Motion Control Of Industrial Robots Research Articles

Research on sensing recognition principle and motion control of industrial robot

In recent years, with the continuous development of science and technology and the pursuit of production efficiency, robots are more and more widely used in industrial production. Robot is a new production tool in industrial production. This paper mainly studies the sensing and recognition technology of industrial robots and their motion control principle. The purpose of this paper is to discuss the main research directions and important design methods of industrial robots. The research methods used in this paper are literature analysis, case analysis, and review. The research object is the sensing and recognition function of the industrial robot itself, as well as its motion and control parts. The main tools used in the study are various literature database websites, and the experimental data are also extracted from the papers in the database. This paper finds that the key research of industrial robots today is to make their recognition function powerful and strive to optimize their motion ability.

Feasibility of motion control of industrial robots, CNC machine tools and mechatronic systems. Part 2

The problem of realization of control systems in real time is investigated. The relationship between the complexity of control objects and the duration of the control cycle is revealed, according to which, as the complexity of control objects increases, the duration of the control cycle is reduced. This leads to an increase in requirements for the speed of control systems, which can be achieved by increasing the speed of the used electronic component base and other elements of the control system, as well as optimizing the architecture of the control system. One of the most promising directions in the development of real-time control systems for complex objects is the use of a memory-centric architecture of the control system. Keywords: motion control, industrial robot, machine tool, mechatronic system, control cycle, memory-centric architecture. andarmo@yandex.ru

Feasibility of motion control of industrial robots, CNC machine tools and mechatronic systems. Part 1

The problem of real-time motion control systems for complex objects is investigated. A condition for the feasibility of control is formed depending on the duration of the control cycle, the complexity of the object and the speed of the system. Keywords: motion control, industrial robot, machine tool, mechatronic system, control cycle, memory-centric architecture. andarmo@yandex.ru

Automated Commissioning of Offline-Generated Robot Programs

The flexibility of industrial robots accounts for their importance in reconfigurable production systems. Advanced methods of offline programming based on 3D simulation promise seamless adaptation to changing circumstances. However, since digital planning models generally do not match reality, the commissioning of computer-generated robot programs involves extensive manual adjustment to the on-site conditions. This paper presents a concept for the automated commissioning of offline-generated robot programs to reduce downtimes of industrial robots and to increase the process consistency of offline robot programming. The presented approach aims for a hybrid motion control of industrial robots that automatically compensates for deviations between simulation and reality. For this purpose, robot poses are described not only by the joint positions but also by the anticipated sensor information. During process execution, robot poses are adjusted as required on the basis of the sensor data collected online.

Position domain control technology for six-joint robots

In the context of the rapid development of intelligent manufacturing, high-precision motion control of industrial robots has attracted increasing research attention. High-speed and high-precision motion control is a development trend associated with the current industrial robots. Industrial transformation and upgradation can be accelerated only via the independent research and development of robot core technologies, including robot high-precision control systems, ensuring the transition of the manufacturing industry in China toward intelligent and digital development. Currently, the contour tracking error associated with majority of the multiaxes CNC machine tools and multijoint industrial robots is a common problem. A good tracking performance can be achieved in time with respect to each joint axis when the space trajectory of the serial multijoint industrial robot changes under multiaxes linkage. The ideal contour trajectory cannot be fully ensured because of the mechanical and electrical hysteresis effects. Therefore, the synchronization of the motion of each servo axis in the geometric space is very important. In this paper, the existing kinematics and dynamics of industrial robots were combined with the traditional PID control theory for studying position domain control algorithm of the six-joint robot to resolve the problem of low accuracy associated with the robot end profile, which can be attributed to the lag between the motion instruction and the actual position. The algorithm uses the method of real-time establishment of the master–slave motion relation for controlling the spatial contour trajectory of the robot. It further transforms the synchronization control method of each servo joint in the time domain into the master–slave follow control method of each servo joint in the position domain. While realizing synchronization control in the position domain, PD control based on position domain was introduced to reduce the following error of the master–slave following control, improving the overall accuracy of the contour motion of the robot end. The method proposed in this paper has been tested on the Linux CNC numerical control system with a company’s HSR-JR605 robot, indicating that the position of the domain control method employed positively affects the accuracy of six articulated robot space trajectory.

Kinematics Control and Analysis of Industrial Robot

The robot’s development present situation, basic principle and control system are introduced briefly. Research is mainly focused on the study of the robot’s kinematics and motion control. The structural analysis of a planar articulated robot (SCARA) robot is presented,the coordinate system is established to obtain the position and orientation matrix of the end effector,a method of robot kinematics analysis based on homogeneous transformation method is proposed, and the kinematics solution of the robot is obtained.Establishment of industrial robot’s kinematics equation and formula for positive kinematics by example. Finally,the kinematic analysis of this robot was verified by examples.It provides a basis for structural design and motion control.It has active significance to promote the motion control of industrial robot.

A fixed-distance planning algorithm for 6-DOF manipulators

Purpose– The purpose of this paper is to propose a new trajectory planning algorithm for industrial robots, which can let the robots move through a desired spatial trajectory, avoid colliding with other objects and achieve accurate movements. Trajectory planning algorithms are the soul of motion control of industrial robots. A predefined space trajectory can let the robot move through the desired spatial coordinates, avoid colliding with other objects and achieve accurate movements.Design/methodology/approach– The mathematical expressions of the proposed algorithm are deduced. The speed control, position control and orientation control strategies are realized and verified with simulations, and then implemented on a six degrees of freedom (6-DOF) industrial robot platform.Findings– A fixed-distance trajectory planning algorithm based on Cartesian coordinates was presented. The linear trajectory, circular trajectory, helical trajectory and parabolic trajectory in Cartesian coordinates were implemented on the 6-DOF industrial robot.Originality/value– A simple and efficient algorithm is proposed. Enrich the kind of trajectory which the industrial robot can realize. In addition, the industrial robot can move more concisely, smoothly and precisely.

Motion control of industrial robots by considering serial two-link robot arm model with joint nonlinearities

This paper presents a model based motion control approach for industrial robots by considering a serial two-link robot arm model with joint nonlinearities. In order to achieve the desired performance using the model based control approaches, it is important to obtain relevant models of both kinematics and dynamics including nonlinear characteristics. Main nonlinear components that lead to trajectory tracking errors of typical multi-axis industrial robot are joint nonlinearities in each axis and dynamic coupling effects between different axes. In this paper, a parametric modeling approach is introduced to reproduce behaviors of a serial two-link robot arm with joint nonlinearities. Nonlinear stiffness, angular transmission errors, and friction in these two links are directly identified as joint nonlinearities. This approach is applied for the serial two-link arm of a typical multi-axis industrial robot, which has low frequency vibration modes and significantly affects to the trajectory performance. Effectiveness of the modeling is verified by comparative studies with numerical simulations and experiments. Finally, a 2-DOF control scheme with the identified two-link dynamic model and a feedback loop-shaping with a variable notch filter are applied to improve the performance of trajectory tracking and residual vibration suppression.

The Research on the Motion Control of Industrial Robots Based on LabVIEW

This paper puts forward a method to control the industrial robots based on the NI Corporations LabVIEW virtual instrument technology. By designing the communication protocol between the LabVIEW software program on PC and industrial robots, the LabVIEW program can take the control of industrial robots by using RS232 serial ports, including the operation instructions' transmission, the feedback of the robots' running, and the data exchange between the two. The result shows that can effectively realize the motion control of industrial robots based on LabVIEW.

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.

Robust Motion Control of Industrial Robot Based on Robot Parameter Identification and Feedforward Control Considering Resonant Frequency

In control application of industrial robot manipulator, a two-inertia resonant system is normally represented as the basic plant model for various control schemes. Various control techniques with partially feedback linearization have been proposed to achieve high performance motion control. The design of such controllers basically relies on system mechanical parameters. The proper parameters of the model cannot be obtained by the parameter identification based on only manipulator force and motion measurements. In this paper, the open-loop resonant frequency characteristic of the flexible joint is employed to identify the proper mechanical parameters of the two-inertia model. The nominal link inertia and spring constant of gear drive can be readily measured by this novel identification method. The identified parameters are used in independent-joint controller design for conventional PD control scheme and robust control scheme to verify the effectiveness of the proposed identification method. Moreover, the accuracy improvement of the proposed robust control scheme based on feedforward inverse dynamic compensation and D-PD position control gives support the validity of the proposed identification method.