The pectoral fin is a major source of thrust generation for fish utilizing median or paired fins (MPF) mode. Along with the pectoral fin, spanwise flexibility plays a major role in the generation of thrust. This paper investigates the effect of spanwise flexibility on propulsion performance using theoretical and experimental studies. For this study, the kinematic model of oscillating pectoral fin is first established based on the mechanism of active/passive flexible deformation. The dynamic model of the oscillating pectoral fin is developed based on the blade element theory. The influence of spanwise flexibility on propulsion performance is analyzed theoretically. Experiments have also been carried out to study the propulsion performance of the bionic pectoral fin by changing spanwise flexibility. Both calculated results and experiment results show that the propulsion performance of the bionic pectoral fin can be enhanced with the certain degree of spanwise flexibility.

To overcome the overshoot and oscillation in the normal Bang-Bang controller applied in the pneumatic driving glass-wall cleaning robot, this paper presents a F&A compensating variable Bang-Bang control algorithm for the pneumatic position servo. Besides a new cylinder driving plan is designed, the control algorithm is also improved by adding a fiction force compensating item in the chamber force evaluation equation. To adjust the controlling parameters dynamically, certain increasing functions, such as step function, linear function and arc-tangent function, are used to define the piston's expectative acceleration along with the reduction of the piston's position error. To testify the feasibility of the control algorithms with the above three expectative acceleration setting functions respectively, a pneumatic glass-wall cleaning robot "Sky Cleaner 4" is used as a testing platform to implement a series of on-load position servo experiments. And the different results of them are compared.

This paper presents a novel field robot JL-I based on a reconfigurable concept for urban search and rescue applications. The robot consists of three identical modules; each module is an entire robotic system that can perform distributed activities. It features three-degrees-of-freedom (DOF) active joints actuated by serial and parallel mechanisms for changing shape and flexible docking mechanism. The docking mechanism enables adjacent modules to connect or disconnect flexibly and automatically. DOF analysis, working space analysis and the kinematics of the 3D active joint between connected modules are studied thoroughly. In the end a series of successful tests confirm the principles and the robot's capabilities.

This paper presents a novel calibration strategy for a 3DOF flexure-based parallel manipulator to overcome weaknesses and embrace merits of existing approaches. An algorithm so called simplex method is developed for the purpose of calibrating this manipulator by means of a camera-based data acquisition system. Calibration is performed according to the inverse kinematic model method. The Simplex method algorithm doesn't identify directly the errors of geometry parameters, but finds the most appropriate control model taking all the errors into account, thus can improve the moving accuracy of the end-effector sharply. In the calibration process, matrix regrouping method is introduced to obtain the most appropriate control model. After getting the control model experimentally, verification experiments utilizing a laser interferometer have also been conducted to prove the effectiveness of this novel calibration method

A flexure-based compliant parallel manipulator (FCPM) is a kind of compliant mechanism characterized by a complicate topological structure and multiple degrees of freedom (DOFs). Compared with its rigid-counterpart, a FCPM becomes more complicate in its mobility analysis. In this paper, the screw theory is applied to the mobility analysis of our FCPM as an instance of general FCPM. Firstly, the compliance matrices of both compliant elements and the whole mechanism are calculated by using adjoint transformation of compliance matrix between different coordinate frames. Secondly, the mobility characteristics of the FCPM is investigated by proposing a concept of "primary mobility of a FCPM" and a method of quantifying the primary mobility of the FCPM providing that the compliance matrix of the manipulator should be calculated primarily. The theoretical result reveals that mobility characteristics of the FCPM with current design parameters can satisfy the designer's original desire

Reconfigurable robots consist of many modules which are able to change the way they are connected. As a result, the robots have the capability of adopting different configurations to match various tasks and suit complex environments. This paper presents a novel field robot named JL-I which consists of three uniform modules. With the docking mechanisms, the modules can connect or disconnect flexibly and automatically. Furthermore the active joints formed by serial and parallel mechanisms endow the robot with the ability of changing shape in three dimensions. Consequently useful locomotion capabilities, such as crossing high vertical obstacles, getting self-recovery when the robot is upside-down are achieved. After describing the structural principle of the robot, the related kinematics analysis follows. In the end, the successful on-site tests confirm the principles described above and the robot's ability.

The robotic system is developed to improve the effect of microsurgery for keratoplasty. The autonomous suturing should be qualified for the operational requirements of microsurgical keratoplasty. Poorly modeled mechanism of robotic micromanipulator and slight movements of surgical objective point are hindrance for precise position and orientation of end-needle. Visual servo control is available to overcome these obstacles. An appropriate scheme of robotic vision is proposed. On the basis of biological binocular vision, a feasible method of calibration and reconstruction for surgical microscope is adopted. The model parameters estimated by linear regression are evaluated for accuracy, stability and robustness. The visual servo control is applied for guiding robotic end-needle to reach the penetrating objective point. The visual servo control has look-and-move architecture based on image feature. The experimental results show that the robotic system for microsurgical keratoplasty can fulfil the surgical task of suturing penetration precisely

Taking Shanghai Science and Technology Museum as the operation target, the robot named skycleaner which is totally actuated by pneumatic cylinders and is sucked to the glass walls with vacuum suckers is presented. In order to solve the problems of lower stiffness and the nonlinear movement characteristic of the pneumatic system, a method of segment and variable bang-bang controller is proposed to implement the accurate control of the position servo system using the principle of pneumatic pulse width-modulation (PWM). Testing results show that the controller can effectively improve the control quality. This implies that the method can meet the requirements of realization.

Visual servo control is needed for realizing automatic bio-micromanipulation and increasing the accuracy of micromanipulator. A dual-hand micromanipulation system with micro-visual-servo was developed for automating cell manipulation in biotechnology. This paper presents a complete solution for micro-visual-servo of the system, involving micro-visual-servo architecture, control law, modeling of image Jacobian and recognition algorithms of micro objects. The experimental results of micro-circle trajectory tracking and automatic transgenic operation verify the effectiveness of the micro-visual-servo solution.

An automatic micro manipulation system, which aims at various kinds of operations in the field of bio-engineering has been developed. Visual servo control is usually employed to improve the performance of the system. However, the great amount of computation that is required in image processing hinders the formation of a closed-loop control system with visual servo. In this paper, efforts are made to improve the performance of the vision system in two aspects: algorithm design and hardware implementation. Methods of correlation based pattern matching and morphological operation based image processing technique are used to implement the fast visual information abstraction, thus forming a real-time visual servo control system. The system performance and the result of an experiment on gene injection are given.