Force sensor assembly quality determination method and apparatus, electronic device, storage medium, and product

Abstract

The application provides a method and device for determining assembly quality of a force sensor, electronic equipment, a storage medium and a product. The method comprises: obtaining decoupling output information and bridge impedance information of the force sensor after each screw required for assembling the force sensor is tightened to a set torque or a set angle; determining a decoupling output change and a bridge impedance change of each screw relative to the screw of the previous assembly stage based on the decoupling output information and the bridge impedance information corresponding to the screw tightened in the adjacent assembly stage; and determining assembly quality information representing whether an assembly anomaly occurs based on at least one of the decoupling output change and the bridge impedance change. Thus, the scheme of the application obtains the decoupling output change and the bridge impedance change of the force sensor during the tightening of each screw, which is used to determine the assembly quality, so that the quality problem occurring in the assembly process can be found in time, thereby improving the assembly efficiency.

Description

Technical Field

[0001] This application relates to the field of sensor technology, and in particular to a method, apparatus, electronic device, storage medium, and product for determining the assembly quality of a force sensor. Background Technology

[0002] Force sensors are widely used in robot end effector force control, precision assembly, grinding and polishing, drag teaching, collision detection, testing fixtures, and medical rehabilitation equipment. In practical applications, force sensors need to be mounted to the robot wrist, joints, end effector, or testing equipment using screws, flanges, adapters, or clamps. During assembly, various factors may introduce additional assembly pre-stress into the force sensor's elastomer or sensitive element, which can reduce the measurement accuracy of the force sensor after assembly. Furthermore, existing technologies cannot accurately detect assembly quality issues during the assembly process. Summary of the Invention

[0003] In view of this, embodiments of this application provide a method, apparatus, electronic device, storage medium, and product for determining the assembly quality of a force sensor, aiming to determine the assembly quality in a timely and accurate manner and improve assembly efficiency.

[0004] The technical solution of this application embodiment is implemented as follows: In a first aspect, embodiments of this application provide a method for determining the assembly quality of a force sensor, the method comprising: For each screw required to assemble the force sensor, obtain the decoupling output information and bridge impedance information of the force sensor after the screw is tightened to a set torque or a set angle; Based on the decoupling output information and bridge impedance information corresponding to the screws tightened in adjacent assembly stages, determine the decoupling output change and bridge impedance change of each screw relative to the screw in the previous assembly stage. Assembly quality information characterizing whether an assembly is abnormal is determined based on at least one of the decoupling output change and the bridge impedance change.

[0005] In some embodiments, the method further includes: Obtain the initial decoupling output information of the force sensor when the screws are not assembled; The total decoupling output change is determined based on the total decoupling output information of the force sensor after all the screws are assembled and the initial decoupling output information. The determination of assembly quality information characterizing whether an assembly anomaly exists based on at least one of the decoupling output change and the bridge impedance change includes: The assembly quality information is determined based on at least one of the decoupling output change and the bridge impedance change, as well as the total decoupling output change; the assembly quality information includes first information indicating normal assembly, second information indicating the need for additional compensation, and third information indicating assembly abnormality.

[0006] In some embodiments, determining the assembly quality information based on at least one of the decoupling output change and the bridge impedance change, and the total decoupling output change, includes: A first score characterizing preload consistency is determined based on at least one of the normalized decoupling output change and the normalized bridge impedance change, as well as the normalized total decoupling output change. If it is determined that the first score is less than the first threshold, then the assembly quality information is determined to be the first information indicating that the assembly is normal. If it is determined that the first score is greater than or equal to the first threshold and less than the second threshold, then the assembly quality information is determined to be the second information indicating that additional compensation is required. If the first score is determined to be greater than or equal to the second threshold, then the assembly quality information is determined to be the third information indicating an assembly abnormality.

[0007] In some embodiments, determining a first score characterizing preload consistency based on at least one of the normalized decoupling output change and the normalized bridge impedance change, and the normalized total decoupling output change, includes: Based on the normalized total decoupling output change, a first index value characterizing the overall zero-point offset is determined. Based on the normalized decoupling output change, a second index value characterizing the degree of single-step zero-point offset is determined. Based on the decoupling output change corresponding to two screws in a symmetrical or diagonal assembly, a third index value characterizing the consistency of the symmetrical or diagonal screw assembly is determined. Based on the normalized change in bridge impedance, a fourth index value characterizing the change in bridge impedance is determined. The first score is determined based on at least one of the second, third, and fourth indicator values, the first indicator value, and the weights corresponding to each indicator value.

[0008] In some embodiments, determining the assembly quality information based on at least one of the decoupling output change and the bridge impedance change, and the total decoupling output change, further includes: If the value of the first indicator is determined to be greater than or equal to a preset first indicator threshold, the assembly quality information is determined as the third information indicating an assembly abnormality; or, If the value of the second indicator is determined to be greater than or equal to a preset second indicator threshold, the assembly quality information is determined as the third information indicating an assembly abnormality; or, If the value of the third indicator is determined to be greater than or equal to a preset third indicator threshold, the assembly quality information is determined to be the third information indicating an assembly abnormality; or, If the value of the fourth indicator is determined to be greater than or equal to the preset threshold value of the fourth indicator, the assembly quality information is determined to be the third information indicating an assembly abnormality.

[0009] In some embodiments, the method further includes: If the assembly quality information is determined to be either the first information indicating normal assembly or the second information indicating the need for additional compensation, then the zero-point vector is determined based on the original channel output information of the force sensor after all the screws have been assembled and there is no external load. When the force sensor is subjected to an external load, the decoupling output information of the force sensor is determined based on the zero-point vector, the original channel output information under external load, and the decoupling matrix.

[0010] In some embodiments, the method further includes: If the assembly quality information is determined to be the second type of information requiring additional compensation, then the decoupling matrix correction amount is determined based on the assembly response feature information and the first mapping relationship. The assembly response feature information includes at least one of the following: the normalized total decoupling output change, the normalized bridge impedance change, the tightening torque corresponding to each screw, the change in temperature value after all screws are assembled and before all screws are assembled, a first index value characterizing the overall zero-point offset, a second index value characterizing the single-step zero-point offset, a third index value characterizing the consistency of symmetrical or diagonal screw assembly, a fourth index value characterizing the bridge impedance change, and a first score characterizing the consistency of preload. The first mapping relationship includes the mapping relationship between the assembly response feature information and the decoupling matrix correction amount. Update the decoupling matrix based on the aforementioned decoupling matrix correction amount; When the force sensor is subjected to an external load, the decoupling output information of the force sensor is determined based on the zero-point vector, the original channel output information under external load, and the updated decoupling matrix.

[0011] Secondly, embodiments of this application provide an assembly quality determination device for a force sensor, the device comprising: The acquisition module is used to acquire, for each screw required for assembling the force sensor, the decoupling output information and bridge impedance information of the force sensor after the screw is assembled to a set torque or a set rotation angle; The information processing module determines the decoupling output change and bridge impedance change for each screw based on the decoupling output information and bridge impedance information corresponding to adjacent assembled screws. An assembly quality determination module is used to determine assembly quality information characterizing whether an assembly is abnormal based on at least one of the decoupling output change and the bridge impedance change.

[0012] Thirdly, embodiments of this application provide an electronic device, the electronic device including a processor and a memory for storing a computer program capable of running on the processor, wherein the processor, when running the computer program, performs the steps of the method described in the first aspect.

[0013] Fourthly, embodiments of this application provide a storage medium storing a computer program, which, when executed by a control device, implements the steps of the method described in the first aspect.

[0014] Fifthly, embodiments of this application provide a computer program product, including a computer program that, when executed by a controlled device, implements the steps of the method described in the first aspect.

[0015] The technical solution provided in this application, for each screw required for assembling a force sensor, acquires the decoupling output information and bridge impedance information of the force sensor after the screw is tightened to a set torque or set angle; based on the decoupling output information and bridge impedance information corresponding to screws tightened in adjacent assembly stages, determines the change in decoupling output and bridge impedance of each screw relative to the screw in the previous assembly stage; and based on at least one of the change in decoupling output and bridge impedance, determines assembly quality information characterizing whether there is an assembly abnormality. Thus, the solution of this application acquires the changes in the decoupling output and bridge impedance of the force sensor during the screw tightening process, which is used to determine the assembly quality and to promptly and accurately detect quality problems occurring during assembly, such as excessive local preload, abnormal contact surfaces, uneven diagonal preload, etc., thereby improving assembly efficiency. Attached Figure Description

[0016] Figure 1 This is a flowchart illustrating the method for determining the assembly quality of a force sensor provided in an embodiment of this application. Figure 2 This is a schematic diagram of the assembly quality determination device for a force sensor provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0017] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0018] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this application.

[0019] Force sensors are widely used in robot end effector force control, precision assembly, grinding and polishing, drag teaching, collision detection, testing fixtures, and medical rehabilitation equipment. In practical applications, force sensors need to be installed on the robot wrist, joints, end effector, or testing equipment using screws, flanges, adapters, or clamps. During assembly, various factors may introduce additional assembly prestress into the force sensor's elastomer or sensitive element, which can lead to a decrease in the measurement accuracy of the force sensor after assembly.

[0020] In related technologies, there are several methods for correcting sensor output based on assembly prestress.

[0021] Related technology 1: After the force sensor is installed, the current zero point is taken as the zero point when there is no external load output.

[0022] Related Technique 2: Directly use the factory-calibrated decoupling matrix. This method assumes that the factory-calibrated decoupling matrix remains applicable after the sensor is assembled into the customer's equipment.

[0023] Related Technique 3: Relying on operator experience to control screw torque. This method records the target torque and uses a torque wrench to control the tightening torque.

[0024] Related Technique 4: Complete Recalibration. This method involves recalibrating after assembly to obtain compensation parameters in the installed state, but it requires specialized loading equipment.

[0025] This application considers that during assembly, the screw tightening sequence, screw tightening torque, flange flatness, foreign objects on the contact surface, stiffness of the adapter, and local pressure state of the mounting surface may all introduce additional assembly prestress to the sensor elastomer or sensitive element. This assembly prestress can lead to phenomena such as zero-point offset, channel output imbalance, increased inter-axis coupling, and decreased consistency due to repeated disassembly and assembly, which can reduce the measurement accuracy of the sensor after installation. The method of related technology one can only eliminate part of the static zero-point offset and cannot determine the screw preload, thus failing to identify assembly problems such as overtightening of a single screw, uneven diagonal preload, flange tilt, or abnormal contact surface. Considering that the actual assembly preload may change the initial stress state of the elastomer and the bridge state of the sensitive element, the method of related technology two is prone to causing the factory decoupling matrix to be inapplicable to the sensor after installation. Related technology three does not link the output change and bridge impedance change after tightening each screw to the screw number and tightening sequence, and cannot form a traceable basis for judging the assembly state. Furthermore, screw tightening torque only reflects the external input applied to the screw by the tightening tool and cannot be equated to the actual assembly prestress borne by the sensor elastomer. Even if multiple screws have the same tightening torque, differences in flange flatness, contact surface roughness, local foreign matter, thread friction coefficient, mounting surface stiffness, and tightening sequence can still lead to uneven prestress within the sensor elastomer, causing phenomena such as zero-point offset, sudden changes in torque path, increased inter-axis coupling, or abnormal bridge impedance. Therefore, simply recording or controlling screw torque cannot accurately evaluate the actual working state of the force sensor after assembly. Related technology four is complex to operate, costly, and difficult to implement frequently at customer sites, robot production lines, or after-sales maintenance.

[0026] In summary, the shortcomings of the relevant technologies are as follows: 1. Zeroing after installation can only handle zero-point offset, but cannot determine whether the assembly preload is consistent.

[0027] 2. Overtightening of a single screw, uneven pre-tightening of diagonal screws, or abnormal contact surfaces may cause sudden changes in the torque path, but the relevant technology lacks monitoring of the assembly process.

[0028] 3. The torque value alone cannot directly reflect the actual assembly stress experienced by the sensor elastomer and the bridge circuit sensing element.

[0029] 4. The factory-made decoupling matrix did not take into account the prestress of the equipment, resulting in poor measurement consistency after repeated disassembly and reassembly.

[0030] 5. Recalibrating the six dimensions after complete assembly is costly and inefficient, making it unsuitable for batch assembly and on-site maintenance.

[0031] 6. The relevant technologies lack a tiered judgment of normal, compensable, and abnormal assembly states, which makes it easy to simply reset serious assembly abnormalities and continue using the equipment.

[0032] Therefore, there is a need for a method and system that can detect the consistency of assembly preload using data such as the sensor's own output and bridge impedance during the force sensor assembly process, and perform zero-point compensation or decoupling matrix micro-correction when the assembly state is acceptable.

[0033] In various embodiments of this application, the changes in the decoupled output of the force sensor and the changes in the bridge impedance of each screw are acquired during the screw tightening process to determine the assembly quality and to promptly and accurately detect quality problems that occur during the assembly process, such as excessive local preload, abnormal contact surfaces, uneven diagonal preload, etc., thereby improving assembly efficiency.

[0034] The solution proposed in this application can be applied to three-dimensional force sensors, joint torque sensors, multi-dimensional force / torque sensors, and other force sensors employing resistance strain gauge bridge circuits. The following explanation uses a six-dimensional force sensor as an example. A six-dimensional force sensor, also known as a six-axis force / torque sensor, can simultaneously detect three-dimensional forces Fx, Fy, and Fz, as well as three-dimensional torques Mx, My, and Mz. Six-dimensional force sensors are typically calibrated at the factory using a standard loading device to obtain the factory zero point, sensitivity matrix, and decoupling matrix.

[0035] This application provides a method for determining the assembly quality of a force sensor, applicable to electronic devices, such as... Figure 1 As shown, the method includes: Step 101: For each screw required to assemble the force sensor, obtain the decoupling output information and bridge impedance information of the force sensor after the screw is tightened to a set torque or a set angle. Step 102: Based on the decoupling output information and bridge impedance information corresponding to the screws tightened in adjacent assembly stages, determine the decoupling output change and bridge impedance change of each screw relative to the screw in the previous assembly stage. Step 103: Determine assembly quality information characterizing whether there is an assembly abnormality based on at least one of the decoupling output change and the bridge impedance change.

[0036] In practical applications, the set torque can refer to the target torque or a set percentage of the target torque (such as 30% or 60% of the target torque), and the set angle can be the angle of screw rotation when tightening the screw (such as 360°). In this application embodiment, the specific values ​​of the set torque and set angle are not limited.

[0037] After each screw is tightened to the set torque or set angle, a preset stabilization time can be waited for, and / or after the six-dimensional output change rate and bridge impedance change rate are less than the preset stabilization threshold, assembly process data can be collected. The assembly process data includes the six-dimensional decoupling output Wk (i.e., decoupling output information) and the bridge impedance Zk (i.e., bridge impedance information). The electronic equipment acquires the collected assembly process data.

[0038] In practical applications, after each screw is tightened to the set torque or set angle, the screw number Sk, tightening sequence Ok, tightening torque τk, and original channel output can be displayed. Six-dimensional decoupled output Bridge impedance The temperature Tk and the sampling time tk are bound (i.e. stored accordingly) to form the assembly process data corresponding to each screw.

[0039] Specifically, the assembly process of the six-dimensional force sensor includes n assembly stages, where the k-th assembly stage corresponds to a screw or a tightening action, and k = 1, 2, ..., n. The raw channel output of the k-th assembly stage is: Where r is the original number of channels. This represents the output value of the i-th original acquisition channel in the k-th assembly stage; The six-dimensional decoupling output of the kth assembly stage is: ,in, , , These represent the three-dimensional force outputs at the k-th assembly stage. , , These represent the three-dimensional torque output at the k-th assembly stage; The bridge impedance at the kth assembly stage is: Where m is the number of bridge impedance acquisition channels. This represents the impedance value of the j-th bridge circuit in the k-th assembly stage; The temperature of the kth assembly stage is: Tk; The assembly process data (or assembly stage response vector) for the kth assembly stage is as follows: The temperature Tk can specifically be the internal temperature of the sensor, the temperature near the elastomer, the temperature near the bridge circuit, or the ambient temperature of the assembly station. In some embodiments, the temperature near the elastomer or sensitive bridge circuit can be preferentially used. When there is no internal temperature acquisition condition, the ambient temperature can be used as Tk. The sampling time tk can be: after the screw reaches the preset torque or preset rotation angle, after a preset stabilization time, and / or after the six-dimensional output change rate or bridge impedance change rate is lower than the preset stabilization threshold, the sampling time can be: when actually collecting assembly process data (excluding the sampling time tk), multiple samples can be taken within the acquisition time window and the average value can be taken, and the center time or end time of the window can be used as tk.

[0040] After obtaining the assembly stage response vector, the data for each assembly stage is compared with the data for the previous assembly stage (assembly process data collected when assembling the previous screw) to obtain the change in assembly stage response relative to the previous assembly stage, including the six-dimensional decoupling output change (i.e., the aforementioned decoupling output change) and the change in bridge impedance. The change in assembly stage response for the k-th assembly stage relative to the previous assembly stage includes:

[0041] in, This indicates the change in the original channel output. This represents the change in six-dimensional force / torque output. This represents the change in bridge impedance. This represents the temperature change. By analyzing the response vectors and changes during the assembly stages, the impact of each screw or tightening action on the original channel output, six-dimensional decoupled output, bridge impedance, and temperature of the six-dimensional force sensor can be obtained. This provides a basis for subsequent preload consistency judgment and compensation parameter generation. Here, the original channel output Yk refers to the electrical signal acquired by each original acquisition channel or bridge circuit of the sensor in the k-th assembly stage under conditions of no external load. This can be the bridge differential voltage, amplified voltage, or ADC sampled value, etc. The six-dimensional decoupled output Wk is the equivalent force / torque output in six directions (Fx, Fy, Fz, Mx, My, Mz) calculated based on the factory decoupling matrix D0 after zero-point subtraction and temperature compensation of the original channel output. It is used to characterize the six-dimensional bias caused by assembly preload.

[0042] Specifically, the change in the six-dimensional decoupling output of the k-th assembly stage relative to the previous assembly stage is: ,in,

[0043] The change in bridge impedance at the k-th assembly stage relative to the previous assembly stage is: Where m represents the total number of sensor bridges, .

[0044] Based on the six-dimensional decoupling output change, the single-step abrupt change index Q2 and the symmetry index Q3 can be determined. The single-step abrupt change index Q2 is used to determine whether a screw tightening action introduces significant local assembly prestress. The symmetry index Q3 is used to determine whether there are significant differences in the preload response of symmetrical or diagonally opposite screws. Large differences may indicate problems such as uneven diagonal preload, flange tilting, or abnormal contact at the mounting surface. Based on the bridge impedance change, the impedance consistency index Q4 can be determined to evaluate whether abnormal changes occur in the bridge impedance during screw tightening.

[0045] Thresholds corresponding to the above indicators can be set, and the assembly abnormality can be determined by comparing the indicators with the thresholds. If an assembly abnormality is determined, the electronic device can prompt the assembly personnel to retighten a screw, check the contact surface, or reassemble through the display screen and / or audio equipment.

[0046] Understandably, the solution in this application acquires the changes in the decoupled output of the force sensor and the changes in the bridge impedance of each screw during assembly, in order to determine the assembly quality and to promptly and accurately detect quality problems that occur during assembly, such as excessive local preload, abnormal contact surfaces, uneven diagonal preload, etc., thereby improving assembly efficiency.

[0047] In some embodiments, the method further includes: Obtain the initial decoupling output information of the force sensor when the screws are not assembled; The total decoupling output change is determined based on the total decoupling output information of the force sensor after all the screws are assembled and the initial decoupling output information. The determination of assembly quality information characterizing whether an assembly anomaly exists based on at least one of the decoupling output change and the bridge impedance change includes: The assembly quality information is determined based on at least one of the decoupling output change and the bridge impedance change, as well as the total decoupling output change; the assembly quality information includes first information indicating normal assembly, second information indicating the need for additional compensation, and third information indicating assembly abnormality.

[0048] In practical applications, the sensor pre-assembly reference data under no external load conditions can be obtained before assembly begins, including the original channel output Y0, the six-dimensional decoupling output W0 (i.e., the initial decoupling output information), the bridge impedance Z0, and the temperature T0.

[0049] The change in response at the k-th assembly stage relative to the baseline state before assembly is defined as:

[0050] It is understandable that after all screws are assembled, the total decoupling output information corresponding to the six-dimensional force sensor, that is, the six-dimensional decoupling output Wn collected in the nth assembly stage, is the total decoupling output change. The overall offset index Q1 can be calculated based on the total decoupling output change. This index is used to evaluate the overall zero-point offset of the six-dimensional force sensor relative to the pre-assembly reference state after all screws have been tightened, and can determine whether the overall zero-point offset is too large after all screws have been tightened. A threshold corresponding to the overall offset index Q1 can be set, and assembly abnormalities can be determined by comparing Q1 with the corresponding threshold.

[0051] Furthermore, the preload consistency index Q (i.e., the first score) can be calculated by combining the overall deviation index Q1, the single-step mutation index Q2, the symmetry index Q3, and the impedance consistency index Q4. Alternatively, index Q can be obtained by combining the overall deviation index Q1 with at least one of the single-step mutation index Q2, the symmetry index Q3, and the impedance consistency index Q4. Thus, index Q can be used to determine the first information indicating normal assembly, the second information indicating the need for additional compensation, or the third information indicating abnormal assembly.

[0052] Since the six-dimensional force / torque output and bridge impedance belong to different physical dimensions, they cannot be directly added or compared. Therefore, various indicators are normalized and unified into dimensionless indicators before comprehensive evaluation.

[0053] Based on this, in some embodiments, determining the assembly quality information based on at least one of the decoupling output change and the bridge impedance change, and the total decoupling output change, includes: A first score characterizing preload consistency is determined based on at least one of the normalized decoupling output change and the normalized bridge impedance change, as well as the normalized total decoupling output change. If it is determined that the first score is less than the first threshold, then the assembly quality information is determined to be the first information indicating that the assembly is normal. If it is determined that the first score is greater than or equal to the first threshold and less than the second threshold, then the assembly quality information is determined to be the second information indicating that additional compensation is required. If the first score is determined to be greater than or equal to the second threshold, then the assembly quality information is determined to be the third information indicating an assembly abnormality.

[0054] Specifically, the normalized six-dimensional decoupling output change of the k-th assembly stage relative to the previous assembly stage is defined as: ,in,

[0055] here, , , These are the full-scale values ​​of the triaxial forces, , , These are the full-scale values ​​of the three-dimensional torques, respectively.

[0056] The normalized six-dimensional decoupling output change of the k-th assembly stage relative to the pre-assembly baseline state is defined as: ,in,

[0057] It is understandable that when k is n, This represents the normalized total decoupling output change. Here, the normalized six-dimensional decoupling output change for each assembly stage relative to the pre-assembly baseline state is calculated. This is mainly used to track the cumulative offset process, determine from which screw or tightening stage the offset started to accumulate, and support process early warning and assembly fingerprint traceability.

[0058] The normalized bridge impedance change of the k-th assembly stage relative to the previous assembly stage is defined as: ,in, , This represents the reference impedance value of the j-th bridge circuit before assembly. This reference impedance value can be understood as the impedance value of the j-th bridge circuit under the same assembly environment before and after assembly, without any external load. This reference impedance value can be the bridge circuit impedance Z0 in the reference data before assembly.

[0059] Based on at least one of the normalized decoupling output change and the normalized bridge impedance change, as well as the normalized total decoupling output change, a first score characterizing preload consistency is determined. Specifically, the overall offset index Q1 can be determined based on the normalized total decoupling output change; the single-step mutation index Q2 and the symmetry index Q3 can be calculated based on the normalized decoupling output change; and the impedance consistency index Q4 can be calculated based on the normalized bridge impedance change. The first score characterizing preload consistency is determined by at least one of the normalized decoupling output change and the normalized bridge impedance change, as well as the normalized total decoupling output change. That is, the first score can be jointly determined by Q1, Q2, Q3, and Q4, or jointly by Q1, Q2, and Q3, or jointly by Q1 and Q4. Thus, based on index Q, first information indicating normal assembly, second information indicating the need for additional compensation, or third information indicating assembly abnormality is determined.

[0060] Specifically, after obtaining the preload consistency index Q, if it is determined that index Q is less than the first threshold TH1, then the assembly preload consistency of the six-dimensional force sensor is considered to be good, and no obvious abnormal preload stress is introduced during the assembly process. The assembly quality information is determined as the first information indicating normal assembly. If it is determined that index Q is greater than or equal to the first threshold TH1 and less than the second threshold TH2, then the assembly preload is considered to have a slight inconsistency, but it is within the compensable range. The assembly quality information is determined as the second information indicating that additional compensation is needed. If it is determined that index Q is greater than or equal to the second threshold TH2, then the degree of inconsistency in the assembly preload of the six-dimensional force sensor is considered to be large. The assembly quality information is determined as the third information indicating abnormal assembly.

[0061] In some embodiments, the specific values ​​of the first threshold and the second threshold can be determined according to any of the following methods: 1. The allowable zero-point drift, allowable inter-axis coupling variation, and allowable bridge impedance variation of the sensor product are preset.

[0062] 2. The first threshold is determined based on the statistical distribution of the Q-values ​​(i.e., the first score) of multiple qualified assembly samples. For example, the first threshold can be the mean of the Q-values ​​of M qualified samples plus n times the standard deviation, where the standard deviation is the standard deviation of the Q-values ​​of M qualified samples. n can be selected based on the risk of misjudgment, and is generally 2 or 3. 3. Determined based on experimental data from three types of samples: normal assembly, slightly uneven assembly, and abnormal assembly; 4. Adjustments will be made based on the customer's permissible measurement error or consistency requirements for repeated disassembly and assembly.

[0063] In some embodiments, the original channel output change ΔY and temperature change ΔT can also be normalized and used as inputs to auxiliary diagnostic, temperature correction, and decoupling matrix micro-correction models. The temperature change can be normalized based on the temperature compensation coefficient or the allowable temperature change range.

[0064] In some embodiments, determining a first score characterizing preload consistency based on at least one of the normalized decoupling output change and the normalized bridge impedance change, and the normalized total decoupling output change, includes: Based on the normalized total decoupling output change, a first index value characterizing the overall zero-point offset is determined. Based on the normalized decoupling output change, a second index value characterizing the degree of single-step zero-point offset is determined. Based on the decoupling output change corresponding to two screws in a symmetrical or diagonal assembly, a third index value characterizing the consistency of the symmetrical or diagonal screw assembly is determined. Based on the normalized change in bridge impedance, a fourth index value characterizing the change in bridge impedance is determined. The first score is determined based on at least one of the second, third, and fourth indicator values, the first indicator value, and the weights corresponding to each indicator value.

[0065] Based on the above example, specifically, the formula for calculating the overall offset index Q1 is as follows: ,Right now The L2 norm; the formula for calculating the single-step mutation index Q2 is: The formula for calculating the symmetry index Q3 is as follows: Where P is the set of assembly stage numbers for symmetrical or diagonal screws, and p and q represent the assembly stage numbers corresponding to a set of screws in symmetrical or diagonal positions, respectively. A large Q3 indicates a significant difference in the preload response of symmetrical or diagonal screws, which may indicate uneven diagonal preload, flange tilt, or abnormal contact of the mounting surface. The formula for calculating the impedance consistency index Q4 is as follows: ,in, This represents the change in normalized bridge impedance at the k-th assembly stage relative to the previous assembly stage. |∞ is the infinity norm, used to characterize the maximum value among the normalized changes in impedance of each bridge circuit.

[0066] In some embodiments, the impedance conformance index Q4 can also be evaluated using the standard deviation form. The formula for calculating the impedance conformance index Q4' evaluated using the standard deviation form is as follows: , where std( ) represents the standard deviation calculation, and Q4' represents the maximum normalized bridge impedance standard deviation in different assembly stages, which is used to evaluate the degree of fluctuation of the normalized impedance of the same bridge in different assembly stages.

[0067] The formula for calculating the preload consistency index Q (i.e., the first score) based on Q1, Q2, Q3, and Q4 (or replaced by Q4') is as follows: ,in, , , as well as The weights are Q1, Q2, Q3, and Q4, respectively, where Q4 can also be replaced by Q4', and a1+a2+a3+a4=1. It can be understood that the preload consistency index Q can also be determined based on Q1, and at least one of Q2, Q3, and Q4 (or Q4') combined with its corresponding weights. For example... or (where Q4 can be replaced with Q4') etc., and the sum of all weights used to calculate the preload consistency index Q is 1. This application embodiment does not limit the specific index content involved in the calculation of the preload consistency index Q.

[0068] Understandably, the weighting coefficients for each indicator can be set based on the sensor structure, number of screws, assembly process requirements, bridge sensitivity, and statistical results of historical qualified assembly samples. Preferably, the weighting coefficients and relevant thresholds can be calibrated using qualified assembly samples, samples of single screws being overtightened, samples of uneven diagonal preload, samples of flange tilting, and samples of abnormal contact surfaces. They can also be adjusted based on the sensor range, the allowable range of bridge impedance variation, the customer's site allowable error, and the consistency requirements for repeated disassembly and assembly.

[0069] In some embodiments, determining the assembly quality information based on at least one of the decoupling output change and the bridge impedance change, and the total decoupling output change, further includes: If the value of the first indicator is determined to be greater than or equal to a preset first indicator threshold, the assembly quality information is determined as the third information indicating an assembly abnormality; or, If the value of the second indicator is determined to be greater than or equal to a preset second indicator threshold, the assembly quality information is determined as the third information indicating an assembly abnormality; or, If the value of the third indicator is determined to be greater than or equal to a preset third indicator threshold, the assembly quality information is determined to be the third information indicating an assembly abnormality; or, If the value of the fourth indicator is determined to be greater than or equal to the preset threshold value of the fourth indicator, the assembly quality information is determined to be the third information indicating an assembly abnormality.

[0070] Based on the above example, a first threshold value THQ1 is set for the overall offset index Q1, a second threshold value THQ2 is set for the single-step mutation index Q2, a third threshold value THQ3 is set for the symmetry index Q3, and a fourth threshold value THQ4 is set for the impedance consistency index Q4. If the overall offset index Q1 is greater than or equal to the preset first threshold value THQ1, it indicates that the overall zero-point offset is too large after all screws are tightened, thus determining an assembly abnormality. If the single-step mutation index Q2 is greater than or equal to the preset second threshold value THQ2, it indicates that a screw tightening action may have introduced significant local assembly prestress, thus determining an assembly abnormality. If the symmetry index Q3 is greater than or equal to the preset third threshold value THQ3, it indicates that there is a significant difference in the pre-tightening response of symmetrical screws or diagonal screws, thus determining an assembly abnormality. If the impedance consistency index Q4 is greater than or equal to the preset fourth threshold value THQ4, it indicates that the bridge impedance undergoes a significant abnormal change during screw tightening, thus determining an assembly abnormality. Here, the specific values ​​of the first, second, third, and fourth threshold values ​​are not limited in this embodiment of the application.

[0071] Assembly stress introduced during screw assembly can easily cause the sensor zero point to shift. If not corrected, the sensor will produce a large error when it is loaded for measurement. Existing technology cannot compensate and correct for different assembly quality conditions.

[0072] Based on this, in some embodiments, the method further includes: If the assembly quality information is determined to be either the first information indicating normal assembly or the second information indicating the need for additional compensation, then the zero-point vector is determined based on the original channel output information of the force sensor after all the screws have been assembled and there is no external load. When the force sensor is subjected to an external load, the decoupling output information of the force sensor is determined based on the zero-point vector, the original channel output information under external load, and the decoupling matrix.

[0073] In practical applications, before assembly, the original channel output of the six-dimensional force sensor is as follows: , where r is the original number of channels; The six-dimensional force / torque output is denoted as: Where Fx, Fy, and Fz represent triaxial force outputs, and Mx, My, and Mz represent triaxial torque outputs.

[0074] The factory zero-point vector of the six-dimensional force sensor is denoted as: The decoupling matrix can be the factory decoupling matrix D0, thus the factory compensation model is... The factory zero point b0 is the reference zero point vector obtained by the sensor under factory calibration fixtures, no external load, and specified temperature conditions. It is a fixed reference parameter and is used as the factory reference and zero point deduction reference.

[0075] After assembly, N sets of raw channel output data were collected under no external load conditions, and denoted as: .

[0076] The assembly zero-point vector is defined as: Where bm represents the assembly zero-point vector of the six-dimensional force sensor in the current assembly state, and N represents the number of samplings of the original channel output data collected after assembly to calculate the zero-point vector.

[0077] If the assembly quality information is determined to be the primary information indicating normal assembly, i.e., the assembly state is judged to be normal, the system uses the latest calculated assembly zero-point vector for compensation. When the six-dimensional force sensor is subjected to an external load, the compensated six-dimensional force / torque output (i.e., decoupled output information) is as follows: Here, Y refers to the original channel output of the six-dimensional force sensor when it is subjected to an external load, and Wc represents the six-dimensional force / torque output of the six-dimensional force sensor after assembly zero-point vector compensation when it is subjected to an external load.

[0078] For sensors with slightly poor preload consistency and non-uniform assembly stress, correcting the zero point alone cannot eliminate the changes in interdimensional coupling characteristics caused by assembly stress, and the sensor's accuracy will still decrease.

[0079] Based on this, in some embodiments, the method further includes: If the assembly quality information is determined to be the second type of information requiring additional compensation, then the decoupling matrix correction amount is determined based on the assembly response feature information and the first mapping relationship. The assembly response feature information includes at least one of the following: the normalized total decoupling output change, the normalized bridge impedance change, the tightening torque corresponding to each screw, the change in temperature value after all screws are assembled and before all screws are assembled, a first index value characterizing the overall zero-point offset, a second index value characterizing the single-step zero-point offset, a third index value characterizing the consistency of symmetrical or diagonal screw assembly, a fourth index value characterizing the bridge impedance change, and a first score characterizing the consistency of preload. The first mapping relationship includes the mapping relationship between the assembly response feature information and the decoupling matrix correction amount. Update the decoupling matrix based on the aforementioned decoupling matrix correction amount; When the force sensor is subjected to an external load, the decoupling output information of the force sensor is determined based on the zero-point vector, the original channel output information under external load, and the updated decoupling matrix.

[0080] If the assembly quality information is determined to be the second piece of information requiring additional compensation, i.e., the assembly state is determined to be a compensable state, then further decoupling matrix micro-correction is performed based on the aforementioned assembly zero-point vector compensation. The decoupling matrix correction amount is denoted as... The corrected decoupling matrix in the assembled state is defined as follows: In the compensated state, the compensated six-dimensional force / torque output is: ,Right now Here, Y refers to the original channel output of the six-dimensional force sensor when it is subjected to an external load. This represents the updated decoupling matrix, and Wc represents the six-dimensional force / torque output after assembly zero-point vector compensation and decoupling matrix correction when the six-dimensional force sensor is subjected to external load.

[0081] Decoupling matrix correction It can be determined based on the assembly response characteristics. The set of assembly response characteristics can be represented as: ,in, This represents the set of assembly response features used to determine the decoupling matrix correction. This indicates the tightening torque at each assembly stage. This indicates the temperature change after assembly relative to before assembly. This represents the normalized change in bridge impedance relative to the bridge impedance Z0 before assembly, after all screws have been tightened. It can be understood that the assembly response characteristic set can also include indices Q1-Q4, Q, and so on. , , - as well as At least one of them.

[0082] Decoupling matrix correction It can be determined based on the assembly response feature set through a pre-established mapping relationship; specifically, , where f represents the assembly response feature set With decoupling matrix correction The mapping relationship between them is the first mapping relationship.

[0083] The pre-established mapping relationship can be a mapping table containing a pre-established set of assembly response feature samples. Correction amount of the decoupling matrix corresponding to the assembly response feature set samples When the assembly response feature set When it is closest to the h-th sample, we can take: Where h satisfies .

[0084] In some embodiments, the decoupling matrix correction amount It can also be determined through regression models, specifically, Where B is the regression coefficient matrix and C is the constant correction matrix. B and C can be obtained through training using historical assembly samples, simplified loading verification samples, or installed state calibration samples. Here, simplified loading verification samples refer to samples obtained after assembly without performing a full six-dimensional full-range calibration, but only by applying several representative known forces or torques, such as zero point, unidirectional force, unidirectional torque, or several typical combined loads, to verify the output error after assembly and to train or correct ΔD. Installed state calibration samples refer to data samples collected under known loads, known attitudes, or standard working conditions after the sensor is installed on the robot, fixture, or actual equipment.

[0085] It is understandable that when assembly quality information is determined as the third piece of information representing assembly anomalies, i.e., when the assembly state is determined to be abnormal, no decoupling matrix correction amount will be generated. No zero-point compensation or matrix micro-correction is performed on the six-dimensional force output at this time. This is because continuing to use matrix micro-correction might mask situations such as localized pressure on the elastomer, abnormal flange contact, or abnormal conditions in sensitive bridge circuits, leading to uncontrollable errors in subsequent six-dimensional measurements. Therefore, in abnormal states, the electronic equipment only outputs an abnormality warning and is not allowed to treat abnormal assembly states as compensable states, to prevent serious assembly abnormalities from being simply zeroed out and reused.

[0086] Through the above compensation methods, this solution can complete assembly zero-point compensation when the assembly status is normal, complete assembly zero-point compensation and decoupling matrix micro-correction when the assembly status is slightly abnormal but acceptable, and prohibit erroneous compensation when the assembly status is abnormal, thereby improving the measurement consistency and reliability of the six-dimensional force sensor after installation.

[0087] The technical solution provided in this application, for each screw required for assembling a force sensor, acquires the decoupling output information and bridge impedance information of the force sensor after the screw is tightened to a set torque or set angle; based on the decoupling output information and bridge impedance information corresponding to screws tightened in adjacent assembly stages, determines the change in decoupling output and bridge impedance of each screw relative to the screw in the previous assembly stage; and based on at least one of the change in decoupling output and bridge impedance, determines assembly quality information characterizing whether there is an assembly abnormality. Thus, the solution of this application acquires the changes in the decoupling output and bridge impedance of the force sensor during the screw tightening process, which is used to determine the assembly quality and to promptly and accurately detect quality problems occurring during assembly, such as excessive local preload, abnormal contact surfaces, uneven diagonal preload, etc., thereby improving assembly efficiency.

[0088] The following section provides a more detailed description of this application with reference to application examples.

[0089] In this application example, a six-dimensional force sensor is mounted to the robot wrist flange using eight screws. Specifically, the factory reference parameters of the six-dimensional force sensor can be obtained, including the factory zero point b0, the factory decoupling matrix D0, and the factory bridge impedance Z. factory and factory temperature T factory Factory temperature T factory As a temperature reference for the factory zero point and factory bridge impedance, it can be used for subsequent temperature correction, to determine whether the pre-assembly temperature T0 differs too much from the factory temperature, or to adjust the factory bridge impedance Z. factory The factory zero point b0 is converted to the current assembly temperature conditions.

[0090] Before assembly, the sensor is in a no-load state, collecting the original channel output Y0, six-dimensional decoupled output W0, bridge impedance Z0, and temperature T0. During assembly, a cross-tightening sequence is used, for example, 1-5-3-7-2-6-4-8 (the numbers represent screw numbers). After each screw is tightened to the set torque, the corresponding assembly process data {screw number, tightening torque, Yk, Wk, Zk, Tk} is collected. The system calculates the decoupled output change ΔWk and bridge impedance change ΔZk for each assembly stage based on the assembly process data. If tightening a screw causes a significant abrupt change in Mx or My, and its bridge impedance change also exceeds the threshold, it is determined that there is excessive local pre-tightening or abnormal contact in the installation area corresponding to that screw. If the response characteristic difference between diagonal screws exceeds the threshold, it is determined that there is uneven diagonal pre-tightening, and the system will prompt the operator to back down the corresponding screw and retighten it in the cross-tightening sequence.

[0091] The system can also look up the corresponding screw number Sk based on the assembly stage k where a sudden change occurs, thereby locating the screw position that may introduce abnormal assembly prestress. When ΔWk increases significantly in stage k while ΔZk does not change significantly, the main cause is judged to be the elastic body being compressed or the flange contact state being abnormal; when both ΔWk and ΔZk change significantly, it is judged that the assembly action may have affected the sensitive components or the bridge circuit state; when the difference between ΔWp and ΔWq corresponding to the diagonal screws is large, it is judged that there is uneven diagonal preload or flange tilting.

[0092] After all screws are tightened, the system collects stable data after assembly. If the preload consistency index is less than the first threshold TH1, the assembly zero point bm is recorded, using the formula... Compensation is performed. If the preload consistency index Q is between the first threshold TH1 and the second threshold TH2, the assembly state is determined to be compensable. The system obtains the pre-established mapping relationship between the assembly response feature set and the decoupling matrix correction amount. Using formula Compensation is performed. When the preload consistency index Q ≥ the second threshold TH2, or the single-step mutation index Q2, symmetry index Q3, or impedance consistency index Q4 exceeds the corresponding safety threshold, the system determines that the assembly state has exceeded the reliable range of zero-point compensation or matrix micro-correction. If zero-point compensation is continued at this time, it may mask local pressure on the elastomer, abnormal flange contact, or abnormal bridge state of sensitive components, leading to uncontrollable errors in subsequent six-dimensional measurements. Therefore, the system prohibits the generation of matrix micro-correction quantities and outputs a prompt to reassemble or check the contact surface.

[0093] For six-dimensional force sensors that require repeated assembly and disassembly, the system saves the assembly response characteristics and compensation parameters (such as the latest zero-point vector and the corrected decoupling matrix) after each assembly, forming an assembly record. Upon reassembly, the system compares the current assembly response characteristics with historical qualified assembly records. If the deviation between the current assembly response characteristics and historical qualified records is small, the corresponding compensation parameters are allowed to be used; if the deviation is large, recalibration or reassembly is prompted. It can be understood that assembly fingerprints can be formed based on assembly process data, which can be used for consistency management of repeated assembly and disassembly, after-sales diagnostics, and assembly process optimization.

[0094] In the application example of this application, the assembly quality determination device for a force sensor may include a sensor acquisition module, an impedance acquisition module, an assembly information acquisition module, a temperature acquisition module, an assembly response feature extraction module, a preload consistency judgment module, a compensation parameter generation module, an output compensation module, and an assembly prompt module. Specifically, the sensor acquisition module acquires the raw channel output and the six-dimensional decoupled output of the force sensor; the impedance acquisition module acquires the resistance or impedance of each bridge circuit of the six-dimensional force sensor; the assembly information acquisition module acquires the screw number, screw tightening sequence, and screw tightening torque; the temperature acquisition module acquires the temperature of the six-dimensional force sensor or the assembly environment; the assembly response feature extraction module calculates the output change and impedance change at each assembly stage; the preload consistency judgment module calculates the preload consistency index and judges the assembly status; and the compensation parameter generation module generates the assembly zero-point compensation amount (i.e., the aforementioned assembly zero-point vector) and optional decoupling. The system includes: a matrix correction module; an output compensation module for outputting the compensated six-dimensional force and torque based on the compensation parameters; an assembly prompt module for providing prompts to adjust screws, retighten them, or check the contact surfaces when assembly is abnormal; an assembly record storage module for storing screw numbers, tightening sequence, tightening torque, assembly stage response vector, preload consistency index, assembly status, assembly zero-point compensation, and matrix correction for each assembly process; and a historical assembly comparison module for comparing the current assembly response characteristics with historical qualified assembly records to determine whether the current assembly status is consistent with the historical qualified status and outputting the consistency evaluation result for repeated disassembly and assembly.

[0095] Based on the above analysis, the proposed solution obtains assembly process data by comparing the differences between response vectors of adjacent stages or with the reference response vector before assembly. This data is used to determine whether each screw tightening action introduces abnormal assembly prestress. Furthermore, the system does not judge the consistency of preload solely based on torque values, but rather uses the correspondence between the screw assembly action input and the sensor response as the basis for judgment.

[0096] The highlights of this application are: Highlight 1: It not only records screw torque, but also correlates the screw tightening action with six-dimensional force output changes and bridge impedance changes.

[0097] Highlight 2: Utilizing changes in bridge impedance to help determine whether assembly preload affects sensitive components or the state of the bridge circuit.

[0098] Highlight 3: The consistency of assembly preload is judged by comprehensively considering indicators such as overall offset, single-step abrupt change, symmetry, and impedance consistency.

[0099] Highlight 4: The assembly status is divided into normal, compensable, and abnormal to avoid serious assembly abnormalities from being simply reset and continuing to use.

[0100] Highlight 5: When the assembly status is acceptable, not only can assembly zero-point compensation be performed, but also decoupling matrix micro-correction can be performed.

[0101] Highlight 6: Assembly process data can form assembly fingerprints, which can be used for consistency management of repeated disassembly and assembly, after-sales diagnosis, and assembly process optimization.

[0102] The advancements of this application in terms of structure, function, process, and cost are as follows: In terms of structure: Traditional solutions rely solely on mechanical assembly and post-installation zeroing, failing to detect assembly prestress. This invention introduces a correlation record of six-dimensional output, bridge impedance, and screw tightening information during the assembly process, forming a traceable assembly status.

[0103] In terms of functionality: traditional solutions can only reset to zero, while this invention can identify normal, compensable and abnormal assembly states, and can perform assembly zero-point compensation and matrix micro-correction.

[0104] In terms of process: Traditional assembly relies on manual experience, but this invention can determine whether abnormal assembly stress is introduced at each screw tightening stage, thus guiding the assembly process.

[0105] In terms of cost: Traditional complete six-dimensional calibration after installation is costly. This invention can complete assembly consistency testing and basic compensation without the need for complete calibration equipment, reducing on-site debugging costs.

[0106] Compared with related technologies, the differences of this application are at least as follows: 1. The zeroing method after installation only handles the final zero-point offset. This solution records the output and impedance changes at each screw tightening stage, which can identify the source of abnormalities in the assembly process.

[0107] 2. The torque control methods of related technologies only record the external tightening input. This solution further utilizes the original output, decoupled output and bridge impedance change of the six-dimensional force sensor to reflect the actual assembly effects on the elastomer and sensitive bridge.

[0108] 3. The method of directly using the factory matrix of related technologies does not take into account the pre-stress of the equipment. This solution generates the zero-point compensation amount of the assembly when the assembly state is acceptable, and can further generate the micro-correction amount of the decoupling matrix.

[0109] 4. The complete recalibration method of related technologies is costly and inefficient. This solution can complete the assembly status evaluation and basic compensation without performing a complete six-dimensional loading calibration.

[0110] 5. Related technologies often lack anomaly classification. This solution divides the assembly state into normal, compensable, and abnormal, and prohibits matrix correction in abnormal states to avoid serious assembly defects being simply masked by zeroing.

[0111] To implement the method of the embodiments of this application, the embodiments of this application also provide an assembly quality determination device for a force sensor. This device corresponds to the assembly quality determination method for the force sensor described above, and each step in the embodiment of the assembly quality determination method for the force sensor is also fully applicable to the embodiment of the assembly quality determination device for the force sensor.

[0112] like Figure 2 As shown, the assembly quality determination device for the force sensor includes: an acquisition module 201 (which performs the functions of the sensor acquisition module and impedance acquisition module as described in the above application example), an information processing module 202 (which performs the functions of the assembly response feature extraction module as described above), and an assembly quality determination module 203 (which performs the functions of the preload consistency judgment module as described above). The acquisition module 201 is used to acquire, for each screw required for assembling the force sensor, the decoupling output information and bridge impedance information of the force sensor after the screw is tightened to a set torque or a set angle; Information processing module 202 determines the change in decoupling output and bridge impedance of each screw relative to the screw in the previous assembly stage based on the decoupling output information and bridge impedance information corresponding to the screws tightened in adjacent assembly stages. Assembly quality determination module 203 is used to determine assembly quality information characterizing whether there is an assembly abnormality based on at least one of the decoupling output change and the bridge impedance change.

[0113] In some embodiments, the assembly quality information includes first information indicating normal assembly, second information indicating the need for additional compensation, and third information indicating abnormal assembly. The acquisition module 201 is also used to acquire the initial decoupling output information of the force sensor when no screws are assembled. The information processing module 202 is also used to determine the total decoupling output change based on the total decoupling output information of the force sensor after all the screws are assembled and the initial decoupling output information; The assembly quality determination module 203 is specifically used to: determine the assembly quality information based on at least one of the decoupling output change and the bridge impedance change, and the total decoupling output change.

[0114] In some embodiments, the assembly quality determination module 203 is specifically used for: A first score characterizing preload consistency is determined based on at least one of the normalized decoupling output change and the normalized bridge impedance change, as well as the normalized total decoupling output change. If it is determined that the first score is less than the first threshold, then the assembly quality information is determined to be the first information indicating that the assembly is normal. If it is determined that the first score is greater than or equal to the first threshold and less than the second threshold, then the assembly quality information is determined to be the second information indicating that additional compensation is required. If the first score is determined to be greater than or equal to the second threshold, then the assembly quality information is determined to be the third information indicating an assembly abnormality.

[0115] In some embodiments, the assembly quality determination module 203 is specifically used for: Based on the normalized total decoupling output change, a first index value characterizing the overall zero-point offset is determined. Based on the normalized decoupling output change, a second index value characterizing the degree of single-step zero-point offset is determined. Based on the decoupling output change corresponding to two screws in a symmetrical or diagonal assembly, a third index value characterizing the consistency of the symmetrical or diagonal screw assembly is determined. Based on the normalized change in bridge impedance, a fourth index value characterizing the change in bridge impedance is determined. The first score is determined based on at least one of the second, third, and fourth indicator values, the first indicator value, and the weights corresponding to each indicator value.

[0116] In some embodiments, the assembly quality determination module 203 is further configured to: If the value of the first indicator is determined to be greater than or equal to a preset first indicator threshold, the assembly quality information is determined as the third information indicating an assembly abnormality; or, If the value of the second indicator is determined to be greater than or equal to a preset second indicator threshold, the assembly quality information is determined as the third information indicating an assembly abnormality; or, If the value of the third indicator is determined to be greater than or equal to a preset third indicator threshold, the assembly quality information is determined to be the third information indicating an assembly abnormality; or, If the value of the fourth indicator is determined to be greater than or equal to the preset threshold value of the fourth indicator, the assembly quality information is determined to be the third information indicating an assembly abnormality.

[0117] In some embodiments, the apparatus further includes a compensation parameter generation module 204 and an output compensation module 205; The compensation parameter generation module 204 is used to determine the zero point vector based on the original channel output information of the force sensor after all the screws have been assembled and there is no external load, if the assembly quality information is determined to be either the first information indicating normal assembly or the second information indicating that additional compensation is required. The output compensation module 205 is used to determine the decoupling output information of the force sensor based on the zero-point vector, the original channel output information when the force sensor is subjected to external load, and the decoupling matrix when the force sensor is subjected to external load.

[0118] In some embodiments, the compensation parameter generation module 204 is further configured to: If the assembly quality information is determined to be the second type of information requiring additional compensation, then the decoupling matrix correction amount is determined based on the assembly response feature information and the first mapping relationship. The assembly response feature information includes at least one of the following: the normalized total decoupling output change, the normalized bridge impedance change, the tightening torque corresponding to each screw, the change in temperature value after all screws are assembled and before all screws are assembled, a first index value characterizing the overall zero-point offset, a second index value characterizing the single-step zero-point offset, a third index value characterizing the consistency of symmetrical or diagonal screw assembly, a fourth index value characterizing the bridge impedance change, and a first score characterizing the consistency of preload. The first mapping relationship includes the mapping relationship between the assembly response feature information and the decoupling matrix correction amount. Update the decoupling matrix based on the aforementioned decoupling matrix correction amount; The output compensation module 205 is further configured to: determine the decoupling output information of the force sensor based on the zero-point vector, the original channel output information when the force sensor is subjected to an external load, and the updated decoupling matrix when the force sensor is subjected to an external load.

[0119] It should be noted that the force sensor assembly quality determination device provided in the above embodiments is only illustrated by the division of the above-described program modules when determining the assembly quality of the force sensor. In practical applications, the above processing can be assigned to different program modules as needed, that is, the internal structure of the device can be divided into different program modules to complete all or part of the processing described above. In addition, the force sensor assembly quality determination device and the force sensor assembly quality determination method embodiment provided in the above embodiments belong to the same concept, and the specific implementation process is detailed in the method embodiment, which will not be repeated here.

[0120] Based on the hardware implementation of the above program modules, and in order to implement the method of the embodiments of this application, the embodiments of this application also provide an electronic device. Figure 3 The diagram shows only an exemplary structure of the electronic device, not the entire structure; implementation is possible as needed. Figure 3 The structure shown may be part or all of the structure.

[0121] like Figure 3 As shown, the electronic device 300 provided in this application embodiment includes at least one processor 301, a memory 302, and a user interface 303. The various components in the electronic device 300 are coupled together via a bus system 304. It can be understood that the bus system 304 is used to implement communication between these components. In addition to a data bus, the bus system 304 also includes a power bus, a control bus, and a status signal bus. However, for clarity, in… Figure 3 The general designated all buses as Bus System 304.

[0122] The user interface 303 may include a monitor, keyboard, mouse, trackball, click wheel, buttons, touchpad, or touch screen.

[0123] The memory 302 in this embodiment is used to store various types of data to support the operation of the electronic device 300. Examples of such data include any computer program used to operate on the electronic device 300.

[0124] The assembly quality determination method for a force sensor disclosed in this application can be applied to, or implemented by, a processor 301. The processor 301 may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the assembly quality determination method for the force sensor can be completed by integrated logic circuits in the hardware of the processor 301 or by instructions in software form. The processor 301 can be a general-purpose processor, a digital signal processor (DSP), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The processor 301 can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. A general-purpose processor can be a microprocessor or any conventional processor, etc. The steps of the method disclosed in the embodiments of this application can be directly manifested as execution by a hardware decoding processor, or execution by a combination of hardware and software modules in the decoding processor. The software modules can be located in a storage medium, specifically memory 302. The processor 301 reads information from memory 302 and, in conjunction with its hardware, completes the steps of the assembly quality determination method for the force sensor provided in the embodiments of this application.

[0125] In an exemplary embodiment, the electronic device 300 may be implemented by one or more application-specific integrated circuits (ASICs), DSPs, programmable logic devices (PLDs), complex programmable logic devices (CPLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers (MCUs), microprocessors, or other electronic components to perform the aforementioned method.

[0126] It is understood that memory 302 can be volatile memory or non-volatile memory, or both. Non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), ferromagnetic random access memory (FRAM), flash memory, magnetic surface memory, optical disc, or compact disc read-only memory (CD-ROM); magnetic surface memory can be disk storage or magnetic tape storage. Volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Synchronous Static Random Access Memory (SSRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (SDRAM), Double Data Rate Synchronous Dynamic Random Access Memory (DDRSDRAM), Enhanced Synchronous Dynamic Random Access Memory (ESDRAM), Sync Link Dynamic Random Access Memory (SLDRAM), and Direct Rambus Random Access Memory (DRRAM).The memories described in the embodiments of this application are intended to include, but are not limited to, these and any other suitable types of memories.

[0127] In an exemplary embodiment, this application also provides a storage medium, namely a computer storage medium, specifically a computer-readable storage medium, such as a memory 302 that stores a computer program. The computer program can be executed by the processor 301 of the electronic device 300 to complete the steps described in the method of this application embodiment. The computer-readable storage medium can be a ROM, PROM, EPROM, EEPROM, Flash Memory, magnetic surface memory, optical disc, or CD-ROM, etc.

[0128] In an exemplary embodiment, this application also provides a computer program product, including a computer program that can be executed by a processor 301 of an electronic device 300 to perform the steps described in the method of this application embodiment.

[0129] It should be noted that terms such as "first" and "second" are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. In this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0130] It should be understood that the phrase "some embodiments" throughout the specification means that a particular feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, "some embodiments" appearing throughout the specification does not necessarily refer to the same embodiment.

[0131] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0132] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" or "linked" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a connection that allows communication between the components; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0133] Furthermore, the technical solutions described in the embodiments of this application can be combined arbitrarily without conflict.

[0134] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A method for determining the assembly quality of a force sensor, characterized in that, The method includes: For each screw required to assemble the force sensor, obtain the decoupling output information and bridge impedance information of the force sensor after the screw is tightened to a set torque or a set angle; Based on the decoupling output information and bridge impedance information corresponding to the screws tightened in adjacent assembly stages, determine the decoupling output change and bridge impedance change of each screw relative to the screw in the previous assembly stage. Assembly quality information characterizing whether an assembly is abnormal is determined based on at least one of the decoupling output change and the bridge impedance change.

2. The method according to claim 1, characterized in that, The method further includes: Obtain the initial decoupling output information of the force sensor when the screws are not assembled; The total decoupling output change is determined based on the total decoupling output information of the force sensor after all the screws are assembled and the initial decoupling output information. The determination of assembly quality information characterizing whether an assembly anomaly exists based on at least one of the decoupling output change and the bridge impedance change includes: The assembly quality information is determined based on at least one of the decoupling output change and the bridge impedance change, as well as the total decoupling output change; the assembly quality information includes first information indicating normal assembly, second information indicating the need for additional compensation, and third information indicating assembly abnormality.

3. The method according to claim 2, characterized in that, Determining the assembly quality information based on at least one of the decoupling output change and the bridge impedance change, and the total decoupling output change, includes: A first score characterizing preload consistency is determined based on at least one of the normalized decoupling output change and the normalized bridge impedance change, as well as the normalized total decoupling output change. If it is determined that the first score is less than the first threshold, then the assembly quality information is determined to be the first information indicating that the assembly is normal. If it is determined that the first score is greater than or equal to the first threshold and less than the second threshold, then the assembly quality information is determined to be the second information indicating that additional compensation is required. If the first score is determined to be greater than or equal to the second threshold, then the assembly quality information is determined to be the third information indicating an assembly abnormality.

4. The method according to claim 3, characterized in that, The first score characterizing preload consistency is determined based on at least one of the normalized decoupling output change and the normalized bridge impedance change, and the normalized total decoupling output change, including: Based on the normalized total decoupling output change, a first index value characterizing the overall zero-point offset is determined. Based on the normalized decoupling output change, a second index value characterizing the degree of single-step zero-point offset is determined. Based on the decoupling output change corresponding to two screws in a symmetrical or diagonal assembly, a third index value characterizing the consistency of the symmetrical or diagonal screw assembly is determined. Based on the normalized change in bridge impedance, a fourth index value characterizing the change in bridge impedance is determined. The first score is determined based on at least one of the second, third, and fourth indicator values, the first indicator value, and the weights corresponding to each indicator value.

5. The method according to claim 4, characterized in that, The method of determining the assembly quality information based on at least one of the decoupling output change and the bridge impedance change, and the total decoupling output change, further includes: If the value of the first indicator is determined to be greater than or equal to a preset first indicator threshold, the assembly quality information is determined as the third information indicating an assembly abnormality; or, If the value of the second indicator is determined to be greater than or equal to a preset second indicator threshold, the assembly quality information is determined as the third information indicating an assembly abnormality; or, If the value of the third indicator is determined to be greater than or equal to a preset third indicator threshold, the assembly quality information is determined to be the third information indicating an assembly abnormality; or, If the value of the fourth indicator is determined to be greater than or equal to the preset threshold value of the fourth indicator, the assembly quality information is determined to be the third information indicating an assembly abnormality.

6. The method according to claim 2, characterized in that, The method further includes: If the assembly quality information is determined to be either the first information indicating normal assembly or the second information indicating the need for additional compensation, then the zero-point vector is determined based on the original channel output information of the force sensor after all the screws have been assembled and there is no external load. When the force sensor is subjected to an external load, the decoupling output information of the force sensor is determined based on the zero-point vector, the original channel output information under external load, and the decoupling matrix.

7. The method according to claim 6, characterized in that, The method further includes: If the assembly quality information is determined to be the second type of information requiring additional compensation, then the decoupling matrix correction amount is determined based on the assembly response feature information and the first mapping relationship. The assembly response feature information includes at least one of the following: the normalized total decoupling output change, the normalized bridge impedance change, the tightening torque corresponding to each screw, the change in temperature value after all screws are assembled and before all screws are assembled, a first index value characterizing the overall zero-point offset, a second index value characterizing the single-step zero-point offset, a third index value characterizing the consistency of symmetrical or diagonal screw assembly, a fourth index value characterizing the bridge impedance change, and a first score characterizing the consistency of preload. The first mapping relationship includes the mapping relationship between the assembly response feature information and the decoupling matrix correction amount. Update the decoupling matrix based on the aforementioned decoupling matrix correction amount; When the force sensor is subjected to an external load, the decoupling output information of the force sensor is determined based on the zero-point vector, the original channel output information under external load, and the updated decoupling matrix.

8. A device for determining the assembly quality of a force sensor, characterized in that, The device includes: The acquisition module is used to acquire, for each screw required for assembling the force sensor, the decoupling output information and bridge impedance information of the force sensor after the screw is tightened to a set torque or a set angle; The information processing module determines the change in decoupling output and the change in bridge impedance for each screw relative to the screw in the previous assembly stage, based on the decoupling output information and the bridge impedance information corresponding to the screws tightened in adjacent assembly stages. An assembly quality determination module is used to determine assembly quality information characterizing whether an assembly is abnormal based on at least one of the decoupling output change and the bridge impedance change.

9. An electronic device, characterized in that, The electronic device includes a processor and a memory for storing a computer program capable of running on the processor, wherein the processor, when running the computer program, performs the steps of the method according to any one of claims 1 to 7.

10. A storage medium storing a computer program, characterized in that, When the computer program is executed by the control device, it implements the steps of the method according to any one of claims 1 to 7.

11. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the controlled device, it implements the steps of the method according to any one of claims 1 to 7.

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