Off-line Programming System Research Articles

A robot off-line programming system for welding intersecting pipe

In order to meet the requirements of welding intersecting line welds, an off-line programming system is designed. The off-line programming system is developed with SolidWorks API functions, includes kinematics analysis, trajectory planning, off-line simulation and other modules. The system is applied to an ABB welding robot with six revolute joints. The welding experiment of the robot cylindrical intersecting pipe is carried out, and the experimental results verify the system.

ABB Robotic Arm Offline Programming System

The offline programming technology of industrial robots is more and more widely used because it can effectively improve work efficiency. A DXF drawing file is a file generated by CAD that can serve as a bridge for data exchange with other software. Through experiments, this paper combines CAD-generated DXF drawing files with ABB robotic arm to realize data extraction of CAD drawings, and automatic generation and storage of robotic arm running programs, which are imported into the robot arm, so that the robot arm can be made according to CAD. The trajectory on the drawing performs the welding function. The simulation of path planning was carried out under the Robot studio software developed by ABB Robotics to meet the experimental requirements. The realization of this off-line programming system achieves the following two purposes. One is to assist non-control professional teaching, to help understand the simulation and actual production and processing of industrial robot arm; the second is to improve the efficiency of industrial robot arm programming and realize full automation programming.

System identification of the nonlinear residual errors of an industrial robot using massive measurements

Abstract In this paper, an industrial robot is calibrated by identifying the nonlinear residual errors from massively measured tool positions using a laser tracker. A fully automatic measuring system is developed to collect more than 10,000 robot configurations in an efficient manner, which communicates with the robot controller and the laser tracker in real time. The robot configurations are programmed using a laser traceable path planning algorithm, which ensures the tool positions always locate in the expected envelope and the mirror ball keeps aligning against the laser tracker without occlusion. Afterwards, the robot motion control program is automatically generated using a robot simulation and off-line programming system. In order to obtain relatively higher positioning accuracy and less computation time, the off-line calibration procedure is subdivided into two steps. The first step solves the significant structural errors using the model-based parametric calibration. The second step further identifies the nonlinear residual errors using a deep neural network (DNN), so that the deviations related to different robot configurations can be reduced and the overall workspace accuracy can be improved to a much higher level. After calibration, the mean/maximum positioning errors in the measured envelope are reduced from 1.81 mm/1.96 mm, respectively, to 0.10 mm/0.22 mm. The calibrated model is eventually integrated into the off-line programming system, and effectively compensate a robot welding trajectory.

Processing configuration off-line optimization for functionally redundant robotic drilling tasks

As a key technology of robotic assembly system, off-line programming (OLP) is an effective way to improve processing quality and efficiency. Currently, the basic functions of OLP systems, such as trajectory planning, three-dimensional task simulation and collision detection, could not achieve high machining precision and guarantee the quality stability. Thus, robot kinematics and stiffness performance optimization need to be investigated as secondary tasks in the special OLP system, on the basis of redundant kinematics characteristic of a serial robot system with external axis. First, a singularity measurement model of robot configuration is presented under the constraint of joint-limits to achieve the avoidance of singular and joint-limits configurations. Secondly, based on the robot static stiffness model, an axial stiffness identification method has been come up with to evaluate the stiffness performance in the processing direction. Next, with the combination of singularity measurement model and axial stiffness identification method, a redundancy resolution method is put forward to plan and optimize the configuration of robot system with external axis off-line, which keeps robots away from singularity and joint-limits, and meanwhile achieve the optimum stiffness during robotic drilling process. Finally, the validity of this method in improving drilling quality and stability is verified by the application in a robotic drilling system.

Modelling of industrial robot in LabView Robotics

Currently can find many models of industrial systems including robots. These models differ from each other not only by the accuracy representation parameters, but the representation range. For example, CAD models describe the geometry of the robot and some even designate a mass parameters as mass, center of gravity, moment of inertia, etc. These models are used in the design of robotic lines and sockets. Also systems for off-line programming use these models and many of them can be exported to CAD. It is important to note that models for off-line programming describe not only the geometry but contain the information necessary to create a program for the robot. Exports from CAD to off-line programming system requires additional information. These models are used for static determination of reachability points, and testing collision. It’s enough to generate a program for the robot, and even check the interaction of elements of the production line, or robotic cell. Mathematical models allow robots to study the properties of kinematic and dynamic of robot movement. In these models the geometry is not so important, so are used only selected parameters such as the length of the robot arm, the center of gravity, moment of inertia. These parameters are introduced into the equations of motion of the robot and motion parameters are determined.

Flexible robot sealant dispensing cell using RGB-D sensor and off-line programming

In aerospace manufacture the accurate and robust application of sealant is an integral and challenging part of the manufacturing process that is still performed by human operator. Automation of this process is difficult and not cost effective due to the high variability in the parts to operate and also the difficulty associated with programming industrial robotic systems. This work tries to overcome these problems by presenting an AOLP (Automatic Off-Line Programming) system for sealant dispensing through the integration of the ABB's proprietary OLP (Off-Line Programming) system RobotStudio with a relatively new RBG-D sensor technology based on structured light and the development of a RobotStudio add-on. The integration of the vision system in the generation of the robot program overcomes the current problems related to AOLP systems that rely on a known model of the work environment. This enables the ability to dynamically adapt the model according to sensor data, thus coping with environmental and parts variability during operation. Furthermore it exploits the advantages of an OLP system simplifying the robot programming allowing for faster automation of the process.

The Design of General Off-Line Graphical Robot Programming System

The Design of General Off-Line Graphical Robot Programming System

An off-line programming system for palletizing robot

Off-line programming systems are essential tools for the effective use of palletizing robots. This article presents a dedicated off-line programming system for palletizing robots. According to the user practical requirements, there are many user-defined patterns that can’t be easily generated by commercial off-line robot programming systems. This study suggests a pattern generation method that users can easily define their patterns. The proposed method has been simulation and experiment. The results have attested the effectiveness of the proposed pattern generation method.

A study on robotic off-line programming system in induction hardening for fillets or chamfers of mould

As the end-effector of robot, the induction hardening tool is required to keep its orientations perpendicular to the fillets or chamfers of the mould at a distance during its uniform motion along the hardening trajectory. This trajectory consists of a group of central curves which are parametric curves on the corresponding chamfers or fillets and between two edges of every chamfer or fillet. The trajectory points and the surface normal vectors at these points are obtained by parametric equations of the fillets or chamfers. This study is conducted to join each central curve into the entire hardening trajectory, including handling on the irregular surfaces and unifying the directions of hardening tool motion. According to kinematics of robot, the trajectory points in modeling coordinate system are transferred into the poses of the induction hardening tool in user frame of robot. The kinematical interference of the induction hardening tool and robot joints is checked by Roboguide simulation tool. The validity of the robotic off-line programming (OLP) system was verified by experiments.

Off-line programming and simulation for 2-axis wire EDM

This paper presents a methodology for establishing off-line programming system with toolpath verification and simulation including visualization of the machining process, fixture orientation and machine movements. This methodology is described using IDEF0 diagrams and is elaborated by using PTC Creo CAD/CAM system. This paper describes modeled detailed virtual prototype of WEDM machine Ewis, with all kinematic relationships between moving components being defined, with the aim to include virtual machine model in machine simulation. Off-line programming allows immediate execution on the machine of multiple verification programs after verification. Therefore, the off-line programming is verified using the real example and its program verification and execution.

Platform of Industrial Robot Task Simulation Used in Welding Automation

Based on the research progress of off-line programming system, propose a virtual manufacturing platform to simulate and monitor industrial robot welding task, by combining motion simulation of three-dimensional models, welding characteristics information-driven and monitoring communications. The platform designed as a three-dimensional solid modeling foreground, with kinematics algorithms and task characteristics as the core, to achieve a common solution that provide jobs simulation ,tatistical information and on-line monitoring. And there is a feasibility analysis of technical means.

A STEP-compliant Industrial Robot Data Model for robot off-line programming systems

Recently, various robot off-line programming systems have promoted their own robot data models, resulting in a plethora of robot representation methods and unchangeable data files among CAx and robot off-line programming systems. The current paper represents a STEP-compliant Industrial Robot Data Model (IRDM) for data exchange between CAx systems and robot off-line programming systems. Using this novel representation method, most resources involved in a robot manufacturing system can be represented. The geometric and mathematic aspects of industrial robots have been defined in IRDM, so that the robot off-line programming system could have abundant information to represent robots’ kinematic and dynamic behaviors. In order to validate the proposed models and approaches, a prototype robot off-line programming system with 3D virtual environment is presented. The functionalities of IRDM not only have significant meaning for providing a unified data platform for robot simulation systems, but also have the potential capability to represent robot language using the object-oriented concept.

An Industrial Robot Based Drilling System for Aircraft Structures

In order to realize automatic flexible drilling with high efficiency and good quality, a drilling system was established, which integrates the technology of laser measurement, off-line programming, computer control and robotics. In this system, the key coordinate frames are established by the laser tracker, the drilling programs are generated by the off-line programming and simulation system, the communication between the automatic drilling control system and the robot control system is based on the socket technique. By running drilling program, the moving platform, robot and the end effector can work automatically and harmoniously. In addition, the deviation compensation methods of hole position and its normal vector are proposed. The experimental results show that the efficiency of drilling can achieve 6 holes per minute, the position accuracy can be effectively controlled within 0.3mm, and the normal accuracy is better than 0.5°.

An off-line programming system for robotic drilling in aerospace manufacturing

Off-line programming systems are essential tools for the effective use of robots in the manufacturing environment. This paper presents a dedicated off-line programming system for robotic drilling in aerospace manufacturing. Following a brief introduction of the system architecture, the paper discusses two major problems of off-line programming for robotic drilling, i.e., redundancy resolution and position correction. A new performance index is proposed for the combined requirements of singularity and joint-limit avoidance, followed by a discussion of the redundancy resolution scheme by using numerical optimization at the joint displacement level. A position correction method using measurement data of reference holes is developed for the enhancement of robotic drilling accuracy. Robot programs generated by using the developed system have been tested on a robotic drilling system, and the experimental results are provided.

The Off-Line Programming System of Robot Based on CATA Platform

This thesis analyzes the off-line programming system of spraying robot, and study several keys of off-line programming. According to the characteristics of CATIA V5 document structure, a technical scheme for developing off-line programming is proposed. In this scheme, the off-line programming is developed based on CATA platform using CATIA Automation and CAA VC++.

Modelling of metal deposition

Modelling and simulation of metal deposition (MD) poses several challenges to the modeller in addition to the usual challenges in modelling of welding. The aim of the work presented in this paper is to enable simulation of metal deposition for large three-dimensional components. Weld paths that are created in an off-line programming system (OLP) can be used directly to prescribe the movement of the heat source in the model. The addition of filler material is done by activation of elements. Special care must be taken to the positioning of the elements, due to large deformations. Nodes are moved to ensure that the added material has correct volume and shape. A physically based material model is also implemented. This material model is able to describe the material behaviour over a large strain, strain rate and temperature range. Temperature measurements and deformation measurements are done in order to validate the model. The computed thermal history is in very good agreement with measurements. The computed and measured deformations also show quite good agreement. It has been shown that the approach yields correct results, providing that flow stress and heat input models are calibrated with sufficient accuracy. The method reduces the modelling work considerably for metal deposition and multipass welding. It can be used for detailed models but also lumping of welds is possible and often necessary for industrial applications.

Theoretical and practical aspects of robot calibration with experimental verification

One of the greatest challenges in today's industrial robotics is the development of off-line programming systems that allow drastic reduction in robots' reprogramming time, improving productivity. The article purpose is to pave the way to the construction of generic calibration systems easily adapted to any type of robot, regardless their application, such as modular robots and robot controllers specifically designed for non-standard applications. A computer system was built for developing and implementing a calibration system that involves the joint work of computer and measurement systems. Each step of this system's development is presented together with its theoretical basis. With the development of a remote maneuvering system based on ABB S3 controller experimental tests have been carried out using an IRB2000 robot and a measurement arm (ITG ROMER) with 0.087 mm of position measurement accuracy. The robot model used by its controller was identified and the robot was calibrated and evaluated in different workspaces resulting in an average accuracy improvement from 1.5 mm to 0.3 mm.

Designing and Optimization of an Off-line Programming System for Robotic Belt Grinding Process

Off-line programming (OLP) system becomes one of the most important programming modules for the robotic belt grinding process, however there lacks research on increasing the grinding dexterous space depending on the OLP system. A new type of grinding robot and a novel robotic belt grinding workcell are forwarded, and their features are briefly introduced. An open and object-oriented off-line programming system is developed for this robotic belt grinding system. The parameters of the trimmed surface are read from the initial graphics exchange specification (IGES) file of the CAD model of the workpiece. The deBoor-Cox basis function is used to sample the grinding target with local contact frame on the workpiece. The numerical formula of inverse kinematics is set up based on Newton's iterative procedure, to calculate the grinding robot configurations corresponding to the grinding targets. After the grinding path is obtained, the OLP system turns to be more effective than the teach-by-showing system. In order to improve the grinding workspace, an optimization algorithm for dynamic tool frame is proposed and performed on the special robotic belt grinding system. The initial tool frame and the interval of neighboring tool frames are defined as the preparation of the algorithm. An optimized tool local frame can be selected to grind the complex surface for a maximum dexterity index of the robot. Under the optimization algorithm, a simulation of grinding a vane is included and comparison of grinding workspace is done before and after the tool frame optimization. By the algorithm, the grinding workspace can be enlarged. Moreover the dynamic tool frame can be considered to add one degree-of-freedom to the grinding kinematical chain, which provides the theoretical support for the improvement of robotic dexterity for the complex surface grinding.

Off-Line Programming of a Robot for Laser Re-Manufacturing

Off-line programming provides an essential link for CAD/CAM. This paper introduced the principle of developing off-line programming system for laser re-manufacturing. Task and information flow of off-line programming for laser re-manufacturing robot was analyzed and the software structure of off-line programming based on commercial CAD software was constructed. The off-line programming system developed in this study includes 3-D solid model design, direct slicing for obtaining path data, graphical simulation of the robot and its workcell, kinematic model of the robot, motion planning, and creation of the control program for manufacturing process. The CAD software was used to design models of robot, workpiece, coaxial nozzle, and workspace. Through the application programming interface provided by the CAD software, the VC++ and ATL were chosen to develop such modules as direct slicing for obtaining path data, path planning, process specification, and control program automatic generation. The FANUC Roboguide software was used to realize graphical simulation. By direct slicing, the position and orientation data of robot end-effector was determined. The results show that the proposed system can be applied in laser re-manufacturing robot for manufacturing operations.

INVERSE KINEMATICS OF 2R POSITIONER BASED ON WELDING POSTION REPRESENTATION

An algorithm of general 2R(rotation) positioner inverse kinematics is presented. According to the model of the welding position, giving a weld seam point, the weld orientation then can be resolved from the weld rotation angle and the weld slope angle. Symbolic are used to represent the positioner's link parameters and the orientation matrix between the robot and the positioner. The kinematics coordinate systems are established , the formula of 2R positioner inverse kinematics is derived. The simulation experiment results show that this algorithm can improve the ability of robotic arc welding off-line programming system to program all types of welding positions . This algorithm can also be used when the positioner is placed differently.