Calculation of the force and kinematic parameters of the transfer mechanism based on a twisted arm chain

Introduction. The paper presents a brief kinematic analysis, as well as the application of D'Alembert's principle to finding the relationship between the force parameters in the transmission mechanism of a robotic manipulator constructed from a twisted arm chain. The use of this transfer mechanism can enhance the life of the arm actuator, the accuracy of its positioning, and increase the workload compared to the flexible linkage actuators (twisted strings). The work aimed at obtaining dependences between the displacements of circuit elements, as well as their force parameters required to monitor the control system operation of these devices.Materials and Methods. In the course of solving the problem, an elementary segment (element) of the transmission chain was considered. To find the relationship between the loads in the element, the virtual displacement principle was used. When finding kinematic connections between displacements, a brief geometric analysis of the transmission chain element was carried out. To conduct a comparative analysis of the analytical dependences obtained, a simulation technique implemented on a graphical link model using the NX software package was applied.Results. In the course of the study, we obtained dependences for determining the magnitude of the moment developed on the input link, depending on the external workload and its rotation angle, as well as for defining the linear displacement of the output link. A simulation model of the actuator was constructed, which can be applied in the dynamic study of the actuator mechanism, taking into account the inertia of the links.Discussion and Conclusions. From the obtained analytical dependences, we determined the value of the angle of rotation of the input link of the mechanism element, at which the maximum torque value for a fixed workload on the output element was achieved, as well as the maximum linear displacement of the output link. The calculated values were in good agreement with similar values obtained from the results of the simulation experiment, which gave us the possibility of using analytical dependences in the formation of a robot control system. In addition, these dependences made it possible to provide the selection of actuators with the required force indicators.