A linear accelerator rotating frame operating state monitoring system and method

Abstract

The invention relates to the field of medical technology, and in particular to a linear accelerator rotating frame operation status monitoring system and method. The linear accelerator rotating frame operation status monitoring system comprises an angle acquisition module, a current acquisition module and a central processing module; the angle acquisition module acquires rotation angle data of the linear accelerator rotating frame, and transmits the rotation angle data of the rotating frame to the central processing module; the current acquisition module acquires the current of the motor of the linear accelerator, extracts the amplitude of the direct current of the motor current waveform, and transmits the amplitude of the direct current of the current waveform to the central processing module; the central processing module calculates the friction coefficient of the bearing on the linear accelerator rotating frame and the deformation of the linear accelerator rotating frame according to the rotation angle data of the rotating frame and the amplitude of the direct current of the current waveform, so as to provide information for overhauling and maintaining the linear accelerator.

Description

Technical Field

[0001] The present invention relates to the field of medical technology, and in particular to a system and method for monitoring the operating status of a rotating frame of a linear accelerator. Background Art

[0002] A linear accelerator is an accelerator that uses microwave electromagnetic fields to accelerate electrons and has a linear motion track. It is a medical device used for radiotherapy of tumors or other lesions in patients. It can generate high-energy X-rays and electron beams, and has the characteristics of high dose rate, short irradiation time, large irradiation field, good dose uniformity and stability, and small penumbra.

[0003] At present, the linear accelerator integrates the accelerator's beam system and CT detector on the rotating frame. Together with the counterweight, the load of the entire frame is close to one ton, which is a challenge to the load-bearing capacity of the rotating bearing and the frame. For a newly developed rotating frame system, verification testing is required. For a CT-LA linear accelerator that has been put into operation, the status of the rotating frame also needs to be obtained.

[0004] The existing linear accelerator operation monitoring system cannot monitor the friction coefficient of the bearings on the linear accelerator rotating frame and the deformation of the linear accelerator rotating frame, resulting in the inability to provide information for inspection and maintenance. Summary of the invention

[0005] The object of the present invention is to provide a linear accelerator rotating frame operating status monitoring system and method, which can monitor the friction coefficient of the bearing on the linear accelerator rotating frame and the deformation of the linear accelerator rotating frame, and provide information for repairing and maintaining the linear accelerator.

[0006] To achieve the above-mentioned object, in a first aspect, the present invention provides a linear accelerator rotating frame operation status monitoring system, comprising an angle acquisition module, a current acquisition module and a central processing module;

[0007] The angle acquisition module is connected to the central processing module, and the current acquisition module is connected to the central processing module.

[0008] Wherein, the linear accelerator rotating frame operation status monitoring system also includes an output module; the output module is connected to the central processing module.

[0009] The angle acquisition module is used to acquire the rotation angle data of the rotating frame of the linear accelerator, and transmit the rotation angle data of the rotating frame to the central processing module.

[0010] The current acquisition module is used to acquire the current of the motor of the linear accelerator, extract the amplitude of the DC current waveform of the motor, and transmit the amplitude of the DC current waveform to the central processing module.

[0011] The central processing module is used to calculate the friction coefficient of the bearing on the rotating frame of the linear accelerator and the deformation of the rotating frame of the linear accelerator according to the rotation angle data of the rotating frame and the amplitude of the DC current waveform.

[0012] The output module is used to output the friction coefficient of the bearing on the rotating frame of the linear accelerator and the deformation data of the rotating frame of the linear accelerator calculated by the central processing module.

[0013] In a second aspect, the present invention further provides a method for monitoring the operating status of a linear accelerator rotating frame.

[0014] include:

[0015] Collect the rotation angle data of the linear accelerator rotating frame;

[0016] Collect the current of the motor of the linear accelerator and extract the DC amplitude of the current waveform of the motor;

[0017] According to the rotation angle data of the rotating frame and the amplitude of the DC current waveform, the friction coefficient of the bearing on the rotating frame of the linear accelerator and the deformation of the rotating frame of the linear accelerator are calculated.

[0018] The specific steps of calculating the friction coefficient of the bearing on the rotating frame of the linear accelerator and the deformation of the rotating frame of the linear accelerator according to the rotation angle data of the rotating frame and the amplitude of the DC current waveform include:

[0019] According to the rotation angle data of the rotating frame and the amplitude of the DC current waveform, the friction coefficient of the bearing on the rotating frame of the linear accelerator is calculated;

[0020] The deformation of the rotating frame of the linear accelerator is calculated based on the rotation angle data of the rotating frame and the amplitude of the DC current waveform.

[0021] The specific steps of calculating the friction coefficient of the bearing on the rotating frame of the linear accelerator according to the rotating frame rotation angle data and the amplitude of the DC current waveform include:

[0022] According to the formula B = K * I DC / w calculates the friction coefficient of the bearing on the rotating frame of the linear accelerator, where B represents the friction coefficient of the bearing, I DC It represents the amplitude of the DC current waveform, and w represents the angular velocity of the rotating frame.

[0023] Among them, according to the formula B = K*I DC / w is used to calculate the friction coefficient of the bearing on the rotating frame of the linear accelerator, where K is a constant set according to the transmission mechanism actually used in the motor.

[0024] The present invention discloses a linear accelerator rotating frame operation status monitoring system and method. The angle acquisition module acquires the rotation angle data of the linear accelerator rotating frame, and transmits the rotation angle data of the rotating frame to the central processing module. The current acquisition module acquires the current of the motor of the linear accelerator, extracts the amplitude of the direct current of the motor current waveform, and transmits the amplitude of the direct current of the current waveform to the central processing module. The central processing module calculates the friction coefficient of the bearing on the linear accelerator rotating frame and the deformation of the linear accelerator rotating frame according to the rotation angle data of the rotating frame and the amplitude of the direct current of the current waveform. The present invention can monitor the friction coefficient of the bearing on the linear accelerator rotating frame and the deformation of the linear accelerator rotating frame, and provide information for overhauling and maintaining the linear accelerator. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0026] Figure 1 It is a schematic diagram of the rotating frame when the linear accelerator does not drive the motor.

[0027] Figure 2 It is a schematic diagram of the rotating frame of the linear accelerator in a low-speed rotation state.

[0028] Figure 3 It is the waveform of the motor current when the linear accelerator is in CT scanning mode and the rotating frame moves at a constant speed.

[0029] Figure 4 It is a structural schematic diagram of a linear accelerator rotating frame operating status monitoring system of the present invention.

[0030] Figure 5 The present invention is a schematic diagram of a linear accelerator rotating frame operating status monitoring system.

[0031] Figure 6 The present invention is a flow chart of a method for monitoring the operating status of a linear accelerator rotating frame.

[0032] Figure 7 The present invention is a flow chart for calculating the friction coefficient of the bearing on the rotating frame of the linear accelerator and the deformation amount of the rotating frame of the linear accelerator according to the rotating frame rotation angle data and the amplitude of the DC current waveform.

[0033] 101 - angle acquisition module, 102 - current acquisition module, 103 - central processing module, 104 - output module. DETAILED DESCRIPTION

[0034] In a first aspect, the present invention provides a linear accelerator rotating frame operation status monitoring system, see Figure 1-Figure 5 ,in, Figure 1 It is a schematic diagram of the rotating frame when the linear accelerator does not drive the motor. Figure 2 It is a schematic diagram of the rotating frame of the linear accelerator in a low-speed rotation state. Figure 3 It is the waveform of the motor current when the linear accelerator is in CT scanning mode and the rotating frame moves at a constant speed. Figure 4 It is a structural schematic diagram of a linear accelerator rotating frame operating status monitoring system of the present invention. Figure 5 The present invention is a schematic diagram of a linear accelerator rotating frame operating status monitoring system.

[0035] The present invention provides a linear accelerator rotating frame operation status monitoring system, comprising an angle acquisition module 101, a current acquisition module 102, a central processing module 103 and an output module 104; through the above scheme, the friction coefficient and deformation of the bearing on the linear accelerator rotating frame can be monitored to provide information for the inspection and maintenance of the linear accelerator.

[0036] For this specific implementation, the angle acquisition module 101 is connected to the central processing module 103, and the current acquisition module 102 is connected to the central processing module 103. The angle acquisition module 101 is used to collect the rotation angle data of the rotating frame of the linear accelerator, and transmit the rotation angle data of the rotating frame to the central processing module 103. The current acquisition module 102 is used to collect the current of the motor of the linear accelerator, extract the amplitude of the direct current of the current waveform of the motor, and transmit the amplitude of the direct current of the current waveform to the central processing module 103. The central processing module 103 is used to calculate the friction coefficient of the bearing on the rotating frame of the linear accelerator and the deformation of the rotating frame of the linear accelerator according to the rotation angle data of the rotating frame and the amplitude of the direct current of the current waveform. The angle acquisition module 101 can use a grating ruler, the current acquisition module 102 can use a motor current adopting circuit, and the central processing module 103 can use a logic controller.

[0037] The output module 104 is connected to the central processing module 103. The output module 104 is used to output the friction coefficient of the bearing on the linear accelerator rotating frame and the deformation data of the linear accelerator rotating frame calculated by the central processing module 103.

[0038] When using the present invention, the measuring principle of the present invention is first explained. This application involves the following three torques.

[0039] 1. Torque generated by gravity: reference Figure 1 , Figure 1 Point O is the geometric center of the rotating frame, point P represents the center of gravity of the rotating frame, and OH represents the vertical line through the geometric center, that is, the position with an angle of 0; when the motor is not driven, the position of the rotating frame will be as shown in the figure above, OP will be collinear with the vertical line OH, and the angle is zero. Figure 2 , under low-speed rotation, OP will form an angle with OH, the angle of angle POH is recorded as θ, then the torque T caused by the center of gravity shift P =M*g*|OP|*sin(θ), where M is the mass of the rotating frame and g is the acceleration due to gravity.

[0040] 2. Torque generated by friction: T f =B*w, where w is the angular velocity of rotation.

[0041] 3. Torque generated by deformation: T c (θ), is a function of angular displacement

[0042] The relationship between the torque and current provided by the motor is: T M =K*I K is a constant related to the transmission mechanism. I is the motor phase current.

[0043] When the linear accelerator is in CT scanning mode, the gantry moves at a constant speed (w is a constant about θ). M =T P +T f +T c ,

[0044] So the motor current: I = [M*g*|OP| / K]*sin(θ)+B*w+T c (θ), reference Figure 3 The realized waveform in Figure 3 The horizontal dotted line in the middle represents the DC component of the current, the dotted sinusoidal line represents the theoretical current waveform without deformation, and the solid line is the actual current waveform.

[0045] Among them: [M*g*|OP| / K]*sin(θ) corresponds to the dotted sine wave in the figure, which is the parameter of the rotating frame and can be obtained through theoretical calculation. The waveform of B*w corresponds to the horizontal dotted line in the figure, which is the DC component of the motor current. The difference between the solid current I(θ) waveform and the dotted sine wave corresponds to the torque mutation T caused by deformation. c (θ).

[0046] Based on the above principle, the motor current is measured and the amplitude I of the DC current waveform is extracted. DC , through the formula: B*w=K*I DC The friction coefficient can be obtained: B = K*I DC / w, the friction coefficient can reflect the working state of the bearing. c (θ)=I(θ)-[M*g*|OP| / K]*sin(θ)-I DC , where T c (θ) represents the deformation of the rotating frame at θ, which is expressed by the magnitude of the torque. I(θ) is the relationship between the motor current and the angle. M is the mass of the rotating frame. OP is the length from the geometric center of the rotating frame to the center of gravity of the rotating frame. I DC The magnitude of the DC component of the current is measured. By measuring the difference between the motor current and the dotted sine wave, the deformation of the bearing bracket at various angles can be estimated. In this way, the friction coefficient of the bearing on the linear accelerator rotating frame and the deformation of the linear accelerator rotating frame can be monitored to provide information for the inspection and maintenance of the linear accelerator.

[0047] Second, see Figure 6-Figure 7 ,in, Figure 6 The present invention is a flow chart of a method for monitoring the operating status of a linear accelerator rotating frame. Figure 7 The present invention is a flow chart for calculating the friction coefficient of the bearing on the rotating frame of the linear accelerator and the deformation amount of the rotating frame of the linear accelerator according to the rotating frame rotation angle data and the amplitude of the DC current waveform.

[0048] The present invention also provides a method for monitoring the operating status of a linear accelerator rotating frame, comprising:

[0049] S1 collects the rotation angle data of the linear accelerator rotating frame;

[0050] S2 collects the current of the motor of the linear accelerator and extracts the DC amplitude of the current waveform of the motor;

[0051] S3 calculates the friction coefficient of the bearing on the rotating frame of the linear accelerator and the deformation of the rotating frame of the linear accelerator according to the rotation angle data of the rotating frame and the amplitude of the DC current waveform.

[0052] The specific steps include:

[0053] S31 calculates the friction coefficient of the bearing on the rotating frame of the linear accelerator according to the rotating frame rotation angle data and the amplitude of the DC current waveform;

[0054] The specific steps include:

[0055] According to the formula B = K * I DC / w is used to calculate the friction coefficient of the bearing on the rotating frame of the linear accelerator, where B represents the friction coefficient of the bearing, K is a constant set according to the actual transmission mechanism used by the motor, and I DC It represents the amplitude of the DC current waveform, and w represents the angular velocity of the rotating frame.

[0056] S32 calculates the deformation amount of the rotating frame of the linear accelerator according to the rotating frame rotation angle data and the amplitude of the DC current waveform.

[0057] The specific steps include:

[0058] According to the formula T c (θ)=I(θ)-[M*g*|OP| / K]*sin(θ)-I DC The deformation of the rotating frame of the linear accelerator is calculated.

[0059] A method for monitoring the operating status of a linear accelerator rotating frame of the present invention, when using the present invention, firstly the measurement principle of the method of the present invention is explained, and the present application involves the following three torques.

[0060] 1. Torque generated by gravity: reference Figure 1 , Figure 1 Point O is the geometric center of the rotating frame, point P represents the center of gravity of the rotating frame, and OH represents the vertical line through the geometric center, that is, the position with an angle of 0; when the motor is not driven, the position of the rotating frame will be as shown in the figure above, OP will be collinear with the vertical line OH, and the angle is zero. Figure 2 , under low-speed rotation, OP will form an angle with OH, the angle of angle POH is recorded as θ, then the torque T caused by the center of gravity shift P =M*g*|OP|*sin(θ), where M is the mass of the rotating frame and g is the acceleration due to gravity.

[0061] 2. Torque generated by friction: T f =B*w, where w is the angular velocity of rotation.

[0062] 3. Torque generated by deformation: T c (θ), is a function of angular displacement

[0063] The relationship between the torque and current provided by the motor is: T M =K*I K is a constant related to the transmission mechanism. I is the motor phase current.

[0064] When the linear accelerator is in CT scanning mode, the gantry moves at a constant speed (w is a constant about θ). M =T P +T f +T c ,

[0065] So the motor current: I = [M*g*|OP| / K]*sin(θ)+B*w+T c (θ), reference Figure 3 The realized waveform in Figure 3 The horizontal dotted line in the middle represents the DC component of the current, the dotted sinusoidal line represents the theoretical current waveform without deformation, and the solid line is the actual current waveform.

[0066] Among them: [M*g*|OP| / K]*sin(θ) corresponds to the dotted sine wave in the figure, which is the parameter of the rotating frame and can be obtained through theoretical calculation. The waveform of B*w corresponds to the horizontal dotted line in the figure, which is the DC component of the motor current. The difference between the solid current I(θ) waveform and the dotted sine wave corresponds to the torque mutation T caused by deformation. c (θ).

[0067] Based on the above principle, the motor current is measured and the amplitude I of the DC current waveform is extracted. DC , through the formula: B*w=K*I DC The friction coefficient can be obtained: B = K*I DC / w, the friction coefficient can reflect the working state of the bearing. c (θ)=I(θ)-[M*g*|OP| / K]*sin(θ)-I DC , where T c (θ) represents the deformation of the rotating frame at θ, which is expressed by the magnitude of the torque. I(θ) is the relationship between the motor current and the angle. M is the mass of the rotating frame. OP is the length from the geometric center of the rotating frame to the center of gravity of the rotating frame. I DC The magnitude of the DC component of the current is measured. By measuring the difference between the motor current and the dotted sine wave, the deformation of the bearing bracket at each angle can be estimated. The linear accelerator rotating frame operation status monitoring method of the present invention can monitor the friction coefficient of the bearing on the linear accelerator rotating frame and the deformation of the linear accelerator rotating frame, and provide information for the inspection and maintenance of the linear accelerator.

[0068] What is disclosed above is only one or more preferred embodiments of the present application, and cannot be used to limit the scope of rights of the present application. Ordinary technicians in this field can understand that all or part of the processes of implementing the above embodiments and equivalent changes made according to the claims of the present application are still within the scope covered by the present application.

Claims

1. A linear accelerator rotating frame operation status monitoring system, characterized in that: It includes an angle acquisition module, a current acquisition module and a central processing module; The angle acquisition module is connected to the central processing module, and the current acquisition module is connected to the central processing module; The central processing module is used to calculate the friction coefficient of the bearing on the rotating frame of the linear accelerator and the deformation of the rotating frame of the linear accelerator according to the rotation angle data of the rotating frame and the amplitude of the DC current waveform; According to the formula B = K * I DC / w calculates the friction coefficient of the bearing on the rotating frame of the linear accelerator, where B represents the friction coefficient of the bearing, I DC represents the amplitude of the DC current waveform, w represents the angular velocity of the rotating frame; K is a constant set according to the transmission mechanism actually used by the motor; Through the formula Tc(θ)=I(θ)-[M*g*|OP| / K]*sin(θ)-I DC The deformation of the rotating frame of the linear accelerator is calculated, where Tc(θ) represents the deformation of the rotating frame at θ, expressed by the magnitude of the torque, I(θ) is the relationship between the motor current and the angle, M is the mass of the rotating frame, g is the gravitational acceleration, OP is the length from the geometric center of the rotating frame to the center of gravity of the rotating frame, and K is a constant set according to the actual transmission mechanism used by the motor; I DC It is the amplitude of the DC component of the current.

2. A linear accelerator rotating frame operation status monitoring system as claimed in claim 1, characterized in that: The linear accelerator rotating frame operation status monitoring system also includes an output module; the output module is connected to the central processing module.

3. A linear accelerator rotating frame operation status monitoring system as claimed in claim 2, characterized in that: The angle acquisition module is used to acquire the rotation angle data of the rotating frame of the linear accelerator, and transmit the rotation angle data of the rotating frame to the central processing module.

4. A linear accelerator rotating frame operation status monitoring system as claimed in claim 3, characterized in that: The current acquisition module is used to acquire the current of the motor of the linear accelerator, extract the amplitude of the DC current waveform of the motor, and transmit the amplitude of the DC current waveform to the central processing module.

5. A linear accelerator rotating frame operation status monitoring system as claimed in claim 2, characterized in that: The output module is used to output the friction coefficient of the bearing on the linear accelerator rotating frame and the deformation data of the linear accelerator rotating frame calculated by the central processing module.

6. A method for monitoring the operating status of a linear accelerator rotating frame, applied to a linear accelerator rotating frame operating status monitoring system as claimed in any one of claims 1 to 5, characterized in that: include: Collect the rotation angle data of the linear accelerator rotating frame; Collect the current of the motor of the linear accelerator and extract the DC amplitude of the current waveform of the motor; According to the rotation angle data of the rotating frame and the amplitude of the DC current waveform, the friction coefficient of the bearing on the rotating frame of the linear accelerator and the deformation of the rotating frame of the linear accelerator are calculated; According to the rotation angle data of the rotating frame and the amplitude of the DC current waveform, the friction coefficient of the bearing on the rotating frame of the linear accelerator is calculated; According to the formula B = K * I DC / w calculates the friction coefficient of the bearing on the rotating frame of the linear accelerator, where B represents the friction coefficient of the bearing, I DC represents the amplitude of the DC current waveform, w represents the angular velocity of the rotating frame; K is a constant set according to the transmission mechanism actually used by the motor; The deformation of the rotating frame of the linear accelerator is calculated according to the rotation angle data of the rotating frame and the amplitude of the DC current waveform; Through the formula Tc(θ)=I(θ)-[M*g*|OP| / K]*sin(θ)-I DC The deformation of the rotating frame of the linear accelerator is calculated, where Tc(θ) represents the deformation of the rotating frame at θ, expressed by the magnitude of the torque, I(θ) is the relationship between the motor current and the angle, M is the mass of the rotating frame, g is the gravitational acceleration, OP is the length from the geometric center of the rotating frame to the center of gravity of the rotating frame, and K is a constant set according to the actual transmission mechanism used by the motor; I DC It is the amplitude of the DC component of the current.

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