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Because mobile manipulators are unable to climb stairs, the elevator operation is a crucial capacity to help those kinds of robot systems work in modern multifloor buildings. Here, the elevator button manipulation is considered as an efficient approach to fulfill that requirement. Previously, some studies presented elevator button recognition algorithms while some others designed schemes for the button manipulation work. However, the mobile robot, the manipulator and the camera in their robot systems are asynchronous. Besides, the time-consuming calibration for the camera is inevitable, especially in changeable environments. This paper aims to present an alternative method for the elevator button manipulation to overcome mentioned shortcomings.

In this paper, the elevator button manipulation is conducted by using the visual-based self-driving mobile manipulator in which the autonomous mobile robot, the manipulator and the camera cooperate more efficiently. Namely, the mobile robot does not need to be located exactly in front of the elevator panel as the manipulator has the ability to adjust the initial frame of the camera based on the system kinematic synchronization. In addition, the proposed method does not require the real world coordinates of elevator buttons, but uniquely using their pixel positions. By doing this, not only is the projection from two-dimensional pixel coordinates to three-dimensional (3D) real world coordinates unnecessary, but also the calibration of the camera is not required.

The proposed method is experimentally verified by using a visual-based self-driving mobile manipulator. This robotic system is the integration of an autonomous mobile robot, a manipulator and a camera mounted on the end-effector of the manipulator.

Because the surface of the elevator button panel is usually mirror-like, the elevator button detection is easily affected by the glare and the brightness of the environmental light condition.

This robot system can be used for the goods delivery or the patrol in modern multifloor buildings.

This paper includes three new features: simultaneously detecting and manipulating elevator buttons without the projection from pixel coordinates to 3D real world coordinates, a kinematic synchronization to help the robot system eliminate accumulated errors and a safe human-like elevator button manipulation.

This paper aims to solve the problems of the synchronization between branches and the uncertainties such as joint friction, load variation and external interference of a hybrid mechanism. The controller is used to improve the synchronization and robustness of the hybrid mechanism system and achieve both finite time convergence and chattering-free sliding mode.

First, the dynamic model of hybrid mechanism containing lumped uncertainties is formulated by the Lagrange method, and a composite error based on coupling synchronization error and the end-effector tracking error is set up in the task space. Then, by combining the finite time super twisting sliding mode control algorithm, a composite error-based finite time super twisting sliding mode synchronous control law is designed to make the end-effector tracking error and coupling synchronization error achieve better tracking performance and convergence performance. Finally, the Lyapunov stability of the control law and the finite-time convergence of the composite error are proved theoretically.

To verify the effectiveness of the proposed control method, simulations and experiments for the prototype system of the hybrid mechanism are conducted. The results show that the proposed control method can achieve better tracking performance and convergence performance.

This is a new innovation for a hybrid mechanism containing lumped uncertainties to improve the robustness, convergence performance, tracking performance and synchronization of the system.

3D printing technology has the characteristics of fast forming and low cost and can manufacture parts with complex structures. At present, it has been widely used in various manufacturing fields. However, traditional 3-axis printing has limitations of the support structure and step effect due to its low degree of freedom. The purpose of this paper is to propose a robotic 3D printing system that can realize support-free printing of parts with complex structures.

A robotic 3D printing system consisting of a 6-degrees of freedom robotic manipulator with a material extrusion system is proposed for multi-axis additive manufacturing applications. And the authors propose an approximation method for the extrusion value E based on the accumulated arc length of the already printed points, which is used to realize the synchronous movement between multiple systems. Compared with the traditional 3-axis printing system, the proposed robotic 3D printing system can provide greater flexibility when printing complex structures and even realize curved layer printing.

Two printing experiments show that compared with traditional 3D printing, a multi-axis 3D printing system saves 47% and 79% of materials, respectively, and the mechanical properties of curved layer printing using a multi-axis 3D printing system are also better than that of 3-axis printing.

This paper shows a simple and effective method to realize the synchronous movement between multiple systems so as to develop a robotic 3D printing system that can realize support-free printing and verifies the feasibility of the system through experiments.

The purpose of this paper, is to solve the problem of finite-time fault-tolerant attitude synchronization and tracking control of multiple rigid bodies in presence of model uncertainty, external disturbances, actuator faults and saturation. It is assumed that the rigid bodies in the formation may encounter loss of effectiveness and/or bias actuator faults.

For the purpose, adaptive terminal sliding mode control and neural network structure are used, and a new sliding surface is proposed to guarantee known finite-time convergence not only at the reaching phase but also on the sliding surface. The sliding surface is then modified using a proposed auxiliary system to maintain stability under actuator saturation.

Assuming that the communication topology between the rigid bodies is governed by an undirected connected graph and the upper bounds on the actuators’ faults, estimation error of model uncertainty and external disturbance are unknown, not only the attitudes of the rigid bodies in the formation are synchronized but also they track the time-varying attitude of a virtual leader. Using Lyapunov stability approach, finite-time stability of the proposed control algorithms demonstrated on the sliding phase as well as the reaching phase. The effectiveness of the proposed algorithm is also validated by simulation.

The proposed controller has the advantage that the need for any fault detection and diagnosis mechanism and the upper bounds information on estimation error and external disturbance is eliminated.

This paper seeks to present an inertial motion tracking system for monitoring movements of human upper limbs in order to support a home‐based rehabilitation scheme in which the recovery of stroke patients' motor function through repetitive exercises needs to be continuously monitored and appropriately evaluated.

Two inertial sensors are placed on the upper and lower arms in order to obtain acceleration and turning rates. Then the position of the upper limbs can be deduced by using the kinematical model of the upper limbs that was designed in the previous paper. The tracking system starts from inertial data acquisition and pre‐filtering, followed by a number of processes such as transformation of coordinate systems of sensor data, and kinematical modelling and optimization of position estimation.

The motion detector using the proposed kinematic model only has drifts in the measurements. Fusion of acceleration and orientation data can effectively solve the drift problem without the involvement of a Kalman filter.

The image rendering is not undertaken when the data sampling is performed. This non‐synchronization is applied in order to avoid the breaks in the continuous sampling.

This new motion detector can work in different environments without significant drifts. Also, this system only deploys two inertial sensors but is able to estimate the position of the wrist, elbow and shoulder joints.

Describes the experience of setting up a cooperative arm system based on individual open‐architecture controllers. Two six‐degree‐of‐freedom industrial manipulators, one of which is mounted on a moving track, are installed to realize a cooperative experimental set‐up. The main issues related to the cooperative manipulation are overviewed and its potential applications in industry are discussed. A brief description of the system’s components is given. The most relevant problems encountered in setting up the cooperative system based on individual control architectures are detailed. The result of the experience is that by using available industrial manipulators, rather than prototypes, and without re‐designing the controller hardware, it is possible to realize a cooperative manipulator system.

This paper aims to present an open-architecture kinematic controller, which was developed for articulated robots, facing the demands of various applications and low cost on robot system.

A general approach to develop this controller is described in hardware and software design. The hardware consists of embedded boards and programable multi-axes controller (PMAC), connected with ethernet, and the software is implemented on a robot operating system with MoveIt!. The authors also developed a teach pendant running as a LAN node to provide a human–machine interface (HMI).

The proposed approach was applied to several real articulated robot systems and was proved to be effective and portable. The proposed controller was compared with several similar systems to verify its integrality and flexibility. The openness of this controller was discussed and is summarized at the end of this paper.

The proposed approach provided an open and low-complex solution for experimental studies in the lab and short-run production in small workshops.

Several contributions are made by the research. The actuation model and communication were implemented to integrate the trajectory planning module and PMAC for setting up the physical interface. Method and program interface based on kinematics was provided to generate various interpolations for trajectory planning. A teach pedant with HMI was developed for controlling and programing the robot.

The paper describes a prototype robot which due to its serial‐parallel structure exhibits, high stiffness and has a large work envelope. These features make this robot suitable for relatively high precision machining operations on large workpieces. The conroller for this robot was based on MRROC++, which is a robot programming framework. Thus the controller could be tailored to the tasks at hand, including the capability of in‐program switching of kinematic model parameters. To obtain those parameters for different locations in the work‐space a calibration procedure using linear measurement guides has been devised.

The purpose of this paper is to present a novel computational framework capable of simulating the block cave phenomenon of fines migration in two dimensions. Fines migration is characterised by the faster movement of fine and often low‐grade material towards the draw point in comparison to larger, blocky material. A greater understanding of the kinematic behaviour of fines and ore within the cave during draw is integral to the solution of this problem.

The lattice Boltzmann method (LBM) is employed in a nonlinear form to represent the fines as a continuum, and it is coupled to the discrete element method (DEM) which is used to represent large blocks. The issues relevant to this approach, such as fluid‐solid interaction, the synchronisation of explicit schemes, and the characterisation of a bulk material as a non‐Newtonian fluid are discussed.

Results of the 2D simulations reveal migration trends for the geometries, material properties and operational sequences analysed. By executing an extensive programme of numerical experiments the influence of these and other relevant block cave factors on the migration of fines could be isolated.

To the authors' knowledge, this is the first time the LBM has been used to simulate the flow of bulk materials. The non‐Newtonian LBM‐DEM framework is also a novel approach to the investigation of fines migration, which until now has been limited to scale models, cellular automata or pure DEM simulations. The results of the 2D migration analyses highlight the potential for this novel approach to be applied in an industrial context and also encourage the extension of the framework to 3D.

To present an open architecture for real‐time sensory feedback control of a dual‐arm industrial robotic cell. The setup is composed of two industrial robot manipulators equipped with force/torque sensors and pneumatic grippers, a vision system and a belt conveyor.

The original industrial robot controllers have been replaced by a single PC with software running under a real‐time variant of the Linux operative system.

The new control architecture allows advanced control schemes to be developed and tested for the single robots and for the dual‐arm robotic cell, including force control and visual servoing tasks.

An advanced user interface and a simulation environment have been developed, which permit fast, safe and reliable prototyping of planning and control algorithms.