Radiographic imaging device, method of operating the radiographic imaging device, and operating program for the radiographic imaging device.

Abstract

This invention provides a radiography apparatus, an operating method for the radiography apparatus, and an operating program for the radiography apparatus that can improve the accuracy of self-position estimation compared to conventional methods when performing driving control related to an autonomous driving mechanism. [Solution] The radiography apparatus is a radiography apparatus used for radiography, comprising: a radiation source or a radiation image detection device; an autonomous driving mechanism including an environmental information sensor that acquires information about the surrounding environment; and a processor that controls the driving mechanism, the processor capable of controlling the frequency of information acquisition from the environmental information sensor according to the driving state of the driving mechanism.

Description

[Technical Field]

[0001] The technique of the present disclosure relates to a radiation imaging apparatus, an operation method of a radiation imaging apparatus, and an operation program for a radiation imaging apparatus. [Background Art]

[0002] In medical practice, radiation imaging apparatuses having a travel mechanism are known. As such a radiation imaging apparatus, for example, there is a radiation generator in which a main body portion having a radiation source that emits radiation toward a subject is mounted on a cart portion having wheels. For example, the radiation generator is used for so-called round imaging, in which imaging of a patient as a subject is performed while moving around hospital rooms.

[0003] Patent Document 1 describes a manually travelable radiation generator equipped with a camera that captures images of the surrounding environment. In Patent Document 1, manual travel to a target position such as the side of a supine imaging table (bed) on which an electronic cassette is placed is assisted by, for example, notifying an operator such as a medical radiographer of a route that avoids obstacles captured by the camera. [Prior Art Document] [Patent Document]

[0004] [Patent Document 1] International Publication No. 2017 / 043040 [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] The inventors are examining adopting a SLAM method that causes autonomous travel to a target position using, for example, SLAM (Simultaneous Localization and Mapping) technology in such a travel-type radiation imaging apparatus. If autonomous travel can be implemented, it becomes possible to further reduce the burden on the operator.

[0006] SLAM (Simultaneous Localization and Mapping) is a technology that performs the creation of a map by recognizing the surrounding environment and the estimation of the vehicle's own position based on that map in parallel. For example, a camera is used as an environmental information sensor to acquire information about the surrounding environment. The processor that performs the driving control related to the driving mechanism repeatedly updates the map of the surrounding environment and estimates the vehicle's own position on the map based on the images acquired by the camera. Accuracy of the self-position estimation is important in order to achieve precise driving control to the target position.

[0007] The camera acquires multiple images according to the frame rate. The frame rate determines the frequency of information acquisition regarding the environment. The processor detects the amount of movement of the driving mechanism from the amount of change between multiple images acquired continuously according to the frame rate and performs driving control by estimating its own position. In driving control, if the amount of change in images per unit time is large, and the frame rate is too low, the amount of change between images becomes too large, which can cause the search for the self-position to take a long time and reduce the estimation accuracy. On the other hand, if the amount of change in images per unit time is small, and the frame rate is too high, the amount of change in images per unit time becomes too small, which can lead to misjudgments, such as incorrectly determining that the vehicle is stopped even though it is moving only slightly.

[0008] Thus, in vehicle control, if the frequency of information acquisition, such as the frame rate, is kept constant, the accuracy of self-position estimation may decrease.

[0009] The technology disclosed herein provides a radiography apparatus, a method for operating the radiography apparatus, and an operating program for the radiography apparatus that can improve the accuracy of self-position estimation compared to conventional methods when performing driving control related to an autonomous driving mechanism. [Means for solving the problem]

[0010] The technology disclosed herein is a radiography apparatus used for radiography, comprising: a radiation source or a radiation image detection device; an autonomous driving mechanism including an environmental information sensor for acquiring information about the surrounding environment; and a processor for controlling the driving mechanism, the processor capable of controlling the frequency of information acquisition from the environmental information sensor according to the driving state of the driving mechanism.

[0011] The driving state may include at least one of the direction of movement and the speed of movement.

[0012] The driving states include straight-line movement where the direction of movement does not change, and rotational movement where the direction of movement changes. Straight-line movement may include forward / backward movement, lateral movement, and diagonal movement.

[0013] The processor may acquire information more frequently in the case of rotational movement than in the case of linear movement.

[0014] The processor may acquire information more frequently when moving horizontally or diagonally than when moving forward or backward.

[0015] The processor may acquire information more frequently when rotational and linear movement are performed in parallel than when only linear movement is performed.

[0016] The processor may control the travel mechanism so that the final position adjustment to the target position is a straight-line movement.

[0017] The faster the processor moves, the more frequently it may retrieve information.

[0018] The processor may acquire fixed-point images representing the surrounding environment captured by a fixed-point camera installed at a fixed location, and perform driving control based on environmental information acquired from environmental information sensors and the fixed-point images.

[0019] An environmental information sensor is a camera that captures images of the surrounding environment, and the information acquisition frequency may be the frame rate.

[0020] The radiation generator may be a radiation generator that includes a radiation source.

[0021] An operating method for a radiation imaging apparatus according to the present disclosure, which is used for radiation imaging, the radiation imaging apparatus including a radiation source or a radiation image detection apparatus, an autonomously drivable traveling mechanism including an environmental information sensor that acquires surrounding environmental information, and a processor that controls the traveling mechanism, the method comprising controlling, by the processor, an information acquisition frequency of the environmental information sensor in accordance with a traveling state of the traveling mechanism.

[0022] An operating program for a radiation imaging apparatus according to the present disclosure, which is used for radiation imaging, the radiation imaging apparatus including a radiation source or a radiation image detection apparatus, an autonomously drivable traveling mechanism including an environmental information sensor that acquires surrounding environmental information, and a processor that controls the traveling mechanism, the program causing the processor to execute a process of controlling an information acquisition frequency of the environmental information sensor in accordance with a traveling state of the traveling mechanism.

Effects of the Invention

[0023] According to the technology of the present disclosure, when performing traveling control related to an autonomously drivable traveling mechanism, the accuracy of self-localization estimation can be improved compared to conventional techniques.

Brief Description of Drawings

[0024] [Figure 1] It is a diagram showing a state of supine position imaging using a radiation imaging system. [Figure 2] It is a diagram showing a state of standing position imaging using a radiation imaging system. [Figure 3] It is a diagram showing a radiation generator with a radiation source in an accommodation position. [Figure 4] It is a block diagram showing an electrical configuration of the radiation generator. [Figure 5] It is a diagram showing how the radiation generator travels from a standby position toward a first target position in supine position imaging and stops at the first target position. [Figure 6]This diagram shows the radiation generator moving from its standby position towards the second target position in standing imaging, and then stopping at the second target position. [Figure 7] This diagram shows the processing of each processing unit in the processor related to driving control. [Figure 8] This figure, following Figure 7, shows the processing of each processing unit in the processor related to driving control. [Figure 9] This diagram shows the processing of each processing unit in the processor related to alignment control. [Figure 10] This figure shows the processing during the training phase of the cassette contour extraction model. [Figure 11] This diagram shows the alignment control process. [Figure 12] This is a diagram showing the alignment support screen. [Figure 13] This diagram shows the details of the shooting control system. [Figure 14] This is a conceptual diagram of frame rate control in vehicle operation control. [Figure 15] This is a diagram illustrating movement in a straight line. [Figure 16] This is a diagram illustrating rotational movement. [Figure 17] This is a diagram illustrating lateral movement. [Figure 18] This figure shows a concrete example of frame rate control. [Figure 19] This is a diagram explaining frame rate. [Figure 20] This graph shows the relationship between movement speed and frame rate. [Figure 21] This is a conceptual diagram illustrating how to control the frame rate according to movement speed. [Figure 22] This diagram shows the final position adjustment. [Figure 23] This figure shows an example of using fixed-point photography images. [Modes for carrying out the invention]

[0025] [First Embodiment] As an example, as shown in Figures 1 and 2, the radiography system 10 comprises a radiation generator 11 and an electronic cassette 12. The radiation generator 11 has a main body 14 having a radiation source 13 that emits radiation R toward the patient P, mounted on a trolley 16 having wheels 15. The radiation R is, for example, X-rays. The radiation generator 11 is equipped with a battery BT (see Figure 4) and can be driven by power supplied from the battery BT. The radiation generator 11 can also be driven by receiving power from a commercial power source via a power cord. The radiation generator 11 is a device used for radiography and is an example of a "radiography device" according to the technology of this disclosure. The trolley 16 is an example of a "travel mechanism" according to the technology of this disclosure. The electronic cassette 12 is an example of a "radiation image detection device" according to the technology of this disclosure.

[0026] The radiation generator 11 is movable within the imaging room RM (see also Figures 5 and 6). The radiation generator 11 is also used for so-called mobile imaging, where images are taken of patients P while moving around the patient rooms. For this reason, the radiation generator 11 is also called a mobile imaging unit. Alternatively, the radiation generator 11 can be used for imaging in the emergency room. Furthermore, the radiation generator 11 can be brought into the operating room and used during surgery.

[0027] The electronic cassette 12 has a configuration in which a sensor panel, which acts as a radiation detector for detecting radiation R, is built into a portable housing. The electronic cassette 12 is powered by a battery and communicates wirelessly with the radiation generator 11. The sensor panel has a detection surface 17 in which multiple pixels are arranged in a matrix and generate a signal charge in response to radiation R or visible light converted from radiation R by a scintillator. The electronic cassette 12 detects the radiation R that is irradiated from the radiation source 13 and passes through the patient P, and outputs a radiation image 18 of the patient P.

[0028] Since the electronic cassette 12 is portable and wireless, it can be used for so-called free radiography, as shown in Figure 1, by placing it on the supine radiography table 19 (under the patient P) installed in the radiography room RM and performing radiography. More specifically, Figure 1 shows the electronic cassette 12 being inserted between the supine radiography table 19 and the patient P to take an image of the patient P lying supine on the supine radiography table 19 (see also Figure 5). Also, as shown in Figure 2, the electronic cassette 12 can be used by housing it in the holder 21 of the standing radiography table 20 installed in the radiography room RM (see also Figure 6). The holder 21 can be raised and lowered vertically relative to the support column 22.

[0029] The main body 14 is rectangular in shape and is erected in the center of the trolley 16. The main body 14 is divided into a front movable part 25 and a rear fixed part 26. The movable part 25 can move up and down relative to the fixed part 26. The fixed part 26 is fixed to the trolley 16.

[0030] The base end of the arm 27 is attached to the movable part 25. More specifically, the arm 27 is divided into a first part to which the base end is attached to the movable part 25, and a second part to which the base end is attached to the first part. The radiation source 13 is attached to the tip of the second part, which is the free end opposite the base end.

[0031] The first part is vertically movable relative to the movable part 25 and is also rotatable relative to the movable part 25. The second part is vertically foldable relative to the first part. Furthermore, the second part is extendable and retractable. The radiation source 13 is rotatable, i.e., pivotable, relative to the second part. By displacing the arm 27 and the radiation source 13 relative to the arm 27, it is possible to adjust the height, horizontal position, and orientation (direction) of the radiation source 13.

[0032] Because the second part is foldable and expandable, the radiation source 13 can move between a shooting preparation position, as shown in Figures 1 and 2, where it is projected toward the patient P and the electronic cassette 12, and a housing position, as shown in Figure 3 as an example, where it is pulled toward the main body 14. The shooting preparation position shown in Figures 1 and 2 is the position when the second part is extended to a predetermined length, for example, half of its maximum length, and folded relative to the first part so that it is parallel to the horizontal direction. The housing position shown in Figure 3 is the position when the second part is shortened to its shortest length and folded as far as possible relative to the first part.

[0033] In Figures 1 and 2, an operation panel 28 is provided on the upper surface of the fixed part 26. The operation panel 28 is, for example, composed of a touch panel display and has the function of displaying information in addition to operation functions. The operation panel 28 is operated by an operator OP, such as a radiological technologist. The operator OP sets the irradiation conditions of radiation R through the operation panel 28. The operator OP also checks the radiation image 18 through the operation panel 28. Furthermore, as will be described later, the operator OP performs relative positioning (also called positioning) between the radiation source 13 and the electronic cassette 12 by referring to the positioning support screen 91 (see Figure 12) displayed on the operation panel 28.

[0034] Furthermore, the fixed part 26 is equipped with an irradiation switch (not shown). The irradiation switch is used by the operator OP to instruct the start of radiation irradiation. An extension cable is connected to the irradiation switch, and it can be detached from the fixed part 26 for use.

[0035] The radiation source 13 includes a radiation tube 30 and an irradiation field limiter 31. The radiation tube 30 generates radiation R. The radiation tube 30 is equipped with a filament, a target, a grid electrode, etc. (all not shown). A tube voltage is applied between the filament, which is the cathode, and the target, which is the anode, from a voltage generator (not shown) built into the fixed part 26. The filament emits thermionic electrons toward the target in accordance with the applied tube voltage. The target emits radiation R in response to collisions with thermionic electrons emitted from the filament. The grid electrode is placed between the filament and the target and changes the flow rate of thermionic electrons from the filament toward the target in accordance with the voltage applied from the voltage generator. This flow rate of thermionic electrons from the filament toward the target is called the tube current. The tube voltage and tube current are set in the radiation source 13 as irradiation conditions, along with the irradiation time.

[0036] The irradiation field limiter 31, also known as a collimator, limits the irradiation field of the radiation R generated from the radiation tube 30. The irradiation field limiter 31 has a configuration in which, for example, four shielding plates made of lead or the like are arranged on each side of a rectangle, and a rectangular exit aperture that transmits radiation is formed in the center. The irradiation field limiter 31 changes the size of the exit aperture by changing the position of each shielding plate, thereby changing the irradiation field of the radiation R.

[0037] A camera 32 is attached to the radiation source 13. The camera 32 is used to assist in aligning the radiation source 13 with the electronic cassette 12. The camera 32 incorporates a visible light-sensitive image sensor, such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge-coupled Device) image sensor. The camera 32 captures moving images. The camera 32 is an example of an "environmental information sensor" related to the technology of this disclosure.

[0038] There are a total of four wheels 15, located on the front, rear, left, and right sides of the bogie 16. In other words, the bogie 16 is a four-wheeled type. Each wheel 15 is a swivel type, for example, that rotates around a pivot axis that extends in the height direction (also called the vertical direction) perpendicular to the axis of rotation when the vehicle is moving. The radiation generator 11 autonomously moves using this bogie 16.

[0039] Here, autonomous driving refers to autonomously driving toward a set target location while recognizing the surrounding environment using environmental information sensors and estimating its own position. The target location is pre-set to beside the supine imaging table 19 shown in Figure 1, and facing the standing imaging table 20 shown in Figure 2. The radiation generator 11 uses a SLAM method, which utilizes SLAM technology, as one of the driving control methods to achieve autonomous driving.

[0040] A camera 33 is provided on the trolley section 16. The camera 33 is used to support the autonomous movement of the main body section 14. The camera 33 photographs the area in front of the trolley section 16. Like the camera 32, the camera 33 incorporates a visible light-sensitive image sensor and captures moving images. Like the camera 32, the camera 33 is an example of an "environmental information sensor" related to the technology disclosed herein. The main body section 14, and by extension the radiation generator 11, can be driven not only autonomously but also manually by an operator OP.

[0041] Figure 4 is a block diagram showing an example of the electrical configuration of the radiation generator 11. The processor 40 comprehensively controls the entire radiation generator 11. The processor 40 consists, for example, of a CPU (Central Processing Unit) and memory such as RAM (Random Access Memory), and functions as various processing units by loading and executing various programs into memory. Specifically, the processor 40 performs travel control, positioning control, and imaging control. Travel control is the control related to the autonomous travel of the trolley section 16. Positioning control is the control related to the positioning of the radiation source 13 and the electronic cassette 12, as described above. Imaging control includes the control of radiation R irradiation by the radiation source 13 and the output control of the radiation image 18 by the electronic cassette 12.

[0042] The storage 41 consists of non-volatile memory such as a hard disk drive or a solid-state drive. The storage 41 stores an operating program 42 and control data 43. The operating program 42 is an example of an "operating program for a radiation generator" related to the technology of this disclosure. The control data 43 includes data for driving control, data for positioning control, and data for imaging control. The data for driving control includes map data 73 (see Figure 8) created using the SLAM method. The data for positioning control includes a cassette recognition model 86 (see Figure 9) for recognizing the electronic cassette 12. The data for imaging control includes an irradiation condition table in which irradiation conditions for each imaging area are registered.

[0043] The processor 40 is connected to the operation panel 28, the communication interface 50, the travel actuator 51, the alignment actuator 52, and the radiation source position detection sensor 53. The processor 40 controls the display of various screens on the operation panel 28. The processor 40 also receives various operation instructions from the operator OP through the operation panel 28 and executes various controls according to the operation instructions. The communication interface 50 is, for example, a wireless communication interface and is responsible for wireless communication with the electronic cassette 12.

[0044] The travel actuator 51 includes a motor for rotating the wheels 15 under the control of the processor 40, and a motor for turning them. The travel actuator 51 also includes a travel state detection sensor 51A that measures the rotation direction and amount of rotation of the wheels 15, as well as the turning direction and turning angle. The travel state detection sensor 51A is, for example, a rotary encoder or a gyro sensor, or a combination of several such sensors. The travel state detection sensor 51A outputs the measured values ​​to the processor 40. Based on the measured values ​​from the travel state detection sensor, the processor 40 detects the amount of movement of the trolley 16, as well as the travel speed and direction of movement, and other travel conditions.

[0045] The running status can be used for various purposes. For example, the processor 40 can determine whether the operating status of the running mechanism, including the bogie section 16, is normal or not based on the running status detection sensor 51A.

[0046] Furthermore, while the processor 40 uses the SLAM method as one of the autonomous driving control methods, it is also possible to execute driving control methods other than SLAM by using the driving state detection sensor 51A. As will be described later, the SLAM method performs autonomous driving by estimating the self-position and creating map data based on surrounding environmental information. As an example of a driving control method other than SLAM, there is a method that performs autonomous driving by estimating the self-position based on the amount of movement detected by the driving state detection sensor 51A without creating map data. Of course, such driving control methods tend to have increasing errors as the driving distance increases compared to the SLAM method, so they are unsuitable for long driving distances. However, they can be effective when used as a supplement, such as when the driving distance is short.

[0047] The alignment actuator 52 includes, under the control of the processor 40, a motor for raising and lowering the movable part 25, a motor for raising and lowering the arm 27, a motor for bending the second part of the arm 27, a motor for extending and retracting the second part, and a motor for rotating the radiation source 13 relative to the second part.

[0048] The radiation source position detection sensor 53 measures the vertical direction and amount of vertical movement of the arm 27 relative to the movable part 25, the bending direction and amount of bending of the second part of the arm 27 relative to the first part, the extension and retraction direction and amount of extension and retraction of the second part, and the rotation direction and amount of rotation of the radiation source 13 relative to the second part. The radiation source position detection sensor 53 is, for example, a rotary encoder, a potentiometer, or a gyro sensor, or a combination of several of these sensors. The radiation source position detection sensor 53 outputs the measured values ​​to the processor 40. The processor 40 derives the position and orientation of the radiation source 13 based on the measured values ​​of the radiation source position detection sensor 53.

[0049] Since the radiation generator 11 is capable of autonomous movement, it can automatically move to a designated location. As an example, as shown in Figures 5 and 6, a standby position HP for the radiation generator 11 is provided in a corner of the imaging room RM. At the standby position HP, the radiation source 13 is housed. At the standby position HP, charging of the battery BT, transfer of imaging orders from the Radiology Information System (RIS), and setting of irradiation conditions are performed. The standby position HP occupies an area that is the same size as the radiation generator 11, or slightly larger.

[0050] In the imaging room RM, a first target position TP1 (see Figure 5) for the radiation generator 11 during supine imaging and a second target position TP2 (see Figure 6) for the radiation generator 11 during upright imaging are set. The first target position TP1 is located beside the supine imaging table 19, more specifically, directly opposite the center of one of the longer sides of the supine imaging table 19. The second target position TP2 is located directly opposite the upright imaging table 20, at a distance equal to the SID (Source to Image Distance) required for upright imaging. In the following, the first target position TP1 and the second target position TP2 may be collectively referred to as target position TP.

[0051] During supine imaging, the radiation generator 11 travels, for example, from the standby position HP towards the first target position TP1, and stops when its own position PS (see Figure 8) reaches the first target position TP1 (see Figure 5). Similarly, during upright imaging, the radiation generator 11 travels from the standby position HP towards the second target position TP2, and stops when its own position PS reaches the second target position TP2. Although not shown in the illustration, the radiation generator 11 can also travel from the first target position TP1 to the second target position TP2 in order to perform upright imaging after supine imaging. Furthermore, the radiation generator 11 may also travel from the second target position TP2 to the first target position TP1 in order to perform supine imaging after upright imaging. During such autonomous travel to target positions TP, the radiation source 13 remains in its storage position.

[0052] Autonomous driving to the target position TP is initiated, for example, by an instruction from an operator OP via the control panel 28. Alternatively, the system may be configured to allow the start of autonomous driving to be initiated via a remote controller, in addition to or instead of the control panel 28.

[0053] In the SLAM method, autonomous driving is achieved by continuously acquiring images representing the surrounding environment and tracking the movement of feature points within the images through image analysis to estimate the vehicle's own position. Specifically, as shown in Figures 7 and 8, upon activation of the operation program 42, the processor 40 functions as an image acquisition unit 60, a feature point extraction unit 61, a self-position estimation / map data creation unit 62, and a driving control unit 63.

[0054] The image acquisition unit 60 sequentially acquires images 70 of the surrounding environment of the radiation generator 11 (hereinafter referred to as "driving control images") captured by the camera 33. The frame rate, which is the frequency at which the driving control images 70 are acquired, is controlled according to the driving state of the driving mechanism of the radiation generator 11, as will be described later. After performing preprocessing such as noise reduction and distortion correction on the driving control images 70, the image acquisition unit 60 outputs the driving control images 70 to the feature point extraction unit 61.

[0055] The feature point extraction unit 61 uses algorithms such as ORB (Oriented FAST (Features from Accelerated Segment Test) and Rotated BRIEF (Binary Robust Independent Elementary Features)) or SURF (Speeded-Up Robust Features) to extract corners and other features of structures in the surrounding environment captured in the driving control image 70 as feature points FP. The feature point extraction unit 61 outputs the feature point extraction results 71 of the feature points FP to the self-position estimation and map data creation unit 62. Although not shown in the diagram, the feature point extraction unit 61 also stores the feature point extraction results 71 in the storage 41. The feature point extraction results 71 are a pair of the coordinates and feature vectors of each feature point FP.

[0056] The self-position estimation and map data creation unit 62 estimates the self-position PS of the radiation generator 11 and creates map data 73 of the surrounding environment. The self-position estimation and map data creation unit 62 receives the feature point extraction results 71 from the feature point extraction unit 61. In addition, the self-position estimation and map data creation unit 62 receives feature point extraction results 71P from multiple past frames (hereinafter referred to as extraction results (past)) and map data 73P from multiple past frames (hereinafter referred to as map data (past)).

[0057] The feature point extraction results (past data) 71P and map data (past data) 73P are stored in storage 41 as data for driving control of the control data 43. The feature point extraction results 71 and map data 73 that make up the feature point extraction results (past data) 71P and map data (past data) 73P consist of, for example, tens to hundreds of frames. The feature point extraction results (past data) 71P and map data (past data) 73P include feature point extraction results 71 and map data 73 that are considered to play an important role in estimating the self-position PS and creating the map data 73. Such feature point extraction results 71 and map data 73 are, for example, feature point extraction results 71 and map data 73 obtained every certain distance traveled. Also, for example, feature point extraction results 71 and map data 73 obtained when there has been a large change in viewpoint from the previous frame. Furthermore, for example, feature point extraction results 71 and map data 73 obtained when more than a set amount of new feature points FP have been extracted.

[0058] The self-localization and map data creation unit 62 compares the feature points FP from the feature point extraction result 71 from the feature point extraction unit 61 with the feature points FP from the feature point extraction result (past data) 71P. In this process, the self-localization and map data creation unit 62 refers to the feature vector of each feature point FP. More specifically, it recognizes feature points FP from the feature point extraction result 71 from the feature point extraction unit 61 and feature points FP from the feature point extraction result (past data) 71P where the distance (Euclidean distance, etc.) of the feature vectors is less than a threshold as the same feature point FP. Based on this comparison result of feature points FP and the map data (past data) 73P, the self-localization and map data creation unit 62 estimates the self-localization PS. Furthermore, the self-position estimation and map data creation unit 62 creates new map data 73 (updates map data 73) based on the feature point extraction results 71 from the feature point extraction unit 61, the feature point extraction results (past) 71P, the map data (past) 73P, and the estimation results 72. In this way, the self-position estimation and map data creation unit 62 performs the estimation of the self-position PS and the creation of map data 73 in parallel during the process of the radiation generator 11 autonomously moving.

[0059] The self-position estimation and map data creation unit 62 outputs the self-position estimation result 72 of the self-position PS to the driving control unit 63. The driving control unit 63 controls the driving of the driving actuator 51 to set the self-position PS as the target position TP. Although not shown in the diagram, the self-position estimation and map data creation unit 62 also stores the map data 73 in the storage 41. Specifically, the map data 73 is 3D data of the imaging room RM, including structures such as the supine imaging table 19 and the standing imaging table 20. The standby position HP and the target position TP are also registered in the map data 73.

[0060] As an example, as shown in Figure 9, the processor 40 functions as a cassette contour extraction unit 80, a source position and orientation derivation unit 81, and an alignment control unit 82.

[0061] The cassette contour extraction unit 80 receives sequential images 85 (hereinafter referred to as alignment control images) 85, which include the patient P and the electronic cassette 12, captured by the camera 32. The camera 32 is attached to the radiation source 13. Therefore, when the self-position PS of the radiation generator 11 is set as the target position TP and the radiation source 13 is set as the preparation position for imaging, the alignment control image 85 will show the patient P and the electronic cassette 12. In Figure 9, supine imaging is shown as an example, so the supine imaging table 19 is also shown in the alignment control image 85. It is assumed that the alignment of the patient P and the electronic cassette 12 has been completed by the operator OP before alignment control.

[0062] The cassette contour extraction unit 80 extracts the contour OLC of the electronic cassette 12 from the alignment control image 85 using the cassette recognition model 86. The contour OLC reveals the center CC (see Figure 11) of the detection surface of the electronic cassette 12. The cassette contour extraction unit 80 outputs the cassette contour extraction result 87 to the alignment control unit 82. Here, the contour OLC is exemplified as a contour that follows all sides of the electronic cassette 12, but it is not limited to this. The four corners of the electronic cassette 12 may also be extracted as contours. The alignment control image 85 is an example of "output data" related to the technology of this disclosure.

[0063] The cassette recognition model 86 is a pre-trained model, for example, composed of a convolutional neural network, which is trained to output a cassette contour extraction result 87 when an alignment control image 85 is input. The cassette recognition model 86 is stored in the storage 41 as alignment control data for the control data 43.

[0064] As an example, as shown in Figure 10, during the learning phase, the cassette recognition model 86 is given training data 90. The training data 90 consists of a training alignment control image 85L and ground truth data 87CA. The training alignment control image 85L shows an electronic cassette 12. The ground truth data 87CA is data annotated with the contour OLC of the electronic cassette 12 shown in the training alignment control image 85L, and is, so to speak, data for checking the answer.

[0065] The cassette recognition model 86 receives a training alignment control image 85L as input. The cassette recognition model 86 outputs a training cassette contour extraction result 87L in response to the input of the training alignment control image 85L. Based on this training cassette contour extraction result 87L and the ground truth data 87CA, a loss calculation is performed on the cassette recognition model 86 using a loss function. Then, based on the result of the loss calculation, various coefficients of the cassette recognition model 86 (such as the coefficients of the convolutional layer filters) are updated, and the cassette recognition model 86 is updated according to the update settings.

[0066] In the learning phase of the cassette recognition model 86, the above series of processes—inputting the learning alignment control image 85L into the cassette recognition model 86, outputting the learning cassette contour extraction result 87L from the cassette recognition model 86, loss calculation, update settings, and updating the cassette recognition model 86—are repeated while the learning data 90 is exchanged. The repetition of the above series of processes ends when the extraction accuracy of the learning cassette contour extraction result 87L reaches a predetermined set level. The cassette recognition model 86, whose extraction accuracy has reached the set level, is stored in the storage 41 and used by the cassette contour extraction unit 80. Alternatively, learning may be terminated after the above series of processes has been repeated a set number of times, regardless of the extraction accuracy of the learning cassette contour extraction result 87L.

[0067] The radiation source position and orientation derivation unit 81 derives the position and orientation of the radiation source 13 based on the measurement values ​​of the radiation source position detection sensor 53. The radiation source position and orientation derivation unit 81 outputs the derivation result 88 to the alignment control unit 82. The derivation result 88 consists of the coordinates in the alignment control image 85 of the irradiation center RC of radiation R (see Figure 11) and the coordinates in the alignment control image 85 of the rectangular frame F (see Figure 11) that indicates the orientation of the radiation source 13. Since the positional relationship between the radiation source 13 and the camera 32 is known, the coordinates in the alignment control image 85 of the irradiation center RC and frame F can be easily converted from the measurement values ​​of the radiation source position detection sensor 53.

[0068] The alignment control unit 82 controls the drive of the alignment actuator 52 in order to align the radiation source 13 and the electronic cassette 12 directly. More specifically, as shown in Figure 11 as an example, if the orientation of the radiation source 13 is tilted relative to the electronic cassette 12, the alignment control unit 82 rotates the radiation source 13 to correct the tilt. Also, if the irradiation center RC of the radiation R and the center CC of the detection surface of the electronic cassette 12 are misaligned, the alignment control unit 82 moves the radiation source 13 to correct the misalignment. Note that the tilt may be corrected after correcting the misalignment between the irradiation center RC of the radiation R and the center CC of the detection surface of the electronic cassette 12. Furthermore, Figure 11 illustrates the case where the orientation of the radiation source 13 is tilted around the normal to the detection surface of the electronic cassette 12, but it is not limited to this. Even if the orientation of the radiation source 13 is tilted around an axis along the long side or short side of the detection surface of the electronic cassette 12, the alignment control unit 82 rotates the radiation source 13 to correct the tilt.

[0069] As shown in Figure 12, the alignment control unit 82 displays an alignment support screen 91 on the operation panel 28, which shows the alignment status of the radiation source 13 and the electronic cassette 12. The alignment support screen 91 displays an alignment control image 85. The operator OP can check the alignment status of the radiation source 13 and the electronic cassette 12 through the alignment support screen 91.

[0070] Furthermore, although the example described uses the alignment control unit 82 to automatically align the radiation source 13, the alignment of the radiation source 13 may also be performed manually by the operator OP. Manual operation may include, for example, the operator OP inputting operation instructions to the alignment actuator 52 via operation buttons, or the operator OP directly moving the radiation source 13. Naturally, if the radiation source 13 is displaced by such manual operation by the operator OP, the alignment control image 85 in the alignment support screen 91 is updated. This allows the operator OP to check the current state of alignment through the alignment support screen 91.

[0071] As shown in Figure 13, the processor 40 also performs imaging control. Imaging control includes, for example, imaging order registration, irradiation control, and output control. Imaging order registration is the process of registering information such as patient information, imaging purpose, and imaging site based on imaging orders received from the RIS or the like.

[0072] Irradiation control includes irradiation condition setting and drive control. Irradiation condition setting involves setting irradiation conditions, including the tube voltage, tube current, and irradiation time of the radiation generated by the radiation source 13. Drive control is the drive control of the radiation source 13 according to the set irradiation conditions, and drive control includes synchronization control of the irradiation timing of the radiation source 13 and the image detection timing of the electronic cassette 12.

[0073] Output control includes the process of receiving the radiographic image 18 detected by the electronic cassette 12, image correction which applies various corrections such as offset correction, sensitivity correction, and defect correction to the received radiographic image 18, and image display which displays the corrected radiographic image 18 on the operation panel 28. Furthermore, output control includes re-shooting determination and image transfer. Re-shooting determination is the process of determining whether the acquired radiographic image 18 can be used for diagnosis in light of the purpose of acquisition, and determining whether re-shooting is necessary. Image transfer is the process of transferring the acquired radiographic image 18 to the image server.

[0074] Furthermore, as shown in Figure 14, the processor 40 has a function to control the frame rate of the camera 33 according to the running state of the running mechanism including the trolley section 16. The camera 33 is a camera that captures the surrounding environment, and the frame rate is the frequency at which the camera 33 acquires the running control images 70. Here, the running control images 70 are an example of "surrounding environment information" related to the technology of this disclosure, and the camera 33 is an example of an "environmental information sensor" related to the technology of this disclosure. Furthermore, the frame rate is an example of "information acquisition frequency" related to the technology of this disclosure.

[0075] The processor 40 transmits a frame rate as an operating condition to the camera 33 according to the driving state acquired from the driving state detection sensor 51A. When the camera 33 receives the frame rate, it captures a video image at the received frame rate. The driving state includes the direction of movement and the amount of movement. More specifically, the driving state includes straight-line movement where the direction of movement does not change, and rotational movement where the direction of movement changes. Furthermore, straight-line movement includes forward / backward movement, lateral movement, and diagonal movement. Forward / backward movement is linear movement along the front-rear direction of the trolley 16, and lateral movement is linear movement along the left-right direction of the trolley 16 which is perpendicular to the front-rear direction. Diagonal movement is linear movement along a direction between the front-rear direction and lateral movement, for example, a 45-degree angle when the front-rear direction is 0° and the left-right direction is 90°. The reason for controlling the frame rate according to such driving states is as follows.

[0076] Figures 15 to 17 schematically show how the travel control images 70 acquired sequentially change when the radiation generator 11, including the trolley section 16, moves. Figure 15 is an example of straight-line movement, Figure 16 is an example of rotational movement, and Figure 17 is an example of lateral movement. In all of Figures 15 to 17, the initial state of the radiation generator 11 (bottom row in each of Figures 15 to 17) is assumed to be a straight corridor with walls on both sides extending in front of the radiation generator 11. Figures 15 to 17 show how each travel control image 70 acquired continuously by the camera 33 changes according to the travel state of the radiation generator 11 from its initial state.

[0077] As shown in Figure 15, when the radiation generator 11 moves in a straight line forward from its initial state (i.e., forward), it moves along a straight corridor. In this case, the viewpoint of the camera 33 only moves along the direction in which the corridor extends, so the amount of change in the travel control images 70 continuously acquired by the camera 33 is considered to be relatively small. In contrast, as shown in Figure 16, when the radiation generator 11 rotates and changes direction from its initial state, the orientation of the viewpoint of the camera 33 that photographs the corridor changes, so the amount of change in the travel control images 70 continuously acquired by the camera 33 is considered to be larger compared to the forward movement case shown in Figure 15. Also, as shown in Figure 17, when the radiation generator 11 moves laterally from its initial state, the viewpoint of the camera 33 moves laterally perpendicular to the direction in which the corridor extends, so the amount of change in the travel control images 70 continuously acquired by the camera 33 is considered to be larger compared to the forward movement case shown in Figure 15.

[0078] As described above, in the SLAM method, the processor 40 extracts feature points FP from multiple continuously acquired driving control images 70 and performs self-localization (including updating map data 73) by tracking the movement of the feature points FP. Therefore, if the frame rate is kept constant regardless of the driving conditions shown in Figures 15 to 17, there is a risk that the accuracy of self-localization will decrease.

[0079] This is because, in the case of rotational movement as shown in Figure 16, the amount of image change is relatively larger compared to linear movement. Therefore, the lower the frame rate (i.e., the longer the image acquisition interval), the greater the amount of movement of feature points FP (see Figures 7 and 8) in the multiple images acquired continuously as driving control images 70. If the amount of movement of feature points FP is large, the search time increases, and if feature points FP cannot be found within the specified time, self-position estimation cannot be performed accurately, and the estimation accuracy decreases. On the other hand, in the case of linear movement in the forward and backward direction as shown in Figure 15, if the frame rate is the same as in Figure 16, the amount of change in the multiple images acquired continuously as driving control images 70 is small. Therefore, even if the frame rate is low (i.e., the image acquisition interval is long), the search time for feature points FP is shorter compared to the rotational movement shown in Figure 16. In the case of lateral movement as shown in Figure 17, the amount of image change is considered to be an intermediate amount between the forward and backward movement shown in Figure 15 and the rotational movement shown in Figure 16. Although not shown in the diagram, in addition to forward / backward and lateral movement, linear movement also includes diagonal movement as described above. The amount of change in the image during this diagonal movement is also thought to be an intermediate amount, similar to that during lateral movement.

[0080] However, a higher frame rate isn't always better, as there are drawbacks to high frame rates. For example, if the frame rate is too high when the amount of image change is small, as shown in Figure 15 for forward and backward movement, the movement of feature points (FP) may be too small, leading to misidentification where movement is incorrectly detected. In this case, lowering the frame rate to some extent to increase the movement of feature points (FP) is likely to reduce the likelihood of misidentification.

[0081] Therefore, in the radiation generator 11, the processor 40 controls the frame rate according to the driving state, for example, based on the table 92 shown in Figure 18. In table 92, FR1, FR2, and FR3 are the respective frame rate values. As also shown in Figure 19, the higher the frame rate, the shorter the image acquisition interval shown in T1 to T3. Among FR1 to FR3, FR3 is the highest, FR1 is the lowest, and FR2 is in between. In table 92, for forward and backward movement within linear movement, the lowest FR1 is set, and for rotational movement, the highest FR3 is set. For lateral and diagonal movement other than forward and backward movement within linear movement, an intermediate FR2 is set. Also, when rotational movement and linear movement are performed in parallel, the same FR3 as for rotational movement is set. As a specific value for FR1 to FR3, for example, FR1 is 1 FPS (Frames Per Second), FR3 is 4 FPS, and FR2 is an intermediate 2 FPS. Using FR1 as the baseline, FR2 is twice the value, and FR3 is four times the value.

[0082] As shown in the flowchart of Figure 18, when the drive control is initiated, the processor 40 controls the frame rate according to the driving state while referring to Table 92. This frame rate control is continued until the drive control is completed. As a result, the radiation generator 11 acquires drive control images 70 at appropriate intervals according to the driving state, thereby improving the accuracy of self-localization.

[0083] As described above, the radiation generator 11, which is an example of a radiography apparatus according to the technology disclosed herein, includes a processor 40 that controls a travel mechanism including a trolley 16, and the processor 40 controls the frame rate (an example of information acquisition frequency) of the camera 33 (an example of an environmental information sensor) according to the travel state of the travel mechanism. As a result, autonomous travel control can be performed more appropriately compared to conventional methods.

[0084] The technology disclosed herein is particularly effective in radiography equipment, with the radiation generator 11 being an example, as described below. Specifically, the SLAM method is also used, for example, in robots that transport goods in warehouses. In such warehouse applications, the decrease in the accuracy of self-position estimation described above can sometimes be addressed by providing markers such as line markers along the movement path of the traveling mechanism. That is, if markers such as line markers are provided along the movement path of the traveling mechanism, the line markers captured in the image will serve as clues when performing self-position estimation, and it is thought that the estimation accuracy will not decrease even if the frame rate is kept constant. Furthermore, the movement paths of traveling mechanisms in warehouses are often kept relatively orderly, and it is thought that such environmental factors make it easier to ensure the accuracy of self-position estimation.

[0085] In contrast, in environments such as radiography rooms (RMs) where radiography equipment is used, various medical devices are placed along the movement paths of the travel mechanism, making it difficult to install markers such as line markers. Furthermore, the layout of medical equipment in radiography rooms (RMs) changes daily, making it often difficult to ensure a consistent and orderly movement path. Therefore, when using the SLAM method with radiography equipment, measures such as using line markers to counteract the decrease in the accuracy of self-position estimation are difficult to implement.

[0086] The technology disclosed herein is particularly effective in radiography equipment because it can suppress a decrease in the accuracy of self-localization by appropriately controlling the frame rate, even in environments such as radiography room RMs where line markers are not provided.

[0087] Furthermore, the radiation generator 11 distinguishes between linear movement, where the direction of movement does not change, and rotational movement, where the direction of movement changes, based on the movement state. Linear movement is further divided into forward / backward movement, lateral movement, and diagonal movement. This makes it possible to set an appropriate frame rate (an example of information acquisition frequency) according to each distinction in movement state, thereby improving the accuracy of self-position estimation compared to cases where such distinctions are not made.

[0088] Specifically, as shown in Table 92 of Figure 18 as an example, the processor 40 sets the frame rate for rotational movement (FR3) higher than the frame rate for linear movement (FR1). Furthermore, the processor 40 sets the frame rate for lateral or diagonal movement (FR2) higher than the frame rate for forward / backward movement (FR1). As mentioned above, the amount of change in multiple images acquired sequentially is thought to increase in the order of forward / backward movement, lateral or diagonal movement, and rotational movement. Therefore, increasing the frame rate in this order is considered appropriate for improving the accuracy of self-localization. Also, in Table 92, the frame rate (FR3) when rotational movement and linear movement are performed in parallel is higher than the frame rate for linear movement only (FR1 and FR2). Since the amount of change in the image increases when rotational movement is included, this frame rate setting is also considered appropriate.

[0089] (Variation 1: Frame rate controlled according to movement speed) Furthermore, as shown in Figure 20, the processor 40 may increase its frame rate as the speed of the moving mechanism increases. Naturally, the faster the speed of movement, the greater the amount of movement of the moving mechanism per unit time. In this case, by increasing the frame rate and shortening the acquisition interval of the movement control images 70, it is possible to suppress the increase in the amount of change between multiple continuously acquired images, thereby improving the accuracy of self-localization.

[0090] (Variation 2: Frame rate controlled according to direction and speed of movement) Furthermore, frame rate control based on movement speed may be combined with movement direction. In other words, frame rate control may be performed considering both movement speed and movement direction. This would allow for more appropriate control of the frame rate according to the driving conditions.

[0091] Figure 21 shows an example of frame rate settings based on both direction and speed of movement. In Figure 21, as described above, the direction of movement is first distinguished as linear movement and rotational movement, and linear movement is further distinguished as forward / backward movement, lateral movement, and diagonal movement. Furthermore, forward / backward movement is further distinguished as forward and backward movement. For each direction of movement, there is a assumed movement speed of the travel mechanism of the radiation generator 11, and in the example of Figure 21, linear movement other than forward is assumed to be 100 [mm / sec]. Rotational movement is assumed to be 10 [degrees / sec]. Based on these movement speeds, the frame rate is set for each direction of movement. Specifically, 0.33 FPS is set for backward movement, and 2 FPS or 3 FPS is set for lateral / diagonal movement. For rotational movement, it is 4 FPS. These frame rate values ​​are higher as the amount of change between images increases, and are based on the same concept as shown in the example of Figure 18.

[0092] In the example shown in Figure 21, for forward movement, the frame rate is controlled by considering not only the direction of movement but also the speed of movement. That is, even for forward movement, two types of speeds are assumed: 300 mm / sec and 100 mm / sec, and the frame rate is controlled according to each speed. Specifically, the frame rate is set to 1 FPS when the speed of movement is 300 mm / sec, and to 0.33 FPS when the speed of movement is 100 mm / sec. This ensures that even for forward movement in the same direction, the frame rate is set lower when the speed of movement is slow.

[0093] One reason why two types of movement speeds are assumed for forward movement is as follows. For example, when moving the radiation generator 11 from the standby position HP shown in Figures 5 and 6 to either the first target position TP1 or the second target position TP2, the movement up to near the target position TP may be done at a relatively fast speed, and then the movement speed may be slowed down as it approaches the target position TP to make final position adjustments to the target position TP. In this case, even if it is forward movement, it is conceivable to slow down the movement speed as a fine-tuning mode for making final position adjustments. In this case, since the movement speed is slower, it is more appropriate to set the frame rate lower accordingly, as described above, in order to improve the accuracy of self-position estimation. Thus, the frame rate may be controlled by considering both the direction of movement and the speed of movement. Note that Figure 21 is just one example, and the frame rate may be set according to both the direction of movement and the speed of movement for movements other than forward movement as well.

[0094] (Variation 3) Furthermore, as shown in Figure 22, the processor 40 may perform travel control so that the final position adjustment to the target position TP is performed as a straight-line movement. As shown in Figure 22, when the radiation generator 11 moves from the standby position HP to the target position TP (second target position TP2 in Figure 22), immediately after starting to move from the standby position HP, it performs rotational movement such as a change of direction, as shown in (1). Then, when the radiation generator 11 approaches the target position TP, specifically when it enters the pre-set proximity range of the target position HP, the radiation generator 11 performs the final position adjustment, as shown in (2). The processor 40 ensures that, for example, the radiation generator 11 changes direction to face the electronic cassette 12 while approaching the target position HP from the standby position HP. This makes it possible to perform the final position adjustment as a straight-line movement. Straight-line movement provides higher accuracy in self-position estimation than rotational movement. Therefore, by performing the final position adjustment as a highly accurate straight-line movement, it becomes possible to accurately align the radiation generator 11 and the electronic cassette 12. Furthermore, it is preferable to complete the final position adjustment using only straight-line movement, so as not to involve any slight rotational movement in the final position adjustment. Thus, in addition to controlling the frame rate according to the driving conditions, such improvements to the operation procedure may be made.

[0095] In addition to determining whether the radiation generator 11 has approached the target position TP, other methods can be considered besides determining whether the difference between the pre-set target position TP and the estimated self-position falls within a pre-set range. For example, the following can be considered: One is the detection of the electronic cassette 12 or patient P based on the travel control image 70. Rather than simply detecting them, the determination may also be made by considering the distance to the electronic cassette 12 or patient P.

[0096] (Modification 4) Furthermore, as shown in Figure 23, the processor 40 may acquire fixed-point images representing the environment around the radiation generator 11, captured by a fixed-point camera 96 ​​installed at a fixed position, and perform driving control based on the driving control image 70 and the fixed-point images. The fixed-point camera 96 ​​is, for example, fixed at a fixed position in the imaging room RM, and can capture the entire area in which the radiation generator 11 moves within its field of view. The fixed-point images are, for example, moving images, and can capture moving objects within the path of the radiation generator 11. When tracking feature points FP based on the driving control image 70, if moving objects other than the radiation generator 11 are captured, they become noise in self-localization estimation. Therefore, the processor 40 can identify moving objects other than the radiation generator 11 from the fixed-point images and exclude the identified moving objects as noise, thereby enabling highly accurate self-localization estimation. Thus, in addition to controlling the frame rate according to the driving state, measures may be taken to remove such noise.

[0097] Furthermore, the above embodiment is merely an example and can be modified as appropriate as follows.

[0098] The bogie section 16 may be eliminated, and the wheels 15 may be directly attached to the lower part of the main body section 14.

[0099] Camera 32 may be attached to the arm 27 instead of the radiation source 13. Similarly, camera 33 may be provided on the main body 14 instead of the trolley 16. There may be multiple cameras 32 and 33.

[0100] Cameras 32 and 33 may be combined into a single camera. In this case, the camera orientation is set so that it can capture images for driving control 70 when in the storage position, and so that it can capture images for alignment control 85 when in the preparation position for shooting.

[0101] The environmental information sensor is not limited to the example camera 33. LiDAR (Light Detection and Ranging) sensors, TOF (Time-of-Flight) sensors, etc., may also be used. In addition, an IMU (Inertial Measurement Unit) combining an accelerometer and a gyroscope, an ultrasonic sensor, a radar sensor, a magnetic sensor, etc., may also be used.

[0102] The information acquisition frequency is not limited to the frame rate of camera 33. For example, in the case of LiDAR, it includes the information acquisition frequency corresponding to the type of environmental information sensor mentioned above, such as the frequency of acquiring depth images.

[0103] Furthermore, the radiation image detection device is not limited to the example electronic cassette 12. A CR (Computed Radiography) cassette may also be used. Also, the radiation image detection device may be one in which the radiation detector is fixed to the imaging table. Furthermore, the subject is not limited to the example patient P. A diseased animal such as a dog or cat may also be used.

[0104] Furthermore, although the radiation generating device 11 was used as an example of a radiography device, the radiography device may also be a radiation image detection device having a travel mechanism.

[0105] The above description discloses the following additional information. [Additional note 1] A radiography apparatus used for radiography, A radiation source or radiation image detection device, An autonomous driving mechanism including an environmental information sensor that acquires information about the surrounding environment, A processor for controlling a driving mechanism, comprising a processor capable of controlling the frequency of information acquisition from an environmental information sensor according to the driving state of the driving mechanism. Radiography equipment. [Additional note 2] The driving state includes at least one of the direction of movement and the speed of movement. The radiography apparatus described in Appendix 1. [Additional note 3] Driving states include straight-line movement where the direction of movement does not change, and rotational movement where the direction of movement changes. Straight-line movement includes forward / backward movement, sideways movement, and diagonal movement. The radiography equipment described in Appendix 2. [Additional note 4] The processor acquires information more frequently in the case of rotational movement than in the case of linear movement. The radiography apparatus described in Appendix 3. [Additional note 5] The processor retrieves information more frequently when moving horizontally or diagonally than when moving forward or backward. The radiography equipment described in Appendix 4. [Additional note 6] The processor is When rotational movement and linear movement occur simultaneously, the frequency of information acquisition should be higher than when only linear movement is performed. A radiography apparatus as described in any one of the appendices 3 to 5. [Additional note 7] The processor controls the travel mechanism so that the final position adjustment to the target location results in straight-line movement. A radiography apparatus as described in any one of the appendices 3 to 6. [Additional note 8] The processor increases the frequency of information retrieval as the movement speed increases. The radiography equipment described in Appendix 2. [Additional note 9] The processor acquires fixed-point images representing the surrounding environment, captured by a fixed-point camera positioned in a fixed location. Based on environmental information acquired from environmental information sensors and fixed-point captured images, driving control is performed. A radiography apparatus as described in any one of the appendices 1 to 8. [Additional Note 10] An environmental information sensor is a camera that captures images of the surrounding environment. The frequency of information acquisition is the frame rate. A radiography apparatus as described in any one of the appendices 1 to 9. [Additional Note 11] It is a radiation generating device that has a radiation source. A radiography apparatus as described in any one of the appendices 1 to 10. [Additional Note 12] A method for operating a radiography apparatus used for radiography, comprising a radiation source or radiation image detection device, an autonomous driving mechanism including an environmental information sensor for acquiring information about the surrounding environment, and a processor for controlling the driving mechanism, The processor includes controlling the frequency of information acquisition from environmental information sensors according to the driving state of the driving mechanism. How to operate a radiography device. [Additional Note 13] An operating program for a radiography apparatus used for radiography, comprising a radiation source or radiation image detection device, an autonomous driving mechanism including an environmental information sensor for acquiring information about the surrounding environment, and a processor for controlling the driving mechanism, The processor is instructed to execute a process that controls the frequency of information acquisition from the environmental information sensor according to the driving state of the driving mechanism. The operating program for the radiography device.

[0106] In the above embodiment, the processing performed by the processor 40 is performed on any computer. Furthermore, any computer may perform these processes using a processor as hardware, a program as software, or a combination thereof. In that case, the processor is configured to cooperate with the program to perform the various processes in this embodiment, and can function as a unit or means in this embodiment. Also, the execution order of the processes by the processor is not limited to the order described and may be changed as appropriate.

[0107] Any computer may be a general-purpose computer, a computer designed for a specific purpose, a workstation, or any other system capable of performing each process. The processor may consist of one or more hardware components, and the type of hardware is not limited. For example, the processor may consist of hardware such as a CPU (Central Processing Unit), MPU (Micro Processing Unit), FPGA (Field Programmable Gate Array) or other programmable logic devices, ASIC (Application Specific Integrated Circuit) or other dedicated circuits for performing specific processes, GPU (Graphic Processing Unit), or NPU (Neural Processing Unit). Furthermore, the type of hardware may be a combination of different types of hardware. When multiple hardware components are configured to perform one or more processes of a given processor, these multiple hardware components may reside in physically separate devices or in the same device. Also, in any embodiment, the order of each process performed by the processor is not limited to the order described above and may be changed as appropriate. Hardware is composed of electrical circuits (circuitry) that combine circuit elements such as semiconductor elements.

[0108] Furthermore, the program may be firmware or software such as microcode. Alternatively, the program may be, for example, a set of program modules, each function of which may be implemented by a processor configured to perform its respective function. The program may be program code or multiple code segments stored on one or more non-temporary computer-readable media (e.g., storage media or other storage devices). The program may be divided and stored on multiple non-temporary computer-readable media located in physically separate devices. Program code or code segments may represent any combination of procedures, functions, subprograms, routines, subroutines, modules, software packages, classes, or instructions, data structures, or program statements. Program code or code segments may be connected to other code segments or hardware circuits by sending and receiving information, data, arguments, parameters, or memory contents.

[0109] The technology of this disclosure can be appropriately combined with the various embodiments and / or variations described above. Furthermore, it is understood that various configurations can be adopted without departing from the gist of the invention, and the invention is not limited to the embodiments described above. In addition, the technology of this disclosure extends to storage media for storing programs non-temporarily. The storage media are computer-readable non-temporarily storage media such as USB (Universal Serial Bus) memory, flexible disks, and CD-ROMs (Compact Disc Read Only Memory). Programs may also be provided online via a network such as the Internet. Furthermore, the technology of this disclosure extends to program products in addition to programs. Program products include all forms of products for providing programs. Like programs, program products may be stored and provided on computer-readable non-temporarily storage media, or they may be provided online.

[0110] The descriptions and illustrations presented above are detailed explanations of the technical aspects of this disclosure and are merely examples of the technical aspects. For example, the above descriptions of the structure, function, operation, and effect are examples of the structure, function, operation, and effect of the technical aspects of this disclosure. Therefore, it goes without saying that you may delete unnecessary parts, add new elements, or replace elements in the descriptions and illustrations presented above, as long as you do not deviate from the essence of the technical aspects of this disclosure. Furthermore, in order to avoid confusion and facilitate understanding of the technical aspects of this disclosure, explanations of common technical knowledge and the like that do not require special explanation to enable the implementation of the technical aspects of this disclosure have been omitted from the descriptions and illustrations presented above.

[0111] In this specification, "A and / or B" is synonymous with "at least one of A and B." That is, "A and / or B" means that it may be A alone, or B alone, or a combination of A and B. Furthermore, in this specification, the same concept as "A and / or B" applies when expressing three or more things linked by "and / or."

[0112] All documents, patent applications, and technical standards described herein are incorporated by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually noted to be incorporated by reference. [Explanation of symbols]

[0113] 10. Radiography System 11. Radiation Generating Devices 12 Electronic Cassettes 13 Radiation source 14 Main body 15 wheels 16 Bogie section 17 Detection surface 18. Radiological images 19 Recumbent photography stand 20 Standing position imaging table 21 Holder 22 Posts 25 Moving parts 26 Fixed part 27 Arms 28 Control Panel 30 Radiation tubes 31 Irradiation field limiter 32, 33 Camera 40 processors 41 Storage 42 Operating Program 43 Control data 50 Communication I / F 51. Drive actuator 51A Driving status detection sensor 52 Alignment Actuator 53. Source position detection sensor 60 Image acquisition unit 61 Feature Point Extraction Unit 62 Self-Position Estimation and Map Data Creation Section 63 Driving control unit 70 Images for driving control 71 Feature point extraction results 71P Feature point extraction results (past data) 72 Estimation results 73 Map data 73P Map data (past data) 80 Cassette contour extraction section 81 Source position / attitude derivation part 82 Alignment Control Unit 85 Image for alignment control 85L Image for learning and alignment control 86 Cassette Recognition Model 87 Cassette contour extraction results 87CA Correct Answer Data 87L Training Cassette Contour Extraction Results 88 Derivation results 90 training data 91 Alignment support screen 92 Tables 96 Fixed-point cameras BT Battery The center of the detection surface of the CC electronic cassette. Frame F FP characteristic points FR1, FR2, FR3 frame rates HP standby position Outline of an OLC electronic cassette OP Operator PS Self-position R radiation RC radiation irradiation center RM Photo Studio T1, T2, T3 Image acquisition interval TP target position TP1 1st target position TP2 2nd target position

Claims

1. A radiography apparatus used for radiography, A radiation source or radiation image detection device, An autonomous driving mechanism including an environmental information sensor that acquires information about the surrounding environment, A processor for controlling the travel mechanism, comprising a processor capable of controlling the frequency of information acquisition from the environmental information sensor according to the travel state of the travel mechanism. Radiography equipment.

2. The aforementioned travel state includes at least one of the direction of travel and the speed of travel. The radiography apparatus according to claim 1.

3. The aforementioned driving state includes straight-line movement in which the direction of movement does not change, and rotational movement in which the direction of movement changes. The aforementioned straight-line movement includes forward and backward movement, lateral movement, and diagonal movement. The radiography apparatus according to claim 2.

4. The processor increases the frequency of information acquisition in the case of rotational movement compared to the case of linear movement. The radiography apparatus according to claim 3.

5. The processor increases the frequency of information acquisition in the case of lateral movement or diagonal movement compared to the case of forward and backward movement. The radiography apparatus according to claim 4.

6. The aforementioned processor, When the rotational movement and the linear movement are performed in parallel, the frequency of information acquisition is increased compared to when only the linear movement is performed. The radiography apparatus according to claim 3.

7. The processor controls the travel mechanism so that the final position adjustment to the target position becomes the straight-line movement. The radiography apparatus according to claim 3.

8. The processor increases the frequency of information acquisition as the movement speed increases. The radiography apparatus according to claim 2.

9. The processor acquires a fixed-point image representing the surrounding environment, which is captured by a fixed-point camera installed at a fixed location. Based on the environmental information acquired from the environmental information sensor and the fixed-point captured images, driving control is performed. The radiography apparatus according to claim 1.

10. The aforementioned environmental information sensor is a camera that captures images of the surrounding environment. The information acquisition frequency is the frame rate. The radiography apparatus according to claim 1.

11. This is a radiation generating device having the aforementioned radiation source. The radiography apparatus according to claim 1.

12. A method for operating a radiography apparatus used for radiography, comprising a radiation source or radiation image detection device, an autonomous driving mechanism including an environmental information sensor for acquiring information about the surrounding environment, and a processor for controlling the driving mechanism, The processor includes controlling the frequency of information acquisition from the environmental information sensor according to the driving state of the driving mechanism. How to operate a radiography device.

13. An operating program for a radiography apparatus used for radiography, comprising a radiation source or radiation image detection device, an autonomous driving mechanism including an environmental information sensor for acquiring information about the surrounding environment, and a processor for controlling the driving mechanism, The processor is instructed to execute a process that controls the frequency of information acquisition from the environmental information sensor according to the driving state of the aforementioned driving mechanism. The operating program for the radiography device.

Images