A proximity/contact-force sensor for Human Safety in industrial robot environment (original) (raw)

Safe Close-Proximity and Physical Human-Robot Interaction Using Industrial Robots

2015 12th Conference on Computer and Robot Vision, 2015

Industrial robots have been employed worldwide in the manufacturing sector for performing tasks quickly, repeatedly and accurately in relatively static environments for over 30 years. In recent years, close physical interaction between industrial robots and human operators has attracted researchers' attention and encouraged a number of technological innovations to turn these robots into humanrobot platforms. In this work a specially designed compliant wrist is developed to support dexterous robotic interaction with live proximity and contact feedback. The compliant wrist incorporates a level of compliance into an initially noncompliant manipulator robot which allows the robot to dynamically adapt to the surfaces it approaches or touches. Furthermore, to facilitate human-robot interactions, the robot must be able to adapt its behavior to the human partner. Therefore, a real-time path planning method is developed to generate online motion, adapt the robot to dynamic changes in the environment and ensure smooth interactions. The performance of the proposed method is demonstrated through experimental results on a CRS-F3 manipulator.

Cooperative tasks between humans and robots in industrial environments

2012

Collaborative tasks between human operators and robotic manipulators can improve the performance and flexibility of industrial environments. Nevertheless, the safety of humans should always be guaranteed and the behaviour of the robots should be modified when a risk of collision may happen. This paper presents the research that the authors have performed in recent years in order to develop a human-robot interaction system which guarantees human safety by precisely tracking the complete body of the human and by activating safety strategies when the distance between them is too small. This paper not only summarizes the techniques which have been implemented in order to develop this system, but it also shows its application in three real human-robot interaction tasks.

A Virtual Pressure and Force Sensor for Safety Evaluation in Collaboration Robot Application

Sensors, 2019

Recent developments in robotics have resulted in implementations that have drastically increased collaborative interactions between robots and humans. As robots have the potential to collide intentionally and/or unexpectedly with a human during the collaboration, effective measures to ensure human safety must be devised. In order to estimate the collision safety of a robot, this study proposes a virtual sensor based on an analytical contact model that accurately estimates the peak collision force and pressure as the robot moves along a pre-defined path, even before the occurrence of a collision event, with a short computation time. The estimated physical interaction values that would be caused by the (hypothetical) collision were compared to the collision safety thresholds provided within ISO/TS 15066 to evaluate the safety of the operation. In this virtual collision sensor model, the nonlinear physical characteristics and the effect of the contact surface shape were included to ass...

Cooperation of human operator and small industrial robot

Cooperation between a small industrial robot and human operator is studied in this paper. To ensure safe human-robot interaction several safety features should be introduced into the industrial cell. Despite all the precautions undertaken the collision between robot and man can occur. In present study impact assessments of point robot end-effector with passive mechanical arm were carried out. The impact energy density was calculated and used to evaluate possible injury levels caused by collisions and to determine a safe range of future investigations with human volunteers.

A Review of Safety Methods for Human-robot Collaboration and a Proposed Novel Approach

Proceedings of the 16th International Conference on Informatics in Control, Automation and Robotics, 2019

Industrial robots offer the advantage of flexible manufacturing and increased efficiency when paired with human workers. However, this means breaking well-established safety procedures such as safety fences and workspace separation. Robots present a danger to humans as they work at high speeds with sudden motions. It is therefore necessary to ensure safe interaction during collaboration. This paper presents a collection of sources that explain the trends and advances in the field of industrial robotics specifically to safety in humanrobot interaction. Major trends and popular methods lean towards obstacle avoidance using a sensory planning method of polynomials and a sensory system that is able to map the robot workspace. The goal of these methods is to ensure that the human is kept safe. These methods were used to develop a novel approach to safe interactions. This approach uses a LIDAR sensor for obstacle detection and tracking.

Collision detection and reaction: A contribution to safe physical Human-Robot Interaction

In the framework of physical human-robot interaction (pHRI), methodologies and experimental tests are presented for the problem of detecting and reacting to collisions between a robot manipulator and a human being. Using a lightweight robot that was especially designed for interactive and cooperative tasks, we show how reactive control strategies can significantly contribute to ensuring safety to the human during physical interaction. Several collision tests were carried out, illustrating the feasibility and effectiveness of the proposed approach. While a subjective ldquosafetyrdquo feeling is experienced by users when being able to naturally stop the robot in autonomous motion, a quantitative analysis of different reaction strategies was lacking. In order to compare these strategies on an objective basis, a mechanical verification platform has been built. The proposed collision detection and reactions methods prove to work very reliably and are effective in reducing contact forces far below any level which is dangerous to humans. Evaluations of impacts between robot and human arm or chest up to a maximum robot velocity of 2.7 m/s are presented.

Human-Robot Collision Avoidance Scheme for Industrial Settings Based on Injury Classification

HRI ’21 Companion, 2021

The objective of this paper is to develop a real-time, depth-sensing surveillance method to be used in factories that require human operators to complete tasks alongside collaborative robots. Traditionally, collision detection and analysis have been achieved with extra sensors that are attached to the robot to detect torque or current. In this study, a novel method using 3D object detection and raw 3D point cloud data is proposed to ensure safety by deriving the change in distance between humans and robots from depth maps. By not having to deal with any potential delay associated with extra sensor-based data, both the likelihood and severity of collaborative robot-induced injuries are expected to decrease.

SIMULATION OF COLLISION HANDLING IN INDUSTRIAL ROBOTS

This research work seeks to address collision handling, mainly the safety of humans in a robot work-cell and the avoidance of collision between the robots and any obstacle as this may lead to severe injuries if a robot collides with a human. Also collision detection and avoidance for industrial robots in harsh environments (e.g. explosive environments found in oil and gas sector) to avoid a potential accident that can also damage robots and other equipment in the environment. This research builds on the concept builds on collision detection and aims at enabling the robot to find a collision free path bypassing the obstacle and leading to the target position using different sensors. A simulator would be used here called Robotstudio simulator which is a 3D teaching demo, illustrating collision detection in a work cell. The Mobotsim which is an open source software is used to detect obstacles within a work cell and the Robotstudio simulator would demonstrate how this obstacle is detected and avoided by industrial robots.

Integration of perception, control and injury knowledge for safe human-robot interaction

IEEE International Conference on Robotics and Automation (ICRA), 2014

In the past few years the need for more flexibility in industrial production has implied a growing attention towards scenarios where humans work directly in touch with robots. In order to allow safe human-robot interaction, a methodology to evaluate the severity of an impact between a human worker and an industrial robot, based on related work on injury knowledge in human-robot contacts and relying on information coming from different exteroceptive sensors, has been developed in this paper. On the basis of this severity evaluation, the robot controller enforces a suitable safety-oriented strategy, ranging from on-path speed reduction to task-consistent evasive motion and protective stop. The safety evaluation methodology has been implemented in a dedicated software component, integrated with a video surveillance system and with the real time robot controller to obtain a complete HW/SW architecture named “Safety Controller”. The system has been validated on an ABB IRB140 robot.

Contact Estimation in Robot Interaction

International Journal of Advanced Robotic Systems, 2014

In the paper, safety issues are examined in a scenario in which a robot manipulator and a human perform the same task in the same workspace. During the task execution, the human should be able to physically interact with the robot, and in this case an estimation algorithm for both interaction forces and a contact point is proposed in order to guarantee safety conditions. The method, starting from residual joint torque estimation, allows both direct and adaptive computation of the contact point and force, based on a principle of equivalence of the contact forces. At the same time, all the unintended contacts must be avoided, and a suitable post-collision strategy is considered to move the robot away from the collision area or else to reduce impact effects. Proper experimental tests have demonstrated the applicability in practice of both the post-impact strategy and the estimation algorithms; furthermore, experiments demonstrate the different behaviour resulting from the adaptation of the contact point as opposed to direct calculation.