Observer-Based Controllers for Two-Wheeled Inverted Robots with Unknown Input Disturbance and Model Uncertainty

Abstract

<jats:p>In this paper, two controllers with a compound disturbance observer are proposed for a two-wheeled inverted robot (TWIR) with model uncertainty and unknown input disturbance. First, an equivalent linear model of the TWIR with uncertainty and input disturbance is proposed using the Taylor series expansion for the nonlinear model of the TWIR at an equilibrium point, in which the nonlinear part of the Taylor series and the model uncertainty are combined with unknown input disturbance as compound input disturbance. Then, the compound input disturbance is estimated by using the Newton method and reference model. As the estimated compound disturbance is used to compensate for the compound disturbance, the equivalent linear system becomes closely definite without compound input disturbance. Finally, two controllers are proposed using the equivalent linear system. Stability analysis of the proposed control methods is also given. To illustrate the proposed methods, some simulations for the TWIR are performed and compared with the existing methods. The main contribution of this work includes the following: (i) simple controllers based on compound input disturbance observer for trajectory tracking and balancing of TWIRs with unknown input disturbance and model uncertainty are proposed; (ii) the stability of proposed closed-loop control systems is proved; (iii) our proposed methods are simulated and compared with the existing methods.</jats:p>

Improve the quality of Industrial Robot Control Using an Iterative Learning Method with Online Optimal Learning and Intelligent Online Learning Function Parameters

“…Set up the sum vector. ε từ () ei , i=0,1...,S-1 theo (11) Update vector v from its existing value according to (10)…”

“…We obtain the simulation results in Figure 4, Figure 5, Figure 6 and Figure 7. The simulation results in Figure 4 and Figure 5 show that, when combined with the identification and noise compensation stages of the traditional controller (13), the iterative learning controller (11) has achieved good signal tracking quality. The preset error with tracking error after 60 trials is small enough and acceptable:…”

“…It depends on time and does not require periodicity, so it can be considered an intelligent model-matching control method. This method is based on theoretical results on optimal control of each segment on the time axis available in [10] and applying disturbance estimation to control self-balancing two-wheeled vehicles [11].…”

Survey on Robust Control Applications in Inverted Pendulum Systems

“…With an observer based state feedback concept, Siliet and Yaman could make an onoff type cold gas thrusters controlled rotary inverted pendulum [20]. In [21] a compound disturbance observer is proposed by Trans et.al.…”

A simple approach to estimate unmatched disturbances for nonlinear nonautonomous systems

“…Various different systems have dealt with disturbance such as multi‐input multi‐output (MIMO) nonlinear systems with mismatching condition, 28 single‐input single‐output (SISO) uncertain nonlinear systems with unknown hysteresis, 29 a flapping wing micro aerial vehicle, 30 nonlinear cascaded systems, 31 and SISO high‐order strict‐feedback nonlinear systems 32 . Especially, a matched disturbance estimator was proposed for a class of nonlinear autonomous systems using time receding optimization principle in References 33 and 34. However, until now there has not been any disturbance observer available for nonlinear nonautonomous systems with unmatched disturbance to the best of our knowledge.…”