An analytical method is presented to obtain all surfaces enveloping the workspace of a general n degree-of-freedom mechanism with non-unilateral constraints. The method is applicable to kinematic chains that can be modeled using the Denavit-Hartenberg representation method for serial kinematic chains or its modification for closed-loop kinematic chains. The method developed is based upon analytical criteria for determining singular behavior of the mechanism. Singularities of manipulators with non-unilateral constraints have never been reported. The complete mathematical formulation is presented and illustrated using 4 & 5 DOF spatial manipulators. Four types of singularities are classified: Type I sets are position Jacobian singularities; Type II sets are instantaneous singularities that are due to a generalized joint are reaching its apex; Type III sets are domain boundary singularities, which are associated with the time initial and final values of the time interval; Type IV sets are coupled singularities, which are associated with a relative singular Jacobian, where the null space is reduced in one submatrix due to either of two occurrences: a Type II and Type III singularities.

Parallel kinematic machines (PKMs) and, in particular linapods, are being increasingly used in the industrial workplace. The complex control required for various linapod kinematics, each having different numbers and types of Degrees-of-Freedom (DOF), require corresponding transformations to be generated. This paper introduces a general form of transformation that can be adapted to a wide range of linapods. The approach is illustrated by an example and the concept of a five-DOF linapod for the milling process is proposed. Furthermore, the advantages from the two types of three-DOF Linapods are discussed, and it is shown how the position accuracy can be increased.

An auto-bonding robot (ABR) that consists of the mechanism of adhesive dispensing and auto-bonding, a pneumatic system and a control system, is presented in this paper. It is designed for the bonding operation of cover-glasses and space solar cells using adhesives. An adhesive dispensing method is proposed to control the thickness and position of the adhesive layer on solar cells and to provide a satisfactory bonding accuracy. The bubble-free bonding process is realized by the leaning mechanism of a pneumatic sucker. Experimental comparison of the manual and automatic bonding methods showed that there are no fragment and air bubbles between the cover-glass and the space solar cell, and no outflow adhesive on the surface by the automatic bonding process in a non-vacuum condition. The novel automatic bonding robot greatly improved the lightweight space solar cells bonding quality and production rate.

A planar underactuated bipedal robot with an impulsive foot model is considered. The analysis extends previous work on a model with unactuated point feet of Westervelt et al. to include the actuator model of Kuo. The impulsive actuator at each leg end is active only during the double support phase, which results in the model being identical to the model with unactuated point feet for the single support phase. However, the impulsive foot actuation results in a different model for the double support map. Conditions for the existence of a hybrid zero dynamics for the robot with foot actuation are studied. A feedback design method is proposed that integrates actuation in the single and double support phases. A stability analysis is performed using a Poincaré return map. As in Kuo's model, a more efficient gait is demonstrated with an impulsive foot action.

Underwater Modular Self-Reconfigurable (UMSR) robots, made up of many identical modules, can adjust their configurations to multiple underwater environments or tasks. They can be used in many complex underwater occasions where the ROVs/AUVs can't work well. However, their reconfiguration is difficult because this has to involve many connection adding and removing operations which are difficult to be executed in the underwater environment. To reduce the times of these operations, we propose the theory of Topological Transformation (TT), which includes some definitions in TT, the basic approach to TT, and the Genetic Algorithm (GA) based solution for the optimal TT.

This paper describes a simulation model for a multi-legged locomotion system with joints at the legs having viscous friction, flexibility and backlash. For that objective the robot prescribed motion is characterized in terms of several locomotion variables. Moreover, the robot body is divided into several segments in order to emulate the behaviour of an animal spine. The foot-ground interaction is modelled through a non-linear spring-dashpot system whose parameters are extracted from the studies on soil mechanics. To conclude, the performance of the developed simulation model is evaluated through a set of experiments while the robot leg joints are controlled using fractional order algorithms.

In this work, the elementary task of controlling the contact of a one degree-of-freedom (dof) robot with a compliant surface is modeled as a switched system. A position controller is used for the free motion and a force controller for the contact task and the goal is to stabilize the robot in contact with the spring-like environment while exerting a desired force. As the robot makes or breaks contact, the control law switches accordingly and the aim is to examine the system's stability using ideas from hybrid stability theory. By considering typical candidate Lyapunov functions for each of the two discrete system states, conditions on feedback gains are derived that guarantee Lyapunov stability of the hybrid task. It is shown that conditions can be decoupled with respect to the discrete state only when the more general hybrid stability theorems are used.

Cooperative robots are usually required in flexible manufacturing systems or complex working environments. In particular, when an object under processing is too big or too heavy, a single robot may not be enough to handle it. Two or more manipulators are to be used in such a case. This paper presents the study of the dynamic equations for two industrial robots holding a rigid object. To this end, holonomic constraints are combined with the manipulators and object equations of motion to obtain the dynamic model of the whole system, which can be used for simulation purposes. Experimental results are presented to validate the theoretical results.

In this paper, the problem of precision reaching applications in robotic systems for scenarios with static and non-static objects has been considered and a solution based on a modular neural architecture has been proposed and implemented. The goal of this solution is to combine robustness and capability mapping trajectories from two biologically plausible neural network sub-modules: Hyper RBF and AVITE. The Hyper Basis Radial Function (HypRBF) neural network solves the inverse kinematic in redundant robotic systems, while the Adaptive Vector Integration to End-Point (AVITE) visuo-motor neural model quickly maps the difference vector between current and desired position in both spatial (visual information) and motor coordinates (propioceptive information). The anthropomorphic behaviour of the proposed architecture for reaching and tracking tasks in presence of spatial perturbations has been validated over a real arm-head robotic platform.

An adaptive fuzzy sliding control scheme is proposed to control a passive robotic manipulator. The motivation for the design of the adaptive fuzzy sliding controller is to eliminate the chattering and the requirement of pre-knowledge on bounds of error associated with the conventional sliding control. The stability and convergence of the adaptive fuzzy sliding controller is proven both theoretically and practically by simulations. A three-link passive manipulator model with two unactuated joints is derived to be used in the simulations. Simulation results demonstrate that the proposed system is robust against structured and unstructured uncertainties.

This paper describes external camera-based shape estimation for continuum robots. Continuum robots have a continuous backbone made of sections which bend to produce changes of configuration. A major difficulty with continuum robots is the determination of the robot's shape, as there are no discrete joints. This paper presents a method for shape determination based on machine vision. Using an engineered environment and image processing from a high speed camera, shape determination of a continuum robot is achieved. Experimental results showing the effectiveness of the technique on our Elephant's Trunk Manipulator are presented.

For many biological creatures sensory whiskers are an effective means of detecting and recognising nearby objects. The project described in this paper has the aim of demonstrating that whisker sensors can be used as a similarly effective form of robot sensing. Many mobile robots have used whiskers as simple switches to warn of an imminent collision. However, these devices cannot provide the detailed surface profile information required to recognise and accurately locate objects. Several research groups have built advanced whisker sensors that can determine the position of a contact along the length of the whisker. Although these whisker sensors are usually little more than a length of flexible spring material they do require complex sensing and actuation mechanisms at the whisker root. In this project an array of eight whisker sensors is scanned over external objects by the motion of the robot. The resulting deflection of the whiskers is monitored by a potentiometer at each whisker root. By recording the deflection of the whiskers as they slide over external objects sequences of surface points can be determined. Object recognition algorithms have been developed that allow the robot to recognise, grasp and retrieve a range of objects using the whisker data. In this paper the robot, WhiskerBOT, is described together with the object recognition and localisation algorithms. Results of practical experiments are also presented.