Adaptive Sliding Mode Control of Switched Constrained Robotic Manipulators

In this paper, we address the control problem of a
constrained robotic manipulators with their constraints
continuously switched from one to another. Such a switching in
the constraints causes a switching function to be inserted in the
equation of the robot dynamics which may cause transient
instability for the overall system. Two robust control strategies
are presented in this paper to handle such switched robotic
systems. In the first strategy, we assume that the bounds of the
constraints are known. A sliding mode stabilizing controller is
developed that can guarantee global stable performance of the
given robotic system. In the second one, we relax the assumption
of knowing the constraints bounds through deriving update laws
for those bounds and new control actions that can guarantee
global stable performance under such switching constraints.
Simulation is performed for a two link robotic system having two
switching constraints. The results obtained from the simulation
verify the efficacy of the suggested control strategy.