4 research outputs found
Kinematic Analysis and Trajectory Planning of the Orthoglide 5-axis
The subject of this paper is about the kinematic analysis and the trajectory
planning of the Orthoglide 5-axis. The Orthoglide 5-axis a five degrees of
freedom parallel kinematic machine developed at IRCCyN and is made up of a
hybrid architecture, namely, a three degrees of freedom translational parallel
manip-ulator mounted in series with a two degrees of freedom parallel spherical
wrist. The simpler the kinematic modeling of the Or-thoglide 5-axis, the higher
the maximum frequency of its control loop. Indeed, the control loop of a
parallel kinematic machine should be computed with a high frequency, i.e.,
higher than 1.5 MHz, in order the manipulator to be able to reach high speed
motions with a good accuracy. Accordingly, the direct and inverse kinematic
models of the Orthoglide 5-axis, its inverse kine-matic Jacobian matrix and the
first derivative of the latter with respect to time are expressed in this
paper. It appears that the kinematic model of the manipulator under study can
be written in a quadratic form due to the hybrid architecture of the Orthoglide
5-axis. As illustrative examples, the profiles of the actuated joint angles
(lengths), velocities and accelerations that are used in the control loop of
the robot are traced for two test trajectories.Comment: Appears in International Design Engineering Technical Conferences \&
Computers and Information in Engineering Conference, Aug 2015, Boston, United
States. 201
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
The 3-PPPS parallel robot with U-shape Base, a 6-DOF parallel robot with simple kinematics
International audienceOne of the main problems associated with the use of 6 DOF parallel robots remains the solving of their kinematic models. This is rarely possible to analytically solve their models thereby justifying the application of numerical methods. These methods are difficult to implement in an industrial controller and can cause solution bifurcations close to singularities resulting in following an unplanned trajectory. Recently, a 3-PPPS robot with U-shaped base was introduced where an analytical kinematic model can be derived. Previously, quaternion parameters were used to represent the orientation of the mobile platform. To allow for simpler model handling, this article introduces the use of Euler angles which have a physical meaning for the users. Compact writing of the direct and inverse kinematic model is thus obtained. Using algebraic and cylindrical decomposition for the workspace, this provides a simpler representation of the largest domain without singularity around the " home " configuration