A sensor-free robotic arm collision detection method

Abstract

The invention discloses a sensorless mechanical arm collision detection method. The method comprises the steps that a rectangular projection matrix of the joint moment vector generated by the load ofthe tail end of a mechanical arm to the mechanical arm is calculated, and a moment transformation matrix of the load of the tail end of the mechanical arm is obtained according to the rectangular projection matrix; a mechanical arm body kinetic model is set up, a mechanical arm momentum deviation observer is set up according to various items in the kinetic model, the joint external moment vector of the mechanical arm is obtained through the momentum deviation observer, and the collision moment of the mechanical arm is calculated out according to the external moment vector and the moment transformation matrix of the load of the tail end of the mechanical arm; and the collision moment of the mechanical arm and a preset threshold value are compared, and whether a collision happens to the mechanical arm or not is judged. According to the collision detection method, collision detection of the mechanical arm with the load at the tail end can be achieved, and the method is simple, efficient and low in cost.

Description

technical field [0001] The invention relates to the field of industrial robots, in particular to a sensor-free mechanical arm collision detection method. Background technique [0002] The use of series multi-joint manipulators in modern automated industrial production is more popular. During the normal working process of the manipulator, it may collide with people or objects around. This situation may not only cause damage to the manipulator, but also may cause damage to the staff. cause some damages. In addition, human-machine collaborative robots that have been gradually developed in recent years do not need protective fences and can work collaboratively with staff in the same environment. When man-machine collaboration is working, staff sometimes need to actively touch the working robotic arm to pause the robotic arm Therefore, whether it is an active normal collision or a passive abnormal collision for the manipulator must be detected. Based on the above, in order to e...

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Problems solved by technology

This method generally requires a relatively accurate dynamic model of the manipulator body, and the end of the manipulator will carry a certain load or the load will change during the actual work process after leaving the factory. The dynamic model of the manipulator body can no longer adapt to this In the case of load, the original collision detection will bring large errors or even false positives and false positives. The dynamic modeling and parameter identification of the robotic arm must be performed again, and this kind of work generally requires on-site operation by professionals proficient in robot control. As well as a large number of calculations, ordinary operators cannot perform them, causing inconvenience in practical applications, increasing factory operating costs and failing to achieve high collision detection accuracy

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