The results of the experiments highlight the effective use of frameworks such as moveit to control low-dof robotic arms.

The results in the figure below illustrate the ability of the MoveIt framework to calculate trajectories for target objects at reasonable distances from the robot. This is directly caused by the low dof nature of the robot. Since the end effector can only move based on the length of the arm and the rotation.

The trajectories can be seen with an almost circular pattern. In theory, these areas should be circular. However, based on observations, the design of the robot plays a large role in the asymmetry of possible trajectories. Although the base link of the robot can be found at the very center of the table, the axis of rotation of the base rotator joint is not. As seen in the figure below, the wrist can be found more on the edge of the yellow area at 0 degrees compared to 180 degrees. This means that in these low-dof cases expectable behaviors can be seen with more symmetric models.

The results related to the pickup show the ability of the framework to approach the target object just by providing coordinates of where it is. As trajectories are calculated, regardless if the target object is successfully picked up or not, it is able to draw near the starting position, attempt a pickup, and move the end effector to the target placement. This is shown by the collected data which all successful pickups also have successful placements. This consistency shows the capability of this system to carry out tasks

Not only will it work for specified coordinates along a path (similar to an arc of a circle) but it can also work for acceptable ranges around it. Shown in the figure, the same experiment is done on areas with successful pickups but with 0.05 increments. The data shows that along the corners, additional pickups are possible even with variation in coordinates. The other figures show the differences of being in the optimal placement and being in the range around it.

Both of these examples are from successful outcomes the moment before the grasp pose happens. Figure on the top shows being in the optimal position, where the object is placed exactly in the front of the center of the palm. As seen in this figure, the position of the target object does not move nor tilt. On the other hand, Figure on the bottom comes from the coordinates in the said range. It shows a slight tilt right before the grasp and has tilted just enough that it does not fall down. Knowing that as long as a grasp happens, the place down successfully comes after, it shows that the design of the grasping mechanism is a major factor in deciding the range of the robot arm aside from its actual arm length.

However, as seen in the figure above*,* only a specific potion from the calculated trajectories successfully picks up the target object. It is in a circular curve from approximately 80 degrees to 270 degrees. There are several factors that went into this outcome.

First, the low dof nature of the robot made it difficult to change the orientation of the end effector. In this specific design of the model, the orientation of the end effector is only tangent to the defined circular plane by the data above. With this limitation, the movement of the arm to approach an object facing the end effector is in the counterclockwise direction. Thus, objects in the lower side of the circle, cannot be successfully picked up as the approach will take a clockwise direction, where the back of the hand will be facing the object and not the palm. This causes all the target objects to fall down and be unsuccessfully picked up.

Second, the use of MoveIt to calculate trajectories becomes inefficient without proper analysis of the scene. Since the pick and place script only considers the coordinates of the target object while not taking into account the shape and size, the trajectories computed are always direct, without the consideration of the object itself as a possible collision. These instances contribute to unsuccessful pickups, even in the range of possible pickup areas.