Adaptive sliding mode control of three-dimensional rotation of zebrafish larvae

Microinjection technique is an important method in the field of modern biotechnology in the past 50 years. However, there are few studies on organ injection in zebrafish, especially for automatic organ injection. More research focused on the injection of zebrafish embryos and eggs. The reasons are varied since zebrafish larva has complex soft body, which needs operator with rich experience to complete manual injection. However, the success rate could not be satisfied. Thus, a great desire exists to design a set of automatic microinjection system. In this paper, we design a visual servo microinjection system to orient the posture of zebrafish larvae. First, we use image recognition method to identify the position and posture of zebrafish larva in current image frame. Then, a 4-DOF manipulator with high accuracy is designed in order to realize the three-dimensional rotation control. According to the detected real-time posture of zebrafish larva, the adaptive sliding mode control algorithm is utilized to orient the zebrafish larva to designed posture. The experimental results show that the average success rate of orienting zebrafish larva could reach more than 90%, which is capable of meeting the general requirements of manual injection of zebrafish larvae.