CN110434838A - A kind of five degree of freedom broad sense sphere parallel mechanism - Google Patents

Abstract

The present invention is a five-degree-of-freedom generalized spherical parallel mechanism, which includes a dynamic platform, a static platform and branch chains; It is composed of A-type connecting rod and B-type connecting rod. The A-type connecting rod is a spherical connecting rod, and the B-type connecting rod is a double-spherical connecting rod. The distances between them are equal, all B-rods coincide to form the fixed sphere center of the generalized spherical parallel mechanism, and all the B-rods’ moving spheres coincide to form the moving sphere center of the generalized spherical parallel mechanism; the degree of freedom of the moving platform around the sphere center is 3 spherical motion, the center of the moving sphere moves around the center of the sphere with a degree of freedom of 2; the branch chains of the five-degree-of-freedom generalized spherical parallel mechanism have two types, namely the AABA type branch chain and the ABAA type branch chain; the AABA type There are two branched chains and three ABAA type branched chains. The institution is more flexible and adaptable.

Description

A five-degree-of-freedom generalized spherical parallel mechanism

technical field

The invention relates to the field of mechanical engineering, in particular to a five-degree-of-freedom generalized spherical parallel mechanism.

Background technique

With the continuous development of the field of medical health and robotics, more and more health robots have entered people's field of vision. Health robots can not only help patients with joint injuries to perform rehabilitation exercises, but also can be used for sports training of athletes and joint correction of the elderly. Existing rehabilitation robots generally have the advantages of high rigidity, strong carrying capacity, and high flexibility. However, in view of the complexity of human joint motion, it is difficult to improve the fitting accuracy of rehabilitation robots and eliminate human-computer interaction force by using existing mechanisms. The mechanism design of health robots has encountered a large bottleneck. Taking the ankle joint rehabilitation robot as an example, most of its configurations are based on the dexterous eye mechanism (three-degree-of-freedom spherical parallel mechanism), which has a dynamic platform, a static platform and three branch chains, each of which has two A spherical connecting rod and three revolving pairs, and the center axis of rotation of all revolving pairs of the mechanism will intersect with a point in space, the human ankle joint is equivalent to a standard spherical pair, and the human ankle joint is one of the most complicated joints in the human body. , including the tibia, fibula, talus, scaphoid and calcaneus, etc., if simply simplified into a standard spherical pair, a large human-computer interaction force will be generated. To solve such problems, it is very meaningful to propose a new mechanism that can fully fit the ankle joint motion.

Contents of the invention

Aiming at the deficiencies of the existing technology, the technical problem to be solved by the present invention is to provide a five-degree-of-freedom generalized spherical parallel mechanism, and to provide a theoretical basis for the design of a new human ankle joint health robot. The mechanism has a degree of freedom and movement space that is compatible with the human ankle joint, and fully considers the spherical misalignment problem caused by the existence of the ankle joint talus (the current design of ankle joint rehabilitation robots regards the ankle joint as a standard spherical motion, but this The relative motion between the ankle tibia and the talus is not a standard spherical motion, and there is a serious misalignment problem); the mechanism has sufficient flexibility, simplicity, dexterity, changeability, and strong adaptability.

The technical solution of the present invention to solve the technical problem is to provide a five-degree-of-freedom generalized spherical parallel mechanism, including a dynamic platform, a static platform and a branch chain; the parallel mechanism has two non-overlapping rotating centers, respectively Center and moving ball center, and the distance between the two ball centers is an adjustable fixed value, characterized in that the parallel mechanism as a whole is regarded as a moving platform orbiting the ball center to do a spherical motion with 3 degrees of freedom, and the moving ball center revolves The center of the fixed sphere performs spherical motion with 2 degrees of freedom; the branch chain of the five-degree-of-freedom generalized spherical parallel mechanism has two types, which are the AABA branch chain used to control the spherical motion of the moving sphere center around the fixed sphere center and the branch chain used for ABAA-type branch chains that control the spherical motion of the braking platform around the center of the ball; there are two AABA-type branch chains, and three ABAA-type branch chains; all branch chains are composed of A-type connecting rods and B-type connecting rods, and A-type The connecting rod is a spherical connecting rod, and the axis lines of the holes at both ends intersect at one point. The B-type connecting rod is a double-spherical connecting rod, that is, the B-type connecting rod has two generalized spherical centers, which are respectively the fixed center of the B rod. With the center of the moving ball of the B rod, the line segment connected by the two generalized ball centers of the B-type connecting rod is defined as the "double-center line segment", and the length of the "double-center line segment" is the "double-center distance". In the same parallel mechanism The "double center distance" of all B-type connecting rods must be equal, and the "double-center line segments" of all B-type connecting rods are always completely coincident during the movement, that is, the fixed ball centers of all B rods coincide to form the fixed ball of the generalized spherical parallel mechanism center, and all the moving ball centers of the B rods coincide to form the moving ball center of the generalized spherical parallel mechanism.

Compared with prior art, the beneficial effect of the present invention is:

The present invention proposes the configuration of a five-degree-of-freedom generalized spherical parallel mechanism for the first time. The mechanism has two rotating centers, one is a fixed center and the other is a moving center. The moving center rotates in two degrees of freedom relative to the fixed center, and the moving platform It rotates with three degrees of freedom around the center of the sphere, has five branch chains, and forms rotational pairs between adjacent branch chains. The mechanism not only has the characteristics of strong bearing capacity of parallel mechanism and high dexterity of movement, but also can fit the movement of part of series mechanism.

The parallel mechanism of the present invention can be applied to the design of the ankle joint of the human health robot, which not only conforms to the movement law of the human ankle joint, has high dexterity, more accurate and reasonable fitting, but also has low manufacturing cost, simple structure, convenient control and effective It solves the problem of poor interactive performance of the traditional three-degree-of-freedom spherical parallel mechanism for fitting ankle joint motion. The five-degree-of-freedom generalized spherical parallel mechanism has higher fitting accuracy, but requires a large number of motors and relatively high cost, especially suitable for It is used in occasions that require high precision, such as high-end markets.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of an embodiment of the present invention.

Fig. 2 is a schematic diagram of the partial structure of No. 1 and No. 5 branches of an embodiment of the present invention.

Fig. 3 is a schematic diagram of partial structures of No. 2, No. 3 and No. 4 branches of an embodiment of the present invention.

In the figure, 1, No. 1 branch chain; 11, No. 1 branch chain No. 1 connecting rod; 12, No. 1 branch chain No. 2 connecting rod; 13, No. 1 branch chain No. 3 connecting rod; 14. No. 1 branch chain No. 4 No. connecting rod; 15. No. 1 branch chain No. 1 shaft; 16. No. 1 branch chain No. 2 shaft; 17. No. 1 branch chain No. 3 shaft; 18. No. 1 branch chain No. 4 shaft; 19. No. 1 branch chain No. 5 shaft; 2. No. 2 branch chain; 21. No. 2 branch chain No. 1 connecting rod; 22. No. 2 branch chain No. 2 connecting rod; 23. No. 2 branch chain No. 3 connecting rod; 24. No. 2 branch chain No. 4 connecting rod; 25. No. 1 shaft of No. 2 branch chain; 26. No. 2 shaft of No. 2 branch chain; 27. No. 3 shaft of No. 2 branch chain; 28. No. 4 shaft of No. 2 branch chain; 29. No. 2 branch Chain No. 5 shaft; 3. No. 3 branch chain; 31. No. 3 branch chain No. 1 connecting rod; 32. No. 3 branch chain No. 2 connecting rod; 33. No. 3 branch chain No. 3 connecting rod; 34. No. 3 branch Chain No. 4 connecting rod; 35. No. 1 shaft of No. 3 branch chain; 36. No. 2 shaft of No. 3 branch chain; 37. No. 3 shaft of No. 3 branch chain; 38. No. 4 shaft of No. 3 branch chain; 39. No. 3 branch chain Branch chain No. 5 shaft; 4, No. 4 branch chain; 41, No. 4 branch chain No. 1 connecting rod; 42, No. 4 branch chain No. 2 connecting rod; 43, No. 4 branch chain No. 3 connecting rod; 44, No. 4 branch chain Branch chain No. 4 connecting rod; 45. No. 4 branch chain No. 1 shaft; 46. No. 4 branch chain No. 2 shaft; 47. No. 4 branch chain No. 3 shaft; 48. No. 4 branch chain No. 4 shaft; 49. No. 5 branch chain shaft; 5, No. 5 branch chain; 51, No. 5 branch chain No. 1 connecting rod; 52, No. 5 branch chain No. 2 connecting rod; 53, No. 5 branch chain No. 3 connecting rod; 54, 5 No. 4 connecting rod of No. 5 branch chain; 55. No. 1 shaft of No. 5 branch chain; 56. No. 2 shaft of No. 5 branch chain; 57. No. 3 shaft of No. 5 branch chain; 58. No. 4 shaft of No. 5 branch chain; 59. No. 5 branch chain No. 5 shaft; 6. Static platform; 7. Dynamic platform;

Detailed ways

Specific examples of the present invention are given below. The specific embodiments are only used to further describe the present invention in detail, and do not limit the protection scope of the present application.

The five-degree-of-freedom generalized spherical parallel mechanism of the present invention includes a dynamic platform, a static platform, and a branch chain; the parallel mechanism has two non-overlapping rotating sphere centers, which are respectively a fixed sphere center and a moving sphere center, and between the two sphere centers The distance is an adjustable fixed value, the parallel mechanism as a whole is regarded as a spherical motion with a degree of freedom of 3 for the moving platform around the center of the sphere, and a spherical motion with a degree of freedom of 2 for the center of the moving sphere around the center of the fixed sphere, so the generalized spherical parallel mechanism With 5 degrees of freedom, it can fully adapt to and match the degree of freedom of the ankle joint; the branch chain of the 5-degree-of-freedom generalized spherical parallel mechanism has two types, namely AABA type branch chain and ABAA type branch chain, and the AABA type branch chain mainly controls braking. The spherical movement of the center of the sphere around the center of the static sphere, the ABAA branch chain mainly controls the spherical movement of the moving platform around the center of the sphere; all branch chains of the generalized spherical parallel mechanism are composed of A-type connecting rods and B-type connecting rods, and the A-type connecting rods The rod is a spherical connecting rod, and the axis lines of the holes at both ends intersect at one point, while the B-type connecting rod is a generalized spherical connecting rod. The B-type connecting rod can be regarded as a double-spherical connecting rod in a parallel mechanism, that is, B The connecting rod has two generalized spherical centers, which are the fixed spherical center of the B rod and the moving spherical center of the B rod. The axis lines of the holes at both ends of the B-type connecting rod do not necessarily intersect in space. Here, the definition of the B-type connecting rod The line segment connected by two generalized spherical centers is a "double-center line segment", and the length of the "double-center line segment" is "double-center distance". The generalized spherical parallel mechanism requires the " The "double-center distance" must be equal, and the "double-center line segments" of all B-type connecting rods are always completely coincident during the movement process, that is, the fixed ball centers of all B-bars coincide to form the fixed-ball center of the generalized spherical parallel mechanism, and all B-bars move the ball Center coincides to form the moving ball center of the generalized spherical parallel mechanism.

A more reasonable equivalent model for the movement of the human ankle joint is: the fitting connection between the lower surface of the tibia and the upper surface of the talus is regarded as a spherical pair, the fitting connection between the lower surface of the talus and the upper surface of the calcaneus is regarded as a spherical pair, and the two spherical pairs The distance between the centers of the spheres is a constant, which is determined by the relevant size parameters of the user's talus.

The five-degree-of-freedom generalized spherical parallel mechanism is applied to the ankle joint rehabilitation robot. According to the parameters of the patient's talus, the average relative rotation sphere center between the patient's tibia and talus, and the average relative rotation sphere center between the talus and calcaneus can be determined. , and the distance parameter between the two centers can be calculated. According to this parameter, the "double center distance" of the generalized spherical parallel mechanism can be determined, so as to realize the average relative rotation between the center of the mechanism and the talus and calcaneus during the motion fitting process. The center of the ball coincides, and the center of the moving ball of the mechanism always coincides with the average relative rotation of the tibia and the talus. Compared with the traditional three-degree-of-freedom spherical parallel mechanism (smart eye mechanism), the generalized spherical parallel mechanism is more accurate in fitting the ankle joint movement , reasonable, and the fitting effect has been significantly improved.

In this application, the distance between the two sphere centers (fixed sphere center and moving sphere center) is an adjustable fixed value, which means that the distance dimension can be arbitrarily selected during the mechanism configuration design process, and is not limited by the size of other components, but , Once the size is determined and manufactured completely, it cannot be changed. The dimensions of the A-type connecting rods given in the configuration are not all the same, and the dimensions of the B-type connecting rods are not necessarily all the same, but the "double center distance" of all B-type connecting rods must be equal.

Example

This embodiment provides a five-degree-of-freedom generalized spherical parallel mechanism configuration design scheme for ankle joint rehabilitation training, including a static platform 6, a dynamic platform 7, and three ABAA type branch chains (No. 1 branch chain 1, No. 2 branch chain Branch chain 2, No. 3 branch chain 3) and two AABA-type branch chains (No. 4 branch chain 4, No. 5 branch chain 5); the static platform 6 and the dynamic platform 7 are spherical connecting rods with five rotating pairs, That is, the axes of the five side-end through-holes meet at one point (the intersection of the axis-lines of the five side-end through-holes of the moving platform is the intersection of all B-bar moving ball centers, that is, the generalized spherical parallel mechanism The center of the moving ball; the intersection point of the axis lines of the five side-end through holes of the static platform is the intersection point of the fixed ball centers of all B-bars, that is, the fixed ball center of the generalized spherical parallel mechanism); the No. 1 branch chain 1 is an ABAA type branch chain, wherein, the No. 1 branch chain No. 4 connecting rod 14 is an A-type connecting rod, the No. 1 branch chain No. 3 connecting rod 13 is a B-type connecting rod, and the No. 1 branch chain No. 2 connecting rod 12 is an A-type connecting rod. The No. 1 connecting rod 11 of the No. 1 branch chain is an A-type connecting rod; the No. 1 branch chain hole of the moving platform 7 and the upper end hole of the No. 1 branch chain No. 4 connecting rod 14 are connected and matched through the No. 1 branch chain No. 5 shaft 19 Form a rotating pair; the lower end hole of the No. 4 connecting rod 14 of the No. 1 branch chain and the upper end hole of the No. 3 connecting rod 13 of the No. 1 branch chain are connected through the No. 1 branch No. 4 shaft 18 to form a rotating pair; the No. 1 branch chain The lower end hole of No. 3 connecting rod 13 and the upper end hole of No. 1 branch chain No. 2 connecting rod 12 are connected and matched by No. 1 branch chain No. 3 shaft 17 to form a rotating pair; the lower end hole of No. 1 branch chain No. 2 connecting rod 12 The upper end hole of the No. 1 connecting rod 11 of the No. 1 branch chain is connected and matched with the No. 2 shaft 16 of the No. 1 branch chain to form a rotating pair; the lower end hole of the No. 1 connecting rod 11 of the No. 1 branch chain and the No. 1 branch of the static platform The chain holes are connected and matched by the No. 1 branch chain No. 1 shaft 15 to form a rotating pair;

The second branch chain 2 is an ABAA type branch chain, wherein, the No. 2 branch chain No. 4 connecting rod 24 is an A-type connecting rod, the No. Bar 22 is an A-type connecting rod, and the No. 2 branch chain No. 1 connecting rod 21 is an A-type connecting rod; No. 5 branch chain No. 5 shaft 29 is connected and matched to form a rotating pair; the lower end hole of No. 2 branch chain No. 4 connecting rod 24 and the upper end hole of No. 2 branch chain No. 3 connecting rod 23 are connected through No. 2 branch chain No. 4 shaft 28 Cooperate to form a rotating pair; the lower end hole of the No. 2 branch chain No. 3 connecting rod 23 and the upper end hole of the No. 2 branch chain No. 2 connecting rod 22 are connected and matched through the No. 2 branch chain No. 3 shaft 27 to form a rotating pair; the No. 2 branch The lower end hole of the No. 2 connecting rod 22 of the chain and the upper end hole of the No. 1 connecting rod 21 of the No. 2 branch chain are connected and matched by the No. 2 shaft 26 of the No. 2 branch chain to form a rotating pair; the lower end of the No. 1 connecting rod 21 of the No. 2 branch chain The No. 2 branch chain hole of the hole and the static platform 6 is connected and matched by the No. 2 branch chain No. 1 shaft 25 to form a rotating pair;

The third branch chain 3 is an ABAA type branch chain, wherein, the No. 3 branch chain No. 4 connecting rod 34 is an A-type connecting rod, the No. Rod 32 is an A-type connecting rod, and No. 3 branch chain No. 1 connecting rod 31 is an A-type connecting rod; No. 3 branch chain hole of moving platform 7 and the upper end hole of No. 3 branch chain No. 4 connecting rod 34 pass No. 3 The No. 5 shaft 39 of the branch chain is connected and matched to form a rotating pair; the lower end hole of the No. 4 connecting rod 34 of the No. 3 branch chain and the upper end hole of the No. 3 connecting rod 33 of the No. 3 branch chain are connected and matched through the No. 4 shaft 38 of the No. 3 branch chain Form a revolving pair; the lower end hole of No. 3 branch chain No. 3 connecting rod 33 and the upper end hole of No. 3 branch chain No. 2 connecting rod 32 are connected and matched through No. 3 branch chain No. 3 shaft 37 to form a revolving pair; No. 3 branch chain The lower hole of the second connecting rod 32 and the upper hole of the No. 1 connecting rod 31 of the No. 3 branch chain are connected and matched by the No. 2 shaft 36 of the No. 3 branch chain to form a rotating pair; the lower hole of the No. 1 connecting rod 31 of the No. 3 branch chain Connect and cooperate with the No. 3 branch chain hole of the static platform 6 through the No. 3 branch chain No. 1 shaft 35 to form a rotating pair;

The No. 4 branch chain 4 is an AABA type branch chain, wherein the No. 4 branch chain No. 4 connecting rod 44 is an A-type connecting rod, the No. 4 branch chain No. 3 connecting rod 43 is an A-type connecting rod, and the No. 4 branch chain No. 2 connecting rod is an A-type connecting rod. Rod 42 is B-type connecting rod, and No. 4 branch chain No. 1 connecting rod 41 is A-type connecting rod; No. 4 branch chain hole of moving platform 7 and the upper end hole of No. 4 branch chain No. The No. 5 shaft 49 of the branch chain is connected and matched to form a rotating pair; the lower end hole of the No. 4 connecting rod 44 of the No. 4 branch chain and the upper end hole of the No. 3 connecting rod 43 of the No. 4 branch chain are connected and matched through the No. 4 branch chain No. 4 shaft 48 Form a revolving pair; the lower end hole of the No. 3 connecting rod 43 of the No. 4 branch chain and the upper end hole of the No. 2 connecting rod 42 of the No. 4 branch chain are connected and matched through the No. 4 branch No. 3 shaft 47 to form a revolving pair; the No. 4 branch chain The lower end hole of No. 2 connecting rod 42 and the upper end hole of No. 4 branch chain No. 1 connecting rod 41 are connected and matched by No. 4 branch chain No. 2 shaft 46 to form a rotating pair; the lower end hole of No. 4 branch chain No. 1 connecting rod 41 Connect and cooperate with the No. 4 branch chain hole of the static platform 6 through the No. 4 branch chain No. 1 shaft 45 to form a rotating pair;

The fifth branch chain 5 is an AABA type branch chain, wherein, the No. Rod 52 is a B-type connecting rod, and No. 5 branch chain No. 1 connecting rod 51 is an A-type connecting rod; No. 5 branch chain hole of moving platform 7 and the upper end hole of No. 5 branch chain No. Branch chain No. 5 shaft 59 is connected and matched to form a rotating pair; the lower end hole of No. 5 branch chain No. 4 connecting rod 54 and the upper end hole of No. 5 branch chain No. 3 connecting rod 53 are connected and matched through No. 5 branch No. 4 shaft 58 Form a revolving pair; the lower end hole of the No. 3 connecting rod 53 of the fifth branch chain and the upper end hole of the No. 2 connecting rod 52 of the No. 5 branch chain are connected and cooperated through the No. 3 shaft 57 of the fifth branch chain to form a revolving pair; the No. 5 branch chain The lower end hole of No. 2 connecting rod 52 and the upper end hole of No. 1 connecting rod 51 of No. 5 branch chain are connected and matched by No. 5 branch chain No. 2 shaft 56 to form a rotating pair; the lower end hole of No. 5 branch chain No. 1 connecting rod 51 Connect and cooperate with the No. 5 branch chain hole of the static platform 6 through the No. 5 branch chain No. 1 shaft 55 to form a rotating pair;

No. 1 branch chain No. 1 shaft 15, No. 1 branch chain No. 2 shaft 16, No. 1 branch chain No. 3 shaft 17, No. 2 branch chain No. 1 shaft 25, No. 2 branch chain No. 2 shaft 26, No. 2 branch chain 3 No. shaft 27, No. 3 branch chain No. 1 shaft 35, No. 3 branch chain No. 2 shaft 36, No. 3 branch chain No. 3 shaft 37, No. 4 branch chain No. 1 shaft 45, No. 4 branch chain No. 2 shaft 46, No. 5 The axis line spaces of No. 1 shaft 55 of No. 5 branch chain and No. 2 shaft 56 of No. 5 branch chain meet at one point, which is the center of alignment of the generalized spherical parallel mechanism; No. 4 shaft 18 of No. 1 branch chain with five degrees of freedom , No. 1 branch chain No. 5 shaft 19, No. 2 branch chain No. 4 shaft 28, No. 2 branch chain No. 5 shaft 29, No. 3 branch chain No. 4 shaft 38, No. 3 branch chain No. 5 shaft 39, No. 4 branch chain No. 3 shaft 47, No. 4 branch chain No. 4 shaft 48, No. 4 branch chain No. 5 shaft 49, No. 5 branch chain No. 3 shaft 57, No. 5 branch chain No. 4 shaft 58, No. 5 branch chain No. 5 shaft 59 The axis spaces meet at one point, which is the moving center of the generalized spherical parallel mechanism.

In this embodiment, three ABAA-type branch chains are adjacent, and two AABA-type branch chains are adjacent. The direction from the platform to the static platform is A, A, B, and A-type connecting rods.

The working principle of the five-degree-of-freedom generalized spherical parallel mechanism is as follows:

Taking a standing ankle joint health robot as an example, the kinematic characteristics of a 5-DOF generalized spherical parallel mechanism are illustrated. Five servo motors respectively drive No. 1 branch chain No. 1 connecting rod 11, No. 2 branch chain No. 1 connecting rod 21, No. 3 branch chain No. 1 connecting rod 31, No. 4 branch chain No. 1 connecting rod 41 and No. 5 branch chain The first connecting rod 51 rotates relative to the static platform 6, which is to control the five angle inputs of the robot; the first connecting rod 41 of the fourth branch chain and the first connecting rod 51 of the fifth branch chain respectively drive the second connecting rod of the fourth branch chain 42 and No. 5 branch chain No. 2 connecting rod 52, because static platform 6, No. 4 branch chain No. 1 connecting rod 41 and No. 5 branch chain No. 1 connecting rod 51 are A-type spherical connecting rods, so limit B-type connecting rod No. 4 branch chain No. 2 connecting rod 42 and No. 5 branch chain No. 2 connecting rod 52's "B bar fixed ball center" coincide; because the "double heart distance" of all B-type connecting rods of the generalized spherical parallel mechanism is equal, and the four The No. 3 connecting rod 43 of the No. 4 branch chain, the No. 4 connecting rod 44 of the No. 4 branch chain, the moving platform 7, the No. 4 connecting rod 54 of the No. 5 branch chain, and the No. 3 connecting rod 53 of the No. 5 branch chain are connected in sequence and are all A Spherical connecting rods, so the B-type connecting rod No. 4 branch chain No. 2 connecting rod 42 and No. 5 branch chain No. 2 connecting rod 52’s "B-rod moving ball center" coincide. At this time, the No. 4 branch chain No. 2 connecting rod The motion between 42 and No. 5 branch chain No. 2 connecting rod 52 is the rotation around the overlapped "double heart segment"; No. connecting rod 42, No. 5 branch chain No. 1 connecting rod 51 and No. 5 branch chain No. 2 connecting rod 52 form a spherical five-bar mechanism, and the degree of freedom of the spherical five-bar mechanism is 2, that is, No. 4 branch chain No. 1 chain The input angle between the rod 41 and the No. 1 connecting rod 51 of the No. 5 branch determines the spatial position of the "moving ball center" of the 5-DOF generalized spherical parallel mechanism, and at the same time shows that the moving ball center has 2 degrees of freedom; No. 1 branch chain 1 No. connecting rod 11, No. 1 branch chain No. 2 connecting rod 12, No. 2 branch chain No. 1 connecting rod 21, No. 2 branch chain No. 2 connecting rod 22, No. 3 branch chain No. 1 connecting rod 31, No. 3 branch chain 2 No. connecting rod 32 is the A-type spherical connecting rod, so it has limited the No. 3 connecting rod 13 of the No. 1 branch chain of the B-type connecting rod, the No. 3 connecting rod 23 of the No. 2 branch chain, and the No. 3 connecting rod 33 of the No. 3 branch chain. "B-rod fixed ball center" coincides with "B-bar fixed ball center" of No. 4 branch chain No. 2 connecting rod 42 and No. 5 branch chain No. 2 connecting rod 52; The No. 4 connecting rod 24 of the branch chain, the No. 4 connecting rod 34 of the No. 3 branch chain and the moving platform 7 are all A-type spherical connecting rods, which limit the number of B-type connecting rods. No. 3 connecting rod 23, No. 3 branch chain No. 3 connecting rod 33's "B bar moving ball center" and No. 4 branch chain No. 2 connecting rod 42, No. 5 branch chain No. 2 connecting rod 52 "B bar moving ball center" " coincide, so the spatial motion of No. 1 branch chain No. 3 connecting rod 13, No. 2 branch chain No. 3 connecting rod 23, and No. 3 branch chain No. 3 connecting rod 33 is the rotation around the "double heart line segment"; if the No. 4 branch The input of No. 1 connecting rod 41 of chain and No. 5 branch chain 51 is given, then the space pose of the "double-center line segment" of the generalized spherical parallel mechanism is fixed; at this time, the static platform 6 and No. 1 branch chain No. 1 connecting rod 11. No. 1 branch chain No. 2 connecting rod 12, No. 1 branch chain No. 3 connecting rod 13 form a spherical four-bar mechanism, static platform 6, No. 2 branch chain No. 1 connecting rod 21, No. 2 branch chain No. 2 connecting rod 22 , No. 2 branch chain and No. 3 connecting rod 23 Spherical four-bar mechanism, static platform 6, No. 3 branch chain No. 1 connecting rod 31, No. 3 branch chain No. 2 connecting rod 32, No. 3 branch chain No. 3 connecting rod 33 form a spherical four-bar mechanism, and each group of four bars Each mechanism has 1 degree of freedom, and there are 3 degrees of freedom in total; No. 1 branch chain No. 1 connecting rod 11, No. 2 branch chain No. 1 connecting rod 21, No. No. 2 connecting rod 12, No. 2 branch chain No. 2 connecting rod 22, No. 3 branch chain No. 2 connecting rod 32 drive No. 1 branch chain No. 3 connecting rod 13, No. 2 branch chain No. 3 connecting rod 23, No. 3 branch chain No. three connecting rod 33 rotates around the overlapping "double-center line segment"; No. three connecting rod 13 of No. two branch chain, No. three connecting rod 23 of No. two branch chain, No. three connecting rod 33 of No. three branch chain pass through No. one branch chain four No. connecting rod 14, No. 2 branch chain No. 4 connecting rod 24, No. 3 branch chain No. 4 connecting rod 34 drive the moving platform 7 to rotate around the "moving ball center". At this time, No. 4 branch chain No. 3 connecting rod 43, No. 4 The No. 4 connecting rod 44 of the branch chain, the No. 3 connecting rod 53 of the No. 5 branch chain, and the No. 4 connecting rod 54 of the No. 5 branch chain only participate in limiting the coincidence of the "B-bar moving center" of the generalized spherical parallel mechanism, and do not affect the rotation of the moving platform 7. The spherical movement of "moving the center of the ball";

To sum up, the rotation angle input of the first connecting rod 41 of the No. 4 branch chain and the No. 1 connecting rod 51 of the No. 5 branch chain controls the spherical motion of the "moving ball center" around the "fixed ball center", which has two degrees of freedom. When this mechanism is used in the design of the human ankle joint rehabilitation robot, it mainly fits the relative motion between the tibia and the talus of the user's ankle joint; 21. The rotation angle input of No. 3 branch chain No. 1 connecting rod 31 controls the spherical motion of the braking platform 7 around the "moving ball center", which has 3 degrees of freedom. When this mechanism is used in the design of human ankle joint rehabilitation robots, its main Fitting the relative motion between the talus and the calcaneus of the user's ankle joint; in summary, the overall mechanism has 5 degrees of freedom, so the generalized spherical parallel mechanism can more accurately fit the ankle joint motion, greatly reducing the The human-computer interaction force caused by the model.

What is not mentioned in the present invention is applicable to the prior art.

Claims (2)

1. a kind of five degree of freedom broad sense sphere parallel mechanism, including moving platform, silent flatform and branch；There are two parallel institution tools The rotation centre of sphere not being overlapped respectively determines the centre of sphere and the dynamic centre of sphere, and the distance between two centre ofs sphere are an adjustable definite value, are owned Branch is made of A type connecting rod and Type B connecting rod, and A type connecting rod is spherical surface connecting rod, and Type B connecting rod is double centre of sphere spherical surface connecting rods, same The distance between two centre ofs sphere of all Type B connecting rods in parallel institution are equal, and two of all Type B connecting rods in motion process The line segment that the centre of sphere is connected to is completely coincident always, i.e., all B bars determine the centre of sphere and be overlapped composition broad sense sphere parallel mechanism to determine ball The heart, and all B bars move the dynamic centre of sphere that the centre of sphere is overlapped composition broad sense sphere parallel mechanism；It is characterized in that,

Parallel institution is collectively regarded as the moving platform moving centre of sphere and does the spheric motion that freedom degree is 3, and the dynamic centre of sphere does freedom around the centre of sphere is determined The spheric motion that degree is 2；The branch of five degree of freedom broad sense sphere parallel mechanism has two types, respectively for controlling detent ball AABA type branch and the ABAA type branch of spheric motion for control the moving platform moving centre of sphere of the heart around the spheric motion for determining the centre of sphere Chain；AABA type branch has two, and ABAA type branch has three.

2. parallel institution according to claim 1, which is characterized in that three ABAA type branches are adjacent, two AABA type branch Chain is adjacent.