Fusion dynamic model based fault tolerant control for collaborative robot manipulators

In the rapidly developing field of robot manipulators, there are many applications that go beyond the capabilities of a single robot manipulator, and these applications involve a wide range of fields, such as grasping objects of any shape, handling large or heavy objects, matching suitable parts, and other tasks. Therefore, the collaborative working mode of multiple robot manipulators has emerged. The research object of this article is a collaborative system of multiple planar robot manipulators jointly gripping an object. However, unlike ordinary nonlinear systems with many mature solutions, manipulator systems have their own characteristics, that is, nonholonomic constraints. This is a non-integrable constraint imposed on motion. Angular momentum is a typical non-integrable conserved quantity, so the systems with rolling constraint and mechanical systems with sliding constraint are common systems with non-integrable first order constraint. Firstly, a decentralized dynamic model is constructed to describe the fusion system between a planar robot manipulator and the clamped object. Secondly, a fault-tolerant control scheme based on sliding mode control is designed for actuator additive fault. Finally, an example of a planar robot manipulators with three joints and an object being gripped is taken to illustrate the effectiveness of the proposed methods.