CN112659099B - Local two-degree-of-freedom rigid-flexible coupling bionic robot waist joint - Google Patents

Abstract

The invention discloses a local two-degree-of-freedom rigid-flexible coupling bionic robot waist joint which comprises four parallel units, wherein the four parallel units are overlapped from bottom to top and respectively comprise a first parallel unit, a second parallel unit, a third parallel unit and a fourth parallel unit from bottom to top, the first parallel mechanism unit and the fourth parallel mechanism unit have the same structure, and the second parallel mechanism unit and the third parallel mechanism unit have the same structure; a flexible shared platform is arranged between every two adjacent parallel units of the four parallel units, a flexible fixed platform is arranged at the bottom end of the first parallel unit, a flexible movable platform is arranged at the top end of the fourth parallel unit, a rigid central branch, a flexible constraint branch and artificial muscles are arranged between the two adjacent platforms, the artificial muscles are uniformly distributed along the circumferential direction, and the head end and the tail end of each artificial muscle are vertically hinged with the two adjacent platforms respectively; the invention has high simulation and good application market prospect.

Description

A local two-degree-of-freedom rigid-soft coupled bionic robot waist joint

technical field

The invention relates to the technical field of a humanoid robot, in particular to a waist joint of a local two-degree-of-freedom rigid-soft coupling bionic robot.

Background technique

The main function of the waist joint of the human body is to connect the lower limbs with the trunk. Its function is not only to provide rotational freedom, but also to feel the force between the trunk and the lower limbs. For bionic robots, although the series mechanism has a large working space, it often has problems such as high cumulative error and poor load capacity. Therefore, the parallel mechanism has become the first choice for waist joint bionics. After searching the existing related technical documents, it is found that a parallel mechanism with three transfers and one shift is proposed in the invention patent CN101695838A, which reduces the cumulative error and improves the load capacity compared with other series mechanisms; the invention patent CN108393872A proposes a parallel mechanism The parallel unit coupling mechanism increases the flexibility of the mechanism and the working space. However, the above-mentioned robot joints are all rigid joints, and there is still a certain gap in the structure and performance of the human waist joint with rigid-soft coupling and motion perception.

SUMMARY OF THE INVENTION

The invention provides a waist joint of a local two-degree-of-freedom rigid-soft coupled bionic robot, which solves the shortcomings of the existing bionic robot's poor flexibility and lack of force perception capability.

For solving the above-mentioned technical problems, the technical scheme adopted in the present invention is:

A local two-degree-of-freedom rigid-soft coupled bionic robot waist joint, comprising four parallel units superimposed from bottom to top, characterized in that: the four parallel units are respectively a first parallel unit and a second parallel unit from bottom to top , the third parallel unit, the fourth parallel unit, the first parallel mechanism unit has the same structure as the fourth parallel mechanism unit, the second parallel mechanism unit has the same structure as the third parallel mechanism unit; the four parallel units are adjacent to each other. A flexible shared platform is arranged between the two, a flexible fixed platform is arranged at the bottom of the first parallel unit, a flexible moving platform is arranged at the top of the fourth parallel unit, and a rigid center branch, a flexible constraint branch, The artificial muscle is evenly distributed along the circumferential direction, and both ends of the artificial muscle are vertically hinged with two adjacent platforms respectively.

A further improvement of the technical solution of the present invention is that: the flexible fixed platform includes three force-sensing branches a, one end of the three force-sensing branches a is connected to each other by a flexible hinge, the three force-sensing branches a are spaced 120° from each other, and the other end is connected by a hinge Connect the transfer platform, the force sensing branch a is provided with a strain gauge inside, and the flexible moving platform has the same structure as the flexible fixed platform.

A further improvement of the technical solution of the present invention is that the flexible shared platform includes a flexible shared platform a arranged between the first parallel unit and the second parallel unit, and a flexible shared platform a arranged between the second parallel unit and the third parallel unit. A flexible shared platform b, and a flexible shared platform c disposed between the third parallel unit and the fourth parallel unit.

A further improvement of the technical solution of the present invention is that: the flexible shared platform a includes six identical force-sensing branches b, one end of every two force-sensing branches b is connected to each other through a flexible hinge; the other end of every three force-sensing branches b is connected to each other through a hinge , the six force-sensing branches b form a spindle shape, and springs are arranged between the upper and lower ends of the flexible shared platform a for buffering.

A further improvement of the technical solution of the present invention is that a rigid center branch a, a flexible restraint branch a and an artificial muscle a are arranged between the flexible fixed platform and the flexible shared platform a, and a rigid center is arranged between the flexible shared platform a and the flexible shared platform b Branch b, flexible restraint branch b and artificial muscle b, rigid central branch c, flexible restraint branch c and artificial muscle c are set between flexible shared platform b and flexible shared platform c, and rigid central branch c is set between flexible shared platform c and flexible moving platform The central branch d, the flexible restraint branch d, and the artificial muscle d.

A further improvement of the technical solution of the present invention is that the rigid central branch a includes a first Hooker hinge, a second Hooker hinge and a fifth connecting rod, and the first Hooker hinge and the second Hooker hinge are respectively connected to the fifth connecting rod. The connecting rods are connected in series up and down, the flexible restraint branch a includes two connecting rods, namely a first connecting rod and a second connecting rod, one end of the first connecting rod is connected with the flexible fixed platform through a first rotating pair, and the other end is connected with the first connecting rod The two links are connected by a second rotation pair, and the other end of the second link is connected to the flexible shared platform a through a third rotation pair. The rigid center branch b, the rigid center branch c, and the rigid center branch d are all connected to the rigid center The branch a is the same, and the structures of the flexible restraint branch b, the flexible restraint branch c, and the flexible restraint branch d are all the same as the structure of the flexible restraint branch a.

Owing to having adopted the above-mentioned technical scheme, the technical progress that the present invention obtains is:

The bionic waist joint is composed of a flexible platform, which integrates motion and force sensing functions. Four local two-degree-of-freedom parallel units are combined into an eight-degree-of-freedom joint. Increasing the flexibility of the mechanism can realize more complex simulation behaviors and replace the traditional simple structure. Mechanical waist joints, bionic robot waist joints are composed of rigid branches, flexible branches and software drives, which make them have high fidelity and have good market application prospects.

Description of drawings

Fig. 1 is a three-dimensional schematic diagram of the overall structure;

2 is a schematic perspective view of a first parallel unit;

3 is a schematic perspective view of the deflection of the first parallel unit;

4 is a schematic perspective view of a second parallel unit;

5 is a three-dimensional schematic diagram of a flexible fixed platform;

6 is a three-dimensional schematic diagram of a flexible shared platform;

FIG. 7 is a schematic perspective view of a rigid center branch;

Among them, 010, flexible fixed platform, 011, force sensing branch a, 012, strain gauge, 013, transfer platform, 014, flexible hinge, 020, flexible shared platform a, 021, force sensing branch b, 022, strain gauge, 023, spring, 024, flexible hinge, 030, flexible shared platform b, 040, flexible shared platform c, 050, flexible moving platform, 060, flexible constraint branch a, 061, first rotation pair, 062, first link, 063, the second rotation pair, 064, the second link, 065, the third rotation pair, 070, the flexible restraint branch b, 080, the flexible restraint branch c, 090, the flexible restraint branch d, 100, the rigid center branch a, 101 , the first hook hinge, 102, the fifth link, 103, the second hook hinge, 110, the rigid central branch b, 120, the rigid central branch c, 130, the rigid central branch d, 140, the artificial muscle a, 150 , artificial muscle b, 160, artificial muscle c, 170, artificial muscle d.

Detailed ways

A local two-degree-of-freedom rigid-soft coupled bionic robot waist joint, comprising four parallel units superimposed from bottom to top, the four parallel units from bottom to top are a first parallel unit, a second parallel unit, a third parallel unit, The fourth parallel unit, the first parallel mechanism unit has the same structure as the fourth parallel mechanism unit, and the second parallel mechanism unit has the same structure as the third parallel mechanism unit; a flexible shared platform is arranged between each adjacent two of the four parallel units, respectively. It is a flexible shared platform a, a flexible shared platform b, and a flexible shared platform c. The bottom end of the first parallel unit is provided with a flexible fixed platform 010. The flexible fixed platform 010 includes three force-sensing branches a, and one end of the three force-sensing branches a passes through. The flexible hinges are connected to each other, the three force-sensing branches a are spaced 120° apart from each other, and the other end is connected to the transfer platform through hinges. The force-sensing branch a is internally provided with a strain gauge 012, and the strain gauge 012 is used to measure the force on the sensing branch, The flexible moving platform has the same structure as the flexible fixed platform; the top of the fourth parallel unit is provided with a flexible moving platform 050 with the same structure as the flexible fixed platform 010, and a rigid central branch a and a flexible constraint are arranged between the flexible fixed platform 010 and the flexible shared platform a. A rigid neutral branch b, a flexible constraint branch b and an artificial muscle b are set between the branch a and the artificial muscle a, the flexible shared platform a and the flexible shared platform b, and the rigid central branch c is set between the flexible shared platform b and the flexible shared platform c040 , a flexible constraint branch c and an artificial muscle c, a rigid central branch d, a flexible constraint branch d and an artificial muscle d are set between the flexible shared platform c and the flexible moving platform d, and the rigid central branch and flexible constraint are arranged between two adjacent platforms. The branches and artificial muscles are connected to form a local two-degree-of-freedom parallel joint, and the entire rigid-soft coupled bionic robot waist joint is an eight-degree-of-freedom joint, wherein the rigid center branch a includes the first Hooker hinge 101, the second Hooker hinge 103 and the fifth joint. The rod 102, the first Hook hinge 101 and the second Hook hinge 103 are connected in series with the fifth connecting rod 102 up and down respectively, and the flexible restraint branch a includes two connecting rods, namely the first connecting rod 062 and the second connecting rod 064 , one end of the first link 062 is connected with the flexible fixed platform 010 through the first rotating pair 061, the other end is connected with the second link 064 through the second rotating pair 063, and the other end of the second link 064 is connected through the third The rotating pair 065 is connected to the flexible shared platform a, and the rigid central branch b, the rigid central branch c, and the rigid central branch d have the same structure as the rigid central branch a.

The flexible sharing platform includes a flexible sharing platform a arranged between the first parallel unit and the second parallel unit, a flexible sharing platform b arranged between the second parallel unit and the third parallel unit, and a flexible sharing platform b arranged between the second parallel unit and the third parallel unit. The flexible shared platform c between the three parallel units and the fourth parallel unit, the three flexible shared platforms have the same structure, the specific flexible shared platform a includes six identical force-sensing branches b, and one end of each two force-sensing branches b passes through a flexible hinge Connected to each other; the other ends of every three force-sensing branches b are connected to each other by hinges, and the six force-sensing branches b form a spindle shape, and springs are provided between the upper and lower ends of the flexible shared platform a for buffering.

The internal mechanisms of the four parallel units of the bionic robot waist joint are roughly the same. In the first parallel mechanism unit, the flexible fixed platform 010 and the adjacent flexible shared platform a pass through three flexible constraint branches a, rigid central branch a, and three sets of artificial muscles. a connection. The flexible restraint branch 060 passes through a first link 062 and a second link 064. One end of the first link 062 is connected to the flexible fixed platform 010 through a first rotation pair 061, and the other end is connected to the second link 064 through a second rotation. The pair 063 is connected, the other end of the second link 064 is connected to the flexible shared platform a through the third rotating pair 065, the fifth link 102 on the rigid central branch a is connected to the flexible fixed platform 010 through the first Hooke hinge 101, It is connected with the flexible shared platform a through the second Hooke hinge 103; one end of the artificial muscle a is hinged with the flexible fixed platform 010, and the other end is hinged with the flexible shared platform a. The structures of the flexible restraint branch b, the flexible restraint branch c, and the flexible restraint branch d are all It has the same structure as the flexible constraint branch a.

Claims (5)

1. The utility model provides a just soft coupling bionic robot waist joint of local two degrees of freedom, includes that four parallel unit are formed by supreme stack from bottom to top, its characterized in that: the four parallel units are respectively a first parallel unit, a second parallel unit, a third parallel unit and a fourth parallel unit from bottom to top, the first parallel mechanism unit and the fourth parallel mechanism unit have the same structure, and the second parallel mechanism unit and the third parallel mechanism unit have the same structure; a flexible shared platform is arranged between every two adjacent four parallel units, a flexible fixed platform (010) is arranged at the bottom end of the first parallel unit, a flexible movable platform (050) is arranged at the top end of the fourth parallel unit, a rigid central branch, a flexible constraint branch and artificial muscles are arranged between every two adjacent platforms, the artificial muscles are uniformly distributed along the circumferential direction, and the head end and the tail end of each artificial muscle are vertically hinged with the two adjacent platforms respectively; the flexible shared platform comprises a flexible shared platform a (020) arranged between the first parallel unit and the second parallel unit, a flexible shared platform b (030) arranged between the second parallel unit and the third parallel unit, and a flexible shared platform c (040) arranged between the third parallel unit and the fourth parallel unit; the flexible shared platform a (020) comprises six identical force sensing branches b (021), and one end of each two force sensing branches b (021) is connected with each other through a flexible hinge (024); the other ends of every three force induction branches b (021) are mutually connected through a hinge; the rigid central branch comprises a rigid central branch a (100), a rigid central branch c (120) and a rigid central branch d (130), the rigid central branch a (100) comprises a first Hooke hinge (101), a second Hooke hinge (103) and a fifth connecting rod (102), the first Hooke hinge (101) and the second Hooke hinge (103) are respectively connected with the fifth connecting rod (102) in series up and down, and the structures of the rigid central branch b (110), the rigid central branch c (120) and the rigid central branch d (130) are the same as those of the rigid central branch a (100).

2. The waist joint of the local two-degree-of-freedom rigid-flexible coupling bionic robot as claimed in claim 1, wherein: the flexible fixed platform (010) comprises three force sensing branches a (011), one ends of the three force sensing branches a (011) are connected with each other through a flexible hinge (014), the three force sensing branches a (011) are separated by 120 degrees, the other ends of the three force sensing branches are connected with a switching platform (013) through hinges, a strain gauge (012) is arranged inside the force sensing branches a (011), and the flexible movable platform (050) is identical to the flexible fixed platform (010) in structure.

3. The local two-degree-of-freedom rigid-soft coupling bionic robot waist joint as claimed in claim 1, wherein: six force sensing branches b (021) form a spindle shape, and a spring (023) is arranged between the upper end and the lower end of the flexible shared platform a (020) for buffering.

4. The local two-degree-of-freedom rigid-soft coupling bionic robot waist joint as claimed in claim 1, wherein: a rigid central branch a (100), a flexible constraint branch a (060) and an artificial muscle a (140) are arranged between the flexible fixed platform (010) and the flexible shared platform a (020), a rigid central branch b (110), a flexible constraint branch b (070) and an artificial muscle b (150) are arranged between the flexible shared platform a (020) and the flexible shared platform b (030), a rigid central branch c (120), a flexible constraint branch c (080) and an artificial muscle c (160) are arranged between the flexible shared platform b (030) and the flexible shared platform c (040), and a rigid central branch d (130), a flexible constraint branch d (090) and an artificial muscle d (170) are arranged between the flexible shared platform c (040) and the flexible movable platform (050).

5. The local two-degree-of-freedom rigid-flexible coupling bionic robot waist joint as claimed in claim 4, characterized in that: the flexible constraint branch a (060) comprises two connecting rods, namely a first connecting rod (062) and a second connecting rod (064), one end of the first connecting rod (062) is connected with the flexible fixed platform (010) through a first revolute pair (061), the other end of the first connecting rod is connected with the second connecting rod (064) through a second revolute pair (063), the other end of the second connecting rod (064) is connected with the flexible shared platform a through a third revolute pair (065), and the structures of the flexible constraint branch b (070), the flexible constraint branch c (080) and the flexible constraint branch d (090) are the same as the structure of the flexible constraint branch a (060).

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