Jianjun Yuan

The optimization scheme for EOD robot based on supervising control architecture

The explosive ordnance disposal task in constrained environments needs high efficiency of operation and adaptability to avoid obstacles. In this paper, a redundant manipulator is presented to enhance the manipulability, the mechanical and control system is introduced and supervised control framework is adopted to deal with approaching and grasping task in confined workspace. The manual configuration control is presented and the concept of Collision Threat Index (CTI) base on infra-red sensor information is defined for optimization. The optimization scheme of configuration adjustment for collision avoidance is adopted and the algorithm is intuitive and is suitable for real time control. A series of experiments of EOD task in under-vehicle environment have been done and the results show the effectiveness of presented approach.

Stability analyses of wheelchair robot based on “Human-in-the-Loop” control theory

The eight leg-wheels hybrid stair climbing wheelchair robot, was developed for aged and disabled person helping them moving freely in structured three-dimensional environment. The efforts of motion automation have been partly implemented, such as climbing up/down the stairs, traversing slope and obstacles, nevertheless without carrying the person. The person is the passenger, also the control object, as the same time the pilot of the wheelchair. Since the person in wheelchair changes his/her posture uncertainly, it is difficult to obtain a better solution of control only by thinking the model of wheelchair. This paper uses the wheelchair as the platform, and describes the entire closed-loop modeling and stability analysis together with its passenger, based on the control theory of “Human-in-the-Loop”.

Research on Novel Wire Driving Robot Manipulator for Local Industrial Production Line

The research on robot manipulator is not new topic. However, it is still not easy to localize the manipulator in present writers region nowadays. The reason partly comes from the difficulty of reducing the manufacturing cost as well as keeping high displacement accuracy. This paper describes the research on a novel wire driving robot manipulator as a try to substitute low cost, high accuracy and large payload ability localized manipulator for the common production. Generally speaking, as to the design method of robot arms, especially of large used industrial robot manipulators, installing the driving components -such as the electric motors, transmissions and so on -directly just nearby the relative joints, is still normal. The trial model described in this paper is a 4-degree-of-freedom robot manipulator for industrial purpose, which is designed with wire driving mechanism including novel wire tensioner so that the structure becomes compact and simple, the whole weight is dropped, at the same time, the output power to do work and the displacement accuracy are increased relatively. We describe the control system and carry out several experiments to verify performance of this first trial model and expect that could be put into large practical use in future.

The Auto-docking System Design for the Fuel Loading Robot Used in Hazardous Environment

The auto-docking system design for the fuel loading robot used in hazardous environment is presented. The mechanical structure and the sensing algorithm of this system are introduced in details. The sensor system adopts two accurate CCDs as the automatic visual positioning device to measure the position and the posture between the manipulator of the robot and the objective in case of the good visual condition, besides, as a compensation for the shortage of the vision system, the tactile sensor system which likes the probe of an insect is also employed. The precision of proposed vision and tactile sensory system is analyzed. The result of experiment and the simulation indicate that this auto-docking system features rapid reaction speed and high measurement precision, which can be used to implement the auto-docking task for the fuel loading robot in hazard environment.

Virtual realization of automatic stair-climbing motion by leg-wheeled hybrid mobile robot

We have already researched and realized some of the automatic control motions for eight leg-wheels hybrid stair climbing mobile robot, which was developed for aged and disabled person helping them moving freely in structured environment. However, the implementation of such control algorithm has to be carefully checked before carrying person on. In this paper, we discuss the efficiency of the control algorithm for stair climbing, slope, complex steps and simple obstacles; also, examine the reliability and safety based on the virtual platform built in OpenGL.

Design of cooling system for inspection manipulator and analysis based on experiment

Purpose – This paper aims to present a different cooling method (water cooling) to protect all the mechanical/electrical components for Tokamak in-vessel inspection manipulator. The method is demonstrated effective through high temperature experiment, which provides an economical and robust approach for manipulators to work normally under high temperature. Design/methodology/approach – The design of cooling system uses spiral copper tube structure, which is versatile for all types of key components of manipulator, including motors, encoders, drives and vision systems. Besides, temperature sensors are set at different positions of the manipulator to display temperature data to construct a close-loop feedback control system with cooling components. Findings – The cooling system for the whole inspection manipulator working under high temperature is effective. Using insulation material such as rubber foam as component coating can significantly reduce the environmental heat transferred to cooling system. Origi...

An automatic collision avoidance approach for remote control of redundant manipulator

In this paper, a modeling, planning and remote control of a redundant manipulator for a semi-structured ldquounder vehiclerdquo environment is investigated. The geometric characteristic is abstracted by the distance laser sensory information and collision danger is measured in real time to activate the self-motion of reshaping the configuration. To make a real time solution, a intuitive collision avoidance method is presented for planar manipulator. Incorporating the algorithm with the supervisory control framework, a dynamic trajectory planning algorithm is presented for rapidness requirement of bomb disposal tasks. The simulation and experiments prove the effectiveness of presented method.

Design and prototyping a cable-driven multi-stage telescopic arm for mobile surveillance robots

Telescopic mechanism has lots of merits and is used in devices and equipment long before the appearance of robots. This paper explores the merits of telescopic mechanism and designs a cable-driven multi-stage telescopic arm with only one actuated degree of freedom (DOF) for mobile surveillance robots. We use pulleys and cables as the transmission system and use a DC motor together with harmonic drive as the actuation system. We analyze the integration of pulleys and cables to reduce cost and carry out numerical analysis by simulation and prototyping. The results show that our arm is fast, portable, stable and has low cost. We expect it to be widely employed for camera lifting tasks in mobile surveillance systems without significantly increasing costs. We also expect its general usage as an arm to support various end-effectors.

An improved rate-monotonic scheduler and a real-time open control platform for robotic control algorithm verification

The verification of new intelligent robotic control algorithm not only requires the correction of computation but also satisfies the timing constraints. In this paper, an open real-time control environment is designed and implemented for robotic control algorithm verification. With Windows NTs real time extension RTX, the PC based control system will have good real-time performance for new control algorithm research. The software structure and the task scheduling approach are described in detail and the software comprises of real-time motion control & trajectory planning process, the uses operating interface process and the inter-process communication module. Considering the uncertainty in computation time of complex intelligent algorithms in robotic systems, the running time of the algorithm is monitored online and an improved rate-monotonic scheduler is presented for schedulability verification. To prove the effectiveness of the open real-time control environment and task scheduler, two examples, a direct driven air-bearing stage for IC packaging and a SCARA type robot for assembly, are introduced. The control performance and task scheduling results show that the open real time control environment and new scheduler are successful in complex control algorithm research and timing verification.

Structural analysis of steel-cable-driven multi-joint robot manipulator

We have been researching robot manipulators with steel-cable-driven structure. The reason of using such are to implement serial manipulators interesting performance such as low cost, large payload ability as well as light self-weight, and also flexible features. While, on the other hand, the normal ring winding structure remains disadvantage in motion coupling, also complex in control. In this paper, we first propose a novel planetary 8-shape cable winding structure in n-DOF robot manipulator, and then discuss its characteristics, such as the geometry, the kinematics, and the force/torque transmission mechanism. The later chapter of the paper reports a trial 5-DOF model with basic experiments to verify the above theoretical analysis and simulation. Hopefully, such structure should have the possibility to expanding its application into industry, serial manipulator, snake-like structure, for instance.