CN-122009511-A - Large part flexible unloading method and system based on force value feedback control

CN122009511ACN 122009511 ACN122009511 ACN 122009511ACN-122009511-A

Abstract

The invention relates to the field of aircraft large part assembly, and discloses a large part flexible shelving method and a system based on force value feedback control, wherein the flexible shelving method comprises the steps of installing a three-dimensional force sensor on a numerical control positioner, calibrating the direction of the sensor and setting a force value threshold; the method comprises the steps of installing a lifting rope at the position of a lifting point of a large part, lifting the lifting rope to enable the lifting rope to bear force, determining descending sequence of Z axes of all positioners according to a mathematical model of the large part, sequentially descending the Z axes of the positioners according to the sequence, monitoring force born by the positioners in the descending process, stopping descending when a X, Y directional force value exceeds a threshold value, moving X axes and Y axes of the numerical control positioners through a force feedback control algorithm, and continuing descending the Z axes of the positioners after the value of a force sensor reaches a target value until a ball head of the large part is separated from a ball socket of the positioners. The invention solves the problems of stress pulling, extrusion and the like in the process of putting the large part down, and avoids the risk of damaging the large part and the positioner.

Inventors

Zeng Taizhi
LIU QINWAN
ZENG QIN
WANG FEI
LI ZHIQIANG
SHE JIAN
LIU XU
ZHANG YINGHONG
ZHAO SHUAI
SHI YINGHAO
SHEN YUJUN

Assignees

成都飞机工业（集团）有限责任公司

Dates

Publication Date: 20260512
Application Date: 20260210

Claims (10)

1. A method for flexibly unloading a large part based on force value feedback control, which is characterized by comprising the following steps: S1, respectively installing three-dimensional force sensors on numerical control positioners for supporting large parts, calibrating the directions of the three-dimensional force sensors and setting a force value threshold; s2, determining the position of a hanging point of the large part, installing a hanging rope at the hanging point, lifting the hanging rope and stressing the hanging rope; s3, determining the descending sequence of the Z axis of the numerical control positioner according to the mathematical model of the large part; s4, sequentially descending the Z axis of the numerical control positioner according to descending order, monitoring the numerical value of the three-dimensional force sensor on the positioner in real time in the descending process, stopping descending when the X, Y-direction force value exceeds a threshold value, moving the X axis and the Y axis of the numerical control positioner through a force feedback control algorithm to enable the numerical value of the three-dimensional force sensor to reach a target value, and then continuing to descend the Z axis of the positioner until the ball head of the large part is separated from the ball socket of the numerical control positioner; And S5, repeating the step S4 until all the ball heads are separated from the ball sockets of the numerical control locator.
2. The flexible unloading method of the large component based on force value feedback control according to claim 1, wherein in the step S2, the lifting point position of the large component is determined by calculating the gravity center position of the large component based on the stress value of the three-dimensional force sensor in the Z direction, and then determining the lifting point position of the large component according to the calculated gravity center position of the large component.
3. The method for flexibly setting down a large component based on force value feedback control according to claim 1, wherein in step S3, determining the descending order of the Z axis of the numerical control positioner according to the mathematical model of the large component comprises: And establishing a mathematical model of the large part, analyzing the influence of the supporting force provided by any numerical control positioner on the supporting force of the rest positioners after the Z axis of the numerical control positioner is lowered as a target positioner based on the mathematical model, and determining the optimal descending sequence of the Z axis of each numerical control positioner.
4. The method for flexibly unloading a large part based on force feedback control according to claim 1, wherein in step S4, the X-axis and the Y-axis of the numerically controlled positioner are moved by a force feedback control algorithm, and the calculation method is as follows: formula (1); The method comprises the steps of S xk is a distance to be moved at the moment of a positioner X axis k, S yk is a distance to be moved at the moment of a positioner Y axis k, kp is a proportionality coefficient, T is sampling time, ti is integration time, td is differentiation time, e xk is a deviation value between a feedback value of a direction X of a three-dimensional force sensor at the moment of k and a target value, e x（k-1） is a deviation value between a feedback value of a direction X of a three-dimensional force sensor at the moment of (k-1) and the target value, e yk is a deviation value between a feedback value of a direction Y of a three-dimensional force sensor at the moment of k and the target value, e y（k-1） is a deviation value between a feedback value of a direction Y of a three-dimensional force sensor at the moment of (k-1) and the target value, e xj is a deviation value between a feedback value of a direction X of a three-dimensional force sensor at the moment of j and the target value in the integration time, and e yj is a certain moment in the integration time of k.
5. The method for flexibly unloading the large component based on force value feedback control according to claim 4, wherein the deviation value between the real-time feedback value of the X direction of the three-dimensional force sensor at the k moment and the target value and the deviation value between the real-time feedback value of the Y direction of the three-dimensional force sensor at the k moment and the target value satisfy the following relations: formula (2); Wherein F xk is the stress of the three-dimensional force sensor in the X direction at the moment k, F yk is force applied to the three-dimensional force sensor in the Y direction at the time of k, and δ is a target value of the three-dimensional force sensor X, Y.
6. The method for flexibly setting down a large part based on force value feedback control according to claim 5, wherein the stress to which the positioner is subjected is proportional to the deformation amount of the stress within the elastic limit, satisfying the following relationship: Formula (3); Wherein E is the elastic modulus.
7. The method for flexibly setting down a large component based on force value feedback control according to claim 3, wherein after the Z-axis of different numerical control positioners as target positioners is lowered, the variation amplitude of the supporting force of the rest positioners is determined in sequence, and the positioners are lowered preferentially with small variation amplitude.
8. A force feedback control-based large part flexible racking system, characterized in that the force feedback control-based large part flexible racking system is used for realizing the force feedback control-based large part flexible racking method according to any one of the claims 1-7, and comprises the following steps: The numerical control positioner is used for supporting the large part to be put down; The three-dimensional force sensor is arranged on the numerical control positioner and is used for monitoring the stress of the positioner in real time; And in the descending process, receiving real-time monitoring values of the three-dimensional force sensors in real time, stopping descending when the X, Y directional force value exceeds a threshold value, moving the X axis and the Y axis of the numerical control positioner through a force feedback control algorithm to enable the values of the three-dimensional force sensors to reach a target value, and then continuing to descend the Z axis of the positioner until the ball head of the large part is separated from the ball socket of the numerical control positioner.
9. A storage medium having stored thereon a computer program which, when executed by a processor, implements a method of large part flexible off-shelf based on force value feedback control as claimed in any one of the preceding claims 1-7.
10. A computer device comprising a memory, a processor and a computer program stored on the memory and executable in the processor, the processor implementing a force value feedback control based large part flexible off-shelf method according to any of the preceding claims 1-7 when the computer program is executed.

Description

Large part flexible unloading method and system based on force value feedback control Technical Field The invention relates to the technical field of aircraft large part assembly, in particular to a large part flexible unloading method and system based on force value feedback control. Background Due to the large size of the aircraft, the modules are complex and are typically manufactured in segments. And after the parts are manufactured, assembling the large parts by using an aircraft assembly platform. After the large part is assembled, the large part can be lifted off the frame or lowered down the positioner and moved through the transfer trolley. However, if the assembly platform is limited and the transfer trolley cannot be used, the large part can be put down in a hoisting mode. The lifting rope is a non-rigid tool, so that uneven stress can occur between a large part of ball head and a positioner ball socket in the lifting process, the ball head cannot be separated from the positioner ball socket, and finally the positioner and the large part are damaged. The invention patent with publication number CN112977873A discloses an automatic unloading overturning device for airplane components, which is suitable for the production of the components, can not effectively support the assembled large components, and can not meet the unloading process of the large components in the assembly process. For example, "large aircraft safety off-shelf problem study of attitude adjustment by adopting a three-coordinate numerical control positioner", analysis is carried out on the aircraft off-shelf process, and a motion model is established. However, the article is mainly applicable to complete machines that are already equipped with landing gear, and is not applicable to large parts that are not equipped with landing gear. In addition, only a three-dimensional force sensor is introduced in the article to monitor the force value, and the position of the locator is manually adjusted through monitoring the force value data. For example, the invention patent with publication number CN113219894A discloses a real-time monitoring method for the state of an aircraft tool based on a three-dimensional force sensor, which mainly utilizes the three-dimensional force sensor to monitor, obtain and display the stress condition of a large part, but the value of the three-dimensional force sensor does not participate in the adjustment of a positioner. Disclosure of Invention The invention provides a large part flexible unloading method and a system based on force value feedback control, which aims to solve the defects and the shortcomings in the prior art, firstly, three-dimensional force sensors are arranged on each positioner of large part assembly, and then the numerical value change of the stress of the positioner in the three-dimensional direction is obtained in real time in the hoisting process, and a force feedback control algorithm is called after the force value exceeds a threshold value, so that the positioner X, Y shaft automatically moves, and finally the feedback value of the three-dimensional force sensor in the direction of the positioner X, Y reaches a target value, thereby avoiding the damage of the positioner and large parts. In order to achieve the above object, the present invention has the following technical scheme: The invention discloses a large part flexible unloading method based on force value feedback control, which comprises the steps of unloading large parts of an aircraft by adopting a combination mode of lifting and descending of a numerical control positioner for the first time, and using a value of a three-dimensional force sensor as feedback, so that when the force value born by the numerical control positioner exceeds a threshold value in the unloading process, the positions of an X axis and a Y axis of the positioner are automatically adjusted by using a force feedback control algorithm, and the purpose of flexible unloading is achieved. The technical scheme includes that firstly, a three-dimensional force sensor is installed on a numerical control positioner for supporting a large part, the direction of the force sensor and the direction of an assembly coordinate system are calibrated, so that the directions of X, Y, Z of the force sensors are parallel to each other, secondly, a lifting rope is installed at a lifting point of the large part, the lifting rope is lifted, the lifting rope is stressed, and then, the descending sequence of the Z axis of each numerical control positioner is determined based on analysis of an established mathematical stress model of the large part. And when the numerical control positioners are lowered in sequence according to the determined lowering, the force value monitoring and force feedback control algorithm process is continuously repeated until the Z axes of all the numerical control positioners are lowered in place, all the ball heads of the large components are c