Background technology
Welding robot, which is not required nothing more than, can be used for the welding of straight line and arch welded joint, weld seam is larger or special welding procedure
It is required that under often use pendulum weldering.Pendulum weldering refers to that welding torch is periodically swung along bead direction with special angle and welded
Connect, to increase bead width, so as to improve a kind of welding method of weld strength and welding efficiency, it is in automatic welding equipment
In have been obtained for being widely applied.Weldering can will be put according to the shape of pendulum weldering arc manipulation and be divided into the weldering of sawtooth pendulum, sinusoidal pendulum, three angle swings weldering
And circular pendulum weldering.Three angle swings weldering refers to that torch tip does continuous triangular motion and constantly along welding side along welding direction
A kind of welding manner welded is swung so as to realize to feeding, it has a wide range of applications in welding procedure.
Chinese patent application 201310507312.7 discloses a kind of planning side of arc welding robot biplane swinging arc track
Method, its planing method based on Time Continuous determines the biplane swinging arc track of arc welding robot.First, rising for welding is obtained
The posture information of point, terminal and any two points in two swinging arc planes, then sets acceleration time scale ratio, maximum
Acceleration A max and maximal rate Vmax.Then, the functional relation of origin-to-destination direction position and time are obtained by integration,
According to SIN function formula, the position planning in swinging arc plane is determined;Pass through matrixing again, by the location point in swinging arc plane
The location point under robot basis coordinates system is converted into, so that control machine people carries out swinging arc motion.But the method requires welding gun
Direction of feed be necessary for tool coordinates system Z axis positive direction, reduce the flexibility that user uses;And it is only used for double flat
The straight line pendulum weldering in face, exists and greatly uses limitation.
Article《Arc welding robot puts the research of soldering method》A kind of implementation method of plane trigonometry pendulum weldering is proposed, but it is only
Linear pattern pendulum weldering is can apply to, there is significant limitation in the use of welding." the five dot pattern teachings mentioned behind
Method " will ask for middle interpolated point respectively according to a variety of situations, calculate excessively cumbersome.
The content of the invention
The goal of the invention of the present invention, is the defect for overcoming prior art to exist, it is proposed that a kind of welding robot welding
The plane trigonometry pendulum soldering method of arch welded joint, has expanded the use occasion that robot swings welding, has improved welding efficiency, improve weldering
Connect technique.
The angle swing of arch welded joint three weldering includes the weldering of plane circular arc triangle pendulum and the angle swing of space circular arc three weldering.Plane circular arc triangle is put
As shown in Figure 1, the both sides for referring to arch welded joint are flat sheet for weldering.
The present invention is to realize goal of the invention the technical scheme adopted is that a kind of welding robot welds the flat of arch welded joint
The angle swing soldering method of face three, its step is as follows:
1st, following parameter is determined:Weld starting point coordinate Pstart(xs,ys,zs), coordinate of ground point Ptarget(xt,yt,zt) (weldering
Connect terminal), auxiliary point coordinates Paux(xa,ya,za), auxiliary magnet is any point between welding beginning and end on arch welded joint;
The center of circle of arch welded joint is O0(x0,y0,z0), radius be r;Robot basis coordinates system initial point is O (0,0,0);Welding torch amplitude of oscillation H, weldering
Torch pendulum width L.
2nd, welding interpolated point P is calculated according to the amplitude of oscillation and pendulum are widei, i=1,2 ... n, wherein, odd number interpolated point is in arch welded joint
Outside, even number interpolated point is in the inner side of arch welded joint:
A, determine arch welded jointWelding direction;
By welding starting point, target point and auxiliary dot position information, position vector can be obtainedBy two
Position vector determines bead direction.
B, calculating weld seam in-plane cosine value
Plane is M where setting welding, nx,ny,nzFor weld seam in-plane cosine value.Any two vectorial multiplication crosses on M
Its normal vector can be obtained, by normal vector it is unitization after obtain
C, calculating weld seam central angle and unit interpolation angle
The corresponding central angle θ of circular arc weld seam is weld seam central angle, unit interpolation angle θ0(i.e. positioned at arch welded jointUpper two neighboring middle interpolated point P 'i-1And Pi' between corresponding central angle).By the center of circle and weld
Point, target point, auxiliary magnet obtain three position vectorsIf angSA is vectorWith to
AmountAngle, angAT is vectorWith vectorAngle, angST is vectorWith vectorFolder
Angle.AngSA, angAT, angST value can be obtained by the multiplication formula of vector, then it is big by angSA, angAT, angST three
Small relation can obtain the central angle θ corresponding to path of welding.
Unit interpolation angle θ is obtained by the welding torch pendulum width L, welding torch amplitude of oscillation H and the arc radius r that set0。
D, ask for weld seam welding interpolated point Pi
According to circular arc weld seam corresponding central angle θ and unit interpolation angle θ0, calculate torch oscillation in welding process
Number n.
Using the Rotation Algorithm of space coordinate, by welding starting point PstartAround passing through center of circle O0Unit normal vector Angular Interpolations
Angle αiObtain the middle interpolated point P on arch welded jointi' coordinate value.Shown in space coordinate Rotation Algorithm premultiplication matrix such as formula (1):
C is cos α in formulai, S is sin αi, (nx,ny,nz) be unit normal vector direction cosines value, (x0,y0,z0) it is circle
Heart O0Coordinate value.
Interpolated point P in the middle of theni' (x ', y ', z ') coordinate value can pass through matrix R premultiplication weld seam starting points PstartCoordinate is obtained,
As shown in formula (2):
[x′,y′,z′,1]T=R [xs,ys,zs,1]T (2)
It may know that by accompanying drawing 1, weld seam welding interpolated point is divided into two kinds of the inner side point and points outside of arch welded joint, sets herein
Proportionality coefficient is followed successively by l1、l2, proportionality coefficient l can determine that by arc radius r and amplitude of oscillation H1、l2Value, wherein l1=(r+H)/r, l2
=(r-H)/r.Then weld seam welding interpolated point is obtained by formula (3):
The present invention, using flexibility height, expands the use of arc welding robot suitable for the plane pendulum weldering of circular arc weld seam
Occasion.
This algorithm is based on motion kernel upper strata and planned, highly versatile calculates simple, and be easily achieved.And to
The use at family is not limited, and cannot be only used for arc welding robot, it can also be used to other welders that can be moved along a straight line.
The present invention is using two positions vectorThe method of multiplication cross, circular arc is determined according to multiplication cross result
The direction of rotation of weld seam.By three position vectorsAngle angSA, angAT, angST, root
The central angle corresponding to arch welded joint is determined according to the magnitude relationship between three.The present invention calculates interpolation angle using the thought divided equally
αi, utilization space coordinates rotating algorithm passes through weld seam starting point (Pstart) middle interpolated point P ' is obtained around rotary shaft rotary insertion supplementary angle,
Then welding interpolated point P is calculated according to amplitude of oscillation Hi.Rotary shaft is the unit normal vector axle of plane where arch welded joint, and the axle is logical
Cross the center of circle of arch welded joint.The present invention carries out interpolation planning on motion kernel upper strata, utilizes the welding of linear interpolation arch welded joint
Path, algorithm is simple and versatility is good;It cannot be only used for the angle swing of circular arc three weldering of arc welding robot, it can also be used to which other can enter
The welder of row linear motion.
Embodiment:The present embodiment is welding robot welding arch welded joint, and soldering method is put using plane trigonometry.
1st, following parameter is determined:Weld starting point coordinate Pstart(901.7880,182.9200,932.7880), target point are sat
Mark Ptarget(901.7880,210.9640,960.6240), auxiliary point coordinates Paux(918.1900,194.9720,
948.5460);The center of circle of arch welded joint is O0(898.4030,197.3336,946.3114), radius are 20.0523;Robot
Basis coordinates system initial point is O (0,0,0);Welding torch amplitude of oscillation H is that 8cm, welding torch pendulum width L are 3cm.
2nd, welding interpolated point P is calculated according to the amplitude of oscillation and pendulum are widei, i=1,2 ... n, wherein, odd number interpolated point is in arch welded joint
Outside, even number interpolated point is in the inner side of arch welded joint.
A, determine arch welded jointWelding direction
By welding starting point, target point and auxiliary dot position information, position vector can be obtained Determine that bead direction is counterclockwise by two positions vector.
B, calculating weld seam in-plane cosine value
Plane is M where setting welding, nx,ny,nzFor direction cosines value.Any two vectorial multiplication crosses on M can be obtained
Its normal vector, by normal vector it is unitization after obtain
C, calculating weld seam central angle and unit interpolation angle
The corresponding central angle θ of circular arc weld seam is weld seam central angle, unit interpolation angle θ0.By the center of circle and welding starting point,
Target point, auxiliary magnet obtain three position vectors
AngSA (1.393798), angAT (1.403967), angST (2.797766) value can be obtained by the multiplication formula of vector,
It is then 2.797766 as the central angle θ corresponding to angSA, angAT, angST three magnitude relationship can obtain path of welding.
Wide by 3, the welding torch amplitude of oscillation 8 is put by the welding torch set and arc radius 20.0523 obtains unit interpolation angle θ0For
0.149749。
D, ask for weld seam welding interpolated point Pi
Central angle θ and unit interpolation angle θ according to corresponding to path of welding0, calculate torch oscillation in welding process
Number n is 19.
Using the Rotation Algorithm of space coordinate, by welding starting point PstartAround passing through center of circle O0Unit normal vector Angular Interpolations
Angle αiObtain the middle interpolated point P on arch welded jointi' coordinate value.
It may know that by accompanying drawing 1, weld seam welding interpolated point is divided into two kinds of the inner side point and points outside of arch welded joint, sets herein
Proportionality coefficient is followed successively by l1、l2, proportionality coefficient l can determine that by arc radius r and amplitude of oscillation H1、l2Value, r and H value is substituted into public
Formula l1=(r+H)/r, l2In=(r-H)/r, l can be obtained1For 1.398957, l2For 0.601043.Then weld seam welding interpolated point is as follows
Shown in table: