Purpose – The purpose of this paper is to propose a screw axis identification (SAI) method based on the product of exponentials (POE) model, which is concerned with calibrating a serial robot with m joints equipped with a stereo-camera vision system. Design/methodology/approach – Different from conventional approaches, like the circle point analysis (CPA) or the system theoretic method which mu...

This paper discusses methods for visualising the workspace of a generic robot using the colour space to indicate orientation and dexterity of the tool. A method is shown to convert Euler angles into a RGB colour representation. An alternative method for examining generic workspace quality based on dexiterity is also shown. These methods are then applied to selected examples.

Space manipulator systems having spacecraft actuators turned off, operate in free-floating mode, and exhibit nonholonomic behaviour due to angular momentum conservation. The system is underactuated and a challenging problem is to control both the location of the end effector and the attitude of the base, using manipulator actuators only. A developed path planning method that perform this task i...

This paper addresses the problem of grasping and manipulating three-dimensional objects with a reconngurable gripper equipped with two parallel plates whose distance can be adjusted by a computer-controlled actuator. The bottom plate is a bare plane, and the top one carries a rectangular grid of actuated pins that can translate in discrete increments under computer control. We propose to use th...

In this paper we present a method to control the displacement of a robot arm with no proprioceptive sensor. The joint positions are not available and this manipulator is usually open-loop controlled. In order to get a more efficient control interface, we propose a closed-loop system based on an eye-to-hand visual servoing approach. We show that, using such an approach, measurements of the manip...

The study of manipulation problem with application of a new gripper designed, constructed and built by the author is presented in the paper. The design work concentated on ensuring that the hand can contact with a variety of different shape objects made of flexible materials of different properties as well as fragile objects requiring particular caution when manipulated. Additionally it was ass...

The stability of holonomic mobile manipulator can be improved effectively based on the stability twist constraint (STC). However, nonholonomic mobile manipulators are much more popular. In this paper, the stability of a nonholonomic mobile manipulator is improved with STC consideration. However, the constraint of nonholonomic mobility will affect the orientation of mobile base. Numerical simula...

A key issue in robotics is the development of the ability to grasp unknown objects. This ability requires a grasp determination mechanism that, based on the analysis of the description of the object, determines how it can be stably grasped. In this paper, a grasp determination method is presented that computes a set of grasps that comply with the force-closure condition. Its input is a set of c...

In this article, we present the kinematic calibration of a H4 parallel robot using a vision-based measuring device. Calibration is performed according to the inverse kinematic model method, using first the design model then a model developed for calibration purpose. To do so, the end-effector pose has to be measured with the utterst accuracy. Thus, we first evaluate the practical accuracy of ou...

In this paper, the kinematic synthesis of a four-link mechanism with rolling contacts is investigated. This mechanism comprises a two-fingered gripper and a grasped object. The synthesis equations used for motion generation and function generation are established. The number of free choices in design variables for the kinematic synthesis is also discussed. Furthermore, the optimization-based nu...