Automation in Horticulture:: Design and Evaluation of a Cost-Effective Parallel Robot Arm

This thesis presents the conceptual development of an innovative parallel manipulator that leverages the beneficial attributes of parallel kinematic structures. These attributes include increased stiffness, uniform load distribution, and reduced moving mass, which are strategically incorporated into the design to enhance resource efficiency....

Design and Validation of a 3-DoF Wrist Perturbator Based on an Inverted Spatial Redundant 4-RUU Parallel Manipulator

Humans vary the stiffness in their joints depending on tasks and circumstances. For posture control a high joint stiffness is required to withstand perturbations, whereas for force control a low joint stiffness is required. To investigate how humans vary their joint stiffness precisely for moving an arm, a wearable device is needed that can...

Dynamic Analysis and Trajectory Tracking Control for a Parallel Manipulator with Joint Friction

To overcome the bearing capacity deficiencies of traditional serial hip joint simulators, complex trajectory simulation, among others, as well as a parallel manipulator with two pairs of artificial hip joints and two moving platforms are proposed. The movements and driving forces of the parallel manipulator under the required motion and loading...

Kinematic design of a non-parasitic 2R1T parallel mechanism with remote center of motion to be used in minimally invasive surgery applications

In minimally invasive surgery applications, the use of robotic manipulators is becoming more and more common to enhance the precision of the operations and post-operative processes. Such operations are often performed through an incision port (a pivot point) on the patient's body. Since the end-effector (the handled surgical tool) move about...

Jacobian-based natural frequency analysis of parallel manipulators

The dynamic performance of a parallel manipulator is often limited by its natural frequencies. These frequencies are a result of the controlled actuator stiffness and the mechanical design. Typically, only the lowest natural frequencies are of interest. However, existing methods to analyze natural frequencies of parallel manipulators with...

A screw based methodology for instantaneous dynamic balance

Fast-moving industrial robots exert large varying reaction forces and moments on their base frame, inducing vibrations, wear and accuracy degeneration. These shaking forces and moments can be eliminated by a specific design of the mass distribution of the robot links, resulting in a dynamically balanced mechanism. Obtaining the conditions for...

End effector admittance control of parallel manipulators without force sensor

A telemanipulation system lets a human operator manipulate an environment on distance, using a master and a slave device, which are connected by a bilateral controller that controls the master and the slave device and provides the communication between these devices. The master device is manipulated by the operator and these actions are...

Integrated Stiffness Analysis of Redundant Parallel Manipulator Based on Finite Element Method

An integrated stiffness model is established for a Planar Parallel Manipulator (PPM) with actuation redundancy based on Finite Element Method (FEM), and the static stiffness, dynamitic stiffness and moving stiffness of the PPM are analyzed according to the integrated stiffness model. Firstly, a dynamic model of flexible plane beam element is...

Forward Kinematic Analysis of Tip-Tilt-Piston Parallel Manipulator using Secant-Bootstrap Method

This paper, deals with application of the Secant-Bootstrap Method (SBM) to solve the Closed-form forward kinematics of a new three degree-of-freedom (DOF) parallel manipulator with inextensible limbs and base-mounted actuators. The manipulator has higher resolution and precision than the existing three DOF mechanisms with extensible limbs. This...

Workspace Optimization of 3SPS+1PS Parallel Hip Joint Simulator