scholarly journals Control par calculado para seguimiento de trayectoria aplicado a la dinámica de un robot de 3gdl con propósitos didácticos

Author(s):  
Juan Carlos Hernández-Durón ◽  
José Luis Ortiz-Simón ◽  
Martha Aguilera-Hernandez ◽  
Daniel Olivares-Caballero

The article shows the needed procedure to obtain the dynamic model of a robot, with the purpose of being able to follow a planned path using the control law “CTC” Computed Torque Control. The robot was designed in a simple way for didactic reasons, this robot has three degrees of freedom, four links and three joints to move around in the work place. Two out of these joints are rotatory joints meanwhile the third one is a prismatic joint. The dynamic model of the robot is obtained using the Jacobians and Christoffel symbols of the center of mas of each link. Also including the Gravitational vector and the frictions of each joint. The objective of the dynamic model is to be able to simulate the robot in “Simulink” and test different paths using the computed torque control in which the gains of the control will be manipulated until a value that satisfies the desired path is found

1995 ◽  
Vol 117 (1) ◽  
pp. 31-36 ◽  
Author(s):  
I. M. M. Lammerts ◽  
F. E. Veldpaus ◽  
M. J. G. Van de Molengraft ◽  
J. J. Kok

This paper presents a motion control technique for flexible robots and manipulators. It takes into account both joint and link flexibility and can be applied in adaptive form if robot parameters are unknown. It solves the main problems that are related to the fact that the number of degrees of freedom exceeds both the number of actuators and the number of output variables. The proposed method results in trajectory tracking while all state variables remain bounded. Global, asymptotic stability is ensured for all values of the stiffnesses of joints and links. To show the characteristics of the proposed control law, some simulation results are presented.


Author(s):  
La´szlo´ L. Kova´cs ◽  
Jo´zsef Ko¨vecses ◽  
Ambrus Zelei ◽  
La´szlo´ Bencsik ◽  
Ga´bor Ste´pan

This paper aims to generalize the computed torque control method for underactuated systems which are modeled by a non-minimum set of generalized coordinates subjected to geometric constraints. The control task of the underactuated robot is defined in the form of servo constraint equations that have the same number as the number of independent control inputs. A PD controller is synthesized based on projecting the equations of motion into the nullspace of the distribution matrix of the actuator forces/torques. The results are demonstrated by numerical simulation and experiments conducted on a two degrees-of-freedom device.


Robotica ◽  
2012 ◽  
Vol 31 (2) ◽  
pp. 203-216 ◽  
Author(s):  
Asier Zubizarreta ◽  
Itziar Cabanes ◽  
Marga Marcos ◽  
Charles Pinto

SUMMARYThe use of extra sensors in parallel robots can provide an increase in control performance, making it possible to fully exploit the potential of these mechanisms. In this paper, a comprehensive redundant dynamic modelling procedure for the six-degree-of-freedom Gough platform is presented. The proposed methodology makes it possible to define the model in terms of all sensorized joint variables in order to implement redundant information-based control, and an example, the Extended Computed Torque Control (Extended CTC) approach, is developed. This, applied to parallel robots, ensures better dynamic performance than the traditional CTC approach. In order to validate dynamic modelling, a two-step procedure is used in this paper. First, the redundant dynamic model is validated by comparing its dynamic performance with the previous research in the field. Second, an exhaustive study is carried out that demonstrates the advantages of the redundant dynamic model when used in the Extended CTC approach.


Author(s):  
Zexiao Xie ◽  
Ben Ma ◽  
Ping Ren

This paper presents the design of a computed torque controller for a two-degree-of-freedom (two-dof) cable-suspended parallel mechanism. Unlike fully constrained cable-driven parallel mechanisms, cable-suspended parallel mechanisms are not redundantly actuated and usually have the same number of actuated cables as the degrees of freedom. Compared with rigid-link parallel mechanisms, the control of cabled parallel mechanisms is more challenging in that the cable tensions are unidirectional. Taking the input constraints into account, the method of computed torque control is applied to the two-dof planar cable robot. The sufficient conditions and necessary & sufficient conditions of the controller’s parameters are obtained, under which the positiveness of the tensions is always maintained during the point-to-point motion within the cable robot’s static workspace. Numerical simulations show that the controller is computationally efficient and the end-effector of the robot could converge to desired final positions with exponential stability.


Author(s):  
Jolly Atit Shah ◽  
S S Rattan

<p>Due to their advantage of high speed, accuracy and repeatability, robot manipulators have become major component of manufacturing industries and even now a days they become part of routine life.            </p><p>Two link robot manipulator is a very basic classical and simple example of robot followed in understanding of basic fundamentals of robotic manipulator. The equation of motion for two link robot is a nonlinear differential equation. For higher degrees of freedom, as the closed form solutions are very difficult we have to use numerical solution. Here we focused mainly on control of robot manipulator to get the desired position using combination of two classical methods PID and computed torque control method after deriving the equation of motion. For the same simulation is represented using MATLAB and compared with computed torque control method.</p>


Robotica ◽  
2021 ◽  
pp. 1-13
Author(s):  
Xiaogang Song ◽  
Yongjie Zhao ◽  
Chengwei Chen ◽  
Liang’an Zhang ◽  
Xinjian Lu

SUMMARY In this paper, an online self-gain tuning method of a PD computed torque control (CTC) is used for a 3UPS-PS parallel robot. The CTC is applied to the 3UPS-PS parallel robot based on the robot dynamic model which is established via a virtual work principle. The control system of the robot comprises a nonlinear feed-forward loop and a PD control feedback loop. To implement real-time online self-gain tuning, an adjustment method based on the genetic algorithm (GA) is proposed. Compared with the traditional CTC, the simulation results indicate that the control algorithm proposed in this study can not only enhance the anti-interference ability of the system but also improve the trajectory tracking speed and the accuracy of the 3UPS-PS parallel robot.


2021 ◽  
pp. 1-9
Author(s):  
G. Perumalsamy ◽  
Deepak Kumar ◽  
Joel Jose ◽  
S. Joseph Winston ◽  
S. Murugan

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