Telerobotics is the area of robotics concerned with the control of semi-autonomous robots from a distance (source: Wikipedia). It is defined as the combination of teleoperation and telepresence. The first part, teleoperation, enables an operator to remote control a robot. The second part, telepresence, gives the operator the ability to “sense” the robot in its interaction with its environment. With the help of force-feedback, the operator is aware of the forces at play in the remote site, especially the inertia and friction of the robot, the weight of the tools, the robot joint limits, the collisions with obstacles, and the action of the robot on other objects. Force-feedback telerobotics is only possible with a force-feedback manipulator.
Why feeling the inertia of the robot is useful?
One common features about robots, whether industrial or collaborative, is that they come with a certain inertia. By controlling the robot through a force feedback manipulator, you will be able to feel that inertia, properly scaled down so as to be bearable. While rotating one joint, you may feel friction, resistance, due to the different mechanisms at play in the actuation. And when controlling the whole robot, you will feel the inertia combined of the whole system, including the tool and the payload.
Consequently, if you make a swift move with the force-feedback manipulator, you will feel a resistance coming from the robot, as it won’t be able to be as fast as you try to make it go. The same experience may happen when you try to stop your movement suddenly: the robot will try to carry on its trajectory for a little bit, taken away by its weight and the time necessary to slow down and stop its movement (its inertia) – a moment longer than the one needed for the user to stop the motion of the force-feedback manipulator alone (i.e. non coupled).
It is really critical for the operator to be aware of the dynamics of the robot, otherwise he/she will quickly lose control, by systematically overshooting the intended waypoints. Thanks to the force-feedback, the operator can make full use of his/her manual skills and apply his/her full dexterity to the task.
Feel the contacts with the environment!
Force feedback is all about giving the user a better awareness. When doing remote control, it is important to have as much feedback as possible: a vision system to give you the seeing, potentially a microphone to help you hear the noise of the distant environment, and importantly a force feedback manipulator to feel what and when you are touching.
The environment in which you work may be fragile: you would not want a 200kg payload robot to break something, because your joystick did not give you the information you were already touching the ceiling. In the same idea, your robot or end-effector may be very expensive or very fragile, and you probably do not want to break it because you accidentally hit the wall and, by lack of physical feedback, kept pushing in the same direction.
That is the goal of force feedback: providing the user with the force information so that, added with other senses, he/she is more aware of the distant environment and less liable to make a mistake.
Have a solid plan in case of unexpected situations!
You have been working on your automation program for weeks, if not for months. It is perfectly set to serve your process, to help your project in the environment as you have defined it. But unfortunately for you, something comes up: a last-minute change in the workplace and you have to rewrite part of the program, an element is not as it was described and cannot be taken as it was planned, or even worse: the program you have written has failed and simply does not work.
Whether we speak of nuclear decommissioning, with pre-programmed trajectories to perform cutting, deburring and other intensive tasks, or sensitive material pick and place in the chemical industry, you cannot afford to lose time and leave the task unfinished. By offering yourself a force feedback telerobotic system, you get a solution that will not be let down by a line of code. You can finish the task you are doing so you do not slow down the project or have to turn off the line, giving yourself enough time to fix the main problem- or use the telerobotic system as the main solution.