Industrial Robot Control Research Articles

Fine-Motion-Control Method for Realizing High-Accuracy and High-Speed Contact Motion of Industrial Robots by Employing Sensorless Force Control

This paper proposes a new fine-motion-control method for realizing high-accuracy and high-speed contact motion of industrial robots by employing sensorless force control. Today, although industrial robots have become considerably important in the modern industrial society, their functions are limited. A typical limited function is the positioning motion control of robots used in the manufacturing industry. Contact motion is necessary for almost all new applications. In this study, by employing the proposed motion control, smooth and quick contact motion of industrial robots is realized by using a sensorless I-P (Integral-Proportional) force feedback controller. The proposed method is simple and effective, takes into account both the inertia of a robot and the behavior of the I-P force controller. In the experiments, a three-degree-of-freedom robot is brought into contact with an object (a concrete block or a rubber board) by the I-P force control using the proposed method. Further, in the experiment, the motion of the robot's end-effector was considered. The validity of the proposed method is confirmed by using a six-axis force sensor and an acceleration sensor in the contact motion experiments.

Force control of redundant industrial robots with an approach for singularity avoidance using extended task space formulation (ETSF)

Abstract This paper presents a robot control system using force control on a redundant industrial robot. The control system is based upon an active force feedback system using six axes force sensor attached to the robot's end effector. The redundancy is used to explore a model for singularity avoidance based on different states of redundancy. The system is implemented and tested experimentally for one of the described states on a NACHI MR20 seven axes robot. The experimental results demonstrate the possibility to control a redundant industrial robot by force control.

2A1-E03 IDCSを用いた柔軟アームを有するロボットの振動制御(フレキシブルロボット・メカニズム)

2A1-E03 IDCSを用いた柔軟アームを有するロボットの振動制御(フレキシブルロボット・メカニズム)

Linear Parameter-Varying Modeling for Gain-Scheduling Robust Control Synthesis of Flexible Joint Industrial Robot

Industrial robot features a multivariable, nonlinear and coupled dynamics property, which is always the inevitable topic for control engineer to face during the design of motion controller to achieve desired performance. In the past half century, motion control of industrial robot has gone through a sustainable development from no model involved to model based, from rigid body model to flexible joint model, and even more delicate models of higher order with flexibility in non-drive-train components are also introduced lately. Involvement of gradually refined dynamic model into control design, as well as manipulator design, has become a dominating approach for robot manufacturer to pursue competitive performance and keep technological leadership. Focusing on dynamic modeling, this paper introduces the formulation and approximation of a novel linear parameter-varying (LPV) model for the three main axes of typical six degrees-of-freedom (DOF) elbow type robot, which converts the strong nonlinear system into a quasi linear one globally dependent on certain scheduling parameters. This modeling method, as the prerequisite step for gain-scheduling robust control synthesis, paves the way for further step towards the implementation of LPV gain-scheduling modeling and control techniques for full robot in the next step.

GA-Based Practical Auto-Tuning Technique for Industrial Robot Controller with System Identification

GA-Based Practical Auto-Tuning Technique for Industrial Robot Controller with System Identification

Design of Dual-Core Architecture Industrial Robot Controller Based on FPGA

This paper designs a dual core structure robot controller, using the resource of FPGA and the method of customizing Nios II dual core processor, which utilizes the openness of SOPC, so that satisfies the requirement of openness and real-time. It designs the software and hardware structure of the controller and carries out relative experiments. The results show that the robot controller system is reasonable and feasible.

On the use of functional redundancy in industrial robotic manipulators for optimal spray painting

AbstractRobotic spray painting is a well-established industrial application usually performed with a 6-axes industrial robot. This task leaves an extra degree of freedom which can be exploited in order to achieve any additional goal. Unfortunately, typical proprietary industrial robotic controllers do not allow the programmer to modify the inverse kinematics algorithm, and thus to solve task redundancy following any specified criterion. In this paper a method to enforce an arbitrary redundancy resolution criterion on top of an industrial robot controller is discussed and applied to the execution of a spray painting task. The extra degree of freedom is used to maximize the manipulability index. Simulations and experimental results achieved on the ABB IRB 140 industrial robot are presented.

Design of a universal robot controller

The paper deals with a general purpose industrial robot controller. Due to the modules of the system is universal. It can be connected to several types of robots, even to CNC, turning-mill or other machines. It was connected to an Adept Scara robot successfully,experimental results will be presented. The basic element of the system is the EMC2 open source robot controller program, which runs in a realtime linux kernel. A PCI card creates the high speed connection between the EMC2 and the machine. DC servo amplifier, digital input and output module, teach pendant, and power electronics designed for the system. The system is RT-middleware (Robotics Technology Middleware)compatible. The RT-middleware is a common robot control platform, which can easily connect different robots to the same network for a common work.

High‐speed and high‐precision position control using a sliding mode compensator

AbstractTo achieve high‐speed, high‐precision position control for semiconductor product machines and industrial robots, full‐closed feedback control is applied. Many control methods have been proposed for such a system. In general, proportional position control and proportional plus integral velocity control or integral plus proportional velocity control (P,PI/I‐P), which is a type of proportional plus integral plus differential control (PID), is applied in many industrial applications. However, in the case of changing mechanical characteristics of the control target, the parameters of P,PI/I‐PI control must also change in order to maintain good motion performance. In this paper, we propose a new P,PI/I‐P control method that includes a nonlinear compensator. The algorithm of the nonlinear compensator is based on sliding mode control with chattering compensation. The effectiveness of the proposed control method is evaluated using a full‐closed single‐axis slider system via point‐to‐point control and contour control in the case of changing load. The experimental results indicate that the proposed control method is robust in the case of changing acceleration/deceleration of control reference, changing load, and low‐velocity contour motion. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 174(2): 65–71, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21011

Fuzzy Self-Tuning Precompensation PD Control with Gravity Compensation of 3 DOF Planar Robot Manipulators

Industrial robot control covers nonlinearity, uncertainty and external perturbation considered in control laws design. Proportional and Derivative (PD) with gravity compensation control is well-known control used in manipulators to ensure global asymptotic stability for fixed symmetrical positive definite gain matrices. To enhance PD with gravity compensation controller performance, in this paper, we propose hybrid fuzzy PD control precompensation with gravity compensation, consisting of a fuzzy logic-based precompensator followed by hybrid fuzzy PD with gravity compensation controller. Hybrid fuzzy control is done by a Supervisory Hierarchical Fuzzy Controller (SHFC) for tuning conventional controller Proportional and Derivative gains based on actual tracking location and velocity error. Hierarchical hybrid fuzzy control consists of an intelligent upper supervisory fuzzy controller and a lower direct conventional PD controller. Numerical simulations using the dynamic model of a three DOF planar rigid robot manipulator with uncertainty show the effectiveness of the approach in trajectory tracking problems. Our results show that the proposal controller has performance superior to a conventional controller.

Open Architecture of Robot Control System Based on PROFI-BUS

A PROFI-BUS based industrial robot control system is introduced from the viewpoint of both software and hardware. It is discussed about how to use PC technology and field-bus technology to design an open robot control system. The system adopts a three- layer structure, which is mainly configured with universal control devices, to realize a modular and universal design. A high-speed field-bus is designed for connecting servo system and IPC, to ensure real-time capability; another low-speed Field-bus is used to connect IPC and PLC, HMI, teaching panel and other devices for data exchange, while reducing the occupancy of system resources. The software system adopts the modular design with Windows NT and RTX, which fully exploits the powerful functions of Window NT system and meets the requirements of real-time system. This open structure greatly enhances the system's flexibility and openness.

Cost-efficient drilling using industrial robots with high-bandwidth force feedback

Here we present a method for high-precision drilling using an industrial robot with high-bandwidth force feedback, which is used for building up pressure to clamp-up an end-effector to the work-piece surface prior to drilling. The focus is to eliminate the sliding movement (skating) of the end-effector during the clamp-up of the end-effector to the work-piece surface, an undesired effect that is due to the comparatively low mechanical stiffness of typical serial industrial robots. This compliance also makes the robot deflect due to the cutting forces, resulting in poor hole position accuracy and to some extent in poor hole quality. Recently, functionality for high-bandwidth force control has found its way into industrial robot control systems. This could potentially open up the possibility for robotic drilling systems with improved performance, using only standard systems without excessive extra hardware and calibration techniques. Instead of automation with expensive fixtures and precise machinery, our approach was to make use of standard low-cost robot equipment in combination with sensor feedback. The resulting sliding suppression control results in greatly improved hole positioning and quality. The conceptual idea behind the force control is useful also in many other robotic applications requiring external sensor feedback control.

Stability analysis of the operational space control for industrial robots using their own joint velocity pi controllers

Operational space control of industrial robots is addressed in this document. We analyze a two-loop hierarchical control with the resolved motion rate controller (RMRC) as outer loop and the joint ...

Stability analysis of the operational space control for industrial robots using their own joint velocity PI controllers

SUMMARYOperational space control of industrial robots is addressed in this document. We analyze a two-loop hierarchical control with the resolved motion rate controller (RMRC) as outer loop and the joint velocity PI controller as inner loop; the latter is the typical velocity controller used in industrial robots. We prove, by the first time, that these simple controllers make the solutions of the closed-loop system uniformly ultimately bounded. Additionally, we give some simple guidelines for the selection of the control gains so as to ensure an explicit bound of the tracking error.

Study on the Dynamics Control of Industrial Robot Modeling Based on Spatial Operator Algebra Theory

In order to improve the modeling efficiency of the industrial robot dynamics control, the recursive dynamics is studied based on the Spatial Operator Algebra (SOA) theory, and the procedure realization is built in the environment of Matahematica6.0 software. The high effective recursive forward and reward dynamics for the SOA theory, has a simple math expression and a clear physical meaning. The software structure of the forward and inverse dynamics is built and the industrial robot dynamics simulation model is realized based on the integrated procedure VB.NET and Mathematica 6.0. According to the analysis, the example of PUMA560 robot forward and inverse dynamics is studied, and correctness and validity is verified by computed examples.

Basketball Robot: Ball-on-Plate System without Visual Information

K. Lee, A. Achhammer, S. Drexler, and D. Wollherr Institute of Automatic Control Engineering,Technische Universitat Munchen , Munich, 80290 Germany(E-mail: k.lee@ieee.org)VIDEO ABSTRACTBuilding a basketball robot is a recently launched projectat the Institute of Automatic Control Engineering (LSR)for investigating fast manipulation with non-negligible dy-namics and changing contact situation. This video presentssome preliminary results of the project which is balancinga basketball on a plate. An aluminium plate of which thesize is 25 40 cm is mounted on the end-e ector of asix degree of freedom (DoF) serial industrial robot StaubliRX90. In order to update the current state of a basketballon the plate the robot is equipped with a 6 DoF force-torque sensor between the plate and the end-e ector. Themass of the basketball is 0 :6 kg.Standard control of industrial robots is inappropriate fortesting complex control algorithms. A possible solutionto create a rapid prototyping test environment is to runthe system with Matlab/Simulink, see Wollherr et al.(2003). Fig. 1 describes the hardware con guration usedin this experiment with an additional PC, on whichMatlab/Simulink is executed under realtime Linux (RTAI)environment. It is integrated with sensoray cards anda force-torque sensor receiver. Advantages of using thishardware con guration are that new control algorithmscan be designed easily in Matlab/Simulink and executed inthe realtime Linux environment while keeping signi cantsafety measures such as motor brakes, supervising jointlimits and speeds as well as emergency brake from theoriginal system.The overall control scheme for the balancing a basket-ball consists of three parts including balancing control,impedance control, and inner position control. When thebasketball loses its equilibrium on the plate and startsmoving, velocity and position of the basketball are esti-mated by force-torque sensor data and the correspondingdesired trajectory for stabilizing the ball is generated inthe balancing control. The inner impedance control issupposed to take out the kinetic energy from the ball and

A High-Speed and High-Precision Position Control Using Sliding Mode Compensator

To achieve high-speed and high-precision position control for semiconductor product machines and industrial robots, the full-closed feedback control is applied. Many control methods have been proposed for such a system. In general, P,PI/I-PI control which is one of PID control is applied to a lot of industrial applications. However, in case of changing mechanical characters of control target, the parameters of P,PI/I-PI control have to be changed for keeping a good motion performance. In this paper, we propose a new P,PI/I-P control method which is with nonlinear compensator. The algorithm of nonlinear compensator is based on sliding mode control with chattering compensation. The effectiveness of proposed control method is evaluated by using full-closed single axis slider system via point to point control and contour control in the case of changing load. From the experimental results, the proposed control method has robustness in the case of changing acceleration/deceleration of control reference, changing load and low velocity contouring motion.

An introduction to computational intelligence techniques for robot control

PurposeThe purpose of this paper is to discuss the application of computational intelligence techniques to the field of industrial robot control.Design/methodology/approachThe core ideas behind using neural computation, evolutionary computation, and fuzzy logic techniques are presented, along with a selection of specific real‐world applications.FindingsTheir practical advantages and disadvantages relative to more traditional approaches are made clear.Originality/valueThe reader will appreciate the power of computational intelligence techniques for industrial robot control, and hopefully be encouraged to explore further the possibility of using them to achieve improved performance in their own applications.

The evolution of robotics research

This article surveys traditional research topics in industrial robotics and mobile robotics and then expands on new trends in robotics research that focus more on the interaction between human and robot. The new trends in robotics research have been denominated service robotics because of their general goal of getting robots closer to human social needs, and this article surveys research on service robotics such as medical robotics, rehabilitation robotics, underwater robotics, field robotics, construction robotics and humanoid robotics. The aim of this article is to provide an overview of the evolution of research topics in robotics from classical motion control for industrial robots to modern intelligent control techniques and social learning paradigms, among other aspects.

Present and future robot control development—An industrial perspective

Robot control is a key competence for robot manufacturers and a lot of development is made to increase robot performance, reduce robot cost and introduce new functionalities. Examples of development areas that get big attention today are multi robot control, safe control, force control, 3D vision, remote robot supervision and wireless communication. The application benefits from these developments are discussed as well as the technical challenges that the robot manufacturers meet. Model-based control is now a key technology for the control of industrial robots and models and control schemes are continuously refined to meet the requirements on higher performance even when the cost pressure leads to the design of robot mechanics that is more difficult to control. Driving forces for the future development of robots can be found in, for example, new robot applications in the automotive industry, especially for the final assembly, in small and medium size enterprises, in foundries, in food industry and in the processing and assembly of large structures. Some scenarios on future robot control development are proposed. One scenario is that light-weight robot concepts could have an impact on future car manufacturing and on future automation of small and medium size enterprises (SMEs). Such a development could result in modular robots and in control schemes using sensors in the robot arm structure, sensors that could also be used for the implementation of redundant safe control. Introducing highly modular robots will increase the need of robot installation support, making Plug and Play functionality even more important. One possibility to obtain a highly modular robot program could be to use a recently developed new type of parallel kinematic robot structure with large work space in relation to the robot foot print. For further efficient use of robots, the scenario of adaptive robot performance is introduced. This means that the robot control is optimised with respect to the thermal and fatigue load on the robot for the specific program that the robot performs. The main conclusion of the presentation is that industrial robot development is far away from its limits and that a lot of research and development is needed to obtain a more widely use of robot automation in industry.