A Study on Development of a Hybrid Aerial/Terrestrial Robot System for Avoiding Ground Obstacles by Flight

To date, many studies related to robots have been performed around the world. Many of these studies have assumed operation at locations where entry is difficult, such as disaster sites, and have focused on various terrestrial robots, such as snake-like, humanoid, spider-type, and wheeled units. Another area of active research in recent years has been aerial robots with small helicopters for operation indoors and outdoors. However,less research has been performed on robots that operate both on the ground and in the air. Accordingly, in this paper, we propose a hybrid aerial/terrestrial robot system. The proposed robot system was developed by equipping a quadcopter with a mechanism for ground movement. It does not use power dedicated to ground movement, and instead uses the flight mechanism of the quadcopter to achieve ground movement as well. Furthermore, we addressed the issue of obstacle avoidance as part of studies on autonomous control. Thus, we found that autonomous control of ground movement and flight was possible for the hybrid aerial/terrestrial robot system, as was autonomous obstacle avoidance by flight when an obstacle appeared during ground movement.

Robotic Walker for Slope Mobility Assistance with Active-Passive Hybrid Actuator

Walking assistance can be realized by active and passive robotic walkers when their users walk on even roads.However,fast signal processing and real-time control are necessary for active robotic walkers when the users walk on slopes,while assistive forces cannot be provided by passive robotic walkers when the users walk uphill.A robotic walker with an active-passive hybrid actuator(APHA)was developed in this study.The APHA,which consists of a rotary magnetorheological(MR)brake and a DC motor,can provide mobility assistance to users walking both uphill and downhill via the cooperative operation of the MR brake and DC motor.The rotary MR brake was designed with a T-shaped configuration,and the system was optimized to minimize the brake volume.Prototypes of the APHA and robotic walker were constructed.A control algorithm for the robotic walker was developed based on the characteristics of the APHA and the structure of the robotic walker.The mechanical properties of the APHA were characterized,and experiments were conducted to evaluate the mobility assistance supplied by the robotic walker on different roads.The results show that the APHA can meet the requirements of the robotic walker,and suitable assistive forces can be provided by the robotic walker,which has a simple mechanical structure and control method.

The kinematics modeling based on Spinor theory for CT-guided hybrid robot

This paper focused on a simplified method for solving the hybrid robot kinematics in CT-guided （computerized tomography, CT） surgery. By position constraint introduced, the hybrid robot can be transformed as a redundant serial 7-DOF robot. The forward displacement calculation was developed based on the product-of-exponential formula （POE）. Because of the kinematics complexity of the hybrid and redundant robot, the combination technique of Ulrich two-step iteration method and paul variables detachment method （UTI-PVD） was introduced to fulfill the inverse kinematics of redundant robot, the novelty of which lay in the flexibility of various robots structures and in high calculation efficiency for realtime control. The process of solving the inverse displacement was analyzed. The UTI-PVD method can be applicable to kinematics of many robots, especially for redundant robots with more than 6DOF. The kinematics simulation was provided, and robot dexterity analysis was presented. The results indicated that the hybrid robot could implement the minimally invasive CT-guided surgery.

Design of Underwater Robot Lines Based on a Hybrid Automatic Optimization Strategy

In this paper, a hybrid automatic optimization strategy is proposed for the design of underwater robot lines. Isight is introduced as an integration platform. The construction of this platform is based on the user programming and several commercial software including UG6.0, GAMBIT2.4.6 and FLUENT12.0. An intelligent parameter optimization method, the particle swarm optimization, is incorporated into the platform. To verify the strategy proposed, a simulation is conducted on the underwater robot model 5470, which originates from the DTRC SUBOFF project. With the automatic optimization platform, the minimal resistance is taken as the optimization goal;the wet surface area as the constraint condition; the length of the fore-body, maximum body radius and after-body＇s minimum radius as the design variables. With the CFD calculation, the RANS equations and the standard turbulence model are used for direct numerical simulation. By analyses of the simulation results, it is concluded that the platform is of high efficiency and feasibility. Through the platform, a variety of schemes for the design of the lines are generated and the optimal solution is achieved. The combination of the intelligent optimization algorithm and the numerical simulation ensures a global optimal solution and improves the efficiency of the searching solutions.

Compliant landing of a trotting quadruped robot based on hybrid motion/force robust control

A compliant landing strategy for a trotting quadruped robot on unknown rough terrains based on contact force control is presented. Firstly, in order to lower the disturbance caused by the landing impact force, a landing phase is added between the swing phase and the stance phase, where the desired contact force is set as a small positive constant. Secondly, the joint torque optimization of the stance legs is formulated as a quadratic programming(QP) problem subject to equality and inequality/bound constraints. And a primal-dual dynamical system solver based on linear variational inequalities(LVI) is applied to solve this QP problem. Furthermore, based on the optimization results, a hybrid motion/force robust controller is designed to realize the tracking of the contact force, while the constraints of the stance feet landing angles are fulfilled simultaneously. Finally, the experiments are performed to validate the proposed methods.

Hybrid input shaping control scheme for reducing vibration of robot based on multi-mode control

The classic multi-mode input shapers(MMISs)are valid to decrease multi-mode residual vibration of manipulators or robots simultaneously.But these input shapers cannot suppress more residual vibration with a quick response time when the frequency bandwidth of each mode vibration is very different.The methodologies and various types of multi-mode classic and hybrid input shaping control schemes with positive impulses were introduced in this paper.Six types of two-mode hybrid input shapers with positive impulses of a 3 degree of freedom robot were established.The ability and robustness of these two-mode hybrid input shapers to suppress residual vibration were analyzed by vibration response curve and sensitivity curve via numerical simulation.The response time of the zero vibration-zero vibration and derivative(ZV-ZVD)input shaper is the fastest,but the robustness is the least.The robustness of the zero vibration and derivative-extra insensitive(ZVD-EI)input shaper is the best,while the response time is the longest.According to the frequency bandwidth at each mode and required system response time,the most appropriate multi-mode hybrid input shaper(MMHIS)can be selected in order to improve response time as much as possible under the condition of suppressing more residual vibration.

Analysis on the crossing obstacle of wheel-track hybrid mobile robot

A novel wheel-track hybrid mobile robot with many movement patterns is designed.According to different environments,it can switch between the pure wheel pattern and the pure track one.According to a homogeneous coordinate transformation matrix,gravity stability and its obstacle performance are analyzed.Its gravity equation and climbing obstacle conditions are established.Experimental results show that this hybrid mobile robot could fully possess the advantages of both the wheel and the track mechanisms and achieve a good obstacle climbing capability.

Hybrid force control of astronaut rehabilitative training robot under active loading mode

In order to mitigate the effects of space adaptation syndrome(SAS) and improve the training efficiency of the astronauts, a novel astronaut rehabilitative training robot(ART) was proposed. ART can help the astronauts to carry out the bench press training in the microgravity environment. Firstly, a dynamic model of cable driven unit(CDU) was established whose accuracy was verified through the model identification. Secondly, to improve the accuracy and the speed of the active loading, an active loading hybrid force controller was proposed on the basis of the dynamic model of the CDU. Finally, the actual effect of the hybrid force controller was tested by simulations and experiments. The results suggest that the hybrid force controller can significantly improve the precision and the dynamic performance of the active loading with the maximum phase lag of the active loading being 9° and the maximum amplitude error being 2% at the frequency range of 10 Hz. The controller can meet the design requirements.

Hybrid Visual Servoing Control for Robotic Arc Welding Based on Structured Light Vision

A novel hybrid visual servoing control method based on structured light vision is pro-posed for robotic arc welding with a general six degrees of freedom robot. It consists of a positioncontrol inner-loop in Cartesian space and two outer-loops. One is position-based visual control inCartesian space for moving in the direction of weld seam, i.e., weld seam tracking, another is image-based visual control in image space for adjustment to eliminate the errors in the process of tracking.A new Jacobian matrix from image space of the feature point on structured light stripe to Cartesianspace is provided for dierential movement of the end-e?ector. The control system model is simplifiedand its stability is discussed. An experiment of arc welding protected by gas CO2 for verifying iswell conducted.

Collision avoidance for a mobile robot based on radial basis function hybrid force control technique

Collision avoidance is always difficult in the planning path for a mobile robot. In this paper, the virtual force field between a mobile robot and an obstacle is formed and regulated to maintain a desired distance by hybrid force control algorithm. Since uncertainties from robot dynamics and obstacle degrade the performance of a collision avoidance task, intelligent control is used to compensate for the uncertainties. A radial basis function （RBF） neural network is used to regulate the force field of an accurate distance between a robot and an obstacle in this paper and then simulation studies are conducted to confirm that the proposed algorithm is effective.

Docking process on hybrid self-reconfigurable modular robots

A novel hybrid self-reconfigurable modular robot is designed to finish the morphing action from line shape to hexagon shape. The robot is composed of many basic modules,each of which consists of a master module and a slave module in the shape of triangular prism. There are four connection ports on each basic module. For the master module there are two holes on each connection port,and for the slave one there are two pegs on each connection. The docking process between two neighboring basic modules is analyzed with a peg-in-hole mechanical structure. A small motion's method is presented and the contact forces are derived. According to the force/moment,the pose of a motion module should be adjusted to make two neighboring modules align and finish the docking process.Finally,a simulation of 3 basic modules is shown to finish the morphing and docking process effectively. The system can finish the morphing task from the line shape to the hexagon shape.

Dynamics of 3-DOF Hybrid Robot Manipulator

This paper introduces a 3-dof hybrid robotic manipulator which is constructed by combining a parallel mechanism and a pantograph to increase stiffness as well as workspace. And by analyzing its kinematics and dynamics with Lagrange’s method, the dynamic model is obtained which is essential for feed-forward control of the manipulator. An explicit solution is given out. Finally, a simulation test is carried out on computers.

Motion design of a hybrid wheeled/legged robot for lunar exploration

The robot consists of a quadruped mechanism and two active dual-wheel casters possesses the advantages of wheeled and legged mechanism, and can quickly move on the relatively plane ground with the wheeled mechanism, and can walk on the extremely uneven terrain with the legged mechanism. The effectiveness of the motion design of the hybrid robot is iHustrated by simulation results.

A Sensing and Robot Navigation of Hybrid Sensor Network

Traditional sensor network and robot navigation are based on the map of detecting fields available in advance. The optimal algorithms are explored to solve the energy saving, shortest path problems, etc. However, in practical environment, there are many fields, whose map is difficult to get, and need to detect. This paper explores a kind of ad-hoc navigation algorithm based on the hybrid sensor network without the prior map. The system of navigation is composed of static nodes and mobile nodes. The static nodes monitor events occurring and broadcast. In the system, a kind of cluster broadcast method is adopted to determine the robot localization. The mobile nodes detect the adversary or dangerous fields and broadcast warning message. Robot gets the message and follows ad-hoc routine to arrive the events occurring place. In the whole process, energy saving has taken into account. The algorithms of nodes and robot are given in this paper. The simulate and practical results are available as well.

Application of Artificial Neural Network in Robotic Hybrid Position/Force Control

A hybrid position/force controller is designed for the joint 2 and the joint 3 of thePUMA 560 robot.The hybrid controller includes a multilayered neural network,which canidentify the dynamics of the contacted environment and can optimize the parameters of PIDcontroller.The experimental results show that after having been trained,the robot has sta-ble response to the training patterns and strong adaptive ability to the situation between thepatterns.

Robot Positioning and Navigation Based on Hybrid Wireless Sensor Network

Traditional sensor network and robot navigation are based on the map of detecting the fields available in advance. The optimal algorithms are developed to solve the energy saving, the shortest path problems, etc. However, in the practical enviroranent, there are many fields, whose map is difficult to get, and needs to be detected. In this paper a kind of ad-hoc navigation algorithm is explored, which is based on the hybrid sensor network without the prior map in advance. The navigation system is composed of static nodes and dynamic trades. The static nodes monitor the occurrances of the events and broadcast them. In the syston, a kind of algorithm is to locate the rdbot, which is based on duster broadcasting. The dynamic nodes detect the adversary or dangerous fields and broadcast warning messages. The robot gets the message and follows ad-hoc routine to arrive where the events occur. In the whole process, energy saving has been taken into account. The algorithms, which are based on the hybrid sensor network, are given in this paper. The simulation and practical results are also available.

基于改进Hybrid A^(*)算法的阿克曼移动机器人路径规划

针对移动机器人路径规划的效率和所规划路径的安全性问题,基于阿克曼六轮转向模型,提出了一种基于改进Hybrid A^(*)算法的路径规划方法。通过改进Hybrid A^(*)算法中的启发式函数,引入距离惩罚函数,减少了节点搜索数量;通过构建安全走廊,引导移动机器人尽可能远离障碍物;在代价函数中加入了节点向前、换向和向后扩展的惩罚项,确保所规划路径的可执行性与安全性。通过仿真表明,基于改进Hybrid A^(*)算法的路径规划方法适用于阿克曼六轮移动机器人,提高了路径规划的效率,规划的路径更具安全保障。

改进Hybrid A^(*)的拖挂式移动机器人路径规划算法

为了提高传统Hybrid A^(*)算法的路径规划效率和安全系数,提出一种改进的Hybrid A^(*)路径规划算法,并将此算法应用在拖挂式移动机器人系统上。首先,对启发函数进行改进,以减少路径规划过程中的计算量,从而提高规划效率;其次,设计障碍惩罚函数,进而实现提前避开行进路径上的障碍物,避免在U型障碍中陷入局部最优解;最后,考虑到拖挂式机器人模型结构的特殊性,无法将其视为质点,为此采用碰撞检测算法来提高规划路径的合理性和准确性。仿真试验验证,提出的改进Hybrid A^(*)路径规划算法可适用于拖挂式机器人系统,且具有规划效率和安全性能高、路径平滑等特点,为其在实际应用中的路径规划提供理论依据。

模糊Hybrid控制及其在机器人装配作业中的应用

本文根据模糊推理原理，提出了模糊混合（Ｈｙｂｒｉｄ）控制方法，并把它用于三自由度机械人的回柱二维插入过程中，实验结果表明，该方法能使振动幅度减少９５％以上，并消除了阻塞现象，更好地完成插入任务。

ROBOT软件在特种结构的应用

介绍ROBOT软件几个可用于特种结构的典型功能,以及分析弹性地基板、组合结构、多种材料组合截面和拉索结构时要注意的问题。结合具体实例给出了处理方法,并验证结果的准确性。