CN110450171B - Welding robot and swing track planning method thereof - Google Patents
Welding robot and swing track planning method thereof Download PDFInfo
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- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
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- B—PERFORMING OPERATIONS; TRANSPORTING
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Abstract
The application discloses a welding robot and a planning method of a swing track thereof, wherein the planning method comprises the following steps: determining first position coordinates and first attitude coordinates of a plurality of first track points on a welding seam under a workpiece coordinate system; determining position coordinates of second track points corresponding to the first track points under a swinging coordinate system, wherein the second track points corresponding to the first track points form a V-shaped offset track on the YOZ plane under the swinging coordinate system; converting the position coordinates of the second track point under the swinging coordinate system into second position coordinates under the workpiece coordinate system; superposing the first position coordinates of the first track points and the second position coordinates of the corresponding second track points to obtain the position coordinates of the interpolation points corresponding to the first track points in the workpiece coordinate system and obtain the position coordinates of the interpolation points corresponding to the first track points in the workpiece coordinate system; and determining the planned swing track according to the interpolation points. The swing track planning method is simple in calculation.
Description
Technical Field
The application relates to the technical field of welding robots, in particular to a welding robot and a planning method of a swing track of the welding robot.
Background
Swing welding (abbreviated as swing welding) of a welding robot is a welding mode in which a welding gun swings longitudinally at a certain rule while moving along a weld joint direction. The welding method improves the welding strength and the welding efficiency, is widely applied to the automatic welding technology, and has practical engineering significance.
The inventor of the application finds that the existing planning method of the swing track of the welding robot is complex in calculation, and the welding robot can hardly reach the expected speed and the expected period in the swing welding process.
Disclosure of Invention
The technical problem mainly solved by the application is to provide a welding robot and a method for planning a swing track of the welding robot, and the calculation method can be simplified.
In order to solve the technical problem, the application adopts a technical scheme that: provided is a method for planning a swing path of a welding robot, the method comprising: determining first position coordinates and first attitude coordinates of a plurality of first track points on a welding seam under a workpiece coordinate system; determining the position coordinates of second track points corresponding to the first track points under a swinging coordinate system, wherein the second track points corresponding to the first track points have offset increment relative to the welding line, the second track points corresponding to the first track points form a V-shaped offset track on a YOZ plane under the swinging coordinate system, the vertex of the V-shaped offset track is overlapped with the origin of the swinging coordinate system, and the opening faces to a Z-axis positive half shaft of the swinging coordinate system; converting the position coordinates of the second track points under the swinging coordinate system into second position coordinates under the workpiece coordinate system; superposing the first position coordinates of the first track points and the corresponding second position coordinates of the second track points to obtain position coordinates of interpolation points corresponding to the first track points in the workpiece coordinate system, wherein the attitude coordinates of the interpolation points are the first attitude coordinates; determining a planned swing track according to the position coordinates and the posture coordinates of the interpolation points; the system comprises a swinging coordinate system, a welding gun head, a welding gun and a welding gun, wherein the swinging coordinate system is a tool coordinate system, the origin of the swinging coordinate system is an endpoint of the welding gun, the X-axis direction is the advancing direction of the welding gun, the Y-axis direction is the swinging direction of the welding gun, and the Z; or, the swing coordinate system is a tool path coordinate system, the origin of the swing coordinate system is the end point of the welding gun, the X-axis direction is the tangential direction of the welding seam, the Y-axis direction is determined by the cross multiplication of the X-axis direction of the tool path coordinate system and the Z-axis direction of the tool coordinate system, and the Z-axis direction is determined by the cross multiplication of the X-axis direction and the Y-axis direction of the tool path coordinate system.
In order to solve the above technical problem, another technical solution adopted by the present application is: there is provided a welding robot comprising a processor, a memory and a communication circuit, the processor being coupled to the memory and the communication circuit, respectively, the processor controlling itself and the memory and the communication circuit to implement the steps of the above method when in operation.
In order to solve the above technical problem, another technical solution adopted by the present application is: there is provided an apparatus having a storage function, storing program data executable to implement the steps in the above method.
The beneficial effect of this application is: the utility model provides a planning method of welding robot swing orbit has carried out the split with welding robot's swing orbit, the split is welding seam orbit and skew orbit, compare prior art and need not regard as every turning point as the teaching terminal point, it is simple to calculate, in addition, a plurality of second track points form the V type skew orbit that is located the YOZ plane under the swing coordinate system, the summit of V type skew orbit and the initial point coincidence of swing coordinate system, the opening is towards the Z axle positive half-axis of swing coordinate system, can realize welding robot's space V type pendulum motion.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts. Wherein:
FIG. 1 is a schematic flow chart illustrating an embodiment of a method for planning a swing path of a welding robot according to the present invention;
FIG. 2 is a schematic view of a tool coordinate system;
FIG. 3 is a schematic diagram of a tool path coordinate system;
FIG. 4 is a schematic diagram of an offset trajectory of the welding robot in a swinging coordinate system according to the present application;
FIG. 5 is a schematic diagram of the swing track of the welding robot in the workpiece coordinate system;
FIG. 6 is a schematic diagram of a swing track of the welding robot in an application scenario under a workpiece coordinate system;
FIG. 7 is a schematic diagram of a swing track of the welding robot in a workpiece coordinate system in another application scenario;
FIG. 8 is a schematic structural diagram of an embodiment of the welding robot of the present application;
fig. 9 is a schematic structural diagram of an embodiment of the device with a storage function according to the present application.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
Referring to fig. 1, fig. 1 is a schematic flow chart of an embodiment of a method for planning a swing path of a welding robot according to the present invention. The execution main body of the swing track planning method in the application is a welding robot, and the planning method comprises the following steps:
s110: and determining first position coordinates and first posture coordinates of a plurality of first track points on the welding seam under a workpiece coordinate system.
The welding robot advances along the extending direction of the welding seam and swings longitudinally relative to the welding seam in the process of welding the two workpieces to be welded. The workpiece coordinate system is a cartesian coordinate system fixed on the workpiece and is set by a designer, and in different application scenarios, the designer can set different workpiece coordinate systems. The first plurality of locus points are located on the weld seam and have no offset relative to the weld seam, and the first plurality of locus points form a weld seam locus completely coincident with the weld seam.
In an application scene, in the teaching process, the welding robot determines the poses of a plurality of first track points on a welding seam under a workpiece coordinate according to the pose of a welding starting point, the pose of a welding end point and the welding time/welding speed input by an operator, wherein the poses comprise first position coordinates and first attitude coordinates of the first track points. Wherein welding starting point and terminal point all are located the welding seam, and it is long for the welding of welding seam orbit during welding, expects that the welding robot walks to the time of welding terminal point along the welding seam from welding starting point promptly, and welding speed is linear velocity when expecting the welding robot to walk along the welding seam orbit.
S120: and determining the position coordinates of second track points corresponding to the first track points under the swinging coordinate system, wherein the second track points corresponding to the first track points have offset increment relative to the welding line, the second track points corresponding to the first track points form a V-shaped offset track positioned on the YOZ plane under the swinging coordinate system, the vertex of the V-shaped offset track coincides with the origin of the swinging coordinate system, and the opening faces to the Z-axis positive half shaft of the swinging coordinate system.
The second track points have offsets relative to the welding line, a one-to-one correspondence relationship exists between the first track points and the second track points, and the second track points form offset tracks of the welding robot under the swinging coordinate system.
The swing coordinate system may be a Tool coordinate system or a Tool path coordinate system, as shown in fig. 2, an origin of the Tool coordinate system is an end point of a welding gun of the welding robot, that is, a Tool Center Point (TCP), an X-axis direction of the Tool coordinate system is a forward direction of the welding gun, a Y-axis direction of the Tool coordinate system is a swing direction of the welding gun, and a Z-axis direction of the Tool coordinate system is a gun head direction of the welding gun.
Alternatively, the swing coordinate system may be a tool path coordinate system, and as shown in fig. 3, the same as the tool coordinate system, the origin of the tool path coordinate system is also the end point of the welding gun of the welding robot, and unlike the tool coordinate system, the X-axis direction is the tangential direction of the weld a, the Y-axis direction is determined by the cross-product of the X-axis direction of the tool path coordinate system and the Z-axis direction of the tool coordinate system, and the Z-axis direction is determined by the cross-product of the X-axis direction and the Y-axis direction of the tool path coordinate system.
It should be noted that the tool coordinate system is suitable for any application scenario, and the tool path coordinate system cannot be suitable when the tangential direction of the weld a is parallel to the Z-axis direction of the tool coordinate system.
In the welding process of the welding robot, the welding gun can rotate (in the rotating process, the direction of the gun head is unchanged), at the moment, if the swinging coordinate system is selected as a tool coordinate system, the swinging coordinate system can rotate around the Z axis, namely, the X axis direction and the Y axis direction are changed, further, the position coordinates of a plurality of second track points under the swinging coordinate are changed, and finally, the offset track of the welding robot is changed. However, since the Z-axis direction of the tool coordinate system does not change when the welding gun rotates, and since the tool path coordinate system is related only to the Z-axis direction of the tool coordinate system, the swing coordinate system can be selected as the tool path coordinate system if the deviation trajectory of the welding robot is not intended to change as the welding gun rotates.
S130: and converting the position coordinates of the second track point under the swinging coordinate system into second position coordinates under the workpiece coordinate system.
Since the two coordinate systems can be mutually converted, the position coordinates of the second track point in the swinging coordinate system can be converted into the second position coordinates in the workpiece coordinate system.
S140: and superposing the first position coordinates of the first track points and the second position coordinates of the corresponding second track points to obtain the position coordinates of the interpolation points corresponding to the first track points in the workpiece coordinate system, wherein the attitude coordinates of the interpolation points are the first attitude coordinates.
The first track point, the second track point and the interpolation point have one-to-one correspondence.
S150: and determining the planned swing track according to the position coordinates and the posture coordinates of the interpolation points.
And the welding robot forms a swing track according to the welding starting point, the welding end point and the interpolation point, and after the swing track is determined, the welding robot performs welding according to the swing track. The position coordinates of the interpolation points under the workpiece coordinate system are the second position coordinates of the second track points corresponding to the first position coordinates of the first track points in an overlapping mode, namely the final swing track of the welding robot is a welding track overlapping offset track.
Meanwhile, in the present embodiment, as shown in fig. 4, the plurality of second trajectory points form a V-shaped offset trajectory located on the YOZ plane under the swing coordinate system, the vertex of the V-shaped offset trajectory coincides with the origin of the swing coordinate system, and the opening faces the positive half axis of the Z axis of the swing coordinate system, so that as shown in fig. 5, the swing trajectory formed by superimposing the V-shaped offset trajectory on the welding trajectory is a spatial V-shaped trajectory, that is, in the present embodiment, the spatial V-shaped swing motion of the welding robot can be realized.
In the present embodiment, the position coordinates of the second track point in the swing coordinate system are multiplied by the transformation matrix of the workpiece coordinate system relative to the swing coordinate system to obtain the second position coordinates of the second track point in the workpiece coordinate system. Specifically, if the position coordinate of the second track point in the swing coordinate system is P, the position coordinate Q of the second track point in the workpiece coordinate system is M × P, where M is a transformation matrix of the workpiece coordinate system with respect to the swing coordinate system, and the transformation matrix M can be obtained from a kinematic positive solution of the robot.
Therefore, if the first position coordinate of the first track points on the weld in the workpiece coordinate system is R, the position coordinate of the interpolation point corresponding to the first track point in the workpiece coordinate system is S ═ R + Q ═ R + M × P.
In this embodiment, step S120 specifically includes:
s121: obtaining the welding time duration, the swing period T, the swing amplitude A, the opening included angle theta and the first staying time T1A second residence time t2And a third dwell time t3。
The opening included angle theta is the opening included angle of the V-shaped offset track in the YOZ plane in the swinging coordinate system.
In one application scenario, before planning a track, the robot directly receives a welding duration input by a user, and in another application scenario, the robot calculates the welding duration according to a welding start point pose, a welding end point pose and a welding speed input by the user.
S122: and calculating the interpolation time point of each of the first track points.
The interpolation time point is the time point of the first track point in the whole welding process. The interpolation time points of the first track points are all between 0 and duration, and the smaller the interpolation time point corresponding to the first track point is, the closer the first track point is to the welding starting point is.
S123: calculating the time point of each of the first track points in a wobble cycle according to the following formula:
the formula I is as follows: t is time-round (time/cycle) cycle, where T is a time point of each of the first track points in a wobble cycle, time is an interpolation time point of each of the first track points, round is a downward rounding function, cycle is a duration of a wobble cycle, and cycle is T + T1+2*t2+t3。
The wobble track is repeatedly changed according to the smallest repeating unit, i.e. a wobble cycle. Corresponding to the swing track, the offset track formed by the second track points is repeatedly changed according to the minimum repeating unit, wherein the time length and the starting time point of the minimum repeating unit of the swing track are the same as those of the minimum repeating unit of the offset track formed by the second track points.
In this application, when the welding robot carries out the space V-shaped pendulum motion, in the minimum repeating unit of skew orbit, the welding robot can stop 4 times: respectively staying at different sides of the deviated welding seam once and staying at the welding seam twice, wherein the staying time at different sides of the deviated welding seam is t1And t3The time of stay at the weld seam is t2So that the total dwell time of the welding robot is t within the smallest repeating unit of the offset trajectory1+2*t2+t3Thus the minimum repeating unit of the offset trajectory has a duration of T + T1+2*t2+t3The duration is also the duration of the smallest repeating unit of the wobble track.
S124: and calculating the offset increment of the second track point corresponding to each first track point along the Y axis and the offset increment along the Z axis under the swinging coordinate system by using the time point of each first track point in one swinging cycle as an independent variable and using a direct proportion function or a sine function.
And calculating the offset increment of the corresponding second track point along the Y axis and the offset increment along the Z axis in the swinging coordinate system by taking the time point t of each first track point in one swinging cycle as an independent variable, namely substituting the time point t of each first track point in one swinging cycle into a proportional function or a sine function to calculate the offset increment of the corresponding second track point along the Y axis and the offset increment along the Z axis in the swinging coordinate system.
When the deviation increment is calculated by using the direct proportional function, the swing track of the final welding robot is changed linearly, so that the acceleration of the welding robot at the turning point is high in the welding process, and the service life of the welding robot is easily influenced. And the sine function changes smoothly at the wave crest and the wave trough, so when the sine function is adopted to calculate the offset increment, the acceleration of the final welding robot at the turning point in the welding process is slowed down, the abrasion of the welding robot in the welding process is reduced, and the service life of the welding robot is prolonged.
S125: and determining the position coordinates of the second track points corresponding to the plurality of first track points in the swinging coordinate system.
Specifically, the position coordinate P of the second track point corresponding to the plurality of first track points in the swinging coordinate system is [ 0Y Z ═ P]TAnd Y is the offset increment of the second track point corresponding to the first track point along the Y axis under the swinging coordinate system, and Z is the offset increment of the second track point corresponding to the first track point along the Z axis under the swinging coordinate system. The coordinates of the interpolation point corresponding to the first locus point in the workpiece coordinate system are therefore S ═ R + Q ═ R + M [ 0Y Z ]]T。
In an application scene, the following direct proportional function is used for calculating the offset increment of a second track point corresponding to each of a plurality of first track points along the Y axis and the offset increment of the Z axis under a swinging coordinate system:
the formula II is as follows:
the formula III is as follows:
wherein Y is a plurality ofAnd the second track points corresponding to the first track points are in the offset increment of the swing coordinate system along the Y axis, Z is the offset increment of the second track points corresponding to the first track points respectively along the Z axis under the swing coordinate, and m is the offset increment of the second track points corresponding to the first track points respectively along the Z axis1＝T/4，m2＝m1+t1,m3＝m2+T/4，m4＝m3+t2，m5＝m4+T/4，m6＝m5+t3，m7＝m6+T/4。
In the application scenario, when the first dwell time t1A second residence time t2And a third dwell time t3When both are zero, the finally formed wobble track is shown in fig. 5. When the positions of the swing tracks are all zero, the welding robot stays in the welding process, and the finally formed swing tracks are shown in fig. 6.
In another application scenario, the following sine function is used to calculate the offset increment of the second track point corresponding to each of the plurality of first track points along the Y axis and the offset increment along the Z axis in the swinging coordinate system:
the formula four is as follows:
the formula five is as follows:
y is the offset increment of the second track points corresponding to the first track points respectively along the Y axis under the swinging coordinate system, Z is the offset increment of the second track points corresponding to the first track points respectively along the Z axis under the swinging coordinate system, and m is the offset increment of the second track points corresponding to the first track points respectively along the Z axis under the swinging coordinate system1＝T/4，m2＝m1+t1,m3＝m2+T/4，m4＝m3+t2，m5＝m4+T/4，m6＝m5+t3，m7＝m6+T/4。
The final swing path of the welding robot at this time is shown in fig. 7.
From the two application scenariosIt can be seen that when the first dwell time t is reached1A second residence time t2And a third dwell time t3When the swing track of the welding robot is not zero, the swing track of the welding robot is divided into 8 sections in one cycle: 0 to m1、m1～m2、m2～m3、m3～m4、m4～m5、m5～m6、m6～m7And m7Cycle. Wherein, in m3～m4And m7The welding robot returns to the weld seam in the cycle section.
Meanwhile, it can also be seen from the above that, at the end of each swing cycle, the welding robot will return to the weld, and usually, due to the process requirement, the welding robot will require that it return to the weld after the welding is finished, that is, the welding duration is required to be an integral multiple of the duration cycle of the swing cycle, but in an application scenario, when the user does not directly input the welding duration, for example, the welding robot calculates the welding duration according to the pose of the welding start point, the pose of the welding end point and the welding speed input by the user, the welding duration may not be an integral multiple of the duration cycle of the swing cycle, and then at the end of the welding, the welder may shift the weld, and an unexpected effect may not be achieved. Therefore, in order to solve the problem and ensure that the welding robot can move right onto the welding seam when the swing track is finished, the method in this embodiment further comprises:
s160: the difference between the duration and round (duration/cycle) cycles is calculated and denoted as mini _ cycle.
S170: judging whether the mini _ cycle is 0, if so, respectively determining the offset increment of second track points corresponding to the first track points along the Y axis and the Z axis under the swinging coordinate system according to a formula II and a formula III, or determining the offset increment of the second track points corresponding to the first track points along the Y axis and the Z axis under the swinging coordinate system according to a formula IV and a formula V, otherwise, judging the mini _ cycle and the m7The size of (2).
S180: if the mini _ cycle is more than or equal to m7According to the formula IIAnd determining the offset increment of the second track point corresponding to each of the first track points along the Y axis and the Z axis under the swinging coordinate system according to a third formula, or determining the offset increment of the second track point corresponding to each of the first track points along the Y axis and the Z axis under the swinging coordinate system according to a fourth formula and a fifth formula, or reducing the swinging period and the swinging amplitude of at least part of the first track points with the interpolation time point being greater than (duration-mini _ cycle) so as to calculate the offset increment of the corresponding second track point along the Y axis and the Z axis under the swinging coordinate system.
Specifically, round is a rounded down function, and round (duration/cycle) cycle is the total duration of all complete oscillation cycles in the entire welding process. If the mini _ cycle is 0, the welding time duration is integral multiple of the time duration cycle of the swing cycle, the welding robot will return to the welding seam after the welding is finished, and then the offset increment of the second track point corresponding to each of the first track points along the Y axis and the Z axis under the swing coordinate system is determined according to a formula two and a formula three, or the offset increment of the second track point corresponding to each of the first track points along the Y axis and the Z axis under the swing coordinate system is determined according to a formula four and a formula five.
If the mini _ cycle is not 0, it indicates that the last swing cycle is not a complete swing cycle, and there is a possibility that the welding robot will not return to the weld at the end, so we need to return the welding robot to the weld in the last swing cycle, i.e. make the welding robot perform a "return-to-zero swing" in the last swing cycle, where the duration of the return-to-zero swing is mini _ cycle and the starting time point is (duration-mini _ cycle), i.e. when the interpolation time point is less than (duration-mini _ cycle), the welding robot performs the return-to-zero swing according to formulas two and three, or according to formulas four and five normal swings, and when the interpolation time point is greater than (duration-mini _ cycle).
Meanwhile, as can be seen from the above, the welding robot is in m7Will return to the weld seam in the cycle section, so when the mini _ cycle is more than or equal to m7At this time, although the last oscillation cycle is not completedAnd (3) the whole swinging cycle is carried out, but the welding robot can still return to the welding seam at the end of welding, so that the welding robot still swings normally when carrying out zero-resetting swinging, namely, the deviation increment of the corresponding second track point along the Y axis and the Z axis under the swinging coordinate system is determined according to formulas two and three or according to formulas four and five.
When the mini _ cycle is less than m7During, welding robot can not get back to the welding seam when the welding is finished this moment, then dwindles swing cycle and swing amplitude to at least partial first track point to the second track point that calculates to correspond is along the skew increment of Y axle under the swing coordinate system, that is to say, compares preceding normal swing, and welding robot is when carrying out the swing of returning to zero, and its cycle, amplitude can reduce, can get back to on the welding seam when guaranteeing to stop welding at last.
In an application scenario, the step of reducing the wobble period and the wobble amplitude for at least a portion of the first track points with interpolation time points greater than (duration-mini _ cycle) in step S180 to calculate the offset increments of the corresponding second track points along the Y axis and the Z axis in the wobble coordinate system includes:
s181: judging mini _ cycle and m3The size of (2).
S182: if mini _ cycle is greater than m3The interpolation time is greater than (duration-mini _ cycle) and corresponds to a time within one wobble cycle being less than or equal to m3Respectively determining the offset increment of the second track point corresponding to each of the plurality of first track points along the Y axis and the Z axis under the swinging coordinate system according to a formula two and a formula three, or determining the offset increment of the second track point corresponding to each of the plurality of first track points along the Y axis and the Z axis under the swinging coordinate system according to a formula four and a formula five, wherein the interpolation time point is greater than (duration-mini _ cycle) and the time point corresponding to one swinging cycle is greater than m3And is less than or equal to m7And reducing the swing period and the swing amplitude to calculate the offset increment of the corresponding second track point along the Y axis and the Z axis under the swing coordinate system.
S183: if the mini _ cycle is greater than 0 and less than m3Then pairAnd interpolating a first track point with a time point larger than (duration-mini _ cycle), and reducing the swing period and the swing amplitude to calculate the offset increment of the corresponding second track point along the Y axis and the Z axis under the swing coordinate system.
When mini _ cycle is greater than or equal to m3Less than m7In the process, the welding robot can still complete 0-m of normal swing when performing zero return swing3Stage, therefore, when performing return-to-zero wobbling, is less than or equal to m for the time point corresponding to within one wobbling cycle3The corresponding offset increment is still calculated according to the formulas two and three, or according to the formulas four and five, and the corresponding time point in a swing cycle is larger than m3And is less than or equal to m7The wobble period and the wobble amplitude are reduced, specifically, when the mini _ cycle is m or more3Is less than or equal to m7And then, determining the offset increment of the corresponding second track point along the Y axis and the offset increment along the Z axis in the swinging coordinate system according to the following formula six and formula seven, or determining the offset increment of the corresponding second track point along the Y axis and the offset increment along the Z axis in the swinging coordinate system according to the formula eight and the formula nine:
formula six:
the formula seven:
the formula eight:
the formula is nine:
wherein n is1＝m3+0.25*Tmin，n2＝n1+2*Tmin/cycle*t3，n3＝n2+0.25*Tmin，n4＝n3+2*Tmin/cycle*t2，Amin＝A*(2*Tmin/cycle)Tmin＝2*((mini_cycle-m3)-2*(mini_cycle-m3)/cycle*t3)。
As can be seen from the above formulas six to nine, it is in the range of 0 to m3Within a segment, the offset increments are still the same as the above equations two and three, and equations four and five, when t is>m3The wobble period and wobble amplitude are reduced to calculate the offset increment.
When the mini _ cycle is less than m3During zero-resetting swinging, the swinging period and the swinging amplitude of the welding robot are directly reduced, specifically, the offset increment of the corresponding second track point along the Y axis and the offset increment along the Z axis under the swinging coordinate system are calculated according to the following formulas ten and eleven, or the offset increment of the corresponding second track point along the Y axis and the offset increment along the Z axis under the swinging coordinate system are calculated according to the formulas twelve and thirteen:
formula ten:
formula eleven:
equation twelve:
formula thirteen:
wherein p is1＝0.25*Tmin，p2＝p1+2*Tmin/cycle*t1，p3＝p2+0.25*Tmin，p4＝p3+2*Tmin/cycle*t2，Amin＝A*(2*Tmin/cycle)，Tmin＝2*(mini_cycle-2*mini_cycle/cycle*t1)。
From the above, it can be seen that the method in the present embodiment can ensure that the welding robot returns to the welding seam at the end of welding to achieve the desired swing track.
In other embodiments, when the welding robot needs to return to the welding seam by performing the zero-returning swing, the mini _ cycle and m need not to be judged7、m3The first track point with the interpolation time point larger than the duration-mini _ cycle is directly reduced in the swing period and the swing amplitude, that is, when the welding robot performs the return-to-zero swing, the period and the amplitude are directly reduced to swing compared with the normal swing, so that the welding robot can finally return to the welding seam.
Referring to fig. 8, fig. 8 is a schematic structural diagram of an embodiment of the welding robot of the present application. The welding robot 200 includes a processor 210, a memory 220, and a communication circuit 230, wherein the processor 210 is coupled to the memory 220 and the communication circuit 230, respectively, and the processor 210 controls itself, the memory 220, and the communication circuit 230 to implement the steps in the method for planning the swing trajectory during operation.
Referring to fig. 9, fig. 9 is a schematic structural diagram of an embodiment of a device with a storage function according to the present application. The apparatus 300 with storage function stores program data 310, and the program data 310 can be executed to implement the steps in the above-mentioned swing trajectory planning method, and the detailed planning method can refer to the above-mentioned embodiment and is not described herein again.
The utility model provides a planning method of welding robot swing orbit has carried out the split with welding robot's swing orbit, the split is welding seam orbit and skew orbit, compare prior art and need not regard as every turning point as the teaching terminal point, it is simple to calculate, in addition, a plurality of second track points form the V type skew orbit that is located the YOZ plane under the swing coordinate system, the summit of V type skew orbit and the initial point coincidence of swing coordinate system, the opening is towards the Z axle positive half-axis of swing coordinate system, can realize welding robot's space V type pendulum motion.
The above embodiments are merely examples and are not intended to limit the scope of the present disclosure, and all modifications, equivalents, and flow charts using the contents of the specification and drawings of the present disclosure or those directly or indirectly applied to other related technical fields are intended to be included in the scope of the present disclosure.
Claims (9)
1. A method for planning a swing path of a welding robot, the method comprising:
determining first position coordinates and first attitude coordinates of a plurality of first track points on a welding seam under a workpiece coordinate system;
determining the position coordinates of second track points corresponding to the first track points under a swinging coordinate system, wherein the second track points corresponding to the first track points have offset increment relative to the welding line, the second track points corresponding to the first track points form a V-shaped offset track on a YOZ plane under the swinging coordinate system, the vertex of the V-shaped offset track is overlapped with the origin of the swinging coordinate system, and the opening faces to a Z-axis positive half shaft of the swinging coordinate system;
converting the position coordinates of the second track points under the swinging coordinate system into second position coordinates under the workpiece coordinate system;
superposing the first position coordinates of the first track points and the corresponding second position coordinates of the second track points to obtain position coordinates of interpolation points corresponding to the first track points in the workpiece coordinate system, wherein the attitude coordinates of the interpolation points are the first attitude coordinates;
determining a planned swing track according to the position coordinates and the posture coordinates of the interpolation points;
the system comprises a swinging coordinate system, a welding gun head, a welding gun and a welding gun, wherein the swinging coordinate system is a tool coordinate system, the origin of the swinging coordinate system is an endpoint of the welding gun, the X-axis direction is the advancing direction of the welding gun, the Y-axis direction is the swinging direction of the welding gun, and the Z; or, the swing coordinate system is a tool path coordinate system, the origin of the swing coordinate system is the end point of the welding gun, the X-axis direction is the tangential direction of the welding seam, the Y-axis direction is determined by the cross multiplication of the X-axis direction of the tool path coordinate system and the Z-axis direction of the tool coordinate system, and the Z-axis direction is determined by the cross multiplication of the X-axis direction and the Y-axis direction of the tool path coordinate system;
the determining of the position coordinates of the second track points corresponding to the first track points under the swinging coordinate system comprises the following steps:
obtaining the welding time duration, the swing period T, the swing amplitude A, the opening included angle theta and the first staying time T1A second residence time t2And a third dwell time t3；
Calculating respective interpolation time points of the first track points;
calculating the time point of each of a plurality of first track points in a wobble cycle according to the following formula:
the formula I is as follows: t is time-round (time/cycle) cycle, where T is a time point of each of the first track points in a wobble cycle, time is an interpolation time point of each of the first track points, round is a downward rounding function, cycle is a duration of a wobble cycle, and cycle is T + T1+2*t2+t3；
The time points of the first track points in one swing cycle are used as independent variables, and a proportional function or a sine function is used for calculating the offset increment of the second track points corresponding to the first track points along the Y axis and the offset increment along the Z axis in the swing coordinate system;
and determining the position coordinates of second track points corresponding to the first track points under the swinging coordinate system.
2. The planning method according to claim 1, wherein the step of calculating, using a proportional function, an incremental offset along the Y axis and an incremental offset along the Z axis of the second track point corresponding to each of the first track points in the wobble coordinate system, with a time point of each of the first track points in one wobble cycle as an argument, includes:
calculating the offset increment of the second track point corresponding to each of the first track points along the Y axis under the swinging coordinate system according to the following formula II, and calculating the offset increment of the second track point corresponding to each of the first track points along the Z axis under the swinging coordinate system according to the following formula III:
the formula II is as follows:
the formula III is as follows:
wherein, Y is a plurality of the second track point that first track point corresponds respectively is in along the skew increment of Y axle under the swing coordinate system, Z is a plurality of the second track point that first track point corresponds respectively is in along the skew increment of Z axle under the swing coordinate, m1＝T/4，m2＝m1+t1,m3＝m2+T/4，m4＝m3+t2，m5＝m4+T/4，m6＝m5+t3，m7＝m6+T/4。
3. The planning method according to claim 1, wherein the step of calculating, by using a sine function, an incremental offset along the Y axis and an incremental offset along the Z axis of the second track point corresponding to each of the first track points in the wobble coordinate system, with a time point of each of the first track points in one wobble cycle as an argument, includes:
calculating the offset increment of the second track point corresponding to each of the first track points along the Y axis in the swinging coordinate system according to the following formula IV, and calculating the offset increment of the second track point corresponding to each of the first track points along the Z axis in the swinging coordinate system according to the following formula V:
the formula four is as follows:
the formula five is as follows:
wherein, Y is a plurality of the second track point that first track point corresponds respectively is in along the skew increment of Y axle under the swing coordinate system, Z is a plurality of the second track point that first track point corresponds respectively is in along the skew increment of Z axle under the swing coordinate, m1＝T/4，m2＝m1+t1,m3＝m2+T/4，m4＝m3+t2，m5＝m4+T/4，m6＝m5+t3，m7＝m6+T/4。
4. A planning method according to claim 2 or 3, characterized in that the method further comprises:
calculating the difference value between the duration and the round (duration/cycle) cycle, and marking the difference value as a mini _ cycle;
judging whether the mini _ cycle is 0, if the mini _ cycle is 0, respectively determining a plurality of second track points corresponding to the first track points respectively according to a formula II and a formula III, or determining a plurality of second track points corresponding to the first track points respectively according to a formula IV and a formula V, and if not, judging the mini _ cycle and the m7The size of (d);
if the mini _ cycle is more than or equal to m7According to said publicationAnd determining a plurality of second track points corresponding to the first track points respectively by a formula II and a formula III, or determining a plurality of second track points corresponding to the first track points respectively by a formula IV and a formula V under the swinging coordinate system along the Y axis and along the Z axis, or reducing the swinging period and the swinging amplitude of at least part of the first track points with interpolation time points larger than (duration-mini _ cycle) to calculate the deviation increment of the corresponding second track points along the Y axis and the Z axis under the swinging coordinate system.
5. The planning method according to claim 4, wherein the step of reducing the wobble period and the wobble amplitude for at least some first track points having interpolation time points greater than (duration-mini _ cycle) to calculate the offset increment of the corresponding second track point along the Y-axis and the Z-axis in the wobble coordinate system comprises:
judging mini _ cycle and m3The size of (d);
if mini _ cycle is greater than m3The interpolation time is greater than (duration-mini _ cycle) and corresponds to a time within one wobble cycle being less than or equal to m3According to the second formula and the third formula, determining a plurality of second track points corresponding to the first track points respectively along the Y axis and the offset increment along the Z axis under the swinging coordinate system, or according to the fourth formula and the fifth formula, determining a plurality of second track points corresponding to the first track points respectively along the Y axis and the offset increment along the Z axis under the swinging coordinate system, wherein the interpolation time point is larger than (duration-mini _ cycle) and is larger than m corresponding to the time point in one swinging cycle3And is less than or equal to m7The swing period and the swing amplitude are reduced to calculate the offset increment of the corresponding second track point along the Y axis and the Z axis under the swing coordinate system;
if the mini _ cycle is greater than 0 and less than m3If the interpolation time point is larger than the first track point of the (duration-mini _ cycle), the wobble period is reducedAnd the swing amplitude is used for calculating the offset increment of the corresponding second track point along the Y axis and the Z axis under the swing coordinate system.
6. A planning method according to claim 2 or 3, characterized in that the first dwell time t1A second residence time t2And a third dwell time t3Equal, both are zero or both are non-zero.
7. The method of planning according to claim 1, wherein said converting the position coordinates of the second trajectory point in the oscillating coordinate system to second position coordinates in the workpiece coordinate system comprises:
and the position coordinate of the second track point under the swinging coordinate system is multiplied by a transformation matrix of the workpiece coordinate system relative to the swinging coordinate system to obtain the second position coordinate of the second track point under the workpiece coordinate system.
8. A welding robot comprising a processor, a memory and a communication circuit, the processor being coupled to the memory and the communication circuit, respectively, the processor being operative to control itself and the memory, the communication circuit implementing the steps of the method of any one of claims 1-7.
9. An apparatus having a storage function, characterized in that program data are stored, which program data can be executed to implement the steps in the method according to any of claims 1-7.
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