In coping with the trend toward the much higher powered electric-motor driven injection molding machine, multi-AC servomotors control system has become necessary in order to control the molding machine mechanism. Thus, it is inevitable to use a synchronous positioning control technique not to cause the excessive mechanical stress in the machine body. It is possible to realize the synchronous po...

We show that a spiral wave core can be guided by feedback control through a two-dimensional (2D) medium along a virtual 1D detector of given shape. To this aim, short perturbations of excitability are applied globally to the medium each time the spiral wave front is tangent to the detector, or touches its open ends. This relatively simple and robust feedback algorithm is realized in experiments...

Insects produce a variety of exquisitely controlled manoeuvres during natural flight behaviour. Here we show how hawkmoths produce and control one such manoeuvre, an avoidance response consisting of rapid pitching up, rearward flight, pitching down (often past the original pitch angle), and then pitching up slowly to equilibrium. We triggered these manoeuvres via a sudden visual stimulus in fro...

In position control of mechatronic devices, velocity feedback is important for injecting additional damping to avoid low-frequency fluctuation around desired trajectories. In practice, velocity signal is often obtained by finite difference of position signal from an optical encoder. However, such a numerical differentiation produces high-frequency noise by magnifying quantization error containe...

When moving an object, the motor system estimates the dynamic properties of the object and then controls the movement using a combination of predictive feedforward control and proprioceptive feedback. In this study, we examined how the feedforward and proprioceptive feedback processes depend on the expected movement task. Subjects made fast elbow flexion movements from an initial position to a ...

Much progress has been made in brain-machine interface (BMI) development using closed-loop decoder adaptation (CLDA) methods. CLDA fits the decoder parameters during closed-loop BMI operation based on the neural activity and inferred user velocity intention. This progress has resulted in the recent high-performance ReFIT Kalman filter (ReFIT KF) [1]. Here we develop an adaptive optimal feedback...

In this paper we use Hamilton-Jacobi-Bellrnan theory to derive optimal nonlinear feedback control laws for a special class of nonlinear systems. The results are applied to a spacecraft angular velocity stabilization problem with two torque inputs. A family of optimal nonlinear feedback controllers that globally asymptotically stabilize angular velocity is established. Special cases of this fami...

In this paper we review some theoretical aspects of positive feedback in the control of movement. The focus is mainly on new theories regarding the reflexive role of sensory signals from mammalian tendon organ afferents. In static postures these afferents generally mediate negative force feedback. But in locomotion there is evidence of a switch to positive force feedback action. Positive feedba...