Parametric Identification for a Free-Floating Base Space Manipulator

2014 ◽  
Vol 490-491 ◽  
pp. 1151-1156
Author(s):  
William Takeshi Pereira ◽  
Tatiana F.P.A.T. Pazelli
Keyword(s):  
Parametric Identification ◽  
Torque Control ◽  
Least Square ◽  
Reference Trajectory ◽  
Space Manipulator ◽  
Floating Base ◽  
Computed Torque Control ◽  
Control Scheme ◽  
Two Degree Of Freedom ◽  
Computed Torque

In this paper parametric identification algorithms are applied to estimate dynamic parameters of a space manipulator, whose model is described through the Dynamically Equivalent Manipulator approach. Gradient and least-square methods are applied in order to evaluate capability of the schemes. A sufficiently rich input signal is applied as reference trajectory for joints position, while a simple model-based PID computed torque control scheme is responsible for keeping the trajectory tracking. Simulation results for a two degree-of-freedom space manipulator have shown the effectiveness of the proposal.

scholarly journals Obstacle Avoidance Using CTC and Virtual Structure for Leader-Follower Formation on Mobile Robot

2021 ◽  
Vol 5 (2) ◽  
Author(s):  
Maskhur Zulkarnain ◽  
Trihastuti Agustinah
Keyword(s):  
Mobile Robot ◽  
Obstacle Avoidance ◽  
Formation Control ◽  
Small Error ◽  
Torque Control ◽  
Reference Trajectory ◽  
Robot Trajectory ◽  
Computed Torque Control ◽  
Robot Position ◽  
Computed Torque

This research examined the development of the combination of virtual structure and leader-follower as an obstacle avoidance method in the formation control of a mobile robot. The formation of the robots are designed with the Separation Bearing Control (SBC) approach between the leader robot (RL) and the virtual robot (RV). The virtual robot is used as a virtual follower and a reference trajectory for the follower  robot (RF). When the follower robot detects an obstacle, the follower robot trajectory is adjusted using a trajectory planner for obstacle avoidance. After passing the obstacle, the follower robot will track its position back in formation using virtual robot position and heading as reference. Leader robot and follower are perturbed by disturbances. In order to ensure the achievement of small error tracking, a controller is designed using the integration of kinematic and dynamics controllers with disturbance observer. The kinematic and dynamics controllers are designed using input-output linearisation (IOL) method and computed torque control (CTC). The effectiveness of the proposed method is verified by the simulation result.Keywords: CTC, leader follower, obstacle avoidance, SBC, virtual structure. 

A genetic algorithm-based computed torque control for slider–crank mechanism in the ship’s propeller

2013 ◽  
Vol 228 (12) ◽  
pp. 2090-2099 ◽  
Author(s):  
Farsam Farzadpour ◽  
Hossein Faraji
Keyword(s):  
Genetic Algorithm ◽  
Position Control ◽  
Torque Control ◽  
Process Noise ◽  
Piston Cylinder ◽  
Computed Torque Control ◽  
Control Scheme ◽  
Crank Mechanism ◽  
Parameter Deviation ◽  
Computed Torque

A lot of endeavors regarding the development of slider–crank mechanism in the ship’s propeller have been made and continue to be investigated. This paper presents the position control of a slider–crank mechanism, which is driven by the piston cylinder actuator to adjust the blade pitch angle. An effective motion control strategy known as the computed torque control can ensure global asymptotic stability. However, it is essential for this control scheme to have a precise and accurate system model. Moreover, large amounts of changes in the output and even instability of process are caused by a small amount of measurement or process noise, when the derivative gain is sufficiently large. Accordingly, in order to compensate any parameter deviation and disturbances as well as minimizing errors, we have presented a genetic algorithm-based computed torque control system which adjusts the proportional-derivative gains. Computer simulations are performed which reveals that asymptotically stability is reached and it confirms the effectiveness and high tracking capability of the proposed control scheme.

An enhanced computed-torque control algorithm for robot manipulators

1998 ◽  
Vol 212 (1) ◽  
pp. 11-15 ◽  
Author(s):  
Q Li ◽  
S K Tso ◽  
A N Poo
Keyword(s):  
Control Algorithm ◽  
Internal Model Control ◽  
Torque Control ◽  
Simulation Studies ◽  
Control Approach ◽  
Computed Torque Control ◽  
Control Scheme ◽  
Model Control ◽  
Theoretical Analyses ◽  
Computed Torque

An enhanced computed-torque control approach, which is developed based on the intuitive design concept of the internal model control structure, is proposed in this paper. Both theoretical analyses and simulation studies on a two-link robot prove that the robustness of this enhanced algorithm can surpass that of the conventional computed-torque control scheme by a large extent.

A PD Computed Torque Control Method with Online Self-gain Tuning for a 3UPS-PS Parallel Robot

Robotica ◽  
2021 ◽  
pp. 1-13
Author(s):  
Xiaogang Song ◽  
Yongjie Zhao ◽  
Chengwei Chen ◽  
Liang’an Zhang ◽  
Xinjian Lu
Keyword(s):  
Feedback Loop ◽  
Control Method ◽  
Virtual Work ◽  
Parallel Robot ◽  
Torque Control ◽  
Virtual Work Principle ◽  
Tuning Method ◽  
Computed Torque Control ◽  
Control Feedback ◽  
Computed Torque

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.

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