Neutron diffraction stress measuring device and method based on space coordinate measurement

Abstract

The invention provides a neutron diffraction stress measurement device and method based on space coordinate measurement. The neutron diffraction stress measurement device comprises an autonomous navigation trolley, an attitude adjustment system, a space measurement sensor, a neutron detector, a sample table and a main controller, the attitude adjusting system is fixedly mounted on the autonomous navigation trolley, the neutron detector is detachably mounted on the attitude adjusting system, and the autonomous navigation trolley is used for carrying the neutron detector and the attitude adjusting system to move to a position near a specified position in a measurement space; the space measurement sensor is used for measuring the actual position posture of the neutron detector in a measurement space and sending measurement data to the main controller; the main controller is used for sending a motion instruction, receiving measurement data, executing coordinate transformation operation and kinematics inverse solution operation and outputting a control signal. Through combination of the autonomous navigation trolley, the attitude adjustment system and the space measurement system, accurate positioning of the neutron detector in a neutron measurement space is realized, and a neutron diffraction stress measurement task is completed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of neutron diffraction stress measurement, in particular to a neutron diffraction stress measurement device and method based on spatial coordinate measurement. BACKGROUND

[0002] The neutron diffraction stress measurement technology is a key means for non-destructive detection of internal stress of materials, and is widely used in fields of mechanical manufacturing, aerospace, nuclear power equipment, etc. The residual stress or working stress of materials can be inverted by analyzing the diffraction characteristics of neutron beams, which is crucial for evaluating the safety of components and the rationality of processes.

[0003] The existing neutron diffraction stress measurement device adopts a "fixed turntable + connecting rod mechanism" architecture, fixes the neutron detector on the turntable, and adjusts the position through the connecting rod transmission. There are obvious technical defects: first, the error accumulation is serious. The manufacturing deviation of the turntable, the machining error of the connecting rod, and the assembly gap of multiple links are superimposed, resulting in insufficient positioning accuracy of the detector, which is difficult to meet the high-precision measurement requirements. Second, the moving flexibility is poor. The rigidity constraint of the connecting rod limits the motion trajectory of the detector, which cannot adapt to large-size sample measurement, and the rotation angle around the sample is limited, which is easy to form a measurement dead angle. Third, the attitude adjustment capability is weak. Only 2-3 degrees of freedom can be coarsely adjusted, which cannot finely compensate for the sample clamping deviation or match the specific diffraction angle, affecting the signal reception efficiency.

[0004] The above defects restrict the measurement accuracy and the expansion of application scenarios, making it difficult to meet the complex sample and high-precision detection requirements. It is urgent to improve the device architecture to break through the technical bottleneck. SUMMARY

[0005] In view of the defects in the prior art, the purpose of the present application is to provide a neutron diffraction stress measurement device and method based on spatial coordinate measurement.

[0006] According to the neutron diffraction stress measurement device based on spatial coordinate measurement provided by the present application, the self-navigation trolley, the attitude adjustment system, the spatial measurement sensor, the neutron detector, the sample table and the main controller are included. The attitude adjustment system is fixedly installed on the self-navigation trolley, and the neutron detector is detachably installed on the attitude adjustment system. The self-navigation trolley is used to carry the neutron detector and the attitude adjustment system to move to the vicinity of the specified position in the measurement space. The spatial measurement sensor is used to measure the actual position and attitude of the neutron detector in the measurement space, and sends the measurement data to the main controller. The main controller is electrically connected with the self-navigation trolley, the attitude adjustment system and the spatial measurement sensor, respectively, for sending motion instructions, receiving measurement data, performing coordinate transformation operation and kinematics inverse solution operation, and outputting control signals. The sample stage is arranged in the measurement range of the neutron detector, and is used for carrying a sample to be measured and adjusting the position and posture of the sample.

[0007] Preferably, the posture adjustment system is a precise six-degree-of-freedom parallel mechanism, which is used for adjusting the six-degree-of-freedom position and posture of the neutron detector to compensate for the motion error of the autonomous navigation trolley.

[0008] Preferably, the spatial measurement sensor is a laser tracker or a machine vision sensor, which is used for outputting the three-dimensional position and posture data of the neutron detector in the measurement space.

[0009] Preferably, the probe motion mechanism is further included, which is connected with the spatial measurement sensor and is used for driving the spatial measurement sensor to adjust the spatial position.

[0010] Preferably, the detector controller is further included, which is electrically connected with the neutron detector and is used for controlling the working state of the neutron detector and recording the measurement data. The detector controller receives the instruction of the main controller, controls the neutron detector to open / close the diffraction neutron beam measurement function, and records the measured neutron diffraction data in real time and feeds back to the main controller.

[0011] According to the present application, a neutron diffraction stress measurement method based on spatial coordinate measurement is provided, which comprises the following steps: Step S1: The main controller obtains the target measurement position of the neutron detector, sends a motion instruction to the autonomous navigation trolley, and the autonomous navigation trolley carries the neutron detector and the posture adjustment system to move to the vicinity of the target measurement position according to the instruction. Step S2: The main controller synchronously sends an adjustment instruction to the probe motion mechanism, and the probe motion mechanism drives the spatial measurement sensor to move to the measurement station corresponding to the target measurement position. Step S3: The spatial measurement sensor measures the position and posture of the neutron detector, and sends the measured original data to the main controller. Step S4: The main controller performs coordinate transformation operation on the original data, and converts it into the actual position and posture data of the neutron detector in the spectrometer working coordinate system. Step S5: The main controller calculates the deviation vector between the target measurement position and the actual position and posture, and performs kinematic inverse solution operation according to the deviation vector to obtain the joint space compensation amount for compensating the position and posture error. Step S6: the main controller sends a control signal to the posture adjustment system according to the joint space compensation amount, the posture adjustment system drives the neutron detector to move, and position and posture error compensation is completed; Step S7: if the actual position and posture of the neutron detector meets the measurement requirements, the main controller sends a measurement instruction to the detector controller, the detector controller controls the neutron detector to start the measurement function, completes the neutron diffraction stress measurement of the current station, and records the measurement data.

[0012] Preferably, the kinematic inverse solution operation in step S5 is a motion control algorithm for the posture adjustment system, which is used to calculate the displacement amount required by each axis of the precise six-degree-of-freedom parallel mechanism in the joint space according to the deviation vector, so as to realize precise compensation of the six degrees of freedom of the neutron detector.

[0013] Preferably, the measurement accuracy of the space measurement sensor in step S3 is not less than 0.1mm, and the three-dimensional coordinate and attitude angle data of the neutron detector are output in real time.

[0014] Preferably, the method for adjusting the position of the space measurement sensor by the probe movement mechanism in step S2 comprises: The adjustment target is to ensure that there is no obstacle interference with the measurement signal between the space measurement sensor and the neutron detector.

[0015] Compared with the prior art, the present application has the following beneficial effects: 1. The present application directly measures the position and posture of the neutron detector in space through the space measurement sensor, solves the indirect measurement of the traditional neutron diffraction stress spectrometer turntable and the spectrometer structure of the connecting rod, avoids the accumulation of manufacturing errors, assembly errors and motion errors, and improves the system accuracy. 2. The present application transports the neutron detector by the autonomous navigation trolley, the neutron detector can run arbitrarily in the measurement space, is not restricted by the detector table and the connecting rod, can automatically adjust the distance between the detector and the sample table, the rotation angle of the detector around the sample table is larger, and is not restricted by the mechanical structure of the connecting rod.

[0016] 3. The present application can accurately adjust the position and posture of the neutron detector in six degrees of freedom in space through the posture adjustment system, the traditional neutron diffraction stress spectrometer is fixed and cannot be adjusted in multiple degrees of freedom, and completely depends on the installation accuracy and the motion accuracy of the turntable. BRIEF DESCRIPTION OF DRAWINGS

[0017] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments, with reference to the accompanying drawings: Figure 1A structure schematic diagram of a neutron diffraction stress measurement device based on spatial coordinate measurement in the application; Figure 2 A flow chart of a neutron diffraction stress measurement method based on spatial coordinate measurement in the application.

[0018] Explanation of reference signs: DETAILED DESCRIPTION

[0019] The application will be described in detail below with specific examples. The following examples will help those skilled in the art to further understand the application, but do not limit the application in any form. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the application. These are within the scope of protection of the application.

[0020] The application discloses a neutron diffraction stress measurement device and method based on spatial coordinate measurement. Figure 1 and Figure 2 As shown in the drawings, by combining the autonomous navigation trolley 1, the attitude adjustment system 2 and the spatial measurement system, the neutron detector 3 is accurately positioned in the neutron measurement space, and the neutron diffraction stress measurement task is completed.

[0021] The neutron diffraction stress measurement device based on spatial coordinate measurement comprises an autonomous navigation trolley 1, an attitude adjustment system 2, a spatial measurement sensor 4, a neutron detector 3, a sample table 5 and a main controller.

[0022] The spatial measurement sensor 4 has the function of precise coordinate measurement in a large space range, can be used to measure the actual position and attitude of the neutron detector 3 in the measurement space, is used to judge whether the neutron detector 3 reaches the specified position, and provides adjustment data for the subsequent adjustment mechanism. The spatial detector can be realized by using different spatial measurement sensors 4 such as laser trackers and machine vision.

[0023] After the main controller obtains the data measured by the spatial measurement sensor 4, the actual position and attitude of the neutron detector 3 in the spectrometer working coordinate system are obtained through coordinate transformation. The coordinate transformation is a conversion algorithm of spatial coordinates, which is used to convert the results measured by the attitude adjustment system 2 into the actual position and attitude of the neutron detector 3 in the spectrometer working coordinate system.

[0024] The attitude adjustment system 2 is installed on the autonomous navigation trolley 1, and the neutron detector 3 is installed on the attitude adjustment system 2. The autonomous navigation trolley 1 can carry the neutron detector 3 to any position in the measurement space, and the attitude adjustment system 2 can finely adjust the position and attitude of the neutron detector 3 in a small area to compensate for the motion error of the autonomous navigation trolley 1.

[0025] The posture adjustment system 2 can adopt a precise six-degree-of-freedom parallel mechanism to realize precise positioning in a local range. The inverse kinematics is a motion control algorithm for the six-degree-of-freedom parallel mechanism, which is used to solve the displacement amount of each axis of the parallel mechanism in the joint space according to the target position of the neutron detector 3.

[0026] The probe movement mechanism is used to change the position of the spatial measurement sensor 4, because the measurement site environment is complex, and the position of the spatial measurement sensor 4 usually needs to be changed to avoid the shielding condition.

[0027] The sample table 5 is used to carry the measured sample 6, and the position and posture of the sample 6 are adjusted.

[0028] The neutron detector 3 is used to measure the diffracted neutron beam. The detector controller is used to control the operation of the neutron detector 3 and record the measurement data.

[0029] The main controller controls the entire neutron diffraction stress measurement process.

[0030] The measurement method of the neutron diffraction stress measurement device based on spatial coordinate measurement will be described in detail as follows: The neutron diffraction stress measurement method based on spatial coordinate measurement comprises: Step S1: After the main controller obtains the target measurement position of the neutron detector 3, the motion instruction is sent to the autonomous navigation trolley 1, and the autonomous navigation trolley 1 moves to the vicinity of the specified position according to the instruction.

[0031] Step S2: The main controller sends an instruction to control the probe movement mechanism to move the spatial measurement sensor 4 to a spatial measurement position corresponding to the target measurement position of the neutron detector 3.

[0032] Step S3: The spatial measurement sensor 4 measures the neutron detector 3 and sends the data to the main controller.

[0033] Step S4: After the main controller obtains the data measured by the spatial measurement sensor 4, the actual position and posture of the neutron detector 3 in the spectrometer working coordinate system are obtained through coordinate transformation.

[0034] Step S5: The main controller calculates the deviation vector between the target position and the actual position of the neutron detector 3, and calculates the inverse kinematics of the six-degree-of-freedom parallel mechanism according to the deviation vector to obtain the joint space compensation amount of the six-degree-of-freedom parallel mechanism for compensating the position and posture error of the neutron detector 3.

[0035] Step S6: The main controller controls the movement of the six-degree-of-freedom parallel mechanism according to the above compensation amount to complete the position and posture error compensation of the neutron detector 3.

[0036] Step S7: When the position of the neutron detector 3 meets the measurement requirements, the measurement function can be started by the detector controller, the neutron measurement of the current step is completed, and the measurement data is recorded by the detector controller.

[0037] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0038] The specific embodiments of the present application are described above. It should be understood that the present application is not limited to the specific embodiments described above, and various changes or modifications can be made by those skilled in the art within the scope of the claims, which does not affect the essential content of the present application. The embodiments of the present application and the features in the embodiments can be arbitrarily combined with each other without conflict.

Claims

1. A neutron diffraction stress measurement apparatus based on spatial coordinate measurement, characterized by, Comprise: Autonomous navigation trolley (1), attitude adjustment system (2), space measurement sensor (4), neutron detector (3), sample table (5) and main controller; The attitude adjustment system (2) is fixedly installed on the autonomous navigation trolley (1), and the neutron detector (3) is detachably installed on the attitude adjustment system (2), and the autonomous navigation trolley (1) is used to carry the neutron detector (3) and the attitude adjustment system (2) to move to the vicinity of the specified position in the measurement space; The space measurement sensor (4) is used to measure the actual position and attitude of the neutron detector (3) in the measurement space and send the measurement data to the main controller; The main controller is electrically connected with the autonomous navigation trolley (1), the attitude adjustment system (2) and the space measurement sensor (4) respectively, is used to send motion instructions, receive measurement data, perform coordinate transformation operation and kinematics inverse solution operation, and output control signals; The sample table (5) is arranged in the measurement range of the neutron detector (3) and is used to carry the measured sample (6) and adjust the position and attitude of the sample (6).

2. The neutron diffraction stress measurement apparatus based on spatial coordinate measurement according to claim 1, characterized in that, The attitude adjustment system (2) is a precise six-degree-of-freedom parallel mechanism, which is used to adjust the six-degree-of-freedom position and attitude of the neutron detector (3) to compensate for the motion error of the autonomous navigation trolley (1).

3. The neutron diffraction stress measurement apparatus based on spatial coordinate measurement according to claim 1, characterized in that, The space measurement sensor (4) is a laser tracker or a machine vision sensor, which is used to output three-dimensional position and attitude data of the neutron detector (3) in the measurement space.

4. The neutron diffraction stress measurement apparatus based on spatial coordinate measurement according to claim 2, characterized in that, Further comprising a probe motion mechanism, which is connected with the space measurement sensor (4) and is used to drive the space measurement sensor (4) to adjust the spatial position.

5. The neutron diffraction stress measurement apparatus based on spatial coordinate measurement according to claim 4, characterized in that, Further comprising a detector controller, which is electrically connected with the neutron detector (3) and is used to control the working state of the neutron detector (3) and record the measurement data; The detector controller receives the instructions of the main controller, controls the neutron detector (3) to open / close the diffracted neutron beam measurement function, and records the measured neutron diffraction data in real time and feeds back to the main controller.

6. A neutron diffraction stress measurement method based on spatial coordinate measurement, characterized by, The method is applied to the neutron diffraction stress measurement device based on space coordinate measurement in claim 5, and the method comprises the following steps: Step S1: the main controller obtains a target measurement position of the neutron detector (3), sends a motion instruction to the autonomous navigation trolley (1), and the autonomous navigation trolley (1) carries the neutron detector (3) and the attitude adjustment system (2) to move to the vicinity of the target measurement position according to the instruction; Step S2: the main controller synchronously sends an adjustment instruction to the probe motion mechanism, and the probe motion mechanism drives the space measurement sensor (4) to move to a measurement station corresponding to the target measurement position; Step S3: the space measurement sensor (4) measures the position and attitude of the neutron detector (3), and sends the measured original data to the main controller; Step S4: the main controller receives the original data, performs coordinate transformation operation and kinematics inverse solution operation, and outputs control signals to the attitude adjustment system (2) and the neutron detector (3); Step S4: The main controller performs coordinate transformation operation on the original data to convert it into actual position and posture data of the neutron detector (3) in the coordinate system of the spectrometer; Step S5: The main controller calculates the deviation vector between the target measurement position and the actual position and posture, and performs inverse kinematics operation according to the deviation vector to obtain joint space compensation amount for compensating the position and posture error; Step S6: The main controller sends control signals to the posture adjustment system (2) according to the joint space compensation amount, and the posture adjustment system (2) drives the neutron detector (3) to move to complete the position and posture error compensation; Step S7: If the actual position and posture of the neutron detector (3) meets the measurement requirements, the main controller sends a measurement instruction to the detector controller, and the detector controller controls the neutron detector (3) to start the measurement function to complete the neutron diffraction stress measurement at the current station and record the measurement data.

7. The neutron diffraction stress measurement method based on spatial coordinate measurement according to claim 6, characterized in that, The inverse kinematics operation in step S5 is a motion control algorithm for the posture adjustment system (2), which is used to calculate the displacement amount required by each axis of the precise six-degree-of-freedom parallel mechanism in joint space according to the deviation vector, so as to realize precise compensation of the six degrees of freedom of the neutron detector (3).

8. The neutron diffraction stress measurement method based on spatial coordinate measurement according to claim 6, characterized in that, The measurement accuracy of the space measurement sensor (4) in step S3 is not less than 0.1 mm, and the three-dimensional coordinate and posture angle data of the neutron detector (3) are output in real time.

9. The neutron diffraction stress measurement method based on spatial coordinate measurement according to claim 6, characterized in that, The method for adjusting the position of the space measurement sensor (4) by the probe motion mechanism in step S2 includes: Taking unobstructed and straight linearity of the measurement path as the adjustment target, it is ensured that there is no obstacle between the space measurement sensor (4) and the neutron detector (3) to interfere with the measurement signal.

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