Method of controlling a vacuum pump

Abstract

Method for controlling (100) a real vacuum pump (1) comprising the following steps: the operation of the real vacuum pump (1) is simulated in real time by virtually operating a dynamic digital representation of the real vacuum pump (1) under operating conditions of the real vacuum pump (1), at least one estimated value of a physical output quantity is determined at a determined location of the virtual vacuum pump, the at least one estimated value of the determined physical output quantity is used as an input signal of a control law or a correspondence table, an output data item of which allows the control of a physical element of the real vacuum pump (1) and / or for the emission of a signal representative of an operating state of the real vacuum pump (1). Abstract figure: Figure 1

Description

Title of the invention: Method for controlling a vacuum pump Technical field of the invention

[0001] The present invention relates to a method for controlling a vacuum pump and a vacuum pump. Technical background

[0002] Vacuum pumps generally comprise one or two rotors driven by a motor to rotate in the stator. During rotation, the sucked gas is trapped in the free space between the at least one rotor and the stator, to be discharged towards the outlet.

[0003] Vacuum pumps are notably used in manufacturing processes for semiconductors, flat screens or photovoltaic substrates or for instrumentation applications, requiring a pressure lower than atmospheric pressure.

[0004] In certain pumping applications, particularly in semiconductor manufacturing processes, the gases used can be transformed into solid by-products which can be deposited in the form of a layer on the moving and static parts of the pump. These deposits can lead to a restriction of clearance between the stator and the at least one rotor, which can cause the rotor to seize. It is known to heat the stator to prevent condensation of reaction products and thus limit the formation of deposits in the vacuum pump and increase its service life.

[0005] In addition to limiting the formation of deposits, it may be necessary to increase the operating temperature of the rotor for other considerations. Indeed, in the case of turbomolecular vacuum pumps, increasing the temperature of the vacuum pump may be necessary, for example, to increase the flow of gas to be pumped or the pumping of heavier gases. However, care must be taken to ensure that the temperature of the rotor does not exceed a certain high threshold in order to preserve its mechanical strength. Irreversible deformations of the rotor (or fining) may occur at high temperatures and risk causing the stator to touch the most expanded part of the rotor.

[0006] It is further necessary to cool the motor, bearings or other components of the vacuum pumps to avoid malfunction. Furthermore, in some applications, the stator temperature must be controlled so as not to exceed a predefined maximum beyond which the pumped gaseous species could agglomerate in the vacuum pump and cause it to seize.

[0007] Temperature control is therefore a determining factor for the lifespan of vacuum pumps. However, the temperature measurement points allowing Controlling the cooling or heating circuits are not necessarily located in the appropriate places on the vacuum pump, either because the instrumentation is too expensive, too bulky, too fragile or all of these, or because it is impossible to place the sensors in certain places, such as inside the pumping chambers or near the bearings. Summary of the invention

[0008] An aim of the present invention is to at least partially resolve one of the aforementioned drawbacks, by improving the control of vacuum pumps to enable their service life to be increased.

[0009] For this purpose, the invention relates to a method for controlling a real vacuum pump comprising a stator, at least one rotor, at least one mechanical or electromagnetic bearing for guiding the rotation of the at least one rotor, a motor configured to drive the at least one rotor, characterized in that said control method comprises the following steps: - the operation of the real vacuum pump is simulated in real time by virtually operating a dynamic digital representation of the real vacuum pump under operating conditions of the real vacuum pump, in order to obtain a virtual vacuum pump, in particular called a digital twin of the vacuum pump, at least for a physical output quantity, representative of the operation of the real vacuum pump, - at least one estimated value of the physical output quantity is determined at a given location of the virtual vacuum pump, - at least one estimated value of the determined physical output quantity is used as an input signal for a control law or a correspondence table, an output data item of which allows the control of a physical element of the real vacuum pump and / or for the emission of a signal representative of an operating state of the real vacuum pump, - the virtual vacuum pump being synchronized with the real vacuum pump by at least one input time parameter of the real vacuum pump, capable of varying over time and originating from at least one physical sensor and / or a control instruction of a physical element, the values of the at least one input time parameter of the real vacuum pump being imposed on the virtual vacuum pump.

[0010] The digital twin provides access to output information on a physical temporal quantity in real time, at any point of the virtual vacuum pump, in the inter-stage channels, the pumping chambers, etc. There is thus an exchange of data between the real vacuum pump and the digital twin, in both directions to improve the control of the real vacuum pump, in particular to optimize the settings or to decide whether maintenance intervention is necessary.

[0011] According to an exemplary embodiment, the digital twin of the real vacuum pump is a dynamic digital model of fluid mechanics and / or thermal and / or structural mechanics and / or electromagnetic, solved with numerical methods such as finite elements or finite volumes. This model is rendered in real time using dynamic model order reduction techniques. This model order reduction can be done using learning tools using mathematical algorithms, such as neural networks or artificial intelligence such as machine learning, or such as statistical methods.

[0012] The control method may further comprise one or more of the features described below, taken alone or in combination.

[0013] The dynamic digital representation of the real vacuum pump includes in particular at least the virtual replica of the three-dimensional geometry of the physical elements of the real vacuum pump, in particular the stator and at least one rotor, at least one element of the at least one mechanical or electromagnetic bearing and at least one element of the motor.

[0014] The dynamic digital representation of the real vacuum pump includes in particular at least the virtual replica of the nature of the materials of the physical elements of the vacuum pump, in particular the stator and at least one rotor, at least one element of the at least one mechanical or electromagnetic bearing and at least one element of the motor.

[0015] At least one input time parameter can be chosen from: - a stator temperature measurement from a temperature sensor, - a control instruction from a gas mass flow controller, - a pressure measurement from a pressure sensor, - a recipe for equipment of a fluidically connected enclosure to the vacuum pump, - a control instruction for a valve, such as a valve in a hydraulic circuit for cooling the actual vacuum pump, - an electrical supply instruction for a resistive heating element of an electrical heating circuit or an element of the ventilation system of the actual vacuum pump, - a current consumed by the motor, - the rotation speed of at least one rotor, from a speed variator of the actual vacuum pump motor, - a gas temperature measurement from a temperature sensor arranged on the side of a suction port of the actual vacuum pump.

[0016] A determined physical output quantity of the virtual vacuum pump may be the temperature of an element of the virtual vacuum pump and / or the temperature of at least one fluid flowing through the virtual vacuum pump, in particular of at least one gas to be pumped by the virtual vacuum pump and / or of a purge fluid flowing through a purge circuit of the virtual vacuum pump and / or of a cooling fluid flowing through a hydraulic cooling circuit of the virtual vacuum pump and / or of a lubricating fluid flowing through a lubrication circuit of the virtual vacuum pump.

[0017] A determined physical output quantity of the virtual vacuum pump may be at least one partial pressure of at least one fluid flowing through the virtual vacuum pump, in particular of at least one gas to be pumped by the virtual vacuum pump and / or of a purge fluid flowing through a purge circuit of the virtual vacuum pump and / or of a cooling fluid flowing through a hydraulic cooling circuit of the virtual vacuum pump and / or of a lubricating fluid flowing through a lubrication circuit of the virtual vacuum pump.

[0018] A determined physical output quantity of the virtual vacuum pump may be a functional clearance of the virtual vacuum pump between the at least one rotor and the stator and / or between the rotors.

[0019] A determined physical output quantity of the virtual vacuum pump may be a power or a current consumed by the motor and / or a rotation speed of the at least one rotor.

[0020] The at least one estimated value of the physical output quantity can be determined at any point of the virtual vacuum pump, and in particular with regard to the temperature, at a location located in a pumping chamber of the virtual vacuum pump, such as at the walls of the pumping chambers or at least one rotor or the interior volume of the pumping chambers, or in an inter-stage channel of the virtual vacuum pump or at least one bearing of the virtual vacuum pump.

[0021] The controlled physical element of the real vacuum pump is for example an actuator of a valve or a mass flow controller of a hydraulic cooling circuit of the real vacuum pump or the actuator of a valve or a mass flow controller of a purge circuit of the real vacuum pump configured to inject a purge gas into the flow path of the pumped gases or a resistive heating element of an electrical heating circuit of the stator of the real vacuum pump, or an element of a ventilation system of the real vacuum pump or a speed variator of the real vacuum pump.

[0022] The controlled physical element of the actual vacuum pump can be controlled so as to lower the energy consumption of the actual vacuum pump, in particular electricity and / or cooling fluid and / or purge fluid.

[0023] A value of the physical quantity of the virtual vacuum pump can be determined for a future date, by considering that the value of the at least one input time parameter is fixed in time or varies according to a predetermined time evolution.

[0024] In this case, the controlled physical element of the real vacuum pump can be controlled so as to carry out a corrective action depending on the value of the physical quantity of the virtual vacuum pump for a future date.

[0025] For example, in the case where the value of the physical quantity determined for a future date predicts a malfunction or a risk of malfunction or unsuitable operating conditions of the actual vacuum pump, the controlled physical element of the actual vacuum pump can be controlled so as to carry out a corrective action with the aim of preserving the integrity of the actual vacuum pump and / or maintaining it in operational operating conditions, for example by controlling the actuators of the purge circuit and / or the hydraulic cooling circuit, for example to reduce the risks of condensation or chemical reactions or to limit energy consumption.

[0026] A representation of at least one physical output quantity of the virtual vacuum pump can be displayed.

[0027] The invention also relates to a real vacuum pump comprising a stator and at least one rotor, at least one mechanical or electromagnetic bearing for guiding the rotation of the at least one rotor, a motor configured to drive the at least one rotor, characterized in that it comprises a control unit configured to implement a control method as described previously.

[0028] The control unit may be embedded in the actual vacuum pump or be remote from the actual vacuum pump, in a network, in particular in "edge computing" or "cloud computing" in English. In "edge computing", the computing execution is relocated near the source of the data, so as to reduce the need to process the data in a remote data center. In "cloud computing" the computing execution is relocated in the "computing cloud" so as to use the memory and computing capacities of several interconnected remote servers.

[0029] The invention also relates to a computer program (also called an algorithm) comprising instructions which, when the program is executed by a computer, cause the latter to implement the steps of the method for controlling a real vacuum pump as described previously. Brief description of the figures

[0030] Other advantages and characteristics will become apparent upon reading the description. following of a particular embodiment of the invention, but in no way limiting, as well as the appended drawings in which:

[0031] [Fig.l] [Fig.l] shows a flowchart of a method for controlling a vacuum pump.

[0032] [Fig.2] [Fig.2] is a schematic longitudinal sectional view of a first example of a vacuum pump, top view, with an enlarged view of functional games.

[0033] [Fig.3] [Fig.3] shows a cross-sectional view of the vacuum pump of the [Fig.2], with an enlarged view of functional games.

[0034] [Fig.4] [Fig.4] shows a two-dimensional representation of the estimated value of the temperature of virtual elements of the digital twin of the vacuum pump, according to a longitudinal sectional view of the vacuum pump.

[0035] [Fig.5] [Fig.5] shows a two-dimensional representation of the estimated value of the partial pressure of one of the pumped gases of the digital twin of the vacuum pump, according to a cross-sectional view of the interior of a virtual pumping stage of the vacuum pump.

[0036] [Fig.6] [Fig.6] shows a two-dimensional representation of the estimated value of the temperature of the pumped gases from the digital twin of the vacuum pump, according to a cross-sectional view of the interior of a virtual pumping stage of the vacuum pump.

[0037] [Fig.7] [Fig.7] is a schematic longitudinal sectional view of a second example of a vacuum pump.

[0038] [Fig.8] [Fig.8] shows a two-dimensional representation of the estimated value of the temperature of virtual elements of the digital twin of the vacuum pump, according to a longitudinal sectional view of the vacuum pump.

[0039] In these figures, identical or similar elements have the same reference numbers.

[0040] Only the elements necessary for understanding the invention are represented. Detailed description

[0041] The following embodiments are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment, or that the features apply only to a single embodiment. Single features of different embodiments may also be combined or interchanged to provide other embodiments, without departing from the scope of the invention, as defined by the claims.

[0042] The axial direction is defined as the longitudinal direction of the vacuum pump, parallel to the axis of rotation of the at least one rotor. The transverse or radial direction is a direction perpendicular to the axial direction.

[0043] A valve is defined as any type of controllable valve, all or nothing or proportional, such as a solenoid valve.

[0044] [Fig.l] illustrates a control method 100 of an actual vacuum pump 1.

[0045] The vacuum pump 1 can be used in particular for pumping gases from the enclosure of semiconductor manufacturing equipment, flat screens or photovoltaic substrates or for instrumentation applications.

[0046] The vacuum pump 1 may be a volumetric vacuum pump, i.e. one which is configured to, using two rotors 3, 4, suck in, transfer, and then discharge the gas to be pumped. The rotors 3, 4, for example, have lobes with identical profiles, for example of the “Roots” type, the “Claw” or “screw” type or the “Scroll” type or another similar principle of volumetric vacuum pump. The rotors 3, 4, are driven in rotation by a motor 8 of the vacuum pump 1. The vacuum pump 1 may comprise one or more pumping stages T1, T2 connected in series. The vacuum pump 1 is called dry because in operation, the rotors 3, 4, rotate inside pumping chambers of a stator 2 without any mechanical contact between them or with the stator 2, which makes it possible not to use oil in the pumping chambers.The vacuum pump 1 may be a primary vacuum pump that can be started from atmospheric pressure or a Roots vacuum pump (also "Roots Blower" in English), mounted upstream and in series with a primary vacuum pump.

[0047] [Fig.2] illustrates such a volumetric vacuum pump 1, in particular a multi-stage vacuum pump 1, here with two pumping stages T1, T2.

[0048] The vacuum pump 1 comprises two Roots rotors 3, 4, here with three lobes as visible in [Fig.3], configured to rotate in opposite directions in the pumping chambers of the pumping stages T1, T2 of a body 5 of the stator 2.

[0049] The successive pumping stages T1-T2 are fluidically connected in series one after the other by respective inter-stage channels 6 arranged in the body 5 of the stator 2 and fluidically connecting the outlet of the preceding pumping stage to the inlet of the following pumping stage. The axial dimensions of the rotors 3, 4 and of the pumping chambers (and therefore the flow rates generated), are for example equal or decreasing with the pumping stages. The pumping stage T1, the inlet of which communicates with a suction orifice of the vacuum pump 1, receives the rotors 3, 4 of larger axial dimension and has the largest flow rate generated. The outlet of the last pumping stage T2 communicates with the discharge port of the vacuum pump 1. During rotation, the gas sucked from the inlet is trapped in the volume generated by the rotors 3, 4 and the body 5 of the stator 2, then is driven by the rotors 3, 4 towards the next stage.

[0050] The rotors 3, 4 are synchronized in rotation by a synchronization device 7. The synchronization device 7 comprises a gear, a toothed wheel being mounted on a respective rotor 3, 4.

[0051] The rotors 3, 4 are driven in rotation by the motor 8. More precisely here, the rotor of the motor 8 is integral in rotation with the driving rotor 3.

[0052] The vacuum pump 1 comprises mechanical bearings 9, for example comprising rolling bearings, to guide the rotation of the rotors 3, 4. There is for example at least one bearing 9 per rotor 3, 4 on either side of the pumping chambers of the pumping stages T1, T2 of the body 5 of the stator 2. These bearings 9 are arranged in flanges 10 of the stator 2 fixed on either side of the body 5 of stator 2.

[0053] The vacuum pump 1 further comprises here a hydraulic cooling circuit 11 for the stator 2 and more particularly here, for the end casing 12 of the stator 2 housing the motor 8, the flanges 10 of the stator 2 in which the bearings 9 of the vacuum pump 1 are arranged and the end casing 13 housing the synchronization device 7. This hydraulic cooling circuit 11 comprises for example a coil in which a heat transfer fluid circulates, such as water at ambient temperature. The coil may be partly arranged in the casing 12 of the stator 2 receiving the motor 8 and partly arranged in the casing 13 receiving the synchronization device 7, the casings 12, 13 being fixed to a respective flange 10 of the stator 2. The coil may be in external thermal contact with the flanges 10 of the stator 2.The hydraulic cooling circuit 11 may include a valve or a mass flow controller, the control of which allows the circulation of the heat transfer fluid in the coil to be controlled and therefore the cooling to be controlled.

[0054] The various elements of the stator 2, in particular the casings 12, 13, the flanges 10 and the elements of the body 5 such as slices and / or half-shells forming the pumping stages T1, T2, are fixed together by screws and sealed together via sealing devices of the vacuum pump 1.

[0055] The vacuum pump 1 may comprise an electrical heating circuit 18, in particular for the stator 2 ([Fig. 3]). The electrical heating circuit 18 may comprise resistive heating elements, such as electrical resistors arranged in metal blocks in contact with the stator 2, in particular with the body 5 of the stator 2 in which the pumping chambers of the pumping stages receiving the rotors 3, 4 are formed.

[0056] The vacuum pump 1 may comprise a lubrication circuit 14 for the bearings 9 and the synchronization device 7, fluidly communicating with a reserve of liquid lubricant, such as oil, and at least one lubricant deflector 15 mounted on a rotor 3, 4. The vacuum pump 1 comprises, for example, a deflector 15 on each rotor 3, 4, a first deflector 15 being mounted on the driving rotor 3, between the motor 8 and a bearing 9, and a second deflector 15 being mounted at an axial end of the rotor. 4 driven, opposite motor 8.

[0057] The vacuum pump 1 may comprise a purge circuit, configured to inject a purge gas, such as nitrogen, into the flow path of the pumped gases to dilute them. The purge circuit may comprise a valve or a mass flow controller, the control of which allows the injected purge gas to be controlled.

[0058] The vacuum pump 1 may comprise at least one physical sensor, in particular at least one temperature sensor 16, 17 of the stator 2. The vacuum pump 1 comprises, for example, two temperature sensors 16, 17 configured to measure the temperature of each of the two flanges 10 of the stator 2 carrying the bearings 9. These physical sensors are, for example, produced by thermocouples screwed into the flanges 10 of the stator 2. A first temperature sensor 16 may be fixed to the flange 10 located on the side of the discharge orifice of the vacuum pump 1, where the partial pressures of the gases are the highest and the risks of deposition of reaction by-products are the greatest. A second temperature sensor 17 may be fixed to the flange 10 located on the side of the suction orifice of the vacuum pump 1 where the partial pressures of the gases are the lowest.

[0059] The vacuum pump 1 may comprise an on-board control unit, such as a computer or an electronic card, comprising one or more controllers or microcontrollers or processors and a memory, and a computer program comprising instructions which, when the program is executed by a computer, cause the latter to implement the steps of a control method 100 of the actual vacuum pump 1.

[0060] This control unit may be the one configured to execute sequences of program instructions allowing the control of the vacuum pump 1, in particular the control of the rotation speed of the at least one rotor 3, 4 and / or the one allowing the reception and supply of operating information from the vacuum pump 1, such as input and output data from a user interface, such as a temperature setpoint.

[0061] Alternatively, the control unit may be remote from the vacuum pump 1 such as in “cloud computing” or “edge computing” in English.

[0062] What has just been described concerns a real (or physical) vacuum pump 1, that is to say one which exists.

[0063] The control method 100 of the actual vacuum pump 1 comprises the following steps:

[0064] - step 101: we simulate in real time, the operation of the real vacuum pump 1 by virtually operating a dynamic digital representation of the actual vacuum pump 1 under operating conditions of the actual vacuum pump 1, in order to obtain a virtual vacuum pump, in particular called a twin digital of the vacuum pump 1, at least for a physical output quantity, representative of the operation of the real vacuum pump 1,

[0065] - step 102: at least one estimated value of the physical quantity of output at a specific location of the virtual vacuum pump,

[0066] - step 103: we use at least one estimated value of the physical quantity of output determined as an input signal of a control law or a correspondence table of which an output data allows the control of a physical element of the real vacuum pump 1 and / or for the emission of a signal representative of an operating state of the real vacuum pump 1.

[0067] In a manner known per se, a digital twin is a dynamic digital representation which faithfully reconstructs an object and its operation in real time, here the real vacuum pump 1.

[0068] The digital twin is a virtual representation of the actual vacuum pump 1 that covers its life cycle. It is updated from real-time input temporal parameters and uses simulation, machine learning, and reasoning to replicate the various processes of a virtual environment. The digital twin is a digital simulation model that updates and changes as the physical counterpart changes.

[0069] The virtual vacuum pump is synchronized with the real vacuum pump 1 by at least one input time parameter of the real vacuum pump 1, capable of varying over time and originating from at least one physical sensor 16, 17 and / or a control instruction of a physical element, the values of the at least one input time parameter of the real vacuum pump 1 being imposed on the virtual vacuum pump.

[0070] The at least one input time parameter makes it possible to readjust the digital twin to reality and thus to dynamically guarantee the adequacy between the real operation of the real vacuum pump 1 and its virtual model. The input time parameters are updated in real time in the digital twin, that is to say almost instantaneously, or at a frequency at least less than every second.

[0071] The digital twin provides access at output to information on a physical temporal quantity in real time, at any point of the virtual vacuum pump, in the inter-stage channels, the pumping chambers, etc. There is thus an exchange of data between the real vacuum pump 1 and the digital twin, in both directions to improve the control of the real vacuum pump 1, in particular to optimize the settings or to decide on the need for maintenance intervention.

[0072] A definition of a digital twin can be taken from the “Digital Twin Consortium” (in English): “a digital twin is a virtual representation of real-world entities and processes, synchronized in real time and a specified fidelity”. Fidelity is the degree of precision and accuracy of the virtual representation and the synchronization mechanism. The degree of refinement of the simulation for each component of the real vacuum pump 1 is adapted according to its impact on the physical output quantity, on the desired precision and on the calculation time. It depends on the precision of the model, on the dispersion of behavior of the real vacuum pumps 1 linked to manufacturing tolerances.

[0073] According to an exemplary embodiment, the dynamic digital representation of the real vacuum pump 1 comprises at least the virtual replica of the three-dimensional geometry of the physical elements of the real vacuum pump 1, in particular the stator 2 (in particular the casing 12, the flanges 10 and the body 5) and the at least one rotor 3, 4, at least one element of the at least one mechanical or electromagnetic bearing 9 and at least one element of the motor 8, the hydraulic cooling circuit 11 and / or the possible electrical heating circuit, the lubrication circuit 13 and the possible deflectors 15, the possible purge circuit, the synchronization device 7 of the rotors 3, 4 if applicable, possibly seals and screws.

[0074] According to an exemplary embodiment, the dynamic digital representation of the real vacuum pump 1 comprises at least the virtual replica of the nature of the materials of the physical elements of the vacuum pump 1, bodies and possible coatings, in particular of the stator 2 and of the at least one rotor 3, 4, of at least one element of the at least one mechanical or electromagnetic bearing 9 and of at least one element of the motor 8, of at least one element of the hydraulic cooling circuit 11 and / or of the electric heating circuit 18, of at least one element of the lubrication circuit 14, of at least one element of the purge circuit, of at least one element of the synchronization device 7, possibly seals and screws.

[0075] Regarding the virtual replica of the geometry and the nature of the materials of the physical elements of the real vacuum pump 1, the virtual vacuum pump (or digital twin) can use CAD plans and data of the real vacuum pump 1.

[0076] Concerning the determination of the temporal evolutions of the physical quantities representative of the operation of the real vacuum pump 1, the virtual vacuum pump (or digital twin) can use, on the one hand, physical models such as chemical reactions and / or physics of fluids and materials, such as laws of thermodynamics, and / or mathematics and / or statistics and / or empirical and / or resulting from data mining and / or artificial intelligence and / or machine learning and / or databases and / or one or more laws or control tables and / or, on the other hand, the values of the input temporal parameters of the real vacuum pump 1.

[0077] According to an exemplary embodiment, the digital twin of the real vacuum pump is a dynamic digital model of fluid mechanics and / or thermal and / or structural mechanics and / or electromagnetic, solved with numerical methods such as finite elements or finite volumes. This model is rendered in real time using dynamic model order reduction techniques. This model order reduction can be done using learning tools using mathematical algorithms, such as neural networks or artificial intelligence such as machine learning, or such as statistical methods.

[0078] The input time parameters which feed the digital twin in real time, can come from physical sensors or can be control instructions for physical elements, for example controlled by the real vacuum pump 1.

[0079] The input temporal parameters from physical sensors or control instructions vary over time because they are modified by their environment, by a machine or by an operator. Their temporal variation impacts the physical quantities of the digital twin to be simulated.

[0080] The physical sensors such as temperature or pressure sensors and the physical elements controlled to the setpoints such as gas mass flow controllers, may be those of the actual vacuum pump 1, those of the enclosure of the equipment fluidly connected to the actual vacuum pump 1 or those of other physical elements forming the vacuum line fluidly connected to the actual vacuum pump 1.

[0081] An input time parameter is for example a temperature measurement of the stator 2 from a temperature sensor 16, 17 on board the actual vacuum pump 1.

[0082] An input time parameter is for example a gas temperature measurement from a temperature sensor arranged on the suction port side of the actual vacuum pump 1.

[0083] An input time parameter is for example a pressure measurement from a pressure sensor. The pressure sensor is for example configured to measure the gas pressure at the suction port of the actual vacuum pump 1 or to measure the pressure in the vacuum installation, i.e. in the enclosure of the equipment fluidically connected to the actual vacuum pump 1 or in other physical elements forming the vacuum line fluidically connected to the actual vacuum pump 1.

[0084] An input time parameter is for example a control setpoint of a mass flow controller of a gas. This parameter is for example from a mass flow controller of a gas to be injected into an enclosure fluidically connected to the actual vacuum pump 1 or from a purge gas of a purge circuit of the actual vacuum pump 1 or injected into the vacuum line fluidically connected to the real vacuum pump 1. This input time parameter provides information on both the nature and the mass flow rate of the gas.

[0085] An input time parameter is for example a recipe of equipment of the enclosure fluidically connected to the real vacuum pump 1, informing of the nature, the flow rates and the partial pressures of the gases injected into the enclosure.

[0086] An input time parameter is for example a control instruction for a valve or a mass flow controller, such as a valve or a mass flow controller of the hydraulic cooling circuit 11 controlling the circulation of the heat transfer fluid or such as an isolation valve of the vacuum installation, or an electrical supply instruction for a resistive heating element of the electrical heating circuit 18 or an element of the ventilation system.

[0087] Another input time parameter may be the pressure and / or the temperature of the heat transfer fluid of the hydraulic cooling circuit 11 from a physical sensor of the hydraulic cooling circuit 11 of the actual vacuum pump 1. Indeed, this may vary over time due to variations in the water distribution network.

[0088] An input time parameter is for example the current consumed by the motor 8 and / or the rotation speed of the at least one rotor 3, 4, coming from a speed variator of the motor 8 of the actual vacuum pump 1.

[0089] An input time parameter is for example a measurement of the deposition layer of reaction products from a deposition sensor at a given location.

[0090] The virtual vacuum pump (or digital twin) can be synchronized with the actual vacuum pump 1 since it was put into operation, upon leaving the factory so that it also understands the process that the actual vacuum pump 1 has gone through, i.e. its history.

[0091] The operating conditions of the actual vacuum pump 1 may comprise, on the one hand, the input time parameters and, on the other hand, input data which do not vary over time. The input data may be a control setpoint of a mass flow controller of a gas, such as the purge gas and / or the pressure and / or the temperature of the heat transfer fluid of the hydraulic cooling circuit 11 for example if they do not change over time. The operating conditions of the actual vacuum pump 1 comprise, for example, at least one temperature control setpoint of the stator 2 and a rotation speed of the rotor 3.

[0092] A determined physical output quantity of the virtual vacuum pump may be the temperature of an element of the virtual vacuum pump and / or the temperature of at least one fluid flowing through the virtual vacuum pump, such as the temperature of at least one gas to be pumped by the virtual vacuum pump and / or of the cooling fluid flowing through the hydraulic cooling circuit 11 of the virtual vacuum pump and / or the lubricating fluid flowing through the lubrication circuit 13 of the virtual vacuum pump and / or the purge fluid flowing through the purge circuit of the virtual vacuum pump.

[0093] A determined physical output quantity of the virtual vacuum pump may be at least one partial pressure of at least one fluid flowing through the virtual vacuum pump, in particular of at least one gas to be pumped by the virtual vacuum pump and / or of the purge fluid flowing through the purge circuit of the virtual vacuum pump and / or of the cooling fluid flowing through the hydraulic cooling circuit 11 of the virtual vacuum pump and / or of the lubricating fluid flowing through the lubrication circuit 13 of the virtual vacuum pump.

[0094] A determined physical output quantity of the virtual vacuum pump may be a functional clearance of the virtual vacuum pump between the at least one rotor and the stator and / or between the rotors of the virtual vacuum pump.

[0095] A determined physical output quantity of the virtual vacuum pump may be a power or a current consumed by the motor and / or a rotation speed of the at least one rotor.

[0096] It is possible to display a representation, for example in two dimensions or in three dimensions, of at least one physical quantity of output of the virtual vacuum pump, for example in colors or in grayscale. It is thus possible for example to visualize a simulation of the evolution of the internal thermal mapping of the real vacuum pump 1 in real time.

[0097] For example, [Fig.4] shows a two-dimensional representation of the temperature of the virtual vacuum pump, the dark parts showing the hottest temperatures. We find the elements of the real vacuum pump 1 of [Fig.2]. We understand that the rotors 3, 4 of the real vacuum pump 1 have a high and uniform temperature inside the pumping chambers. We also note that the flanges 10 of the stator 2 receiving the bearings 9 and the motor 8 are correctly cooled.

[0098] This representation of the temperature of the virtual vacuum pump evolves in real time, as the virtual vacuum pump is synchronized with the real vacuum pump 1.

[0099] [Fig.5] shows a two-dimensional representation of the estimated value of the partial pressure of a gas pumped by the virtual vacuum pump, the dark parts showing the highest pressures. We find the elements of the real vacuum pump 1 of [Fig.2]. We understand that at the discharge of the pumping chamber, the gas pressure is higher than at the intake, this is due to the compression of the gases.

[0100] [Fig.6] shows a two-dimensional representation of the estimated value of the temperature of the gases pumped by the virtual vacuum pump. We understand that at the discharge of the pumping chamber (at the bottom of the figure), the gas is hotter than at the intake (at the top), this is due to the compression of the gases.

[0101] Step 102: at least one estimated value of the physical output quantity is determined at a determined location of the virtual vacuum pump.

[0102] This step makes it possible to create a virtual sensor, i.e. it makes it possible, from the digital twin of a temporal physical quantity, to estimate a new value of the physical quantity which, in general, cannot be measured directly by a physical sensor.

[0103] The frequency at which at least one estimated value of the physical quantity of the digital twin is extracted may be different, in particular lower, than the synchronization frequency of the digital twin which is in real time.

[0104] The estimated values of the physical output quantities can be determined at any point of the virtual vacuum pump, in particular in locations that are difficult or even impossible to access in the real vacuum pump 1, such as in the pumping chambers or in the inter-stage channels 6 or at the location of the bearings 9 or the rotors 3, 4.

[0105] Step 103: the at least one estimated value of the determined physical output quantity is used as an input signal of a control law or of a correspondence table, an output data item of which allows the control of a physical element of the real vacuum pump 1 and / or for the emission of a signal representative of an operating state of the real vacuum pump 1.

[0106] The controlled physical element of the actual vacuum pump 1 is for example an actuator. The output data is for example an electrical supply of the actuator.

[0107] The actuator is for example that of a valve or a mass flow controller of the hydraulic cooling circuit 11 configured to control the circulation of the heat transfer fluid.

[0108] The actuator is for example that of a valve or a mass flow controller of the purge circuit configured to control the circulation of a purge gas in the flow path of the pumped gases.

[0109] The controlled physical element of the actual vacuum pump 1 is for example a resistive heating element of the electrical heating circuit 18 of the stator 2. The output data is for example an electrical power supply of the heating element 18 or the control of a relay or a switch allowing the heating element to be powered.

[0110] The controlled physical element of the actual vacuum pump 1 is for example an element of the ventilation system, such as a fan. The output data is for example a power supply of the element of the ventilation system or the control of a relay or switch providing power to the ventilation system element.

[0111] The controlled physical element of the actual vacuum pump 1 is for example the speed controller. The output data is for example a rotation speed command or a current limitation sent to the speed controller.

[0112] The controlled physical element of the actual vacuum pump 1 is for example controlled so as to lower the energy consumption of the actual vacuum pump 1, in particular the electrical consumption and / or the consumption of cooling fluid and / or purge fluid.

[0113] It is also possible to determine a value of the physical quantity of the virtual vacuum pump for a future date, by considering that the value of the at least one input time parameter is fixed in time or varies according to a predetermined time evolution. It is thus possible to predict, in particular a few hours in advance, a value of the physical quantity of the digital twin.

[0114] In this case, the controlled physical element of the real vacuum pump 1 can be controlled so as to carry out a corrective action depending on the value of the physical quantity of the virtual vacuum pump for a future date.

[0115] For example, in the case where the value of the physical quantity determined for a future date predicts a malfunction or a risk of malfunction or unsuitable operating conditions of the actual vacuum pump 1, the controlled physical element of the actual vacuum pump 1 can be controlled so as to carry out a corrective action with the aim of preserving the integrity of the actual vacuum pump 1 and / or maintaining it in operational operating conditions, for example by controlling the actuators of the purge circuit and / or the hydraulic cooling circuit 11, for example to reduce the risks of condensation or chemical reactions or to limit energy consumption.

[0116] According to an exemplary embodiment, the determined physical output quantity of the virtual vacuum pump is the temperature of the walls of the pumping chambers and / or of the inter-stage channels and / or of the rotors and / or the temperature of the gases pumped into the pumping chambers and / or the temperature of a component of the vacuum pump, such as bearings.

[0117] For example, the estimated value of the temperature of the walls of the pumping chambers, inside the pumping chambers of the stator 2 and / or the interstage channels 6 and / or the rotors 3, 4 and / or the estimated value of the temperature of the gases pumped into the pumping chambers, extracted from the virtual vacuum pump, can be used as input signals of a control law whose output data allows the control of a physical element of the real vacuum pump 1, such as the control of an actuator of a valve or of a mass flow controller of the circuit hydraulic cooling 11 and / or the electrical supply of a heating element of the electrical heating circuit 18 and / or of an element of a ventilation system of the actual vacuum pump 1. This regulation makes it possible to better control the internal temperatures in the pumping stages, both of the walls and of the pumped gases.

[0118] Alternatively and / or additionally, the estimated value of the temperature of the walls of the pumping chambers, of the inter-stage channels 6 and / or of the rotors 3, 4 and / or of the gases pumped into the pumping chambers, extracted from the virtual vacuum pump, can be used for the emission of a signal representative of an operating state of the real vacuum pump 1.

[0119] For this, it is possible to compare an estimated value of the temperature of the walls of the pumping chambers, of inter-stage channels 6 and / or of the rotors 3, 4 extracted from the virtual vacuum pump with thresholds, and / or the estimated value of the gases pumped in the pumping stages extracted from the virtual vacuum pump with a threshold value and, depending on the result of the comparison, emit a signal representative of an operating state of the real vacuum pump 1, in particular a warning signal, for example if the walls of the pumping chambers of the stator 2 have zones that are too cold, risking the formation of reaction products.

[0120] It is also possible to extract an additional physical quantity from the virtual vacuum pump such as the partial pressure of at least one gas for example, inside the pumping chambers of the stator 2 or the inter-stage channels 6, in addition to the temperature of the walls or the gases, to better define the risks of chemical reactions and / or condensation and / or deposits of reaction by-products.

[0121] Thus, the thermal regulation of the real vacuum pump 1 or of the fluids flowing through it is controlled directly from the most relevant temperature values, in particular to reduce the risks of condensation or chemical reactions in the pumping stages. This optimization of the thermal management can make it possible to increase the service life of the real vacuum pump 1.

[0122] According to another example, the estimated value of the temperature of the bearings 9 of the vacuum pump 1, determined from the virtual vacuum pump, can be compared to thresholds and, depending on the result of the comparison, an alert signal can be issued, for example if the temperature of the bearings 9 exceeds thresholds that are detrimental to their lifespan.

[0123] According to another exemplary embodiment, a determined physical output quantity of the virtual vacuum pump is a functional clearance J1, J2, J3 between the at least rotor 3, 4 and the stator 2 and / or between the rotors 3, 4.

[0124] In particular and as illustrated in Figures 2 and 3, the estimated values of the functional clearances J1, J2, J3 can be the axial functional clearance J1, between the body 5 of the stator 2 and the rotors 3, 4 in the axial direction, the radial functional clearance J2, between the body 5 of the stator 2 and the rotors 3, 4 in the radial direction and the functional clearance J3 between the rotors 3, 4.

[0125] The estimated values of the functional clearances J1, J2, J3 extracted from the digital twin can be used for the emission of a signal representative of an operating state of the real vacuum pump 1, in particular an alert or an alarm in particular if the estimated values of the functional clearances J1, J2, J3 are lower than alert thresholds, so that an operator can decide to isolate the real vacuum pump 1 from the enclosure for example with a view to a maintenance intervention.

[0126] The estimated values of the functional games J1, J2, J3 extracted from the digital twin can be used as input signals of a control law or of a correspondence table of which an output data allows the control of a physical element of the real vacuum pump 1, in particular to deduce a corrective action to be carried out.

[0127] For example, the estimated values of the functional clearances J1, J2, J3 extracted from the digital twin can be used as input signals of a control law whose output data allows the control of an actuator of a valve or of a mass flow controller of the hydraulic cooling circuit 11 and / or the electrical supply of a heating element of the electrical heating circuit 18 and / or of an element of a ventilation system of the real vacuum pump 1, in particular if the estimated values of the functional clearances J1, J2, J3 extracted from the digital twin are lower than alert thresholds, for example so as to widen the functional clearances by heating the body 5 of the stator 2 to expand it.

[0128] This control method 1 applies to any type of real vacuum pump 1.

[0129] Figures 7 and 8 thus illustrate another example for a turbocharged vacuum pump 1- lecular.

[0130] The turbomolecular vacuum pump 1 comprises a stator 2 in which a rotor 3 is configured to rotate at high speed in axial rotation, for example a rotation at more than twenty thousand revolutions per minute.

[0131] The vacuum pump 1 therefore only has a single rotor 3 and does not have a synchronization device or lubrication circuit.

[0132] In operation, the discharge port of the turbomolecular vacuum pump 1 is connected to a primary pump.

[0133] [Fig.7] illustrates an exemplary embodiment of a turbomolecular vacuum pump 1.

[0134] In this embodiment, the turbomolecular vacuum pump 1 is said to be hybrid: it comprises a turbomolecular stage 20 and a molecular stage 21 located downstream of the turbomolecular stage 20 in the direction of circulation of the pumped gases (represented by the arrows Fl in [Fig.7]). The pumped gases enter through the orifice suction 22, first pass through the turbomolecular stage 20, then the molecular stage 21, to then be evacuated towards a discharge orifice of the turbomolecular vacuum pump 1.

[0135] In the turbomolecular stage 20, the rotor 3 comprises at least two stages of blades 23 and the stator 2 comprises at least one stage of fins 24. The stages of blades 23 and fins 24 follow one another axially along the axis of rotation II of the rotor 3. The rotor 3 comprises, for example, more than four stages of blades 23, such as between four and twelve stages of blades 23 (seven in the example illustrated).

[0136] Each stage of blades 23 of the rotor 3 comprises inclined blades which extend in a substantially radial direction from a hub of the rotor 3 fixed to a drive shaft 25 of the vacuum pump 1. The blades are distributed regularly around the periphery of the hub.

[0137] Each stage of fins 24 of the stator 2 comprises a crown from which extend, in a substantially radial direction, inclined fins, distributed regularly around the inner periphery of the crown. The fins of a stage of fins 24 of the stator 2 engage between the blades of two successive stages of blades 23 of the rotor 3. The blades 23 of the rotor 3 and the fins 24 of the stator 2 are inclined to guide the pumped gas molecules towards the molecular stage 21.

[0138] Here, in the molecular stage 21, the rotor 3 further comprises a skirt 26, called a Holweck skirt, downstream of the at least two blade stages 23, formed by a smooth cylinder, which rotates opposite helical grooves 27 of the stator 2. The helical grooves 27 are arranged one above the other. There are for example between three and ten helical grooves 14, such as six. The helical grooves 14 of the stator 2 make it possible to compress and guide the pumped gases towards the discharge orifice.

[0139] The rotor 3 further comprises an internal bowl, coaxial with the axis of rotation II, formed under the skirt 26 and arranged opposite a bell 28 of the stator 2, projecting under the rotor 3. In operation, the rotor 3 rotates in the stator 2 without contact between the internal bowl and the bell 28.

[0140] The rotor 3 is driven in rotation in the stator 2 by a motor 8 of the vacuum pump 1. The motor 8 is for example arranged in the bell 28 of the stator 2, itself arranged under the internal bowl of the rotor 3, the drive shaft 25 passing through the bell 28 of the stator 2.

[0141] The rotor 3 is guided laterally and axially by magnetic or mechanical bearings 9 supporting the drive shaft 12 of the rotor 3, located in the stator 2. There are for example first bearings 9 supporting and guiding a first end of the drive shaft 25 in a base of the bell 28 of the stator 2 and second bearings 9 supporting and guiding a second end of the drive shaft 25 arranged at the top of the bell 28.

[0142] Other electrical or electronic components may be received in the bell. 28 of stator 2, as position sensors.

[0143] The vacuum pump 1 may comprise a cooling device configured to cool the bell 28, arranged for example in the bell 28 or in thermal contact with the bell 28, such as a hydraulic cooling circuit, in order to be able to continuously cool the elements that it contains such as in particular the bearings 9, the motor 8 and other electrical or electronic components to enable their operation.

[0144] The vacuum pump 1 may comprise a purge device 30 configured to inject a purge gas into the gap located between the bell 28 of the stator 2 and the internal bowl of the rotor 3. The purge device 30 is for example configured to inject a purge gas at the level of at least one bearing 9 located in the stator 2, supporting and guiding the drive shaft 25 of the rotor 3 so that the flow of purge gas passes through the at least one bearing 9 before exiting the bell 28 of the stator 2 and circulating in the gap. The circulation of the purge gas is shown diagrammatically by arrows f2 in [Fig.l].

[0145] The vacuum pump 1 may comprise an internal heating device 31 arranged in the gas flow path of the vacuum pump 1 and configured to heat the rotor 3.

[0146] The internal heating device 31 may comprise radiative elements, for example arranged in the helical grooves 27 of a sleeve 32 of the stator 2 of the vacuum pump 1. The internal radiative heating device 31 has the advantage of having a short response time, so that the heating can be switched off in less than one minute after the stop command.

[0147] The turbomolecular vacuum pump 1 may further comprise a temperature sensor 33 configured to measure the temperature of the rotor 3. The temperature sensor 33 is for example an infrared temperature sensor. The infrared sensor is contactless, which makes it possible to measure the temperature of the rotating rotor 3 with great precision in the temperature ranges between 50°C and 250°C.

[0148] The temperature sensor 33 can be configured to measure the temperature of the skirt 26 of the rotor 3 (the cylindrical part), in particular in a lower part, that is to say located on the side of the discharge orifice of the vacuum pump 1, so as to target the place of the rotor 3 which is subjected to the most mechanical stress.

[0149] The temperature sensor 33 is for example arranged behind (under) the skirt 26 of the rotor 3, between the stator 2 and the internal bowl of the rotor 3 ([Fig.l]). In this way, the temperature sensor 33 is not arranged in the gas pumping path and therefore is little subject to corrosive attacks from the pumped gases and can benefit from protection by the purge gas.

[0150] The vacuum pump 1 may also comprise an external heating device configured to heat the stator 2 of the vacuum pump 1. The external heating device is for example configured to heat an external casing 34 of the stator 2 of the vacuum pump 1. Alternatively or in addition, the external heating device may be configured to heat the stator 2 at the discharge of the vacuum pump 1, in particular around the discharge orifice. The external heating device comprises for example one or more heating resistive belts or one or more heating cartridges, the electrical power supply of which may be controlled by a control unit. The heating may in particular be controlled around a set temperature by means of a temperature sensor configured to measure the temperature of the stator 2.

[0151] As in the first embodiment, the operation of the real vacuum pump 1 is simulated in real time by virtually operating a dynamic digital representation of the real vacuum pump 1 under operating conditions of the real vacuum pump 1, in particular at least for a temperature control setpoint of the stator 2 and for a rotation speed of the rotor 3, in order to obtain a virtual vacuum pump, in particular called a digital twin of the vacuum pump 1, at least for a physical output quantity, representative of the operation of the real vacuum pump 1, at least one estimated value of the physical output quantity is determined at a determined location of the virtual vacuum pump,the at least one estimated value of the determined output physical quantity is used as an input signal of a control law or a correspondence table, an output data item of which allows the control of a physical element of the real vacuum pump 1 and / or for the emission of a signal representative of an operating state of the real vacuum pump 1, the virtual vacuum pump being synchronized with the real vacuum pump 1 by at least one input time parameter of the real vacuum pump 1, capable of varying over time and originating from at least one physical sensor 33, such as a temperature sensor and / or a position sensor, and / or a control instruction of a physical element, the values of the at least one input time parameter of the real vacuum pump 1 being imposed on the virtual vacuum pump.

[0152] [Fig.8] shows a two-dimensional representation of the temperature of the elements of the virtual vacuum pump, the dark parts showing the hottest temperatures. We find the elements forming the real vacuum pump 1 of [Fig.7]. We understand that the rotor 3 of the real vacuum pump 1 has a high and uniform temperature.

Claims

Claims

1. Method for controlling (100) a real vacuum pump (1) comprising a stator (2), at least one rotor (3, 4), at least one mechanical or electromagnetic bearing (9) for guiding the rotation of the at least one rotor (3, 4), a motor (8) configured to drive the at least one rotor (3, 4), characterized in that said control method (100) comprises the following steps: - the operation of the real vacuum pump (1) is simulated in real time by virtually operating a dynamic digital representation of the real vacuum pump (1) under operating conditions of the real vacuum pump (1), in order to obtain a virtual vacuum pump, in particular called a digital twin of the vacuum pump (1), at least for a physical output quantity, representative of the operation of the real vacuum pump (1), - at least one estimated value of the physical output quantity is determined at a determined location of the virtual vacuum pump,- the at least one estimated value of the determined physical output quantity is used as an input signal of a control law or a correspondence table, an output data item of which allows the control of a physical element of the real vacuum pump (1) and / or for the emission of a signal representative of an operating state of the real vacuum pump (1), - the virtual vacuum pump being synchronized with the real vacuum pump (1) by at least one input time parameter of the real vacuum pump (1), capable of varying over time and originating from at least one physical sensor (16, 17; 33) and / or a control instruction of a physical element, the values of the at least one input time parameter of the real vacuum pump (1) being imposed on the virtual vacuum pump.,

2. Control method (100) according to the preceding claim, characterized in that the dynamic digital representation of the real vacuum pump (1) comprises at least the virtual replica of the three-dimensional geometry of the physical elements of the real vacuum pump (1), in particular of the stator (2) and of the at least one rotor (3, 4), of at least one element of the at least one mechanical or electromagnetic bearing (9) and of at least one element of the motor (8).

3. Control method (100) according to one of the preceding claims, characterized in that the dynamic digital representation of the real vacuum pump (1) comprises at least the virtual replica of the nature of the materials of the physical elements of the vacuum pump (1), in particular of the stator (2) and of the at least one rotor (3, 4), of at least one element of the at least one mechanical or electromagnetic bearing (9) and of at least one element of the motor (8).

4. Control method (100) according to one of the preceding claims, characterized in that at least one input time parameter is chosen from: - a temperature measurement of the stator (2) from a temperature sensor (16, 17;33), - a control instruction from a gas mass flow controller, - a pressure measurement from a pressure sensor, - a recipe from equipment in an enclosure fluidically connected to the vacuum pump (1), - a control instruction from a valve, such as a valve in a hydraulic cooling circuit (11) of the actual vacuum pump (1), - an electrical supply instruction from a resistive heating element in an electrical heating circuit (18) or an element of the ventilation system of the actual vacuum pump (1), - a current consumed by the motor (8), - the rotation speed of the at least one rotor (3, 4), from a speed variator of the motor (8) of the actual vacuum pump (1), - a gas temperature measurement from a temperature sensor arranged on the side of a suction port of the actual vacuum pump (1).;

5. Control method (100) according to one of the preceding claims, characterized in that a determined physical output quantity of the virtual vacuum pump is the temperature of an element of the virtual vacuum pump and / or the temperature of at least one fluid flowing through the virtual vacuum pump, in particular of at least one gas to be pumped by the virtual vacuum pump and / or of a purge fluid flowing through a purge circuit of the virtual vacuum pump and / or of a cooling fluid flowing through a hydraulic cooling circuit (11) of the virtual vacuum pump and / or of a lubricating fluid flowing through a lubrication circuit (13) of the virtual vacuum pump.

6. Control method (100) according to one of the preceding claims, characterized in that a determined physical output quantity of the virtual vacuum pump is at least one partial pressure of at least one fluid flowing through the virtual vacuum pump, in particular at least one gas to be pumped by the virtual vacuum pump and / or a purge fluid flowing through a purge circuit of the virtual vacuum pump and / or a cooling fluid flowing through a hydraulic cooling circuit (11) of the virtual vacuum pump and / or a lubricating fluid flowing through a lubrication circuit (13) of the virtual vacuum pump.

7. Control method (100) according to one of the preceding claims, characterized in that a determined physical output quantity of the virtual vacuum pump is a functional clearance (J1, J2, J3) of the virtual vacuum pump between the at least one rotor (3, 4) and the stator (2) and / or between the rotors (3, 4).

8. Control method (100) according to one of the preceding claims, characterized in that a determined physical output quantity of the virtual vacuum pump is a power or a current consumed by the motor (8) and / or a rotational speed of the at least one rotor (3, 4).

9. Control method (100) according to one of the preceding claims, characterized in that the at least one estimated value of the physical output quantity is determined at a location in a pumping chamber of the virtual vacuum pump, such as at the walls of the pumping chambers or at least one rotor (3, 4) or the interior volume of the pumping chambers, or in an interstage channel (6) of the virtual vacuum pump or at least one bearing (9) of the virtual vacuum pump.

10. Control method (100) according to one of the preceding claims, for which the controlled physical element of the actual vacuum pump (1) is an actuator of a valve or a mass flow controller of a hydraulic cooling circuit (11) of the actual vacuum pump (1) or the actuator of a valve or a mass flow controller of a purge circuit of the actual vacuum pump (1) configured to inject a purge gas into the flow path of the pumped gases or a resistive heating element of an electric heating circuit (18) of the stator (2) of the actual vacuum pump (1), or an element of a ventilation system of the actual vacuum pump (1) or a speed variator of the actual vacuum pump (1).

11. Control method (100) according to one of the preceding claims, for which the controlled physical element of the actual vacuum pump (1) is controlled so as to lower the energy consumption of the real vacuum pump (1).

12. Control method (100) according to one of the preceding claims, for which a value of the physical quantity of the virtual vacuum pump is determined for a future date, considering that the value of the at least one input temporal parameter is fixed in time or varies according to a predetermined temporal evolution.

13. Control method (100) according to the preceding claim, for which the controlled physical element of the real vacuum pump (1) is controlled so as to carry out a corrective action depending on the value of the physical quantity of the virtual vacuum pump for a future date.

14. Control method (100) according to one of the preceding claims, characterized in that a representation of at least one physical output quantity of the virtual vacuum pump is displayed.

15. Real vacuum pump (1) comprising a stator (2) and at least one rotor (3, 4), at least one mechanical or electromagnetic bearing (9) for guiding the rotation of the at least one rotor (3, 4), a motor (8) configured to drive the at least one rotor (3, 4), characterized in that it comprises a control unit configured to implement a control method (100) according to one of the preceding claims.

16. A computer program comprising instructions which, when the program is executed by a computer, cause the computer to implement the steps of the method for controlling an actual vacuum pump (1) according to one of claims 1 to 14.

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