The DEFROST team works on deformable robots. A deformable robot is composed of deformable structures on which forces are applied to produce motion. Their design is often inspired by the mechanical properties of living organisms [Kim et al 2013]. These deformable robots have the advantage of being inexpensive to manufacture, robust and less dangerous in the context of interaction with humans. This new branch of robotics opens many prospects of applications. Soft manipulators can especially be interesting in an industrial context, where safe operation nearby human coworkers and low cost are desirable.
Using a soft manipulator in industrial pick and place applications require them to be accurate and fast, which are both big challenges in soft robotics today. At medium to large scale, these robots are especially subject to vibrations due to their compliance that need to be compensated. The current research on their dynamic control is limited by the absence of a suitable experimental platform, i.e. a prototype physically capable of being accurate, moving fast, and with a control law running at high frequency (~1kHz). The goal of the two internships below is to design and implement such a prototype in the context of pick and place operations. It will focus in particular on a parallel architecture, where several elastic legs are fixed to a common end-effector platform to provide better payload and accuracy.
The main goal of this internship is to design and build the mechanical and electrical structure of the soft manipulator. The study can follow the 4 steps below:
The first step will consist in designing the mechanical structure of the robot to satisfy pre-defined specifications in terms for example of workspace (reach), payload, and speed. The prototype will have to follow a pre-defined topology of parallel architecture in terms of number, arrangement of elastic legs, and actuation strategy (MAXON brushless motors). Other topologies can be proposed during the internship, following the student’s progress and interest. The material and geometry of the legs will have to be determined to meet the design requirements. The SOFA software [Faure et al 2012], developed by the Defrost Team, will be provided to simulate the robot and evaluate the performance of a given choice of legs.
The second step will focus on creating the computer-assisted design of the whole prototype, including the flexible manipulator itself as well as the supporting frame, the eventual set of sensors for feedback (bending sensors, cameras), and the electrical cabinet. This last one will have to contain the motor drivers (EPOS, MAXON) and be completed (with power supply, connectors, sensor amplifiers, …) to allow for the standalone use of the prototype.
The third step will consist in fabricating the mechanical structure of the prototype as well as its electrical cabinet. Additive manufacturing, conventional machining, and laser cutting technologies will be made available for producing mechanical parts (Centrale Lille). The electrical circuit will be fabricated in-house (INRIA).
The fourth step will be on testing and characterizing the fabricated prototype, and in particular in validating that the desired specifications have indeed been obtained.
Quentin Peyron: [email protected]
Christian Duriez : [email protected]