There are numerous sensors for understanding the position, movement and various other parameters of a robotic system. But robots such as grippers still lack the ability to comprehend the material they are touching/holding and its relationship with it. Force transducers can tell the gripper when there is something pushing against it but not more.
How does a system comprehend how strong is the material pushing against the surface? Is the material slipping and what is the direction it is moving in? How can the system incorporate this data into some form of a closed loop mechanism to hold the material with the ideal amount of force ? The objective of this project is to answer these questions by developing an open source sensor which will consist of an array of MEMS pressure sensors with built-in intelligence.
The idea is based on the concept of designing discrete pressure sensing points as a known mathematical array and connected in a circuit board with simple communication interface. The array will be embedded in soft silicone rubber which comes in contact with the material (being held by the gripper). The output from the sensor can then be fed to the main MCU as a closed loop mechanism to improve the positional activity of the gripper.
My initial ideas were to develop only a tactile sensor based on a tiny pressure sensor but over the past few days, through my studies and research, I have found some work already done in academia. Refer here for extensive documentation. I will be extending the use of tactile sensors on a robotic gripper design to pick-up components and perform a fusion sensing with other sensors such as encoder, accelerometers in closed feedback loop with a servo motor.
The end objective is develop an open source robotic gripper which can do the following :-
1. Modular system so that it can be attached to any robotic system - be it a pick-place machine or humanoid machines.
2. It should consist of actuators to make it lightweight and easy to assemble and hence convenient in case of modifications are required.
3. Sensors should be embedded within such a system to capture the movements and positions of the jaws of the gripper accurately.
4. One of the sensors installed on every jaw will be a tactile array sensor so that pressure and force sensing can be easily checked.