Víctor H. Andaluz

Robust control with redundancy resolution and dynamic compensation for mobile manipulators

This paper presents the tracking control problem of a mobile manipulator system to maintain maximum manipulability and including the obstacle avoidance. The design of the controller is based on two cascaded subsystems: a minimum norm kinematic controller with command saturation, and a controller that compensates for the dynamics of the mobile manipulator system. Robot commands are defined in terms of reference velocities. Stability and robustness to parametric uncertainties are proved by using Lyapunovs method. Experimental results show a good performance of the proposed controller as proved by the theoretical design.

Robust Control with Dynamic Compensation for Human-Wheelchair System

This work presents the kinematic and dynamic modeling of a human-wheelchair system, and dynamic control to solve the path following problem. First it is proposed a dynamic modeling of the human-wheelchair system where it is considered that its mass center is not located at the center the wheels’ axle of the wheelchair. Then, the design of the control algorithm is presented. This controller design is based on two cascaded subsystems: a kinematic controller with command saturation, and a dynamic controller that compensates the dynamics of the robot. Stability and robustness are proved by using Lyapunov’s method. Experimental results show a good performance of the proposed controller as proved by the theoretical design.

3-D path-following with a miniature helicopter using a high-level nonlinear underactuated controller

This work proposes a controller to guide a miniature helicopter during a 3D path-following task, emphasizing its dynamic stabilization, while reaching a set of reference poses. The proposal includes a nonlinear underactuated control strategy previously proposed for the UAV, implemented as an inner closed loop, to stabilize the helicopter in a given reference pose, as well a path-following controller based on the kinematic model of the rotorcraft implemented as an outer closed loop. A proof of the stability of the equilibrium of the whole closed-loop system in the sense of Lyapunov is also presented. Finally, simulation results are presented and discussed, which validate the proposed controller.

Adaptive cooperative control of multi-mobile manipulators

This paper presents a multi-layer scheme for the adaptive coordinated cooperative control of n mobile manipulator. Each layer works as an independent module, dealing with a specific part of the problem of cooperation, coordination and adaptation, thus giving more flexibility to the scheme. Also, the redundancy of the n mobile manipulators is used for the avoidance of obstacles by the mobile platforms-without deforming the virtual structure and maintaining its desired trajectory- and the singular configuration prevention through the systems manipulability control. Stability and robustness are proved by using Lyapunovs theory. Simulation results show a good performance of the proposed control scheme as proved by the theoretical design.

Coordinated cooperative control of mobile manipulators

This paper presents a multi-layer scheme for coordinated cooperative control of mobile manipulators, for transporting a common object. Each layer works as an independent module, dealing with a specific part of the problem of coordination and cooperation, thus giving more flexibility to the system. A methodology to avoid obstacles in the trajectory of any mobile manipulator is designed based on the concept of mechanical impedance of the interaction robots-environment, without deforming the virtual structure and maintaining its desired trajectory. Stability is proved by using Lyapunovs method. Simulation results show a good performance of the proposed controller as proved by the theoretical design.

Passivity-based visual feedback control with dynamic compensation of mobile manipulators

This paper addresses the problem of visual dynamic control based on passivity to solve the target tracking problem of mobile manipulators with eyes-in-hand configuration in the 3D-workspace. The redundancy of the system is used for obstacles avoidance and singular configuration prevention through the systems manipulability control. The design of the stable control system is based on its passivity properties. A robustness analysis and an L 2 -gain performance analysis are also presented. Finally, simulation and experimental results are reported to verify the stability and L 2 -gain performance of the dynamic visual feedback system. We address the problem of visual control to solve the target tracking problem.We consider both the kinematic and dynamic models in the control system design.The design of the stable control system is based on its passivity properties.A robustness analysis and an L 2 -gain performance analysis are also presented.Simulations and experimental results are shown to verify the systems performance.

Switching control signal for bilateral tele-operation of a mobile manipulator

This paper presents both the design and the implementation of a bilateral teleoperation system for a mobile manipulator, allowing a human operator to perform complex tasks in remote environments. Two teleoperation operation modes are proposed: the locomotion mode (mobile manipulator) and the manipulation mode (robotic arm). The human operator can select the modes through the switch located on a haptic device. The user receives visual and force feedback from the remote site, and it sends velocity or position commands to the slave, according to the operation mode. Furthermore, the redundancy control of the system for obstacle avoidance is considered by the mobile platform, and the singular configuration prevention through the systems manipulability control. Finally, experimental results are reported to verify the performance of the proposed system.

Multilayer scheme for the adaptive cooperative coordinated control of mobile manipulators

This paper presents a multi-layer scheme for the adaptive cooperative coordinated control of mobile manipulator robots. Each layer works as an independent module, dealing with a specific part of the problem of cooperation, coordination and adaptation, thus giving more flexibility to the scheme. The adaptive dynamic compensation layer is capable of updating the estimated parameters for all robots, which are directly related to physical parameters of each mobile manipulator. Also, the redundancy of the mobile manipulators is used for the avoidance of obstacles by the mobile platforms - without deforming the virtual structure and maintaining its desired trajectory - and the singular configuration prevention through the systems manipulability control. Stability and robustness are proved by using Lyapunovs method. Simulation results show a good performance of the proposed multi-layer scheme as proved by the theoretical design.

Adaptive control with redundancy resolution of mobile manipulators

This paper presents an adaptive robust tracking control method for a mobile manipulator during trajectory tracking. The parameters of the mobile manipulator dynamics are updated online. The design of the controller is based on two cascaded subsystems: a minimum norm kinematic controller with command saturation, and an adaptive controller that compensates the dynamics of the mobile manipulator system. Robot commands are defined in terms of reference velocities. Stability and robustness are proved by using Lyapunovs method. Experimental results show a good performance of the proposed controller as proved by the theoretical design.

Adaptive Coordinated Cooperative Control of Multi-Mobile Manipulators

A coordinated group of robots can execute certain tasks, e.g. surveillance of large areas (Hougen et al., 2000), search and rescue (Jennings et al., 1997), and large objectstransportation (Stouten and De Graaf, 2004), more efficiently than a single specialized robot (Cao et al., 1997). Other tasks are simply not accomplishable by a single mobile robot, demanding a group of coordinated robots to perform it, like the problem of sensors and actuators positioning (Bicchi et al., 2008), and the entrapment/escorting mission (Antonelli et al., 2008). In such context, the term formation control arises, which can be defined as the problem of controlling the relative postures of the robots of a platoon that moves as a single structure (Consolini et al., 2007).