Symmetric Time-Variant IBLF-Based Tracking Control with Prescribed Performance for a Robot

In this work, an improved symmetric integral barrier function-based tracking control is addressed for a robotic manipulator in the presence of position error performance requirements and unknown uncertain terms. First of all, we construct an improved symmetric time-variant integral barrier function to solve the robotic system's constrained requirements. The novel barrier function is constructed by developing an integral upper limit function that can be used in conjunction with existing performance envelope functions. Then, the equivalent conversion error is taken as the upper limit of the integral function to achieve the specified steady-state as well as transient behaviors of the system. Additionally, a disturbance observer based on the velocity tracking error is introduced to compensate for unknown uncertain terms. In the end, a numeral simulation study on a robot with two degrees is performed to indicate that the present scheme is feasible in handling the performance constraint and uncertain terms.