Development and Kinematic Position Analysis of a Novel Class 2 Tensegrity Robot

This paper presents a novel class 2 tensegrity robot which has contact between its rigid elements with a universal joint. Also, an strategy to obtain the forward and inverse position kinematic analysis using the parameters Denavit–Hartenberg in the distal convention is presented, obtaining the closed–form solution for the inverse position analysis and it was validated through simulation where a point of the robot followed the desired trajectory. Finally, the results were implemented in the experimental prototype of the novel class 2 tensegrity robot.

Kinematics and Transmission Performance Analyses of a 2T2R Type 4-DOF Spatial Parallel Manipulator

A 2-RPU&2-SPS spatial parallel mechanism (SPM) is researched. Firstly, the number and property of degrees of freedom (DOF) of the SPM are analyzed by screw theory. There are two rotational and two translational movements (2R2T) of the mechanism that can be achieved. Secondly, the position analyses are researched. For the inverse position analysis, the explicit expression can be obtained from the independent motion parameters of the given mechanism, and the forward position problem is solved by calculating a set of nonlinear equation systems. Then we obtained the workspace of the mechanism based on the analytic formulae of the inverse displacement. Finally, by establishing the Jacobian matrix of the mechanism, the singularity of the mechanism is obtained, and the kinematics transmission performance of the mechanism is studied by using the index of the output efficiency of the limb output of the mechanism. This work will provide the theoretical basis for prototype development and application of the mechanism.

A new numerical algorithm for the inverse position analysis of all serial manipulators

A new fast successive approximation algorithm for the solution of the inverse position analysis of a general serial manipulator is presented. With the algorithm, we can search out the inverse solution of the serial manipulator quickly under the desired precision when the position of the three non-collinear end effector points is given. The position analysis of the 7R redundant serial manipulator is illustrated in the literature as an example. The simulation results verify the efficiency of the proposed algorithm. Since the three non-collinear end effector points can be selected at random, the algorithm can be applied to any other type serial manipulator.

Inverse position analysis, workspace determination and position synthesis of parallel manipulators with 3-RSR topology

Manipulators with 3-RSR topology are three-degree-of-freedom parallel manipulators that may be either spherical or mixed-motion manipulators. The inverse position analysis (IPA) and the workspace determination of 3-RSR manipulators are addressed by means of a new approach. The new approach is centered on a particular form of the closure equations called compatibility equations. The compatibility equations contain only the six coordinates (end-effector coordinates) which locates the end-effector pose (position and orientation) with respect to the frame, and the geometric constants of the manipulator. When the manipulator geometry is assigned, the common solutions of the compatibility equations are the end-effector coordinates which identify the end-effector poses belonging to the manipulator workspace. Moreover, they can be the starting point to easily solve the IPA. The presented compatibility equations can be also used to solve the position synthesis of the 3-RSR manipulator. This way of solving the position synthesis will demonstrate that only approximated solutions exist when more than eight end-effector poses are given.

An inverse position analysis of five-bar planar parallel manipulators

In this paper, we present a simple method to obtain joint inputs needed to attain any point in the reachable workspace of a class of five-bar planar parallel manipulators which are based on five rigid links and five single degree of freedom joints – revolute and prismatic joints. Depending on the topology of the manipulators, two mathematical expressions describing the path traced by the tip of two links connected to each other are obtained and solved simultaneously in order to determine the intersection points of the two paths which are the Cartesian coordinates of the connection points for the links. For the class of manipulators considered in this study, one of the links is the link activated by an actuator fixed to the ground. So, rotational and/or translational joint inputs can be determined from the Cartesian coordinates of the tip of the activated links. Sylvester's dialytic elimination method is employed to solve the equations. Such a methodology is easy to implement, computationally efficient and sound to compute all possible solutions. A numerical example is provided for each manipulator and the inverse position solutions are verified by substituting them into forward position equations. It is concluded that the proposed method is useful in trajectory planning and control of five-bar planar parallel manipulators in joint space.

Position Analysis in Analytical Form of the 3-PSP Mechanism

In this paper the direct and the inverse position analysis of a 3-dof fully-parallel mechanism, known as 3-PSP mechanism, is addressed and solved in analytical form. The 3-PSP mechanism consists of two rigid bodies, one movable (platform) and the other fixed (base), connected to each other by means of three equal serial kinematic chains (legs) of type PSP, P and S standing for prismatic and spherical pair respectively. Both the direct and the inverse position analysis of this mechanism lead to non-linear equations that are difficult to solve. In particular, the inverse position analysis comprises different sub-problems which need specific solution techniques. Finally a numerical example is reported.

A successive approximation algorithm for the inverse position analysis of serial manipulators

A new numerical method for the solution of the inverse position analysis of serial manipulators is presented. The main feature of the method that makes it attractive with respect to the method available in the literature, is its ability to search out the inverse solution of any precision quickly.

Position Analysis in Analytical Form of the 3-PSP Mechanism

In this paper the direct and the inverse position analysis of a 3-dof fully-parallel mechanism, known as 3-PSP mechanism, is addressed and solved in analytical form. The 3-PSP mechanism consists of two rigid bodies, one movable (platform) and the other fixed (base), connected to each other by means of three equal serial kinematic chains (legs) of type PSP, P and S standing for prismatic and spherical pair respectively. Both the direct and the inverse position analysis of this mechanism lead to nonlinear equations that are difficult to solve. In particular, the inverse position analysis comprises different subproblems which need specific solution techniques. Finally a numerical example is reported.