阅读说明：本技术 滑架同步 (Carriage synchronization ) 是由 M·艾维 E·柯林斯 D·D·丹尼尔斯 于 2017-04-21 设计创作，主要内容包括：一种示例性三维打印系统包括第一滑架、第二滑架和同步控制器。该同步控制器被耦接到第一滑架和第二滑架,以使第一滑架和第二滑架的移动同步。该同步控制器避免第一滑架和第二滑架之间的干扰。(An exemplary three-dimensional printing system includes a first carriage, a second carriage, and a synchronization controller. The synchronization controller is coupled to the first and second carriages to synchronize movement of the first and second carriages. The synchronization controller avoids interference between the first carriage and the second carriage.)

1. A three-dimensional printing system, comprising:

a first carriage;

A second carriage; and

A synchronization controller coupled to the first and second carriages to synchronize movement of the first and second carriages and avoid interference between the first and second carriages.

2. The three-dimensional printing system of claim 1,

wherein the first carriage transports build material to a staging area; and

The second carriage dispenses the build material on a build area and fuses the build material.

3. The three-dimensional printing system of claim 2, further comprising:

A third carriage that applies reagent to the build material on the build area,

wherein the synchronization controller is further coupled to the third carriage and synchronizes the movement of the first, second and third carriages and avoids interference between different ones of the carriages.

4. The three-dimensional printing system of claim 1, wherein to synchronize the movement of the first carriage and the second carriage, the synchronization controller determines that the time the second carriage exits the impact region is less than the time the first carriage enters the impact region.

5. The three-dimensional printing system according to claim 4, wherein to avoid interference between the first carriage and the second carriage, the synchronization controller stops the second carriage if the second carriage passes a trigger position while the first carriage is in a collision region.

6. The three-dimensional printing system of claim 1, wherein to synchronize the movement of the first carriage and the second carriage, the synchronization controller calculates and maintains at least a minimum spacing between the first carriage and the second carriage based on current position measurements.

7. The three-dimensional printing system of claim 6, wherein to avoid interference between the first carriage and the second carriage, the synchronization controller predicts future positions of the first carriage and the second carriage based on a plurality of position measurements.

8. a method, comprising:

Determining that a first carriage is in a collision zone;

determining whether a first time for the first carriage to exit the impact region is less than a second time for a second carriage to enter the impact region; and

Initiating movement of the second carriage if the first time is less than the second time; otherwise

Delaying movement of the second carriage if the first time is not less than the second time.

9. The method of claim 8, further comprising:

Measuring the position of the first and second carriages;

determining whether the second carriage has reached a trigger point outside the impact region when the first carriage is within the impact region; and

stopping movement of said second carriage if said second carriage has reached said trigger point outside said impact area when said first carriage is within said impact area.

10. the method of claim 8, further comprising:

Determining whether a distance between the first carriage and the second carriage is less than a minimum distance to safely stop the carriage; and

if the distance between the first and second carriages is less than the minimum distance, then starting to move a third carriage to a safety position.

11. a non-transitory computer-readable storage medium encoded with instructions executable by a processor of a computing system, the computer-readable storage medium comprising instructions to:

the movements of the first and second carriages are synchronized,

avoiding interference between the first carriage and the second carriage;

synchronizing the movement of the second and third carriages; and

Avoiding interference between the second and third carriages.

12. The non-transitory computer-readable storage medium of claim 11, wherein to synchronize movement of the first carriage and the second carriage, the non-transitory machine-readable storage medium further comprises instructions to:

Determining that the first carriage is in a collision zone;

determining whether a first time for the first carriage to exit the impact region is less than a second time for the second carriage to enter the impact region; and if the first time is less than the second time,

Starting the movement of the second carriage; otherwise, if the first time is not less than the second time,

The movement of the second carriage is delayed.

13. The non-transitory computer-readable storage medium of claim 12, wherein to avoid interference between the first carriage and the second carriage, the non-transitory machine-readable storage medium further comprises instructions to:

Measuring the position of the first and second carriages;

Determining whether the second carriage has reached a trigger point outside the impact region when the first carriage is within the impact region; and if said second carriage has reached said trigger point outside said impact area when said first carriage is within said impact area,

Stopping the movement of the second carriage; otherwise

Continuing the movement of the second carriage.

14. The non-transitory computer-readable storage medium of claim 11, wherein to synchronize movement of the second carriage and the third carriage, the non-transitory machine-readable storage medium further comprises instructions to:

Determining whether a distance between the second and third carriages is less than a minimum distance to safely stop the carriages; and if said distance between said second and third carriages is smaller than said minimum distance,

moving the third carriage towards a safety position; otherwise

Continuing to monitor the distance between the second and third carriages.

15. the non-transitory computer-readable storage medium of claim 14, wherein to avoid interference between the first carriage and the second carriage, the non-transitory machine-readable storage medium further comprises instructions to:

determining whether the third carriage is moving towards the safety position; and if the third carriage is not moved towards the safety position,

stopping the second and third carriages; otherwise

Continuing to move the third carriage toward the safety position.

Background

Three-dimensional (3D) printers typically operate with a carriage that performs various tasks. For example, one carriage may deposit material in layers and the other carriage may apply energy to selectively fuse the material.

Drawings

For a more complete understanding of the various examples, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

FIG. 1 illustrates a block diagram of an exemplary system employing printer carriage synchronization;

FIG. 2 illustrates a block diagram of another exemplary system that employs printer carriage synchronization;

FIG. 3 illustrates a block diagram of an exemplary system having a computer-readable storage medium including instructions executable by a processor for printer carriage synchronization;

FIG. 4 is a flow chart illustrating an exemplary process for printer carriage synchronization;

FIG. 5 is a diagram of an exemplary process for printer carriage synchronization performed by a processor;

FIG. 6 is a flow chart illustrating an exemplary process for printer carriage synchronization performed by a processor; and

FIG. 7 is a detailed flow diagram illustrating additional portions of the exemplary process of FIG. 4.

Detailed Description

various examples described herein provide printer carriage synchronization in a multi-carriage 3D printer to increase printing speed and avoid catastrophic collisions. Various examples include a system having: a first carriage that delivers build material to a staging zone; a second carriage that dispenses build material on a build area; and a third carriage that applies reagent to the build material on the build area. In some examples, a synchronization controller may be coupled to the first, second, and third carriages directly or indirectly (e.g., through a carriage drive system) to synchronize their movements in order to increase speed and avoid high speed collisions that may damage the 3D printer.

In one example, the movements of the second and third carriages are coaxial in a common plane, and the movement of the first carriage is in the same plane and perpendicular to the movements of the second and third carriages.

For simplicity and illustrative purposes, the present disclosure is described by referring mainly to examples thereof. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. It will be apparent, however, that the present disclosure may be practiced without limitation to these specific details. In other instances, some methods and structures have not been described in detail so as not to unnecessarily obscure the present disclosure. As used herein, the terms "a," "an," and "one" are intended to mean at least one of a particular element, the term "including" is intended to include, but is not limited to, the term "comprising" is intended to include, but is not limited to, and the term "based on" is intended to be based, at least in part, on.

referring now to the drawings, FIG. 1 illustrates a block diagram of an exemplary system that employs printer carriage synchronization. In the example of fig. 1, the exemplary three-dimensional printing system 10 includes a first carriage 20 and a second carriage 30. As described in more detail below, various examples of three-dimensional printing systems, such as the exemplary three-dimensional printing system 10 of fig. 1, may include a carriage to perform various functions of 3D printing. For example, the first and second carriages 20, 30 may perform various functions, such as delivering build material to a staging area, spreading the build material over a build area, fusing the build material, or applying an agent to the build material on the build area.

the exemplary three-dimensional printing system 10 of fig. 1 also includes a synchronization controller 40. The synchronization controller 40 is coupled to the first carriage 20 and the second carriage 30. In this regard, the synchronization controller 40 may control or coordinate the movement of the first and second carriages 20, 30. In various examples, the synchronization controller 40 is configured to synchronize the movement of the first and second carriages 20, 30 and avoid interference between the first and second carriages 20, 30. Various examples of the synchronization controller 40 are described below with reference to various figures.

Referring now to FIG. 2, a block diagram of an exemplary system 100 employing printer carriage synchronization is illustrated. The exemplary system includes a first carriage 101, also referred to herein as a belt carriage 101, that operates to transport "build material" to a staging area 102. In one example, the build material may be a powdered thermoplastic or any other material suitable for hot melt. In operation, the tape carriage 101 may be connected to a source of build material (not shown) and may deposit a strip of build material onto the staging area 102 in a sufficient amount to dispense on the print bed 103 at a predetermined thickness, as described below. As indicated by the directional arrow 101a, the movement of the belt carriage 101 is limited to passing through the staging area 102 in two directions. In one example, the belt carriage 101 may pass through the staging area 102 in a single pass, depositing build material in the staging area 102, and then, reside at a location away from a "collision area" 104, the collision area 104 being defined by an area of a second carriage 105, also referred to herein as a fusing carriage 105. The impact area 104 is so called because the belt carriage 101 and the fusing carriage 105 should not be in the impact area 104 at the same time. In one example, the belt carriage 101 may pass through the staging area 102, depositing build material in the staging area 102, and then return to its starting position exiting the collision area 103.

in one example, after build material has been deposited and the belt carriage 101 has left the impact region 103, the fusing carriage 104 moves from its initial position over the staging area 102 and over the print bed 103 while depositing build material on the print bed 103 at some predetermined thickness suitable for the 3D print layer. The fuser carriage 105 can include a spreading device, such as a doctor blade or roller (not shown), to spread the build material over the print bed 103. The spreading device may be adjustable to control the thickness of the build material. Fusing carriage 105 may also include one or more energy sources (not shown), such as heat lamps, having a controllable intensity capable of heating and fusing the build material.

in one example, the fusing carriage 105 may make several passes over the print bed 103 as part of the print bed preparation process, applying energy to preheat the build material to the appropriate temperature for the printing operation. The movement of the fusing carriage 105 is limited to linear movement perpendicular to the movement of the belt carriage 101, as indicated by directional arrow 105 a.

Also included in fig. 2 is a third carriage 106, also referred to herein as a print carriage 106. The movement of the print carriage is limited to a linear movement perpendicular to the movement of the tape carriage 101 and coaxial with the movement of the fusing carriage 105, as indicated by directional arrow 106 a. In various examples, print carriage 106 can include a plurality of nozzles (not shown) that can deliver ink and reagents to the build material to achieve desired characteristics in the printed object. In various examples, the ink may be used to impart color and/or increase energy absorption to the build material. The print carriage can apply a variety of agents, such as fusing agents, fine agents, and agents that control physical properties such as: surface properties, translucency, strength and rigidity, thermal or electrical conductivity, and elasticity of the final printed part, etc. The details of these inks and reagents are beyond the scope of this disclosure and, therefore, are not described in detail herein.

in various examples, the movement of the belt carriage 101, the fuser carriage 105, and the print carriage 106 is controlled by a synchronization controller 107, the synchronization controller 107 operating through a servo-controlled drive system (not shown in fig. 2) to independently control the movement of the three carriages. In some examples, these drive systems may be shaft drive or belt drive systems. The synchronization controller 107 may be any type of suitable computing device, such as a general purpose processor, a microcontroller, dedicated logic, and the like. In various examples, the position of the carriage may be determined by a position encoder (not shown in fig. 2). These position encoders may be any type of encoder suitable for the respective drive mechanism and physical environment. For example, the position encoders may be rotary or linear, absolute or incremental, and the encoding methods may be optical, conductive, magnetic, inductive, capacitive, etc.

As described above, after the print bed 103 is prepared, the printing process may be started. For the sake of clarity, the basic printing process is first described in a series of operations, regardless of the specific timing of operations related to synchronization or collision avoidance, which will be described in detail later. In one example (referring to fig. 2), the fuser carriage 105 moves to the far right of the print bed 103, adjacent to the print carriage 106. Next, the fusing carriage 105 and print carriage 106 pass through the print bed 103 from right to left in close proximity across the print bed 103 while the fusing carriage 105 applies energy to the build material to maintain its proper temperature for reaction with the ink and reagents applied to the build material by the print carriage 106 ("print pass-through").

in this example, the fusing carriage 105 may move into and through the staging area 102 so the print carriage 106 may apply its ink and reagents to the entire print bed 103. Next, the print carriage 106 and the fusing carriage 105 are moved back across the print bed 103 while the fusing carriage applies fusing energy to the build material ("fuse-thru"). In one example, the print carriage 106 may apply additional ink and reagent prior to fusing the carriage 105 as they move together across the print bed 103. As the fusing carriage 105 moves across the impact region 104 as it begins its fusing operation, the synchronization controller 107 monitors its position and moves the belt carriage 101 into the staging area 102 just as the fusing carriage 105 leaves the impact region 104. The tape carriage 101 then passes through the staging area 102 to deposit another band of build material before returning to its starting position ("deposit pass-through").

Continuing with this exemplary printing process, after the print carriage 106 and the fusing carriage 105 have completed their fused traversal of the print bed 103, the print carriage 106 remains stopped at the far right (see fig. 2), exiting the print bed 103. Fusing carriage 105 then returns to its starting position at the far left in FIG. 2. In one example, the fusing carriage 105 may apply additional heating or fusing energy to the build material during its return to the starting position. In this example, the spreader device in the fusing carriage 105 is retracted while the fusing carriage 105 is passing through the staging area 102, effectively "riding over" the strip of build material. Once the fusing carriage 105 leaves the staging area 102, the spreader is returned to its spreading position while the print bed 103 is lowered to make room for the next layer of build material ("bed descent"). After the print bed 103 is lowered to its new position, the fusing carriage 105 traverses from left to right (in FIG. 2) through the staging area 102 and print bed, thereby spreading and preheating build material in a new layer ("spread-through"). This sequence of operations including "print-through", "fuse-through", "deposit-through", "bed-down", and "dispense-through" is repeated until the printed portion is completed.

referring now to fig. 3, a block diagram of an exemplary system having a non-transitory computer-readable storage medium including instructions executable by a processor for printer carriage synchronization is illustrated. The exemplary system 200 includes a processor 205 coupled to a non-volatile computer-readable storage medium 210 and a data store 215. The non-transitory computer readable storage medium 202 includes exemplary instructions 220, 225, 230, and 235 that can be executed by the processor 205 to perform various functions described herein. The data store 215 may contain data files corresponding to the build of the 3D printed portion.

in various examples, the non-transitory computer-readable storage medium 210 and the data store 215 may be any of a variety of storage devices, including but not limited to Random Access Memory (RAM), dynamic RAM (dram), static RAM (sram), flash memory, read-only memory (ROM), programmable ROM (prom), electrically erasable prom (eeprom), and the like. In various examples, processor 205 may be a general purpose processor, dedicated logic, or the like.

The system 200 may also include a tape carriage driver 240 and tape carriage position encoder 245 associated with the tape carriage 101, a fusing carriage driver 250 and fusing carriage position encoder 255 associated with the fusing carriage 105, and a print carriage driver 260 and print carriage position encoder 265 associated with the print carriage 106, all coupled to and controlled by the processor 205. In various examples, the position encoders 245, 255, and 265 may be high-speed four-state encoders capable of taking hundreds of measurements per second that the processor may use to determine position, velocity, and acceleration in real time.

As described above, the exemplary 3D printing process uses coordination between the movement of the tape carriage 101, the fuser carriage 105, and the print carriage 106. In various examples, in order to perform printing at high speed without collision between carriages, a processor performs: instructions 220 for synchronizing movement of the belt carriages; instructions 225 for avoiding interference between the belt carriage and the fusing carriage; instructions 230 for synchronizing movement of the fusing carriage and the print carriage; and instructions 235 for avoiding interference between the fusing carriage and the print carriage.

In some examples, as described above, the belt carriage 101 and the fusing carriage 105 may be near the impact region 104 during various operations. In some examples, the processor 205 performs: instructions 220 to perform operations to synchronize movement of belt carriage 101 and fusing carriage 105 during normal operation; and instructions 225 to avoid interference between belt carriage 101 and fusing carriage 105 under abnormal or anomalous conditions.

Fig. 4 is a flow diagram illustrating an exemplary process 300 performed by processor 205 through execution of instructions 220 and 225. The process begins at operation 302, under instruction 220, when movement of the fusing carriage is initiated. At operation 304, the processor continues to move the fusing carriage 101 and monitors the position of the fusing carriage 105 using the fusing carriage position encoder 255 (position encoder 255). The processor then determines whether the fuser carriage 101 is in the impact region 102 at operation 306. If the fusing carriage is not in the impact area 102, the process loops back to operation 304. If the fusing carriage is in the impact zone, the processor performs calculations based on its readings from the position encoder 255 and the known dynamics of the belt carriage 101 and its drive system 240 at operation 308. In one example, readings from position encoder 255 may be used to determine the velocity of fusing carriage 105 and predict when it will exit impact zone 102. Data of the dynamics of the tape carriage 101 and its drive system 240 may reside in the data store 215 as calibration data with respect to the acceleration and slew rate of the tape carriage 101. In operation 308, the processor determines whether the time that the fusing carriage 105 leaves the impact region 102 is less than the time that the belt carriage 101 enters the impact region 102. If the determination at operation 308 is negative, the movement of the belt carriage 101 is delayed and the process returns to operation 304 where the movement of the fusing carriage 105 continues. If the determination at operation 308 is yes, the processor initiates movement of the belt carriage 101 at operation 310 such that the belt carriage 101 enters the impact region 102 just after the fusing carriage 105 exits the impact region 102.

This exemplary process is graphically illustrated in FIG. 5, where the trajectory of the trailing edge of the fusing carriage 105 through the impact region 102 is plotted as line 401. The slope of line 401 represents the velocity of the fusing carriage 105 and may be calculated by the processor 205 using data from the position encoder 255, as described above. The position and trajectory of the belt carriage 101 is represented by curve 402. It will be apparent from FIG. 5 that the movement of the belt carriage 101 begins after time t0 to avoid colliding with the fusing carriage 105 before t 1.

the instructions 220 for performing operations 302-310 handle normal or intended functions of the tape carriage 101 and the fusion carriage 105. However, if the fusing carriage 105 fails to act as commanded by the processor 205, additional operations may be used to avoid a collision between the belt carriage 101 and the fusing carriage 105. In one example, the fusing carriage driver 250 may fail while the fusing carriage 105 is still in the impact region 102. Instruction 225 resolves such exception condition.

returning now to FIG. 4, under instruction 225, process 300 continues at operation 312, where processor 205 continuously measures the position of belt carriage 101 and fusing carriage 105 by reading their respective position encoders 245 and 255. At operation 314, the processor 205 determines, based on the speed of the tape carriage 101 and the dynamics of its drive system, whether the tape carriage 101 has reached a "trigger point," which is defined as the point: if this point is exceeded, the belt carriage 101 cannot be held outside the impact region 102. If the determination is negative, the process returns to operation 312 where the position of the belt carriage 101 and the fusing carriage 102 are continuously measured. If so, the process continues at operation 316, where the processor 105 determines whether the fusing carriage 105 has left the impact zone by reading the position encoder 255 of the fusing carriage 105. If the determination is yes, the movement of the belt carriage into the impact region 102 is completed at operation 318. If the determination is negative, the tape carriage is stopped without reaching the impact region in operation 320 when the error handling mechanism may be invoked.

in some examples, as described above, during various operations (e.g., during a print pass and a fuse pass as previously described), the print carriage 106 and the fuse carriage 105 may be in close proximity, or the fuse carriage 105 may be moving toward the stationary print carriage 106 (e.g., during a bed preparation or a dispense pass as previously described). In various examples, the processor 205 performs: instructions 230 to perform operations to synchronize movement of the print carriage 106 and the fusing carriage 105 during normal operation; and instructions 235 to avoid interference between the print carriage 106 and the fuse carriage 105 under abnormal or anomalous conditions.

fig. 6 is a flow diagram illustrating an exemplary process 400 performed by processor 205 through execution of instructions 230 and 235. The process begins at operation 402, under instruction 230, when movement of the fusing carriage is initiated. At operation 404, the processor continues to move the fusing carriage 105 and monitors the position of the fusing carriage 105 by reading the fusing carriage position encoder 255 (position encoder 255). At operation 406, the processor measures the position of the print carriage 106 by reading the print carriage position encoder 265 (position encoder 265) and determines whether the distance between the fuser carriage 105 and the print carriage 106 is less than a threshold distance, where the threshold distance is the distance that gives time for the print carriage to move to a safe position. In one example, the secure position may be a designated service area or parking area reserved for the print carriage.

if the determination is negative, the process returns to operation 404 and the movement of the fusing carriage continues. If so, the processor performs operation 408 to move the print carriage to a safe position.

the instructions 230 for performing operations 402-408 process the normal or intended function of the print carriage 106 and the fusion carriage 105. However, if the print carriage 106 or the fuser carriage 105 fails to act as commanded by the processor 205, additional operations may be used to avoid a collision between the print carriage 106 and the fuser carriage 105. Instruction 235 resolves such exception condition.

Returning now to FIG. 6, under instruction 235, the process 400 continues at operation 410, where the processor 205 continuously measures the positions of the print carriage 106 and the fuser carriage 105 by reading their respective position encoders 265 and 255. At operation 412, the processor 205 determines whether the distance between the fuser carriage 105 and the print carriage 106 is less than a minimum distance for a safety stop. Such a condition may occur, for example, if the printer carriage stops moving during traversal of the print bed 103. If the determination is negative, the process loops back to operation 410 where the position of the carriage is continuously monitored. If so, the processor executes operation 414 to initiate movement of the print carriage 106 toward the safe position. At operation 416, the processor determines whether the print carriage has begun movement to a safe position. If the determination is yes, the move is completed by the processor at operation 418. If the determination is negative, the processor stops all carriage movement at operation 420 when other error handling actions may be invoked.

Referring now to FIG. 7, a flow chart illustrates an exemplary method 500 for printer carriage synchronization. The example method 500 may be implemented in a number of ways, such as in the synchronization controller 107 in the example system 100 of FIG. 2 or in the processor 205 in the example system 200 of FIG. 3.

The example method 500 may include operations for synchronizing movement of the belt carriage 101 and the fusing carriage 105 (block 502), as previously described with respect to the example system 200 of fig. 3 and the operation 302 and 310 of the example process 300 of fig. 4. The example method 500 may also include operations for avoiding interference between the belt carriage 101 and the fusing carriage 105 (block 504), as previously described with respect to the example system 200 of FIG. 3 and the operations 312 and 320 of the example process 300 of FIG. 4.

The example method 500 may also include operations for synchronizing movement of the print carriage 106 and the fusing carriage 105 (block 506), as previously described with respect to the example system 200 of FIG. 3 and the operation 402 of the example process 400 of FIG. 6. The example method 500 may also include operations for avoiding interference between the print carriage 106 and the fusing carriage 105 (block 508), as previously described with respect to the example system 200 of fig. 3 and the operations 410 and 420 of the example process 400 of fig. 6.

the foregoing description of various examples has been presented for the purposes of illustration and description. The foregoing description is not intended to be exhaustive or to be limited to the disclosed examples, and modifications and variations are possible in light of the above teachings or may be acquired from practice of various examples. The examples discussed herein were chosen and described in order to explain the principles and the nature of various examples of the present disclosure and its practical application to enable one skilled in the art to utilize the present disclosure in various examples and with various modifications as are suited to the particular use contemplated. The features of the examples described herein may be combined in all possible combinations of methods, apparatus, modules, systems, and computer program products.

It is also noted herein that while the above describes examples, these descriptions should not be viewed in a limiting sense. Rather, there are numerous variations and modifications which may be made without departing from the scope as defined in the appended claims.