Common Industrial Robot Research Articles

Comparison of Semi-autonomous Mobile Robot Control Strategies in Presence of Large Delay Fluctuation

We propose semi-autonomous control strategies to assist in the teleoperation of mobile robots under unstable communication conditions. A short-term autonomous control system is the assistance in the semi-autonomous control strategies, when the teleoperation is compromised. The short-term autonomous control comprises of lateral and longitudinal functions. The lateral control is based on an artificial potential field method where obstacles are repulsive, and a route is attractive. LiDAR-based artificial potential field methods are well studied. We present a novel artificial potential field method based on color and depth images. Benefit of a camera system compared to a LiDAR is that a camera detects color, is cheaper, and does not have moving parts. Moreover, utilization of active sensors is not desired in the particle accelerator environment. A set of experiments with a robot prototype are carried out to validate this system. The experiments are carried out in an environment which mimics the accelerator tunnel environment. The difficulty of the teleoperation is altered with obstacles. Fully manual and autonomous control are compared with the proposed semi-autonomous control strategies. The results show that the teleoperation is improved with autonomous, delay-dependent, and control-dependent assist compared to the fully manual control. Based on the operation time, control-dependent assist performed the best, reducing the time by 12% on the tunnel section with most obstacles. The presented system can be easily applied to common industrial robots operating e.g. in warehouses or factories due to hardware simplicity and light computational demand.

Selection of Industrial Robots Problem Using Complex Proportional Assessment (COPRAS) Method

Industrial Robot is continuously moving assembly line Intensive production required by to automate tasks A created one. Big, as heavy robots, they are a At standard conditions within an industrial plant are placed, and other All labour works Processes also revolve around them. Obvious robots too Common industrial robots. They are like human hands Looks, that's what they are Robotic arm or manipulator Also called hand. Many There with degree of independence Accents are obvious weapons Allow a wide range of motion.Industrial robots functional quality, Safety and productivity Improve almost every production Also widely used in companies. Nature of work to be done Depending, there are many types of robots now Commercially from different manufacturers are available. analysis of the COPRAS method in this complex proportional estimation (COPRAS) system in 1994 zavadskas, kaklauskas and sarka introduced by this time index values increase and decrease used to estimate. Alternative: ASEA-IRB 60/2, Cincinnati Milacrone T3-726, Cybotech V15 Electric Robot, Unimation PUMA 500/600, United States Robots Maker 110, Yaskawa Electric Motoman L3C.Evaluation preference: repeatability, memory capacity, manipulator reach, load capacity, maximum tip speed. The result it is seen that Cybotech V15 Electric Robot is got the first rank where as is the ASEA-IRB 60/2 is having the lowest rank.

High-precision assembly of electronic devices with lightweight robots through sensor-guided insertion

Through-hole devices still play an important role in power electronics production. Due to a high number of variants in this field, an automated placement by special machines is often not economically feasible. The resulting manual process is characterized by monotony, ergonomic strain and high labor cost. As a result, a partial automation, using lightweight robots in hybrid assembly system, yields high potential. The lower stiffness and resulting accuracy deficiency of lightweight robots compared to common industrial robots, combined with the precision requirements and inherent fragility of the devices, prohibits the deployment of such systems. In this contribution, a scalable setup and strategies for visual and force-torque guided tactile insertion of such devices is presented and evaluated. A library, based on a system for the offline-programming of such tasks, is used to decrease implementation efforts. A performance evaluation of the system on printed circuit boards with multiple different devices is conducted.

Torque control based direct teaching for industrial robot considering temperature-load effects on joint friction

Purpose The purpose of this paper is to design a practical direct teaching method for the industrial robot with large friction resistance and gravity torque but without expensive force/torque sensor, where the gravity torque is just a function of joints position, whereas the friction is closely associated with joint velocity, temperature and load. Design/methodology/approach In the teaching method, the output torque of joint motor is controlled through current to compensate gravity torque completely and friction resistance incompletely. Three variables closely associated with friction are investigated separately by experiment and theoretical analysis, and then a comprehensive friction model which is used to calculate the required compensated friction torque is proposed. Finally, a SIASUN 7 degrees of freedom robot was used to verify the model and the method. Findings Experimental results demonstrated that the teaching method enables an operator to teach the robot in joint space by applying small force and torque on either end-effector or its body. The friction investigation suggests that the velocity and temperature have a strong nonlinear influence on viscous friction, whereas load torque significantly influences the Coulomb friction linearly and causes a slight Stribeck effect. Originality/value The main contribution includes the following: a practical joint space direct teaching method for a common industrial robot is developed, and a friction model capturing velocity, temperature and load for robot joints equipped with commercialized motors and harmonic drives is proposed.

Indirect solution of optimal control problems with state variable inequality constraints: finite difference approximation

SUMMARYIn this paper, a method for the indirect solution of the optimal control problem (OCP) in the presence of pure state variable inequality constraints (SVICs) and mixed state-control inequality constraints (SCIC), without a need for a close initial guess is presented. In the proposed method, using the finite difference approximation (FDA), the pure SVICs are converted to SCIC. Here, the distance of the constraint function to the feasibility bounds of the constraint is computed in every situation and the control signal is chosen appropriately to facilitate the constraint stays safe. In this method, prior knowledge of the numbers and sequences of activation times is not required. So, it can be simply implemented in continuous boundary value problem (BVP) solvers. The proposed method simply applies the SVICs and since the constraint is directly applied on the control signal, it improves the convergence. On the other hand, because of the convergence problem in the indirect solution of OCP, the simple homotopy continuation method (HCM) is used to overcome the initial guess problem by deploying a secondary OCP for which the initial guess can be zero. The proposed approach is applied on a few comprehensive problems in the presence of different constraints. Simulations are compared with the direct solution of the OCP to confirm the accuracy and with the penalty function method and the sequential constraint-free OCP to confirm the convergence. The results indicate that the FDA method for handling the constraints along with the HCM is easy to apply with acceptable accuracy and convergence, even for highly nonlinear problems in robotic systems such as the constrained time optimal control of a two-link manipulator (TLM) and a three-link common industrial robot.

Determining the Energy-Optimal Base Position of Industrial Robots by Means of the Modelica Multi-Physics Language

A novel technique for determining the energy-optimal base position of common Industrial Robot (IR) is presented. At first, an energy-focused IR model is developed by means of the Modelica/Dymola simulation environment. Then, for a given IR task, a standard but efficient optimization technique is employed, which allows to determine the robot base position corresponding to the minimum energy consumption. A set of graphical maps is finally provided, which allows a rapid estimation of the energy demand along with the time required for the task completion.

Research on Kinematics and Trajectory Planning for 6-DOF Industrial Robot

The industrial robot is a typical electromechanical integration equipment constituted by operating machine, controller, servo drive system and the detection of sensing device. It is one of the most common industrial robots in the industrial field, which makes it work in almost any track or angle. This paper mainly presents the research on kinematics and trajectory planning for 6-DOF industrial robot. This study has finished the linear interpolation and arc interpolation in the Cartesian space. According to the advantages and disadvantages, this paper proposes the method of quadratic interpolation that meets the demands of 6-DOF industrial robot motion in the joints space and Cartesian space which ensures that the motion of 6-DOF industrial robot is smooth and stable.

Joint Stiffness Identification and Flexibility Compensation of Articulated Industrial Robot

Articulated robots are the most common industrial robots for their large workspace and flexibility. However, the existence of joint flexibility makes those robots difficult to achieve high absolute position accuracy. This paper presents a method to identify the joint stiffness of the robot. The basic idea of that method is to get joint stiffness based on Hooks Law through stepping movement of a single joint and calculating the corresponding joint gravity torque of every step. The practicality of that method is verified by experiment and a plan is carried out to compensate the joint flexibility.

Simulation of Robot Motions by Kinematic Configuration Control

The kinematic configuration control technology bases on a new approach for redundancy resolution. The approach allows to obtain a closed-form solution of the inverse kinematics for redundant robots with regular kinematic chains, as for common nonredundant industrial robots. The off-line evaluated inverse functions need low on¬line computing power and allow to perform local real-time robot motion control in environments with obstacles. Computer simulations of robot motions resulting from the kinematic configuration control are presented by example of a redundant 7 DoF manipulator.

Kinematics of common industrial robots

An approach to finding the solution equations for simple manipulators is described which enhances the well known method of Paul, Renaud, and Stevenson, by explicitly making use of known decouplings in the manipulator kinematics. This reduces the set of acceptable equations from which we obtain relationships for the joint variables. For analyzing the Jacobian, such decoupling is also useful since it manifests itself as a block of zeros, which makes inversion much easier. This zero lock can be used to obtain a concise representation for the forward and inverse Jacobian computations. The decoupling also simplifies the calculations sufficiently to allow us to make good use of a symbolic algebra program (MACSYMA) in obtaining our results. Techniques for using MACSYMA in this way are described. Examples are given for several industrial manipulators.

Analysis of Five-Degree-of-Freedom Robot Arms

Many kinds of robot arms with five degrees of freedom are widely used in industry for arc welding, spray painting, assembling etc. It is necessary to be able to compute joint displacements when such devices are computer controlled. A solution to this problem is presented and the analysis is illustrated by a numerical example using the most common industrial robot with five axes. Further, special cases are discussed using screw theory.