Variable admittance assisted large component assembly method and system based on operating intention recognition

Abstract

The present invention relates to the field of human-computer interaction assembly of large-size components by using heavy-duty industrial robots, and provides a variable admittance assisted large component assembly method and system based on operating intention recognition. The variable admittance compliant assisted assembly method includes: considering suppression System inertia and human-computer interaction work compliance, optimize the constant admittance control method, build a variable admittance control model based on human operation intention recognition; combine the influence of admittance coefficient on control, design and select the experimental plan of admittance coefficient, and analyze the variable admittance control model. Admittance control characteristics; according to the requirements of different stages of auxiliary assembly, customize the corresponding robot end motion rules in free space and constrained space; based on the safe working space of the robot, establish a virtual limit wall to limit the dragging range. The method of the present invention has good operation flexibility and strong inertia overcoming ability, and simultaneously considers the application of heavy-duty robots for auxiliary assembly of large parts in free space and restricted space, and has good practicability and versatility.

Description

technical field [0001] The invention relates to the field of G05D: non-electric variable control or adjustment system, and specifically relates to a variable admittance assisted assembly method and system for large components based on operating intention recognition. Background technique [0002] With the continuous improvement of the automation level of aviation manufacturing, major aircraft manufacturing companies have successively started research on applying industrial robots to aircraft automatic assembly, aiming at improving assembly accuracy and assembly safety. Reasonable compliant control methods can not only ensure the safety and efficiency of cooperative tasks, but also greatly reduce the burden of humans in the tasks. Robot active compliance control is divided into impedance control, admittance control, position force hybrid control and so on. Compared with the other two methods, admittance control has the characteristics of low environmental requirements and no...

AI Technical Summary

Problems solved by technology

However, the above-mentioned patent scheme does not define the comfort force. Only one comfort force is used to control different situations of dragging, which is difficult to meet the operator's requirements for comfort force, and it is adjusted according to the virtual damping generated by the operator's comfort force. The strategy is to control the coefficient through the robot's motion speed. This not only requires a greater force to be applied in the early stage of motion, but also slows down when stopping the robot, resulting in a large system inertia and potential safety hazards.

In addition, the system only considers the adjustment of the virtual damping value, ignoring the influence of the virtual mass on the system, and it is easy to affect the instability of the system poles

Therefore, aiming at the defect that human-computer interactive robots in the prior art cannot quickly and sensitively respond to the operator's intentions, the Chinese patent "CN109910005A, Variable Admittance Control Method and System for Robots" designed a pure acceleration and deceleration method for human beings. The control law of each admittance coefficient under the intention, but it does not consider the influence of the sudden change of the admittance coefficient on the motion state of the system caused by the robot's deceleration to acceleration process in the reverse intention stage, nor does it consider the influence of the robot when the speed is large or the human desires The suppression of system inertia when the robot stops moving, etc., the control stability and safety are poor

And the safety measures set are to control the robot to stop forcibly when the moving speed of the drag exceeds a certain value. Continuing to drag the part, thus easily causing damage to the sensor

At the same time, the system only considers the human-computer interaction in free space, and does not involve the situation in constrained space, so the engineering application is weak

The master's thesis "Aircraft flap robot-assisted assembly compliant control technology" proposed a variable admittance control method based on human intention recognition in free space and trackless constrained space, but ignored the influence of system inertia on dragging large load components, and did not The inertia of the system is effectively suppressed, making it slow to change the robot's motion state, and the system's flexibility is low. At the same time, it does not consider the safe working space of the heavy-duty robot, which has a large safety hazard

[0004] To sum up, in the existing control scheme, the inertia suppression of heavy-duty robots is not obvious, and the setting of the admittance coefficient is difficult to accurately track the change of operation intention under the condition of heavy load, and the comfort and safety of the system operation are low.

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