CN103909521B - The method utilizing pallet diagonal identification code buttress joint of robot initial parameter - Google Patents

Abstract

The present invention relates to a kind of method utilizing pallet diagonal identification code buttress joint of robot initial parameter, including: step 1: obtaining the joint the first joint circular cylindrical coordinate parameter when primary importance, primary importance is positioned at cornerwise end points of the pallet of rectangle；Step 2: obtaining the joint second joint circular cylindrical coordinate parameter when the second position, the second position is positioned at another end points cornerwise of pallet；Step 3: according to the kinematic decoupling characteristic of robot palletizer, set up the mapping between the first joint circular cylindrical coordinate parameter and second joint circular cylindrical coordinate parameter and rectangular coordinate, thus obtain initial parameter；It is one or more that initial parameter includes in initial radial distance, initial orientation angle, elemental height and initial joint rotation angle.The present invention relies on the kinematic decoupling characteristic of robot palletizer self structure, can obtain sufficiently accurate initial parameter, can be widely used on robot palletizer job task, produces good practical significance, remarkable in economical benefits.

Description

The method utilizing pallet diagonal identification code buttress joint of robot initial parameter

Technical field

The present invention relates to robot palletizer field, particularly relate to one and utilize pallet diagonal identification robot palletizer to close The method of joint initial parameter.

Background technology

Robot palletizer is generally of the joint of multiple serial or parallel connection, it usually needs enter the initial parameter in a certain joint Row identification.Typical robot palletizer, it is typically made up of four joint series/parallel, is widely used in packed or case dress The automatic stacking operation of goods, reduces labor intensity, improves production efficiency.

In actual piling operation process, typical robot palletizer includes being closed by four separately-driven waists of servomotor Joint, drag articulation, flapping articulation and carpal joint.Wherein, drag articulation and the enlarger of flapping articulation composition parallel form, two Kinematic decoupling between joint, belongs to cylindrical robot.The angular signal of servomotor feedback motor, passes according to mechanism Dynamic relation can deduce corresponding joint rotation angle or handgrip position.

The subsidiary handgrip of carpal joint, is used for grasping goods and moves back and forth at a high speed, and acted on by goods inertia force.In order to keep away That exempts from that rigidity deficiency causes rocks, and robot palletizer generally uses hybrid connected structure.Use the robot palletizer structure of series-parallel connection not only Have the advantages that cascaded structure work space is big, and the feature that the rigidity that has parallel-connection structure concurrently is big, it is suitable for high speed piling and appoints Business.

The actual zero-bit in four joints of robot palletizer is typically by proximity switch corresponding to each joint or absolute encoder Zero-bit determine, often there is certain deviation with the layout design of robot palletizer.These deviations are for a certain machine For people it is one group and determines numerical value, it is common that one group of geometric parameter (i.e. initial parameter), these geometric parameters are robot palletizers The input parameter of inverse kinematic, is requisite.

The method measured often through reality in practice obtains these geometric parameters, but utilizes general measurement work The geometric parameter error that tool obtains is bigger, it is impossible to meet the required precision of inverse kinematic.It is therefore desirable to service precision is higher The complex instrument equipment such as laser interferometer carry out the measurement of bulk, to determine the initial ginseng of robot palletizer accurately Number.But, laser interferometer cost is high, and installation and debugging are difficult, is unfavorable for that actual field solves problem.

Summary of the invention

It is an object of the invention to provide a kind of low cost, be easily installed debugging utilize pallet diagonal identification code stack machine device The method of person joint's initial parameter.

For solving above-mentioned technical problem, as one aspect of the present invention, it is provided that one utilizes pallet diagonal identification The method of robot palletizer joint initial parameter, including:

Step 1: obtaining the joint the first joint circular cylindrical coordinate parameter when primary importance, primary importance is positioned at the torr of rectangle Cornerwise end points of dish；

Step 2: obtaining the joint second joint circular cylindrical coordinate parameter when the second position, the second position is positioned at the right of pallet Another end points of linea angulata；

Step 3: according to the kinematic decoupling characteristic of robot palletizer, sets up the first joint circular cylindrical coordinate parameter and second and closes Mapping between pitch cylinder coordinate parameters and rectangular coordinate, thus obtain initial parameter；

Wherein, during initial parameter includes initial radial distance, initial orientation angle, elemental height and initial joint rotation angle Individual or multiple.

Further, step 3 obtains initial radial distance according to following formula:

[R₀+(p+1)r₁]²+[R₀+(p+1)r₂]²-2[R₀+(p+1)r₁][R₀+(p+1)r₂]cos(θ₁-θ₂)=l²

Wherein, R₀For initial radial distance；P is joint motions amplification coefficient；r₁It is in the first joint circular cylindrical coordinate parameter Radial distance；r₂For the radial distance in second joint circular cylindrical coordinate parameter；θ₁It it is the orientation in the first joint circular cylindrical coordinate parameter Angle；θ₂For the azimuth in second joint circular cylindrical coordinate parameter；L is the distance between primary importance and the second position, i.e. diagonal angle The length of line,Wherein, a is the length of pallet；B is the width of pallet.

Further, step 3 obtains initial orientation angle according to following formula:

cos(θ₀+θ₁)[R₀+(p+1)r₁]-cos(θ₀+θ₂)[R₀+(p+1)r₂]=x₁-x₂

Wherein, θ₀Initial orientation angle；θ₁It it is the azimuth in the first joint circular cylindrical coordinate parameter；θ₂For second joint cylinder Azimuth in coordinate parameters；P is joint motions amplification coefficient；r₁It it is the radial distance in the first joint circular cylindrical coordinate parameter；r₂ For the radial distance in second joint circular cylindrical coordinate parameter；x₁For joint x coordinate under rectangular coordinate when primary importance；x₂For Joint is the x coordinate under rectangular coordinate when the second position；R₀For initial radial distance.

Further, step 3 obtains elemental height according to following formula:

V₀=pv₁+z₁Or V₀=pv₂+z₂

Wherein, V₀For elemental height；P is joint motions amplification coefficient；v₁It it is the height in the first joint circular cylindrical coordinate parameter Degree；v₂For the height in second joint circular cylindrical coordinate parameter；z₁For the joint z coordinate when primary importance is at rectangular coordinate；z₂For Joint is the z coordinate under rectangular coordinate when the second position.

Further, step 3 obtains initial joint rotation angle according to following formula:

Or

Wherein, A₀For initial joint rotation angle；θ₁It it is the azimuth in the first joint circular cylindrical coordinate parameter；θ₂For second joint Azimuth in circular cylindrical coordinate parameter；α₁It it is the joint rotation angle in the first joint circular cylindrical coordinate parameter；α₂Sit for second joint cylinder Joint rotation angle in mark parameter.

Further, robot palletizer includes waist joint, drag articulation, flapping articulation, wrist translation maintaining body and wrist Joint；Waist joint rotates to drive drag articulation, flapping articulation, wrist translation maintaining body and carpal joint to turn around vertical axis Dynamic；Wrist translation maintaining body is connected with drag articulation, flapping articulation and carpal joint respectively；Drag articulation in the vertical direction Motion and flapping articulation motion synthesis in the horizontal direction make carpal joint planar move.

Further, robot palletizer has multiple joints hybrid connected structure form, and the drag articulation of robot palletizer and Flapping articulation is mobile decoupling.

Further, robot palletizer includes the carpal joint for piling up on pallet by goods, and initial parameter is that wrist closes The initial parameter of joint；Primary importance and the second position are arranged on cornerwise two end points of pallet.

Further, discrimination method also includes step 4: changing diagonal or pallet, repetition step 1 is to step 3, to obtain Two groups or organize initial parameter more, many group initial parameters are weighted average after, obtain final initial parameter.

Compared with prior art, the discrimination method of the initial parameter in the present invention, rely on robot palletizer self structure Kinematic decoupling characteristic, the motion of the relative position (i.e. primary importance and the second position) of available two diagonal end points of pallet Implement, using the relative coordinate of the two position and relative distance as input parameter, thus initial parameter can be obtained, it is possible to It is widely used on robot palletizer job task, produces good practical significance, remarkable in economical benefits.

Accompanying drawing explanation

Fig. 1 diagrammatically illustrates series-parallel connection robot palletizer structure principle chart；

Fig. 2 diagrammatically illustrates the identification principle figure one of initial parameter；

Fig. 3 diagrammatically illustrates the identification principle figure two of initial parameter；And

Fig. 4 diagrammatically illustrates the identification principle figure three of initial parameter.

Detailed description of the invention

Below in conjunction with accompanying drawing, embodiments of the invention are described in detail, but the present invention can be defined by the claims Implement with the multitude of different ways covered.

Robot palletizer is generally of the joint of multiple serial or parallel connection, it usually needs enter the initial parameter in a certain joint Row identification.

The invention provides a kind of method utilizing pallet diagonal identification code buttress joint of robot initial parameter, including:

Step 1: obtaining the joint the first joint circular cylindrical coordinate parameter when primary importance, primary importance is positioned at the torr of rectangle Cornerwise end points of dish；

Step 2: obtaining the joint second joint circular cylindrical coordinate parameter when the second position, the second position is positioned at the right of pallet Another end points of linea angulata；So, primary importance distinguishes the diagonal end points of corresponding a certain known rectangular tray with the second position Place；

Step 3: according to the kinematic decoupling characteristic of robot palletizer, sets up the first joint circular cylindrical coordinate parameter and second and closes Mapping between pitch cylinder coordinate parameters and rectangular coordinate, thus obtain initial parameter；

Wherein, during initial parameter includes initial radial distance, initial orientation angle, elemental height and initial joint rotation angle Individual or multiple.

By obtain a certain joint the first joint circular cylindrical coordinate parameter when primary importance and when the second position the Two circular cylindrical coordinate parameters, and this first, second joint circular cylindrical coordinate parameter can be set up according to the kinematic decoupling characteristic of robot And the relation between this primary importance and rectangular coordinate of the second position, so, just can pass through these relations, obtain above-mentioned at the beginning of Beginning parameter.

Compared with prior art, the discrimination method of the initial parameter in the present invention, rely on robot palletizer self structure Kinematic decoupling characteristic, the motion of the relative position (i.e. primary importance and the second position) of available two diagonal end points of pallet Implement, can using the relative coordinate between the two position and relative distance as input parameter, thus obtain the most accurate Initial parameter, it is possible to be widely used on robot palletizer job task, produce good practical significance, economic benefit show Write.

Especially, this joint the first joint circular cylindrical coordinate Parameters Transformation coordinate at a right angle when primary importance can be obtained:

This joint second joint circular cylindrical coordinate Parameters Transformation coordinate at a right angle when the second position can be obtained:

In above-mentioned equation group (1) and equation group (2):

R₀For initial radial distance；θ₀For initial orientation angle；V₀For elemental height；A₀For initial joint rotation angle, aforementioned four Variable is initial parameter to be identified；

P is joint motions amplification coefficient；L is the length distance between primary importance and the second position, the most cornerwise length Degree,Wherein, a is the length of pallet；B is the width of pallet；

r₁It it is the radial distance in the first joint circular cylindrical coordinate parameter；r₂For the radial direction in second joint circular cylindrical coordinate parameter Distance；

θ₁It it is the azimuth in the first joint circular cylindrical coordinate parameter；θ₂For the azimuth in second joint circular cylindrical coordinate parameter；

v₁It it is the height in the first joint circular cylindrical coordinate parameter；v₂For the height in second joint circular cylindrical coordinate parameter；

α₁It it is the joint rotation angle in the first joint circular cylindrical coordinate parameter；α₂For the joint in second joint circular cylindrical coordinate parameter Corner；

x₁For joint x coordinate under rectangular coordinate when primary importance；x₂For joint when the second position under rectangular coordinate X coordinate；

y₁For joint y-coordinate under rectangular coordinate when primary importance；y₂For joint when the second position under rectangular coordinate Y-coordinate；

z₁For joint z coordinate under rectangular coordinate when primary importance；z₂For joint when the second position under rectangular coordinate Z coordinate.

The first formula in equation group (1) and the second formula are subtracted each other with the first formula in equation group (2) and the second formula respectively, can :

cos(θ₀+θ₁)[R₀+(p+1)r₁]-cos(θ₀+θ₂)[R₀+(p+1)r₂]=x₁-x₂Formula (1)

sin(θ₀+θ₁)[R₀+(p+1)r₁]-sin(θ₀+θ₂)[R₀+(p+1)r₂]=y₁-y₂Formula (2)

By formula (1) and formula (2) two ends summed square, and arrange can obtain through triangle formula:

[R₀+(p+1)r₁]²+[R₀+(p+1)r₂]²-2[R₀+(p+1)r₁][R₀+(p+1)r₂]cos(θ₁-θ₂)=l²

Formula (3)

Due in above formula, only R₀For unknown number, therefore, step 3 obtains initial radial distance according to formula (3).

Further, after obtaining initial radial distance, step 3 can also obtain initial orientation according to formula (1) or formula (2) Angle.

Preferably, step 3 can be able to respectively obtain according to the 3rd formula in equation group (1) or the 3rd formula in equation group (2) Elemental height:

V₀=pv₁+z₁Or V₀=pv₂+z₂Formula (4)

Preferably, step 3 can be able to respectively obtain according to the 4th formula in equation group (1) or the 4th formula in equation group (2) Initial joint rotation angle:

OrFormula (5)

Refer to Fig. 1, wherein, r is radial distance；θ is azimuth；V is height；α is joint rotation angle；X, Z are that right angle is sat Parameter；O is the intersection point of X-axis and Z axis.Preferably, robot palletizer includes waist joint 1, drag articulation 3, flapping articulation 2, wrist Translation maintaining body 4 and carpal joint 5；Waist joint rotates to drive drag articulation, flapping articulation, wrist translation to protect around vertical axis Hold mechanism and carpal joint rotates；Wrist translation maintaining body is connected with drag articulation, flapping articulation and carpal joint respectively；Vertical pass Motion and the flapping articulation motion synthesis in the horizontal direction of joint in the vertical direction make carpal joint at horizontal in-plane moving. Especially, robot palletizer has multiple joints hybrid connected structure form, and the drag articulation of robot palletizer and flapping articulation are Mobile decoupling.Preferably, waist joint 1 is arranged on base 6.

Fig. 2 is that robot palletizer is in reference to schematic diagram during zero-bit, and Fig. 3 is that robot palletizer is in primary importance P₁Time Schematic diagram, Fig. 4 is that robot palletizer is positioned at second position P₂Time schematic diagram.Wherein, l₀Refer to that robot palletizer is in zero-bit Time carpal joint (wrist center) with the distance of the central axis of waist joint 1 (waist seat).

Preferably, refer to Fig. 2 to Fig. 4, robot palletizer includes the carpal joint for piling up on pallet by goods, just Beginning parameter is carpal initial parameter；Primary importance P₁With second position P₂It is arranged on pallet.Primary importance P₁And second Put P₂It is cornerwise two end points on pallet.Preferably, cornerwise length is known.Especially, pallet level Rotate, and the height on distance ground is also known.Preferably, pallet is flatly placed.

Preferably, in FIG, if BC=DE=a ', AC=b ', CD=BE=d ', EF=e ', and meet d=pb ', e= Pa ' (p is the amplification coefficient of parallel-connection structure).This tittle above-mentioned is the geometric constant determined, can pass through Machine Design and processing Ensure.

Rely on above-mentioned specific physical dimension, it is possible to achieve the mobile decoupling of robot palletizer.When robot palletizer waist closes During the motor rotation saved, carpal joint rotates around axle of the plummet；When the motor rotation of robot palletizer drag articulation, carpal joint is along lead Hammer axis moves up and down, and carpal displacement is p times of displacement of drag articulation；When the motor of flapping articulation is transported When turning, carpal joint moves forward and backward along horizontal axis, and carpal displacement is p+1 times of displacement of flapping articulation； When carpal motor rotates, adjust goods at the angle of inclination of horizontal plane.

Especially, primary importance P on pallet₁With second position P₂Between relative distance be known, so, formula (1) In x₂-x₁=b, the y in formula (2)₁-y₂=a, wherein a is the length of pallet；B is the width of pallet.

Can set up its coordinate system XOY of robot palletizer, usually, this coordinate system may be provided on big ground level.Distinguish During knowledge, available controller moves each joint of robot palletizer and moves so that carpal joint respectively with primary importance P₁With Second position P₂Overlap.So, so that it may initial parameter when utilizing the length dimension identification robot palletizer of pallet to be in zero-bit.

Preferably, discrimination method also includes step 4: changing an other diagonal, repetition step 1 is to step 3, to obtain Two groups of initial parameters, after being weighted two groups of initial parameters of gained averagely, obtain final initial parameter.Such as, the present invention In discrimination method, can implement on two diagonal of the known pallet of another one, solve corresponding second group initial Parameter；Then these two groups of initial parameters are averaged, identification precision can be improved further.

Discrimination method in the present invention, not by each joint physical dimension and mismachining tolerance is affected and restriction, Ke Yiti Supply the suction parameter of the robot palletizer inverse kinematic of the kinematic decoupling of series-parallel connection.This discrimination method does not uses externally measured device Tool, and precision is the most outside influences, it is possible to it is greatly improved the reliability of geometric parameter identification.

The present invention can identification robot palletizer initial parameter when being in zero-bit, be provided without any externally measured sensing Device, only relies on the diagonal of pallet, can once pick out four initial parameters.

During real-time identification, owing to the cornerwise two-end-point of robot palletizer carpal joint and pallet overlaps, Ke Nengcun At small alignment error, cause identification parameter drift-out actual value out, can be by cornerwise at the known pallet of many groups 2 above-mentioned discrimination methods of upper use, it is thus achieved that organize geometric parameter more, ask for the meansigma methods of target identification parameter, thus improve identification Precision.

The foregoing is only the preferred embodiments of the present invention, be not limited to the present invention, for the skill of this area For art personnel, the present invention can have various modifications and variations.All within the spirit and principles in the present invention, that is made any repaiies Change, equivalent, improvement etc., should be included within the scope of the present invention.

Claims (9)

1. the method utilizing pallet diagonal identification code buttress joint of robot initial parameter, it is characterised in that including:

Step 1: obtaining the described joint the first joint circular cylindrical coordinate parameter when primary importance, described primary importance is positioned at rectangle Cornerwise end points of described pallet；

Step 2: obtain the described joint second joint circular cylindrical coordinate parameter when the second position, the described second position is positioned at described Another end points cornerwise of pallet；

Step 3: according to the kinematic decoupling characteristic of described robot palletizer, sets up described first joint circular cylindrical coordinate parameter and Mapping between two joint circular cylindrical coordinate parameters and rectangular coordinate, thus obtain described initial parameter；

Wherein, during described initial parameter includes initial radial distance, initial orientation angle, elemental height and initial joint rotation angle Individual or multiple；

In described step 3, according to below equation group (1) by the described joint the first joint circular cylindrical coordinate ginseng when primary importance Number conversion coordinate at a right angle:

$\left\{\begin{array}{c}cos({\mathrm{\θ}}_0+{\mathrm{\θ}}_1)\[R_0+(p+1)r_1\]=x_1\\ sin({\mathrm{\θ}}_0+{\mathrm{\θ}}_1)\[R_0+(p+1)r_1\]=y_1\\ V_0-{\mathrm{pv}}_1=z_1\\ {\mathrm{\α}}_1-A_0-{\mathrm{\θ}}_1=\frac{\mathrm{\π}}{2}\end{array}\right.---\left(1\right)$

Wherein, R₀For initial radial distance；θ₀For initial orientation angle；V₀For elemental height；A₀For initial joint rotation angle, p is joint Motion amplification coefficient, θ₁It is the azimuth in the first joint circular cylindrical coordinate parameter, r₁It it is the footpath in the first joint circular cylindrical coordinate parameter To distance, v₁It is the height in the first joint circular cylindrical coordinate parameter, α₁It is the joint rotation angle in the first joint circular cylindrical coordinate parameter, x₁For described the joint x coordinate under rectangular coordinate, y when primary importance₁For described joint when primary importance under rectangular coordinate Y-coordinate, z₁For described joint z coordinate under rectangular coordinate when primary importance；

According to below equation group (2) by the described joint second joint circular cylindrical coordinate Parameters Transformation seat at a right angle when the second position Mark:

$\left\{\begin{array}{c}cos({\mathrm{\θ}}_0+{\mathrm{\θ}}_2)\[R_0+(p+1)r_2\]=x_2\\ sin({\mathrm{\θ}}_0+{\mathrm{\θ}}_2)\[R_0+(p+1)r_2\]=y_2\\ V_0-{\mathrm{pv}}_2=z_2\\ {\mathrm{\α}}_2-A_0-{\mathrm{\θ}}_2=\frac{\mathrm{\π}}{2}\end{array}\right.---\left(2\right)$

Wherein, r₂For the radial distance in second joint circular cylindrical coordinate parameter, θ₂For the orientation in second joint circular cylindrical coordinate parameter Angle, v₂For the height in second joint circular cylindrical coordinate parameter, α₂For the joint rotation angle in second joint circular cylindrical coordinate parameter, x₂For Described joint is the x coordinate under rectangular coordinate, y when the second position₂Sit for described joint y under rectangular coordinate when the second position Mark, z₂For described joint z coordinate under rectangular coordinate when the second position.

Method the most according to claim 1, it is characterised in that described step 3 according to following formula obtain described initial radial away from From:

[R₀+(p+1)r₁]²+[R₀+(p+1)r₂]²-2[R₀+(p+1)r₁][R₀+(p+1)r₂]cos(θ₁-θ₂)=l²

Wherein, l is the distance between described primary importance and the described second position, the most described cornerwise length,Wherein, a is the length of described pallet；B is the width of described pallet.

Method the most according to claim 2, it is characterised in that described step 3 obtains described initial orientation angle according to following formula:

cos(θ₀+θ₁)[R₀+(p+1)r₁]-cos(θ₀+θ₂)[R₀+(p+1)r₂]=x₁-x₂。

Method the most according to claim 1, it is characterised in that described step 3 obtains described elemental height according to following formula:

V₀=pv₁+z₁

Or

V₀=pv₂+z₂。

Method the most according to claim 1, it is characterised in that described step 3 obtains described initial joint according to following formula and turns Angle:

${\mathrm{\α}}_1-{\mathrm{\θ}}_1-\frac{\mathrm{\π}}{2}=A_0$

Or

${\mathrm{\α}}_2-{\mathrm{\θ}}_2-\frac{\mathrm{\π}}{2}=A_0.$

Method the most according to claim 1, it is characterised in that described robot palletizer includes waist joint, drag articulation, water Flat joint, wrist translation maintaining body and carpal joint；

Described waist joint rotates to drive described drag articulation, flapping articulation, wrist translation maintaining body and wrist around vertical axis Articulation；

Described wrist translation maintaining body is connected with described drag articulation, flapping articulation and carpal joint respectively；

Motion and the described flapping articulation motion synthesis in the horizontal direction of described drag articulation in the vertical direction make institute State carpal joint planar to move.

Method the most according to claim 1, it is characterised in that described robot palletizer has multiple joints hybrid connected structure shape Formula, and the drag articulation of described robot palletizer and flapping articulation be mobile decoupling.

Method the most according to claim 7, it is characterised in that described robot palletizer includes for goods is piled up torr Carpal joint on dish, described initial parameter is described carpal initial parameter；

Described primary importance and the described second position are arranged on cornerwise two end points of described pallet.

Method the most according to claim 1, it is characterised in that described discrimination method also includes step 4:

Change diagonal or pallet, repeating said steps 1 to step 3, to obtain organizing described initial parameter more, to organize more described at the beginning of After beginning parameter is weighted averagely, obtain final initial parameter.