A kind of flexible joint variation rigidity mechanism
Technical field
The invention belongs to robotic technology fields, in particular to a kind of flexible joint variation rigidity mechanism.
Background technique
With the development of robot technology, the scope of application of robot is widened.Robot is isolated by original factory
Area gradually comes into human society.Robot will not only cooperate at work with the mankind, or even sometimes need to connect with the mankind
Touching.Deepen with human-computer interaction degree, the uncertain factor of external environment is also increasing, and working environment becomes complicated, at any time may be used
It can collide with the object in the environment of surrounding, this proposes very high requirement to the safety of robot.Traditional industry
Robot is rigid, and on the basis of using a large amount of sensor and complicated control algolithm, is also able to achieve certain submissive
Control.But precise kinetic model foundation difficulty is big, the resolution ratio of sensor and the response speed of system are to Shared control
Effect produces very big influence.Moreover, should also have certain passive safety when robot and the mankind work together, to protect
Card, which either encounters emergency case in some sensor failures, can protect robot and the mankind to escape injury.Meanwhile for rigidity
Bigger joint of robot, when being impacted or when colliding object, the energy that part is hit is not obtained rationally
Utilization, cause energy consumption bigger.When robot is in location circumstances, often with object or human contact, frequent start-stop,
The big joint of robot response speed of rigidity is slow.
Domestic scholar attempts to look for a kind of reasonable approach and protects the safety of the mankind, and effectively improves low efficiency
And the problems such as starting low-response.The method that most of scholar proposes is to design a kind of compliant mechanism of variable rigidity, in power
The compliant mechanism of this variable rigidity is added between source and output end, can be adjusted according to rigidity of the use occasion to joint
It is whole, guarantee safety.When robot and external object collide, joint stiffness becomes very low, reduces collision damage.Right
When status requirement is high, the height for becoming joint stiffness guarantees position precision.In addition, this mechanism can be in joint motions
A kind of power storage device is served as, stores energy to when impact in joint, it can be by energy in next movement
It is restored in robot system, reduces the consumption of energy, accelerate the starting speed of robot.
The principle of the variation rigidity mechanism introduced in joint at this stage has following several: antagonism principle, lever principle, change
Spring parameter, electromagnetic principle, pneumatic muscles etc..The variation rigidity joint designed based on the above principles can realize the variation rigidity in joint
It is required that but all existing corresponding insufficient.Variation rigidity joint based on the design of antagonism principle is required when carrying out stiffness tuning
Energy ratio is larger, and partial joint coupling is strong, and load capacity is poor;Based on lever principle design variation rigidity joint by dynamic stiffness
Curve is not ideal enough, and the size of partial joint is bigger;Based on the variation rigidity joint for changing spring parameter design, size compares
Greatly, rigidity precision is low;Vulnerable to circuital current influence of fluctuations, rigidity stability is poor in joint based on electromagnetic principle design;It is based on
The variation rigidity joint of pneumatic muscles design, needs external cylinder, use scope is not wide.
Summary of the invention
The purpose of the present invention is to overcome the shortcomings of the existing technology and deficiency, provides a kind of flexible joint variation rigidity mechanism,
Solve above-mentioned load capacity is poor, stiffness tuning range is small, adjust rigidity energy consumption is high, coupling is strong, passive stiffness characteristics are poor, need
The problem of wanting external cylinder.
The purpose of the present invention is achieved through the following technical solutions: a kind of flexible joint variation rigidity mechanism, including input structure 1
With export structure 2, the input structure 1 is connected with about 2 export structure correspondence;The input structure 1 includes a pair of guide rods axis
11-1,11-2, a pair of guide rods 12-1,12-2, a pair of of compressed spring 13-1,13-2, a pair of spring mounting seat 14-1,14-2 and defeated
Enter plate 15;The export structure 2 includes a pair of of linear guide component 21-1,21-2, a pair of of set of rollers 22-1,22-2, a pair of of rolling
Sub- mounting rack 23-1,23-2, linear displacement transducer push rod 24, a pair of of rack gear 25-1,25-2, driven gear 26, driving gear
27, linear displacement transducer 28, output board 29 and multiple bearings, circlip and bolt;Described guide rod shaft 11-1,11-2 and bullet
Spring mounting base 14-1,14-2 is mounted on input board 15, and guide rod 12-1,12-2 are mounted on guide rod shaft 11-1,11-2, guide rod
Compressed spring 13-1,13-2, the linear guide component 21- are installed between 12-1,12-2 and spring mounting seat 14-1,14-2
1,21-2, linear displacement transducer 28 and driven gear 26 are separately mounted on output board 29, roller mounting rack 23-1,23-2 peace
On linear guide component 21-1,21-2, be separately installed on roller mounting rack 23-1,23-2 set of rollers 22-1,22-2 and
Rack gear 25-1,25-2, one end of linear displacement transducer push rod 24 are mounted on the corresponding roller mounting rack of driving gear 27, separately
One end is connected with the sliding block on linear displacement transducer 28, and driven gear 26 is mounted on driven gear shaft.
Preferably, 15 side of input board is connected with the power source of control position, and the input of variation rigidity mechanism is installed in the other side
Structure;Described guide rod shaft 11-1,11-2 and spring mounting seat 14-1,14-2 are symmetrically arranged on input board 15, are used
It is bolted and is fixed;Described guide rod 12-1,12-2 are to be arranged symmetrically, the pressure coaxially arranged with guide rod shaft 11-1,11-2
Contracting spring 13-1,13-2 and guide rod 12-1,12-2 and spring mounting seat 14-1,14-2 are arranged vertically, guide rod 12-1,12-2 and
Pass through the fixed relative position of protruding column, spring mounting seat 14-1,14-2 and compressed spring between compressed spring 13-1,13-2
13-1,13-2 pass through the fixed relative position of holding screw.
Preferably, output board 29 is plate-like, and one end is joint output, and the other end is equipped with export structure, and the straight line is led
Rail assembly 21-1,21-2, set of rollers 22-1,22-2, roller mounting rack 23-1,23-2 and rack gear 25-1,25-2 are all made of symmetrically
Arrangement is mounted on output board 29, and the linear displacement transducer 28 and the corresponding linear guide member parallel of driving gear 27 are put
It sets, the two is located at the two sides of output board 29, and driving gear 27 is connected with stiffness tuning motor;Driven gear 26 and driving tooth
Wheel 27 the number of teeth it is identical with modulus, between be intermeshed, two gears respectively with rack gear 25-1,25-2 engage.
Preferably, driven gear 26 is mounted on driven gear shaft, and axial restraint is realized using the shaft shoulder and circlip, described
Driven gear shaft is connected using bolt and output board 29.
Preferably, the guide rod 12-1,12-2, set of rollers 22-1,22-2, spring mounting seat 14-1,14-2, compressed spring
13-1,13-2, rack gear 25-1,25-2, linear guide component 21-1,21-2, roller mounting rack 23-1,23-2 arrange in pairs,
It is angled with diametrical direction, it is arranged symmetrically at " eight " shape.
Preferably, the initial position of guide rod 12-1,12-2 is parallel with linear guide component 21-1,21-2, set of rollers 22-1,
22-2 and guide rod 12-1,12-2 are tangent.
The invention adopts the above technical scheme, which has the following advantages:
1, the present invention is driven by train, realizes the synchronous backward displacement of sliding block.Based on lever principle, changes roller and lead
Amount of force is acted between bar.And on guide rod force position variation, send out active force to the arm of force of rotation center
Changing, effectively enhances the volume load capacity in joint, and stiffness tuning range is big.
2, the present invention is using roller and guide rod come transmission force, and the frictional force between roller and guide rod is small, the phase of both changes
When to position, required power it is small and, in the initial state, slide block guide rail and guide rod are parallel to each other, and mutual pressure is small.It is logical
Above-mentioned innovation is crossed, it is effective to realize that change rigidity energy consumption is small.
3, the present invention is individually to make the variation rigidity mechanism in robot variation rigidity joint, and position motors drive entire variation rigidity machine
Structure rotation adjusts the variation of rigidity motor driven roller position to change joint stiffness.At work, position control and stiffness reliability are only
Vertical, coupled problem is not present.
4, the present invention uses double guide rod structures of separate type.The existing variation rigidity joint using simple lever, by not Tongfang
To torque when, two springs all provide corresponding pulling force or pressure, and there are couplings between two springs.In the invention
Each guide rod and corresponding roller only just interact when bearing a certain side force square, guide rod and rolling when by another side force
It is separation between son, the coupling between two elastic elements can be released in this way, effectively simplified model.
5, the present invention using the size for changing active force and changes active force and diametric angle synergy, realizes
The good passive rigidity property of apery.The existing variation rigidity joint based on lever principle is not usually when by moment of face, lever
It is usually overlapped with diameter, the active force between lever and fulcrum and radial direction angle is 90 degree.When by moment of face,
Active force becomes larger, but active force and diametric angle change, so that effective arm reduces.The increase of active force and
The reduction of effective arm, so that joint is undesirable by dynamic stiffness effect.It is not parallel using guide rail and diametrical direction in the present invention
It places, makes active force between roller and guide rod and radial direction less than 90 degree in original state, when by external load,
The direction of active force and the angle of radial direction increase, and 90 degree are no more than close to 90 degree.Pass through active force and active force angle
Increase simultaneously, effectively realizes good passive rigidity property.
6, the present invention uses motor driven, does not need external cylinder.
Detailed description of the invention
Fig. 1 is overall structure figure of the present invention;
Fig. 2 is input structure structure chart of the invention;
Fig. 3 is export structure structure chart of the invention;
Fig. 4 is export structure right view of the invention;
Fig. 5 is the principle of the present invention figure.
Specific embodiment
Technical solution in the embodiment of the present invention that following will be combined with the drawings in the embodiments of the present invention carries out clear, complete
Ground description, it is clear that described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.Based on this
Embodiment in invention, every other reality obtained by those of ordinary skill in the art without making creative efforts
Example is applied, shall fall within the protection scope of the present invention.
In conjunction with Fig. 1, Fig. 2, Fig. 3, Fig. 4, a kind of flexible joint variation rigidity mechanism, including input structure 1 and export structure 2,
The input structure 1 is connected with about 2 export structure correspondence;The input structure 1 includes a pair of guide rods axis 11-1,11-2, one
To guide rod 12-1,12-2, a pair of of compressed spring 13-1,13-2, a pair of spring mounting seat 14-1,14-2 and input board 15;It is described
Export structure 2 includes a pair of of linear guide component 21-1,21-2, a pair of of set of rollers 22-1,22-2, a pair of of roller mounting rack 23-
1,23-2, linear displacement transducer push rod 24, a pair of of rack gear 25-1,25-2, driven gear 26, driving gear 27, straight-line displacement
Sensor 28, output board 29 and multiple bearings, circlip and bolt;Described guide rod shaft 11-1,11-2 and spring mounting seat 14-
1,14-2 is mounted on input board 15, and guide rod 12-1,12-2 are mounted on guide rod shaft 11-1,11-2, guide rod 12-1,12-2 and bullet
Compressed spring 13-1,13-2, the linear guide component 21-1,21-2, straight line position are installed between spring mounting base 14-1,14-2
Displacement sensor 28 and driven gear 26 are separately mounted on output board 29, and roller mounting rack 23-1,23-2 are mounted on linear guide
On component 21-1,21-2, set of rollers 22-1,22-2 and rack gear 25-1,25- are separately installed on roller mounting rack 23-1,23-2
2, one end of linear displacement transducer push rod 24 is mounted on the corresponding roller mounting rack of driving gear 27, the other end and straight line position
Sliding block on displacement sensor 28 is connected, and driven gear 26 is mounted on driven gear shaft.
15 side of input board is connected with the power source of control position, and variation rigidity mechanism input knot is installed in the other side
Structure;Described guide rod shaft 11-1,11-2 and spring mounting seat 14-1,14-2 are symmetrically arranged on input board 15, using spiral shell
It tethers to connect and be fixed;Described guide rod 12-1,12-2 are to be arranged symmetrically, the compression coaxially arranged with guide rod shaft 11-1,11-2
Spring 13-1,13-2 and guide rod 12-1,12-2 and spring mounting seat 14-1,14-2 are arranged vertically, guide rod 12-1,12-2 and pressure
Pass through the fixed relative position of protruding column, spring mounting seat 14-1,14-2 and compressed spring 13- between contracting spring 13-1,13-2
1,13-2 passes through the fixed relative position of holding screw.
The output board 29 is plate-like, and one end is joint output, and the other end is equipped with export structure, the linear guide group
Part 21-1,21-2, set of rollers 22-1,22-2, roller mounting rack 23-1,23-2 and rack gear 25-1,25-2 are all made of and are arranged symmetrically
It being mounted on output board 29, the linear displacement transducer 28 and the corresponding linear guide member parallel of driving gear 27 are placed,
The two is located at the two sides of output board 29, and driving gear 27 is connected with stiffness tuning motor;Driven gear 26 and driving gear
27 number of teeth is identical with modulus, between be intermeshed, two gears respectively with rack gear 25-1,25-2 engage.
The driven gear 26 is mounted on driven gear shaft, and axial restraint is realized using the shaft shoulder and circlip, it is described from
Movable gear shaft is connected using bolt and output board 29.
Above-mentioned installation connection relationship, which can be bolted, to be fixed, and driven gear 26 is mounted on driven gear shaft
On, bearing is housed between the two, driven gear 26 be free to rotate around driven gear shaft, and axial restraint uses the shaft shoulder and card
Spring is realized.Driving gear 27 is connected with tune rigidity motor, transmits power.Driven gear 26 and 27 number of teeth of driving gear and mould
Number it is equal, between be intermeshed.Two gears are engaged with rack gear 25 respectively, realize the synchronization action of sliding block to change the rigid of joint
Degree.When adjusting rigidity movement input, driven gear 26 and the intermeshing of driving gear 27 are rotated backward when having, and are driven and are engaged with
The movement of 25 reverse sync of rack gear, realizes the synchronization action of set of rollers, to change the rigidity in joint.
The guide rod 12-1,12-2, set of rollers 22-1,22-2, spring mounting seat 14-1,14-2, compressed spring 13-1,
13-2, rack gear 25-1,25-2, linear guide component 21-1,21-2, roller mounting rack 23-1,23-2 are arranged in pairs and diameter
Direction is angled, is arranged symmetrically at " eight " shape.
The initial position of described guide rod 12-1,12-2 are parallel with linear guide component 21-1,21-2, set of rollers 22-1,22-
2 and guide rod 12-1,12-2 it is tangent, the axial distance between input structure 1 and export structure 2 is determined by shell.Set of rollers
22 contact with guide rod 12 respectively.When original state, under the driving of train, the contact point between guide rod 12 respectively of set of rollers 22
It sets and changes, contact point moment keeps symmetrical position.The initial position of guide rod 12 is parallel with linear guide component 21 respectively,
Energy needed for drive train changes position of action point is small.
In conjunction with Fig. 5, the principle of the present invention are as follows:
Due to set of rollers 22 be always in the process of movement it is symmetrical, mainly illustrated here with set of rollers 22-1.Such as
Shown in Fig. 5, under the action of adjusting motor, train transmission is moved across, realizes that set of rollers 22-1 and 22-2 are close or separate
Initial position a realizes variation rigidity.When far from initial position a, centered on the rotation center of guide rod 12-1, guide rod 12-1-a
The arm of force of active force reduces between set of rollers 22-1-b, and the arm of force of spring force remains unchanged, using lever principle, by guide rod
Active force becomes larger between 12-1-a and set of rollers 22-1-b.Meanwhile when set of rollers 22-1-a moves to set of rollers 22-1-b, lead
Active force increases the arm of force of joint rotation center between bar 12-1-a and set of rollers 22-1-b.The above two o'clock has joint well
Load capacity.
It under the action of extraneous torque, deflects between input board 15 and output board 29, set of rollers 22-1-b is to guide rod
The active force of 12-1-a rotates guide rod 12-1-a, after the tilting design of guide rod 12-1-a rotates guide rod 12-1-a
The angle in direction and diameter O1O2 to the active force of set of rollers 22-1-c increases, so that guide rod 12-1-b is to set of rollers 22-1-c
Active force the effective arm of the rotation center in joint is increased, optimize the passive rigidity property in entire joint, can have
The buffering extraneous load of effect.
In the variation rigidity mechanism, double guide rod-double roller group structures, when by external loading torque, only one are used
It contacts with each other between side guide rod and roller, is separated from each other between other side guide rod and roller.Two compression bullets can be released in this way
Coupling between spring obtains better rigidity property and load capacity.It is symmetrical using two group guide rods and set of rollers simultaneously
The synchronization action of arrangement and set of rollers, realizes that positive and negative torque is consistent with the change curve of deflection angle with rigidity.
Its theoretical calculation is as follows:
As shown in figure 5, set of rollers position reaches the position 22-1-b by the mobile x of 22-1-a, overall stiffness is adjusted.By
After loading Text to the external world, deflection angle is β between input board 15 and output board 29.Power of the spring force Fs1 to rotation center O1
Arm is Ls1.F is active force of the set of rollers 22-1-c to guide rod 12-1-b, and the arm of force to O1 is L, then the size of F are as follows:
F=(Fs1 × Ls1)/L
Lr is radius when set of rollers 22-1-c is rotated where track, and σ 1 is the direction of F and the angle of O1O2.Then F
To the torque T of joint rotation center are as follows:
T=F × Lr × sin (β-σ 1)
Joint stiffness are as follows:
Kadj=dT/d β
It is moved by motor driven driving gear 27, by the transmitting of drive train, realizes the unidirectional same of the position of roller
Step variation, is adjusted the rigidity in joint.
Above to a kind of flexible joint variation rigidity mechanism provided by the present invention, it is described in detail, it is used herein
A specific example illustrates the principle and implementation of the invention, and the above embodiments are only used to help understand
Method and its core concept of the invention;At the same time, for those skilled in the art is having according to the thought of the present invention
There will be changes in body embodiment and application range, in conclusion the content of the present specification should not be construed as to the present invention
Limitation.