Admittance control method, device and system for avoiding singularity type of robot

Abstract

Embodiments of the present invention provide a method, device and system for controlling the admittance of a robot to avoid singularities. The admittance control method first determines the performance index of the target robot according to the current joint angle of the target robot, and the performance index Include at least a translational performance index as well as a rotational performance index. That is, the decoupling of translation and rotation motion in Cartesian space is realized. Then, based on the translation performance index and the rotation performance index, the deformation amount and the stiffness vector of the virtual constraint are determined. A target virtual constraint force is determined based on the deformation amount of the virtual constraint and the stiffness vector. Based on the target virtual constraint force, a target joint angle is determined. It can be seen that this scheme uses the minimum singular value of the robot Jacobian matrix to measure the performance index of the robot, and judge whether the robot is close to the singular position type. Since the gradient variance of the performance index in this scheme is small, it can avoid the momentary virtual constraint force in the process of human-computer interaction. shake.

Description

technical field [0001] The invention relates to the technical field of robot control, in particular to an admittance control method, device and system for avoiding singularities of robots. Background technique [0002] With the development of intelligent manufacturing, collaborative robots have been widely used in auxiliary industrial operations, collaborative assembly, housework, entertainment, medical care and other fields. Since humans and robots need to work closely together in the same workspace, safety and reliability during human-robot interactions are of paramount importance. In order to ensure smooth human-computer interaction, robot admittance control is usually used to control robot motion. However, in the process of human-computer interaction, the robot will inevitably have a singular position. When the robot is close to the singular position, it will cause the robot to move unstable or even stop, which will seriously affect the experience of human-computer inte...

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Problems solved by technology

[0006] The inventor found that method 1 is easy to operate, but it greatly affects the experience of human-computer interaction, and the robot needs to be restarted

Although method 2 can make the robot unable to reach the singular position, but using the operability to judge whether the robot is singular, there is a large variance, which will lead to instability in the process of human-computer interaction, and will appear at the moment when the virtual constraint force is applied due to insufficient acceleration. Continuously caused jitter; in addition, this method does not decouple translation and rotation motions, resulting in translation and rotation motions coupled together, which cannot be controlled separately, affecting user experience

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