Licheng Wu

A Numerical Simulation for Design and Operation of an Underactuated Finger Mechanism for LARM Hand

Abstract A simulation procedure for an underactuated finger mechanism is proposed for design purposes as based on the kinematics and statics analysis of mechanism operation. A reachable space is proposed and simulated to describe the range and capability to adaptively grasp objects with various shapes and sizes. A numerical example is reported as a result that has been simulated through a specific code with MATLAB program. Results are discussed for a proper design of a new finger mechanism for the LARM (Laboratory of Robotics and Mechatronics) Hand. Results show that the proposed design of a new underactuated finger mechanism can provide human-like grasping operation, and it can be embedded within the finger body with a human-sized mechanical design during the whole motion of grasp operation.

Water Dancer II-a: a Non-tethered Telecontrollable Water Strider Robot

Water Strider Robot (WSR) is a kind of bio-inspired micro robot that can stand and move on water surface via surface tension. In this paper, a design method is presented with algorithms for designing driving leg. Structure, control system and software of the robot are also discussed in details. A prototype Water Dancer II-a that is driven with two electric motors is presented as successfully tested in lab. The proposed WSR is tele-controlled with infrared signals and has the capability of turning and speed regulation with features of light tiny volume and low power consumption. Experimental results are reported and discussed to show practical feasibility of the presented WSR prototype. The new results in the paper are related also to the WSR prototype design with a robot body of less than 30 × 30 mm size and with ten leg rods of 90 mm length and 0.2 diameter that are able to provide lifting force for a water walk of the 6.0 grams robot at a forward speed of 20 cm/s or angular velocity of 9 degree/s with two micro DC motors(RoomFlight 4 × 8 mm, 28 Ohm).

Grasping Simulation of an Underactuated Finger Mechanism for Larm Hand

Abstract In this paper, the grasp operation of an underactuated finger mechanism is simulated with the aim to characterize and analyze its performance. The design of the proposed mechanism is based on spring systems that give suitable underactuation characteristics. A CAD model is proposed and then it is used in a procedure for numerical simulation. Simulation results show suitable capability for grasping a wide range of objects in size and shape by operating the mechanism inside the finger body. The achieved grasp has been simulated as a human-like functionality with a grasp contact in each phalanx.

A non-tethered telecontrollable Water Strider Robot prototype

The design method of Water Strider Robot (WSR) is discussed in the paper. A WSR prototype driven with two electric motors and tele-controlled via infrared signals is designed and successfully built. A set of algorithms for designing the size of the driving leg is also proposed. Moreover, the methods and an instance to design the structure, control system and software of the robot are present. With experiments, the proposed WSR is proofed the features of light, tiny volume and low power consumption. And the experiments show that it performs much better than other current WSR prototypes in most aspects.

Analysis and optimal design of a modular underactuated mechanism for robot fingers

A frame of modular design problems and requirements for underactuated mechanisms is discussed as related to robotic fingers. The proposed modular mechanism is connected sequentially by series units of underactuated mechanisms, which have the feature of passive self-adaptive in grasp operation and uniformizable in design procedure. The design considerations for modular underactuated mechanism are outlined. Optimality criteria are analyzed with the aim to formulate a general design algorithm. An example of a four-phalanx modular robotic finger is studied as an improvement of new version LARM Hand with the aim to show the practical feasibility for the proposed modular concepts and design methods.

Dynamic modeling and fuzzy control of water strider robot

To make water strider robot (WSR) walk on the water, the robots dynamics modeling and control algorithms are discussed in the paper. The dynamics equations of WSR and dynamics equations concerning the actuator (motor) are established. Considering the motions non-holonomic feature of the WSR, and inaccurate equations themselves, a fuzzy control method is applied in the paper. After calibration of the sensor, on the basis of fitting motor voltage and rotation speed, a fuzzy controller is developed to allow the robot approaching the light source target and tracking the trajectory of the target. Finally Matlab/Simulink is used to simulate autonomous motion of water strider robot. Simulation results show the effectiveness and accuracy of the approach.