Three-Component Force Measurement Sensor Based on an Elastic Silicone Element and a Magnetometer

The presence of force-moment sensing of robotic systems makes it possible to improve the quality of the interaction between the robot and the objects of the external environment. There are many ways to provide force-moment sensing, one of which is to use multicomponent force sensors. However, their cost is quite high, so it is important to search and develop more profitable technical solutions. In this regard, a three-component force measurement sensor was developed, built on the basis of an elastic silicone element, with a built-in permanent magnet, and a hall-effect magnetometer. This technical solution is low-cost. The paper describes the technological process for the production of a three-component force measurement sensor, based on 3D printing of the body with an FDM printer, which makes it cheap to manufacture, and molding of two-component silicone. The paper considers the process of soldering SMD components to boards using a soldering hair dryer, stencils and solder paste, and shows a stand for calibrating the manufactured sensors, consisting of micrometric screws and parts printed on an FDM 3D printer. The mathematical method for calibration is based on the least squares method. The result of calibration of a three-component force measurement sensor is given. The research results in the development of a working sensor with the following characteristics: resolution — 1 mN, sensor sensitivity — 0.005 T / N.

THE EXPERIMENTAL AND NUMERICAL STUDY OF THE FORCES DURING THE INCREMENTAL FORMING OF TITANIUM SHEETS

Incremental forming is a rapid prototyping process that allows sheets to be formed without using forming tools, using a numerically controlled machine tool. A wide variety of shapes can be generated with this process. The objective of this work is to study through experimental tests and numerical simulations the behavior of ASTM grade 2 titanium during incremental point forming (SPIF). A Spinner MFG850 machining center from ISET in JENDOUBA coupled to a multi-component force sensor FN7325 was used for the forming of thin sheets by this process. As the diameter of the punch and its incremental movement are parameters having a direct effect on the forming force, tests with diameters of the punches dp varying between 10 and 15 mm and various paths made up of circular movements in the horizontal plane have been carried out experimentally. Numerical simulation is carried out in large elastoplastic deformations with ABAQUS/explicit. Comparisons of the evolution of the forming force for different values of the diameter of the punch dp and of the displacement step ∆zare carried out.