WO2019002687A1

WO2019002687A1 - Non-repudiation of items produced with 3d printer

Info

Publication number: WO2019002687A1
Application number: PCT/FI2018/050507
Authority: WO
Inventors: Arto Juhola; Markku KYLÄNPÄÄ; Aarne Rantala
Original assignee: Teknologian Tutkimuskeskus Vtt Oy
Priority date: 2017-06-28
Filing date: 2018-06-27
Publication date: 2019-01-03

Abstract

A solution for monitoring the manufacturing of items with a 3D printer is presented. The solution comprises detecting (302) initiation of a manufacturing process where a 3D printer is used to manufacture an item; controlling (306) one or more sensors to obtain first information from the input materials to be utilised by the 3D printer during the manufacturing process; controlling (308) one or more sensors to obtain second information the 3D printer and the item being produced by the 3D printer during the manufacturing process; controlling (310) one or more sensors to obtain third information the item after the manufacturing process; storing (312) the first, second and third information; creating (314) from the first, second and third information an identification for the manufactured item.

Description

NON-REPUDIATION OF ITEMS PRODUCED WITH 3D PRINTER

Technical Field

The exemplary and non-limiting embodiments of the invention relate generally to non-repudiation of produced items. Embodiments of the invention relate especially to solutions where a 3D-printer is utilised to produce items.

Background

3D printing, or additive manufacturing, has gained large interest in recent times. In 3D printing three dimensional physical items are created from lay- ers of materials and where the process is controlled by a computer or a processor with software. Typically the computer is loaded with instructions of how different layers are produced. The instructions may be based on a 3D model of an existing object or may be computer generated.

In some cases 3D printing may be used to produce items that need to be of exactly right shape and given composition. This is the case, for example, when spare parts of machines or such are produced using 3D printers. Thus, the producer of the items must be able to provide a proof that the items are correctly manufactured.

Brief description

An object of the present invention is to provide a method and an apparatus for implementing the method so as to overcome the above problem. The objects of the invention are achieved by an apparatus for monitoring the manufacturing of items with a 3D printer, comprising: at least one processor; and at least one memory including a computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the arrangement to: detect initiation of a manufacturing process where a 3D printer is used to manufacture an item, control one or more sensors to obtain first information from the input materials to be utilised by the 3D print- er during the manufacturing process, control one or more sensors to obtain second information the 3D printer and the item being produced by the 3D printer during the manufacturing process, control one or more sensors to obtain third information the item after the manufacturing process, store the first, second and third information, and create from the first, second and third information an iden- tification for the manufactured item.

The objects of the invention are also achieved by a method for monitoring the manufacturing of items with a 3D printer, comprising: detecting initiation of a manufacturing process where a 3D printer is used to manufacture an item, controlling one or more sensors to obtain first information from the input materials to be utilised by the 3D printer during the manufacturing process, controlling one or more sensors to obtain second information the 3D printer and the item being produced by the 3D printer during the manufacturing process, controlling one or more sensors to obtain third information the item after the manufacturing process, storing the first, second and third information, and creating from the first, second and third information an identification for the manufactured item.

The embodiments of the invention are disclosed in the dependent claims.

Brief description of the drawings

In the following the invention will be described in greater detail by means of preferred embodiments with reference to the attached [accompanying] drawings, in which

Figure 1 illustrates an example arrangement;

Figure 2 illustrates an example operation of the arrangement;

Figure 3 is a flowchart illustrating an embodiment;

Figure 4 illustrates the structure of an example arrangement.

Detailed description of some embodiments

3D printing, or additive manufacturing (AM) is a relatively new technology that is under constant development. New areas where AM may be used are constantly under study. The performance of 3D printers is increasing and prices of 3D printers are going down. It can be foreseen that the use of AM is increasing in the future.

AM may be used in many applications and phases of product lifecycle. Preliminary products may be easily manufactured using 3D printers. Thus, product development, prototyping, piloting and product testing is easier when AM is used. Products may be tested even if the final product might be manufactured using another method. Furthermore, also final products and/or spare parts may be manufactured using AM. In particularly in these phases it is advantageous if the authenticity of the products and/or spare parts may be verified to a customer. In addition, the products manufactured using AM may be such that the authenticity of the products is vital. For example, in a not so distant future 3D printing is envisioned to be used for sensitive operations like printing/creating doses of medicines. Such applications will require high level of security.

Digital Rights Management DRM may be associated with 3D printing.

Thus, the printing device may be controlled by DRM issues. For example, the number of the 3D copies produced with the printer may be limited. There may be a possibility that due to the printer malfunction, incorrect customer expectations or fraudulent reporting of printer malfunction the provider of the DRM protected model will receive reclamations. To settle such reclamation, a non-repudiable means of verifying the correct production of a given 3D item is needed.

Thus, there is a need for means to supervise the production of the 3D items in such a manner that enables recognition of possible errors in the production. This is necessary for both security (e.g fraud protection) and safety (guaran- teeing the safe use of the 3D item) reasons.

Embodiments of the present invention describe a solution for producing undeniable proofs (non-repudiation) of correct manufacturing of a given physical item. Such proofs are needed in the event of product failures leading to disputes about the responsibility of the occurred damages (mishandling or mis- use from the part of the user is often a possibility, too).

In an embodiment, the solution comprises of a DRM capable 3D printer and an associated supervisory equipment, both being parts of a trusted platform (a platform whose identity, configuration and operation can be verified by a remote, supervisory system).

Figure 1 illustrates an example of an arrangement according to an embodiment of the invention.

The solution comprises of a DRM capable 3D printer 100 and a supervisory equipment or monitoring arrangement 102. In an embodiment, the monitoring arrangement 102 comprises a monitoring apparatus 104 and one or more sensors 106. In an embodiment, the monitoring arrangement 102 forms a trusted platform (a platform whose identity, configuration and operation can be externally - via a network - verified). The monitoring apparatus 104 comprises a processing device configured to gather data using the sensors 106.

In an embodiment, the monitoring arrangement 102 and the 3D print- er may be integrated forming a single device 108.

Sensors of various types may be utilised. A non-limiting example of possible sensors comprise a camera, a weight sensor, an infrared sensor, a pressure sensor, a thermometer, and a humidity sensor.

In an embodiment, the monitoring arrangement 102 or monitoring apparatus 104 may be connected to a control apparatus 110 and a storage 112. The control apparatus 110 may be a network computer comprising information on 3D models of items to be produced by the 3D printer 100. The storage 112 may be a memory configured to store information generated by the monitoring arrangement 102, for example.

Figure 2 illustrates an example of the general operation of the ar- rangement. In an embodiment, the monitoring apparatus 104 may be configured to monitor and record 200 input to the 3D printer 100, such as the 3D model of the item to be produced and the materials or parts to be used by the 3D printer. The monitoring apparatus 104 may be configured to monitor and record 202 the actual manufacturing phase of the item to be produced. The monitoring may comprise monitoring the item at different phases of the manufacturing and the manufacturing environments. Further, the monitoring apparatus 104 may be configured to monitor and record 204 the output of the 3D printer, i.e. the manufactured product. The product may be a finished product or an intermediate product which may be an input to manufacturing another item.

Figure 3 is a flowchart illustrating an embodiment. The example of figure 3 illustrates the operation of the monitoring arrangement 102.

In step 300, the monitoring apparatus 104 may be configured to verify the validity of the arrangement. This may be performed by reading one or more sensors and detecting that the equipment has not been tampered with. Further, the software or computer program code run in the monitoring arrangement may be verified to be authentic. This may be performed by a Trusted Platform Module TPM, which may be a part of the monitoring arrangement.

In an embodiment, the verifying may comprise checking signs of opening a protective casing of the 3D printer, signs of modifying subsystems (such as sensors) and signs of altering the computing related parts, involving the checking of correct physical, firmware and software composition, configuration and authentication and integrity checking of components, for example. Important external services may be checked as well (such as secure Network Time Protocol, NTP).

In step 302, the monitoring apparatus 104 may be configured to detect initiation of a manufacturing process where a 3D printer is used to manufacture an item. The initiation may come from the control apparatus 110, for example.

In step 304, the monitoring apparatus 104 may be configured to receive instructions for 3D printer to manufacture an item, and pass the information to the 3D printer. The instructions may be received from the control appa- ratus 110, for example.

In step 306, the monitoring apparatus 104 may be configured to control one or more sensors to obtain first information from the input materials to be utilised by the 3D printer during the manufacturing process, as described above.

In step 308, the monitoring apparatus 104 may be configured to con- trol one or more sensors to obtain second information the 3D printer and the item being produced by the 3D printer during the manufacturing process.

In an embodiment, to guarantee that the system is indeed following the built 3D item and not some false input, suitable random elements or random ordering or timing (of events) may be added to the build process of the item that can be detected at this phase. Also, the timing of the events needs to be verifiable where this is relevant to the process. The monitoring arrangement 102 is kept up- to-date of the phase of the process.

Thus, the item to be produced may comprise given features, which may be visible at given time instant during manufacturing. If the monitoring ap- paratus 104 detects these features at determined time instants, all is well and the monitoring apparatus 104 may determine that at this phase correct item is being produced with valid manufacturing instructions.

In step 310, the monitoring apparatus 104 may be configured to control one or more sensors to obtain third information the item after the manufac- turing process. Properties of the finished or intermediate product may be examined using sensors. For example, a camera may be controlled to obtain images of the product which images may be analysed.

In step 312, the monitoring apparatus 104 may be configured to store the first, second and third information. The obtained information may be stored locally or top a remote storage 112.

In step 314, the monitoring apparatus 104 may be configured to create from the first, second and/or third information an identification for the manufactured item.

In an embodiment, the obtained information is encrypted (316) with a private key of the manufacturer of the product to obtain a certificate ensuring the authenticity of the manufactured item. Thus in an embodiment, the proposed solution is based on two components: a unique ID of the manufactured physical object that is relatively easy to create and read but prohibitively expensive to clone, and a cryptographic certificate that binds the unique ID to a certain manufacturer (and product line, etc.).

One example of a unique ID is a bit vector that is the result of a sensor measurements of production variations that are not essential regarding to the actual use of the object and can be measured relatively easily, but whose sufficiently exact reproduction is prohibitively difficult and/or expensive. Additionally, the ID must be stable, i.e. every measurement should produce (at least after error correction) the same result. For example, surface irregularities (pits and bumps) in such a location where surface quality is not essential could be used. Preferably, location should be such that measurement is relatively easy but intentional modification is difficult and reproduction of a predefined pattern is prohibitively difficult (accessible enough to be measured but not accessible enough to be modified 'too accurately', for example).

Binding the object to its manufacturer may be achieved using a cryptographic certificate: During some convenient production step after the unique ID is created and there is not anymore any significant risk that it could be modified, it is read (i.e. a bit vector representing the measurement is computed) and it is combined with appropriate manufacturer and manufacturing info to a certificate that is signed using the said manufacturer's private signing key. Thereafter, the certificate can be verified using the corresponding public key, which can only be used to verify certificates but not to create (or forge) new ones. Forging certificates is only possible if the manufacturer's private signing key is leaked, and therefore the manufacturer should diligently protect it.

In an embodiment, the monitoring apparatus may be configured to compare the obtained information to a given data and produce an error if there is a difference.

For example, the monitoring apparatus may be configured to compare the gathered data using the sensors with the model to be printed. If discrepancies are detected between the current supposed construction phase of the model and the obtained data, an error may be raised. To guarantee that the monitoring apparatus is indeed following the built 3D item and not some false input, suitable random elements can be added to the build process of the item that can be detected by the monitoring arrangement. Also, the timing of the events needs to be verifiable. This printing time image material, especially about intentionally inserted se- mirandom elements, can be used to identify the authorised item from unauthorised copies.

Figure 4 illustrates the structure of an example arrangement. The figure illustrates a simplified example of an arrangement 102 in which embodiments of the invention may be applied.

It should be understood that the apparatus is depicted herein as an example illustrating some embodiments. It is apparent to a person skilled in the art that the apparatus may also comprise other functions and/or structures and not all described functions and structures are required. Although the apparatus has been depicted as one entity, different modules and memory may be implemented in one or more physical or logical entities.

The arrangement may comprise a monitoring apparatus 104 and a set of sensors 106.

The apparatus 104 of the example includes a control circuitry 400 con- figured to control at least part of the operation of the apparatus.

The apparatus may comprise a memory 402 for storing data. Furthermore the memory may store software 404 executable by the control circuitry 400. The memory may be integrated in the control circuitry.

The apparatus may comprise one or more interfaces 406 configured to communicate with the sensors 106. The apparatus may further comprise one or more interfaces 408 configured to communicate with the 3D printer 100, the control apparatus 110 and the storage 112. The interfaces may utilise different communication methods. For example, the interfaces may utilise radio communication (such as Bluetooth™, Bluetooth™ low energy, ZigBee, IEEE 488, for exam- pie), infrared communication, USB (Universal Serial Bus), Ethernet, HDMI (High Definition Multimedia Interface), to name a few. Various protocols may be used in communication, such as TCP/IP (Transmission Control Protocol / Internet Protocol), CoAP (Constrained Application Protocol), for example. The connections may be wired or wireless.

The one or more interfaces 408 may be used to receive 3D model data from control apparatus 110. Also information obtained before, during and after the manufacturing process may be sent from the monitoring arrangement using the interface. In addition to data transfer, the interface may provide a control channel. Also the 3D printer may be controlled utilising the interface. It may be noted that the interfaces to the 3D printer and to control apparatus 110 may utilise different technologies. The control circuitry 400 is configured to execute one or more applications. The applications may be stored in the memory 402.

In an embodiment, the apparatus may further comprise a Trusted Platform Module, TPM, circuitry 410. The Trusted Platform Module 410 is a separate circuitry or a computer chip such as a microcontroller that can securely store data used in authentication. The data may comprise passwords, certificates, or cryptographic keys. The TPM circuitry may comprise one or more special registers such as a platform configuration register (PCR) to store information. The registers may comprise data which is utilised in encryption. The data may be unchangeable by the user and it may be based on hash values which are stored in the apparatus and which are apparatus specific. Several commercial enterprises manufacture TPM circuitries.

In an embodiment, the apparatus may further comprise user interface 412 operationally connected to the control circuitry 400.

The arrangement of Figure 4 may also comprise other units such as clock, various buses, and power source, for example.

The steps and related functions described in the above and attached figures are in no absolute chronological order, and some of the steps may be performed simultaneously or in an order differing from the given one. Other func- tions can also be executed between the steps or within the steps. Some of the steps can also be left out or replaced with a corresponding step.

The apparatuses or controllers able to perform the above-described steps may be implemented as an electronic digital computer, or a circuitry which may comprise a working memory (RAM), a central processing unit (CPU), and a system clock. The CPU may comprise a set of registers, an arithmetic logic unit, and a controller. The controller or the circuitry is controlled by a sequence of program instructions transferred to the CPU from the RAM. The controller may contain a number of microinstructions for basic operations. The implementation of microinstructions may vary depending on the CPU design. The program in- structions may be coded by a programming language, which may be a high-level programming language, such as C, Java, etc., or a low-level programming language, such as a machine language, or an assembler. The electronic digital computer may also have an operating system, which may provide system services to a computer program written with the program instructions.

As used in this application, the term 'circuitry' refers to all of the following: (a) hardware-only circuit implementations, such as implementations in only analog and/or digital circuitry, and (b) combinations of circuits and software (and/or firmware), such as (as applicable): (i) a combination of processor(s) or (ii) portions of processor(s)/software including digital signal processor(s), software, and memory(ies) that work together to cause an apparatus to perform var- ious functions, and (c) circuits, such as a microprocessor(s) or a portion of a mi- croprocessor(s), that require software or firmware for operation, even if the software or firmware is not physically present.

This definition of 'circuitry' applies to all uses of this term in this application. As a further example, as used in this application, the term 'circuitry' would also cover an implementation of merely a processor (or multiple processors) or a portion of a processor and its (or their) accompanying software and/or firmware. The term 'circuitry' would also cover, for example and if applicable to the particular element, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a similar integrated circuit in a server, a cellular network device, or another network device.

An embodiment provides a computer program embodied on a distribution medium, comprising program instructions which, when loaded into an electronic apparatus, are configured to control the apparatus to execute the embodiments described above.

The computer program may be in source code form, object code form, or in some intermediate form, and it may be stored in some sort of carrier, which may be any entity or device capable of carrying the program. Such carriers include a record medium, computer memory, read-only memory, and a software distribution package, for example. Depending on the processing power needed, the computer program may be executed in a single electronic digital computer or it may be distributed amongst a number of computers.

The apparatus may also be implemented as one or more integrated circuits, such as application-specific integrated circuits ASIC. Other hardware embodiments are also feasible, such as a circuit built of separate logic components. A hybrid of these different implementations is also feasible. When selecting the method of implementation, a person skilled in the art will consider the requirements set for the size and power consumption of the apparatus, the necessary processing capacity, production costs, and production volumes, for example.

In an embodiment, the arrangement for monitoring the manufacturing of items with a 3D printer comprises means for detecting initiation of a manufacturing process where a 3D printer is used to manufacture an item, means for con- trolling one or more sensors to obtain first information from the input materials to be utilised by the 3D printer during the manufacturing process, means for controlling one or more sensors to obtain second information the 3D printer and the item being produced by the 3D printer during the manufacturing process, means for controlling one or more sensors to obtain third information the item after the manufacturing process, means for storing the first, second and third information, and means for creating from the first, second and third information an identification for the manufactured item.

It will be obvious to a person skilled in the art that, as the technology advances, the inventive concept can be implemented in various ways. The invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.

Claims

1. An apparatus for monitoring the manufacturing of items with a 3D printer, comprising:

at least one processor; and at least one memory including a computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the arrangement to

detect initiation of a manufacturing process where a 3D printer is used to manufacture an item;

control one or more sensors to obtain first information from the input materials to be utilised by the 3D printer during the manufacturing process;

control one or more sensors to obtain second information the 3D printer and the item being produced by the 3D printer during the manufacturing process;

control one or more sensors to obtain third information the item after the manufacturing process;

store the first, second and third information;

create from the first, second and third information an identification for the manufactured item.

2. The apparatus according to claim 1, wherein the sensors comprise at least one of following: a camera, a weight sensor, an infrared sensor, a pressure sensor, a thermometer, a humidity sensor.

3. The apparatus according to claim 1 or 2, the arrangement further comprising a trusted platform module, wherein the trusted platform module is configured to verify the computer program code to be executed by the at least one processor.

4. The apparatus according to any preceding claim, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the arrangement to

encrypt the obtained identification with a manufacturing key to obtain a certificate ensuring the authenticity of the manufactured item.

5. The apparatus according to any preceding claim, wherein the ar- rangement is configured to receive instructions for 3D printer to manufacture an item, and pass the information to the 3D printer.

6. The apparatus according to any preceding claim, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the arrangement to

compare the obtained information to a given data and produce an error if there is a difference.

7. A method for monitoring the manufacturing of items with a 3D printer, comprising

detecting initiation of a manufacturing process where a 3D printer is used to manufacture an item;

controlling one or more sensors to obtain first information from the input materials to be utilised by the 3D printer during the manufacturing process;

controlling one or more sensors to obtain second information the 3D printer and the item being produced by the 3D printer during the manufacturing process;

controlling one or more sensors to obtain third information the item after the manufacturing process;

storing the first, second and third information;

creating from the first, second and third information an identification for the manufactured item.

8. The method according to claim 7, further comprising verifying by a trusted platform module the computer program code to be executed by the at least one processor.

9. The method according to any preceding claim 7 to 8, further comprising encrypting the obtained identification with a manufacturing key to obtain a certificate ensuring the authenticity of the manufactured item.

10. The method according to any preceding claim 7 to 9, further comprising receiving instructions for 3D printer to manufacture an item and passing the information to the 3D printer.