scholarly journals An Online Trajectory Generator on SE(3) for Human–Robot Collaboration

Robotica ◽  
2019 ◽  
Vol 38 (10) ◽  
pp. 1756-1777 ◽  
Author(s):  
Gerold Huber ◽  
Dirk Wollherr
Keyword(s):  
Real Time ◽  
Robot Dynamics ◽  
Safety Standard ◽  
Hardware Platform ◽  
Increasing Demand ◽  
Human Robot Collaboration ◽  
Trajectory Generator ◽  
Rotation Dynamics

SummaryWith the increasing demand for humans and robots to collaborate in a joint workspace, it is essential that robots react and adapt instantaneously to unforeseen events to ensure safety. Constraining robot dynamics directly on SE(3), that is, the group of 3D translation and rotation, is essential to comply with the emerging Human–Robot Collaboration (HRC) safety standard ISO/TS 15066. We argue that limiting coordinate-independent magnitudes of physical dynamic quantities at the same time allows more intuitive constraint definitions. We present the first real-time capable online trajectory generator that constrains translational and rotational magnitude values of 3D translation and 3D rotation dynamics in a singularity-free formulation. Simulations as well as experiments on a hardware platform show the utility in HRC contexts.

Real-Time Trajectory Generation and Reachability Determination in Autorotative Flare

2020 ◽  
Vol 65 (3) ◽  
pp. 1-17
Author(s):  
Brian F. Eberle ◽  
Jonathan D. Rogers
Keyword(s):  
Real Time ◽  
Trajectory Generation ◽  
Contact Theory ◽  
Simulation Environment ◽  
Order Model ◽  
Landing Point ◽  
Overall Performance ◽  
Simulation Results ◽  
Six Degree Of Freedom ◽  
Trajectory Generator

Autorotation maneuvers inherently offer little margin for error in execution and induce high pilot workload, particularly as the aircraft nears the ground in an autorotative flare. Control augmentation systems may potentially reduce pilot workload while simultaneously improving the likelihood of a successful landing by offering the pilot appropriate cues. This paper presents an initial investigation of a real-time trajectory generation scheme for autorotative flare based on time-to-contact theory. The algorithm exhibits deterministic runtime performance and provides a speed trajectory that can be tracked by a pilot or inner-loop controller to bring the vehicle to a desired landing point at the time of touchdown. A low-order model of the helicopter dynamics in autorotation is used to evaluate dynamic feasibility of the generated trajectories. By generating and evaluating trajectories to an array of candidate landing points, the set of reachable landing points in front of the aircraft is determined. Simulation results are presented in which the trajectory generator is coupled with a previously derived autorotation controller. Example cases and trade studies are conducted in a six degree-of-freedom simulation environment to demonstrate overall performance as well as robustness of the algorithm to variations in target landing point, helicopter gross weight, and winds. The robustness of the reachability determination portion of the algorithm is likewise evaluated through trade studies examining off-nominal flare entry conditions and the effects of winds.

scholarly journals Internet of Things for Smart Environment and Integrated Ecosystem

2018 ◽  
Vol 7 (3.12) ◽  
pp. 1218
Author(s):  
Renu Thapliyal ◽  
Ravi Kumar Patel ◽  
Ajit Kumar Yadav ◽  
Akhilesh Singh
Keyword(s):  
Internet Of Things ◽  
Real Time ◽  
Wireless Sensors ◽  
Home Automation ◽  
Time System ◽  
Real Time System ◽  
Introduction History ◽  
Virtual System ◽  
Increasing Demand ◽  
Real Time Application

Internet of things (IoT) is in increasing demand in our daily life. This is the technology that transforms the real-time system into the virtual system and makes the communication in between machines. The rapid growth of IoT can be easily noticed in industries like home automation, transport, robotics, environment, energy, water domain etc. The IoT is a technological revolution that represents the future of computing and communications, and its development depends on dynamic technical innovation in a number of important fields, from wireless sensors to nanotechnology. They are going to tag each object for identifying, automating, monitoring and controlling. The aim of this paper is to give an overview of introduction, history, architecture, real-time application, challenges and future aspects of IoT along with statistics and its application in monitoring for future.  

Temporally Consistent Simulation of Robots and Their Controllers

2014 ◽  
Author(s):  
James R. Taylor ◽  
Evan M. Drumwright ◽  
Gabriel Parmer
Keyword(s):  
Real Time ◽  
Collision Detection ◽  
Robot Control ◽  
Status Quo ◽  
Robot Dynamics ◽  
Control Software ◽  
Physical Systems ◽  
Detection Algorithms ◽  
Simulation Based ◽  
The Status

Researchers simulate robot dynamics to optimize gains, trajectories, and controls and to validate proper robot operation. In this paper, we focus on this latter application, which allows roboticists to verify that robots do not damage themselves, the environments they are situated within, or humans. In current simulations, robot control code runs in lockstep with the dynamics integration. This design can result in code that appears viable in simulation but runs too slowly on physical systems. Addressing this problem requires overcoming significant challenges that arise due both to the speed of dynamic simulation running time (simulations may run 1/10 or 1/100 of real-time or slower) and to the variability of the running times (e.g., the speed of collision detection algorithms depends on pairwise object proximities). These difficulties imply that one must not only slow the control software but also scale controller running speeds dynamically. We describe the numerous architectural and OS-level technical challenges that we have overcome to yield temporally consistent simulation for modeling robots that use only real-time processes, and we show that our system is superior to the status quo using simulation-based experiments.

scholarly journals Dynamic Motion Planning for Autonomous Assistive Surgical Robots

Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 957 ◽  
Author(s):  
Alessio Sozzi ◽  
Marcello Bonfè ◽  
Saverio Farsoni ◽  
Giacomo De Rossi ◽  
Riccardo Muradore
Keyword(s):  
Dynamical System ◽  
Fixed Point ◽  
Motion Planning ◽  
Real Time ◽  
Surgical Robots ◽  
Dynamic Changes ◽  
Dynamic Motion ◽  
Dynamic Motion Planning ◽  
Trajectory Generator ◽  
Mechanical Constraint

The paper addresses the problem of the generation of collision-free trajectories for a robotic manipulator, operating in a scenario in which obstacles may be moving at non-negligible velocities. In particular, the paper aims to present a trajectory generation solution that is fully executable in real-time and that can reactively adapt to both dynamic changes of the environment and fast reconfiguration of the robotic task. The proposed motion planner extends the method based on a dynamical system to cope with the peculiar kinematics of surgical robots for laparoscopic operations, the mechanical constraint being enforced by the fixed point of insertion into the abdomen of the patient the most challenging aspect. The paper includes a validation of the trajectory generator in both simulated and experimental scenarios.

scholarly journals An Augmented Discrete-Time Approach for Human-Robot Collaboration

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Peidong Liang ◽  
Lianzheng Ge ◽  
Yihuan Liu ◽  
Lijun Zhao ◽  
Ruifeng Li ◽  
...  
Keyword(s):  
Discrete Time ◽  
Human Motion ◽  
Stiffness Index ◽  
Robot Dynamics ◽  
Robot Arm ◽  
Human Arm ◽  
Human Kinematics ◽  
Human Motor ◽  
New Generation ◽  
Human Robot Collaboration

Human-robot collaboration (HRC) is a key feature to distinguish the new generation of robots from conventional robots. Relevant HRC topics have been extensively investigated recently in academic institutes and companies to improve human and robot interactive performance. Generally, human motor control regulates human motion adaptively to the external environment with safety, compliance, stability, and efficiency. Inspired by this, we propose an augmented approach to make a robot understand human motion behaviors based on human kinematics and human postural impedance adaptation. Human kinematics is identified by geometry kinematics approach to map human arm configuration as well as stiffness index controlled by hand gesture to anthropomorphic arm. While human arm postural stiffness is estimated and calibrated within robot empirical stability region, human motion is captured by employing a geometry vector approach based on Kinect. A biomimetic controller in discrete-time is employed to make Baxter robot arm imitate human arm behaviors based on Baxter robot dynamics. An object moving task is implemented to validate the performance of proposed methods based on Baxter robot simulator. Results show that the proposed approach to HRC is intuitive, stable, efficient, and compliant, which may have various applications in human-robot collaboration scenarios.

Study on Real-Time Compensation RTCP Module of Five-Axis CNC System

2011 ◽  
Vol 317-319 ◽  
pp. 1662-1667 ◽  
Author(s):  
Ze Hua Hu ◽  
Wei Qiang Gao ◽  
Chao Ting Qing ◽  
Cheng Sheng Fang
Keyword(s):  
Real Time ◽  
Calculation Method ◽  
Implementation Process ◽  
Cnc System ◽  
Module Theory ◽  
Hardware Platform ◽  
Nc Code ◽  
Compensation Error ◽  
Algorithm Implementation ◽  
Five Axis

Taking A-C axis dual rotary working table of 5-axis CNC system as an example, the function of RTCP is introduced and the performing difference between standard NC code and RTCP code is analyzed in this paper. Then, the calculation method of RTCP compensation error has been illustrated. Taking the high precision as the objective, a new real time compensation RTCP module theory is presented and its algorithm implementation process is introduced. Then, this algorithm has been simulated using MATLAB and validated in hardware platform.

Three Dimensional Highway Real-Time Visual System Design and Application

2011 ◽  
Vol 467-469 ◽  
pp. 63-68
Author(s):  
Hai Feng Li ◽  
Xue Jun Xu ◽  
Xin Sha Fu
Keyword(s):  
Visual System ◽  
Real Time ◽  
Design Method ◽  
Three Dimensional ◽  
Safety Design ◽  
Physics Simulation ◽  
Fast Development ◽  
Increasing Demand ◽  
Highway Alignment ◽  
Highway System

With the fast development of the freeway construction in China and the increasing demand of the improvement of the landscape and safety in the highway system, the traditional method of the highway alignment design cannot meet the need mentioned above. A Three dimensional highway real-time visual system (3DHVS) is developed as a basic platform for the highway visual and physics simulate, which had many merit in the highway alignment, landscape and safety design by the means of fly-through, interactive and physics simulation with the virtual scene. By analyzing the disadvantage of the widely used design method, a performance and expansible architecture of 3DHVS is presented. Finally, we show the application of the system.

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