Development and characterization of a tactile array sensor for parallel grippers for use in object manipulation

Abstract

Within the era of modern robotics, during research as well as in industry, it is often the case to build robots that can mimic human-object interaction closely. To accom- plish this goal, excellence is required in many technological aspects, where one is tactile sensing. Tactile sensing is the ability of a system to measure information arising from physical interaction with its immediate environment. These include static & dynamic force/torque sensing, vibrations sensing and thermal sensing. To ful ll these require- ments, numerous types of sensors have been developed, which include but not limited to piezoresistive sensors, piezoelectric sensors, capacitive sensors and hall e ect based sensors. With any of the above sensors, it is necessary to accomplish mainly three tasks; at least one, if not all. These include contact point localization, dynamic sensing and tactile force measurement. These functionalities play a crucial role when developing human like grasping and manipulation capabilities. However, many problems arise during the design and manufacturing of these sensors due to the complexity of design, cost and di culties in practical implementation due to size. In order to overcome these di culties and ful ll the above mentioned requirements, this thesis presents a tactile gripper that has been developed based on hall e ect. An array of magnets and hall sensors create a unique combination of outputs for each di erent deformation of the dual layered silicon elastomer which houses the magnets. While allowing the interaction with non-planar surfaces due to the compliant nature of the silicon material, the sensor also facilitates accurate force recognition and contact localization using sensor readings and geometric properties of the silicon layer. This tactile gripper can be used for object manipulation and many other forms of tactile sensing requirements with necessary modi cations. Several experiments have been carried out to test and validate the operation of the sensor with successful results. This thesis aims to provide the entire design and development of the sensor & gripper, experimentation process, results, limitations and possible future improvements to the reader with the expectation that this development will aid current research in research community and industry. The end goal is to contribute to the process of developing tactile sensors which aids the progression of robotics technology that plays a crucial role in modern scienti c advancement.