Adaptive Hybrid Control for Rotationally Oscillating Drill (Ros-Drill^©), Using a Low-Resolution Sensor

A novel hybrid (i.e., discrete/continuous) control system is studied on a cellular microinjector technology called the Ros-Drill^© (Rotationally Oscillating Drill). Ros-Drill^© is developed primarily for ICSI (Intra-Cytoplasmic Sperm Injection). It is an inexpensive set-up, which creates high-frequency rotational oscillations at the tip of an injection pipette tracking a harmonic motion profile. These rotational oscillations enable the pipette to drill into cell membranes with minimum biological damage. Such a motion control procedure presents no particular difficulty when it uses sufficiently precise motion sensors. However, size, costs and accessibility of technology on hardware components may severely constrain the sensory capabilities. Then the trajectory tracking is adversely affected. In this paper we handle such a practical case, and present a novel adaptive-hybrid control logic to overcome the hurdles. The control is implemented using a commonly available microcontroller and extremely low-resolution position measurements. First, the continuous control system is analyzed and designed. Then, an adaptive, robust and optimal PID (proportional-integral-derivative) control strategy is performed. We demonstrate via simulations and experiments that the tracking of the harmonic rotational motion is achieved with desirable fidelity.