Showing papers on "Articulated robot published in 2022"
TL;DR: This paper presents a method for calibrating a 2D profile laser scanner mounted on an industrial articulated robot using a two-phase least-squares strategy, where rotation is recovered first, followed by translation.
Abstract: This paper presents a method for calibrating a 2D profile laser scanner mounted on an industrial articulated robot; a task also known as the hand-eye calibration problem. The challenge of recovering the transformation matrix, from the robot's flange coordinate system to the scanner's coordinate system, lies in the lack of sufficient 3D information, as only 2D data is available. The task is typically performed using precision calibration specimens such as spheres, disks, and planes or using additional external devices such as cameras and 3D sensors. Here, we present an approach based on detecting straight edges found in common objects. Points extracted from the same edge, under various robot poses, are used to solve the calibration problem using a two-phase least-squares strategy, where rotation is recovered first, followed by translation. The process is semi-autonomous, requires minimal laborious and error-prone manual operations; its setup effort is small, because common objects can be used instead of costly precision gauges or external devices; it does not require large number of samples and it is simple to reason about, implement and compute.
11 citations
TL;DR: The proposed automatic optimization method for planning the cable paths for industrial robot arms applies current physics simulation techniques for reducing the person–hours involved in cable path design and indicates that the proposed method can aid line engineers to efficiently design the cable path along robot arms.
Abstract: The production line engineer's task of designing the external path for cables feeding electricity, air, and other resources to robot arms is a labor-intensive one. As the motions of robot arms are complex, the manual task of designing their cable path is a time-consuming and continuous trial-and-error process. Herein, we propose an automatic optimization method for planning the cable paths for industrial robot arms. The proposed method applies current physics simulation techniques for reducing the person–hours involved in cable path design. Our method yields an optimal parameter vector (PV) that specifies the cable length and cable-guide configuration via filtering the candidate PV set through a cable-geometry simulation based on the mass–spring model. The proposed method offers two key features: 1) Increased computational efficiency via an optimization procedure that separates the entire cable into the cable segments. In the proposed method, the entire cable is segmented at the positions of the cable guides into several separate cable segments, and the PVs of the cable segments that satisfy the constraints of collision, stretch, and curvature radius are filtered into the local optimal PV set. The global optimal PV is obtained by finding the combination of the local optimal PVs which have the same guide configuration between the adjacent cable segments and have minimal total length of the adjacent cable segments. 2) Robustness to external disturbances, such as fluctuation in the physical properties of the cables and the accuracy of manually attaching the cables. The PVs of the local optimal PV sets are required to satisfy the above constraints, even if the cable length changes in the predefined range, which ensures the robustness of the obtained cable path. To verify the validity of the proposed method, we obtain the global optimal PVs by applying the method to several pick-and-place motions of a six-axis vertical articulated robot arm in our simulations and implement the cable paths on an actual robot arm based on the obtained PVs. Our results indicate that the proposed method can aid line engineers to efficiently design the cable paths along robot arms.
6 citations
TL;DR: In this article , a novel in-pipe inspection robot is designed and manufactured in Kharazmi University KharaazmPipeBot, which is able to move through any pipeline with a predefined diameter range with a variable pitch rate and report any desired data within the pipe with the aid of the installed camera.
Abstract: In this article, a novel in‐pipe inspection robot is designed and manufactured in Kharazmi University KharazmPipeBot. This robot is able to move through any pipeline with a predefined diameter range with a variable pitch rate and report any desired data within the pipe with the aid of the installed camera. To achieve the highest stability of the robot through the pipe, the robot's movement is based on the screw locomotion protocol provided by the aid of its rotor and stator. A simple suspension is designed for three legs of the robot by installing a passive prismatic joint equipped with a spring for each leg to provide a smoother movement for the robot chassis. The main novelty of the robot is adding an extra controlling actuator for the robot which is the steer of the front wheels. This input can control the pitch rate of the robot movement and consequently the spiral track of the wheels can be actively managed. This importance lets us to bypass the probable obstacles attached to the inner wall of the pipes. A brief presentation of the robot model is delivered. Afterward, to verify the claimed novelties of the system, a prototype of the robot is manufactured in Kharazmi University and the efficiency of the robot is demonstrated by conducting some initial experimental tests. It is shown that the robot can move with a variable pitch rate through the wall and pass a detected obstacle accordingly.
2 citations
02 Mar 2022
TL;DR: In this article , the authors examined different test scenarios for a constructed WRLIUST robot consisting of four wheels and four single-link legs, and the results were achieved from gyroscope and dynamic results from motor torques.
Abstract: This paper examines different test scenarios for a constructed WRLIUST robot. This robot is consisted of 4 wheels and 4 single-link legs. At first, the mechanical design and construction of the robot is argued, then the electronics and robot circuits are described. To build a wheel-leg robot, a detailed design that meets all the desired requirements, is needed. After design, appropriate mechanical and electrical components are specified and along, the communication of the specified equipment is investigated. In order to determine the most appropriate configuration for the robot, different scenarios were planned and tested. Since the robot has height changes, high torque is needed in leg joints. For this reason, motors with high torques should be utilized. To perform these tests, the cinematic results are achieved from gyroscope and dynamic results from motor torques, and by comparing the torques, the best motion for robot is determined so that the robot withstands the least amount of torque and act more perfectly in the best position.
1 citations
TL;DR: In this article , an improved method of positioning the robot in inverse kinematics is presented, and some new aspects in approaching the forces acting on a robot, but also regarding the determination of loads of the rotary actuators.
Abstract: The paper presents the study of the dynamics of a general DoF robot, highlighting some important new aspects in the dynamic design of a certain DoF robot. An improved method of positioning the robot in inverse kinematics is presented, then some new aspects in approaching the forces acting on a robot, but also regarding the determination of loads of the rotary actuators. Finally, a study is made of the dynamic functioning of the robot, with new and interesting aspects.
TL;DR: In this article , a cable-driven hyper redundant flexible robot arm with 10 joints with 20 degrees of freedom has been developed, where instead of attaching the motors directly at each joint, the motors are deployed outside of the robot and the actuation force is transmitted by the flexible cables to each joint.
Abstract: This report presents the development of a cable-driven hyper redundant flexible robot arm that has 10 joints with 20 degrees of freedom. The robot arm has the cable-driven mechanism for actuating each joint of the robot; instead of attaching the motors directly at each joints of the robot, the motors are deployed outside of the robot and the actuation force from the motors are transmitted by the flexible cables to each joint. The cable-driven mechanism makes the motion of the robot more flexible and dynamic by reducing the loads of motors to the robot. The control algorithm is designed based on the inverse kinematics using Pseudo inverse of Jacobian matrix. Detailed performances of this 10-joint robot arm and experimental results are outlined in further detail throughout this report.
TL;DR: In this article , a stick-slip mechanism is used to control a small mobile robot that can turn left or right on the ground by interplaying between the centrifugal force generated by the vibration motor tilted on the robot and the friction force of the robot.
Abstract: In miniature mobile robots, reducing the number of actuators can effectively reduce the size and weight of the robot. However, it is challenging to design a robot with as few actuators as possible without losing good motion performance. This work presented a simple-structured low-cost miniature mobile robot. It is driven by only a single tilted motor and yet is fully capable of being controlled to move forward and turn left or right on the ground. Based on the stick–slip mechanism, the robot’s motion is achieved by interplaying between the centrifugal force generated by the vibration motor tilted on the robot and the friction force of the robot. The robot’s speed can be controlled by regulating the magnitude and the period of the applied voltage. Finally, the robot can translate and rotate on the ground and follow various arbitrary paths. The prototype weighs only 11.15 g, costs $6.35, and is 20 mm in diameter and 25 mm in height. The proposed system is experimentally verified and demonstrates the controllability of the robot by the movement along a straight line, a circle, and more arbitrary paths.