基于面向工业机器人控制器的软PLC系统软件开发分析

在我国自动化、机械化程度不断提高之下,在机械制造领域当中已经开始广泛使用工业机器人,而工业机器人控制器也越来越标准化,其开放度也逐渐提升。在工业机器人当中,软PLC系统是其中至关重要的一项组成部分,符合逻辑控制以及总线通信等工作。本文将在此背景之下,着重围绕基于面向工业机器人控制器的软PLC系统软件开发进行简要分析研究。

Enabling Technologies for Autonomous Robotic Systems in Manufacturing

Research of autonomous manufacturing systems is motivated both by the new technical possibilities of cyber-physical systems and by the practical needs of the industry.Autonomous operation in semi-structured industrial environments can now be supported by advanced sensor technologies,digital twins,artificial intelligence and novel communication techniques.These enable real-time monitoring of production processes,situation recognition and prediction,automated and adaptive(re)planning,teamwork and performance improvement by learning.This paper summarizes the main requirements towards autonomous industrial robotics and suggests a generic workflow for realizing such systems.Application case studies will be presented from recent practice at HUN-REN SZTAKI in a broad range of domains such as assembly,welding,grinding,picking and placing,and machining.The various solutions have in common that they use a generic digital twin concept as their core.After making general recommendations for realizing autonomous robotic solutions in the industry,open issues for future research will be discussed.

An adaptive switching control approach for trajectory tracking of robotic manipulators

In order to design a suitable controller which can achieve accurate trajectory tracking and a good control performance, and guarantee the stability and robustness of a robot system due to external disturbances error and internal parameter variations, an adaptive switching control strategy is proposed. The proposed scheme is designed under the condition of bounded distances and consists of an adaptive switching law and a PD controller. Based on the Lyapunov stability theory, it is proved that the proposed scheme can guarantee the tracking performance of the robotic manipulator and is adapted to varying unknown loads. Simulations are carded out on a two-link robotic manipulator, which illustrate the feasibility and validity of the proposed control scheme and the robustness for variational payloads.

The Development of Dynamic Compliant Wrist for Robots

Based on an analysis of the relative shaft-to-hole position and attiude errors, as well as of the mechanics and Kinematics in the process of automatic assembly of industrial robots, the paper studies the principle of construction of dynamic wrists. Type I-3 and Ⅱ-6 dynamic compliant wrists have been designed and made. Prblems in the production of compliant elements and the connection between compliant elements and wrists were also solved. A study on the results of tests of the function of two kinds of dynamic compliant wrists shows that the dynamic compliant wrist's compliancy function can be improved by adding metallic materials having higher longitudinal and transverse rigidity into the softer elstomer. And the design Principle is proved to be feasible and practicable. It can be expected that the use of dynamic compliant wrist will greatly lower the technical requirements of the shaft-hole assembly and the requirements in the resetting accuracy.

Realization of orientation interpolation of 6-axis articulated robot using quaternion

In general, the orientation interpolation of industrial robots has been done based on Euler angle system which can result in singular point （so-called Gimbal Lock）. However, quaternion interpolation has the advantage of natural （specifically smooth） orientation interpolation without Gimbal Lock. This work presents the application of quatemion interpolation, specifically Spherical Linear IntERPolation （SLERP）, to the orientation control of the 6-axis articulated robot （RS2） using LabVIEW and RecurDyn. For the comparison of SLERP with linear Euler interpolation in the view of smooth movement （profile） of joint angles （torques）, the two methods are dynamically simulated on RS2 by using both LabVIEW and RecurDyn. Finally, our original work, specifically the implementation of SLERP and linear Euler interpolation on the actual robot, i.e. RS2, is done using LabVIEW motion control tool kit. The SLERP orientation control is shown to be effective in terms of smooth joint motion and torque when compared to a conventional （linear） Euler interpolation.

Dynamic Velocity Feed-Forward Compensation Control with RBF-NN System Identification for Industrial Robots

A dynamic velocity feed-forward compensation （RBF-NN） dynamic model identification was presented for control （DVFCC） approach with RBF neural network the adaptive trajectory tracking of industrial robots. The proposed control approach combined the advantages of traditional feedback closed-loop position control and computed torque control based on inverse dynamic model. The feed-forward compensator used a nominal robot dynamics as accurate dynamic model and on-line identification with RBF-NN as uncertain part to improve dynamic modeling accu- racy. The proposed compensation was applied as velocity feed-forward by an inverse velocity controller that can con- vert torque signal into velocity in the standard industrial controller. Then, the need for a torque control interface was avoided in the real-time dynamic control of industrial robot. The simulations and experiments were carried out on a gas cutting manipulator. The results show that the proposed control approach can reduce steady-state error, suppress overshoot and enhance tracking accuracy and efficiency in joint space and Cartesian space, especially under high- speed condition.

Research on Robotics Application in Fruit Harvesting

The study was aimed to identify the problems and also to suggest some solutions for robotic systems applications in harvesting of kiwi and apples. The results obtained show that physicomechanical properties of the harvested fruits had an effect on the use of robotic systems. Parameters such as weight, height, width, thickness and surface area were identified as the main effect in robotic fruit harvesting. Image processing techniques also had direct effect on robotic systems operation which therefore requires careful selection procedure to achieve results accuracy. It was observed that the C# programming language used in robotic systems fruit harvesting should be parallel with the image processing to ensure accurate conversion of kinematic calculation, system input parameters and constant values. The use of hobby-type parts of a robot in the prototype study showed reliable results. However, to ensure functionality of the robotic systems application, industrial robots and servo engines should be used. It was also observed that the use of a gripper for picking the fruits from the branch must The engines that make the system work should be strong and the be made considering the physicomechanical properties of the fruit. cutting system should also be appropriate.

Design of Calibration Experiments for Identification of Manipulator Elastostatic Parameters

The paper is devoted to the elastostatic calibration of industrial robots, which is used for precise machining of large-dimensional parts made of composite materials. In this technological process, the interaction between the robot and the workpiece causes essential elastic deflections of the manipulator components that should be compensated by the robot controller using relevant elastostatic model of this mechanism. To estimate parameters of this model, an advanced calibration technique is applied that is based on the non-linear experiment design theory, which is adopted for this particular application. In contrast to previous works, it is proposed a concept of the user-defined test-pose, which is used to evaluate the calibration experiments quality. In the frame of this concept, the related optimization problem is defined and numerical routines are developed, which allow generating optimal set of manipulator configurations and corresponding forces/torques for a given number of the calibration experiments. Some specific kinematic constraints are also taken into account, which insure feasibility of calibration experiments for the obtained configurations and allow avoiding collision between the robotic manipulator and the measurement equipment. The efficiency of the developed technique is illustrated by an application example that deals with elastostatic calibration of the serial manipulator used for robot-based machining.

A framework for multi-session RGBD SLAM in low dynamic workspace environment

Mapping in the dynamic environment is an important task for autonomous mobile robots due to the unavoidable changes in the workspace. In this paper, we propose a framework for RGBD SLAM in low dynamic environment, which can maintain a map keeping track of the latest environment. The main model describing the environment is a multi-session pose graph, which evolves over the multiple visits of the robot. The poses in the graph will be pruned when the 3D point scans corresponding to those poses are out of date. When the robot explores the new areas, its poses will be added to the graph. Thus the scans kept in the current graph will always give a map of the latest environment. The changes of the environment are detected by out-of-dated scans identification module through analyzing scans collected at different sessions. Besides, a redundant scans identification module is employed to further reduce the poses with redundant scans in order to keep the total number of poses in the graph with respect to the size of environment. In the experiments, the framework is first tuned and tested on data acquired by a Kinect from laboratory environment. Then the framework is applied to external dataset acquired by a Kinect II from a workspace of an industrial robot in another country, which is blind to the development phase, for further validation of the performance. After this two-step evaluation, the proposed framework is considered to be able to manage the map in date in dynamic or static environment with a noncumulative complexity and acceptable error level.

Development of Autonomous Travelling Device for Oil Palm FFB （Fresh Fruit Bunches） Harvester

Robot technology is a very promising technology for agricultural sector, but the existing industrial robot could not deliver the above-mentioned criteria. Industrial robot mainly uses high voltage electrical power, which is not available at field and outdoor operation. The only available and reliable power is a hydraulic from the tractor. The harvester robot consumes the hydraulic power from the tractor and at the same time the tractor can be used as a traveling device for the robot. This paper describes the study on the development of autonomous tractor for the oil palm harvester. The development took considerations on the design of the electro-hydraulic system and the control software for the robot structure to be flexible enough to operate in plantation environment.

Design of Industrial Robotic Controller Based on DSP

This paper describes the design of industrial robot controller based on the DSP technology. Robotic real time control is realized by PC and DSP motion control card and this method improves the performance of robotic controller. Finally this paper gives some experiment results and conclusion.

Research on Precision Assembly Robot's Joint Torque Control Based on Current Measurement

A set of new current sensing device is used to realize joint torque control based on current measurement in a precision assembly robot's third joint. The output torque's model of the joint's brushless DC motor is founded. Disturbance factors and the compensated effect of the torque's closed loop based on current measurement are analyzed. Related simulations and experiments show that the system has good current tracking and anti-disturbances performance, which improve the force control performance of the robot in assembly.

A Bayesian Approach to Robot Group Control

This paper describes a Bayesian approach to robot group control applied in industrial applications. The proposed model is based on well-known concepts of Ubiquitous Computing and can enable some degree of contextual perception of the environment. Compared with classical industrial robots, usually preprogrammed for a limited number of operations/actions, the system based on this model can react in uncertain situations and scenarios. The model combines ontology to describe the specific domain of interest and decision-making mechanisms based on Bayesian Networks to enable the work of a single robot without human intervention by learning Behavioral Patterns of other robots in the group. The described model is designed to be expressive enough to provide adequate level of abstractions needed for making timely appropriate actions and respecting the current application.

Robotic Path Learning with Graphical User Interface

This paper describes an automated path generation method for industrial robots. Based on force control, a robotic subsystem has been developed for path automatic generation or path learning. Using a dummy tool and roughly taught guiding points around a part contour, the robot moves in position and force controlled hybrid mode, following the order of the guiding points and with contact force direction and value predefined. During the motion, robot actual position is recorded by the robot controller. After the motion, the recorded position data is used to generate a robot path program automatically. Robot lead-through may be used in the guiding point teaching. Furthermore, a GUI （graphical user interface） is developed on the teach pedant to guide through the guiding point creation and teaching, path learning, program verification and execution. The development has been incorporated into a robotic machining product option. Combination of the robot path learning function and GUI enhances the interaction between the robot and operator and drastically increases the level of robotic ease-of-use.

Construction of Mechanized Claw as a Teaching Method in Engineering

The labor market requires, increasingly, an updated and more professional preparation, mainly due to the rapid pace of scientific technical advancement means in the industry. From this point, it is important to encourage the development of the basic techniques of control systems, electronics and communication in order to produce knowledge in the mechatronic field and so apply them to industry. Considering the relevance of this subject, the students of Federal University of Para-Campus Tucumi through the Research Group of Electrical and Mechanical Systems apply their knowledge in multidisciplinary engineering fields in order to generate knowledge from creative techniques using low cost materials, together with the encouragement of social and environmental responsibility which is very important nowadays. At the same time, targeting the needs of the labor market, this work aims to foster in students the skills and requirements through team projects and innovative methods. Therefore, this paper presents a mechanical manipulator, where their operating characteristics are based on industrial robots in the literature, powered by DC （direct current） motors and fully developed from reusable materials. By adding a developed control from the Arduino, prototyping platform with an electronic strategic offers through the internet the long-distance control convenience.

Adaptive Robust Control for an Active Heave Compensation System

Active heave compensation systems are usually employed in offshore and deep-sea operations to reduce the adverse impact of unexpected vessel’s vertical motion on the response of underwater instruments.This paper presents a control strategy for an active heave compensation system consisting of an electro-hydraulic system driven by a double rod actuator,which is subjected to parametric uncertainties and unmeasured environmental disturbances.Adaptive observer and discontinuous projection type updating law with bounded adaption rate are presented firstly to estimate the uncertain system parameters.Then a similar estimation algorithm is designed by using a multiple delayed version of the system to enhance the performance of parameter observation.A reduced order observer is also introduced to estimate unknown wave disturbances.Using the obtained uncertainty information,the resulting control development and stability analysis are implemented based on the Lyapunov’s direct method and back-stepping technique.The proposed controller guarantees the heave compensation error convergent to a bounded neighborhood around the origin.Simulations illustrate the effectiveness of the proposed control system.