9,791 research outputs found
Development of a quadruped mobile robot and its movement system using geometric-based inverse kinematics
As the main testbed platform of Artificial Intelligence, the robot plays an essential role in creating an environment for industrial revolution 4.0. According to their bases, the robot can be categorized into a fixed based robot and a mobile robot. Current robotics research direction is interesting since people strive to create a mobile robot able to move in the land, water, and air. This paper presents development of a quadruped mobile robot and its movement system using geometric-based inverse kinematics. The study is related to the movement of a four-legged (quadruped) mobile robot with three Degrees of Freedom (3 DOF) for each leg. Because it has four legs, the movement of the robot can only be done through coordinating the movements of each leg. In this study, the trot gait pattern method is proposed to coordinate the movement of the robot's legs. The end-effector position of each leg is generated by a simple trajectory generator with half rectified sine wave pattern. Furthermore, to move each robot's leg, it is proposed to use geometric-based inverse kinematic. The experimental results showed that the proposed method succeeded in moving the mobile robot with precision. Movement errors in the translation direction are 1.83% with the average pose error of 1.33 degrees, means the mobile robot has good walking stability
Working and Assembly Modes of the Agile Eye
This paper deals with the in-depth kinematic analysis of a special spherical
parallel wrist, called the Agile Eye. The Agile Eye is a three-legged spherical
parallel robot with revolute joints in which all pairs of adjacent joint axes
are orthogonal. Its most peculiar feature, demonstrated in this paper for the
first time, is that its (orientation) workspace is unlimited and flawed only by
six singularity curves (rather than surfaces). Furthermore, these curves
correspond to self-motions of the mobile platform. This paper also demonstrates
that, unlike for any other such complex spatial robots, the four solutions to
the direct kinematics of the Agile Eye (assembly modes) have a simple geometric
relationship with the eight solutions to the inverse kinematics (working
modes)
Development of Omni-Wheeled Mobile Robot Based-on Inverse Kinematics and Odometry
This paper presents the development of an omniwheeled mobile robot based on inverse kinematics and odometry for local and indoor navigation purposes, such as for automatic warehousing in industry or healthcare environment. The robot uses four-wheeled diagonal configuration to conform directional angles of 1 =45°, 2=135°, 3=225°, and 4=315°. Inverse kinematics is utilized to drive the robot to a point with specific trajectory and heading angle. Internal wheeledencoders mounted in each DC-motors are used to read the angular speed and position. This research utilizes odometry technique to estimate the robot’s position relative to the initial position. In order to develop a more precise odometry result, we combine the use of wheeled-encoders and an IMU. In order to maintain robot’s position relative to the desired position, a PID control is applied to the algorithm. The result of the tests show that the developed omni-wheeled mobile robot is capable of performing locomotion to the desired position and to follow a controlled trajectory by maintaining a minimum error relative to the referenced trajectory
Motion planning of a climbing parallel robot
This paper proposes a novel application of the
Stewart–Gough parallel platform as a climbing robot and its kinematics
control to climb through long structures describing unknown
spatial trajectories, such as palm trunks, tubes, etc. First, the description
and design of the climbing parallel robot is presented. Second, the inverse
and forward kinematics analysis of a mobile six-degrees-of-freedom
parallel robot is described, based on spatial constraint formulation.
Finally, the gait pattern and the climbing strategy of the parallel robot is
described. The information from this research is being used in an actual
climbing parallel robot design at Miguel Hernández University of Elche
(Alicante), Spain.This paper was
recommended for publication by Associate Editor M. Shoham and Editor I.
Walker upon evaluation of the reviewers’ comments. This work was supported
by the Spanish Ministry of Education and Culture under Project 1FD1997-1338
Kinematics and workspace analysis of a 3ppps parallel robot with u-shaped base
This paper presents the kinematic analysis of the 3-PPPS parallel robot with
an equilateral mobile platform and a U-shape base. The proposed design and
appropriate selection of parameters allow to formulate simpler direct and
inverse kinematics for the manipulator under study. The parallel singularities
associated with the manipulator depend only on the orientation of the
end-effector, and thus depend only on the orientation of the end effector. The
quaternion parameters are used to represent the aspects, i.e. the singularity
free regions of the workspace. A cylindrical algebraic decomposition is used to
characterize the workspace and joint space with a low number of cells. The
dis-criminant variety is obtained to describe the boundaries of each cell. With
these simplifications, the 3-PPPS parallel robot with proposed design can be
claimed as the simplest 6 DOF robot, which further makes it useful for the
industrial applications
Self-Motions of General 3-RPR Planar Parallel Robots
This paper studies the kinematic geometry of general 3-RPR planar parallel
robots with actuated base joints. These robots, while largely overlooked, have
simple direct kinematics and large singularity-free workspace. Furthermore,
their kinematic geometry is the same as that of a newly developed parallel
robot with SCARA-type motions. Starting from the direct and inverse kinematic
model, the expressions for the singularity loci of 3-RPR planar parallel robots
are determined. Then, the global behaviour at all singularities is
geometrically described by studying the degeneracy of the direct kinematic
model. Special cases of self-motions are then examined and the degree of
freedom gained in such special configurations is kinematically interpreted.
Finally, a practical example is discussed and experimental validations
performed on an actual robot prototype are presented
Simulation and analysis of pointto-point differential drive mobile robot
A differential drive robot and Path motion point to point are studied and implemented
in this thesis. The model by the Dudek model on Instantaneous Centre of Curvature is
also discussed. The simulation of the mathematical model of the mobile robot was
carried out in Simulink by using the Differential Drive Forward Kinematics and
Differential Drive Inverse Kinematics blocks to convert between body velocities and
wheel velocities. And use the Differential Drive Simulation block to simulate the pose
given wheel speeds as inputs. Point to point motion was performed to test the
robustness of the controller (0.0) as starting point and (4.4) as final destination and the
results were used to optimize better performance
A Model of Operant Conditioning for Adaptive Obstacle Avoidance
We have recently introduced a self-organizing adaptive neural controller that learns to control movements of a wheeled mobile robot toward stationary or moving targets, even when the robot's kinematics arc unknown, or when they change unexpectedly during operation. The model has been shown to outperform other traditional controllers, especially in noisy environments. This article describes a neural network module for obstacle avoidance that complements our previous work. The obstacle avoidance module is based on a model of classical and operant conditioning first proposed by Grossberg ( 1971). This module learns the patterns of ultrasonic sensor activation that predict collisions as the robot navigates in an unknown cluttered environment. Along with our original low-level controller, this work illustrates the potential of applying biologically inspired neural networks to the areas of adaptive robotics and control.Office of Naval Research (N00014-95-1-0409, Young Investigator Award
Reuleaux: Robot Base Placement by Reachability Analysis
Before beginning any robot task, users must position the robot's base, a task
that now depends entirely on user intuition. While slight perturbation is
tolerable for robots with moveable bases, correcting the problem is imperative
for fixed-base robots if some essential task sections are out of reach. For
mobile manipulation robots, it is necessary to decide on a specific base
position before beginning manipulation tasks.
This paper presents Reuleaux, an open source library for robot reachability
analyses and base placement. It reduces the amount of extra repositioning and
removes the manual work of identifying potential base locations. Based on the
reachability map, base placement locations of a whole robot or only the arm can
be efficiently determined. This can be applied to both statically mounted
robots, where position of the robot and work piece ensure the maximum amount of
work performed, and to mobile robots, where the maximum amount of workable area
can be reached. Solutions are not limited only to vertically constrained
placement, since complicated robotics tasks require the base to be placed at
unique poses based on task demand.
All Reuleaux library methods were tested on different robots of different
specifications and evaluated for tasks in simulation and real world
environment. Evaluation results indicate that Reuleaux had significantly
improved performance than prior existing methods in terms of time-efficiency
and range of applicability.Comment: Submitted to International Conference of Robotic Computing 201
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