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Controller discretization has the potential to jeopardize the stability of a bilateral teleoperation system. As reported in the literature, stability conditions impose bounds on the gains of the discrete-time controller and the sampling period and also a trade-off between the two. This paper shows a choice of task for which large sampling periods, necessitating low control gains for maintaining stability, lead to low teleoperation transparency and unacceptable task performance. It continues to show that users can successfully perform the same task if the controller is implemented using analog components. This highlights the advantages of analog haptics in tasks involving the display of highly stiff environments. The paper also highlights the constraints in designing analog haptic teleoperation controllers and proposes design guidelines to address them.

In order to enhance the dexterity of surgical instruments in robotic-assisted minimally invasive surgery, the robot is generally configured so as to have a wrist. However, this configuration has a problem in that there is a coupling of the motions of the wrist and the end-effector. In this paper an improved surgical instrument is proposed that eliminates the coupled motion using a compensation mechanism. The design concept behind the compensation mechanism can be applied to other types of surgical instruments. The performance of the proposed surgical instrument is validated by mechanical performance testing and animal experiments, which indicate that the problem of the coupled motion is successfully solved and the instrument is able to perform surgical tasks.

Optimization design for complex pipelines inside electromechanical products is a very difficult task within complex products such as cars, planes, ships and rockets. Thus, an optimization design for complex pipelines is proposed based on the flow resistance loss in this paper. The basic framework of the design includes three parts like pre-processing, evalution model and optimization search algorithm. Firstly, Monte Carlo pre-processing model is established to effectively reduce the complexity of the optimizaton design. Also, flow resistance loss model of complex pipelines with branches is constructed to evaluate design. Moreover, a novel particle swarm optimization (PSO) algorithm is presented to find an approximate optimal design. Finally, the comparison experiments and examples demonstrate that the optimization design is effective and practical.

Being the most important component of minimally invasive surgical robot system, remote centre mechanisms (RCM) composed of three joints, achieve the position and orientation adjustment of the surgical instrument inside a patient's body. In order to implement the high-precision position control and eliminate the adverse effect result from the friction of RCM's joints, in this paper, a fuzzy sliding mode controller with the friction compensation is designed. The result of simulation and experiment show that the controller designed can provide a trajectory tracking with real-time, high-precision performance and strong robustness.

This paper developed a simulation system for the training minimally invasive surgery (MIS). The simulation system has the capacity of providing the user with the security and real learning environment. The simulation system adopted Omega7 force sensing device as the input equipment offering position and posture information to the virtual robot. On the basis of the actual surgery robot model, we run the kernel simulation algorithm, which makes the surgical robot in the virtual environment imitate the real robot to complete operation action. At the same time, the user can be allowed to interact with the control panel in the interface, which has the same function as the real console, to control the virtual robot.

The stability of the spacecraft attitude is very important to the normal work of solar cells and the communication between the system and earth. Therefore a work mode of free floating space robot (FFSR) with zero-disturbance spacecraft attitude is presented; the dynamic equation of FFSR with zero-disturbance spacecraft attitude is derived based on Lagrange method; the smooth and consecutive joint trajectories are designed by adopting a planning method of trigonometric function according to the boundary conditions; the time distribution method of smooth segments to aim at the optimization of joint torques is investigated. The simulation results validate the method proposed, and the outcome sets a good foundation for the motion planning and control of FFSR with zero-disturbance spacecraft attitude.

In this paper, a sensor-based motion planning method for robot arm manipulators operating among unknown obstacles of arbitrary shape is presented. It can be applied to on-line collision avoidance with no prior knowledge of the obstacles. The sensitive skin is used to build a description of the robot’s surroundings. This approach is based on the configuration space but the construction of the C-obstacle surface is avoided. The motion planning algorithm consists of three phases. In each phase, the point automation moves along a specified plane, on which the mapping of the obstacles into configuration space can be simplified. Hence, the computation time is reduced and the algorithm can work in real time. The effectiveness of the proposed method is verified by a series of simulations.

A mobile robot operating in a real world environment rarely achieves the theoretical accuracy in positioning that is possible despite the use of precise manufacturing and high resolution encoders in drive motors. This is due to internal errors to a small degree, but mainly caused by minor variations in floor flatness. A vision system is developed and implemented for a mobile robot to correct orientation errors. Straight line ceiling features are used for reference orientation during navigation. An efficient and robust algorithm is developed, tested extensively and implemented in a mobile robot for actual navigation experiments. Preliminary experimental results show that simple visual servoing with proportional control can already achieve significant improvements.

A flexible manufacturing cell (FMC) consists of a machining center, robots, transportation devices and computers. In order to enable such a complex cell to run normally, one should examine the kinematical relationship of the components of the devices in the cell, test the accuracy of positioning and working cycles, and find troubles. This paper describes ideas of simulation and collisions detection and avoidance in a flexible manufacturing cell. The techniques of modeling cell collision avoidance and task programming are discussed in the paper. >

In order to make the invasive surgery more successful and more safe,a guiding robot is developed to control the active catheter in the invasive surgery.It moves in the manner of a snake utilizing a multi-joint mechanism driven by several shape memory alloy (SMA) actuators.In view of the mechanism and principle of the guiding robot driven by SMA actuators,a method to estimate the measure parameters of the bias spring is presented.At the same time,the kinematics analysis of the guiding robot is also accomplished by using the large deflection theory.Precondition of the known bending angle and orientation of the guiding robot,the SMA actuators' displacement and output force are deduced via integral transform and the accurate coordinates of the center in the guiding robot's front are gotten.Furthermore,the expressions for the calculation on the dimension parameters of the SMA actuators are deduced together with an integrated design theory for the guiding robot.A guiding robot prototype is designed by using the theory presented.With the help of a vascular model,the guiding robot-based invasive surgery is simulated.The research results provide integrated mathematic model for the design and analysis of the guiding robot and also perfect the design method and theory.