Sequential and Simultaneous Algorithms to Solve the Collision-Free Trajectory Planning Problem for Industrial Robots – Impact of Interpolation Functions and the Characteristics of the Actuators on Robot Performance

Trajectory planning for robots is a very important issue in those industrial activities which have been automated. The introduction of robots into industry seeks to upgrade not only the standards of quality but also productivity as the working time is increased and the useless or wasted time is reduced. Therefore, trajectory planning has an important role to play in achieving these objectives (the motion of robot arms will have an influence on the work done). Formally, the trajectory planning problem aims to find the force inputs (control 憲岫建岻) to move the actuators so that the robot follows a trajectory 圏岫建岻 that enables it to go from the initial configuration to the final one while avoiding obstacles. This is also known as the complete motion planning problem compared with the path planning problem in which the temporal evolution of motion is neglected. An important part of obtaining an efficient trajectory plan lies with both the interpolation function used to help obtain the trajectory and the robot actuators. Ultimately actuators will generate the robot motion, and it is very important for robot behavior to be smooth. Therefore, the trajectory planning algorithms should take into account the characteristics of the actuators without forgetting the interpolation functions which also have an impact on the resulting motion. As well as smooth robot motion, it is also necessary to monitor some working parameters to verify the efficiency of the process, because most of the time the user seeks to optimize certain objective functions. Among the most important working parameters and variables are the time required to get the trajectory done, the input torques, the energy consumed and the power transmitted. The kinematic properties of the robot ́s links, such as the velocities, accelerations and jerks are also important. The trajectory algorithm should also not overlook the presence of possible obstacles in the workspace. Therefore it is very important to model both the workspace and the obstacles efficiently. The quality of the collision avoidance procedure will depend on this modelization.