Digital Theses Archive


Tesi etd-03172021-114240

Type of thesis
Novel collaborative technologies and control strategies for augmented human-robot collaboration in computer-integrated medical environments
Scientific disciplinary sector
Istituto di Biorobotica - BIOROBOTICS
relatore Prof. DARIO, PAOLO
  • Biomedical engineering
  • Capacitive sensor
  • Collaborative robotics
  • Industry 4.0
  • Sensors
Exam session start date
As soon as robots leave their cages, we envision robot assistants that physically support the human beings in both industrial and medical environments, enhancing the team efficiency and channelling high performances in terms of precision, repeatability and velocity. With the aim of fully exploiting the benefits of Human-Robot Collaboration (HRC) both physical and not, robot behaviour must be goal-oriented, efficient, intuitive and comfortable for a human co-worker, but, most of all, it has to be SAFE. <br>To achieve the above desired characteristics and being focused on the safety topic the thesis first studies such collaboration from a regulatory point of view. The gained insights are then used for evaluating the current solutions developed for either research (TRL 1-8) or market purposes (TRL 9). From the hardware perspective, we will browse several technologies emphasizing their advantages and their drawbacks. From a software perspective, instead, we will introduce few control strategies relying on both distance and contact information.<br>Such analysis, together with the regulations have paved the way to the design of a novel technology, developed and patented (WO2020012440A1) within this work with the aim of providing a perception system capable of enabling an enhanced collaboration.<br>It consists in a capacitive-based sensor technology for high-range proximity detection, composed of multiple active units. The single sensor unit embodies a multi-layer compliant structure with a coplanar plate capacitor configuration. A prototype, composed of two single active units, was designed using, for each one, conductive electrodes printed on a polyimide layer and positioned in the middle of soft polymeric insulating substrates, either acting as shock-absorber and for sensor electrical and mechanical protection. For an in-depth theoretical analysis of the physical capacitive principle, a conditioning electronic circuit (i.e. data collection, conversion, amplification and filtering modules) was built in order to collect a digital voltage output proportional to the variable sensed capacitance. Experiments were performed to characterize the single capacitive sensor and the multi-unit sensor technology (i.e. curve of response, dynamic response, accuracy and precision). The results confirmed the outcomes originally achieved through FEM simulations and the effectiveness of the technology in high-range detection. Using a combination of two active sensor units, an operating range was achieved of up to 15 times the performance of a single commercial capacitive sensor with comparable dimensions.<br>The developed technologies paved the way to a series of application relying on both proximity and contact detection where different fields have been investigated. Regarding proximity detection, the technology has been employed to: i) cover non regular surfaces to enhance collaborative robot performances or retro-fitting industrial robots; ii) enhance the interaction features of commercialized hands for optimizing the approaching phase that will affect the grasping performances; iii) develop a wearable sensorized belt for performing an on-line tracking of the capsule position during capsule endoscopy procedure; iv) monitoring the relative displacement of the bone during the fracture healing process.<br>Relying on the pressure detection, instead, the capacitive technology has been employed to: i) investigate and optimize object manipulation to potentially provide robust and immediate feedback about the object state during collaborative dynamic manipulation and ii) develop a capacitive-based device for high resolution manometry (Patent under evaluation: 102021000003197).<br>Finally, the patented capacitive technologiy (WO2020012440A1) has been licensed to Mediate srl with the aim of approaching the market making modular, easy-to-use and user-oriented contactless devices for remotely controlling the smart devices connected through the network.<br>