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Mobile robots in industry are commonly used in warehouses and factories. To achieve the highest production rate, requirements for path planning algorithms have caused researchers to pay significant attention to this problem. The Artificial Potential Field algorithm, which is a local path planning algorithm, has been previously modified to obtain higher smoothness of path, to solve the stagnation problem and to jump off the local minimum. The last itemized problem is taken into account in this paper—local minimum avoidance. Most of the modifications of Artificial Potential Field algorithms focus on a mechanism to jump off a local minimum when robots stagnate. From the efficiency point of view, the mobile robot should bypass the local minimum instead of jumping off it. This paper proposes a novel Artificial Potential Field supported by augmented reality to bypass the upcoming local minimum. The algorithm predicts the upcoming local minimum, and then the mobile robot’s perception is augmented to bypass it. The proposed method allows the generation of shorter paths compared with jumping-off techniques, due to lack of stagnation in a local minimum. This method was experimentally verified using a Husarion ROSbot 2.0 PRO mobile robot and Robot Operating System in a laboratory environment.

Purpose -The purpose of this paper is to discuss the design and verification of a non-classical structure of servo-drive controller with the state feedback and a load torque feedforward compensation. Design/methodology/approach -First a well known nonlinear mathematical model of a PMSM is transformed into a linear form by introducing new variables. The state space new model presented in rotated orthogonal reference frame is decoupled by means of equation in d and q axis. To achieve correct dynamic performance of the servo-drive system the state feedback with an internal input model and load torque feedforward compensation is proposed. The observed load torque has been used as an input signal for the feedforward compensator. The design of the control system and simulation analysis were performed in Matlab/Simulink. The proposed control algorithm was implemented in a DSP controller (TMS320F2812). The experiments were carried out by using a 0.6 kW PMSM drive system. Findings -It is shown that the proposed compensator can eliminate the effects of load torque changes by steady-state operation and significantly improve dynamic behaviour during load changing. A novel mathematical formula how calculate an appropriate gain for feedforward compensator is given. Research limitations/implications -Analysis of possible disturbance compensation shows that full dynamic compensation of disturbance is impossible. Only the compensation of load torque for a steady state is possible. The described control structure operates without state variables limitations so it is not recommended to application where the high dynamic of transient process is required. Practical implications -The proposed control system can be used in industrial applications where load torque compensation is needed instead the high dynamic performance. Originality/value -Presented mathematical formula how calculate an appropriate gain for feedforward compensator is a theoretical contribution of the authors. The test results are consistent with the computer simulation test results and validate the correct dynamic performance of the proposed control method.