Feel lonely? What about reading books? Book is one of the greatest friends to accompany while in your lonely time. When you have no friends and activities somewhere and sometimes, reading book can be a great choice. This is not only for spending the time, it will increase the knowledge. Of course the b=benefits to take will relate to what kind of book that you are reading. And now, we will concern you to try reading modelling and control of robot manipulators as one of the reading material to finish quickly.

Modelling and Control of Robot Manipulators

Underwater manipulators: a review

Underwater Robots: Motion and Force Control of Vehicle-Manipulator Systems

This paper aims to integrate didactically some engineering concepts to understand and teach the screw-based methods applied to the kinematic modeling of robot manipulators, including a comparative analysis between these and the Denavit-Hartenberg-based methods. In robot analysis, kinematics is a fundamental concept to understand, since most robotic mechanisms are essentially designed for motion. The kinematic modeling of a robot manipulator describes the relationship between the links and joints that compose its kinematic chain. To do so, the most popular methods use the Denavit-Hartenberg convention or its variations, presented by several author and robot publications. This uses a minimal parameter representation of the kinematic chain, but has some limitations. The successive screw displacements method is an alternative representation to this classic approach. Although it uses a non-minimal parameter representation, this screw-based method has some advantages over Denavit-Hartenberg. Both methods are here presented and compared, concerning direct/inverse kinematics of manipulators. The differential kinematics is also discussed. Examples of kinematic modeling using both methods are presented in order to ease their comparison.

A comparison between the Denavit-Hartenberg and the screw-based methods used in kinematic modeling of robot manipulators

This exciting new reference text is concerned with fluid power control. It is an ideal reference for the practicing engineer and a textbook for advanced courses in fluid power control. In applications in which large forces and/or torques are required, often with a fast response time, oil-hydraulic control systems are essential. They excel in environmentally difficult applications because the drive part can be designed with no electrical components and they almost always have a more competitive power/weight ratio compared to electrically actuated systems. Fluid power systems have the capability to control several parameters, such as pressure, speed, position, and so on, to a high degree of accuracy at high power levels. In practice there are many exciting challenges facing the fluid power engineer, who now must preferably have a broad skill set.

/pdf/fundamentals-of-fluid-power-control-23c5jqv8a0.pdf

Fundamentals of Fluid Power Control

This paper proposes a cascade controller with friction compensation based on the LuGre model. This control is applied to a pneumatic positioning system. The cascade methodology consists of dividing the pneumatic positioning system model into two subsystems: a mechanical subsystem and a pneumatic subsystem. This division allows the introduction of friction compensation at force level in the pneumatic positioning system. Using Lyapunov´s direct method, the convergence of the tracking errors is shown under the assumption that the system parameters are known. Experimental results illustrate the main characteristics of the proposed controller. Keywords : Servopneumatics, robotics, cascade control, friction compensation

/pdf/cascade-controlled-pneumatic-positioning-system-with-lugre-1odsxsmwby.pdf

Cascade controlled pneumatic positioning system with LuGre model based friction compensation

This work presents a cascade controller for the trajectory tracking control of a hydraulic actuator by using adaptive algorithms to deal with parametric uncertainties together with an adaptive dead-zone compensation scheme. The hydraulic actuator is modeled as a forth order nonlinear system including the valve dynamic as a first order linear system and considering a valve with a dead-zone. Some hydraulic actuator parameters are difficult to be determined or measured, leading to the necessity of considering parametric uncertaities in the design process. Furthermore, the valve dead-zone causes trajectory tracking errors. In the cascade strategy, the hydraulic actuator mathematical model is interpreted as a mechanical subsystem (mass and damper) driven by a hydraulic one (valve and cylinder). From this interpretation, one uses a cascade controller by combining two different adaptive control laws for each subsystem and an adaptive algorithm to compensate the dead-zone. Simulation results illustrate the main characteristics of the proposed controller.

https://www.abcm.org.br/anais/cobem/2005/PDF/COBEM2005-2559.pdf

Adaptive cascade control of a hydraulic actuator with an adaptive dead-zone compensation

This paper presents a new approach to calculate the direct and inverse differential kinematics for serial manipulators. The approach is an extension of the Davies method for open kinematic chains based on a virtual kinematic chain concept introduced in this paper. It is a systematic method that unifies the kinematics of serial manipulators considering the type of kinematics and the coordinate system of the operational space and constitutes an alternative way to solve the differential kinematics for manipulators. The usefulness of the method is illustrated by applying it to an industrial robot.

Differential kinematics of serial manipulators using virtual chains

This paper addresses the kinematics of the Underwater Vehicle-Manipulator Systems (UVMSs). Due the adittional degrees of freedom (dofs) provided by the vehicle, such systems are kinematically redundant, i.e. they possess more dofs than those required to execute a given task, and need to be solved using some redundancy technique. We present an approach based on introducing kinematic constraints. The approach uses the screw representation of movement and is based on the so-called Davies method used to solve the kinematics of closed kinematic chains. We describe the vehicle-manipulator system as an open-loop chain and present a virtual kinematic chain concept that allows closing this open chain. Applying the Davies method to this resulting closed chain, the UVMS direct kinematic is solved. The inverse kinematics is obtained using the same approach, by introducing extra constraints derived from energy savings requirements. The proposed approach is compared to another redundancy resolution method to illustrate the ability of the proposed strategy.

/pdf/virtual-kinematic-chains-to-solve-the-underwater-vehicle-3i6au6pacs.pdf

Virtual kinematic chains to solve the underwater vehicle-manipulator systems redundancy

This paper describes a numerical algorithm to solve the inverse kinematics of parallel robots based on numerical integration. Inverse kinematics algorithms based on numerical integration involve the drift phenomena of the solution; as a consequence, errors are generated when the end-effector location differs from that desired. The proposed algorithm associates a novel method to describe the differential kinematics with a simple numerical integration method. The methodology is presented in this paper and its exponential stability is proved. A numerical example and a real application are presented to outline its advantages.

Raul Guenther

Papers

Cascade controlled pneumatic positioning system with LuGre model based friction compensation

Adaptive cascade control of a hydraulic actuator with an adaptive dead-zone compensation

Differential kinematics of serial manipulators using virtual chains

Virtual kinematic chains to solve the underwater vehicle-manipulator systems redundancy

A new method to solve robot inverse kinematics using assur virtual chains