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Modeling complicated dynamics of humanoids is considered in this paper. It is proposed that the three-link module is a pivotal element in formulation of high-dimensional humanoids. The equations of motion of the module are first derived by projection of the free body equations of motion onto the space of the translation of an arbitrary point and Bryant angles and angular velocities. It is then shown...
A decentralized control law using a backstepping scheme is proposed to deal with a leader follower multiple robots structure. The coordination strategy combines the leader follower control with the decentralized control. In fact, in the proposed approach, each follower robot only needs the information exchange with its connected neighbors and does not assume the existence of direct communication channel...
The interaction between the snake-like robot and environment produces serpentine action to push the body forward. A slender body shape made from many modules occupies a larger scale. In this paper, snake-like robot motion planning method is analyzed by considering each module's position and its movement as well as position of obstacles. The Potential Energy Function between each module and obstacles...
The identification method for industrial manipulators considering physical consistency such as positive definiteness of inertial parameters has been developed, however it has to solve the quadratic programming with the non-linear inequality constraints. In identifying the large DOF systems like humanoid robots, the converged solution is difficult to be obtained. In this paper, we propose the method...
In this paper, a nonlinear passivity-based control strategy based on stability in the sense of Lyapunov (Second method) and sliding mode control applied to Euler-Lagrange systems (robot arms) and extended to the PHANToM Premium 1.0 haptic device for purposes of local haptic guidance rehabilitation and medical diagnosis in people who have some motor impairment (on upper limb) is designed and implemented.
This paper presents the design of a motion control strategy based on passivity theory and energy analysis applied to Euler-Lagrange (E-L) systems, particularly to robot manipulators and with purpose to haptic devices. The performance of a robotic structure depends of a proper design of a motion control technique in a regulation action or trajectory tracking in its workspace. With the purpose to proof...
In this paper a PID control applied particularly in robot manipulators. To understand the development of the proposal presents a mathematical preliminary section we used, we explicitly describe relevant aspects of kinematics and dynamics of the haptic device Phantom Premium 1.0, technology and mathematical models, and the design and experimental results of PID control based on passivity, the type...
This paper proposes repeatedly direct kinematics (RDK) algorithm to trajectory generation of a multi-joint robot in lift-down movements. For trajectory generation of the multi-joint robot, three constraints are considered. They are no turnover, the joint limits and the torque limits of the robot. Safety factor is set in order to ensure the stability of robot. The emphasis of the study is placed on...
This paper analyzes cause of control errors for 5 DOF exoskeleton upper-limb rehabilitation robot. Based on the method of typical repetitive control, let multiple improved repetitive control loops with filtering parallel embed into closed-loop of control system in order to eliminate motion error of rehabilitation robot with multi-channel periodic input signal. The simulation results show that the...
In this paper we develop a dynamic model to mimic and simulate human falling process when tripping over an obstacle. The work consists of three parts. First a 5-link bipedal model is established, the joint trajectories of knee and hip are generated. Next several constraints are taken into consideration, which take the physical, physiological and environmental constraints into consideration. Hence...
We have previously shown that hemispherical soft fingertips are at equilibrium when they are in contact with objects, suggesting that the contact force and flexibility of these soft fingertips are important for stable grasping and manipulation. Hence, by making use of these characteristics, soft fingers can manipulate objects dexterously. While our previous work has focused on pairs of 1-DOF fingers...
For the typical non-linear robot control system, this paper proposes a class of sliding mode variable structure control method (SMVSC) based on RBF neural network, and the controller's output is added a low-pass filter. A two-joint robot is the research object, This method apply a powerful learning and processing power of RBF network as the sliding mode controller for uncertain part, and resolves...
We consider a class of linear flexible mechanical systems arising from the dynamics of animal locomotion. A distinctive property of such systems is that the stiffness matrix is asymmetric. Extending the standard notion to this class, we define the natural oscillation as a free response under the damping compensation to achieve marginal stability. As a benchmark, a link chain system in a fluid environment...
The paper describes the model of a two flexible joint manipulator and the development of a nonlinear passivity based control method for that model. For dynamic modeling, the Euler-Language approach is selected to model flexible joint manipulator. Since lightweight materials are employed in the construction of manipulator, the assumption that negligible link deformation no longer applies. A nonlinear...
In this paper, we propose a control algorithm for stabilizing of an unmanned bicycle at zero speed by using a nonlinear control based on an output-zeroing controller. The simplified model of the bicycle with the balancer is derived from Lagrangian and nonholonomic constraints with respect to translation and rotation relative to the ground plane. We derived a controller using a steering torque and...
This paper proposes a novel control method for stable grasping using a multi-fingered hand-arm system with soft hemispherical finger tips. The proposed method is simple but easily achieves stable grasping of an arbitrary polyhedral object using an arbitrary number of fingers. Firstly, we formulate nonholonomic constraints between a multi-fingered hand-arm system and an object constrained by rolling...
This paper presents tracking and set point controllers for parallel mechanism based on the notion of a projection operator. The controller reported here works whether the system is overactuated or not; plus one does not need to derive the minimal-order dynamics model of the system. Since the dimension of projection matrix is fixed, the projection-based controller does not need to change its structure...
This paper suggests two advantages of the biarticular muscle which has been said to play an important role in human's motion control; one is stiffness direction stabilization of an end effector which results in stabilization of the posture, and the other is inertia matrix diagonalization in the dynamics of a robot manipulator. In order to analyze these characteristics, we adopt three-pair six-muscle...
PenduBot is a new experiment object in the control theory and a typical representation in the underactuated robot, so it is the research focus of control and robot domain. It is known for its strongly nonlinear and naturally unstable properties. To stabilize the PenduBot and verify the control abilities of the algorithm on strongly nonlinear and naturally unstable properties, the thesis presents the...
The trajectory is one of major issues for a humanoid robot because not every trajectory can provide a stable robot motion. In this paper, a real human motion is used to generate a robot trajectory. Image processing and transformation are used to extract the trajectory from a human motion to a robot trajectory. The dynamic stability of a robot is considered by using the zero moment point (ZMP) because...
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