Aircraft flap component robot compliant assembly control method and system

Abstract

The invention provides an aircraft flap component robot compliant assembly control method and system, and relates to the technical field of compliant assembly control. According to the method, a flap part compliant assembly system is established through a force sensor and a mobile industrial robot, a compliant assembly and adjustment method integrating man-machine cooperation and robot compliant control is innovated, the zero drift and temperature drift of the force sensor and the gravity and gravity center of a tail end load are identified, and the accuracy of external force information sensing of the system is guaranteed; a high-flexibility compliant control mechanism with free matching of multiple modes such as single shaft, multi-shaft linkage, stepping and continuous adjustment is designed, jitter and non-jitter intervals are fitted according to a system force control coefficient jitter distribution test, and a theoretical assembly model based on a flap sample piece assembly track and assembly force information is provided. And the aircraft flap flexible assembly based on the expected trajectory is realized. The invention provides a solution for the flexible assembly of the flap part of the large aircraft, and has the characteristics of intelligence, good flexibility, strong adaptability and the like.

Description

Technical Field

[0001] The invention relates to the technical field of flexible assembly control, and in particular to a robot flexible assembly control method and system for aircraft flap components. Background Art

[0002] Aircraft flap components are characterized by small batches, large sizes, and heavy loads. The quality of their assembly with the wings and fuselage directly affects the lift or drag of the aircraft during takeoff and landing. Due to their unique structural and functional characteristics, the assembly process of aircraft flaps presents multi-point or continuous trajectory constraints, and the high assembly precision greatly increases the difficulty of flap assembly. In addition, during the actual aircraft assembly and assembly process, the positions of the fuselage and flaps are not fixed when assembling different batches of aircraft, resulting in long assembly equipment scheduling and assembly time, which seriously affects the progress of aircraft assembly. Therefore, a high-flexibility and high-efficiency robot compliant assembly method and equipment suitable for aircraft flaps is needed.

[0003] At present, during the aircraft assembly process, the assembly of flaps mostly adopts a lifting method that combines tooling and hoisting equipment. This method requires a lot of manpower for assembly, has low efficiency, and has low coordination and stability among multiple people. It is also prone to collisions during assembly. The existing lifting assembly method cannot achieve assembly speed control, and the efficiency of large-scale movement and local movement depends entirely on the operator. In addition, the alignment adjustment amount is uncontrollable during precise assembly, which places high demands on the operator's assembly technology and coordination level. In addition, the lifting assembly method requires an open space at the assembly site and no obstructions above the assembly object, which limits the scenarios in which it can be used. Summary of the invention

[0004] Purpose of the invention: To propose a robot compliant assembly control method for aircraft flap components, and further propose a robot compliant assembly system for aircraft flap components that can execute the control method, so as to solve the above-mentioned problems existing in the prior art.

[0005] A first aspect of the present invention provides a robot compliant assembly system for aircraft flap components, the assembly system comprising a product bracket, an assembly object, an AGV automatic guided vehicle, an industrial robot, an end fixture, and a six-dimensional force sensor.

[0006] The product bracket is arranged at a predetermined position in a predetermined working space; an aircraft flap and an aircraft flap sample are placed on the product bracket.

[0007] The assembly object is set at a predetermined position in a predetermined workspace.

[0008] The AGV automatic guided vehicle moves within a predetermined workspace.

[0009] The industrial robot is arranged on the AGV automatic guided vehicle; the end fixture of the industrial robot clamps the aircraft flap sample; the industrial robot can reach the product bracket and the assembly object under the movement of the AGV automatic guided vehicle.

[0010] The six-dimensional force sensor is installed between the flange and the end fixture of the industrial robot, and can sense external force information from the end fixture, aircraft flap, and aircraft flap sample.

[0011] Based on the robot compliant assembly system for aircraft flap components proposed in the first aspect, the second aspect of the present invention provides a robot compliant assembly control method for aircraft flap components, the steps of which are as follows:

[0012] Step 1: Move the AGV to the aircraft flap assembly station and make sure that the position of the product bracket with the aircraft flap and the aircraft flap sample is in line with the assembly space;

[0013] Step 2: Determine the state of the end fixture of the industrial robot, establish the robot base coordinate system {B}, flange coordinate system {F}, and force sensor coordinate system {S}, adjust the posture of the industrial robot, collect multiple sets of robot posture information in a stable state and its corresponding end force sensor information, and calculate the end fixture gravity, center of gravity, and force sensor zero drift and temperature drift values;

[0014] Step 3: Perform gravity compensation for different postures of the industrial robot during movement according to the calculated end fixture gravity, center of gravity, and zero drift and temperature drift values ​​of the force sensor;

[0015] Step 4: The operator drags the end fixture to the vicinity of the product bracket;

[0016] Step 5: The end fixture clamps the aircraft flap sample from the product bracket;

[0017] Step 6: The six-dimensional force sensor collects the gravity and center of gravity of the currently clamped aircraft flap sample to determine whether the current clamping environment meets the process requirements. If not, the clamping position is readjusted until the process requirements are met.

[0018] Step 7: When the distance between the end of the industrial robot and the assembly object is greater than or equal to the safety distance, the rapid force control mode is adjusted to control the industrial robot to the flap pre-assembly space position at the speed in the rapid force control mode;

[0019] Step 8: When the distance between the end of the industrial robot and the assembly object is less than the safety distance, adjust to the slow force control mode;

[0020] Step 9: The operator drags the aircraft flap sample close to the assembly position at a speed in the slow force control mode;

[0021] Step 10: Set the force control trigger upper and lower thresholds of the aircraft flap component robot compliant assembly system [F B , F T ];

[0022] Step 11: When the force control triggers the upper and lower thresholds [F B , F T ], assemble the aircraft flap sample to the predetermined position, complete the assembly of the flap sample, and record the motion trajectory L1 and the force information after gravity compensation of the force sensor;

[0023] Step 12: When the force control triggers the upper and lower thresholds [F B , F T ], the aircraft flap sample is moved from the predetermined assembly position to the assembly position, and the force information during the moving process and the robot's motion trajectory L2 are recorded;

[0024] Step 13: Assemble the theoretical trajectory L of the aircraft flap E As the goal, the motion trajectories L1 and L2 in the assembly process are fitted and optimized to obtain the expected motion trajectory of the robot in the compliant assembly process at the current spatial position. ;

[0025] Step 14, the AGV moves to the aircraft flap sample storage rack, releases the end clamp, puts the aircraft flap sample back into the product bracket, clamps the aircraft flap at the same time, repeats steps 4 to 9, and moves the aircraft flap to the pre-assembly position;

[0026] Step 15: The robot compliant assembly system of the aircraft flap parts follows the expected motion trajectory , start compliant assembly control based on the desired motion trajectory;

[0027] Step 16: After the assembly is completed according to step 15, stop the automatic assembly, release the end clamp, return to the initial position, and complete the aircraft flap assembly.

[0028] In a further embodiment of the second aspect, in step 2, the origin of the robot base coordinate system {B} is located at the center of the base; the origin of the flange coordinate system {F} is located at the center of the flange; the origin of the force sensor coordinate system {S} is located at the center of the force sensor;

[0029] The design force sensor coordinate system {S} is aligned with the flange coordinate system {F}, with only a translation in the z direction, and the x, y, and z directions of the end force sensor information are aligned with the x direction of the force sensor coordinate system {S}. S ,y S 、z S Overlap respectively.

[0030] In a further embodiment of the second aspect, the relationship between the data collected by the six-dimensional force sensor and the weight of the hung load is:

[0031]

[0032] In the formula, G x , G y , G z 、T Gx 、T Gy and T Gz F is the component force and moment of the load gravity in the x, y, and z directions in the force sensor coordinate system {S}; x 、F y 、F z 、T x 、T y and T z are the six-dimensional force information collected by the force sensor; F x0 、F y0 、F z0 、T x0 、T y0 、T z0 is the zero drift value and temperature drift value of the force sensor;

[0033] Six-axis force sensor temperature drift value and ambient temperature C t The relationship between them is F x0 (C t ), F y0 (C t ), F z0 (C t ), T x0 (C t ), T y0 (C t ), T z0 (C t ), then the zero drift value of the six-axis force sensor satisfies:

[0034]

[0035] In the formula, , , , , , They are the zero drift values ​​of the force in the three directions of x, y, and z and the torque in the directions of rotation around the three axes of the six-dimensional force sensor;

[0036] Load gravity, moment and position of load center of gravity in force sensor coordinate system {S} (x g , y g , z g ) satisfy:

[0037] .

[0038] In a further embodiment of the second aspect, in step 7 and step 8, variable admittance control is used to switch between the fast force control mode and the slow force control mode;

[0039] The parameter change range of variable admittance control is the experimental calibration result, in which the virtual stiffness coefficient is zero, the virtual mass and virtual damping parameters are adjusted, the admittance parameter values ​​of the critical states of no jitter and jitter are recorded, the system state is divided into a jitter interval and a no jitter interval, and the system force-controlled drag speed adjustment interval is set in the no jitter interval.

[0040] In a further embodiment of the second aspect, in step 7 and step 8, the operator's intention is always identified:

[0041] When the output acceleration of the admittance model is not 0, and the direction of acceleration is the same as the direction of velocity, acceleration occurs;

[0042] When the output acceleration and velocity are both 0, or the external force is 0, it stops;

[0043] In other cases, when the external force is not 0, the operation intention is to decelerate;

[0044] This process is expressed as follows:

[0045]

[0046] Where, F is the external force after gravity compensation; and They are the speed and acceleration in the i-axis direction respectively, i is the translation and rotational degrees of freedom in the x, y, and z directions of the robot end, and the acceleration and deceleration of each axis run separately.

[0047] In a further embodiment of the second aspect, in step 9, the single force-controlled end adjustment amount is set according to the adjustment distance, and the single-step adjustment amount change range of the translation axis is [0.005mm, 1mm], and the single-step adjustment amount change range of the rotation axis is [0.001°, 0.1°].

[0048] In a further embodiment of the second aspect, in step 10, the force control trigger upper and lower thresholds [F B , F T ], including:

[0049] The slide rail connection part of the aircraft flap sample is equipped with a floating structure, and the range of its compression or tension force is [F S1 , F S2 ];

[0050] Force control trigger lower threshold F B Determined by the minimum compression force of the floating mechanism; the upper threshold F of the force control trigger T Determined by the maximum compression or tension force of the floating mechanism;

[0051] The implementation logic is as follows:

[0052]

[0053] In the formula, is the external force on the i-th axis after gravity compensation; i is the translation and rotational freedom of the robot end in the x, y, and z directions.

[0054] In a further embodiment of the second aspect, in step 13, the motion trajectories L1 and L2 are motion trajectory information in the robot base coordinate system {B}, L E is a theoretical trajectory of an uncertain position in space. During the fitting process, the trajectory L E Defined in the robot base coordinate system {B}, the assembly trajectory with the smallest difference from the two trajectories L1 and L2 is obtained :

[0055] .

[0056] The third aspect of the present invention provides an electronic device, which includes a processor, a memory, a communication interface and a communication bus. The processor, the memory and the communication interface communicate with each other through the communication bus; the memory is used to store a plurality of executable instructions, and the executable instructions enable the processor to execute the robot compliant assembly control method of the aircraft flap component as described in the second aspect.

[0057] A fourth aspect of the present invention provides a computer-readable storage medium storing a plurality of executable instructions. When the executable instructions are executed on an electronic device, the electronic device executes the aircraft flap component robot compliant assembly control method as described in the second aspect.

[0058] Beneficial effects:

[0059] 1) The present invention proposes a robot flexible assembly system for aircraft flap components and an operation method thereof. Through AGV, robots, force sensors, special end fixtures, and flap samples, the flexible assembly of aircraft flaps with continuous motion trajectories is realized. The method is highly flexible and adaptable. Through end quick change, AGV movement, and database establishment, the flexible assembly of aircraft flaps of different specifications, different batches, and different spatial positions can be realized.

[0060] 2) In order to accurately sense the external forces exerted on the aircraft flaps during the assembly process, the present invention takes into account the influence of the end fixture, aircraft flaps, force sensor zero drift and temperature drift, and proposes corresponding identification and compensation methods, so that the system can sense the external forces during the assembly process under different environments. Combined with the force-controlled compliant assembly method, the robot system can sense the assembly force and adjust the robot posture accordingly, avoiding excessive force on the aircraft flap assembly and damage to the system and product.

[0061] 3) The present invention proposes a variable admittance control method including step control and variable speed force control, which can realize large-range rapid movement and small-range slow movement of a single axis or multiple axes of the robot compliant assembly system according to human operation intentions. At the same time, step control can be performed during local precise attitude adjustment, and the size of a single step distance is controllable, which improves the system's operating efficiency, operability and adaptability, and meets the precision requirements of different processes in the aircraft flap assembly process.

[0062] 4) The present invention adopts an aircraft flap sample pre-assembly method with a floating mechanism, collects the trajectory information and force information of the aircraft flap assembly, and obtains the assembly motion trajectory of the aircraft flap during the actual assembly process by fitting with the theoretical assembly trajectory. Combined with the force-controlled compliant assembly method based on the expected trajectory, the automatic compliant assembly of aircraft flap components with continuous trajectory constraints is realized, providing a high-flexibility solution for the assembly of aircraft flap components. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 It is a composition diagram of the compliant assembly system of the aircraft flap components in the embodiment.

[0064] Figure 2 This is a control flow chart of the robot compliant assembly of aircraft flap components in an embodiment.

[0065] Figure 3 1 is a coordinate system relationship diagram of the robot compliant assembly system in the embodiment.

[0066] Figure 4 This is a diagram of the division of the system force-controlled jitter interval and the selection of the variable admittance parameter interval in the embodiment.

[0067] The reference numerals in the figure are: AGV automatic guided vehicle 1, robot control cabinet 2, terminal electrical control cabinet 3, industrial robot 4, product bracket 5, six-dimensional force sensor 6, aircraft flap 7, terminal fixture 8, assembly object 9, aircraft flap sample 10, obstacle avoidance radar 11. DETAILED DESCRIPTION

[0068] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present invention. However, it is apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features known in the art are not described.

[0069] The following embodiments disclose a robot compliant assembly control method and system for aircraft flap components, which are used for inner flap assembly during aircraft wing assembly to achieve highly flexible, efficient, highly integrated and easy-to-operate aircraft flap 7 assembly, providing technical support for improving aircraft assembly efficiency.

[0070] Figure 1 The structure of the robot compliant assembly system for aircraft flap parts is displayed. The assembly system includes the following hardware: AGV automatic guided vehicle 1, industrial robot 4, six-dimensional force sensor 6, end fixture 8, obstacle avoidance radar 11, aircraft flap sample 10, product bracket 5. The robot's operating range can reach the product bracket 5 and the assembly object 9. The six-dimensional force sensor 6 is located between the robot flange and the end fixture 8, and can sense the external force information of the end fixture 8, aircraft flap 7 and aircraft flap sample 10. The automatic guided vehicle is equipped with a robot control cabinet 2 and a terminal electrical control cabinet 3, which can achieve a large range of movement and has a four-legged support anti-overturning function. The six-dimensional force sensor 6 and the robot's rated load meet the weight of the end fixture 8. The product bracket 5 can hold the aircraft flap 7 and the aircraft flap sample 10 at the same time.

[0071] Figure 2 The control flow of the assembly system is shown. The specific steps are as follows:

[0072] Step 1. According to the actual needs of the aircraft assembly site, mobilize the AGV automatic guided vehicle 1 equipped with the robot flexible assembly system to the aircraft flap 7 assembly station, move the bracket with the aircraft flap 7 to be assembled and the aircraft flap sample 10 to the corresponding assembly work position, ensure that the spatial position relationship between the robot, the bracket, and the assembly object 9 is in line with the robot's working range, and unfold the four-leg support of the AGV automatic guided vehicle 1 to improve the stability of the entire system.

[0073] Step 2: Determine the state of the robot end fixture 8, such as Figure 3 As shown, the robot base coordinate system {B}, flange coordinate system {F}, and force sensor coordinate system {S} are established, the robot posture is adjusted, multiple sets of robot posture information in a stable state and its corresponding end force sensor information are collected, and the gravity, center of gravity, and zero drift and temperature drift values ​​of the end fixture 8 are calculated.

[0074] Among them, the origin of the robot base coordinate system is located at the center of the base, the origin of the flange coordinate system is located at the center of the flange, and the origin of the force sensor coordinate system is located at the center of the force sensor. The force sensor coordinate system is designed to coincide with the flange coordinate system, with only a translation in the z direction, and the x, y, and z directions of the force information coincide with the x of the force sensor coordinate system. S ,y S 、z S Overlap respectively.

[0075] Furthermore, the relationship between the data collected by the force sensor and the weight of the load is:

[0076]

[0077] In the formula, G x , G y , G z 、T Gx 、T Gy and T Gz is the component force and moment of the load gravity in the x, y and z directions of the {S} coordinate system, F x 、F y 、F z 、T x 、T y and T z are the six-dimensional force information collected by the force sensor, F x0 、F y0 、F z0 、T x0 、T y0 、T z0 The zero drift and temperature drift of the force sensor. t The relationship between them is F x0 (C t ), F y0 (C t ), F z0 (C t ), T x0 (C t ), T y0 (C t ), T z0 (C t ), then the zero drift value of the sensor satisfies:

[0078]

[0079] Furthermore, the load gravity, moment and the position of the load center of gravity in the coordinate system {S} (x g , y g , z g ) satisfy:

[0080]

[0081] Substituting equation (1) into equation (3), we can simplify it to obtain:

[0082]

[0083] In the formula

[0084]

[0085] Collect more than three sets of robot posture information and corresponding force sensor information, and record the stability of the environment. Substitute it into formula (4) to obtain the center of gravity of the load (x g , y g , z g ) and (r1, r2, r3), and further substitute them into equation (5) and equation (2) to obtain the zero drift and temperature drift values ​​of the sensor.

[0086] Step 3: Perform gravity compensation for different postures of the robot during movement according to the identified gravity, center of gravity and sensor zero drift value, and make sure that the force information collected by the force sensor after compensation meets the requirements of force-controlled compliant assembly. Otherwise, increase the coverage range and number of robot gravity and center of gravity identification postures until the gravity compensation requirements are met.

[0087] Step 4: Turn on the human-machine collaborative force control function of the robot's flexible assembly system, and the operator drags the end fixture 8 to the vicinity of the aircraft flap 7 and the aircraft flap sample 10 bracket.

[0088] During this process, the robot's posture and force sensor information are collected in real time. To ensure the validity of the force sensor information and avoid transient changes in the system state caused by external interference and accidental collisions, the force sensor sampling frequency is set greater than 1KHz, and the collected information is subjected to sliding mean filtering before gravity compensation calculation to avoid waste of computing efficiency. The robot's posture adjustment information under the corresponding state is further calculated in combination with the admittance control, and the robot is periodically moved according to the adjustment information.

[0089] Further, according to the above operation, the end clamp 8 is dragged to the clamping position of the aircraft flap sample 10.

[0090] Step 5: Turn off the human-machine collaborative force control function of the system, turn on the clamping function of the end fixture 8, and complete the clamping of the aircraft flap sample 10.

[0091] Step 6. Repeat step 2 to complete the identification of the end gravity and center of gravity in the clamping state, and compare the identification results with the theoretical data, and determine whether the clamping posture and compensation results of the aircraft flap sample 10 meet the process requirements. If not, readjust the clamping position until the gravity compensation requirements are met.

[0092] Step 7: Adjust the spatial position of the robot end to a position suitable for the worker to drag, turn on the system's flexible control, manually determine the distance between the robot end and the assembly object 9, adjust to a fast force-controlled dragging speed, and quickly control the robot to the flap pre-assembly spatial position.

[0093] Furthermore, the variable admittance control is used to adjust the force-controlled dragging speed in step 7, and its parameter variation range is the experimental calibration result, in which the virtual stiffness coefficient is zero, the virtual mass and virtual damping parameters are adjusted, and the admittance parameter values ​​of the non-jitter and jitter critical states are recorded, and the system state is divided into the jitter interval and the non-jitter interval, such as Figure 4 As shown, the system force-controlled drag speed adjustment range is set to be within the jitter-free range.

[0094] Collect the external force when the robot force control shakes and the robot displacement, velocity, and acceleration output by the admittance control model, determine the maximum position, velocity, and acceleration of the robot when it shakes, select the sine function adjustment as the external force, calculate the displacement, velocity, and acceleration of the robot under different admittance parameters, determine whether the robot is shaking, and determine all the admittance coefficient change ranges that meet the no-shake state.

[0095] Step 8: When it is manually determined that the distance between the aircraft flap sample 10 and the assembly object 9 is small, or when the laser radar triggers the set safety distance, the robot's compliant assembly system is adjusted to the slow force control mode.

[0096] Furthermore, in step 7 and step 8, in order to facilitate the operator to start and stop the system, the operator's intention is always identified, which can be expressed as:

[0097] When the output acceleration of the admittance model is not 0, and the direction of acceleration is the same as the direction of velocity, acceleration occurs;

[0098] When the output acceleration and velocity are both 0, or the external force is 0, it stops;

[0099] In other cases, when the external force is not 0, the operation intention is to decelerate.

[0100] Right now:

[0101]

[0102] Where, F is the external force after gravity compensation; and They are the speed and acceleration in the i-axis direction respectively, i is the translation and rotational degrees of freedom in the x, y, and z directions of the robot end, and the acceleration and deceleration of each axis run separately.

[0103] Step 9, slowly drag the aircraft flap sample 10 close to the assembly position, and focus on adjusting the slide rail of the aircraft flap sample 10 to meet the assembly requirements, requiring the end faces of the slide rail and the assembly track to coincide and the center lines to be coaxial.

[0104] Furthermore, in order to satisfy the pre-assembly requirements of the spatial posture of the aircraft flap sample 10, the force control function of the selectable axis is turned on according to the posture adjustment requirements, which can set a certain axis or several axes to start force control, while the remaining axes remain unchanged.

[0105] In addition, by turning on the step adjustment function of the robot's compliant control system, the single force control end adjustment amount can be set according to the adjustment distance. The single-step adjustment amount range of the translation axis is [0.005mm, 1mm], and the single-step adjustment amount range of the rotation axis is [0.001°, 0.1°]. In addition, independent movement of one or several axes can still be achieved.

[0106] Step 10: Set the upper and lower thresholds of the system force control trigger [F B , F T ], so that the system end can adjust its posture online when the force is within the upper and lower thresholds, further realizing the dragging and smooth assembly of the aircraft flap sample 10.

[0107] The aircraft flap sample 10 slide rail connection part is provided with a floating structure, and the variation range of its compression or tension force is [F S1 , F S2 ], which can avoid the aircraft flap 7 and the assembly object 9 from being damaged by the large resistance during the assembly process. Furthermore, the lower threshold F of the force control trigger B Determined by the minimum compression force of the floating mechanism, when the floating mechanism receives compression or tension force, the assembly system can be adjusted according to the direction of the force; the upper threshold F of the force control trigger T It is determined by the maximum compression or tension of the floating mechanism to prevent the floating mechanism from being damaged when it is subjected to excessive force. The implementation logic is as follows:

[0108]

[0109] In the formula, is the external force on the i-th axis after gravity compensation; i is the translation and rotational freedom of the robot end in the x, y, and z directions, which can realize force control operation in each direction within the allowable force control range.

[0110] Step 11, assemble the aircraft flap sample 10 to the predetermined position in the manner of step 10 to complete the assembly of the flap sample, and record the robot motion trajectory L1 of this process and the force information of the force sensor after gravity compensation.

[0111] Step 12: Use the same force-controlled assembly method as in step 10 to move the aircraft flap sample 10 from the predetermined assembly position to the assembly position, and record the force information during the removal process and the robot's motion trajectory L2.

[0112] Step 13: Assemble the theoretical trajectory L with the aircraft flap 7 E As the goal, the motion trajectories L1 and L2 in the assembly process are fitted and optimized to obtain the expected motion trajectory of the robot in the compliant assembly process at the current spatial position. .

[0113] Where L1 and L2 are the motion trajectory information of the robot base coordinate system {B}, L E is a theoretical trajectory of an uncertain position in space. During the fitting process, the trajectory L E Defined in the robot base coordinate system {B}, the assembly trajectory with the smallest difference from the two trajectories L1 and L2 is obtained .

[0114]

[0115] in:

[0116]

[0117] Where T is the theoretical assembly trajectory L E And the fitted assembly trajectory The transformation relationship between them includes the rotation matrix R and the translation matrix M.

[0118] Step 14, move the robot flexible assembly system to the storage rack of the aircraft flap sample 10, stop force control and release the clamp to complete the placement of the aircraft flap sample 10, and at the same time move the robot flexible system to clamp the aircraft flap 7 according to the moving position, and repeat steps 4 to 9 to move the aircraft flap 7 components to the pre-assembly position.

[0119] Step 15: Robot compliant assembly system For the desired motion trajectory, turn on the compliant assembly control based on the desired motion trajectory.

[0120] Furthermore, this process does not require human intervention. The robot assembly system automatically performs assembly, and while moving along a predetermined trajectory, force control is turned on, allowing the robot to adapt to changes in assembly force caused by flap clamping errors and trajectory fitting errors.

[0121] The force information collected in step 10 and step 11 is processed simultaneously, and the force information of the vertical predetermined trajectory is extracted, and the average is taken and set as the force control lower threshold value in this direction in step 15. That is, since the track in this direction is in real-time contact with the assembly, force is allowed in this direction.

[0122] Step 16: After the assembly is completed in step 15, the automatic assembly is stopped and the force control is turned off. The robot gripper is released and returns to the initial position, thus completing the assembly of the aircraft flap 7.

[0123] In practical applications, the operation logic of the control method disclosed in the above embodiment can be written into a set of executable instructions, which are written into a storage medium and run on an electronic device. More specific examples of the computer-readable storage medium mentioned in this embodiment may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. The computer-readable storage medium may include a data signal propagated in a baseband or as part of a carrier wave, wherein a readable program code is carried. This propagated data signal may take a variety of forms, including but not limited to an electromagnetic signal, an optical signal, or any suitable combination of the above. The readable signal medium may also be any readable medium other than a readable storage medium, which may send, propagate, or transmit a program used by or in combination with an instruction execution system, an apparatus, or a device.

[0124] As described above, although the present invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the present invention itself. Various changes may be made to it in form and detail without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims

1. A robot compliant assembly control method for aircraft flap components, characterized in that: The steps include: Step 1: Move the AGV to the aircraft flap assembly station and make sure that the position of the product bracket with the aircraft flap and the aircraft flap sample is in line with the assembly space; Step 2: Determine the state of the end fixture of the industrial robot, establish the robot base coordinate system {B}, flange coordinate system {F}, and force sensor coordinate system {S}, adjust the posture of the industrial robot, collect multiple sets of robot posture information in a stable state and its corresponding end force sensor information, and calculate the end fixture gravity, center of gravity, and force sensor zero drift and temperature drift values; Step 3: Perform gravity compensation for different postures of the industrial robot during movement according to the calculated end fixture gravity, center of gravity, and zero drift and temperature drift values ​​of the force sensor; Step 4: The operator drags the end fixture to the vicinity of the product bracket; Step 5: The end fixture clamps the aircraft flap sample from the product bracket; Step 6: The six-dimensional force sensor collects the gravity and center of gravity of the currently clamped aircraft flap sample to determine whether the current clamping environment meets the process requirements. If not, the clamping position is readjusted until the process requirements are met. Step 7: When the distance between the end of the industrial robot and the assembly object is greater than or equal to the safety distance, the rapid force control mode is adjusted to control the industrial robot to the flap pre-assembly space position at the speed in the rapid force control mode; Step 8: When the distance between the end of the industrial robot and the assembly object is less than the safety distance, adjust to the slow force control mode; Step 9: The operator drags the aircraft flap sample close to the assembly position at a speed in the slow force control mode; Step 10: Set the force control trigger upper and lower thresholds of the aircraft flap component robot compliant assembly system [F B , F T ]; Step 11: When the force control triggers the upper and lower thresholds [F B , F T ], assemble the aircraft flap sample to the predetermined position, complete the assembly of the flap sample, and record the motion trajectory L1 and the force information after gravity compensation of the force sensor; Step 12: When the force control triggers the upper and lower thresholds [F B , F T ], the aircraft flap sample is moved from the predetermined assembly position to the assembly position, and the force information during the moving process and the robot's motion trajectory L2 are recorded; Step 13: Assemble the theoretical trajectory L of the aircraft flap E As the goal, the motion trajectories L1 and L2 in the assembly process are fitted and optimized to obtain the expected motion trajectory of the robot in the compliant assembly process at the current spatial position. ; Step 14, the AGV moves to the aircraft flap sample storage rack, releases the end clamp, puts the aircraft flap sample back into the product bracket, clamps the aircraft flap at the same time, repeats steps 4 to 9, and moves the aircraft flap to the pre-assembly position; Step 15: The robot compliant assembly system of the aircraft flap parts follows the expected motion trajectory , start compliant assembly control based on the desired motion trajectory; Step 16: After the assembly is completed according to step 15, stop the automatic assembly, release the end clamp, return to the initial position, and complete the aircraft flap assembly.

2. The robot compliant assembly control method for aircraft flap components according to claim 1, characterized in that: In step 2, the origin of the robot base coordinate system {B} is located at the center of the base; the origin of the flange coordinate system {F} is located at the center of the flange; the origin of the force sensor coordinate system {S} is located at the center of the force sensor; The design force sensor coordinate system {S} is aligned with the flange coordinate system {F}, with only a translation in the z direction, and the x, y, and z directions of the end force sensor information are aligned with the x direction of the force sensor coordinate system {S}. S ,y S 、z S Overlap respectively.

3. The robot compliant assembly control method for aircraft flap components according to claim 2, characterized in that: The relationship between the data collected by the six-dimensional force sensor and the weight of the load is: ； In the formula, G x , G y , G z , T Gx , T Gy and T Gz F is the component force and moment of the load gravity in the x, y, and z directions in the force sensor coordinate system {S}; x 、F y 、F z , T x , T y and T z They are the six-dimensional force information collected by the force sensor; F x0 、F y0 、F z0 , T x0 , T y0 , T z0 is the zero drift value and temperature drift value of the force sensor; Six-axis force sensor temperature drift value and ambient temperature C t The relationship between them is F x0 (C t ), F y0 (C t ), F z0 (C t ), T x0 (C t ), T y0 (C t ), T z0 (C t ), then the zero drift value of the six-axis force sensor satisfies: ； In the formula, , , , , , They are the zero drift values ​​of the force in the three directions of x, y, and z and the torque in the directions of rotation around the three axes of the six-dimensional force sensor; Load gravity, moment and position of load center of gravity in force sensor coordinate system {S} (x g , y g , z g ) satisfy: 。 4. The robot compliant assembly control method for aircraft flap components according to claim 1, characterized in that: In step 7 and step 8, variable admittance control is used to switch between the fast force control mode and the slow force control mode; The parameter variation range of variable admittance control is the experimental calibration result, in which the virtual stiffness coefficient is zero, the virtual mass and virtual damping parameters are adjusted, the admittance parameter values ​​of the critical state of no jitter and jitter are recorded, the system state is divided into the jitter range and the no jitter range, and the system force control drag speed adjustment range is set in the no jitter range; In steps 7 and 8, the operator's intention is always identified: When the output acceleration of the admittance model is not 0, and the direction of acceleration is the same as the direction of velocity, acceleration occurs; When the output acceleration and velocity are both 0, or the external force is 0, it stops; In other cases, when the external force is not 0, the operation intention is to decelerate; This process is expressed as follows: ； Where, F is the external force after gravity compensation; and They are the speed and acceleration in the i-axis direction respectively, i is the translation and rotational degrees of freedom in the x, y, and z directions of the robot end, and the acceleration and deceleration of each axis run separately.

5. The aircraft flap component robot compliant assembly control method according to claim 1, characterized in that: In step 9, the single force control end adjustment amount is set according to the adjustment distance. The single-step adjustment amount change range of the translation axis is [0.005mm, 1mm], and the single-step adjustment amount change range of the rotation axis is [0.001°, 0.1°].

6. The robot compliant assembly control method for aircraft flap components according to claim 1, characterized in that: In step 10, the force control trigger upper and lower thresholds [F B , F T ], including: The slide rail connection part of the aircraft flap sample is equipped with a floating structure, and the range of its compression or tension force is [F S1 , F S2 ]; Force control trigger lower threshold F B Determined by the minimum compression force of the floating mechanism; the upper threshold F of the force control trigger T Determined by the maximum compression or tension force of the floating mechanism; The implementation logic is as follows: ； In the formula, is the external force on the i-th axis after gravity compensation; i is the translation and rotational freedom of the robot end in the x, y, and z directions.

7. The robot compliant assembly control method for aircraft flap components according to claim 1, characterized in that: In step 13, the motion trajectories L1 and L2 are the motion trajectory information of the robot in the base coordinate system {B}, L E is a theoretical trajectory of an uncertain position in space. During the fitting process, the trajectory L E Defined in the robot base coordinate system {B}, the assembly trajectory with the smallest difference from the two trajectories L1 and L2 is obtained : 。 8. A robot compliant assembly system for aircraft flap components, characterized in that: Used to perform the robot compliant assembly control method of aircraft flap components according to any one of claims 1 to 7; The aircraft flap component robot compliant assembly system comprises: A product bracket is arranged at a predetermined position in a predetermined working space; an aircraft flap and an aircraft flap sample are placed on the product bracket; An assembly object is arranged at a predetermined position within a predetermined workspace; AGV automatic guided vehicle, moves within a predetermined workspace; An industrial robot is arranged on the AGV automatic guided vehicle; the end fixture of the industrial robot clamps the aircraft flap sample; the industrial robot can reach the product bracket and the assembly object under the movement of the AGV automatic guided vehicle; The six-dimensional force sensor is installed between the flange and the end fixture of the industrial robot, and can sense external force information from the end fixture, aircraft flap, and aircraft flap sample.

9. An electronic device, characterized in that: include: A processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface communicate with each other via the communication bus; The memory is used to store a plurality of executable instructions, and the executable instructions enable the processor to execute the aircraft flap component robot compliant assembly control method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The storage medium stores a plurality of executable instructions, and when the executable instructions are executed on the electronic device, the electronic device executes the aircraft flap component robot compliant assembly control method according to any one of claims 1 to 7.

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