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This paper presents a method for mapping captured human motion with stepping to a humanoid model, considering the current state and the controller behavior. The mapping algorithm modifies the joint angle, trunk and center of mass (COM) trajectories so that the motion can be tracked and desired contact states can be achieved. The mapping is performed in two steps. The first step modifies the joint...
A filter for trajectories smoothing is presented. The filter provides an output reproducing the input trajectory if this is compliant with given constraints on the velocity, the acceleration and the torque required for tracking it. Otherwise, the filter approximates the input profile guaranteeing that the output trajectory satisfies all the kinematic and dynamic limits. The tracking of the input signal...
The present paper proposes the throwing manipulation method which cannot only control the position and orientation of the rigid object at the final goal, but also make the object track the desired trajectory which minimizes the impact at landing to avoid damages to the object as much as possible. Due to a model uncertainty, it is generally difficult to obtain the exact model and find appropriate control...
Hitting and batting tasks, such as tennis forehands, ping-pong strokes, or baseball batting, depend on predictions where the ball can be intercepted and how it can properly be returned to the opponent. These predictions get more accurate over time, hence the behaviors need to be continuously modified. As a result, movement templates with a learned global shape need to be adapted during the execution...
Dynamic parameters of a robot affect the performance of advanced control schemes significantly. In this study experiments to identify the dynamic parameters of AT2 robot are carried out. The excitation trajectory for identification is parameterized with Fourier series. The trajectory is optimized to minimize effects of uncertainty using condition number as the index. Recursive optimization is proposed...
In this paper, the optimum configuration of superfluous cables in redundant planar cable-suspended robots for minimum time trajectory is investigated. Both cable tensions and cable velocities are assumed to be limited. The bounds on the cable tensions and velocities are transformed into the bounds on the acceleration and velocity along the specified path. Assuming bang-bang control and using genetic...
In this paper we consider the problem of multi-objective trajectory planning to Parallel Kinematic Machines (PKMs). A two stage system is developed. In a first stage is an offline planning based on robot kinematics and dynamics, including actuators, is performed to generate a large dataset of trajectories, these trajectory cover mostly of the robot workspace and minimize time and energy, while avoiding...
In this paper, we develop an asymmetric s-curve profile method with jerk bounded to obtain high-precision motion and reduce the residual vibration. All possible instances for asymmetric s-curve profile planning are analyzed. The algorithm and its implementation are proposed with a direct and complete method. Simulation results are presented to verify the effectiveness and reliability of the proposed...
This paper presents a novel approach to on-line, robot-motion planning for multiple moving-objects interception with constant acceleration. The position, velocity and acceleration of the free particles TFL are used as a kinematic information to generate the multiple interception trajectory TFP. The polynomial interpolation technique is implemented in a 2 dof robot with an operational space control...
A technique for optimal trajectory planning of robot manipulators is presented. It consists of linking two points in the operational space while minimizing a cost function, taking into account dynamic equations of motion as well as bounds on joint velocities, accelerations, jerks and force/torques. We choose the cost function as a weighted balance of traveling time and mechanical energy of the actuators...
We consider the task of planning smooth trajectories for robot motion. In this paper we make two contributions. First we present a method for cubic spline optimization; this technique lets us simultaneously plan optimal task-space trajectories and fit cubic splines to the trajectories, while obeying many of the same constraints imposed by a typical motion planning algorithm. The method uses convex...
A 6-degree-of-freedom rigid robot arm and its throwing motion generation is described in this paper. The trajectories for the joint variables are generated off-line as a cubic spline obtained using general constrained nonlinear optimization, taking into consideration limitations (position, speed, acceleration and jerk) of the joint actuators, and the current limit of the whole structure. The obtained...
In this study, a controller for robotic motion based on neuroscientific principles was developed and implemented using an artificial neural element and a conventional robotic arm. With independent control over arm final position, velocity, acceleration, and deceleration, this system offers a more smooth, efficient and life-like motion than conventional open-loop methods. The system makes use of a...
This paper presents a comparative assessment of control schemes for vibration suppression and end-point trajectory tracking of a flexible robot manipulator. A constrained planar single-link flexible robot manipulator is considered and the dynamic model of the system is derived using the assumed mode method. To study the effectiveness of the controllers, initially a collocated PD controller is developed...
A new approach based on fuzzy genetic algorithm is developed to find the time-jerk synthetic optimal trajectory of robot with a joint space scheme using cubic splines. In order to get the optimal trajectory, cubic splines are employed and derived under the constraint condition of velocity and acceleration of the first and last point, which assure overall continuity of velocity and accelerations on...
Minimum-time path-tracking control of robotic manipulators assumes a relevant role in industrial applications where efficiency is an issue. On the other hand, minimizing the traveling time leads to an increment of the mechanical solicitations: the actuators dynamic limits can be easily exceeded. For this reasons, kinematic and/or dynamic constraints are normally taken into account when planning optimal...
The potential of multi-sensor integration in industrial manipulation systems is enormously high - and almost unused in real-world systems and applications. Scientific literature provides plenty of approaches for sensor integration, sensor-guided and sensor-guarded robot control, visual servoing, robot control architectures, and software systems, but it is still one of the major challenges to bring...
In order to track multiform curves planned for nonholonomic wheeled mobile robots stably, this paper presents an effective trajectory planning scheme and an improved tracking controller using a biological incentive model. The trajectory planning scheme, which includes a curvature estimator based on two adjacent points, combines the results of path planning with the policies of tracking.. The kinetic...
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