Trajectory_control

This video shows the execution of a new controller for the 4dof parallel robot. It is a hybrid controller that uses window-based least (WLS) squares or recursive least squares (RLS) for the identification of the robot’s parameters. In this case, by means RLS we estimate the first and second relevant parameters. The first relevant parameter corresponds basically to the mobile platform mass and the second relevant parameter represent the first inertia moment on X axis of the limb 1.

This video shows the execution of a trajectory (ACT3) by 4dof reconfigurable robot structed in optimal configuration 1. The ACT3 perform independent linear motions to reach XF=-0.144m, ZF=0.705m, roll angle: 7.78º and pitch angle: 16.8º.

In this trajectory although the final point is a non-singular configuration, the motion control is lost and the mobile platform can perform a non-singular assembly mode change by applying an external force.

This video shows the execution of a trajectory (ACT2) by 4dof reconfigurable robot structed in optimal configuration 1. The ACT2 develop independent linear motions to reach X_F=-0.1m, Z_F=0.75m, roll angle: -15º and pitch angle: 0º.

In this trajectory although the final point is a non-singular configuration, the motion control is lost and the mobile platform can perform a singular assembly mode change by applying an external force.

This video shows the reference generation, load and execution the trajectory by means of a 3dof parallel manipulator.

First, the generation of the robot reference is obtained using a virtual joystick programmed in LabView, the systems engineering software of National Instruments. With this application the user can indicate the height of the mobile platform, as well as its orientation (pitch and roll angles). The reference can be generated using a mobile telephone or a digital tablet.

This video shows the trajectory of the 4-degreeof-freedom robot developed in the field of the research project.

As can be seen, the robot performs movements in the X-Z plane varying the orientation of the platform (roll and pitch). This trajectory is repeated 5 times.

This video shows the execution of a trajectory (TT2) by the 4dof reconfigurable robot. The TT2 trajectory has a simultaneous motion of 0.2m on the X_F axis, 0.1m on Z_F, while  the pitch angle rotates 15º and yaw angle rotates 59º:

In this trajectory (TT2) the robot reaches a singular point. You can see that when it is on the singular point, the robot wins (at least) one DOF, so the robot gets to lose control and it is possible to move the robot with a finger.

This video shows the execution of a trajectory (TT4) by the 4dof reconfigurable robot. The TT4 trajectory is an elliptical motion on Z_F axis as a function of 0.2m displacement on the X_F axis, while the pitch angle rotates 5º and yaw angle rotates 10º.

With this trajectory the robot reaches a singular point, so you can see that when it is on the singular point, the robot wins (at least) one DOF, so the robot gets to lose control and it is possible to move the robot with a finger.

This video shows the execution of a trajectory (TT7) by the 4dof reconfigurable robot. The TT7 trajectory has a elliptical motion on the Z_F axis as a function of 0.1m displacement on the X_F axis.

In this trajectory the robot does not pass by any singular point therefore, the control is not lost at any time and the response of the robot follows in a very precise way the reference of motion.

This video shows the execution of a trajectory (TT6) by the 4dof reconfigurable robot. The TT6 trajectory is a displacement of 0.1m on the X_F axis while  the pitch angle rotates 20º and yaw angle rotates 10º.

In this trajectory the robot does not pass by any singular point, therefore, the control is not lost at any time and the response of the robot follows in a very precise way the motion reference.

This video shows the actual parallel robot executing a trajectory. The encoder sensors obtain the displacement of each robot joint to stablish the trajectory control and, in order to validate the results, the stereophotogrammetry system record the robot movements. The trajectory obtained by the cameras ratify the results obtained by the encoders.