Adaptive Polar-Space Motion Control for Embedded Omnidirectional Mobile Robots with Parameter Variations and Uncertainties

Abstract

This paper presents an adaptive polar-space motion controller for trajectory tracking and stabilization of a three-wheeled, embedded omnidirectional mobile robot with parameter variations and uncertainties caused by friction, slip and payloads. With the derived dynamic model in polar coordinates, an adaptive motion controller is synthesized via the adaptive backstepping approach. This proposed polar-space robust adaptive motion controller was implemented into an embedded processor using a field-programmable gate array (FPGA) chip. Furthermore, the embedded adaptive motion controller works with a reusable user IP (Intellectual Property) core library and an embedded real-time operating system (RTOS) in the same chip to steer the mobile robot to track the desired trajectory by using hardware/software co-design technique and SoPC (system-on-a-programmable-chip) technology. Simulation results are conducted to show the merit of the proposed polar-space control method in comparison with a conventional proportional-integral (PI) feedback controller and a non-adaptive polar-space kinematic controller. Finally, the effectiveness and performance of the proposed embedded adaptive motion controller are exemplified by conducting several experiments on steering an embedded omnidirectional mobile robot

Passivity-based control of an omnidirectional mobile robot

“…In [ 2 ], a linear optimal tracking controller was designed, in which the main idea is to simplify the dynamics of the three-wheeled OMR as a linear time invariant model by using the kinematics. In [ 3 ], based on a dynamic model without considering motor dynamics, an adaptive motion controller was synthesized via the adaptive backstepping approach. In [ 4 ], feedback linearization strategy was used to compensate the static friction, and then a model-predictive control scheme was applied to trajectory tracking control of a three-wheeled OMR.…”

A Taguchi-Based Heterogeneous Parallel Metaheuristic ACO-PSO and Its FPGA Realization to Optimal Polar-Space Locomotion Control of Four-Wheeled Redundant Mobile Robots

“…Polar-space locomotion controllers of mobile robots have been proven superior to the Cartesian controllers in tracking the special trajectories, such as Archimedes' spiral, rose curves, and Limacon of Pascal [29]- [33]. These trajectories are easily described in polar coordinates, but they are more complex in Cartesian space.…”

“…The polar-space tracking problems for nonholonomic mobile robots have been investigated by several researchers [29]- [31]. There have been few studies related to holonomic three-wheeled polar-space omnidirectional mobile robot control [32], [33], in which the control parameters are obtained by a trial-and-error approach. However, to the authors' best understanding, the polar-space redundant control problem of four-wheeled mobile robots remains open.…”

A continuous dynamic modeling approach for an omnidirectional mobile robot

“…It should be pointed out that, in all previous studies, the continuous dynamic models for Swedish wheeled or Omni-wheeled OMRs were directly obtained by viewing both wheels as non-switch wheels. [19][20][21][22][23][24] In [1], for the first time, we proposed an average dynamic modeling approach for an OMR with MY wheels-II, in which the real contact radius in the discontinuous dynamic model is replaced by an average contact radius. The average modeling approach results in a smooth non-linear dynamic model.…”