Apparatus and method for automatic detection and configuration of motor

Abstract

The invention relates to an apparatus and method for automatic detection and configuration of a motor. According to one aspect of an exemplary embodiment of the present disclosure, an imaging device or system (10) includes at least one motor (130) controlled by a motor driver. The motor (130) is selected from one of a plurality of motors (130) operable by the motor drive. The motor controller (120) is operable to output a modulated voltage to the motor (130), wherein the modulated voltage does not cause rotation of the motor (130). As the motor controller (120) outputs the modulated voltage, a resulting voltage or a resulting current through the motor (130) is measured. The motor controller (120) uses the measured voltage or current to identify which motor of the plurality of motors (130) is connected to the motor controller (120) and set at least one parameter in the motor controller (120) corresponding to the identified motor (130).

Description

Technical Field

[0001] The present disclosure relates generally to medical imaging systems, including mammography systems and devices, and more particularly to automatic detection and configuration of motors used with medical imaging devices. Background Art

[0002] Embodiments of the present invention relate generally to X-ray medical imaging, and more particularly to apparatus, systems and methods for performing various imaging procedures, such as mammographic imaging procedures, including but not limited to spectral mammography (SM), such as 2D / 3D dual energy contrast enhanced (CE) mammography, full field digital mammography (FFDM), or digital breast fusion tomography (DBT) mammography.

[0003] Spectral mammography (SM) is an X-ray imaging modality used to scan the breast for screening, diagnosis and / or interventional examinations. The effectiveness of mammography is affected by many factors, one of which is the two-dimensional (2D) rendering of the images obtained using SM.

[0004] Alternative systems to SM are also known for breast imaging. Some examples include full-field digital mammography that captures images directly onto a flat-panel detector, computed tomography involving the use of a cassette containing imaging plates, or digital breast fusion tomography (DBT). A digital breast fusion tomography (DBT) or mammo-tomo system is a specialized mammography system that acquires several (e.g., dozens) of angularly offset projection X-ray images and reconstructs a three-dimensional (3D) image data set using the resulting X-ray image data.

[0005] The 3D image dataset is used to form various volumetric representations of the imaged breast, including the entire 3D volume of the breast, and various 3D segments of the 3D volume, such as slices or slabs of specified thickness constituting the 3D volume oriented to provide desired views of one or more regions of interest (ROIs) detected within the 3D image dataset.

[0006] Additionally, when a 3D image dataset of the breast has been generated, after use in a suitable diagnostic procedure, these 3D image datasets can be used to guide a biopsy device used with a DBT system into the breast to obtain a biopsy of a region of interest (ROI) identified within the 3D image dataset. In a DBT system, the biopsy device is disposed directly on the DBT system so that the 3D image dataset can be used to guide the biopsy device to the ROI to perform the biopsy.

[0007] In connection with the use of mammographic equipment, the process of obtaining high quality mammographic images from breast tissue requires a technician to position a patient's breast between one or more paddles and / or support surfaces that compress the breast in order to immobilize and flatten the breast during image acquisition. The compressive forces applied to the breast improve image quality by reducing the thickness of the breast while spreading the breast tissue over a larger area, which facilitates interpretation of the images obtained because the amount of overlying tissue of the imaged intra-breast structures is minimized.

[0008] In many diagnostic mammographic imaging devices, such as the diagnostic mammographic imaging device disclosed in U.S. Patent Application Publication No. US20200060632, entitled Apparatus And Method For Mammography Breast Compression, the entire contents of which are expressly incorporated herein by reference for all purposes, breast compression on the mammographic imaging device is controlled by a technician using a foot switch with a binary positioning system, i.e., the foot switch is movable between an "on" position, in which the compression paddle moves, and an "off" position, in which the compression paddle is stationary. When the foot switch is in the "on" position, the paddle moves along the first axis toward the breast at the full operating speed of the motor operably connected to the paddle until contact of the paddle with the breast is detected. In addition to or in lieu of the foot switch, the mammographic imaging device may include a fine movement adjustment knob. Rotation of the knob by the technician moves the paddle toward or away from the breast at a speed less than the full operating speed of the motor, thereby providing finer control than a foot switch to more accurately position the paddle against the breast to achieve a desired compression force on the breast.

[0009] Additionally, the imaging device may include controls for positioning the imaging head in order to control the paddle along the first axis to compress the breast tissue. Once the breast tissue is positioned, the imaging head may need to be positioned in a particular orientation relative to the breast tissue to obtain a desired image. The imaging head may be located on a gantry to allow for lateral and longitudinal positioning relative to the breast tissue, for example, in a two-dimensional coordinate system. Optionally, the imaging head may be rotated relative to the breast tissue. The imaging head may first be positioned in two dimensions and then configured to pivot about a desired position, or the imaging head may be rotated in an arc about the breast tissue to obtain a desired angle at which to acquire an image.

[0010] Each movement of the imaging device is achieved by a motor and a controller for the motor. Typically the motor and motor controller are provided in pairs. By providing the motor and motor controller as a pair, the motor controller can be pre-configured with parameters to optimize the performance of the motor. Over time, the motor may wear out and / or require replacement. When replacement is required, a motor of the same make and model as the original motor may not be available. For example, supply chain issues may cause the original motor to be unavailable for an unknown period of time. Alternatively, the useful life of the original may be so long that a new version of the motor is provided by the original manufacturer. Regardless of the reason why a replica of the original motor is unavailable, selecting a motor of a different make and model than the original motor may result in the motor having significantly different operating characteristics.

[0011] The physical construction of a motor determines many of the operating characteristics of the motor. For example, a direct current (DC) motor has an armature resistance, armature inductance, back electromotive force constant, and motor torque constant based on the physical construction of the motor. The values ​​of these operating characteristics of the motor can be stored as parameters in a motor controller. The motor controller can then use these parameter values ​​to generate an output voltage to achieve the desired operation of the motor. By pairing the motor and the motor controller, the values ​​of the operating characteristics of the original motor are stored in the motor controller. However, when the motor is changed, the previous values ​​stored in the motor controller may no longer correspond to the operating characteristics of the new motor. Using parameter values ​​from the original motor that do not correspond to the operating characteristics of the new motor may result in reduced performance or even unstable operation of the new motor.

[0012] Therefore, in view of the above-mentioned shortcomings of prior art motor controllers for imaging systems, it is desirable to develop an improved apparatus, system, and method for identifying a motor connected to a motor controller and adjusting parameters of the motor based on the operating characteristics of the identified motor. Summary of the invention

[0013] According to one aspect of an exemplary embodiment of the present disclosure, an x-ray imaging detector includes: a motion axis; a DC motor operable to drive a portion of the x-ray imaging detector on the motion axis; and a motor controller operable to control the rotation of the DC motor. The motor controller includes: a memory operable to store a plurality of instructions; and a processor operable to execute the plurality of instructions. The processor is operable to output a modulated DC voltage to the DC motor, wherein the modulated DC voltage does not cause the rotation of the DC motor. As the modulated DC voltage is output, a voltage or current passing through the DC motor is measured, and the DC motor is identified based on the voltage or current measured through the DC motor.

[0014] According to yet another aspect of an exemplary embodiment of the present disclosure, a method for identifying a DC motor for an x-ray imaging device outputs a modulated DC voltage from a motor controller to the DC motor, wherein the modulated DC voltage does not cause the DC motor to rotate. As the modulated DC voltage is output, a voltage or current passing through the DC motor is measured using the motor controller, and the DC motor is identified based on the voltage or current measured through the DC motor.

[0015] According to yet another aspect of an exemplary embodiment of the present disclosure, a method for identifying a DC motor for an x-ray imaging device selectively enables a first pair of switching devices and a second pair of switching devices using a motor controller. When the first pair of switching devices is enabled, a DC voltage having a first polarity is output to the DC motor, and when the second pair of switching devices is enabled, a DC voltage having a second polarity is output to the DC motor, wherein the second polarity is opposite to the first polarity. As the first pair of switching devices and the second pair of switching devices are selectively enabled, a voltage or current passing through the DC motor is measured using the motor controller. The DC motor is identified based on the voltage or the current measured through the DC motor.

[0016] These and other exemplary aspects, features and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings illustrate the best mode presently contemplated of practicing the invention.

[0018] In the attached picture:

[0019] Figure 1 is a perspective view of an imaging device in the form of a mammography apparatus for imaging breast tissue of a patient according to an embodiment of the present disclosure.

[0020] Figure 2 yes Figure 1 A diagram of a system showing a radiation source of the system in a scanning position according to one embodiment of the present disclosure.

[0021] Figure 3 According to the embodiments of the present disclosure Figure 1 An isometric view of a mammography system including a first embodiment of a breast retaining pad thereon.

[0022] Figure 4 According to an embodiment of the present disclosure, a biopsy device is provided. Figure 3 An isometric view of another embodiment of a mammography system and breast retention pad.

[0023] Figure 5 It is used to control Figure 1 An isometric view of an exemplary motor and motor controller for one axis of motion in a mammography system.

[0024] Figure 6 yes Figure 5 A block diagram representation of an exemplary motor and motor controller.

[0025] Figure 7 yes Figure 6 Schematic representation of a part of a motor controller.

[0026] Fig. 8A is used for Figure 7 A graphical representation of the switching signals for a pair of switches in an H-bridge is shown.

[0027] Figure 8B is used for Figure 7 A graphical representation of the switching signals of a pair of switches in an H-bridge is shown, where Figure 8B The switch pair controlled by the switch signal in Fig. 8A The pair of switches controlled by the switching signals in are complementary.

[0028] Figure 8C is through Fig. 8A and Figure 8B Graphical representation of the current flow of two different DC motors controlled by switching signals.

[0029] Fig. 9 is from a connection to Fig. 8A and Figure 8B Graphical representation of the voltage discharge of the capacitors of two different DC motors controlled by switching signals.

[0030] Fig.10 is a flow chart illustrating steps for detecting and configuring a motor according to one embodiment of the present invention. DETAILED DESCRIPTION

[0031] One or more specific embodiments will be described below. In order to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be understood that, as in any engineering or design project, in the development of any such actual implementation, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as complying with system-related and business-related constraints that may differ between implementations. In addition, it should be understood that such development efforts may be complex and time-consuming, but are still routine tasks of design, fabrication, and manufacturing for ordinary technicians who benefit from this disclosure.

[0032] When introducing elements of various embodiments of the present invention, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of such elements. The terms "comprising," "including," and "having" are intended to be inclusive, and mean that there may be additional elements in addition to the listed elements. Furthermore, any numerical examples in the following discussion are intended to be non-limiting, and thus the additional numerical values, ranges, and percentages are within the scope of the disclosed embodiments.

[0033] As used herein, "electrically coupled," "electrically connected," and "electrically communicating" means that the referenced elements are directly or indirectly connected such that current can flow from one to the other. The connection may include a direct conductive connection (i.e., without intervening capacitors, inductors, or active elements), an inductive connection, a capacitive connection, and / or any other suitable electrical connection. There may be intervening components.

[0034] Furthermore, while the embodiments disclosed herein are described with respect to mammographic apparatus for 2-dimensional imaging of breast tissue, it should be understood that embodiments of the present invention may be applicable to other types of imaging devices for both 2-dimensional and 3-dimensional imaging, including, for example, fluoroscopy, full-field digital mammography, digital breast fusion tomography (DBT), and spectral mammography (mono- or multi-energy), as well as other types of imaging devices for imaging procedures of tissue other than breast tissue.

[0035] Reference now Figures 1 to 3 , shows the main components of an exemplary imaging system 10 formed as a mammography system 12 for imaging breast tissue according to an embodiment of the present invention. The system 10 includes a radiation source / X-ray source 16, a radiation detector 18, and a collimator 20, and the system is such as the system disclosed in U.S. Patent Application Publication No. US20200060632, entitled Apparatus And Method For Mammography Breast Compression, the entire contents of which are expressly incorporated herein by reference for all purposes. The radiation source 16 is movable between multiple imaging positions relative to the detector 18 and is operable to emit radiation rays 22 ( Figure 2 ), which are received by radiation detector 18 to provide an image of an object such as breast 52. In an embodiment, system 10 may include a patient shield 24 mounted to radiation source 16 via a mask rail 26 to prevent the patient's head from obstructing the radiation rays and to protect the patient from radiation rays 22.

[0036] Still further reference Figure 1 and Figure 2, the system 10 also includes a compression paddle or plate 28 and a support structure 30 to which one or more of the radiation source 16, the radiation detector 18 and / or the compression plate 28 can be mounted. In an embodiment, the system 10 may also include a controller 32. The controller 32 may be a workstation having at least one processor / central processing unit / computer and a memory device / database storing information and / or instructions used by the controller 32 for the operation of the system 10, such as Figure 1 As shown, or in other embodiments, the controller 32 may be embedded / integrated into one or more of the various components of the system 10 disclosed above. In an embodiment, the controller 32 may be electrically connected to the radiation source 16, the radiation detector 18, and / or the compression plate 28 via a cable 34. As will be appreciated, in an embodiment, the connection 34 may be a wireless connection. In an embodiment, the controller 32 may include a radiation shield 36 that protects an operator of the system 10 from the radiation rays 22 emitted by the radiation source 16. The controller 32 may also include a display 38, a keyboard 40, a mouse 42, and / or other appropriate user input devices that facilitate control of the system 10 via a user interface 44.

[0037] like Figure 1 and Figure 2 As further shown, the radiation source 16, together with the radiation detector 18, forms part of an x-ray system that provides x-ray images for the purpose of imaging a body part of a patient, such as a breast 52. As described above, the radiation source 16 emits radiation rays 22 such that the radiation rays 22 travel from the radiation source 16 to the radiation detector 18. Although the radiation rays 22 are discussed herein as x-rays, it should be understood that the radiation source 16 may emit other types of electromagnetic rays that can be used to image a patient. The radiation source 16 may be mounted to the support structure 30 so that the radiation source can rotate relative to the radiation detector 18 about an axis 46, but movement of the radiation source 16 in a path other than rotation about a fixed axis, such as during digital breast fusion tomography (DBT), is also contemplated. In an embodiment, the radiation detector 18 may be configured to rotate or translate within its housing, such as in the directions indicated by arrows 53 and 55.

[0038] exist Figure 1 In the illustrated exemplary embodiment of , the radiation source 16 and the detector 18 are mounted to a gantry 90, which is secured to the support structure 30. The support structure 30 houses a translation mechanism 92, which is operably connected to the gantry 90. The translation mechanism 92 is operable to vertically move the gantry 90 relative to the support structure 30 so as to position the gantry 90 at an appropriate height to accommodate the size of the patient on which the system 10 is utilized. The translation mechanism 92 is also operable to rotate the gantry 90 about the horizontal axis 46 relative to the support structure 30 so as to rotationally position the gantry 90 relative to the patient as desired.

[0039] The gantry 90 includes a generally C-shaped body 94 with the radiation source 16 at one end and the detector 18 at the opposite end. In this configuration, the radiation source 16 is disposed in alignment with the detector 18 regardless of the vertical and / or rotational orientation of the gantry 90, such as to position the radiation source 16 and the detector 18 relative to the patient's breast 52 to obtain x-ray images in various orientations, such as for craniocaudal (CC) or mediolateral oblique (MLO) views, etc. In this position, the detector 18 is capable of receiving x-rays 22 emitted from the radiation source 16 that pass through the portion of the patient (i.e., the patient's breast 52) ​​located between the radiation source 16 and the detector 18 to generate image data for transmission to the controller 32 of the mammography device / system 10 to create a 3D image data set for viewing by a physician (such as by using DBT), among other known methods.

[0040] Additionally, in another embodiment, radiation source 16 may be attached to gantry 90 to rotate and / or move independently of gantry 90 and detector 18 to enable radiation source 16 to capture x-ray images of a patient's breast at various angles (e.g., between + / - 60°) relative to detector 18. Images acquired by radiation source 16 between these angles may be used to create stereoscopic images during a biopsy procedure using system 10 or for DBT when system 10 is operated in an imaging mode.

[0041] As described above, radiation detector 18 receives radiation rays 22 emitted by radiation source 16. In an embodiment, data regarding radiation rays 22 received by radiation detector 18 may be electronically transmitted from radiation detector 18 to controller 32 via cable / electronic connection 34, so that controller 32 generates one or more images that may be displayed on display 38 and stored in a memory device.

[0042] The compression plate 28 is operable to move toward and away from the radiation detector 18, as indicated by arrow / compression axis 48, in response to instructions from the controller 32 or in response to instructions from a controller or switch controller 80 on or near the mammography system 10, so that the compression plate 28 flattens and holds a body part (e.g., a breast 52) ​​against a surface 50 of the radiation detector 18. In this regard, the radiation detector 18 and its surface 50 are referred to herein as a "compression surface or support plate" that cooperates with the compression plate 28 to compress and clamp the patient's breast therebetween.

[0043] In one exemplary embodiment, to maintain the position of the patient's breast 52 stationary during the imaging and / or biopsy procedure, the compression plate 28 is attached to a plate or paddle support mechanism 45 located on and / or within the gantry 90 that positions the compression plate 28 directly above and aligned with the detector 18 / support plate and is operably connected to the controller 32. The plate support mechanism 45 is operable within the gantry 90 at any rotational or vertical position of the gantry 90 to move the plate 28 in a line toward or away from the detector 18 / support plate. The mechanism 45 can have any of a variety of different configurations, but in one exemplary embodiment takes the form of a compression screw mechanism that is operable to move the plate 28 into engagement with the patient's breast 52 to apply a predetermined pressure / compression on the breast 52 to maintain the breast 52 in a stationary position between the plate 28 and the detector 18 / support plate during the imaging and / or biopsy procedure.

[0044] Now refer to Figure 4 The imaging system 10 may further or alternatively include a biopsy tool 100, such as the disclosed biopsy system, which is selectively removable from the imaging system 10. In such an embodiment, the radiation source 16 together with the radiation detector 18 form part of an X-ray system that provides X-ray images for guiding the biopsy tool 100 to a suspicious site within a body part of a patient. Figure 4 As shown, in embodiments, biopsy tool 100 may be disposed on support structure 30 such that it also rotates about axis 46 in a manner similar to radiation source 16 and / or moves vertically and / or horizontally in a manner similar to compression plate 28 .

[0045] The above-mentioned imaging system includes multiple axes of motion. As discussed, the radiation source 16 can rotate about the first axis of motion 46. The compression plate 28 can move toward or away from the radiation detector 18 along the second axis of motion 48. The radiation detector 18 can be configured to translate along a pair of axes (represented by arrows 53 and 55). The above-mentioned axes are exemplary and are not intended to be limiting. Depending on the application requirements, various other axes of motion may exist in the imaging system. As used herein, an axis of motion refers to an axis on which a portion of the imaging system moves. This portion of the imaging system can translate along the axis, rotate around the axis, or a combination thereof. In addition, a portion of the imaging system can move along multiple axes of motion.

[0046] Movement along or about one of these axes of motion requires a driving force to move the portion of the imaging system 10 along the axis of motion. Figure 5, illustrates an exemplary system for driving a portion of the imaging system 10. The motor controller 120 is configured to drive a motor 130 that is operably connected to the motor controller 120. The motor controller 120 receives commands from an external source, such as the controller 32 for the imaging system 10. The commands may be received via a communication network connected at a network port 122 or via any other suitable cable, wireless connection, or combination thereof. Terminals 124 from the motor controller 120 provide interconnection with the motor 130. A single cable 126 may extend between the motor controller 120 and the motor 130. The single cable includes a plurality of conductors to carry voltage to the motor 130, carry command signals to accessory devices mounted on the motor (such as a brake 138), and / or receive feedback signals from the motor 130. A position feedback device 134, such as an encoder, may be mounted on the motor 130, for example, and provide a signal corresponding to the angular position of the motor 130. The drive shaft 136 extends from the motor 130 and may be coupled to a gear box, another drive shaft, a drive belt, a drive chain, or any other suitable drive member to drive the portion of the imaging system 10 connected to the motor 130 .

[0047] The motor 130 is mounted on the imaging system 10, within or near the portion of the imaging system 10 being controlled. For example, a motor may be mounted within the support structure 30 or on the gantry 90 to drive a translation mechanism 92 that causes the gantry to move up and down along the support structure. Similarly, a second motor 130 may be mounted within the support structure 30 or within the gantry 90 to drive the translation mechanism 92 that causes the gantry to rotate relative to the support structure. A motor controller 120 for each motor 130 may be mounted within the support structure 30 or the gantry 90, near the motor 130 being controlled. Optionally, the motor controller 120 may be mounted within a controller 32 for the imaging system 10, and the cables between the motor controller 120 and the motor 130 may be included in the cables / electronic connections 34 between the controller 32 and the support structure 30.

[0048] Also refer to Figure 6, the motor controller 120 includes a power source 121 and a power conversion section 123. The power source 121 can be a battery housed within the motor controller 120. Optionally, the battery can be recharged via a connection to an electrical service within a building in which the imaging system is installed. A power cable can extend to the imaging system, and a battery charger can be incorporated into the imaging system. Optionally, the battery can be removed from the imaging system for charging, in which multiple batteries can be available and swapped into the system as needed. According to yet another aspect of the present invention, the power source 121 can be directly connected to the electrical service and receive power from the electrical service. The power source 121 can include a first power converter that can receive an alternating current (AC) voltage, such as one hundred and twenty volts (120VAC) or two hundred and forty volts (240VAC), and convert the AC voltage to a direct current (DC) voltage. The first power converter can include a passive rectifier having devices such as diodes that conduct or block current based on voltage levels rather than conducting in response to a control signal. Optionally, the first power converter may include an active rectifier having devices such as transistors that selectively conduct current based on a control signal provided to one of the terminals of the device. The power source 121 may also include: one or more power converters (such as a buck converter or a boost converter) to convert the DC voltage from one voltage level to another voltage level; and / or one or more voltage regulators to supply voltage at a desired voltage level based on the requirements of the imaging system 10.

[0049] The motor controller 120 also includes a processor 125 and a memory 127. The processor 125 can be a single processor or multiple processors that execute asynchronously or synchronously. The processor 125 can be a microprocessor or can be implemented in a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), or other suitable processing device. The memory 127 can be a single memory device or multiple memory devices, wherein at least a portion of the memory is a non-volatile memory. The memory 127 is configured to store instructions for execution by the processor 125 and store parameters corresponding to the desired operation of the motor controller 120 and / or the motor 130.

[0050] According to one aspect of the present invention, the motor 130 is a DC motor. The DC motor 130 includes a stator 131 and a rotor 133. The stator 131 is stationary and generates a magnetic field in which the rotor 133 rotates. The stator 131 may include, for example, a magnetic structure having a north pole facing the rotor 133 on one side of the motor 130 and a south pole facing the rotor 133 on the opposite side of the motor 130. The magnetic structure establishes a constant magnetic field within the motor 130. Optionally, a field coil may be provided in the stator 131. The motor controller 120 may be configured to supply a DC current to the field coil, thereby establishing a magnetic field through the DC motor when the current is conducted in the field coil.

[0051] The motor 130 may include additional components connected to the motor. According to the illustrated embodiment, the brake 138 and the position feedback device 134 (such as a resolver or encoder) are both connected to one end of the motor 130. The brake 138 includes a control circuit 139, which is configured to receive a control signal to selectively open or close the brake. Typically, the coil in the brake 138 is energized to disconnect the brake 138, thereby allowing the rotor 133 to rotate. When the coil is de-energized, the brake 138 remains unchanged, thereby applying a holding force on the rotor 133 to prevent the motor 130 from rotating. The brake control circuit 139 may also include one or more feedback signals to the motor controller 120 to provide verification of the current operating state of the brake 138. Optionally, the brake control circuit 139 may be completely included in the motor controller 120. The cable 126 between the motor controller 120 and the brake 138 may include a pair of electrical conductors, which are connected to the brake coil to energize or de-energize the brake. The position feedback device 134 also includes a control circuit 135. The control circuit 135 of the position feedback device 134 detects the rotation of the motor 130 and outputs a feedback signal corresponding to the rotation. The output signal can be, for example, a sinusoidal signal or a pair of offset sinusoidal signals, where one rotation of the motor causes the sinusoidal signal to pass through a full cycle or three hundred and sixty degrees. Optionally, the output signal can be converted into a pulse train or an orthogonal pulse train to provide multiple pulses per revolution of the motor. The motor controller 120 receives the feedback signal and executes instructions including one or more control routines that utilize the feedback signal to achieve the desired operation of the motor.

[0052] Also refer to Figure 7 The power conversion section 123 of the motor controller 120 is configured to supply a desired output voltage to the motor 130 to control the rotation of the motor. For the exemplary DC motor 130, the power conversion section 123 includes an H-bridge configuration. The H-bridge includes four electronic switching devices 150. Figure 7As illustrated in the figure, the first electronic switching device at least partially defines switch one S1, also identified by reference numeral 150A; the second electronic switching device at least partially defines switch two S2, also identified by reference numeral 150B; the third electronic switching device at least partially defines switch three S3, also identified by reference numeral 150C; and the fourth electronic switching device at least partially defines switch four S4, also identified by reference numeral 150D. As used herein, reference numerals without letters generally refer to a single element or each of a plurality of similar elements. Reference numerals with letters refer to specific instances of elements. Using the electronic switching device 150 introduced above as an example, references to the electronic switching device 150 or to the electronic switching device 150 generally refer to each electronic switching device, while references to the first electronic switching device 150A, the second electronic switching device 150B, the third electronic switching device 150C, or the fourth electronic switching device 150D refer to specific instances of the electronic switching device 150. The electronic switching device 150 may be implemented by a transistor such as a bipolar junction transistor (BJT), a metal oxide semiconductor field effect transistor (MOSFET), an insulated gate bipolar transistor (IGBT), etc. The transistor receives a reference voltage at one of its terminals and a switching signal at another of its terminals to selectively conduct the reference voltage through the device.

[0053] In operation, the motor controller 120 is operable to control the operation of the motor 130. For a brushed DC motor, the armature is wound on the rotor 133 and the terminals of the windings are connected to a rotating commutator. The rotating commutator is split so that one half of the commutator is connected to one end of the armature and the other half of the commutator is connected to the other end of the armature. A cable 126 from the motor controller 120 supplies voltage to stationary brushes mounted within the motor 130. When a DC voltage is applied across the brushes at a first polarity, current flows through the armature in the motor 130 in a first direction. When a DC voltage is applied across the brushes at a second polarity opposite to the first polarity, current flows through the armature in the motor 130 in a second direction opposite to the first direction. The current passing through the armature generates an electromagnetic field that interacts with the electromagnetic field generated by the magnetic structure present in the rotor 133. The polarity of the current determines the direction of rotation of the motor.

[0054] Reference again Figure 7, the switches 150 in the H-bridge are closed in pairs to supply voltage through the motor 130 with the desired polarity. A reference voltage is provided at the top of the circuit. The first electronic switching device 150A and the fourth electronic switching device 150D define a first pair of electronic switching devices. The second electronic switching device 150B and the third electronic switching device 150C define a second pair of electronic switching devices. When the first pair of electronic switching devices are both closed and the second pair of electronic switching devices are both open, the reference voltage exists on the left side of the motor 130 and the common voltage or ground voltage exists on the right side of the motor, causing current to flow through the motor with a first polarity. When the second pair of electronic switching devices are both closed and the first pair of electronic switching devices are both open, the reference voltage exists on the right side of the motor 130 and the common voltage or ground voltage exists on the left side of the motor, causing current to flow through the motor with a second polarity opposite to the first polarity. The terms "top", "left side", and "right side" are relative to Figure 7 The relative terms used in the schematic illustrations of FIG. 1 are not intended to indicate the physical relationship or orientation of the motor 130 , the motor controller 120 , or any connections therebetween.

[0055] The speed at which the motor 130 rotates is a function of the magnitude of the DC voltage supplied to the motor 130. The motor controller 120 controls the desired operation of the motor 130 by changing the voltage level applied to the motor 130. The voltage level is changed by modulating the output voltage to the motor 130. The modulation alternately connects and disconnects the reference voltage to the motor. The modulation occurs within a periodic interval, where the voltage is connected within a portion of the interval and disconnected within a portion of the interval. When zero speed is desired, the reference voltage is not connected within any portion of the interval, or in other words, the reference voltage is connected within zero percent of the interval. When the rated speed is desired, the reference voltage is connected within one hundred percent of the interval. However, if a speed different from zero speed or rated speed is desired, the motor controller 120 alternately connects and disconnects the reference voltage within the periodic interval. Closing a pair of electronic switching devices may only connect the full voltage across the motor. However, if a pair of electronic switching devices is closed within a first portion of the periodic interval and disconnected within another portion of the periodic interval, the average voltage across the motor during a period corresponds to the percentage of the period during which the pair of electronic switching devices are closed. The resulting motor voltage is represented as an average voltage. Maintaining a modulated output voltage in which a pair of electronic switching devices are closed between one percent and ninety-nine percent causes the motor 130 to rotate within a range of one percent to ninety-nine percent of the rated speed.

[0056] The present invention utilizes modulated output voltage to determine which motor 130 is connected to the motor controller 120. As an initial step, the magnitude of the DC voltage supplied to the motor 130 is selected. As discussed above, providing a rated DC voltage to the motor 130 will cause the motor to rotate at a rated speed. However, Figure 7The circuit illustrated in includes two different reference voltages. A first reference voltage V1 is connected to the H-bridge via a switch S0, which is also identified by reference numeral 140. Switch zero 140 is at least partially defined by an active electronic switching device, such as a transistor. The active electronic switching device receives a command signal to selectively connect the first reference voltage V1 to the H-bridge. A second reference voltage V2 is also connected to the H-bridge. The second reference voltage V2 charges capacitor C1 (also identified by reference numeral 146) according to a time constant defined by the value of resistor R1 (also identified by reference numeral 144) and capacitor C1 146. When capacitor 146 is charged, the magnitude of the voltage present across capacitor C1 will be equal to the magnitude of the voltage from the second reference voltage V2. The second reference voltage V2 is connected to the H-bridge via a diode D1 (also identified by reference numeral 142), which acts as a passive electronic switching device.

[0057] The selection of the voltage to be applied to the H-bridge is controlled by the active electronic switching device of switch zero 140. The first reference voltage V1 is selected based on the motor 130 to be controlled. According to one aspect of the invention, the motor 130 operates at a nominal DC voltage of forty-eight volts (48 VDC). Therefore, V1 is a DC voltage having an amplitude of 48 VDC provided from the power source 121. The second reference voltage V2 is selected to have an amplitude less than 48 VDC. According to one aspect of the invention, the second reference voltage is selected to have an amplitude of fifteen volts (15 VDC). As shown in FIG. Figure 7 It can be observed from the schematic illustration in that when switch zero 140 is open, no voltage from the first reference voltage V1 reaches the H-bridge. Similarly, no voltage from the first reference voltage is present at the cathode of diode D1. The voltage potential from the second reference voltage V2 will forward bias diode D1, thereby supplying the second reference voltage to the H-bridge. When switch zero 140 is closed, the voltage from the first reference voltage V1 is supplied to the H-bridge. Since the amplitude or potential of the voltage from the first reference voltage is greater than the amplitude or potential of the voltage from the second reference voltage, diode D1 is reverse biased, thereby preventing the second reference voltage from being supplied to the H-bridge.

[0058] During the motor detection process, the modulated DC voltage supplied from the motor controller 120 to the motor 130 does not cause rotation of the DC motor. As an initial step to supply a modulated DC voltage that does not cause rotation of the DC motor, the second reference voltage V2 is selected to utilize a reference voltage having a lower amplitude than the first reference voltage. As discussed above, the speed at which the DC motor rotates is at least partially determined by the amplitude of the applied DC voltage. Therefore, supplying a DC voltage with a lower maximum voltage also reduces the value of the modulated voltage. Therefore, for motor detection, the motor controller 120 opens the switch zero 140, thereby connecting the second reference voltage V2 to the H-bridge.

[0059] Next, turn to Figure 8 to Fig.10 The modulation of the H bridge is also controlled to prevent the DC motor from rotating. As shown in step 230, the motor controller 120 outputs a modulated DC voltage. The modulated DC voltage uses a second reference voltage V2 and is based on Fig. 8A and Figure 8B The control signals shown in are alternately connected to the H-bridge. The first switching signal 200 is provided to the first electronic switching device 150A and the fourth electronic switching device 150D as a first pair of switching devices. The second switching signal 205 is provided to the second electronic switching device 150B and the third electronic switching device 150C as a second pair of electronic switching devices. As discussed above, when the first pair of electronic switching devices is closed, a voltage from the second reference voltage V2 is applied across the motor 130 with a first polarity. When the second pair of electronic switching devices is closed, a voltage from the second reference voltage V2 is applied across the motor 130 with a second polarity opposite to the first polarity. In contrast to modulation for controlling the rotation of a motor, in which a voltage is selectively applied to a pair of switches during a portion of a switching period, the voltage during motor detection is alternately provided to each pair of switches, thereby continuously reversing the polarity of the voltage applied to the motor. In Figure 8C The resulting DC current through the DC motor is illustrated in the graphs 210, 215 shown in FIG. The current first transitions from a positive current to a negative current. The current then transitions from a negative current to a positive current. The current continues to oscillate between small positive and small negative values, maintaining an average value in the motor approximately equal to zero current.

[0060] Go to again Fig.10 , the motor controller 120 is configured to output a modulated DC voltage to the motor 130 for a predefined duration. As shown in step 232, the motor controller 120 monitors when the predefined duration is completed. If the duration is completed, the motor controller 120 jumps to step 238 to identify the motor, as will be discussed further below. However, if the predefined duration is not completed, the motor controller 120 measures the voltage or current provided to the DC motor 130.

[0061] At step 234, the motor controller 120 first determines whether to measure current or voltage. If current is to be measured, the motor controller 120 waits for a transition between the output first switch signal 200 and the second switch signal 205, as shown in step 236. If the transition between the switch signals does not occur, the motor controller 120 returns to step 230 and continues to generate a modulated waveform based on the valid switch signals 200, 205. However, when a transition between the switch signals occurs, the motor controller 120 measures the current present in the motor 130, as shown in step 238. Referring again to FIG. Figure 8C, the first graph 210 of current corresponds to the current present in the first motor during the modulation process. The second graph 215 of current corresponds to the current present in the second motor during the modulation process. Figure 8C As illustrated in , the peak current (whether positive or negative) occurs at the transition between the switching signals. Therefore, sampling at the transition point will generate the maximum value of the current and provide the largest variation in sampled values ​​between different motors. Also refer to Figure 7 , a current sensing resistor R2 (also identified by reference numeral 144) may be used to measure the current. The voltage across the resistor 144 is measured by the motor controller 120 and the current is determined according to Ohm's law. Optionally, various other current sensors may be utilized to measure the current through the motor 130. Figure 8C As shown, different motors respond differently to the modulated output voltage. A motor with a lower electrical time constant (which is determined by the armature inductance and armature resistance in the DC motor) will have a higher current peak amplitude, as shown in the first curve 210. A motor with a higher electrical time constant will have a lower amplitude current, as shown in the second curve 215. The motor controller 120 stores the current value when the output voltage is delivered to the motor, and uses the stored current value to identify which motor is connected to the motor controller 120.

[0062] If a voltage is to be measured, the motor controller 120 proceeds to step 240. The motor controller 120 is configured to measure the voltage present across the capacitor 146 to obtain a value for the modulated output voltage supplied to the motor 130. When the second reference voltage V2 is selected, the capacitor C1 146 is charged to a DC voltage level of the second reference voltage V2 according to a time constant defined by the values ​​of the resistor R1 144 and the capacitor C1 146. The capacitor 146 is charged to this DC voltage level before the modulated DC voltage is supplied to the motor 130. As the modulated DC voltage is supplied to the motor, the time constant defined by the values ​​of the resistor R1 144 and the capacitor C1 146 is selected so that charging of the capacitor 146 from the second reference voltage V2 occurs slower than discharging of the voltage from the capacitor 146 through the motor 130. Therefore, as the modulated DC voltage is supplied to the motor 130, the magnitude of the voltage present across the capacitor C1 146 decreases. Also referring to Fig. 9 , the rate at which the voltage across capacitor 146 drops is a function of the electrical time constant of motor 130 . Fig. 9Two graphs of the voltage across the capacitor 146 versus time are included as the modulated DC voltage is output to different DC motors. The first graph 220 illustrates a DC motor 130 having a short electrical time constant, and the second graph 225 illustrates a DC motor 130 having a long electrical time constant, where short and long are relative to each other. In the case of a shorter electrical time constant, the voltage level across the capacitor 146 will discharge faster than in the case of a longer electrical time constant. After the modulated DC voltage is supplied to the motor 130 for approximately one millisecond (1 ms), the voltage level has deviated by a sufficient amount so that the measured value of the voltage present across the capacitor 146 can be used to identify which motor 130 is connected to the motor controller 120. The motor controller 120 stores the measured value of the modulated DC voltage provided to the DC motor 130 to identify which motor is connected to the motor controller 120.

[0063] As previously indicated, it is desirable to generate a modulated output voltage that does not cause the DC motor 130 to rotate. In addition to reducing the amplitude of the applied voltage reference, reducing the duration that each switch signal 200, 205 is effective will also reduce the chance that the motor 130 will begin to rotate. According to one aspect of the present invention, the switch signals 200, 205 may alternate during each modulation period. A first period of the modulation interval may extend between times t0 and t1. A second period of the modulation interval may extend between times t1 and t2, and so on. During the first period, the first switch signal 200 to the first pair of switch devices is turned on for one hundred percent of the period. During the second period, the second switch signal 205 to the second pair of switch devices is turned on for one percent of the duration of the period. According to another aspect of the present invention, the first period of the modulation interval may extend between times t0 and t2, and the second period of the modulation interval may extend between times t2 and t4. If the duration of the modulation interval spans Fig. 8A and Figure 8B , then each of the first switch signal 200 and the second switch signal 205 is turned on within fifty percent of the modulation interval. The first switch signal 200 is turned on within the first half of the interval, and the second switch signal 205 is turned on within the second half of the interval.

[0064] In either case, the first switch signal 200 and the second switch signal 205 alternate for consecutive periods with an overall fifty percent modulation between the two signals. In other words, the first switch signal 200 and the second switch signal alternate with each other and are on for the same duration as each other. The result of the modulation is that the current in the motor alternately rises and falls as the switch signals 200, 205 alternate. Since the armature coils in the DC motor 130 have some inductance, the current through the DC motor 130 resists step changes, but over the duration of the switching interval, the current will rise and fall according to the applied voltage and the inductance present in the armature coils.

[0065] Return to reference Fig.10 , outputs a modulated DC voltage, and measures the current through the motor 130 for a predefined duration. When the duration is completed, the motor controller 120 performs steps 242 and 244 to identify which motor is connected to the motor controller 120 and adjusts the parameters stored in the memory 127 accordingly. The memory 127 of the motor controller 120 is configured to store a lookup table 129, wherein the lookup table includes a plurality of motors 130 and at least one operating characteristic corresponding to each motor 130 stored in the lookup table. The operating characteristic may be an electrical time constant of the motor, which is determined based on the armature inductance and armature resistance in the DC motor. The motor controller 120 may be configured to determine the value of the electrical time constant of the motor based on the measured voltage or the measured current. Optionally, as the modulated DC voltage is output to the motor, the expected value of the amplitude of the modulated DC voltage (when measuring the voltage) or the expected peak value of the current (when measuring the current) may be determined by the manufacturer of the motor controller 120 through experiments and stored in the motor controller 120 for a plurality of motors. When a new motor 130 is connected to the motor controller 120 , the motor controller outputs a modulated DC voltage and the measured voltage or current is compared to the expected voltage or current values ​​stored in the lookup table to identify which motor is connected to the motor controller.

[0066] According to yet another aspect of the present invention, the motor controller 120 may be configured to rapidly modulate the switching signal to minimize the available time for the current through the motor to rise and fall. According to one aspect of the present invention, the frequency at which the modulation occurs is greater than ten kilohertz (10kHZ). For example, if the motor controller 120 executes at a twenty kilohertz (20kHz) switching frequency (with fifty percent modulation between the two signals), each signal remains on for only twenty-five microseconds (25μs). During this short duration, the current may only rise by tens or hundreds of milliamperes. With the reduction in voltage level and the low rise in current, not enough power is generated in the motor 130 to overcome the motor inertia and start rotating. Therefore, the motor controller 120 is able to identify the connected motor without causing the motor to rotate.

[0067] According to yet another aspect of the invention, some motors 130 may include a brake 138 mounted to the motor. When the brake is mounted to the motor 130, the brake may remain in place because the modulated output voltage is provided to the motor to help prevent the motor from rotating.

[0068] After identifying the motor, the motor controller 120 can adjust the parameters stored in the memory 127 that correspond to the operation of the motor 130. The lookup table 129 for identifying the motor may also include a list of operating parameters for each motor 130. After identifying the motor 130, the motor controller 120 reads each of these parameters from the lookup table 129 and stores them in corresponding parameters for controlling the operation of the motor. Optionally, a second lookup table may be stored in the memory, where the first lookup table 129 is used to identify the motor and the second lookup table stores operating parameters for the motor.

[0069] It should be understood that the aforementioned compositions, devices and methods of the present disclosure are not limited to specific embodiments and methods, as these may vary. It should also be understood that the terms used herein are only for the purpose of describing specific exemplary embodiments, and are not intended to limit the scope of the present disclosure, which will only be limited by the appended claims.

Claims

1. An X-ray imaging detector (10), comprising: a. Axis of motion (46); b. a direct current (DC) motor (130) operable to drive a portion of the x-ray imaging detector (10) on the axis of motion (46); and c. a motor controller (120) operable to control the rotation of the DC motor (130), wherein the motor controller (120) further comprises: i. a memory (127) operable to store a plurality of instructions, and ii. a processor (125) operable to execute the plurality of instructions to: outputting a modulated DC voltage to the DC motor (130), wherein the modulated DC voltage does not cause rotation of the DC motor (130), As the modulated DC voltage is output, measuring the voltage or current supplied to the DC motor (130), and The DC motor (130) is identified based on the voltage or current provided to the DC motor (130).

2. The x-ray imaging detector (10) according to claim 1, further comprising: a. a plurality of electronic switching devices (150A, 150B, 150C, 150D) to selectively provide the modulated DC voltage to the DC motor (130); b. a first voltage source (V1), the first voltage source having a first amplitude; c. a first voltage selection switch (140), the first voltage selection switch being operable to selectively connect the first voltage source (V1) to the plurality of electronic switching devices (150A, 150B, 150C, 150D); d. a second voltage source (V2), the second voltage source having a second amplitude; and e. A second voltage selection switch (D1) operable to selectively connect the second voltage source (V2) to the plurality of electronic switching devices (150A, 150B, 150C, 150D).

3. The x-ray imaging detector (10) of claim 1, wherein the motor controller (120) further comprises: a. A first electronic switching device (150A); b. a second electronic switching device (150B); c. a third electronic switching device (150C); and d. A fourth electronic switching device (150D), wherein the processor (125) is further operable to: i. selectively enabling the first electronic switching device (150A) and the fourth electronic switching device (150D) as a first pair of switching devices to output a DC voltage having a first polarity to the DC motor (130), and ii. selectively enabling the second electronic switching device (150B) and the third electronic switching device (150C) as a second pair of switching devices to output a DC voltage having a second polarity to the DC motor (130), the second polarity being opposite to the first polarity.

4. The x-ray imaging detector (10) of claim 3, wherein the processor (125) is further operable to alternately connect the first pair of switch devices (150A, 105D) and the second pair of switch devices (150B, 150C).

5. The x-ray imaging detector (10) of claim 4, further comprising a current sensor (R2) operable to generate a feedback signal corresponding to the current provided to the DC motor (130), wherein the processor (125) is further operable to measure the current when the processor (125) switches between the first pair of switching devices (150A, 150D) and the second pair of switching devices (150B, 150C).

6. The x-ray imaging detector (10) of claim 4, further comprising a voltage sensor (144, 146) operable to generate a feedback signal corresponding to the voltage provided to the DC motor (130).

7. The x-ray imaging detector (10) of claim 4, wherein the frequency at which the processor (125) alternately connects the first pair of switch devices (150A, 150D) and the second pair of switch devices (150B, 150C) is high enough to prevent the DC motor (130) from rotating.

8. The x-ray imaging detector (10) of claim 1, wherein: a. The memory (127) is further operable to store a lookup table (129), and b. The processor (125) is further configured to identify the DC motor (130) by comparing the voltage or the current measured through the DC motor (130) with a value stored in the lookup table (129).

9. The x-ray imaging detector (10) of claim 1, wherein: a. The memory (127) is further operable to store at least one configuration parameter of the DC motor (130); and b. The processor (125) is further operable to set the at least one configuration parameter corresponding to the identified DC motor (130).

10. A method of identifying a DC motor (130) for an x-ray imaging device (10), the method comprising the steps of: a. outputting a modulated DC voltage from a motor controller (120) to the DC motor (130), wherein the modulated DC voltage does not cause rotation of the DC motor (130); b. measuring the voltage or current provided to the DC motor (130) using the motor controller (120) as the modulated DC voltage is output; as well as c. Identifying the DC motor (130) based on the voltage or current provided to the DC motor (130).

11. The method according to claim 10, further comprising the steps of: a. disconnecting a first voltage source (V1) from a plurality of electronic switching devices (150A, 150B, 150C, 150D), wherein the plurality of electronic switching devices (150A, 150B, 150C, 150D) selectively provide the modulated DC voltage to the DC motor (130); as well as b. Connecting a second voltage source (V2) to the plurality of electronic switching devices (150A, 150B, 150C, 150D).

12. The method according to claim 10, wherein the step of outputting the modulated DC voltage further comprises the following steps: a. selectively enabling a first pair of switching devices (150A, 150D) to output a DC voltage having a first polarity to the DC motor (130), and b. Selectively enabling a second pair of switching devices (150B, 150C) to output a DC voltage having a second polarity to the DC motor (130), the second polarity being opposite to the first polarity.

13. The method of claim 10, further comprising an initial step of charging a capacitor (C1) from a reference voltage (V2) prior to outputting the modulated DC voltage, wherein: a. The step of outputting the modulated DC voltage selectively connects the capacitor (C1) to the DC motor, and b. The step of measuring the voltage measures the voltage across the capacitor (C1).

14. The method of claim 10, wherein the step of identifying the DC motor (130) further comprises comparing the voltage or the current measured through the DC motor (130) with a value in a lookup table (129) stored in a memory (127) of the motor controller (120).

15. The method of claim 10, further comprising the step of setting at least one configuration parameter corresponding to the identified DC motor (13), wherein the at least one configuration parameter is stored in a memory (127) of the motor controller (120).

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