High Payload Robots Research Articles

Collision detection for collaborative assembly operations on high-payload robots

Human-robot collaboration for high-payload industrial applications has the potential to unlock new applications and improve operator ergonomics. However, ensuring safety with closer proximity remains challenging due to the large payload. Collision detection can improve safety, but must be modified to consider the dynamics of high payload applications (internal oscillation, effective low-pass filtering of external force), while the higher inertia raises questions about the resulting collision forces. This paper proposes the first collision detection approach for high-payload applications, using a force/torque sensor at the end-effector and motor current measurements for redundancy to be compliant with ISO/TS 15066:2016. Analysis of a linear model informs the design of the detection algorithm and effect of higher payload. Experimental validation shows feasibility and performance of collision detection over a range of motion and payload conditions, and the impact of the safety system in improving an industrial use-case.

Towards seamless collaboration of humans and high-payload robots: An automotive case study

Towards seamless collaboration of humans and high-payload robots: An automotive case study

Online compliance error compensation system for industrial manipulators in contact applications

Industrial manipulators are rarely used in high-force processes even though they provide flexibility, adaptability, relatively low cost, and a large workspace. This limited utilization is mainly due to their inherent low stiffness, which results in significant deformation. Hence, it is necessary to improve their accuracy in order to achieve high-precision requirements while performing tasks under load. This paper focuses on the development and implementation of an online compliance error compensation system for industrial manipulators. The proposed algorithm computes the compensation based on an elasto-geometric robot model and process forces measured with a force sensor mounted between the robot mechanical interface and the end effector. The performance of the compensation system is evaluated experimentally in two high payload robots from different manufacturers in which the compensation was carried out to reduce the mean deformation of circular trajectories under load. • Compensation is computed using an elasto-geometric model and measured process forces. • Deformation is compensated by online adaptation of the position reference signal. • Experiments considered several sections of the workspace, payloads, and TCP speeds. • Performance criteria evaluated the distance between loaded and unloaded trajectories.

Design of Human Robot Collaboration workstations – Two automotive case studies

Human Robot Collaboration assembly cells benefit the capabilities and skills of both industrial robots and humans, although fenceless coexistence leads to issues related to safety and human-system interaction. A series of methods for hybrid workstation design focusing on safe yet efficient Human Robot Collaboration is presented, where various layout configurations are illustrated and evaluated aiming industrial implementation. Two distinct automotive use cases, with different requirements and challenges, are used as reference for highlighting particularities on lightweight and high-payload robots, in addition to small and large size product assemblies.

Feasibility of machining using low payload robots

Robotics has been positioned as an alternative in a wide range of processes, due to it low cost and high flexibility. The use of robots in machining tasks has had a great development in high payload robots. This work shows the characterization and use possibilities of a low payload robot in machining tasks. Robot usability has been evaluated through a cutting force model and a study of cutting parameters. Finally, a new methodology is proposed that allows to estimate if a low payload robot is capable to perform a specific machining task considering robot force and torque limitations.

FSW Process Tolerance According to the Position and Orientation of the Tool: Requirement for the Means of Production Design

Friction Stir Welding (FSW) is an innovative welding process increasingly used by industry for the welding of aluminum alloys. In order to reduce the high investment costs of a dedicated FSW’s machine and in order to offer more flexibility to weld complex geometry, high payload robots may be used. A serial kinematics robot meets these specifications but under the stresses generated during welding, its structure readily deforms. The consequences are deviations of the tool nominal position with respect to the seam. The work presented here proposes to study the process tolerances with tool positioning defect. An experimental study enables to evaluate the influence of the tool position disorientation on weld quality, the travel force and torque generated. The objective is to estimate the impact of the disorientation on the tool mechanical interactions when welding using a serial kinematics robot.

Paris show features synchronous robots, laser welding robots and service robots

Reports from Industrie 2004 in Paris, the exhibition that took place alongside the International Symposium of Robotics (ISR), highlights the development of synchronous robot control, identifies innovation in the area of laser welding by robot, outlines the need for high payload robots.