Meeting Abstract

P1.190  Friday, Jan. 4  Exploring asynchronous flight-muscle mechanics in insects through a bio-mimetic flapping machine CHOUDHURY, S*; MANIKKAM, DK; BERG, O; MULLER, UK; California State University Fresno; California State University Fresno; California State University Fresno; California State University Fresno umuller@csufresno.edu

To explore the asynchronous flight-muscle activation in insects, we developed a bio-mimetic flapping machine. In beetles, flies, true bugs, and bees, the frequency of wing strokes is higher than the frequency of nerve impulses. The contractions of asynchronous muscles are sustained by oscillations under mechanical control, rather than nervous control. Thus, delayed stretch-activation allows the flight muscle to oscillate spontaneously when coupled to a resonant load. Our machine mimics the force vs. extension properties of a muscle through the use of a solenoidal linear actuator. The output of a Hall-effect position sensor controls the current to the solenoid. Sustained oscillations are observed when the feedback is delayed with respect to the instantaneous actuator position. We have tested the effects of damping, feedback delay, and restoring force on the flapping amplitude and frequency. The resonant frequency and optimal delays are not affected as damping is increased; however, oscillation cannot be achieved without raising the feedback gain. We have solved the corresponding delay differential equation for a damped, driven harmonic oscillator; this numerical map of oscillator amplitude as a function of damping and delay is in quantitative agreement with the behavior of the machine. For electro-mechanical robots, this machine is a flexible test bed for the exploration of distributed (vs. central) control of flapping motion; however, the model is not suitable for flight. Similar to insects, the absence of a separate ‘function generator’ – to define the flapping kinematics – is advantageous when autonomy, simplicity, and speed of the control system are crucial.