CN100354068C

CN100354068C - Four freedom parallel robot mechanism with passive bound branch

Info

Publication number: CN100354068C
Application number: CNB2005100522604A
Authority: CN
Inventors: 路懿
Original assignee: Yanshan University
Current assignee: Yanshan University
Priority date: 2005-02-06
Filing date: 2005-02-06
Publication date: 2007-12-12
Anticipated expiration: 2025-02-06
Also published as: CN1644312A

Abstract

The invention belongs to the field of robot and machinery manufacturing. The invention provides a novel four-degree-of-freedom parallel mechanism with passive restraint branches, which contains two different specific structures of passive restraint branches. This kind of mechanism can be used as a parallel robot to realize one movement and three different forms of rotation along the passively constrained branch axis. In addition to the characteristics of high rigidity and high load capacity of the parallel mechanism, it also has the characteristics of only axial force on the drive branch, large ratio of working space to mechanism volume, relatively simple mechanism, symmetrical structure, high precision, low cost and easy manufacture. The invention can design space parallel robots, parallel machine tools, micro robots, sensor elements and the like for various purposes.

Description

Has the passive bound branch four-freedom parallel connection robot mechanism

Technical field

The present invention relates to robot and mechanical manufacturing field.

Background technology

For ease of explanation, divide number with n (n=1,2,3,4,6) expression, represent the ball pivot in the sub-chain, universal hinge, moving sets, revolute pair respectively with alphabetical S, T, P, R, the sub-chain structure is represented in their combination.Driving branches into the motion branch that contains drive unit, and passive bound branch is not for containing the motion branch of drive unit.

Parallel robot has that mechanism's rigidity is big, and bearing capacity is strong, and end mass is light, and inertia is little, and site error such as does not accumulate at characteristics, is complementary relationship with the serial machine people on using.In recent years, lower-mobility (free degree is less than 6) parallel robot mechanism has become robot and has made the focus of area research, existing three-freedom parallel robot mechanism kind is more relatively, 3-RPS mechanism such as the Hunt proposition, the Delta mechanism that Pierrot proposes, the 3-TPT mechanism that Tsai proposes, obtain United States Patent (USP) (USANo.5656905), 3-RRR mechanism and 3-PRR mechanism that Gosselin proposes, the novel freedom degree parallel connection travel mechanism that Huang Zhen etc. propose obtains Chinese patent (CN 1311083A).The four-freedom parallel connection robot mechanism kind relatively seldom, a kind of four-freedom parallel connection robot mechanisms of proposition and a kind of two such as Wang Jingsong in 2000 move two is changeed four-axial parallel machine tool structure, obtain Chinese patent (CN 1267586A and CN 1267582A) respectively, yellow very proposition of calendar year 2001 3-TRT/SPS four-freedom parallel mechanism, obtain Chinese patent (CN 1306899A), yellow field in 2003 proposes the four-freedom hybrid robot and obtains Chinese patent (CN1439492A).The four-freedom parallel mechanism kind is not to illustrate that they are inessential less, and is on the contrary, the industrial demand that this type of mechanism is had broader applications.Compare advantage such as that the lower-mobility parallel institution has relatively is simple in structure, easy control with the Stewart six degree of freedom 6-SPS parallel institution of extensive use.But the lower-mobility parallel institution drives branch revolute pair is arranged, be easy to generate moment of flexure and shearing, very unfavorable to drive unit and mechanism's proper motion.

Summary of the invention

The object of the present invention is to provide a kind of linear drives branch only be subjected to the kinematic accuracy of axial force high have a passive bound branch four-freedom parallel connection robot mechanism.It is simple relatively that this invention has mechanism, symmetrical configuration, and working space is relatively large, drives branch and is not subjected to characteristics such as moment of flexure and shearing, can be implemented in three dimensions and move and three rotations along axial one of passive bound branch.Each SPS in this invention drives branch an isolated degree of freedom around its axis rotation, but it does not influence motion of mechanism character, can stop SPS to drive branch's rotation with very little flexible constraint power, so after ignoring the isolated degree of freedom of SPS driving branch, the present invention still is a four-degree-of-freedom.

This have a passive bound branch four-freedom parallel connection robot mechanism, four linear drives branches and a passive bound branch by pedestal 1, upper mounting plate 4 and connection pedestal 1 and upper mounting plate 4 are formed, it is characterized in that: four linear drives sub-chain structures are identical, be symmetrical distribution, kinematic constraint branch is positioned at the center; There is ball pair 2 at linear drives branch two ends, and the centre has one to drive moving sets 3, constitute SPS cascaded structure branch, drive moving sets 3 axis and overlap with ball pivot 2 centers, drive moving sets 3 and are made up of hydraulic pressure or electro-mechanical driving device; The kinematic constraint branched structure is divided into two kinds: first kind of passive bound branch constitutes PS cascaded structure branch by a moving sets and a ball pivot, moving sets is made up of cover 5 and ball pivot input bar 6, it is vertical with upper mounting plate 4 to overlap 5 axis, overlaps 5 upper ends and quadrangle upper mounting plate 4 centers are connected; Ball pivot take-off lever 7 is connected with quadrangle pedestal 1 center; Second kind of passive bound branch is by a revolute pair, a moving sets and a universal hinge constitute RPT cascaded structure branch, revolute pair is by revolute pair input bar 8, rotating shaft 9 and revolute pair take-off lever 10 are formed, revolute pair input bar 8 is connected with upper mounting plate 4 centers, the axis of rotating shaft 9 and upper mounting plate 4 plane parallel, revolute pair take-off lever 10 unites two into one with the moving sets cover, mobile auxiliary bond axle and universal hinge input bar 11 unite two into one, revolute pair rotating shaft 9 and universal hinge trunnion axis 12 spatial vertical, universal hinge vertical axis 13 are rotated with pedestal 1 central vertical and are connected.

The pedestal 1 of these two kinds of novel four-freedom parallel mechanisms and upper mounting plate 4 can be respectively rectangle or square, but can not be square simultaneously, in order to avoid mechanism is unusual; Four linear drives branches are distributed in four angular vertexs of rectangle, and passive bound branch is positioned at the center of rectangle; Driving the straight line mobile drive deivce that moving sets 3 is made up of hydraulic pressure or motor and ball screw spiral pair constitutes.

Description of drawings

Fig. 1 has passive bound branch PS four-freedom parallel mechanism;

Fig. 2 has passive bound branch RPT four-freedom parallel mechanism.

In Fig. 1, Fig. 2,1. pedestal, 2. ball pivot, 3. driving moving sets, 4. upper mounting plate, 5. moving sets cover, 6. mobile countershaft and ball pivot input bar, 7. ball pivot take-off lever, 8. revolute pair input bar, 9. revolute pair rotating shaft, 10. revolute pair take-off lever and mobile auxiliary bond cover, 11. mobile auxiliary bond axle and universal hinge input bar, 12. universal hinge trunnion axis, 13. universal hinge take-off levers.

The specific embodiment

Embodiment 1

Accompanying drawing 1 is an embodiment disclosed by the invention, this have a passive bound branch PS four-freedom parallel mechanism, comprise pedestal 1, upper mounting plate 4, reach four linear drives branches and a passive bound branch composition of connecting pedestal 1 and upper mounting plate 4, pedestal 1 and upper mounting plate 4 are respectively square and rectangle.The kinematic chain structure of four linear drives branches is identical, is distributed in four angular vertex places of pedestal 1 and upper mounting plate 4, and there is ball pivot 2 at linear drives branch two ends, and the centre has one to drive moving sets 3, drives moving sets 3 axis and overlaps with ball pivot 2 centers.Passive bound branch is positioned at rectangular centre, it has a moving sets and a ball pivot to constitute PS cascaded structure branch, moving sets is made up of moving sets cover 5 and ball pivot input bar 6, and moving sets cover 5 is connected with upper mounting plate 4 central vertical, and ball pivot take-off lever 7 is connected with pedestal 1 center.Driving moving sets 3 is made of the straight line mobile drive deivce that hydraulic linear mobile drive deivce or motor and screw pair constitute.

Embodiment 2

Accompanying drawing 2 is another embodiment disclosed by the invention, this have a passive bound branch RPT four-freedom parallel mechanism, comprise pedestal 1, upper mounting plate 4, reach four linear drives branches and a passive bound branch composition of connecting pedestal 1 and upper mounting plate 4, pedestal 1 and upper mounting plate 4 are respectively rectangle and square.The kinematic chain structure of four linear drives branches is identical, is distributed in four angular vertex places of pedestal 1 and upper mounting plate 4, and there is ball pivot 2 at linear drives branch two ends, and the centre has one to drive moving sets 3, drives moving sets 3 axis and overlaps with ball pivot 2 centers.Passive bound branch is positioned at rectangular centre, it constitutes RPT cascaded structure branch by a revolute pair, a moving sets and a universal hinge, revolute pair input bar 8 is connected with upper mounting plate 4 centers, revolute pair rotating shaft 9 and upper mounting plate 4 plane parallel, revolute pair take-off lever and moving sets cover 10 unite two into one, mobile auxiliary bond axle 11 unites two into one with universal hinge input bar, turns auxiliary shaft 9 and universal hinge trunnion axis 12 spatial vertical, and universal hinge vertical axis 13 rotates with pedestal 1 central vertical and connects.Driving moving sets 3 is made of the straight line mobile drive deivce that hydraulic linear mobile drive deivce or motor and screw pair constitute.

These two kinds novel contain kinematic constraint branch four-freedom parallel mechanism except that have that parallel institution rigidity is big, carrying is high, working space is big and characteristics such as symmetrical configuration, owing to only adopt ball pair and moving sets, therefore also have the branch of driving be not subjected to moment of flexure and shearing, mechanism relative simple compact, be easy to make and install and characteristics such as kinematic accuracy height.Passive bound branch contains two kinds of different concrete structures, and the passive bound branch of every kind of structure all makes the motion of upper mounting plate 4 lose two frees degree.First kind of parallel institution can be implemented in three dimensions and move along axial one of passive bound branch, around a rotation of passive bound branch axis, around with two rotations of this axis normal axle.Second kind of parallel institution can be implemented in three dimensions and move along axial one of passive bound branch, around a rotation of rotating auxiliary spindle 9, around two rotations of universal hinge trunnion axis 12 and vertical axis 13.Can design spatial parallel device people, parallel machine, jiggle robot and the sensor element etc. of various uses with these two kinds of novel four-freedom parallel mechanisms.

Claims

1. A four-degree-of-freedom parallel robot mechanism with passively constrained branches, including a base (1), an upper platform (4), and four linear drive branches connecting the base (1) and the upper platform (4) and a passive Constraint branches, the base (1) and upper platform (4) are rectangles or squares respectively, but they cannot be squares at the same time, the passive constraint branches are located in the center of the rectangle, and it is characterized in that the kinematic chain structure of the four linear drive branches is the same, distributed in At the vertices of the four corners of the base (1) and the upper platform (4), there are spherical joints (2) at both ends of the linear drive branch, and a driving movement pair (3) in the middle, and the axis of the driving movement pair (3) is connected to the spherical joint (2 ) center coincides; said passive restraint branch has a moving pair and a spherical hinge to form a PS series structure branch, and the moving pair is composed of a moving pair sleeve (5) and a spherical hinge input rod (6), and the moving pair sleeve (5) and The center of the upper platform (4) is fixed vertically, and the center of the spherical hinge output rod (7) is fixedly connected with the base (1).

2. A four-degree-of-freedom parallel robot mechanism with passively constrained branches, including a base (1), an upper platform (4), and four linear drive branches connecting the base (1) and the upper platform (4) and a passive Constraint branches, the base (1) and upper platform (4) are rectangles or squares respectively, but they cannot be squares at the same time, the passive constraint branches are located in the center of the rectangle, and it is characterized in that the kinematic chain structure of the four linear drive branches is the same, distributed in At the vertices of the four corners of the base (1) and the upper platform (4), there are spherical joints (2) at both ends of the linear drive branch, and a driving movement pair (3) in the middle, and the axis of the driving movement pair (3) is connected to the spherical joint (2 ) centers overlap; said passive restraint branch is composed of a rotating pair, a moving pair and a universal hinge to form the RPT series structure branch, the rotating pair input rod (8) is fixedly connected with the center of the upper platform (4), and the rotating pair rotating shaft ( 9) Parallel to the plane of the upper platform (4), the rotating auxiliary output rod and the moving auxiliary sleeve (10) are combined into one, the moving auxiliary key shaft (11) is combined with the universal hinge input rod, and the rotating auxiliary shaft (9 ) is perpendicular to the universal hinge horizontal axis (12) in space, and the universal hinge vertical axis (13) is vertically rotated connected with the center of the base (1).

3. The four-degree-of-freedom parallel robot mechanism with passive restraint branches according to claim 1 or 2, characterized in that: the driving movement pair (3) is composed of a hydraulic linear movement drive device.