TWI578123B - Detection and repairing device of additive manufacturing technology and method thereof - Google Patents

Description

Detection repairing device for powder laminate manufacturing and method thereof

The present invention relates to a detecting and repairing apparatus and method thereof, and more particularly to a detecting and repairing apparatus for powdered layer manufacturing and a method thereof.

Additive Manufacturing (AM) technology, also known as additive manufacturing, is a method of layer-by-layer stacking by extracting multiple 2D slice profiles from a 3D model and layering them according to each 2D slice profile. Machining a workpiece.

At present, the laminated manufacturing technology mainly focuses on the laser laminate manufacturing technology, and uses a laser melting method to deposit a powder layer with a powder coating mechanism according to a plurality of two-dimensional layer profiles of the three-dimensional model, and then the laser beam. Focusing on the powder layer, followed by melt forming a two-dimensional slice profile and stacking the workpiece layer by layer.

In the laminated manufacturing process, the quality of the workpiece is affected by factors such as the power of the laser, the flow field of the gas, and the quality of the powder, resulting in defects in the powder layer, such as poor powdering, warpage of the workpiece, and workpiece The surface forms protrusions or depressions and the like. However, the current equipment for laser laminate manufacturing technology lacks a mechanism for correcting the above defects, so that the yield of the workpiece and the quality of the workpiece cannot be effectively improved.

Therefore, it is necessary to provide an improved detection and repair device for powder lamination manufacturing. And its methods to solve the problems of conventional technology.

One of the main objects of the present invention is to provide a method for detecting and repairing powdered layer manufacturing, which can effectively judge various defects and improve the quality of the workpiece by detecting the image data after the powdering and the image data after melting.

Another object of the present invention is to provide a detection and repairing device for powder lamination manufacturing, which can increase the yield of a workpiece by detecting the powder bed platform by the camera and repairing the workpiece by the repairing unit.

In order to achieve the above object, the present invention provides a method for detecting and repairing a powder laminated layer for detecting and repairing a workpiece manufactured by lamination, the detecting and repairing method comprising a powder laying step, a melting step, a melting detecting step and a melting repairing step; wherein the powdering step is to use a powder laying mechanism to lay a powder on a powder bed platform; the melting step is a powder that is melted and laid on the powder bed platform by a laser; the melting detecting step Using a camera to capture a molten image data of the powder bed platform, and transmitting it to the controller for detection; in the melting repair step, the controller determines whether to drive a processing according to a detection result of the molten image data. The mechanism repairs a surface of the workpiece.

In an embodiment of the invention, the melting detecting step has a bump detecting sub-step for detecting a raised area of the molten image data, and calculating a position and a size of the raised area.

In an embodiment of the invention, a brightness of the raised area is greater than 110% of an average brightness of the contour region of the layer of the melted image data.

In an embodiment of the invention, the melting detecting step further has a raised area The processing path substep, after the bump detecting substep, calculates a bump processing path according to a planned processing path and the position and size of the raised area.

In an embodiment of the invention, in the smelting repair step, a plurality of knives of the processing mechanism are used to machine the surface of the workpiece in accordance with the processing path of the raised portion.

In an embodiment of the invention, the melting detecting step has a recessed area detecting sub-step of detecting the recessed area of the molten image data, and calculating a position and a size of the recessed area.

In an embodiment of the invention, a brightness of the recessed area is less than 90% of an average brightness of a contoured region of all layers of the fused image data.

In an embodiment of the present invention, the melting detecting step further has a recessed region processing path substep, after the recessed region detecting substep, calculating a recessed region according to a planned processing path and the position and size of the recessed region Processing path.

In an embodiment of the present invention, in the melting repairing step, a plurality of tools of the processing mechanism are used to ream the surface of the workpiece according to the processing path of the recessed area, and then a laser cladding of the processing mechanism is utilized. The device performs laser cladding on the surface of the workpiece.

In an embodiment of the present invention, after the powdering step, a powder coating detecting step is further used to capture a post-powder image data of the powder bed platform by the camera, and transmit the image data to the control. The device is tested.

In an embodiment of the present invention, the powdering detecting step has: a step of detecting a powdering test, detecting a brightness of all layer regions of the image data after the powdering; and a step of detecting a warping detecting step of detecting the powdering A brightness of the contour area of all layers of the post-image data.

In an embodiment of the invention, in the step of polluting the sub-step, the paving If an unpaved area of the post-image data is more than 30% of the area of the cut layer, the powdering is judged to be poor.

In an embodiment of the present invention, in the warpage detecting substep, if a warped region of the image data after the powdering is 10% or more of the contour region of the layer, the workpiece is judged to be warped.

In an embodiment of the present invention, after the powdering detecting step, a powder coating repairing step is further included, and the controller determines whether to lay powder or exclude a powdering defect according to a detection result of the powdered image data.

In order to achieve the above object, the present invention further provides a detecting and repairing device for manufacturing a powder layer for detecting and repairing a workpiece manufactured by lamination, the detecting and repairing device comprising a powder bed unit, a repairing unit and a detecting unit; Wherein the powder bed unit has a powder bed platform, a powder laying mechanism and a laser, the powder bed platform is used to form the workpiece, and the powder laying mechanism is disposed on the powder bed platform for laying a powder on the The powder bed platform is disposed above the powder bed platform for melting the powder; the repairing unit has a moving mechanism and a processing mechanism, and the moving mechanism is disposed above the powder bed platform, and the processing mechanism is installed on the The moving mechanism is configured to repair a surface of the workpiece; the detecting unit has a camera and a controller, and the camera is disposed above the powder bed platform for capturing an image data of the powder bed platform, and the controller uses Receiving the image data, and determining whether to powder or remove the powdering defect according to the image data, or driving the processing mechanism to repair the surface of the workpiece.

In an embodiment of the present invention, the moving mechanism has a two-dimensional mobile platform and a multi-axis parallel machine, wherein the two-dimensional mobile platform is disposed above the powder bed platform, and the multi-axis parallel device is disposed on the second On the mobile platform.

In an embodiment of the invention, the processing mechanism has a plurality of tools and at least A laser cladding, wherein the tool and laser cladding are alternatively mounted on the multi-axis parallel machine.

In an embodiment of the invention, the detecting unit further has a laser contour sensor for mounting on the multi-axis parallel machine for sensing a contour of the powder bed platform.

As described above, the image data and the fused image data are captured by the camera, and then the controller scans the powdered image data and the fused image data, and determines whether there are various defects and distinctions. Various defects are finally determined by the controller to determine whether to lay out the powder or to eliminate the powder coating defect, or to drive the processing mechanism to repair the surface of the workpiece, thereby increasing the yield of the workpiece, shortening the working time, and improving the quality of the workpiece.

100‧‧‧Detection repairing device

101‧‧‧Workpiece

102‧‧‧Tool box

2‧‧‧Flour bed unit

21‧‧‧Powder bed platform

22‧‧‧Powdering mechanism

23‧‧‧Laser

24‧‧‧Powder

3‧‧‧Repair unit

31‧‧‧Mobile agencies

311‧‧‧Two-dimensional mobile platform

312‧‧‧Multi-axis parallel machine

313‧‧‧Mobile seat

32‧‧‧Processing institutions

320‧‧‧ Spindle

321‧‧‧Tools

322‧‧‧Laser Cladding

323‧‧‧ Replacement joint

4‧‧‧Detection unit

41‧‧‧ camera

42‧‧‧ Controller

43‧‧‧Laser contour sensor

5‧‧‧Map file layer

A1‧‧‧Cleaved area

A2‧‧‧Cleaved contour area

C1‧‧‧ Planning processing path

C2‧‧‧Processing area

X‧‧‧X-axis direction

Y‧‧‧Y-axis direction

S201‧‧‧Powdering steps

S202‧‧‧Powder testing steps

S202a‧‧‧Powder detection substep

S202b‧‧‧ warpage detection substep

S203‧‧‧Powder repairing steps

S204‧‧‧ Melting step

S205‧‧‧ Melting test step

S205a‧‧‧ raised area detection substep

S205b‧‧‧Recessed area detection substep

S205c‧‧‧ Raised area processing path substep

S205d‧‧‧ Sub-step of processing path in recessed area

S206‧‧‧melting repair steps

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing a preferred embodiment of the detecting and repairing device for powder layer manufacturing of the present invention; and Fig. 2 is a side view showing a preferred embodiment of the detecting and repairing device for powder laminated manufacturing of the present invention; It is a side view of another preferred embodiment of the detecting and repairing device for powder laminated manufacturing of the present invention; and FIG. 4 is a flow chart of a preferred embodiment of the detecting and repairing method for powder laminated manufacturing of the present invention; BRIEF DESCRIPTION OF THE DRAWINGS FIG. 6 is a schematic view showing a cut layer of a pattern in a preferred embodiment of the method for detecting a repair of a powdered layer of the present invention; and FIG. 6 is a definition of a preferred embodiment of the method for detecting and repairing a powdered layer of the present invention. FIG. 7 is a schematic view showing a processing path plan in a preferred embodiment of the method for detecting and repairing a powder laminated layer of the present invention; and FIG. 8 is a powder layer of the present invention; A schematic representation of a processing region in a preferred embodiment of the method of detecting a repair.

The above and other objects, features and advantages of the present invention will become more <RTIgt; Furthermore, the directional terms mentioned in the present invention, such as upper, lower, top, bottom, front, rear, left, right, inner, outer, side, surrounding, central, horizontal, horizontal, vertical, longitudinal, axial, Radial, uppermost or lowermost, etc., only refer to the direction of the additional schema. Therefore, the directional terminology used is for the purpose of illustration and understanding of the invention.

Referring to FIGS. 1 and 2, a preferred embodiment of the test repairing device for manufacturing a powder layer according to the present invention is used for detecting and repairing defects of a workpiece 101 manufactured by lamination, for example. The powder coating state is not good, the workpiece is warped, the molten surface is convex, and the molten surface is recessed. The detecting and repairing device 100 includes a powder bed unit 2, a repairing unit 3, and a detecting unit 4. The detailed construction, assembly relationship, and operation principle of each element will be described in detail below.

Referring to Figures 1 and 2, the powder bed unit 2 has a powder bed platform 21, a powder spreading mechanism 22, a laser 23, and a powder feeder 24, wherein the powder bed platform 21 is configured to form The workpiece 101 is disposed on the powder bed platform 21 for laying a powder on the powder bed platform 21; the laser 23 is disposed above the powder bed platform 21 for melting the powder Shape The workpiece 101 is disposed; and the powder feeder 24 is disposed above the powder bed platform 21 for storing the powder, and the powder is supplied to the powder spreading mechanism 22 for powdering.

Referring to FIGS. 1 and 2, the repairing unit 3 has a moving mechanism 31 and a processing mechanism 32, and the processing mechanism 32 is mounted on the moving mechanism 31 for repairing a surface of the workpiece 101. The moving mechanism 31 has a two-dimensional mobile platform 311 and a multi-axis parallel machine 312. The two-dimensional mobile platform 311 is disposed above the powder bed platform 21, and the multi-axis parallel machine 312 is disposed on the two-dimensional mobile platform 311. The two-dimensional moving platform 311 can drive the multi-axis parallel implement 312 to move along the X-axis direction by using a crossbar disposed in an X-axis direction X, or drive the rod with a longitudinal rod disposed in the Y-axis direction Y. The multi-axis parallel machine 312 moves along the Y-axis direction Y. In addition, the processing mechanism 32 has a plurality of cutters 321 and at least one laser cladding 322, wherein the cutters 321 are placed in a cutter box 102 and mounted on a replacement joint 323 by mounting a spindle 320, wherein A replacement joint 323 is disposed at a bottom of a moving seat 313 of the multi-axis parallel machine 312; and the laser cladding 322 can also be mounted on the replacement joint 323 to enable the cutter 321 and the laser cladding A 322 is alternatively mounted for use on the multi-axis parallel implement 312. In this embodiment, the multi-axis parallel machine 312 is a three-axis or five-axis parallel machine for controlling the movement of the movable seat 313 toward three or five axes, so that the cutters 321 and the laser The cladding 322 can be machined in any area of the surface of the workpiece 101.

With reference to the first and second figures, the detecting unit 4 has a camera 41 and a controller 42. The camera 41 is disposed above the powder bed platform 21 for capturing an image data of the powder bed platform 21; The controller 42 is configured to receive the image data, determine whether to lay out powder or exclude the powdering defect according to the image data, or drive the processing mechanism 32 to repair the surface of the workpiece 101.

According to the above structure, the powder feeder 24 is passed through during the dusting detection process. The powder is replenished to the dusting mechanism 22, and then the powder spreading mechanism 22 lays the powder on the powder bed platform 21, and the camera 41 is used to capture a post-powder image data of the powder bed platform 21. And transmitting to the controller 42 for detecting to obtain a powder-laying state on the powder bed platform 21 and a warping state of the workpiece 101, and the controller 42 determines whether or not according to the detection result of the image data after the powdering. Paving or eliminating the powder coating defects. Further, during the melt detection, the powder deposited on the powder bed platform 21 is melted through the laser 23, the powder is melted on the workpiece 101, and a melt of the powder bed platform 21 is photographed by the camera 41. The image data is sent to the controller 42 for detection to obtain a convex state and a concave state of a surface of the workpiece 101, and the controller 42 determines whether to drive according to the detection result of the melted image data. The processing mechanism 32 repairs the surface of the workpiece 101.

In addition, in another embodiment, as shown in FIG. 3, the detecting unit 4 further has a laser contour sensor 43 which can also be mounted on the replacement joint 323 for sensing the powder bed platform 21. A contour is detected, and the convex state and the concave state are detected according to the contour, and it is determined whether the processing mechanism 32 is driven to repair the surface of the workpiece 101. It should be noted that the detecting unit 4 can be detected by the camera 41 alone, such as a Charge-coupled Device (CCD), or both the camera 41 or the laser profile sensor 43 can be used for detection. It is not limited by this embodiment.

With the above design, the image data and the fused image data are captured by the camera 41, and then the controller 42 detects the powdered image data and the fused image data, and determines whether the image is present. Various defects and distinguishing various defects such as a powdering state, a warping state, a convex state, and a concave state. Finally, the controller 42 determines whether to powder or remove the powdering defect, or drives the processing mechanism 32 to repair the surface of the workpiece 101. Thereby, the yield of the workpiece 101 is increased, the working time is shortened, and the quality of the workpiece 101 is improved.

Referring to FIG. 4 and in conjunction with FIGS. 1 and 2, a preferred embodiment of the method for detecting and repairing a powder laminate according to the present invention is a workpiece manufactured by the above-described powder repairing repairing apparatus 100. The detecting and repairing method comprises a powdering step S201, a powdering detecting step S202, a powdering repairing step S203, a melting step S204, a melting detecting step S205, and a melting repairing step S206.

With reference to Fig. 4 and in conjunction with Figs. 1 and 2, in the powder spreading step S201, a powder is supplied to a powder spreading mechanism 22 by a powder feeder 24, and then the powder spreading mechanism 22 applies the powder. Laying on a powder bed platform 21.

It should be noted that, as shown in FIGS. 5 and 6, a plurality of image cut layers 5 are stacked to form a stereoscopic image of the workpiece 101, and the workpiece 101 is formed by layering layers 5 according to the pattern. Each of the image cut layers 5 has a layer area A1 and a layer area A2 of all layers.

Referring to FIG. 4 and in conjunction with FIGS. 1 and 2, in the dusting detecting step S202, a powdered image data of the powder bed platform 21 is captured by a camera 41 and transmitted to the controller 42. Specifically, the dusting detecting step S202 has a powdering detecting sub-step S202a and a warping detecting sub-step S202b, and the polling detecting sub-step S202a is detecting the sliced area A1 of the laid-up image data. a brightness for obtaining a powdered state on the powder bed platform 21, wherein a size of the layered area A1 corresponds to a size of the powder bed platform 21; in addition, the warpage detecting sub-step S202b detects the A brightness of the sliced contour area A2 of the post-powder image data is used to obtain a warped state of the workpiece 101, wherein a dimension of the cut layer outline area A2 corresponds to a dimension of a section of the workpiece 101.

Continuing to refer to FIG. 4 and matching the first and second figures, in the powdering repairing step S203 The controller 42 determines whether to lay a powder or exclude a powdering defect based on a detection result of the image data after the powdering. For example, the powdering state on the powder bed platform 21 is not good, and it is judged that the powdering is stopped; or the workpiece 101 is in a warped state, and it is judged that the warpage state of the workpiece 101 is excluded.

Referring to Fig. 4 and in conjunction with Figs. 1 and 2, in the melting step S204, the powder deposited on the powder bed platform 21 by a laser 23 is melted, and the powder is melted on the workpiece 101.

Referring to FIG. 4 and in conjunction with FIGS. 1 and 2, in the melting detecting step S205, a molten image data of the powder bed platform 21 is imaged by the camera 41, and transmitted to the controller 42 for detection. The melting detecting step S205 has a bump detecting sub-step S205a, a recess detecting sub-step S205b, a bump processing path sub-step S205c, and a recess processing path sub-step S205d.

Specifically, the raised area detecting sub-step S205a is a raised area for detecting the molten image data, and calculates a position and a size of the raised area to obtain a convex state of a surface of the workpiece 101. In this embodiment, a brightness of the raised area is greater than 110% of an average brightness of the sliced transport area A2 of the molten image data. Moreover, the raised area processing path sub-step S205c is after the raised area detecting sub-step S205a, as shown in FIGS. 7 and 8, according to a planned processing path C1 and the processed area C2 (raised area) And size to calculate a raised area processing path.

In addition, the recessed area detecting sub-step S205b is a recessed area for detecting the molten image data, and calculating a position and a size of the recessed area for obtaining a recessed state of a surface of the workpiece 101; One brightness is 90% or less of the average brightness of the sliced contour area A2. Moreover, the recessed area processing path sub-step S205d is a sub-step of detecting in the recessed area After S205b, as shown in Figs. 7 and 8, a recessed area processing path is calculated based on the position and size of a planned processing path C1 and the processed area C2 (recessed area).

In addition, as shown in FIG. 3, a contour of the powder bed platform 21 may be sensed by a laser contour sensor 43 and the position and size of the raised area or the position and size of the concave area may be calculated. The height of the raised area is greater than the thickness of the two layers, and the depth of the depressed area is greater than the thickness of the two layers.

Referring to FIG. 3 and in conjunction with FIGS. 1 and 2, in the melt repairing step S206, the controller 42 may perform a detection result of the molten image data, for example, a convex state or a depression of the surface of the workpiece 101. The state is determined whether a machining mechanism 32 is driven to repair the surface of the workpiece 101. In the present embodiment, in the melt repairing step S206, the surface of the workpiece 101 is first processed by the plurality of cutters 321 of the processing mechanism 32. The hole is reamed, and then the surface of the workpiece 101 is laser-clad by a laser cladding 322 of the processing mechanism 32.

As described above, the image data and the fused image data are captured by the camera 41, and then the controller 42 detects the powdered image data and the fused image data, and determines whether there are various defects. And distinguishing various defects, such as a powdering state, a warping state, a convex state, and a concave state, and finally determining, by the controller 42, whether to lay or remove the powdering defect, or driving the processing mechanism 32 to repair the workpiece 101. The surface thereby increases the yield of the workpiece 101, shortens the working time, and improves the quality of the workpiece 101.

The present invention has been disclosed in its preferred embodiments, and is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

100‧‧‧Detection repairing device

101‧‧‧Workpiece

102‧‧‧Tool box

2‧‧‧Flour bed unit

21‧‧‧Powder bed platform

22‧‧‧Powdering mechanism

23‧‧‧Laser

24‧‧‧Powder

3‧‧‧Repair unit

31‧‧‧Mobile agencies

311‧‧‧Two-dimensional mobile platform

312‧‧‧Multi-axis parallel machine

313‧‧‧Mobile seat

32‧‧‧Processing institutions

320‧‧‧ Spindle

321‧‧‧Tools

322‧‧‧Laser Cladding

323‧‧‧ Replacement joint

4‧‧‧Detection unit

41‧‧‧ camera

42‧‧‧ Controller

Claims (18)

A method for detecting and repairing a powder layer manufacturing method for detecting and repairing a workpiece manufactured by lamination, the method for detecting and repairing comprises: a step of paving powder, using a powder laying mechanism to lay a powder on a platform of a powder bed; a melting step of melting a powder deposited on the platform of the powder bed by a laser; a melting detecting step of photographing a molten image of the powder bed platform by a camera and transmitting it to a controller for detection; and melting In the repairing step, the controller determines whether to drive a processing mechanism to repair a surface of the workpiece according to a detection result of the molten image data. The method for detecting and repairing a powder laminate according to the first aspect of the invention, wherein the melting detecting step has a convex region detecting substep for detecting a convex region of the molten image data, and calculating the convexity A location and a size of the zone. The method for detecting and repairing a powder laminate according to the second aspect of the invention, wherein a brightness of the convex region is more than 110% of an average brightness of a contour region of the layer of the melted image data. The method for detecting and repairing a powder laminate according to the second aspect of the invention, wherein the melting detecting step further comprises a processing step of a raised area, after the detecting sub-step of the raised area, according to a planned processing path and The position and size of the raised area calculate a processing path of the raised area. The method for detecting and repairing a powder laminate according to the invention of claim 4, wherein in the melting repairing step, the surface of the workpiece is processed according to the processing path of the raised portion by a plurality of tools of the processing mechanism. The method for detecting and repairing a powder laminated layer according to the first aspect of the invention, wherein the melting detecting step has a recessed area detecting substep, detecting a depressed area of the molten image data, and calculating a position of the depressed area and One size. The method for detecting and repairing a powder laminate according to claim 6, wherein a brightness of the recessed area is less than 90% of an average brightness of a contour region of the layer of the melted image data. The method for detecting and repairing a powder laminate according to the sixth aspect of the invention, wherein the melting detecting step further comprises a recessed region processing path substep, after the recessed region detecting substep, according to a planned processing path and the recess The location and size of the zone calculates a processing path for the recessed zone. The method for detecting and repairing a powder laminated layer according to claim 8, wherein in the melting repairing step, the surface of the workpiece is reamed according to the processing path of the recessed area by using a plurality of tools of the processing mechanism, and then The surface of the workpiece is laser cladding using a laser cladding of the processing mechanism. The method for detecting and repairing a powder laminate according to claim 1, wherein after the powdering step, a powder coating detecting step is adopted, wherein the powder detecting step is to use the camera to photograph a shop of the powder bed platform. The post-powder image data is transmitted to the controller for testing. The method for detecting and repairing a powder laminate according to claim 10, wherein the step of detecting the powder has a step of detecting a powder, detecting a brightness of a layer of all layers of the image after the layering; and The warpage detecting substep detects a brightness of a contour region of all layers of the image after the spreading. The method for detecting and repairing a powder laminate according to the invention of claim 11, wherein in the step of detecting the powder, an unpaved area of the image after the powdering is more than 30% of the area of the layer, Then judge the poor powdering. The method for detecting and repairing a powder laminate according to the invention of claim 11, wherein in the warpage detecting substep, a warpage area of the image data after the layering is more than 10% of the contour area of the layer, Then the workpiece is judged to be warped. The method for detecting and repairing a powder laminate according to claim 10, wherein after the powdering detecting step, a powder cleaning step is further included, and the controller determines whether the film is based on the detection result of the image data after the powdering Plastering or eliminating a powder defect. A detecting and repairing device for manufacturing a powder layer for detecting and repairing a workpiece manufactured by lamination, the detecting and repairing device comprising: a powder bed unit having: a powder bed platform for forming the workpiece; and a powder laying mechanism And disposed on the powder bed platform for laying a powder on the powder bed platform; and a laser disposed above the powder bed platform for melting the powder; and a repairing unit having: a moving mechanism Provided above the powder bed platform; and a processing mechanism mounted on the moving mechanism for repairing a surface of the workpiece; and a detecting unit has: a camera disposed above the powder bed platform for capturing an image data of the powder bed platform; and a controller for receiving the image data, and determining whether to spread the powder according to the image data Or to eliminate a powder defect, or drive the processing mechanism to repair the surface of the workpiece. The detecting and repairing device for powder lamination manufacturing according to claim 15, wherein the moving mechanism has: a two-dimensional mobile platform disposed above the powder bed platform; and a multi-axis parallel machine disposed on the second On the mobile platform. The detecting and repairing device for powder laminated manufacturing according to claim 16, wherein the processing mechanism has a plurality of cutters and at least one laser cladding, the cutters and the laser claddings are alternatively mounted on the Multi-axis parallel machine. The detecting and repairing device for powder laminated manufacturing according to claim 16, wherein the detecting unit further has a laser contour sensor for mounting on the multi-axis parallel machine for sensing the powder A silhouette of the bed platform.