scholarly journals Experimental dual-mode control of a flexible robotic arm

Robotica ◽  
1992 ◽  
Vol 10 (2) ◽  
pp. 135-145 ◽  
Author(s):  
Woosoon Yim ◽  
Jichun Zuang ◽  
Sahjendra Singh
Keyword(s):  
Target Position ◽  
Terminal State ◽  
Pole Placement ◽  
Robotic Arm ◽  
Dual Mode ◽  
Elastic Mode ◽  
Single Link ◽  
On Line ◽  
Feedforward Controller ◽  
Placement Technique

SUMMARYThis paper focuses on the implementation of a dual-mode controller for the maneuver of a single link flexible robotic arm. The joint angle trajectory tracking is accomplished by a proportional and derivative PD and a feedforward controller. Based on the pole placement technique, a linear stabilizer is designed for elastic mode stabilization. The stabilizer is switched on when the trajectory reaches the vicinity of the terminal state, and the effect of switching time on arm vibration is investigated. An optical deflection sensor is used for on-line measurements of elastic deflections, and also used for the prediction of the static deflection of the arm in the target position. The robustness of the linear stabilizer at varying pay loads is presented.

Sliding Mode Control and Elastic Mode Stabilization of a Robotic Arm With Flexible Links

1991 ◽  
Vol 113 (4) ◽  
pp. 669-676 ◽  
Author(s):  
P. J. Nathan ◽  
S. N. Singh
Keyword(s):  
Closed Loop ◽  
Joint Angle ◽  
Sliding Mode ◽  
Variable Structure ◽  
Terminal State ◽  
Loop System ◽  
Robotic Arm ◽  
Closed Loop System ◽  
Elastic Mode ◽  
Mode Stabilization

This paper treats the question of control of an elastic robotic arm of two links based on variable structure system (VSS) theory and pole assignment technique for stabilization. A discontinuous joint angle control law, based on VSS theory, is designed which accomplishes asymptotic decoupled joint angle trajectory tracking. In the closed-loop system, the trajectories are attracted toward a chosen hypersurface in the state space and then slide along it. Although, joint angles are controlled using variable structure control (VSC) law, the flexible modes of the links are excited. Using center manifold theory, it is shown that the closed-loop system, including the sliding mode controller, is stable. Based on a linearized model about the terminal state, a stabilizer is designed using pole assignment technique to control the elastic oscillations of the links. A control logic is included which switches the stabilizer at the instant when the joint angle trajectory enters a specified neighborhood of the terminal state. Simulation results are presented to show that in the closed-loop system, accurate joint angle trajectory tracking, and elastic mode stabilization are accomplished in the presence of payload uncertainty.

Control of Flexible Beam with Unmodelled Dynamics Using Second-Order Pole Placement and LQR Techniques

2013 ◽  
Vol 393 ◽  
pp. 675-682 ◽  
Author(s):  
Z.A. Rahman ◽  
A.A. Mat Isa ◽  
Haydar H. Ali ◽  
M.A. Anuar
Keyword(s):  
Nonholonomic Constraints ◽  
Second Order ◽  
Pole Placement ◽  
Flexible Beam ◽  
Flexible Link ◽  
Intrinsic Nature ◽  
Order Pole ◽  
Flexible Arm ◽  
Single Link ◽  
Mechanical Devices

Control of a flexible beam such as that in flexible-link robot manipulators in many mechanical devices is very challenging, due in part to its intrinsic nature of unmodelled dynamics in a system. Such a system is said to be subjected to nonholonomic constraints, hence its feedback control is difficult to realize. This paper presents the application of control design based on second-order pole placement and LQR approaches to a single-link flexible robotic arm. In this case, a controller considering the flexibility of highly-flexible arm is employed to suppress the tip vibration of the manipulator. The effectiveness of the method is verified through computer simulations and consequently, the adequateness of the control performance and the feasibility of the system with a super-light link are shown.

SET POINT TRACKING CONTROL OF A REMOTELY OPERATED VEHICLE USING MODEL PREDICTIVE CONTROL

2021 ◽  
Vol 162 (A1) ◽  
Author(s):  
M P R Prasad
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
Vehicle Dynamics ◽  
Tracking Control ◽  
Sliding Mode ◽  
Pole Placement ◽  
Control Technique ◽  
Remotely Operated Vehicle ◽  
Point Tracking ◽  
Placement Technique

This paper considers kinematics and dynamics of Remotely Operated Underwater Vehicle (ROV) to control position, orientation and velocity of the vehicle. Cascade control technique has been applied in this paper. The pole placement technique is used in inner loop of kinematics to stabilize the vehicle motions. Model Predictive control is proposed and applied in outer loop of vehicle dynamics to maintain position and velocity trajectories of ROV. Simulation results carried out on ROV shows the good performance and stability are achieved by using MPC algorithm, whereas sliding mode control loses its stability when ocean currents are high. Implementation of proposed MPC algorithm and stabilization of vehicle motions is the main contribution in this paper.

Study on the Effect of Link Flexibility on Tip Position of a Single Link Robotic Arm

2021 ◽  
pp. 142-151
Author(s):  
E. Madhusudan Raju ◽  
L. Siva Rama Krishna ◽  
Y. Sharath Chandra Mouli ◽  
V. Nageswara Rao
Keyword(s):  
Robotic Arm ◽  
Single Link ◽  
Link Flexibility ◽  
Tip Position

scholarly journals Damage Detection and Vibration Control of a Delaminated Smart Composite Plate

2000 ◽  
Vol 9 (1) ◽  
pp. 096369350000900 ◽  
Author(s):  
Aditi Chattopadhyay ◽  
Changho Nam ◽  
Youdan Kim
Keyword(s):  
Composite Plate ◽  
Closed Loop ◽  
Order Theory ◽  
Pole Placement ◽  
Transverse Shear Deformation ◽  
Mean Square ◽  
Smart Composite ◽  
Closed Loop System ◽  
Higher Order Theory ◽  
Placement Technique

In this paper, the effects of delamination on the dynamic characteristics of a composite plate are investigated. The refined higher order theory is used to model the smart composite plate in the presence of delaminations. The theory accurately captures the transverse shear deformation through the thickness, which is important in anisotropic composites, particularly in the presence of discrete actuators and sensors and delaminations. Next, the detection of delamination is investigated using the Root Mean Square (RMS) values of the response of the composite plate subject to disturbances. An active control system is designed to minimise the effect of delamination. The pole placement technique is applied to design the closed loop system by utilising piezoelectric actuators. Numerical results show that the RMS information can be used to estimate the location of the delamination. The controller designed makes the delaminated plate behave like a healthy plate model. The controller also reduces the magnitudes of RMS responses due to disturbance.

Intelligent Adaptive Active Force Control of a Robotic Arm with Embedded Iterative Learning Algorithms

2012 ◽  
Author(s):  
Musa Mailah ◽  
Miaw Yong Ong
Keyword(s):  
Force Control ◽  
Learning Algorithms ◽  
Iterative Learning ◽  
Operating Conditions ◽  
Robotic Arm ◽  
Active Force ◽  
Inertia Matrix ◽  
Active Force Control ◽  
Controller Gain ◽  
On Line

Kawalan jitu dan lasak bagi satu sistem lengan robot atau pengolah adalah amat penting terutama sekali jika sistem mengalami pelbagai bentuk bebanan dan keadaan pengendalian. Kertas kerja ini memaparkan satu kaedah baru dan lasak untuk mengawal lengan robot menggunakan teknik pembelajaran secara berlelaran yang dimuatkan dalam strategi kawalan daya aktif. Sebanyak dua algoritma pembelajaran utama digunakan dalam kajian – yang pertama digunakan untuk menala gandaan pengawal secara automatik manakala yang satu lagi pula untuk menganggarkan matriks inersia pengolah. Kedua-dua parameter ini dihasilkan secara adaptif dan dalam talian ketika robot sedang menjalankan tugas menjejak trajektori dalam persekitaran tindakan daya gangguan. Dalam kajian ini, pengetahuan awal tentang kedua–dua nilai gandaan pengawal dan anggaran matriks inersia tidak wujud. Dengan demikian, suatu skema kawalan yang jitu dan lasak terhasil. Keberkesanan kaedah yang dicadangkan dapat ditentusahkan melalui hasil kajian yang diperoleh dan dibentangkan dalam kertas kerja ini. Kata kunci: Adaptif; kawalan daya aktif; pembelajaran berlelaran; matriks inersia; gandaan pengawal The robust and accurate control of a robotic arm or manipulator are of prime importance especially if the system is subjected to varying forms of loading and operating conditions. The paper highlights a novel and robust method to control a robotic arm using an iterative learning technique embedded in an active force control strategy. Two main iterative learning algorithms are utilized in the study – the first is used to automatically tune the controller gains while the second to estimate the inertia matrix of the manipulator. These parameters are adaptively computed on-line while the robot is executing a trajectory tracking task and subject to some forms of external disturbances. No priori knowledge of both the controller gains and the estimated inertia matrix are ever assumed in the study. In this way, an adaptive and robust control scheme is derived. The effectiveness of the method is verified and can be seen from the results of the work presented in this paper. Keywords: Adaptive; active force control; iterative learning; inertia matrix; controller gain

Projective Synchronization of a Modified Coupled Dynamos System

2012 ◽  
Vol 466-467 ◽  
pp. 1261-1265
Author(s):  
Chun Mei Wang ◽  
Ren Long Chang
Keyword(s):  
Chaotic System ◽  
Design Procedure ◽  
Scaling Factor ◽  
Drive System ◽  
Observer Design ◽  
Projective Synchronization ◽  
Pole Placement ◽  
Systematic Design ◽  
Unified Chaotic System ◽  
Placement Technique

Based on techniques from the state observer design and the pole placement technique, we present a systematic design procedure to synchronize a modified coupled dynamos system by a scaling factor ( projective synchronization ). Compared with the method proposed by Wen and Xu, this method eliminates the nonlinear item from the output of the drive system. Furthermore, the scaling factor can be adjusted arbitrarily in due course of control without degrading the controllability. Finally, feasibility of the technique is illustrated for the unified chaotic system.

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