Abstract
The determination of the optimal position of a robotic task within a manipulator’s workspace is crucial for the manipulator to achieve high performance regarding selected aspects of its operation. In this paper, a method for determining the optimal task placement for a serial manipulator is presented, so that the required joint torques are minimized. The task considered comprises the exercise of a given force in a given direction along a 3D path followed by the end effector. Given that many such tasks are usually conducted by human workers and as such the utilized trajectories are quite complex to model, a Human Robot Interaction (HRI) approach was chosen to define the task, where the robot is taught the task trajectory by a human operator. Furthermore, the presented method considers the singular free paths of the manipulator’s end-effector motion in the configuration space. Simulation results are utilized to set up a physical execution of the task in the optimal derived position within a UR-3 manipulator’s workspace. For reference the task is also placed at an arbitrary “bad” location in order to validate the simulation results. Experimental results verify that the positioning of the task at the optimal location derived by the presented method allows for the task execution with minimum joint torques as opposed to the arbitrary position.
Highlights
During the planning of a robotic task, the designer must address a number of key issues regarding the task execution by the manipulator, so as the resulting workcell will achieve the best possible performance
This increased effectiveness in transmission may be interpreted into a number of different gains for the end user, such as lower energy consumption, lower loading of joint’s motors, etc.; since the process places the task in a location where the a given end effector force is exerted utilizing minimum joint torques, an increase in the joint torques at the optimal task location will result in the end effector exerting larger forces
This is a significant gain for the designer, since using the presented method they may place a dynamic task in a location where the robot will exhibit increased dynamic performance via the minimization of utilized joint torques and increased energy consumption performance via the reduction in the utilized electrical current by the joint motors
Summary
One of the cornerstones in robotic task design is the determination of the workcell configuration and most importantly, the positioning of the task within the manipulator’s workspace so that during task execution the robot would be able to exert high performance characteristics as per the task requirements. Such characteristics may vary, depending on the type of task (kinematic or dynamic) as well as on the requirements regarding performance as set by the designer (i.e., minimization of cycle time, low energy consumption etc.). Due to the direct proportional relationship between the manipulator’s joint torques and the consumed energy during the exertion of these torques by the joints, minimizing the required torques required for the task would inevitably reduce the manipulator’s power consumption
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
