Multi-axis machine tool and method for moving its head

Abstract

The present application relates to a multi-axis machine tool and a machining head movement control method thereof. The machining head movement control method of the multi-axis machine tool comprises the steps of: a) lifting the machining head in the Z-axis direction by the lifting shaft of the machine tool; b) after the machining head is lifted to a safe height, moving the machining head to a target position in the X-axis and Y-axis directions respectively by the translation shaft of the machine tool, and rotating the machining head to a target posture by the rotation shaft of the machine tool, wherein the safe height is selected so that the machining head does not collide during the movement of the translation shaft and the rotation shaft; and c) after the machining head reaches a descending starting position, starting to lower the machining head in the Z-axis direction by the lifting shaft until the machining head moves to the target position in the X-axis, Y-axis and Z-axis directions and rotates to the target posture in the rotation direction, wherein step a) continues or does not continue while step b) is performed, and step b) continues or does not continue while step c) is performed.

Description

Technical Field

[0001] This invention relates to the field of machine tools, and more specifically to multi-axis machine tools and a method for controlling the movement of the machining head of a multi-axis machine tool. Background Technology

[0002] Machine tool processing plays a crucial role in modern mechanical manufacturing. Parts requiring high precision and fine surface roughness generally need to be processed on a machine tool using a machining head. To process a workpiece, such as cutting out specific patterns, the machining head needs to be moved frequently to process different patterns at different positions.

[0003] However, the surface of the workpiece to be machined is not completely flat and smooth. If the machining head is moved at the same height or in a "following" state (the distance between the machining head and the machined surface remains constant), it may accidentally collide with the workpiece when encountering a protrusion, depression, deformation, or tilt on the surface, thereby damaging or even scrapping the machining head. Such collisions include, but are not limited to: the machining head colliding laterally with other objects during translation; the machining head colliding with other objects during rotation; and the machining head entering a hole in the following state, rendering the capacitive sensor used for following ineffective, causing the machining head to collide with the edge of the hole. All of these can damage the machining head, resulting in significant losses for the manufacturer.

[0004] To prevent the aforementioned safety accidents, multi-axis machine tools typically employ the safest method to move the machining head: after each pattern is machined, the machining head is returned to its highest position via the lifting axis. Only after the machining head has moved to the starting point of the next pattern to be machined in other axes does the lifting axis begin to descend (or start following). This method of moving the machining head is obviously too slow, significantly impacting the machine tool's machining efficiency.

[0005] Therefore, there is an urgent need for a new technology that can maximize machine tool processing efficiency while ensuring safety. Summary of the Invention

[0006] The present invention aims to overcome the above-mentioned and / or other problems in the prior art. The machining head movement control method and multi-axis machine tool provided by the present invention can greatly increase the movement speed of the machining head while ensuring safety, thereby significantly improving the machining efficiency of the machine tool.

[0007] According to a first aspect of the present invention, a method for controlling the movement of a machining head of a multi-axis machine tool is provided, comprising the following steps: a) raising the machining head in the Z-axis direction via a lifting axis of the machine tool, wherein the Z-axis direction is vertical; b) after the machining head has risen to a safe height, moving the machining head towards a target position in the X-axis and Y-axis directions via a translation axis of the machine tool, and rotating the machining head towards a target posture via a rotation axis of the machine tool, wherein the X-axis and Y-axis are perpendicular to each other and the plane formed by them is perpendicular to the Z-axis, wherein the safe height is selected such that the machining head does not collide during the movement of the translation axis and the rotation axis; and c) after the machining head reaches the lowering open position, lowering the machining head in the Z-axis direction via the lifting axis until the machining head has moved to the target position in the X-axis, Y-axis and Z-axis directions and rotated to the target posture in the rotation direction, wherein step a) may continue or not continue while step b) is performed, and step b) may continue or not continue while step c) is performed.

[0008] According to a second aspect of the present invention, a multi-axis machine tool is provided, comprising: a machining head; a lifting axis for lifting the machining head in the Z-axis direction, the Z-axis direction being vertical; a translation axis for moving the machining head in the X-axis and Y-axis directions, the X-axis and Y-axis being perpendicular to each other and the plane formed by them being perpendicular to the Z-axis; a rotary axis for rotating the machining head; and a controller for controlling the machining head to move to a target position in a manner in which the lifting axis, translation axis and rotary axis cooperate with each other. The controller's control includes: controlling the lifting axis to raise the machining head in the Z-axis direction; after the machining head rises to a safe height, controlling the translation axis to move the machining head towards the target position in the X-axis and Y-axis directions respectively, and controlling the rotation axis to rotate the machining head towards the target posture, while continuing to control the lifting axis to rise or remain stationary, wherein the selection of the safe height ensures that the machining head will not collide during the movement of the translation axis and the rotation axis; and after the machining head reaches the descent open position, controlling the lifting axis to begin descending the machining head in the Z-axis direction, while continuing to control the translation axis to move the machining head towards the target position and controlling the rotation axis to rotate the machining head towards the target posture or controlling the translation axis and the rotation axis to remain stationary, until the machining head has moved to the target position in the X-axis, Y-axis and Z-axis directions and rotated to the target posture in the rotation direction.

[0009] Compared to existing multi-axis machine tools that use a serial method to link the movements of the lifting, translation, and rotary axes, this invention cleverly uses a near-parallel method to link the movements of the lifting, translation, and rotary axes. This significantly shortens the time it takes for the machining head to move to the target position while ensuring safety, thus significantly improving machining efficiency.

[0010] In particular, this invention saves a significant amount of time compared to the waiting time for the lifting shaft and the waiting time for the translational and rotational shafts, as well as the waiting time for the lifting shaft and translational and rotational shafts, which are present in the prior art. This invention can shorten both waiting times simultaneously, or selectively shorten either one. For example, the aforementioned safety height can be selected as the highest position of the lifting shaft, and the translational and rotational shafts are not fully moved into position at the descent opening position. In this case, the lifting shaft remains stationary while the translational and rotational shafts begin to move. Alternatively, the descent opening position can be defined as the position where both the translational and rotational shafts are fully moved, and the safety height is lower than the highest position of the lifting shaft. In this case, the translational and rotational shafts remain stationary while the lifting shaft descends.

[0011] The aforementioned safety heights may include translational start heights and rotational start heights, corresponding to the safe starting heights for translational axis movement and rotational axis movement, respectively. Unlike existing technologies where the lifting axis must fully return to its highest position before other axes begin movement, in this invention, once the machining head reaches the translational start height, the translational axis can be controlled to begin moving the machining head towards the target position in the X and Y axes, respectively. Then, when the machining head further reaches the rotational start height, the rotational axis is controlled to begin rotating the machining head towards the target posture. In this case, the rotational start height is greater than the translational start height. Alternatively, the rotational start height can be less than the translational start height; that is, the machining head first begins rotating towards the target posture under the drive of the rotational axis, and after rising a certain distance, it begins moving towards the target position in the X and Y axes under the drive of the translational axis. Of course, it is also possible to choose a rotational start height equal to the translational start height, which is equivalent to simultaneously initiating the machining head's rotation towards the target posture and its movement towards the target position in the X and Y axes.

[0012] When the rotation start height is greater than the translation start height, it is safe to begin translation along the X and Y axes at the rotation start height. Therefore, it is also possible to control the translation axis to move the machining head towards the target position along the X and Y axes only after the machining head reaches the rotation start height, while simultaneously controlling the rotation axis to rotate the machining head towards the target orientation. Similarly, when the rotation start height is less than the translation start height, it is also safe to begin rotation along the rotation axis at the translation start height. Therefore, it is also possible to control the rotation axis to rotate the machining head towards the target orientation only after the machining head reaches the translation start height, while simultaneously controlling the translation axis to move the machining head towards the target position along the X and Y axes.

[0013] Both of the above methods can shorten the time it takes for the processing head to move to the target position while ensuring safety. However, it is obvious that starting the translational motion at the translational starting height and starting the rotational motion at the rotational starting height can save more waiting time.

[0014] The translation start height is determined by ensuring that the machining head can begin its translational movement along the X and Y axes at a specific height without colliding. If the workpiece is very flat, the translation start height can be 0. If the workpiece is not flat, the translation start height can be chosen to prevent the machining head from colliding with it (hereinafter referred to as the "translation collision height"). Because the lifting axis continues to rise after the translation begins, the machining head can also begin translating at a position below the translation collision height; that is, the translation start height can be chosen to be less than the translation collision height, as long as the machining head rises to the translation collision height before reaching the collision position.

[0015] The rotary start height can be the height H at which the machining head reaches the translation start height. 平移启动 The height reached after further ascent. This further ascent height can be the lifting height H required for the machining head to rotate to the target posture. 旋转上抬 The machining head rotation to the target posture can include several scenarios: the machining head swings directly down to the target posture; the machining head needs to be aligned (parallel to the vertical direction) before swinging up to the target posture (including the alignment posture itself); and the machining head swings directly up to the target posture. In the case where the machining head swings directly down to the target posture, the height of the machining head relative to the machining surface gradually decreases. Therefore, the machining head needs to be raised a certain height along the Z-axis to ensure it does not collide with the machining surface. This minimum height is H. 旋转上抬In cases where the machining head needs to be aligned before being moved to the target orientation, the height of the machining head relative to the machining surface will gradually decrease initially, reaching its minimum at the aligned position. Then, during the subsequent upward movement, the height will gradually increase again (unless the target orientation is already aligned). Therefore, in this situation, H... 旋转上抬 This should be the minimum height that the machining head needs to rise further in the Z-axis direction to ensure it won't collide with the machining surface while in a centered position. When the machining head is directly swung to the target position, the height of the machining head relative to the machining surface gradually increases. Therefore, even if the machining head doesn't rise further in the Z-axis direction, a collision won't occur. So H... 旋转上抬 It can be 0.

[0016] The machining head starts from a translational height H 平移启动 The above H continued to rise 旋转上抬 This ensures that the machining head will not collide with the machining surface during subsequent rotation towards the target orientation. However, in actual operation, it also takes time for the machining head to rotate to the target orientation (enter the correct position). Therefore, an adjustment coefficient Coeff can be set to adjust the rotation start-up height H. 旋转启动 =H 平移启动 +H 旋转上抬 *Coeff (0≤Coeff≤1). When Coeff=1, the rotation start height H 旋转启动 Still H 平移启动 H continued to rise 旋转上抬 When Coeff < 1, the processing head rises by less than H. 旋转上抬 The rotation begins at a certain height, and when it has fully risen to H... 旋转上抬 It can rotate to the correct position or be aligned at the correct time (rotation means moving from the aligned position to the target position), or it may take a little more time to rotate to the correct position or be aligned. That is, the machining head moves from the H position in the Z-axis direction. 旋转启动 Continue to rise H 旋转上抬 The time taken to reach the height of (1-Coeff) is less than or equal to the time taken for the machining head to rotate from its current position to the target position or to be aligned. In this way, the time it takes for the machining head to move to the target position can be further reduced. Furthermore, when Coeff = 0, H... 旋转上抬 *Coeff=0, the processing head reaches H 平移启动 It is not necessary to continue rising thereafter; this situation may include H. 平移启动 This could be due to the height being already high, or, as mentioned earlier, the rotation being a direct upward swing to the target posture.

[0017] The rotation start height can also be less than the translation start height H. 平移启动The height of the machining head, i.e., before the translational motion in the X and Y axes begins, is driven by the rotary axis to rotate towards the target posture. For example, in the case where the rotation is a direct upward swing to the target posture as described above, even if the machining head does not lift, it will not collide with the machining surface during the rotation. Therefore, the movement of the rotary axis can start earlier, or even start simultaneously with the lifting axis. This can further shorten the time for the machining head to move into position while ensuring safety.

[0018] Unlike existing technologies that wait for all other axes to reach their positions before the lifting shaft begins to descend from its highest position, in this invention, the lifting shaft can begin descending as soon as the machining head is in the descent open position. To further shorten the machining head's movement time while ensuring safety, the remaining time required for the machining head to move from the descent open position to the target position in the X and Y axes, and to rotate from the posture corresponding to the descent open position to the target posture, is less than the remaining time required for the lifting shaft to descend to its lowest point.

[0019] According to a third aspect of the invention, a computer-readable storage medium is provided having encoded instructions recorded thereon, which, when executed, implement the processing head movement method and processing method according to the invention as described above.

[0020] Other features and aspects of the invention will become clearer from the following detailed description taken in conjunction with the accompanying drawings. Attached Figure Description

[0021] The invention can be better understood by describing exemplary embodiments of the invention in conjunction with the accompanying drawings, in which:

[0022] Figure 1 A flowchart of a method for controlling the movement of a machining head in a multi-axis machine tool according to the present invention;

[0023] Figure 2 This is a schematic diagram illustrating the control of the machining head movement in a multi-axis machine tool according to the present invention.

[0024] Figures 3(a) to 3(d) Several scenarios for starting the machining head translation of a multi-axis machine tool are shown;

[0025] Figures 4(a) to 4(c) Several scenarios are shown that may occur when the machining head rotates to the target orientation;

[0026] Figure 5 A timing diagram illustrating an example of controlling the movement of a machining head in a multi-axis machine tool according to the present invention is shown; and

[0027] Figure 6 A schematic block diagram of a multi-axis machine tool according to the present invention is shown. Detailed Implementation

[0028] The present invention will be further described below with reference to specific embodiments and accompanying drawings. More details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention can obviously be implemented in many other ways different from those described herein. Those skilled in the art can make similar extensions and derivations based on actual application situations without departing from the spirit of the present invention. Therefore, the scope of protection of the present invention should not be limited by the content of this specific embodiment.

[0029] Unless otherwise defined, the technical or scientific terms used in the claims and description shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in the description and claims of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms "an" or "a" and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" and similar terms mean that the element or object preceding "comprising" or "including" encompasses the element or object listed following "comprising" or "including" and its equivalents, and do not exclude other elements or objects. The terms "connected" or "linked" and similar terms are not limited to physical or mechanical connections, nor are they limited to direct or indirect connections.

[0030] According to an embodiment of the present invention, a method for controlling the movement of the machining head of a multi-axis machine tool is provided.

[0031] refer to Figure 1 The invention illustrates a method 100 for controlling the movement of a machining head in a multi-axis machine tool. The method 100 includes steps 120 to 160.

[0032] In step 120, the machining head is raised in the Z-axis direction (vertical direction) by the machine tool's lifting axis. Generally, the machining surface is horizontal, therefore this Z-axis direction is usually perpendicular to the machining surface.

[0033] Figure 2 The diagram illustrates the various stages of movement of a multi-axis machine tool machining head. The lifting axis controls the machining head's movement along the Z-axis, the translational axis controls its translation along the X and Y axes, and the rotary axis controls its rotation. The X and Y axes are perpendicular to each other, and the plane they form is perpendicular to the Z-axis. The diagram is viewed perpendicular to the paper, so the translation and rotation of the machining head are shown as two-dimensional. However, those skilled in the art will understand that actual machining head translation and rotation are three-dimensional. Furthermore, although this diagram schematically shows only three axes for ease of understanding, those skilled in the art should know that actual multi-axis machine tools are not limited to this.

[0034] like Figure 2 As shown, in the first stage, the machine tool machining head has just finished machining at the current position and is preparing to move to the next machining position. At this time, step 120 is initiated, and the machining head is raised in the Z-axis direction via the machine tool's lifting axis.

[0035] Back Figure 1 Next, in step 140, after the machining head rises to a safe height, the machining head is moved toward the target position in the X-axis and Y-axis directions respectively by the translation axis of the machine tool, and the machining head is rotated toward the target posture by the rotation axis of the machine tool.

[0036] refer to Figure 2 In the second stage, the machining head rises to a safe height driven by the lifting axis. At this height, neither translating the machining head via the translation axis nor rotating it via the rotary axis will cause it to collide with the machining surface. At this point, the machining head is moved towards the target position along the X and Y axes via the translation axis, and rotated towards the target orientation via the rotary axis. It is important to note that in this stage, step 120 continues; that is, the machining head needs to continue rising under the drive of the lifting axis until it reaches H. 旋转启动 (the height required for the machining head to rotate to the target orientation) and H 平移启动 The corresponding height is the larger of the two values: (the height required for the processing head to move to the target position). At this point, the lifting shaft can remain stationary or continue to rise.

[0037] Then, in step 160, after the machining head reaches the descent opening position, the machining head begins to descend in the Z-axis direction via the lifting axis, while step 140 continues until the machining head has moved to the target position in the X, Y and Z-axis directions and rotated to the target posture in the rotation direction.

[0038] Refer again Figure 2 In the third stage, after the machining head reaches the lowering open position, the lifting axis begins to descend, while the translation axis continues to drive the machining head to translate towards the target position, and the rotation axis continues to drive the machining head to rotate towards the target posture. This continues until the fourth stage, when the machining head has moved to its position in the X, Y, and rotational directions, it has also descended to its position in the Z-axis direction.

[0039] The multi-axis machine tool machining head movement method provided by this invention offers a novel technical approach to machining head movement in multi-axis machine tools with rotary axes. It cleverly employs a near-parallel approach to coordinate the movements of the lifting, translational, and rotary axes. Specifically, the translational and rotary axes initiate movement when the machining head reaches a safe height, and the lifting axis initiates descent when the machining head reaches the descent activation position. This significantly reduces the time required in existing technologies where other axial movements must wait until the lifting axis reaches its highest position or until all other axial movements have finished before descent begins, thus shortening the time required for the machining head to reach the target position. Furthermore, this invention fully considers safety. Compared to existing technologies where the lifting axis moves simultaneously with other axes or continuously follows their movement, this invention initiates other axial movements only when the lifting axis raises the machining head to a safe height where collisions are unlikely, and initiates descent only when the machining head reaches the descent activation position. Therefore, collisions are eliminated, ensuring high safety.

[0040] It should be noted that the above embodiments shorten both the waiting time for the translational and rotary axes and the waiting time for the lifting axis. However, the processing head movement method of the present invention can also shorten the waiting time by choosing either one. For example, in the second stage described above, the safety height can be selected as the highest position of the lifting axis. In this way, step 120 is not continued while step 140 is being performed. However, in the third stage described above, the position where the translational and rotary axes have not fully moved into place can be selected as the descent initiation position for the lifting axis to descend. In this way, step 140 needs to continue while step 160 is being performed until the processing head has moved to the target position in the X, Y, and Z axes and rotated to the target posture in the rotational direction. In this way, the waiting time for the lifting axis and the translational and rotary axes can be shortened, thereby shortening the processing head movement time while ensuring safety. For example, in the third stage mentioned above, the position where both the translational and rotary axes have moved into place can be selected as the lowering activation position for initiating the descent of the lifting axis. In this case, step 140 is not continued while step 160 is being performed. However, in the second stage mentioned above, a height lower than the highest position of the lifting axis can be selected as the safety height for initiating the movement of the translational and rotary axes. In this case, step 120 still needs to continue while step 140 is being performed, until the processing head reaches H. 旋转启动 and H 平移启动 The corresponding height of the larger of the two axes. In this way, the waiting time for the translational and rotary axes to reach the lifting axis can be shortened, thereby also shortening the movement time of the machining head while ensuring safety.

[0041] In step 140 above, the safety height may include the translational start height and the rotational start height, i.e., the aforementioned H. 平移启动 and H旋转启动 These correspond to the safe starting heights for translational axis motion and rotational axis motion, respectively.

[0042] Taking a five-axis planar beveling machine as an example, it has a lifting axis (Z1 axis), translation axes (X1 and Y1 axes), and rotary axes (A1 and B1 axes). When the Z1 axis raises the machining head to the translation start height H... 平移启动 Then, the X1 and Y1 axes respectively move the machining head towards the target position P in their respective directions. 目标 Movement. Generally, users are more familiar with the surface of the parts they are machining and are more aware of where there might be bumps or protrusions on the surface, so the starting height H for this translation is... 平移启动 It can be input by the user, or by the operator based on experience, as long as the input H... 平移启动 The movement along the X1 and Y1 axes from the initial height should not result in a collision. This H... 平移启动 The smaller the value, the earlier the movement of the X1 and Y1 axes begins, and the more the machining head movement time can be shortened.

[0043] When the workpiece is very flat, then H 平移启动 It can be 0. When the workpiece is not flat enough, for example, the target position P as shown in Figure 3(a) 目标 Relative to the current position P 当前 There is a certain degree of tilting. If the machining head does not lift up as shown in Figure 3(b) and starts to move directly, it will definitely collide with the workpiece. In this case, H 平移启动 The height (translation collision height) can be selected as shown in Figure 3(c) to ensure that the machining head does not collide with the workpiece. However, in actual operation, since the Z1 axis is still rising after the translation begins, the machining head can also start moving in the X1 and Y1 axis directions before reaching the translation collision height. That is, as shown in Figure 3(d), translation can begin as long as the machining head is raised to a certain height, as long as the machining head has risen to the translation collision height before reaching the collision position. Generally, if a small-range translation movement at a certain height will not result in a collision, then that height can be determined as H. 平移启动 Based on experience, the "small area" here can be, for example, a circle with a radius of 20cm centered on the processing head.

[0044] After the X1 and Y1 axes begin to move, the Z1 axis continues to rise until the machining head reaches the rotary start height H. 旋转启动 Then, the A1 and B1 axes begin to rotate the machining head so that it rotates in the direction of rotation toward the target orientation.

[0045] Because a "collision" (the machining head hitting the machining surface) may occur during the rotation of the machining head, it is necessary to select H.旋转启动 This ensures that rotation of the A1 and B1 axes at this height will prevent the machining head from hitting the plate. Similarly, while ensuring that no collision occurs, this H... 旋转启动 The smaller the value selected, the earlier the rotational motion of the A1 and B1 axes begins, and the greater the reduction in machining head traverse time. This ensures that collisions do not occur. 旋转启动 It can even be less than or equal to H 平移启动 That is, the rotation of the A1 and B1 axes begins before the movement of the X1 and Y1 axes, or the rotation of the A1 and B1 axes begins simultaneously with the movement of the X1 and Y1 axes.

[0046] In this example, H 旋转启动 Still greater than H 平移启动 Therefore, as an alternative, the machining head can also be raised to H. 旋转启动 Then, the X1 and Y1 axes begin to move together with the A1 and B1 axes to drive the machining head toward the target position P. 目标 Moving is also safe. But obviously, choosing H is preferable. 平移启动 By initiating the translational axis movement, the movements of the X1 and Y1 axes can begin earlier and end correspondingly earlier, thus completing the machining head movement in less time. Similarly, if H 旋转启动 Less than H 平移启动 Then it can also rise to H in the processing head. 平移启动 Then, the A1 and B1 axes begin to move together with the X1 and Y1 axes to drive the machining head to rotate toward the target orientation. This is also safe, but similarly, choosing H... 旋转启动 By initiating the movement of the rotary axes, the movement of the A1 and B1 axes can begin earlier and end earlier, thus completing the movement of the machining head in less time.

[0047] Rotary start height H 旋转启动 It can be that the processing head reaches the translation start height H 平移启动 The height reached after further ascent. Optionally, this further ascent height can be the height H required for the machining head to rotate to the target posture. 旋转上抬 . Figures 4(a) to 4(c)The figure illustrates several possible scenarios for the machining head rotating to the target posture: 1) the machining head swings directly downwards (downwards) to the target posture (as shown in Figure 4(a)); 2) the machining head needs to be aligned before swinging upwards (upwards) to the target posture (as shown in Figure 4(b)), where the target posture is the aligned posture; and 3) the machining head swings directly upwards to the target posture (as shown in Figure 4(c)). Similarly, the figure shows a two-dimensional state viewed perpendicular to the plane of the paper. In reality, the translation and rotation of the machining head are three-dimensional. For easier understanding, only three motion axes are schematically shown in the figure, but actual multi-axis machine tools are not limited to this.

[0048] In scenario 1), as shown in Figure 4(a), the height of the machining head relative to the machining surface decreases during its rotation toward the target orientation. Therefore, direct rotation could potentially lead to a collision with the machining surface (collision). It is necessary to raise the machining head a certain distance via a lifting shaft before rotating to avoid this collision. As mentioned earlier, to prevent collisions, the rising distance should be as small as possible, as this will help shorten the machining head's movement time. 旋转上抬 This refers to the minimum upward distance of the machining head to ensure that it will not collide with the target orientation during its rotation.

[0049] Referring to Figure 4(a), assuming the machining head will collide with the plate in its current posture, imagine it slowly rising in the lifting direction while simultaneously rotating its axis to swing towards the target posture, keeping the distance between the machining head and the machining surface constant. When the machining head reaches the target posture, the distance it has risen is H. 旋转上抬 That is, the height difference between the current orientation of the machining head and the height when it reaches the target orientation. Referring to Figure 4(a), this height difference is related to the angle θ1 of the rotation axis in the current orientation relative to its zero position (generally, the coordinates of the rotation axis that puts the machining head in the upright orientation are taken as the zero position) and the angle θ2 of the rotation axis in the target orientation relative to its zero position. In other words, it is related to the angles θ1 and θ2 of the rotation axes in the current and target orientations relative to the Z-axis direction (vertical direction), specifically: L*cosθ2-L*cosθ1, where L is the equivalent length of the rotation axis. It should be noted that, for ease of understanding, the figure shows a two-dimensional state viewed from a direction perpendicular to the paper. The plane in which the angles θ1 and θ2 are located is the same as the paper plane, but those skilled in the art should understand that the actual plane in which the angles θ1 and θ2 are located may be different from the paper plane. Furthermore, the figure only schematically shows one rotation axis. It can be understood that with more than one rotation axis, the length of each rotation axis and the angle between that rotation axis and the Z-axis direction in the current and target attitudes need to be substituted into the above (L*cosθ2-L*cosθ1) for calculation, and the maximum value should be taken as H. 旋转上抬 .

[0050] In case 2), as shown in Figure 4(b), because the machining head first swings down, then straightens, and then swings up during the rotation towards the target orientation, the height of the machining head relative to the machining surface will gradually decrease, reaching its minimum at the straightened orientation, and then gradually increase again (if the target orientation is the straightened orientation, it will not increase). Therefore, to prevent collisions, the machining head needs to be raised a certain distance via the lifting shaft before rotating. At this point, H... 旋转上抬 It should be the minimum height that the machining head needs to continue rising in the Z-axis direction to ensure that it will not collide with the machining surface when it is in a centered position.

[0051] Referring to Figure 4(b), assuming the machining head is about to collide with the plate in its current posture, imagine it slowly rising in the lifting direction while simultaneously rotating the axis to swing it vertically, keeping the distance between the machining head and the machining surface constant. When the machining head reaches the aligned position, the distance it has risen is H. 旋转上抬 That is, the height difference between the current orientation of the machining head and the orientation when it is aligned. As shown in Figure 4(b), this height difference is related to the angle θ between the rotation axis in the current orientation and its zero position (i.e., the Z-axis direction), specifically: LL*cosθ, where L is the equivalent length of the rotation axis. It should also be noted that, for ease of understanding, the figure shows a two-dimensional state viewed from a direction perpendicular to the paper, and the plane where the angle θ is located is the same as the paper plane. However, those skilled in the art should understand that the actual plane where the angle θ is located may be different from the paper plane. In addition, only one rotation axis is schematically shown in the figure. It can be understood that in the case of more than one rotation axis, the length of each rotation axis and the angle between the rotation axis and the Z-axis direction need to be substituted into the above (LL*cosθ) for calculation, and the maximum value is taken as H. 旋转上抬 .

[0052] In case 2), the machining head starts from the translational starting height H. 平移启动 The above H continued to rise (also known as upward movement). 旋转上抬 After that, no matter how the rotating shaft swings, it will not collide with the plate, because the machining head will not collide with the machining surface when it is in the most upright position closest to the machining surface.

[0053] In case 3), as shown in Figure 4(c), since the height of the machining head relative to the machining surface gradually increases during the rotation towards the target orientation, a collision will not occur even if the machining head does not rise in the Z-axis direction. Therefore, H 旋转上抬 It can be 0.

[0054] The machining head starts from a translational height H 平移启动 The aforementioned H continued to rise. 旋转上抬It then begins to rotate toward the target orientation, which is undoubtedly safe, because at this height, even at the lowest position of the processing head, it will not collide with the plate.

[0055] However, in actual operation, it also takes time for the processing head to rotate into position (to the target posture).

[0056] In case 1), the distance between the machining head and the machining surface gradually decreases during the swing from the current posture to the target posture. Therefore, even if the machining head has not fully lifted H when the swing begins, 旋转上抬 At this height, rotation may not necessarily result in a collision with the plate. However, as the machining head gets closer to the target posture and closer to the machining surface, it needs to continue to rise until it reaches the desired rotation position, at which point the machining head needs to be fully raised by H. 旋转上抬 The height must be such that it doesn't hit the board. Therefore, an adjustment coefficient Coeff can be set to make H... 旋转启动 =H 平移启动 +H 旋转上抬 *Coeff, by adjusting this coefficient Coeff within a range less than 1, allows the machining head to move from the translation start height H. 平移启动 It continued to rise by less than H 旋转上抬 The height is then driven by the rotating shaft to begin rotating and swinging, until it is fully raised by H. 旋转上抬 The machining head will either rotate to its final position at the exact moment of rotation or shortly thereafter. In other words, it will rotate the machining head from its initial rotation height H in the Z-axis direction. 旋转启动 Continue to rise H 旋转上抬 The time taken to reach the height of (1-Coeff) is less than or equal to the time taken for the machining head to rotate from its current position to the target position. In this way, while ensuring that there is no collision with the plate, the waiting time for the rotary axis to start can be further reduced, thereby further shortening the time for the machining head to move to the target position.

[0057] Similarly, in case 2), the distance between the machining head and the machining surface gradually decreases during the swing from the current posture to the upright posture. Therefore, even if the machining head is not fully raised at the beginning of the swing, the distance is not significantly different. 旋转上抬 At this height, rotating the machine head may not necessarily cause it to hit the plate. However, as the machining head gets closer to the aligned position and closer to the machining surface, it needs to be raised further until it is fully aligned. At this point, the machining head needs to be raised completely (H). 旋转上抬 The height must be such that it doesn't hit the board. Therefore, H can also be made... 旋转启动 =H 平移启动 +H 旋转上抬 *Coeff and adjust the above coefficient Coeff within a range less than 1, so that the machining head starts from the translational starting height H. 平移启动 It continued to rise by less than H 旋转上抬The height is then driven by the rotating shaft to begin rotating and swinging, until it is fully raised by H. 旋转上抬 It will be perfectly aligned at the exact moment or will be perfectly aligned shortly thereafter. In other words, it means that the machining head is positioned at the starting height H in the Z-axis direction. 旋转启动 Continue to rise H 旋转上抬 The time taken to raise the height of (1-Coeff) is less than or equal to the time taken for the machining head to rotate from its current position to its alignment position. In this way, while ensuring that the machining head does not collide with the plate, the waiting time for the rotary axis to start can be further reduced, thereby further shortening the time for the machining head to move to the target position.

[0058] In actual operation, it is also possible to shift the starting height H. 平移启动 The height is so high that the machining head will not collide with the plate even if it does not rise any further, or, as in case 3) above, the rotation of the machining head will directly swing to the target posture. In this case, the Coeff can be set to 0, that is, H 旋转上抬 *Coeff=0, the machining head reaches the translation start height H 平移启动 Then, the rotation and oscillation of the rotating shaft are started directly.

[0059] In addition, in case 3) above, H can also be selected. 旋转启动 Less than H 平移启动 That is, the machining head rotates towards the target orientation under the drive of the rotary axis before the translational motion begins. For example, the rotation of the rotary axis can even be started simultaneously with the rise of the lifting axis, i.e., H 旋转启动 It can even be 0. In this way, while ensuring safety, the waiting time for the rotary axis to start can be further reduced, thereby further shortening the time for the machining head to move into place.

[0060] Optionally, in step 160 above, the descent start position P is selected. 下降开启 This causes the processing head to descend from the opening position P. 下降开启 Move to the target position P in the X and Y axis directions. 目标 And from the P 下降开启 The remaining time required for the corresponding posture to rotate to the target posture is less than the remaining time required for the lifting axis to descend to its lowest point.

[0061] Here we assume P 下降开启 and P 目标 The coordinates in the X and Y directions are respectively (X 下降开启 Y 下降开启 ) and (X 目标 Y 目标 The machining head's movement from X can be calculated based on its actual movement. 下降开启 Move to X 目标 The required time T X剩余Processing head from Y 下降开启 Move to Y 目标 The required time T Y剩余 And the processing head from the P 下降开启 The time T required for the corresponding attitude to rotate to the target attitude 旋转剩余 Take T X剩余 T Y剩余 And T 旋转剩余 The maximum value is the value of the processing head from P. 下降开启 Move to P in the X and Y axis directions 目标 And from the P 下降开启 The remaining time required for the corresponding attitude to rotate to the target attitude. This remaining time is less than the remaining time T required for the elevator axis to descend to its lowest point. Z剩余 (This can be calculated based on the height difference between the current height of the lifting shaft and its lowest point, as well as the actual movement, etc.), thus ensuring that the movement of the processing head in the X and Y axes and the rotation in the rotation axis are completed before the lifting shaft descends to its lowest point. (This is related to Max(T)) X剩余 ,T Y剩余 ,T 旋转剩余 ) greater than or equal to T Z剩余 Compared to the previous method, this saves more time that would otherwise be spent waiting for the other axes to finish moving after the lifting axis has completed its movement.

[0062] Furthermore, if the machine tool is equipped with a capacitive sensor for achieving following, then the descent start position P can be used. 下降开启 Once the lifting axis enters the following state, the capacitive sensor will continuously adjust the lifting speed of the lifting axis based on the sensed capacitance, ultimately maintaining a constant distance between the machining head and the machining surface. This constant distance is the following height, which can be set according to the height of the target position.

[0063] The following describes a preferred embodiment of the method for controlling the movement of the machining head of a multi-axis machine tool according to the present invention, using a planar five-axis beveling machine as an example.

[0064] The planar five-axis beveling machine is mainly used for cutting parts. The cutting head is equipped with a capacitive sensor at the end, which can be used to achieve height following. As mentioned above, the planar five-axis beveling machine has a lifting axis (Z1 axis), translation axes (X1 axis and Y1 axis), and rotary axes (A1 axis and B1 axis). Figure 5 The timing diagram illustrates the entire process of the cutting head of the five-axis beveling machine tool according to the present invention moving to a new target position, wherein the rotation of the cutting head toward the target posture is a direct downward swing, and the cutting plane is perpendicular to the vertical direction.

[0065] like Figure 5As shown, first, the Z1 axis starts to rise, lifting the cutting head. At this time, the X1 axis, Y1 axis, A1 axis, and B1 axis are all in the idle movement state, that is, they do not move.

[0066] When the cutting head is lifted to the translation start height H 平移启动 , the X1 axis and Y1 axis start to drive the cutting head towards the target position P 目标 . The translation start height H can be input according to past experience or the actual surface unevenness of the part to be cut 平移启动 . At this time, the A1 axis and B1 axis are still in the idle movement state.

[0067] When the cutting head continues to rise by H 旋转上抬 *Coeff(0 < Coeff < 1), the A1 axis and B1 axis start to drive the cutting head to rotate towards the attitude of P 目标 . At this time, the X1 axis, Y1 axis, Z1 axis, A1 axis, and B1 axis are all moving. H 旋转上抬 = Max((L A1 *cosθ A12 -L A1 *cosθ A11 ),(L B1 *cosθ B12 -L B1 *cosθ B11 )), where L A1 and L B1 are the equivalent lengths of the A1 axis and B1 axis respectively, θ A11 and θ B11 are the angles of the A1 axis and B1 axis of the cutting head relative to their zero positions (vertical direction) in the current attitude respectively, θ A12 and θ B12 are the angles of the A1 axis and B1 axis of the cutting head relative to their zero positions (vertical direction) in the target attitude respectively. It is necessary to ensure that the cutting head will not hit the plate when rotating driven by the A1 axis and B1 axis, so it is necessary to calculate (L A1 *cosθ A12 -L A1 *cosθ A11 ) and (L B1 *cosθ B12 -L B1 *cosθ B11 ) and take the larger value. Adjust Coeff so that if the cutting head is to rotate in place (that is, the cutting head rotates from the current attitude to the target attitude), the time it takes is greater than or equal to the time for the cutting head to continue rising from the current height by Max((L A1 *cosθ A12 -L A1 *cosθ A11 ),(L B1 *cosθB12 -L B1 *cosθ B11 The time taken to reach the height of (1-Coeff). When the cutting head moves from H... 平移启动 H was completely raised 旋转上抬 After that, the Z1 axis enters the idle state.

[0068] As the X1 and Y1 axes continue to feed the cutting head to P 目标 The remaining time required for the cutting head to continue rotating to the target posture along the A1 and B1 axes (i.e., determining the remaining time required for each of the four axes to move to the target posture, and taking the maximum value) is less than the time required for the cutting head to descend from the height to the following height along the Z1 axis (here, the lowest height of the cutting head in the lifting axis direction is set as the following height), so that the Z1 axis begins to enter the following state until the cutting head moves to the target posture in all directions.

[0069] It should be noted that although the above description uses a planar five-axis beveling machine tool as an example, those skilled in the art will understand that the method of the present invention for controlling the movement of the machining head of a multi-axis machine tool is also applicable to other multi-axis machine tools with rotary axes.

[0070] This concludes the description of a method for controlling the movement of a machining head in a multi-axis machine tool according to the present invention. The inventors of this invention have pioneered the application of multi-axis parallel idle-movement technology to multi-axis machine tools with rotary axes. While ensuring safety, they employ a near-parallel approach to coordinate the movements of the lifting, translational, and rotary axes. This significantly reduces the time spent in existing multi-axis machine tools where the translational and rotary axes wait for the lifting axis to reach its highest point before starting to move, and wait for the translational and rotary axes to reach their positions before beginning to descend. This greatly shortens the time required for the machining head to reach the target position, thus significantly improving machining efficiency.

[0071] According to embodiments of the present invention, a computer-readable storage medium is also provided, on which encoded instructions are recorded, which, when executed, enable the aforementioned method for controlling the movement of a machining head in a multi-axis machine tool. The computer-readable storage medium may include a hard disk drive, a floppy disk drive, an optical disc read / write (CD-R / W) drive, a digital universal disk (DVD) drive, a flash memory drive, and / or a solid-state storage device, etc. The computer-readable storage medium can be integrated into a multi-axis machine tool or its control system in these forms for controlling the multi-axis machine tool to implement the aforementioned machining head movement method.

[0072] According to embodiments of the present invention, a multi-axis machine tool is also provided accordingly.

[0073] refer to Figure 6The figure shows a schematic block diagram of a multi-axis machine tool 700 according to the present invention. As shown, the multi-axis machine tool 700 includes a machining head 710, a lifting axis 720, a translation axis 730, a rotary axis 740, and a controller 750.

[0074] The lifting shaft 720 is used to lift the machining head 710 in the Z-axis direction, which is the vertical direction.

[0075] The translation axis 730 is used to move the machining head 710 in the X-axis and Y-axis directions. The X-axis and Y-axis are perpendicular to each other and the plane they form is perpendicular to the Z-axis.

[0076] The rotating shaft 740 is used to rotate the machining head 710.

[0077] The controller 750 controls the machining head 710 to move to a target position in a coordinated manner using a lifting axis 720, a translation axis 730, and a rotary axis 740. This includes: controlling the lifting axis 720 to raise the machining head 710 in the Z-axis direction; after the machining head 710 has risen to a safe height, controlling the translation axis 730 to move the machining head 710 towards the target position in the X and Y axes respectively; and controlling the rotary axis 740 to rotate the machining head 710 towards the target orientation, while simultaneously continuing to control the lifting axis 720 to rise or remain stationary. The selection of the safe height allows the translation axis 730 to... During the movement of the rotation axis 740, the machining head 710 will not collide; and after the machining head 710 reaches the lowering open position, the lifting axis 720 is controlled to make the machining head 710 begin to descend in the Z-axis direction, while the translation axis 730 is continued to move the machining head 710 toward the target position and the rotation axis 740 is controlled to make the machining head 710 rotate toward the target posture, or the translation axis 730 and the rotation axis 740 are controlled to remain stationary until the machining head 710 has moved to the target position in the X-axis, Y-axis and Z-axis directions and rotated to the target posture in the rotation direction.

[0078] Optionally, the safety height may include a translational start height and a rotational start height. Alternatively, after the machining head 710 reaches the translational start height, the controller 750 controls the translational axis 730 to move the machining head 710 towards the target position in the X and Y axes, respectively. And when the machining head 710 reaches the rotational start height, the controller 750 controls the rotational axis 740 to rotate the machining head 710 towards the target orientation. Alternatively, after the machining head 710 reaches the greater of the rotational start height and the translational start height, the controller 750 simultaneously controls the translational axis 730 to move the machining head 710 towards the target position in the X and Y axes, respectively, and controls the rotational axis 740 to rotate the machining head 710 towards the target orientation.

[0079] Optionally, the rotation start height H旋转启动 =H 平移启动 +H 旋转上抬 *Coeff, where H 平移启动 H is the translation start height. 旋转上抬 Coeff is the upward lift required for the processing head 710 to rotate to the target posture, where 0 ≤ Coeff ≤ 1.

[0080] Optionally, the adjustment coefficient Coeff is set such that the machining head 710 is positioned in the Z-axis direction from the rotational start height H. 旋转启动 Continue to rise H 旋转上抬 The time taken to reach the height of *(1-Coeff) is less than or equal to the time taken for the rotation axis 740 to rotate from the current posture to the target posture.

[0081] Optionally, the adjustment coefficient Coeff is set such that the machining head 710 is positioned in the Z-axis direction from the rotational start height H. 旋转启动 Continue to rise H 旋转上抬 The time taken to raise the height of *(1-Coeff) is less than or equal to the time taken to rotate the rotation axis 740 from the current attitude to the correct attitude.

[0082] Optionally, the remaining time required for the processing head 710 to move from the lowering open position to the target position in the X and Y axis directions and to rotate from the posture corresponding to the lowering open position to the target posture is less than the remaining time required for the lifting shaft 720 to descend to its lowest point.

[0083] The multi-axis machine tool 700 described above can realize the method for controlling the movement of the machining head of the multi-axis machine tool according to the present invention, as described above. Many of the design concepts and details applicable to the method for controlling the movement of the machining head of the multi-axis machine tool described above are also applicable to the device 700 described above, and the same beneficial technical effects can be obtained, which will not be repeated here.

[0084] The various aspects of the present invention have been described above through exemplary embodiments. However, it should be understood that various modifications can be made to the above exemplary embodiments without departing from the spirit and scope of the invention. For example, if suitable results can be achieved if the described techniques are performed in a different order and / or if components in the described system, architecture, device, or circuit are combined in different ways and / or replaced or supplemented by other components or their equivalents, then correspondingly, these modified other embodiments also fall within the scope of protection of the claims.

Claims

1. A method for controlling the movement of a machining head on a multi-axis machine tool, comprising the following steps: a) The machining head is raised in the Z-axis direction via the lifting axis of the machine tool, where the Z-axis direction is vertical; b) After the machining head rises to a safe height, it is moved towards the target position along the X-axis and Y-axis respectively via the translational axis of the machine tool, and rotated towards the target orientation via the rotary axis of the machine tool. The X-axis and Y-axis are perpendicular to each other, and the plane they form is perpendicular to the Z-axis. The safe height is chosen such that the machining head will not collide during the movement of the translational and rotary axes. c) After the machining head reaches the descent open position, the machining head is lowered along the Z-axis by the lifting axis until the machining head has moved to the target position in the X, Y, and Z axes and rotated to the target posture in the rotational direction. in, Step a) continues while step b) is being performed, and step b) continues while step c) is being performed, wherein the safety height includes the translation start height H. 平移启动 and rotation start height H 旋转启动 , When the processing head reaches the translation start height H 平移启动 Then, the translational axis causes the machining head to begin moving towards the target position in the X and Y axes, respectively, and when the machining head reaches the rotation start height H... 旋转启动 Then, the rotating axis causes the processing head to begin rotating toward the target orientation; or When the processing head reaches the rotary start height H 旋转启动 and the translation start height H 平移启动 After reaching a height of a larger value, the translational axis causes the machining head to begin moving towards the target position in the X and Y axes respectively, while the rotational axis causes the machining head to begin rotating towards the target orientation, wherein the rotation start height H... 旋转启动 =H 平移启动 +H 旋转上抬 Coeff, where H 平移启动 H is the translation start height. 旋转上抬 Coeff is the upward lift required for the processing head to rotate to the target posture, where 0 ≤ Coeff ≤ 1.

2. The method as described in claim 1, characterized in that, The adjustment coefficient Coeff is set such that the machining head starts from the rotational height H in the Z-axis direction. 旋转启动 Continue to rise H 旋转上抬 The time taken to raise (1-Coeff) is less than or equal to the time taken for the processing head to rotate from the current posture to the target posture.

3. The method as described in claim 1, characterized in that, The adjustment coefficient Coeff is set such that the machining head starts from the rotational height H in the Z-axis direction. 旋转启动 Continue to rise H 旋转上抬 The time taken to raise (1-Coeff) is less than or equal to the time taken for the processing head to rotate from its current position to its upright position.

4. The method as described in claim 1, characterized in that, The remaining time required for the processing head to move from the lowering open position to the target position in the X and Y axis directions and to rotate from the posture corresponding to the lowering open position to the target posture is less than the remaining time required for the lifting shaft to descend to its lowest point.

5. A multi-axis machine tool, comprising: Processing head; A lifting axis is used to lift the machining head in the Z-axis direction, which is the vertical direction; Translation axis, used to move the machining head in the X-axis and Y-axis directions, the X-axis and Y-axis are perpendicular to each other and the plane they form is perpendicular to the Z-axis; A rotating shaft is used to rotate the processing head; as well as A controller is used to control the processing head to move to a target position in a manner in which the lifting axis, translation axis, and rotation axis cooperate with each other, including: Control the lifting axis to raise the machining head in the Z-axis direction; After the machining head rises to a safe height, the translational axis is controlled to move the machining head towards the target position in the X and Y axes respectively, and the rotational axis is controlled to rotate the machining head towards the target posture. Simultaneously, the lifting axis continues to rise. The safe height is selected to prevent the machining head from colliding during the movement of the translational and rotational axes. After the machining head reaches the descent start position, the lifting axis is controlled to cause the machining head to begin descending in the Z-axis direction. Simultaneously, the translation axis is controlled to move the machining head to the target position, and the rotation axis is controlled to rotate the machining head towards the target posture, until the machining head has moved to the target position in the X, Y, and Z-axis directions and rotated to the target posture in the rotational direction. The safety height includes the translation start height H. 平移启动 and rotation start height H 旋转启动 , When the processing head reaches the translation start height H 平移启动 Then, the controller controls the translation axis to cause the machining head to begin moving towards the target position in the X and Y axes respectively, and when the machining head reaches the rotation start height H... 旋转启动 Then, the controller controls the rotating axis to cause the processing head to begin rotating toward the target orientation; or When the processing head reaches the rotary start height H 旋转启动 and the translation start height H 平移启动 After reaching a height of a larger value, the controller simultaneously controls the translation axis to move the machining head towards the target position in the X and Y axes respectively, and controls the rotation axis to rotate the machining head towards the target orientation. The rotation start height H... 旋转启动 =H 平移启动 + H 旋转上抬 H 平移启动 H is the translation start height. 旋转上抬 Coeff is the upward lift required for the processing head to rotate to the target posture, where 0 ≤ Coeff ≤ 1.

6. The multi-axis machine tool as described in claim 5, characterized in that, The adjustment coefficient Coeff is set such that the machining head is at the rotational start height H in the Z-axis direction. 旋转启动 Continue to rise H 旋转上抬 The time taken to raise (1-Coeff) is less than or equal to the time taken for the processing head to rotate from the current posture to the target posture.

7. The multi-axis machine tool as described in claim 5, characterized in that, The adjustment coefficient Coeff is set such that the machining head is at the rotational start height H in the Z-axis direction. 旋转启动 Continue to rise H 旋转上抬 The time taken to raise (1-Coeff) is less than or equal to the time taken for the processing head to rotate from its current position to its upright position.

8. The multi-axis machine tool as described in claim 5, characterized in that, The remaining time required for the processing head to move from the lowering open position to the target position in the X and Y axis directions and to rotate from the posture corresponding to the lowering open position to the target posture is less than the remaining time required for the lifting shaft to descend to its lowest point.

9. A computer-readable storage medium having encoded instructions recorded thereon, which, when executed, implement the method as described in any one of claims 1 to 4.

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