By using the hierarchical controller approach, a new solution for the control problem related to trajectory tracking in a differential drive wheeled mobile robot (DDWMR) is presented in this paper. For this aim, the dynamics of the three subsystems composing a DDWMR, i.e., the mechanical structure (differential drive type), the actuators (DC motors), and the power stage (DC/DC Buck power converters), are taken into account. The proposed hierarchical switched controller has three levels: the high level corresponds to a kinematic control for the mechanical structure; the medium level includes two controls based on differential flatness for the actuators; and the low level is linked to two cascade switched controls based on sliding modes and PI control for the power stage. The hierarchical switched controller was experimentally implemented on a DDWMR prototype via MATLAB-Simulink along with a DS1104 board. With the intention of assessing the performance of the switched controller, experimental results associated with a hierarchical average controller recently reported in literature are also presented here. The experimental results show the robustness of both controllers when parametric uncertainties are applied. However, the performance achieved with the switched controller introduced in the present paper is better than, or at least similar to, performance achieved with the average controller reported in literature.
A sensorless control based on the exact tracking error dynamics passive output feedback (ETEDPOF) methodology is proposed for executing the angular velocity trajectory tracking task on the “full-bridge Buck inverter–DC motor” system. When such a methodology is applied to the system, the tracking task is achieved by considering only the current sensing and by using some reference trajectories for the system. The reference trajectories are obtained by exploiting the flatness property associated with the mathematical model of the “full-bridge Buck inverter–DC motor” system. Experimental tests are developed for different desired angular velocity trajectories. With the aim of obtaining the experimental results in closed-loop, a “full-bridge Buck inverter–DC motor” prototype, Matlab-Simulink, and a DS1104 board from dSPACE are employed. The experimental results show the effectiveness of the proposed control.
This work addresses the control problem related to the bidirectional velocity of a DC motor feeded by a DC/DC Buck converter–inverter as power amplifier. While various power electronic topologies have been proposed in literature, this research focuses on one that was previously disregarded due to its delivery of pulse width modulated voltage signals instead of smooth voltage signals to the DC motor. However, in the present paper it is demonstrated that by appropriately controlling the power electronic converter it is indeed possible to deliver the desired smooth voltage signals to the motor. Moreover, the proposed control strategy is robust, employing multiple proportional-integral loops, and a sliding mode controller. A formal proof of asymptotic stability is provided and the robustness is verified through experimental validation.
1 January 2013 in Mathematical Problems in Engineering
This paper presents a two-stage control design for the “Buck power converter/DC motor” system, which allows to perform the sensorless angular velocity trajectory tracking task. The differential flatness property of the DC-motor model is exploited in order to propose a first-stage controller, which is designed to achieve the desired angular velocity trajectory. This controller provides the voltage profiles that must be tracked by the Buck converter. Then, a second-stage controller is meant to assure the aforementioned. This controller is based on flatness property of the Buck power converter model, which provides the input voltage to the DC motor. Due to the fact that the two-stage controller proposed uses the average model of the system, as a practical and effective implementation of this controller, a-modulator is employed. Finally, in order to verify the control performance of this approach, numerical simulations are included.
In this work a three-level controller that carries out the trajectory tracking task for a differential drive wheeled mobile robot (WMR) is presented. Such a controller considers, for the first time in literature, the dynamics associated with the three subsystems that compose a WMR, i.e., mechanical structure, actuators, and power stage. The high level corresponds to an input-output linearization control for the mechanical structure; the medium level is based on two sensorless controls designed via differential flatness for the actuators; and the low level is related to two cascade controls based on sliding modes and PI control for the power stage. The performance and robustness of the controller is verified and shown via realistic simulations when parametric uncertainties associated with the subsystems that compose the WMR are considered.
This paper presents a passivity-based control for the DC/DC Buck-Boost converter-inverter-DC motor system. Such control exploits the energy structure associated with the system error dynamics. This in order to solve the trajectory tracking task for both the converter voltage and motor bidirectional angular velocity, without using electromechanical sensors. The successful experimental validation of the proposed control is performed in a built prototype of the system, using Matlab-Simulink and a DS1104 board.