Kinematics

About: Kinematics is a research topic. Over the lifetime, 30809 publications have been published within this topic receiving 527006 citations.

The kinematic synthesis of a spatial, hyper-redundant system based on binary electromagnetic actuators

Abstract: Flexible endoscopes are a common instrument for different tasks in minimally invasive surgery. The motion and capability of resistance against manipulation forces of common endoscopes is restricted due to their flexibility. They tend to form loops and stress their surroundings. This paper proposes an active shaft concept based on a new actuation concept: the shaft is a hyper-redundant snake-like robot with binary electromagnetic actuators. This system combines good path following capabilities through actively controlling the whole endoscope body with good resistance with respect to manipulation forces through electromagnetism. The functional concept is presented and the influence of design parameters on kinematic characteristics such as workspace and radius of curvature is evaluated. Additionally, a set of kinematic design parameters is synthesized by minimizing the contouring error. Therefore, a path fitting algorithm is proposed.

Modelling and control of the motion of a riderless bicycle rolling on a moving plane

Abstract: This work deals with the modelling and control of a riderless bicycle rolling on a moving plane. It is assumed here that the bicycle is controlled by a pedalling torque, a directional torque and by a rotor mounted on the crossbar that generates a tilting torque. In particular, a kinematic model of the bicycle's motion is derived by using its dynamic model. Then, using this kinematic model, the expressions for the applied torques are obtained.

Task-constrained motion planning for underactuated robots

Abstract: This paper addresses the motion planning problem in the presence of obstacles for underactuated robots that are assigned a geometric task. It is assumed that the robot is subject to kinematic (joint limits, joint velocity bounds) as well as dynamic (torque bounds) constraints. Building on our previous work on task-constrained motion planning, we describe a randomized planner that works directly at the torque level and generates solutions by separating geometric motions from time history. The effectiveness of the proposed approach is shown by planning collision-free swing-up maneuvers for a Pendubot system.

Recursive kinematic propagation for wheeled mobile robots

Abstract: The problem of wheeled mobile robot kinematics is formulated using the transport theorem of vector algebra. Doing so postpones the introduction of coordinates until after the expressions for the relevant Jacobians have been derived. This approach simplifies the derivation while also providing the solution to the general case in 3D, including motion over rolling terrain. Angular velocity remains explicit rather than encoded as the time derivative of a rotation matrix. The equations are derived and can be implemented recursively using a single equation that applies to all cases. Acceleration kinematics are uniquely derivable in reasonable effort. The recursive formulation also leads to efficient computer implementations that reflect the modularity of real mechanisms.