an arm 4 and, in the same way, four bases 25, 26, 27, 28 are connected to the portion 32 of the articulated platform 3 by an arm 4.

[0056] Each one of the arms 4 is formed of three spacers 40, 41 and 42, the first spacer 40 is connected to the second spacer 41 by a passive connection 400, the second spacer 41 is connected to the third spacer 42 by a passive connection 410. The passive connection 400 can be of the spherical type and the connection 410 of the universal type.

[0057] Qi actuators are arranged on the spacers 40.

[0058] The movements of the portions 30 and 31 of the articulated platform 3 as well as the relative movement between the two portions of the platform are controlled by the movements of the various arms 4. In the example shown in FIG. 5, each arm 4 is included of four spacers 40, 41, 42, 43 connected by three articulations 400, 410, 430. The actuators are controlled by a control 6. This structure makes it possible to use connections that are simpler to carry out therefore less expensive which still being more precise and offering a greater range of displacement.

[0059] FIG. 6 shows a structure where the arms 4 include a spacer 44 with several branches 440, 441, 442. Here the spacer 44 has three branches but it could have two or more of them. This structure is simpler because it uses fewer actuators, here two actuators with three degrees of freedom at least Q1, Q2 and an actuator with at least one degree of freedom Q7.

[0060] In the alternative of FIG. 7, the actuators Qi are arranged between the two passive links 400 and 410.