CN101804634B - Large-arm joint pneumatic balanced structure and optimization design method thereof - Google Patents

Abstract

The invention discloses a large-arm joint pneumatic balanced structure and an optimization design method thereof, wherein the optimization design method comprises the following steps of: determining the forms of a large-arm structure and a pneumatic support rod balanced structure; determining variables to be optimized in design; establishing a dynamic mathematical model of the mechanics parameters of the large-arm joint pneumatic balanced structure; establishing a constraint function and a target function; obtaining the comprehensive optimal solution of the structure by adopting a constraint optimization algorithm; and outputting an optimization design result and a movement simulation figure thereof. The invention takes the factors of installation space, transmission efficiency, the movement range of a large-arm joint, the balanced effect of a large-arm gravity moment and the like into account to obtain one comprehensive optimal solution.

Description

Large-arm joint pneumatic balanced structure and Optimization Design thereof

Technical field

The present invention relates to the robot field, relate in particular to the pneumatic balanced structure that is used for balancing machine human arm or the big arm shoulder joint of artificial limb place gravitational moment.

Background technology

At present, in the design of robot ' s arm structure or the big arm configuration of artificial limb, adopt various drives structure to realize that the front and back pendulum under the big arm load condition drives or the abduction driving.When robot arm or artificial limb arm being carried out the front and back pendulum drives or abduction when driving, certainly exist the problem that will overcome big arm shoulder joint place gravitational moment.The gravitational moment of big arm is big more, and it is just big more to drive the required driving moment of big arm.If a kind of large-arm joint weight torque balance structure is provided, the trimming moment of corresponding comparison near big arm gravitational moment just can be provided along with the variation of large-arm joint range of movement, thereby reduces the required driving moment of big arm motion.Because this balanced structure must be complementary with arm structure,, be the problem that those skilled in the art need solve again so how in limited structure space, realize optimum balance to big arm gravitational moment.

Summary of the invention

The objective of the invention is to invent a kind of large-arm joint pneumatic balanced structure and Optimization Design thereof for addressing the above problem.

For reaching above-mentioned purpose, large-arm joint pneumatic balanced structure of the present invention is a kind of space oscillating guidebar mechanism of evolution.This space oscillating guidebar mechanism by be fixed on last ball hinged support on the frame and following ball hinged support, the pneumatic support bar that shape bar and two ends are hinged on down ball hinged support respectively and turn shape bar one end that turns that is hinged on the ball hinged support is formed jointly; Turning the hinged of shape bar and pneumatic support bar also is ball-joint.

When turning that the shape bar moves back and forth or during the abduction swing, just driving arm and realize swing or abduction swing.Pneumatic support bar is telescopic variation along with the motion of big arm, and pneumatic support bar its thrust in telescopic process is constant substantially.No matter arm is swing or abduction swing, and the thrust of pneumatic support bar all can produce certain trimming moment to the gravitational moment of arm.

For reasonably designing the physical dimension of large-arm joint pneumatic balanced structure each several part, and select the thrust magnitude of suitable pneumatic support bar, so that manipulator or artificial limb obtain compact conformation, weight torque balance is effective, power consumption is little, motion actuated soon, the purpose of no movement interference, the present invention adopts Optimization Design, and its step is as follows:

1, determines choosing of design variable and other parameter

If the central point of last ball hinged support 1 is O, the central point of following ball hinged support 2 be D and D point O order under, the pneumatic support bar 4 ball pivot central point hinged with turning shape bar 3 is E, the last flex point that turns the shape bar is B, the following flex point that turns the shape bar is F, the P point place of the center of gravity of arm on the downward extended line of BF is when arm BF when initial position (that is: BF is in vertical) extended line that makes progress is A with crossing the horizontal intersection point of O point, when arm during at initial position the E point on short transverse, be fixed length AF apart from the O point, when arm during at initial position the P point on short transverse, be fixed length AP apart from the O point, when arm sees that it is fixed length AO that the P point departs from the O point in the horizontal direction in the front during at initial position, when arm sees that this balanced structure is about OD line symmetric arrangement in the side during at initial position, the distance that BF line and E are ordered is FE;

The pneumatic thrust value of getting pneumatic support bar is design variable x ₁(unit: N);

Get between O, D two central points is design variable x apart from OD length ₂(unit: mm);

Getting FE length is design variable x ₃(unit: mm);

Do not exceeding under the big arm configuration size situation, getting AF is maximum.

2, require to determine x according to specific design ₁, x ₂, x ₃, x ₄Span and carry out the initialization assignment;

3, in big arm scope of activities, set up the outer weighing apparatus moment M that balances about large-arm joint pneumatic balanced structure _Wp(unit: put gravitational moment M Nm), outward _Wz(unit: Nm), forward swing trimming moment M _Qp(unit: Nm) with forward swing gravitational moment M _Qz(unit: the dynamic mathematical models of mechanics parameter Nm) are as follows:

${\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="HSA00000014374500011.png,HSA00000014374500031.png"\; state="\{\{state\}\}">L</figure-callout>}}_1=\sqrt{{\mathrm{<figure-callout\; id="2"\; label="AF"\; filenames="HSA00000014374500011.png,HSA00000014374500041.png"\; state="\{\{state\}\}">AF</figure-callout>}}^2+{(\mathrm{AO}-x_3)}^2}\&CenterDot;\sin {\mathrm{\&gamma;}}_1/1000$

${\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HSA00000014374500011.png,HSA00000014374500041.png"\; state="\{\{state\}\}">L</figure-callout>}}_2=\sqrt{{\mathrm{<figure-callout\; id="2"\; label="AP"\; filenames="HSA00000014374500011.png,HSA00000014374500041.png"\; state="\{\{state\}\}">AP</figure-callout>}}^2+{\mathrm{AO}}^2}\&CenterDot;\sin ({\mathrm{\&theta;}}_1+{\mathrm{\&alpha;}}_1)/1000$

L ₃＝AF·sinγ ₂/1000

L ₄＝APsinα ₂/1000

M _wp＝x ₁·L ₁

M _wz＝m·g·L ₂

M _qp＝x ₁·L ₃

M _qz＝m·g·L ₄

Wherein: L ₁The balance arm of force (unit: m) when swinging for abduction;

L ₂Weight arm (unit: m) when swinging for abduction;

L ₃The balance arm of force (unit: m) during for swing;

L ₄Weight arm (unit: m) during for swing;

α ₁Be the outer pivot angle degree of big arm (unit: spend), independent variable;

γ ₁Being the ∠ OED (unit: spend) in front view, is variable at the volley, can be according to α ₁Reaching each parameter utilization geometry and the programming of trigonometric function knowledge tries to achieve;

${\mathrm{\&theta;}}_1=\&angle;\mathrm{OPA}=\mathrm{arctg}\left(\frac{\mathrm{AO}}{\mathrm{AP}}\right)$ (unit: degree), definite value;

α ₂Be big arm swing angle (unit: spend), independent variable;

γ ₂Being the ∠ OED (unit: spend) in lateral plan, is variable at the volley, can be according to α ₁Reaching each parameter utilization geometry and the programming of trigonometric function knowledge tries to achieve;

M is a big arm weight (unit: kg);

G is an acceleration of gravity;

4, the requirement of interference mutually not taking place according to the structure of the structure space of big arm and working space, pneumatic support bar during with performance, motion, determines that the constraint function of design variable is as follows:

g ₁(x)＝x ₁-500≤0

g ₂(x)＝100-x ₁≤0

g ₃(x)＝x ₂-150≤0

g ₄(x)＝90-x ₂≤0

g ₅(x)＝x ₃-OA≤0

g ₆(x)＝60-x ₃≤0

5, the maximum Danone of setting up the trimming moment that produces with big arm pneumatic support bar when forward and backward swing or the abduction swing and the difference absolute value of big arm gravitational moment is to minimum object function:

f ₁(x)＝max(abs(ΔM _1i))

f ₂(x)＝max(abs(ΔM _2i))

min?f(x)＝max(f ₁(x)，f ₂(x))

Δ M wherein _1i=M _Wpi-M _Wzi, the trimming moment that pneumatic support bar produces when representing the swing of big arm abduction and the numerical value of difference when diverse location of big arm gravitational moment, i=1......n;

Δ M _2i=M _Qpi-M _Qzi, the numerical value of difference when diverse location of the trimming moment that pneumatic support bar produces when representing big arm swing and big arm gravitational moment, i=1......n;

f ₁The trimming moment that pneumatic support bar produced when (x) the big arm abduction of expression was swung and the maximum of the difference absolute value of big arm gravitational moment;

f ₂(x) maximum of the trimming moment that pneumatic support bar produces during the big arm swing of expression and the difference absolute value of big arm gravitational moment;

F (x) is f ₁(x) and f ₂(x) maximum in is an object function, and results of optimum design is to make f (x) reach minimum,, makes that the maximum in the difference absolute value of the big arm trimming moment that pneumatic support bar produces when swing or abduction swing and big arm gravitational moment reaches minimum that is.

6, the computer program of working out optimal design according to the dynamic mathematical models and the object function of design variable, constraint function, arm mechanics parameter, and input computer moves, and adopts constrained optimal design algorithm to each design variable x ₁, x ₂, x ₃Be optimized calculating, until the optimal value that reaches expectation;

7, output Optimal design and calculation result and motion simulation figure thereof

The invention has the advantages that:

1. big arm has been adopted a kind of pneumatic balanced structure based on pneumatic support bar, but the gravitational moment of each position in the motion of the big arm of active balance, with the big arm that satisfies artificial limb or manipulator to the space compactness, weight torque balance is effective, driving moment is little, power consumption is low, the fluctuation of load is little, the motion actuated performance requirement that soon, can not move interference.

2. adopted Optimization Design, can obtain the parameter value of each best design variable fast according to the needs of different situations.

Description of drawings

1-accompanying drawing 5 illustrates one embodiment of the present of invention with reference to the accompanying drawings.

Fig. 1 is the principle schematic of large-arm joint pneumatic balanced structure, wherein Fig. 1 .a is the front view of big arm original state, Fig. 1 .b is the front view that the outer pendulum of big arm is held state level with both hands, and Fig. 1 .c is the side view of big arm original state, and Fig. 1 .d is the side view that big arm forward swing is held state level with both hands.

Ball hinged support 3--turns the pneumatic support bar 5--of shape bar 4--ball pivot under the last ball hinged support 2--of marginal data: 1--.

Fig. 2 is the motion simulation figure to design result, and O, D, E, F, B each point and the member thereof that has shown this structure principle during diverse location in the outer pendular motion process of big arm concerns.

Fig. 3 is the motion simulation figure to design result, and O, D, E, F each point and the member thereof that has shown this structure be the principle relation during diverse location in big arm forward swing motion process.

Fig. 4 is in the big arm motion process, the change curve of the remaining gravitational moment of big arm under the effect of this balanced structure.

Fig. 5 is an optimizer operation block diagram.

The specific embodiment

The principle of large-arm joint pneumatic balanced structure of the present invention as shown in Figure 1.

Large-arm joint pneumatic balanced structure of the present invention is a kind of space oscillating guidebar mechanism of evolution.By be fixed on last ball hinged support 1 on the frame and following ball hinged support 2, the pneumatic support bar 4 that shape bar 3, two ends be hinged on down ball hinged support 2 respectively and turn shape bar 3 one ends that turns that is hinged on the ball hinged support 1 is formed.Turning shape bar 3 is connected by ball pivot 5 with pneumatic support bar 4.

When turning that shape bar 3 moves back and forth or during the abduction swing, arm is just realized swing or abduction swing.Pneumatic support bar 4 is telescopic variation along with the motion change of big arm, and pneumatic support bar 4 its thrust in telescopic process is constant substantially.No matter arm is swing or abduction swing, and the thrust of pneumatic support bar 4 all can produce certain trimming moment to the gravitational moment of arm.

Below with instantiation and with reference to the description of drawings optimal design method.

Known conditions: the heavy m=10kg of arm, the P point place of the center of gravity of arm on the downward extended line of BF, the distance of arm P point ball hinged support 1 central point O on distance on the short transverse when initial position is AP=330mm, the distance of arm ball pivot 5 central point E ball hinged support 1 central point O on distance on the short transverse when initial position is AF=310mm, arm front when initial position sees that it is AO=98mm that the P point departs from the distance that O orders in the horizontal direction, the scope of activities of big arm is 0 °-90 ° of abduction swings, °-90 ° (that is: direction is opposite in swing-90, numerical value equates, can only calculate half scope).

At first, with the computer program of computer language to the dynamic mathematical models and the object function establishment optimal design of the design variable described in the foregoing invention content, constraint function, arm mechanics parameter, and the input computer moves.This Optimized Program has adopted complex to optimize algorithm.Disclosed method in " mechanical optimized design " middle chapter 5 that complex optimization algorithm has adopted publishing house of Tsing-Hua University to publish.The computer run step is shown in Fig. 5 flow chart.

As calculated, main optimal design result is:

1, the pneumatic thrust value of pneumatic support bar 4 is x ₁=399.9595N;

2, upward the centre-to-centre spacing OD length of ball hinged support 1 and following ball hinged support 2 is x ₂=91.8500mm;

3, be x apart from FE length between BF line and ball pivot 5 central point E ₃=60.0000mm;

4, object function is f (x)=8.4720Nm.

The motion simulation figure of design result such as Fig. 2, shown in Figure 3.O, D, E, F, B each point and the member thereof that has shown this structure among Fig. 2 principle during diverse location in the outer pendular motion process of big arm concerns.O, D, E, F each point and the member thereof that Fig. 3 has shown this structure be the principle relation during diverse location in big arm forward swing motion process.

In the big arm motion process, the change curve of the remaining gravitational moment of big arm as shown in Figure 4 under the effect of this balanced structure.

This large-arm joint pneumatic balanced structure can fall more than 70% the arm gravitational moment mean equilibrium that is operated in above-mentioned scope and state.

Claims (3)

1. large-arm joint pneumatic balanced structure, it is characterized in that, it is a kind of space oscillating guidebar mechanism of evolution, this space oscillating guidebar mechanism by be fixed on last ball hinged support on the frame and following ball hinged support, the pneumatic support bar that shape bar and two ends are hinged on down ball hinged support respectively and turn shape bar one end that turns that is hinged on the ball hinged support is formed jointly; Turning the hinged of shape bar and pneumatic support bar also is ball-joint;

If the central point of last ball hinged support is O, the central point of following ball hinged support be D and D point O order under, pneumatic support bar is E with turning the hinged ball pivot central point of shape bar, the last flex point that turns the shape bar is B, the following flex point that turns the shape bar is F, the P point place of center of gravity on the downward extended line of BF of big arm, when big arm during at initial position the BF extended line that makes progress be A with crossing the horizontal intersection point of O point, when big arm during at initial position the E point on short transverse, be fixed length AF apart from the O point, when big arm during at initial position the P point on short transverse, be fixed length AP apart from the O point, when big arm sees that it is fixed length AO that the P point departs from the O point in the horizontal direction in the front during at initial position, when big arm sees that this balanced structure is about OD line symmetric arrangement in the side during at initial position, the distance that BF line and E are ordered is FE.

2. the Optimization Design of a large-arm joint pneumatic balanced structure as claimed in claim 1 is characterized in that, step is as follows:

The first step: determine choosing of design variable and other parameter

If the central point of last ball hinged support is O, the central point of following ball hinged support be D and D point O order under, pneumatic support bar is E with turning the hinged ball pivot central point of shape bar, the last flex point that turns the shape bar is B, the following flex point that turns the shape bar is F, the P point place of center of gravity on the downward extended line of BF of big arm, when big arm during at initial position the BF extended line that makes progress be A with crossing the horizontal intersection point of O point, when big arm during at initial position the E point on short transverse, be fixed length AF apart from the O point, when big arm during at initial position the P point on short transverse, be fixed length AP apart from the O point, when big arm sees that it is fixed length AO that the P point departs from the O point in the horizontal direction in the front during at initial position, when big arm sees that this balanced structure is about OD line symmetric arrangement in the side during at initial position, the distance that BF line and E are ordered is FE;

The pneumatic thrust value of getting pneumatic support bar is design variable x ₁, unit: N;

Get between O, D two central points is design variable x apart from OD length ₂, unit: mm;

Getting FE length is design variable x ₃, unit: mm;

Do not exceeding under the big arm configuration size situation, getting AF is maximum;

Second step: require to determine x according to specific design ₁, x ₂, x ₃Span and carry out the initialization assignment;

The 3rd step: in big arm scope of activities, set up the outer weighing apparatus moment M that balances about large-arm joint pneumatic balanced structure _Wp, put gravitational moment M outward _Wz, forward swing trimming moment M _QpWith forward swing gravitational moment M _QzThe dynamic mathematical models of mechanics parameter, as follows:

The above-mentioned outer weighing apparatus moment M that balances _Wp, put gravitational moment M outward _Wz, forward swing trimming moment M _QpWith forward swing gravitational moment M _QzUnit be Nm;

$L_1=\sqrt{{\mathrm{AF}}^2+{(\mathrm{AO}-x_3)}^2}\&CenterDot;\sin {\mathrm{\&gamma;}}_1/1000$

$L_2=\sqrt{{\mathrm{AP}}^2+{\mathrm{AO}}^2}\&CenterDot;\sin ({\mathrm{\&theta;}}_1+{\mathrm{\&alpha;}}_1)/1000$

L ₃＝AF·sinγ ₂/1000

L ₄＝APsinα ₂/1000

M _wp＝x ₁·L ₁

M _wz＝m·g·L ₂

M _qp＝x ₁·L ₃

M _qz＝m·g·L ₄

Wherein: L ₁The balance arm of force when swinging for abduction, unit: m;

L ₂Weight arm when swinging for abduction, unit: m;

L ₃The balance arm of force during for swing, unit: m;

L ₄Weight arm during for swing, unit: m;

α ₁Be the outer pivot angle degree of big arm, independent variable, unit: degree;

γ ₁Being the ∠ OED in front view, is variable at the volley, can be according to α ₁Reach each parameter utilization geometry and the programming of trigonometric function knowledge and try to achieve unit: degree;

${\mathrm{\&theta;}}_1=\&angle;\mathrm{OPA}=\mathrm{arctg}\left(\frac{\mathrm{AO}}{\mathrm{AP}}\right),$ Unit: degree, definite value;

α ₂Be big arm swing angle, unit: degree, independent variable;

γ ₂Being the ∠ OED in lateral plan, is variable at the volley, can be according to α ₁Reach each parameter utilization geometry and the programming of trigonometric function knowledge and try to achieve unit: degree;

M is big arm weight, unit: kg;

G is an acceleration of gravity;

The 4th step: the requirement of interference does not mutually take place according to the structure of the structure space of big arm and working space, pneumatic support bar during with performance, motion, determine that the constraint function of design variable is as follows:

g ₁(x)＝x ₁-500≤0

g ₂(x)＝100-x ₁≤0

g ₃(x)＝x ₂-150≤0

g ₄(x)＝90-x ₂≤0

g ₅(x)＝x ₃-OA≤0

g ₆(x)＝60-x ₃≤0

The 5th step: the maximum of setting up the trimming moment that produces with big arm pneumatic support bar when forward and backward swing or the abduction swing and the difference absolute value of big arm gravitational moment can reach minimum object function:

f ₁(x)＝max(abs(ΔM _1i))

f ₂(x)＝max(abs(ΔM _2i))

min?f(x)＝max(f ₁(x)，f ₂(x))

Δ M wherein _1i=M _Wpi-M _Wzi, the trimming moment that pneumatic support bar produces when representing the swing of big arm abduction is put the numerical value of difference when diverse location of gravitational moment, i=1......n outward with big arm;

Δ M _2i=M _Qpi-M _Qzi, the numerical value of difference when diverse location of the trimming moment that pneumatic support bar produces when representing big arm swing and big arm forward swing gravitational moment, i=1......n;

f ₁The trimming moment that pneumatic support bar produced when (x) the big arm abduction of expression was swung and the maximum of the difference absolute value of big arm gravitational moment;

f ₂(x) maximum of the trimming moment that pneumatic support bar produces during the big arm swing of expression and the difference absolute value of big arm gravitational moment;

F (x) is f ₁(x) and f ₂(x) maximum in is an object function, and results of optimum design is to make f (x) reach minimum,, makes that the maximum in the difference absolute value of the big arm trimming moment that pneumatic support bar produces when swing or abduction swing and big arm gravitational moment reaches minimum that is;

The 6th step: according to the computer program of the dynamic mathematical models and the object function establishment optimal design of design variable, constraint function, big arm strength mathematic(al) parameter, and the input computer moves, and adopts constrained optimal design algorithm to each design variable x ₁, x ₂, x ₃Be optimized calculating, until the optimal value that reaches expectation;

The 7th step: output Optimal design and calculation result and motion simulation figure thereof.

3. the Optimization Design of large-arm joint pneumatic balanced structure as claimed in claim 2 is characterized in that:

The heavy m=10kg of described big arm;

The distance of described P point ball hinged support (1) central point O on distance on the short transverse is AP=330mm;

The distance of described ball pivot (5) central point E ball hinged support (1) central point O on distance on the short transverse is AF=310mm;

It is AO=98mm that described P point departs from the distance that O orders in the horizontal direction;

The scope of activities of described big arm is 0 °-90 ° of abduction swing, swing-90 °-90 °;

The pneumatic thrust value of described pneumatic support bar (4) is x ₁=399.9595N;

The described centre-to-centre spacing OD length that goes up ball hinged support (1) and following ball hinged support (2) is x ₂=91.8500mm;

Be x apart from FE length between described BF line and ball pivot (5) central point E ₃=60.0000mm;

Described object function is f (x)=8.4720Nm.

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