CN104985586B - A kind of allosteric type robot for space and paths planning method - Google Patents

Abstract

The invention discloses a kind of allosteric type robot for space and paths planning method, any two the 6th armed levers in allosteric type robot for space are captured mutually, form closed-loop structure；Unlock the passive cylinder hinge in the armed lever of configuration to be changed；Closed-loop structure is equivalent to into open cycle system：Cut with scissors as boundary with the passive cylinder for unlocking, whole closed-loop structure is divided into into two sections, one section of total number of degrees of freedom, is more, and another section of total number of degrees of freedom, is less, two armed levers being connected by passive cylinder hinge in two sections are constrained by passive cylinder hinge；It is determined that the more end armed lever of total number of degrees of freedom, relative to the characteristics of motion of robot for space platform；The end armed lever is two armed levers being connected with passive cylinder hinge；According to the more end armed lever of the total number of degrees of freedom, in step (4), relative to the characteristics of motion of robot for space platform, each joint angle time series is solved.Present invention achieves the autonomous allosteric type of mechanical arm, improves the in-orbit operational capacity of mechanical arm.

Description

A kind of allosteric type robot for space and paths planning method

Technical field

The present invention relates to a kind of allosteric type robot for space and paths planning method, more particularly to a kind of to be based on unusual tolerance The path planning algorithm for avoiding robot unusual and autonomous allosteric type Robot Design, belong to robot for space field.

Background technology

Using robot for space to carrying out reclaiming, safeguarding, recycle beyond service phase or the spacecraft that breaks down, can be with Save substantial amounts of human resourcess and fund.But as robot for space capture target is a complicated spatial operation, generally The structure parameters (armed lever length, joint rotor shaft direction etc.) of mechanical arm are for a certain specific task design.In order that mechanical Arm has higher versatility, reduces the cost of whole space mission, expects that mechanical arm has allosteric type, becomes the spy of armed lever length Point.For this purpose, a kind of " passive cylinder hinge " mechanism is designed.Passive cylinder has been hinged two rigid armed levers, and there is passive lock inside Dead device.In operating at ordinary times, cylinder hinge is internal locked, fixes the relative translational movement between two rigid bodies and rotation.In space machine During device people's allosteric type, certain point on mechanical arm tail end actuator capture robot for space platform, or two mechanical arms Capture forms closed-loop structure to end effectors mutually, then discharges the locking mechanism inside passive cylinder hinge, by remaining pass Apply torque on section, change the relative translational movement between two rigid bodies and rotation, realize the autonomous allosteric type process of mechanical arm.

Passive cylinder cuts with scissors the addition of this new hinges, brings a difficult problem to system motion planning --- and freedom of movement increases Greatly, and need plan hinge inner motion.Existing research is calculated only for the small numbers of allosteric type mechanical arm system of hinge The method suitability cannot also meet the demand of in-orbit application.Further, since robot for space degree of freedom is more, configuration is easily trapped into very It is different, need design path planning algorithm while robot for space allosteric type is realized, it is to avoid configuration singularity, at present both at home and abroad also There is no a kind of paths planning method of the allosteric type mechanical arm system for being suitable for multiple degrees of freedom number.

The content of the invention

The technical problem to be solved in the present invention is：For the deficiencies in the prior art, there is provided a kind of allosteric type space machine People and paths planning method, realize the autonomous allosteric type of mechanical arm, improve the in-orbit operational capacity of mechanical arm.

The method of the present invention is achieved through the following technical solutions.

A kind of autonomous allosteric type robot for space includes：First rigid body, the second rigid body, passive cylinder hinge, robot for space Platform, multiple robotic arms；Wherein each mechanical arm again include the first armed lever, the second armed lever, the 3rd armed lever, the 4th armed lever, the 5th Armed lever and the 6th armed lever；Second armed lever includes armed lever A and armed lever B again, and the 3rd armed lever includes armed lever C and armed lever D again；

First rigid body, the second rigid body are connected by passive cylinder hinge；

One end of first armed lever is connected with robot for space platform by post hinge, the other end of the first armed lever is cut with scissors by post and One end of armed lever A is connected；

The other end of armed lever A is connected with one end of armed lever B by passive cylinder hinge；The other end of armed lever B by post hinge with One end of armed lever C is connected；

The other end of armed lever C is connected with one end of armed lever D by passive cylinder hinge；The other end of armed lever D by post hinge with One end of 4th armed lever is connected；

The other end of the 4th armed lever is connected with one end of the 5th armed lever by post hinge；The other end of the 5th armed lever is cut with scissors by post It is connected with one end of the 6th armed lever.

A kind of paths planning method for allosteric type robot for space, including step is as follows：

(1) any two the 6th armed levers in allosteric type robot for space are captured mutually, form closed-loop structure；

(2) the passive cylinder hinge in the armed lever of configuration to be changed is unlocked, two rigid bodies that the passive cylinder is hinged are enable Enough there is relative translational movement and rotation；

(3) closed-loop structure in step (1) is equivalent to into open cycle system：Cut with scissors with the passive cylinder of unblock in step (2) and be Whole closed-loop structure is divided into two sections by boundary, and one section of total number of degrees of freedom, is more, and another section of total number of degrees of freedom, is less, in two sections Two armed levers being connected by passive cylinder hinge are constrained by passive cylinder hinge；

(4) according to allosteric type demand, it is determined that the more end armed lever of total number of degrees of freedom, relative to robot for space platform The characteristics of motion；The end armed lever is two armed levers being connected with passive cylinder hinge；

(5) according to the end armed lever that the total number of degrees of freedom, in step (4) is more, relative to the motion of robot for space platform Rule, solves each joint angle time series.

The more end armed lever of total number of degrees of freedom, is determined in step (4), relative to the characteristics of motion of robot for space platform Concrete mode it is as follows：It is determined that the end armed lever of the less mechanical arm of total number of degrees of freedom, is kept not relative to robot for space platform It is dynamic, the end armed lever of the more mechanical arm of total number of degrees of freedom, is then calculated, relative to the less mechanical arm of total number of degrees of freedom, The characteristics of motion of end armed lever, most the end armed lever of the more mechanical arm of total number of degrees of freedom, is less relative to total number of degrees of freedom, at last Mechanical arm end armed lever the characteristics of motion, the end arm of the more mechanical arm of total number of degrees of freedom, is converted into by coordinate transform Position R of the bar relative to robot for space platform_tipWith attitude Ω_tipThe characteristics of motion.

Each joint angle seasonal effect in time series specific implementation is solved in step (5) as follows：

(5.1) the end armed lever of total more mechanical arm of number of degrees of freedom, and other each passes in this section in establishment step (4) Kinematic relation between section angle：

Wherein, q represents the matrix of each joint angle composition in the more mechanical arm of total number of degrees of freedom,Represent each joint Angular velocity；J (q) represents the Jacobian matrix of q；

(5.2) determine unusual metric m of the more mechanical arm of total number of degrees of freedom,：

(5.3) unusual metric m derivation is obtained

Wherein, J⁺Q () represents the generalized inverse of Jacobian matrix J (q)；K represents vector undetermined；I represents unit matrix, exponent number The number of degrees of freedom, of the mechanical arm more with total number of degrees of freedom,；

(5.4) it is to ensure that m has the trend of increase all the time, that is, ensuresThen it is obtainedWhen, ensure that

(5.5) k for being obtained according to step (5.4) and the kinematic relation of step (5.1), solve each joint angle speed Degree：

(5.6) each joint angular velocity that step (5.5) is obtained is integrated, obtains each joint angle time series.

The present invention having the beneficial effect that compared with prior art：

1. a kind of robot for space for being capable of autonomous allosteric type of the present invention, is designed based on passive cylinder hinge, increases space Robot movable degree of freedom so as to possess the function of allosteric type, improves the ability of the in-orbit operation of robot for space.

2. the paths planning method of the autonomous allosteric type of a kind of robot for space of the present invention, according to robot for space allosteric type The characteristics of stage, using the characteristic of degree of freedom in system redundancy, configuration singularity index is defined, design makes the road that index persistently increases Footpath planning algorithm, can avoid being absorbed in unusual in robot restructuring procedure.

3. a kind of paths planning method of the autonomous allosteric type of robot for space of the present invention, with universality, can be carried out Promote, i.e., the method is applicable not only to allosteric type robot for space, and is applied to ordinary robot and general linear multi degrees of freedom fortune The planning of dynamic system.

Description of the drawings

Fig. 1 is mechanical arm composition schematic diagram of the present invention；

Fig. 2 is the passive cylinder hinge schematic diagram of the present invention；

Fig. 3 is allosteric type robot for space structural representation of the present invention；

Fig. 4 is closed loop system schematic diagram when armed lever length of the present invention changes；

Fig. 5 is open cycle system schematic diagram equivalent when armed lever length of the present invention changes

Fig. 6 is the configuration schematic diagram of system after armed lever of the present invention is stretched；

Fig. 7 is the relative rotation angular velocity of each cradle head of mechanical arm of the present invention；

Fig. 8 is that armed lever A10 of the present invention and armed lever B11 is relatively rotated and translated schematic diagram；

Fig. 9 is unusual tolerance result schematic diagram of the invention.

Specific embodiment

Below in conjunction with the accompanying drawings the structure composition and operation principle of the present invention are further explained.

As shown in Figure 1, 2, 3, a kind of autonomous allosteric type robot for space includes：First rigid body 1, the second rigid body 2, passive circle Post hinge 3, robot for space platform 4, multiple robotic arms (adopt 3 mechanical arms, as shown in Fig. 2 mechanical arm 5, machine in the present embodiment Tool arm 6, mechanical arm is 7)；Wherein each mechanical arm again include the first armed lever 8, the second armed lever 9, the 3rd armed lever 12, the 4th armed lever 15, 5th armed lever 16 and the 6th armed lever 17；Second armed lever 9 includes armed lever A10 and armed lever B11 again, and the 3rd armed lever 12 includes armed lever again C13 and armed lever D14；

First rigid body 1, the second rigid body 2 are cylinder by 3 connected first rigid body 1 of passive cylinder hinge and the second rigid body 2.

One end of first armed lever 8 is connected with robot for space platform 4 by post hinge, the other end of the first armed lever 8 passes through post Hinge is connected with one end of armed lever A10；

The other end of armed lever A10 is connected with one end of armed lever B11 by passive cylinder hinge 3；The other end of armed lever B11 passes through Post hinge is connected with one end of armed lever C13；

The other end of armed lever C13 is connected with one end of armed lever D14 by passive cylinder hinge 3；The other end of armed lever D14 passes through Post hinge is connected with one end of the 4th armed lever 15；

The other end of the 4th armed lever 15 is connected with one end of the 5th armed lever 16 by post hinge；The other end of the 5th armed lever 16 leads to Cross post hinge to be connected with one end of the 6th armed lever 17.

Closed-loop structure can be formed by the mutually capture of respective 6th armed lever 17 between multiple mechanical arms.6th armed lever 17 End carry actuator.

Passive cylinder hinge (3) is passive locking structure, internal not comprising the actuator for actively applying controling power and torque, Two kinds of shape bodies are only existed, passive locked and unblock；When the hinge is locked, two rigid bodies of its connection are not allowed to occur relatively flat Dynamic and rotation；Conversely, can relative motion, so as to change the length and relative rotation of the armed lever of the two rigid bodies composition.At ordinary times In operation, passive cylinder hinge is locked, and mechanical arm can complete mutually capture formation between the capture to target and mechanical arm and close Ring structure etc. is operated.When needing to change mechanical arm configuration, the end effectors (end mechanical arm) of two mechanical arms are caught mutually Obtain, form closed-loop structure；Unlock some passive cylinder hinge, it is allowed to which two rigid bodies of its connection occur relative translational movement and rotation, By applying control moment on remaining joint, change mechanical arm configuration (including corner between armed lever length and armed lever).

A kind of paths planning method of the allosteric type robot for space for described in claim 1, including step is as follows：

(1) any two the 6th armed levers in allosteric type robot for space are captured mutually, form closed-loop structure；

(2) the passive cylinder hinge in the armed lever of configuration to be changed is unlocked, two rigid bodies that the passive cylinder is hinged are enable Enough there is relative translational movement and rotation；Passive cylinder hinge 3 between such as armed lever A10 and armed lever B11 in Fig. 4 is quilt to be unlocked Dynamic cylinder hinge, the mechanical arm of armed lever A10 and armed lever B11 compositions are the mechanical arms for needing to change configuration；

(3) closed-loop structure in step (1) is equivalent to into open cycle system：Cut with scissors with the passive cylinder of unblock in step (2) and be Whole closed-loop structure is divided into two sections by boundary, and one section of total number of degrees of freedom, is more, and another section of total number of degrees of freedom, is less, in two sections Two armed levers being connected by passive cylinder hinge are constrained by passive cylinder hinge；

As shown in figure 4, the 6th mutually capture of armed lever 17 of two mechanical arms 18 and 19 forms the closed loop system (portion in dotted line It is divided into mechanical arm 18 and 19), open cycle system is carried out as boundary with passive cylinder hinge 3 then equivalent, it can be clearly seen that armed lever A11 institutes Side the total number of degrees of freedom, of mechanical arm more (include armed lever of the mechanical arm 18 in addition to armed lever A10 and mechanical arm 19)；, such as Shown in Fig. 5, it is equivalent open cycle system schematic diagram, Fig. 6 is that mechanical arm deforms schematic diagram, and armed lever A10 and armed lever B11 is simultaneously pulled open.

(4) (armed lever is for example stretched to certain length, or change the armed lever at passive cylinder hinge two ends according to allosteric type demand The demands such as relative rotation), it is determined that the more end armed lever of total number of degrees of freedom, relative to the characteristics of motion of robot for space platform； The end armed lever is two armed levers being connected with passive cylinder hinge；

It is determined that the more end armed lever of total number of degrees of freedom, relative to the concrete mode of the characteristics of motion of robot for space platform It is as follows：It is determined that the end armed lever of the less mechanical arm of total number of degrees of freedom, is remained stationary as relative to robot for space platform, Ran Houji The end armed lever of the more mechanical arm of total number of degrees of freedom, is calculated, relative to the end armed lever of total number of degrees of freedom, less mechanical arm The characteristics of motion (can be solved by methods such as the planning of quintic algebra curve, be known to the skilled person), most total at last The end armed lever of the more mechanical arm of number of degrees of freedom, is advised relative to the motion of the end armed lever of the less mechanical arm of total number of degrees of freedom, Rule, is converted into the position of the end armed lever relative to robot for space platform of the more mechanical arm of total number of degrees of freedom, by coordinate transform Put R_tipWith attitude Ω_tipThe characteristics of motion.

(5) according to the end armed lever that the total number of degrees of freedom, in step (4) is more, relative to the motion of robot for space platform Rule, solves each joint angle time series.

Each joint angle seasonal effect in time series specific implementation is solved in step (5) as follows：

(5.1) the end armed lever of total more mechanical arm of number of degrees of freedom, and other each passes in this section in establishment step (4) Kinematic relation between section angle：Other joint angles in such as armed lever B11 in Fig. 5 be located with which a section, the circle in Fig. 6 Represent joint；

Wherein, q represents the matrix of each joint angle composition in the more mechanical arm of total number of degrees of freedom,Represent each joint Angular velocity；J (q) represents the Jacobian matrix of q；

(5.2) determine unusual metric m of the more mechanical arm of total number of degrees of freedom,：

The joint angle characteristics of motion is designed in trajectory planning algorithm, the change of desired armed lever length and corner is realized, together When ensure it is unusual tolerance increase, make mechanical arm away from unusual.As can be seen that m >=0 from above formula；During and if only if m=0, system Be configured as singular configuration.

(5.3) unusual metric m derivation is obtained

Wherein, J⁺Q () represents the generalized inverse of Jacobian matrix J (q)；K represents vector undetermined；I represents unit matrix, exponent number The number of degrees of freedom, of the mechanical arm more with total number of degrees of freedom,；(I-J⁺(q) J (q)) k for mechanical arm zero motion, the part will not Affect position and the attitude of mechanical arm end；

(5.4) it is to ensure that m has the trend of increase all the time, that is, ensuresThen it is obtainedWhen, ensure that

(5.5) k for being obtained according to step (5.4) and the kinematic relation of step (5.1), solve each joint angle speed Degree：

(5.6) each joint angular velocity that step (5.5) is obtained is integrated, obtains each joint angle time series.

According to the result of calculation of step (5.5), the rotational angular velocity that can obtain each armed lever is shown in Fig. 7.Fig. 8 is armed lever Motions of the B11 with respect to armed lever A10, Fig. 9 are the response of unusual tolerance m, it is seen that unusual tolerance increases all the time, it is to avoid configuration singularity

The scope of the present invention is not only limited to the present embodiment, and the present embodiment is used to explaining the present invention, it is all with it is of the invention Change or modification under the conditions of same principle and design is within protection domain disclosed by the invention.

Claims (7)

1. a kind of autonomous allosteric type robot for space, it is characterised in that include：First rigid body (1), the second rigid body (2), passive circle Post hinge (3), robot for space platform (4), multiple mechanical arms；Wherein each mechanical arm includes the first armed lever (8), the second armed lever again (9), the 3rd armed lever (12), the 4th armed lever (15), the 5th armed lever (16) and the 6th armed lever (17)；Second armed lever (9) includes arm again Bar A (10) and armed lever B (11), the 3rd armed lever (12) include armed lever C (13) and armed lever D (14) again；

One end of first armed lever (8) is connected with robot for space platform (4) by post hinge, the other end of the first armed lever (8) passes through Post hinge is connected with one end of armed lever A (10)；

The other end of the 4th armed lever (15) is connected with one end of the 5th armed lever (16) by post hinge；The other end of the 5th armed lever (16) It is connected with one end of the 6th armed lever (17) by post hinge；

Armed lever A (10) and armed lever C (13) is the first rigid body (1), and armed lever B (11) and armed lever D (14) is the second rigid body (2), first Rigid body (1), the second rigid body (2) are connected by passive cylinder hinge (3), specially：

The other end of armed lever A (10) is connected with one end of armed lever B (11) by passive cylinder hinge (3)；The other end of armed lever B (11) It is connected with one end of armed lever C (13) by post hinge；

The other end of armed lever C (13) is connected with one end of armed lever D (14) by passive cylinder hinge (3)；The other end of armed lever D (14) It is connected with one end of the 4th armed lever (15) by post hinge；

Passive cylinder hinge (3) is passive locking structure, internal not comprising the actuator for actively applying controling power and torque, Two kinds of shape bodies are only existed, passive locked and unblock；When the hinge is locked, two rigid bodies of its connection are not allowed to occur relatively flat Dynamic and rotation；Conversely, can relative motion, so as to change the length and relative rotation of the armed lever of the two rigid bodies composition.

2. a kind of autonomous allosteric type robot for space according to claim 1, it is characterised in that：First rigid body (1) Cylinder is with the second rigid body (2).

3. a kind of autonomous allosteric type robot for space according to claim 1, it is characterised in that：The plurality of mechanical arm it Between closed-loop structure can be formed by the mutually capture of respective 6th armed lever (17).

4. a kind of autonomous allosteric type robot for space according to claim 3, it is characterised in that：6th armed lever (17) End carry actuator.

5. a kind of paths planning method of the autonomous allosteric type robot for space for described in claim 1, it is characterised in that step It is rapid as follows：

(1) any two the 6th armed levers in allosteric type robot for space are captured mutually, form closed-loop structure；

(2) the passive cylinder hinge in the armed lever of configuration to be changed is unlocked, two rigid bodies that the passive cylinder is hinged is sent out Raw relative translational movement and rotation；

(3) closed-loop structure in step (1) is equivalent to into open cycle system：With in step (2), the passive cylinder of unblock is cut with scissors as boundary, Whole closed-loop structure is divided into into two sections, one section of total number of degrees of freedom, is more, another section of total number of degrees of freedom, is less, in two sections, passes through quilt Two armed levers that dynamic cylinder hinge is connected are constrained by passive cylinder hinge；

(4) according to allosteric type demand, it is determined that the more end armed lever of total number of degrees of freedom, relative to the motion of robot for space platform Rule；The end armed lever is two armed levers being connected with passive cylinder hinge；

(5) according to the end armed lever that the total number of degrees of freedom, in step (4) is more, the motion relative to robot for space platform is advised Rule, solves each joint angle time series.

6. a kind of paths planning method according to claim 5, it is characterised in that：Determine in the step (4) total free The more end armed lever of the number of degrees, it is as follows relative to the concrete mode of the characteristics of motion of robot for space platform：It is determined that total degree of freedom The end armed lever of the less mechanical arm of number is remained stationary as relative to robot for space platform, then calculates total number of degrees of freedom, more Mechanical arm end armed lever, it is relative to the characteristics of motion of the end armed lever of the less mechanical arm of total number of degrees of freedom, most total at last The end armed lever of the more mechanical arm of number of degrees of freedom, is advised relative to the motion of the end armed lever of the less mechanical arm of total number of degrees of freedom, Rule, is converted into the position of the end armed lever relative to robot for space platform of the more mechanical arm of total number of degrees of freedom, by coordinate transform Put R_tipWith attitude Ω_tipThe characteristics of motion.

7. a kind of paths planning method according to claim 5, it is characterised in that：Each pass is solved in the step (5) Section angle seasonal effect in time series specific implementation is as follows：

(5.1) the end armed lever of total more mechanical arm of number of degrees of freedom, and other each joint angles in this section in establishment step (4) Between kinematic relation：

$\left[\begin{array}{c}{\stackrel{\·}{R}}_{tip}\\ {\stackrel{\·}{\mathrm{\Ω}}}_{tip}\end{array}\right]=J\left(q\right)\stackrel{\·}{q}$

Wherein,The speed of the end armed lever relative to robot for space platform of the more mechanical arm of total number of degrees of freedom, is represented, The attitude angular velocity of the end armed lever relative to robot for space platform of the more mechanical arm of total number of degrees of freedom, is represented, q represents total The matrix of each joint angle composition in the more mechanical arm of number of degrees of freedom,Represent each joint angular velocity；J (q) represents that q's is refined Gram compare matrix；

(5.2) determine unusual metric m of the more mechanical arm of total number of degrees of freedom,：

$m=\sqrt{\det \left(J\right(q)J^T\left(q\right))}$

(5.3) unusual metric m derivation is obtained

$\stackrel{\·}{m}={\left(\frac{\∂m}{\∂q}\right)}^T{J}^{+}\left(q\right)\left[\begin{array}{c}{\stackrel{\·}{R}}_{tip}\\ {\stackrel{\·}{\mathrm{\Ω}}}_{tip}\end{array}\right]+{\left(\frac{\∂m}{\∂q}\right)}^T(I-J^{+}(q\left)J\right(q\left)\right)k$

Wherein, J⁺Q () represents the generalized inverse of Jacobian matrix J (q)；K represents vector undetermined；I represents unit matrix, exponent number with it is total The number of degrees of freedom, of the more mechanical arm of number of degrees of freedom, is identical；

(5.4) it is to ensure that m has the trend of increase all the time, that is, ensuresThen it is obtainedWhen, ensure that

(5.5) k for being obtained according to step (5.4) and the kinematic relation of step (5.1), solve each joint angular velocity：

$\stackrel{\·}{q}=J^{+}\left(q\right)\left[\begin{array}{c}{\stackrel{\·}{R}}_{tip}\\ {\stackrel{\·}{\mathrm{\Ω}}}_{tip}\end{array}\right]+(I-J^{+}(q\left)J\right(q\left)\right)k$

$\stackrel{\·}{q}=J^{+}\left(q\right)\left[\begin{array}{c}{\stackrel{\·}{R}}_{tip}\\ {\stackrel{\·}{\mathrm{\Ω}}}_{tip}\end{array}\right]+(I-J^{+}(q\left)J\right(q\left)\right)\left(\frac{\∂m}{\∂q}\right)k_1,k_1>0;$

(5.6) each joint angular velocity that step (5.5) is obtained is integrated, obtains each joint angle time series.