The Combined Force/Position Control Systems for Manipulators

2008 ◽  
Author(s):  
Vladimir F. Filaretov ◽  
Alexandr V. Zuev
Keyword(s):  
Control Systems ◽  
Degrees Of Freedom ◽  
Position Control ◽  
Robot Manipulators ◽  
Synthesis Method ◽  
End Effector ◽  
New Synthesis ◽  
Force Moment

In this paper, a new synthesis method of force/position control systems of robot manipulators is proposed. The control systems synthesized on the basis of this method without using force/moment sensors and other additional devices provide simultaneous dynamically accurate control of both the position of robot’s end-effector and the force (may be variable) exerted by end-effector on surfaces (object of work) along which it moves. The results of simulation of the manipulator with 3 degrees of freedom are presented. They confirm efficiency of the proposed method. Realization of synthesised control systems does not have large difficulties. These control systems can be realized with the help of a serial microprocessors.

Aerial Contact Manipulation With Soft End-Effector Compliance and Inverse Kinematic Compensation

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Xinjun Sheng ◽  
Zhao Ma ◽  
Ningbin Zhang ◽  
Wei Dong
Keyword(s):  
Degrees Of Freedom ◽  
Position Control ◽  
Mechanical Design ◽  
Impact Resistance ◽  
High Strength ◽  
Inverse Kinematic ◽  
End Effector ◽  
Precise Position ◽  
Positioning Errors ◽  
Aerial Platform

Abstract This paper presents the development of a six degrees-of-freedom manipulator with soft end-effector and an inverse kinematic compensator for aerial contact manipulation. Realizing the fact that aerial manipulators can hardly achieve precise position control, a compliant manipulator with soft end-effector is first developed to moderate end-effector positioning errors. The manipulator is designed to be rigid-soft combined. The rigid robotic arm employs the lightweight but high-strength materials. The compliance requirement is achieved by the soft end-effector so that the mechanical design for the joints are largely simplified. These two features are beneficial to lighten the arm and to ensure the accuracy. In the meantime, the pneumatic soft end-effector can further moderate the probable insufficient accuracy by endowing the manipulator with compliance for impact resistance and robustness to positioning errors. With the well-designed manipulator, an inverse kinematic compensator is then proposed to eliminate lumped disturbances from the aerial platform. The compensator can ensure the stabilization of the end-effector by using state estimation from the aerial platform, which is robust and portable as the movement of the platform can be reliably obtained. Both the accuracy and compliance have been well demonstrated after being integrated into a hexarotor platform, and a representative scenario aerial task repairing the wind turbine blade-coating was completed successfully, showing the potential to accomplish complex aerial manipulation tasks.

Analytic Geometric Design of Spatial R-R Robot Manipulators

2000 ◽  
Author(s):  
Constantinos Mavroidis ◽  
Munshi Alam ◽  
Eric Lee
Keyword(s):  
Degrees Of Freedom ◽  
Robot Manipulators ◽  
Open Loop ◽  
Geometric Design ◽  
Sixth Order ◽  
Design Parameters ◽  
End Effector ◽  
Revolute Joints ◽  
Order Polynomial ◽  
Spatial Locations

Abstract This paper studies the geometric design of spatial two degrees of freedom, open loop robot manipulators with revolute joints that perform tasks, which require the positioning of the end-effector in three spatial locations. This research is important in situations where a robotic manipulator or mechanism with a small number of joint degrees of freedom is designed to perform higher degree of freedom end-effector tasks. The loop-closure geometric equations provide eighteen design equations in eighteen unknowns. Polynomial Elimination techniques are used to solve these equations and obtain the manipulator Denavit and Hartenberg parameters. A sixth order polynomial is obtained in one of the design parameters. Only two of the six roots of the polynomial are real and they correspond to two different robot manipulators that can reach the desired end-effector poses.

A New Polynomial Solution to the Geometric Design Problem of Spatial R-R Robot Manipulators Using the Denavit and Hartenberg Parameters

1999 ◽  
Vol 123 (1) ◽  
pp. 58-67 ◽  
Author(s):  
Constantinos Mavroidis ◽  
Eric Lee ◽  
Munshi Alam
Keyword(s):  
Design Problem ◽  
Degrees Of Freedom ◽  
Robot Manipulators ◽  
Polynomial Solution ◽  
Open Loop ◽  
Geometric Design ◽  
New Method ◽  
Design Parameters ◽  
End Effector ◽  
Spatial Locations

This paper presents a new method to solve the geometric design problem of spatial two degrees of freedom, open loop robot manipulators with revolute joints that perform tasks, which require the positioning of the end-effector in three spatial locations. Tsai and Roth [3] solved this problem first using screw parameters to describe the kinematic topology of the R-R manipulator and screw displacements to obtain the design equations. The new method, which is developed in this paper, uses Denavit and Hartenberg parameters and 4×4 homogeneous matrices to formulate and obtain the kinematic equations. The loop-closure geometric equations provide eighteen design equations in eighteen unknowns. Polynomial Elimination techniques are used to solve these equations and obtain the manipulator Denavit and Hartenberg parameters and the manipulator base and end-effector geometric parameters. A sixth order polynomial is obtained in one of the design parameters. Only two of the six roots of the polynomial are real and they correspond to two different robot manipulators that can reach the desired end-effector poses.

scholarly journals Nonlinear pd controllers with gravity compensation for robot manipulators

2014 ◽  
Vol 14 (1) ◽  
pp. 141-150 ◽  
Author(s):  
Jianfeng Huang ◽  
Chengying Yang ◽  
Jun Ye
Keyword(s):  
Degrees Of Freedom ◽  
Position Control ◽  
Robot Manipulator ◽  
Robot Manipulators ◽  
Nonlinear Function ◽  
Step Response ◽  
Robot Dynamics ◽  
Gravity Compensation ◽  
Pd Controller ◽  
Globally Asymptotically Stable

Abstract A Nonlinear Proportional-Derivative (NPD) controller with gravity compensation is proposed and applied to robot manipulators in this paper. The proportional and derivative gains are changed by the nonlinear function of errors in the NPD controller. The closed-loop system, composed of nonlinear robot dynamics and NPD controllers, is globally asymptotically stable in position control of robot manipulators. The comparison of the simulation experiments in the position control (the step response) of a robot manipulator with two degrees of freedom is also presented to illustrate that the NPD controller is superior to the conventional PD controller in a position control system. The experimental results show that the NPD controller can obtain a faster response velocity and higher position accuracy than the conventional PD controller in the position control of robot manipulators because the proportional and derivative gains of the NPD controller can be changed by the nonlinear function of errors. The NPD controller provides a novel approach for robot control systems.

Learning control of robot manipulators by interactive simulation

Robotica ◽  
2005 ◽  
Vol 23 (4) ◽  
pp. 515-520 ◽  
Author(s):  
Rafael Kelly ◽  
Sebastian Dormido ◽  
Carmen Monroy ◽  
Elizabeth Díaz
Keyword(s):  
Control Systems ◽  
Position Control ◽  
Graphical Representation ◽  
Robot Manipulators ◽  
Robot Dynamics ◽  
Interactive Simulation ◽  
Robot Arm ◽  
Control Structures ◽  
Dynamics And Control ◽  
And Control

Control systems of robot manipulators offer many challenges in education where the students must learn robot dynamics and control structures, and understand relations between the control parameters and the systems performance. Interactive simulation is aimed at improving the understanding of and intuition for the abstract parts of the control of robot courses. This paper presents an application of interactive simulation to teach control systems of robots. The application considers a nonlinear robot arm and two control modules: position control and motion control. Students can directly manipulate graphical representation of the systems such as a choice among seven control structures, controller gains, and desired trajectories, and obtain instant feedback on the effects. These features make the interactive learning tool stimulating and of high pedagogical value.

Hybrid Force-Position Control Three Fingers End Effector

2013 ◽  
Vol 346 ◽  
pp. 75-82
Author(s):  
Vladimir Prada Jiménez ◽  
Oscar Fernando Avilés Sánchez ◽  
Mauricio M. Mauledoux
Keyword(s):  
Degrees Of Freedom ◽  
Position Control ◽  
Kinematics And Dynamics ◽  
End Effector ◽  
Matlab Simulink ◽  
Two Degrees Of Freedom ◽  
Hybrid Controller

This paper describes the implementation of a hybrid controller to an end effector of threefingers, each finger with two degrees of freedom (2 DOF). Since the mobility of each phalanx showsthe workspace by finger. Modeling is presented which includes the kinematics and dynamics offector and implementation of force-position hybrid controller. Simulations are presented to validatethe behavior of the finger and the controller in Matlab Simulink.

Topological and Geometrical Synthesis of Three-Degree-of-Freedom Fully Parallel Manipulators by Instantaneous Kinematics

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Xiaoyu Wang ◽  
Luc Baron ◽  
Guy Cloutier
Keyword(s):  
Degrees Of Freedom ◽  
Parallel Manipulators ◽  
Synthesis Process ◽  
End Effector ◽  
Numerical Examples ◽  
Passive Joint ◽  
New Synthesis ◽  
Synthesis Procedure ◽  
Three Degree Of Freedom ◽  
Three Degrees Of Freedom

This paper presents a new synthesis procedure of fully parallel manipulators (PMs) of three degrees of freedom (DOFs) that could be implemented in a computer-aided synthesis process. Possible designs of PMs are represented by a set of unit joint twists at an initial configuration, called here topological and geometric parameters (TGPs). This makes it possible to represent PMs of all topologies and geometries in an easy and consistent way. The kinematic bond between the end effector (EE) and the base is then formulated as a set of equations involving TGPs, actuated-joint variables, and non-actuated-joint variables (passive joints). To achieve the required type of EE motion, possible topologies are first derived from tangent space analysis, and then the feasible topologies are retained by further displacement analysis. The geometries are determined such that the set of equations should be isoconstrained when passive-joint variables are taken as unknowns. The synthesis procedure of 3DOF PMs is illustrated with three numerical examples: one producing a new architecture of one translation and two rotations, while the other two producing existing architectures of translational PMs.

scholarly journals Research for a novel class of translational spatial multi-loop coupled mechanisms: Type synthesis and kinematic analysis

2018 ◽  
Vol 10 (8) ◽  
pp. 168781401879702 ◽  
Author(s):  
Shuang Zhang ◽  
Jingfang Liu ◽  
Huafeng Ding
Keyword(s):  
Kinematic Analysis ◽  
Degrees Of Freedom ◽  
Synthesis Method ◽  
Future Application ◽  
The Novel ◽  
Parallel Mechanisms ◽  
Type Synthesis ◽  
Split Method ◽  
New Synthesis ◽  
The Family

A novel type synthesis method for a class of spatial multi-loop coupled mechanisms with translational degrees of freedom is proposed in the paper. The novel class of spatial multi-loop coupled mechanisms has a stable topology layout which consists of three branches and three coupled chains. The basic idea of the new structural synthesis method lies at replacing the inputs of one mechanism by the outputs of another, thereby combining several mechanisms, where the topology split method for the topological layout and corresponding degree of freedom splitting principle are provided. The synthesis of the target mechanism is transformed into synthesis of corresponding serial and parallel mechanisms thereby, and a class of spatial multi-loop coupled mechanisms is synthesized. To validate the new synthesis method and to present a theoretical basis for future application, kinematic analysis of a single translational mobility (1T) spatial multi-loop coupled mechanism and a symmetrical two translational degrees of freedom (2T) spatial multi-loop coupled mechanism is performed. This article enriches the family of the spatial mechanisms for further instructing the study of spatial multi-loop coupled mechanisms.

On Model Feedback Control for Robot Manipulators

1991 ◽  
Vol 113 (3) ◽  
pp. 371-378 ◽  
Author(s):  
T. Narikiyo ◽  
T. Izumi
Keyword(s):  
Control Systems ◽  
Degrees Of Freedom ◽  
Robot Manipulators ◽  
Control Design ◽  
Parameter Uncertainties ◽  
Uncertain Dynamics ◽  
Classical Control ◽  
Multivariate Control ◽  
Control Methodology ◽  
Three Degrees Of Freedom

Robot manipulators are highly coupled nonlinear systems and their motions are influenced by uncertain dynamics such as coulomb friction. These nonlinearities and uncertainties disturb the performance of control systems. In this paper, a control design methodolgy is proposed for the purpose of reducing the adverse effects of parameter uncertainties and disturbances. This control structure is similar to that of classical control. Unlike classical control, this control methodology accommodates multivariate control systems with uncertain dynamics and disturbances. The control design methodology is applied to a three-degrees-of-freedom directly driven robot. Simulation and experimental results demonstrate excellent robustness.

scholarly journals Iterative Learning Control Based on Sliding Mode Technique for Hybrid Force/Position Control of Robot Manipulators

2021 ◽  
Author(s):  
Xinxin Zhang ◽  
Huafeng Ding ◽  
Min Li ◽  
Andrés Kecskeméthy
Keyword(s):  
Iterative Learning Control ◽  
Degrees Of Freedom ◽  
Position Control ◽  
Sliding Mode ◽  
Robot Manipulators ◽  
Learning Control ◽  
Iterative Learning ◽  
Planar Parallel Manipulator ◽  
Mode Technique ◽  
Sliding Mode Technique

Abstract In this paper, an iterative learning control (ILC) method based on sliding mode technique is proposed for hybrid force/position control of robot manipulators. Different from traditional ILC, the main purpose of the proposed ILC is to learn the dynamic parameters rather than the control signals. The sliding mode technique is applied to enhance the robustness of the proposed ILC method against external disturbances and noise. The switching gain of the sliding mode term is time-varying and learned by ILC such that the chattering is suppressed effectively compared to traditional sliding mode control (SMC). Simulation studies are performed on a two degrees of freedom planar parallel manipulator. Simulation results demonstrate that the proposed method can achieve higher force/position tracking performance than the traditional SMC and ILC.

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