Wrench distribution of a cooperative robotic system using a modified scaling factor method

Abstract

Recently, industrial robots are being more and more widely used in a variety of machining applications, such as drilling, milling and grinding because of their flexibility in performing tasks in a relatively small space, and furthermore, at a lower cost. In many cases, the wrench capability of industrial robots is lower than the required, causing in some tasks the saturation of the actuators. The possibility of using two or more robots to perform a given task increases the wrench capability, allowing us to work out in applications which are impossible to solve using only one manipulator. A Cooperative Robotic System (CRS) increases the flexibility in the performance of tasks allowing a more homogeneous distribution of the forces generated during the interaction between the end-effector and the environment. In some cases, the CRS can be composed by robots with different capabilities, and a strategy for wrench distribution must be used. Recent works presented the force capability analysis using a scaling factor method for single serial robots. This paper proposes the use of this scaling factor method in CRS, seeking to obtain a balance of forces between the robots. The proposed method is discussed and graphical results are presented.

Collision Avoidance for Redundant 7-DOF Robots Using a Critically Damped Dynamic Approach

“…Additionally, in the presented simulation, the available degree of redundancy is 1, and it is strictly sufficient to solve the collision-avoidance problem without including the joint limits control, as was achieved in other papers [15,20,48,[51][52][53] where the introduced redundancy was exploited by optimization procedures to find the best α that avoids reaching joint-position limits. The possible involvement of joint-position limits' control, over collision avoidance, in programming trajectories and kinematic algorithms solely depends on the availability of redundancy degrees higher than one, which, if available, can be exploited by implementing one of the strategies proposed in the literature, even with the proposed algorithm.…”

“…Additionally, in the presented simulation, the available degree of redundancy is 1, and it is strictly sufficient to solve the collision-avoidance problem without including the joint limits control, as was achieved in other papers [15,20,48,[51][52][53] where the introduced redundancy was exploited by optimization procedures to find the best α that avoids The angle α f smooths the resultant distances between the robot and the collision point. Figure 14 shows the behavior of the distance between the SRS-type robot and the collision point (red) along the simulation, compared with the distances when under imminent collision (blue).…”

Stress Analysis of a Landing Gear Using the Davies Method

“…Taking these factors into account, the Davies method has proven to be a quite versatile tool, which allows countless analyses, among which are work capacity and strength in robots [3][4][5], stability analysis he heavy-duty vehicles [6][7][8], or mechanism optimization [9], among others.…”