Humanoid robots, unmanned rovers, entertainment pets, drones, and so on are great examples of mobile robots. They can be distinguished from other robots by their ability to move autonomously, with ...

https://journals.sagepub.com/doi/pdf/10.1177/1729881419839596

A review of mobile robots: Concepts, methods, theoretical framework, and applications

Review of modelling and control of two-wheeled robots

Fault-tolerant iterative learning control for mobile robots non-repetitive trajectory tracking with output constraints

In terms of the state-dependent Riccati equation (SDRE) control framework, a nonlinear motion control is investigated for the two-wheeled inverted pendulum (TWIP) mobile robot platform. As a critical design issue, the state dependent coefficient matrix is established based on the sound understanding of dynamic characteristics of the TWIP robot. The developed SDRE control solution has the merit of robust posture stabilization when the inverted pendulum robot experiences strong nonlinear behaviors due to abrupt external disturbances.

Nonlinear Optimal Control Design for Underactuated Two-Wheeled Inverted Pendulum Mobile Platform

The key attributes of Two Wheeled Balancing Mobile Robots (TWBMRs) are nonholonomic constraints and inherent instability. This paper deals with the problem of balancing and trajectory tracking of TWBMR using backstepping Sliding Mode Controller (SMC). First, the mathematical representation of TWBMR is derived using Lagrangian method by incorporating the dynamics of DC motors. Then, a decoupling approach is applied for simplifying the dynamic equations. The backstepping SMC technique is finally adopted to achieve the balancing and trajectory tracking of the TWBMR, whereas both model uncertainties and exogenous disturbance are taken into account in the controller design methodology. In order to determine the velocity, the trajectory tracking is achieved by the kinematic control, which is a common backstepping controller. For the velocity convergence of TWBMR to the generated desired value, two SMCs are designed, in which the motors voltage are directly controlled as the control laws. Simplicity in practical implementation and control law, ability to overcome uncertainties and appropriate performance are the main advantages of the proposed controller. The effectiveness of the proposed controller is verified through simulation and experimental results.

Balancing and Trajectory Tracking of Two-Wheeled Mobile Robot Using Backstepping Sliding Mode Control: Design and Experiments

Ground traction is very important for balancing of two-wheeled robots. This paper examines whether limiting wheel slip to a nominal optimal value, as in conventional traction control, improves the performance of two-wheeled robots on low traction surfaces. For a particular robot and simulation conditions, comparing the baseline linear state feedback controller of the two-wheeled robot with and without traction control shows that conventional traction control is ineffective when stopping abruptly from a constant speed.

Traction control on a baseline controller decreases the maximum stable stopping speed on an ice-like surface. Compensating torque induced by traction control only partially recovers performance. On a hypothetical wet or lubricated surface with exaggerated Stribeck effect, traction control only slightly improves performance. Therefore traction control distinct from the balance and velocity LQR controller is ineffective, normally degrades overall performance, and motivates research for an alternative controller.

Ronald Ping Man Chan

Papers

Review of modelling and control of two-wheeled robots

Effect of limiting wheel slip on two-wheeled robots in low traction environments