Abstract: A circuit interruption device including first and second terminals for connection, to a respective electrical circuit or network, a current-conductive branch including first, second, and third current-conductive branch portions successively connected in series between the first and second terminals, the first current-conductive branch portion including a first switching element, the second current-conductive branch portion including a second switching element, the third current-conductive branch portion including a third switching element, each switching element configured to be switchable to selectively permit and block a flow of current in the respective current-conductive branch portion, first and second current bypass paths, the first current bypass path connected across the first and second current-conductive branch portions, the second current bypass path connected across the second and third current-conductive branch portions, and a controller configured to selectively control the switching of the swit

Abstract: A distributed control system includes an electronic control unit to establish secure communication with a distributed control module. Upon determination that a previously negotiated session key is stored on the electronic control unit, the electronic control unit transmits encrypted communications with the distributed control module using the previously negotiated session key, negotiates a new session key with the distributed control module, and stores the new session key. Upon determination that the previously negotiated session key is not stored on the electronic control unit, the electronic control unit negotiates the new session key with the distributed control module. After negotiating the new session key with the distributed control module, the electronic control unit ceases transmission of unencrypted communications with the distributed control module, transmits encrypted communications with the distributed control module using the new session key, and stores the new session key.

Abstract: A gas turbine engine includes a fan located at a forward portion of the gas turbine engine, and a compressor section and a turbine section arranged in serial flow order. The compressor section and the turbine section together define a core airflow path. A rotary member is rotatable with the fan and with a low pressure turbine of the turbine section. The low pressure turbine includes a rotating drum to which a first airfoil structure is connected and extends radially inward toward the rotary member. A torque frame connects the rotating drum to the rotary member and transfers torque from the first airfoil structure mounted to the rotating drum to the rotary member. The torque frame includes an inner disk mounted to the rotary member, an outer ring and a second airfoil structure formed separately from the outer ring and connected thereto by a releasable connecting structure. The second airfoil structure extends radially inward from the outer ring toward the inner disk.

Abstract: A method for initializing an engine control system of an aircraft may include authenticating a boot loader, authenticating a manifest in response to authentication of the boot loader wherein the manifest contains hashes of one or more software components, and in response to authentication of the manifest, loading a first set of software components from among the one or more software components onto a non-transitory computer-readable medium, calculating a hash of each software component of the first set of software components, authenticating the first set of software components by comparing the calculated hash of each software component of the first set of software components to the hash of a corresponding software component in the manifest, and executing the first set of software components in response to authentication of the one or more software components. Devices and systems are also provided for initializing an engine control system of an aircraft.

Abstract: A composite airfoil having a non-metallic leading edge protective wrap is provided. In one aspect, the airfoil has a composite core having a pressure sidewall and a suction sidewall each extending between a core leading edge and a core trailing edge. A leading edge protective wrap protects the core leading edge and includes a trailing wrap and a leading wrap. The trailing wrap wraps around the core leading edge and is connected to the composite core. The leading wrap wraps around the core leading edge and is connected to the trailing wrap. The trailing and leading wraps both have leading edges that are spaced from one another. A filler is positioned between the leading edges of the trailing and leading wraps. A protective nose is connected to the leading edge of the leading wrap. The components of the leading edge protective wrap are formed of non-metallic materials.

Abstract: A system includes one or more debris sensors or particulate sensors are used to sense engine inlet debris or particulate matter which are drawn into the engine during flight, in real-time. The system employs that information, in conjunction with other engine health and module health techniques, to identify which gas-path modules of the aircraft engine may require maintenance or repair. In one embodiment, existing engine health technique may be based on various engine operational parameters for a new engine or an average engine.

Abstract: Systems and methods for mapping trip trajectories include identifying one or more vehicle trips (e.g., aircraft flights). One or more trajectory configurations associated with at least a portion of each vehicle trip can be identified, and location data associated with the one or more vehicle trips can be requested. Trip trajectory data based at least in part from the location data associated with the one or more vehicle trips and the one or more trajectory configurations associated with at least a portion of each vehicle trip can be generated. The trip trajectory data can be provided for display on a map of a geographic area including one or more locations defined by the location data associated with the one or more vehicle trips.

Abstract: The disclosure relates to an apparatus and method for liquid cooling of an electronic component. A housing includes an insertion slot and defines at least one component chamber for carrying the electronic component. A fluid inlet and fluid outlet are provided on the housing. A liquid coolant circuit passes through the housing at least from the inlet to the outlet.

Abstract: According to some embodiments, a system may include an additive manufacturing platform that provides additive manufacturing capability data. A customer platform, associated with a customer, may transmit an industrial asset item request for an industrial asset item. A digital transaction engine may receive the additive manufacturing capability data and the industrial asset item request. The digital transaction engine may then associate the industrial asset item request with an industrial asset definition file, and, based on the additive manufacturing capability data and the industrial asset definition file, assign the industrial asset item request to the additive manufacturing platform. The assignment of the industrial asset item request may be recorded via a secure, distributed transaction ledger. Responsive to the assignment, the additive manufacturing platform may create the industrial asset item (e.g., via an additive manufacturing printer) and provide the item to the customer.

Abstract: A coating system configured to be applied to a thermal barrier coating of an article includes an infiltration coating configured to be applied to the thermal barrier coating. The infiltration coating infiltrates at least some pores of the thermal barrier coating. The infiltration coating decomposes within the at least some pores of the thermal barrier coating to coat a portion of the at least some pores of the thermal barrier coating. The infiltration coating reduces a porosity of the thermal barrier coating. The coating system also includes a reactive phase spray formulation coat configured to be applied to the thermal barrier coating. The reactive phase spray formulation coating reacts with dust deposits on the thermal barrier coating.

Abstract: A method of transient control of a thermal transport bus of a turbomachine includes measuring a measured temperature and a measured pressure of a working fluid; determining a selected run state of a turbomachine, wherein the selected run state is one of a plurality of run states; selecting a desired operating condition comprising a desired temperature range and a desired pressure range as a function of a desired state of the working fluid; comparing the measured temperature with the desired temperature range, and comparing the measured pressure with the desired pressure range; and modulating control of the thermal transport bus as a function of the comparing of the measured temperature with the desired temperature range and the comparing of the measured pressure with the desired pressure range.

Abstract: The present disclosure relates to a method, a system, and a storage medium for segmenting a lung image. The method for segmenting a lung image comprises: obtaining medical image data containing a lung region; performing lung lobe segmentation on the medical image data to generate a plurality of lung lobe data subsets; generating updated lung image data based on one or a plurality of lung lobe data subsets in the plurality of lung lobe data subsets; and performing nidus segmentation on the updated lung image data to generate a segmentation image that identifies a pneumonia nidus.

Abstract: A method of automatic configuration of a communications interface of an unknown data network, the method comprising connecting an Electronic Flight Bag (EFB) to the unknown data network, attempting to open communication ports, in response to attempting to open communication ports, receiving data from the unknown data network, determining, by a controller module, if the selected communications interface can interpret the received data, and operating the communications interface of the EFB in accordance with the selected communications interface.

Abstract: Methods and systems are provided for an oxygen sensor included in a medical gas flow device, such as an anesthesia machine. In one embodiment, a method for a medical gas flow device comprises tracking an output voltage of an oxygen sensor during calibration over time, and, responsive to the output voltage decreasing by at least threshold amount from an initial calibration output voltage, estimating an end-of-life date of the oxygen sensor and outputting a replacement notification.

Abstract: Techniques for accurate positioning of an energy application device for neuromodulation treatment protocols are provided. A neuromodulation positioning patch is applied to a patient's skin. The energy application device is coupled to a frame of the neuromodulation positioning patch to position a transducer of the energy application device within an opening at a treatment position within the opening. The frame is also coupled to a removable dock for an imaging probe. When the frame is coupled to the removable dock the frame of the neuromodulation positioning patch, acquires image data through the opening to identify or verify the treatment position.

Abstract: A method for producing a component layer-by-layer includes: providing two or more resin handling assemblies, each including a resin support which has at least a portion which is transparent, each resin support defining a build surface located in a build zone of the respective assembly; executing a build cycle, including: depositing on each build surface radiant-energy-curable resin, the resin on each build surface being a unique material combination; positioning a stage relative to one of the build surfaces to define a layer increment; selectively curing the resin using applied radiant energy so as to define a cross-sectional layer of the component; separating the component from the build surface; cleaning at least one of the component and the stage; and repeating the cycle, for a plurality of layers, wherein at least one of the layers is cured in each of the build zone. Apparatus is described for carrying out the method.

Abstract: The present invention relates to an additive manufacturing system and its methods. The system includes a material conveyor, an energy source, and a micro-forging device. The material conveyor is configured to convey material. The energy source is configured to direct an energy beam toward the material, the energy beam fuses at least a portion of the material to form a solidified portion. The micro-forging device is movable along with the material conveyor for forging the solidified portion, wherein the micro-forging device comprises a first forging hammer and a second forging hammer, the first forging hammer is configured to impact the solidified portion to generate a first deformation, and the second forging hammer is configured to impact the solidified portion to generate a second deformation greater than the first deformation.

Abstract: A fuel system is provided for an aircraft having a fuel source. The fuel system includes a fuel oxygen reduction unit defining a liquid fuel supply path, a stripping gas supply path, a liquid fuel outlet path, and a stripping gas return path, wherein the stripping gas return path is in airflow communication with the fuel source.

Abstract: Techniques are described for improving the efficiency of collaboration session synchronization between applications, particularly applications that consume heavy application data. In an embodiment, a computer-implemented method comprises employing, by an application server operatively coupled to a processor, a context management server to manage synchronization of usage context information between a first client device and one or more second client devices related to simultaneous usage of an application provided by the application server during a collaboration session established between the first client device and the one or more second client devices. The method further comprises managing, by the application server, synchronization and exchange of application data between the first client device and the one or more second client devices during the collaboration session without sharing the application data with the context management server.

Abstract: A method, apparatus, and program for additive manufacturing. In one aspect, the method comprises: forming an at least partially solidified portion within a first scan region (801), wherein the solidified portion within the first scan region (801) is formed by irradiating a build material along a first irradiation path (811). A second portion of a build material may be irradiated along a second irradiation path (813), wherein the second scan region (803) is offset with respect to the first scan region (801) thereby defining an offset region (802). The offset region (802) is at least partially solidified by the first irradiation path (811) and the second irradiation path (813) and a reference line (819) intersects the first irradiation path (811) and the second irradiation path (813) within the offset region (802), wherein the reference line (819) is substantially parallel to a side (810) of the first scan region (801).

Abstract: A forging head for additive manufacturing, comprising a base portion and a forging portion. The forging portion extends from the base portion for forging a cladding layer during formation of the cladding layer by additive manufacturing. The forging head further comprising a through hole which is formed through the base portion and the forging portion, for at least one of an energy bean and an additive material to pass through during formation of the cladding layer.

Abstract: Methods and systems are provided for performing automated measurements on medical images. In one example, a method includes acquiring a first ultrasound image and a second ultrasound image in accordance with a patient exam workflow, wherein the patient exam workflow calls for one or more measurements including a first measurement to be obtained on at least the first ultrasound image, automatically assessing whether the first ultrasound image is suitable for obtaining the first measurement during a time period where the second ultrasound image is being acquired, and if the first ultrasound image is automatically assessed as being unsuitable for obtaining the first measurement, automatically prompting the user, while the second ultrasound image is still being acquired, to reacquire the first ultrasound image.

Abstract: The entropy coding of a current part of a predetermined entropy slice is based on, not only, the respective probability estimations of the predetermined entropy slice as adapted using the previously coded part of the predetermined entropy slice, but also probability estimations as used in the entropy coding of a spatially neighboring, in entropy slice order preceding entropy slice at a neighboring part thereof. Thereby, the probability estimations used in entropy coding are adapted to the actual symbol statistics more closely, thereby lowering the coding efficiency decrease normally caused by lower-delay concepts. Temporal interrelationships are exploited additionally or alternatively.

Abstract: Methods and apparatus to produce hydrogen gas turbine propulsion are disclosed. An example apparatus to produce propulsion in a gas turbine engine includes a fluid line to transport hydrogen from a hydrogen supply and an inert gas from an inert gas supply to a gas turbine combustor. The apparatus also includes at least one heat exchanger coupled to the fluid line to heat the inert gas and the hydrogen in the fluid line.

Abstract: Various embodiments include a turbine blade having an airfoil with a tip shroud having a forwardmost tip rail having one or more pressure side and suction side bevel surfaces and pressure side and suction side scallop surfaces. The surfaces have a nominal profile substantially in accordance Cartesian coordinate values of X, Y and Z set forth in various tables herein. The Cartesian coordinate values are non-dimensional values of from 0% to 100% convertible to distances by multiplying the values by a tip rail length expressed in units of distance. The X, Y and Z values are connected by smooth continuing arcs that are joined smoothly with one another to form the nominal profile that defines the suction side scallop surface, the pressure side scallop surface, the suction side bevel surface, or the pressure side bevel surface.

Abstract: A turbine engine with an outer rotor that circumscribes an inner rotor. The outer rotor includes circumferentially arranged components with a radial outer end and radial inner end. Inner ends of confronting sides of adjacent components include at least one damper element to dampen the relative motion of the components or to provide at least a partial seal between adjacent components.

Abstract: A gas turbine engine having a waste heat recovery system is provided. The gas turbine engine includes a compressor section, a combustion section, a turbine section, and an exhaust section in serial flow order and together defining a core air flowpath, the exhaust section including a primary exhaust flowpath and a waste heat recovery flowpath parallel to the primary exhaust flowpath; and the waste heat recovery system includes a heat source exchanger positioned in thermal communication with a first portion of the waste heat recovery flowpath.

Abstract: A turbomachinery engine can include a fan assembly with a plurality of variable pitch fan blades. The fan blades are configured such that they define a first VPF parameter and a second VPF parameter. The first VPF parameter is within a range of 0.10 to 0.40 and is defined as the hub-to-tip radius ratio divided by the fan pressure ratio. The second VPF parameter is within a range of 1-30 lbf/in2 and is defined as the bearing spanwise force divided by the fan area. In certain examples, the turbomachinery engine further includes a pitch change mechanism, a vane assembly, a core engine, and a gearbox.

Abstract: The present disclosure relates to wind turbine blades (22) configured to receive a peripheral device (250a, 250b, 250c) at a portion of the outer surface (211) of the blade (22), and wherein the wind turbine blade (22) is configured to magnetically couple to the peripheral device (250a, 250b, 250c). The present disclosure also relates to wind turbine blade assemblies (200) and methods (700) to provide the same.

Abstract: A system for measuring displacements of a blade root of a rotor blade of a wind turbine includes a hub, and a rotor blade coupled to the hub by a pitch bearing. The system further comprises a reference plane and at least one displacement sensor. The reference plane is configured to move with the rotor blade as the rotor blade moves relative to the hub while the displacement sensor is fixed to the hub and the displacement sensor is configured to detect a displacement of the reference plane relative to the hub without physical contact. Alternatively, the reference plane has a fixed position with respect to the hub while the displacement sensor is fixed to the rotor blade and the displacement sensor is configured to detect a displacement of the reference plane relative to the rotor blade without physical contact.

Abstract: A mounting tool includes a base component and an attachment means. The base component includes a mounting portion defining an attachment location for receiving and securing a repair tool so as to maintain the repair tool at a desired repair location and a first receiving portion defining a first cavity for receiving a portion of a wind turbine so as to be externally secured to the wind turbine. The attachment means may be adjustably secured to the first receiving portion of the base component and securable to the portion of the wind turbine so as to secure the mounting tool to the wind turbine at the desirable repair location.

Abstract: Systems and techniques that facilitate hybrid unsupervised and supervised image segmentation are provided. In various embodiments, a system can access a computed tomography (CT) image depicting an anatomical structure. In various aspects, the system can generate, via an unsupervised modeling technique, at least one class probability mask of the anatomical structure based on the CT image. In various instances, the system can generate, via a deep-learning model, an image segmentation based on the CT image and based on the at least one class probability mask.

Abstract: A superconducting magnet system having two-stage quenching. A primary coil assembly includes a coil section configured to be superconducting when conducting current below a first critical current. An EMI shielding coil assembly includes a coil section configured to be superconducting when conducting current below a second critical current, which is electrically coupled to a variable resistor configured to be superconducting when conducting current below a third critical current and to be non-superconducting when conducting current at or above the third critical current that is less than both the first and second critical currents. Generating a magnetic flux within the EMI shielding coil assembly causes the current conducted through the variable resistor to exceed the third critical current, quenching the variable resistor and generating heat. The EMI shielding coil assembly is disposed such that the heat from the variable resistor quenches the primary coil assembly.

Abstract: A wireless power transfer system is disclosed. The wireless power transfer system includes a first converting unit configured to convert a first DC voltage of an input power to a first AC voltage. Further, the wireless power transfer system includes a contactless power transfer unit configured to receive the input power having the first AC voltage from the first converting unit and transmit the input power. Also, the wireless power transfer system includes a second converting unit configured to receive the input power from the contactless power transfer unit and convert the first AC voltage of the input power to a second DC voltage. Furthermore, the wireless power transfer system includes a switching unit configured to regulate the second DC voltage across the electric load if the second DC voltage across the electric load is greater than a voltage reference value.

Abstract: A hybrid electric aircraft equipped with gyroscopic stabilization control is provided. In one aspect, a hybrid electric aircraft includes a turbo-generator having a gas turbine engine and an electric generator operatively coupled thereto for generating electrical power. The turbo-generator defines a rotation axis. The aircraft also includes one or more electrically-driven propulsors for producing thrust for the aircraft. In addition, the aircraft includes a pivot mount operatively coupled with the turbo-generator. To provide gyroscopic stabilization control of the aircraft, the pivot mount is controlled to adjust the rotation axis of the turbo-generator relative to a prime stability axis of the aircraft. Additionally or alternatively, a rotational speed of the turbo-generator can be changed to provide gyroscopic stabilization control of the aircraft.

Abstract: Various methods and systems are provided for calibrating a camera-based feature detection system for an x-ray system having a support surface, and a gantry operably connected to the support surface and a light source disposed on the gantry, where the gantry defines a system referential. The x-ray system includes a camera spaced from the gantry and operably connected to a calibration system, the camera defining a camera referential within which the support surface and gantry are positioned. The calibration system registers the camera referential to the system referential by operating the light source to position an indication on the support surface and by obtaining a number of camera images of the indication on the support surface and corresponding indication location in the system referential.

Abstract: An X-ray system with a universal positioning system includes a multiple degree of freedom overhead support system mounted within a location for the X-ray system, a first imaging device on the overhead support system, a multiple degree of freedom wall stand disposed within the location for the X-ray system, the wall stand comprising a motive module and a number of moveable members operably connected to the motive module that can be operated by the motive module to move the wall stand over a floor of the location, a second imaging device mounted to the wall stand, a table disposed within the location for the X-ray system, including a base disposed on the floor of the location and a support surface secured at one end to the base, and a workstation including a processing unit configured to send control signals to and to receive data signals from the universal positioning system.

Abstract: A robotic assembly configured to service an engine, wherein the robotic assembly includes an environmental capture device configured to provide information associated with an environment in which the engine is disposed to one or more computing devices, and wherein the one or more computing devices are configured to use the information to inspect the engine before and after repair operations associated with the service to check for repair equipment, or parts thereof, left in the engine after the repair.

Abstract: A build unit for additively manufacturing three-dimensional objects may include an energy beam system having one or more irradiation devices respectively configured to direct one or more energy beams onto a region of a powder bed, and an inertization system including an irradiation chamber defining an irradiation plenum, one or more supply manifolds, and a return manifold. The one or more supply manifolds may include a downflow manifold configured to provide a downward flow of a process gas through at least a portion of the irradiation plenum defined by the irradiation chamber, and/or a crossflow manifold configured to provide a lateral flow of the process gas through at least a portion of the irradiation plenum defined by the irradiation chamber. The return manifold may evacuate or otherwise remove process gas from the irradiation plenum defined by the irradiation chamber.

Abstract: A fuel injector includes a forward end wall and an aft end wall. The fuel injector further includes side walls that extend between the forward end wall and the aft end wall. The forward end wall, the aft end wall, and the side walls collectively define an opening for passage of air. At least one fuel injection member is disposed within the opening and extends between the end walls. A fuel circuit is defined within the fuel injector. The fuel circuit includes an inlet plenum defined within the forward end wall of the fuel injector. The fuel circuit further includes a fuel passage that extends from, and is in fluid communication with, the inlet plenum. The fuel passage is defined within the at least one fuel injection member. The fuel passage has a cross-sectional area that varies along a length of the fuel injection member.

Abstract: Engine-mounting linkage systems may include a plurality of engine mounting links configured to couple an engine frame to an engine support structure of an aircraft. The plurality of engine-mounting links may include a forward link that is connectable to a forward frame portion of the engine frame and the engine support structure, and an aft link that is connectable to an aft frame portion of the engine frame and the engine support structure. The engine mounting linkage system may include an actuator that is connectable to the engine support structure and one of the plurality of engine-mounting links, or to the engine support structure and the engine frame. The actuator, when actuated, changes an inclination angle ? of at least one of the plurality of engine-mounting links.

Abstract: A damping device that includes features for damping bending vibration of a shaft rotating about its axis of rotation and methods for damping bending vibration utilizing the damping device are provided. In one exemplary aspect, the damping device includes a damping disc operatively coupled with a shaft, e.g., of a turbine engine or shaft system. The damping disc is at least partially received within a chamber defined by a housing. The chamber of the housing is configured to receive a damping fluid. When the shaft is rotated about its axis of rotation, the damping disc is movable within the chamber to move the damping fluid such that the damping fluid absorbs bending vibration emitted by the shaft. The damping fluid moved by the damping disc dampens bending vibration emitted by the shaft.

Abstract: A turbine engine and associated methods for a combustor as shown and described. The turbine engine including a combustor with a combustor liner having dilution openings and a geometry that changes along an axial direction. The combustor further having a baffle surrounding a combustor liner defining a combustion chamber of the combustor. A method for controlling nitrogen oxides within the combustor, including injecting compressed air into the annular combustion chamber through any of the dilution openings described herein.

Abstract: The subject matter of the present disclosure generally relates to techniques for neuromodulation of a tissue (e.g., an organ) that include applying energy (e.g., ultrasound energy) into the tissue to cause altered activity at a synapse between a neuron and a non-neuronal cell. In one embodiment, the energy is applied to cause competing or opposing effects for bi-directional control of physiological processes.

Abstract: The present disclosure relates to a system and method for actively detecting an ingress of a medical probe. In accordance with certain embodiments, a method includes monitoring, with a sensor within a medical probe, an internal environment of the medical probe, detecting, with the sensor, at least one of a temperature, pressure, humidity, or concentration of a gas within the medical probe, determining, with a processor that is in communication with the sensor, whether a seal that hermetically seals the medical probe has failed as a function of at least one of the temperature, pressure, humidity, or concentration of the gas, and outputting, with the processor, a notification that indicates whether the seal has failed.

Abstract: Methods and systems are provided for cooling hot spots on a body coil assembly of an MRI system. In one embodiment, an airflow guide of a body coil assembly of an MRI system comprises a first surface that forms an air passage when the airflow guide is positioned on the body coil assembly, the air passage enclosed by the first surface and a second, outer surface of an RF coil of the body coil assembly, the airflow guide configured to channel cool air generated by a fan to the second, outer surface of the RF coil. The airflow guide may be arranged circumferentially around a portion of the RF coil at one or more ends of the RF coil. The airflow guide may be manufactured as a plurality of airflow guide segments that are glued together.

Abstract: A cooling system is provided. The cooling system includes a condenser configured to condense a coolant from a vapor state to a liquid state and an evaporator configured to evaporate the coolant from the liquid state to the vapor state. The evaporator defines a reservoir configured to contain a volume of the coolant in the liquid state. The cooling system further includes a vapor channel fluidly coupled to the condenser and the evaporator and configured to convey the coolant in the vapor state from the evaporator to the condenser, a liquid channel coupled to the condenser and the evaporator and configured to convey the coolant in the liquid state from the condenser to the evaporator, and a heat generating component disposed in the reservoir and immersed in the volume of the coolant in the liquid state. The heat generating component is configured to dissipate heat into the coolant.

Abstract: Systems and methods of detecting a fuel leak are provided. A method of detecting a fuel leak within a turbomachine combustor includes a step of monitoring, by a controller, a sensor output from a particulate matter sensor positioned on a component within the combustor. The sensor output includes one of a fault state sensor output or a non-fault state sensor output. The method further includes receiving, with the controller, the fault state sensor output from the particulate matter sensor when a fuel leak is present within the combustor.

Abstract: A system, method, and computer-readable medium for evaluating structural integrity of a gradient coil disposed in a magnetic resonance imaging system is provided. A sensor obtains a parameter reading of the gradient coil, wherein the parameter reading includes a back electromotive force (back EMF) measurement. The structural integrity of the gradient coil is determined as function of the back EMF measurement.