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In this paper, we present a new concept of multi-legged seabed robot for high tidal current environment. The robot moves on seabed by walking with 4 or 6 legs which is different moving mechanism from the existing underwater thrust system such as screw or Caterpillar. The main concept to endure the high current is utilization of hydrodynamic forces acting on the body and legs. The advantage of this...
As an important area of the high-tech research, robotics technology is attached importance by governments. It has become important equipment in manufacturing of a country's manufacture level and technological level. Robot kinematics analysis is the basis of robot motion control. According to the specific characteristics of MOTOMAN-HP20 manipulator, this paper established a kinematics model and set...
This paper proposes a general motion planning and coordination strategy for robot systems. The representation space (RS) of a robot system is constructed to describe the distributions of system attributes. The reachable area in the RS, denoting the attribute set that the system can be of, indicates the system's ability to accomplish tasks. Moreover, it also describes the influences of the internal...
This article is aimed at presenting a technique to generate bipedal walking trajectories that can be applied to humanoid robots. The proposed method is based on maintatining the dynamic balance by using the ZMP criterion throughout single support phases. To be able to reach this goal, we employed ZMP equations in spherical coordinates, so that the rate change of intrinsic angular momentum terms in...
Applying reinforcement learning to humanoid robots is challenging because humanoids have a large number of degrees of freedom and state and action spaces are continuous. Thus, most reinforcement learning algorithms would become computationally infeasible and require a prohibitive amount of trials to explore such high-dimensional spaces. In this paper, we present a probabilistic reinforcement learning...
A trajectory tracking control scheme of a Macro-Micro welding robot based on the vision navigation is proposed. The robot system is composed of macro manipulator and micro manipulator attached to the tip of the macro part. Based on the visual sense, the robot is capable of effectively realizing the teaching mode and real-time tracking mode simultaneously, which is quite advantage to achieve better...
This paper considers path following control of snake robots along straight paths. A controller is proposed which, under the assumption that the forward velocity of the snake robot is nonzero and positive, guarantees K-exponential stability of the distance between the snake robot and the desired path and also K-exponential stability of the heading of the robot with respect to the direction of the path...
This paper deals with the trajectory planning of a full-rotate parallel robot for wafer transfer operations. With the path length in work space of the robot as parameter, the dynamic model is parameterized. The system constraints-input torque and velocity constraints and the task constraints-output velocity, acceleration, and jerk limits are set; with the minimized operation time as the optimization...
A new algorithm based on Evolutionary Strategies is proposed for finding a robot manipulation path. Next scenario is considered: Given a learned Manipulation Path in the space of configurations, a real-time optimal path is calculated when mobile robot base is in a different position and orientation near to the original localization. The optimization problem is formulated as the minimization of the...
In this paper, stable hopping of a one-legged, articulated robot with a flat foot is investigated. The robot has a special feature that before taking off, it goes through an underactuated phase in which the foot rotates about the unactuated toe on the ground. By having the underactuated phase, the robot can perform stable human-like hops with longer hopping distances. To devise a systematic trajectory...
In the forest industry, trees are logged and harvested by human-operated hydraulic manipulators. Eventually, these tasks are expected to be automated with optimal performance. However, with todays technology the main problem is implementation. While prototypes may have rich sensing information, real cranes lack certain sensing devices, such as encoders for position sensing. Automating these machines...
Optimal trajectory planning for robot manipulators is a very important issue in the research field of robotics. Many applications require smooth trajectories and the minimization of a performance index, usually the traveling time or the mechanical energy of the actuators. This paper presents a novel method that uses eighth-degree polynomial functions to generate smooth trajectories for the parametric...
The trajectory of a revolute welding robot with six joints was planned in order to make the trajectory smooth and working time optimal. The time intervals between each point to be welded in Cartesian space were coded in binary, and the trajectory was implemented using an adaptive genetic algorithm while considering constraints of displacement, velocity, acceleration and jerk of each joint. According...
ROBONOVA-1 robot is a kind of new type humanoid robot, which can offer educators, students and robotic hobbyists a complete robot package. In order to better study and develop the function of this robot, according to the analysis of its configuration and gait, a seven bar linkage mechanism is established. The lateral walking trace of the robot is planned by using the method of geometry constraints...
This paper describes a hierarchical planner deployed on a mobile manipulation system. The main idea is a two-level hierarchy combining a global planner which provides rough guidance to a local planner. We place a premium on fast response, so the global planner achieves speed by using a very rough approximation of the robot kinematics, and the local planner begins execution of the next action even...
This paper discusses how mobile manipulators with an under-actuated vertical arm can be designed to be differentially flat. The property of differential flatness is achieved by appropriate inertia redistribution of the vertical arm and a wide range of under-actuation becomes possible. As a result of having the flatness property, the under-actuated mobile manipulators are capable of executing point-to-point...
Trajectory planning and optimization is a fundamental problem in articulated robotics. It is often viewed as a two phase problem of initial feasible path planning around obstacles and subsequent optimization of a trajectory satisfying dynamical constraints. There are many methods that can generate good movements when given enough time, but planning for high-dimensional robot configuration spaces in...
We present a novel combination of motion planning techniques to compute motion plans for robotic arms. We compute plans that move the arm as close as possible to the goal region using sampling-based planning and then switch to a trajectory optimization technique for the last few centimeters necessary to reach the goal region. This combination allows fast computation and safe execution of motion plans...
The CMAC-based algorithm of critics & strategists is proposed in this article for application on robot tracking control. This tracking controller comprises position tracking controller and angle tracking controller, whose outputs are line rotation speed control value and angle control value respectively. Both of them include in two CMAC controllers dealing with online weight value adjustment through...
Based on the concept of kinematical controllability, we can decouple the trajectory planning of an acrobot into two steps: finding a path in a configuration space and time-scaling it. In this paper, we apply this concept and plan the swing-up motion of an acrobot based on its falling-down motion. First, the initial state of the acrobot is set to the unstable upright equilibrium position, and the movement...
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