scholarly journals Cartesian Aerial Manipulator with Compliant Arm

2021 ◽  
Vol 11 (3) ◽  
pp. 1001
Author(s):  
Alejandro Suarez ◽  
Manuel Perez ◽  
Guillermo Heredia ◽  
Anibal Ollero
Keyword(s):  
Dynamic Models ◽  
Position Control ◽  
Force Sensor ◽  
Monitoring And Control ◽  
End Effector ◽  
Robotic Arms ◽  
Revolute Joints ◽  
Angular Deflection ◽  
Compliant Joint ◽  
And Control

This paper presents an aerial manipulation robot consisting of a hexa-rotor equipped with a 2-DOF (degree of freedom) Cartesian base (XY–axes) that supports a 1-DOF compliant joint arm that integrates a gripper and an elastic linear force sensor. The proposed kinematic configuration improves the positioning accuracy of the end effector with respect to robotic arms with revolute joints, where each coordinate of the Cartesian position depends on all the joint angles. The Cartesian base reduces the inertia of the manipulator and the energy consumption since it does not need to lift its own weight. Consequently, the required torque is lower and, thus, the weight of the actuators. The linear and angular deflection sensors of the arm allow the estimation, monitoring and control of the interaction wrenches exerted in two axes (XZ) at the end effector. The kinematic and dynamic models are derived and compared with respect to a revolute-joint arm, proposing a force-position control scheme for the aerial robot. A battery counterweight mechanism is also incorporated in the X–axis linear guide to partially compensate for the motion of the manipulator. Experimental results indoors and outdoors show the performance of the robot, including object grasping and retrieval, contact force control, and force monitoring in grabbing situations.

Redundancy utilization for obstacle avoidance of planar robot manipulators

1997 ◽  
Vol 211 (6) ◽  
pp. 463-475 ◽  
Author(s):  
U Sezgin ◽  
L D Seneviratne ◽  
S W E Earles
Keyword(s):  
Obstacle Avoidance ◽  
Computer Simulations ◽  
Redundant Manipulators ◽  
Control Points ◽  
Kinematic Redundancy ◽  
End Effector ◽  
Revolute Joints ◽  
Planar Robot ◽  
And Control ◽  
Configuration Control

Two obstacle avoidance criteria are developed, utilizing the kinematic redundancy of serial redundant manipulators having revolute joints and tracking pre-determined end effector paths. The first criterion is based on the instantaneous distances between certain selected points along the manipulator, called configuration control points (CCP), and the vertices of the obstacles. The optimized joint configurations are obtained by maximizing these distances. Thus, the links of the manipulator are configured away from the obstacles. The second criterion uses a different approach, and is based on Voronoi boundaries representing the equidistant paths between two obstacles. The optimized joint configurations are obtained by minimizing the distances between the CCP and control points selected on the Voronoi boundaries. The validities of the criteria are demonstrated through computer simulations.

Experimental Research on Force/Position Control of a Wire-Driven Parallel Rehabilitative Robot

2011 ◽  
Vol 138-139 ◽  
pp. 68-73 ◽  
Author(s):  
Ke Yi Wang ◽  
Fang Chao Ma ◽  
Meng Hao ◽  
Li Xun Zhang ◽  
Pan Liu
Keyword(s):  
Position Control ◽  
Parallel Robot ◽  
Force Balance ◽  
Robot System ◽  
End Effector ◽  
Wire Tension ◽  
Parallel Control ◽  
The Wire ◽  
And Control ◽  
Force Balance Equation

During rehabilitative training, a 3-DOF wire-driven parallel robot driven was designed to coordinate and control the trainer pelvis movement. Based on the force balance equation of the end-effector, the stiffness problem about the robot system was analyzed and one kind of force/position parallel control strategy was proposed that the position loop would realize the end-effector motion trajectory, and the force loop would control the wire tension. The experimental results have shown that the robot systematic stiffness is related with the wire tension and can be changed to realize the compliance control of the robot system by adjusting the wire tension.

Comparing model-based control methods for simultaneous stiffness and position control of inflatable soft robots

2020 ◽  
pp. 027836492091196
Author(s):  
Charles M. Best ◽  
Levi Rupert ◽  
Marc D. Killpack
Keyword(s):  
Dynamic Models ◽  
Position Control ◽  
Sliding Mode ◽  
Joint Stiffness ◽  
Variable Stiffness ◽  
Soft Robots ◽  
End Effector ◽  
Simultaneous Control ◽  
Stiffness Model ◽  
Stiffness Control

Inflatable robots are naturally lightweight and compliant, which may make them well suited for operating in unstructured environments or in close proximity to people. The inflatable joints used in this article consist of a strong fabric exterior that constrains two opposing compliant air bladders that generate torque (unlike McKibben actuators where pressure changes cause translation). This antagonistic structure allows the simultaneous control of position and stiffness. However, dynamic models of soft robots that allow variable stiffness control have not been well developed. In this work, a model that includes stiffness as a state variable is developed and validated. Using the stiffness model, a sliding mode controller and model predictive controller are developed to control stiffness and position simultaneously. For sliding mode control (SMC), the joint stiffness was controlled to within 0.07 Nm/rad of a 45 Nm/rad command. For model predictive control (MPC) the joint stiffness was controlled to within 0.045 Nm/rad of the same stiffness command. Both SMC and MPC were able to control to within 0.5° of a desired position at steady state. Stiffness control was extended to a multiple-degree-of-freedom soft robot using MPC. Controlling stiffness of a 4-DOF arm reduced the end-effector deflection by approximately 50% (from 17.9 to 12.2cm) with a 4 lb (1.8 kg) step input applied at the end effector when higher joint stiffness (40 Nm/rad) was used compared with low stiffness (30 Nm/rad). This work shows that the derived stiffness model can enable effective position and stiffness control.

Modular CNC Design for Intelligent Machining, Part 2: Modular Integration of Sensor Based Milling Process Monitoring and Control Tasks

1996 ◽  
Vol 118 (4) ◽  
pp. 514-521 ◽  
Author(s):  
Y. Altintas¸ ◽  
W. K. Munasinghe
Keyword(s):  
Process Control ◽  
Real Time ◽  
Process Monitoring ◽  
Tool Path ◽  
Position Control ◽  
Milling Process ◽  
Machining Process ◽  
Monitoring And Control ◽  
Process Monitoring And Control ◽  
And Control

Modular integration of sensor based milling process monitoring and control functions to a proposed CNC system architecture is presented. Each sensor based process control algorithm resides in a dedicated processor in the AT bus with a modular software. The CNC system’s motion control module has been designed to accomodate rapid manipulation of feeds, cutting conditions and NC tool path which may be demanded by machining process control modules in real time. Modular integration of adaptive control of cutting forces, tool condition monitoring, chatter detection and suppression tasks are illustrated as examples. The process control and monitoring modules are serviced in the real-time multi-tasking environment within one millisecond time intervals without disturbing the position control system. The paper present constraints and guidelines in designing CNC systems which allow modular integration of user developed real time machining process control and monitoring applications.

scholarly journals Position and Singularity Analysis of a Class of Planar Parallel Manipulators with a Reconfigurable End-Effector

Machines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 7
Author(s):  
Tommaso Marchi ◽  
Giovanni Mottola ◽  
Josep M. Porta ◽  
Federico Thomas ◽  
Marco Carricato
Keyword(s):  
Inverse Kinematics ◽  
Kinematic Chain ◽  
Experimental Tests ◽  
Parallel Manipulators ◽  
Singularity Analysis ◽  
Parallel Robots ◽  
End Effector ◽  
Revolute Joints ◽  
A Chain ◽  
And Control

Parallel robots with configurable platforms are a class of robots in which the end-effector has an inner mobility, so that its overall shape can be reconfigured: in most cases, the end-effector is thus a closed-loop kinematic chain composed of rigid links. These robots have a greater flexibility in their motion and control with respect to rigid-platform parallel architectures, but their kinematics is more challenging to analyze. In our work, we consider n-RRR planar configurable robots, in which the end-effector is a chain composed of n links and revolute joints, and is controlled by n rotary actuators located on the base of the mechanism. In particular, we study the geometrical design of such robots and their direct and inverse kinematics for n=4, n=5 and n=6; we employ the bilateration method, which can simplify the kinematic analysis and allows us to generalize the approach and the results obtained for the 3-RRR mechanism to n-RRR robots (with n>3). Then, we study the singularity configurations of these robot architectures. Finally, we present the results from experimental tests that have been performed on a 5–RRR robot prototype.

scholarly journals PLATAFORMA DE BRAZOS ROBÓTICOS DE TECNOLOGÍA ABIERTA PARA REALIZAR EXPERIENCIAS DE LABORATORIO DE CONTROL DE POSICIÓN, PLANIFICACIÓN DE TRAYECTORIA Y CONTROL DE VISIÓN ARTIFICIAL

2016 ◽  
Vol 26 (1) ◽  
pp. 101
Author(s):  
Mario Borja Borja ◽  
Javier Rojas Tintaya ◽  
Rodney Rodas Regalado ◽  
Carlos Díaz Ramirez ◽  
Cesar Paz Chavez Cesar Paz Chavez
Keyword(s):  
Control System ◽  
Path Planning ◽  
Degrees Of Freedom ◽  
Position Control ◽  
Digital Signal ◽  
Artificial Vision ◽  
Robotic Arms ◽  
Technology Platform ◽  
Planning And Control ◽  
And Control

RESUMEN El principal problema en el desarrollo de carreras de especialización en robótica en nuestro país es que no existen laboratorios con brazos robóticos que permitan hacer pruebas de control de posicionamiento, planificación de trayectoria y control con visión artificial y generalmente en entornos académicos se hace experimentos utilizando software de simulación.En el presente trabajo se propone una alternativa para mejorar el aprendizaje en el estudio de control de brazos robóticos utilizando brazos robóticos reales con una plataforma de tecnología abierta de software y hardware que permita a los estudiantes modificar los programas para implementar algoritmos de control de posición de articulaciones, planificación de trayectoria y control con visión artificial.La propuesta es desarrollar la tecnología total del sistema de control del brazos robóticos en la base al análisis de los requerimientos de electrónica y sistema de computo realizar la selección de electrónica de potencia, computadoras industriales basadas en Controlador Digital de señales (DSC), una computadora personal para interface de usuario.Desarrollar el software base para la computadora industrial y el software base para la computadora personal que permita cargar programas en línea a través del puerto serial desde una computadora personal y además una interface de usuario en la computadora que puede ser modificada de acuerdo a la necesidad y utilizar como sistema de control de nivel superior que realiza los cálculos de planificación de trayectoria, problema inverso y otros sistemas de alto nivel de control con visión artificial.Como resultado se obtuvo la plataforma de tecnología abierta que incluye hardware y software para brazos robóticos de hasta seis grados de libertad con motores de corriente continua en las articulaciones de hasta 100 vatios, encoders y sensores de fin de carrera.La plataforma se probó con la mecánica del brazo robótico serial Mitsubishi RV-M1 que cumple con los parámetros electrónicos y constructivos requeridos por el prototipo.Palabras claves: brazos robóticos; control de posición; plataforma abierta.ABSTRACT The main problem in the development of specialization courses in robotics in our country is that there are no laboratories with robotic arms that allow testing positioning control, path planning and control with artificial vision and generally in academic settings is done experiments using software simulation.In this paper an alternative to enhance learning in the study control robotic arms using real robotic arms with an open technology platform software and hardware that allows students to modify programs to implement control algorithms position it is proposed joints, path planning and control with artificial vision.The proposal is to develop the full technology control system of the robotic arms on the basis of the analysis of the requirements of electronic and computer system the selection of power electronics, industrial computers based on digital signal controller (DSC), a computer personnel to user interface.Develop the core software for industrial computer and basic software for the PC that allows load programs online through the serial port from a personal computer and also a user interface on the computer that can be modified according to the need and used as control system upper level that performs calculations path planning, inverse problem and other high-level systems with artificial vision control.As a result the open technology platform that includes hardware and software for robotic arms up to six degrees of freedom with DC motors in the joints of up to 100 watts, encoders and sensors to run was obtained. The platform was tested with the mechanics of serial robotic arm Mitsubishi RV-M1 compliant electronic and construction parameters required by the prototype.Keywords: robotic arms; position control; open platform.

Development of a Novel Two-Axis Force Sensor for Chinese Massage Robot

2011 ◽  
Vol 103 ◽  
pp. 299-304 ◽  
Author(s):  
Jun Qing Ma ◽  
Ai Guo Song
Keyword(s):  
Bridge Circuit ◽  
Force Sensor ◽  
Static Characteristic ◽  
Strain Gauges ◽  
Element Analysis ◽  
End Effector ◽  
Static Calibration ◽  
And Control ◽  
Interference Error ◽  
Decoupling Algorithm

In order to judge and control applied force of Chinese massage robot’s end-effector on human body accurately, multi-dimensional interactive forces between massage robot’s end-effector and human should be measured. In this paper, a novel two-axis force sensor suitable for massage robot’s end-effector is presented, which is much smaller than existing sensors but in the same range measurement. Mechanical structure is introduced, theoretical analysis of elastic body is made, and finite element analysis is used to analyze its static characteristic. Then, the distribution of strain gauges and design of Hilton Bridge Circuit are described in detail. Finally, a prototype is fabricated. Decoupling algorithm is designed to reduce the interference error. The result of static calibration experimental data shows that the sensor has features of high precision and sensitivity.

scholarly journals Integración y gestión por computadora de sistema automatizado para la ejecución de tarea de pintado

2020 ◽  
pp. 14-20
Author(s):  
Martín Eduardo RODRÍGUEZ-FRANCO ◽  
Diego César CARREÓN-MÁRQUEZ ◽  
José Alberto RODRÍGUEZ-LOMELÍ ◽  
Néstor David FELICIANO-VELÁZQUEZ
Keyword(s):  
Practical Knowledge ◽  
Vision System ◽  
Computer Interface ◽  
Regulation System ◽  
Monitoring And Control ◽  
Entire Surface ◽  
End Effector ◽  
Labview Software ◽  
And Control ◽  
Positive Results

This paper exposes the implementation of a robot in angular configuration for the performance of surface painting task, since the conditioning of a spraying tool in its end effector. Robot monitoring and control are executed by integrating a joint regulation system, based on the corresponding kinematic resolution, in communication with a computer interface, developed from LabVIEW software. A finished product inspection operation is contemplated, whose function is performed by a vision system added to the same management interface. The proposal of a trajectory in the end effector that imitates the external shape of the object to be painted in combination with the rotation control of a rotating table, on which such object remains during the process, has allowed to describe a minimum quantity of executions of the painted sequence to cover its entire surface; showing positive results. It is concluded in the convenience of this implementation with industrial orientation, by combining theoretical and practical knowledge essential in Engineering.

Development of Sensorless Force-Control-Based End-Effector for Automated Robot Polishing

2020 ◽  
Author(s):  
Takuhiro Tsukada ◽  
Shotaro Ogawa ◽  
Katsuki Koto ◽  
Yasuhiro Kakinuma
Keyword(s):  
Force Control ◽  
High Performance ◽  
Force Sensor ◽  
Pressure Control ◽  
Industrial Robots ◽  
End Effector ◽  
Finishing Process ◽  
Polishing Force ◽  
Articulated Robot ◽  
And Control

Abstract As the finishing process in manufacturing a fine mold, manual polishing is typically performed to enhance the surface quality. On the other hand, manual polishing causes increase in costs and health damage to the workers due to sucking polishing dusts. Hence, polishing automation is strongly required by utilizing industrial robots. Regarding robot polishing, highly responsive polishing pressure control is definitely needed so that macro-micro system integrating high-performance end-effector into the articulated robot could be an appropriate approach because response of the robot itself is not sufficiently high. From this viewpoint, the purpose of this study is to develop an end-effector having the ability to simultaneously control polishing force and tool spindle speed. The mechanism and control system of the end-effector are designed and experimentally evaluated. In terms of force control, observer-based force control, which does not require any additional force sensor, is implemented. The experimental results show that the developed end-effector successfully control polishing force with 0.1 N and bandwidth up to 23 Hz.

Modelling and Control of a Mobile Robot, Equipped with an Arm in Cylindrical Coordinates with Uncoupled Tentacular Terminal

2016 ◽  
Vol 822 ◽  
pp. 311-320
Author(s):  
Viorel Stoian ◽  
Sorin Dumitru
Keyword(s):  
Dynamic Models ◽  
Robotic System ◽  
Mobile Platform ◽  
Robotic Arm ◽  
Target Point ◽  
Cylindrical Coordinates ◽  
Lagrange Method ◽  
End Effector ◽  
Kinematic Models ◽  
And Control

In this paper a robotic system which consists in a mobile platform with wheels and a robotic arm that operates in cylindrical coordinates which are located on, having a tentacular end-effector that executes specific grasping operations is presented. The robotic system executes: the displacement in the operation field, towards a target point that has been priori established, positioning the arm in order to perform the specified task, and the end-effector task according to a tentacular model. Kinematic models are made by Denavit – Hartenberg method and dynamic models by Lagrange method. Finally, is proposed a control system with uncoupled components.Keywords: mobile platform, tentacular structure, observer.

Sign in / Sign up

Export Citation Format

Share Document