Haptic Guidance in a Collaborative Robotic System

As full automation is often not achievable in flexible production, collaborative robot systems offer potential for an increase in productivity for manual systems. These systems however pose great challenges concerning planning and engineering. We define main requirements for industrial human robot collaboration simulation. It is found that current simulation systems in research and industry cannot sufficiently support the digital planning of such systems. We introduce a framework for a human-in-the-loop system capable of simulation and virtual commissioning of industrial collaborative robot systems. For this, we implement a combined virtual reality, motion capturing and object tracking architecture into an industry standard robot simulation software. We validate our system on real use cases from power electronics production implementing real safety controllers and evaluate the fulfillment of the defined requirements.

The ROSA (Robotic Surgical Assistant) Knee system (Zimmer Biomet, Warsaw, IN) for total knee arthroplasty (TKA) can be considered as collaborative robotics, where the surgeon remains in charge of the procedure and collaborates with a smart robotic tool, to perform the surgery with a high accuracy and reproducibility. The aim was to describe: (1) its concept and surgical technique; (2) its advantages and potential limits; (3) the early experience with this system. The goal during its development phase was to keep the surgeon active and at the center of the operation: the surgeon handles the saw and performs the cuts while the robotic arm places and holds the guide at the right place. The ROSA knee platform assists the surgeon for the distal femoral cut, the femoral component sizing and positioning, the tibial cut and the ligament balance. This robotic system has two options: image-based with 3D virtual model; or image-less, based on intraoperative landmarks acquisition. All the classic surgical techniques can be used: measured resection, gap balancing, functional alignment, kinematic alignment. Some techniques recently developed are more ROSA-specific: Robotic personalized TKA, ROSA-FuZion technique. Its advantages as compared to other available systems include: radiographs in standing position, collaborative robotic system where the robot completes the surgeon skills, "off-the-shelf" implants, predictive robotic with concept of machine learning incorporated into the system. Two cadaveric studies have reported the high accuracy and reproducibility of this device. This robotic system is recent and currently no clinical series has enough follow-up to report clinical outcomes. The ROSA knee system is a robotically assisted semi-autonomous surgical system with some specific characteristics. The aim of this collaborative robotic system is to improve the accuracy and reliability of the bone resections and the ligament balancing, without replacing the steps well performed by the surgeon.

A promising direction in the development of robotics is collaborative robotics under control of artificial intelligence systems. Such socio-cyber-physical systems are able to provide a synergistic effect in implementation of weakly determined technological processes. Nevertheless, there is a low degree of efficiency of known methods for integrating human factor models within robotic process` digital twin, as well as the lack of unified methodologies for developing models themselves that describe human condition and its impact on technological process key indicators. As part of the study, the tasks of forming theoretical foundations, methodologies and applied implementations aimed at increasing attractiveness of collaborative solutions for industrial enterprises are set. The result is achieved by improving quality and degree of integration of human factors models into robotic process` digital twins. An idea is proposed that consists in building a socio-cyber-physical system based on cobot models and a human factor model in context of "subject-subject" interaction, which will allow delegating more management functions to the ICS and provide greater flexibility for intelligent process control and an increased degree of robustness to an unfavorable state manifestation person. A conceptual model of the human factor and a prototype model of interaction between robot and operator are proposed. The mathematical model will allow taking into account toperator current state when designing a response to a disturbance, maintaining the high-level quality of collaborative production process. Software architecture elements and procedure for organizing the modes of operation of the ICS are presented.

Robotics in Simulated COVID-19 Patient Room for Health Care Worker Effector Tasks: Preliminary, Feasibility Experiments

Аннотация. В работе сформирован ряд предложений по совершенствованию разработанного алгоритма для распределения работ в коллаборативной робототехнической системе (КРТС) и назначения участников КРТС на выполнение операций технологического процесса. Реализован учет пространственной модели рабочего пространства (размещения рабочих мест), изменения объекта воздействия (изделия) и использования дополнительных ресурсов, случайного поведения и ошибок людей, накопления усталости и снижения эффективности их работы со временем, а также динамического переназначения участников КРТС на выполнение операции в случае внезапного выхода из строя кобота или потери трудоспособности человеком. Также предложен модифицированный алгоритм минимизации целевой функции (решения оптимизационной задачи) на этапе подбора состава и назначения исполнителей на выполнение операции, учитывающий значения эффективности доступных участников КРТС и минимизирующий их состав.

The use of collaborative robots in the industrial domain has significantly grown in the last years, allowing humans to operate in the same workspace occupied by robots without any physical barriers. Understandably, the safety of the human operator has been a major concern both for researchers and regulatory bodies. The power and force limited modality of robots is of particular interest in that sense, being used in order to bound the energy of eventual collisions when a close physical interaction with humans is necessary. Such an interaction modality allows the robotic system to operate without the use of barriers, but a measurement of the force and pressure occurring due to a contact must be provided as part of the risk assessment. However, the precise procedure to follow in order to reliably provide such measures is still unclear for users and system integrators willing to self-assess the safety of their own collaborative robotic system. In this work, the repeatability and reliability of such testing procedures and measures are analyzed with an interlaboratory comparison approach, with the aim to establish the degree of variability possibly encountered when performing the same test under slightly different conditions.

Problem-Solving Skill Development in Learning Factories Through Collaborative Robotic Systems

Modern flexible production systems benefit from collaborative robot systems that support to teach robot configurations by hand to quickly implement collision-free motions. However, appropriate interpolation schemes that allow a fast and smooth motion through this sequence of waypoints is often not part of robot control systems. Instead, only point-to-point motions or a set of predefined curves like circular motions are supported. We propose an approach to improve the efficiency of finding a time parameterization with cubic splines that computes minimum trajectory durations while respecting actuator limits and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$C^2$</tex-math></inline-formula> -continuity. Compared to the existing method, our contribution consists in the analytical gradients of the underlying nonlinear optimization problem and thus we are able to propose an efficient solution approach using state-of-the-art optimization solvers. We validate our implementation in simulation and in experiments, and benchmark it with the three trajectory generation methods implemented in <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">MoveIt!</i> .

Mobile manipulator is a robot for the next generation of processes. The mobile manipulator can increase process efficiency by being combined with the collaborative robot system. However, due to worker safety issues, simultaneous control of the mobile manipulator is still difficult. In this paper, we present the designing path of collision avoidance of a mobile manipulator for the safety of workers. By monitoring the position and velocity of a worker modeled as a cylinder, the mobile manipulator designs a path to avoid the worker using reinforcement learning. We learned the robot using simulation, and we checked the mobile and manipulator move to the destination by avoiding the worker.

The aim of this paper is to develop a robotic system which can navigate in an indoor environment and charge several electrical devices. Several algorithms such as Travel Salesman Problem, Probabilistic Roadmap and Fuzzy C-means Clustering are used for development of such a system. The testbed is constructed by Arduino Uno, Arduino WIFI Shield, Go-between Shield by Mayhew Lab and Polulu Zumo robot for Arduino Ver.1.2. All the algorithms are coded by MathWorks MATLAB and Simulink. The core of the wireless charging robot is to optimize the best performance for single robot to charge multiple devices. Owing to the computation restriction of the mobile robot, the calculation will be done on remote server and communicate with the robot through Wi-Fi connection. By this, the computation load on mobile robot can be reduced as well as improving the efficiency. A real-time feedback system is also built to promote accuracy in actual environment. After the development of improved stability and flexibility, the robot can be brought to real life as an interactive and collaborative robotic system.

The paper presents an angular velocity controller for the pneumatic soft robotic gloves which are applied to medical hand rehabilitation and performance augmentation. In order to configure the reliable control parameters, linear dynamic second-order state-space models of five robotic digits were identified by the experimental data. Using the identified models, proportional-integral (PI) control parameters were tuned by simulation studies. The tuned PI parameters were verified by experiment, which demonstrates that the system identification and simulation studies are reliable and can reduce the manual tuning time and prevent tuning hardware wear.

A velocity controller for a permanent magnet linear synchronous motor (PMLSM) is designed using a brain emotional learning based intelligent control (BELBIC). This is performed for a comprehensive nonlinear model of PMLSM including non-idealities such as detent force, parameter uncertainty, unpredicted disturbance, and nonlinear friction. As an evaluation criterion of the performance of the proposed method, a proportional - integral (PI) controller is designed whose parameters are optimally tuned by the particle Swarm Optimization (PSO) algorithm for better comparison.

Low force ripples from permanent magnet linear motors (PMLMs) are typically essential requirements in a wide range of demanding control applications with high motion quality. Apart from the sources present in rotary PM machines, phase unbalance due to the end effect is another major contributor of the thrust force ripples in the PMLMs. In this paper, the phase unbalance and induced force ripples are investigated in the case of a planar PMLM typically equipped with single-layer concentrated windings and quasi-Halbach magnets. It demonstrates that although the PMLM is quite carefully deigned to minimize the end effect, the phase unbalance still exists, including both the amplitude and phase position unbalances. And the phase unbalances give rise to even order force ripple harmonics, in which the 2^nd-order force ripple is particularly significant. In order to compensate the end effect and the unbalance between the three phases, a novel PMLM topology is presented, in which the width of the two end teeth (instead of the edge teeth) is adjusted to reduce the force ripple. And the impact of the end teeth width on the ripple force magnitude is further revealed. It is shown that by proper design of the end teeth width, the 2^nd-order force ripple of the PMLM can be minimized to quite a low extent. In comparison with the original design, the 2^nd-order force ripple factor of the novel topology has been suppressed from 0.4&#x0025; to less than 0.03&#x0025; in the case study. Such a technique has provided a new way of force ripple minimization, and is applicable to other types of linear motors or actuators with appropriate changes.

This paper deals with deflection sensing for robotic control via high speed vision system. Marker is attached to the end effector of the 3-DoF robot arm and the robot is moved to satisfy a line trajectory of the end effector. The motion of the marker attached to the end effector is recorded using the high speed vision system and actual position of the end effector is calculated via image processing of recorded high-frame rate images. We found maximum 1.8 mm position error from the image processing results. We verify that deflection and vibration can be measured by comparing the actual position obtained from image and the ideal position of trajectory planning.

This paper proposes an improved state-dependent Riccati equation (SDRE) attitude control approach which is applied to an unmanned helicopter (UMH) through a multi-timescale structure. To deal with inherent unstable internal dynamics, the flapping and rotational dynamics of the helicopter are organized into a two-timescale nonlinear model. To overcome the problem that a number of terms can't be accounted in the SDRE design, we employ a nonlinear feedforward compensator that is designed to match the vehicle response to the model used in the SDRE design. To overcome the feedforward compensator's disadvantage of being directly affected by parametric disturbances, we improved the design method and added a proportion+ integral (PI) controller of altitude angle and rotation velocity. The simulation results show satisfactory tracking performance of the designed control system.