Oscar Camacho

Sliding Mode Control: Implementation Like PID for Trajectory-Tracking for Mobile Robots

Most of the controllers design are based on a process model. Generally, the processes are nonlinear, of high order and thus the number of tuning parameters for the controller are in proportion to the model order. Mobile robot models are nonlinear and complex, and the use of traditional procedures to design the SMC would result in a really extensive and probably inefficient expression. For that reason, the robot platform will be treated as a black-box, where only the input and output signals are known, and from them a linear low order model obtained. The linear model is used to synthesize the controller. Therefore, this paper proposes a general approach using a linear low order model of the robot for the SMC implementation. The designed controller has tuned parameters based in the use of a PID-like surface, which simplifies the implementation and avoids the use of the complete model of the robot. A robot Pioneer 3DX is used to test the controllers performance when tracking a square trajectory.

A fixed-frequency Sliding-mode control in a cascade scheme for the Half-bridge Bidirectional DC-DC converter

For the Half-bridge Bidirectional DC-DC power converter focused on electric traction applications, this paper develops a fixed-frequency Sliding-mode control (SMC) based on a cascade structure. First, the use of cascade control is justified by means of the state space small-signal averaged equations. Then, the design of the proposed cascade SMC scheme is detailed. Lastly, the simulation results showed that the developed control strategy outperforms the sole use of SMC for different comparison scenarios.

Trajectory tracking for quadcopter's formation with two control strategies

The aim of this paper is to analyze the performance through the ISE index between the two techniques SMC and PD control for quadcopters formation based on a virtual structure by establishing geometrical relationships between the virtual leader (centroid) and quadcopters located in each vertex. The controllers are used for stabilization and trajectory tracking. To analyze the stability, the direct method of Lyapunov is used.

Sliding Mode Control: An Approach to Control a Quadrotor

This paper describes the synthesis and application of controller based on sliding mode theory to a quad rotor. A PD sliding surface is considered for vertical take-off and landing aircraft, also changes in angles are done, and some disturbances are included. Therefore, the controller can be implemented using a PD controller as the sliding surface, and adding some algebra the complete controller algorithm is presented. The controller is tested by simulations.

Adaptive sliding mode control based on fuzzy logic for variable dead time processes

This paper aims to show an adaptive control scheme of Sliding Mode Control and Fuzzy Logic to adjust the tuning parameters of a Sliding Mode Controller (SMC) when it is used for variable dead time systems. The idea behind this work is to take advantage of the fuzzy adapting part to improve the performance of the Sliding Mode Control approach. The original Sliding Mode Control yields a limited performance when applied to variable dead time processes. A simple identification procedure is used to obtain the characteristic parameters of the process. Later they are used to calculate the original tuning parameters of the Sliding Mode control, that represent the initial tuning values for the controller, then the fuzzy adaptive scheme part acts to adjust these tuning parameters in order to get a better performance.

Optimal location of sliding mode control and power system stabilizers in order to damp electromechanical oscillations using the residue

The purpose of this work is to find the optimal location of sliding mode control and power system stabilizer in order to damp electromechanical oscillations in the power system using the residue method. The proposed control is evaluated performing several simulations on a modified version of the 39-bus New England power grid. A modal analysis is performed at the test system in order to evaluate numerically the effect of the proposed control. The matrices A, B, C and D are exported from the software DigSILENT to the MATLAB simulation software with the purpose to determine the Residue and find the optimal location of a Sliding Mode Control and PSS. The controller is added to the automatic voltage regulator of the select generator.

A new approach of a Numerical Methods Controller for self-regulating processes

The aim of this paper is to design a Numerical Methods Controller (NMCr) based on a first order plus dead time (FOPDT) model of the actual process. The overall idea is to develop a general NMCr, which can be used for different self-regulating industrial processes, if they have a similar open loop response, such as an FOPDT model. Hence, this work summarises the easily and simplicity of numerical methods procedures along to a reduced order model of the process to obtain a simple and versatile controller. The performance of the proposed controller in this article is tested by simulations in several higher order linear systems with different characteristics. It is compared against a PID, and also its robustness is checked.

Two-wheeled inverted pendulum path planning: An experimental validation

This paper presents experimental results of a two-wheeled inverted pendulum path planning. The model of the robot, which has six identified variables, is linearized by least squares estimation. A Linear-quadratic Regulator is designed to maintain the robot stabilized, while it moves over a path. Furthermore, an integral part is added to the controller in order to achieve steady state equal to zero. Thus the result is an optimal PI controller. The path planning is designed using a Rapidly Exploring Random Tree Connect method. In addition, two algorithms are presented to improve the quality of the path, the first algorithm reduces the redundant paths and the second algorithm uses the Bezier curves to smooth the path.