Biologically inspired actuation via electromagnetic motors

Electromagnetic motors convert stored energy to mechanical work linearly as described by the force-velocity relationship.  In biology, however, muscle actuation supplies power through hyperbolic F-V mechanisms – in which a parameter α characterizes the degree of nonlinearity.  Resulting from evolution, nonlinear F-V relationships appear and an optimized α value emerges for specialized muscle tasks.  We explore the benefits of implementing biologically inspired actuation in electromagnetic motors by means of a proportional-integral-differential (PID) controller.  A PID controller converts the characteristically linear force application of an electric motor to mimic nonlinear mechanical outputs of biological systems.  A converted nonlinear electric motor lifts weights of 50-200g, and we record the velocity of the weight and the applied force of the motor.  As a proof of concept, we optimize the gain coefficients of the controlling algorithm for a range of input α parameters and, relative to the Hill-type muscle, the nonlinear motor achieves goodness of fit measures of R² > 0.99.  Studies have shown that designing biologically inspired actuators produce comparatively energy efficient systems.  We explore the advantages of characterizing a simple linear electric motor with biologically inspired actuation as described by the Hill muscle’s nonlinear F-V relationship.  We investigate if there exists an optimized nonlinearity parameter α that provides maximum economic energy consumption.  An optimized bio-inspired nonlinear electromagnetic motor manifests robust and energy-efficient mechanical processes.